Fe2(SO4)3/K2S2O8催化合成乳酸正丁酯的研究

以Fe2(SO4)3和K2S2O8为复配催化剂，对乳酸和正丁醇为原料合成乳酸正丁酯的反应进行了研究，探讨了催化剂用量、酸醇摩尔比、反应时间等对酯化反应的影响．结果表明：酸醇物质的量之比1：3，催化剂1．6g，带水剂苯5．0ml，反应时间2．0h，减压蒸馏，收集80～82℃／1．8KPa的馏份，酯化产率达93．2％。     

壳聚糖类植物保养剂对玉米根生理作用初探

使用不同浓度的壳聚糖、羧甲基壳聚糖及因子A对玉米进行浸种实验，发现适当浓度的壳聚糖类物质及因子A单独及复合均可提高苗期玉米根的重量、吸收面积和脱氢酶活性。其提高作用随壳聚糖及其衍生物和因子A等不同和浓度变化而不同。在单因子实验中，0．01％～0．025％的壳聚糖类物质和0．001％的因子A对玉米根活力有较好的促进作用。在单因子实验结果基础上初步形成了“复方植物保养剂”的几种不同配方，并对该配方进行实验，得到比单纯壳聚糖类物质及因子A促进效果更好的最佳配方为0．001％因子A加上0．01％的壳聚糖和0．01％的脱乙羧基壳聚糖，其可提高玉米根干重的61．1％，活跃吸收面积的37．20％和脱氢酶的80．82％。     

固体酸催化合成乳酸正丁酯

评述了对甲苯磺酸、氨基磺酸、强酸性阳离子交换树脂、磺化聚氯乙烯树脂、六水三氯化铁、聚氯乙烯三氯化铁树脂、氯化聚氯乙烯三氯化铁树脂、十二水合硫酸铁铵、一水合硫酸氢钠、树脂负载三氯化铝、稀土化合物、固体超强酸、杂多酸、沸石分子筛和维生素C等催化剂催化合成乳酸正丁酯的方法 .     

葡萄糖-6-磷酸脱氢酶的分离纯化

报道了葡萄糖-6-磷酸脱氢酶的分离纯化. 在0.1 mol/L的碳酸氢钠溶液中,以溶胀法从酵母中提取胞内酶.粗抽提液经过60 %～75 % 饱和度的硫酸铵盐析, Sephadex G-100凝胶柱层析.葡萄糖-6-磷酸脱氢酶的收得率为12.4%,纯化倍数达51.2.     

乳酸能系统在100m跑中的代谢特征研究

通过对30名不同水平的体育系学生100m跑和不同段落重复跑后的血乳酸测定。发现不同水平受试者100m跑后都存在着不同程度的血乳酸堆积，且受试者的训练水平对血乳酸值有显著影响．不同段落重复跑后的血乳酸值在随跑距延长而逐渐升高的过程中，存在着一个急剧升高的阶段，因此。乳酸能系统在100m跑中发挥着重要的作用．     

水稻苹果酸脱氢酶基因的克隆及其在E.coli中的表达

以玉米苹果酸脱氢酶的基因为探针，从水稻幼苗cDNA文库筛选得到一条水稻新基因，它与玉米ZHO2序列的一致性高达87％，被命名为RcMDH(rice cytoplasmic malic dehydrogenase gene)，分析发现RcMDH具有完整的读码框，编码332个氨基酸，预计分子质量为36．5ku,导入大肠杆菌中表达，经检测证实该产物具苹果酸脱氢酶酶活性。     

Synthesis and mesomorphic properties of new compounds exhibiting TGBA and TGBC liquid crystalline phases

We synthesised a series of rod-like mesogens with a (S)-2-methylbutyl-(S)-lactate unit in the chiral chain that exhibited extremely wide temperature ranges in the TGBA and TGBC* phases. TGB phases were identified, based on typical textures in confined samples and in free-standing films, by Grandjean-Cano texture and by NMR studies on a deuterium-labelled isotopomer. A sufficiently high electric or magnetic field transformed the TGBA and TGBC* phases into their respective SmA and SmC* phases, the TGB structures being restored within some 20-30 minutes. Therefore values of the spontaneous polarisation and spontaneous tilt angle, when measured under a sufficiently high field, gave evidence of the properties of the SmC* phase. Temperature dependencies of relaxation frequency, dielectric strength, selective reflection and layer spacing showed anomalies at a certain temperature within the TGBC* phase range. Also, changes in textures, as well as in ²H-NMR spectra, occurred at this same temperature. These results suggest the existence of two TGBC* phases.     

运动训练对决定长跑运动成绩的生理因素的影响

长距离跑运动训练目前普遍采用的方法主要来自于运动员试错和一些杰出教练员的经验总结。适宜的方法可能有利于提高长跑运动员最大摄氧量、乳酸阈和运动经济性。研究结果表明大强度运动和抗阻力训练可能十分有效,但研究存在较大的局限性。其中,最重要的原因缺少相关的长期实验研究。分子生物学的相关研究可能为选择这些适宜的训练方法提供帮助。通过发现和最大摄氧量、乳酸阈和运动经济性能力相关的基因,探讨其中生化和机械的信号通路等。     

腹部大手术后动脉血乳酸水平对临床结果的影响

目的:研究腹部大手术后动脉血乳酸水平对临床结果的影响.方法:对2007年2月～2009年2月所有进行腹部大手术的421例病例进行前瞻性对比研究,统计所有病人的初始、第24小时、第48小时乳酸值及清除时间,并发症及死亡情况.结果:并发症组及死亡组术后不同时间血乳酸水平均高于无并发症组(P<0.001);术后乳酸值24小时正常组、24～48小时正常组、48小时后正常组及术后乳酸一直未正常组并发症发生率分别为13%、39%、65%和100%.结论:动脉血乳酸水平可预测腹部大手术后并发症发生率及死亡率.     

Anisotropic Orientation of Lactate in Skeletal Muscle Observed by Dipolar Coupling in H NMR Spectroscopy

Double quantum (DQ), J-resolved (1)H NMR spectra from rat and bovine skeletal muscle showed a splitting frequency ( approximately 24 Hz) for the lactate methyl protons that varied with the orientation of the muscle fibers relative to the magnetic field. In contrast, spectra of lactate in solution consist of a J-coupled methyl doublet and a J-coupled methine quartet (J(HH) = 7 Hz) with no sensitivity to sample orientation. Spectra acquired in magnetic fields of 4.7, 7, and 11 T showed that the splitting was not due to inhomogeneities in magnetic susceptibility within the muscle, because the magnitude of the splitting did not scale with the strength of B(0) fields. Triple quantum coherence (TQC) spectra revealed two distinct transition frequencies on the methyl resonance. These frequencies resulted from intra-methyl and methine-methyl couplings in this four spin system (A(3)X). Decoupling experiments on the triple quantum coherence showed that the observed frequency splitting was due mainly to the dipolar interactions between the methine and methyl protons of the lactate molecule. Thus, all the proton resonances of the lactate molecules in muscle behave anisotropically in the magnetic field. Adequate design and interpretation of spectroscopic experiments to measure lactate in muscle, and possibly in any cell and organ which contain asymmetric structures, require that both the dipolar coupling described here and the well-known scalar coupling be taken into account.