The short version of 免疫调节 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-04 and is reviewed periodically as new material appears.
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.
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.
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.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
| Property | Value | Notes |
|---|---|---|
| Amino acid length | 28 residues | Single chain with an acetylated N-terminus |
| Molecular mass | Approximately 3,108 Da | Small shifts occur with counter-ion and water content |
| Isoelectric point | Around 3.5 | Low value follows from the many acidic residues |
| Parent molecule | N-terminal region of prothymosin alpha | Free circulating form in humans is not firmly established |
| Common synonyms | Thymalfasin; T alpha 1 | Older literature also uses the full spelled-out form |
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
In April 2010, the library announced plans to archive all public communication on Twitter, including all communication since Twitter's launch in March 2006. As of 2015, the Twitter archive remains unfinished. Before retiring in 2015, after 28 years of service, Billington had come "under pressure" as librarian of Congress. This followed a GAO report that described a "work environment lacking central oversight" and faulted Billington for "ignoring repeated calls to hire a chief information officer, as required by law." When Billington announced his plans to retire in 2015, commentator George Weigel described the Library of Congress as "one of the last refuges in Washington of serious bipartisanship and calm, considered conversation", and "one of the world's greatest cultural centers".
A large number of synthetic progestogens, or progestins, have been derived from progesterone and are used as medications as well. Examples include medroxyprogesterone acetate and norethisterone. In 2023, it was the 117th most commonly prescribed medication in the United States, with more than 5 million prescriptions.
PET imaging with oxygen-15 indirectly measures blood flow to the brain. In this method, increased radioactivity signal indicates increased blood flow which is assumed to correlate with increased brain activity. Because of its two-minute half-life, oxygen-15 must be piped directly from a medical cyclotron for such uses, which is difficult. PET imaging with FDG takes advantage of the fact that the brain is normally a rapid user of glucose. Standard FDG PET of the brain measures regional glucose use and can be used in neuropathological diagnosis. Brain pathologies such as Alzheimer's disease greatly decrease brain metabolism of both glucose and oxygen in tandem. Therefore FDG PET of the brain may also be used to successfully differentiate Alzheimer's disease from other dementing processes, and also to make early diagnoses of Alzheimer's disease. The advantage of FDG PET for these uses is its much wider availability. In addition, some other fluorine-18 based radioactive tracers can be used to detect amyloid-beta plaques, a potential biomarker for Alzheimer's in the brain. These include florbetapir, flutemetamol, Pittsburgh compound B (PiB) and florbetaben. PET imaging with FDG can also be used for localization of "seizure focus". A seizure focus will appear as hypometabolic during an interictal scan. Several radiotracers (i.e.
He announced his findings in the court of Queen Christina of Sweden. However, he did not publish his findings for a year, and in the interim similar findings were published by Thomas Bartholin, who additionally published that such vessels are present everywhere in the body, not just in the liver. He is also the one who named them "lymphatic vessels." This had resulted in a bitter dispute between one of Bartholin's pupils, Martin Bogdan, and Rudbeck, whom he accused of plagiarism. Galen's ideas prevailed in medicine until the 17th century. It was thought that blood was produced by the liver from chyle contaminated with ailments by the intestine and stomach, to which other organs added various spirits, and that all the other organs of the body consumed this blood. This theory required that the blood be consumed and produced many times over. Even in the 17th century, his ideas were defended by some physicians. Alexander Monro, of the University of Edinburgh Medical School, was the first to describe the function of the lymphatic system in detail. UVA School of Medicine researchers Jonathan Kipnis and Antoine Louveau discovered previously unknown vessels connecting the human brain directly to the lymphatic system. The discovery "redrew the map" of the lymphatic system, rewrote medical textbooks, and struck down long-held beliefs about how the immune system functions in the brain. The discovery may help greatly in combating neurological diseases from multiple sclerosis to Alzheimer's disease.
Sources: en.wikipedia.org
== Terminology == BLOSUM Blocks Substitution Matrix, a substitution matrix used for sequence alignment of proteins. Scoring metrics (statistical versus biological) When evaluating a sequence alignment, one would like to know how meaningful it is. This requires a scoring matrix, or a table of values that describes the probability of a biologically meaningful amino-acid or nucleotide residue-pair occurring in an alignment. Scores for each position are obtained frequencies of substitutions in blocks of local alignments of protein sequences. BLOSUM r
==== Pandemic unemployment fraud and debt ==== In January 2021, the Los Angeles Times reported that Newsom's administration had mismanaged $11.4 billion by disbursing unemployment benefits to ineligible claimants, especially those paid through the federally funded Pandemic Unemployment Assistance program. Another $19 billion in claims remained under investigation for fraud. At the same time, legitimate claimants faced lengthy delays in receiving benefits. The state's unemployment system had been overseen by California Labor Secretary Julie Su, a Newsom appointee, whom President Joe Biden later appointed as deputy secretary of labor in February 2021. Political opponents attributed the crisis to the Newsom administration's failure to heed multiple warnings by federal officials of the potential for fraud, while Newsom's administration said the Trump administration's failure to provide appropriate guidance for the new federally funded program contributed to the fraud. Experts said much of the fraud appeared to originate from international criminal gangs in 20 countries. A report by California State Auditor Elaine Howle said $810 million was disbursed to claimants who had fraudulently filed on behalf of inmates in the state's prison system. According to The Sacramento Bee, by the summer of 2021, California owed $23 billion to the federal government for unemployment benefits paid out during the pandemic, which was 43% of all unemployment debt, owed by 13 states at the time, to the federal government.
The central region of the coronal and radicular pulp contains large nerve trunks and blood vessels. This area is lined peripherally by a specialized odontogenic area which has four layers (from innermost to outermost):
The proposed 2 World Trade Center breaks ground in Lower Manhattan in New York City, New York, U.S., 25 years after the original building was destroyed during the September 11 attacks. July 10 2026 United States Senate elections: Graham Platner officially withdraws from the Senate race in Maine, with the Maine Secretary of State’s Office confirming his withdrawal. The Trump administration loosens export controls on the UAE. July 11 Housing in the United States: The 21st Century ROAD to Housing Act, a piece of legislation passed in the U.S. Congress to expand affordable housing and reduce housing costs in the United States, becomes law after U.S. president Donald Trump allows the bill to take effect without his signature. Iran war: Iran's IRGC navy says that it has closed the Strait until further notice after firing a warning shot at a vessel trying to transit through an unapproved route. Republican U.S. senator Lindsey Graham of South Carolina dies at his home in Washington, D.C., aged 71, following a brief and sudden illness. His death creates a vacancy in the United States Senate, with Governor Henry McMaster to appoint a temporary successor ahead of a special Republican primary to replace Graham as the party's nominee in the November election. July 12 2026 Iran war: The US Central Command says that the Iranian attack significantly damaged a Cyprus-flagged container vessel and a crew member went missing. Britain's military says that the vessel was nine nautical miles east of Oman and the attack forced the crew to abandon the vessel.
== Decay == Uranium-238 is an alpha emitter, producing thorium-234 which is a beta emitter, etc. This leads to a decay chain, commonly called the radium series or uranium series. Beginning with naturally occurring uranium-238, this series includes isotopes of astatine, bismuth, lead, polonium, protactinium, radium, radon, thallium, thorium and uranium, all of which are present in natural uranium sources. The decay proceeds as (only main decay branches shown):
Sources: en.wikipedia.org
It is usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.
Prothymosin alpha is a much larger acidic protein, roughly 111 to 113 residues long, and the thymosin alpha-1 sequence matches its N-terminal region. The small peptide is therefore best understood as a fragment of that parent protein rather than a separate gene product.
Trials and clinical reports have examined chronic hepatitis B and C, use as a vaccine adjuvant, and supportive treatment in some immunodeficiency and oncology settings. Results vary by indication, and regulatory approval differs between countries.
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.