If you have been reading about neuropeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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。
Enhanced mobility – components are described as "familiar, performance-enhancing, eat-out-of-hand" foods that require little or no preparation by the soldier. The beverages are reconstituted (CamelBak compatible) and consumed right out of the pouch. No water is needed for food preparation, only for the beverage mix. The food takes the form of pocket sandwiches to be eaten by hand. Lightweight – when compared to three Meals, Ready-to-Eat, the FSR reduces the weight and volume of one day's subsistence by approximately 50%. Characteristics – has a minimum two-year shelf life at 80 °F (27 °C) and provides an average of 2,900 calories per day. The FSR has nine meals per shipping container consisting of three each of three different menus up through 2010. Since 2011 there are 9 different meal combinations per shipping container. Meals – Each pouch contains items for a breakfast, lunch, and a dinner, although there is no requirement to consume the items in any specific order.
Chorthippus brunneus, also known as the common field grasshopper, is a species of grasshopper of the subfamily Gomphocerinae. The species is common and widespread in the Western Palearctic, and the IUCN lists it as Least Concern.
=== 2006–2016: Big Love and final roles === In 2006, Chase secured the role of Rhonda Volmer in Big Love, a critically acclaimed drama series on HBO which centered on a polygamist family in Utah led by patriarch Bill Henrickson (Bill Paxton). Chase's character, Rhonda, was introduced as the teenage child bride of the compound's ruthless prophet, Roman Grant (Harry Dean Stanton). Chase remained a recurring and main presence on the series until its conclusion in 2011, earning praise for her chilling depiction of a young woman corrupted by religious extremism. Also in 2006, Chase voiced Lilo for the final time in Leroy & Stitch, the conclusion to the Lilo & Stitch television series. In 2008, she took on the voice role of Betsy in the PBS Kids educational animated series Betsy's Kindergarten Adventures. In 2009, Chase reprised her Donnie Darko role as Samantha in the sequel S. Darko. Set seven years after the events of the original film, the narrative follows an 18-year-old Samantha on a cross-country road trip to Los Angeles, where she becomes plagued by bizarre visions and time anomalies. Unlike its predecessor, S. Darko received overwhelmingly negative reviews from critics. Having been made without the approval of (nor input from) the original film's creator, Richard Kelly, the sequel shares minimal continuity with its predecessor. During the 2010s, Chase appeared primarily in independent thriller and horror films. She played a supporting role in the drama Yellow (2012) and starred in the independent thriller Killer Crush (2015).
Homochirality is a uniformity of chirality, or handedness. Objects are chiral when they cannot be superposed on their mirror images. For example, the left and right hands of a human are approximately mirror images of each other but are not their own mirror images, so they are chiral. In chemistry, chirality is a geometric property of some compounds and ions. These compounds exist in two different chiral conformations, enantiomers, often described as the left-handed and right-handed isomers of a compound (denoted by L- (levorotatory to the left) and D- (dextrorotatory to the right), respectively, from how chiral molecules rotate plane-polarized light). The term homochiral is used to describe enantiopure samples of substances in which all the constituents are the same enantiomer. Enantiomers have the same chemical properties in an achiral environment, so abiotic chemical processes typically produce racemic mixtures of chiral compounds, i.e., mixtures containing equal amounts of L- and D-isomers. However, many biologically-synthesized compounds are homochiral. For example, 19 of the 20 genetically-coded proteinogenic amino acids are left-handed, with exception of the achiral glycine, and biological sugars are right-handed. Many theories have been proposed for the "function" of homochirality in nature: it may be a form of information storage and may reduce entropy barriers in the formation of large organized molecules. It has been experimentally verified that amino acids form large aggregates in larger abundance from enantiopure samples than from racemic ones.
Sources: en.wikipedia.org
=== Legal status === Paclitaxel was approved for medical use in the European Union in 2008. In November 2023, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Naveruclif, intended for the treatment of metastatic breast cancer, metastatic adenocarcinoma of the pancreas and non-small cell lung cancer. The applicant for this medicinal product is Accord Healthcare S.L.U. Naveruclif was approved for medical use in the European Union in January 2024. In May 2024, the CHMP adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Apexelsin, intended for the treatment of metastatic breast cancer, metastatic adenocarcinoma of the pancreas and non-small cell lung cancer. The applicant for this medicinal product is WhiteOak Pharmaceutical B.V. Apexelsin was approved for medical use in the European Union in July 2024.
Herein, the electron donor NADPH is used as the reducing agent, ultimately converting the β-keto group of β-ketoacyl-ACP into the β-hydroxyl group of β-hydroxyacyl-ACP. The fifth step of fatty acid elongation is the dehydration of β-hydroxyacyl-ACP to enoyl-ACP, in a reaction catalyzed by 3-hydroxyacyl-ACP dehydratase. 3-hydroxyacyl-ACP dehydratase removes one molecule of H2O to form a double bond between the C2–C3 carbons of β-hydroxyacyl-ACP, thereby saturating the chain and producing enoyl-ACP. The sixth step of fatty acid elongation is the reduction of enoyl-ACP to butyryl-ACP, in a reaction catalyzed by enoyl-ACP reductase. Herein, enoyl-ACP reductase reduces the C2–C3 double bond of enoyl-ACP into a saturated acyl-ACP using one molecule NADPH as the electron donor. The production of butyryl-ACP thus marks the completion of the first cycle of fatty acid elongation, and the reaction sequence thereafter repeats again (condensation → reduction → dehydration → reduction). At the beginning of the second cycle, butyryl-ACP condenses with a molecule of malonyl-ACP, forming the six-carbon β-ketoacyl-ACP molecule and one molecule of CO2. The next three reactions within the second cycle (reduction → dehydration → reduction) convert the six-carbon β-ketoacyl-ACP into a six-carbon ACP molecule, which thus marks the completion of the second cycle of fatty acid elongation, and a third cycle can thereafter begin. These elongation cycles continue (x7) until a (16C) acyl-ACP molecule is formed.
== Accidents and incidents == As of August 2013, the Il-86 is known to have been involved in at least 10 incidents, including 4 hull losses with a total of 23 fatalities unrelated to passengers. During its passenger-carrying operations the Il-86 has not been involved in any fatal accident. The following are reported significant recorded safety events involving the Il-86:
macromolecule Any very large molecule composed of dozens, hundreds, or thousands of covalently bonded atoms, especially one with biological significance. Many important biomolecules, such as nucleic acids and proteins, are polymers consisting of a repeated series of smaller monomers; others such as lipids and carbohydrates may not be polymeric but are nevertheless large and complex molecules.
It thus represents an advantage over whole pancreas transplantation, which is more technically demanding and poses a risk of, for example, pancreatitis leading to organ loss. Another advantage is that patients do not require general anesthesia. Islet transplantation for type 1 diabetes (as of 2008) requires potent immunosuppression to prevent host rejection of donor islets. The islets are transplanted into a portal vein, which is then implanted in the liver. There is a risk of portal venous branch thrombosis and the low value of islet survival a few minutes after transplantation, because the vascular density at this site is after the surgery several months lower than in endogenous islets. Thus, neovascularization is key to islet survival, that is supported, for example, by VEGF produced by islets and vascular endothelial cells. However, intraportal transplantation has some other shortcomings, and so other alternative sites that would provide better microenvironment for islets implantation are being examined. Islet transplant research also focuses on islet encapsulation, CNI-free (calcineurin-inhibitor) immunosuppression, biomarkers of islet damage or islet donor shortage. An alternative source of beta cells, such insulin-producing cells derived from adult stem cells or progenitor cells would contribute to overcoming the shortage of donor organs for transplantation. The field of regenerative medicine is rapidly evolving and offers great hope for the nearest future. However, type 1 diabetes is the result of the autoimmune destruction of beta cells in the pancreas.
Sources: en.wikipedia.org
In Tunisia, the Ministry of Higher Education and Scientific Research controls public universities and guarantees admission to students who earn a Tunisian Baccalaureate. Using a state website, the students make a wish list of the universities they want to attend, with the highest-ranking students getting priority choices. Universities rank students according to the results of their baccalaureate.
== Hemocyanin == Hemocyanin is a respiratory pigment that uses copper as its oxygen-binding molecule, as opposed to iron with hemoglobin. Hemocyanin is found in both arthropods and Mollusca, however it is thought that the molecule independently evolved in both phyla. There are several other molecules that exist in arthropods and Mollusca that are similar in structure to hemocyanin but serve entirely different purposes. For example, there are copper-containing tyrosinases that play significant roles in immune defense, wound healing, and the arthropod's cuticle. Molecules similar to hemocyanin in structure are grouped in under the hemocyanin superfamily.
== Civilian airfields == A few civilian airfields, such as Clinton-Sherman Airport, were originally SAC bases. The long-length runways were maintained, as well as the Christmas tree alert structure for possible reuse by SAC forces in the event of nuclear war.
=== Etymology === The word tomato comes from the Spanish tomate, which in turn comes from the Nahuatl word tomatl [ˈtomat͡ɬ] . The specific name lycopersicum, meaning 'wolf peach', originated with Galen, who used it to denote a plant that has never been identified. Luigi Anguillara speculated in the 16th century that Galen's lycopersicum might be the tomato, and despite the impossibility of this identification, lycopersicum entered scientific use as a name for the fruit.
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.