泥土中植物花粉的提取与检验

目的建立泥土中植物花粉的提取和检验方法。方法用去二甲苯、18%盐酸溶液处理提取泥土中的花粉 ,然后用扫描电镜进行检验。结果从不同的泥土中检出不同花粉。结论本方法能有效分离提取泥土中花粉。对其它混合物中花粉的提取有参考价值。本文介绍一种泥土中花粉提取的简捷方法 ,以及利用扫描电镜 /能谱仪对提取的植物花粉进行检验的方法。     

仔猪睾丸组织体外培养方法的建立

以30日龄仔猪睾丸组织块为培养对象,应用飞利普TECNAI10电子显微镜对培养前后的生精细胞类别进行了观察,对培养后的组织块进行生精细胞分化程度鉴定,建立了仔猪睾丸组织生精细胞爬片体外培养模型。培养前后电镜观察及HE染色结果显示,培养前细胞种类主要有2种:支持细胞和精原细胞,有少数几个初级精母细胞;培养第20 d的睾丸组织块HE染色观察到3个精子细胞,电镜观察到2个精子细胞。证实,在没有添加睾酮的情况下,此培养体系能够提供睾丸组织块生精细胞分化所需要的条件,使非精子细胞类生精细胞减数分裂为精子细胞。     

胚兔牙囊发育生物行为的组织形态学观察

研究胚兔的牙囊发育生物行为与人的牙囊发育是否相似 ,为人口腔疾病的研究提供模拟实验动物模型 ,采用光镜、电镜及激光扫描共聚焦显微镜对 4 3只胚兔的牙囊发育过程进行形态学观察。结果显示 ,牙囊来源于外胚间质 ,通过胚胎诱导形成牙支持组织 ,分化产生成牙骨质细胞、成骨细胞、成纤维细胞 ,形成牙骨质、固有牙槽骨、牙周韧带及其基质 ,对牙齿发育阶段具有保护和稳定作用 ,调控未来形成的牙周结构 ,在早期发育阶段首先出现 ,与人牙囊发育基本相似 ;最终牙囊在牙冠的顶部形成索引带 ,诱导继承牙萌出 ,在牙冠的根部形成牙支持组织 ,一部分牙囊细胞有程序性细胞死亡 ,以维持牙囊发育期内环境的生理平衡     

中毒死者体内毒鼠强的GC/MS-SIM分析

一 1 9岁男子赌气吞服一白色粉末 ,1 0min后口鼻流血、抽搐 ,迅速送医院 ,经催吐、透析等方法治疗 5天后死亡。根据中毒症状和经验怀疑为毒鼠强中毒。用GC/NPD检验肝中毒鼠强有干扰。改用GC/MS -SIM法分析 ,心血、肝和胃组织中全部检出毒鼠强 ,浓度分别为 0 5 1 μg .mL- 1、0 4 5 μg .g- 1和 0 33μg .g- 1,和文献结果在同一水平。GC/MS -SIM对复杂检材中低含量毒鼠强测定具有更高的选择性 ,也具有较高的灵敏度 ,同时进一步证实毒鼠强排泄较慢 ,经过较长时间后在体内分布比较均匀     

Combined Collection and Analysis of Inorganic and Organic Gunshot Residues

Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid^® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.     

Sequencing of intersecting lines by combined lifting process and scanning electron microscopy

The chronological order in which two intersecting writing or typed strokes were made can be determined for several combinations of writing media by scanning electron microscope (SEM) examination, a lifting and transfer technique using Kromekote paper, or a combination of the transfer technique followed by SEM examination of the remaining material in the intersection. When non-destructive examination cannot provide unambiguous determination of sequence, judicious choice by the document examiner of which technique to use for a given combination of writing media and paper type can be made using known characteristics of the materials involved. The range of line-crossings which can be reliably sequenced is greater using a combined transfer and SEM technique than when the examination is limited to either technique alone.     

Assessment of Maceration Techniques Used to Remove Soft Tissue from Bone in Cut Mark Analysis

Maceration techniques employed in forensics must be effective without compromising the bone's integrity and morphology, and prevent destruction of evidence. Techniques must also be fast, safe, easily obtainable and inexpensive; not all techniques currently employed are appropriate for forensic use. To evaluate the most suitable approach, seven techniques including current and new methodologies were applied to fresh, fleshed porcine ribs exhibiting cut marks. A sample size of 30 specimens per technique was examined under scanning electron microscopy at the cut mark and the surrounding uncompromised regions; a scoring system of effectiveness was applied. The previously unpublished microwave method fared best for bone and cut mark preservation. Sodium hypochlorite destroyed cut marks, and was deemed unsuitable for forensic analysis. No single technique fulfilled all criteria; however, this study provides a benchmark for forensic anthropologists to select the most appropriate method for their situation, while maintaining the high standards required by forensic science.     

兔急性心肌缺血脱氢酶电镜—细胞化学变化的动态观察

为了研究急性心肌缺血脱氢酶变化的规律性，本文应用电镜酶细胞化学技术，通过结扎５０只家兔冠状动脉左前降支，观察心肌缺血后０．２５、０．５、１、１．５、２、４、６、１２、２４、３６、７２小时ＳＤＨ和ＬＤＨ的变化。结果显示：心肌缺血０．５小时后，ＳＤＨ和ＬＤＨ活性开始下降。同时伴有致密体的形成和超微结构的改变。随着缺血时间的延长，酶活性下降更加明显，最后消失。     

理性分析与法律规制：“测谎仪”在刑事司法活动中运用

“测谎仪”以特殊作用机理在刑事司法活动中发挥着重要的作用。通过对世界各国对“测谎仪”及测谎技术的考量，不难发现各国对“测谎仪”的使用存在不同的看法．这也加剧对“测谎仪”适用的争议。针对司法实践中对“测谎仪”的诘问，客观、理性的做法是：加强对“测谎仪”使用的法律规制．使其运用规范化、科学化、法律化。     

挤压损伤—挤压综合征的病理,生理,生化改变

本文参阅国内外有关挤压损伤一挤压综合征的文献，着重从生理、生化、病理方面阐述挤压损伤一挤压综合征发生发展规律，法医诊断挤压综合征的常规方法及研究新进展，为法医工作者今后进一步研究挤压综合征提供了一个较全面的资料。