Search results for " vessels"
showing 10 items of 303 documents
Vortex shape in unbaffled stirred vessels: experimental study via digital image analysis
2011
There is a growing interest in using unbaffled stirred tanks for addressing certain processing needs. In this work, digital image analysis coupled with a suitable shadowgraphy-based technique is used to investigate the shape of the free-surface vortex that forms in uncovered unbaffled stirred tanks. The technique is based on back-lighting the vessel and suitably averaging vortex shape over time. Impeller clearance from vessel bottom and tank filling level are varied to investigate their influence on vortex shape. A correlation is finally proposed to fully describe vortex shape also when the vortex encompasses the impeller.
Damage accumulation and life prediction in carbon fibre composite pressure vessels
2009
Composites and nanostructures
Recent advances in understanding the lymphatic and glymphatic systems of the brain
2015
This review summarises current knowledge on the lymphatic system of the brain. It has long been believed that the central nervous system is characterised by the lack of a lymphatic system and that the role of the lymphatic system is played by cerebrospinal fluid. Recently, research has shown that not only is the brain equipped with its own unique lymphatic system, but also that this system consists of two anatomically and functionally distinct parts. One part of this system is a classic lymphatic system, i.e. the structure composed of genuine lymphatic vessels. The other, so-called glymphatic system, is primarily built by astrocytes. The newly discovered lymphatic system of the brain is lik…
Metabolic syndrome therapy: Prevention of vascular injury by antidiabetic agents
2005
More than 65 million Americans are currently obese. Type 2 diabetes mellitus, frequently seen in obese subjects, affects 17 million adults in the United States, with a continuous and alarmingly increasing rate. To prevent development of diabetes in those who are at high risk, it is recommended to optimize meal planning and enhance physical activity to make sustained weight reduction possible. In addition to lifestyle changes, various oral antidiabetic agents are available, with diverse mechanisms of action. Some target defective insulin secretion (sulphonylureas, benzoic acid derivatives) or glucose absorption (glycosidase inhibitors), whereas others target insulin resistance (metformin, th…
Decidual endothelial cells express surface-bound C1q as a molecular bridge between endovascular trophoblast and decidual endothelium.
2008
This study was prompted by the observation that decidual endothelial cells (DECs), unlike endothelial cells (ECs) of blood vessels in normal skin, kidney glomeruli and brain, express surface-bound C1q in physiologic pregnancy. This finding was unexpected, because deposits of C1q are usually observed in pathologic conditions and are associated with complement activation. In the case of DECs, we failed to detect immunoglobulins and C4 co-localized with C1q on the cell surface. Surprisingly, DECs expressed mRNA for the three chains of C1q and secreted detectable level of this component in serum-free medium. The ability to synthesize C1q is acquired by DECs during pregnancy and is not shared by…
Color Doppler imaging of the eye and orbit A synopsis of a 400 case experience
2009
Color Doppler imaging (CDI) is a recent advance in ultrasonography that allows simultaneous two-dimensional imaging of structure and blood flow. Doppler information is superimposed in color over a conventional gray-scale ultrasound image. Using this technique we have examined 400 eyes. The central retinal artery, posterior ciliary arteries, ophthalmic artery, the central retinal vein and the vortex veins could be located in all normal eyes. Using the color image as a guide, Doppler spectral analysis is used for quantitative assessment of blood flow velocity in these vessels. We also studied patients with intraocular tumors, arterial and venous retinal occlusions, orbital vascular anomalies …
Management of Coronary Artery Perforation
2020
Coronary artery perforation (CAP) is a rare but potentially life-threatening complication of percutaneous coronary intervention (PCI), however if recognized and managed promptly, its adverse consequences can be minimized. Risk factors for CAP include the use of advanced PCI technique (such as atherectomy and chronic total occlusion interventions) and treatment of severely calcified lesions. There are 3 major types of CAP depending on location: (a) large vessel perforation, (b) distal vessel perforation, and (c) collateral perforation. Large vessel perforation is usually treated with implantation of a covered stent, whereas distal and collateral vessel perforations are usually treated with c…
Current status on the adoption of high energy devices in Italy. An Italian Society for Endoscopic Surgery and New Technologies (SICE) national survey
2021
Background: In the past three decades, different High Energy Devices (HED) have been introduced in surgical practice to improve the efficiency of surgical procedures. HED allow vessel sealing, coagulation and transection as well as an efficient tissue dissection. This survey was designed to verify the current status on the adoption of HED in Italy. Methods: A survey was conducted across Italian general surgery units. The questionnaire was composed of three sections (general information, elective surgery, emergency surgery) including 44 questions. Only one member per each surgery unit was allowed to complete the questionnaire. For elective procedures, the survey included questions on thyroid…
Mechanisms of hypertension in the cardiometabolic syndrome
2009
Arterial hypertension is often part of a constellation of anthropometric and metabolic abnormalities that occur simultaneously to a higher degree than would be expected by chance alone, supporting the existence of a discrete disorder, the so-called metabolic syndrome. It is the result of interactions among a large number of interconnected mechanisms, which eventually lead to both an increase in cardiovascular and renal risk, and the development of diabetes. Mechanisms involved in the metabolic syndrome are obesity, insulin resistance, and a constellation of independent factors, which include molecules of hepatic, vascular, and immunologic origin with pro-inflammatory properties. At each of …
Discrimination of early/intermediate and advanced/complicated coronary plaque types by radiofrequency intravascular ultrasound analysis
2002
Radiofrequency intravascular ultrasound (IVUS-RF) analysis, as an extension of conventional IVUS imaging, may provide more accurate plaque discrimination. Thirty-two autopsy atherosclerotic coronary arteries were investigated. Corresponding sectors in different plaques were matched by histologic and RF analysis. Histologic analysis utilized the American Heart Association plaque classification. The backscattered ultrasound RF signal was analyzed by fast-Fourier transform, providing the underlying frequency components of its power spectrum. The normalized backscattered signal power (in decibels [dB]) for frequencies between 15.3 and 40.3 MHz was then measured for plaque discrimination. Advanc…