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Tytuł:
Analiza porównawcza wyników oznaczeń laboratoryjnych biomarkerów zapalenia – wskaźnika sedymentacji krwinek czerwonych (ESR) i białka C-reaktywnego (CRP) w stanach zapalnych u pacjentów hospitalizowanych
Comparative analysis of inflammatory biomarkers values - erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in hospitalized patients with inflammation
Autorzy:
Siudzińska, Agnieszka
Łobos, Marek
Sujecki, Adam
Paradowski, Marek
Powiązania:
https://bibliotekanauki.pl/articles/1032623.pdf
Data publikacji:
2013
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
CRP
ESR
inflammation
zapalenie
esr
crp
Opis:
Introduction: Erythrocyte sedimentation rate (ESR, in Poland known as OB) and C-reactive protein (CRP) are biomarkers most often used to diagnose and monitor systemic inflammation. However, they are independent markers and have different properties. The aim of this study was to compare the values of specific markers of systemic inflammation such as ESR and CRP in patients hospitalized in the internal wards and suspected of suffering from systemic inflammation. Material and methods: The study group included 187 patients (99 women and 88 men, aged from 20 to 97 years) hospitalized in the internal medicine clinics of the Military Medical Academy University Teaching Hospital - Central Veterans' Hospital in Lodz. Each marker of inflammation, ESR and CRP, were measured in patients’ peripheral blood (ESR) and serum (CRP). Results: For the diagnosis of inflammation there was no significant correlation between CRP and ESR in groups of patients both with mild (CRP > 6.1 – 40 mg/L) and severe (CRP ≥ 40.1) inflammation. However, in persons with highly developed inflammation (ESR ≥ 31 mm/h and CRP ≥ 40.1 mg/L) there was a strong correlation between the mentioned biomarkers (r = 0.9973). Conclusions: The results indicate that CRP and ESR biomarkers are independent parameters that are clinically useful for the diagnosis and monitoring of inflammations. For the diagnosis of acute inflammation the designation of serum CRP is clinically more useful than the measurement of ESR.
Wstęp: Odczyn opadania krwinek czerwonych (ESR, w Polsce znany pod nazwą odczyn Biernackiego - OB) i stężenie białka C-reaktywnego (CRP) są najczęściej wykorzystywanymi przez lekarzy biomarkerami do rozpoznawania i monitorowania stanu zapalnego ustroju. Jednak są one wskaźnikami niezależnymi i cechują się różnymi własnościami. Celem niniejszej pracy była analiza porównawcza wyników oznaczeń dwóch laboratoryjnych biomarkerów zapalenia: ESR i CRP u pacjentów leczonych na oddziałach internistycznych, u których podejrzewano narastający lub istniejący proces zapalny. Materiał i metody: Badaniem objęto 187 chorych (99 kobiet i 88 mężczyzn, w wieku od 20 do 97 lat) hospitalizowanych w klinikach chorób wewnętrznych Uniwersyteckiego Szpitala Klinicznego im. Wojskowej Akademii Medycznej – Centralnego Szpitala Weteranów w Łodzi. U każdego pacjenta w tym samym czasie wykonano oznaczenie dwóch wskaźników stanu zapalnego: ESR i CRP. Wyniki: Dla rozpoznawania narastającego zapalenia nie wykazano istotnej korelacji między CRP i ESR w grupach pacjentów zarówno o małym (CRP > 6,1 – 40 mg/L), jak i dużym (CRP ≥ 40,1) nasileniu zapalenia. Z drugiej strony, u ludzi z silnie już rozwiniętym zapaleniem (ESR ≥ 31 mm/h i CRP ≥ 40,1 mg/L) zaznaczyła się wysoka korelacja pomiędzy tymi biomarkerami (r = 0,9973). Wnioski: Wyniki wskazują, że analizowane biomarkery CRP i ESR są parametrami niezależnymi i są klinicznie użyteczne w rozpoznawaniu i obserwacji stanów zapalnych. W rozpoznawaniu zapalenia o ostrym przebiegu bardziej użytecznym klinicznie biomarkerem jest stężenie CRP w surowicy niż wartość ESR.
Źródło:
Folia Medica Lodziensia; 2013, 40, 2; 207-233
0071-6731
Pojawia się w:
Folia Medica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taurine-EVA copolymer-paraffin rods dosimeters for EPR high-dose radiation dosimetr
Autorzy:
Maghraby, A. M.
Mansour, A.
Abdel-Fattah, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/147366.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EPR
ESR
radiation dosimetry
taurine
alanine
Opis:
Taurine/EPR rods (3 × 10 mm) have been prepared by a simple technique in the laboratory where taurine powder was mixed with a molten mixture of paraffin wax and an ethylene vinyl acetate (EVA) copolymer. The binding mixture EVA/Paraffin does not present interference or noise in the EPR signal before or after irradiation. The rods show good mechanical properties for safe and multi-use handling. An EPR investigation of radiation induced radicals in taurine rods revealed that there are two types of radicals produced after exposure to gamma radiation (60Co). EPR spectra were recorded and analyzed – also the microwave power saturation and modulation amplitude were studied and optimized. Response of taurine to different radiation doses (1.5–100 kGy) was studied and found to follow a linear relationship up to 100 kGy. Radiation induced radicals in taurine persists and showed a noticeable stability over 94 days following irradiation. Uncertainities associated with the evaluation of radiation doses using taurine dosimeters were discussed and tabulated. It was found that taurine possesses good dosimetric properties using EPR spectroscopy in high doses in addition to its simple spectrum.
Źródło:
Nukleonika; 2014, 59, 1; 9-13
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of humic substances on the liposome structures : ESR method
Autorzy:
Man, D.
Pisarek, I.
Braczkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/147392.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EYL liposome
ESR method
humic substances
Opis:
In this paper the changes of membrane fluidity of liposome with additions of humic substances (humic and fulvic acids) were examined. Liposome were done by the sonication of lecithin EYL. Concentrations of humic substances in attitude to EYL varied between 0–10% of weight. The technique of electron spin resonance (ESR) were used for the examination followed by three spin probes with a variety placement of the membrane located. TEMPO probe melted in the hydrophobic membrane and in the aquatic solution which allowed to determine the spectroscopic partition parameter (F), indicating the changes that occur in water-lipid interphase. Probe 5-DOXYL placed directly under the heads of polar lipids and the order parameter measuring by the TII showed the changing of membrane fluidity at surface area. 16-DOXYL probe penetrated the middle of the lipid bilayer membrane and allowed to determine the rotational correlation time τ parameter, which gives us information about changing of the liquidity lipid bilayer. Studies showed that the tested humic substances significantly changed the membrane fluidity of liposome. The dynamics of this process depends on both: the fraction of humic substances and its quality and quantity as well as the placement area of the membrane.
Źródło:
Nukleonika; 2013, 58, 3; 439-442
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Capacitor & Diode Aging effects on Output Ripple in Voltage Regulators and Prognostic Detection of Failure
Autorzy:
K, Preethi Sharma
Vijayakumar, T
Powiązania:
https://bibliotekanauki.pl/articles/2055277.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Buck
MOSFET
ESR
SMPS
voltage ripple
Opis:
Objectives: To design and simulate a buck converter and detector circuit which can prognostically indicate the power supply failure. Failure of Aluminium Electrolytic Capacitor (AEC) is considered as the parameter causing the power supply failure. To analyse variation of output ripple voltage due to possible changes in the Equivalent Series Resistance (ESR) and effective capacitance of the capacitor and design a detector to detect the failure of power supply prognostically. Methods: A DC-DC buck converter in SMPS topology is designed by assuming an input voltage of 12V with 3 volts possible fluctuations and an output voltage of 3.3 volts is desired. Simulation is carried out to measure the variation in output ripple voltage caused due to aging of electrolytic capacitor using TINA by Texas Instruments. A detector is also designed to compare the ripple voltage and a predefined threshold voltage so as to indicate the possible failure of Switched Mode Power Supply (SMPS) well in advance by monitoring the output ripple increase. Novelty: Having a fault tolerant power supply is very important in safety critical applications. Here by monitoring the output ripple variation, the degradation of AEC is predicted by calculating the ESR and capacitance variation. This simple yet effective prognostic detection will support in the design of fault tolerant power supplies. Highlight: It is found that, the ripple at the output increases with aging of the electrolytic capacitor, as with time the equivalent capacitance decreases and Equivalent Series Resistance (ESR) of the capacitor increases. The designed detector output is found to prognostically indicate the failure of SMPS.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 2; 281--286
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of humic acids on EYL liposome membranes : ESR method
Autorzy:
Pytel, B.
Filipiak, A.
Pisarek, I.
Olchawa, R.
Man, D.
Powiązania:
https://bibliotekanauki.pl/articles/146924.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EYL liposomes
ESR method
humic substances
Opis:
In this paper, the effects of model (commercial) and natural (extracted from peat) humic substances on the membrane of liposomes formed with egg yolk lecithin (EYL) are presented. In our research, mass concentrations of fulvic and humic acids were used, which in relation to lecithin varied from 0% to 13%. To study membrane fluidity, electron spin resonance (EPR) was used with two spin probes, penetrating various regions of the lipid bilayer. The effects of model and natural humic substances (humic acids – HAs and fulvic acids – FAs) on the lipid membrane in different regions were researched: the lipid-water interphase, and in the middle of the lipid bilayer. It was shown that FA and HA impact the fluidity of liposome membranes in different ways. Increased mass concentrations of HAs decreased membrane fluidity in both acids: extracted from peat and the model. However, increased mass concentration of FAs extracted from peat, decreased membrane fluidity in the surface region, at the same time stiffening the central part of the bilayer. Increasing the concentration of FAs extracted from peat had the opposite effect when compared to model FA. This effect may be related to the complexation of xenobiotics present in the soil environment and their impact on biological membranes.
Źródło:
Nukleonika; 2015, 60, No. 3, part 1; 455-459
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Paramagnetic properties of Cuban red mud at low temperatures
Autorzy:
Shvets, V.
Powiązania:
https://bibliotekanauki.pl/articles/184300.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
iron ores
metals oxides
ESR
low temperatures
Opis:
The electron spin resonance (ESR) spectra of Cuban red mud have been measured at three different temperatures: 295 K, 150 K and 77 K. The broad absorption line with resonance fields ∼(1.7–1.8) kOe was observed at all temperatures with values of g-factor from 3.602 to 4.020. The temperature decrease resulted in an absorption line appearance with resonance fields of 3.252 kOe (g = 2.067) at 150 K and 3.339 kOe (g = 2.086) at 77 K. The ESR-signal amplitude with resonance fields ∼(1.7–1.8) kOe decreases and the ESR-signal amplitude in the field ∼3.3 kОе increases with reduction in temperature.
Źródło:
Geology, Geophysics and Environment; 2018, 44, 4; 373-378
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin trapping studies of essential oils in lipid systems
Autorzy:
Makarova, K.
Drązikowska, K.
Suska, B.
Zawada, K.
Wawer, I.
Powiązania:
https://bibliotekanauki.pl/articles/147786.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
spin trapping ESR
essential oils
DFT calculations
lipids
Opis:
In the present work, we report the results of a spin trapping ESR study of four essential oils widely used for skin care products such as creams and bath salts. The studied essential oils are Rosmarini aetheroleum (rosemary), Menthae piperitae aetheroleum (mint), Lavandulae aetheroleum (lavender), and Thymi aetheroleum (thyme). Fenton reaction in the presence of ethanol was used to generate free radicals. The N-tert- -butyl-α-phenylnitrone (PBN) was used as a spin trap. In the Fenton reaction, the rosemary oil had the lowest effect on radical adduct formation as compared to the reference Fenton system. Since essential oils are known to be lipid soluble, we also conducted studies of essential oils in Fenton reaction in the presence of lipids. Two model lipids were used, namely 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn- -glycero-3-phosphocholine (DPPC). The obtained results suggested that in the presence of DOPC lipids, the •OH and PBN/•CHCH3(OH) radicals are formed in both phases, that is, water and lipids, and all the studied essential oils affected the Fenton reaction in a similar way. Whereas, in the DPPC system, the additional type of PBN/X (aN = 16.1 G, aH = 2.9 G) radical adduct was generated. DFT calculations of hyperfi ne splittings were performed at B3LYP/6-311+G(d,p)/EPR-II level of theory for the set of c-centered PBN adducts in order to identify PBN/X radical.
Źródło:
Nukleonika; 2015, 60, No. 3, part 1; 461-468
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectroscopic interpretations of Co(II), Ni(II) and Cu(II) decxycholate complexes with molecular docking of COVId-19 protease
Autorzy:
Refat, Moamen S.
Bakare, Safyah B.
Altalhi, Tariq A.
Alam, Kehkashan
Al-Hazmi, Ghaferah H.
Powiązania:
https://bibliotekanauki.pl/articles/1849269.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
deoxycholic acid
complexes
ESR
TGA/DSC
molecular docking
Opis:
Co(II), Ni(II) and Cu(II) decxycholate complexes are interesting due to their biologically active and deliberate interest in the research due to their coordination properties. The microanalytical ‘elemental analysis’, molar conductivity, (infrared and Raman) spectroscopy, thermal analyses (TGA/DSC), UV-vis spectra, and ESR for copper(II) decxycholate complex investigations were performed in the structural assignments of Co(II), Ni(II) and Cu(II) decxycholate complexes. Reaction of the sodium deoxycholate ligand (C24H39O4Na) with three transition metal ions form the complexes of formulae, [M(C24H39O4)2(H2O)2] . xH2O where M = Co(II), Ni(II) and Cu(II) where x = 2 for Cu(II) and x = 4 in case of M = Co(II) or Ni(II) metal ions. The FTIR spectra of the complexes show that decxycholate molecule is present as bidentate ligand. Molecular docking utilizing to additionally examine the interaction of COVID-19 (6LU7) with different complexes of deoxycholic acid with Co(II), Ni(II) and Cu(II). Furthermore, in the case of Co(II) deoxycholate complex, the probe is surrounded by amino residues Met235, Pro241, Glu240, Pro108, Gln110, Phe294, and Ile152. The probe molecule of Ni(II) deoxycholate complex is sited close to amino acids Tyr126, Tyr239, Leu287, Leu272, and Lys137. For, Cu(II) deoxycholate complex, the residues of amino acids comprise of Pro132, Pro108, Gln110, Gly109, Ile200, Asn203, Val202, His246, Pro293 and Tyr154. The binding energy was determined from the docking reads for Co(II)–6LU7, Ni(II)–6LU7 and Cu(II)–6LU7 deoxycholate compounds were found to be −446.99, −500.52, −398.13 kcal mol−1 individually.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 2; 54-59
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectroscopic interpretations of Co(II), Ni(II) and Cu(II) decxycholate complexes with molecular docking of COVId-19 protease
Autorzy:
Refat, Moamen S.
Bakare, Safyah B.
Altalhi, Tariq A.
Alam, Kehkashan
Al-Hazmi, Ghaferah H.
Powiązania:
https://bibliotekanauki.pl/articles/1849271.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
deoxycholic acid
complexes
ESR
TGA/DSC
molecular docking
Opis:
Co(II), Ni(II) and Cu(II) decxycholate complexes are interesting due to their biologically active and deliberate interest in the research due to their coordination properties. The microanalytical ‘elemental analysis’, molar conductivity, (infrared and Raman) spectroscopy, thermal analyses (TGA/DSC), UV-vis spectra, and ESR for copper(II) decxycholate complex investigations were performed in the structural assignments of Co(II), Ni(II) and Cu(II) decxycholate complexes. Reaction of the sodium deoxycholate ligand (C24H39O4Na) with three transition metal ions form the complexes of formulae, [M(C24H39O4)2(H2O)2] . xH2O where M = Co(II), Ni(II) and Cu(II) where x = 2 for Cu(II) and x = 4 in case of M = Co(II) or Ni(II) metal ions. The FTIR spectra of the complexes show that decxycholate molecule is present as bidentate ligand. Molecular docking utilizing to additionally examine the interaction of COVID-19 (6LU7) with different complexes of deoxycholic acid with Co(II), Ni(II) and Cu(II). Furthermore, in the case of Co(II) deoxycholate complex, the probe is surrounded by amino residues Met235, Pro241, Glu240, Pro108, Gln110, Phe294, and Ile152. The probe molecule of Ni(II) deoxycholate complex is sited close to amino acids Tyr126, Tyr239, Leu287, Leu272, and Lys137. For, Cu(II) deoxycholate complex, the residues of amino acids comprise of Pro132, Pro108, Gln110, Gly109, Ile200, Asn203, Val202, His246, Pro293 and Tyr154. The binding energy was determined from the docking reads for Co(II)–6LU7, Ni(II)–6LU7 and Cu(II)–6LU7 deoxycholate compounds were found to be −446.99, −500.52, −398.13 kcal mol−1 individually.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 2; 54-59
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uranium - Doping Effects on Structural and Spectral Features of Vanadate Ceramics
Autorzy:
Elsabawy, Khaled M.
Powiązania:
https://bibliotekanauki.pl/articles/1192708.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
212 Vanadate
Ceramic
ESR
IR
Uranium Doping
X- ray
Opis:
212-Vanadate ceramics with formula Bi2SrV2-xUxO9, where (0 ≤ x ≤ 0.6 mole ) were carefully synthesized by solution routes with sintering temperature at 880oC for 24 hrs. Structural analysis with XRD proved that uranium (IV)-dopant can substitute successfully until x = 0.55 mole on the Bi-layered perovskite crystal structure without damaging the original structure . It was observed that U – doping have slight to moderate effects on both ESR-signals and conduction mechanism of U-doped Bi-Sr-V-O regime. Electrical measurements indicated that the energy gap Eg and number of electrons in conduction band Ncb increase as the ratio of U doping increases from x = 0.05 till x = 0.6 mole respectively due to the increasing of paramagnetic character of uranium than vanadium.
Źródło:
World Scientific News; 2016, 30; 103-116
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Association between estrogen receptor alpha gene polymorphisms and bone mineral density in Polish female patients with Graves disease
Autorzy:
Ignaszak-Szczepaniak, Magdalena
Horst-Sikorska, Wanda
Dytfeld, Joanna
Gowin, Ewelina
Słomski, Ryszard
Stajgis, Marek
Powiązania:
https://bibliotekanauki.pl/articles/1039960.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Graves' disease
bone mineral density
ESR1 gene polymorphisms
premenopausal women
Opis:
Graves' (GD) hyperthyroidism leads to reduced bone mineral density (BMD) accompanied by accelerated bone turnover. Ample studies have identified association between estrogen receptor (ESR1) gene polymorphism and decreased BMD and osteoporosis. In contrast, number of publications that link ESR1, BMD and Graves' disease is limited. The purpose of this study was to identify the association between ESR1 polymorphisms and BMD in premenopausal women with GD and to determine whether ESR1 polymorphic variants can predispose to GD. The study included 75 women aged 23-46 years with GD and 163 healthy controls. BMD was measured at lumbar spine and femoral neck. We investigated two SNPs in the ESR1 gene and analyzed genetic variants in the form of haplotypes reconstructed by statistical method. Three out of four possible haplotypes of the PvuII and XbaI restriction fragment length polymorphisms were found in GD patients: px (55.3 %), PX (33.3 %) and Px (11.4 %). Women homozygous for xx of XbaI and for pp of PvuII had the lowest BMD at lumbar spine. Moreover, the px haplotype predisposed to reduced lumbar BMD. No associations were observed for femoral neck BMD. No statistically significant relationship were found between ESR1 polymorphisms or their haplotypes and GD. These results indicate that the PvuII and the XbaI polymorphisms of ESR1 gene are associated with bone mineral density in premenopausal women with GD and may help to estimate the risk of bone loss particularly at lumbar spine. However, none of the ESR1 gene alleles predict the risk of GD in Polish female patients.
Źródło:
Acta Biochimica Polonica; 2011, 58, 1; 101-109
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of selected amino acids on the dynamic properties of the liposome membranes : ESR study
Autorzy:
Man, D.
Broda, M.
Buczek, A.
Kawecka, A.
Siodłak, D.
Powiązania:
https://bibliotekanauki.pl/articles/146690.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EYL liposomes
electron spin resonance (ESR) method
N-methylation
amino acids
peptides
Opis:
In this work the changes in the fluidity of liposome membranes caused by alanine and butyrine derivatives (Ac-Ala-NMe2 and Ac-Abu-NMe2) were investigated. Liposomes were obtained in the process of egg yolk lecithin (EYL) sonication. The concentration of the admixture in the proportion to EYL varied from 0 to 25% mole. The electron spin resonance (ESR) spectroscopy was used with two different spins probes. Each spin probe penetrates different regions of liposome membrane. The TEMPO probe occurs both in the hydrophobic part of the membrane and in the water environment what allows to determine the spectroscopic parameter F of division of this probe into the membrane and its water surrounding. DOXYL is localized in the central part of the lipid bilayer and is used to obtain the spectroscopic parameter τ – rotation correlation time – whose value gives information about fluidity changes in the middle of the lipid bilayer. The study indicated that the tested as admixtures N-methylated model peptides significantly changed the fluidity of liposome membranes. The dynamic of this process depends both on amino acids derivative and on the membrane region. Both studied compounds increased the fluidity of the surface layer of liposome membrane. At the same time, butyrine derivative caused the stiffening of the middle part of liposome bilayer, but alanine derivative slightly increased the fluidity of this region.
Źródło:
Nukleonika; 2013, 58, 3; 443-446
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical studies of undoped GaP grown by LEC method
Badania optyczne niedomieszkowanych kryształów GaP otrzymywanych metodą LEC
Autorzy:
Surma, B.
Wnuk, A.
Piersa, M.
Strzelecka, S.
Pawłowski, M.
Jurkiewicz-Wegner, E.
Powiązania:
https://bibliotekanauki.pl/articles/192030.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Materiałów Elektronicznych
Tematy:
GaP
fotoluminescencja
defekt samoistny
pomiar Halla
ESR
photoluminescence
native defects
Hall measurements
Opis:
The features of undoped LEC GaP crystals with particular emphasis on their luminescence properties are presented. Hall and GDMS measurements revealed that C and Si are the main residual shallow impurities. Semi-insulating features of the samples were controlled by the presence of the phosphorous anti-site defect, P4PGa. Its presence was confirmed by ESR measurements as well as the emission at 1.05 eV. For p-type samples with phosphorous antisite defect, P4PGa, and high carbon concentration an emission at 1.9 eV has been observed. We tentatively assign this emission to the recombination of the excitons bound with isoelectronic complex PGaCp. A deep-centre luminescence with the maximum at 1.33 eV was dominant in n-type GaP and in electron-irradiated samples. The obtained results indicate that this emission results from native defect complex.
W pracy przedstawione są badania niedomieszkowanych kryształów GaP otrzymywanych w ITME metodą LEC ze szczególnym uwzględnieniem ich własności luminescencyjnych. Pomiary Halla, absorpcyjne i GDMS wykazały, że głównymi płytkimi domieszkami resztkowymi w otrzymywanych kryształach są węgiel i krzem. Półizolujące własności badanych kryształów determinowane były obecnością fosforowego antystrukturalnego defektu P4PGa. Obecność jego została potwierdzona poprzez obecność linii rezonansowej w widmie ESR, jak również poprzez obecność emisji w podczerwieni z maksimum przy l .05 eV. W kryształach typu p, w których potwierdzona została obecność defektu P4PGa oraz stwierdzono relatywnie wysoką koncentrację węgla w widmie luminescencyjnym pojawiło się pasmo luminescencyjne z maksimum przy l .9 eV. Nasza sugestia odnośnie pochodzenia tej emisji wiązana jest z wytworzeniem się isoelektronowego kompleksu PGaCp. W niedomieszkowanych próbkach typu w jak również w próbce naświetlanej elektronami luminescencja pochodząca od głębokich centrów zdominowana była obecnością pasma leżącego przy 1.33 eV. Przeprowadzone badania wykazały, że jest ona związana z obecnością kompleksu wytworzonego przez macierzyste atomy sieci, natomiast nie zależy od koncentracji domieszek resztkowych.
Źródło:
Materiały Elektroniczne; 2009, T. 37, nr 2, 2; 38-46
0209-0058
Pojawia się w:
Materiały Elektroniczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antioxidant properties of wines produced in the Podkarpacie region
Autorzy:
Szterk, A.
Stefaniuk, I.
Cieniek, B.
Kuźma, M.
Powiązania:
https://bibliotekanauki.pl/articles/147112.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron spin resonance (ESR)
POBN spin trap
superoxide radial anion
Polish wines
Opis:
The wine is famous and popular drink having properties of reactive oxygen species scavenging. In this paper we study the antioxidant activity of the selected wines produced in the south-east region of Poland, in Subcarpathian Voivodeship, in the Podkarpacie region. We have concentrated our studies on the superoxide radical anion O2 •–. We have used electron spin resonance spectroscopy (ESR) as it is the best method for radical detection. The nitrone spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) has been used in the experiment. The radical scavenging ability of wines were determined from the changing intensity of the spectrum in time.
Źródło:
Nukleonika; 2013, 58, 3; 447-450
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lipid radicals: Properties and detection by spin trapping.
Autorzy:
Stolze, Klaus
Udilova, Natascha
Nohl, Hans
Powiązania:
https://bibliotekanauki.pl/articles/1044212.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
DEPMPO
spin trapping
linoleic acid hydroperoxide
free radicals
lipid peroxidation
ESR
lipid radicals
Opis:
Unsaturated lipids are rapidly oxidized to toxic products such as lipid hydroperoxides, especially when transition metals such as iron or copper are present. In a Fenton-type reaction Fe2+ converts lipid hydroperoxides to the very short-lived lipid alkoxyl radicals. The reaction was started upon the addition of Fe2+ to an aqueous linoleic acid hydroperoxide (LOOH) emulsion and the spin trap in the absence of oxygen. Even when high concentrations of spin traps were added to the incubation mixture, only secondary radical adducts were detected, probably due to the rapid rearrangement of the primary alkoxyl radicals. With the commercially available nitroso spin trap MNP we observed a slightly immobilized ESR spectrum with only one hydrogen splitting, indicating the trapping of a methinyl fragment of a lipid radical. With DMPO or 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO) adducts were detected with carbon-centered lipid radical, with acyl radical, and with the hydroxyl radical. We also synthesized lipophilic derivatives of the spin trap DEPMPO in order to detect lipid radical species generated in the lipid phase. With all spin traps studied a lipid-derived carbon-centered radical was obtained in the anaerobic incubation system Fe2+/LOOH indicating the trapping of a lipid radical, possibly generated as a secondary reaction product of the primary lipid alkoxyl radical formed. Under aerobic conditions an SOD-insensitive oxygen-centered radical adduct was formed with DEPMPO and its lipophilic derivatives. The observed ESR parameters were similar to those of alkoxyl radical adducts, which were independently synthesized in model experiments using Fe3+-catalyzed nucleophilic addition of methanol or t-butanol to the respective spin trap.
Źródło:
Acta Biochimica Polonica; 2000, 47, 4; 923-930
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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