Objective: To explore the effects of grandparent involvement in parenting on health related behaviors among urban preschool children, so as to provide a basis for the development of interventions for unhealthy behaviors among preschool children with different parenting pattern. Methods: A total of 5 431 preschool children aged 3-6 years old in Xinbei District, Changzhou City, were selected by census method during January to October, 2022. General household characteristics and health related behaviors of children were investigated by questionnaires, and the differences in health related behaviors with different parenting pattern involving grandparents were explored by the χ 2 test. A multifactorial Logistic regression model was used to analyze the effects of grandparenting on preschool children s health behaviors. Results: About 51.2% of preschoolers were raised by both parents, 46.1 % were co parented by grandparents, and 2.7% were raised by grandparents. After multifactorial Logistic regression analysis controlling for age, gender, annual household income, and family structure, children co parented by grandparents had a reduced risk of screen exposure time>1 h/d ( OR =0.79, P <0.05), with increased risks of outdoor activity time<2 h/d ( OR =1.30, P < 0.05 ), sleep duration <10 h/d ( OR =1.31, P <0.05), sleep difficulties ( OR =1.39, P <0.05) and adverse eating behaviors ( OR =1.20， P < 0.05), compared with children parented by both parents. Children raised by grandparents were at increased risk for outdoor activity time<2 h/d ( OR =2.19) and unhealthy eating behaviors ( OR =1.39) ( P <0.05). Conclusions Compared with children raised by both parents, the incidence of unhealthy behaviors is increased in children raised by parents and grandparents and in children raised by full grandparents. Active intervention should be focused on unhealthy behaviors of preschool children with pareting involving grandparents to promote the physical and mental health of preschool children.

Two strains of porcine reproductive and respiratory syndrome virus (PRRSV) were isolated in 2006 and 2016 and designated as FZ06A and FZ16A, respectively. Inoculation experiments showed that FZ06A caused 100% morbidity and 60% mortality, while FZ16A caused 100% morbidity without death. By using genomic sequence and phylogenetic analyses, close relationships between a Chinese highly pathogenic PRRSV strain and the FZ06A and FZ16A strains were observed. Based on the achieved results, multiple genomic variations in Nsp2, a unique N-glycosylation site (N³³→K³³), and a K151 amino acid (AA) substitution for virulence in the GP5 of FZ16A were detected; except the 30 AA deletion in the Nsp2-coding region. Inoculation experiments were conducted and weaker virulence of FZ16A than FZ06A was observed. Based on our results, a 30 AA deletion in the Nsp2-coding region is an unreliable genomic indicator of a high virulence PRRSV strain. The Nsp2 and GP5 differences, in addition to the virulence difference between these two highly pathogenic PRRSV strains, have the potential to be used to establish a basis for further study of PRRSV virulence determinants and to provide data useful in the development of vaccines against this economically devastating disease.
Asian Continental Ancestry Group ; China ; Genomics ; Humans ; Mortality ; Phylogeny ; Porcine Reproductive and Respiratory Syndrome ; Porcine respiratory and reproductive syndrome virus ; Vaccines ; Virulence

Objective: To explore the classification characteristics of medical students resilience, and psychological stress difference of each latent class. Methods: A total of 500 medical students from a medical university majoring in five-year clinical in Liaoning province were investigated by using the general questionnaire, the resilience scale and the Chinese college students stress scale. Results: Three latent classes model of resilience in medical students was supported, including "low tenacity group" (32.7%), "general resilience group" (32.1%) and "tenacity-strength group" (35.2%). In Logistic regression analysis, the proportion of students whose majors met their interests in the general resilience group (OR=3.796) and the tenacity-strength group (OR=7.556) was larger. There were significant differences in psychological stress scores between different latent classes (P<0.01). Conclusions Medical students′ resilience has obvious classification characteristics, and there were different distributions in different latent classes of whose majors meet their interests. Researchers and teachers should pay more attention to the students who have less resilience and whose majors are not in accordance with their own interests, develop their professional interest, and improve psychological stress through appropriate intervention methods.