Objective To determine the contents of fluoride and tea polyphenols in brick-tea and to understand the utilization ratio of qualified brick-tea in fluorosis regions in Inner Mongolia.Methods The investigation was carried out in Chenbaerhuqi Country and Eweukeqi Country.Seventy-two households of four villages in Chenbaerhuqi and 11 households of three villages in Ewenkeqi were selected as study subjects.The brick-tea in each household was sampled.The contents of fluoride and tea polyphenols were determined by using fluoride selective electrode method and Forint-Ciocalteu oxidation method,respectively.T test and linear correlation were used to analyze the data.Results The fluoride content in qualified brick tea ranged from 114.82 mg/kg to 290.23 mg/kg with an average value of 171.78 mg/kg,while tea polyphenols content was between 56.15 g/kg and 132.18 g/kg with an average value of 95.44 g/kg.In unqualified brick-tea,the average fluoride content was 459.86 mg/kg with the range from 304.71 mg/kg to 660.76 mg/kg and the average of tea polyphenols was 67.48 g/kg with the range from 36.03 g/kg to 102.15 g/kg.The content of tea polyphenols of qualified brick tea was significantly higher than that of unqualified brick tea (P ＜ 0.05).The content of tea polyphenols was negatively correlated with fluoride content(r =-0.636,P ＜ 0.05).The content of tea polyphenols was 396 times more than that of fluoride in brick tea.The utilization ratio of qualified brick-tea in the investigation areas was 53.0％(44/83).Conclusion The fluoride content in qualified brick-tea was less than unqualified brick-tea,and the tea polyphenols of qualified brick-tea was higher than the unqualified brick-tea.The utilization rate of qualified brick tea is not high and further actions are needed to be taken to supply more qualified brick-tea for controlling of drinking brick-tea type fluorosis.

ve To investigate the intake of fluoride of residents in pastoral area of Beier Lake and its main source. Methods Two of the typical endemic fluorosis villages were selected as observation sites in Xinbaerhuyouqi County of Inner Mongolia Autonomous Region. The amount of milk-tea drank by residents was investigated, the drinking water samples, brick-tea samples and milk-tea samples were collected from 10 families randomly selected as observation families. The contents of fluoride of 3 kinds of samples were determined by iron selective electrode method. Results The contents of fluoride in drinking water samples, brick-tea samples and milk-tea samples reached higher levels, namely, 4.12-4.37 mg/L, 780.3-800.0 mg/L and 5.80-5.88 mg/L respectively in two investigation sites. The intake of fluoride from milk-tea of adults was (8.70 ?3.91) mg/d and (9.50?3.22) mg/d respectively, of which, 75.34% and 70.07% came from drinking water, 24.66% and 29.93% came from brick-tea in two observation sites. Conclusion The two observation sites with the higher levels of fluoride intake far exceeding the related Na-tional Standards were composite endemic fluorosis area with a fluoride exposure route mainly via drinking water.

Objective To investigate the implementation effects of control measures and the dynamic prevalence of drinking-water-borne endemic fluorosis,in order to provide a scientific basis for developing control measures against the disease.Methods According to the Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis,137 counties were selected as monitoring counties in national 27 provinces (autonomous regions,municipalities) and Xin Jiang Production and Construction Corps.Three epidemic villages were selected as fixed monitoring villages in each county.The operating condition and the fluoride level of water improvement projects were investigated in the villages with water improvement projects.The fluoride level of drinking water was tested in the villages without water improvement projects.The fluoride content in drinking water was detected by the Standard Test Method for Drinking Water (GB/T 5750.5-2006).The preyalence of dental fluorosis of all children aged 8-12 were surveyed,and dental fluorosis was diagnosed by Clinical Diagnostic Criteria of Dental Fluorosis (WS/T 208-2011).Results ①427 villages were surveyed in 2012,among which the villages with water improvement projects accounted for 75.88％ (324/427).② 299 water improvement projects were investigated.Normal operation rates of those were 89.30％ (267/299).The qualified rate of fluoride content was 75.78％ (219/289).Totally 103 villages without water improvement projects were monitored.Villages with fluoride level ＞ 1.2-2.0 mg/L,＞ 2.0-4.0 mg/L and ＞ 4.0 mg/L accounted for 48.54％ (50/103),29.13％ (30/103) and 9.71％ (10/103),respectively.(③The national detection rate of dental fluorosis and community fluorosis index (CFI) in children aged 8-12 were 31.24％ (8 677/27 773) and 0.66.The detection rate and CFI of the villages with normal operation projects and the qualified fluoride content were 24.04％ (3 999/16 634) and 0.51.The detection rate and CFI of the villages with water improvement projects under abnormal operation or excessive fluoride were 40.77％ (1 654/4 057) and 0.91.The rate and CFI of the villages without water improvement projects were 42.70％ (3 024/7 082) and 0.86.Conclusions The rate of water improvement projects of the whole country is lower.The national normal operation rate of water defluoridation improvement projects is below 90％,and the qualified rate of fluoride content in drinking water is below 80％.The prevalence of dental fluorosis in children aged 8-12 is very mild.

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Objective:To compare the clinical prognosis of modified and traditional knotless suture bridge technique in treatment of rotator cuff tear under shoulder arthroscopy.Methods:A retrospective case-control study was conducted to analyze 60 patients with rotator cuff tear admitted to Affiliated Hospital of Qingdao University from June 2018 to June 2019，including 19 males and 41 females，aged 32-74 years［（59.3±10.1）years］. There were 26 patients on the left side and 34 patients on the right side，with the body mass index（BMI）of 19.5-32.4 kg/m 2［（25.5±2.6）kg/m 2］，rotator cuff tear of 2.0-3.7 cm［（2.7±0.4）cm］and pain duration of 2-88 days［（26.2±17.1）days］. A total of 31 patients were repaired with a modified knotless suture bridge（modified group）and 29 patients with a traditional knotless suture bridge（traditional group）. Comparison was made between the two groups in aspects of range of motion of shoulder flexion，abduction and external rotation，visual analog scale（VAS），University of California Los Angeles（UCLA）should function score，Constant shoulder function score，retear and complications at postoperative 3 and 12 months. Results:All patients were followed up for 9-15 months［（12.0±1.8）months］. Three months after operation，the two groups showed no significant differences in shoulder range of motion of abduction，flexion，external rotation，UCLA shoulder function score or Constant shoulder function score（ P>0.05）；while VAS was（2.7±1.2）points in modified group，significantly lower than（3.4±1.2）points in traditional group（ P<0.05）. Twelve months after operation，the shoulder range of motion of abduction and flexion in modified group was（146.9±21.4）° and（150.4±16.2）°，significantly higher than that in traditional group［（130.7±27.4）°，（140.6±18.4）°］（ P<0.05）；There was no significant difference in external rotation activity between the two groups（ P>0.05）；VAS，UCLA shoulder function score and Constant shoulder function score［（1.2±0.5）points，（29.5±2.3）points，（80.4±5.4）points，respectively］in modified group were significantly higher than those in traditional group［（1.5±0.5）points，（27.2±2.7）points，（76.3±6.6）points，respectively］（ P<0.05）. Three months after operation，there was no significant difference in the classification of Sugaya between the two groups（ P>0.05）. Twelve months after operation，the classification of Sugaya was significantly different between the two groups（ P<0.05），with no retear in modified group but 3 patients with retear in traditional group. No postoperative complications occurred，such as non-healing，infection or persistent swelling. Conclusion:For patients with rotator cuff tear，the modified knotless suture bridge technique under shoulder arthroscopy has better range of motion and function，more obvious pain relief and a lower rate of retear than the traditional technique.

Objective To understand the status of fluoride content in brick tea (pressed tea) in China,and conduct health risk assessment according to the situation of drinking brick tea in fluorosis areas.Methods Twenty national designated brick tea manufacturers were selected to collect 1-5 varieties of brick tea samples of mainstream varieties with large production volume and large sales volume.If low-fluoride brick tea was produced,an additional sample would be collected to determine the fluoride content of tea.The retrospective analysis method was used to collect the monitoring data of brick tea-type fluorosis in the whole country in 2017,and analyze the use of brick tea in the residents of the brick tea-type fluorosis areas in six provinces (regions) of Inner Mongolia,Sichuan,Gansu,Ningxia,Xinjiang and Qinghai.According to the fluoride content of brick tea,combined with daily average consumption data of brick tea in the brick tea-type fluorosis areas,daily average brick tea intake,and hazard quotient of the daily average brick tea fluoride and the standard recommended fluoride intake were calculated.A health risk assessment was conducted based on the hazard quotient (hazard quotient ＞ 1 indicated a health risk).Through the total fluoride intake standard of the Chinese population,the safe consumption of brick tea with different fluoride content was simulated by using the value of the hazard quotient.The tea fluoride was measured by an ion selective electrode method.Results A total of 54 samples were collected,of which 49 were brick tea samples and 5 were low-fluoride brick tea samples.The geometric mean of the fluoride content of 49 brick tea samples was 460 mg/kg,the median was 430 mg/kg,and the range was 102-1 797 mg/kg.There were 14 samples with a fluoride content ＜ 300 mg/kg,accounting for 28.6％.The average fluoride content of 5 low-fluoride brick teasampleswas 193 mg/kg,ranging from 102 to 290 mg/kg.Forty-nine brick tea samples were distributed in 5 provinces,the fluoride content of brick tea was the lowest in Yunnan,128 mg/kg;the highest in Hubei,712 mg/kg.The lowest fluoride content of brick tea in different varieties was Tuo tea,130 mg/kg,and the highest was Jinjian tea,745 mg/kg.There were 1 000 households drinking brick tea in the brick tea-type fluorosis areas in 6 provinces,73.9％ (739/1 000) of households drinking the products of the national assigned brick tea manufacturers;a total of 1 000 brick tea samples were collected,and the geometric mean of brick tea fluoride content was 551 mg/kg,and only 17.5％ (175/1 000) of brick tea had a fluoride content ＜ 300 mg/kg.Compared with the national standards and the standards of World Health Organization,hazard quotient of agriculture,animal husbandry,semi-pastoral industry,urban residents through the brick tea fluoride was 0.34,1.38,0.75,and 0.21,respectively;0.29,1.21,0.66,and 0.19,respectively.Animal husbandry hada health risk through drinking brick tea among them.According to the health standard of total fluoride intake in China,when drinking brick tea with fluoride contents of 300,430,460 and 500 mg/kg,the safe consumption of brick tea for school-age children was 2.9,2.0,1.9 and 1.8 kg,respectively,and for adult was 4.3,3.0,2.8 and 2.6 kg,respectively.Conclusions Brick tea has high fluoride content,and percent of qualified brick tea is low and few of low-fluoride brick tea are consumed.There is a health risk in the animal husbandry who has a large amount of brick tea.

Objective To investigate the prevalence of fluorosis and related control measures on drinking water type of endemic fluorosis in China.Methods According to the national program"Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis",136 counties were selected in 29 provinces,autonomous regions and municipalities.Three epidemic villages were randomly selected as fixed monitoring sites in each county.Dental fluorosis of all the children aged 8-12 living in the villages under the monitoring program,was identified under the ariteria from "Diagnosis of dental fluorosis"(WS/T 208-2011).Operating conditions and contents of fluoride in all the'water-improved projects' were investigated.Contents of fluoride in drinking water were tested in villages without the 'water-improved projects'."Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to detect the water fluoride.Results The overall prevalence of dental fluorosis among children aged 8-12 in all the villages under monitor program,was 28.58％ (7 950/27 817),with the dental fluorosis index (DFI) as 0.58.Among them,the prevalence was 22.28％ (3 917/17 583) and DFI was 0.44 in the' water-improved projects' villages that under normal operation and with qualified fluoride contents.The prevalence appeared as 38.74％ (1 926/4 971) with DFI as 0.84 in those villages with 'water-improved projects' but mal-operated or with excessive fluoride.The prevalence was 40.03％ (2 107/5 263),and DFI was 0.81 in those villages without'water-improved projects'.The prevalence rates of dental fluorosis in children from the three types of endemic areas were significantly different.For 'water-improved projects',the normal opration rate was 93.77％ (286/305) and the qualification rate of fluoride content was 76.77％ (228/297).Conclusions Dental fluorosis in children living in the drinking-water-born endemic fluorosis areas was on the edge of epidemics in China.Effective improvement on the quality of drinking water can significantly reduce the severity of dental fluorosis in children.The rate of proper operation on 'water-improved projects' was near to 95％ in the endemic area.However,rate that met the criteria on qualified fluoride contents of these projects was still below 80％.