Improving Luminol Blood Detection in Forensics

The aim of this study was to develop chemical improvements to the original Weber protocol, in order to increase the intensity and time length of light emission and to eliminate false‐positive reactions. The intensity and duration of light were measured on serial blood dilutions using a plate reader chemiluminometer. Blood stains of various concentrations were impregnated in pure cellulose, dried, and luminol solution was added with/without the potential enhancers. An in silico study was also conducted, aiming to demonstrate the enhancing mechanism of hemoglobin denaturation using 8 M urea. The luminol blood detection test revealed important improvements after urea pretreatment or in the presence of monochloro‐triazinyl‐β‐cyclodextrin. This approach also eliminated the false‐positive reaction from sodium hypochlorite. These improvements could provide a higher sensitivity under particular circumstances such as old or washed blood stains, leading to a better localization for further DNA typing and higher quality photographic analysis.     

Recovery and detection of urea nitrate in traces

Urea nitrate (uronium nitrate, UN) is a powerful improvised explosive, frequently used by terrorists in the Israeli arena. It was also used in the first World Trade Center bombing in New York in February 1993. It is difficult to identify UN in postexplosion debris, because in the presence of water it readily decomposes to its original components, urea and nitric acid. A method for the recovery and detection of urea nitrate in traces is described. The residues are extracted with hot acetone, and the extract chromatographed on chromosorb G-HP. The eluent is analyzed by liquid chromatography mass spectrometry using atmospheric pressure chemical ionization (APCI). By applying this technique, we were able to identify urea nitrate in actual exhibits. It was found that UN can be also formed during the analytical procedure, by certain combinations of urea, nitrate ions, and a source of protons and, hence, the presence of the characteristic adduct ion does not necessarily indicate an "authentic" urea nitrate. Several solutions are suggested to overcome this ambiguity.     

固肾胶囊治疗实验性大鼠糖尿病肾病的研究

目的：观察固肾胶囊对大鼠糖尿病肾病（DN）的治疗作用，方法：采用单侧肾切除加链脲佐菌素注射法复制DN大鼠模型，随机分为模型组，开达（开博通＋达美康）组，固肾胶囊大，小剂量组，灌胃给药8周后分别测定其对大鼠肾质量，肾功能及尿白蛋白排泄量的影响，结果：固肾胶囊大，小剂量组肾质量，肾质量／体质量比值，尿素氮，肌酐，尿蛋白排泄量均显低于模型组（P＜0．05或P＜0．01），与开达组比较，各项指标差异无统计学意义，结论：固肾胶囊有抑制肾脏肥大，改善肾功能，减少尿蛋白的作用。     

The Estimation of Postmortem Serum Urea via the Ultrafiltration of Hemolyzed Blood

Postmortem serum urea has been demonstrated as an objective indicator for the forensic diagnosis of cause of death. However, samples used in postmortem biochemical analysis are always affected by hemolysis. To investigate whether hemolysis affects the biochemical analysis of urea and to explore the feasibility of using ultrafiltration to process hemolyzed blood samples, three different levels of hemolyzed blood samples were used to assess the influence of hemolysis on postmortem biochemical analysis of urea, and two ultrafiltration methods were used to process the hemolyzed blood samples. Bias% was used to assess the interference of hemolysis. Our results showed that heavy hemolysis had a significant influence on the biochemical analysis of urea. Both ultrafiltration methods in the present study could significantly reduce the interference of hemolysis, with the |bias%| of methods A and B decreasing from 69.74% ± 99.14% to 12.18% ± 7.23% and 10.77% ± 8.09%, respectively, compared to the original serum. After regression correction, there was no significant difference between the urea concentration in the ultrafiltrates of the two ultrafiltration methods and that in the original serum, which suggested that the postmortem serum urea concentration could be estimated by the corrected urea concentration in the ultrafiltrate. The current study also provided possible pretreatment methods for postmortem biochemical analysis of other biomarkers in hemolyzed blood samples of forensic practice.     

尿素氮、肌酐和尿酸死后生化学检测的法医学应用

死后生化学是法医鉴定中重要的检查手段。研究表明含氮化合物中尿素氮、肌酐、尿酸是临床上常用的生化学检测指标,其在法医死后生化学检测中也有重要的价值。本文就体内上述三者的特征及其在法医学中的研究及应用加以综述,以期为法医死后生化学分析提供参考。     

尿素中毒的检验

目的　建立了用气质联用法定量分析尿素的方法。　方法　采用传统滴定分析和气质联用定性定量检验对照分析。　结果　在 0 1μg～ 5 0 μg范围内 ,该方法有较好的线性 (r >0 9976 )。　 结论　该方法准确、快速 ,适用于尿素的定量分析     

Surface Modification for the Collection and Identification of Fingerprints and Colorimetric Detection of Urea Nitrate

Glass surfaces were modified with a combination of dyes and reagents to allow for the potential simultaneous recording of a detailed fingerprint and the detection of the explosive urea nitrate (UN), as a proof of principle of surface modification for simultaneous linking of identity to manipulation of explosives. By coating microscope slides with 9,10‐diphenylanthracene (DPA), p‐dimethylaminobenzaldehyde (p‐DMAB) and p‐dimethylaminocinnamaldehyde (p‐DMAC), a colorimetric change was observed in the presence of UN, while revealing a fingerprint with enough resolution to isolate at least 10 minutiae. This is the first step in creating point‐of‐care devices capable of detecting low concentrations of explosives and drug metabolites and connecting them to a fingerprint.     

Structure elucidation of dyes that are formed in the colorimetric detection of the improvised explosive urea nitrate

Urea nitrate (uronium nitrate, UN) is a powerful, improvised explosive that can be easily made from urea and nitric acid. It is considered the most frequently used, illegal explosive in the Israeli arena, which is responsible for the loss of more than a hundred lives in terrorist incidents. Urea nitrate is a colorless, crystalline substance that looks very much like sugar. A sensitive color test for UN was developed recently. It is based on the formation of a red dye in the reaction between p-dimethylaminocinnamaldehyde and UN under neutral conditions. A similar reaction with p-dimethylaminobezaldehyde produces a yellow dye. The two dyes have been synthesized, and their structures determined by X-ray crystallography. Both dyes are protonated Schiff bases, prevailing in the crystal in a quinoid form. They are identical to the compounds, which are obtained in the colorimetric detection of urea with the same reagents, under strong acidic conditions, whose structures have been postulated in the literature, but never fully proved experimentally.     

褐藻多糖硫酸酯治疗慢性肾功能不全临床观察

目的 观察褐藻多糖硫酸酯(海昆肾喜胶囊)治疗慢性肾功能不全(chronic renal insufficiency,CRI)的临床疗效.方法 将42例CRI患者按照性别、年龄、原发疾病、血清肌酐(serum creatinine,SCr)、血尿素氮(blood urea nitrogen,BUN)、肌酐清除率(crea...