ObjectiveTo verify the association between the Ddit3-Trib3-Akt signaling pathway and rat spermatogenesis by constructing an in vitro co-culture system of testis. MethodsTesticular tissue blocks from 20-25-day-old male rats were placed in an in vitro culture system， and the culture medium was replaced every 2 to 3 days. PCR was used to verify the expression of marker genes of various spermatogenic cells. RNA interference technology was employed to verify the correlation between the Ddit3-Trib3-Akt signaling pathway and rat spermatogenesis. ResultsThe co-culture system could be continuously cultured for more than 2.5 months in vitro. RT-PCR showed that specific marker genes of spermatogonia， spermatocyte and spermoblast were expressed. The RNA and protein expression of Trib3 and Akt changed after the knocking down of Ddit3 and Trib3， respectively. It demonstrated the existence of Ddit3-Trib3-Akt signaling pathway in rat spermatogenesis. ConclusionThe culture time of more than 2.5 months indicates that the culture system can temporarily maintain the proliferation and differentiation of stem cells， and simultaneously maintain and stabilize spermatogenesis in a simple system. The successful validation of the Ddit3-Trib3-Akt signaling pathway also confirms that this culture system can be used to study possible molecular mechanisms of spermatogenesis in vitro.

To conduct a bibliometric and keyword analysis on the domestic and international literature of medical artificial intelligence （AI） ethics， explore the research frontiers， hotspots， and development trends in this field， and provide references for promoting the construction of China’s ethical governance system on medical AI. Utilizing CiteSpace software， a comparative analysis was conducted between the reviewed domestic and international literature regarding their publication volume， author and institutional collaboration networks， as well as keyword co-occurrence， clustering， timeline graph， and burst， to explore the research hotspots and development trends in the field. A total of 2 393 Chinese and English publications were included. In recent years， research topics in medical AI ethics both domestically and internationally focused on three aspects， encompassing their theoretical research， emerging domains and their ethical risks， as well as the ethical governance and regulation of medical AI. International research hotspots included federated learning， computer-aided detection， informed consent， and other aspects， whereas domestic research hotspots were smart healthcare， responsibility ethics， ethical values， and other aspects. Internationally， greater attention was placed on ethical issues concerning population health and healthcare in the public health domain， whereas domestic research topics tended to focus more on theoretical discussions and the establishment of ethical principles. The ethical governance of medical AI represents a shared global challenge， necessitating enhanced research into both the variances and commonalities in this field.

Objective To establish a mouse model of infection with the minimum lethal dose of Vibrio vulnificus(V.vulnificus)and to evaluate the protective efficacy of inactivated whole-cell(IWC)vaccine using this model.Methods A mouse model of lethal-dose infection was established by intraperitoneal injection of different doses of V.vulnificus.Bacterial colonization in the organs was detected with tissue homogenate plating,and pathological changes in the organs were observed after tissue section staining.Flow cytometry was used to detect immune cell responses after liver tissues were digested into single-cell suspension.IWC vaccine of V.vulnificus was prepared,and the mice were immunized through different routes to observe the protective efficacy of the vaccine.Results A mouse model of infection with the minimum lethal dose at 1×106 CFU of V.vulnificus was successfully established.After infection,the bacteria were mainly colonized in the liver of mice and caused severe pathological damages.Compared with the uninfected mice,the proportion of neutrophils in the liver was significantly increased in the infected mice,whereas the proportions of B cells and T cells were correspondingly decreased(P<0.05).A single intramuscular or intraperitoneal injection of the IWC vaccine could protect the mice effectively against lethal infection of V.vulnificus in 7 d later(P<0.01),although the level of serum IgG having no significant increase.Conclusion A mouse model of lethal-dose infection with V.vulnificus is successfully established,with histopathological characteristics.The IWC vaccine of V.vulnificus rapidly mediates immune protection in this model probably independent of IgG.

Objective To investigate the role of trichostatin A(TSA)in regulating CD4+T cell subpopulations during Escherichia coli(E.coli)inflammatory infections.Methods Male mice(8 weeks old,weighing 22～25 g)were randomly divided into 3 groups(n=16):a dimethyl sulfoxide(DMSO)control group,an infection group(DMSO+E.coli),and an intervention group(E.coli+TSA).E.coli was administered via intraperitoneal injection at a concentration of 3×10? CFU/mL to establish an infection model.The E.coli+TSA group was further subdivided into 3 subgroups based on different TSA concentrations(2.5,5.0,10.0 mg/kg).Then the samples were collected at different time points(12,24,48,96 h)after TSA intervention.The efficacy of TSA in treating E.coli-induced inflammatory responses and its relationship with CD4+T cell subsets were evaluated by survival rate observation,body weight monitoring,histopathological staining for small intestine,ELISA detection,transcriptomics sequencing,flow cytometry and RT-qPCR analysis.Results Compared with the E.coli group,5 mg/kg TSA significantly increased survival rate,suppressed body weight loss,improved pathological damage in the small intestinal,reduced serum TNF-α level in 24 h after infection(P<0.000 1),and elevated IL-10 level(P<0.05).Transcriptomic analysis revealed that 5 mg/kg TSA intervention for 24 h modulated the T cell differentiation signaling pathways,including those regulating FoxO,Th17,and Th1/2.Flow cytometry and RT-qPCR results showed that compared to the E.coli group,5 mg/kg TSA down-regulated the expression of the Th17 cell marker RORγt in mice 96 h after infection while significantly up-regulated the expression of the Treg cell marker Foxp3(P<0.05).Conclusion TSA may alleviate bacterial infectious inflammatory diseases by regulating the differentiation of CD4+T cells toward the Treg subset while simultaneously inhibiting their differentiation toward the Th17 subset,thereby suppressing the release of proinflammatory cytokines.

With the increasing demand for dynamic,real-time and rapid qualitative analysis of chemical composition in areas such as emergency response and space exploration,chip-scale mass spectrometers have attracted significant attention.These devices are expected to drive the integration of mass spectrometry with micro/nano-fabrication and intelligent sensing technologies,fostering profound innovation and breakthroughs in analytical chemistry.As an excellent mass analyzer,the ion trap exhibits numerous advantages,and its miniaturization creates favorable conditions for the high-density integration of miniature mass spectrometers.However,the reduction in ion storage capacity may compromise its sensitivity and dynamic range,rendering the study of ion unidirectional ejection in highly miniaturized ion traps of significant practical importance.In this work,a research was conducted on achieving efficient ion unidirectional ejection while maintaining high mass resolution in the extremely miniature hyperbolic linear ion trap(M-HLIT)with a field radius of 1 mm,and an electric field compensation method was proposed,which combined asymmetric electrode stretching and unbalanced RF voltage to achieve high-precision optimization of the electric field composition.Simulations showed that in an ideal structure,this method achieved 100％unidirectional ejection efficiency with the mass resolution of 518,significantly outperforming traditional asymmetric structure method(365)and unbalanced voltage method(321).Following the introduction of ion ejection slots,further optimization through bidirectional stretching and electrical parameters improved the resolution to 790 while maintaining a unidirectional ejection efficiency of 93％.This method eliminated the requirement for additional excitation voltage,offering an ideal solution for the miniature mass analyzer with high detection performance of chip-level mass spectrometers.

Objective To explore the mechanism of myocardial toxicity caused by N-methyl-3,4-methyle-nedioxyamphetamine(MDMA),the changes of intracellular calcium oscillation mode and calcium han-dling proteins during acute exposure to different concentrations of MDMA were detected,and the in-volvement of nuclear factor κB(NF-κB)and its effect on calcium handling proteins were investigated.Methods Primary rat cardiomyocytes were cultured to establish MDMA acute exposure model,and a control group was set up.The MDMA poisoning model was divided into three concentration groups of 10,100 and 1 000 μmol/L.After 1 h of exposure,the morphological changes of cardiomyocytes were ob-served,the cytotoxicity and changes in calcium signals were measured,and the changes in calcium handling proteins RyR2,SERCA2a,PLN,NCX1 and Cav1.2 were detected.The changes of NF-κB activity and the expression of nucleoprotein p-p65(Ser311)and PKCζ after MDMA exposure,and the intervention of NF-κB inhibitors pyrrolidine dithiocarbamate ammonium(PDTC)and protein kinase C(PKC)inhibitor chelerythrine(CHE)were detected by electrophoretic mobility shift assay(EMSA)and Western blotting.The effects of PDTC intervention on calcium signals,and the expressions of RyR2,SERCA2a,PLN,NCX1 and Cav1.2 after acute MDMA exposure were also observed.Results No obvious changes were observed in the morphology of cardiomyocytes after acute exposure to MDMA,whereas the oscillation waveform of intracytoplasmic calcium ion showed irregular changes with increased oscillation amplitude,intense fluctuations,irregular frequency,and increased fluctuation range of relative optical density values.The expression of RyR2,SERCA2a and NCX1 increased,while the expression of Cav1.2 and PLN de-creased.Acute MDMA exposure could increase NF-κB activity,while PDTC and CHE intervention could inhibit NF-κB activity.In MDMA exposed group,the expression of PKCζ and nucleoprotein p-p65(Ser311)both increased and could be inhibited by CHE.After the intervention of PDTC to block NF-κB,the amplitude of calcium oscillation was lower than that of the MDMA exposed group,and the expres-sion of RyR2,SERCA2a and NCX1 decreased.There was no significant change in PLN,while the ex-pression of Cav1.2 increased.Conclusion MDMA can lead to an increase of calcium ion concentration in cardiomyocytes.Calcium ions are involved in myocardial toxicity of MDMA.The mechanism is re-lated to changes in calcium handling proteins,mainly associated with the increased expression of RyR2.MDMA can up-regulate the intracellular activity of NF-κB through the PKCζ-NF-κB pathway and affect calcium handling proteins,which aggravate intracellular calcium overload during acute MDMA exposure.

Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.

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.

ObjectiveTo investigate the serotype distribution and antimicrobial resistance characteristics of foodborne Salmonella in infectious diarrhea cases in Minhang District, Shanghai, and to provide evidence for clinical diagnosis, treatment, prevention, and control of salmonellosis. MethodsFecal or anal swab samples were collected from foodborne diarrhea cases at sentinel hospitals between 2019 and 2023 in Minhang District of Shanghai. Salmonella was isolated, biochemically identified, and serotyped. Antimicrobial susceptibility testing was performed via the microbroth dilution method. ResultsA total of 4 294 samples were collected, from which 224 Salmonella strains were isolated, with an isolation rate of 5.22%. There was no gender difference in the positive rate of Salmonella. The positive rate showed seasonal fluctuations (χ²=160.475, P<0.001), with a higher positive rate in summer and autumn than in spring and autumn. Among different occupational groups, the positive rate was the highest among retired people (7.30%) (χ²=20.023, P=0.001). Among different age groups, the positive rate was the highest among those aged 80 years and above (7.33%) (χ²=13.491, P=0.009). A total of 28 serotypes were identified, with Salmonella Enteritidis being the most predominant, followed by Salmonella Typhimurium. Among them, 154 strains were multi-drug resistant to three or more types of antibiotics (68.75%). The most common drug resistance patterns among multi-drug resistant strains were ampicillin (AMP)-ampicillin/sulbactam (AMS)-sulfamethoxazole/trimethoprim (SXT)-chloramphenicol (CHL)-tetracycline (TET)-streptomycin (STR), AMP-TET-STR and AMP-AMS-TET-STR, with 9 strains being detected in each isolates. ConclusionThe positive rate of foodborne Salmonella in Minhang District, Shanghai, is high in summer and autumn, with a higher infection rate among retired people and those aged 60 years and above being the high-risk group. It is recommended to strengthen the protection for high-risk groups, implement targeted prevention and control measures in summer and autumn to reduce the risk of infection, and pay attention to guiding clinical medication and infection control.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.