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排序方式: 共有289条查询结果,搜索用时 15 毫秒
61.
Avijit Pramanik 《Tetrahedron》2009,65(11):2196-1738
A novel quinoline based tripodal receptor that shows intermolecular excimer emission has been designed and synthesized. The excimer emission has been used to confirm the selective recognition of phosphate ion. It combines three different types of N-donor with the elegant fluorescent signaling properties. 相似文献
62.
Effect of porosity and pore size distribution on the low-frequency dielectric response, in the range 0.01–100 kHz, in sintered
ZrO2—8 mol% Y2O3 ceramic compacts have been investigated. Small-angle neutron scattering (SANS) technique has been employed to obtain the
pore characteristics like pore size distribution, specific surface area etc. It has been observed that the real and the imaginary
parts of the complex dielectric permittivity, for the specimens, depend not only on the porosity but also on the pore size
distribution and pore morphology significantly. Unlike normal Debye relaxation process, where the loss tangent vis-à-vis the
imaginary part of the dielectric constant shows a pronounced peak, in the present case the same increases at lower frequency
region and an anomalous non-Debye type relaxation process manifests. 相似文献
63.
Mazumder UK Gupta M Karki SS Bhattacharya S Rathinasamy S Thangavel S 《Chemical & pharmaceutical bulletin》2004,52(2):178-185
In search of potential anticancer drug candidates in ruthenium complexes, a series of mononuclear ruthenium complexes of the type [Ru(phen)(2)(nmit)]Cl(2) (Ru1), [Ru(bpy)(2)(nmit)]Cl(2) (Ru2), [Ru(phen)(2)(icpl)]Cl(2) (Ru3), Ru(bpy)(2)(icpl)]Cl(2) (Ru4) (phen=1,10-phenanthroline; bpy=2,2'-bipyridine; nmit=N-methyl-isatin-3-thiosemicarbazone, icpl=isatin-3-(4-Cl-phenyl)thiosemicarbazone) and [Ru(phen)(2)(aze)]Cl(2) (Ru5), [Ru(bpy)(2)(aze)]Cl(2) (Ru6) (aze=acetazolamide) and [Ru(phen)(2)(R-tsc)](ClO(4))(2) (R=methyl (Ru7), ethyl (Ru8), cyclohexyl (Ru9), 4-Cl-phenyl (10), 4-Br-phenyl (Ru11), and 4-EtO-phenyl (Ru12), tsc=thiosemicarbazone) were prepared and characterized by elemental analysis, FTIR, (1)H-NMR and FAB-MS. Effect of these complexes on the growth of a transplantable murine tumor cell line (Ehrlich Ascites Carcinoma) and their antibacterial activity were studied. In cancer study the effect of hematological profile of the tumor hosts have also been studied. In the cancer study, the complexes Ru1-Ru4, Ru10 and Ru11 have remarkably decreased the tumor volume and viable ascitic cell count as indicated by trypan blue dye exclusion test (p<0.05). Treatment with the ruthenium complexes prolonged the lifespan of Ehrlich Ascites Carcinoma (EAC) bearing mice. Tumor inhibition by the ruthenium chelates was followed by improvements in hemoglobin, RBC and WBC values. All the complexes showed antibacterial activity, except Ru5 and Ru6. Thus, the results suggest that these ruthenium complexes have significant antitumor property and antibacterial activity. The results also reflect that the drug does not adversely affect the hematological profiles as compared to that of cisplatin on the host. 相似文献
64.
Harjyoti Thakuria Ballav Moni Borah Avijit Pramanik Gopal Das 《Journal of chemical crystallography》2007,37(12):807-816
Abstract This paper describes the solid-state synthesis and systematic studies of versatile supramolecular self-assembly of 14 new
series of organic salt cocrystals. Hierarchical self-assembly in the solid state utilizes the cooperative interaction of hydrogen
bonding, electrostatic and π–π interactions. These salts are crystallized as a highly ordered self-assembly directed by intermolecular
non-covalent interaction.
Index Abstract Fourteen cocrystals of organic salt have been characterized by single crystal X-ray diffraction and their solid-state packing
pattern has been compared.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
65.
A novel fluorescent probe for the copper(II) ion in mixed aqueous media, based on fluorescence quenching mechanism with noticeable color change from light to dark yellow, was designed and synthesized. It also exhibited high selectivity for acetate in acetonitrile over other common anions in the near infrared region (NIR) accompanied with exciting color changes from light yellow to pink. Hence sensor 1 ascertains its dual chemosensing ability toward Cu(II) and acetate ions as evidenced by competitive experiments. 相似文献
66.
Koushik Mazumder Swarbhanu Sarkar Asish Kumar Sen 《Journal of carbohydrate chemistry》2013,32(9):673-685
The terminal disaccharide of the O-antigenic polysaccharide of Vibrio cholerae O37, 4-O-methyl-α-D-QuiNAc-(1→4)-α-d-QuiNAc, was synthesized as methyl glycoside involving glycosylation between glycosyl donor ethyl 2-azido-3-O-benzyl-2,6-dideoxy-4-O-methyl-6-iodo-1-thio-α-d-glucopyranoside and glycosyl acceptor methyl 2-azido-3-O-benzyl-2,6-dideoxy-6-iodo-α-d-glucopyranoside. Dehalogenation, global deprotection, and reduction of the azide to amine were effected in one step by catalytic hydrogenation. It was followed by selective N-acetylation to give the desired deprotected disaccharide. 相似文献
67.
Hong‐Jyune Lin Avijit Kumar Adak L. Vijaya Raghava Reddy Prof. Shih‐Hsiung Wu Prof. Chun‐Cheng Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(24):7989-7998
A method for the stereocontrolled synthesis of a bacterial phosphoglycolipid (PGL 1 ) isolated from thermophilic bacteria is described. The key features of the synthesis include a highly α‐selective glycosylation reaction between a trichloroacetimidate donor and a D ‐lyxose‐derived primary alcohol acceptor and the late‐stage incorporation of the phospholipid. 相似文献
68.
Shyamaprosad Goswami Avijit Kumar Das Krishnendu Aich Abhishek Manna Hoong-Kun Fun Ching Kheng Quah 《Supramolecular chemistry》2013,25(2):94-104
A simple novel receptor, designed to have a combination of both oxygen and nitrogen-binding sites for metal ion and hydrogen bond donor sites for anion, was synthesised. The receptor has been explored for the selective detection of cation Al3+ over the other interfering metal ions and anion AcO? against a range of physiologically relevant anions in the fluorescence spectroscopy. The receptor shows a different response to aluminium and acetate in the emission spectra. The binding isotherm and detection limit demonstrate that the receptor is an excellent fluorometric probe for Al3+ and AcO? . 相似文献
69.
Gbemileke A. Ogunranti Oben Ceryan Avijit Banerjee 《European Journal of Operational Research》2021,288(2):420-435
This paper analyzes a decentralized global supply chain under a newsvendor setting, where a supplier delivers a certain quantity of a single product to a buyer in accordance with the terms of a mutually agreed upon contract. This contract is signed prior to the delivery of the product and subsequent payment, thus, exposing the supply chain to the risk of currency exchange rate fluctuations. We propose two types of currency exchange rate flexibility contracts to explore the characteristics of exchange rate risk mitigation policies for the buyer and the supplier. Furthermore, we investigate the effects of the contract structures on the optimal order quantity, as well as the expected profits of both supply chain members. Our results show that the optimal order quantity of the buyer decreases when the wholesale price is uncertain due to exchange rate volatility. Also, both our proposed contracts tend to improve the expected profits of both the buyer and the supplier, when the payment is made in the supplier’s currency, indicating the desirability of adopting such contractual agreements from the perspective of both parties. On the other hand, when the payment is made in the buyer’s currency, our suggested contracts do not yield such win-win scenarios. Finally, we examine the effectiveness of availing the services of a local vendor, which is capable of satisfying any demand in excess of the quantity ordered from the foreign source with short notice, in order to mitigate the risks associated with an overseas order. 相似文献
70.
Nairwita Mazumder Ritabrata Biswas Subenoy Chakraborty 《General Relativity and Gravitation》2011,43(5):1337-1345
The work deals with the thermodynamics of the universe bounded by the event horizon. The matter in the universe has three
constituents namely dark energy, dark matter and radiation in nature and interaction between then is assumed. The variation
of entropy of the surface of the horizon is obtained from unified first law while matter entropy variation is calculated from
the Gibbss’ law. Finally, validity of the generalized second law of thermodynamics is examined and conclusions are written
point wise. 相似文献