The short version of prothymosin alpha fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-23 and is reviewed periodically as new material appears.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈3,108 Da | Synthetic 28-residue peptide |
| Amino acid count | 28 | N-terminal serine carries an acetyl group |
| Appearance | White to off-white powder | Lyophilized solid |
| Water solubility | Freely soluble | Dissolves in aqueous buffer |
| Common synonyms | Thymalfasin; Tα1 | Thymalfasin is the international nonproprietary name |
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
== Activists == Samuel Cutler Ward (1831), lobbyist known as the "King of the Lobby" Henry Bergh* (1834), founder of the American Society for the Prevention of Cruelty to Animals and the Massachusetts Society for the Prevention of Cruelty to Children Arthur B. Spingarn (1897), civil rights activist; elected president of the National Association for the Advancement of Colored People 1940–1965; namesake of the Moorland–Spingarn Research Center at Howard University George Marshall (1926), political activist and conservationist John B. Trevor Jr. (1931), director and treasurer of the Pioneer Fund David Crook (1935), British-born Communist ideologue, activist, spy, husband of Isabel Crook, professor at Beijing Foreign Studies University Robert Gnaizda (1957), lawyer, activist, and co-founder of advocacy group Greenlining Institute Morris J.
Labcorp ($14.00B revenue in 2020) IQVIA ($11.35B revenue in 2020) PPD, Inc. ($4.68B revenue in 2020) Syneos Health ($4.41B revenue in 2020) Charles River Laboratories ($2.92B revenue in 2020) ICON PLC ($2.79B revenue in 2020) Parexel ($2.44B revenue in 2017) Wuxi Apptec ($1.01B revenue in 2017) Medpace ($0.92B revenue in 2020)
Combinatorial chemistry involves simultaneously synthesizing a large number of related compounds for high-throughput analysis. Chemical biologists are able to use principles from combinatorial chemistry in synthesizing active drug compounds and maximizing screening efficiency. Similarly, these principles can be used in areas of agriculture and food research, specifically in the syntheses of unnatural products and in generating novel enzyme inhibitors.
Ever since the first discovery of Tyrannosaurus most scientists have agreed that it was an active predator, though like modern large predators it would readily scavenge or steal another predator's kill if it had the opportunity. Paleontologist Jack Horner has been a major proponent of the view that Tyrannosaurus was not a predator at all but instead was an obligate scavenger. He has put forward arguments in the popular literature to support the pure scavenger hypothesis:
=== Clotting phase === Healing of a wound begins with clot formation to stop bleeding and to reduce infection by bacteria, viruses and fungi. Clotting is followed by neutrophil invasion three to 24 hours after the wound has been incurred, with mitoses beginning in epithelial cells after 24 to 48 hours.
Sources: en.wikipedia.org
In the field of atomic, molecular, and optical physics, a branching fraction refers to the probability of decay to a specific lower-lying energy states from some excited state. Suppose we drive a transition in an atomic system to an excited state |e⟩, which can decay into either the ground state |g⟩ or a long-lived state |d⟩. If the probability to decay (the branching fraction) into the |g⟩ state is
Unsupervised learning analyses a stream of data, finds patterns, and makes predictions without any other guidance. Supervised learning requires labelling the training data with the expected answers, and comes in two main varieties: classification (where the program must learn to predict what category the input belongs in) and regression (where the program must deduce a numeric function based on numeric input). Reinforcement learning is when the agent is rewarded for good responses and punished for bad ones. The agent learns to choose responses that are classified as "good". Transfer learning is when the knowledge gained from one problem is applied to a new problem. Deep learning is a type of machine learning that runs inputs through biologically inspired artificial neural networks for all of these types of learning. Computational learning theory can assess learners by computational complexity, sample complexity (how much data is required), or other notions of optimisation.
(2026) reconstruct the diet of Miocene rodents and South American native ungulates from the La Venta site (Colombia) on the basis of stable isotope analyses of tooth enamel, reporting evidence of C3-dominated diets of the studied mammals, but also evidence of ecological differentiation. Casanovas-Vilar et al. (2026) interpret the small mammal assemblage from the Vallès-Penedès Basin (Spain) as consistent with a climate during the Miocene that was transitional between humid subtropical and Mediterranean types, finding no evidence of significant climate changes at the times of major faunal turnovers. Martín-Perea et al. (2026) study the taphonomy of late Miocene mammalian assemblages from the Daidian and Dongmen sites (China), and interpret the studied assemblages as resulting from gradual accumulation through attritional mortality. Evidence from fossil data from low latitudes in Mexico, indicating that the dispersal of North American mammals into South America during the Great American Interchange was preceded and primed by their accumulation in Mexico beginning 10 million years ago, is presented by Tseng et al. (2026).
Investigations concerning Kupffer cells are hampered because in humans, Kupffer cells are only accessible for immunohistochemical analysis from biopsies or autopsies. From rats and mice, they are difficult to isolate, and after purification, only approximately 5 million cells can be obtained from one mouse. Macrophages can express paracrine functions within organs that are specific to the function of that organ. In the testis, for example, macrophages have been shown to be able to interact with Leydig cells by secreting 25-hydroxycholesterol, an oxysterol that can be converted to testosterone by neighbouring Leydig cells. Also, testicular macrophages may participate in creating an immune privileged environment in the testis, and in mediating infertility during inflammation of the testis. Cardiac resident macrophages participate in electrical conduction via gap junction communication with cardiac myocytes. Macrophages can be classified on basis of the fundamental function and activation. According to this grouping, there are classically activated (M1) macrophages, wound-healing macrophages (also known as alternatively-activated (M2) macrophages), and regulatory macrophages (Mregs).
Sources: en.wikipedia.org
Westbrook* (1968), writer, son of syndicated columnist Sheilah Graham Westbrook Phillip Lopate (1964), essayist and fiction writer Ron Padgett (1964), poet and translator, winner of the Shelley Memorial Award in 2009 and Robert Frost Medal in 2018 Steven Millhauser (1965), novelist and winner of the Pulitzer Prize for Fiction for Martin Dressler: The Tale of an American Dreamer Aaron Fogel (1967), poet Eric Van Lustbader (1967), espionage and thriller novelist, writer of Jason Bourne novels Thomas Hauser (1968), author of nonfiction and biographer David Shapiro (1968), poet, literary critic, professor at William Paterson University Hilton Obenzinger (1969), novelist, poet, history and criticism writer Paul Auster (1970), postmodern writer; author of The New York Trilogy, Moon Palace, and the Brooklyn Follies Bob Holman (1970), poet and activist identified with the oral tradition David Lehman (1970), poet, editor of The Best American Poetry series Joshua Rubenstein (1971), writer, winner of a National Jewish Book Award in 2002 Alex Abella (1972), Cuban-American writer Brad Gooch (1973), writer, professor of English at William Paterson University John Prados (1973), author and historian on World War II and the Cold War Todd McEwen (1975), writer, professor at the University of Kent Stephen O'Connor (1975), writer and professor at Sarah Lawrence College Damien Bona (1977), chronicler of the Academy Awards Mason Wiley (1977), co-author of The Official Preppy Handbook Kevin Baker (1980), novelist and freelance journalist Jeffrey Harrison (1980), poet who won the 1988 Amy Lowell Poetry Travelling Scholarship Lou Antonelli (1981), science fiction writer Douglas Sadownick (1981), writer and psychologist Michael Friedman (1982), novelist and author Michael Azerrad (1983), author, journalist, musician Thomas Dyja (1984), writer, historian, winner of the 1997 Casey Award David Rakoff (1986), comedic essayist Louise Wareham Leonard (1987), writer Al Weisel (1987), freelance writer Adrienne Brodeur (1988), author, program director at Aspen Institute Glen Hirshberg (1988), author, recipient of the 2007 Shirley Jackson Award Adam Mansbach (1988), author and former professor of literature at Rutgers University–Camden Darryl Pinckney (1988), novelist, playwright, and essayist Mako Yoshikawa (1988), novelist, professor at Emerson College Ben Coes (1989), author of political thriller and espionage novels Wade Graham (1989), author, historian, environmentalist G. Winston James (1989), poet, author, activist Robert Salkowitz (1989), author on technology innovation Carol Guess (1990), novelist and poet; professor at Western Washington University John Reed (1990), novelist; author of Snowball's Chance David S. Levinson (1991), short-story writer and novelist Robert Kolker (1991), writer, author of Hidden Valley Road Kelly Link (1991), Hugo Award-winning author; founder of Small Beer Press; editor of St. Martin's Press's Year's Best Fantasy and Horror Loren Goodman (1991), postmodern poet, professor at Underwood International College Andrew Carroll (1992), author, editor, activist, and historian Jordan Davis (1992), poet John Bemelmans Marciano (1992), children's book author and illustrator, grandson of Ludwig Bemelmans, author of Madeline Marie Mutsuki Mockett (1992), writer Melissa de la Cruz (1993), writer known for work in young adult fiction Jay Michaelson (1993), writer and LGBTQ activist Maxine Swann (1994), fiction writer Robert Westfield (1994), writer who won two Lambda Literary Awards Megan McCafferty (1995), chick lit writer, Jessica Darling series, which were plagiarized by Kaavya Viswanathan Tova Mirvis (1995), author Saleemah Abdul-Ghafur (1996), author and Islamic activist Fredrik Stanton (1996), author of Great Negotiations and former publisher for the Columbia Daily Spectator Aravind Adiga (1997), Man Booker Prize-winning novelist Jamel Brinkley (1997), author, winner of the 2018 Ernest J. Gaines Award for Literary Excellence John Coletti (1997), author Gotham Chopra (1997), author, son of health advocate Deepak Chopra Lauren Grodstein (1997), author, professor of Rutgers University–Camden Abdi Nazemian (1998), Iranian-American author, winner of the 2017 Lambda Literary Award for Debut Fiction Trevor Shane (1998), writer Daniel Alarcón (1999), novelist Katherine Howe (1999), novelist, author of The Physick Book of Deliverance Dane Rebecca Pawel (1999), author of mystery novels; winner of the 2004 Edgar Allan Poe Award for Best First Novel Alex Marzano-Lesnevich (2001), author, winner of a 2018 Lambda Literary Award and Chautauqua Prize Fiona Sze-Lorrain (2003), French writer, poet, translator, musician Ben Dolnick (2004), writer, son of biographer Edward Dolnick, member of the Ochs-Sulzberger family that owns The New York Times Danielle Valore Evans (2004), fiction writer Adam Gidwitz (2004), author of best selling children's books Alaya Dawn Johnson (2004), author and winner of the 2015 Andre Norton Award Tongo Eisen-Martin (2004), poet laureate of San Francisco Sidik Fofana (2005), public school teacher and writer, winner of a 2023 Whiting Award Victoria Loustalot (2006), writer of memoir and essays Crystal Hana Kim (2009), writer, If You Leave Me Morgan Parker (2010), poet and Cave Canem Fellow Rachel Heng (2011), Singaporean writer Ben Philippe (2011), author, screenwriter, recipient of the 2020 William C. Morris Award Rowan Hisayo Buchanan (2012), British-American writer, recipient of the Betty Trask Award and the Authors' Club Best First Novel Award Sylvia Khoury (2012), writer and playwright, recipient of a 2021 Whiting Award Yanyi (2013), poet
Establishing SIUT, Sukkur, was an innovative response to the need of the people of Sindh was planned in the year 2009. Rizvi anticipates the needs of his patients and responds accordingly. To make dialysis accessible, he conceptualized a network of satellite centers in various parts of Pakistan to save patients the trouble of commuting from far-flung areas of Sindh, southern parts of Punjab and Baluchistan to go for this procedure twice a week as far as Karachi. On 2 February 2012 Adibul Hasan Rizvi, Director Sindh Institute of Urology and Transplantation, along with a team of doctors and paramedical staff inaugurated SIUT-Chablani Medical Center Sukkur. Initially as a day care Dialysis Center with 16 Haemodialysis machines and OPD, which shall facilitate a large number of underprivileged patients of Upper Sindh, Lower Punjab & Baluchistan.
=== 3. Radical Retrosynthesis === Radical retrosynthesis adds to the toolbox of synthetic planning by additionally considering intuitive radical disconnections and cross-coupling molecular partners. As methods develop towards more 1e- thinking, this strategic and tactical approach to synthesis will continue to aid in the construction of interesting and valuable natural products and medicinally important compounds. Radical retrosynthesis maximizes convergency by making disconnections that are not wedded to traditional polar bond analysis. The most useful methods from a tactical standpoint in this regard use radical cross coupling.
Sources: en.wikipedia.org
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.
It is usually described as an immunomodulatory peptide rather than a classic hormone. It acts on immune cells through receptor pathways. No single endocrine organ target defines its function.
Several countries, including Italy and China, allow it for specific indications. The FDA has not approved it as a drug in the United States. Availability depends on local regulation.
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.