Objective Focusing on the problem such as slow scanning speed, complex system design and low light efficiency, a new parallel confocal 3D profile detecting method based on optical fiber technology, which realizes whole-field confocal detecting, is proposed. Methods The optical fiber plate generates an 2D point light source array, which splits one light beam into N2 subbeams and act the role of pinholes as point source and point detecting to filter the stray light and reflect light. By introducing the construction and working principle of the multi-beam 3D detecting system, the feasibility is investigated. Results Experiment result indicates that the optical fiber technology is applicable in rotation. The measuring parameters that influence the detecting can easily be adapted to satisfy different requirments of measurement. Compared with the conventional confocal method, the parallel confocal detecting system using optical fiber plate is simple in the mechanism, the measuring field is larger and the speed is faster.

Objective To monitor the situation of iodine deficiency disorders (IDD) in Tibet,and to provide a background information of iodine nutritional status of residents before adjustment of iodine concentration.Methods According to the method of population proportionate sampling (PPS),27 counties were selected to carry out IDD surveillance.One primary school was selected in each county.Forty children aged 8-10 from each primary school were sampled to examine thyroid volume,and edible salt samples were collected from their home to determine salt iodine.In addition,12 of the sampled children,15 pregnant women and 15 lactating women from three townships near the selected schools were chosen to detect urinary iodine.The methods of B-ultrasonography,oxidation-reduction titration (GB/T 13025.7-1999) and arsenic cerium catalytic spectrophotometry (WS/T 107-2006) were used to determine thyroid volume,salt iodine and urinary iodine,respectively.Results One thousand and eighty-one children aged from 8 to 10 were examined,and their goiter rate was 1.9％ (20/1 081).Seven hundred and fifty-eight salt samples were determined,and the median salt iodine level was 38.3 mg/kg and the consuming rate of qualified iodized salt was 88.1％(758/668).Meanwhile,urine samples of 522 children aged 8-10,267 pregnant women and 336 lactating women were also tested,and their median urinary iodine level was 166.1,132.7,138.1 μg/L,respectively.Conclusions The results show that the goiter rate and urinary iodine level of children aged from 8 to 10 have reached the national standard of IDD elimination (＜5％,100-300 μg/L),while the residents consumption rate of qualified iodized salt is still lower than the national standard (90％).In particular,the iodine nutrition of pregnant women is inadequate,which is lower than the national standard (urinary iodine 150 μg/L).It is still necessary to strengthen the monitoring of salt iodine as well as iodine nutrition in special groups in the future,and strengthen health promotion at the same time.

Objective To study the relationship between environment selenium distribution characteristic and Kaschin-Beck disease (KBD) in the Yarlung Zangbo River banks and to provide some measures for prevention and control of KBD in the north side of the river bank.Methods Considering the geography and KBD distribution,we made a survey in Xietongmen (KBD area),Lazi and Sajia (non-KBD area) counties in 2013 and 2015.Water,soil,herbage,grain food and children hair samples were collected.Selenium of the samples was measured by hydride generation-atomic fluorescence spectrometry.Results A total of 246 samples of natural soil,cultivated soil,drinking water,food and forage,and 103 samples of children hair were collected.The selenium in natural soil,cultivated soil,herbage,barley,tsampa,self-produced wheat in non-KBD area in the south side of Yarlung Zangbo River bank were significantly higher than those in KBD areas in the north side [mean (μg/kg):288.62 vs 134.90,228.26 vs 160.28,41.85 vs 5.10,13.99 vs 4.02,12.64 vs 8.07,27.44 vs 13.56,U =7,23,0,19,62,0,P ＜ 0.05].Hair selenium in school children in KBD area in the north side was higher than that previously reported,but still significantly lower than that in non-KBD areas in the south side of the river bank [mg/kg:0.221 vs 0.306,U =650,P ＜ 0.01],and about 65.45％ (36/55)of school children in KBD area were at a risk of selenium deficiency in the north of the Yarlung Zangbo River bank.Conclusions The selenium contem in the food chain of soilplants-animals (human being) is significantly lower in KBD area in the north side of Yarlung Zangbo River bank than that in non-KBD areas in the south side.It's still a key factor for the occurrence and prevalence of KBD that low selenium in environment in KBD areas in the north side.

Objective To analyze the difference of echocardiography in patients with chronic Keshan disease (CKD) at different altitudes areas,explore the effects of altitude on the structure and functional of right heart in CKD patients,and provide a reference for imaging diagnosis of CKD.Methods According to the three step distribution of the terrain in China,30 cases of CKD patients in the first step (altitude ＞ 4 000 m) of Tibet autonomous region were randomly selected as the Tibetan plateau group.In the second step (altitude:1 000-2 000 m),31 cases were randomly selected in Gansu Province as the Loess plateau group.In the third step (altitude ＜ 500 m),42 cases were randomly selected in Shandong Province as the plain group.Echocardiography was used to analyze the morphology,hemodynamics and function of right heart.Results Right atrial transverse diameter (RATD),right ventricular transverse diameter (RVTD),right ventricular lateral wall thickness (RVWT) and main pulmonary artery diameter (MPAD) of the Tibetan plateau group,the Loess plateau group and the plain group (mm:49.75 ± 8.40,45.64 ± 7.63,43.56 ± 7.34;50.89 ± 7.13,46.56 ± 5.62,43.27 ± 6.01;4.75 ± 1.02,3.53 ± 0.61,3.37 ± 0.51;32.87 ± 3.62,28.93 ± 2.12,28.44 ± 2.71) were significant differences among the three groups (F =5.36,12.91,37.08,23.33,P ＜ 0.01).The above indexes of the Tibetan plateau group were higher than those of the Loess plateau group and the plain group (P ＜ 0.05).RVTD of Loess plateau group was higher than that of plain group (P ＜ 0.05).The fractional area change [FAC,(24.85 ± 2.75)％,(26.26 ± 3.42)％,(26.73 ± 3.14)％],tricuspid annular plane systolic excursion [TAPSE,(12.87 ± 1.12),(14.59 ± 1.63),(14.13 ± 1.31) mm] of the Tibetan plateau group,the Loess plateau group and the plain group were significant differences among the three groups (F =3.36,13.47,P ＜ 0.05 or ＜ 0.01);the above indexes of the Tibetan plateau group were lower than those of the Loess plateau group and the plain group (P ＜ 0.05).Tei index (0.87 ± 0.18,0.78 ± 0.16,0.71 ± 0.14),tricuspid flap diastolic maximum filling speed/tricuspid annulus early diastolic peak velocity (E/E',9.48 ± 1.22,8.64 ± 0.91,8.12 ± 1.13),systolic pulmonary artery pressure [SPAP,(49.58 ± 11.76),(44.35 ± 11.41),(42.67 ± 12.13) mmHg,1 mmHg =0.133 kPa] of the Tibetan plateau group,the Loess plateau group and the plain group were significant differences among the three groups (F =12.89,13.99,3.12,P ＜ 0.01 or ＜ 0.05);the Tei index and E/E'of the Tibetan plateau group were higher than those of the Loess plateau group and the plain group (P ＜ 0.05).Tei index,E/E'of the Loess plateau group were higher than those of the plain group (P ＜ 0.05).Conclusions The right heart structure and function of CKD patients are affected by the altitude of their residence.With the increase of altitude,the right heart is enlarged,the right ventricular systolic and diastolic functions are decreased,and SPAP is increased in CKD patients.

Objective To grasp the prevalence of drinking brick-tea type fluorosis in Tibet,and to provide scientific basis for the development of prevention and control strategies.Methods Twelve counties were selected from 7 regions in Tibet.In accordance with the "Drinking Brick-Tea Type Endemic Fluorosis Monitoring Program",a total of 46 administrative villages were selected as survey points using the cluster stratified sampling method.Household water samples,tea-water samples and adult urine samples were collected,and household fluorine intake status and incidence of skeletal fluorosis in adults over 16 years old were investigated.In the rural grade primary school where the village children were concentrated,all children aged 8-12 were selected,urine samples were collected,and the prevalence of dental fluorosis was investigated.Fluoride contents in tea,water,and urine were detected by ion selective electrode method.The dental fluorosis and skeletal fluorosis were examined and judged according to the "Diagnosis of Dental Fluorosis" (WS/T 208-2011) and the "Diagnostic Criteria for Endemic Skeletal Fluorosis" (WS 192-2008),respectively.Results A total of 46 villages in 12 counties were investigated,1 992 of water samples,1 662 of tea samples,664 of children urine samples,3 186 of adult urine samples were detected;547 children aged 8-12 were examined dental fluorosis and 3 196 adults were examinea skeletal fluorosis,respectively.The water fluoride contents in all the investigated villages were less than 1.0 mg/L;the average fluoride content in brick-tea water was 6.12 mg/L,within the range of 0.11-84.00 mg/L,and the average daily brick tea fluorine intake of residents was 24.98 mg.The geometric mean of urine fluoride in children and adults was 0.76,2.28 mg/L,respectively.The prevalence rates of dental fluorosis in children and skeletal fluorosis in adults over 16 years old were 31.81％ (174/547) and 48.59％ (1 553/3 196),respectively.The children dental fluorosis index was 0.60.The detection rate of skeletal fluorosis in adults aged 36-45 was 13.37％ (69/516).Conclusions The prevalence of drinking brick-tea type fluorosis in Tibet is serious and widely distributed.In particular,the prevalence rate of skeletal fluorosis in adults is relatively high,while that of dental fluorosis in children is relatively mild.The prevention and control of drinking brick-tea type fluorosis in Tibet brook no delay.

Objective:To assess the changes of selenium nutrition of school-age children in Kashin-Beck disease (KBD) areas of Linzhou County, Lhasa City and Xietongmen County, Shigatse City in Tibet Autonomous Region (referred to as Tibet), and provide a scientific basis for evaluating the effectiveness of prevention and control measures.Methods:According to the historical condition of KBD, a total of 344 children's hair samples were collected to determine the content of selenium in Kazi (KBD area) and Jiangxia townships (non-KBD area) of Linzhou County in 2013 and 2021, Renqinze (KBD area) and Tongmen townships (non-KBD area) of Xietongmen County in 2015 and 2021.Results:Compared to 2013/2015, in 2021, the hair selenium level of children in the four townships increased ( P < 0.001). The selenium nutritional level of more than 90% of the children reached medium or above (hair selenium > 0.25 μg/g) in 2021. The hair selenium levels of girls in the two KBD areas (Kazi and Renqinze townships) were lower than those of boys ( Z = - 2.83, - 2.83, P < 0.05). Conclusions:The selenium nutrition level of school-age children in KBD areas in Linzhou and Xietongmen counties has increased rapidly in recent years. However, the selenium nutrition level of girls is significantly lower than that of boys. It is necessary to strengthen prevention, controlling and monitoring, and to further improve the dietary structure of school-age children through the joint efforts of families and schools, to increase the proportion of exogenous high selenium food intake.