Instruct: Identify the main category of the given Medrxiv paper based on its title.
Query: Effect of reduction in brain amyloid levels on change in cognitive and functional decline in randomized clinical trials: an updated instrumental variable meta-analysis
Cognitive enhancement: Effects of methylphenidate, modafinil and caffeine on latent memory and resting state functional connectivity in healthy adults
Spike mutations of the SARS-CoV-2 Omicron: more likely to occur in the epitopes
Total Infectomes Characterization of Respiratory Infections in pre-COVID-19 Wuhan, China
Artificial Intelligence Sepsis Prediction Algorithm Learns to Say "I don't know"
Sex Modifies the Effect of Genetic Risk Scores for Polycystic Ovary Syndrome on Metabolic Phenotypes
Quantitation of SARS-CoV-2 neutralizing antibodies with a virus-free, authentic test
Anti-microbial effect of filtered 222nm excimer lamps in a hospital waiting area
Standardized and optimized preservation, extraction and quantification techniques for detection of fecal SARS-CoV-2 RNA
VIKING II, a Worldwide Observational Cohort of Volunteers with Northern Isles Ancestry
Physical body experiences questionnaire simplified for active aging (PBE-QAG): Validation with Rasch measurement theory
Impact of individual-level characteristics and transmission mitigation behaviors on SARS-CoV-2 infection and seroprevalence in a large Northern California Bay Area cohort
Assessment of knowledge, attitude, and practices of Tuberculosis patients towards DOTs regimen in Jimma health center, Jimma zone, southwest Ethiopia
The Population Attributable Fraction (PAF) of cases due to gatherings and groups with relevance to COVID-19 mitigation strategies
Prevalence of COVID-19 in Iran: Results of the first survey of the Iranian COVID-19 Serological Surveillance program
Improved diagnosis of SARS-CoV-2 by using Nucleoprotein and Spike protein fragment 2 in quantitative dual ELISA tests
Danger signs and management of suspected severe malaria cases at community level and in referral health facilities: an operational study in the Democratic Republic of the Congo
Performance and Implementation Evaluation of the Abbott BinaxNOW Rapid Antigen Test in a High-throughput Drive-through Community Testing Site in Massachusetts
Examining the Association between the Gastrointestinal Microbiota and Gulf War Illness: A Prospective Cohort Study
Trait Mindful Nonreactivity and Nonjudgment Prospectively Predict of COVID-19 Health Protective Behaviors Across a Two-Month Interval in a USA Sample
Analytical sensitivity and effectiveness of different SARS-CoV-2 testing options
Socio-economic inequalities in adolescent mental health in the UK: multiple socio-economic indicators and reporter effects
Aspirin and NSAID use and the risk of COVID-19
Agent-Based Simulation of Covid-19 Vaccination Policies in CovidSIMVL
The COvid-19 Pandemic and Exercise (COPE) Trial: A multi-group randomized controlled trial comparing effects of an app-based, at-home exercise program to waitlist control on depressive symptoms
Vitamin D and COVID-19 Susceptibility and Severity in the COVID-19 Host Genetics Initiative: a Mendelian Randomization Study