bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recruitment of β-Catenin by Wild-Type or Mutant Androgen Receptors Correlates with Ligand-Stimulated Growth of Prostate Cancer Cells
Authors: Masiello David , Chen Shao-Yong , Xu Youyuan , Verhoeven Manon C. , Choi Eunis , Hollenberg Anthony N. , Balk Steven P. 
Published: July 2004

AbstractProstate cancers respond to treatments that suppress androgen receptor (AR) function, with bicalutamide, flutamide, and cyproterone acetate (CPA) being AR antagonists in clinical use. As CPA has substantial agonist activity, it was examined to identify AR coactivator/corepressor interactions that may mediate androgen-stimulated prostate cancer growth. The CPA-liganded AR was coactivated by steroid receptor coactivator-1 (SRC-1) but did not mediate N-C terminal interactions or recruit β-catenin, indicating a nonagonist conformation. Nonetheless, CPA did not enhance AR interaction with nuclear receptor corepressor, whereas the AR antagonist RU486 (mifepristone) strongly stimulated AR-nuclear receptor corepressor binding. The role of coactivators was further assessed with a T877A AR mutation, found in LNCaP prostate cancer cells, which converts hydroxyflutamide (HF, the active flutamide metabolite) into an agonist that stimulates LNCaP cell growth. The HF and CPA-liganded T877A ARs were coactivated by SRC-1, but only the HF-liganded T877A AR was coactivated by β-catenin. L-39, a novel AR antagonist that transcriptionally activates the T877A AR, but still inhibits LNCaP growth, similarly mediated recruitment of SRC-1 and not β-catenin. In contrast, β-catenin coactivated a bicalutamide-responsive mutant AR (W741C) isolated from a bicalutamide-stimulated LNCaP subline, further implicating β-catenin recruitment in AR-stimulated growth. Androgen-stimulated prostate-specific antigen gene expression in LNCaP cells could be modulated by β-catenin, and endogenous c-myc expression was repressed by dihydrotestosterone, but not CPA. These results indicate that interactions between AR and β-catenin contribute to prostate cell growth in vivo, although specific growth promoting genes positively regulated by AR recruitment of β-catenin remain to be identified.
Adsorption and Reaction of Methanol on Clean and Oxygen Precovered Cu(111)
Authors: Pöllmann S. , Bayer A. , Ammon Ch. , Steinrück Hans-Peter 
Published: July 2004

Abstract
The adsorption of methanol on the clean and oxygen precovered Cu(111) surface was studied by means of high resolution X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and temperature programmed desorption (TPD). On clean Cu(111) methanol is adsorbed molecularly at 100 K. Only small amounts of methoxy are formed by heating to 160–180 K, whereas the main part of methanol desorbs molecularly. The formation of methoxy drastically increases on the oxygen precovered surface. In the UP spectra the peaks of molecular methanol disappear and the peaks of methoxy develop. TPD measurements show that methoxy desorbs dissociatively as formaldehyde and hydrogen with the rate maxima at around 430 K. The efficiency of the oxidation of methanol to formaldehyde depends on the amount of predosed oxygen, with a maximum methoxy coverage obtained for an oxygen precoverage of 0.18 ML. From the quantitative analysis we propose an additional reaction pathway involving not only the formation, but also the decomposition of an hydroxyl intermediate, parallel to the previously reported pathway, which leads to the desorption of water.
Hydrogen-Induced and Defect-Mediated Structural Transition (5×1)-hex → (5×1)-H on Ir(100)
Authors: Heinz Klaus , Hammer Lutz 
Published: July 2004

Abstract
Ir(100) is well known to exhibit a (5×1) periodic surface reconstruction denoted as (5×1)-hex. The atoms of the outermost layer are quasi-hexagonally arranged rather than being of quadratic order as the layers below and in the bulk. Accordingly, an excess of 20% of atoms is accommodated in the top layer and the surface is buckled with atomic rows protruding from the surface. It is shown by the combined application of atomically resolved scanning tunnelling microscopy (STM) and quantitative low-energy electron diffraction (LEED) that hydrogen adsorption at sufficiently high temperature induces the surface to restructure. The new phase, (5×1)-H, develops by the extraction of surface protruding and close packed atomic Ir wires from the hexagonal layer. The remaining atoms of the latter reassume quadratic order and the wires expelled reside on this layer. The extraction of the Ir wires proceeds in a zip-like process and starts preferentially at surface defects, in particular at step edges or domain boundaries. The wires’ lateral periodicity normal to their spatial orientation is again 5-fold, but only on average. The precise lateral arrangement depends sensitively on the details of preparation, in particular the amount of hydrogen exposure and the sample’s temperature during, or temperature treatment after, exposure.
Absorption
Authors: Laso Manuel , von Stockar Urs 
Published: July 2004

AbstractAbsorption, or gas absorption, is a unit operation used in the chemical industry to separate gases by washing or scrubbing a gas mixture with a suitable liquid. One or more of the constituents of the gas mixture dissolves or is absorbed in the liquid and can thus be removed from the mixture. In some systems, this gaseous constituent forms a physical solution with the liquid or the solvent, and in other cases, it reacts with the liquid chemically. The purpose of such scrubbing operations may be gas purification, eg, removal of air pollutants from exhaust gases; product recovery; or production of solutions of gases for various purposes. Gas absorption is usually carried out in vertical countercurrent columns. The solvent is fed in at the top of the absorber, the gas mixture from the bottom. The absorbed substance is washed out by the solvent, which is often recovered in a subsequentstrippingor desorption operation. The absorber may be a packed column, plate tower, or simple spray column, or a bubble column. The fundamental physical principles underlying the process of gas absorption are the solubility of the absorbed gas and the rate of mass transfer. Information on both must be available when sizing equipment for a given application. In standard packed absorption columns, a gas mixture travels up through a gas absorption tower and the solute is transferred to the liquid phase and thus gradually removed from the gas. The liquid accumulates solute on its way down through the column. Multicomponent mass‐transfer effects, nonisothermal gas absorption, and axial dispersion effects result in considerable departures from ideal flow assumptions. Neglect of axial dispersion results in an overestimation of the driving forces and may lead to an unsafe design. Bubble tray absorption columns may be designed graphically based on a so‐called McCabe‐Thiele diagram. The required number of actual plates, however, is larger than the number of theoretical plates. The computation of nonisothermal gas absorption processes is difficult because of all the interactions involved. A computer is normally required to establish the correct concentration and temperature profiles through the tower.
Acetaldehyde
Authors: Hagemeyer H. J. 
Published: July 2004

AbstractAcetaldehyde is a product of most hydrocarbon oxidations. It occurs in trace amounts in all ripe fruits that have a tart taste before ripening. Acetaldehyde is also an intermediate product of fermentation. It may form in wine and other alcoholic beverages after exposure to air, imparting an unpleasant taste. Acetaldehyde occurs in trace quantities in blood. Acetaldehyde is a colorless, mobile liquid having a pungent, suffocating odor that is somewhat fruity and quite pleasant in dilute concentrations. It is a highly reactive compound undergoing numerous condensation, addition, and polymerization reactions. The liquid‐phase oxidation of ethylene is the process of choice for the manufacture of acetaldehyde. Acetaldehyde appears to paralyze respiratory muscles, causing panic. When breathed in high concentration, it causes headache and sore throat. Demand for acetaldehyde has decreased as a result of less consumption for acetic acid manufacture.
Acetylene‐Derived Chemicals
Authors: Hort Eugene V. , Taylor Paul 
Published: July 2004

AbstractAcetylene, C2H2, is an extremely reactive hydrocarbon, principally used as a chemical intermediate. Because of its relatively high price, there have been continuing successful efforts to replace acetylene with cheaper raw materials. The name ethynylation was coined by Reppe to describe the addition of acetylene to carbonyl compounds. Principal Reppe acetylene chemicals include propargyl alcohol, butynediol, butenediol, butanediol, and butyrolactone. Butynediol is principally consumed in manufacture of butenediol and butanediol. Butanediol is consumed in manufacture of butyrolactone and tetrahydrofuran. Large amounts are also used as a monomer for polyesters and polyurethanes. Butyrolactone is principally used as an intermediate for manufacture of pyrrolidones. Propargyl alcohol is a primary skin irritant and severe eye irritant, highly toxic by all means of ingestion. Catalytic vinylation, in which a labile hydrogen compound adds to acetylene, forming a double bond, has been applied to a wide range of alcohols, phenols, thiols, and carboxylic acids. Vinyl ethers are used in the manufacture of glutaraldehyde and as monomers.
Acetone
Authors: Howard William L. 
Published: July 2004

AbstractAcetone [67‐64‐1] (2‐propanone, dimethyl ketone, CH3COCH3), molecular weight 58.08 (C3H6O), is the simplest and most important of the ketones. It is a colorless, mobile, flammable liquid with a mildly pungent, somewhat aromatic odor, and is miscible in all proportions with water and most organic solvents. Acetone is an excellent solvent for a wide range of gums, waxes, resins, fats, greases, oils, dyestuffs, and cellulosics. It is used as a carrier for acetylene, in the manufacture of a variety of coatings and plastics, and as a raw material for the chemical synthesis of a wide range of products such as ketene, methyl methacrylate, bisphenol A, diacetone alcohol, methyl isobutyl ketone, hexylene glycol (2‐methyl‐2,4‐pentanediol), and isophorone. World production of acetone in 1999 was about 4.27 million metric tons per year, of which ∼1.4 million was made in the United States. Most of the world's manufactured acetone is obtained as a coproduct in the process for phenol from cumene and most of the remainder from the dehydrogenation of isopropyl alcohol. Numerous natural sources of acetone make it a normal constituent of the environment. It is readily biodegradable.
Acetal Resins
Authors: Starr John B. 
Published: July 2004

Abstract

The term “acetal resins” commonly denotes the family of homopolymers and copolymers whose main chains are completely or essentially composed of repeating oxymethylene units

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. The polymers are derived chiefly from formaldehyde or methanal, either directly or through its cyclic trimer, trioxane or 1,3,5‐trioxacyclohexane. The many commercially attractive properties of acetal resins are due in large part to the inherent high crystallinity of the base polymers, which contributes significantly to their excellent resistance to most chemicals, including many organic solvents. Stiffness, creep resistance, fatigue resistance, and excellent lubricity are properties of acetal resins which have contributed significantly to their commercial success. Acetal resins are generally stable in mildly alkaline environments. Properly end‐capped acetal resins are relatively thermally stable. Formaldehyde polymerizes by both anionic and cationic mechanisms. Copolymerization of trioxane with cyclic ethers or formals is accomplished with cationic initiators. All acetal resins contain various stabilizers introduced by the supplier. Acetal resins are most commonly fabricated by injection molding. They are used in conveying devices, gears, automotive parts, and household appliances.
Acetic Anhydride
Authors: Wagner Frank S. 
Published: July 2004

AbstractAcetic anhydride (CH3CO)2O, is a mobile, colorless liquid that has an acrid odor. It is the largest commercially produced carboxylic acid anhydride. Its chief industrial application is for acetylation reactions in the production of cellulose acetates. It is also used in many other applications in organic synthesis. Manufacturing processes include the acetic acid process, the acetaldehyde oxidation process, and methyl acetate carbonylation. Acetic anhydride penetrates the skin, forming burns and blisters.
Acrylonitrile
Authors: Brazdil James F. 
Published: July 2004

AbstractAcrylonitrile (also called acrylic acid nitrile, propylene nitrile, vinyl cyanide, and propenoic acid nitrile) is among the top 50 chemicals produced in the United States as a result of the tremendous growth in its use as a starting material for a wide range of chemical and polymer products. Acrylic fibers remain the largest use of acrylonitrile; other significant uses are in resins and nitrile elastomers and as an intermediate in the production of adiponitrile and acrylamide. Acrylonitrile (C3H3N, mol wt=53.064) is an unsaturated molecule having a carbon‐carbon double bond conjugated with a nitrile group. Acrylonitrile is miscible in a wide range of organic solvents, including acetone, benzene, carbon tetrachloride, diethyl ether, ethyl acetate, ethylene cyanohydrin, petroleum ether, toluene, some kerosenes, and methanol. Acrylonitrile undergoes a wide range of reactions at its two chemically active sites, the nitrile group and the carbon‐carbon double bond. Acrylonitrile is transported by rail car, barge, and pipeline. Department of Transportation (DOT) regulations require labeling acrylonitrile as a flammable liquid and poison. Acrylonitrile is highly toxic if ingested. It is moderately toxic if inhaled. Acrylonitrile is categorized as a cancer hazard by OSHA. Acrylonitrile will polymerize violently in the absence of oxygen if initiated by heat, light, pressure, peroxide, or strong acids and bases. It is combustible and ignites readily, producing toxic combustion products. Federal regulations (40 CFR 261) classify acrylonitrile as a hazardous waste. Uses of acrylonitrile include acrylic fiber, acrylonitrile–butadiene–styrene (ABS) resins, elastomers, and styrene‐acrylonitrile resins (SAN).
Acrylamide
Authors: Habermann C. E. 
Published: July 2004

AbstractAcrylamide (NIOSH No. A533250) has shown steady growth since the mid‐1950s, but is still considered a small‐volume commodity. It is by far the most important member of the series of acrylic and methacrylic amides. Water‐soluble polyacrylamides have the most important applications, including as a dewatering aid for sludge in the treatment of effluent from municipal wastewater plants and in industrial processes. Acrylamide, C3H5NO, is a difunctional monomer containing a reactive electron‐deficient double bond and an amide group. It undergoes reactions typical of those two functionalities. The current routes to acrylamide are based on the hydration of inexpensive and readily available acrylonitrile. Contact with acrylamide can be hazardous and should be avoided.
Acrylamide Polymers
Authors: Huang Sun‐Yi , Lipp David W. , Farinato Raymond S. 
Published: July 2004

AbstractThis article presents an up‐to‐date, broad overview of acrylamide polymers covering the physics, chemistry, synthesis, and technology. Acrylamide polymers constitute a major segment of the global water‐soluble polymers market. The physics and chemistry of acrylamide polymers and copolymers in both the solid and solution states are discussed. Chemical properties and synthetic methods for acrylamide polymerization, copolymerization, and polymer derivatization are throughly covered, as are commercial manufacturing processes. The principal applications of acrylamide polymers are discussed, and there is coverage of modern methods of polymer analysis as applied to these materials. Safety and economic issues are considered.
Aluminum Oxide (Alumina), Activated
Authors: Pearson Alan 
Published: July 2004

AbstractThe activated aluminas comprise a series of nonequilibrium forms of partially hydroxylated aluminum oxide, Al2O3. The chemical composition can be represented by\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{Al}}{_{2}}{\rm{O}} _{{(}3-x{)}}}$\end{document}(OH)2xwherexranges from about 0 to 0.8. They are porous solids made by thermal treatment of aluminum hydroxide precursors and find application mainly as adsorbents, catalysts, and catalyst supports. Activated alumina, for purposes of this discussion, refers to thermal decomposition products (excluding α‐alumina) of aluminum trihydroxides, oxide hydroxides, and nonstoichiometric gelatinous hydroxides. The term “activation” is used to indicate a change in properties resulting from heating (calcining). In general, as a hydrous alumina precursor is heated, hydroxyl groups are driven off, leaving a porous solid structure of activated alumina. The physical properties of the material are set by the choice of precursor, the forming process, and the activation conditions. Activated alumina is a relatively innocuous material from a health and safety standpoint. It is nonflammable and nontoxic. Normal precautions associated with handling of nuisance dusts should be taken. Activated alumina is normally shipped in moisture‐proof containers because of its strong desiccating action.
Adhesives
Authors: Yorkgitis Elaine M. 
Published: July 2004

AbstractAdhesives comprise one of the chief classes of polymer‐based products. Adhesive bonding is the method of choice for joining many materials, and their use can be expected to expand on a yearly basis because of their versatility and cost‐effectiveness. The market economics of adhesives is summarized and updated. The many ways in which adhesives can be classified is covered with an emphasis on their physical forms and types. The various chemistries used to make pressure‐sensitive, hot‐melt, solvent‐ and water‐based, structural, and natural product adhesives are described in some detail relative to the major constituents commonly used in each as well as the various minor constituents. The general advantages of each class of adhesive are provided. General comments on formulation and the role of the formulator in bringing adhesives to market conclude the article.
Adhesion
Authors: Pocius Alphonsus V. 
Published: July 2004

AbstractAdhesion is a complex phenomenon that is studied and described by three scientific disciplines: surface science, engineering mechanics, and polymer physics and chemistry. This article provides an overview of the science of adhesion based in those three disciplines. Adhesion is described primarily from the viewpoint of making and breaking an adhesive bond although the basic concepts also apply to coatings. This article describes adhesion from the viewpoint of intermolecular forces and ties those concepts into strength of materials as well as surface energy. Methods by which adhesive bonds can be tested are also described. The article ends with a discussion that attempts to tie together fundamental forces at interfaces to the strength of an adhesive bond via the polymer physics of the adhesive.
Adipic Acid
Authors: Oppenheim Judith P. , Dickerson Gary L. 
Published: July 2004

AbstractAdipic acid, hexanedioic acid, 1,4‐butanedicarboxylic acid, mol wt 146.14, HOOCCH2CH2CH,CH2COOH, is a white crystalline solid with a melting point of about 152°C. Little of this dicarboxylic acid occurs naturally, but it is produced on a very large scale at several locations around the world. The majority of this material is used in the manufacture of Nylon‐6,6 polyamide, which is prepared by reaction with 1,6‐hexanediamine. Adipic acid is a colorless, odorless, sour‐tasting crystalline solid that undergoes reactions including esterification, amidation, reduction, halogenation, salt formation, and dehydration. It also undergoes several industrially significant polymerization reactions. Adipic acid historically has been manufactured predominantly from cyclohexane. However, much research continues to be directed to alternative feedstocks, especially butadiene and cyclohexene, as dictated by shifts in hydrocarbon pricing. Air quality regulations may exert further pressure for alternative routes as manufacturers seek to avoid NOxabatement costs. When dispersed as a dust, adipic acid is subject to normal dust explosion hazards. The material is an irritant, especially upon contact with the mucous membranes. Protective goggles or face shields should be worn when handling the material. The material should be stored in corrosion‐resistant containers, away from alkaline or strong oxidizing materials. Adipic acid is a very large‐volume organic chemical and is one of the top 50 chemicals produced in the United States in terms of volume, although demand is highly cyclic. Adipic acid for nylon takes ∼60% of U.S. cyclohexane production. Adipic acid is relatively nontoxic.
Adsorption, Liquid Separation
Authors: Gembicki Stanley A. , Rekoske James , Oroskar Anil , Johnson James 
Published: July 2004

AbstractNearly every chemical manufacturing operation requires the use of separation processes to recover and purify the desired product. Liquid‐phase adsorption has long been used for the removal of contaminants present at low concentrations in process streams such as in deodorization of water, decolorization of sugar, and ion exchange of fermentation broth. Liquid‐phase simulated moving bed (SMB) processes are being increasingly used for bulk separation of a whole range of molecules whose molecular properties are very similar. Examples arep‐xylene from C8aromatics, normal paraffins from iso‐paraffins, fructose from glucose, and chiral molecules in the pharmaceutical industry. When it comes to the separation of close boiling molecules, SMB processes generally provide a better alternative to other conventional means of separation from both operating and capital costs point of view.This article reviews the application of liquid‐phase adsorption processes in the hydrocarbon, industrial chemicals, food, and pharmaceutical industry. Special emphasis is given to the class of processes referred to as SMB processes including fundamental SMB principles , and the general applicability and guidelines for SMB design. The paper also illustrates several examples of SMB applications in the petrochemical industry and its recent growth in the pharmaceutical and biotech industry.
Aerogels
Authors: Ko Edmond I. 
Published: July 2004

Abstract

Aerogels are low‐density and high‐porosity materials that are most commonly prepared by removing the pore liquid from a wet gel with supercritical extraction. The most extensively studied and characterized are silica aerogels, which can be prepared in the density range of 3 to 500 kg/m
3
through a proper control of preparative variables. The unusual properties of these materials, such as high surface area and pore volume, low thermal conductivity, and low dielectric constant, make them attractive for applications in diverse areas including thermal insulation, detection of high energy particles, and catalysis. The challenge is to produce them in a cost‐competitive process, which means exploring options that do not involve supercritical drying. Recent results show that with surface modification, aerogel‐like materials can indeed be produced at ambient conditions. Other ongoing research has been directed at the preparation and characterization of nonsilicate aerogels, as well as organic and inorganic–organic hybrid materials in an attempt to define their properties and to identify potential applications.