Abstract Digitalization provides adolescents with a variety of ways to entertain and socialize, but the new media environment may pose certain risks to their mental health. The paper expounds the relationship between social media exposure and social appearance anxiety, as well as the mediating role of social comparison. It also would enhance media health literacy as a potential solution. The aim is to clarify the formation mechanism of social appearance anxiety among adolescents in the digital media environment and provide governance recommendations to reduce social appearance anxiety among adolescents, so as to better help adolescents to resist risks and grow up healthy in the digital age.

Objective To explore the high risk factors of stillbirth. Methods 176 cases of stillbirth were collected in the Obstetrics and Gynecology Hospital of Fudan University from January 1st, 2010 to December 31st, 2016. All cases were analyzed retrospectively, including general profile, high risk factors of stillbirth in different years and pregnancy periods. Results (1) The incidence of stillbirth was 0.178%(176/98 785). Stillbirth occured mostly at 28-28+6gestational weeks (10.8%,19/176), and the second peak was 29-29+6weeks(10.2%,18/176),while the third common period was 37-37+6weeks(9.1%,16/176).After 39 weeks,it maintained at a low level.(2)The top 5 high risk factors of stillbirth were infection (18.2%,32/176), unexplained (13.6%,24/176), hypertention disorders in pregnancy (13.1%, 23/176), umbilical cord torsion(12.5%,22/176)and fetal malformations(10.2%,18/176).(3)From 2010 to 2012,the top 3 high risk factors were unexplained, the umbilical cord torsion and infection, while hypertention in pregnancy,infection and fetal malformation became the top 3 high risk factors after 2013.(4)Early stillbirth (20-27+6weeks)accounted for 21.6%(38/176);and unexplained(47.4%,18/38),fetal edema(13.2%,5/38), infection(13.2%,5/38),umbilical cord torsion(5.3%,2/38)were the top 4 high risk factors.Late stillbirth(≥28 weeks)accounted for 78.4%(138/176),with infection(19.6%,27/138),hypertention in pregnancy(15.9%, 22/138), umbilical cord torsion (14.5%,20/138) and fetal malformation(12.3%,17/138)being the top 4 high risk factors. Conclusions More attention should be paid to maternal complications, especially infection and hypertension in pregnancy. Antenatal fetal monitoring, timely termination of pregnancy, standard management of stillbirth and looking for the causes may help reduce the incidence of stillbirth.

BACKGROUND:Aging is associated with increased susceptibility to cardiovascular disease,and mitochondrial dysfunction plays a key role in the pathogenesis of cardiovascular disease.Regular physical activity is beneficial to cardiovascular health and can prevent and treat chronic heart disease.However,the specific mechanism of mitochondria in the protective effect of exercise on the aging heart has not yet been clarified. OBJECTIVE:To explore the effect of aerobic exercise on cardiac pathological remodeling in aging rats and to investigate the possible mechanism of mitochondrial quality control system. METHODS:Sixty Wistar rats were randomly divided into young sedentary group(6 months old),old sedentary group(20 months old)and old exercise group(20 months old)with 20 rats in each group.Rats in the young sedentary and old sedentary groups were fed in cages for 12 weeks,while those in the old exercise group underwent moderate-intensity aerobic treadmill exercise(60%of the maximal running speed,slope 0°,60 minute per day,5 days per week)for 12 weeks.After the experiment,the heart was extracted for relevant indicator tests. RESULTS AND CONCLUSION:Cardiac morphology and myocardial histopathology:compared with the young sedentary group,the rats in the old sedentary group presented with concentric cardiac hypertrophy,myocardial fibrosis,myocardial cell apoptosis and loss,and cardiac diastolic dysfunction(P＜0.05);compared with the old sedentary group,animals in the old exercise group showed reduced myocardial fibrosis and apoptosis rates,increased cell numbers,improved cardiac function(P＜0.05),and a transition in cardiac phenotype from pathological to physiological hypertrophy.Mitochondrial function:compared with the young sedentary group,the generation rate of mitochondrial hydrogen peroxide increased(P＜0.05),respiration rate and respiratory control ratio of state 3 and state 4 decreased(P＜0.05),activities of respiratory chain complexes Ⅰ,Ⅱ and Ⅳ decreased(P＜0.05),mitochondrial calcium retention capacity decreased(P＜0.05),and mitochondrial permeability transition pore opening increased(P＜0.05)in the old sedentary group.Compared with the old sedentary group,all of the above indicators were significantly improved in the old exercise group(P＜0.05).Mitochondrial quality control:compared with the young sedentary group,mitochondrial biogenesis decreased(P＜0.05),mitophagy activity increased(P＜0.05),mitochondrial fusion reduced(P＜0.05),and fission raised(P＜0.05)in the old sedentary group;compared with the old sedentary group,mitochondrial biogenesis and mitophagy activity increased(P＜0.05),mitochondrial fusion raised(P＜0.05)and fission decreased(P＜0.05)in the old exercise group.To conclude,regular aerobic exercises exert cardioprotective effects in aging rats by regulating the mitochondrial quality control system,thus reversing pathological cardiac remodeling and improving cardiac function.