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71.
72.
本文叙述了组合化学技术的研究与应用,包括诸如同步多重合成(混合固相合成)法、多头合成(多针合成)法、茶袋法、光印(光控合成)法、反应珠法、载体合成法、基因重组法、非肽类岸法、色谱条码法等及其检测方法。它们已成为寻找和发展分子多样性与研究开发新药的策略和途径。  相似文献   
73.
研究了用疏水膨胀床直接从未澄清酵母(S.cerevisiae)均化液中分离L-天门冬氨酸酶的过程.吸附和冲洗采用膨胀床模式,而酶的洗提采用沉降床模式.在适当的疏水条件下,膨胀床中的疏水吸附剂(TskgelPhenyl_Toyopearl650C)可从未澄清均化液中直接捕集分离L-天门冬氨酸酶.通过梯度洗提,一次膨胀床吸附过程中,酶活的洗脱率为95%,均化液中酶的总回收率为65%,洗脱液纯度为13倍.本方法将膨胀床和疏水性吸附的特长有机地结合起来,是生物活性蛋白酶分离纯化的一个重要手段.  相似文献   
74.
模拟退火(SA)系寻找全局最优并能跨越局部最优的随机优化算法,它源于对高温物质的退火过程几近平衡的统计力学模拟,SA算法及随机抽样,通用模拟退火(GSA)法可用于多元校正。本文结合紫外先请将SA与GSA用于维生素多组分分析,获得良好效果。  相似文献   
75.
Summary -Fluoroaspartic acid, a new amino acid, was synthesized by a diazotization of diaminosuccinic acid in liquid hydrogen fluoride.Synthesis of Amino Acids and Related Compounds, part 21.—Part 20: Y. Ozaki, S. Maeda, M. Miyoshi and K. Matsumoto, Synthesis, 216 (1979).We would like to acknowledge Dr I. Chibata for his encouragement in this work.  相似文献   
76.
Summary Synephrine (SP) was found to be a substrate for monoamine oxidase (MAO) in rat brain mitochondria, showing the Km and Vmax values of 250 M and 32.6 nmoles/mg of protein/30 min respectively. The inhibition studies showed that the SP oxidation was carried out by both type A and type B MAO and a major part of the activity was due to type A MAO.  相似文献   
77.
Adolescent idiopathic scoliosis is a pediatric spinal deformity affecting 2-3% of school-age children worldwide(1). Genetic factors have been implicated in its etiology(2). Through a genome-wide association study (GWAS) and replication study involving a total of 1,376 Japanese females with adolescent idiopathic scoliosis and 11,297 female controls, we identified a locus at chromosome 10q24.31 associated with adolescent idiopathic scoliosis susceptibility. The most significant SNP (rs11190870; combined P = 1.24 × 10(-19); odds ratio (OR) = 1.56) is located near LBX1 (encoding ladybird homeobox 1). The identification of this susceptibility locus provides new insights into the pathogenesis of adolescent idiopathic scoliosis.  相似文献   
78.
A novel chlorinated steroid, aragusterol C, was isolated from an Okinawan marine sponge of the genusXestospongia. The compound strongly inhibited the proliferation of KB cells in vitro, and also showed potent in vivo antitumor activity against L1210 cells in mice. The complete structure of aragusterol C was determined by spectroscopic analysis and X-ray crystallographic analysis.  相似文献   
79.
The sequence of 5,037 amino acids composing the ryanodine receptor from rabbit skeletal muscle sarcoplasmic reticulum has been deduced by cloning and sequencing the complementary DNA. The predicted structure suggests that the calcium release channel activity resides in the C-terminal region of the receptor molecule, whereas the remaining portion constitutes the 'foot' structure spanning the junctional gap between the sarcoplasmic reticulum and the transverse tubule.  相似文献   
80.
Matsumoto M  Hikosaka O 《Nature》2007,447(7148):1111-1115
Midbrain dopamine neurons are key components of the brain's reward system, which is thought to guide reward-seeking behaviours. Although recent studies have shown how dopamine neurons respond to rewards and sensory stimuli predicting reward, it is unclear which parts of the brain provide dopamine neurons with signals necessary for these actions. Here we show that the primate lateral habenula, part of the structure called the epithalamus, is a major candidate for a source of negative reward-related signals in dopamine neurons. We recorded the activity of habenula neurons and dopamine neurons while rhesus monkeys were performing a visually guided saccade task with positionally biased reward outcomes. Many habenula neurons were excited by a no-reward-predicting target and inhibited by a reward-predicting target. In contrast, dopamine neurons were excited and inhibited by reward-predicting and no-reward-predicting targets, respectively. Each time the rewarded and unrewarded positions were reversed, both habenula and dopamine neurons reversed their responses as the bias in saccade latency reversed. In unrewarded trials, the excitation of habenula neurons started earlier than the inhibition of dopamine neurons. Furthermore, weak electrical stimulation of the lateral habenula elicited strong inhibitions in dopamine neurons. These results suggest that the inhibitory input from the lateral habenula plays an important role in determining the reward-related activity of dopamine neurons.  相似文献   
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