The interaction between the membrane-proximal external region and the N-trimer region of HIV-1 gp41: Involvement in viral fusion

The membrane proximal external region (MPER) of gp41 is extremely conserved among diverse HIV-1 variants, implying its important role in viral infection. Interestingly, two of the most broadly neutralizing antibodies, 2F5 and 4E10, specifically recognize this region. Our previous study demonstrated that the antigenicity and immunogenicity of 4E10 epitope are affected by remodeling gp41 fusion core, suggesting that the MPER may be associated with gp41 core and involved in gp41-mediated membrane fusion. Here we measured the binding activity of 4E10 epitope peptide (D4E10P) with various gp41 core-derived peptides and found that the N-trimer region in a construct designated N-trimer-6HB interacted significantly with D4E10P. Using N-trimer-6HB to screen a phage library, we identified a motif (WF) located in 4E10 epitope that may play a certain role in the interaction of gp41 MPER with the N-trimer in gp41 fusion core and, we thus speculated upon the potential involvement of MPER in the fusion process between viral envelope and target cell membrane. Supported by National Key Basic Research and Development Program of China (Grant No. 2007CB914402)     

ZnS：Mn^2＋的合成及光学特性研究

我们利用溶剂热的方法,合成了ZnS以及ZnS:Mn2+纳米粒子.并利用X射线衍射、透射电镜、光致发光等测试手段对样品的结构和光学性能进行了表征.结果表明,Mn2+以替代Zn2+的方式进入到了ZnS晶格当中,并且随着Mn2+掺杂量的增加,样品的晶粒尺寸明显减小.从PL谱图可以清楚看到黄光的发射光谱,其伴随着Mn2+离子3d壳层内部的4T1-6A1转变.     

甲基三氧化铼在MCM-41中的组装及其对烯烃环氧化反应的催化性能

γ-(三乙氧基硅基)丙胺与MCM-41反应, 得到氨丙基化的MCM-41, 进而利用氨基与2-吡啶甲醛的缩合反应制得双氮螯合配体修饰的MCM-41; 利用双氮螯合配体与甲基三氧化铼(MTO)的配位, 实现MTO在MCM-41上的组装. X射线光电子能谱(XPS)分析表明, 铼主要以 +Ⅶ价态存在; 傅里叶变换红外光谱(FT-IR)、紫外漫反射光谱(DR UV-vis)分析结果证明了配体与铼之间配位键的形成; X射线粉末衍射(XRD)、 透射电子显微镜(TEM)以及氮气吸附结果表明, MCM-41引入官能团以及MTO组装后, 其六方一维孔道结构得到保持, 但孔体积、比表面积 以及孔径发生明显变化. 此外, 还利用元素分析以及原子吸收等方法分析了组装材料中碳、氢、氮以及铼的含量. 分别以30%双氧水、过氧化氢尿素复合物(UHP)为氧化剂, 考察了其对不同烯烃环氧化反应的催化性能. 当以UHP为氧化剂在25°C对环己烯环氧化时, 反应的转化率约为50%, 选择性大于99%; 而在同样温度下, 以30%双氧水对环己烯环氧化时, 反应的转化率约为40%, 选择性约为20%. 较低的催化活性是由于底物在MCM-41中传质较慢, 而组装的MTO又在环氧化条件下分解所致.     

不同硅铝比的Beta/MCM-41复合分子筛的合成和性能

分别以四乙基氢氧化铵和十六烷基三甲基溴化铵作为微孔相和介孔相的模板,采用两步晶化法制备了4种具有不同硅铝比,含微孔和介孔双模孔结构的Beta/McM-41复合分子筛.采用X射线衍射、N2吸附-脱附对Beta/MCM-41复合分子筛的结构进行了表征,利用吡啶吸附红外光谱(Py-FTIR)以及正庚烷裂解作为探针反应,对不同硅铝比的Beta/MCM-41复合分子筛的酸量和催化性能进行了研究.实验结果表明,随投料硅铝比的增加,复合分子筛介孔相有序性逐渐提高,微孔相的结晶度逐渐减小,酸量降低,正庚烷裂解的转化率明显下降.说明该复合分子筛的性能可随硅铝比的变化进行调变.     

SrAl_(12)O_(19):Mn~(2+)晶体的吸收光谱及g因子的理论研究

本文引入平均共价因子, 采用点电荷模型, 对SrAl12O19:Mn2+晶体的吸收光谱及因子进行理论研究, 计算结果表明理论值与实验值符合较好. 其次, 利用=110时g因子的实验值, 得出了键长随温度变化的关系.     

MCM-41有序介孔分子筛制备及表征的DTA、XRD、UV分析

用铝酸纳,硅酸钠为原料,C16TMAB为模板制备MCM-41有序介孔分子筛。将其浸泡在Ti2(SO4)3溶液中进行自组装,通过对组装前后的样品分别做DTA、XRD及UV分析,结果表明MCM-41具有较大的比表面和较好的热稳定性,在催化领域拥有光明的情景。     

锂离子电池正极材料LiNi0.5Mn0.5O2制备及光谱研究

用共沉淀法合成了Li Ni0.5Mn0.5O2材料.为了探索共沉淀法合成Li Ni0.5Mn0.5O2的最佳工艺,详细研究了研磨时间、pH值、预处理温度、煅烧温度、煅烧时间和冷却方式等对材料结构的影响.以氢氧化锂为锂源,Ni(NO3)2.6 H2O和Mn(Ac)2.4 H2O为镍源和锰源,锂与镍、锰物质的量比为1.1∶0.5∶0.5,经强氧化剂处理,900℃下煅烧12 h后经淬冷制备了Li Ni0.5Mn0.5O2样品.采用XRD,Raman和XPS对该样品进行了分析,结果表明:材料为标准的α-NaFeO2层状结构,属于六方晶系;镍以正二价的形式存在,锰主要以正四价存在,非常接近理论计算的理想结构.     

低温熔盐法合成球形LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2研究

采用低温熔盐法合成了锂离子电池正极材料Li Ni1/3Co1/3Mn1/3O2,并就低温熔盐0.62xLi NO3-0.38xLi OH-(1-x)CH3COOLi.2 H2O的具体比例、焙烧温度和焙烧时间对材料的影响进行了对比研究.XRD结果表明以x=0.6的低温共熔盐,经3阶段温度烧结(200℃,3 h;600℃,制备的样品的α-NaFeO2层状结构发育的较为完备.SEM扫描显示材料是由许多片状晶体构成的球形颗粒.材料在2.8～4.3 V范围内充放电,倍率为0.2 C时,首次放电比容量为173.6 mA.h.g-1,循环20次后容量保留97.4%;倍率为1 C时,首放126.0 mA.h.g-1,循环20次后容量保留94.1%.     

Mn-Si 系多层焊焊缝侧弯形貌的研究

本文通过焊接接头侧弯试验、光学显微镜和扫描电镜分析，对Ｍｎ－Ｓｉ系多层焊焊缝侧弯形貌进行了研究，探讨了侧弯形貌与焊接热循环、焊接线能量及显微组织之间的关系。研究表明，焊缝侧弯形貌分析是了解Ｍｎ－Ｓｉ系多层焊焊缝变形能力的一种直观有效的途径。     

Petrogenesis of the Neoproterozoic bimodal volcanic rocks along the western margin of the Yangtze Block： New constraints from Hf isotopes and Fe/Mn ratios

High-precision major element and Hf isotope data are reported for the Neoproterozoic Suxiong volcanic rocks along the western margin of the Yangtze Block. These volcanic rocks have variable εHf（T） values and Fe/Mn ratios. The relatively primitive basalts have high Fe/Mn ratios and high Hf-Nd isotopic compositions, indicating that they were generated by partial melting of garnet clinopyroxene in mantle plume at high pressure. Thus, the Suxiong basalts are genetically related to the proposed Neoproterozoic superplume. On the contrary, a few differentiated basalts have low Fe/Mn ratios and low Hf-Nd isotopic compositions. They are likely to experience assimilation-fractional crystallization process. The Suxiong rhyolites have consistent Hf and Nd model ages of 1.3-1.4 Ga. They are likely generated by shallow dehydration melting of pre-existing young arc igneous rocks associated with the basaltic underplating/intrusion in a continental rift.