To explore the effects of different exercise prescriptions on glycemic metabolism in East Asian patients with type 2 diabetes mellitus (T2DM) and to compare the differences in the impact of population characteristics and exercise components on glycemic metabolism.

To investigate the correlation between vitamin D nutritional status and insulin resistance in pubertal adolescents.

Establishing a natural population prospective cohort represents a sophisticated systematic project that spans multiple disciplines and research directions, requiring comprehensive consideration of diverse factors. Both international and domestic practices have accumulated substantial experience and achievements in this field. These prospective cohorts are typically developed through collaborative efforts among research institutions, generating systematic insights into construction backgrounds, objectives, design frameworks, implementation strategies, and management protocols. This study conducts an in-depth investigation into the current status of natural population prospective cohort development globally and domestically, systematically summarizing progress in development history, current status, and research advancements. The findings aim to inform strategic planning in China’s related domains, thereby facilitating the advancement of natural population prospective cohort research.

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 investigate the clinical features in children with invasive pneumococcal disease (IPD) and early warning indicators of severe case.Methods The case data of 101 children inpatients with IPD isolated Streptococcus pneumoniae (Sp) at least once blood culture in this hospital from January 2007 to De-cember 2021 were collected retrospectively.The children patients were divided into the pediatric intensive care unit (PICU) group (35 cases) and general ward group (66 cases) according to whether or not entering PICU during hospitalization.The general clinical data,infection types and results of drug sensitivity test and bacteri-al strain serotype identification were compared between the two groups and analyzed.Results Compared with the general ward group,the male proportion,proportions of complicating nervous system disease and iron-defi-ciency anemia,winter incidence rate,disturbance of consciousness,convulsion,dyspnea,heart rate increase,oc-currence rate of vomiting and diarrhea,proportion of peripheral blood neutrophilic granulocytes,C reactive protein (CRP),lactic dehydrogenase (LDH) level,Hb<90 g/L,LDH>700 U/L,creatine kinase isoenzyme-MB (CK-MB) abnomality,proportions of bacterial meningitis,sepsis and severe pneumonia in the PICU group were higher,the proportion of 3-97 percentile of body weight,bronchopneumonia and no-focus blood stream infection were lower,WBC,Hb and albumin level were lower,and the differences were statistically significant (P<0.05).Eleven kinds of serotypes were identified in this study,ranking the top five in order were 6B,14,19F,23F and 19A.Pneumococcal 13-valent conjugate vaccine (PCV13) could cover 96.9％ of the IPD sero-types.The multivariate logistic regression analysis showed that consciousness disturbance,convulsion,per-centage of neutrophils increase,Hb<90 g/L,LDH>700 U/L and CK-MB abnormality indicated the condition of IPD children patients was critical,which was the early-warning indicator of entering PICU (P<0.05).Con-clusion Severe IPD lacks the early specific early-warning indicator,and the cover rate of PCV13 is high.

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 investigate the epidemiological characteristics of herpangina (HA) and its correlation with the incidence of hand, foot and mouth disease (HFMD) in children aged ≤6 years in Yinzhou District of Ningbo from 2017 to 2022.Methods:Epidemiological characteristics of HA in children aged ≤6 years were analyzed based on the electronic medical record data and public health management data from 2017 to 2022 collected from the Health Information Platform of Yinzhou. The incidence of HFMD was calculated using the infectious disease reporting data from the public health management data. Autoregressive integrated moving average model and cross-correlation function were used to evaluate the correlation between the incidence of HA and HFMD.Results:From 2017 to 2022, a total of 25 385 cases of HA were detected in children aged ≤6 years in Yinzhou, the male-to-female ratio of the cases was 1.12∶1. The average annual incidence of HA was 4 986.67/100 000, with the highest incidence in 2018 (10 477.09/100 000) and the lowest incidence in 2020 (870.88/100 000). The incidence peak of HA was during June to July. The incidence of HA was higher in age group 1 year (7 950.45/100 000) than in other age groups. The incidences of HA in Yunlong, Jiangshan and Xiaying were higher, with the incidence of 8 764.31/100 000, 8 377.58/100 000 and 7 965.31/100 000, respectively. The correlation coefficients between the incidence of HA and HFMD at lag day 0, 7, 12 and 18 were 0.199, 0.139, 0.090 and 0.086, respectively (all P<0.05). Conclusions:From 2017 to 2022, the incidence of HA was high in children aged ≤6 years in Yinzhou with obvious seasonality and area difference. The incidence of HA was correlated with the incidence of HFMD and the incidence of HFMD had certain lags. The comprehensive prevention and control of HA and HFMD should be further strengthened by prioritizing HA surveillance and implementing integrated surveillance and management of HA and HFMD.