基于Vif-APOBEC3G相互作用的抗HIV-1药物研究

载脂蛋白B mRNA编辑酶催化多肽样蛋白3G(apolipoprotein B mRNA-editing enzyme catalyticpolypeptidelike3G,APOBEC3G或A3G)是人体天然抗病毒分子,可以使病毒逆转录形成的cDNA的胞嘧啶(C)脱氨为尿嘧啶(U),产生鸟嘌呤(G)→腺嘌呤(A)超突变,导致病毒转录产物突变,从而达到抑制病毒复制的作用。HIV-1的辅助蛋白Vif,可与APOBEC3G相互作用并导致其被降解,使得这一天然抗病毒机制失效,进而增强了HIV的感染力。Vif与APOBEC3G这种相互作用为抗HIV药物提供了新靶点。针对Vif-APOBEC3G相互作用的抗HIV抑制剂已经成为研究热点。本文综述了Vif和APOBEC3G的结构、二者的相互作用,以及基于这一相互作用的抗HIV-1抑制剂研究进展。

HIV抗原抗体联合检测试剂盒适用于体外病毒感染p24抗原检测

比较Vironostika HIV UniformⅡAg/Ab抗原抗体联合检测试剂盒、Vironostika HIV-1 p24抗原检测试剂盒和自制p24单克隆抗体在实验室检测不同HIV毒株体外细胞感染复制的灵敏度。比较3种检测方法在抗HIV药物筛选研究中的应用。方法：HIV抗原抗体联合检测试剂盒和p24抗原检测试剂盒检测严格按说明书操作。自制p24单克隆抗体检测HIV-1 p24抗原采用Fc抗体捕捉双抗夹心法。结果: 3种检测方法检测病毒谱相同，p24抗原检测试剂盒灵敏度最高，HIV抗原抗体联合检测试剂盒其次，自制p24抗原检测法灵敏度最低。检测抗HIV药物AZT 和 IDV抑制病毒复制的剂量曲线，HIV抗原抗体联合检测试剂盒与自制p24抗原检测法均可呈现很好的“S”型剂量曲线，检测IC50一致。HIV抗原抗体联合检测试剂盒灵敏度比自制p24抗原检测法高20倍。p24抗原检测试剂盒灵敏度高但检测范围窄(5-80pg/mL)，导致剂量曲线不明显。 结论: HIV抗原抗体联合检测试剂盒适用于实验室体外病毒感染复制的p24抗原检测。

First principles study of N-N split interstitial in GaN nanowires

Atomic and electronic properties of N-N split interstitial in GaN nanowires have been investigated using first principles calculations. The formation energy calculations show that the N-N interstitial favors substituting an N atom at the surface of the nanowires. The interstitial induces localized states in the band gap of GaN nanowires.

Charge Separation in Wurtzite/Zinc-Blende Heterojunction GaN Nanowires

The electronic properties of wurtzite/zinc-blende (WZ/ZB) heterojunction GaN are investigated using first-principles methods. A small component of ZB stacking formed along the growth direction in the WZ GaN nanowires does not show a significant effect on the electronic property, whereas a charge separation of electrons and holes occurs along the directions perpendicular to the growth direction in the ZB stacking. The later case provides an efficient way to separate the charge through controlling crystal structure. These results have significant implications for most state of the art excitonic solar cells and the tuning region in tunable laser diodes.

基于人工神经网络的区域水环境承载力评价模型及其应用

在分析水环境承载力概念及人工神经网络技术基础之上,从阈值角度出发,建立了基于人工神经网络的区域水环境承载力评价模型,并将其应用于辽宁省水环境承载力评价,通过模型计算得到该省水环境承载能力指数。结果表明,2000—2004年,辽宁省水环境承载能力指数分别为0·29、0·36、0·32、0·37和0·43,整体上呈上升趋势,但承载力依然较弱。本文提出的水环境承载力评价模型具有结构简单、建模方便的特点,评价结果可以直观地反映区域水环境承载状态。

Efficient organic electroluminescent devices based on an organosamarium complex

Several organic electroluminescent devices with different device structures were fabricated based on an organosamarium complex Sm(HFNH)(3)phen[HFNH=4, 4, 5, 5, 6, 6, 6-heptafluoro-l-(2-naphthvl)hexane-1, 3-dione; phen=1, 10-phenanthroline] as emitter. Their electroluminescent properties were investigated in detail. Although the devices with the optimal structure ITO/TPD (50nm)/ Sm(HFNH)(3)phen (xwt%):CBP (50nm)/BCP (20nm)/AIQ (30nm)/LiF (1 nm),/Al (200nm) show high brightness (more than 400cd/m(2)) and high current efficiency (about 1 cd/A), there are emissions from CBP, BCP and even from AIQ existing in the electroluminescence (EL) spectra besides emission from Sm(HFNH)(3)Phen. The reason to this was discussed. The device with the structure ITO/TPD (50 nm)/ Sm(HFNH)(3)phen (50 nm)/AIQ (30 nm)/LiF (1 nm)/Al (200 nm) exhibits the maximum brightness of 118 cd/m(2) and current efficiency of 0.029 cd/A, and shows emissions from AIQ and Sm(HFNH)(3)phen at high voltages. However, with the BCP hole-block layer added, the device [ITO/TPD (50 nm)/Sm(HFNH)(3)phen (50 nm)/BCP (20 nm)/AIQ (30 nm)/LiF (1 nm)/Al (200 nm)] exhibits pure Sm3+ emission in 2 the EL spectra even at high voltages, with the maximum current efficiency of 0.29cd/A and brightness of 82cd/m(2)

(η~5-C_9H_7)_2Yb(THF)_2的晶体结构

双(茚基)镱(Ⅱ)四氢呋喃配合物(η~5-C_9H_7)_2Yb(THF)_2的晶体属单斜晶系,C_c空间群,晶体学参数a=13.506(4),b=11.081(2),c=15.577(5),β=92.68(3)°,V=2329(1),D_c=1.56g/cm~3,Z=4,μ=42.4cm~(-1),F(000)=1088,最终编离因子R=0.029,R_w=0.031。中心离子Yb~(2+)与两个茚基以η~5形式成键且与两个四氢呋喃中的氧成键,茚基的两个质心和四氢呋喃中的两个氧形成扭曲的四面体,Yb~(2+)在四面体的中心。Yb~(2+)的配位数为8。Yb~(2+)到质心In1的距离为2.52,到质心In2的距离为2.40。Yb~(2+)到O(1)的键长为2.356(7),到O(2)的键长为2.417(5)。

PrP_5O_(14)的晶体结构与铁弹畴

本文用X射线衍射方法研究了PrP_5O_(14)的晶体结构和铁弹相变。晶体空间群为P2_1/c,晶胞参数a=8.777(1)A,b=9.029(2)A,c=13.068(2)A,β=90.35°(1),z=4,最终R值为0.046。在130±5℃转变成正交晶系,空间群为P_(ncm),a=8.813(7)A,b=9.075(2)A,c=13.119(10)A。高温相变使晶体产生了铁弹性孪晶,室温下晶体属mmmF2/m类铁弹体。

He, Ne and Ar isotopic composition of Fe-Mn crusts from the western and central Pacific Ocean and implications for their genesis

The noble gas nuclide abundances and isotopic ratios of the upmost layer of Fe-Mn crusts from the western and central Pacific Ocean have been determined. The results indicate that the He and Ar nuclide abundances and isotopic ratios can be classified into two types: low He-3/He-4 type and high He-3/He-4 type. The low He-3/He-4 type is characterized by high He-4 abundances of 191x10(-9) cm(3.)STP(.)g(-1) on average, with variable He-4, Ne-20 and Ar-40 abundances in the range (42.8-421)x10(-9) cm(3.)STP(.)g(-1), (5.40-141)x10(-9)cm(3.)STP(.)g(-1), and (773-10976)x10(-9) cm(3.)STP(.)g(-1), respectively. The high He-3/He-4 samples are characterized by low He-4 abundances of 11.7x10(-9) cm(3.)STP(.)g(-1) on average, with He-4, Ne-20 and Ar-40 abundances in the range of (7.57-17.4)x10(-9) cm(3.)STP(.)g(-1), (110.4-25.5)x10(-9) cm(3.)STP(.)g(-1) and (5354-9050)x10(-9) cm(3.)STP(.)g(-1), respectively. The low He-3/He-4 samples have He-3/He-4 ratios (with RIRA ratios of 2.04-2.92) which are lower than those of MORB (R/R-A=8 +/- 1) and Ar-40/Ar-36 ratios (447-543) which are higher than those of air (295.5). The high He-3/He-4 samples have He-3/He-4 ratios (with R/R-A ratios of 10.4-12.0) slightly higher than those of MORB (R/R-A=8 +/- 1) and Ar-40/Ar-36 ratios (293-299) very similar to those of air (295.5). The Ne isotopic ratios (Ne-20/Ne-22 and Ne-21/Ne-22 ratios of 10.3-10.9 and 0.02774-0.03039, respectively) and the Ar-38/Ar-36 ratios (0.1886-0.1963) have narrow ranges which are very similar to those of air (the Ne-20/Ne-22, Ne-21/Ne-22, Ar-38/Ar-36 ratios of 9.80, 0.029 and 0.187, respectively), and cannot be differentiated into different groups. The noble gas nuclide abundances and isotopic ratios, together with their regional variability, suggest that the noble gases in the Fe-Mn crusts originate primarily from the lower mantle. The low He-3/He-4 type and high He-3/He-4 type samples have noble gas characteristics similar to those of HIMU (High U/Pb Mantle)- and EM (Enriched Mantle)-type mantle material, respectively. The low He-3/He-4 type samples with HIMU-type noble gas isotopic ratios occur in the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain and the Mid-Pacific Seamounts whereas the high He-3/He-4 type samples with EM-type noble gas isotopic ratios occur in the Line Island Chain. This difference in noble gas characteristics of these crust types implies that the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain, and the Mid-Pacific Seamounts originated from HIMU-type lower mantle material whereas the Line Island Chain originated from EM-type lower mantle material. This finding is consistent with variations in the Pb-isotope and trace element signatures in the seamount lavas. Differences in the mantle surce may therefore be responsible for variations in the noble gas abundances and isotopic ratios in the Fe-Mn crusts. Mantle degassing appears to be the principal factor controlling noble gas isotopic abundances in Fe-Mn crusts. Decay of radioactive isotopes has a negligible influence on the nuclide abundances and isotopic ratios of noble gases in these crusts on the timescale of their formation.

RP-HPLC测定几种花类药材黄酮含量

目的：为充分利用花类药材，建立马蔺花、桃花、月季等15种花类药材中黄酮含量测定的RP—HPLC方法，并比较它们的含量。方法：花类药材用甲醇提取，反相高效液相色谱法分析药材中槲皮素、山柰酚、异鼠李素3种黄酮苷元。结果：采用KromasilC_18柱（4．6mm×250／mm，5μm），以甲醇-0．1％磷酸（50：50）为流动相，可使3种黄酮苷元达到基线分离，其中马蔺花含槲皮素1．536％，桃花含山柰酚0．572％，茶花含异鼠李素0．029％，皆为听测样品中最高。结论：本实验首次采用RP—HPLC法测定这15种花类药材的总黄酮含量，本方法操作简便，快速，准确，可作为黄酮的定量分析方法。

北太平洋西部和印度洋东部及其邻近海域表层水体中^137Cs的分布

对北太平洋西部海域、苏禄海及印尼海、中国南海、印度洋东部海域、孟加拉湾及安达曼海等表层水体中放射性核素 137Cs 的活度进行了测定。结果表明，上述海域表层水体中 137Cs 活度显示了较大的变化范围，最低值出现在南极附近的南大洋 ( 1.1 Bq m-3)，较高的活度值则出现在北太平洋西部海域及中国南海 ( 3 Bq m-3)。在所研究水域范围内，137Cs 活度的纬度分布特征并没有完全有效地反映出 137Cs 的全球理论大气沉降趋势及其纬度效应。综合本研究及 Miyake 等人 ( 1988 ) 的测定结果，我们计算出 137Cs 自表层海水中的析出速率在苏禄海及印尼海约为 0.016 /a，在孟加拉湾及安达曼海约为 0.033 /a，在国南海约为0.029 /a，这一结果明显低于西北太平洋日本沿海表层水体中 137Cs 的析出速率。这可能是因为在这些海域，横向及纵向的水体混合过程相对都较慢，而且颗粒物对 137Cs 的吸附析出过程也比较弱所致。

Heat capacity and thermochemical study of trifluoroacetamide (C2H2F3NO)

The low-temperature heat capacities of trifluoroacetamide were precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 404 K. A solid-to-solid phase transition, a fusion and a phase transition from a liquid crystalline phase to fully liquid phase have been observed at the temperatures of 336.911+/-0.102, 347.622+/-0.094 and 388.896+/-0.160 K, respectively. The molar enthalpies of these phase transitions as well as the chemical purity of the substance were determined to be 5.576+/-0.004, 11.496+/-0.007, 1.340+/-0.005 kJ mol(-1) and 99.30 mol%, respectively, on the basis of the heat capacity measurements. The molar entropies of the three phase transitions were calculated to be 16.550+/-0.012, 33.071+/-0.029 and 3.447+/-0.027 J mol(-1) K-1, respectively. Further researches of the thermochemical properties for this compound have been carried out by means of TG and DSC techniques. (C) 2000 Elsevier Science B.V. All rights reserved.

Wspólnota z przypadku. Studium tożsamości mieszkańców Naddniestrza

Wydział Historyczny

O prazer associado ao consumo de alimentos e factores influenciadores

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

Sleep Patterns in Elementary School Children (Grades 2-5) and Adolescents (Grade 10)

Background: To date, there is limited research examining sleep patterns in elementary school children. Previous researchers focused on parental responses rather than student responses to determine factors that affect sleep. The presented study surveyed sleep patterns and examined external factors affecting total sleep time among elementary school children and adolescents. Methods: Students in grades 2-5 (n=885) and grade 10 (n=190) enrolled in a public school system in the Northeast, completed a district administered survey that included questions on sleep duration and hygiene. Results. Average reported sleep duration decreased with increasing grade level. Children in grades 2-5 woke up earlier (31.7-72.4%) and on their own in comparison to adolescents in grade 10 (6.8%). Significantly shorter sleep durations were associated with having a television (grades 2, 4, 5, p< 0.01) or a cell phone in the room (grades 3, 4; p < 0.05), playing on the computer or video games (grades 3, 4, p<.001) before going to bed. In contrast, students in grade 2, 3, & 4 who reported reading a book before going to bed slept on average 21 minutes more per night (p=.029, .007, .009, respectively). For tenth graders, only consumption of energy drinks led to significant reduction in sleep duration (p<.0001). Conclusion. Sleep is a fundamental aspect in maintaining a healthy and adequate life style. Understanding sleep patterns will assist parents, health care providers, and educators in promoting quality sleep hygiene in school-aged children.