reconstitution raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-13 and is reviewed periodically as new material appears.
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。
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
| 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 short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
Identity and purity are normally confirmed by reversed-phase high-performance liquid chromatography and mass spectrometry. The expected mass for the acetylated 28-residue peptide is close to 3108 daltons, and a mass shift indicates a modification or truncation. Peptide mapping after enzymatic digestion can resolve sequence-level questions. Counter-ion content, water content, and residual solvents are separate quality attributes that a certificate of analysis may or may not report. Aggregation is monitored by size-exclusion chromatography when relevant.
Another important element of the political crisis was the spectacular growth of independentism in Catalonia following the publication in late June 2010 of the Sentence of the Constitutional Court on the Statute of Autonomy of Catalonia of 2006, which after four years of deliberations dealt a severe blow to the aspirations of Catalan nationalism. On July 9, 2010, there was a big demonstration of rejection to the sentence with the slogan Som una nació, nosaltres decidim, which resulted in a plebiscite in favor of independence. Four months later, the Catalan Parliament elections were held, which were won by CiU and its leader Artur Mas was invested as the new president of the Generalitat. The change of government in Euskadi after the 2009 Basque Parliament elections — the Socialist Patxi López replaced the peneuvist Juan José Ibarretxe — the departure from the institutions of the groups inherited from Batasuna and the effectiveness of the security forces and corps in the fight against ETA – in less than two years, all the members of the leadership that had imposed in 2007 the breaking of the truce were arrested – among other reasons, forced the nationalist left to rethink its political strategy. Thus, in February 2010, Batasuna presented a first document in which it supported a "democratic process in the absence of violence", which was followed by the denominated "Brussels Declaration" in which an international intermediary group headed by the South African lawyer Brian Currin called on ETA to declare a permanent ceasefire.
== Etymology == The etymology of the common name "emu" is uncertain, but is thought to have come from an Arabic word for large bird that was later used by Portuguese explorers to describe the related cassowary in Australia and New Guinea. Another theory is that it comes from the word "ema", which is used in Portuguese to denote a large bird akin to an ostrich or crane. In Victoria, some terms for the emu were Barrimal in the Dja Dja Wurrung language, myoure in Gunai, and courn in Jardwadjali. The birds were known as murawung or birabayin to the local Eora and Darug inhabitants of the Sydney basin.
=== Timeline === Mixue Ice Cream & Tea began in 1997 when Zhang Hongchao opened the first location under the Mixue name. After six relocations, the first successful Mixue Ice Cream & Tea store opened in 2003. Around 2005 or 2006, the company introduced soft serve ice cream at the price of just CN¥1, this quickly became a best-seller and its first signature product. In 2007, Mixue began franchising after opening a new ice cream shop. The following year, it established Mixue Ice Cream & Tea Trading Co., Ltd. to manage its growing network of franchises. Mixue took its first step outside of China on September 5, 2018, with a store opening in Hanoi, Vietnam. Later that year, in November, it launched a new brand mascot, Snow King. Between May 24 and 26, 2019, the company hosted an "ice cream music festival" at Opalala Water Park in Zhengzhou, drawing over 30,000 visitors. On June 24, 2020, Mixue celebrated the opening of its 10,000th store in Yuanyang County, Henan, Xinxiang. The same year, it expanded into Indonesia with a branch in Cihampelas Walk, Bandung. In 2022, Mixue made significant purchases of over 9,000 tonnes (8,900 long tons; 9,900 short tons) of tea, benefiting around 50,000 tea farmers, while also supporting over 11,000 franchisees and generating more than 500,000 jobs. It launched a CN¥6.5 million scholarship program across five universities in Henan and expanded into additional Southeast Asian markets, opening stores in Singapore, Thailand, Cambodia, Philippines, Laos, and Myanmar. By the end of 2022, Mixue had also entered South Korea and Japan.
Sources: en.wikipedia.org
Heseltine also favoured European cooperation in defence procurement, feeling that this allowed Europe to compete with US firms which receive huge orders from The Pentagon. Crick argues that his experience of Concorde in the early 1970s should have warned him that such multinational ventures are problematic and, because of the political capital invested, hard to cancel when things go wrong. Heseltine played an important role in persuading West German defence minister Manfred Wörner to back the joint Anglo-German-Spanish-Italian Eurofighter, and contrary to the wishes of Thatcher (and previous defence secretary John Nott) who preferred an American or British fighter. Cabinet refused to allow a loosening of the specifications to allow French company Dassault to become involved in the consortium. Agreement was reached at Turin in August 1985. Heseltine also sold 132 Tornados for £4bn to Saudi Arabia later in 1985, accepting oil instead of cash (to the displeasure of Peter Walker, Energy Secretary) so that they would buy British rather than US aircraft. This later formed part of the controversial Al-Yamamah arms deal, the main part of which was signed in 1988.
Pea protein is a food product and protein supplement derived and extracted from yellow and green split peas, Pisum sativum. It can be used as a dietary supplement to increase an individual's protein or other nutrient intake, or as a substitute for other food products (e.g. the substitution of dairy milk by pea milk). As a powder, it is used as an ingredient in food manufacturing, such as a thickener, foaming agent, or an emulsifier. It is extracted in a powder form and can be processed and produced in different ways:
== Side effects and withdrawal from market == On April 7, 2005, Pfizer withdrew Bextra from the U.S. market on recommendation by the FDA, citing an increased risk of heart attack and stroke and also the risk of a serious, sometimes fatal, skin reaction. This was a result of recent attention to prescription NSAIDs, such as Merck's Vioxx. Other reported side effects were angina and Stevens–Johnson syndrome. Pfizer first acknowledged cardiovascular risks associated with Bextra in October 2004. The American Heart Association soon after was presented with a report indicating patients using Bextra while recovering from heart surgery were 2.19 times more likely to suffer a stroke or heart attack than those taking placebos. In a large study published in The Journal of the American Medical Association in 2006, valdecoxib appeared less adverse for renal (kidney) disease and heart arrhythmia compared to Vioxx, but elevated renal risks were slightly suggested.
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 lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.