body composition comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-11-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
化学修饰延长了分子在体内的停留时间,使较低频次的给药安排成为可能。脂肪酸侧链通过与白蛋白结合延缓清除,非天然氨基酸则降低酶解速率。这些修饰同时改变分子的溶解性与稳定性,需要在制剂设计和储存条件中一并考虑。修饰引入的免疫原性风险也属于开发过程中需要评估的项目。
该化合物处于临床试验阶段,尚未在多数地区取得上市许可。公开信息主要来自企业公告、学术会议摘要与试验注册平台记录,完整数据仍在逐步披露。关于长期疗效与安全性的判断,需要等待规模更大、随访更久的研究结果,目前不宜对最终结论作出预判。
Each receptor contributes a different physiological effect. Activation of the GLP-1 receptor slows gastric emptying and reduces appetite signaling in the brain. GIP receptor activity influences insulin secretion and lipid handling, while glucagon receptor stimulation raises energy use and fat oxidation. Combining these pathways is intended to produce weight loss beyond what single- or dual-receptor agonists achieve. Researchers attribute the observed potency to simultaneous engagement of all three targets, though the exact contribution of each receptor to overall effect remains under investigation.
Clinical development has advanced through phase 2 trials in adults with obesity and type 2 diabetes. Reported phase 2 results described substantial average weight reduction over roughly forty-eight weeks of weekly dosing. A phase 3 program is ongoing to confirm efficacy and assess long-term safety. Because the compound has not received regulatory approval, it is not available as a prescription product. Public discussion of retatrutide often conflates trial findings with marketed status, an important distinction when interpreting coverage of the topic.
Retatrutide is a synthetic peptide developed as a single molecule that activates three distinct hormone receptors: GLP-1, GIP, and glucagon. The compound carries the internal designation LY3437943 and was engineered by modifying the backbone of glucose-dependent insulinotropic polypeptide. Its sequence incorporates non-natural amino acids and a fatty acid side chain that extends circulation time. The triple-agonist design aims to combine appetite suppression, improved insulin response, and increased energy expenditure in one agent. Published reports describe it as an investigational product rather than an approved medicine.
| Property | Value | Notes |
|---|---|---|
| 分子类别 | 合成多肽 | 含非天然氨基酸与脂肪酸侧链 |
| 分子量 | 约 4.7 kDa | 多肽量级,精确值随计法而异 |
| 外观 | 白色至类白色冻干粉 | 常见冻干形态,供复溶使用 |
| 溶解性 | 易溶于水 | 复溶后为澄清至微乳光液体 |
| 常见同义词 | LY3437943 | 开发阶段使用的代号 |
瑞他鲁肽同时激活GLP-1受体、GIP受体和胰高血糖素受体,这三者均属于B类G蛋白偶联受体。受体激活后主要经cAMP信号通路传递效应。GLP-1成分与食欲抑制和胃排空延缓相关,GIP成分影响脂肪组织与胰岛素分泌,胰高血糖素成分则促进肝糖输出和能量消耗。各受体贡献的相对比例在人体中尚未完全量化。
该分子是经过结构修饰的合成肽,通过脂肪酸侧链与白蛋白结合,从而延长循环时间。皮下给药后,药物逐步释放并分布至组织。降解主要依赖蛋白酶,肾脏清除占次要地位。人体半衰期以天为单位,但准确数值随检测方法和个体差异而变;组织分布与受体占有率仍是开放问题。
Retatrutide is an investigational synthetic peptide engineered to activate three distinct hormone receptors within a single molecule. It targets the glucose-dependent insulinotropic polypeptide receptor, the glucagon-like peptide-1 receptor, and the glucagon receptor simultaneously. This triagonist design distinguishes it from earlier incretin-based compounds that act on one or two of these pathways. Structural modifications relative to native gut hormones extend its residence time in circulation. The molecule remains under clinical evaluation and is not approved for any indication.
Receptor activation produces downstream effects that differ by tissue. GLP-1 receptor signaling influences appetite regulation and insulin secretion in a glucose-dependent manner. GIP receptor activity contributes to metabolic handling of nutrients and may modulate adipose tissue. Glucagon receptor engagement raises energy expenditure and promotes hepatic lipid turnover, though the balance among these actions in humans is still being characterized. Preclinical models showed reductions in body weight and improved glycemic markers.
Clinical development has progressed through phase 2 trials in adults with obesity and type 2 diabetes, with phase 3 programs reported as ongoing. Reported outcomes include reductions in body weight and improvements in glycemic measures over defined treatment periods. Whether these effects translate into durable benefits after treatment ends remains an open question. Long-term safety data across broad populations are not yet complete, and regulatory decisions have not been announced.
Trial reports for this compound rely on a small set of repeated measures. Body weight is normally expressed as percent change from baseline at a fixed week, with absolute kilograms given secondarily. Glycemic endpoints include HbA1c, fasting glucose, and, in some protocols, continuous glucose monitoring summaries. Imaging endpoints such as MRI-derived proton density fat fraction quantify liver fat. Standardization matters because a percent change and a categorical responder analysis can tell different stories about the same dataset.
Body composition is assessed with dual-energy X-ray absorptiometry or comparable methods, which separate fat mass from lean mass. Reported losses include both compartments, and the ratio between them is a subject of ongoing analysis rather than a settled result. Waist circumference, blood pressure, and lipid panels are collected as supporting measures. Resting energy expenditure and substrate oxidation are measured in smaller mechanistic studies, where glucagon receptor activity is expected to matter. These substudies are typically short and small, so their findings carry wide uncertainty.
Two months after taking psilocybin, 79% of the participants reported moderately to greatly increased life satisfaction and sense of well-being. About 36% of participants also had a strong to extreme "experience of fear" or dysphoria (i.e., a "bad trip") at some point during the psilocybin session (which was not reported by any subject during the methylphenidate session); about one-third of these (13% of the total) reported that this dysphoria dominated the entire session. These negative effects were reported to be easily managed by the researchers and did not have a lasting negative effect on the subject's sense of well-being. A follow-up study 14 months later confirmed that participants continued to attribute deep personal meaning to the experience. Almost a third of the subjects reported that the experience was the single most meaningful or spiritually significant event of their lives, and over two-thirds reported it was among their five most spiritually significant events. About two-thirds said the experience increased their sense of well-being or life satisfaction. Even after 14 months, those who reported mystical experiences scored on average 4 percentage points higher on the personality trait of Openness/Intellect; personality traits are normally stable across the lifespan for adults. Likewise, in a 2010 web-based questionnaire study designed to investigate user perceptions of the benefits and harms of hallucinogenic drug use, 60% of the 503 psilocybin users reported that their use of psilocybin had a long-term positive impact on their sense of well-being.
Center for Strategic and International Studies (CSIS) specialist Clayton Seigle said oil companies sought stability in Venezuela above all else, adding that the outlook for US interests in the country remained uncertain. Another CSIS expert, Christopher Hernandez-Roy, said Trump's reluctance to engage in full regime change was driven by fear of chaos, noting that, aside from Maduro's removal, the current regime remained unchanged. American political analyst David Rothkopf described President Trump's conduct as the "Putinization of US foreign policy". Analysts Ryan C. Berg and Alexander B. Gray stated that the action showed a robust commitment to Trump's 2025 National Security Strategy (NSS) and a desire to increase preeminence in the Western Hemisphere, in turn signaling a "global reestablishment of deterrence" to countries such as China, alluding to the latter's investments in Venezuela. Atlantic Council Counterterrorism Project head Alex Plitsas urged an orderly transition, warning that instability in Venezuela could lead to political fragmentation and criminal violence involving colectivo gangs; Berg elaborated that any systemic change would likely be lengthy, while reinforcing the Trump administration's "America First" agenda. Indian political analyst Brahma Chellaney argued that while the legal framing (drug trafficking charges) resembles the 1989 invasion of Panama and the seizure of Manuel Noriega, the actual methodology and strategic narrative align more closely with the 2003 invasion of Iraq.
Materials in certain cosmetics such as sun cream, moisturizer, and deodorant may have potential benefits from the use of nanochemistry. Manufacturers are working to increase the effectiveness of various cosmetics by facilitating oil nanoemulsion. These particles have extended the boundaries in managing wrinkling, dehydrated, and inelastic skin associated with aging. In sunscreen, titanium dioxide and zinc oxide nanoparticles prove to be effective UV filters but can also penetrate through skin. These chemicals protect the skin against harmful UV light by absorbing or reflecting the light and prevent the skin from retaining full damage by photoexcitation of electrons in the nanoparticle.
A micro-computed tomography (Micro CT) scan of the bone done by Fiona Brock at Cranfield University helped to reveal that the specimen had acid etching and pitting on its surface indicating it may have passed through the digestion system of an animal, likely a hyena. Direct radiocarbon dating estimated the specimen to be more than 50,000 years old, and the sequencing of its mitochondrial DNA (mtDNA) at the Max Planck Institute for Evolutionary Anthropology, showed that Denisova 11 had a sequence consistent with a Neanderthal origin. Further work by scientists at the Max Planck Institute for Evolutionary Anthropology, where previous samples of Denisovan DNA had been sequenced and analyzed uncovered further key evidence relating the specimen Viviane Slon, Svante Pääbo, and others, uncovered Denny's mixed ancestry by confirming that her mitochondrial DNA, inherited from her mother, came from Neanderthal ancestry and finding that the portion of her nuclear DNA inherited from her father was Denisovan. The publication of their results in 2018 provided the first direct evidence of archaic human interbreeding. It has been called a "landmark find" that is reshaping our understanding of how hominins interacted and could help rewrite the story of archaic and modern humans. According to population geneticist Pontus Skoglund from Harvard Medical School, currently at the Francis Crick Institute in London, "To find a first-generation person of mixed ancestry from [Neanderthal and Denisovan groups] is absolutely extraordinary. ...
Sources: en.wikipedia.org
Potentiation of GABAA receptor activity (by kavain, dihydrokavain, methysticin, dihydromethysticin, and yangonin). Inhibition of the reuptake of norepinephrine (by kavain and methysticin) and possibly also of dopamine (by kavain and desmethoxyyangonin). Binding to the CB1 receptor (by yangonin). Inhibition of voltage-gated sodium channels and voltage-gated calcium channels (by kavain and methysticin). Monoamine oxidase B reversible inhibition (by all six of the major kavalactones). Methanolic leaf extracts of Hawaiian kava cultivars showed stronger binding inhibition to several CNS receptors—including GABAA, dopamine D2, opioid (μ, δ), and histamine (H1, H2)—than root extracts, suggesting that compounds beyond the main kavalactones may contribute to the pharmacological effects of kava leaves.
=== Depression === Selegiline is used as an antidepressant in the treatment of major depressive disorder (MDD). Both the oral selegiline and transdermal selegiline patch formulations are used in the treatment of depression. However, oral selegiline is not approved for depression and is used off-label for this indication, while the transdermal patch is specifically licensed for treatment of depression. Both standard clinical doses of oral selegiline (up to 10 mg/day) and higher doses of oral selegiline (e.g., 30 to 60 mg/day) have been used to treat depression, with the lower doses selectively inhibiting MAO-B and the higher doses producing dual inhibition of both MAO-A and MAO-B. Unlike oral selegiline, transdermal selegiline bypasses first-pass metabolism, thereby avoiding inhibition of gastrointestinal and hepatic MAO-A and minimizing the risk of food and drug interactions, whilst still allowing for selegiline to reach the brain and inhibit MAO-B. A 2023 systematic review and meta-analysis evaluated the effectiveness and safety of selegiline in the treatment of psychiatric disorders including depression. It included both randomized and non-randomized published clinical studies. The meta-analysis found that selegiline was more effective than placebo in terms of reduction in depressive symptoms (SMDTooltip standardized mean difference = −0.96, k = 10, n = 1,308), response rates for depression improvement (RRTooltip risk ratio = 1.61, k = 9, n = 1,238), and response rates for improvement of depression with atypical features (RR = 2.23, k = 3, n = 136).
14 March – SpaceX successfully launches the Starship spacecraft, but loses the rocket upon re-entering the atmosphere. 19 March Scientists demonstrate a wireless network of 78 tiny sensors able to gather data from the brain, with potential to be scaled up to thousands of such devices. Researchers with the National Severe Storms Laboratory, Storm Prediction Center, CIWRO, and the University of Oklahoma's School of Meteorology publish a paper where they state, ">20% of supercell tornadoes may be capable of producing EF4–EF5 damage" and that "the legacy F-scale wind speed ranges may ultimately provide a better estimate of peak tornado wind speeds at 10–15 m AGL for strong–violent tornadoes and a better damage-based intensity rating for all tornadoes" and also put the general 0–5 ranking scale in question. 20 March – The removal of HIV from infected cells using CRISPR gene editing technology is reported. 26 March – A study outlines identified ecological pandemic prevention measures for policy frameworks.
Sources: en.wikipedia.org
==== Selenium pollution ==== Selenium pollution of water systems may result whenever new agricultural runoff courses through normally dry, undeveloped lands. This process leaches natural soluble selenium compounds (such as selenates) into the water, which may then be concentrated in new "wetlands" as the water evaporates. High selenium levels produced in this fashion have been found to have caused certain congenital disorders in wetland birds.
The periplasm is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the bacterial outer membrane called the periplasmic space in Gram-negative (more accurately "diderm") bacteria. Using cryo-electron microscopy it has been found that a much smaller periplasmic space is also present in Gram-positive bacteria (more accurately "monoderm"), between cell wall and the plasma membrane. The periplasm may constitute up to 40% of the total cell volume of gram-negative bacteria, but is a much smaller percentage in gram-positive bacteria.
Following concerns over the fate of 7-Eleven Speak Out Wireless customers, Quickie offered the option for SpeakOut customers to port into the Good2Go mobile provider. SpeakOut subsequently offered online sales as an option, and continues to offer Ottawa-based phone numbers to new and existing customers.
Sources: en.wikipedia.org
指同一个分子能激活 GIP、GLP-1 和胰高血糖素三类受体。它与只激活一到两种受体的同类分子在设计思路上有所区别。这种设计的目的在于覆盖更多代谢调节通路。
天然肽类在体内容易被酶解并快速清除。脂肪酸侧链与非天然氨基酸可以延缓清除、降低酶解速率。修饰后的分子因此更适合较长间隔的给药安排。
公开资料主要来自临床阶段的报告与注册平台记录。这些材料提供的是阶段性信息,而非最终结论。完整的安全性与有效性数据仍在积累中。
Retatrutide is an investigational peptide that activates the GLP-1, GIP, and glucagon receptors at the same time. It is being studied for obesity and type 2 diabetes and has not been approved for clinical use. The internal code LY3437943 refers to the same molecule.