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Radiofrequency (RF) energy has many advantages in thermal tumor ablation protocols. With the recent development of open MRI systems, interventional MRI procedures, including thermal ablation, have become the focus of great research interest. However, the significant interference between RF generators and MR imagers has prevented simultaneous imaging and RF ablation and, until now, has limited the role of RF-based thermal therapy in interventional MRI. Here, a simple switching circuit designed with consideration of patient safety provides compatibility between open MRI systems and RF thermal lesion generators. The experimental results show that the switching circuit allows imaging during RF ablation and opens new opportunity for MR-guided thermal therapy. 相似文献
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SJ Maygarden DB Novotny DE Johnson CN Powers WJ Frable 《Canadian Metallurgical Quarterly》1994,10(2):175-179
OBJECTIVE: To determine the relationship of serum theophylline concentration with electrolyte and glucose abnormalities across a broad range of theophylline concentrations. DESIGN: Retrospective review of a computerized laboratory database between June 1, 1984 and June 1, 1986. SETTING: A midwestern university medical center. PATIENTS: Eight hundred sixty-nine patients with serum theophylline concentrations of > 5.5 mumol/L and a random unmatched sample (control group) of 350 in- and outpatient adults and children with no history of reactive airways disease or theophylline exposure. RESULTS: Patients with measurable theophylline had a higher risk of hypokalemia, hyponatremia, hyperglycemia, hypophosphatemia, and hypomagnesemia compared with the unexposed control group. Unadjusted odds ratios (OR) were: (1) hypokalemia OR = 4.2 (95 percent CI 2.2 to 7.9); (2) hyponatremia OR = 5.4 (95 percent CI 2.0 to 12.9); (3) hypomagnesemia OR = 1.6 (95 percent CI 1.0 to 2.5); (4) hyperglycemia OR = 2.3 (95 percent CI 1.7 to 3.0); and (5) hypophosphatemia OR = 2.7 (95 percent CI 1.2 to 5.3). A linear concentration-response relationship was documented between serum theophylline concentration and all metabolic disturbances. CONCLUSIONS: Measurable theophylline was associated with increased risk for glucose and electrolyte abnormalities in a concentration-related fashion across a broad range of theophylline concentrations from 5.5 to > or = 110 mumol/L. 相似文献
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SH Goh D Driedger S Gillett DE Low SM Hemmingsen M Amos D Chan M Lovgren BM Willey C Shaw JA Smith 《Canadian Metallurgical Quarterly》1998,36(7):2164-2166
It was recently reported that Streptococcus iniae, a bacterial pathogen of aquatic animals, can cause serious disease in humans. Using the chaperonin 60 (Cpn60) gene identification method with reverse checkerboard hybridization and chemiluminescent detection, we identified correctly each of 12 S. iniae samples among 34 aerobic gram-positive isolates from animal and clinical human sources. 相似文献
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The Hrp (type III protein secretion) system is essential for the plant parasitic ability of Pseudomonas syringae and most Gram-negative bacterial plant pathogens. AvrB and AvrPto are two P. syringae proteins that have biological activity when produced via heterologous gene expression inside plant cells or when produced by Hrp+ bacteria. Avr-like proteins, presumably injected by the Hrp system on bacterial contact with plant cells, appear to underlie pathogenic interactions, but none has been observed outside of the bacterial cytoplasm, and identifying novel genes encoding them is tedious and uncertain without a phenotype in culture. Here we describe a cloned Hrp secretion system that functions heterologously in Escherichia coli to secrete AvrB and AvrPto in culture and to promote AvrB and AvrPto biological activity in inoculated plants. The hrp gene cluster, carried on cosmid pCPP2156, was cloned from Erwinia chrysanthemi, a pathogen that differs from P. syringae in being host promiscuous. E. coli DH5alpha carrying pCPP2156, but not related Hrp-deficient cosmids, elicited a hypersensitive response in Nicotiana clevelandii only when also expressing avrB in trans. The use of pAVRB-FLAG2 and pAVRPTO-FLAG, which produce Avr proteins with a C-terminal FLAG-epitope fusion, enabled immunoblot detection of the secretion of these proteins to E. coli(pCPP2156) culture media. Secretion was Hrp dependent, occurred without leakage of a cytoplasmic marker, and did not occur with E. coli(pHIR11), which encodes a functional P. syringae Hrp system. E. coli(pCPP2156) will promote investigation of Avr protein secretion and systematic prospecting for the effector proteins underlying bacterial plant pathogenicity. 相似文献