All articles starting with F
15,892 articles
Fibration
A fibration is a continuous map between topological spaces with the homotopy lifting property; Serre fibrations, introduced in 1951, organize homotopy theory and yield long exact sequences of homotopy groups.
Fibre Channel
Fibre Channel (FC) is a high-speed network technology designed primarily for storage area networks, in which servers and storage systems exchange block data over a dedicated switched fabric.
Fibre-reinforced plastic
Fibre-reinforced plastic (FRP), also called fiber-reinforced polymer, is a composite material in which strong fibers such as glass or carbon are embedded in a polymer matrix for lightweight strength.
Fibril
Fibril (Fib), Spiroplasma fibril protein, a 59-kDa cytoskeletal protein unique to the helical wall-less bacterium Spiroplasma; forms a seven-fibril ribbon under the membrane that sets helical cell shape and drives helicity-switching swimming.
Fibrin
Fibrin, the insoluble fibrous protein formed from fibrinogen by thrombin cleavage, builds the blood clot mesh, is stabilized by factor XIIIa, dissolved by plasmin in fibrinolysis, and used clinically as fibrin sealants and tissue-engineering scaffolds.
Fibrin formation
Fibrin formation: thrombin cleaves fibrinogen, releasing fibrinopeptides A and B, into fibrin monomers that polymerize via knob-hole interactions into protofibrils, fibers, and a 3D clot network cross-linked by factor XIIIa.
Fibrin sealant
Fibrin sealant is a two-component surgical agent of fibrinogen and thrombin that mimics the final stage of blood clotting, acting as a hemostat, sealant, and tissue adhesive.
Fibrinogen
Fibrinogen (coagulation factor I) is a 340-kDa plasma glycoprotein that thrombin converts to fibrin for blood clotting; also an acute-phase protein and studied cardiovascular risk marker, with concentrate therapies for congenital deficiency.
Fibrinogen i 125
Fibrinogen i 125 (^{125}I-fibrinogen) is iodine-125-labeled fibrinogen used from 1965 in the fibrinogen uptake test to detect deep vein thrombosis; accurate for calf clots but limited in the thigh and later superseded.
Fibrinogen silencer-binding protein
Fibrinogen silencer-binding protein (FSBP, O95073) is a human 299-aa nuclear transcriptional repressor that down-regulates the fibrinogen gamma chain and represses the GSK3B promoter via APBA1; gene FSBP at 8q22.1.
Fibrinolysis
Fibrinolysis, also called clot lysis or fibrin breakdown, is the plasmin-mediated degradation of fibrin blood clots, regulated by tPA, uPA, PAI-1, alpha2-antiplasmin, and TAFI, and targeted by thrombolytic and antifibrinolytic drugs such as tranexamic acid.
Fibrinolytic therapy
Fibrinolytic therapy is drug treatment that dissolves blood clots by converting plasminogen to plasmin, used in heart attack, stroke, and pulmonary embolism, with bleeding as its main risk.
Fibrinopeptide A
Fibrinopeptide A is a 16-residue peptide cleaved from fibrinogen by thrombin during blood coagulation, exposing polymerization sites for clot formation and serving as a clinical marker of thrombin activity.
Fibro-adipose vascular anomaly
Fibro-adipose vascular anomaly (FAVA), a rare ISSVA-provisionally unclassified vascular malformation first described in 2014, causes painful fibrofatty intramuscular lesions with contractures, PIK3CA mutations, and frequent misdiagnosis as venous malformation.
Fibroadenoma
Fibroadenoma, the commonest benign breast tumor, a biphasic epithelial-stromal lesion of reproductive-age women; diagnosed by triple assessment, usually observed, excised if large, growing, or discordant.
Fibroadenosis of breast
Fibroadenosis of breast, also called fibrocystic breast changes or fibrocystic breast disease, is a common benign condition with lumpy breast tissue from fibrosis, cysts, and adenosis; it does not raise breast cancer risk.
Fibrobacter
Fibrobacter, genus Fibrobacterota, gram-negative anaerobic cellulolytic bacteria of mammalian guts; two species, F. succinogenes (rumen) and F. intestinalis; named Montgomery et al. 1988; noncellulosomal cellulase system.
Fibroblast
Fibroblast: connective tissue cell secreting collagen-rich extracellular matrix; also called fibrocytes when quiescent. Term coined by Ziegler 1895; differentiates into contractile myofibroblasts during wound healing; profoundly heterogeneous across organs.
Fibroblast growth factor
Fibroblast growth factors (FGFs), also called heparin-binding growth factors, are a 22-gene family of signaling proteins acting through FGFR tyrosine kinase receptors with heparan sulfate or Klotho cofactors, governing development, wound repair, metabolism, and cancer.
Fibroblast growth factor receptor
Fibroblast growth factor receptors (FGFR1-4) are transmembrane receptor tyrosine kinases for FGF ligands, altered in 5-10% of cancers; targeted by approved inhibitors erdafitinib, pemigatinib, and futibatinib, limited by gatekeeper-mutation resistance and hyperphosphatemia.
Fibroblast growth factor receptor 1
Fibroblast growth factor receptor 1 (FGFR1, CD331, BFGFR) is an 822-amino-acid human receptor tyrosine kinase on chromosome 8 that binds FGFs via IgII-III domains; variants cause Kallmann and Pfeiffer syndromes, and fusions drive 8p11 myeloproliferative syndrome.
Fibroblast growth factor receptor 2
Fibroblast growth factor receptor 2, or FGFR2, is a receptor tyrosine kinase on chromosome 10 that signals for bone and tissue development; activating mutations cause craniosynostosis syndromes and FGFR2 fusions are drug targets in cholangiocarcinoma.
Fibroblast growth factor receptor 3
FGFR3 (fibroblast growth factor receptor 3) is a chromosome 4 receptor tyrosine kinase that limits cartilage-to-bone growth; gain-of-function mutations cause achondroplasia and related skeletal dysplasias, loss-of-function CATSHL, and somatic mutations recur in bladder cancer.
Fibroblastic disorders
Fibroblastic disorders (ICD-11 FB51) are soft-tissue conditions driven by fibroblast or myofibroblast proliferation, including palmar and plantar fibromatosis (Dupuytren, Ledderhose), knuckle pads, fibroblastic rheumatism, and retroperitoneal fibrosis.
Fibroblastic reticular cell tumour
Fibroblastic reticular cell tumour (FRCT), also called cytokeratin-positive interstitial reticulum cell tumor, is a rare malignant stromal neoplasm of lymphoid tissue (ICD-O 9759/3, ICD-11 2B31.7) affecting lymph nodes, spleen, and soft tissue, positive for cytokeratin, SMA, desmin, and CD68.
Fibroblastic rheumatism
Fibroblastic rheumatism (le rhumatisme fibroblastique), ORPHA:477650, is a rare rheumatologic disease first described in 1980, combining sudden symmetric distal polyarthritis with firm skin nodules, sclerodactyly, and fibroblastic dermal proliferation; about 30 cases reported worldwide.
Fibrochondrogenesis
Fibrochondrogenesis (ORPHA:2021, OMIM 228520/614524) is a rare, mostly neonatally lethal short-limb skeletal dysplasia from COL11A1 or COL11A2 mutations affecting type XI collagen, with flat midface, dumbbell long bones, and pinched vertebral bodies.
Fibrodysplasia ossificans progressiva
Fibrodysplasia ossificans progressiva (FOP, myositis ossificans progressiva, stone man disease) is an ultra-rare ACVR1 genetic disorder in which muscle, tendons, and ligaments progressively turn to bone, marked by congenital malformed big toes, flare-ups, and treatments palovarotene, garetosmab, and zilurgisertib.
Fibrolamellar hepatocellular carcinoma
Fibrolamellar hepatocellular carcinoma (FLC, FL-HCC) is a rare liver cancer of adolescents and young adults with healthy livers, defined by the DNAJB1::PRKACA fusion from a chromosome 19 deletion; surgery is the only curative treatment.
Fibroma
Fibroma: a benign tumor of fibrous connective tissue, also called fibrous tumor; includes plantar, non-ossifying, oral, ovarian, and skin types; malignant counterpart is fibrosarcoma.