bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved energetic recovery of skeletal muscle in response to ischemia and reperfusion injury followed by in vivo 31P‐magnetic resonance spectroscopy
Authors: Lundberg Jonas , Lindgård Ann , Elander Anna , Soussi Bassam 
Published: September 2002

AbstractIt is of great clinical interest to improve postischemic tissue recovery during microsurgical transfers. The effect of singlet oxygen energy (SOE) as photon illumination at 634 nm on rat skeletal muscle during ischemia and postischemic reperfusion was investigated noninvasively and continuously by in vivo 31P‐magnetic resonance spectroscopy (31P‐MRS). A model of pedicled rat rectus femoris muscle was used, where phosphorous metabolites were followed before onset of ischemia (control), after 4 h of ischemia, and after 1 h of reperfusion. Two groups were studied: one control group (n = 10), and one SOE‐treated group (n = 10). Blood perfusion was measured by laser Doppler flowmetry (LDF) during the study. After 4 h of ischemia, ATP levels were 72% and 51% of normal control values in the illuminated group and the control group, respectively (P < 0.05). After 1 h of postischemic reperfusion, phosphocreatine (PCr) recovered to 79% and adenosine triphosphate (ATP) to 71% in the illuminated group, whereas in the control group, the recovery was 57% and 51%, respectively (P < 0.05). It is concluded that singlet oxygen energy has a beneficial effect on the energy state of skeletal muscle during ischemia and postischemic reperfusion. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:158–164 2002
Oscillatory asymptotic expansion for semilinear wave equation
Authors: Pomponio Stefania Di 
Published: September 2002

AbstractWe study oscillatory properties of the solution to semilinear wave equation, assuming oscillatory terms in initial data have sufficiently small amplitude. The main result gives an a priori estimate of the remainder in the approximation by means of the method of geometric optics. The method of establishing this estimate is based on a combination between energy type estimates for transport equation and Sobolev embedding. Copyright © 2001 John Wiley & Sons, Ltd.
Genetic‐algorithm and finite‐element approach to the synthesis of dispersion‐flattened fiber
Authors: Correia Davi , Rodríguez‐Esquerre Vitaly F. , Hernández‐Figueroa Hugo E. 
Published: September 2002

AbstractA novel numerical approach for the efficient synthesis of dispersion‐flattened fibers is presented. This approach is based on the combination of genetic algorithms and finite elements. Severe constraints, such as a given maximum monochromatic dispersion level and maximum flatness over a desired band, are easily attained. To show the validity and usefulness of our approach, three different profiles are optimized, and their results are compared with published ones. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 245–248, 2001.
Broadband aperture‐coupled T‐shaped microstrip‐fed triangular patch antenna
Authors: Jang Yong‐Woong 
Published: September 2002

AbstractIn this letter, we propose a new structure of an aperture coupled T‐shaped microstrip‐fed triangular patch antenna, which has similar radiation pattern properties, with the advantage of being physically smaller than the aperture‐coupled rectangular patch antenna or microstrip slot antenna, and a bandwidth that is greater than the conventional triangle microstrip antenna. The measured bandwidth was 44.5% (VSWR≤2.0). Experimental results for the radiation pattern and the gain are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 262–264, 2001.
A low‐profile circularly polarized curl antenna over an electromagnetic bandgap (EBG) surface
Authors: Yang Fan , Rahmat‐Samii Yahya 
Published: September 2002

AbstractAn electromagnetic bandgap (EBG) surface is utilized as a ground plane for a curl antenna to achieve a low‐profile design as well as a circularly polarized pattern. The antenna height is greatly reduced compared to a normal curl antenna over a PEC ground plane. The frequency bandgap and ground plane size are discussed. Experimental results demonstrate the applicability of this concept. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 264–267, 2001.
A procedure to design stacked microstrip patch antennas based on a simple network model
Authors: Anguera J. , Puente C. , Borja C. 
Published: September 2002

AbstractA stacked patch configuration has been demonstrated experimentally as a feasible solution to enhance the bandwidth of a microstrip antenna, but little information on the design procedure is available. A design scheme based on a simple network model is presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 149–151, 2001.
A convenient and general approach for analyzing NRD‐guide leaky‐wave antennas
Authors: Sheng X. Q. , Yung K. N. 
Published: September 2002

AbstractIn this letter, a convenient and general approach is presented for analyzing nonradiative dielectric (NRD)‐guide leaky‐wave antennas using the finite‐element method (FEM) and perfectly matched layers (PMLs). A typical NRD‐guide leaky‐wave antenna is calculated to confirm the validity of the proposed approach. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 173–175, 2001.
Analysis of random grating period and amplitude errors in ultra‐thin long‐period grating
Authors: Chung Kun‐Wook , Yin Shizhuo 
Published: September 2002

AbstractThe effects of random fabrication errors on an ultra‐thin long‐period grating are numerically investigated. The influences of the random grating period and random amplitude nodes on an optical bandpass filter based on an ultra‐thin long‐period grating are introduced. It is found that the random period errors present severe degradation of the spectral performance of the ultra‐thin long‐period grating. The coupling intensity of the ultra‐thin long‐period grating decays exponentially with even small grating period noises. Our simulation results may help manufacturers to analyze the quality of fabricated long‐period gratings and to point out future improvement directions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 178–181, 2001.
Patch antenna with switchable slot (PASS): Dual‐frequency operation
Authors: Yang Fan , Rahmat‐Samii Yahya 
Published: September 2002

AbstractA novel kind of microstrip antenna, a patch antenna with a switchable slot (PASS), is proposed in this paper. A slot is incorporated into the patch, and a p‐i‐n diode is utilized to switch the slot on or off. This antenna can work at dual frequencies with a small and flexible frequency ratio and the same polarization. Experimental results validate this concept. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 165–168, 2001.
E‐plane waveguide filters with partially filled dielectrics for wide bandwidth
Authors: Liu Falin , Xu Shanjia 
Published: September 2002

AbstractA partially dielectric‐filled waveguide bifurcation structure is proposed to realize wideband bandpass filters. By using modal expansion and matching the tangential fields at the discontinuity, a variational expression for the input admittance is obtained. The Ritz method is used to form a group of linear equations from which the actual admittance can be obtained; then the equivalent‐circuit parameters of the discontinuity are achieved. It is confirmed that the structure is capable of realizing wideband filters. A numerical analysis of a filter example is conducted to justify the validity. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 175–177, 2001.
Leaky‐wave radiation from a grounded dielectric waveguide with finite periodic grooves on a conducting plane
Authors: Lee Cheol Hoon , Cho Young Ki 
Published: September 2002

AbstractThe leaky‐wave radiation problem from a grounded dielectric waveguide with finite conducting periodic grooves of an arbitrary profile is considered. To check the validity of the results for the finite periodic case, an analysis method for the infinite periodic case is also considered for comparison. The analysis method for the finite periodic case is based on a combined FEM (finite‐element method)/MoM (method of moments) procedure, whereas a full MoM procedure is used for the infinite periodic case. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 180–185, 2001.
A systematic method to design single‐patch broadband microstrip patch antennas
Authors: Anguera Jaume , Puente Carles , Borja Carmen , Font Gisela , Soler Jordi 
Published: September 2002

AbstractA simple electrical network for a single‐layer microstrip patch antenna (SLMPA) and the feeding structure (coaxial probe and compensating capacitor) is proposed to predict the input impedance. The mathematical analysis allows us to design an optimum feed that enhances the impedance bandwidth (BW). © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 185–188, 2001.
An efficient solution of the generalized eigenvalue problems for planar transmission lines
Authors: Prakash V. V. S. , Kuzuoglu Mustafa , Mittra Raj 
Published: September 2002

AbstractThis paper presents an efficient solution for solving the generalized eigenvalue equation arising in the finite‐element (FE) formulation of propagation characterization of planar transmission‐line structures. A two‐dimensional (2‐D) finite‐element method (FEM) is used for analyzing the uniform planar transmission lines. The Arnoldi algorithm is used in conjunction with the multifrontal decomposition of the system matrix for solving the eigensystem. Convergence is typically obtained within a few iterations of the Arnoldi process, and the formulation has proven to be robust, even when dealing with a significantly large number of unknowns. Numerical results are presented for the case of a uniform microstrip line, which clearly show the computational savings resulting from the use of the present approach. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 194–197, 2001.
Efficacy of ifosfamide and doxorubicin given as a phase II “window” in children with newly diagnosed metastatic rhabdomyosarcoma: A report from the Intergroup Rhabdomyosarcoma Study Group*
Authors: Sandler E. , Lyden E. , Ruymann F. , Maurer H. , Wharam M. , Parham D. , Link M. , Crist W. 
Published: September 2002

AbstractBackgroundThe cure rate for children/adolescents with localized rhabdomyosarcoma (RMS) has tripled over the past 25 years, but patients with metastatic disease at presentation have not benefited similarly, and urgently need new therapy. We evaluated a new drug pair, ifosfamide + doxorubicin, for such patients.ProcedureWe estimated the complete and partial response rates (i.e., CR and PR) of 152 previously untreated children/adolescents with metastatic RMS entered on the IRS‐IV pilot from July 1988 to October 1991 who received an “up‐front window” of ifosfamide (1.8 gm/m2/day for 5 days) and doxorubicin (30 mg/m2/day for 2 days) given every 3 weeks for 12 weeks. This was followed by combination chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC), given every 3 weeks for an additional 36 weeks.ResultsOf 115 patients evaluable for early response at 12 weeks, 28 (20%) had CR and 66 (43%) had PR. The ultimate CR rate was 52%. Overall, about one‐third of patients survived. Prognostic factor analysis revealed that patients < 10 years old (P < 0.001), those with embryonal tumors (P = 0.002), or a GU primary site (P = 0.010), and those who lacked nodal disease (P = 0.041), and those who lacked bone or bone marrow metastasis (P < 0.001) fared better than did others.ConclusionsThe 63% CR + PR rate achieved at 12 weeks and overall 5‐year FFS seen with this drug pair is similar to that achieved with previously evaluated drug combinations. We conclude that ifosfamide/doxorubicin is highly active in advanced RMS, and should be considered for inclusion in frontline therapy for children with intermediate or high‐risk RMS. Med Pediatr Oncol 2001;37:442–448. © 2001 Wiley‐Liss, Inc.
Improved accuracy of human cerebral blood perfusion measurements using arterial spin labeling: Accounting for capillary water permeability
Authors: Parkes Laura M. , Tofts Paul S. 
Published: September 2002

AbstractA two‐compartment exchange model for perfusion quantification using arterial spin labeling (ASL) is presented, which corrects for the assumption that the capillary wall has infinite permeability to water. The model incorporates an extravascular and a blood compartment with the permeability surface area product (PS) of the capillary wall characterizing the passage of water between the compartments. The new model predicts that labeled spins spend longer in the blood compartment before exchange. This makes an accurate blood T1 measurement crucial for perfusion quantification; conversely, the tissue T1 measurement is less important and may be unecessary for pulsed ASL experiments. The model gives up to 62% reduction in perfusion estimate for human imaging at 1.5T compared to the single compartment model. For typical human perfusion rates at 1.5T it can be assumed that the venous outflow signal is negligible. This simplifies the solution, introducing only one more parameter than the single compartment model, PS/vbw, where vbw is the fractional blood water volume per unit volume of tissue. The simplified model produces an improved fit to continuous ASL data collected at varying delay time. The fitting yields reasonable values for perfusion and PS/vbw. Magn Reson Med 48:27–41, 2002. © 2002 Wiley‐Liss, Inc.
Changes in axonal morphology in experimental autoimmune neuritis as studied by high b‐value q‐space 1H and 2H DQF diffusion magnetic resonance spectroscopy
Authors: Assaf Yaniv , Kafri Michal , Shinar Hadassah , Chapman Joab , Korczyn Amos D. , Navon Gil , Cohen Yoram 
Published: September 2002

AbstractExperimental autoimmune neuritis (EAN) has been studied in rat sciatic nerves by a combination of high b‐value 1H and 2H double quantum filtered (DQF) diffusion MRS. The signal decays of water in the 1H and 2H DQF diffusion MRS were found to be not monoexponential and were analyzed using the q‐space approach. The q‐space analysis of the 1H diffusion data detected two diffusing components, one having broad and the other having narrow displacement profiles. These components were shown to be very sensitive to the progression of EAN disease. The q‐space parameters were found to be abnormal at day 9 postimmunization before the appearance of clinical signs. The assignment of the component with the narrow displacement profile to axonal water has been corroborated by the 2H DQF diffusion MRS results. The displacement and the relative population of this slow and restricted diffusing component followed the processes of demyelination, axonal loss, and remyelination that occur in EAN. The displacements extracted from the slow‐diffusing component with the narrow displacement correlated well with the average size of the axons as deduced from electron microscopy (EM). The component with the broad displacement showed significant changes which were attributed to the formation of endoneurial edema. This observation was also corroborated by the 2H DQF diffusion MRS experiments. It seems, therefore, that q‐space analysis of high b‐values diffusion MRS is a promising new approach for early detection and better characterization of the different pathologies associated with EAN. This study demonstrates the utility of high‐b‐value q‐space diffusion MRS for studying white matter‐associated disorders in general. Magn Reson Med 48:71–81, 2002. © 2002 Wiley‐Liss, Inc.
Coupling and decoupling theory and its application to the MRI phased array
Authors: Lee Ray F. , Giaquinto Randy O. , Hardy Christopher J. 
Published: September 2002

AbstractIn classical MRI phased‐array design, optimal coil overlapping is used to minimize coupling between nearest‐neighbor coils, and low input impedance preamplifiers are used to isolate the relatively weak coupling between non‐nearest neighbors. However, to make the complex sensitivities of phased‐array coils sufficiently distinct in parallel spatially‐encoded MRI, it is desirable to have no overlapping between coils. Also, if phased arrays are used as transmit coils in MRI, one can no longer rely on the low input impedance of the preamplifiers for decoupling. Here a coupling and decoupling theory is introduced to provide a better understanding of the relations between coupled and uncoupled signals in the MRI phased array, and to offer a new method for decoupling phased‐array coils without overlapping the nearest coil pairs. The new decoupling method is based on the assumption that any n‐element phased array can be decoupled by a 2n‐port interface system between phased array and preamplifiers. The detailed analysis and the experimental results show that a four‐port interface can be used to decouple a two‐element phased array. Furthermore, the four‐port interfaces can serve as building blocks to construct a 2n‐port decoupling interface. This new method allows one to place the coil elements anywhere that could optimize parallel spatial encoding without concern for coupling between the coils. The method can also be used for phased‐array transmit coils. Magn Reson Med 48:203–213, 2002. © 2002 Wiley‐Liss, Inc.
Cardiac diffusion MRI without motion effects
Authors: Dou Jiangang , Reese Timothy G. , Tseng Wen‐Yih I. , Wedeen Van J. 
Published: September 2002

AbstractWe present a method for diffusion tensor MRI in the beating heart that is insensitive to cardiac motion and strain. Using a stimulated echo pulse sequence with two electrocardiogram (ECG) triggers, diffusion‐encoding bipolar gradient pulses are applied at identical phases in consecutive cardiac cycles. In this experiment, diffusion is encoded at a single phase in the cardiac cycle of less than 30 ms in duration. This encoding produces no phase shifts for periodic motion and is independent of intervening strains. Studies in a gel phantom with cyclic deformation confirm that by using this sequence we can map the diffusion tensor free of effects of cyclic motion. In normal human subjects, myocardial diffusion eigenvalues measured with the present method showed no significant change between acquisitions encoded at maximum contractile velocity (peak) vs. at myocardial standstill (end‐systole), demonstrating motion independence of in vivo diffusion measurements. Diffusion tensor images acquired with the present method agree with registered data acquired with a previous cardiac diffusion MRI method that was shown to be valid in the normal heart, strongly supporting the validity of MRI diffusion measurement in the beating heart. Myocardial sheet and fiber dynamics measured during systole showed that normal human myocardial sheet orientations tilt toward the radial during systole, and fiber orientations tilt toward the longitudinal, in qualitative agreement with previous invasive studies in canines. These results demonstrate the technique's ability to measure myocardial diffusion accurately at any point in the cardiac cycle free of measurable motion effect, as if the heart were frozen at the point of acquisition. Magn Reson Med 48:105–114, 2002. © 2002 Wiley‐Liss, Inc.
Imaging of intracellular sodium with shift reagent aided 23Na CSI in isolated rat hearts
Authors: Weidensteiner Claudia , Horn Michael , Fekete Elsbeth , Neubauer Stefan , von Kienlin Markus 
Published: September 2002

Abstract23Na chemical shift imaging (CSI) in conjunction with shift reagents was used to obtain images of intracellular (Nai) and extracellular sodium (Nae) in isolated rat hearts. It was demonstrated that the increase of Nai concentration in ischemic myocardium can be detected with this technique. 3D acquisition‐weighted 23Na CSI datasets with a nominal spatial resolution of 1.7 × 1.7 × 2.9 mm were acquired in 30 min in normoxic hearts and in globally or locally ischemic hearts. The shift reagent Tm(DOTP)5− was used to discriminate Nai and Nae signals. Nai maps could be generated in ischemic hearts, but not in normoxic hearts as the signal‐to‐noise ratio is too low. The Nai signal increased by more than 100% and the Nae signal decreased by more than 50% in myocardium of globally ischemic hearts (n = 3) compared to normoxic hearts (n = 3). In hearts with an acute occlusion of the left anterior descending coronary artery (n = 3), there was a local Nai signal increase in the anterior wall in the range of 60–110% compared to remote, normoxic tissue. Magn Reson Med 48:89–96, 2002. © 2002 Wiley‐Liss, Inc.
Extending the MAD portfolio optimization model to incorporate downside risk aversion
Authors: Michalowski Wojtek , Ogryczak Włodzimierz 
Published: September 2002

AbstractA mathematical model of portfolio optimization is usually represented as a bicriteria optimization problem where a reasonable tradeoff between expected rate of return and risk is sought. In a classical Markowitz model, the risk is measured by a variance, thus resulting in a quadratic programming model. As an alternative, the MAD model was developed by Konno and Yamazaki, where risk is measured by (mean) absolute deviation instead of a variance. The MAD model is computationally attractive, since it is easily transformed into a linear programming problem. An extension to the MAD model proposed in this paper allows us to measure risk using downside deviations, with the ability to penalize larger downside deviations. Hence, it provides for better modeling of risk averse preferences. The resulting m‐MAD model generates efficient solutions with respect to second degree stochastic dominance, while at the same time preserving the simplicity and linearity of the original MAD model. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 185–200, 2001
Optimal control of an M/G/1 queue with impatient priority customers
Authors: Lillo R.E. 
Published: September 2002

AbstractAn optimal operating policy is characterized for the infinite‐horizon average‐cost case of a single server queueing control problem. The server may be turned on at arrival epochs or off at departure epochs. Two classes of customers, each of them arriving according to an independent Poisson processes, are considered. An arriving 1‐customer enters the system if the server is turned on upon his arrival, or if the server is on and idle. In the former case, the 1‐customer is selected for service ahead of those customers waiting in the system; otherwise he leaves the system immediately. 2‐Customers remain in the system until they complete their service requirements. Under a linear cost structure, this paper shows that a stationary optimal policy exists such that either (1) leaves the server on at all times, or (2) turns the server off when the system is empty. In the latter case, we show that the stationary optimal policy is a threshold strategy, this feature being commonplace in most of priority queueing systems and inventory models. However, the optimal policy in our model is determined by two thresholds instead of one. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 201–209, 2001
Integrated networks that overflow speech and data between component networks
Authors: Lincke‐Salecker Susan , Hood Cynthia S. 
Published: September 2002

AbstractAs cellular networks diversify by expanding the number of services, cell sizes, and generations of technologies supported, it becomes possible to overflow dual‐mode terminals using vertical handovers to other cellular networks or ‘component networks’. This study varies call placement algorithms, by defining, modeling, and evaluating Overflow and Return policies. Copyright © 2002 John Wiley & Sons, Ltd.