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81.
Automated focimeters can be used to make quick, precise measurements of off-axis power and prismatic effects corresponding to an eye rotating behind a spectacle lens. An automated focimeter, the Humphrey Lens Analyzer, was assessed in this regard. The Humphrey Lens Analyzer can be used to give a valid measure of off-axis power of lenses with low power, but not of lenses with moderate to higher power (greater than 3 D). For 3 D spherical lenses discrepancies of the order of 0.1 D occur at 30 degrees rotation, and 6 D spheres give discrepancies of 0.5 D at the same rotation. Small discrepancies were found for measurements of prism. The Humphrey Lens Analyzer was also used in a mode where the lens being tested is rotated about the center of curvature of its back surface. This is the mode often used to assess aberrations and prism of progressive-addition lenses. In this mode, the instrument provides reasonable accuracy in estimating off-axis power corresponding to eye rotation for lenses with low power, but not for lenses with moderate to higher power (greater than 3 D). However, it provides accurate values of the variation in off-axis surface power for low powered lenses with aspheric front surfaces. There were considerable systematic errors associated with the measurement of prism. A simple raytracing method was developed to predict the results of measurements with the Humphrey Lens Analyzer. Predictions of off-axis power were good when lenses were rotated about a position corresponding to the center-of-rotation of an eye, but were poorer when lenses were rotated about the center of curvature of their back surfaces. Predictions of primatic efforts were good in both situations. A method by which the Humphrey Lens Analyzer should provide an accurate measurement of off-axis powers corresponding to eye rotation behind a spectacle lens is described, but has not been tested. 相似文献
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Patients with penetrating atherosclerotic ulcers of the aorta present with back or chest pain that mimics classic aortic dissection. The pathologic findings, however, are distinctly different from those of aortic dissection in that an atherosclerotic lesion with ulceration penetrates into the internal elastic lamina, allowing hematoma formation within the media of the aortic wall. This may lead to false aneurysm or, rarely, transmural rupture of the aorta. Imaging findings of penetrating aortic atherosclerotic ulcers are also different from those of classic aortic dissection. We have found computed tomography to be especially useful in differentiating between these entities and present several illustrative cases. 相似文献
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Thromboembolic splenic infarction 总被引:1,自引:0,他引:1
J H O'Keefe D R Holmes H V Schaff P F Sheedy W D Edwards 《Mayo Clinic proceedings. Mayo Clinic》1986,61(12):967-972
Splenic infarction occurs as a consequence of systemic thromboembolization in association with several cardiovascular disorders. We describe a case of splenic infarction in a patient who had paroxysmal atrial fibrillation after aortic valve replacement. In an autopsy series of 96 consecutive cases of splenic infarction, only 10% had been suspected clinically even though the splenic infarctions had contributed substantially to morbidity and mortality in 44% of the cases. Thromboembolic causes were responsible for the splenic infarcts in 67% of the cases, and concomitant infarcts in other organ systems were found in 62%. Embolization of atheromatous debris from the aorta, thrombotic elements from the left ventricle (in dilated cardiomyopathy and acute myocardial infarction), and vegetations from infected valves are the most common settings in which thromboembolic splenic infarcts are noted. The clinical picture associated with splenic infarction is typically nonspecific; manifestations may include fever, tachycardia, and left-upper-quadrant tenderness. Computed tomographic scanning and, to a lesser degree, ultrasonography are the imaging techniques of choice for diagnosing splenic infarction. 相似文献
87.
Vasconcelos Rogerio N. Dolan Steven G. Barlow John M. Wells Michael L. Sheedy Shannon P. Fidler Jeff L. Hansel Stephanie Harmsen Scott Fletcher Joel G. 《Abdominal imaging》2017,42(5):1365-1373
Abdominal Radiology - Our purpose is to determine the impact of CT enterography on small bowel gastrointestinal stromal tumor (GIST) detection and biologic aggressiveness, and to identify any... 相似文献
88.
Objective
To examine and compare the extent to which people with type 2 diabetes (T2DM) are achieving haemoglobin A1c (HbA1c), blood pressure (BP) and LDL cholesterol (LDL-C) treatment targets.Methods
A review of databases (MEDLINE Ovid, Pubmed and Sabinet) was performed and limited to the following terms: type 2 diabetes mellitus AND guideline AND goal achievement for the years 2009 to 2014 (five years).Results
A total of 14 studies (25 629 patients) were selected across 19 different countries. An HbA1c level of 7.0% (or less) was achieved by 44.5% of subjects (range 19.2–70.5%), while 35.2% (range 7.4–66.3%) achieved BP of 130/80 mmHg (or less), and 51.4% (range 20.0–82.9%) had an LDL-C level of either 2.5 or 2.6 mmol/l (100 mg/dl or less).Conclusion
Despite guideline recommendations that lowering of HbA1c, BP and lipids to target levels in T2DM will lead to a reduction in morbidity and mortality rates, we found that control of these risk factors remains suboptimal, even across different settings. 相似文献89.
Stimulating spectrum of human recombinant multi-CSF (IL-3) on human marrow precursors: importance of accessory cells 总被引:5,自引:0,他引:5
Recently, human multi-CSF was obtained by molecular cloning. In the present study, the effects of multi-CSF in vitro were investigated by comparative culture of whole bone marrow or progenitor cells obtained by sorting the cell fraction that binds the monoclonal antibody (MoAb) B13C5 (CD 34). Multi-CSF stimulated erythroid (BFU-E), multipotential (CFU-GEMM) and eosinophil (CFU-Eo) colonies in cultures of the progenitor cell enriched fraction, whereas (besides BFU-E, CFU-GEMM, and CFU-Eo) granulocyte (CFU-G), granulocyte-macrophage (CFU-GM), and macrophage (CFU-M) colony-forming cells also were stimulated by multi- CSF when unfractionated bone marrow was cultured. Reconstitution of the progenitor cell fraction (B13C5 positive) with the B13C5-negative population restored the broad spectrum of progenitor cell stimulation. This suggested that accessory cells are required for expression of the full spectrum of progenitor cell stimulation by multi-CSF. Subsequently, specific marrow cell populations, including T lymphocytes, granulocytic cells, and monocytes, were prepared by using selected MoAbs in complement-mediated lysis or cell sorting, added to cultures of hematopoietic progenitors and tested for accessory cell function. The results demonstrate that small numbers of monocytes permit the stimulation of CFU-G, CFU-GM, and CFU-M by multi-CSF. These monocyte-dependent stimulating effects on CFU-G, CFU-GM, and CFU-M could also be achieved by adding recombinant GM-CSF as a substitute for monocytes to the cultures. Therefore, multi-CSF most likely has direct stimulative effects on BFU-E, CFU-GEMM, and CFU-Eo and indirect effects on CFU-G, CFU-GM, and CFU-M in the presence of monocytes. 相似文献
90.
Salwa G Massad FJ Nieto Mari Palta Maureen Smith Roseanne Clark Abdel-Aziz Thabet 《BMC public health》2012,12(1):27