Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

Objective To evaluate the rabbit modle of frozen shoulder induced by persistent strain injuries and ice com-pression.Methods Twelve clean,healthy male New Zealand rabbits with a mass of(2 500±500)g were selected and randomly divided into a blank group and a control group with 6 rabbits in each group.In the control group,the rabbits were modeled with persistent strain injuries and ice compression,the general conditions of the rabbits and the active and passive activities of the shoulder joint were observed and their body weights were recorded.MRI was performed on the affected shoulder joints at 6 d and 29 d after modelling to observe the fluid and soft tissue;HE staining was used to observe the morphology of the rabbit bi-ceps longus tendon and the synovial membrane of the joint capsule;Masson staining was used to observe the fibrous deposits of the rabbit biceps longus tendon and the synovial membrane of the joint capsule,and the fibrous deposits were analysed semi-quantitatively by Image J software.Results Six days after the end of modeling,the active movement of the shoulder joints in the control group was limited,the passive movement was not significantly limited,and they walked with a limp;29 days after the end of the modeling,the active and passive movements of the shoulder joints in the model group were severely limited.Com-pared with the blank group(2.50±0.14)kg,the body weight of the model group(2.20±0.17)kg was significantly reduced(P＜0.01).MRI showed that 6 days after modelling,the muscles around the shoulder joint were not smooth in shape,the joint cap-sule structure was narrowed and a large amount of fluid was seen in the joint cavity;29 days after modelling,the muscles around the shoulder joint were rough in shape,structure of the joint capsule was unclear and the fluid in the joint cavity was reduced compared with 6 days after modelling.Pathological staining showed that the long-headed biceps tendon fibres in the control group were disorganised,curled or even broken,and the synovial tissue of the joint capsule was heavily vascularised,with col-lagen fibre deposits and severe inflammatory cell infiltration.The fiber deposition of the long head of biceps brachii in the mod-el group[(23.58±3.41)％,(27.56±3.70)％]and synovial tissue[(41.78±5.59)％,(62.19±7.54)％]were significantly higher than those in the blank group[(1.79±1.03)％,(1.29±0.63)％]at 7 and 30 days after modeling and synovial tissue fiber de-position[(8.15±3.61)％,(11.29±7.10)％],as shown by the semi-quantitative analysis of Masson staining results by Image J software.And the longer the time,the more severe the fibrosis(P＜0.01).Conclusion The behavioral,imaging and pathological findings showed that the rabbit frozen shoulder model with persistent strain injuries and ice compression is consistent with the clinical manifestations and pathogenesis of periarthritis,making it an ideal method for periarthritis research.

Objective:To evaluate the usability of Gafchromic HD-V2 film for dose dosimetry in the ultra-high dose-rate (UD) electron beam from a modified medical linac, and to investigate the response between the energy and dose-rate dependence to the film.Methods:The HD-V2 film was utilized to measure the average dose-rate of the UD electron beam. The measured result was compared with those by advanced Markus chamber and alanine pellets. And characteristics of the UD electron beam were also measured by HD-V2 film. Energy dependence of HD-V2 film at three beam energies (6 MV X-ray, 9 MeV and 16 MeV electron beam) was investigated by obtaining and comparing the calibration curves based on the clinical linear accelerator in the dose range of 10-300 Gy. The dose-rate dependence of HD-V2 film was also studied by varying the dose rate among 0.03 Gy/s, 0.06 Gy/s and 0.1 Gy/s, and range of 100-200 Gy/s.Results:The measured average maximum dose-rate of 9 MeV UD electron beam at source skin distance (SSD) 100 cm was approximately 121 Gy/s using HD-V2 film, consistent with the results by advanced Markus chamber and alanine pellets. The measured percentage depth dose (PDD) curve parameters of the UD electron beam were similar to the conventional 9 MeV beam. The off-axis dose distribution of the UD electron beam showed the highest central axis, and the dose was gradually decreased with the increase of off-axis distance. The energy dependence of HD-V2 film had no dependency of 6 MV and 9, 16 MeV while measuring the dose in the range from 20 to 300 Gy. The HD-V2 film had no significant dose-rate dependency at the dose rate of 0.03 Gy/s, 0.06 Gy/s and 0.1 Gy/s for the clinical linear accelerator. Likewise, there was also no dose-rate dependence in the range 100-200 Gy/s in the modified machine.Conclusion:HD-V2 film is suitable for measuring ultra-high dose rate electron beam, independent of energy and dose rate.

Objective: To investigate the serotypes and drug resistance of non-typhoidal Salmonella in Zhengzhou City, so as to provide insights into prevention and control of non-typhoidal Salmonella infections. Methods: Salmonella isolates were collected from diarrheal patients in Zhengzhou municipal sentinel hospitals from 2017 to 2021. Salmonella serotypes were identified using slide agglutination test and soft agar colony formation assay, and antimicrobial susceptibility test was performed using the broth micro-dilution method. Results: Five serogroups and 37 serotypes were identified among 446 non-typhoidal Salmonella isolates, with S. enteritidis (210 isolates, 47.09%) and S. typhimurium (133 isolates, 29.82%) as dominant serotypes. Non-typhoidal Salmonella showed high resistance to ampicillin (79.60%), ampicillin/sulbactam (58.74%), naphthyric acid (56.05%), tetracycline (54.26%) and doxycycline (54.04%), respectively. There were 290 multidrug-resistant Salmonella isolates (65.02%), and the multidrug resistance rates were 70.48% for S. enteritidis and 67.67% for S. typhimurium, respectively. Conclusions Multiple serotypes of non-typhoidal Salmonella were identified in Zhengzhou City from 2017 to 2021, with S. enteritidis and S. typhimurium as dominant serotypes. Widespread drug resistance and multidrug resistance was seen in non-typhoidal Salmonella.

BACKGROUND: Although intensively studied in patients with cardiovascular diseases (CVDs), the prognostic value of diastolic blood pressure (DBP) has little been elucidated in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study aimed to reveal the prognostic value of DBP in AECOPD patients. METHODS: Inpatients with AECOPD were prospectively enrolled from 10 medical centers in China between September 2017 and July 2021. DBP was measured on admission. The primary outcome was all-cause in-hospital mortality; invasive mechanical ventilation and intensive care unit (ICU) admission were secondary outcomes. Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regressions were used to identify independent prognostic factors and calculate the hazard ratio (HR) and 95% confidence interval (CI) for adverse outcomes. RESULTS: Among 13,633 included patients with AECOPD, 197 (1.45%) died during their hospital stay. Multivariable Cox regression analysis showed that low DBP on admission (<70 mmHg) was associated with increased risk of in-hospital mortality (HR = 2.16, 95% CI: 1.53-3.05, Z = 4.37, P <0.01), invasive mechanical ventilation (HR = 1.65, 95% CI: 1.32-2.05, Z = 19.67, P <0.01), and ICU admission (HR = 1.45, 95% CI: 1.24-1.69, Z = 22.08, P <0.01) in the overall cohort. Similar findings were observed in subgroups with or without CVDs, except for invasive mechanical ventilation in the subgroup with CVDs. When DBP was further categorized in 5-mmHg increments from <50 mmHg to ≥100 mmHg, and 75 to <80 mmHg was taken as reference, HRs for in-hospital mortality increased almost linearly with decreased DBP in the overall cohort and subgroups of patients with CVDs; higher DBP was not associated with the risk of in-hospital mortality. CONCLUSION: Low on-admission DBP, particularly <70 mmHg, was associated with an increased risk of adverse outcomes among inpatients with AECOPD, with or without CVDs, which may serve as a convenient predictor of poor prognosis in these patients. CLINICAL TRIAL REGISTRATION Chinese Clinical Trail Registry, No. ChiCTR2100044625.
Humans ; Blood Pressure ; Pulmonary Disease, Chronic Obstructive/therapy* ; Cohort Studies ; Respiration, Artificial ; Inpatients ; Hospital Mortality

Objective: To understand the performance of 2019-nCoV nucleic acid detection in screening of contacts of COVID-19 cases in same flights and provide evidence for the effective screening of persons at high risk for the infection in domestic flights. Methods: The information of passengers who took same domestic flights with COVID-19 cases in China from April 1, 2020 to April 30, 2022 were retrospectively collected,and χ² test was used to analyze positive nucleic acid detection rates in the passengers in different times before the onsets of the index cases, in different seat rows and in epidemic periods of different 2019-nCoV variants. Results: During the study period, a total of 433 index cases were identified among 23 548 passengers in 370 flights. Subsequently, 72 positive cases of 2019-nCoV nucleic acid were detected in the passengers, in whom 57 were accompanying persons of the index cases. Further analysis of the another 15 passengers who tested positive for the nucleic acid showed that 86.67% of them had onsets or positive detections within 3 days after the diagnosis of the index cases, and the boarding times were all within 4 days before the onsets of the index cases. The positive detection rate in the passengers who seated in first three rows before and after the index cases was 0.15% (95%CI: 0.08%-0.27%), significantly higher than in the passengers in other rows (0.04%, 95%CI: 0.02%-0.10%, P=0.007),and there was no significant difference in the positive detection rate among the passengers in each of the 3 rows before and after the index cases (P=0.577). No significant differences were found in the positive detection rate in the passengers, except the accompanying persons, among the epidemics caused by different 2019-nCoV variants (P=0.565). During the Omicron epidemic period, all the positive detections in the passengers, except the accompanying persons, were within 3 days before the onset of the index cases. Conclusions: The screening test of 2019-nCoV nucleic acid can be conducted in the passengers took the same flights within 4 days before the onsets of the index cases on board. Passengers who seated within 3 rows from the index cases can considered as the close contacts at high risk for 2019-nCoV, for whom screening should be conducted first and special managements are needed. The passengers in other rows can be classified as general risk persons for screening and management.
Humans ; COVID-19 ; Retrospective Studies ; SARS-CoV-2 ; China ; Nucleic Acids

ObjectiveTo observe the effects of modified Chaihu Shugansan（CHSG） and its disassembled formulas on angiotensin-converting enzyme 2 （ACE2）-angiotensin （Ⅰ-Ⅶ） ［Ang （Ⅰ-Ⅶ）］-mitochondrial assembly receptor （MasR） axis in hyperlipidemic rats with myocardial ischemia and depression， and to explore the underlying mechanism of its prevention and treatment of myocardial ischemia and depression. MethodA total of 108 male SD rats were randomly divided into a normal group， a model group， a modified CHSG group （11.7 g·kg^-1）， a Quyu Huatan disassembled formula group （4.05 g·kg^-1）， a Shugan Xingqi disassembled formula group （3.15 g·kg^-1）， a Jianpi Yangxue disassembled formula group （4.5 g·kg^-1）， a fluoxetine group （0.001 8 g·kg^-1）， a trimetazidine group （0.005 4 g·kg^-1）， and a simvastatin group （0.001 8 g·kg^-1）， with 12 rats in each group. The hyperlipidemia model with myocardial ischemia and depression was induced with a high-fat diet combined with injection of isoproterenol （ISO） and chronic unpredictable mild stress （CUMS） in rats in the model group and groups with drug intervention for eight weeks. The rats in each group with drug intervention were treated correspondingly by gavage from the first day of modeling， while those in the normal group and the model group received the same amount of normal saline. The behavioral changes of rats in each group were observed by open field test and forced swimming test. Left ventricular fractional shortening （LVFS） and left ventricular ejection fraction （LVEF） were measured by echocardiography. The serum levels of total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C） were detected by the enzyme-labeled apparatus. Hematoxylin-eosin （HE） staining was used to observe the histomorphological changes of the heart. The serum levels of angiotensin Ⅱ （AngⅡ）， ACE2， and Ang（Ⅰ-Ⅶ） were detected by enzyme-linked immunosorbent assay （ELISA）. The protein and mRNA expression of ACE2 and MasR in the hippocampus and the heart was detected by real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCompared with the normal group， the model group showed reduced movement time， distance， and average speed in the central area of the open field （P<0.01）， prolonged immobility time of rats in the forced swimming test （P<0.01）， decreased LVFS and LVEF （P<0.01）， inflammatory exudation and disorderly arranged fiber in heart tissues， elevated serum levels of TC， LDL-C， AngⅡ， ACE2 and Ang（Ⅰ-Ⅶ）， diminished HDL-C （P<0.01）， dwindled mRNA and protein expression of ACE2 in the hippocampus and the heart and MasR in the hippocampus， and up-regulated mRNA and protein expression of MasR in the heart （P<0.01）. Compared with the model group， the modified CHSG group displayed increased movement time， distance， and average speed in the center area of the open field （P<0.01）， shortened immobility time in the forced swimming test （P<0.01）， increased LVFS and LVEF （P<0.01）， relieved heart injury， reduced serum levels of TC， LDL-C， AngⅡ， ACE2， and Ang（Ⅰ-Ⅶ）， elevated level of HDL-C （P<0.01）， up-regulated mRNA and protein expression of ACE2 in the hippocampus and the heart and MasR in the hippocampus， and down-regulated mRNA and protein expression of MasR in the heart （P<0.01）. Each disassembled formula could improve the above indexes to a certain extent （P<0.05， P<0.01）， but the effect of the whole formula was optimal. ConclusionThe modified CHSG and its disassembled formulas have the effects of resisting depression， improving myocardial injury， and reducing blood lipid. Due to the synergistic effects of stasis-resolving/phlegm-eliminating drugs， liver-smoothing/Qi-moving drugs， and spleen-tonifying/blood-nourishing drugs in the formula， the modified CHSG is superior to each disassembled formula in efficacy. Its mechanism may be related to the activation of the ACE2-Ang （Ⅰ-Ⅶ）-MasR axis.

Objective: To analyze the pathogenic spectrum of infectious diarrhea among children in Zhengzhou City in 2020, so as to provide insights into the management of childhood infectious diarrhea. Methods: A total of 230 stool samples were collected from children with diarrhea in the Diarrhea Clinic of Zhengzhou Municipal Children's Hospital in 2020. Diarrheagenic Escherichia coli, Salmonella, Shigella, Vibrio parahaemolyticus, Campylobacter and Aeromonas were isolated. Salmonella was typed using pulsed-field gel electrophoresis ( PFGE ) and antimicrobial resistance was tested in Salmonella. The main types and drug resistance of pathogens were descriptively analyzed. Results: The 230 children with diarrhea included 152 males and 78 females, with a male to female ratio of 1.95∶1. There were 173 cases at ages of 3 years and below ( 75.22% ), and 82 cases seen between June and August ( 35.65% ). A total of 71 pathogenic bacteria strains were isolated, with a detection rate of 30.87%. Salmonella was the most frequently isolated pathogen ( 35 strains, 15.22% prevalence ), following by diarrheagenic E. coli ( 20 strains, 8.70% ). Eleven serotypes of Salmonella were identified, which mainly included S. enteritidis and S. typhimurium. PFGE typing revealed 25 band patterns of Salmonella, with a similarity ranging from 11.85% to 100%. Salmonella were sensitive to imipenem, meropenem, polymyxin B and amikacin and highly resistant to streptomycin ( 85.71% ), ampicillin ( 80.00% ) and sulfaisoxazole ( 80.00% ). A 82.86% proportion of multi-drug resistance was detected in the 29 Salmonella strains. Conclusions A wide range of pathogenic bacteria were detected from the childhood infectious diarrhea in Zhengzhou City in 2020, which mainly included Salmonella and diarrheagenic E. coli. A high polymorphism level was seen in PFGE fingerprints of Salmonella, which presented high-level resistance to antimicrobial agents.

Acute Disease ; Aneurysm, Dissecting/surgery* ; Aortic Aneurysm/surgery* ; Hospitals ; Humans ; Retrospective Studies ; Treatment Outcome

According to human carboxylesterase 2(hCE2) inhibitors reported in the literature, the pharmacophore model of hCE2 inhibitors was developed using HipHop module in Discovery Studio 2016. The optimized pharmacophore model, which was validated by test set, contained two hydrophobic, one hydrogen bond acceptor, and one aromatic ring features. Using the pharmacophore model established, 5 potential hCE2 inhibitors(CS-1,CS-2,CS-3,CS-6 and CS-8) were screened from 20 compounds isolated from the roots of Paeonia lactiflora, which were further confirmed in vitro, with the IC_(50) values of 5.04, 5.21, 5.95, 6.64 and 7.94 μmol·L~(-1), respectively. The results demonstrated that the pharmacophore model exerted excellent forecasting ability with high precision, which could be applied to screen novel hCE2 inhibitors from Chinese medicinal materials.
Carboxylesterase/metabolism* ; Humans ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions