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71.
Aziridines are attracting interest as protease inhibitors, which might be used, e.g., for treatment of parasitic diseases. Within the framework of greater projects dealing with the search of new selective protease inhibitors, a huge number of aziridines with two stereogenic centers will be synthesized. Thus, a fast and reliable screening method for the evaluation of the isomeric composition is needed. Robust baseline separations were obtained using heptakis(2,3-di-O-acetyl-6-sulfato)beta-CD (HDAS) in acidic methanol and sulfated beta-CD in acidic phosphate buffer. With HDAS the resolutions were higher and migration times shorter. Thus, the method will be used as a screening method for further isomeric mixtures of aziridines. 相似文献
72.
In this work target transform fitting (TTF) is proposed as a hard-model based data analysis method to analyze differential pulse polarograms recorded in a successive metal complexation system. In such cases, equations for both complexation equilibria and shape of the differential pulse polarogram for individual species are available. Utilizing TTF to fit these models in separate stages, stability constants and E1/2 values of species were estimated. In the first stage, E1/2 values of all species were acquired using the shape-equation of voltamograms and projection of a test vector into the row space of data matrix. In the second stage, using equations derived from relationships among species’ concentrations in complexation equilibria and a non-linear parameter fitting algorithm, the optimum values of overall formation constants were estimated. Finally, rank annihilation (RA) method was employed for calculation of diffusion coefficients. In spite of the fact that proposed method is a hard-model based approach, obtained results show that analysis can be performed correctly even in presence of unknown species. The reliability of the method was tested analyzing simulated data and also polarograms obtained from Cd(II) and 1, 10-phenanthroline complexation system. This experimental system yields three successive complexes which are relatively inert from electrochemical point of view. The results were in a good agreement with reported results in the literature. 相似文献
73.
We characterize right Noetherian rings over which all simple modules are almost injective. It is proved that R is such a ring, if and only if, the complements of semisimple submodules of every R-module M are direct summands of M, if and only if, R is a finite direct sum of right ideals Ir, where Ir is either a Noetherian V-module with zero socle, or a simple module, or an injective module of length 2. A commutative Noetherian ring for which all simple modules are almost injective is precisely a finite direct product of rings Ri, where Ri is either a field or a quasi-Frobenius ring of length 2. We show that for commutative rings whose all simple modules are almost injective, the properties of Kasch, (semi)perfect, semilocal, quasi-Frobenius, Artinian, and Noetherian coincide. 相似文献
74.
Safari Meysam Yamini Yadollah Masoomi Mohammad Yaser Morsali Ali Mani-Varnosfaderani Ahmad 《Mikrochimica acta》2017,184(5):1555-1564
Microchimica Acta - The authors describe the preparation of two kinds of metal-organic frameworks (MOFs), referred to as TMU-8 and TMU-9. The MOFs were applied to the preconcentration of the ions... 相似文献
75.
Acikbas Yaser Aksoy Mehmet Aksoy Merve Karaagac Damla Bastug Elif Kursunlu Ahmed Nuri Erdogan Matem Capan Rifat Ozmen Mustafa Ersoz Mustafa 《Journal of inclusion phenomena and macrocyclic chemistry》2021,100(1-2):39-54
Journal of Inclusion Phenomena and Macrocyclic Chemistry - Pillar[n]arene is one of the most favorited supramolecular materials that possess a special chiral structure. The major property of... 相似文献
76.
We report a novel method for formation of self-organized single-standing carbon nanotubes by customizing a plasma-based process. The growth of carbon nanotubes by plasma-enhanced chemical vapor deposition provides suitable grounds to utilize plasma–solid interactions for nanopatterning. The bulk plasma is utilized to fabricate carbon nanotubes on the prepatterned Ni catalyst which in turn can confine the plasma to the growth region. The plasma localization leads to a dielectrophoretic force exerted on Ni atoms and can be engineered in order to grow a specific pattern of self-organized single-standing carbon nanotubes. Numerical simulations based on the plasma localization and dielectrophoretic force confirmed the experimental results. This method provides a simple and cost-effective approach to obtain nanopatterned arrays of carbon nanotubes which can be used for fabrication of photonic and phononic crystals, self-gated field emission-based transistors and displays. 相似文献
77.
A Vaidya spacetime is considered for gravitational collapse of a type II fluid in the context of the Rastall theory of gravity. For a linear equation of state for the fluid profiles, the conditions under which the dynamical evolution of the collapse can give rise to the formation of a naked singularity are examined. It is shown that depending on the model parameters, strong curvature, naked singularities would arise as exact solutions to the Rastall's field equations. The allowed values of these parameters satisfy certain conditions on the physical reliability, nakedness, and the curvature strength of the singularity. It turns out that Rastall gravity, in comparison to general relativity, provides a wider class of physically reasonable spacetimes that admit both locally and globally naked singularities. 相似文献
78.
Said Moshawih Rabiatul Nur Amalia Abdullah Juperi Ganesh Sritheran Paneerselvam Long Chiau Ming Kai Bin Liew Bey Hing Goh Yaser Mohammed Al-Worafi Chee-Yan Choo Shobna Thuraisingam Hui Poh Goh Nurolaini Kifli 《Molecules (Basel, Switzerland)》2022,27(6)
Common wheat (Triticum aestivum), one of the world’s most consumed cereal grains, is known for its uses in baking and cooking in addition to its medicinal uses. As this plant’s medical benefits are enormous and scattered, this narrative review was aimed at describing the pharmacological activities, phytochemistry, and the nutritional values of Triticum aestivum. It is a good source of dietary fiber, resistant starch, phenolic acids, alkylresorcinols, lignans, and diverse antioxidant compounds such as carotenoids, tocopherols and tocotrienols. These constituents provide Triticum aestivum with a wide range of pharmacological properties, including anticancer, antimicrobial, antidiabetic, hypolipemic, antioxidant, laxative, and moisturizing effects. This review summarized the established benefits of wheat in human health, the mode of action, and different clinical, in vitro and in vivo studies for different varieties and cultivars. This review also gives an insight for future research into the better use of this plant as a functional food. More clinical trials, in vivo and in vitro studies are warranted to broaden the knowledge about the effect of Triticum aestivum on nutrition-related diseases prevention, and physical and mental well-being sustenance. 相似文献
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80.
Design,Synthesis, EPR‐Studies and Conformational Bias of Novel Spin‐Labeled DCC‐Analogues for the Highly Regioselective Labeling of Aliphatic and Aromatic Carboxylic Acids 下载免费PDF全文
Jan Philipp Gölz Dr. Yaser NejatyJahromy Mirko Bauer Ashraf Muhammad Dr. Gregor Schnakenburg Prof. Dr. Stefan Grimme Prof. Dr. Olav Schiemann Prof. Dr. Dirk Menche 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9591-9598
Novel types of spin‐labeled N,N′‐dicyclohexylcarbodiimides (DCC) are reported that bear a 2,2,6,6‐tetramethylpiperidinyloxyl (TEMPO) residue on one side and different aromatic and aliphatic cyclohexyl analogues on the other side of the diimide core. These readily available novel reagents add efficiently to aliphatic and aromatic carboxylic acids, forming two possible spin‐labeled amide derivatives with different radical distances of the resulting amide. The addition of aromatic DCC analogues proceeds with excellent selectivity, giving amides where the carboxylic acid is exclusively connected to the aromatic residue, while little or no selectivity was observed for the aliphatic congeners. The usefulness of these adducts in structural studies was demonstrated by EPR (electron paramagnetic resonance) measurements of biradical adducts of biphenyl‐4,4′‐dicarboxylic acids. These analyses also reveal high degrees of conformational bias for aromatic DCC derivatives, which further underlines the powerfulness of these novel reagents. This observation was further corroborated by quantum chemical calculations, giving a detailed understanding of the structural dynamics, while detailed information on the solid state structure of all novel reagents was obtained by X‐ray structure analyses. 相似文献