This is a working overview of 免疫组织, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Physical form | Lyophilized powder | Reconstituted before use |
| Typical storage | 2-8 °C, protected from light | Applies to the powder |
| Reconstitution solvent | Sterile water or saline | Follow product labeling |
| Solution stability | Shorter than the powder | Refrigerate and use promptly |
| Primary purity method | Reversed-phase HPLC | Detects related substances |
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
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.
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。
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。
The thyroid gland is a butterfly-shaped organ composed of two lobes, left and right, connected by a narrow tissue band, called an "isthmus". It weighs 25 grams in adults, with each lobe being about 5 cm long, 3 cm wide, and 2 cm thick and the isthmus about 1.25 cm in height and width. The gland is usually larger in women than in men, and increases in size during pregnancy. The thyroid is near the front of the neck, lying against and around the front of the larynx and trachea. The thyroid cartilage and cricoid cartilage lie just above the gland, below the Adam's apple. The isthmus extends from the second to third rings of the trachea, with the uppermost part of the lobes extending to the thyroid cartilage and the lowermost around the fourth to sixth tracheal rings. The infrahyoid muscles lie in front of the gland and the sternocleidomastoid muscle to the side. Behind the outer wings of the thyroid lie the two carotid arteries. The trachea, larynx, lower pharynx and esophagus all lie behind the thyroid. In this region, the recurrent laryngeal nerve and the inferior thyroid artery pass next to or in the ligament. Typically, four parathyroid glands, two on each side, lie on each side between the two layers of the thyroid capsule, at the back of the thyroid lobes. The thyroid gland is covered by a thin fibrous capsule, which has an inner and an outer layer. The inner layer extrudes into the gland and forms the septa that divide the thyroid tissue into microscopic lobules.
The final years of the Meiji era were also marked by the annexation of Korea in 1910. Its colonial rule would persist until Japan's defeat and surrender in World War II in 1945 during the middle of the Shōwa period and would have lasting negative repercussions on foreign relations between Japan and both North and South Korea.
The pathway of wing expansion is regulated by a signal-receptor pathway, where the neurohormone bursicon interacts with its complementary G protein-coupled receptor; this receptor drives one of the G-protein subunits to signal further enzyme activity and results in development in the wing, such as apoptosis and growth. se: sepia – The eye color of the sepia mutant is sepia, a reddish-brown color. In wild-type flies, ommochromes (brown) and drosopterins (red) give the eyes the typical red color. The drosopterins are made via a pathway that involves a pyrimidodiazepine synthase, which is encoded on chromosome 3L. The gene has a premature stop codon in sepia flies, so that the flies cannot produce the pyrimidodiazepine synthase and thus no red pigment, so that the eyes stay sepia. The sepia allele is recessive and thus offspring from sepia flies and homozygous wild type flies, has red eyes. The sepia phenotype does not depend on the sex of the fly. v: vermilion – The vermilion mutants cannot produce the brown ommochromes leaving the red drosopterins so that the eyes are vermilion colored (a radiant red) compared to a wild-type D. melanogaster. The vermilion mutation is sex-linked and recessive. The gene that is defective lies on the X chromosome. The brown ommochromes are synthesised from kynurenine, which is made from tryptophane. Vermilion flies cannot convert tryptophane into kynurenine and thus cannot make ommochromes, either. Vermilion mutants live longer than wild-type flies.
=== Prevalence and trends === Cocaine production, seizures, and use all reached record levels in 2023, making it the world's fastest-growing illicit drug market. Seizures rose by 68% from 2019 to 2023, while the number of users increased from 17 million in 2013 to 25 million in 2023, according to the UNODC World Drug Report 2025. Concurrently, record levels of cocaine production have enabled traffickers to enter new markets across Asia and Africa, reflecting the expanding global reach of cocaine trafficking. The U.S. is disproportionately the world's largest consumer of cocaine, while South America, collectively as a continent, ranks third in terms of consumer market size. Europe ranks cocaine as the second most commonly used illicit drug. Cocaine is among the most widely consumed recreational stimulants worldwide.
Liquid Scintillation Counting, University of Wisconsin–Milwaukee Radiation Safety Program Principles and Applications of Liquid Scintillation Counting, National Diagnostics K. Regan, "Cerenkov counting technique for beta particles: advantages and limitations". J. Chem. Educ., August 1983, 60 (8), 682–684. doi:10.1021/ed060p682
Sources: en.wikipedia.org
290 aircraft; more than 20,000 employees; 5.2 million square feet of building space (about 90 football fields). the capacity to handle 115 packages per second (equivalent to 416,000 packages flowing through its facilities every hour);
Citric and ascorbic acids target enzymes that degrade fruits and vegetables, e.g., mono/polyphenol oxidase which turns surfaces of cut apples and potatoes brown. Ascorbic acid and tocopherol, which are vitamins, are common preservatives. Smoking entails exposing food to a variety of phenols, which are antioxidants. Natural preservatives include rosemary and oregano extract, hops, salt, sugar, vinegar, alcohol, diatomaceous earth and castor oil. Traditional preservatives, such as sodium benzoate have raised health concerns in the past. Benzoate was shown in a study to cause hypersensitivity in some asthma sufferers. This has caused reexamination of natural preservatives which occur in vegetables.
== Definitions == Corrective rape is the use of rape against people who do not conform to perceived social norms regarding human sexuality or gender roles. The goal is to punish perceived abnormal behavior and reinforce societal norms. The crime was first identified in South Africa, where it is sometimes supervised by members of the woman's family or local community. One of the earliest known mentions of the term is by South African feminist activist Bernedette Muthien during an August 2001 interview by Human Rights Watch in Cape Town:
=== Introduction and History of DNA Legos === DNA origami has been used to assemble a range of two-dimensional and three-dimensional nanostructures; however, each different structure requires a new design and a new set of scaffold strand and staple strands. This limits scalability and structure yield efficiency. Researchers have developed “DNA brick” or “DNA Lego” technologies by making single stranded tiles (SSTs). SSTs allow for the production of larger structures without a scaffold strand and with the ease of arranging the predesigned blocks into bigger structures. Much like how actual Lego bricks allow specific assembly configurations, DNA Lego bricks bind at specific sites to form a range of shapes. Appropriate selection of blocks to include in an assembly mixture allows production of a variety of complex 3D shapes without a scaffold strand and without having to design an entirely different structure. With the DNA Lego brick approach, the DNA strand binds to neighboring strands to form a “brick”. By selecting subsets of strands to form a larger shape, researchers demonstrated that many 3D structures could be assembled from the same general set of components or bricks. The authors called this a “voxel-based” design strategy meaning that each 8-base pair interaction between bricks defines a voxel with dimensions 2.5 by 2.5 nm. Since each DNA interaction can be analogized to Lego construction, we can also claim one voxel corresponds to one stud Lego brick . This scaffold-free strategy has also been extended to larger multicomponent structures.
=== Other === Levamisole has been used to treat a variety of dermatologic conditions, including skin infections, leprosy, warts, lichen planus, and aphthous ulcers. An interesting side effect these reviewers reported in passing was "neurologic excitement". Later papers, from the Janssen group and others, indicate levamisole and its enantiomer, dexamisole, have some mood-elevating or antidepressant properties, although this was never a marketed use of the drug.
Sources: en.wikipedia.org
1927 (Chemistry) Heinrich Otto Wieland — Constitution of bile acids and sterols and their connection to vitamins 1928 (Chemistry) Adolf Otto Reinhold Windaus — Constitution of sterols and their connection to vitamins 1939 (Chemistry) Adolf Butenandt and Leopold Ružička — Isolation and structural studies of steroid sex hormones, and related studies on higher terpenes 1950 (Physiology or Medicine) Edward Calvin Kendall, Tadeus Reichstein, and Philip Hench — Structure and biological effects of adrenal hormones 1965 (Chemistry) Robert Burns Woodward — In part, for the synthesis of cholesterol, cortisone, and lanosterol 1969 (Chemistry) Derek Barton and Odd Hassel — Development of the concept of conformation in chemistry, emphasizing the steroid nucleus 1975 (Chemistry) Vladimir Prelog — In part, for developing methods to determine the stereochemical course of cholesterol biosynthesis from mevalonic acid via squalene
Blount immediately moved to White's Fort (chosen for its central location) to begin resolving land disputes between the Cherokee and white settlers in the region. In the Summer of 1791, he met with forty-one Cherokee chiefs at the mouth of First Creek to negotiate the Treaty of Holston, which was signed on July 2 of that year. The treaty moved the boundary of Cherokee lands westward to the Clinch River and southwestward to the Little Tennessee River. While Blount initially sought to place the territorial capital at the confluence of the Clinch and Tennessee rivers (near modern Kingston), where he had land claims, he was unable to convince the Cherokee to completely relinquish this area, and thus settled on White's Fort as the capital. James White set aside land for a new town, which initially consisted of the area now bounded by Church Avenue, Walnut Street, First Creek, and the river, in what is now Downtown Knoxville. White's son-in-law, Charles McClung, surveyed the land and divided it into 64 half-acre lots. Lots were set aside for a church and cemetery, a courthouse, a jail, and a college. On October 3, 1791, a lottery was held for those wishing to purchase lots in the new city, which was named "Knoxville" in honor of Blount's superior, Secretary of War Henry Knox.
Basic diagnostic medical devices (e.g., stethoscope, tongue depressor) are typically used. After examining for signs and interviewing for symptoms, the doctor may order medical tests (e.g., blood tests), take a biopsy, or prescribe pharmaceutical drugs or other therapies. Differential diagnosis methods help to rule out conditions based on the information provided. During the encounter, properly informing the patient of all relevant facts is an important part of the relationship and the development of trust within the context of the doctor-patient relationship. The medical encounter is then documented in the medical record, which is a legal document in many jurisdictions. Follow-up encounters may be shorter but follow the same general procedure, and specialists follow a similar process. The diagnosis and treatment may take only a few minutes or a few weeks, depending on the complexity of the issue. The components of the medical interview and encounter are:
Theodor Curtius was born in Duisburg in the Ruhr area in Germany. He studied chemistry with Robert Bunsen at Heidelberg University and with Hermann Kolbe at Leipzig University. He received his doctorate in 1882 at Leipzig University. After working from 1884 to 1886 for Adolf von Baeyer at the Ludwig-Maximilians-Universität München, Curtius became the director of the analytical chemistry department at University of Erlangen until 1889. Then he accepted the chair in Chemistry at Kiel University, where he remained very productive. In line with this success, Curtius was appointed Geheimer Regierungsrat (Privy Councillor) in 1895. After a one-year appointment as the successor of the famous August Kekulé at the University of Bonn in 1897, Curtius succeeded Victor Meyer as Professor of Chemistry at his old university at Heidelberg University in 1898, where he remained until his retirement in 1926. He was awarded honorary membership of the Manchester Literary and Philosophical Society in 1892 and was succeeded by Karl Freudenberg, who wrote Curtius' biography in 1962.[1] In his free time, he also composed music, sang in concerts, and was an active mountaineer. In 1894, he founded the Kiel section of the Association of German and Austrian Alpinists, which he personally supported with gifts. In his Munich period, he became a close friend of the alpinist guide Christian Klucker, with whom he made mountaineering hikes for many years thereafter. Theodor Curtius died in Heidelberg on 8 February 1928.
Alcohol has a variety of short-term and long-term adverse effects. Alcohol has both short-term, and long-term effects on the memory, and sleep. It also has reinforcement-related adverse effects, including alcoholism, dependence, and withdrawal. Alcohol use is directly related to considerable morbidity and mortality, for instance due to intoxication and alcohol-related health problems. The World Health Organization advises that there is no safe level of alcohol consumption. Many of the toxic and unpleasant actions of alcohol in the body are mediated by its carcinogenic byproduct acetaldehyde.
Sources: en.wikipedia.org
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.
Reversed-phase HPLC is the primary tool for purity, paired with mass spectrometry for identity. Amino acid analysis and peptide mapping add sequence confirmation. Several techniques are combined because no single test covers every attribute.
It lacks sulfur-containing residues, so oxidation is limited. Aspartate isomerization and slow hydrolysis are the main concerns. Solution stability is shorter than that of the lyophilized powder.
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.