Everything below concerns Freeze-thaw. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-14. Numbers and descriptions here follow the published literature rather than marketing material.
Activation of the GLP-1 receptor couples to Gs signalling and raises intracellular cyclic AMP in pancreatic beta cells. The resulting insulin release depends on prevailing glucose concentrations, so the effect is greater when glucose is elevated. Receptor engagement also suppresses glucagon secretion and slows gastric emptying, which flattens post-meal glucose excursions. In the central nervous system, signalling in hypothalamic and brainstem regions is associated with reduced appetite and lower energy intake. Studies continue to examine effects on cardiac, renal and hepatic endpoints; whether those benefits are independent of weight change remains an open question.
Clinical development of this compound followed earlier short-acting GLP-1 analogues that required frequent injection. Once-weekly subcutaneous formulations entered use after 2017, and an oral formulation using a permeation enhancer later became available. The oral version pairs the peptide with sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, a carrier that improves uptake across the gastric epithelium. Interest has expanded from glycaemic control into weight management and metabolic liver disease. Regulatory status and approved indications differ between countries, and the product remains subject to ongoing safety monitoring.
Semaglutide is a synthetic peptide that acts as an agonist at the glucagon-like peptide-1 receptor. It is a structural analogue of human GLP-1(7-37), modified to resist enzymatic degradation by dipeptidyl peptidase-4. The peptide backbone contains alpha-aminoisobutyric acid at position 8, a substitution that stabilises the helix and slows cleavage. A fatty diacid side chain attached through a linker at lysine 34 promotes binding to serum albumin, which extends the circulating half-life. These two modifications together allow less frequent administration than native GLP-1 requires.
Reported molecular weight is approximately 4113.6 daltons for the free base, and the peptide is supplied as a lyophilized powder or in buffered liquid form depending on the intended use. It is freely soluble in water when formulated with appropriate excipients, though the unconjugated peptide shows limited stability at neutral pH over long periods. Analytical characterization typically relies on reversed-phase high-performance liquid chromatography and mass spectrometry. Purity specifications for research-grade material commonly exceed ninety-five percent by area. Isotopic and impurity profiles differ between suppliers.
Two principal therapeutic variants exist under separate regulatory filings, one indicated for glycemic control in type 2 diabetes and one for chronic weight management. Both use the same active molecule; differences lie in formulation strength, titration schedule, and labeling. Regulatory agencies in the United States and European Union approved injectable forms in 2017 and 2018 respectively. An oral tablet formulation received approval later, using a carrier molecule to enhance absorption across the gastric epithelium. Labeling differs by jurisdiction and by indication.
The distinction between established facts and open questions matters here. That the peptide binds the GLP-1 receptor and stimulates insulin release in a glucose-dependent manner is well documented. How individual variability in receptor density, gastric emptying rate, and gut microbiome composition shapes response remains an active research area. Long-term outcomes beyond five years of continuous use are not yet fully characterized in published trials, and several extension studies are ongoing.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C187H291N45O59 | Parent peptide; salt forms also reported |
| Molecular mass | about 4113.6 Da | Average mass of the free peptide |
| Peptide length | 31 amino acids | Backbone related to GLP-1(7-37) |
| Key substitution | Aib at position 8 | Blocks DPP-4 cleavage |
| Albumin binding | Via C-18 diacid side chain | Prolongs circulation time |
The semaglutide sequence is a 31-residue analogue of human GLP-1, altered at three positions relative to the parent hormone. Aminoisobutyric acid replaces alanine at position 8, arginine replaces lysine at position 34, and a lipophilic diacid is attached to lysine 26 through a short linker. These features are reported consistently in the structural literature. The position 8 substitution blocks recognition by dipeptidyl peptidase-4, while the attached chain drives strong, reversible association with a carrier protein in blood.
Receptor activation raises intracellular cyclic AMP through Gs coupling, which promotes glucose-dependent insulin release and suppresses glucagon secretion when blood glucose is elevated. Effects outside the pancreas include slower gastric emptying and altered appetite signalling in the hypothalamus and hindbrain. The relative contribution of each tissue to overall metabolic outcomes remains an area of active investigation. Central mechanisms in particular are inferred mainly from animal models and indirect human measures rather than direct observation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 or 280 nanometres is widely used to assess purity and to resolve related impurities. Liquid chromatography coupled to mass spectrometry confirms identity through the protonated molecular ion and fragment ions formed in tandem experiments. Capillary electrophoresis and peptide mapping after enzymatic digestion supply complementary information on charge variants and modification sites. Circular dichroism and nuclear magnetic resonance can report on secondary structure in solution. Absolute quantification usually depends on an external standard, and reported purity depends on the detection wavelength and integration parameters chosen.
Lyophilised material appears as a white to off-white cake or powder that is hygroscopic, and containers are usually equilibrated to room temperature before opening to limit condensation. Dissolution is performed in water, phosphate-buffered saline, or a mildly alkaline buffer, since solubility rises above neutral pH. Gentle inversion or low-speed mixing is preferred, because vigorous vortexing can promote surface denaturation and aggregation. Complete dissolution may require several minutes, and brief sonication is sometimes applied. Passing the solution through a 0.22 micrometre membrane removes particulates but does not by itself sterilise the liquid.
Storage at minus 20 degrees Celsius or lower in a desiccated container preserves the peptide for extended periods, while working solutions are commonly held at two to eight degrees Celsius for short intervals. Light exposure and repeated freeze-thaw cycles accelerate degradation, so dividing material into single-use aliquots is generally recommended. Adsorption to glass and plastic surfaces can lower the measured concentration of dilute solutions, particularly below one milligram per millilitre. The degradation routes most often reported for GLP-1 analogues are deamidation, methionine oxidation, and backbone hydrolysis. Relative rates under specific conditions are frequently described only for individual formulations.
Receptor binding triggers G protein signaling that raises intracellular cyclic AMP in pancreatic beta cells. Insulin release follows in a glucose-dependent manner, so secretion increases when blood glucose is elevated and diminishes when it is not. The same signaling suppresses glucagon release from alpha cells and slows gastric emptying, which blunts the post-meal glucose rise. In the brain, receptor activation in regions such as the arcuate nucleus is associated with reduced appetite and lower energy intake. How much each of these effects contributes to overall weight change is not fully settled.
Two structural features account for the prolonged half-life of semaglutide. A modified amino acid at position 8 resists cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GLP-1. A fatty diacid side chain binds serum albumin, which limits renal clearance and protects the peptide from enzymatic breakdown. These modifications yield a plasma half-life of approximately one week in humans, allowing once-weekly administration. The relationship between plasma concentration and clinical effect varies between individuals, and sources of that variability are still being characterized.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1 (GLP-1), a hormone released from intestinal L-cells after food intake. The compound belongs to the incretin mimetic class and acts at GLP-1 receptors distributed across pancreatic, gastrointestinal, cardiovascular, and central nervous system tissues. Compared with native GLP-1, the molecule carries structural changes that extend its activity from minutes to roughly one week. It is studied for glycemic control in type 2 diabetes and for weight management, and its effects on cardiovascular and other outcomes remain active research areas.
Former Australian football player Adam Cooney stated, "I would say that 90–95 per cent of the population would put their hand up and do [what James Magnussen did], they're not going to get anywhere near a world record obviously, but it is pretty enticing." Swimmer Kyle Chalmers, who declined joining TEG since he wants to compete in the 2028 Olympics, voiced support for retired swimmers like Magnussen if they wanted to join TEG. He said "I think that swimmers have been underpaid for a very long time at the big competitions."
The size of aquasomes ranges from 60 to 300 nanometers, hence their characterization as a nanoparticle drug carrier. The nanoscale of aquasomes gives them a high surface area to volume ratio. The smaller the core, the higher the surface area to volume ratio, which increases the drug loading capacity of the aquasome. Aquasomes possess water-like properties due to the presence of the carbohydrate coating, enabling them to protect and preserve fragile biological molecules. The size of aquasome particles increases as a function of the ratio between the concentration of the core to the coat due to the availability of free surface core particles for the coating material. The self-assembly process of aquasomes into their tri-layer structure is achieved by non-covalent and ionic bonds, along with physicochemical properties of their components. Calcium phosphate nanoparticles are formed before the carbohydrate coat is adsorbed onto the surface of the core through electrostatic interactions. Layers are then added to the structure to achieve desired size, while crosslinked polymers aid in further stabilization. The sonication process during the reaction of disodium hydrogen phosphate and calcium chloride to prepare calcium phosphate impacts the self-assembly process of aquasomes by increasing surface free energy of the core prepared. This assembly process allows the design of aquasomes for specific drug delivery applications. The structure of aquasomes can contribute to controlled drug release, drug stability, and intracellular targeting of the drug.
In 2017, research using a numerical model suggested that a RNA world may have emerged in warm ponds on the early Earth, and that meteorites were a plausible and probable source of the RNA building blocks (ribose and nucleic acids) to these environments. On August 29, 2012, astronomers at Copenhagen University reported the detection of a specific sugar molecule, glycolaldehyde, in a distant star system. The molecule was found around the protostellar binary IRAS 16293-2422, which is located 400 light years from Earth. Because glycolaldehyde is needed to form RNA, this finding suggests that complex organic molecules may form in stellar systems prior to the formation of planets, eventually arriving on young planets early in their formation. Nitriles, key molecular precursors of the RNA World scenario, are among the most abundant chemical families in the universe and have been found in molecular clouds in the center of the Milky Way, protostars of different masses, meteorites and comets, and also in the atmosphere of Titan, the largest moon of Saturn. A study in 2001 shows that nicotinic acid and its precursor, quinolinic acid can be "produced in yields as high as 7% in a six-step nonenzymatic sequence from aspartic acid and dihydroxyacetone phosphate (DHAP). The biosynthesis of ribose phosphate could have produced DHAP and other three carbon compounds. Aspartic acid could have been available from prebiotic synthesis or from the ribozyme synthesis of pyrimidines." This supports that NAD could have originated in the RNA world.
In a large observational study in Sweden, methadone was associated with a particularly high incidence of TdP, especially in younger patients. The incidence of TdP was 41.9 cases per 100,000 users of methadone in the 18-64 year old age group. In this study of TdP, methadone was the highest-risk drug in the 18-64 year-old group, with the sole exception of the antiarrhythmic drug amiodarone, which was associated with 66.5 cases of TdP per 100,000 amiodarone users. The high incidence of TdP in amiodarone-treated patients may indicate correlation and not causation because amiodarone is often prescribed to patients with preexisting heart conditions that independently increase the risk of TdP. Methadone likely causes cardiac arrhythmias (such as TdP) via two mechanisms. Like many other cardiotoxic drugs, methadone blocks the hERG K+ channel. The two enantiomers of methadone inhibit hERG channels with different potency. Dextromethadone, which is less potent as an opioid, is more potent at blocking the hERG channel with an IC50 of ~12 μM. Levomethadone has a lower affinity, with an IC50 of ~29 μM at the hERG channel. Methadone is also known to block the Nav1.5 voltage-gated Na+ channel (SCN5A) with an IC50 of ~10 μM, which is similar to the local anesthetic bupivacaine. Both enantiomers of methadone block the Nav1.5 channel with similar affinities. Bupivacaine is especially cardiotoxic among local anesthetics, and it is believed to act via this same sodium channel.
"I poured the wine into the chalice our church had given me. In the one-sixth gravity of the moon, the wine curled slowly and gracefully up the side of the cup. It was interesting to think that the very first liquid ever poured on the moon, and the first food eaten there, were communion elements." —Buzz Aldrin Aldrin received the Eucharist in the same hour that his local church did on that Sunday Sabbath and he later stated that "I sensed especially strongly my unity with our church back home, and with the Church everywhere".
Sources: en.wikipedia.org
The report argued that the UK's top-down strategy is driving vast increases in mineral demands with devastating impacts for mining-affected communities, and called for policies geared towards minimising the UK's overall mineral demands and tackling the impunity of British-listed mining corporations. Similarly, the Centre for International Governance Innovation (CIGI) has warned that the infrastructure of AI exposes a host of hidden environmental security issues, requiring international cooperation that accounts for sustainability and labour standards.
== Treatment == Currently, there is no cure for Urbach–Wiethe disease, although there are some ways to individually treat many of its symptoms. There has been some success with oral dimethyl sulfoxide (DMSO) and intralesional heparin, but this is not true in all cases. D-penicillamine has also shown promise, but has yet to have been used extensively. There are also some reports of patients being treated with etretinate, a drug typically prescribed to treat psoriasis. In some cases, calcifications in the brain can lead to abnormal electrical activity among neurons. Some patients are given anti-seizure medication to help deal with these abnormalities. Tracheostomy is often used to relieve upper respiratory tract infections. Carbon dioxide laser surgery of thickened vocal cords and beaded eyelid papules have improved these symptoms for patients. The discovery of the mutations of the ECM1 gene has opened the possibility of gene therapy or a recombinant EMC1 protein for Urbach–Wiethe disease treatment, but neither of these two options are currently available.
The following table is based on the ISSCAAP classification (International Standard Statistical Classification of Aquatic Animals and Plants) used by the FAO to collect and compile fishery statistics. The production figures have been extracted from the FAO FishStat database, and include both capture from wild fisheries and aquaculture production.
=== Non-invasive imaging === A variety of Sendai virus constructs carrying reporter genes were developed for non-invasive imaging of the virus infection in animals. They allow to study dynamics of SeV spread and clearance. Some of these constructs were designed to deliver luciferase genes, some to deliver green fluorescent protein (GFP), others to deliver red fluorescent protein (RFP).
Laboratory information management systems (LIMS): Implementing and managing computer systems specifically designed for pathology departments. These systems help in tracking and managing patient specimens, results, and other pathology data. Digital pathology: Involves the use of digital technology to create, manage, and analyze pathology images. This includes side scanning and automated image analysis. Telepathology: Using technology to enable remote pathology consultation and collaboration. Quality assurance and reporting: Implementing informatics solutions to ensure the quality and accuracy of pathology processes.
Sources: en.wikipedia.org
To avoid this, freshly prepared samples as well as complementary analysis methods are used for confident nuclear materials characterization. The decay of nuclear samples makes rapid analysis methods highly desirable.
== History == Romergoline was first described in the scientific literature in 1991. It was under development by Pharmacia Corporation, but its development was discontinued by the early 2000s and the drug was never marketed.
=== Antibiotic === Honey has long been used as a topical antibiotic by practitioners of traditional and herbal medicine. Honey's antibacterial effects were first demonstrated by the Dutch scientist Bernardus Adrianus van Ketel in 1892. Since then, numerous studies have shown that honey has broad-spectrum antibacterial activity against gram-positive and gram-negative bacteria, although potency varies widely between different honeys. Due to the proliferation of antibiotic-resistant bacteria in the last few decades, there has been renewed interest in researching the antibacterial properties of honey. Components of honey under preliminary research for potential antibiotic use include methylglyoxal, hydrogen peroxide, and royalisin (also called defensin-1).
The leaves are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never anastomosing to form a network. Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as dichotomous venation. The leaves are usually 5–10 cm (2–4 in), but sometimes up to 15 cm (6 in) long. The old common name, maidenhair tree, derives from the leaves resembling pinnae of the maidenhair fern, Adiantum capillus-veneris. Ginkgos are prized for their autumn foliage, which is a deep saffron yellow. The species is heterophyllous (two types of leaves); those on the long shoots are thicker, have higher rates of photosynthesis, higher vein density and leaf hydraulic conductance, while those on the short shoots are better at handling drought. Leaves of long shoots are also usually notched or lobed, but only from the outer surface, between the veins. They are borne both on the more rapidly growing branch tips, where they are alternate and spaced out, and also on the short, stubby spur shoots, where they are clustered at the tips. Leaves are green both on the top and bottom and have stomata on both sides. During autumn, the leaves turn a bright yellow and then fall, sometimes within a short space of time (one to fifteen days). Leaves of the cultivar 'Tubifolia' have funnel-shaped leaves.
The weight loss in anorexia nervosa also causes atrophy of cardiac muscle. This leads to decreased ability to pump blood, a reduction in the ability to sustain exercise, a diminished ability to increase blood pressure in response to exercise, and a subjective feeling of fatigue. Some individuals may also have a decrease in cardiac contractility. Cardiac complications can be life-threatening, but the heart muscle generally improves with weight gain, and the heart normalizes in size over weeks to months, with recovery. Atrophy of the heart muscle is a marker of the severity of the disease, and while it is reversible with treatment and refeeding, it is possible that it may cause permanent, microscopic changes to the heart muscle that increase the risk of sudden cardiac death. Individuals with anorexia nervosa may experience chest pain or palpitations; these can be a result of mitral valve prolapse. Mitral valve prolapse occurs because the size of the heart muscle decreases while the tissue of the mitral valve remains the same size. Studies have shown rates of mitral valve prolapse of around 20 percent in those with anorexia nervosa, while the rate in the general population is estimated at 2–4 percent. It has been suggested that there is an association between mitral valve prolapse and sudden cardiac death, but it has not been proven to be causative, either in patients with anorexia nervosa or in the general population.
Sources: en.wikipedia.org
It belongs to the incretin mimetic class and acts as a long-acting glucagon-like peptide-1 receptor agonist. The class includes several peptides with different half-lives and routes of administration.
The side chain enables reversible binding to albumin in the bloodstream, which protects the peptide from rapid renal clearance. This extends the interval between administrations compared with unmodified GLP-1.
No. It shares much of the native sequence but carries substitutions and an added side chain. These changes increase stability against enzymatic breakdown.
It is a modified version of the natural hormone, with three amino acid changes and a fatty acid side chain added. These edits extend its half-life from minutes to about one week. The core receptor activity is retained.