Mycolic acids are long fatty acid s found in the cell wall s of the Mycobacterium mycolata taxon , a group of bacteria that includes Mycobacterium tuberculosis , the causative agent of the disease tuberculosis . They form the major component of the cell wall of mycolata species. Despite their name, mycolic acids have no biological link to fungus fungi the name arises from the filamentous appearance their presence gives mycolata under high magnification. The presence of mycolic acids in the cell wall also gives mycolata a distinct gross morphological trait known as cording. Mycolic acids were first isolated by Stodola et al. in 1938 from an extract of M. tuberculosis . Mycolic acids are composed of a shorter Beta hydroxy acid beta hydroxy chain with a longer alpha alkyl side chain . Each molecule contains between 60 and 90 carbon atoms. The exact number of carbons varies by species and can be used as an identification aid. Most mycolic acids also contain various functional group s. Mycolic Acids of M. tuberculosis File Mycobacterium mycolic acids.svg thumb 500px Mycolic acids in Mycobacterium tuberculosis. M. tuberculosis produces three main types of mycolic acids alpha , methoxy , and keto . Alpha mycolic acids comprise at least 70 of the mycolic acids present in the organism and contain several cyclopropane rings. Methoxy mycolic acids, which contain several methoxy groups, comprise between 10 and 15 of the mycolic acids in the organism. The remaining 10 to 15 of the mycolic acids are keto mycolic acids, which contain several ketone groups. The presence of mycolic acids gives M. tuberculosis many characteristics that defy medical treatment. They lend the organism increased resistance to chemical damage and dehydration, and prevent the effective activity of hydrophobe hydrophobic antibiotic s. In addition, the mycolic acids allow the bacterium to grow readily inside macrophage s, effectively hiding it from the host s immune system . Mycolate biosynthesis is crucial ... more details
Infobox protein family Symbol Hydrophobin Name Hydrophobin image width caption Pfam PF01185 Pfam clan InterPro IPR001338 SMART PROSITE PDOC00739 MEROPS SCOP 1r2m TCDB OPM family OPM protein CAZy CDD Pfam box Symbol Hydrophobin 2 Name Fungal hydrophobin image Hydrophobin.png width 250 caption Structure of hydrophobin HFBI from Trichoderma reesei Pfam PF06766 InterPro IPR010636 SMART PROSITE PDOC00739 SCOP 1r2m TCDB OPM family OPM protein 1r2m PDB PDB3 1r2m B 17 82 Hydrophobins are a group of small, cysteine rich proteins 100 amino acids that are expressed only by Mold filamentous fungi . They are known for their ability to form a Hydrophobe hydrophobic water repellent coating on the surface of an object. ref name pmid17875392 cite journal author Sunde M, Kwan AH, Templeton MD, Beever RE, Mackay JP title Structural analysis of hydrophobins journal Micron volume 39 issue 7 pages 773 84 year 2008 month October pmid 17875392 doi 10.1016 j.micron.2007.08.003 ref They were first discovered and separated in Schizophyllum commune in 1991. ref name pmid12324614 cite journal author Wessels J, De Vries O, Asgeirsdottir SA, Schuren F title Hydrophobin Genes Involved in Formation of Aerial Hyphae and Fruit Bodies in Schizophyllum. journal Plant Cell year 1991 volume 3 issue 8 pages 793 799 pmid 12324614 doi 10.1105 tpc.3.8.793 pmc PMC160046 url http www.ncbi.nlm.nih.gov entrez eutils elink.fcgi?dbfrom pubmed&tool sumsearch.org cite&retmode ref&cmd prlinks&id 12324614 ref Based on differences in hydropathy patterns and biophysics biophysical properties, they can be divided into two categories class I and class II. Hydrophobins can self assemble into a monolayer on hydrophobic hydrophilic interfaces such as an water air interface. Class I monolayer contains the same core structure as amyloid fibrils, and is positive to Congo red and thioflavin T. The monolayer formed by class I hydrophobins has a highly ordered structure, and can only be dissociated by concentrated trifluoroacetate ... more details
Poloxamers are nonionic triblock copolymers composed of a central hydrophobic chain of polypropylene glycol polyoxypropylene poly propylene oxide flanked by two hydrophilic chains of polyethylene glycol polyoxyethylene poly ethylene oxide . The word poloxamer was coined by the inventor, Irving Schmolka, who received the patent for these materials in 1973. ref cite patent US 3740421 ref Poloxamers are also known by the trade name Pluronics . ref cite web url http worldaccount.basf.com wa NAFTA en US Catalog ChemicalsNAFTA pi BASF Brand pluronic title BASF Product information the chemicals catalog Pluronics work BASF Corporation Website accessdate 2008 12 09 ref Because the lengths of the polymer blocks can be customized, many different poloxamers exist that have slightly different properties. For the generic term poloxamer , these copolymers are commonly named with the letter P for poloxamer followed by three digits, the first two digits x 100 give the approximate molecular mass of the polyoxypropylene core, and the last digit x 10 gives the percentage polyoxyethylene content e.g., Poloxamer 407 P407 Poloxamer with a polyoxypropylene molecular mass of 4,000 g mol and a 70 polyoxyethylene content . For the Pluronic tradename, coding of these copolymers starts with a letter to define its physical form at room temperature L liquid, P paste, F flake solid followed by two or three digits, The first digit two digits in a three digit number in the numerical designation, multiplied by 300, indicates the approximate molecular weight of the hydrophobe and the last digit x 10 gives the percentage polyoxyethylene content e.g., L61 Pluronic with a polyoxypropylene molecular mass of 1,800 g mol and a 10 polyoxyethylene content . In the example given, poloxamer 181 P181 Pluronic L61. Uses of poloxamers Because of their amphiphilic structure, the polymers have surfactant properties that make them useful in industrial applications. Among other things, they can be used to increase the ... more details
enzyme Name chymotrypsin EC number 3.4.21.1 CAS number 9004 07 3 IUBMB EC number 3 4 21 1 GO code 0004263 image ChymotrypsinA1.jpg width caption Crystallographic structure of Bos taurus chymotrypsinogen. ref name pmid5442169 PDB 1CHG cite journal author Freer ST, Kraut J, Robertus JD, Wright HT, Xuong NH title Chymotrypsinogen 2.5 angstrom crystal structure, comparison with alpha chymotrypsin, and implications for zymogen activation journal Biochemistry volume 9 issue 9 pages 1997 2009 year 1970 month April pmid 5442169 doi 10.1021 bi00811a022 url ref enzyme Name chymotrypsin C EC number 3.4.21.2 CAS number 9036 09 3 IUBMB EC number 3 4 21 2 GO code image width caption Chymotrypsin is a digestive enzyme that can perform proteolysis . ref name Wilcox 1970 cite journal author Wilcox PE year 1970 title Chymotrypsinogens chymotrypsins journal Methods in Enzymology volume 19 pages 64 108 doi 10.1016 0076 6879 70 19007 0 series Methods in Enzymology isbn 978 0 12 181881 4 ref Chymotrypsin preferentially cleaves peptide amide bonds where the carboxyl side of the amide bond the P sub 1 sub position is a tyrosine , tryptophan , or phenylalanine . These amino acid s contain an aromatic ring in their substituent sidechain that fits into a hydrophobe hydrophobic pocket the S sub 1 sub position of the enzyme. The hydrophobic and shape complementarity between the peptide enzyme substrate substrate P sub 1 sub sidechain and the enzyme S sub 1 sub binding cavity accounts for the substrate specificity of this enzyme. ref name pmid3555886 cite journal author Appel W title Chymotrypsin molecular and catalytic properties journal Clin. Biochem. volume 19 issue 6 pages 317 22 year 1986 month December pmid 3555886 doi 10.1016 S0009 9120 86 80002 9 url ref ref name pmid4399049 cite journal author Berger A, Schechter I title Mapping the active site of papain with the aid of peptide substrates and inhibitors journal Philos. Trans. R. Soc. Lond., B, Biol. Sci. volume 257 issue 813 pages 249 6 ... more details
Micellar electrokinetic chromatography MEKC , is a chromatography technique, used in analytical chemistry . It is a modification of capillary electrophoresis CE , where the samples are separated by differential partitioning between micelles pseudo stationary phase and a surrounding aqueous buffer solution mobile phase . ref Terabe, S. Otsuka, K. Ichikawa, K. Tsuchiya, A. Ando, T. Anal. Chem . 1984 , 56 , 111. ref The basic set up and detection methods used for MEKC are the same as those used in CE. The difference is that the solution contains a surfactant at a concentration that is greater than the critical micelle concentration CMC . Above this concentration, surfactant monomers are in chemical equilibrium equilibrium with micelles. In most applications, MEKC is performed in open capillaries under alkaline conditions to generate a strong electro osmosis electroosmotic flow . Sodium dodecyl sulfate SDS is the most commonly used surfactant in MEKC applications. The anionic character of the sulfate groups of SDS cause the surfactant and micelles to have electrophoresis electrophoretic mobility that is counter to the direction of the strong electroosmotic flow . As a result, the surfactant monomers and micelles migrate quite slowly, though their net movement is still toward the cathode . ref Baker, D.R. Capillary Electrophoresis John Wiley & Sons, Inc. New York, 1995 . ref During a MEKC separation, analyte s distribute themselves between the hydrophobe hydrophobic interior of the micelle and hydrophile hydrophilic buffer solution as shown in figure 1 . Image MEKC.gif frame Figure 1 Depiction of the distribution of analytes A based on their hydrophobicity. Analytes that are soluble insoluble in the interior of micelles should migrate at the electroosmotic flow velocity, math u o math , and be detected at the retention time of the buffer, math t M math . Analytes that solubilize completely within the micelles analytes that are highly hydrophobic should migrate at the mic ... more details
File Fluranebottles.jpg thumb Bottles of sevoflurane , isoflurane , enflurane , and desflurane , the common fluorinated ether anaesthetics used in clinical practice. These agents are colour coded for safety purposes. Note the special fitting for desflurane, which Boiling point boils at Standard conditions for temperature and pressure room temperature . An inhalational anaesthetic is a chemical compound possessing general anaesthetic properties that can be delivered via inhalation. They are administered by anaesthetists a term which includes anesthesiologist anaesthesiologist s, nurse anesthetist nurse anaesthetist s, and Anesthesia Anesthesiologist assistants anaesthesiologist assistants through an anaesthesia mask, laryngeal mask airway or tracheal tube connected to some type of anaesthetic vaporiser and an anaesthetic machine anaesthetic delivery system . Agents of significant contemporary clinical interest include Volatility chemistry volatile anaesthetic agents such as isoflurane , sevoflurane and desflurane , as well as certain anaesthetic gases such as nitrous oxide and xenon . List of inhalational anaesthetic agents Currently used agents isoflurane desflurane nitrous oxide sevoflurane Previously used agents Although some of these are still used in clinical practice and in research, the following anaesthetic agents are primarily of historical interest in Developed country developed countries aliflurane chloroform cyclopropane diethyl ether enflurane ethylene halothane methoxyflurane methoxypropane roflurane teflurane trichloroethylene vinyl ether Future agents xenon Volatile anaesthetics Volatile anaesthetic agents share the property of being liquid at room temperature, but evaporating easily for administration by inhalation. All of these agents share the property of being quite Hydrophobe hydrophobic i.e., as liquids, they are not freely Miscibility miscible with water, and as gases they dissolve in oils better than in water . The ideal volatile anaesthetic a ... more details
Microemulsions are clear, thermodynamically stable, isotropic liquid mixtures of oil, water and surfactant , frequently in combination with a cosurfactant . The aqueous Phase matter phase may contain salt s and or other ingredients, and the oil may actually be a complex mixture of different hydrocarbon s and olefins . In contrast to ordinary emulsion s, microemulsions form upon simple mixing of the components and do not require the high Shear fluid shear conditions generally used in the formation of ordinary emulsions. The three basic types of microemulsions are direct oil dispersed in water, o w , reversed water dispersed in oil, w o and bicontinuous. In ternary systems such as microemulsions, where two immiscible phases water and oil are present with a surfactant, the surfactant molecule s may form a monolayer at the interface between the oil and water, with the hydrophobe hydrophobic tails of the surfactant molecules dissolved in the oil phase and the hydrophilic head groups in the aqueous phase. Uses Microemulsions have many commercially important uses Water in oil microemulsions for some dry cleaning processes Floor polishing polishers and Cleanliness cleaners Personal care products Pesticide formulations Cutting oil s. Much of the work done on these systems have been motivated by their possible use to mobilize petroleum trapped in porous sandstone for enhanced oil recovery A fundamental reason for the uses of these systems is that a microemulsion phase sometimes has an ultralow interfacial tension with a separate oil or aqueous phase, which may release or mobilize them from solid phases even in conditions of slow flow or low pressure gradients. Microemulsions also have industrial applications, one of them being the synthesis of polymer s. Microemulsion polymerization is a complex heterogeneous process where transport of monomers, free radicals and other species such as chain transfer agent, co surfactant and inhibitors between the aqueous and organic phases, t ... more details
Cleanup date September 2007 infobox enzyme Name Non specific serine threonine protein kinase EC number 2.7.11.1 CAS number 9026 43 1 IUBMB EC number 2 7 11 1 GO code 0004682 image Protein AURKA PDB 1mq4.png width caption Human Aurora Kinase Protein Data Bank PDB PDBe 1mq4 ref cite pmid 12467573 ref Image L serine skeletal.png thumb serine Image L threonine skeletal.png thumb threonine Image Phosphate Group.PNG right thumb phosphate A serine threonine protein kinase EC number 2.7.11.1 is a kinase enzyme that phosphorylates the OH group of serine or threonine which have similar sidechains . At least 125 of the 500 human protein kinases are serine threonine kinases STK . ref name Capra Regulation Serine Threonine Kinase receptors plays a role in the regulation of cell proliferation, programmed cell death apoptosis , cell differentiation, and embryonic development. Selectivity While serine threonine kinases all phosphorylate serine or threonine residues in their substrates, they select specific residues to phosphorylate on the basis of residues that flank the phosphoacceptor site, which together comprise the consensus sequence . Since the consensus sequence residues of the substrate to be phosphorylated make contact with the catalytic cleft of the kinase at several key amino acids usually through hydrophobe hydrophobic forces and ionic bond s , a kinase is usually not specific to a single substrate, but instead can phosphorylate a whole substrate family having common recognition sequences. While the catalytic domain of these kinases is Conserved sequence highly conserved , the sequence variation that is observed in the kinome the subset of genes in the genome that encode kinases provides for recognition of distinct substrates. Most kinases are inhibited by a pseudosubstrate that binds to the kinase like a real substrate but lacks the amino acid to be phosphorylated. When the pseudosubstrate is removed, the kinase can perform its normal function. EC numbers Many serine t ... more details
Refimprove date March 2010 Injection molding of liquid silicone rubber LSR is a process to produce pliable, durable parts in high volume. Liquid silicone rubber is a high purity platinum cured silicone with low compression set, great stability and ability to resist extreme temperatures of heat and cold ideally suitable for production of parts, where high quality is a must. Due to the Thermosetting polymer thermosetting nature of the material, liquid silicone injection molding requires special treatment, such as intensive distributive mixing, while maintaining the material at a low temperature before it is pushed into the heated cavity and Vulcanization vulcanized . Chemically, silicone rubber is a family of Thermoplastic elastomer thermoset elastomers that have a backbone of alternating silicon and oxygen atoms and methyl or vinyl side groups. Silicone rubbers constitute about 30 of the silicone family, making them the largest group of that family. Silicone rubbers maintain their mechanical properties over a wide range of temperatures and the presence of methyl groups in silicone rubbers makes these materials extremely Hydrophobe hydrophobic . Typical applications for liquid silicone rubber are products that require high precision such as seals, sealing membranes, electric connectors, multi pin connectors, infant products where smooth surfaces are desired, such as bottle nipples, medical applications as well as kitchen goods such as baking pans, spatulas, etc. Often, silicone rubber is overmolded onto other parts made of different plastics. For example, a silicone button face might be overmolded onto an Nylon Nylon 6,6 housing. Equipment In order for the liquid injection molding process to fully occur, several mechanical components must be in place. Typically, a molding machine requires a metered pumping device in conjunction with an injection unit a dynamic or static mixer is attached. An integrated system can aid in precision and process efficiency. The critical c ... more details
File Alkylsulfate.png thumb 200 px Structure of an alkylsulfate not show is the cation such as sodium or ammonium . Organosulfates are a class of organic compounds sharing a common functional group commonly with the structure R O SO sub 3 sub sup sup . The SO sub 4 sub core is a sulfate group and the R group is any organic residue. All organosulfates are formally ester s derived from alcohol s and sulfuric acid , although many are not prepared in this way. Many sulfate esters are used in detergents, and some are useful reagent s. Alkyl sulfates consist of a hydrophobe hydrophobic hydrocarbon chain, a polar sulfate or sulfonate group containing an anion and either a cation or amine to neutralize the sulfate group. Examples include sodium lauryl sulfate also known as sulfuric acid mono dodecyl ester sodium salt and related potassium and ammonium salts. Applications Alkyl sulfates are commonly used as an anionic surfactant in liquid soaps, detergents to clean wool, surface cleaners, as active ingredients in laundry detergents, shampoos and conditioners. They can also be found in other household products such as toothpastes, antacids, cosmetics and foods. Generally they are found in consumer products at concentrations ranging from 3 20 . In 2003 approximately 118,000 t a of alkyl sulfates were used in the U.S. ref cite web last CEH title Surfactants, household detergents and their raw materials work CEH Marketing Research Report month October year 2004 ref Synthetic organosulfates A common example is sodium lauryl sulfate , with the formula CH sub 3 sub CH sub 2 sub sub 11 sub OSO sub 3 sub Na. Also common in consumer products are the sulfate esters of ethoxylation ethoxylated fatty alcohols such as those derived from lauryl alcohol . An example is sodium laureth sulfate , an ingredient in some cosmetics . ref Eduard Smulders, Wolfgang von Rybinski, Eric Sung, Wilfried R hse, Josef Steber, Frederike Wiebel, Anette Nordskog Laundry Detergents in Ullmann s Encyclopedia of ... more details
, a form of social anxiety disorder social phobia . Aquaphobia fear of water . Distinct from Hydrophobe .... Hydrophobe Hydrophobia Hydrophobic a property of being repelled by water. Lipophobicity a property ... more details
About topical medications Topic disambiguation Refimprove date December 2008 In medicine , a topical medication is applied to body surface area body surfaces such as the human skin skin or mucous membrane s to treat ailments via a large range of classes including but not limited to creams , foams , gels , lotions and ointments . ref group University of Maryland cite web title Psoriasis Treatment url http www.umm.edu patiented articles what topical therapies psoriasis 000087 7.htm work Medical Reference publisher University of Maryland Medical System year 2009 ref Topical medications differ from many other types of drugs because mishandling them can lead to certain complications in a patient or administrator of the drug. ref cite journal last Zaghi first D coauthors Maibach title Survey of Safety and efficacy information in drug inserts for topical prescription medications journal American Journal of Clinical Dermatology year 2007 volume 8 issue 1 pages 43 46 accessdate 2 May 2012 ref Many topical medications are epicutaneous , meaning that they are applied directly to the skin. Topical medications may also be inhalational , such as asthma medication s, or applied to the surface of tissues other than the skin, such as eye drops applied to the conjunctiva , or ear drop s placed in the ear, or medications applied to the surface of a tooth . As a route of administration , topical medications are contrasted with enteral administration enteral in the digestive tract and parenteral administration injected into the circulatory system . A topical effect , in the pharmacodynamic sense, may refer to a local, rather than systemic effect systemic , target for a medication. However, many topically administered drugs have systemic effects. Some hydrophobe hydrophobic chemicals, such as steroid hormone s, can be absorption skin absorbed into the body after being applied to the skin in the form of a cream pharmaceutical cream , gel or lotion . Transdermal patch es have become a popu ... more details
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