肌肉电导率和pH两指标联用推断死亡时间

目的探讨肌肉浸渍液电导率(electrical conductivity,EC)、pH两指标联用在PMI推断上的意义。方法 SD大鼠处死后,保存在25℃环境中,于不同PMI提取大鼠后肢肌肉制备匀浆液,测定浸渍液EC和pH。分析EC、pH两指标联合使用推断PMI的意义。结果 EC、pH两指标随PMI均呈现阶段性变化:1d内,pH明显下降,EC无明显变化;2~3d,EC、pH均快速增大;4~10d,EC继续增大,而pH变化不明显。EC、pH联合使用,有助于划分PMI时段,以及特定时段内指标的优化:1d内,选择pH最佳,2~3d,EC、pH联用最佳,4~10d,选择EC最佳。结论 EC、pH联用有助于提高PMI推断的准确性。     

Macroscopic observations of the effects of varying fresh water pH on bone

Little is known about the decomposition of remains in aquatic environments of varying pH, and even less is known about the specific effects of these environments on bone. Bovine bones were placed in solutions of pH 1, 4, 7, 10, and 14 and observed over a period of 1 year. All solutions eventually removed or dissolved the soft tissues from the external surface of the bone. The pH 7 and pH 10 solutions had little effect on the bone, but the other solutions affected the bone to varying degrees. Extreme pH levels were the most destructive, while more moderate pH levels had lesser but significant and interesting effects. Empirical data on postmortem aquatic changes may be extremely useful in forensic contexts for both improving time since death estimates and also for providing better information to underwater recovery experts thereby potentially increasing the quantity and quality of remains recovery.     

样品成份对“咖啡环”法DNA检测的影响

目的调查样品中常见成份对"咖啡环"法DNA检测的影响。方法将含有不同浓度SDS、Na Cl等的DNA-EB滴加到载玻片上,室温自然蒸发,用凝胶成像系统观察荧光沉积形貌(Deposition Pattern,DP)、计算积分光密度(Integrated Optical Density,IOD),分析量效关系。结果低浓度非DNA成份存在时,DP仍以环状沉积为主,但有年轮环、放射纹等成份特异性细微差异。浓度高时,DP因成份而异,可为环+散在光点型(Na Cl)、中央光斑+弱小环型(SDS)、同心或年轮状多环型(Triton X-100)、环+斑点型(H^+)等。非DNA成份对DNA含量估计有不同程度影响,但估计值多数在0.5~2倍以内。结论样品成份对DNA的DP和IOD均有影响,但不影响DNA含量的粗略估计,且能提供样品纯度和残留物信息。     

多温度下死后心血pH值随时间变化的三维拟合函数研究

目的 探讨通过测量多温度条件下家兔右心血液pH值进行死亡时间推断的可行性.方法 48只家兔随机分为6组,空气栓塞法处死后于10℃、15℃、20℃、25℃、30℃和35℃的不同死亡时间点采集右心血液;用PB-10型pH仪测量样本pH值;SPSS统计软件进行回归分析;MATLAB软件进行数学分析.结果 各温度组右心血液pH值变化与死亡时间呈高度相关(R2=0.974 ～0.982);获得拟合的曲面方程.结论 利用插值函数拟合pH值与死亡时间的曲面方程可进行温度变化条件下的死亡时间推断.     

Dynamics of Ninhydrin‐Reactive Nitrogen and pH in Gravesoil During the Extended Postmortem Interval

Estimating the postmortem interval of skeletal remains is difficult, as few tools exist to do so. To address this problem, we conducted a field experiment to measure the chemistry of swine (Sus scrofa domesticus Linnaeus) gravesoil after 1 year and 3 years postmortem. Carcasses were placed on the soil surface of a pasture during June in a cold (Dfa) climate. Significant (p < 0.05) increases in ninhydrin‐reactive nitrogen, pH, total nitrogen, and nitrate in gravesoil were detected 1 year postmortem. Significant differences in gravesoil chemistry were not detected 3 years postmortem. These observations coincided with gaps in plant growth 1 year postmortem and the development of lush vegetation 3 years postmortem. We conclude that these phenomena can be used to assist the decision‐making process regarding the allocation of resources during the early stages of a death investigation.     

测量大鼠死后骨骼肌pH值推断早期死亡时间实验研究

目的利用KNIpHE电极对大鼠死后不同时间骨骼肌pH值进行测定,探讨死后骨骼肌pH值与早期死亡时间(PM I)之间的关系,为利用该种电极在现场快速准确推断死亡时间取得实验依据。方法36只大鼠分为12组,每组3只,分别于死后即刻和死后1,2,3,4,6,8,10,12,16,20,24h取材,制备匀浆后,采用美国Thermo O rion公司210型便携式酸度计配套KNIpHE7120BN电极直接测量pH值;采用南京建成生物工程研究所研制的试剂盒用分光光度法检测乳酸(LA)浓度、肌酸激酶(CK)活性。结果①大鼠死后12h内,股四头肌pH值随PM I延长而逐渐下降,二者之间呈负相关;②大鼠死后12h内,股四头肌LA浓度随PM I延长而上升,与pH值呈负相关;③大鼠死后24h内,股四头肌CK活性随PM I延长而逐渐增强,二者之间呈正相关;④以12h内pH值数据对PM I进行一元线性回归分析,回归方程为:PM I=115.499-17.7pH(R2=0.662,P<0.01,R2为决定系数)。结论利用Thermo O rion KNIpHE电极测定骨骼肌pH值推断早期死亡时间具有较好的应用前景。     

抗原修复法和固定液pH值对切创皮肤免疫组化染色的影响

目的比较不同抗原修复方法对不同pH混合福尔马林固定液固定的切创皮肤的免疫组化染色效果。方法小鼠皮肤切创后3d取材,分别用pH为5.0、6.0、7.0、8.0、9.0的混合4%福尔马林固定液固定,经高压锅、微波、胰蛋白酶、胃蛋白酶、微波+胰蛋白酶法对抗原修复,观测caspase-3,caspase-6,caspase-7,IL-8,IL-10的免疫组化染色(SABC法)效果。结果热修复法阳性细胞率高于蛋白酶修复法,高压修复法阳性细胞率略高于微波修复;高压修复法的脱片现象高于微波修复,胃蛋白酶修复脱片高于胰蛋白酶修复;微波+胰蛋白酶双修复法阳性细胞率最高,不发生脱片现象;固定液pH值为7.0和8.0时,阳性细胞率最高,染色效果最好。结论pH7.0和8.0混合福尔马林固定液固定的切创皮肤,经微波+胰蛋白酶法修复抗原,免疫组化染色效果最佳。     

酶促试纸条测定唾液中乙醇含量的研究

生化酶促反应使试纸与含有乙醇的液体接触后显色,根据颜色的不同确定被测液体中的乙醇含量,依此研制出酶促试纸条。通过志愿者实验,同时收集血液和唾液, 比较酶促试纸条测定唾液中乙醇含量与顶空气相色谱检测血醇和唾醇的结果。考察酶促试纸条的影响因素。通过提高缓冲液浓度至0.6mol/L和减少乙醇氧化酶的量改进酶促试纸条,使相同乙醇浓度的酸碱两种唾液间的差异显著缩小。所研制的酶促试纸条具有成本低、操作简便、快速的优点。     

Assessment of the Effects Exerted by Acid and Alkaline Solutions on Bone: Is Chemistry the Answer?

The treatment of corpses with extremely acid or basic liquids is sometimes performed in criminal contexts. A thorough characterization by chemical analysis may provide further help to macroscopic and microscopic analysis; 63 porcine bone samples were treated with solutions at different pH (1–14) for immersion periods up to 70 days, as well as in extremely acidic sulfuric acid solutions (9 M/18 M) and extremely basic sodium hydroxide. Inductively coupled optical emission spectrometry (ICP‐OES)/plasma mass spectrometry (ICP‐MS), Fourier transform infrared spectroscopy (FT‐IR), energy dispersive X‐ray analysis (EDX), X‐ray powder diffraction (XRPD), and scanning electron microscopy (SEM) showed that only the sulfuric acid solution 18 M was able to completely dissolve the sample. In addition, chemical analysis allowed to recognize the contact between bone and substances. Hydrated calcium sulfate arose from extreme pH. The possibility of detecting the presence of human material within the residual solution was demonstrated, especially with FT‐IR, ICP‐OES, and EDX.     

健胃冲剂治疗大鼠反流性食管炎的机制研究

目的 探究健胃冲剂治疗大鼠反流性食管炎的机制。方法 复制反流性食管炎大鼠模型，将术后恢复较好的大鼠随机分为模型组，阳性对照组（雷贝拉唑钠肠溶片），健胃冲剂高、中、低剂量组，另设正常对照组，每组10只大鼠。各组末次给药24 h后，立即自胃食管交界上0.5 cm处向咽喉部截取长约1.5 cm的食管组织，测定其pH值，并观察各组大鼠食管黏膜病理形态变化。结果 与正常组比较，模型组大鼠食管下段黏膜pH值显著降低（P<0.01），食管下段大体标本肉眼病理评分显著升高（P<0.01），显微镜下病理评分（反向评分）显著降低（P<0.01）。与模型组比较，阳性对照组，健胃冲剂高、中、低剂量组pH值显著升高（P<0.05），大体标本肉眼病理评分显著降低（P<0.01），显微镜下病理评分显著升高（P<0.05，或P<0.01）。健胃冲剂高剂量组在升高pH值和食管黏膜显微镜下病理评分方面优于阳性对照组（P<0.05）。光镜下正常组大鼠食管黏膜组织结构正常；模型组大鼠黏膜上皮细胞层内出现较多炎性细胞浸润，鳞状上皮增生，严重者出现黏膜糜烂；健胃冲剂高、中、低剂量组较模型组均明显改善；雷贝拉唑组改变与健胃冲剂低剂量组基本相同。结论 健胃冲剂能改善反流性食管炎大鼠的组织病理形态，其作用机制与降低模型大鼠食管下段黏膜的酸度有关。