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Radiological gout manifestations are detectable in the early stage, but also especially in the chronic stage of gout. Whereas in the early stage only soft tissue mutations (bursitis inflammation) and light calcium deposits are usually discernible, chronic gout leads to asymmetrical, diverse forms of osseous destruction, favouring smaller joints, but also affecting larger ones, which are caused by the intra-articular and extra-articular deposit of tophus material, corresponding to the progression and degree of severity of the illness. Radiologically-detectable changes in other organs, such as the kidneys, will be addressed. The high number of, and to some extent very characteristic, osseous mutations are compared with those mutations which are very similar to the diagnoses of other syndromes affecting the joints. Specifically, problems in differentiating diagnosis of rheumatoid arthritis, arthritis psoriatica, chondrocalcinosis, and other diseases of the joints will receive special mention. Reference is also made to the extreme diagnostic difficulties resulting from the rare but nevertheless conceivable influence of gout on the spine or sacroiliac joints. The method of magnetic resonance imaging for gout shows a characteristic signal behaviour of the tophus material. It has been determined that, through magnetic resonance tomography, interosseous tophi can be detected earlier and in a more widespread manner than with the aid of native X-ray images, such that an increase in the use of this method is to be expected. 相似文献
54.
Cruselles Ernesto J. Soriano Miguel Melús José Luis 《Wireless Personal Communications》1998,7(1):69-88
The prime characteristic of spread spectrum modulated signals is that their bandwidth is greater than the information rate. In this way a redundancy is introduced that allows the severe levels of inteference inherent in the transmission of digital information over radio and satellite links to be overcome. Current spread spectrum applications are primarily in military communications; nevertheless, there is growing interest in this technique for third generation mobile radio networks (UMTS, FPLTS, etc.) with open discussion regarding the practicality of using a multiple access system based on spread spectrum techniques (CDMA). However, in order to support as many users in the same bandwidth as other multiple access techniques such as TDMA or FDMA, it is important how to generate large families of sequences that present low cross-correlation. The aim of this paper is to describe a spreading codes generator that can produce a large number of PN sequences with good properties of auto- and cross-correlation. Moreover, the codes generated shows high unpredictability and good statistical behaviour. This also allows the implementation of some features that are common on military networks such as message privacy (increasingly important in commercial networks) without additional cost. The structure presented shows itself to be advantageous for high speed generation of codes at a low cost, low power consumption (allowing longer life for batteries), small size and simplicity of implementation, essential ingredients for commercial equipment. Another attractive feature is its structural parallelism, useful in VLSI implementations. All of these features render it potentially suitable for the implementation of channel bandwidth sharing systems in future wireless personal communications networks. 相似文献
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Rui A. S. Lapa José L. F. C. Lima 《Journal of Automated Methods and Management in Chemistry》1991,13(3):119-122
The construction of a microcomputer-controlled electrode switch for
use in potentiometric determinations is described. This can be coupled to most of the analytical equipment usually found in laboratories, to enable a setting up of automatic systems capable of performing sequential determinations with several ion-selective
electrodes. The assessment of its analytical usage and behaviour are discussed. 相似文献
59.
André Revillon 《Journal of Coatings Technology》2002,74(930):55-63
This paper presents an academic analysis of recent progress and changes in polymer science. These changes influence the coatings
industry, as an answer to various constraints, such as enhanced applicability, quality certification, safety, and care of
environment. We do not focus on a specific topic but instead consider the basic concepts, the chemical advances in polymer
synthesis, and progress in fine characterization methods. Experimental results in polymerization, analysis, and new processes,
obtained in recent years, in the final period of my laboratory activity, are illustrated.
Presented at the 79th Annual Meeting of the Federation of Societies for Coatings Technology, in Atlanta, GA, Nov. 5–7, 2001.
200 Avenue Félix Faure, F-69003-Lyon, LMOPS, 69390 Vernaison on behalf of AFTPVA, France, email: arevillon@gonline.fr. 相似文献
60.
André Girard Pierre Dominique Lansard Bernard Liau Anne Marie Mongeon Jean Luc Thibault 《电信纪事》1991,46(5-6):335-350
Classical hierarchical routing in telephone networks is extended to a wider class called out-of-chain routing in such a way that some useful properties of hierarchical routing are retained. This new routing pattern offers more potential paths than the fixed hierarchical one and can be introduced as a dynamic routing where the fixed alternate sequences change at some predetermined instants during the day. The effect of this new routing pattern on the network performances is examined. The main topic of this paper is to present heuristic methods used to optimise such routings in large networks. We show on artificial networks that the throughput of a given network can be significantly improved by suitable routing choices. We demonstrate that the integration of routing changes within a multihour dimensioning process is possible but the lack of realistic data does not permit at this time to quantify the value of routing optimization on real networks. 相似文献