Eye care health behaviors among primary school students in Wenzhou during COVID-19 / 中国学校卫生

Objective@#To investigate eye care behaviors among primary students in Wenzhou during Novel Coronavirus epidemic(COVID-19),and to provide a basis for eye care education and myopia prevention strategy.@*Methods@#A total of 1 127 students from grade one to grade six of six primary schools in Wenzhou were selected to participate in an on-line invistigation regarding class attendance and eye care behaviors during the epidemic, March 6-9, 2020.@*Results@#During the epidemic period, the primary school students in Wenzhou mainly took classes on the Internet (936, 83.1%), and the main learning tools were computers (391, 34.7%) and mobile phones (344, 30.5%), with an average of 3.00 h of online class. On average, students needed 2.00 h to complete homework and 1.00 h of extracurricular reading every day. In addition to learning, the daily use of mobile phone or ipad, computer and TV was 1.00,0.50,1.00 h respectively. Limited by the epidemic situation, the average daily exercise time of students was 0.81 h, including 0.00 h of outdoor activities; the average daily sleep was 9.00 h . During the epidemic period, 553 pupils (49.1%) reported eye discomfort, of which the most common was dry eyes (379, 47.4%). Multivariate Logistic regression analysis showed that the main learning tools of non-electronic products, reading distance > 30 cm or not reading, exercise time >0.5 h and outdoor activity time > 0.5 h were the protective factors of ocular discomfort (P<0.05). More than 2 h homework and recreational screen time higher than 0.5 h were risk factors for ocular discomfort(P＜0.05).@*Conclusion@#During the epidemic period, online learning increasedeye strain.Time of electronic devices usage,correct posture for reading,moderate level of ourdan physical activity,as well as prevention and treatment of eye strain should be strictly monitored.

[Analysis on animal models of experimental hyperlipidemia].

Hyperlipidemia is a major risk factor for fatty liver, atherosclerosis, hyperviscosily, coronary artery disease and acute myocardial infarction. In recent years, the incidence of hyperlipidemia was gradually increased and showed younger trend. It has been a research hot point to study the etiology and pathogenesis of hyperlipidemia and develop a new drug reduced blood lipid. It is very important to prepare the animal model of hyperlipidemia for displaying the advantage of traditional Chinese medicine characteristic. However, the success of replicating animal model of hyperlipidemia is one of the key of research in experimental hyperlipidemia. The ideal animal model of hyperlipidemia should be similar to human disease, high repeatability, simple and high generalization. It will affect the reliability of the results and the accuracy of the whole experiment process to copy successfully animal models of hyperlipidemia. This review focused on the recent research progress on copying methods of animal models of experimental hyperlipidemia, which will provide reference and basis for the hypolipidemic developers who choose rationally and effectively replication methods of hyperlipidemia animal models.

[Leaching Toxicity and Bioaccessibility of Heavy Metals in MSWI Fly Ash with Various Particle Sizes].

Size fractionation and chemical composition of municipal solid waste incinerator (MSWI) fly ash were investigated. And the leaching efficiency of heavy metals was contrastively studied using toxicity characteristic leaching procedure (TCLP), European standard protocol (EN12457-2), sequential extraction procedure (SEP) and physiologically based extraction test (PBET) for different size-fractionated fly ash. The results indicated that the main compositing elements of fly ash were Ca, Si, Al, Mg, Fe, Na, K. 58.7% of fly ash particles were in the range of 38-106 µm and the amount in the<150 µm particle-size fraction accounted for more than 90% of in total, Cu, Pb and Cd mainly existed in the residual form with a minor amount of exchange fraction for any size-fractioned fly ash particles. TCLP result showed that leaching amounts of Zn, Cu and Pb, except for As and V, firstly increased and then decreased with the reduction of particle size. The leaching amount of Zn reached the highest value of 547 mg·kg-1 in the range of 38-106 µm, whereas the leaching amount of heavy metals exhibited a lower level for all size-fractioned fly ash particles. The extraction concentrations of Zn, Pb, Cu and As reached 3270, 339, 335 and 16.8 mg·kg-1 for the PBET tests, respectively, which were significantly higher than those of the TCLP. Therefore, heavy metals in MSWI fly ash had the potential bioavailability to human body.