Everything below concerns RP-HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
Identity and purity are normally confirmed by reversed-phase high-performance liquid chromatography and mass spectrometry. The expected mass for the acetylated 28-residue peptide is close to 3108 daltons, and a mass shift indicates a modification or truncation. Peptide mapping after enzymatic digestion can resolve sequence-level questions. Counter-ion content, water content, and residual solvents are separate quality attributes that a certificate of analysis may or may not report. Aggregation is monitored by size-exclusion chromatography when relevant.
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。
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Soluble in water | Also soluble in aqueous buffers |
| Storage temperature | -20 °C or below | Desiccated, protected from light |
| Typical analytical method | RP-HPLC with mass spectrometry | Purity and identity |
| Common synonyms | Thymalfasin, T alpha 1 | Sequence identical to natural fragment |
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。
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
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.
In Matrix-assisted inlet ionization (MAII), a matrix which can be a solvent is used at ambient temperature with the analyte of interest as a mixture. The matrix/analyte mixture is inserted into the heated inlet tube through tapping the mixture at the opening end of the tube. For the highly charged ions of the analyte to be produced from ionization, desolvation of the matrix molecules needs to occur. Matrices that can be used include: 2,5-dihydroxybenzoic acid, 2,5-dihydroxyacetophenone, 2-aminobenzyl alcohol, anthranilic acid, and 2-hydroxyacetophenone.
In chemistry, a zwitterion ( TSVIT-ər-EYE-on; from German Zwitter [ˈtsvɪtɐ] 'hermaphrodite' + Ion), also called an inner salt or dipolar ion is a molecule that contains an equal number of positively and negatively charged functional groups. (1,2-dipolar compounds, such as ylides, are sometimes excluded from the definition.) Some zwitterions, such as amino acid zwitterions, are in chemical equilibrium with an uncharged "parent" molecule. Betaines are zwitterions that cannot isomerize to an all-neutral form, such as when the positive charge is located on a quaternary ammonium group. Similarly, a molecule containing a phosphonium group and a carboxylate group cannot isomerize. Because tautomers are different compounds, they have distinct structures. By detecting each, the equilibrium between the zwitterion and its uncharged tautomer can be assessed.
On March 21, 1991, a Royal Saudi Air Force C-130H crashed in heavy smoke due to the Kuwaiti oil fires on approach to Ras Mishab Airport, Saudi Arabia. 92 Senegalese soldiers and 6 Saudi crew members were killed, the largest accident among Coalition forces. The smoke screening was also used by Iraqi anti-armor forces to a successful extent in the Battle of Phase Line Bullet, having aided in achieving the element of surprise against advancing Bradley IFVs, along with increasing the general fog of war. The fires burned out of control because of the dangers of sending in firefighting crews during the war. Land mines had been placed in areas around the oil wells and military demining was necessary before the fires could be put out. Around 5 million barrels (790,000 m3) of oil were lost each day. Eventually, privately contracted crews extinguished the fires, at a total cost of US$1.5 billion to Kuwait. By that time, however, the fires had burned for approximately ten months, causing widespread pollution. The fires have been linked with what was later deemed Gulf War syndrome, a chronic disorder afflicting military veterans and civilian workers that include fatigue, muscle pain, and cognitive problems; however, studies have indicated that the firemen who capped the wells did not report any of the symptoms that the soldiers experienced. The cause of Gulf War syndrome has since been ascribed to Sarin nerve agent.
Sources: en.wikipedia.org
==== General indications ==== Doxycycline is a broad-spectrum antibiotic that is employed in the treatment of numerous bacterial infections. The drug is effective against bacteria such as Moraxella catarrhalis (a cause of respiratory tract infections), Brucella melitensis (a cause of brucellosis), Chlamydia pneumoniae (a cause of atypical pneumonia), and Mycoplasma pneumoniae (a cause of pneumonia). Additionally, doxycycline is used in the prevention and treatment of serious conditions like anthrax, leptospirosis, bubonic plague, and Lyme disease. However, some bacteria have developed resistance to doxycycline, including Haemophilus species, Mycoplasma hominis, and Pseudomonas aeruginosa. Specifically, doxycycline is indicated for treatment of the following diseases:
== Further reading == Collins R (2017). "Lowering Restrictions on Performance Enhancing Drugs in Elite Sports". Inquiries Journal. 9 (3). Retrieved 7 July 2017. Franke WW, Berendonk B (July 1997). "Hormonal doping and androgenization of athletes: a secret program of the German Democratic Republic government". Clinical Chemistry. 43 (7): 1262–79. doi:10.1093/clinchem/43.7.1262. PMID 9216474. Mottram, David (2005); Drugs in Sport, Routledge. ISBN 978-0-415-37564-1. Murray, Thomas H. (2008); "Sports Enhancement", in From Birth to Death and Bench to Clinic: The Hastings Center Bioethics Briefing Book for Journalists, Policymakers, and Campaigns. Pope J, Harrison G, Wood RI, Rogol A, Nyberg F, Bowers L, Bhasin S (2014). "Adverse health consequences of performance-enhancing drugs: An endocrine society scientific statement". Endocrine Reviews. 35 (3): 341–375. doi:10.1210/er.2013-1058. PMC 4026349. PMID 24423981. Waddington and Smith (2008); An Introduction to Drugs in Sport, Routledge. ISBN 978-0-415-43125-5. Collins R (2017). "Lowering Restrictions on Performance Enhancing Drugs in Elite Sports". Inquiries Journal. 9 (3). Retrieved 7 July 2017. Toby M (2024). The History of Performance-Enhancing Drugs In Thoroughbred Racing. University of Kentucky Press. ISBN 9780813197975.
== Molecular clocks == Molecular clocks can be used to estimate the amount of time since divergence of two species and for placing evolutionary events in time. Pauling and Zuckerkandl, proposed the idea of the molecular clock in 1962 based on the observation that the random mutation process occurs at an approximate constant rate. Individual proteins were shown to have linear rates of amino acid changes over evolutionary time. Despite controversy from some biologists arguing that morphological evolution would not proceed at a constant rate, many amino acid changes were shown to accumulate in a constant fashion. Kimura and Ohta explained these rates as part of the framework of the neutral theory. These mutations were reasoned to be neutral as positive selection should be rare and deleterious mutations should be eliminated quickly from a population. By this reasoning, the accumulation of these neutral mutations should only be influenced by the mutation rate. Therefore, the neutral mutation rate in individual organisms should match the molecular evolution rate in species over evolutionary time. The neutral mutation rate is affected by the amount of neutral sites in a protein or DNA sequence versus the amount of mutation in sites that are functionally constrained. By quantifying these neutral mutations in protein and/or DNA and comparing them between species or other groups of interest, rates of divergence can be determined.
Angered by the snub, Gaddafi plotted with Abu Nidal to assassinate Hassan in 1987, but the plot was aborted. In 1981, the new US president, Ronald Reagan, pursued a hardline approach to Libya, viewing it as a puppet regime of the Soviet Union. Gaddafi played up his commercial relationship with the Soviets, revisiting Moscow in 1981 and 1985, and threatening to join the Warsaw Pact. The Soviets were nevertheless cautious of Gaddafi, seeing him as an unpredictable extremist. In August 1981, the US staged military exercises in the Gulf of Sirte – an area which Libya claimed. The US shot down two Libyan Su-22 planes which were on an intercept course. Closing down Libya's embassy in Washington, Reagan advised US companies operating in Libya to reduce Americans stationed there. In December 1981, the White House claimed Gaddafi had dispatched a hit squad to assassinate Reagan, allegedly led by Carlos the Jackal, who had been living in Libya under Gaddafi's protection after the 1975 OPEC siege. Secretary of State Alexander Haig, Defense Secretary Caspar Weinberger, Counselor to the President Edwin Meese, chief of staff James Baker, and deputy chief of staff Michael Deaver were considered potential targets and given special security. US ambassador to Italy Maxwell M. Rabb, who was Jewish, was urgently recalled due to threats against his life. Gaddafi denied the allegations. Gaddafi was accused of having ties to the Lebanese Armed Revolutionary Factions, which had murdered US military attaché Charles R. Ray and Israeli diplomat Yacov Barsimantov in Paris.
Sources: en.wikipedia.org
=== Flow: Sverdrup === One sverdrup (Sv) is equal to 1,000,000 cubic metres per second (264,000,000 USgal/s). It is used almost exclusively in oceanography to measure the volumetric rate of transport of ocean currents.
A variety of medical and psychological conditions have been misdiagnosed as anorexia nervosa; in some cases the correct diagnosis was not made for more than ten years. The distinction between binge purging anorexia, bulimia nervosa and Other Specified Feeding or Eating Disorders (OSFED) is often difficult for non-specialist clinicians. A main factor differentiating binge-purge anorexia from bulimia is the gap in physical weight. Patients with bulimia nervosa are ordinarily at a healthy weight, or slightly overweight. Patients with binge-purge anorexia are commonly underweight. Moreover, patients with the binge-purging subtype may be significantly underweight and typically do not binge-eat large amounts of food. In contrast, those with bulimia nervosa tend to binge large amounts of food. It is not unusual for patients with an eating disorder to "move through" various diagnoses as their behavior and beliefs change over time.
Lex Politica also represented the non-profit arm in the US of Victor Orban's Danube Institute. Gober was also involved in the 2025 redistricting process. Republican mapmaker Kincaid testified that the Republican National Committee retained Gober to represent the Texas Republican congressional delegation and that Gober conveyed the delegation's requests to him during the map-drawing process. Gober's congressional campaign subsequently listed his redistricting work among his accomplishments, stating that he had helped deliver a redistricting plan that strengthened the Republican majority and describing the result as having "Secured Five New Republican Seats." Gober won the Republican nomination for Texas’ redrawn 10th Congressional District with 51.2 percent of the vote, narrowly avoiding a runoff. Gober is running on a platform of strict border security, “America First” economic policies, and the “weaponization of government” against conservative causes. The incumbent is Republican Michael McCaul, who was re-elected in 2024 with 63.6% of the vote. McCaul is not seeking reelection in the redrawn district, which gave 60.5% of the vote to Donald Trump and 58.4% to Ted Cruz in 2024.
The heart is an organ located in the thoracic cavity between the lungs and slightly to the left. It is surrounded by the pericardium, which holds it in place in the mediastinum and serves to protect it from blunt trauma, infection and help lubricate the movement of the heart via pericardial fluid. The heart works by pumping blood around the body allowing oxygen, nutrients, waste, hormones and white blood cells to be transported.
The Kizil Caves were first discovered and explored in 1902–1904 by the Ōtani expedition, a Japanese expedition under Tesshin Watanabe (渡辺哲信) and Kenyu Hori (堀賢雄), funded by Count Otani, but the expedition left hurriedly after four months of exploration in the area of Kucha, following a local earthquake. The Kizil caves were then explored by Albert Grünwedel, head of the Third German Turfan Expedition (December 1905 – July 6, 1907). Albert von Le Coq was also part of the third German expedition and was under the direction of Albert Grünwedel, but only remained until June 1906, when he had to leave for British India due to a heavy illness. The caves were photographed, drawings were made, and large portions of the murals were removed and sent to Germany. Grünwedel removed a great number of paintings, but was careful to make records before doing so in order to retain their archaeological value, and to photograph or draw them before cutting them out, out of fear that they could be destroyed upon removal or during transport. He used a canvas to take quite precise records of the paintings. For example, Grünwedel recounts how he discovered a very interesting mural with warriors in the Cave of the Painters (207). Intending to remove it, he first made a precise drawing. But once the drawing was made, the mural disintegrated upon removal and was lost, except for a few fragments still in-situ. Altogether, the Third German Expedition still removed many paintings, and shipped almost 120 crates of murals to Berlin.
Sources: en.wikipedia.org
Lyophilized powder is normally kept at minus twenty degrees Celsius or below, in a sealed container, desiccated and away from light. Reconstituted solutions are less stable and are usually refrigerated and used quickly. Repeated temperature cycling should be avoided.
Mass spectrometry gives the molecular mass, which is compared with the calculated value. Reversed-phase liquid chromatography shows purity and the presence of related impurities. Peptide mapping can verify the amino acid sequence when a higher level of detail is needed.
It reports the tests the supplier performed, which may vary between laboratories and lots. Methods and acceptance criteria are not standardised across suppliers. Buyers often request the actual chromatograms and spectra rather than a summary statement.
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。