bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and pervaporation performance of 3,3‐bis[4‐(4‐aminophenoxy)phenyl] phthalide based polyimide membranes
Authors: Wang Y. C. , Tsai Y. S. , Lee K. R. , Lai J. Y. 
Published: April 2005

AbstractA series of novel solvent‐soluble polyimides based on the diamine of 3,3‐bis[4‐(4‐aminophenoxy)phenyl] phthalide (BAPP) were prepared. The effects of the dianhydride structures on the pervaporation performance of aqueous alcohol mixtures through these polyimide membranes were studied. The BAPP‐based polyimide membranes exhibited water permselectivity during all process runs. The permeation rate increased with the addition of bulky groups to the polyimide backbone. The effects of the feed solution concentration, feed solution temperature, and carbon atom number of the feed alcohol on the pervaporation performance were also investigated systematically. Optimum pervaporation results, a separation factor of 22 and a permeation rate of 270 g/m2 h, were obtained for a 90 wt % feed aqueous ethanol solution through a 3,3′,4,4′‐biphenyl tetracarboxylic dianhydride polyimide membrane at 25°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2046–2052, 2005
Preparation of ultra‐low‐density microcellular materials
Authors: Richez Alexandre , Deleuze Hervé , Vedrenne Patrick , Collier Remy 
Published: April 2005

AbstractMicrocellular polymeric materials can be obtained by the polymerization of a high‐internal‐phase emulsion. These materials are good candidates as targets toward inertial confinement fusion. This application requires severe specifications, including a very low density and a small cell size. In this study, we examined the influence of parameters such as emulsification conditions, surfactant nature, and the presence of a porogen on the obtainment of those requirements. It was possible to obtain microcellular polymeric foams with apparent densities as low as 0.0126 g/cm3. However, it was difficult to obtain very low material density and still maintain a small average pore size. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2053–2063, 2005
Phase behavior of ternary polymer blends with favorable interactions
Authors: Hsu Wen‐Ping 
Published: April 2005

AbstractAtactic poly(methyl methacrylate) (aPMMA) and poly(vinyl pyrrolidone) (PVP) with a weight‐average molecular weight of 360,000 g/mol were found to be immiscible on the basis of preliminary studies. Poly(styrene‐co‐vinyl phenol) (MPS) with a certain concentration of vinyl phenol groups is known to be miscible with both aPMMA and PVP. Is it possible to homogenize an immiscible aPMMA/PVP pair by the addition of MPS? For this question to be answered, a ternary blend consisting of aPMMA, PVP, and MPS was prepared and measured calorimetrically. The role of MPS between aPMMA and PVP and the effects of different concentrations of vinyl phenol groups on the miscibility of the ternary blends were investigated. According to experimental results, increasing the vinyl phenol contents of MPS has an adverse effect on the miscibility of the ternary blends. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2064–2070, 2005
Dielectric behavior and properties of a cyanate ester containing dicyclopentadiene. I
Authors: Hwang Hann‐Jang , Li Chun‐Hung , Wang Chun‐Shan 
Published: April 2005

Abstract2,6‐Dimethyl phenol dicyclopentadiene dicyanate ester (DCPDCY) was synthesized through the reaction of 2,6‐dimethyl phenol dicyclopentadiene novolac and cyanogen bromide. The proposed structure was confirmed by Fourier transform infrared, mass spectrometry, NMR spectrometry, and elemental analysis. DCPDCY was then cured by itself or cured with bisphenol A dicyanate ester (BADCY) to form triazine structures. The thermal properties of the cured DCPDCY resins were studied with differential scanning calorimetry, dynamic mechanical analysis (DMA), dielectric analysis, and thermogravimetric analysis; these data were compared with those of BADCY. The cured DCPDCY resins exhibited a lower dielectric constant (2.58 at 1 MHz), a lower dissipation factor (20.2 mU at 1 MHz), less thermal stability (the 5% degradation temperature and char yield were 430°C and 32.1%, respectively), a lower glass‐transition temperature (266°C by thermomechanical analysis and 271°C by DMA), a lower coefficient of thermal expansion (22.5 ppm before the glass‐transition temperature and 124.9 ppm after the glass‐transition temperature), and less moisture absorption (0.88% at 48 h) than BADCY, but they showed higher moduli (6.28 GPa at 150°C and 5.35 GPa at 150°C) than the bisphenol A system. The properties of the cured cocyanate esters (DCPDCY and BADCY) lay between those of cured BADCY and DCPDCY, except for the moduli. The moduli of some cocyanate esters were even higher than those of cured BADCY and DCPDCY. A positive deviation from the Fox equation was observed for cocyanate esters. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2079–2089, 2005
Effects of propionyl content on the morphology, mechanical properties, and biodegradability of esterified cassava starch/polycaprolactone blends
Authors: Wootthikanokkhan J. , Santikunakorn S. 
Published: April 2005

AbstractThe chemical structure of cassava starch was modified via an acylation with two different reaction systems: propionic anhydride in an aqueous sodium hydroxide solution and propionic anhydride in dimethyl sulfoxide/triethylamine mixtures. The acylation was carried out by the variation of reaction parameters to generate modified starches with a variety of propionyl contents. After that, the modified starch was blended with polycaprolactone (PCL) at a 30/70 weight composition in a twin‐screw extruder. The results from the tensile testing of the various modified starch/PCL blends show that the moduli and tensile stresses of the materials were higher than those of the unmodified starch/PCL blend. The elongation values of the modified starch/PCL blends, however, decreased with the propionyl content. Scanning electron micrographs of the blends containing modified starch with 62 and 80% propionyl were also different from those of blends containing modified starch with 16 and 28% propionyl in term of phase contrast. Finally, the rate of biodegradation of the blends decreased with increasing propionyl content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2154–2162, 2005
Polycarbonate/acrylonitrile–styrene–acrylic elastomer terpolymer blends with enhanced interfacial adhesion and surface gloss
Authors: Seo Y. S. , Kim J. H. , Kim C. K. , Lee Ryul , Keum J. K. 
Published: April 2005

AbstractA blend of bisphenol A polycarbonate (PC) and an acrylonitrile–styrene–acrylic elastomer (ASA) terpolymer with high surface gloss and excellent interfacial properties was developed for automobile applications. Because PC and the styrene‐co‐acrylonitrile (SAN) copolymer that formed the matrix in the PC/ASA blend were not miscible, two different types of compatibilizers were examined to improve the compatibility of the blend. A diblock copolymer composed of tetramethyl polycarbonate and poly(methyl methacrylate) (PMMA) was more effective than PMMA in increasing interfacial adhesion between PC and SAN. The surface gloss of the PC/ASA blend was always lower than that of the pure ASA included in the blend because of PC existing at the surface of the injection‐molding specimen. The PC/ASA blend with optimum surface gloss and enhanced interfacial adhesion was developed through the control of the molecular weight of PC and the compatibilizer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2097–2104, 2005
Malassezin, a Novel Agonist of the Aryl Hydrocarbon Receptor from the Yeast Malassezia furfur, Induces Apoptosis in Primary Human Melanocytes
Authors: Krämer Hans‐Joachim , Podobinska Monika , Bartsch Andrea , Battmann Achim , Thoma Wiebke , Bernd August , Kummer Wolfgang , Irlinger Bernhard , Steglich Wolfgang , Mayser Peter 
Published: April 2005

AbstractPityriasis versicolor is the most common skin mycosis in humans worldwide. Yeasts of the genus Malassezia, particularly M. furfur, a saprophyte occurring widely on human skin, are generally regarded as the causative agents. Pityriasis versicolor is often accompanied by a long‐lasting depigmentation that persists even after successful antimycotic therapy. M. furfur is able to convert tryptophan into a variety of indole alkaloids, some of them showing biological properties that correlate well with certain clinical features of pityriasis versicolor. This suggests a possible role for these compounds in the depigmentation process. We now report that human melanocytes undergo apoptosis when exposed to the crude mixture of tryptophan metabolites from M. furfur. The active compound was identified as malassezin, previously isolated by us from the same source and characterized as an agonist of the aryl hydrocarbon (Ah) receptor. The compound could, therefore, contribute to the marked depigmentation observed during the course of pityriasis versicolor.
Investigation of Molecular Beacon Aptamer‐Based Bioassay for Platelet‐Derived Growth Factor Detection
Authors: Vicens Marie C. , Sen Arup , Vanderlaan Andrew , Drake Timothy J. , Tan Weihong 
Published: April 2005

AbstractThis report describes studies on the use of a molecular‐beacon aptamer (MBA) as a synthetic high‐affinity DNA probe that exhibits fluorescence resonance energy transfer (FRET) in response to a specific protein biomarker, platelet‐derived growth factor (PDGF). As a step toward the application of the MBA in a fluorescence‐based assay for biological specimens, we examined the influence of certain physical and chemical parameters of incubation that would affect DNA conformation and DNA‐backbone modification, and thus improve nuclease resistance. This bioassay is compatible with pH, temperature, and monovalent cation levels typically encountered in biological samples, and phosphorothioate backbone‐modified MBA is able to exhibit specific FRET. With minimal sample processing and without assay optimization, the MBA is able to detect as little as 10 ng PDGF per μg of serum proteins from cell‐culture media. We also show that different sets of known fluorophore–quencher pairs can be successfully used in the MBA for sensitive detection of the PDGF target. It should, therefore, be possible to develop multiplex bioassays that monitor either quenching or enhancement for the simultaneous detection of several biomarkers by using MBAs created from high‐affinity DNA ligands for the desired protein targets. Interestingly, we observed that, with a DNA ligand with multiple binding sites for a standard multimeric protein target, the FRET bioassay could be accomplished by using a mixture of two individually labeled DNAs—one carrying the fluorophore and the other with the matching quencher. This observation has significant implications in the future design of more selective DNA‐based FRET bioassays that use more than one ligand for the same protein target.
A Novel Homogenous Assay for Topoisomerase II Action and Inhibition
Authors: Jahnz Michael , Medina Miguel Ángel , Schwille Petra 
Published: April 2005

AbstractTopoisomerase II is the only enzyme able to cleave and religate double‐stranded DNA; this makes it essential for many vital functions during normal cell growth. Increased expression of topoisomerase II is a common occurrence in neoplasia, and different topoisomerase II inhibitors have indeed been proven to be powerful anticancer drugs. For this reason, the topoisomerase II catalytic cycle has attracted strong interest, but only a few techniques contributing to studies in this field have emerged. All of the currently used conventional methods to elucidate the action and inhibition of topoisomerase II require separation steps and are therefore unsatisfactory in terms of sensitivity, speed, and throughput. Here, for the first time, we present an assay that works in homogenous solution. The assay is based on dual‐color fluorescence cross‐correlation spectroscopy (DC‐FCCS) and allows monitoring of topoisomerase II action and, especially, detection and discrimination of different topoisomerase II inhibitor classes. The effectiveness of our new assay was confirmed by measuring the effects of a catalytic inhibitor (novobiocin) and a topoisomerase poison (m‐AMSA) with bacteriophage T4 topoisomerase as a model system, thus showing the strategy to be easy, fast, and extremely sensitive. Further development of the DC‐FCCS‐based assay and subsequent application in high‐throughput drug screening of new anticancer drugs is proposed and discussed.
Discovery of Powerful Uranyl Ligands from Efficient Synthesis and Screening
Authors: Sawicki Marcin , Siaugue Jean‐Michel , Jacopin Christophe , Moulin Christophe , Bailly Théodorine , Burgada Ramon , Meunier Stéphane , Baret Paul , Pierre Jean‐Louis , Taran Frédéric 
Published: April 2005

AbstractNew tripodal gem‐(bis‐phosphonates) uranophiles were discovered by a screening method that allowed for the selection of ligands with strong uranyl‐binding properties in a convenient microtiter‐plate format. The method is based on competitive uranium binding by using Sulfochlorophenol S as chromogenic chelate. This dye compound was found to present high uranyl complexation properties and allowed to highlight ligands presenting association constants for ${{\rm UO}{{2+\hfill \atop 2\hfill}}}$ up to 1018 at pH 7.4 and 1020 at pH 9. A collection of 40 known ligands including polycarboxylate, hydroxamate, catecholate, hydroxypyridonate and hydroxyquinoline derivatives was tested. Also screened was a combinatorial library prepared from seven amine scaffolds and eight acrylates bearing diverse chelating moieties. Among these 96 tested candidates, a tripod derivative bearing gem‐bis‐phosphonates moieties was found to present the highest complexation properties over a wide range of pH and was further studied.
The Structure of Acrolein in a Liquid Crystal Phase
Authors: Celebre Giorgio , Concistrè Maria , De Luca Giuseppina , Longeri Marcello , Pileio Giuseppe , Emsley James William 
Published: April 2005

AbstractThe 1H NMR spectrum of a sample of acrolein dissolved in the nematic liquid crystal phase I52 has been analysed to yield 18 dipolar couplings between all the magnetic nuclei in the molecule; moreover, the 13C and 13C{1H} NMR spectra of a sample of acrolein in CDCl3 were recorded and analysed to determine the indirect Jij couplings. The data were used to obtain the relative positions of the carbon and hydrogen atoms, assuming that these are independent of the conformations generated by rotation around the CC bond through an angle ϕ, and to obtain a probability distribution P(ϕ). It has been found that in the liquid phase, the distribution is a maximum at the trans form whereas the abundance of the cis form is significantly smaller compared with that found by microwave spectroscopy or high level quantum mechanical calculations. Such calculations produced also a suitable force field needed to develop suitable strategies for vibrational correction procedure in the case of flexible molecules.
Diversity Oriented Synthesis of Hispanane‐like Terpene Derivatives from (R)‐(+)‐Sclareolide
Authors: de la Torre María C. , García Isabel , Sierra Miguel A. 
Published: April 2005

Abstract(R)‐(+)‐Sclareolide 1 has been used as a starting material to develop a diversity oriented methodology to access hispanane 28 a, and hispanane‐like derivatives 27 b–27 e. This methodology is based on the intramolecular Friedel–Crafts acylation of the corresponding 12‐desoxylabdanoic‐like acids 27, for the construction of the cycloheptane ring which is characteristic of the hispananes. Acids 27 are obtained from alcohols 20, available by addition of the lithium or magnesium reagents to amide 12 (followed by Luche reduction), or to aldehyde 21. This sequence has resulted in the preparation of hispanane framework 27 a. The versatility of this methodology therefore allows a structural diversity oriented synthesis, since it allows the access to a wide variety of hispanane‐like derivatives.
Fluorescent Probes for Sensing Processes in Polymers
Authors: Bosch Paula , Catalina Fernando , Corrales Teresa , Peinado Carmen 
Published: April 2005

AbstractFluorescence spectroscopy is an important analytical technique that has been widely used in a variety of applications, such as biomedicine, biology, and science of materials, because it presents some properties which makes it unique, that is, extraordinary sensitivity and selectivity, short delay time (<10−9 s), and it is neither invasive nor destructive, so it can be used for in situ measurements. Generally, intrinsic fluorescence of many materials, like polymers, is unspecific so it is not useful to analyse their properties or to be correlated to changes in their microenvironment. The incorporation of additives with fluorescent groups would be necessary. When the fluorescence emission of these molecules is sensitive to changes of properties, such as polarity, fluidity, order, molecular mobility, pH, or electric potential, they can be used for detecting such changes in their microenvironment, and they are called fluorescent probes. As long as these probes can follow processes of practical interest, they can be employed as sensors, if the information given by the measure of fluorescence adequately reflects the changes in the system. In addition, a sensor must fulfil some other requirements in order to make them of practical use, the most important being that the material support in which the sensor molecule is inserted. This support should permit a rapid detection of the process and should allow easy processing in a variety of forms. Polymers are well‐known systems in which estimation of local parameters are possible by means of fluorimetric techniques. It allows the study of dynamic processes of interest, such as polymerization kinetics and mechanisms, thermal transitions, photodegradation, swelling morphology changes, and so forth.
Chemical Vapor Transport of Solid Solutions. Part 15. Chemical Vapor Transport of Mixed Phases in the Systems TiS2/TiSe2, TiS2/TaS2, TiS2/TaSe2 and TaS2/TaSe2.
Authors: Hotje U. , Wartchow R. , Binnewies M. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oxidative Addition of N‐Aminophthalimide and 3‐Amino‐2‐methylquinazolin‐4(3H)‐one to Conjugated Azocyclopentenes and Azocyclohexenes.
Authors: Buchaka S. M. , Kuznetsov M. A. , Schantl J. G. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Cyclization of 1‐Bromo‐2,7‐ and 1‐Bromo‐2,8‐enynes Mediated by Indium.
Authors: Lee Phil Ho , Kim Sundae , Lee Kooyeon , Seomoon Dong , Kim Hyunseok , Lee Seokju , Kim Misook , Han Mijeong , Noh Kwanghyun , Livinghouse Tom 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Practical and User‐Friendly Method for the Selenium‐Free One‐Step Preparation of 1,2‐Diketones and Their Monoxime Analogues.
Authors: Rueedi Georg , Oberli Matthias A. , Nagel Matthias , Weymuth Christophe , Hansen Hans‐Juergen 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Wet Alumina‐Supported Chromium (VI) Oxide: A Mild, Efficient, and Inexpensive Reagent for Oxidative Deoximation.
Authors: Heravi Majid M. , Ajami Darush , Shoar Rahim Hekmat , Sarmad Nooshin , Faridbod Farnoush 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oxidative Deprotection of Trimethylsilyl Ethers with Hexamethylenetetraminebromine Supported onto Silica Gel under Microwave Irradiation in Solventless System.
Authors: Dehkordi Mahboobeh Behnam , Heravi Majid M. , Khosrofar Parviz , Ziafat Ahmad , Ghassemzadeh Mitra 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Immobilization of Rh‐MonoPhos on the Aluminosilicate AlTUD‐1.
Authors: Simons Chretien , Hanefeld Ulf , Arends Isabel W. C. E. , Minnaard Adriaan J. , Maschmeyer Thomas , Sheldon Roger A. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Facile and Environmentally Benign Zn‐Mediated Cyclopropanation of Electron‐Deficient 2‐Iodoethyl‐Substituted Olefins via Radical 3‐exo‐trig Manner.
Authors: Sakuma Daisuke , Togo Hideo 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Convenient and Efficient Synthesis of 1‐Aryl‐2,2‐dichloroethanones.
Authors: Terent'ev Alexander O. , Khodykin Sergey V. , Troitskii Nikolay A. , Ogibin Yuri N. , Nikishin Gennady I. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Mild and Efficient Procedure for the Preparation of Dimethyl and Diallyl Acetals of Aromatic Aldehydes Mediated by Cerium(IV) Ammonium Nitrate.
Authors: Nair Vijay , Rajan Roshini , Balagopal Lakshmi , Nair Latha G. , Ros Sindu , Mohanan Kishor 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Effect of Tether Length on Ti(III)‐Mediated Cyclization of Epoxyalkenes and Unsaturated Epoxyketones.
Authors: Fernandez‐Mateo A. , Mateo Buron L. , Martin de la Nava E. M. , Rabanedo Clemente R. , Rubio Gonzalez R. , Sanz Gonzalez F. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Propargylic Carbenoids. Part 4. High Kinetic Resolution in the Addition of a Racemic Allenylzinc onto Enantiopure N‐tert‐Butanesulfinimines: Concise Synthesis of Enantiopure trans‐2‐Ethynylaziridines.
Authors: Chemla Fabrice , Ferreira Franck 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Facile Regiocontrol in the Palladium‐Catalyzed Annulation of Fluorine‐Containing Internal Alkynes with Variously Substituted 2‐Iodoanilines: A New Regioselective Synthesis of 2‐ or 3‐Fluoroalkylated Indole Derivatives.
Authors: Konno Tsutomu , Chae Jungha , Ishihara Takashi , Yamanaka Hiroki 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 2‐Arylbenzothiazoles and Imidazoles Using Scandium Triflate as a Catalyst for Both a Ring Closing and an Oxidation Steps.
Authors: Itoh Takashi , Nagata Kazuhiro , Ishikawa Hiroyuki , Ohsawa Akio 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Reaction of Activated cyanoarylidenes with β‐Keto‐δ‐carbethoxyphosphonates and Phosphine Oxides: Synthesis of 2‐Amino‐6‐(phosphonomethyl)‐4H‐pyrans.
Authors: Said Noureddine , Touil Soufiane , Zantour Hedi 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 5‐Bromopyridyl‐2‐magnesium Chloride and Its Application in the Synthesis of Functionalized Pyridines
Authors: Song Jinhua J. , Yee Nathan K. , Tan Zhulin , Xu Jinghua , Kapadia Suresh R. , Senanayake Chris H. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Cyclocondensation of 2‐Fluoro‐5‐nitrobenzaldehyde with Amidines. New Synthesis of Isoquinolines.
Authors: Dar'in D. V. , Selivanov S. I. , Lobanov P. S. , Potekhin A. A. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Studies on the Generation of Enolate Anions from Butane‐2,3‐diacetal Protected Glycolic Acid Derivatives and Subsequent Highly Diastereoselective Coupling Reactions with Aldehydes and Acid Chlorides.
Authors: Ley Steven V. , Dixon Darren J. , Guy Richard T. , Palomero Maria A. , Polara Alessandra , Rodriguez Felix , Sheppard Tom D. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Intramolecular Nucleophilic Aromatic Substitution Reaction of 2‐Carboxamido‐3‐arylquinazolin‐4‐ones and Its Application to the Synthesis of Secondary Aryl Amines.
Authors: Fuwa Haruhiko , Kobayashi Toshitake , Tokitoh Takashi , Torii Yukiko , Natsugari Hideaki 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Anellated Derivatives of Tetrafluoro‐10H‐imidazo[1,2‐b][1,2]benzooxazin‐10‐one and 2‐Pentafluorophenylpyrazine 1,4‐Dioxide by Condensation of Alicyclic 2‐Hydroxyamino Oximes with Pentafluorophenylglyoxal.
Authors: Amitina S. A. , El'tsov I. V. , Rybalova T. V. , Gatilov Yu. V. , Grigor'ev I. A. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.