ABSTRACT
Objective@#To understand the prevalence and trend of the poor eyesight in primary and middle school students in Beijing, and to provide theoretical basis for eyesight protection and myopia prevention and control.@*Methods@#According to "Technical Standard for Student Health Inspection" (GB/T 26343-2010), students were examined with a standard logarithmic visual acuity E chart for naked eye vision.@*Results@#The prevalence of poor eyesight among primary and middle school students in 2010-2016 was 63.0%, 62.1%, 62.9%, 60.7%, 59.2% and 58.6% respectively, decreased by 7.0% in 6 years, primary school students dropped by 9.7%, and junior school students, senior high school students and vocational high school students increased by 5.5%, 3.3% and 14.1% respectively. Urban and suburban areas(61.2%，54.3%) decreased by 9.6% and 2.9% respectively. Regardless of boys and girls, urban and suburb, between 2010 and 2016, the overall composition ratio of students in each school segment was expressed as primary school > junior school > senior high school students > vocational high school, and vocational high school students accounted for the minimum; the overall composition ratio of primary school has become more and more large.@*Conclusion@#Eyesight protection and myopia prevention among primary and middle school students in Beijing is still challenging. All departments should take active and effective measures to control the newly onset and progression of low vision and improve eyesight.
ABSTRACT
A rapid method was developed for the determination of 5 common fatty acids, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid in industrial oleic acid based on ultra_performance convergence chromatography_mass spectrometry ( UPC_MS) . The sample was dissolved by n_hexane, followed by clean_up of extract using 0. 22 μm organic phase filter. The fatty acids were separated in 3 min on the column of Acquity UPC2 BEH 2_EP by gradient elution with carbon dioxide and methanol/acetonitrile (1∶1, V/V) system, and finally detected by MS detector in ESI- mode. Through the optimization of UPC2_MS condition, the reasonable linearity was achieved for all the analytes over the range of 0. 5-100 mg/L with the correlation coefficients ( R2 ) greater than 0. 9985. The recoveries for five fatty acids at three spiked levels were in the range from 89 . 3% to 106 . 67% with relative standard deviations of 0 . 8%-3 . 0%. The limits of detection for target compounds in the method ranged from 0. 07 mg/L to 0. 26 mg/L. The real sample analysis showed that this method was simple,fast and had a good separation effect. There was no need of derivatization for fatty acid samples. This work would provide a fast and effective detection method for UPC2 technology in oil related research field.
ABSTRACT
Objective To analyze the data of HIV antibody mass screening in Tianjin from 2005 to 2006 and to evaluate current screening strategy.Methods Confirmation tests were conducted for 601 samples received form HIV screening laboratories in Tianjin in line with the procedures and methods defined by the National Guideline for HIV/AIDS Detection.Results Of the 601 samples,215 were HIV antibody positive(with complete bands);24 samples were positive with special reactive blots,of which 10 cases were followed up with 7 confirmed to be infected with HIV and with 3 confirmed to be excluded;51 samples were uncertain with indeterminate blots,of which 8 cases were followed up and all were proved to be HIV antibody negative.Conclusion Routine HIV screening as part of medical examinations for patients in health care settings or for detained personnel in police and judicial organizations represents an important approach to detect cases of HIV infection,Samples with special reactive blots or indeterminate blots should be handled with caution;they should be followed up and may be tested by other approaches,such as blot test or viral genome detection.