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PM Murphy 《Canadian Metallurgical Quarterly》1997,11(2):246-249
TEE is an expensive but useful intraoperative diagnostic strategy for cardiac surgical procedures. It can alter surgical management with tremendous potential benefits to the patient. It also has the potential to avoid unnecessary surgery and reduce the risk of complications such as reoperation, thromboembolism, and stroke. As with any new technology, the indications for its use must be evaluated on the basis of cost, benefits, and efficacy to determine the true value and cost-effectiveness in a particular application. Based on the information presented in this report, it can be concluded that TEE is a cost-effective strategy for valvular and congenital heart repairs. Current data are very convincing that TEE has the potential to be cost-effective in reducing the risk of stroke in selected populations of cardiac surgical patients. As experience with the use of TEE in its various applications increases and the technology itself continues to improve, it will undoubtedly become a more valuable and cost-effective strategy for cardiac surgery. 相似文献
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The evidence for and against the prophylactic use of anticonvulsants and antibiotics in head injury is reviewed. There is a lack of blinded placebo-controlled trials in this area. On balance there is no compelling evidence to support the use of either anticonvulsant or antibiotic prophylaxis in head injury, with the possible exception of antibiotic prophylaxis in compound depressed skull fractures and penetrating brain injuries. 相似文献
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Linear control design techniques for output setpoint tracking of regulation problems can be extended, through input output feedback linearization (IOFL), to non-linear, input-affine systems, but are not applicable to the case of equilibrium points that exhibit non-minimum phase characteristics. Rather than resort to minimum phase approximations, this paper instead proposes a relaxation of IOFL that does not require IOFL to be implemented at every sampling instant. The relaxation introduces degrees of freedom which, in the case of bilinear systems, can be used efficiently to achieve tracking/regulation, and to maintain this property (to within perturbations caused by the relaxation) until the desired state is reached. A way for expanding the region of attraction is considered and the results of the paper are demonstrated through simulation examples. 相似文献
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Surgical management of locally recurrent rectal cancer 总被引:3,自引:0,他引:3
The surgical management of locally recurrent rectal cancer may involve major procedures and is not for the faint-hearted. Nevertheless, such treatment is preferable to chemotherapy and radiotherapy; the latter will fail over a period of months during which the patient is likely to experience intractable pain. Radical surgery offers good palliation and a better quality of life. Survival is prolonged by such operations which may be curative in up to one-third of patients. Nevertheless, surgeons must be realistic in their assessment of and discussions with patients. 相似文献