Objective: To investigate the association between screen time (ST) during leisure time and anxiety-depression symptoms among middle school students, so as to provide a basis for formulating relevant intervention measures. Methods: From November to December 2023, a stratified cluster random sampling method was used to select 2 542 students from junior and senior high school in Taiyuan City. A self designed questionnaire, the Generalized Anxiety Disorder Scale (GAD-7), and the Patient Health Questionnaire (PHQ-9) were used to investigate ST and anxiety/depression symptoms among middle school students. The Logistic regression model was used to explore the association of ST with symptoms of anxiety and depression, as well as with anxiety and depression comorbiditles (CAD). Results: The detection rates of anxiety symptoms, depression symptoms, and CAD were 13.69%, 15.77%, and 10.11%, respectively. The median ST was 2.00 h/d [interquartile range ( IQR =2.38) for weekly averages], with 0.33 h/d ( IQR =1.67) on work days and 5.00 h/d ( IQR=5.50) on rest days. Logistic regression analysis indicated that the total ST of mobile phones during rest days ( OR =1.07, 1.10, 1.11) and the averages ST of mobile phones over a week ( OR = 1.20 , 1.22, 1.29), as well as the total ST of all screen types during rest days ( OR =1.04, 1.04, 1.05) and the averages ST of all screen types over a week ( OR =1.08, 1.09, 1.21) were positively correlated with anxiety symptoms, depression symptoms, and CAD (all P <0.01). Conclusions Among middle school students in Taiyuan City, screen time is positively correlated with symptoms of anxiety or depression and the comorbidity of anxiety and depression, especially smartphone screen time and weekend screen use. Therefore, measures should be implemented to reduce unnecessary screen time among middle school students, especially the use of mobile phones, in order to mitigate the occurrence of anxiety and depression.

OBJECTIVE To analyze the risk factors for multidrug-resistant organism （MDRO） infection in patients with prolonged invasive mechanical ventilation （IMV） complicated by ventilator-associated pneumonia （VAP） in the intensive care unit （ICU）， thus providing a reference for improving the clinical effect of VAP treatment in this region. METHODS A retrospective analysis was performed on the clinical data of patients who were admitted to the ICU in Shexian Branch of the Second Affiliated Hospital of Zhejiang University School of Medicine （hereinafter referred to as “our hospital”） from October 2022 to February 2025， received prolonged IMV， and developed VAP. The distribution and drug resistance of pathogens were statistically analyzed. Patients were divided into the MDRO group and the non-MDRO group according to whether an MDRO infection occurred. Univariate analysis and multivariate Logistic regression analysis were used to screen independent risk factors for MDRO infection. RESULTS A total of 281 pathogenic strains were cultured from 97 patients， including 262 Gram-negative bacteria （93.24%）， 9 Gram-positive bacteria （3.20%）， and 10 fungi （3.56%）. The main Gram-negative bacteria were Pseudomonas aeruginosa， Klebsiella pneumoniae subspecies pneumoniae， and Acinetobacter baumannii. The former two showed high resistance rates （all≥25%） to common antibiotics such as imipenem， while A. mail：64375689@qq.com baumannii demonstrated high resistance to most antimicrobial agents. The main Gram-positive bacteria were Staphylococcus aureus subspecies aureus and S. haemolyticus， which were resistant to multiple antibiotics such as clindamycin （resistance rates all＞30%）. Among 281 pathogenic strains， 121 were MDRO， 62 were resistant to carbapenems， and 33 produced extended-spectrum β-lactamases. The serum albumin＜28 g/L， ICU stay≥14 days， and use of benzodiazepines were independent risk factors for MDRO infection in patients with prolonged IMV and VAP in our hospital’s ICU （odds ratios were 3.289， 2.991 and 2.680， 95% confidence intervals were 1.183-9.144， 1.021-8.765， and 1.012- 7.094， respectively， P＜0.05）. CONCLUSIONS Pathogens infecting patients with prolonged IMV and VAP in the ICU are mainly Gram-negative bacteria， with P. aeruginosa， K. pneumoniae subspecies pneumoniae and A. baumannii， accounting for a high proportion， and the drug resistance situation is severe. Serum albumin＜28 g/L， ICU stay≥14 days， and use of benzodiazepines are independent risk factors for MDRO infection in such patients.

OBJECTIVE To explore the effects of meropenem exposure and degradation levels on clinical efficacy in patients with purulent meningitis （PM）. METHODS A total of 131 PM patients treated with meropenem at the Affiliated Suzhou Hospital of Nanjing Medical University from January 2022 to June 2025 were prospectively included. Relevant data were collected and divided into a cured group （91 cases） and a non-cured group （40 cases） based on the efficacy. High-performance liquid chromatography-tandem mass spectrometry was used to determine the concentration of meropenem and its open-loop metabolites. Risk factors that affect efficacy were screened， and their predictive power and correlation were evaluated by univariate analysis， and multivariate Logistic regression analysis， receiver operating characteristic （ROC） curves， and correlation analysis. RESULTS Univariate analysis showed that serum creatinine， creatinine clearance rate， minimum inhibitory concentration of meropenem ≥16 μg/mL， cerebrospinal fluid red blood cell count， cerebrospinal fluid white blood cell count， cerebrospinal fluid glucose content， blood trough concentration， blood open-loop metabolite concentration/trough concentration ratio， and intrathecal injection were all correlated with efficacy （P＜0.05）. The results of multiple Logistic regression analysis showed that serum creatinine blood open-loop metabolite concentration/trough concentration ratio， intrathecal injection， and cerebrospinal fluid glucose content were influencing factors for suboptimal anti-infective ltt efficacy （P＜0.05）. ROC curve analysis showed that when the blood open-loop metabolite concentration/trough concentration ratio was greater than 2.854 （AUC＝0.647）， serum creatinine was less than 59.5 μmol/L （AUC＝0.647）， and cerebrospinal fluid glucose content was less than 3.37 mmol/L （AUC＝0.709）， the risk of treatment failure significantly increased （P＜0.05）. Correlation analysis showed that the blood trough concentration of meropenem was positively correlated with the concentration of its open-loop metabolites （R 2＝0.134 5， P＜0.000 1）. CONCLUSIONS Insufficient exposure level and rapid degradation of meropenem are key mechanisms affecting the anti-infective efficacy of PM. Elevated blood open-loop metabolite concentration/ trough concentration ratio， low serum creatinine level， lack of intrathecal injection， and low cerebrospinal fluid glucose content are independent risk factors for poor efficacy.

Twelve derivatives of asiatic acid were synthesized through acylation, alkylation, oxidative dehydrogenation and other reactions using asiatic acid from usoxane-type pentacyclic triterpenoids as the parent compound. Their structures were confirmed by 1H NMR and 13C NMR, and determined to be novel compounds never reported in literature. Through the MTT method, high-expression human cancer cells (A549 and SGC-7901) were selected for a preliminary in vitro anti-tumor activity study on these compounds. Among them, the IC50 of compound I1 were 11.39 and 9.08 μmol/L respectively, and those of compound I2 were 12.64 and 9.15 μmol/L respectively, which were close to those of sorafenib, a common drug for clinical use. The experimental results show that the synthesized asiatic acid derivatives have certain anti-proliferative effects on the two types of human cancer cells, A549 and SGC-7901, significantly higher than those of asiatic acid. Compounds I1 and I2 show quite strong anti-proliferative effects on human cancer cells A549 and SGC-7901.

Objective:To investigate the effects of Zhibai Dihuang Pills on neurons of cognitive dysfunction in D-galactose (D-gal) model mice.Methods:Totally 60 male mice were divided into four groups using a random number table method: control group, model group, donepezil group, and Zhibai Dihuang Pills group, with 15 mice in each group. Except for the control group, the other groups were subcutaneously injected with D-galactose solution at a dosage of 125 mg/kg once a day for 8 weeks to prepare the aging model. Mice in the donepezil group were intragastrically administered donepezil solution at a dosage of 0.65 mg/kg, and those in the Zhibai Dihuang Pills group were intragastrically administered Zhibai Dihuang Pills solution at a dosage of 1.56 g/kg. The control group was intragastrically administered an equal volume of physiological saline once a day for 8 weeks. The object recognition test and Morris Water Maze were used to assess object recognition memory and spatial learning memory abilities of mice in each group, respectively. Hematoxylin-Eosin (HE) staining and Nissl staining were employed to observe the morphology of neurons in the hippocampal region; Golgi staining was used to observe neuronal dendritic spines; Western Blot was used to detect the protein expression levels of PI3K, p-Akt/Akt, glycogen synthase kinase 3β (GSK3β), postsynaptic density protein-95 (PSD-95), and synaptophysin (SYP) in the hippocampus region; RT-qPCR was performed to detect mRNA expression of PI3K, Akt and GSK3β in the hippocampus region.Results:Compared with the model group, the recognition index in both the donepezil group and the Zhibai Dihuang Pills group increased ( P<0.05), the escape latency was shortened ( P<0.05), the platform crossings times and the target quadrant dwell time increased ( P<0.05), the number of nerve cells in the hippocampal region increased, arranged closely, the number of Nissl bodies increased, the morphology returned to normal, and the density of dendritic spines increased; the protein expressions of PI3K, PSD-95, and SYP in the hippocampal region and the ratio of p-Akt/Akt increased ( P<0.01), the mRNA level of PI3K increased ( P<0.01 or P<0.05), and the protein and mRNA levels of GSK3β decreased ( P<0.01 or P<0.05). Conclusion:Zhibai Dihuang Pills can improve the learning and memory ability and rescue neuronal damage in D-gal model mice, and the mechanism may be related to the activation of PI3K/Akt pathway and the restoration of synaptic connections.

Intravascular large B-cell lymphoma(IVLBCL)is an aggressive extranodal large B-cell lymphoma,cocurrence in the same organ with other malignancies is very rare,especially in the lung.Here,we report a rare case of lung adenocarcinoma with IVLBCL.The patient was admitted to the hospital due to diarrhea associated with fever and cough.A computed tomography(CT)scan of the chest showed an irregular patchy high-density shadow in the upper lobe of the right lung with ground-glass opacity at the margin.After admission,the patient was given anti-infection treatment,but still had inter-mittent low fever(up to 37.5 oC).The pathological diagnosis of percutaneous lung biopsy(PLB)was lepidic-predominant ad-enocarcinoma with local infiltration,which was proved to be invasive nonmucinous adenocarcinoma of the lung with IVLBCL after surgery.This paper analyzed the clinicopathological characteristics and reviewed the relevant literature to improve the knowledge of clinicians and pathologists and avoid missed diagnosis or misdiagnosis.

Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.

Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.

Objective To explore the therapeutic effect of bicyclol(BIC)on rat model of myocardial fibrosis and its possible mechanism.Methods Twenty-four SPF male SD rats were randomly di-vided into sham group,model group,low-and high-dose groups,with 6 rats in each group.Except for the sham group,all other groups were injected with 5 mg/(kg·d)isoproterenol by tail vein to establish myocardial fibrosis model,and the low-and high-dose groups were administered by ga-vage with 100 and 200 mg/(kg·d)BIC,respectively for 14 consecutive days.HE staining and Masson staining were used respectively to observe the severity of myocardial injury and fibrosis.Western blot assay was employed to detect the protein expression of Collagen Ⅰ,Collagen Ⅲ,al-pha smooth muscle actin(α-SMA),methyltransferase-like protein 3(METTL3),α-ketoglutarate-dependent dioxygenase AlkB homolog 5(ALKBH5)and YTH domain family protein 1(YTHDF1)in rat myocardium.Results Compared with the sham group,myocardial cell necrosis and myocardial fibrosis were significantly more serious in the model group.Low-and high-dose BIC treatment reduced myocardial cell rupture and necrosis and myocardial fibrosis when com-pared with the model group.The expression levels of Collagen Ⅰ,Collagen Ⅲ,α-SMA,METTL3 and YTHDF1(P＜0.05)were significantly higher,and that of ALKBH5(0.58±0.02 vs 0.88±0.07,P＜0.05)was notably lower in the myocardial tissues of the model group than the sham group.While,both doses of BIC treatment significantly reversed above changes in protein levels(P＜0.05).Conclusion BIC can effectively alleviate myocardial structural damage and interstitial collagen deposition in rats with isoproterenol-induced myocardial fibrosis,and its mechanism may be related to m6A methylation modification.

Objective:To survey the perceived social support status and influencing factors of medical staffs working in community health service institutions in Shanghai Minhang District .Methods:The study was a cross-sectional study. From September 2022 to January 2023, a survey on the status of perceived social support was conducted among 181 medical staffs working in community health service institutions in Shanghai Minhang District. The self-designed general information questionnaire, perceived social support scale, general self-efficacy scale, quality of professional life scale, and trait coping style scale were used in the survey. The effects of demographic characteristics, general self-efficacy, empathy fatigue and trait coping style on perceived social support status of community medical workers were analyzed.Results:A total of 181 questionnairs were distributed and 178 valid ones returned with a valid recovery rate of 98.3%. In three dimensions of perceived social support, family support scored (17.11±8.87), friend support scored (17.08±8.41), other support scored (19.89±4.09), and the total score of understanding social support was (60.99±11.71). There were 2 cases of low support status (1.12%), 81 cases of intermediate support status (45.51%), and 95 cases of high support status (53.37%). Univariate analysis showed that there were significant differences in perceived social support among participants with different ages, marriage status, majors, professional titles, job satisfaction, positive or negative coping styles, general self-efficacy, and empathy fatigue ( P<0.05). Multivariate logistic regression analysis showed that people aged 40 and above had a higher degree of perceived social support than those under 40 ( OR=2.792, 95% CI: 1.051-7.418, P<0.05); compared with public health professionals, clinical medicine, nursing and other medical technique professionals had a higher degree of perceived social support ( OR=4.024, 95% CI: 1.479-10.953; OR=2.941, 95% CI: 1.031-8.393; OR=3.996, 95% CI: 0.543-29.409, all P<0.05); compared with those who were less satisfied with their self-assessment work, participants who were more satisfied or generally satisfied with their self-assessment work had lower perceived social support ( OR=0.200, 95% CI: 0.051-0.781; OR=0.320, 95% CI: 0.146-0.701, all P<0.05); compared with those with mild and moderate empathy fatigue, participants with high empathy fatigue had lower perceived social support ( OR=0.406, 95% CI: 0.182-0.909, P<0.05). Except supporting primary and secondary traumatic stress, the total score of perceived social support and its dimensions were positively correlated with empathy satisfaction; and negatively correlated with job burnout and secondary traumatic stress. Regression analysis shows that empathy satisfaction had a positive predictive effect on overall scores of perceived social support and its dimensions of friend support and other support capacity. Conclusions:The social support status of community healthcare workers in Shanghai Minhang district is generally acceptable. However, it is important to pay special attention to the social support status of those who are under 40 years old, have a background in public health, are satisfied with their work, and experience a high level of empathy fatigue. Measures should be implemented to specifically enhance empathy satisfaction among healthcare workers; timely guidance and intervention should be provided accordingly.