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    Tytuł:
    Fazy stacjonarne do chromatografii cieczowej z wbudowanymi grupami polarnymi : synteza i właściwości powierzchniowe
    Chemically bonded stationary phases with incorporated polar groups for liquid chromatography : the synthesis and surface properties
    Autorzy:
    Bocian, S.
    Krzemińska, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/171968.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    chromatografia cieczowa
    fazy stacjonarne
    wbudowane grupy polarne
    właściwości powierzchniowe
    procesy solwatacyjne
    liquid chromatography
    stationary phases
    polar embedded stationary phases
    surface properties
    solvation processes
    Opis:
    In recent years high performance liquid chromatography (HPLC) has gained a dominant position in the life sciences. The widespread use of this technique allows to perform an analysis of compounds which are used in various areas of human life. Currently, there are wide and fully untapped opportunities for synthesis of chromatographic packings with chemically bonded stationary phases. Some of the liquid chromatographic analyses needs the application of water-rich mobile phases (more than 85% water or a buffer). In such condition the performance of hydrophobic stationary phases indicate that the bonded ligands might be collapsing. This problem could be solved by increasing of organic content in the mobile phase which should improve solvation and bring bonded ligands back to the original conformation. To avoid this procedure, which reduces the retention and selectivity of the separation, it is possible to apply stationary phases with incorporated polar groups mixed with the original alkyl ligands (polar embedded stationary phases). Another possibility is to add some polar groups during endcapping procedure (polar end-capped stationary phases). This produces variation in the bonding. Chemically bonded stationary phases which include both hydrophobic and hydrophilic ligands are so-called mixed mode stationary pahses. These materials can be used in reversed phase liquid chromatography (RPLC) and there is also a possibility to use them in hydrophilic interaction liquid chromatography (HILIC). They allow to separate polar and non-polar analytes. Following the idea of green chemistry, especially green analytical chemistry, a series of stationary phases was synthesized. The obtained materials connect polar and hydrophobic groups in the structure of bonded ligands. These specific surface properties provide the stability of the stationary phase in pure water as a mobile phase. Surface properties of novel material were analyzed using various instrumental and chromatographic methods. Finaly, the mixtures of various compounds were applied to test the separation selectivity of stationary phases in various chromatographic system, including purely aqueous conditions.
    Źródło:
    Wiadomości Chemiczne; 2018, 72, 9-10; 685-701
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chromatograficzna analiza związków budujących kwasy nukleinowe
    Chromatographic analysis of nucleic acids constituents
    Autorzy:
    Studzińska, S.
    Rola, R.
    Łobodziński, F.
    Krzemińska, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/172180.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    nukleozydy
    nukleotydy
    oligonukleotydy
    chromatografia cieczowa
    czułość
    selektywność
    nucleosides
    nucleotides
    oligonucleotides
    liquid chromatography
    sensitivity
    selectivity
    Opis:
    Understanding the characteristics, role and structure of nucleic acids allowed to answer questions about the disease processes. Today, nucleic acids and their constituents are tools, which are used by molecular biology in medicine and biotechnology. Antisense and gene therapy are intensively developing methods for possible treating or preventing disease. They use short fragments of DNA or RNA - oligonucleotides to silence the genes expression. They are not the only ones that allow analytical chemists to obtain information about the state of our body. Determination of modified nucleoside allows detection of cancer, while analysis of nucleotides allows the estimation of strengthening the immune system. There is a great need of sensitive, selective and precise methods of separation of nucleosides, nucleotides and oligonucleotides and their qualitative and quantitative analysis. Consequently liquid chromatography (LC) is the most commonly used for analysis of nucleic acid constituents. The most widely used modes of LC include Ion Exchange Chromatography (IEC) and Reversed Phase High Performance Liquid Chromatography (RP HPLC). Both techniques have their advantages and disadvantages in the analysis of nucleosides, nucleotides and oligonucleotides. In the case of IEC it is necessary to use high concentrations of the salt in the mobile phase or concentration gradients, which considerably limits the possibility of using MS detection. RP HPLC can be coupled with MS detection but only when volatile salts are mobile phase components. On the other hand there is a significant problem is the lack of sufficient selectivity for the most polar nucleosides and nucleotides. RP HPLC MS is still most often used in the determination of nucleosides and nucleotides, due to its high sensitivity and a comprehensive qualitative analysis. Another system used for the HPLC analysis of oligonucleotides is Ion Pair Reversed Phase High Performance Liquid Chromatography (IP RP HPLC). These compounds can not be analyzed by RP HPLC due to their high polarity. The advantage of IP RP HPLC is selectivity, achieved by a suitable choice of mobile phase composition and the possibility of using MS. A disadvantage of IP RP HPLC in the analysis of oligonucleotides is however lower sensitivity compared to RP HPLC. During the last few years Hydrophilic Interaction Liquid Chromatography (HILIC) was applied for the separation of mixtures of nucleosides, nucleotides, oligonucleotides extracted from a biological or food samples. The presented results demonstrate the usefulness of this method, however, the resolving power is limited due to the asymmetric peak shape. On the other hand proper selection of the mobile and stationary phase can lead to a high selectivity in the analysis of the most polar nucleosides, nucleotides and oligonucleotides, which can not be separated by RP HPLC.
    Źródło:
    Wiadomości Chemiczne; 2016, 70, 9-10; 633-656
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of surface and structural properties on the initial release of risperidone from polymeric drug carriers
    Autorzy:
    Turek, A.
    Kasperczyk, J.
    Jelonek, K.
    Dobrzyński, P.
    Walichiewicz, J.
    Krzemińska, K.
    Smola, A.
    Musiał-Kulik, M.
    Marcinkowski, A.
    Libera, M.
    Gębarowska, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/284323.pdf
    Data publikacji:
    2012
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
    Tematy:
    risperidone
    implantable drug carriers
    poly(L-lactide-co-glycolide)
    poly(DL-lactide-co-glycolide)
    initial release
    Opis:
    In this work, implantable drug formulation with risperidone on the basis of poly(L-lactide-co-glycolide) (L-PLGA) and poly(D,L-lactide-co-glycolide) (D,L-PLGA) as drug carries was developed. The influence of surface and structural properties on the initial release of risperidone during the first twenty four hours was determined. In this aim, high-performance liquid chromatography, nuclear magnetic resonance spectroscopy, scanning electron microscope and atomic force microscope were used. Significant differences between L-PLGA and D,L-PLGA matrices in all analyzed data were noted. The burst effect was not revealed for any of the studied polymers, however the released drug was almost five times larger for D,L-PLGA matrices. The L-PLGA copolymer revealed a significantly longer average length of the lactidyl and glycolidyl blocks than D,L-PLGA. Moreover, various characters of surface for analyzed matrices were shown, i.e. in case of L-PLGA the surface was porous and in case of D,L-PLGA it was nonporous. Undoubtedly, there were dependences between risperidone's initial release and the topography and the structure of polymeric matrices. We suppose that the larger drug release for L-PLGA was more associated with surface properties and thus structure of matrices. The obtained results showed the great potential of both polymers and possibility to choose the optimal polymer.
    Źródło:
    Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 144-146
    1429-7248
    Pojawia się w:
    Engineering of Biomaterials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rola powierzchni i struktury w początkowym uwalnianiu rysperydonu z matryc L-PLGA i D,L-PLGA
    Role of surface and structure in the initial release of risperidone from L-PLGA and D,L-PLGA matrices
    Autorzy:
    Turek, A.
    Kasperczyk, J.
    Jelonek, K.
    Dobrzyński, P.
    Walichiewicz, J.
    Krzemińska, K.
    Smola, A.
    Musiał-Kulik, M.
    Marcinkowski, A.
    Libera, M.
    Gębarowska, K.
    Janeczek, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/284922.pdf
    Data publikacji:
    2013
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
    Tematy:
    rysperydon
    implantacyjne nośniki leków
    poli (L-laktyd-ko-glikolid)
    poli(D,L-laktyd-ko-glikolid)
    początkowe uwalnianie
    risperidone
    implantable drug carriers
    poly(L-lactide-co-glycolide)
    poly(DL-lactide-co-glycolide)
    initial release
    Opis:
    W niniejszej pracy była opracowywana implantacyjna postać leku zawierająca rysperydon wytworzona z poli(L-laktydo-ko-glikolidu) (L-PLGA) oraz poli(D,L- laktydo-ko-glikolidu) (D,L-PLGA) zastosowanych jako nośniki leku. Ustalano wpływ właściwości powierzchniowych i strukturalnych na początkowe uwalnianie rysperydonu podczas pierwszych 24 godzin inkubacji. W tym celu zastosowano wysokosprawną chromatografię cieczową, spektroskopię magnetycznego rezonansu jądrowego, skaningową kalorymetrię różnicową, skaningowy mikroskop elektronowy oraz mikroskop sił atomowych. We wszystkich analizowanych danych zaobserwowano różnice pomiędzy matrycami wykonanymi z L-PLGA, a matrycami sporządzonymi z D,L-PLGA. Nie wykazano efektu wyrzutu dla żadnego z badanych polimerów, jakkolwiek ilość uwolnionego leku w przypadku matryc D,L-PLGA była prawie pięciokrotnie wyższa. Kopolimer L-PLGA charakteryzował się znacząco większą średnią długością blokówlaktydylowych iglikolidylowych niż D,L-PLGA. Co więcej, zaobserwowano inny charakter powierzchni analizowanych matryc, to znaczy w przypadku L-PLGA powierzchnia była porowata, podczas gdy w przypadku D,L-laktydu nie obserwowano perforacji. Niewątpliwie istnieje zależność między początkowym uwalnianiem rysperydonu, a topografią i strukturą matryc polimerowych. Przypuszcza się, że większe uwalnianie leku z L-PLGA było bardziej związane z właściwościami powierzchniowymi niż ze strukturą matryc. Otrzymane wyniki wskazują na ogromny potencjał obu tych polimerów i możliwość wybrania optymalnego materiału.
    In this work, implantable drug formulation with risperidone on the basis of poly(L-lactide-co-glyco- lide) (L-PLGA) and poly(D,L-lactide-co-glycolide) (D,L-PLGA) as drug carries has been developed. The influence of surface and structural properties on the initial release of risperidone during the first 24 hours has been determined. In this aim, high-performance liquid chromatography, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, scanning electron microscope and atomic force mic¬roscope were used. The differences between L-PLGA and D,L-PLGA matrices in all analyzed data were noted. The burst effect was not revealed for any of the studied polymers, however the released drug was almost five times larger for D,L-PLGA matrices. The L-PLGA copolymer revealed a significantly longer average length of the lactidyl and glycolidyl blocks than D,L-PLGA. Moreover, various characters of surface for analyzed matrices were shown, i.e. in the case of L-PLGA the surface was porous and in the case of D,L-PLGA it was nonporous. Undoubtedly, there were dependences between risperidone's initial release and the topography and the structure of polymeric matrices. We suppose that the larger drug release for L-PLGA was more associated with surface properties than with structure of matrices. The obtained results show the great potential of both polymers and possibility to choose the optimal material.
    Źródło:
    Engineering of Biomaterials; 2013, 16, 118; 30-36
    1429-7248
    Pojawia się w:
    Engineering of Biomaterials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-4 z 4

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