RP-HPLC comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-10-11. Numbers and descriptions here follow the published literature rather than marketing material.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
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.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
A clinical study that includes some, but not all, of the eligible patients identified by the researchers during the study registration period. This type of study does not usually have a control group. (NCI) Non-inferiority trial
=== In-universe marketing === By mid-2021, Amazon created Vought International account across social media platforms such as YouTube, Facebook, Instagram, Twitter, and TikTok as part of their strategy for an innovative viral marketing campaign of The Boys. Most of the published posts are faux news, music videos, announcements, commercials, and propaganda regarding Vought and the Seven with many of the commentaries being written like if it were from the people that actually lived in the fictional world. Due to the satirical nature of the series, the marketing campaign approach is intended to touch into the "corporate greed and corruption and how celebrity is weaponized to mask accountability", while some of the posts also portray the in-universe consequences of the events occurred through the series, intending to make critique towards capitalism as well as the social and political issues surrounding America in modern times, while also making parodies of not only the superhero industry but also the studios behind it such as Disney. Wanting to satirize the pop culture and make a reflection over the real-world issues, Amazon opted to get a meta-approach and character-driven marketing campaign for the series to make the audience question over what is real or not and ensure the fans become immersed on the series themes and conflicts with the characters, leading to weekly discussions between them during the third season's run and attract global attention all around the globe.
=== Edible insects for industrialized mass production === To increase consumer interest in Western markets such as Europe and North America, insects have been processed into a non‐recognizable form, such as powders or flour. Policymakers, academics, as well as large-scale insect food producers such as Entomofarms in Canada, Aspire Food Group in the United States, Protifarm and Protix in the Netherlands, and Bühler Group in Switzerland, focus on seven insect species suitable for human consumption as well as industrialized mass production:
Sources: en.wikipedia.org
=== Wound Healing === Recent attention has been drawn to the remarkable wound-healing capabilities and excellent biocompatibility of keratin derived from human hair. While recombinant keratin proteins produced via recombinant DNA technology offer higher purity compared to extracted keratin, their wound-healing properties have remained unclear. Two recombinant trichocyte keratins—human type I hair keratin 37 and human type II hair keratin 81—were expressed using a bacterial expression system and subsequently forming recombinant keratin nanoparticles (RKNPs) through ultrasonic dispersion. It has been revealed that RKNPs significantly boosted cell proliferation and migration in laboratory settings. Moreover, when applied to dermal wounds in vivo, RKNPs facilitated improved wound healing, leading to enhanced epithelialization, vascularization, collagen deposition, and remodeling. Importantly, tests for in vivo biocompatibility showed no signs of systemic toxicity. RKNPs have potential as a promising approach for advancing wound healing and suggests new avenues for developing keratin-based biomaterials.
=== Recommended dietary intake === The WHO recommends that both adults and children reduce the intake of free sugars to less than 10% of total energy intake. "Free sugars" include monosaccharides and disaccharides added to foods, and sugars found in fruit juice and concentrates, as well as in honey and syrups. On 20 May 2016, the United States Food and Drug Administration announced changes to the Nutrition Facts panel displayed on all foods, to be effective by July 2018. New to the panel is a requirement to list "added sugars" by weight and as a percentage of Daily Value (DV). For vitamins and minerals, the intent of DVs is to indicate how much should be consumed. For added sugars, the guidance is that 100% DV should not be exceeded. 100% DV is defined as 50 grams. For a person consuming 2000 calories a day, 50 grams is equal to 200 calories and thus 10% of total calories – the same guidance as the WHO. To put this in context, most 12-US-fluid-ounce (355 ml) cans of soda contain 39 grams of sugar. In the United States, a government survey on food consumption in 2013–14 reported that, for men and women aged 20 and older, the average total sugar intakes – naturally occurring in foods and added – were, respectively, 125 and 99 grams per day. The American Heart Association recommends even lower daily consumption of added sugars: 36 grams for men and 25 grams for women.
9 September – Police in the Pakistani city of Jhelum say they have detained ten relatives of Urfan Sharif, the father of Sara Sharif, for questioning. 10 September – Nine vehicles are damaged when a privately owned military truck is driven through a police roadblock at Norton Fitzwarren, near Taunton, Somerset. A man is subsequently charged over the incident. 11 September – England's Autumn 2023 flu vaccination and COVID-19 booster programme begins, having been brought forward from October due to the BA.2.86 variant. The grandfather of Sara Sharif tells BBC News that five children who travelled to Pakistan with the dead girl's father have been taken by police. A judge subsequently rules that the children should be sent to a government childcare facility. Transport for London bans an advert for an artisan cheese after the product is deemed to be too unhealthy. 12 September – An inquest into the death of Melissa Kerr, a 31-year-old woman from Gorleston, Norfolk, who died after undergoing buttocks enlargement surgery at a private clinic in Turkey in 2019, concludes she was not given enough information concerning the risks. 13 September – Three adults who police want to speak to about the death of Sara Sharif return to the UK from Pakistan, and are arrested on suspicion of murder. The Independent Office for Police Conduct is to investigate Greater Manchester Police over its handling of the wrongful conviction of Andrew Malkinson.
1909: Alice Wilson became the first female geologist hired by the Geological Survey of Canada. She is widely credited as being the first Canadian female geologist. 1909: Danish physicist Kirstine Meyer became the first Danish woman to receive a doctorate degree in natural sciences. She wrote her dissertation on the topic of "the development of the temperature concept" within the history of physics.
Sources: en.wikipedia.org
The submucosa consists of a dense and irregular layer of connective tissue with blood vessels, lymphatics, and nerves branching into the mucosa and muscular layer. It contains the submucous plexus, and enteric nervous plexus, situated on the inner surface of the muscular layer.
It is capable of assuming more than one conformation. At least one of the conformations creates a channel through the membrane that is permeable to specific types of ions. The transition between conformations is influenced by the membrane potential. Thus, a voltage-gated ion channel tends to be open for some values of the membrane potential, and closed for others. In most cases, however, the relationship between membrane potential and channel state is probabilistic and involves a time delay. Ion channels switch between conformations at unpredictable times: The membrane potential determines the rate of transitions and the probability per unit time of each type of transition.
=== Politicians and administrators === Sir Abubakar Tafawa Balewa (Gere/Fulani) – Nigerian politician and the first prime minister of an independent Nigeria. Ahmadu Bello – Sardauna of Sokoto and first premier of Northern Region of Nigeria. Shehu Shagari – Turaki of Sokoto and the first elected president of Nigeria. Major-General Mohammadu Buhari – former president and former Head of State of Nigeria. Umaru Musa Yar'Adua – former president of Nigeria. Namadi Sambo - former vice president of Nigeria Aminu Kano – politician and teacher. Atiku Abubakar – former vice president of Nigeria. Muhammadu Abubakar Rimi – former governor of Kano State, politician. Rabiu Kwankwaso – former governor of Kano State, Nigeria, former minister of defence. Abdullahi Umar Ganduje – former governor of Kano State, Nigeria. Nasir Ahmad el-Rufai – former governor of Kaduna State, former minister of federal capital. Isa Yuguda - economist, former Minister of Aviation, former governor of Bauchi State. Abubakar Atiku Bagudu – former governor of Kebbi State, Senate Second Republic, Nigeria. Sule Lamido – former governor of Jigawa State, Nigeria, former minister of foreign affairs. Aliyu Magatakarda Wamakko – former governor of Sokoto State and current senator of Sokoto North. Danbaba Suntai - former governor Of Taraba State. Dikko Umar Radda - Governor of Katsina State. Gidado Idris – former secretary to the Government of The Federation. Muhammadu Dikko Yusufu - former Inspector General of Police.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.