Synthesis and Characterization of (+)-α-Phenylethanammonium Phosphotungstate and Its Catalytic Performance for Asymmetric Epoxidation

以Keggin型12-磷钨酸和(+)-α-苯乙胺为原料,通过水热法合成了具有Keggin结构的(+)-α-苯乙胺磷钨酸盐(C8H12-N)3PW12O40.通过红外光谱、核磁共振波谱、紫外光谱、元素分析和热重分析等技术对合成产物进行了结构、组成和热稳定性的表征和考察,证实了合成产物为(+)-α-苯乙胺磷钨酸盐.以顺丙烯磷酸-α-苯乙胺盐环氧化合成(1R,2S)-环氧丙基磷酸-α-苯乙胺盐为探针反应,考察了(C8H12N)3PW12O40催化不对称环氧化性能.结果表明,在催化剂用量为2.00%和反应温度为50℃时,产物环氧丙基磷酸苯乙胺盐的收率为64%,(1R,2S)-环氧丙基磷酸苯乙胺盐的对映选择性ee值为10.8%.A(+)-α-phenylethanammonium phosphotungstate(C8H12N)3PW12O40 was synthesized by a mild hydrothermal technique and its structure was characterized by infrared spectroscopy,nuclear magnetic resonance,ultraviolet spectroscopy,elemental analysis,and thermogravimetry.A probe reaction of the epoxidation of(±)-α-phenylethanammonium-cis-1-propenylphosphonate into α-phenylethanammonium-cis-1,2-epoxypropyl phosphonate was carried out to investigate the catalytic performance of(C8H12N)3P-W12O40.A yield of 64% of epoxide and ee of 10.8% of α-phenylethanammonium-cis-(1R,2S)-epoxypropyl phosphonate were obtained with 2% catalyst at temperature 50 ℃.河南省杰出人才创新基金(0221001200

股骨髁上简单骨折随愈合时期变化的负重能力研究

股骨远端骨折稳定性差、并发症多,目前多主张进行积极的手术治疗。术后的早期康复训练有助于促进骨折愈合,但大多基于临床医生经验,缺乏客观指导。本文通过影像学数据获得了股骨的三维几何模型,建立了使用锁定板固定的股骨髁上简单骨折模型,研究了股骨在单腿站立姿态下,不同愈合时期骨折固定模型的应力分布和传递机制。结果表明:骨折固定模型的应力分布状态受骨折方向和愈合时期的影响,例如锁定板的最大Mises应力在相邻两个愈合期最高相差70%。文章以锁定板系统失效为标准,给出了股骨髁上简单骨折早期承载能力的半定量指标,表明了患者需要针对骨折方向和愈合时期及时调整术后负重大小,对临床康复训练有指导意义

束缚和异氟烷麻醉对大鼠心率变异性及HPA轴影响的比较

目的为了观察束缚固定和异氟烷(流量:0.8 L,浓度:1.5%)麻醉状态中大鼠的心率变异性的变化;并通过比较9天每天30 min束缚干预和异氟烷麻醉对大鼠的体重、痛阈以及与HPA轴相关激素的影响,来评估长期使用异氟烷麻醉和束缚固定对大鼠应激程度的影响,选择更适宜的大鼠固定方法,为基础医学的实验方法提供重要的参考。方法 SD大鼠随机分为3组:空白组,束缚组,异氟烷麻醉组。急性实验通过记录大鼠心电图15 min,观察束缚固定和异氟烷麻醉情况下大鼠心率,心率变异性的变化。慢性实验中比较连续干预9天(30 min/d)前后3组大鼠体重、痛阈变化以及与应激状态相关激素含量的变化。结果 1)急性试验:与空白组大鼠相比,束缚干预和异氟烷麻醉均造成大鼠心率显著增加,具有统计学意义(P 0.05)。结论以上结果提示:低浓度的异氟烷造成麻醉中大鼠心率增加,心率变异性下降,产生以交感兴奋为主的自主神经功能状态改变。多次束缚固定易造成大鼠HPA轴激活,产生慢性应激的效应。在长期需要固定动物的实验中,与束缚固定相比异氟烷麻醉是更好的固定方法。国家自然科学基金(81674083

Synthesis and Characterization of (+)-alpha-Phenylethanammonium Phosphotungstate and Its Catalytic Performance for Asymmetric Epoxidation

A ( + )-alpha-phenylethanammonium phosphotungstate (C8H12N)(3)PW12O40 was synthesized by a mild hydrothermal technique and its structure was characterized by infrared spectroscopy, nuclear magnetic resonance, ultraviolet spectroscopy, elemental analysis, and thermogravimetry. A probe reaction of the epoxidation of ( +/- ) -alpha-phenylethanammonium-cis-1-propenylphosphonate into alpha-phenylethanammoniuni- cis -1, 2-cpoxypropyl phosphonate was carried out to investigate the catalytic performance of (C8H12N)(3)PW12O40. A yield of 64% of epoxide and ee of 10.8% of alpha-phenylethanammonium-cis-(1R, 2S)-epoxypropyl phosphonate were obtained with 2% catalyst at temperature 50 degrees C

Selectivity of biopolymer membranes using HepG2 cells

Bioartificial liver (BAL) system has emerged as an alternative treatment to bridge acute liver failure to either liver transplantation or liver regeneration. One of the main reasons that the efficacy of the current BAL systems was not convincing in clinical trials is attributed to the lack of friendly interface between the membrane and the hepatocytes in liver bioreactor, the core unit of BAL system. Here, we systematically compared the biological responses of hepatosarcoma HepG2 cells seeded on eight, commercially available biocompatible membranes made of acetyl cellulose&ndash;nitrocellulose mixed cellulose (CA&ndash;NC), acetyl cellulose (CA), nylon (JN), polypropylene (PP), nitrocellulose (NC), polyvinylidene fluoride (PVDF), polycarbonate (PC) and polytetrafluoroethylene (PTFE). Physicochemical analysis and mechanical tests indicated that CA, JN and PP membranes yield high adhesivity and reasonable compressive and/or tensile features with friendly surface topography for cell seeding. Cells prefer to adhere on CA, JN, PP or PTFE membranes with high proliferation rate in spheriod-like shape. Actin, albumin and cytokeratin 18 expressions are favorable for cells on CA or PP membrane, whereas protein filtration is consistent among all the eight membranes. These results further the understandings of cell growth, morphology and spreading, as well as protein filtration on distinct membranes in designing a liver bioreactor.</p

助剂对低碳醇合成熔铁催化剂的影响

用ＸＲＤ，ＴＧ－ＤＴＡ－ＤＴＧ和ＣＯ加氢反应装置，对某些难熔氧化物助剂改性的熔铁催化剂的结构、还原和合成醇活性、选择性进行了研究。结果表明，催化剂的氧化态物相主要是Ｆｅ３Ｏ４，难熔氧化物助剂的加入可使还原温度提高。Ｖ２Ｏ５助剂有利于提高低温催化活性和Ｃ２＾＋ＯＨ选择性，Ｃｒ２Ｏ３助剂对提高高温活性有利。ＴｉＯ２助剂的最佳含量约为２．５％。当采用复合助剂时，不仅可提高催化活性和选择性，而且可降低催

地源热泵在酒店供冷供热系统中的应用及经济性能分析

本文介绍了用于替代锅炉为酒店提供生活热水，同时提供空调用冷冻水的地源热泵系统性能、特点，并与燃油锅炉供热系统的经济性进行了分析比较