162 research outputs found
Non-Invasive Imaging for the Assessment of Cardiac Dose and Function Following Focused External Beam Irradiation
Technological advances in imaging and radiotherapy have led to significant improvement in the survival rate of breast cancer patients. However, a larger proportion of patients are now exhibiting the less understood, latent effects of incidental cardiac irradiation that occurs during left-sided breast radiotherapy. Here, we examine the utility of four-dimensional computed tomography (4D-CT) for the accurate assessment of cardiac dose; and a hybrid positron emission tomography (PET) magnetic resonance imaging (MRI) system to longitudinally study radiation-induced cardiac effects in a canine model.
Using 4D-CT and deformable dose accumulation, we assessed the variation caused by breathing motion in the estimated dose to the heart, left-ventricle, and left anterior descending artery (LAD) of left-sided breast cancer patients. The LAD showed substantial variation in dose due to breathing. In light of this, we suggest the use of 4D-CT and dose accumulation for future clinical studies looking at the relationship between LAD dose and cardiac toxicity.
Although symptoms of cardiac dysfunction may not manifest clinically for 10-15 years post radiation, PET-MRI can potentially identify earlier changes in cardiac inflammation and perfusion that are typically asymptomatic. Using PET-MRI, the progression of radiation-induced cardiac toxicity was assessed in a large animal model. Five canines were imaged using 13N-ammonia and 18F-fluorodeoxyglucose (FDG) PET-MRI to assess changes in myocardial perfusion and inflammation, respectively. All subjects were imaged at baseline, 1 week, 4 weeks, 3 months, 6 months, and 12 months after focused cardiac irradiation. To the best of our knowledge PET has not been previously used to assess cardiac perfusion following irradiation.
The delivered dose to the heart, left ventricle, LAD, and left circumflex artery were comparable to what has been observed during breast radiotherapy. Relative to baseline, a transient increase in myocardial perfusion was observed followed by a gradual return to baseline. However, a persistent increase in FDG uptake was observed throughout the entire left ventricle, including both irradiated and less-irradiated portions of the heart.
In light of these findings, we suggest the use of this imaging approach for future human studies to assess mitigation strategies aimed at minimizing cardiac exposure and long-term toxicity subsequent to left-sided breast irradiation
Predictors of Angio access failure in end stage renal disease patients in Southern Egypt
Background: Hemodialysis (HD) seems to be the most often used Renal Replacement Therapy (RRT) modality worldwide, and it is the primary modality in the majority of instances with extended RRT. The ability to provide our patients with high-quality HD treatment while also increasing their chances of survival is heavily reliant on the functionality of the vascular access (VA). Despite the fact that it is a very necessary component of all clinical practise standards, it is the most expensive individual component of RRT.Objectives: This study was aimed at comparing between the group with Angio access failure and group without Angio access failure and predicting Angio access failure among end stage renal failure patients in Southern Egypt.Subjects and Methods: a prospective cohort study among 125 patients with end stage renal failure at Aswan University. The research comprised patients who had NCVA placement [intra-atrial catheter (IAC) and trans-lumbar catheter (TLC)] between January 1, 2020, and December 31, 2020.Results: The duration of previous RRT was significantly higher among the Angio access failure than the group without Angio access failure. In multivariate analysis using logistic regression, the age, duration of previous RRT, diabetes, IHD (ischemic heart disease), PVD (peripheral vascular disease) and CVD (cardiac vascular disease) were significantly direct predictors of the Angio access failure in the first one year.Conclusion: In conclusion the failure of Angio access was positively associated with age, previous RRT and other comorbidities
Endovenous Laser Ablation, Radiofrequency Ablation and Flebogrif versus Conventional Surgery in Treatment of Primary Varicose Vein of the Lower Limb: Prospective Randomized Controlled Study
Background: Endovenous laser ablation (EVLA), radiofrequency ablation (RFA) and mechanochemical ablation (MOCA) of primary varicose vein are thought to minimise postoperative morbidity and reduce work loss compared with the conventional surgical procedure.
Objective: To determine, whether endovenous ablation methods (radiofrequency, laser and mechanochemical) have any advantages or disadvantages in comparison with conventional surgery, in the treatment of primary varicose vein.
Patients and Methods: This was a prospective randomized study, conducted on forty patients presented at Vascular Outpatient Clinic for management of chronic venous insufficiency. All patients underwent clinical examination and duplex ultrasonography. Ten (10) patients were treated with ligation and stripping of the great saphenous vein (GSV). Ten (10) patients were treated with radiofrequency ablation. Ten (10) patients were treated with endovenous laser ablation. Ten (10) patients were treated with Flebogrif.
Results: Compared with conventional surgery, endovenous ablation methods reduced postoperative discomfort and pain, with a lower complication rate after treatment for avoidance of a groin incision and dissection at the saphenofemoral confluence. Cosmetic demands were also better satisfied. Non-controlled clinical trials have shown that the ablation rate of GSV after EVLA is over 90%. However, risks of EVLA, RFA and Flebogrif remain in terms of recanalization and neoreflux via junctional tributaries.
Conclusion: RFA, EVLA, and Flebogrif are minimally invasive procedures. Their potential early benefits, by avoiding groin dissection and GSV stripping, have been confirmed by the findings from this trial. Current evidence based on randomized trials consistently demonstrates significant early benefits after RFA, EVLA and Flebogrif in suitable patients with varicose veins
Geological and Geotechnical Assessment of Gabal Ataqa Dolostones, for Pavement Construction in Egypt
Aggregate is a collective term for the mineral materials such as sand, gravel and crushed stone. By weight, aggregate generally occupies about 92-96 percent of the hot mix asphalt (HMA), and about 79-85 percent of the Portland cement concrete (PCC). Aggregate is also used for Base and Sub-base courses for both flexible and rigid pavements. This research aims to investigate the geological and geotechnical properties of Gabal Ataqa dolostone for pavement construction projects in Egypt. A total of six dolomite microfacies were recognized and classified according to the dolomite rock classification. The X-Ray Diffraction (XRD) analysis showed that Ataqa dolostones consist mainly of dolomite (89.79%) and calcite (7.74%), while quartz (2.3 %) and halite (0.18 %) were found in small amounts in some samples. Generally Ataqa dolostone is around stoichiometric (50.96%), and may belong to dolomite of late diagentic coarse crystalline dolomite. The chemical investigation showed that the major elements of the investigated dolostone rocks are SiO2 (1.72 %); CaO (32.03%), MgO (19.18%), Fe2O3 (0.22 %), Na2O (0.11%), and Al2O3 (0.05%) while the loss on ignition is about (46.19 %.). The trace elements consist of strontium (116 ppm), barium (14.0 ppm); and very low amount of zirconium (3 ppm). Petrographic, chemical, mineralogical, and compressive strength of Ataqa dolostone rocks beside, geotechnical properties of the produced coarse aggregates were investigated. Los Angeles abrasion, apparent specific gravity, water absorption, disintegration, and stripping were evaluated. The results of the conducted testing indicate that Ataqa dolostone rocks are suitable for road construction and concrete industry.
Dual solutions and stability analysis of a hybrid nanofluid over a stretching/shrinking sheet executing MHD flow
In this paper, the unsteady magnetohydrodynamic (MHD) flow of hybrid nanofluid (HNF) composed of Cu−Al2O3 /water in the presence of a thermal radiation effect over the stretching/shrinking sheet is investigated. Using similarity transformation, the governing partial differential equations (PDEs) are transformed into a system of ordinary differential equations (ODEs), which are then solved by using a shooting method. In order to validate the obtained numerical results, the comparison of the results with the published literature is made numerically as well as graphically and is found in good agreements. In addition, the effects of many emerging physical governing parameters on the profiles of velocity, temperature, skin friction coefficient, and heat transfer rate are demonstrated graphically and are elucidated theoretically. Based on the numerical results, dual solutions exist in a specific range of magnetic, suction, and unsteadiness parameters. It was also found that the values of f′′(0) rise in the first solution and reduce in the second solution when the solid volume fraction ϕCu is increased. Finally, the temporal stability analysis of the solutions is conducted, and it is concluded that only the first solution is stable
Comparison Study between Opioid Free and Opioid Based General Anesthesia in Functional Endoscopic Sinus Surgeries
Background: Functional endoscopic sinus surgery is a standard procedure for the treatment of chronic sinusitis. This surgery is usually conducted under general anesthesia and it is better to be performed under controlled hypotensive technique to improve surgical field and to decrease the operation time. Routine analgesic treatment is usually based on non-opioid analgesics with rescue opioids.
Objective: The aim of this study was to compare opioid free versus opioid based general anesthesia in functional endoscopic sinus surgeries regarding hypotension, surgical field, operation time and postoperative pain. Patients and methods: Patients were divided into 2 equal groups: Group 1: Opioid free group: (Group OFA) 22 participants, Group 2: Opioid based group: (Group OBA) 22 participants. All participants were subjected to medical history taking, complete clinical examination and premedication and routine laboratory investigations.
Results: There was no statistical significant difference between the studied groups regarding the mean arterial pressure, oxygen saturation and need for analgesia. Duration of stay in post anesthesia care unit was significantly shorter in OFA group than OBA group. OBA Group was significantly associated with higher VAS score at 6-, 10- and 12-hours postoperatively.
Conclusion: OFA provided satisfactory intraoperative analgesia and control of surgery-induced pressor reflexes. Also, the perioperative safety and efficacy of the opioid-free anesthesia techniques provided for functional endoscopic sinus surgeries had good postoperative analgesia and other postrecovery criteria. There is a need for wider-scale comparative studies with large number of patients with long period in multi-center studies to confirm our finding
Bacteriophage ZCSE2 is a Potent Antimicrobial against Salmonella enterica Serovars: Ultrastructure, genomics and efficacy
© 2020 by the authors. Developing novel antimicrobials capable of controlling multidrug-resistant bacterial pathogens is essential to restrict the use of antibiotics. Bacteriophages (phages) constitute a major resource that can be harnessed as an alternative to traditional antimicrobial therapies. Phage ZCSE2 was isolated among several others from raw sewage but was distinguished by broad-spectrum activity against Salmonella serovars considered pathogenic to humans and animals. Lytic profiles of ZCSE2 against a panel of Salmonella were determined together with low temperature activity and pH stability. The morphological features of the phage and host infection processes were characterized using a combination of transmission electron and atomic force microscopies. Whole genome sequencing of ZCSE2 produced a complete DNA sequence of 53,965 bp. No known virulence genes were identified in the sequence data, making ZCSE2 a good candidate for phage-mediated biological control purposes. ZCSE2 was further tested against S. Enteritidis in liquid culture and was observed to reduce the target bacterium to below the limits of detection from initial concentrations of 107–108 Colony Forming Units (CFU)/mL. With a broad host-range against pathogenic Salmonella serovars, phage ZCSE2 constitutes a potential tool against a major cause of human and animal disease
Effects of stefan blowing and slip conditions on unsteady MHD casson nanofluid flow over an unsteady shrinking sheet: Dual solutions
In this article, the magnetohydrodynamic (MHD) flow of Casson nanofluid with thermal
radiation over an unsteady shrinking surface is investigated. The equation of momentum is derived
from the Navier–Stokes model for non-Newtonian fluid where components of the viscous terms
are symmetric. The effect of Stefan blowing with partial slip conditions of velocity, concentration, and temperature on the velocity, concentration, and temperature distributions is also taken into account. The modeled equations of partial differential equations (PDEs) are transformed into the equivalent boundary value problems (BVPs) of ordinary differential equations (ODEs) by employing similarity transformations. These similarity transformations can be obtained by using symmetry analysis. The resultant BVPs are reduced into initial value problems (IVPs) by using the shooting method and then solved by using the fourth-order Runge–Kutta (RK) technique. The numerical results reveal that dual solutions exist in some ranges of different physical parameters such as unsteadiness and suction/injection parameters. The thickness of the velocity boundary layer is enhanced in the second solution by increasing the magnetic and velocity slip factor effect in the boundary layer. Increment in the Prandtl number and Brownian motion parameter is caused by a reduction of the thickness of the thermal boundary layer and temperature. Moreover, stability analysis performed by employing the three-stage Lobatto IIIA formula in the BVP4C solver with the help of MATLAB software reveals that only the first solution is stable and physically realizable
Stability analysis of the magnetized casson nanofluid propagating through an exponentially shrinking/stretching plate: Dual solutions
In this research, we intend to develop a dynamical system for the magnetohydrodynamic (MHD) flow of an electrically conducting Casson nanofluid on exponentially shrinking and stretching surfaces, in the presence of a velocity and concertation slip effect, with convective boundary conditions. There are three main objectives of this article, specifically, to discuss the heat characteristics of flow, to find multiple solutions on both surfaces, and to do stability analyses. The main equations of flow are governed by the Brownian motion, the Prandtl number, and the thermophoresis parameters, the Schmid and Biot numbers. The shooting method and three-stage Lobatto IIIa formula have been employed to solve the equations. The ranges of the dual solutions are fwc1≤fw and λc≤λ , while the no solution ranges are fwc1>fw and λc>λ . The results reveal that the temperature of the fluid increases with the extended values of the thermophoresis parameter, the Brownian motion parameter, and the Hartmann and Biot numbers, for both solutions. The presence of dual solutions depends on the suction parameter. In order to indicate that the first solution is physically relevant and stable, a stability analysis has been performed
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