This is a working overview of reversed-phase HPLC, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-17. Anything still debated is marked as such rather than presented as settled.
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。
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
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.
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.
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.
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.
Subject of research: synthesis of organophosphorous and organoelement compounds, study of their spatial and electronic structure, intramolecular electronic interactions, reaction capacity and mechanism of reactions. Arkady N. Pudovik corresponding member of Russian Academy of Science worked at this department since its opening (1948) until his death (February 2006) he was the founder of the department of High Molecular and Organoelement Compounds and held the position of Head of department until 1987. Current head of the Department – Corresponding Member of the Academy of Sciences of the Republic of Tatarstan, Professor Vladimir I. Galkin, doctor of Science in chemistry. The Department conducts research in the following fields:
The fragment molecular orbital method (FMO) was developed by Kazuo Kitaura and coworkers in 1999. FMO is deeply interconnected with the energy decomposition analysis (EDA) by Kazuo Kitaura and Keiji Morokuma, developed in 1976. The main use of FMO is to compute very large molecular systems by dividing them into fragments and performing ab initio or density functional quantum-mechanical calculations of fragments and their dimers, whereby the Coulomb field from the whole system is included. The latter feature allows fragment calculations without using caps. The mutually consistent field (MCF) method had introduced the idea of self-consistent fragment calculations in their embedding potential, which was later used with some modifications in various methods including FMO. There had been other methods related to FMO including the incremental correlation method by H. Stoll (1992). Later, other methods closely related to FMO were proposed including the kernel energy method of L. Huang and the electrostatically embedded many-body expansion by E. Dahlke, S. Hirata and later M. Kamiya suggested approaches also very closely related to FMO. Effective fragment molecular orbital (EFMO) method combines some features of the effective fragment potentials (EFP) and FMO. A detailed perspective on the fragment-based method development can be found in a review.
The secretin-cholecystokinin test (aka Secretin-CCK test, Secretin-Pancreozymin test) is a combination of the secretin test and the cholecystokinin test and is used to assess the function of both the pancreas and gall bladder. Cholecystokinin (CKK) is a peptide hormone secreted by I-cells in the intestinal mucosa. It stimulates the secretion of pancreatic fluid into the duodenum through the sphincter of oddi. This fluid is rich in pancreatic enzymes amylase, trypsin, and lipase. It also promotes contraction and relaxation of the gallbladder. Secretin is a peptide hormone that stimulates the secretion of both pancreatic fluid and bicarbonate. The Secretin-cholecystokinin test is considered the gold standard test of pancreatic exocrine function. It is now rarely used in adults in favour of non-invasive tests, though it is still used in some cases in infants with pancreatic insufficiency to distinguish between cystic fibrosis and Schwachman-Diamond syndrome.
Naturally occurring actinium is principally composed of two radioactive isotopes; 227Ac (from the radioactive family of 235U) and 228Ac (a granddaughter of 232Th). 227Ac decays mainly as a beta emitter with a very small energy, but in 1.38% of cases it emits an alpha particle, so it can readily be identified through alpha spectrometry. Thirty-three radioisotopes have been identified, the most stable being 227Ac with a half-life of 21.772 years, 225Ac with a half-life of 10.0 days and 226Ac with a half-life of 29.37 hours. All remaining radioactive isotopes have half-lives that are less than 10 hours, and the majority of them have half-lives shorter than one minute. The shortest-lived known isotope of actinium is 217Ac (half-life of 69 nanoseconds) which decays through alpha decay. Actinium also has two known meta states. The most significant isotopes for chemistry are 225Ac, 227Ac, and 228Ac. Purified 227Ac comes into equilibrium with its decay products after about a half-year. It decays according to its 21.772-year half-life, emitting mostly beta (98.62%) and some alpha particles (1.38%); the successive decay products are part of the actinium series. Owing to the low available amounts, low energy of its beta particles (maximum 44.8 keV) and low intensity of alpha radiation, 227Ac is difficult to detect directly by its emission, and it is therefore traced via its decay products. The isotopes of actinium range in atomic weight from 203 Da (203Ac) to 236 Da (236Ac).
Thebaine (paramorphine), also known as codeine methyl enol ether, is an opiate alkaloid, its name coming from the Greek Θῆβαι, Thēbai (Thebes), an ancient city in Upper Egypt. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects. At high doses, it causes convulsions similar to strychnine poisoning. The synthetic enantiomer (+)-thebaine does show analgesic effects apparently mediated through opioid receptors, unlike the inactive natural enantiomer (−)-thebaine. While thebaine is not used therapeutically, it is the main alkaloid extracted from Papaver bracteatum (Iranian opium / Persian poppy) and can be converted industrially into a variety of compounds that do have medicinal value.
Sources: en.wikipedia.org
The University of Galway (Irish: Ollscoil na Gaillimhe) is a public research university located in the city of Galway, Ireland. It was founded in 1845 as Queen's College, Galway. It was known as "University College, Galway" from 1908 to 1997 and as "National University of Ireland, Galway" (NUI Galway) from 1997 to 2022. In September 2022, the university changed its name to "University of Galway". It is also a member of the Coimbra Group, a network of 42 long-established European universities.
C57BL/6 mice have a dark brown, nearly black coat. They are more sensitive to noise and odours and are more likely to bite than the more docile laboratory strains such as BALB/c. Group-housed C57BL/6 mice (and other strains) display barbering behaviour, which used to be seen as a sign of dominance. However, it is now known that this is more of a stereotypical behaviour triggered by stress, comparable to trichotillomania in humans or feather plucking in parrots. Mice that have been barbered extensively can have large bald patches on their bodies, commonly around the head, snout, and shoulders, although barbering may appear anywhere on the body. Also self-barbering can occur. Both hair and vibrissae may be removed. Barbering is more frequently seen in female mice; male mice are more likely to display dominance through fighting. C57BL/6 has several unusual characteristics which make it useful for some research studies but inappropriate for others: It is unusually sensitive to pain and to cold, and analgesic medications are less effective in this strain. Unlike most laboratory mouse strains, the C57BL/6 drinks alcoholic beverages voluntarily. It is more susceptible than average to morphine addiction, atherosclerosis, and age-related hearing loss. When compared directly to BALB/c mice, C57BL/6 mice also express both a robust response to social rewards and empathy.
The first and innermost major ring, Bulvarnoye Koltso (Boulevard Ring), was built on the former location of the 16th-century city wall around Bely Gorod (White Town). The Bulvarnoye Koltso is technically not a ring: it forms an incomplete circle—a horseshoe-shaped arc beginning at the Cathedral of Christ the Saviour and ending at the Yauza River. The second primary ring, located outside the Boulevard Ring, is the Sadovoye Koltso (Garden Ring). Like the Boulevard Ring, the Garden Ring follows the path of a 16th-century wall that previously encompassed part of Moscow. The Third Ring Road was completed in 2003 as a high-speed freeway. The Fourth Transport Ring—another freeway—was planned, but it was canceled in 2011. A system of chordal highways will be constructed instead. In addition to these concentric ring roads, line 5 of the Moscow Metro is circular (hence its name Koltsevaya Liniya [lit. 'ring line']). It is located between the Garden Ring and the Third Transport Ring. Two overlapping lines of the Moscow Metro form "two hearts":t
glutathione + a lactate The catalysis of S-lactoylglutathione hydrolysis by glutathione thiolesterase has been noted in Saccharomyces cerevisiae. Additionally, human red blood cells have been found to contain at least four separate glutathione thiol esterases. The enzymes found supported the potential substrate activity of S-lactoylglutathione and S-propionylglutathione.
Sources: en.wikipedia.org
=== Management === The management of uterine prolapse may be conservative or surgical, depending on factors such as personal preference, symptom severity, and extent of prolapse. Additionally, management of existing medical conditions that can contribute to prolapse, such as chronic lung conditions or obesity, are important to prevent progression of uterine prolapse and reduce symptom burden.
== See also == The first man who was called a sans-culotte was the poet Nicolas Joseph Laurent Gilbert; also Robespierre and Pétion de Villeneuve were described as sans-culottes before the word came in vogue. Croppy Descamisado François Chabot Lazzaroni (Naples) Lumpenproletariat Pétroleuses
Matthew later finds James sitting on the bridge and in a moment of recklessness James drinks from his flask, and loses consciousness due to exhaustion. The next morning when he wakes up, he finds the hurt gone, and feels oddly light. Cordelia meanwhile had accompanied Anna to the infirmary and seen her put her guard down and sob for Ariadne. Will and Tessa have gone with the Silent Brothers to transport Tatiana and the other remaining wounded Shadowhunters to the Silent City. Grace will be staying with the Bridgestocks near the City to be close to her mother. Cordelia receives a letter from Charlotte, answering her inquiries about her father. He’s actually already been questioned with the Mortal Sword, which Cordelia was sure would clear his name as it requires the holder to speak only truth. Unfortunately, the demon attack has been erased from his memory, so he cannot clear his name with the sword. Christopher arrives with the results and the group discovers that the shards of wood were pieces of a Pyxis. James informs them that the inscription were written in Old Persian and they realize that the demon was in fact a Mandikhor demon, which can produce smaller demons. They form a plan to capture the demon but for that they would need a Pyxis. Cordelia recalls seeing one at Hypatia's salon and they decide to approach Anna for aid. James escorts Cordelia home and Sona presumes that they both were getting closer than before and James had marital intentions, to which Cordelia replies in the negative.
(one-letter sequence: NDECELCVNVACTGCL). Plecanatide is nearly structurally identical to human uroguanylin, apart from the substitution of Asp3 with Glu3. Disulfide bonds exist between Cys4 and Cys12, as well as Cys7 and Cys15. Plecanatide has two important motifs. The first being the acidic residues Asp2 and Glu3 which modulate the affinity for its receptor in response to environmental pH. Simulations predict the optimal activity of Plecanatide to occur at pH 5, making it suitable for targeting cells within the proximal intestine, which has a pH of between 5 and 6. The second is the ACTGC motif (residues Ala11 to Cys15) which is the region responsible for its binding to the receptor, guanylate cyclase-C.
=== Pharmacokinetics === The bioavailability of tianeptine is approximately 99%. Its plasma protein binding is about 95%. The metabolism of tianeptine is hepatic, via β-oxidation. CYP enzymes are not involved, which limits the potential for drug-drug interactions. Maximal concentration is reached in about an hour and the elimination half-life is 2.5 to 3 hours. The elimination half-life has been found to be increased to 4 to 9 hours in the elderly. Tianeptine is usually packaged as a sodium salt but can also be found as tianeptine sulfate, a slower-releasing formulation patented by Janssen in 2012. In 2022 Tonix Pharmaceuticals received permission from the US FDA to conduct phase II clinical trials on tianeptine hemioxalate extended-release tablets designed for once-daily use. The project was discontinued in late 2023 because of disappointing results in clinical trials. Tianeptine has two active metabolites, MC5 (a pentanoic acid derivative of the parent compound) and MC3 (a propionic acid derivative). MC5 has a longer elimination half-life of approximately 7.6 hours, and takes about a week to reach steady-state concentration under daily-dosing. MC5 is a mu-opioid agonist but not delta-opioid agonist, with EC50 at the mu-opioid receptor of 0.545 μM (vs 0.194 μM for tianeptine). MC3 is a very weak mu-opioid agonist, with an EC50 of 16 μM. Tianeptine is excreted 65% in the urine and 15% in feces.
Sources: en.wikipedia.org
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。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.