Hygroscopicity research has long been a key focus and hot topic in Chinese materia medica（CMM）. Elucidating hygroscopic mechanisms plays a vital role in formulation design， process optimization， and storage condition selection. Hygroscopic models serve as essential tools for characterizing CMM hygroscopic mechanisms， with various types available. The double exponential model is a kinetic mathematical model constructed based on the law of conservation of energy and Fick's first law of diffusion， tailored to the physical properties of CMM extracts. In recent years， this model has been extensively applied to simulate the dynamic moisture absorption behavior of CMM extracts and solid dosage forms under varying humidity conditions. It has revealed the correlation between moisture absorption kinetic parameters and material properties， offering a new perspective for characterizing the moisture uptake behavior of CMM. This paper systematically reviews the application progress of this model in the field of CMM， analyzes its advantages， disadvantages， and challenges in this domain， and explores its potential application trends in other fields. It aims to provide references for elucidating the moisture absorption mechanisms of CMM and researching moisture-proofing technologies， while also offering insights for its broader application in food and polymer materials.

Objective To analyze the pollution characteristics of PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) during the non-heating period, heating period, and haze period in Harbin, and infer their possible sources, and to evaluate their impact on population carcinogenesis. Methods From 2020 to 2022, sampling points were set up in different districts of Harbin. PM_2.5 samples were regularly collected every month to analyze the contents of 10 types of PM_2.5-bound 4-6 rings PAHs. The pollution characteristics of PAHs were analyzed during different monitoring periods (non-heating period, heating period, and haze period). The excess carcinogenesis risks of PM_2.5-bound PAHs were assessed according to the Technical Specifications for Health Risk Assessment of Ambient Air Pollution and the U. S. Environmental Protection Agency (US EPA) risk assessment method. The characteristic ratio method and the positive matrix factorization (PMF) model were used to infer the sources of PAHs. Results The median mass concentrations of ambient PM_2.5-bound 4-6 rings PAHs (ΣPAHs) during the non-heating period, heating period, and haze period were 6.44 ng/m³, 37.85 ng/m³, and 106.79 ng/m³, respectively. During the heating season and haze period, the concentrations of benzo[a]anthracene, benzo[k]fluoranthene, pyrene and fluoranthene were relatively high. The excess carcinogenic risks for ASF_>16, ASF_2-16 and ASF_<2 caused by exposure to PM_2.5-bound 4-6rings PAHs during the heating season were 2.34×10^-6, 1.82×10^-6, and 0.88×10^-6, respectively, while the excess carcinogenic risks for the whole population during the heating season and haze period were 5.05×10^-6 and 1.75×10^-6, respectively. The results of the two source methods showed that the main characteristic elements during the heating season were fluoranthene, pyrene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene. According to the emission source standards, it was determined that the sources were mainly coal and biomass combustion, accompanied by traffic source emissions. Conclusion In Harbin, the PM_2.5-bound 4-6 rings PAHs during the haze period is significantly higher than that during the heating period. The pollution is mainly from coal combustion emissions, accompanied by continuous traffic source pollution. The exposure to PAHs during the heating period poses a potential carcinogenic risk to the population.

Animal models of cardiac arrhythmia are important tools for analyses of antiarrhythmic drug mechanisms and medical laboratory teaching.In this study,two major models,namely,barium chloride-induced arrhythmia in rabbits and ouabain-induced arrhythmia in guinea pigs,were systematically compared in terms of technical principles,modeling method,and indexes.By optimizing electrocardiographic parameters,standardizing arrhythmia grading criteria,and introducing quantitative analysis method,we revealed differences between the two models in terms of ion channel mechanisms,drug targets,and applicability to teaching.The barium chloride model was characterized by rapidly induced ventricular arrhythmia,which is suitable for the observation of acute drug efficacy.The ouabain model simulated the development of progressive arrhythmia,which is suitable for the study of the preventive effects of anti-arrhythmic drugs.This study provides a technical reference for the selection of arrhythmia models,optimization process,and mechanistic analyses in medical experimental teaching and is of great significance for improving the electrophysiology experimental skills of medical students.

Objective:To evaluate the prevalence of hepatitis C virus (HCV) infection among patients attending a comprehensive tertiary hospital in Beijing and to pinpoint the key demographics for anti-HCV screening.Methods:A comprehensive retrospective analysis was undertaken, examining data from 631 424 patients who underwent anti-HCV testing between 2017 and 2023. Testing for anti-HCV was conducted using the Abbott i2000 fully automated chemiluminescent immunoassay analyzer. HCV nucleic acid testing was performed with the Roche Cobas AmpliPrep/Cobas TaqMan 96 fluorescent quantitative PCR system, while HCV genotyping was achieved through sequencing.Results:The positive rate of HCV antibodies demonstrated a gradual decline over the years, decreasing from 1.62% in 2017 to 1.01% in 2023. The overall positive rate stood at 1.36% (8 574/631 424), with a nucleic acid testing rate of 59.24% (5 079/8 574) and a nucleic acid positive rate of 34.28% (1 741/5 079). The majority of anti-HCV positive patients came from the department of hepatology (12.17%), followed by hepatobiliary surgery (3.03%), emergency medicine (1.68%), cardiovascular medicine (1.24%) and ophthalmology clinic (1.23%). Notably, the anti-HCV positive rate was significantly elevated in the ≥40 years old group compared to the <40 years old group, with statistical significance ( χ2=1 892.577, P=0.000). The highest anti-HCV positive rates were observed within the 60-69- and 80-99-years old brackets (both at 1.85%), while the peak HCV RNA positive rate was recorded in the 50-59 years old group (27.08%). Females exhibited a significantly higher positive rate (18.53%) than males (15.75%) ( χ2=8.066, P<0.01). When anti-HCV levels surpassed 9 S/CO, the HCV RNA positive rate was notably high, exceeding 38.97%. Intriguingly, at antibody levels ranging from 15 to 16 S/CO, the HCV RNA positive rate climbed to a maximum of 56.17%. Conclusions:This study has successfully identified the key populations for anti-HCV screening: Patients aged over 40, particularly female patients within the 50-69 age bracket; Patients in hepatology, hepatobiliary surgery, emergency medicine, cardiovascular medicine and ophthalmology departments.

Objective:To analyze the clinical characteristics of the Chikungunya fever outbreak in Shunde District, Foshan City, Guangdong Province in July 2025 and the risk factors associated with delayed viral RNA clearance.Methods:A total of 562 patients with Chikungunya fever admitted to three designated hospitals in Shunde District from July 10 to 30, 2025 were enrolled. Demographic data, clinical manifestations, and laboratory findings were collected. Patients were categorized into four age groups including minors (<18 years), young adults (18 to 39 years), middle-aged adults (40 to 64 years) and elderly adults (≥65 years). The differences of clinical characteristics among these age groups were analyzed. Intergroup comparisons were performed using chi-square test, one-way analysis of variance, or Kruskal-Wallis H test. Pairwise comparisons between groups were conducted using the Bonferroni or Games-Howell or Dunn method. Binary logistic regression was employed to analyze risk factors associated with delayed viral RNA clearance (>7 days). Results:The mean age of the 562 enrolled Chikungunya fever patients was (44.8±21.3) years. Fever, arthralgia and rash were the three core symptoms, with incidence rates of 87.5% (492/562), 88.4%(497/562) and 69.6%(391/562), respectively. At discharge, only 54.1%(304/562) of patients achieved complete symptom resolution, while 26.5%(149/562) still had arthralgia and 36.1%(203/562) had residual rash. Significant differences were observed among age groups in the incidence of fever ( χ2=9.43, P=0.024), peak body temperature ( F=6.54, P<0.001), incidence of arthralgia ( χ2=26.89, P<0.001), duration of arthralgia ( F=12.68, P=0.001), incidence of rash ( χ2=68.99, P<0.001), rate of residual rash at discharge ( χ2=32.37, P<0.001), lymphocyte count ( F=12.94, P<0.001), platelet count ( F=14.95, P<0.001), and C-reactive protein levels (CRP) ( H=94.18, P<0.001). Further pairwise comparisons revealed that compared to the middle-aged and elderly groups, the minor group had a higher incidence of fever and a lower incidence of arthralgia, and the duration of arthralgia was shorter than the elderly group (all P<0.008 3). Compared with the other three groups, the elderly group had lower incidence and residual rate of rash, and lower platelet counts (all P<0.008 3), and higher levels of CRP (all P<0.05). The elderly group had lower lymphocyte counts compared to the minor and young adult groups (both P<0.05). Significant differences were found among age groups in the time to viral RNA clearance ( F=5.77, P=0.003) and length of hospital stay ( F=11.64, P<0.001), with the elderly group having significantly longer duration for both compared to the other three groups (all P<0.05). Multivariate analysis showed that advanced age (odds ratio ( OR)=1.049, 95% confidence interval ( CI) 1.015 to 1.083), longer duration of fever ( OR=1.529, 95% CI 1.086 to 2.155) and longer duration of arthralgia ( OR=1.927, 95% CI 1.318 to 2.817) were independent risk factors for delayed viral RNA clearance (all P<0.05). Conclusions:Patients with Chikungunya fever in Shunde District primarily present with fever, arthralgia and rash. The incidence and characteristics of these three core symptoms show age-related variations. Elderly patients and those with longer durations of fever or arthralgia are more likely to experience delayed viral clearance.

Purpose The study aimed to analyze the relationship between MET gene variants and clinicopathologi-cal features in patients with non-small cell lung cancer(NSCLC).Methods Next-generation sequencing technology was used to detect MET gene variants in NSCLC specimens.The association between MET gene variant status and clini-copathological features was then analyzed.Results Among 1 633 cases of NSCLC,the overall MET mutation rate was 4.53％(74/1 633).Variants were mainly observed in male patients,never-smokers,those older than 60 years,ade-nocarcinoma histology,and patients with TNM stage Ⅲ+Ⅳ disease(P＜0.05).MET gene variant status showed no significant assocication with patient age,sex,smoking history,or pathological subtype(P＞0.05),but was statistical-ly correlated with clinical stage and presence of distant metastasis(P＜0.05).The two major variant types were MET exon 14 skipping and MET amplification,which together accounted for 71.62％of all variants.In addition,MET am-plification was positively correlated with EGFR(P=0.003,rs=0.340)and TP53 mutations(P=0.002,rs=0.362),but showed no correlation with KRAS or ALK gene mutations.In contrast,MET exon 14 skipping was nega-tively correlated with EGFR gene mutations(P＜0.001,rs=-0.409),and showed no significant correlation with KRAS,ALK,or TP53 mutations.Conclusion Different types of MET gene variants(amplification,exon 14 skip-ping,fusion,and others)are significantly associated with clinical advanced clinical stage and distant metastasis in NSCLC,but are independent of patient age,sex,smoking history,and pathological subtype.MET amplification fre-quently co-occur with EGFR and TP53 co-mutations.

Animal models of cardiac arrhythmia are important tools for analyses of antiarrhythmic drug mechanisms and medical laboratory teaching.In this study,two major models,namely,barium chloride-induced arrhythmia in rabbits and ouabain-induced arrhythmia in guinea pigs,were systematically compared in terms of technical principles,modeling method,and indexes.By optimizing electrocardiographic parameters,standardizing arrhythmia grading criteria,and introducing quantitative analysis method,we revealed differences between the two models in terms of ion channel mechanisms,drug targets,and applicability to teaching.The barium chloride model was characterized by rapidly induced ventricular arrhythmia,which is suitable for the observation of acute drug efficacy.The ouabain model simulated the development of progressive arrhythmia,which is suitable for the study of the preventive effects of anti-arrhythmic drugs.This study provides a technical reference for the selection of arrhythmia models,optimization process,and mechanistic analyses in medical experimental teaching and is of great significance for improving the electrophysiology experimental skills of medical students.

Cardiovascular diseases that develop from hypercholesterolemia-induced atherosclerosis have emerged as a significant threat to human health.Recently,probiotics exhibiting cholesterol-lowering properties have emerged as a prominent area of research.Numerous studies have demonstrated that Lactobacillus reuteri can effectively reduce endogenous cholesterol synthesis,regulate cholesterol transport,and promote cholesterol degradation by modulating the expression of key genes,such as sterol-regulatory element binding protein 2,3-hydroxy-3-methyl-glutaryl coenzyme A reductase,and cholesterol 7 alpha-hydroxylase,in both the liver and intestinal epithelial cells of the host.This leads to a notable decrease in total cholesterol and low-density lipoprotein cholesterol levels in the host serum.The present paper offers a comprehensive overview of the underlying mechanisms responsible for the cholesterol-lowering effects exerted by L.reuteri,aiming to provide valuable insights into the treatment of hypercholesterolemia and the development of probiotics with cholesterol-lowering properties.

Objective:To investigate influence of different phantoms on the results of quality control for the images of cone beam computed tomography(CBCT)for breast on the basis of quality control for breast CBCT.Methods:Five different manufacturers'phantoms were selected,and they were placed at the position of testing breast in clinical examination to conduct position for phantom according to the method of the national health industry standard WS 818-2023.The analysis focused on the differences of evaluation results of using different phantoms for image quality on the basis of a series of parameters included uniformity,resolution of high contrast,resolution of low contrast,and CT value of water in scanning images of different phantoms.Data collection and image reconstruction were performed respectively by using commonly clinical procedures.Corresponding module images were selected from the reconstructed images of standard breast phantom.The common layer thickness and projection method of the system were set to record and analyze data.Results:The image uniformity of measured results of the five phantoms were respectively 42.37±2.01,-5.83±0.15,3.76±0.15,2.16±0.06,3.60±0.10.The differences of the image uniformities among the five phantoms were statistically significant(F=1310.02,P<0.001),and the differences of the CT values of the measured water among the five phantoms were statistically significant(F=9 846.46,P<0.001).The differences in the resolution of low contrast among them were also statistically significant(F=27.50,P<0.001).However,the results of the resolution of high contrast were stability,and there was no significant difference in that among the five phantoms.Conclusion:The measured results of quality control of different phantoms are different.

OBJECTIVE: Cigarette smoking exacerbates the progression of pulmonary tuberculosis (TB). The role of tertiary lymphoid structures (TLS) in chronic lung diseases has gained attention; however, it remains unclear whether smoking-exacerbated lung damage in TB is associated with TLS. This study aimed to analyze the characteristics of pulmonary TLS in smokers with TB and to explore the possible role of TLS in smoking-related lung injury in TB. METHODS: Lung tissues from 36 male patients (18 smokers and 18 non-smokers) who underwent surgical resection for pulmonary TB were included in this study. Pathological and immunohistological analyses were conducted to evaluate the quantity of TLS, and chest computed tomography (CT) was used to assess the severity of lung lesions. The correlation between the TLS quantity and TB lesion severity scores was analyzed. The immune cells and chemokines involved in TLS formation were also evaluated and compared between smokers and non-smokers. RESULTS: Smoker patients with TB had significantly higher TLS than non-smokers ( P < 0.001). The TLS quantity in both the lung parenchyma and peribronchial regions correlated with TB lesion severity on chest CT (parenchyma: r = 0.5767; peribronchial: r = 0.7373; both P < 0.001). Immunohistochemical analysis showed increased B cells, T cells, and C-X-C motif chemokine ligand 13 (CXCL13) expression in smoker patients with TB ( P < 0.001). CONCLUSION Smoker TB patients exhibited increased pulmonary TLS, which was associated with exacerbated lung lesions on chest CT, suggesting that cigarette smoking may exacerbate lung damage by promoting TLS formation.
Humans ; Male ; Tuberculosis, Pulmonary/immunology* ; Middle Aged ; Tertiary Lymphoid Structures/pathology* ; Adult ; Lung/pathology* ; Smoking/adverse effects* ; Smokers ; Aged ; Tomography, X-Ray Computed