The aim of this study is to investigate the effects of screen use within one hour before bedtime on sleep quality and cognitive function in medical graduate students, and to verify the mediating effect of sleep quality between the two. The study adopted a cross-sectional observational design and planned to enroll 508 full-time medical graduate students. The primary endpoints were evaluated using the Pittsburgh Sleep Quality Index (PSQI) and standardized cognitive tests (N-back, ANT, etc.), while secondary endpoints included insomnia severity, anxiety/depression regulation, gut microbiota diversity, and the interaction between physical activity and sleep. Data collection includes questionnaire surveys (PSQI, ISI, GAD-7, etc.), cognitive task testing, and analysis of gut microbiota samples. The final result will provide scientific basis for improving the sleep and cognitive health of medical graduate students.

1. Inclusion criteria:

   1. Full time medical graduate student at Southern Medical University
   2. Age ≥ 18 years old

2. Exclusion criteria:

   1. Have taken the following medications within the past month: antibiotics, probiotics, sleeping pills, laxatives, or intestinal cleansers, etc;
   2. Serious gastrointestinal diseases (inflammatory bowel disease, Crohn's disease, gastric cancer, etc.);
   3. Recently (within one month) experienced major life events (such as the death of a relative, surgery);

medical postgraduate

论文