If you have been reading about 合成肽 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
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.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
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.
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.
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 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.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
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.
== Principle == An HID connected to a gas chromatograph (GC) has the great advantage to use helium as both the carrier gas and the ionization gas. An HID is an ion detector which uses a radioactive source, typically β-emitters, to create metastable helium species. The radioactive source ionizes helium atoms by bombarding them with emissions. The metastable helium species have an energy of up to 19.8 eV. These metastable helium species can ionize all compounds with the exception of neon which has a greater ionization potential of 21.56 eV. As components elute from the GC's column they collide with the metastable helium ions, which then ionize the components. The ions produce an electric current, which is the signal output of the detector. The greater the concentration of the component, the more ions are produced, and the greater the current.
== Biological function == Lysyl oxidase is an extracellular copper-dependent enzyme that catalyzes formation of aldehydes from lysine residues in collagen and elastin precursors. These aldehydes react with unmodified lysine residues, resulting in cross-linking collagen and elastin, which is essential for stabilization of collagen fibrils and for the integrity and elasticity of mature elastin. Complex cross-links are formed in collagen (pyridinolines derived from three lysine residues) and in elastin (desmosines derived from four lysine residues) that differ in structure. The importance of lysyl oxidase-derived cross-linking was established from animal studies in which lysyl oxidase was inhibited either by nutritional copper-deficiency or by supplementation of diets with β-aminopropionitrile (BAPN), an inhibitor of lysyl oxidase. This resulted in lathyrism, characterized by poor bone formation and strength, hyperextensible skin, weak ligaments, and increased occurrence of aortic aneurysms. These abnormalities correlated well with decreased cross-linking of collagen and elastin. Developmentally, reduced lysyl oxidase activity have been implicated in Menkes disease and occipital horn syndrome, two X-linked recessive disorders characterized by a mutation in a gene coding for a protein involved in copper transport. Thus, not only is LOX crucial to cardiovascular development, it plays a major role in connective tissue development and may also be important in neurological function.
Single shot semi-automatic, in which the gunner can shoot as fast as the trigger can be operated, limited only by the electrical drive speed (it cannot exceed the "high rate" firing speed). Low rate fully automatic, in which the weapon fires 100 rounds per minute, ± 25 rounds. High rate fully automatic, in which the weapon fires 200 rounds per minute, ± 25 rounds.
Sources: en.wikipedia.org
When the difference between successive pK values is about four or more, as in this example, each species may be considered as an acid in its own right; In fact salts of H2PO−4 may be crystallised from solution by adjustment of pH to about 5.5 and salts of HPO2−4 may be crystallised from solution by adjustment of pH to about 10. The species distribution diagram shows that the concentrations of the two ions are maximum at pH 5.5 and 10.
Yukio Ninagawa staged a production called Ohjo Media (王女メディア) in 1978, followed by a second version in 2005. In 1982, George Eugeniou at Theatro Technis London directed Medea as a barefooted unwanted refugee played with "fierce agility" and "dangerous passions" by Angelique Rockas. In 1983, kabuki Master Shozo Sato created Kabuki Medea uniting Euripides' play and classical Kabuki storytelling and presentation. It debuted at Wisdom Bridge Theater in Chicago. The 1990 play Pecong, by Steve Carter, is a retelling of Medea set on a fictional Caribbean island around the turn of the 20th century The play was staged at the Wyndham's Theatre in London's West End, in a translation by Alistair Elliot. The production opened on 19 October 1993. Chrysanthos Mentis Bostantzoglou makes a parody of this tragedy in his comedy Medea (1993). A 1993 dance-theatre retelling of the Medea myth was produced by Edafos Dance Theatre, directed by avant-garde stage director and choreographer Dimitris Papaioannou. John Fisher wrote a camp musical version of Medea entitled Medea the Musical that re-interpreted the play in light of gay culture. The production was first staged in 1994 in Berkeley, California. Christopher Durang and Wendy Wasserstein co-wrote a sketch version for the Juilliard School's Drama division 25th Anniversary. It premiered 25 April 1994, at the Juilliard Theater, New York City.
Physical optics: The intensity of electromagnetic radiation such as light or X-rays or gamma rays in an absorbent medium, follows an exponential decrease with distance into the absorbing medium. This is known as the Beer-Lambert law. Radioactivity: In a sample of a radionuclide that undergoes radioactive decay to a different state, the number of atoms in the original state follows exponential decay as long as the remaining number of atoms is large. The decay product is termed a radiogenic nuclide. Thermoelectricity: The decline in resistance of a Negative Temperature Coefficient Thermistor as temperature is increased. Vibrations: Some vibrations may decay exponentially; this characteristic is often found in damped mechanical oscillators, and used in creating ADSR envelopes in synthesizers. An overdamped system will simply return to equilibrium via an exponential decay. Beer froth: Arnd Leike, of LMU Munich, won an Ig Nobel Prize for demonstrating that beer froth obeys the law of exponential decay. Automobile braking is a universal example of exponential decay, and variation of the mathematical exponentials and functions which the foot applies are important to the comfort of the occupants and the avoidance of accidents.
Sources: en.wikipedia.org
==== Corneal Allogenic Intrastromal Ring Segments (CAIRS) ==== Corneal Allogenic Intrastromal Ring Segment Keratoplasty (CAIRS Keratoplasty) is a modern surgical technique used in the treatment of keratoconus. It involves implanting finely shaped pieces of donor corneal tissue into the corneal stroma to reinforce and reshape the weakened, ectatic cornea, thereby improving both corneal structure and visual clarity. Because CAIRS uses biological graft material and has demonstrated strong outcomes with a favourable safety profile, it is formally recognised as a corneal transplantation procedure by health funding authorities in Australia, the United Kingdom, Japan, Germany, Brazil, the Netherlands, and a number of other countries. In contrast to traditional synthetic intrastromal corneal ring segments (ICRS) made from materials such as PMMA, CAIRS keratoplasty uses preserved allogeneic corneal tissue. This biological compatibility reduces the likelihood of complications sometimes seen with non-organic implants, including extrusion, infection, or chronic foreign body reaction. The CAIRS technique was pioneered by Dr Soosan Jacob, who first introduced it in 2018 through a large case series published in the Journal of Refractive Surgery. One of its key strengths is its suitability for corneas with irregular or decentered cones. The donor segments can be individually designed to achieve targeted corneal flattening and astigmatism improvement.
== Side effects == Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear. A new wave of fentanyl analogues and associated deaths began in around 2014 in the US, and have continued to grow in prevalence. Since 2016 these drugs have been responsible for hundreds of overdose deaths every week.
=== Production of other elements === Americium is a starting material for the production of other transuranic elements and transactinides – for example, 82.7% of 242Am decays to 242Cm and 17.3% to 242Pu. In the nuclear reactor, 242Am is also up-converted by neutron capture to 243Am and 244Am, which transforms by β-decay to 244Cm:
== Adverse effects == The most common adverse drug reactions include headache, nasal and throat irritation (nasopharyngitis), urinary tract infection, nausea, and fever (pyrexia). The most common side effect in clinical trials was headache (in about 10% of people who take it). Less common side effects (between 1 and 10% of people) included unspecific symptoms such as dizziness, fatigue, and nausea, but also depression. Possible rare side effects could not be assessed because of the low number of subjects in the clinical trials in which adverse effects were measured.
Sources: en.wikipedia.org
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
The name reflects an early convention for naming thymus-derived fractions. The peptide is characterized and measured as a defined molecule, and it does not operate through a single classical endocrine axis.