ObjectiveTo establish a reliable chronic obstructive pulmonary disease (COPD) mouse model based on a self-developed multichannel automatic control system for long-term continuous cigarette smoke exposure in small animals using a novel continuous cigarette smoke exposure method, and to conduct phenotypic evaluation and analysis, thereby providing an animal experimental basis for investigating COPD pathogenesis and prevention strategies. MethodsTwenty male C57BL/6J mice aged 6 weeks were randomly and equally divided into a control group and a model group. The model group (n=10) underwent 6 h of continuous cigarette smoke exposure daily (6 cigarettes per day for 12 consecutive weeks), while the control group (n=10) received no intervention. Body weight was monitored biweekly. Post-exposure, in vivo micro-CT imaging was performed. After euthanasia, serum and bronchoalveolar lavage fluid (BALF) levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were quantified by ELISA. Lung tissues underwent H&E and Masson's trichrome staining to observe changes in lung morphology and inflammatory cell infiltration, and the mean linear intercept (MLI) was calculated, thereby comprehensively evaluating the clinical features of COPD in the mouse model. ResultsCompared with the control group, the model group showed significantly reduced body weight (P<0.01) from the fourth week. Compared with the control group, IL-6 level in the serum and BALF of the model group increased by 27.2% and 140.0%, respectively (P<0.01). TNF-α level in the serum and bronchoalveolar lavage fluid of the model group increased by 16.7% (P<0.01) and 19.3% (P<0.05), respectively. Histopathological examination revealed alveolar wall thinning, septal rupture, emphysematous bullae formation, reduced alveolar count, bronchial wall thickening with lumen narrowing, and inflammatory cell infiltration. MLI was significantly elevated (P<0.01). Masson's staining confirmed collagen deposition and bronchial remodeling. Micro-CT demonstrated localized high-density shadows exhibiting typical features of chronic bronchitis. Conclusion The self-developed device enables long-term continuous smoke exposure, and the successfully established COPD mouse model exhibits pathological features highly consistent with clinical manifestations, offering an efficient and reliable tool for COPD research.

Space medicine,as a comprehensive discipline ensuring the safety,health,and efficient performance of astronauts during manned space missions,focuses on elucidating the underlying mechanisms of multi-system physiological effects induced by extreme space environments and developing corresponding protective strategies.With China's space program transitioning into an application and development phase,space medical experiments—a critical domain within space applications—face significant opportunities and challenges.This paper reviews the international development trend in the field of medical experiments and the progress in China from perspectives including platform system construction,utilization of novel technologies,and scientific discoveries.It further outlines the engineering framework,guiding ideology,and key research directions for space medical experiments under China's Space Station Application and Development Project.Deliberations and prospects center on the in-depth analysis of the adaptation law of life in space flight,the application of big data and artificial intelligence technology,the emerging challenges it faces,and the scientific research organization models.This work aims to provide a reference for the development of space medical experiment field in China.

ObjectiveTo evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) for muscle atrophy in patients with immobilization after surgical fixation of foot and ankle fractures.MethodsThis was a two-arm randomized controlled trial wherein 80 patients were recruited and divided into control (n = 40) and intervention (n = 40) groups. The control group received conventional orthopedic treatment, whereas the intervention group received TEAS and conventional treatment. The intervention group received TEAS 3 times a week for 30 min each time for 8 weeks. The primary outcomes were muscle thickness (MT) and cross-sectional area (CSA) of the rectus femoris and gastrocnemius muscles, whereas the secondary outcome measure was echo intensity (EI). Data were collected before the fixation operations (baseline assessment) and 4 and 8 weeks after intervention.ResultsCompared with baseline, the MT and CSA were reduced in both groups by the end of treatment, whereas EI increased in both groups. At week 4, the reduction in the rectus femoris CSA in the intervention group was significantly lower than that in the control group (P = .02); however, the between-group differences in the MT and EI (all P .05) were not significant. No serious adverse events were observed in either group.ConclusionOur study showed that TEAS can improve muscle atrophy by attenuating the decline in the muscle CSA. Because this was only a pilot trial, subsequent studies will need longer follow-ups and larger sample sizes.

Objective To investigate the multi spiral computed tomography(MSCT)characteristics of intraductal papillary neo-plasm of the bile duct(IPNB)and to distinguish the benign and malignant ones.Methods The MSCT and clinical data of 23 patients with IPNB confirmed by pathology were analyzed retrospectively.According to the pathology,they were divided into benign and malignant groups,including 12 cases of benign group(7 cases with low to medium grade intraepithelial neoplasia,and other 5 cases with high grade intraepithelial neoplasia)and 11 cases of malignant group with invasive carcinoma.All patients underwent plain and tri-phasic enhanced CT scans of upper abdomen.The enhanced scan included arterial phase,portal phase and delayed phase.The location,size,growth mode,enhancement type,invasion and metastasis,bile duct manifestations and bile duct stones were analyzed.Independent sample t-test was used to count the transverse diameter,longitudinal diameter and aspect ratio of tumor.Chi square test was used to compare the difference in other parameters between benign and malignant groups.Results There were no significant differences between benign and malignant IPNB groups in the location of the disease,the transverse diameter of the tumor,the dilatation of the bile duct and the presence of the stones(P>0.05).However,the significant differences in tumor growth mode,tumor longitudinal diameter and aspect ratio,enhancement type,invasion of bile duct wall and bile duct truncation were found(P<0.05).Conclusion Benign IPNB is common,while the IPNB with diffuse growth,progressive enhancement,invasion of bile duct wall and extrabiliary structures,and distant metastasis may indicate malignance,and the final diagnosis depends on the pathology.

BackgroundSleep disorder can adversely affect human physical and mental health， with important implications for socioeconomic development. And higher vocational college students are subject to various pressures and stimuli exerted by academic studies， job seeking and family socioeconomic status， which may contribute to the onset insomnia symptom or sleep disorder. ObjectiveTo discuss the sleep status and influencing factors among higher vocational college students， and to provide references for improving their sleep status. MethodsIn January and February， 2022， a stratified random sampling method was utilized to enroll 3 300 students from five higher vocational colleges in Wenjiang district of Chengdu city. All the participants were assessed using Insomnia Severity Index （ISI）， Patient Health Questionnaire Depression Scale-9 item （PHQ-9） and Generalized Anxiety Disorder Scale-7 （GAD-7）. Pearson correlation analysis was conducted to test the correlation of ISI with PHQ-9 and GAD-7 scores， and the Logistic regression analysis was performed to identify the influencing factors of insomnia symptom in higher vocational college students. ResultInsomnia symptom was detected in 81.90% （2 497 / 3 300） of higher vocational college students. The detection rate of insomnia symptom among vocational college students yielded statistical difference in terms of gender， family socioeconomic status， being an only child or having siblings， degree of psychological pressure exerted by academic studies or job seeking， amount of hours spent on Internet per day， frequency of physical exercise， and the presence or absence of anxiety symptom and depression symptom （χ²=21.032， 22.172， 8.983， 75.939， 36.781， 32.350， 54.512， 86.561， P<0.01 or 0.05）. Among higher vocational college students， ISI score was positively correlated with GAD-7 and PHQ-9 scores （r=0.620， 0.714， P<0.01）， and GAD-7 score was positively correlated with PHQ-9 score （r=0.824， P<0.01）. Gender， family socioeconomic status， degree of psychological pressure exerted by academic studies or job seeking， amount of hours spent on Internet per day， frequency of physical exercise， and the presence or absence of anxiety symptom and depression symptom were effective factors in predicting the insomnia symptom in higher vocational college students （P<0.01 or 0.05）. ConclusionFemale gender， average and below average family socioeconomic status， moderate-to-severe degree of psychological pressure exerted by academic studies or job seeking， spending 2~5 h， 5~7 h or >7 h on Internet per day， inadequate physical exercise and presence of depressive symptom are the risk factors for insomnia symptom in higher vocational college students.［Funded by Sichuan Provincial Primary Health Development Research Center in 2022， North Sichuan Medical College （number， SWFZ22-C-89）］

OBJECTIVE: To investigate the high risk factors of failure of autologous arteriovenous fistula (AVF) in hemodialysis patients. METHODS: A retrospective study was conducted, patients with maintenance hemodialysis (MHD) undergoing AVF admitted to General Hospital of Western Theater Command from January 2021 to December 2022 were enrolled, including 107 patients with normal AVF and 168 patients with AVF dysfanction. According to the causes of AVF failure, the patients were divided into AVF stenosis group (n = 103) and AVF thrombosis group (n = 65). Age, gender, body mass index (BMI) and comorbidities (hypertension, diabetes, coronary heart disease) and other clinical data of all patients were collected. Hemoglobin, hematocrit, white blood cell count, neutrophil count, lymphocyte count, platelet count, C-reactive protein (CRP), high density lipoprotein, low density lipoprotein, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) within 1 month of AVF use in normal dialysis patients and 1 week before AVF failure. Multivariate Logistic regression was used to analyze the independent risk factors of AVF dysfuction in MHD patients. The receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of risk factors on AVF dysfuction in MHD patients. RESULTS: (1) There were significant differences in age, BMI, hypertension, hemoglobin, hematocrit, PLR and CRP [age (years): 56.94±14.32, 58.83±14.05, 51.57±13.19; BMI (kg/m²): 22.83±3.10, 21.27±4.98, 23.35±2.72; hypertension: 93.20%, 64.62%, 86.92%; hemoglobin (g/L): 110.82±22.16, 88.70±24.00, 87.95±23.45; hematocrit: 0.350±0.069, 0.282±0.076, 0.275±0.071; PLR: 197.35±113.59, 192.55±138.25, 162.12±73.25; CRP (mg/L): 10.01±4.02, 8.18±5.42, 3.17±1.30, all P < 0.05], among AVF stenosis group, AVF thrombosis group and AVF normal group, there were statistically significant differences no statistically significant difference was found in other indexes among three groups. (2) Multivariate Logistic regression analysis showed that hypertension [odds ratio (OR) = 4.849, 95% confidence interval (95%CI) was 1.278-18.397, P = 0.020], elevated CRP levels (OR = 2.104, 95%CI was 1.533-2.888, P = 0.000) were associated with AVF stenosis. Elevated CRP levels (OR = 1.984, 95%CI was 1.442-2.730, P = 0.000) was an independent risk factor for AVF thrombosis. Analysis of ROC curve showed that the area under the curve (AUC) of AVF dysfunction predicted by CRP was 0.712, 95%CI was 0.637-0.786, P = 0.000; CRP cut-off value was 1.8 mg/L, the sensitivity was 67.0%, the specificity was 83.7%. CONCLUSIONS Elevated CRP is an independent risk factor for AVF failure in hemodialysis patients, which can be used to predict the occurrence of AVF failure.
Humans ; Retrospective Studies ; Constriction, Pathologic ; Renal Dialysis/adverse effects* ; Lymphocytes ; C-Reactive Protein ; Risk Factors ; Hypertension ; Hemoglobins ; Thrombosis ; ROC Curve ; Prognosis

Objective:To report a SPTLC2 gene mutation in a family with a phenotype of Charcot-Marie-Tooth disease.Methods:To screen the family of patients with pathogenic mutations of SPTLC2 gene from the database of hereditary peripheral neuropathy in the Department of Neurology, Peking University First Hospital, and to collect their clinical data, peripheral nerve conduction examination, nerve ultrasound examination, pathological examination of the peroneal nerve and whole exome sequencing results of prohand.Results:One family was screened, the proband was a 16-year-old female with 4 years of sensory loss and anhidrosis of both lower limbs and 16 months of walking difficulty who admitted to Peking University First Hospital in January 2022. Physical examination showed sensory loss, dry skin and weakness in distal limbs. Her father had numbness and dry skin in the distal lower limbs from childhood,weakness and atrophy of his lower limbs in adulthood. He died at age of 52 years old. The nerve conduction study revealed no action potentials of the sensory and motor nerves of the lower limbs in the proband. The amplitude of the compound muscle action potential of the motor conduction of the bilateral ulnar nerve and median nerve decreased, and the nerve conduction velocity of the bilateral median nerve were 32 m/s and 24 m/s. Neurosonography showed thickening of peripheral nerves. Sural biopsy revealed severe loss of myelinated and unmyelinated nerve fibers with onion bulbs formation. SPTLC2 gene showed a known heterozygous p.G435V mutation. The lower limb weakness was improved after oral L-serine.Conclusions:SPTLC2 gene mutation can lead to an intermediate Charcot-Marie-Tooth disease phenotype. L-serine can improve the limb weakness.

Objective:To explore the value of different radiomics models based on machine learning in predicting the risk of distant recurrence and metastasis of triple-negative breast cancer after neoadjuvant therapy.Methods:The clinical and imaging data of 150 patients with triple-negative breast cancer (TNBC) confirmed by histopathology were retrospectively analyzed. All patients underwent neoadjuvant chemotherapy and surgical resection from August 2011 to May 2017 in Fudan University Shanghai Cancer Center and Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. One hundred and nine patients from Shanghai Fudan University Shanghai Cancer Center were used as the training group, and 41 patients from Ruijin Hospital, Shanghai Jiao Tong University School of Medicine were used as the validation group. The features were extracted from dynamic contrast-enhanced MRI (DCE-MRI) before treatment and were added with time domain features innovatively. Least absolute shrinkage and selection operator cross validation and recursive feature elimination were applied to select features. Six different supervised machine learning algorithms (logistic regression, linear discriminant analysis, k-nearest neighbor, naive bayesian, decision tree, support vector machine) were used to predict the prognosis. ROC curve, accuracy and F1 measure were used to evaluate the performance of the six algorithms, and also verified by the validation group.Results:The support vector machine algorithm had the best predictive effect in the recurrence and metastasis model based on 15 features, with the highest area under curve (training group was 0.917, validation group was 0.859), and the highest accuracy rate (training group was 87.5%, validation group was 82.9%) and the highest F1 measure (training group was 0.800, validation group was 0.741). In addition, of the 15 imaging features, 12 were the time domain features and 3 were spatial features.Conclusion:With the help of the time domain features and machine learning algorithms, radiomics signatures based on preoperative DCE-MRI can help predict the distant prognosis for TNBC after neoadjuvant chemotherapy and provide support for clinical decision making and follow-up management.

Objective:To explore the evaluation of transesophageal echocardiography(TEE) in patients with massive regurgitation of posterior mitral valve prolapse undergoing transapical off-pump NeoChord repair.Methods:Eight patients from April to July 2019 in the Second Affilliated Hospital of Zhejiang Univerity with massive regurgitation of posterior mitral valve prolapse underwent NeoChord repair mitral valve morphology, prolapse position and regurgitation degree were evaluated before NeoChord implantation by TEE. Under TEE guidance, the puncture site was identificated, the position and length of artificial chordae were adjusted during implantation. NeoChord′s function and positon after implantation were observed. The complications were monitored during the operation.Results:Mitral valve repair by NeoChord system was successfully performed with implantation of 2 to 4 artificial chordaes in eight patients respectively. Intraoperative TEE and pre-discharge transthoracic echocardiography(TTE) showed moderate MR in two patients, mild to moderate MR in one patient, mild MR in the remaining five patients. Reexaminations with TTE at 1 month after operation showed moderate MR in six patients, and mild to moderate MR in two patients. And no postoperative complications were noted.Conclusions:NeoChord system is a safe, effective and feasible treatment method for patient with mitral valve prolapse, TEE plays an important role during NeoChord implantation.

The outbreak of coronavirus disease (COVID-19) caused by SARS-CoV-2 virus continually lead to worldwide human infections and deaths. Currently, there is no specific viral protein-targeted therapeutics. Viral nucleocapsid protein is a potential antiviral drug target, serving multiple critical functions during the viral life cycle. However, the structural information of SARS-CoV-2 nucleocapsid protein remains unclear. Herein, we have determined the 2.7 Å crystal structure of the N-terminal RNA binding domain of SARS-CoV-2 nucleocapsid protein. Although the overall structure is similar as other reported coronavirus nucleocapsid protein N-terminal domain, the surface electrostatic potential characteristics between them are distinct. Further comparison with mild virus type HCoV-OC43 equivalent domain demonstrates a unique potential RNA binding pocket alongside the -sheet core. Complemented by binding studies, our data provide several atomic resolution features of SARS-CoV-2 nucleocapsid protein N-terminal domain, guiding the design of novel antiviral agents specific targeting to SARS-CoV-2.