大丽轮枝菌毒素与拟南芥互作反应中SA、NO 与H_2O_2信号的相关性

本文研究了大丽轮枝菌毒素(VD-toxin)与拟南芥互作反应中外源SA、NO 供体、NO 合酶抑制剂等对拟南芥幼苗H_2O_2含量的影响,并对H_2O_2的积累部位进行了DAB 组化染色检测。大丽轮枝菌毒素、外源SA、NO 供体处理拟南芥幼苗均能诱导H_2O_2的积累,NO 供体的诱导作用最强;NO 合酶抑制剂处理则未表现出H_2O_2含量的增强;H_2O_2的积累部位主要在叶片的表皮毛和维管束组织。结果表明,在大丽轮枝菌毒素与拟南芥互作反应中,H_2O_2可能作为信号分子参与了SA 和NO 调控的拟南芥防卫反应,NO 信号与H_2O_2信号间的关系可能更密切。

CH_3S←CH_2SH异化反应的理论研究

利用密度泛函理论 (DFT)和从头算 (abinitio)研究了CH3 S CH2 SH互异化的反应机理 .采用HF、B3LYP、MP2理论水平和中等基组 6 31(d) ,计算了CH3 S、CH2 SH及其过渡态的结构参数、谐振频率、零点能(ZPE)、总能量和相对能量 ,并利用B3LYP/ 6 31(d)的方法计算了反应的内禀反应坐标 (IRC) ,给出了分子构型和自旋污染沿反应坐标的变化曲线 ,以及最小能量曲线 (MEP)、绝热能量曲线 .此外 ,利用传统过渡态理论(CTST)研究了该互异化反应的速率常数和平衡常数在 2 0 0～ 10 0

碳酸钠和碳酸氢钠与稀盐酸反应实验的创新设计

为探究碳酸钠溶液与稀盐酸分步反应的机理,设计了恒压式实验装置。用该实验装置探究碳酸钠溶液与稀盐酸互滴反应的过程,解析了向碳酸钠溶液中滴加稀盐酸至过量发生分步反应的实验教学难点问题,有助于在教学中使学生能更好地领悟相关的化学反应原理。

Influence of deformation passes on interface of SiC_p/Al composites consolidated by equal channel angular pressing and torsion

Powder mixture of pure Al and oxidized Si C was consolidated into 10%（mass fraction） Si Cp/Al composites at 250 °C by equal channel angular pressing and torsion（ECAP-T）. The valence states of Si for Si C particulates and Al for the as-consolidated composites were detected by X-ray photoelectron spectroscopy（XPS）. The interfacial bondings of the composites were characterized by scanning electron microscopy（SEM）. The elements at the interface were linearly scanned by energy dispersive spectroscopy（EDS） and the EDS mappings of Si and Al were also obtained. The values of the nanohardness at different positions within 2 μm from the boundary of Si C particulate were measured. The results show that after ECAP-T, interfacial reaction which inhibits injurious interfacial phase occurs between Al and the oxide layer of Si C, and the element interdiffusion which can enhance interfacial bonding exists between Al and Si C. As ECAP-T passes increase, the reaction degree is intensified and the element interdiffusion layer is thickened, leading to the more smooth transition of the hardness from Si C to Al.

Evidence That the Auxin Signaling Pathway Interacts with Plant Stress Response

Auxin influences a variety of developmental and physiological processes. Early reports, suggested that auxin might affect plant stress response. We have identified a number of auxin responsive genes in Arabidopsis thaliana (L.) Heynh. by using cDNA an-ay and found that stress responsive genes, such as,Arabidopsis homolog of MEK kinase 1 (ATMEKK1), ReL/SpoT homolog 3 ( At-RSH3), Catalase 1 ( Cat1) and Ferritin 1 (Fer1), were down-regulated by auxin, indicating that auxin regulates ale expression of stress responsive genes. We also demonstrated that nitrilase genes, nitrilase I ( NIT]) and nitrilase 2 (NIT2) involving in indole-3-acetic acid (IAA) biosynthesis, were induced by salinity stress, suggesting that the level of IAA might increase in response to salinity stress. To dissect the signal pathway involved in the interaction, two auxin insensitive mutants, auxin resistant 2 (axr2) and auxin resistant 1-3 (axrl-3) were used. Stress responsive genes were induced by salt stress in wild type and axr2, but not in axr1-3. The result suggests that die interaction between auxin and stress responses may be linked in the ubiquitin pathway.

Interface Reaction of SiO_2/Ta and Its Influence on Cu Diffusion

Ta/NiFe film is deposited on Si substrate precoated with SiO_2 by magnetron sputtering.SiO_2/Ta interface and Ta_5Si_3 standard sample are investigated by using X-ray photoelectron spectroscopy (XPS) and peak decomposition technique.The results show that there is a thermodynamically favorable reaction at the SiO_2/Ta interface:37Ta+15SiO_2=5Ta_5Si_3+6Ta_2O_5.The more stable products Ta_5Si_3 and Ta_2O_5 may be beneficial to stop the diffusion of Cu into SiO_2.

Sequencing of hepatitis C virus cDNA with polymerase chain reaction directed sequencing *

AIM To explore a rapid and easy sequencing method for hepatitis C virus (HCV) genome, and establish a new sequencing method in China. METHODS Polymerase Chain Reaction (PCR) was combined with DNA sequencing technique. PCR products were purified by agarose gel electrophoresis, polyacrylamide gel electrophoresis (PAGE), Polyethylene glycol (PEG) respectively. Then in the presence of a 5′ labeling PCR primer, purified PCR products were directly sequenced. By this method, HCV NS5b cDNA from two HCV infected individuals (HC 42 and HC 49) were sequenced.

浅议酸、碱、盐、氧化物的教学

浅议酸、碱、盐、氧化物的教学郝殿兰初中课本的第五章教材比较系统地介绍了酸、碱、盐、氧化物的定义、命名、通性和相互反应的初步规律，学生掌握了这些知识就能在以后学习元素和化合物时用一般规律去指导个别的学习，做到以简驭繁，因此该章的教材在整个初中化学课程中...

对我省1998年一道中考化学试题的浅析

1998年中考化学八·1题:现有石灰水、稀盐酸、铁、碳酸钠溶液和硝酸钡溶液,它们分别是右图A、B、C、D、E中的一种物质,它们之间的连线表明相邻的两种物质能发生反应。据此判断图中C、E表示的物质可能是(填化学式): 题目的知识构成 该题考查的知识内容涉及单质、氧化物、酸碱盐之间相互反应的有关知识。 经归纳,每种物质与其他物质之间能够发生反应的种数如下表:

Alkylation of p-Cresol with tert-Butanol Catalyzed by Novel Multiple-SO_3H Functioned Ionic Liquid

The alkylation of p-cresol with tert-butanol（TBA）to 2-tert-butyl-p-cresol（TBC）catalyzed by a novel multiple-SO3H functioned ionic liquid（IL1）was investigated.Meanwhile,the catalytic activity of this novel ionic liquid was compared with other four traditional ionic liquids.The results showed that IL1 has superior catalytic activity to other four traditional ionic liquids with the conversion of 85.3%and selectivity of 95.2%.Also,the reaction conditions were investigated to obtain the optimum conditions.Operational simplicity,small amount of usage,high activity,reusability and selectivity are the key features of this methodology.

Pyrolysis Mechanisms of Quinoline and Isoquinoline with Density Functional Theory

The pyrolysis mechanisms of quinoline and isoquinoline were investigated using the density functional theory of quantum chemistry,including eight reaction paths and a common tautomeric intermediate 1-indene imine.It is concluded that the conformational tautomerism of the intermediate decides the pyrolysis products(C6H6,HC≡C—C≡N,C6H5C≡N and HC≡CH)to be the same,and also decides the total disappearance rates of the reactants to be the same,for both original reactants quinoline and isoquinoline during the pyrolysis reaction.The results indicate that the intramolecular hydrogen migration is an important reaction step,which often appears in the paths of the pyrolysis mechanism.The activation energies of the rate determining steps are obtained.The calculated results are in good agreement with the experimental results.

Complement and its role in innate and adaptive immune responses

The complement system plays a crucial role in the innate defense against common pathogens. Activation of complement leads to robust and efficient proteolytic cascades, which terminate in opsonization and lysis of the pathogen as well as in the generation of the classical inflammatory response through the production of potent proinflammatory molecules. More recently, however, the role of complement in the immune response has been expanded due to observations that link complement activation to adaptive immune responses. It is now appreciated that complement is a functional bridge between innate and adaptive immune responses that allows an integrated host defense to pathogenic challenges. As such, a study of its functions allows insight into the molecular underpinnings of host-pathogen interactions as well as the organization and orchestration of the host immune response. This review attempts to summarize the roles that complement plays in both innate and adaptive immune responses and the consequences of these interactions on host defense.

Zinc finger E-box-binding homeobox 1 mediates aerobic glycolysis via suppression of sirtuin 3 in pancreatic cancer

AIM TO uncover the roles of tumor-promoting gene ZEB1 in aerobic glycolysis regulation and shed light on the underlying molecular mechanism.METHODS Endogenous zinc finger E-box binding homeobox-1 （ZEB1） was silenced using a and the impact of ZEB1 and lentivirus-mediated method, methyI-CpG binding domain protein 1 （MBD1） on aerobic glycolysis was measured using seahorse cellular flux analyzers, reactive oxygen species quantification, and mitochondrial membrane potential measurement. The interaction between ZEB1 and MBD1 was assessed by co-immunoprecipitation and immunofluorescence assays. The impact of ZEB1 and MBD1 interaction on sirtuin 3 （SIRT3） expression was confirmed by quantitative polymerase chain reaction, western blotting, and dual-luciferase and chromatinimmunoprecipitation assays.RESULTS ZEB1 was a positive regulator of aerobic glycolysis in pancreatic cancer. ZEB1 transcriptionally silenced expression of SIRT3, a mitochondrial-localized tumor suppressor, through interaction with MBD1.CONCLUSION ZEB1 silenced SIRT3 expression via interaction with MBD1 to promote aerobic glycolysis in pancreatic cancer.

Protein interaction network related to Helicobacter pylori infection response

AIM:To understand the complex reaction of gastric inflammation induced by Helicobacter pylori(H pylori) in a systematic manner using a protein interaction network. METHODS:The expression of genes significantly changed on microarray during H pylori infection was scanned from the web literary database and translated into proteins.A network of protein interactions was constructed by searching the primary interactions of selected proteins.The constructed network was mathematically analyzed and its biological function was examined.In addition,the nodes on the network were checked to determine if they had any further functional importance or relation to other proteins by extending them. RESULTS:The scale-free network showing the relationship between inflammation and carcinogenesis was constructed.Mathematical analysis showed hub and bottleneck proteins,and these proteins were mostly related to immune response.The network contained pathways and proteins related to H pylori infection,such as the JAK-STAT pathway triggered by interleukins.Activation of nuclear factor (NF)-κB,TLR4,and other proteins known to function as core proteins of immune response were also found. These immune-related proteins interacted on the network with pathways and proteins related to the cell cycle,cell maintenance and proliferation,andtranscription regulators such as BRCA1,FOS,REL,and zinc finger proteins.The extension of nodes showed interactions of the immune proteins with cancer- related proteins.One extended network,the core network,a summarized form of the extended network, and cell pathway model were constructed. CONCLUSION:Immune-related proteins activated by H pylori infection interact with proto-oncogene proteins.The hub and bottleneck proteins are potential drug targets for gastric inflammation and cancer.

A Kind of Predator-prey System of Holling Type II and Interaction Perturbation with Impulsive Effect

A kind of predator-prey system of Holling typeⅡand interaction perturbation with impulsive effect is presented.By using Floquet theory and small amplitude perturbations skills,the locally asymptotical stability of prey-eradication periodic solution and the permanence of the system are discussed and the corresponding threshold conditions are given respectively.Finally,the existence of positive periodic solution is investigated by the bifurcation theory.

Interplay between hepatitis B virus and the innate immune responses:implications for new therapeutic strategies

Hepatitis B virus(HBV) infection is still a worldwide health problem;however,the current antiviral therapies for chronic hepatitis B are limited in efficacy.The outcome of HBV infection is thought to be the result of complex interactions between the HBV and the host immune system.While the role of the adaptive immune responses in the resolution of HBV infection has been well characterized,the contribution of innate immune mechanisms remains elusive until recent evidence implicates that HBV appears to activate the innate immune response and this response is important for controlling HBV infection.Here,we review our current understanding of innate immune responses to HBV infection and the multifaceted evasion by the virus and discuss the potential strategies to combat chronic HBV infection via induction and restoration of host innate antiviral responses.

Understanding morphology-dependent Cu Ox-CeO2 interactions from the very beginning

Elucidation of the CuOx-CeO2 interactions is of great interest and importance in understanding complex CuOx-CeO2 interfacial catalysis in various reactions. In the present work, we have investigated structures and catalytic activity in CO oxidation of CuOx species on CeO2 rods, cubes and polyhedra predominantly exposing {110}+{100}, {100} and {111} facets by the incipient wetness impregnation method with the lowest Cu loading of 0.025%. The structural evolution of CuOx species was found to depend on both the Cu loading and the CeO2 morphology. As the Cu loading increases, CuOx species are deposited preferentially on the surface defect of CeO2 and then aggregate and grow, accompanied by the formation of isolated Cu ions, CuOx clusters strongly/weakly interacting with the CeO2, highly dispersed Cu O nanoparticles, and large Cu O nanoparticles. The isolated Cu^+ species and CuOx clusters weakly interacting with the CeO2 were observed mainly on the O-terminated CeO2{100} facets. Meanwhile, more Cu(I) species are stabilized during CO reduction processes in CuOx/c-CeO2 catalysts than in CuOx/r-CeO2 and CuOx/p-CeO2 catalysts. The catalytic activities of various CuOx/CeO2 catalysts in CO oxidation vary with both the CuOx species and the CeO2 morphology. These results comprehensively elucidate the CuOx-CeO2 interactions and exemplify their morphology-dependence.

心力衰竭大鼠血液亚甲基四氢叶酸还原酶和CITED2基因表达水平与血气波浪式信号的相关性研究

目的研究心力衰竭(HF)大鼠血液亚甲基四氢叶酸还原酶(MTHFR)基因和c AMP反应元件结合蛋白/P300互作反式激活因子2(CITED2)基因的表达水平与血气波浪式信号的相关性。方法 SPF级8周龄的雌性Wistar大鼠建立HF模型大鼠分为Sham组和HF组(n=8)。Sham组大鼠仅暴露左冠状动脉前降支和HF组进行左冠状动脉前降支结扎。手术后7周监测血流动力学指标,和血气波浪式信号,收集术后1周、3周、7周大鼠的血液,7周后安乐死大鼠收集心脏组织。使用HE染色法观察大鼠心脏病理变化,q RTPCR检测1周、3周、7周大鼠血液汇总MTHFR和CITED2基因的表达,试剂盒法检测血液MTHFR和CITED2基因启动子区的甲基化水平。皮尔森相关性检测法分析MTHFR和CITED2基因表达和血气波浪式信号的相关性。结果 HF组血液MTHFR和CITED2的表达[(2.51±0.52)和(3.19±0.24)]高于Sham组[(1.00±0.00)和(1.00±0.00),t=12.079、9.635,P<0.05]。HF组血液MTHFR和CITED2[(0.78±0.06)和(1.05±0.11)]的启动子区甲基化水平低于Sham组[(1.22±0.31)和(1.67±0.27),t=13.821、15.633,P<0.05]。HF组中MTHFR水平与血氧分压(Pa O2)[(6.01±1.29)mm Hg]和动脉血氧饱和度(Sa O2)(0.19±0.04)%呈负相关性(t=-0.521、-0.786,P<0.05)。CITED2水平与Sa O2呈负相关性(t=-0.839,P<0.05)。结论 HF大鼠血液MTHFR和CITED2基因表达升高与血氧饱和度降低有关。

Screening and identifkation of proteins interacting with nudeostemin

AIM： To identify the proteins interacting with nucleostemin （NS）, thereby gaining an insight into the function of NS. METHODS： Yeast two-hybrid assay was performed to screen a human placenta cDNA library with the full length of NS as a bait. X-Gal assay and β-galactosidase filter assay were subsequently conducted to check the positive clones and the gene was identified by DNA sequencing. To further confirm the interaction of two proteins, the DNA fragment coding NS and the DNA fragment isolated from the positive clone were inserted into the mammalian expression vector pcDNA3 and pcDNA3-myc, respectively. Then, two plasmids were cotransfected into the COS-7 cells by DEAE-dextron. The total protein from the cotransfected cells was extracted and coimmunoprecipitation and Western blot were performed with suitable antibodies sequentially. RESULTS： Two positive clones that interacted with NS were obtained from human placenta cDNA library. One was an alpha isoform of human protein phosphatase 2 regulatory subunit B （B56） （PPP2RSA） and the other was a novel gene being highly homologous to the gene associated with spondylo paralysis. The co-immunoprecipitation also showed that NS specifically interacted with PPP2R5A. CONCLUSION： NS and PPP2R5A interact in yeast and mammalian cells, respectively, which is helpful for addressing the function of NS in cancer development and progression.