Prevalence of hepatitis B virus infection and phylogenetic analysis of HBV S gene among high school students

目的了解江苏省海门市高中生乙型肝炎感染情况及其HbV S基因的变异情况。方法采用整群抽样方法抽取江苏省海门市职业中心校的407名高三学生进行乙肝血清学调查;采用酶联免疫吸附法(ElISA)和巢氏聚合酶链式反应(PCr)扩增方法检测血清样本的乙型肝炎表面抗原(HbSAg)、乙型肝炎病毒表面抗体(抗-HbS)和乙型肝炎病毒(HbV)S基因并进行进化分析。结果 407名高中生中乙肝表面抗原(HbSAg)阳性率为6.39%;在家中、乡镇卫生院和县级及以上医院出生学生的HbSAg阳性率分别为11.76%、8.02%和2.27%,差异有统计学意义(P<0.05);抗-HbS滴度≥10u/l者占72.5%,且呈u形分布;不同乡镇、不同性别学生抗-HbS滴度差异有统计学意义(P<0.01);407名高中生HbV S基因均为C基因型,主要变异在蛋白疏水区,抗原决定簇A区未发生免疫原性改变。结论出生时接受的医疗水平对HbV感染有影响;海门市高中生HbV S基因受到正选择作用而出现变异,但未发生免疫原性改变。Objective To understand the hepatitis B infection and HBV S gene variation among high school students in Haimen city,Jiangsu province.Methods A serological survey of hepatitis B was conducted in a high school with cluster sampling method.HBsAg and anti-HBs were detected with ELISA,and phylogenetic analysis for HBV S gene with nested PCR.Results HBsAg positive rate was 6.39% and the rate for the students born at home,township health centers,and hospital above the county level was 11.76%,8.02%,and 2.27%,respectively,with significant difference(P<0.05).The percentage of the students with anti-HBs titer ≥ 10U/l was 72.5%,and the titer distribution was U-shaped.The difference in anti-HBs titer between boys and girls,as well as different towns,was statistically significant(P<0.01).All genotype of HBV S gene was C-type,and the main variation was in protein hydrophobic area.The change of immunogenicity in antigenic determinant "a" zone was not observed.Conclusion The level of health care at birth can affect the HBV infection among high school students in Haimen.S gene variation occurs through positive selection,but not antigenicity.国家科技支撑计划(2006BAI02A03);传染病重大专项(2008ZX10002-012);上海市重点学科项目(B118

Raman and AFM Characterization of Au and Cu Nanorod and Nanowire Arrays

通过电化学氧化法制备具有不同孔径氧化铝模板 ,利用交流电镀的方法在模板中沉积金属 ,再用酸溶解模板可以得到相应尺度的金属纳米线或纳米棒的阵列 .本文利用原子力显微镜和表面增强拉曼技术分别表征了金和铜两种金属纳米线阵列 .研究结果表明 ,作为探针分子的硫氰(SCN )在金属纳米线上的碳氮三键的振动频率随纳米线直径的增大而蓝移 .这一现象可能是因为尺寸效应对纳米线的费米能级造成影响 ,使不同直径的金属纳米线电子结构存在微小的差别 .Recently metal nanowires (nanorods) have aroused tremendous interest because of their novel properties and potential applications in wide fields [1] . Many two?dimensional nanowire arrays of semiconductors and metals with different diameter and length have been made by using template synthesis method. To characterize the novel optical, electronic and magnetic properties of these materials, UV?Vis and fluorescence spectroscopies are two of the most wildly used methods [2, 3] . Raman spectroscopy has, however, only been applied to the characterizing of semiconductor nanowires and carbon nanotubes [4,5] . Important and meaningful information can be obtained in these cases, as some forbidden Raman modes in the bulk materials become Raman active [4, 5] . Raman spectroscopy is apparently not suitable to study metal nanowires since it can only detect the mechanical vibration bands located in the extremely low frequency region. Consequently, an alternative way has to be established to study the metal nano?wires (?rods) with Raman spectroscopy. In the present work, we have taken the probe molecule strategy and used surface?enhanced Raman spectroscopy (SERS) to characterize metal nanorods (nanowires). It is well known that for a molecule which interacts strongly with a surface, its vibrational band frequency and shape are very sensitive to the electronic property, the chemical environment and the morphology of the surface. Hence Raman spectroscopy has long been used to analyze the atomic structures and the electronic properties of the surface indirectly through assessing carefully the spectral changes of the adsorbate known as a probe molecule. On that account, it is of great interest to diagnose the electronic structures of the metal nanorods with the vibrational spectrum of a probe molecule. We have examined the changes in the electronic properties of the nanorods through analyzing the spectral changes of the probe molecule. For this purpose a typical SERS molecule of SCN - was employed. The nanorod arrays of Au and Cu with different diameter from about 15 nm to 130 nm were fabricated electrochemically by means of the anodic aluminum oxide (AAO) templates. To partially expose metal nanowires with various lengths, the AAO template was chemically etched off to a certain extent by an aqueous solution of phosphoric acid or sodium hydroxide as shown in Fig. 1. After the template was etched off, the nanowires can be characterized by TEM, see Fig. 2. The tapping mode AFM image was obtained on a scanning probe microscope (Nanoscope IIIa). SERS measurements were performed on a confocal microprobe Raman system (LabRam I).作者联系地址：厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,南京师范大学化学系!江苏南京,210097,厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,厦门大学固体表面物理化学国家重点实验室!Author's Address: State Key Lab.for Phys.Chem.of Solid Surf.,Xiamen Univ.,Xiamen 361005, China; 1 Dept. of Chem., Nanjing Norm

农田CO_2通量观测的研究进展

多角度认识农田生态系统在CO_2源或汇的问题有助于中国制定正确的农业管理措施,通过减少农田生态系统碳的排放或增加碳的储存,可以使中国在国际排放权的争夺中处于主动地位;笔者总结了国内外最新文献中农田CO_2交换量的研究现状和通量观测方法;对近年来国内外农田生态系统CO_2交换量研究所取得的进展进行了详细阐述,并介绍了测量农田生态系统CO_2通量的微气象法和箱法等通量观测的代表性方法,列表说明了涡度相关法、静态透明箱法、静态暗箱法三者存在的优缺点。分析了提高农田生态系统碳交换测定通量的准确性的途径及扩大不同农作物CO_2测定量的适用范围;对农田生态系统CO_2交换量观测全面深入研究提出了一些建议和展望

热带季节雨林近地层CO_2堆积的气象条件分析

热带雨林内CO2浓度分布随近地层CO2堆积现象的出现而发生显著变化,对估算林内各层植被冠层CO2储存项有直接影响.通过寻找形成近地层CO2堆积的主要气象控制因子,有助于判别不同气象条件在近地层CO2堆积中的作用.采用基于因子分析的主成分提取方法,将8个气象因子观测资料整合为3个主成分,并逐一揭示4个典型时期各主成分的支配因子在近地层CO2堆积形成中的作用.结果表明:热量条件是影响11—12月(雾凉季)、3—4月(干热季)、9—10月(雨季后期)近地层CO2堆积的主要气象条件.水分条件是6—7月(雨季前期)近地层CO2堆积的主要气象条件.动力条件对近地层CO2堆积影响较弱,仅起到辅助作用

金、铜金属纳米棒或纳米线的AFM和SERS的研究(英文)

通过电化学氧化法制备具有不同孔径氧化铝模板 ,利用交流电镀的方法在模板中沉积金属 ,再用酸溶解模板可以得到相应尺度的金属纳米线或纳米棒的阵列 .本文利用原子力显微镜和表面增强拉曼技术分别表征了金和铜两种金属纳米线阵列 .研究结果表明 ,作为探针分子的硫氰(SCN )在金属纳米线上的碳氮三键的振动频率随纳米线直径的增大而蓝移 .这一现象可能是因为尺寸效应对纳米线的费米能级造成影响 ,使不同直径的金属纳米线电子结构存在微小的差别