This is a working overview of certificate of analysis, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-03 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。
Identity and purity are normally assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities and truncation products. Mass spectrometry confirms molecular mass and detects modifications such as deamidation or oxidation. Amino acid analysis and peptide mapping provide additional sequence-level confirmation. For research material, a certificate of analysis typically reports these results together with water content and counter-ion identity, since the lyophilized powder is often supplied as an acetate or trifluoroacetate salt.
Several factors accelerate degradation: alkaline pH, elevated temperature, exposure to oxidants, and the presence of residual moisture. Deamidation of asparagine residues and oxidation of methionine are the most commonly reported degradation routes. Because the peptide lacks disulfide bonds, it does not undergo the thiol-related aggregation seen in some other biologics, but physical aggregation can still occur at high concentration. Stability data are product-specific, and extrapolating shelf life between formulations is not reliable.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
| 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 |
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.
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.
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
=== Other benefits === Pre-workout has shown to make athletes feel more energetic during exercise, but the higher energy levels are based on subjective judgement and there is little quantitative proof of an increase in energy. Caffeine's role in enhancing the improvement in perceived energy is observed through the large amounts of caffeine typically found in pre-workout supplements. Caffeine also increases calcium release which allows for stronger muscle contractions during high intensity workouts. Studies also show that the caffeine in pre-workout improves focus and alertness in athletes as observed through a decrease in reaction-time in different settings.
== Calculation == The BSE has some reviews and modifies its composition to be sure it reflects current market conditions. The index is calculated based on a free float capitalisation method, a variation of the market capitalisation method. Instead of using a company's outstanding shares it uses its float, or shares that are readily available for trading. Free Floating capital implies total capitalization less Directors shareholding. As per free float capitalisation methodology, the level of index at any point of time reflects the free float market value of 30 constituent stocks relative to a base period. The market capitalisation of a company is determined by multiplying the price of its stock by the number of shares issued by corporate actions, replacement of scrips. The index has increased by over twenty five times from June 1990 to the present. Using information from April 1979 onwards, the long-run rate of return on the S&P BSE SENSEX works 18.6% per annum.
=== Macau === The Portuguese Macau government seldom interfered in the affairs of Chinese society, including with regard to regulations on the practice of TCM. There were a few TCM pharmacies in Macau during the colonial period. In 1994, the Portuguese Macau government published Decree-Law no. 53/94/M that officially started to regulate the TCM market. After the sovereign handover, the Macau S.A.R. government also published regulations on the practice of TCM. In 2000, Macau University of Science and Technology and Nanjing University of Traditional Chinese Medicine established the Macau College of Traditional Chinese Medicine to offer a degree course in Chinese medicine. In 2022, a new law regulating TCM, Law no. 11/2021, came into effect. The same law also repealed Decree-Law no. 53/94/M.
=== Legal categorization and legal issues in a near future === Currently, siRNAs are chemically synthesized and are therefore legally categorized in the EU and the US as simple medicinal products. But as bioengineered siRNA (BERAs) are in development, these would be classified as biological medicinal products, at least in the EU. The development of the BERAs technology raises the question of the categorization of drugs having the same mechanism of action but being produced chemically or biologically. This lack of consistency should be addressed.
Sources: en.wikipedia.org
== External links == "P2Y Receptors: P2Y2". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2008-12-09. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
On 17 February, an Israeli drone strike hit a car in Sidon, killing Mohammed Shaheen, Hamas's operations chief in Lebanon. On the ceasefire's deadline on 18 February, the IDF withdrew from all of southern Lebanon, apart from five hilltops on the border—namely al-Aziyah, al-Awaida, el-Hamames, Jabal Bilat, and Labbouneh. On 22 March, six rockets were fired at Metula from southern Lebanon, with three crashing in Lebanon and the rest being intercepted. Hezbollah denied responsibility for the attack. The IDF responded with strikes on dozens of Hezbollah targets across southern Lebanon, including rocket launchers. On 25 March, an Israeli drone strike on a vehicle in Qaaqaait al-Jisr killed Hassan Kamal Halawi, who commanded Hezbollah's anti-tank missile unit in southern Lebanon. On 28 March, two rockets were fired at Kiryat Shmona, with one falling short in Lebanon and the other being intercepted. In response, the IDF said that it struck several Hezbollah targets in southern Lebanon, including command centers. A strike in Kfar Tebnit killed three people and injured 18 others. An airstrike also hit a building in Dahieh that the IDF accused of storing drones from Hezbollah's Unit 127, in the first attack in Beirut since the ceasefire went into effect. On 1 April, an Israeli airstrike on an apartment in Dahieh killed four people and injured seven others. Among the dead were senior Hezbollah official Hassan Bdeir, who the IDF accused of planning to attack Israeli civilians alongside Hamas, and his son, who was a Hezbollah member.
==== Above-ground disposal ==== Dry cask storage typically involves taking waste from a spent fuel pool and sealing it (along with an inert gas) in a steel cylinder, which is placed in a concrete cylinder which acts as a radiation shield. It is a relatively inexpensive method which can be done at a central facility or adjacent to the source reactor. The waste can be easily retrieved for reprocessing.
Lente insulin (derived from the Italian word lento, meaning "slow"), also known as insulin zinc suspension, was an intermediate-acting insulin that is no longer used in humans. Its effects begin one to two hours after administration, with peak activity occurring approximately 8 to 12 hours post-injection, and some residual effects lasting beyond 24 hours. Manufacturers discontinued Lente insulin and other similar insulin analogs in the mid-2000s, and it is no longer approved for human use in the United States. This decision was partly due to the medical community's preference for more predictable insulin formulations, such as recombinant NPH insulin. Similarly to the modern brands of NPH and regular insulin, which are still sold, lente insulins would be marketed under the name of the rest of the insulins in a brand's product line, followed by the letter L.
One or more of the disulfide bonds that join the heavy chains in the hinge region are preserved, so the two Fab regions of the antibody remain joined together, yielding a divalent molecule (containing two antibody binding sites), hence the designation F(ab')2. The light chains remain intact and attached to the heavy chain. The Fc fragment is digested into small peptides. Fab fragments are generated by cleavage of IgG with papain instead of pepsin. Papain cleaves IgG above the hinge region containing the disulfide bonds that join the heavy chains, but below the site of the disulfide bond between the light chain and heavy chain. This generates two separate monovalent (containing a single antibody binding site) Fab fragments and an intact Fc fragment. The fragments can be purified by gel filtration, ion exchange, or affinity chromatography. Fab and F(ab')2 antibody fragments are used in assay systems where the presence of the Fc region may cause problems. In tissues such as lymph nodes or spleen, or in peripheral blood preparations, cells with Fc receptors (macrophages, monocytes, B lymphocytes, and natural killer cells) are present, which can bind the Fc region of intact antibodies, causing background staining in areas that do not contain the target antigen. Use of F(ab')2 or Fab fragments ensures that the antibodies are binding to the antigen and not Fc receptors. These fragments may also be desirable for staining cell preparations in the presence of plasma, because they are not able to bind complement, which could lyse the cells.
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。
Dry lyophilized powder tolerates short ambient exposure during handling and shipping. Long-term room-temperature storage is not recommended because moisture uptake and slow degradation can occur over months. Storage at minus twenty degrees Celsius is the common practice for extended periods.