232 research outputs found
RESEARCH NOTE: permeability control on the relationship between nuclear magnetic resonance (NMR) measured porosity and routine core porosity
Palliative Combined Percutaneous Balloon Aortic Valvuloplasty and Unprotected Left Main Stenting in End Stage Renal Disease
With the aging population and high prevalence of atherosclerosis, an increasing number of patients presenting with heart failure and angina are found to have severe coronary artery disease and severe valvular disease. These patients tend to have multiple co-morbidities such as end stage renal disease and are considered high-risk for surgery. In patients with severe coronary artery disease, severe aortic stenosis, and heart failure with depressed left ventricular systolic function, the options are limited as they are not usually offered surgery, but palliative percutaneous high-risk procedures might be a viable alternative
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Loss Analysis in Radial Inflow Turbines for Supercritical CO2 Mixtures
Recent studies suggest that CO2 mixtures can reduce the costs of concentrated solar power plants. Radial inflow turbines (RIT) are considered suitable for small to medium-sized CO2 power plants (100 kW to 10 MW) due to aerodynamic and cost factors. This paper quantifies the impact of CO2 doping on RIT design by comparing 1D mean-line designs and aerodynamic losses of pure CO2 RITs with three CO2 mixtures: titanium tetrachloride (TiCl4), sulfur dioxide (SO2), and hexafluorobenzene (C6F6). Results show that turbine designs share similar rotor shapes and velocity diagrams for all working fluids. However, factors like clearance-to-blade height ratio, turbine pressure ratio, and fluid viscosity cause differences in turbine efficiency. When normalized for these factors, differences in total-to-static efficiency become less than 0.1%. However, imposing rotational speed limits reveals greater differences in turbine designs and efficiencies. The imposition of rotational speed limits reduces total-to-static efficiency across all fluids, with a maximum 15% reduction in 0.1 MW CO2 compared to a 3% reduction in CO2/TiCl4 turbines of the same power. Among the studied mixtures, CO2/TiCl4 turbines achieve the highest efficiency, followed by CO2/C6F6 and CO2/SO2. For example, 100 kW turbines achieve total-to-static efficiencies of 80.0%, 77.4%, 78.1%, and 75.5% for CO2/TiCl4, CO2/C6F6, CO2/SO2, and pure CO2, respectively. In 10 MW turbines, efficiencies are 87.8%, 87.3%, 87.5%, and 87.2% in the same order
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Loss Analysis in Radial Inflow Turbines for Supercritical CO2 Mixtures
Data Availability Statement: The datasets generated and supporting the findings of this article are obtainable from the corresponding author upon reasonable request.Paper No: TURBO-23-1236Recent studies suggest that CO2 mixtures can reduce the costs of concentrated solar power plants. Radial inflow turbines (RIT) are considered suitable for small to medium-sized CO2 power plants (100 kW to 10 MW) due to aerodynamic and cost factors. This paper quantifies the impact of CO2 doping on RIT design by comparing 1D mean-line designs and aerodynamic losses of pure CO2 RITs with three CO2 mixtures: titanium tetrachloride (TiCl4), sulfur dioxide (SO2), and hexafluorobenzene (C6F6). Results show that turbine designs share similar rotor shapes and velocity diagrams for all working fluids. However, factors like clearance-to-blade height ratio, turbine pressure ratio, and fluid viscosity cause differences in turbine efficiency. When normalized for these factors, differences in total-to-static efficiency become less than 0.1%. However, imposing rotational speed limits reveals greater differences in turbine designs and efficiencies. The imposition of rotational speed limits reduces total-to-static efficiency across all fluids, with a maximum 15% reduction in 0.1 MW CO2 compared to a 3% reduction in CO2/TiCl4 turbines of the same power. Among the studied mixtures, CO2/TiCl4 turbines achieve the highest efficiency, followed by CO2/C6F6 and CO2/SO2. For example, 100 kW turbines achieve total-to-static efficiencies of 80.0%, 77.4%, 78.1%, and 75.5% for CO2/TiCl4, CO2/C6F6, CO2/SO2, and pure CO2, respectively. In 10 MW turbines, efficiencies are 87.8%, 87.3%, 87.5%, and 87.2% in the same order.European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 814985
Loss of p53 Expression in Gastric Epithelial Cells of Helicobacter pylori-Infected Jordanian Patients
BACKGROUND: Around half of the global population is chronically infected with the stomach bacterium Helicobacter pylori, making it one of the most common chronic infections worldwide. H. pylori induces the production of reactive oxygen species, DNA damage, and accelerates the degradation of the tumor suppressor protein p53, which may lead to cancer development. In this study, we investigated the relationship between H. pylori infection and the expression of p53 in gastric mucosa in a group of patients from Jordan. METHODS: In this retrospective case-control study, the epithelium of gastric glands in subjects chronically infected with H. pylori was examined for the expression of p53. Paraffin-embedded gastric biopsy samples from the archives for 50 Jordanian patients diagnosed with chronic H. pylori infection and 25 samples free of H. pylori infection and any other gastric abnormalities were selected. Samples were analyzed for the presence of H. pylori as well as p53 expression levels in the mucosa and submucosa by immunohistochemical analyses and Western blotting. RESULTS: H. pylori was detected in the gastric tissues of infected individuals (n = 50); whereas, no H. pylori infection was detected in uninfected healthy individuals (n = 25) using immunohistochemistry. In contrast to the noninfected samples of gastric mucosa, no nuclear p53 expression was detected in the infected samples using immunohistochemistry. In addition, the levels of p53 in H. pylori-positive samples detected by Western blotting were significantly lower than those in the negative individuals. CONCLUSION: Our data reveal that p53 protein expression decreased in gastric mucosa of patients infected with H. pylori. The loss of this tumor suppressor may play a role in the increased risk for tumor initiation associated with H. pylori carriage
Hypertrophic obstructive cardiomyopathy in liver transplant patients
The optimal treatment strategy for patients with symptomatic hypertrophic obstructive cardiomyopathy
(HOCM) and end-stage liver disease (ESLD) is not well defined. Although medical
management is the accepted first line treatment, patients who are unresponsive to medication
require further interventions. Since ESLD patients have a high operative risk for surgical
myomectomy, alcohol septal ablation (ASA) emerges as a good alternative in these cases. The
timing of ASA in relation to liver transplantation is still unclear. We report here on the first
case of an orthotopic liver transplant-recipient undergoing ASA and the second of a cirrhotic
patient requiring ASA as a bridge to liver transplantation. Both patients had a good clinical
outcome and we argue that ASA in HOCM patients should be driven by symptom onset, and
that in the asymptomatic patient it can be safely deferred until after liver transplantation.
(Cardiol J 2008; 15: 74-79
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Binary interaction uncertainty in the optimisation of a transcritical cycle: Consequences on cycle and turbine design
Doping CO2 with an additional fluid to produce a CO2-based mixture is predicted to enhance the performance of the super critical CO2 power cycle and lower its cost when adapted to Concentrated Solar Power plants. A consistent fluid mixture modelling process is necessary to reliably design and predict the performance of turbines operating with CO2-based working fluids. This paper aims to quantify the significance of the choice of an Equation of State (EoS) and the uncertainty in the binary interaction parameter
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Loss Analysis in Radial Inflow Turbines for Supercritical CO2 Mixtures
Recent studies have indicated the potential of CO2-mixtures to lower the cost of concentrated solar power plants. Based on aerodynamic and cost considerations, radial inflow turbines (RIT) can be a suitable choice for small to medium sized sCO2 power plants (about 100 kW to 10 MW). The aim of this paper is to quantify the effect of doping CO2 on the design of RITs. This is achieved by comparing the 1D mean-line designs and aerodynamic losses of pure sCO2 RITs with those of three sCO2 mixtures containing tetrachloride (TiCl4), sulphur dioxide (SO2), and hexaflourobenzene (C6F6). Results show that the optimal turbine designs for all working fluids will have similar rotor shapes and velocity diagrams. However, factors such as the clearance-to-blade-height ratio, turbine pressure ratio, and the difference in the viscosity of the fluids cause variations in the achievable turbine efficiency. Once the effects of these factors are eliminated, differences in the total-to-static efficiency amongst the fluids may become less than 0.1%. Moreover, if rotational speed limits are imposed, then greater differences in the designs and efficiencies of the turbines emerge amongst the fluids. It was found that limiting the rotational speed reduces the total-to-static efficiency in all fluids; the maximum reduction is about 15% in 0.1 MW CO2 compared to the 3% reduction in CO2/TiCl4 turbines of the same power. Among the mixtures studied, CO2/TiCl4 achieved the highest performance, followed by CO2/C6F6, and then CO2/SO2. For example, 100 kW turbines for CO2/TiCl4, CO2/C6F6, CO2/SO2, and CO2 achieve total-to-static efficiencies of 80.0%, 77.4%, 78.1%, and 75.5% respectively. Whereas, the efficiencies for 10 MW turbines are 87.8%, 87.3%, 87.5%, and 87.2%, in the same order
Decision support systems classification in industry
This research has presented a discussion of related literature on decision support systems (DSS) and its role in production systems. The first part of the research presents DSS and how this has evolved until 2010. The next part of the research provides a discussion of the decision making process and the data mining phases as these relate to DSS. The last part of the research presents further discussion of DSS and various perspectives on the criteria that could be used for DSS. The criteria in the classification of DSS includes the following: user relationship; orientation; scope of use; type and frequency of decision making; mode of assistance; focus area; objective; capacity; degree of guidance; and, degree of non-procedurality. The research also included a discussion of industry 4.0, which is known as the fourth revolution in the industry
The safety of bivalirudin during elective percutaneous coronary interventions in heart transplant patients
Background: Bivalirudin has been shown to be safe and effective during percutaneous
coronary interventions (PCI) of native coronary arteries in the REPLACE 2 trial. The safety of
bivalirudin during PCIs in heart transplant patients is not known.
Methods: Heart transplant patients who had undergone PCI of de novo lesions and received
bivalirudin during the procedure were included in the study. Medical records were reviewed for
the occurrence of death, myocardial infarction, target vessel revascularization or major bleeding
up to 30 days after discharge. The results were compared with the REPLACE 2 trial and with
a control group of heart transplant recipients who received heparin during their procedures.
Results: There were 51 separate PCIs performed in 30 patients in the study group. The mean
age was 56 ± 12 years and 6 (20%) were women. The control group consisted of 24 patients
who had undergone 35 PCIs. There were no deaths, myocardial infarctions or target vessel
revascularization during the follow-up period in the study group. The combined endpoint of
death, myocardial infarctions, target vessel revascularization and major bleeding requiring
two or more units of packed red blood cells occurred in 2 (3.9%) patients compared to
275 (9.2%) patients in the REPLACE 2 trial (p = 0.195) and 5 (14.3%) in the control group (p = 0.115).
Conclusion: Bivalirudin is a safe antithrombotic medication to use during elective PCI in
heart transplant patients with cardiac allograft vasculopathy. (Cardiol J 2007; 14: 458-462
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