The short version of methionine sulfoxide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-16 and is reviewed periodically as new material appears.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
| Property | Value | Notes |
|---|---|---|
| Typical purity | 95% or higher | By reversed-phase HPLC area |
| Identity method | Electrospray mass spectrometry | Confirms molecular mass |
| Purity method | Reversed-phase HPLC | Detection near 214 nm |
| Primary degradation | Methionine oxidation | Sulfoxide product, +16 Da |
| Solution storage | 2-8 °C, short term | Aliquot to avoid freeze-thaw |
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
== Named after Dyson == Dyson conjecture Dyson equation Dyson numbers Dyson operator Dyson series Dyson sphere Dyson tree Dyson's crank Dyson's eternal intelligence Dyson's transform Dyson–Maleev spin wave theory Schwinger–Dyson equation Thue–Siegel–Dyson–Roth theorem Feynman diagram, also known as Dyson graphs Wigner–Yamase–Dyson conjecture Gordon Freeman, a fictional character named after Dyson
===== MeSH D08.811.913.225 – alkyl and aryl transferases (EC 2.5) ===== MeSH D08.811.913.225.224 – cysteine synthase MeSH D08.811.913.225.300 – dihydropteroate synthase MeSH D08.811.913.225.400 – dimethylallyltranstransferase MeSH D08.811.913.225.431 – farnesyl-diphosphate farnesyltransferase MeSH D08.811.913.225.437 – farnesyltranstransferase MeSH D08.811.913.225.443 – geranylgeranyl-diphosphate geranylgeranyltransferase MeSH D08.811.913.225.450 – geranyltranstransferase MeSH D08.811.913.225.500 – glutathione transferase MeSH D08.811.913.225.500.500 – glutathione S-transferase pi MeSH D08.811.913.225.575 – hydroxymethylbilane synthase MeSH D08.811.913.225.650 – methionine adenosyltransferase MeSH D08.811.913.225.735 – 3-phosphoshikimate 1-carboxyvinyltransferase MeSH D08.811.913.225.750 – riboflavin synthase MeSH D08.811.913.225.825 – spermidine synthase MeSH D08.811.913.225.912 – spermine synthase
Gus Sackey (David Jonsson) is a new grad at Pierpoint, and one of the series' protagonists during the first two series. He is initially assigned to the Investment Banking Division (IBD) and transferred to the CPS desk after the death of his colleague Hari Dhar. Gus is openly gay and hails from an elite background, having graduated literae humaniores from both Eton College and the University of Oxford. Despite his upper-class upbringing, Gus is shown to be humble and morally principled, and feels undervalued within Pierpoint's cutthroat work culture. In series 1, Gus struggles to find a clear role after his team is dissolved and repeatedly alienates senior staff through his bluntness and frustration, including London office head Sara Dhadwal and his manager Clement Cowan. He also rekindles an affair with his former classmate Theo Tuck. On RIF day, Gus delivers a deliberately unserious presentation—beginning by reading from a note written as part of a bet—before walking out, and is not offered a permanent position. In series 2, Gus re-emerges working in politics after striking up a connection with MP Aurore Adekunle, who hires him as an aide. Gus feels fulfilled by the work—which largely involves speaking with everyday constituents about their struggles—despite his sister Sadie's objections. While working for Aurore, Gus begins a relationship with Leo Bloom, the son of hedge fund manager Jesse Bloom, and later leaks confidential government information about the approval of Amazon’s acquisition of pharmaceutical company FastAide to Harper.
A study by Kim et al. investigated the nutritional value of S. mutilans hoping to extend the application of this species from traditional medicine only. Nutritional analysis on this species found that it is high in crude protein (around 55%) and fat (around 26-30%). Essential amino acids were present, with lysine being the most common (around 3.5% of all essential amino acids), and glutamic acid being the most common nonessential amino acid present in the centipede (around 7% of all nonessential amino acids). Unsaturated fatty acids were also present, with oleic acid being the most common (around 41-48%). Mercury was found, but the concentration was below food safety limits. Pathogenic microorganisms were not found in the centipede samples. From these findings, the researchers suggested that S. mutilans has the potential to be a medicine and food ingredient.
== Post-playing career == On April 9, 2022, the Colorado Rockies hired Helton as a special assistant to the general manager, joining Vinny Castilla and Clint Hurdle in the role. They and Charlie Blackmon held that role in 2025.
Sources: en.wikipedia.org
Carroll, J. T. (1975). Ireland in the War Years 1939–1945. David and Charles. ISBN 9780844805658. Coogan, Tim Pat (1993). De Valera: Long Fellow, Long Shadow. London: Hutchinson. ISBN 9780091750305. published as Eamon de Valera: The Man Who Was Ireland (New York, 1993) Coogan, Tim Pat (1990). Michael Collins. Hutchinson. ISBN 0-09-174106-8. Corcoran, Donal. "Public policy in an emerging state: The Irish Free State 1922-25." Irish Journal of Public Policy 1.1 (2009). online Dwyer, T. Ryle (2006). Big Fellow, Long Fellow: A Joint Biography of Collins and De Valera. Gill Books. ISBN 0717140849. excerpt and text search Dwyer, T. Ryle (1982). De Valera's Finest Hour 1932–59. Fanning, Ronan. Éamon de Valera: A Will to Power (2016) Foster, R. F. Modern Ireland, 1600-1972 (1989) online Girvin, Brian. "Beyond Revisionism? Some Recent Contributions to the Study of Modern Ireland." The English Historical Review 124#506, 2009, pp. 94–107. online Gwynn, Denis. The Irish Free State, 1922-1927 (Macmillan 1928); detailed coverage.online Keown, Gerard. First of the Small Nations: The Beginnings of Irish Foreign Policy in the Inter-war Years, 1919-1932 (Oxford University Press, 2016). online Kissane, Bill. "Eamon De Valera and the Survival of Democracy in Inter-War Ireland". Journal of Contemporary History (2007). 42 (2): 213–226. online Lee, J. J. Ireland, 1912-1985: politics and society (Cambridge University Press, 1989) online. McCardle, Dorothy (January 1999). The Irish Republic. Wolfhound Press. ISBN 0-86327-712-8. O'Halpin, Eunan.
Self-assembled quantum dots nucleate spontaneously under certain conditions during molecular-beam epitaxy (MBE) and metalorganic vapour-phase epitaxy (MOVPE), when a material is grown on a substrate to which it is not lattice matched. The resulting strain leads to the formation of islands on top of a two-dimensional wetting layer. This growth mode is known as Stranski–Krastanov growth. The islands can be subsequently buried to form the quantum dot. A widely used type of quantum dots grown with this method are indium gallium arsenide (InGaAs) quantum dots in gallium arsenide (GaAs). Such quantum dots have the potential for applications in quantum cryptography (that is, single-photon sources) and quantum computation. The main limitations of this method are the cost of fabrication and the lack of control over positioning of individual dots. Despite these limitations, self-assembled InAs quantum dots grown by this method have been extensively characterized optically. Cathodoluminescence spectroscopy of individual dots revealed ultranarrow luminescence lines below 0.15 meV, providing direct experimental evidence for the discrete, delta-function-like electronic density of states predicted for zero-dimensional structures. Individual quantum dots can be created from two-dimensional electron or hole gases present in remotely doped quantum wells or semiconductor heterostructures called lateral quantum dots. The sample surface is coated with a thin layer of resist and a lateral pattern is then defined in the resist by electron-beam lithography.
In the two weeks prior to the disappearance he created a total obsession with him, he didn't leave him alone". After speaking against Dias, Silva said that he and the other witnesses were scared and did not receive police protection. In 2011, João André Mendonça that when he was giving his testimony in GNR (Republican National Guard) in 1998, Dias asked him to "not open his mouth" and that "the authorities should close the borders (...) Maybe they still have time". In 2012, Paulo Gomes, Dias' lawyer, declared that "Mister Afonso isn't talking because his freedom is on the line". In the same year Dias said that he was going to talk about what happened with Rui Pedro, but he would do it outside of the courtroom. In an interview to Grande Revista of RTP in 2012, he said that he does not talk more because of all the help he gave to authorities that only served for his prosecution thirteen years later. When questioned about Rui Pedro he answered after a long silence: "As I see it... I don't know... three weeks after another kid went missing in Famalicão. Either it was a kidnapping or he fell in a well... I don't know". Later (in 2018), he said he did not have a theory on what happened with the boy. Ricardo Sá Fernandes, Mendonça family's lawyer, stated in 2017: "I keep saying that what I would really like is for Afonso Dias to tell us what happened with Rui Pedro after they left the prostitute. But he didn't say anything in court, and continues to not reveal what I would like for him to reveal. And, I repeat, what I would really like would be for him to say what he knows."
The joint project with the GAVI alliance has shown that this is feasible with three quarters of the 1301 project counties reporting that 85% or more children received three doses of HepB vaccine. In hospitals designated as project hospitals, the percentage of newborns vaccinated within 24 hours of birth is now over 90%. However, the overall newborn vaccination rate in the region covered by the GAVI alliance/government joint project was 70%, lower than the 75% they hoped to achieve. Achieving long-term success will require "assuring no new financial barriers arise", said Julian Lob-Levyt, Executive Secretary of the GAVI Alliance. "This is one of the greatest challenges and the solution lies not just within China but with a global community mobilized to ensure access to vaccine financing for all developing nations." Home to a large population of ethnic minorities of low socioeconomic status, the Qinghai province is a remote, often neglected, rural region of China with a high prevalence of chronic hepatitis B. Since many children 5 years of age and older in Qinghai were not vaccinated against the hepatitis B virus at birth, a private-public partnership was formed between the Ping and Amy Chao Foundation, the ZeShan Foundation, the Asian Liver Center at Stanford University, the China Center for Disease Control and Prevention, the Chinese Foundation for Hepatitis Prevention and Control, and the Qinghai government.
An orphan drug is a pharmaceutical agent that is developed to treat certain rare medical conditions. An orphan drug would not be profitable to produce without government assistance, due to the small population of patients affected by the conditions. The conditions that orphan drugs are used to treat are referred to as orphan diseases. The assignment of orphan status to a disease and to drugs developed to treat it is a matter of public policy that depends on the legislation (if there is any) of the country. Designation of a drug as an orphan drug has yielded medical breakthroughs that might not otherwise have been achieved, due to the economics of drug research and development. For example, in the U.S. and the EU, it is easier to gain marketing approval for an orphan drug. There may be other financial incentives, such as an extended period of exclusivity, during which the producer has sole rights to market the drug. All are intended to encourage development of drugs which would otherwise lack sufficient profit motive to attract corporate research budgets and personnel.
Sources: en.wikipedia.org
Translatomics is the study of all open reading frames (ORFs) that are being actively translated in a cell or organism. This collection of ORFs is called the translatome. Characterizing a cell's translatome can give insight into the array of biological pathways that are active in the cell. According to the central dogma of molecular biology, the DNA in a cell is transcribed to produce RNA, which is then translated to produce a protein. Thousands of proteins are encoded in an organism's genome, and the proteins present in a cell cooperatively carry out many functions to support the life of the cell. Under various conditions, such as during stress or specific timepoints in development, the cell may require different biological pathways to be active, and therefore require a different collection of proteins. Depending on intrinsic and environmental conditions, the collection of proteins being made at one time varies. Translatomic techniques can be used to take a "snapshot" of this collection of actively translating ORFs, which can give information about which biological pathways the cell is activating under the present conditions. Usually, the ribosome profiling technique is used to acquire the translatome information. Recent advancements, including single-cell ribosome profiling, have significantly improved the resolution of these studies, allowing researchers to gain insights into translation at the level of individual cells.
== Background == Lineage Logistics is the world's largest temperature-controlled warehouse real estate investment trust (REIT), owned by Bay Grove, LLC. Entering international markets in 2017, Lineage grew into the world's largest refrigerated warehousing company with a capacity exceeding 3 billion cubic feet and acquiring more than 100 companies through the end of 2023. The warehouse is located at 1400 S. Los Palos Street and was built in 2018. A previous fire had happened at the same warehouse in 2024 but was extinguished within 48 minutes.
=== Bacteria === Many common culturable laboratory strains are deep-frozen to preserve genetically and phenotypically stable, long-term stocks. Sub-culturing and prolonged refrigerated samples may lead to loss of plasmid(s) or mutations. Common final glycerol percentages are 15, 20, and 25. From a fresh culture plate, one single colony of interest is chosen and liquid culture is made. From the liquid culture, the medium is directly mixed with an equal amount of glycerol; the colony should be checked for any defects like mutations. All antibiotics should be washed from the culture before long-term storage. Methods vary, but mixing can be done gently by inversion or rapidly by vortex and cooling can vary by either placing the cryotube directly at −50 to −95 °C, shock-freezing in liquid nitrogen or gradually cooling and then storing at −80 °C or cooler (liquid nitrogen or liquid nitrogen vapor). Recovery of bacteria can also vary, namely, if beads are stored within the tube then the few beads can be used to plate or the frozen stock can be scraped with a loop and then plated, however, since only little stock is needed the entire tube should never be completely thawed and repeated freeze-thaw should be avoided. 100% recovery is not feasible regardless of methodology.
I am born of a people who are heroes and heroines [...] Patient because history is on their side, these masses do not despair because today the weather is bad. Nor do they turn triumphalist when, tomorrow, the sun shines. [...] Whatever the circumstances they have lived through and because of that experience, they are determined to define for themselves who they are and who they should be. In April 1997, Mbeki articulated the elements that comprise the African Renaissance: social cohesion, democracy, economic rebuilding and growth, and the establishment of Africa as a significant player in geopolitical affairs. Two months later, Vusi Maviembela, an advisor to Mbeki, wrote that the African Renaissance was the "third moment" in post-colonial Africa, following decolonization and the spread of democracy across the continent in the early 1990s. Deputy President Mbeki codified his beliefs, and the reforms that would comprise them, in the "African Renaissance Statement" given August 13, 1998. In March 1998, United States President Bill Clinton visited Botswana, Ghana, Rwanda, Senegal, South Africa, and Uganda in a 12-day tour, which he proclaimed as the "beginning of a new African renaissance" following apartheid, colonialism, and the Cold War. While Clinton praised the continent's increase in democratically elected governments, news outlets countered that many African leaders operated in one-party states. The outbreak of the Eritrean–Ethiopian War in May 1998 and Second Congo War in August 1998 led to further doubts of a peaceful future.
Sources: en.wikipedia.org
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.
In solution, hydrolysis of peptide bonds and oxidation of the methionine residue are the principal concerns. Oxidation converts methionine to its sulfoxide form, shifting the mass by sixteen daltons. Both processes are slowed by cold storage and by avoiding alkaline conditions.
A certificate documents what the supplier measured on a specific lot, not how a laboratory will use the material. Independent verification of identity and purity is common practice. Acceptance criteria should be defined before a batch is ordered.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.