A natural experiment is a causal inference study design grounded in real-world research. Its core concept is to use quasi-random variation in exposure generated by external factors to evaluate the effects of interventions or exposures on outcomes. It is particularly suitable for research settings in which randomized controlled trials （RCTs） are infeasible or ethically constrained， and it combines causal inference capacity with relatively strong external validity. This article provides an overview of the definition， key features， and current application status of natural experiments， and proposes the application scenarios for applying natural experiment strategies to the evaluation of therapeutic effects in traditional Chinese medicine （TCM）， including policy implementation or policy change evaluation， assessment of variations in clinical practice within hospitals， and evaluation of differences in resource allocation across regions or institutions. The design pathway includes starting from clinical or policy-related TCM questions， systematically collecting relevant data， performing statistical modeling and effect estimation， and interpreting effect estimates in the context of clinical practice. It further analyzes the advantages and challenges of using natural experiments in TCM.

A natural experiment is a causal inference study design grounded in real-world research. Its core concept is to use quasi-random variation in exposure generated by external factors to evaluate the effects of interventions or exposures on outcomes. It is particularly suitable for research settings in which randomized controlled trials （RCTs） are infeasible or ethically constrained， and it combines causal inference capacity with relatively strong external validity. This article provides an overview of the definition， key features， and current application status of natural experiments， and proposes the application scenarios for applying natural experiment strategies to the evaluation of therapeutic effects in traditional Chinese medicine （TCM）， including policy implementation or policy change evaluation， assessment of variations in clinical practice within hospitals， and evaluation of differences in resource allocation across regions or institutions. The design pathway includes starting from clinical or policy-related TCM questions， systematically collecting relevant data， performing statistical modeling and effect estimation， and interpreting effect estimates in the context of clinical practice. It further analyzes the advantages and challenges of using natural experiments in TCM.

ObjectiveThis paper aims to observe the syndrome improvement and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children （heat accumulation in the lung and stomach syndrome）. MethodsThrough a multi-center randomized controlled methodology design，confirmed influenza cases were collected from October 2022 to April 2023 in the pediatrics department of eight hospitals，such as Dongfang Hospital of Beijing University of Chinese Medicine. A total of 180 children with influenza and heat accumulation in the lung and stomach syndrome conforming to the standard were recruited through the clinic. The sick children meeting the inclusion criteria were randomly divided into groups by a block-randomized method. The children in the experimental group were treated with Qingxuan Daozhi formula for five days，and those in the control group were treated with Oseltamivir Phosphate Granules for five days. The primary efficacy indicator was the negative conversion rate of influenza antigen detection. Secondary efficacy indicators were the Canadian acute respiratory illness and flu scale （CARIFS） and the incidence of complications，severe cases， and critical cases. Follow-up observation was conducted on the day of enrollment，48 hours after medication，72 hours after medication， and （6+1） d after medication. ResultsOne hundred and eighty participants were randomly assigned to the experimental group （90 cases） or the control group （90 cases）. All participants were followed up during the study. Comparison of influenza antigen detection results in the primary efficacy indicators showed that the average time of negative influenza antigen conversion in the experimental group was （5.29±1.25） d，and that in the control group was （5.40±1.68） d，without a statistically significant difference. After five days of intervention，52 cases in the experimental group and 51 cases in the control group converted to negative，without a statistically significant difference. CARIFS score results in the secondary efficacy indicators showed that during 72 hours after intervention，there were statistically significant differences between the experimental group and the control group in three dimensions， including headache，muscle soreness， and the need for extra care （P<0.05）. On the （6+1） days after the intervention，the differences in both the experimental group and the control group were statistically significant in 10 dimensions， including sore throat，bad sleep，uncomfortable feeling，poor spirit and fatigue，crying more than usual，the need for extra care，symptom，function，influence on parents，and total score （P<0.05）. The comparison results within the group in the dimensional scores of symptom， function， and influence on parents，as well as the CARIFS total score showed that with the delay of follow-up time，scores of both groups decreased significantly，with a statistically significant difference （P<0.01）. Inter-group comparison results showed that the mean score of the experimental group was higher than that of the control group at the time of enrollment. With the progress of intervention，the score of the experimental group was significantly decreased compared with that of the control group. At the end of follow-up，the mean score of the experimental group was lower than that of the control group，with no statistically significant difference. In terms of the incidence of complications，severe cases， and critical cases， there were no complications，severe cases， and critical cases in the two groups，without a statistically significant difference. ConclusionThe symptom improvement effect and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children （heat accumulation in the lung and stomach syndrome） are not inferior to Oseltamivir Phosphate granules， and children's acceptance is better. It can be more widely used in clinical treatment of influenza in children （heat accumulation in the lung and stomach syndrome）.

Lung cancer constitutes the most prevalent and lethal malignant tumor in China. Approximately 85% of lung cancer diagnoses correspond to the non-small cell histological subtype [non-small cell lung cancer (NSCLC)]. Despite surgery being the mainstay for early-stage disease, postoperative recurrence remains high and adjuvant chemotherapy offers limited benefit. In recent years, targeted therapy has demonstrated substantial advantages in driver mutation-positive NSCLC. To this end, the Lung Cancer Medical Education Committee of the Chinese Medical Education Association developed guidelines based on a systematic review of evidence through November 2025, using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach and a modified Delphi method. Focusing on epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and addressing ROS proto-oncogene 1 (ROS1), B-Raf proto-oncogene serine/threonine kinase (BRAF) V600E mutation, and mesenchymal-epithelial transition factor (MET) exon 14 (METex14) skipping, the guideline covers molecular testing, neoadjuvant/adjuvant therapy, perioperative strategies, minimal residual disease monitoring, and postoperative surveillance. It defines testing requirements, specifies stage-directed and subtype-specific treatments, and standardizes minimal residual disease monitoring. These recommendations emphasize precision and feasibility to improve survival and quality of life.

ObjectiveTo analyze the microbial culture positivity rate， pathogen spectrum， prevalence of multidrug-resistant organisms （MDROs）， and differences among donor procurement sources in corneas from the Eye Bank of Guangdong Province， and to provide evidence for eye bank quality control and the prevention of post-keratoplasty infections. MethodsThis retrospective study included 7 442 donor corneas procured by the Eye Bank of Guangdong Province and used for keratoplasty at Zhongshan Ophthalmic Center， Sun Yat-sen University， between 2018 and 2025. During surgery， donor corneoscleral rim tissue was excised for bacterial and fungal culture. Culture-positive specimens underwent microbial identification and antimicrobial susceptibility testing （AST）. Culture-positive corneas were compared across study years， pathogen categories， and donor procurement sources. ResultsOf the 7 442 donor corneas， 251 were culture-positive， corresponding to an overall culture positivity rate of 3.37%， with annual rates ranging from 1.50% to 5.31%. Among culture-positive corneas， 178 （70.92%） yielded bacteria alone， 72 （28.68%） yielded fungi alone， and 1 （0.40%） yielded both bacteria and fungi. Candida spp. and Aspergillus spp. were the predominant fungal isolates. Gram-negative bacteria were more frequently isolated than Gram-positive bacteria. The most common bacterial isolates were Acinetobacter baumannii， Staphylococcus epidermidis， Stenotrophomonas maltophilia， Enterococcus faecium， and Pseudomonas fluorescens. MDROs accounted for 75.47% of bacterial isolates， predominantly Acinetobacter baumannii， Staphylococcus epidermidis， and Enterococcus faecium， and demonstrated an increasing trend over the study period. Donor corneas procured through the Hospital Cornea Retrieval Program （HCRP） had a higher culture positivity rate than those obtained through Organ Procurement Organization （OPO） （P＜0.000 1）. Among culture-positive donor corneas， the proportion of fungal culture-positive corneas was significantly higher in the HCRP group than in the OPO group （P=0.001 5）， whereas the proportion of MDROs among bacterial culture-positive corneas was significantly higher in the OPO group than that in the HCRP group （P=0.005 2）. ConclusionsThe overall culture positivity rate of donor corneas from the Eye Bank of Guangdong Province is relatively low， indicating that the risk of microbial contamination is controlled. However， pathogen profiles and antimicrobial resistance patterns varies by procurement source. Ongoing microbiological and antimicrobial resistance surveillance， together with optimized donor risk assessment and timely reporting of culture results， may further improve eye bank quality management and help inform strategies for preventing post-keratoplasty infections.

ObjectiveTo analyze the microbial culture positivity rate， pathogen spectrum， prevalence of multidrug-resistant organisms （MDROs）， and differences among donor procurement sources in corneas from the Eye Bank of Guangdong Province， and to provide evidence for eye bank quality control and the prevention of post-keratoplasty infections. MethodsThis retrospective study included 7 442 donor corneas procured by the Eye Bank of Guangdong Province and used for keratoplasty at Zhongshan Ophthalmic Center， Sun Yat-sen University， between 2018 and 2025. During surgery， donor corneoscleral rim tissue was excised for bacterial and fungal culture. Culture-positive specimens underwent microbial identification and antimicrobial susceptibility testing （AST）. Culture-positive corneas were compared across study years， pathogen categories， and donor procurement sources. ResultsOf the 7 442 donor corneas， 251 were culture-positive， corresponding to an overall culture positivity rate of 3.37%， with annual rates ranging from 1.50% to 5.31%. Among culture-positive corneas， 178 （70.92%） yielded bacteria alone， 72 （28.68%） yielded fungi alone， and 1 （0.40%） yielded both bacteria and fungi. Candida spp. and Aspergillus spp. were the predominant fungal isolates. Gram-negative bacteria were more frequently isolated than Gram-positive bacteria. The most common bacterial isolates were Acinetobacter baumannii， Staphylococcus epidermidis， Stenotrophomonas maltophilia， Enterococcus faecium， and Pseudomonas fluorescens. MDROs accounted for 75.47% of bacterial isolates， predominantly Acinetobacter baumannii， Staphylococcus epidermidis， and Enterococcus faecium， and demonstrated an increasing trend over the study period. Donor corneas procured through the Hospital Cornea Retrieval Program （HCRP） had a higher culture positivity rate than those obtained through Organ Procurement Organization （OPO） （P＜0.000 1）. Among culture-positive donor corneas， the proportion of fungal culture-positive corneas was significantly higher in the HCRP group than in the OPO group （P=0.001 5）， whereas the proportion of MDROs among bacterial culture-positive corneas was significantly higher in the OPO group than that in the HCRP group （P=0.005 2）. ConclusionsThe overall culture positivity rate of donor corneas from the Eye Bank of Guangdong Province is relatively low， indicating that the risk of microbial contamination is controlled. However， pathogen profiles and antimicrobial resistance patterns varies by procurement source. Ongoing microbiological and antimicrobial resistance surveillance， together with optimized donor risk assessment and timely reporting of culture results， may further improve eye bank quality management and help inform strategies for preventing post-keratoplasty infections.

ObjectiveTo explore the potential mechanism of Xiezhuo Jiedu prescription in regulating autophagy in the treatment of ulcerative colitis （UC） by bioinformatics and animal experiments. MethodsThe differentially expressed genes （DEGs） in the colonic mucosal tissue of UC patients was obtained from the Gene Expression Omnibus （GEO）， and those overlapped with autophagy genes were obtained as the differentially expressed autophagy-related genes （DEARGs）. DEARGs were imported into Metascape and STRING， respectively， for gene ontology/Kyoto Encyclopedia of Genes and Genomics （GO/KEGG） enrichment analysis and protein-protein interaction （PPI） analysis. Finally， 15 key DEARGs were obtained. The core DEARGs were obtained by least absolute shrinkage and selection operator （LASSO） regression and receiver operating characteristic curve （ROC） analysis. The CIBERSORT deconvolution algorithm was used to analyze the immunoinfiltration of UC patients and the correlations between core DEARGs and immune cells. C57BL/6J mice were assigned into a normal group and a modeling group. The mouse model of UC was established by free drinking of 2.5% dextran sulfate sodium. The modeled mice were assigned into low-， medium-， and high-dose Xiezhuo Jiedu prescription and mesalazine groups according to the random number table method and administrated with corresponding agents by gavage for 7 days. The colonic mucosal morphology was observed by hematoxylin-eosin staining. The protein and mRNA levels of cysteinyl aspartate-specific proteinase 1 （Caspase-1）， cathepsin B （CTSB）， C-C motif chemokine-2 （CCL2）， CXC motif receptor 4 （CXCR4）， and hypoxia-inducing factor-1α （HIF-1α） in the colon tissue were determined by Western blot and real-time fluorescence quantitative polymerase chain reaction， respectively. ResultsThe dataset GSE87466 was screened from GEO and interlaced with autophagy genes. After PPI analysis， LASSO regression， and ROC analysis， the core DEARGs （Caspase-1， CCL2， CTSB， and CXCR4） were obtained. The results of immunoinfiltration analysis showed that the counts of NK cells， M0 macrophages， M1 macrophages， and dendritic cells in the colonic mucosal tissue of UC patients had significant differences， and core DEARGs had significant correlations with these immune cells. This result， combined with the prediction results of network pharmacology， suggested that the HIF-1α signaling pathway may play a key role in the regulation of UC by Xiezhuo Jiedu prescription. The animal experiments showed that Xiezhuo Jiedu prescription significantly alleviated colonic mucosal inflammation in UC mice. Compared with the normal group， the model group showed up-regulated protein and mRNA levels of caspase-1， CCL2， CTSB， CXCR4， and HIF-1α， which were down-regulated after treatment with Xiezhuo Jiedu prescription or mesalazine. ConclusionCaspase-1， CCL2， CTSB， and CXCR4 are autophagy genes that are closely related to the onset of UC. Xiezhuo Jiedu prescription can down-regulate the expression of core autophagy genes to alleviate the inflammation in the colonic mucosa of mice.

ObjectiveTo investigate the anti-Alzheimer's disease （AD） effect of Dipsacus asper（DA） in the Caenorhabditis elegans model， and decipher the underlying mechanism via the peroxisome proliferator-activated receptor α （PPARα）/transcription factor EB （TFEB） pathway. MethodsFirst， transgenic AD C. elegans individuals were assigned into the blank control， model， positive control （WY14643， 20 µmol·L^-1）， and low-， medium-， and high-dose （100， 200， and 400 mg·L^-1， respectively） DA groups. The amyloid β-42 （Aβ₄₂） formation in the muscle cells， the paralysis time， and the deposition of amyloid β-protein （Aβ） in the head were detected. The lysosomal autophagy in the BV2 cell model was examined by Rluc-LC3wt/G120A. The expression levels of lysosomal autophagy-related proteins LC3Ⅱ， LC3I， LAMP2， and TFEB were detected by Western blot. Real-time quantitative polymerase chain reaction （Real-time PCR） was employed to determine the mRNA levels of autophagy-related genes beclin1 and Atg5 and lysosome-related genes LAMP2 and CLN2 downstream of PPARα/TFEB. A reporter gene assay was used to detect the transcriptional activities of PPARα and TFEB. Immunofluorescence was used to detect the fluorescence intensity of PPARα， and the active components of the ethanol extract of DA were identified by UPLC-MS. RCSB PDB， Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP）， and Autodock were used to analyze the binding between the active components and PPARα-ligand-binding domain （LBD）. ResultsCompared with the model group， the positive control group and 200 and 400 mg·L^-1 DA groups showed prolonged paralysis time （P<0.05）， and all the treatment groups showed decreased Aβ deposition in the head （P<0.01）. DA within the concentration range of 50-500 mg·L^-1 did not affect the viability of BV2 cells. In addition， DA enhanced the autophagy flux （P<0.05）， up-regulated the mRNA levels of beclin1， Atg5， LAMP2， and CLN2 （P<0.05， P<0.01）， promoted the nuclear translocation of TFEB （P<0.05）， increased LAMP2 expression and autophagy flux （P<0.05， P<0.01）， and enhanced the transcriptional activities of PPARα and TFEB （P<0.01）. The positive control group and 200 and 400 mg·L^-1 DA groups showed enhanced fluorescence intensity of PPARα in the BV2 nucleus （P<0.01）. UPLC-MS detected nine known compounds of DA， from which 8 active components of DA were screened out. The docking results suggested that a variety of components in DA could bind to PPARα-LBD and form stable hydrogen bonds. ConclusionDA may reduce the pathological changes in AD by regulating the PPARα-TFEB pathway.

Objective:To explore the effect of exercise on the memory of rats modeling vascular cognitive impairment (VCI) and also its effects on the hippocampal Sema3G/neuropilin-2 (Nrp2)/PlexinA4 signaling pathway.Methods:Eighteen male Sprague-Dawley rats were randomly divided into a sham-operated group, a model group, and an exercise group, each of 6. The model and exercise groups underwent VCI modeling via bilateral common carotid artery occlusion, while the sham-operated group received the same surgical procedure without vessel ligation or transection. Beginning forty-eight hours after the surgery, the exercise group carried out daily 30-minute treadmill training sessions, 5 days a week, for a total of 4 weeks, while the other two groups were placed on the same treadmill with it not in operation. After the intervention, cognitive functioning was assessed using the novel object recognition (NOR) test and a Y-maze test. Western blotting was employed to evaluate the expression of Sema3G, Nrp2, PlexinA4, and Rac1 in the hippocampus. Immunofluorescence staining was used to observe the distribution of Nrp2 and PlexinA4 in the hippocampus.Results:Compared with the model group, the exercise group exhibited significantly higher NOR indices during both the short-term and long-term memory testing phases after the intervention. Those rats also tended to have significantly longer total exploration times in the novel arm of the Y-maze test. The western blotting revealed that the expression levels of Sema3G, PlexinA4, and Rac1 in the hippocampus were significantly higher in the exercise group compared to the model group, on average. Immunofluorescence showed significantly increased PlexinA4 fluorescence intensity in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus, and significantly elevated Nrp2 fluorescence intensity in the CA3 region in the exercise group compared to the model group. The Pearson correlation coefficients for Nrp2/PlexinA4 co-localization in the CA1, CA3 and DG regions were significantly higher in the exercise group than in the model group.Conclusions:Exercise training significantly improves memory function in rats with VCI, and this effect may be associated with activation of the hippocampal Sema3G/Nrp2/PlexinA4 signaling pathway.

Objective:Exploring the association between Life's Crucial 9 (LC9) and the risk of thyroid dysfunction (TD), as well as its potential predictive capacity.Methods:A total of 247 600 TD-free participants from the UK Biobank were enrolled in the study. The LC9 score was divided into three CVH groups: low (0-), medium (50-), and high (80-100). Cox proportional hazards regression models were used to calculate the HRs and 95% CIs of the risk of TD with LC9 CVH status. Calculate Harrell's concordance index ( C-index), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) to evaluate the predictive ability of the LC9 score and Life's Essential 8 (LE8) score. Results:During a median follow-up of 12.3 years, 5 515, 911, and 4 869 new cases of TD, hyperthyroidism, and hypothyroidism were documented, respectively. Participants with a high LE8 CVH group had 57.00% ( HR=0.43, 95% CI: 0.38-0.49), 55.00% ( HR=0.45, 95% CI: 0.34-0.60), and 58.00% ( HR=0.42, 95% CI: 0.37-0.47) lower risk of TD, hyperthyroidism, and hypothyroidism, respectively, than those with low CVH group. Compared with the LE8 score, the improvement in C-index for the LC9 score predicted TD risk was 0.004 (95% CI: 0.001-0.007), the NRI was 0.101 (95% CI: 0.021-0.103), and the IDI was 0.001 (95% CI: 0.000-0.001). Conclusions:The better CVH status, defined by LC9, was associated with a lower risk of TD. Compared to the LE8 score, the LC9 score demonstrated a significant enhancement in both risk discrimination and reclassification capability for TD risk.