菜花烙铁头蛇毒中一种具有激肤释放酶与纤维蛋白原溶酶活性的Jerdonase

通过DEAF Sephadex t-50阴离子交换、超细Sephadex 6100分子筛和反相高效液相CQ色谱层析，从菜花烙铁头蛇毒冻干粉中纯化出一种具有激肤释放酶活性和。纤维蛋白原溶酶活性的丝氨酸蛋白酶，命名为Jerdonase。在12 .5%胶浓度的SD6还原电泳条件下，该酶分子量大约为55 kD，在非还原电泳条件下，分子量大约为53 kD。此酶是一种糖蛋白，含有约35 .8%的中性糖。它的N末端氨基酸序列为IIGGDEENINEHPFLVALYDA，其序列和蛇毒中其他丝氨酸蛋白酶具有非常高的序列相似性。Jerdonase能够催化BAEE、 S-2238和S-2302的水解，其水解活性可被PMSF抑制，但是EDTA对此没有影响。Jerdonase能优先水解人纤维蛋白原的An链，同时伴随有微弱的B[3链水解活性。另外，此酶能够水解牛低分子量的激肤原，释放舒缓激肤。总之，所有的结果表明Jerdonase是一个具有多功能活性的蛇毒丝氨酸蛋白酶。

Jerdonase, a novel serine protease with kinin-releasing and fibrinogenolytic activity from Trimeresurus jerdonii venom

A novel kinin-releasing and fibrin (ogen)olytic enzyme termed jerdonase was purified to homogeneity from the venom of Trimeresurus jerdonii by DEAE Sephadex A-50 anion exchange, Sephadex G-100 (superfine) gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). Jerdonase migrated as a single band with an approximate molecular weight of 55 kD under the reduced conditions and 53 kD under the non-reduced conditions. The enzyme was a glycoprotein containing 35.8% neutral carbohydrate. The N-terminal amino acid sequence of jerdonase was determined to be IIGGDECNINEHPFLVALYDA, which showed high sequence identity to other snake venom serine proteases. Jerdonase catalyzed the hydrolysis of BAEE, S-2238 and S-2302, which was inhibited by phenymethylsulfonyl fluoride (PMSF), but not affected by ethylenediaminetetraacetic acid (EDTA). Jerdonase preferentially cleaved the Aalpha-chain of human fibrinogen with lower activity towards Bbeta-chain. Moreover, the enzyme hydrolyzed bovine low-molecular-mass kininogen and releasing bradykinin. In conclusion, all results indicated that jerdonase was a multifunctional venom serine protease.

陕西秦岭平河梁自然保护区小型兽类的组成与分布

2005年9月利用铗日法辅以陷阱法对位于秦岭山脉南坡东段的平河梁自然保护区及牛背梁自然保护区小型兽类进行了调查,共设置采集点10个;2 460铗日中共捕获小型兽类689只,隶属于3目6科19属27种(另有两种鼢鼠和一种鼯鼠系其他手段捕获),平均捕获率28.01%.对捕获的27种小型兽类生态和垂直分布进行分析结果表明:平河梁保护区3个群落的Shannon-Weiner多样性指数在2.9288-3.3639之间,Pielou均匀性指数在0.7669-0.8602之间.在上述调查的基础上,结合前人对邻近地区的调查,据一些物种的分布特点,订出平河梁自然保护区小型兽类的名录,计48种,结果显示秦岭南坡东段小型兽类的物种多样性和丰富度要高于秦岭其他地区.另在考察中采集到白尾鼹(Parascaptor leucura)、小纹背鼩鼱(Sorex bedfordiae)、斯氏鼢鼠(Myospalax smithⅡ)、川西白腹鼠(Niviventer excelsior),在秦岭山区尚属首次记录.还整理了秦岭南坡小型兽类名录,认为秦岭南坡有小型兽类55种,在动物地理区划上应属于西南区.

Parallel implementation of Multilevel BDDC

In application of the Balancing Domain Decomposition by Constraints (BDDC) to a case with many substructures, solving the coarse problem exactly becomes the bottleneck which spoils scalability of the solver. However, it is straightforward for BDDC to substitute the exact solution of the coarse problem by another step of BDDC method with subdomains playing the role of elements. In this way, the algorithm of three-level BDDC method is obtained. If this approach is applied recursively, multilevel BDDC method is derived. We present a detailed description of a recently developed parallel implementation of this algorithm. The implementation is applied to an engineering problem of linear elasticity and a benchmark problem of Stokes flow in a cavity. Results by the multilevel approach are compared to those by the standard (two-level) BDDC method.

饲料中不同维生素C含量对长吻的影响

用维生素C含量为38、364和630mg/kg的三种饲料饲喂初体重为(23.19±0.58)g的长吻8个月,实验结果表明,38mg/kgVC饲料组饲喂的长吻表现出了典型的VC缺乏症状:体色发黑,脊椎侧弯,鳍边由开始的萎缩直到腐烂、贫血、特定生长率显著降低(p<0.05)。并且38mg/kgVC饲料组长吻的生理指标也受到影响:血清溶菌酶活性显著下降(p<0.05),肝脏的SOD活性及MDA含量均显著升高(p<0.05),血清皮质醇没有显著差异(p>0.05),但各处理组长吻肝脏中均未检测到诱导型HS

Flaw sizing in pipes using long-range guided wave testing

The absence of adequate inspection data from difficult-to-access areas on pipelines, such as cased-road crossings, makes determination of fitness for continued service and compliance with increasingly stringent regulatory requirements problematic. Screening for corrosion using long-range guided wave testing is a relatively new inspection technique. The complexity of the possible modes of vibration means the technique can be difficult to implement effectively but this also means that it has great potential for both detecting and characterizing flaws. The ability to determine flaw size would enable the direct application of standard procedures for determining fitness-for-service, such as ASME B31G, RSTRENG, or equivalent for tens of metres of pipeline from a single inspection location. This paper presents a new technique for flaw sizing using guided wave inspection data. The technique has been developed using finite element models and experimentally validated on 6'' Schedule 40 steel pipe. Some basic fitness-for-service assessments have been carried out using the measured values and the maximum allowable operating pressure was accurately determined. © 2011 American Institute of Physics.

不同生态修复措施下太湖西五里湖沉积物氮磷形态的时空分布

以太湖西五里湖为研究对象,研究了生态修复工程实施两年后,疏浚区、疏浚并水生植被重建示范区、退渔还湖区及对照区沉积物中氮、磷形态的季节变化及垂直分布特征,同时分析了各区上覆水的氮磷含量.结果表明:生态修复措施的实施对沉积物中氯磷形态分布及上覆水的氮磷含量影响显著.示范区和退渔还湖区水体中氮磷含量较低;沉积物中不同磷形态的垂直分布变化较复杂;疏浚基础上进行的水生植被重建对Lab-P、Al-P、Fe-P的吸收作用显著,对Ca-P、Org-P的影响较小;退渔还湖区沉积物磷形态以Ca-P、Org-P为主,Fe-P所

水华蓝藻生物质对沉水植物五刺金鱼藻生长的影响

本文研究了蓝藻水华不同的生物质形式对金鱼藻生长和光合活性的影响,结果表明:蓝藻水华的不同生物质形式均不同程度地促进了金鱼藻的生长。在促进金鱼藻植株的长度增长方面,干燥蓝藻的作用最强,新鲜蓝藻次之,腐烂蓝藻作用最弱,但都比对照增长显著。而在促进金鱼藻植株鲜重增长上,干燥蓝藻和新鲜蓝藻的作用几乎相同,为最为明显的;腐烂蓝藻次之;而对照植株的鲜重先增加后下降。在促进金鱼藻分枝上,新鲜蓝藻的作用最强,干燥蓝藻和腐烂蓝藻次之,对照的分枝随时间也逐渐增加,但是要比经过蓝藻处理的试验组少。测定的叶绿素荧光参数表明,干燥

柱状黄杆菌胞外多糖对草鱼的免疫促进作用

将柱状黄杆菌胞外多糖(EPS)溶液经腹腔注射免疫草鱼,以注射灭菌生理盐水作对照。免疫一周后,分别提取受免鱼与对照鱼肝脏、脾脏、体肾和头肾4种组织中的总RNA,并通过RT-PCR半定量的方法检测不同组织中C-反应蛋白(CRP)、白介素1(IL-1)、主要组织相容性复合体I(MHC I)、免疫球蛋白M(IgM)、干扰素(IFN)等5种免疫基因的表达情况。结果显示,CRP在受免鱼肝脏中的表达显著上升;MHC I在受免鱼脾脏、体肾中的表达显著下降;IgM在受免鱼4种组织中的表达皆显著上升;IL-1在受免鱼4种组织

Spin glass behaviour and spin-dependent scattering in la 0.7Ca 0.3Mn 0.9Cr 0.1O 3 perovskites

The magnetic, electrical and thermal transport properties of the perovskite La 0.7Ca 0.3Mn 0.9Cr 0.1O 3 have been investigated by measuring dc magnetization, ac susceptibility, the magnetoresistance and thermal conductivity in the temperature range of 5-300K. The spin glass behaviour with a spin freezing temperature of 70 K has been well confirmed for this compound, which demonstrates the coexistence and competition between ferromagnetic and antiferromagnetic clusters by the introduction of Cr. Colossal magnetoresistance has been observed over the temperature range investigated. The introduction of Cr causes the "double-bump" feature in electrical resistivity ρ(T). Anomalies on the susceptibility and the thermal conductivity associated with the double-bumps in ρ(T) are observed simultaneously. The imaginary part of ac susceptibility shows a sharp peak at the temperature of insulating-metallic transition where the first resistivity bump was observed, but it is a deep-set valley near the temperature where the second bump in ρ(T) emerges. The thermal conductivity shows an increase below the temperature of the insulating-metallic transition, but the phonon scattering is enhanced accompanying the appearance of the second peak of double-bumps in ρ(T). We relate those observed in magnetic and transport properties of La 0.7Ca 0.3Mn 0.9Cr 0.1O 3 to the spin-dependent scattering. The results reveal that the spin-phonon interaction may be of more significance than the electron (charge)-phonon interaction in the mixed perovskite system. © 2005 Chinese Physical Society and IOP Publishing Ltd.