bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copolymerization of phenylisocyanate and ϵ‐caprolactone with rare earth chloride systems
Authors: Ni Xufeng , Xu Xiaoyan , Shen Zhiquan 
Published: November 2006

AbstractA copolymer of phenylisocyanate (PhNCO) and ε‐caprolactone (CL) was synthesized by the rare earth chloride systems lanthanide chloride isopropanol complex (LnCl3·3iPrOH) and propylene epoxide (PO). Polymerization conditions were investigated, such as lanthanides, reaction temperature, monomer feed ratio, La/PO molar ratio, and aging time of catalyst. The optimum conditions were: LaCl3 preferable, [PhNCO]/[CL] in feed = 1 : 1 (molar ratio), 30°C, [monomer]/[La] = 200, [PO]/[La] = 20, aging 15 min, polymerization in bulk for 6 h. Under such conditions the copolymer obtained had 39 mol % PhNCO with a 78.2% yield, Mn = 20.3 × 103, and Mw/Mn = 1.60. The copolymers were characterized by GPC, TGA, 1H‐NMR, and 13C‐NMR, and the results showed that the copolymer obtained had a blocky structure with long sequences of each monomer unit. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2135–2140, 2007
Phenyl urea derivatives as organic stabilizers for rigid poly(vinyl chloride) against photo‐degradation
Authors: Sabaa Magdy W. , Mohamed Riham R. 
Published: November 2006

AbstractPhenyl urea derivatives have been prepared and investigated as photostabilizers for rigid PVC by measuring the extent of weight loss (%), the amount of gel formation as well as the intrinsic viscosity of the soluble fractions of the degraded polymer. Moreover, the efficiency of these stabilizers was evaluated from the extent of discoloration of the degraded polymer in their presence. The results indicated a reasonable stabilizing effect of these derivatives when compared with the commercially used UV stabilizers: phenyl salicylate (Salol) and methanone, 2‐hydroxy‐4‐(octyloxy)‐phenyl‐benzophenone. A synergistic effect is achieved when the phenyl urea derivatives are mixed with the UV absorbers in the ratio (75 : 25%), respectively. A radical mechanism is proposed to account for the stabilizing action of the products investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2217–2226, 2007
Virus‐PLoc: A fusion classifier for predicting the subcellular localization of viral proteins within host and virus‐infected cells
Authors: Shen Hong‐Bin , Chou Kuo‐Chen 
Published: November 2006

AbstractViruses can reproduce their progenies only within a host cell, and their actions depend both on its destructive tendencies toward a specific host cell and on environmental conditions. Therefore, knowledge of the subcellular localization of viral proteins in a host cell or virus‐infected cell is very useful for in‐depth studying of their functions and mechanisms as well as designing antiviral drugs. An analysis on the Swiss‐Prot database (version 50.0, released on May 30, 2006) indicates that only 23.5% of viral protein entries are annotated for their subcellular locations in this regard. As for the gene ontology database, the corresponding percentage is 23.8%. Such a gap calls for the development of high throughput tools for timely annotating the localization of viral proteins within host and virus‐infected cells. In this article, a predictor called “Virus‐PLoc” has been developed that is featured by fusing many basic classifiers with each engineered according to the K‐nearest neighbor rule. The overall jackknife success rate obtained by Virus‐PLoc in identifying the subcellular compartments of viral proteins was 80% for a benchmark dataset in which none of proteins has more than 25% sequence identity to any other in a same location site. Virus‐PLoc will be freely available as a web‐server at http://202.120.37.186/bioinf/virus for the public usage. Furthermore, Virus‐PLoc has been used to provide large‐scale predictions of all viral protein entries in Swiss‐Prot database that do not have subcellular location annotations or are annotated as being uncertain. The results thus obtained have been deposited in a downloadable file prepared with Microsoft Excel and named “Tab_Virus‐PLoc.xls.” This file is available at the same website and will be updated twice a year to include the new entries of viral proteins and reflect the continuous development of Virus‐PLoc. © 2006 Wiley Periodicals, Inc. Biopolymers 85: 233–240, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
High‐performance liquid chromatography and LC‐ESI‐MS method for the identification and quantification of two biologically active polyisoprenylated benzophenones xanthochymol and isoxanthochymol in different parts of Garcinia indica
Authors: Kumar Satyanshu , Chattopadhyay Sunil K. 
Published: November 2006

AbstractA reverse‐phase high‐performance liquid chromatographic method was developed for qualitative and quantitative analysis of xanthochymol (1), and isoxanthochymol (2) in the fruit rinds, leaves and seed pericarps of Garcinia indica with confirmation using PDA detection and electrospray ionization MS. Absorption at 276 nm was chosen as the measuring wavelength at which resolution and baseline separation of compounds (1) and (2) could be obtained. The identity of the above two isomeric compounds (1) and (2) in the samples was unambiguously determined by their respective quasi‐molecular ion [M – H]− in ESI‐MS. Compounds (1) and (2) were qualitatively and quantitatively analyzed in the above three samples of Garcinia indica. The overall analytical procedure is rapid and reproducible and is considered for the analysis of the above two compounds. Copyright © 2006 John Wiley & Sons, Ltd.
Microlaryngoscopic repair of iatrogenic pharyngeal pouch perforations: Treatment of choice?
Authors: Paleri Vinidh , Najim Omar , Meikle David , Wilson Janet A. 
Published: November 2006

AbstractBackground.Endoscopic stapled diverticulostomy (ESD) has become the preferred technique for managing pharyngeal pouches. Iatrogenic perforation, created during stapling, is a rare but serious complication with significant morbidity and mortality. The conventional management in these instances is to convert it to an external procedure and excise the pouch.Methods.Iatrogenic perforations were noticed after stapling in 3 cases in our series of 73 patients who underwent ESD. They were repaired using microlaryngoscopic techniques.Results.All patients had an unremarkable postoperative course.Conclusions.Selected cases with iatrogenic perforations can be repaired primarily and observed with excellent outcome, obviating the need for an external pouch excision. © 2006 Wiley Periodicals, Inc. Head Neck, 2007
Evaluation of recurrent nodal disease after definitive radiation therapy for nasopharyngeal carcinoma: Diagnostic value of fine‐needle aspiration cytology and CT scan
Authors: Tar Toh Song , Wai Yuen Heng , Hong Goh Yau , Hood Keng Goh Christopher 
Published: November 2006

AbstractBackground.Recurrent nodal disease in patients with nasopharyngeal carcinoma (NPC) after definitive radiotherapy presents a difficult clinical problem. This cohort of patients poses a diagnostic challenge to the head and neck surgeon because evaluation of the post‐irradiated neck, both clinically and radiologically, is known to be difficult, and it is not uncommon for neck dissection specimen in suspected recurrent nodal disease to contain no viable tumor cells. Currently, there is no well‐accepted method for the preoperative determination of the presence of malignancy in these nodal diseases.Methods.Over a 7‐year period in a tertiary hospital, we systematically reviewed the clinical charts of 42 patients with NPC who were diagnosed with suspected recurrent nodal disease, after radical definitive radiotherapy. Fine‐needle aspiration cytology (FNAC) was performed on clinically palpable nodes and results were correlated with final histopathologic results. Findings on CT scan were also correlated with final histopathologic specimens.Results.The specificity and sensitivity of FNAC was 75.0% and 75.0%, respectively. The positive and negative predictive value of FNAC was 93.8% and 37.5%, respectively. CT scan had a positive predictive value of 78.6%. The negative predictive value for multilevel involvement on CT scan was 20%.Conclusion.Radiological imaging and FNAC are useful diagnostic modalities in assessing recurrent nodal disease in the post‐irradiated neck in patients with NPC. Although routine CT scan criteria for pathologic lymphadenopathy cannot be accurately applied in the post‐irradiated neck, it is a useful surveillance tool in the routine follow‐up of patients with post‐irradiated neck with NPC. Clinicians, however, must understand their limitations when assessing these patients. The possibility of negative neck dissection must be conveyed to the patients. © 2006 Wiley Periodicals, Inc. Head Neck, 2007
The synoptic climate controls on hydrology in the upper reaches of the Peace River Basin. Part I: snow accumulation
Authors: Romolo L. , Prowse T. D. , Blair D. , Bonsal B. R. , Martz L. W. 
Published: November 2006

AbstractFor most cold region rivers, winter snowpack accumulation is the main contributor to spring run‐off events. This study investigated the synoptic controls on snowpack variability in the upper reaches of the Peace River Basin. An examination of snowpack accumulation at Grande Prairie, Alberta, revealed considerable inter‐annual variability for the period 1963–1996. Moreover, a decadal‐scale shift was evident with the magnitude of the snowpack being significantly reduced after 1976.An eigenvector‐based map‐pattern classification procedure identified 16 patterns, of which 10 are classified as dry (non‐efficient precipitators) and 6 as wet (efficient precipitators). A frequency analysis demonstrated that variances in the occurrence of synoptic patterns were significantly related to variances in the magnitude of the snowpack at Grande Prairie on both an inter‐annual and inter‐decadal basis. Further analysis revealed that variances in the Pacific/North American (PNA) pattern influenced the local synoptic regime with wet (dry) types dominating under the negative (positive) PNA or zonal (meridional) flow. Although the Southern Oscillation Index (SOI) was found to have a significant impact on wet/dry‐type occurrence, it was revealed that El Niño events were associated with average synoptic conditions, while La Niña events were associated with a significant increase (decrease) in wet (dry) type frequency. A storm track analysis further identified that the occurrence of the wet and dry synoptic patterns influences the magnitude and position of surface lows in and around the Peace River Basin, and western Canada. Copyright © 2006 John Wiley & Sons, Ltd.
The synoptic climate controls on hydrology in the upper reaches of the Peace River Basin. Part II: Snow ablation
Authors: Romolo L. , Prowse T. D. , Blair D. , Bonsal B. R. , Marsh P. , Martz L. W. 
Published: November 2006

AbstractThe timing and rate of spring snowmelt in the upper reaches of the Peace River Basin control the development of large upstream spring flood waves and subsequent downstream ice‐jam flooding events. Given that snowmelt is controlled by atmospheric processes, this study identified the mid‐tropospheric circulation patterns that control the timing and rate of the snowmelt season on a critical tributary of the Peace River Basin.Results showed that the date of spring snowmelt initiation in the upper Peace has become significantly earlier over the study period (1963–1996). This was explained by a significant increasing (decreasing) trend in the occurrence of mid‐tropospheric ridging (troughing and zonal flow) patterns, which are associated with above (below) average mean daily temperatures and available melt energy at Grande Prairie. Further analysis revealed that variances in the timing and rate of melt at Grande Prairie could be explained by variances in the local synoptic regime.Examination of the broad‐scale atmospheric controls identified that the variances in the occurrence of the synoptic patterns could be explained by variances in the Pacific/North American teleconnection pattern. Although El Niño events were associated with average synoptic and snow ablation conditions, La Niña events were found to significantly impact the March synoptic regime over western Canada, and subsequently, the melt timing at Grande Prairie. Copyright © 2006 John Wiley & Sons, Ltd.
Modelling climate change impacts in the Peace and Athabasca Catchment and delta: II—variations in flow and water levels with varying winter severity
Authors: Leconte Robert , Peters Daniel , Pietroniro Alain , Prowse Terry 
Published: November 2006

AbstractAs freshwater ice is known to significantly affect flows and water levels within the Peace–Athabasca Delta (PAD), a winter severity sensitivity analysis using a one‐dimensional open channel hydraulic model was performed for four climate scenarios (from mild to severe), and was examined under three differing flow conditions (low, average, and high hydraulic regimes), in an effort to better understand the multiple interactions between ice cover and the hydrodynamic regime of this complex system characterized by overbank flooding and flow reversal episodes. In general, a reduction of winter severity lowered lake levels and river flows. While the winter severity effect is of relatively short duration in the rivers, the subsequent reduction in lake levels extends over the summer months. High river flows predispose flow reversal conditions, and water enters the lakes at the outlet as the water levels in the rivers feeding the PAD increase significantly over a short period of time. This flow reversal effect is suppressed during milder winters. Numerical modelling results indicate that extending the ice‐cover season (severe winter) by 14 days resulted in an increase of up to 5 cm in water level of large lakes in the PAD, while reducing it by 28 days lowered the levels by almost 10 cm. Short‐term variations in river levels reached up to 1·5 m as a result of varying the extent of the ice‐cover season. As the simulation runs did not consider ice‐jam events and neglected the effect of ice thickness on water levels, the reported quantitative results must be interpreted with prudence. Copyright © 2006 Crown in the right of Canada, and John Wiley & Sons, Ltd.
Single photon correlation measurements in a study of excitation process of individual CdTe/ZnTe quantum dots
Authors: Suffczyński J. , Kazimierczuk T. , Goryca M. , Trajnerowicz A. , Kowalik K. , Kossacki P. , Golnik A. , Nawrocki M. , Gaj J. A. , Karczewski G. 
Published: November 2006

AbstractWe present the results of systematic autocorrelation and cross‐correlation measurements performed on photons originating from various excitonic transitions in a single CdTe/ZnTe quantum dot (QD). Excitation power dependence of photoluminescence intensity was also measured on the same dot under the same experimental conditions. Recorded correlation histograms have provided evidence for memory effects in QD photoluminescence extending over a few excitation periods. Rate equation model assuming a ladder of states and excitation through a single carrier and exciton capture, is fitted to the data. As a consequence, simultaneous quantitative description of the results of both, correlation and power dependence, is obtained. Strong evidence is presented for a QD excitation by capture of single carriers rather than entire excitons. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Controlling spontaneous emission from quantum dots using photonic crystal microcavities
Authors: Gevaux D. G. , Atkinson P. , Anderson D. , Bennett A. J. , Bremner S. P. , Griffiths J. , Ellis D. J. P. , Stevenson R. M. , Jones G. A. C. , Ritchie D. A. , Shields A. J. 
Published: November 2006

AbstractControlling the radiative lifetime of quantum dot excitons by using microcavities provides a means of improving the performance of single photon sources. By manipulating the density of optical states in the environment of the quantum dot, the rate of spontaneous recombination can be altered by the Purcell effect. The emitted light can also be concentrated into a smaller extraction cone, improving efficiency. We investigate the use of temperature to spectrally tune an InAs self‐assembled quantum dot exciton and the mode of a photonic crystal defect cavity. A Purcell enhancement of the spontaneous emission rate of up to a factor of 11.4 is seen on‐resonance, while suppression by up to a factor of 4.4 is seen off‐resonance. Also, a two orders of magnitude increase in the intensity of light detected is measured when compared to quantum dots in bulk GaAs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InAs/InP(001) quantum dots and quantum sticks grown by MOVPE: shape, anisotropy and formation process
Authors: Michon A. , Patriarche G. , Sagnes I. , Beaudoin G. , Saint‐Girons G. 
Published: November 2006

AbstractThis contribution presents a thermodynamical analysis of the formation process of InAs/InP(001) quantum dots (QDs) or quantum sticks (QSs) grown by metalorganic vapor phase epitaxy. This study, based on an analytical model of Tersoff et al. adapted to our QD geometry, describes the origin of QD shape anisotropy and size dispersion. It also explains the shape transition from QDs to QSs under As‐poor growth conditions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Emission lineshape in strain free quantum dot
Authors: Poliani E. , Bonfanti M. , Sanguinetti S. , Grilli E. , Guzzi M. , Gurioli M. , Abbarchi M. , Koguchi N. 
Published: November 2006

AbstractWe present a detailed study of the temperature dependence of the single quantum dot emission lineshape in strain free, GaAs/AlGaAs quantum dots. In particular, we analyze the emission lineshape in terms of linewidth, peak energy and sidebands. These quantities are all connected with the nature of the electron–phonon interaction. We conclude that the line broadening in quantum dots is due to pure dephasing processes driven by GaAs‐LO phonons. In addition, there is a lack of quantum size effect on the excitonic energy renormalization with the temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vertical homonuclear quantum ring molecules
Authors: Malet F. , Pi M. , Mayol R. , Barranco M. , Lipparini E. , Climente J. I. , Planelles J. 
Published: November 2006

AbstractWithin Local Spin Density Functional Theory, we have investigated the structure of homonuclear, fewelectron circular vertical semiconductor double quantum rings artificial molecules at zero magnetic field, and have obtained the addition spectrum as a function of inter‐ring distance. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High precision numerical estimates of acoustic phonon frequencies of nonspherical nanoparticles
Authors: Murray Daniel B. , Laarakker Avra S. , Saviot Lucien 
Published: November 2006

AbstractWe introduce an adapted method for calculating the acoustic vibrational frequencies of arbitrarily shaped nanoparticles to high precision. Molecular dynamics simulation results are tested against exact solutions for a free sphere, a hollow sphere and a spheroid. This permits theoretical predictions of the frequencies of peaks in low frequency Raman spectra. Our results demonstrate that vibrational frequencies can be calculated for a wide range of low frequency modes with accuracies on the order of a tenth of a percent. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure‐induced optoelectronic properties of InP nanocrystals: Tight‐binding approach
Authors: Díaz J. G. , Jaskólski W. , Zieliński M. , Bryant G. W. 
Published: November 2006

AbstractAn empirical tight‐binding theory is used to investigate pressure effects on the electronic and optical properties of InP nanocrystals. For bulk InP, our model predicts the Γ–X crossing of the conduction band minima at exactly the same lattice contraction as measured in the experiment. For small InP nanocrystals, the model correctly predicts the pressure dependence of the fundamental energy gap and luminescence intensity. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dephasing of orbital and spin degrees of freedom in semiconductor quantum dots due to phonons and magnons
Authors: Jacak W. , Krasnyj J. , Jacak J. , Gonczarek R. , Jacak L. 
Published: November 2006

AbstractPhonon‐induced decoherence of orbital degrees of freedom in quantum dots (QDs) (GaAs/InAs) is studied and the relevant time‐scales are estimated versus dot dimension. Dephasing of excitons due to acoustic phonons and optical phonons, including enhancement of the effective Fröhlich constant caused by localization, is assessed for the state‐of‐art QDs. Temporal inefficiency of Pauli blocking in QDs due to lattice inertia is additionally predicted. For QD placed in a diluted magnetic semiconductor medium a magnon induced dephasing of spin is estimated in accordance with experimental results for Zn(Mn)Se/CdSe. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InAs/InP quantum dot photonic crystal microcavities
Authors: Frédérick Simon , Dalacu Dan , Poole Philip J. , Lapointe Jean , Aers Geof C. , Williams Robin L. 
Published: November 2006

AbstractWe examine the optical mode structure of two‐dimensional, photonic crystal microcavities based on triple missing hole defects in hexagonal symmetry, etched air‐hole, suspended InP membranes. Polarisation dependent photoluminescence from InAs/InP quantum dots embedded within the cavities is used to explore mode energies and quality factors, Q, as a function of cavity design parameters. Optimised Q values are in excess of 7,500 for the modified y‐dipole mode. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pure dephasing of two charge qubits in coupled quantum dots
Authors: Ben Chouikha W. , Jaziri S. , Bennaceur R. 
Published: November 2006

AbstractWe study the pure dephasing of two electrons confined in vertically coupled quantum dots, in which the presence of one electron confined in the double dot represents one qubit. We numerically evaluated the dephasing rates due to electrons coupling to both acoustic and optical phonons. Our numerically results show that the pure dephasing rates dependent on the separation between dots and the strength of electrons confinement. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoreflectance investigations of energy level structure of InAs quantum dashes embedded in InGaAs/InGaAlAs quantum well grown on InP substrate
Authors: Rudno‐Rudziński W. , Kudrawiec R. , Sęk G. , Misiewicz J. , Somers A. , Schwertberger R. , Reithmaier J. P. , Forchel A. 
Published: November 2006

AbstractPhotoreflectance (PR) and photoluminescence measurements have been performed on molecular beam epitaxy grown InAs quantum dashes (QDash) of various sizes, embedded in In0.53Ga0.47As/In0.53Ga0.23Al0.24As quantum well (QW), grown on InP substrate. PR response from all relevant parts of the structure, i.e InAs/In0.53Ga0.47As QDashes, InAs/In0.53Ga0.47As/In0.53Ga0.23Al0.24As QW, and In0.53Ga0.23Al0.24As barriers, has been obtained. The lowest energy transition related to the ground state transition in QDashes shifts towards red with the increase in QDash sizes (amount of deposited InAs material) reaching wavelengths longer than for structures without the intermediate QW. The experimental data on the energies of optical transitions combined with the numerical calculation within the effective mass approximation has allowed determining the energy level structure of the entire system, including the values of conduction band offset between InGaAs and InGaAlAs layers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)