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The 1 /fα noise was measured on a variety of Al-based thin metal films with widely varying microstructure using an ac bridge technique.
The magnitude of the current noise in response to a small, non-destructive ac signal was found to vary several orders of magnitude
between 0.01 and 10 Hz and was correlated to the microstructural differ-ences of the films. These differences have a strong
affect on film lifetimes as measured in an accelerated electromigration test. Variation in microstructure was accomplished
by different deposition temperatures and annealing parameters, and verified using TEM micrographs. Following fabrication,
the current noise magnitude was measured and found to be sensitive to film width and grain size. The use of this technique
to discriminate differences in film microstructure is discussed along with the correlations between ex-cess noise and the
quality of the thin film as a metallic interconnection. 相似文献
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OBJECTIVES: This study sought to identify risk markers associated with the provision of new restorations in children and to investigate whether the carious status of a tooth surface is associated with the restorative decisions of dentists. METHODS: A total of 911 schoolchildren in grades one, two, and three were randomly selected from the island of Montreal, Quebec, Canada. Dental examinations were carried out in 1990, 1991, and 1992. Tooth surfaces of first permanent molars were classified as sound, noncavitated, and cavitated. The carious status of a tooth was matched with restorative decisions reported to the insurance board. RESULTS: The presence of a carious cavity was a strong risk marker for placement of new restorations (odds rations > or = 4.11). After one year, less than 2 percent of sound tooth surfaces of first permanent molars were restored and about 21 percent of noncavitated tooth surfaces were restored. When new class I restorations placed in maxillary first permanent molars within 3-6 months after the baseline examination were evaluated, we found that between 73 percent and 86 percent of these new restorations were placed in sound or noncavitated tooth surfaces. A similar trend also was observed in mandibular first permanent molars. Poor agreement between epidemiologic diagnosis and restorative decisions was found. The restorative profile of dentists was a significant risk marker for placement of new restorations. CONCLUSION: The majority of new restorations in first permanent molars were placed in sound and noncavitated tooth surfaces because of the ubiquitous prevalence of these tooth surfaces and the validity problems of current caries diagnosis methods. 相似文献
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PR Burchat GJ Feldman T Barklow AM Boyarski DL Burke JM Dorfan L Gladney G Hanson K Hayes RJ Hollebeek WR Innes JA Jaros D Karlen AJ Lankford RR Larsen BW LeClaire NS Lockyer V Lüth C Matteuzzi RA Ong ML Perl B Richter K Riles MC Ross JM Yelton C Zaiser GS Abrams D Amidei AR Baden J Boyer F Butler G Gidal MS Gold G Goldhaber L Golding J Haggerty D Herrup I Juricic JA Kadyk ME Nelson PC Rowson H Schellman WB Schmidke PD Sheldon GH Trilling de la Vaissiere C DR Wood ME Levi T Schaad 《Canadian Metallurgical Quarterly》1987,35(1):27-41
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Massive hemorrhage caused by a perforating Gianturco-Z stent resulting in an aortoesophageal fistula
PD Siersema TG Tan FF Sutorius J Dees M van Blankenstein 《Canadian Metallurgical Quarterly》1997,29(5):416-420
Squamous cell carcinoma of the tonsil has a relatively poor prognosis. Aggressive surgery, radiation therapy and combinations of irradiation and surgery have been employed but there exists some controversy about the efficacy of these treatment modalities. The purpose of this paper is to compare the efficacy of treatment between the surgery followed by radiation therapy and the preoperative radiation therapy followed by surgical resection. The medical records of 33 patients treated for squamous cell carcinoma of the tonsil at the Department of Otolaryngology-Head and Neck Surgery, Korea University Hospital between 1989-1993 were reviewed retrospectively. None of the patients were stage I, but stage II, III, and IV were four, five, and 24 patients, respectively. There were 30 males and three females. The most common histopathology was moderately differentiated squamous cell carcinoma (20/33). The 13 patients treated initially with surgery had an overall three-year survival rate of 38.5%, and the rate for the 20 patients treated initially with radiation was 40%. The main pattern of treatment failure was a local recurrence and neck metastases, and pathologic differentiation thought to be an important prognostic factor. Complications are fewer in patients treated initially with surgery (23.1%) than patients initially treated with radiation (50.0%). There is no difference in the efficacy between the two therapeutic groups. 相似文献
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JP Vuillez E Levrot M Mousseau PD Buffaz M Bolla R Payan M Comet R Schaerer 《Canadian Metallurgical Quarterly》1997,84(11):1033-1042
Immunoscintigraphy using indium-111-labeled OC125 monoclonal antibody F(ab')2 fragments is a technic complementary of morphological imaging (i.e. ultrasonography and computed tomography). It allows early detection of recurrences of ovarian carcinomas. We performed immunoscintigraphy 30 times in 26 patients who previously underwent radical treatment for ovarian carcinoma, and were suspected to have a recurrence. Our purposes were appreciation of diagnostic accuracy of the method, and above all its impact on clinical decisions and evolution of the patients. There were, after reevaluation of the results, 18 true positives, 7 true negatives, 3 false negatives and 2 false positive cases (sensitivity 85.7%, specificity 77.8%). Bayesian analysis showed positive and negative predictive values of 86% and 87% when probability of recurrence a priori was 50%, and 80% and 58% when probability of recurrence a priori was 70%. The result of immunoscintigraphy contributed to clinical decisions in 24 cases out of 30, and led to a correct decision for the patient in 21 cases. Conversely, for the 6 cases in which the result has not been considered, to take this result into account would have been beneficial in 4 cases, but harmful in 2. Finally, survival tended to be longer when immunoscintigraphy was negative, which could be associated with a better prognosis. We conclude that OC125-immunoscintigraphy may be useful for ovarian carcinoma follow-up and may contribute to a better therapeutic strategy. 相似文献