bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of polymeric emulsifiers on the properties of acrylic emulsion pressure‐sensitive adhesives
Authors: Park Myung‐Chul , Lee Myung Cheon 
Published: September 2004

AbstractA series of polymeric emulsifiers was polymerized with 2‐ethylhexyl acrylate, butyl acrylate, and acrylic acid. The polymeric emulsifiers were used to make emulsion copolymers of 2‐ethylhexyl acrylate, butyl acrylate, and acrylic acid. The average particle size of the synthesized emulsions was around 145 nm and the size distribution was very narrow. Also, the emulsions showed good freeze–thaw stability and adhesion properties. The peel strength and holding power of the emulsions were investigated by changing the composition and molecular weight of the polymeric emulsifier. The results show that the peel strength exhibits a maximum at particular molecular weight and acrylic acid content of the polymeric emulsifier, while the holding power increases with molecular weight. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1456–1460, 2004
Stem and bunch banana fibers from cultivation wastes: Effect of treatments on physico‐chemical behavior
Authors: Gañán Piedad , Cruz Javier , Garbizu Saioa , Arbelaiz Aitor , Mondragon Iñaki 
Published: September 2004

AbstractMuch research related to the use of natural fibers in polymeric matrix composites has been developed. The presence of OH groups in the chemical components of the natural fibers generates an important hydrophylic tendency that produces adhesion lacks with hydrophobic polymeric matrices. In this work natural fiber bundles mechanically extracted from both stem and bunch of cultivation banana wastes have been modified by both alkalization and silanization treatments. To evaluate the changes introduced by treatments on the chemical structure of fibers, Fourier‐transform infrared spectrophotometry has been employed. The evaluation of advancing dynamic contact angles along with the determination of total surface free energy by using the Owens–Wendt method indicate that the treatments allow reduction of their hydrophilic tendency by alterations on the physicochemical characteristics of the fibers. This behavior is confirmed by the reduction of moisture uptake, analyzed by thermogravimetric analysis. Small differences on noncellulosic components of stem and bunch fiber bundles have been found. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1489–1495, 2004
Effects of silane coupling agents on the vulcanization characteristics of natural rubber
Authors: Yan Hexiang , Sun Kang , Zhang Yong , Zhang Yinxi , Fan Yongzhong 
Published: September 2004

AbstractThe vulcanization characteristics of silica‐filled natural rubber (NR) were studied in the presence of silane coupling agents, 3‐octanoylthio‐1‐propyltriethoxysilane (NXT) and bis [(3‐triethoxysilylpropyl) tetra sulfide] (TESPT, or Si‐69). The scorch time, cure rate index, and the rate constant of NR were measured using an Oscillating Disk Rheometer in the temperature range of 140–170°C. The scorch time of NR decreases with increasing TESPT and NXT concentrations, and the scorch time of NR compound with NXT is longer than that with TESPT. The apparent activation energies of vulcanization for the compounds with NXT and TESPT both decrease with increasing silane concentration. The apparent activation energy of vulcanization of NR compound with NXT is lower than that with TESPT at various concentrations. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1511–1518, 2004
Preparation and determination of swelling behavior of poly(acrylamide‐co‐acrylic acid) hydrogels in water
Authors: Isık Belma , Kıs Mehmet 
Published: September 2004

AbstractHydrogels with varying crosslinking densities were prepared from the acrylamide/acrylic acid and acrylamide/acrylic/poly(ethylene glycol) systems by the redox copolymerization method. Average molecular weights between crosslinks, percent swelling, swelling equilibrium values, and diffusion/swelling characteristics (i.e., the structure of network constant, the type of diffusion the initial swelling rate, diffusion coefficients, and swelling rate constant) were evaluated for both hydrogel systems. The prepared hydrogels have shown mass swelling capabilities in the range of 663–755% (for AAm/AA hydrogels) and 635–800% (for AAm/AA/PEG 4000 hydrogels). Water diffusion into hydrogels was found to be non‐Fickian type diffusion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1526–1531, 2004
Toward an understanding of the genetics of murine cardiac pacemaking and conduction system development
Authors: Myers Dina C. , Fishman Glenn I. 
Published: September 2004

AbstractWe distinguish the cardiac pacemaking and conduction system (CPCS) from neighboring working cardiomyocytes by its function to generate and deliver electrical impulses within the heart. Yet the CPCS is a series of integrated but distinct components. The components must act in a coordinated fashion, but they are also functionally, molecularly, and electrophysiologically unique. Understanding the differentiation and function of this elegant and complex system is an exciting challenge. Knowledge of genes and signaling pathways that direct CPCS development is at present minimal, but the use of transgenic mice represents an enormous opportunity for elucidating the unknown. Transgenic marker lines have enabled us to image and manipulate the CPCS in new ways. These tools are now being used to examine the CPCS in mutants where its formation and function is altered, generating new information and directions for study of the genetics of CPCS development. © 2004 Wiley‐Liss, Inc.
Dense genome‐wide linkage analysis of rheumatoid arthritis, including covariates
Authors: Osorio y Fortéa José , Bukulmez Hulya , Petit‐Teixeira Elisabeth , Michou Laétitia , Pierlot Céline , Cailleau‐Moindrault Séverine , Lemaire Isabelle , Lasbleiz Sandra , Alibert Olivier , Quillet Patrick , Bardin Thomas , Prum Bernard , Olson Jane M. , Cornélis François 
Published: September 2004

AbstractObjectiveRheumatoid arthritis (RA) is a heterogeneous disease that exhibits a complex genetic component. Previous RA genome scans confirmed the involvement of the HLA region and generated data on suggestive signals at non‐HLA regions, albeit with few overlaps in findings between studies. The present study was undertaken to detect potential RA gene regions and to estimate the number of true RA gene regions, taking into account the heterogeneity of RA, through performance of a dense genome scan.MethodsIn a study of 88 French Caucasian families (105 RA sibpairs), 1,088 microsatellite markers were genotyped (3.3‐cM genome scan), and a multipoint model‐free linkage analysis was performed. The statistical assessment of the results relied on 10,000 computer simulations. A covariate‐based multipoint model‐free linkage analysis was performed on the locations of regions with suggestive evidence for linkage.ResultsInvolvement of the HLA region was strongly confirmed (P = 6 × 10−5), and 19 non‐HLA regions showed suggestive evidence for linkage (P < 0.05); 9 of these overlapped with regions suggested in other published RA genome scans. A routine 12‐cM genome scan with the same families would have detected only 7 of the 19 regions, including only 4 of the 9 overlapping regions. From the 10,000 computer simulations, we estimated that 8 ± 4 regions (mean ± SD) were true‐positives. RA covariate–based analysis provided additional linkage evidence for 3 regions, with age at disease onset, erosions, and HLA–DRB1 shared epitope as covariates.ConclusionThe results of this study provide evidence of 19 non‐HLA RA gene regions, with an estimate of 8 ± 4 as true‐positives, and provide additional evidence for 3 regions from covariate‐based analysis.
Selective gray matter damage in neuropsychiatric lupus
Authors: Steens S. C. A. , Admiraal‐Behloul F. , Bosma G. P. Th. , Steup‐Beekman G. M. , Olofsen H. , le Cessie S. , Huizinga T. W. J. , van Buchem M. A. 
Published: September 2004

AbstractObjectiveDamage of brain parenchyma in patients with primary diffuse neuropsychiatric systemic lupus erythematosus (NPSLE) has been indicated by magnetization transfer imaging (MTI). However, the location of MTI abnormalities is unknown. This study was undertaken to assess the distribution of MTI abnormalities over gray matter (GM) and white matter (WM) in SLE patients with a history of NP symptoms without explanatory magnetic resonance imaging (MRI) evidence of focal disease.MethodsMTI was performed in 24 female SLE patients with a history of diffuse NP symptoms and 24 healthy female controls. Magnetization transfer ratio (MTR) maps were calculated for GM and WM separately, and GM and WM MTR histograms were generated. Univariate and multivariate analyses with age as an additional covariate were performed on the histogram parameters peak location (PL), peak height (PH), and mean MTR.ResultsCompared with controls, significantly reduced PH (mean ± SD 136 ± 22 arbitrary units versus 151 ± 13 arbitrary units) and mean MTR (33.3 ± 1.0 percent units versus 33.6 ± 0.5 percent units) were found in the GM of NPSLE patients (P = 0.002 and P = 0.033, respectively, in multivariate analyses). No significant differences were observed for WM MTR parameters.ConclusionThis is the first study to demonstrate, using MTI, that in SLE patients with a history of NP symptoms and without explanatory focal abnormalities on MRI, the GM is particularly affected. These findings support the hypothesis that neuronal injury may underlie central nervous system manifestations in NPSLE.
Studies on atmospheric turbidity over a tropical urban environment
Authors: Madhavi Latha K. , Badrinath K. V. S. 
Published: September 2004

AbstractThe particulate pollution in the atmosphere can be assessed using various methods like measuring aerosol mass concentration, aerosol optical depth, number density of airborne particles, etc. In the present study, measurements on aerosol optical depth using sunphotometer, aerosol mass concentration in different size ranges using QCM particle analyzer and black carbon aerosol using Aethalometer have been carried out during January to May, 2003, to characterize the atmospheric turbidity over Hyderabad. Spectral variation of aerosol optical depth suggests dominance of accumulation mode particles over the study area. Frequency analysis of turbidity coefficient suggests that polluted atmosphere is prevailing over the study area. Measured values of turbidity parameters in the present study have been compared with that in other major cities of the world and the results are discussed in the article. Copyright © 2004 Royal Meteorological Society
Sigmund Freud und die Lauterkeit
Authors: Gundlach Horst 
Published: September 2004

AbstractIn his carrier as physician, Sigmund Freud claimed various and surprising successes in healing patients. An evaluation of those cases in which evidence independent of Freud's publications has been discovered reveals a lifelong pattern of Freud claiming successes, patients, however, not being cured, and Freud being aware of this. The elements of this pattern are matched with the components of the legal definition of fraud.
The design of a potent inhibitor of the hepatitis C virus NS3 protease: BILN 2061—From the NMR tube to the clinic
Authors: Tsantrizos Youla S. 
Published: September 2004

AbstractThe virally encoded serine protease NS3/NS4A is essential to the life cycle of the hepatitis C virus (HCV), an important human pathogen causing chronic hepatitis, cirrhosis of the liver, and hepatocellular carcinoma. Until very recently, the design of inhibitors for the HCV NS3 protease was limited to large peptidomimetic compounds with poor pharmacokinetic properties, making drug discovery an extremely challenging endeavor. In our quest for the discovery of a small‐molecule lead that could block replication of the hepatitis C virus by binding to the HCV NS3 protease, the critical protein–polypeptide interactions between the virally encoded NS3 serine protease and its polyprotein substrate were investigated. Lead optimization of a substrate‐based hexapeptide, guided by structural data, led to the understanding of the molecular dynamics and electronic effects that modulate the affinity of peptidomimetic ligands for the active site of this enzyme. Macrocyclic β‐strand scaffolds were designed that allowed the discovery of potent, highly selective, and orally bioavailable compounds. These molecules were the first HCV NS3 protease inhibitors reported that inhibit replication of HCV subgenomic RNA in a cell‐based replicon assay at low nanomolar concentrations. Optimization of their biopharmaceutical properties led to the discovery of the clinical candidate BILN 2061. Oral administration of BILN 2061 to patients infected with the hepatitis C genotype 1 virus resulted in an impressive reduction of viral RNA levels, establishing proof‐of‐concept for HCV NS3 protease inhibitors as therapeutic agents in humans. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Mono‐, bi‐, or tridentate ligands? The labeling of peptides with 99mTc‐carbonyls
Authors: Alberto Roger , Kyong Pak Jae , van Staveren Dave , Mundwiler Stefan , Benny Paul 
Published: September 2004

AbstractThe labeling of targeting peptides with 99mTc is a useful concept for the diagnosis of various diseases such as cancer. Although in research for at least one decade, only a very few radiopharmaceuticals based on peptides are in clinical use. The difficulty of labeling, and the resulting authenticity of the new vector, is largely responsible for this observation. In this overview, we present an alternate strategy based on the organometallic fac‐[99mTc(CO)3]+ core for introducing 99mTc in biomolecules in general and in peptides in particular. The three coordination sites available in [99mTc(OH2)3(CO)3]+ can be occupied with many different ligand types, pendant to a biomolecule and serving as the anchor group for labeling. This makes the appropriate choice difficult. We intend to present some useful concepts for the practice. Monodentate chelators are robust but bear the risk of multiple binding of biomolecules. Coordinating a bidentate ligand of choice prior to labeling bypasses this problem and enables a systematic drug discovery by variation of the bidentate ligand. Bidentate ligands attached to the biomolecule are stronger but occasionally require protection of the remaining site by a monodentate ligand. Both approaches refer to a mixed‐ligand [2+1] approach. Tridentate chelators are the most efficient but need some protecting group chemistry in order to achieve selectivity for the coupling process. Examples with cysteine and histidine are presented. This article aims to provide versatile and reproducible approaches for the labeling of biomolecules while not focusing on particular systems. It should be left to the readers to derive a strategy for their own peptide. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Das Biohistoricum in Neuburg an der Donau
Authors: Geus Armin 
Published: September 2004

AbstractDie kritische Besinnung auf Vorgedachtes und Vorgemachtes gehört zum Wesen jeder wissenschaftlichen Arbeit. Doch im steten Wechsel der Interessen gehen häufig wertvolle Unterlagen für immer verloren. Das Biohistoricum in Neuburg an der Donau möchte als außeruniversitäres, nichtstaatliches Museum und Forschungsarchiv für die Geschichte der Biologie den nachfolgenden Generationen einen Rückgriff auf schriftliche und sachliche Quellen biologischen Denkens ermöglichen.
Perfekte Bewerbungsunterlagen
Authors: Debus‐Spangenberg Isolde 
Published: September 2004

AbstractDas Kernstück aller Bewerbungsaktivitäten sind die Bewerbungsunterlagen. Bei der Gestaltung dieser Unterlagen sollten Sie immer im Hinterkopf haben: Der Leser will erkennen, ob Sie qualifiziert, motiviert und sympathisch sind. Die Medienwissenschaftlerin und Karriereberaterin Isolde Debus‐Spangenberg gibt Tipps, wie man sich mit optimalen Unterlagen perfekt präsentiert.
NMR Structural Model of the Interaction of Herbicides with the Photosynthetic Reaction Center from Rhodobacter sphaeroides
Authors: D'Amelio Nicola , Gaggelli Elena , Mlynarz Piotr , Molteni Elena , Valensin Gianni , Lubitz Wolfgang 
Published: September 2004

AbstractThe interaction of the herbicides acifluorfen and paraquat with the photosynthetic reaction center from Rhodobacter sphaeroides has been studied by NMR relaxation measurements. Interaction in aqueous solution has been demonstrated by evaluating motional features of the bound form through cross‐relaxation terms of protons at fixed distances on the herbicides. Contributions to longitudinal nonselective relaxation rates different from the proton–proton dipolar relaxation were inferred, most probably due to paramagnetic effects originating from the high‐spin nonheme FeII ion in the reaction center. Paramagnetic contributions to proton relaxation rates were converted into distance constraints in order to build a model for the interaction. The models place paraquat in the QB site, where most herbicides interact, in agreement with docking calculations, whereas acifluorfen was placed between the metal and the QB site, as also demonstrated by the induced paramagnetic shifts. Acifluorfen could therefore act to break the electron‐transfer pathway between the QA and QB sites.
Binding Mode of TMC‐95A Analogues to Eukaryotic 20S Proteasome
Authors: Kaiser Markus , Groll Michael , Siciliano Carlo , Assfalg‐Machleidt Irmgard , Weyher Elisabeth , Kohno Jun , Milbradt Alexander G. , Renner Christian , Huber Robert , Moroder Luis 
Published: September 2004

AbstractThe complex thermodynamics that govern noncovalent protein–ligand interactions are still not fully understood, despite the exponential increase in experimental structural data available from X‐ray crystallography and NMR spectroscopy. The eukaryotic 20S proteasome offers an ideal system for such studies as it contains in duplicate three proteolytically active sites with different substrate specificities. The natural product TMC‐95A inhibits these proteolytic centers noncovalently with distinct affinities. X‐ray crystallographic analysis of the complexes of the yeast proteasome core particle with this natural inhibitor and two synthetic analogues clearly revealed highly homologous hydrogen‐bonding networks involving mainly the peptide backbone despite the strongly differentiated binding affinities to the three active sites of the 20S proteasome. The natural product and the two analogues are constrained in a rigid β‐type extended conformation by the endocyclic biaryl clamp, which preorganizes the peptide backbone for optimal adaptation of the ligands to the active site clefts and thus favors the binding processes entropically. However, the biaryl clamp also dictates the orientation of the P1 and P3 residues and their mode of interaction with the protein binding subsites. This limitation is optimally solved in TMC‐95A with the conformationally restricted (Z)‐prop‐1‐enyl group acting as P1 residue, at least for the chymotrypsin‐like active site; however, it critically affects the inhibitory potencies of the analogues, thus suggesting the use of less‐rigid endocyclic clamps in the design of proteasome inhibitors that allow for a better presentation of residues interacting with the active site clefts of the enzyme.
Nanoparticles: Scaffolds for Molecular Recognition
Authors: Drechsler Ulf , Erdogan Belma , Rotello Vincent M. 
Published: September 2004

AbstractMonolayer and mixed‐monolayer protected clusters (MPCs and MMPCs) have great potential to combine molecular functionality with the intrinsic properties of nanometer‐sized scaffolds. This synergy can be used to create complex functional devices, including redox‐active, electronic, or magnetic storage devices, solution‐based sensors, and highly efficient catalysts. This review outlines some of the recent developments in nanoscale receptors based on synthetic and nonbiological recognition elements. In these nanoparticle systems, molecular recognition is achieved by covalent attachment of receptors on the nanoparticles coupled with noncovalent interactions to target substrates. Synthetic host–guest systems, hydrogen bonding, change in redox states, π–π stacking, rotaxane formation, and ion recognition are the main topics covered in this review.
Helical Structures of Conjugate Polymers Created by Oxidative Polymerization Using Synthetic Lipid Assemblies as Templates
Authors: Hatano Tsukasa , Bae Ah‐Hyun , Takeuchi Masayuki , Fujita Norifumi , Kaneko Kenji , Ihara Hirotaka , Takafuji Makoto , Shinkai Seiji 
Published: September 2004

AbstractThe morphology of conjugate polymers (such as poly(ethylenedioxythiophene), poly(pyrrole), and poly(aniline)) can be controlled in their polymerization processes, by applying the concept of the templating method to oxidative polymerization. As oxidative polymerization of these monomers produces cationic intermediates, the anionic assemblies can act as potential templates due to the mutual electrostatic attractive force. Oxidative polymerization of ethylenedioxythiophene (EDOT), pyrrole, and aniline was carried out using helical superstructures of synthetic lipid assemblies as templates. Interestingly, we have found that oxidative polymerization of these monomers results in novel polymeric aggregates, such as a helical‐tape structure and an intertwined helical structure, and that both the right‐handed and left‐handed helical structures can be created by a change in the hydrophilic head groups. This is the first example of helical superstructures composed of conjugate polymers that have been designed utilizing a convenient templating method.
Towards a Total Synthesis of the New Anticancer Agent Mensacarcin: Synthesis of the Carbocyclic Core
Authors: Tietze Lutz F. , Stewart Scott G. , Polomska Marta E. , Modi Andrea , Zeeck Axel 
Published: September 2004

AbstractA synthesis of the carbocyclic core associated with the new anticancer agent mensacarcin (1) is reported. The strategy involves the synthesis of several novel highly substituted aromatic compounds, such as 12 and 23. The lithium derivative of 12 readily engages in a nucleophilic addition to benzaldehyde 4 to provide the diphenylcarbinol rac‐15. The analogous benzyl ether rac‐16 undergoes an intramolecular Heck reaction to provide the required tetrahydroanthracene rac‐17, which can be transformed into the key tricyclic methyl ether rac‐20. In a second approach, the lithium derivative of 21 is added to the hexasubstituted benzaldehyde 23 to give the diphenylcarbinol rac‐35. Subsequent methylation to rac‐36 followed by an intramolecular Heck reaction provides tricycle rac‐37. Similarly, the oxidised compound 40 provides an electronically more suitable intramolecular Heck partner to afford compound 41. Further transformations of these substrates leads to rac‐43, which incorporates the core structure of mensacarcin (1).
Coordination Behavior of Oxide Ions in Inorganic Solids. Part 4. Synthesis, Crystal Structures, and Spectroscopic Characterization of NiP4O11 and CaNiP2O7.
Authors: Funke M. , Blum M. , Glaum R. , El Bali B. 
Published: September 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ring‐Fluorinated Naphthalene and Indene Synthesis via 6‐ and 5‐endo‐trig Cyclizations of gem‐Difluoroalkenes by Carbon Nucleophiles.
Authors: Ichikawa Junji , Miyazaki Hiroyuki , Sakoda Kotaro , Wada Yukinori 
Published: September 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ruthenium‐Catalyzed Cyclization of Epoxide with a Tethered Alkyne: Formation of Ketene Intermediates via Oxygen Transfer from Epoxides to Terminal Alkynes.
Authors: Madhushaw Reniguntala J. , Lin Ming‐Yuan , Sohel Shariar Md. Abu , Liu Rai‐Shung 
Published: September 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Orally Bioavailable Small Molecule Ketoamide‐Based Inhibitors of Cathepsin K
Authors: Barrett David G. , Catalano John G. , Deaton David N. , Long Stacey T. , Miller Larry R. , Tavares Francis X. , Wells‐Knecht Kevin J. , Wright Lois L. , Zhou Hui‐Qiang Q. 
Published: September 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.