Increasing the Contribution of GFRP Bars on the Compressive Strength of Concrete Columns with Circular Cross Section

Corrosion of steel in concrete elements is a major issue in concrete structures. In order to overcome this matter, Glass Fiber Reinforced Polymer (GFRP) reinforcement is being used in concrete members from almost 20 years ago. Although it has been used and developed in recent years, there are still some uncertainties for the application of FRP reinforcement, especially in concrete columns.  Most codes such as ACI, CSA, JSCE & etc. neglects the effect of these reinforcements or they do not permit them in compressive concrete elements. In this essay, it has been shown that these rebar can contribute significantly in compressive strength of concrete columns if the column confinement is provided sufficiently. In order to achieve the required confinement to reach a sharp contribution of GFRP longitudinal rebar in concrete columns, the spiral of FRP rebar with small pitches around longitudinal rebar is taken into account. This leads to higher strains of concrete which can result in a higher contribution of FRP longitudinal rebar. Foremost, equations related to the compressive strength of concrete columns considering the influence of spiral confinement will be carried out. Then, a parametric study will be performed, and the effects of pitch, concrete strength, column diameter, the quantity of longitudinal rebar and concrete cover will be investigated

Radiation Dose Reduction in the Cardiac Catheterization Laboratory Utilizing a Novel Protocol

ObjectivesThis study reports the results a novel radiation reduction protocol (RRP) system for coronary angiography and interventional procedures and the determinants of radiation dose.BackgroundThe cardiac catheterization laboratory is an important source of radiation and should be kept in good working order with dose-reduction and monitoring capabilities.MethodsAll diagnostic coronary angiograms and percutaneous coronary interventions from a single catheterization laboratory were analyzed 2 months before and after RRP implementation. The primary outcome was the relative dose reduction at the interventional reference point. Separate analyses were done for conventional 15 frames/s (FPS) and at reduced 7.5 FPS post-RRP groups.ResultsA total of 605 patients underwent coronary angiography (309 before RRP and 296 after RRP), with 129 (42%) and 122 (41%) undergoing percutaneous coronary interventions before and after RRP, respectively. With RRP, a 48% dose reduction (1.07 ± 0.05 Gy vs. 0.56 ± 0.03 Gy, p < 0.0001) was obtained, 35% with 15 FPS RRP (0.70 ± 0.05 Gy, p < 0.0001) and 62% with 7.5 FPS RRP (0.41 ± 0.03 Gy, p < 0.001). Similar dose reductions for diagnostic angiograms and percutaneous coronary interventions were noted. There was no change in the number of stents placed or vessels intervened on. Increased dose was associated with male sex, radial approach, increasing body mass index, cine runs, and frame rates. Using a multivariable model, a 48% relative risk with RRP (p < 0.001), 44% with 15 FPS RRP and 68% with 7.5 FPS RRP was obtained.ConclusionsWe demonstrate a highly significant 48.5% adjusted radiation dose reduction using a novel algorithm, which needs strong consideration among interventional cardiology practice

Renal Insufficiency and Early Bystander CPR Predict In-Hospital Outcomes in Cardiac Arrest Patients Undergoing Mild Therapeutic Hypothermia and Cardiac Catheterization: Return of Spontaneous Circulation, Cooling, and Catheterization Registry (ROSCCC Registry)

Objective. Out of hospital cardiac arrest (OHCA) patients are a critically ill patient population with high mortality. Combining mild therapeutic hypothermia (MTH) with early coronary intervention may improve outcomes in this population. The aim of this study was to evaluate predictors of mortality in OHCA patients undergoing MTH with and without cardiac catheterization. Design. A retrospective cohort of OHCA patients who underwent MTH with catheterization (MTH + C) and without catheterization (MTH + NC) between 2006 and 2011 was analyzed at a single tertiary care centre. Predictors of in-hospital mortality and neurologic outcome were determined. Results. The study population included 176 patients who underwent MTH for OHCA. A total of 66 patients underwent cardiac catheterization (MTH + C) and 110 patients did not undergo cardiac catheterization (MTH + NC). Immediate bystander CPR occurred in approximately half of the total population. In the MTH + C and MTH + NC groups, the in-hospital mortality was 48% and 78%, respectively. The only independent predictor of in-hospital mortality for patients with MTH + C, after multivariate analysis, was baseline renal insufficiency (OR = 8.2, 95% CI 1.8–47.1, and p = 0.009). Conclusion. Despite early cardiac catheterization, renal insufficiency and the absence of immediate CPR are potent predictors of death and poor neurologic outcome in patients with OHCA

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.This work was supported by the CancerCare Manitoba Operating grant (763117252) funded by CancerCare Manitoba Foundation, a Vanier CIHR Ph.D. studentship, and the Max Rady College of Medicine’s BSc (Med) program

Isolation and characterization of low-density lipoprotein lipid glycation products

grantor: University of TorontoOne of the pathological consequences of diabetes due to hyperglycemia is the nonenzymatic glycation of free amino groups by glucose. Not only proteins and nucleic acids participate in this reaction but aminophospholipids also under go glycation. This thesis describes the isolation and characterization of the products of the reaction between glucose and amino phospholipids 'in vitro' and 'in vivo' sources and their possible pathogenic effects. The major glycation products described here are the products of phosphatidylethanolamine (PtdEtn) and phosphatidylserine (PtdSer) with glucose which were identified by liquid chromatography with online electrospray mass spectrometry (LC/MS). The major product of the reaction was the glucosylated aminophospholipid which on the normal phase HPLC was resolved from the non glucosylated phospholipid. The glucosylated PtdEtn (Glc PtdEtn) and PtdSer (Glc PtdSer) were also identified in Red Blood Cells (RBC) incubated with various glucose concentrations. The pattern of glycation of the RBC aminophospholipids showed that the glycation reaction did not have any preference for specific molecular species or aminophospholipid class. Glycated PtdEtn was also identified in both plasma and RBC of control and diabetic individuals. There was a 10-fold increase in the amount of glycated PtdEtn in diabetic subjects when compared to the controls. Glycated PtdEtn was identified 'in vitro' preparations of LDL in presence of various glucose concentrations. LDL PtdEtn glucosylation was concentration dependent and both diacyl and plasmalogenic species were glucosylated. The glycated PtdEtn when present in liposomal preparation showed an increased susceptibility to oxidation. Glc-PtdEtn also resulted in an increased oxidative susceptibility of other phospholipids, such as phosphatidylcholine (PtdCho), when present in the liposomal mixture. This susceptibility was also observed for LDL specifically enriched in Glc-PtdEtn in presence of copper ions. As a result of Glc PtdEtn both LDL PtdCho hydroperoxides and PtdCho core aldehydes had 4 fold increase compared to control LDL during copper oxidation. Finally, it was established that Glc-PtdEtn present in LDL can result in increased LDL uptake by macrophages resulting in cholesteryl ester and triacylglycerol deposition in THP-1 macrophages. The results indicate that glucosylation of PtdEtn in LDL accounts for the entire effect of LDL glycation on macrophage uptake, and therefore the increased atherogenic potential of LDL in hyperglycemia.Ph.D

Lipidomics of Bioactive Lipids in Acute Coronary Syndromes

Acute coronary syndrome (ACS) refers to ischemic conditions that occur as a result of atherosclerotic plaque rupture and thrombus formation. It has been shown that lipid peroxidation may cause plaque instability by inducing inflammation, apoptosis, and neovascularization. There is some evidence showing that these oxidized lipids may have a prognostic value in ACS. For instance, higher levels of oxidized phospholipids on apo B-100 lipoproteins (OxPL/apoB) predicted cardiovascular events independent of traditional risk factors, C-reactive protein (hsCRP), and the Framingham Risk Score (FRS). A recent cross-sectional study showed that levels of oxylipins, namely 8,9-DiHETrE and 16-HETE, were significantly associated with cardiovascular and cerebrovascular events, respectively. They found that with every 1 nmol/L increase in the concentrations of 8,9-DiHETrE, the odds of ACS increased by 454-fold. As lipid peroxidation makes heterogonous pools of secondary products, therefore, rapid multi-analyte quantification methods are needed for their assessment. Conventional lipid assessment methods such as chemical reagents or immunoassays lack specificity and sensitivity. Lipidomics may provide another layer of a detailed molecular level to lipid assessment, which may eventually lead to exploring novel biomarkers and/or new treatment options. Here, we will briefly review the lipidomics of bioactive lipids in ACS