Abstract The prevention and control of myopia in Chinese children and adolescents has become a major public health issue. While maintaining increased outdoor activity as a cornerstone intervention, there is an urgent need to explore new complementary approaches that can be effectively implemented in both indoor and outdoor settings. In recent years, environmental spatial frequency has gained increasing attention as one of the key environmental factors influencing the development and progression of myopia. Both animal studies and human research have confirmed that indoor environments lacking mid to high spatial frequency components, often characterized as "visually impoverished", can promote axial elongation and myopia through mechanisms such as disruption of retinal neural signaling, impaired accommodative function, and altered expression of related molecules. Based on the scientific consensus, it is recommended that "enriching of environmental spatial frequency" should be integrated into the myopia prevention and control framework. Following the principles of schoolled organization, family cooperation, community involvement, and student participation, specific measures are put forward in three areas：optimizing school visual settings, improving home spatial environments, and promoting healthy visual behavior. The aim is to create "visually friendly" indoor environments as an important supplement to outdoor activity, thereby providing a novel perspective and strategy for comprehensively advancing myopia prevention and control among children and adolescents.

Objective:To analyze the adverse reactions of patients with multidrug-resistant pulmonary tuberculosis treated with linezolid, and to provide reference for clinical rational use of drugs.Methods:A total of 189 patients with multidrug-resistant pulmonary tuberculosis who were admitted to Hunan Chest Hospital between June 2019 and June 2020 were retrospectively included, and were divided into the linezolid group and the control group. The control group was given a standardized anti-tuberculosis treatment without linezolid, and the linezolid group was given linezolid in addition to standardized regimens. The occurrences of hematological toxicity, peripheral neuritis, optic neuritis and other adverse reactions in the two groups after anti-tuberculosis treatment were recorded. The risk factors for adverse reactions of linezolid were analyzed. Statistical analysis was performed using independent samples t test and chi-square test, and logistic regression was used to analyze the risk factors for adverse reactions of linezolid. Results:A total of 189 patients with MDR-TB were included in this study, including 108 in the linezolid group and 81 in the control group. There were no significant differences in baseline characteristics between the linezolid and control groups. The frequencies of leukopenia, anemia, thrombocytopenia, peripheral neuritis and optic neuritis in the linezolid group were 20.4%(22/108), 47.2%(51/108), 21.3%(23/108), 20.4%(22/108) and 13.9%(15/108), respectively, which were all significantly higher than those in the control group (8.6%(7/81), 27.2%(22/81), 9.9%(8/81), 1.2%(1/81) and 4.9%(4/81), respectively), and the differences were all statistically significant ( χ2=4.90, 7.86, 4.40, 15.86 and 4.10, respectively, all P<0.050). Patients older than 45 years of age was independent risk factor for leukopenia (odds ratio ( OR)=3.08, 95% confidence interval ( CI) 1.03 to 9.25, P<0.050) and thrombocytopenia ( OR=2.41, 95% CI 1.09 to 5.35, P<0.050) after linezolid administration. The higher value of white blood cell at baseline ( OR=0.48, 95% CI 0.30 to 0.76, P=0.002) was an independent protective factor for leukopenia associated with linezolid. Conclusions:Pancytopenia, peripheral neuritis and optic neuritis are prone to appear when linezolid is used to treat patients with multidrug-resistant pulmonary tuberculosis. In clinical practice, closely monitoring the adverse reactions during the use of linezolid for anti-tuberculosis treatment is needed.

Objective To construct a eukaryotic expression plasmid carrying human full-length Notch ligand Delta-like 3 (DLL3) gene and study the effect of DLL3 knockdown and overexpression on the proliferation of gastric cancer cells in vitro. Methods Human full-length DLL3 gene was amplified by PCR and cloned into the eukaryotic expression vector pCMV-Tag4. After verification by restriction enzymes and sequencing, the recombinant DLL3/pCMV-Tag4 vector was transiently transfected into HEK293T cells, in which the expressions of human DLL3 mRNA and protein were detected using real-time quantitative PCR and Western blotting, respectively. The expression of DLL3 in normal gastric epithelial cells and gastric cancer cell lines was detected by qRT-PCR and Western blotting. DLL3/pCMV-Tag4 was transfected into 3 gastric cancer cell lines, and their proliferation was assessed with MTT assay. Human gastric cancer cells MGC803 and MKN45 were also transfected with a specific human DLL3-siRNA to assess the effect of DLL3 down-expression on the cell proliferation. Results The recombinant eukaryotic expression vector DLL3/pCMV-Tag4 was successfully constructed and human full-length DLL3 was expressed in HEK293T cells. MTT assay showed that DLL3 over-expression obviously promoted the proliferation and down-regulation of DLL3 inhibited the proliferation of the gastric cancer cells. Conclusion DLL3 overexpression can promote the proliferation of gastric cancer cells in vitro, and down-regulation of DLL3 inhibits the proliferation of gastrc cancer cells,which provides a novel strategy for targeted thrapy of gastric cancer.

Objective To construct a eukaryotic expression plasmid carrying human full-length Notch ligand Delta-like 3 (DLL3) gene and study the effect of DLL3 knockdown and overexpression on the proliferation of gastric cancer cells in vitro. Methods Human full-length DLL3 gene was amplified by PCR and cloned into the eukaryotic expression vector pCMV-Tag4. After verification by restriction enzymes and sequencing, the recombinant DLL3/pCMV-Tag4 vector was transiently transfected into HEK293T cells, in which the expressions of human DLL3 mRNA and protein were detected using real-time quantitative PCR and Western blotting, respectively. The expression of DLL3 in normal gastric epithelial cells and gastric cancer cell lines was detected by qRT-PCR and Western blotting. DLL3/pCMV-Tag4 was transfected into 3 gastric cancer cell lines, and their proliferation was assessed with MTT assay. Human gastric cancer cells MGC803 and MKN45 were also transfected with a specific human DLL3-siRNA to assess the effect of DLL3 down-expression on the cell proliferation. Results The recombinant eukaryotic expression vector DLL3/pCMV-Tag4 was successfully constructed and human full-length DLL3 was expressed in HEK293T cells. MTT assay showed that DLL3 over-expression obviously promoted the proliferation and down-regulation of DLL3 inhibited the proliferation of the gastric cancer cells. Conclusion DLL3 overexpression can promote the proliferation of gastric cancer cells in vitro, and down-regulation of DLL3 inhibits the proliferation of gastrc cancer cells,which provides a novel strategy for targeted thrapy of gastric cancer.