养阴通脑颗粒中黄酮对脑缺血再灌注损伤保护作用的实验研究

为了进一步探讨养阴通脑颗粒中有效成分治疗缺血性脑血管病的作用及其作用机理.我们开展了黄酮对大鼠脑缺血再灌注损伤保护作用研究.现将其对脑缺血再灌注损伤大鼠抗凝、纤溶等指标的影响报告如下.     

调节肽在休克发病中的作用

本文探讨了三种调节肽在休克发病中的作用。结果表明:(1)败血症休克大鼠血浆内皮素(ET)成倍增加,给健康大鼠持续滴注低剂量ET可致明显的休克表现,而给轻度失血休克大鼠静滴ET,则致休克不可逆,用特异的ET-抗血清治疗休克,具有明显疗效;(2)败血症休克大鼠血浆降钙素基因相关肽(CGRP)增加2.6倍,休克早期或晚期运用低剂量CGRP治疗都具有显著疗效;(3)休克大鼠心肌、主动脉组织血管紧张素Ⅱ明显增加,休克早期抑制其增加可加剧休克,晚期抑制其升高则具有显著疗效.结论认为,ET是参与休克发病的重要体液因素,CGRP参与休克时机体的代偿调节,组织血管紧张素Ⅱ在休克不同时期作用不同。     

一锅法合成开链片螺素-吡咯异喹啉羧酸乙酯

片螺素(Lamellarins)是一类从海洋软体动物中提取的具有良好生物活性的吡咯类生物碱.自1985年,Faulkner等首次从前腮亚纲软体动物中提取出片螺素A-D[1]后,国内外便开始对各类片螺素及其衍生物的全合成进行研究,至今相关合成报道络绎不绝[2][3].与此同时多种开链片螺素也是一类具有特殊生物活性的吡咯类生物碱,由于目前还未有关其提取的报道,因此对其进行合成具有重要意义.     

邻甲基苯磺酸铜催化"一锅法"合成3,4-二氢嘧啶-2(1H)-酮

二氢嘧啶酮(DHPMs)及其衍生物具有广泛的生物活性,如抗病毒、抗肿瘤、抗癌、抗高血压及消炎等作用[1].此外,DHPMs及其衍生物作为钙通道阻滞剂、α1a-对抗剂和神经肽Y的对抗剂,显示出良好的药理活性[2].更重要的是,最近几种含二氢嘧啶酮-5-羧酸盐的海洋生物碱被成功分离出来,并表现出重要的生物学性质[3],某些可以阻止HIVgp-120-CD4键的形成,是一种潜在的HIV抑制剂[4].因此,对DHPMs及其衍生物的研究成为生物活性有机杂环化合物的研究热点之一.     

Nonequilibrium Solvent Free Energy Curve from Molecular Theory in Electron Transfer Reaction

l.IntroductionEleCtrontransfer(ET)reactionisamongthemostfundaInentalofcheIIilstryandbiochendsny.Thetwrtanroleofevaluationofthes0lventfreeenergyandthercorganhaionenergyaninETprocesshasalwaysbeenreeogfordbyanextensiveliteratureindilsfield[1-2].HeneehowtochooseasuitablesolventreactioncoordinaeandconsequentlyconstructtheassociatedfreeenergyfimtionbecomesthCpriInnysteP,andalsotheaPplicabilityoftheenergygaPlaw.Manyrecentstudiesarefocusedonthesolventpolarizaionandsolventdyndcalbehaviorandmpmeeh…     

甜菜碱制备工艺的研究

甜菜碱[(CH3)3N+CH2COO-],是一种季铵型水溶性生物碱,可作为甲基供体,具有促进动物蛋白质和脂肪代谢、缓和应激、调节渗透压、增进食欲、稳定维生素、参与预防球虫病 [1-3],也可作为多功能表面活性剂,广泛用于制备护发护肤用品[4-5].甜菜碱的盐酸盐可用于胃酸缺乏、动脉粥样硬化、肝脏疾病、止痛、治疗风湿病、糖尿病等[6-8].甜菜碱制备方法[9-15]有天然甜菜糖蜜提取法和化学合成法.前者由于原料来源有限而使其应用推广具有一定的局限性.传统合成方法采用氯乙酸钠和三甲胺反应,生成的氯化钠很难除去[16].近年来对此的研究如采用强阳离子交换树脂法,溶剂法或者将氢氧化钠改为氢氧化钙[17-18]等.     

吡咯并二氢吲哚(+)-Flustramine B的立体选择性合成

吡咯并二氢吲哚和二吡咯并二氢吲哚代表着一类结构复杂的聚二氢吲哚生物碱,它们广泛存在于植物、海藻和两栖动物中[1].这类生物碱具有显著的生物活性,例如,从霉菌源分离出的( )-Flustramine B是缩胆囊肽和神经激肽受体的有力抗体[2].目前仅有Flustramine B的两个合成被报道,且两个都是外消旋形式[3].这里,我们将通过有机催化的吡咯并二氢吲哚的合成技术,一步对应选择性地合成Flustramine的溴-三环系统.     

朝鲜淫羊藿中生物碱类新成分的分离提取及结构鉴定

淫羊藿系小檗科淫羊藿属植物 ,具有补肾壮阳、强筋骨、祛风湿之功效 .现代药理研究表明 ,它还具有防治骨质疏松和提高免疫功能等作用 .2 0 0 0年版中国药典收载了 5种淫羊藿属植物 ,朝鲜淫羊藿为其中一种 ,是长白山道地中药材之一 .朝鲜淫羊藿中化学成分的研究多集中在黄酮类化合物方面 [1～ 6 ] ,而对其生物碱类化合物的研究较少 [7,8] .本文对朝鲜淫羊藿中生物碱类化合物进行了研究 ,并发现了一种新的生物碱 (6-羟基 -1 1 ,1 2 -二甲氧基 -2 ,2 -二甲基 -1 ,8-二氧 -1 ,3 ,4,8-四氢 -2 H -7-氧杂 -2 -氮 -苯并 [c]菲 ) ,采用核磁共振波…     

Al2O3/TiH2包覆粉体的制备及其释氢性能的研究

TiH2颗粒可以作为多孔铝的发泡剂[1,2]. Al2O3包覆TiH2颗粒与未包覆的TiH2颗粒相比, 可以起到控制(延迟)其发泡的作用, 提高泡沫铝材料的孔隙均匀性. 然而, 目前采用的包覆方法是将细小Al2O3粉通过机械研磨包覆在TiH2表面[3].本文尝试采用化学法制备Al2O3/TiH2包覆颗粒, 并研究其包覆的效果. 用化学法制备Al2O3/TiH2包覆颗粒, 并用其作为多孔铝制备中的发泡剂, 此项研究在国内外尚未见报道.     

Ipalbidine和Ipalbine的立体化学

1(ipalbidine)和2(ipalbine)是植物Ipomoea属中分离而得的两个生物碱,2具有光学活性.来源于南美洲同属植物alba L.的1为消旋体,而来源于中国同属植物华陀豆(I.hardwickii Hemsl)的1具有光学活性,其氢溴酸盐显示[α]_D~(25)十54.1°(c=1,C_2H_5OH).迄今,尚未有此二生物碱的绝对构型和优势环稠合构象的研究报道.     

ICP-AES测定铀污染土壤植物中铀的研究

采用电感耦合等离子体发射光谱(ICP-AES)对铀污染土壤植物中铀的测定方法进行了研究.在λU385.958 nm处,选择了仪器的最佳工作条件,考察了酸度和常见共存元素对测定的干扰情况,并且对比了干灰化消解和湿式消解对测定的影响.研究发现2%硝酸溶液为最佳介质,干扰离子对测定没有显著影响,干灰化消解比湿式消解得彻底.在选定条件下,方法检出限为0.18 mg·L-1,测定下限为0.61 mg·L-1,5.0000 mg·L-1的铀标准溶液的相对标准偏差RSD(n=10)为0.81%,方法回收率为96.2%～106.2%.该方法操作简单,快速.结果表明,用ICP-AES测定铀污染土壤植物样品中的铀是可行的.     

测定血清中Na 含量不确定度的评定

对血清中Na离子含量的测量不确定度进行评定。不确定度的来源主要包括Na离子标准工作液的配制过程、血清样品的定容消化制备、标准曲线拟合、钠离子各分量不确定度的合成等引入的不确定度计算出各分量的不确定度,通过合成得到测量结果的合成不确定度、扩展不确定度及测试结果的报告形式。     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

Production of radicals in the ozonolysis of propene in air

Radical production in the ozonolysis of propene in air was monitored directly by a peroxy radical chemical amplification (PERCA) instrument at room temperature (298±2 K) and atmospheric pressure (1×105 Pa). The ozonolysis reactions were conducted in a flow tube under pseudo-first-order conditions for ozone. The decay in ozone was calculated based on reaction time tr and effective rate constant keff (keff = k1[C3H6]0)) for the ozone-propene reaction. The total radical yields relative to consumed ozone were d...     

Kinetics of dehydration in chelates of quinones involved in photosystem-II

The solid-state deaquation of thetrans- andcis-oximates of lawsone (I) and phthiocol (II) with cobalt(II) was investigated by means of non-isothermal thermogravimetry. The modes of deaquation during the thermolyses of hydrated oximates of (I) and (II) with compositions CoL₂·2H₂O were compared. The weight lossvs. temperature data were treated by using the Coats and Redfern relations. The kinetic data support a rearrangement-type mechanism for the deaquation of the oximate of phthiocol. TheE _a values for both the ligands and water molecules were found to be 23 kJ/mol.

---

Zusammenfassung Mittels nichtisothermer Thermogravimetrie wurde die Dehydratation der trans- und cis-Kobalt(II)-oximate von Lawson (I) und Phthiokol (II) untersucht. Die Arten der Dehydratation während der Thermolyse der hydratierten Oximate von (I) und (II) mit der Zusammensetzung CoL₂·2H₂O wurden verglichen. Bei der Auswertung der Massenverlust-Temperatur-Daten wurden Coats-Redfern Beziehungen angewendet. Die kinetischen Daten bekräftigen einen Umlagerungsmechanismus für die Dehydratation des Oximates von Phthiokol. DieE _a Werte betragen sowohl für die Liganden als auch für Wasser etwa 23 kJ/mol.

---

- - (I) (II) . I II CoL₂ · 2₂ . -. . _a , 23 · ^–1

---

     

Use of matrix-modifiers in atomic-absorption determination of chromium in argillites

The direct atomic-absorption determination of chromium in argillites, without preliminary concentration and separation, has been studied. A map of selective flame zones for determining Cr in argillites has been designed. An express method for determining Cr in Estonian argillites has been suggested.     

Effect of vibration in processes of structure formation in polymers

It was shown that the strength characteristics of the samples produced from thermoplastics (low density polyethylene, polyamide 6, Armamid, and polyethylene terephthalate) increase as a result of short vibration treating with a frequency close to that of natural vibrations of the structural elements.