Age-related sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. It is primarily characterized by a significant decline in muscle mass, strength, and physical function, rather than being an inevitable consequence of normal aging. Despite ongoing research, there is still no globally unified consensus among physicians regarding the diagnostic criteria and clinical indicators of this condition. Nonetheless, regardless of the diagnostic standards applied, the prevalence of age-related sarcopenia remains alarmingly high. With the global population aging at an accelerating rate, its incidence is expected to rise further, posing a significant public health challenge. Age-related sarcopenia not only markedly increases the risk of physical disability but also profoundly affects patients’ quality of life, independence, and overall survival. As such, the development of effective prevention and treatment strategies to mitigate its dual burden on both societal and individual health has become an urgent and critical priority. Skeletal muscle regeneration, a vital physiological process for maintaining muscle health, is significantly impaired in age-related sarcopenia and is considered one of its primary underlying causes. Skeletal muscle satellite cells (MSCs), also known as muscle stem cells, play a pivotal role in generating new muscle fibers and maintaining muscle mass and function. A decline in both the number and functionality of MSCs is closely linked to the onset and progression of sarcopenia. This dysfunction is driven by alterations in intrinsic MSC mechanisms—such as Notch, Wnt/β‑Catenin, and mTOR signaling pathways—as well as changes in transcription factors and epigenetic modifications. Additionally, the MSC microenvironment, including both the direct niche formed by skeletal muscle fibers and their secreted cytokines, and the indirect niche composed of extracellular matrix proteins and various cell types, undergoes age-related changes. Mitochondrial dysfunction and chronic inflammation further contribute to MSC impairment, ultimately leading to the development of sarcopenia. Currently, there are no approved pharmacological treatments for age-related sarcopenia. Nutritional intervention and exercise remain the cornerstone of therapeutic strategies. Adequate protein intake, coupled with sufficient energy provision, is fundamental to both the prevention and treatment of this condition. Adjuvant therapies, such as dietary supplements and caloric restriction, offer additional therapeutic potential. Exercise promotes muscle regeneration and ameliorates sarcopenia by acting on MSCs through various mechanisms, including mechanical stress, myokine secretion, distant cytokine signaling, immune modulation, and epigenetic regulation. When combined with a structured exercise regimen, adequate protein intake has been shown to be particularly effective in preventing age-related sarcopenia. However, traditional interventions may be inadequate for patients with limited mobility, poor overall health, or advanced sarcopenia. Emerging therapeutic strategies—such as miRNA mimics or inhibitors, gut microbiota transplantation, and stem cell therapy—present promising new directions for MSC-based interventions. This review comprehensively examines recent advances in MSC-mediated muscle regeneration in age-related sarcopenia and systematically discusses therapeutic strategies targeting MSC regulation to enhance muscle mass and strength. The goal is to provide a theoretical foundation and identify future research directions for the prevention and treatment of this increasingly prevalent condition.

Objective To establish a chromatography-tandem mass spectrometry method for detecting chlorfenapyr and its metabolite tralopyril in blood,and to investigate the toxicokinetics in rats.Methods Chlorfenapyr(8 mg/kg)was administered orally to rats,and blood samples were collected from rats'canthus vein at 5 min,15 min,30 min,1 h,3 h,6 h,12 h,24 h and 48 h after administration.The blood samples were extracted using 100 μL of 5%formic acid solution and 400 μL of acetonitrile.Chlorfena-pyr was qualitatively and quantitatively detected by triple quadrupole gas chromatography-tandem mass spectrometry(GC-MS/MS)and tralopyril was detected by triple quadrupole liquid chromatography-tandem mass spectrometry(LC-MS/MS).The DAS 3.0 software was used to fit the toxicokinetic equa-tions and calculate the toxicokinetic parameters.Results Chlorfenapyr was detectable from 5 min to 24 h with a peak time of 1 h.Tralopyril was detectable from 15 min to 48 h with a peak time of 3 h.The toxicokinetic process of chlorfenapyr in rat blood conformed to a first-order absorption one-compartment open model,with the toxicokinetic equation described as C=e-0.265t-e-0.175t.Tralopyril con-formed to the first-order absorption three-compartment model,and the toxicokinetic equation was C=47 361.069e-2.209t-35 404.962e-1.486t+11 956.363e-0.512t.In the equations,C stands for the concentration of the target substance in the blood,e is the natural constant(≈2.718 28),and t stands for time.Conclu-sion This study optimized the detection method for chlorfenapyr and its metabolite tralopyril in blood.The toxicokinetic equations and parameters of chlorfenapyr and tralopyril can provide a reference for the estimation of oral intake time of chlorfenapyr.

Objective To observe the difference of bone micro-structure in different regions of proximal femur,micro-CT scanning was performed on 30 proximal femur specimens to explain the mechanism of proximal femur fracture and to provide anatomical basis for prosthesis design.Methods Totally 30 intact proximal femur specimens were obtained from 60-80 year-old cadavers.Micro-CT scanning was used to measure the trabecular thickness(Tb.Th),trabecular number(Tb.N),trabecular space(Tb.Sp),connectivity(Conn)and bone mineral density(BMD)and other parameters in 7 regions of proximal femur,including proximal pressure trabecular(PPT),distal pressure trabecular(DPT),femoral head-neck junction(FHNJ),head and neck of femoral neck(HNFN),the base of femoral neck(BPFN),intertrochanteric line(IL)and greater trochanter(GT).Results The bone mineral density of IL and GT were higher than those of BPFN,FHNJ,DPT and PPT.The trabecular thickness of GT was the largest,followed by IL,BPFN and HNFN,and the smallest was FHNJ,DPT and PPT.The trabecular space of IL was larger than that of GT,and the data of both were larger than those of other parts,among which DPT and PPT were the smallest.The trabecular number of IL and GT were the smallest,BPFN,HNFN and FHNJ were larger,and DPT was the largest.The volume fraction of IL was the smallest,BPFN and HNFN were larger,DPT and PPT were the largest.Conclusion The bone density,trabecular thickness,bone volume,and total volume of GT and IL in the proximal femur of elderly patients are all relatively large,so the reason for the high incidence of fractures is not due to weak internal bone microstructure;The bone density,trabecular thickness,and trabecular gap at the proximal and distal ends of the vertical trabecular bone are relatively small.If it is necessary to perform core decompression for prosthesis filling at this location,the design should be conducive to the mechanical conduction of the prosthesis and the regeneration of surrounding bone tissue.

Objective To investigate the expression of myelin transcription factor 1-like(MYT1L)during amyotrophic lateral sclerosis(ALS)progression and its association with neuronal degeneration through bioinformatics analysis combined with in vivo and in vitro experiments.Methods Bioinformatics analysis of the GSE106803 dataset from the Gene Expression Omnibus(GEO)database revealed significant down-regulation of MYT1L in spinal cords of ALS transgenic mice carrying the human superoxide dismutase 1 mutant gene(hSOD1G93A)compared to the wild-type(WT)mice.hSOD1G93A transgenic mice and their WT littermates were selected to analyze MYT1L mRNA and protein changes in spinal cord tissues at different disease stages using Real-time PCR and Western blotting.Double immunofluorescent staining was used to determine the distribution and cellular localization of MYT1L in the spinal cord of mice at the middle stage of the disease.An ALS cellular model was established using hSOD1G93A mutant NSC34 cells,with hSOD1WT NSC34 cells as controls.MYT1L expression and distribution were assessed in these cells via Real-time PCR,Western blotting,and immunofluorescent staining.Based on the GSE76220 dataset from the GEO database,differentially expressed genes(DEGs)between MYT1L high-and low-expression groups in lumbar spinal motor neurons of ALS patients were identified,followed by Gene Ontology(GO)functional enrichment analysis.MYT1L overexpression was induced in the ALS cellular model to evaluate alterations in cell viability and neurite outgrowth.Results In the GSE106803 dataset,MYT1L expression was significantly down-regulated in the spinal cord of ALS mice.Animal experiments confirmed progressive reductions in MYT1L mRNA and protein levels in spinal cord tissues of ALS mice during mid-and late-disease stages.Compared to the WT group,MYT1L expression decreased in motor neurons of the lumbar spinal cord gray matter anterior horn in ALS mice,while it increased in astrocytes.In vitro,hSOD1G93Amutant NSC34 cells exhibited significantly reduced MYT1L expression than controls,with MYT1L localized to both the cytoplasm and nucleus.DEGs between MYT1L high-and low-expression groups in lumbar spinal cord motor neurons of ALS patients(GSE76220 dataset)were enriched in synaptic-related functions through GO analysis.Overexpression of MYT1L in hSOD1G93A mutant NSC34 cells enhanced cell viability and promoted neurite outgrowth.Conclusion Aberrantly low expression of MYT1L is closely associated with ALS pathogenesis.Overexpression of MYT1L promotes neurite growth and exerts protective effects on ALS motor neurons,suggesting its therapeutic potential.

Objective To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response(ABR)in adults using CE-Chirp to ana-lyze the relationship between the V-wave response threshold of CE-Chirp ABR test and the pure tone hearing threshold.Methods Subjects(aged 20-77 with a total of 100 ears)who underwent CE-Chirp ABR test in Changzhou De'an Hospital from January 2018 to June 2019 were selected to obtain the V-wave response threshold,and pure tone air conduction hearing threshold tests were conducted at 0.5,1.0,2.0 and 4.0 kHz,respectively,to obtain pure tone listening threshold.The differences and statistical differences between the average pure tone hearing threshold and V-wave response threshold were compared in different hearing levels and different age groups.The correlation,differences and statistical differences between the two tests at each frequency were analyzed for all subjects.The lin-ear regression equation for estimating pure tone hearing threshold for all subjects CE-Chirp ABR V-wave response threshold was established,and the feasibility of the equation was tested.Results There was no statistical significance in the CE-Chirp ABR response threshold and pure tone hearing threshold dif-ference between different hearing level groups and different age groups(P>0.05).There was a good correlation between adult CE-Chirp ABR V-wave response threshold and pure tone hearing threshold with statistical significance(P<0.05),and linear regression analysis showed a significant linear correla-tion between the two(P<0.05).Conclusion The use of CE-Chirp ABR V-wave response threshold can be used to evaluate subjects'pure tone hearing threshold under certain conditions,and can be used as an audiological test method for forensic hearing impairment assessment.

Objective To establish a rapid screening method for 34 emerging contaminants in surface water by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-Q-TOF-MS).Methods The pretreatment conditions of solid phase extraction(SPE)were op-timized by orthogonal experimental design and the surface water samples were concentrated and ex-tracted by Oasis? HLB and Oasis? MCX SPE columns in series.The extracts were separated by Kine-tex? EVO C18 column,with gradient elution of 0.1%formic acid aqueous solution and 0.1%formic acid methanol solution.Q-TOF-MS'fullscan'and'targeted MS/MS'modes were used to detect 34 emerging contaminants and to establish a database with 34 emerging contaminants precursor ion,prod-uct ion and retention times.Results The 34 emerging contaminants exhibited good linearity in the con-centration range respectively and the correlation coefficients(r)were higher than 0.97.The limit of de-tection was 0.2-10 ng/L and the recoveries were 81.2%-119.2%.The intra-day precision was 0.78%-18.70%.The method was applied to analyze multiple surface water samples and 6 emerging contaminants were detected,with a concentration range of 1.93-157.71 ng/L.Conclusion The method is simple and rapid for screening various emerging contaminants at the trace level in surface water.

Objective To investigate the effect of microglia activation regulated by C-X3-C motif chemokine ligand 1(CX3CL1)-C-X3-C motif chemokine receptor 1(CX3CR1)pathway on memory function in hemorrhagic shock/resuscitation rats.Methods The experiment was divided into two parts.In the first part,the rats were randomly divided into sham group,model-0.5 hour group,model-1.5 hour group,model-3 hour group,10 rats in each group.There were differences in the time of hemorrhagic shock among each group.In the second part,rats were randomly divided into control group and CX3CL1 group,10 rats in each group.The rats in CX3CL1 group were treated with CX3CL1 protein factor(intraventricular injection),and the rats in control group were treated with saline.All rats were trained in Morris water maze experiments before model construction,and tests of Morris water maze experiments were carried out after 4 days of model construction.After completion,the whole brains were taken for HE staining and immunohistochemical staining.Cerebrospinal fluid was taken for detection of inflammatory cytokines,and hippocampus tissues were taken for Real-time PCR detection and Western blotting detection.Results Compared with the sham group,the escape latency of rats in model group increased,the number of platform crossings and the resident time in the third quadrant decreased.The neuronal state was impaired in HE staining in model group.In addition,compared with the sham group,the expression of ionized calcium binding adaptor molecule-1(Iba1)in the brain of the rats in model group increased,the contents of tumor necrosis factor-α(TNF-α)and interleukin(IL)-6 in the cerebrospinal fluid increased,and the M1-type microglia markers CD16,TNF-α,IL-1β and inducible nitric oxide synthase(iNOS)mRNA content increased.At the same time,compared with the sham group,the expressions of CX3CL1 and CX3CR1 in the brain of model group decreased,and the expressions of phosphorylated nuclear factor-κB(p-NF-κB)and nucleotide binding oligomerization domain(NOD)-like receptor protein 3(NLRP3)increased.However,compared with the control group,rats in CX3CL1 group had reduced escape latency,increased platform crossing times and quadrantⅢresident time,and recovered neuronal states.In addition,the expression of Iba1 in the brain of CX3CL1 group decreased,the contents of TNF-α and IL-6 in the cerebrospinal fluid decreased,the mRNA contents of M1-type microglia markers like CD16,TNF-α,IL-1β and iNOS decreased,and the mRNA contents of markers of M2-type microglia glial like CD206,transforming growth factor-β(TGF-β),arginase-1(Arg1),Chitinase 3-like protein 1(Ym 1)increased.Conclusion CX3CL1 can help inhibit the excessive activation of microglia,induce the polarization of microglia to M2 type,inhibit the polarization of M1 type,reduce the release of inflammatory cytokines,and alleviate the memory function damage induced by hemorrhagic shock/resuscitation.

Objective:To understand the major cognition, major choice motivation and the relationship between the two of medical students, and provide references and suggestions for the selection of talents in various majors of medical schools and the effective development of enrollment work.Methods:This study selected undergraduates of Batch 2019 from Peking University Health Science Center as the survey objects, conducted a questionnaire survey on their major cognition, major choice motivation and influencing factors, and used principal component analysis and Spearman rank correlation analysis.Results:The study found that the major cognition scores of 640 undergraduates of Batch 2019 from Peking University Health Science Center were clinical medicine (3.24±0.89) > stomatology (2.89±1.00) > basic medicine (2.66±1.02) > pharmacy (2.54±0.97) > preventive medicine (2.29±0.93) > nursing medicine (2.21±0.99) > medical laboratory (1.98±0.95) > medical English (1.95±0.93). Six major motivation factors for professional choice were school and professional strength, professional learning and job prospects, own factors, Peking University sentiments and the influence of others, medical factors, school policies, and the contribution rates were 34.60%, 12.97%, 7.42%, 6.00%, 5.59% and 5.37%, respectively. Major cognition scores and major choice motivation factors were positively correlated with each other to some extent.Conclusions:At present, students' major cognition level of medical majors still has a large room for improvement, and the motivational factors of major choice are more complicated, among which "the school and professional strength" and "the prospects of study and work" are important factors. Medical schools should focus on strengthening major publicity, improving students' major cognition, attracting aspiring students to apply for medical majors from many aspects, and improving the training quality of medical professionals.

Objective To explore the anti-atherosclerosis mechanism of Hirudo and its effect on autophagy in mice.Methods Forty healthy male ApoE-/-mice were randomly divided into model group,control group(3 × 10-3 g·kg-1·d-1 simvastatin)and experimental-L,experimental-M,experimental-H groups(0.45,0.9,1.8 g·kg-1· d-1,Maixuekang capsule).Eight healthy male C57BL/6J mice were divided into blank group.The mice were fed with common diet for 1 week.Then,except blank group,other groups were fed with high-fat diet.After 8 weeks of modeling,the atherosclerosis(AS)mice were given drugs orally once a day for 12 weeks,and fed with high-fat diet in the meantime.The levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)in serum were determined by enzyme-linked immunosorbent assay(ELISA).The levels of Beclin-1,LC3 autophagy protein were detected by Western blot method.Results The IL-6 contents in the experimental-H,experimental-M,experimental-L,control,model and blank groups were(107.59±3.03),(99.31±5.12),(103.52±2.28),(98.68±4.68),(112.66±6.08),(93.98±3.43)pg·mL-1;the TNF-α contents were(538.41±30.26),(504.49±21.51),(538.51±19.05),(494.05±25.08),(578.53±26.32),(467.35±21.53)pg·mL-1.For the above indexes,the differences between model group and experimental-H group,experimental-M group,experimental-L group,control group,blank group were all statistically significant(all P＜0.05).The Beclin-1 protein expression levels in the experimental-H,experimental-M,experimental-L,control and model groups were 1.48±0.05,1.72±0.05,1.19±0.02,1.51±0.04,0.66±0.03;the LC3 Ⅱ protein expression levels were 1.53±0.01,1.83±0.02,1.16±0.01,1.90±0.01,0.49±0.01,and the differences between model group and experimental-H group,experimental-M group,experimental-L group,control group were all statistically significant(all P＜0.05).Conclusion Hirudo can significantly reduce the area of atherosclerotic plaque by regulating the level of autophagy.

Objective To investigate the effect and mechanism of Heixiaoyao powder in regulating mitogen-activated protein kinase phosphatase-1(MKP-1)/c-Jun N-terminal kinase(JNK)signaling pathway on the level of Tau protein and neuroinflammation in the hippocampus of Alzheimer's disease(AD)rats.Methods Male Wistar rats with SPF grade were randomly divided into blank,sham-operation,model,control and experimental-L,-M,-H groups with 10 rats per group.In addition to the blank and sham-operation groups,the other 5 groups of rats were injected with β-amyloid 1-42(Aβ1-42)solution in bilateral hippocampus to replicate AD rat model,and the sham-operation group was injected with the same amount of 0.9％NaCl in the same way.Animals successfully replicated in the model were randomly divided into model group,control group(0.5 mg·kg-1 donepezil hydrochloride)and experimental-L,-M,-H groups(3.82,7.65,15.30 g·kg-1 Heixiaoyao powder decoction).The blank,sham-operation and model groups were given equal volume of 0.9％NaCl by gavage.The drug was given by gavage once a day for 42 days.Morris water maze was used to detect the learning and memory ability of rats.The levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in hippocampus were detected by enzyme-linked immunosorbent assay.Western blot was used to detect the expression of MKP-1,phospho JNK(p-JNK)and phospho Tau(p-Tau)proteins.Results The escape latency on day 5 of the experimental-M,-H groups,control group,model group,sham-operation group and blank group were(8.28±7.67),(7.89±4.18),(7.86±2.68),(16.55±4.16),(6.46±3.30)and(3.60±1.53)s;the levels of TNF-α in the above groups were(406.56±28.44),(404.17±22.84),(402.28±28.36),(665.89±61.15),(226.44±34.84)and(218.50±30.16)pg·mL-1;IL-6 levels were(136.54±7.04),(121.67±5.19),(119.15±5.87),(166.27±8.91),(88.75±5.28)and(79.58±7.53)ng·L-1;the relative expression levels of MKP-1 protein were 2.31±0.34,2.59±0.38,2.58±0.37,1.23±0.25,2.64±0.19 and 2.84±0.18;the relative expression levels of p-JNK protein were 3.46±0.35,3.45±0.31,3.20±0.23,4.48±0.30,2.87±0.51 and 2.30±0.26;the relative expression levels of p-Tau protein were 3.46±0.33,3.24±0.48,3.09±0.31,4.85±1.06,2.69±0.34 and 2.40±0.55,respectively.Compared with the model group and the normal group,compared with the experimental group and the model group,the differences of above indexes were statistically significant(P＜0.05,P＜0.01).Conclusion Heixiaoyao powder can improve the learning and memory ability of AD rats,and its mechanism may be related to the regulation of MKP-1 and JNK proteins,thus inhibiting the phosphorylation level of Tau protein and alleviating neuroinflammation.