小鼠骨骼肌细胞核DNA降解与死亡时间的关系

目的　监测小鼠死后骨骼肌核内DNA降解的情况 ,探讨死后细胞核DNA降解的一般规律。方法　建立小鼠死亡模型 ,在死后 72h内 ,以 12h的间隔取骨骼肌样本进行单细胞凝胶电泳 ,在荧光显微镜下测量彗星图像 ,并作统计学分析。结果　机体死后 ,骨骼肌细胞在电泳图像上出现了明显的彗星形拖尾 ,L/W比值随死亡时间而逐渐增大 ,二者呈一定的线性关系。结论　单细胞凝胶电泳技术可以应用于早期死亡时间推断。     

毒鼠强诱导细胞DNA损伤的彗星电泳检测

目的　研究毒鼠强对小鼠淋巴细胞和脑细胞DNA的损伤作用。方法　分离健康小鼠的淋巴细胞和脑细胞 ,以彗星电泳的方法测定不同浓度毒鼠强处理后的细胞DNA损伤。结果　 1/2 0～ 1/2LD50 剂量组的毒鼠强均可引起淋巴细胞和脑细胞不同程度的DNA损伤 ,与对照组呈极显著性差异 (P <0 0 0 1)。结论　毒鼠强引起细胞DNA断裂损伤 ,并呈现明显的剂量 -效应关系。     

灌服毒鼠强诱导大鼠细胞DNA的损伤研究

目的研究毒鼠强体内染毒后,毒鼠强对大鼠脑细胞、心肌细胞、淋巴细胞DNA的损伤作用。方法选择健康Sprague-Dawley大白鼠20只,分成5组,每组4只,采用灌胃方法使大鼠毒鼠强体内染毒,按0.2,0.1,0.05,0.01mg·kg-1制作大鼠毒鼠强中毒模型,并以灌服生理盐水的健康大鼠为对照,分离实验大鼠的淋巴细胞、心肌细胞和脑细胞,用彗星电泳的方法测定不同浓度毒鼠强中毒后的细胞DNA损伤。结果0.2,0.1,0.05,0.01mg·kg-1剂量组的毒鼠强均可引起大鼠的淋巴细胞、心肌细胞和脑细胞DNA损伤,均与对照组差异有显著性(P<0.01)。结论毒鼠强诱导体内细胞DNA损伤可能是毒鼠强毒性作用机制之一。     

GC Analysis of Black Gel Pen Ink Stored under Different Conditions

In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, the volatile components of gel ink were determined and the gel ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to express the relationship between the content of volatile gel ink components and the age of gel ink entries stored under natural and UV‐induced aging conditions. The correspondence between the natural and UV‐induced aging conditions was also established. The experimental results showed that GC was useful in the analysis of black gel ink and applicable for determining the relative age of gel ink entries under certain conditions.     

大孔树脂联合Sephadex LH-20葡聚糖凝胶纯化蜂胶总黄酮工艺研究

目的 优选大孔树脂联合Sephadex LH-20葡聚糖凝胶分离纯化蜂胶总黄酮的最佳工艺参数.方法 采用硝酸铝-醋酸钾比色法定量,通过比较9种大孔吸附树脂对蜂胶总黄酮的吸附率和解吸率,筛选出最佳大孔吸附树脂型号,通过动态吸附与解吸试验优选大孔树脂最佳纯化工艺参数,采用Sephadex LH-20葡聚糖凝胶进一步纯化.结果 优选大孔树脂型号为HPD-722型.最佳纯化工艺:上样液浓度2.5 mg/mL,比上样量0.43 g/g(药材/湿树脂),上样容积流量为每小时2倍床体积(bed volume,BV),径高比1:9;先以30％乙醇3 BV除杂,再用80％乙醇4 BV洗脱,洗脱容积流量1 BV/h,洗脱液浓缩、干燥,得蜂胶总黄酮Ⅰ,纯度为41.42％;取蜂胶总黄酮Ⅰ1.2 g,用少量甲醇超声溶解,上样于Sephadex LH-20层析柱,以甲醇洗脱,洗脱流速0.75 mL/min,7.5 mL作为一个流份收集,以三氯化铝为显色剂,聚酰胺薄层色谱检识各流份,合并、干燥得蜂胶总黄酮Ⅱ,纯度为68.48％.结论 HPD-722型大孔吸附树脂联合Sephadex LH-20葡聚糖凝胶可有效纯化蜂胶总黄酮.     

Comparison between Temperature Gradient Gel Electrophoresis of Bacterial 16S rDNA and Diatom Test for Diagnosis of Drowning

When a body is discovered in water, it is difficult to conclude whether the cause of death was drowning, even today. Although diatom testing by the digestive method is classical, we hypothesized that aquatic bacteria, as well as diatoms, might be detected in drowned bodies, and conducted temperature gradient gel electrophoresis (TGGE)‐targeting 16S rDNA. DNA was extracted from the site water, and from heart blood and liver samples from 27 bodies concluded as drowning deaths by autopsy and subjected to TGGE after amplification of 16S rDNA by polymerase chain reaction. We observed whether the feature point of each 16S rDNA from the site water and blood or liver samples matched. Considerably higher correspondence was observed in drowned bodies, and the rate was higher than that achieved with the digestive method. Moreover, TGGE is safer than the digestive method. Our study suggests that this method can aid diagnosis of drowning.     

Blast Suppression Foam,Aqueous Gel Blocks,and their Effect on Subsequent Analysis of Forensic Evidence*

In addition to having blast mitigation properties, aqueous foam concentrate AFC-380 blast suppression foam is designed to capture aerosolized chemical, biological, and radioactive particles during render-safe procedures of explosive devices. Exposure to aqueous environments and surfactants may negatively affect forensic evidence found at the scene, but the effects of AFC-380 foam and aqueous gel on the preservation and subsequent analysis of forensic evidence have not previously been investigated. Sebaceous finger and palm prints and DNA samples on paper, cardboard, tape, and various metal and plastic items, along with hairs, carpet and yarn fibers, and inks and documents, were exposed to AFC-380 foam. Similar mock evidence was also exposed to a superabsorbent gel of the type found in aqueous gel blocks used for shrapnel containment. Exposure to foam or aqueous gel was associated with a dilution effect for recovered DNA samples, but quality of the samples was not substantially affected. In contrast, exposure to AFC-380 foam or gel was detrimental to development of latent finger and palm prints on any substrate. Neither the hair nor the fiber samples were affected by exposure to either the foam or gel. Indented writing on the document samples was detrimentally affected by foam or gel exposure, but not inks and toners. The results from this study indicate that most types of forensic evidence recovered after being exposed to aqueous gel or blast suppression foam can be reliably analyzed, but latent finger and palm prints may be adversely affected.     

绵羊卵母细胞的差异蛋白质组学研究

为了研究绵羊卵母细胞成熟过程中蛋白质的表达模式,以期在蛋白质水平探索绵羊卵母细胞成熟的分子机制,将采用双向凝胶电泳技术获得的2-DE图谱经PDQuest8.0分析并找出差异蛋白斑点后,对差异蛋白斑点进行高效液相色谱串联离子阱质谱分析。结果显示,GV期和MⅡ期卵母细胞2-DE图谱之间存在13个表达差异明显的蛋白斑点;4个蛋白斑点的质谱检测结果较为理想,对应3种不同的蛋白质,分别为截短的VP2、苹果酸脱氢酶、谷胱甘肽转移酶M3;其中截短的VP2、苹果酸脱氢酶在卵母细胞成熟过程中表达量下调,谷胱甘肽转移酶M3在卵母细胞中大量表达并且表达量上调。结果表明,绵羊卵母细胞成熟过程中,细胞的mRNA合成和表达水平以及糖代谢水平可能降低,细胞的抗氧化和解毒能力可能提高。     

ASE和GPC方法检验非苯二氮卓类催眠药

目的建立生物样品中4种非苯二氮卓类新型催眠药的快速溶剂萃取-凝胶色谱检验方法。方法生物样品采用快速溶剂萃取,凝胶色谱净化,GC／NPD检验。结果4种新型催眠药的平均回收率均在83％以上,检测限为0．05μg·mL-1～0．1μg·mL-1。结论该方法可满足实际检案的需求。     

人精浆SDS-聚丙烯酰胺梯度凝胶电泳谱型研究

本文采用SDS-聚丙烯酰胺梯度凝胶电泳(SDS-PAGGE)研究了102例中国正常男子精浆蛋白的电泳谱型,得到了具有精液特征性的,可与人阴道液、唾液、初乳及血清进行鉴别的人精浆蛋白电泳谱型,并可作为精斑的确证。另发现一种-83kd 变异型。频率为8. 82±2. 81%。提高了精斑的个人识别机率,在实际应用中取得了初步成效。