Relationship between Water Temperature and Floating Time of Aquatic Cadavers / 法医学杂志

OBJECTIVES@#To study the relationship between water temperature and floating time of aquatic cadavers, providing a reference for more precise positioning and searching for floating corpses.@*METHODS@#The floating model of guinea pig after drowning at 17-30 ℃ was established, and the floating times of carcasses were recorded. The collected data of 32 floating corpse cases in the Pearl River were sorted out and analyzed according to the floating time of corpses corresponding to each degree of water temperature. The relationship models between water temperature and the floating time of guinea pig carcass, and between that and the floating time of real cases were established.@*RESULTS@#The floating time of the cadaver was negatively correlated with water temperature. The power function fitting equation of the relationship between floating time and water temperature of guinea pig carcass was y=1×1015x-10.530(R2=0.871, P<0.01), and the power function fitting equation of the relationship between corpse floating time and water temperature was y=3×106x-3.467(R2=0.802, P<0.01).@*CONCLUSIONS@#It is found that average floating cadaver time has a power function with water temperature, which provides a reference for locating floating cadavers and establishing search models.

Assisting Role of Pulmonary Hypostasis Phenomenon in Diagnosis of Drowning / 法医学杂志

OBJECTIVES@#To study the phenomenon of pulmonary hypostasis in corpses of various causes of death, and to explore the potential value of this phenomenon in assisting forensic pathological diagnosis of drowning.@*METHODS@#A total of 235 cases with clear cause of death through systematic autopsy were collected from January 2011 to June 2021 in Guangzhou. According to the location of body discovery, the cases were divided into the water body group (97 cases) and the non-water body group (138 cases), and the water body group was further divided into the water drowning group (90 cases) and the water non-drowning group (7 cases). Non-water body group was further divided into the non-water drowning group (1 case) and the non-water non-drowning group (137 cases). Three senior forensic pathologists independently reviewed autopsy photos to determine whether there was hypostasis in the lungs. The detection rate of pulmonary hypostasis was calculated.@*RESULTS@#The detection rate of pulmonary hypostasis in the water drowning group (90 cases) was 0, and the negative rate was 100%. The detection rate of pulmonary hypostasis in the water non-drowning group (7 cases) was 100% and the negative rate was 0. The detection rate of pulmonary hypostasis in the water body group and in the non-water body group (after excluding 2 cases, 136 cases were calculated) was 7.22% and 87.50%, respectively. There were statistically significant differences in the detection rate of pulmonary hypostasis between water body group and non-water body group, and between water drowning group and water non-drowning group (P<0.05).@*CONCLUSIONS@#The disappearance of pulmonary hypostasis can be used as a specific cadaveric sign to assist in the forensic pathological diagnosis of drowning.

Simultaneous determination of flavones and saponins of Rhizoma Anemarrhenae by HPLC-DAD-ELSD / 中国中药杂志

This study is to establish an HPLC-DAD-ELSD method for simultaneous determination of 5 flavones and saponins in Rhizoma Anemarrhenae including neo-mangiferin, mangiferin, timosaponin B II, timosaponin B III and timosaponin A III. Samples were analyzed on a Merck Purospher STAR column(4.6 mm x 250 mm, 5 μm). The mobile phase consisted of acetonitrile( A) and 0. 1% formic acid (B) with gradient elution at a flow rate of 1.0 mL · min(-1). The column temperature was set at 40 °C. The DAD detector wavelength was set at 254 nm. The ELSD conditions were as follows: the nebulizing gas flow rate was 2.0 L · min(-1) and temperature of drift tube was 105 °C. The volume was 10 μL. The five compounds were well separated with good linear correlations. The mean recoveries were between 102.0%-104.0%. This method was quick and reliable which provides a foundation for quality control of R. Anemarrhenae.