· AIM:To investigate the prevalence of juvenile myopia and factors affecting its occurrence in Linxia Prefecture.· METHODS:Totally 8 683 juvenile students who were 6-18 years old were extracted as respondent with stratified cluster sampling method.The eyesight,diopter and axial length were detected,and the gender,age,ethnicity,eye behavior were collected by self-made questionnaire.· RESULTS:The prevalence of myopia was 42.80％.The myopic rates of all ethnic groups were as follows:Tibetan Nationality:59.05％,Han Nationality:46.71％,Dongxiang Nationality:46.36％,Tu Nationality:45.24％,Sala Nationality:41.30％,Baoan nationality:40.61％,Hui Nationality:31.97％.Myopia rate between each ethnic groups had statistical difference (x2 =44.08,P=0.007).Multivariate analyses revealed that outdoor activities during the break was the protect factor for myopia;age,using electronic products on weekends and holidays,using the same lighting in room while studying were risk factors for myopia.· CONCLUSION:The prevalence of myopia increase with age in Linxia.The prevalence in different ethnic groups is different.Education department and family should make joint efforts to increase the outdoor time,improve the environment for teenagers to reduce the occurrence and development of myopia.

OBJECTIVETo evaluate the value of blood lactic acid (BLA) as a predictor for the severity and prognosis of neonatal shock.

METHODSA total of 326 neonates with shock were enrolled and divided into three groups based on the severity, namely mild group (n=147), moderate group (n=105), and severe group (n=74). BLA level was measured during and early after (about 6 hours later) fluid resuscitation, and lactate clearance rate (LCR) was calculated. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of BLA in neonatal shock.

RESULTSBLA level was high in all subjects prior to treatment, and was highest in the severe group and lowest in the mild group (P<0.01). BLA level was significantly higher among patients with septic shock than among those with hypovolemic, cardiogenic, and asphyxiating shock (P<0.05). BLA level was significantly reduced in patients in recovery after treatment (P<0.05). Mortality was significantly lower in patients with BLA level ≤4 mmol/L or LCR ≥10% than in those with BLA level >4 mmol/L or LCR <10% (P<0.01). BLA at 11.15 mmol/L had 100% sensitivity and 96.8% specificity in predicting severe shock. BLA at 10.65 mmol/L had 88.9% sensitivity and 74.1% specificity in predicting the prognosis (survival or dead) of newborns with shock.

CONCLUSIONSIn neonates with shock, arterial BLA level increases as the disease severity increases and is associated with prognosis, so it is a useful predictor of the severity and prognosis of neonatal shock.