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991.
992.
Jiří Plíšek Lenka Kujovská Krčmová Jana Aufartová Tanausú V. Morales Sarah M. Esponda Roman Oros Eva Kasalová Jose J. Santana‐Rodriguez Luboš Sobotka Petr Solich Dagmar Solichová 《Journal of separation science》2013,36(23):3702-3708
Biomarkers, 25‐hydroxyvitamin D3 and 25‐hydroxyvitamin D2, are important indicators of the vitamin D general status and are monitored in several pathophysiological disorders, such as osteoporosis, diabetes, heart disease, etc. A novel ultra‐HPLC with MS/MS methodology for the analysis of 25‐hydroxyvitamin D derivatives coupled with a very simple and highly rapid sample preparation step was developed. Analytical parameters obtained showed linearity (R2) above 0.999 for both vitamins with accuracies between 95.8 and 102%. The LODs were as low as 0.22 and 0.67 nmol/L for 25‐hydroxyvitamin D3 and 25‐hydroxyvitamin D2, respectively. Intra‐assay precision (%RSD) was lower than 4.5%, and inter‐assay precision (%RSD) was lower than 6.5%. The feasibility of the developed methodology to be applied in clinical routine analysis has been proved by its application in blood samples from non‐agenarian patients, patients with familial hypercholesterolemia and patients suffering from age‐related macular degeneration. 相似文献
993.
Dick Pluim Bart A. W. Jacobs Martin D. Krähenbühl Anna E. M. Ruijter Jos H. Beijnen Jan H. M. Schellens 《Analytical and bioanalytical chemistry》2013,405(7):2391-2395
Pharmacodynamic (PD) analysis requires accurate and precise quantification of enzyme activity targeted by anticancer agents in surrogate cells like peripheral blood mononuclear cells (PBMCs). Enzyme activity is normally reported per mass unit of protein input. However, high and fluctuating hemoglobin (Hb) contamination strongly influences the protein content of PBMC cytosolic lysate. We present the development and validation of a spectrophotometrical Hb quantification method to correct for this contamination. The applicability of Hb correction was demonstrated by determination of the dihydropyrimidine dehydrogenase enzyme activity in PBMC cytosolic lysates. 相似文献
994.
Król Mariusz Staszuk Marcin Mikuszewski Tomasz Kuc Dariusz 《Journal of Thermal Analysis and Calorimetry》2018,134(1):333-341
Journal of Thermal Analysis and Calorimetry - The effect of 2 mass% rare earth elements (RE) as in mischmetal state on the structure, thermal behaviour and mechanical properties of... 相似文献
995.
AbstractWe show that a gauge bounded Cartier algebra has finite complexity. We also give an example showing that the converse does not hold in general.Communicated by Graham J. Leuschke 相似文献
996.
997.
Holger Poths Erik Wischerhoff Rudolf Zentel Axel Schönfeld Guido Henn Friedrich Kremer 《Liquid crystals》2013,40(5):811-818
Abstract Two new ferroelectric oligosiloxanes, a cyclic tetramer and a twin, have been synthesized. By a comparative study with their corresponding monomer and side chain polysiloxanes, the influence of oligo- and polymerization on the liquid crystalline and ferroelectric properties have been investigated. Polymerization leads to a stabilization of LC phases through increase of the clearing temperatures and suppression of crystallization. Oligomerization also leads to mesophase broadening, but, due to the low degree of polymerization, the effect is inferior to the linear polysiloxanes. The low viscosity of the oligosiloxanes ensures response times in the microsecond region, thus being comparable with their monomer and conventional LMWFLCs. It is found that polymerization increases the spontaneous polarization P s. This is attributed to the density increase after polymerization, enhancing the inter-mesogenic interactions. The collective and local dynamics of the OFLCs are influenced differently with respect to their molecular structures. Each oligomer is already a good model for its corresponding polymer concerning the soft mode dynamics. For the local β-relaxation a similar temperature dependence of the relaxation times τ for the cyclic tetramer and for the side chain polysiloxanes is observed. The long axial rotation of the twin, having a very efficient decoupling, is significantly faster, thus resembling the monomer. 相似文献
998.
The synthesis of three aza-analogues of benzothiazole derivatives possessing calcium antagonistic properties has been achieved. 相似文献
999.
1000.
Janna Geith Thomas M. Klaptke Peter Mayer Axel Schulz Jan J. Weigand 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(9):o545-o547
In the title compound, C5H6N2O4, the molecules lie across a crystallographic mirror plane. The compound lacks traditional hydrogen‐bond donors, and hence crystals are held together by unusual C=O⋯O, O⋯C and weak C—H⋯O interactions, forming layers. Adjacent layers are arranged in an antiparallel manner, yielding an ABA layer sequence. The intermolecular contacts are quite short; a topological analysis of charge density based on density‐functional‐theory calculations was used for consideration of these short contacts and indicated a strong attractive bonding closed‐shell interaction between these atoms in the crystal structure. 相似文献