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 2026-03-21 and is reviewed periodically as new material appears.
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.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
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.
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.
The lyophilized peptide is a white to off-white powder that dissolves freely in water and in aqueous buffers near neutral pH. Because the molecule carries a net negative charge under physiological conditions, saline and phosphate solutions are the usual vehicles, while strongly acidic media are avoided. Stock solutions are commonly divided into small aliquots so that repeated freezing and thawing can be limited, since cycling may encourage aggregation. Solubility in organic solvents is poor and those solvents are seldom used as primary diluents.
Recommended storage for the dry powder is a freezer near minus twenty degrees Celsius, kept desiccated and away from light. Once dissolved, the peptide is less stable and is usually held at two to eight degrees Celsius for short intervals or frozen for longer storage. Stability studies focus on the acetylated terminus and the disulfide linkage because those features define the intact molecule. Common degradation routes include cysteine oxidation, deamidation of asparagine or glutamine side chains, and slow formation of higher-molecular-weight species.
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.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
=== Apodization in astronomy === Apodization is used in telescope optics to improve the dynamic range of the image. For example, stars with low intensity in the close vicinity of very bright stars can be made visible using this technique, and even images of planets can be obtained when otherwise obscured by the bright atmosphere of the star they orbit. Generally, apodization reduces the resolution of an optical image; however, because it reduces diffraction edge effects, it can actually enhance certain small details. In fact, the notion of resolution, as it is commonly defined with the Rayleigh criterion, is in this case partially irrelevant. One has to understand that the image formed in the focal plane of a lens (or a mirror) is modeled through the Fresnel diffraction formalism. The classical diffraction pattern, the Airy disk, is connected to a circular pupil, without any obstruction, and with a uniform transmission. Any change in the shape of the pupil (for example a square instead of a circle), or its transmission, results in an alteration to the associated diffraction pattern.
== Efficacy and side effects == Just like cocaine, dimethocaine inhibits the uptake of dopamine in the brain by interfering with the dopamine transporters. The potency of these drugs is linked to their affinity for the dopamine transporters, and their potency to inhibit dopamine uptake. In studies with rhesus monkeys the affinity of dimethocaine for dopamine transporters is smaller than that of cocaine, whereas dimethocaine's potency to inhibit dopamine uptake is similar. This means that more of dimethocaine is needed to reach a similar response. The peak effects occurred within 10 to 20 minutes after the injection and decreased to baseline levels within an hour. Dimethocaine is often abused as a legal substitute for cocaine. The drug is administered intravenously or nasally, because ingestion would lead to rapid hydrolyzation. Its positive effects are euphoria, stimulation, increased talkativeness and mood lift. However, because the drug acts similar as cocaine, it has comparable negative side effects. These side effects include: tachycardia, difficulty with breathing, pain on the chest, vasoconstriction, insomnia, paranoia and anxiety. Dimethocaine probably poses larger health issues than cocaine. This is due to the fact that more dimethocaine must be administered to produce the same euphoric feeling, resulting in larger risk for the negative effects.
2000 – 2008 Member of the board of the Technical University of Denmark. 2000 – 2003 Member of the Academy of Technical Sciences, Denmark 2003 – 2004 President of the Academy of Technical Sciences, Denmark 2006 – 2012 Member of the board of Cellartis AB, Sweden 2012 – 2019 Member of the board of the University of Copenhagen (chairman from 2017 to 2020) 2014 - 2016 Chairman of the board, Steno Diabetes Center, Denmark 2018 - 2019 Board member, Symphogen A/S, Denmark 2020 - Member of the board of BB Biotech AG, Switzerland
After being absorbed in the small intestine, iron travels through blood, bound to transferrin, and eventually ends up in the bone marrow, where it is involved in red blood cell formation. When red blood cells are degraded, the iron is recycled by the body and stored. When the amount of iron needed by the body exceeds the amount of iron that is readily available, the body can use iron stores (ferritin) for a period of time, and red blood cell formation continues normally. However, as these stores continue to be used, iron is eventually depleted to the point that red blood cell formation is abnormal. Ultimately, anemia ensues, which by definition is a hemoglobin lab value below normal limits.
Just Stop Oil protesters vandalise Stonehenge by spraying the megaliths with orange cornflour powder paint. A police officer working as part of the prime minister's close protection team is suspended and later arrested as part of an ongoing investigation into bets on the date of the general election. BBC News reports that Laura Saunders, the Conservative candidate for Bristol North West, has become the second Conservative candidate to face an investigation by the Gambling Commission over betting on the date of the general election. It is subsequently reported that her husband, Tony Lee, the Conservative Party's campaigns director, is also being investigated by the commission. 20 June The Bank of England holds interest rates at 5.25%, its seventh consecutive freeze. Sunak says he is "incredibly angry" to learn of allegations that members of his party have betted on the date of the election, and that he will "boot out" anyone found to have broken the law. The number of people becoming ill from a recent outbreak of E. coli across the UK reaches 256, which includes 86 hospitalisations. The UK Health Security Agency reports that case numbers have now slowed, and that everything possible is being done to find the root cause, which may be pre-packaged sandwiches containing lettuce. 21 June Nigel Farage tells the BBC that he believes the Russo-Ukrainian War to have been precipitated by the West's eastward expansion of NATO and the European Union, but that the war itself is Vladimir Putin's fault.
Sources: en.wikipedia.org
The key intermediate step of these cyclometalation reactions involves the metal-mediated cleavage of the C–H bond and simultaneous formation of the metal–C bond of the substrate. Upon addition of substrate, the N-acyl motif acts as an internal proton acceptor in the concerted metal-deprotonation (CMD) of the transition state for this inner-sphere process. According to this model, the rate and selectivity of the C–H functionalization are impacted by the basicity of the MPAA ligand. The resulting experimental data of steric and electronic alteration of the MPAA ligands align with this model. In 2023, the first experimental observations to support the proposed mechanism were reported, which were previously unattainable due to the lack of well-defined isolated palladium-MPAA complexes.
Michael Francis Compton (b. 25 November 1940) [with Doreen Crick] Gabrielle Anne (b. 15 July 1951) [with Odile Crick] Jacqueline Marie-Therese [later Nichols] (b. 12 March 1954, d. 28 February 2011) [with Odile Crick]; Crick died of colon cancer on the morning of 28 July 2004 at the University of California, San Diego (UCSD) Thornton Hospital in La Jolla; he was cremated and his ashes were scattered into the Pacific Ocean. A public memorial was held on 27 September 2004 at the Salk Institute, La Jolla, near San Diego, California; guest speakers included James Watson, Sydney Brenner, Alex Rich, Seymour Benzer, Aaron Klug, Christof Koch, Pat Churchland, Vilayanur Ramachandran, Tomaso Poggio, Leslie Orgel, Terry Sejnowski, his son Michael Crick, and his younger daughter Jacqueline Nichols. A private memorial for family and colleagues was held on 3 August 2004. Crick's Nobel Prize medal and diploma from the Nobel committee was sold at Heritage Auctions in June 2013 for $2,270,000. It was bought by Jack Wang, the CEO of Chinese medical company Biomobie. 20% of the sale price of the medal was donated to the Francis Crick Institute in London.
Half-Life: Echoes – Having a greater emphasis on survival horror than the base game, the player controls an unnamed scientist at the Black Mesa Research Facility surviving the Resonance Cascade and invasion by Xen and HECU forces. Point of View – A mod released on May 2, 2003 by the developers of Azure Sheep. The player character is a vortigaunt named Xonxt. The player can only use alien weaponry and has no armor. Medkits can't be used, instead Xen healing pools have to be used for restoring health. The Games Machine gave the mod a positive review. PC Zone gave the mod a rating of 76 out of 100 and called it "a refreshing alternative". Poke646 – Released in December 2001. Takes place after the events of Half-Life in Nation City. Features new weapons and textures. Named often one of the best single-player mods for Half-Life. Poke646: Vendetta – Released in December 2006. Sequel to Poke646. Received a positive review by PC Action. They Hunger – This is a single-player horror-based mod. It was released by Neil Manke's Black Widow Games in three episodes, the first in 1999, the second in 2000, and the final installment in 2001. All three were at one point bundled with PC Gamer magazine. USS Darkstar – A mod by Neil Manke, produced by PC Gamer and released on July 14, 1999. This mod follows a scientist on a deep-space scientific mission aboard an interstellar spacecraft. When an experiment goes awry, the player has to defend himself against aliens. The mod was first released on the PC Gamer website and was featured on the magazine's demo CD in August 1999.
Whereas the biological half-life of estradiol given by intravenous injection is about 0.5 to 2 hours, the biological half-life of oral estradiol has a range of 13 to 20 hours due to the large and long-lasting pool of estrogen conjugates that is formed during first-pass metabolism and that serves to continuously replenish circulating estradiol levels.
Sources: en.wikipedia.org
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.
Reverse-phase HPLC with ultraviolet detection at 214 nm is common. Mass spectrometry is used to confirm molecular identity and detect modifications. Immunoassays exist but may not distinguish the intact peptide from fragments.