对锯痕中锯路波反映锯齿特点的研究

为了充分利用现场遗留的锯路波痕迹,推断作案用锯的种类,笔者用木锯制作了大量带有锯路波的锯痕,并对实验样本进行分析测量,采用统计学中二独立样本的t检验方法对断面形态与锯齿组合的关系进行分析,找出了锯路波波纹方向与进锯方向夹角和锯齿角度的关系、进锯方向上的波距与同侧齿距的关系,为工具痕迹的锯痕检验提供参考。     

激励测试原理及作用探析

激励测试属于知情测试法的一种，是正式测试前的预演，不仅能够检测被测人的生理反应是否正常，促使被测人熟悉测试过程，在正式测试前合理调整仪器参数，而且可以赢得被测人对心理测试（测谎）技术的信任，增加心理效应，同时能够激发被测人的行为表征，利于辅助生理图谱进行判断。如果操作得当，能够起到应有的激励作用。为了提高激励测试的准确率，需要采取一定的措施：第一，采用多种方法；第二，测试内容多样化；第三，增加被测人说谎的恐惧感；第四，精心设计测试的某些细节。     

用丙硫苯咪唑检测羊线虫抗药性的体外虫卵孵化试验

为探讨用丙硫苯咪唑进行体外虫卵孵化试验检测羊线虫对苯并咪唑类药物的抗药性,对23个羊场的25份田间样品用丙硫苯咪唑和噻苯咪唑进行了虫卵孵化试验并与先前减卵试验(faecal egg count re-duction test,FECRT)的结果比较。结果表明,25份样品中,丙硫苯咪唑和噻苯咪唑对受检虫卵的半数致死量(LD50)均值分别为0.050 1和0.054 0μg/mL,差异不显著。FECRT检测有抗药性的4个羊场,75%的样品对丙硫苯咪唑和噻苯咪唑的LD50均值均在0.1μg/mL以上,只有1个羊场的的LD50值分别为0.068 9μg/mL(丙硫苯咪唑)和0.071 2μg/mL(噻苯咪唑)。检测为可疑的2个羊场,其样品的LD50值为0.04~0.07μg/mL;FECRT检测敏感的蠕虫群体的LD50均在0.04μg/mL以下。此外,丙硫苯咪唑用纯的二甲基亚砜溶解和稀释后于4℃保存7 d,LD50值变化不大,提示药效无明显下降,而保存14 d后药效有下降趋势。     

关于无纸化考试管理信息系统的探讨

当今考试越来越多地采用无纸化考试模式 ,与之配套出现的考试管理信息系统。先进的技术手段 ,合理的系统设计 ,使考试管理信息系统确实起到保证考试质量 ,加强考务管理规范化、自动化和科学化的作用。     

新疆马鼻肺炎的血清学调查

对新疆 11个地、州的 2 1个县 (市 )的 2 82 1份血清样品用微量补体结合试验进行了马鼻肺炎血清学调查。结果 ,仅在吉木萨尔县和奇台县境内检出 2 5份阳性血清。调查表明 ,虽然在新疆境内存在马鼻肺炎 ,但情况并不严重     

日本血吸虫DNA疫苗对黄牛的田间免疫试验

用VRSj2 8、VRSj2 3和VRSj2 8+VRSj2 3对黄牛免疫后 ,在日本血吸虫病流行区云南省洱源县进行日本血吸虫田间自然攻击 5 4d ,免疫牛的减成虫率为 3 3 .0 %～ 44 .0 % (P <0 .0 5 ) ,粪便和肝组织的减卵率较高 ,特异性IgG在首次免疫后显著增高。提示 ,用此类疫苗对牛进行大规模免疫预防 ,可减少人群感染的机会。     

鸡IL-18基因重组真核表达载体的构建及其表达产物的生物学活性

从pMDChIL18克隆质粒扩增获得了ChIL18全基因片段,并将其重组到真核表达载体pcDNA3.1( )。经酶切、质粒PCR鉴定和基因测序,鸡IL18全基因被正确重组到pcDNA3.1( )真核表达质粒上;将重组真核表达质粒pcDNA3.1( )ChIL18转染COS7细胞,转染细胞中含ChIL18基因的mRNA。SDSPAGE分析表明,表达产物是与ChIL18相符的约23ku的蛋白条带。鸡淋巴细胞转化试验表明,表达产物对鸡淋巴细胞具有明显诱导转化作用。     

A survey of the concentration of 19-OH F1α/F2α prostaglandins in the semen of fertile, infertile and vasectomized men and their stability in both liquid semen and semen stains

The levels of 19-hydroxy-prostaglandins F₁α/F₂α (PG F) in the semen of 19 vasectomized, 44 infertile and 8 fertile men were determined using a simple RIA technique. The mean concentrations observed in this survey were 45 μg/ml, 49.5 μg/ml and 59 μg/ml, respectively. No significant difference was recorded between the vasectomized and infertile groups; there were too few fertile samples available to undertake a meaningful statistical comparison. No reduction was observed in the levels of this PG in a liquid semen sample retained at room temperature over a 4 week period in the presence of a bacteriostat (sodium azide). However, a 30% reduction in the levels of 19-OH PG F occurred over the same time period when aliquots of the same semen sample were retained at either room temperature or at 4°C without azide. Finally, no reduction was observed in the concentration of 19-OH PG F in a series of 10-μl semen stains stored over a period of 6 weeks at room temperature.     

Phenolphthalein False‐Positive Reactions from Legume Root Nodules

Presumptive tests for blood play a critical role in the examination of physical evidence and in the determination of subsequent analysis. The catalytic power of hemoglobin allows colorimetric reactions employing phenolphthalein (Kastle‐Meyer test) to indicate “whether” blood is present. Consequently, DNA profiles extracted from phenolphthalein‐positive stains are presumed to be from blood on the evidentiary item and can lead to the identification of “whose” blood is present. Crushed nodules from a variety of legumes yielded phenolphthalein false‐positive reactions that were indistinguishable from true bloodstains both in color quality and in developmental time frame. Clothing and other materials stained by nodules also yielded phenolphthalein false‐positive reactivity for several years after nodule exposure. Nodules from leguminous plants contain a protein (leghemoglobin) which is structurally and functionally similar to hemoglobin. Testing of purified leghemoglobin confirmed this protein as a source of phenolphthalein reactivity. A scenario is presented showing how the presence of leghemoglobin from nodule staining can mislead investigators.     

正交试验优化霍山米斛总多糖提取工艺

目的 建立霍山米斛总多糖的最佳提取工艺。方法 依据2015年版《中华人民共和国药典》第一部中铁皮石斛多糖测定方法,通过单因素考察及正交试验研究提取温度、提取次数、提取时间、料液比对霍山米斛总多糖提取率的影响,采用苯酚-硫酸法测定其多糖含量。结果 霍山米斛的最佳提取工艺为：提取温度为100 ℃,提取2次,每次提取2 h,料液比为1∶800(g/mL)。结论 所优选的工艺简单、方便、准确,适用于霍山米斛总多糖的提取。