If you have been reading about Related impurities and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
The peer-reviewed record is dominated by small early-phase studies, case reports and pharmacovigilance summaries rather than large randomised trials. Papers typically examine tanning response, receptor selectivity or patterns of reported adverse events. Many note that participants obtained the peptide outside a clinical setting, which limits verification of composition and administered amount. Reported events vary widely, and causality is frequently unclear because the identity and purity of self-sourced material are unknown. Open questions include whether repeated melanocortin receptor stimulation produces cumulative effects, and how often label claims match actual content.
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
Identity testing for a cyclic peptide of this size usually relies on reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The mass spectrum confirms molecular weight, while the chromatographic trace indicates the proportion of related impurities. Tandem mass spectrometry can provide sequence-level information when fragmentation data are compared against a reference standard. Nuclear magnetic resonance is sometimes used to confirm the lactam bridge, although it requires more material and greater operator expertise than routine chromatographic methods.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
Melanotan II is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide involved in pigment production. The analogue carries a lactam bridge that constrains the ring and slows enzymatic breakdown relative to the native hormone. In research literature it appears under several abbreviations, and naming conventions are not fully standardized. Published descriptions usually place it within the broader melanocortin agonist family.
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
== Career == Bigbie attended Ball State University. In 1998, he played collegiate summer baseball with the Wareham Gatemen of the Cape Cod Baseball League. Bigbie was drafted by the Baltimore Orioles in the 1st round (21st pick overall) of the 1999 Major League Baseball amateur draft and played over four years (2001–2005) for the Orioles before being traded during the 2005 season to the Colorado Rockies. Bigbie played the remainder of 2005 season for the Rockies. On December 8, 2005, the Rockies traded him and Aaron Miles to the St. Louis Cardinals for pitcher Ray King. On February 2, 2007, he signed a minor league deal with the Los Angeles Dodgers. Bigbie exercised a free agent option in his contract on June 1, 2007, and on June 11 signed a minor league contract with the Braves. During his six-year career, he posted a .268 batting average, hitting 31 home runs and amassing 322 hits in 375 games. Bigbie is an average fielder, but has an above-average arm. He batted .240 in 2006 with the Cardinals, also posting only 1 RBI, in 17 games. In December 2007, it was announced that he had agreed to a deal to play for the Yokohama Bay Stars of the Nippon Professional Baseball (NPB). Bigbie made a comeback for the 2010 season, playing for the Edmonton Capitals of the Golden Baseball League. Bigbie was named the DH for Baseball America's 2010 All-Independent Leagues Team.
=== Family === Han Chinese families throughout China have had certain traditionally prescribed roles, such as the family head (家長, jiāzhǎng), who represents the family to the outside world and the family manager (當家, dāngjiā), who is in charge of the revenues. Because farmland was commonly bought, sold or mortgaged, families were run like enterprises, with set rules for the allocation (分家, fēnjiā) of pooled earnings and assets. Han Chinese houses differ from place to place. In Beijing, the whole family traditionally lived together in a large rectangle-shaped house called a siheyuan. Such houses had four rooms at the front –the guest room, kitchen, lavatory, and servants' quarters. Across large double doors was a wing for the elderly in the family. This wing consisted of three rooms: a central room where the four tablets—heaven, earth, ancestor and teacher—were worshipped and two rooms attached to the left and right, which were bedrooms for the grandparents. The east wing of the house was inhabited by the eldest son and his family, while the west wing sheltered the second son and his family. Each wing had a veranda; some had a "sunroom" made with surrounding fabric and supported by a wooden or bamboo frame. Every wing was also built around a central courtyard that was used for study, exercise or nature viewing.
A 2004 essay on the relation between car colour and safety stated that no previous studies had been scientifically conclusive. Since then, a Swedish study found that pink cars are involved in the fewest and black cars are involved in the most crashes (Land transport NZ 2005). In Auckland New Zealand, a study found that there was a significantly lower rate of serious injury in silver cars, with higher rates in brown, black, and green cars. The Vehicle Colour Study, conducted by Monash University Accident Research Centre (MUARC) and published in 2007, analysed 855,258 crashes that occurring between 1987 and 2004 in the Australian states of Victoria and Western Australia that resulted in injury or in a vehicle being towed away. The study analysed risk by light condition. It found that in daylight, black cars were 12% more likely than white to be involved in a collision, followed by grey cars at 11%, silver cars at 10%, and red and blue cars at 7%, with no other colours found to be significantly more or less risky than white. At dawn or dusk, the risk ratio for black cars jumped to 47% more likely than white, and that for silver cars to 15%. In the hours of darkness, only red and silver cars were found to be significantly more risky than white, by 10% and 8% respectively.
The 6d orbitals are destabilized by relativistic effects and spin–orbit interactions near the end of the fourth transition metal series, thus making the high oxidation state roentgenium(V) more stable than its lighter homologue gold(V) (known only in gold pentafluoride, Au2F10) as the 6d electrons participate in bonding to a greater extent. The spin-orbit interactions stabilize molecular roentgenium compounds with more bonding 6d electrons; for example, RgF−6 is expected to be more stable than RgF−4, which is expected to be more stable than RgF−2. The stability of RgF−6 is homologous to that of AuF−6; the silver analogue AgF−6 is unknown and is expected to be only marginally stable to decomposition to AgF−4 and F2. Moreover, Rg2F10 is expected to be stable to decomposition, exactly analogous to the Au2F10, whereas Ag2F10 should be unstable to decomposition to Ag2F6 and F2. Gold heptafluoride, AuF7, is known as a gold(V) difluorine complex AuF5·F2, which is lower in energy than a true gold(VII) heptafluoride would be; RgF7 is instead calculated to be more stable as a true roentgenium(VII) heptafluoride, although it would be somewhat unstable, its decomposition to Rg2F10 and F2 releasing a small amount of energy at room temperature. Roentgenium(I) is expected to be difficult to obtain. Gold readily forms the cyanide complex Au(CN)−2, which is used in its extraction from ore through the process of gold cyanidation; roentgenium is expected to follow suit and form Rg(CN)−2.
Sources: en.wikipedia.org
Aging in dogs varies widely depending on the breed; certain breeds, such as giant dog breeds and English Bulldogs, have much shorter lifespans than average. Most dogs reach adolescence by one year old; smaller and medium-sized breeds begin to age more slowly in adulthood. Old elephants near death do not leave their herd to go to an "elephants' graveyard" to die. The hippopotamus does not produce pink milk, nor does it sweat blood. The skin secretions of the hippopotamus are red due to the presence of hipposudoric acid, a red pigment which acts as a natural sunscreen, and is neither sweat nor blood. It does not affect the color of their milk, which is white or beige. Lemmings do not engage in mass suicide by diving off cliffs. The idea was popularized by the 1958 Disney documentary film White Wilderness, in which the lemmings were repeatedly shoved off a cliff by the filmmakers to create the illusion of a mass suicide. The misconception itself is much older, dating back to at least the late 19th century, though its exact origins are uncertain. Mice do not have a special appetite for cheese, and will eat it only for lack of better options; they actually favor sweet sugary foods. The myth may have come from the fact that before the advent of refrigeration, cheese was usually stored outside and was therefore a food easy for mice to reach. Porcupines do not shoot their quills. They can detach, and porcupines will deliberately back into attackers to impale them, but their quills do not project. Rabbits are not especially partial to carrots.
Baeckeoffe, a potato stew from Alsace Beef bourguignon, a French dish of beef stewed in red burgundy wine Bigos, a traditional stew in Polish cuisine Birria, a traditional stew from Mexico Bo kho (Vietnamese: bò kho), a beef stew in rich seasonings, served with bread, noodle or plain rice from Vietnam Bollito misto, consisting of beef, veal, and pork simmered in an aromatic vegetable broth from Italy Booyah, an American meat stew Bosnian pot, a stew with beef or lamb which is a national dish in Bosnia and Herzegovina Bouillabaisse, a fish stew from Provence Brongkos, a spicy Javanese meat with beans stew from Indonesia, made of Pangium edule, coconut milk, and various spices Brunswick stew, from Virginia and the Carolinas Burgoo, a Kentuckian stew Brudet, fish stew from Dalmatia regions, known in Greece as bourdeto Caldeirada, a fish stew from Portugal Carbonade flamande (stoofvlees), a traditional Belgian beef and onion stew made with Belgian beer Cawl, a Welsh stew Chakapuli, a Georgian stew made with lamb chops, coriander and tarragon leaves, and white wine Chanakhi, a Georgian lamb stew with tomatoes, aubergines, potatoes, greens, and garlic Charquicán, a Chilean dish Chicken mull, whole chicken and seasonings Chicken paprikash, chicken stew with paprika Chili con carne, a meat and chili pepper stew originating in Texas Chilorio, a pork stew from Sinaloa, Mexico Cincinnati chili, developed by Macedonian immigrants from Greece immigrants in the Cincinnati area Cholent, a slow-cooked Jewish dish Chorba (also spelt "shorba"), a stew like soup dish found in various North African, Middle Eastern, Central Asian, South Asian, and European cuisines Cochinita pibil, an orange color pork stew from Yucatán Peninsula, Mexico Cocido, a traditional Spanish and Portuguese strew with many variants (madrileño, montañés, à portuguesa, etc.) Cotriade, a fish stew from Brittany Cream stew, a yōshoku Japanese white stew Crow stew, a sour cream-based stew made with crow meat, popular in the United States during the Great Depression Daal, the Indian legume stew that has many varieties, a staple food throughout Asia Dalma, a traditional dish of Odisha, India; contains pulses with vegetables Daube, a French stew made with cubed beef braised in wine, vegetables, garlic, and herbs Dinuguan, pork blood stew from the Philippines Eintopf, ('one pot') the German word for a stew: many different regional specialty recipes for Eintopf are known in Germany. For example, the Kassel area has a type called Lumben un Fleeh in the local dialect (Standard German: Lumpen und Flöhe – 'rags and fleas'), which is quite similar to Irish stew. There are thicker German stews such as Hasenpfeffer or Labskaus; these would not usually be considered an Eintopf, though the technical difference is minor (longer cooking times and fewer vegetables) Estofadong baboy, pork stew from the Philippines Ewedu, vegetable stew from Nigeria Fabada asturiana, an Asturian bean and meat stew Feijoada, Brazilian or Portuguese bean stew Fårikål, traditional Norwegian stew with lamb or mutton and white cabbage Főzelék, a thick Hungarian vegetable dish Gaisburger Marsch, a German dish of stewed beef served with Spätzle and potatoes Gheimeh, an Iranian stew with cubed lamb and yellow split peas Ghormeh sabzi, an Iranian stew with green herbs, dried limes, beans, and sheep meat Goulash, a Hungarian meat stew with paprika Gumbo, a Louisiana creole dish Hachee, a Dutch type of stew with wine or vinegar Haleem, an Indian-Pakistani lentil and beef stew Hasenpfeffer, a sour, marinated rabbit stew from Germany Hayashi rice, a Japanese dish of beef, onions and mushrooms in red wine and demi-glace sauce, served with rice Irish stew, made with lamb or mutton, potato, onion, and parsley Ishtu, a curry in Kerala, India made from chicken or mutton, potato, and coconut milk Istrian stew or yota, or jota, a dish popular in Croatian and Slovenian Istra and NE Italy I-tal stew, a Rastafarian vegan dish of mostly Caribbean root vegetables and spices Jjigae, a diverse range of Korean stews Kaldereta, a goat meat stew from the Philippines Kalops, a traditional Swedish beef stew, with onions and carrots, served with potatoes and pickled beets Kare-kare, stewed beef or oxtail and vegetables in peanut sauce from the Philippines Karelian hot pot, from the region of Karelia in eastern Finland Kharcho is a traditional Georgian soup containing beef, rice, cherry plum purée, and chopped walnuts Khash, a traditional Armenian/Azerbaijani dish of pig's or cow's feet Khoresht, a variety of Persian stews, often prepared with saffron Kokkinisto, Greek stew with red meat, in a tomato passata with shallots, cinnamon, and other spices Kuurdak, a type of stew from Central Asia Kuzhambu, (also called Pulusu or Saaru, depending on region) a range of stews from southern India based on tamarind broth and vegetables, meat or fish Lobscouse, a Norwegian stew with beef, potato, onion, and carrot Lancashire hotpot, an English stew Lecsó, a summertime favourite in Hungary, vegetable stew with bell pepper and tomato as main ingredients Linseneintopf ("lentil stew") Lobby, a stew from Staffordshire, England Locro, a stew (mainly in the Andes region) Machanka, a Belarus and Ukraine pork stew Matelote, a French fish stew made with freshwater fish, fish stock, and wine Mechado, a Philippine beef stew Moppelkotze Moqueca, a Brazilian stew with fish (or shrimp, crab, or other seafood) as its main ingredient Mućkalica, a Serbian stew Nihari, an Indian meat stew, usually made with goat, chicken, lamb and less commonly beef. It is made overnight and served for breakfast. Nikujaga, a Japanese beef and potato stew Oil down, national dish of Grenada, made of breadfruit, salted meat, chicken, dumplings, callaloo, coconut milk, and spices Olla podrida, a Spanish red bean stew Pašticada, a Croatian stew from the region of Dalmatia Peperonata, an Italian stew made with peppers Pepposo, a Tuscan beef stew Pescado blanco, a white fish stew from Pátzcuaro, Michoacán, Mexico Pichelsteiner a traditional German stew Pörkölt, a Hungarian meat stew resembling goulash, flavoured with paprika Potjiekos, a South African stew Pot-au-feu, a simple French beef stew Pozole, a Mexican stew or soup Puchero, a stew from Andalusia, Spain, also common in South America and the Philippines Ratatouille, a French vegetable stew Rendang, an Indonesian spicy beef stew Ragoût, a French stew Sāmbār, a lentil-based spiced vegetable stew, cooked with pigeon pea and tamarind broth in South Indian cuisine Sancocho, a stew from the Caribbean Scouse, a stew commonly eaten by sailors throughout Northern Europe, popular in seaports such as Liverpool Semur, a typical Indonesian stew with beef or chicken, potatoes, carrots, various spices, and kecap manis (sweet soy sauce) Stufato, an Italian stew Steckrübeneintopf (based on rutabaga) Slumgullion, a watery stew of meat and vegetables Tagine, a Moroccan stew, named after the conical pot in which it is traditionally cooked or served Tocană, a Romanian stew prepared with tomato, garlic, and sweet paprika Tharid, a traditional Arab stew of bread in broth Wat, an Ethiopian and Eritrean stew Waterzooi, a Belgian stew Yahni, a Greek (γιαχνί), Turkish, and Persian stew
The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite. The counter-current flow of the blood and dialysate maximizes the concentration gradient of solutes between the blood and dialysate, which helps to remove more urea and creatinine from the blood. The concentrations of solutes normally found in the urine (for example potassium, phosphorus and urea) are undesirably high in the blood, but low or absent in the dialysis solution, and constant replacement of the dialysate ensures that the concentration of undesired solutes is kept low on this side of the membrane. The dialysis solution has levels of minerals like potassium and calcium that are similar to their natural concentration in healthy blood. For another solute, bicarbonate, dialysis solution level is set at a slightly higher level than in normal blood, to encourage the diffusion of bicarbonate into the blood, to act as a pH buffer to neutralize the metabolic acidosis that is often present in these patients. The levels of the components of dialysate are typically prescribed by a nephrologist according to the needs of the individual patient. In peritoneal dialysis, wastes and water are removed from the blood inside the body using the peritoneum as a natural semipermeable membrane.
== Contraindications == The two contraindications to taking ezetimibe are a previous allergic reaction to it, including symptoms of rash, angioedema, anaphylaxis, and severe liver disease, especially when taken with a statin. Ezetimibe may have significant medication interactions with ciclosporin and with fibrates other than fenofibrate.
Mallory's trichrome stain also called Mallory's Triple Stain is a stain utilized in histology to aid in revealing different macromolecules that make up the cell. It uses the three stains: aniline blue, acid fuchsin, and orange G. As a result, this staining technique can reveal collagen, ordinary cytoplasm, and red blood cells. It is used in examining the collagen of connective tissue. For tissues that are not directly acidic or basic, it can be difficult to use only one stain to reveal the necessary structures of interest. A combination of the three different stains in precise amounts applied in the correct order reveals the details selectively. This is the result of more than just electrostatic interactions of stain with the tissue and the stain not being washed out after each step. Collectively the stains complement one another. The staining technique was first published in 1900 by Frank Burr Mallory, then a histologist at Harvard University Medical School. Many variants of the method exist to simplify or speed processing or to stain other materials. Mallory's and other polychrome stains developed in the early 20th century led to Papanicolaou stain and other popular polychrome staining methods. The primary application when the stain was introduced was differentiation of structures in connective tissue, and this remains its most common use. Some work however has indicated the stain can highlight differential RNA synthesis. This has been used in identifying ectopic endometrial tissue.
Sources: en.wikipedia.org
For example, phenanthrene has two Clar structures: one with just one aromatic sextet (the middle ring), and the other with two (the first and third rings). The latter case is therefore the more characteristic electronic nature of the two. Therefore, in this molecule the outer rings have greater aromatic character whereas the central ring is less aromatic and therefore more reactive. In contrast, in anthracene the resonance structures have one sextet each, which can be at any of the three rings, and the aromaticity spreads out more evenly across the whole molecule. This difference in number of sextets is reflected in the differing ultraviolet–visible spectra of these two isomers, as higher Clar pi-sextets are associated with larger HOMO–LUMO gaps; the highest-wavelength absorbance of phenanthrene is at 293 nm, while anthracene is at 374 nm. Three Clar structures with two sextets each are present in the four-ring chrysene structure: one having sextets in the first and third rings, one in the second and fourth rings, and one in the first and fourth rings. Superposition of these structures reveals that the aromaticity in the outer rings is greater (each has a sextet in two of the three Clar structures) compared to the inner rings (each has a sextet in only one of the three).
=== Prisoner exchange === Following the ceasefire on 18 July 2025, a prisoner exchange attempt on 20 July 2025 in the Umm al-Zaytoun town failed after a shelling from northern Suwayda, according to the Syrian Observatory for Human Rights.
=== Wound healing and cell guidance === One of the best-understood roles for bioelectric gradients is at the tissue-level endogenous electric fields utilized during wound healing. It is challenging to study wound-associated electric fields, because these fields are weak, less fluctuating, and do not have immediate biological responses when compared to nerve pulses and muscle contraction. The development of the vibrating and glass microelectrodes, demonstrated that wounds indeed produced and, importantly, sustained measurable electric currents and electric fields. These techniques allow further characterization of the wound electric fields/currents at cornea and skin wounds, which show active spatial and temporal features, suggesting active regulation of these electrical phenomena. For example, the wound electric currents are always the strongest at the wound edge, which gradually increased to reach a peak about 1 hour after injury. At wounds in diabetic animals, the wound electric fields are significantly compromised. Understanding the mechanisms of generation and regulation of the wound electric currents/fields is expected to reveal new approaches to manipulate the electrical aspect for better wound healing. How are the electric fields at a wound produced? Epithelia actively pump and differentially segregate ions. In the cornea epithelium, for example, Na+ and K+ are transported inwards from tear fluid to extracellular fluid, and Cl− is transported out of the extracellular fluid into the tear fluid.
== Structure == The structure of a polymeric material can be described at different length scales, from the sub-nm length scale up to the macroscopic one. There is in fact a hierarchy of structures, in which each stage provides the foundations for the next one. The starting point for the description of the structure of a polymer is the identity of its constituent monomers. Next, the microstructure essentially describes the arrangement of these monomers within the polymer at the scale of a single chain. The microstructure determines the possibility for the polymer to form phases with different arrangements, for example through crystallization, the glass transition or microphase separation. These features play a major role in determining the physical and chemical properties of a polymer.
Powdered alcohol is made by a process called micro-encapsulation. An auxiliary material for a capsule may be any readily water-soluble substance (e.g. carbohydrate such as dextrins (starch hydrolyzate), protein such as gelatin). For powdered alcohol, maltodextrin (a type of dextrin) was chosen. For the process to encapsulate, a method called spray drying was selected. In this process, a mixture of dextrin and the alcoholic drink is subjected to simultaneous spraying and heating. The spraying converts the liquid to small drops (up to several hundred μm (micrometers) in diameter), and the heat causes the hydrous dextrin to form a film. When the film dries, the drop becomes a microcapsule containing a dehydrated alcoholic drink and dextrin. Drying removes about 90% of the water and 10% of the ethanol from the initial liquid. An explanation for this preferential loss of water over volatile organics like ethanol is called "selective diffusion": a carbohydrate (in this case, maltodextrin) film forms during spray-drying on each droplet. The film allows smaller molecules like water to go through, but not larger ones like ethanol. As a result, more water is lost. The film is formed in about 0.1 second from the creation of the droplet by spraying. There is no time for the internal convection in each drop or capsule to occur. The end result of spray-drying is large amounts of microcapsules with the appearance of a powder. This is powdered alcohol. According to Sato's web page, powdered alcohol contains 30.5% ethyl alcohol by volume in the state of powder.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
Regulatory treatment varies by country. In the United States, the European Union and Australia it is an unapproved drug and its sale is restricted, while some other jurisdictions list it as prescription-only or controlled. The applicable rules depend on the country of import.