Environmental Risk Assessment of Chemical Projects——A Case Study of a Polystyrene Production Project

Taking a polystyrene production project as an example, according to Technical Guidelines for Environmental Risk Assessment of Con- struction Projects （HJ/T169-2004）, we firstly identity the risk of substances and production process to determine the major source of danger, and then conduct source analysis and consequence prediction of the maximum credible accident, finally assess the environmental risk of the project and propose main risk management measures. The results reveal that the environmental risk of the project is acceptable, and it is suggested that some dsk prevention and mitigation measures as well as contingency plans should be established.

Quantitative Analysis of Kruppel‑Like Factor 5‑Related Messenger RNA Transcripts in Ischemic Myocardium for Discrimination of Death Causes

Background:Accumulated studies have demonstrated that Kruppel‑like factor 5(KLF5),a transcription factor,plays an important role in regulating cell proliferation and tissue remodeling through the expression of its downstream genes.KLF5‑related factors are expected to be involved in the healing process after myocardial injury or myocardial ischemic changes,especially for the forensic diagnosis of myocardial ischemic physiopathology.Aim and Objectives:This study aimed to explore the discrimination ability and applicability of KLF5-related factors in SCD caused by MI compared with other causes of death to provide further insights into the forensic diagnosis of myocardial ischemic pathology.Materials and Methods:The relative quantification of F‑Box and WD Repeat Domain Containing 7(FBW7),KLF5,factor‑binding protein(FGFBP)1,and FGFBP2 messenger RNAs(mRNAs)in myocardial tissue samples was performed using real‑time fluorescence quantitative reverse transcription polymerase chain reaction.KLF5 and FGFBP1/2 protein levels were examined using immunohistochemistry(IHC).The forensic autopsy cases(27 in total,autopsy within 72 h postmortem)included seven cases of acute myocardial infarction and 10 cases of acute myocardial ischemia.There were 10 cases in the control group,including four cases of traffic injury one case of injury by fall from height,one case of electric death,and four cases of blunt force injury.Results:Characteristic results were found in myocardial samples from three groups of deaths:KLF5 and FGFBP1 mRNA levels were significantly elevated in the infarction and ischemia groups,while FBW7 mRNA levels were significantly decreased.FBW7 is an important ubiquitin ligase that can mediate the degradation of KLF5 protein.In addition,FBW7 and FGFBP2 mRNA levels were decreased in the infarction group compared with the ischemia group.The IHC results were consistent with the observed mRNA expression patterns.Conclusions:Quantitative detection of FBW7,KLF5,FGFBP1,and FGFBP2 mRNA transcripts in myocardial tissues supports the pathophysiological study of myocardial ischemic diseases and provides molecular pathological evidence for forensic discrimination of death causes.

Forensic Significance of Messenger RNA and Protein Expression of Genes Downstream of Hypoxia Inducible Factor 2 in Myocardial Tissue for Death Discrimination

Background: As a heterodimeric transcription factor, hypoxia-inducible factor 2 alpha subunit (HIF2A), is an important member of the HIF family. It plays a significant role in the hypoxia adaptation process by regulating the different types of downstream transcription factors and auxiliary regulatory factors. HIF2A-related factors are believed to participate in the progression of myocardial injury or myocardial ischemia, support the protection of ischemic myocardium, and provide guiding significance for the diagnosis and discrimination of sudden cardiac death in forensic pathology. Aim and Objectives: This study aimed to explore the discriminability and applicability of HIF2A-related factors in myocardial infarction cases compared with other causes of death, provide further insights for the forensic diagnosis of heart failure (HF) cases with myocardial infarction, and support the clinical treatment of patients with HF after myocardial infarction. Materials and Methods: The relative expression levels of HIF2A, amphiregulin (AREG), potassium large conductance calcium-activated channel subfamily M β1 (KCNMB1), peroxisome proliferator-activated receptor α (PPARA), vascular endothelial growth factor (VEGF), and VEGFR2 messenger RNAs (mRNAs) in myocardial tissue samples were performed using quantitative reverse transcriptase-polymerase chain reaction. A partial least squares-discriminant analysis model was constructed to select the indicators with better identification effects for myocardial infarction cases. The protein levels of HIF2A, AREG, KCNMB1, and PPARA were further detected by immunohistochemistry. The forensic autopsy cases (27 cases in total, postmortem interval <72 h) included seven cases of acute myocardial infarction and ten cases of myocardial ischemia. There were ten cases in the control group, including four cases of traffic injury, one case of injury by fall from height, and five cases of blunt force injury. Results: Characteristic results were observed in the myocardial ischemia/infarction samples. Compared with the control group, the relative mRNA expression levels of AREG, KCNMB1, and PPARA were significantly increased during the progression of myocardial ischemia, but this was not observed for HIF2A, VEGF, or VEGFR2 mRNA. Immunohistochemistry assays further verified the expression levels of the related factors at the protein level, and H and E staining showed signs of angiogenesis and inflammation in the ischemia/infarction group. Conclusions: By controlling the expression of downstream target genes (AREG, KCNMB1, and PPARA) during myocardial cell hypoxia adaptation, HIF2A has a potential significance in the diagnosis of myocardial infarction in forensic medicine. We believe that HIF2A, AREG, KCNMB1, and PPARA can be used as molecular pathological biomarkers for the discrimination of causes of death in myocardial infarction cases.