排序方式: 共有71条查询结果,搜索用时 15 毫秒
41.
Khosrow Zamani Nasim Hassan Rama Rashid Iqbal 《Journal of heterocyclic chemistry》2000,37(6):1651-1654
The condensation of homophthalic acid (1) with 3‐methoxybenzoyl chloride, followed by demethylation gave 3‐(3‐hydroxyphenyl)isocoumarin (3b). Reaction of (3b) with α‐tetraacetobromo glucose yielded tetraacetylhomalicine (3d), which was deacetylated to homalicine (3e). 相似文献
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In this paper, a generalization of the level dependent Quasi-Birth-and-Death (QBD) chains is presented. We analyze nested level dependent QBD chains and provide the complete characterization of their fundamental matrices in terms of minimal non-negative solutions of a number of matrix quadratic equations. Our results provide mixed matrix-geometric solution for the stationary distribution of nested QBD chains. Applications in overload control in communication networks are also discussed. 相似文献
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A facile preparation of the title compound by 1,3-dipolar cycloaddition reaction of benzonitrile oxides with isatin imines or isatin diimines, in excellent yield, are reported. 相似文献
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The impact of in-line coagulation pre-treatment of secondary effluent on the operation of an immersed hollow-fibre ultrafiltration membrane pilot was evaluated as part of a larger study on optimising phosphorus removal. The efficacy of alum and ferric chloride was investigated, with an emphasis on alum use. Both coagulants were found to shift the particle-size distribution of organic matter in the feed towards larger fractions, with a notable reduction in colloidal matter. This was reflected in a reduction of both average daily transmembrane pressure increases, as well as a reduction of transmembrane pressure increases within backpulse intervals. Fouling reduction was observed with both lower and higher membrane packing density modules (membrane surface areas of 55.7 and 62.7 m2/module). The results of one-way analysis of variance (ANOVA) testing indicate that for this pilot system, chemical pre-treatment and solids concentrations in the feed water played a statistically significant role in determining transmembrane pressure variations. Membrane packing density and membrane production method did not exhibit a statistically significant effect on transmembrane pressure under the conditions of this study. 相似文献
45.
Highly Regioselective and Diastereoselective,One‐Pot,Four‐Component Synthesis of Novel Spiroindenoquinoxalineindolizidine Derivatives 下载免费PDF全文
Mehdi Moemeni Hamid Arvinnezhad Saadi Samadi Farbod Salahi Khosrow Jadidi Behrouz Notash 《Journal of heterocyclic chemistry》2015,52(3):944-948
A one‐pot, four‐component procedure for the synthesis of novel spiroindenoquinoxalineindolizidines with high regioselectivity and diastereoselectivity from the 1,3‐dipolar cycloaddition of azomethine ylides, generated from indenoquinoxalines and pipecolinic acid, and chalcones is described. The reaction occurs under reflux of ethanol as a green solvent and in the absence of any catalyst. The cycloadducts are obtained purely without future purification. The regiochemistry and stereochemistry of resultant cycloadducts have been determined by several 2D‐NMR spectroscopic techniques and X‐ray single crystal diffraction. 相似文献
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Andrea Spinaci Catia Lambertucci Michela Buccioni Diego Dal Ben Claudia Graiff Maria Cristina Barbalace Silvana Hrelia Cristina Angeloni Seyed Khosrow Tayebati Massimo Ubaldi Alessio Masi Karl-Norbert Klotz Rosaria Volpini Gabriella Marucci 《Molecules (Basel, Switzerland)》2022,27(8)
The A2A adenosine receptor (A2AAR) is one of the four subtypes activated by nucleoside adenosine, and the molecules able to selectively counteract its action are attractive tools for neurodegenerative disorders. In order to find novel A2AAR ligands, two series of compounds based on purine and triazolotriazine scaffolds were synthesized and tested at ARs. Compound 13 was also tested in an in vitro model of neuroinflammation. Some compounds were found to possess high affinity for A2AAR, and it was observed that compound 13 exerted anti-inflammatory properties in microglial cells. Molecular modeling studies results were in good agreement with the binding affinity data and underlined that triazolotriazine and purine scaffolds are interchangeable only when 5- and 2-positions of the triazolotriazine moiety (corresponding to the purine 2- and 8-positions) are substituted. 相似文献
47.
Numerical Algorithms - The main aim of this research study is to present a new and efficient numerical method based on the second kind Chebyshev wavelets for solving the general form of distributed... 相似文献
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Nina Yu. Kostina Sebastien Blanquer Ognen Pop‐Georgievski Khosrow Rahimi Barbara Dittrich Anita Hcherl Jií Michlek Dirk W. Grijpma Cesar Rodriguez‐Emmenegger 《Macromolecular bioscience》2019,19(4)
Stereolithography‐assisted fabrication of hydrogels of carboxybetaine methacrylamide (CBMAA) and a α,ω‐methacrylate poly(d,l ‐lactide‐block‐ethylene glycol‐block‐ d,l ‐lactide) (MA‐PDLLA‐PEG‐PDLLA‐MA) telechelic triblock macromer is presented. This technique allows printing complex structures with gyroid interconnected porosity possessing extremely high specific area. Hydrogels are characterized by infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and laser scanning confocal microscopy (LSCM). The copolymerization with zwitterionic comonomer leads hydrogels with high equilibrium water content (EWC), up to 700% while maintaining mechanical robustness. The introduction of carboxybetaine yields excellent resistance to nonspecific protein adsorption while providing a facile way for specific biofunctionalization with a model protein, fluorescein isothiocyanate labeled bovine serum albumin (BSA). The homogeneous protein immobilization across the hydrogel pores prove the accessibility to the innermost pore volumes. The remarkably low protein adsorption combined with the interconnected nature of the porosity allowing fast diffusion of nutrient and waste product and the mimicry of bone trabecular, makes the hydrogels presented here highly attractive for tissue engineering. 相似文献
50.
A simple and efficient method for the synthesis of chiral biphenylbisoxazoline ligands was developed. The bishydroxylamide precursors of ligands showed a dynamic atropselective resolution effect in the crystallization process. When biphenylbisoxazoline ligands were coordinated to tetrakis(acetonitrile)copper(I) hexafluorophosphate, it resulted in the formation of only a single diastereomer complex (S,aS,S), which behaved as a catalyst for the enantioselective allylic oxidation of cycloolefins. The enantioselectivity, yield, and rate of this reaction were optimized under different conditions, such as a change of solvents, temperature, and additives and also using various copper salts. The use of SBA-15 mesoporous silica as an additive played a crucial role in increasing the efficiency of the reaction. 相似文献