Everything below concerns 合成肽. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
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 |
|---|---|---|
| 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 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
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.
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.
A protein subunit is a polypeptide chain or protein molecule that assembles (or "coassembles") with other protein molecules to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A key step in creating a recombinant protein vaccine is the identification and isolation of a protein subunit from the pathogen which is likely to trigger a strong and effective immune response, without including the parts of the virus or bacterium that enable the pathogen to reproduce. Parts of the protein shell or capsid of a virus are often suitable. The goal is for the protein subunit to prime the immune system response by mimicking the appearance but not the action of the pathogen. Another protein-based approach involves self‐assembly of multiple protein subunits into a virus-like particle (VLP) or nanoparticle. The purpose of increasing the vaccine's surface similarity to a whole virus particle (but not its ability to spread) is to trigger a stronger immune response. Protein subunit vaccines are generally made through protein production, manipulating the gene expression of an organism so that it expresses large amounts of a recombinant gene. A variety of approaches can be used for development depending on the vaccine involved. Yeast, baculovirus, or mammalian cell cultures can be used to produce large amounts of proteins in vitro. Protein-based vaccines are being used for hepatitis B and for human papillomavirus (HPV).
=== Sports === Current evidence-based studies show that unusually high levels of circulating testosterone are associated with increased athletic performance in women, unless they lack androgen sensitivity. However, controversy has emerged in the form of the claim that testosterone is not unlike any other physical parameter with reference to bestowing advantages or disadvantages on female athletes. Existing regulations throughout competitive sports are currently being refined to specifically address this particular claim. Following the case of South African athlete Caster Semenya, an athlete with a difference in sex development (DSD) and internal testes, the International Association of Athletics Federations introduced its hyperandrogenism regulations, which restricted those registered as women with high testosterone levels, whether the hormones were produced by ovaries, adrenals, or testes. These regulations replaced the earlier sex verification rules. Following a series of legal challenges, regulations called the Eligibility Regulations for the Female Classification (Athletes with Differences of Sexual Development) were released on 1 May 2019. These regulations apply only to athletes who have a DSD, high testosterone and virilization, and no longer include hyperandrogenism from non-DSD-related causes such as PMOS. Such DSDs, often seen in people who have a Y chromosome and testes, include 5α‐reductase deficiency, partial androgen insensitivity, and congenital adrenal hyperplasia.
== Sources == Joan E. Howard, From Violence to Vision: Sacrifice in the Works of Marguerite Yourcenar (1992) Josyane Savigneau, Marguerite Yourcenar: Inventing a Life (1993). George Rousseau, Marguerite Yourcenar: A Biography (London: Haus Publishing, 2004). Judith Holland Sarnecki, Subversive Subjects: Reading Marguerite Yourcenar (2004) Giorgetto Giorgi, "Il Grand Tour e la scoperta dell’antico nel Labyrinthe du monde di Marguerite Yourcenar," in Sergio Audano, Giovanni Cipriani (ed.), Aspetti della Fortuna dell'Antico nella Cultura Europea: atti della settima giornata di studi, Sestri Levante, 19 March 2010 (Foggia: Edizioni il Castello, 2011) (Echo, 1), 99–108. Les yeux ouverts, entretiens avec Mathieu Galey (Éditions du Centurion « Les interviews », 1980). Bérengère Deprez, Marguerite Yourcenar et les États-Unis. Du nageur à la vague, Éditions Racine, 2012, 192 p. Bérengère Deprez, Marguerite Yourcenar and the United States. From Prophecy to Protest, Peter Lang, coll. « Yourcenar », 2009, 180 p. Deprez, Marguerite Yourcenar. Écriture, maternité, démiurgie, essai, Bruxelles, Archives et musée de la littérature/PIE-Peter Lang, coll. « Documents pour l’histoire des francophonies », 2003, 330 p. Donata Spadaro, Marguerite Yourcenar et l'écriture autobiographique : Le Labyrinthe du monde, bull. SIEY, no 17, décembre 1996, p. 69 à 83 Donata Spadaro, Marguerite Yourcenar e l'autobiografia (ADP, 2014) Mireille Brémond, Marguerite Yourcenar, une femme à l'Académie (Garnier, 2019);. Rémy Poignault, L'Antiquité dans l'œuvre de Marguerite Yourcenar.
Sources: en.wikipedia.org
Between 1981 and 1987, the relationship between Noriega and the U.S. grew considerably. It was driven both by the U.S.'s pursuit of its security interests, and Noriega using these as an effective means of gaining favor. The emergence of internal conflicts in Nicaragua and El Salvador between 1979 and 1981 led the Reagan administration to look for allies in the region, including in Panama. Noriega acted as a conduit for U.S. support, including funds and weapons, to the Contra rebels in Nicaragua. He allowed the CIA to establish listening posts in Panama, and also helped the U.S.-backed Salvadoran government against the leftist Salvadoran insurgent Farabundo Martí National Liberation Front. U.S. spy ships used bases in Panama in their operations against the Nicaraguan government, and much of the intelligence gathered by these ships was processed in the U.S. bases in Panama. Noriega permitted these activities despite the Panama Canal treaties restricting the use of the U.S. bases to protecting the canal. Bush, now U.S. vice president, met again with Noriega in December 1983 to discuss support for the Contras. Noriega had a working relationship with U.S. Marine Corps Lieutenant Colonel Oliver North by 1985. Noriega offered to assassinate or sabotage Sandinista leaders in return for North helping Noriega improve his image with the U.S. government. In June 1985 North met with Noriega in Panama and Noriega agreed to train Contra soldiers in Panama for an invasion of Nicaragua in 1986. In return for Panama's support for U.S.
Throughout the many hymns, prayers, and philosophy found in the Vedas (written around 1500 BC), a mysterious plant is mentioned often and with great reverence. This plant alternates from a holy substance to an actual personified god and is considered a teacher, doctor, medicine, a bringer of insight, and a vector of inspiration. The deity version of Soma was associated with medicinal herbs and the moon and was considered a bringer of health and prosperity. The plant was an essential aspect of Vedic religion to alter one’s mind, enabling communion with the divine. The ritual drinking of Soma is also mentioned in the ancient Zoroastrian text, the Avesta, where the rituals and importance of the plant are very similar to those in Vedic culture but are instead called by the name haoma. It is unknown why, but eventually in both the Vedic and Zoroastrian cultures a substitute substance was used in these religious ceremonies and over time the definitive identity of Soma-Haoma has been lost. There is much debate over which species of plant are the sacred plant of the Vedic and Zoroastrian faiths.
de novo mutation A spontaneous mutation in the genome of an individual organism that is new to that organism's lineage, having first appeared in a germ cell of one of the organism's parents or in the fertilized egg that develops into the organism; i.e. a mutation that was not present in either parent's genome.
Sources: en.wikipedia.org
While a number of wholesale markets observed the shutdown, the newspaper claimed a majority of kirana stores and neighborhood small shops – for whom apparently the trade bandh had been called – remained open, ignoring the shutdown call. Conflicting claims were made by the organisers of the nationwide shutdown. Contrary to eyewitness reports, one Trader union's secretary general claimed traders across the country participated wholeheartedly in the strike. The political parties opposing the retail reforms physically disrupted and forced India's parliament to adjourn again on Friday 2 December 2011. The Indian government refused to cave in, in its attempt to convince through dialogue that retail reforms are necessary to protect the farmers and consumers. Indian parliament has been dysfunctional for the entire week of 28 November 2011 over the opposition to retail reforms.
== Production == One method for industrial production of dried cherries involves first dipping them in a boiling 0.5–2% solution of sodium carbonate (NaCO3) for up to 20 seconds, and then rinsing in cool water; this induces small cracks in the skin and speeds up the drying process. Some other possible materials for the dipping solution include ethyl oleate and oleyl alcohol; adding alkalis like potassium carbonate (K2CO3) to such a dip was shown to have no positive effect on drying time. Such results had already been demonstrated in scientific research by the 1940s. Dried cherries might also be produced by freeze drying or air drying. After drying, they typically have a moisture content of around 25%. Adding sulfur dioxide (SO2) may help to improve color and flavour retention over long periods of storage. Sweet varieties recommended for drying include Lambert, Royal Ann, Napoleon, Van, or Bing; tart varieties recommended for drying include Early Richmond or Large Montmorency. Most cherries sold in North America are sour varieties (either Montmorency or Morello). The first recorded experiments attempting to dry Montmorency tart cherries were performed in the late 1970s by professors at Utah State University. After drying the cherries, they were rolled in sugar and then sampled as "snow cherries".
It could be used to detect trace contaminants in environmental samples, to identify drugs in a case of overdose, and to measure drug metabolites. After the United States Environmental Protection Agency (EPA) was established in 1970, it became a major customer for Finnigan's GC/MS. The EPA surveyed possible monitoring instruments for use in monitoring organic pollutants. Speed, cost, and performance were all important concerns. The target machine was projected as having the ability to scan for pesticides with a resolving power of 1,000 to 10,000, across a broad range of 10 nanograms to one microgram. A computer-controlled system was desirable. An international array of instruments were reviewed, of which only two used quadrupole technology. An expert panel recommended Finnigan's quadrupole GC/MS to the EPA for further evaluation, and twenty Finnigan Model 1015/System 150 instruments were ordered soon after by the EPA. Finnigan published a 1979 study, based on users, indicating that in spite of the high initial cost of the equipment, the Finnigan GC/MS was reliable and cost-effective. By 1979, the Finnigan GC/MS was the preferred instrument at the EPA for the analysis of environmental pollutants in water and wastewater. The models most generally used were Finnigan Corporation's 1015 and 3000 series of quadrupole mass spectrometers with a data system based on DEC's PDP-8 computers. The EPA also based its instruction manuals and standards for environmental testing on the Finnigan GC/MS, publishing the results in the Federal Register in 1979.
=== Biosynthesis === Estradiol, like other steroid hormones, is derived from cholesterol. After side chain cleavage and using the Δ5 or the Δ4- pathway, androstenedione is the key intermediary. A portion of the androstenedione is converted to testosterone, which in turn undergoes conversion to estradiol by aromatase. In an alternative pathway, androstenedione is aromatized to estrone, which is subsequently converted to estradiol via 17β-hydroxysteroid dehydrogenase (17β-HSD). During the reproductive years, most estradiol in women is produced by the granulosa cells of the ovaries by the aromatization of androstenedione (produced in the theca folliculi cells) to estrone, followed by conversion of estrone to estradiol by 17β-HSD. Smaller amounts of estradiol are also produced by the adrenal cortex, and, in men, by the testes. Estradiol is not produced in the gonads only; in particular, fat cells produce active precursors to estradiol, and will continue to do so even after menopause. Estradiol is also produced in the brain and in arterial walls. In men, approximately 15 to 25% of circulating estradiol is produced in the testicles. The rest is synthesized via peripheral aromatization of testosterone into estradiol and of androstenedione into estrone (which is then transformed into estradiol via peripheral 17β-HSD). This peripheral aromatization occurs predominantly in adipose tissue, but also occurs in other tissues such as bone, liver, and the brain. Approximately 40 to 50 μg of estradiol is produced per day in men.
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。
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.