动物模型在HIV-1杀微生物剂有效性和安全性评价中的应用

HIV/AIDS的流行趋势没有减弱的迹象,人们迫切需要新的预防HIV传播的手段。杀微生物剂旨在通过局部用药于阴道或直肠,从而阻止HIV的传播。鉴于目前有大量的杀微生物剂候选物,亟待能够有效评价其有效性及安全性的动物模型。通过比较非灵长类小型动物模型与非人灵长类动物模型在评价HIV杀微生物剂的有效性及安全性上的重要作用,该文总结了评价杀微生物剂有效性及安全性的动物模型的优缺点,同时指出了杀微生物剂研究与发展的方向和建议,希望能够对杀微生物剂的研发有所帮助。

The Effects of Visual Object Size in The Depth Perception in KM Mouse

Whether mice perceive the depth of space dependent on the visual size of object targets was explored when visual cues such as perspective and partial occlusion in space were excluded. A mouse was placed on a platform the height of which is adjustable. The platform located inside a box in which all other walls were dark exception its bottom through that light was projected as a sole visual cue. The visual object cue was composed of 4x4 grids to allow a mouse estimating the distance of the platform relative to the grids. Three sizes of grids reduced in a proportion of 2/3 and seven distances with an equal interval between the platform and the grids at the bottom were applied in the experiments. The duration of a mouse staying on the platform at each height was recorded when the different sizes of the grids were presented randomly to test whether the Judgment of the mouse for the depth of the platform from the bottom was affected by the size information of the visual target. The results from all conditions of three object sizes show that time of mice staying on the platform became longer with the increase in height. In distance of 20 similar to 30 cm, the mice did not use the size information of a target to judge the depth, while mainly used the information of binocular disparity. In distance less than 20 cm or more than 30 cm, however, especially in much higher distance 50 cm, 60 cm and 70 cm, the mice were able to use the size information to do so in order to compensate the lack of binocular disparity information from both eyes. Because the mice have only 1/3 of the visual field that is binocular. This behavioral paradigm established in the current study is a useful model and can be applied to the experiments using transgenic mouse as an animal model to investigate the relationships between behaviors and gene functions.

抑郁症首次发病患者静息态脑功能局部一致性的研究

下载PDF阅读器目的 利用功能磁共振(fMRI)和局部一致性(regional homogeneity,ReHo)探讨抑郁症首次发病(以下简称首发)患者在静息态脑功能是否存在异常及异常部位.方法 对34例符合美国精神疾病诊断与统计手册第4版诊断标准的首发抑郁症患者(抑郁症组)和34名性别、年龄、文化程度匹配的健康志愿者(对照组)进行静息态fMRI扫描.结果 抑郁症组静息态脑血氧水平依赖信号的ReHo高于对照组的脑区有左侧额叶眶回、顶下小叶、颞上回,右侧额内侧回、顶下小叶、小脑后叶;低于对照组的脑区有左颞下回、右颞上同和胼胝体、双侧后扣带回(P＜0.005,K≥10).结论首发抑郁症患者在静息态存在多个腩区功能活动的异常,并可能和抑郁症的病理机制有关.

沉淀剂YNB99—1在肝素钠精制中的应用

在pH 3．0时，去除85和95～105 USP u／mg粗品肝素钠的杂蛋白分别使用 0．05％和0．03％的YNB 99一l。120 USP u／mg以上的粗品在pH中性下直接使用0．05％ 的YNB 99—1即可。在氧化精制中，加入0．005％的YNB 99—1可使HzOz用量减少至 1．5％，氧化时间缩短至12 h。精品效价170 USP u／mg以上，产品收率90％以上。

滇池北部湖湾不同底泥性状对微囊藻复苏影响的模拟

滇池北部福保湾主要承接上游昆明市的生活污水及周边工业污水,其污染程度极为严重.本研究在福保湖湾内设置4个采样点,分别采集了不同区域的沉积物,首次模拟研究了微囊藻(Microcystis)在不同沉积物环境中复苏能力差异,结果表明微囊藻在模拟实验中的复苏能力表现出对不同底质的不同适应性,入口湖区的沉积物对微囊藻的复苏有极强的抑制作用.藻类复苏后达到的最大生物量(以叶绿素a计)分别为东岸对照区的4.7%,西岸对照区的6.6%及吹填区的11.9%,其中微囊藻生物量也远低于其它各样点,占东岸对照、吹填区及西岸对照的

拥挤胁迫后鲫鱼血液皮质醇和溶菌酶水平的变化及对病原的敏感性

分别在拥挤胁迫后第3、10、20、30天对鲫鱼(Carassiusauratus)血液皮质醇水平和血液溶菌酶水平进行了检测,并在每次采集血样后用嗜水气单胞菌(Aeromonashydrophila)进行人工感染以评估鱼体抵抗力。结果显示,血液皮质醇水平在胁迫后几天内显著升高(P<0.005),随后虽有所下降,但至第30天高密度组仍保持较高水平(216.32±11.91)ng/mL。实验初期,血液溶菌酶水平小幅升高,但经过长时间的拥挤后,高密度组血液溶菌酶活性受到极大抑制,显著低于同期对照组(P<0.01)

拥挤胁迫对草鱼非特异性免疫功能的影响

在实验室条件下利用放养密度和放养时间构建组间差异,模拟养殖过程中草鱼所面临的拥挤胁迫。胁迫第7、14、30、60d后采样测量免疫指标。结果表明,高密度组(80g·L-1)的血清溶菌酶活性在胁迫后开始升高,并于14d时达峰值,以后逐渐下降,呈倒"U"型趋势。血清杀菌活性随放养密度的剧增而锐减(P<0.005)。白细胞比容在各组间未显示明显差异。而在30d和60d所测的高密度组草鱼的头肾巨噬细胞吞噬百分率和吞噬指数结果显示,高密度组低于对照组(P<0.05)。60d后用嗜水气单胞菌进行攻毒实验,高密度组死亡率

硫酸铜强化固氮蓝藻生长的研究

培养基中添加0.005—0.03ppm 铜能强化固氮蓝藻生长。混合藻种(鱼腥藻属混合藻种)、固氮鱼腥藻 Anabaena azotica(水生686)和多变鱼腥藻 Anabaena variabslis(水生1058)最佳铜浓度分别为0.01ppm 和0.03ppm。池底铺土进行培养固氮蓝藻,铜浓度的范围略宽。

铜、汞、镉、六六六和对硫磷对食蚊鱼生长的影响

对2日龄的食蚊鱼仔鱼的急性毒性,96小时LC_(50)是:铜,0.28毫克/升;汞,0.58亳克/升;镉,10.2毫克/升;六六六(丙体),0.53毫克/升;对硫磷,0.3毫克/升。依据20天的生长数据求得的铜、镉和对硫磷的最大允许毒物浓度分别是0.015—0.030、0.005—0.010和0.0015—0.0030毫克/升,相应的应用系数分别为0.05—0.1、0.0005—0.0009和0.005—0.01。

水中硝酸盐的快速测定法

本文叙述水中微量硝酸盐的快速测定法。主要采用Bray之粉剂,加入硫酸铜作催化剂(Cu~(++)16.3微克/10毫升)和加长振荡时间控制硝酸盐的还原程度,致使灵敏度增加。用光电比色计可测至0.02 ppm硝酸根中之氮,用纳氏管可到0.005 ppm。再现性及稳定性均好。误差不超过5％。

Quantitative Determination of Microcystins in Rat Plasma by LC-ESI Tandem MS

A rapid and sensitive method was developed and validated for the determination of MCYST (microcystin)-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma by liquid chromatography-tandem mass spectrometry. The analytes were extracted from rat plasma by protein precipitation, followed by solid-phase extraction. Liquid chromatography with electrospray ionization mass spectrometry, operating in selected reaction monitoring (SRM) mode, was used to quantify MCYST-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma. The recoveries for each analyte in rat plasma ranged from 70.8 to 88.7%. The calibration curve was linear within the range from 0.005 to 1.25 mu g mL(-1). The limit of detection were 1.4, 1.0, 0.6 ng mL(-1) for MCYST-RR, -LR, and [Dha(7)] MCYST-LR. The overall precision was determined on three different days. The values for within- and between-day precision in rat plasma were within 15%. This method was applied to the identification and quantification of microcystins in rat plasma with acute exposure of microcystins via intravenous injection.

Crustacean zooplankton size structure in aquaculture lakes: is larger size structure always associated with higher grazing pressure?

Crustacean zooplankton size structure in 27 aquaculture lakes was studied to test the hypothesis that larger size structure is associated with higher grazing pressure. Mean body length of crustaceans was positively correlated with increasing Chl a (r(2) = 0.40, P = 0.000) and TP (r(2) = 0.38, P = 0.000), contrary to the empirical studies. However, the ratio of zooplankton to phytoplankton biomass decreased significantly with increasing TP (r(2) = 0.27, P = 0.005) and mean body length (r(2) = 0.46, P = 0.000). Meanwhile, size structure showed no significant effect in explaining residual variations of phosphorus-chlorophyll relationship (P = 0.231). These results indicate that larger size structure was not always associated with higher zooplankton grazing pressure. It is likely that in aquaculture lakes crustacean zooplankton size structure was of minor importance in control of phytoplankton biomass, and it was mainly regulated by fish predation. The results showed in our study and the empirical studies might be a reflection of two different stages of lake eutrophication and fish predation intensity.

An ELISA-like time-resolved fluorescence immunoassay for microcystin detection

Background: A time-resolved fluorescence immunoassay (TRFIA), based on anti-microcystin-LR (MCLR) monoclonal antibodies (MAbs) and europium-labeled antimouse IgG conjugate, was first developed for microcystin detection. Methods: Anti-MCLR MAbs were prepared by a standard method, and the attained MAbs showed a good cross reactivity with MCLR, MCRR and MCYR. The TRFIA was performed in an indirect competitive mode. The detection method of TRFIA was compared with indirect competitive enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Results: The TRFIA exhibited a typical sigmoidal response for MCLR at concentrations of 0.005-50 ng/ml, with a wide quantitative range between 0.01 and 10 ng/ml, indicating the broadest detective range and the most sensitive of all the methods for microcystins (MCs) detection. Additionally, the TRFIA maintained good reliability through its quantitative range, as evidenced by low coefficients of variation (1.6-12.2%). The toxin data of algal samples assayed from TRFIA were in the same range as those with ELISA and HPLC, implying that the method was reliable and practical for the detection of MCs. Conclusions: The TRFIA may offer a valuable alternative or a substitute for conventional ELISA for microcystin detection. (C) 2004 Elsevier B.V. All rights reserved.

High-temperature AlN interlayer for crack-free AlGaN growth on GaN

This paper presents a study of the transformation of high-temperature AlN (HT-AlN) interlayer (IL) and its effect on the strain relaxation of Al0.25Ga0.75N/HT-AlN/GaN. The HT-AlN IL capped with Al0.25Ga0.75N transforms into AlGaN IL in which the Al composition increases with the HT-AlN IL thickness while the total Ga content keeps nearly constant. During the HT-AlN IL growth on GaN, the tensile stress is relieved through the formation of V trenches. The filling up of the V trenches by the subsequent Al0.25Ga0.75N growth is identified as the Ga source for the IL transformation, whose effect is very different from a direct growth of HT-AlGaN IL. The a-type dislocations generated during the advancement of V trenches and their filling up propagate into the Al0.25Ga0.75N overlayer. The a-type dislocation density increases dramatically with the IL thickness, which greatly enhances the strain relaxation of Al0.25Ga0.75N. (c) 2008 American Institute of Physics.

InAs nanostructure grown with different growth rate in InAlAs matrix on InP (001) substrate

InAs self-organized nanostructures in In0.52Al0.48As matrix have been grown on InP (001) substrates by molecular beam epitaxy. The morphologies of the nanostructures are found to be strongly dependent on the growth rate of the InAs layer. By increasing the growth rate from 0.005 to 0.35 ML/s, the morphology of the nanostructure changes from wire to elongated dot and then changes back to wire again. Polarized photoluminescence of the InAs quantum wires and quantum dots are performed at 77 K, which are characterized by strong optical anisotropies. (C) 2003 Elsevier B.V. All rights reserved.