The short version of single-use aliquot fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-26. Anything still debated is marked as such rather than presented as settled.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
=== International agencies === Jorgen Schlundt, head of food safety at the WHO criticised China's food-safety system for being "disjointed", saying that "poor communications between ministries and agencies may have prolonged the outbreak of melamine poisoning."
== Episode 3: The Wisdom of the Crowd == Willie Reyes is a 46 year old Army Veteran who is slowly losing his memories as a result of frequent seizures. Willie’s wife recounts the first time he had a seizure when he was 44 and he just fell to the floor one day without any explanation. Since the first seizure, he has developed multiple brain lesions, progressive memory loss, hearing loss, and violent/emotional mood swings. Willie says that because of his memory loss he forgets a lot of things and constantly repeats himself, making him feel like a child. His biggest fear is waking up one day and completely forgetting about his family. His daughter reveals that, recently, he's been starting to forget major memories from her childhood, such as her birth. Dr. Lisa Sanders took a look at Willie’s MRI scans and noted a huge lesion at the base of his brain with finger-like deterioration rooting up from it. She has a theory that the deterioration reaching the memory region of his brain could be the reason for his memory loss and mood swings. His wife states that in June 2019, he had a biopsy done with a piece of brain matter and the results came back as having unspecified inflammation. Dr. Sanders says that one of the biggest reasons that his condition is hard to diagnose is because it has very similar symptoms to a lot of common brain disorders, with no response to steroids. Dr. Lisa Sanders took out to publish Willie’s story and awaited the response with a possible diagnosis. Dr.
=== Oath of Allegiance === As with all dominions, provision was made for an Oath of Allegiance. Within dominions, such oaths were taken by parliamentarians personally towards the monarch. The Irish Oath of Allegiance was fundamentally different. It had two elements; the first, an oath to the Free State, as by law established, the second part a promise of fidelity, to His Majesty, King George V, his heirs and successors. That second fidelity element, however, was qualified in two ways. It was to the king in Ireland, not specifically to the king of the United Kingdom. Secondly, it was to the king explicitly in his role as part of the Treaty settlement, not in terms of pre-1922 British rule. The Oath itself came from a combination of three sources, and was largely the work of Michael Collins in the Treaty negotiations. It came in part from a draft oath suggested prior to the negotiations by President de Valera. Other sections were taken by Collins directly from the Oath of the Irish Republican Brotherhood (IRB), of which he was the secret head. In its structure, it was also partially based on the form and structure used for 'Dominion status'.
Sources: en.wikipedia.org
And uMRM to facility MRM generation after removal of isotopes and in-source fragments, all without the us of authentic standards. Siuzdak’s recent work has focused on the impact of in-source fragmentation (ISF) and other source-derived processes in mass spectrometry, demonstrating that many signals detected in LC–MS experiments can originate from ion-source–generated artifacts rather than distinct endogenous molecules. Related studies, including work by Richard Zare and colleagues on electrospray-driven chemical transformations (“in-source chemistry”), have further highlighted the potential contribution of ion-source processes to the large number of molecular features commonly observed in untargeted mass spectrometry experiments.
==== UPS European service hub ==== UPS' European service hub is located at Cologne Bonn Airport in Cologne, Germany. The Cologne Hub handles 190,000 packages an hour in the 57,000m² facility. It is the second-busiest UPS hub worldwide, in terms of daily flights serving more than 200 countries and territories around the world.
Mexico's initial neutrality in World War II was challenged by various geopolitical and economic considerations, such as its proximity to the United States, improved relations with the US as a result of President Franklin D. Roosevelt's Good Neighbor policy, and the need of the allied countries for Mexican oil for the war effort.
Periodic acid-Schiff (PAS) and immunohistochemical staining may also be used for diagnosis. Currently, there is no cure for Urbach–Wiethe disease, although there are ways to individually treat many of its symptoms. The discovery of the mutations of the ECM1 gene has opened the possibility of gene therapy or a recombinant ECM1 protein for Urbach–Wiethe disease treatment, but neither of these options are currently available. Some researchers are examining patients with Urbach–Wiethe disease to learn more about other conditions that exhibit similar neurological symptoms, such as autism.
Sources: en.wikipedia.org
=== United States === As of 2012, osteoarthritis affected 52.5 million people in the United States, approximately 50% of whom were 65 years or older. It is estimated that 80% of the population have radiographic evidence of osteoarthritis by age 65, although only 60% of those will have symptoms. The rate of osteoarthritis in the United States is forecast to be 78 million (26%) adults by 2040. In the United States, there were approximately 964,000 hospitalizations for osteoarthritis in 2011, a rate of 31 stays per 10,000 population. With an aggregate cost of $14.8 billion ($15,400 per stay), it was the second-most expensive condition seen in US hospital stays in 2011. By payer, it was the second-most costly condition billed to Medicare and private insurance.
== Effects of ingestion == Datura is considered a deliriant. Due to the potent combination of anticholinergic substances it contains, Datura intoxication typically produces the effects of anticholinergic delirium (usually involving a complete or relative inability to differentiate reality from fantasy); bizarre thoughts, hyperthermia; tachycardia; bizarre and possibly violent behavior; dry skin; dry mouth; illusions; and severe mydriasis (dilated pupils) with resultant painful photophobia that can last several days. Muscle stiffness, urinary retention, temporary paralysis, disrobing, emotional bluntness, dysphoria and confusion are often reported, and pronounced amnesia is another commonly reported effect. The psychoactive alkaloids scopolamine and atropine are also both known for their characteristic hyperactive effects and ability to cause stark and dream-like hallucinations. The onset of symptoms generally occurs around 30 to 60 minutes after ingesting the herb. These symptoms generally last from 24 to 48 hours, but have been reported in some cases to last two weeks or longer.
=== Kf === Because this constant is a measurement of hydraulic conductivity multiplied by the capillary surface area, it is almost impossible to measure physically. However, it can be determined experimentally. Methods of determining the GFR are listed in the above and below sections and it is clear from our equation that
(See also: Bangladesh–United States relations#History) Later in 1974, India conducted its first nuclear test, Smiling Buddha, which was opposed by the US, however it also concluded that the test did not violate any agreement and proceeded with a June 1974 shipment of enriched uranium for the Tarapur reactor. In the late 1970s, with the Janata Party leader Morarji Desai becoming the prime minister, India improved its relations with the US, led by Jimmy Carter, despite the latter signing an order in 1978 barring nuclear material from being exported to India due to India's non-proliferation record. Despite the return of Indira Gandhi to power in 1980, the relations between the two countries continued to improve gradually, although India did not support the United States in its role in the Soviet invasion and occupation of Afghanistan. Indian Foreign Minister P. V. Narasimha Rao expressed "grave concern" over the United States's decision to "rearm" Pakistan; the two countries were working closely together to counter the Soviets in Afghanistan. The Reagan administration led by US President Ronald Reagan provided limited assistance to India. India sounded out Washington on the purchase of a range of US defence technology, including F-5 aircraft, super computers, night vision goggles and radars. In 1984, Washington approved the supply of selected technology to India including gas turbines for naval frigates and engines for prototypes for India's light combat aircraft.
=== Christianity === In Genesis 9:4, God prohibited Noah and his sons from eating blood (see Noahide Law). This command continued to be observed by the Eastern Orthodox Church. It is also found in the Bible that when the Angel of Death came around to the Hebrew house that the first-born child would not die if the angel saw lamb's blood wiped across the doorway. At the Council of Jerusalem, the apostles prohibited certain Christians from consuming blood – this is documented in Acts 15:20 and 29. This chapter specifies a reason (especially in verses 19–21): It was to avoid offending Jews who had become Christians, because the Mosaic Law Code prohibited the practice. Christ's blood is the means for the atonement of sins. Also, "... the blood of Jesus Christ his [God] Son cleanseth us from all sin." (1 John 1:7), "... Unto him [God] that loved us, and washed us from our sins in his own blood." (Revelation 1:5), and "And they overcame him (Satan) by the blood of the Lamb [Jesus the Christ], and by the word of their testimony ..." (Revelation 12:11). Some Christian churches, including Roman Catholicism, Eastern Orthodoxy, Oriental Orthodoxy, and the Assyrian Church of the East teach that, when consecrated, the Eucharistic wine actually becomes the blood of Jesus for worshippers to drink. Thus in the consecrated wine, Jesus becomes spiritually and physically present. This teaching is rooted in the Last Supper, as written in the four gospels of the Bible, in which Jesus stated to his disciples that the bread that they ate was his body, and the wine was his blood.
Sources: en.wikipedia.org
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.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.