This is a working overview of Oxidation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-31 and is reviewed periodically as new material appears.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
| Property | Value | Notes |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
Biden campaigned heavily for Democrats in the 2010 midterm elections, maintaining an attitude of optimism in the face of predictions of large-scale losses for the party. After big Republican gains in the elections and Emanuel's departure, Biden's past relationships with Republicans in Congress became more important. He led the successful administration effort to gain Senate approval for the New START treaty. In December 2010, Biden's advocacy for a middle ground, followed by his negotiations with Senate minority leader Mitch McConnell, were instrumental in producing the administration's compromise tax package that included a temporary extension of the Bush tax cuts. The package passed as the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010. Obama delegated Biden to lead negotiations with Congress during the 2011 U.S. debt ceiling crisis. Biden's relationship with McConnell brought about the Budget Control Act of 2011 that solved the crisis. Some reports suggest that Biden opposed proceeding with the May 2011 U.S. mission to kill Osama bin Laden, lest failure adversely affect Obama's reelection prospects. In 2012, Biden made the case for Obama's reelection: "Osama bin Laden is dead and General Motors is alive." Obama named Biden to head the Gun Violence Task Force, created to address the causes of school shootings and consider possible gun control measures in the aftermath of the Sandy Hook Elementary School shooting, in December 2012.
If one were to flip a fair coin five times and get heads each time, it would not be any more likely for a sixth flip to come up tails. Phrased another way, after a long and/or unlikely streak of independently random events, the probability of the next event is not influenced by the preceding events. Humans often feel that the underrepresented outcome is more likely, as if it is due to happen. Such thinking may be attributed to the mistaken belief that gambling, or even chance itself, is a fair process that can correct itself in the event of streaks.
"Controversy surrounds both the drug study itself and the FDA approval," wrote NEJM editor-at-large Richard P. Wenzel, MD in 2002. The FDA approved the drug despite the advisory committee's split vote (10 to 10) due to concerns about the validity of the claimed efficacy and safety findings on the basis of a single trial. Eli Lilly spokeswoman Judy Kay Moore insisted that the company did not mastermind the ethics task force or steer the guideline-writing process. It was only a coincidence, Moore says, that the ethics task force and the Surviving Sepsis Campaign used the same P.R. firm, Belsito and Company.
This was an unexpected finding which suggests that MeCP2 is a key transcriptional regulator with potentially dual roles in gene expression. In fact, the majority of genes that are regulated by MeCP2 appear to be activated rather than repressed. However, it remains controversial whether MeCP2 regulates these genes directly or whether these changes are secondary in nature. Further studies have shown MeCP2 may be able to bind directly to un-methylated DNA in some instances. MeCP2 has been implicated in regulation of imprinted genes and loci that include UBE3A and DLX5. Reduced expression of MECP2 in Mecp2+/- neural stem cells causes an increase in senescence, impairment of proliferative capacity and accumulation of unrepaired DNA damage. After treatment of Mecp2+/- cells with any of three different DNA damaging agents, the cells accumulated more damaged DNA and were more prone to cell death than control cells. It was concluded that reduced MECP2 expression causes reduced capacity to repair DNA and this likely contributes to neurological decline.
NASA Radioisotope Power Systems website – RTG page NASA JPL briefing, Expanding Frontiers with Radioisotope Power Systems – gives RTG information and a link to a longer presentation SpaceViews: The Cassini RTG Debate Stirling Radioisotope Generator DOE contributions – good links Idaho National Laboratory – Producer of RTGs Idaho National Laboratory MMRTG page with photo-based "virtual tour"
Sources: en.wikipedia.org
=== EU risk assessments === In 2002 the EU Scientific Committee on Veterinary Measures relating to Public Health (SCVPH) claimed that the use of beef growth hormones posed a potential health risk, and in 2003 the EU enacted Directive 2003/74/EC to amend its ban, but the US and Canada objected that the EU had not met WTO standards for scientific risk assessment. The EC claimed that the hormones remain in the tissue, specifically 17-beta estradiol. However, the EC found no clear link to health risks in humans for the other five hormones. The EC reported that high amounts of hormones had been found in areas around dense cattle lots. This increase in hormones in groundwater affected waterways and nearby wild fish. Hormone contamination of North American waterways would not, however, have any health impacts on European consumers.
Microtox is an in vitro testing system which uses bioluminescent bacteria (Allivibrio fischeri, formerly known as Vibrio fischeri) to detect toxic substances in different substrates such as water, air, soils and sediments. Allivibrio fischeri are non-pathogenic, marine, bacteria that luminesce as a natural part of their metabolism. When exposed to a toxic substance, the respiratory process of the bacteria is disrupted, reducing light output. Allivibrio fischeri have demonstrated high sensitivity across a wide variety of toxic substances. Response to toxicity is observed as a change in luminescence, which is a by-product of cellular respiration. This change can be used to calculate a percent inhibition of Allivibrio fischeri that directly correlates to toxicity.
== Signs and symptoms == Dyspnea (breathlessness) is the most common symptom associated with PAH and also usually the first symptom, with 98% of people experiencing dyspnea at the time of diagnosis. Fatigue, lightheadedness, palpitations, chest pain are also present. Late findings include near-syncope or syncope (fainting). As PAH progresses and chronically elevated pulmonary arterial pressures result in right heart failure; swelling of the legs and other areas of the body (edema), fluid buildup in the abdomen (ascites) develop as late symptoms. Findings on physical exam indicating right heart failure may be present, including a loud P2 heart sound (the sound from the pulmonic valve closing), a heart murmur indicating tricuspid regurgitation or an elevated jugular venous pressure. The WHO introduced a functional classification in PAH which is used to estimate disease severity as well as response to treatment. WHO class 1 is characterized by no limitations with usual physical activity. Class 2 involves discomfort with physical activity and mild limitations. Class 3 disease involves a marked limitation with physical activity and symptoms being present with light activities. Class 4 disease involves severe symptoms with almost any physical activity and symptoms being present at rest.
== Examples == Anaerobic exercises are high-intensity workouts completed over shorter durations, while aerobic exercises include variable-intensity workouts completed over longer durations. Some examples of anaerobic exercises include sprints, high-intensity interval training (HIIT), and strength training.
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. In clinical practice it is used to diagnose and manage cancer treatment, in cardiology and cardiac surgery, and in neurology and psychiatry. PET is a common imaging technique, a medical scintillography technique used in nuclear medicine. A radiopharmaceutical—a radioisotope attached to a drug—is injected into the body as a tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is emitted, and when the positron interacts with an ordinary electron, the two particles annihilate and two gamma rays are emitted in opposite directions. These gamma rays are detected by two gamma cameras to form a three-dimensional image. PET scanners can incorporate a computed tomography scanner (CT) and are known as PET–CT scanners. PET scan images can be reconstructed using a CT scan performed using one scanner during the same session. One of the disadvantages of a PET scanner is its high initial cost and ongoing operating costs.
Sources: en.wikipedia.org
Jonna, angry, leads Clara to place her ear onto the small hole in the pool cover and stabs her in the ear with a shard of tile. In retaliation, Clara turns on the automatic pool cleaning system, causing the girls to begin suffocating in chlorine, but she turns it off again when she realises the possible consequences and leaves. Bree reveals to Jonna that during the accident that killed their father, she purposely prevented their father from escaping, calling him a monster as he had been sexually abusing the girls during their adolescence. Meanwhile, Clara returns, having realized the error of her ways. She tries to open the pool cover but her passcode no longer works. She tells the sisters they are on their own and leaves again. Bree grows weak. Jonna succeeds in ripping the metal grill off the bottom of the pool, something Bree had previously tried and failed to do. She smashes the pool cover and they escape. Jonna gives Bree her insulin shot. Clara returns with a gun, threatening to kill the sisters as she does not want to go to prison again. However, she feels sympathetic, puts the gun down, and returns their belongings. Jonna calls the police and Clara awaits her fate, but Jonna tells her to leave and the two exchange smiles. Paramedics arrive and Jonna returns Bree's engagement ring, which Clara had taken. When Bree asks how she got it back, Jonna replies, "We killed the monster", echoing what Bree said about killing their father, and implying that the monster that was inside Clara died when Jonna showed her sympathy and forgiveness.
9 October – 2024 Conservative Party leadership election: James Cleverly is knocked out of the leadership race, leaving Kemi Badenoch and Robert Jenrick to through to the final round, with the new leader chosen in a ballot of party members. Leena Sarah Farhat, a member of Llanfairfechan Town Council, is suspended by the Liberal Democrats after sharing a social media post that appeared to celebrate the 7 October attacks. 10 October – Starmer holds talks with Ukraine president Volodymyr Zelensky in Downing Street as Zelensky seeks ongoing support for the war against Russia. Starmer chairs the inaugural meeting of the Council of the Nations and Regions in Edinburgh, bringing together the leaders of the UK's devolved nations and regional mayors. Steve Davies, a former councillor with Ceredigion County Council and Aberystwyth Town Council, is disqualified from holding public office for three years after sending unwanted love letters and gifts to a number of women. 11 October – At the Plaid Cymru Annual Conference, the party's four Westminster MPs back a motion calling for a sporting and economic boycott of Israel over the war in Gaza. 12 October – Plaid Cymru votes to adopt the motion calling for a sporting and economic boycott of Israel. 13 October – Flags are lowered to half-mast at the Scottish Parliament following the death of former First Minister Alex Salmond the previous day. MSP John Mason is expelled from the SNP after posting on Twitter that there was "no genocide" in Gaza.
The cause of the 2006 death of Alexander Litvinenko, a former Russian FSB agent who had defected to the United Kingdom in 2001, was identified to be poisoning with a lethal dose of 210Po; it was subsequently determined that the 210Po had probably been deliberately administered to him by two Russian ex-security agents, Andrey Lugovoy and Dmitry Kovtun. As such, Litvinenko's death was the first (and, to date, only) confirmed instance in which polonium's extreme toxicity has been used with malicious intent. In 2011, an allegation surfaced that the death of Palestinian leader Yasser Arafat, who died on 11 November 2004 of uncertain causes, also resulted from deliberate polonium poisoning, and in July 2012, concentrations of 210Po many times more than normal were detected in Arafat's clothes and personal belongings by the Institut de Radiophysique in Lausanne, Switzerland. Even though Arafat's symptoms were acute gastroenteritis with diarrhoea and vomiting, the institute's spokesman said that despite the tests the symptoms described in Arafat's medical reports were not consistent with 210Po poisoning, and conclusions could not be drawn. In 2013 the team found levels of polonium in Arafat's ribs and pelvis 18 to 36 times the average, even though by this point in time the amount had diminished by a factor of 2 million. Forensic scientist Dave Barclay stated, "In my opinion, it is absolutely certain that the cause of his illness was polonium poisoning. ...
In this case, the objective is the creation of chassis genomes based on necessary genes and other required DNA sequences rather than the design of metabolic or regulatory pathways based on abstract criteria.
Frank Furedi (born 1947) is a Hungarian Jewish British Canadian academic known for work on sociology of fear, education, therapy culture, paranoid parenting and sociology of knowledge; in 1970s, was member of International Socialists (IS); later formed the Revolutionary Communist Group, and then broke from that to form Revolutionary Communist Tendency, refounded as the Revolutionary Communist Party in 1978; RCP was distinguished by its contrarianism; among its positions were support for IRA and Saddam Hussein Furedi is now associated with the RCP's successor, the web site Spiked Online. Neil Gaiman fantasy writer Uri Geller (Hebrew: אורי גלר; born 20 December 1946 in British Mandate of Palestine Mandatory Palestine (now Israel), of Hungarian Jewish ancestry, is an Israeli-British illusionist, magician, television personality, self-proclaimed psychic and author of over ten books, both fiction and non-fiction. Ernest Gellner social anthropologist, scholar of nationalism and identity, of Austrian Jewish and Czech Jewish origin. Adele Geras, (née Weston; born 15 March 1944) FRSL is an English writer for young children, teens and adults. She has written more than 95 books for children, young adults, and adults.
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.