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排序方式: 共有187条查询结果,搜索用时 15 毫秒
31.
Vinod Kumar Yata P. Gopinath Siddhartha Sankar Ghosh 《Applied biochemistry and biotechnology》2012,167(7):2103-2116
Nonmammalian cytosine deaminases (CDs) have been investigated for last 30?years in the context of cancer therapy. The therapeutic effect of CD is based on its ability to catalyze the conversion of nontoxic prodrug 5-fluorocytosine (5FC) into the anticancer drug 5-fluorouracil (5FU) by deamination of the number 4 carbon of 5FC. This deamination property of CD has been explored to develop innovative therapeutic approach for treatment of cancer. A general overview is needed for the identification of efficient cytosine deaminases for potential use in cancer therapy. In this review, we have discussed about nonmammalian CDs for a variety of prodrug gene/enzyme therapy applications with several recent examples. Finally, we have provided a prospective on the future aspects of CDs and their applications in cancer therapy. 相似文献
32.
Vanadyl acetylacetonate,VO(acac)2,has been found to be very effective catalyst for synthesis of a variety of benzimidazoles under solvent-free condition.The methodology involves the exposure of a mixture of o-phenylenediamine and a selected aromatic carboxylic acid/aldehyde to microwave radiation without the use of any solvent or supporting agents.The benzimidazoles were obtained in quick time with high yields. 相似文献
33.
Avraham?AizenbudEmail author Dmitry?Gourevitch Siddhartha?Sahi 《Israel Journal of Mathematics》2015,206(1):39-88
The notion of derivatives for smooth representations of GL(n, ? p ) was defined in [BZ77]. In the archimedean case, an analog of the highest derivative was defined for irreducible unitary representations in [Sah89] and called the “adduced” representation. In [AGS] derivatives of all orders were defined for smooth admissible Fréchet representations (of moderate growth).A key ingredient of this definition is the functor of twisted coinvariants with respect to the nilradical of the mirabolic subgroup. In this paper we prove exactness of this functor and compute it on a certain class of representations. This implies exactness of the highest derivative functor, and allows to compute highest derivatives of all monomial representations.In [AGS] these results are applied to finish the computation of adduced representations for all irreducible unitary representations and to prove uniqueness of degenerate Whittaker models for unitary representations. 相似文献
34.
Prithankar Pramanik Debdatta Halder Siddhartha Sankar Jana Suhrit Ghosh 《Macromolecular rapid communications》2016,37(18):1499-1506
The synthesis, micellar aggregation, and pH‐triggered intracellular drug delivery ability of an amphiphilic statistical copolymer (P2) are studied. Two methacrylate derivatives, one containing a hydrophilic pendant and the other containing a hydrophobic pendant chain, are copolymerized to produce P2. The hydrophobic pendant chain is linked to the polymer backbone by a β‐thiopropionate linkage, known to undergo slow hydrolysis at mild acidic pH. P2 forms a multimicellar cluster in water with a critical aggregation concentration of 0.02 mg mL−1 and encapsulates a hydrophobic guest such as pyrene, Nile red, or the anti‐cancer drug doxorubicin (Dox). Sustained release of the entrapped Dox (80% after 100 h) is noticed at pH 5.2, while release is significantly slower (35% after 100 h) at pH 7.4. Acidic hydrolysis of the β‐thiopropionate linkage leading to the reduction of the hydrophobicity is established as the cause for micellar disassembly and triggered drug release. Cell‐culture studies with the human breast cancer cell line, MCF‐7, reveal biocompatibility of P2 (below 150 μg mL−1). It is further tested for intracellular delivery of Dox. MCF‐7 cells remain healthy at pH 7.4 but become unhealthy at pH 5.2 when treated with a Dox‐loaded P2 micelles.
35.
Marcia Nitschke Siddhartha G. V. A. O. Costa Jonas Contiero 《Applied biochemistry and biotechnology》2010,160(7):2066-2074
Soybean oil soapstock was utilized as an alternative carbon source for the production of rhamnolipids by Pseudomonas aeruginosa LBI strain. The chemical composition and properties of the rhamnolipid mixture obtained were determined to define its potential
applications. The chemical characterization of the rhamnolipid has revealed the presence of ten different homologues. The
monorhamnolipid RhaC10C10 and the dirhamnolipid Rha2C10C10 were the main components of the mixture that showed predominance of 44% and 29%, respectively, after 144-h of cultivation.
The biosurfactant was able to form stable emulsions with several hydrocarbons and showed excellent emulsification for soybean
oil and chicken fat (100%). The rhamnolipid removed 67% of crude oil present in sand samples and presented antimicrobial activity
against Bacillus cereus and Mucor miehei at 64 μg/mL and inhibition of Neurospora crassa, Staphylococcus aureus, and Micrococcus luteus at 256 μg/mL. The results demonstrated that the rhamnolipid produced in soybean oil soapstock can be useful in environmental
and food industry applications. 相似文献
36.
One step synthesis of C-dots by microwave mediated caramelization of poly(ethylene glycol) 总被引:2,自引:0,他引:2
A rapid, simple and one step microwave mediated method for synthesizing C-dots using poly(ethylene glycol) (PEG) as a precursor and passivating agent is reported. The C-dots possessed low cytotoxicity, were amenable to separation by electrophoresis, photostable and entered cancer cells, making them suitable candidates for bioimaging and biolabelling. 相似文献
37.
Rajdip Roy Dr. Jolly Deb Dr. Siddhartha Sankar Jana Prof. Parthasarathi Dastidar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15320-15324
A simple strategy for designing salt‐based supramolecular gelators comprised of various nonsteroidal anti‐inflammatory drugs (NSAIDs) and amantadine (AMN) (an antiviral drug) has been demonstrated using a supramolecular synthon approach. Single‐crystal and powder X‐ray diffraction established the existence of the well‐studied gel‐forming 1D supramolecular synthon, namely, primary ammonium monocarboxylate (PAM) synthon in all the salts. Remarkably five out of six salts were found to be capable of gelling methyl salicylate (MS)—an important ingredient in commercially available topical gels; one such selected biocompatible salt displayed an anti‐inflammatory response in prostaglandin E2 (PGE2) assay, thereby indicating their plausible biomedical applications. 相似文献
38.
Siddhartha Sahi 《Linear algebra and its applications》2010,432(10):2524-2528
We prove a conjecture of Dubey et al. on the change in the resolvent of a nonnegative matrix if its entries are decreased, and discuss applications to mathematical economics. 相似文献
39.
Splittings of a free group correspond to embedded spheres in the 3-manifold M = # k S 2 × S 1. These can be represented in a normal form due to Hatcher. In this paper, we determine the normal form in terms of crossings of partitions of ends corresponding to normal spheres, using a graph of trees representation for normal forms. In particular, we give a constructive proof of a criterion determining when a conjugacy class in π 2(M) can be represented by an embedded sphere. 相似文献
40.
Siddhartha Gadgil 《印度理论与应用数学杂志》2011,42(4):225-237
To a reasonable approximation, a secondary structures of RNA is determined by Watson-Crick pairing without pseudo-knots in such a way as to minimise the number of unpaired bases. We show that this minimal number is determined by the maximal conjugacy-invariant pseudo-norm on the free group on two generators subject to bounds on the generators. This allows us to construct lower bounds on the minimal number of unpaired bases by constructing conjugacy invariant pseudo-norms. 相似文献