bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gasification reactivity of char with CO2 at elevated temperatures: the effect of heating rate during pyrolysis
Authors: Liu Hao , Zhu He , Yan Liye , Huang Yongjun , Kato Shigeru , Kojima Toshinori 
Published: July 2010

ABSTRACTIntegrated coal gasification combined cycle (IGCC) technology is being promoted to make better use of energy resources, and an entrained‐flow gasifier is a key item of equipment in the process due to its high gasification efficiency, smooth discharge of molten ash, etc. The temperature and heating rate under entrained‐flow gasification conditions are very high, and these two parameters can influence the gasification reactivity of a char with CO2. Therefore, the clarification of characteristics and mechanisms of char gasification under conditions close to entrained‐flow gasification is very important. To obtain a valid kinetics of char gasification, it is necessary to clarify the effect of heating rate during pyrolysis on char reactivity. The effect of heating rate during pyrolysis on the gasification reactivity of three types of chars in CO2 was investigated experimentally at elevated temperatures in a novel fluidized bed. It was shown that even at elevated temperatures, the heating rate has significant influence on the char reactivity during gasification. A higher heating rate during pyrolysis leads to higher char reactivity of gasification, however it has only limited effect on the activation energy of char gasification with CO2. The char reactivity is closely related to its specific surface area and pore volume. The high reactivity of a char derived from pyrolysis at a high heating rate is most likely due to its enhanced porous structure as a result of the rapid release of volatile matter at a high heating rate. The effect of heating rate during pyrolysis on char reactivity is pronounced at low temperatures, and is very different for various coal types, i.e. very pronounced for a low‐rank coal. The gasification reactivity of a char is related to both the char pore structure and temperature, which suggests that even at elevated temperatures the gasification of a char with CO2 is controlled by both chemical reaction and diffusion inside the particles. Our results demonstrate that it is necessary to derive the gasification kinetics of a char at a high heating rate to obtain valid kinetic equations for an entrained‐flow gasifier. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Faculty self‐archiving: Motivations and barriers
Authors: Kim Jihyun 
Published: July 2010

AbstractThis study investigated factors that motivate or impede faculty participation in self‐archiving practices—the placement of research work in various open access (OA) venues, ranging from personal Web pages to OA archives. The author's research design involves triangulation of survey and interview data from 17 Carnegie doctorate universities with DSpace institutional repositories. The analysis of survey responses from 684 professors and 41 telephone interviews identified seven significant factors: (a) altruism—the idea of providing OA benefits for users; (b) perceived self‐archiving culture; (c) copyright concerns; (d) technical skills; (e) age; (f) perception of no harmful impact of self‐archiving on tenure and promotion; and (g) concerns about additional time and effort. The factors are listed in descending order of their effect size. Age, copyright concerns, and additional time and effort are negatively associated with self‐archiving, whereas remaining factors are positively related to it. Faculty are motivated by OA advantages to users, disciplinary norms, and no negative influence on academic reward. However, barriers to self‐archiving—concerns about copyright, extra time and effort, technical ability, and age—imply that the provision of services to assist faculty with copyright management, and with technical and logistical issues, could encourage higher rates of self‐archiving.
Insilico studies of organosulfur‐functional active compounds in garlic
Authors: Singh Yogendra P. , Singh Ram A. 
Published: July 2010

AbstractGarlic has been used medicinally since antiquity because of its antimicrobial activity, anticancer activity, antioxidant activity, ability to reduce cardiovascular diseases, improving immune functions, and antidiabetic activities and also in reducing cardiovascular diseases and improving immune functions. Recent studies identify that the wide variety of medicinal functions are attributed to the sulfur compounds present in garlic. Epidemiological observations and laboratory studies in animal models have also showed anticarcinogenic potential of organosulfur compounds of garlic. In this study, in silico analysis of organosulfur compounds is reported using the methods of theoretical chemistry to elucidate the molecular properties of garlic as it is more time and cost efficient, reduces the number of wet experiments, and offers the possibility of replacing some animal tests with suitable in silico models. The analysis of molecular descriptors defined by Lipinski has been done. The solubility of drug in water has been determined as it is of useful importance in the process of drug discovery from molecular design to pharmaceutical formulation and biopharmacy. All toxicities associated with candidate drug have been calculated. P‐Glycoprotein expressed in normal tissues as a cause of drug pharmacokinetics and pharmacodynamics has been examined. Drug–plasma protein binding and volume of distribution have also been calculated. To avoid rejection of drugs, it is becoming more important to determine pKa, absorption, polar surface area, and other physiochemical properties associated with a drug, before synthetic work is undertaken. The present in silico study is aimed at examining these compounds of garlic to evaluate its possible efficacy and toxicity under conditions of actual use in humans.
Comparison of three mathematical models for predicting the risk of additional axillary nodal metastases after positive sentinel lymph node biopsy in early breast cancer
Authors: Moghaddam Y , Falzon M , Fulford L , Williams N R , Keshtgar M R 
Published: July 2010

AbstractBackgroundWomen with breast cancer and a positive axillary sentinel lymph node (SLN) are recommended to undergo complete axillary lymph node dissection; however, further nodal disease is not always present. Mathematical models have been constructed to determine the risk of metastatic disease; three of these were evaluated independently.MethodsData from 108 women with breast cancer who had a positive SLN biopsy and completion axillary lymph node dissection were used. Measurements of additional parameters over those usually determined (such as size of SLN metastasis) were assessed under the supervision of two pathologists. These data were used to determine the predicted risk of non-SLN metastases using three mathematical models (from Memorial Sloan-Kettering Cancer Center (MSKCC), Cambridge University and Stanford University) and a comparison made with the observed findings. Analyses were made using the area under the receiver operating characteristic (ROC) curve (AUC).ResultsSome 53 (49·1 per cent) of 108 patients had a positive non-sentinel axillary lymph node metastasis. The AUC values were 0·63, 0·72 and 0·67 for the MSKCC, Cambridge and Stanford nomograms respectively.ConclusionThis independent comparison found no significant difference between the models, although the Cambridge model had the advantage of requiring fewer measurements with a more accurate predictive performance.
Critical appraisal of single port access cholecystectomy
Authors: Allemann P , Schafer M , Demartines N 
Published: July 2010

Abstract

Background
Single port access (SPA) cholecystectomy is a new concept in laparoscopic surgery. A review of existing results was performed to evaluate critically the current state of SPA with specific reference to feasibility, safety, learning curve, indications and cost-effectiveness.

Methods
All papers identified in MEDLINE until 15 February 2010 and all other relevant papers obtained from cited references were reviewed, without any language restriction. Case reports and series of fewer than three patients were excluded.

Results
After selection, 24 studies including 895 patients were analysed. None was randomized. Feasibility seems to be established, with a conversion rate of 2 per cent. SPA was not standardized and there was much technical variation. The learning curve could not be determined. Median follow-up time was 3 (range 0·25–12) months. The overall published complication rate was 5·4 per cent and the biliary complication rate 0·7 per cent. The rate of umbilical complications ranged from 2 to 10 per cent.

Conclusion
SPA cholecystectomy seems feasible, but standardization, safety and the real benefits for patients need further assessment. Uncontrolled wide adoption of this approach may be responsible for a rise in biliary complications.
Sensitive measurement of vinorelbine in dog plasma by liquid chromatography–electrospray ionization tandem mass spectrometry utilizing transitions from double‐charged precursor ions
Authors: Niwa Makoto , Kawashiro Takashi 
Published: July 2010

AbstractA sensitive high‐performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for measuring vinorelbine was developed. A 100 µL aliquot of plasma was spiked with deuterium‐labeled internal standard and subjected to solid‐phase extraction using an Oasis HLB μ‐elution plate. Two microliters of the extracted samples was directly injected into LC/MS/MS. Chromatographic separation was achieved on a Capcell Pak C18 UG column (2 × 75 mm) with a gradient elution of methanol (mobile phase B) against 0.05% formic acid in aqueous 10 mm ammonium formate (mobile phase A). The LC flow rate was set to 0.28 mL/min and the gradient (solvent B concentration) was processed from 40 to 90%. In mass spectrometric detection, observation of the reaction from a double‐charged precursor ion [M + 2H]2+ (m/z 390) to product ion m/z 122 provided very high sensitivity. The method was validated with a lower limit of detection of 0.2 ng/mL with 0.1 mL of plasma, and the method was used to determine the plasma pharmacokinetics of vinorelbine in dogs. Copyright © 2010 John Wiley & Sons, Ltd.
Development and validation of a fast isocratic liquid chromatography method for the simultaneous determination of norfloxacin, lomefloxacin and ciprofloxacin in human plasma
Authors: Sousa Joana , Alves Gilberto , Fortuna Ana , Pena Angelina , Lino Celeste , Falcão Amílcar 
Published: July 2010

AbstractA simple and fast liquid chromatographic method coupled with fluorescence detection (LC‐FD) is reported, for the first time, for the simultaneous quantification of norfloxacin (NOR), ciprofloxacin (CIP) and lomefloxacin (LOM) in human plasma, using levofloxacin as internal standard (IS). Sample preparation consists of a single‐step precipitation of plasma proteins followed by vortex‐mixing and centrifugation. Chromatographic separation was achieved within 7 min on a reversed‐phase C18 column with a mobile phase consisting of 0.1% aqueous formic acid (pH = 3.0, triethylamine)–methanol (82:18, v/v) pumped isocratically at 1.2 mL/min. The detector was set at excitation/emission wavelengths of 278/450 nm. Calibration curves were linear (r2 ≥ 0.994) in the range of 0.02–5.0 µg/mL, and the limit of quantification was established at 0.02 µg/mL for all analytes (NOR, CIP and LOM). The overall precision did not exceed 8.19% and accuracy was within ±10.91%. NOR, CIP and LOM were extracted from human plasma with an overall mean recovery ranged from 90.1 to 111.5%. No interferences were observed at the retention times of the analytes and IS. This novel LC‐FD method enables the reliable determination of NOR, CIP and LOM in a single chromatographic run, which may be suitable to support human pharmacokinetic‐based studies with those antimicrobial agents. Copyright © 2010 John Wiley & Sons, Ltd.
Calculating temperature distributions for gradient coils
Authors: While Peter T. , Forbes Lawrence K. , Crozier Stuart 
Published: July 2010

AbstractThe operation of gradient coils typically requires large currents to be driven in resistive copper wires. A major problem in gradient coil design is therefore the correspondingly large Ohmic heating that results, which can severely impact image quality or lead to system failure. Of particular concern is the location and extent of temperature hot spots in the coil system. In this article, a model is presented for predicting the spatial temperature distribution of a gradient coil. The model includes axial and azimuthal dissipation of heat via conduction throughout a copper layer, radial conduction of heat through an insulating former, and radial convection and radiation to the environment. Two steady‐state solutions for the temperature distribution are presented, involving Green's functions and Fourier series. In addition, an approximate time‐dependent solution is sought describing the hot spot temperature as a function of time, which demonstrates that the steady‐state solutions are likely to be reached within a typical scanning scenario. The impact on the temperature distribution of a great number of coil properties may be investigated using the model and examples are given for different coil geometries, thermal material properties, and cooling mechanisms, such as convective air, forced air, and forced water cooling. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 146–159, 2010
Magnitude and phase behavior of multiresolution BOLD signal
Authors: Chen Zikuan , Calhoun Vince D. 
Published: July 2010

AbstractHigh spatial resolution functional MRI (fMRI) provides a more precise estimate of brain activity than low resolution fMRI. The magnitude and phase parts of the blood‐oxygenation‐level‐dependent (BOLD) signals are impacted differently by changes in the scan resolution. In this article, we report on a numerical simulation to show the impact of spatial resolution upon the complex‐valued BOLD signal in terms of magnitude and phase variation. We generate realistic capillary networks in cortex voxels, calculate the BOLD‐induced magnetic field disturbance and the complex BOLD signals for the voxel and its subvoxels, and thereby characterize the magnitude and phase behaviors across multiple grid resolutions. Our results show that 1) at higher spatial resolution there is greater spatial variation in the phase of the BOLD signal as compared to its magnitude; 2) the spatial variation of the phase signal monotonically increases with respect to spatial resolution while for the magnitude the spatial variation may reach a maximum at some resolution level; 3) voxels containing large capillaries have higher phase spatial variation than those with smaller capillaries; and 4) the amplitude spatial variation at a resolution level increases with respect to relaxation time whereas the phase variation is generally unaffected. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 129–145, 2010
An efficient method for electrical conductivity measurement in the RF range
Authors: Giovannetti Giulio , Frijia Francesca , Menichetti Luca , Hartwig Valentina , Viti Vittorio , Landini Luigi 
Published: July 2010

AbstractMany of the hardware procedure like radiofrequency (RF) coils testing and simulation experiments such as the estimation of temperature changes in magnetic resonance imaging experiments require saline phantoms. These kinds of experimental models are generally obtained using a well‐defined container filled with conductive salt solution (i.e., diluted NaCl solution) or using a combination of conductive gel with a semi‐solid consistency. These phantoms are commonly prepared according to the standards values of the principal parameter concerning theirs dielectric properties (i.e., permittivity and electrical conductivity). Although several permittivity measurement methods have already been reported in literature, most of the data describing the electrical conductivity of these saline solutions provided by different authors are often conflicting and the frequencies of each measure are not always specified. Besides, low‐cost commercial conductimeters could provide measurements overlooking the conductivity dependence on the frequency, while the measurements in the RF range require costly coaxial probes which work with network analyzers with multi‐electrodes working in solution. In this article, we describe a system based on self‐made coil designed to measure the electrical conductivity of conductive solutions in the RF range, without any contact between the sample and the measurement probe. The estimated value of conductivity has been performed combining theoretical calculation of induced resistance in the phantom volume and experimental measurements using workbench instrumentations. The method can be applied to the whole RF range measurements by tuning the capacitor value of the resonant circuit. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 160–166, 2010
Tikhonov regularization approach for acoustic noise reduction in an asymmetric, self‐shielded MRI gradient coil
Authors: Jackson James M. , Brideson Michael A. , Forbes Larry K. , Crozier Stuart 
Published: July 2010

AbstractWe consider a mathematical method for minimizing the acoustic noise of self‐shielded magnetic resonance imaging gradient coils designed to produce an asymmetrically located target field within a cylindrical chamber. During imaging, the gradient coils are being constantly switched on and off, subjecting the coil to large Lorentz forces. These forces cause the chamber to buckle, creating a pressure wave in the bore which manifests as acoustic noise at sound pressure levels up to about 130 dB. In this model, the linearized coil deflection, the pressure wave, and the acoustic noise level inside the chamber are all solved for in closed form. The closed‐form nature of the solutions permits simple insights into the behavior of the system. Although reductions of only 0.6 dB were achieved, the method allows some flexibility if other design sacrifices are made. The gradient coil switching frequency plays a major role in the magnitude of the acoustic noise and is studied here. Results are presented for two basic switching functions for shielded gradient coils. Unshielded gradient coils, other switching functions, and other penalty functions can be easily accommodated using the method presented. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 167–179, 2010
Electrochemical determination of gatifloxacin, moxifloxacin and sparfloxacin fluoroquinolonic antibiotics on glassy carbon electrode in pharmaceutical formulations
Authors: Radi Abd‐Elgawad , Wahdan Tarek , Anwar Zeinab , Mostafa Hend 
Published: July 2010

AbstractThree fluoroquinolones; gatifloxacin (GAT), moxifloxacin (MOX) and sparfloxacin (SPAR) were electrochemically studied in various buffer systems at different pH values, using a glassy carbon electrode. The three fluoroquinolones were electrochemically oxidized at potential range (0.65–1.1 V) vs Ag‐AgCl‐KCl. The oxidation was irreversible and exhibited adsorption‐controlled process behavior at all pH values and buffers studied. An electroanalytical methodology based on the adsorptive behavior of fluoroquinolones on glassy carbon electrode (GCE) and according to the linear relation between peak current and concentration using differential pulse voltammetry (DPV) method was successfully applied to the determination of the three fluoroquinolones in bulk and tablets. The proposed methods were statistically in agreement with that obtained by spectrophotometric comparison method. Copyright © 2010 John Wiley & Sons, Ltd.
Anionic Metal–Organic Frameworks of Bismuth Benzenedicarboxylates: Synthesis, Structure and Ligand‐Sensitized Photoluminescence
Authors: Thirumurugan A. , Cheetham Anthony K. 
Published: July 2010

AbstractFour organic–inorganic bismuth benzenedicarboxylate (bdc)frameworks, [Bi(1,4‐bdc)2(dmf)]·(dma)(dmf)2 (1), [Bi(1,4‐bdc)2]·(dma)(dmf) (2), [Bi4(1,4‐bdc)7(HIm)]·(dma)2(dmf)2 (3) and [Bi(1,4‐bdc)2]·(dma) (4) (where dma = dimethyl ammonium cation, HIm = imidazole and dmf = dimethylformamide) have been synthesized under solvothermal conditions, and their structures were determined by single‐crystal X‐ray diffraction. Compound 1 has a layer structure, whereas compounds 2–4 have three‐dimensional structures. All four frameworks are anionic and contain dma cations within cavities in their structures. Compounds 1–3 also contain coordinated and/or guest dmf molecules. The topologies of compounds 1–3 have 4‐connecting nodes; the layer structure in 1 is a corrugated (4,4)‐connected square lattice, but the three‐dimensional structures of 2 and 3 adopt the (dia) net topology. Compound 4 has a 6‐connecting node with a (pcu) net topology. The BiOn polyhedra are hemidirected with a stereochemically active lone pair of electrons in 2, but holodirected with astereochemically inactive lone pair of electrons in 1, 3 and 4. Tb3+‐ and Eu3+‐doped and co‐doped 3 and 4 emit intense, ligand‐sensitized green, red or orange luminescence, respectively.
Reversible, Fine Performance Tuning of an Organometallic Molecular Wire by Addition, Ligand Replacement and Removal of Dicobalt Fragments
Authors: Tanaka Yuya , Koike Takashi , Akita Munetaka 
Published: July 2010

AbstractCommunication between the two iron centres in (dithienylethyne)diyl complex 1 can be finely tuned by reversible addition to, ligand replacement at and removal from the C≡C moiety in 1 of dicobalt fragments Co2(CO)n(PR3)6–n. Performance analysis reveals that disparate mechanisms are in operation for the two systems. In the case of the dicobalt adducts, indirect communication via the dicobalt steppingstone can be finely tuned by controlling the electronic structure of the dicobalt unit.
Diversity‐Oriented Microwave‐Assisted Synthesis of the 3‐Benzazepine Framework
Authors: Peshkov Vsevolod A. , Pereshivko Olga P. , Donets Pavel A. , Mehta Vaibhav P. , Van der Eycken Erik V. 
Published: July 2010

AbstractAn efficient diversity‐oriented procedure for the two‐step synthesis of 3‐benzazepines is described. The CuI‐catalyzed three‐component coupling of an aldehyde, an alkyne and an amine (A3‐coupling) provides the required propargylamines and assures the generation of diversity. The Pd‐catalyzed intramolecular acetylene hydroarylation reaction selectively creates the seven‐membered 3‐benzazepine framework with full control over the ring size and the geometry around the double bond. Microwave irradiation is demonstrated to be highly efficient in promoting both steps.
Fluorescent Hg2+ Sensors: Synthesis and Evaluation of a Tren‐Based Starburst Molecule Containing Fluorinated 1,2,4‐Oxadiazoles
Authors: Pibiri Ivana , Palumbo Piccionello Antonio , Calabrese Alessandro , Buscemi Silvestre , Vivona Nicolò , Pace Andrea 
Published: July 2010

AbstractA new tren‐based starburst molecule containing fluorinated 1,2,4‐oxadiazoles as fluorophores has been synthesized and its sensing behavior toward several metal cations has been investigated by UV/Vis, fluorescence, 1H NMR and 19F NMR spectroscopy. Selective sensing for Hg2+ ions through a PET‐based mechanism was evidenced, suggesting application as fluorescent sensor for Hg2+ of the off‐on type.
Synthesis of new functionalized aminomethylphosphonites and their derivatives
Authors: Prishchenko Andrey A. , Livantsov Mikhail V. , Novikova Olga P. , Livantsova Ludmila I. , Petrosyan Valery S. 
Published: July 2010

AbstractThe aminomethylation of the several esters of hypophosphorous acid using chloro‐, alkoxy‐, and amino‐substituted methylamines of various structure is proposed as convenient method for the synthesis of new functionalized aminomethylphosphonites and bis(aminomethyl)phosphinates. Also O,O‐diethyl(pivaloyl)phosphonite is successfully applied in the aminomethylation as a synthetic analog of unstable diethoxyphosphine. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:361–367, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20620