Phased Array
Mostrando 13-24 de 31 artigos, teses e dissertações.
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13. Analysis of regional left ventricular wall movement by phased array echocardiography.
Images from standard two-dimensional echocardiographs do not lend themselves to the study of regional left ventricular wall movement because of poor definition of endocardium. An alternative method, based on a wide-angle phased array sector scanner has, therefore, been devised. Once the appropriate region of the heart has been identified, the scan rate is in
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14. Transoesophageal cross-sectional echocardiography with a phased array transducer system. Technique and initial clinical results.
Cardiac imaging by transthoracic two dimensional echocardiography is impaired in patients with chronic lung disease, those with obesity, and those with abnormal chest wall configuration. In order to overcome these limitations, a miniature phased array ultrasound transducer fitted to the tip of a commercially available gastroscope was developed. Transducer po
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15. Multiple matching scheme for broadband 0.72Pb(Mg1∕3Nb2∕3)O3−0.28PbTiO3 single crystal phased-array transducer
Lead magnesium niobate–lead titanate single crystal 0.72Pb(Mg1∕3Nb2∕3)O3−0.28PbTiO3 (abbreviated as PMN-PT) was used to fabricate high performance ultrasonic phased-array transducer as it exhibited excellent piezoelectric properties. In this paper, we focus on the design and fabrication of a low-loss and wide-band transducer for medical imaging appli
American Institute of Physics.
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16. High resolution magnetic resonance imaging of the anterior visual pathway in patients with optic neuropathies using fast spin echo and phased array local coils.
High resolution MRI of the anterior visual pathways was evaluated using frequency selective fat suppressed fast spin echo (FSE) sequences in conjunction with phased array local coils in patients with optic neuropathies. Fifteen normal controls and 57 patients were examined. Coronal T2 weighted fat suppressed FSE images were obtained in 11 minutes with an in
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17. Rotational excursion of heart in massive pericardial effusion studied by phased-array echocardiography.
We have observed rotational excursion, comprising anteroposterior and right to left movement of the heart, and cardiac twist around the long axis in 2 patients with massive pericardial effusion, using a phased-array echocardiograph recently developed in this country. Sagittal real-time cross-sections showed only the anteroposterior swing motion, but horizont
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18. Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8 Transcriptional Activator Rta Is an Oligomeric DNA-Binding Protein That Interacts with Tandem Arrays of Phased A/T-Trinucleotide Motifs
Kaposi's sarcoma associated herpesvirus (KSHV)/human herpesvirus 8 (HHV-8) encodes an immediate early transcriptional activator, Rta, which mediates viral reactivation from latency and lytic viral replication. Here we report the purification and characterizations of HHV-8 Rta and its interaction with Rta-responsive DNA elements. The Rta response element (Rta
American Society for Microbiology.
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19. Three dimensional reconstruction of the left ventricle from multiple cross sectional echocardiograms. Value for measuring left ventricular volume.
The accuracy of a system for reconstructing a three dimensional image of the left ventricle from randomly recorded multiple short axis images was tested by comparing the calculated left ventricular volume with the directly measured left ventricular volume in 11 excised porcine hearts. The system comprised a real time phased array sector scanner, a transducer
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20. CENP-A, -B, and -C Chromatin Complex That Contains the I-Type α-Satellite Array Constitutes the Prekinetochore in HeLa Cells
CENP-A is a component of centromeric chromatin and defines active centromere regions by forming centromere-specific nucleosomes. We have isolated centromeric chromatin containing the CENP-A nucleosome, CENP-B, and CENP-C from HeLa cells using anti-CENP-A and/or anti-CENP-C antibodies and shown that the CENP-A/B/C complex is predominantly formed on α-satelli
American Society for Microbiology.
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21. Ocular blood flow velocities in patients with proliferative diabetic retinopathy and healthy volunteers: a prospective study.
BACKGROUND--Diabetes affects the vascular ocular circulation. Colour Doppler imaging allows for simultaneous two dimensional anatomical imaging and Doppler evaluation of blood flow velocity; with this technique ocular blood flow velocity can be evaluated in normal and diabetic patients. METHODS--A prospective study compared blood flow velocity in ocular vess
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22. Echocardiographic evaluation of atrial function after Senning and Mustard correction for transposition of the great arteries.
Two groups of six children who had undergone either Senning or Mustard repair for uncomplicated transposition of the great arteries were studied with M mode echocardiography derived from a phased array sector scanner picture. The newly created atria were visualised from the subxiphoid region and the upper systemic venous inflow was selected for a simultaneou
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23. An approach to three-dimensional structures of biomolecules by using single-molecule diffraction images
We describe an approach to the high-resolution three-dimensional structural determination of macromolecules that utilizes ultrashort, intense x-ray pulses to record diffraction data in combination with direct phase retrieval by the oversampling technique. It is shown that a simulated molecular diffraction pattern at 2.5-Å resolution accumulated from m
The National Academy of Sciences.
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24. Evidence that nucleosomes on the mouse mammary tumor virus promoter adopt specific translational positions.
We have previously demonstrated that an array of six nucleosomes are phased on the mouse mammary tumor virus (MMTV) long terminal repeat (1,2). In this study, we devised a new assay to measure the translational positions of specific nucleosomes on the MMTV promoter. Nucleosome core particles were purified and shown to contain A and B nucleosomal DNA by Taq p