Everything below concerns Working solution. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-12-12. Numbers and descriptions here follow the published literature rather than marketing material.
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。
质量控制环节关注外观、含量、纯度、有关物质、水分与微生物限度等项目。检测结果需要有对照品和系统适用性数据支持,单次测定不足以判定批次的稳定性。实验室之间方法转移时,色谱柱品牌与梯度差异常导致保留时间漂移,因此方法验证十分必要。
Structure-activity work shows that fatty acid length, linker chemistry and the position of acylation all influence albumin affinity and receptor potency. Plasma protein binding exceeds 99 percent, which restricts distribution and slows renal clearance. Degradation proceeds largely through general proteolysis and fatty acid oxidation rather than cytochrome P450 metabolism, so exposure to common oxidative drug interactions is limited. Whether these clearance routes vary meaningfully between individuals is not fully established.
The molecule is a synthetic 39-amino-acid peptide whose backbone derives from the sequence of human glucose-dependent insulinotropic polypeptide, with several substitutions that raise metabolic stability and shift receptor preference. A C20 fatty diacid is attached through a short linker to a lysine side chain, a modification that increases binding to serum albumin. The reported monoisotopic mass is approximately 4813 Da. Near neutral pH the peptide carries a net negative charge, and the lipid tail makes the molecule markedly more hydrophobic than the unmodified parent sequence.
Dual agonism at the GIP and GLP-1 receptors underlies the observed pharmacology. Activation of GLP-1 receptors raises glucose-dependent insulin release, lowers glucagon secretion, slows gastric emptying and reduces appetite. GIP receptor activation contributes additional effects on adipose tissue and on energy balance, and the combined action on appetite appears larger than either pathway alone in animal models. Signalling bias and the relative contribution of each receptor arm to weight-related effects remain areas of active investigation.
| 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 |
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.
Receptor activation by tirzepatide raises intracellular cyclic AMP through Gs-coupled signalling at both targets. At the GLP-1 receptor the downstream effect includes glucose-dependent insulin release, suppressed glucagon secretion, delayed gastric emptying, and reduced appetite signalling in the hypothalamus. GIP receptor engagement adds insulinotropic activity and appears to influence lipid handling in adipose tissue. Because both receptors are stimulated at the same time, the pharmacological profile differs from that of selective GLP-1 receptor agonists, and the relative contribution of each arm remains an area of active investigation.
The peptide backbone contains 39 amino acids and includes alpha-aminoisobutyric acid residues, which are not among the standard proteinogenic set. A C20 fatty diacid moiety is attached through a linker, allowing the compound to bind serum albumin and extend its circulation time. This albumin binding is the main reason the molecule supports once-weekly administration rather than more frequent dosing. The measured molecular mass is approximately 4,813 daltons, placing it firmly in the peptide rather than small-molecule class.
Tirzepatide is a synthetic peptide that activates both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This dual agonist profile distinguishes it from earlier incretin-based compounds that act on a single receptor. The molecule was engineered from the native GIP sequence and carries several non-natural residues that slow enzymatic breakdown. Researchers designed it to combine the insulinotropic effects of GIP signaling with the appetite and gastric-emptying effects associated with GLP-1 activation.
Development of tirzepatide took place under a research program that sought to test whether simultaneous engagement of two incretin receptors would produce greater metabolic effects than single-receptor agonism. Clinical trials were organized into the SURPASS series for type 2 diabetes and the SURMOUNT series for obesity and weight management. Regulatory clearance for type 2 diabetes came in 2022 in the United States, followed by approval for chronic weight management in 2023. The trial programs reported reductions in glycated hemoglobin and body weight relative to comparators, though long-term cardiovascular and durability data continue to accumulate.
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.
== Bibliography == Alt-Kutscha : vol.1 Archived 2020-01-27 at the Wayback Machine Arlt, Robert; Hiyama, Satomi (2013). "Fruits of Research on the History of Central Asian Art in Berlin: The Identification of Two Sermon Scenes from Kizil Cave 206 (Fußwaschungs- höhle)". Indo-Asiatische Zeitschrift (Berlin) 17: 16–26. Beckwith, Christopher (1993). The Tibetan Empire in Central Asia: A History of the Struggle for Great Power Among Tibetans, Turks, Arabs, and Chinese During the Early Middle Ages. Princeton University Press. ISBN 0-691-02469-3. Beckwith, Christopher I. (2009). Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present. Princeton University Press. ISBN 978-0-691-13589-2. Grousset, René (1970). The Empire of the Steppes: A History of Central Asia. Rutgers University Press. ISBN 978-0-8135-1304-1. Grünwedel, Albert (1912). Altbuddhistische Kultstätten in Chinesisch-Turkistan: Bericht über archäologische Arbeiten von 1906 bis 1907 bei Kuča, Qarašahr und in der Oase Turfan. Berlin: Arthur-Baessler-Institut. Doi:10.20676/00000191. Hopkirk, Peter (1984). Foreign devils on the silk road : the search for the lost cities and treasures of Chinese Central Asia. Amherst: University of Massachusetts Press. ISBN 9780870234354. Hiyama, Satomi 檜山智美 (2013) Study on the first-style murals of Kucha: Analysis of some motifs related to the Hephthalite's period クチャの第一樣式壁畫に見られるエフタル期のモチーフについて (“Kucha no daiichi yōshiki hekiga ni mirareru Efutaru ki no mochīfu ni tsuite”).
A variety of natural and synthetic inhibitors of ATP synthase have been discovered. These have been used to probe the structure and mechanism of ATP synthase. Some may be of therapeutic use. There are several classes of ATP synthase inhibitors, including peptide inhibitors, polyphenolic phytochemicals, polyketides, organotin compounds, polyenic α-pyrone derivatives, cationic inhibitors, substrate analogs, amino acid modifiers, and other miscellaneous chemicals. Some of the most commonly used ATP synthase inhibitors are oligomycin and DCCD. E. coli ATP synthase is the simplest known form of ATP synthase, with 8 different subunit types. Bacterial F-ATPases can occasionally operate in reverse, turning them into an ATPase. Some bacteria have no F-ATPase, using an A/V-type ATPase bidirectionally. Yeast ATP synthase is one of the best-studied eukaryotic ATP synthases; and five F1, eight FO subunits, and seven associated proteins have been identified. Most of these proteins have homologues in other eukaryotes.
When a DU penetrator reaches the interior of an armored vehicle, it catches fire, often igniting ammunition and fuel and possibly causing the vehicle to explode. DU is used by the U.S. Army in 120 mm or 105 mm cannons employed on the M1 Abrams tank. The DU content in various ammunition is 180 grams (6.3 oz) in 20 mm, 200 grams (7.1 oz) in 25 mm, 280 grams (9.9 oz) in 30 mm, 3.5 kilograms (7.7 lb) in 105 mm, and 4.5 kilograms (9.9 lb) in 120 mm penetrators. DU was used during the mid-1990s in the U.S. to make hand grenades, and land mines, but those applications have been discontinued, according to Alliant Techsystems. The US Navy used DU in its 20 mm Phalanx CIWS guns, but switched in the late 1990s to armor-piercing tungsten. Only the US and the UK have acknowledged using DU weapons. The Soviet Union and Russia have used DU weaponry since the 3BM-32 Vant, designed for the 125 mm tank cannons. In 2018, TASS reported that Russia was arming some of its T-80 models with 3BM60 Svinets-2 DU rounds. 782,414 DU rounds were fired during the 1991 war in Iraq, mostly by US forces. In a three-week period of conflict in Iraq during 2003, it was estimated that between 1,000 and 2,000 tonnes of depleted uranium munitions were used. More than 300,000 DU rounds were fired during the 2003 war, the vast majority by US troops.
== Clinical implications == The MEN1 phenotype is inherited via an autosomal-dominant pattern and is associated with neoplasms of the pituitary gland, the parathyroid gland, and the pancreas (the 3 "P"s). While these neoplasias are often benign (in contrast to tumours occurring in MEN2A), they are adenomas and, therefore, produce endocrine phenotypes. Pancreatic presentations of the MEN1 phenotype may manifest as Zollinger–Ellison syndrome. MEN1 pituitary tumours are adenomas of anterior cells, typically prolactinomas or growth hormone-secreting. Pancreatic tumours involve the islet cells, giving rise to gastrinomas or insulinomas. In rare cases, adrenal cortex tumours are also seen.
It is said by the tradition, to take away the sins of the devotees when they enter a temple and to ward off evil in general. It is therefore often found in a strategic position on the gopuram or temple gateway, or near the entrance of the sanctum sanctorum.
Sources: en.wikipedia.org
The pia mater (Latin: tender mother) is a very delicate membrane. It is the meningeal envelope that firmly adheres to the surfaces of the brain and spinal cord, following all of the brain's contours (gyri and sulci). It is a very thin sheet of connective tissue that interfaces with the glial limitans superficialis but lacks capillaries itself.
In September 2020, the European Medicines Agency (EMA) endorsed the use of dexamethasone in adults and adolescents, from twelve years of age and weighing at least 40 kilograms (88 lb), who require supplemental oxygen therapy. Dexamethasone can be taken by mouth or given as an injection or infusion (drip) into a vein. In November 2020, the Public Health Agency of Canada's Clinical Pharmacology Task Group recommended dexamethasone for hospitalized patients requiring mechanical ventilation. Although dexamethasone, and other glucocorticoids, reduce mortality in COVID-19 they have also been associated with an increased risk of secondary infections, secondary infections being a significant issue in critically ill COVID-19 patients. The mechanism of action of dexamethasone involves suppression of late-stage interferon type I programs in severe COVID-19 patients.
== Military leaders == Rudolphus Ritzema (1758), officer during the American Revolutionary War Edward Antill (1762), colonel and military engineer of the Continental Army who fought in the Battle of Quebec Nicholas Fish (177-), American Revolutionary War officer John Doughty (1770), served as commanding general of the United States Army in 1784 Stephen Lush (1770), American Revolutionary War officer Robert Troup (1774), soldier, lawyer, jurist, roommate of Alexander Hamilton at King's College Samuel Auchmuty (1775), British general, commander-in-chief, Ireland and commander of the Madras Army Marinus Willett (1776), colonel of the Continental Army, leader of the Sons of Liberty and 48th mayor of New York City John Chrystie (1806), colonel of the United States Army during the War of 1812 Stephen Kearny* (1812), conqueror of California in the Mexican–American War Charles Wilkes (1818), leader of the United States Exploring Expedition to survey the Pacific Ocean; instigator of the Trent Affair during the American Civil War Philip Kearny (1833), United States Army officer Henry M. Judah* (1840), United States Army officer during the Mexican–American War and the American Civil War John Watts de Peyster* (1840), Civil War general, military critic and historian Edward E.
Oral mucosa heals faster than skin, suggesting that saliva may have properties that aid wound healing. Saliva contains cell-derived tissue factor, and many compounds that are antibacterial or promote healing. Salivary tissue factor, associated with microvesicles shed from cells in the mouth, promotes wound healing through the extrinsic blood coagulation cascade. The enzymes lysozyme and peroxidase, defensins, cystatins and an antibody, IgA, are all antibacterial. Thrombospondin and some other components are antiviral. A protease inhibitor, secretory leukocyte protease inhibitor, is present in saliva and is both antibacterial and antiviral, and a promoter of wound healing. Nitrates that are naturally found in saliva break down into nitric oxide on contact with skin, which will inhibit bacterial growth. Saliva contains growth factors such as epidermal growth factor, VEGF, TGF-β1, leptin, IGF-I, lysophosphatidic acid, hyaluronan and NGF, which all promote healing, although levels of EGF and NGF in humans are much lower than those in rats. In humans, histatins may play a larger role. As well as being growth factors, IGF-I and TGF-α induce antimicrobial peptides. Saliva also contains an analgesic, opiorphin. Licking will also tend to debride the wound and remove gross contamination from the affected area. In a recent study, scientists have confirmed through several experiments that the protein responsible for healing properties in human saliva is, in fact, histatin.
THC is a weak partial agonist at CB1 receptors, while CBD is a CB1 receptor antagonist. The CB1 receptor is found primarily in the brain as well as in some peripheral tissues, and the CB2 receptor is found primarily in peripheral tissues, but is also expressed in neuroglial cells. THC appears to alter mood and cognition through its agonist actions on the CB1 receptors, which inhibit a secondary messenger system (adenylate cyclase) in a dose-dependent manner. Via CB1 receptor activation, THC indirectly increases dopamine release and produces psychotropic effects. CBD also acts as an allosteric modulator of the μ- and δ-opioid receptors. THC also potentiates the effects of the glycine receptors. It is unknown if or how these actions contribute to the effects of cannabis.
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 synthetic peptide of 39 amino acids bearing a lipid side chain. Its size and architecture place it outside the small-molecule class, and laboratories generally handle it with the precautions used for biologic-like molecules.