Biological evidence is relatively common evidence in criminal cases,and it has strong pro-bative power because it carries DNA information for individual identification.At the scene of fire-related cases,the complex thermal environment,the escape of trapped people,the firefighting and res-cue operations,and the deliberate destruction of criminal suspects will all affect the biological evi-dence in the fire scene.Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes,and found that the blood stains,semen stains,bones,etc.are the main biological evidence which can be easily recovered with DNA in fire scenes.In order to analyze the research status and development trend of biological evidence in fire scenes,this paper systematically sorts out the relevant research,mainly including the soot removal technology,appearance method of typical biological evidence,and possibility of identifying other biological evidence.This pa-per also prospects the next step of research direction,in order to provide reference for the identifica-tion of biological evidence and improve the value of biological evidence in fire scenes.

Objective To evaluate the characteristics of different antigen-specific T cell immune responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)after inoculation with 2 doses of SARS-CoV-2 inactivated vaccine for 12 months.Methods Fifteen healthy adults were enrolled in this study and blood samples collected at 12 months after receiving two doses of SARS-CoV-2 inactivated vaccine.The level and phenotypic characteristics of SARS-CoV-2 antigen-specific T lymphocytes were detected by activation-induced markers(AIM)based on polychromatic flow cytometry.Results After 12 months of inoculation with 2 doses of SARS-CoV-2 inactivated vaccine,more than 90%of adults had detectable Spike and Non-spike antigen-specific CD4+ T cells immune responses(Spike:14/15,P=0.0001;Non-spike:15/15,P<0.0001).80%of adults had detectable Spike and Non-spike antigen-specific CD8+ T cells immune responses(Spike:12/15,P=0.0463;Non-spike:12/15,P=0.0806).Antigen-specific CD4+ T cells induced by SARS-CoV-2 inactivated vaccination after 12 months were composed of predominantly central memory(CM)and effector memory 1(EM1)cells.On the other hand,in terms of helper subsets,antigen-specific CD4+ T cells mainly showed T helper 1/17(Th1/17)and T helper 2(Th2)phenotypes.Conclusions SARS-CoV-2 inactivated vaccination generates durable and extensive antigen-specific CD4+ T cell memory responses,which may be the key factor for the low proportion of severe coronavirus disease 2019(COVID-19)infection in China.

Foods can be contaminated with foodborne pathogens through a variety of pathways, including water, air and soil. Food safety events caused by foodborne pathogens show a serious impact on human health. However, due to the diversity of foodborne pathogens and the complexity of food matrices, the rapid detection of foodborne pathogens was difficult. The conventional microbial culture and physiological and biochemical identification can hardly meet the need of rapid detection of foodborne pathogens in the field. It is necessary to develop rapid detection technologies for foodborne pathogens. Clustered regularly interspaced short palindromic repeats (CRISPR) and associated protein (Cas) are an adaptive immune systems of prokaryotes with specific recognition and cleavage of nucleic acid sequences, which shows good potential for development of nucleic acid detection and biosensing in the field. According to different forms of application, paper-based analytical devices can be categorized into test paper, lateral flow assay and microfluidic paper-based chips, etc. As a good simplicity and low-cost analytical testing tools, they show good prospects in the field of rapid testing. Therefore, the rapid and sensitive detection of foodborne pathogens can be realized by combining the efficient recognition ability of CRISPR/Cas system and the simplicity of paper-based analytical devices. In this paper, we briefly introduce an overview of the CRISPR/Cas system for nucleic acid detection, and this section focuses on an overview of the features and principles of the class 2 system, including types II, V and VI, which uses a single effector. The application of CRISPR/Cas system based test paper analysis, lateral flow assay and microfluidic paper-based chips for the detection of foodborne pathogens are highlighted in the paper, and finally the advantages, current challenges and future prospects of CRISPR/Cas system in combination with paper-based analytical devices to establish detection methods are discussed.

Objective To investigate the screening and prevalence of tuberculosis among freshmen in different schools in Baoding City,and provide reference for tuberculosis control in schools.Methods Screening data of tu-berculosis and tuberculin test(PPD)of freshmen from 156 schools in different regions of Baoding City from Septem-ber 2021 to March 2022 were collected.PPD screening results of students from different regions and different school stages were analyzed and compared.Results A total of 68 177 freshmen from 156 schools were investigated for suspected symptoms and close contact history of pulmonary tuberculosis.PPD screening was conducted on 63 939 students.13 821 students were PPD positive,with a positive rate of 21.62％.3 083 students were strongly posi-tive,with a strong positive rate of 4.82％.15 cases of tuberculosis were found,and the reported incidence was 23.46/100 000.PPD positive rate and strong positive rate as well as incidence of tuberculosis in students in different school stages presented statistically significant differences(all P＜0.01).Positive rate and strong positive rate in students in different school stages showed upward trends(all P＜0.01).PPD positive rate and strong positive rate of students from schools in plain and mountainous areas presented statistically significant differences([22.28％vs 17.89％];[4.85％vs 3.62％],both P＜0.01).PPD positive rate and strong positive rate between students from boarding junior school and non-boarding junior school were significantly different,respectively([23.94％vs 21.60％];[5.07％vs 3.56％],both P＜0.01).Conclusion It is necessary to strengthen tuberculosis screening and health education for freshmen,especially those from boarding schools in plain areas,screening latent Mycobac-terium tuberculosis infection as early as possible,take corresponding measures to prevent and control the spread of tuberculosis,and reduce the risk of tuberculosis.

Objective:To investigate effects of mesalazine(MS)on proliferation,apoptosis and inflammatory injury of cell model of ulcerative colitis(UC)induced by lipopolysaccharide(LPS),as well as transforming growth factor-β1(TGF-β1)/Smad signaling pathway effect in this study.Methods:Human colonic epithelial cells NCM-460 cultured in vitro were induced UC model by LPS,and divided into Con group(no treatment),LPS group(1 mg/L LPS),MS group(0.1,0.2,0.4 mg/L MS+1 mg/L LPS)and inhibitor group(10 μmol/L TGF-β1/Smad signaling pathway inhibitor LY2109761+0.2 mg/L MS+1 mg/L LPS).Cell morphology,proliferation,apoptosis and levels of inflammatory factors and TGF-β1/Smad pathway-related markers were examined by inverted microscope,EdU assay,Hoechst 33258 staining,ELISA and Western blot.Results:LPS treatment highly induced cell proliferation rate and Smad7 pro-tein level compared with Con group,while apoptotic cells,inflammatory factors TNF-α and IL-6,soluble interleukin-2 receptor(sIL-2R)release,as well as TGF-β1,p-Smad2,p-Smad3 protein expressions were increased;the above effects induced by LPS was reversed by MS in a dose-dependent manner(P<0.05).Compared with 0.2 mg/L MS group,NCM-460 cells proliferation rate and Smad7 expression were increased,while apoptotic cells,TNF-α and IL-6,sIL-2R releases,and TGF-β1,p-Smad2,p-Smad3 protein expressions were decreased(P<0.05).Conclusion:MS can attenuate LPS-induced apoptosis and inflammatory injury in NCM-460 cells,and this protection was possibly through suppressing TGF-β1/Smad signaling pathway.

Objective To investigate whether curcumin is a potential drug for the treatment of gastrointestinal stromal tumors(GIST).Methods The differential genes of imatinib-resistant cells and non-resistant cells were analyzed by cell transcriptology.The antitumor activity of curcumin was verified by cell counting kit-8(CCK-8)method,and the concentration of Curcumin ranged from 5 to 80 μg·mL-1for GIST-T1 and GIST-T1/IMR cells.20 μg·mL-1 Curcumin as the experimental group,phosphate buffered solution as the control group.The contents of interleukin-6(IL-6),reactive oxygen species(ROS)and nitric oxide(NO)were measured by enzyme linked immunosorbent assay.The cell cycle changes were analyzed by flow cytometry.Results Using non-resistant cells as a contrast,the results showed that there were 1 300 up-regulated genes and 1 609 down-regulated genes in imatinib-resistant cells.The 50％inhibiting concentration values of Curcumin on GIST-T1 and GIST-T1/IMR cells were(15.33±1.36)and(10.49±2.12)μg·mL-1,respectively.In GIST-T1 cells,the IL-6 levels in experimental group and control group were(3.45±0.01)and(5.64±0.42)pg·mL-1;the ROS levels were(2 841.42±81.83)and(4 174.32±439.12)pg·mL-1;the iNOS levels were(7.02±0.08)and(8.08±0.03)μmol·L-1,respectively.In GIST-T1/IMR cells,the IL-6 levels in experimental group and control group were(2.47±0.30)and(6.30±0.01)pg·mL-1;the ROS levels were(4 706.40±146.71)and(8 254.34±342.35)pg·mL-1;the iNOS levels were(6.42±0.09)and(7.29±0.04)μmol·L-1,respectively.Among the 2 cells,the differences of above indicators were statistically significant between the experimental group and the control group(P＜0.05,P＜0.01).Curcumin blocked the cell cycle of GIST-T1 and GIST-T1/IMR in G1 phase,further shortens S phase and G2 phase.Conclusion Curcumin can inhibit the secretion of inflammation and regulate the proliferation of GIST.

The author analyzed the characteristics of phase Ⅰ clinical trials of macromolecular drugs,the characteristics of evaluation indicators of phase Ⅰ clinical trials of macromolecular drugs,such as safety evaluation,pharmacokinetic and pharmacodynamic evaluation,and efficacy evaluation.And the control points of subjects management,management of experimental macromolecule drugs,and identified and potential risk factors of macromolecule drugs in the implementation of risk management for phase Ⅰ clinical trials of macromolecule drugs were discussed in depth based on previous clinical trial research experience.Through discussion and analysis,the author suggests that each research center can formulate risk control strategies according to the actual situation,improve the efficiency of risk control,and facilitate the smooth implementation of clinical trials and improve the quality of clinical trials.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective:To identify the risk factors and to construct a predictive model for early postnatal mortality (with the first 7 days of life) in extremely preterm infants.Methods:This retrospective study involved 244 extremely preterm infants with a gestational age of 22 to 27 weeks and 6 days, born at the Affiliated Hospital of Jining Medical College from January 2017 to December 2022. They were divided into an early survival group ( n=140) and an early mortality group ( n=84), based on survival for ≥7 days after birth. LASSO and logistic regression were used to select risk factors for early mortality. A nomogram predictive model was constructed using the R software program. The goodness-of-fit tests, area under the curve (AUC), calibration curves, and decision curves were used to evaluate its performance and clinical usefulness. Results:LASSO regression and multivariate logistic regression analyses showed that breech delivery ( OR=3.055, 95% CI: 1.125-8.296), intubation in the delivery room ( OR=4.320, 95% CI: 1.328-14.053), diagnosis of grade Ⅲ-Ⅳ neonatal respiratory distress syndrome within 6 h after birth ( OR=11.552, 95% CI: 3.056-43.677), and use of adrenaline in the delivery room ( OR=10.706, 95% CI: 1.454-78.816) were risk factors for early mortality in extremely preterm infants. Conversely, large gestation age ( OR=0.234, 95% CI: 0.125-0.436), antenatal administration of corticosteroids to promote fetal lung maturity ( OR=0.046, 95% CI: 0.014-0.145), and the use of pulmonary surfactant within 6 h after birth ( OR=0.021, 95% CI: 0.004-0.122) were protective factors against mortality. The goodness of fit test of the early death risk nomogram prediction model for extremely preterm infants indicates a good fit ( P=0.702). The AUC of the model was 0.963 (95% CI: 0.943-0.983), with a sensitivity of 0.904 (95% CI: 0.806-0.949), specificity of 0.892 (95% CI: 0.829-0.938), and accuracy of 0.880. Decision curve analysis indicated that a threshold probability>2% would yield a net benefit. Conclusions:Breech delivery, intubation in the delivery room, use of adrenaline in the delivery room, and the diagnosis of grade Ⅲ-Ⅳ neonatal respiratory distress syndrome within 6 h post-birth are independent risk factors for early mortality in extremely preterm infants. Large gestational age, antenatal administration of corticosteroids to promote fetal lung maturity and use of pulmonary surfactant within 6 h after birth are protective factors. The constructed prediction model based on the aforementioned factors can quantitatively, conveniently, and intuitively assess the risk of early mortality in extremely preterm infants.

AIM To investigate the effects of total Astragalus saponins on the improvement of sarcopenia in a rat model of type 2 diabetes mellitus(T2DM).METHODS The rats were divided into the normal group for a normal feeding and the model group for the feeding of high-sugar and high-fat diet combined with intraperitoneal injection of STZ to establish a T2DM model.The successful model rats were randomly divided into the model group,the metformin group(0.2 g/kg)and the total Astragalus saponins group(80 mg/kg),and given corresponding doses of drugs by gavage.After 12 weeks administration,the rats had their FBG,postprandial blood glucose(PG2h)and wet weight of skeletal muscle measured;their serum levels of INS,C-peptide(C-P),IGF-1,TNF-α and IL-1β detected by ELISA;their morphological changes of skeletal muscle observed by HE staining;their protein expressions of PI3K,p-Akt,mTOR,S6K1,FoxO1 and Murf1 in skeletal muscle detected by Western blot;and their mRNA expressions of Pi3k,Akt and mtor in skeletal muscle detected by RT-qPCR method.RESULTS Compared with the model group,the total Astragalus saponins group displayed decreased levels of FBG,PG2h,OGTT-AUC,HOMA-IR,TNF-α and IL-1β(P＜0.01);increased levels of INS,C-P,IGF-1 and wet weight of skeletal muscle(P＜0.05,P＜0.01);improved skeletal muscle atrophy and increased protein expressions of PI3K,p-Akt,mTOR and S6K1 in skeletal muscle(P＜0.05,P＜0.01);decreased protein expressions of FoxO1 and Murf1(P＜0.05,P＜0.01);and increased mRNA expressions of Pi3k,Akt and mtor(P＜0.01).CONCLUSION The improvement effects of total Astragalus saponins on sarcopenia in T2DM rats may be associated with the regulation of PI3K/Akt/mTOR and PI3K/Akt/FoxO1 pathways.