排序方式： 共有48条查询结果，搜索用时 15 毫秒
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NATASHA M. WERPY CHARLES P. HO CHRISTOPHER E. KAWCAK 《Veterinary radiology & ultrasound》2010,51(1):2-10
Distal forelimb specimens of eight skeletally mature horses were imaged using proton density turbo spin echo, T1-weighted spoiled gradient echo, T2* -weighted gradient echo, short tau inversion recovery and T2-weighted fast spin echo sequences with the limb parallel to the main magnetic field, and with angulation of the limb relative to the main magnetic field. The magic angle effect can be identified in the collateral ligaments of the distal interphalangeal joint when imaged in a high-field magnetic resonance (MR) imaging system with a horizontally oriented main magnetic field. This effect has previously been described in the collateral ligaments of the distal interphalangeal joint in a low-field system with a vertically oriented main magnetic field. The curvature of the ligaments places the fibers at the magic angle in both horizontally and vertically orientated main magnetic fields. This effect can be identified on short time of echo sequences and impacts the signal pattern of the ligaments at the level of the middle phalanx with the limb in a neutral position and with angulation of the limb. Magic angle effect should be considered as a possible cause of an asymmetrical signal pattern, depending on the positioning of the limb and the sequences used for imaging, when evaluating the collateral ligaments of the distal interphalangeal joint on images acquired with a high-field MR imaging system that has a horizontally oriented main magnetic field. 相似文献
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ABSTRACT: Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in four and five specimens of new toxic xanthid crab Xanthia lividus collected from Lanyu, south-east Taiwan in April 1999 and Hsiaoliuchiu south-west Taiwan in November 1999, respectively. The average toxicity of crab specimens collected from Lanyu and Hsiaoliuchiu was 230 ± 94 (mean ± SD) mouse units (MU) and 241 ± 114 MU, respectively. The toxin was partially purified by YM-1 membrane ultrafiltration and Bio-Gel P-2 column chromatography. Electrophoresis, high-performance liquid chromatography and gas chromatography–mass spectroscopy analyses showed that the crab toxin was composed mainly of tetrodotoxin (83%), as well as a small amount of gonyautoxin 1-4 (17%). 相似文献
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Electrical vagus nerve stimulation (VNS) has been approved by FDA and is widely used in recent years for the treatment of epilepsy and possibly other medical conditions such as depression. The current success rate of VNS for epilepsy is about 50%, but there are complications, potential risks and cost concerns. One of the major limitations for this new therapy is that its antiseizure mechanisms are by no means clear. In particular, it is not known whether the therapeutic effect is vagal specific, what types of nerve fibers in the vagus nerve are contributing to the therapeutic effects, or what individual patients would benefit from the use of the expensive and invasive VNS implantation. There are controversies regarding how and where the VNS takes effect on epilepsy in the central nervous system. The poor understanding of VNS has inevitably limited the application and success of the therapy. The current review analyses the pros and cons of VNS for epilepsy in vis-à-vis other available therapies including Chinese medical methods, and explores the possible mechanisms in order to stimulate further improvement of this new technology. 相似文献
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MATTHEW T. BROKKEN ROBERT K. SCHNEIDER SARAH N. SAMPSON RUSSELL L. TUCKER PATRICK R. GAVIN CHARLES P. HO 《Veterinary radiology & ultrasound》2007,48(6):507-517
Magnetic resonance (MR) imaging abnormalities in horses with lameness localized to the proximal metacarpal or metatarsal region have not been described. To accomplish that, the medical records of 45 horses evaluated with MR imaging that had lameness localized to either the proximal metacarpal or metatarsal region were reviewed. Abnormalities observed in the proximal suspensory ligament or the accessory ligament of the deep digital flexor tendon included abnormal high signal, enlargement, or alteration in shape. Twenty-three horses had proximal suspensory ligament desmitis (13 hindlimb, 10 forelimb). Sixteen horses had desmitis of the accessory ligament of the deep digital flexor tendon. One horse had desmitis of the proximal suspensory ligament and the accessory ligament of the deep digital flexor tendon on the same limb and one horse had desmitis of the proximal suspensory ligament on one forelimb and desmitis of the accessory ligament of the deep digital flexor tendon on the other forelimb. Four horses did not have abnormalities in the proximal suspensory ligament or accessory ligament of the deep digital flexor tendon. Eighty percent of horses with forelimb proximal suspensory ligament desmitis and 69% of horses with hindlimb proximal suspensory ligament desmitis returned to their intended use. Sixty-three percent of horses with desmitis of the accessory ligament of the deep digital flexor tendon were able to return to their intended use. MR imaging is a valuable diagnostic modality that allows diagnosis of injury in horses with lameness localized to the proximal metacarpal and metatarsal regions. The ability to accurately diagnose the source of lameness is important in selecting treatment that will maximize the chance to return to performance. 相似文献
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在澳门半岛选取土地利用为公园绿地和商住混合的2个分流制城市小流域.于2005-08～2005-11借助自动采样器进行流域出口5场降雨地表径流水质水量监测.结果表明,商住混合分流制小流域TN、TP、COD多场降雨平均浓度值分别超出国家地表水环境V类标准4倍以上.公园绿地小流域TN、TP均超出V类水标准2倍多.从降雨-径流过程污染物浓度历时变化看,2个小流域TN和TP呈现一定的初始冲刷现象.TSS与TN、TP的判定系数R2都在0.95以上,地表径流中水土流失与总氮总磷输出显 相似文献
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