Everything below concerns albumin binding. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
溶解操作一般使用注射用水或适宜的水性缓冲液，必要时加入少量助溶剂以改善溶解速度，但应避免剧烈涡旋振荡，因为剪切力可能促进聚集。配制后的溶液在冷藏条件下的稳定时间通常短于固体形态，具体时限取决于浓度、缓冲体系与容器材质。是否加入防腐成分，则取决于用途是否为多次取样。
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。
Identity and purity are usually established with reversed-phase high-performance liquid chromatography for the main peak and with mass spectrometry for the observed molecular mass. Peptide mapping after enzymatic digestion confirms the primary sequence, while amino acid analysis provides a quantitative composition check. Size-exclusion chromatography and ion-exchange chromatography are used to look for aggregates and charge variants. Water content, residual solvents, and counter-ion content are measured separately, since a lyophilised powder is often reported on an as-is basis unless a correction is applied.
Research-grade material circulates through suppliers that differ widely in documentation and testing practice, so a certificate of analysis is a starting point rather than proof of quality. Independent verification typically repeats chromatographic purity and mass confirmation on the received lot, and compares results against a retained reference standard. Regulatory status varies by jurisdiction, and a substance cleared as a medicine is not interchangeable with a research chemical of the same name. Open questions include how closely non-pharmaceutical lots match approved material in impurity profile and in aggregate content.
| 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 |
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its sequence is related to human glucose-dependent insulinotropic polypeptide, with modifications that include a C-terminal extension and a C20 fatty diacid joined through a linker. Those changes raise the molecule's affinity for serum albumin, which slows renal filtration and lengthens the time it stays in circulation. The free base has an average molecular mass near 4813.5 daltons. The compound is made by solid-phase peptide synthesis followed by chromatographic purification.
At the receptor level, tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. Both belong to the class B family of G protein-coupled receptors and signal largely through cyclic AMP accumulation. The compound binds the two receptors with differing affinity, and the pattern of signaling at each site is described in the literature as biased rather than simply proportional to occupancy. Tissues carrying these receptors include pancreatic islets, adipose tissue, the central nervous system, and the gastrointestinal tract. The relative weight of each receptor population in producing metabolic effects continues to be studied.
Published work supports the view that engaging two incretin receptors produces changes in glucose handling and body weight larger than those seen with single-receptor activation. Why that difference arises is not fully settled. Open questions include how much of the observed weight effect depends on central versus peripheral signaling, and whether the two receptors form interacting complexes. Most reported findings come from controlled trials and animal models, and translation between species is imperfect. Further research is expected to refine these points over time.
The GIP receptor is expressed in pancreatic islets, adipose tissue, and the central nervous system, while GLP-1 receptors are found in pancreatic islets, the gastrointestinal tract, and the brain. Activation of both receptors can enhance glucose-dependent insulin secretion and reduce glucagon release. The relative contribution of each receptor to the overall pharmacological effect remains an area of ongoing investigation. Preclinical studies suggest that GIP receptor agonism may modulate appetite and energy balance, but the precise mechanisms in humans are not fully established.
In clinical research, tirzepatide has been studied in randomized controlled trials for glycemic control and body weight reduction. These trials typically measure changes in hemoglobin A1c and body weight over periods of several months. The drug is administered by subcutaneous injection, and its pharmacokinetic profile supports once-weekly dosing. Post-marketing surveillance continues to evaluate long-term outcomes and rare adverse events.
Tirzepatide is a synthetic peptide that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. The molecule contains 39 amino acids and features a C20 fatty diacid moiety attached via a linker, which promotes albumin binding and extends its circulating half-life. Its sequence incorporates non-natural amino acids and modifications that reduce susceptibility to degradation by dipeptidyl peptidase-4. This dual receptor activity distinguishes it from selective GLP-1 receptor agonists.
Peptide-based pharmaceutical products such as tirzepatide require controlled temperature management to preserve structural integrity. Manufacturer labeling generally specifies refrigeration at 2 to 8 degrees Celsius before first use, with protection from light and freezing. Exposure to repeated temperature cycling can promote aggregation or deamidation, which alters the analytical profile even when the visible solution appears unchanged. Once a product is in use, the permitted storage window and temperature range are defined by the specific labeled presentation rather than by general peptide rules.
Identity and purity assessment of tirzepatide relies primarily on reversed-phase high-performance liquid chromatography coupled with ultraviolet detection. Mass spectrometry, often in electrospray ionization mode, confirms the molecular mass and detects sequence-related impurities. Peptide mapping after enzymatic digestion provides residue-level confirmation of the backbone. Each method addresses a different question: chromatography for purity and related substances, mass measurement for identity, and mapping for sequence fidelity. No single technique covers all three.
Research and analytical settings increasingly require documentation of peptide origin and chain of custody. Certificate of analysis documents typically report purity by chromatographic area, mass confirmation, appearance, and residual solvent or counterion content. Independent verification by an accredited laboratory is common when a material will be used in a regulated study. Open questions remain about how well compendial methods transfer between laboratories, and about which impurity thresholds are meaningful for materials not intended for clinical use.
=== Pharmacodynamics === As a glucocorticoid, dexamethasone is an agonist of the glucocorticoid receptor (GR). It is highly selective for the GR over the mineralocorticoid receptor (MR), and in relation to this, has minimal mineralocorticoid activity. This is in contrast to endogenous corticosteroids like cortisol, which bind to and activate both the GR and the MR. Dexamethasone is 25 times more potent than hydrocortisone (cortisol) as a glucocorticoid. Its affinity (Ki) for the GR was about 1.2 nM in one study. The activation of the GR by dexamethasone results in dose-dependent suppression of the hypothalamic–pituitary–adrenal axis (HPA axis) and of production of endogenous corticosteroids by the adrenal glands, thereby reducing circulating endogenous concentrations of corticosteroids like cortisol and corticosterone. Dexamethasone poorly penetrates the blood–brain barrier into the central nervous system due to binding to P-glycoprotein. However, higher doses of dexamethasone override the export capacity of P-glycoprotein and enter the brain to produce central activation of GRs. In conjunction with the suppression of endogenous corticosteroids by dexamethasone, this results in skewed ratios of activation of peripheral versus central GRs as well as skewed ratios of activation of GRs versus MRs when compared to non-synthetic corticosteroids. These differences can have significant clinical relevance.
Knopf Lawrence Van Gelder (1953), editor of the Arts and Leisure weekly section of The New York Times Max Frankel (1952), Pulitzer Prize winning executive editor of The New York Times Richard Locke (1962), critic, essayist and first editor of new incarnation of Vanity Fair magazine Leslie Pockell (1962), editor for Grand Central Publishing Carey Winfrey (1963), editor-in-chief of Smithsonian magazine 2001–2011 Clark Hoyt (1964), public editor of The New York Times Myron Magnet (1966), editor of City Journal 1994–2006, National Humanities Medal recipient Chilton Williamson (1969), editor of the Chronicles magazine for the Rockford Institute Richard Snow (1970), editor of American Heritage magazine Paul Spike (1970), first American editor of Punch Leon Wieseltier (1974), literary editor, The New Republic Scott McConnell (1975), founding editor of The American Conservative Dean Baquet (1978), Pulitzer Prize-winning executive editor of The New York Times John Glusman (1978), editor-in-chief of W. W.
Special state certification in the United States is required only in four states: California, Washington, Nevada, and Louisiana. A phlebotomist can become nationally certified through many different organizations. However, California currently only accepts national certificates from six agencies. These include the American Certification Agency (ACA), American Medical Technologists (AMT), American Society for Clinical Pathology (ASCP), National Center for Competency Testing/Multi-skilled Medical Certification Institute (NCCT/MMCI), National Credentialing Agency (NCA), and National Healthcareer Association (NHA). These and other agencies such as the American Society of Phlebotomy Technicians also certify phlebotomists outside the state of California. To qualify to sit for an examination, candidates must complete a full phlebotomy course and provide documentation of clinical or laboratory experience.
== Uses == TCFH itself is a common reagent used in the preparation of uronium and guanidinium salts used for amide bond formation and peptide synthesis, such as HATU. Amide bond formation with TCFH can be performed in a wide range of organic solvents, most commonly acetonitrile, but also water and in the solid state. Reactions typically require an added Brønsted base, and a wide range can be employed including N,N-diisopropylethylamine (DIPEA). In reactions of carboxylic acids with TCFH and a weakly Lewis basic amine like DIPEA, formation of an acid chloride or anhydride as the active acylating agent occurs. Use of N-methylimidazole (NMI) as a base, with both Brønsted and Lewis basic properties, provides some unique advantages. Reactions of carboxylic acids with TCFH and a strongly Lewis basic amine like NMI lead to in situ formation of an N-acyl imidazolium ion (NAI) as the active acylating agent.
Sources: en.wikipedia.org
=== Nepal === The executive director of the state-run Nepal Oil Corporation announced that, as of March 13, authorities would refill only half of consumers' empty cylinders to lengthen liquid petroleum stockpiles.
Before the inexpensive production of gelatin and other competing products, isinglass was used in confectionery and desserts such as fruit jelly and blancmange. Isinglass finings are widely used as a processing aid in the British brewing industry to accelerate the fining, or clarification, of beer. It is used particularly in the production of cask-conditioned beers, although many cask ales are available which are not fined using isinglass. The finings flocculate the live yeast in the beer into a jelly-like mass, which settles to the bottom of the cask. Left undisturbed, beer will clear naturally; the use of isinglass finings accelerates the process. Isinglass is sometimes used with an auxiliary fining, which further accelerates the process of sedimentation. Non-cask beers that are destined for kegs, cans, or bottles are often pasteurised and filtered. The yeast in these beers tends to settle to the bottom of the storage tank naturally, so the sediment from these beers can often be filtered without using isinglass. However, some breweries still use isinglass finings for non-cask beers, especially when attempting to repair bad batches. Many vegetarians consider beers that are processed with these finings (such as most cask-conditioned ales in the UK) to be unsuitable for vegetarian diets (although acceptable for pescetarians). According to global data in 2018, along with low-calorie beer and gluten-free beer, beers that are acceptable for strict vegetarians are expected to grow in demand in the coming years.
Colonel Sanders was a key component of KFC advertising until his death in 1980. Despite his death, Sanders remains a key icon of the company as an "international symbol of hospitality". Early official slogans for the company included "North America's Hospitality Dish" (from 1956) and "We fix Sunday dinner seven nights a week". The "finger lickin' good" slogan was used from 1956 and went on to become one of the best-known slogans of the 20th century. The trademark expired in the US in 2006. The first KFC logo was introduced in 1952 and featured a "Kentucky Fried Chicken" typeface and a logo of the Colonel. In 1962, Dave Thomas took Colonel Sanders' bucket and turned it into a sign that revolved in a circular motion in front of almost every American KFC outlet. Advertising played a key role at KFC after it was sold by Sanders and the company began to advertise on US television with a budget of US$4 million in 1966. In order to fund nationwide advertising campaigns, the Kentucky Fried Chicken Advertising Co-Op was established, giving franchisees 10 votes and the company three when deciding on budgets and campaigns. In 1969, KFC hired its first national advertising agency, Leo Burnett. A notable Burnett campaign in 1972 was the "Get a bucket of chicken, have a barrel of fun" jingle, performed by Barry Manilow. By 1976, KFC was one of the largest advertisers in the US.
Sources: en.wikipedia.org
== Clinical significance == Furin is one of the proteases responsible for the proteolytic cleavage of HIV envelope polyprotein precursor gp160 to gp120 and gp41 prior to viral assembly. This protease is also thought to play a role in tumor progression. The use of alternate polyadenylation sites has been found for the FURIN gene. Furin is enriched in the Golgi apparatus, where it functions to cleave other proteins into their mature/active forms. Furin cleaves proteins just downstream of a basic amino acid target sequence (canonically, Arg-X-(Arg/Lys) -Arg'). In addition to processing cellular precursor proteins, furin is also used by a number of pathogens. For example, the envelope proteins of viruses such as HIV, influenza, dengue fever, several filoviruses including ebola and marburg virus, and the spike protein of SARS-CoV-2, must be cleaved by furin or furin-like proteases to become fully functional. When SARS-CoV-2 virus is being synthesized in an infected cell, furin or furin-like proteases cleave the spike protein into two portions (S1 and S2), which remain associated. Anthrax toxin, Pseudomonas exotoxin, and papillomaviruses must be processed by furin during their initial entry into host cells. Inhibitors of furin are under consideration as therapeutic agents for treating anthrax infection. Furin is regulated by cholesterol and substrate presentation. When cholesterol is high, furin traffics to GM1 lipid rafts. When cholesterol is low, furin traffics to the disordered region. This is speculated to contribute to cholesterol and age dependent priming of SARS-CoV.
The four-engined Fw 200 airliner flew nonstop between Berlin and New York City on 10 August 1938, making the journey in 24 hours and 56 minutes. It was the first aircraft to fly that route without stopping. The return trip on 13 August 1938, took 19 hours and 47 minutes. These flights are commemorated with a plaque in the Böttcherstraße street of Bremen. The Fw 190 Würger (Shrike/butcher-bird), designed from 1938 on, and produced in quantity from early 1941–1945, was a mainstay single-seat fighter for the Luftwaffe during World War II.
== Other uses == Gautampura Road railway station, Ujjain, Madhya Pradesh, India GP Strategies Corporation, an American consulting firm (NYSE ticker:GPX) GPX Tire Corporation, an American company producing tires Grand Prix (disambiguation), French for "Grand Prize", used in several sports
== Mechanism of action == As studied mainly on cisplatin, but presumably for other members as well, platinum-based antineoplastic agents cause crosslinking of DNA as monoadduct, interstrand crosslinks, intrastrand crosslinks or DNA protein crosslinks. Mostly they act on the adjacent N-7 position of guanine, forming a 1, 2 intrastrand crosslink. The resultant crosslinking inhibits DNA repair and/or DNA synthesis. This mechanism leads to specific patterns of damage in DNA, which can kill cancer cells but can also increase the risk of secondary tumors developing. Platinum(IV) prodrugs have also been investigated as a strategy to overcome resistance to platinum chemotherapy. In preclinical models of prostate cancer, the cisplatin prodrug Platin-L inhibited fatty acid oxidation through interaction with CPT1A and showed activity against cisplatin-resistant tumors. Platinum-based antineoplastic agents are sometimes described as "alkylating-like" due to similar effects as alkylating antineoplastic agents, although they do not have an alkyl group.
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 normally kept frozen, desiccated, and away from light, with brief warming to room temperature before opening to limit condensation. Repeated freeze-thaw cycles are avoided because they stress the peptide. Once in solution, the material is held cold and used promptly.