Climate change is altering the Earth's water cycle system. The resulting three extreme weather events—heatwaves, droughts, and extreme precipitation—impacts urban and rural water security through multi-layered mechanisms. A primary structural disparity exists between urban and rural systems: while urban areas benefit from comprehensive and standardized pipe networks that ensure terminal water quality, rural areas often suffer from "last mile" vulnerability due to inadequate infrastructure and outdated purification facilities. Extreme weather can directly alter the microbial community structure, concentrations of chemical pollutants and physicochemical properties of source water. These alterations interfere with the efficiency of water treatment processes and ultimately compromise the integrity of distribution systems. Because distribution networks often lack real-time monitoring and adaptive response capabilities, they have emerged as the most vulnerable link in the "water source-water treatment-distribution system" chain. Based on a systematic analysis of these chain-wide impacts, this paper proposed a series of control strategies, including security frameworks based on multi-model coupling and water source protection measures, improvement of water treatment technologies, optimization of distribution systems, and development of new water quality monitoring methods. These strategies aim to enhance the climate adaptability of urban and rural drinking water systems through multi-dimensional intervention, providing a theoretical basis for constructing climate-resilient water infrastructure.

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 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.

With population aging worldwide,Alzheimer's disease(AD)has become a serious human health issue.Owing in part to the complexity of the pathogenesis of AD,effective therapeutic options are lacking.Mesenchymal stem cell-derived exosomes(MSC-Exos)have powerful regenerative properties and repair functions,providing a new direction for treatment.They are donor-derived,easily stored,natural carriers,with low immunogenicity and a low risk of tumor formation.They have shown great potential in the treatment of AD and post-treatment rehabilitation.This article introduces the pathological mechanisms of AD and characteristics of MSC-Exos,provides a detailed review of the roles of MSC-Exos in the treatment of AD,including anti-inflammatory effects,immunomodulatory effects,and related signaling pathway modulation,and summarizes recent research progress,with the aim of providing a basis for the development of novel therapeutic approaches to AD.

Objective:To investigate the epidemiological trends of viral diarrhea pathogens in children in Baotou city, and to provide reference for controlling the prevalence of viral diarrhea and guiding the development of regional vaccines.Methods:Fecal samples were collected from children under five years old hospitalized with viral diarrhea at two sentinel hospitals in Baotou from June 2023 to May 2024. Real-time PCR was used to detect group A rotavirus, norovirus, adenovirus, and astrovirus. Statistical analysis was performed using SPSS 20.0 software, with Chi-square tests conducted to assess differences. A P value<0.05 was considered statistically significant. Results:A total of 246 fecal samples were collected, including 153 from males and 93 from females. Among these, 135 samples tested positive, yielding a positivity rate of 54.88% (135/246). There were 82 positive samples from male children and 53 from female children, with no significant difference between genders. Most positive samples (51.85%, 70/135) tested positive for two viruses. Specifically, co-infections of group A rotavirus with norovirus or adenovirus accounted for 98.57% (69/70) of all co-infected cases. Significant differences in detection rates were observed across age groups (χ 2=29.803, P<0.001), with the highest positivity rates in children under one year old and in the 1-year age group. Seasonality, viral diarrhea in Baotou was more prevalent in winter and spring. The G8P[8] genotype of group A rotavirus was the predominant strain. Conclusions:From June 2023 to May 2024, viral diarrhea in hospitalized children under five years old in Baotou is primarily caused by co-infections of group A rotavirus and norovirus, with a higher incidence in preschool-aged children. The G8P[8] genotype of group A rotavirus is the dominant strain. It is recommended to strengthen vaccination and surveillance efforts for viral diarrhea in preschool children, particularly during the winter and spring seasons.

Objective:To analyze the epidemiological characteristics of influenza-like illness（ILI）and the genetic evolutionary trends of the hemagglutinin（HA）and neuraminidase（NA）genes of influenza A（H3N2）viruses isolated in Baotou during the 2022-2023 influenza season.Methods:Etiological surveillance data for ILI cases in Baotou during the 2022-2023 influenza season were collected from the China Influenza Surveillance Information System. Descriptive statistical analysis was performed on the data. HA and NA genes of 30 influenza A（H3N2）viruses were sequenced. Amino acid variation sites，glycosylation sites，drug resistance genes，and phylogenetic trees were analyzed using MEGA 11 software and the NextClade online analysis tool.Results:A total of 1 443 ILI specimens were tested，of which 241（16.70%）were positive for influenza viruses. Among the positive cases，influenza A（H3N2）virus-positive cases accounted for 75.93%（183/241）. The nucleotide sequence similarity of the HA gene between the 30 influenza A（H3N2）isolates and the vaccine strains A/Hong Kong/2671/2019（H3N2），A/Cambodia/e0826260/2020（H3N2），and A/Darwin/9/2021（H3N2）ranged from 96.83% to 98.77%，while the amino acid sequence similarity ranged from 94.63% to 99.62%. A total of 14 amino acid variation sites and 11 conserved glycosylation sites were identified in the HA gene. For the NA gene，the nucleotide sequence similarity ranged from 98.37% to 99.65%，and the amino acid sequence similarity ranged from 94.64% to 98.28%. A total of three amino acid variation sites and nine conserved glycosylation sites were found in the NA gene. None of the 30 influenza A（H3N2）isolates had mutations associated with drug resistance，and all belonged to the clade 3C.2a1b.2a.2a.3a.1.Conclusions:During the 2022-2023 influenza season in Baotou，the circulating influenza A（H3N2）viruses belong to the same evolutionary clade as the 2021-2022 vaccine strain A/Cambodia/e0826360/2020（H3N2）. The isolates from different sources share a common evolutionary origin；however，variations are observed across the genome in terms of homology，molecular mutations，and glycosylation patterns.

Objective:To investigate the status of allostatic load (AL) in patients with polycystic ovary syndrome (PCOS) and its influence on the clinical outcomes of in vitro fertilization-embryo transfer.Methods:This was a prospective study. By using convenient sampling method, 421 patients with PCOS (PCOS group) and 372 control infertility patients (control group) in the Reproductive Center of the First Affiliated Hospital of Anhui Medical University from April 2022 to January 2024 were investigated for basic information, physical examination, laboratory examination and follow-up of clinical outcomes. The total score of AL was calculated using 16 related indicators of cardiovascular system, metabolic system and immune system, and AL>3 was used as the judgment criteria for the high level AL group and the low level AL group. The differences in general data, embryo development and clinical outcomes between the groups were compared.Results:There were 222 cases (52.7%, 222/421) in PCOS low level AL group and 199 cases (47.3%, 199/421) in PCOS high level AL group. There were 214 patients (57.5%, 214/372) in the control low level AL group and 158 patients (42.5%, 158/372) in the control high level AL group. Embryo development outcomes: number of oocytes retrieved (median: 12, 12, 19, 14, respectively; P<0.001), number of two pronuclei (median: 8, 7, 11, 8, respectively; P<0.001), number of fertilization (median: 9, 9, 13, 10, respectively; P<0.001), number of metaphase of meiosis Ⅱ oocytes (median: 9, 8, 13, 10, respectively; P<0.001), number of transferable embryos (median: 5, 5, 7, 6, respectively; P<0.001), number of high-quality embryos (median: 4, 3, 6, 5, respectively; P<0.001), gonadotropin(Gn) starting dosage (median: 150, 200, 150, 200 U, respectively; P<0.001), total dosage of Gn (median: 1 800, 2 075, 1 575, 2 025 U, respectively; P<0.001), duration of Gn used (median: 10, 10, 10, 10 days, respectively; P=0.027) in the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group were significantly different. Pairings between groups showed that number of oocytes retrieved, number of two pronuclei, number of fertilization, number of metaphase of meiosis Ⅱ oocytes and number of transferable embryos in PCOS high level AL group were lower than those in PCOS low level AL group (all P<0.05); Gn starting dosage and total dosage of Gn in PCOS low level AL group were lower than those in the other three groups (all P<0.05); duration of Gn used in PCOS high level AL group was higher than that PCOS low level AL group ( P<0.05). Clinical outcomes: the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group underwent fresh transplantation [27.4% (57/208), 24.4% (38/156), 15.1% (32/212), 17.1% (33/193), respectively; P=0.006] and the proportion of transplanted day 5 embryos [82.7% (172/208), 77.6% (121/156), 91.0% (193/212), 86.5% (167/193), respectively; P=0.018] were statistically significant. There were no significant differences in fertilization rate, biochemical pregnancy rate, clinical pregnancy rate, multiple pregnancy rate and early abortion rate among the four groups (all P>0.05). Conclusion:The high level of AL in PCOS patients may affect the outcomes of embryo development, and more attention should be paid to AL in PCOS patients to reduce stress.

Isavuconazole represents a novel gen-eration of triazole antifungal agents for the treat-ment of invasive trichothecenes in adults.The phar-macokinetic profile of isavuconazole differs in spe-cial populations,including children,patients with ex-tracorporeal membrane oxygenation,those with he-patic or renal injury,patients undergoing blood puri-fication,and critically ill individuals and solid organ transplant recipients.These differences impact the safety and efficacy of patient treatment.This article presents the latest progress in the pharmacokinetic study of isavuconazole in these special populations.

Objective:To identify genetic etiology of ischemic stroke(IS)based on pleiotropy of obe-sity related genes.Methods:A discordant sib-pair study was designed based on the Fangshan family co-hort in Beijing.Body mass index(BMI)polygenic risk score(PRS)was first constructed under different P values.Using the polygenic transmission disequilibrium test(pTDT),we then compared the actual BMI genetic risk of siblings with IS to their expected risk,to analyze whether higher BMI was over-trans-mitted to siblings with IS.The single nucleotide polymorphism(SNP)that comprised the PRS over-trans-mitted with IS and that corresponded to the highest heritability of IS were identified as a pleiotropy SNPs set between BMI and IS.This set was then utilized as a candidate set to identify and verify risk SNPs as-so-ciated IS by transmission disequilibrium test.Finally,we identified independent genomic risk loci and mapped to genes,we then explored the biological function of the identified risk loci and genes by func-tional annotation and pathway enrichment.Results:A total of 541 participants were enrolled,with an average age of(58.4±8.1)years,including 326 discordant sib pairs of ischemic stroke.Compared with non-IS participants,IS participants with males,education level below junior high school,hypertension and hyperlipidemia accounted for a higher proportion(P＜0.05).For all the BMI PRS,we found that the actual genetic risk of BMI in siblings with IS was higher than their expectation,suggesting that genetic risk associated with high BMI was over-transmitted with IS.Compared with other SNP sets,the set(P＜5 × 10-4)corresponded to the best analytical statistics of pTDT and the highest heritability of IS and was identified as the pleiotropy SNP set between BMI and IS.Within this set,there were 45 SNPs having linkage and association with IS,which were located in 43 independent genomic risk loci and mapped to 40 genes.These genes were significantly enriched in the lipid metabolism pathway.The rs2232852 cor-rected by multiple tests was mapped to CYB5R1 and ADIPOR1,which were related to lipid metabolism and the ferroptosis pathway.Conclusion:Pleiotropy between BMI-related genes and IS was observed.Forty-five SNPs were found with linkage and association with IS in the pleiotropy gene set and mapped to 40 genes,which were functionally enriched in lipid metabolic pathways.The rs2232852 corrected by multiple tests during association analysis validation was mapped to CYB5R1 and ADIPOR1,which were related to lipid metabolism and the ferroptosis pathway,suggesting that lipid metabolism and ferroptosis played an important role in the development of IS.

With population aging worldwide,Alzheimer's disease(AD)has become a serious human health issue.Owing in part to the complexity of the pathogenesis of AD,effective therapeutic options are lacking.Mesenchymal stem cell-derived exosomes(MSC-Exos)have powerful regenerative properties and repair functions,providing a new direction for treatment.They are donor-derived,easily stored,natural carriers,with low immunogenicity and a low risk of tumor formation.They have shown great potential in the treatment of AD and post-treatment rehabilitation.This article introduces the pathological mechanisms of AD and characteristics of MSC-Exos,provides a detailed review of the roles of MSC-Exos in the treatment of AD,including anti-inflammatory effects,immunomodulatory effects,and related signaling pathway modulation,and summarizes recent research progress,with the aim of providing a basis for the development of novel therapeutic approaches to AD.