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排序方式: 共有5643条查询结果,搜索用时 15 毫秒
61.
DM Kulibaba VN Novozhilov EG Tsvetkov VG Medvedev 《Canadian Metallurgical Quarterly》1997,156(2):117-118
Access and visualization in the implant-abutment area are often compromised. Tissue impingement and lack of abutment position verification may result in inaccurate fit. 相似文献
62.
The reactions of immunoglobulins with protein A and, subsequently, of antibodies to these immunoglobulins were continuously monitored by a piezoelectric biosensor. AT-cut crystals, with a fundamental resonant frequency of 10 MHz, were mounted in a Plexiglas holder, and one side was directly coated with protein A. Upon exposure to solutions containing rabbit or human IgG the resonant frequency was followed continuously and its decrease due to the binding of IgG to protein A observed. Subsequent addition of sheep antihuman IgG to the now immobilized human IgG caused a specific 3-fold further decrease in resonant frequency. We observed a frequency change of approximately 1 Hz fore each 10 ng of added immunoglobulin. Decreasing the pH to 3 released the bound IgG but not the protein A and permitted reuse of the crystal for further IgG binding. 相似文献
63.
An adaptive optical sequence generation scheme has been described in a nonlinear optical ring which exhibits chaotic dynamics. The adaptation is based on avoidance of collisions between the ring output and signals from another source. It is shown that collision-avoiding sequences can be autonomously selected via chaotic mode transitions induced by the feedback of collision signals. Experimental results demonstrate that the method can be successful for various collision signal patterns with different periods and pulsewidths. The mechanism of inducing chaos with collision signals is examined both experimentally and with numerical simulations and the results verify the effectiveness of the proposed adaptation method. A possible application of the proposed signal generation scheme in intelligent optical communication networks is mentioned 相似文献
64.
OBJECTIVE: To study the utility and functional benefits of an implanted functional electrical stimulation (FES) system for hand grasp and release in adolescents with tetraplegia secondary to spinal cord injuries. DESIGN: Intervention study with before-after trial measurement with each subject as his or her own control. SETTING: Nonprofit pediatric orthopedic rehabilitation facility specializing in spinal cord injury. PARTICIPANTS: A convenience sample of five adolescents between 16 and 18 years of age with C5 or C6 level tetraplegia at least 1 year after traumatic spinal cord injury. Key muscles for palmar and lateral grasp and release were excitable by electrical stimulation. INTERVENTIONS: A multichannel stimulator/receiver and eight electrodes were surgically implanted to provide stimulated palmar and lateral grasp and release. In conjunction with implantation of the FES hand system, surgical reconstruction in the form of tendon transfers, tendon lengthenings and releases, and joint arthrodeses was performed to augment stimulated hand function. Rehabilitation of the tendon transfers and training in the use of the FES hand system were provided. MAIN OUTCOME MEASURES: Measurements of pinch and grasp force, the Grasp and Release Test (GRT), and an assessment of six activities of daily living (ADL) were administered before implantation of the FES hand system and at regular follow-up intervals. Results of the stimulated response of individual muscles and surgical reconstruction were evaluated using standard and stimulated muscle testing techniques and standard assessment of joint range of motion. All subjects completed followup testing. RESULTS: Lateral and palmar forces were significantly greater than baseline forces (p = .043). Heavy objects on the GRT could only be manipulated with FES, and FES increased the level of independence in 25 of 30 ADL comparisons (5 subjects, 6 activities) as compared to baseline. After training, FES was preferred in 21 of 30 comparisons over the typical means of task completion. Of the 40 electrodes implanted, 37 continue to provide excellent stimulated responses and all of the implanted stimulators have functioned without problems. The surgical reconstruction procedures greatly enhanced FES hand function by either expanding the workspace in which to utilize FES (deltoid to triceps transfer), stabilizing the wrist (brachioradialis to wrist extensor transfer), or stabilizing joints (intrinsic tenodesis transfer, FPL split transfer). CONCLUSION: For five adolescents with tetraplegia, the combination of FES and surgical reconstruction provided active palmar and lateral grasp and release. Laboratory-based assessments demonstrated that the FES system increased pinch force, improved the manipulation of objects, and typically increased independence in six standard ADL as compared to pre-FES hand function. The study also showed that the five adolescents generally preferred FES for most of the ADL tested. Data on the benefits of the implanted FES hand system outside of the laboratory are needed to understand the full potential of FES. 相似文献
65.
We present a new background-subtraction technique fusing contours from thermal and visible imagery for persistent object detection in urban settings. Statistical background-subtraction in the thermal domain is used to identify the initial regions-of-interest. Color and intensity information are used within these areas to obtain the corresponding regions-of-interest in the visible domain. Within each region, input and background gradient information are combined to form a Contour Saliency Map. The binary contour fragments, obtained from corresponding Contour Saliency Maps, are then fused into a single image. An A* path-constrained search along watershed boundaries of the regions-of-interest is used to complete and close any broken segments in the fused contour image. Lastly, the contour image is flood-filled to produce silhouettes. Results of our approach are evaluated quantitatively and compared with other low- and high-level fusion techniques using manually segmented data. 相似文献
66.
We conducted a review to investigate the prevalence of human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome (AIDS), in patients with herpes zoster ophthalmicus, as well as the incidence of acute retinal necrosis after herpes zoster ophthalmicus. All charts of patients seen at our institution between 1987 and 1992 with a primary diagnosis of herpes zoster ophthalmicus were reviewed. Of 112 patients with herpes zoster ophthalmicus, 29 (26%) had HIV or AIDS. All these patients were younger than 50 years at the time of diagnosis. Five of 29 (17%) immunocompromised patients had acute retinal necrosis after herpes zoster ophthalmicus. No acute retinal necrosis was identified in the nonimmunocompromised patients after herpes zoster ophthalmicus. We recommend that all patients younger than 50 years who have herpes zoster ophthalmicus at initial examination be tested for HIV. Additionally, HIV-infected patients should be monitored closely after herpes zoster ophthalmicus for development of acute retinal necrosis. Long-term oral prophylactic as well as initial high-dose intravenous acyclovir may be appropriate in HIV-infected individuals with herpes zoster. 相似文献
67.
68.
RJ Mayer RB Davis CA Schiffer DT Berg BL Powell P Schulman GA Omura JO Moore OR McIntyre E Frei 《Canadian Metallurgical Quarterly》1994,331(14):896-903
BACKGROUND: About 65 percent of previously untreated adults with primary acute myeloid leukemia (AML) enter complete remission when treated with cytarabine and an anthracycline. However, such responses are rarely durable when conventional postremission therapy is administered. Uncontrolled trials have suggested that intensive postremission therapy may prolong these complete remissions. METHODS: We treated 1088 adults with newly diagnosed AML with three days of daunorubicin and seven days of cytarabine and randomly assigned patients who had a complete remission to receive four courses of cytarabine at one of three doses: 100 mg per square meter of body-surface area per day for five days by continuous infusion, 400 mg per square meter per day for five days by continuous infusion, or 3 g per square meter in a 3-hour infusion every 12 hours (twice daily) on days 1, 3, and 5. All patients then received four courses of monthly maintenance treatment. RESULTS: Of the 693 patients who had a complete remission, 596 were randomly assigned to receive postremission cytarabine. After a median follow-up of 52 months, the disease-free survival rates in the three treatment groups were significantly different (P = 0.003). Relative to the 100-mg group, the hazard ratios were 0.67 for the 3-g group (95 percent confidence interval, 0.53 to 0.86) and 0.75 for the 400-mg group (95 percent confidence interval, 0.60 to 0.94). The probability of remaining in continuous complete remission after four years for patients 60 years of age or younger was 24 percent in the 100-mg group, 29 percent in the 400-mg group, and 44 percent in the 3-g group (P = 0.002). In contrast, for patients older than 60, the probability of remaining disease-free after four years was 16 percent or less in each of the three postremission cytarabine groups. CONCLUSIONS: These data support the concept of a dose-response effect for cytarabine in patients with AML who are 60 years of age or younger. The results with the high-dose schedule in this age group are comparable to those reported in similar patients who have undergone allogeneic bone marrow transplantation during a first remission. 相似文献
69.
Classroom Presenter is a Tablet PC-based interaction system that supports the sharing of digital ink on slides between instructors and students. Initial deployments show that using the technology can achieve a wide range of educational goals and foster a more participatory classroom environment. 相似文献
70.
An overview of the most important older and newer results regarding the relationship between violent and criminal behavior on the one hand and schizophrenic illness on the other hand is presented. Four different methods are available to study this relationship: (i) study of the prevalence of mental illness in criminal/violent populations; (ii) study of criminality/violence rate in samples of psychiatric patients; (iii) study of criminality/violence in community samples comparing mental patients with non-patient community residents; and (iv) study of criminality/violence in birth cohorts prospectively. All these methods have been used; but samples composed of schizophrenic patients exclusively were only exceptionally studied. The results indicate that there is a modest but significant relationship between schizophrenia and violence and crime which persists even after controlling for demographic and socio-economic variables. The probability of schizophrenic patients to be criminal or violent depends on the acuity of their illness and is increased by their use of psychoactive substances. Generally, however, violent and criminal acts directly attributable to mental illness account only for a very small proportion of such acts in the society. 相似文献