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Objective: To systematically review the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children., Methods: RevMan5.3 was used to perform a Meta analysis of randomized controlled trials on the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children published between January 2008 and May 2018 across the world. A subgroup analysis was conducted according to the type of probiotics for intervention, follow-up time, time of probiotic supplementation, and study areas., Results: A total of 22 articles were selected, with 3 280 cases in the intervention group and 3 281 cases in the control group. The results of pooled effect size showed that probiotic supplementation during pregnancy and/or infancy significantly reduced the incidence rate of atopic dermatitis (RR=0.81, 95%CI: 0.70-0.93, P<0.05). According to the subgroup analysis, the intervention with Lactobacillus and Bifidobacterium had a significant effect (RR=0.68, 95%CI: 0.52-0.90, P<0.05); probiotic supplementation during both pregnancy and infancy also had a significant effect (RR=0.77, 95%CI: 0.66-0.90, P<0.05); probiotic supplementation during pregnancy and/or infancy had a better effect in preventing atopic dermatitis in children aged ≤2 years than in those aged >2 years (RR=0.74, 95%CI: 0.61-0.90, P<0.05); probiotic supplementation had a significant effect in Australia (RR=0.83, 95%CI: 0.73-0.96, P<0.05) and Europe/the United States (RR=0.74, 95%CI: 0.61-0.91, P<0.05). Heterogeneity was mainly due to follow-up time (I 2 =62.7%) and time of probiotic supplementation (I 2 =53.5%)., Conclusions: Probiotic supplementation during pregnancy and infancy helps to prevent atopic dermatitis in children, and mixed Lactobacillus-Bifidobacterium intervention has a better effect.

The diurnal variations in ozone concentrations in the summer were studied using the temperature, wind speed and direction, total cloud cover, and solar radiation intensity data collected in Langfang, China. The ratio of volatile organic compounds to nitrogen oxides (VOCs/NO x ) and the EKMA curve were studied to analyze the sensitivity of ozone formation. The results showed that:① The ozone generation rate and ozone concentrations were positively correlated with the solar radiation intensity with Pearson correlation coefficients of 0.61 and 0.48, respectively. Both the ozone generation rate and the solar radiation intensity reached their peak at about 12:00, while the ozone concentration reached its peak at about 16:00, which lagged behind the peak of the solar radiation intensity by 4 h. ② The correlation coefficient between the ozone generation rate and the temperature was 0.44, between the ozone concentration and temperature was 0.68. The ozone generation rate and ozone concentrations were inversely correlated with total cloud cover with correlation coefficients of -0.24 and -0.45, respectively. ③ The ozone concentrations in Langfang were high when the winds were from the west, south, or southeast. ④ The ozone concentrations in Langfang were more sensitive to VOCs than to NO x ; thus, they can be reduced efficiently by controlling the VOCs emissions.

In order to measure the dynamic wavelength of semiconductor lasers under current tuning, an improved method of fi- ber delay self-heterodyne interferometer was proposed. The measurement principle, as well the beat frequency and dynamic wavelength of recursive relations are theoretically analyzed. The application of the experimental system measured the dynamic wavelength characteristics of distributed feedback semiconductor laser and the static wavelength characteristics measurement by the spectrometer. The comparison between the two values indicates that both dynamic and static wavelength characteristic with the current tuning are the similar non-linear curve. In 20-100 mA current tuning range, the difference of them is less than 0.002 nm. At the same time, according to the absorption lines of CO2 gas, and HITRAN spectrum library, we can identify the dynamic wavelength of the laser. Comparing it with dynamic wavelength calculated by the beat signal, the difference is only 0.001 nm, which verifies the reliability of the experimental system to measure the dynamic wavelength.

Objective: The aim of the study reported here was to identify whether a stem cell biomarker, Lin28, may predict the pathologic tumor response to neoadjuvant chemotherapy for patients with locally advanced gastric cancer., Methods: The study enrolled 47 patients with gastric cancer who underwent neoadjuvant chemotherapy followed by surgery between July 2004 and March 2012. Cancer tissue was biopsied by gastroscopy and Lin28 expression in the tissue was measured by immunohistochemistry. Statistical analyses were performed to identify the relationship between Lin28 expression and tumor regression grade., Results: Of the 47 cases, pathologic nonresponse was observed in 29 (61.7%) and pathologic response in 18 (38.3%). Receiver-operating characteristic curve analysis showed that the histoscore of Lin28 expression with 0.325 as a cutoff value could differentiate between pathologic response and nonresponse. Multivariable analysis showed that Lin28 expression was an independent predictive factor for pathologic response to neoadjuvant chemotherapy (P = 0.006)., Conclusion: Lin28 expression was associated with pathologic tumor response in locally advanced gastric cancer patients undergoing neoadjuvant chemotherapy. This may suggest that Lin28 can serve as a predictive biomarker for neoadjuvant chemotherapy in patients with gastric cancer.