The short version of systematic review fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-05. Anything still debated is marked as such rather than presented as settled.
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 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈3,108 Da | Synthetic 28-residue peptide |
| Amino acid count | 28 | N-terminal serine carries an acetyl group |
| Appearance | White to off-white powder | Lyophilized solid |
| Water solubility | Freely soluble | Dissolves in aqueous buffer |
| Common synonyms | Thymalfasin; Tα1 | Thymalfasin is the international nonproprietary name |
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.
Reverse-phase high-performance liquid chromatography is the standard technique for assessing purity and concentration, because the peptide's hydrophobicity allows clean separation from related impurities. Mass spectrometry confirms molecular identity and detects sequence errors or truncations. Amino acid analysis and peptide mapping supply additional structural confirmation when required. Chromatographic purity values reported on certificates of analysis describe the proportion of the main peak and do not by themselves establish biological activity.
Like most short peptides, thymosin alpha-1 is susceptible to hydrolysis under strongly acidic or basic conditions and to oxidation when exposed to air over long periods. The acetylated amino terminus blocks one common degradation route, which contributes to the molecule's relative robustness in solution. Lyophilized material generally retains potency for extended periods when kept cold and dry. Once reconstituted, aqueous solutions are less stable and are typically used within a defined window rather than held indefinitely at ambient temperature.
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 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.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
== History == In 1980, the first percutaneous endoscopic gastrostomy (PEG) tube was reported, as an alternative to an open surgical placement of feeding tubes. The first cases of buried bumper syndrome were reported in 1988 and 1989. The term "buried bumper syndrome" was first used in 1990.
Glutamine-dependent NAD(+) synthetase is an enzyme that in humans is encoded by the NADSYN1 gene. Nicotinamide adenine dinucleotide (NAD) is a coenzyme in metabolic redox reactions, a precursor for several cell signaling molecules, and a substrate for protein posttranslational modifications. NAD synthetase (EC 6.3.5.1) catalyzes the final step in the biosynthesis of NAD from nicotinic acid adenine dinucleotide (NaAD).
The main minority ethnic groups of the former Commonwealth, including Ukrainians, Lithuanians, Belarusians and Jews, were getting involved in their own national movements and plans, which met with disapproval on the part of those Polish independence activists who counted on an eventual rebirth of the Commonwealth or the rise of a Commonwealth-inspired federal structure (a political movement referred to as Prometheism). Around the start of the 20th century, the Young Poland cultural movement, centered in Austrian Galicia, took advantage of a milieu conducive to liberal expression in that region and was the source of Poland's finest artistic and literary productions. In this same era, Marie Skłodowska Curie, a pioneer radiation scientist, performed her groundbreaking research in Paris.
== Fermentation == Unlike other tequila production steps, fermentation is largely outside the control of human beings. Fermentation is the conversion of sugars and carbohydrates to alcohol through yeast under anaerobic conditions, meaning that oxygen is not present during the process. Fermentation is also carried out in a non-aseptic environment, which increases the bacterial activity of tequila. The participation of microorganisms from the environment (yeasts and bacteria) makes fermentation a spontaneous process that gives rise to many byproducts that contribute to the flavor and aroma of tequila. During the fermentation process, inoculum is added to the batch to accelerate the rate of fermentation. When inoculum is added, fermentation can take approximately 20 hours to 3 days. If inoculum is not added, fermentation could take up to 7 days. The rate of fermentation is a key factor in the quality and flavor of tequila produced. Worts fermented slowly are best because the amount of organoleptic compounds produced is greater. The alcohol content at the end of fermentation is between 4% and 9%.
Sources: en.wikipedia.org
=== Ribosome stapling === The orthogonal ribosomes described above all focus on optimizing the 16S rRNA. Thus far, this optimized 16S rRNA was combined with natural large-subunits to form orthogonal ribosomes. If the 23S rRNA, the main RNA-component of the large ribosomal subunit, is to be optimized as well, it had to be assured, that there was no crosstalk in the assembly of orthogonal and natural ribosomes (see figure B). To ensure that optimized 23S rRNA would only form into ribosomes with the optimized 16S rRNA, the two rRNAs were combined into one transcript. By inserting the sequence for the 23S rRNA into a loop-region of the 16S rRNA sequence, both subunits still adopt functioning folds. Since the two rRNAs are linked and thus in constant proximity, they preferably bind each other, not other free floating ribosomal subunits.
Within hours of the invasion, Kuwait and US delegations requested a meeting of the UN Security Council, which passed Resolution 660, condemning the invasion and demanding a withdrawal of Iraqi troops. On 3 August 1990, the Arab League passed a resolution, which called for a solution from within the league, and warned against outside intervention. Iraq and Libya were the only Arab League states that opposed the resolution for Iraq to withdraw; the Palestine Liberation Organization (PLO) opposed it as well. Yemen and Jordan – a Western ally which bordered Iraq and relied on the country for economic support – opposed military intervention from non-Arab states. Separately, Sudan, also an Arab League member, aligned itself with Saddam. On 6 August, Resolution 661 placed economic sanctions on Iraq. Resolution 665 followed soon after, which authorized a naval blockade to enforce the sanctions. It said the "use of measures commensurate to the specific circumstances as may be necessary ... to halt all inward and outward maritime shipping in order to inspect and verify their cargoes and destinations and to ensure strict implementation of resolution 661." The US administration had at first been indecisive with an "undertone ... of resignation to the invasion and even adaptation to it as a fait accompli" until the UK's prime minister Thatcher played a powerful role, reminding the President that appeasement in the 1930s had led to war, that Saddam would have the whole Gulf at his mercy along with 65% of the world's oil supply, and famously urging Bush "not to go wobbly".
=== Inward rectifier potassium channels === Tertiapin binds specifically to different subunits of the inward rectifier potassium channel (Kir), namely GIRK1 (Kir 3.1), GIRK4 (Kir 3.4) and ROMK1 (Kir 1.1), inducing a dose-dependent block of the potassium current. It is thought that tertiapin binds to the Kir channel with its α-helix situated at the C-terminal of the peptide. This α-helix is plugged into the external end of the conduction pore, thereby blocking the channel. The N-terminal of the peptide sticks out of the extracellular side. Tertiapin has a high affinity for Kir channels with approximately Kd = 8 nM for GIRK1/4 channels and Kd = 2 nM for ROMK1 channels. In contrast to the voltage-gated K+ channels, Kir channels are more permeable to K+ during hyperpolarization than during depolarization. A voltage-dependent blockade by intracellular cations at voltages more positive than the K+ reversal potential is the mechanism underlying this feature. At more negative voltages the Kir channels are responsible for an inward K+ current. Therefore Kir channels contribute to the maintenance of the resting potential, the duration of the action potential and the neuronal excitability. GIRK1 and -4 are subunits of the muscarinic potassium channels (KACh) and have an important role in the slowing down of the heart rate in response to parasympathetic stimulation via acetylcholine. KAch channels activate during hyperpolarization, prolonging the cardiac action potential by inflow of potassium ions and reducing the frequency of action potential generation.
With the exception of Russia, the Polish nation has the distinction among other Slavic peoples of having enjoyed independence as a part of various entities for several centuries prior to the advent of Pan-Slavism. After 1795, Revolutionary and Napoleonic France had influenced many Poles who sought the reconstitution of their existing country—particularly since France was a mutual enemy of Austria, Prussia, and also Russia. Russia's Pan-Slavic rhetoric had alarmed the Poles. Pan-Slavism was not fully embraced among Poles after the early period. Poland did nevertheless express solidarity with those of its fellow Slavic nations that had suffered oppression and were seeking independence. While Pan-Slavism as an ideology was inimical to Austro-Hungarian interests, Poles instead embraced the wide autonomy within the state and assumed a loyalist position towards the Habsburgs. Within the Austro-Hungarian polity, they were able to develop their national culture and preserve the Polish language, both of which were under threat in both German and Russian Empires. A Pan-Slavic federation was proposed, but on the condition that the Russian Empire would be excluded from such an entity. After Poland regained its independence (from Germany, Austria and Russia) in 1918, no internal faction considered Pan-Slavism as a serious alternative, viewing Pan-Slavism as Russification. During Poland's communist era, the USSR used Pan-Slavism as a propaganda tool to justify its control over the country.
== Further reading == papuamide Ford, PW; Gustafson, KR; McKee, TC; Shigematsu, N; Maurizi, LK; Pannell, LK; Williams, DE; de Silva, ED; Lassota, P; Allen, TM; Van Soest, R; Andersen, RJ; Boyd, MR (1999). "Papuamides A-D, HIV-Inhibitory and Cytotoxic Depsipeptides from the Sponges Theonella mirabilis and Theonella swinhoei Collected in Papua New Guinea". J. Am. Chem. Soc. 121 (25): 5899–5909. Bibcode:1999JAChS.121.5899F. doi:10.1021/ja990582o. neamphamide A Oku, N; Gustafson, KR; Cartner, LK; Wilson, JA; Shigematsu, N; Hess, S; Pannell, LK; Boyd, MR; McMahon, JB (2004). "Neamphamide A. A new HIV-inhibitory depsipeptide from the Papua New Guinea marine sponge Neamphius huxleyi". J. Nat. Prod. 67 (8): 1407–11. Bibcode:2004JNAtP..67.1407O. doi:10.1021/np040003f. PMID 15332865. callipeltin A Zampella, A; D'Auria, MV; Paloma, LG; Casapullo, A; Minale, L; Debitus, C; Henin, Y (1996). "Callipeltin A, an Anti-HIV Cyclic Depsipeptide from the New Caledonian Lithistida Sponge Callipelta sp.". J. Am. Chem. Soc. 118 (26): 6202–9. Bibcode:1996JAChS.118.6202Z. doi:10.1021/ja954287p. mirabamides A-D Plaza, A; Gustchina, E; Baker, HL; Kelly, M; Bewley, CA (2007). "Mirabamides A-D. Depsipeptides from the sponge Siliquariaspongia mirabilis that inhibit HIV-1 fusion". J. Nat. Prod. 70 (11): 1753–60. Bibcode:2007JNAtP..70.1753P. doi:10.1021/np070306k. PMID 17963357.; Andjelic, CD; Planelles, V; Barrows, LR (2008). "Characterizing the Anti-HIV Activity of Papuamide A." Mar Drugs. 6 (4): 528–49. doi:10.3390/md20080027. PMC 2630844. PMID 19172193.
Sources: en.wikipedia.org
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.
It is usually described as an immunomodulatory peptide rather than a classic hormone. It acts on immune cells through receptor pathways. No single endocrine organ target defines its function.
Several countries, including Italy and China, allow it for specific indications. The FDA has not approved it as a drug in the United States. Availability depends on local regulation.
它促进未成熟T细胞分化并增强成熟T细胞的增殖与细胞因子分泌。这些作用有助于放大抗原特异性免疫应答。