Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-12. Numbers and descriptions here follow the published literature rather than marketing material.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C37H51N9O10S | 游离碱形式 |
| 等电点 | 约 6.5 | 估算值，随缓冲体系变化 |
| 主要降解途径 | 水解与氧化 | 侧链氧化最为常见 |
| 溶液储存 | 2 至 8 摄氏度避光 | 避免反复冻融 |
| 常规分析手段 | 反相色谱与质谱联用 | 氨基酸分析辅助核对 |
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
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.
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.
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.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
In the Old Testament, Jethro was Moses' father-in-law, a Kenite shepherd and priest of Midian, sometimes called Reuel (or Raguel). In Exodus, Moses' father-in-law is initially referred to as "Reuel" (Exodus 2:18) but afterwards as "Jethro" (Exodus 3:1). He was also identified as the father of Hobab in Numbers 10:29, though Judges 4:11 identifies him as Hobab. Muslim scholars and the Druze identify Jethro with the prophet Shuayb, also said to come from Midian. For the Druze, Shuayb is considered the most important prophet, and the ancestor of all Druze. They believe he was a "hidden" and "true prophet" who communicated directly with God and then passed on that knowledge to Moses, whom they describe as a "recognised" and "revealed prophet". According to Druze belief, Moses was allowed to wed Zipporah, the daughter of Jethro, after helping save his daughters and their flock from competing herdsmen. Nabi Shuʿayb is the site recognized by Druze as the tomb of Shuʿayb. It is located at Hittin in the Lower Galilee and is the holiest shrine and most important pilgrimage site for the Druze.
The United States' Center for Drug Evaluation and Research officially recommends that drugs past their expiration date be disposed. It has been argued that this practice is wasteful, since consumers and medical facilities are encouraged to purchase fresh medication to replace their expired products, also resulting in additional profits for pharmaceutical firms.
== Personal life == Xing enjoyed collecting crafts relevant the tortoise. Xing's father Duan (Chinese: 邢端) was a member of Hanlin Academy in the Late Qing dynasty, he once studied in Japan and used to be an officer at the Beiyang government. Xing's mother, Zhang Xian (Chinese: 張嫻), was a housewife. Xing and his wife Qian Cunrou (simplified Chinese: 钱存柔; traditional Chinese: 錢存柔), a microbiologist, had two sons.
==== Insects and invertebrates ==== Most bats, especially in temperate areas, prey on insects. The diet of an insectivorous bat may span many species, including flies, mosquitos, beetles, moths, grasshoppers, crickets, termites, bees, wasps, mayflies and caddisflies. They will also eat other arthropods such as spiders, scorpions, centipedes, lobsters and shrimp. Large numbers of Mexican free-tailed bats (Tadarida brasiliensis) fly hundreds of metres above the ground in central Texas to feed on migrating moths. Species that hunt insects in flight, like the little brown bat (Myotis lucifugus) and the eastern red bat (Lasiurus borealis), may catch an insect in mid-air directly with the mouth or use their tail membranes or wings. The slow-moving brown long-eared bat (Plecotus auritus) plucks insects from vegetation, while many horseshoe bat species wait for them from their perches. Some bats may take the insect to their roost and eat it there. Arthropod-eating bats living at high latitudes have to consume prey with higher energetic value than tropical bats.
Sources: en.wikipedia.org
=== Tawing === Tawing is a method that uses alum and other aluminium salts, generally in conjunction with binders such as egg yolk, flour, or other salts. The hide is tawed by soaking in a warm potash alum and salts solution, between 20 and 30 °C (68 and 86 °F). The process increases the hide's pliability, stretchability, softness, and quality. Then, the hide is air dried (crusted) for several weeks, which allows it to stabilize. The use of alum alone for tanning rawhides is not recommended, as it shrinks the surface area of the skin, making it thicker and hard to the touch. If alum is applied to the fur, it makes the fur dull and harsh.
In particle physics and nuclear physics, the branching fraction (or branching ratio) for a decay is the fraction of particles which decay by an individual decay mode or with respect to the total number of particles which decay. It applies to either the radioactive decay of atoms or the decay of elementary particles. It is equal to the ratio of the partial decay constant of the decay mode to the overall decay constant. Sometimes a partial half-life is given, but this term is misleading; due to competing modes, it is not true that half of the particles will decay through a particular decay mode after its partial half-life. The partial half-life is merely an alternate way to specify the partial decay constant λ, the two being related through:
As minor planet discoveries are confirmed, they are given a permanent number by the IAU's Minor Planet Center (MPC), and the discoverers can then submit names for them, following the IAU's naming conventions. The list below concerns those minor planets in the specified number-range that have received names, and explains the meanings of those names. Official naming citations of newly named small Solar System bodies are approved and published in a bulletin by IAU's Working Group for Small Bodies Nomenclature (WGSBN). Before May 2021, citations were published in MPC's Minor Planet Circulars for many decades. Recent citations can also be found on the JPL Small-Body Database (SBDB). Until his death in 2016, German astronomer Lutz D. Schmadel compiled these citations into the Dictionary of Minor Planet Names (DMP) and regularly updated the collection. Based on Paul Herget's The Names of the Minor Planets, Schmadel also researched the unclear origin of numerous asteroids, most of which had been named prior to World War II. This article incorporates text from this source, which is in the public domain: SBDB New namings may only be added to this list below after official publication as the preannouncement of names is condemned. The WGSBN publishes a comprehensive guideline for the naming rules of non-cometary small Solar System bodies.
Sources: en.wikipedia.org
The Metropolitan Police apologise to Doreen Lawrence after failing to provide information about a suspect in her son's murder. Drivers at 16 train operators announce a series of one-day rolling strikes between 7 and 9 May. Co-op Live announces the postponement of its opening events starring Peter Kay as the venue is not ready. 23 April Office for National Statistics data indicates UK government borrowing was at £120.7bn in March 2024, lower than the figure for the same time the previous year, but £6.6bn higher than the government's forecasts. Five migrants including a child are reported to have died attempting to cross the English Channel in a small boat, just hours after passage of the Rwanda Bill. Sunak pledges an additional £500m to support Ukraine, on top of the £2.5bn allocated for this financial year. Sunak announces "the biggest strengthening of our national defence in a generation, to meet the challenge of an increasingly dangerous world". He confirms that defence spending will increase from 2.3% of gross domestic product (GDP) to 2.5% by 2030, meaning an extra £75bn for the military over the next six years. 24 April Four people are injured and several vehicles are damaged as a number of runaway horses – one seemingly covered in blood – escape from the Household Cavalry and gallop through central London. Three people are injured and one arrested after a stabbing incident at a school in Ammanford, Wales. Unions say that 70,000 civil service jobs will be cut in order to fund an increase in defence spending.
The importance of the TGF-β pathway was confirmed with the discovery of the similar Loeys–Dietz syndrome involving the TGFβR2 gene on chromosome 3, a receptor protein of TGF-β. Marfan syndrome has often been confused with Loeys–Dietz syndrome, because of the considerable clinical overlap between the two pathologies.
(ARP) publishers of the bodybuilding magazine Muscular Development and several other magazines. David Blechman retired in 1996, and passed the title of CEO to his son Ross, while the other sons were installed as corporate officers. He died on July 7, 2000. In 2001 Twinlab sold ARP to Steve Blechman who then resigned from Twinlab. After slumping sales in 2002, the company filed a voluntary petition for Chapter 11 reorganization with the U.S. Bankruptcy Court for the Southern District of New York in September 2003. In 2004, Twinlab Corp., Twin Laboratories Inc. and Twin Laboratories (UK) Ltd. were purchased for $65 million by IdeaSphere Inc. Ideasphere also known as ISI brands, and which also operated as Twinlab, went on to acquire other dietary supplement brands such as Metabolife, Nature's Herbs, Alvita Teas, and a publisher, Rebus LLC. In January 2014 Twinlab's CEO Tom Tolworthy announced that he would partner with Capstone Financial Group to raise $130M to conduct a management buyout of Twinlab and make other acquisitions, via an entity called Twinlab Consolidation Corporation. The transaction was completed in August 2014. In July 2018, Anthony Zolezzi, founder of Bubba Gump Shrimp Company and Pet Promise Natural Dog Food was named CEO of Twinlab, after being appointed to the Board of Directors the previous May.
Sources: en.wikipedia.org
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。
甲硫氨酸侧链含硫醚，在氧气、光照或金属离子存在时容易被氧化。氧化产物极性略增，常在色谱图上表现为主峰之前的肩峰或前伸峰。
通常建议冷藏避光，并在较短时间内使用。不存在适用于所有配方的统一期限，具体取决于浓度、缓冲体系与容器材质。
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.