Search results for " video"
showing 10 items of 324 documents
Cardiac kinematic parameters computed from video of in situ beating heart
2017
AbstractMechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial veloc…
Disturbance of hepatic and intestinal microcirculation in experimental liver cirrhosis
2005
AIM: To analyze hepatic, mesenteric and mucosal microcirculation and leukocyte-endothelium interaction (LEI) in a rat model with liver cirrhosis. METHODS: Hepatic cirrhosis was induced in Wistar rats by gavage with carbon tetrachloride, and intravital videomicroscopy was performed in liver, mesentery and small intestine mucosa. Special emphasis is given on microcirculatory and morphometric changes during cirrhotic portal hypertension. RESULTS: LEI was influenced significantly in the cirrhotic liver but not in the gut. Blood flow measurement showed significant differences among liver, main mesenteric vessels and the mucosa. The results of our study indicate that liver cirrhosis leads to alte…
Video-thoracoscopic surgical pleurodesis in the management of malignant pleural effusion: the importance of an early intervention.
2005
Thoracentesis plays an important role in cancer patients with symptomatic effusions, although its effect is short-lived and symptoms recur in almost all patients. Early video-thoracoscopic surgical pleurodesis may provide added benefit to a group of patients with advanced cancer presenting with symptomatic malignant pleural effusion. Seventy-six patients with advanced cancer and pleural effusion due to pulmonary-pleural metastases were recruited. In 51 cases (67.1%), at least one thoracentesis was performed before admission for surgery. Preoperative staging consisted of chest radiograph, CT scan, and blood gas analysis. The mean Karnofsky performance status was about 50. Pleurodesis with ta…
Capillary flow and diameter changes during reperfusion after global cerebral ischemia studied by intravital video microscopy.
2004
The reaction of cerebral capillaries to ischemia is unclear. Based on Hossmann's observation of postischemic “delayed hypoperfusion,” we hypothesized that capillary flow is decreased during reperfusion because of increased precapillary flow resistance. To test this hypothesis, we measured cerebral capillary erythrocyte velocity and diameter changes by intravital microscopy in gerbils. A cranial window was prepared over the frontoparietal cortex in 26 gerbils anesthetized with halothane. The animals underwent either a sham operation or fifteen minutes of bilateral carotid artery occlusion causing global cerebral ischemia. Capillary flow velocities were measured by frame-to-frame tracking of…
Gastric antisecretory drugs induce leukocyte-endothelial cell interactions through gastrin release and activation of CCK-2 receptors.
2007
Antisecretory drugs are effective antiulcer agents, but its chronic use generates hypergastrinemia and accelerates the development of atrophic gastritis in Helicobacter pylori-positive patients. We have recently shown that gastrin exerts a proinflammatory effect in rats through CCK-2 receptor activation that contributes to the inflammation induced by H. pylori. The present study was designed to examine whether gastrin hypersecretion in response to treatment with antisecretory drugs induces an inflammatory response that could promote mucosal atrophy. The effects of omeprazole or famotidine on leukocyte/endothelial cell interactions in vivo were analyzed in rat mesenteric venules using intrav…
"In vivo" evaluation of the vascular pattern in oral peri-implant tissues.
2011
Abstract Introduction The vascularisation of the peri-implant tissue represents the key factor in obtaining a successful result in implantology, since an adequate vascular supply allows wound healing and the presence of numerous growth factors that promote osteogenesis. The aim of this study was to analyse “in vivo” the vascular pattern of the peri-implant mucosa in subjects that received implant treatment. Materials and methods In the study 22 subjects were examined, 11 of whom (test group) received dental implants (Straumann Dental Implant System ® ) while 11 were in the control group; the analysis was performed in the peri-implant masticatory mucosa. The evaluation of the microcirculatio…
A block access unit for 2D memory access
2007
Many of the coding tools in the H.264/AVC video coding standard are based on 2D processing resulting in rowwise and column-wise memory accesses starting from arbitrary memory addresses. This paper discusses a low-cost hardware realization of these accesses on sub-word parallel processors. The proposed block access unit is placed between the processor and memory. It supports unaligned 2D block accesses according to several 2D access patterns. The 2D block accesses are pipelinable and they result in minimum number of memory accesses required to deliver the desired data.
On the Provisioning of Mobile Digital Terrestrial TV Services to Vehicles With DVB-T
2012
[EN] Most of the DVB-T (Digital Video Broadcasting -Terrestrial) networks deployments worldwide have been designed for fixed rooftop antennas and high transmission capacity, not providing good coverage level for vehicular mobile reception. This letter analyzes how to combine different technical solutions, so far studied individually, in order to increase the robustness of the transmission for vehicular reception to provide in-band mobile services. In particular, we consider: receive antenna diversity, hierarchical modulation, and Application Layer Forward Error Correction (AL-FEC). Performance evaluation results have been obtained by means of simulations, laboratory tests, and field measure…
Eficacia de las técnicas de control de la impulsividad en la prevención de la adicción a videojuegos
2017
The main objective of this research has been the analysis of the effectiveness of some impulsivity control techniques to prevent videogame addiction. It has compared the results obtained with a prevention program that it had been already validated with the same program in which additional impulsiveness control techniques were added. Four periods were selected for the analysis: baseline, pre-test, post-test and follow-up. Two experimental conditions were designed: a) conventional prevention program, and b) program with impulsiveness control techniques. Results were compared with a group control (waiting list). Results indicate that, while groups that remain on waiting list do not present cha…
Using Internet videos to learn about controversies: Evaluation and integration of multiple and multimodal documents by primary school students
2020
Abstract In many Internet videos authors appear in front of the camera to present their particular view on a topic. Given the high consumption rate of Internet videos by teenagers, we explored the pros and cons of using these videos to learn about complex topics, compared to learning from textual web pages. Specifically, we studied how 207 primary school students (grades 4–6) evaluated and integrated multiple and multimodal web pages (text or video) while learning about the pros and cons of bottled water. Results showed no major role of modality in students' source memory, as measured by citations in their responses to an integration question and their memory for sources. Nevertheless, moda…