Spectra interference between diquat and paraquat by second derivative spectrophotometry

A rapid and accurate method, combining solid-phase extraction and second-order derivative spectrophotomety approaches, is developed for the simultaneous determination of diquat (DQ) and paraquat (PQ) in blood, tissue and urine samples. Supernatant resulting from the precipitation of protein (with trichloroacetic acid) in plasma and tissue or Amberlite IRA-401 resin treated urine are passed through a mini-column packed with Wakogel gel (Silica gel). Analytes are then eluted with a non-organic solvent, 0.2mol/l HCl solution containing 2mol/l NH(4)Cl. UV spectrum of the eluent in 220-350nm range provides effective screen to detect the presence of DQ and/or PQ. In the presence of DQ or PQ alone, the analyte present is quantitated by conventional zero- or second-order derivative spectrophotometry. The calibration curve in the 0.1-5.0mg/l range for either analyte obeys Beer's law. When both DQ and PQ are present, their concentrations are determined by the peak amplitudes of their respective second-derivative spectra after the addition of alkaline dithionite reagent. Interference is negligible when the DQ/PQ concentration ratio is within the 5.0-0.2 range.Using a 2-ml of sample size, the detection limits for DQ and PQ in plasma are 0.02 and 0.005mg/l. The corresponding detection limits for urine samples (10ml sample size) are 0.004 and 0.001mg/l. Recoveries of DQ and PQ in triplicate plasma and urine samples spiked with 0.5mg/l of analytes are 93 and 85%. The precision of the proposed method resulting from triplicate study of spiked urine samples varies from 3.2 to 4.6% at 0.5mg/l of DQ and PQ, respectively.     

The use of the LightCycler for the detection of Y chromosome SNPs

A novel methodology based on PCR monitoring on-line with fluorescent formats using the LightCycler for Y chromosome SNP typing is proposed. The main advantages of the system are the time necessary for the analysis (which is around 20 min), the robustness and the accuracy of the method and especially its sensitivity, which permits the detection of the male component in male-female mixtures up to 1:300 for some of the SNPs.Singleplexes of four different SNPs (M9, sY81, SRY-1532 and SRY-2627) as well as two duplexes (M9 and sY81 on the one hand and SRY-1532 and SRY-2627 on the other) were efficiently implemented. A simultaneous amplification and analysis of the four SNPs is also possible. It seems difficult with the current methodology to implement more than a quadruplex.     

A protocol for the forensic analysis of condom and personal lubricants found in sexual assault cases.

In sexual assault cases, lubricant trace evidence may supplement biological evidence, or may be the primary physical evidence where biological evidence is unavailable. This study considered a total of 50 lubricants from condoms and personal lubricant products available in Australia. Differentiation of the samples was attempted using fluorescence examination, Fourier transform infrared spectroscopy (DRIFTS), gas chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, and pyrolysis gas chromatography-mass spectrometry. Eleven of the samples were uniquely identified by the analysis scheme, while the remainder of the samples were separated into nine groups. As a result of this study, a recommended protocol for the detection and analysis of an "unknown" biological swab was produced.     

低氧和氧化应激中 NO介导培养神经元损伤机理的实验研究

目的探讨低氧、氧化应激中一氧化氮（NO）和氧自由基之间关系及其对培养神经元的损伤机理。方法对培养的新生大鼠神经细胞分别进行低氧、H2O2氧化应激处理和超氧化物歧化酶（SOD）抗氧化应激处理,用比色法等检测培养上清液中NO、丙二醛（MDA）、乳酸脱氢酶（LDH）和SOD含量变化指标。结果与对照组比较,低氧组和H2O2组的NO、LDH、MDA含量均显著增高,SOD含量显著降低,NO与SOD含量变化呈负相关关系。预先给予终浓度为200U/ml的SOD处理,可使神经细胞的NO、LDH和MDA释放量明显减少。各组间NO含量与LDH、MDA含量呈正相关关系。结论低氧、氧化应激促使神经元NO产生增多,NO有增加氧自由基对神经细胞的损伤作用。SOD具有清除氧自由基和减轻NO对神经元的损伤作用。     

家兔死后眼玻璃体液锌、镍含量与 PMI关系的研究

目的寻找一种精确推定PMI的方法。方法应用电感耦合等离子体质谱（ICP－MS）,检测了家兔死后96小时内眼玻璃体液锌、镍元素含量,探讨其与PMI的相关性。结果家兔死后24h内眼玻璃体液锌、镍元素含量与PMI显著相关,可作为推定早期PMI的参考指标,其二项式回归方程分别为y=0.1404x2－1.3351x＋3.8298（R2=0.9202）、y=0.0043x2－0.0596x＋0.2665（R2=0.9103）。结论家兔眼玻璃体液中Zn、Ni元素含量变化是推定早期PMI的参考指标之一。     

挤压综合征大鼠血清酶浓度变化的初步研究

目的观察挤压伤大鼠血清肌酸激酶(CK)、肌酸激酶心肌同功酶(CK-MB)浓度的变化,阐明肢体挤压伤大鼠早期是否存在心脏损伤。方法复制挤压伤大鼠动物模型,全自动生化分析仪检测血清CK、CK-MB浓度的变化。结果挤压伤后12h,血清CK、CK-MB浓度显著升高,并持续48h以上。结论肢体挤压伤早期可能有心脏损伤的存在。     

Occupational safety and health in Poland in the 1990s: A regulatory system adapting to societal transformation

The societal transformation underway in Poland createda fundamental challenge to the occupational health and safety system, as the ideological and administrative principles on which it was founded vanished along with the communist-dominated regime. This paper examines the regulatory reform in Poland during the 1990s: its structural elements, implementation record and future prospects. Drawing on five case studies of privatized firms, a mailed questionnaire, and policy and institutional analysis, we find that Poland had considerable success in developing an effective regulatory system for managing occupational health hazards in privatized sector while also achieving considerable socioeconomic progress. The fundamental legitimacy of the regulators and regulatory process, the availability of information about firms and regulatory intents, and the capacity for case-specific decision making, are among the key explanatory factors. The case-specific implementation in Poland is consistent with models advocated by several authors in relation to other industrialized European economies (termed variously as negotiated compliance, tit-for-tat, cooperation-deterrence), despite a uniquely Polish context related to the continuing legacy of the communist era. The study also shows how in Poland a good fit between regulatory institutions and policies on the one hand, and their social context on the other hand, contributes to the effectiveness of the regulatory system.     

Artifactual injuries of the larynx produced by resuscitative intubation

Over a period of 9 months we examined a series of 50 deaths due to natural and unnatural causes in which there had been endotracheal intubation and chest compression during resuscitation at the scene or in the emergency department shortly before death. In 37 of 50 cases (74%) there were airway injuries directly resulting from the intubation procedure which we documented using a standardized protocol and photography. Specific airway injuries, ranging from petechiae to contusions, included oral injury (28%), posterior pharyngeal injury (16%), epiglottic injury (22%), piriform recess injury (12%), laryngeal and tracheal mucosa injury (64%), strap muscle hemorrhage (14%), and cutaneous injury of the neck (4%). In addition, we recorded the presence of facial (6%) and conjunctival petechiae (21%) and attributed these changes to resuscitative chest compression. No cases had associated fractures of the hyoid or thyroid cartilage. Based on our findings, we conclude that resuscitative intubation can cause artifactual injury that may mimic inflicted injuries caused by neck compression, including strangulation and neck holds.