复合萃取剂醋酸乙二醛液液相平衡研究

研究了复合萃取剂醋酸乙二醛三元体系在 2 5℃时的液液相平衡关系 ,通过自动电位滴定仪测定了两平衡相中醋酸的含量 ,用浑浊法测定了体系的分层曲线 ,并绘出了三元相图。从三元相图看 ,复合萃取剂具有良好的萃取性能。     

Thymidine kinase gene mutation leads to reduced virulence of pseudorabies virus

To explore correlation between the tk gene structure of pseudorabies virus (PRV) and its virulence, to study the effect of the gene mutation on PRV biological properties, and to investigate mechinism of reduced virulence, thymidine kinase (TK)-deficient mutant of pseudorabies virus strain Hubei (PRV HB) was isolated by selection for resistance to 5-bromodeoxyuridine. The tk genes of PRV HB and its TK^― mutant were cloned and sequenced. 1587 base pairs of the tk gene and flanking regions of wild-type (wt) virus were sequenced, which included an open reading frame (ORF) of 1098 bp encoding a protein of 366 amino acids. The ORF contained two 137-bp repeated sequences, which were connected by an adenosine. 1458 bp of the tk and flanking regions of TK^― mutant were sequenced. Analysis of the tk gene sequence of TK^― mutant indicated that one of 137 bp repeated sequence and the connecting adenosine in the tk gene of the wt virus was deleted and a repeated sequence of 8 nucleotides (GCGCGCC) was inserted. All other nucleotides of TK^―mutant were identical to that of wt virus. Deletion and insertion of the nucleotide sequence resulted in a frameshift and a premature chain termination, and the resultant TK protein was not active. Analysis of the amino acid sequence revealed that TK protein of PRV HB contained the conserved consensus sequence of herpesviral TKs and an additional conserved-DHR-motif. The results of this work also indicated that TK^― mutant was genetically stable. Compared to PRV HB, virulence of TK^― mutant was greatly decreased. Mice vaccinated with TK^― mutant were completely protected against a lethal challenge with virulent PRV (HB).     

6,7-dichlorobenzo[de]isochromene-1,3-dione的合成新方法

本文报道了6,7-dichlorobenzo[de]isochromene-1,3-dione的合成新方法。该路线简单易行,后处理方便,且产率较高,有较高的实用价值。     

恶性肿瘤骨转移性骨痛的放射性核素治疗概况

综述了^32P,^89Sr,^153Sm等放射性核素治疗骨转移癌骨痛的机制，疗效和副作用，是一种有效的治疗方法。     

Cholinergic, monoaminergic and glutamatergic changes following perinatal asphyxia in the rat

Perinatal asphyxia (PA) is considered to lead to a variety of brain disorders including spasticity, epilepsy, mental retardation, and minimal brain disorder syndromes and may form the basis for psychiatric and neurodegenerative diseases later in life. We examined markers for neuronal transmission involved in the pathomechanisms of PA and candidates as mediators for long-term sequelae. We tested tyrosine hydroxylase (TH) and the vesicular monoamine transporter (VMAT) representing the monoaminergic system, the vesicular acetylcholine transporter (VAChT), and the excitatory amino acid carrier 1 (EAAC1), a neuronal subtype of the glutamate transporter, using immunohistochemistry on brain sections of rats subjected to graded PA. Three months following the asphyxiant insult immunoreactive (IR)-TH was decreased in striatum, hippocampus, thalamus, frontal cortex, and cerebellum; IR-VMAT was increased, and IR-VAChT was decreased in striatum. IR-EAAC1 glutamate transporter was increased in frontal cortex. The cholinergic, monoaminergic, and glutamatergic changes, still observed 3 months after the asphyxiant insult, may reflect their involvement in the pathomechanisms of PA and indicate mechanisms leading to long-term complications of PA. The variable consequences on the individual markers in several brain regions may be explained by specific susceptibility of cholinergic, monoaminergic, and glutamatergic neurons to the asphyxiant insult. Received 16 March 1999; received after revision 20 May 1999; accepted 8 July 1999     

Role of the δ 8 double bond of agroclavine in lysergic acid amide biosynthesis byClaviceps purpurea

Summary Agroclavine, given to actively-growing sclerotial tissue of a strain ofClaviceps purpurea which can not normally elaborate ergot alkaloids, was transformed by this tissue into lysergic acid amide with overall efficiency of approximataly 40%. By contrast, festuclavine (8, 9-dihydro-agroclavine) was not transformed, indicating specificity in the mechanism of lysergyl biosynthesis.     

反式蒈醛酸酯经差向异构化制取半缩醛内酯的研究

反式菊酸酯经臭氧化得蒈醛酸酯,然后在甲醇钠的甲醇溶液中发生差向异构,获得顺式蒈醛酸及它的半缩醛内酯的混合物,收率从原来文献报导的27％提高到60％。     

12—硅钼酸降解产物SiMo11铵盐的合成

在对SiMo_(12)杂多酸降解过程的研究中,首次从H_4SiMo_(12)O_(40)直接降解合成出其降解产物(NH_4)_8[SiMo_(11)O_(39)]·14H_2O。经组成分析,确认其为SiMo_(11)铵盐。利用紫外光谱分析、红外光谱分析、x射线粉末衍射、电位滴定、tga—dta热分析、薄板层析等现代分析手段对合成产物的性质进行了研究。     

Cerebral ischemia revisited: New insights as revealed using in vitro brain slice preparations

Summary The elucidation of the pathophysiological mechanisms of cerebral ischemia/hypoxia dictates the use of experimental models which mimic this disabling brain condition. In vivo experimental models have been available for many decades and are responsible for the bulk of, though incomplete, knowledge we have about these mechanisms. Since study in isolation of each postulated mechanism is impossible in vivo, the need for an in vitro experimental model has intensified in recent years. Consequently, rat and guinea pig hippocampal slice preparations have emerged as the models of choice. This review attempts to highlight some of the results obtained using brain slices in the study of cerebral ischemia/hypoxia and compare them to those obtained in vivo. Both the biochemical and the physiological correlates of energy metabolism, ion homeostasis, neurotransmission and neuromodulation of this brain condition are reviewed. The agreements, and especially the disagreements, between the in vivo and in vitro findings are emphasized. Details are given of the possible roles of both lactic acid, Ca²⁺ and excitotoxins in the neuronal damage inflicted by cerebral ischemia/hypoxia. Recent attempts to protect brain slices against experimental cerebral ischemic/hypoxic damage are also reviewed here briefly.     

绿色含硼加脂剂的制备与性能

将蓖麻油进行硼酸酯化,用氢氧化钠和三乙醇胺中和制备了一种绿色硼酸酯阴离子型皮革加脂剂,讨论了反应物料配比、反应温度、催化剂用量和中和方式对加脂剂稳定性及加脂性能的影响。结果表明当蓖麻油与硼酸的质量比为(3.0~4.0):1、催化剂用量为反应物质量的2%、反应温度为80~85℃时,制得的加脂剂具有良好的润滑性、稳定性,加脂效果与传统的磷酸化蓖麻油相当。工艺环境友好,简使易行。