bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of radiologic imaging at the time of initial diagnosis of stage T1b‐T3b melanoma
Authors: Yancovitz Molly , Finelt Nika , Warycha Melanie A. , Christos Paul J. , Mazumdar Madhu , Shapiro Richard L. , Pavlick Anna C. , Osman Iman , Polsky David , Berman Russell S. 
Published: July 2007

AbstractBACKGROUND.In patients with T1b‐T3b cutaneous melanoma the utility of radiologic imaging at the time of diagnosis is unclear. Whether initial imaging led to a change in stage or treatment plan was investigated.METHODS.The melanoma database was searched for patients with T1b‐T3b primary lesions, clinically N0, and asymptomatic for metastatic disease. Radiologic studies conducted before wide local excision ± sentinel lymph node biopsy as well as all further imaging and investigations were analyzed. Outcome measures included upstaging, change in initial surgical management, true‐positive, false‐positive, true‐negative, and false‐negative rates of each imaging modality.RESULTS.In all, 344 preoperative imaging studies (chest x‐ray [CXR], computed tomography [CT], positron emission tomography [PET]/CT) were performed on 158 patients, resulting in 49 findings suspicious for metastatic melanoma and 134 findings suggestive of nonmelanoma pathology. Only 1 of 344 (0.3%) studies, a PET/CT, correlated with confirmed metastatic melanoma. The false‐positive rates were CXR 5 of 7 (71.4%), chest CT 21 of 24 (87.5%), abdomen/pelvis CT 10 of 11 (90.9%), head CT 2 of 2 (100.0%), PET/CT 3 of 5 (60.0%). No patient was upstaged or had a change in initial surgical management based on preoperative imaging. The cost of all initial imaging and imaging to follow‐up abnormal findings was estimated as $555,308 for the 158 patients studied.CONCLUSIONS.Imaging at the time of initial diagnosis of T1b‐T3b, clinically N0, M0 melanoma was of low yield with a high false‐positive rate, and did not lead to upstaging or change in initial surgical management. These findings suggest that imaging of asymptomatic patients at the time of diagnosis may not be warranted. Cancer 2007. © 2007 American Cancer Society.
Neural development of the zebrafish (Danio rerio) pectoral fin
Authors: Thorsen Dean H. , Hale Melina E. 
Published: July 2007

AbstractThe innervation and actuation of limbs have been major areas of research in motor control. Here we describe the innervation of the pectoral fins of the larval zebrafish (Danio rerio) and its ontogeny. Imaging and genetic tools available in this species provide opportunities to add new perspectives to the growing body of work on limbs. We used immunocytological and gross histological techniques with confocal microscopy to characterize the pattern of pectoral fin nerves. We retrogradely labeled fin neurons to describe the distributions of the pectoral fin motor pool in the spinal cord. At 5 days postfertilization, four nerves innervate the pectoral fins. We found that the rostral three nerves enter the fin from the dorsal side of the fin base and service the dorsal and middle fin regions. The fourth nerve enters the fin from the ventral fin base and innervates the ventral region. We found no mediolateral spatial segregation between adductor and abductor cell bodies in the spinal cord. During the larval stage pectoral fins have one adductor and one abductor muscle with an endoskeletal disc between them. As the skeleton and muscles expand and differentiate through postlarval development, there are major changes in fin innervation including extensive elaboration to the developing muscles and concentration of innervation to specific nerves and fin regions. The pattern of larval fin innervation recorded is associated with later muscle subdivision, suggesting that fin muscles may be functionally subdivided before they are morphologically subdivided. J. Comp. Neurol. 504:168–184, 2007. © 2007 Wiley‐Liss, Inc.
Why do Barlow points not coincide with the reduced Gauss quadrature points for higher‐order finite elements?
Authors: Zhang Xiaosong 
Published: July 2007

AbstractThis paper presents the reason why Barlow points do not coincide with the reduced Gauss quadrature points for higher‐order finite elements. Based on the numerical implementation for one‐dimensional bar by finite elements, it is found that the reason for noncoincidence of Barlow points and the reduced Gauss quadrature points for higher‐order elements is due to the mismatch of nodal displacements by FEM with the exact solution. Copyright © 2007 John Wiley & Sons, Ltd.
Prisoner's dilemma and clusters on small‐world networks
Authors: Thibert‐Plante Xavier , Parrott Lael 
Published: July 2007

AbstractThe structure of interaction plays an important role in the outcome of evolutionary games. This study investigates the evolution of stochastic strategies of the prisoner's dilemma played on structures ranging from lattices to small world networks. Strategies and payoffs are analyzed as a function of the network characteristics of the node they are playing on. Nodes with lattice‐like neighborhoods tend to perform better than the nodes modified during the rewiring process of the construction of the small‐world network. © 2007 Wiley Periodicals, Inc. Complexity 12:22–36, 2006
Electrostatic Probe Measurements in the Glow Discharge Plasma of a D. C. Magnetron Sputtering System
Authors: Petrov I. , Orlinov V. , Ivanov I. , Kourtev J. 
Published: July 2007

AbstractThe characteristics of the plasma surrounding the substrates in a planar magnetron sputtering system with a graphite target have been investigated by electrostatic probe measurements. The behaviour of the ion density ni and the electron temperature Te, determining the ion flux that can be extracted by the substrate, with the variation of the basic system parameters, has been studied.
Fluid Models for a Tokamak Scrape‐Off Plasma
Authors: Petravic M. , Kuo‐Petravic G. , Arzt T. 
Published: July 2007

AbstractA fluid model which includes ion drifts has been applied to the SOL of a tokamak with a poloidal divertor. Large parallel velocities and steep gradients in the pressure and electrostatic potential are found near the X‐point, in contrast with the solutions of the standard model.
Magnetogravitational Stability of Resistive Plasma through Porous Medium with Thermal Conduction and FLR Corrections
Authors: Vaghela D. S. , Chhajlani R. K. 
Published: July 2007

AbstractThe problem of stability of self gravitating magnetized plasma in porous medium is studied incorporating electrical resistivity, thermal conduction and FLR corrections. Normal mode analysis is applied to derive the dispersion relation. Wave propagation is discussed for parallel and perpendicular directions to the magnetic field. Applying Routh Hurwitz Criterion the stability of the medium is discussed and it is found that Jeans' criterion determines the stability of the medium. Magnetic field, porosity and resistivity of the medium have no effect on Jeans' Criterion in longitudinal direction. For perpendicular direction, in case of resistive medium Jeans' expression remains unaffected by magnetic field but for perfectly conducting medium magnetic field modifies the Jeans' expression to show the stabilizing effect. Thermal conducitivity affects the sonic mode by making the process isothermal instead of adiabatic. Porosity of the medium is effective only in case of perpendicular direction to magnetic field for perfectly conducting plasma as it reduces the stabilizing effect of magnetic field. For longitudinal wave propagation, though FLR corrections have no effect on sonic mode but it changes the growth rate for Alfvén mode. For transverse wave propagation FLR corrections and porosity affect the Jeans' expression in case of nonviscous medium but viscosity of the medium removes the effect of FLR and porosity on Jeans' condition.
Modelling of the Positive Column in an Argon‐Hexamethyl‐disiloxane dc Glow Discharge
Authors: Schmidt M. , Maass M. 
Published: July 2007

AbstractA model is presented of the positive column of a dc glow discharge in argon with small admixtures of hexamethyldisiloxane (HMDS). The axial electric field, the ion production rates for direct‐, stepwise‐, pair‐, and Penning ionization, the densities of metastable Ar atoms and of electrons, and the wall current of HMDS ions are calculated in dependence on HMDS admixture and discharge current density. For the calculations particle balance equations were used for a diffusion determined plasma in a mixture of two gaseous components. The reaction rates for the electron collision processes were determined applying the electron distribution function calculated for pure argon. Taking into account PENNING ionization of HMDS molecules by metastable argon atoms the decrease of electric field for increasing HMDS admixtures is according to the experimen‐tally measured values. Also ion wall currents and electron densities are compared with experimen‐tal values for thin film formation rate and results of probe measurements.
Analysis of the Near‐Anode Processes Characters in Argon Arc Discharges of High Pressure
Authors: Nazarenko I. P. , Panevin I. G. 
Published: July 2007

AbstractIn this paper the anode layer model including two zones is considered. It is suggested that in the collisionalless zone (the sheath) the potential drop is negative. For the collisional part of the anode layer the equation system is considered. This system takes into account the ionization non‐equilibrium in this layer. Here side by side with the electrical field the complementary diffusion mechanism of the current transfer is examined. This mechanism is stipulated by the existence of the electron gas pressure gradients in the anode layer. It is shown that the potential drop in the collisional part of the anode layer is also negative because of the action of the diffusion mechanism of the current transfer. In this way the full potential drop in the anode layer of the discharge burning in argon by atmospere pressure is turned out to be negative. The character of the change of the energy and impulse equations terms is discussed.
Theory of Weak Modified Electron Acoustic Double Layers and Solitary Waves in Presence of Negative Ions
Authors: Dey M. , Goswami K. S. , Bujarbarua S. 
Published: July 2007

AbstractWe have studied the analytic solutions for modified electron acoustic double layers and solitary waves in a four component plasma system viz. two electrons and two ions, one positive and the other negative. It has been shown that DL solution does not exist when the temperatures of the free and the trapped particles are considered to be same for all the free species. On the other hand, DL solutions are found to exist when the effects of the reflected electrons (hot) are considered. The velocity and thickness of the DL have been valculated.
Theory of Optogalvanic Signals Originating from Metastable States in Hollow Cathode Neon Discharges
Authors: Sofonea V. , Popescu I. I. 
Published: July 2007

AbstractA previous theoretical model is enlarged to elucidate some features of the optogalvanic signals originating from the metastable states in hollow cathode neon discharges. Numerical experiments were performed on the basis of this model to obtain the time evolution of the optogalvanic signals in pulsed and chopped cw experiments at 588.2 nm for different discharge currents and different laser intensities. The predictions of the numerical experiments were found to be in qualitative agreement with real experimental results.
Magnetic Electron Drift Vortex Modes in General Equilibria
Authors: Stenflo L. , Yu M. Y. , Shukla P. K. 
Published: July 2007

AbstractThe equation and dispersion relation describing the magnetic electron drift vortex mode in a generalized equilibrium are presented. The results are useful for investigating related surface wave problems as well as for identifying the various forms of the magnetic electron drift vortex mode.
Nonlinearly‐coupled Langmuir and Ion‐Acoustic Waves
Authors: Shivamoggi Bhimsen K. 
Published: July 2007

AbstractIn a plasma acted on by an intense laser field, one encounters the problem of nonlinearly‐coupled Langmuir and ion‐acoustic waves. We use a generalized perturbation theory to discuss the nature of coupled oscillatory waves in this system, and the possibility of formation of an ionsheath.
A Probe Method for Determination of time Evolution of Metastable Atoms Density in a Flowing Afterglow Plasma
Authors: Pavlík J. , Glosík J. , Šícha M. , Tichý M. , Potoček P. 
Published: July 2007

AbstractThe Langmuir Probe Measurement of the electron density and electron temperature has been made in the argon flowing afterglow plasma. Furthermore the metastable and charged particle densities evolution in the afterglow plasma are investigated by means of a numerical solution of the set of balance equations. From the fitting of the results of these calculations to the experimental data obtained from Langmuir probe measurements it is possible to determine the evolution of the metastable atoms density in the flowing afterglow plasma.
Harmonics Analysis of the Electron Component of rf Bulk Plasmas. I. Theoretical Base
Authors: Voigt H.‐D. , Wilhelm J. , Winkler B. 
Published: July 2007

Abstractrf discharges are increasingly used in low pressure plasma processing, i.e. for etching, film deposition and sputtering. The modelling of such discharges is a very complex task, especially dependent on discharge conditions, however of large importance for the insight into the main physical processes and thus for their control to improve the final results. One main important aspect is the determination of the electron velocity distribution function and of relevant rate and transport coefficients. The paper contributes to the treatment of this problem. In the first part a systematic Fourier expansion of the kinetic equation and of the consistent particle, energy and momentum balance equation is described. Then, a mathematical analysis of the resulting ordinary differential equation system for the coefficients of the Fourier expansion is performed. Based upon this we succeeded to develop a numerical approach to calculate the physical relevant solution of this system. By this approach in addition to the harmonics of the distribution function that of relevant macroscopic quantities, as transport coefficients and collision frequencies, can be determined. In the second part of this paper this method will be applied to investigate the bulk plasma of a rf discharge in molecular hydrogen.
Langmuir Probe Determination of Charged Particles Density in an rf Discharge
Authors: Šícha M. , Špatenka P. , Tichý M. 
Published: July 2007

AbstractThe article presents results of probe measurements of the electron and ion densities in an argon rf discharge. The electron density is determined from the electron probe current at the space potential which is estimated by extrapolation of the linear part of the probe electron current dependence to the plasma potential. The plasma potential is calculated from the floating potential. The positive ion density is determined from the probe ion saturated current according to collisional KOPICZYNSKI and ZAKREWSKI model [1]. The agreement between the electron and ion densities is better than in the work of HOPKINS and GRAHAM [2], where the collisionless Lafram‐boise theory is used under similar conditions.
Arc Discharge in a Channel with Transparent Walls at Intense Flow Rates of a Plasma Forming Gas
Authors: Pustogarov A. V. , Karabut A. B. , Kucherov Ya. R. 
Published: July 2007

AbstractThe arc discharge was studied in a transparent channel at an intense flow rate of nitrogen, hydrogen, air, carbon dioxide in the current range 100–1500 A. The internal diameter of the porous channel varied from 10 to 34 mm, the length ‐ from 50 to 150 mm, the air and nitrogen flow rates ‐ from 0.05 to 1.5 kg/s, hydrogen ‐ from 0.005 to 0.05 kg/s. The electric field strength in the arc channel reached a value of 300 V/cm for N2 and 500 V/cm for H2. The effect of plasma thermochemical non‐equilibrium was discovered.
Approximate Solution of the Saha Equation — Temperature as an Explicit Function of Particle Densities
Authors: Sato M. 
Published: July 2007

AbstractThe Saha equation for a plasma in thermodynamic equilibrium (TE) is approximately solved to give the temperature as an explicit function of population densities. It is shown that the derived expressions for the Saha temperature are valid approximations to the exact solution. An application of the approximate temperature to the calculation of TE plasma parameters is also described.
Hydrodynamic Theory of Low‐Pressure Multi‐Component Discharges with Neutral Gas Depletion
Authors: Shapiro D. A. , Valentini H.‐B. 
Published: July 2007

AbstractA hydrodynamic description of a low‐pressure discharge with singly and doubly‐charged positive ions in the high ionization regime is given. Modified hydrodynamic equations are used to include the neutral gas depletion by ionization processes under free‐flight conditions. Analytical formulas for the concentrations of the two species of ions at the discharge axis are derived.Numerical results for the radial drift velocities, the radial distributions of the densities and the neutral gas temperature are presented. The nature of the dip in the density profile of the singly‐charged ions and the decrease in their radial drift velocity near the axis with increasing degree of ionization are discussed.
Spectroscopic Detection of Oxygen in Nitrogeneous Gas Mixtures
Authors: Ross W. , Berger D. , Erbs H. , Gündel H. , Kornejew P. , Volkmann H. 
Published: July 2007

AbstractA pulsed high‐frequency discharge was used to excite a non‐LTE (local thermal equilibrium) plasma with a high specific power density sufficiently high to dissociate oxygen and gaseous oxides. If traces of hydrocarbons were present in the gas mixture, in the spectrum the Violet system of CN appeared with a long radiation decay time. The CN bands are excited preferentially by inelastic collisions with metastable nitrogen molecules (A3σ). These levels can be efficiently depopulated by competing impact with atomic oxygen. By measuring the radiation signal during the radiation decay a dynamic range of 6 was achieved for a variation of the oxygen content between 1 and 100 ppm.The measured radiation decay of the violet CN 0–0‐bands at 388 nm was simulated by a simple model of rate equations valid in the time region where diffusion processes may be neglected.
Investigation of Gas Degradation in CO2  N2 Pulse Discharges I. Long Term Behaviour of Pulsed Laser Discharges in CO2 — N2 Gas Mixtures
Authors: Rudolph R. , Bisin P. , Berger D. , Francke K.‐P. 
Published: July 2007

AbstractThe correlation between the plasma resistance and the laser output parameters has been investigated in pulsed CO2 — N2 discharges. The strong increase of the discharge resistance during gas degradation can be explained on the basis of strong attaching gas components. In degraded mixtures a supression of discharge instabilities together with the restoration of the laser pulse energy is possible by increasing the reduced electric field E/N temporarily.
Investigation of Gas Degradation in CO2–N2 Pulse Discharges II. Origin and Influence of Highly Attaching Species
Authors: Rudolph R. , Bisin P. , Berger D. 
Published: July 2007

AbstractThe mechanism of plasma resistance increase found in sealed CO2—N2 discharges has been analyzed. From the various species occuring in such discharges only oxides of nitrogen seem to be suitable candidates. Indeed the degradation process can be simulated by adding a certain amount of N2O. The failure in detection of these contaminants in naturally degraded mixtures suggests the involvement of complex molecular species depending strongly on the discharge conditions.
Kinetic Buneman Instability in a Homogeneous Hot Electron Plasma
Authors: Khalil S. H. M. , Mohamed B. F. 
Published: July 2007

AbstractThe development of Buneman kinetic instability in plasma with hot electrons and cold ions is investigated in the quasilinear approximation at current velocites close to the instability threshold values. It is shown that the contribution of electron's dielectric permeability in the dispersion equation is negligible and that quasilinear theory has in general stabilizing effect.
The Nonstationary Behaviour of the Electron Current Density in the Weakly Inonized Plasma at High Field Frequencies
Authors: Gundermann S. , Winkler R. 
Published: July 2007

AbstractBased upon former studies concerning the nonstationary electron kinetics in collision dominated, weakly ionized plasmas the phase delay between the ac electric field component and the resultant ac electron current density has been analysed, theoretically and experimentally, under the specific conditions of a microwave field superimposed to a dc discharge plasma column. The complex plasma conductivity and thus the phase delay has been calculated by solving an appropriate electron kinetic equation. The same quantities have been experimentally determined by using the microwave cavity which operates with different resonator modes. A comprehensive comparison between calculated and measured quantities for different neon discharge plasmas leads to a complete confirmation of the theoretical expectations.
Potential Surface Waves in a Warm Nonisothermal Plasma Bounded by Metal
Authors: Azarenkov N. A. , Ostrikov K. N. 
Published: July 2007

AbstractThe dispersion properties of potential surface waves (SW), propagating at a warm nonisothermal plasma‐metal boundary across the external magnetic field are studied in this paper. The existence of potential SW is shown to be possible in frequency ranges, where electromagnetic SW do not exist. The influence of transverse plasma density inhomogeneity on dispersion properties of the SW considered is studied as well.
Optical Emission Diagnostic of a Low Pressure Planar Microwave Discharge for Plasmachemical Deposition
Authors: Röpcke J. , Ohl A. 
Published: July 2007

AbstractLow pressure microwave plasmas are of growing interest for plasmachemical applications since they have special and in some cases unique advantages with respect to other plasma excitation methods. Subject of this paper are spatially resolved measurements of the optical emission of a special planar microwave plasma source utilized to investigate different plasmachemical processes. The optical emission spectroscopy (OES) is used as a tool to get information concerning the spatially distribution of reactive atom and molecule concentration by actinometry and concerning the neutral gas temperature by measurements of Doppler line broadening. The results refer to hydrocarbon containing hydrogen plasmas which gas pressures above 100 Pa. Surprisingly measurements confirm an earlier developed simplified two layer model consisting of a preferentially physically active plasma layer near the microwave window followed by a preferentially chemically active decaying region. They give evidence that this model is more adequate to the real physical situation as assumed until now.
The Application of Moment Equations to Scrape off Layer Plasmas
Authors: Radford G. J. 
Published: July 2007

AbstractA set of 21 moment fluid equations has been applied to two aspects relevant to scrape off layer plasma transport codes. The first of these is the provision of classical parallel transport coefficients, particularly for impurity plasma ions. Although more general results have been obtained, those only for a low impurity density common ion temperature plasma are presented. The results reflect the coupling between heat and particle fluxes and a coupling of the main ion fluxes into the impurity fluxes. The second application is in response to the problem of nonphysical values for classical viscosities and heat fluxes in regions with large gradients. The basic five moment description of the Braginskii equations has been extended to a full thirteen moment approximation. The new equations are given and some preliminary numerical results from a one dimensional code are discussed.