BACKGROUND:In recent years,there has been an explosion of research in the field of physical activity and cognition of older adults,and the research hotspots and topics in this field are constantly evolving.However,a comprehensive review of the literature in this field is lacking. OBJECTIVE:To explore the current international research hotspots and contents in the field of physical activity and cognition of older adults using bibliometrics. METHODS:The Web of Science Core Collection Database,including SCI-EXPANDED,SSCI,A&HCI,CPCI-S,CPCI-SSH,BKCI-S,BKCI-SSH,ESCI,CCR-EXPANDED,IC,etc.,was searched for relevant literature in English.CiteSpace software was used to visualize and analyze 2593 documents collected in the Web of Science database. RESULTS AND CONCLUSION:The evolution of the topics of physical activity and cognition of older adults includes five stages:research on companion robots for older adults,research on the risk of diseases such as dementia,research on cognitive ability and its related ability,research on the relationship between physical activity level and cognitive ability in older adults,and research on different intervention methods and their mechanisms.The research in this field tends to be diversified.On the basis of the research on diseases and cognitive risk reduction,more attention has been paid to the effects of different physical activity modalities on cognition and the related mechanisms,which is the current research hotspot and will be the main research trend in the future.

Objective: To explore the relative importance of different food attributes and levels in food decision making of school aged children, and to understand their meal preferences, so as to provide the evidence for formulating precise intervention strategies for dietary behaviours of school aged children. Methods: From May to June 2024, a total of 854 children aged 11 to 15 years old were selected from 2 middle schools (each school in urban and rural areas) in both Hubei Province and Anhui Province by stratified cluster random sampling method to conduct a D-optimal discrete choice experiment. The mixed Logit model was used to analyze children s preference for meal attributes and different levels, and to calculate the relative importance (RI) of attributes and willingness to pay (WTP) in meal choices. Results: The included five food attributes had statistical significance on meal choice of school aged children ( P <0.05). The relative importance of food attributes affecting the meal choices of school aged children in descending order were dining mode ( RI =31.26%), food varieties ( RI =30.56%), cooking method( RI =23.84%), taste( RI =8.06%) and price ( RI =6.27%). Among them, school aged children preferred home cooked meals ( β =0.74) (WTP=86.3 yuan),varied foods(grain/tubers+vegetables+fish, meat, eggs and beans) ( β =0.61) (WTP=71.9 yuan), fried/roasted cooking ( β =0.51) and spicy taste ( β =0.33).Price was negatively correlated with meal choices( β =-0.01) ( P <0.05). Based on residential area and body mass index (BMI), the stratified analysis showed that dining mode was highest in the relative importance for rural children with overweight and obese children ( RI =31.28%,34.17%), both of whom preferred home cooked meals ( β =0.76, 0.91), and meals containing fish, meat, eggs and beans with grain/tubers or grain/tubers and vegetables in terms of food choice (area: β =0.53, 0.53 ; BMI: β =0.55, 0.56) ( P <0.05). Conclusions School aged children have different preferences for different attributes of meals. The quality of school meals should be improved,the cost of buying healthy meals should be reduced,targeted family health education should be carried out,and healthy cooking methods should be advocated.

Objective: To investigate the trends in mortality and life loss of gastric cancer in Wenzhou City, Zhejiang Province from 2014 to 2023, so as to provide the evidence for formulating the prevention and control strategy for gastric cancer. Methods: The surveillance on causes of death data of permanent residents in Wenzhou City were collected through the Wenzhou Chronic Disease Monitoring and Management Information System from 2014 to 2023. The crude mortality of gastric cancer was calculated, and standardized by the data from the Sixth Chinese National Population Census in 2010. The life loss were measured using potential years of life lost (PYLL) and rate of potential years of life lost (PYLLR). The characteristics of mortality and life loss of gastric cancer in different genders and age groups were described. The trends in mortality and PYLLR of gastric cancer were analyzed using the average annual percent change (AAPC). Results: Totally 17 080 deaths were reported due to gastric cancer in Wenzhou City from 2014 to 2023, accounting for 12.58% and ranking third in the order of malignant tumor deaths. The crude mortality of gastric cancer was 20.73/105, and the standardized mortality was 15.22/105, showing decreasing trends (AAPC=-3.311%, -6.470%, both P<0.05). The crude mortality of gastric cancer was 29.22/105 in men and 11.61/105 in women, with standardized mortality rates of 20.81/105 and 8.74/105 (both P<0.05). The crude mortality of gastric cancer appeared a tendency towards a rise with increasing age (P<0.05), reaching the highest rate of 225.88/105 in the group aged 80 to <85 years. The PYLL and PYLLR of gastric cancer were 107 607.50 person-years and 1.37‰. The PYLLR appeared a tendency towards a decline from 2014 to 2023, with AAPC of -6.667% (P<0.05). Conclusions The mortality and PYLLR of gastric cancer in Wenzhou City appeared a tendency towards a decline from 2014 to 2023. Men and the elderly populations were the key groups for the prevention and treatment of gastric cancer.

Background The decline of physical activity in the elderly due to aging may increase the risk of sarcopenia. Currently, there is a lack of evidence from large natural populations on the relationship between PA and sarcopenia. Objective To explore the relationship between PA and sarcopenia in the elderly aged 60 years and above in 10 provinces (autonomous regions) of China. Methods Data were retrieved from the 2022—2023 round of the China Development and Nutrition Health Impact Cohort. Personal basic information and PA data were collected by questionnaire survey. Skeletal muscle mass was measured by bio-electrical impedance analysis, muscle strength was measured using a grip dynamometer, and physical performance was reflected by 6-meter walk speed. The Asian Working Group for Sarcopenia (AWGS) 2019 criteria were used to diagnose sarcopenia. Light physical activity (LPA) duration, moderate-to-vigorous physical activity (MVPA) duration, and total physical activity volume were calculated. A total of 3326 residents aged ≥60 years with complete data were selected as the survey participants. Multiple logistic regression models and restricted cubic splines (RCS) were used to assess the association between PA duration/volume and sarcopenia. Results In 10 provinces (autonomous regions) of China, the prevalence of sarcopenia in the elderly aged 60 years and above was 5.5% (95%CI: 4.7%, 6.2%). The logistic regression analysis showed that compared with the elderly reporting 0-7.0 h·week⁻¹ in LPA duration, the risk of sarcopenia in the elderly with LPA duration of >14.0-21.0 h·week⁻¹ was reduced by 51% (OR=0.49, 95%CI: 0.26, 0.96). Compared with the elderly with total physical activity ≥15.0 metabolic equivalent of task (MET)-h·week⁻¹, those with <7.5 MET-h·week⁻¹ had a 2.24-fold increased risk of sarcopenia (OR=2.24, 95%CI: 1.17, 4.29). The RCS results found that LPA duration and total physical activity volume each showed a nonlinear dose-response relationship with the risk of sarcopenia (P_overall<0.05, P_non-linear<0.05). Compared with the elderly with an LPA duration of 0 h· week⁻¹, the risk of sarcopenia in the elderly with an LPA duration of 12.6 h· week⁻¹ was the lowest (OR=0.42, 95%CI: 0.21, 0.83). Compared with the elderly with a total physical activity volume of 15.0 MET-h· week⁻¹, the elderly with a total physical activity volume of 46.0 MET-h· week⁻¹ had the lowest risk of sarcopenia (OR=0.57, 95%CI: 0.38, 0.84). There was no statistically significant association between weekly MVPA duration and the risk of sarcopenia (P>0.05). Conclusion Increasing weekly LPA duration and total physical activity volume would help to reduce the risk of sarcopenia.

Objective To systematically evaluate the radiation impact of radioactive sources used in online elemental analyzers in cement enterprises on the surrounding environment, and to provide a scientific basis for radiation monitoring and safety management at the application sites of this type of radioactive sources. Methods A statistical analysis was conducted on 15 cement enterprises in Guangxi Province using online elemental analyzers with ²⁵²Cf as the radioactive source. On-site investigation of radiation safety management and on-site monitoring of radiation environment were performed, followed by an evaluation based on the collected data. Results Although the gamma radiation ambient dose equivalent rate and neutron ambient dose equivalent rate increased around the sites using online elemental analyzers with ²⁵²Cf as the radioactive source, they all met the requirements of the Radiological Health Protection Requirements for Instruments with Sealed Sources (GBZ 125—2009). Conclusion Under the current usage and management conditions, the application of this type of radioactive sources has controllable radiation impact on the surrounding environment, and will not pose a threat to public health and environmental safety. However, continuous strengthening of radiation safety management measures and regular radiation monitoring work are still needed to ensure the safe use of radioactive sources, further reducing potential radiation risks and providing strong guarantees for the safe application of radioactive sources in online elemental analyzers in cement enterprises.

In recent years, China has been facing the dual challenges of declining fertility rates and births, with male reproductive health issues, especially the decline in semen quality, identified as a pivotal contributor to this phenomenon. Meanwhile, accumulating evidence indicates that air pollutants, an increasingly severe environmental problem, can damage semen quality not only directly through their biological toxicity but also indirectly by disrupting the composition of microbial communities in the gut and semen, thereby dysregulating immune function, endocrine homeostasis, and oxidative stress responses. The gut microbiota and semen microbiota, as important components of the human microecosystem, play crucial roles in maintaining reproductive health. This article comprehensively reviewed the research progress on the potential effects of air pollutants (particulate matter and gaseous pollutants), gut microbiota, and semen microbiota on semen quality. Specifically, it elucidated the mechanisms of interaction between these factors and explored how they affect male fertility.

Objective: To investigate the trends in mortality and life loss due to falls among the elderly in Wenzhou City, Zhejiang Province, so as to provide the basis for formulating prevention and control measures for falls among the elderly. Methods: The data on fall-related deaths among the elderly aged 60 and above in Wenzhou City were collected through the Wenzhou Chronic Disease Monitoring and Management Information System from 2015 to 2023. The crude mortality was calculated and standardized using the data from the Sixth National Population Census in 2010. The life loss were measured using potential years of life lost (PYLL), average years of life lost (AYLL), and potential years of life lost rate (PYLLR). The trends in mortality and life loss among the elderly were analyzed using the annual percent change (APC) and average annual percent change (AAPC). Results: There were 11 378 deaths due to falls among the elderly in Wenzhou City from 2015 to 2023, with a crude mortality of 82.67/100 000 and a standardized mortality of 65.32/105, which appeared no significant changing trend (AAPC=3.401%、2.995%,both P>0.05). There was a tendency towards a rise from 2019 to 2023 (APC=12.592%、11.507%, both P<0.05). The majority of falls occurred at home, with 6 312 cases accounting for 55.48%. The primary types of fall-related deaths were slips, trips, and falls on the same level, with 8 541 cases representing 75.07%. The crude mortality and standardized mortality of falls in males were 76.63/105 and 60.86/105, which were lower than that in females at 88.72/100 000 and 70.33/100 000 (both P<0.05), and the trends were consistent with the overall population. The crude mortality of falls among the elderly increased with age (P<0.05). From 2015 to 2023, the crude mortality of falls among the elderly aged 60 to <65 years showed an upward trend (AAPC=4.860%, P<0.05), while no significant trend was observed in other age groups (all P>0.05). The PYLL was 5 123 person-years, the AYLL was 0.45 years per person, and the PYLLR was 0.37‰. From 2015 to 2023, PYLL showed an upward trend (AAPC=5.477%, P<0.05). The PYLL, AYLL, and PYLLR for males were 3.08 times, 3.48 times, and 2.67 times those of females, respectively. Conclusions From 2015 to 2023, the mortality of falls among the elderly in Wenzhou City had remained relatively stable. However, PYLL showed an upward trend. Males and older seniors were key groups for falls prevention. It is recommended to enhance health education and promote age-friendly home modifications to prevent falls among the elderly.

The E protein of dengue virus type Ⅱ was presented on ferritin of Helicobacter pylori to construct a novel dengue nanoparticle vaccine candidate,and the immunological indexes of the vac-cine were evaluated,aiming to provide new ideas for the development of dengue vaccine.The re-combinant plasmid of E-Ferritin was optimized and synthesized,and then transfected into HEK-293F cells.The recombinant protein was expressed,identified,purified and analyzed.Mice were im-munized with E-Ferritin nanoparticle vaccine by intramuscular injection on the hind limbs on the day 0,14 and 28.ELISA,neutralization test,flow cytometry and lymphocyte proliferation test were used to detect the levels of specific antibodies,neutralizing antibodies,CD3+,CD4+and CD8+T lymphocytes in spleen cells and the proliferation of spleen lymphocytes after specific stimulation.The target protein with a size of about 69 kDa was expressed in the cells with a single band.The purified protein concentration was 0.407 g/L,and the purity was 82.32％.The results from transmission electron microscopy showed that E-Ferritin protein could be recombined into a particle structure with a particle size of about 50 nm.The results of mouse immune experiments showed that E-Ferritin protein had good immunogenicity.The average specific antibody titer of E-ferritin protein in serum was 1∶92 160 after immunization 42 d.The main subclass of antibody was IgGl.The results of flow cytometry showed that E-Ferritin as an immunogen could induce higher levels of CD4+and CD8+T lymphocyte immune response.In lymphocyte proliferation test,the level of specific stimulation in the vaccine group was significantly higher than that in the non-specific stimulation group.In conclusion,the dengue virus envelope protein ferritin nanoparticle vaccine constructed in this study has good immunogenicity,which can provide reference for the de-velopment of new dengue vaccine candidates.

Dengue virus(DENV)diseases are a serious threat to human life and health,and there is no effective vaccine for DENV in China.In this study,a recombinant subunit candidate vaccine for DENV-2 was prepared.Using the ED Ⅲ gene of DENV-2 as the target gene,the recombinant eu-karyotic expression plasmid was constructed and transfected into suspension cells to express the target protein.The appropriate immune dose was screened to immunize mice and the immunogenic-ity was analyzed.The recombinant eukaryotic expression vector of DENV was successfully con-structed and transfected into HEK-293F to express the target protein,which was about 15 kDa in size.The mice were immunized with different doses of recombinant protein mixed with aluminum salt as adjuvant and the immunogenicity was analyzed.On the 35th day after the first immuniza-tion,the serum specific antibody levels of mice in the three protein immunization groups were sig-nificantly higher than those in the adjuvant group and PBS group,and the specific antibody levels of 10 μg D2EDⅢ protein group and 20 μg D2EDⅢ protein group were 1.43 and 1.56 times higher than those of 5 μg D2EDⅢ protein group,respectively.The antibody typing was biased to IgG1,in-dicating that the recombinant subunit candidate vaccine of DENV-2 prepared in this study mainly improved humoral immune response,but there was no significant difference in IgG1 antibody levels among the three protein immunization groups.Considering the immune effect and vaccine cost,the optimal target protein immunization dose per mouse was determined to be 10 μg.In this study,a recombinant subunit candidate vaccine of DENV-2 was prepared,which provides a refer-ence for the prevention of dengue virus.

Based upon the experiences of planning and implementation of "Dynamic changes of Torque Teno virus load in Chinese renal transplant recipients with immunosuppressive therapy: A multi-center prospective observational double-blind cohort study", this article explored the current status and major difficulties of investigator-initiated multi-center prospective clinical trials of kidney transplantation in China. Various issues of organization design and implementation process management were discussed for enhancing the quality of implementing the relevant trials.