Clinical death refers to the permanent cessation of life functions. This article reviews the definition of clinical death and the various scenarios in which it occurs, classifies the process of clinical death, and discusses the criteria for determining uncontrollable cardiac death, controllable cardiac death and the criteria and workflow for determining brain death. It elaborates on the relationship between brain death and death, and proposes the areas to note when standardizing the medical documentation of death cases. Based on this, it introduces the content of the management system and workflow construction for death determination in medical institutions, including management structure, personnel qualifications, document norms, quality control system and training mechanism. Paying attention to the construction of the management system and workflow for death determination in medical institutions is of great significance for ensuring medical quality and safety, promoting the healthy development of organ donation, and maintaining the seriousness of legal and ethical practices.

Metabolic associated fatty liver disease （MAFLD） is the most prevalent chronic liver disease worldwide， and its progression is closely associated with the development of liver fibrosis， liver cirrhosis， and even hepatocellular carcinoma. However， there is still a lack of effective therapies for MAFLD in clinical practice. Telomere is the protective structure at the end of chromosomes， and telomere shortening and functional impairment have been identified as one of the key factors regulating the pathological progression of MAFLD. This article systematically reviews the core mechanism of action of telomere regulation in MAFLD， including its molecular functions in nucleotide metabolism， oxidative stress， and epigenetic regulation， as well as its pathological effect in hepatocytes and hepatic stellate cells. In addition， this article explores the clinical prospects of telomeres as biomarkers and therapeutic targets for MAFLD， in order to provide a theoretical reference for improving the precise diagnosis and treatment system of MAFLD.

The implementation of the "Regulations on Organ Donation and Transplantation" (hereinafter referred to as the new "Regulations") and supporting documents has laid a solid foundation for improving the organ donation and transplantation work system in accordance with laws and regulations. In order to better publicize, implement, and carry out the new "Regulations" and supporting documents, and in response to the problems and challenges encountered in actual work, combined with the development of the national human organ donation and transplantation work system and the national work on determination of brain death, this article analyzes and discusses the construction of hospitals' organ donation and transplantation work systems and the systematic multidisciplinary collaboration mechanism for organ donation, as well as several issues that need attention by the ethics committees for organ transplantation. The aim is to provide references for the construction of ethics committees for organ transplantation in China and to promote the continuous and healthy development of China's organ donation and transplantation cause.

Objective:To understand the incidence rate of herpes zoster (HZ) and postherpetic neuralgia (PHN) in Beijing, and analyze the incidence trend of HZ and PHN from 2015 to 2022.Methods:Cases of HZ and PHN from 2015 to 2022 were retrieved from the Hospital Information Systems (HIS) of all primary and above hospitals/clinics in three districts representing the urban, inner suburban, and outer suburban areas of Beijing. After duplication screening, the first visit cases were screened, and the incidence characteristics were described. The incidence rate of HZ and PHN in each year by sex and age group and the age-standardized incidence rate were calculated. The annual percentage increase (APC) of incidence rate was calculated using the Joint regression model, and the change trend was analyzed.Results:The age-standardized incidence rate of HZ in Beijing from 2015 to 2022 ranged from 7.44‰ to 10.05‰, with an average annual incidence rate of 8.95 ‰, significantly increasing with age ( P<0.001). The Joinpoint regression model showed that the overall age-standardized incidence of HZ remained relatively stable, with no significant difference (APC=2.28%, t=1.56, P=0.170). However, the incidence rate among the 0-19-year-old group exhibited a trend of decrease (APC=-10.70%, t=-6.29, P<0.001). For PHN, the age-standardized incidence in Beijing ranged from 0.77‰ to 2.67‰, with an average annual incidence rate of 1.59‰ and a proportion of 9.48% to 26.86% among HZ cases. Both the incidence of PHN and its proportion among HZ cases increased with age ( P<0.001). The age-standardized incidence of PHN increased annually (APC=18.56%, t=9.02, P<0.001). Conclusion:The incidence rate of HZ and PHN in Beijing continues to be at a high level, and PHN shows an increasing trend over time.

Mandibular reconstruction refers to the restoration of the continuity of the mandible through techniques such as autologous bone grafting,thereby restoring the patient's basic appearance,reconstructing the occlusal relationship,and restoring functions such as opening the mouth,chewing,and swallowing,in order to achieve a unity of oral and maxillofacial forms and functions.Due to the fact that mastication necessitates the coordinated efforts of the masticatory muscles,mandible,dental arch,and tongue,the recovery of masticatory function not only serves as a robust indicator for the success of surgery but also enhances the patients'quality of life,facilitating an early return to normal life.Currently,for the rehabilitation of oral function in patients after mandibular reconstruction surgery,standardized tools have been established in the fields of swallowing,occlusion,and speech assessment,and targeted training has been implemented,yielding significant therapeutic outcomes.However,research related to masticatory function faces two major challenges.First,existing assessment tools primarily focus on a single dimension,such as masticatory efficiency or subjective perception,and an integrated assessment system that encompasses multiple dimensions,including bite force distribution and oral sensory perception,has not yet been established.Second,although individual studies have explored factors affecting postoperative masticatory function,a systematic consensus has not been veached,leading to a lack of precision and individualization in clinical interventions,which significantly prolongs the patients'rehabilitation period.This paper reviews the scope and limitations of existing assessment tools for masticatory function in patients after mandibular reconstruction and systematically analyzes the key factors affecting postoperative masticatory function,aiming to promote a shift in clinical practice from"structural reconstruction"to a"function-perception collaborative rehabilitation"approach,and to provide a theoretical framework for constructing evidence-based,personalized masticatory rehabilitation programs.

Objectives:This study aims to evaluate the causal relationship between plasma proteins and myocardial infarction(MI)using two-sample bidirectional Mendelian randomization(MR)analysis,identify key biomarkers,and validate their expression.Methods:The study utilized publicly available genome-wide association study(GWAS)data of 4 907 plasma proteins as the exposure factor,with single nucleotide polymorphisms(SNPs)as instrumental variables,and four MI datasets as outcomes.Two-sample MR analysis was performed using the inverse variance weighted(IVW)method,complemented by simple model,weighted model,weighted median estimator(WME),and MR-Egger regression methods to assess the causal relationship between exposure factors and outcomes.Venn diagrams and word clouds were used to screen proteins associated with MI as candidate biomarkers.Reverse MR analysis was conducted to evaluate reverse causality.Sensitivity analysis was performed to assess the robustness of the results.Immunohistochemistry(IHC)was used to validate the expression of proteasome activator subunit 1(PSME1)and vacuolar protein sorting 29(VPS29)in the aorta of mice,and enzyme-linked immunosorbent assay(ELISA)was used to verify the expression of PSME1 and VPS29 in plasma from patients with acute myocardial infarction(AMI).Results:The two-sample MR analysis indicated that PSME1 was significantly negatively associated with myocardial infarction in all four datasets,with OR(95%CI)of 0.684(0.557-0.839),0.990(0.987-0.993),0.579(0.448-0.748),and 0.993(0.990-0.996),respectively,with all P<0.001.Similarly,VPS29 also showed a significant negative association with MI in all four datasets,with OR(95%CI)of 0.902(0.862-0.945),0.998(0.997-0.999),0.866(0.808-0.929),and 0.998(0.997-0.999),respectively,with all P<0.001.Reverse MR analysis did not detect reverse causality,and sensitivity analysis confirmed the robustness of the results.IHC results showed significantly reduced expression of PSME1 and VPS29 in the aortas of AMI mice with an atherosclerotic background compared to control mice(both P<0.05).ELISA results indicated significantly lower plasma levels of PSME1 and VPS29 in AMI patients compared to healthy controls(both P<0.05).Conclusions:Higher levels of PSME1 and VPS29 are negatively associated with the risk of MI,suggesting that PSME1 and VPS29 may serve as protective biomarkers for cardiovascular diseases.

Objective To explore the dietary nutrition status and nutritional intervention strategy of patients with Alzheimer’s disease (AD). Methods Among the 1 332 patients with AD diagnosed at Xijing Hospital from January 2021 to December 2023 were enrolled as the study subjects. The dietary intake data of patients were collected through questionnaire surveys and dietary reviews. During the study period, 30 patients did not complete the intervention due to withdrawal or loss of follow-up. Based on the actual number of people who completed the intervention, AD patients were randomly divided into intervention group (n=651, individualized nutritional intervention strategy) and control group (n=651, routine nutritional intervention), and both groups were intervened for 3 months. The cognitive function (MMSE score and MoCA score), nutritional status (MNA scale, NRS-2002 scale), and quality of life (GQOL-74) of the two groups of AD patients were compared to evaluate the effectiveness of the intervention strategies. Results A total of 1 332 questionnaires were distributed, and 1 302 valid questionnaires were finally recovered, with an effective recovery rate of 97.75% (1 302/1 332). The survey results showed that there were no statistical differences in baseline characteristics and dietary nutrition status between the two groups of AD patients before intervention (P>0.05). After nutritional intervention, the cognitive function, quality of life, and nutritional status of patients in the intervention group were significantly improved. The MMSE score, MoCA score, MNA score, and GQOL-74 score of the intervention group were significantly higher than those of the control group, while the NRS-2002 score was lower than that of the control group (P<0.05). Conclusion Nutritional intervention strategy has a significant effect on improving nutritional status, cognitive function, and quality of life of AD patients.

Aim To evaluate the tyrosine nitration modification of specific proteins in vascular endothelial cells and its impact on mitochondria-mediated apoptosis.Methods Human umbilical vein endothelial cells were cultured in vitro and divided into three groups:control group(treatment with dimethyl sulfoxide),3-morphansulam(SIN-1)group,and SIN-1+Fe(Ⅲ)5,10,15,20-(tetraphenyl)porphyrin(FeTPP)group.After 24 h,the levels of hexokinase 1(HK1)nitration modification,mitochondrial membrane potential,reactive oxygen species(ROS)production,and endothelial cell proliferation and apoptosis were assessed.A human umbilical vein endothelial cell line knockout of HK1 was constructed using gene editing technology,and its proliferation and apoptosis levels were detected.Results After treatment of hu-man umbilical vein endothelial cells with peroxynitrite generator SIN-1,the level of HK1 protein nitration modification sig-nificantly increased(P＜0.01),reactive oxygen species production significantly increased,mitochondrial membrane poten-tial significantly decreased,endothelial cell proliferation ability significantly decreased,and endothelial cell apoptosis level significantly increased(all P＜0.01).Peroxynitrite decomposition catalyst FeTPP could reverse the above effect(P＜0.01).In addition,HK1 gene knockout also exhibited similar antioxidant effects,with a significant decrease in endothe-lial cell proliferation ability and a significant increase in apoptosis levels(P＜0.01).Conclusion Peroxynitrite can induce an increase in the level of nitration modification of HK1 in vascular endothelial cells,which may be achieved by pro-moting the production of mitochondrial reactive oxygen species,thereby accelerating the process of endothelial cell apoptosis.

Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.

Objective:To analyze the clinical characteristics and treatment outcomes of children with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody-mediated necrotizing myopathy, and to explore early identification and management strategies to provide reference for clinical diagnosis and treatment.Methods:A retrospective analysis was conducted on the clinical data and treatment outcomes of 10 pediatric patients with anti-HMGCR antibody-mediated necrotizing myopathy admitted to the Department of Rheumatology, Children′s Hospital of Fudan University from December 2020 to December 2024. Statistical description was performed using SPSS 22.0.Results:Among the 10 patients, the male-to-female ratio was 1:4, the age of onset was (7.2±4.0) years, and the disease duration at diagnosis was (22.2±19.6) months. None had a history of statin exposure. Six patients presented with muscle weakness, and4 were diagnosed due to asymptomatic elevation of creatine kinase (CK); 4 had dermatomyositis-like rashes. All patients showed significantly elevated CK levels [median 3 291(1 969, 8 776)U/L] and underwent muscle biopsy. Histopathological findings revealed myofiber degeneration, necrosis, and regeneration in all cases, with inflammatory infiltration in 9 cases, MHC-Ⅰ positivity in all, and C5b-9 positivity in 9 cases. The median follow-up duration was (15.7±6.3) months. At the last follow-up, muscle strength was normal or nearly normal, and the CK median value had decreased to 977.5 (211.0, 3 536.0) U/L.Conclusion:For patients with suspected idiopathic inflammatory myopathy and significantly elevated CK, muscle-specific antibody testing-including anti-HMGCR-and muscle biopsy should be performed promptly regardless of the presence of skin rash, to ensure accurate diagnosis and guide treatment, thereby avoiding misdiagnosis or missed diagnosis.