There are multiple definitions:

1. renin-angiotensin system(English)

   • RAAS
   • Hypertension

2. renal artery stenosis(English)

   • common cause of renovascular hypertension in adults, excepted younger women
   • PTA, FMD, RRI
   • Nephrology, Hypertension, Vascular disease
   • https://doi.org…jnl-2019-316164
   • https://doi.org…nostics13101687

3. reticular activating system(English)

   • a network of neurons located in the brain stem that project anteriorly to the hypothalamus to mediate behavior, as well as both posteriorly to the thalamus and directly to the cortex for activation of awake, desynchronized cortical EEG patterns. Connects the brainstem to the cortex, and controls cognitive processes such as attention, learning, memory, wakefulness, and sleep-wake transitions
   • EEG, ACh, DBS, MLR, PPT, SNc
   • Neurons, Brain (dys)function, Behavior(al science), Cognitive function, Memory, Circadian rhythm
   • https://www.sci…of-neuroscience
   • https://doi.org…nana.2016.00109

4. Russian Academy of Sciences(English)

   • KNAW, NYAS
   • Organizations (scientific)
   • http://www.ras.ru/

5. retrovirus-associated DNA sequence(English)

   • the RAS superfamily contains 36 members in humans and includes three main RAS isoforms: HRAS, KRAS and NRAS, which are the most frequently mutated in human cancers
   • HRAS, KRAS, NRAS, SHOC2
   • Virology, Genomics, Oncology
   • https://doi.org…586-022-04838-3

6. restrictive allograft syndrome(English)

   • novel form of chronic lung allograft dysfunction after transplantation
   • BOS, CLAD
   • Transplantation, Pulmonology
   • https://doi.org…lun.2011.01.712

7. rapid atrial swirl(English)

   • defined as the ultrasound appearance of turbulence entering the right atrium from the superior vena cava immediately (subjectively estimated within 2 s) after the saline flush of the CVC distal port and migrating towards the right ventricle
   • CVC, RA, RAS, RV, US
   • Cardiology

8. robotics and autonomous system [technologies](English)

   • GNSS, IoS
   • Robotics
   • https://doi.org…OC.2018.2805267

9. rat sarcoma [virus](English)

   • a protein superfamily of small GTPases. Members of the superfamily are divided into families and subfamilies based on their structure, sequence and function. The five main families are Ras, Rho, Ran, Rab and Arf GTPases. The Ras family itself is further divided into 6 subfamilies: Ras, Ral, Rap, Rheb, Rad and Rit. Also denoted as Ras
   • GPT, RAC, RAL, RBD, RHO
   • Molecular biology
   • https://doi.org…1-62703-791-4_1

10. rhythmic auditory stimulation(English)

    • can influence movement during straight line walking and direction transition in individuals with Parkinson disease
    • DGI, EP, FOGQ, PD, UPDRS
    • Auditory system, Parkinson, Gait/walking
    • https://doi.org…545968311401627