Everything below concerns peptide mapping. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-10-29. Numbers and descriptions here follow the published literature rather than marketing material.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
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.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | ≥ 95 % of peak area by HPLC | Some suppliers quote 98 % or higher |
| Identity confirmation | Mass spectrometry (electrospray or MALDI) | Observed mass is compared with the calculated mass |
| Common analytical method | Reversed-phase HPLC on a C18 column | Acetonitrile and water gradients with trifluoroacetic acid |
| Primary degradation route | Oxidation of the methionine residue | Yields a sulfoxide that separates cleanly on chromatography |
| Storage of dissolved material | Aliquoted and frozen at −20 °C or below | Single-use aliquots avoid repeated temperature cycling |
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 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.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
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.
In February 2024, the Palestinian Red Crescent reported that a paramedic unit had gone missing attempting to rescue six-year-old Hind Rajab. In released audio of the emergency call, Rajab is heard telling the paramedics, "I'm so scared. Please come," with gunfire in the background immediately after the family's car had been hit by an Israeli tank. On 3 February, the media director of the Palestinian Red Crescent stated only Israeli forces knew what had happened to Hind. On 5 February, one week after the attack, Rajab's mother stated, "I have been appealing to the whole world, but no one moved a finger." Her grandfather stated, "We want to know her fate, whatever it was." On 8 February, ten days after Rajab went missing, the Palestinian Red Crescent stated, "We want answers, we want the truth, we need the painful silence to end." On 10 February 2024, Rajab was found dead along with the bodies of the two paramedics.
== Pathophysiology == SJS is a type IV hypersensitivity reaction in which a drug or its metabolite stimulates cytotoxic T cells (i.e. CD8+ T cells) and T helper cells (i.e. CD4+ T cells) to initiate autoimmune reactions that attack self tissues. In particular, it is a type IV, subtype IVc, delayed hypersensitivity reaction dependent in part on the tissue-injuring actions of natural killer cells. This contrasts with the other types of SCARs disorders, i.e., the DRESS syndrome which is a Type IV, Subtype IVb, hypersensitivity drug reaction dependent in part on the tissue-injuring actions of eosinophils and acute generalized exanthematous pustulosis which is a Type IV, subtype IVd, hypersensitivity reaction dependent in part on the tissue-injuring actions of neutrophils. Like other SCARs-inducing drugs, SJS-inducing drugs or their metabolites stimulate CD8+ T cells or CD4+ T cells to initiate autoimmune responses. Studies indicate that the mechanism by which a drug or its metabolites accomplishes this involves subverting the antigen presentation pathways of the innate immune system. The drug or metabolite covalently binds with a host protein to form a non-self, drug-related epitope. An antigen presenting cell (APC) takes up these alter proteins; digests them into small peptides; places the peptides in a groove on the human leukocyte antigen (i.e. HLA) component of their major histocompatibility complex (i.e. MHC); and presents the MHC-associated peptides to T-cell receptors on CD8+ T cells or CD4+ T cells.
==== New Zealand ==== Since April 2024, pseudoephedrine has been classified as a restricted (pharmacist-only) drug in the Misuse of Drugs Act 1975 which allows the purchase of medicines containing pseudoephedrine from a pharmacist without a prescription. Pseudoephedrine, ephedrine, and any product containing these substances, e.g. cold and flu medicines, were first classified in October 2004 as Class C Part III (partially exempted) controlled drugs, due to being the principal ingredient in methamphetamine. New Zealand Customs and police officers continued to make large interceptions of precursor substances believed to be destined for methamphetamine production. On 9 October 2009, Prime Minister John Key announced pseudoephedrine-based cold and flu tablets would become prescription-only drugs and reclassified as a class B2 drug. The law was amended by The Misuse of Drugs Amendment Bill 2010, which passed in August 2011. In November 2023, the National-led coalition government announced that the sale of cold medication containing pseudoephedrine would be allowed (as part of the coalition agreement between the National and ACT parties).
Sources: en.wikipedia.org
Thorium also forms the corresponding sulfates (for example Na2SO4·Th(SO4)2·5H2O), nitrates and thiocyanates. Salts with the general formula An2Th(NO3)6·nH2O are of coordination nature, with the coordination number of thorium equal to 12. Even easier is to produce complex salts of pentavalent and hexavalent actinides. The most stable coordination compounds of actinides – tetravalent thorium and uranium – are obtained in reactions with diketones, e.g. acetylacetone.
== Medical uses == Gliclazide is used for control of hyperglycemia in gliclazide-responsive diabetes mellitus of stable, mild, non-ketosis prone, type 2 diabetes. It is used when diabetes cannot be controlled by proper dietary management and exercise and when metformin has already been tried. National Kidney Foundation (2012 Update) claims that Gliclazide does not require dosage up titration even in end stage kidney disease.
Illarionov suggested that the plan of the General Staff apparently implied the escalation of the tensions and the South Ossetian units would have the role of the provocateurs in the first days of the hostilities. In August 2012, several South Ossetian officials told Vzglyad that the war began on 1 August 2008. Former Minister of Defence Mart Laar wrote in August 2013 that Russia was thoroughly preparing for the war and Georgia was drawn unprepared in the conflict. Russia planned that Georgian forces would be compelled to attack in South Ossetia. Georgian military initially did not plan to attack Tskhinvali. Russo-Georgian war refuted the view that Russia would not attack its neighbouring countries. Laar concluded that if Georgians had not been defending their country themselves for several days, Georgian state would no longer exist and a new government would be established.
=== Conservation === Stem cells are being explored for use in conservation efforts. Spermatogonial stem cells have been harvested from a rat and placed into a mouse host and fully mature sperm were produced with the ability to produce viable offspring. Currently research is underway to find suitable hosts for the introduction of donor spermatogonial stem cells. If this becomes a viable option for conservationists, sperm can be produced from high genetic quality individuals who die before reaching sexual maturity, preserving a line that would otherwise be lost.
Sources: en.wikipedia.org
9 August – A second Police Service of Northern Ireland data breach is revealed after it emerges a spreadsheet containing the names of 200 officers was stolen from a car in July 2023. 10 August High street bargain homeware retailer Wilko goes into administration. The move puts 12,000 jobs across 400 shops at risk. Simon Byrne, the Chief Constable of the Police Service of Northern Ireland, says he is "deeply sorry" about two "industrial scale" data breaches, but will not resign over the controversy. Coronation of Charles III and Camilla: The Royal Mint unveils a special official Coronation 50 pence coin. 11 August Data from the Office for National Statistics shows the UK economy grew by an average 0.2% between April and June 2023. This includes a better than expected increase of 0.5% for June as a result of warm weather which boosted both the construction and hospitality industries. Migrants are temporarily moved from the Bibby Stockholm after traces of the Legionella bacteria are found in the water supply. The number of migrants who have crossed the English Channel since 2018 passes 100,000. 12 August England captain Harry Kane joins German champions Bayern Munich on a four-year deal, ending his record-breaking career at Tottenham Hotspur. Six people are killed and 58 rescued by British and French coastguards after a boat carrying migrants sinks off the French coast, near Sangatte, in the English Channel. 14 August – Health Secretary Steve Barclay confirms "no-one has been harmed" following the discovery of legionella bacteria on the Bibby Stockholm.
This is a timeline of women in science, spanning from ancient history up to the 21st century. While the timeline primarily focuses on women involved with natural sciences such as astronomy, biology, chemistry, and physics, it also includes women from the social sciences (e.g. sociology, psychology), and the formal sciences (e.g. mathematics, computer science), as well as notable science educators and medical scientists. The chronological events listed in the timeline relate to both scientific achievements and gender equality within the sciences.
In Vietnamese cuisine, there are two varieties of glass noodles. The first, called bún tàu or bún tào, are made from mung bean starch, and were introduced by Chinese immigrants. The second, called miến or miến dong, are made from canna (Vietnamese: dong riềng), and were developed in Vietnam. These glass noodles are a main ingredient in the dishes: miến gà (chicken), miến lươn (eel), miến ngan (muscovy duck), and miến cua (crab). These glass noodles are sometimes confused with rice vermicelli (Vietnamese: bún) and arrowroot starch noodles (Vietnamese: arrowroot: củ dong, arrowroot starch: bột dong/bột hoàng tinh/tinh bột khoai mì).
Sources: en.wikipedia.org
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.
The methionine residue at the start of the chain is vulnerable to oxidation, producing a sulfoxide variant. Amide bonds can also hydrolyze, though more slowly under neutral conditions. Cold storage, oxygen exclusion and minimization of freeze-thaw cycles slow both processes but do not stop them.
A purity number on a certificate does not establish that a powder is the same product as a registered nasal medicine. Counter-ion content, residual solvents and peptide-related impurities may differ between the two. Independent verification is the only way to narrow that gap.
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.