A practical reference on trans-3-hexenoyl: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-06-14. Anything still debated is marked as such rather than presented as settled.
监管记录显示,特沙莫瑞林于 2010 年在美国首次获得批准,用于人类免疫缺陷病毒感染相关的脂肪营养不良患者。批准依据来自降低内脏脂肪的临床试验,而非体重或瘦体重的普遍改善。后续出现了不同制剂版本,但其核心适应症保持一致。关于长期心血管结局和死亡率影响,现有证据仍不充分。
在临床研究之外,特沙莫瑞林常被讨论为生长激素分泌促进剂,但这一说法需要限定。它并不等同于生长激素本身,也不属于普通减重药物。部分研究关注其减少腹部脂肪和改善脂质谱的潜力,另一些研究则关注胰岛素抵抗和 IGF-1 升高等信号。这些效应的临床意义仍在评估中,尚未形成统一结论。
Whether the drug improves hard clinical outcomes is not settled. No completed trial has shown a reduction in heart attacks or strokes among treated patients, although a dedicated cardiovascular outcomes study has been discussed in the literature. Investigators have also examined hepatic fat in people with HIV and fatty liver disease, cognitive measures in small cohorts, and changes in bone density. Regulatory labeling emphasizes monitoring of insulin-like growth factor 1 because supraphysiologic levels raise questions about tissue growth, and the clinical significance of that signal remains an open question rather than a demonstrated harm.
Binding of tesamorelin to the growth hormone-releasing hormone receptor on anterior pituitary somatotrophs activates a Gs protein pathway, raises cyclic AMP, and triggers release of stored growth hormone into the bloodstream. Because the analogue resists dipeptidyl peptidase-4, its plasma residence time exceeds that of native GHRH, producing a larger and more sustained secretory signal. The released growth hormone then acts on the liver and peripheral tissues to raise insulin-like growth factor 1, which feeds back on the hypothalamus and pituitary. This axis explains both the intended effects on fat distribution and the biological markers used to track them.
| Property | Value | Notes |
|---|---|---|
| 分子类型 | 合成肽 | 含 44 个氨基酸残基的 GHRH 类似物 |
| N 端修饰 | 反式-3-己烯酰基 | 用于抵抗二肽基肽酶 IV 降解 |
| 首次批准 | 2010 年,美国 | 用于 HIV 相关脂肪营养不良 |
| 作用靶点 | 生长激素释放激素受体 | 位于垂体前叶 |
| 主要研究终点 | 内脏脂肪变化 | 非总体重或瘦体重 |
Development work on the compound, originally designated TH9507, focused on conditions in which reduced growth hormone signaling is thought to contribute to altered body composition. The United States Food and Drug Administration approved it in 2010 for the treatment of excess visceral abdominal fat in adults with human immunodeficiency virus infection and lipodystrophy. Later research examined other populations, including adults with mild cognitive impairment, where a large trial did not meet its primary endpoints. This mixed record illustrates how a single mechanism can produce clear effects in one setting and inconclusive results in another.
Several related peptides act on the same receptor, including sermorelin, a shorter GHRH fragment, and modified analogs such as CJC-1295 and modified GRF(1-29) that are common in research settings rather than approved products. Tesamorelin differs from growth hormone itself in that it acts upstream, prompting the pituitary to release the hormone through physiological signaling rather than supplying it directly. Terminology in the literature distinguishes GHRH analogs, growth hormone secretagogues, and recombinant growth hormone, although popular discussion often blurs these categories together. Precise naming matters when comparing study results.
Research supply is often accompanied by a certificate of analysis listing chromatographic purity, mass confirmation, and storage conditions. Laboratories compare that document with an independent test when material is intended for bench work, since certificates describe a batch rather than an individual vial. Published studies usually state the source and purity of the peptide because small differences in purity can shift measured activity. Full analytical validation is rarely reported, which leaves batch-to-batch comparability an open question.
The peptide is supplied as a lyophilized powder in single-use vials and is normally kept refrigerated between two and eight degrees Celsius, protected from light. Once dissolved, the solution is handled carefully because peptide bonds and the acyl modification can degrade under warm or alkaline conditions. Vials are inspected for cracks, and the powder is checked for color and uniformity before handling. Temperature excursions during shipping are a frequent reason for quality questions.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
However, in doubles, he and partner, Andrey Golubev, reached the semifinals where they lost to eventual champions John Isner and Jack Sock. Seeded second at the Miami Open, he reached the quarterfinals where he lost to sixth seed, world No. 8, and eventual finalist, Casper Ruud, in three sets. Zverev started his clay-court season at the Monte-Carlo Masters. Seeded second, he reached the semifinals after beating ninth seed and world No. 12, Jannik Sinner, in the quarterfinals in a three-set thriller. He lost in the semifinals to third seed, world No. 5, defending champion, and eventual champion, Stefanos Tsitsipas, in straight sets. As the top seed at the BMW Open in Munich, he was upset in the second round by world No. 70 and eventual champion, Holger Rune. Seeded second at the Madrid Open, he returned to defend his title. He reached the semifinals with a straight set win over eighth seed and world No. 10, Félix Auger-Aliassime, in the quarterfinals, after a tough three sets match win over Marin Čilić in the second round and Lorenzo Musetti's retirement in the third round due to a leg injury. In the semifinals, he took revenge on fourth seed, world No. 5, two-time Monte-Carlo champion, and 2019 finalist, Stefanos Tsitsipas, to reach his third final at this Masters 1000 event. He improved his ATP Head2Head record to 4–7 against Tsitsipas, earning his first clay-court win against him in the process. In the final, he was defeated by seventh seed and world No. 9, Carlos Alcaraz.
=== Prochirality and three-point attachment === The concept of prochirality is necessary for understanding some aspects of enzyme stereospecificity. Ogston pointed out that when a symmetrical molecule is placed in an asymmetric environment, such as the surface of an enzyme, supposedly identically placed groups become distinguishable. In this way he showed that earlier exclusion of non-chiral citrate as a possible intermediate in the tricarboxylate cycle was mistaken. A coffee mug with one handle is an everyday example of a prochiral object. If it is placed in an achiral corrosive liquid, such as a concentrated acid, then the left and right-hand sides will be corroded equally because there is nothing to distinguish them. However, if the mug is held in a person's right hand it is easy to drink out of the left-hand side but difficult to drink out of the right-hand side. In other words, an achiral environment such as an acid cannot distinguish between the two sides of a prochiral, but a chiral object like a person can. Thus a chiral enzyme such as aconitase can act differently on two apparently equivalent groups on a prochiral molecule, so citrate can be an intermediate in the tricarboxylate cycle.
=== Normal tissue structure and wound response === Normal tissues consist of parenchymal cells and stromal cells. The parenchymal cells are the functional units of an organ. In contrast, the stromal cells provide the structure of the organ and secrete extracellular matrix as supportive, connective tissue. In normal epithelial tissues, epithelial cells, or parenchymal cells of epithelia, are highly organized, polar cells. These cells are separated from stromal cells by a basement membrane that prevents these cell populations from mixing. A mixture of these cell types is recognized, normally, as a wound, as in the example of a cut to the skin. Metastasis is an example of a disease state in which a breach of the basement membrane barrier occurs.
Blood doping agents increase the oxygen-carrying capacity of blood beyond the individual's natural capacity. They are used in endurance sports like long-distance running, cycling, and Nordic skiing. Recombinant human erythropoietin (rhEPO) is one of the most widely known drugs in this class. The Athlete Biological Passport is the only indirect testing method for detection of blood doping.
dehydrogenase, glyceraldehyde phosphate (nicotinamide adenine dinucleotide phosphate) (phosphorylating) GAPDH glyceraldehyde phosphate dehydrogenase (nicotinamide adenine dinucleotide phosphate) (phosphorylating) glyceraldehyde-3-phosphate dehydrogenase (NADP) (phosphorylating) NADP-dependent glyceraldehyde phosphate dehydrogenase NADP-glyceraldehyde phosphate dehydrogenase NADP-glyceraldehyde-3-phosphate dehydrogenase NADP-triose phosphate dehydrogenase triosephosphate dehydrogenase (NADP)
Sources: en.wikipedia.org
The optical lens has been playing a critical role in almost all areas of science and technology since its invention about 3000 years ago. With the advances in micro- and nanofabrication techniques, continued miniaturization of the conventional optical lenses has always been requested for various applications such as communications, sensors, data storage and a wide range of other technology-driven and consumer-driven industries. Specifically, ever smaller sizes, as well as thinner thicknesses of micro lenses, are highly needed for subwavelength optics or nano-optics with extremely small structures, particularly for visible and near-IR applications. Also, as the distance scale for optical communications shrinks, the required feature sizes of micro lenses are rapidly pushed down. Recently, the excellent properties of newly discovered graphene oxide provide novel solutions to overcome the challenges of current planar focusing devices. Specifically, giant refractive index modification (as large as 10^-1), which is one order of magnitude larger than the current materials, between graphene oxide (GO) and reduced graphene oxide (rGO) have been demonstrated by dynamically manipulating its oxygen content using the direct laser writing (DLW) method. As a result, the overall lens thickness can be potentially reduced by more than ten times. Also, the linear optical absorption of GO is found to increase as the reduction of GO deepens, which results in transmission contrast between GO and rGO and therefore provides an amplitude modulation mechanism.
The Parliamentary Commissioner for Standards launches an investigation into Democratic Unionist Party MP Sammy Wilson for an alleged breach of lobbying rules after he failed to declare an interest when tabling a question on the Turkish Republic of Northern Cyprus, and following a visit to the area. 16 November – The SNP's National Executive Committee proposes cutting the number of staff at its headquarters from 26 to 16. Ruth Maguire, MSP for Cunninghame South, announces she will not seek re-election at the 2026 Scottish Parliament election because she is to undergo treatment for cancer. Protesters gather outside Welsh Labour's party conference to oppose changes to inheritance tax for farmers outlined in the October budget as Prime Minister Sir Keir Starmer defends the government's changes. 17 November – Sir Ed Davey, the leader of the Liberal Democrats, says that Jane Dodds, who leads the party in Wales, should reflect on her position after a report found she made a "grave error of judgement" in her handling of a sexual abuse scandal when she worked for the Church of England. 18 November – At the 2024 G20 Rio de Janeiro summit, Starmer holds talks with Chinese president Xi Jimping and emphasises the importance of a "strong UK–China relationship" for both countries. 19 November – Scottish Labour leader Anas Sarwar says his party will expand the eligibility for winter fuel payments in Scotland if they win the 2026 Scottish Parliament election.
Large AGE proteins unable to enter the Bowman's capsule are capable of binding to receptors on endothelial and mesangial cells and to the mesangial matrix. Activation of RAGE induces production of a variety of cytokines, including TNFβ, which mediates an inhibition of metalloproteinase and increases production of mesangial matrix, leading to glomerulosclerosis and decreasing kidney function in patients with unusually high AGE levels. Peptides and free adducts, the only breakdown products of AGE that are suitable for urinary excretion, are more aggressive than the AGE proteins from which they are derived, and they can perpetuate related pathology in people with diabetes, even after hyperglycemia has been brought under control.
Depleted uranium (DU), also referred to in the past as Q-metal, depletalloy, or D-38, is uranium with a lower content of the fissile isotope 235U than natural uranium. The less radioactive and non-fissile 238U is the main component of depleted uranium. It is antonymous to "enriched uranium". Uranium is notable for the extremely high density of its metallic form: at 19.1 grams per cubic centimetre (0.69 lb/cu in), uranium is 68.4% more dense than lead. Because depleted uranium has nearly the same density as natural uranium but far less radioactivity, it is desirable for applications that demand high mass without added radiation hazards. Civilian uses include counterweights in aircraft, radiation shielding in medical radiation therapy, research and industrial radiography equipment, and containers for transporting radioactive materials. Military uses include armor plating and armor-piercing projectiles. The use of DU in ammunitions is controversial because of concerns about potential long-term health effects. Normal functioning of the kidney, brain, liver, heart, and numerous other systems can be affected by exposure to uranium, a toxic metal. It is only weakly radioactive because of the long radioactive half-life of 238U (4.468 billion years) and the low amounts of 234U (half-life about 246,000 years) and 235U (half-life 700 million years). The biological half-life (the average time it takes for the human body to eliminate half the amount in the body) for uranium is about 15 days.
Sources: en.wikipedia.org
Because silent mutations do not alter protein function they are often treated as though they are evolutionarily neutral. Many organisms are known to exhibit codon usage biases, suggesting that there is selection for the use of particular codons due to the need for translational stability. Transfer RNA (tRNA) availability is one of the reasons that silent mutations might not be as silent as conventionally believed. There is a different tRNA molecule for each codon. For example, there is a specific tRNA molecule for the codon UCU and another specific for the codon UCC, both of which code for the amino acid serine. In this instance, if there was a thousand times less UCC tRNA than UCU tRNA, then the incorporation of serine into a polypeptide chain would happen a thousand times more slowly when a mutation causes the codon to change from UCU to UCC. If amino acid transport to the ribosome is delayed, translation will be carried out at a much slower rate. This can result in lower expression of a particular gene containing that silent mutation if the mutation occurs within an exon. Additionally, if the ribosome has to wait too long to receive the amino acid, the ribosome could terminate translation prematurely.
== Size and contents == The genomes of viruses and prokaryotes encode a relatively well-defined proteome as each protein can be predicted with high confidence, based on its open reading frame (in viruses ranging from ~3 to ~1000, in bacteria ranging from about 500 proteins to about 10,000). However, most protein prediction algorithms use certain cut-offs, such as 50 or 100 amino acids, so small proteins are often missed by such predictions. In eukaryotes this becomes much more complicated as more than one protein can be produced from most genes due to alternative splicing (e.g. human genome encodes about 20,000 proteins, but some estimates predicted 92,179 proteins out of which 71,173 are splicing variants). Association of proteome size with DNA repair capability The concept of "proteomic constraint" is that DNA repair capacity is positively correlated with the information content of a genome, which, in turn, is approximately related to the size of the proteome. In bacteria, archaea and DNA viruses, DNA repair capability is positively related to genome information content and to genome size. "Proteomic constraint" proposes that modulators of mutation rates such as DNA repair genes are subject to selection pressure proportional to the amount of information in a genome. Proteoforms. There are different factors that can add variability to proteins. SAPs (single amino acid polymorphisms) and non-synonymous single-nucleotide polymorphisms (nsSNPs) can lead to different "proteoforms" or "proteomorphs".
The gastrointestinal hormones (or gut hormones) constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas, and small intestine that control various functions of the digestive organs. Later studies showed that most of the gut peptides, such as secretin, cholecystokinin or substance P, were found to play a role of neurotransmitters and neuromodulators in the central and peripheral nervous systems. Enteroendocrine cells do not form glands but are spread throughout the digestive tract. They exert their autocrine and paracrine actions that integrate gastrointestinal function.
=== Drug use === In 2005, the federally funded Monitoring the Future annual survey reported about 85% of high school seniors found marijuana "easy to obtain", virtually unchanged since 1975, never dropping below 82.7% in three decades of national surveys. The DEA stated that the number of users of cannabis in the US declined between 2000 and 2005, even with many states passing new medical cannabis laws, making access easier, though usage rates remain higher than they were in the 1990s according to the National Survey on Drug Use and Health.
== Evolution of DNA == One of the challenges posed by the RNA world hypothesis is to discover the pathway by which an RNA-based system transitioned to one based on DNA. Geoffrey Diemer and Ken Stedman, at Portland State University in Oregon, may have found a solution. While conducting a survey of viruses in a hot acidic lake in Lassen Volcanic National Park, California, they uncovered evidence that a simple DNA virus had acquired a gene from a completely unrelated RNA-based virus. Virologist Luis P. Villarreal of the University of California Irvine also suggests that viruses capable of converting an RNA-based gene into DNA and then incorporating it into a more complex DNA-based genome might have been common in the virus world during the RNA to DNA transition some 4 billion years ago. This finding bolsters the argument for the transfer of information from the RNA world to the emerging DNA world before the emergence of the last universal common ancestor. From the research, the diversity of this virus world is still with us.
Sources: en.wikipedia.org
特沙莫瑞林是国际非专利名称,指一种经过 N 端修饰的生长激素释放激素类似物。它被归类为合成肽,序列与 GHRH(1-44) 密切相关。该名称不指代任何特定品牌或剂型。
监管批准集中于 HIV 感染相关的脂肪营养不良,目的是减少内脏脂肪。它未被批准用于普通肥胖或一般体重管理。不同国家的批准状态和标签范围可能不同。
长期心血管获益、死亡率影响以及停药后的持续性仍缺乏确证。部分研究提示 IGF-1 和血糖参数可能变化,但个体差异较大。这些开放问题需要更长期、更大规模的试验来回答。
It mimics a natural hypothalamic signal that tells the pituitary to release growth hormone. The result is a rise in circulating growth hormone and, indirectly, in insulin-like growth factor 1. Over weeks of treatment this shift is associated with a selective decrease in fat stored inside the abdomen.