The short version of Enkephalinase fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-17 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Chromatography is a physical method of separation that distributes the components you want to separate between two phases, one stationary (stationary phase), the other (the mobile phase) moving in a definite direction. Cold ethanol precipitation, developed by Cohn in 1946, manipulates pH, ionic strength, ethanol concentration and temperature to precipitate different protein fractions from plasma. Chromatographic techniques utilise ion exchange, gel filtration and affinity resins to separate proteins. Since the 1980s it has emerged as an effective method of purifying blood components for therapeutic use.
== ISO 8000 – ISO 8999 == ISO 8000 Data quality ISO 8002:1986 Mechanical vibrations – Land vehicles – Method for reporting measured data ISO 8015:2011 Geometrical product specifications (GPS) – Fundamentals – Concepts, principles and rules ISO 8041:2005 Human response to vibration - Measuring instrumentation ISO 8041-1:2017 Part 1: General purpose vibration meters ISO 8042:1988 Shock and vibration measurements – Characteristics to be specified for seismic pick-ups ISO 8044:2015 Corrosion of metals and alloys – Basic terms and definitions ISO 8048:1984 Technical drawings – Construction drawings – Representation of views, sections and cuts ISO 8049:2016 Ferronickel shot - Sampling for analysis ISO 8050:1988 Ferronickel ingots or pieces - Sampling for analysis ISO 8062 Geometrical product specifications (GPS) - Dimensional and geometrical tolerances for moulded parts ISO 8062-1:2007 Part 1: Vocabulary ISO/TS 8062-2:2013 Part 2: Rules ISO 8062-3:2007 Part 3: General dimensional and geometrical tolerances and machining allowances for castings ISO 8062-4:2017 Part 4: General tolerances for castings using profile tolerancing in a general datum system ISO 8063 Information processing – Data interchange on 6,30 mm (0.25 in) wide magnetic tape cartridge using IMFM recording at 252 ftpmm (6 400 ftpi) ISO 8063-1:1986 Part 1: Mechanical, physical and magnetic properties ISO 8063-2:1986 Part 2: Track format and method of recording for data interchange in start/stop mode ISO 8064:1985 Information processing – Reels for 12,7 mm (0,5 in) wide magnetic tapes – Sizes 16, 18 and 22 ISO/IEC 8072:1996 Information technology – Open systems interconnection – Transport service definition ISO/IEC 8073:1997 Information technology – Open Systems Interconnection – Protocol for providing the connection-mode transport service ISO 8088:1994 Equipment for olive cultivation and olive oil production – Vocabulary ISO 8090:1990 Cycles – Terminology ISO 8107:1993 Nuclear power plants - Maintainability - Terminology ISO 8109:1990 Banking and related financial services – Securities – Format of Eurobonds ISO 8114:1990 Textile machinery and accessories – Spindles for ring-spinning and doubling machines – List of equivalent terms ISO 8116 Textile machinery and accessories – Beams for winding ISO 8116-1:1995 Part 1: General vocabulary ISO 8119 Textile machinery and accessories – Needles for knitting machines – Terminology ISO 8119-1:1989 Part 1: Latch-type needles ISO 8119-2:1989 Part 2: Bearded needles ISO 8119-3:1992 Part 3: Compound needles ISO/IEC 81346: Industrial systems, installations and equipment and industrial products – structuring principles and reference designations ISO 8147:1995 Shipbuilding and marine structures – Derrick rigs and component parts – Vocabulary ISO 8152:1984 Earth-moving machinery – Operation and maintenance – Training of mechanics ISO 8153 Aerospace fluid systems and components – Vocabulary ISO 8153-1:2009 Part 1: Hose assemblies ISO 8157:2015 Fertilizers and soil conditioners – Vocabulary ISO 8159:1987 Textiles – Morphology of fibres and yarns – Vocabulary ISO 8160:1987 Textiles – Textured filament yarns – Vocabulary ISO 8178 Reciprocating internal combustion engines - Exhaust emission measurement ISO 8180 Ductile iron pipelines – Polyethylene sleeving for site application ISO 8199:2005 Water quality – General guidance on the enumeration of micro-organisms by culture ISO/IEC 8208:2000 Information technology – Data communications – X.25 Packet Layer Protocol for Data Terminal Equipment ISO/IEC 8211:1994 Information technology - Specification for a data descriptive file for information interchange ISO 8217:2017 Petroleum products - Fuels (class F) - Specifications of marine fuels ISO 8229:1991 Operations and baths relating to dry-cleaning machines – Vocabulary ISO 8277:2013 Ships and marine technology – Pipework and machinery – Information transfer ISO 8297:1994 Acoustics – Determination of sound power levels of multisource industrial plants for evaluation of sound pressure levels in the environment – Engineering method ISO 8316:1987 Measurement of liquid flow in closed conduits – Method by collection of the liquid in a volumetric tank ISO 8317:2015 Child-resistant packaging - Requirements and testing procedures for reclosable packages ISO 8319 Orthopaedic instruments – Drive connections ISO 8319-1:1996 Part 1: Keys for use with screws with hexagon socket heads ISO 8319-2:1986 Part 2: Screwdrivers for single slot head screws, screws with cruciate slot and cross-recessed head screws ISO/IEC 8326:1996 Information technology – Open Systems Interconnection – Session service definition ISO/IEC 8327 Information technology – Open Systems Interconnection – Connection-oriented Session protocol ISO/IEC 8327-1:1996 Protocol specification ISO/IEC 8327-2:1996 Protocol Implementation Conformance Statement (PICS) proforma ISO 8330:2014 Rubber and plastics hoses and hose assemblies - Vocabulary ISO 8333:1985 Liquid flow measurement in open channels by weirs and flumes – V-shaped broad-crested weirs ISO 8343:1985 Ferronickel - Determination of silicon content - Gravimetric method ISO/IEC 8348:2002 Information technology – Open Systems Interconnection – Network service definition ISO 8362 Injection containers and accessories ISO 8362-1:2009 Part 1: Injection vials made of glass tubing ISO 8362-2:2015 Part 2: Closures for injection vials ISO 8362-3:2001 Part 3: Aluminium caps for injection vials ISO 8362-4:2011 Part 4: Injection vials made of moulded glass ISO 8362-5:2016 Part 5: Freeze drying closures for injection vials ISO 8362-6:2010 Part 6: Caps made of aluminium-plastics combinations for injection vials ISO 8362-7:2006 Part 7: Injection caps made of aluminium-plastics combinations without overlapping plastics part ISO/TR 8363:1997 Measurement of liquid flow in open channels — General guidelines for selection of method [Withdrawn: replaced by ISO 18365] ISO 8368:1999 Hydrometric determinations – Flow measurements in open channels using structures – Guidelines for selection of structure ISO 8373:2012 Manipulating industrial robots – Vocabulary ISO 8378 Information processing – Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7 958 ftprad, 3,8 tpmm (96 tpi), on both sides ISO 8378-1:1986 Part 1: Dimensional, physical and magnetic characteristics ISO 8378-2:1986 Part 2: Track format A ISO 8378-3:1986 Part 3: Track format B ISO 8384:2000 Ships and marine technology – Dredgers – Vocabulary ISO 8388:1998 Knitted fabrics – Types – Vocabulary ISO 8421 Fire protection - Vocabulary ISO 8421-1:1987 Part 1: General terms and phenomena of fire ISO 8421-2:1987 Part 2: Structural fire protection ISO 8421-6:1987 Part 6: Evacuation and means of escape ISO 8421-7:1987 Part 7: Explosion detection and suppression means ISO 8422:2006 Sequential sampling plans for inspection by attributes ISO 8423:2008 Sequential sampling plans for inspection by variables for percent nonconforming (known standard deviation) ISO 8429:1986 Optics and optical instruments – Ophthalmology – Graduated dial scale ISO 8439:1990 Forms design - Basic layout ISO 8440:1986 Location of codes in trade documents ISO/IEC 8441 Information technology – High density digital recording (HDDR) ISO/IEC 8441-1:1991 Part 1: Unrecorded magnetic tape for (HDDR) applications ISO/IEC 8441-2:1991 Part 2: Guide for interchange practice ISO 8459:2009 Information and documentation - Bibliographic data element directory for use in data exchange and enquiry ISO 8462 Information processing – Data interchange on 6,30 mm (0.25 in) magnetic tape cartridge using GCR recording at 394 ftpmm (10 000 ftpi), 39 cpmm (1 000 cpi) ISO 8462-1:1986 Part 1: Mechanical, physical and magnetic properties ISO 8462-2:1986 Part 2: Streaming mode ISO/IEC 8473 Information technology – Protocol for providing the connectionless-mode network service ISO/IEC 8473-1:1998 Protocol specification ISO/IEC 8473-2:1996 Part 2: Provision of the underlying service by an ISO/IEC 8802 subnetwork ISO/IEC 8473-3:1995 Provision of the underlying service by an X.25 subnetwork ISO/IEC 8473-4:1995 Provision of the underlying service by a subnetwork that provides the OSI data link service ISO/IEC 8473-5:1997 Provision of the underlying service by ISDN circuit-switched B-channels ISO/IEC 8480:1995 Information technology – Telecommunications and information exchange between systems – DTE/DCE interface back-up control operation using ITU-T Recommendation V.24 interchange circuits ISO/IEC 8481:1996 Information technology – Telecommunications and information exchange between systems – DTE to DTE direct connections ISO/IEC 8482:1993 Information technology – Telecommunications and information exchange between systems – Twisted pair multipoint interconnections ISO/IEC 8484:2014 Information technology – Magnetic stripes on savingsbooks ISO 8485:1989 Programming languages - APL ISO 8498:1990 Woven fabrics – Description of defects – Vocabulary ISO 8499:2003 Knitted fabrics – Description of defects – Vocabulary ISO 8501 Preparation of steel substrates before application of paints and related products – Visual assessment of surface cleanliness ISO 8501-1:2007 Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings ISO 8501-2:1994 Part 2: Preparation grades of previously coated steel substrates after localized removal of previous coatings ISO 8501-3:2006 Part 3: Preparation grades of welds, edges and other areas with surface imperfections ISO 8501-4:2006 Part 4: Initial surface conditions, preparation grades and flash rust grades in connection with high-pressure water jetting ISO 8502 Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness ISO 8502-2:2017 Part 2: Laboratory determination of chloride on cleaned surfaces ISO 8502-3:2017 Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method) ISO 8502-4:2017 Part 4: Guidance on the estimation of the probability of condensation prior to paint application ISO 8502-5:1998 Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method ISO 8502-6:2006 Part 6: Extraction of soluble contaminants for analysis - The Bresle method ISO 8502-9:1998 Part 9: Field method for the conductometric determination of water-soluble salts ISO 8502-11:2006 Part 11: Field method for the turbidimetric determination of water-soluble sulfate ISO 8503 Preparation of steel substrates before application of paints and related products - Surface roughness characteristics of blast-cleaned steel substrates ISO 8503-1:2012 Part 1: Specifications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces ISO 8503-2:2012 Part 2: Method for the grading of surface profile of abrasive blast-cleaned steel - Comparator procedure ISO 8503-3:2012 Part 3: Method for the calibration of ISO surface profile comparators and for the determination of surface profile - Focusing microscope procedure ISO 8503-4:2012 Part 4: Method for the calibration of ISO surface profile comparators and for the determination of surface profile - Stylus instrument procedure ISO 8503-5:2017 Part 5: Replica tape method for the determination of the surface profile ISO 8504 Preparation of steel substrates before application of paints and related products - Surface preparation methods ISO 8504-1:2000 Part 1: General principles ISO 8504-2:2000 Part 2: Abrasive blast-cleaning ISO 8504-3:1993 Part 3: Hand- and power-tool cleaning ISO 8506:2024 Information technology — Automatic identification and data capture technology — AIDC application in industrial construction ISO 8512 Surface plates ISO 8512-1:1990 Part 1: Cast iron ISO 8512-2:1990 Part 2: Granite ISO/TR 8517:1988 Rubber- or plastics-covered rollers – Glossary ISO 8525:2008 Airborne noise emitted by machine tools – Operating conditions for metal-cutting machines ISO 8528 Reciprocating internal combustion engine driven alternating current generating sets ISO 8528-1:2005 Part 1: Application, ratings and performance ISO 8528-2:2005 Part 2: Engines ISO 8528-3:2005 Part 3: Alternating current generators for generating sets ISO 8528-4:2005 Part 4: Controlgear and switchgear ISO 8528-5:2013 Part 5: Generating sets ISO 8528-6:2005 Part 6: Test methods ISO 8528-7:2017 Part 7: Technical declarations for specification and design ISO 8528-8:2016 Part 8: Requirements and tests for low-power generating sets ISO 8528-9:2017 Part 9: Measurement and evaluation of mechanical vibrations ISO 8528-10:1998 Part 10: Measurement of airborne noise by the enveloping surface method ISO 8528-12:1997 Part 12: Emergency power supply to safety services ISO 8528-13:2016 Part 13: Safety ISO 8529 Reference neutron radiations ISO 8529-1:2001 Part 1: Characteristics and methods of production ISO 8529-2:2000 Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field ISO 8529-3:1998 Part 3: Calibration of area and personal dosimeters and determination of response as a function of energy and angle of incidence ISO 8532:1995 Securities – Format for transmission of certificate numbers ISO 8536 Infusion equipment for medical use ISO 8536-1:2011 Part 1: Infusion glass bottles ISO 8536-2:2010 Part 2: Closures for infusion bottles ISO 8536-3:2009 Part 3: Aluminium caps for infusion bottles ISO 8536-4:2010 Part 4: Infusion sets for single use, gravity feed ISO 8536-5:2004 Part 5: Burette infusion sets for single use, gravity feed ISO 8536-6:2016 Part 6: Freeze drying closures for infusion bottles ISO 8536-7:2009 Part 7: Caps made of aluminium-plastics combinations for infusion bottles ISO 8536-8:2015 Part 8: Infusion sets for single use with pressure infusion apparatus ISO 8536-9:2015 Part 9: Fluid lines for single use with pressure infusion equipment ISO 8536-10:2015 Part 10: Accessories for fluid lines for single use with pressure infusion equipment ISO 8536-11:2015 Part 11: Infusion filters for single use with pressure infusion equipment ISO 8536-12:2007 Part 12: Check valves ISO 8536-13:2016 Part 13: Graduated flow regulators for single use with fluid contact ISO 8536-14:2016 Part 14: Clamps and flow regulators for transfusion and infusion equipment without fluid contact ISO 8537:2016 Sterile single-use syringes, with or without needle, for insulin ISO 8540:1993 Open front mechanical power presses - Vocabulary ISO 8548 Prosthetics and orthotics – Limb deficiencies ISO 8548-1:1989 Part 1: Method of describing limb deficiencies present at birth ISO 8548-2:1993 Part 2: Method of describing lower limb amputation stumps ISO 8548-3:1993 Part 3: Method of describing upper limb amputation stumps ISO 8548-4:1998 Part 4: Description of causal conditions leading to amputation ISO 8548-5:2003 Part 5: Description of the clinical condition of the person who has had an amputation ISO 8549 Prosthetics and orthotics - Vocabulary ISO 8549-1:1989 Part 1: General terms for external limb prostheses and external orthoses ISO 8549-2:1989 Part 2: Terms relating to external limb prostheses and wearers of these prostheses ISO 8549-3:1989 Part 3: Terms relating to external orthoses ISO 8549-4:2014 Part 4: Terms relating to limb amputation ISO/TR 8550 Guidance on the selection and usage of acceptance sampling systems for inspection of discrete items in lots ISO/TR 8550-1:2007 Part 1: Acceptance sampling ISO/TR 8550-2:2007 Part 2: Sampling by attributes ISO/TR 8550-3:2007 Part 3: Sampling by variables ISO 8551:2003 Prosthetics and orthotics – Functional deficiencies – Description of the person to be treated with an orthosis, clinical objectives of treatment, and functional requirements of the orthosis ISO 8552:2004 Milk – Estimation of psychrotrophic microorganisms – Colony-count technique at 21 degrees C (Rapid method) ISO 8553:2004 Milk – Enumeration of microorganisms – Plate-loop technique at 30 degrees C ISO 8559:1989 Garment construction and anthropometric surveys – Body dimensions [Withdrawn: replaced by ISO 8559-1:2017] ISO 8559 Size designation of clothes ISO 8559-1:2017 Part 1: Anthropometric definitions for body measurement ISO 8559-2:2017 Part 2: Primary and secondary dimension indicators ISO 8560:1986 Technical drawings – Construction drawings – Representation of modular sizes, lines and grids ISO 8568:2007 Mechanical shock – Testing machines – Characteristics and performance ISO 8571 Information processing systems - Open Systems Interconnection - File Transfer, Access and Management ISO 8571-1:1988 Part 1: General introduction ISO 8571-2:1988 Part 2: Virtual Filestore Definition ISO 8571-3:1988 Part 3: File Service Definition ISO 8571-4:1988 Part 4: File Protocol Specification ISO/IEC 8571-5:1990 Part 5: Protocol Implementation Conformance Statement Proforma ISO 8573 Compressed air ISO 8573-1:2010 Contaminants and purity classes ISO 8573-2:2007 Test methods for oil aerosol content ISO 8573-3:1999 Test methods for measurement of humidity ISO 8573-4:2001 Test methods for solid particle content ISO 8573-5:2001 Test methods for oil vapour and organic solvent content ISO 8573-6:2003 Test methods for gaseous contaminant content ISO 8573-7:2003 Test method for viable microbiological contaminant content ISO 8573-8:2004 Test methods for solid particle content by mass concentration ISO 8573-9:2004 Test methods for liquid water content ISO 8579 Acceptance code for gear units ISO 8579-1:2002 Part 1: Test code for airborne sound ISO 8583 Financial transaction card originated messages – Interchange message specifications ISO 8586:2012 Sensory analysis – General guidelines for the selection, training and monitoring of selected assessors and expert sensory assessors ISO 8596:2009 Ophthalmic optics – Visual acuity testing – Standard optotype and its presentation ISO 8598 Optics and optical instruments – Focimeters ISO 8598-1:2014 Part 1: General purpose instruments ISO 8600 Endoscopes – Medical endoscopes and endotherapy devices ISO 8600-1:2015 Part 1: General requirements ISO 8600-2:2015 Part 2: Particular requirements for rigid bronchoscopes ISO 8600-3:1997 Part 3: Determination of field of view and direction of view of endoscopes with optics ISO 8600-4:2014 Part 4: Determination of maximum width of insertion portion ISO 8600-5:2005 Part 5: Determination of optical resolution of rigid endoscopes with optics ISO 8600-6:2005 Part 6: Vocabulary ISO 8600-7:2012 Part 7: Basic requirements for medical endoscopes of water-resistant type ISO 8601:2019 Data elements and interchange formats – Information interchange – Representation of dates and times ISO/IEC 8602:1995 Information technology – Protocol for providing the OSI connectionless-mode transport service ISO 8604:1988 Plastics – Prepregs – Definitions of terms and symbols for designations ISO 8608:2016 Mechanical vibration – Road surface profiles – Reporting of measured data ISO 8612:2009 Ophthalmic instruments – Tonometers ISO/IEC 8613 Information technology – Open Document Architecture (ODA) and interchange format ISO 8614:1997 Ski bindings – Vocabulary ISO 8615:1991 Implants for surgery – Fixation devices for use in the ends of the femur in adults ISO 8624:2011 Ophthalmic optics – Spectacle frames – Measuring system and terminology ISO 8625 Aerospace – Fluid systems – Vocabulary ISO 8625-1:1993 Part 1: General terms and definitions related to pressure ISO 8625-2:1991 Part 2: General terms and definitions relating to flow ISO 8625-3:1991 Part 3: General terms and definitions relating to temperature ISO 8625-4:2011 Part 4: General terms and definitions relating to control/actuation systems ISO 8626:1989 Servo-hydraulic test equipment for generating vibration – Method of describing characteristics ISO 8630 Information processing – Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, on 80 tracks on each side ISO 8630-1:1987 Part 1: Dimensional, physical and magnetic characteristics ISO 8630-2:1987 Part 2: Track format A for 77 tracks ISO 8630-3:1987 Part 3: Track format B for 80 tracks ISO/IEC 8631:1989 Information technology - Program constructs and conventions for their representation ISO/IEC 8632 Information technology – Computer graphics – Metafile for the storage and transfer of picture description information ISO/IEC 8632-1:1999 Part 1: Functional specification ISO/IEC 8632-2:1992 Part 2: Character encoding [withdrawn 2001-06-21] ISO/IEC 8632-3:1999 Part 3: Binary encoding ISO/IEC 8632-4:1999 Part 4: Clear text encoding ISO 8637:2010 Cardiovascular implants and extracorporeal systems – Haemodialysers, haemodiafilters, haemofilters and haemoconcentrators ISO 8638:2010 Cardiovascular implants and extracorporeal systems – Extracorporeal blood circuit for haemodialysers, haemodiafilters and haemofilters ISO 8640 Textile machinery and accessories – Flat warp knitting machines ISO 8640-1:2004 Part 1: Vocabulary of basic structure and knitting elements ISO 8640-2:2004 Part 2: Vocabulary of warp let-off, fabric take-up and batching ISO 8640-3:2002 Part 3: Vocabulary of patterning devices ISO 8640-4:1996 Part 4: Stitch bonding machines and stitch bonding devices ISO 8648:1988 Information processing systems – Open Systems Interconnection – Internal organization of the Network Layer ISO/IEC 8650 Information technology – Open Systems Interconnection – Protocol specification for the Association Control Service Element ISO/IEC 8650-2:1997 Protocol Implementation Conformance Statement (PICS) proforma ISO 8651 Information technology – Computer graphics – Graphical Kernel System (GKS) language bindings ISO 8651-1:1988 Part 1: FORTRAN ISO 8651-2:1988 Part 2: Pascal ISO 8651-3:1988 Part 3: Ada ISO/IEC 8651-4:1995 Part 4: C ISO/IEC 8652:2012 Information technology – Programming languages – Ada ISO 8653:1986 Jewellery – Ring-sizes – Definition, measurement and designation ISO 8655 Piston-operated volumetric apparatus ISO 8655-1:2002 Part 1: Terminology, general requirements and user recommendations ISO 8655-2:2002 Part 2: Piston pipettes ISO 8655-3:2002 Part 3: Piston burettes ISO 8655-4:2002 Part 4: Dilutors ISO 8655-5:2002 Part 5: Dispensers ISO 8655-6:2002 Part 6: Gravimetric methods for the determination of measurement error ISO 8655-7:2005 Part 7: Non-gravimetric methods for the assessment of equipment performance ISO 8669 Urine collection bags ISO 8669-1:1988 Part 1: Vocabulary ISO 8670 Ostomy collection bags ISO 8670-1:1988 Part 1: Vocabulary ISO 8691 Petroleum products – Low levels of vanadium in liquid fuels – Determination by flameless atomic absorption spectrometry after ashing ISO 8695:2010 Tools for pressing - Punches - Nomenclature and terminology ISO/TR 8713:2012 Electrically propelled road vehicles – Vocabulary ISO 8769:2016 Reference sources - Calibration of surface contamination monitors - Alpha-, beta- and photon emitters ISO 8777:1993 Information and documentation - Commands for interactive text searching ISO 8784 Pulp, paper and board – Microbiological examination ISO 8784-1:2014 Part 1: Enumeration of bacteria and bacterial spores based on disintegration ISO 8785:1998 Geometrical Product Specification (GPS) - Surface imperfections - Terms, definitions and parameters ISO 8790:1987 Information processing systems - Computer system configuration diagram symbols and conventions ISO/IEC 8802 Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements ISO/IEC/IEEE 8802-A:2015 Part A: Overview and architecture ISO/IEC TR 8802-1:2001 Part 1: Overview of Local Area Network Standards ISO/IEC/IEEE 8802-1Q:2016 Part 1Q: Bridges and bridged networks ISO/IEC/IEEE 8802-1X:2013 Part 1X: Port-based network access control ISO/IEC/IEEE 8802-1AB:2017 Part 1AB: Station and media access control connectivity discovery ISO/IEC/IEEE 8802-1AE:2013 Part 1AE: Media access control (MAC) security ISO/IEC/IEEE 8802-1AR:2014 Part 1AR: Secure device identity ISO/IEC/IEEE 8802-1AS:2014 Part 1AS: Timing and synchronization for time-sensitive applications in bridged local area networks ISO/IEC/IEEE 8802-1AX:2016 Part 1AX: Link aggregation ISO/IEC/IEEE 8802-1BA:2016 Part 1BA: Audio video bridging (AVB) systems ISO/IEC/IEEE 8802-1BR:2016 Part 1BR: Virtual bridged local area networks – Bridge port extension ISO/IEC 8802-2:1998 Part 2: Logical link control ISO/IEC/IEEE 8802-3:2017 Part 3: Standard for Ethernet ISO/IEC/IEEE 8802-3-1:2015 Part 3-1: Standard for management information base (MIB) – Definitions for Ethernet ISO/IEC 8802-5:1998 Part 5: Token Ring access method and physical layer specifications ISO/IEC/IEEE 8802-11:2012 Part 11: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications ISO/IEC/IEEE 8802-15-4:2010 Part 15-4: Wireless medium access control (MAC) and physical layer (PHY) specifications for low-rate wireless personal area networks (WPANs) ISO/IEC/IEEE 8802-22:2015 Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Policies and Procedures for Operation in the TV Bands ISO 8805 Information processing systems – Computer graphics – Graphical Kernel System for Three Dimensions (GKS-3D) functional description ISO/IEC 8806 Information technology – Computer graphics – Graphical Kernel System for Three Dimensions (GKS-3D) language bindings ISO/IEC 8806-4 Part 4: C ISO 8807:1989 Information processing systems – Open Systems Interconnection – LOTOS – A formal description technique based on the temporal ordering of observational behaviour ISO 8811:2000 Earth-moving machinery – Rollers and compactors – Terminology and commercial specifications ISO 8812:2016 Earth-moving machinery – Backhoe loaders – Terminology and commercial specifications ISO 8815:1994 Aircraft – Electrical cables and cable harnesses – Vocabulary ISO/IEC 8822:1994 Information technology – Open Systems Interconnection – Presentation service definition ISO/IEC 8823 Information technology – Open Systems Interconnection – Connection-oriented presentation protocol ISO/IEC 8823-1:1994 Protocol specification ISO/IEC 8823-2:1997 Protocol Implementation Conformance Statement (PICS) proforma ISO/IEC 8824 Information technology – Abstract Syntax Notation One (ASN.1) ISO/IEC 8824-1:2015 Specification of basic notation ISO/IEC 8824-2:2015 Information object specification ISO/IEC 8824-3:2015 Constraint specification ISO/IEC 8824-4:2015 Parameterization of ASN.1 specifications ISO/IEC 8825 Information technology – ASN.1 encoding rules ISO/IEC 8825-1:2015 Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER) ISO/IEC 8825-2:2015 Specification of Packed Encoding Rules (PER) ISO/IEC 8825-3:2015 Specification of Encoding Control Notation (ECN) ISO/IEC 8825-4:2015 XML Encoding Rules (XER) ISO/IEC 8825-5:2015 Mapping W3C XML schema definitions into ASN.1 ISO/IEC 8825-6:2015 Registration and application of PER encoding instructions ISO/IEC 8825-7:2015 Part 7: Specification of Octet Encoding Rules (OER) ISO 8826 Technical drawings – Rolling bearings ISO 8826-1:1989 Part 1: General simplified representation ISO 8826-2:1994 Part 2: Detailed simplified representation ISO 8827:1988 Implants for surgery – Staples with parallel legs for orthopaedic use – General requirements ISO 8828:2014 Implants for surgery – Guidance on care and handling of orthopaedic implants ISO 8835 Inhalational anaesthesia systems ISO 8835-7:2011 Part 7: Anaesthetic systems for use in areas with limited logistical supplies of electricity and anaesthetic gases ISO 8836:2014 Suction catheters for use in the respiratory tract ISO 8843:2005 Aircraft – Crimp-removable contacts for electrical connectors – Identification system ISO 8855:2011 Road vehicles – Vehicle dynamics and road-holding ability – Vocabulary ISO/IEC 8859 Information technology – 8-bit single-byte coded graphic character sets ISO/IEC 8859-1:1998 Part 1: Latin alphabet No. 1 ISO/IEC 8859-2:1999 Part 2: Latin alphabet No. 2 ISO/IEC 8859-3:1999 Part 3: Latin alphabet No. 3 ISO/IEC 8859-4:1998 Part 4: Latin alphabet No. 4 ISO/IEC 8859-5:1999 Part 5: Latin/Cyrillic alphabet ISO/IEC 8859-6:1999 Part 6: Latin/Arabic alphabet ISO/IEC 8859-7:2003 Part 7: Latin/Greek alphabet ISO/IEC 8859-8:1999 Part 8: Latin/Hebrew alphabet ISO/IEC 8859-9:1999 Part 9: Latin alphabet No. 5 ISO/IEC 8859-10:1998 Part 10: Latin alphabet No. 6 ISO/IEC 8859-11:2001 Part 11: Latin/Thai alphabet ISO/IEC 8859-13:1998 Part 13: Latin alphabet No. 7 ISO/IEC 8859-14:1998 Part 14: Latin alphabet No. 8 (Celtic) ISO/IEC 8859-15:1999 Part 15: Latin alphabet No. 9 ISO/IEC 8859-16:2001 Part 16: Latin alphabet No. 10 ISO 8860 Information processing – Data interchange on 90 mm (3.5 in) flexible disk cartridges using modified frequency modulation recording at 7 958 ftprad on 80 tracks on each side ISO 8860-1:1987 Part 1: Dimensional, physical and magnetic characteristics ISO 8860-2:1987 Part 2: Track format ISO 8871 Elastomeric parts for parenterals and for devices for pharmaceutical use ISO 8871-1:2003 Part 1: Extractables in aqueous autoclavates ISO 8871-2:2003 Part 2: Identification and characterization ISO 8871-3:2003 Part 3: Determination of released-particle count ISO 8871-4:2006 Part 4: Biological requirements and test methods ISO 8871-5:2016 Part 5: Functional requirements and testing ISO 8872:2003 Aluminium caps for transfusion, infusion and injection bottles – General requirements and test methods ISO/IEC 8877:1992 Information technology – Telecommunications and information exchange between systems – Interface connector and contact assignments for ISDN Basic Access Interface located at reference points S and T ISO/IEC 8878:1992 Information technology – Telecommunications and information exchange between systems – Use of X.25 to provide the OSI Connection-mode Network Service ISO 8879:1986 Information processing – Text and office systems – Standard Generalized Markup Language (SGML) ISO/IEC 8880 Information technology — Telecommunications and information exchange between systems — Protocol combinations to provide and support the OSI Network Service ISO/IEC 8880-1:1990 Part 1: General principles [Withdrawn: replaced by ISO/IEC TR 13532:1995, now withdrawn without replacement] ISO/IEC 8880-2:1992 Part 2: Provision and support of the connection-mode Network Service [Withdrawn: replaced by ISO/IEC TR 13532:1995, now withdrawn without replacement] ISO/IEC 8880-3:1990 Part 3: Provision and support of the connectionless-mode Network Service [Withdrawn: replaced by ISO/IEC TR 13532:1995, now withdrawn without replacement] ISO/IEC 8881:1989 Information processing systems – Data communications – Use of the X.25 packet level protocol in local area networks ISO/IEC 8882 Information technology – Telecommunications and information exchange between systems – X.25 DTE conformance testing ISO/IEC 8882-1:1996 Part 1: General principles ISO/IEC 8882-2:2000 Part 2: Data link layer conformance test suite ISO/IEC 8882-3:2000 Part 3: Packet layer conformance test suite ISO 8884:1989 Information processing — Text and office systems — Keyboards for multiple Latin-alphabet languages — Layout and operation [Withdrawn: replaced with ISO 9995-(1,7)] ISO 8885:1987 Information processing systems — Data communication — High-level data link control procedures — General purpose XID frame information field content and format [Withdrawn without replacement] ISO/IEC 8886:1996 Information technology – Open Systems Interconnection – Data link service definition ISO 8887 Technical product documentation – Design for manufacturing, assembling, disassembling and end-of-life processing ISO 8887-1:2017 Part 1: General concepts and requirements ISO 8891:1998 Dental casting alloys with noble metal content of at least 25 % but less than 75 % [Withdrawn: replaced with ISO 22674] ISO 8909 Forage harvesters ISO 8909-1:1994 Part 1: Vocabulary ISO 8910:1993 Machinery and equipment for working the soil – Mouldboard plough working elements – Vocabulary ISO 8927:1991 Earth-moving machinery – Machine availability – Vocabulary ISO 8930:1987 General principles on reliability for structures – List of equivalent terms ISO 8936:2017 Awnings for leisure accommodation vehicles - Requirements and test methods ISO 8954 Ferroalloys - Vocabulary ISO 8954-1:1990 Part 1: Materials ISO 8954-2:1990 Part 2: Sampling and sample preparation ISO 8954-3:1990 Part 3: Sieve analysis ISO 8957:1996 Information and documentation - Hebrew alphabet coded character sets for bibliographic information interchange ISO 8965:2013 Logging industry – Technology – Terms and definitions ISO 8979:2004 Pliers and nippers for electronics - Nomenclature ISO 8980 Ophthalmic optics – Uncut finished spectacle lenses ISO 8980-1:2017 Part 1: Specifications for single-vision and multifocal lenses ISO 8980-2:2017 Part 2: Specifications for power-variation lenses ISO 8980-3:2013 Part 3: Transmittance specifications and test methods ISO 8980-4:2006 Part 4: Specifications and test methods for anti-reflective coatings ISO 8980-5:2005 Part 5: Minimum requirements for spectacle lens surfaces claimed to be abrasion-resistant ISO 8999:2001 Reciprocating internal combustion engines - Graphical symbols
== Feedback mechanisms == Signal transduction is a mechanism in which the cell responds to a signal from the environment by activating several proteins and enzymes that will give a response to the signal. Feedback mechanism might involve negative and positive feedbacks. In the negative feedback, the pathway is inhibited and the result of the transduction pathway is reduced or limited. In positive feedback, the transduction pathway is promoted and stimulated to produce more products.
An economical semisynthesis of progesterone from the plant steroid diosgenin isolated from yams was developed by Russell Marker in 1940 for the Parke-Davis pharmaceutical company. This synthesis is known as the Marker degradation.
Sources: en.wikipedia.org
=== 1954 === January 21: The U.S. launches the world's first nuclear submarine, the USS Nautilus. The nuclear submarine would become the ultimate nuclear deterrent. March 8: U.S. and Japan Mutual Defense Assistance Agreement is signed by the United States and Japan. March 13: The KGB is created as the successor agency of the NKVD. April–June: The Army–McCarthy hearings are broadcast on American television, leading to a loss of support for McCarthyism. May 7: The Viet Minh defeat the French at Dien Bien Phu. May 17: The Hukbalahap revolt in the Philippines is defeated. June 2: Senator Joseph McCarthy claims that communists have infiltrated the CIA and the atomic weapons industry. June 18: The elected leftist Guatemalan government is overthrown in a CIA-backed coup. An unstable rightist regime installs itself. Opposition leads to a guerrilla war with Marxist rebels in which major human rights abuses are committed on all sides. Nevertheless, the regime survives until the end of the Cold War. July 8: Col. Carlos Castillo Armas is elected president of the junta that overthrew the administration of Guatemalan President Jacobo Arbenz Guzman. July 21: The Geneva Conference concludes with accords ending French fighting in Indochina but does not resolve the conflict between the two internationally recognized Vietnamese regimes. The country is partitioned into communist North Vietnam and anticommunist South Vietnam, setting the stage for the Vietnam War. July 22: India annexes the Portuguese territories of Dadra and Nagar Haveli.
== Etymology == The word pepper derives from Old English pipor, Latin piper, and Greek πέπερι. The Greek likely derives from Sanskrit. In the 16th century, people began using pepper to also mean the New World chilli pepper (genus Capsicum), which is not closely related.
==== Donations to spouse's nonprofit organization ==== The Sacramento Bee reported that Jennifer Siebel Newsom's nonprofit organization The Representation Project had received more than $800,000 in donations from corporations that had lobbied the state government in recent years, including PG&E, AT&T, Comcast, and Kaiser Permanente. Siebel Newsom received $2.3 million in salary from the nonprofit since launching it in 2011. In 2021, Governor Newsom said that he saw no conflict in his wife's nonprofit accepting donations from companies that lobby his administration.
==== Cell cycle regulation ==== Cyclins are a group of proteins that activate kinases involved in cell division. The degradation of cyclins is the key step that governs the exit from mitosis and progress into the next cell cycle. Cyclins accumulate in the course the cell cycle, then abruptly disappear just before the anaphase of mitosis. The cyclins are removed via a ubiquitin-mediated proteolytic pathway.
== Works == Macleod was a prolific writer. His first academic article was a paper on phosphorus content in muscles published in 1899. During his career he authored or co-authored over 200 papers and eleven books. Among them are:
Sources: en.wikipedia.org
=== Gastrointestinal === Isotretinoin may cause non-specific gastrointestinal symptoms including nausea, diarrhea, and abdominal pain. The drug is associated with inflammatory bowel disease (IBD)—ulcerative colitis, but not Crohn's disease. There are also reports of people developing irritable bowel syndrome (IBS) and worsening of existing IBS.
=== Phylogenetic relationships and molecular studies === Modern taxonomy places X. parietina in the family Teloschistaceae, order Teloschistales, within the class Lecanoromycetes (lichenized Ascomycota). It is closely related to other orange lichens such as those in the genera Caloplaca, Teloschistes, and other members of the Xanthorioid clade of the Teloschistaceae. Molecular studies have helped clarify its phylogenetic relationships. For example, DNA sequence analyses provided evidence that X. parietina is genetically distinct from Xanthoria aureola, another yellow coastal lichen that had sometimes been considered merely a variety or form of X. parietina. Their study confirmed that X. aureola is a separate species, not conspecific with X. parietina. Microscopic studies have established Xanthoria parietina as the prototype species for the "Teloschistes-type" ascus, a structural category characterized by an apically thickened, strongly amyloid outer layer and a dome-like apex that splits longitudinally during spore release. This ascus type, originally described in members of Xanthoria, Teloschistes, and related genera, differs from the "Lecanora-type" by lacking a specialized discharge mechanism and instead relying on simple rupture for ascospore release. Early electron microscopy investigations of X. parietina helped clarify the functional nature of this ascus and its distinction from other ascus types found in lichenized fungi.
Bempedoic acid, sold under the brand name Nexletol among others, is a medication for the treatment of hypercholesterolemia (high blood cholesterol levels). The most common side effects include hyperuricemia (high blood levels of uric acid), pain in arms or legs, and anemia (low red blood cell counts). Bempedoic acid blocks an enzyme in the liver called adenosine triphosphate-citrate lyase, which is involved in making cholesterol. Bempedoic acid was approved for use in the United States in February 2020, and for use in the European Union in April 2020. The U.S. Food and Drug Administration considers it to be a first-in-class medication.
=== Remediation === Algae has shown selectivity for strontium in studies, where most plants used in bioremediation have not shown selectivity between calcium and strontium, often becoming saturated with calcium, which is greater in quantity and also present in nuclear waste. Researchers have looked at the bioaccumulation of strontium by Scenedesmus spinosus (algae) in simulated wastewater. The study claims a highly selective biosorption capacity for strontium of S. spinosus, suggesting that it may be appropriate for use of nuclear wastewater. A study of the pond alga Closterium moniliferum using stable strontium found that varying the ratio of barium to strontium in water improved strontium selectivity.
Sources: en.wikipedia.org
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.