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71.
Preoperative radiotherapy for adenocarcinoma of the rectosigmoid 总被引:2,自引:0,他引:2
Ninety-seven patients with adenocarcinoma of the rectosigmoid have been treated with high dose (5000-6000 rad) preoperative irradiation from 1960 through 1972 at the University of Oregon Health Sciences Center. Fifty-seven were initially clinically resectable and 40 were initially inoperable. Forty of the 57 initially clinically resectable patients had "curative" resections and are at risk for more than 5 years. An increase in 5-year survival (from 38% to 53%) and an absence of pelvic recurrence have occurred in those patients receiving preoperative irradiation and "curative" resection. Four of the 40 initially inoperable patients are alive without tumor. Three of the four survivors had irradiation and surgery; one had irradiation only. An additional four patients had no evidence of tumor at death. Tumor was totally sterilized by irradiation and nine patients and reduced to microfocal extent in an additional three of the 97 patients. Incidence of complications was no greater than has been reported in a surgical series from the same institution. 相似文献
72.
Dario Natali Mario Caironi Marco Sampietro Andrew P. Meacham Steven J. Vickers Michael D. Ward 《Optical Materials》2006,28(12):1362-1365
We report on the electrochromic behavior of a dinuclear ruthenium complex, which provides high environmental stability together with an intense absorption maximum at 1237 nm in solution in its +3 oxidation state. To verify its optoelectronic properties, we used this complex as the photoactive material in a planar photodetector prototype for near-infrared light pulses, succeeding in the detection of a train of light pulses at a wavelength of 1280 nm. 相似文献
73.
Few studies have examined African American clients' subjective experiences in counseling from their perspective. This study used a constructivist paradigm, grounded theory methodology, and dimensional analysis to develop a model of clients' subjective experiences in counseling. Derived from clients' perspectives, the model suggests that the African American participants in this study engaged in an ongoing assessing process. Initially, they assessed client-therapist match, which was influenced by 3 factors: salience of Black identity, court involvement, and ideology similarity between client and therapist. These clients then assessed their safety in therapy and their counselor's effectiveness simultaneously. Clients in turn used information obtained from their assessing process to monitor and manage their degree of self-disclosing along a continuum. The model has important implications for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
74.
Static tests and ultrasonic measurements (2.25 MHz) have been carried out on a series of composite laminates of glass fibres
in a polypropylene matrix. A range of angle ply laminates were prepared for this study, with laminate angles θ of ±0, 10,
20, 30 and 40^∘. The high frequency measurements were made using the ultrasonic immersion technique, which allows the determination
of a complete set of the elastic constants of a material. The relationship between the ultrasonically determined elastic constants
of the angle ply laminates was found to be in excellent agreement with theoretical predictions, as previously validated for
carbon fibre/epoxy angle ply laminates.
A comparison between the ultrasonic and statically measured values was made for two of the angle ply laminates (θ = 0 and
20^∘). It was found that the static values were lower than those measured at ultrasonic frequency, particularly those constants
that were more matrix dominated (for example the transverse moduli of the laminates). Measurements on a pure polypropylene
sample at both testing frequencies confirmed that the change in matrix properties with frequency was the cause of this difference.
The change in properties with test frequency is likely to be much larger in this system than in other composite materials
because the glass transition temperature of polypropylene is close to ambient temperature. Dynamic mechanical tests (1 Hz)
were carried out on a sample of pure polypropylene to assess this effect. We also give an appropriate method of estimating
the dependence of glass transition temperature on frequency. The results for polypropylene are compared with those for other
commonly used polymer matrix materials: epoxy resin, nylon and polyetheretherketone (PEEK): DMTA measurements were also made
on these samples.
The effect of test frequency on matrix properties, for the glass/PP laminates, was further investigated by examining the relationship
of the Poisson's ratios with laminate angle using a mixture of ultrasonic experiments and theoretical predictions. Previously
we have shown that the degree of anisotropy between the reinforcing fibre and the matrix phase is paramount in determining
whether the material will show a negative Poisson's ratio at a critical laminate angle. The ultrasonic measurements carried
out in this study on the glass/PP laminates showed a minimum in one of the Poisson's ratio at a laminate angle of 32°, but
the value did not become negative. However, theoretical predictions showed that for a static frequency measurement (1 Hz),
where the matrix is softer and hence the anisotropy of each laminate ply is higher, the laminate will show a negative Poisson's
ratio with a minimum at a laminate angle of around 28°. 相似文献
75.
Numerical transform inversion can be useful to solve stochastic models arising in the performance evaluation of telecommunications and computer systems. We contribute to this technique in this paper by extending our recently developed variant of the Laguerre method for numerically inverting Laplace transforms to multidimensional Laplace transforms. An important application of multidimensional inversion is to calculate time-dependent performance measures of stochastic systems. Key features of our new algorithm are: (1) an efficient FFT-based extension of our previously developed variant of the Fourierseries method to calculate the coefficients of the multidimensional Laguerre generating function, and (2) systematic methods for scaling to accelerate convergence of infinite series, using Wynn's ε-algorithm and exploiting geometric decay rates of Laguerre coefficients. These features greatly speed up the algorithm while controlling errors. We illustrate the effectiveness of our algorithm through numerical examples. For many problems, hundreds of function evaluations can be computed in just a few seconds. 相似文献
76.
In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists and had to recall the list prior to that last presented list. In Experiment 3, either 1 or 2 lists were presented, and recall of TBR list was postcued. Recall proportion decreased with increased TBR list length. Moreover, the authors found extended recency effects when recall was replotted by when words were last rehearsed (Experiments 2 and 3) and an effect of intervening list length when rehearsal was reduced (Experiment 3). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
X. Luo K. Cheng Professor R. Ward 《The International Journal of Advanced Manufacturing Technology》2005,25(11-12):1089-1097
The paper presents a novel approach for modelling and simulation of the surface generation in the machining process. The approach, by integrating a dynamic cutting force model, regenerative vibration model, machining system response model and tool profile model, models the complex surface generation process. Matlab Simulink is used to interactively perform the simulation in a user-friendly, effective and efficient manner. The effects of machining variables and tooling characteristics on the surface generation are investigated through simulations. CNC turning trials have been carried out to evaluate and validate the approach and simulations presented. The proposed approach contributes to comprehensive and better understanding of the machining system, and is promising for industrial applications with particular reference to the optimisation of the machining process based on the product/component surface functionality requirements. 相似文献
78.
Shape deformation in continuous map generalization 总被引:2,自引:0,他引:2
Jeff Danciger Satyan L. Devadoss John Mugno Don Sheehy Rachel Ward 《GeoInformatica》2009,13(2):203-221
Given a collection of regions on a map, we seek a method of continuously altering the regions as the scale is varied. This
is formalized and brought to rigor as well-defined problems in homotopic deformation. We ask the regions to preserve topology,
area-ratios, and relative position as they change over time. A solution is presented using differential methods and computational
geometric techniques. Most notably, an application of this method is used to provide an algorithm to obtain cartograms.
Jeff Danciger Jeffrey received his undergraduate degree from the College of Creative Studies at UCSB in mathematics and physics. He is currently working on his Ph.D. in mathematics at Stanford University. His research interests include low dimensional topology and geometric analysis. Satyan L. Devadoss is an Associate Professor of Mathematics at Williams College. His research interests lie in the interplay between topology and geometry, notably in applications to theoretical physics (moduli spaces and string theory) and computer science (cartography and polytopes). John Mugno received his undergraduate degree from Williams College and is currently continuing his studies in mathematics at the University of Maryland. His areas of interest include combinatorics and topology. Don Sheehy received his undergraduate degree in Princeton University and is currently pursuing a PhD in Computer Science at Carnegie Mellon University. His research focuses on computational geometry algorithms for meshing. Rachel Ward received her undergraduate degree at the University of Texas at Austin. She is now a PhD student at Princeton University in the Program in Applied and Computational Mathematics. Her current work is in the area of compressed sensing, combining tools from computational harmonic analysis, probability, and optimization theory. 相似文献
Rachel WardEmail: |
Jeff Danciger Jeffrey received his undergraduate degree from the College of Creative Studies at UCSB in mathematics and physics. He is currently working on his Ph.D. in mathematics at Stanford University. His research interests include low dimensional topology and geometric analysis. Satyan L. Devadoss is an Associate Professor of Mathematics at Williams College. His research interests lie in the interplay between topology and geometry, notably in applications to theoretical physics (moduli spaces and string theory) and computer science (cartography and polytopes). John Mugno received his undergraduate degree from Williams College and is currently continuing his studies in mathematics at the University of Maryland. His areas of interest include combinatorics and topology. Don Sheehy received his undergraduate degree in Princeton University and is currently pursuing a PhD in Computer Science at Carnegie Mellon University. His research focuses on computational geometry algorithms for meshing. Rachel Ward received her undergraduate degree at the University of Texas at Austin. She is now a PhD student at Princeton University in the Program in Applied and Computational Mathematics. Her current work is in the area of compressed sensing, combining tools from computational harmonic analysis, probability, and optimization theory. 相似文献
79.
G E Tanner D G Angers D M Van Ess C A Ward 《Computer methods and programs in biomedicine》1986,23(3):237-242
Simulations based on physiologic modeling have been used for over twenty years to clarify the pharmacokinetics of inhaled anesthetics. We describe ANSIM, an anesthesia simulator for the IBM PC. ANSIM uses established modeling techniques to create a life-like anesthesia simulator. ANSIM is useful as an educational tool for demonstrating classic concepts of uptake and distribution of inhaled anesthetics. 相似文献
80.
Roberta J. Ward David T. Dexter Robert R. Crichton 《International journal of molecular sciences》2022,23(13)
Disturbance of the brain homeostasis, either directly via the formation of abnormal proteins or cerebral hypo-perfusion, or indirectly via peripheral inflammation, will activate microglia to synthesise a variety of pro-inflammatory agents which may lead to inflammation and cell death. The pro-inflammatory cytokines will induce changes in the iron proteins responsible for maintaining iron homeostasis, such that increased amounts of iron will be deposited in cells in the brain. The generation of reactive oxygen and nitrogen species, which is directly involved in the inflammatory process, can significantly affect iron metabolism via their interaction with iron-regulatory proteins (IRPs). This underlies the importance of ensuring that iron is maintained in a form that can be kept under control; hence, the elegant mechanisms which have become increasingly well understood for regulating iron homeostasis. Therapeutic approaches to minimise the toxicity of iron include N-acetyl cysteine, non-steroidal anti-inflammatory compounds and iron chelation. 相似文献