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排序方式: 共有508条查询结果,搜索用时 15 毫秒
81.
Tanja Smolka Reiner Sustmann Roland Boese 《Advanced Synthesis \u0026amp; Catalysis》1999,341(4):378-383
A hydrogen-bonded network in a 1:1 cocrystal of phenazine and meso-1,2-diphenyl-1,2-ethandiol places phenazine and diol in such a way that a thermally reversible photochromism is produced. The structure of the cocrystal is determined by X-ray crystallography. Thermally reversible changes in the UV/Vis and IR spectrum on irradiation, in combination with the generation of paramagnetism (ESR) lead to the interpretation that a light induced electron transfer between two phenazine molecules is followed by a double proton transfer to the nitrogen atoms of the radical anion of phenazine. 相似文献
82.
Vicik R Busemann M Gelhaus C Stiefl N Scheiber J Schmitz W Schulz F Mladenovic M Engels B Leippe M Baumann K Schirmeister T 《ChemMedChem》2006,1(10):1126-1141
A comprehensive screening of N-acylated aziridine (aziridide) based cysteine protease inhibitors containing either Boc-Leu-Caa (Caa=cyclic amino acid), Boc-Gly-Caa, or Boc-Phe-Ala attached to the aziridine nitrogen atom revealed Boc-(S)-Leu-(S)-Azy-(S,S)-Azi(OBn)(2) (18 a) as a highly potent cathepsin L (CL) inhibitor (K(i)=13 nM) (Azy=aziridine-2-carboxylate, Azi=aziridine-2,3-dicarboxylate). Docking studies, which also accounted for the unusual bonding situations (the flexibility and hybridization of the aziridides) predict that the inhibitor adopts a Y shape and spans across the entire active site cleft, binding into both the nonprimed and primed sites of CL. 相似文献
83.
84.
Victor Wessels Gwénaël Le Mené Stefan F. Fischerauer Tanja Kraus Annelie‐Martina Weinberg Peter J. Uggowitzer Jörg F. Löffler 《Advanced Engineering Materials》2012,14(6):B357-B364
A study of Mg‐based bulk metallic glasses (BMGs) as biodegradable bone implants is presented. The implantation site can affect performance, so the BMGs were evaluated in vivo in rat femurs using µ‐CT scans at various times for more than 90 days. Estimates of H2 evolution correlate well with previous in vitro studies and bone–implant contact is similar to that for Ti pins. One potential drawback of Mg‐based BMGs in this application is embrittlement due to structural relaxation. Here, relaxation at 20 and 37 °C is examined, and an increase in the characteristic relaxation time, from 10 to 30 days at 20 °C, is observed as Zn increases from 29 to 32 at.%, correlating with dramatically reduced hydrogen evolution. 相似文献
85.
Characterization of lactic acid bacteria isolated from traditionally made Serbian Cheese and evaluation of their antagonistic potential against Enterobacteriaceae
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86.
Potassium Chloride‐Based Salt Substitutes: A Critical Review with a Focus on the Patent Literature
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Katica Cepanec Sašenka Vugrinec Tanja Cvetković Jasmina Ranilović 《Comprehensive Reviews in Food Science and Food Safety》2017,16(5):881-894
High dietary sodium intake (DSI) represents a major health‐related public issue in most countries all over the world. Such a diet can lead to increased risk of hypertension and related cardiovascular diseases. This situation has resulted in important public policies for various salt reduction strategies. One of these is based on the use of salt substitutes or salts with reduced sodium content. Among several options, potassium chloride (KCl) has proved to be a key nutritional ingredient for this purpose. It provides similar properties like common salt (NaCl), but with several unwanted side effects, of which the most important have relatively offensive side tastes: bitter, acrid, and metallic. To successfully formulate KCl‐based salt substitutes, numerous taste‐improving agents and formulation concepts have been used. The field of salt substitutes is mainly described in the patent literature. Since patents are both scientific and legal documents, careful and critical consideration is required when using them as a source of scientific information. This review brings a deep insight into the area of KCl‐based salt substitutes with a focus on the patent literature through the eyes of food science and technology. The most important classes of taste‐improving agents that have been employed in numerous formulation concepts of KCl‐based salt substitutes are nutritionally acceptable mineral salts; food acids, amino acids, and their nutritionally acceptable salts; simple carbohydrates and sugar substitutes; food polymers; umami ingredients; spices, vegetables, and flavors; miscellaneous taste improvers; as well as a plethora of their specific combinations. A critical review of the respective patent literature is given. 相似文献
87.
Differing cytotoxicity and bioavailability of selenite,methylselenocysteine, selenomethionine,selenosugar 1 and trimethylselenonium ion and their underlying metabolic transformations in human cells
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88.
Thomas Ingram Sandra Storm Philipp Glembin Stephan Bendt Désirée Huber Tanja Mehling Prof. Dr.‐Ing. Irina Smirnova 《化学,工程师,技术》2012,84(6):840-848
Aqueous nonionic surfactant solutions split into two phases if the temperature is increased beyond a certain temperature, the so‐called cloud point temperature. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction. In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. Phase equilibria of the binary system Triton X‐114/water and the ternary system Triton X‐114/water/phenol were measured. Based on these data the cloud point extraction was implemented in a continuous stirred extraction column. It was found, that increasing temperature within the column reduces the loss of surfactant and leads to an increasing enrichment factor. This work demonstrates that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in continuous extraction columns. 相似文献
89.
90.
非织造布在世界范围内广泛生产.全球标准是非织造布生产的一个竞争因素.目前,非织造布在市场中的优势不仅是价格便宜,而且质量优良.因此,为了保持非织造布的市场,有必要提高非织造布质量.在线检测系统可检测破洞、薄区、厚区等疵点,但影响非织造布质量的不仅仅是疵点,还取决于其光学均匀性.尤其对于面密度较小(如15 g/m2)的非织造布,明显的不规则纤维分布会影响顾客的主观评价.阐述了一种代表主观评价的客观图像分析方法. 相似文献