免疫组织 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-05-27 and is reviewed periodically as new material appears.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
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.
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。
| Property | Value | Notes |
|---|---|---|
| First described | 1977 | Reported as a component of thymosin fraction 5 |
| Sequence length | 28 amino acids | N-terminal residue is acetylated |
| Net charge at neutral pH | Negative | Reflects a high proportion of acidic residues |
| Principal studied uses | Chronic hepatitis B and vaccine adjuvant | Research uses outnumber approved indications |
| Regulatory status | Approved in a limited number of countries | Not approved in the United States or most of Europe |
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.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
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.
The first 7-Eleven in Australia opened on 24 August 1977, in the Melbourne suburb of Oakleigh. The majority of stores are located in metropolitan areas, particularly in central business district areas. Stores in suburban areas often operate as petrol stations and most are owned and operated as franchises, with a central administration. 7-Eleven bought Mobil's remaining Australian petrol stations in 2010, converting them to 7-Eleven convenience store / petrol stations. In South Australia all Mobil petrol stations were later sold to Peregrine Corporation and rebranded to OTR convenience store / petrol stations. In April 2014, 7-Eleven announced plans to start operating stores in Western Australia, with 11 stores planned to operate within the first year and a total of 75 stores established within five years. The first store was opened on October 30, 2014, in the city of Fremantle. The country has 675 stores as of January 2018. In April 2022, 7-Eleven Australia settled a class-action lawsuit from its franchisees for A$98 million, amid claims that it had misled franchisees about the profitability of its business model. In December 2023, Seven & I Holdings of Japan agreed to purchase the Australian 7-Eleven franchise from its original franchise owners for A$1.71 billion. The purchase was finalized in April 2024.
The history of fungaria is closely tied to the early development of botanical herbaria, the oldest of which date to the mid-1500s. Fungal fruiting bodies have been collected and deposited for several centuries, with millions of specimens accumulated chiefly to support fungal taxonomy. Early collections were often personal assemblages or teaching aids used to distinguish edible mushrooms from poisonous ones. Over time, fungal herbaria shifted from keeping one or a few representative specimens per taxon toward documenting developmental stages and geographic variation within species more broadly. In some regions, fungaria developed in close association with government plant-pathology programmes; in South Africa, for example, organised collecting expanded after the creation of a mycology post in 1905 and a separate Division of Plant Pathology and Mycology in 1910, whose early staff built the nucleus of the Pretoria herbarium. At the Royal Botanic Gardens, Kew, the mycological collection was established in the late 19th century after the donation of more than 10,000 fungal specimens by the mycologist Reverend Miles Joseph Berkeley. It was later enlarged through donations and collecting by staff and collaborators. More generally, fungaria were often built through a combination of personal collections, academic donations, and purchased exsiccatae series, drawing on wider networks of scientific exchange among mycologists.
==== Circulation ==== Circulation within local systems, such as bays, estuaries, and groundwater, may be examined with radium isotopes. 223Ra has a half-life of 11 days and can occur naturally at specific locations in rivers and groundwater sources. The isotopic ratio of radium will then decrease as the water from the source river enters a bay or estuary. By measuring the amount of 223Ra at a number of different locations, a circulation pattern can be deciphered. This same exact process can also be used to study the movement and discharge of groundwater. Various isotopes of lead can be used to study circulation on a global scale. Different oceans (i.e. the Atlantic, Pacific, Indian, etc.) have different isotopic signatures. This results from differences in isotopic ratios of sediments and rocks within the different oceans. Because the different isotopes of lead have half-lives of 50–200 years, there is not enough time for the isotopic ratios to be homogenized throughout the whole ocean. Therefore, precise analysis of Pb isotopic ratios can be used to study the circulation of the different oceans.
Food in Hong Kong is primarily based on Cantonese cuisine, despite the territory's exposure to foreign influences and its residents' varied origins. Rice is the staple food, and is usually served plain with other dishes. Freshness of ingredients is emphasised. Poultry and seafood are commonly sold live at wet markets, and ingredients are used as quickly as possible when still fresh. There are up to five daily meals: breakfast, lunch, afternoon tea, dinner, and siu yeh. Dim sum, as part of yum cha (brunch), is a dining-out tradition with family and friends. Dishes include congee, cha siu bao, siu yuk, egg tarts, and mango pudding. Local versions of Western food are served at cha chaan teng (Hong Kong-style cafes). Common cha chaan teng menu items include macaroni in soup, deep-fried French toast, and Hong Kong-style milk tea. As of 2025, the Michelin Guide listed 76 starred restaurants in total. It awarded 7 restaurants 3 Michelin Stars, 11 restaurants with 2 Michelin Stars, and 58 restaurants with 1 Michelin Star. It also gave 4 Green Stars for sustainability, Amber, Feuille, Mora, and Roganic. Alongside the starred list, 65 restaurants received Bib Gourmand status for good quality food at good value.
Sources: en.wikipedia.org
== Further reading == Bard, Allen J.; Larry R. Faulkner (2000-12-18). Electrochemical Methods: Fundamentals and Applications (2 ed.). Wiley. ISBN 978-0-471-04372-0. Zoski, Cynthia G. (2007-02-07). Handbook of Electrochemistry. Elsevier Science. ISBN 978-0-444-51958-0. Kissinger, Peter; William R. Heineman (1996-01-23). Laboratory Techniques in Electroanalytical Chemistry, Second Edition, Revised and Expanded (2 ed.). CRC. ISBN 978-0-8247-9445-3. Gosser, David K. (1993-09-20). Cyclic Voltammetry Simulation and Analysis of Reaction Mechanisms. VCH. ISBN 978-1-56081-026-1. Compton, Richard D.; Craig E. Banks (2010-11-15). Understanding Voltammetry (2 ed.). Imperial College Press. ISBN 978-1848165854.
Although naturally occurring double-strand breaks occur at a relatively low frequency in DNA, their repair often causes mutation. Non-homologous end joining (NHEJ) is a major pathway for repairing double-strand breaks. NHEJ involves removal of a few nucleotides to allow somewhat inaccurate alignment of the two ends for rejoining followed by addition of nucleotides to fill in gaps. As a consequence, NHEJ often introduces mutations.
Research and development as well as production, however, remain at the Herisau site. Metrohm AG moved from the town center of Herisau in 2011 to its new premises in the industrial zone "Hölzli". The new premises were expanded in 2015 to accommodate the growing number of employees. In summer 2024, Metrohm expanded its Herisau campus by an additional 20,000 square meters. In 2025, Metrohm established new subsidiaries in Korea, Portugal and Ghana.
The stratosphere is the second-lowest layer of Earth's atmosphere, located above the troposphere and below the mesosphere. Pronounced , the name originates from Ancient Greek στρωτός (strōtós) 'layer, stratum' and -sphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher (closer to outer space) and the cooler layers lower (closer to the planetary surface of the Earth). The increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet (UV) radiation by the ozone layer, where ozone is exothermically photolyzed into oxygen in a cyclical fashion. This temperature inversion is in contrast to the troposphere, where temperature decreases with altitude, and between the troposphere and stratosphere is the tropopause border that demarcates the beginning of the temperature inversion. Near the equator, the lower edge of the stratosphere is as high as 20 km (66,000 ft; 12 mi), at mid-latitudes around 10 km (33,000 ft; 6.2 mi), and at the poles about 7 km (23,000 ft; 4.3 mi). Temperatures range from an average of −51 °C (−60 °F; 220 K) near the tropopause to an average of −15 °C (5.0 °F; 260 K) near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near 60 m/s (220 km/h; 130 mph) in the Southern polar vortex.
Kombucha can be prepared at home or commercially. It is made by dissolving sugar in non-chlorinated boiling water. Tea leaves are then steeped in the hot sugar water and discarded. The sweetened tea is cooled and the SCOBY culture is added. The mixture is then poured into a sterilized beaker along with previously fermented kombucha tea to lower the pH. This technique is known as "backslopping". The container is covered with a paper towel or breathable fabric to prevent insects, such as fruit flies, from contaminating the kombucha. The tea is left to ferment for a period of up to 10 to 14 days at room temperature, 18–26 °C (64–79 °F). A new "daughter" SCOBY will form on the surface of the tea to the diameter of the container. After fermentation is completed, the SCOBY is removed and stored along with a small amount of the newly fermented tea. The remaining kombucha is strained and bottled for a secondary ferment for a few days or stored at 4 °C (39 °F).
Sources: en.wikipedia.org
Trials differ in patient population, dose schedule, background treatment, and the endpoints used to judge success. Many are small and single-center, so random variation can dominate the reported effects.
Authorization is limited to a small number of countries and covers specific indications such as chronic hepatitis B and vaccine adjuvant use. Availability and labelling differ by jurisdiction.
Most reviews describe it as an immunomodulatory agent with an uncertain clinical effect. They generally call for larger, better-controlled trials before firm conclusions are drawn.
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。