The short version of neurotrophic factor fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-14 and is reviewed periodically as new material appears.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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。
==== Laser-assisted bioprinting ==== In a 2012 study, Koch et al. focused on whether Laser-assisted BioPrinting (LaBP) can be used to build multicellular 3D patterns in natural matrix, and whether the generated constructs are functioning and forming tissue. LaBP arranges small volumes of living cell suspensions in set high-resolution patterns. The investigation was successful, the researchers foresee that "generated tissue constructs might be used for in vivo testing by implanting them into animal models" (14). As of this study, only human skin tissue has been synthesized, though researchers project that "by integrating further cell types (e.g. melanocytes, Schwann cells, hair follicle cells) into the printed cell construct, the behavior of these cells in a 3D in vitro microenvironment similar to their natural one can be analyzed", which is useful for drug discovery and toxicology studies.
== Machu Picchu == In 1450, Machu Picchu was constructed. This date was determined and based on the Carbon 14 test results. The famous lost Inca city is an architectural remnant of a society whose understanding of civil and hydraulic engineering was advanced. Today, it is famously known for its remarkable preservation as well as the beauty of the building's architecture. The site is located 120 km northwest of Cuzco in the Urubamba river valley, Peru. At 2560 m above sea level, sitting atop a mountain, the city planners had to consider the steep slopes of the site as well as the humid and rainy climate. The Inca people built this site atop a hill which was terraced (most likely for agricultural purposes). In addition to terraces, Machu Picchu is composed of two additional basic architectural elements; elite residential compounds and religious structures. The site is full of staircases and sculpted rock, which were also important to their architecture and engineering practices.
Guiry, Michael; Guiry, Wendy. "AlgaeBase". – a database of all algal names including images, nomenclature, taxonomy, distribution, bibliography, uses, extracts "Algae – Cell Centered Database". CCDb.UCSD.edu. San Diego: University of California. Anderson, Don; Keafer, Bruce; Kleindinst, Judy; Shaughnessy, Katie; Joyce, Katherine; Fino, Danielle; Shepherd, Adam (2007). "Harmful Algae". US National Office for Harmful Algal Blooms. Archived from the original on 5 December 2008. Retrieved 19 December 2008. "About Algae". NMH.ac.uk. Natural History Museum, United Kingdom.
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary gland. Synthetic analogues of α-MSH, such as afamelanotide (melanotan I; Scenesse), melanotan II, and bremelanotide (PT-141), have been developed and researched.
Sources: en.wikipedia.org
SIMS is a mass spectrometry method to measure small-scale elemental and isotopic variations of samples. Its ability to measure in spots with a narrow diameter (10–40 μm) makes it a useful tool to date small (<100 μm) mineral grains and individual domains within a single crystal. SIMS can achieve a precision of ~3%. Sensitive high-resolution ion microprobe (SHRIMP) is widely regarded as a powerful tool among SIMS. SIMS analyzes the mineral surface (a few μm) composition by sputtering the surface with a focused primary ion beam under vacuum. The secondary ions liberated from the mineral are accelerated, measured and analyzed in the mass spectrometer. Sample are analysed in rotation with a standard of known elemental or isotopic ratios in order to determine the ratios in the sample for dating.
== History == EcPLA was first described in the scientific literature by a team that included Adam Halberstadt, Alexander Stratford, Jason Wallach, and David E. Nichols in 2019. It was developed by Lizard Labs. The drug was encountered online as a novel designer drug in around 2020 and became more widely available in early 2022.
=== Non-medical use === Enobosarm and other SARMs are sold as designer drugs by black-market vendors on the Internet. These agents have increasingly become used by the general public as "gym supplements" such as pre-workout or lifestyle drugs, rather than as an aid to performance in athletic or bodybuilding competitions. In one survey, 2.7% of young male gym users in the Netherlands reported using SARMs. In addition, a 2018 analysis of a fatberg from a sewer in central London showed enobosarm to be the most abundant "pharmaceutical drug" detected, and was present at higher concentration than recreational drugs such as MDMA and cocaine. While this isolated result may not be representative of overall levels of use, for enobosarm to be detectable in sewer deposits reflects significant levels of enobosarm use in the area close to where the sample was collected. Doses of enobosarm sold online and used non-medically are often many times higher than those assessed in clinical trials. Aside from enobosarm, the other most commonly used SARMs include vosilasarm (RAD140; "testolone"), LGD-4033 (VK5211; "ligandrol"), and andarine (GTx-007; S-4). Many products sold online that are purported to be enobosarm either contain none or contain other unrelated substances, and doses are also frequently not as labeled. Social media has played an important role in facilitating the widespread non-medical use of SARMs.
The human body's rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, the extent to which the bone marrow is producing new red blood cells, the concentration of hemoglobin in the blood, and the oxygen content of the blood. The body also absorbs less iron during times of inflammation, in order to deprive bacteria of iron. Recent discoveries demonstrate that hepcidin regulation of ferroportin is responsible for the syndrome of anemia of chronic disease.
He cut the spending proposal he sent to Congress to include funding for only the Space Shuttle, with perhaps an option to pursue the Earth orbital space station for the foreseeable future. AAP planners decided the Earth orbital workshop could be accomplished more efficiently by prefabricating it on the ground and launching it with a single Saturn V, which immediately eliminated Apollo 20. Budget cuts soon led NASA to cut Apollo 18 and 19 as well. Apollo 13 had to abort its lunar landing in April 1970 due to an in-flight spacecraft failure but returned its crew safely to Earth. The Apollo program made its final lunar landing in December 1972; the two unused Saturn Vs were used as outdoor visitor displays and allowed to deteriorate due to the effects of weathering. The USSR continued trying to develop its N1 rocket, after two more launch failures in 1971 and 1972, finally canceling it in May 1974, without achieving a single successful uncrewed test flight.
Sources: en.wikipedia.org
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.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.