Study of apolipoprotein E genetic polymorphism in patients with atherosclerotic cerebral infarction

Objective: To explore the frequency and significance of ApoE gene polymorphisms in Chinese patients with atherosclerotic cerebral infarction (ACI). Methods: Polymerase chain reaction and gene sequencing, single nucleotide polymorphisms of ApoE gene were used to analyze 33 cases of patients with ACI and 35 controls. Results: The frequencies of ApoE gene single nucleotide polymorphisms 465C/G, 462C/G and 451delC in the ACI group were significantly higher than those in the control group (P<0.05). The prevalence of polymorphism 486G/T in the control group was significantly higher than that in the ACI group (P=0.011). Conclusions: 465C/G,462C/G and 451delC polymorphisms might be associated with ACI.486GT allele might have protective effect on the pathogenesis of ACI.     

Degradation of pyrene and characterization of<Emphasis Type="Italic">Saccharothrix</Emphasis> sp. PYX-6 from the oligotrophic Tianchi Lake in Xinjiang Uygur Autonomous Region,China

Bacterial strain PYX-6 that utilizes anthracene,phenanthrene, or pyrene for carbon and energy sources for growth was isolated from a non-polluted lake (Tianchi Lake) in Xinjiang Uygur Autonomous Region of China. Its morphology, physiological and biochemical properties, cell wall pattern and G C mol% content of DNA molecules were characterized. The 16S rRNA gene of strain PYX-6 was sequenced and analyzed for similarities to related bacterial species. Results indicated that strain PYX-6 is a member of the Genus Saccharothrix, and the strain was named Saccha-rothrix sp. PYX-6. When pyrene was the sole carbon source in cultural medium, the strain PYX-6 assimilated pyrene for growth and 0.005% of yeast extract stimulated pyrene degradation and assimilation. The optimal pH of cultural medium and the optimal shaking frequency during cultivation were 6-8 and 200 r/m, respectively. It was found that the disappearance of pyrene in medium occurred before significant growth of strain PYX-6 took place. Phthalic acid, benzylacetic acid, and benzylpropenoic acid were detected as catabolic intermediates during pyrene degradation with mass spectroscopy and this result indicated that Saccharothrix sp.PYX-6 adopted a pathway that is different from the pathway of the previously reported pyrene-degrading Mycobacterium sp. PYR-1.     

Nitric oxide produced by cumulus cells stimulates maturation of mouse oocytes

The effect of sodium nitroprusside (SNP), a donor of nitric oxide, on meiotic maturation of mouse oocytes was studied by injecting N^w-nitro-L-arginine methyl ester (L-NAME) intra-peritoneal (ip), a nitric oxide synthase inhibitor, or culturing oocytes in the medium supplemented with L-NAME or hypoxanthine (HX) to arrest the spontaneous oocyte maturation in vitro. The results showed that the inhibitory effect of L-NAME by injecting 10 mg/kg ip on extrusion of the first polar body only could be reversed by injecting 2.5 mg/kg SNP with L-NAME simultaneously (P < 0.05). Half an hour later ten mice died when given 10 mg/kg SNP ip. The treatment of some concentrations of SNP (10^–7, 10^–6, 10^–5mol/L) significantly stimulated meiotic maturation to metaphase Ⅱ stages in cumulus enclosed oocytes in the presence of HX. However, other concentrations of SNP (10^–8, 10^–4, 10^–3 mol/L) had no effect on HX-arrested oocyte meiotic maturation. The optimal concentration of SNP on CEOs had no effect on DOs. The dose of 10^–3 mol/LL-NAME demonstrated a significant suppression in formation of PB₁, but not in GVBD. This inhibition was reversed by the addition of SNP. These results indicated that the physiological levels of NO produced by cumulus cells could stimulate meiotic maturation of mouse oocytes both in vivo and in vitro.     

关于热力学函数关系式的推导

本文着重讨论运用雅可比行列式推导热力学关系式的技巧问题。     

公路涵洞常见病害分析与防治措施

根据对所在地区各类公路涵洞的调查,分析涵洞常见的病害及针对病害原因提出相应的处治对策及预防措施.     

公路涵洞常见病害分析与防治措施

根据对所在地区各类公路涵洞的调查,分析涵洞常见的病害及针对病害原因提出相应的处治对策及预防措施。     

基于模糊关联规则的股票市场交易规则抽取

将模糊关联规则应用于股票市场的交易规则抽取,以期能为投资者投资做出正确决策.首先选用聚类方法对模糊集属性进行离散化,进而构造模糊集和隶属函数,给出模糊集构造算法,最后提出适合股票交易规则抽取的模糊关联规则算法FARS.实验结果表明,所得规则能很好的反映股票交易中的实际情况.     

基于模拟退火算法的空气污染危害指数及其应用

在设定各项污染物危害浓度参照值基础上,得出了一个基于模拟退火算法（SA）优化的适用于多种空气污染物的空气质量评价的污染危害普适指数公式.该公式应用于大量实例的分析评价结果与其他多种评价方法评价结果比较表明：该公式不受污染物种类和数目多少的限制,计算简便,具有可比性、通用性和实用性,评价结果与实际符合较好.     

热轧层流冷却过程改进模型建立与仿真研究

针对热轧层流冷却过程非线性、强耦合等特性,对热轧层流冷却过程进行了系统模型分析,并在层流冷却物理过程分析的基础上提出改进方案——将整个物理过程划分为热辐射、空气对流、冷却水对流、辊道热传递和热相变5个部分。对影响卷取温度的关键单元——设定单元进行模型改进,在该模型基础上开发了仿真系统软件,并进行了模型验证和对比,这些表明该系统稳定可靠,可用于现场参数分析和新产品的开发。     

基于互反判断矩阵的专家群体判断一致性分析

针对群决策中基于互反判断矩阵形式偏好信息的专家群体判断一致性问题,提出了一种分析方法。首先,给出了有关互反判断矩阵及其相容性和一致性的若干定义;然后,通过定义各个方案的一致性指标及专家群体判断一致性指标,给出了基于互反判断矩阵的专家群体判断一致性的判别方法及专家群体判断不一致的调整方法。最后,通过算例说明了所提的分析方法。