ABSTRACT
The paleoenvironment of Jixian carbonate rocks in the Mesoproterozoic Ordos Basin is studied by carbon and oxygen isotope analyses, diagenetic environment analysis, and the restoration of paleosalinity and paleotemperature. The results indicate that the carbonate rocks of the Jixian System have always been in a near-surface environment and have not been deeply buried. The ranges of variation in δ13CPDB and δ18OPDB are relatively narrow, ranging from - 5.75 to 1.41 and - 8.88 to - 4.01, respectively, which is consistent with the stable tidal flat sedimentary environment during the Mesoproterozoic in the study area. The paleosalinity (Z) values range from 111.7 to 127.1, and the paleotemperature (T) values range from 32.7 to 57.33 °C, indicating a relatively warm paleoclimatic environment during the Mesoproterozoic era in the study area. The analysis shows that in a warm paleoclimatic environment, although carbon and oxygen isotopes, Z, and T have certain fluctuations, their ranges are relatively small, reflecting to some extent the stable tectonic environment of the study area during the Mesoproterozoic era. Comprehensive research shows that the Ordos Basin had a warm climate and a stable tectonic environment in the Mesoproterozoic, which may be a good response to the North China Block's position near the equator and continuous thermal subsidence in the Mesoproterozoic.
ABSTRACT
Objective:To evaluate the effect of prevention and control measures to drinking-water-borne endemic fluorosis in Qingdao, and to provide scientific basis for formulating prevention and control strategies.Methods:From 2019 to 2021, a full coverage surveillance was carried out in 1 146 villages in 7 drinking-water-borne endemic fluorosis areas in Qingdao, including the operation status of the water improvement and fluoride reduction project, the water fluoride content in the villages, and the prevalence of dental fluorosis among children aged 8-12 years.Results:From 2019 to 2021, all the 1 146 affected villages in Qingdao had improved their water supply, and the rates of water fluoride exceeding the standard were 7.16% (82/1 146), 1.40% (16/1 146) and 3.84% (44/1 146), respectively, and the differences between years were statistically significant (χ 2 = 48.36, P < 0.001). The detection rates of dental fluorosis in children aged 8-12 years were 3.11% (803/25 856), 2.68% (629/23 460) and 3.00% (655/21 846), respectively, and the differences between years were statistically significant (χ 2 = 8.26, P = 0.016). The detection rate of dental fluorosis among children in villages with qualified water fluoride (2.85%, 1 986/69 565) was lower than that in villages with excessive water fluoride (6.32%, 101/1 597), with a statistically significant difference (χ 2 = 67.74, P < 0.001). Conclusions:From 2019 to 2021, the effect of prevention and control measures to drinking-water-borne endemic fluorosis in Qingdao is significant and the detection rate of dental fluorosis in children is low, the detection rate of dental fluorosis in villages with qualified water fluoride is significantly lower than that in villages with excessive water fluoride. In the future, we should continue to strengthen water fluoride monitoring and engineering maintenance to ensure that the water fluoride content continues to be qualified and effectively reduce the harm of fluorosis.
ABSTRACT
Objective To study the concentration of plasma total homocysteine(tHcy) in patients with chronic renal failure(CRF).Methods 105 chronic renal failure patients and 35 health individuals to our hospital were chosen to measure the level of tHcy using enzymatic cycling assay method.Results The mean level of tHcy in renal failure period C RF patients was significantly higher than that in normal controls (t =3.12,P ＜ 0.05),and the level of plasma tHcy was significantly higher in Uremia stage than in renal failure period in CRF patients (t =6.41,P ＜0.05),and the level of plasma tHcy was significantly higher in renal failure period than in renal function decompensated period in CRF patients (t =11.27,P ＜ 0.05).Conclusion The level of plasma tHcy were significantly elevated in patients with CRF,and there is a trend that the level of plasma tHcy increases with severity of CRF.Serum tHcy concentration have significant value in the diagnosis and understanding the condition of patients with CRF.
