Background A diverse cohort of patients and susceptible individuals congregate in healthcare facilities, where exposure to pathogenic microorganisms associated with respiratory infectious diseases constitutes a significant risk factor for cross-infection. Central air-conditioning ventilation systems improve some indoor environment indicators while exacerbating the risk of transmission of respiratory infectious diseases. Objective To investigate the distribution characteristics of microbial communities in the central air-conditioning ventilation systems of hospitals, providing a scientific basis for the selection of microbial indicators in hygiene standards for hospital central air-conditioning ventilation systems and for hospital risk early warning systems. Methods In October 2023, two central air-conditioning ventilation systems were selected from a Grade 3A hospital in Shanghai: one was an all-air air-conditioning system serving the waiting area on the ground floor, and the other was a fan coil plus fresh air system serving the outpatient area on the third floor. Samples from four different components of the ventilation systems—air outlets, filters, surface coolers, and condensate trays—were collected for high-throughput sequencing of the 16S rRNA gene to analyze bacterial communities. Alpha-diversity and beta-diversity analyses were performed to investigate the microbial community composition and diversity characteristics of the hospital central air-conditioning ventilation systems. Functional analysis was conducted to determine the relative abundance of bacterial functions in these systems.Results A total of 528 operational taxonomic units (OTUs) were identified, encompassing 20 bacterial phyla, 37 classes, 79 orders, 123 families, and 240 genera. The analysis revealed that the bacterial community was predominantly composed of Proteobacteria, Gemmatimonadates, Bacteroidetes, and Actinobacteria. The diversity analysis indicated that bacterial community richness and diversity were highest in the condensate trays, while no statistically significant differences (P > 0.05) were observed in the bacterial community composition among the air outlets, filters, and surface coolers. The functional analysis showed that the bacterial communities in the central air-conditioning ventilation systems primarily exhibited chemoheterotrophic, oxidative energy-dependent heterotrophic, and ureolytic functional characteristics. Conclusion The dominance of Proteobacteria suggests that this phylum exhibits strong adaptability in the central air-conditioning ventilation systems, possibly related to its ability to survive and reproduce under varying environmental conditions. The diversity analysis indicates that the condensate tray is a critical area for bacterial proliferation in the central air-conditioning ventilation systems. The similarity in environmental conditions among the air outlets, filters, and surface coolers result in similar bacterial community structures. The functional analysis reveals that the bacterial communities possess robust energy conversion and metabolic capabilities, potentially contributing to processes such as organic matter decomposition and nitrogen cycling within the central air-conditioning ventilation systems.

Objective To evaluate the predictive ability and clinical application value of artificial intelligence (AI) systems in the benign and malignant differentiation and pathological type of pulmonary nodules, and to summarize clinical application experience. Methods A retrospective analysis was conducted on the clinical data of patients with pulmonary nodules admitted to the Department of Thoracic Surgery, Second Hospital of Lanzhou University, from February 2016 to February 2025. Firstly, pulmonary nodules were divided into benign and non-benign groups, and the discriminative abilities of AI systems and clinicians were compared. Subsequently, lung nodules reported as precursor glandular lesions (PGL), microinvasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC) in postoperative pathological results were analyzed, comparing the efficacy of AI systems and clinicians in predicting the pathological type of pulmonary nodules. Results In the analysis of benign/non-benign pulmonary nodules, clinical data from a total of 638 patients with pulmonary nodules were included, of which there were 257 males (10 patients and 1 patient of double and triple primary lesions, respectively) and 381 females (18 patients and 1 patient of double and triple primary lesions, respectively), with a median age of 55.0 (47.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis of the two groups of variables showed that, except for nodule location, the differences in the remaining variables were statistically significant (P<0.05). Multivariate logistic regression analysis showed that age, nodule type (subsolid pulmonary nodule), average density, spicule sign, and vascular convergence sign were independent influencing factors for non-benign pulmonary nodules, among which age, nodule type (subsolid pulmonary nodule), spicule sign, and vascular convergence sign were positively correlated with non-benign pulmonary nodules, while average density was negatively correlated with the occurrence of non-benign pulmonary nodules. The area under the receiver operating characteristic curve (AUC) of the malignancy risk value given by the AI system in predicting non-benign pulmonary nodules was 0.811, slightly lower than the 0.898 predicted by clinicians. In the PGL/MIA/IAC analysis, clinical data from a total of 411 patients with pulmonary nodules were included, of which there were 149 males (8 patients of double primary lesions) and 262 females (17 patients of double primary lesions), with a median age of 56.0 (50.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis results showed that, except for gender, nodule location, and vascular convergence sign, the differences in the remaining variables among the three groups of PGL, MIA, and IAC patients were statistically significant (P<0.05). Multinomial multivariate logistic regression analysis showed that the differences between the parameters in the PGL group and the MIA group were not statistically significant (P>0.05), and the maximum diameter and average density of the nodules were statistically different between the PGL and IAC groups (P<0.05), and were positively correlated with the occurrence of IAC as independent risk factors. The average AUC value, accuracy, recall rate, and F1 score of the AI system in predicting lung nodule pathological type were 0.807, 74.3%, 73.2%, and 68.5%, respectively, all better than the clinical physicians’ prediction of lung nodule pathological type indicators (0.782, 70.9%, 66.2%, and 63.7% respectively). The AUC value of the AI system in predicting IAC was 0.853, and the sensitivity, specificity, and optimal cutoff value were 0.643, 0.943, and 50.0%, respectively. Conclusion This AI system has demonstrated high clinical value in predicting the benign and malignant nature and pathological type of lung nodules, especially in predicting lung nodule pathological type, its ability has surpassed that of clinical physicians. With the optimization of algorithms and the adequate integration of multimodal data, it can better assist clinical physicians in formulating individualized diagnostic and treatment plans for patients with lung nodules.

Objective: To analyze the impact of persistent obesity on their lung function, so as to offer insights for implementing intervention measures to increase lung function in obese school age children. Methods: A total of 335 children from the Sheyang Mini Birth Cohort established in 2009 in Yancheng City, Jiangsu Province, who participated in the follow up at the ages of 7 years (2016) and 10 years (2019), were selected as the study participants. Physical measurements including height, weight, and lung function were recorded. According to the World Health Organization standard, that is, gender and age specific to correct the body mass index to calculate the body mass index Z score, was used to evaluate the obesity status of children at the age of 7 and 10. Children were divided into four groups, including sustained non obesity group, restored obesity group, newly classified obesity group, and persistent obesity group. Meanwhile, the lung function prediction equations recommended by the Global Lung Function Initiative were used to standardize the lung function indexes of children. Pulmonary function differences among these groups were examined, and the relationship between childhood obesity and pulmonary function was longitudinally analyzed using generalized estimating equations. Results: The prevalence of obesity were 9.0% and 16.1% at the age of 7 and 10 years, respectively. The proportion of both newly classified and persistent obesity group were 8.1%, respectively. The forced expiratory volume in one second (FEV 1) and forced vital capacity (FVC) were (1 269.90±202.70) and (1 415.70±230.00) mL, respectively, at the age of 7 years. FEV 1 and FVC at the age of 10 years were (1 440.80±403.20) and (1 555.60±517.60) mL, respectively. Cross sectional analysis at age 7 showed that forced expiratory flow at 75% vital capacity (FEF 75 ) ( β=-0.52, 95%CI =-0.96--0.07) and maximal mid expiratary flow (MMEF) ( β=-0.45, 95%CI =-0.89--0.00) were significantly lower in obese children compared to their non obese peers ( P < 0.05). Longitudinal analysis indicated that obese children had lower levels of lung pulmonary function, with a statistically significant difference in FEV 1 ( β=-0.44, 95%CI=-0.85--0.02, P <0.05). There was no significant difference among the various obesity groups ( P >0.05), while gender stratified results revealed significant reductions in FEV 1/FVC in newly classified obese girls at age 10 years ( β=-1.76, 95%CI =-3.13--0.38) and in MMEF in persistently obese girls at age 10 years ( β=-1.44, 95%CI = -2.79- -0.09) ( P <0.05). Conclusion Obesity may contribute to reduced lung function levels in school aged children, with newly classified and persistent obesity having more pronounced effects on lung function in girls.

Objective To investigate the expression of PLCD3 mRNA in the synovium of osteoarthritis(OA)and its relationship with immune cell infiltration.Methods Based on the differentially expressed genes of OA found in the previous study,the expression of phospholipase Cδ3(PLCD3)mRNA was detected by col-lecting synovial samples from OA group and control group.CIBERSORT algorithm was used to analyze the infiltration pattern of immune cells in OA group and control group,and the correlation between PLCD3 and infiltrating immune cells was further analyzed.Results Compared with the control group,the relative expres-sion level of PLCD3 mRNA was significantly increased in synovial samples of OA group(P<0.05).The pro-portions of B cells naive,NK cells activated,M2 macrophages and mast cells activated in synovial tissues of OA group were relatively high(P<0.05).PLCD3 was positively correlated with the proportion of these four immune cells(P<0.05).Conclusion PLCD3 may be a key biomarker for the diagnosis of OA,which may be involved in the pathogenesis of OA by interacting with infiltrating immune cells.

A major impedance to neuronal regeneration after peripheral nerve injury(PNI)is the activation of various programmed cell death mechanisms in the dorsal root ganglion.Ferroptosis is a form of pro-grammed cell death distinguished by imbalance in iron and thiol metabolism,leading to lethal lipid peroxidation.However,the molecular mechanisms of ferroptosis in the context of PNI and nerve regeneration remain unclear.Ferroportin(Fpn),the only known mammalian nonheme iron export protein,plays a pivotal part in inhibiting ferroptosis by maintaining intracellular iron homeostasis.Here,we explored in vitro and in vivo the involvement of Fpn in neuronal ferroptosis.We first delineated that reactive oxygen species at the injury site induces neuronal ferroptosis by increasing intracellular iron via accelerated UBA52-driven ubiquitination and degradation of Fpn,and stimulation of lipid peroxidation.Early administration of the potent arterial vasodilator,hydralazine(HYD),decreases the ubiquitination of Fpn after PNI by binding to UBA52,leading to suppression of neuronal cell death and significant ac-celeration of axon regeneration and motor function recovery.HYD targeting of ferroptosis is a promising strategy for clinical management of PNI.

Objective:To analyze the methylation characteristics of the lymphocyte-specific protein-tyrosine kinase (LCK) promoter region in the peripheral blood circulation of rheumatoid arthritis (RA) patients and its correlation with clinical indicators.Methods:Targeted methylation sequencing was used to compare the methylation levels of 7 CpG sites in the LCK promoter region in the peripheral blood of RA patients with healthy controls (HC) and osteoarthritis (OA) patients. Correlation analysis and ROC curve construction were performed with clinical information.Results:Non-parametric tests revealed that compared with HC [0.53(0.50, 0.57)] and OA patients [0.59(0.54, 0.62), H=47.17, P<0.001], RA patients [0.63(0.59, 0.68)] exhibited an overall increase in methylation levels. Simultaneously, when compared with the HC group [0.38(0.35, 0.41), 0.59(0.55, 0.63), 0.60(0.55, 0.64), 0.59(0.55, 0.63), 0.58(0.53, 0.62), 0.45(0.43, 0.49), 0.57(0.54, 0.61)], the RA group [0.46(0.42, 0.49), 0.70(0.65, 0.75), 0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] showed a significant elevation in methylation levels at CpG sites cg05350315_60, cg05350315_80, cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-5.63, -5.89, -5.91, -5.89, -5.98, -5.95, -5.95, all P<0.001). Compared with the OA group [0.65(0.59, 0.69), 0.65(0.60, 0.69), 0.64(0.58, 0.68), 0.50(0.45, 0.54), 0.63(0.58, 0.67)], the RA group [0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] exhibited a significant increase in methylation levels at CpG sites cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-3.56, -3.52, -3.60, -3.67, -3.62; P=0.036, 0.042, 0.031, 0.030, 0.030). Furthermore, Pearson correlation coefficient analysis revealed a positive correlation between the overall methylation level in this region and C-reactive protein (CRP) ( r=0.19, P=0.004) and erythrocyte sedimentation rate ( r=0.14, P=0.035). The overall methylation level of the LCK promoter region in the CRP (low) group [0.63 (0.58, 0.68)] was higher than that in the CRP (high) group [0.65(0.61, 0.70)], with statistically significant differences ( Z=2.60, P=0.009). Finally, by constru-cting a ROC curve, the discriminatory efficacy of peripheral blood LCK promoter region methylation levels for identifying RA patients, especially seronegative RA patients, from HC and OA groups was validated, with an AUC value of 0.78 (95% CI: 0.63, 0.93). Conclusion:This study provides insights into the methylation status and methylation haplotype patterns of the LCK promoter region in the peripheral blood of RA patients. The overall methylation level in this region is positively correlated with the level of inflammation and can be used to differentiate seronegative RA patients from the HC and OA patients.

Objective:To analyze the clinical characteristics, imaging, myopathology and outcomes of patients with COVID-19 related autoimmune myopathy.Methods:The clinical features, serum creatine kinase (CK), myositis antibodies, muscle magnetic resonance imaging, myopathology and therapy of 5 patients with COVID-19 related autoimmune myopathy diagnosed in Peking University First Hospital from December 2022 to April 2023 were collected. The effects of the therapy after a short term follow up were analyzed.Results:Among the 5 patients, there were 3 males and 2 females, with onset age of 42-86 years. All patients presented with proximal muscle weakness in the recovery term of COVID-19. Myalgia was noted in 3 cases, dysphagia in 1, skin damage in 2, interstitial lung disease in 1. The serum CK of the 5 patients was 1 663-16 000 IU/L, 1 patient had anti-3-hydroxy-3-methylglutaryl-CoA reductase autoantibodies and 1 patient had anti-signal recognition particle autoantibodies. The electromyography showed myogenic lesions in all patients. Muscle magnetic resonance imaging showed diffuse muscle edema in all patients, myofascial edema in 3 and subcutaneous-tissue edema in 3. The muscle biopsies in 4 patients revealed necrotic myopathy,with high P62 expression in muscle fibers. The electromicroscopy of 2 patients revealed vacuolated mitochondria and intranuclear tubulofilamentous inclusions in muscle fibers. Four patients were treated with glucocorticoids, of whom 2 patients combined with intravenous immunoglobulin, tacrolimus or cyclophosphamide. One case had close monitoring without drug therapy. They showed significant improvement, but the CK was still abnormal in 4 patients.Conclusions:COVID-19 leads to immune mediated myopathy. The manifestation of patients is characterized by proximal predominant weakness and high creatine kinase level. Muscle magnetic resonance imaging shows diffuse muscle edema. The muscle biopsies reveal necrotic myopathy. The effectiveness of immunosuppression needs to be further studied.

Objective:To study positive rates and typing of oligoclonal bands (OCB) in patients with neurological disorders, and to reveal the clinical significance and applicational value of OCB test.Methods:A retrospective analysis was performed on the detection results of 3 217 patients with neurological disorders who undertook both serum and cerebrospinal fluid OCBs in the First Hospital of Peking University from January 2012 to August 2022. According to the final diagnosis, the patients were divided into 13 groups including multiple sclerosis (479 cases), neuromyelitis optica spectrum disorders (935 cases), autoimmune encephalitis (192 cases), viral encephalitis (94 cases), nervous system complication after HSCT (232 cases), Guillain-Barré syndrome (644 cases), chronic inflammatory demyelinating polyneuropathy (157 cases), etc. Cerebrospinal fluid and serum OCBs were detected using isoelectric focusing electrophoresis combining immunofixation, then classified into Ⅰ-Ⅴ types according to the morphology. Consequently, positive rates and types were analyzed for each group. χ2 test was used for comparison between groups. Results:The positive rates of cerebrospinal fluid OCB in multiple sclerosis, nervous system complication after hematopoietic stem cell transplantation (HSCT), autoimmune encephalitis, viral encephalitis, neuromyelitis optica spectrum disorders, Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy were respectively 66.8% (320/479), 48.7% (113/232), 46.4%(89/192), 19.1% (18/94), 17.6% (165/935), 9.9% (64/644), 5.1% (8/157). For patients with multiple sclerosis, neuromyelitis optica spectrum disorders, viral encephalitis, and autoimmune encephalitis, Type Ⅱ bands took the majority of cerebrospinal fluid OCB-positive cases with the rates of 94.1% (301/320), 78.7% (70/89), 77.8% (14/18), and 77.6% (128/165) respectively, indicating intrathecal IgG synthesis; for patients with nervous system complication after HSCT, Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, type Ⅳ bands took the majority of cerebrospinal fluid OCB-positive cases with the rates of 94.7% (107/113), 82.8% (53/64) and 100% (8/8), indicating no obvious intrathecal IgG synthesis. The positive rates of cerebrospinal fluid oligoclonal bands were significantly different among all groups (χ 2=1 268.31, P<0.001). Conclusion:The positive rates of cerebrospinal fluid oligoclonal bands are different among different neurological disorders, in which the positive rate of cerebrospinal fluid OCB is higher with type Ⅱ bands as the majority type in multiple sclerosis, which indicates that the detection and typing of cerebrospinal fluid OCB are helpful for the diagnosis of various neurological diseases, especially for multiple sclerosis.

Background Perfluorinated and polyfluoroalkyl substances (PFAS), a large group of emerging pollutants, are ubiquitous in the ecological environment. Their multiple organ toxic effects on human body are reported. Understanding the exposure level of PFAS in cord serum and associated influencing factors can provide scientific evidence for studying maternal and newborn health effects and risk regulation. Objective To explore the exposure levels of PFAS in cord serum and potential impact factors. Methods This study was based on the maternal and infant database and the cord serum sample bank of the Sheyang Mini Birth Cohort Study (SMBCS) established in 2009. A self-designed questionnaire was used to collect information on sociodemographic characteristics, living environment, and lifestyle of mothers during pregnancy. A total of 1097 cord serum samples were measured utilizing ultra-high performance liquid chromatography-Q-Exactive Orbitrap high-resolution mass spectrometry. Multiple linear regression models were used to identify influencing factors related to PFAS exposure level in cord serum. Results A total of 38 types of PFAS were detected in the cord serum samples, including 20 perfluorocarboxylic acids (PFCA), 14 perfluorosulfonic acids (PFSA), and 4 other types of PFAS. The detection rates of 14 PFAS compounds were above 50%. The detection rates of perfluoro-1-hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA) were in the range of 99.18%-100.00%. The median concentrations of PFOA and 6∶2 chlorinated polyfluorinated ether sulfonic acid (6∶2CI-PFESA) were higher than those of the other compounds, which were 3.76 µg·L⁻¹ and 2.61 µg·L⁻¹, respectively. The correlation coefficients among cord serum PFAS were in the wide range of 0.0911-0.8429 (P < 0.05). The associations between PFHxS and perfluoro-1-heptanesulfonic acid (PFHpS) (r=0.8429, P < 0.05), PFOS and PFHpS (r=0.7012, P < 0.05), and PFUdA and perfluorododecanoic acid (PFDoA) (r=0.7875, P < 0.05) were positive. The proportions of PFCA and PFSA in the cord serum samples were 60.1% and 38.4%, respectively. PFOA and 6∶2 Cl-PFESA were the predominant compounds in the cord serum samples, whose proportions were 37.8% and 19.3%, respectively. The concentrations of specific types of cord serum PFAS had varied associations with the following demographic variables of pregnant women: age, parity, education level, gestational age, and occupation. The multiple linear regression analysis found that the concentrations of 8 PFAS (PFHxS, PFHpS, PFNA, PFOS, PFDA, PFUdA, PFDoA, and 6∶2 CI-PFESA) in umbilical cord serum were lower in pregnant women aged 25 years and older than in those under the age of 25 years; compared to pregnant women with education levels at or below junior middle school, those with education levels at or above high school had lower concentrations of perfluoroheptanoic acid (PFHpA); the concentration of PFHpA in cord serum was negatively correlated with household annual income; multiparous women had higher concentrations of PFNA, PFUdA, and PFDoA than primiparous women; compared to mothers engaged in manual labor, the concentration of perfluoro-1-butanesulfonic acid (PFBS) in umbilical cord serum was lower in mothers engaged in mental labor, while the concentrations of PFBS and PFOA were lower and the concentrations of perfluorotridecanoic acid (PFTrDA) and 8∶2 chlorinated polyfluorinated ether sulfonic acid (8∶2CI-PFESA) were higher in mothers of other occupational types; the concentrations of umbilical cord serum PFOA, PFOS, PFUdA, and PFDoA were positively correlated with the gestational age of pregnant women, while N-methylperfluoro-1-octanesulfonamido acetic acid (N-MeFOSAA) was negatively correlated with the gestational age of pregnant women; PFTrDA was negatively correlated with the birth weight of newborns; compared with those with insufficient gestational weight gain, those with adequate gestational weight gain had lower PFDoA, while those with excess gestational weight gain had higher N-MeFOSAA. Conclusion PFAS compounds exposure is common in the mothers and infants in the study area. PFOA and 6∶2 CI-PFESA are the two main compounds in cord serum. Cord serum PFAS are associated with several demographic characteristics of the pregnant women. Future research needs to pay more attention to PFAS alternatives and other emerging contaminants.

Objective Chlorination is often used to disinfect recreational water in large amusement parks;however,the health hazards of chlorination disinfection by-products(DBPs)to occupational populations are unknown.This study aimed to assess the exposure status of chlorinated DBPs in recreational water and the health risks to employees of large amusement parks. Methods Exposure parameters of employees of three large amusement parks in Shanghai were investigated using a questionnaire.Seven typical chlorinated DBPs in recreational water and spray samples were quantified by gas chromatography,and the health risks to amusement park employees exposed to chlorinated DBPs were evaluated according to the WHO's risk assessment framework. Results Trichloroacetic acid,dibromochloromethane,bromodichloromethane,and dichloroacetic acid were detected predominantly in recreational water.The carcinogenic and non-carcinogenic risks of the five DBPs did not exceed the risk thresholds.In addition,the carcinogenic and non-carcinogenic risks of mixed exposure to DBPs were within the acceptable risk limits. Conclusion Typical DBPs were widely detected in recreational water collected from three large amusement parks in Shanghai;however,the health risks of DBPs and their mixtures were within acceptable limits.