bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perfusion precision in bolus‐tracking MRI: Estimation using the wild‐bootstrap method
Authors: Calamante Fernando , Connelly Alan 
Published: December 2008

AbstractBolus‐tracking MRI involves the bolus injection of contrast agent, and the resultant concentration time course can be used to calculate perfusion by deconvolution analysis. However, most deconvolution methods do not provide a measure of precision. Precision could be estimated from many repeated measurements; however, this would involve a series of successive bolus injections, which is not a feasible option in practice due to contrast agent dose constraints. In this work, a method is presented to estimate precision in bolus‐tracking MRI using the wild‐bootstrap method. This approach is able to estimate the uncertainty in perfusion measurements from the data acquired during a single bolus of contrast agent injection. The methodology was assessed using numerical simulations and applied to real data with a range of image qualities. The method is shown to provide useful estimates of precision, and the results from real data were consistent with the underlying MRI data quality. The methodology provides an important complementary tool in clinical and research applications of bolus‐tracking MRI. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.
Initial results of cardiac imaging at 7 tesla
Authors: Snyder C.J. , DelaBarre L. , Metzger G.J. , van de Moortele P.‐F. , Akgun C. , Ugurbil K. , Vaughan J.T. 
Published: December 2008

AbstractThis work reports preliminary results from the first human cardiac imaging at 7 Tesla (T). Images were acquired using an eight‐channel transmission line (TEM) array together with local B1 shimming. The TEM array consisted of anterior and posterior plates closely positioned to the subjects' thorax. The currents in the independent elements of these arrays were phased to promote constructive interference of the complex, short wavelength radio frequency field over the entire heart. Anatomic and functional images were acquired within a single breath hold to reduce respiratory motion artifacts while a vector cardiogram (VCG) was used to mitigate cardiac motion artifacts and gating. SAR exposure was modeled, monitored, and was limited to FDA guidelines for the human torso in subject studies. Preliminary results including short‐axis and four‐chamber VCG‐retrogated FLASH cines, as well as, short‐axis TSE images demonstrate the feasibility of safe and accurate human cardiac imaging at 7T. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.
Increasing spatial coverage for high‐resolution functional MRI
Authors: Hu Yanle , Glover Gary H. 
Published: December 2008

AbstractFor high‐resolution functional MRI (fMRI) studies, one of the major challenges is limited spatial coverage, which results because of the tradeoffs between temporal resolution and covering more k‐space. Given the same temporal resolution, fewer slices can be collected for high‐resolution fMRI. If the number of slices is not large enough to cover all regions of interest, additional scans may become necessary, which increases both the total scan time and the complexity of interpreting data. In this work, we propose a method that combines the undersampled 3D stack‐of‐spirals acquisition method with the UNFOLD technique to significantly increase the spatial coverage for high‐resolution fMRI. Undersampling allows more slices to be fit into a given temporal resolution. The signal‐to‐noise ratio (SNR) drop associated with undersampling can be compensated by the increase in the excited volume in 3D acquisitions. Theoretical analysis shows that although there is a negligible increase in temporal coherence due to spectral filtering in the UNFOLD technique, twice the spatial coverage can be achieved given the same total scan time and similar quality of activation maps, which was confirmed by experiments on normal subjects. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.
A domain decomposition strategy to efficiently solve structures containing repeated patterns
Authors: Gosselet P. , Rixen D. J. , Rey C. 
Published: December 2008

AbstractThis paper presents a strategy for the computation of structures with repeated patterns based on domain decomposition and block‐Krylov solvers. It can be seen as a special variant of the FETI method. We propose using the presence of repeated domains in the problem to compute the solution by minimizing the interface error on several directions simultaneously. The method not only drastically decreases the size of the problems to solve but also accelerates the convergence of interface problem for nearly no additional computational cost and minimizes expensive memory accesses. The numerical performances are illustrated on some thermal and elastic academic problems. Copyright © 2008 John Wiley & Sons, Ltd.
Adverse drug reactions in patients in an Iranian department of internal medicine
Authors: Pourseyed Sara , Fattahi Fatemeh , Pourpak Zahra , Gholami Keirollah , Shariatpanahi Seyed Shamsa , Moin Athar , Kazemnejad Anoushirvan , Moin Mostafa 
Published: December 2008

AbstractPurposeAdverse drug reactions (ADRs) are a major cause of hospital admission and inpatient morbidity. The department of internal medicine is not an exception to this issue. This study was performed to determine the nature and frequency of ADRs in an internal medicine ward in Iran.MethodsThis survey was a prospective observational study based on admissions of 400 patients to the internal medicine ward over a 15‐week period. Patients were intensively followed in order to assess any ADR as a cause of admission or occurring during hospitalization. Any suspicious ADR was confirmed by a pharmacist/pharmacologist.ResultsThere were 47 patients of 400 patients (11.75%) that experienced at least one ADR. ADR leading to the admission was seen in seven cases (1.75%) and in 40 (10%) it occurred during hospitalization. ADRs were identified as preventable reactions in 50% of cases and as predictable in 94.3%. The severity of 18.6% of the ADRs was identified as mild, 62.9% as moderate, 14.3% as severe and 4.3% as lethal. Gastrointestinal system disorders (44.3%) represented the most frequent ADRs. The therapeutic groups that most commonly associated with suspected ADRs were antineoplastic, immunosuppressive and medicines used in palliative care (54.8%).ConclusionsADRs are common among hospitalized patients in department of internal medicine and can be severe and even lethal. Since most ADRs occurred during hospitalization in studied patients and half of them were preventable, prevention strategies should be considered in hospitals. Also, our findings confirmed the role of hospital pharmacists in the reducing ADRs. Copyright © 2008 John Wiley & Sons, Ltd.
Drug information for patients—an update of long‐term results: type of enquiries and patient characteristics
Authors: Huber Martin , Kullak‐Ublick Gerd A. , Kirch Wilhelm 
Published: December 2008

AbstractPurposeTo analyse the type of enquiries to a drug information service in Germany, available exclusively for patients.MethodsSociodemographic characteristics of the patients who used the service, number and kind of drugs taken, existing diseases, reasons for enquiry as well as type of answers provided were recorded. For the present evaluation we analysed all enquiries to the service from August 2001 to January 2007.ResultsA total of 5587 enquiries were received. 5013 enquiries from 4091 patients were available for further analysis in detail. The patient group using the service most frequently were women between 61 and 70 years (23.3%). 1457 enquiries (29.1%) were made by patients who had contacted the information service once or several times before. The group of drugs most often asked about were cardiovascular drugs (33.4%), followed by drugs for the nervous system (16.2%) and for the alimentary tract and metabolism (12.4%). On average, each patient had questions about 2.6 (median 1; 1–22) drugs simultaneously. Common reasons for contacting the service were adverse drug reactions (22.1%), the need for general information about the drug (19.9%), information about therapy (12.4%) and drug interactions (10.2%).ConclusionsA lot of patients need additional information about their medication, especially concerning drug groups that are frequently prescribed. The presented drug information service can be one helpful tool to counteract these information deficits and to increase patients' knowledge about their drugs. Copyright © 2008 John Wiley & Sons, Ltd.
Fear of recurrence and psychological distress in head and neck cancer patients and their carers
Authors: Hodges Laura J. , Humphris Gerry M. 
Published: December 2008

AbstractBackground: Fear of recurrence (FOR) has been increasingly recognised as an issue of significant burden for most cancer patients, and has been associated with psychological morbidity and reduced quality of life. More recently, the impact of recurrence fears has been indicated in the families of cancer patients. However, there has been a lack of prospective research.Aim: To systematically examine distress and illness concerns among patient–carer dyads.Methods: A multi‐centre prospective study of head and neck cancer patients and their carers (patients, n=101; carers, n=101), surveyed at two time‐points following diagnosis.Results: Carers recorded higher recurrence concerns on average than the patient group (p<0.001). A predictive path model of patient and carer self‐reports of distress and FORs was explored, with an excellent overall fit of the final model (χ2=15.4, df=12, p=0.22, Comparative Fit Index (CFI)=0.994, Root Mean Square Estimate of Approximation (RMSEA)=0.053).Conclusions: The preliminary results establish that early fears and distress within individuals govern later reports on these same attributes, but that there is some weak evidence of influence from one attribute to another within and across individuals in the dyad. Future prospective dyadic research is warranted to ascertain the level of these fears over an extended time and their relationship to patient and carer adaptation. Intervention may be needed to reduce this disease concern to a manageable level at an early stage of the illness trajectory. Copyright © 2008 John Wiley & Sons, Ltd.
Learning from organizational incidents: Resilience engineering for high‐risk process environments
Authors: Huber Stefanie , van Wijgerden Ivette , de Witt Arjan , Dekker Sidney W.A. 
Published: December 2008

AbstractFor years, safety improvements have been made by evaluating incident reports and analyzing errors and violations. Current developments in safety science, however, challenge the idea that safety can meaningfully be seen as the absence of errors or other negatives. Instead, the question becomes whether a company is aware of positive ways in which people, at all level of the organization, contribute to the management and containment of the risks it actually faces. The question, too, is whether the organization has the adaptive capacity necessary to respond to the changing nature of risk as operations shift and evolve. This article presents the results of a resilience engineering safety audit conducted on a chemical company site. An interdisciplinary team of seven researchers carried out 4 days of field studies and interviews in several plants on this site. This company enjoyed an almost incident‐free recent history but turned out to be ill‐equiped to handle future risks and many well‐known daily problems. Safety was often borrowed from to meet acute production goals. Organizational learning from incidents was fragmented into small organizational or production units without a company‐wide learning. We conclude that improving safety performance hinges on an organization's dynamic capacity to reflect on and modify its models of risk as operations and insight into them evolve, for example, as they are embodied in safety procedures and policies. © 2008 American Institute of Chemical Engineers Process Saf Prog 2009
Application of the simple model for f–d transition to assignment of 4f–5d excitation spectra of Yb3+ doped in crystals
Authors: Wang Da‐Jun , Wang Jue , Chen Tao , Ma Chong‐Geng , Yin Min , Xia Shang‐Da 
Published: December 2008

AbstractThe simple model for 4f–5d transitions proposed by Duan and Reid is successfully applied to the simulation of the 4f–5d spectra of Yb3+ doped in crystals, where the parameterized energy matrix elements and the coefficients contained in f–d transition matrix elements have been obtained and tabulated. As an example, these data tables have been used to explain the absorption spectra of Yb3+ doped in crystal CaF2. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density‐functional based tight‐binding modelling of ZnO structures
Authors: Fisker Christian , Pedersen Thomas G. 
Published: December 2008

AbstractA self‐consistent charge density‐functional based tight‐binding (SCC‐DFTB) parametrisation for structural optimization and electronic properties of zinc oxide is presented. Repulsive potentials are obtained from the ZnO wurtzite geometry and a thin nanowire and applied to the bulk rock salt phase, a (0001) oriented slab and nanowires of different sizes. The parametrisation is shown to reproduce geometries in agreement with DFT calculations.A different set of parameters is generated for electronic calculations giving band structures with a bulk band gap of 3.3 eV and a strong split‐off of the d‐bands in agreement with experiments. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Single quantum dot controlled gain modulation in high‐Q micropillar lasers
Authors: Reitzenstein S. , Böckler C. , Bazhenov A. , Gorbunov A. , Münch S. , Löffler A. , Kamp M. , Kulakovskii V. D. , Forchel A. 
Published: December 2008

AbstractWe present single quantum dot lasing effects in optically pumped high quality (Q) micropillar cavities. The micropillar cavities are realized by means of high resolution electron beam lithography and plasma etching on planar microcavity structures grown by molecular beam epitaxy. We observe lasing action for micropillars with a diameter as small as 1.0 μm containing on average less than 80 QDs in the active layer. Pronounced single quantum dot (QD) controlled lasing effects are observed by tuning a single QD exciton on resonance with the lasing mode. When lasing action is due to the contribution of an ensemble of QDs, photon autocorrelation studies of the emitted photons reveal a transition from thermal light to coherent light near threshold pump power. In contrast, single QD gain modulation which helps to lower the threshold pump power of a 1.6 μm micropillar by a factor of two, is reflected in non‐classical photon antibunching up to about two times the on‐resonance threshold power. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical transport phenomena in magnesium‐doped p‐type GaN
Authors: Konczewicz Leszek , Litwin‐Staszewska Elżbieta , Contreras Sylvie , Piotrzkowski Ryszard , Dmowski Lesław 
Published: December 2008

AbstractIn this paper we present the resistivity and Hall‐effect measurements on p‐type GaN doped with Mg. The experiments were carried out as a function of hydrostatic pressure up to 1200 MPa in the temperature range 260–400 K. Both bulk GaN crystals as well as GaN:Mg epilayers were studied. In the investigated samples the decrease of resistivity and increase of hole concentration under pressure was observed. Such a behavior, which is contrary to the n‐type material, strongly suggests a decrease of the ionization energy of Mg acceptor (Ea = 183 meV) with pressure. This shift is very weak, less than –2 meV/GPa. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphology and wetting layer properties of InAs/GaAs nanostructures
Authors: Zhao Chao , Chen Yonghai , Xu Bo , Tang Chenguang , Wang Zhanguo 
Published: December 2008

AbstractIn this work, we present the growth of InAs rings by droplet epitaxy. A complete process from the rings formation to their density saturation has been demonstrated. A morphological evolution with the varying of the indium deposition amount has been clearly observed. Our results indicate that there is a critical deposition amount (∼1.1 ML) for the indium to form InAs dots before droplets form; there is also a critical deposition amount (∼1.4 ML) to form InAs rings, but it is caused by the formation of droplets as the deposition amount increases. The density of the rings saturates when the deposition amount exceeds ∼3.3 ML, because the adsorbed indium atoms block sites for further adsorption and the following supplied In only contributes to the size increase of In droplets. Still, as the In deposition amount increases, we can find coupled quantum rings. Moreover, the wetting layer properties of these structures are studied by reflectance difference spectroscopy, which shows a complicated evolution with the In amount. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exchange interaction tuned by electric field in quantum dots
Authors: Kwaśniowski Artur , Adamowski Janusz 
Published: December 2008

AbstractThe effect of external electric field on exchange interaction has been studied by a configuration interaction method for electrons localized in double quantum dots. We model the confinement potential by the twocenter power‐exponential function, with different range and “softness”, which allows us to investigate various types of quantum dots. We have found that – for quantum dots separated by a sufficiently thick barrier – the exchange energy rapidly increases if the electric field increases, for intermediate electric field reaches a maximum, and decreases to zero at high electric fields. We have discussed the physical reasons of this nonmonotonic dependence. The present results show that the exchange coupling between the electrons in quantum dots can be tuned by applying the external electric field (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of coupled GaAs quantum dots and their optical properties
Authors: Kim Jong Su , Song Jin Dong , Byeon Clare C. , Kang Hoonsoo , Jeong Mun Seok , Cho Nam Ki , Park Sung Jun , Choi Won Jun , Lee Jung Il , Kim Jin Soo , Leem Jae‐Young , Yim Sang‐Youp , Ko Do‐Kyeong , Lee Jongmin 
Published: December 2008

AbstractThe coupled GaAs quantum dot molecules (QDMs), which were laterally coupled along the [1$ \bar 1 $0] direction, were formed by droplet epitaxy. The optical properties of QDMs were investigated by femtosecond laser excited photoluminescence (PL) measurement. When the laser polarization is parallel to [1$ \bar 1 $0] direction on the QDMs, the main PL peak is red‐shifted by 55 meV from the PL peak measured with the laser polarization parallel to [110] direction. By changing the excitation power, we found that the emission wavelength of the QDMs was strongly depending on the excitation laser polarization. From this result, we carefully suggested that the confined states in QDMs could be tuned by optical field. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deformation‐induced microstructural heterogeneity in monolithic Zr44Ti11Cu9.8Ni10.2Be25 bulk metallic glass
Authors: Lee Min Ha , Lee Jin Kyu , Kim Kyung Tae , Thomas Jürgen , Das Jayanta , Kühn Uta , Eckert Jürgen 
Published: December 2008

AbstractWe present investigations on the development of microstructural inhomogeneity introduced by simple room temperature deformation for a typical bulk metallic glass (Zr44Ti11Cu9.8Ni10.2Be25). The experimental evidence (e.g., transmission electron microscopy, electron energy dispersive X‐ray spectroscopy and density measurements) clearly supports that an inhomogeneous glassy structure can be produced during deformation in the bulk metallic glass, that does not depend on a specific pinpointed chemical composition. The micrometer‐sized structural inhomogeneity in the monolithic bulk metallic glass originates from deformation due to the introduction of a high concentration of free volume in the glassy phase without significant change in the local chemical composition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design schemes for the X̄ control chart
Authors: Schoonhoven Marit , Riaz Muhammad , Does Ronald J. M. M. 
Published: December 2008

AbstractThis paper studies several issues regarding the design of the X̄ control chart under normality. Different estimators of the standard deviation are considered and the effect of the estimator on the performance of the control chart is investigated. Furthermore, the choice of the factor used to get accurate control limits for moderate sample sizes is addressed. The paper gives an overview on the performance of the charts by studying different characteristics of the run length distribution, both in the in‐control and in the out‐of‐control situation. Copyright © 2008 John Wiley & Sons, Ltd.
Generalized confidence intervals for assessing process capability of multiple production lines
Authors: Wu Chien‐Wei , Shu Ming‐Hung , Cheng Feng‐Tsung 
Published: December 2008

AbstractProcess capability indices (PCIs) have become popular as unit‐less measures on whether a process is capable of reproducing items meeting the quality requirement. A reliable approach for testing process capability is to establish an interval estimate, for which we can assert that it contains the true PCI value with a reasonable degree of certainty. However, the construction of such an interval estimate is not trivial, since the distribution of the commonly used Cpk index involves unknown parameters. In this paper, we adopt the concept of generalized confidence intervals and generalized pivotal quantities to derive the generalized lower confidence bounds for providing critical information on process performance. Two practical applications in the area of process capability were considered, they include (i) assessing whether a process under investigation is capable and (ii) providing the lowest performance of the manufacturing processes from several production lines or several suppliers for quality assurance. The applicability of the derived results is also illustrated with examples. Copyright © 2008 John Wiley & Sons, Ltd.
3D‐QSAR Studies on DATAs and DAPYs for HIV‐RT Inhibitors using CoMFA and CoMSIA Approaches
Authors: Park Hyung Yeon , Ju Sun Mi , Lee Do Young , Zhang Hui , Kim Chan Kyung 
Published: December 2008

AbstractStructure‐based Quantitative Structure–Activity Relationship (QSAR) studies were performed on the Human Immunodeficiency Virus Reverse Transcriptase (HIV‐RT) inhibitors with Diaryltriazines (DATAs) and Diarylpyrimidines (DAPYs) using Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) implemented in the SYBYL software packages. From the X‐ray structure of dapivirine, 38 training set molecules were sketched and minimized using the MMFF94 force field. In structure‐based QSAR, all the HIV‐RT complexes were subjected to subset minimization and aligned against a fixed point of the enzyme. The best CoMFA and CoMSIA results presented cross‐validated values (q2) of 0.640 and 0.663, and non‐cross‐validated values (r2) of 0.976 and 0.932, respectively. Contour map analysis enables the identification of crucial interactions between the enzyme and inhibitors, which can be used further to design new HIV‐RT inhibitors.