This is a working overview of counter-ion, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-08. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Acetylated peptide | N-terminal acetyl group blocks aminopeptidase attack |
| Residue count | 28 amino acids | Matches the N-terminus of prothymosin alpha |
| Molecular mass | About 3,108 Da | Value for the free, unmodified peptide |
| Isoelectric point | Approximately 4.2 | Acidic; net negative charge at neutral pH |
| Encoding gene | PTMA | Human gene for the precursor protein |
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.
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.
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.
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。
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.
Routine handling calls for storage of the lyophilized powder at refrigerated temperatures, away from light, in a sealed container. Working solutions are often prepared in sterile water or buffer and kept cold between uses. Repeated freeze-thaw cycles are generally avoided because they can promote aggregation and loss of material. Laboratories usually record lot number, reconstitution date, and storage conditions so that any change in behavior can be traced to a specific preparation.
== Further reading == Aringer, Martin; Smolen, Josef S. (2007). "Mixed connective tissue disease: what is behind the curtain?". Best Practice & Research Clinical Rheumatology. 21 (6): 1037–1049. doi:10.1016/j.berh.2007.10.002. PMID 18068860. Gunnarsson, Ragnar; Hetlevik, Siri Opsahl; Lilleby, Vibke; Molberg, Øyvind (2016). "Mixed connective tissue disease". Best Practice & Research Clinical Rheumatology. 30 (1): 95–111. doi:10.1016/j.berh.2016.03.002. PMID 27421219.
In her ruling, she cited Jacobson v Massachusetts, a 1905 U.S. Supreme Court case that upheld the authority of U.S. states to compel people to get vaccinations. On March 25, 2020, Pritzker announced the extension of Illinois's tax filing deadline from April 15 to July 15. He also announced three new emergency assistance programs that allowed small businesses to access more than $90 million in aid. On April 23, 2020, Pritzker extended the stay-at-home order through May 29 with some modifications. Churches were prohibited from holding meetings that had more than 10 people in attendance. Some churches defied Pritzker, held meetings, and filed federal lawsuits. On May 1, 2020, Pritzker enacted a statewide mask mandate. On May 5, 2020, Pritzker announced his reopening plan, "Restore Illinois". The plan had five phases and split the state's 11 existing Emergency Medical Services Regions into four reopening regions. The regions could reopen independently of one another. All regions were then in Phase Two, which allowed retail curbside pickup and delivery along with outdoor activities such as golf, boating, and fishing. Phase Three would allow manufacturing, offices, retail, barbershops, and salons to reopen with capacity limits, along with gatherings of fewer than 10 people. In Phase 4, gatherings of up to 50 people were allowed, restaurants and bars could reopen, travel resumed, and child care and schools reopened under guidance from the IDPH. In Phase 5, the economy fully reopened.
== Criticism == Early skepticism toward lobotomy emerged in Soviet psychiatry. As reports on leucotomy and lobotomy surfaced in Soviet medical journals between 1936 and 1937, followed by more extensive reviews of Freeman and Watts's initial studies in 1939, Soviet reviewers expressed alarm at the procedure's severe complications and a reported 5 percent mortality rate, while also questioning its efficacy, observing that symptoms like fear, depression, and agitation often resolved spontaneously without necessitating such a dramatic procedure. These reviews suggested lobotomy should not be performed in the USSR. Later, by 1944, an author in the Journal of Nervous and Mental Disease remarked: "The history of prefrontal lobotomy has been brief and stormy. Its course has been dotted with both violent opposition and with slavish, unquestioning acceptance." Beginning in 1947 Swedish psychiatrist Snorre Wohlfahrt evaluated early trials, reporting that it is "distinctly hazardous to leucotomize schizophrenics" and that lobotomy was "still too imperfect to enable us, with its aid, to venture on a general offensive against chronic cases of mental disorder", stating further that "Psychosurgery has as yet failed to discover its precise indications and contraindications and the methods must unfortunately still be regarded as rather crude and hazardous in many respects." In 1948 Norbert Wiener, the author of Cybernetics: Or the Control and Communication in the Animal and the Machine, said: "Prefrontal lobotomy...
The legislative branch of government is represented nationally by the Congress, a bicameral institution comprising a 166-seat Chamber of Representatives and a 102-seat Senate. The Senate is elected nationally and the Chamber of Representatives is elected in electoral districts. Members of both houses are elected to serve four-year terms two months before the president, also by popular vote.
== Spray tanning == Spray tanning is a method of applying a dihydroxyacetone-based sunless tanning solution to the skin as a fine mist, producing a developed tan that lasts roughly five to ten days and fades as the outer skin layer is shed. Professional applications are offered at spas, salons and gymnasiums, either applied by hand with a hand-held airbrush sprayer ("airbrush tanning") or dispensed automatically in an enclosed spray booth that resembles a shower stall; consumer spray and aerosol products for home use are also widely sold. The U.S. Food and Drug Administration has approved DHA for external application but not for use around the eyes, on the lips or on mucous membranes, and it has not approved DHA for inhalation. The agency notes that when DHA is applied as an all-over spray or mist in a commercial booth, it may be difficult to avoid exposure in these unapproved ways. DHA and the slower-developing co-ingredient erythrulose have both been reported to cause contact dermatitis.
Sources: en.wikipedia.org
kinase Any of a class of enzymes which catalyze the transfer of phosphate groups from high-energy, phosphate-donating molecules such as ATP to one or more specific substrates, a process known as phosphorylation. The opposite process, known as dephosphorylation, is catalyzed by phosphatase enzymes.
==== Energy- and fragment-based methods ==== Ab initio- or de novo- protein modelling methods seek to build three-dimensional protein models "from scratch", i.e., based on physical principles rather than (directly) on previously solved structures. There are many possible procedures that either attempt to mimic protein folding or apply some stochastic method to search possible solutions (i.e., global optimization of a suitable energy function). These procedures tend to require vast computational resources, and have thus only been carried out for tiny proteins. To predict protein structure de novo for larger proteins will require better algorithms and larger computational resources like those afforded by either powerful supercomputers (such as Blue Gene or MDGRAPE-3) or distributed computing (such as Folding@home, the Human Proteome Folding Project and Rosetta@Home). Although these computational barriers are vast, the potential benefits of structural genomics (by predicted or experimental methods) make ab initio structure prediction an active research field. As of 2009, a 50-residue protein could be simulated atom-by-atom on a supercomputer for 1 millisecond. As of 2012, comparable stable-state sampling could be done on a standard desktop with a new graphics card and more sophisticated algorithms. A much larger simulation timescales can be achieved using coarse-grained modeling.
Electricity was originally understood to be a kind of fluid. This hydraulic analogy is still conceptually useful for understanding circuits. This analogy is also used to study the frequency response of fluid-mechanical networks using circuit tools, in which case the fluid network is termed a hydraulic circuit. Poiseuille's law corresponds to Ohm's law for electrical circuits, V = IR. Since the net force acting on the fluid is equal to ΔF = SΔp, where S = πr2, i.e. ΔF = πr2 ΔP, then from Poiseuille's law, it follows that
=== Cryopreserved red blood cells === To increase the availability of RBCs of rare blood types, red blood cells can be stored cryopreserved (frozen) instead of refrigerated. With a controlled, standardised freezing and thawing process, the red blood cells can be stored in frozen condition for up to 30 years. Also for cryopreservation, cell processors are frequently used for both the pre-freezing glycerolisation procedure and for washing away the glycerol after thawing of the red blood cells. Using an automated device allows for standardised processing to ensure optimal protection from ice crystal formation, which otherwise could damage the red blood cells. There are two general approaches for RBC cryopreservation, referred to as the high- and the low-glycerol method. Glycerol serves as cryoprotectant in both. The high-glycerol method uses 40% weight/volume glycerol, a slow freezing rate (1–3 °C per minute) and allows storage of the frozen red blood cells in common mechanical −60–80 °C freezers. The low-glycerol method is based on 20% weight/volume glycerol and demands plunge freezing in (−150 °C) liquid nitrogen. Because of the extreme storage temperature, the low-glycerol method is not compatible with the PVC tubes of blood bags. PVC tubes are essential for sterile docking; a technology which maintains a closed system after thawing and, thereby, allows a longer post-thawing shelf-life.
Sources: en.wikipedia.org
==== Propagation ==== Moringa can be propagated from seed or cuttings. Direct seeding is possible because the germination rate of M. oleifera is high. Moringa seeds can be germinated year-round in well-draining soil. Cuttings of 1 m (3.3 ft) length and at least 4 cm (1+1⁄2 in) diameter can be used for vegetative propagation.
=== Limitations === Removal limitations: If target ions are present in complex mixtures or at low concentrations, additional pre-treatment or post-treatment may be required. Regeneration requirements: Regeneration of ion exchange resins requires the use of chemicals and generates wastewater containing concentrated contaminants, which may require appropriate handling and disposal measures. Limited capacity: Ion exchange resins have finite capacities for adsorbing ions, and once saturated, they must be regenerated or replaced, which can limit their effectiveness in treating high-concentration or high-volume streams. Complexity: Ion exchange systems can be complex to design, operate, and maintain, requiring specialized knowledge and expertise.
== Biological Function == Acrosin is the major proteinase present in the acrosome of mature spermatozoa. It is stored in the acrosome in its precursor form, proacrosin. Upon stimulus, the acrosome releases its contents onto the zona pellucida. After this reaction occurs, the zymogen form of the protease is then processed into its active form, β-acrosin. The active enzyme then functions in the lysis of the zona pellucida, thus facilitating penetration of the sperm through the innermost glycoprotein layers of the ovum. The importance of acrosin in the acrosome reaction has been contested. It has been found through genetic knockout experiments that mouse spermatozoa lacking β-acrosin (the active protease) still have the ability to penetrate the zona pellucida. Thus, some argue for its role in assisting in the dispersal of acrosomal contents following the acrosome reaction, while others demonstrate evidence for its role as a secondary binding protein between the spermatozoa and zona pellucida. Under the secondary binding protein hypothesis, acrosin could serve a role in binding to molecules on the zona pellucida, tethering the spermatozoa to the egg. This "tethering" would ensure penetration due to the applied motile force of the spermatozoa. Acrosin regulation has been found to occur through protein C inhibitor (PCI). PCI is present in the male reproductive tract at 40x higher concentrations than in blood plasma. PCI has been demonstrated to inhibit the proteolytic activity of acrosin.
Sources: en.wikipedia.org
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.
The precursor, prothymosin alpha, is encoded by the PTMA gene in humans. The 28-residue peptide corresponds to the N-terminal segment released from that larger protein.
It is produced as a fragment of prothymosin alpha and is present in many tissues. Circulating concentrations are low, which makes routine measurement difficult.
Aliquots are typically frozen well below zero Celsius and thawed only once, since repeated cycles promote aggregation and loss. Dilution into a neutral buffer limits degradation during short working periods, and prolonged storage at room temperature is avoided.