bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Combinatorial Synthesis, Rapid Screening, and Computational Modeling in Biomaterials Development
Authors: Smith Jack R. , Seyda Agnieszka , Weber Norbert , Knight Doyle , Abramson Sascha , Kohn Joachim 
Published: February 2004

AbstractSummary: The advent of high‐throughput combinatorial synthesis techniques in drug discovery has stimulated efforts to apply these techniques to the discovery of biomaterials. To be of practical utility, combinatorial approaches to biomaterials design require (i) the availability of parallel synthesis techniques to generate libraries of polymers, (ii) efficient assays for the rapid characterization of biorelevant material properties, and (iii) computational methods to efficiently model different biological responses in the presence of polymers. Here we report the integration of these methodologies and illustrate the potential of this approach to accelerate the development of new biomaterials. The parallel synthesis of a library of 112 biodegradable polyarylates has been reported previously. This library was used to develop efficient screening techniques to determine biorelevant polymer properties (fibrinogen adsorption, gene expression in macrophages, growth of fetal rat lung fibroblasts (RLFs)). A Surrogate (semiempirical) Model was developed (i) to determine molecular‐scale polymer properties that correlate to various biological responses, and (ii) to predict fibrinogen adsorption and RLF growth on polymeric surfaces. For 38 out of 45 polymers, the model predicted the amount of fibrinogen adsorbed correctly within the error of the experimental measurements. The growth of rat lung fibroblasts was correctly predicted by the model for 41 out of 48 polymers. The correlation factor between the model's predicted values and the experimentally determined data was 0.54 ± 0.09 and 0.69 ± 0.12 for fibrinogen adsorption and RLF growth, respectively. The results presented here demonstrate the utility of combinatorial and computational approaches for the rational design of polymers for biomedical applications.Design of the library of polyarylates, which are copolymers of a diacid and a diphenol. Chemical diversity was created by variations in the structure of the diacid (marked as “Y”) and the pendent chain (marked as “R”).magnified imageDesign of the library of polyarylates, which are copolymers of a diacid and a diphenol. Chemical diversity was created by variations in the structure of the diacid (marked as “Y”) and the pendent chain (marked as “R”).
Multiparameter High Throughput Characterization of Combinatorial Chemical Microarrays of Chemosensitive Polymers
Authors: Mirsky Vladimir M. , Kulikov Valentin , Hao Qingli , Wolfbeis Otto S. 
Published: February 2004

AbstractSummary: High throughput characterization of combinatorial libraries demands a compromise between completeness of the study and reasonable investigation time. This compromise can be found by the development of test protocols consisting of the minimal number of the most informative measurements. Multiparameter high throughput characterization of sensitive materials is described. The parameters include response time, regeneration time, reversibility, reproducibility, sensitivity, linearity. The approach was applied for characterization of conductometric gas‐sensitive polymer materials.Chemical microarrays prepared by electrochemical synthesis of polymers on platinum electrodes.magnified imageChemical microarrays prepared by electrochemical synthesis of polymers on platinum electrodes.
Sensors in Combinatorial Polymer Research
Authors: Potyrailo Radislav A. 
Published: February 2004

AbstractSummary: This review highlights the broad potential of sensor technologies for combinatorial polymer research. Advances in components microfabrication, electronics, transducers, and data analysis in the area of sensors can stimulate the development of many more new concepts applicable for rapid polymer screening. These advances are already impacting on several phases in a typical combinatorial discovery cycle that include parallel synthesis of polymers, their performance testing, evaluation of properties, and processing of collected data. It is demonstrated that sensors provide an attractive addition to the infrastructure of the analytical instruments used for screening of intrinsic and performance polymer properties.Impact of sensor technologies on the combinatorial discovery cycle.magnified imageImpact of sensor technologies on the combinatorial discovery cycle.
The Codeposited Composition Spread Approach to High‐Throughput Discovery/Exploration of Inorganic Materials
Authors: van Dover Robert Bruce , Schneemeyer Lynn F. 
Published: February 2004

AbstractSummary: We discuss the high‐throughput materials discovery/exploration paradigm in the context of inorganic materials. We emphasize the codeposited continuous composition spread approach, contrasting it with layered composition spreads and the discrete combinatorial approach to synthesis. The results of specific investigations on dielectrics are discussed in detail. The use of inorganic materials in thin film form entails some general advantages and disadvantages that will be discussed. We also contrast the considerations involved in the screening/discovery of new materials vis‐à‐vis reliable characterization of the composition dependence of properties.Ternary plot of the relative dielectric constant in the ZrSnTiO system.magnified imageTernary plot of the relative dielectric constant in the ZrSnTiO system.
Gradient Polymer Layers by “Grafting To” Approach
Authors: Ionov Leonid , Zdyrko Bogdan , Sidorenko Alexander , Minko Sergiy , Klep Viktor , Luzinov Igor , Stamm Manfred 
Published: February 2004

AbstractA new method for the preparation of ultrathin tethered polymer layers with gradually changing thickness was developed utilizing the “grafting to” approach. The grafting procedure allowed translation of the temperature gradient created in a heating stage into a gradient of polymer chain grafting density. The gradient tethered polymer layers demonstrated gradual changes in wetting properties and morphology transition from pinned micelles to a brush regime along the substrate.Preparation of ultrathin tethered polymer layers with gradually changing thickness by utilizing a “grafting to” approach using a temperature gradient created on a heating stage.magnified imagePreparation of ultrathin tethered polymer layers with gradually changing thickness by utilizing a “grafting to” approach using a temperature gradient created on a heating stage.
High‐Throughput Investigation of Polymerization Kinetics by Online Monitoring of GPC and GC
Authors: Hoogenboom Richard , Fijten Martin W. M. , Abeln Caroline H. , Schubert Ulrich S. 
Published: February 2004

AbstractSummary: Gel permeation chromatography (GPC) and gas chromatography (GC) were successfully introduced into a high‐throughput workflow. The feasibility and limitations of online GPC with a high‐speed column was evaluated by measuring polystyrene standards and comparison of the results with regular offline GPC measurements. The reliability of the online GC characterization was investigated by monitoring the cationic ring‐opening‐polymerization of 2‐ethyl‐2‐oxazoline, whose polymerization kinetics were determined by both online and offline GC.
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A High‐Throughput Approach towards Tailor‐Made Water‐Soluble Metallo‐Supramolecular Polymers
Authors: Schmatloch Stefan , van den Berg Antje M. J. , Fijten Martin W. M. , Schubert Ulrich. S. 
Published: February 2004

AbstractSummary: Automated parallel synthesis and high‐throughput screening has been proven to drastically speed up polymer and materials research. Here we present an automated parallel approach for investigation of the influences of different counter ions (chloride, bromide, acetate and sulfate) on the iron(II) mediated metallo‐supramolecular polymerization of bis(2,2′:6′,2″‐terpyrid‐4′‐yl)‐poly(ethylene oxide)179. The synthesized polymers were characterized by 1H NMR, UV‐vis and IR. The degree of polymerization has been estimated on the basis of concentration dependent viscosity measurements. The conversion as well as the degree of polymerization followed the order: bromide, chloride > sulfate ≫ acetate.magnified image
Combinatorial Pulsed Laser Deposition of Pentacene Films for Field Effect Devices
Authors: Yamaguchi Jun , Itaka Kenji , Hayakawa Tomohiro , Arai Keiichiro , Yamashiro Mitsugu , Yaginuma Seiichiro , Koinuma Hideomi 
Published: February 2004

AbstractSummary:Combinatorial pulsed laser deposition (PLD) technique has been applied to the fabrication of pentacene thin films for field effect devices. The pentacene films were fabricated by PLD with the Nd:YAG laser wavelength, fluence and the substrate temperature as combinatorial parameters. From the IR and UV‐vis absorption spectra and electrical properties of the films, the laser wavelength and fluence have been elucidated to be factors dominating the properties of the film.Schematic diagram of a combinatorial pulsed laser deposition (PLD) system.magnified imageSchematic diagram of a combinatorial pulsed laser deposition (PLD) system.
Scattering Measurements for High Throughput Materials Science Research
Authors: Norman Alexander I. , Cabral João T. , Karim Alamgir , Amis Eric J. 
Published: February 2004

AbstractSummary: We present a high throughput X‐ray scattering study (SAXS/WAXS) of the formation and stability of the vesicle phase of a water soluble diblock copolymer. The vesicle shape and shell thickness were investigated as a function of block copolymer concentration and temperature. We were able to establish a growth in the SAXS peak as concentration increased, indicating a greater polymer concentration of vesicles. The effect of temperature was also investigated.Library sample of a discrete concentration gradient of EO(6)BO(11) in water.magnified imageLibrary sample of a discrete concentration gradient of EO(6)BO(11) in water.
Cover Picture: Macromol. Rapid Commun. 1/2004
Authors: Meier Michael A. R. , Hoogenboom Richard , Schubert Ulrich S. 
Published: February 2004

Cover: A general workflow for combinatorial and high‐throughput polymer research, with examples, is shown. The cycle starts with the design of experiments (DoE), followed by automated polymer synthesis, high‐throughput screening, library preparation (thin films, dots and gradient libraries), property investigations and finally data mining. The background depicts polymer MALDI‐TOF MS data obtained during high‐throughput screening.Details can be found in the Review by M. A. R. Meier, R. Hoogenboom, and U. S. Schubert* on page 21.
Theoretical study of beryllium (II) complexes using CATIVIC: New parametric method
Authors: Martínez Ramón , Brito Felipe , Araujo Mary Lorena , Ruette Fernando , Sierraalta Aníbal 
Published: February 2004

AbstractCalculations of several beryllium complexes {[Be(H2O)n]2+(n= 1–4), [BeOH(H2O)n]+(n= 1–3), and [Be(OH)2(H2O)n] (n= 1, 2)} were carried out to compare different ab initio (density functional theory, MP2) and parametric (PM3(tm), CATIVIC) methods. Results show that the parametric method CATIVIC gives geometries and energies closer to the ab initio geometries than the PM3(tm) method due to the inclusion of the atomic excitation energies of the neutral atoms as well as the ions and to the dependence of the molecular parameters on the system charge. The molecular electronic density analysis of the BeO bonds shows that the Be–water interaction in the [Be(H2O)n]2+complexes can be considered as a closed‐shell interaction with a σ character in the bond while in the [Be(OH)2(H2O)n] complexes the Bewater bond have π character. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Study of the formamide–methanol dimer with ab initio and density functional theory methods
Authors: Fu Aiping , Du Dongmei , Zhou Zhengyu 
Published: February 2004

AbstractFor the first time, the structures and energies for the hydrogen bonding of a 1:1 complex formed between formamide and methanol molecules have been computed with various pure and hybrid density functional theory (DFT) and ab initio methods at varied basis set levels from 6‐31g to 6‐31+g(d,p). Five reasonable geometries on the potential energy surface of methanol and formamide system are considered and their relative stability is discussed. The infrared (IR) spectrum frequencies, IR intensities, and vibrational frequency shifts are reported. From the systematic studies, it is found that all the DFT methods selected here correctly compute the dimerization energies and geometries, with the B3P86 method predicting the hydrogen bond lengths relatively shorter and BPW91 yielding the interaction energies relatively lower. Finally, the solvent effects on the geometries of the formamide–methanol complexes have also been investigated using self‐consistent reaction field (SCRF) calculations with five different DFT methods at the 6‐31+g(d,p) basis set level. The results indicate that the polarity of the solvent has played an important role on the structures and relative stabilities of different isomers. Moreover, the basis set superposition error correction is critical to the interaction energies in the polar solvents. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Ab initio structural study of some substituted ibuprofen derivatives as possible anti‐inflammatory agents
Authors: Villa M. , Bounaim L. , Smeyers N. , Senent M. L. , Ezamarty A. , Smeyers Y. G. 
Published: February 2004

AbstractThe formation energies of a series of substituted derivatives in α‐position of ibuprofen (2‐p‐isobutyl‐phenyl‐propionic acid) are determined, at the ab initio level RHF/6‐311G** with full geometry optimization, in their neutral and anionic forms and in the gas phase and water solution to correlate their physical–chemical properties with their anti‐inflammatory activity. Conformational calculations on the acidic moiety were also performed on five of them. The ab initio methods foresee that all these molecules present two preferred conformations in which the substituting atom in α‐position is lying approximately in the aromatic ring plane, in contrast with the results obtained with semiempirical methods. In this article, the protonation energy in solution, the solvation energy, the HOMO energy of the neutral form, and the lipophilicity will be considered as possible factors of anti‐inflammatory activity. The protonation energy in solution, together with the lipophilicity, are verified to be good activity factors: The smaller the protonation energy and the lipophilicity, the larger the anti‐inflammatory activity. In contrast, the larger the solvation energy, the smaller the activity. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Common generating functions of complete harmonic oscillator wave functions and transformation brackets in D dimensions
Authors: Chaos‐Cador L. , Ley‐Koo E. 
Published: February 2004

AbstractThe separability of the Schrödinger equation for harmonic oscillators in D dimensions and in different coordinate systems (Cartesian, circular, spherical) makes possible the construction of common generating functions for the complete harmonic oscillator wave functions in the corresponding dimensions and coordinates. Explicit forms of such generating functions and their series expansions are presented, and one of their applications is illustrated through the evaluation of transformation brackets. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Orthogonal time‐of‐flight secondary ion mass spectrometric analysis of peptides using large gold clusters as primary ions
Authors: Tempez Agnès , Schultz J. A. , Della‐Negra S. , Depauw J. , Jacquet D. , Novikov A. , Lebeyec Y. , Pautrat M. , Caroff M. , Ugarov M. , Bensaoula H. , Gonin M. , Fuhrer K. , Woods Amina 
Published: February 2004

AbstractSecondary ion mass spectrometry (SIMS) for biomolecular analysis is greatly enhanced by the instrumental combination of orthogonal extraction time‐of‐flight mass spectrometry with massive gold cluster primary ion bombardment. Precursor peptide molecular ion yield enhancements of 1000, and signal‐to‐noise improvements of up to 20, were measured by comparing SIMS spectra obtained using Au+ and massive Au4004+ cluster primary ion bombardment of neat films of the neuropeptide fragment dynorphin 1–7. Remarkably low damage cross‐sections were also measured from dynorphin 1–7 and gramicidin S during prolonged bombardment with 40 keV Au4004+. For gramicidin S, the molecular ion yield increases slightly as a function of Au4004+ beam fluence up to at least 2 × 1013 Au4004+/cm2. This is in marked contrast to the rapid decrease observed when bombarding with ions such as Au5+ and Au9+. When gramicidin S is impinged with Au5+, the molecular ion yield decreases by a factor of 10 after a fluence of only 8 × 1012 ions/cm2. Comparison of these damage cross‐sections implies that minimal surface damage occurs during prolonged Au4004+ bombardment. Several practical analytical implications are drawn from these observations. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of uranium and isotopic ratio measurement in fish and marine invertebrates from the North Adriatic Sea by inductively coupled plasma mass spectrometry
Authors: Bettinelli Maurizio , Spezia Sandro , Minoia Claudio 
Published: February 2004

AbstractUranium analysis in fish, echinoderms and shellfish samples collected in the north part of the Adriatic Sea is presented. The aim of the work was to evaluate uranium concentrations in samples of this kind, and also to investigate possible contamination from depleted uranium (DU) in consequence of the war operations previously conducted in that area. DU contamination was checked by measuring the 235U/238U isotope ratio. The samples were dissolved according to the EPA 3052 procedure, and the determinations were performed by inductively coupled plasma mass spectrometry (ICP‐MS), optimized in order to perform isotope ratio measurements with good precision. The method was validated by evaluating the recovery from spiked samples; results in the range 93–107% were obtained. The isotope ratio measurement was evaluated in terms of accuracy and precision by analyzing the certified reference materials IAEA 326 and GBW 07305, and good agreement with the certified values was obtained here also. The concentration of uranium was higher in invertebrate samples than in fish (0.3–2 μg/g of U vs. 0.05–0.1 μg/g, respectively). The isotope ratio measurements for all the samples gave values very similar to the natural ratio, permitting exclusion of the presence of DU. Copyright © 2004 John Wiley & Sons, Ltd.
An isotopic dilution approach for 1,3‐butadiene tailpipe emissions and ambient air monitoring
Authors: Riservato Manuela , Rolla Antonio , Davoli Enrico 
Published: February 2004

AbstractAn isotopic dilution approach for 1,3‐butadiene analysis in gaseous samples is presented. The methodology is based on active sampling on sorbent tubes and subsequent analysis by thermal desorption into a gas chromatography/mass spectrometry system. By adding a perdeuterated internal standard onto the sorbent tubes before sampling, and using mass spectrometric detection, the methodology gives high accuracy for this unstable analyte. The method has been used to monitor 1,3‐butadiene ambient air concentrations in a residential area in proximity to a heavy‐traffic roadway over a one‐week period, for comparison with other traffic‐related pollutants analysed by standard procedures. It has also been used to determine tailpipe emissions of two vehicles by standard emission testing procedures in a dynamometer. These vehicles were chosen as examples of low‐ and high‐end emission rate vehicles, i.e., an old no‐catalytic converter Otto engine and a new direct‐injection diesel engine with catalytic converter. Exhaust gas emissions were 0.052 and 35.85 mg/km, reflecting differences in fuel, engine design, age, and presence (or not) of a catalytic abatement system. The ambient air results showed a weekly average concentration of 1,3‐butadiene of 0.53 μg/m3. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous analytical method for the determination of TCH346 and its four metabolites in human plasma by liquid chromatography/tandem mass spectrometry
Authors: Hara Hisanori , Uchimura Takashi , Akashi Naotsugu , Naganuma Tomoyoshi , Aizawa Tetsushi , Nagae Yusuke , Masuda Naoki 
Published: February 2004

AbstractTCH346 (dibenzo[b,f]oxepin‐10‐ylmethyl‐prop‐2‐ynylamine) is a novel propargylamine compound under investigation as a putative agent in the treatment of chronic neurodegenerative illnesses. To support clinical studies an analytical method was developed for TCH346 plus its three amine metabolites and a carboxylic acid metabolite in human plasma. Using a two‐step liquid‐liquid extraction, one under acidic and one under basic conditions, by pH‐switching both the basic and acidic analytes were extracted from 0.5 mL of plasma. All these basic and acidic compounds could be analyzed simultaneously using gradient high‐performance liquid chromatographic (HPLC) separation with positive/negative selected reaction monitoring mass spectrometry. As a result of the validation study, the analytical method was shown to be appropriate for the determination of TCH346 and its metabolites CGP70861, GP42120, CGP71090, and GP54840 in plasma for forthcoming clinical studies. The LLOQs were set to 2, 200, 20, 20, and 200 pg/mL for TCH346, CGP70861, GP42120, CGP71090, and GP54840, respectively, and the ULOQ for all analytes was 20 000 pg/mL. All analytes were stable in 50% MeOH at 4°C for at least one year, in human plasma stored below −70°C for at least 7 months, in human plasma below −18°C for at least 6 months, in human plasma at room temperature for at least 1 day, and in the final extract solution at 4°C for at least 3 days. Copyright © 2004 John Wiley & Sons, Ltd.
Liquid chromatography/time‐of‐flight mass spectrometric analyses for the elucidation of the photodegradation products of triclosan in wastewater samples
Authors: Ferrer Imma , Mezcua Milagros , Gómez M. José , Thurman E. Michael , Agüera Ana , Hernando M. Dolores , Fernández‐Alba Amadeo R. 
Published: February 2004

AbstractLiquid chromatography coupled with time‐of‐flight mass spectrometry (LC/TOFMS) was applied for the identification of four new photodegradation products of triclosan, a major antimicrobial agent used in personal care products. Wastewater samples, spiked at 7 μg/mL with triclosan, were irradiated with natural sunlight in order to generate the photodegradation products. Aliquots of the spiked water samples were taken at different times of irradiation and compounds were isolated from the water samples by solid‐phase extraction. Separation and detection of the compounds and degradation products were accomplished by LC/TOFMS, which provided highly selective information about elemental compositions. Accurate mass measurements for the four degradation products permitted postulation of proposed empirical formulae in this study. Replacement of chlorine atoms by hydroxyl groups and chlorine losses are the major degradation pathways proposed. The degradation products were formed also under environmental conditions in wastewater matrices, thus suggesting their presence in real wastewater treatment processes. Copyright © 2004 John Wiley & Sons, Ltd.