Objective To investigate the degree of retinal development in preterm infants. Methods Flash electroretinography (ERG) was performed on 25 healthy preterm infants and 25 full-term ones, and the response of rod cells and cone cells and maximal mixed responses were recorded. The delitescence and amplitudes of a- and b-waves and the ratio of amplitudes of b-/a-wave of maximal responses were analyzed. Results Compared with the full-term infants, The delitescence of responses of rod cells in preterm infants was statistically longer (.t=11.007,P.=0.000) but without any significant changes of amplitudes (.t=1.836,P.=0.069); statistically longer delitescence (.t=2.44, P=0.010; (t=10.800,)P.=0.000) and lower amplitude (.t=5.804,P=0.000; t=5.809,P.=0.000) of a- and b-wave of maximal response were found in preterm infants group. In the response of cone cells, there were significant differences of the delitescence (.t=4.444,P.=0.000) and amplitude (.t=3.819,P.=0.000)of a-wave and delitescence of b-wave(.t=2.850,P.=0.005) between the two groups, and no statistical difference of amplitude of b-wave (.t=0.486,P.=0.628) between the two groups. The ratio of amplitudes of b-/a-wave of the maximal mixed response was not significantly different between the two groups ((.t=1.142,)P.=0.256). Conclusions The development of retinal function is slower in preterm infants than that in full-term ones.

Objective To perform the ligand-based computer-aided drug design and construct the pharmacophore model of(1,3)-β-D-Glucan Synthase(GS)small molecule inhibitors.Method Six small molecules with diverse structures and good inhibitory activity were selected to construct the training set.The HipHop algorithm in Catalyst pharmacophore generation module was utilized to construct the pharmacophore models.The pharmacophore models were evaluated by constructed Decoy-set 3D database.Results Pharmacophore 02 has a good enrichment factor,sensitivity and specificity parameters.Pharmacoph-ore model validation with Decoyset 3D database proved that the model has good distinguishing capability.Conclusion The pharmacophore model of GS small molecule inhibitors was constructed and tested.It will provide valuable information for de-sign and discovery of novel small molecule GS inhibitors.

Objective:To explore the prevalence of sleep problems among residents in the city of Ruian during the outbreak of novel coronavirus pneumonia(COVID-19),and to investigate whether the presence of sleep prob-lems was related to the infection of COVID-19.Methods:Totally 4 810 community residents(1116 residents tested positive for COVID-19 and 3 694 residents tested negative for COVID-19)were chosen by stratified convenience sampling.All participants were assessed with the Sleep Self-Rating Scale(SRSS,total score ≥23 SRSS screen-pos-itive),Generalized Anxiety Scale(GAD-7,total score ≥5 GAD-7 screen-positive)and 9-item Patient Health Ques-tionnaire(PHQ-9,total score ≥5 PHQ-9 screen-positive).Results:The screen-positive rates of SRSS,GAD-7 and PHQ-9 were 30.5％,33.7％and 27.2％,respectively.Logistic regression analysis showed that the infection of CO-VID-19 was significantly associated with the SRSS screen-positive(OR=1.73,95％CI:1.48-2.03),after con-trolling for the confounding variables of gender,age group,GAD-7 screen-positive and PHQ-9 screen-positive.Conclusion:The prevalence of sleep problems was higher in the residents tested positive for COVID-19 than in those tested negative for COVID-19.The occurrence of sleep problems may be directly associated with the infection of COVID-19.