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26 results on '"Guo, Doudou"'

6. Interaction between Vitamin D homeostasis, gut microbiota, and central precocious puberty.

Author

Guo, Doudou, Ning, Xin, Bai, Tao, Tan, Lingfang, Zhou, Yanfen, Guo, Zhichen, and Li, Xin

Abstract

Central precocious puberty (CPP) is an endocrine disease in children, characterized by rapid genital development and secondary sexual characteristics before the age of eight in girls and nine in boys. The premature activation of the hypothalamic-pituitary-gonadal axis (HPGA) limits the height of patients in adulthood and is associated with a higher risk of breast cancer. How to prevent and improve the prognosis of CPP is an important problem. Vitamin D receptor (VDR) is widely expressed in the reproductive system, participates in the synthesis and function of regulatory sex hormones, and affects the development and function of gonads. In addition, gut microbiota plays an important role in human health by mainly regulating metabolites, energy homeostasis, and hormone regulation. This review aims to clarify the effect of vitamin D deficiency on the occurrence and development of CPP and explore the role of gut microbiota in it. Although evidence on the interaction between vitamin D deficiency, gut microbiota, and sexual development remains limited, vitamin D supplementation and gut microbiota interventions offer a promising, non-invasive strategy for managing CPP. [ABSTRACT FROM AUTHOR]

Published
2024
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23. Estimation of Remote Sensing and Analysis of Temporal and Spatial Distribution of Grassland LAI

Author

Sun, Chengming, Liu, Tao, Guo, Doudou, Tian, Ting, Wang, Lijian, Chen, Yingying, and Li, Jianlong

Subjects
Estimation model, Grassland LAI, MODIS, NDVI, Temporal and spatial characteristics, Agribusiness
Abstract

To estimate the leaf area index (LAI) in large areas, this paper analyzes the relationships between normalized difference vegetation index (NDVI) and the grassland LAI based on MODIS data in the southern grassy mountains and slopes of China. By using nonlinear fitting equation we constructed the basic estimation model of grassland LAI with NDVI as the independent variable and introduced precipitation and temperature as regulatory factors. The model was validated with observed data in different years and the results showed that there was a good correlation between the simulated and observed LAI value with a statistically significant level of R2. RMSE was 0.302 and RRMSE was 0.154. It was also found that the spatial distribution of grassland LAI in south China showed a remarkable zonal characterization, and temporal distribution showed a single peak curve. These results provided a theoretical basis for the effective management of southern grassland resources and the carbon sink estimation of the nationwide grasslands.

Published
2013

25. Effects of free-air CO2enrichment on adventitious root development of rice under low and normal soil nitrogen levels

Author

Sun, Chengming, Wang, Lijian, Liu, Tao, Guo, Doudou, Chen, Yingying, Wu, Wei, Wang, Yulong, and Zhu, Jianguo

Abstract

Free air CO2enrichment (FACE) and nitrogen (N) have marked effects on rice root growth, and numerical simulation can explain these effects. To further define the effects of FACE on root growth of rice, an experiment was performed, using the hybrid indica cultivar Xianyou 63. The effects of increasing atmospheric CO2concentration [CO2], 200μmolmol−1higher than ambient, on the growth of rice adventitious roots were evaluated, with two levels of N: low (LN, 125kgha−1) and normal (NN, 250kgha−1). The results showed a significant increase in both adventitious root number (ARN) and adventitious root length (ARL) under FACE treatment. The application of nitrogen also increased ARN and ARL, but these increases were smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root number and length were constructed with time as the driving factor. The models illustrated the dynamic development of rice adventitious root number and length after transplanting, regulated either by atmospheric [CO2] or by N application. The simulation result was supported by statistical tests comparing experimental data from different years, and the model yields realistic predictions of root growth. These results suggest that the models have strong predictive potential under conditions of atmospheric [CO2] rises in the future.

Published
2014
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26. Electrocatalytic degradation of bisphenol A in water on a Ti-based PbO2–ionic liquids (ILs) electrode

Author

Ju, Peng, Fan, Hai, Guo, Doudou, Meng, Xiaomeng, Xu, Minrong, and Ai, Shiyun

Subjects
*ELECTROCATALYSIS, *BISPHENOL A, *TITANIUM, *IONIC liquids, *LEAD oxides, *ELECTRODES, *ELECTRIC conductivity, *HIGH performance liquid chromatography
Abstract

Abstract: This study presents an electrocatalytic method for the degradation of bisphenol A (BPA) in water based on a novel Ti-based PbO2–ionic liquids (ILs) electrode. The electrode showed a high stability and reusability due to the better electroconductivity and reusability of ILs. Besides, the influence factors on BPA degradation were investigated in detail, and under the optimal conditions the degradation efficiency of BPA could reach 100% within 150min. What''s more, over 75% chemical oxygen demand (COD) removal was achieved on PbO2–ILs(10%)/Ti electrode. The mechanism of the degradation reaction was proposed based on the results of high performance liquid chromatography coupled with mass spectrometry (LC/MS). It was deduced that hydroxyl radicals (ated in the electrocatalytic process played a key role in oxidizing BPA to form CO2 and H2O, which could be determined by fluorescence methods. All these results illustrated that PbO2–ILs/Ti electrode was effective for pollutants degradation and had a great potential application. [Copyright &y& Elsevier]

Published
2012
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