Clinical Research Directory
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1001 clinical studies listed.
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Tundra lists 1001 Healthy clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.
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NCT07169630
PET Imaging of Phosphodiesterase-4 (PDE4) in Volunteers With Alzheimer Disease (AD) or Mild Cognitive Impairment (MCI)
Background: About 5 million adults in the United States have age-related brain disorders. These include Alzheimer disease (AD), mild cognitive impairment (MCI), and other dementias. The number of people with these disorders will likely increase as the population ages and life span increases. Inflammation is thought to play a role in AD and MCI. Researchers want to know if an enzyme called PDE4B increases inflammation in people with AD or MCI. Objective: To test whether medical imaging using a new radiotracer (\[18F\]PF-06445974) can measure PDE4B in the brains of people with AD or MCI. Eligibility: People aged 50 years and older with AD or MCI. Healthy volunteers are also needed. Design: Participants will have up to 5 clinic visits with 3 imaging scans of the brain. They will have be screened. They will have a physical exam with blood tests. This will include tests of their heart and nerve function, including memory. Participants will have 2 positron emission tomography (PET) scans. One will use a standard radiotracer. The other will use the study radiotracer. They will receive each tracer through a tube attached to a needle inserted into a vein. During the scan with the study tracer, participants will have a second tube inserted into a vein in the wrist; this tube will be used to draw blood during the scan. Participants will lie on a bed that slides into a doughnut-shaped machine. These visits will take about 6 hours each. Participants will have 1 magnetic resonance imaging (MRI) scan. They will lie on a bed that slides into a cylinder. This visit will take up to 2 hours....
Gender: All
Ages: 50 Years - 100 Years
Updated: 2026-07-14
1 state
NCT07686393
PET Imaging of Noradrenergic Transmission in the Brain
Background: Researchers have developed a new radioactive tracer (11C-ARMI). A tracer is a drug that attaches itself to other chemicals in the body and lights up so that the chemicals can be seen in imaging scans. The new tracer may be able to help them with many diseases, such as Alzheimer s disease and Parkinson s disease. Researchers want to test the new tracer in healthy people. Objective: To test a new tracer (11C-ARMI) during imaging scans of the brain and body in healthy people. Eligibility: Healthy people aged 18 years and older. They must have been screened under protocols 01-M-0254 or 17M0181. Design: All participants will have a positron emission tomography (PET)/computed tomography (CT) scan. Before the scan, they will have blood and urine tests and a test of their heart function. The tracer will be given through a tube attached to a needle inserted into a vein in the arm. They will lie on a padded bed that fits inside a doughnut-shaped machine; the machine uses x-rays to create images of the inside of the body. Some participants will have a PET/CT scan of their whole body. They will need only 1 visit. Some participants will have a PET/CT scan of only their brain. They will have up to 2 visits. On the second visit, they will have a magnetic resonance imaging (MRI) scan of the brain. For the MRI, they will lie on a table that slides into a cylinder. The MRI uses magnetic fields to create images of the inside of the body. Participants will receive a follow-up call to check on their well-being after their PET/CT scans.
Gender: All
Ages: 18 Years - 105 Years
Updated: 2026-07-14
1 state
NCT03288220
Influence of Brain Oscillation-Dependent TMS on Motor Function
Background: When people have a stroke, they often have difficulty moving their arms and hands. Transcranial magnetic stimulation (TMS) can improve how well people with and without stroke can move their arms and hands. But the effects of TMS are minor, and it doesn t work for everyone. Researchers want to study how to time brain stimulation so that the effects are more consistent. Objective: To understand how the brain responds to transcranial magnetic stimulation so that treatments for people with stroke can be improved. Eligibility: Adults ages 18 and older who had a stroke at least 6 months ago Healthy volunteers ages 50 and older Design: Participants will have up to 5 visits. At visit 1, participants will be screened with medical history and physical exam. Participants with stroke will also have TMS and surface electromyography (sEMG). For TMS, a brief electrical current will pass through a wire coil on the scalp. Participants may hear a click and feel a pull. Muscles may twitch. Participants may be asked to do simple movements during TMS. For sEMG, small electrodes will be attached to the skin and muscle activity will be recorded. At visit 2, participants will have magnetic resonance imaging (MRI). They will lie on a table that slides into a metal cylinder in a strong magnetic field. They will get earplugs for the loud noise. At visit 3, participants will have TMS, sEMG, and electroencephalography (EEG). For EEG, small electrodes on the scalp will record brainwaves. Participants will sit still, watch a movie, or do TMS. Participants may be asked to have 2 extra visits to redo procedures.
Gender: All
Ages: 18 Years - 120 Years
Updated: 2026-07-14
1 state
NCT07482644
Efficacy and Safety of an Essential Oil-Based Product System for Immune Support
This randomized, double-blind, placebo-controlled clinical trial will evaluate the safety and efficacy of an essential oil-based product system for immune support in healthy adolescents and adults aged 18-45 years. Participants will be randomized to receive aromatic, topical, internal, or combined use of the investigational product or matching placebo for 30 days. The aromatic intervention consists of overnight diffusion, the topical intervention consists of diluted application to specified areas prior to bedtime, and the internal intervention consists of oral capsule administration twice daily. Study visits will occur at baseline and at the end of the 30-day intervention period. Primary outcomes include changes in immune-related biomarkers, including complete blood count, comprehensive metabolic panel, salivary immunoglobulin A (IgA), and inflammatory cytokines (IL-6, TNF-α, IL-10). Epigenetic markers will also be evaluated. Secondary outcomes include validated subjective assessments of immune status and overall well-being, as well as evaluation of safety and tolerability. The study includes an adaptive design with interim analysis to assess enrollment and study continuation parameters.
Gender: All
Ages: 18 Years - 45 Years
Updated: 2026-07-14
1 state
NCT04170244
Skin Microbial Ecology in Atopic Dermatitis
Everybody's skin has bacteria that normally lives on it. Previous research has shown that people with eczema (or atopic dermatitis \[AD\]) have much higher concentrations of a certain bacteria (S. aureus), especially when their disease is active but little is known about the role that this bacteria plays in psoriasis (i.e. disease severity, biomarkers and skin barrier function). The overarching purpose of this longitudinal study is to understand how the abundance of skin S. aureus (and several commensal bacteria) change as a consequence of standard of care treatment in the URMC dermatology clinics. Other assays and biospecimens will also be collected to address a number of questions.
Gender: All
Ages: 13 Years - Any
Updated: 2026-07-14
1 state
NCT07701603
Effects of Blood Gas Perturbations
In this study, the effects of blood gas perturbations on neuromuscular function of the diaphragm and lower limbs at rest and during exercise will be investigated.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2026-07-14
NCT03458780
Yellow Fever Immune Response at Single Cell Resolution
The immune system is composed of diverse cell types with different functions that act together in order to defend against infection. This pilot study will test a new technology for studying these many different cell types at very large numbers at the level of individual cells. This method will then be used to identify the cell types and functions important for the immune response to the highly protective yellow fever vaccine, which will improve our understanding of effective vaccine features.
Gender: All
Ages: 18 Years - 59 Years
Updated: 2026-07-14
1 state
NCT07619443
A Clinical Study of MK-7262 and Enlicitide in Healthy Participants (MK-7262-003)
The goal of this study is to learn what happens to a single dose of enlicitide over time in a healthy participant's body when the participant is given a single dose of MK-7262 and what happens to a single dose of MK-7262 over time in a healthy participant's body when the participant is given a single dose of enlicitide.
Gender: All
Ages: 19 Years - 55 Years
Updated: 2026-07-13
1 state
NCT06254898
Use of Incentives for Stressful Medical Procedures
The goal of this clinical trial is to learn about the use of incentives in pediatric patients requiring medical procedures. The main questions it aims to answer are: Are incentives effective at reducing pediatric anxiety for medical procedures? What is the best way to use incentives with pediatric populations requiring medical procedures? Participants will be provided support in preparation for their procedure and during the procedure by a child life specialist and might receive an incentive prize after their procedure. Participants distress levels during the procedure will be observed and they will be asked to rate their anxiety on a visual analog scale. Researchers will compare the anxiety of those who did or did not receive an incentive after their procedure to see if incentives reduced procedural anxiety.
Gender: All
Ages: 6 Years - 17 Years
Updated: 2026-07-13
1 state
NCT05401227
Glutamatergic Mechanisms: Aim2
In the present study, 120 healthy volunteers (HV) will be randomized to one of three ketamine-induced pharmacoBOLD (phBOLD) arms: low, medium, and high. Within each ketamine arm, participants will be randomized to 4 days of "study drug" \[TS-134 (1st 20 participants) or XT (remaining 100 participants)\] or placebo in a 5:3 ratio (25 study drug:15 placebo per arm). During the study, each participant will undergo a Screening Period (up to 31 days), a 4-day Treatment Period, and a total of two phBOLD sessions: a first session at Baseline and a second session on Day 4 of the Treatment Period, conducted at least 7 days apart, and a follow up visit.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2026-07-13
1 state
NCT04589208
Glutamatergic Mechanisms of Psychosis and Target Engagement (SA1)
50 healthy volunteers (HV) will participate in 2 identical ketamine-induced pharmacoBOLD (phBOLD) sessions at least 7 days apart. On both days, clinical assessments will be performed following removal of the subject from the scanner. HV will be discharged home after clearance by the study physician. This study will assign ketamine doses in successive 10 subject cohorts. The ketamine dose for the 1st cohort will start at 0.08 mg/kg. For subsequent cohorts, the bolus will be successively reduced or increased by 0.02 mg/kg (n=10/dose) to determine the lowest dose of ketamine that still produces a robust phBOLD response. The study will be subject and rater blind, i.e. subjects and raters, will be blinded to the treatment (ketamine dose) group. The study physician will be aware of the ketamine dose, and ketamine dose will be the same for both sessions. Subjects will not be told what the exact ketamine dose they will receive, but it will be based on their weight and will be no higher than 0.08 mg/kg.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2026-07-13
1 state
NCT05357261
Deliver-EE: Evaluating Effects of Meal Delivery
This study will randomly assign 2,300 older adults on waiting lists at fourteen Meals on Wheels programs in Florida, Illinois, Maryland, Tennessee, Texas, North Carolina, South Carolina, and California into two groups who will receive: (a) daily delivery of meals, five days a week or (b) a shipment of 10 frozen meals, every two weeks. Researchers will examine participants' Medicare claims to understand if differences in healthcare utilization occur between the two groups within six months after they start receiving meals. Researchers will also ask participants questions prior to receiving meals, and again at three months, to understand how meals impact their ability to obtain food, their feelings of loneliness, and their overall quality of life. The primary study outcome will be the ratio of days spent in institutional settings (i.e., hospital, nursing home) in the six months after participants begin receiving meals. The secondary outcomes include the ratio of days spent in institutional settings in the three months after participants begin receiving meals, food insecurity, subjective isolation/loneliness, and health-related quality of life. The team will also examine differences in dietary intake between the two groups as an exploratory outcome.
Gender: All
Ages: 66 Years - Any
Updated: 2026-07-10
8 states
NCT01130545
Imaging Techniques in MRI
Background: \- Magnetic resonance imaging (MRI) scans must be performed according to specified sets of parameters that provide optimal images of each organ and each area of the body. These scanning parameters are often specific to the institution or organization at which they are employed, and may also depend on the manufacturer of the MRI scanning equipment. Because MRI scanning equipment is always being updated and upgraded, researchers are interested in developing new and optimized scanning parameters for MRI scans. Objectives: \- To improve current methods and develop new techniques for magnetic resonance imaging. Eligibility: * Individuals 18 years of age and older who are either volunteers or current NIH protocol participants. * Participants must not have any medical history factors (e.g., extreme claustrophobia, history of metal implants) that would prevent them from receiving MRI scans. Design: * Participants will have at least one MRI scan that will last from 20 minutes to 2 hours (most scans will last between 45 and 90 minutes). The total time commitment for most visits will be approximately 4 hours from start to finish. * Some MRI techniques require standard monitoring equipment or specific procedures during the scanning, such as an electrocardiogram. * Participants will have blood samples taken at the time of the scan. Some MRI studies will require the use of a contrast agent that will be administered during the scan. * Volunteers may be asked to return for additional MRI scans over the course of a few years. Follow-up scans may be done on the same part of the body or on different parts of the body. No more than one MRI scan will be performed in any 4-week period for this protocol.
Gender: All
Ages: 18 Years - 100 Years
Updated: 2026-07-10
1 state
NCT05841238
A Multiple Dose Study of LY3502970 in Healthy Overweight and Obese Participants
The main purpose of this study is to evaluate how much LY3502970 gets into the bloodstream and how long it takes the body to eliminate when administered orally as tablet and capsule formulations along with effect of food on LY3502970 in healthy overweight and obese participants. The study will also evaluate the safety and tolerability of LY3502970 in these participants. The study is conducted in two parts (part A and B) and will last up to 135 days including the screening period.
Gender: All
Ages: 18 Years - 70 Years
Updated: 2026-07-10
3 states
NCT07013487
A Study to Evaluate V181 Dengue Vaccine in Healthy Participants 2 to 17 Years of Age (V181-005/MOBILIZE-1)
The purpose of this study is to demonstrate that V181 is safe and well tolerated, elicits an immune response, and reduces the frequency of virologically confirmed dengue (VCD) of any severity, due to any of the 4 dengue serotypes, regardless of dengue serostatus at baseline in children 2 to 17 years of age.
Gender: All
Ages: 2 Years - 17 Years
Updated: 2026-07-10
18 states
NCT07665216
Chatbot Intervention Effects on Resting-State Brain Function in Anhedonia
The main aim of the present study is to investigate the effects of a Motivational Interviewing-based artificial intelligence chatbot on resting-state brain function in college students with elevated anhedonia and depressive symptoms. The study will use a randomized active-control intervention design with pre- and post-intervention resting-state functional magnetic resonance imaging assessments.
Gender: All
Ages: 18 Years - 40 Years
Updated: 2026-07-09
1 state
NCT06707207
Predicting Future Errors During Skill Performance
Background: Many tasks people do every day require a series of individual movements. Control over these movements is called motor skills. But even highly skilled people can make mistakes. Researchers have found that they can predict when a person will make a mistake 0.1 second before it happens. Now, they want to find out if they can increase that time up to 1 second-long enough to warn the person and prevent the mistake. Objective: To see if motor skill errors can be detected up to 1 second before they occur. Eligibility: Right-handed healthy adults aged 18 to 35. Design: Participants will have 2 to 5 study visits. Each visit will be 1 to 2 hours. They will have a physical and neurological exam. They will have 1 or 2 magnetic resonance imaging (MRI) scans. They will lie on a table that slides into a large cylinder. The MRI uses strong magnets to capture images of the inside of the body, including the brain. They will have another scan, called magnetoencephalography (MEG). Small metal disks attached to wires will be taped to their head. Participants will sit in a padded chair with their head inside of a helmet. The helmet will not cover their eyes or face. Participants will perform a series of typing tasks on a keyboard. They will have short breaks between each round. Their head movements will be tracked, and their eye and finger movements will be videotaped.
Gender: All
Ages: 18 Years - 35 Years
Updated: 2026-07-09
1 state
NCT07663019
Chatbot Intervention Effects on Belief Updating in Anhedonia
The main aim of the present study is to investigate the effects of a Motivational Interviewing-based artificial intelligence chatbot on belief updating in college students with elevated levels of depression and anhedonia by combining a randomized active-control intervention design with pre- and post-intervention behavioral belief updating task assessments.
Gender: All
Ages: 18 Years - 40 Years
Updated: 2026-07-09
1 state
NCT07693231
A Study to Test How Well Different Doses of BI 3034701 Are Tolerated by Japanese Healthy People and Japanese People With Obesity or Overweight
Part 1: To investigate safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of BI 3034701 in Japanese male and female participants with body mass index (BMI) ≥27.0 kg/m² or more following subcutaneous administration of multiple rising doses over 16 weeks. Part 2: To investigate safety, tolerability, and PK of BI 3034701 in Japanese male and female healthy participants with BMI ≥23.0 to \<27.0 kg/m² following subcutaneous administration of multiple rising doses over 7 weeks.
Gender: All
Ages: 18 Years - 64 Years
Updated: 2026-07-09
NCT07671131
Chatbot Intervention Effects on Emotional Arousal in Anhedonia
The main aim of the present study is to investigate the effects of a Motivational Interviewing-based artificial intelligence chatbot on affective arousal in college students with elevated levels of depression and anhedonia by combining a randomized active-control intervention design with pre- and post-intervention emotional video task assessments during fMRI.
Gender: All
Ages: 18 Years - 40 Years
Updated: 2026-07-09
1 state
NCT07563894
Relative Bioavailability and Impact of Rabeprazole for PF-07799933, Food-Effect for PF-07799933 and PF-07799544
The purpose of this study is to evaluate the relative bioavailability (rBA) of the Form 2 film-coated tablet of PF-07799933 intended for use in future studies compared to the current Form 1 tablet of PF-07799933 used in Phase 1 studies. Additionally this study will also evaluate the effect of a high-fat meal on the plasma pharmacokinetics (PK), i.e, the rBA compared to overnight fasting, of PF-07799933 and PF-07799544 following concurrent single-dose oral administration of Form 2 film-coated tablet formulation of PF-07799933 with PF-07799544. Finally, this study will also assess the impact of a proton pump inhibitor (a type of acid reducing agent) on PF-07799933 PK of the Form 2 film-coated tablet formulation. These data will be used to inform administration of PF-07799933 and PF-07799544 with food and acid reducing agents in future clinical trials.
Gender: All
Ages: 18 Years - 65 Years
Updated: 2026-07-09
1 state
NCT07665242
Chatbot Intervention Effects on Social and Monetary Incentive Processing in Anhedonia
The main aim of the present study is to investigate the effects of a Motivational Interviewing-based artificial intelligence chatbot on social incentive processing in college students with elevated levels of depression and anhedonia by combining a randomized active-control intervention design with pre- and post-intervention Social Incentive Delay Task assessments during fMRI.
Gender: All
Ages: 18 Years - 40 Years
Updated: 2026-07-09
1 state
NCT07160244
BEATRIX: A Study to Learn About a Group B Streptococcus Vaccine in Healthy Pregnant Women and Their Babies
BEATRIX (group B strEptococcus mATeRnal and Infant VaX study) The purpose of this study is to learn about the safety and how the group B streptococcus (GBS) vaccine works in pregnant women and their babies. This study is seeking healthy pregnant participants: * aged 49 or younger who can join. * between 24 and 36 weeks of gestation ("Gestational age" is a medical term used to describe how far along your pregnancy is) * had a fetal ultrasound examination performed with no major fetal abnormalities observed * documented negative for HIV, syphilis and Hepatitis B All participants in this study will receive only 1 shot in an arm. This could either be a group B streptococcus 6-valent polysaccharide conjugate vaccine (GBS6) or placebo. Placebo is an inactive substance used in the study for comparison purposes; in this study, the placebo injection will be saline (saltwater). The pregnant participants may take part in this study for a maximum of 14 months (6 months after delivery) , and their babies for about 12 months after they are born. The pregnant participants will need to visit the research site at least 3 to 4 times with some visits permitted to occur over the telephone. A subset of infants will be asked to take part in the study for up to 19 months. The subset will receive diphtheria toxoid-containing vaccine and/or pneumococcal vaccine following each country's standard immunization plan and have blood drawn 1 month after completion of the primary and/or toddler (booster) doses.
Gender: All
Ages: 1 Day - 49 Years
Updated: 2026-07-09
69 states
NCT07511855
Stress-buffering and Sleep Disturbance-resilient Effects of a Dual Bifidobacterium Longum Combination Under Short-term Travel
This study aims to evaluate the effects of a dual Bifidobacterium longum probiotic formulation (dipro-O and dipro-X) on sleep quality, stress responses, and gut microbiota stability in healthy adults during short-term travel. Using a randomized, double-blind, placebo-controlled design, the study investigates whether probiotic supplementation can enhance sleep resilience, buffer stress, and modulate microbiome and physiological responses under travel-related environmental changes.
Gender: All
Ages: 25 Years - 50 Years
Updated: 2026-07-09
1 state