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181.
Two cases of pseudo-tandem stenosis of the internal carotid artery are presented. Proximal stenosis was produced by a large, focal atherosclerotic plaque. The severe intracranial "stenosis" was thought to be an angiographic artifact. Repeat cerebral angiography after carotid endarterectomy revealed normal intracranial arteries. The recognition of this entity is important because a decision to operate is based largely upon angiographic findings. 相似文献
182.
JR Krause 《Canadian Metallurgical Quarterly》1977,70(9):1072-4, 1079
Amyloid involvement of the bone marrow is not commonly diagnosed before necropsy. Paraffin sections of the trephine bone biopsy specimen are superior to marrow aspiration cell smears for the antemortem diagnosis. Thirteen cases of amyloidosis were diagnosed from the bone biopsy specimen during a ten-year period. Amyloid was detected in only two of the corresponding aspirates. Three morphologic patterns of marrow involvement were found: vascular, focal extravascular/perivascular, and diffuse. Five (38%) of the cases were associated with multiple myeloma. An abnormal immunoglobulin was detected in the serum or urine or both in ten of 11 cases when determined. Although the bone marrow may not be the best site for the diagnosis of amyloidosis, it should not be neglected and marrow biopsies taken for other diagnostic reasons may "incidentally" reveal amyloid. Amyloidosis should be included in the list of non-primary hematologic conditions of the bone marrow in which the trephine biopsy may prove useful for diagnosis. 相似文献
183.
JR Bearder VM Frydman P Gaskin IK Hatton WE Harvey J McMillan BO Phinney 《Canadian Metallurgical Quarterly》1976,39(2):178-183
Angiotensin II (A II) and analogues were tested for their ability to restore electrical and mechanical activity to cardiac muscle preparations in which the fast Na+ channels had been inactivated by partial depolarization (22-27 mM K+) or by tetrodotoxin (TTX). The partially depolarized or TTX-blocked preparations were chosen because under these conditions electrical and mechanical responses are primarily Ca2+ -dependent. In depolarized rabbit right atria, A II restored spontaneous mechanical and electrical activity (measured by both intracellular and extracellular recording techniques). The frequency of action potential discharge was concentration-dependent; the threshold concentration of A II was 10(-10) M, the ED50 was 8 X 10(-9) M, and the maximum effect was observed at 5 X 10(-8) M. In contrast, depolarized guinea pig atria were insensitive to A II, Sar1-angiotensin II, and des-Asp1-angiotensin II, even at concentrations as high as 10(-5) M. Rabbit papillary muscle (TTX-blocked), embryonic (18-day) chick heart (partially depolarized) and chick heart reaggregates (TTX-blocked) responded similarly to rabbit atria in that A II (9.6 X 10(-7) M) restored both electrical and mechanical activity. We found that in these preparations the action of A II was unaffected by propranolol (5.0 X 10(-6) M to 5.0 X 10(-5) M) but was blocked by Mn2+ (10(-3) M), D-600 (1 X 10(-7) g/ml) and the specific A II antagonists Sar1-Ala8-angiotensin II (P-113) (5.0 X 10(-5) M) and Sar1-Ile8-angiotensin II (5.28 X 10(-5) M). We conclude that the positive inotropic effect of A II on the myocardium is due to its ability to increase transmembrane ion movements in or through the cell membrane. The ability of Mn2+ and D-600 to block this effect suggests that this ion movement is via the so-called "slow channels." 相似文献
184.
Terminal chromosome associations ("satellite associations") in ASG-banded preparations have been used to determine the number and location of staellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that corrrespondence also occurs in this species. 相似文献
185.
This article enhances the notion of city‐making by explicating its communicative processes and functions within the press. Through a quantitative content analysis and qualitative textual analysis of Miami Herald news coverage related to incorporation and annexation policies and practices over a period of 3 years, we argue for a stronger implication of the press in coverage of local policy‐ and place‐making. Through a quantitative content analysis of 437 articles from the Miami Herald about communities affected by incorporation and annexation and a qualitative textual analysis of 51 articles related to general coverage of geographic policy‐making in Miami‐Dade County over a 3‐year period, we argue that this coverage reveals the press as being a central feature and function of policy‐making through the lens of city‐making. 相似文献
186.
Rafael K. de Andrades Márcio Dorn Daniel S. Farenzena Luis C. Lamb 《Expert systems with applications》2013,40(13):5210-5218
The Medical and Pharmaceutical industries have shown high interest in the precise engineering of protein hormones and enzymes that perform existing functions under a wide range of conditions. Proteins are responsible for the execution of different functions in the cell: catalysis in chemical reactions, transport and storage, regulation and recognition control. Computational Protein Design (CPD) investigates the relationship between 3-D structures of proteins and amino acid sequences and looks for all sequences that will fold into such 3-D structure. Many computational methods and algorithms have been proposed over the last years, but the problem still remains a challenge for Mathematicians, Computer Scientists, Bioinformaticians and Structural Biologists. In this article we present a new method for the protein design problem. Clustering techniques and a Dead-End-Elimination algorithm are combined with a SAT problem representation of the CPD problem in order to design the amino acid sequences. The obtained results illustrate the accuracy of the proposed method, suggesting that integrated Artificial Intelligence techniques are useful tools to solve such an intricate problem. 相似文献
187.
Abstract Error-diffused quantization has been applied to the generation of cell-oriented computer-generated Fourier transform holograms, resulting in reduced reconstruction errors. Improvements are demonstrated when applied to the algorithms of Lohmann, Lee and Burckhardt after invoking realistic constraints on the minimum size of the printable spot for an electrophotographic laser printer. 相似文献
188.
Simon D. Hodgson William S. M. Brooks Andrew J. Clayton Giray Kartopu Daniel A. Lamb Vincent Barrioz Stuart J. C. Irvine 《Progress in Photovoltaics: Research and Applications》2015,23(2):150-159
Commercially available quantum dots have been encapsulated in a poly(methyl methacrylate) film and used as a luminescent downshifting layer on cadmium sulfide/cadmium telluride photovoltaic devices. Application of these films has resulted in a relative improvement to the short‐circuit current of over 4% by I–V measurement, with a significant increase in the contribution of short‐wavelength light resulting in 25% of the current available in this part of the spectrum being captured. The films have been shown to be highly scattering and the associated difficulties this provides to external quantum efficiency measurements have been discussed. A range of optical characterisation techniques, particularly laser beam induced current, have been used to probe the effect the films have on a cadmium sulfide/cadmium telluride device. An alternate methodology for performing external quantum efficiency measurements with the quantum dot films has been proposed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
189.
An analysis of dilute, turbulent particle/liquid two-phase flow is presented. The three-dimensional conservation equations that govern turbulent motion in solid/fluid flows are derived using ensemble averaging, and the unknown terms in these equations are constituted to achieve closure. These closure terms include the shear stress due to interparticle collisions, the corresponding terms in the Reynolds stress equation, the force and dissipation due to particle-wall collisions, and the interfacial work due to particle/turbulent eddy interaction. The resultant two-fluid model was then evaluated using a computational fluid dynamic (CFD) solver and the predictions were compared with experimental data. Good agreement was observed for a variety of flow conditions. 相似文献
190.
THE DESIGN OF EXPERIMENTS FOR SHELF LIFE STUDY 总被引:13,自引:0,他引:13