bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Guideline to the Design of Molecular‐Based Materials with Long‐Lived Photomagnetic Lifetimes
Authors: Letard Jean‐Francois , Guionneau Philippe , Nguyen Olivier , Costa Jose Sanchez , Marcen Silvia , Chastanet Guillaume , Marchivie Mathieu , Goux‐Capes Laurence 
Published: February 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Two‐primary crosstalk model for characterizing liquid crystal displays
Authors: Wen Senfar , Wu Royce 
Published: February 2006

AbstractThe conventional methods for colorimetric characterization of displays assume that the displays satisfy the constraints of primary chromaticity invariance across gray levels and primary channel independence. The liquid crystal displays (LCDs) that reasonably satisfy the two constraints have been accurately characterized with the conventional methods and black‐level correction. For the LCDs that do not reasonably satisfy the two constraints, we propose a higher‐order method for accurate colorimetric characterization. Two‐primary crosstalk (TPC) is observed for two tested LCDs that may be due to signal interference. We derive the crosstalk function and develop the TPC model for characterizing the LCDs, which comprises a set of the simultaneous equations with offset constants, one‐color variables, and two‐color‐product variables. The results show that the accuracy of the TPC model is significantly improved compared with conventional device models and only slightly worse than the three‐dimensional look‐up‐table (3D‐LUT) model, while the numbers of measurement data are 49 and 512 for the TPC and 3D‐LUT models, respectively. The average color difference of 224 test samples is about 2.0 (1976 CIELAB color difference formula) with the TPC model for the LCD monitor either with higher or with lower two‐primary crosstalk. While the proposed TPC model yields improved characterization accuracy over conventional models, the TPC model is evaluated on only two LCDs of the same manufacturer. Thus, the generality of the LCD crosstalk deficiency is unknown and should be determined in future research. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 90–101, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20187
The Villalobos Colour Atlas: An analysis
Authors: Brown Megan , Kuehni Rolf G. , Hinks David 
Published: February 2006

AbstractThe Villalobos Colour Atlas with its 7273 samples, published in 1947 in Argentina, represents one of the most ambitious attempts at a systematic object color sample collection. Its authors saw it as a practical visual color measuring and specification instrument at a time when spectrophotometers were a rarity in research institutes. In part, its organization is similar to that of the Munsell system but differs in regard to saturation. After a brief description of the structure of the Atlas data, what may be the first extensive measurement data of samples of the Atlas is presented in the CIELAB system. The results, unsurprisingly, show that the Atlas (as represented by the over‐60‐year‐old copy) meets some of its stated goals only to a limited extent. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 109–116, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20188
Irregularity in CIECAM02 and its avoidance
Authors: Brill Michael H. 
Published: February 2006

AbstractWere it not for an algorithm patch, the color‐appearance model CIECAM02 would sometimes be forced to evaluate fractional powers of negative numbers. The artifact arises because the red and green primaries of the initial CAT02 chromatic adaptation lie outside the positive gamut of the Hunt–Pointer–Estévez (HPE) primaries that subsequently convey the color signal in the model. Relocating the chromaticities of the HPE red and green primaries so as to lie on the CAT02 red–green line alleviates the problem, but adds a bit of X and Y to the revised HPE blue. An (x,y) diagram aids in visualizing the CIECAM02 gamut overlaps, with an extension that accommodates the HPE RGB triangle's enclosure of the point at infinity. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 142–145, 2006
Derivation of the Gross‐Pitaevskii hierarchy for the dynamics of Bose‐Einstein condensate
Authors: Erdős László , Schlein Benjamin , Yau Horng‐Tzer 
Published: February 2006

AbstractConsider a system of N bosons on the three‐dimensional unit torus interacting via a pair potential N2V(N(xi − xj)) where x = (x1, …, xN) denotes the positions of the particles. Suppose that the initial data ψN, 0 satisfies the condition

where HN is the Hamiltonian of the Bose system. This condition is satisfied if ψN, 0 = WNϕN, 0 where WN is an approximate ground state to HN and ϕN, 0 is regular. Let ψN, t denote the solution to the Schrödinger equation with Hamiltonian HN. Gross and Pitaevskii proposed to model the dynamics of such a system by a nonlinear Schrödinger equation, the Gross‐Pitaevskii (GP) equation. The GP hierarchy is an infinite BBGKY hierarchy of equations so that if ut solves the GP equation, then the family of k‐particle density matrices ⊗k|ut〉 〈ut| solves the GP hierarchy. We prove that as N → ∞ the limit points of the k‐particle density matrices of ψN, t are solutions of the GP hierarchy. Our analysis requires that the N‐boson dynamics be described by a modified Hamiltonian that cuts off the pair interactions whenever at least three particles come into a region with diameter much smaller than the typical interparticle distance. Our proof can be extended to a modified Hamiltonian that only forbids at least n particles from coming close together for any fixed n. © 2006 Wiley Periodicals, Inc.
Mathematical Modelling and Simulation of Adsorption Processes at Spherical Microparticles
Authors: Chevallier François G. , Šljukić Biljana , Wildgoose Gregory G. , Jiang Li , Jones Timothy G. J. , Compton Richard G. 
Published: February 2006

AbstractA model for the adsorption process at spherical microparticles under transient diffusion conditions has been developed and solved using numerical simulation. This model allowed us to demonstrate that the system is controlled by two main dimensionless parameters: the adsorption rate constant ka′ and the saturation parameter β. Analytical models for the adsorption process at spherical microparticles under steady‐state mass transport conditions have been derived. These models use previously developed empirical relationships for the calculation of the mass transfer coefficient (kc ). The properties of the system were studied for both the case where mass transport is described by diffusion only and the case where it is the result of a coupled diffusion/convection process. These mathematical tools were then used to analyse the results obtained for the uptake of CuII by glassy carbon powder modified with the monomer L‐cysteine methyl ester and to extract a minimum value for the adsorption rate constant which was found to be of the order of 10−4 cm s−1.
Quantitative flow cytometry of ZAP‐70 levels in chronic lymphocytic leukemia using molecules of equivalent soluble fluorochrome
Authors: Kay Sigi , Herishanu Yair , Pick Marjorie , Rogowski Ori , Baron Shoshana , Naparstek Elizabeth , Polliack Aaron , Deutsch Varda R. 
Published: February 2006

AbstractBackgroundZAP‐70 has emerged as a potential pivotal prognostic marker for patients with chronic lymphocytic leukemia (CLL), which could replace immunoglobulin heavy chain mutation status. Although several flow cytometry assays have been described for assessing ZAP‐70 in CLL, certain technical and scientific issues remain unsolved, which have prevented results of this crucial test from being reported, even in the best routine flow cytometry laboratories. In this report, we aimed to solve some of these issues by providing a computerized quantitative flow cytometric assay for ZAP‐70 within the entire CLL population, which would be easy to perform and enable standardization between laboratories.MethodsIntracellular ZAP‐70 levels in CLL and normal B cells were assessed by molecules of equivalent soluble fluorochrome (MESF), employing Quantum FITC MESF calibration beads to establish a standard curve relating channel value to fluorescence intensity in MESF units and the QuickCal v. 2.2 program (www.bangslabs.com) and clinical relevance of the data was determined.ResultsThe average ZAP‐70 expression value in the CD19+/CD5+ cells from 35 CLL patients was 103,701 MESF when compared with 12,621 MESF in B cells from 20 normal blood samples. “Low” and “high” ZAP‐70 CLL subgroups were defined. Patients with “high ZAP‐70 MESF” CLL had a shorter time to disease progression (P = 0.0005) and a more advanced clinical stage (P = 0.0018) when compared with patients in the “low ZAP‐70 MESF” CLL subgroup.ConclusionsThis quantitative analysis method can be employed to obtain a more specific and highly accurate assessment of ZAP‐70 levels in CLL cells. The method can easily be standardized, in any routine flow laboratory, thereby improving reproducibility and reliability of ZAP‐70 analysis. © 2006 International Society for Analytical Cytology
Comparison between pimonidazole binding, oxygen electrode measurements, and expression of endogenous hypoxia markers in cancer of the uterine cervix
Authors: Jankovic B. , Aquino‐Parsons C. , Raleigh J. A. , Stanbridge E. J. , Durand R. E. , Banath J. P. , MacPhail S. H. , Olive P. L. 
Published: February 2006

AbstractBackground:Although tumor hypoxia has been associated with a more aggressive phenotype and lower cure rate, there is no consensus as to the method best suited for routine measurement. Binding of the chemical hypoxia marker, pimonidazole, and expression of the endogenous hypoxia markers HIF‐1α and CAIX were compared for their ability to detect hypoxia in tumor biopsies from 67 patients with advanced carcinoma of the cervix.Methods:Two biopsies were taken one day after administration of pimonidazole and were analyzed for pimonidazole binding using flow cytometry or immunohistochemistry. CAIX and HIF‐1α expression and degree of colocalization were measured in sequential antibody‐stained sections. Patient subsets were examined for tumor oxygen tension using an Eppendorf electrode, S phase DNA content, or change in HIF‐1α expression over the course of treatment.Results:Approximately 6% of the tumor area stained positive for pimonidazole, HIF‐1α, or CAIX. The CAIX positive fraction correlated with the pimonidazole positive fraction (r = 0.60). Weaker but significant correlations were observed between pimonidazole and HIF‐1α (r = 0.31) and CAIX and HIF‐1α (r = 0.41). Taking the extent of marker colocalization into consideration increased the confidence that all markers were identifying hypoxic regions. Over 65% of stained areas showed a high degree of colocalization with the other markers. Oxygen microelectrode measurements and S phase fraction were not correlated with the hypoxic fraction measured using the three hypoxia markers. HIF‐1α levels tended to decrease with time after the start of therapy.Conclusions:Endogenous hypoxia marker binding shows reasonable agreement, in extent and location, with binding of pimonidazole. CAIX staining pattern is a better match to the pimonidazole staining pattern than is HIF‐1α, and high CAIX expression in the absence (or low levels) of HIF‐1α may indicate a different biology. © 2005 International Society for Analytical Cytology
A simple correction for cell autofluorescence for multiparameter cell‐based analysis of human solid tumors
Authors: Smith Charles A. , Pollice Agnese , Emlet David , Shackney Stanley E. 
Published: February 2006

AbstractBackground:Corrections that have been proposed to minimize the unwanted contribution of cell autofluorescence to the total fluorescence signal often require either specialized instrumentation or the sacrifice of a data channel so as to perform a measurement that can be used to correct for autofluorescence in individual cells. Here we propose a simple cell by cell correction for autofluorescence that is suitable for multiparameter laser scanning cytometry (LSC) studies in human solid tumors that relies on the ratio of mean autofluorescence to mean total cell fluorescence (mean Flauto/mean Fltotal). This approach assumes a correlation between the autofluorescence component and the total signal in individual cells. This correction does not require specialized instrumentation, and does not sacrifice a data channel in multiparameter studies. A potential disadvantage is that errors may be introduced by the assumption of a correlation between the two components of the total fluorescence signal in individual cells in samples in which no such correlation exists.Methods:Distributions of cell autofluorescence and total Her‐2/neu cell fluorescence were obtained separately by LSC in three human breast cancer cell lines and in three samples of primary human lung cancer. In the breast cancer cell lines, autofluorescence measurements and Her‐2/neu measurements were also obtained on the same cells.Results:We show that there is a partial correlation between autofluorescence and total Her‐2/neu/FITC fluorescence in individual cells in the three breast cancer cell lines. We also show that the results of a ratio‐based autofluorescence correction agree with those based on a true cell by cell correction. Computer simulation studies suggest that in samples with no correlation between the autofluorescence component and the true probe/dye fluorescence component, the ratio correction produces robust estimates of the mean true fluorescence signal, with relatively small but systematic underestimates of the coefficient of variation of such measurements under conditions commonly encountered in the measurement of human solid tumors.Conclusions:A simple cell by cell correction for autofluorescence based on the ratio of mean Flauto to mean Fltotal can be applied in cell samples in which there is a correlation between cell autofluorescence and true probe/dye fluorescence in individual cells. In cell samples that lack this correlation, or in which it is not known whether such a correlation exists, this correction can be used with the reservation that there is a systematic but relatively small underestimation of the degree of variability of the measurements. © 2005 International Society for Analytical Cytology
Synthesis of Saponins with Cholestanol, Cholesterol, and Friedelanol as Aglycones
Authors: Schimmel Jörg , Passos Eleutério M. Inês , Ritter Gerd , Schmidt Richard R. 
Published: February 2006

AbstractProcedures for the synthesis of branched Xylβ(1→3)[Galβ(1→2)]‐Glc and Xylβ(1→3)[Galβ(1→2)]‐GlcUA trisaccharides β‐linked to the 3‐Oof cholesterol, cholestanol, and friedelanol, respectively, were developed. To this end, β‐selective glucosylation of cholesterol with glucosyl donors giving selective access to 2‐O, 3‐O, and 6‐Owas studied. This way intermediates10and21having 2‐O‐acyl, 3‐O‐benzyl and 4,6‐O‐benzylidene or also benzyl protection were obtained. Removal of the 2‐O‐acyl group and then galactosylation afforded β(1→2)‐linked disaccharide intermediates14and23. Standard manipulations with theO‐benzylidene and/orO‐benzyl protecting groups gave selective access to the 3‐Oof the glucosyl residue, thus affording with a xylosyl donor the trisaccharide β‐linked to the cholesteryl residue (compound18) as decisive intermediate. Also an alternative procedure to this compound via attachement of a Xylβ(1→3)Glc residue to cholesterol and then galactosylation could be developed. Total deprotection of18or regioselective introduction of a sulfate group and of a dodecylcarbamoyl residue at 6a‐Ofurnished saponins34,36, and38, respectively. Hydrogenation of cholesteryl disaccharide23led directly to a 3a‐O‐unprotected cholestanyl disaccharide39. β‐Selective xylosylation and transformation of the liberated glucose hydroxymethyl group into a carboxylic group afforded target molecule1bhaving the desired Xyl(1→3)[Gal(1→2)]‐GlcUA β‐linked to cholestanol. Similarly, a saponin analog was obtained having an α‐linkedL‐rhamnosyl residue instead of the β‐linkedD‐xylosyl residue. Application of the glycosylation sequence, as worked out for cholesterol, to friedelanol led to attachment of the Xylβ(1→3)[Galβ(1→2)]‐Glc residue to the 3‐O(compound54). CompleteO‐deacylation led to saponin55; oxidation of the hydroxymethyl group of the glucose residue to the carboxylic group and then deprotection afforded target molecule2containing the same trisaccharide residue as1b. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Concise Total Synthesis of Antifungal Antibiotic (+)‐Preussin
Authors: Gogoi Naminita , Boruwa Joshodeep , Barua Nabin C. 
Published: February 2006

AbstractA short synthesis of the pharmacologically important natural product (+)‐preussin is described. Two asymmetric C–C bond‐formation reactions mediated by binaphthol‐derived asymmetric catalysts have been applied to control the stereochemistry of its three stereocenters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Catalytic Hydrogenation of Cyanohydrin Esters as a Novel Approach to N‐Acylated β‐Amino Alcohols – Reaction Optimisation by a Design of Experiment Approach
Authors: Veum Lars , Pereira Silvia R. M. , van der Waal Jan C. , Hanefeld Ulf 
Published: February 2006

AbstractThe catalytic hydrogenation of acylated cyanohydrins and subsequent intramolecular migration of the acyl group to yield pharmaceutically interesting N‐acyl β‐amino alcohols is shown to be a successful one‐pot preparation method. The combination of a multistep DoE approach and high‐throughput methodology proved to be an effective strategy for the optimisation of the reaction. With the favoured catalyst/solvent combination of nickel on alumina in dioxane, both hydrogenation and acyl group migration proceeded smoothly, giving the N‐acyl β‐amino alcohols in yields (determined by GC) of up to 90 % for aliphatic substrates and up to 50 % for benzylic ones, the latter being more prone to side reactions. No racemisation was found to occur at the chiral centre of an aliphatic molecule when an enantiopure cyanohydrin ester was used, though a minor decrease in ee was observed with a benzylic substrate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Nonlinear regression analysis of steady‐state voltammograms obtained at microelectrodes
Authors: Owlia Azita , Rusling James F. 
Published: February 2006

AbstractNonlinear regression was applied to the analysis of steady‐state voltammograms obtained at carbon fiber microelectrodes. Reversible regression models were used to analyze data for oxidation of ferrocene in acetonitrile with and without added electrolyte. This analysis constitutes a test for reversibility of the redox couple. An estimate of cell resistance in highly resistive media was obtained by including ohmic drop in the model for reversible electron transfer. This allows computation of „resistance‐free”︁ voltammograms obtained in that medium. A general model for steady‐state voltammograms of quasi‐reversible electrode reactions was used to estimate simultaneously apparent standard heterogeneous electron transfer rate constants (k0′), formal potentials, and electrochemical transfer coefficients for ferrocyanide and the Co(II)/Co(I) couple of vitamin B12r. Precision for ferrocyanide with a k0′ of 0.023 cm/sec was about ±30%. Results on ferrocene suggest an upper limit for estimating k0′ of about 1–2 cm/sec when the signal/noise ratio (S/N) is large. Data for the quasi‐reversible Co(II)/Co(I) couple of vitamin B12r showed that results of reasonable precision and accuracy can be obtained for systems with poor S/N.
Electrochemical behavior of iproplatin at the carbon paste electrode
Authors: Mebsout F. , Kauffmann J. M. , Patriarche G. J. , Vereecken J. , Christian Gary D. 
Published: February 2006

AbstractThe electrochemical redox behavior of iproplatin (JM9) was investigated at the carbon paste electrode using cyclic voltammetry in the absence and presence of free chloride ions. In the absence of chloride, a diffusion‐controlled, two‐electron reduction peak (Epc1) is observed, giving a platinum(II) derivative that is oxidized to a Pt(IV) compound on cycling (Epa1). Photolytic reduction‐hydrolysis to two platinum(II) derivatives results in a Pt(II) compound which on anodic scanning is oxidized to a Pt(IV) compound (Epa2) that is subsequently reduced to'a Pt(II) compound on cycling, to give rise to a second (earlier) reduction peak (Epc2). The other (nonhydrolyzed) photolytic reduction Pt(II) product can also be reduced (E) to give Pt(O) that subsequently is oxidized to Pt oxides (E); this latter Pt(II) compound is prevalent in the presence of chloride ions, which inhibit hydrolysis.
Indirect polarographic determination of titanium
Authors: Castrillejo Yolanda , Pardo Rafael , Barrado Enrique , Batanero Pedro Sánchez 
Published: February 2006

AbstractAn indirect method has been developed for Ti(IV) determination at trace levels, by means of the formation of 11‐molybdotitanophosphoric acid, its isolation with an organic solvent, stripping with alkali, and measurement of the Mo(VI) by its catalytic effect on the polarographic reduction of hydrogen peroxide. A detection limit of 4.09 μg/liter can be achieved. The procedure has been applied successfully to a certified steel sample.
A method for the investigation of double‐layer effects at solid electrodes
Authors: Mikkelsen Susan R. , Purdy William C. 
Published: February 2006

AbstractThe study of double‐layer effects at solid electrodes is often hindered by the lack of precise values for the zero‐charge potentials. This paper presents a method with which the Guoy‐Chapman‐Stern theory can be applied to cyclic voltammetric data in the absence of zero‐charge potential values. The new method uses the voltammetric peak potentials of reversible redox couples as probes of double‐layer structure and requires the elimination of iR drop from the measured values. A new method for the elimination of iR drop is also presented, based on the proportionality of uncompensated resistance to working‐to‐reference electrode distance in an axisymmetric cylindrical cell.
Study of CIO4−‐selective electrode based on a conducting polymer polypyrrole
Authors: Lu Ziling , Sun Zhisheng , Dong Shaojun 
Published: February 2006

AbstractA conducting polymer polypyrrole (PPy) CIO4−‐selective electrode has been prepared successfully by polymerizing pyrrole (Py) in CIO4−solution on glassy carbon (GC) by electrochemical oxidation. The effects of polymerization conditions on the potentiometric response characteristics of PPy are investigated in detail. The mechanism is discussed based on the doping effect of anions in the conducting polymer. The ClO4−‐selective electrode gives Nernstian potentiometric responses over the 10−1–10−4M ClO4−range with a slope of 52–54 mV/pClO4−and detection limit of 1.8 × 10−5M.