[Research methods and progress on the reduction effects of vehicle emission pollutants by street canyon greening.] / è¡—è°·ç»¿åŒ–æ¶ˆå‡æœºåŠ¨è½¦æŽ’æ”¾æ±¡æŸ“ç‰©çš„ç ”ç©¶æ–¹æ³•ä¸Žè¿›å±•.

With the development of high-density and high-rise buildings on both sides of the street, widespread attention has been paid to the applicability of the traditional greening model of 'the more trees, the better atmospheric environment' in dealing with air pollution in urban street canyons. Clarifying the characteristics of street canyons greening and its planting design pattern on the reduction of emission pollutants by vehicles is an important prerequisite for the improvement of air quality in the street canyons. Based on literature review, we compared the applicability and limitations of the three methods, including field observation, wind tunnel test, and numerical simulation. We further analyzed the effects of roadside trees and hedges on the dispersion and deposition of air pollutants, and put forward a framework of adaptive greening design for air quality improvement. Finally, we proposed that future studies should address the creation of graphic languages for roadside greening design, the development of technical guidelines for evaluating the exposure of air pollution, and the optimization of parameterization schemes for the physical processes of greening effect in computational fluid dynamics models. Overall, our review could provide ideas and reference for the subsequent research.

Association of dietary intake of folate, vitamin B6 and B12 and MTHFR genotype with breast cancer risk.

AIM: We aimed to investigate the associations of dietary intake of folate, vitamin B6 and B12 and MTHFR genotype with breast cancer in a Chinese population. METHODS: A matched case-control study was conducted, and 435 patients with newly diagnosed and histologically confirmed breast cancer and 435 controls were collected. The folate intake, vitamin B6 and vitamin B12 were calculated, and MTHFR C665T, C677T and A1298C were analyzed by PCR-RFLP. RESULTS: We found vitamin B12 was likely to reduce the risk of breast cancer, and MTHFR 665TT was associated with increased risk of breast cancer. Folate intake, vitamin B12 intake and variants of MTHFR C677T and MTHFR A1298C demonstrated no association with risk of breast cancer. However, we found patients with low intake of vitamin B6 and MTHFR 665TT genotype had a higher risk of breast cancer (OR=1.87, 95% CI=1.29-2.77), the association being less pronounced among subjects with a moderate intake of vitamin B6 and MTHFR 665TT genotype (OR=1.58, 95% CI=1.03-2.49, P=0.03). CONCLUSION: Our study indicated that the MTHFR C665T polymorphism and vitamin B6 are associated with risk of breast cancer, which indicated roles for nutrients in developing breast cancer.