Selenium nanoparticles stabilized by Sargassum fusiforme polysaccharides: Synthesis, characterization and bioactivity.

Selenium nanoparticles (SeNPs) are a potential tumor therapeutic drug and have attracted widespread attention due to their high bioavailability and significant anticancer activity. However, the poor water solubility and degradability of selenium nanoparticles severely limit their application. In this study, spherical selenium nanoparticles with a particle size of approximately 50 nm were prepared by using Sargassum fusiforme polysaccharide (SFPS) as a modifier and Tween-80 as a stabilizer. The results of in vitro experiments showed that Sargassum fusiforme polysaccharide-Tween-80-Selenium nanoparticles (SFPS-Tw-SeNPs) had a significant inhibitory effect on A549 cells, with an IC50 value of 6.14 µg/mL, and showed antitumor cell migration and invasion ability against A549 cells in scratch assays and cell migration and invasion assays (transwell assays). Western blot experiments showed that SFPS-Tw-SeNPs could inhibit the expression of tumor migration- and invasion-related proteins. These results suggest that SFPS-Tw-SeNPs may be potential tumor therapeutic agents, especially for the treatment of human lung cancer.

The association between myopia with overweight and obesity in middle school students in Zhengzhou / 中国学校卫生

Objective@#To understand associated factors of myopia among middle school students in Zhengzhou and to explore the correlation between myopia with overweight and obesity, to provide a scientific basis for myopia prevention.@*Methods@#A total of 3 297 middle school students from 8 middle schools in Erqi District, Zhongmu County and Xingyang County of Zhengzhou City were selected by a cluster random sampling method to participate in vision testing and questionnaire survey. Chi square test, and Logistic regression analysis were used.@*Results@#Overall prevalence of myopia of middle school students was 80.5%, overweight 14.7%, obesity 10.1% in Zhengzhou. The prevalence of myopia differed significantly by schooling stage, parental myopia status and sex ( χ 2= 18.34, 23.55, 8.98, 26.53, 27.46, 47.25, P <0.05). Significant differences in myopia detection rate by after school homework duration were observed in boys and the entire population( χ 2=12.40, 15.25, P <0.01), and significant differences in myopia detection rate by body mass index (BMI) were only observed in boys ( χ 2=6.32, P <0.05). The distribution of myopia severity was statistically significant by sex among junior school students, and by BMI categories among high school students ( χ 2=22.71, 20.37, P <0.01). Multivariate binary Logistic regression analysis showed that the risk for myopia among school students who were overweight and obese was 1.81 times higher than that of students who were not overweight and obese( P <0.01).@*Conclusion@#Overweight and obesity might increase the risk of myopia among middle school students, targeted measures should be taken to maintain the healthy weight of middle school students and reduce the risk of myopia.

Influence of Laser Energy Input and Shielding Gas Flow on Evaporation Fume during Laser Powder Bed Fusion of Zn Metal.

Laser powder bed fusion (LPBF) of Zn-based metals exhibits prominent advantages to produce customized biodegradable implants. However, massive evaporation occurs during laser melting of Zn so that it becomes a critical issue to modulate laser energy input and gas shielding conditions to eliminate the negative effect of evaporation fume during the LPBF process. In this research, two numerical models were established to simulate the interaction between the scanning laser and Zn metal as well as the interaction between the shielding gas flow and the evaporation fume, respectively. The first model predicted the evaporation rate under different laser energy input by taking the effect of evaporation on the conservation of energy, momentum, and mass into consideration. With the evaporation rate as the input, the second model predicted the elimination effect of evaporation fume under different conditions of shielding gas flow by taking the effect of the gas circulation system including geometrical design and flow rate. In the case involving an adequate laser energy input and an optimized shielding gas flow, the evaporation fume was efficiently removed from the processing chamber during the LPBF process. Furthermore, the influence of evaporation on surface quality densification was discussed by comparing LPBF of pure Zn and a Titanium alloy. The established numerical analysis not only helps to find the adequate laser energy input and the optimized shielding gas flow for the LPBF of Zn based metal, but is also beneficial to understand the influence of evaporation on the LPBF process.

Analysis of teaching environment of primary and middle schools in Zhengzhou City from 2014 to 2018 / 中国学校卫生

Objective@#To understand the changing trend of the teaching environment of the elementary and secondary schools in Zhengzhou, and to provide data for further improving the teaching environment of the elementary and secondary schools.@*Methods@#A survey of teaching facilities and teaching aids in 534 secondary and primary schools in Zhengzhou was conducted from 2014 to 2018 by using a stratified random sampling method.@*Results@#Teaching facilities: the qualified rate of the railings in the outer corridor of the teaching building was 88.8% (474), the qualified rate of classroom lighting was 79.6% (425), the qualified rate of the light desk distance was 82.8% (442), and the qualified rate of black plate lights 86.1% (460), the qualified rate of each year was statistically significant ( χ 2=9.97, 23.74, 80.10, 53.33, P <0.05); the qualified rate of classroom area per capita was 52.8% (282), the qualified rate of the outer corridor width of the teaching building was 64.0% (342), the qualified rate of each year showed no statistical difference( χ 2=7.38, 8.71, P >0.05). Teaching ancillary facilities: the proportion of centralized water supply was 65.0% (347), toilet with hand washing facilities was 81.6% (436), these two indicators showed an increasing trend, hand washing facilities in campus was 70.6% (377), showed a decreasing trend, the rate of each year differed significantly( χ 2=88.62, 42.71 , 123.53, P <0.05).@*Conclusion@#The overall situation of teaching environment in Zhengzhou primary and secondary schools is relatively good, the qualified rate of most indicators of teaching facilities increased from 2014 to 2018. However, there are still some indicators to be strengthened.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer.

BACKGROUND: There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC. METHODS: We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9). RESULTS: The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients. CONCLUSIONS: Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Osteogenesis and mineralization in a rabbit mandibular distraction osteogenesis model is promoted by the human LMP-1 gene.

To observe the effects of LIM mineralization protein-1 (LMP-1) on bone regeneration in the distraction zone based on gene transduction, 36 New Zealand white rabbits underwent mandibular lengthening with a distraction rate of 2 mm/day. The animals were then randomly divided into group A and group B (n = 18, each). At the end of the distraction, Ad5-EGFP viruses and Ad5-LMP-1/EGFP viruses were injected into the distraction gaps in groups A and B, respectively. Seven days later, five randomly selected animals from each group were sacrificed to evaluate the survival of the virus. Four and 8 weeks after distraction osteogenesis (DO), six samples randomly selected from each group underwent CT scanning and dual energy X-ray absorptiometry detection. Eight weeks after DO, the rabbits were sacrificed, and the distracted mandibles were harvested. Six animals from each group processed for radiography, micro-CT, histology, and the rest samples were taken three-point bend testing. Using this model, better bone formation and mineralization in the distracted callus were observed in group B when compared with those in group A. The results suggest local transduction with LMP-1 gene promotes osteogenesis and mineralization in DO.

GYY4137 promotes bone formation in a rabbit distraction osteogenesis model: a preliminary report.

PURPOSE: Hydrogen sulfide (H2S) has been shown to enhance bone formation, but its osteogenic effect is unclarified during distraction osteogenesis (DO). This study tested the hypothesis that H2S could promote bone formation in a rabbit mandibular DO model. MATERIALS AND METHODS: Unilateral mandibular lengthening was achieved in 26 rabbits. During the distraction and the first week of consolidation, saline 0.2 mL or saline 0.2 mL and GYY4137 (H2S donor, 50 mg/kg) was injected intravenously twice a day. Distracted mandibles were examined by dual-energy x-ray absorptiometry, histology, computed tomography, and a 3-point bending test 8 weeks after distraction. RESULTS: The GYY4137-treated animals presented a greater response as measured by bone mineral density and mechanical properties and a more mature microstructure of the lengthened mandibles compared with the saline-treated control animals. CONCLUSION: The results of this study suggest that H2S can accelerate osteogenesis during DO.