牛磺酸与噻吩甲醛缩合形成Schiff碱反应机理的研究

用密度泛函理论(B3LYP)在6-31G**基组水平上, 对牛磺酸与噻吩甲醛缩合生成Schiff碱的反应机理进行了模拟计算, 并利用计算结果按过渡状态理论计算出反应的速率常数. 分析了质子传递介质对这类反应的催化作用原理. 研究结果对于伯胺与活性羰基化合物缩合的一类反应机理的深入研究, 以及对于与Schiff碱的生成与分解有关的生化过程的进一步探讨都有一定意义.     

Production of recoil ions He^i＋ accompanied by single electron loss of 0.2-7 MeV C^q＋ and 0.25-5 MeV O^q＋ （q = 1- 4） ions

Target ionization accompanied with projectile electron loss is investigated for 0.2-7 MeV C^q＋ （q = 1 - 4） with He and 0.25-5 MeV O^q＋ （q = 1 - 4） with He collisions. For projectile single-electron loss channel, the He double-to-single ionization ratio R is nearly independent of projectile charge state but dependent on the nuclear charge of projectile Zp. The results are analysed with atomic structure qualitatively. So far there have not existed the experimental data comparable with our results, to our knowledge. The ratio R is interpreted in terms of the two-step mechanism. This analysis agrees well with similar experiments in the literature.     

基于固定化酶的化学发光停流法测定D-氨基酸

基于固定化酶的化学发光停流法测定Ｄ－氨基酸封满良,黄玉文,宫志龙,章竹君（陕西师范大学化学系,西安,７１００６２）关键词固定化酶,化学发光,甲壳质,Ｄ－氨基酸自从发现人体有关组织及血桨中Ｄ－氨基酸的水平与某些疾病有关以来,已报道了许多测定Ｄ－氨基酸的...     

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.     

原位合成钴/还原氧化石墨烯纳米粒子催化氨硼烷制氢

采用简单的原位还原合成方法,利用具有温和还原性能的氨硼烷作为还原剂,在室温下一步还原氧化石墨烯和氯化钴混合溶液制备了还原氧化石墨烯负载钴纳米复合材料催化剂. 利用所制备的钴/还原氧化石墨烯催化剂催化氨硼烷水解制氢,发现钴/还原氧化石墨烯具有优异的催化性能. 相对于没有负载的钴纳米粒子以及采用硼氢化钠作为还原剂制备的钴/还原氧化石墨烯催化剂,采用氨硼烷还原制备的钴/还原氧化石墨烯催化剂表现出更加优越的催化性能. 动力学测试表明,钴/还原氧化石墨烯催化氨硼烷水解反应为零级反应,同时钴/还原氧化石墨烯催化剂催化氨硼烷水解反应的活化能为27.10 kJ·mol^-1,低于大部分已报道的其它催化剂,甚至一些贵金属催化剂的活化能. 钴/还原氧化石墨烯催化剂有着稳定的循环使用性,特别是其具有的磁性使得它能够直接从溶液中通过磁力回收,极具应用前景. 这种简单有效的合成方法有望推广到其它的金属-还原氧化石墨烯纳米复合材料体系.     

The HDAC/HSP90 Inhibitor G570 Attenuated Blue Light-Induced Cell Migration in RPE Cells and Neovascularization in Mice through Decreased VEGF Production

Age-related macular degeneration (AMD) occurs due to an abnormality of retinal pigment epithelium (RPE) cells that leads to gradual degeneration of the macula. Currently, AMD drug pipelines are endowed with limited options, and anti-VEGF agents stand as the dominantly employed therapy. Despite the proven efficacy of such agents, the evidenced side effects associated with their use underscore the need to elucidate other mechanisms involved and identify additional molecular targets for the sake of therapy improvement. The previous literature provided us with a solid rationale to preliminarily explore the potential of selective HDAC6 and HSP90 inhibitors to treat wet AMD. Rather than furnishing single-target agents (either HDAC6 or HSP90 inhibitor), this study recruited scaffolds endowed with the ability to concomitantly modulate both targets (HDAC6 and HSP90) for exploration. This plan was anticipated to accomplish the important goal of extracting amplified benefits via dual inhibition (HDAC6/HSP90) in wet AMD. As a result, G570 (indoline-based hydroxamate), a dual selective HDAC6-HSP90 inhibitor exerting its effects at micromolar concentrations, was pinpointed in the present endeavor to attenuate blue light-induced cell migration and retinal neovascularization by inhibiting VEGF production. In addition to the identification of a potential chemical tool (G570), the outcome of this study validates the candidate HDAC6-HSP90 as a compelling target for the development of futuristic therapeutics for wet AMD.     

Spin-gap phase in the extended t — J chain

The European Physical Journal B - We study the one-dimensional deformed t - t ′ - J model in terms of the continuum field theories. We found that at low doping concentration and far away from...     

Effects of Inert Particles on Liquid Phase Hydrogenation Over Nano-sized Catalysts

The effects of inert particles on the liquid hydrogenation over nano-sized Ni–B catalysts were investigated in a batch reactor. Nitrobenzene hydrogenation was used as a test reaction. The effects of stirring speed and the dispersant/catalysts ratio were investigated. Addition of inert particle in the reaction system of nano-catalysts could increase the reaction conversion significantly. The reaction conversion increased with increasing stirring speeding until 900-rpm, and then decreased. The addition of inert particle to the reaction system could prevent the agglomeration of nano-metals and disperse them over the entire reaction system. Nano-metals were physically attached on the external surface of the inert particles. In addition, the addition of inert particle may enhance the absorption rate of hydrogen in solvent, and resulting in the increase of reaction rate. Both are beneficial to the reaction conversion. The enhancement effect of Al₂O₃ is much greater than that of SiO₂.