Objective To evaluate the effects of different concentrations of sevoflurane on the cognitive function in neonatal rats.Methods Twenty-four neonatal Sprague-Dawley rats of both sexes,aged 7 days,weighing 12-16g,were randomly divided into high concentration sevoflurane group (group Sev1),low concentration sevoflurane group (group Sev2) or control group (group C),with 8 rats in each group.Sev1 and Sev2 groups were exposed to 2％ and 4％ sevoflurane for 6h,respectively,and C group inhaled gas mixture composed of 30％ oxygen.At 2 and 8 weeks after exposure to sevoflurane,cognitive function was assessed using the open field test and Morris water maze test.Results In the open field test,no significant differences were observed among the three groups (P ＞ 0.05).Morris water-maze test showed that the escape latency was significantly prolonged,and the frequency of crossing the original platform and the time spent in the third quadrant were decreased at 2 weeks after exposure to sevoflurane in Sev1 group and at 2 and 8 weeks after exposure to sevoflurane in Sev2 group as compared with group C (P ＜ 0.05).Morris water-maze test showed that the escape latency was significantly prolonged,and the frequency of crossing the original platform and the time spent in the third quadrant were decreased at 2 and 8 weeks after exposure to sevoflurane in Sev2 group compared with Sev1 group (P ＜ 0.05).Conclusion Exposure to 4％ and 2％ sevoflurane for 6h both can induce cognitive decline and the decreasing effect is enhanced with the increasing concentration in the neonatal rats.

Objective This paper analyzed the characteristics and changes in the disease spectrum of internal medicine inpatients of a tertiary hospital in Zhongshan City.It aimed to explore the evolving trends in disease ranking and treatment charac-teristics to provide a scientific basis for enhancing hospital management.Methods This paper selected 26 053 patients dis-charged from the internal medicine department of the tertiary hospital in Zhongshan City between January 1,2018,and December 31,2022.A retrospective analysis was used to classify these patients by ages,hospitalization date,and relative weight.Results In the past five years,those discharged patients showed no significant increase in the number,but a significant increase in age and ase Mix Index(CMI).Conclusion Since the outbreak of COVID-19,intractable inpatients in the hospital has steadily in-creased in number each year,while the diseases spectrum remains stable.The CMI of circulatory system,respiratory system,and nervous system diseases is relatively high.As key tricky components of internal medicine,these sub-specialties should concentrate on enhancing diagnostic and treatment capabilities as well as service quality to offer improved healthcare services to the public.