thymus extract is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
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 |
|---|---|---|
| Chemical class | Synthetic peptide, 28 residues | N-terminal fragment of prothymosin alpha |
| Molecular mass | About 3108 Da | Acetylated form |
| Isoelectric point | Near 4.2 | Acidic peptide |
| Appearance | White to off-white lyophilized powder | Common supplied form |
| Typical storage | -20 °C or below, dry | Solution stability is lower |
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
Lyophilized material is typically treated as a hygroscopic solid that should be brought to room temperature before the container is opened, which limits condensation on the powder. Reconstitution is commonly done with sterile water or a buffered diluent, and gentle mixing is preferred over vigorous agitation to reduce foaming and surface adsorption. Because peptides can bind to plastic and glass, diluents containing a small amount of carrier protein are sometimes used in laboratory work. Working solutions are generally aliquoted and prepared fresh rather than subjected to repeated freezing and thawing.
== Paleobiology == Knowledge about dinosaurs is derived from a variety of fossil and non-fossil records, including fossilized bones, feces, trackways, gastroliths, feathers, impressions of skin, internal organs and other soft tissues. Many fields of study contribute to our understanding of dinosaurs, including physics (especially biomechanics), chemistry, biology, and the Earth sciences (of which paleontology is a sub-discipline). Two topics of particular interest and study have been dinosaur size and behavior.
SIMS and FAB are quite similar. SIMS uses an ion beam, usually Ar+ or Cs+. FAB uses a neutral atom beam, usually Ar or Xe. For SIMS and FAB, if the matrix compound is more acidic than the analyte, then predominantly (M + H)+ forms formed, and conversely (M − H)−. Also possibly forming (M + Na)+, (M + K)+, etc, if the matrix is contaminated incidentally (adventitiously) by sodium, potassium, etc. Typical matrix materials include glycerol, thioglycerol, 3-nitrobenzyl alcohol, diethanolamine, triethanolamine, and dithiothreitol-dithioerythritol mixture. They are usually used to analyze polypeptides and oligonucleotides up to 20 kDa. MALDE uses a photon beam, usually the soft-UV 337 nm nitrogen laser. It can also use an infrared (IR) laser for direct analysis of samples contained in gels or thin-layer chromatography (TLC) plates. MALDE can analyze small polymers (~1 kDa), to oligosaccharides, oligonucleotides and polypeptides, antibodies, up to small proteins (~300 kDa). It is highly sensitive, requiring only femtomoles of sample. Desorption/ionization on silicon (DIOS) is similar to MALDE, but without the matrix. The sample is deposited directly on a nanostructured (porous silicon) surface and the sample desorbed directly from the nanostructured surface through the adsorption of laser light energy. DIOS has been used to analyze organic molecules, metabolites, biomolecules and peptides, and, ultimately, to image tissues and cells.
Druze, like some Christians, believe that Elijah came back as John the Baptist, or as Saint George, since they belief in reincarnation and the transmigration of the soul, Druze believe that El Khidr and John the Baptist are one and the same. Saint George is described as a prophetic figure in Druze sources; and in some sources he is identified with Elijah or Mar Elias, and in others as al-Khidr. Druze believe that Elijah came back as John the Baptist and as Saint George, and the Druze version of the story of al-khidr was syncretized with the story of Saint George and the Dragon. The shrine of al-Khidr is located in the village of Kafr Yasif near the city of Acre on the Mediterranean coast. It is considered one of the most famous shrines in Druze religion. The prophet's name is "Sidna Abu Ibrahim" and he is nicknamed Nabi Al-Khidr (the Green One). Al-Khidr is identified with Elijah the prophet and, according to Druze belief, is one of the founders of their religion. The nickname El-Khidr (the Green One) comes from the belief that his memory will always be fresh like a green plant. Ziyarat al-Nabi al-Khidr is an Israeli Druze festival called Ziyara celebrated on 25 January which is officially recognized in Israel as a public holiday for Druzes, the celebration starts on 24 January and concludes on 25 January, with many religious leaders from all the religions in Israel, and also political leaders (occasionally also the PM), coming to congratulate the Israeli Druze community during their festivities at the Maqam Al-Khidr in Kafr Yasif.
=== Emergency approvals (EUA) === Emergency Use Authorization (EUA) is a mechanism that was created to facilitate the availability and use of medical countermeasures, including vaccines and personal protective equipment, during public health emergencies such as the Zika virus epidemic, the Ebola virus epidemic and the COVID-19 pandemic.
Site-specific recombination makes use of phage integrases instead of restriction enzymes, eliminating the need for having restriction sites in the DNA fragments. Instead, integrases make use of unique attachment (att) sites, and catalyse DNA rearrangement between the target fragment and the destination vector. The Invitrogen Gateway cloning system was invented in the late 1990s and uses two proprietary enzyme mixtures, BP clonase and LR clonase. The BP clonase mix catalyses the recombination between attB and attP sites, generating hybrid attL and attR sites, while the LR clonase mix catalyse the recombination of attL and attR sites to give attB and attP sites. As each enzyme mix recognises only specific att sites, recombination is highly specific and the fragments can be assembled in the desired sequence. Vector design and assembly Because Gateway cloning is a proprietary technology, all Gateway reactions must be carried out with the Gateway kit that is provided by the manufacturer. The reaction can be summarised into two steps. The first step involves assembling the entry clones containing the DNA fragment of interest, while the second step involves inserting this fragment of interest into the destination clone.
Sources: en.wikipedia.org
==== Magnetoreception and infrared sensing ==== Like birds, microbats' sensitivity to the Earth's magnetic field gives them great magnetoreception. Microbats use a polarity-based compass, which means they can distinguish north from south, unlike birds, which use the strength of the magnetic field to differentiate latitudes, which may be used in long-distance travel. The mechanism possibly involves magnetite particles. Vampire bats are the only mammals that use infrared sensing; heat sensors around the nose allow them to detect blood vessels near the surface of the skin of their target.
John's wort), seseli, thlaspi, Daucus carota (carrot), Piper nigrum (black pepper), Piper longum (long pepper), Juniperus (juniper), Syzygium aromaticum (clove), Canary Island wine, Agaricus fruiting bodies Gums, oils and resins: Acaciae (acacia), Styrax benzoin, Gummi arabicum, Sagapeni (wax of an unknown tree, possibly some kind of Ferula), Gummi Opopanax chironium, Gummi Ferula foetida, Commiphora (myrrh), incense, Turpentine from Cyprus, oil from Myristica fragans (nutmeg), Papaver somniverum latex (opium). Animal parts and products: Castoreum, Trochisci Viperarum, Narbonne white honey Mineral substances: Boli armen. verae, Chalciditis (copper salts), Dead Sea bitumen
The HBED structure acts as the chelator, in which a radiometal is coordinated. A linker structure which conjugates the other two molecular components, in this radiopharmaceutical it is a lysine moiety. A binding motif or pharmacophore such as a peptide or antibody, which will bind to the target. One of the most popular HBED chelators is HBED-CC. This chelator can create stable complexes with trivalent gallium at normal temperatures and it attaches to bioactive molecules through its propionic acid moieties.
Folgers is promoted with the slogan "The best part of waking up is Folgers in your cup!" It is well associated with a jingle featured in almost every advertisement since 1984, with lyrics by Susan Spiegel Solovay and Bill Vernick, and music by Leslie Pearl. Over the years it has been rearranged and performed by many famous musicians, such as Richie Havens, Randy Travis, Bonnie Tyler, Paul Stanley, Aretha Franklin, and Rockapella. From 1965 to 1986, Folgers was known for television ads involving "Mrs. Olson", a Swedish neighbor played by Virginia Christine who invariably recommended a cup of Folgers coffee for the characters in the commercial. Folgers promoted their instant coffee in the 1970s and early 1980s ads which took the viewer inside various 'high-end' restaurants while a voice-over (by Bryan Clark) whispered to the viewer that they've secretly switched the coffee used at the restaurant with Folgers, and watched the restaurants' patrons to see if they could tell whether or not they noticed the difference. One Folgers television ad from 1985, "Peter Comes Home For Christmas," became particularly associated with the Christmas holidays. A college student returns home, apparently on Christmas Day. His younger sister is the first one to greet Peter, helping him make the Folgers. The smell of freshly brewed coffee awakening his parents and alerting them to their son's arrival. The Cunningham & Walsh spot aired yearly until 1998, then in edited form in 2004 and 2005. In the mid-1980s Folgers became a NASCAR sponsor.
Sources: en.wikipedia.org
Reef-building corals are well-studied holobionts that include the coral itself together with its symbiont zooxanthellae (photosynthetic dinoflagellates), as well as its associated bacteria and viruses. Co-evolutionary patterns exist for coral microbial communities and coral phylogeny. It is known that the coral's microbiome and symbiont influence host health, however, the historic influence of each member on others is not well understood. Scleractinian corals have been diversifying for longer than many other symbiotic systems, and their microbiomes are known to be partially species-specific. It has been suggested that Endozoicomonas, a commonly highly abundant bacterium in corals, has exhibited codiversification with its host. This hints at an intricate set of relationships between the members of the coral holobiont that have been developing as evolution of these members occurs. A study published in 2018 revealed evidence of phylosymbiosis between corals and their tissue and skeleton microbiomes. The coral skeleton, which represents the most diverse of the three coral microbiomes, showed the strongest evidence of phylosymbiosis. Coral microbiome composition and richness were found to reflect coral phylogeny. For example, interactions between bacterial and eukaryotic coral phylogeny influence the abundance of Endozoicomonas, a highly abundant bacterium in the coral holobiont. However, host-microbial cophylogeny appears to influence only a subset of coral-associated bacteria.
Rarely is Huntington's disease caused by a new mutation, where neither parent has over 36 CAG repeats. In the rare situations where both parents have an expanded HD gene, the risk increases to 75%, and when either parent has two expanded copies, the risk is 100%. Individuals with both genes affected are rare. For some time, HD was thought to be the only disease for which possession of a second mutated gene did not affect symptoms and progression, but it has since been found that it can affect the phenotype and the rate of progression.
=== The twelve nidanas === The popular listing of twelve nidānas is found in numerous sources. In some of the early texts, the nidānas themselves are defined and subjected to analysis (vibhaṅga). The explanations of the nidānas can be found in the Pali SN 12.2 (Vibhaṅga "Analysis" sutta) and in its parallel at SA 298. Further parallels to SN 12.2 can be found at EA 49.5, some Sanskrit parallels such as the Pratītyasamutpādādivibhaṅganirdeśanāmasūtra (The Discourse giving the Explanation and Analysis of Conditional Origination from the Beginning) and a Tibetan translation of this Sanskrit text at Toh 211.
In October 2012, following its legal victory over Joe Shuster's estate for the rights to Superman, Warner Bros. Pictures announced that it planned to move ahead with its long-awaited Justice League film, uniting such DC Comics superheroes as Batman, Superman, and Wonder Woman. The company was expected to take the opposite approach to Marvel, releasing individual films for the characters after they have appeared in a team-up film. The release of Man of Steel in 2013 was intended to be the start of a new shared universe for DC, "laying the groundwork for the future slate of films based on DC Comics". In 2014, Warner Bros. announced that slate of films, similarly to Disney and Marvel claiming dates for films years in advance. That year, DC chief creative officer Geoff Johns stated that the television series Arrow and The Flash were set in a separate universe from the new film one, later clarifying that "We look at it as the multiverse. We have our TV universe and our film universe, but they all co-exist. For us, creatively, it's about allowing everyone to make the best possible product, to tell the best story, to do the best world. Everyone has a vision and you really want to let the visions shine through ... It's just a different approach [from Marvel's]." Discussing the apparent failure of the cinematic universe's first team-up film, Batman v Superman: Dawn of Justice (2016), to establish a successful equivalent to the MCU, Emily St.
==== Oceania ==== In 1967, the first 99mTc procedures were carried out in Auckland, New Zealand. 99Mo was initially supplied by Amersham, UK, then by the Australian Nuclear Science and Technology Organisation (ANSTO) in Lucas Heights, Australia.
Sources: en.wikipedia.org
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.
Thymosin alpha-1 is a single defined 28-residue peptide, while the broader family includes unrelated peptides such as thymosin beta-4. The shared name reflects historical isolation from thymus tissue rather than a common structure. Confusion between the two is common in older literature.
No single pathway fully accounts for its reported effects. Several studies describe interaction with innate immune receptors and downstream cytokine changes, but the complete picture is not settled. Open questions remain about which effects occur at physiological concentrations.
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.