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991.
Sun Jin Kim Myung Hun Kim Gon Seo Young Sun Uh 《Research on Chemical Intermediates》2012,38(6):1181-1190
Vapor phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam has been carried out using tantalum-pillared magadiites
(Ta-magadiites) with different surface areas as catalysts. The Ta-magadiite catalysts of relatively large surface areas showed
high catalytic activities, due to a large number of active sites. For the Ta-magadiite catalyst of the largest surface area,
the oxime conversion reached 99.1%, with 97.5% of lactam selectivity. FT-IR and NH3-TPD results demonstrated that the new hydroxyl groups and a large amount of acidic sites generated by Ta pillaring into the
magadiite interlayer were responsible for the high catalytic performance of Ta-magadiite catalyst. 相似文献
992.
DNA Block Copolymer Doing It All: From Selection to Self‐Assembly of Semiconducting Carbon Nanotubes
Minseok Kwak Jia Gao Deepak K. Prusty Andrew J. Musser Vladimir A. Markov Nikolaos Tombros Marc C. A. Stuart Wesley R. Browne Egbert J. Boekema Gerrit tenBrinke Harry T. Jonkman Bart J. vanWees Maria A. Loi Andreas Herrmann 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2011,123(14):3264-3268
993.
Yungwan Kwak Robert T. Mathers Krzysztof Matyjaszewski 《Macromolecular rapid communications》2012,33(1):80-86
Critical evaluations of the microwave effect on initiation, propagation, and termination during conventional radical polymerizations (RPs) of methyl methacrylate (MMA) and random copolymerization of styrene (St) with (meth)acrylates are examined by comparing microwave heating (MWH) and conventional heating (CH). Poly(methyl methacrylate) with similar , / , and conversion are obtained under precisely controlled temperature, indicating very small changes of propagation rate constant. Rate enhancement in the absence of precise temperature control is mostly due to the higher reaction temperature of the reaction mixture than the apparent value indicated on display. Rates of initiator decomposition under well‐controlled temperature are essentially the same for MWH and CH. 相似文献
994.
Dendroaspis natriuretic peptide (DNP), a new member of the natriuretic peptide family, is structurally similar to atrial, brain, and C-type natriuretic peptides. However, the effects of DNP on the cardiac function are poorly defined. In the present study, we examined the effect of DNP on the cardiac L-type Ca(2+) channels in rabbit ventricular myocytes. DNP inhibited the L-type Ca(2+) current (I(Ca,L)) in a concentration dependent manner with a IC(50) of 25.5 nM, which was blocked by an inhibitor of protein kinase G (PKG), KT5823 (1 μM). DNP did not affect the voltage dependence of activation and inactivation of I(Ca,L). The α(1c) subunit of cardiac L-type Ca(2+) channel proteins was phosphorylated by the treatment of DNP (1 μM), which was completely blocked by KT5823 (1 μM). Finally, DNP also caused the shortening of action potential duration in rabbit ventricular tissue by 22.3 ± 4.2% of the control (n = 6), which was completely blocked by KT5823 (1 μM). These results clearly indicate that DNP inhibits the L-type Ca(2+) channel activity by phosphorylating the Ca(2+) channel protein via PKG activation. 相似文献
995.
Kyoung Soo Kim Da Hee Oh Jung Yeon Kim Bong Gn Lee Jeong Soon You Kyung Ja Chang Hyunju Chung Myung Chul Yoo Hyung-In Yang Ja-Heon Kang Yoo Chul Hwang Kue Jeong Ahn Ho-Yeon Chung In-Kyung Jeong 《Experimental & molecular medicine》2012,44(11):665-673
This study aimed to determine whether taurine supplementation improves metabolic disturbances and diabetic complications in an animal model for type 2 diabetes. We investigated whether taurine has therapeutic effects on glucose metabolism, lipid metabolism, and diabetic complications in Otsuka Long-Evans Tokushima fatty (OLETF) rats with long-term duration of diabetes. Fourteen 50-week-old OLETF rats with chronic diabetes were fed a diet supplemented with taurine (2%) or a non-supplemented control diet for 12 weeks. Taurine reduced blood glucose levels over 12 weeks, and improved OGTT outcomes at 6 weeks after taurine supplementation, in OLETF rats. Taurine significantly reduced insulin resistance but did not improve β-cell function or islet mass. After 12 weeks, taurine significantly decreased serum levels of lipids such as triglyceride, cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol. Taurine significantly reduced serum leptin, but not adiponectin levels. However, taurine had no therapeutic effect on damaged tissues. Taurine ameliorated hyperglycemia and dyslipidemia, at least in part, by improving insulin sensitivity and leptin modulation in OLETF rats with long-term diabetes. Additional study is needed to investigate whether taurine has the same beneficial effects in human diabetic patients. 相似文献
996.
997.
We develop a criterion for a normal basis (Theorem 2.4), and prove that the singular values of certain Siegel functions form normal bases of ray class fields over imaginary quadratic fields other than ${\mathbb{Q}(\sqrt{-1})}$ and ${\mathbb{Q}(\sqrt{-3})}$ (Theorem 4.2). This result would be an answer for the Lang-Schertz conjecture on a ray class field with modulus generated by an integer (≥2) (Remark 4.3). 相似文献
998.
999.
In this paper we give some characterizations of a ring Rwhose unique maximal nil ideal N r (R) coincides with the set of all its nilpotent elements N(R) by using its minimal strongly prime ideals. 相似文献
1000.
Mason introduced the reflexive property for ideals, and then this concept was generalized by Kim and Baik, defining idempotent reflexive right ideals and rings. In this article, we characterize aspects of the reflexive and one-sided idempotent reflexive properties, showing that the concept of idempotent reflexive ring is not left-right symmetric. It is proved that a (right idempotent) reflexive ring which is not semiprime (resp., reflexive), can always be constructed from any semiprime (resp., reflexive) ring. It is also proved that the reflexive condition is Morita invariant and that the right quotient ring of a reflexive ring is reflexive. It is shown that both the polynomial ring and the power series ring over a reflexive ring are idempotent reflexive. We obtain additionally that the semiprimeness, reflexive property and one-sided idempotent reflexive property of a ring coincide for right principally quasi-Baer rings. 相似文献