The short version of acetylated peptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-24 and is reviewed periodically as new material appears.
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.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
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.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
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。
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。
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.
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.
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.
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.
Non-road engines (or non-road mobile machinery in the European Union) are internal combustion engines that are used for other purposes than a motor vehicle that is used on a public roadway. The term is commonly used by regulators to classify the engines in order to control their emissions. Non-road engines are used in a wide range of applications which may include machinery and non-road vehicles. In many jurisdictions, the term non-road engine is assumed to refer to the engines that have mobility or portability, which is separated from the term stationary engine. The definition of non-road engine may explicitly exclude certain non-road vehicles such as aircraft, locomotives, and ocean-going marine vessels.
This reabsorption occurs throughout the tubule (most, 60–70%, of it in the proximal tubule), except in the thin segment of the loop of Henle. Circulating parathyroid hormone only influences the reabsorption that occurs in the distal tubules and the renal collecting ducts (but see Footnote). A more important effect of PTH on the kidney is, however, its inhibition of the reabsorption of phosphate (HPO42−) from the tubular fluid, resulting in a decrease in the plasma phosphate concentration. Phosphate ions form water-insoluble salts with calcium. Thus, a decrease in the phosphate concentration of the blood plasma (for a given total calcium concentration) increases the amount of calcium that is ionized. A third important effect of PTH on the kidney is its stimulation of the conversion of 25-hydroxy vitamin D into 1,25-dihydroxy vitamin D (calcitriol), which is released into the circulation. This latter form of vitamin D is the active hormone which stimulates calcium uptake from the intestine. Via the kidney, PTH enhances the absorption of calcium in the intestine by increasing the production of activated vitamin D. Vitamin D activation occurs in the kidney. PTH up-regulates 25-hydroxyvitamin D3 1-alpha-hydroxylase, the enzyme responsible for 1-alpha hydroxylation of 25-hydroxy vitamin D, converting vitamin D to its active form (1,25-dihydroxy vitamin D). This activated form of vitamin D increases the absorption of calcium (as Ca2+ ions) by the intestine via calbindin. PTH was one of the first hormones to be shown to use the G-protein adenylyl cyclase second messenger system.
== History == Lidocaine, the first amino amide–type local anesthetic (previous were amino esters), was first synthesized under the name 'xylocaine' by the team of chemist Nils Löfgren in 1943. Inga Fischer is credited for being the first to synthesize it at large-scale in the laboratory. Bengt Lundqvist performed the first injection anesthesia experiments on himself. It was first marketed in 1948 by Astra.
The longest word, hippopotomonstrosesquippedaliophobie (36 letters) is the fear (or phobia) of long words. The word is formed from the Latin word sesquipedalia (singular sesquipedalis), which the Ancient Roman poet Horace used in Ars Poetica to describe excessively long words; literally, it means "a foot-and-a-half long". Like the other phobias in the list, hippopotomonstrosesquippedaliophobie can be pluralised by adding the letter s to the end. The adjective interdépartemental (18 letters), which also appears in the list, can be made longer by appending the letters es, which gives its plural, grammatically gendered form.
Sources: en.wikipedia.org
Most classical force fields implicitly include the effect of polarizability, e.g., by scaling up the partial charges obtained from quantum chemical calculations. These partial charges are stationary with respect to the mass of the atom. But molecular dynamics simulations can explicitly model polarizability with the introduction of induced dipoles through different methods, such as Drude particles or fluctuating charges. This allows for a dynamic redistribution of charge between atoms which responds to the local chemical environment. For many years, polarizable MD simulations have been touted as the next generation. For homogenous liquids such as water, increased accuracy has been achieved through the inclusion of polarizability. Some promising results have also been achieved for proteins. However, it is still uncertain how to best approximate polarizability in a simulation. The point becomes more important when a particle experiences different environments during its simulation trajectory, e.g. translocation of a drug through a cell membrane.
=== He–Hi === Clayton Heathcock (born 1936), American chemist known for his work on the synthesis of complex polycyclic natural products Alan J. Heeger (1936–2023), American chemist known for co-founding the field of conducting polymers, 2000 Nobel Prize in chemistry Jan Baptist van Helmont (1579–1644), chemist from the Spanish Netherlands known for studying the weight gain of growing plants, The founder of pneumatic chemistry Victor Henri (1872–1940), French physical chemist of Russian parents, the first to apply ideas of physical chemistry to the properties of enzymes. Dudley R.
== Clinical significance == The gastrointestinal wall can be affected in a number of conditions. An ulcer is something that's eroded through the epithelium of the wall. Ulcers that affect the tract include peptic ulcers and perforated ulcer is one that has eroded completely through the layers. The gastrointestinal wall is inflamed in a number of conditions. This is called esophagitis, gastritis, duodenitis, ileitis, and colitis depending on the parts affected. It can be due to infections or other conditions, including coeliac disease, and inflammatory bowel disease affects the layers of the gastrointestinal tract in different ways. Ulcerative colitis involves the colonic mucosa. Crohn's disease may produce inflammation in all layers in any part of the gastrointestinal tract and so can result in transmural fistulae. Invasion of tumours through the layers of the gastrointestinal wall is used in staging of tumour spread. This affects treatment and prognosis. The normal thickness of the small intestinal wall is 3–5 mm, and 1–5 mm in the large intestine. Focal, irregular and asymmetrical gastrointestinal wall thickening suggests a malignancy. Segmental or diffuse gastrointestinal wall thickening is most often due to ischemic, inflammatory or infectious disease.
CK is often determined routinely in a medical laboratory. It used to be determined specifically in patients with chest pain to recognize acute myocardial infarction, but this test has been largely replaced by troponin. Normal values at rest are usually between 60 and 400 IU/L, where one unit is enzyme activity, more specifically the amount of enzyme that will catalyze 1 μmol of substrate per minute under specified conditions (temperature, pH, substrate concentrations and activators.) This test is not specific for the type of CK that is elevated. Creatine kinase in the blood may be high in health and disease. Exercise increases the outflow of creatine kinase to the blood stream for up to a week, and this is the most common cause of high CK in blood. Furthermore, high CK in the blood may be related to high intracellular CK such as in persons of African descent. Finally, high CK in the blood may be an indication of damage to CK-rich tissue, such as in rhabdomyolysis, myocardial infarction, myositis and myocarditis. This means creatine kinase in blood may be elevated in a wide range of clinical conditions including the use of medication such as statins; endocrine disorders such as hypothyroidism; and skeletal muscle diseases and disorders including malignant hyperthermia, and neuroleptic malignant syndrome. Furthermore, the isoenzyme determination has in the past been used extensively as an indication for myocardial damage in heart attacks. Troponin measurement has largely replaced this in many hospitals, although some centers still rely on CK-MB.
== Drafting == Declassification of British government archives has allowed scholars to piece together the choreography of the drafting of the declaration; in his widely cited 1961 book, Leonard Stein published four previous drafts of the declaration. The drafting began with Weizmann's guidance to the Zionist drafting team on its objectives in a letter dated 20 June 1917, one day following his meeting with Rothschild and Balfour. He proposed that the declaration from the British government should state: "its conviction, its desire or its intention to support Zionist aims for the creation of a Jewish national home in Palestine; no reference must be made I think to the question of the Suzerain Power because that would land the British into difficulties with the French; it must be a Zionist declaration." A month after the receipt of the much-reduced 12 July draft from Rothschild, Balfour proposed a number of mainly technical amendments. The two subsequent drafts included much more substantial amendments: the first in a late August draft by Lord Milner – one of the original five members of Lloyd George's War Cabinet as a minister without portfolio – which reduced the geographic scope from all of Palestine to "in Palestine", and the second from Milner and Amery in early October, which added the two "safeguard clauses".
Sources: en.wikipedia.org
From the earliest records regarding the use of compounds to today, the toxicity of certain substances has been described in all Chinese materiae medicae. Since TCM has become more popular in the Western world, there are increasing concerns about the potential toxicity of many traditional Chinese plants, animal parts and minerals. Traditional Chinese herbal remedies are conveniently available from grocery stores in most Chinese neighborhoods; some of these items may contain toxic ingredients, are imported into the U.S. illegally, and are associated with claims of therapeutic benefit without evidence. For most compounds, efficacy and toxicity testing are based on traditional knowledge rather than laboratory analysis. The toxicity in some cases could be confirmed by modern research (i.e., in scorpion); in some cases it could not (i.e., in Curculigo). Traditional herbal medicines can contain extremely toxic chemicals and heavy metals, and naturally occurring toxins, which can cause illness, exacerbate pre-existing poor health or result in death. Botanical misidentification of plants can cause toxic reactions in humans. The description of some plants used in TCM has changed, leading to unintended poisoning by using the wrong plants. A concern is also contaminated herbal medicines with microorganisms and fungal toxins, including aflatoxin. Traditional herbal medicines are sometimes contaminated with toxic heavy metals, including lead, arsenic, mercury and cadmium, which inflict serious health risks to consumers.
Even though the original relation was based on studies of spruce, Hankinson's equation has been found to be remarkably accurate for many other types of wood. A generalized form of the Hankinson formula has also been used for predicting the uniaxial tensile strength of wood at an angle to the grain. This formula has the form
Rheumatism (from the Ancient Greek ῥεῦμα, rheûma) or rheumatic disorders are conditions causing chronic, often intermittent pain affecting the joints or connective tissue. Rheumatism does not designate any specific disorder, but covers at least 200 different conditions, including arthritis and "non-articular rheumatism", also known as "regional pain syndrome" or "soft tissue rheumatism". There is a close overlap between the term soft tissue disorder and rheumatism. Sometimes the term "soft tissue rheumatic disorders" is used to describe these conditions. The term "Rheumatic Diseases" is used in MeSH to refer to connective tissue disorders. The branch of medicine devoted to the diagnosis and therapy of rheumatism is called rheumatology.
In June 2023, The U.S. Food and Drug Administration (FDA) authorized for marketing Eroxon, an over-the-counter non-medicated hydro-alcoholic gel indicated for treatment of erectile dysfunction. In the clinical trial, erection was achieved by most men within ten minutes after applying the gel. The gel is manufactured by Futura Medical, a British medical company. The gel is regulated as a medical device and not as a drug, because its mode of action is a physical one and it doesn't have an active pharmaceutical ingredient. Eroxon is the first topical ED treatment sold over the counter in the United States. The gel had been on sale in Europe under a CE mark since 2023, and it reached American shops in October 2024. As of 2026, the gel is sold in the United States, United Kingdom, Europe, and several countries in Latin America and the Middle East.
=== Writing === Garland began writing Dredd during post-production of his other writing credit Sunshine, and completed his first draft while serving as an executive producer during filming of 28 Weeks Later. Garland's draft revolved around one of Dredd's main enemies, the undead Judge Death. He described the story as a "riff on the whole Judge system", but that it did not work because the Judge system had not yet been established and required too much knowledge about the Judge Dredd comic from the audience. He also considered the result too surreal and extreme. From this script, Garland decided that the story needed to be more focused and grounded. He instead considered adapting some of the notable Judge Dredd storylines, including "Democracy" (1986) and "Origins" (2006). He decided to avoid these lengthy tales in favour of a shorter, day-in-the-life story about Dredd and his function as a cop in the dystopian environment of Mega-City One. When developing the Judge Dredd character, Garland tried to closely follow that of the comic-book character, who undergoes only small personality changes over a lengthy period of time. He said:
Sources: en.wikipedia.org
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.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.