bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecularly Imprinted Polymers via High‐Throughput and Combinatorial Techniques
Authors: Lanza Francesca , Sellergren Börje 
Published: February 2004

AbstractSummary: Techniques allowing high‐throughput synthesis and evaluation of molecularly imprinted polymer sorbents at a reduced scale (mini‐MIPs) have been developed and used for the optimisation of MIPs for recognition of target molecules in various environments. The most recent technique incorporates a liquid‐handling robot for the rapid dispensing of monomers, templates, solvents and initiator into the reaction vessels of a 96‐well plate. A library of 96 polymers, each of about 50 mg, can thus be prepared within 24 hours and the binding properties assessed within one to two weeks by quantification of nonbound fractions in parallel. Examples of how mini‐MIPs have been used as a tool to find superior MIPs for various targets (e.g. hydantoins, dihydropyridines, pteridines, triazines, drug lead compounds) and how to optimise them for particular matrices will be given. Applications of the resulting materials encompass selective solid‐phase extraction for quantitative analysis, chemical sensors, sorbents for preparative separations, screening tools in drug discovery and enzyme‐like catalysis.Semiautomated high‐throughput procedure for the synthesis of mini‐MIP libraries in microtiter plate format and evaluation of the library via serial (HPLC) or parallel (multifunctional plate reader) techniques.magnified imageSemiautomated high‐throughput procedure for the synthesis of mini‐MIP libraries in microtiter plate format and evaluation of the library via serial (HPLC) or parallel (multifunctional plate reader) techniques.
Combinatorial Growth and Analysis of the Transparent Conducting Oxide ZnO/In (IZO)
Authors: Taylor Matthew P. , Readey Dennis W. , Teplin Charles W. , van Hest Maikel F. A. M. , Alleman Jeff L. , Dabney Matthew S. , Gedvilas Lynn M. , Keyes Brian M. , To Bobby , Parilla Philip A. , Perkins John D. , Ginley David S. 
Published: February 2004

AbstractSummary: Compositionally graded, combinatorial libraries of indium‐doped zinc oxide (IZO) were grown by DC‐magnetron sputtering on glass at 100 °C. The In content ranged from 5 to 50 cation‐%. The highest conductivity, σ = 2 000 Ω−1 · cm−1 with μ = 25 cm2 · V−1 · s−1, was found at ≈50% In content with a visible transmittance greater than 80%. The (00l) layer spacing increased from ≈2.6 to 2.85 Å as the In content increased from 5 to 50%.Conductivity as a function of indium content for the three In‐Zn‐O transparent conducting oxide libraries studied here.magnified imageConductivity as a function of indium content for the three In‐Zn‐O transparent conducting oxide libraries studied here.
The Effect of Temperature on the Living Cationic Polymerization of 2‐Phenyl‐2‐oxazoline Explored Utilizing an Automated Synthesizer
Authors: Hoogenboom Richard , Fijten Martin W. M. , Schubert Ulrich S. 
Published: February 2004

AbstractSummary: The temperature dependency of the polymerization of 2‐phenyl‐2‐oxazoline was investigated utilizing a commercially available automated synthesizer equipped with individually heatable reactors. Kinetic investigations resulted in an optimal polymerization temperature and activation energy determination for the polymerizations initiated with methyl tosylate. Moreover, the in situ generation of benzyl iodide (more reactive initiator) from benzyl chloride and sodium iodide is described, whereby solid sodium iodide was automatically dosed into the reactors.magnified image
High‐Throughput Evaluation of the Wettability of Polymer Libraries
Authors: Thaburet Jean‐François , Mizomoto Hitoshi , Bradley Mark 
Published: February 2004

AbstractA high‐throughput method for assessing the wettability of polymer libraries has been developed. Droplets of water are dispensed by a liquid handler onto polymer films, and a digital camera mounted on the robotic arm records the spread of the droplets. The surface area of the droplet (related to the contact angle) was measured by image processing software. This method is fully automated and allows rapid wettability measurements of polymer libraries to be obtained.Automated system for spreading area measurement of water droplets on polymer films.magnified imageAutomated system for spreading area measurement of water droplets on polymer films.
Combinatorial Investigation of the Vapor Deposition Polymerization of Aromatic Polyimides
Authors: Bäte Markus , Neuber Christian , Giesa Reiner , Schmidt Hans‐Werner 
Published: February 2004

AbstractSummary: A combinatorial study on the synthesis and in situ orientation of polyimide thin films by vapor deposition polymerization was carried out. The combinatorial libraries consisted of sectors with different thicknesses, compositions, and with or without alignment layers. Monomers were selected to prepare rigid rodlike polyimides and to optimize their orientation during deposition and the imidization process. Vapor deposition of the monomers was performed sequentially or by coevaporation. By using this combinatorial approach the polymerization and the orientation behavior can be simultaneously studied and optimized by variation of film thickness, film composition, and deposition sequence.The combinatorial substrate for sequential evaporation consists of sectors with three PTFE alignment layers (rows B, C, and E) on quartz glass for UV/Vis measurements.magnified imageThe combinatorial substrate for sequential evaporation consists of sectors with three PTFE alignment layers (rows B, C, and E) on quartz glass for UV/Vis measurements.
Materials Screening and Combinatorial Development of Thin Film Multilayer Electro‐Optical Devices
Authors: Thelakkat Mukundan , Schmitz Christoph , Neuber Christian , Schmidt Hans‐Werner 
Published: February 2004

AbstractSummary: Rapid materials screening and combinatorial development of thin film multilayer electro‐optical devices is essential for fast research and development progress and the implementation of device structures into commercial products. A well‐established and reliable film preparation technique within the required nanometer film thickness range is vapor deposition. The combinatorial approach underlying this feature article is based on the preparation of linear or step gradient and the preparation of sectors of material combinations or device structures by using mask movements in combination with a rotation of the substrate. Both of the two principles are combined to obtain an infinite number of possible libraries with different complexity, which may differ in each sector by the layer thickness, the sequence of layers, and the material selection. In addition by simultaneous evaporation using two or more sources and varying the deposition rate, material compositions can also be created. In this feature article we review our work on combinatorial material screening and combinatorial optimization of multilayer thin film organic electro‐optical devices prepared by vapor deposition. This article covers results on organic light emitting devices (OLEDs), organic solar cells, the orientation behavior of formanisotropic functional molecules on alignment layers and the in situ preparation and orientation of rodlike and thermally stable aromatic polyimides.Example of a combinatorial vapor deposition technique, which is a powerful tool to screen efficiently new materials and configurations in thin film multilayer electro‐optical devices.magnified imageExample of a combinatorial vapor deposition technique, which is a powerful tool to screen efficiently new materials and configurations in thin film multilayer electro‐optical devices.
Individual quality of life of patients undergoing autologous peripheral blood stem cell transplantation
Authors: Frick E. , Borasio G.D. , Zehentner H. , Fischer N. , Bumeder I. 
Published: February 2004

AbstractBackground. Most quality‐of‐life (QoL) studies in autologous Peripheral Blood Stem Cell Transplantation (PBSCT) are descriptive and concentrate on symptom severity and functional deficits. The aim of this study is to compare individual QoL (iQoL) with health‐related QoL (hrQoL) and functional status of patients before high‐dosed therapy/PBSCT.Patients and methods. Multiple Myeloma, non‐Hodgkin's Lymphoma and other tumor patients were asked to complete the following measures before high‐dosed therapy/PBSCT: the European Organization for Research and Treatment of Cancer (EORTC) Quality‐of‐life Questionnaire Core 30 (QLQ–C30), and the Schedule for the Evaluation of Individual QoL—Direct Weighting (SEIQoL–DW), a patient‐generated instrument which allows the patients to nominate the five most important domains (cues) for their present QoL. The SEIQoL‐DW assessment generates: (1) a global QoL score (SEIQoL‐INDEX), calculated as Σ(levels×weights); (2) the current overall QoL, rated on a visual analogue scale (VAS). Additional measures included demographic data, clinical disease status of remission and Karnofsky's index.Results. Seventy‐nine patients completed both types of questionnaires. The QoL domains nominated by the patients were assigned to groups (aggregated cues), the most frequent of which were family (89%), hobbies/pastimes (74%), health (physical, including mobility) (70%), profession/occupation (51%), social life/friends (47%) and marriage/partnership (33%). There was no correlation between the SEIQoL‐DW total scores and the EORTC QLQ‐C30 scale or the Karnofsky index.Conclusion. Individual QoL as assessed by the SEIQoL–DW is unrelated to standard health‐status measures such as the EORTC QLQ‐C30 or the Karnofsky index. Patient‐perceived iQoL in PBSCT seems to depend largely on areas others than health and physical functioning, with the family playing a prominent role. Copyright © 2003 John Wiley & Sons, Ltd.
First principles study of the structure, electronic state, and stability of CmN2 clusters
Authors: Jiang Zhen‐Yi , Xu Xiao‐Hong , Wu Hai‐Shun , Zhang Fu‐Qiang , Jin Zhi‐Hao 
Published: February 2004

AbstractGeometric and electronic properties of CmN2 (m = 1–14) clusters have been investigated by density functional theory using the hybrid B3LYP functional and the 6‐311G(d) basis set. Harmonic frequencies for these clusters are given to aid in the characterization of the ground states. These results show that CmN2 (m = 1–14) clusters form linear structures with D∞h symmetry. Two N atoms favor to bond at ends in linear isomers. The chains with odd m have triplet ground states whereas the ones with even m have singlet ground states. The calculated HOMO–LUMO gaps and ionization potentials all show that the CmN2 (m = 1–14) clusters with even m are more stable than those with odd m, which is consistent with the observed even–odd alternation of the time‐of‐flight signal intensities. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Determination of Abacavir in maternal plasma, amniotic fluid, fetal and placental tissues by a polarity switching liquid chromatography/tandem mass spectrometry method
Authors: Clark T. Nicole , White Catherine A. , Bartlett Michael G. 
Published: February 2004

AbstractA rapid and efficient high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) method for the determination of concentrations of the carbocyclic nucleoside antiviral Abacavir in maternal rat plasma, amniotic fluid, placental and fetal tissue samples has been developed and validated. All tissue samples were homogenized in water prior to analysis and all samples were prepared by acetonitrile precipitation followed by dilution with HPLC‐grade water. Separation of the analyte and internal standard from the matrices was achieved on a C8 analytical column (2.1 × 150 mm, 5 μm particle size). The mobile phase consisted of 10 mM ammonium acetate/acetonitrile using a gradient method at a flow rate of 0.25 mL/min for all matrices. The method yields retention times of approximately 3.4 and 5.1 min for the internal standard (Azidouridine) and Abacavir, respectively. For all matrices the limit of detection was approximately 1 ng/ml. Recoveries from the different matrices ranged from 53–87% for Abacavir and from 69–84% for Azidouridine. Within‐ and between‐run precision (%RSD) and accuracy (%Error) were under 15% for all matrices. Copyright © 2004 John Wiley & Sons, Ltd.
Structural assignment of isomeric 2‐aminopyridine‐derivatized oligosaccharides using MSn spectral matching
Authors: Takegawa Yasuhiro , Ito Shinya , Yoshioka Shinji , Deguchi Kisaburo , Nakagawa Hiroaki , Monde Kenji , Nishimura Shin‐Ichiro 
Published: February 2004

AbstractTwo isomeric pairs of 2‐aminopyridine (PA)‐derivatized fucosylated and non‐fucosylated oligosaccharides (complex‐type N‐glycans of IgG) were analyzed using liquid chromatography/ion trap mass spectrometry (LC/ITMS) with a sonic spray ionization source and by varying the collision‐induced dissociation voltage. Reproducibility of MSn (n = 2) spectra obtained by LC/ITMS was tested considering both fragment ions (m/z) and intensities. A comparison of their MSn spectra and evaluation of similarities (or matching), based on correlation coefficients between MSn spectra, was investigated as a possibility for structural assignment of the isomers. It is shown that such MSn spectral matching is useful and applicable to the structural assignment of relatively large fucosylated and sialylated PA‐oligosaccharides released from IgG based on Bn‐ and Yn‐type fragmentations of the corresponding [M+H+Na]2+ ions. Copyright © 2004 John Wiley & Sons, Ltd.
Use of 13C to monitor soil organic matter transformations caused by a simulated forest fire
Authors: Fernandez Irene , Cabaneiro Ana , González‐Prieto Serafín J. 
Published: February 2004

AbstractSoil organic matter (SOM) transformations caused by heating were analyzed using the stable carbon isotope 13C as a tracer to follow C mineralization dynamics and C transfers between different organic compartments. A 13C‐labelled soil, obtained by incorporation of 13C‐enriched Lolium perenne phytomass into a pine forest soil, was heated for 10 min at 385°C to reproduce conditions typical of a forest fire and changes in total C content, potential C mineralization activity and C distribution between the different soil organic fractions were determined. Changes caused by heating on the potential soil C mineralization, determined by laboratory aerobic incubation, reveal alterations to the SOM biodegradability; some stabilized SOM showed an increase in biodegradability, whereas less stabilized SOM became more resistant to microorganisms. Chemical fractionations of SOM allowed us to monitor changes in its composition. As a consequence of heating, the less polymerized humic fractions were the most strongly affected, with the total disappearance of fulvic acids. A significant increase in the quantity and degree of polymerization of the humic acids at the expense of other more 13C‐enriched substances was also found. Finally, a large decrease in humin was observed, its solubilizable part disappearing completely, probably as a consequence of the incorporation of the byproducts into the free organic matter fraction. Copyright © 2004 John Wiley & Sons, Ltd.
New fragmentation mechanisms in matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight tandem mass spectrometry of carbohydrates
Authors: Spina Emanuela , Sturiale Luisa , Romeo Donatella , Impallomeni Giuseppe , Garozzo Domenico , Waidelich Dietmar , Glueckmann Matthias 
Published: February 2004

AbstractThe spectra recorded by matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight tandem mass spectrometry (MALDI‐TOF/TOF‐MS/MS) of complex carbohydrates from human milk are presented. Besides ions originating from glycosidic cleavages and from sugar ring fragmentations, these spectra show intense peaks that may be assigned to ions produced by three new fragmentation pathways involving a six‐atom rearrangement. These ions, together with the A fragments from sugar ring fragmentations, open the possibility of obtaining a complete mapping of the linkage positions present in the carbohydrates investigated by MALDI‐TOF/TOF. Copyright © 2004 John Wiley & Sons, Ltd.
Diagnostic ions for the rapid analysis by nano‐electrospray ionization quadrupole time‐of‐flight mass spectrometry ofO‐glycans from human mucins
Authors: Robbe Catherine , Capon Calliope , Coddeville Bernadette , Michalski Jean‐Claude 
Published: February 2004

AbstractNano‐electrospray ionization quadrupole time‐of‐flight mass spectrometry (nanoESI‐Q‐TOFMS) was used for sensitive mapping and sequencing of underivatized oligosaccharide alditols obtained from human mucins. Using subnanomolar amounts of oligosaccharides previously analyzed by nuclear magnetic resonance (NMR), series of diagnostic ions relevant to the structural characterization ofO‐glycans were deduced. Determination of the core type as well as positions and partial linkages of fucose residues could be readily obtained from the dominant [M+Na]+ions. Differentiation of isomeric structures and glycosidic linkages were defined by the characteristic cross‐ring0,2A‐type cleavages in the negative ion mode. Tandem (MS/MS) mass spectra of [MH]−ions from sialylated or sulfatedO‐glycans revealed information concerning the position and linkage of such residues. These fragmentation rules were further applied in the structural determination of glycans from human colonic mucins. All these findings indicated the efficiency of ESI‐Q‐TOFMS for the determination of oligosaccharide composition, sequence, partial linkage and substitution, providing a wealth of structural information with sensitivity sufficient for the analysis of quantities as obtained from natural sources. Copyright © 2004 John Wiley & Sons, Ltd.
Mass spectral fingerprints of detergents in gasolines using electrospray ionization
Authors: Carraze B. , Delafoy J. , Bertin J. , Beziau J.‐F. , Lange C. M. 
Published: February 2004

AbstractMass spectral fingerprints of detergents in Austrian, Hungarian, Uruguayan, and Chilean gasolines have been obtained using electrospray ionization mass spectrometry. Polymers or copolymers were observed based on ether motifs (inter‐peak spacings of 44, 58 and 72 u) in all samples. Austrian gasoline was found to also contain polymers based on isobutene‐amine. Copyright © 2004 John Wiley & Sons, Ltd.
In vitro metabolism of ethoxidine by human CYP1A1 and rat microsomes: identification of metabolites by high‐performance liquid chromatography combined with electrospray tandem mass spectrometry and accurate mass measurements by time‐of‐flight mass spectrometry
Authors: Deroussent Alain , Ré Micheline , Hoellinger Henri , Vanquelef Enguerran , Duval Olivier , Sonnier Michèle , Cresteil Thierry 
Published: February 2004

AbstractEthoxidine (N‐methyl‐12‐ethoxy‐2,3,8,9‐tetramethoxybenzo[c]phenanthridinium methylsulfonate salt) is a synthetic 2‐methoxy‐12‐ethoxy derivative of the natural alkaloid fagaronine. This new inhibitor of DNA‐topoisomerase I is considered as a potential antitumor agent with higher in vitro activity than fagaronine. In order to further improve the efficiency of ethoxidine, its in vitro biotransformation by hepatic monooxygenases and the structures of its metabolites were investigated by high‐performance liquid chromatography (HPLC) combined with electrospray ionization tandem mass spectrometry (ESI‐MS/MS) and accurate mass measurement by time‐of‐flight mass spectrometry (TOFMS). When ethoxidine was incubated with BNF‐treated rat liver microsomes or with cells expressing different recombinant human cytochrome P450, the same four ethoxidine metabolites (m1–m4) were detected and were formed exclusively by CYP1A1. The structures of these metabolites were assigned from ESI‐MS/MS mass spectra and compared with those of ethoxidine derivatives. Accurate mass measurements of in‐source ESI‐TOFMS fragment ions exhibited successive neutral losses of C2H4 and CO for ethoxidine and its metabolites. Whereas a 15 Da loss (methyl radical) was observed for the metabolites m1–m4 containing a quaternary ammonium group, a 16 Da loss (methane) was observed for ethoxidine and could have resulted from the presence of two methoxy groups at adjacent positions (C‐2 and C‐3). The proposed oxidative modifications of ethoxidine were further confirmed by determination of the number of exchangeable hydrogen atoms and by the proposed elemental compositions of the metabolites based on accurate mass measurements by TOFMS. Two major metabolites resulted from O‐demethylation of ethoxidine; one was tentatively identified as 12‐ethoxyfagaronine (m3) and the second as an O‐demethylated ethoxidine isomer (m4). Two polar metabolites were shown to be O‐demethylated (m1) and hydroxylated (m2) derivatives of 12‐ethoxyfagaronine. When 12‐ethoxyfagaronine was incubated under the same conditions as ethoxidine, m2 was formed, thus supporting the proposal that 12‐ethoxyfagaronine is the primary oxidative product of ethoxidine. Copyright © 2004 John Wiley & Sons, Ltd.
Quantitation of human glutathione S‐transferases in complex matrices by liquid chromatography/tandem mass spectrometry with signature peptides
Authors: Zhang Fagen , Bartels Michael J. , Stott William T. 
Published: February 2004

AbstractDirect quantitation of glutathione S‐transferase (GST) isoforms [α (GST‐A) and μ (GST‐M)] in human liver cytosol was achieved by liquid chromatography/tandem mass spectrometry (LC/ESI‐MS/MS) analysis of signature peptides of GST‐A and GST‐M and their corresponding stable isotopic peptide internal standards via multiple reaction monitoring (MRM). The selection of signature peptides was performed via trypsin digestion of commercially available cDNA‐expressed GST‐A1 and GST‐M1, followed by LC/ESI‐MS/MS with an ion trap mass spectrometer and sequencing with the TurboSEQUEST® application. Quantitative analysis of the selected signature peptides in the multi‐reaction monitoring (MRM) mode was performed using a triple‐quadruple mass spectrometer. A series of human cytosol samples was quantitatively analyzed for levels of GST‐A and GST‐M. The total level of GST‐A and GST‐M obtained from this LC/ESI‐MS/MS method was well correlated with the total level of GST determined by the 1‐chloro‐2,4‐dinitrobenzene (CDNB) method. Copyright © 2004 John Wiley & Sons, Ltd.
Comparison of analyses of urinary 8‐hydroxy‐2′‐deoxyguanosine by isotope‐dilution liquid chromatography with electrospray tandem mass spectrometry and by enzyme‐linked immunosorbent assay
Authors: Hu Chiung‐Wen , Wu Ming‐Tsang , Chao Mu‐Rong , Pan Chih‐Hong , Wang Chien‐Jen , Swenberg James A. , Wu Kuen‐Yuh 
Published: February 2004

AbstractA highly sensitive and selective method, using isotope‐dilution liquid chromatography with tandem mass spectrometry (LC/MS/MS), for quantification of urinary 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), an important biomarker of oxidative stress, was developed and compared with a method using an enzyme‐linked immunosorbent assay (ELISA). The synthesis of 15N5‐8‐OHdG is described. In this study, 140 urine samples were collected from workers in a coke oven plant, including samples from 49 control workers and 91 workers who had been occupationally exposed to polyaromatic hydrocarbons (PAHs). The major urinary metabolite of PAHs, 1‐hydroxypyrene (1‐OHP), was measured for the exposed workers. Results from the present study showed a significant correlation between these two measurements for determination of 8‐OHdG (p < 0.05, r2 = 0.70). However, only the LC/MS/MS measurements of urinary levels of 8‐OHdG showed a significant difference between the exposed and the control subjects (p < 0.05). The ELISA method failed to demonstrate this difference. Furthermore, only by using the LC/MS/MS method was a significant correlation observed between the urinary levels of 1‐OHP and 8‐OHdG. These findings suggest that a highly specific and sensitive analytical method such as isotope‐dilution LC/MS/MS is extremely important and necessary for accurate measurement and a comprehensive study of oxidative stress in human subjects. Copyright © 2004 John Wiley & Sons, Ltd.