If you have been reading about MC1R 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.
Updated 2026-02-07. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
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.
| 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 |
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
Independent verification is central to quality control because the compound is not produced under pharmaceutical manufacturing standards. Third-party laboratories can measure purity, identity, residual solvents, and microbial contamination, though the scope of testing varies between services. Reported analyses of vendor samples have shown batch-to-batch variation in peptide content and the presence of truncated or oxidized species. How much of this variation reflects synthesis conditions versus storage and shipping is not well characterized. No harmonized reference standard exists for the material as sold.
Handling guidance for melanotan II follows general practice for small synthetic peptides rather than a product-specific monograph. Lyophilized powder is typically kept at minus twenty degrees Celsius or colder, protected from light and moisture, because warmth and humidity accelerate degradation. Once reconstituted, solutions are usually refrigerated and used within a short window, as hydrolysis and microbial growth both become concerns. Repeated freeze-thaw cycles are generally avoided. These conventions come from laboratory peptide chemistry and not from formal stability studies on this specific compound.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
=== Wild birds and fish === Thiamine deficiency has been identified as the cause of a paralytic disease affecting wild birds in the Baltic Sea area dating back to 1982. In this condition, there is difficulty in keeping the wings folded along the side of the body when resting, loss of the ability to fly and voice, with eventual paralysis of the wings and legs and death. It affects primarily 0.5–1 kg-sized birds such as the European herring gull (Larus argentatus), common starling (Sturnus vulgaris), and common eider (Somateria mollissima). Researchers noted, "Because the investigated species occupy a wide range of ecological niches and positions in the food web, we are open to the possibility that other animal classes may develop thiamine deficiency, as well."p. 12006 In the counties of Blekinge and Skåne, mass deaths of several bird species, especially the European herring gull, have been observed since the early 2000s. More recently, species of other classes seems to be affected. High mortality of salmon (Salmo salar) in the river Mörrumsån is reported, and mammals such as the Eurasian elk (Alces alces) have died in unusually high numbers. Lack of thiamine is the common denominator where analysis is done. In April 2012, the County Administrative Board of Blekinge found the situation so alarming that they asked the Swedish government to set up a closer investigation.
intermediates in biosynthesis, in post-translational formation of proteins, in a physiological role (e.g. components of bacterial cell walls, neurotransmitters and toxins), natural or man-made pharmacological compounds, present in meteorites or used in prebiotic experiments (such as the Miller–Urey experiment), might be important neurotransmitters, such as γ-aminobutyric acid, and can play a crucial role in cellular bioenergetics, such as creatine.
== Budget principles == The U.S. Constitution (Article I, section 9, clause 7) states that "No money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law; and a regular Statement and Account of Receipts and Expenditures of all public Money shall be published from time to time." Each year, the president of the United States submits a budget request to Congress for the following fiscal year as required by the Budget and Accounting Act of 1921. Current law (31 U.S.C. § 1105(a)) requires the president to submit a budget no earlier than the first Monday in January, and no later than the first Monday in February. Typically, presidents submit budgets on the first Monday in February. The budget submission has been delayed, however, in some new presidents' first year when the previous president belonged to a different party. The federal budget is calculated largely on a cash basis. That is, revenues and outlays are recognized when transactions are made. Therefore, the full long-term costs of programs such as Medicare, Social Security, and the federal portion of Medicaid are not reflected in the federal budget. By contrast, many businesses and some other national governments have adopted forms of accrual accounting, which recognizes obligations and revenues when they are incurred. The costs of some federal credit and loan programs, according to provisions of the Federal Credit Reform Act of 1990, are calculated on a net present value basis. Federal agencies cannot spend money unless funds are authorized and appropriated by law.
=== Influenza === Flublok Quadrivalent is a licensed recombinant subunit vaccine for active immunisation against influenza. It contains HA proteins of four strains of influenza virus purified and extracted using the Baculovirus-insect expression system. The four viral strains are standardised annually according to United States Public Health Services (USPHS) requirements. Flublok Quadrivalent has a comparable safety profile to traditional trivalent and quadrivalent vaccine equivalents. Flublok is also associated with less local reactions (RR = 0.94, 95% CI 0.90–0.98, three RCTs, FEM, I2 = 0%, low‐ certainty evidence) and higher risk of chills (RR = 1.33, 95% CI 1.03–1.72, three RCTs, FEM, I2 = 14%, low‐certainty evidence).
Sources: en.wikipedia.org
=== Hot freshwater lakes === Jack W. Szostak suggested that geothermal activity provides greater opportunities for the origination of life in open lakes where there is a buildup of minerals. In 2010, based on spectral analysis of sea and hot mineral water, Ignat Ignatov and Oleg Mosin demonstrated that life may have predominantly originated in hot mineral water. Hot mineral water that contains hydrogen carbonate and calcium ions has the most optimal range. This case is similar to the origin of life in hydrothermal vents, but with hydrogen carbonate and calcium ions in hot water. The main studies were conducted in Rupite, Bulgaria, where a novel thermophylic bacterium Anoxybacillus rupiences sp. Nov. and cyanobacteria were identified. At a pH of 9–11, the reactions can take place in seawater. According to Melvin Calvin, certain reactions of condensation-dehydration of amino acids and nucleotides in individual blocks of peptides and nucleic acids can take place in the primary hydrosphere with pH 9–11 at a later evolutionary stage. Some of these compounds like hydrocyanic acid (HCN) have been proven in the experiments of Miller. This is the environment in which the stromatolites have been created. David Ward described the formation of stromatolites in hot mineral water at the Yellowstone National Park. In 2011, Tadashi Sugawara created a protocell in hot water.
==== Collapse of the health system ==== The resurgence of the pandemic began in February 2021, after a month of relative stability in the spread of the disease. In the beginning of February, the municipal secretary of health, Mauro Sparta, had declared that "the worst has already passed", even against warnings by specialists who said that this was not true and that there was an increase in Covid cases in the state of Rio Grande do Sul. The municipality would maintain, for 45 days, softer measures to combat the spread of the virus compared to the previous administration. During the month of February, specialists and researchers had alerted e published their concerns on the risk of the municipal's health system collapsing. On 23 February, Porto Alegre was classified again in the black flag category. However, Melo preferred to use the mechanism of "co-management", which would permit the various regions of the state to follow the standards of the prior designation that they had been classified, in this case being the red flag category. The softening of measures led to the spread of COVID-19 and also led to the overcrowding of urgent care units (UPAs) and health outposts in the city by up to 400%, alongside record numbers of those hospitalized and a line of 113 people attempting to fill vacancies at these medical centers by the end of the month.
Hydrolyzed vegetable protein (HVP) products are foodstuffs obtained by the hydrolysis of protein, and have a meaty, savory taste similar to broth (bouillon). Regarding the production process, a distinction can be made between acid-hydrolyzed vegetable protein (aHVP), enzymatically produced HVP, and other seasonings, e.g., fermented soy sauce. Hydrolyzed vegetable protein products are particularly used to round off the taste of soups, sauces, meat products, snacks, and other dishes, as well as for the production of ready-to-cook soups and bouillons.
It is important to mention that ESR studies were also performed that show a coexistence of the liquid-order/liquid-disorder phase from 0 to 8 mole% and as well as 8–27 mol%. The model membrane containing DPPC, cholesterol, and exchanging lipids 1 and 2 show a drastic increase in the linear relationship between (K) versus the mol% of cholesterol. At approximately 8 mol% of cholesterol the start of the liquid-disordered phase begins. This same relationship is observed in the DSPC, cholesterol, and exchanging lipids 2 and 3 but the start of the liquid-disorder phase occurs at approximately 5.2 mole% with and without the presence of ethanol. Also, there is a higher equilibrium constant value in which the studies relate it to the stronger acyl chain interactions due to this region having longer carbon chains which results in a higher melting point as well. This study not only proves that in the presence of ethanol a reorganization or induced phase change takes place between the cholesterol-phospholipid interaction but that by using higher concentrations of sterol compounds like cholesterol it can hinder the effects of ethanol. The research also suggests that ethanol enhances the association between cholesterol-phospholipids within the liquid-ordered bilayers. The mechanism on how ethanol induces the liquid-disorder phase as well as enhances the cholesterol-phospholipid association is still not understood.
== ISO 3650 – ISO 3999 == ISO 3650:1998 Geometrical Product Specifications (GPS) – Length standards – Gauge blocks ISO 3651 Determination of resistance to intergranular corrosion of stainless steels ISO 3651-1:1998 Austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) ISO 3651-2:1998 Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in media containing sulfuric acid ISO 3651-3:2017 Determination of resistance to intergranular corrosion of stainless steels — Part 3: Corrosion test for low-Cr ferritic stainless steels ISO 3652:1975 Shipbuilding — Inland vessels — Rope reels [Withdrawn without replacement] ISO 3653:1978 Cinematography — Spindles for 8 mm Type S motion-picture projector reels/spools — Dimensions ISO 3654:1983 Cinematography — Motion-picture camera cartridge, 8-mm Type S, Model I — Cartridge-camera interface and take-up core drive — Dimensions and specifications [Withdrawn without replacement] ISO 3655:1986 Acceptance conditions for vertical turning and boring lathes with one or two columns and a single fixed or movable table — General introduction and testing of the accuracy ISO 3656:2011 Animal and vegetable fats and oils — Determination of ultraviolet absorbance expressed as specific UV extinction ISO 3657:2020 Animal and vegetable fats and oils — Determination of saponification value ISO 3658 Crude or liquid petroleum products — Determination of density and relative density — Graduated bicapillary pyknometer method [Draft merged into ISO 3838] ISO 3659:1977 Fruits and vegetables — Ripening after cold storage ISO 3660:1976 Fishing nets – Mounting and joining of netting – Terms and illustrations ISO 3661:1977 End-suction centrifugal pumps — Baseplate and installation dimensions ISO 3662:1976 Hydraulic fluid power — Pumps and motors — Geometric displacements ISO 3663:1976 Polyethylene (PE) pressure pipes and fittings, metric series — Dimensions of flanges ISO 3664:2009 Graphic technology and photography — Viewing conditions ISO 3665:2011 Photography — Intra-oral dental radiographic film and film packets — Manufacturer specifications ISO/TR 3666:1998 Viscosity of water ISO 3667 Aircraft — Dimensions of hermetically sealed contactors [Rejected draft] ISO 3668:2017 Paints and varnishes — Visual comparison of colour of paints ISO 3669:2020 Vacuum technology — Dimensions of knife-edge flanges ISO 3670:1979 Blanks for plug gauges and handles (taper lock and trilock) and ring gauges — Design and general dimensions [Withdrawn without replacement] ISO 3671:1976 Plastics — Aminoplastic moulding materials — Determination of volatile matter ISO 3672 Plastics — Unsaturated-polyester resins (UP-R) ISO 3672-1:2000 Part 1: Designation system ISO 3672-2:2000 Part 2: Preparation of test specimens and determination of properties ISO 3673 Plastics — Epoxy resins ISO 3673-1:1996 Part 1: Designation ISO 3673-2:2012 Part 2: Preparation of test specimens and determination of properties of crosslinked epoxy resins ISO 3674:1976 Shipbuilding — Inland vessels — Deck rail [Withdrawn without replacement] ISO 3675:1998 Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method ISO 3676:2012 Packaging – Complete, filled transport packages and unit loads – Unit load dimensions ISO 3677:2016 Filler metal for soldering and brazing — Designation ISO 3678:1976 Paints and varnishes — Print-free test [Withdrawn: replaced with ISO 9117-6] ISO 3679:2015 Determination of flash no-flash and flash point — Rapid equilibrium closed cup method ISO 3680:2004 Determination of flash/no flash — Rapid equilibrium closed cup method [Withdrawn: replaced with ISO 3679] ISO 3681:2018 Binders for paints and varnishes — Determination of saponification value — Titrimetric method ISO 3682:1996 Binders for paints and varnishes — Determination of acid value — Titrimetric method [Withdrawn: replaced with ISO 2114] ISO 3683:1978 Soft soldered joints — Determination of shear strength [Withdrawn: replaced with ISO 5187] ISO 3684:1990 Conveyor belts — Determination of minimum pulley diameters ISO 3685:1993 Tool-life testing with single-point turning tools ISO 3686: Test conditions for high accuracy turret and single spindle coordinate drilling and boring machines with table of fixed height with vertical spindle — Testing of the accuracy ISO 3686-1:2000 Part 1: Single column type machines ISO 3686-2:2000 Part 2: Portal type machines with moving table ISO 3687:1976 Paper and board — Determination of air resistance (Gurley) [Withdrawn without replacement] ISO 3688:1999 Pulps — Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISO brightness) ISO 3689:1983 Paper and board — Determination of bursting strength after immersion in water ISO 3690:2018 Welding and allied processes — Determination of hydrogen content in arc weld metal ISO 3691 Industrial trucks — Safety requirements and verification ISO 3691-1:2011 Part 1: Self-propelled industrial trucks, other than driverless trucks, variable-reach trucks and burden-carrier trucks ISO 3691-2:2016 Part 2: Self-propelled variable-reach trucks ISO 3691-3:2016 Part 3: Additional requirements for trucks with elevating operator position and trucks specifically designed to travel with elevated loads ISO 3691-4:2020 Part 4: Driverless industrial trucks and their systems ISO 3691-5:2014 Part 5: Pedestrian-propelled trucks ISO 3691-6:2021 Part 6: Burden and personnel carriers ISO/TS 3691-7:2011 Part 7: Regional requirements for countries within the European Community [Withdrawn without replacement] ISO 3692:1976 Information processing – Reels and cores for 25,4 mm (1 in) perforated paper tape for information interchange – Dimensions [Withdrawn without replacement] ISO 3693:1977 Nitric acid for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3694:1977 Ammonium sulphate for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3695:1977 Ammonium nitrate for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3696:1987 Water for analytical laboratory use — Specification and test methods ISO 3697:1976 Sodium hydroxide for industrial use — Determination of calcium and magnesium contents — Flame atomic absorption method [Withdrawn without replacement] ISO 3698:1976 Potassium hydroxide for industrial use — Determination of calcium and magnesium contents — Flame atomic absorption method [Withdrawn without replacement] ISO 3699:1976 Anhydrous hydrogen fluoride for industrial use — Determination of water content — Karl Fischer method ISO 3700:1980 Anhydrous hydrogen fluoride for industrial use — Determination of water content — Conductimetric method [Withdrawn without replacement] ISO 3701:1976 Anhydrous hydrogen fluoride for industrial use — Determination of hexafluorosilicic acid content — Reduced molybdosilicate photometric method [Withdrawn without replacement] ISO 3702:1976 Anhydrous hydrogen fluoride for industrial use — Determination of sulphur dioxide content — Iodometric method [Withdrawn without replacement] ISO 3703:1993 Acid-grade and ceramic-grade fluorspar — Determination of flotation agents [Withdrawn without replacement] ISO 3704:1976 Sulphur for industrial use — Determination of acidity — Titrimetric method ISO 3705:1976 Sulphur for industrial use — Determination of arsenic content — Silver diethyldithiocarbamate photometric method ISO 3706:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of total phosphorus (V) oxide content — Quinoline phosphomolybdate gravimetric method ISO 3707:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of calcium content — Flame atomic absorption method [Withdrawn without replacement] ISO 3708:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of chloride content — Potentiometric method [Withdrawn without replacement] ISO 3709:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of oxides of nitrogen content — 3,4- Xylenol spectrophotometric method [Withdrawn without replacement] ISO 3710:1990 Lead chrome green pigments — Specifications and methods of test [Withdrawn without replacement] ISO 3711:1990 Lead chromate pigments and lead chromate-molybdate pigments — Specifications and methods of test ISO 3713:1987 Ferroalloys – Sampling and preparation of samples – General rules ISO 3714:1980 Oil of pennyroyal [Withdrawn without replacement] ISO 3715 Ships and marine technology – Propulsion plants for ships ISO 3715-1:2002 Part 1: Vocabulary for geometry of propellers ISO 3715-2:2001 Part 2: Vocabulary for controllable-pitch propeller plants ISO 3716:2021 Hydrometry – Functional requirements and characteristics of suspended-sediment samplers ISO/TR 3717:1975 Textile glass — Mats and woven fabrics — Determination of wet-out time through resin [Withdrawn without replacement] ISO/TR 3718:1975 Textile glass — Determination of wet-through time through resin [Withdrawn without replacement] ISO 3719:1994 Mechanical vibration — Symbols for balancing machines and associated instrumentation [Withdrawn without replacement] ISO 3720:2011 Black tea — Definition and basic requirements ISO 3721:2023 Information technology — Computer graphics, image processing and environmental data representation — Information model for Mixed and Augmented Reality Contents - Core Objects and Attributes [original draft was Rigid cellular practice — classification and designation] ISO 3722:1976 Hydraulic fluid power — Fluid sample containers — Qualifying and controlling cleaning methods ISO 3723:2015 Hydraulic fluid power — Filter elements — Method for end load test ISO 3724:2007 Hydraulic fluid power — Filter elements — Determination of resistance to flow fatigue using particulate contaminant ISO 3725:2023 Ships and marine technology — Aquatic nuisance species — Methods for evaluating the performance of compliance monitoring devices for ballast water discharges [original draft was Statistics – Symbols, merged into ISO 3534] ISO 3726:1983 Instant coffee — Determination of loss in mass at 70 degrees C under reduced pressure ISO 3727 Butter — Determination of moisture, non-fat solids and fat contents ISO 3727-1:2001 Part 1: Determination of moisture content (Reference method) ISO 3727-2:2001 Part 2: Determination of non-fat solids content (Reference method) ISO 3727-3:2003 Part 3: Calculation of fat content ISO 3728:2004 Ice-cream and milk ice — Determination of total solids content (Reference method) ISO 3729:1976 Fibre building boards — Determination of surface stability [Withdrawn without replacement] ISO 3730:2012 Shipbuilding and marine structures — Mooring winches ISO 3731:2003 Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole connector type 24 S (supplementary) for vehicles with 24 V nominal supply voltage ISO 3732:2003 Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole connector type 12 S (supplementary) for vehicles with 12 V nominal supply voltage ISO 3733:1999 Petroleum products and bituminous materials — Determination of water — Distillation method ISO 3734:1997 Petroleum products — Determination of water and sediment in residual fuel oils — Centrifuge method ISO 3735:1999 Crude petroleum and fuel oils — Determination of sediment — Extraction method ISO 3736 Digital fitting — Service process [original draft was Standard atmospheres for conditioning and/or testing — Specifications was numbered ISO 554 to replace ISO/R 554] ISO/TD 3736-1:2022 Part 1: Ready-to-wear clothing online and off-line ISO/TD 3736-2:2022 Part 2: Customized clothing online and off-line ISO 3737:1976 Agricultural tractors and self-propelled machines — Test method for enclosure pressurization systems [Withdrawn: replaced with ISO 14269-(1-5)] ISO 3738 Hardmetals — Rockwell hardness test (scale A) ISO 3738-1:1982 Part 1: Test method ISO 3738-2:1988 Part 2: Preparation and calibration of standard test blocks ISO 3739 Industrial tyres and rims ISO 3739-1:2007 Part 1: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims ISO 3739-2:2021 Part 2: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims — Load ratings ISO 3739-3:2021 Part 3: Rims ISO 3740:2019 Acoustics – Determination of sound power levels of noise sources – Guidelines for the use of basic standards ISO 3741:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for reverberation test rooms ISO 3742:1988 Acoustics — Determination of sound power levels of noise sources — Precision methods for discrete-frequency and narrow-band sources in reverberation rooms [Withdrawn: replaced with ISO 3741] ISO 3743 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for small movable sources in reverberant fields ISO 3743-1:2010 Part 1: Comparison method for a hard-walled test room ISO 3743-2:2018 Part 2: Methods for special reverberation test rooms ISO 3744:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for an essentially free field over a reflecting plane ISO 3745:2012 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for anechoic rooms and hemi-anechoic rooms ISO 3746:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Survey method using an enveloping measurement surface over a reflecting plane ISO 3747:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering/survey methods for use in situ in a reverberant environment ISO 3748 Acoustics — Determination of sound power levels of noise sources — Engineering method for small, nearly omnidirectional sources under free-field conditions over a reflecting plane [Rejected draft] ISO 3749:2022 Glass syringes — Determination of extractable tungsten [Original draft with this number unknown] ISO 3750:2006 Zinc alloys — Determination of magnesium content — Flame atomic absorption spectrometric method ISO 3751:1976 Zinc ingots — Selection and preparation of samples for chemical analysis [Withdrawn: replaced with ISO 20081] ISO 3752:1976 Zinc alloy ingots — Selection and preparation of samples for chemical analysis [Withdrawn: replaced with ISO 20081] ISO 3753:1977 Vacuum technology — Graphical symbols [Withdrawn without replacement] ISO 3754:1976 Steel — Determination of effective depth of hardening after flame or induction hardening [Withdrawn: replaced with ISO 18203] ISO 3755:1991 Cast carbon steels for general engineering purposes [Withdrawn: replaced with ISO 14737] ISO 3756:1976 Oil of cubeb ISO 3757:2002 Oil of patchouli (Pogostemon cablin (Blanco) Benth.) ISO 3758:2012 Textiles — Care labelling code using symbols ISO 3759:2011 Textiles — Preparation, marking and measuring of fabric specimens and garments in tests for determination of dimensional change ISO 3760:2002 Oil of celery seed (Apium graveolens L.) ISO 3761:2005 Oil of rosewood, Brazilian type (Aniba rosaeodora Ducke or Aniba parviflora (Meisn.) Mez.) ISO 3762:1979 Paper — Preparation of a letterpress print for test purposes [Withdrawn without replacement] ISO 3763:1976 Wrought steels — Macroscopic methods for assessing the content of non-metallic inclusions ISO 3764:2016 Timekeeping instruments — Movements — Types, dimensions and nomenclature ISO 3765:1998 Timekeeping instruments — Wristwatches — Dimensions of bracelet-to-case fastening elements ISO 3766:2003 Construction drawings – Simplified representation of concrete reinforcement ISO 3767 Tractors, machinery for agriculture and forestry, powered lawn and garden equipment – Symbols for operator controls and other displays ISO 3767-1:2016 Part 1: Common symbols ISO 3767-2:2016 Part 2: Symbols for agricultural tractors and machinery ISO 3767-3:2016 Part 3: Symbols for powered lawn and garden equipment ISO 3767-4:2016 Part 4: Symbols for forestry machinery ISO 3767-5:2016 Part 5: Symbols for manual portable forestry machines ISO 3768:1976 Metallic coatings — Neutral salt spray test (NSS test) [Withdrawn: replaced with ISO 9227] ISO 3769:1976 Metallic coatings — Neutral salt spray test (NSS test) [Withdrawn: replaced with ISO 9227] ISO 3770:1976 Metallic coatings — Copper-accelerated acetic acid salt spray test (CASS test) [Withdrawn: replaced with ISO 9227] ISO 3771:2011 Petroleum products — Determination of base number — Perchloric acid potentiometric titration method ISO 3772:2000 Photography — Rolls of sensitized material for the pre-press industry — Dimensions and related requirements ISO 3773:1983 Cinematography — Tape splices for 8 mm Type S motion-picture film for projector use — Dimensions ISO 3774:1988 Cinematography — 35 mm motion-picture film perforated 8 mm Type S (1-3-5-7-0) and (1-0) — Cutting and perforating dimensions ISO 3775:1990 Cinematography — Printed 8 mm Type S image area on 16 mm motion-picture film perforated 8 mm Type S (1-3) — Position and dimensions [Withdrawn without replacement] ISO 3776 Tractors and machinery for agriculture — Seat belts ISO 3776-1:2006 Part 1: Anchorage location requirements ISO 3776-2:2013 Part 2: Anchorage strength requirements ISO 3776-3:2009 Part 3: Requirements for assemblies ISO 3777:1976 Radiographic inspection of resistance spot welds for aluminium and its alloys — Recommended practice [Withdrawn without replacement] ISO/TR 3778:1987 Agricultural tractors — Maximum actuating forces required to operate controls [Withdrawn: replaced with ISO 15077] ISO 3779:2009 Road vehicles — Vehicle identification number (VIN) — Content and structure ISO 3780:2009 Road vehicles — World manufacturer identifier (WMI) code ISO 3781:2011 Paper and board — Determination of tensile strength after immersion in water ISO 3782:1980 Paper and board — Determination of resistance to picking — Accelerating speed method using the IGT tester (Pendulum or spring model) [Withdrawn without replacement] ISO 3783:2006 Paper and board — Determination of resistance to picking — Accelerated speed method using the IGT-type tester (electric model) ISO 3784:1976 Road vehicles — Measurement of impact velocity in collision tests ISO 3785:2006 Metallic materials — Designation of test specimen axes in relation to product texture ISO 3786:1975 Shipbuilding — Inland navigation towing hooks — Scale of tractive efforts [Withdrawn without replacement] ISO 3787:1976 Wood — Test methods — Determination of ultimate stress in compression parallel to grain [Withdrawn: replaced with ISO 13061-167] ISO/IEC 3788:1990 Information processing – 9-track, 12,7 mm (0,5 in) wide magnetic tape for information interchange using phase encoding at 126 ftpmm (3 200 ftpi), 63 cpmm (1 600 cpi) ISO 3789 Tractors, machinery for agriculture and forestry, powered lawn and garden equipment — Location and method of operation of operator controls ISO 3789-1:1982 Part 1: Common controls [Withdrawn: replaced with ISO 15077] ISO 3789-2:1982 Part 2: Controls for agricultural tractors and machinery [Withdrawn: replaced with ISO 15077] ISO 3790:1976 Fishing nets — Determination of elongation of netting yarns ISO 3791:1976 Office machines and data processing equipment – Keyboard layouts for numeric applications ISO 3792:1976 Adding machines – Layout of function keyboard ISO 3793:1976 Essential oils — Estimation of primary and secondary free alcohols content by acetylation in pyridine [Withdrawn without replacement] ISO 3794:1976 Essential oils (containing tertiary alcohols) — Estimation of free alcohols content by determination of ester value after acetylation ISO 3795:1989 Road vehicles, and tractors and machinery for agriculture and forestry — Determination of burning behaviour of interior materials ISO 3796:1999 Ships and marine technology — Clear openings for external single-leaf doors ISO 3797:1976 Shipbuilding — Vertical steel ladders ISO 3798:1976 Tinplate and blackplate — Minimum packaging requirements [Withdrawn without replacement] ISO 3799:1976 Textile machinery and accessories — Hydraulic lubricating fittings for textile machinery [Withdrawn without replacement] ISO 3800:1993 Threaded fasteners — Axial load fatigue testing — Test methods and evaluation of results ISO 3801:1977 Textiles — Woven fabrics — Determination of mass per unit length and mass per unit area ISO 3802:1976 Information processing – General purpose reels with 8 mm (5/16 in) centre hole for magnetic tape for interchange instrumentation applications ISO 3803:1984 Road vehicles — Hydraulic pressure test connection for braking equipment ISO 3804:1977 Plywood — Determination of dimensions of test pieces [Withdrawn: replaced with ISO 9424] ISO 3805:1977 Plywood — Determination of density [Withdrawn: replaced with ISO 9427] ISO 3806:1977 Plywood — Determination of moisture content [Withdrawn: replaced with ISO 9425] ISO 3807:2013 Gas cylinders — Acetylene cylinders — Basic requirements and type testing ISO 3808:2002 Road vehicles — Unscreened high-voltage ignition cables — General specifications, test methods and requirements ISO 3809:2004 Oil of lime (cold pressed), Mexican type (Citrus aurantifolia (Christm.) Swingle), obtained by mechanical means ISO 3810:1987 Floor tiles of agglomerated cork — Methods of test ISO 3811:1979 Meat and meat products — Detection and enumeration of presumptive coliform bacteria and presumptive Escherichia coli — (Reference method) [Withdrawn: replaced with ISO 4831, ISO 4832, and ISO 7251] ISO 3812:1976 Essential oils of geranium and rose — Determination of ester value after hot formylation ISO 3813:2004 Resilient floor coverings — Cork floor tiles — Specification [Withdrawn without replacement] ISO/TS 3814:2014 Standard tests for measuring reaction-to-fire of products and materials — Their development and application ISO 3815 Zinc and zinc alloys ISO 3815-1:2005 Part 1: Analysis of solid samples by optical emission spectrometry ISO 3815-2:2005 Part 2: Analysis by inductively coupled plasma optical emission spectrometry ISO 3816:1976 Zinc ingots — Selection and preparation of samples for spectrographic analysis [Withdrawn: replaced with ISO 20081] ISO 3817:1976 Zinc alloy ingots — Selection and preparation of samples for spectrographic analysis [Withdrawn: replaced with ISO 20081] ISO/TR 3818:1977 Ropes and cordage — Rope assemblies used in slinging — Safe working loads [Withdrawn without replacement] ISO 3819:2015 Laboratory glassware – Beakers ISO 3820:1978 Cinematography — Sprockets for 8 mm Type S motion-picture film — Dimensions and design ISO 3821:2019 Gas welding equipment — Rubber hoses for welding, cutting and allied processes ISO 3822 Acoustics – Laboratory tests on noise emission from appliances and equipment used in water supply installations ISO 3822-1:1999 Part 1: Method of measurement ISO 3822-2:1995 Part 2: Mounting and operating conditions for draw-off taps and mixing valves ISO 3822-3:2018 Part 3: Mounting and operating conditions for in-line valves and appliances ISO 3822-4:1997 Part 4: Mounting and operating conditions for special appliances ISO 3823 Dental rotary instruments — Burs ISO 3823-1:1997 Part 1: Steel and carbide burs ISO 3823-2:2003 Part 2: Finishing burs ISO 3824:1984 Dental silicophosphate cement (hand-mixed) [Withdrawn: replaced with ISO 9917] ISO 3825:1977 Glass transfusion bottles for medical use — Chemical resistance [Withdrawn without replacement] ISO 3826 Plastics collapsible containers for human blood and blood components ISO 3826-1:2013 Part 1: Conventional containers ISO 3826-2:2008 Part 2: Graphical symbols for use on labels and instruction leaflets ISO 3826-3:2006 Part 3: Blood bag systems with integrated features ISO 3826-4:2015 Part 4: Aphaeresis blood bag systems with integrated features ISO 3827 Shipbuilding — Co-ordination of dimensions in ships' accommodation ISO 3827-1:1977 Part 1: Principles of dimensional co-ordination ISO 3827-2:1977 Part 2: Glossary of terms ISO 3827-3:1977 Part 3: Co-ordinating sizes for components and assemblies ISO 3827-4:1977 Part 4: Controlling dimensions ISO 3827-5:1979 Part 5: Co-ordinating sizes for key components ISO 3828:2008 Shipbuilding and marine structures – Deck machinery – Vocabulary and symbols ISO 3829 Petroleum products – Determination of density and relative density – Jaulmes pyknometer method [Rejected draft] ISO 3830:1993 Petroleum products — Determination of lead content of gasoline — Iodine monochloride method ISO 3831:1979 Timekeeping instruments — Classification and numbering system and nomenclature of components for watches and clocks [Withdrawn without replacement] ISO 3832:2002 Passenger cars — Luggage compartments — Method of measuring reference volume ISO 3833:1977 Road vehicles – Types – Terms and definitions ISO 3834 Quality requirements for fusion welding of metallic materials ISO 3834-1:2021 Part 1: Criteria for the selection of the appropriate level of quality requirements ISO 3834-2:2021 Part 2: Comprehensive quality requirements ISO 3834-3:2021 Part 3: Standard quality requirements ISO 3834-4:2021 Part 4: Elementary quality requirements ISO 3834-5:2021 Part 5: Documents with which it is necessary to conform to claim conformity to the quality requirements of ISO 3834-2, ISO 3834-3 or ISO 3834-4 ISO 3834-6:2024 Part 6: Guidelines on implementing the ISO 3834 series ISO 3835 Equipment for vine cultivation and wine making – Vocabulary ISO 3835-1:1976 (No part title) ISO 3835-2:1977 (No part title) [Withdrawn without replacement] ISO 3835-3:1980 (No part title) ISO 3835-4:1981 (No part title) ISO 3835-5:1982 (No part title) [Withdrawn without replacement] ISO/TR 3836:1978 Shoe sizes — System of width grading (for use in the Mondopoint system) [Withdrawn without replacement] ISO 3837:1993 Liquid petroleum products — Determination of hydrocarbon types — Fluorescent indicator adsorption method ISO 3838:2004 Crude petroleum and liquid or solid petroleum products — Determination of density or relative density — Capillary-stoppered pyknometer and graduated bicapillary pyknometer methods ISO 3839:1996 Petroleum products — Determination of bromine number of distillates and aliphatic olefins — Electrometric method ISO 3840:1976 Petroleum distillates — Determination of olefinic plus aromatic hydrocarbons content [Withdrawn without replacement] ISO 3841:1977 Petroleum waxes — Determination of melting point (cooling curve) [Withdrawn without replacement] ISO 3842:2006 Road vehicles — Fifth wheels — Interchangeability ISO 3843 Dentistry — Dental attachments — Measurement of placement and removal forces [Under development; original draft named ISO 2135 as it was a revision of ISO/R 2135] ISO 3844:1975 Shoe sizes — Method of marking [Withdrawn: replaced with ISO 9407] ISO 3845:2024 Oil and gas industries including lower carbon energy — Full ring ovalization test method for the evaluation of the cracking resistance of steel line pipe in sour service [original draft was Petroleum and natural gas industries — High-test steel line pipe] ISO 3846:2008 Hydrometry – Open channel flow measurement using rectangular broad-crested weirs ISO 3847:1977 Liquid flow measurement in open channels by weirs and flumes – End-depth method for estimation of flow in rectangular channels with a free overfall [Withdrawn: replaced with ISO 18481] ISO 3848:2016 Essential oil of citronella, Java type ISO 3849:2003 Oil of citronella, Sri Lankan type (Cymbopogon nardus (L.) W. Watson var. lenabatu Stapf.) ISO 3850:2004 Resilient floor coverings – Determination of apparent density of composition cork ISO 3851:1977 Capsulated dental silicate and silico-phosphate filling materials [Withdrawn: replaced with ISO 9917] ISO 3852:2007 Iron ores for blast furnace and direct reduction feedstocks — Determination of bulk density ISO 3853:1994 Road vehicles — Towing vehicle coupling device to tow caravans or light trailers — Mechanical strength test ISO 3854:1976 Road vehicles — Caravans and light trailers — Vacuum braking — Measurement of reaction time [Withdrawn without replacement] ISO 3855:1977 Milling cutters – Nomenclature ISO 3856 Paints and varnishes — Determination of "soluble" metal content ISO 3856-1:1984 Part 1: Determination of lead content — Flame atomic absorption spectrometric method and dithizone spectrophotometric method ISO 3856-2:1984 Part 2: Determination of antimony content — Flame atomic absorption spectrometric method and Rhodamine B spectrophotometric method ISO 3856-3:1984 Part 3: Determination of barium content — Flame atomic emission spectrometric method ISO 3856-4:1984 Part 4: Determination of cadmium content — Flame atomic absorption spectrometric method and polarographic method ISO 3856-5:1984 Part 5: Determination of hexavalent chromium content of the pigment portion of the liquid paint or the paint in powder form — Diphenylcarbazide spectrophotometric method ISO 3856-6:1984 Part 6: Determination of total chromium content of the liquid portion of the paint — Flame atomic absorption spectrometric method ISO 3856-7:1984 Part 7: Determination of mercury content of the pigment portion of the paint and of the liquid portion of water-dilutable paints — Flameless atomic absorption spectrometric method ISO 3857 Compressors, pneumatic tools and machines – Vocabulary ISO 3857-1:1977 Part 1: General ISO 3857-2:1977 Part 2: Compressors ISO 3857-3:1989 Part 3: Pneumatic tools and machines ISO 3857-4:2012 Part 4: Air treatment ISO 3858:2018 Rubber compounding ingredients — Carbon black — Determination of light transmittance of toluene extract ISO 3859:2000 Inverse dovetail cutters and dovetail cutters with cylindrical shanks ISO 3860:2011 Bore cutters with key drive — Form milling cutters with constant profile ISO 3861:2005 Rubber hoses and hose assemblies for sand and grit blasting — Specification ISO 3862:2020 Rubber hoses and hose assemblies — Rubber-covered spiral-wire-reinforced hydraulic types for oil-based or water-based fluids — Specification ISO 3863:1989 Cylindrical cork stoppers — Dimensional characteristics, sampling, packaging and marking [Withdrawn without replacement] ISO 3864 Graphical symbols – Safety colours and safety signs ISO 3865:2020 Rubber, vulcanized or thermoplastic — Methods of test for staining in contact with organic material ISO 3866:1977 Office machines and printing machines used for information processing – Widths of fabric printing ribbons on spools exceeding 19 mm ISO 3867:2017 Composition cork — Expansion joint fillers — Test methods ISO 3868:1976 Metallic and other non-organic coatings — Measurement of coating thicknesses — Fizeau multiple-beam interferometry method ISO 3869:2017 Agglomerated cork — Expansion joint fillers — Specifications, packaging and marking ISO 3870:1976 Conveyor belts (fabric carcass), with length between pulley centres up to 300 m, for loose bulk materials — Adjustment of take-up device [Withdrawn without replacement] ISO 3871:2000 Road vehicles — Labelling of containers for petroleum-based or non-petroleum-based brake fluid ISO 3872:1976 Graphic technology — Sheet-fed printing machines — Range of sizes [Withdrawn without replacement] ISO 3873:1977 Industrial safety helmets ISO 3874:2017 Series 1 freight containers — Handling and securing ISO 3875:2020 Machine tools — Test conditions for external cylindrical centreless grinding machines — Testing of the accuracy ISO 3876:1986 Shipbuilding — Inland vessels — Hand-holes [Withdrawn without replacement] ISO 3877 Tyres, valves and tubes – List of equivalent terms ISO 3877-1:1997 Part 1: Tyres ISO 3877-2:1997 Part 2: Tyre valves ISO 3877-3:1978 Part 3: Tubes ISO 3877-4:1984 Part 4: Solid tyres ISO 3878:1983 Hardmetals — Vickers hardness test [Withdrawn without replacement] ISO 3879:1977 Welded joints — Recommended practice for liquid penetrant testing [Withdrawn: replaced with ISO 3452] ISO 3880 Building construction – Stairs – Vocabulary ISO 3880-1:1977 [Withdrawn without replacement] ISO 3881:1977 Building construction — Modular co-ordination — Stairs and stair openings — Co-ordinating dimensions ISO 3882:2003 Metallic and other inorganic coatings — Review of methods of measurement of thickness ISO 3883:1977 Office machines – Line and character capacity of address masters ISO 3884:2025 Solid recovered fuels — Methods for the determination of the content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) [Original draft was Plastic identification card 1] ISO 3885 Solid recovered fuels — Determination of halogens and sulfur by oxidative pyrohydrolytic combustion followed by ion chromatography [under development; original draft with this number unknown ISO 3886:1986 Iron ores — Determination of manganese content — Periodate spectrophotometric method [Withdrawn: replaced with ISO 9682-2] ISO 3887:2007 Steels — Determination of the depth of decarburization ISO 3888 Passenger cars — Test track for a severe lane-change manoeuvre ISO 3888-1:2018 Part 1: Double lane-change ISO 3888-2:2011 Part 2: Obstacle avoidance ISO 3889:2006 Milk and milk products — Specification of Mojonnier-type fat extraction flasks ISO 3890 Milk and milk products — Determination of residues of organochlorine compounds (pesticides) ISO 3890-1:2009 Part 1: General considerations and extraction methods ISO 3890-2:2009 Part 2: Test methods for crude extract purification and confirmation ISO 3891:1978 Acoustics — Procedure for describing aircraft noise heard on the ground [Withdrawn without replacement] ISO 3892:2000 Conversion coatings on metallic materials — Determination of coating mass per unit area — Gravimetric methods ISO 3893:1977 Concrete — Classification by compressive strength [Withdrawn without replacement] ISO 3894:2015 Road vehicles — Wheels/rims for commercial vehicles — Test methods ISO 3895:1986 Road vehicles — Screened and waterproof spark-plug and its connection — Type 2 ISO 3896:1986 Road vehicles — Screened and waterproof spark-plug and its connection — Type 3 ISO 3897:1997 Photography — Processed photographic plates — Storage practices [Withdrawn: replaced with ISO 18918] ISO 3898:2013 Bases for design of structures — Names and symbols of physical quantities and generic quantities ISO 3899:2005 Rubber — Nitrile latex — Determination of residual acrylonitrile content ISO 3900:1995 Rubber — Nitrile latex — Determination of bound acrylonitrile content ISO 3901:2019 Information and documentation – International Standard Recording Code (ISRC) ISO 3902:1990 Shipbuilding and marine structures — Gaskets for rectangular windows and side scuttles ISO 3903:2012 Ships and marine technology — Ships' ordinary rectangular windows ISO 3904:1990 Shipbuilding and marine structures — Clear-view screens ISO 3905:1980 Paints and varnishes — Determination of contrast ratio (opacity) of light coloured paints at a fixed spreading rate (using black and white charts) [Withdrawn: replaced with ISO 6504-3] ISO 3906:1980 Paints and varnishes — Determination of contrast ratio (opacity) of light coloured paints at a fixed spreading rate (using polyester film) [Withdrawn: replaced with ISO 6504-3] ISO 3907:2009 Hardmetals — Determination of total carbon — Gravimetric method ISO 3908:2009 Hardmetals — Determination of insoluble (free) carbon — Gravimetric method ISO 3909:1976 Hardmetals — Determination of cobalt — Potentiometric method ISO 3910:1983 Rubber boots, unlined moulded [Withdrawn without replacement] ISO 3911:2021 Wheels and rims for pneumatic tyres – Vocabulary, designation and marking ISO 3912:1977 Woodruff keys and keyways [Withdrawn without replacement] ISO 3913:1977 Shipbuilding — Welded steel bollards ISO 3914 Textile machinery and accessories — Cylindrical tubes ISO 3914-1:1994 Part 1: Recommended main dimensions ISO 3914-2:1994 Part 2: Dimensions, tolerances and designation of tubes for open-end spinning machines ISO 3914-3:1994 Part 3: Dimensions, tolerances and designation of tubes for tape yarns ISO 3914-4:1994 Part 4: Dimensions, tolerances and designation of tubes for textured yarns [Withdrawn without replacement] ISO 3914-5:1994 Part 5: Dimensions, tolerances and designation of tubes for continuous spin-drawn synthetic filament yarns [Withdrawn without replacement] ISO 3914-6:1994 Part 6: Dimensions, tolerances and designation of tubes for cross-wound packages in winding and twisting [Withdrawn without replacement] ISO 3914-7:1994 Part 7: Dimensions, tolerances and designation of perforated tubes for cheese dyeing ISO 3915:2022 Plastics — Measurement of resistivity of conductive plastics ISO 3916:1977 Shipbuilding — Inland navigation — Rope tubs [Withdrawn without replacement] ISO 3917:2016 Road vehicles — Safety glazing materials — Test methods for resistance to radiation, high temperature, humidity, fire and simulated weathering ISO 3918:2007 Milking machine installations – Vocabulary ISO 3919:2005 Coated abrasives — Flap wheels with shaft ISO 3920:1976 Honing stones of square section — Designation and dimensions [Withdrawn: replaced with ISO 603-(1-16)] ISO 3921:1976 Honing stones of rectangular section — Designation and dimensions [Withdrawn: replaced with ISO 603-(1-16)] ISO 3922:1978 Continuous mechanical handling equipment — Rotary vane feeder — Dimensional specifications [Withdrawn without replacement] ISO 3923 Metallic powders — Determination of apparent density ISO 3923-1:2018 Part 1: Funnel method ISO 3923-2:1981 Part 2: Scott volumeter method ISO 3923-3:1986 Part 3: Oscillating funnel method [Withdrawn without replacement] ISO 3924:2019 Petroleum products — Determination of boiling range distribution — Gas chromatography method ISO 3925:2014 Unsealed radioactive substances — Identification and documentation ISO 3926:1980 Shipbuilding — Inland navigation — Couplings for oil and fuel reception — Mating dimensions [Withdrawn without replacement] ISO 3927:2017 Metallic powders, excluding powders for hardmetals — Determination of compressibility in uniaxial compression ISO 3928:2016 Sintered metal materials, excluding hardmetals — Fatigue test pieces ISO 3929:2003 Road vehicles — Measurement methods for exhaust gas emissions during inspection or maintenance ISO 3930:2000 Instruments for measuring vehicle exhaust emissions [Withdrawn without replacement] ISO 3931 Fibre building boards – Determination of transversal internal bond [Rejected draft] ISO 3932:1976 Textiles — Woven fabrics — Measurement of width of pieces [Withdrawn: replaced with ISO 22198] ISO 3933:1976 Textiles — Woven fabrics — Measurement of length of pieces [Withdrawn: replaced with ISO 22198] ISO 3934:2021 Rubber, vulcanized and thermoplastic — Preformed gaskets used in buildings — Classification, specifications and test methods ISO 3935:1977 Shipbuilding — Inland navigation — Fire-fighting water system — Pressures [Withdrawn without replacement] ISO 3936:1993 Reduction sleeves with tenon drive with external and internal 7/24 taper — Dimensions ISO 3937 Cutter arbors with tenon drive ISO 3937-1:2008 Part 1: Dimensions of Morse taper ISO 3937-2:2008 Part 2: Dimensions of 7/24 taper ISO 3937-3:2008 Part 3: Dimensions of hollow taper interface with flange contact surface ISO 3938:1986 Hydraulic fluid power — Contamination analysis — Method for reporting analysis data [Withdrawn without replacement] ISO 3939:1977 Fluid power systems and components — Multiple lip packing sets — Methods for measuring stack heights ISO 3940:1977 Tapered die-sinking cutters with parallel shanks ISO 3941:1977 Classification of fires ISO 3942:1976 Photographic grade sodium carbonate, monohydrate — Specification [Withdrawn: replaced with ISO 424] ISO 3943:1993 Photography — Processing chemicals — Specifications for anhydrous sodium acetate ISO 3944:1992 Fertilizers — Determination of bulk density (loose) ISO 3945:1985 Mechanical vibration of large rotating machines with speed range from 10 to 200 r/s — Measurement and evaluation of vibration severity in situ [Withdrawn: replaced with ISO 10816-1] ISO 3946:1982 Starches and derived products — Determination of total phosphorus content — Spectrophotometric method ISO 3947:1977 Starches, native or modified — Determination of total fat content ISO 3948:1977 Shipbuilding — Inland vessels — Compressed-air systems — Pressure ranges [Withdrawn without replacement] ISO 3949:2020 Plastics hoses and hose assemblies — Textile-reinforced types for hydraulic applications — Specification ISO 3950:2016 Dentistry – Designation system for teeth and areas of the oral cavity ISO 3951 Sampling procedures for inspection by variables ISO 3951-1:2022 Part 1: Specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristic and a single AQL ISO 3951-2:2013 Part 2: General specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection of independent quality characteristics ISO 3951-3:2007 Part 3: Double sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ISO 3951-4:2011 Part 4: Procedures for assessment of declared quality levels ISO 3951-5:2006 Part 5: Sequential sampling plans indexed by acceptance quality limit (AQL) for inspection by variables (known standard deviation) ISO 3952 Kinematic diagrams – Graphical symbols ISO 3952-1:1981 (Motion of links of mechanisms; Kinematic pairs; Links and connections of their components; Linkage of bars and their links) ISO 3952-2:1981 (Friction and gear mechanisms; Cam mechanisms) ISO 3952-3:1979 (Maltese and ratchet mechanisms; Couplings and brakes) ISO 3952-4:1984 (Miscellaneous mechanisms and their components) ISO 3953:2011 Metallic powders — Determination of tap density ISO 3954:2007 Powders for powder metallurgical purposes — Sampling ISO 3955:1977 Sintered metal materials, excluding hardmetals — Sampling [Withdrawn without replacement] ISO/TR 3956:1975 Principles of structural fire-engineering design with special regard to the connection between real fire exposure and the heating conditions of the standard fire-resistance test (ISO 834) ISO 3957:2025 Reaction to fire tests — Façades — Measurement of heat and smoke generation in severe exterior fire scenarios [original draft Graphic symbols — Index, survey, and compilation of the single sheets became ISO 7000] ISO 3958:1996 Passenger cars — Driver hand-control reach ISO 3959:1977 Green bananas — Ripening conditions ISO 3960:2017 Animal and vegetable fats and oils — Determination of peroxide value — Iodometric (visual) endpoint determination ISO 3961:2018 Animal and vegetable fats and oils — Determination of iodine value ISO 3962:1977 Materials and equipment for petroleum and natural gas industries — Tool joints for steel drill pipe for oil or natural gas wells [Withdrawn without replacement] ISO 3963:1977 Fertilizers — Sampling from a conveyor by stopping the belt ISO 3964:2016 Dentistry — Coupling dimensions for handpiece connectors ISO 3965:1990 Agricultural wheeled tractors — Maximum speeds — Method of determination ISO 3966:2020 Measurement of fluid flow in closed conduits – Velocity area method using Pitot static tubes ISO 3967 Petroleum products – Determination of density and relative density – Bingham pyknometer method [Rejected draft] ISO 3968:2017 Hydraulic fluid power — Filters — Evaluation of differential pressure versus flow ISO 3969:1979 Shipbuilding — Inland vessels — Operational documentation [Withdrawn without replacement] ISO 3970:1977 Modular units for machine tool construction — Integral way columns — Floor-mounted type ISO 3971:1977 Rice milling — Symbols and equivalent terms [Withdrawn without replacement] ISO 3972:2011 Sensory analysis — Methodology — Method of investigating sensitivity of taste ISO 3973:1996 Living animals for slaughter — Vocabulary — Bovines [Withdrawn without replacement] ISO 3974:1977 Definitions of living animals for slaughter — Ovines ISO 3975:1977 Definitions of living animals for slaughter — Horses [Withdrawn without replacement] ISO 3976:2006 Milk fat — Determination of peroxide value ISO 3977 Gas turbines – Procurement ISO 3978:1976 Aluminium and aluminium alloys — Determination of chromium — Spectrophotometric method using diphenylcarbazide, after extraction ISO 3979:1977 Aluminium and aluminium alloys — Determination of nickel — Spectrophotometric method using dimethylglyoxime [Withdrawn without replacement] ISO 3980:1977 Aluminium and aluminium alloys — Determination of copper — Atomic absorption spectrophotometric method ISO 3981:1977 Aluminium and aluminium alloys — Determination of nickel — Atomic absorption spectrophotometric method ISO 3982 Chemical analysis of aluminum and its alloys — Complexometric determination of magnesium [Rejected draft] ISO 3983:1977 Cereals and cereal products — Determination of alpha-amylase activity — Colorimetric method [Withdrawn without replacement] ISO 3984:2004 Road vehicles — Rear moving barrier impact test procedure [Withdrawn without replacement] ISO/TR 3985:2021 Biotechnology — Data publication — Preliminary considerations and concepts [Original draft with this number unknown] ISO 3986 Petroleum products — Lubricating wax — Determination of cone penetration [Rejected draft] ISO 3987:2010 Petroleum products — Determination of sulfated ash in lubricating oils and additives ISO 3988 Determination of Spontaneous ignition temperature [Rejected draft] ISO 3989 Measurement of airborne noise emitted by compressor units including prime movers [Rejected draft] ISO 3990:2023 Dentistry — Evaluation of antibacterial activity of dental restorative materials, luting cements, fissure sealants and orthodontic bonding or luting materials [original draft was Modular co-ordination — Sizes for co-ordinating lengths and widths of openings in the horizontal plane] ISO 3991:2025 Agricultural machinery — Robotic feed systems — Safety [original draft was Modular co-ordination — Sizes for co-ordinating heights of openings in the vertical plane] ISO 3992 Petroleum waxes — Determination of needle penetration [Rejected draft] ISO 3993:1984 Liquefied petroleum gas and light hydrocarbons — Determination of density or relative density — Pressure hydrometer method ISO 3994:2014 Plastics hoses — Helical-thermoplastic-reinforced thermoplastics hoses for suction and discharge of aqueous materials — Specification ISO 3995:1985 Metallic powders — Determination of green strength by transverse rupture of rectangular compacts ISO 3996:1995 Road vehicles — Brake hose assemblies for hydraulic braking systems used with non-petroleum-base brake fluid ISO 3997 Bitumen and bituminous binders – Determination of needle penetration [Rejected draft] ISO 3998:1977 Textiles — Determination of resistance to certain insect pests ISO 3999:2004 Radiation protection — Apparatus for industrial gamma radiography — Specifications for performance, design and tests
Sources: en.wikipedia.org
=== Precursors to chemicals === By the process of cracking, alkanes can be converted to alkenes. Simple alkenes are precursors to polymers, such as polyethylene and polypropylene. When the cracking is taken to extremes, alkanes can be converted to carbon black, which is a significant tire component. Chlorination of methane gives chloromethanes, which are used as solvents and building blocks for complex compounds. Similarly treatment of methane with sulfur gives carbon disulfide. Still other chemicals are prepared by reaction with sulfur trioxide and nitric oxide.
In February 2022, journalist Marwan Bishara held the US and Russia responsible for pursuing "their own narrow interests", including then-US president Trump's recognition of Jerusalem as capital of Israel as well as Putin's Russian invasion of Ukraine, and for "pav[ing] the way for, well, another Cold War".
Emboldened by the footage, Aditya gets reinstated by the police by proving his physical and mental stability. He then traces Ajay's true biological origins to Hari. Attempting to evade Aditya, Hari organises the murders of numerous police officers. Undeterred, Aditya traces Hari's location to an old office building of Mumbai Media that media tycoon Pramod Gupta owns, who is one of Hari's associates. With the help of the police, Aditya launches a raid on the complex. He kills Hari's goons and captures Gupta but fails to capture Hari, who retreats to the site of his earlier massacre and lures Aditya by holding the families of the murdered police officers hostage at gunpoint. Aditya fights with Hari and wins. Hari attempts to shoot Aditya, but he throws a knife at Hari's neck then stabs him repeatedly to death. As Aditya walks out of the police station, a young boy dressed in a police uniform looks at him and salutes with a smile. Aditya returns the smile and salute.
== Mechanism == Antibodies against voltage-gated potassium channels (VGKC), which are detectable in about 40% of patients with acquired neuromytonia, have been implicated in Morvan's pathophysiology. Raised serum levels of antibodies to VGKCs have been reported in three patients with Morvan's Syndrome. Binding of serum from a patient with Morvan's Syndrome to the hippocampus in a similar pattern of antibodies to known VGKC suggest that these antibodies can also cause CNS dysfunction. Additional antibodies against neuromuscular junction channels and receptors have also been described. Experimental evidence exists that these anti-VGKC antibodies cause nerve hyperexcitability by suppression of voltage gated K+ outward currents, whereas other, yet undefined humoral factors have been implicated in anti-VGKC antibody negative neuromyotonia. It is believed that antibodies to the Shaker-type K+ channels (the Kv1 family) are the type of potassium channel most strongly associated with acquired neuromyotonia and Morvan's Syndrome. Whether VGKC antibodies play a pathogenic role in the encephalopathy as they do in the peripheral nervous system is as yet unclear. It has been suggested that the VGKC antibodies may cross the blood–brain barrier and act centrally, binding predominantly to thalamic and striatal neurons causing encephalopathic and autonomic features.
=== Hydrolysis === Amides hydrolyse in hot alkali as well as in strong acidic conditions. Acidic conditions yield the carboxylic acid and the ammonium ion while basic hydrolysis yield the carboxylate ion and ammonia. The protonation of the initially generated amine under acidic conditions and the deprotonation of the initially generated carboxylic acid under basic conditions render these processes non-catalytic and irreversible. Electrophiles other than protons react with the carbonyl oxygen. This step often precedes hydrolysis, which is catalyzed by both Brønsted acids and Lewis acids. Peptidase enzymes and some synthetic catalysts often operate by attachment of electrophiles to the carbonyl oxygen.
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.
Mass spectrometry combined with liquid chromatography provides both molecular weight confirmation and a measure of related impurities. Tandem mass spectrometry adds sequence information. A purity percentage reported without a mass measurement does not confirm what the material is.