Objective: To explore the association between negative life events and smartphone addiction among middle school students, so as to provide theoretical support and practical guidance for prevention and intervention of smartphone addiction among middle school students. Methods: Using cluster sampling, 8 890 students were selected to survey from 27 junior high schools and 3 senior high schools in a district of Shenzhen in 2022 (baseline) and 2023 (followup). Data were collected through selfresigned questionnaires on basic information, the Smartphone Addiction Scale-Short Version, and the Adolescent Selfrating Life Events Checklist. Mixedeffects models were employed to analyze the association. Results: Compared to 2022, the punishment scores of middle school students in 2023 [1.00 (0.00, 6.00) and 1.00 (0.00, 6.00)] decreased (Z=4.27), while the scores of interpersonal stress, learning stress and adaptation [4.00(0.00, 8.00), 4.00(0.00, 8.00); 4.00(1.00, 8.00), 5.00(2.00, 9.00); 2.00 (0.00, 6.00), 3.00 (0.00, 7.00)] increased (Z=-3.04, -8.36, -6.80) (P<0.01). Mixedeffects models revealed a positive doseresponse relationship between negative life events and smartphone addiction (OR=1.08-1.17, P<0.01). Stepwise regression showed independent positive effects of interpersonal stress (OR=1.05), academic stress (OR=1.03), and adaptation stress (OR=1.11) on smartphone addiction (P<0.01). Subgroup analysis of nonaddicted students in 2022 confirmed persistent associations for academic stress (OR=1.03) and adaptation (OR=1.07) (P<0.01). Conclusion Negative life events exhibit a positive doseresponse relationship with smartphone addiction, particularly interpersonal stress, academic stress, and adaptationrelated events.

Objective: To explore the longitudinal association between only-child status and smartphone addiction among middle school students, so as to provide a basis for establishing family intervention measures for smartphone addiction in middle school students. Methods: In October 2022 and October 2023, a preliminary survey and follow-up were conducted among 8 759 middle and high school students from 30 schools in a district of Shenzhen. A self-designed questionnaire was used to determine whether the students were the only-child, and the Chinese Version of the Smartphone Addiction Scale-Short Version (C-SAS-SV) was utilized to assess the students smartphone addiction status. A multilevel mixed-effects model and subgroup analysis were applied to examine the association between only-child status and smartphone addiction among middle school students. Results: During 2022 to 2023, the prevalence of smartphone addiction in the cohort of middle school students increased from 24.1% to 25.2%. Compared with only-child, non-only child were more likely to be addicted to smartphones (adjusted model: OR =1.2, 95% CI =1.1-1.4) and also scored higher on smartphone addiction (adjusted model: β =0.9, 95% CI =0.2-1.5)( P <0.05). Subgroup analysis further revealed that compared to baseline, non-only child demonstrated an increased prevalence of smartphone addiction (adjusted model: OR = 1.2 , 95% CI =1.0-1.5) and higher addiction scores (adjusted model: β =0.8, 95% CI =0.2-1.5) after one year( P <0.05). Conclusions Non-only child face higher risk of smartphone addiction. Under the current population policy, it is crucial to address smartphone addiction among middle school students who is not only child.

Objective: To explore the potential causal association between adolescent compulsive behaviour and smartphone addiction based on longitudinal data, so as to provide reference for the establishment of adolescent smartphone addiction interventions. Methods: A preliminary survey and follow-up were conducted on 8 907 middle and high school students in a district of Shenzhen in 2022 and 2023, respectively. Compulsive behaviours were measured by using the Mental Health Inventory for Middle School Students-60 Items (MMHI-60), smartphone addiction was assessed by using the Smartphone Addiction Scale-Short Version ( SAS- SV), and the associations between compulsive behaviours and smartphone addiction were analysed by using multilevel mixed-effects models and subgroup analyses. Results: Smartphone addiction detection rates among middle school students were significantly associated with genders, father s education level, mother s education level, study load subgroups, and whether or not they were single-parent families, and there were statistical differences ( χ 2=17.21-175.34, P <0.05). Students with compulsive behaviours were 2.98 times more likely to develop smartphone addiction than those without compulsive behaviours ( OR=2.98, 95%CI=2.77-3.22, P <0.05). Subgroup analysis of middle school students without smartphone addiction in the first year found that compulsive behaviours significantly predicted smartphone addiction ( OR= 1.76 , 95%CI=1.54-2.01, P <0.05). Conclusion There is a potential causal association between obsessive-compulsive behaviours and smartphone addiction in middle school students, and obsessive-compulsive behaviours in middle school students could significantly predicted the occurrence of smartphone addiction.

OBJECTIVE To evaluate the efficacy and safety of letermovir in preventing cytomegalovirus （CMV） infection after allogeneic hematopoietic stem cell transplantation （allo-HSCT）. METHODS A retrospective cohort study was conducted， enrolling patients who underwent allo-HSCT at the Department of Hematology， Shanghai General Hospital Affiliated to Shanghai Jiao Tong University School of Medicine， from August 30， 2022， to February 21， 2024. Patients who initiated letermovir prophylaxis within 28 days post-transplantation were assigned to the experimental group （99 cases）， while those who did not initiate letermovir within this period were assigned to the control group （18 cases）. The incidence and clinical characteristics of CMV infection （including the number of wangranran@xinhuamed.com.cn CMV infection cases， the number of cases progressing to CMV disease， recurrent CMV disease， onset time of CMV infection， and treatment duration）， immune function recovery within 120 days post-transplantation， and the occurrence of transplantation-related complications （including CD4+ and CD8+ T-cell recovery， Epstein-Barr virus infection， acute graft-versus-host disease， human herpesvirus 6 infection， and posttransplant lymphoproliferative disorders） and adverse events were recorded. Univariate and multivariate Cox regression analyses were performed to identify factors influencing CMV infection. RESULTS A total of 117 patients were included， among whom 15 developed CMV infection， 5 progressed to CMV disease， and 2 experienced recurrent CMV disease. The CMV infection rate in the experimental group was significantly lower than that in the control group （P＜0.001）， and the onset time of CMV infection was significantly delayed （P＝0.014）. The proportion of patients with CD4+ T-cell counts ≥200 cells/μL in the experimental group was significantly lower than that in the control group （P＝0.022）. During the follow-up period， elevated creatinine levels were observed in 1 patient， and nausea and vomiting were observed in 2 patients. Multivariate Cox regression analysis revealed that the use of high-dose corticosteroids was a risk factor for CMV infection （HR＝6.230， 95%CI of 1.255-30.926， P＝0.025）， while initiating letermovir within 28 days post-transplantation was a protective factor （HR＝0.125， 95%CI of 0.045-0.348， P＜0.001）. CONCLUSIONS Early initiation of letermovir after allo-HSCT significantly reduces the CMV infection rate and delays the onset of infection， with favorable short-term safety.

OBJECTIVE To compare the efficacy of ceftazidime and avibactam （CZA） monotherapy and combination therapy in the treatment of carbapenem-resistant Gram-negative bacteria （CRGNB） infections， and analyze the influencing factors. METHODS The data of patients with CRGNB infection who received CZA treatment from January 2020 to March 2025 were collected retrospectively. The patients were divided into the CZA monotherapy group （52 cases） and the CZA combination therapy group （85 cases） according to treatment regimen. The therapeutic effects of the two groups were compared， and the drug susceptibility results of isolated strains were recorded. The multivariate Logistic regression model was used to analyze the factors influencing clinical efficacy of CRGNB patients. RESULTS The bacterial clearance rate of patients was significantly higher in the CZA combination therapy group than in the CZA monotherapy group （P＝0.012）. However， when comparing the 30-day mortality rate and the clinical response rate between the two groups， no statistically significant differences were observed （P＞0.05）. Among the isolates， carbapenem-resistant Klebsiella pneumoniae had the highest sensitivity to tigecycline （87.3%） and carbapenem-resistant Pseudomonas aeruginosa showed 90.9% sensitivity to amikacin. Five isolates were resistant to CZA. The multivariate Logistic regression showed， lung infection， receiving continuous renal replacement therapy （CRRT）， and inadequate treatment courses were significantly correlated with clinical treatment failure （P＜0.05）. CONCLUSIONS For CRGNB infection， the clinical efficacy of CZA combination therapy is similar to that of monotherapy， but the combination therapy has a higher bacterial clearance rate. Lung infections， receiving CRRT and inadequate treatment courses （No. are independent risk factors for clinical treatment failure.

ObjectiveThe U6 promoter is an essential element for driving sgRNA expression in the clustered regularly interspaced short palindromic repeat sequences/CRISPR-associated protein 9（CRISPR/Cas9）gene editing system in dicotyledonous plants. Endogenous U6 promoters typically exhibit higher transcriptional activity， which can significantly improve gene editing efficiency. This study aims to identify endogenous U6 promoters in Artemisia annua to optimize its CRISPR/Cas9 gene editing system， which holds significant importance for its molecular breeding. MethodsOn the basis of the highly conserved U6 snRNA sequences in Arabidopsis thaliana， endogenous U6 promoters were screened in the A. annua genome. Expression vectors were constructed with candidate AaU6 promoter driving the firefly luciferase （LUC） reporter gene， and then transiently transformed into Nicotiana benthamiana. Transcriptional activities of the promoters were measured and compared by in vivo imaging and the Dual Luciferase Reporter assay. ResultsEight endogenous U6 promoters were successfully cloned from A. annua. Sequences alignment revealed that all these promoters contained the two conserved cis-acting elements， upstream sequence element （USE） and TATA-box， which affected their transcriptional activity. Dual-luciferase activity assays indicated that the transcriptional activities of AaU6-3， AaU6-1， and AaU6-5 were significantly higher than that of the Arabidopsis AtU6-26 promoter， with AaU6-3 exhibiting the highest activity. ConclusionThis study identified three endogenous AaU6 promoters with high transcriptional activity in A. annua， providing key functional elements for establishing an efficient gene editing system in A. annua. These findings will contribute to advancing precision molecular breeding and high-quality germplasm innovation in A. annua.

OBJECTIVE: Benzylisoquinoline alkaloids (BIAs) have pharmacological functions and clinical use. BIAs are mainly distributed in plant species across the order Ranunculales and the genus Phellodendron from Sapindales. The BIA biosynthesis has been intensively investigated in Ranunculales species. However, the accumulation mechanism of BIAs in Phellodendron is largely unknown. The aim of this study is to unravel the biosynthetic pathways of BIAs in Phellodendron amurens. METHODS: The transcriptome and metabolome data from 18 different tissues of P. amurense were meticulously sequenced and subsequently subjected to a thorough analysis. Weighted gene co-expression network analysis (WGCNA), a powerful systems biology approach that facilitates the construction and subsequent analysis of co-expression networks, was utilized to identify candidate genes involved in BIAs biosynthesis. Following this, recombinant plasmids containing candidate genes were expressed in Escherichia coli, a widely used prokaryotic expression system. The purpose of this genetic engineering endeavor was to express the candidate genes within the bacteria, thereby enabling the assessment of the resultant enzyme activity. RESULTS: The synonymous substitutions per synonymous site for paralogs indicated that at least one whole genome duplication event has occurred. The potential BIA biosynthetic pathway of P. amurense was proposed, and two PR10/Bet v1 members, 14 CYP450s, and 33 methyltransferases were selected as related to BIA biosynthesis. One PR10/Bet v1 was identified as norcoclaurine synthase, which could catalyze dopamine and 4-hydroxyphenylacetaldehyde into (S)-norcoclaurine. CONCLUSION Our studies provide important insights into the biosynthesis and evolution of BIAs in non-Ranunculales species.

Objective:To investigate the computed tomography (CT)-based integrated deep learning model for qualitative and quantitative classification of hepatic portal vein.Methods:The retrospective study was conducted. The CT imaging data of 291 patients undergoing upper-abdomen enhanced CT examination in the Beijing Tsinghua Changgung Hospital of Tsinghua University from October 2017 to January 2019 were collected. There were 195 males and 96 females, aged (51±12)years. The hepatic portal vein was reconstructed using the three-dimensional reconstruction system. Three-dimensional point cloud was input to the encoder model to obtain the three-dimen-sional reconstructed vectorized representation, which was used for qualitative classification and quantitative representation classification. Measurement data with normal distribution were repre-sented as Mean± SD, and comparison between groups was conducted using the paired t test. Count data were repre-sented as percentages or absolute numbers, and comparison between groups was analyzed using the paired chi-square test. Results:(1) Three-dimensional reconstruction of portal vein and anatomical classification. Three-dimensional structure was reconstructed in the 291 patients. Classification of main hepatic portal vein showed 211 cases of Akgul type A, 29 cases of Akgul type B, 16 cases of Akgul type C, 10 cases of Akgul type D, and 25 cases of unclassifiable. (2) Prediction of qualitative classification of main hepatic portal vein. Of the 291 patient samples, 25 unclassifiable or poor quality samples were excluded, 266 samples were used for automated qualitative classification of the main portal vein by machine model. There were 211 cases of Akgul type A, 29 cases of Akgul type B, 26 cases of Akgul type C&D. The Macro-F1 of 266 patients was 61.93%±40.50% and the accuracy was 84.99%, versus 32.38%±19.81% and 61.65% of Random classifier, showing significant differ-ences between them ( t=7.85, χ2=62.89, P<0.05). (3) Quantitative representation of portal vein classification. The probabilities of quantitative classification for Akgul qualitative classification of similar samples included P@1 as 73%±45%, P@3 as 70%±37%, P@5 as 69%±35%, P@10 as 67%± 32%, mean reciprocal rank(MRR) as 80%±34%, versus 57%±50%, 58%±35%, 58%±32%, 58%± 30%, 70%±37% of the baseline model, showing significant differences between the two analytical methods ( t=5.22, 5.11, 5.00, 4.99, 3.47, P<0.05). Conclusion:The automated classification model for the hepatic portal vein structure was constructed using CT-based three-dimensional reconstruc-tion and deep learning technology, which can achieve automatic qualitative classification and quanti-tatively describe the hepatic portal vein structure.

Schizophrenia is a common chronic mental disorder.Cognitive dysfunction is one of its core symptoms,which severely affects the social functioning of patients.Currently,antipsychotic medication treatments have poor efficacy in improving cognitive functions.Recent studies have found that metformin can improve cognitive dysfunction in patients with schizophrenia.However,the mechanism of action remains unclear.This review summarizes the therapeutic effects of metformin on cognitive dysfunction in schizophrenia patients such as improving insulin resistance,repairing neuronal damage,regulating neuroimmunity,and combating oxidative stress,thereby providing new insights for the treatment of cognitive dysfunction in schizophrenia.