BACKGROUND:Changes in skeletal muscle mass have been indicated in studies addressing the effects of low-frequency pulsed magnetic fields on the structure and morphology of the skeletal muscle,but no relevant studies have been conducted on the morphologic changes that occur after chronic exposure to the low-frequency pulsed magnetic field. OBJECTIVE:To observe the effects of chronic exposure to low-frequency pulsed magnetic fields on the maximal voluntary contraction and morphologic indicators of the quadriceps muscle of the leg,thereby providing a reference of muscle morphologic changes for the use of this technique as a strategy for muscle function improvement. METHODS:Seventy healthy subjects were recruited and randomly divided into a test group that received magnetic field stimulation and a control group that underwent sham treatment,with 35 subjects in each group,and the total duration of the trial was 4 weeks.The test group underwent low-frequency pulsed magnetic stimulation for 15 minutes every 48 hours,while the control group underwent sham treatment,with the same intervention interval and duration as the test group.After 4 weeks of intervention,changes in the maximum voluntary contraction value of the quadriceps muscle in different groups were observed,and B-mode ultrasonography was utilized as a means of assessment to observe changes in muscle thickness,muscle cross-sectional area,and pinnation angle indexes. RESULTS AND CONCLUSION:After 4 weeks of chronic exposure to low-frequency pulsed magnetic fields,68 subjects completed the test.The maximum voluntary contraction value of the quadriceps muscle in the test group increased significantly(P=0.000),and the increment was significantly higher than that of the control group(P=0.008).Three indexes related to muscle morphology in the test group were significantly higher than the pre-test values(P=0.000),while in the control group,muscle thickness showed a significant reduction(P=0.020),there was no significant change in the pinnation angle,but a significant increase in the cross-sectional area(P=0.000).Intergroup comparisons revealed that the three indicators related to muscle morphology,including muscle thickness(P=0.012),pinnation angle(P=0.003),and cross-sectional area(P=0.049),were significantly higher in the test group than in the control group.The above data confirmed that the maximum voluntary contraction of the quadriceps muscle was significantly increased in healthy adults after 4 weeks of chronic exposure to the low-frequency pulsed magnetic field,and significant increases in the three muscle morphometric indices of muscle thickness,cross-sectional area,and pinnation angle were observed in the test group,providing a basis of muscle tissue morphology for the use of this technique as an exercise alternative and medical treatment strategy for muscle improvement.

BackgroundPost-traumatic stress symptoms （PTSS） is highly prevalent in adolescents who have experienced earthquake， which seriously threatens their physical and mental health， yet there is currently a lack of research on the effects of loneliness， social support and social media use on PTSS among post-earthquake adolescents. ObjectiveTo assess the PTSS among adolescents experiencing MS6.0 Luxian， Sichuan， earthquake on 16 September 2021， and to investigate the effects of loneliness， social support and social media use on PTSS， so as to provide references for the intervention of PTSS among post-earthquake adolescents. MethodsOn November 12， 2021， simple random sampling technique was used to select 2 522 post-earthquake adolescents in Luxian county of Luzhou city in Sichuan province. All subjects were assessed using Post-Traumatic Stress Disorder Checklist for DSM-5 （PCL-5）， Multidimensional Scale of Perceived Social Support （MSPSS）， Short-form UCLA Loneliness Scale （ULS-3） and Social Media Use Scale （SM-10）. Binary Logistic regression was used to determine the factors influencing PTSS among post-earthquake adolescents. ResultsPTSS was detected in 91 （3.61%） adolescents. Binary Logistic regression revealed that perceived social support from family members （OR=0.926， 95% CI： 0.879~0.976） was a protective factor for PTSS among post-earthquake adolescents. Lack of companionship （OR=1.764， 95% CI： 1.141~2.727）， feeling isolated （OR=2.037， 95% CI： 1.282~3.236）， and viewing negative emotional response of disaster victims through social media （OR=1.615， 95% CI： 1.291~2.020） were risk factors for PTSS among post-earthquake adolescents. ConclusionLack of companionship， feeling isolated， and viewing negative emotional response of disaster victims through social media pose a negative impact on PTSS among post-earthquake adolescents， while perceived social support from family members exert a positive impact on PTSS among post-earthquake adolescents. ［Funded by Humanity and Social Science Youth foundation of Ministry of Education of China （number， 22YJC190019）； Natural Science Foundation of Sichuan Province （number， 2023NSFSC1486）］

Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

In a healthy human, the airway mucus forms a thin, protective liquid layer covering the surface of the respiratory tract. It comprises a complex blend of mucin, multiple antibacterial proteins, metabolic substances, water, and electrolytes. This mucus plays a pivotal role in the lungs' innate immune system by maintaining airway hydration and capturing airborne particles and pathogens. However, heightened mucus secretion in the airway can compromise ciliary clearance, obstruct the respiratory tract, and increase the risk of pathogen colonization and recurrent infections. Consequently, a thorough exploration of the mechanisms driving excessive airway mucus secretion is crucial for establishing a theoretical foundation for the eventual development of targeted drugs designed to reduce mucus production. Across a range of lung diseases, excessive airway mucus secretion manifests with unique characteristics and regulatory mechanisms, all intricately linked to mucin. This article provides a comprehensive overview of the characteristics and regulatory mechanisms associated with excessive airway mucus secretion in several prevalent lung diseases.
Humans ; Mucus/metabolism* ; Mucins/physiology* ; Lung Diseases/metabolism* ; Respiratory Mucosa/metabolism* ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Asthma/physiopathology* ; Cystic Fibrosis/physiopathology* ; Mucociliary Clearance/physiology*

Abelmoschi Corolla, the dried corolla of Abelmoschus manihot, has anti-inflammatory, antioxidant, and anti-fibrosis activities. Its chemical constituents mainly include flavonoids, organic acids, steroids, and polysaccharides. This study reviewed the research progress in the chemical constituents and pharmacological activities of Abelmoschi Corolla in recent 20 years. According to the concept of quality marker(Q-marker), the Q-markers of Abelmoschi Corolla were predicted from plant phylogeny, chemical constituent specificity, traditional efficacy, chemical constituent measurability, and absorbed constituents. The primary Q-markers for Abelmoschi Corolla were anticipated to include quercetin-3'-O-β-D-glucopyranoside, gossypetin-8-O-β-D-glucuronide, isoquercetin, myricetin,quercetin, and hyperoside, with the aim of providing reference data for improving the quality evaluation system of Abelmoschi Corolla.
Abelmoschus/chemistry* ; Drugs, Chinese Herbal/pharmacology* ; Flowers/chemistry* ; Humans ; Animals ; Quality Control ; Flavonoids/chemistry*

BACKGROUND: It is inaccurate to reflect the level of dust exposure through working years. Furthermore, identifying a predictive indicator for lung function decline is significant for coal miners. The study aimed to explored whether club cell secretory protein (CC16) levels can reflect early lung function changes. METHODS: The cumulative respiratory dust exposure (CDE) levels of 1,461 coal miners were retrospectively assessed by constructed a job-exposure matrix to replace working years. Important factors affecting lung function and CC16 were selected by establishing random forest models. Subsequently, the potential of CC16 to reflect lung injury was explored from multiple perspectives. First, restricted cubic spline (RCS) models were used to compare the trends of changes in lung function indicators and plasma CC16 levels after dust exposure. Then mediating analysis was performed to investigate the role of CC16 in the association between dust exposure and lung function decline. Finally, the association between baseline CC16 levels and follow-up lung function was explored. RESULTS: The median CDE were 35.13 mg/m³-years. RCS models revealed a rapid decline in forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), and their percentages of predicted values when CDE exceeded 25 mg/m³-years. The dust exposure level (<5 mg/m³-years) causing significant changes in CC16 was much lower than the level (25 mg/m³-years) that caused changes in lung function indicators. CC16 mediated 11.1% to 26.0% of dust-related lung function decline. Additionally, workers with low baseline CC16 levels experienced greater reductions in lung function in the future. CONCLUSIONS CC16 levels are more sensitive than lung indicators in reflecting early lung function injury and plays mediating role in lung function decline induced by dust exposure. Low baseline CC16 levels predict poor future lung function.
Uteroglobin/blood* ; Humans ; Dust/analysis* ; Occupational Exposure/analysis* ; Male ; Middle Aged ; Adult ; Retrospective Studies ; Lung Injury/chemically induced* ; Coal Mining ; Biomarkers/blood* ; China/epidemiology* ; Air Pollutants, Occupational ; Female

Objective:To compare the prognostic values of different classification by using transpulmonary pressure gradient (TPG), diastolic pressure gradient (DPG) and pulmonary vascular resistance (PVR) in patients with pulmonary hypertension due to left heart disease (PH-LHD), and investigated hemodynamic and clinical factors associated with mortality in patients with PH-LHD.Methods:This was a single-center prospective cohort study. In-hospital patients diagnosed with PH-LHD via right heart catheterization at the Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, from September 2013 to December 2019 were enrolled. Patients were divided according to TPG (cutoff value 12 mmHg; 1 mmHg=0.133 kPa), DPG (cutoff value 7 mmHg), PVR (cutoff value 3 Wood Units), and the combination of TPG and PVR. Baseline characteristic was recorded. All patients were followed up until the occurrence of endpoint event, defined as all-cause death that occurred during the follow-up period, or until April 18, 2022. Receiver operating characteristic curves were used to compare the predictive value of 3 classification methods for all-cause death in PH-LHD patients. The optimal cutoff values were calculated using Jorden index. Survival analysis was performed using Kaplan-Meier analysis, and log-rank test was used to compare the predictive efficacy of classification methods based on optimal cutoff values or guidance-recommended thresholds for the survival of PH-LHD patients. Variables showing statistical significance in the univariate analysis were incorporated into multivariate Cox regression model to analyze the independent risk factors for all-cause mortality.Results:A total of 243 patients were enrolled, aged (54.9±12.7) years old, including 169 (69.5%) males. During a median follow-up of 57 months, there were 101 (41.6%) deaths occurred. Grouping results were as follows: (1) TPG: TPG≤12 mmHg group 115 patients, TPG>12 mmHg group 128 patients; (2) DPG: DPG<7 mmHg group 193 patients, DPG≥7 mmHg group 50 patients; (3) PVR: PVR≤3 Wood Units group 108 patients, PVR>3 Wood Units group 135 patients; (4) TPG and PVR: TPG≤12 mmHg and PVR≤3 Wood Units group 89 patients, TPG>12 mmHg and PVR>3 Wood Units group 109 patients. PVR ( AUC=0. 698,95% CI:0.631-0.766) had better predictive value for all-cause mortality than TPG ( AUC=0.596, 95% CI: 0.523-0.669) and DPG ( AUC=0.526, 95% CI: 0.452-0.601) (all P<0.05). The optimal cutoff values for TPG, DPG, and PVR were13.9 mmHg, 2.8 mmHg, and 3.8 Wood Units, respectively. Kaplan-Meier analysis based on the optimal cutoff values or guidance-recommended thresholds showed that PVR and TPG were the predictors of survival ( P<0.05), while DPG did not showed significance ( P>0.05). Multivariate Cox regression analysis showed that age, PVR and log 2N-terminal pro-B-type natriuretic peptide were independent risk factors for all-cause mortality in PH-LHD patients (all P<0.05). Conclusion:Classification according to PVR was most valuable in predicting all-cause death in PH-LHD patients, while TPG showed moderate predictive ability and DPG had no predictive value.

BACKGROUND:Muscle weakness is a common symptom after coronavirus disease 2019(COVID-19)infection and affects the ability to perform daily activities in humans during recovery.Low-frequency pulsed magnetic field stimulation at a strength of 1.5 mT and a frequency of 3 300 Hz can enhance the maximal voluntary contraction and strength endurance of human skeletal muscle by inducing and activating classical transient receptor potential channel 1(TRPC1),which produces a series of pathological support effects on muscle tissue.It has not been studied whether this means will improve muscle weakness in patients recovering from COVID-19. OBJECTIVE:To select the low-frequency pulsed magnetic field for magnetic stimulation of lower limb muscle groups in patients with COVID-19,in order to observe the effect of this stimulation on the improvement of muscle weakness of lower limb muscle groups in patients with COVID-19 during the recovery period. METHODS:Fourteen patients infected with COVID-19(Omicron strain)positive for Innovita COVID-19 Ab Test(Colloidal Gold)and accompanied by muscle weakness were recruited and randomly divided into two groups:a test group receiving magnetic field stimulation and a control group receiving sham treatment,respectively.The total duration of the trial was 3 weeks.The test group was given low-frequency pulsed magnetic stimulation of the lower limbs every 48 hours and the control group was given the same intervention procedure as the test group but with sham stimulation.Patients in both groups were not informed whether the magnetic stimulation apparatus was running or not.Nine sessions were performed in both groups and the changes in the maximum voluntary contraction,explosive leg force and strength endurance of the local muscle groups of the lower limbs were subsequently observed in both groups. RESULTS AND CONCLUSION:Among the eight local muscle groups collected,seven local muscle groups in the test group showed an increase in the maximum voluntary contraction value after 3 weeks of low-frequency pulsed magnetic field stimulation.In the control group,there were only three muscle groups with improvement in the maximum voluntary contraction.The rate of improvement in the anterior and posterior muscle groups of the left leg in the test group was significantly higher than that in the control group.The longitudinal jump height and peak angular velocity of the knee joint in both groups were improved compared with the pre-test measurement,and the elevation rate of jumping height in the test group was higher than that in the control group.Under the fatigue condition,the decline rates of peak angular velocity of the knee joint and jumping height in the test group decreased significantly,while those in the control group did not change significantly.The above data confirmed that the low-frequency pulsed magnetic field stimulation with the intensity of 1.5 mT and frequency of 3 300 Hz could improve the muscle strength of more local muscle groups in the lower limbs of patients with COVID-19 during the recovery period compared with the human self-healing process,and the whole-body coordination ability and functional status based on explosive leg force of the legs could be significantly improved.Therefore,low-frequency pulsed magnetic field stimulation can be used as an effective,non-exercise rehabilitation tool to improve muscle weakness in the lower limbs of patients with COVID-19.

The transgender children and adolescents(TCAs)face serious social dilemmas in the process of gender identity and expression,which hinders this group from seeking reasonable and equal rights to survival and development.From the perspective of equal rights and the theoretical framework of social dilemma,by interviewing TCAs who seek help from medical social workers in a hospital's multi-disciplinary transgender clinic,this paper revealed that under the traditional system of"binary gender",TCAs lacked social inclusiveness and infrastructure,which led to the two major social dilemmas of"social traps"and"social barriers"encountered by this group in the process of gender expression and gender identity.Specifically,the social gender selection of TCAs often leads to collective irrational reactions and gender punishment,preventing their legal and effective medical services.To this end,the research team used critical methodology to construct a joint disciplinary diagnosis and treatment path for TCAs with the participation of medical social workers,as well as verified that the path has significant intervention effects in rationalizing the needs of TCAs and their families,alleviating their psychological pressure and social adaptation problems in the process of gender identity,fostering a diverse dialogue environment in their families,as well as enhancing their self-efficacy and social participation,to provide assistahce to the TCAs groups in social difficulties,assisting their rights and interests be included in the child-friendly indicator system,and improving the whole society's tolerance and understanding for TCAs group.