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 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.

Objective:To investigate the effect of ligation methods of inferior mesenteric artery (IMA) on preserving left colic artery (LCA) in laparoscopic radical resection of rectal cancer.Methods:The prospective randomized controlled study was conducted. The clinical data of 864 patients who underwent laparoscopic radical resection of rectal cancer at Renji Hospital of Shanghai Jiaotong University School of Medicine from January 2020 to December 2024 were selected. Patients were randomly divided into the low ligation group and high ligation group using a random number table. Patients of the low ligation group underwent laparoscopic radical resection of rectal cancer with preserving LCA by low ligation of IMA and apical lymph node dissection, and patients of the high ligation group underwent laparoscopic radical resection of rectal cancer with traditional high ligation of IMA. Observation indicators: (1) grouping of the enrolled patients; (2) intraoperative conditions; (3) postoperative pathological examination; (4) postoperative recovery. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of count data between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data between groups was conducted using the non-parametric test. Results:(1) Grouping of the enrolled patients. A total of 864 patients with rectal cancer who underwent laparoscopic radical resection of rectal cancer were screened for eligibility, including 410 males and 454 females, aged (63±11)years. All 864 patients were randomly divided into the low ligation group and high ligation group, with 432 patients in each group. There was no significant difference in gender, age, body mass index, carcinoembryonic antigen, distance from tumor to anal margin, diabetes, hypertension, neoadjuvant radiochemotherapy, IMA subtypes and IMA length between the two groups ( P>0.05), ensuring comparability. (2) Intraoperative conditions. All patients of the two groups successfully completed surgery, with no errors in blood vessel ligation during operation or conversion to open surgery. There was a significant difference in time of IMA dissection between the low ligation group and high ligation group [(31±11)minutes vs. (28±9)minutes, t=4.39, P<0.05], and there was no significant difference in total operation time, volume of intra-operative blood loss or prophylactic stoma rate between the two groups ( P>0.05). (3) Postopera-tive pathological examination. There was a significant difference in the number of lymph node dissected between the low ligation group and high ligation group (1.8±1.4 vs. 1.5±1.4, t=2.51, P<0.05), and there was no significant difference in tumor diameter, the total number of lymph node dissected, total lymph node positive status, No.253 lymph node positive status, TNM staging between the two groups ( P>0.05). (4) Postoperative recovery. The time to postoperative first flatus and the number of anastomotic leakage of patients in the low ligation group were (74±22)hours and 16 cases, versus (78±20)hours and 31 cases in the high ligation group, respectively, showing significant differences in the above indicators between the two groups ( t=2.52, χ2=5.06, P<0.05). There was no significant difference in the time to postoperative initial liquid food intake, duration of post-operative hospital stay, duration of abdominal drainage tube indwelling, duration of anal tube indwelling, postoperative wound infection, pulmonary infection, intestinal obstruction, or urinary dysfunction between the two groups ( P>0.05). None of patients in the two groups had readmission or death during the postoperative 30 days. Conclusion:Low ligation of IMA in laparoscopic radical resection of rectal cancer can guide precise LCA preservation, which is beneficial for accelerating the recovery of intestinal function and reducing the incidence of anastomotic leakage.

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.

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.

Objective To compare the effects of different detector combinations of 320-row CT on the image quality and radiation dose of head CT to explore the feasibility of using a wide detector for head CT scanning.Methods Totally 100 patients underwent head CT scanning due to trauma or cerebrovascular disease at some hospital from June to August 2023 were collected prospectively and divided into group A and group B by using block randomization grouping method,with the length of the block group being 2 and 50 patients in each group.In group A,all the detectors had the widths at z-axis direction being 40×0.5 mm and head scanning was completed after multiple exposures;in group B,detector combinations with widths of 280×0.5 mm or 320×0.5 mm were chosen based on the patient's head size in the head-foot direction(z-axis direction),and head scanning was performed with a single-turn exposure.The remaining scanning and image reconstruction parameters in the two groups were kept completely consistent.The head image quality of the 2 groups was evaluated objectively and scored subjectively by 2 radiologists.The volume CT dose index(CTDIvol),dose length product(DLP)and exposure time of the 2 groups were recorded,and the effective dose(ED)was calculated.SPSS 22.0 software was used for statistical analysis.Results In terms of objective evaluation of image quality,at the level of the parietal skull group B had the CT value of gray matter,image noise and contrast to noise ratio(CNR)of the images higher than those of group A,and the differences were statistically significant(all P<0.05);at the level of the posterior skull group B had the CT values of gray and white matter,image noise and air noise lower while CNR higher than those of group A,and the differences were statistically significant(all P<0.05).In terms of subjective scoring of image quality,at the levels of parietal and posterior skull group A behaved better than group B,and the differences were statistically significant(all P<0.05).In group A 5 patients had obvious motion artifacts affecting the diagnosis and the image quality scores not higher than 2,and secondary scanning had to be carried out;In group B all the patients had no obvious motion artifacts and met the diagnosis requirements.When compared with group A Group B had the CTDIvol,DLP,ED and exposure time decreased by 17.44%,17.24%,17.48%and 85.53%,respectively,and the differences were statistically significant(all P<0.05).Conclusion A wide detector gains advantages over a 20 mm detector in image quality when 320-row CT is used for head CT scanning,with the diagnosis requirements satisfied.[Chinese Medical Equipment Journal,2025,46(4):57-62]

Objective To investigate whether orexin A(orexin-A),orexin receptor 1(OX1R)and orexin receptor 2(OX2R)are involved in iron death and lipid peroxidation regulation in chronically unpredictable mild stress(CUMS)depressed rats.Methods Forty rats were randomly divided into a normal group(NC group),a modeling group(Mod group),an exogenous Orexin-A group(Orexin-A group,),and an OX1R/OX2R blocker group(TCS1102 group),with 10 rats in each group.After modeling,behavioral changes were observed using the absent field test(OFT),sugar-water preference test(SPT)and forced swimming test(FST),action potential(PA)and resting membrane potential(Vm)were detected by diaphragm-clamp technique,Orexin-A/OX1R/OX2R protein expression in orbital frontal cortex(OFC)tissues was detected by protein immunoblotting(WB)method,RT-PCR The mRNA expression of glutathione peroxidase 4(GPX4),long chain acyl coenzyme A synthase 4(ACSL4)and cysteine/glutamate transporter light chain(SLC7A11)were detected by RT-PCR method,and the intensity of the expression of rat glial fibrillary acidic protein(GFAP)and lipid peroxidation product 4-hydroxynon-enal(4-HNE)was labeled by immunofluorescence.Results Compared with the NC group,there were significant differences in OFT,SPT and FST behavioral in the Mod group(P<0.01),with lower number of PA issuance(P<0.001),higher Vm(P<0.01),and higher expression of Orexin-A/OX1R/OX2R proteins(P<0.01,P<0.001,and P<0.001).GPX4/SLC7A11 mRNA expression was decreased(P<0.01),ACSL4 mRNA expression was elevated(P<0.01),and the fluorescence intensity expression of both GFAP and 4-HNE was elevated(P<0.001);the number of PA issuance was decreased in the Orexin-A group compared to the Mod group(P<0.05),and the Orexin-A/OX1R/OX2R protein expression was elevated(P<0.05,P<0.01),GPX4/SLC7A11 mRNA ex-pression was decreased(P<0.05),ACSL4 mRNA expression was elevated(P<0.05),and the fluorescence in-tensity of GFAP and 4-HNE expression was elevated(P<0.05,P<0.01);the TCS1102 group had higher expres-sion of GFAP and 4-HNE in the behavioral,Orexin-A/OX1R/OX2R protein expression,PA and Vm,GPX4/SLC7A11/ACSL4 mRNA,and GFAP and 4-HNE fluorescence intensity expression showed a reversed trend.Con-clusions Orexin-A/OX1R/OX2R is involved in the regulation of iron death and lipid peroxidation in CUMS de-pressed rats,and the mechanism may be that Orexin-A enhances the excitability of OFC neurons by activating the OX1R/OX2R signaling pathway,up-regulates the expression of the key factor of iron death,ACSL4/4-HNE,and decreases the expression of GPX4/SLC7A11,which promotes lipid peroxidation and iron death.

Objective To investigate the value of MRI of the sternal end of clavicle in bone age assessment in Chinese population,especially its applicability in the determination of criminal responsible age.Methods A total of 431 patients aged from 10.00 to 29.99 years with neck or chest MRI were retrospectively collected.According to the Schmeling grading method,the epiphyseal development of the clavicle MRI was divided into five grades.The consistency of methods was evaluated.The correlation and general descriptive analysis between MRI grades and age was analyzed.The sex difference was analyzed.Curve fitting was used to establish a nonlinear model between age and grades.Results The grades of clavicle MRI showed a significant age-related trend(Figure 2),and the correlation was 0.861(0.887 in males and 0.840 in females).Except for grade 1,there was no significant difference between males and females in other grades.The minimum age of male grade 3 was greater than 14 years old,and the minimum age of female grade 3 was greater than 16 years old.The minimum age in grade 4 and grade 5 was over 18 years old in both sexes.The best curve fitting model was cubic model for both sexes(R2=0.805 for men and 0.722 for women).Conclusion Clavicle MRI can be used for the assessment of bone age in Chinese population.Complete epiphyseal plate closure can be used as a reliable indicator for the determination of age at 18 years old,and it is expected to achieve radiation-free forensic bone age assessment.

Objective:To evaluate the value of spectral CT quantitative parameters in predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC).Methods:A total of 100 HCC patients who underwent surgical resection and were pathologically diagnosed in the Affiliated Cancer Hospital of Xiangya Medical College of Central South University from January 2020 to January 2023 were retrospectively enrolled. According to pathological grading, the patients were divided into the microvascular invasion group (invasion group, n=60) and the non-vascular invasion group (non-invasion group, n=40). Serological indicators and spectral CT quantitative parameters were compared between the two groups. Receiver operating characteristic (ROC) curve was used to analyze the value of spectral CT quantitative parameters in predicting MVI of HCC. Results:The serum alpha-fetoprotein (AFP) level in the invasion group was higher than that in the non-invasion group, with a statistically significant difference ( P<0.05). There were no statistically significant differences in serum carcinoembryonic antigen (CEA) and carbohydrate antigen 199 (CA-199) levels between the two groups (all P>0.05). In the invasion group, arterial phase iodine concentration, arterial phase normalized iodine concentration, venous phase iodine uptake reduction rate, arterial phase effective atomic number, and energy spectrum curve slope were all higher than those in the non-invasion group, with statistically significant differences (all P<0.05); there were no statistically significant differences in venous phase iodine concentration, venous phase normalized iodine concentration, and venous phase effective atomic number between the two groups (all P>0.05). The rates of peritumoral enhancement in the arterial phase and irregular tumor margin in the invasion group were higher than those in the non-invasion group, with statistically significant differences (all P<0.05); there was no statistically significant difference in tumor capsule between the two groups ( P>0.05). ROC curve analysis showed that the areas under the curve (AUC) of arterial phase iodine concentration, arterial phase normalized iodine concentration, venous phase iodine uptake reduction rate, arterial phase effective atomic number, and energy spectrum curve slope for predicting MVI in HCC were 0.812, 0.885, 0.726, 0.823, and 0.788, respectively. Conclusions:Spectral CT quantitative parameters are helpful to improve the preoperative diagnostic efficiency of MVI in HCC and can effectively predict MVI in HCC. Especially, arterial phase normalized iodine concentration has high application value in judging whether there is MVI in HCC.

Objective:To compare postoperative anal function recovery between laparoscopic subtotal colectomy with antiperistaltic cecorectal anastomosis and laparoscopic total colectomy with ileorectal anastomosis for slow transit constipation.Methods:This multicenter retrospective cohort study enrolled patients meeting the following criteria: (1) severe constipation symptoms (<2 bowel movements/week), absent or insignificant defecation urge, abdominal distension, requiring laxatives to maintain bowel movements or laxatives being ineffective; (2) constipation symptoms for over 5 years, ineffective after >2 years of medical treatment, with strong desire for surgery; (3) significantly prolonged colon transit time (>72 hours) without significant gastric or small intestinal transit dysfunction; (4) no organic colonic lesions confirmed by colonoscopy and abdominal CT. Exclusion criteria: (1) patients undergoing open surgery; (2) exclusion of outlet obstruction constipation (e.g., rectocele, rectal prolapse, puborectalis spasm) by functional defecation MRI; (3) comorbid psychiatric disorders; (4) missing clinical data or loss to follow-up (postoperative follow-up <24 months). Based on these criteria, clinical and follow-up data were collected from 220 patients who underwent either laparoscopic subtotal colectomy with antiperistaltic cecorectal anastomosis (LSC group, n = 115) or laparoscopic total colectomy with ileorectal anastomosis (LTC group, n = 105) for slow transit constipation between January 2013 and December 2022. Subjective anal function (Constipation Severity Score and Wexner Fecal Incontinence Score) and objective anal function (positive rate of rectoanal inhibitory reflex [RAIR] and anorectal manometry) were observed preoperatively and at 6, 12, and 24 months postoperatively. Results:No significant differences were found in baseline characteristics between the two groups (all P >0.05). All surgeries were completed successfully without major significant complications. Subjective anal function assessment: At 24 months postoperatively, Constipation Severity Scores decreased significantly compared to preoperative scores in both groups [LSC group: (25.2±2.8) vs. (2.9±1.8), P <0.001; LTC group: (25.8±2.9) vs. (2.8±1.9), P<0.001]. No significant differences were found between the groups at 6, 12, and 24 months postoperatively (all P>0.05). Wexner Fecal Incontinence Scores at 24 months were significantly lower than those at 6 months in both groups [LSC group: (12.9±1.8) vs. (3.9±2.5), P<0.001; LTC group: (12.6±1.8) vs. (5.4±2.4), P<0.001]. Although no significant difference was found at 6 months ( P = 0.190), the LSC group had significantly lower Wexner scores than the LTC group at 12 and 24 months postoperatively (both P < 0.001). Objective anal function assessment: (1) Positive RAIR rate: Preoperative positive RAIR rates were 33.0% (38/115) in the LSC group and 25.7% (27/105) in the LTC group ( P > 0.05). At 24 months, positive rates increased significantly in both groups [LSC: 66.1% (76/115); LTC: 63.8% (67/105)] compared to preoperative rates (both P<0.001), but no significant differences were found between groups at 6, 12, and 24 months (all P>0.05). (2) Resting pressure (RP) and squeeze pressure (SP): No significant differences were found in preoperative RP and SP between groups (all P>0.05). The LSC group had significantly higher RP and SP than the LTC group at 6 and 12 months postoperatively (all P<0.05), but no significant differences were found at 24 months ( P>0.05). Conclusion:Both laparoscopic subtotal colectomy with antiperistaltic cecorectal anastomosis and laparoscopic total colectomy with ileorectal anastomosis are safe for patients with slow transit constipation. However, laparoscopic subtotal colectomy with antiperistaltic cecorectal anastomosis offers superior postoperative anal function recovery.