Objective: To investigate the nutritional status and its influencing factors among primary and middle school students in Yunfu City, Guangdong Province, so as to provide the basis for improving nutrition and health strategies for students. Methods: Primary and middle school students from 26 schools in 5 counties (cities, districts) of Yunfu City were selected in 2022 through multi-stage stratified cluster random sampling method. Demographic information, dietary and exercise behaviors were collected using questionnaire surveys, and the prevalence of malnutrition were analyzed. Factors affecting malnutrition was evaluated using a multinomial logistic regression model. Results: A total of 7 213 students were surveyed, including 3 881 boys (53.81%) and 3 332 girls (46.19%), and had a median age of 13.50 (interquartile range, 4.00) years. There were 2 667 primary school students (36.97%), 2 662 middle school students (36.91%) and 1 884 high school students (26.12%). There were 1 938 students suffered from malnutrition, with a detection rate of 26.87%. The detection rates for undernutrition, overweight and obesity were 11.66%, 9.75% and 5.46%, respectively. Multinomial logistic regression analysis showed that gender (boy, OR=2.227, 95%CI: 1.905-2.603), studying phase (primary school, OR=1.528, 95%CI: 1.239-1.884), ≥60 min/d of moderate/high-intensity exercise (0-1 d/week, OR=1.422, 95%CI: 1.153-1.753; 2-4 d/week, OR=1.280, 95%CI: 1.047-1.564) and frequency of having physical education (1-2 classes/week, OR=1.732, 95%CI: 1.084-2.767; 3-4 classes/week, OR=1.662, 95%CI: 1.026-2.693) were the influencing factors for undernutrition; gender (boy, OR=1.956, 95%CI: 1.656-2.311), frequency of sugary beverage intake (0 time/d, OR=0.721, 95%CI: 0.528-0.984) and frequency of having physical education (0 class/week, OR=2.087, 95%CI: 1.151-3.784; 1-2 classes/week, OR=1.644, 95%CI: 1.044-2.590; 3-4 classes/week, OR=1.685, 95%CI: 1.051-2.703) were the influencing factors for overweight; gender (boy, OR=2.459, 95%CI: 1.964-3.078) was the influencing factor for obesity among students. Conclusions Undernutrition, overweight and obesity coexist in primary and middle school students in Yunfu City. Gender, school phase, frequency of sugary beverage intake and frequency of having physical education are associated with malnutrition among primary and middle school students.

Maxillary first molar demonstrates considerable anatomic complexities and abnormalities with respect to the number of roots and root canals. The occurrence of maxillary first molar with a single buccal root is rarely reported in literature. This is a case report of maxillary first molar with a single buccal root and a palatal root,each of which has one canal.

Clinical application of doxorubicin (DOX) is heavily hindered by DOX cardiotoxicity. Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response (DDR), although the mechanism(s) involved remains to be elucidated. This study evaluated the potential role of TBC domain family member 15 (TBC1D15) in DOX cardiotoxicity. Tamoxifen-induced cardiac-specific Tbc1d15 knockout (Tbc1d15^CKO) or Tbc1d15 knockin (Tbc1d15^CKI) male mice were challenged with a single dose of DOX prior to cardiac assessment 1 week or 4 weeks following DOX challenge. Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbc1d15 were used for Tbc1d15 overexpression or knockdown in isolated primary mouse cardiomyocytes. Our results revealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality, the effects of which were ameliorated and accentuated by Tbc1d15 deletion and Tbc1d15 overexpression, respectively. DOX overtly evoked apoptotic cell death, the effect of which was alleviated and exacerbated by Tbc1d15 knockout and overexpression, respectively. Meanwhile, DOX provoked mitochondrial membrane potential collapse, oxidative stress and DNA damage, the effects of which were mitigated and exacerbated by Tbc1d15 knockdown and overexpression, respectively. Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit (DNA-PKcs). Liquid chromatography-tandem mass spectrometry and co-immunoprecipitation denoted an interaction between TBC1D15 and DNA-PKcs at the segment 594-624 of TBC1D15. Moreover, overexpression of TBC1D15 mutant (∆594-624, deletion of segment 594-624) failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs, DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type. However, Tbc1d15 deletion ameliorated DOX-induced cardiomyocyte contractile anomalies, apoptosis, mitochondrial anomalies, DNA damage and cytosolic DNA-PKcs accumulation, which were canceled off by DNA-PKcs inhibition or ATM activation. Taken together, our findings denoted a pivotal role for TBC1D15 in DOX-induced DNA damage, mitochondrial injury, and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention, a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.