Search results for "Ray"
showing 10 items of 8009 documents
Patent Foramen Ovale and Thromboembolic Complications
2010
The foramen ovale, an atrial septal defect which is essential in the fetal circulation, remains patent through adulthood in approximately 25% of the general population and so it represents the most common persistent abnormality of fetal origin. Patent foramen ovale (PFO) allows interatrial right-to-left blood shunting during those periods of the cardiac cycle in which the right atrial pressure exceeds the left one. An increasing number of pathological manifestations of PFO has been recently identified; among these, paradoxical systemic embolism, refractory hypoxemia in patients with right ventricular myocardium infarction or severe pulmonary disease, orthostatic oxygen desaturation in the r…
Graph-matching based CTA.
2009
Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to subst…
Effect of simulated CO2and GaAlAs laser surface decontamination on temperature changes in Ti-plasma sprayed dental implants
2002
Background and Objective To investigate and compare temperature elevations at the implant-bone interface during simulated implant surface decontamination with a CO2 and a GaAlAs laser. Study Design/Materials and Methods Stepped cylinder implants (Frialit 2® Friadent GmbH, Mannheim, Germany) with a Titanium plasma sprayed surface were inserted into bone blocks cut from pig femurs. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. Both lasers were operated at 1.0–2.5 W in the cw-mode. The bone block was placed into a 37°C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a d…
Bond strength of cemented fiber posts to teeth with simulated internal root resorption
2020
Made available in DSpace on 2021-06-25T10:58:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Background: Teeth with internal root resorption (IRR) have guarded prognosis, considering that IRR defect could influence on the post bond strength. The aim of this study was to evaluate the bond strength and the bond interface between different glass fiber-reinforced posts (FRP) after cementation in teeth with simulated internal root resorption (IRR). Material and Methods: Forty-five (45) human premolar roots with simulated IRR were embedded in acrylic resin blocks and cross-sectioned into two segments, enabling them to be re-approximated by screws. Intracanal medication was inserte…
Canine fossa puncture in endoscopic sinus surgery: report of two cases
2017
Abstract Introduction Chronic rhinosinusitis with nasal polyposis is a common chronic disease that often affects maxillary sinus. Endoscopic sinus surgery is the most common procedure for treating the majority of maxillary sinus lesions. Objective To demonstrate the role of canine fossa puncture during endoscopic sinus surgery procedure in patients with severe maxillary sinus disease. Methods We present 2 cases where canine fossa puncture has been performed as method to obtain a complete access to the maxillary antrum. Results According our experience, 2 cases on 296 endoscopic sinus surgery (0.6%) where antrostomy and used of angled microdebrider were not sufficient, canine fossa puncture …
Effect of chest compressions only during experimental basic life support on alveolar collapse and recruitment
2007
Summary Aim The importance of ventilatory support during cardiac arrest and basic life support is controversial. This experimental study used dynamic computed tomography (CT) to assess the effects of chest compressions only during cardiopulmonary resuscitation (CCO-CPR) on alveolar recruitment and haemodynamic parameters in porcine model of ventricular fibrillation. Materials and methods Twelve anaesthetized pigs (26±1kg) were randomly assigned to one of the following groups: (1) intermittent positive pressure ventilation (IPPV) both during basic life support and advanced cardiac life support, or (2) CCO during basic life support and IPPV during advanced cardiac life support. Measurements w…
Respuesta de preosteoblastos a compuestos de estroncio o calcio: proliferación, diferenciación, mineralización y respuesta génica global
2013
Fundamento: Los mecanismos que desencadenan la osteogénesis todavía no están aclarados. El objetivo de este estudio fue valorar el papel de estroncio y calcio, aportados en distinto soporte molecular, como inductores de distintos mecanismos de estímulo osteoblástico, incluyendo proliferación, diferenciación y mineralización de células preosteoblásticas. Se investigó también la respuesta global genómica con la técnica de microarray. Métodos: Se diseñó un estudio experimental con células pre-osteoblásticas murinas MC3T3-E1, que fueron estimuladas durante 3 horas y 7 días. Se realizaron estudios bioquímicos y de expresión génica del genoma de ratón (Affymetrix). Resultados: El estroncio unido …
3D virtual histopathology of cardiac tissue from Covid-19 patients based on phase-contrast X-ray tomography
2021
eLife 10, e71359 (2021). doi:10.7554/eLife.71359
Measurements of the volume and density of intracerebral tumors by CT following therapy.
1982
For the interpretation of curative measures in patients with cerebral tumors CT is of increasing importance. The therapeutic effects can be demonstrated by close follow-up studies without any of the disadvantage of invasive neuroradiological methods. Our investigations of 125 patients with cerebral tumors are based on volume and density determinations. The CT studies of removed or inoperable tumors followed by radiation and/or cytostatic therapy prove that the best results follow a combination of both. In the present cases however, if CT proves postoperatively, at the end of radiation or at the beginning of the application of cytostatics that there is a residual mass, a complete remission c…
Technique and value of gas and pantopaque cisternography in the diagnosis of cerebello-pontine angle tumours
1971
The techniques of gas and Pantopaque cisternography are described, as well as the various advantages and disadventages of these methods. Patients without neurological signs in whom a small tumour is suspected in the region of the cerebellopontine angle should be examined with Pantopaque. The examination can be carried out as an outpatient procedure. If definite neurological signs are present, gas cisternography is preferable in order to demonstrate secondary displacements of the ventricular system as well as the tumour itself.