If you have been reading about lyophilization and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-07. Numbers and descriptions here follow the published literature rather than marketing material.
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。
Identity and purity are normally assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities and truncation products. Mass spectrometry confirms molecular mass and detects modifications such as deamidation or oxidation. Amino acid analysis and peptide mapping provide additional sequence-level confirmation. For research material, a certificate of analysis typically reports these results together with water content and counter-ion identity, since the lyophilized powder is often supplied as an acetate or trifluoroacetate salt.
Several factors accelerate degradation: alkaline pH, elevated temperature, exposure to oxidants, and the presence of residual moisture. Deamidation of asparagine residues and oxidation of methionine are the most commonly reported degradation routes. Because the peptide lacks disulfide bonds, it does not undergo the thiol-related aggregation seen in some other biologics, but physical aggregation can still occur at high concentration. Stability data are product-specific, and extrapolating shelf life between formulations is not reliable.
| 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 |
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.
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.
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
== Other reactions == Ornithine, through the action of ornithine decarboxylase (EC 4.1.1.17), serves as the starting point for the synthesis of polyamines such as putrescine. In bacteria such as E. coli, ornithine can be synthesized from L-glutamate.
As the first woman since 1964 to win the Nobel Prize in chemistry, and the first since Dorothy Crowfoot Hodgkin, 45 years previously. She was also the fourth of eight women ever to win the Nobel Prize in chemistry. Although Yonath once remarked, “I am a scientist, not male or female. A scientist,” her 2009 award was noted as a highlight for female scientists. The Australian noted that Yonath's Nobel win was "crushing the lab's glass ceiling". Regarded as an influential Israeli scientist, Yonath helped established the first protein crystallography laboratory in Israel. In 2018, while interviewing Yonath, UNESCO noted that her scientific research has also been "key to understanding how antibiotics work". Following her death, The New York Times noted that Yonath's mapping of the ribosome led to new designs for antibiotics. Her work was noted as "boundary pushing" with it having "immediate and practical consequences" for medicine and in the "fight against infectious disease". President Isaac Herzog noted Yonath as "one of the leading researchers in the history of Israeli science". The Hindu also noted Yonath's academic impact, especially in India through her engagements in academic institutions in the country.
The Cephalopoda descended from a mollusc resembling the Monoplacophora in the Cambrian some 530 million years ago. The Coleoidea, which brought their shells inside the body, diverged from the nautiloids in the Devonian some 416 million years ago. Around 276 million years ago, during the Permian, the coleoids split into two groups, the Vampyropoda and the Decabrachia. The octopuses arose from the Muensterelloidea within the Vampyropoda in the Jurassic. The earliest octopus likely lived near the sea floor (benthic to demersal) in shallow marine environments. Octopuses consist mostly of soft tissue, and so fossils are relatively rare. As soft-bodied cephalopods, they lack the external shell of most molluscs, including other cephalopods like the nautiloids and the (extinct) Ammonoidea. They have eight limbs like other Coleoidea, but lack the extra specialised feeding appendages known as tentacles which are longer and thinner with suckers only at their club-like ends. The vampire squid (Vampyroteuthis) also lacks tentacles but has sensory filaments. The cladograms are based on Sanchez et al., 2018, who created a molecular phylogeny based on mitochondrial and nuclear DNA marker sequences. The position of the Eledonidae is from Ibáñez et al., 2020, with a similar methodology. Divergence dates are from Kröger et al., 2011 and Fuchs et al., 2019.
Although not formally a quinolone, nalidixic acid is considered the first quinolone drug. It was introduced in 1962 for treatment of urinary tract infections (UTIs) in humans. Nalidixic acid was discovered by George Lesher and coworkers in a distillate during an attempt at chloroquine synthesis. Nalidixic acid is thus considered to be the predecessor of all members of the quinolone family, including the second, third and fourth generations commonly known as fluoroquinolones. Since the introduction of nalidixic acid, more than 10,000 analogs have been synthesized, but only a handful have found their way into clinical practice. The first generation also included other quinolone drugs, such as pipemidic acid, oxolinic acid, and cinoxacin, which were introduced in the 1970s. They proved to be only marginal improvements over nalidixic acid. These drugs were widely used as a first-line treatment for many infections, including very commons ones such as acute sinusitis, acute bronchitis, and uncomplicated UTIs. Reports of serious adverse events began emerging, and the FDA first added a black-box warning to fluoroquinolones in July 2008 for the increased risk of tendinitis and tendon rupture. In February 2011, the risk of worsening symptoms for those with myasthenia gravis was added to the warning. In August 2013, the agency required updates to the labels to describe the potential for irreversible peripheral neuropathy (serious nerve damage).
Sources: en.wikipedia.org
== List of virucides == Note that many of the substances, if sold commercially, are usually combinations and mixtures with varying molecular contents. Also note that most products have a limited viricide efficacy. A specific test-protocol is applied. The lists' scope is limited. For further products refer to other lists. Other factors such as stability of the concentrate, application concentration, exposure time, timing of the solution, hydrogen ion concentration (pH value), temperature, etc. play an certain role for the effectivity of a virucide. EPA is providing a public listing called "List N"
Before showing the documents to Sports Illustrated, Exum tried to use them in a lawsuit against USOC, accusing the organization of racial discrimination and wrongful termination against him and cover-up over the failed tests. the Denver federal Court summarily dismissed his case for lack of evidence. The USOC labelled his case "baseless" as he himself was the one in charge of screening the anti-doping test program of the organization and clarifying that the athletes were cleared according to the rules. Carl Lewis broke his silence on allegations that he was the beneficiary of a drugs cover-up, admitting he had failed tests for banned substances, but claiming he was just one of "hundreds" of American athletes who were allowed to escape bans, concealed by the USOC. Lewis has acknowledged that he failed three tests during the 1988 US Olympic trials, which under international rules at the time should have prevented him from competing in the 1988 Summer Olympics. Former athletes and officials came out against the USOC cover-up. "For so many years I lived it. I knew this was going on, but there's absolutely nothing you can do as an athlete. You have to believe governing bodies are doing what they are supposed to do. And it is obvious they did not," said former American sprinter and 1984 Olympic champion, Evelyn Ashford. Exum's documents revealed that Carl Lewis had tested positive three times at the 1988 Olympics trials for minimum amounts of pseudoephedrine, ephedrine, and phenylpropanolamine, which were banned stimulants. Bronchodilators are also found in cold medication.
He added that "China's sovereignty, security, and development interests cannot be violated, and four red lines — the Taiwan question, democracy and human rights, development paths and systems, and development rights — cannot be challenged". Shortly after Xi arrived to the US on September 23, Treasury Secretary Bessent announced that the trade truce between the two countries, reached at the Busan Summit and was set to expire on November 10, would be extended until January 10, 2027. On September 24, Chinese defense ministry spokesperson Jiang Bin said that "it should be emphasized that the Taiwan question is the most important in China–US relations and maintaining peace and stability in the Taiwan Strait is the greatest common issue of the two countries and that "it is hoped that the US side will handle the Taiwan issue with extreme caution". Due to Trump's recent ban of several news outlets from the White House, most of Xi's state visit was not covered by the White House press pool. ABC World News Tonight placed the news of Xi's as the third item, with only photos and no video. CNN reported that the Chinese side had informally expressed its concerns to the United States that the boycott would affect the coverage of the visit. On September 24, the Trump administration returned the press credentials to the three media outlets, but still excluded CNN. The opening remarks of the summit meeting that day were not made public to the media as is customary, meaning the only publicly available video recording of the meeting was the segment broadcast by China Central Television.
== Controversy == Doctor's Data has proven controversial because of the four lawsuits that have been filed by people who say that the company victimized them by diagnosing them as having toxic metal poisoning based on their urinalysis tests, and then prescribing them chelation therapy. According to Patricia Callahan, the problem with these tests and the way they are interpreted is that, after administering a chelator to their patients, "Doctor's Data...compared those drug-provoked results to a reference range calculated for people who had never been given a chelation drug." In addition, they have faced considerable criticism from Stephen Barrett, who has described how provoked urine test reports are used to mislead patients. and has also written negatively about hair analysis in general, which he contends is "unscientific, economically wasteful, and probably illegal." Arthur Allen has also criticized the methodology of their urinalysis tests, saying that they "...present the results [from their urine analysis tests] in such a way that it almost guarantees a finding of "toxicity" for each child." In response to this criticism, Doctor's Data president Ted Lueken argued that "the technique can be valuable when used along with other tests and a doctor's knowledge of his patient." Doctor's Data later sued Barrett on June 18, 2010, accusing him of "...harm[ing] Doctor's Data by transmitting false, fraudulent and defamatory information about this company in a variety of ways" in his writings about the company.
The byproduct N,N'-dicyclohexylurea is mostly removed by filtration, but trace impurities can be difficult to remove. It is incompatible with traditional solid-phase peptide synthesis. DCC is a potent allergen, and repeated contact with skin increases the probability of sensitization to the compound. Clinical reports of individuals who cannot enter rooms where peptide coupling agents are used have been reported.
Sources: en.wikipedia.org
As long as the artery enlarges sufficiently to compensate for the extra thickness of the atheroma, then no narrowing ("stenosis") of the opening ("lumen") occurs. The artery expands with an egg-shaped cross-section, still with a circular opening. If the enlargement is beyond proportion to the atheroma thickness, then an aneurysm is created.
=== Osteoblasts === Osteoblasts are the major cellular component of bone. Osteoblasts arise from mesenchymal stem cells (MSC). MSC give rise to osteoblasts, adipocytes, and myocytes among other cell types. Osteoblast quantity is understood to be inversely proportional to that of marrow adipocytes which comprise marrow adipose tissue (MAT). Osteoblasts are found in large numbers in the periosteum, the thin connective tissue layer on the outside surface of bones, and in the endosteum. Normally, almost all of the bone matrix, in the air breathing vertebrates, is mineralized by the osteoblasts. Before the organic matrix is mineralized, it is called the osteoid. Osteoblasts buried in the matrix are called osteocytes. During bone formation, the surface layer of osteoblasts consists of cuboidal cells, called active osteoblasts. When the bone-forming unit is not actively synthesizing bone, the surface osteoblasts are flattened and are called inactive osteoblasts. Osteocytes remain alive and are connected by cell processes to a surface layer of osteoblasts. Osteocytes have important functions in skeletal maintenance.
=== Spondylodysplastic === Spondylodysplastic EDS (spEDS) is characterized by short stature (progressive in childhood), muscle hypotonia (ranging from severe congenital to mild later-onset), and bowing of limbs. It can be caused by variations in both copies of the B4GALT7 gene. Other cases can be caused by variations in the B3GALT6 gene. People with variations in this gene can have kyphoscoliosis, tapered fingers, osteoporosis, aortic aneurysms, and problems with the lungs. Other cases can be caused by the SLC39A13 gene. Those with variations in this gene have protuberant eyes, wrinkled palms of the hands, tapering fingers, and distal joint hypermobility.
Laidlaw stated that reasons behind the cancellation included the fact that headcrabs and zombies "were pretty much played out at the time", and that the fact that it had to take place chronologically prior to Half-Life 2: Episode Two was too creatively constraining. Footage of the project was shown in a 2020 documentary by media company Noclip titled The Untold History of Arkane.
==== Insects ==== Freeze-drying is used extensively to preserve insects for the purposes of consumption. Whole freeze-dried insects are sold as exotic pet food, bird feed, fish bait, and increasingly for human consumption. Powdered freeze-dried insects are used as a protein base in animal feeds, and in some markets, as a nutritional supplement for human use. Farmed insects are generally used for all of the aforementioned purposes versus harvesting wild insects, except in the case of grasshoppers which are often harvested out of field crops.
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。
Dry lyophilized powder tolerates short ambient exposure during handling and shipping. Long-term room-temperature storage is not recommended because moisture uptake and slow degradation can occur over months. Storage at minus twenty degrees Celsius is the common practice for extended periods.