Abstract In order to understand and analyze the current standards and application of school desks and chairs for primary and secondary schools, and to promote the healthy growth of primary and secondary school students. The article conducts a comprehensive review of the functional and dimensional standards for school furniture both domestically and internationally, and objectively analyzes the current utilization and existing issues concerning desks and chairs in schools. It further explores the multifaceted factors that influence the allocation of desks and chairs, and proposes effective countermeasures, so as to provide a reference for the risk factors of common diseases related to desks and chairs, such as myopia and abnormal spinal curvature.

Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans ; Dental Cementum/injuries* ; Consensus ; Diagnosis, Differential ; Cone-Beam Computed Tomography ; Tooth Fractures/therapy*

AIM:To investigate the therapeutic effect of menstrual blood-derived endometrial stem cells(MenSCs)on chemotherapy-induced intestinal mucositis and flora disorders in mice,and to explore the potential mecha-nism.METHODS:The mice were randomly divided into 3 groups including normal treatment,cisplatin(Cis)treatment and Cis+MenSC treatment,with 10 mice in each group.To induce intestinal mucositis,the mice were treated with Cis(2 mg·kg-1·d-1)by intraperitoneal injection for 5 consecutive days.Control mice for normal group were received equal vol-umes of normal saline.For Cis+MenSC treatment,MenSCs(1×106)was transplanted into the mice of Cis treated mice through tail vein.The performances and weight changes of mice were examined during the experiment.After the treat-ment,the small intestine and colon were isolated for subsequent HE staining,the ratio of F4/80 and IL-6 positive cells in small intestine were detected by immunohistochemical staining,and the expression of tight junction,inflammation and apoptosis related proteins was detected by Western blot.16S rDNA amplicon sequencing was performed to detect the diver-sity and richness of intestinal flora in mice.RESULTS:Compared to the Cis group,the MenSCs-treated mice showed sig-nificantly increased body weight,relieved intestinal lymphocytes infiltration,alleviated intestinal villous edema,and or-derly arranged glands in intestinal tissues.Further analysis indicated that MenSCs transplantation significantly up-regulat-ed the expression of intestinal tight junction related proteins ZO-1 and occludin in Cis-treated mice(P＜0.05).Subse-quently,MenSCs transplantation significantly inhibited the macrophages infiltration in intestinal tissues(P＜0.01),down-regulated the expression of pro-inflammatory factors IL-1 and IL-6 and pro-apoptotic protein Bax(P＜0.01),while up-regu-lated anti-inflammatory factor IL-10 and anti-apoptotic protein Bcl-2(P＜0.01).Additionally,further microflora sequenc-ing indicated that MenSCs transplantation prevented mice from Cis-induced intestinal flora disorder,and significantly re-duced the abundance of harmful bacteria such as isenbergiella tayi and Anaerotruncus colihominis(P＜0.01).At the same time,the abundance of beneficial bacteria Lactobacillus apodemi was increased(P＜0.05),thereby restoring the composi-tion and function of healthy intestinal flora.CONCLUSION:MenSCs transplantation alleviates the chemotherapy-in-duced damage of intestinal structure,relieves the symptoms of chemotherapy-induced mucositis and restores the homeosta-sis of intestinal flora in mice.

ObjectiveTo explore the effect of precocious puberty on glucose metabolism and lipid metabolism in female rats. MethodsSixty two-day-old female rats were randomly divided into 2 groups. When aged 5 days， the precocious puberty group and normal group were given a single subcutaneous injection of danazol and solvent soybean oil respectively. The vaginal opening of rats was monitored from their 21 days of age. After 12 hours of fasting， all successful modeling rats were randomly executed within 3 days after vaginal opening， when aged 7 and 12 weeks. Then we measured the rats’ body weight and length， determined the concentrations of glucose， insulin， blood lipids， estradiol， leptin and adiponectin with enzyme-linked immunosorbent assay and observed the pathological changes of perirenal fat， uterus and ovary. ResultsFor body weight and length， rats in the precocious puberty group were smaller than those in the normal group within 3 days after vaginal opening， but which did not affect their subsequent growth and development， and there was no significant difference between the two groups at 7 and 12 weeks of age. Within 3 days after vaginal opening， insulin levels had significant difference between the two groups （P = 0.001）， the precocious group showed hyperinsulinemia and increased number of perirenal adipocytes. At three execution times， no significant difference was noted in estradiol， leptin and adiponectin levels between the two groups. The same was true in the ratios of ovary or uterus to body weight between the two groups. ConclusionsPrecocious puberty makes earlier onset of pubertal development and allows body maladaptation to the sudden changes of the internal environment. However， the changes due to precocious puberty are temporary and reversible， and they may become normal in adulthood.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Objective To compare the effect of routine speech training and computer-assisted training on post-stroke dysarthria. Methods From March,2021 to April,2023,72 patients with post-stroke dysarthria in Beijing Bo'ai Hospital were ran-domly divided into control group(n=36)and experimental group(n=36).Both groups received routine rehabili-tation,while the control group received routine speech training,and the experimental group received computer-assisted training,for four weeks.They were assessed with modified Frenchay Dysarthria Assessment(m-FDA)and Speech Intelligibility(SI)before and after intervention. Results Eight cases in the control group and one case in the experimental group dropped down.The scores of m-FDA and SI improved in both groups after treatment(|Z|＞4.183,P＜0.001),and there was no significant difference between two groups(|Z|＜1.598,P＞0.05).Noninferiority of m-FDA was found between two groups(|t|＞3.656,P＜0.001). Conclusion Computer-assisted training could improve the speech function of patients with post-stroke dysarthria,simi-lar to routine speech training.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.

Objective:To investigate the risk factors of pathological complete response(pCR)after neoadjuvant therapy for locally advanced gastric cancer(LAGC)and assess the value of gastric tumor markers for predicting pCR in LAGC patients.Methods:We retrospectively ana-lyzed the clinical and pathological characteristics of 213 patients who underwent radical gastrectomy and gastric tumor marker analysis after neoadjuvant therapy at The Chinse PLA General Hospital First Medical Center,between January 2020 and April 2024(20 and 193 cases in the pCR and non-pCR groups,respectively).The interrelationships among pCR,tumor markers,and clinicopathological features were compared,and independent risk factors for pCR were analyzed.A nomogram was constructed to predict the pCR.Results:Among 213 patients,20(9.4% )achieved pCR.Univariate analysis showed that age(P=0.067),tumor bed diameter(P<0.001),gastrin-17 levels(P=0.005),CA72-4 levels(P=0.073),pepsinogen ratio(P=0.024),and neoadjuvant immunotherapy(P=0.022)were strongly associated with pCR in LAGC pa-tients.Multivariate analysis showed that neoadjuvant immunotherapy,CA72-4 levels<2.5 U/mL,gastrin-17 levels<1.48 pmol/L,and tumor bed diameter<2.85 cm were independent predictive factors for pCR in LAGC patients(P<0.05).These indicators were incorporated into a nomogram prediction model;an receiver operating characteristic curve(ROC)was plotted with an AUC(95% CI)of 0.863(0.785-0.942).The calibration and decision curves suggested that the nomogram was well calibrated and had a good net benefit.Conclusions:Gastric tumor markers can effectively predict pCR after neoadjuvant therapy in LAGC patients.Our nomogram showed a good predictive ability for pCR.Thus,our findings can serve as a useful reference for clinical decision making for LAGC patients.

Objective To summarize the clinical experience of pulmonary lobectomy by uniportal video-assisted thoracoscope in parallel position.Methods The clinical data of 90 patients who underwent uniportal video-assisted thoracoscopic lobectomy in Zhongshan Hospital(Xiamen Branch),Fudan University were retrospectively analyzed.Among them,41 patients underwent lobectomy by uniportal thoracoscope in parallel position,and 49 patients underwent lobectomy by uniportal thoracoscope in non-parallel position.The perioperative related indicators of the two groups were compared.Results There was no significant statistical difference between the parallel uniportal thoracoscopic group and the non-parallel uniportal thoracoscopic group in terms of operation time[(135.2±18.1)min vs.(132.7±25.6)min],intraoperative blood loss[(100.1±27.2)mL vs.(117.3±33.5)mL],postperative extubation time[(3.0±0.7)d vs.(3.1±0.9)d],hospitalization time after operation[(4.3±1.3)d vs.(4.8±1.5)d]and relapse rate after surgery in 3 year(7.32%vs.10.20%).Conclusion Lobectomy by uniportal thoracoscope in parallel position was safe and feasible in technique.