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Protective System (protective + system)
Selected AbstractsFeasibility and Safety of Using an Esophageal Protective System to Eliminate Esophageal Thermal Injury: Implications on Atrial-Esophageal Fistula Following AF AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2009MAURICIO S. ARRUDA M.D. Background: Ablation for atrial fibrillation (AF) requires energy delivery in close proximity to the esophagus (Eso) which has accounted for the LA-Eso fistula, a rare but life-threatening complication. Purpose: We evaluated an Eso cooling system to protect the Eso during RF ablation. Methods and Results: An "in vitro" heart-Eso preparation was initially used to test a temperature-controlled fluid-circulating system (EPSac [esophageal protective system],RossHart Technologies Inc.) and an expandable compliant Eso sac during cardiac RF delivery (4 mm tip, perpendicular to the heart, 15 g pressure) at 25, 35, and 45 W, 100 ± 5 , for 30 seconds with the EPSac at 25, 15, 10, and 5°C. All cardiac lesions were transmural. Eso thermal injury could only be avoided with the EPSac at 10 and 5°C. The system was then tested in 6 closed chest dogs, each receiving 12 RFs (LA aiming at the Eso) for 30 seconds: without EPSac (control) at 35 W (1 dog); at 45 W with EPSac at 25°C (1 dog), 10°C (2 dogs), and 5°C (2 dogs). The EPSac volume was intentionally increased to displace the Eso toward the LA (2 dogs 5 and 10°C). Eso injured control and EPSac at 25°C; Eso spared EPSac at 5 and 10°C, without Eso displacement. Shallow external Eso injury noted when intentionally displacing the Eso toward the LA. Conclusions: The EPSac spares the Eso from collateral thermal injury. It requires circulating fluid at 5 or 10°C and a compliant sac to avoid displacement of the Eso. Its safety and efficacy remain to be demonstrated in patients undergoing AF ablation. [source] Protective Systems for High Temperature Applications: From Theory to Industrial ImplementationMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2008Michael Schütze [source] Surface-Modified Mesoporous SiO2 Containers for Corrosion ProtectionADVANCED FUNCTIONAL MATERIALS, Issue 15 2009Ekaterina V. Skorb Abstract The development of active corrosion protection systems for metallic substrates is an issue of prime importance for many industrial applications. The present work shows a new contribution to the design of a new protective system based on surface modified mesoporous silica containers. Incorporation of silica-based containers into special sol,gel matrix allows for a self-healing effect to be achieved during the corrosion process. The self-healing ability occurs due to release of entrapped corrosion inhibitors in response to pH changes caused by the corrosion process. A silica,zirconia-based hybrid film is used in this work as a coating matrix deposited on AA2024 aluminum alloy. Mesoporous silica nano-particles are covered layer-by-layer with polyelectrolyte layers and loaded with inhibitor [2-(benzothiazol-2-ylsulfanyl)-succinic acid]. The hybrid film with nanocontainers reveals enhanced long-term corrosion protection in comparison with the individual sol,gel films. The scanning vibrating electrode technique also shows an effective healing ability of containers to cure the corrosion defects. This effect is due to the release of the corrosion inhibitor triggered by the corrosion processes started in the cavities. The approach described herein can be used in many applications where active corrosion protection of materials is required. [source] Impaired efflux of cholesterol from aged cells and its molecular mechanism: A basis for age-related enhancement of atherosclerosisGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2007Shizuya Yamashita Aging is one of the risk factors for atherosclerotic cardiovascular diseases, however, its molecular mechanism is currently unknown. Many types of cells in the atherosclerotic lesions are considered to have various biological abnormalities such as impaired lipid homeostasis and slow cell proliferation, which may be related to senescence at cellular levels. One of the common characteristics of senescent cells in vitro is the alteration of actin cytoskeletons, which were reported to be involved in the intracellular transport of lipids. Cholesterol efflux from the cells is the initial step of reverse cholesterol transport, a major protective system against atherosclerosis. Recently, we demonstrated that Cdc42, a member of the Rho -GTPase family, might be crucial for cellular lipid transport and cholesterol efflux based upon studies of Tangier cells that are deficient in ABCA1 gene. In the current review, we also indicate that the expression of Cdc42 is decreased in the cells from aged subjects in close association with the retarded intracellular lipid transport. Furthermore, the Cdc42 expression is reduced by culturing fibroblasts in vitro for a long duration. Werner syndrome (WS) is characterized by the early onset of senescent phenotypes including premature atherosclerotic cardiovascular diseases, although the underlying molecular mechanism for the enhanced atherosclerosis has not been fully understood yet. We examined the intracellular lipid transport and cholesterol efflux and the expression levels of cholesterol efflux-related molecules in skin fibroblasts obtained from patients with WS. Cholesterol efflux was markedly reduced in the WS fibroblasts in association with an increased cellular cholesterol content. Fluorescent recovery after photobleaching technique revealed that intracellular lipid transport around Golgi apparatus was markedly reduced when using a C6-NBD-ceramide as a tracer. Cdc42 protein and its guanosine 5,-triphosphate-bound active form were markedly reduced in the WS fibroblasts. The adenovirus-mediated complementation of wild-type Cdc42 corrected the impaired cholesterol efflux, intracellular lipid transport and cellular cholesterol levels in the WS fibroblasts. These data indicate that the reduced expression of Cdc42 might be responsible for the abnormal lipid transport, which in turn might be related to the accelerated cardiovascular manifestations in WS patients. The current review focuses on the impaired efflux of cholesterol from aged cells and its molecular mechanism as a basis for age-related enhancement of atherosclerosis. [source] Feasibility and Safety of Using an Esophageal Protective System to Eliminate Esophageal Thermal Injury: Implications on Atrial-Esophageal Fistula Following AF AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2009MAURICIO S. ARRUDA M.D. Background: Ablation for atrial fibrillation (AF) requires energy delivery in close proximity to the esophagus (Eso) which has accounted for the LA-Eso fistula, a rare but life-threatening complication. Purpose: We evaluated an Eso cooling system to protect the Eso during RF ablation. Methods and Results: An "in vitro" heart-Eso preparation was initially used to test a temperature-controlled fluid-circulating system (EPSac [esophageal protective system],RossHart Technologies Inc.) and an expandable compliant Eso sac during cardiac RF delivery (4 mm tip, perpendicular to the heart, 15 g pressure) at 25, 35, and 45 W, 100 ± 5 , for 30 seconds with the EPSac at 25, 15, 10, and 5°C. All cardiac lesions were transmural. Eso thermal injury could only be avoided with the EPSac at 10 and 5°C. The system was then tested in 6 closed chest dogs, each receiving 12 RFs (LA aiming at the Eso) for 30 seconds: without EPSac (control) at 35 W (1 dog); at 45 W with EPSac at 25°C (1 dog), 10°C (2 dogs), and 5°C (2 dogs). The EPSac volume was intentionally increased to displace the Eso toward the LA (2 dogs 5 and 10°C). Eso injured control and EPSac at 25°C; Eso spared EPSac at 5 and 10°C, without Eso displacement. Shallow external Eso injury noted when intentionally displacing the Eso toward the LA. Conclusions: The EPSac spares the Eso from collateral thermal injury. It requires circulating fluid at 5 or 10°C and a compliant sac to avoid displacement of the Eso. Its safety and efficacy remain to be demonstrated in patients undergoing AF ablation. [source] VENOUS NEEDLE DISLODGEMENT: HOW TO MINIMISE THE RISKSJOURNAL OF RENAL CARE, Issue 4 2008Jean-Pierre Van Waeleghem SUMMARY Although haemodialysis (HD) has become a routine treatment, adverse side effects, and occasionally life threatening clinical complications, still happen. Venous needle dislodgment (VND) is one of the most serious accidents that can occur during HD. If the blood pump is not stopped, either by activation of the protective system of the dialysis machine or manually, the patient can bleed to death within minutes. Fatal and near-fatal blood loss due to VND have been described in the literature (ECRI 1998; Sandroni 2005; Mactier & Worth 2007), but published reports represent only the tip of the ice berg, as such incidents are normally handled at a local or national level. The European Dialysis and Transplant Nurses Association/European Renal Care Association (EDTNA/ERCA) has produced 12 practice recommendations to help reduce the risk of VND and detect blood leakage as early as possible. A poster summarising these recommendations has been created (Van Waeleghem et al. 2008). [source] Downregulation of oxytocin and natriuretic peptides in diabetes: possible implications in cardiomyopathyTHE JOURNAL OF PHYSIOLOGY, Issue 19 2009Jolanta Gutkowska Regular physical activity is beneficial in preventing the risk of cardiovascular complications of diabetes. Recent studies showed a cardioprotective role of oxytocin (OT) to induce natriuretic peptides (NPs) and nitric oxide (NO) release. It is not known if the diabetic state is associated with a reduced OT,NPs,NO system and if exercise training improves this system. To address this, we investigated the effects of treadmill running using the db/db mouse model of type 2 diabetes. Eight-week-old db/db mice were subjected to running 5 days per week for a period of 8 weeks. The lean db/+ littermates were used as controls. Sedentary db/db mice were obese and hyperglycaemic, and exercise training was not effective in reducing body weight and the hyperglycaemic state. Compared to control mice, db/db mice had lower heart weight and heart-to-body weight ratios. In these mice, this was associated with augmented cardiac apoptosis, cardiomyocyte enlargement and collagen deposits. In addition, db/db mice displayed significant downregulation in gene expression of OT (76%), OT receptors (65%), atrial NP (ANP; 43%), brain NP (BNP; 87%) and endothelial nitric oxide synthase (eNOS) (54%) in the heart (P < 0.05). Exercise training had no effect on expression of these genes which were stimulated in control mice. In response to exercise training, the significant increment of anti-apoptotic Bcl-2 gene expression was observed only in control mice (P < 0.05). In conclusion, downregulation of the OT,NPs,NO system occurs in the heart of the young db/db mouse. Exercise training was not effective in reversing the defect, suggesting impairment of this cardiac protective system in diabetes. [source] Reliability evaluation of transmission network including effect of protection systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 8 2008A.-R. Alesaadi Abstract Transmission network reliability evaluation considering effects of protective systems is investigated in this paper. Protective system faults are one of the main sources of cascading outages and may lead to vast blackouts. Desired performance of the protection system has a significant role in the improvement of network reliability. The proposed method is based on minimal cutset approach. In the proposed method, all elements of the transmission and subtransmission substations can be considered in which subtransmission substations are taken as output nodes. A sensitivity analysis of network reliability to component reliability parameters is performed. Finally the effectiveness of the method was tested in a real network with satisfactory results. Copyright © 2007 John Wiley & Sons, Ltd. [source] An overview of inherently safer design,PROCESS SAFETY PROGRESS, Issue 2 2006Dennis C. Hendershot Inherently safer product and process design represents a fundamentally different approach to safety in the manufacture and use of chemicals. The designer is challenged to identify ways to eliminate or significantly reduce hazards, rather than to develop add-on protective systems and procedures. In the chemical process industries, risk management layers of protection are classified as inherent, passive, active, and procedural. Inherently safer design focuses on eliminating hazards, or minimizing them significantly, to reduce the potential consequence to people, the environment, property, and business. Inherently safer design is considered to be the most robust way of dealing with process risk and can be considered to be a subset of green chemistry and green engineering. It focuses on safety hazards,the immediate impacts of single events such as fires, explosions, and short-term toxic impacts. Many of the strategies of inherently safer design are not specific to the chemical industry, but apply to a broad range of technologies. Strategies for identifying inherently safer options are discussed, with examples. However, for most facilities, a complete risk management program will include features from all categories of layers of protection. Also, the designer must be aware that all processes and materials have multiple hazards and that there can be conflicts among the risks associated with different alternatives. Design alternatives that reduce or eliminate one hazard may create or increase the magnitude of others. Recognition and understanding of these conflicts will enable the designer to make intelligent decisions to optimize the design. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source] | |||||||||||||