The short version of 细胞因子 fits in a sentence. The long version — which is the one that helps — is below.
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Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
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。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Thymosin alpha 1 is a 28-amino-acid peptide first isolated from thymosin fraction 5, a bovine thymic extract. Its sequence begins with an acetylated serine residue and carries a high proportion of acidic residues, so the molecule has a net negative charge near neutral pH. Despite the shared name, it is unrelated in sequence to the thymosin beta family. Synthetic material prepared by solid-phase peptide synthesis is identical in sequence to the natural peptide.
Several names appear in the literature for this peptide, including thymalfasin and the abbreviation T-alpha-1. Naming conventions differ among research articles, regulatory documents, and supplier catalogs, which complicates literature searches. Both synthetic and recombinant production routes yield a peptide with the same 28-residue sequence as the thymic isolate. Because the thymosin label also covers unrelated peptides, sources should be compared by sequence rather than by name alone.
The parties will proceed to close the transaction in which funds and title are exchanged. When a deal closes, post-closing processes may begin, including notifying tenants of an ownership change, transferring vendor relationships, and handing over relevant information to the asset management team.
=== Wet === Wet or canned dog food usually is packaged in a solid or soft-sided container. Wet food contains roughly 60–78% water, which is significantly higher in moisture than dry or semi-moist food. Canned food is commercially sterile (cooked during canning); other wet foods may not be sterile. Sterilizing is done through the process of retorting, which involves steam sterilization at 121 degrees Celsius. A given wet food will often be higher in protein or fat compared to a similar dry food on a dry matter basis (a measure which ignores moisture); given the canned food's high moisture content. A larger amount of canned food must be fed in order to meet the dog's required needs. Grain gluten and other protein gels may be used in wet dog food to create artificial meaty chunks, which look like real meat. This food is usually used for old dogs or puppies.
=== February–April 1881 === On 14 February Carrington captured Ramokoatsi, which overlooked the main road to Morija. The following day, a force of 370 cavalry, 100 infantry, 50 native levies, and three artillery pieces under Brabant was sent out in search of a new camping ground. Upon crossing a spruit in the Ramibidikwa area, a CMR scout reported a massed formation of Basuto horsemen. Brabant ordered his soldiers to form a square; soon afterwards the Basuto commenced an attack on its front and two flanks. A combination of rifle and case shot fire kept the Basuto at bay in the center and the right flank. On the left, the Basuto managed to almost reach melee range before being likewise driven off. The artillery continued to fire on the retreating Basuto, who suffered 138 casualties in the engagement. One month later Clarke assumed personal command of the force, moving the camp to Ramibidikwa, 20 miles (32 km) from Morija. On 22 March, Carrington was heavily wounded in the vicinity of the new camp. By early April, Sprigg's conduct of the war was being heavily criticized in the Cape Parliament, whose opposition members were pushing for a vote of no confidence. Using Letsie as an intermediary, Robinson organized a meeting between Griffith and Lerotholi outside Maseru on 17 April. The two sides signed an armistice, although Lerotholi was unwilling to surrender his weapons, as the motion would be too unpopular among his tribesmen. On 29 April, Robinson announced the peace settlement, known as the Award.
salvage pathway Any metabolic pathway that utilizes compounds formed in catabolism for the anabolism or biosynthesis of new compounds, e.g. by recycling building block monomers such as free purine and pyrimidine bases to make new nucleotides.
Sources: en.wikipedia.org
The Don Cossack Host (Russian: Всевеликое Войско Донское, Vsevelikoye Voysko Donskoye) was either an independent or an autonomous democratic republic, located in present-day Southern Russia. It existed from the end of the 16th century until the early 20th century. There are two main theories of the origin of the Don Cossacks. Most respected historians support the migration theory, according to which they were Slavic colonists. The various autochthonous theories popular among the Cossacks themselves do not find confirmation in genetic studies. The gene pool comprises mainly the East Slavic component, with a significant Ukrainian contribution. There is no influence of the peoples of the Caucasus; and the steppe populations, represented by the Nogais, have only limited impact. The majority of Don Cossacks are either Eastern Orthodox or Christian Old Believers (старообрядцы). Prior to the Russian Civil War, there were numerous religious minorities, including Muslims, Subbotniks, and Jews.
==== Mate choice ==== Mate choice is seen in cuttlefish species, where females prefer some males over others, though characteristics of the preferred males are unknown. A hypothesis states that females reject males by olfactory cues rather than visual cues. Several cephalopod species are polyandrous – accepting and storing multiple male spermatophores, which has been identified by DNA fingerprinting. Females are no longer receptive to mating attempts when holding their eggs in their arms. Females can store sperm in two places (1) the buccal cavity where recently mated males place their spermatophores, and (2) the internal sperm-storage receptacles where sperm packages from previous males are stored. Spermatophore storage results in sperm competition; which states that the female controls which mate fertilizes the eggs. In order to reduce this sort of competition, males develop agonistic behaviors like mate guarding and flushing. The Hapalochlaena lunulata, or the blue-ringed octopus, readily mates with both males and females.
According to Sagan, the first civilization with which humanity would come into contact could be between "1.5 J" and "1.8 K"; a galactic supercivilization would be at the "3 Q" stage, while a federation of galaxies could be at the "4 Z" stage. The information and energy axes are not strictly interdependent, so even a level Z civilization would not have to be Kardashev Type III. Sagan believed that no civilization had yet reached level Z, speculating that so much unique information would exceed that of all the intelligent species in a galactic supercluster, and observing that the universe is not old enough to exchange information effectively over large distances. In 2017, the total amount of information generated on the internet was 26 zettabytes (with an estimated 120 zettabytes in 2023), equivalent to 0.73 R/S on Sagan's combined scale.
== Terminology == The term rheumatism stems from the Late Latin rheumatismus, ultimately from Greek ῥευματίζομαι "to suffer from a flux", with rheum meaning bodily fluids, i.e., any discharge of blood or bodily fluid. Before the 17th century, the joint pain which was thought to be caused by viscous humours seeping into the joints was always referred to as gout, a word adopted in Middle English from Old French gote "a drop; the gout, rheumatism". The English term rheumatism in the current sense has been in use since the late 17th century, as it was believed that chronic joint pain was caused by excessive flow of rheum which means bodily fluids into a joint.
=== Other workup methods === Penile nerves function Tests such as the bulbocavernosus reflex test are used to ascertain whether there is enough nerve sensation in the penis. The physician squeezes the glans (head) of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the latency between squeeze and contraction by observing the anal sphincter or by feeling it with a gloved finger in the anus. Nocturnal penile tumescence (NPT) It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge. A significant proportion of males who have no sexual dysfunction nonetheless do not have regular nocturnal erections. Penile biothesiometry This test uses electromagnetic vibration to evaluate sensitivity and nerve function in the glans and shaft of the penis. Dynamic infusion cavernosometry (DICC) Technique in which fluid is pumped into the penis at a known rate and pressure. It gives a measurement of the vascular pressure in the corpus cavernosum during an erection. Corpus cavernosometry Cavernosography measurement of the vascular pressure in the corpus cavernosum. Saline is infused under pressure into the corpus cavernosum with a butterfly needle, and the flow rate needed to maintain an erection indicates the degree of venous leakage.
Sources: en.wikipedia.org
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
The lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.