Objective: To evaluate the classroom environmental management and CO 2 volume concentration in primary and secondary schools from Liaoning, Tianjin, and Shanghai, thereby providing a scientific basis for developing targeted strategies to improve classroom air quality. Methods: From December 16 to 26, 2024, by using stratified random cluster sampling method, the questionnaire survey was conducted in 72 primary and secondary schools (24 each of primary, junior high, and regular high schools) across Liaoning, Tianjin and Shanghai. Information on heating, ventilation and other classroom environmental management was collected. Additionally, 108 classrooms were selected for on site microclimate measurements, including temperature, humidity, wind speed and CO 2 volume concentration. Univariate analysis and multiple linear regression models were employed to explore related factors of classroom CO 2 volume concentration. Results: Among the three provinces/municipalities, 20.8% of schools regularly monitored the microclimate. The overall compliance rate for classroom CO 2 volume concentration was 17.6%. Multiple linear regression analysis showed that CO 2 volume concentration in regular and junior high school classrooms were higher than in primary school classrooms ( β=0.067, 0.046, 95%CI =0.036-0.099, 0.013-0.080); classrooms ventilated regularly in the morning and afternoon had higher CO 2 volume concentration than those ventilated during every break between classes ( β=0.043, 95%CI = 0.007- 0.080); both temperature ( β=0.010, 95%CI =0.004-0.016) and humidity ( β=0.003, 95%CI =0.002-0.004) were positively correlated with CO 2 volume concentration (all P <0.05). Conclusions Excessive CO 2 volume concentration in primary and secondary school classrooms is a prominent issue, and ventilation frequency is a key intervenable factor for controlling CO 2 levels. It is recommended to promote ventilation during every break between classes as a core management measure and to emphasize air quality supervision in regular high school classrooms.

Abstract The study examines the development and application of microclimate standards for primary and secondary school classrooms, so as to ensure and promote the healthy growth of primary and secondary school students. The paper systematically reviews relevant domestic and international standards, analyzes the problems and shortcomings arising from their practical application and proposes effective countermeasures, in order to provide robust references aimed at optimizing the classroom environment in primary and secondary schools for student health, as well as offering practical support to advance the construction of a healthy China.

Objective To identify key influencing factors for comorbidity between myopia and depressive symptoms among middle school students, and to construct a nomogram predictive model capable of quantitatively assessing their comorbidity risk. Methods A total of 13 976 middle school students aged 11-20 from 14 counties (cities, districts) in Yichang City were selected as study subjects through cluster random sampling. On-site surveys were conducted using the Student Health Status and Influencing Factors Questionnaire and the Depression Assessment Scale. Chi-square test and multivariate logistic regression analysis were employed to investigate the comorbidity association between myopia and depressive symptoms and their influencing factors, and to construct a nomogram model for risk prediction. Results The myopia screening rate among middle school students was 68.67%, the depression detection rate was 23.31%, and the comorbidity detection rate was 16.59%. Logistic regression analysis revealed that boarding school (OR=1.207), smoking history (OR=1.504), alcohol consumption (OR=2.016), outdoor activity time <1 h (OR=1.293), internet addiction (OR=4.008), school bullying (OR=4.358), school absence due to illness within one year (OR=1.712), and severe injury within one year (OR=1.356) were risk factors for myopia-depression comorbidity. Protective factors included male gender (OR=0.578), junior high school students (OR=0.670), nuclear family (OR=0.862), moderate-to-high intensity exercise ≥1 h/d (OR=0.852), screen time <2h (OR=0.803), adequate sleep duration (OR=0.602), and homework time after school <2 h/d (OR=0.766). The nomogram model constructed based on the above variables exhibited excellent discriminant power (AUC = 0.712) and calibration (Hosmer-Lemeshow test, χ²=3.245, P> 0.05). Conclusion Factors such as boarding school attendance, smoking history, alcohol consumption, less than 1 hour of daily outdoor activity, internet addiction, and school bullying are significantly associated with the comorbidity of screening myopia and depressive symptoms among middle school students in Yichang City. The nomogram model effectively predicts the comorbidity risk in this population, facilitating timely intervention for high-risk individuals.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:To investigate the relationship between sarcopenic obesity(SO), defined by various obesity indicators, and mortality risk in older adults based on a prospective cohort from multiple nursing homes.Methods:Sarcopenia was diagnosed according to the 2019 consensus of the Asian Working Group for Sarcopenia.Obesity was defined using six different indicators: waist circumference(WC), waist-hip ratio(WHR), waist-height ratio(WHTR), body mass index(BMI), visceral fat area(VFA), and percentage of body fat(PBF).A prospective cohort of adults aged 60 and above was established across 15 nursing homes in Zigong City, with annual follow-ups on survival status conducted over two consecutive years.Cox proportional hazards regression models were employed to analyze the association between SO, defined by different obesity indicators, and mortality risk, calculating hazard ratios( HR)and their 95% confidence intervals( CI). Results:A total of 695 older adults were included in the study, of whom 67.1% were male.During the 2-year follow-up period, 88 participants died.The prevalence of SO as defined by WC, WHR, WHTR, BMI, VFA, PBF was found to be 17.6%, 30.1%, 48.9%, 3.0%, 28.3%, and 58.7%, respectively.When SO was defined using WC, WHR, WHTR, BMI, and VFA, there was no statistically significant difference in mortality rates between the SO and non-SO groups.However, when defined by PBF, the SO group exhibited a significantly higher mortality rate compared to the non-SO group(16.9% vs.6.6%, P<0.01).Cox proportional hazards regression analysis revealed that, compared to the non-SO group, the SO group defined by PBF had a significantly increased mortality risk( HR=2.81, 95% CI: 1.67-4.73, P<0.001).After adjusting for potential confounding factors, the mortality risk for the SO group remained significantly higher than that of the non-SO group( HR=1.97, 95% CI: 1.14-3.38, P=0.015). Conclusions:The prevalence of SO varies significantly across different obesity indicators.SO defined by PBF is significantly associated with mortality risk in nursing home residents.This study provides new evidence for further optimizing the diagnostic criteria for SO in this population.

Objective:To construct a predictive model for mortality in patients with multiple trauma combined with thoracic injuries and evaluate its predictive value.Methods:A retrospective cohort study was conducted to analyze the clinical data of 184 patients with multiple trauma combined with thoracic injuries admitted to the International Zhuang Medicine Hospital Affiliated to Guangxi University of Chinese Medicine from April 2019 to December 2023, including 129 males and 55 females, aged 19-85 years [(46.1±13.7)years]. According to the prognostic outcomes at 3-month follow-up after discharge, the patients were divided into survival group ( n=145) and death group ( n=39). Data were recorded in both groups at admission, including gender, age, and cause of injury, laboratory tests such as systolic blood pressure, oxygen saturation (SaO 2), hemoglobin (Hb), neutrophil-to-lymphocyte ratio (NLR), and lactate, combined injuries such as the number of combined injuries, number of rib fracture, bilateral rib fracture, first-rib fracture, sternum fracture, thoracic vertebral fracture, bilateral pulmonary contusion, bilateral pneumothorax, subarachnoid hemorrhage, subdural hematoma, epidural hematoma, skull fracture, skull base fracture, cervical vertebral fracture, brain herniation, cerebral contusion, lumbar vertebral fracture, pelvic and abdominal cavity hematoma, liver injury, kidney injury, spleen injury, clavicle fracture, scapular fracture, femoral fracture, and pelvic fracture, and injury scores such as shock index (SI), modified shock index (MSI), injury severity score (ISS), revised trauma score (RTS), Glasgow coma score (GCS), and thoracic trauma severity (TTS) score. Univariate binary logistic regression analysis was used to screen for risk factors of death in patients with multiple trauma combined with thoracic injuries. LASSO regression and multivariate logistic regression analysis were employed to identify predictive variables and independent risk factors for mortality in those patients and to construct a regression equation. A nomogram prediction model based on the regression equation was developed using R language. Receiver operating characteristic (ROC) curves were plotted to evaluate the discrimination of the model. The ROC curves were internally validated using the Bootstrap method with 1 000 resamples. The calibration of the model was assessed using the Hosmer-Lemeshow (H-L) goodness-of-fit test. The clinical application value of the model was evaluated using decision curve analysis (DCA) and clinical impact curve (CIC) analysis. Results:There were statistically significant differences between the survival group and the death group in systolic blood pressure, SaO 2, NLR, lactate, number of combined injuries, subarachnoid hemorrhage, subdural hematoma, skull fracture, skull base fracture, brain herniation, liver injury, SI, MSI, ISS, RTS, GCS, and TTS ( P<0.05 or 0.01). The results of the univariate binary logistic regression analysis showed that the above-mentioned related variables except for systolic blood pressure were all significantly associated with death in patients with multiple trauma combined with thoracic injuries ( P<0.05 or 0.01). Five predictive variables, TTS, GCS, brain herniation, ISS, and lactate were obtained in LASSO regression analysis. The results of the multivariate logistic regression analysis showed that GCS ( OR=0.70, 95% CI 0.58, 0.83), brain herniation ( OR=46.18, 95% CI 4.27, 499.26), TTS ( OR=1.71, 95% CI 1.30, 2.24), and lactate ( OR=1.35, 95% CI 1.01, 1.80) were independent risk factors for death in patients with multiple trauma combined with thoracic injuries ( P<0.05 or 0.01). Based on the aforementioned independent risk factors, a regression formula was constructed as follows: P=e x/(1+e x), with the x=-0.36×"GCS"+3.83×"brain herniation"+0.53×"TTS"+0.30×"lactate levels"-11.03. The area under the ROC curve (AUC) of the predictive model for mortality in patients with multiple trauma combined with thoracic injuries based on the equation was 0.97 (95% CI 0.93, 1.00). The AUC was internally validated using the Bootstrap method with 1 000 samples, resulting in an AUC of 0.97 (95% CI 0.91, 1.00). The results of the H-L goodness-of-fit test showed that the bias-corrected calibration curve of the model was in good consistence with the actual curve and both of them were close to the ideal curve. In the evaluation of the clinical application value of the predictive model, the DCA results showed that the predictive model could achieve good clinical net benefit. The CIC results showed that when the threshold probability was greater than 0.7, the model-identified high-risk patients for death highly matched the patients who actually died. Conclusion:The predictive model for mortality in patients with multiple trauma combined with thoracic injuries based on GCS, brain herniation, TTS, and lactate has good predictive performance and clinical application value.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

The Portable Life Support System(PLSS),serving as a core component of the Extravehicular Activity spacesuit,must balance the requirements of life support protection and lightweight design.This study proposes a sandwich structure design based on Carbon Fiber Reinforced Polymer and validates the structural reliability of the composite backpack under launch/return segment overloads and space collision conditions through multi-scenario mechanical simulations.Simulation results demonstrate that the design achieves maximum deformations of 0.372 mm(mounting plate)under 6 g acceleration and 7.4 mm(skeleton)under 0.97 MPa impact loading,satisfying structural integrity requirements under extreme loads.The composite backpack manufactured by the autoclave molding process has passed the impact protection test under load conditions,verifying the manufacturing feasibility of the composite PLSS.This research provides a technically reliable pathway for lightweight design of EVA spacesuit structures by using composite materials,offering practical engineering value.

Objective:To investigate the occurrence and influencing factors of oral frailty among the elderly in China.Methods:General information questionnaire,Oral Frailty Scale,Sarcopenia Screening Questionnaire(SARC-F),Social Network Scale-6(LSNS-6)and Subjective Cognitive Decline Questionnaire(SCD-Q9)were used to conduct a survey in Anhui Province.A survey was conducted among 3 063 elderly people to analyze their current status and influencing factors related to oral frailty.Results:The incidence of oral frailty among the elderly in Anhui Province was 46.82％(1434/3063).Binary logistic regression analysis showed sarcopenia(OR=8.742,95％CI:7.156-10.679),social isolation(OR=1.601,95％CI:1.313-1.953),and subjective cogni-tive decline(OR=2.424,95％CI:1.905-3.085),90 years old and above(OR=2.261,95％CI:1.304-3.922)and having disability(OR=1.341,95％CI:1.040～1.729)are risk factors for oral frailty in the elderly in Anhui Province.Conclusion:The incidence of oral frailty is high among the elderly in Anhui Province.Risk factors for oral frailty include sarcopenia,social isolation,subjective cognitive decline,advanced age,and disability.

In July 2024,the Diagnosis Related Groups(DRG)2.0 is released based on the Notice from the National Healthcare Security Administration on Issuing the DRG 2.0 and Deepening the Relevant Work.Compared with DRG 1.1,version 2.0 was established based on a wider range of suggestions regarding the Adjacent Diagnosis Related Groups(ADRG),Major Comorbidity or Complication(MCC),and Comorbidity or Complication(CC)from various institutions.A list of disease diagnoses and surgical operations that are not used as grouping rules was compiled,and grouping efficacy was further improved by upgrading the algorithms for MCC and CC with the help of AI.Meanwhile,it is necessary to pay more attention to the number of cases of ADRG,the better methods to list the MCC/CC,the suggestions of various doctors and continuously standardize the data and update the grouping scheme of DRG.