bluuebunny/crossref_metadata_2025_split huggingface dataset:
Luminescence properties of isolated InGaN/GaN quantum dots
Authors: Martin R. W. , Edwards P. R. , Taylor R. A. , Rice J. H. , Na J. H. , Robinson J. W. , Smith J. D. , Liu C. , Watson I. M. 
Published: February 2005

AbstractInxGa1–xN quantum dots have been fabricated by the selective growth of GaN micro‐pyramid arrays topped with InGaN/GaN quantum wells. The spatially‐ and spectrally‐resolved luminescence properties of these structures were measured using low‐temperature micro‐photoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit linewidths down to 650 µeV (limited by the spectrometer resolution). We describe the broadening of the luminescence peak from a single dot as a function of temperature and excitation power. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical spin polarization in double charged InAs self‐assembled quantum dots
Authors: Kalevich V. K. , Merkulov I. A. , Shiryaev A. Yu. , Kavokin K. V. , Ikezawa M. , Okuno T. , Brunkov P. N. , Zhukov A. E. , Ustinov V. M. , Masumoto Y. 
Published: February 2005

AbstractThe work is an experimental study of optical spin polarization in InAs/GaAs quantum dots (QDs) with 2 resident electrons or holes. A capture of a photo‐generated electron‐hole pair into such a QD creates a negative or positive tetron (double‐charged exciton). Spin polarization was registered by the circular polarization of the QD photoluminescence (PL). The spin state was found to differ radically in the dots with opposite in sign charge. Particularly, under excitation in a GaAs barrier, the ground state PL polarization is negative (relative to the polarization of an exciting light) in the negatively charged QDs and positive in the positively charged QDs. With increasing excitation intensity, the negative polarization rises from zero up to a saturation level, while the positive polarization decreases. The negative polarization increases in weak magnetic fields applied in Faraday geometry, but strong fields suppress it. The positive polarization always increases as a function of magnetic field. We propose a theoretical model that qualitatively explains the experimental results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN/AlGaN nanocavities with AlN/GaN Bragg reflectors grown in AlGaN nanocolumns by plasma assisted MBE
Authors: Ristić J. , Calleja E. , Fernández‐Garrido S. , Trampert A. , Jahn U. , Ploog K. H. , Povoloskyi M. , Carlo A. Di 
Published: February 2005

AbstractThe successful growth of AlGaN nanocolumns by plasma assisted MBE, with different Al compositions, opened the way for achieving nano‐heterostructures including GaN Quantum Discs (QDss). The luminescence emission from the QDss embedded in the AlGaN nanocolumns was tuned by changing their thickness and/or the Al composition of the barriers. Such a nano‐heterostructure was then enclosed between two AlN/GaN Distributed Bragg Reflectors (DBR), with nominal reflectivities of 90 and 50%. The choice of the AlN/GaN bilayers for the DBRs allowed to reach these reflectivity values with a significantly lower number of periods, as compared to the AlGaN/GaN stacks. The resulting nanocavity has been characterized by cathodoluminescence (CL), and Scanning and Transmission Electron Microscopy (SEM, TEM). CL measurements show that the emission from the nanocavity is quite close to the targeted value. TEM data points to the need of optimized conditions to grow AlN columnar layers in order to avoid the lateral overgrowth in the columnar nanostructure. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of B3LYP and MP2 conformational population distributions in trans‐nicotine, acetylcholine, and ABT‐594
Authors: Mora M. , Castro M. E. , Niño A. , Melendez F. J. , Muñoz‐Caro C. 
Published: February 2005

AbstractThis work presents an analysis of the equivalence of MP2 and DFT (B3LYP functional) conformational populations. As a test case, we select three cholinergic agents (trans‐nicotine, acetylcholine, and the nicotinic analgesic ABT‐594), where the minima on the conformational energy hypersurfaces expand a large range of energies (∼0–30 kJ mol−1). From energetic and structural data obtained in vacuo at the MP2 and B3LYP/cc‐pVDZ levels, we build conformational partition functions, including the effect of the conformational kinetic energy and the rotovibrational coupling. Our results at a physiological temperature (37°C) show qualitative agreement in all cases. Quantitative agreement, however, is only found for trans‐nicotine and ABT‐594. In the first case, energy minima differ by <0.2 kJ mol−1. Therefore, the equivalence of structural results translates in the equivalence of the conformational distribution. For ABT‐594, the minima are separated by as much as 8.0 kJ mol−1, and the conformational energy determines the conformational distribution. In this case, the slight relative variation of conformational energy, between B3LYP and MP2, does not affect the population, since the secondary minima are high in energy and very low in population. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Direct Observation of the Growth Process of MgO Nanoflowers by a Simple Chemical Route
Authors: Fang Xiao‐Sheng , Ye Chang‐Hui , Zhang Li‐De , Zhang Jun‐Xi , Zhao Jian‐Wei , Yan Peng 
Published: February 2005

AbstractNovel flowerlike nanostructures consisting of MgO nanofibers were successfully synthesized by a simple chemical route with H2O at 950 °C in an Ar atmosphere. Various durations of heating gave different growth stages that led to varied product morphologies. The synthesized products were systematically studied by X‐ray powder diffraction, scanning electron microscopy, high‐resolution transmission electron microscopy, and energy‐dispersive X‐ray analysis. The results show that the nucleation and growth process of the nanoflowers seems to be a vapor–solid mechanism, and that the total heating time during the reaction process is a critical factor for the development of MgO nanoflowers. Initially, Mg particles formed on the Si substrate, followed by the formation of MgO clusters as nucleation centers on the magnesium melt surface and the nucleation of short MgO nanofibers, then growth of the MgO nanofibers occurred, and finally MgO nanoflowers were formed. Besides nanoflowers, novel hierarchical MgO nanostructures were also observed. These nanostructures may be used as three‐dimensional composite materials and as supports for other materials.
Modelling fault‐proneness statistically over a sequence of releases: a case study
Authors: Ohlsson Magnus C. , Andrews Anneliese Amschler , Wohlin Claes 
Published: January 2005

AbstractMany of today's software systems evolve through a series of releases that add new functionality and features, in addition to the results of corrective maintenance. As the systems evolve over time it is necessary to keep track of and manage their problematic components. Our focus is to track system evolution and to react before the systems become difficult to maintain. To do the tracking, we use a method based on a selection of statistical techniques. In the case study we report here that had historical data available primarily on corrective maintenance, we apply the method to four releases of a system consisting of 130 components. In each release, components are classified as fault‐prone if the number of defect reports written against them are above a certain threshold. The outcome from the case study shows stabilizing principal components over the releases, and classification trees with lower thresholds in their decision nodes. Also, the variables used in the classification trees' decision nodes are related to changes in the same files. The discriminant functions use more variables than the classification trees and are more difficult to interpret. Box plots highlight the findings from the other analyses. The results show that for a context of corrective maintenance, principal components analysis together with classification trees are good descriptors for tracking software evolution. Copyright © 2001 John Wiley & Sons, Ltd.
Performance evaluation of distributed‐antenna communications systems using beam‐hopping
Authors: Hu Honglin , Zhu Jinkang , Yang Lie‐Liang 
Published: February 2005

AbstractDigital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference especially in the direction of the transmitted beams, these directional jamming signals will severely degrade the system performance. In order to efficiently mitigate the interference of the directional jammers, in this contribution a beam‐hopping (BH) communications scheme is studied. In the BH communications scheme, only one pair of the beams is used for transmission and it hops from one to the next according to an assigned BH pattern. In this contribution, a range of expressions in terms of the average signal to interference plus noise ratio (SINR) performance have been derived, when both the uplink and downlink are considered. The average SINR performance of the BH scheme and that of the conventional single‐beam (SB) as well as multiple‐beam (MB) assisted beam‐processing schemes have been investigated. Our analysis and results show that the BH scheme is capable of efficiently combating the directional jamming, with the aid of utilizing the directional gain of the beams generated by both the transmitter and the receiver. Furthermore, the BH scheme is capable of reducing the intercept probability of the communications. Therefore, the BH scheme is suitable for communications when several distributed antenna arrays are available around a mobile. Copyright © 2005 John Wiley & Sons, Ltd.
Analysis and optimization of pilot‐symbol‐assisted M‐QAM for OFDM systems
Authors: Chen Jiming , Tang Youxi , Li Shaoqian 
Published: February 2005

AbstractOrthogonal frequency division multiplexing (OFDM) is very attractive for next generation high‐speed wireless communication because of its various advantages in lessening the severe effects of frequency‐selective fading. When using pilot symbol assisted (PSA) M‐ary quadrature amplitude modulation (M‐QAM) in OFDM systems, if the power of pilot is too low, the channel parameters cannot be accurately estimated, whereas, high pilot power will lead to less power left for data symbols under the condition that the total transmitted power is constrained to be a constant. In this paper, we present how pilot power affects the demodulation performance in Rayleigh fading propagation environments. Consequently, the pilot‐to‐data power ratio (PDR) is optimized analytically, and degradation of system performance due to inaccurate channel estimation is also evaluated. The theoretical and simulation results show that the optimum PDR is affected by the signal‐to‐noise ratio (SNR), Doppler frequency and interpolation size etc. When the optimum PDR is adopted for an OFDM system, the total transmission power will be minimal for certain bit error rate (BER) target. Copyright © 2005 John Wiley & Sons, Ltd.
Family dynamics, gender differences and educational attainment in Filipino adolescents
Authors: Hindin Michelle J. 
Published: February 2005

AbstractThe relationship between parenting style, marital relationships and subsequent educational attainment is explored among 1428 Filipino adolescents attending school in 1994 and 1096 attending school in 1999. Girls in households where their fathers physically abused their mothers were significantly less likely to complete primary school, and girls who reported parental arguments completed fewer grades. In contrast, girls in households where parents made decisions jointly were more likely to finish secondary school and attain more grades. Boys attained more education if they reported being close to their mothers. Boys with authoritative mothers attained more grades and were more likely to complete secondary school as compared to boys with neglectful mothers. In this context, marital relationships and parent–child relationships are important for understanding adolescent educational attainment.
Celecoxib and ketoprofen for pain management during tonsillectomy: A placebo‐controlled clinical trial
Authors: Nikanne Elina , Kokki Hannu , Salo Juha , Linna Timo‐Jussi 
Published: February 2005

OBJECTIVETo evaluate the efficacy and safety of celecoxib and ketoprofen in pain management during tonsillectomy in 120 patients.STUDY DESIGN AND SETTINGThe study was randomized, double‐blind, and placebo‐controlled with parallel groups. Sixty minutes before anesthesia induction and 12 hours after, the patients received a 200‐mg celecoxib, a 100‐mg ketoprofen, or a placebo capsule. After discharge, patients were prescribed either celecoxib or ketoprofen capsules to be taken every 12 hours.RESULTSDuring the first 24 hours, the need for rescue analgesic was less in the ketoprofen‐group (5 (1‐9)) doses (median (range)) than in the placebogroup (6 (1‐13)) (P = 0.021), but similar to the cele‐coxib‐group (5 (2‐14)). After discharge, the cessation of pain during eating occurred earlier in the celecoxib‐treated patients, after 10 (1‐17) days, than in the ketoprofen‐treated patients, after 12 (1‐21) days, (P = 0.008). One celecoxib‐treated patient and 6 ketoprofen‐treated patients (P = 0.013) needed electrocautery to stop postoperative bleeding.CONCLUSIONKetoprofen provided a better initial analgesic efficacy but after discharge the recovery with celecoxib was faster and the incidence of secondary hemorrhages was lower.SIGNIFICANCECelecoxib seems to be more effective and safe than ketoprofen for pain management after discharge in patients with tonsillectomy.
Indications for the Caldwell‐Luc approach in the endoscopic era
Authors: Barzilai Geva , Greenberg Elhanan , Uri Nechama 
Published: February 2005

OBJECTIVECaldwell and Luc described the Caldwell‐Luc operation more than 100 years ago as the surgical treatment for maxillary sinus disease. During the last decades less radical interventions using endoscopic approach have mainly replaced the classical procedures done for chronic and recurrent maxillary sinusitis.STUDY DESIGN AND SETTINGBetween 1991 and 2002, 62 patients had the Caldwell‐Luc approach for different indications.RESULTSTwenty (32%) patients had chronic sinusitis, 16 (26%) patients had inverted papilloma, 9 (15%) patients had suffered from nasal polyposis, 4 patients (6%) had dentigerous cyst, 4 (6%) patients had fungal ball, and 9 (15%) patients were operated for other indications.CONCLUSIONSThe use of this surgical approach is rational in cases of fungal disease and in endoscopic medial maxillectomy for treating inverted papilloma. In all other cases, the preferred approach should now be endoscopic.
A new instrument to expose the human larynx
Authors: Morgado Plínio Ferreira 
Published: February 2005

OBJECTIVETo present a nonwalled all‐detachable retractor that simultaneously exposes the mouth, pharynx, and larynx.STUDY DESIGN AND SETTINGThe proposed instrument is composed of a mouth‐gag with a set of 5 interchangeable angled tongue blades, and a pharyngeal lever that provides internal laryngo‐pharyngeal distension. Sixty‐five patients were submitted to tonsillectomy, adenoidectomy, and endolaryngeal surgery with the workspace provided by the manufactured scope.RESULTSProper exposure of the upper aerodigestive tract was achieved in all patients. Naked eye, varied endoscopes, and special curved instruments were used to examine, lase, and manipulate tissues. Bimanual surgery was possible due to self‐retaining adjustment and a clamp for endoscopes.CONCLUSION AND SIGNIFICANCEThis instrument allowed for an ample exposure from mouth to glottis in adults and children. Opposed to linear laryngoscopes in which the patient adapts to the instrument, its unique design adjusts to patients’ anatomy and to many clinical situations.
Management of congenital subglottic hemangioma: Trends and success over the past 17 years
Authors: Bitar Mohamed A. , Moukarbel Roger V. , Zalzal George H. 
Published: February 2005

OBJECTIVETo evaluate the success and complications of various treatment options of congenital subglottic hemangioma.STUDY DESIGN AND SETTINGSReported cases were grouped by treatment modalities and corresponding outcome evaluated.RESULTSFrom 1986 through 2002, 372 patients were reported in 28 series. Carbon dioxide laser had 88.9% success rate yet 5.5 % significant subglottic stenosis. It shortened the tracheotomy duration by 13.7 months. Corticosteroids were not that beneficial (useful in only 24.5%) with 12.9% side effects. Intralesional corticosteroids were successful in 86.4% with 5.6% complication rate. Surgical excision (as young as 2.5 months), was useful in 98% with 10% complication rate, using cartilage grafts in 34%. Other modalities were less popular.CONCLUSIONTreatment should be individualized. Guidelines are suggested. Priority is given to secure the airways. The CO2 laser is useful when used cautiously. Steroids may be beneficial. Excision is for stubborn cases.
The effect of polysomnography on pediatric adenotonsillectomy postoperative management
Authors: Rieder Anthony A. , Flanary Valerie 
Published: February 2005

OBJECTIVEWe retrospectively investigated the effect and predictability of preoperative polysomnography (PSG) on the postoperative course of younger pediatric patients undergoing adenotonsillectomy.STUDY DESIGN AND SETTINGA retrospective chart review was performed for patients 3 years of age and younger who had undergone adenotonsillectomy between July 1997 and July 2002 at the Children's Hospital of Wisconsin.RESULTSTwo hundred eighty‐two patients were identified. Forty‐three patients had preoperative PSG. No correlation between the severity of PSG results and postoperative course was identified.CONCLUSIONSThe role of PSG in upper airway obstruction and OSA remains controversial. This study suggests that although the complication rate may be higher in this younger population, these complications do not appear to have a large impact on their length of stay.SIGNIFICANCEThis study suggests that the 3‐years‐and‐younger group, in the absence of other comorbidities, can safely undergo adenotonsillectomy without undergoing preoperative PSG. EBM raing: C.
Effects of piperine, the pungent component of black pepper, at the human vanilloid receptor (TRPV1)
Authors: McNamara Fergal N , Randall Andrew , Gunthorpe Martin J 
Published: February 2005

We have characterised the effects of piperine, a pungent alkaloid found in black pepper, on the human vanilloid receptor TRPV1 using whole‐cell patch‐clamp electrophysiology.
Piperine produced a clear agonist activity at the human TRPV1 receptor yielding rapidly activating whole‐cell currents that were antagonised by the competitive TRPV1 antagonist capsazepine and the non‐competitive TRPV1 blocker ruthenium red.
The current–voltage relationship of piperine‐activated currents showed pronounced outward rectification (25±4‐fold between −70 and +70 mV) and a reversal potential of 0.0±0.4 mV, which was indistinguishable from that of the prototypical TRPV1 agonist capsaicin.
Although piperine was a less potent agonist (EC50=37.9±1.9 μM) than capsaicin (EC50=0.29±0.05 μM), it demonstrated a much greater efficacy (approximately two‐fold) at TRPV1.
This difference in efficacy did not appear to be related to the proton‐mediated regulation of the receptor since a similar degree of potentiation was observed for responses evoked by piperine (230±20%, n=11) or capsaicin (284±32%, n=8) upon acidification to pH 6.5.
The effects of piperine upon receptor desensitisation were also unable to explain this effect since piperine resulted in more pronounced macroscopic desensitisation (t1/2=9.9±0.7 s) than capsaicin (t1/2>20 s) and also caused greater tachyphylaxis in response to repetitive agonist applications.
Overall, our data suggest that the effects of piperine at human TRPV1 are similar to those of capsaicin except for its propensity to induce greater receptor desensitisation and, rather remarkably, exhibit a greater efficacy than capsaicin itself. These results may provide insight into the TRPV1‐mediated effects of piperine on gastrointestinal function.

British Journal of Pharmacology (2005) 144, 781–790. doi:10.1038/sj.bjp.0706040
Inhibition of the human two‐pore domain potassium channel, TREK‐1, by fluoxetine and its metabolite norfluoxetine
Authors: Kennard Louise E , Chumbley Justin R , Ranatunga Kishani M , Armstrong Stephanie J , Veale Emma L , Mathie Alistair 
Published: February 2005

Block of the human two‐pore domain potassium (2‐PK) channel TREK‐1 by fluoxetine (ProzacR) and its active metabolite, norfluoxetine, was investigated using whole‐cell patch‐clamp recording of currents through recombinant channels in tsA 201 cells.
Fluoxetine produced a concentration‐dependent inhibition of TREK‐1 current that was reversible on wash. The IC50 for block was 19 μM. Block by fluoxetine was voltage‐independent. Fluoxetine (100 μM) produced an 84% inhibition of TREK‐1 currents, but only a 31% block of currents through a related 2‐PK channel, TASK‐3.
Norfluoxetine was a more potent inhibitor of TREK‐1 currents with an IC50 of 9 μM. Block by norfluoxetine was also voltage‐independent.
Truncation of the C‐terminus of TREK‐1 (Δ89) resulted in a loss of channel function, which could be restored by intracellular acidification or the mutation E306A. The mutation E306A alone increased basal TREK‐1 current and resulted in a loss of the slow phase of TREK‐1 activation.
Progressive deletion of the C‐terminus of TREK‐1 had no effect on the inhibition of the channel by fluoxetine. The E306A mutation, on the other hand, reduced the magnitude of fluoxetine inhibition, with 100 μM producing only a 40% inhibition.
It is concluded that fluoxetine and norfluoxetine are potent inhibitors of TREK‐1. Block of TREK‐1 by fluoxetine may have important consequences when the drug is used clinically in the treatment of depression.

British Journal of Pharmacology (2005) 144, 821–829. doi:10.1038/sj.bjp.0706068
An Absolute Determination of Resistance Based on a Calculable Standard of Capacitance
Authors: A M Thompson  
Published: February 2005

A determination of the NSL unit of resistance based on standards of length and frequency has been made. A cylindrical cross-capacitor, for which the change in capacitance for a measured change in length may be calculated very precisely, is used to calibrate a number of small fixed capacitors (1/6 or 1/4 pF). AC bridge techniques are used to build up to 10 nF and also to measure the resistance of a 10 kΩ resistor in terms of this capacitance and a measured frequency (ω = 104). DC measurements are used to relate the 10 kΩ resistor to the Laboratory's 1 Ω standard resistors.The estimated uncertainty in the measurements is 2 in 107but the accuracy of the determination is limited to ± 7 in 107because of the uncertainty in the speed of light. Mean values, derived from a number of determinations, and corresponding to the times of the BIPM international comparisons, areJan. 1964ΩNSL= 1 Ω - 3.58 μΩFeb. 1967ΩNSL= 1 Ω - 3.80 μΩ.The standard deviation of a series of determinations was 0.06 μΩ.
Poets House Showcase 2004: suggested titles
Authors: Kindseth Tim , Romanos Michael 
Published: February 2005

PurposeThis annotated list represents a selection of outstanding poetry titles published in the USA in 2003 and the early part of 2004.Design/methodology/approachThe authors selected the titles in this list from the 2,100 titles received for the 2004 Poetry Publications Showcase at Poets House in New York City, held in April 2004.FindingsThe authors selected titles for this list that would be both accessible and challenging to library users.Originality/valueThis list can be used as a guide to collection development for contemporary poetry.