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    Wyświetlanie 1-48 z 48
    Tytuł:
    First-principles study on the adsorption structure of water molecules on a pyrite (100) surface
    Autorzy:
    Liu, Yingchao
    Chen, Jianhua
    Li, Yuqiong
    Zhang, Junjie
    Kang, Duan
    Powiązania:
    https://bibliotekanauki.pl/articles/1447970.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    water molecules
    adsorption
    Opis:
    The hydration structure of water molecule adsorption at different coverages of a monolayer on a pyrite (100) surface were simulated using the density functional theory (DFT) method. The results demonstrate that the Fe-O interaction weakens and the adsorption energy per water molecule decreases with increasing water coverage, except at a monolayer coverage of 12/12 (i.e., full coverage). H-S and H-O hydrogen bonds were formed on the nearest surface layer. When large amounts of water molecules adsorb onto the surface, the adsorbed water molecules can be divided into three layers: the layer nearest to the surface, the second nearest to the surface, and the layer farthest from the surface. The thickness of the former two layers is approximately 5.5 Å. The three layers have water densities of 1.12 g/cm3, 1.08 g/cm3, and 0.95 g/cm3, respectively, suggesting that there is a strong interaction between the pyrite surface and water molecules and the influence of surface structure on water adsorption reaches a distance of more than 10 Å. Dynamics simulations suggest that the water molecules close to the mineral surfaces are in an orderly arrangement while those far from the surface are disordered.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 2; 121-130
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Cell adhesion molecules and their possible role in the pathology of the peripheral nerves – a review of the literature
    Autorzy:
    Niezgoda, Adam
    Powiązania:
    https://bibliotekanauki.pl/articles/552657.pdf
    Data publikacji:
    2015
    Wydawca:
    Stowarzyszenie Przyjaciół Medycyny Rodzinnej i Lekarzy Rodzinnych
    Tematy:
    cell adhesion molecules
    demyelination
    polyneuropathies.
    Źródło:
    Family Medicine & Primary Care Review; 2015, 4; 323-326
    1734-3402
    Pojawia się w:
    Family Medicine & Primary Care Review
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analitical criteria of homogeneous and heterogeneous detonation of liquid energetic materials
    Autorzy:
    Kaim, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/92588.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    mechanism detonation initiation
    hot spots
    nanopores
    emission atoms and molecules
    shock dissociation molecules
    Opis:
    Statistical theory of liquids is used to investigate mechanism of detonation initiation on fronts of flat shock waves in homogeneous liquid and in liquid containing spherical nanopores. We calculated thermodynamic parameters of liquid methane sufficient for shock dissociation of molecules at a front of a shock wave. Calculations of the average single-particle force potential show that at high pressures and temperatures atoms and molecules get emitted from the surface into a nanopore with hyper-thermal speeds. Implosion of spherically symmetric stream of molecules may lead to destruction of the molecules at impact. We explained existence of top and bottom bounds for pressure during detonation initiation in heterogeneous energetic materials. In terms of pair interaction potentials and correlation functions there are formulated criteria for boundary values of thermodynamic parameters which are required for initiation of homogeneous and heterogeneous detonations based on the "hot spot"’ mechanism.
    Źródło:
    Materiały Wysokoenergetyczne; 2013, T. 5; 5-13
    2083-0165
    Pojawia się w:
    Materiały Wysokoenergetyczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dendrimers: properties and applications.
    Autorzy:
    Klajnert, Barbara
    Bryszewska, Maria
    Powiązania:
    https://bibliotekanauki.pl/articles/1044187.pdf
    Data publikacji:
    2001
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    cascade molecules
    dendrimers
    PAMAM dendrimers
    Opis:
    Dendrimers are a new class of polymeric materials. They are highly branched, monodisperse macromolecules. The structure of these materials has a great impact on their physical and chemical properties. As a result of their unique behaviour dendrimers are suitable for a wide range of biomedical and industrial applications. The paper gives a concise review of dendrimers' physico-chemical properties and their possible use in various areas of research, technology and treatment.
    Źródło:
    Acta Biochimica Polonica; 2001, 48, 1; 199-208
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Selected small molecules as inducers of pluripotency
    Autorzy:
    Baranek, Małgorzata
    Markiewicz, Wojciech
    Barciszewski, Jan
    Powiązania:
    https://bibliotekanauki.pl/articles/1038727.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    reprogramming
    pluripotency
    small molecules
    iPSCs
    Opis:
    The general idea of regenerative medicine is to fix or replace tissues or organs with live and patient-specific implants. Pluripotent stem cells are capable of indefinite self-renewal and differentiation into all cell types of the body. An easily accessible source of induced pluripotent stem cells (iPSCs) may allow obtaining and culturing tissues in vitro. Many approaches in the methods leading to obtain iPSCs have been tested in order to limit immunogenicity and tumorigenesis, and to increase efficiency. One of the approaches causing pluripotency is usage of small molecule compounds. It would be of great importance to assess their specific properties and reveal their new capacity to induce pluripotent stem cells and to improve reprogramming efficiency. Identification of the epigenetic changes during cellular reprogramming will extend our understanding of stem cell biology and many therapeutic applications. In this paper we discuss mainly the nucleotide derivatives, already proven or for now only putative inducers of the cells' pluripotency, that modulate the epigenetic status of the cell.
    Źródło:
    Acta Biochimica Polonica; 2016, 63, 4; 709-716
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Calcium phosphate nanoparticles for delivering synthetic drug molecules across the cell membrane
    Autorzy:
    Rotan, O.
    Sokolova, V.
    Schrader, T.
    Epple, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/285174.pdf
    Data publikacji:
    2014
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
    Tematy:
    nanoparticles
    cell membranes
    drug molecules
    Źródło:
    Engineering of Biomaterials; 2014, 17, no. 128-129; 77-78
    1429-7248
    Pojawia się w:
    Engineering of Biomaterials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Na-montmorillonite modified with ammonium salts and azobenzene as a photoactive nanomaterial
    Autorzy:
    Koteja, A.
    Matusik, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/184535.pdf
    Data publikacji:
    2016
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    inorganic solid structures
    organic molecules
    minerals
    Opis:
    Modification of inorganic solid structures (e.g. minerals) with organic molecules is a constantly developed topic in material sciences. The organic functionalization leads to the production of new materials with integrated properties of both the organic and inorganic component. In the presented study we have modified a Na-montmorillonite with alkylammonium surfactants and subsequently azobenzene, in order to obtain a nanomaterial that shows response to UV radiation. Azobenzene is a photoswitchable organic molecule capable to change its conformation upon UV radiation from the trans- to cis-azobenzene isomer. This reaction is coupled with a change of the molecules shape and dimensions (Klajn 2010). The montmorillonite is a layered aluminosilicate that serves as an excellent host structure for organic guest species. Due to the net negative layer charge it shows the ability to swell and to exchange the originally present interlayer cations. These properties allow the intercalation of bulk organic molecules and to control their arrangement. Much attention has been paid to the possibility of transferring the photoswitching ability of organic molecule into the motion of the whole organo-mineral structure (Heinz et al. 2008). Such nanoswitch is particularly appealing as it is controlled with radiation – remotely and at a precise location. The efficiency of a synthesized nanoswitch depends on an accurate selection of the host and guest component. The target of this study to test a series of organic surfactants and to establish a modification pathway that leads to obtaining a material most promising in the view of its photoresponsive behavior. The montmorillonite modification was performed in a two-step procedure, as the direct intercalation of a nonionic azobenzene is not possible. First, the Na-montmorillonite (denoted SWy) was ion-exchanged with trimethylalkylammonium cations abbreviated C n and benzyldimethylalkylammonium cations – BC n , where n refers to the number of carbon atoms in the alkyl chain and is equal to 12, 14 or 16. In the second step the organo-montmorillonites were reacted with azobenzene (AzBz) for 24 h at 120°C in a hermetically closed teflon vessel. The yellowish products were characterized with the X-Ray diffraction (XRD), the infrared spectroscopy (FTIR) and CHN elemental analysis. In all cases the intercalation of the ammonium cation caused an increase of the montmorillonites basal spacing ( d 001 ). The d 001 values were equal to 16.4 Å, 18.2 Å and 20.5 Å for SWy-C 12 , SWy-C 14 and SWy-C 16 , respectively. The samples modified with the BC n cations showed ~1.5 Å larger basal spacing, due to the presence of the benzyl group in the intercalated molecule. A linear relationship was observed between the d 001 value and the alkyl chain length of the introduced salts. This suggests that the organic cations formed paraffin-type aggregates in the interlayer (Ogawa et al. 1999) where the molecules are inclined to the layer surface. The FTIR spectra of modified SWy sample showed intense bands corresponding to CH 2 vibration modes. Along with the increasing alkyl chain length the CH 2 stretching bands shifted towards lower energies. This is an effect of growing packing density of alkylammonium molecules in the interlayer (He et al. 2004) and it is coupled with straightening of the alkyl chains due to transformation of disordered gauche conformer to the ordered all-trans conformer (Vaia et al. 1994). It can be concluded that the longer alkyl chains (C 16 and BC 16 ) form more ordered, solid-like aggregates in the interlayer space. The molar content of organic molecules was calculated basing on the CHN elemental analysis. The amount of intercalated alkylammonium cations was nearly equal to the cation exchange capacity (CEC) of montmorillonite – 88.9 meq/100 g. The reaction with azobenzene was most effective for montmorillonite modified with the alkylammonium cations having the longest chains as confirmed by the XRD patterns. The d 001 values of SWy-C 16 and SWy-BC 16 samples after reaction with AzBz increased to 36.9 Å and 35.9 Å, respecively. Well resolved and intense (001) peaks as well as the presence of the 2 nd and 3 rd order reflections indicated a highly ordered structure of these intercalates. On the contrary, diffraction peaks were less resolved and broadened for samples prepared with the shorter C 12 , C 14 , BC 12 and BC 14 molecules after reaction with AzBz. Based on these results, it is assumed that the long chain alkylammonium ions are more effective surfactants for the further intercalation of azobenzene into the montmorillonites interlayer space. The obtained highly ordered structures are promising materials for application as photo-actuated nanoswitches.
    Źródło:
    Geology, Geophysics and Environment; 2016, 42, 1; 87-88
    2299-8004
    2353-0790
    Pojawia się w:
    Geology, Geophysics and Environment
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Resonance contributions to low-energy electron collisions with molecular hydrogen
    Autorzy:
    Horácek, J.
    Cížek, M.
    Houfek, K.
    Kolorenc, P.
    Pichl, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/148461.pdf
    Data publikacji:
    2003
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    electron scattering
    molecules
    attachment
    vibrational excitation
    Opis:
    Calculations of electron dissociative attachment and vibrational excitation of molecular hydrogen by low-energy electrons based on an improved nonlocal resonance model are reported. The role of the rotational excitation of the target molecules is discussed.
    Źródło:
    Nukleonika; 2003, 48, 2; 109-112
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evaluation of neutrophil phagocytic, complement functions, and cytokines expression among diabetic patients in Abuja, Nigeria
    Autorzy:
    Babandina, Musa Muhammad
    Mainasara, Abdullahi Suleiman
    Bakare, Mustapha
    Emeribe, Anthony Uchenna
    Shuwa, Halima Ali
    Haruna, Shamsuddeen
    Muhammad, Aminu Said
    Abdullahi, Idris Nasir
    Powiązania:
    https://bibliotekanauki.pl/articles/454973.pdf
    Data publikacji:
    2019
    Wydawca:
    Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
    Tematy:
    diabetes mellitus
    effector molecules
    pro-inflammatory markers
    Opis:
    Introduction. Inflammatory response in Diabetes Mellitus (DM) begins with chronic sub-clinical inflammations as a result of insulin resistance and activation of both innate and adaptive immune system as the disease progresses to complicated diabetes. Hence, the present study investigated the neutrophil phagocytic, complement function (CH50), and some cytokine profiles among diabetic and non-diabetic patients attending the National Hospital in Abuja, Nigeria. Aim. To evaluate the neutrophil phagocytic, complement function (CH50), and some cytokine profiles among post-operative septic diabetic and post-operative septic non-diabetic patients at the National Hospital in Abuja, Nigeria. Material and methods. Subjects were recruited by convenient sampling technique through interviewer-administered questionnaires. Subsequently, blood samples were collected. Fasting blood sugar (FBS) (mmol/L) was determined using glucose oxidase method. Neutrophil function test (Fmol/phag) was assayed using nitroblue tetrazolium reduction test (NBT). Hemolytic complement function (CH 50) test was conducted using serum harvested from sheep sensitized with human group (ORh D +ve) red blood cells. While serum Interleukin-4, -6, -10 and TNF- α were determined using Enzyme Linked Immunosorbent Assay (ELISA). Results. Mean ± Standard deviation (SD) of FBS concentration of 10.5 ± 1.3 (mmol/|L) among diabetic and 4.7 ± 0.9 (mmol/L) among non-diabetics was recorded. There is a decrease in neutrophil phagocytic function with a mean ± SD of 5.4 ± 2.1 (Fmol/ phag) in diabetics compared to 9.2 ± 2.1 (Fmol/phag) in non-diabetics. Similarly, complement (CH 50) function and C-reactive protein were significantly lower in diabetics when compared to non-diabetics (p<0.001). There was a significant difference in IL-6 concentration between diabetics and non-diabetics groups, but no significant difference was observed in TNF-α, IL-4 and IL-10 concentrations between study groups (p>0.05). TNF-α and IL-6 was significantly higher in diabetics with cardiovascular disorders compared to non-diabetics subjects with cardiovascular disorders (p<0.001). Conclusion. Findings from this study revealed the association of complement, neutrophil phagocytic function, CRP and IL-6 among septic diabetic patients,. In addition TNF-α and IL-6 expression was higher in DM patients with cardiovascular disorders.
    Źródło:
    European Journal of Clinical and Experimental Medicine; 2019, 3; 229-235
    2544-2406
    2544-1361
    Pojawia się w:
    European Journal of Clinical and Experimental Medicine
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Free electrons: fundamental interactions, applications and data needs
    Autorzy:
    Christophorou, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/148509.pdf
    Data publikacji:
    2003
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    applications
    data
    interactions
    low-energy electrons
    molecules
    Opis:
    In spite of the important recent advances in the field of low-energy electron interactions with atoms and molecules, there still exist fundamental needs and challenges, some of which are generic in their basic and applied significance. These include measurements of cross sections for a number of fundamental low-energy electron–ground-state molecule interaction processes such as vibrational excitation (direct and indirect) and dissociation into neutral fragments, studies of low-energy electron–excited molecule interactions, investigations of low-energy electron interactions with radicals and transient species, and measurements of electron energy losses in electron–molecule collision processes. They also include studies for linking of knowledge on isolated electron–molecule interactions to that in the condensed phases of matter, and the systematic and quantitative exploration of the interactions of low-energy electrons with molecular and macromolecular biological structures.
    Źródło:
    Nukleonika; 2003, 48, 2; 67-74
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Some results of an analysis of polyhydric alcohols effect on detoxication processes
    Autorzy:
    Konovchuk, V.
    Andrushchak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2052425.pdf
    Data publikacji:
    2015
    Wydawca:
    Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
    Tematy:
    severe sepsis
    rheosorbilact
    endotoxicosis
    medium weight molecules
    Opis:
    Rheosorbilact action on antitoxic function of the kidneys has been analysed using the values of medium weight molecules in patients with severe sepsis. The study design includes the criteria of inclusion, exclusion and cessation. Patients with pyoceptic complications (mainly surgical abdominal sepsis) with signs of severe endotoxicosis, dopaminergic activity (5-10 mcg/kg min), biochemical criteria of SS (lactate >4 mmole/l, С-reactive protein >2 standard departures from the norm) and other signs of severe sepsis with generalized disorders in homeostasis (assessing the multiple organ damage course by H.Celye-I.A. Yeriuhin scale- 20-27 points, MODS scale – 6-10 points) corresponded to the inclusion criterion. All patients were provided with appropriate debridement and intensive traditional therapy. For control studies we involved patients with systemic inflammatory response syndrome who had 2-3 signs of SIRS in stage A. It was found that rheosorbilact activates the transportation of medium weight molecules out of the extracellular space and increases their excretion by the renal nephrons in patients with severe sepsis. It was established that in severe sepsis rheosorbilact provides a high level of excretion of medium weight molecules by suppressing processes of reabsorption in the proximal nephron portions caused by peptidase dependent metabolism.
    Źródło:
    Health Problems of Civilization; 2015, 09, 2; 35-38
    2353-6942
    2354-0265
    Pojawia się w:
    Health Problems of Civilization
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The dynamics of biochemical markers of enzymoemia and middle-weight molecules in the early post-traumatic period of brain injury
    Autorzy:
    Ziablitsev, S. V.
    Elskyy, V. N.
    Pischulina, S. V.
    Strelchenko, U. I.
    Antonov, E. V.
    Sudilovskaya, U. L.
    Khudoley, S. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032378.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Kazimierza Wielkiego w Bydgoszczy
    Tematy:
    brain injury
    biochemical markers
    enzymoemia
    middle-weight molecules
    Opis:
    In the experimental model of brain injury (BI) markers of enzymoemia (aminotransferases ALT and AST, alkaline and acid phosphatase (AlP and AcP), cathepsin D (CD)) and middle-weight molecules (MWM) were estimated. 3 hours after trauma there were increase of all enzymes that evidences about damage of cytoplasmic (ALT, AST, AlF) and lysosomal membranes (AcP, CD). During period of observation different dynamics of enzymatic changes occurred: plateau phase for ALT and CD and progressive increase of concentration with the maximum on the 5th day of the experiment for AlP and AcP. Increase of the level of MWM displayed the development of endogenous intoxication in the post-traumatic period. Relation between particular components of MWM was studied. It was shown that primary accumulation of nucleotide fraction and aromatic peptides is adverse factor of the course of post-traumatic period, development of endotoxicosis, and multiorgan failure.
    Źródło:
    Journal of Health Sciences; 2014, 4, 1; 297-302
    1429-9623
    Pojawia się w:
    Journal of Health Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Genetic Variations of the CTNNA1 And The CTNNB1 Genes in Sporadic Colorectal Cancer in Polish Population
    Autorzy:
    Sygut, Andrzej
    Przybyłowska, Karolina
    Ferenc, Tomasz
    Dziki, Łukasz
    Spychalski, Michał
    Mik, Michał
    Dziki, Adam
    Powiązania:
    https://bibliotekanauki.pl/articles/1396892.pdf
    Data publikacji:
    2012-12-01
    Wydawca:
    Index Copernicus International
    Tematy:
    sporadic colorectal cancer
    muations
    catenin gene
    adhesion molecules
    Opis:
    Experimental as well as clinical observations have demonstrated that the E-cadherin/catenin complex is a powerful inhibitor of invasion. Abrogation of this pathway is implicated in the carcinogenesis of several malignancies, especially colorectal cancer. The aim of the study was to determine the CTNNA1 and the CTNNB1 mutations and its relationship to clinical and pathological features of sporadic colorectal cancer (CRC) in Polish patients. Material and methods. Paired tumor and normal tissue samples from 110 sporadic CRC patients undergoing resective surgery were prospectively studied for the alpha catenin (CTNNA1) gene and beta catenin (CTNNB1)gene mutations by PCR/single strand conformation polymorphism (SSCP). Results. The CTNNA1 gene alteration in exon 7 were detected in 4 samples and in exon 3 of CTNNB1 gene were found in 3 samples. There was a trend at the limit of statistical significance associating younger age at diagnosis (<50) with CTNNA1 and the CTNNB1 mutations. The mutation of CTNNB1 seemed to occur more frequently in the proximal colon than distal. The CRC patients with CTNNA1 mutation had a significantly increased lymph node metastasis. On the other hand, there was no correlation between mutations and the other clinical variables (e.g. sex, grade and depth of invasion). Conclusion. Although we found a low frequency of mutations in the CTNNA1 and the CTNNB1 genes, but the analysis the relationship with clinical and pathological features of CRC patients may indicated an association of these mutations with the risk and progression of CRC.
    Źródło:
    Polish Journal of Surgery; 2012, 84, 11; 560-564
    0032-373X
    2299-2847
    Pojawia się w:
    Polish Journal of Surgery
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Cloning and purification of functionally active Fas ligand interfering protein (FIP) expressed in Escherichia coli
    Autorzy:
    Wisniewski, Pawel
    Master, Adam
    Kaminska, Bozena
    Powiązania:
    https://bibliotekanauki.pl/articles/1040813.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Fas ligand
    interfering molecules
    recombinant protein purification
    Fas
    apoptosis
    Opis:
    This report presents purification and characterization of the extracellular domain of rat Fas protein, called FIP (FasL interfering protein), expressed as inclusion bodies in Escherichia coli. FIP was extracted from the inclusion bodies, solubilized with 8 M urea, purified by a single-step immobilized metal ion (Ni2+) affinity chromatography and refolded. SDS/PAGE and mass spectrometry analysis of the purified protein verified its purity. Fluorescence spectrum analysis showed that the refolding procedure caused structural changes which presumably might have led to oligomerization. The purified FIP has biological activities: it binds specifically soluble Fas ligand and protects human Jurkat lymphocytes against FasL-dependent apoptosis. This efficient procedure of FIP expression in E. coli and renaturation may be useful for production of therapeutically important proteins.
    Źródło:
    Acta Biochimica Polonica; 2008, 55, 1; 51-56
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Regulatory function of parasites in autoimmune disease – outcome from experimental model infection
    Autorzy:
    Krawczak, Katarzyna
    Donskow-Łysoniewska, Katarzyna
    Doligalska, Maria
    Powiązania:
    https://bibliotekanauki.pl/articles/972241.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Parazytologiczne
    Tematy:
    immunoparasitology
    animal model
    helminth
    autoimmune disorders
    parasite driven molecules
    Opis:
    It is estimated that more than half of the nowadays known species are pathogenic parasites. Among macroparasites gastrointestinal nematodes are one of most common and having significant impact on life and health. Those organisms reveal strong, specific immune response in host, involving primary mechanisms associated with regulatory and Th2 cells. Referring to immunomodulatory abilities of helminths, parasite infections started to be considered as a possible therapy for many autoimmune diseases. Clinical trials on 2nd and 3rd stage are conducted in spite that treatment has not been recognized as safe for common use. Despite that the safety of treatment with parasites is still controversial and widely discussed. Our knowledge about mechanisms used by helminth to moderate immune response is still inadequate to predict possible effect of long lasting parasite infection on individual patients.
    Źródło:
    Annals of Parasitology; 2017, 63, 1; 7-14
    0043-5163
    Pojawia się w:
    Annals of Parasitology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analytical solutions of Schrödinger equation with new solvable potential family V(r)=A/r^2-B/r+Cr^(δ+1) via Nikiforov-Uvarov (NU) method
    Autorzy:
    Antia, Akaninyene Daniel
    Akpan, Ita Okon
    Ikot, Akpan Ndem
    Maghsoodi, Elham
    Zarrinkamar, Saber
    Hassanabadi, Hassan
    Powiązania:
    https://bibliotekanauki.pl/articles/763317.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
    Tematy:
    Schrödinger equation
    Energy eigenvalue
    Eigenfunction
    Diatomic molecules
    Hellmann-Feynmann theorem
    Opis:
    In this paper, we have presented the exact solutions of the Schrödinger equation with the family of potentials V(r)=A/r^2-B/r+Cr^(δ+1). We have obtained the energy eigenvalues and the corresponding wave functions expressed in terms of the associated Laguerre polynomials for  using the Nikiforov-Uvarov (NU) method. The energy levels for each case is computed for diatomic molecules H2, CO, NO and N2  for various values of and . We have also computed the expectation values of, and the Virial theorem using the Hellmann-Feynmann theorem (HFT).
    Źródło:
    Annales Universitatis Mariae Curie-Skłodowska, sectio AAA – Physica; 2015, 70
    0137-6861
    Pojawia się w:
    Annales Universitatis Mariae Curie-Skłodowska, sectio AAA – Physica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Markers of endothelial dysfunction in young non-overweight women - effect of serum lipids, body measures and nutrition
    Autorzy:
    Witkowska, AM.
    Zujko, ME.
    Powiązania:
    https://bibliotekanauki.pl/articles/1916451.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Medyczny w Białymstoku
    Tematy:
    endothelial dysfunction
    cellular adhesion molecules
    lipids
    nutrition
    body measures,
    women
    Opis:
    Purpose: Since endothelial dysfunction can develop early in the adulthood, the purpose of the study was to determine how serum lipids, body measures and dietary habits affect serum markers of vascular activation in young women. Materials and methods: Twenty five healthy women, aged 19-22 years, were enrolled in the study. Serum lipids profile (total cholesterol, HDL-cholesterol, triglycerides) was assayed with laboratory test kits. Concentrations of sICAM-1, sVCAM-1 and E-selectin were determined with the ELISA technique. Anthropometric measurements were taken including skinfold thickness and waist circumference. Food consumption data were collected using 3 repeats of 24-hour dietary recalls. Dietary habits of the women were assessed with a 9-point alternate Mediterranean Diet score (a-MED). Results: Sixty eight percent of the subjects had their HDL-cholesterol levels below the desirable concentration, 20% had LDL-cholesterol elevated, and 32% demonstrated increased total triacylglycerols (TAG). The levels of serum TAG >199 mg/dL were associated with a significant rise in the VCAM-1 concentration. Dietary wholegrain products seem to reduce the serum E-selectin. Conclusions: The results suggest that young women of normal body mass, but demonstrating increased levels of serum TAG, may be at risk of developing endothelial dysfunction. An implementation of the wholegrain products consumption into their dietary practices would possibly be of health benefit.
    Źródło:
    Progress in Health Sciences; 2014, 4, 1; 24-30
    2083-1617
    Pojawia się w:
    Progress in Health Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The role of cell adhesion molecule in cancer progression and its application in cancer therapy.
    Autorzy:
    Okegawa, Takatsugu
    Pong, Rey-Chen
    Li, Yingming
    Hsieh, Jer-Tsong
    Powiązania:
    https://bibliotekanauki.pl/articles/1043281.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    cancer gene therapy
    gene
    cell adhesion molecules
    tumor progression
    tumor suppressor
    Opis:
    Multiple and diverse cell adhesion molecules take part in intercellular and cell-extracellular matrix interactions of cancer. Cancer progression is a multi-step process in which some adhesion molecules play a pivotal role in the development of recurrent, invasive, and distant metastasis. A growing body of evidence indicates that alterations in the adhesion properties of neoplastic cells play a pivotal role in the development and progression of cancer. Loss of intercellular adhesion and the desquamation of cells from the underlying lamina propria allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasion phenotype, and finally, invade and metastasize. In addition to participating in tumor invasiveness and metastasis, adhesion molecules regulate or significantly contribute to a variety of functions including signal transduction, cell growth, differentiation, site-specific gene expression, morphogenesis, immunologic function, cell motility, wound healing, and inflammation. Cell adhesion molecule (CAM), a diverse system of transmembrane glycoproteins has been identified that mediates the cell-cell and cell-extracellular matrix adhesion and also serves as the receptor for different kinds of virus. We summarize recent progress regarding the role of CAM, particularly, immunoglobulin-CAMs and cadherins in the progression of cancer and discuss the potential application of CAMs in the development of cancer therapy mainly on urogenital cancer.
    Źródło:
    Acta Biochimica Polonica; 2004, 51, 2; 445-457
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Quorum Sensing Materials as New Ligand for Palladium Catalyzed Migita-Kosugi-Stille Polycondensation
    Autorzy:
    Wang, A.
    Toyofuku, M.
    Nomura, N.
    Goto, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/412569.pdf
    Data publikacji:
    2014
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    signal molecules
    quorum sensing
    Migita-Kosugi-Stille coupling
    π-conjugated polymers
    Opis:
    Signal molecules for quorum sensing are employed for ligands to palladium. The complex can be used as a catalyst. Migita-Kosugi-Stille coupling reactions are driven by using a series of N-(3- oxo-acyl)-L-homoserine lactones as ligands coordinating with Pd. Catalysis of [Pd-(signal molecules for quorum sensing), or Pd/QS] allows production of conjugated polymers with light-emitting functions.
    Źródło:
    International Letters of Chemistry, Physics and Astronomy; 2014, 13, 1; 62-70
    2299-3843
    Pojawia się w:
    International Letters of Chemistry, Physics and Astronomy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Detonation Performance of Oxygen-rich Trinitromethylsubstituted Pyrazoles: an in-silico Investigation
    Autorzy:
    Naithani, N.
    George, B. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358132.pdf
    Data publikacji:
    2018
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    nitropyrazole
    aminonitropyrazoles
    detonation velocity
    detonation pressure
    density functional theory
    high energy molecules
    Opis:
    A new class of high energy molecules was designed and their detonation properties were evaluated using thermo-chemical parameters obtained from quantum chemical calculations at B3LYP/6-31G(d,p) level. The designed molecules exhibited high density, positive oxygen balance and excellent detonation properties. The impact sensitivity of these molecules, in terms of H50 values, was also evaluated from structural correlations. Among these, 3,4,5-tris(trinitromethyl)1H-pyrazol-1-amine (N13) showed the highest detonation pressure (40.67 GPa) and highest detonation velocity (9.17 km/s), though it exhibited high impact sensitive (H50 = 15 cm). Interestingly, 4,5-dinitro-3-(trinitromethyl)-1H-pyrazol-1-amine (N01) (detonation pressure 39.69 GPa; detonation velocity 9.23 km/s) was found to be an ideal high energy molecule with a near zero oxygen balance. The H50 value of N01 was predicted to be 64 cm, which is higher in magnitude, indicating a lower sensitivity than that of the conventionally used RDX (H50 = 26 cm).
    Źródło:
    Central European Journal of Energetic Materials; 2018, 15, 4; 537-533
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Crystal Structure Prediction and Charge Density Distribution of Highly Energetic Dimethylnitraminotetrazole: a First Step for the Design of High Energy Density Materials
    Autorzy:
    Arputharaj, D. S.
    Srinivasan, P.
    Asthana, S. N.
    Pawar, R. B.
    Kumaradhas, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/358205.pdf
    Data publikacji:
    2012
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    energetic materials
    crystal structure prediction
    charge density analysis
    atoms in molecules
    electrostatic potential
    Opis:
    The crystal structure of dimethylnitraminotetrazole has been predicted, based on systematically searching for densely packed structures within common organic crystal coordination types, followed by lattice energy minimization. The predicted crystal structures almost match the reported crystal structure determined by X-ray diffraction analysis. To understand the effect of the initial molecular geometry on the crystal packing, the crystal structure simulation was carried out for molecules taken from different environments, such as the X-ray structure (crystal field) and also from ab initiocalculations (gas phase). The predicted crystal structures from both environments are very similar to the reported X-ray structure with a maximum deviation of 4.5%. The crystal density predicted from both methods is close to that reported. The bond topological, energetic and electrostatic properties of the isolated molecule from the predicted crystal structure have been determined using Bader's theory of atoms in molecules. The bond topological characterization reveals that the C-N bond is the weakest bond in the molecule. A large electronegative potential is found in the vicinity of the NO2group and the nitrogen-rich region of the tetrazole ring; these are probably the reactive sites of this molecule.
    Źródło:
    Central European Journal of Energetic Materials; 2012, 9, 3; 201-217
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Distribution of gas molecules by their temperatures
    Autorzy:
    Golovkin, Boris Georgievich
    Powiązania:
    https://bibliotekanauki.pl/articles/1030475.pdf
    Data publikacji:
    2020
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    Clapeyron equation
    Maxwell distribution
    distribution of molecules by temperatures
    gas density
    gas pressure
    Opis:
    A formula is derived for the distribution of gas molecules over their temperatures depending on the total temperature of the gas. Formulas are proposed for the distribution of velocities and kinetic energies of gas molecules depending on the pressure and density of the gas. It is shown that these formulas are equivalent to the formulas of the corresponding Maxwell distributions, which depend only on temperature. A formula is derived for the distribution of the mean free paths of gas molecules depending only on the gas density. An example of calculating the distribution of gas molecules by their temperatures is given.
    Źródło:
    World Scientific News; 2020, 144; 89-102
    2392-2192
    Pojawia się w:
    World Scientific News
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Distribution of the lengths of tree paths of gas molecules
    Autorzy:
    Golovkin, B. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1075713.pdf
    Data publikacji:
    2019
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    distribution of molecules
    gas
    mean free path
    pressure
    radius of the molecule
    temperature
    Opis:
    It is shown that the formula available in the literature for the distribution of the mean free paths of gas molecules, independent of pressure and temperature, produces obviously incorrect results. Accordingly, a conclusion is given for another formula for a given distribution, which depends on the size of the gas molecules, as well as temperature and pressure. In accordance with this formula, the distribution curve for oxygen at 1000 K and pressures 1 and 0.001 atm has been calculated.
    Źródło:
    World Scientific News; 2019, 119; 243-247
    2392-2192
    Pojawia się w:
    World Scientific News
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bending Behaviour of LLDPE Monofilaments Depending on Cold Drawing and Composition of the LLDPEs
    Właściwości charakteryzujące zginanie monofilamentów LLDPE w zależności od stopnia zimnego rozciągu i składu polimeru
    Autorzy:
    Kolgjini, B.
    Schoukens, G.
    Shehi, E.
    Kiekens, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/232591.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
    Tematy:
    polyethylene
    draw ratio
    resilience
    monofilaments
    tie molecules
    polietylen
    współczynnik rozciągania
    sprężystość
    włókna
    cząsteczki krawata
    Opis:
    The behaviour of the pile layer of artificial turf is an important element for the performance of artificial turf. As a top layer, it is constantly under deformation, with the most possible being bending . The bending behaviour of monofilaments of linear low density polyethylene (LLDPE) is strongly influenced by the processing parameters, the type of polymer, and geometrical factors, which in combination with each other seem to have a strong influence on the behaviour of the final product. From the results obtained, the use of octene instead of hexene as a monomer yields better results for resilience due to a higher concentration of intrafibrillar tie molecules for the same degree of DSC crystallinity of the LLDPEs. The increase in the final cross section of monofilaments based on the same LLPDPEs resulted in a decrease in the intrafibrillar tie molecules due to a slower cooling after melt extrusion.
    Badania dotyczyły obróbki wykańczalniczej jedwabiu naturalnego. Mikrostruktura jedwabiu była badana za pomocą skaningowej mikroroskopii elektronowej, a właściwości mechaniczne testowane były klasyczną zrywarką firmy Instron, podczas gdy strukturę krystaliczną analizowano za pomocą spektroskopii w podczerwieni (FTIR) oraz rozproszenia promieniowania rentgenowskiego. Wyniki pozwoliły wytypować najlepszą w danych warunkach metodę obróbki.
    Źródło:
    Fibres & Textiles in Eastern Europe; 2013, 4 (100); 23-30
    1230-3666
    2300-7354
    Pojawia się w:
    Fibres & Textiles in Eastern Europe
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Physical meaning temperature of gas and separate molecule
    Autorzy:
    Golovkin, B. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1157177.pdf
    Data publikacji:
    2018
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    distribution of molecules by temperature
    gas cell
    mean free path
    temperature of a molecule
    Opis:
    Starting from the equation of state of the Clapeyron gas, it is shown that the temperature of a monatomic molecule of radius and mass moving with velocity is equal to , where: l are the length of a molecule without collisions, the Boltzmann constant, the kinetic energy of the molecule. The physical meaning of the temperature of a molecule should be understood as the kinetic energy that it has in the path without collisions l. The dimension of temperature coincides with the size of energy, but quantitatively the energy differs by the presence of a dimensionless factor , characterizing the motion of a molecule in fractions of its radius. Based on the temperatures of the individual molecules and their relative amounts contained in the gas, a formula is proposed for the overall gas temperature, for any, even nonequilibrium, distribution. The physical meaning of the gas temperature is determined by the product of the mean kinetic energy, the average mean free path of its molecules, and their size.
    Źródło:
    World Scientific News; 2018, 94, 2; 313-320
    2392-2192
    Pojawia się w:
    World Scientific News
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Molecular basis of quorum sensing signal-response systems in bacteria
    Autorzy:
    Ziemichód, Alicja
    Skotarczak, Bogumiła
    Powiązania:
    https://bibliotekanauki.pl/articles/1386055.pdf
    Data publikacji:
    2017
    Wydawca:
    Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
    Tematy:
    autoinducers 2 and 3
    QS phenomenon
    quinolone signal molecules
    signal molecules of Grampositive and Gram-negative bacteria
    autoinduktory 2 i 3
    chinolonowe cząsteczki sygnałowe
    cząsteczki sygnałowe bakterii Gramdodatnich i Gram-ujemnych
    zjawisko QS
    Opis:
    Bacteria use quorum sensing (QS) to conduct gene expression programmes connected with collective behaviors. QS indicates on the capacity of bacteria to monitor their population density and regulate gene expression. QS activates from tens to hundreds of genes that underlie different biological processes. The QS-regulated processes organize horizontal gene transfer, the formation of biofilms, multicellular behaviors, microbe–host and microbe–microbe relations. The QS signaling requires the production, release, detection, exchange and perception of bacterial compounds, known as autoinducers or QS signals. Recently, new autoinducers have been discovered in bacteria and it has been shown how these molecules are recognized by the respective receptors. Autoinducers belong to three major classes: acyl-homoserine lactones (AHLs) used by Gram-negative bacteria, specific oligopeptides used by Gram-positive bacteria and universal autoinducers. The aim of this paper is to provide an overview of molecular basis of the QS phenomenon, characterization of intra- and interspecies QS signaling molecules and biological processes regulated by these molecules.
    Bakterie używają quorum sensing (QS) do przeprowadzania programów ekspresji genów związanych z zachowaniami grupowymi. QS oznacza zdolność bakterii do monitorowania gęstości swojej populacji i regulacji ekspresji genów. QS aktywuje od dziesiątek do setek genów, które są związane z różnymi procesami biologicznymi. Procesy regulowane przez QS są związane z horyzontalnym przepływem genów, tworzeniem biofilmów, zachowań wielokomórkowych, oraz relacji bakteria–żywiciel i bakteria–bakteria. Sygnalizacja QS wymaga wytwarzania, uwalniania, wykrywania, wymiany i percepcji komponentów nazywanych autoinduktorami lub sygnałami QS. Ostatnio u bakterii zostały odkryte nowe autoinduktory oraz wykazano jak te cząsteczki są rozpoznawane przez odpowiednie receptory. Autoinduktory należą do trzech głównych klas: do acylowanych laktonów homoseryny (AHLs) używanych przez bakterie Gram-ujemne, specyficznych oligopeptydów używanych przez bakterie Gram dodatnie i do autoinduktorów uniwersalnych. Celem artykułu jest przegląd bazy molekularnej zjawiska QS, w tym wewnątrz i międzygatunkowych cząsteczek sygnałowych QS oraz procesów biologicznych regulowanych przez te cząsteczki
    Źródło:
    Acta Biologica; 2017, 24; 133-140
    2450-8330
    2353-3013
    Pojawia się w:
    Acta Biologica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication Of Colloidal Clusters Decorated With Dye Molecules For Potential Application As Photonic Molecules
    Wytwarzanie koloidalnych klasterów zdobionych cząsteczkami barwnika do potencjalnego zastosowania jako cząsteczki fotoniczne
    Autorzy:
    Cho, Y. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/356171.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    colloidal clusters
    fluorescent dyes
    photonic molecules
    particle self-assembly
    klaster koloidalny
    barwniki fluorescencyjne
    cząsteczki fotoniczne
    Opis:
    In this study, colloidal clusters decorated with fluorescent dyes were fabricated by evaporation-driven self-assembly using emulsion droplets as confining geometries. Silica microspheres were synthesized by Stober method followed by the modification with dye molecules through additional surface sol-gel reaction for the formation of thin silica shell. The surface of the resultant dye-doped silica microspheres was modified with hydrophobic silane coupling agent to disperse the particle suspension in organic solvent such as hexane. The fluorescent silica microspheres were self-assembled inside oil-in-water emulsions by evaporation-driven self-assembly for the formation of colloidal clusters, potentially applicable for photonic molecules. The clusters with fluorescent emission were observed using confocal microscope.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1221-1225
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Natalizumab: nowa droga w terapii stwardnienia rozsianego
    Natalizumab: a new way of multiple sclerosis therapy
    Autorzy:
    Jałosiński, Marcin
    Jatczak, Izabela
    Głąbiński, Andrzej
    Powiązania:
    https://bibliotekanauki.pl/articles/1059259.pdf
    Data publikacji:
    2007
    Wydawca:
    Medical Communications
    Tematy:
    natalizumab
    stwardnienie rozsiane
    leczenie immunomodulacyjne
    moleku³y adhezyjne
    integryny
    multiple sclerosis
    immunomodulation treatment
    adhesive molecules
    integrines
    Opis:
    Natalizumab (Tysabri®) is the first approved for therapy, commertially available selective antagonist of integrins. Integrins are glycoproteins belonging to adhesion molecules family, which play an important role in the process of cell adhesion. Natalizumab binds to α4 chain of integrins α4β1 and α4β7 present on the surface of almost all subpopulations of leukocytes. Blockade of interaction between integrin and its ligand prevents leukocyte transmigration through endothelium to the tissue site of inflammation. The clinical efficacy of natalizumab in remitting-relapsing MS was analyzed in two multicenter, randomized and placebo controlled third phase clinical trials: AFFIRM (Natalizumab Safety and Efficacy in RR-MS) and SENTINEL [Safety and Efficacy of Natalizumab in Combination with Avonex (IFN-β-1α) in Patients with MS). In AFFIRM trial natalizumab was evaluated in monotherapy, in SENTINEL study as add on therapy to IFN-β-1α. Both trials confirmed that natalizumab is beneficial in all analyzed endpoints. There was statistically significant decrease of relapse number and the risk of the disease progression. There was also beneficial influence of natalizumab therapy on the central nervous system (CNS) MRI parameters. After two years of therapy the number of gadolinium-enhanced MS plaques, as well as the number of the new and enlarging hyperintensive T2 plaques, was decreased. Because of the rare but serious side effect (progressive multifocal leukoencephalopathy, PML) the registration of natalizumab was suspended in June 2004. Detailed analysis of the results of both third phase clinical trials led to reapproval of natalizumab to therapy in June 2006. The strict criteria of patients’ inclusion to natalizumab therapy were established to minimize the risk of the serious side effects.
    Natalizumab (Tysabri®) jest pierwszym dostępnym komercyjnie lekiem będącym selektywnym antagonistą integryn. Integryny są glikoproteinami należącymi do grupy molekuł adhezyjnych i odgrywającymi istotną rolę w procesie adhezji komórkowej. Natalizumab wiąże się z podjednostką α4 integryn α4β1 i α4β7 obecnych na powierzchni prawie wszystkich leukocytów. Zablokowanie oddziaływania pomiędzy integryną i jej ligandem zapobiega transmigracji leukocytów przez śródbłonek do miejsca rozwoju reakcji zapalnej. Skuteczność leczenia stwardnienia rozsianego (SM) natalizumabem była oceniana w dwóch wieloośrodkowych, randomizowanych i kontrolowanych placebo badaniach klinicznych trzeciej fazy. Były to badania AFFIRM (Natalizumab Safety and Efficacy in RR-MS) oraz SENTINEL [Safety and Efficacy of Natalizumab in Combination with Avonex (IFN-β-Ια) in Patients with MS]. W pierwszym badaniu analizowano skuteczność natalizumabu w monoterapii SM, w drugim oceniano jego skuteczność w połączeniu z leczeniem IFN-β-Ια. Wykazano, iż terapia natalizumabem wpływała korzystnie na wszystkie analizowane parametry końcowe obu badań. Zaobserwowano istotny statystycznie spadek ilości rzutów SM oraz spadek ryzyka progresji tej choroby. Udowodniono również korzystny wpływ leczenia natalizumabem na obraz NMR ośrodkowego układu nerwowego. Po 2 latach terapii zaobserwowano spadek ilości plak Gd+, zmniejszenie liczby nowych plak oraz powiększających się plak hiperintensywnych w obrazach T2-zależnych. Ze względu na wystąpienie groźnego powikłania pod postacią postępującej wieloogniskowej leukoencefalopatii (PML) rejestracja natalizumabu została zawieszona w czerwcu 2004 r. Dokładna analiza wyników badań trzeciej fazy spowodowała przywrócenie rejestracji natalizumabu w czerwcu 2006 r. Ustalone zostały szczegółowe kryteria włączenia pacjentów do tego leczenia w celu zminimalizowania ryzyka wystąpienia poważnych efektów ubocznych.
    Źródło:
    Aktualności Neurologiczne; 2007, 7, 3; 195-201
    1641-9227
    2451-0696
    Pojawia się w:
    Aktualności Neurologiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kiedy identyczne oznacza identyczne
    When identical means identical
    Autorzy:
    Kijeńska, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1287422.pdf
    Data publikacji:
    2010
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
    Tematy:
    identyczność cząsteczek
    izomeria optyczna
    złamanie zasady parzystości
    identity of molecules
    optical isomerism
    violation of the parity law
    Opis:
    Artykuł z cyklu "Słoneczna chemia" ma za zadanie przybliżenie młodemu człowiekowi zagadnień związanych z szeroko pojętą identycznością cząsteczek chemicznych. Z jednej strony pokazuje identyczność cząsteczek niezależnie od źródła ich pozyskiwania, z drugiej uwrażliwia na fakt, że taki sam wzór chemiczny nie musi oznaczać takiej samej cząsteczki. Szeroko omówione jest zjawisko izomerii optycznej, wraz z praktycznymi implikacjami z niej wynikającymi. Autorka pokusza się także o spekulacje, czy mógłby istnieć i jak by wyglądał świat lustrzany do naszego.
    This paper of the "Sunny Chemistry" series is intended to familiarise a young man or woman with the problems of the broadly interpreted identity (sameness) of chemical molecules. It shows, on the one hand, the identity of molecules derived from various sources, and, on the other hand, it draws attention to the fact that the same chemical formula does not necessarily indicate an identical molecule. The phenomenon of optical isomerism is discussed extensively along with its practical implications. The author also speculates whether a mirror image of our world could exist and what would it look like.
    Źródło:
    Chemik; 2010, 64, 10; 631-640
    0009-2886
    Pojawia się w:
    Chemik
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Redoksowe przemiany oscylacyjne diftalocyjanin lantanowców pod wpływem protonodonorów i elektronoakceptorów
    Oscillating redox transformations of lanthanide diphthalocyanines due to proton donors and electron acceptors
    Autorzy:
    Wacławek, W.
    Dyrda, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/106356.pdf
    Data publikacji:
    2006
    Wydawca:
    Towarzystwo Chemii i Inżynierii Ekologicznej
    Tematy:
    przemiany oscylacyjne molekuł
    termodynamika nieliniowa
    diftalocyjaniny
    procesy redoks
    oscillating transformation of molecules
    nonlinear thermodynamics
    diphthalocyanines
    redox processes
    Opis:
    Diftalocyjaniny lantanowców LnPc2 (Ln = Nd, Eu, Gd lub Yb, Pc = (C32H16N8)2-) w obecności substancji elektronoakceptorowych (SE) w roztworze N,N-dimetyloformamidu (DMF) ulegają jedno- lub dwuelektronowemu utlenieniu. Reakcja w układzie LnPc2-SE-DMF jest procesem składającym się z kilku etapów, którym towarzyszą zmiany barwy układu. Początkowo niebieski roztwór (forma niebieska, [LnPc2]-) pod wpływem SE przechodzi w elektrycznie obojętną formę zieloną, LnPc2, a następnie w pomarańczową, [LnPc2]+. Po pewnym czasie następuje odtwarzanie formy zielonej. Z chwilą osiągnięcia maksimum intensywności formy zielonej następuje powrót do (niebieskiej) formy zredukowanej. Przemiany zachodzą samorzutnie. Można je opisać w ramach termodynamiki procesów nieodwracalnych. Szybkość tworzenia form przejściowych zależy od rodzaju zastosowanej substancji elektronoakceptorowej i jej stężenia.
    Lanthanide diphthalocyanines LnPc2 (Ln = Nd, Eu, Gd and Yb; Pc = (C32H16N8)2-) in the presence of H+, SnCl4, SO2 or NOx in DMF(N,N-dimethylformamide) solutions undergo cyclic, spontaneous, oscillating redox transformations accompanied by colour changes. These transformations are described in terms of nonlinear thermodynamics. The rate of those transformations is determined by the nature and concentration of chemical substance used to initiate them, as well as on UV irradiation.
    Źródło:
    Chemistry-Didactics-Ecology-Metrology; 2006, 11, 1-2; 21-33
    2084-4506
    Pojawia się w:
    Chemistry-Didactics-Ecology-Metrology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Natural Semantic Metalanguage as Terminology
    Autorzy:
    Bułat Silva, Zuzanna
    Powiązania:
    https://bibliotekanauki.pl/articles/2015041.pdf
    Data publikacji:
    2021
    Wydawca:
    Komisja Nauk Filologicznych Polskiej Akademii Nauk, Oddział we Wrocławiu
    Tematy:
    natural semantic metalanguage (NSM)
    semantic primes and molecules
    reductive paraphrase
    concrete and abstract nouns
    terms
    terminology
    ontology
    Opis:
    In this paper I present the Natural Semantic Metalanguage approach (Goddard & Wierzbicka 2014; Goddard 2018; Wierzbicka 1996, 2013), arguing that it can be perceived as a terminological system, a terminology sui generis. NSM is a decompositional approach to semantics, based on the assumption that there are 65 basic concepts, known as semantic primes, and that all other concepts can be paraphrased in terms of elements taken from this set of 65. These elements are said to exist in all human languages – as words, phrases or morphemes – and they cannot be reduced any further. The system has been tested on more than 30 different languages so far and is considered one of the most comprehensive approaches to cross-linguistic semantics today. I want to shed light on the formal structure of NSM, and explain its most important theoretical concepts, such as semantic primes and molecules, reductive paraphrase and semantic template, in order to demonstrate its practical value across many domains. As an example of how NSM is used in practice, I will look at the meaning of one concrete and one abstract noun (beach and comfort, respectively).
    Źródło:
    Academic Journal of Modern Philology; 2021, 13; 61-73
    2299-7164
    2353-3218
    Pojawia się w:
    Academic Journal of Modern Philology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mikrospektroskopia w podczerwieni z transformacją Fouriera w diagnostyce medycznej
    Fourier Transform Infrared Microspectroscopy in Medical Diagnostic
    Autorzy:
    Szczerbowska-Boruchowska, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/154757.pdf
    Data publikacji:
    2007
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    mikrospektroskopia w podczerwieni
    analiza topograficzna
    molekuły biologiczne
    diagnostyka medyczna
    infrared microspectroscopy
    synchrotron radiation
    topographic analysis
    biological molecules
    medical diagnostic
    Opis:
    Mikrospektroskopia w podczerwieni z transformacją Fouriera (FTIR) łączy w sobie dwie techniki badawcze, tj. spektroskopię w podczerwieni i mikroskopię. Umożliwia tym samym jednoznaczną analizę związków chemicznych w mikroobszarach badanego materiału. Szybki postęp techniki a przede wszystkim wykorzystanie synchrotronu jako źródła podczerwieni umożliwia prowadzenie badań z rozdzielczością przestrzenną rzędu pojedynczych mikrometrów. Oprócz oznaczeń składu chemicznego próbki istnieje również możliwość analizy topograficznej związków chemicznych zawartych w badanym materiale. Dzięki temu mikrospektroskopia w podczerwieni znalzła nowe zastosowanie jako narzędzie analityczne w badaniach tkanek i pojedynczych komórek. Niejednokrotnie jest wykorzystywana przez jednostki naukowe dla celów diagnostyki medycznej. Wśród zalet techniki jako narzędzia diagnostycznego należy wymienić możliwość rejestracji anomalii składu chemicznego z mikrometrową rozdzielczością przy minimalnej preparatyce próbek, nie wymagającej utrwalania materiału ani stosowania markerów biochemicznych. Niewielka ilość materiału wymagana do przeprowadzenia pomiaru może być pozyskana w sposób małoinwazyjny np. na drodze biopsji czy endoskopii. Szeroki nurt badań z wykorzystaniem mikrospektroskopii w podczerwieni do analizy tkanek i pojeynczych komórek stanowią aktualnie prace nad schorzeniami nowotworowymi, chorobami ośrodkowego układu nerwowego (choroby neurodegeneracyjne i prionowe), układu kostnego (osteoporoza, osteoartretyzm), chorobami serca i układu krwionośnego i in.
    Fourier Transform Infrared (FTIR) microspectroscopy combines two techniques i.e. IR spectroscopy and microscopy. Therefore it enables determining the chemical composition in small sample areas. Rapid technical advance especially application of synchrotron radiation as an infrared source allows to obtain micrometer spatial resolution in infrared spectroscopy. Apart from determination of chemical composition of specimens the topographic analysis of samples is also possible. Therefore FTIR microspectroscopy is applied as an analytical tool to investigation of tissues and single cells. This technique is frequently used as a diagnostic tool in medicine. One of the advantage of this technique is possibility of determination of abnormalities in chemical composition of specimen with minimal sample preparation i.e. without sample staining and applying biochemical markers. The small sample amount can be taken during biopsy or ednoscopy. Currently, infrared microspectroscopy is applied as a diagnostic tool in the following areas of medicine: cancer research, neurological disorders (neurodegenerations, prion diseases), bone diseases (osteoporosis, osteoarthritis), diseases of cardiovascular system and many others.
    Źródło:
    Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 444-447
    0032-4140
    Pojawia się w:
    Pomiary Automatyka Kontrola
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    EMG field analysis in dynamic microscopic/nanoscopic models of matter
    Analiza pola EMG w mikro/nanoskopowych modelach materii
    Autorzy:
    Fiala, Pavel
    Bartušek, Karel
    Dědková, Jarmila
    Dohnal, Premysl
    Powiązania:
    https://bibliotekanauki.pl/articles/408104.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
    Tematy:
    multiscaling
    modeling
    water
    cluster
    atom
    molecules
    structure
    matter
    low-level measurement
    modelowanie
    woda
    klaster
    cząsteczka
    budowa
    materia
    pomiar niskiego poziomu
    Opis:
    We discuss a numerical model (macro/micro/nanoscopic) to enable more accurate analysis of electro-hydro-dynamic (EMHD) processes in water at the level of atoms. Dedicated experiments have shown that inserting a relatively homogeneous periodic structure (deionized, degassed, or distilled H2O) in a magnetic field will influence the atomic basis, molecules, and relevant bonds. In this context, the present paper focuses on the designing, analysis, and evaluation of the behavior of an extensive system that represents H2O from the microscopic perspective, and it also outlines the properties and changes of the bonds in the examined water samples. Complementarily, a simple example is used to define the results obtained from analyses of the generated spiral static gradient magnetic and non-stationary gradient electromagnetic fields from the frequency range of f = 1 GHz to 10 GHz.
    W artykule przedyskutowano (makro/mikro/nanoskopowy) model numeryczny przeznaczony do dokładniejszej analizy procesów elektrohydrodynamicznych (EMHD) w wodzie na poziomie atomowym. Przeprowadzone w tym celu eksperymenty wykazały, że wprowadzenie względnie jednorodnej struktury okresowej (dejonizowanej, odgazowanej lub destylowanej wody w polu magnetycznym wpłynie na strukturę atomową, molekuły i odpowiednie wiązania. W tym kontekście niniejszy artykuł koncentruje się na projektowaniu, analizie i ocenie zachowania rozległego systemu, który reprezentuje H2O z perspektywy mikroskopowej, a także nakreśla właściwości i zmiany wiązań w badanych próbkach wody. Dodatkowo, zastosowano prosty przykład służy do definiowania uzyskanych wyników na podstawie analizy statycznych, spiralnych statycznych gradientowych i niestacjonarnych gradientowych pól elektromagnetycznych w zakresie częstotliwości od 1 GHz do 10 GHz.
    Źródło:
    Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2019, 9, 1; 4-10
    2083-0157
    2391-6761
    Pojawia się w:
    Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Density functional theory based modeling of the corrosion on iron surfaces
    Modelowanie korozji na powierzchni żelaza w oparciu o teorię funkcjonału gęstości
    Autorzy:
    Nunomura, N.
    Sunada, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/351628.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    density functional theory
    aqueous corrosion
    iron surface
    water molecules
    oxygen
    teoria funkcjonału gęstości
    korozja wodna
    powierzchnia żelaza
    cząsteczki wody
    tlen
    Opis:
    In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.
    W celu zrozumienia początkowych etapów korozji żelaza w środowisku wodnym wykonaliśmy obliczenia dla cząsteczek wody i powierzchni żelaza pokrytej tlenem przy użyciu teorii funkcjonału gęstości (DFT). Model struktury powierzchni zawiera warstwę atomów żelaza i obszar próżni, a następnie atomy tlenu i cząsteczki wody rozmieszczane na powierzchni. Obliczenia DFT wykonano w zastosowaniem bazy orbitali atomowych i metody pseudopotencjału zachowania normy (norm-conserve). Zgodnie z wynikami naszych obliczeń, ze wzrostem pokrycia powierzchni przez tlen, powierzchnia żelaza nie jest aktywowana, co prowadzi do słabej adsorpcji cząsteczek wody na powierzchni żelaza. Nasze wyniki wskazują, ze powierzchnia pokryta tlenem wywiera wpływ na adsorpcje cząsteczek wody na powierzchni żelaza.
    Źródło:
    Archives of Metallurgy and Materials; 2013, 58, 2; 321-323
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of nitrogen on thermodynamic properties and plasma composition in discharge tube of CO-laser
    Autorzy:
    Grigorian, G. M.
    Cenian, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/240382.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    CO-laser
    vibrational kinetics
    dissociation
    plasma-chemistry
    CN molecules
    C2
    electron kinetics
    dysocjacja
    chemia plazmy
    molekuły cyjanu
    kinetyka elektronów
    Opis:
    The role of the addition of nitrogen to the discharge plasma of CO lasers on thermodynamic properties and composition of the laser active medium is discussed here. It is shown that nitrogen addition improves laser characteristics and changes the composition of the laser active medium. The addition of nitrogen significantly decreases CO dissociation level and concentrations of C atoms created in plasma-chemical reactions of laser discharge.
    Źródło:
    Archives of Thermodynamics; 2016, 37, 3; 31-43
    1231-0956
    2083-6023
    Pojawia się w:
    Archives of Thermodynamics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Owrzodzenia podudzi i trudno gojące się rany
    Venous ulcers and difficult-to-heal wounds
    Autorzy:
    Citko, Anna
    Powiązania:
    https://bibliotekanauki.pl/articles/2138938.pdf
    Data publikacji:
    2022-06-01
    Wydawca:
    Wydawnictwo Naukowe Medyk sp. z o.o.
    Tematy:
    venous ulcers
    difficult-to-heal wounds
    TIME strategy
    TIAB molecules
    owrzodzenia podudzi
    rany trudno gojące się
    strategia TIME
    molekuła TIAB
    Opis:
    In Poland, the most common types of difficult-to-heal wounds include: venous ulcers, pressure ulcers, ulcers associated with the diabetic foot syndrome, ischemic (arterial) ulcers and neoplastic wounds. In the local management of chronic wounds, the TIME strategy should be used (T – tissue and debridement – tissue preparation; I – infection and inflammation control – infection and inflammation control; M – moisture balance – wound moisture balance; E – edges – wound edges – no healing progress or undermining the edge of the wound and epidermization stimulation). The TIME strategy pays particular attention to reducing the risk of wound infection. The treatment of TIAB molecules [titanum argentum-benzoicum] in the treatment of chronic wound infection may be among the measures taken to reduce the risk of chronic wound infection. The introduction of nanotechnology and the combination of ionic silver nanoparticles with titanium dioxide by covalent bonds in the TIAB complex, revolutionized the effect of silver, many times increasing its antibacterial and antifungal properties, and removing its toxic effect by preventing accumulation in tissues. The precipitation of metallic silver from ionic compounds resulted in the loss of activity of the preparations and, with prolonged use, could lead to tissue damage. The patented form of TIAB silver on the titanium core has only an ionic / stable form of silver which is not reduced by exposure to light, as well as organic and inorganic compounds. TIAB silver is available in the form of a spray and cream, and has a proven effect on pressure ulcers and ulcers that heal difficult to heal. At the same time, it does not show any allergy to silver with prolonged use. The use of the TIAB molecule in the treatment of ulcers with symptoms of colonization was presented at the congress of the European Wound Treatment Society in 2012 in Vienna as a new and highly effective solution.
    Źródło:
    Lek w Polsce; 2022, 373, 06; 8-14
    2353-8597
    Pojawia się w:
    Lek w Polsce
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oddziaływanie elektronów z cząsteczkami o biologicznym znaczeniu
    Interaction of electrons with biologically relevant molecules
    Autorzy:
    Kopyra, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/171628.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    dysocjacyjny wychwyt elektronów
    spektrometria mas
    jony ujemne
    cząsteczki o biologicznym znaczeniu
    dissociative electron attachment
    mass spectrometry
    negative ions
    biologically relevant molecules
    Opis:
    Recent years have witnessed an increase of the interest in the studies of the interaction of electrons with biologically relevant molecules. This has been mainly motivated by the seminal work, where it has been demonstrated that low energy electrons can induce single and double strand breaks in DNA in the energy range below the level of ionization. Since the damage profile as a function of electron energy showed pronounced resonances it was proposed that resonant electron capture could occur at particular molecular components of the DNA as the initial step towards strand breaks. From a series of experiments on electron attachment to DNA building blocks (nucleobases, the sugar moiety and the phosphate unit) became obvious that they effectively capture electrons leading to the formation of low energy resonances associated with the decomposition of the corresponding molecule. Recent dissociative electron attachment experiments on an entire gas phase nucleotide 2’-deoxycytidine-5´-monophosphate give also insight into the molecular mechanism involved, which comprises both direct electron attachment to the backbone and transfer of the excess electron from cytosine to the backbone resulting in single strand breaks. The results further allow an estimate of the relative contribution of these different mechanisms to single strand breaks.
    Źródło:
    Wiadomości Chemiczne; 2015, 69, 9-10; 893-907
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Strukturalne konsekwencje wiązania wodorowego
    Strustural consequences of the h-bonding
    Autorzy:
    Krygowski, T.M.
    Szatyłowicz, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/171995.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    wiązanie wodorowe
    podstawione fenole
    podstawione aniliny
    aromatyczność
    AIM
    NBO
    H-bond
    substituted phenols
    substituted anilines
    aromaticity
    atoms in molecules
    natural bond orbital
    NBO analysis
    Opis:
    Hydrogen bonding belongs to the most important chemical interactions in life and geochemical processes as well as in technologies, that is documented in many review articles [1-10], monographs [11-17] and numerous publications. Figure 1 presents how "popular" are studies concerning hydrogen bonds (the term H-bond/bonding/bonded in a title, key-words or in abstract) in the last decade. First information about H-bond formation appeared at the end of XIX and a few other at beginning of XX centuries [19-24]. Most common definition of H-bonding stems from Pauling [27], whereas the newest IUPAC definition was published very recently [26]. Most frequently H-bonding is experimentally described by geometry parameters [28, 32] - results of X-ray and neutron diffraction measurements, but NMR and IR/Raman spectroscopies are also in frequent use. Characteristic of interactions by H-bonding is usually discussed in terms of energies [29-31], with use of various quantum chemical theories [54-57] and applications of various models as AIM [35, 41, 42, 45-48] and NBO [43, 44] which allowed to formulate detailed criteria for H-bond characteristics [35, 48]. H-bonds are classified as strong, mostly covalent in nature [7, 29, 34], partly covalent of medium strength [35] and weak ones, usually non-covalent [7, 29, 34, 35]. Theoretical studies of H-bonding mainly concern equilibrium systems, however simulation of H-bonded complexes with controlled and gradually changing strength of interactions [61-71] are also performed. The latter is main source of data referring to effect of H-bonding on structural properties: changes in the region of interactions, short and long-distance consequences of H-bonding. Application of the model [61] based on approaching hydrofluoric acid to the basic center of a molecule and fluoride to the acidic one, (Schemes 2 and 3) allows to study changes in molecular structure of para-substituted derivatives of phenol and phenolate [62, 64] in function of dB…H, or other geometric parameter of H-bond strength (Fig. 2). It is also shown that CO bond lengths in these complexes is monotonically related to H-bond formation energy and deformation energy due to H-bond formation [65]. Alike studies carried out for para-substituted derivatives of aniline and its protonated and deprotonated forms [77, 78, 81] give similar picture (Fig. 3). AIM studies of anilines [77, 78] lead to an excellent dependence of logarithm of electron density in the bond critical point and geometric parameter of H-bond strength, dB…H presented in Figure 4. Substituents and H-bond formation affect dramatically geometry of amine group [66] in H-bonded complexes of aniline as shown by changes of pyramidalization of bonds in amine group (Fig. 5). Some short- and long-distance structural consequences of H-bonding are shown by means of changes in ipso angle (for amine group) in the ring and ipso-ortho CC bond lengths (Fig. 6). Moreover, the mutual interrelations are in line with the Bent-Walsh rule [84, 86]. Changes of the strength of H-bonds in complexes of p-substituted aniline and its protonated and deprotonated derivative are dramatically reflected by aromaticity of the ring66 estimated by use of HOMA index [87, 88] (Fig. 7), where strength of H-bonding is approximated by CN bond lengths. Scheme 4 presents application of the SESE [91] (Substituent Effect Stabilization Energy) for description in an energetic scale joint substituent and H-bond formation effects.
    Źródło:
    Wiadomości Chemiczne; 2011, 65, 11-12; 953-974
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Grzyby wielkoowocnikowe jako źródło substancji bioaktywnych
    Macrofungi as a source of bioactive substances
    Autorzy:
    Jasicka-Misiak, Izabela
    Powiązania:
    https://bibliotekanauki.pl/articles/172536.pdf
    Data publikacji:
    2020
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    grzyby wielkoowocnikowe
    substancje bioaktywne
    związki o niskiej masie cząsteczkowej
    związki o wysokiej masie cząsteczkowej
    macrofungi
    bioactive molecules
    low molecular weight compounds
    high molecular weight compounds
    Opis:
    From ancient times medicine and natural products have been closely linked through the use of traditional medicines and natural toxins. Macrofungi have an established history of use especially in traditional oriental medicine. Nowadays, mushrooms comprise a vast and yet largely untapped source of powerful new pharmaceutical products. In particular, and most importantly for modern medicine, they are an unlimited source of compounds that exhibit multidirectional activity: antioxidant, immuno-enhancing, immunostimulatory, antibacterial, antiviral, anti- inflammatory, antidiabetic, antiallergenic and anticarcinogenic [1, 2, 5-8]. In the presented work, a substances with biological activity from mainly Basidiomycota were reviewed, including low-molecular-weight (terpenoids, polyphenols steroids, quinones, amines, cerebrosides) (Tab.1) and high-molecular- weight compounds (homo and heteroglucans, glycans, glycoproteins, glycopeptides, peptides, proteins) (Tab. 2). Selected species of toxic and hallucinogenic mushrooms were also included in the review. At present, mushrooms are considered to be functional food. Beneficial health effects may be achieved through the direct consumption of fruiting bodies or the use of dietary supplements in the form of ready-to-use preparations containing mushroom extracts. The last years is also a period of a flourishing new field of medicine - mycopharmacology. The scientific approach to compounds contained in mushrooms allowed the isolation and identification of many valuable active substances which are used in the prevention and treatment of lifestyle diseases.
    Źródło:
    Wiadomości Chemiczne; 2020, 74, 1-2; 71-87
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparatwe EPR analysis of oxygen interactions with plants carbonized at different temperatures
    Autorzy:
    Bartłomiejczyk, S.
    Pilawa, B.
    Krzesińska, M.
    Pusz, S.
    Zachariasz, J.
    Wałach, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/284848.pdf
    Data publikacji:
    2008
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
    Tematy:
    karbonizacja roślin
    centra paramagnetyczne
    paramagnetyczne utlenianie cząsteczek
    elektroniczny rezonans paramagnetyczny
    widma EPR
    oksymetria
    carbonized plants
    paramagnetic centers
    paramagnetic oxygen molecules
    electron paramagnetic resonance
    EPR spectra
    oximetry
    Opis:
    Carbon materials, bamboo (Bambusa vulagris) and yucca (Yucca flaccida) pyrolysed at 550°C, 750°C and 950°C, were tested as oximetric probes by electron paramagnetic resonance spectroscopy at X-band (9.3 GHz). The following parameters of the spectra: amplitude, linewidth and g-factor, were determined. Influence of oxygen molecules 02 on EPR spectra of the individual carbon materials was compared. Strong EPR spectra were recorded for samples carbonized at 550°C and weak signals were obtained for plants carbonized at higher temperatures: 750°C and 950°C. It was stated that amplitudes of EPR lines of all the carbonized plants decrease in the air environment compared to amplitudes of spectra measured in vacuum. This effect increases with degree of vacuum. Changes in the EPR spectra of samples studied in the air environment may be applied in medicine to determination of oxygen content in different cells. Because of strong resonance signals as oximetric probes we proposed bamboo and yucca carbonized at 550°C, and we rejected plants carbonized at 750°C and 950°C with Iow EPR signals.
    Źródło:
    Engineering of Biomaterials; 2008, 11, 73; 3-5
    1429-7248
    Pojawia się w:
    Engineering of Biomaterials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Boiling, steaming or rinsing? (the physics of chinese cuisine)
    Gotować, gotować na parze czy może płukać? (fizyka kuchni chińskiej)
    Autorzy:
    Varlamov, A.
    Zhou, Z.
    Chen, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/129558.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
    Tematy:
    complex organic molecules
    proteins
    damplings
    heat transfer
    temperature conductivity
    Fourier law
    Newton's law of cooling
    złożone molekuły organiczne
    proteiny
    kluski
    przenoszenie ciepła
    przewodnictwo temperaturowe
    prawo Fouriera
    Newtonowskie prawo chłodzenia
    Opis:
    Some physical aspects of Chinese cuisine are discussed. We start from the cultural and historical particularities of Chinese cuisine and their food production technologies. What is the difference between raw and boiled meat? What is the difference in the physical processes of heat transfer during either the steaming of dumplings or during cooking them in boiling water? Why is it possible to cook meat stripes in a "hot pot" in ten seconds, whilst baking a turkey requires several hours? This article is devoted to a discussion of these questions.
    W artykule zostały przedyskutowane niektóre aspekty kuchni chińskiej. Autorzy zaczynają od omówienia szczegółów kuchni chińskiej i technologii produkcji żywności. Autorzy zadają następujące pytania: jaka jest różnica pomiędzy mięsem surowym a gotowanym? Jaka jest różnica w fizyce procesu przenoszenia ciepła podczas przyrządzania klusków na parze wodnej a w gotującej się wodzie? Dla czego jest możliwe przyrządzanie kawałków mięsa w "gorącym garnku" w ciągu kilku sekund, podczas gdy po to, aby upiec indyka potrzebujemy kilku godzin? Artykuł ten udziela odpowiedzi na te i inne pytania.
    Źródło:
    Physics for Economy; 2018, 2, No.1; 55-68
    2544-7742
    2544-7750
    Pojawia się w:
    Physics for Economy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Charakterystyka mocy poszczególnych wiązań wodorowych w parach zasad DNA
    Characterizing strength of individual hydrogen bonds in DNA base-pairs
    Autorzy:
    Szatyłowicz, Halina
    Sadlej-Sosnowska, Nina
    Jezierska, Aneta
    Powiązania:
    https://bibliotekanauki.pl/articles/172292.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    wiązanie wodorowe
    pary zasad Watsona-Cricka
    NBO
    koncepcja naturalnych orbitali wiązań
    AIM
    metoda atomy w cząsteczce
    hydrogen bond
    Watson-Crick base pairs
    natural bond orbital method
    atoms in molecules
    Opis:
    The main idea of the current review is to present methods useful to characterize the strength of individual hydrogen bonds in nucleic acids base-pairs. In the paper, the Authors discuss the energy definition of intermolecular interactions taking into account the presence of one intermolecular hydrogen bond (HB) as well as the situation when several intermolecular interactions (namely intermolecular hydrogen bonds) are present. In the Section 2 of the review a general overview of methods developed to estimate the strength of the individual intermolecular hydrogen bond in DNA/RNA base-pairs is presented. Thus, the reader can find detailed information on the methods used so far: the rotational method (2003), compliance constants method (2004), the EML equation application (2006), the atom replacement method (2007), the estimation of hydrogen bond energy on the basis of electron density (calculated by using the AIM theory) at BCP values (2009), the application of NBO method (2010), the comparison of HB strength based on the last two approaches (2015) and the application of coordinates interaction approach (2017). It should be emphasized, that these methods allow to estimate the strength of intermolecular interactions both in the model base-pairs and in other systems with several intermolecular hydrogen bonds. The discussion of the presented methods is supported by Tables 1-10, containing numerical values characteristics of the strength of the particular HB, and Figures 1–2. The section 3 contains a critical comparison of results based on the presented methods. Concluding remarks are given in the last Section.
    Źródło:
    Wiadomości Chemiczne; 2019, 73, 1-2; 53-74
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zastosowanie topologicznej analizy gęstości elektronowej do opisu oddziaływań niekowalencyjnych
    The use of topological analysis of electron density in characterization of noncovalent interactions
    Autorzy:
    Bankiewicz, B.
    Rybarczyk-Pirek, A.
    Małecka, M.
    Domagała, M.
    Palusiak, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/172723.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    Kwantowa teoria Atomów w Cząsteczkach
    QTAIM
    gęstość elektronowa
    analiza topologiczna
    wiązanie chemiczne
    oddziaływanie niekowalencyjne
    Quantum Theory of Atoms in Molecules
    electron density
    topological analysis
    chemical bonding
    noncovalent bonding
    Opis:
    All atomic and molecular properties are governed by an electron density distribution. Thus, the methods that deal with an analysis of the electron density distribution should have a particular appeal for chemists and help to understand the electron structure of molecules. The Quantum Theory of Atoms in Molecules gives the unique opportunity to have an insight into a region (e.g., an atom) of a given system (e.g. a molecule), delivering partitioning scheme which is defined explicitly within the rigorous quantum theory, from one side, and is applicable for experimentally available set of observables, from the other side. In that way QTAIM delivers a chemist a theoretical tool to study a small part of a molecule only, instead of dealing with the total energy of a whole system. In consequence, QTAIM has become one of the most powerful utilities of modern chemistry, forming a bridge between advanced theoretical and experimental techniques. In particular the properties of the electron density function in the so-called bond critical point (BCP, the (3, -1) saddle point on electron density curvature) seem to be valuable information for chemists, since it was proven in many papers that the chemical bonding can be characterized and classified on the basis of electron density characteristics measured in BCPs . In this review we firstly give a brief introduction to the theory, explaining most basic terms and dependences. In the main part of the review we discuss application of QTAIM in the qualitative and quantitative analysis of several various noncovalent interactions, focusing readers attention on such aspects as classification of interactions and interaction energy assessment. Both theoretical and experimental approaches are taken into account. We also discuss extensions of QTAIM to the analysis of the so called source function – the method which additionally enlarge interpretative possibilities of its parent theory. Finally, we give some examples which perhaps escape a rigorous QTAIM definition of chemical bonding. We acquaint the potential reader with arguments being pro- and against the QTAIM-based deterministic model of a chemical bond.
    Źródło:
    Wiadomości Chemiczne; 2014, 68, 5-6; 457-486
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wiązanie wodorowe i inne oddziaływania typu kwas Lewisa-zasada Lewisa
    The hydrogen bond and the other Lewis acid-Lewis base interactions
    Autorzy:
    Grabowski, S. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/171998.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    wiązanie wodorowe
    wiązanie halogenowe
    wiązanie wodorkowe
    oddziaływanie kwas Lewisa-zasada Lewisa
    teoria Atomy w Cząsteczkach
    hydrogen bond
    halogen bond
    hydride bond
    Lewis acid-Lewis base interaction
    atoms in molecules theory
    AIM
    Opis:
    Hydrogen bond is analyzed very often since its importance in numerous chemical, physical and biological processes is very well known. It covers the broad range of various interactions; sometimes this is the subject of discussions and polemics if some of them may be classified as hydrogen bonds. This is because there are numerous definitions of hydrogen bond interaction, often they are hardly accepted since they are not univocal. For example one can mention different types of the proton acceptors for hydrogen bonds; one center electronegative atoms, multi-center acceptors such as đ-electrons or even ó-electrons. There are the other interactions which play the key role in various processes and phenomena. All are often named as no-covalent interactions but the other term, Lewis acid–Lewis base interactions seems to be more accurate. One can mention halogen bond, hydride bond or dihydrogen bond. These interactions may be treated as counterparts or competitors of hydrogen bond. The common characteristic for them, including hydrogen bond, is the electron charge transfer from the Lewis base to the Lewis acid. It was found that the amount of this transfer corresponds roughly to the strength of the interaction. In recent years the ó-hole concept was introduced and developed and it was applied to the Lewis base–Lewis acid interactions. According to this concept the atomic centers are characterized by the presence of the regions of positive and negative electrostatic potentials; very often both regions are detected even for atoms which are commonly known as electronegative ones. In such a way halogen atoms, especially if connected by covalent bond with carbon, may act as Lewis acids and also as Lewis bases. In the first case the halogen bond is formed, recently extensively studied. In this review the characteristics of different Lewis base–Lewis acid interactions are given as well as their common features are presented.
    Źródło:
    Wiadomości Chemiczne; 2011, 65, 11-12; 975-1001
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Monte Carlo fitting of data from muon catalyzed fusion experiments in solid hydrogen
    Dopasowanie metodą Monte Carlo danych z eksperymentów katalizy mionowej w zestalonym wodorze
    Autorzy:
    Filipowicz, M.
    Bystritsky, V.M.
    Woźniak, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/305341.pdf
    Data publikacji:
    2008
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    dopasowywanie danych
    symulacja Monte Carlo
    estymator chi-kwadrat
    obliczenia gradientu
    symulacja dyfuzji
    atomy i molekuły mionowe
    data fitting
    Monte Carlo simulation
    chi-square estimator
    gradient calculation
    diffusion simulation
    muonic atoms and molecules
    Opis:
    Applying the classical chi-square fitting procedure for multiparameter systems is in some cases extremely difficult due to the lack of an analytical expression for the theoretical functions describing the system. This paper presents an analysis procedure for experimental data using theoretical functions generated by Monte Carlo method, each corresponding to definite values of the minimization parameters. It was applied for the E742 experiment (TRIUMF, Vancouver, Canada) data analysis with the aim to analyze data from Muon Catalyzed Fusion experiments (extraction muonic atom scattering parameters and parameters of pd fusion in pdµ molecule).
    Zastosowanie klasycznej procedury fitowania przy użyciu estymatora chi-kwadrat jest w pewnych przypadkach bardzo trudne z powodu braku analitycznych wyrażeń na teoretyczne funkcje opisujące system. W pracy zaprezentowano procedurę analizy danych eksperymentalnych przy użyciu teoretycznych funkcji generowanych metodą Monte Carlo, odpowiadających zdefiniowanym wartościom szukanych parametrów. Analiza została zastosowana dla eksperymentu E742 (TRIUMF, Vancouver, Kanada) w celu opisu danych pochodzących z syntezy jądrowej katalizowanej mionami (uzyskanie parametrów opisujących rozpraszanie atomów mionowych i parametrów syntezy pd w molekule pdµ).
    Źródło:
    Computer Science; 2008, 9; 11-20
    1508-2806
    2300-7036
    Pojawia się w:
    Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Mathematical Model of Membrane Gas Separation with Energy Transfer by Molecules of Gas Flowing in a Channel to Molecules Penetrating this Channel from the Adjacent Channel
    Autorzy:
    Szwast, M.
    Szwast, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/185043.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    membrane
    membrane module
    reciprocal transfer of energy between gas molecules
    changes of the pressure of gas along the length of flow channel
    membrana
    wzajemne przekazywanie energii między cząsteczkami gazu
    zmiany ciśnienia gazu na długości kanału przepływowego
    Opis:
    The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels – the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both – the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculationsobtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.
    Źródło:
    Chemical and Process Engineering; 2015, 36, 2; 151-169
    0208-6425
    2300-1925
    Pojawia się w:
    Chemical and Process Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    QS – systems communication of Gram-positive bacterial cells
    Autorzy:
    Ziemichód, Alicja
    Skotarczak, Bogumiła
    Powiązania:
    https://bibliotekanauki.pl/articles/1386088.pdf
    Data publikacji:
    2017
    Wydawca:
    Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
    Tematy:
    Quorum sensing
    Gram-positive bacteria
    signaling molecules
    gene expression
    competence of Streptococcus pneumoniae and Bacillus subtilis
    virulence of Staphylococcus aureus
    quorum sensing
    bakterie Gram dodatnie
    cząsteczki sygnałowe
    ekspresja genów
    kompetencja Streptococcus pneumoniae i Bacillus subtilis
    wirulencja Staphylococcus aureus
    Opis:
    In Gram-positive bacteria, cell-to-cell communication, also called quorum sensing (QS) mainly is dependent on extracellular signaling oligopeptide pheromones, which stimulate a response either indirectly, by activating a two-component phosphorelay, or directly, by binding to cytoplasmic effectors. The oligopeptide pheromones production and secretion are initiated in response to specific environmental stimuli or stresses. These pheromones are biosynthesized through different pathways and some have unusual functional chemistry as a result of posttranslational modifications. In the cells of Bacillus subtilis and Streptococcus pneumoniae this system controls the acquisition of the state of competence, while in Staphylococcus aureus it regulates virulence. The review aims at giving an updated overview of these peptide-dependant communication pathways.
    U bakterii Gram dodatnich komunikacja od komórki do komórki, zwana także guorum sensing (QS) jest przede wszystkim zależna od zewnątrzkomórkowych sygnałowych oligopeptydowych feromonów, które stymulują odpowiedź także pośrednio poprzez aktywowanie dwuskładnikowych fosforanów lub bezpośrednio przez wiązanie efektorów cytoplazmatycznych. Wytwarzanie i wydzielanie feromonów oligopeptydowych jest inicjowane w odpowiedzi na specyficzne czynniki środowiskowe lub stres. Feromony są syntetyzowane różnymi drogami a niektóre mają jeszcze dodatkową funkcję chemiczną jako wynik modyfikacji potranslacyjnej. W komórkach Bacillus subtilis i Streptococcus pneumoniae ten system kontroluje nabycie stanu kompetencji, natomiast u Staphylococcus aureus reguluje wirulencję. Celem pracy był przegląd aktualnych danych dotyczących peptydozależnych dróg komunikacji.
    Źródło:
    Acta Biologica; 2017, 24; 51-56
    2450-8330
    2353-3013
    Pojawia się w:
    Acta Biologica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modification of solid substrates by controlled adsorption of macroions
    Modyfikacja substratów stałych przez kontrolowaną adsorpcję makrojonów
    Autorzy:
    Morga, Maria
    Adamczyk, Zbigniew
    Powiązania:
    https://bibliotekanauki.pl/articles/1853726.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    adsorption of macroions
    electrokinetic characteristics of macroions
    PAH and PDDA adsorption
    macroion layers on solid substrates
    streaming potential measurements
    zeta potential of macroion molecules
    adsorpcja makrojonów
    charakterystyka makrojonów
    adsorpcja PAH i PDDA
    warstwa makrojonów na powierzchniach ciał stałych
    pomiary potencjału przepływu
    potencjał zeta makrocząstek
    Opis:
    Mechanisms of cationic macroion adsorption on negatively charged solid substrates comprising mica and silica were thoroughly discussed. Attention was focused on poly(allylamine hydrochloride) (PAH), poly(dimethyl-diallylammonium chloride) (PDDA) and poly-L-lysine (PLL) widely used in practice. The bulk physicochemical parameters controlling the macroion adsorption such as the diffusion coefficient, hydrodynamic diameter, intrinsic viscosity and electrophoretic mobility were discussed. The latter, experimentally accessible parameter, enables to determine the electrokinetic charge of macroion molecules, their isoelectric points and zeta potentials. On the other hand, the analysis of the hydrodynamic diameter and the intrinsic viscosity data confirmed a largely elongated shape of the molecules even for concentrated electrolyte solution. These results are used for a quantitative interpretation of macroion adsorption at solid substrates investigated using in situ streaming potential measurements. It is confirmed that the macroion mostly adsorb in the side-on orientation forming layers whose maximum coverage can be regulated by the ionic strength of the solution. This streaming potential method can also be used to determine the stability of the layers performing controlled desorption kinetic measurements. It is shown that at pH 7.4 the PDDA and PLL macroions form stable layers on solid substrates, which can be used for an efficient immobilization of negatively charged macroions and bioparticles comprising protein molecules and viruses.
    Źródło:
    Wiadomości Chemiczne; 2021, 75, 9-10; 1157-1179
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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