lyophilised powder is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-08-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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.
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.
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.
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.
==== Orientation ==== Most often, a burial will be oriented to a specific direction for religious purposes, as are the case for persons of the Abrahamic faiths. Standard Jewish burials are made supine east-west, with the head at the western end of the grave, in order to face Jerusalem. In other cases, the body may be buried on a north-south axis, or, simply facing towards the exit of the cemetery or burial grounds. This is done in order to facilitate the return to Israel foretold of all those who are resurrected at the end of time following the coming of the Messiah. Historically, Christian burials followed similar principles, where the body was placed east-west, to mirror the layout of Christian churches, which were themselves oriented as such for much the same reason; to view the coming of Christ on Judgment day (Eschaton). In many Christian traditions, ordained clergy are traditionally buried in the opposite orientation, and their coffins carried likewise, so that at the General Resurrection they may rise facing, and ready to minister to, their people. In an Islamic funeral, the grave should be aligned perpendicular to the Qibla (the direction to the Kaaba in Mecca) with the face turned to the right along the Qibla.
=== Hemoglobin A1c === Hemoglobin A1c is a measure of the percent of red blood cells that are glycated, or have a glucose molecule attached. This can be used as an indicator of blood glucose level over a longer period of time and is often used to diagnose prediabetes as well as diabetes. HbA1c may not accurately represent blood glucose levels and should not be used in certain medical conditions such as iron-deficiency anemia, Vitamin B12 and folate deficiency, pregnancy, hemolytic anemia, an enlarged spleen, and end-stage kidney failure.
=== Ion exchange === Chelating agents, natural zeolite, activated carbon, ion exchange resins, and liquid organics impregnated with chelating agents are all used to exchange cations or anions with the solution.
=== Cardiogenesis === Development of heart is involved in several rounds of EMT and MET. While development splanchnopleure undergo EMT and produce endothelial progenitors, these then form the endocardium through MET. Pericardium is formed by sinus venosus mesenchymal cells that undergo MET. Quite similar processes occur also while regeneration in the injured heart. Injured pericardium undergoes EMT and is transformed into adipocytes or myofibroblasts which induce arrhythmia and scars. MET than leads to the formation of vascular and epithelial progenitors that can differentiate into vasculogenic cells which lead to regeneration of heart injury.
== Functions == The various functions of the liver are carried out by the liver cells or hepatocytes. The liver is thought to be responsible for up to 500 separate functions, usually in combination with other systems and organs. Currently, no artificial organ or device is capable of reproducing all the functions of the liver. Some functions can be carried out by liver dialysis, an experimental treatment for liver failure. The liver also accounts for about 20% of resting total body oxygen consumption.
Sources: en.wikipedia.org
This convinced Macleod to divert the whole laboratory to insulin research and to bring in the biochemist James Collip to help with purifying the extract. The first human clinical trial was unsuccessful. Banting was insufficiently qualified to participate and felt sidelined. By the winter of 1922, he was certain that all Macleod's colleagues were conspiring against him. There was a reported physical altercation between Banting and Collip, as Banting saw Collip's breakthrough on alcohol purification as a threat, while Collip was reluctant to share the details. Collip threatened to leave because of the strained atmosphere but the encouragement of others who saw the potential of their research prevented escalation of the conflict. In January 1922, the team performed the first successful clinical trial, on 13-year-old Leonard Thompson, and it was soon followed by others. Although all the team members were listed as co-authors of their publications, Banting still felt overlooked, because Macleod took over the coordination of clinical trials and the acquisition of larger amounts of extract. Macleod's presentation at a meeting of the Association of American Physicians in Washington, D.C., on 3 May 1922 received a standing ovation, but Banting and Best refused to participate in protest. At that time, demonstrations of the method's efficiency drew huge public interest, because the effect on patients, especially children, who until then were bound to die, seemed almost miraculous. The pharmaceutical company Eli Lilly & Co.
On 12 December 1994, the 2nd Battalion (Airborne), 505th Infantry, with the 2nd Platoon of Company C, 307th Engineer Battalion, deployed as part of Operations Safe Haven and Safe Passage. The battalion deployed from Fort Bragg "to restore order" against what American officials termed "Cuban refugees" who had attacked and injured a number of Air Force personnel and one marine while protesting their detainment at Empire Range along the Panama Canal. The battalion participated in the safeguarding of the Cuban refugees, a camp cordon and reorganization, and the active patrolling in and around the refugee camps in and around the Panamanian jungle along the Panama canal for two months. General Engineering support in the area of camp establishment/improvement operations was provided by the Sappers of the habitually associated Task Force Panther Engineer platoon, 2/C-307th. Task Force Panther was commanded by LTC Lloyd J. Austin III, who was later the first African American General to commander of US Central Command and US Secretary of Defense. This support included the planning of camp power requirements, pouring of 78 concrete pads, three-foot bridges, a set of "mock doors" for airborne pre-jump training, and a system of decks for the muddy camp. During the deployment, the paratroopers experienced a 92 °F (33 °C) Christmas Day. They returned to Fort Bragg on 14 February 1995.
Scientific investigation has not found any histological or physiological evidence for traditional Chinese concepts such as qi, meridians, and acupuncture points. It is a generally held belief within the acupuncture community that acupuncture points and meridians structures are special conduits for electrical signals but no research has established any consistent anatomical structure or function for either acupuncture points or meridians. The scientific evidence for the anatomical existence of either meridians or acupuncture points is not compelling. Stephen Barrett of Quackwatch writes that, "TCM theory and practice are not based upon the body of knowledge related to health, disease, and health care that has been widely accepted by the scientific community. TCM practitioners disagree among themselves about how to diagnose patients and which treatments should go with which diagnoses. Even if they could agree, the TCM theories are so nebulous that no amount of scientific study will enable TCM to offer rational care."
=== Sagan's finer classification === In 1973, Carl Sagan discovered Kardashev's work on the classification of civilizations. He found that the differences between the types Kardashev identified were so great that they did not allow for the best possible modeling of the evolution of civilizations. Consequently, Sagan proposed a more refined classification, still based on Kardashev's types, but integrating intermediate levels using the following logarithmic interpolation formula:
Chemical fixatives are used to preserve and maintain the structure of tissues and cells; fixation also hardens tissues which aids in cutting the thin sections of tissue needed for observation under the microscope. Fixatives generally preserve tissues (and cells) by irreversibly cross-linking proteins. The most widely used fixative for light microscopy is 10% neutral buffered formalin, or NBF (4% formaldehyde in phosphate buffered saline). For electron microscopy, the most commonly used fixative is glutaraldehyde, usually as a 2.5% solution in phosphate buffered saline. Other fixatives used for electron microscopy are osmium tetroxide or uranyl acetate. The main action of these aldehyde fixatives is to cross-link amino groups in proteins through the formation of methylene bridges (−CH2−), in the case of formaldehyde, or by C5H10 cross-links in the case of glutaraldehyde. This process, while preserving the structural integrity of the cells and tissue can damage the biological functionality of proteins, particularly enzymes. Formalin fixation leads to degradation of mRNA, miRNA, and DNA as well as denaturation and modification of proteins in tissues. However, extraction and analysis of nucleic acids and proteins from formalin-fixed, paraffin-embedded tissues is possible using appropriate protocols.
Sources: en.wikipedia.org
The beans, which are sterile within their pods, and their surrounding pulp are removed from the pods and placed in piles or bins to ferment. Micro-organisms, present naturally in the environment, ferment the seeds. Yeasts produce ethanol, lactic acid bacteria produce lactic acid, and acetic acid bacteria produce acetic acid. The fermentation process, which takes up to seven days, produces several flavor precursors, that eventually provide the chocolate taste. After fermentation, the beans are dried to prevent mold growth. Where the weather permits it, this is done by spreading the beans out in the sun for five to seven days. The dried beans are then transported to a chocolate manufacturing facility. The beans are cleaned (removing twigs, stones, and other debris), roasted, and graded. Next, the shell of each bean is removed to extract the nib.
For use topically on the skin, eye, and mucous membranes. Topical corticosteroids are divided in potency classes I to IV in most countries (A to D in Japan). Seven categories are used in the United States to determine the level of potency of any given topical corticosteroid.
== Malignant neoplasm of respiratory and intrathoracic organs (160–165) == 160 Malignant neoplasm of nasal cavities, middle ear, and accessory sinuses 161 Malignant neoplasm of larynx 162 Malignant neoplasm of trachea, bronchus, and lung 162.0 Trachea 162.2 Main bronchus 162.3 Upper lobe, bronchus or lung 162.4 Middle lobe, bronchus or lung 162.5 Lower lobe, bronchus or lung 162.8 Other parts of bronchus or lung 162.9 Bronchus and lung, unspecified 163 Malignant neoplasm of pleura 164 Malignant neoplasm of thymus, heart, and mediastinum 165 Malignant neoplasm of other and ill-defined sites within the respiratory system and intrathoracic organs
Social determinants such as neighborhood disadvantage, immigration status, lack of social support, social isolation, and access to health services play an important role in myocardial infarction risk and survival. Studies have shown that low socioeconomic status is associated with an increased risk of poorer survival. There are well-documented disparities in myocardial infarction survival by socioeconomic status, race, education, and census-tract-level poverty. Race: In the U.S. African Americans have a greater burden of myocardial infarction and other cardiovascular events. On a population level, there is a higher overall prevalence of risk factors that are unrecognized and therefore not treated, which places these individuals at a greater likelihood of experiencing adverse outcomes and therefore potentially higher morbidity and mortality. Similarly, South Asians (including South Asians that have migrated to other countries around the world) experience higher rates of acute myocardial infarctions at younger ages, which can be largely explained by a higher prevalence of risk factors at younger ages. Socioeconomic status: Among individuals who live in the low-socioeconomic (SES) areas, which is close to 25% of the US population, myocardial infarctions (MIs) occurred twice as often compared with people who lived in higher SES areas.
XXXXVIII Panzer Corps (General of Panzer Troops Rudolf Veiel): 14th Panzer Division, 29th Motorized Division, (24th Panzer Division from 6th Army on 14 Aug) IV Army Corps (General of Infantry Viktor von Schwedler): 94th Infantry Division, 371st Infantry Division, (297th Infantry-Division from 6th Army on 14 Aug) Romanian VI Army Corps (Lieutenant General Corneliu Dragalina): Romanian 1st Infantry Division, 2nd Infantry Division, 4th Infantry Division, 20th Infantry Division Army Group B's objective was to anchor itself on the Volga while Army Group A drove into the oil fields of the Caucasus. The 4th Panzer Army approached Stalingrad from the south while the 6th Army approached it from the west. Their aim was to meet up at Stalingrad and encircle the Soviet 62nd and 64th armies outside the city. The 6th Army was faced by a strong counterattack by the Soviet forces and failed to meet up with the 4th Panzer Army for three crucial days, allowing the two Soviet armies to withdraw into Stalingrad. The 4th Panzer Army guarded the outside perimeter of Stalingrad while the 6th Army was engaged in the battle to capture the city. For over two months, the 6th Army was embroiled in vicious fighting in the city; though it was able to take over 90% of the city, it was unable to destroy the last pockets of resistance. On 19 November 1942, the Red Army launched Operation Uranus, a counter-offensive which encircled the entire 6th Army and the 24th Panzer Division of the 4th Panzer Army. The 4th Panzer Army tried and failed to break the encirclement of Stalingrad in Operation Winter Storm.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。