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Tytuł:
On the analysis of a mathematical model of CAR-T cell therapy for glioblastoma: Insights from a mathematical model
Autorzy:
Bodnar, Marek
Foryś, Urszula
Piotrowska, Monika J.
Bodzioch, Mariusz
Romero-Rosales, Jose A.
Belmonte-Beitia, Juan
Powiązania:
https://bibliotekanauki.pl/articles/24200684.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
glioblastoma
CAR-T cell therapy
mathematical modelling
periodic treatment
glejak wielopostaciowy
terapia CAR-T
modelowanie matematyczne
Opis:
Chimeric antigen receptor T (CAR-T) cell therapy has been proven to be successful against different leukaemias and lymphomas. Its success has led, in recent years, to its use being tested for different solid tumours, including glioblastoma, a type of primary brain tumour, characterised by aggressiveness and recurrence. This paper presents an analytical study of a mathematical model describing the competition of CAR-T and glioblastoma tumour cells, taking into account their immunosuppressive capacity. The model is formulated in a general way, and its basic properties are investigated. However, most of the analysis considers the model with exponential tumour growth, assuming this growth type for simplicity. The existence and stability of steady states are studied, and the subsequent focus is on two different types of treatment: constant and periodic. Finally, protocols for CAR-T cell therapy of glioblastoma are numerically derived; these are aimed at preventing the tumour from reaching a critical size and at prolonging the patients’ survival time as much as possible. The analytical and numerical results provide theoretical support for the treatment of glioblastoma using CAR-T cells.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2023, 33, 3; 379--394
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of social media in building awareness of body
Autorzy:
Rowiecka, Jacqueline A
Piotrowska, Joanna
Dziuba, Szymon T.
Rowiecki, Kacper
Powiązania:
https://bibliotekanauki.pl/articles/23944776.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
body image
self-discrepancy theory
social media
wizerunek
media społecznościowe
psychologia społeczna
Opis:
The culture of the modern world assigns a huge importance to the beauty of the external body, treating attractive appearance as a determinant of success and happiness. Physiological changes taking place in the body of a young person correlate with changes in the perception of his body. The article aims to define the role of social media in influencing the perception of the body by adolescents aged 16- 19. The survey questionnaire was used as a quantitative research technique created by the authors and the Sylwetek test (DRS, Contour Drawing Rating Scale). 190 teenagers were included in the study. The conclusion to be drawn from the conducted empirical study is that social media are an important factor in creating a vision of one's own body among maturing people. The statistical analysis of the test results showed a statistically significant discrepancy between the ideal self and the real self in the body image among the examined group of young adolescents.
Źródło:
System Safety : Human - Technical Facility - Environment; 2022, 4, 1; 186-195
2657-5450
Pojawia się w:
System Safety : Human - Technical Facility - Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inequalities in breast cancer incidence and stage distribution between urban and rural female population in Swietokrzyskie Province, Poland
Autorzy:
Paszko, A.
Krzyżak, M.J.
Charkiewicz, A.E.
Ziembicka, D.
Żendzian-Piotrowska, M.
Szpak, A.S.
Florek-Łuszczki, M.
Maślach, D.
Powiązania:
https://bibliotekanauki.pl/articles/2082946.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
breast cancer
incidence
inequalities in health
urban and rural population
stage distribution
Opis:
Introduction and objective. One of the main factors determining the burden of breast cancer is the effectiveness of measures taken to combat this cancer including urban-rural differences. The aim of the study was to analyse the differences in breast cancer incidence and disease stage distribution among urban and rural women in the Świętokrzyskie Province as a part of a strategy for breast cancer control. Materials and method. The study of disease stage distribution included 483 female residents of Świętokrzyskie Province who were diagnosed in 2013 with invasive breast cancer, and reported to Świętokrzyskie Office for Cancer Registration. Urban-rural differences in breast cancer incidence in 2002–2013 were presented using Range Ratio (RR). Changes in incidence trends in urban and rural areas were analysed using joinpoint models. Annual Percentage Change (APC) of the rates was calculated for each time trend. Results. Breast cancer incidence rate in the urban female population was higher than in rural women with RR, amounting to 1.43. However, the analysis of trends showed that the pace and direction of change were developing negatively among inhabitants of rural areas. In 2002–2013, in rural women, the age-standardized rate (ASR) values increased by 2.8% per year (p<0.05). The course of ASR trends showed statistically significant urban-rural differences (p=0.004). Analysis of urban-rural differences in disease stage distribution revealed a non-significantly higher proportion of cases with localised stage in urban than in rural areas, amounting to 51.0% and 43.9%, respectively. Conclusions. Existing health inequalities indicate the need to intensify activities in rural areas and should be the starting point for making key decisions in combating breast cancer.
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 1; 169-164
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytochemical screening of Pulsatilla species and investigation of their biological activities
Autorzy:
Laska, G.
Sienkiewicz, A.
Stocki, M.
Zjawiony, J.K.
Sharma, V.
Bajguz, A.
Piotrowska-Niczyporuk, A.
Jacob, M.
Khan, S.
Powiązania:
https://bibliotekanauki.pl/articles/56981.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The present study aimed to identify biologically active secondary metabolites from the rare plant species, Pulsatilla patens subsp. patens and the cultivated P. vulgaris subsp. vulgaris. Chromatographic fractionation of the ethanolic extract of the roots of P. patens subsp. patens resulted in the isolation of two oleanane-type glycosides identified as hederagenin 3-O-β-d-glucopyranoside (2.7 mg) and hederagenin 3-O-β-d-galactopyranosyl-(1→2)-β-d-glucopyranoside (3.3 mg, patensin). HPLC analysis of the methanolic extract of the crude root of P. patens subsp. patens and P. vulgaris subsp. vulgaris revealed the presence of Pulsatilla saponin D (hederagenin 3-O-α-l-rhamnopyranosyl(1→2)-[β-d-glucopyranosyl(1→4)]-α-l-arabinopyranoside). Chromatographic analysis using GC-MS of the silylated methanolic extracts from the leaves and roots of these species identified the presence of carboxylic acids, such as benzoic, caffeic, malic, and succinic acids. The extracts from Pulsatilla species were tested for their antifungal, antimicrobial, and antimalarial activities, and cytotoxicity to mammalian cell lines. Both P. patens subsp. patens and P. vulgaris subsp. vulgaris were active against the fungus Candida glabrata with the half-maximal inhibitory concentration (IC₅₀) values of 9.37 μg/mL and 11 μg/mL, respectively. The IC₅₀ values for cytotoxicity evaluation were in the range of 32–38 μg/mL for P. patens subsp. patens and 35–57 μg/mL for P. vulgaris subsp. vulgaris for each cell line, indicating general cytotoxic activity throughout the panel of evaluated cancer and noncancer cells.
Źródło:
Acta Societatis Botanicorum Poloniae; 2019, 88, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toxoplasma gondii infection in selected species of free-living animals in Poland
Autorzy:
Sroka, J.
Karamon, J.
Wójcik-Fatla, A.
Dutkiewicz, J.
Bilska-Zając, E.
Zając, V.
Piotrowska, W.
Cencek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2085130.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
Polska
Toxoplasma gondii
nested PCR
genotyping
free-living animals
Opis:
Introduction and objective. Free-living animals can play an important role as a reservoir of Toxoplasma gondi;, however, data concerning this issue in Poland are still limited.The aim of study was to assess the occurrence of T. gondii infection by using molecular methods in free-living animals in selected regions of Poland. Materials and method. Tissues samples of 396 animals (foxes, muskrats, birds, martens, badgers, polecats, raccoons, minks, raccoon dogs, otters, small rodents and insectivores, and grass snakes were collected from various regions of Poland. After samples digestion, DNA was isolated using QIAmp DNA Mini Kit (Qiagen). DNA extraction from small rodents and insectivores samples was performed without digestion. Next, nested PCR (B1 gene) and, for a part of nested PCR positive amplicons, RFLP PCR, were performed according to the method by Grigg and Boothroyd (2001). The other part of nested PCR positive DNA isolates were genotyped using 5 genetic markers: SAG1, SAG2 (5’- and 3’), SAG3, BTUB and GRA6, based on the method by Dubey et al. (2006). These PCR products were sequenced and compared with the NCBI database using Blast. Results. In total, in 50 of the 396 examined animals DNA of T. gondii was detected (12.6%). The highest percentages of positive results in PCR was obtained in martens (40.9%) and badgers (38.5%), lower in birds (27.3%) and the lowest in foxes (7.4%). The RFLP and multilocus PCR analysis showed the dominance of T. gondii clonal type II (or II/III). Conclusions. The results of this study indicate the frequent T. gondii infection among free-living animals in Poland, especially martens and badgers, which may indirectly indicate that these animals contribute to the spread of the parasite in the sylvatic environment in Poland. The genotyping analysis showed the dominance of T. gondii clonal type II (or II/III).
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 4; 656-660
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Fraxinus pollen seasons and forecast models based on meteorological factors
Autorzy:
Kubik-Komar, A.
Piotrowska-Weryszko, K.
Weryszko-Chmielewska, E.
Kaszewski, B.M.
Powiązania:
https://bibliotekanauki.pl/articles/2081720.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
allergy
regression analysis
aerobiology
airborne pollen
Fraxinus
Opis:
Introduction and objective. The timings of Fraxinus and Betula flowering and pollen release overlap, which may cause increased allergic reactions in sensitive people. The aim of the present study was to characterize Fraxinus pollen seasons in Lublin (central-eastern Poland) and to identify meteorological factors that most determine the occurrence of airborne pollen of this taxon, as well as obtain forecast models for the basic characteristics of the pollen season. Materials and method. The study was conducted in Lublin during the period 2001–2016, employing the volumetric method. The seasons were compared by PCA (Principal Component Analysis). To determine relationships between meteorological conditions and the pattern of pollen seasons, regression analysis was used. Data for the period 2001–2015 were used to create forecast models by applying regression analysis, while the 2016 data served to verify these models. Results. Season end date and seasonal peak date were characterized by the lowest variation. The biggest differences were found for peak value and total annual pollen sum. The average dates of occurrence of ash pollen grains in the air of Lublin were between 13 April 13 – 3 May 3, whereas, on average, the pollen peak date occurred on 23 April. The factor loading values for the PC1 variable indicate that it is most strongly correlated with peak value and total pollen sum, while the PC2 variable correlated with the pollen season start date and season duration (a negative correlation). Regression models were developed for the following pollen season characteristics: season start, end and duration, seasonal peak date, and total annual pollen sum. Conclusions. The fit of the forecast models was at the level of 62–94%. Analysis of the data showed that weather conditions mainly in February were important factors controlling the Fraxinus pollen season.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 2; 285-291
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemizm wód neogeńskiego piętra wodonośnego w rejonie Wrocławia
The chemistry of the Neogene multiaquifer formation in the Wrocław region
Autorzy:
Korwin-Piotrowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2075794.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
jakość wód podziemnych
neogeńskie piętra wodonośne
Wrocław
groundwater quality
Neogene multiaquifer
Wroclaw
Opis:
The article presents the chemistry of the Neogene multi-aquifer formation in the Wroclaw region. The principal scope of this study was to present the quality of Neogene groundwater samples collected at the same time from 23 boreholes. Chemical analyses were made at the Central Chemical Laboratory of the Polish Geological Institute - National Research Institute in Warsaw. The Neogene aquifer occurs at significant depths (approximately 80 m b.s.l.), which has a great impact on the groundwater quality. The mineralization of the Neogene multi-aquifer formation was measured and shown as the electrical conductivity (EC). The pH varies from poorly alkaline to alkaline. The research results show the major ions and the hydrochemical type of the groundwater, and they can be a valuable source of information for such domains of human activity as geology, and town and municipal planning.
Źródło:
Przegląd Geologiczny; 2018, 66, 1; 28--37
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geofizyczne rozpoznanie zasięgu kry jurajskiej w Gołaszynie k. Łukowa
Geophysical investigation of spatial distribution of the Jurassic raft in Gołaszyn near Łuków, E Poland
Autorzy:
Mendecki, M.
Świder, M.
Nowaczyńska, I.
Mamak, A.
Odrobińska, J.
Piotrowska, P.
Rewers, J.
Tymińska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2075797.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
kra jurajska
czarny muł
rezystywność elektryczna
Łuków
Gołaszyn
rezerwat przyrody
Jurassic raft
black silt
electrical resistivity imaging
Kra Jurajska nature reserve
Opis:
The paper deals with the study of the Middle Jurassic clays near the town of Łuków, to identify its position, depth and thickness defined using geoelectrical techniques. The electrical properties of the ground were determined by a non-invasive 2D Resistivity Imaging Method which involves the investigation of the distribution of resistivity in the ground in X and Z direction. The measurements were carried out on four survey profiles that allowed to distinguish the horizontal and vertical extent of the Jurassic raft. It is not regular, but represents a more complicated structure. The values of resistivity, identified with the Jurassic clays, were very low and reached about 1-20 Q,m, which allowed interpreting, on each resistivity cross-section, its thickness changing from a few metres up to tens of metres.
Źródło:
Przegląd Geologiczny; 2018, 66, 1; 48--54
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Innovativeness of Ukrainian entreprises
Autorzy:
Piotrowska-Piątek, A.
Matskevych, Y.
Powiązania:
https://bibliotekanauki.pl/articles/321054.pdf
Data publikacji:
2018
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
innovativeness
innovation survey
Ukrainian enterprise
economy
Ukraine
innowacyjność
badanie innowacji
przedsiębiorstwo ukraińskie
gospodarka
Ukraina
Opis:
The article regards the issue of innovative activity of enterprises in the Ukraine. The basis for presented consideration is mainly the overview of the literature and desk research analysis on the basis of the data of Ukrainian Statistics for 2014-2016. The article presents data regarding the innovative activity of entrepreneurs, type of innovation, diversity of activity depending on the size of the enterprise, type of business activity, location, as well as the funding of the innovative activity and cooperation in introducing innovative activities. The data analysis reveals similar dependencies in Ukraine as in other European countries: the scale of innovative activities significantly depends on the size of the enterprise, there is a big differentiation of innovation activity from business type and spatial diversifications.
Źródło:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska; 2018, 118; 469-480
1641-3466
Pojawia się w:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Krytyczne stężenie micelarne i metody jego wyznaczania
Critical micellar concentration and methods of its determination
Autorzy:
Piotrowska-Kirschling, A.
Drzeżdżon, J.
Chmurzyński, L.
Jacewicz, D.
Powiązania:
https://bibliotekanauki.pl/articles/172267.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
związki powierzchniowo czynne
surfaktanty
krytyczne stężenie micelarne
micele
surface active compounds
surfactants
critical micellar concentration
micelles
Opis:
Surfactants are substances, which have surface activity in aqueous solutions [1–3]. By adsorbing on the surface (boundary of phase separation) of the system, they change the surfactant properties of the liquid. Surfactants consist of a hydrophobic part (non-polar, called “tail”) and a hydrophilic part (polar, called “head”) [1–3]. The overall structure of the surfactant molecule is shown in Figure 1. In aqueous solution after exceeding one critical micellar concentration of the CMC surfatant (Critical Micelle Concentration), the surfactant molecules aggregate to form micelles [1–5]. Knowledge of CMC values and the micelle formation in solution, it determines the properties of surfactants and their subsequent use in the chemical industry. Surfactants are used in the chemical industry, inter alia, for the production of many detergents, cosmetics, paints, dyes, agrochemicals, pharmaceuticals, food or oil [2, 3].
Źródło:
Wiadomości Chemiczne; 2018, 72, 11-12; 815-828
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Socio-economic inequalities in the use of dental care in urban and rural areas in Poland
Autorzy:
Piotrowska, D.E.
Pędziński, B.
Jankowska, D.
Huzarska, D.
Charkiewicz, A.E.
Szpak, A.S.
Powiązania:
https://bibliotekanauki.pl/articles/2081767.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
dental public health
rural/urban environment
health disparities
health inequalities
socio-economic factors
Opis:
Introduction. The issue of inequalities in the use of health services and health inequalities between urban and rural dwellers is a subject of numerous scientific reports, but similar publications on dental health are scarce. Objective. The aim of this study is to assess the correlations between the use or non-use of dental services and the classical socio-economic factors (SES) in urban and rural groups in a representative population of Poland. Materials and method. The analysis consisted in desk research based on a questionnaire survey conducted by the Central Statistical Office of Poland on 12,532 individuals (urban areas – 6411, rural areas – 6121) in 2013. The chi-squared test, multivariate and univariate logistic regression models were applied. Results. There were major differences in the use of dental services depending on income level, education and source of income among rural and urban populations, as well as differences between these populations. Urban dwellers had 1.34 times greater odds of using dental services than rural ones (95% CI: 1.20–1.51). In the case of the highest income group, the odds were 3.26 (95% CI 2.21–4.83) times greater in cities and 2.07 (95% CI 1.51–2.85) times greater in villages than the odds in the lowest income group. In the highest education group, the odds were 1.58 (95% CI 1.17–2.13) times greater in urban areas and 2.08 (95% CI 1.48–2.91) times greater in rural areas than the odds in the lowest education group. Conclusions. There are considerable inequalities in the use of dental services, yet the differences in non-use, despite such a need, are less evident. This could imply that health disparities arise not only from economic constraints and unavailability of health care, but also from health attitudes and behaviours.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 3; 512-516
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of heavy physical effort on proteolytic adaptations in skeletal and heart muscle and aorta in rats
Autorzy:
Gilbert-Matusiak, A.
Wyczalkowska-Tomasik, A.
Zendzian-Piotrowska, M.
Czrkowska-Paczek, B.
Powiązania:
https://bibliotekanauki.pl/articles/2081959.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
physical effort
proteolytic enzymes
tissue remodeling
Opis:
Physical effort can elicit differential adaptive changes in the tissues of trained versus untrained rats. Proteolytic activity in the extracellular matrix could be engaged in such adaptation due to its influence on the elasticity of tissues. The effects were investigated of a single physical effort on the activity of elastase, cathepsin K, and plasmin in the skeletal muscles, heart muscles, and aortas of untrained (UT, n=30) and trained (T, n=30) rats. T rats underwent 6 weeks of endurance training. After the last training session, T and UT rats were divided randomly into 3 subgroups. Ten rats from each group (Tpre, n=10) and (UTpre, n=10) were sacrificed. The other 20 rats from each group performed 60 min. of aerobic exercise and were sacrificed immediately post exercise (T0h, n=10; UT0h, n=10) or 3h later (T3h, n=10; UT3h, n=10). Enzyme activity was measured fluorometrically. Cathepsin K and plasmin activity increased in the soleus muscles of UT0h versus UTpre, plasmin activity increased also in UT3h versus UTpre. Elastase, cathepsin K and plasmin activity increased in the heart muscles of T0h and T3h versus Tpre. No aortic differences were observed. Thus, a single bout of physical effort elicited different responses in tissues of T versus UT rats. Increased proteolytic enzyme levels in muscles could influence tissue remodeling. Unchanged aortic cathepsin K levels may help prevent aortic remodeling and neointima formation.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 4; 605-609
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane właściwości fizykochemiczne polikarboksylanowych związków kompleksowych kobaltu(II), niklu(II), miedzi(II) i oksowanadu(IV)
Selected physicochemical properties of polycarboxylate cobalt(II), nickel(II), copper(II) and oxidovanadium(IV) complex compounds
Autorzy:
Piotrowska-Kirschling, A.
Drzeżdżon, J.
Chmurzyński, L.
Jacewicz, D.
Powiązania:
https://bibliotekanauki.pl/articles/171735.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
polikarboksylanowe związki kompleksowe
kinetyka
metoda stopped-flow
właściwości antyoksydacyjne
woltamperometria cykliczna
polycarboxylate complexes
kinetics
stopped-flow method
antioxidant activity
cyclic voltammetry
Opis:
Cobalt(II), nickel(II), copper(II) and oxidovanadium(IV) cations are coordination centers in many polycarboxylate complexes [1‒16]. A number of coordination compounds of transition metal ions with such ligands as polycarboxylate anions and heterocyclic organic ligands, e.g. 1,10-phenanthroline (phen) or 2,2’-bipyridine (bipy) have been examined for their biological properties [3‒16]. Their selected structures and physicochemical properties have been described in the first chapter. The polycarboxylate coordination compounds of cobalt(II), nickel(II), copper(II) and oxidovanadium(IV) have interesting antioxidant, antibacterial and antifungal activities. The antioxidant properties of polycarboxylate complexes of Co(II), Ni(II), Cu(II) and VO(IV) with 4-picoline, 1,10-phenanhroline and 2,2’-bipyridine have been investigated towards the superoxide anion radical using the nitro blue tetrazolium chloride (NBT) test and the cyclic voltammetry (CV). Their antibacterial and antifungal activities have been tested against bacteria and fungus strains that are antagonistic to the human. The determined biological properties of the oxydiacetate Co(II), Ni(II), VO(IV) complexes with bipy/phen, the thiodiacetate VO(IV) and the iminodiacetate Cu(II) complexes have been compared with these of L-ascorbic acid, which is chemical compounds commonly used as the reference antioxidant substance. Consequently, the comparison of antioxidant properties of selected cobalt( II), nickel(II), copper(II) and oxidovanadium(IV) polycarboxylate compounds is described in this work (Section 3, Tab. 1‒4). The kinetics of substitution reactions of selected copper(II) polycarboxylate complex compounds were monitored using the stopped-flow method in various reaction conditions (concentration of complex, temperature, solvent) (Rys. 5‒6) [5, 6]. The obtained results of the kinetic studies of the substitution reactions of [Cu(tda)]n with 2,2’-bipyridine in aqueous surfactants solvents: sodium dodecyl sulfate (SDSaq) and hexadecyl trimethyl- ammonium bromide (CTABaq) at 298.15 K (25 °C) are presented.
Źródło:
Wiadomości Chemiczne; 2018, 72, 11-12; 797-814
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wytwarzanie bazy emulsji kosmetycznych w mieszalnikach mechanicznych typu SEM
Production of cosmetic emulsion base in SEM-type mechanical mixers
Autorzy:
Mitkowski, P. T.
Szaferski, W.
Piotrowska, J.
Mielhorska, A.
Jezierska, M.
Perz, A.
Kuświk, S.
Powiązania:
https://bibliotekanauki.pl/articles/2073313.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
SEM
wytwarzanie emulsji kosmetycznych
SEM-type mixer
preparation of cosmetic emulsions
Opis:
W pracy poddano analizie wpływ liczby sit, przez które wytwarzana była baza emulsji kosmetycznej, na wielkość kropel. Przeanalizowano również układ z pojedynczym sitem, o dwóch różnych wielkościach oczek, pod kątem związku między masowym natężeniem pompy perystaltycznej, a wielkością średnic kropel fazy rozproszonej. Zastosowanie mieszalników typu SEM wpływa korzystnie na właściwości emulsji i pozwoliło uzyskać drobne krople oraz monodyspersyjną emulsję, co jest zjawiskiem pożądanym w przypadku emulsji, które znajdują zastosowanie w kosmetyce.
The influence of number of sieves through which the cosmetic emulsion base was produced on a droplet size was analyzed. The single-sieve system with two different mesh sizes was also analyzed, aiming to find the relationship between mass flow rate of peristaltic pump and droplet diameters of dispersed phase. The use of SEM-type mixers positively influences emulsion properties and enables one to obtain fine droplets and monodisperse emulsion which are advantage features in cosmetic emulsions.
Źródło:
Inżynieria i Aparatura Chemiczna; 2018, 4; 108--109
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza dynamiki skażenia gleby naturalnymi i sztucznymi radionuklidami w województwie opolskim po awarii elektrowni jądrowej w Czarnobylu
An Analysis of The Dynamics of Soil Contamination Density in the Opole Province by Natural and Artificial Radionuclides after the Chernobyl Nuclear Power Plant Accident
Autorzy:
Isajenko, K.
Piotrowska, B.
Stawarz, O.
Łukaszek-Chmielewska, A.
Krawczyńska, S.
Powiązania:
https://bibliotekanauki.pl/articles/373852.pdf
Data publikacji:
2017
Wydawca:
Centrum Naukowo-Badawcze Ochrony Przeciwpożarowej im. Józefa Tuliszkowskiego
Tematy:
awaria reaktora
Czarnobyl
radioaktywność gleby
137Cs
40K
226Ra
228Ac
228Th
województwo opolskie
reactor accident
Chernobyl
soil radioactivity
Opole province
Opis:
Wprowadzenie: W wyniku awarii reaktora elektrowni jądrowej w Czarnobylu na Ukrainie w 1986 roku doszło do niekontrolowanego uwolnienia substancji radioaktywnych. Województwo opolskie należy do obszarów, na których nastąpiła największa kumulacja skażenia powierzchniowego izotopami promieniotwórczymi. Deszczowa pogoda panująca na tym obszarze podczas przechodzenia radioaktywnej chmury wpłynęła na zatrzymanie się w komponentach środowiska różnych izotopów promieniotwórczych. Cel: W opracowaniu skupiono uwagę na przedstawieniu dynamiki zmian wartości stężenia powierzchniowego cezu 137Cs w glebie Opolszczyzny na przestrzeni prawie trzydziestu lat od awarii czarnobylskiej. Projekt i metody: Duże znaczenie dla oceny zmian wartości stężenia powierzchniowego 137Cs w glebie z określonego punktu poboru próbek ma stan mikrośrodowiska. Nie może być ono zniekształcone lub zmienione przez działalność człowieka. Istotne jest również to, aby sposób pobierania próbek był ustalony i powtarzalny, a ich przygotowanie do pomiaru w laboratorium odbywało się według ściśle określonych procedur. Po odpowiednim przygotowaniu próbki są poddawane pomiarom spektrometrycznym na detektorze półprzewodnikowym HPGe oraz analizie promieniowania gamma za pomocą oprogramowania Genie-2000. Wyniki: Podczas analizy widm promieniowania gamma w próbkach gleby stwierdzono obecność naturalnych izotopów 40K, 226Ra i 228Ac oraz sztucznych izotopów 134Cs (rejestrowany do 1996 r.) i 137Cs (rejestrowany do dziś). W artykule przedstawiono rezultaty pomiarów stężeń powierzchniowych 137Cs i stężeń naturalnych radionuklidów 40K, 226Ra i 228Ac w glebie woj. opolskiego dla próbek pochodzących z okresu 1988–2014. Wnioski: Zgodnie z przewidywaniami na przestrzeni prawie 30 lat od awarii w Czarnobylu stężenie 137Cs w glebie stopniowo maleje. Jest to związane z rozpadem izotopu oraz jego przenikaniem w głębsze warstwy gleby. Natomiast stężenie radionuklidów naturalnych w badanych miejscowościach utrzymuje się na podobnym poziomie. Wskazana jest kontynuacja pomiarów, w celu sprawdzenia, jak maleje stężenie powierzchniowe 137Cs w glebie i kiedy jego wartość znajdzie się poniżej progu detekcji. Należałoby także wybrać kilka punktów poboru gleby (także na Opolszczyźnie) w celu zbadania, jak 137Cs przeniknął w głębsze warstwy gleby (pobór z warstwy 25 cm).
In 1986 there was an accident in the reactor at the Chernobyl Nuclear Power Plant in Ukraine which caused an uncontrolled release of radioactive substances. The Opole province in Poland is one of the areas which suffered the greatest accumulation of surface contamination with radionuclides. As a result of rainy weather in this area during the transition of the radioactive cloud, various radioisotopes remained in the environmental components. Objective: The study focuses on the dynamic changes in the surface concentration of cesium 137Cs in soil samples from the Opole province, which have been measured for nearly thirty years since the Chernobyl disaster. Method: The condition of the microenvironment is very important for the assessment of changes in 137Cs surface concentration for the soil taken from the same sampling point, so the microenvironment cannot be distorted or changed by human activity. The method of sampling must be fixed and repeatable, and the preparation of samples for measurement in the laboratory should be conducted according to strict procedures. After proper preparation, samples are measured spectrometrically on a HPGe semiconductor detector and then an analysis of gamma radiation is done with Genie-2000 software. Results: During the gamma-radiation spectrum analysis of the soil samples, the surface concentration of natural isotopes 40K, 226Ra and 228Ac and of artificial isotopes 134Cs (reported till 1996) and 137Cs (reported to the present) was detected. The article presents the results of 137Cs surface concentration measurements, as well as the concentration of 40K, 226Ra and 228Ac natural radionuclides in the soil of the Opole province from samples measured in the period 1988–2014. Conclusions: As expected, for the nearly 30 years since the failure of the Chernobyl NPP, the concentration of 137Cs in the soil has been gradually decreasing as a result of isotope decay and its penetration into the deeper layers of the soil. On the other hand, the concentration of natural radionuclides is at a similar level for the same sampling points. In the future it will be useful to continue measuring to see how the surface concentration of 137Cs for soil is decreasing and when its value will be below the detection threshold. It would be also good to select several sampling points (also in the Opole province) in order to investigate how 137Cs has penetrated into the deeper layers of the soil (a 25-cm layer).
Źródło:
Bezpieczeństwo i Technika Pożarnicza; 2017, 46, 2; 42-54
1895-8443
Pojawia się w:
Bezpieczeństwo i Technika Pożarnicza
Dostawca treści:
Biblioteka Nauki
Artykuł

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