This is a working overview of immune modulation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-08-10 and is reviewed periodically as new material appears.
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。
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.
| 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 |
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.
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 synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
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.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
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.
=== Metabolism === The metabolism of the compound primarily occurs in the liver through both reduction and conjugation pathways. A major metabolic step involves the reduction of the quinone to its corresponding hydroquinone. The main metabolic route is the detoxification via conjugation with glutathione (GSH). This phase II metabolism reaction serves to neutralize the compound's electrophilicity, facilitating safer elimination. Nevertheless, excessive or chronic exposure may lead to the depletion of cellular GSH pools, which enhances oxidative stress and potential cellular damage. The subsequent processing of these glutathione conjugates results in the formation of cysteine conjugates and mercapturic acids.
=== Academic career === From 1943 to 1955, Fox was a full professor at Iowa State College. Fox became the head of the Iowa Agricultural Experimental Station's Chemistry Department from 1949 to 1955. In 1955, Sidney W. Fox moved to Florida State University and held the position of Professor of Chemistry, Director of the Oceanographic Institute, and Director of the Institute for Space Biosciences. In 1964, Fox moved to the University of Miami where he was a professor and the director of the Institute for Molecular Evolution for 25 years. The program was supported by the National Aeronautics and Space Administration (NASA). Fox also taught at the Southern Illinois University in the Department of Plant Biology as a Distinguished Research Professor. From there, Fox moved to the University of South Alabama where he was entitled Distinguished Research Scientist in the Marine Sciences department in 1993.
=== Single particles === Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was designed for particle suspensions in 2000 by Claude Degueldre. He first tested this new methodology at the Forel Institute of the University of Geneva and presented this approach at the 'Colloid 2oo2' symposium during the spring 2002 meeting of the EMRS, and in the proceedings in 2003. This study presents the theory of SP ICP-MS and the results of tests carried out on clay particles (montmorillonite) as well as other suspensions of colloids. This method was then tested on thorium dioxide nanoparticles, zirconium dioxide and gold nanoparticles and uranium dioxide nano- and micro-particles.
Sources: en.wikipedia.org
Actin plays a particularly prominent role in muscle cells, which consist largely of repeated bundles of actin and myosin II. Each repeated unit – called a sarcomere – consists of two sets of oppositely oriented F-actin strands ("thin filaments"), interlaced with bundles of myosin ("thick filaments"). The two sets of actin strands are oriented with their (+) ends embedded in either end of the sarcomere in delimiting structures called Z-disks. The myosin fibrils are in the middle between the sets of actin filaments, with strands facing in both directions. When the muscle contracts, the myosin threads move along the actin filaments towards the (+) end, pulling the ends of the sarcomere together and shortening it by around 70% of its length. In order to move along the actin thread, myosin must hydrolyze ATP; thus ATP serves as the energy source for muscle contraction. At times of rest, the proteins tropomyosin and troponin bind to the actin filaments, preventing the attachment of myosin. When an activation signal (i.e. an action potential) arrives at the muscle fiber, it triggers the release of Ca2+ from the sarcoplasmic reticulum into the cytosol. The resulting spike in cytosolic calcium rapidly releases tropomyosin and troponin from the actin thread, allowing myosin to bind, and muscle contraction to begin.
The illegal drug trade in Latin America concerns primarily the production and sale of cocaine and cannabis, including the export of these banned substances to the United States and Europe. According to United Nations Office on Drugs and Crime (UNODC), the coca cultivation is concentrated in the Andes of South America, particularly in Colombia, Peru and Bolivia; this is the world's only source region for coca. Drug consumption in Latin America remains relatively low, but cocaine in particular has increased in recent years in countries along the major smuggling routes. As of 2008, the primary pathway for drugs into the United States is through Mexico and Central America, though crackdowns on drug trafficking by the Mexican government has forced many cartels to operate routes through Guatemala and Honduras instead. This is a shift from the 1980s and early 90s, when the main smuggling route was via the Caribbean into Florida. The United States is the primary destination, but around 25 to 30% of global cocaine production travels from Latin America to Europe, typically via West Africa. The major drug trafficking organizations (drug cartels) are Mexican and Colombian, and said to generate a total of $18 to $39bn in wholesale drug proceeds per year. Mexican cartels are currently considered the "greatest organized crime threat" to the United States.
== Management == Currently there is not a 100% effective way to eradicate P. syringae from a field. The most common way to control this pathogen is to spray bactericides with copper compounds or other heavy metals that can be combined with fungicides or other pest control chemicals. Chemical treatments with fixed copper such as Bordeaux, copper hydroxide, and cupric sulfate are used to stop the spread of P. syringae by killing the bacteria while it is in the epiphyte stage on leaves, or woody parts of trees - however resistant P. syringae strains do exist. Spraying antibiotics such as streptomycin and organic bactericides is another way to control P. syringae but is less common than the methods listed above. New research has shown that adding ammonium (NH4+) nutrition to tomato plants can cause a metabolic change leading to resistance against Pseudomonas syringae. This "ammonium syndrome" causes nutrient imbalances in the plant and therefore triggers a defense response against the pathogen. Strict hygiene practices used in orchards along with pruning in early spring and summer were proven to make the trees more resistant to P. syringae. Cauterizing cankers found on orchard trees can save the tree's life by stopping the infection from spreading. Breeding plants for resistance is another somewhat effective way to avoid P. syringae. It has been successful in the cherry rootstock with Pseudomonas syringae pv. syringae, but so far, no other species are 100% resistant to this pathogen. Resistance breeding is a slow process, especially in trees. Unfortunately, P.
Sources: en.wikipedia.org
=== Hot air drying in drying chamber === Compact flowers like marigolds, chrysanthemums, cornflowers and zinnias dry well in a fan-assisted, convection chamber. Non-ventilated chambers are not appropriate, because they generate too much moisture. The material must be dried at a low temperature (30-35˚Celsius), over many hours. The flowers are slotted through holes in a wire mesh rack leaving room for the stems to dangle below. The time required depends upon the density of the flowers.
In the 17th century Guillaume Amontons discovered a regular relationship between the pressure and temperature of a gas at constant volume. Some introductory physics textbooks still define the pressure-temperature relationship as Gay-Lussac's law. Gay-Lussac primarily investigated the relationship between volume and temperature and published it in 1802, but his work did cover some comparison between pressure and temperature. Given the relative technology available to both men, Amontons could only work with air as a gas, whereas Gay-Lussac was able to experiment with multiple types of common gases, such as oxygen, nitrogen, and hydrogen.
The Enhanced Games (TEG) is a multi-sport event. Founded by Australian businessman Aron D'Souza, it allows athletes to use performance-enhancing substances without being subject to drug tests; organizers claim these substances must be FDA-approved and used under medical supervision. D'Souza stated that he founded the Games based on the principle of bodily autonomy for athletes, further alleging that the International Olympic Committee (IOC) maintains an exploitative relationship with competitors. Reactions from the sporting world, scientific community, and media outlets have generally been negative, with commentators highlighting the safety risks of encouraging performance-enhancing drug use. The first event took place on 24 May 2026 in Las Vegas, and included competitions in swimming, athletics, and weightlifting.
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。
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.