The short version of immunomodulator fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-01 and is reviewed periodically as new material appears.
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。
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.
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.
| 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 |
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 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.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
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 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.
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.
=== Tobacco products === The FDA regulates tobacco products with authority established by the 2009 Family Smoking Prevention and Tobacco Control Act. This act requires color warnings on cigarette packages and printed advertising, and text warnings from the U.S. surgeon general. The nine new graphic warning labels were announced by the FDA in June 2011 and were scheduled to be required to appear on packaging by September 2012. The implementation date is uncertain, due to ongoing proceedings in the case of R.J. Reynolds Tobacco Co. v. U.S. Food and Drug Administration. R.J. Reynolds, Lorillard, Commonwealth Brands, Liggett Group and Santa Fe Natural Tobacco Company have filed suit in Washington, D.C. federal court claiming that the graphic labels are an unconstitutional way of forcing tobacco companies to engage in anti-smoking advocacy on the government's behalf. A First Amendment lawyer, Floyd Abrams, is representing the tobacco companies in the case, contending requiring graphic warning labels on a lawful product cannot withstand constitutional scrutiny. The Association of National Advertisers and the American Advertising Federation have also filed a brief in the suit, arguing that the labels infringe on commercial free speech and could lead to further government intrusion if left unchallenged. In November 2011, federal judge Richard Leon of the U.S. District Court for the District of Columbia temporarily halted the new labels, likely delaying the requirement that tobacco companies display the labels. The U.S. Supreme Court ultimately could decide the matter.
== History == The process is named after the Dutch physicist Frans Michel Penning who first reported it in 1927. Penning started to work at the Philips Natuurkundig Laboratorium at Eindhoven to continue the investigation of electric discharge on rare gases. Later, he started measurements on the liberation of electrons from metal surfaces by positive ions and metastable atoms, and especially on the effects related to ionization by metastable atoms.
When a vegetable is harvested, it is cut off from its source of water and nourishment. It continues to transpire and loses moisture as it does so, a process most noticeable in the wilting of green leafy crops. Harvesting root vegetables when they are fully mature improves their storage life, but alternatively, these root crops can be left in the ground and harvested over an extended period. The harvesting process should seek to minimise damage and bruising to the crop. Onions and garlic can be dried for a few days in the field and root crops such as potatoes benefit from a short maturation period in warm, moist surroundings, during which time wounds heal and the skin thickens up and hardens. Before marketing or storage, grading needs to be done to remove damaged goods and select produce according to its quality, size, ripeness, and color.
==== P ==== Instant mashed potatoes – have been through an industrial process of cooking, mashing and dehydrating to yield a packaged convenience food that can be reconstituted in the home in seconds by adding hot water and/or milk, producing a close approximation of mashed potatoes with very little expenditure of time and effort. A similar product is dehydrated shredded potatoes.
Sources: en.wikipedia.org
An embalmer is someone who has been trained and qualified in the art and science of sanitization, presentation, and preservation of the human deceased. The term mortician is far more generic; it may refer to someone who is a funeral director, an embalmer, or just a person who prepares the deceased, with or without the formal qualification of an embalmer. Thus while all embalmers are morticians, many morticians are not embalmers and the terms are not intrinsically synonymous. Embalming training commonly involves formal study in anatomy, thanatology, chemistry, and specific embalming theory (to widely varied levels depending on the region of the world one lives in) combined with practical instruction in a mortuary with a resultant formal qualification granted after the passing of a final practical examination and acceptance into a recognized society of professional embalmers. The roles of a funeral director and embalmer are different, depending on local customs and the licensing body of the region in which they both operate. A funeral director arranges for the final disposition of the deceased, and may or may not prepare the deceased (by embalming, preparing for viewing or other legal requirements). Legal requirements over who can practice vary geographically. Some regions or countries do not have specific requirements, while others have clear prohibitions. In the United States, the title of an embalmer is largely based on the state in which they are licensed.
The condition known today as diabetes (usually referring to diabetes mellitus) is thought to have been described in the Ebers Papyrus (c. 1550 BC). Ayurvedic physicians (5th/6th century BC) first noted the sweet taste of diabetic urine, and called the condition madhumeha ("honey urine"). The term diabetes traces back to Demetrius of Apamea (1st century BC). For a long time, the condition was described and treated in traditional Chinese medicine as xiāo kě (消渴; "wasting-thirst"). Physicians of the medieval Islamic world, including Avicenna, have also written on diabetes. Early accounts often referred to diabetes as a disease of the kidneys. In 1674, Thomas Willis suggested that diabetes may be a disease of the blood. Johann Peter Frank is credited with distinguishing diabetes mellitus and diabetes insipidus in 1794. In regard to diabetes mellitus, Joseph von Mering and Oskar Minkowski are commonly credited with the formal discovery (1889) of a role for the pancreas in causing the condition. In 1893, Édouard Laguesse suggested that the islet cells of the pancreas, described as "little heaps of cells" by Paul Langerhans in 1869, might play a regulatory role in digestion. These cells were named islets of Langerhans after the original discoverer. In the beginning of the 20th century, physicians hypothesized that the islets secrete a substance (named "insulin") that metabolises carbohydrates. The first to isolate the extract used, called insulin, was Nicolae Paulescu.
The Na+/I− symporter transports two sodium ions across the basement membrane of the follicular cells along with an iodide ion. This is a secondary active transporter that utilises the concentration gradient of Na+ to move I− against its concentration gradient. This is called iodide trapping. Sodium is cotransported with iodide from the basolateral side of the membrane into the cell, and then concentrated in the thyroid follicles to about thirty times its concentration in the blood. I− is moved across the apical membrane into the colloid of the follicle by pendrin. Hydrogen peroxide is also introduced into the follicle by the action of DUX (Dual Oxidase). Iodide is non-reactive, and the reactive I2 species is required for the next step. Thyroid peroxidase (TPO) reduces hydrogen peroxide to water by transferring one electron from two I− atoms that react to form I2. Iodine (I2) is converted into HOI, by hydration with water. Both I2 and HOI iodinate specific tyrosyl residues of the thyroglobulin within the colloid to form 3-monoiodityrosyl (MIT-yl) and 3,5-diiodityrosyl (DIT-yl) residues—introducting iodine atoms at one or both locations ortho to the hydroxyls of tyrosine. The thyroglobulin was synthesised in the ER of the follicular cell and secreted into the colloid. TPO also converts tyrosyl, MIT-yl, and DIT-yl residues into their free radical forms. These forms attack other MIT-yl and DIT-yl residues. When a DIT-yl radical attacks a DIT, T4-yl (peptidic T4) is formed. When a MIT-yl radical attacks a DIT, T3-yl is formed.
==== Elimination ==== Minoxidil is excreted almost exclusively (>97%) in urine. About 10 to 15% is excreted in urine unchanged. The elimination half-life of oral minoxidil is about 3 to 4 hours. Conversely, the half-life of topical minoxidil is 22 hours on average. Oral minoxidil is excreted within 12 to 20 hours in urine. Despite this however, the hypotensive effect of oral minoxidil lasts approximately 72 hours following a single dose. With discontinuation of topical minoxidil, about 95% of systemically absorbed minoxidil is excreted within 4 days. The renal clearance of oral minoxidil is 352 mL/minute.
=== 1946 === January: The Chinese Civil War resumed between Communist and Nationalist forces. January 7: The Republic of Austria is reconstituted, with its 1937 borders, but divided into four zones of control: American, British, French, and Soviet. January 11: Enver Hoxha declares the People's Republic of Albania, with himself as Prime Minister. February 9: Joseph Stalin makes his Election Speech, in which he states that capitalism and imperialism make future wars inevitable. February 22: George F. Kennan writes his Long Telegram, describing his interpretation of the objectives and intentions of the Soviet leadership. March: The Greek Civil War reignites between the communists and the Kingdom of Greece. March 2: British soldiers withdraw from their zone of occupation in southern Iran. Soviet soldiers remain in their northern sector. March 5: Winston Churchill warns of the descent of an Iron Curtain across Europe. Named by Winston Churchill, the aim of the Iron Curtain was to create a divide between the developing countries in Europe and the ones still under political influence and dictatorship (Soviet Union). March 6: The Ho–Sainteny Agreement recognizes the Democratic Republic of Vietnam as a "free state" within the French Union. The French replace Chinese Nationalist forces in North Vietnam. Vietnamese non-nationalist parties are to be eliminated by the Viet Minh with French assistance. May 25: The Treaty of London comes into effect, granting the Amirate of Trans-Jordan independence from the United Kingdom as the Hashemite Kingdom of Transjordan.
Sources: en.wikipedia.org
A sperm bank, semen bank, or cryobank is a facility that purchases, stores, and sells human semen. The semen is produced and sold by men who are known as sperm donors. The sperm is purchased by other persons for the purpose of achieving a pregnancy other than by a sexual partner. Sperm sold by a sperm donor is known as donor sperm. A sperm bank may be a separate entity supplying donor sperm to individuals or to fertility clinics, or it may be a facility which is run by a clinic for their customers. A pregnancy may be achieved using donor sperm for insemination with similar outcomes to sexual intercourse. By using sperm from a donor rather than from the sperm recipient's partner, the process is a form of third party reproduction. In the 21st century artificial insemination with donor sperm from a sperm bank is most commonly used for individuals with no male partner, such as single women and coupled lesbians. A sperm donor must generally meet specific requirements regarding age and screening for adverse medical history. In the United States, sperm banks are regulated as Human Cell and Tissue or Cell and Tissue Bank Product (HCT/Ps) establishments by the Food and Drug Administration. Many states in the U.S. also have regulations in addition to those imposed by the FDA. In the European Union a sperm bank must have a license, according to the EU Tissue Directive. In the United Kingdom, sperm banks are regulated by the Human Fertilisation and Embryology Authority.
Methods used for desulfurization include, among others, hydrodesulfurization, oxidative desulfurization, extractive desulfurization, and extraction by ionic liquids. Despite their efficiency at reducing sulfur content, the conventional desulfurization methods are still accountable for a significant amount of the CO2 emissions associated with the crude oil refining process, releasing up to 9000 metric tons per year. Furthermore, these processes usually require large amounts of energy, and are accompanied by massive costs for the industries that employ them. A greener and also complementary alternative process to the conventional desulfurization methods is biodesulfurization.
=== Short-term training programmes === These are conducted at RCB by inducting post-graduate students of science from various universities/institutions/colleges to carry out their project/ dissertation work towards partial fulfillment of their postgraduate degrees.
=== Terpolymers === Terpolymers of PVDF are the most promising one in terms of electromechanically induced strain. The most commonly used PVDF-based terpolymers are P(VDF-TrFE-CTFE) and P(VDF-TrFE-CFE). This relaxor-based ferroelectric terpolymer is produced by random incorporation of the bulky third monomer (chlorotrifluoroethylene, CTFE) into the polymer chain of P(VDF-TrFE) copolymer (which is ferroelectric in nature). This random incorporation of CTFE in P(VDF-TrFE) copolymer disrupts the long-range ordering of the ferroelectric polar phase, resulting in the formation of nano-polar domains. When an electric field is applied, the disordered nano-polar domains change their conformation to all-trans conformation, which leads to large electrostrictive strain and a high room-temperature dielectric constant of ~50.
Skp, Cullin, F-box containing complex (or SCF complex) is a multi-protein E3 ubiquitin ligase complex that catalyzes the ubiquitination of proteins destined for 26S proteasomal degradation. Along with the anaphase-promoting complex, SCF has important roles in the ubiquitination of proteins involved in the cell cycle. The SCF complex also marks various other cellular proteins for destruction.
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。
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.