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排序方式: 共有1601条查询结果,搜索用时 31 毫秒
971.
Arissa Pickler Andrea Mantuano Carla L. Mota Tayane Tanure Luanna Serqueira Samara Ferreira-Machado Cláudio S.C. Lau Camila Salata Carlos E. de Almeida Alessandro Nascimento Gabriela Sena Gabriel Fidalgo Marcos V. Colaço Matteo Altissimo Diana E. Bedolla Alessandra Gianoncelli Delson Braz Regina C. Barroso 《X射线光谱测定》2019,48(5):422-431
Hypertension is one of the major public health problems worldwide. It can cause severely alterations in artery structure and function such as vascular remodeling. Angiotensin II (Ang II) has been linked to vascular dysfunction. It has been shown that blockade of the Ang II type 1 receptor with an Ang II receptor blocker (ARBs) may reverse vascular pathology independently of blood pressure lowering. There is therefore a special interest in establishing whether antihypertensive treatment may correct in part or completely the structural and functional alterations of arteries. Several studies have shown regression of structural remodeling or of functional alterations of small arteries in spontaneously hypertensive rats (SHR) treated with ARBs agents. However, its efficiency was not verified at elemental level in the literature. Knowledge of the elemental distribution in tissues has a great importance in the study of diseases, because chemical imbalance can alter biological functions. Elemental semiquantitative microanalysis in the coronary artery of normotensive, SHRs, and SHRs rats treated with ARBs (losartan and olmesartan) was performed using low energy X-ray fluorescence maps acquired on TwinMic X-ray spectromicroscopy station, located at the Elettra synchrotron radiation facility. Morphological changes in coronary samples were also investigated. The results demonstrate that despite the antihypertensive agents used belong to the same class, their capacities to revert chemical and structural changes in the coronary arteries caused by hypertension are different. 相似文献
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α‐Aminoxy Oligopeptides: Synthesis,Secondary Structure,and Cytotoxicity of a New Class of Anticancer Foldamers 下载免费PDF全文
Daniela Diedrich Ana J. Rodrigues Moita Anja Rüther Benedikt Frieg Dr. Guido J. Reiss Dr. Astrid Hoeppner Prof. Dr. Thomas Kurz Prof. Dr. Holger Gohlke Dr. Steffen Lüdeke Prof. Dr. Matthias U. Kassack Dr. Finn K. Hansen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17600-17611
α‐Aminoxy peptides are peptidomimetic foldamers with high proteolytic and conformational stability. To gain an improved synthetic access to α‐aminoxy oligopeptides we used a straightforward combination of solution‐ and solid‐phase‐supported methods and obtained oligomers that showed a remarkable anticancer activity against a panel of cancer cell lines. We solved the first X‐ray crystal structure of an α‐aminoxy peptide with multiple turns around the helical axis. The crystal structure revealed a right‐handed 28‐helical conformation with precisely two residues per turn and a helical pitch of 5.8 Å. By 2D ROESY experiments, molecular dynamics simulations, and CD spectroscopy we were able to identify the 28‐helix as the predominant conformation in organic solvents. In aqueous solution, the α‐aminoxy peptides exist in the 28‐helical conformation at acidic pH, but exhibit remarkable changes in the secondary structure with increasing pH. The most cytotoxic α‐aminoxy peptides have an increased propensity to take up a 28‐helical conformation in the presence of a model membrane. This indicates a correlation between the 28‐helical conformation and the membranolytic activity observed in mode of action studies, thereby providing novel insights in the folding properties and the biological activity of α‐aminoxy peptides. 相似文献
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Matthias Van den Bergh Andra Krajnc Stefan Voorspoels Sergio Rodrigues Tavares Steven Mullens Isabelle Beurroies Guillaume Maurin Gregor Mali Dirk E. De Vos 《Angewandte Chemie (International ed. in English)》2020,59(33):14086-14090
Perfluorinated alkylated substances (PFASs) are widely used in industrial and commercial applications, leading to a widespread occurrence of these persistent and harmful contaminants in our environment. Removal of these compounds from surface and waste waters is being mandated by European and U.S. governments. Currently, there are no treatment techniques available that lower the concentrations of these compounds for large water bodies in a cost‐ and energy‐efficient way. We hereby propose a hydrophobic, all‐silica zeolite Beta material that is a highly selective and high‐capacity adsorbent for PFASs, even in the presence of organic competitors. Advanced characterization data demonstrate that the adsorption process is driven by a very negative adsorption enthalpy and favorable steric factors. 相似文献