Objective: To understand the prevalence and related factors of depressive symptoms among primary and secondary school students in the in depth monitoring counties of China s Rural Compulsory Education Nutrition Improvement Program, so as to provide a basis for prevention and psychological intervention of depressive symptoms among children and adolescents in rural areas. Methods: In November 2022, a stratified random sampling method was adopted to collect height and weight data, basic personal and family information of 7 949 primary and secondary school students from grade three to grade nine through physical measurements and questionnaires in 56 key monitoring schools implementing the Student Nutrition Improvement Program in 7 in depth monitoring counties (Jalaid Banner in Inner Mongolia, Jinzhai County in Anhui, Mao Xian in Sichuan, Tiandeng County in Guangxi, Mian County in Shaanxi, Zhaozhou County in Heilongjiang and Youxi County in Fujian), and to obtain the information related to their depressive symptoms through the self assessment questionnaire on depression. Multivariate Logistic regression analysis was conducted to analyze the prevalence of depressive symptoms among primary and secondary school students, as well as their related factors. Results: The detection rate of depressive symptoms among primary and secondary school students in the in depth monitored counties was 23.5%. Logistic regression analysis showed that the probability of detecting depressive symptoms was higher among female students, middle school students, students whose video screen duration per day was >2 h, and students whose parents marital status was divorced or widowed ( OR =1.40, 1.64, 1.60, 1.24), and students whose sleep duration reached the recommended standard, whose parents usually accompanied them daily for time was 60-<120 min and ≥120 min, and students whose mothers literacy level was middle school graduation had lower probability of detecting depressive symptoms ( OR =0.85, 0.84, 0.71, 0.76) ( P < 0.05 ). Conclusion The detection rate of depressive symptoms among students in the in depth monitoring area is high, and targeted interventions need to be developed for students to reduce the risk of mental health problems.

Objective: To analyze the features of unhealthy lifestyle patterns among primary and secondary school students in the nutrition improvement program for rural compulsory education students (NIPRCES) areas in China in 2021 and 2023, so as to provide data support for lifestyle promotion and healthy development among primary and secondary school students. Methods: Adopting a cluster random sampling method, data on primary and secondary students aged 7-15 years from nutrition and health surveillance of China NIPRCES in 2021 and 2023 were collected. The prevalence of unhealthy lifestyles among primary and secondary students such as physical inactivity, outdoor inactivity, excessive screen time, and sleep deprivation by gender, school section, urban/rural, and region were analyzed. The reporting rates of the above indicators among primary and secondary students were compared by Chi-square test. Results: In 2021 and 2023, the rates of moderate to vigorous physical inactivity among primary and secondary school students were 79.2% and 80.4%, the rates of outdoor inactivity were 42.8% and 49.3%, the rates of excessive video time were 2.6% and 2.9%, the rates of sleep deprivation were 32.9% and 22.6%, and the differences were statistically significant( χ 2=51.86,1 071.48,18.36,3 296.99, P <0.05). In 2023, the rate of outdoor inactivity for primary and secondary students increased by 6.5 percentage points compared with 2021, and the rate of sleep deprivation decreased by 10.3 percentage points compared with that in 2021. In 2021 and 2023, the reporting rates of moderate to vigorous physical inactivity, outdoor inactivity, and sleep deprivation among girls and junior high school students were higher than those among boys ( χ 2=174.41,180.11; 175.75, 85.46 ;92.22,151.35) and elementary school students ( χ 2=136.64,5.75; 40.55,4.71;162.80,3 291.61); the reporting rates of moderate to vigorous physical inactivity( χ 2=194.43,118.60) and sleep deprivation ( χ 2=969.66,983.72) among urban students were higher than those among rural students; the reporting rates of excessive video time for boys and junior high school students were higher than those for girls ( χ 2=103.62,84.85) and elementary school students ( χ 2=810.09,626.51)( P <0.05). From a regional distribution perspective, the reporting rates of moderato to vigorous physical inactivity, outdoor inactivity, and excessive video time among primary and seconday school students in the central and western regions were lower than those in the eastern region ( χ 2= 663.44,302.78; 356.97,82.10;50.89,81.83) ( P <0.05). Conclusions Unhealthy lifestyles remain prevalent among primary and secondary students in NIPRCES areas of China. These findings underscore the need to strengthen policy implementation for promoting healthy lifestyles among primary and secondary school students.

Objective To observe the impact of cold circulation liquid temperature on ablation focus morphology of microwave ablation(MWA)for in vitro porcine liver tissue.Methods Twenty in vitro fresh porcine liver blocks were randomly divided into ice water circulation group(group A)and normal temperature circulation group(group B),respectively.Ten target ablations in each subgroups in group A and group B,i.e.A1 and B1(50 W,1 min),A2 and B2(50 W,5 min),A3 and B3(60 W,1 min),A4 and B4(60 W,5 min),A5 and B5(70 W,1 min)as well as A6 and B6(70 W,5 min)subgroups were performed using different ablation power(50,60,70 W)and ablation time(1,5 min),respectively.Then the morphology indexes of ablation foci,including longitudinal diameter(LD),transverse diameter(TD),roundness index(RI)and volume(V)were compared between subgroups in group A and B,also among subgroups within group A and B.Results Under the same ablation power and time,LD of ablation foci in subgroups of group A were all smaller than those of group B(all P＜0.05).Significant differences of RI of ablation foci were found between A1 and B1,A2 and B2,A4 and B4,A5 and B5 as well as A6 and B6 subgroups(all P＜0.05),but not between A3 and B3 subgroups(P＞0.05).However,the main effect of cold circulation liquid temperature on ablation focus TD(F=1.125)nor V(F=3.332)was not significant(both P≥0.05).Under the same cold circulation liquid temperature,significant differences of the morphology indexes of ablation foci were detected between A1 and A2,A3 and A4 as well as A5 and A6 subgroups,also between corresponding subgroups in group B(all P＜0.05).Conclusion During MWA for in vitro porcine liver tissue under constant ablation power and time,taken ice water as the cold circulation liquid was benefit to ablation focus shaped spherically.With the extension of ablation time,the larger the ablation focus,the higher the RI.

The aim of this study is to investigate the immune effect of H9 subtype avian influenza virus(AIV)NP protein on mice and lay the foundation for the development of avian influenza vi-rus(AIV)vaccine.The H9N2 virus NP gene amplification product was cloned into the pET-32a expression vector,and the protein expression was verified by SDS-PAGE and Western blot,and the immune effect was evaluated by measuring the secretion of supernatant multicytokines in mouse splenocytes culture.The results showed that the total length of the coding region sequence of NP gene was 1 497 bp,NP recombinant proteins exist in both soluble and insoluble protein forms,and the specific bands were visible in Western blot.After immunizing mice,serum produces IgG-bind-ing antibodies with antibody titers of 1∶40 000.Compared with the control group,IL-2,IL-5 and IL-13 were significantly increased(P＜0.001),and the secretion of IL-6 was significantly increased compared with the control group.IL-4 and IL-12 p70 secretions were elevated compared with con-trols,but there was no significant difference.Compared with the control group,the secretions of IL-1β,IL-18,GM-CMF,TNF-α and IFN-γ were inhibited,but the difference was not significant(P＞0.05).The results showed that NP recombinant protein is a good immunogen,laying a foundation for in-depth research on influenza vaccine.

Objective:To explore the value of the amyloid-tau-neurodegeneration (ATN) framework in neuroimaging based on PET for diagnosing mild cognitive impairment (MCI) and Alzheimer′s disease (AD), and analyze its relationship with clinical cognition.Methods:From May 2022 to March 2024, a total of 98 cases (23 males and 75 females, age (67.8±8.6) years) with a diagnosis of AD, MCI, or non-AD (control patients, CP) who underwent 18F-FDG, 18F-AV45, and 18F-AV1451 PET/CT imaging in the Second Affiliated Hospital of Guangzhou Medical University were included retrospectively. The clinical data, Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA) scores were recorded. Cases were divided into MCI group, mild AD group, moderate AD group, moderate-severe AD group, and CP group. PET images were visually and semi-quantitatively evaluated. SUV mean and SUV ratio (SUVR) were obtained from independent brain regions of 18F-FDG ( n=8), 18F-AV45 ( n=14) and 18F-AV1451 ( n=14). ROC curve analysis was performed with clinical diagnosis as a criterion. The consistency between visual assessment and the clinical diagnosis was analyzed by Cohen′s Kappa coefficient. Semi-quantitative comparisons between groups were performed using the independent-sample t test, one-way analysis of variance, Mann-Whitney U test, or Kruskal-Wallis rank sum test. Age was used as a covariate to calculate the partial correlation coefficient between SUVR and cognitive scores. Results:The sensitivity and specificity of comprehensive visual assessment in diagnosing AD+ MCI were 87.65%(71/81) and 14/17 respectively, showing a moderate consistency with clinical diagnosis ( Kappa=0.60, P<0.001). Semi-quantitative analysis showed that 18F-FDG uptakes in all independent brain regions of MCI patients were higher than those of AD patients, whereas the uptakes of 18F-AV45 and 18F-AV1451 were lower ( t values: 2.66-3.95, z values: 4.98-15.04, all P<0.05). The difference in 18F-AV45 uptake among the three subgroups of AD was relatively small ( H values: 0.46-4.06, F values: 0.03-0.08, all P>0.05). Except for the medial temporal and occipital lobes, the 18F-AV1451 uptake in the moderate-severe AD group tended to be higher than that in the moderate and mild AD groups, though not statistically significant ( H values: 0.20-5.17, all P>0.05). 18F-FDG PET semi-quantitatively distinguished MCI from CP with a high sensitivity (13/14), 18F-AV45 demonstrated a high sensitivity for diagnosing AD+ MCI (92.59%, 75/81), and 18F-AV1451 had a high specificity for distinguishing AD from MCI (14/14) (AUCs: 0.87, 0.90 and 0.92). The uptakes of 18F-FDG in gray matter of AD and MCI patients were positively correlated with MMSE and MoCA scores ( r values: 0.30-0.43, 0.29-0.45, all P<0.05), while the uptakes of 18F-AV45 and 18F-AV1451 were negatively correlated with MMSE and MoCA scores ( 18F-AV45, r values: from -0.39 to -0.30, from -0.38 to -0.30, all P<0.05; 18F-AV1451, r values: from -0.50 to -0.28, from -0.53 to -0.28, except for medial temporal lobe P>0.05, all others P<0.05). Conclusion:The PET-based neuroimaging ATN framework is helpful for early diagnosis of MCI and AD, as well as for AD staging, and may reflect the disease progression and clinical cognitive status of AD to a certain extent.

Objective:To understand the molecular epidemiological characteristics of unique recombinant forms (URFs) in newly reported HIV-1 patients in Hangzhou, and provide theoretical support for prevention and control of AIDS.Methods:The blood samples of newly-diagnosed HIV-1 infected cases who received no antiviral therapy from 2019 to 2023 were collected, pol gene was amplified by RT-PCR and nested PCR, followed by sequencing. The URFs were screened using phylogenetic tree, followed by recombinant analysis. Genetic distances between URFs sequences were calculated and molecular transmission networks were constructed. The calibrated population resistance program (CPR) was used to analyze transmissible drug-resistant mutations. Results:A total of 222(5.0%, 222/4 471) URFs pol gene sequence were obtained, and the recombination types were CRF01_AE/CRF07_BC (60.4%, 134/222), CRF01_AE/C (11.7%, 26/222), CRF01_AE/B (9.5%, 21/222), CRF01_AE/B/C (8.1%, 18/222), B/C (7.6%, 17/222) and CRF55_01B/CRF07_BC (2.7%, 6/222), respectively. 78.8% (175/222) were infected by men who have sex with man(MSM), whoes mean age was 31.3±10.5. The proportion of URFs increased from 4.0% (34/843) to 7.4% (60/807) from 2019 to 2023. Under the optimal gene distance threshold of 1.5%, the molecular network access rate was 49.5% (110/222), included 23 clusters. We found a large active transmission cluster with 39 cases mixed homosexual and heterosexual, the recombination types was CRF01_AE/CRF07_BC, and the average gene distance was 0.005. Prevalence of URFs transmissible resistance was 3.2% (7/222). Conclusions:URFs are mainly produced and transmitted in young MSM, which shows an increasing trend year by year. There is a large active transmission cluster required major attention and effective intervention to prevent further expansion. At the same time, the occurrence and transmission of URFs should be continuously monitored to understand the clusters and drug resistance dynamics.

Electric vertical takeoff and landing(eVTOL)aircraft was introduced from the aspects of basic concept,development history,classification mode,characteristic and advantage.The feasibility of eVTOL aircraft used in aeromedical rescue was discussed in terms of time,space,transport capacity and safety.It's pointed out that eVTOL aircraft would be applied widely in pre-hospital emergency care,inter-hospital transfer and emergency medical rescue.[Chinese Medical Equipment Journal,2024,45(2):82-86]

Objective To carry out rigid-body inverse dynamics modelling and analysis of a self-designed 6RSS parallel bio-inspired masticatory robot.Methods Firstly,the functions of kinematic variables including translational/rotational velocities and accelerations were derived for rigid-body inverse dynamics modelling.Secondly,the rigid-body inverse dynamics model was established with the Newton-Euler's law.Finally,the chewing motion trajectories of the oral health volunteers were tracked and numerical calculations were carried out in the case where the robot was subjected to a chewing reaction force.Results Numerical calculations showed that the driving torque and the constraint force of the robot peaked when the chewing reaction force was at its maximum.Conclusion The external force has a large impact on the inverse dynamics of the robot,and theoretical references are provided for the motion control and optimal design of the robot.[Chinese Medical Equipment Journal,2024,45(3):16-22]

Objective To screen the anti-Helicobacter pylori gastritis active components of the ethyl acetate extract of Alpinia officinarum Hance.Methods The"knock-out"strategy combined with high-performance liquid chromatography(HPLC)detection was developed to separate the components of the ethyl acetate extract of A.officinarum while obtaining the negative samples without the components.A human gastric epithelial cell(GES-1)model of H.pylori gastritis was established,and the levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),interleukin-8(IL-8)and interleukin-1β(IL-1β)in the supernatant of the cells were determined by enzyme-linked immunosorbent assay(ELISA).Results The total flavonoid fraction,the negative fraction without total diphenylheptanoids,the negative fraction without 5-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-heptanone(DHPA),and galangin significantly reduced IL-6 levels in the supernatant of H.pylori infected GES-1 cells at a concentration of 8 μg·mL-1 with 24 h incubation.The total flavonoid fraction strongly inhibited the release of IL-6,TNF-α,IL-8,and IL-1β from H.pylori gastritis GES-1 cells at a concentration of 16 μg·mL-1.Conclusions The total flavonoid fraction is the major anti-H.pylori gastritis active component of the ethyl acetate extract of A.officinarum.The results lay the foundation for further elucidation of the material basis of A.officnarum against H.pylori gastritis.

Objective To observe area of coagulation necrosis after microwave ablation(MWA)of rabbit liver showed on contrast-enhanced ultrasound(CEUS)in comparison with pathological findings.Methods Twenty-five healthy male experimental rabbits were equally randomly divided into L0,M0,H0,M7 and M14 groups.MWA was achieved with different power and time,and then CEUS and pathological examinations were performed,respectively.Four target areas of rabbit liver were ablated under 20 W for 1 min in L0 group,under 30 W for 1 min in M0 group and under 30 W for 3 min in H0 group,and the ablated areas were observed on the same day after MWA,while 2 target areas of rabbit liver were ablated under 30 W for 1 min in M7 and M14 groups,and the ablated areas were observed 7 days and 14 days after MWA,respectively.The ablated foci and ablated foci+edema band(inflammatory reaction band,IRB)showed on CEUS and pathology were compared,and their differences and changes with time going were analyzed.Results On the day of ablation,the extent of ablation foci,ablation foci+IRB as well as IRB in L0,M0 and H0 groups showed on CEUS were all larger than pathological findings under light microscopy(all P＜0.05),and the difference value of the length of the ablation foci between 2 methods increased sequentially among group L0,M0 and H0(all adjusted P＜0.05).Seven days after ablation,the area of ablation foci measured with CEUS in M 7 group was slightly larger than that measured with pathology(adjusted P=0.045),but no significant difference of the length nor the short diameter was found(both adjusted P＞0.05).Fourteen days after ablation,no significant difference of the length,the short diameter nor the area of ablation foci was detected between 2 methods in M14 group(all adjusted P＞0.05).The length,short diameter and area of ablation foci in M0 group measured with CEUS or pathology were all smaller than those in M 7 and M14 groups(all adjusted P＜0.05),while no significant difference was found between the latter 2 groups(all adjusted P＞0.05).Conclusion On the day of MWA of rabbit liver with different power and time settings,the areas of ablation foci,ablation foci+IRB and IRB showed on CEUS were larger than pathological findings.The range of ablation foci showed on CEUS 7 days after ablation was basically in line with pathology,indicating that CUES should be reexamined 7 days after ablation to evaluate the actual extent of coagulation and necrosis of ablation foci.