Life and health

Felis

Felis is a genus of small cats in Felidae containing the wildcats, jungle cat, sand cat, black-footed cat, and the domestic cat Felis catus, descended from Felis silvestris lybica; the Domestic Cat lineage arose about 3.4 million years ago.

Félix d'Hérelle

Félix d'Hérelle (1873–1949) was a French-Canadian microbiologist who discovered the bacteriophage, a virus that kills bacteria, reported it in 1917, and first used it to treat dysentery patients in 1919.

Félix Dévé

Félix Augustin Dévé (1872–1951) was a French physician and hospital doctor in Rouen, regarded as the great specialist of echinococcosis, a parasitic disease causing hydatid cysts.

Felix Ehrlich

Felix Ehrlich (1877–1942) was a German biochemist at the Institut für Zuckerindustrie in Berlin who identified the Ehrlich pathway of fusel alcohol formation in yeast.

Felix Eugen Fritsch

Felix Eugen Fritsch (1879–1954) was a British botanist, the leading British authority on freshwater algae and author of The Structure and Reproduction of the Algae.

Felix G. Fleischner

Felix G. Fleischner (1893–1969) was an Austrian-American radiologist known for the Fleischner lines and sign, who fled Nazi Austria in 1938 and led radiology at Beth Israel Hospital in Boston.

Felix Haurowitz

Felix Haurowitz was a Czech-born biochemist and immunochemist, born in Prague in 1896, known for the template theory of antibody formation and pioneering work on hemoglobin.

Felix Jacob Marchand

Felix Jacob Marchand (1846–1928) was a German pathologist and professor of pathological anatomy in Leipzig, remembered for coining "atherosclerosis" in 1904 and showing that choriocarcinoma arises from fetal tissue.

Felix Milgrom

Felix Milgrom (1919–2007) was a Polish-born immunologist who chaired Microbiology and Immunology at the University at Buffalo from 1967 to 1985, known for anti-antibodies, rheumatoid factor, and transplant rejection research.

Félix Ratjen

Felix Ratjen is a German-trained Canadian pediatric respirologist at The Hospital for Sick Children in Toronto, known for clinical trials of CFTR modulator drugs in children with cystic fibrosis.

Felix Wieland

Felix T. Wieland, born 1948, is a German biochemist and founding director of Heidelberg University's Biochemistry Center, known for work on COPI-coated vesicles and bulk-flow transport.

Felix Y. Feng

Felix Y. Feng (1975–2024) was an American radiation oncologist and prostate cancer researcher who was a professor at UCSF and developed the first clinical-grade biomarker panels predicting hormone- and radiation-therapy response.

Felix Zijlstra

Felix Zijlstra is a Dutch interventional cardiologist, head of cardiology at Erasmus MC in Rotterdam, known for the Zwolle trials and for chairing the TAPAS thrombus-aspiration trial.

Fellatio

Fellatio, oral stimulation of the penis, is one of three types of oral sex with cunnilingus and anilingus. Practiced by over 85% of US adults 18-44; transmits STIs including gonorrhea, syphilis, HPV, and herpes, with low HIV risk.

Fellowship (medicine)

Fellowship (medicine): post-residency subspecialty training in graduate medical education, also called advanced GME. ACGME-accredited, typically 1-3 years, entered via the NRMP fellowship match, leading to ABMS subspecialty certification.

Felton Earls

Felton Earls (1942–2026) was an American child psychiatrist and epidemiologist at Harvard who showed that collective efficacy, neighbors' shared trust and willingness to act, predicts lower neighborhood violence.

Felty's syndrome

Felty's syndrome (Chauffard-Still-Felty syndrome): rare triad of seropositive rheumatoid arthritis, splenomegaly, and neutropenia (ANC under 1500/mm3), described by Augustus Roi Felty in 1924, overlapping with T-LGL leukemia.

Oct 20, 2026

Felzartamab

Felzartamab (MOR202, TJ202) is a fully human anti-CD38 IgG1 monoclonal antibody by Biogen that depletes plasma cells and NK cells; in phase 2 trials it resolved antibody-mediated kidney-transplant rejection and reduced proteinuria in membranous nephropathy and IgA nephropathy.

Female

Female: one of two biological sex classifications, defined by egg-producing reproductive organs (ovaries, uterus, fallopian tubes, cervix), typically XX chromosomes; covers menstrual cycle, fertility, menopause, and sex in research.

Female adnexal tumor of probable Wolffian origin

FATWO, female adnexal tumor of probable Wolffian origin, is a rare low-malignant-potential gynecologic neoplasm from mesonephric duct remnants, usually in the broad ligament, median age 50, treated by surgical resection.

Female athlete triad

Female athlete triad: syndrome in active girls and women linking low energy availability, menstrual dysfunction, and low bone mineral density; coined by ACSM in 1992, redefined as a spectrum in 2007, related to but distinct from the IOC's broader RED-S term.

Female body shape

Female body shape is the distribution of bone, muscle, and fat on the female body, typically measured by waist-to-hip ratio, which is lower in premenopausal women.

Female condom

Female condom (internal condom): a sheath with two rings worn inside the vagina or anus for dual protection against pregnancy and STIs. FC1 (polyurethane, 1993) and FC2 (nitrile, 2009); 95% effective with correct use, 79% typical use.

Female Contraceptive Devices

Female contraceptive devices prevent pregnancy and include IUDs (copper, levonorgestrel), vaginal barriers (diaphragm, cervical cap, sponge, female condom), and the hormonal vaginal ring, with typical use failure rates from 0.1% to 22%.

Female dyspareunia

Female dyspareunia (ICD-11 GA12) is recurrent genital pain with intercourse or vaginal penetration from an identifiable physical cause; DSM-5 folds it into GPPPD. Prevalence 7.5% (Britain), 10-20% (US).

Female ejaculation

Female ejaculation: urethral fluid expulsion during female orgasm, distinguished since 2011 from squirting; FE is a few mL of PSA-rich milky fluid from Skene's glands, squirting a larger urine-like bladder expulsion, both distinct from coital incontinence.