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1.
Hartmut Seliger Michael Hinz Sigalit Gura Boa Nitzan Shlomo Margel 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):1305-1307
Abstract The use of composite beads consisting of a 6 μm polystyrene core with 30 nm surface-bound silica particles to routine automatic oligodeoxynucleotide (ODN) synthesis is described. 相似文献
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Lyn D. Olson Carolyn A. Renshaw Shlomo Rottem Jila H. Boal 《FEMS microbiology letters》1993,108(1):47-51
Abstract Electrofusion of protoplasts of two mutant strains of Hansenula polymorpha resulted in high fusion and hybrid yields when the calcium ions present in the conventional fusion medium replaced by zinc ions. The optimal fusion conditions were an alignment field of 0.4 kV cm−1 strength and 2 MHz frequency for 30 s, followed by two consecutive pulses of 12 kV cm−1 strength and 15 μs duration. With 0.05–0.1 mM zinc ions in the fusion medium an average clone number of 104 –105 clones per 108 input cells was reached. The presence of about 0.6 mM magnesium ions in the zinc fusion medium was essential. 相似文献
4.
Yair Neuman Dan Assaf Yohai Cohen Mark Last Shlomo Argamon Newton Howard Ophir Frieder 《PloS one》2013,8(4)
Identifying metaphorical language-use (e.g., sweet child) is one of the challenges facing natural language processing. This paper describes three novel algorithms for automatic metaphor identification. The algorithms are variations of the same core algorithm. We evaluate the algorithms on two corpora of Reuters and the New York Times articles. The paper presents the most comprehensive study of metaphor identification in terms of scope of metaphorical phrases and annotated corpora size. Algorithms’ performance in identifying linguistic phrases as metaphorical or literal has been compared to human judgment. Overall, the algorithms outperform the state-of-the-art algorithm with 71% precision and 27% averaged improvement in prediction over the base-rate of metaphors in the corpus. 相似文献
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Bovine galactosyl transferase was found to utilize UDPglucose as a substrate and elicit disaccharide biosynthesis with glucose and N-acetylglucosamine as acceptors. The relative rate of glucosyl transferase with N-acetylglucosamine as acceptor was 0.3%, the rate for N-acetyllactosamine biosynthesis. This activity was also evidenced indirectly from NMR water proton relaxation experiments, and from Mn(II) ESR experiments. In direct experiments with radioactive UDPglucose, paper chromatography showed a product which migrated with cellobiose when glucose was the acceptor and a new, glucose-containing product which resulted when GlcNAc was the acceptor. Despite this marginally expanded specificity of the donor site, spin-label experiments with a covalently bound UDPgalactose analog reaffirmed the restrictive nature of the donor site against this non-glycosyl-like analog. 相似文献
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AC-3579 (2-N-methylpiperazinomethyl-1,3-diazafluoranthen 1-oxide) produces in rat hepatocytes a hypertrophy of the endoplasmic reticulum.Two possibilities that can explain this phenomenon are (1) that AC-3579 inactivates the phospholipases, and (2) that an AC-3579-lipid interaction hinders the enzymic activity.To demonstrate these hypotheses, a physicochemical model of biological membrane, the lipid-water interface, has been used. Dipalmitoyl dl-α-phosphatidylcholine was spread at the air-water interface, the enzymes (phospholipase A or phospholipase C) dissolved in the aqueous phase.The enzymic reaction was first studied with and without AC-3579 dissolved in the aqueous phase; no enzymic inactivation was observed. However in AC-3579- lipid complex completely inhibited the enzymic reaction in the case of phospholipase A.An explanation is given in terms of steric hindrance to the enzyme-substrate complex formation. 相似文献
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Avian oviductal fluids contain phosphorylating-dephosphorylating enzymes that might function in sperm-oocyte interactions. Phosphorprotein phosphatase and protein kinase have been purified 20-fold and 40-fold, respectively. The latter easily aggregates and is highly labile. Other properties are comparable to those of holoenzymes. 相似文献
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Benjamin D. Stevens John Litchfield Jeffrey A. Pfefferkorn Karen Atkinson Christian Perreault Paul Amor Kevin Bahnck Martin A. Berliner Jessica Calloway Anthony Carlo David R. Derksen Kevin J. Filipski Mike Gumkowski Charanjeet Jassal Margit MacDougall Brendan Murphy Paul Nkansah John Pettersen Yan Zhang 《Bioorganic & medicinal chemistry letters》2013,23(24):6588-6592
Glucokinase (hexokinase IV) continues to be a compelling target for the treatment of type 2 diabetes given the wealth of supporting human genetics data and numerous reports of robust clinical glucose lowering in patients treated with small molecule allosteric activators. Recent work has demonstrated the ability of hepatoselective activators to deliver glucose lowering efficacy with minimal risk of hypoglycemia. While orally administered agents require a considerable degree of passive permeability to promote suitable exposures, there is no such restriction on intravenously delivered drugs. Therefore, minimization of membrane diffusion in the context of an intravenously agent should ensure optimal hepatic targeting and therapeutic index. This work details the identification a hepatoselective GKA exhibiting the aforementioned properties. 相似文献