Instruct: Identify the main category of the given Medrxiv paper based on its title.
Query: The Knowledge and Attitude of Physicians Regarding Vaccinations in Yerevan, Armenia: Challenges for COVID-19
Insomnia symptoms and risk of bloodstream infections: prospective data from the prospective population-based HUNT Study, Norway
Longitudinal protection following natural SARS-CoV-2 infection and early vaccine responses: insights from a cohort of community based dental health care professionals
Sex steroid hormones and risk of breast cancer incidence and survival: A two-sample Mendelian randomization study
Electrical Stimulation and Time to Radiographic Healing of Acute Fractures: A Systematic Review and Meta-Analysis
Dissecting heart age using cardiac magnetic resonance videos, electrocardiograms, biobanks, and deep learning
Can process mapping and a multi-site Delphi of perioperative professionals inform our understanding of system-wide factors that may impact operative risk?
Impact of the Covid-19 pandemic on the mental health and wellbeing of adults with mental health conditions in the UK: A qualitative interview study
Prior COVID-19 Infection and Antibody Response to Single Versus Double Dose mRNA SARS-CoV-2 Vaccination
Understanding COVID-19 trajectories from a nationwide linked electronic health record cohort of 56 million people: phenotypes, severity, waves & vaccination
Astrocyte biomarker signatures of amyloid-β and tau pathologies in Alzheimer's disease
Reconstructing the course of the COVID-19 epidemic over 2020 for US states and counties: results of a Bayesian evidence synthesis model
Strategies and action points to ensure equitable uptake of COVID-19 vaccinations: A national qualitative interview study to explore the views of undocumented migrants, asylum seekers, and refugees
The energy balance theory: an unsatisfactory model of body composition fluctuations
Risk of death following SARS-CoV-2 infection or COVID-19 vaccination in young people in England: a self-controlled case series study
Socio-economic inequalities in adolescent mental health in the UK: multiple socio-economic indicators and reporter effects
Unmasking Seasonal Cycles in Human Fertility: How holiday sex and fertility cycles shape birth seasonality
Patient reported outcome on endourethrotomy combined with Amplatz dilatation for treatment of incompletely obliterated posterior urethral stricture following pelvic trauma: Validation in the era of urethroplasty
The Impact of Early or Late Lockdowns on the Spread of COVID-19 in US Counties
Prevalence of RT-PCR-detected SARS-CoV-2 infection at schools: First results from the Austrian School-SARS-CoV-2 Study
Exploring human mixing patterns based on time use and social contact data and their implications for infectious disease transmission models
Pulmonary thromboembolism in patients after COVID-19 - predictive indicators for correct diagnosis
Air pollution exposure and mitochondrial DNA copy number in the UK Biobank
Excess risk and clusters of symptoms after COVID-19 in a large Norwegian cohort
Development of a core measurement set for research in degenerative cervical myelopathy: a study protocol (AO Spine RECODE-DCM CMS)
Effect of workplace infection control practices on workers' psychological distress: a large-scale cohort study during the COVID-19 second state of emergency in Japan