Everything below concerns thymosin alpha 1. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-11. 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。
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 |
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.
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.
Storage recommendations center on low temperature, dryness, and protection from repeated freezing and thawing. The intact powder is commonly held at 20 degrees below zero Celsius or colder, while a working solution is divided into single-use aliquots to limit freeze-thaw cycles. Buffered saline or phosphate-buffered saline at neutral pH is frequently used as a diluent. Light sensitivity is not well documented, yet amber vials or foil wrapping are common practice for long-term storage of peptide stocks.
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.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
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.
Confirming a diagnosis of carotid artery stenosis is important because the treatment for this condition, carotid endarterectomy, can pose significant risk to the patient, including heart attacks and strokes after the procedure. For this reason, the U.S. Preventive Services Task Force (USPSTF) "recommends against screening for asymptomatic carotid artery stenosis in the general adult population". This recommendation is for asymptomatic patients, so it does not necessarily apply to patients with TIAs as these may in fact be a symptom of underlying carotid artery disease (see "Causes and Pathogenesis" above). Therefore, patients who have had a TIA may opt to have a discussion with their clinician about the risks and benefits of screening for carotid artery stenosis, including the risks of surgical treatment of this condition. Cardiac imaging can be performed if head and neck imaging do not reveal a vascular cause for the patient's TIA (such as atherosclerosis of the carotid artery or other major vessels of the head and neck). Echocardiography can be performed to identify patent foramen ovale (PFO), valvular stenosis, and atherosclerosis of the aortic arch that could be sources of clots causing TIAs, with transesophageal echocardiography being more sensitive than transthoracic echocardiography in identifying these lesions.
=== Main group elements and lanthanides === The mechanisms of main group compounds of groups 13–18 are usually discussed in the context of organic chemistry (organic compounds are main group compounds, after all). Elements heavier than C, N, O, and F often form compounds with more electrons than predicted by the octet rule, as explained in the article on hypervalent molecules. The mechanisms of their reactions differ from organic compounds for this reason. Elements lighter than carbon (B, Be, Li) as well as Al and Mg often form electron-deficient structures that are electronically akin to carbocations. Such electron-deficient species tend to react via associative pathways. The chemistry of the lanthanides mirrors many aspects of chemistry seen for aluminium.
=== Military restructuring === Spain's international wars in the second half of the 18th century evidenced the empire's difficulties in reinforcing its colonial possessions and provide them with economic aid. This led to an increased local participation in the financing of the defense and an increased participation in the militias by the locally-born. Such development was at odds with the ideals of the centralized absolute monarchy. The Spanish did also formal concessions to strengthen the defense: In Chiloé Archipelago Spanish authorities promised freedom from the encomienda to those indigenous locals who settled near the new stronghold of Ancud (founded in 1768) and contributed to its defense. The increased local organization of the defenses would ultimately undermine metropolitan authority and bolster the independence movement.
Thallium is the heaviest stable element in group 13 of the periodic table. At the bottom of the periodic table, the inert-pair effect is quite strong, because of the relativistic stabilisation of the 6s orbital and the decreasing bond energy as the atoms increase in size so that the amount of energy released in forming two more bonds is not worth the high ionisation energies of the 6s electrons. It displays the +1 oxidation state that all the known alkali metals display, and thallium compounds with thallium in its +1 oxidation state closely resemble the corresponding potassium or silver compounds stoichiometrically due to the similar ionic radii of the Tl+ (164 pm), K+ (152 pm) and Ag+ (129 pm) ions. It was sometimes considered an alkali metal in continental Europe (but not in England) in the years immediately following its discovery, and was placed just after caesium as the sixth alkali metal in Dmitri Mendeleev's 1869 periodic table and Julius Lothar Meyer's 1868 periodic table. Mendeleev's 1871 periodic table and Meyer's 1870 periodic table put thallium in its current position in the boron group and left the space below caesium blank. However, thallium also displays the oxidation state +3, which no known alkali metal displays (although ununennium, the undiscovered seventh alkali metal, is predicted to possibly display the +3 oxidation state). The sixth alkali metal is now considered to be francium.
=== New Zealand === Although absinthe is not prohibited at the national level, some local authorities have banned it. The latest is Mataura in Southland. The ban came in August 2008 after several issues of misuse drew public and police attention. One incident resulted in breathing difficulties and hospitalising of a 17-year-old for alcohol poisoning. The particular brand of absinthe that caused these effects was bottled at 89% ABV.
Sources: en.wikipedia.org
Progesterone is produced from cholesterol with pregnenolone as a metabolic intermediate. In the first step in the steroidogenic pathway, cholesterol is converted into pregnenolone, which serves as the precursor to the progestogens progesterone and 17α-hydroxyprogesterone. These progestogens, along with another steroid, 17α-hydroxypregnenolone, are the precursors of all other endogenous steroids, including the androgens, estrogens, glucocorticoids, mineralocorticoids, and neurosteroids. Thus, many tissues producing steroids, including the adrenal glands, testes, and ovaries, produce progestogens. In some tissues, the enzymes required for the final product are not all located in a single cell. For example, in ovarian follicles, cholesterol is converted to androstenedione, an androgen, in the theca cells, which is then further converted into estrogen in the granulosa cells. Fetal adrenal glands also produce pregnenolone in some species, which is converted into progesterone and estrogens by the placenta (see below). In the human, the fetal adrenals produce dehydroepiandrosterone (DHEA) via the pregnenolone pathway.
Additionally, a cartel battle for control of the Amazon region has intensified between rival gangs including the CV, seeking access to the valuable trafficking routes in the Colombia-Brazil-Peru tri-border region, the CV, PCC, Familia do Norte, and Colombian militia groups including the Border Command and the Carolina Ramirez Front have violently fought, contributing to a significant uptick in regional fatalities. In 2023, sources consistently reported frequent violent clashes between the CV and the PCC as well as other rival gang groups. The worst PCC linked-proxy war was between Guardiões do Estado and Comando Vermelho, with more than 10.000 killed in gang battles in Ceará state. During this proxy war, GDE displaced hundreds of civilians, burned houses, buses, perpetred massacres and mostly homicides in the state of Ceará, the most notable being the Cajazeiras massacre with 14 killed and 9 injured.
In the 2013 gubernatorial election, Republican Chris Christie received 64.3% of the vote (1,412 cast), ahead of Democrat Barbara Buono with 34.9% (766 votes), and other candidates with 0.9% (19 votes), among the 2,259 ballots cast by the borough's 4,949 registered voters (62 ballots were spoiled), for a turnout of 45.6%. In the 2009 gubernatorial election, Republican Chris Christie received 1,213 votes (49.5% vs. 45.8% countywide), ahead of Democrat Jon Corzine with 1,106 votes (45.2% vs. 48.0%), Independent Chris Daggett with 99 votes (4.0% vs. 4.7%) and other candidates with 8 votes (0.3% vs. 0.5%), among the 2,449 ballots cast by the borough's 4,975 registered voters, yielding a 49.2% turnout (vs. 50.0% in the county).
Arboreal animals frequently have elongated limbs that help them cross gaps, reach fruit or other resources, test the firmness of support ahead and, in some cases, to brachiate (swing between trees). Many arboreal species, such as tree porcupines, silky anteaters, spider monkeys, and possums, use prehensile tails to grasp branches. In the spider monkey, the tip of the tail has either a bare patch or adhesive pad, which provides increased friction. Claws can be used to interact with rough substrates and reorient the direction of forces the animal applies. This is what allows squirrels to climb tree trunks that are so large to be essentially flat from the perspective of such a small animal. However, claws can interfere with an animal's ability to grasp very small branches, as they may wrap too far around and prick the animal's own paw. Frictional gripping is used by primates, relying upon hairless fingertips. Squeezing the branch between the fingertips generates frictional force that holds the animal's hand to the branch. However, this type of grip depends upon the angle of the frictional force, thus upon the diameter of the branch, with larger branches resulting in reduced gripping ability. To control descent, especially down large diameter branches, some arboreal animals such as squirrels have evolved highly mobile ankle joints that permit rotating the foot into a 'reversed' posture. This allows the claws to hook into the rough surface of the bark, opposing the force of gravity.
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.