For the fear of water, see Aquaphobia . Wiktionary Hydrophobia or hydrophobe may refer to Rabies , especially a set of symptoms of the later stages of an infection, in which the victim has difficulty swallowing, shows panic when presented with liquids to drink, and can not quench their thirst. Hydrophobe , a term used in chemistry to describe chemical aversions of a molecule, or part of a molecule, to water. Hydrophobia video game Hydrophobia video game Hydrophobia, a Hungarian List of disk magazines H disk magazine 1996 1997 disambig de Hydrophobie Begriffskl rung et H drofoobia es Hidrofobia fr Hydrophobie ... more details
Multiple issues primarysources December 2010 onesource December 2010 Protectosil is a silane manufactured by Evonik and marketed a protective coating for building surfaces. It is used as a Hydrophobe water repellent , and for corrosion and graffiti control. ref Cite web url http www.protectosil.com title Protectosil format work accessdate 2008 06 11 ref References Reflist Category Brand name materials Category Silanes Material stub ... more details
Magic sand , Moon Sand , Mars Sand , Space Sand , Sqand or Aqua Sand is a toy made from sand coated with a Hydrophobe hydrophobic compound. The presence of this hydrophobic compound causes the grains of sand to adhere to one another and form cylinder geometry cylinder s to minimize surface area when exposed to water. As soon as the sand is taken out of water, it is completely dry and flows freely. These properties are achieved by covering ordinary beach sand, which contains tiny particles of pure silica , and exposing them to vapors of trimethylsilanol Methyl CH sub 3 sup sub 3 sub Silicon Si Hydroxyl OH , an organosilicon compound. Upon exposure, the trimethylsilane compound bonds to the silica particles while forming water. The exteriors of the sand grains are thus coated with Hydrophobe hydrophobic groups. Magic sand was originally developed to trap ocean oil spill s near the shore. This would be done by sprinkling Magic sand on floating petroleum, which would then mix with the oil and make it heavy enough to sink. However, due to the expense of production, it is not being used for this purpose. It has also been tested by utility companies in the Arctic areas as a foundation for junction boxes, as it never freezes. It can be also used as an aerating medium for potted plants. Magic sand is made in blue, green, or red in colors but appears silvery in water because of a layer of air that forms around the sand. Earliest reference to waterproof sand can be found in a 1915 book called The Boy Mechanic Book 2 put out by Popular Mechanics. The Boy Mechanic states waterproof sand was invented by East Indian magicians. The sand was made by mixing heated sand with melted wax. The wax would repel the water when the sand was exposed to water. ref cite author G. Lee, Leonard Publisher title The Boy Mechanic Book 2, 1000 Things For A Boy To Do. Algrove Publishing Classic Reprint Series originally published in 1915. date 1999 ref References Reflist The magic sand can be changed in many ... more details
lowercase Fluids Home is a computer simulation of two phase flow behavior in microgravity and microfluidics ref cite web url http news.uns.purdue.edu html4ever 2004 040107.Ladisch.chip.html title Purdue engineers develop quick, inexpensive method to prototype microchips publisher News.uns.purdue.edu date 2004 01 07 accessdate 2011 02 20 ref problems at Purdue University , using the Surface Evolver program. About The project s purpose is to develop better methods for the management of liquid rocket propellant s in microgravity, ref cite web url http news.uns.purdue.edu x 2007b 070905CollicottSatellites.html title Engineers rescue aging satellites, saving millions publisher News.uns.purdue.edu date 2007 09 05 accessdate 2011 02 20 ref ref cite web url http news.uns.purdue.edu insidepurdue 2009 090716 ResearchCollicott.html title Research focuses on fuel injection in rockets publisher News.uns.purdue.edu date 2009 07 16 accessdate 2011 02 20 ref and to investigate two phase flow in microelectromechanical systems , taking into account factors like surface tension . Systems can then be designed that use electrowetting , channel geometry , and Hydrophobe hydrophobic or Hydrophile hydrophilic coating s to allow the smooth passage of fluids. Such systems would include compact medical device s, biosensor s, ref cite web url http news.uns.purdue.edu x 2009a 090421WereleyChips.html title Innovation could make lab on a chip devices easier to use, cheaper to make publisher News.uns.purdue.edu date 2009 04 21 accessdate 2011 02 20 ref and fuel cell s, to name a few. Computing platform It uses the Berkeley Open Infrastructure for Network Computing BOINC distributed computing platform. Application notes There is no screen saver. Work unit Central processing unit CPU times are generally less than 20 hours. Work units average in size around 500 Kilobyte kB . You have to run many work units to get levels of credit comparable to SETI Home or Climateprediction.net distributed programs. ... more details
refimprove date March 2010 Image Scheme facilitated diffusion in cell membrane en.svg thumb 300px right Facilitated diffusion in cell membrane, showing ion channel s and carrier proteins Not to be confused with diffusion . Facilitated diffusion is not a type of diffusion thermal motion but a type of transport process. Facilitated diffusion also known as facilitated transport or passive mediated transport is a process of passive transport as opposed to active transport , with this passive transport aided by integral membrane proteins. Facilitated diffusion is the spontaneous passage of molecules or ions across a biological membrane passing through specific transmembrane integral proteins. The facilitated diffusion may occur either across biological membrane s or through aqueous compartments of an organism. ref name isbn0 471 41759 9 cite book author Pratt, Charlotte Amerley Voet, Donald Voet, Judith G. title Fundamentals of biochemistry upgrade publisher Wiley location New York year 2002 pages 264 266 isbn 0 471 41759 9 oclc doi accessdate ref Polar molecules and charged ions are dissolved in water but they can not diffuse freely across the plasma membrane due to the hydrophobe hydrophobic nature of the fatty acid tails of phospholipid s that make up the lipid bilayer s. Only small nonpolar molecules, such as oxygen can diffuse easily across the membrane. All polar molecules are transported across cell membrane membranes by proteins that form transmembrane channels. These channels are gated so they can open and close, thus regulating the flow of ions or small polar molecules. Larger molecules are transported by transmembrane carrier proteins, such as permease s that change their conformation as the molecules are carried through, for example glucose or amino acids . Non polar molecules, such as retinol or fatty acid s are poorly soluble in water. They are transported through aqueous compartments of cells or through extracellular space by water soluble carriers as reti ... more details
Technical date August 2010 section Biomolecular structure Image Collagentriplehelix.png thumb right 79px Tropocollagen triple helix Scleroproteins , or fibrous proteins , constitute one of the three main classes of protein s, alongside globular protein s and conjugated proteins. Keratin , collagen , elastin , and fibroin ref name urlFibrous Protein Homepage cite web url http web.chemistry.gatech.edu williams bCourse Information 6521 protein fibrous fibrous.html title Fibrous Protein Homepage work accessdate 2008 11 26 ref are all scleroproteins. The roles of such proteins include protection and support, ref DorlandsDict seven 000095173 scleroprotein ref forming connective tissue , tendon s, Bone Matrix bone matrices , and muscle fiber . Biomolecular structure A scleroprotein forms long protein filament s, which are shaped like rods or wires. Scleroprotein are structural proteins or storage protein s that are typically inert and water Solubility insoluble . A scleroprotein occurs as an aggregate due to Hydrophobe hydrophobic side chain s that protrude from the molecule . A scleroprotein s peptide sequence often has limited Residue chemistry residues with repeats these can form unusual secondary structure s, such as a collagen helix . The structures often feature cross links between chains e.g., cys cys disulfide bond s between keratin chains . Scleroproteins tend not to Denaturation biochemistry denature as easily as globular protein s. Miroshnikov et al. 1998 are among the researchers who have attempted to synthesize fibrous proteins. ref name pmid9680195 Cite journal author Miroshnikov KA, Marusich EI, Cerritelli ME, et al. title Engineering trimeric fibrous proteins based on bacteriophage T4 adhesins journal Protein Eng. volume 11 issue 4 pages 329 32 year 1998 month April pmid 9680195 doi 10.1093 protein 11.4.329 url http peds.oxfordjournals.org cgi pmidlookup?view long&pmid 9680195 ref References Reflist External links MeshName Scleroproteins Protein topics Fibr ... more details
chembox verifiedrevid 399189869 ImageFile bmim.svg ImageSize IUPACName 1 butyl 3 methylimidazol 3 ium hexafluorophosphate OtherNames BMIM PF sub 6 sub Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 2015930 InChI 1 C8H15N2.F6P c1 3 4 5 10 7 6 9 2 8 10 1 7 2,3,4,5 6 h6 8H,3 5H2,1 2H3 q 1 1 SMILES1 CCCCn1cc n c1 C.F P F F F F F InChIKey IXQYBUDWDLYNMA UHFFFAOYAH StdInChI Ref stdinchicite correct chemspider StdInChI 1S C8H15N2.F6P c1 3 4 5 10 7 6 9 2 8 10 1 7 2,3,4,5 6 h6 8H,3 5H2,1 2H3 q 1 1 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey IXQYBUDWDLYNMA UHFFFAOYSA N CASNo 174501 64 5 PubChem 2734174 SMILES CCCCN1C C N C1 C.F P F F F F F Section2 Chembox Properties Formula C sub 8 sub H sub 15 sub F sub 6 sub N sub 2 sub P MolarMass 284.18228 Appearance Light Yellow, Liquid Density 1.38 g mL at 20 C MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition 1 Butyl 3 methylimidazolium hexafluorophosphate , also known as BMIM PF sub 6 sub , is a viscous, colourless, hydrophobe hydrophobic and non water soluble ionic liquid . Together with 1 butyl 3 methylimidazolium tetrafluoroborate, BMIM BF sub 4 sub , it is one of the most widely studied ionic liquids and is commercially available from most of the major international suppliers of chemicals. It is known to very slowly decompose in the presence of water. ref cite journal author R.P. Swatloski, J.D. Holbrey and R.D. Rogers title Ionic liquids are not always green hydrolysis of 1 butyl 3 methylimidazolium hexafluorophosphate journal Green Chem. year 2003 volume 5 pages 361 363 doi 10.1039 b304400a issue 4 ref Preparation BMIM PF sub 6 sub is commercially available. It may be obtained in two steps BMIM Cl is synthesized by alkylating 1 methylimidazole with 1 chlorobutane . A metathesis reaction with potassium hexafluorophosphate gives the desired compound the tetrafluoroborate may be prepared by analogously using potassium tetrafluorobo ... more details
A multiphasic liquid is a mixture consisting of more than two miscibility immiscible liquid Phase matter phases . Biphasic mixtures consisting of two immiscible phases are very common and usually consist of an organic compound organic solvent and an water molecule aqueous phase oil and water . Multiphasic liquids are rare and only triphasic three phases and tetraphasic four phases are known. Multiphasic liquids can be used for selective liquid liquid extraction s or for decorative purposes, e.g. in cosmetics . While it is possible to get multilayered phases by layering Nonpolarity nonpolar and aqueous phases of decreasing density densities on top of each other, these phases will not separate after mixing like true multiphasic liquids. Compositions The following types of multiphasic liquids exist Triphasic systems Nonpolar solvent aqueous biphasic mixture e.g. using hexane , heptane , cyclohexane , or mineral oil as the nonpolar solvent Nonpolar solvent Polar molecule polar solvent salt water e.g. 100 ml mineral oil, 100 ml isopropanol , 75 ml water molecule water , 35 g calcium chloride Nonpolar solvent water soluble polymer A, water soluble polymer B, water e.g. hexane, polyethylene oxide , dextran , water Nonpolar solvent water soluble polymer salt water e.g. hexane, polyethylene oxide, sodium sulfate , water Nonpolar solvent A solvent B polymer soluble in solvent B and water water e.g. heptane, dichloromethane , polyethylene oxide, water Nonpolar solvent A solvent B polymer soluble in solvent B and water salt water e.g. 16.3 heptane, 21.7 dichloromethane, 9.5 polyethylene oxide, 51.5 water, 0.1 sodium sulfate Nonpolar solvent hydrophobe hydrophobic salt water e.g. 2,2,4 Trimethylpentane iso octane , Aliquat 336 methyltrioctylammonium chloride, a phase transfer catalyst , water http venus.unive.it alvise index file page0003.htm or cyclohexane, 1 Butyl 3 methylimidazolium hexafluorophosphate bmim PF sub 6 sub an ionic liquid , water http www.mariecurie.org annals v ... more details
distinguish G protein Protein G is an immunoglobulin binding protein expressed in group C and G Streptococcal bacteria much like Protein A but with differing specificities. It is a 65 kDa G148 protein G and a 58 kDa C40 protein G ref name Sjobring 1991 cell surface protein that has found application in purifying antibodies through its binding to the Fc region. The native molecule also binds albumin, however, because serum albumin is a major contaminant of antibody sources, the albumin binding site has been removed from Recombinant DNA recombinant forms of Protein G. Other antibody binding proteins In addition to Protein G, other immunoglobulin binding bacterial proteins such as Protein A , Protein A G and Protein L are all commonly used to purify, immobilize or detect immunoglobulins. Each of these immunoglobulin binding proteins has a different antibody binding profile in terms of the portion of the antibody that is recognized and the species and type of antibodies it will bind. Folding of Protein G, B1 Domain An Ab initio quantum chemistry methods ab initio simulation of the protein G B1 domain demonstrates that, as earlier results suggested, this protein initiates folding via a nucleation event in the hydrophobe hydrophobic core Amino acid residues followed by small adjustments. ref name Kmiecik 1994 The folding events are as follows a Beta hairpin hairpin is formed, stabilized by residues W43, Y45, and F52. Residue contacts between residue F30, in an Alpha helix helix , and the hairpin strengthen. Nucleation of the Beta sheet sheet starting from residues L5 and F52, occurs. The last nucleation residue, Y3, assists in forming the central part of the sheet resulting in a globular protein . The protein G B1 domain is aka. GB1 often used as part of a fusion protein to keep other domains in solution during experiments in solution e.g. NMR . Many previously insoluble domains have become soluble with the fusion of the GB1 domain. ref name Cheng 2004 The domai ... more details
Membrane fouling is a process where solute or particles deposit onto a Artificial membrane membrane surface or into membrane pores in a way that degrades the membrane s performance. It is a major obstacle to the widespread use of this Membrane technology technology . Membrane fouling can cause severe flux decline and affect the quality of the water produced. Severe fouling may require intense chemical cleaning or membrane replacement. This increases the operating costs of a Sewage treatment treatment plant . There are various types of foulants colloid al clays, flocculation floc s , biological bacteria , fungi , organic oils , polyelectrolyte s, humic s and scaling mineral precipitates . ref Baker, R.W. 2004 . Membrane Technology and Applications, England John Wiley & Sons Ltd ref Fouling can be divided into reversible and irreversible fouling based on the attachment strength of particles to the membrane surface. Reversible fouling can be removed by a strong shear force of backwashing . Formation of a strong matrix of fouling layer with the solute during a continuous filtration process will result in reversible fouling being transformed into an irreversible fouling layer. Irreversible fouling is the strong attachment of particles which cannot be removed by physical cleaning. ref Choi, H., Zhang, K., Dionysiou, D.D.,Oerther, D.B.& Sorial, G.A. 2005 Effect of permeate flux and tangential flow on membrane fouling for wastewater treatment. J. Separation and Purification Technology 45 68 78. ref Factors affecting membrane fouling Factors that affect membrane fouling Membrane properties such as pore size, hydrophobe hydrophobicity , pore size distribution and membrane material. Solution properties such as concentration, the nature of the components and particle size distribution. Operating conditions such as pH , temperature , flow rate and pressure. Measure of membrane fouling Flux and transmembrane pressure TMP are the best indicators of membrane fouling. Under constant ... more details
The endodermis is the central, innermost layer of cortex in some land plants. It is made of compact living cells surrounded by an outer ring of endodermal cells that are impregnated with hydrophobe hydrophobic substances Casparian Strip to restrict apoplast ic flow of water to the inside. ref cite book last Rost first Thomas L. coauthors Michael Barbour, C. Ralph Stocking, Terence Murphy title Plant Biology, 2nd Edition publisher Thompson, Brooks Cole year 2006 isbn 0 534 38061 1 ref The endodermis is the boundary between the cortex and the Stele biology stele . In many seedless vascular plants, the endodermis is a distinctly visible layer of cells immediately outside the vascular cylinder stele in roots and shoots. In most seed plants, especially woody types, an endodermis is absent from the stems but is present in roots. The endodermis helps regulate the movement of water, ions and hormones into and out of the vascular system. It may also store starch, be involved in perception of gravity and protect the plant against toxins moving into the vascular system. Structure of the Endodermis The endodermis is developmentally the innermost portion of the cortex. It may consist of a single layer of barrel shaped cells without any intercellular spaces or sometimes several cell layers. The cells of the endodermis typically have their primary cell walls thickened on four sides radial and transverse with suberin , a water impermeable, waxy substance which in young endodermal cells is deposited in distinctive bands called Casparian strips . These strips vary in width but are typically smaller than the cell wall on which they are deposited. If the endodermis is likened to a brick cylinder e.g. a smokestack , with the bricks representing individual cells, the Casparian strips are analogous to the mortar between the bricks. In older endodermal cells, suberin may be more extensively deposited on all cell wall surfaces and the cells can become lignified, forming a complete waterproo ... more details
Image Jonofory.png thumb right 350 px Carrier Ionophores An ionophore is a lipid soluble molecule usually synthesized by microorganisms to transport ion s across the lipid bilayer of the cell membrane . There are two broad classifications of ionophores. Chemical compound s mobile ion carriers that bind to a particular ion, ref GoldBookRef title Ionophore file IT06772 ref shielding its charge from the surrounding environment, and thus facilitating its crossing of the Hydrophobe hydrophobic interior of the lipid membrane. Channel formers ref cite web url http www.ncbi.nlm.nih.gov sites entrez?Db mesh&Cmd ShowDetailView&TermToSearch 68007476&ordinalpos 1&itool EntrezSystem2.PEntrez.Mesh.Mesh ResultsPanel.Mesh RVDocSum title Ionophores MeSH Result format work accessdate ref that introduce a hydrophilic pore into the membrane, allowing ions to pass through while avoiding contact with the membrane s hydrophobic interior. Mechanism of action Ionophores disrupt transmembrane ion concentration gradients, required for the proper functioning and survival of microorganisms, and thus have antibiotic properties. They are produced naturally by a variety of microbes and act as a defense against competing microbes. Many antibiotics, particularly the macrolide antibiotics, are ionophores that exhibit high affinities for Na sup sup or K sup sup . ref name Green Greenwood&Earnshaw2nd ref The structure of the sodium and potassium complexes of antibiotics have been repeatedly verified by X ray crystallography. ref L. K. Steinrauf, J. A. Hamilton, M. N. Sabesan Crystal structure of valinomycin sodium picrate. Anion effects on valinomycin cation complexes J. Am. Chem. Soc. 1982, Volume 104, pp 4085 4091. DOI 10.1021 ja00379a008 ref In laboratory research, ionophores are used to increase the permeability of biological membranes to certain ions. Additionally, some ionophores are used as antibiotics and or as growth enhancing feed additives for certain feed animals such as cattle see monensin ... more details
refimprove date June 2008 Electrochemical gas sensors are gas detectors that measure the concentration of a target gas by Redox oxidizing or reducing the target gas at an electrode and measuring the resulting current. Construction The sensors contain two or three electrodes, occasionally four, in contact with an electrolyte . The electrodes are typically fabricated by fixing a high surface area precious metal on to the porous Hydrophobe hydrophobic membrane. The working electrode contacts both the electrolyte and the ambient air to be monitored usually via a porous membrane. The electrolyte most commonly used is a mineral acid , but organic electrolytes are also used for some sensors. The electrodes and housing are usually in a plastic housing which contains a gas entry hole for the gas and electrical contacts. Theory of operation The gas diffuses into the sensor, through the back of the porous membrane to the working electrode where it is oxidized or reduced. This Electrochemistry electrochemical reaction results in an electric current that passes through the external circuit. In addition to measuring, amplifying and performing other signal processing functions, the external circuit maintains the voltage across the sensor between the working and counter electrodes for a two electrode sensor or between the working and reference electrodes for a three electrode cell. At the counter electrode an equal and opposite reaction occurs, such that if the working electrode is an oxidation, then the counter electrode is a reduction. Diffusion controlled response The magnitude of the current is controlled by how much of the target gas is oxidized at the working electrode. Sensors are usually designed so that the gas supply is limited by diffusion and thus the output from the sensor is linear ly proportional to the gas concentration . This linear output is one of the advantages of electrochemical sensors over other sensor technologies, e.g. infrared , whose output must be linear ... more details
Refimprove date September 2011 File 1 palmitoyl 2 oleoyl glycerol.svg Chemical structure of the diglyceride 1 palmitoyl 2 oleoyl glycerol thumb right A diglyceride , or a diacylglycerol DAG , is a glyceride consisting of two fatty acid chains covalent bond covalently bonded to a glycerol molecule through ester linkages. One example, shown on the right, is 1 palmitoyl 2 oleoyl glycerol, which contains side chains derived from palmitic acid and oleic acid . Diacylglycerols can also have many different combinations of fatty acids attached at both the C 1 and C 2 positions. Food additive Mono and diacylglycerols are common food additives used to blend together certain ingredients, such as oil and water, which would not otherwise blend well. The commercial source may be either animal cow or hog derived or vegetable, derived primarily from partially hydrogenated soy bean and canola oil. Citation needed date February 2012 They may also be synthetically produced. They are often found in bakery products, beverages, ice cream, peanut butter, chewing gum, shortening , whipped toppings, margarine, and confections. Biological functions Protein kinase C activation Image PIP2 cleavage to IP3 and DAG.jpg thumb PIP2 cleavage to IP3 and DAG initiates intracellular calcium release and PKC activation. In biochemical signaling, diacylglycerol functions as a second messenger lipid signaling signaling lipid , and is a product of the hydrolysis of the phospholipid phosphatidylinositol 4,5 bisphosphate PIP2 by the enzyme phospholipase C PLC a cell membrane membrane bound enzyme that, through the same reaction, produces inositol trisphosphate IP sub 3 sub . Although inositol trisphosphate diffuses into the cytosol , diacylglycerol remains within the plasma membrane , due to its hydrophobe hydrophobic properties. IP sub 3 sub stimulates the release of calcium ions from the smooth endoplasmic reticulum, whereas DAG is a physiological activator of protein kinase C PKC . The production of DAG in ... more details
Image Lipid A.png thumb 250px Chemical structure of lipid A as found in E. Coli ref name Raetz2009 cite journal author Raetz, Christian R. H. Guan, Ziqiang Ingram, Brian O. Six, David A. Song, Feng Wang, Xiaoyuan Zhao, Jinshi title Discovery of new biosynthetic pathways the lipid A story journal Journal of Lipid Research year 2009 pages S103 S108 ref Lipid A is a lipid component of an endotoxin held responsible for toxicity of Gram negative bacteria . It is the innermost of the three regions of the lipopolysaccharide LPS, also called endotoxin molecule, and its hydrophobe hydrophobic nature allows it to anchor the LPS to the outer membrane. ref name Raetz cite journal author Raetz C, Whitfield C title Lipopolysaccharide endotoxins journal Annu Rev Biochem volume 71 issue 1 pages 635 700 year 2002 pmid 12045108 url http arjournals.annualreviews.org doi abs 10.1146 2Fannurev.biochem.71.110601.135414?cookieSet 1 doi 10.1146 annurev.biochem.71.110601.135414 format abstract pmc 2569852 ref While its toxic effects can be damaging, the sensing of lipid A by the human immune system may also be critical for the onset of immune responses to Gram negative infection, and for the subsequent successful fight against the infection. ref name pmid11948150 cite journal author Tzeng YL, Datta A, Kolli VK, Carlson RW, Stephens DS title Endotoxin of Neisseria meningitidis composed only of intact lipid A inactivation of the meningococcal 3 deoxy D manno octulosonic acid transferase journal J. Bacteriol. volume 184 issue 9 pages 2379 88 year 2002 month May pmid 11948150 pmc 134985 doi 10.1128 JB.184.9.2379 2388.2002 url http jb.asm.org cgi pmidlookup?view long&pmid 11948150 ref Functions Many of the immune activating abilities of LPS can be attributed to the lipid A unit. It is a very potent stimulant of the immune system , activating cells for example, monocyte s or macrophage s at picogram per milliliter quantities. When present in the body at high concentrations during a Gram negative ... more details
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