Objective: To explore the association of physical activity and sugar sweetened beverage consumption with psychological sub health among middle school students in Bao an District, Shenzhen, so as to provide a reference for adolescent mental health promotion. Methods: A questionnaire survey was conducted in November 2024 by a stratified cluster random sampling method to select 6 926 junior and senior middle school students from 5 middle schools in Shenzhen. The questionnaire from Youth Risk Behavior Surveillance System was used to assess the consumption of sugar sweetened beverages, and physical activity Rating Scale was used to assess the level of physical activity, and Brief Instrument on Psychological Health of Youths was used to evaluate the psychological sub health status. The Chi -square test was used to analyze the differences in the detection rates of psychological sub health among different groups of middle school students, and a multivariate Logistic regression model was established to analyze the effects of physical activity and sugar sweetened beverage consumption and their combined effects on the psychological sub health of middle school students. Results: The detection rate of psychological sub health among middle school students in Bao an District, Shenzhen was 18.93%. Multivariate Logistic regression analysis showed that, after controlling for confounding factors such as gender, school stage, family residence, family economic status, parental literacy, academic stress and number of friends, lack of physical activity or excessive sugar sweetened beverage consumption were associated with increased risks of psychological sub health among middle school students ( OR =1.36, 1.45); and the highest risk of psychological sub health was found in middle school students who were lack of physical activity and excessive sugar sweetened beverage consumption ( OR =2.59) ( P <0.01). Further analysis by school stages showed that junior high school students with sufficient physical activity and excessive intake of sugary drinks ( ROR =2.10), lack of physical activity and excessive intake of sugary drinks ( ROR =2.31) were at higher risks of psychological sub health than senior high school students( P <0.05). Conclusions Insufficient physical activity and excessive sugar sweetened beverage consumption are closely associated with an increased risk of psychological sub health among middle school students. Effective interventions should be targeted to reduce the risk of psychological sub health problems among middle school students.

OBJECTIVES: This study aims to use 3D prin-ting technology based on the principle of stereo lithography apparatus (SLA) to shape dental lithium disilicate ceramics and study the effects of different slurry proportions on the microstructure and properties of heat-treated samples. METHODS: The experimental group comprised lithium disilicate ceramics manufactured through SLA 3D printing, and the control group comprised lithium disilicate ceramics (IPS e.max CAD) fabricated through commercial milling. An array of different particle sizes of lithium disilicate ceramic powder materials (nano and micron) was selected for mixing with photocurable acrylate resin. The proportion of experimental raw materials was adjusted to prepare five groups of ceramic slurries for 3D printing (Groups S1-S5) on the basis of rheological properties, stability, and other factors. Printing, debonding, and sintering were conducted on the experimental group with the optimal ratio, followed by measurements of microstructure, crystallographic information, shrinkage, and mechanical properties. RESULTS: Five groups of lithium disilicate ceramic slurries were prepared, of which two groups with high solid content (75%) (Groups S2 and S3) were selected for 3D printing. X-ray diffraction and scanning electron microscopy results showed that lithium disilicate was the main crystalline phase in Groups S2 and S3, and its microstructure was slender, uniform, and compact. The average grain sizes of Groups S2 and S3 were (559.79±84.58) nm and (388.26±61.49) nm, respectively (P<0.05). Energy spectroscopy revealed that the samples in the two groups contained a high proportion of Si and O elements. After heat treatment, the shrinkage rate of the two groups of ceramic samples was 18.00%-20.71%. Test results revealed no statistical difference in all mechanical properties between Groups S2 and S3 (P>0.05). The flexural strengths of Groups S2 and S3 were (231.79±21.71) MPa and (214.86±46.64) MPa, respectively, which were lower than that of the IPS e.max CAD group (P<0.05). The elasticity modulus of Groups S2 and S3 were (87.40±12.99) GPa and (92.87±19.76) GPa, respectively, which did not significantly differ from that of the IPS e.max CAD group (P>0.05). The Vickers hardness values of Groups S2 and S3 were (6.53±0.19) GPa and (6.25±0.12) GPa, respectively, which were higher than that of the IPS e.max CAD group (P<0.05). The fracture toughness values of Groups S2 and S3 were (1.57±0.28) MPa·m^0.5 and (1.38±0.17) MPa·m^0.5, respectively, which did not significantly differ from that of the IPS e.max CAD group (P>0.05). CONCLUSIONS The combination of lithium disilicate ceramic powders with different particle sizes can yield a slurry with high solid content (75%) and suitable viscosity and stability. The dental lithium disilicate ceramic material is successfully prepared by using 3D printing technology. The 3D-printed samples show a small shrinkage rate after heat treatment. Their microstructure conforms to the crystal phase of lithium disilicate ceramics, and their mechanical properties are close to those of milled lithium disilicate ceramics.
Printing, Three-Dimensional ; Dental Porcelain/chemistry* ; Ceramics/chemistry* ; Materials Testing ; Particle Size

Objective: To investigate the effect of hirsutine combined with oxaliplatin on the antitumor activity of HGC-27 mice with gastric cancer. Methods: Gastric cancer HGC-27 tumor-bearing mice model was established. The successfully established tumor-bearing mice were randomly divided into normal control group, model group, oxaliplatin group(10 mg/kg), hirsutine group(10 mg/kg) and combination group(10 mg/kg hirsutine + oxaliplatin 10 mg/kg). The intervention lasted for 2 weeks. The tumor growth of mice in each group was recorded, and the tumor inhibition rate, thymus index and spleen index were calculated. The proportion of CD4+T cells and CD8+T cell subsets in peripheral blood was detected by flow cytometry, and the CD4+/CD8+ratio was calculated. ELISA was used to measure the serum levels of interleukin(IL)-1β, IL-6 and tumor necrosis factor(TNF)-α. HE staining was used to observe the pathological changes in tumor tissues. Western blot was used to detect the protein expression levels of cleaved Caspase-3, Bcl-2 associated X protein(Bax), B-cell lymphoma-2(Bcl-2)and tumor proliferation antigen(Ki67), proliferating cell nuclear antigen(PCNA) in tumor tissues. Results: Compared with the control group, the spleen index, thymus index, CD4+T cell ratio and CD4+/CD8+ratio in peripheral blood of the model group decreased(P<0.05), while the proportion of CD8+T cells in peripheral blood and the levels of TNF-α, IL-1β and IL-6 in serum increased(P<0.05). Compared with the model group, the tumor growth in oxaliplatin group, hirsutine group and combined group was significantly inhibited, the volume of tumor cells decreased, the heteromorphism was smaller, and the nucleosomes decreased less. The inhibitory rate, spleen index, thymus index, CD4+T cell ratio and CD4+/CD8+ratio in peripheral blood of the model group increased(P<0.05), the proportion of CD8+T cells in peripheral blood and the levels of TNF-α, IL-1β and IL-6 in serum decreased(P<0.05), while the protein expression levels of Bcl-2, Ki67 and PCNA in tumor tissues decreased and the cleaved Caspase-3 and Bax levels increased(P<0.05). Among them, the combination group of rhynchophylline and oxaliplatin had the most obvious intervention effect. Conclusion Hirsutine can inhibit the proliferation of tumor cells in gastric cancer bearing mice and promote their apoptosis, and has a more significant effect when combined with oxaliplatin.