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81.
Calorimetry is evaluated for study of the toxic effect of environmental androgens on Schizosaccharomyces pombe cells. The results indicate that androstendione, androstandiendione and dehydrotestosterone inhibited S. pombe heat production rate. Although, the turbidimetric method showed that testosterone (TS) had no influence on growth of S. pombe, calorimetry revealed that there was a shift in growth period in samples with TS. 相似文献
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Krzysztof Idzik Jadwiga Sołoducho Joanna Cabaj Mariusz Mosiądz Mieczysław Łapkowski Sylwia Golba 《Helvetica chimica acta》2008,91(4):618-627
The substituted monomers 4a , c , d, 5a , b, 6a, 7a , b , and 8a of novel poly(diphenylamines), possessing the respective photochromic groups, were synthesized by the Stille cross‐coupling methodology (Scheme). The hyperbranched structures were characterized by 1H‐ and 13C‐NMR spectroscopy. The obtained monomers show good stability in common organic solvents such as CHCl3, toluene, and CH2Cl2, and exhibit excellent thermal stability. Electrochemical results and theoretical calculations suggest that oxidation and reduction of the monomers start from the side of the amine function and the five‐membered heterocyclic ring moieties, respectively. 相似文献
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Magorzata Szczesio Andrzej Olczak Katarzyna Gobis Ida Mazerant Sylwia Kauyska Henryk Foks Marek L. Gwka 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(1):75-79
The emergence of drug‐resistant strains of Mycobacterium tuberculosis has intensified efforts to identify new lead tuberculostatics. Our earlier studies concluded that the planarity of a molecule correlates well with its tuberculostatic activity. According to our hypothesis, only derivatives whose molecules are capable of adopting a planar conformation may show tuberculostatic activity. The structures of three new potentially tuberculostatic compounds, namely N′‐[bis(methylsulfanyl)methylidene]‐N‐methyl‐4‐nitrobenzohydrazide (denoted G1), C11H13N3O3S2, N′‐[bis(benzylsulfanyl)methylidene]‐N‐methyl‐4‐nitrobenzohydrazide (denoted G2), C23H21N3O3S2, and N′‐[(benzylsulfanyl)(methylsulfanyl)methylidene]‐4‐nitrobenzohydrazide (denoted G3), C16H15N3O3S2, were determined by X‐ray diffraction. The significant distortion from planarity caused by the methyl substituent at the N atom of the hydrazide group or the NO2 substituent in the aromatic ring leads to the loss of tuberculostatic activity for G1, G2 and G4 {systematic name: N′‐[bis(methylsulfanyl)methylidene]‐2‐nitrobenzohydrazide}. A similar effect is observed when there are large substituents at the S atoms (G2 and G3). 相似文献
84.
Natalia Festinger Sylwia Smarzewska Valentin Mirčeski Witold Ciesielski 《Electroanalysis》2021,33(2):314-322
In this study, a simple and sensitive square wave voltammetric procedure has been developed for the determination of acemetacin (ACM) at graphite flake paste electrode (GFPE) and glassy carbon electrode (GCE). Under optimized conditions, the dependence of ACM peak current on its concentration showed wide linear range: 0.03–1.0 μmol L−1 and 0.7–15.0 μmol L−1 at GFPE and GCE, respectively. The developed method was successfully applied for the determination of ACM in pharmaceuticals and spiked urine with satisfying recoveries. The electrochemical oxidation of ACM is an irreversible process controlled by mixed nature of the mass transfer process. 相似文献
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Natalia Festinger Adrianna Lemiesz Ewelina Skowron Sylwia Smarzewska Witold Ciesielski 《Electroanalysis》2021,33(4):854-863
A sensitive square-wave voltammetry (SWV) method based on basal-plane pyrolytic graphite electrode (BPPGE) and edge-plane pyrolytic graphite electrode (EPPGE) was developed to determine the concentration of the pesticide mandipropamid (MAN) in spiked river water and grape juice samples. Under optimal experimental conditions, the SWV response of EPPGE and BPPGE was linear over the concentration ranges of 0.7 to 9.0 μmol L−1 and 0.5 to 10.0 μmol L−1, respectively. The method was successfully used to determine MAN in spiked samples with good recovery. Cyclic voltammetry (CV) was conducted to understand the mechanism underlying the electrode process of MAN. 相似文献
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87.
The lowest spectral gap of segments of a periodic waveguide in is proportional to the square of the inverse length.
Dedicated to Pavel Exner on the occasion of his 60th birthday. 相似文献
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Irena Baranowska Sylwia Magiera Jacek Baranowski 《Central European Journal of Chemistry》2011,9(6):972-981
The aim of this paper is to optimize and validate a high performance liquid chromatography (HPLC) method for separation and
quantification of five isoflavones. A statistical central composite design was used to separate all peaks. These multivariate
procedures were efficient in determining the optimal separation condition using resolution, capacity factor, asymmetry and
number of theoretical plates.
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