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Wyszukujesz frazę "Gajewska, J." wg kryterium: Autor


Wyświetlanie 1-10 z 10
Tytuł:
Microstructure and microhardness of ball milled/hot pressed aluminium with Mg3N2 addition
Mikrostruktura i mikrotwardość mielonego/prasowanego na gorąco aluminium z dodatkiem Mg3N2
Autorzy:
Gajewska, M.
Dutkiewicz, J.
Morgiel, J.
Powiązania:
https://bibliotekanauki.pl/articles/354744.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium matrix composites
high energy ball milling
magnesium nitride
kompozyty o osnowie z aluminium
wysokoenergetyczny młynek kulowy
azotek magnezu
Opis:
The microstructure and microhardness of a ball milled and hot pressed aluminium powder with 10 vol.% of magnesium nitride (Mg3N2) were investigated. It was expected that the addition of a Mg3N2 as an nitrogen-bearing substrate would allow to obtain an in situ reaction leading to a formation of an aluminium nitride (AlN) strenghtening phase. The powders were milled in a high energy planetary ball mill for up to 40 h and then compacted in vacuum at 400ºC/600 MPa. The material was investigated by means of X-ray diffraction measurements (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and microhardness tests. The performed investigations showed that the composite preparation method provided a significant structure refinement of the material - the average matrix grain size of composite compact was about ˜140 nm. Energy Dispersive Spectrometry (EDS) analysis of Al/ Mg3N2 compact combined with X-ray diffraction (XRD) technique indicated a presence of Mg3N2 as well as Mg-Al-O phase, which were probably formed during hot pressing. Microhardness tests showed nearly 40% increase in the hardness of Al/ Mg3N2 composite over the non-reinforced aluminium compact.
W niniejszej pracy przedstawiono wyniki obserwacji mikrostruktury i pomiarów mikrotwardości kompozytu o osnowie z aluminium z dodatkiem 10% objętościowych azotku magnezu wytworzonego drogą wysokoenergetycznego mielenia połączonego z prasowaniem na gorąco. Zakładano, że dodatek Mg3N2 jako substratu azotonosnego pozwoli na uzyskanie reakcji in situ prowadzącej do wytworzenia fazy wzmacniającej w postaci azotku aluminium. Proszki poddano mieleniu w wysokoenergetycznym młynku kulowym przez okres 40. godzin, a następnie sprasowano w próżni pod ciśnieniem 600 MPa w temperaturze 400ºC. Przeprowadzone obserwacje mikrostruktury materiału wykazały, że zastosowana metoda wytwarzania kompozytu pozwala na uzyskanie znacznego rozdrobnienia struktury materiału - średnia wielkość ziaren osnowy wynosiła ˜140 nm. Pomiary składu chemicznego technika EDS w połączeniu z analizą XRD wskazały na obecność zarówno azotku magnezu, jak również fazy Mg-Al-O w wyprasce kompozytowej. Pomiary mikrotwardości wykazały natomiast 40%-owy wzrost twardości kompozytu Al/ Mg3N2 w porównaniu z wypraska z niezbrojonego aluminium.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 2; 433-436
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trunked Radio Solutions for Special Applications
Autorzy:
Gajewski, S.
Gajewska, M.
Katulski, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/226766.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
LTE
trunked radio
TETRA
DMR
Opis:
In the paper modern concepts of radio communication trunking-dispatch systems for special applications are presented. Basic standards of TETRA, DMR, and cdma2000 are mentioned. The aim of the paper is to present innovative trunking solutions based on the LTE system working both in FDD and TDD mode. The architecture of LTE trunked radio is shown as well as new services possible to implementation are described. The way of TETRA and LTE integration is characterized.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 4; 309-314
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of extracellular matrix and prolactin in functional differentiation of bovine BME-UV1 mammary epithelial cells
Autorzy:
Kozlowski, M.
Wilczak, J.
Motyl, T.
Gajewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/31562.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Interactions between extracellular matrix (ECM) and epithelial cells are necessary for proper organisation and function of the epithelium. In the present study we show that bovine mammary epithelial cell line BME-UV1 cultured on ECM components, commercially available as Matrigel™, constitutes a good model for studying mechanisms controlling functional differentiation of the bovine mammary gland. In contact with Matrigel BME-UV1 cells induce apicobasal polarity, and within 16 days form three dimensional (3D) acinar structures with a centrally localized hollow lumen, which structurally resemble mammary alveoli present in the functionally active mammary gland. We have shown that the 3D culture system enables a high expression and proper localisation of integrin receptors and tight junction proteins in BME-UV1 cells to be induced. This effect was not obtained in cells grown in the classical 2D culture system on plastic. Moreover, ECM highly stimulated the synthesis of one of the major milk proteins, β-casein, even in the absence of prolactin. Our results show that contact with ECM plays an important role in the lactogenic activity of bovine MECs, however, prolactin is necessary for the efficient secretion of milk proteins.
Źródło:
Polish Journal of Veterinary Sciences; 2011, 14, 3
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and Magnetism of LSMO/BTO/MgO/LSMO Multilayers
Autorzy:
Pawlak, J.
Żywczak, A.
Szwachta, G.
Kanak, J.
Gajewska, M.
Przybylski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1030441.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.60.Ej
Opis:
A multiferroic tunnel junction (MFTJ) is a promising device for future memory systems with discrete and different logic states which are controlled by a combination of electric and magnetic fields. The goal of ongoing research is to present ferroelectric and ferromagnetic properties, especially at room temperature (RT), represented as high values of tunnel electroresistance (TER) and tunnel magnetoresistance (TMR). A key aspect is the appropriate preparation of a sample allowing epitaxial growth. The thin layers were prepared by pulsed laser deposition on atomically smooth monocrystalline SrTiO₃ (STO) substrates. The ferromagnetic metal layers La_{0.67}Sr_{0.33}MnO₃ (LSMO) are separated by a layer of a ferroelectric insulator - BaTiO₃ (BTO). The same structure of LSMO, BTO and STO (perovskite) and a similar lattice constant make it possible to obtain high-quality heterostructures. Magnetic measurements confirm differences in the magnetic coercivity of the top and bottom LSMO layer, which allows to obtain their parallel and antiparallel magnetization orientation. A modification of the interfaces of BTO by thin MgO layer enables an increase in the value of the TER effect.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 548-551
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analyses of hospitalization of diabetes mellitus patients in Poland by gender, age and place of residence
Autorzy:
Gajewska, M.
Gebska-Kuczerowska, A.
Gorynski, P.
Wysocki, M.J.
Powiązania:
https://bibliotekanauki.pl/articles/49617.pdf
Data publikacji:
2013
Wydawca:
Instytut Medycyny Wsi
Opis:
Aim. The purpose of this study was to analyze the hospitalization of diabetes mellitus patients in Polish hospitals in 2005-2009. Materials and Methods. Data was taken from a nationwide database, kept at the National Institute of Public Health – National Institute of Hygiene in Warsaw. Data gathered for this work related to patients whose main cause of hospitalization was diabetes. Results. In the period of five years the number of diabetes-caused hospitalizations increased by nearly 22% – from 172.2 per 100 thousand in 2005 to 209.9 per 100 thousand in 2009. Hospital treatment covered mainly patients suffering from type 2 diabetes (116.4 per 100 thousand in 2009), as well as type 1 diabetes (87.6 per 100 thousand in 2009). Patients under 39 years of age were more often hospitalized because of type 1 diabetes, whereas in the older age groups patients were more often treated in hospitals for type 2 diabetes. Generally, in both types of the disease, older patients required hospitalizations more often than the younger ones. Cardiovascular diseases were the most reported co-morbidity in both types of the disease. In 2005-2009 the hospital mortality rate decreased with regard to both types of diabetes and an average length of hospital stay decreased by one day, reaching 8.1 days in 2009. Conclusion. It must be emphasized that the growing epidemic of diabetes and its complications are an important challenge to society. The percentage of people hospitalized due to diabetes is increasing every year and consumes significant resources dedicated to health care. Early diagnosis and appropriate treatment of diabetes are imperative, as well as reducing the disparities in access to medical care (ambulatory and stationary) for town and country residences.
Źródło:
Annals of Agricultural and Environmental Medicine; 2013, 20, 1
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of Two-Dimensional Electron Gas in LPE-Grown GaInAs-InP Heterostructures
Autorzy:
Fronc, K.
Grabecki, G.
Wróbel, J.
Dietl, T.
Gajewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1891365.pdf
Data publikacji:
1991-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Df
73.20.Dx
73.60.Br
Opis:
A series of GaInAs/InP heterostructures was grown by liquid phase epitaxy. The heterostructures were characterized by magnetotransport measurements carried out down to 1.8 K and up 10 T. The results demonstrate the existence of the high-mobility two-dimensional electron gas in the narrow-gap GaInAs as well as the presence of residual conductance through the InP buffer layer.
Źródło:
Acta Physica Polonica A; 1991, 80, 3; 449-452
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interleukin-1beta stimulates early myogenesis of mouse C2C12 myoblasts: the impact on myogenic regulatory factors, extracellular matrix components, IGF binding proteins and protein kinases
Autorzy:
Grabiec, K.
Tokarska, J.
Milewska, M.
Blaszczyk, M.
Gajewska, M.
Grzelkowska-Kowalczyk, K.
Powiązania:
https://bibliotekanauki.pl/articles/30341.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The purpose of the study was to examine the mechanisms important for early myogenesis in mouse C2C12 myogenic cells exposed to interleukin-1β. Cyclin A and cyclin B1 were increased by interleukin-1β (1 ng/ml), but the level of cyclin D1 and total DNA content was unaffected. Fusion index and the rate of protein synthesis was increased in the presence of IL-1β, but these effects were limited to 3-day-treatment. IL-1β increased the level of MyoD, myogenin and MHC on the 3rd day of differentiation, without altering the content of the active form of myostatin, as well as it augmented the level of fibronectin, integrin β1 and full length 100 kDa form of ADAM12. IL-1β caused a decrease in IGFBP-4 and IGFBP-6 levels and a marked increase in IGFBP-5. The phosphorylation of PKB and ERK1/2 and the cellular content of p38 were elevated by IL-1β. We conclude that the myogenic effect of IL-1β was limited to the onset of myoblast fusion and was associated with: i) increase in the level of myogenic transcription factors i.e. MyoD and myogenin expression, ii) modification of extracellular matrix assembly and signaling, manifested by an increase in fibronectin, integrin-β1 and ADAM12 content, iii) drop in IGFBP-4 and IGFBP-6, and an increase in IGFBP-5, that could alter the local IGF-1 bioavailability, and iv) increase in phosphorylation of PKB and ERK1/2, and the expression of p38 kinase, leading to activation of intracellular pathways essential for myogenic differentiation.
Źródło:
Polish Journal of Veterinary Sciences; 2013, 16, 2
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tumor necrosis factor - Alpha alters integrins and metalloprotease ADAM12 levels and signaling in differentiating myoblasts
Autorzy:
Grzelkowska-Kowalczyk, K.
Tokarska, J.
Grabiec, K.
Gajewska, M.
Milewska, M.
Blaszczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/31937.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The extracellular matrix (ECM) is important in the regulation of myogenesis. We hypothesized that tumor necrosis factor-α (TNF-α) modifies ECM during differentiation of mouse C2C12 myoblasts. Exogenous TNF-α (1 ng/ml) stimulated myoblast fusion on the 3rd day (by 160% vs control) but not on the 5th day of myogenesis. The level of integrin α5 was significantly augmented by TNF-α during 5 day-differentiation; however, integrin β1 was higher than control only on the 3rd day of cytokine treatment. Both the abundance of integrin α5 bound to actin and the level of integrin β1 complexed with integrin α5 increased in the presence of TNF-α, especially on the 3rd day of differentiation. Similarly, the stimulatory effects of TNF-α on integrin α3, metalloprotease ADAM12 and kinases related to integrins, FAK and ILK, were limited to the 3rd day of differentiation. We concluded that TNF-α-induced changes in ECM components in differentiating myogenic cells, i.e. i) increased expression of integrin α5, β1, α3, and metalloprotease ADAM12, ii) enhanced formation of α5β1 integrin receptors and interaction of integrin α5-cytoskeleton, and iii) increased expression of kinases associated with integrin signaling, FAK and ILK, were temporarily associated with the onset of myocyte fusion.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 2
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is there the gap in public health literature in Europe?
Autorzy:
Cianciara, D.
Piotrowicz, M.
Gajewska, M.
Urban, E.
Poznanska, A.
Niedzwiedzka, B.
Witkowski, M.
Jarosz, M.J.
Powiązania:
https://bibliotekanauki.pl/articles/51145.pdf
Data publikacji:
2013
Wydawca:
Instytut Medycyny Wsi
Opis:
Introduction and objective: The growing expectations for the effectiveness of public health increase the demand for scientific literature, concerning research, reviews and other forms of information. The bibliographic databases are of crucial importance for researchers and policy makers. The objective of this study is to estimate the supply of scientific literature related to public health in selected European countries, which are available to a wide range of users. Materials and methods: Analysis of the number of bibliographic records on topics related to public health was based on searches in Ovid MEDLINE ( R) in May and June 2011. According to MeSH terms, 11 keywords and names of 13 European countries were used in the search. Publications from the years 2001–2010 were analyzed. A number of publications indexed under ‘public health’, and related to selected countries were compared with the size of the population of those countries, GDP, total expenditure on health and burden of disease (DALYS’s). Results: The most popular topic was ‘health policy’, whereas the topics ‘occupational health’ and ‘environmental health’ were less prevalent. There were no significant changes in the number of publications in 2001–2010. The number of articles indexed under ‘public health’ had significant positive correlation with national GDP, expenditure on health and population size, and negative with DALY’s. Conclusions: According to the criteria accepted in this study, the Nordic countries – Finland, Sweden and Norway – were very productive in this respect. Poland and other Central European Countries were less productive.
Źródło:
Annals of Agricultural and Environmental Medicine; 2013, 20, 3
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlations between organic pollution indicators in municipal wastewater
Korelacje pomiędzy wskaźnikami zanieczyszczeń organicznych w ściekach komunalnych
Autorzy:
Siwiec, T.
Reczek, L.
Michel, M. M.
Gut, B.
Hawer-Strojek, P.
Czajkowska, J.
Jóźwiakowski, K.
Gajewska, M.
Bugajski, P.
Powiązania:
https://bibliotekanauki.pl/articles/205468.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
BOD5
CODCr
TOC
CODMn
wastewater
municipal wastewater treatment plant
BZT5
ścieki
miejska oczyszczalnia ścieków
Opis:
The paper presents the results of a study of parameters used for determining the amount of organic pollutants in wastewater flowing into a collective wastewater treatment plant with a population equivalent of about 120 000 PE. The plant constituted part of a sewage system. Assays were performed for biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), permanganete index (CODMn) and total organic carbon (TOC). In addition, the pH of wastewater and its alkalinity were determined. Sampling of incoming wastewater and measurement of physicochemical parameters were performed once a week, in the spring. A total of 44 samples of wastewater were collected. The correlations between the individual parameters and the correlations between the ratios of these parameters were determined. It was found that it was possible to estimate, with sufficient accuracy, the values of selected parameters for determining the concentrations of organic compounds in municipal wastewater, knowing the values of other parameters in this group. Moreover, it was shown that, knowing the relationship between the analyzed parameters, one can find multiple regression equations for a given type of wastewater, which allow one to calculate the remaining relationships with a good fi t, i.e. a determination factor R2 greater than 0.6.
W pracy przedstawiono wyniki badań parametrów wykorzystywanych do oznaczania ilości zanieczyszczeń organicznych w ściekach wpływających do zbiorczej oczyszczalni ścieków o równoważnej liczbie ludności około 120 000 mieszkańców. Zakład stanowi część systemu kanalizacyjnego. Testy przeprowadzono dla biochemicznego zapotrzebowania na tlen (BZT5), chemicznego zapotrzebowania na tlen (CODCr), utlenialności (CODMn) i ogólnego węgla organicznego (TOC). Ponadto określono wartość pH ścieków i ich zasadowość. Pobieranie próbek dopływających ścieków i pomiar parametrów fizykochemicznych przeprowadzano raz w tygodniu, na wiosnę. Zebrano łącznie 44 próbki ścieków. Określono korelacje między poszczególnymi parametrami i korelacje między stosunkami tych parametrów. Stwierdzono, że możliwe było oszacowanie, z wystarczającą dokładnością, wartości wybranych parametrów do oznaczania stężeń związków organicznych w ściekach komunalnych, znając wartości innych parametrów w tej grupie. Ponadto wykazano, że znając zależność między analizowanymi parametrami, można znaleźć równania regresji wielokrotnej dla danego typu ścieków, które pozwalają obliczyć pozostałe zależności przy dobrym dopasowaniu, o współczynniku determinacji R2 większym niż 0,6.
Źródło:
Archives of Environmental Protection; 2018, 44, 4; 50-57
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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