The short version of certificate of analysis fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-02. Anything still debated is marked as such rather than presented as settled.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
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 |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
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.
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.
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。
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
The lyophilized peptide is generally stable for extended periods when kept cold and dry. Once dissolved, aqueous solutions are less stable; hydrolysis, oxidation, and aggregation can degrade the material. Storage at -20 °C or lower slows these processes. Repeated freeze-thaw cycles are best avoided because they can promote aggregation. The exact shelf life depends on formulation, pH, and concentration, so stability studies are typically performed for each specific product.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
=== Czech Republic === After joining NATO, the Army of the Czech Republic developed a combat ration known as the BDP (Czech: Bojová Dávka Potravin). The BDP comes in two versions, type I and II, each holding two ready-to-eat main courses packed in large foil "cans" (beef roast with rice, pork goulash with potato, spicy risotto, pork with carrots and vegetables, etc.), a small plastic cup of lunch meat spread, cheese spread, hard bread, cookies, jam, instant coffee, tea bags, fruit-flavored multivitamin drink tablets, vitamin C enriched fruit drink powder, a chocolate bar, sugar, salt, chewing gum, wet napkins, paper towels, a plastic bag, and a menu and instruction sheet. A modified version of the BDP known as the KDP (Czech: Konzervovaná Dávka Potravin) is also used. This contains the same items as the BDP, but adds an aluminium cup, plastic utensils, a folding stove with fuel tablets and matches, and soap.
== References == Atmore, Anthony; Sanders, Peter (1971). "Sotho Arms and Ammunition in the Nineteenth Century". The Journal of African History. 12 (4): 535–544. doi:10.1017/S0021853700011130. ISSN 0021-8537. JSTOR 181011. S2CID 161528484. Bradlow, Edna (1970). "General Gordon in Basutoland". Historia. 15 (4): 223–242. ISSN 0018-229X. Retrieved 7 November 2021. Burman, Sandra (1981). Chiefdom Politics and Alien Law: Basutoland under Cape Rule 1871–1884. Palgrave Macmillan. ISBN 978-1-349-04639-3. Eldredge, Elizabeth (2007). Power in Colonial Africa: Conflict and Discourse in Lesotho, 1870–1960. The University of Wisconsin Press. ISBN 978-0-299-22370-0. Kotze, J. (2012). "Counter-Insurgency in the Cape Colony, 1872–1882". Scientia Militaria: South African Journal of Military Studies. 31 (2): 36–58. doi:10.5787/31-2-152. Retrieved 7 November 2021. Machobane, L. B.; Karschay, Stephan (1990). Government and Change in Lesotho, 1800–1966: A Study of Political Institutions. Palgrave Macmillan. ISBN 978-0-333-51570-9. Maliehe, Sean (2014). "An obscured narrative in the political economy of colonial commerce in Lesotho, 1870–1966". Historia. 59 (2): 28–45. hdl:2263/43121. ISSN 0018-229X. Retrieved 7 November 2021. Rosenberg, Scott; Weisfelder, Richard; Frisbie-Fulton, Michelle (2004). Historical Dictionary of Lesotho. The Scarecrow Press. ISBN 0-8108-4871-6. Tylden, G. (1936). "The Basutoland Rebellion of 1880–1881". Journal of the Society for Army Historical Research. 15 (58): 98–107. ISSN 0037-9700. JSTOR 44227993.
Learned optimism refers to development of one's potential for a sanguine outlook. Optimism is learned as personal efforts and abilities are linked to personally desired outcomes. In short, it is the belief one can influence the future in tangible and meaningful ways. Learned optimism contrasts with learned helplessness, which consists of a belief, or beliefs, one has no control over what occurs, and that something external dictates outcomes, e.g., success. Optimism is learned by consciously challenging negative self talk. This includes self talk on any event viewed as a personal failure that permanently affects all areas of the person's life. Intrapersonal, or internal, dialogues influence one's feelings. In fact, reports of happiness are correlated with the general ability to "rationalize or explain" social and economic inequalities. Hope is a powerful positive feeling, linked to a learned style of goal-directed thinking. Hope is fostered when a person utilizes both pathways thinking (the perceived capacity to find routes to desired goals) and agency thinking (the requisite motivations to use those routes). Author and journalist J.B. MacKinnon suggested the cognitive tool of "Vertical Agitation" can assist in avoiding helplessness (e.g., paralysis in the face of Earth's many problems). The concept stemmed from research on denial by sociologist Stanley Cohen. Cohen explained: in the face of massive problems people tend towards learned helplessness rather than confronting the dissonant facts of the matter.
Arthur Guinness started brewing ales in 1759 at the St. James's Gate Brewery, Dublin. On 31 December 1759, he signed a 9,000 year lease at £45 per annum for the unused brewery, and it would become one of the largest in the British Empire. Arthur Guinness started selling porter in 1778. The first Guinness beers to use the term "stout" were Single Stout and Double Stout in the 1840s. Throughout the bulk of its history, Guinness produced only three variations of a single beer type: porter or stout (single, double or extra) and foreign stout for export. "Stout" originally referred to a beer's strength, but eventually shifted meaning toward body and colour. Porter was also referred to as "plain", as mentioned in the famous refrain of Flann O'Brien's poem "The Workman's Friend": "A pint of plain is your only man." Already one of the top-three British and Irish brewers, Guinness's sales soared from 350,000 barrels in 1868 to 779,000 barrels in 1876. In October 1886, Guinness became a public company and was averaging sales of 1.138 million barrels a year. This was despite the brewery's refusal to either advertise or offer its beer at a discount. Even though Guinness owned no public houses, the company was valued at £6 million and shares were 20 times oversubscribed, with share prices rising to a 60 per cent premium on the first day of trading. The breweries pioneered several quality control efforts.
Sources: en.wikipedia.org
In an experiment described in the 2016 paper, rhesus macaques were infected with Ebola virus and treated with a combination of ansuvimab and another antibody isolated from the same subject, mAb100. Three doses of the combination were given once a day starting 1 day after the animals were infected. The control animal died and the treated animals all survived. In a second experiment described in the 2016 paper, rhesus macaques were infected with Ebola virus and only treated with ansuvimab. Three doses of ansuvimab were given once a day starting 1 day or 5 days after the animals were infected. The control animals died and the treated animals all survived. Unpublished data referred to in a publication of the 2018 Phase I clinical trial results of ansuvimab, reported that a single infusion of ansuvimab provided full protection of rhesus macaques and was the basis of the dosing used for human studies.
Because DNA collects mutations over time, which are then inherited, it contains historical information, and, by comparing DNA sequences, geneticists can infer the evolutionary history of organisms, their phylogeny. This field of phylogenetics is a powerful tool in evolutionary biology. If DNA sequences within a species are compared, population geneticists can learn the history of particular populations. This can be used in studies ranging from ecological genetics to anthropology. DNA as a storage device for information has enormous potential since it has much higher storage density compared to electronic devices. However, high costs, slow read and write times (memory latency), and insufficient reliability has prevented its practical use.
Niobium-95, with a half-life of 35 days, is initially present as a fission product. The only stable isotope of niobium has mass number 93, and fission products of mass 93 first decay to long-lived zirconium-93 (half-life 1.53 Ma). Niobium-95 will decay to molybdenum-95 which is stable.
16 June – Researchers report an fMRI study (31 May) that identifies circuitries and changes which may be crucial for consciousness in humans – or the loss and the recovery thereof in disorders of consciousness e.g. in coma patients. 17 June – Researchers report that a single gas-stove burner can raise the indoor concentrations of benzene, related to cancer risk, to more than that found in secondhand tobacco smoke. 19 June – Researchers review research on the substantial links between social isolation (HR ~1.32) and loneliness (HR ~1.14) and mortality. 21 June – The first successful transplant of a functional cryopreserved mammalian kidney is reported. The study demonstrates a "nanowarming" technique for vitrification for up-to-100 days preservation of transplant organs. 22 June – A study projects that by 2050, the worldwide number of adults with diabetes will more than double, from 529 million to over 1.3 billion. No country is expected to see a decline. 26 June Retatrutide, an experimental drug against obesity, is shown to achieve a more than 24% mean weight reduction in human adults during a Phase 2 trial. Astronomers detect, for the first time, methenium, CH3+ (and/or carbon cation, C+), basic ingredients of life as we know it, in interstellar space. 28 June Astronomers report the possible detection of a gravitational wave background (GWB) in the Universe. A study with controlling finds substantial links between reading for pleasure during childhood and later cognition.
=== Metabolic manipulation === Engineering of metabolic processes have been achieved through cell-free systems. Bujara et al., for example, were able to use glycolytic network extracts, consisting of enzymes from E. coli that produced dihydroxyacetone phosphate, to analyze in real-time the metabolite concentrations while altering enzyme levels, with the result of optimal production of dihydroxyacetone phosphate. Further, Calhoun and Swartz were able to use a glycolytic intermediate to fuel a cell-free system, enabling relatively inexpensive ATP generation compared to reagent usage in phosphoenolpyruvate reactions.
Sources: en.wikipedia.org
Most photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide and water using energy from light. However, not all organisms use carbon dioxide as a source of carbon atoms to carry out photosynthesis; photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon. In plants, algae, and cyanobacteria, photosynthesis releases oxygen. This oxygenic photosynthesis is by far the most common type of photosynthesis used by living organisms. Some shade-loving plants (sciophytes) produce such low levels of oxygen during photosynthesis that they use all of it themselves instead of releasing it to the atmosphere. Although there are some differences between oxygenic photosynthesis in plants, algae, and cyanobacteria, the overall process is quite similar in these organisms. There are also many varieties of anoxygenic photosynthesis, used mostly by bacteria, which consume carbon dioxide but do not release oxygen or which produce elemental sulfur instead of molecular oxygen. Carbon dioxide is converted into sugars in a process called carbon fixation; photosynthesis captures energy from sunlight to convert carbon dioxide into carbohydrates. Carbon fixation is an endothermic redox reaction. In general outline, photosynthesis is the opposite of cellular respiration: while photosynthesis is a process of reduction of carbon dioxide to carbohydrates, cellular respiration is the oxidation of carbohydrates or other nutrients to carbon dioxide.
Corticotropic releasing hormone (CRH): stimulates ACTH secretion Thyrotropin releasing hormone (TRH): stimulates TSH and prolactin secretion Growth hormone releasing hormone (GHRH): stimulates GH secretion Somatostatin: inhibits GH (and other hormone) secretion Gonadotropin releasing hormone (GnRH): stimulates FSH and LH secretion Prolactin releasing hormone (PRH): stimulates PRL secretion Prolactin inhibiting hormone (dopamine): inhibits PRL secretion These hypothalamic hormones are secreted in pulses. They act on specific membrane receptors. They are also glycoproteins. They stimulate:
=== Stratum corneum === The stratum corneum is typically 10–20 μm thick and consists of extracellular lipid-surrounded corneocytes. The lipophilic environment of the stratum corneum can serve as a reservoir for certain highly lipophilic molecules. Keratin found in the stratum corneum may provide great affinity with certain drugs. Both of these interactions can play a role in drug accumulation in the stratum corneum and the local drug action on skin disease.
=== CAT scans === CAT scans can be used to infer the 3D structure of a fossil egg's interior by compiling images taken of slices through the egg in small regular increments. Scientists have tried to use CAT scans to look for embryo fossils contained inside the egg without having to damage the egg itself by physically extracting them. However, as of Ken Carpenter's 1999 book on dinosaur eggs, Eggs, Nests, and Baby Dinosaurs, all alleged embryos discovered using this method were actually false alarms. Variations in the type of infilling mineral or cement binding the infilling sediment into rock sometimes resemble bones in CAT scan images. Sometimes eggshell fragments that fell back into the egg when it hatched have been mistaken for embryonic bones. The use of CAT scans to search for embryonic remains is actually conceptually flawed since embryonic bones have not yet mineralized. Since the infilling sediment is their only source of minerals they will be preserved at basically the same density and therefore have poor visibility in the scan. The validity of this issue has been confirmed by performing Cat scans on fossil eggs known to have embryos inside and noting their poor visibility in the scan images. The only truly reliable way to discover a dinosaur embryo is to cut the egg open or dissolve some of its eggshell away.
Sources: en.wikipedia.org
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.
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.