A practical reference on fatty diacid: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-04. Anything still debated is marked as such rather than presented as settled.
Pharmacological activity arises from agonism at the glucagon-like peptide-1 receptor, a G protein-coupled receptor expressed in the pancreas, the gastrointestinal tract, and the brainstem. Receptor activation raises intracellular cyclic adenosine monophosphate and enhances insulin release in a glucose-dependent manner, an effect that diminishes when blood glucose concentration is low. Other effects include slowed gastric emptying and hypothalamic satiety signalling. These pathways are described well. Receptor desensitisation rates across tissues, relative to the endogenous hormone, are still under investigation, and reported findings differ between laboratories.
The company that developed the compound filed it as a long-acting analogue, and it gained first approval in 2017 for type 2 diabetes. Later authorisations from several regulators extended the indication to chronic weight management, and the World Health Organization added the glucagon-like peptide-1 receptor agonist drug class to its model list of essential medicines in 2023. Production uses solid-phase peptide synthesis followed by side-chain conjugation and chromatographic purification. Supply constraints and cost differences across regions are well documented. Literature on long-term outcomes continues to grow, with many trials reporting surrogate endpoints rather than hard clinical endpoints.
Degradation proceeds along several parallel routes. Deamidation of asparagine and glutamine residues generates charged variants that shift retention time in chromatographic analysis. Oxidation targets methionine and can be accelerated by trace metals or dissolved oxygen. Non-covalent aggregation produces dimers, oligomers, and larger species that are difficult to reverse. Isomerisation at aspartate residues is slower but measurable under thermal stress. The distribution among these pathways depends on pH, buffer composition, ionic strength, and the presence of excipients such as sugars or surfactants.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | 31-amino-acid peptide | Modified glucagon-like peptide-1 analogue |
| Molecular mass | approximately 4114 Da | Calculated for the free peptide backbone |
| Appearance | white to off-white powder | Typical of purified lyophilised peptide batches |
| Solubility class | freely soluble in water | Aqueous solubility improves at slightly alkaline pH |
| Typical storage | -20 degrees Celsius, dry, dark | Protect from repeated freeze-thaw cycles |
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。
序列层面的改动同时解决了两个问题，即酶解稳定性与肾脏清除速度。天然 GLP-1 在循环中的半衰期仅约两分钟，主要被二肽基肽酶-4 迅速灭活。酰化侧链与白蛋白的可逆结合形成循环储库，使分子缓慢释放并持续激活受体。这种设计思路后来被广泛用于同类长效肽的开发，属于该类药物化学改造的典型范式。
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
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.
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.
The identity of Jack the Ripper is a notorious example of an outstanding cold case, with numerous suggestions as to the identity of the serial killer. Similarly, the Zodiac Killer has been studied extensively for almost 50 years, with numerous suspects discussed and debated. The perpetrators of the Wall Street bombing of 1920 have never been positively identified, though the Galleanists, a group of Italian anarchists, are widely believed to have planned the explosion. The burning of the Reichstag building in 1933 remains controversial and although Marinus van der Lubbe was tried, convicted and executed for arson, it is possible that the Reichstag fire was perpetrated by the Nazis to enhance their power and destroy democracy in Germany.
For Darwin, the problem was how species arose from a common ancestor, but he did not attempt to find rules for delineation of species. The species problem was tackled by the ornithologist Ernst Mayr, who was able to demonstrate that geographical isolation and the accumulation of genetic differences led to the splitting of species. Early ornithologists were preoccupied with matters of species identification. Only systematics counted as true science and field studies were considered inferior through much of the 19th century. In 1901, Robert Ridgway wrote in the introduction to The Birds of North and Middle America that:
The occurrence of diabetes in monozygotic and dizygotic twins has been tested, and these rates can give insight into the genetic component of diabetes. In type 1 diabetes, the chance of monozygotic twins both developing the disease was greater than the risk for dizygotic twins. However, the rate of any siblings contracting the disease was much greater with type 2 diabetes. This indicates that there must be a large environmental factor involved in type 2, and some genetic factor with type 1. Type 1 diabetes has only about a 50% concordance rate (the percentage of two identical twins both having the condition). Thus, it is not fully genetic, but the results from the twin studies point to some inherited risk. Type 1 diabetes can occur at any age, and a significant proportion is diagnosed during adulthood. Latent autoimmune diabetes of adults (LADA) is the diagnostic term applied when type 1 diabetes develops in adults; it has a slower onset than the same condition in children. Given this difference, some use the unofficial term "type 1.5 diabetes" for this condition. Adults with LADA are frequently initially misdiagnosed as having type 2 diabetes, based on age rather than a cause. LADA leaves adults with higher levels of insulin production than type 1 diabetes, but not enough insulin production for healthy blood sugar levels.
Sources: en.wikipedia.org
Actinidia chinensis var. deliciosa (kiwifruit) Ambrosia artemisiifolia (short ragweed) Ananas comosus (pineapple) Apium graveolens (celery) Arachis hypogaea (peanut) Artemisia vulgaris (mugwort) Betula verrucosa (European white birch) and Betula pendula (silver birch) Capsicum annuum (bell pepper) Chenopodium album (pigweed) Citrus sinensis (sweet orange) Corylus avellana (hazel) Cucumis melo (muskmelon) Daucus carota (carrot) Glycine max (soybean) Helianthus annuus (sunflower) Hevea brasiliensis (para rubber tree [latex]) Malus domestica (apple) Olea europaea (olive) Phleum pratense (timothy grass) Phoenix dactylifera (date palm) Prunus persica (peach) Pyrus communis (pear) Salsola kali (Russian thistle) Sinapis alba (yellow mustard) Solanum lycopersicum (tomato)
Dapoxetine, sold under the brand name Priligy among others, is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of premature ejaculation (PE) in men ages 18 to 64 years old. Dapoxetine works by inhibiting the serotonin transporter, increasing serotonin's action at the postsynaptic cleft, and as a consequence promoting ejaculatory delay. As a member of the SSRI family, dapoxetine was initially created as an antidepressant. However, unlike other SSRIs, dapoxetine is absorbed and eliminated rapidly in the body. Its fast-acting property makes it suitable for the treatment of PE, but not as an antidepressant. Originally created by Eli Lilly pharmaceutical company, dapoxetine was sold to Johnson & Johnson in 2003 and submitted as a New Drug Application to the US Food and Drug Administration (FDA) for the treatment of PE in 2004. Dapoxetine is sold in several European and Asian countries, and in Mexico. In the US, dapoxetine has been in phase III development. In May 2012, US-based Furiex Pharmaceuticals reached an agreement with ALZA Corp and Janssen Pharmaceuticals to market dapoxetine in the United States, Japan, and Canada, while selling the rights to market the drug in Europe, most of Asia, Africa, Latin America, and the Middle East to Menarini.
=== 1971 === January 25: Idi Amin launches a successful coup d'état against Milton Obote in Uganda and declares himself President of Uganda. Under Amin, Uganda would switch allegiances to the Eastern Bloc and develop strong ties to the Soviet Union and East Germany. February 8: South Vietnamese forces enter Laos to briefly cut the Ho Chi Minh Trail. February 11: Seabed Arms Control Treaty is signed banning the placement of nuclear weapons outside of a country's 12-mile (22.2 km) coastal zone. March 10: Dominion of Ceylon declared under emergency conditions after communist People's Liberation Front attacks the American embassy. March 25 : Bangladeshi genocide From The West Pakistani Troops until 16 December March 26: Bangladeshi Declaration of Independence and Bangladesh Liberation War begin April 19: Salyut 1 is launched becoming the first space station. May 15: Anwar Sadat's Corrective Revolution purges Nasserist members of the government and security forces, and eventually expels the Soviet military from Egypt. May 28: Mars 3 is launched. May 30: Mariner 9 is launched. July 19–22: a communist-backed coup attempted unsuccessfully against Jaafar Nimeiry in Sudan. September: 105 Soviet officials expelled from Great Britain by Prime Minister Edward Heath in Operation FOOT. September 3: Four-Power Agreement on Berlin is signed by the United Kingdom, the Soviet Union, France, and the United States. October 11: Salyut 1 burns up in the atmosphere.
Cloning of the YAP1 gene facilitated the identification of a modular protein domain, known as the WW domain. Two splice isoforms of the YAP1 gene product were initially identified, named YAP1-1 and YAP1-2, which differed by the presence of an extra 38 amino acids that encoded the WW domain. Apart from the WW domain, the modular structure of YAP1 contains a proline-rich region at the very amino terminus, which is followed by a TID (TEAD transcription factor interacting domain). Next, following a single WW domain, which is present in the YAP1-1 isoform, and two WW domains, which are present in the YAP1-2 isoform, there is the SH3-BM (Src Homology 3 binding motif). Following the SH3-BM is a TAD (transactivation domain) and a PDZ domain-binding motif (PDZ-BM) (Figure 1).
Sources: en.wikipedia.org
The mascot made national headlines on January 24, 2023, when a parody tweet referencing the M&M's controversy was posted to its social media profiles, showing Rooty wearing pants, claiming that the mascot's lack of pants was "polarizing". Outrage started emerging from conservative sectors, including Fox News (the report also aired on sister network Fox Business), claiming it to be real. In a follow-up tweet, A&W said that the announcement was a joke. Spokesperson Liz Bazner said that the initial post was "purely in jest" and that A&W has no plans to change Rooty's outfit. In March 1998, the characters from the comic strip Blondie, including Blondie and Dagwood Bumstead, were licensed for use at A&W franchises as part of an "All American Food" campaign. A tie-in burger was scheduled for July that year.
Cohen (1955): working class teenagers joined gangs due to frustration of inability to achieve status and goals of the middle class; Cloward and Ohlin (1960): blocked opportunity, but unequal distribution of opportunities lead to creating different types of gangs (that is, some focused on robbery and property theft, some on fighting and conflict and some were retreatists focusing on drug taking); Spergel (1966) was one of the first criminologists to focus on evidence-based practice rather than intuition into gang life and culture. Participation in gang-related events during adolescence perpetuate a pattern of maltreatment on their own children years later. Klein (1971) like Spergel studied the effects on members of social workers' interventions. More interventions actually lead to greater gang participation and solidarity and bonds between members. Downes and Rock (1988) on Parker's analysis: strain theory applies, labeling theory (from experience with police and courts), control theory (involvement in trouble from early childhood and the eventual decision that the costs outweigh the benefits) and conflict theories. No ethnic group is more disposed to gang involvement than another, rather it is the status of being marginalized, alienated or rejected that makes some groups more vulnerable to gang formation, and this would also be accounted for in the effect of social exclusion, especially in terms of recruitment and retention. These may also be defined by age (typically youth) or peer group influences, and the permanence or consistency of their criminal activity.
== External links == GeneReviews/NCBI/NIH/UW entry on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, Autosomal Dominant OMIM entries on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, Autosomal Dominant Overview of all the structural information available in the PDB for UniProt: P10600 (Transforming growth factor beta-3) at the PDBe-KB.
== Airlines and destinations == In 2025, Hohhot Baita International Airport plans to operate 139 routes, serving 92 cities in total, including 83 nonstop destinations and 6 international or regional cities.
In addition, they also used petroleum to cover their bodies against insect bites and as a form of jelly to prevent their skins from drying out. Peyote – indigenous people realized the antibiotic property of peyote and used the extract to treat fevers and enhance the energy in their bodies and treatment as an anesthetic. Pineapple – indigenous people residing in what is now Brazil and the Paraná River valley of Paraguay were the first to cultivate the pineapple. From there, pineapple cultivation spread to Mexico, Central and South America and the Caribbean. Indigenous Americans used the pineapple as a source of food. Planned city construction – ancient cities in Mexico–such as Teotihuacan and the Aztec capital of Tenochtitlan–incorporated planned city design, including streets laid out in a grid pattern. Plumbing – the Maya have been found to be the earliest inventors of plumbing in Mesoamerica, with the earliest example of a pressurized water system being constructed in 750 CE—or earlier. This pressurized water system was located in the Maya site of Palenque, where public baths and toilets were accessible to the residents of the ancient city. Poncho – worn by indigenous Americans in central Mexico, the Andes and Patagonia. Popcorn – Indigenous Americans were among the earliest peoples to develop popcorn, with evidence of popcorn dating back thousands of years in the Americas. Potato – The potato was domesticated 7,000–10,000 years ago in the highlands of southern Peru and northwestern Bolivia near Lake Titicaca.
Sources: en.wikipedia.org
It is a glucagon-like peptide-1 receptor agonist, often grouped with the incretin mimetics. Its backbone is modified from the human hormone to resist enzymatic degradation and to bind albumin. These two features distinguish it from the native peptide.
No. It shares high sequence identity but carries non-natural modifications that alter its stability and clearance. The naturally occurring hormone is broken down within minutes, while the synthetic analogue circulates far longer.
Attachment to serum albumin reduces renal filtration of the peptide and shields it from enzymatic breakdown. The consequence is a much longer interval between administrations than unmodified peptides allow. The precise contribution of binding affinity to overall duration is still being quantified.
Reverse-phase high-performance liquid chromatography with ultraviolet detection is the usual choice, with results reported as area percent. Complementary methods such as size-exclusion chromatography and mass spectrometry are needed because a single separation cannot resolve every impurity class. Purity figures are therefore method dependent and should always be read alongside the technique used.