If you have been reading about incretin and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
定量分析的主流方法是反相高效液相色谱联用紫外或质谱检测，利用肽在疏水固定相上的保留行为确定纯度与含量。对于生物基质中的浓度测定，常采用液相色谱串联质谱，并配合固相萃取或蛋白沉淀进行样品前处理。免疫分析法也可使用，但可能受到结构相关肽的交叉反应干扰。
纯度评估通常综合反相色谱、体积排阻色谱与质谱三方面信息：前者反映疏水性杂质，后者反映聚集体，质谱则确认分子量与主要降解产物。有关降解途径的完整图谱——例如脱酰胺、氧化与水解各占多大比例——在不同储存条件下仍有差异，属于需要逐案验证的问题。
Clinical development proceeded through large phase 3 programmes in type 2 diabetes and in obesity or overweight with at least one weight-related comorbidity. Regulatory approvals followed in several jurisdictions for both indications. Weekly subcutaneous dosing reflects an elimination half-life of roughly five days. Open questions include the durability of metabolic effects after treatment stops, long-term cardiovascular and hepatic outcomes beyond completed trials, and whether the dual mechanism confers benefits independent of total receptor occupancy. Published literature continues to expand on these points. Substantial uncertainty remains about interindividual variability in response.
Tirzepatide is a synthetic linear peptide of 39 amino acids that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Its sequence derives from native GIP but incorporates non-natural residues and a C20 fatty diacid moiety linked to a lysine side chain. The lipophilic chain promotes albumin binding, which slows renal clearance and extends circulation time. The unmodified peptide has a molecular formula of C225H348N48O68 and a molecular mass near 4,813 daltons.
| Property | Value | Notes |
|---|---|---|
| 储存温度 | 2 至 8 摄氏度 | 固体粉末，避光密封 |
| 外观 | 白色至类白色冻干粉 | 溶解后为澄清至微乳光 |
| 溶解性 | 易溶于水性缓冲液 | 避免剧烈振荡 |
| 常规纯度方法 | 反相高效液相色谱 | 紫外或质谱检测 |
| 定量方法 | 液相色谱串联质谱 | 配合固相萃取前处理 |
Like most synthetic peptides of this size, the material is commonly supplied as a lyophilised powder that appears white to off-white. It dissolves in aqueous buffers and in mixtures of water with a small proportion of organic solvent, though the fatty acid portion reduces solubility in pure water relative to short peptides. Hygroscopic behaviour is reported for many peptide powders, so weighing is usually performed quickly and under controlled humidity. Working solutions are typically prepared fresh and kept cold.
Long-term storage of lyophilised peptide powder is generally at minus twenty degrees Celsius or colder, with desiccant and protection from light. Short-term storage at two to eight degrees Celsius is common during active use. In solution, stability depends strongly on pH, concentration, and the presence of preservatives, and hydrolysis or aggregation can develop over weeks. Published stability data specific to this molecule are limited, so recommended conditions for research material are usually extrapolated from general peptide handling practice rather than from a dedicated study.
Bulk peptide material is normally characterised by reversed-phase high-performance liquid chromatography, which separates the target sequence from truncation products and other closely related impurities. Ultraviolet detection near 214 nanometres is common because the peptide backbone absorbs in that region. Mass spectrometry, usually electrospray ionisation coupled to a mass analyser, is used to confirm the molecular mass. Because the molecule carries a lipophilic side chain, gradient methods often need a relatively high organic modifier fraction to elute it within a practical retention window.
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Identity and purity of tirzepatide are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Because the molecule carries several modifications, gradient conditions are adjusted to resolve the intact peptide from deamidation and oxidation products. Enzymatic digestion followed by peptide mapping confirms the primary sequence and locates specific modifications. Quantitation in biological matrices typically uses liquid chromatography with tandem mass spectrometry after solid-phase extraction. Immunoassays are used less often, since antibody cross-reactivity with closely related peptides can bias results.
Common degradation routes include hydrolysis of labile amide bonds, deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation. Aggregates can form during freeze-thaw cycling, at elevated pH, or when peptide concentration is high. Each route produces characteristic chromatographic or mass shifts that are tracked during stability studies. Whether a given minor impurity alters biological activity is often an open question, and specification limits are typically set on identity and purity rather than on functional data for trace species.
Lyophilized material is generally held at -20 degrees Celsius or lower, desiccated and protected from light, where it remains stable for extended periods. Reconstituted or ready-to-use solution is usually kept at 2 to 8 degrees Celsius with minimal agitation. Repeated freeze-thaw cycles should be avoided because they promote aggregation and reduce the soluble monomer fraction. Shipment of frozen solid commonly uses dry ice, while refrigerated liquid moves with validated cold packs. Stability beyond documented periods is not established.
Characterization of the peptide relies on reversed-phase high-performance liquid chromatography for purity and related-substance profiling, with ultraviolet detection near 214 nanometers. Mass spectrometry confirms molecular mass and reveals modifications such as oxidation or deamidation. Peptide mapping after enzymatic digestion verifies the amino acid sequence, while amino acid analysis supplies compositional data. Circular dichroism and infrared spectroscopy are used to assess secondary structure, particularly the alpha-helical content that influences aggregation behavior in solution.
On 19 September, Trump announced that another vessel allegedly carrying drugs had been destroyed in the Caribbean and that three people had been killed; Trump stated that the vessel was "affiliated with a Designated Terrorist Organization conducting narcotrafficking in the USSOUTHCOM area of responsibility", but did not specify where within the United States Southern Command the strike occurred, the country of origin, or the alleged criminal affiliation. The Dominican Republic later announced that, under its National Directorate for Drug Control and the Dominican Navy, it had cooperated with the US Navy to locate the boat, which was about 80 nautical miles (130 km) south of Dominican-controlled Beata Island. After the boat was destroyed the Dominican Navy salvaged 377 packages of cocaine amounting to 1,000 kilograms (2,200 lb). The Directorate stated that "This is the first time in history that the United States and the Dominican Republic carry out a joint operation against narco terrorism in the Caribbean". Reuters reported that there was a previously unannounced strike on 16 October 2025, which included survivors. The US alleged that the vessel struck was a narco-submarine. Two people were killed and two survived. The survivors were rescued and detained on a US Navy ship. By 19 October, both were repatriated to their respective countries of origin, Colombia and Ecuador. On 17 October, a strike in international waters on an alleged Colombian National Liberation Army (ELN) drug vessel killed an additional three people.
=== Acid dissolution === Acids can be used to learn more about fossil eggs. Diluted acetic acid or EDTA can be used to expose the microstructure of shell that has been damaged by weathering. Acids are also used to extract embryo skeletons from the egg encasing them. Even fossilized soft tissue like muscle and cartilage as well as fat globules from the original egg yolk can be uncovered using this method. Amateur paleontologist Terry Manning has been credited with groundbreaking work developing this technique. First, the paleontologist must submerge the egg in a very dilute phosphoric acid bath. Since the acid solution can penetrate the egg, every few days the specimen must be soaked in distilled water to prevent the acid from damaging the embryo before it is even exposed. If embryonic fossil bone is revealed after drying from the water bath, the exposed fossils must be delicately cleaned with fine instruments like needles and paint brushes. The exposed bone is then coated with plastic preservatives like Acryloid B67, Paraloid B72, or Vinac B15 to protect it from the acid when submerged for another round. The complete process can take months before the whole embryo is revealed. Even then only about 20% of the eggs subjected to the process reveal any embryo fossils at all.
is the first derivative of concentration with respect to time, i.e. the change in concentration with time. It is derived from a mass balance. Clearance of a substance is sometimes expressed as the inverse of the time constant that describes its removal rate from the body divided by its volume of distribution (or total body water). In steady-state, it is defined as the mass generation rate of a substance (which equals the mass removal rate) divided by its concentration in the blood.
Anthropodermic bibliopegy—the binding of books in human skin—peaked in the 19th century. The practice was most popular amongst doctors, who had access to cadavers in their profession. It was nonetheless a rare phenomenon even at the peak of its popularity, and fraudulent claims were commonplace; by 2020, the Anthropodermic Book Project had confirmed the existence of 18 books bound in human skin, out of 31 tested cases. The ability to unequivocally identify book bindings as being of human skin dates only to the mid-2010s. For many years, identification tended to be visual, based predominantly on the structure of pores such as hair follicles in the skin. This could be combined with evidence as circumstantial as the bindings being of subjectively poor quality—taken as a sign the skin used was acquired through suspicious means. In the early twenty-first century, DNA testing emerged as a potential means of identification, but this was confounded by human handling; items frequently touched by human hands could produce false positives, as tests would pick up on their remnants. DNA testing also proved non-viable owing to the degradation of DNA over time and the acceleration of such degradation by the tanning process used to turn skin into leather. The development of peptide mass fingerprinting permitted conclusive testing and became the gold standard method. The first book confirmed as authentic through its use was in 2014; it was a copy of Des destinées de l'ame by the French philosopher Arsène Houssaye, held in the Houghton Library of Harvard University.
==== South Korea ==== There are currently two locations in Seoul, in the Itaewon and Hongdae districts, which attract the most foreigners and college students. The two branches opened in the summer of 2010, Itaewon's branch coming first. A Taco Bell had long been a presence at the U.S. Army's Yongsan Garrison, which is off-limits to non-military personnel, and for a time there was a tongue-in-cheek grassroots campaign by non-Korean, non-military foreigners in Seoul to get another Taco Bell location.
Sources: en.wikipedia.org
== Chain Home, Chain Home Low, Chain Home Extra Low, ROTOR and tropo-scatter stations == Notes: Some of the Chain Home Low sites were co-located with the larger Chain Home radars. Chain Home Extra Low equipment was co-located with "Chain Home" and "Chain Home Low" as well as at separate sites, but were of a less permanent nature, usually with mobile equipment. ROTOR was the post war Radar interception system created from existing radar installations. NARS, the North Atlantic Radio System, was an extension of the US Distant Early Warning system tropo-scatter communications network. ACE High provided long-range communications for NATO.
This is attributed to "bound-state β− decay" of the fully ionised atom – the electron is emitted into the "K-shell" (1s atomic orbital), which cannot occur for neutral atoms in which all low-lying bound states are occupied.
=== Hair === As male-pattern hair loss is caused by androgens, particularly dihydrotestosterone, feminizing hormone therapy causes the rapid cessation and reversal of hair loss, though the degree of regrowth may vary. In many cases, the use of estrogens and antiandrogens have a more profound impact on hair loss compared to treatments used in men such as finasteride due to the greater suppression of dihydrotestosterone. Occasionally, hormones can also have effects on scalp hair texture, depending on various genetic factors. Antiandrogens affect existing facial hair only slightly; patients may see slower growth and some reduction in density and coverage. This reduction of density is due to the decreasing hair diameter and slower terminal growth rate. Effects on hair size and density were noticeable in the first four months following the start of hormone therapy, but later subsided, with measurements staying constant. In patients in their teens or early twenties, antiandrogens prevent new facial hair from developing if testosterone levels are within the normal female range. Body hair (on the chest, shoulders, back, abdomen, buttocks, thighs, tops of hands, and tops of feet) turns, over time, from terminal ("normal") hairs to tiny, blonde vellus hairs. Arm, perianal, and perineal hair is reduced but may not turn to vellus hair on the latter two regions (some cisgender women also have hair in these areas). Underarm hair changes slightly in texture and length, and pubic hair becomes more typically female in pattern. Lower leg hair becomes less dense.
== List of hosts == Amur Cossack Host (1860–1918) Astrakhan Cossack Host (1737–1920) Azov Cossack Host (1832–1862) Baikal Cossack Host (1851-1920) Bashkir Host (1798-1865) Black Sea Cossack Host (1787–1864) Buh Cossack Host (1769–1817) Caucasus Line Cossack Host (1832–1860) Danube Cossack Host (1828–1868), an Imperial Russian Cossack Host formed from descendants of the Zaporozhian Cossacks Don Cossack Host (1570-1918, reconstituted in 1992) Greben Cossacks Host (1711–1745–1845-60–1920, reconstituted in 1992) Kuban Cossack Host (1860–1920, reconstituted in 1992) Orenburg Cossack Host (1755–1920) Semiryechye Cossack Host (1867–1920) Siberian Cossack Host (1582-1918) Terek Cossack Host (1577–1792–1860–1920, reconstituted in 1992) Transbaikal Cossack Host (1851–1920) Ural Cossack Host (c. 14th century-end–1920) Ussuri Cossack Host (1889–1922, re-established in 1990) Volga Cossack Host (1734–1777) Zaporozhian Host (1572/1649–1775), of the Zaporozhian Cossacks who lived in Zaporizhia, Dnieper Ukraine, during the 16th — 18th centuries.
Sources: en.wikipedia.org
Prior to 2000, only seven film series had grossed over $1 billion at the box office: James Bond, Star Wars, Indiana Jones, Rocky, Batman, Jurassic Park, and Star Trek. Since the turn of the century, that number has increased to over a hundred. This is partly due to inflation and market growth, but it is also due to Hollywood's adoption of the franchise model: films that have built-in brand recognition such as being based on a well-known literary source or an established character. The methodology is based on the concept that films associated with things audiences are already familiar with can be more effectively marketed to them, and as such are known as "pre-sold" films within the industry. A franchise is typically defined to be at least two works derived from a common intellectual property. Traditionally, the work has a tautological relationship with the property, but this is not a prerequisite. An enduring staple of the franchise model is the concept of the crossover, which can be defined as "a story in which characters or concepts from two or more discrete texts or series of texts meet". A consequence of a crossover is that an intellectual property may be utilized by more than one franchise. For example, Batman v Superman: Dawn of Justice belongs to not only the Batman and Superman franchises, but also to the DC Extended Universe, which is a shared universe. A shared universe is a particular type of crossover where a number of characters from a wide range of fictional works wind up sharing a fictional world.
=== Thermochemistry === L. K. Doraiswamy, 2005, "Estimation of properties of organic compounds (Ch. 3)," pp. 36–51, 118-124 (refs.), in Organic Synthesis Engineering, Oxford, Oxon, ENG:Oxford University Press, ISBN 0198025696, accessed 22 June 2015. (This book chapter surveys a very wide range of physical properties and their estimation, including the narrow list of thermochemical properties appearing in the June 2015 WP article, placing the Benson et al. method alongside many other methods. L. K. Doraiswamy is Anson Marston Distinguished Professor of Engineering at Iowa State University.) Irikura, Karl K.; Frurip, David J. (1998). "Computational Thermochemistry". In Irikura, Karl K.; Frurip, David J. (eds.). Computational Thermochemistry: Prediction and Estimation of Molecular Thermodynamics. ACS Symposium Series. Vol. 677. American Chemical Society. pp. 2–18. doi:10.1021/bk-1998-0677.ch001. ISBN 978-0-8412-3533-5.
== Interactions == Bupropion may lower the seizure threshold. Therefore, caution is advised when combining Auvelity (which contains bupropion) with other medications that also lower the seizure threshold, such as alcohol, tramadol, clozapine, and CNS stimulants like amphetamine, cocaine, and methylphenidate. Dextromethorphan (a component of Auvelity) increases serotonin; this can lead to a life threatening complication known as serotonin syndrome (especially when serotonergic drugs are combined). Therefore, caution should be used when combining dextromethorphan with other drugs that increase serotonin. Certain drugs that increase serotonin include CNS stimulants like amphetamine and cocaine, selective serotonin reuptake inhibitors, and triptans. Bupropion (a component of Auvelity) may increase blood pressure and lead to hypertension. Therefore, combining Auvelity with other drugs that increase blood pressure may result in hypertension. Some examples of drugs that increase blood pressure are stimulants like cocaine, amphetamine, caffeine, methylphenidate, and pseudoephedrine, monoamine oxidase inhibitors, and certain NSAIDs like ibuprofen. Because Auvelity is a CYP2D6 inhibitor, it can increase the plasma concentrations of drugs metabolized by this enzyme. Examples of such drugs are risperidone, aripiprazole, codeine, metoprolol, and tamoxifen.
=== Tree === Aristotelia chilensis is a small dioecious evergreen tree that can reach 4 to 5 metres (13 to 16 ft) in height. Its divided trunk has a smooth bark. Its branches are abundant, thin and flexible. Its leaves are simple, opposite, hanging, oval-lanceolate, naked and coriaceous, with serrated edges. The leaf venation is highly visible, and the leaf stalk is a strong red color. In the beginning of spring, the tree sheds the old leaf cohort, which is used as a carbohydrate source to form the new leaves and flowers.
== History == Shotgun proteomics arose from the difficulties of using previous technologies to separate complex mixtures. In 1975, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was described by O’Farrell and Klose with the ability to resolve complex protein mixtures. The development of matrix-assisted laser desorption ionization (MALDI), electrospray ionization (ESI), and database searching continued to grow the field of proteomics. However these methods still had difficulty identifying and separating low-abundance proteins, aberrant proteins, and membrane proteins. Shotgun proteomics emerged as a method that could resolve even these proteins.
Sources: en.wikipedia.org
建议在低温、避光、干燥环境中密封保存，常见条件为 2 至 8 摄氏度，长期存放可置于更低温度。应避免反复冻融，并尽量减少容器开启次数。
溶解后的稳定时间通常短于固体形态，受浓度、缓冲液和容器材质影响。冷藏条件下一般只能维持较短时间，具体期限应通过实际稳定性实验确认。
反相高效液相色谱用于纯度与含量测定，液相色谱串联质谱用于生物基质中的定量，体积排阻色谱用于检测聚集体。多种方法结合才能较完整地表征样品。
It is a dual GIP and GLP-1 receptor agonist, frequently grouped with incretin-based peptide therapeutics. It is a peptide rather than a small molecule and is given by subcutaneous injection.