There are multiple definitions:

1. sarcoplasmic reticulum(English)

   • CIRC, DHPR, HAHT, JPH2, RyR, Tcap, jSR
   • Physiology, Myocyte / muscle

2. sinus rhythm(English)

   • NSR, CCV, DCCV, ECV, ivCCV, oCCV
   • Electrophysiology, Cardiology
   • https://doi.org…europace/eur406

3. sustained release(English)

   • XR
   • Pharmacology / pharmaceutics, Therapeutic approaches

4. saturation recovery(English)

   • MRI
   • Medical imaging

5. spin relaxation(English)

   • e.g., muon-SR
   • Medical imaging

6. systolic reversal(English)

   • DR, DT
   • Cardiology, Electrophysiology

7. sewing ring(English)

   • MP
   • Cardiology, Surgery
   • https://pubmed.…h.gov/22645863/

8. strain rate(English)

   • CSR, LSR, FT, CMR-FT
   • Cardiology, Medical imaging, Biophysics
   • https://doi.org…rad.2017.01.028

9. shear rate(English)

   • FMD
   • Vascular disease, Biophysics, Hemodynamics
   • https://doi.org…eart.00471.2010

10. stop rox(English)

    • SF, TFBS, tSNE, UMAP, VIPER
    • Transcription
    • https://doi.org…NAHA.120.049922

11. sex ratio(English)

    • skewing of the sex ratio towards males occurs in humans. The possible explanation for excess male births could be a preference for Y-bearing sperm at fertilization and/or selective elimination of female embryos during pregnancy
    • SRY, ZFY
    • Gender aspects, Embryology /reproduction, Pregnancy, Ratio-based metric
    • https://doi.org…bio.2021.100514

12. systematic review(English)

    • CQ
    • Medical publications

13. supine rest(English)

    • regular practice of this type of rest may cause improvement of impaired autonomic nerve function in type 2 diabetes mellitus patients
    • DM, HFnu, HRV, LFnu, LF/HF, T2DM, VMA
    • Diabetes, Therapeutic approaches
    • https://doi.org…bsp.v12i2.35425

14. salvage radiotherapy(English)

    • LRT, RTOG, mRTOG/LENT
    • Prostate, Radiotherapy /radiation
    • https://doi.org…ogy.2004.08.037

15. super-resolution(English)

    • refers to fluorescence microscopy
    • CET, CLEM, EM
    • Microscopy, Fluorescence, Nano-sciences
    • https://doi.org…m-090319-051546

16. satiety responsiveness(English)

    • refers to prospective relationships from appetite to adiposity measures
    • AEBQ, BEBQ, BMI, BMIz, CEBQ, EOE, EUE, FF, FR, SE
    • Adiposity, Nutrition
    • https://doi.org….1111/obr.13169

17. superior rectus [muscle](Latin)

    • SRM, LR-SR
    • Myocyte / muscle, Ophthalmology
    • https://doi.org…55/2019/5374628

18. secondary restraint(English)

    • ACL, BPTB, Lax-SR
    • Musculoskeletal system
    • https://doi.org…6/JBJS.16.01412

19. stenosis resistance(English)

    • aCBF, aMVR, CAD, CFD, CFR, FFR, MLD
    • Coronary circulation, Hemodynamics
    • https://doi.org…598-021-99065-7

20. superficial radial(English)

    • refers to reflex pathways from different cutaneous nerves in the hand and foot as linked to the cervical and lumbar spinal cord
    • SP
    • Neurology, Dermatology, Spine (or spinal cord), Reflex
    • https://doi.org…7/s002210100857

21. standard-risk(English)

    • EFS, EVAIA, HR, OS, SR, VACA, VAIA
    • Risk factor, Oncology, Chemotherapy
    • https://doi.org…CO.2008.16.5720

22. systemic reaction(English)

    • refers to immunotherapy injection or to field sting
    • BV, MVIT, VIT
    • Allergy, Asthma, Immunology
    • https://doi.org…1206(10)60552-2

23. steroid resistant(English)

    • may refer to a group of asthmatics who have persistent airway obstruction and immune activation despite treatment with high doses of systemic glucocorticoids
    • INS, SD, SPR, GCR
    • Hormone, Allergy, Asthma
    • https://doi.org…196705000-00050
    • https://doi.org….1998.tb00293.x

24. sphenoethmoidal recess(English)

    • AEA, MTA, PEA
    • ENT, Medical imaging
    • https://doi.org…ama2006-124.410

25. Sanguisorbae radix(Latin)

    • cGMP, NO, SRE
    • Hypertension, Experimental animal
    • https://doi.org…3390/nu15214510

26. surgical resection(English)

    • BCLC, HCC, RFA, TACE
    • Liver disease, Surgery
    • https://doi.org…876-020-01235-w

27. skeletonization resection(English)

    • refers to the hepatoduodenal ligament in casesa of hilar cholangiocarcinoma
    • Surgery, Liver disease, Oncology, Biliary tract
    • http://pubmed.n…h.gov/15062037/

28. surgical recurrence(English)

    • may refer to Crohn's disease
    • CD, CR, ER, POR
    • Prognosis, Surgery
    • https://doi.org…000000000003821

29. sit-and-reach [test](English)

    • BS, BS-SR, SR-TT, SR-VSR, TT, USR, VSR
    • Sports medicine, Spine (or spinal cord)
    • https://doi.org…ams.2006.10.003