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71.
Dr. Zhengxing Qin Dr. Georgian Melinte Prof. Jean‐Pierre Gilson Prof. Maguy Jaber Prof. Krassimir Bozhilov Dr. Philippe Boullay Dr. Svetlana Mintova Prof. Ovidiu Ersen Dr. Valentin Valtchev 《Angewandte Chemie (International ed. in English)》2016,55(48):15049-15052
Zeolites are widely used in many commercial processes, mostly as catalysts or adsorbents. Understanding their intimate structure at the nanoscale is the key to control their properties and design the best materials for their ever increasing uses. Herein, we report a new and controllable fluoride treatment for the non‐discriminate extraction of zeolite framework cations. This sheds new light on the sub‐structure of commercially relevant zeolite crystals: they are segmented along defect zones exposing numerous nanometer‐sized crystalline domains, separated by low‐angle boundaries, in what were apparent single‐crystals. The concentration, morphology, and distribution of such domains analyzed by electron tomography indicate that this is a common phenomenon in zeolites, independent of their structure and chemical composition. This is a milestone to better understand their growth mechanism and rationally design superior catalysts and adsorbents. 相似文献
72.
Anna Tashchilova Nadezhda Podoplelova Alexey Sulimov Danil Kutov Ivan Ilin Mikhail Panteleev Khidmet Shikhaliev Svetlana Medvedeva Nadezhda Novichikhina Andrey Potapov Vladimir Sulimov 《Molecules (Basel, Switzerland)》2022,27(4)
In the modern world, complications caused by disorders in the blood coagulation system are found in almost all areas of medicine. Thus, the development of new, more advanced drugs that can prevent pathological conditions without disrupting normal hemostasis is an urgent task. The blood coagulation factor XIIa is one of the most promising therapeutic targets for the development of anticoagulants based on its inhibitors. The initial stage of drug development is directly related to computational methods of searching for a lead compound. In this study, docking followed by quantum chemical calculations was used to search for noncovalent low-molecular-weight factor XIIa inhibitors in a focused library of druglike compounds. As a result of the study, four low-molecular-weight compounds were experimentally confirmed as factor XIIa inhibitors. Selectivity testing revealed that two of the identified factor XIIa inhibitors were selective over the coagulation factors Xa and XIa. 相似文献
73.
Manol Ognyanov Petko Denev Desislava Teneva Yordan Georgiev Sabina Taneva Iskra Totseva Mariana Kamenova-Nacheva Yana Nikolova Svetlana Momchilova 《Molecules (Basel, Switzerland)》2022,27(6)
Gamma irradiation is efficiently applied to many foods, but nevertheless there is a distinct lack of information about the changes of macro- and micronutrients (e.g., carbohydrates, lipids, organic acids, and phenolics) in dried rose hip (RH) fruits. Therefore, in this study, for the first time, the effect of gamma irradiation (10 and 25 kGy) on RH constituents is investigated. Different analytical techniques (GC-FID, HPLC-UV, HPSEC-RID, IR-FT, and SEM) are employed to examine this effect. The irradiation treatment (10 kGy) increased the glucose content by 30% and released cellobiose from RH fruits, thus revealing cellulose destruction. The extractability of total uronic acids increased from 51% (control) to 70.5% (25 kGy-irradiated), resulting in a higher pectin yield (10.8% < 12.8% < 13.4%) and molecular heterogeneity. Moreover, de-esterification was not a major effect of the irradiation-induced degradation of pectin. The sample exposure to the highest dose did not change the content of total carotenoids, β-carotene, and (un)saturated fatty acids, but it affected the tocopherols levels. Gamma rays had a negligible effect on the phenolic constituents and did not affect ORAC and HORAC antioxidant activity. In conclusion, it can be compromised that the exposition of dried RH is safe and can be successfully applied to decontaminate fruits without affecting their nutritional value and biological activity. 相似文献
74.
Rostislav A. Andrievski Svetlana V. Klyuchareva 《Journal of nanoparticle research》2011,13(12):6221-6230
The nanotechnology development is accompanied by an intensive growth of information flow which is specially noticeable as
applied to journal information flow. Now over the world there are the 69 nano-titled journals with the impact factor and/or
a settled periodicity as well as the 70 those which lack stability periodicity and are in an organization stage. Only 49 nano-titled
have the impact factor with the comparatively high mean value of about 3.44. The domestic nano-titled journals published in
Russia, India, China, and other countries are also considered. The attention is taken that in the 2006–2010 period the 95
new nano-titled journals were organized and in 2011 this process is continuing and seems to be the most impressive. Many nano-related
journals (including classical physical, chemical and materials science ones) are also described and discussed. 相似文献
75.
76.
Yury Yu. Rusakov Leonid B. Krivdin Maxim V. Penzik Vladimir A. Potapov Svetlana V. Amosova 《Magnetic resonance in chemistry : MRC》2012,50(10):653-658
Stereochemical structure of nine Z‐2‐(vinylsulfanyl)ethenylselanyl organyl sulfides has been investigated by means of experimental measurements and second‐order polarization propagator approach calculations of their 1H–1H, 13C–1H, and 77Se–1H spin–spin coupling constants together with a theoretical conformational analysis performed at the MP2/6‐311G** level. All nine compounds were shown to adopt the preferable skewed s‐cis conformation of their terminal vinylsulfanyl group, whereas the favorable rotational conformations with respect to the internal rotations around the C–S and C–Se bonds of the internal ethenyl group are both skewed s‐trans. Stereochemical trends of 77Se–1H spin–spin coupling constants originating in the geometry of their coupling pathways and the selenium lone pair effect were rationalized in terms of the natural J‐coupling analysis within the framework of the natural bond orbital approach. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
77.
Bennink RS Wong V Marino AM Aronstein DL Boyd RW Stroud CR Lukishova S Gauthier DJ 《Physical review letters》2002,88(11):113901
We have observed transverse pattern formation leading to highly regular structures in both the near and far fields when a near-resonant laser beam propagates without feedback through an atomic sodium vapor. One example is a regular far-field honeycomb pattern, which results from the transformation of the laser beam within the vapor into a stable three-lobed structure with a uniform phase distribution and highly correlated power fluctuations. The predictions of a theoretical model of the filamentation process are in good agreement with these observations. 相似文献
78.
Solid-Phase Luminescence Determination of Ciprofloxacin and Norfloxacin in Biological Fluids 总被引:1,自引:0,他引:1
Svetlana Beltyukova Olga Teslyuk Alla Egorova Elena Tselik 《Journal of fluorescence》2002,12(2):269-272
A simple, rapid, and sensitive luminescence test method for the determination of ciprofloxacin (CIP) and norfloxacin (NOR) has been described. The method is based on the intramolecular energy transfer from organic acid to terbium (Tb3+) ion. Luminescence of terbium (III) complex with CIP (NOR), sorbed on the zeolite has been studied. Under optimized conditions the detection limit is 1 g/mL in urine and human plasma. 相似文献
79.
We derive for Hecke-Maass cusp forms on the full modular group a relation between the sum of the form at Heegner points (and
integrals over Heegner cycles) and the product of two Fourier coefficients of a corresponding form of half-integral weight.
Specializing to certain cycles we obtain the nonnegativity of theL-function of such a form at the center of the critical strip. These results generalize similar formulae known for holomorphic
forms.
Partially supported by NSF grant # DMS-9096262.
Partially supported by NSF grant # DMS-9102082. 相似文献
80.
BACKGROUND: Immunity against the T cell receptor (TCR) is considered to play a central role in the regulation of experimental allergic encephalomyelitis (EAE), a model system of autoimmune disease characterized by a restricted usage of TCR genes. Methods of specific vaccination against the TCR of pathogenetic T cells have included attenuated T cells and synthetic peptides from the sequence of the TCR. These approaches have led to the concept that anti-idiotypic immunity against antigenic sites of the TCR, which are a key regulatory element in this disease. METHODS: The present study in the Lewis rat used a conventional idiotypic immunization based on antigenized antibodies expressing selected peptide sequences of the Vbeta8.2 TCR (93ASSDSSNTE101 and 39DMGHGLRLIHYSYDVNSTEKG59). RESULTS: The study demonstrates that vaccination with antigenized antibodies markedly attenuates, and in some instances, prevents clinical EAE induced with the encephalitogenic peptide 68GSLPQKSQRSQDENPVVHF88 in complete Freunds' adjuvant (CFA). Antigenized antibodies induced an anti-idiotypic response against the Vbeta8.2 TCR, which was detected by ELISA and flowcytometry. No evidence was obtained of a T cell response against the corresponding Vbeta8.2 TCR peptides. CONCLUSIONS: The results indicate that antigenized antibodies expressing conformationally-constrained TCR peptides are a simple means to induce humoral anti-idiotypic immunity against the TCR and to vaccinate against EAE. The study also suggests the possibility to target idiotypic determinants of TCR borne on pathogenetic T cells to vaccinate against disease. 相似文献