Objective:To investigate the distribution of iodine and other chemical elements in soil, grain and vegetables in different water iodine areas of Xi'an City, and to provide theoretical basis for prevention and treatment of iodine related diseases and water improvement measures.Methods:From September to November 2021, a stratified cluster sampling method was used to select three survey villages in Xi'an, namely Yehu Village, Xingbei Village, and Quanzhong Village, where the iodine level of residents' drinking water < 10, 10 - 100, and > 100 μg/L. Drinking water samples were collected from seven survey sites based on the source of domestic drinking water to determine the iodine level of the water. At the same time, soil samples of cultivated land, residents' grains (wheat, corn), and vegetables were collected from survey villages to determine the content of 14 elements including calcium, iron, magnesium, chromium, nickel, copper, zinc, cadmium, lead, arsenic, mercury, selenium, iodine, and fluoride.Results:The iodine level in the water of 7 survey sites in three survey villages was 5.80, 6.40, 25.51, 42.20, 53.90, 111.65, and 177.63 μg/L, respectively. A total of 70 samples of soil, 65 samples of wheat, 76 samples of corn, and 141 samples of vegetables were collected. Among them, the levels of various elements in vegetables and grains were lower than those in the soil. Only calcium and fluoride were higher in vegetables than in grains, while iron, chromium, copper, zinc, selenium, and iodine were lower in vegetables than in grains. According to the range of water iodine level, there were statistically significant differences in the content of calcium, iron, chromium, nickel, copper, zinc, mercury, iodine, and fluoride in soils from different water iodine regions ( Fcalcium, iron, chromium, nickel = 42.04, 13.55, 12.22, 11.20, Hcopper, zinc, mercury, iodine, fluoride = 14.27, 9.19, 14.72, 25.14, 16.50, P < 0.05). The comparison of magnesium, zinc, cadmium, arsenic, and selenium content in wheat showed statistically significant differences ( Fadmium, selenium = 6.34, 3.31, Hmagnesium, zinc, arsenic = 6.12, 11.55, 6.23, P < 0.05). The comparison of calcium, iron, magnesium, chromium, nickel, copper, zinc, cadmium, lead, arsenic, mercury, iodine, and fluoride content in corn showed statistically significant differences ( Fmagnesium, chromium, nickel, copper, zinc, iodine = 18.89, 13.76, 17.86, 24.17, 28.46, 15.96, Hcalcium, iron, cadmium, lead, arsenic, mercury, fluoride = 11.57, 40.53, 26.50, 33.05, 33.73, 36.01, 29.21, P < 0.05). The comparison of calcium, iron, magnesium, chromium, zinc, cadmium, lead, arsenic, mercury, and selenium content in vegetables showed statistically significant differences ( H = 23.93, 8.12, 10.03, 7.01, 16.09, 18.36, 23.07, 6.51, 27.67, 7.86, P < 0.05). Conclusions:There are significant differences in the distribution of 14 elements in soil, grain, and vegetables in different water iodine regions. In addition to drinking water, precise guidance should also be provided based on the iodine content in soil, grain, and vegetables in different water iodine areas.

Objective:To investigate the distribution of iodine and other chemical elements in soil, grain and vegetables in different water iodine areas of Xi'an City, and to provide theoretical basis for prevention and treatment of iodine related diseases and water improvement measures.Methods:From September to November 2021, a stratified cluster sampling method was used to select three survey villages in Xi'an, namely Yehu Village, Xingbei Village, and Quanzhong Village, where the iodine level of residents' drinking water < 10, 10 - 100, and > 100 μg/L. Drinking water samples were collected from seven survey sites based on the source of domestic drinking water to determine the iodine level of the water. At the same time, soil samples of cultivated land, residents' grains (wheat, corn), and vegetables were collected from survey villages to determine the content of 14 elements including calcium, iron, magnesium, chromium, nickel, copper, zinc, cadmium, lead, arsenic, mercury, selenium, iodine, and fluoride.Results:The iodine level in the water of 7 survey sites in three survey villages was 5.80, 6.40, 25.51, 42.20, 53.90, 111.65, and 177.63 μg/L, respectively. A total of 70 samples of soil, 65 samples of wheat, 76 samples of corn, and 141 samples of vegetables were collected. Among them, the levels of various elements in vegetables and grains were lower than those in the soil. Only calcium and fluoride were higher in vegetables than in grains, while iron, chromium, copper, zinc, selenium, and iodine were lower in vegetables than in grains. According to the range of water iodine level, there were statistically significant differences in the content of calcium, iron, chromium, nickel, copper, zinc, mercury, iodine, and fluoride in soils from different water iodine regions ( Fcalcium, iron, chromium, nickel = 42.04, 13.55, 12.22, 11.20, Hcopper, zinc, mercury, iodine, fluoride = 14.27, 9.19, 14.72, 25.14, 16.50, P < 0.05). The comparison of magnesium, zinc, cadmium, arsenic, and selenium content in wheat showed statistically significant differences ( Fadmium, selenium = 6.34, 3.31, Hmagnesium, zinc, arsenic = 6.12, 11.55, 6.23, P < 0.05). The comparison of calcium, iron, magnesium, chromium, nickel, copper, zinc, cadmium, lead, arsenic, mercury, iodine, and fluoride content in corn showed statistically significant differences ( Fmagnesium, chromium, nickel, copper, zinc, iodine = 18.89, 13.76, 17.86, 24.17, 28.46, 15.96, Hcalcium, iron, cadmium, lead, arsenic, mercury, fluoride = 11.57, 40.53, 26.50, 33.05, 33.73, 36.01, 29.21, P < 0.05). The comparison of calcium, iron, magnesium, chromium, zinc, cadmium, lead, arsenic, mercury, and selenium content in vegetables showed statistically significant differences ( H = 23.93, 8.12, 10.03, 7.01, 16.09, 18.36, 23.07, 6.51, 27.67, 7.86, P < 0.05). Conclusions:There are significant differences in the distribution of 14 elements in soil, grain, and vegetables in different water iodine regions. In addition to drinking water, precise guidance should also be provided based on the iodine content in soil, grain, and vegetables in different water iodine areas.

Objective:To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey.Methods:From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis.Results:The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant ( P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index ( P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels ( P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables ( P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061–1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039–1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260–2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127–1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168–1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608–0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495–0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534–0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428–0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674–0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944–1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783–1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion:The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

Objective:To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey.Methods:From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis.Results:The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant ( P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index ( P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels ( P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables ( P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061–1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039–1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260–2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127–1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168–1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608–0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495–0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534–0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428–0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674–0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944–1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783–1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion:The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

Objective:To evaluate the effect of different water-improving methods on dental fluorosis of children aged 8 to 12 in drinking-water-borne fluorosis areas in Xi'an City, and provide basis for making fine prevention and control measures.Methods:In 2018, 50 drinking-water-borne fluorosis villages in Xi'an City with water improvement time from 2011 to 2013 were selected as survey sites. The condition and the way of water improvement were surveyed, water fluoride content was determined and the prevalence of dental fluorosis in children aged 8 to 12 was examined, and the rates of dental fluorosis were compared before and after the water improvement in the 50 villages.Results:The water-improving projects were in normal operation in 50 villages. The medians of water fluoride content were 0.31, 0.88 and 1.14 mg/L in villages with municipal water supply, low fluorine well and defluoridation treatment water supply (the villages of different water-improvement methods were 12, 24 and 14, respectively), the differences were statistically significant ( H = 75.54, P < 0.01). The qualification rates of water fluoride in villages with different water-improvement methods were 100.00% (12/12), 79.17% (19/24) and 57.14% (8/14), and the difference was statistically significant (χ 2 = 6.95, P < 0.05). The detection rate of dental fluorosis was 43.17% (218/505) in the 11 villages with excessive water fluoride content, and the detection rate was 20.77% (331/1 594) in the 39 villages with qualified water fluoride content, the difference was statistically significant (χ 2 = 99.66, P < 0.01). After water improvement, the total detection rate of dental fluorosis (26.16%, 549/2 099) in the 50 villages was lower than that before water improvement (41.66%, 959/2 302), the difference was statistically significant (χ 2 = 117.17, P < 0.01). The detection rates of dental fluorosis were reduced after the water improvement in villages with municipal water supply and low fluorine well, the differences were statistically significant (χ 2 = 74.37, 69.36, P < 0.01). The detection rate was declined after water improvement in villages with defluoridation treatment water supply, but the difference was not significant (χ 2 = 0.78, P > 0.05). There was a statistically significant difference in the detection rate of dental fluorosis among children in villages with different water-improvement methods (χ 2 = 72.79, P < 0.01). The detection rate of dental fluorosis in villages with defluoridation treatment water supply [39.53% (200/506)] was higher than that in villages with municipal water supply [17.97% (133/740)] and low fluorine well [25.32% (216/853)], the differences were statistically significant ( P < 0.017); the detection rate of dental fluorosis in villages with municipal water supply was lower than that in villages with low fluorine well ( P < 0.017). Conclusions:The dental fluorosis of children's has been effectively controlled in the villages after water improvement in Xi'an City. The fluoride content in the water and the detection rate of dental fluorosis in children in some endemic areas are still high. It is necessary to further improve the water quality or consolidate the improvement effect as soon as possible.

Objective: To evaluate the dynamic prevalence of dental fluorosis of children and levels of fluoride in drinking water after improvement of water in Xi an City, to provide scientific basis for water fluoridation improvement. Methods: A total of 35 fluorosis endemic villages were selected as fixed monitor sites in 2014-2018, the ways of water improvement were surveyed, water fluorine content were detected and the prevalence of dental fluorosis in children aged 8 to 12 years were examined. Results: Rates of excess fluoride in drinking water from 2014 to 2018 were 22.86%, 14.29%,11.43%, 11.43% and 8.57%, the difference were significant(χ2=16.44, P<0.01).The dental fluorosis detection rates of children aged 8 to 12 years were 20.89%,18.22%,17.46%,18.13% and 16.76% in 2014-2018 which showed a obvious descending trend by year(χ2=10.02, P<0.01). The detection rate of dental fluorosis in children aged 8 and 9 years showed a decreasing trend by year(χ2=6.53, 4.54, P<0.05).The difference of total rate of dental fluorisis,rate of mild cases rate of moderate-to-severe cases were statistically between the villages without qualified water and the villages with normal fluorine water(χ2=179.22, 167.93,10.35, P<0.01). The rate of detection in the villages with the water fluorine exceed standard in 2014-2018 showed a declining trend year by year(χ2=28.50, P<0.01). The detection rate were significant different across water improvement methods(χ2=197.76, P<0.01). Detection rate of dental fluorosis decreased from 2014 to 2018 in the areas with municipal water supply showed a decreasing after year(χ2=12.16, P<0.01). Conclusion The improvement of municipal water supply shows significant effects on water fluorosis control, the detection rate of water fluoride and children s dental fluorosis in some villages with the other ways of water improvement are still higher than expected, the continuously monitor of fluoride content in water and dental fluorosis in children should be strengthened.

Objective:To assess the implementation of control measures and dental fluorosis of children in drinking-water-borne endemic fluorosis areas in Xi'an City, and to evaluate the implementation effects of the prevention and control measures.Methods:All drinking-water-borne endemic fluorosis villages in Xi'an were selected as the investigation sites. The progress and running condition of all water-improved projects were investigated, fluoride concentration in all the water-improved projects and tap water were tested. "Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to test the water fluoride. A cross-sectional analytical study was conducted on school children aged 8 - 12 years old, the dental fluorosis was determined according to "Diagnosis of Dental Fluorosis" (WS/T 208-2011).Results:There were 273 drinking-water-borne endemic fluorosis villages, the rate of water improved villages was 91.58% (250/273), and all of the water-improved projects were operating normally (100.00%, 196/196). The rate of water-improved projects with qualified water fluoride was 88.27% (173/196), 237 villages had fluoride safe drinking water and the qualified rate was 86.81% (237/273). The median of water fluoride in the 250 villages with water-improved projects was 0.78 mg/L, the median was 0.83 mg/L in the 23 villages without water-improved projects, and the difference was not significant ( Z = 1.475, P > 0.05) . The overall prevalence of dental fluorosis among children aged 8 - 12 years old was 19.86% (1 960/9 871), and the dental fluorosis index was 0.39. The prevalence of dental fluorosis in the villages with qualified water fluoride was 16.13% (1 377/8 539), and the rate was 43.77% (583/1 332) in the villages with unqualified water fluoride, and the difference was significant (χ 2 = 553.283, P < 0.01). The prevalence of dental fluorosis in children with water fluoride content of 0.00 - 1.20, 1.21 - 1.50, and ≥1.51 mg/L was 16.13% (1 377/8 539), 41.20% (281/682), 46.46% (302/650), and the difference was significant (χ 2 = 559.011, P < 0.01), the severity of the disease was positively correlated with water fluorine concentration ( r = 0.273, P < 0.01). The epidemic situation in 202 villages was effectively controlled and 71 villages did not reach the control standard. Conclusions:The progress of water-improved projects and the rate of qualified water fluoride are not optimistic in Xi'an, the dental fluorosis of children is still higher than the government standard in the high fluoride drinking-water areas. The measures for water improving defluorination and disease surveillance should be strengthened.

Objective:To evaluate the prognostic value of arterial lactate (Lac) combined with central venous-to-arterial carbon dioxide difference to arterial-to-central venous oxygen content difference ratio (Pcv-aCO 2/Ca-cvO 2) in patients with septic shock following early fluid resuscitation. Methods:A total of 97 patients with septic shock admitted to intensive care unit (ICU) of Lanzhou University Second Hospital from January 2017 to December 2019 were enrolled. The Pcv-aCO 2/Ca-cvO 2 ratio was calculated from blood gas analysis of radial artery and superior vena cava which was performed before resuscitation and at 6 hours of resuscitation at the same time. The patients were divided into death group and survival group according to the 28-day prognosis. The baseline data, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score, sequential organ failure score (SOFA), clinical therapy, lactate clearance rate (LCR) at 6 hours, the length of ICU stay, hemodynamics and oxygen metabolism parameters before and after resuscitation were compared between the two groups. Risk factors were analyzed by multivariate Cox regression for 28-day mortality of patients with septic shock. The receiver operating characteristic (ROC) curve was plotted to assess the prognostic values of these factors for 28-day mortality. Results:① Compared with the survival group, the patients in the death group showed significantly higher levels of APACHEⅡ score (23.96±4.31 vs. 17.70±3.92) and SOFA score (12.74±2.80 vs. 9.23±2.43, both P < 0.01), significantly higher proportions of mechanical ventilation [85.2% (23/27) vs. 50.0% (35/70)] and continuous renal replacement therapy [CRRT; 51.9% (14/27) vs. 25.7% (18/70), both P < 0.05], a significantly more fluid replacement at 6 hours (L: 2.92±0.24 vs. 2.63±0.25, P < 0.01), a significantly lower level of LCR at 6 hours [(11.61±7.76)% vs. (27.67±13.71)%, P < 0.01], and a shorter length of ICU stay (days: 6.37±2.70 vs. 7.67±2.31, P < 0.05). ② Compared with the survival group, the patients before resuscitation in the death group showed a significantly lower level of mean arterial pressure [MAP (mmHg, 1 mmHg = 0.133 kPa): 52.63±4.35 vs. 55.74±3.01, P < 0.01], significantly higher levels of Lac and Pcv-aCO 2/Ca-cvO 2 ratio [Lac (mmol/L): 7.13±1.75 vs. 5.22±1.36, Pcv-aCO 2/Ca-cvO 2 ratio: 1.67±0.29 vs. 1.48±0.22, both P < 0.01]; and the patients at 6 hours of resuscitation in the death group showed a significantly lower level of MAP (mmHg: 62.59±4.80 vs. 66.71±3.91, P < 0.01), significantly higher levels of central venous pressure (CVP), Lac, Pcv-aCO 2 and Pcv-aCO 2/Ca-cvO 2 ratio [CVP (mmHg): 10.74±1.40 vs. 8.80±0.75, Lac (mmol/L): 6.36±1.86 vs. 3.90±1.95, Pcv-aCO 2 (mmHg): 7.59±2.02 vs. 4.34±1.37, Pcv-aCO 2/Ca-cvO 2 ratio: 1.87±0.51 vs. 1.03±0.27, all P < 0.01]. ③ Multivariate Cox regression analysis showed that the independent risk factors for 28-day mortality in patients with septic shock were Lac and Pcv-aCO 2/Ca-cvO 2 ratio whether before or at 6 hours of resuscitation [Lac before resuscitation: relative risk ( RR) = 1.434, 95% confidence interval (95% CI) was 1.070-1.922, P = 0.016; Lac at 6 hours of resuscitation: RR = 1.564, 95% CI was 1.202-2.035, P = 0.001; Pcv-aCO 2/Ca-cvO 2 ratio before resuscitation: RR = 2.828, 95% CI was 1.108-4.207, P = 0.038; Pcv-aCO 2/Ca-cvO 2 ratio at 6 hours of resuscitation: RR = 4.386, 95% CI was 2.842-5.730, P = 0.000]. ④ ROC curve analysis showed that Lac and Pcv-aCO 2/Ca-cvO 2 ratio at 6 hours of resuscitation had predictive value for the prognosis of patients with septic shock, the area under ROC curve (AUC) was 0.849 (95% CI was 0.762-0.914) and 0.905 (95% CI was 0.828-0.955), respectively. However, the predictive value of Lac combined with Pcv-aCO 2/Ca-cvO 2 ratio in patients with septic shock was significantly higher than Lac [AUC (95% CI): 0.976 (0.923-0.996) vs. 0.849 (0.762-0.914), Z = 3.354, P = 0.001], the sensitivity was 97.14%, and the specificity was 88.89%. Conclusions:Lac and Pcv-aCO 2/Ca-cvO 2 ratio are independent risk factors for predicting 28-day mortality in patients with septic shock. Lac combined with Pcv-aCO 2/Ca-cvO 2 ratio can assess the prognosis of patients with septic shock more accurately.

Objective To assess the effects of defluoridation on prevalence of children's dental fluorosis in Xi'an City and study related influencing factors.Methods In 2017,the survey results of 2013 were collected from the previous investigation of drinking water type fluorosis in Xi'an Center for Disease Control and Prevention,and villages from drinking water type fluorosis areas were divided into five groups:0.0-,0.2-,0.5-,1.0-,and ≥ 1.5 mg/L,according to the fluoride concentrations of water.Four villages were randomly selected from each group,a total of 20 villages were selected as the investigation sites.A cross-sectional analytical study was conducted in the 20 villages,the fluoride in drinking water,the dental fluorosis of children aged 8-12 years and fluoride content in urine were detected,and the survey results were compared with those of 2013.Children were divided into five groups according to urinary fluoride contents as:0.0-(control),0.4-,0.8-,1.2-,and ≥ 1.6 mg/L,and the logistic regression model was used to evaluate the risk of dental fluorosis.Results There were no significant differences in water fluoride content between 2013 and 2017 (P ＞ 0.05).The rates of dental fluorosis among the study population in 2013 and 2017 were 25.35％ (200/789) and 20.58％ (164/797),and the difference was significant (x2 =5.11,P＜0.05).The prevalence rate and severity of dental fluorosis in 2013 [3.52％ (9/256),13.28％ (17/128),31.62％ (43/136),37.82％(45/119),57.33％(86/150)] and 2017[4.02％(10/249),11.82％(13/110),18.05％(24/133),29.13％(37/127),44.94％ (80/178)] were significantly increased with increase of water fluoride concentration (x2 =168.02,117.83,P ＜ 0.01).The prevalence rate of dental fluorosis was higher than 30％ in the three groups with water fluoride content 0.5-,1.0-and ≥ 1.5 mg/L in 2013,and the prevalence rates were decreased in these groups in 2017.The prevalence rate of dental fluorosis was lower than 30％ in the groups with water-fluorine content of 0.5-,1.0-＜1.5 mg/L,while the rate of dental fluorosis in the group with water-fluorine content of higher than 1.5 mg/L was still over 40％.The geometric mean of urinary fluoride of children in 2013 and 2017 were 1.02,0.67 rg/L,and the difference was significant (t =10.24,P ＜ 0.01).There were significant differences in children urinary fluoride between water fluoride groups in 2013 and 2017 (F =85.36,151.14,P ＜ 0.01).The risk of dental fluorosis increased with increase of urinary fluoride content,the odds ratio (OR) values were 5.26,7.83 and 13.28 in the three groups with the urinary fluoride 0.8-,1.2-,≥1.6 mg/L in 2013;the OR values in 2017 were 5.18,7.65 and 13.36,the differences were statistically significant (P ＜ 0.05).Conclusions The situation of water fluoride and dental fluorosis are not optimistic after defluoridation of drinking water.It is necessary to reinforce the measures of water defluoridation,and carry out classified management in endemic fluorosis areas.

Objective To investigate the effects of mild hypothermia on post-resuscitation neurological outcome after ventricular fibrillation (VF) in rabbits.Methods Forty-five adult New Zealand rabbits were induced VF by direct current of electricity.The rabbits were randomly(random number) divided into following groups:normothermic resuscitation group (NR),mild hypothermia prearrest group (HP),mild hypothermia resuscitation 30 min group (HRe30),mild hypothermia resuscitation 90 min group (HRe90),normothermic sham group (NS),and hypothermia sham group (HS).The rabbits of NR group were observed for 600 min in room temperature after restoration of spontaneous circulation (ROSC).The mild hypothermia was induced by surface cooling,and maintained for 600 min after the aimed low temperature reached.The arterial blood samples were collected for determining neuron-specific enolase (NSE) and thioredoxin (Trx) and the mean arterial pressure (MAP),left ventricular end-diastolic pressure (LVEDP) and left ventricular pressure raise and fall rate (±dp/dtmax) were observed at 15 min before CA,and 30 min,60 min,120 min,360 min and 600 min after ROSC.After the animals were sacrificed at 600 min after ROSC,the whole brain of animals was harvested and observed under light microscope to calculate the apoptotic index of the hippocampal CA1 neurons by using TUNEL method.One-way ANOVA was used to determine the statistical significance between two groups,a two-tailed value of P＜0.05 was considered statistically significant.Results (1) Hemodynamically compared with normal temperature groups,HR was lower in hypothermia groups.Compared with NR,HRe30,and HRe90 group,LVEDP was higher in HP group at 30 min after ROSC(3.4±0.8 vs.4.6±1.0,4.1±0.5,4.3±0.2,F=9.85,P=0.019).In Hp group,the level of +dp/dtmax was higher than that in NR,HRe30 and HRe90 groups at 30 min and 120 min after ROSC.In HP group,the level of-dp/dtmax was higher than that of NR group at 30 min,60 min,120 min,360 min and 600 min after ROSC.(2) Serologically compared with HP,HRe30 and HRe90 group,NSE levels were higher in NR group at 60 min,120 min and 360 min after ROSC.Compared with NR,HRe30,and HRe90 group,Trx levels in NR group were lower at 60 min,120 min,360 min and 600 min after ROSC.Compared with HP group,Trx levels in HRe30 and HRe90 groups were higher at 60 min,120 min,360 min and 600 min after ROSC.(3) Pathologically compared with NR group,histopathological changes in hippocampus CA1 area were milder found in HP,HRe30 and HRe90 groups.AI (％) was lower in HP,HRe30 and HRe90 groups than that in NR group[(62.25±10.43)％ vs.(20.61±5.02)％,(25.08±3.92)％,(30.33±7.15)％,P=0.001].Concusions This study shows that hypothermia should be initiated as soon as possible,and especially early intra-arrest cooling appears to be significantly better than post-ROSC cooling and normothermia.