Everything below concerns GLP-1 analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released after nutrient intake. The molecule contains 31 amino acid residues and differs from the native sequence at several positions. A non-natural residue at position eight resists the enzyme that normally truncates the hormone, while a lysine-linked fatty diacid side chain promotes binding to serum albumin. These two modifications extend the circulating half-life from minutes to roughly one week. The peptide is produced by solid-phase synthesis followed by selective acylation, and its identity and purity are confirmed by spectrometric and chromatographic techniques.
The primary target is the GLP-1 receptor, a class B G protein-coupled receptor expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises intracellular cyclic AMP, which potentiates glucose-dependent insulin secretion and lowers glucagon release when blood glucose is elevated. Signalling in the hypothalamus and brainstem is associated with reduced appetite and slower gastric emptying. Because the insulinotropic effect depends on prevailing glucose levels, the hypoglycaemic risk of the peptide alone is described as low in most study settings. The relative contribution of peripheral and central actions remains an active research question.
Large randomised trials in adults with type 2 diabetes and in adults with obesity have reported reductions in body weight and improvements in several cardiovascular risk markers. One outcome trial found a lower incidence of major adverse cardiovascular events in participants with diabetes and established cardiovascular disease. Gastrointestinal effects such as nausea and vomiting are the most frequently reported adverse events and often diminish over time. Changes in lean body mass during weight loss are an area of ongoing investigation. Effects in adolescents and in pregnancy are less well characterised, and current labelling advises against use during pregnancy.
Semaglutide is a synthetic peptide analog of human glucagon-like peptide-1, a gut hormone released after meals. Its backbone retains the GLP-1 sequence but incorporates two substitutions that slow enzymatic breakdown by dipeptidyl peptidase-4. A short polyethylene glycol linker and a C18 fatty diacid are attached to the peptide chain, allowing the molecule to bind serum albumin and remain in circulation far longer than the native hormone. The result is a circulating half-life measured in days rather than the minutes typical of endogenous GLP-1.
Receptor activation occurs at GLP-1 receptors distributed across pancreatic islets, the hypothalamus, and the gastrointestinal tract. Binding triggers G protein signaling that raises cyclic AMP and enhances glucose-dependent insulin release. Because the effect depends on prevailing glucose levels, insulin secretion does not rise when blood sugar is already low. Signaling in the brain and gut also influences appetite and gastric emptying, which is why the compound appears in both metabolic and weight-related research literature.
Development began in the early 2010s with the goal of extending GLP-1 activity beyond the brief window achieved by native peptide infusion. The earliest approved formulation was a subcutaneous injection given once weekly. A later oral tablet pairs the peptide with an absorption enhancer, sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, usually shortened to SNAC. That carrier lowers local pH and helps the peptide cross gastric tissue. Both routes deliver the same active molecule.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Acylated GLP-1 receptor agonist | 31-residue synthetic peptide |
| Molecular formula | C187H291N45O59 | established for the free peptide |
| Appearance | White to off-white powder | as supplied before formulation |
| Solubility | Freely soluble in water | aqueous buffers near neutral pH |
| Typical storage | 2 to 8 degrees Celsius, protected from light | powder and solution forms differ in shelf life |
该分子作为 GLP-1 受体的选择性激动剂发挥作用，受体属于 B 类 G 蛋白偶联受体家族，激活后经 Gs 通路提升细胞内环腺苷酸水平。在胰腺 β 细胞，信号促进葡萄糖依赖性的胰岛素释放，血糖偏低时该作用明显减弱。在胰岛 α 细胞，胰高血糖素分泌受到抑制。中枢神经系统与胃肠道同样存在受体表达，相应信号参与食欲调节以及胃排空速率的降低。
皮下注射后吸收相对缓慢，绝对生物利用度约为百分之八十九，血药浓度峰值通常出现在给药后一到三天。与白蛋白结合使清除减慢，终末半衰期约为一百六十五小时，接近一周。连续给药约四到五周后达到稳态暴露水平。表观分布容积约为每千克零点二五升，血浆蛋白结合率超过百分之九十九。代谢以蛋白水解切割和脂肪二酸侧链的 β-氧化为主，相关产物主要经尿液与粪便排出。
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nm is the standard purity method, reported as area percent. Mass spectrometry, usually with electrospray ionisation, confirms identity and reveals covalent modifications. Size-exclusion chromatography quantifies aggregates and fragments. Peptide mapping after enzymatic digestion localises changes to specific sequence regions. Circular dichroism and infrared spectroscopy report on secondary structure, while light scattering tracks particle formation in liquid formulations. No single technique captures every quality attribute.
Quality control relies on pharmacopoeial monographs where they exist, combined with in-house specifications for identity, purity, water content, and counter-ion composition. Reference standards allow calibration across laboratories, although certified materials for every analogue are not universally obtainable. Batch records, chromatograms, and mass spectra form the documentation trail. Regulatory classification varies by jurisdiction and intended use, and research-grade material differs from pharmaceutical-grade material in testing scope. Analytical uncertainty is often expressed as relative standard deviation across replicate injections.
Lyophilised semaglutide is generally held at -20 °C or below, protected from light and moisture. Reconstituted solutions are typically kept at 2-8 °C and used within a defined window because degradation accumulates over time. Repeated freeze-thaw cycles are discouraged, since each cycle can promote aggregation and reduce monomeric content. Room-temperature stability of the solid has been examined in some studies but remains incompletely characterised for long durations, so cold storage is the conservative default for research material.
However, that 2006 review pre-dates recent data, which, although still too soon to be certain, suggest that the increase in childhood obesity in the US, the UK, and Sweden might be abating.3–5 A British longitudinal study has found that obesity restricted to childhood has minimal influence on adult outcomes at age 30. The study also found that, while obesity that continues into adulthood has little influence on men's outcomes, it makes women less likely to have ever been employed or to currently have a romantic partner. A 2017 National Bureau of Economic Research paper found that childhood obesity in the United States increases medical costs by $1,354 a year (in 2013 dollars).
Architecture The topic of the origin of Romanian culture began to be discussed by the end of the 18th century among the Transylvanian School scholars. Several writers rose to prominence in the 19th century, including: George Coșbuc, Ioan Slavici, Mihail Kogălniceanu, Vasile Alecsandri, Nicolae Bălcescu, Ion Luca Caragiale, Ion Creangă, and Mihai Eminescu, the later being considered the greatest and most influential Romanian poet, particularly for the poem Luceafărul. In the 20th century, a number of Romanian artists and writers achieved international acclaim, including: Tristan Tzara, Marcel Janco, Mircea Eliade, Nicolae Grigorescu, Marin Preda, Liviu Rebreanu, Eugène Ionesco, Emil Cioran, and Constantin Brâncuși. Brâncuși has a sculptural ensemble in Târgu Jiu, while his sculpture Bird in Space, was auctioned in 2005 for $27.5 million. Romanian-born Holocaust survivor Elie Wiesel received the Nobel Peace Prize in 1986, while Banat Swabian writer Herta Müller received the 2009 Nobel Prize in Literature.
In Ireland, most universities and technological universities are publicly funded but institutionally autonomous rather than directly state-owned. Higher education is provided by universities, technological universities, institutes of technology, colleges of education and specialist institutions. The Higher Education Authority is the statutory agency responsible for allocating exchequer funding to universities, institutes of technology and other higher education institutions. Under the Free Fees Initiative, the state pays undergraduate tuition fees for eligible students, while students are required to pay a student contribution charge. For the 2025/26 academic year, the student contribution charge is €2,500 per year. Independent and private higher education institutions also operate in Ireland. The Royal College of Surgeons in Ireland was authorised to use the title "university" in Ireland in 2019, becoming RCSI University of Medicine and Health Sciences; it describes itself as an independent, not-for-profit university.
Sources: en.wikipedia.org
With some hesitation Fermi agreed to self-censor. But Joliot-Curie did not, and in April 1939 his team in Paris, including Hans von Halban and Lew Kowarski, reported in the journal Nature that the number of neutrons emitted with nuclear fission of uranium was then reported at 3.5 per fission. Szilard and Walter Zinn found "...the number of neutrons emitted by fission to be about two." Fermi and Anderson estimated "a yield of about two neutrons per each neutron captured."
==== Catechol O-methyltransferase (COMT) inhibitors ==== Entacapone (Comtan) – catechol O-methyltransferase (COMT) inhibitor Opicapone (BIA 9-1067; BIA-91067; Ongentys; ONO-2370) – catechol O-methyltransferase (COMT) inhibitor [341] Tolcapone (RO-407592; Tasmar) – catechol O-methyltransferase (COMT) inhibitor [342]
Others have found that no bias exists on average in an officer's decision to stop a citizen, but bias may exist in an officer's decision to frisk a citizen. Carter oversaw the largest scale back of incarceration in US history. He presided over a 34% decline in sentenced prisoners between 1977 and 1980, a reduction of 9,625 inmates. That was the largest of any president on record, both as a percentage and in absolute numbers.
In Jewish tradition, honey is a symbol for the new year, Rosh Hashanah. At the traditional meal for that holiday, apple slices are dipped in honey and eaten to bring a sweet new year. Some Rosh Hashanah greetings show honey and an apple, symbolizing the feast. In some congregations, small straws of honey are given out to usher in the new year. Pure honey is considered kosher (permitted to be eaten by religious Jews), though it is produced by a flying insect, a non-kosher creature; eating other products of non-kosher animals is forbidden. It belongs among the parve (neutral) foods, containing neither meat nor dairy products and allowed to be eaten together with either. Early Christians used honey as a symbol of spiritual perfection in christening ceremonies. In Islam, an entire chapter (Surah) in the Quran is called an-Nahl (the Bees). According to his teachings (hadith), Muhammad strongly recommended honey for healing purposes. The Quran promotes honey as a nutritious and healthy food, saying:
Sources: en.wikipedia.org
== Reception == Action Half-Life was the favored modification for a small subculture described by Rock, Paper, Shotgun's writer Quintin Smith as a "mad cabal of mappers who obsessed over easter eggs", with some levels containing secret areas much larger and more complex than the main level. These often included whole story-lines, puzzles, and scripted sequences. IGN said the game is a standard shooter aside from the stunts and although they look cool, they get tiresome quickly. PC Games liked the level design and said the game is more suited for experienced players. XtremPC played the beta 2.7 version and said the game is far below the quality of Action Quake 2. CNET Gamecenter placed it on its list of top 10 Half-Life mods, writing: "Action Half-Life, however, manages to capture a sense of danger and suspense that's missing from most frag-a-minute deathmatches."
=== Coagulase === The coagulase test determines whether an organism can produce the enzyme coagulase, which causes the fibrin to clot. Inoculating a plasma test tube with the microbe indicates whether coagulase is produced. A clot indicates the presence of coagulase, while no clot indicates the lack of coagulase.
The involvement of the king's son-in-law Iñaki Urdangarín in the corruption scandal known as the Nóos affair caused enormous damage to the image of the monarchy, as polls immediately reflected. The first official reaction of the Casa del Rey came on December 12, 2011, when it was decided to remove Urdangarín from official acts due to his "non-exemplary" behavior. In the Christmas Message the king spoke of "justice being equal for all". Four days later, Urdangarín was charged and between Saturday 25 and Sunday February 26, 2012, he had to testify before the judge in Palma de Mallorca. Another hard blow to the prestige of the monarchy came two months later, when on April 14, 2012, it was learned that King Juan Carlos had broken his hip on an elephant hunt in Botswana and that he had been rushed to Madrid for surgery. The news sparked a huge controversy that forced the king to apologize when he left the clinic. "I am very sorry. I made a mistake and it won't happen again," he said. On November 21, 2013, the king underwent another hip operation. It was the third surgery in less than a year, and the ninth in the last five. At the first official act in which he intervened, the celebration of Pascua Militar on January 6, 2014, he appeared tired and unwell. Just one day later, the judge of the Nóos affair, José Castro Aragón, charged the infanta Cristina de Borbón for the second time – the first had been dismissed the previous year by the Audiencia de Palma – for money laundering and tax crimes.
Sources: en.wikipedia.org
Native GLP-1 is degraded within minutes by dipeptidyl peptidase-4 and neutral endopeptidases. Semaglutide carries a non-natural amino acid at position eight that blocks that cleavage, and a fatty diacid side chain that binds albumin. The result is a much longer duration of action than the native hormone.
The fatty diacid chain associates strongly with serum albumin, which keeps the peptide in circulation and shields it from rapid renal clearance. Bound peptide is released gradually, producing a sustained receptor signal. This mechanism also reduces the peak-to-trough variation seen with shorter-acting analogues.
The balance between peripheral receptor activation and signalling in the central nervous system is not fully resolved. The extent to which slowed gastric emptying accounts for reduced energy intake, compared with direct effects on appetite circuits, is debated. Long-term effects on lean mass and on tissues outside the gut and brain are still under study.
Native GLP-1 is degraded within minutes by circulating enzymes. The synthetic version carries substitutions at positions that block enzymatic cleavage, plus a fatty acid side chain that promotes albumin binding. These two changes together extend circulation time from minutes to roughly a week.