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.

ObjectiveTo explore the construction of a machine learning model for the diagnosis of traditional Chinese medicine （TCM） syndromes in chronic cough and the optimization of this model using the Voting ensemble algorithm. MethodsA retrospective analysis was conducted using clinical data from 921 patients with chronic cough treated at the Respiratory Department of Dongfang Hospital， Beijing University of Chinese Medicine. After standardized processing， 84 clinical features were extracted to determine TCM syndrome types. A specialized dataset for TCM syndrome diagnosis in chronic cough was formed by selecting syndrome types with more than 50 cases. The synthetic minority over-sampling technique （SMOTE） was employed to balance the dataset. Four base models， logistic regression （LR）， decision tree （dt）， multilayer perceptron （MLP）， and Bagging， were constructed and integrated using a hard voting strategy to form a Voting ensemble model. Model performance was evaluated using accuracy， recall， precision， F1-score， receiver operating characteristic （ROC） curve， area under the curve （AUC）， and confusion matrix. ResultsAmong the 921 cases， six syndrome types had over 50 cases each， phlegm-heat obstructing the lung （294 cases）， wind pathogen latent in the lung （103 cases）， cold-phlegm obstructing the lung （102 cases）， damp-heat stagnating in the lung （64 cases）， lung yang deficiency （54 cases）， and phlegm-damp obstructing the lung （53 cases）， yielding a total of 670 cases in the specialized dataset. High-frequency symptoms among these patients included cough， expectoration， odor-induced cough， throat itchiness， itch-induced cough， and cough triggered by cold wind. Among the four base models， the MLP model showed the best diagnostic performance （test accuracy： 0.9104； AUC： 0.9828）. Compared with the base models， the Voting ensemble model achieved superior performance with an accuracy of 0.9289 on the training set and 0.9253 on the test set， showing a minimal overfitting gap of 0.0036. It also achieved the highest AUC （0.9836） in the test set， outperforming all base models. The model exhi-bited especially strong diagnostic performance for damp-heat stagnating in the lung （AUC： 0.9984） and wind pathogen latent in the lung （AUC： 0.9970）. ConclusionThe Voting ensemble algorithm effectively integrates the strengths of multiple machine learning models， resulting in an optimized diagnostic model for TCM syndromes in chronic cough with high accuracy and enhanced generalization ability.

ObjectiveTo study on the different therapeutic effects and potential mechanisms of Rhei Radix et Rhizoma（RH） before and after steaming with wine on constipation model mice. MethodsFifty-four male ICR mice were randomly divided into control group， model group， lactulose group（1.5 mg·kg^-1）， high， medium and low dose groups of RH and RH steaming with wine（PRH）（8， 4， 1 g·kg^-1）. Except for the control group， the constipation model was replicated by gavage of loperamide hydrochloride（6 mg·kg^-1） in the other groups. After 2 weeks of modeling， each administration group was gavaged with the corresponding dose of drug solution， and the control and model groups were given an equal volume of normal saline， 1 time/d for 2 consecutive weeks. After administration， the feces were collected for 16S rRNA sequencing， the levels of gastrin（GAS）， motilin（MTL）， interleukin-6（IL-6）， γ-interferon（IFN-γ） in the colonic tissue were detected by enzyme-linked immunosorbent assay（ELISA）， the histopathological changes of colon were observed by hematoxylin-eosin（HE） staining， flow cytometry was used to detect the proportion changes of CD4⁺， CD8⁺ and regulatory T cell（Treg） in peripheral blood. ResultsCompared with the control group， the model group showed significantly decrease in fecal number in 24 h， fecal quality and fecal water rate（P<0.01）， the colon was seen to have necrotic shedding of mucosal epithelium， localized intestinal glands in the lamina propria were degenerated， necrotic and atrophied， a few lymphocytes were seen to infiltrate in the necrotic area in a scattered manner， the contents of GAS and MTL， the proportions of CD4⁺， CD8⁺ and Treg were significantly reduced（P<0.01）， the contents of IL-6 and IFN-γ were significantly elevated（P<0.05， P<0.01）. Compared with the model group， the fecal number in 24 h， fecal quality and fecal water rate of high-dose groups of RH and PRH were significantly increased（P<0.05， P<0.01）， the pathological damage of the colon was alleviated to varying degrees， the contents of GAS， MTL， IL-6 and IFN-γ were significantly regressed（P<0.05， P<0.01）， and the proportions of CD4⁺ and CD8⁺ were significantly increased（P<0.01）， although the proportion of Treg showed an upward trend， there was no significant difference. In addition， the results of intestinal flora showed that the number of amplicon sequence variant（ASV） and Alpha diversity were decreased in the model group compared with the control group， and there was a significant difference in Beta diversity， with a decrease in the relative abundance of Lactobacillus and an increase in the relative abundances of Bacillus and Helicobacter. Compared with the model group， the ASV number and Alpha diversity were increased in the high-dose groups of RH and PRH， and there was a trend of regression of Beta diversity to the control group， the relative abundance of Lactobacillus increased， and the relative abundances of Bacillus and Helicobacter decreased. ConclusionRH and PRH can improve dysbacteriosis， promote immune system activation， inhibit the release of inflammatory factors for enhancing the gastrointestinal function， which may be one of the potential mechanisms of their therapeutic effect on constipation.

Objective To track and evaluate the implementation and application of the occupational health standard Radiation shielding requirements for radiotherapy room—Part 4: Radiotherapy room of ²⁵²Cf neutron afterloading (GBZ/T 201.4-2015) by radiation health technical service agencies, medical institutions, health supervision agencies, and radiotherapy facility design units, and to provide a scientific basis for the further revision and implementation of this standard. Methods Following the Guideline for health standards tracking evaluation (WS/T 536-2017) and the project implementation plan, relevant practitioners were randomly selected for a questionnaire survey. The survey primarily focused on their awareness, standard training, application, and revision suggestions of GBZ/T 201.4-2015. The results were summarized and analyzed. Results A total of 168 evaluation questionnaires were collected from relevant practitioners in 28 provinces. Only 31.6% of the respondents reported being “well familiar” or “ familiar” with the standard, 27.4% of the respondents believed that the standard was widely used, and 45.2% of the respondents believed that the standard could meet the needs of their work. Only 14.9% of the respondents had received relevant training on the standard, more than half of the respondents had not applied the standard within the past 10 years, and 45.2% of the respondents believed that the standard "needs to be revised". Conclusion Due to the small number of californium-252 neutron afterloading radiotherapy devices in operation on the market, the overall awareness of the standard is low, suggesting that relevant authorities need to strengthen training and publicity of the standard, and that certain sections of the standard need to be revised or merged.

Aim To dynamically characterize neuronal damage in the cortex and hippocampus of mice follow-ing acute cerebral ischemia/reperfusion(I/R).Meth-ods Male C57BL/6J mice weighing 25-28 g under-went middle cerebral artery occlusion using the fila-ment method,followed by 1 hour of reperfusion to es-tablish the acute cerebral I/R injury mouse model.The experiment comprised a sham surgery group,I/R-6 h group,I/R-24 h group,and I/R-72 h group.Longa neurological function score was used to assess the neu-rological function.Triphenyltetrazolium chloride(TTC)staining was conducted to detect cerebral in-farct volume.Hematoxylin and eosin(HE)staining was utilized to observe brain tissue pathological dam-age.Nissl staining was performed to evaluate neuronal damage.Immunofluorescence histochemistry staining was employed to assess the activation of astrocytes and microglia,as well as neuronal loss.Transmission elec-tron microscopy was used to examine mitochondrial damage in hippocampal neurons.Western blot analysis was conducted to detect the expression levels of mito-chondrial fission-fusion-related proteins p-Drp1/Drp1,Mff,Fis1,and OPA1.Results With prolonged cere-bral I/R time,neurological functional impairment,cerebral infarct volume,neuronal damage in the cortex and hippocampus,glial cell activation,neuronal loss,and mitochondrial damage gradually worsened in mice.The expression of mitochondrial fission-related proteins increased gradually,while the expression of mitochon-drial fusion-related proteins decreased gradually.Con-clusions Neuronal pathological damage,such as glial cell activation,neuronal loss,and mitochondrial dam-age,is gradually aggravated with prolonged cerebral I/R time,which may be associated with mitochondrial dynamics imbalance.

Aim To explore the core target,key com-ponents and mechanism of Tibetan medicine Rhodiola crenulata in improving cerebral microcirculation based on literature research,network pharmacology,molecu-lar docking and experimental verification.Methods The chemical components of Rhodiola were collected through literature and database,and the potential tar-gets of Rhodiola crenulata were predicted by reverse pharmacophore matching.The related targets of cere-bral microcirculation disorder were obtained and targets were mapping with Rhodiola crenulata.PPI network was constructed and the core targets were screened.The regulatory network of"herb-component-target-dis-ease"was constructed and key components were screened.GO and KEGG enrichment analysis were conducted,and a"Core target-Pathway-Biological Process"network was constructed.Finally,molecular docking validation was carried out,and RT-qPCR and Western blot were used for animal experiments to fur-ther confirm the results of network pharmacology analy-sis.Results A total of 76 active components of Rhodiola crenulata were obtained and corresponding to 285 targets.Altogether 1074 related targets related to cerebral microcirculation disorder were obtained.A-mong them,there were 97 common targets and the main core targets were 6.The key components were 6.The results of molecular docking showed that the bind-ing activity of three key components to the core target was greater than that of the core target protein and its original ligand.The result of RT-qPCR and Western blot demonstrated that Tibetan medicine Rhodiola cre-nulata could significantly reduce the expression of core target CASP3 and AKT1(P＜0.01).Conclusions Tibetan medicine Rhodiola crenulata can improve the cerebral microcirculation disorder through multi compo-nents,multi targets and multi pathways.This study provides an experimental basis for clinical application of Tibetan medicine Rhodiola crenulata to treat cerebral microcirculation disorder.

Objective:To compare the influence of dronedarone and amiodarone on the bleeding risk of patients with atrial fibrillation treated with rivaroxaban anticoagulation.Methods:Clinical data of 81 patients with atrial fibrillation treated with rivaroxaban anticoagulation at Xi'an International Medical Center Hospital from January 2020 to July 2023, including 36 patients treated with dronedarone and 45 patients treated with amiodarone, were retrospectively analyzed. The effects of dronedarone and amiodarone on the anticoagulation of rivaroxaban were compared using the incidence of bleeding events, thrombosis events, and adverse reactions as outcome measures.Results:The total bleeding in the dronedarone group [22.22% (8/36)] was significantly higher than that in the amiodarone group [6.67% (3/45)] ( χ2 = 4.12, P < 0.05). The total bleeding of conventional-dose rivaroxaban in the dronedarone group was 30.00% (6/20), while the total bleeding of low-dose rivaroxaban was 12.50% (2/16), with no statistical significance ( χ2 = 1.58, P > 0.05). No thrombotic events or adverse reactions to dronedarone or amiodarone were observed in all patients. Conclusion:Compared with amiodarone, dronedarone significantly increases the bleeding risk of rivaroxaban anticoagulation in patients with non-valvular atrial fibrillation, and reducing the dose of rivaroxaban in patients using dronedarone does not reduce the bleeding risk.

Objective To explore the current status of H.pylori infection in the natural population of Sanya City,analyze its influencing factors,and provide a reference basis for the prevention and control of H.pylori infection.Methods A total of 677 residents from four districts of Sanya City were selected by overall stratified random sampling method,and were subjected to urea 14C breath test and questionnaire survey to calculate the positive rate of H.pylori in the natural population and analyze the influencing factors of H.pylori infection.Results A total of 606 residents were included,and the number of H.pylori positive detections was 261,with a positive detection rate of 38.5％.Among them,different ethnicity,marital status,smoking,eating vegetables and fruits,and literacy level were associated with H.pylori infection(P＜0.05);gender,age,BMI,alcohol consumption,drinking water source,betel quid chewing,and the number of cohabitants were not significantly associated with H.pylori infection(P＞0.05).Family infection was an independent risk factor for H.pylori infection in the natural population of Sanya City,and Li ethnicity,frequent consumption of fruits and vegetables,and college and higher education level were independent protective factors for H.pylori infection in the natural population of Sanya City.Conclusion The rate of H.pylori infection in the natural population of Sanya City is lower than the national average.Consuming more fruits and vegetables and improving the awareness of hygiene protection are conducive to the prevention of H.pylori infection;and the promotion of the family and related members with the same examination and treatment is important to avoid aggregation of infection within the family.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective:To investigate the diagnostic value of computed tomography(CT)combined with TaqMan probe for cardiopulmonary injury of pediatric patients with mycoplasma pneumonia of different clinical features.Methods:The medical records of 80 pediatric patients with mycoplasma pneumonia admitted to Shijiazhuang Maternal and Child Health Care Hospital from March 2020 to March 2023 were collected,and they were divided into<1 year old group(29 cases),1-3 years old group(23 cases)and>3 years old group(28 cases).They also were divided into long disease course group(43 cases,the disease course>7 d)and short disease course group(37 cases,the disease course≤7 d).All of pediatric patients underwent CT combined with TaqMan probe method to detect the cardiopulmonary injury,and to analyze the incidences of cardiopulmonary injury in pediatric patients of different age groups and different disease course groups.The CT and TaqMan probe were adopted to detect the pleural effusion,myocardial thickness,cardiothoracic ratio and the expression level of mycoplasma nucleic acid,and receiver operating characteristic(ROC)curves were adopted to analyze the diagnostic value of CT and probe in detecting cardiopulmonary injury of patients with mycoplasma pneumonia.Results:CT imaging showed that typical pulmonary abnormalities were present in patients of 62.5%,with a diagnostic accuracy of 93.75%(75/80),which main findings were pulmonary ground glass nodules(GGO),combined bacterial pneumonia and reticulation.Bronchiectasis was found in a small portion of patients.Bilateral pulmonary involvement was found in patients with pulmonary abnormalities,and the involvement of lower lobe was the most obvious in them.The 38 pediatric patients with clinically suspected incidental pulmonary embolism(PE)received additional CT examination with contrast agent,and the 24 pediatric patients of them were diagnosed as PE,and the diagnostic accuracy was 63.15%(24/38).TaqMan probe method was adopted to detect mycoplasma infection,and a high sensitivity and wide dynamic range detection system was established,which could conduct six times of dilutions for 10-fold between 0.2-0.2×10-5.Preparation was performed in 1 ng/μ l microbial community(MMC)-DNA standards,which had high linear dynamic range of 6 times of log10 dilutions with regression coefficient of R2=1.The detection lower limit was found to be 2×10-15 g/μl DNA.The incidence of cardiopulmonary injury gradually decreased with increasing age of pediatric patients with mycoplasma pneumonia of different ages.The incidences of cardiopulmonary injury in pediatric patients with mycoplasma pneumonia of<1 year old group,1 to 3 years old group and>3 years old group were respectively 93.10%,73.91%and 21.43%,and there were significant differences among the 3 groups(x2=7.660,33.019,P<0.05).The incidence(93.02%)of cardiopulmonary injury of long disease course group was significantly higher than that of short disease course group(27.03%),and the differences were statistically significant(x2=12.070,36.960,P<0.05),respectively.The amount of pleural effusion in the cardiopulmonary injury group was significantly higher than that in the non-cardiopulmonary damage group,and the myocardial thickness of cardiopulmonary injury group was significantly increased at the same time,and the cardiothoracic ratio of cardiopulmonary injury group was also significantly higher than that of non-cardiopulmonary injury group.There was significant difference in the expression level of mycoplasma nucleic acid(t=9.52,3.33,4.22,10.00,P<0.05).ROC curve analysis showed that the AUC value of CT combined with TaqMan probe method was larger than 0.5 in diagnosing cardiopulmonary injury of pediatric patients with mycoplasma pneumonia of different clinical features,and the AUC value of the combined diagnosis was largest.Conclusion:CT combined with TaqMan probe method has higher diagnostic value for the cardiopulmonary injury of pediatric patients with mycoplasma pneumonia.It should be considered to conduct the diagnosis of cardiopulmonary injury for pediatric patients who persistently exist the clinical symptom of mycoplasma pneumonia.The adaptation of existing TaqMan probe method,and the further expanded dPCR detection combination would improve the microbial diagnostic toolbox,which would provide reliable quantitative data for treatment decisions to cardiopulmonary injury of pediatric patients with mycoplasma pneumonia.