bluuebunny/crossref_metadata_2025_split huggingface dataset:
Errors in laparoscopic surgery
Authors: Gaar Earl 
Published: November 2004

AbstractLaparoscopic surgery is the most significant advancement in the field of surgery over the past 15 years. This minimal access approach has been widely embraced and adopted to many common operations. Demonstrated benefits include decreased post‐operative pain, shorter lengths of in‐patient hospitalization, increased patient acceptance, and a more rapid return to gainful employment. With its ever‐growing popularity, it has become fertile ground for civil litigation, ranking along with birth injuries and failure to diagnose cancer. A brief synopsis of the history of its evolution is presented along with general and specific comments concerning potential errors as they relate to specific common operations which are commonly done utilizing this technique. J. Surg. Oncol. 2004;88:153–160. © 2004 Wiley‐Liss, Inc.
Brain perfusion territory imaging applying oblique‐plane arterial spin labeling with a standard send/receive head coil
Authors: Werner Richard , Alfke Karsten , Schaeffter Tobias , Nabavi Arya , Mehdorn H. Maximilian , Jansen Olav 
Published: November 2004

AbstractA new method for the selective spin labeling of left‐ or right‐sided supplying arteries of the brain without the need for additional RF coils is demonstrated. A clinical 1.5 T scanner was used. The spatial selectivity of the labeling process is based on the limited coverage of the excitation field of a standard send/receive head coil together with an oblique positioning of the labeling plane. A computer simulation was used to optimize key labeling parameters under the condition of laminar flow. The validity of the computer model results was confirmed by MRI measurements with a flow model. For human studies, a double‐inversion continuous arterial spin labeling (CASL) sequence was modified to allow for arbitrary positioning of the labeling plane. The obtained perfusion‐weighted images showed a clear delineation of the perfusion territories of the selected arteries in the anterior circulation of the brain and good gray/white matter contrast. Magn Reson Med 52:1443–1447, 2004. © 2004 Wiley‐Liss, Inc.
4 T actively detunable transmit/receive transverse electromagnetic coil and 4‐channel receive‐only phased array for 1H human brain studies
Authors: Avdievich Nikolai I. , Hetherington Hoby P. 
Published: November 2004

AbstractThe design and construction of a 4 T transverse electromagnetic (TEM) transmit/receive head coil and a four‐channel phased array receive‐only RF system are described. To enable both high‐resolution imaging of the entire brain and high‐resolution spectroscopic imaging, active PIN diode decoupling was used in both the TEM resonator and each surface coil in the array. This configuration allows for both transmission and reception from the volume coil as well as reception from the phased array. The surface coils were decoupled by overlapping the coils and using preamplifier decoupling. Since at high frequencies construction of a lumped element matching quarter wavelength transformer, an important component of the preamplifier decoupling, becomes difficult, a transmission line approach was used. The system was tested and compared to a TEM volume transmit/receive head coil. A four‐ to sixfold improvement in signal‐to‐noise ratio from the sensitive volume of the array was achieved. Magn Reson Med 52:1459–1464, 2004. © 2004 Wiley‐Liss, Inc.
POCSENSE: POCS‐based reconstruction for sensitivity encoded magnetic resonance imaging
Authors: Samsonov Alexei A. , Kholmovski Eugene G. , Parker Dennis L. , Johnson Chris R. 
Published: November 2004

AbstractA novel method for iterative reconstruction of images from undersampled MRI data acquired by multiple receiver coil systems is presented. Based on Projection onto Convex Sets (POCS) formalism, the method for SENSitivity Encoded data reconstruction (POCSENSE) can be readily modified to include various linear and nonlinear reconstruction constraints. Such constraints may be beneficial for reconstructing highly and overcritically undersampled data sets to improve image quality. POCSENSE is conceptually simple and numerically efficient and can reconstruct images from data sampled on arbitrary k‐space trajectories. The applicability of POCSENSE for image reconstruction with nonlinear constraining was demonstrated using a wide range of simulated and real MRI data. Magn Reson Med 52:1397–1406, 2004. © 2004 Wiley‐Liss, Inc.
New approach for correcting distortions in echo planar imaging
Authors: Zeng Huairen , Gatenby J. Christopher , Zhao Yansong , Gore John C. 
Published: November 2004

AbstractA new method is described that can correct the distortions due to multiple off‐resonance effects in echo planar imaging, including those caused by B0 field inhomogeneities, eddy currents, and gradient waveform imperfections. The proposed method uses a phase encoded acquisition and is as effective as the method of Chen and Wyricz (Chen and Wyricz, Magn Reson Med 1999;41:1206–1213) in correcting for distortions. Unlike Chen and Wyricz's approach, this new method works directly in distorted space and requires fewer scans. It also avoids the difficulties of phase unwrapping inherent in field mapping methods. Results using this new method with phantoms and human head scans at 3.0 T demonstrate the efficacy of the method in correcting distortions in both spin echo echo planar imaging (EPI) and gradient echo EPI. Magn Reson Med 52:1373–1378, 2004. © 2004 Wiley‐Liss, Inc.
Rapid measurement of pulse wave velocity via multisite flow displacement
Authors: Shao Xianzhi , Fei Ding‐yu , Kraft Kenneth A. 
Published: November 2004

AbstractA MR method is presented for measuring pulse wave velocity (PWV) and its application to assessing stiffness in the human thoracic aorta. This one‐dimensional (1D) flow displacement method applies a single RF comb excitation to the vessel, followed by an oscillating frequency encoding gradient, each oscillation providing a 1D projection of the vessel, enabling one to track fluid motion. The currently implemented sequence excites nine slices within a 20‐cm length of vessel and has a temporal resolution of 2.03 msec and a total acquisition time of 140 msec. Offline‐reconstructed position‐versus‐time plots show curvilinear flow displacement trajectories corresponding to fluid motion at each of the excitation positions. The PWV can be reliably calculated by curve‐fitting these trajectories to a model. In vitro studies using compliant tubes demonstrate no significant difference between results obtained using this method and those directly obtained using pressure transducers. Compared to another MR method previously developed in our laboratory, the proposed method displays improved temporal resolution and enhanced ability to extract PWV from vessels exhibiting low peak flow velocity. Preliminary data suggest that this method is feasible for in vivo application and may provide a more accurate estimation of aortic wave velocity among subjects exhibiting low peak flow velocity, such as the elderly or those with impaired cardiac function. Magn Reson Med 52:1351–1357, 2004. © 2004 Wiley‐Liss, Inc.
Comparison of arterial spin labeling and first‐pass dynamic contrast‐enhanced MR imaging in the assessment of pulmonary perfusion in humans: The inflow spin‐tracer saturation effect
Authors: Lin Yi‐Ru , Wu Ming‐Ting , Huang Teng‐Yi , Tsai Shang‐Yueh , Chung Hsiao‐Wen , Mai Vu M. , Chen Cheng‐Yu , Pan Huay‐Ben 
Published: November 2004

AbstractThe flow‐sensitive alternating inversion recovery (FAIR) and the first‐pass dynamic contrast‐enhanced MR imaging (CE‐MRI) techniques have both been shown to be effective in the assessment of human pulmonary perfusion. However, no comprehensive comparison of the measurements by these two methods has been reported. In this study, healthy adults were recruited, with FAIR and CE‐MRI performed for an estimation of the relative pulmonary blood flow (rPBF). Regions of interest were encircled from the right and left lungs, with right‐to‐left rPBF ratios calculated. Results indicated that, on posterior coronal slices, the rPBF ratios obtained with the FAIR technique agreed well with CE‐MRI measurements (mean difference = −0.02, intraclass correlation coefficient RI = 0.78, 95% confidence interval = [0.67, 0.86]). On middle coronal slices, however, FAIR showed a substantially lower rPBF by up to 43% in the right lung compared with CE‐MRI (mean difference = −0.38, RI = 0.34, 95% confidence interval = [−0.09, 0.68]). The location‐dependent discrepancy between measurements by FAIR and CE‐MRI methods is attributed to tracer saturation effects of arterial inflow when the middle coronal slice contains the in‐plane‐oriented right pulmonary artery, whereas the left lung rPBF is less affected due to oblique orientation of the left pulmonary artery. Intrasequence comparison on additional subjects using FAIR at different slice orientations supported the above hypothesis. It is concluded that FAIR imaging for pulmonary perfusion in the coronal plane provides equivalent rPBF information with CE‐MRI only in the absence of tracer saturation effects; hence, FAIR should be carefully exercised to avoid misleading interpretations. Magn Reson Med 52:1291–1301, 2004. © 2004 Wiley‐Liss, Inc.
Experience with chemoreduction and focal therapy for intraocular retinoblastoma in a developing country
Authors: Chantada Guillermo L. , Fandiño Adriana C. , Raslawski Elsa C. , Manzitti Julio , de Dávila Maria T.G. , Casak Sandra J. , Scopinaro Marcelo J. , Schvartzman Enrique 
Published: November 2004

AbstractBackgroundChemoreduction is used for the treatment of retinoblastoma in industrialized nations; however, there are fewer data from developing countries. Before the implementation of this program, radiotherapy was used in almost all preserved eyes.MethodsRetrospective evaluation from 1995 to 2001 at the Hospital Garrahan (Argentina). Carboplatin 18.7 mg/kg/day 1 and vincristine (0.05 mg/kg/day 1) were offered to patients with Reese–Ellsworth (RE) groups I–III and all unilateral cases. Etoposide (3.3 mg/kg/day 1 and 2) was added for groups IV and V. The number of cycles was tailored according to response.ResultsFifty‐eight patients (78 eyes) were evaluated (39 bilateral, 19 unilateral). With a median follow‐up of 47 months, 40 patients had unilateral enucleation, 14 were not enucleated, and 4 had bilateral enucleation. Nineteen patients had unilateral initial enucleation. Eye preservation at 5 years was: RE groups I–III (n = 24 eyes), 0.9 (SE: 0.095) IV–V (n = 54), 0.45 (SE 0.07). Patients received a median of four cycles of chemotherapy. Acute toxicity was mild. External beam radiotherapy was avoided in 41% of eyes with groups I–III. Etoposide was avoided in 24 patients. Two patients died of metastasis. No secondary malignancy occurred.ConclusionsCompared to our previous experience, eye preservation was better and even though less radiotherapy was used, it was prescribed more often than currently recommended in eyes with less advanced disease because of limited availability of sophisticated local therapy. © 2004 Wiley‐Liss, Inc.
Interaction interfaces of protein domains are not topologically equivalent across families within superfamilies: Implications for metabolic and signaling pathways
Authors: Rekha N. , Machado S.M. , Narayanan C. , Krupa A. , Srinivasan N. 
Published: November 2004

AbstractUsing a data set of aligned protein domain superfamilies of known three‐dimensional structure, we compared the location of interdomain interfaces on the tertiary folds between members of distantly related protein domain superfamilies. The data set analyzed is comprised of interdomain interfaces, with domains occurring within a polypeptide chain and those between two polypeptide chains. We observe that, in general, the interfaces between protein domains are formed entirely in different locations on the tertiary folds in such pairs. This variation in the location of interface happens in protein domains involved in a wide range of functions, such as enzymes, adapters, and domains that bind protein ligands, or cofactors. While basic biochemical functionality is preserved at the domain superfamily level, the effect of biochemical function on protein assemblies is different in these protein domains related by superfamily. The divergence between proteins, in most cases, is coupled with domain recruitment, with different modes of interaction with the recruited domain. This is in complete contrast to the observation that in closely related homologous protein domains, almost always the interaction interfaces are topologically equivalent. In a small subset of interacting domains within proteins related by remote homology, we observe that the relative positioning of domains with respect to one another is preserved. Based on the analysis of multidomain proteins of known or unknown structure, we suggest that variation in protein–protein interactions in members within a superfamily could serve as diverging points in otherwise parallel metabolic or signaling pathways. We discuss a few representative cases of diverging pathways involving domains in a superfamily. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Dirac equation with a Coulomb plus scalar potential in D + 1 dimensions
Authors: Dong Shi‐Hai , Sun Guo‐Hua , Lozada‐Cassou M. 
Published: November 2004

AbstractWe generalize the Dirac equation to D + 1‐dimensional spacetime. The exact solutions of the D‐dimensional radial equations with a Coulomb plus scalar potential taking the form 1/r are analytically presented by studying the Tricomi equations. The energies E(n, l, D) are exactly presented. The dependences of the energies E(n, l, D) on the dimension D are analyzed in some detail. The energies E(n, 0, D) first decrease and then increase when increasing dimension D, but the energies E(n, l, D) (l ≠ 0) increase when increasing dimension D. The energies E(n, 0, D) are symmetric with respect to D = 1 for D ∈ (0, 2). It is shown that the energies E(n, l, D) (l ≠ 0) are almost independent of the quantum number l for large D and are completely independent of it if the Coulomb potential is equal to the scalar one. The energies E(n, l, D) almost overlap for large D. The dependences of the energies E(n, l, v) and E(n, l, s) on the vector potential parameter v and scalar potential one s are also studied for D = 3. All are found to decrease when these parameters are increased. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical study of ANTO molecular systems: Causes of insensitivity of the energetic compound NTO
Authors: Liu Min‐Hsien , Chen Cheng , Hong Yaw‐Shun 
Published: November 2004

AbstractThe ANTO molecular system, which comprises the energetic compound 3‐nitro‐1,2,4‐triazole‐5‐one (NTO, with its two lowest‐energy conformers L1 and L2), ammonia (NH3), and water (H2O) molecules, is introduced for a theoretical survey of corresponding geometrical structure and localized bonding character. With the medium (or solvent) of H2O and NH3, three intermolecular hydrogen bonds formed in the NTO + NH3 + H2O system would lower the overall molecular energy and stabilize. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical study of two C30H20 isomers with a dodecahedrane cage and two pentaprismane cages sharing two pentagons
Authors: Liu Feng‐Ling , Zhao Jian‐Xia , Xie Ying , Dai Lian‐Hua 
Published: November 2004

AbstractStructures, energies, and vibrational frequencies have been calculated for two C30H20 isomers with a dodecahedrane cage and two pentaprismane cages at the B3LYP/6‐31G* level of theory. Thus, two C30H20 isomers have the form of coplanar tri‐cage molecules. The symmetry of one C30H20 isomer is of D5d and that of another is of C2V. The heat of formation for two C30H20 isomers have been estimated. Heats of formation of two C30H20 isomers as well as the vibrational analysis indicate that two C30H20 isomers enjoy sufficient stability to allow for its experimental preparation. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Longitudinal NLO properties of C2H2, HCCF, and C2F2: Electron correlation and vibration effects
Authors: Medveď Miroslav , Noga Jozef , Jacquemin Denis , Perpète Eric A. 
Published: November 2004

AbstractElectron correlation and vibration effects on longitudinal nonlinear optical properties of acetylene (C2H2), fluoroacetylene (HCCF), and difluoroacetylene (C2F2) have been studied using various quantum chemistry methods, including the second‐order perturbation theory (MP2); coupled cluster approach with singles, doubles (CCSD), and noniterative triples (CCSD(T)); and density functional methods (B3LYP and B98). Evaluation of the static and dynamic vibration (nuclear relaxation) contributions was based on the finite field relaxation method. Particular attention has been devoted to the assessment of the electron correlation effects on the nuclear relaxation contributions to the molecular properties. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical study of unimolecular rearrangements of vinylidenes to acetylenes
Authors: Kakkar Rita , Pathak Mallika , Chadha Preeti 
Published: November 2004

AbstractThe rearrangement of vinylidene to acetylene has been studied in detail by the density functional method, using Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Parr. The rearrangement of the anion, as well as that of fluoro‐substituted systems, has also been investigated, in order to determine the effect of fluorine substitution on the activation barrier to the 1,2‐hydrogen shift, as well as the relative migratory aptitudes of hydrogen and fluorine. Natural bond orbital analysis is invoked to gain insight into the mechanisms of the rearrangements. Basis size effects are also discussed, particularly in relation to anionic systems. The need to include diffuse functions in geometry optimizations of anionic systems is reinforced by the present calculations. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A theoretical investigation of the interaction between H, Li, Na, K, and fullerenes
Authors: Santos J. D. , Longo E. , Banja M. E. , Espinoza V. A. A. , Taft C. A. 
Published: November 2004

AbstractWe studied the interaction between H, Li, Na, and K with one and two C60 molecules using unrestricted Hartree–Fock (UHF) methods. We investigated the effects of distances between the doping atoms and the C60 clusters, total charges, interaction energies, stabilities, HOMO‐LUMO energy differences, charge distribution, and potential energy surfaces. The effect of each doping atom was analyzed and potential technological applications discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Pulse function for control of the coherent excitation in stimulated Raman spectroscopy
Authors: Malinovskaya S. A. 
Published: November 2004

AbstractA selective excitation of closely spaced Raman transitions using femtosecond pulse shaping is studied within a semiclassical approach. An analytical pulse function is proposed having duration T that selectively excites one of two transitions separated by a frequency interval less than 1/T. It is shown that, for intense fields, both the field amplitude and pulse frequency spectrum have to be carefully chosen to achieve the control of excitations. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Structural accelerated failure time models for the effects of observed exposures on repeated events in a clinical trial
Authors: Vandebosch An , Goetghebeur Els , Van Damme Lut 
Published: November 2004

AbstractStructural accelerated failure time models form a unique tool for the analysis of causal effects of observed exposures in randomized trials. When actual exposure levels are not completely controlled they may be selective, i.e. depend on unmeasured prognostic factors. Nevertheless, consistent randomization‐based estimators have been derived for the effect of such exposures on a right‐censored survival outcome. In this paper, we extend the methodology to allow for estimation of the structural effect of an experimental vaginal gel on repeated occurrences of genital lesions. The marginal distribution of each ordered event is modelled assuming a common treatment effect. Estimation is possible by inverting α‐level tests using a robust variance estimator to allow for correlated repeated events. We discuss the logical constraints imposed by this model choice as well as new challenges posed on recensoring. Copyright © 2004 John Wiley & Sons, Ltd.
Trematodes in a Cyathura carinata population from a temperate intertidal estuary: infection patterns and impact on host
Authors: Jensen K. Thomas , Ferreira Susana M. , Pardal Miguel A. 
Published: November 2004

A study was initiated to identify trematode patterns in Cyathura from two key sites in the Mondego Estuary: a Zostera-bed and a sand flat. The two subpopulations of Cyathura differ, as the annual recruitment success is much higher and more regular on the sandflat than on the Zostera-bed.Counting and sizing of trematode cysts inside the body of preserved Cyathura specimens enabled a description of trematode patterns in space and time. Further identification of trematodes was based on DNA studies of unpreserved cysts as well as on identification of parasites in co-occurring mud snails. Two trematode species dominated in Cyathura: Maritrema subdolum (cysts around 190 μm) and a hitherto unknown Levinseniella species (cysts around 340 μm), the latter being the most frequent one. Generally, the prevalence of both species peaked during winter months, when migratory water birds occur in the estuary. Cyathura from the Zostera bed harboured more infections per specimen than those from the sand flat. A much higher density of mud snails ≥52 mm (which can be host to microphallids) and a low abundance of Cyathura are thought to be the main reasons for this pattern. Field data did indicate a host size-dependent maximum number of cysts in Cyathura that could be a result of enhanced mortality at high cyst intensities. Furthermore, parasites were underrepresented among ovigerous Cyathura specimens, suggesting a negative impact on gametogenesis. As a consequence, microphallid trematodes may be a critical factor controlling recruitment strength in Cyathura, especially at the Zostera-site.
Physiological function and neuromuscular recruitment in elite South African distance runners
Authors: Noakes Timothy D , Harley Yolande XR , Bosch Andrew N , Marino Frank E , Gibson Alan St Clair , Lambert Michael I 
Published: November 2004

AbstractPhysiological studies of elite and sub-elite black South African runners show that these athletes are typically about 10–12 kg lighter than white athletes and that they are able to sustain higher exercise intensities for longer than white runners. Such superior performance is not a result of higher V O2max values and hence cannot be due to superior oxygen delivery to the active muscles during maximal exercise, as is predicted by the traditional cardiovascular/anaerobic/catastrophic models of exercise physiology. A marginally superior running economy is also unlikely to be a crucial determinant in explaining this apparent superiority. However, black athletes are able to sustain lower rectal and thigh, but higher mean skin, temperatures during exercise. Furthermore, when exercising in the heat, lighter black athletes are able to maintain higher running speeds than are larger white runners matched for running performance in cool environmental conditions. According to the contrasting theory that the body acts as a complex system during exercise, the superiority of black African athletes should be sought in an enhanced capacity to maintain homeostasis in all their inter-dependent biological systems despite running at higher relative exercise intensities and metabolic rates. In this case, any explanation for the success of East African runners will be found in the way in which their innate physiology, training, environment, expectations and genes influence the function of those parts of their subconscious (and conscious) brains that appear to regulate the protection of homeostasis during exercise as part of an integrative, complex biological system.