A practical reference on lyophilization: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-03 and is reviewed periodically as new material appears.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
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。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Acetylated peptide | N-terminal acetyl group blocks aminopeptidase attack |
| Residue count | 28 amino acids | Matches the N-terminus of prothymosin alpha |
| Molecular mass | About 3,108 Da | Value for the free, unmodified peptide |
| Isoelectric point | Approximately 4.2 | Acidic; net negative charge at neutral pH |
| Encoding gene | PTMA | Human gene for the precursor protein |
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.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
=== Efforts to reduce recreational use in the US === In 2011, the Obama administration released a white paper describing the administration's plan to deal with the opioid crisis. The administration's concerns about addiction and accidental overdosing have been echoed by numerous other medical and government advisory groups around the world. As of 2015, prescription drug monitoring programs exist in every state except for Missouri. These programs allow pharmacists and prescribers to access patients' prescription histories in order to identify suspicious use. However, a survey of US physicians published in 2015 found that only 53% of doctors used these programs, while 22% were not aware that the programs were available to them. The Centers for Disease Control and Prevention (CDC) was tasked with establishing and publishing a new guideline, and was heavily lobbied. In 2016, the CDC published its Guideline for Prescribing Opioids for Chronic Pain, recommending that opioids only be used when benefits for pain and function are expected to outweigh risks, and then used at the lowest effective dosage, with avoidance of concurrent opioid and benzodiazepine use whenever possible. Research suggests that the prescription of high doses of opioids related to chronic opioid therapy (COT) can at times be prevented through state legislative guidelines and efforts by health plans that devote resources and establish shared expectations for reducing higher doses. On 10 August 2017, Donald Trump declared the opioid crisis a (non-FEMA) national public health emergency.
== History == On 5 December 2008, orphan designation (EU/3/08/592) was granted by the European Commission to Medimmune Limited, United Kingdom, for murine anti-CD22 antibody variable region fused to truncated Pseudomonas exotoxin 38 for the treatment of hairy cell leukaemia. It was renamed to Moxetumomab pasudotox. The sponsorship was transferred to AstraZeneca AB, Sweden, in January 2019. On 17 July 2013, orphan designation (EU/3/13/1150) was granted by the European Commission to MedImmune Ltd, United Kingdom, for moxetumomab pasudotox for the treatment of B-lymphoblastic leukaemia / lymphoma. The sponsorship was transferred to AstraZeneca AB, Sweden, in January 2019. Moxetumomab pasudotox was approved for use in the United States in September 2018. The efficacy of moxetumomab pasudotox was studied in a single-arm, open-label clinical trial of 80 subjects who had received prior treatment for hairy cell leukemia with at least two systemic therapies, including a purine nucleoside analog. The trial measured durable complete response (CR), defined as maintenance of hematologic remission for more than 180 days after achievement of CR. Thirty percent of subjects in the trial achieved durable CR, and the overall response rate (number of subjects with partial or complete response to therapy) was 75 percent. The US Food and Drug Administration (FDA) granted the application for moxetumomab pasudotox fast track, priority review, and orphan drug designations. The FDA granted the approval of a Biologics License Application for Lumoxiti to AstraZeneca Pharmaceuticals.
The expectation to experience rejection can become an important stressor for transgender and gender non-conforming individuals. Mental health problems among trans people are related to higher rates of self-harm, drug usage, and suicidal ideations and attempts.
Sources: en.wikipedia.org
=== Physical === Physical deterioration of waterlogged wood can happen immediately through the evaporation of the water. If this happens rapidly, the cells in the wood can shrink and collapse. This damage might be inevitable depending on accessibility to treatment. Additionally waterlogged wood should never be handled extensively or put on exhibit for long periods of time. Most waterlogged wood is such that decayed wood cells in the material fill with water. Depending on the wood type and how long the wood has been in water, removal of the water from the cells too rapidly (in the form of natural drying or other) could apply major stress to the cell walls and cause them to collapse. Improperly dried waterlogged irreversibly shrinks, warps, cracks and there is risk of loss to the original surface.
== June 20, 1915 (Sunday) == The town of South Omaha, Nebraska was annexed by the larger city of Omaha, adding 40,000 residents to the city's population. Born: Terence Young, British film director, directed the James Bond films Dr. No, From Russia with Love and Thunderball; as Stewart Terence Herbert Young, in Shanghai International Settlement, Republic of China (present-day Shanghai, China) (d. 1994)
Although Fredrickson claims that her experimental results are still valid, these experimental results have also been questioned due to poor statistical methodology, and Alan Sokal has pointed out that "given [Fredrickson and Losada's] experimental design and method of data analysis, no data whatsoever could possibly give any evidence of any nonlinearity in the relationship between "flourishing" and the positivity ratio — much less evidence for a sharp discontinuity." Another study surveyed a U.S. sample of 3,032 adults, aged 25–74. Results showed 17.2 percent of adults were flourishing, while 56.6 percent were moderately mentally healthy. Some common characteristics of a flourishing adult included: educated, older, married and wealthy. The study findings suggest there is room for adults to improve as less than 20 percent of Americans are living a flourishing life. (Keyes, 2002). Benefits from living a flourishing life emerge from research on the effects of experiencing a high ratio of positive to negative affect. The studied benefits of positive affect are increased responsiveness, "broadened behavioral repertoires", increased instinct, and increased perception and imagination. In addition, the good feelings associated with flourishing result in improvements to immune system functioning, cardiovascular recovery, lessened effects of negative affect, and frontal brain asymmetry.
Sources: en.wikipedia.org
List of nuclides shows all radionuclides with half-life > 1 hour Hyperaccumulators table – 3 (includes organisms noted for accumulating radionuclides) Radioactivity in biology Radiometric dating Radionuclide cisternogram Uses of radioactivity in oil and gas wells
===== Meglitinide ===== Meglitinides are similar to sulfonylureas, as they bind to beta cells in the pancreas, but differ by the site of binding to the intended receptor and the drugs' affinities to the receptor. As a result, they have a shorter duration of action compared to sulfonylureas and require higher blood glucose levels to begin to secrete insulin. Both meglitinides, known as nateglinide and repanglinide, are sold in formulations combined with metformin. A repaglinide/metformin combination is sold as Prandimet, or as its generic equivalent.
== Mobile corps == Mobile corps (Chinese: 机动总队; pinyin: jīdòng zǒngduì), often mistranslated as "Contingents" are large formations without fixed areas of responsibility. Two were created after the 2018 reforms; most of the subordinate units came from the 14 disbanded mobile divisions. Mobile corps are corps leader grade formations commanded by major generals. The mobile corps are mainly responsible for dealing with terrorism, violent crime, riots, and public security threats.
=== Academic Health Center and UC Health (1980s-Present) === The medical school and health colleges had been referred to as the "University of Cincinnati Medical Center" from the early 1980s until 2005. In 2000 a fourth College, the College of Allied Health Sciences joined the University of Cincinnati Medical Center. In 2005, the name was changed from the University of Cincinnati Medical Center to the University of Cincinnati Academic Health Center. In 2010, the Academic Health Center (AHC) became part of the newly formed UC Health organization. UC Health was formed after the dissolution of the Health Alliance of Greater Cincinnati, which had operated the University of Cincinnati Medical Center from 1994 to 2010 and also operated West Chester Hospital starting in 2009. The 2010 dissolution of the alliance left the university with 100% ownership so the alliance was renamed to UC Health and placed under a parent company named UC Healthcare System.
Sources: en.wikipedia.org
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.
The precursor, prothymosin alpha, is encoded by the PTMA gene in humans. The 28-residue peptide corresponds to the N-terminal segment released from that larger protein.
It is produced as a fragment of prothymosin alpha and is present in many tissues. Circulating concentrations are low, which makes routine measurement difficult.
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。