鼻内给药 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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。
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构,不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
== GSNO in health and disease == GSNO and NO concentrations regulate respiratory function by modulating airway tone and pro- and anti-inflammatory responses in the respiratory tract. Because NO is a labile gas and endogenous levels are difficult to manipulate, it has been proposed that exogenous GSNO could be used to regulate circulating levels of NO and NO-derived species, and GSNO could have value in patients with pulmonary diseases such as cystic fibrosis. Consistent with this therapeutic goal, a recent study showed that acute treatment with aerosolized GSNO was well tolerated by cystic fibrosis patients. SNOs in the hepatic mitochondria appear to influence proper functioning of the liver. Mitochondrial SNO-proteins inhibit Complex I of the electron transport chain; modulate mitochondrial reactive oxygen species (ROS) production; influence calcium-dependent opening of the mitochondrial permeability transition pore; promote selective importation of mitochondrial proteins; and stimulate mitochondrial fission. Altered redox balance plays a crucial role in the pathogenesis of liver diseases including steatosis, steatohepatitis, and fibrosis. The ease of reversibility and the interplay of S-nitrosating and denitrosating enzymatic reactions support the hypothesis that SNOs regulate the mitochondrion through redox mechanisms. In a study evaluating the effects on ursodeoxycholic acid (UDCA) on bile flow and cirrhosis, NO was found in bile as SNOs, primarily GSNO.
== Facial arrangements == The amino acids that make up a particular helix can be plotted on a helical wheel, a representation that illustrates the orientations of the constituent amino acids (see the article for leucine zipper for such a diagram). Often in globular proteins, as well as in specialized structures such as coiled-coils and leucine zippers, an α-helix will exhibit two "faces" – one containing predominantly hydrophobic amino acids oriented toward the interior of the protein, in the hydrophobic core, and one containing predominantly polar amino acids oriented toward the solvent-exposed surface of the protein. Changes in binding orientation also occur for facially-organized oligopeptides. This pattern is especially common in antimicrobial peptides, and many models have been devised to describe how this relates to their function. Common to many of them is that the hydrophobic face of the antimicrobial peptide forms pores in the plasma membrane after associating with the fatty chains at the membrane core.
=== Mechanisms === Food safety has been practiced for thousands of years, but with the rise of heavily industrial agriculture, the demand for food safety has steadily increased, prompting more research into the ways to achieve greater food safety. A primary mechanism that will be discussed in this article is heating of food products to kill microorganisms, as this has a millennia-long history and is still extensively used. However, more recent mechanisms have been created such as application of ultraviolet light, high pressure, electric field, cold plasma, usage of ozone, and irradiation of food.
Sources: en.wikipedia.org
Hong Kong is situated on China's southern coast, 60 km (37 mi) east of Macau and on the eastern side of the Pearl River estuary. The territory is surrounded by the South China Sea on all sides except the north, where it neighbors the Guangdong city of Shenzhen along the Sham Chun River. Its standard area is approximately 1,110 km2 (430 sq mi), though this figure reaches approximately 2,750 km2 (1,060 sq mi)2 when the open maritime area under its jurisdiction (rather than of mainland China) is included. The territory consists of Hong Kong Island, the Kowloon Peninsula, the New Territories, Lantau Island, and over 200 other islands. Of the standard area, 1,073 km2 (414 sq mi) is land and 35 km2 (14 sq mi) is inland water, such as reservoirs, rivers, and ponds. The territory's highest point is Tai Mo Shan, reaching 957 metres (3,140 ft) above sea level. Urban development is primarily concentrated on the Kowloon Peninsula, Hong Kong Island, and within various new towns throughout the New Territories. Much of this is built on reclaimed land; 70 km2 (27 sq mi) (representing 6% of the total land or about 25% of the territory's developed space) has been reclaimed from the sea.
In November 2019, Bukele's administration began trying to secure a $109 million loan from the Central American Bank for Economic Integration to fund phase three of the Territorial Control Plan. The legislature, which was controlled by ARENA and the FMLN, asked him to give them more time to evaluate the loan. On 6 February 2020, Bukele invoked Article 167 of the country's constitution and called for an emergency meeting of the Legislative Assembly to approve the loan. He called for his supporters to rally around the Legislative Assembly during the emergency meeting that was scheduled for 9 February. Although Bukele ordered 40 soldiers into the Legislative Assembly's meeting room on the day of the meeting to coerce legislators into approving the loan, a quorum was not reached and the loan was not approved. Opposition politicians described the crisis as a "self-coup", and it is known in El Salvador as "9F" or "El Bukelazo". In the 2021 legislative elections, Nuevas Ideas received a supermajority in the Legislative Assembly. On 1 May 2021, Nuevas Ideas formed a coalition government with GANA, the National Coalition Party (PCN), and the Christian Democratic Party (PDC). That day, the coalition voted to remove the five justices of the Supreme Court of Justice's constitutional court and Attorney General Raúl Melara. The justices were replaced by five of Bukele's allies, and Melara was replaced by Rodolfo Delgado.
Computer Games Magazine argued the futility of reviewing the game due to its episodic nature; as the first part of a three-part story arc, it is difficult to judge it when divorced from the final product. Game Revolution expressed disappointment at a lack of new features such as environments and weapons. During the 10th Annual Interactive Achievement Awards, the Academy of Interactive Arts & Sciences nominated Half-Life 2: Episode One for "First-Person Action Game of the Year".
Sources: en.wikipedia.org
== Effectors == Each Rho protein affects numerous proteins downstream, all of which having roles in various cell processes. Over 60 targets of the three common Rho GTPases have been found. Two molecules that directly stimulate actin polymerization are the Arp2/3 proteins and the Diaphanous-related formins.
France's "February Revolution" of 1848, was the first of the Revolutions of 1848. The events of the revolution led to the end of the 1830–1848 Orleans Monarchy and led to the creation of the Second Republic. The Revolution of 1830, part of a wave of similar regime changes across Europe, had put an end to the monarchy of the Bourbon Restoration and installed a more liberal constitutional monarchy under the Orleans dynasty governed predominantly by Guizot's conservative-liberal center-right and Thiers' progressive-liberal center-left. But to the left of the dynastic parties, the monarchy was criticized by Republicans (a mixture of Radicals and socialists) for being insufficiently democratic: its electoral system was based on a narrow, privileged electorate of property owners and therefore excluded workers. During the 1840s several petitions requesting electoral reform (universal manhood suffrage) had been issued by the National Guard but had been rejected by both of the main dynastic parties. Political meetings dedicated to this issue were banned by the government, and electoral reformers therefore bypassed the ban by holding a series of 'banquets' (1847–1848), events where the political debate was disguised as dinner speeches. This movement began overseen by Odilon Barrot's moderate center-left liberal critics of Guizot's conservative government but took on a life of its own after 1846 when the economic crisis encouraged ordinary workers to demand a say over the government.
Homeware retailer Wilko files a notice of intention to call in administrators after failing to secure a buyer, putting 12,000 jobs at risk. Butterfly Conservation reports a four-fold increase in red admiral sightings compared to the previous year, likely a result of higher temperatures in the UK. 4 August Around 4,000 scouts from the UK attending the World Jamboree in South Korea are to be moved to hotels due to the ongoing 2023 Asia heat wave. A royal spokesman confirms there will be no official public events to mark the first anniversary of the death of Elizabeth II. The mother and stepfather of Jacob Crouch, a 10-month-old baby who died at his Derbyshire home in 2020, are found guilty of causing him severe injuries leading to death. The mother, 33-year-old Gemma Barton, is acquitted of murder, but found guilty of causing or allowing the death of a child, as well as child cruelty, and is sentenced to 10 years in prison. Stepfather Craig Crouch is found guilty of murder and receives a minimum term of 28 years in prison. Storm Antoni hits the UK, the first Met Office-named storm of the year, with forecasters warning of "unseasonably" strong winds that could pose a danger to life over the weekend. A top wind gust of 78 mph is recorded at Berry Head in Devon, which is considered a potential record for the time of year. The biggest NHS privatisation since the Blair years is announced, with eight new community diagnostic centres (CDCs) being planned in a bid to cut record-high waiting lists. A further five NHS-run CDCs are also announced.
Sources: en.wikipedia.org
不存在。它是依据 ACTH 的一段序列人工设计的分子,天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号,而非天然物质名。
Semax 对应 ACTH 第 4 至第 10 位的片段,并在两端做了替换与延长,使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物,需要医生开具处方。多数其他国家把它当作研究化合物,不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.