Interactive effects of mercury and arsenic on their uptake, speciation and toxicity in rice seedling.

Rice can take up and translocate more As and Hg than other cereal crops. A hydroponic experiment was conducted to investigate their interactive effects on their uptake and toxicity in rice seedling after exposing to As(III) (0.1, 0.5 or 2.5 mg L−1) and Hg (0.05, 0.25 or 1.25 mg L−1) for 14 d. Rice was much more effective in taking up Hg than As and sequestered both in the roots. As and Hg reached 339 and 433 mg kg−1 in the roots, and 48.5 and 16.1 mg kg−1 in the shoots at As2.5 + Hg1.25. Though Hg inhibited As uptake and translocation, it enhanced As(III) toxicity to rice seedling. However, As inhibited Hg uptake at Hg0.05, but the opposite was observed at Hg0.25 and Hg1.25. Arsenite (54­100%) and inorganic Hg (100%) were the predominant form in the plant based on speciation analysis via HPLC­ICP­MS. Malondialdehyde in the roots and shoots increased with increasing As and Hg concentrations, with the highest being 54 µmol g−1 at As0.5 + Hg1.25 in the roots. Root cell structural damage and organelles number reduction with increasing As and Hg concentration were observed based on TEM. As and Hg transformation and toxicity can help to understand the metabolic mechanisms of As and Hg in rice plant when co-present.

[A cross-sectional study on the current status of female infertility in three counties of Xinjiang Uygur Autonomous Region].

OBJECTIVE: To explore the distribution and factors associated with female infertility in 3 areas in Xinjiang Uygur Autonomous Region so as to provide rationales for the prevention, diagnosis and treatment of infertility. METHODS: A total of 1895 women of reproductive age were enrolled with a cluster random stratified sampling method. A questionnaire survey and pelvic examinations were conducted. The collected data were statistically analyzed. RESULTS: The prevalence of infertility in these three areas ranged from 7.5% (76/1014) to 26.2% (144/550) with an average of 15.2% (279/1835). The prevalence of infertility was the highest in Shan shan and it was related with its unique geographical environment and life style. The lower levels of education and income, the higher prevalence of infertility. The occurrence of infertility was also correlated with their residence, premarital sex, body mass index and some concurrent diseases. CONCLUSION: It is necessary to carry out further studies on healthful life styles and those factors associated with the morbidity of infertility. The prevalence of infertility may be reduced and local reproductive health improved by avoiding or reducing the adolescent premarital sex and unmarried abortion.

[Effects of intercropping Sedum plumbizincicola in wheat growth season under wheat-rice rotation on the crops growth and their heavy metals uptake from different soil types].

A pot experiment with heavy metals- contaminated black soil from Heilongjiang Province, alluvial soil from Henan Province, and paddy soil from Zhejiang Province was conducted to study the effects of intercropping Sedum plumbizincicola in wheat growth season under wheat (Triticum aestivum) - rice (Oryza sativa) rotation on the growth of the crops and their heavy metals uptake, aimed to explore the feasibility of simultaneous grain production and heavy metals-contaminated soil phytoremediation in main food crop production areas of this country. Comparing with monoculture T. aestivum, intercropping S. plumbizincicola increased the soil NaNO3 -extractable Zn and Cd significantly, with the increment of extractable Zn in test paddy soil, alluvial soil, and black soil being 55%, 32% and 110%, and that of extractable Cd in test paddy soil and black soil being 38% and 110%, respectively. The heavy metals concentration in T. aestivum shoots under intercropping S. plumbizincicola was 0.1-0.9 times higher than that under monoculture T. aestivum, but the intercropping had little effects on the rice growth and its heavy metals uptake. Though the Cd concentration in rice grain after S. plumbizincicola planting was still higher than 0.2 mg kg(-1) (the limit of Cd in food standard), it presented a decreasing trend, as compared with that after monoculture T. aestivum. Therefore, intercropping S. plumbizincicola in wheat growth season under wheat-rice rota- tion could benefit the phytoremediation of heavy metals-contaminated soil, and decrease the food-chain risk of rotated rice.