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161.
G Massimo Claar S Monaco C Del Veccho Blanco L Capurso M Fusillo B Annibale 《Canadian Metallurgical Quarterly》1998,12(5):463-468
Amyloid deposition in skeletal muscle is a well-recognized but rare occurrence. Sixteen such cases seen in a 17-year period (1979 to 1996) out of a total of 3,937 muscle biopsy specimens (0.004%) form this study group. Either Congo red or sulfated alcian blue stains were routinely performed in each biopsy to screen for amyloid. Patients in this study (eight men, eight women) ranged in age from 42 to 90 years (mean, 61 years) at initial presentation. The most common symptoms at presentation included weakness/fatigue (n = 10), autonomic symptoms (n = 8), and weight loss/decreased appetite (n = 7). Five patients had a concomitant malignancy (myeloma, n = 3; malignant carcinoid tumor, n = 1; melanoma, n = 1). Two patients had known hereditary forms of amyloidosis. Five patients had amyloid diagnosed on another organ biopsy (excluding peripheral nerve). Histologically, amyloid was deposited in the interstitium or perivascular region in 14 muscles and endomysial region in seven muscles. All cases were confirmed with Congo red staining (apple green birefringence) or by electron microscopic identification of fibrillary amyloid material. Scattered angular atrophic esterase-positive muscle myofibers indicative of acute denervation atrophy were seen in 14 muscles. Eight muscles showed small group atrophy, and seven showed myofiber type grouping. Scattered regenerating muscle fibers were seen in nine cases, degenerating myofibers in six, and foci of chronic endomysial and perivascular inflammation in two. Four muscles showed type II muscle fiber atrophy. A concomitant sural nerve biopsy specimen was evaluated in seven patients; all seven contained amyloid, confirmed either by Congo red staining or electron microscopic examination. In two nerves, there was a mild loss of myelinated axons; four had a moderate loss, and one, severe loss. Six of seven nerves showed predominantly axonopathic changes. In conclusion, (1) the prevalence rate of amyloid myopathy in muscle biopsy specimens was low (in this series, 0.004%); (2) only a minority of patients had multiple myeloma, and most presented with muscle weakness/fatigue or autonomic symptoms; (3) most of the muscles showed neurogenic features histologically; (4) all concomitant sural nerve biopsy specimens contained amyloid, and most showed a predominance of axonopathic changes. 相似文献
162.
Often hard real-time systems require results that are produced on time despite the occurrence of processor failures. This paper considers a distributed system where tasks are periodic and each task occurs in multiple copies which are periodically synchronized in order to handle failures. The problem of preemptively scheduling a set of such tasks is discussed where every occurrence of a task has to be completely executed before the next occurrence of the same task. First, a static scheduling algorithm is proposed which uses periodic checkpoints to tolerate processor failures. Then, the performance of the algorithm is substancially improved employing a mixed strategy which constructs a schedule where high frequency tasks are duplicated, and low frequency tasks are periodically checkpointed. The performance of the solution proposed is evaluated in terms of the minimum achievable processor utilization due to the useful computation of the tasks. Moreover, analytical and simulation studies are used to reveal interesting trade-offs associated with the scheduling algorithm. In particular, if high frequency tasks are less than 70 percent of the total number of tasks then the mixed strategy yields a higher processor utilization than the task duplication scheme. 相似文献
163.
The article presents the inverse dynamics model of a novel translating parallel machine and proposes the structure of a force controller for the execution of tasks characterised by interaction with the environment. The task space model of machine’s dynamics is obtained in an efficient and compact form by means of the principle of virtual work. A virtual prototyping environment has been set up to test by computer simulation the potential of such kinematic architecture: the resulting dynamics is rather poor, mainly due to the high moving masses, but it is shown that hybrid position/force control schemes should be able to provide good performances, including the case of rather difficult operations, such as the peg-in-hole assembly. 相似文献
164.
Simone Orcioni Giorgio Biagetti Massimo Conti 《Analog Integrated Circuits and Signal Processing》2004,38(2-3):215-231
A mixed analog-digital fuzzy logic inference processor chip, designed in a 0.35-μm CMOS technology, is presented. The analog fuzzy engine is based on a novel current-mode CMOS circuit used for the implementation of fuzzy partition membership functions. The architecture consists of a 3 inputs—1 output analog fuzzy engine, internal digital registers to store the parameters of the fuzzy controller, and a digital subsystem that allows the programmability of the fuzzy controller via an I 2 C interface. The architecture, circuits, and some Cadence Spectre simulations are presented. 相似文献
165.
Massimo La Deda Mauro Ghedini Iolinda Aiello Irene De Franco 《Inorganic chemistry communications》2004,7(12):1273-1276
This communication reports the synthesis of polymetallic species formed by a zinc-tetraphenolporphyrinate core (ZnTPP(OH)4, 1) and peripheral gallium-quinaldinate fragments. The photophysical analysis of 1 and of the model compound , R, shows an appreciable overlap between the absorption spectra of 1 and the emission spectra of R, suggesting the presence of a donor–acceptor energy-transfer process. Contrarily, the obtained results indicated that energy transfer does not occur, hence these polymetallic complexes work as double emitting species, for which the colour of luminescence depends on the excitation energy. 相似文献
166.
A set of quantitative data about signal processing effects on the evaluation of amplitude, duration, and peak-velocity of single saccadic eye movements, as well as on the evaluation of the coefficients of amplitude-peak velocity and amplitude-duration characteristics of a family of saccades, is given. The following aspects of signal processing are theoretically discussed, experimentally supported, and summarized by normative graphs: 1) the analog low-pass filtering applied to the recorded eye movement; 2) its sampling and digitization; 3) the low-pass filtering applied to the digitized signal; 4) the algorithm used to compute the eye velocity; 5) the criteria adopted to determine the beginning and the ending points of the saccades; and 6) the laws used to fit the saccadic characteristics. According to the theoretical and experimental results obtained, some general operating rules and optimal setups for each of the most common experimental situations are proposed, with the aim of standardizing saccade analysis for both researchers and clinicians. 相似文献
167.
Massimo Corcione 《International Journal of Heat and Mass Transfer》2005,48(17):3660-3673
Steady laminar free convection from flat vertical arrays of equally-spaced, horizontal isothermal cylinders set in free air, is studied numerically. A specifically developed computer-code based on the SIMPLE-C algorithm is used for the solution of the mass, momentum and energy transfer governing equations. Simulations are performed for arrays of 2-6 circular cylinders, for center-to-center separation distances from 2 up to more than 50 cylinder-diameters, and for values of the Rayleigh number based on the cylinder-diameter in the range between 5 × 102 and 5 × 105. It is found that the heat transfer rate at the bottom cylinder remains the same as a single cylinder. In contrast, the downstream cylinders may exhibit either enhanced or reduced Nusselt numbers depending on their location in the array and on the geometry of the array. Heat transfer dimensionless correlating equations are proposed both for any individual cylinder in the array and for the whole tube-array. New correlation-equations for the calculation of the heat transfer rate from a single cylinder to the surrounding air are also proposed and compared to those available in the open literature. 相似文献
168.
Lead and the Pb-Bi eutectic (Pb 55.9 at.%) have been modeled by a n-body potential derived from a second moment approximation of a tight binding Hamiltonian. The thermal behavior of the two systems in the liquid phase has been reproduced and relevant structural parameters have been evaluated and compared with experimental data. The diffusion coefficients and the activation energy for diffusion have been also evaluated. 相似文献
169.
Pietro Benetti Massimo Genoni Alessandra Tomaselli 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1988,270(2-3):411-415
The influence of photon peak arrival in the laser-optical fibers timing system of a large array of plastic scintillators has been studied for different types of photomultipliers. The obtained results, helpful in properly designing the system are presented and discussed. 相似文献
170.