Controlling the Density of Plasma Species in Ar/CF4 Radiofrequency Capacitively Coupled Plasma Discharges

In this manuscript, a fluid model is utilized to calculate the density of plasma species assuming geometrically symmetric Ar/CF4 Radiofrequency Capacitively Coupled Plasmas. The electrodes are driven by a sinusoidal waefront with an amplitude of 200 V and a frequency of 13.56 MHz. The gap between the electrodes is 5cm. The plasma species density is calculated as a function of the gas pressure, electron temperature, and the gas composition. In a good agreement with recent experimental results, $CF^+_3$ and F are dominant for all considered simulation parameters. The results explain the pathways to perform atomic layer etching and nanolayer deposition processes. In order to reveal the effect of electron heating on the discharge dynamics, The spatiotemporal electron energy equation is coupled to the fluid model. Tailoring the driven potential has been found to control the concentration of some plasma species. When the plasma is driven with the fundamental frequency, Ohmic and stochastic heating allows electrons to be heated symmetrically. Higher harmonics give rise to an electrical asymmetry and electron heating asymmetry between the powered and grounded sheaths. The electron temperature depends on the driven harmonics; it adjusts gain and loss rates and some plasma species densities

Type of High Secondary School (Governmental Vs Private) and Type of High Secondary School Certificate (Sudanese Vs Arabian): Do They Affect Learning Style?

Background: People differ in the way they perceive, process, store, and recall what they are attempting to learn. This study aimed to assess the learning styles among preclinical 1st year medical students and the influence of the type of high secondary school (governmental vs. private) and type of high secondary school certificate (Sudanese vs. Arabian) on learning style.Materials and Methods: A cross sectional institutional-based study was conducted at Al Neelain University, Khartoum State, Sudan. First year students of Medicine, Dentistry and Physiotherapy Faculties were enrolled. The VARK (Visual, Auditory, Read and write, and Kinesthetic) learning style hard copy questionnaire, © Copyright Version 7.8 (2014) held by VARK Learn Limited, Christchurch, New Zealand was administered following permission. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21.Results: Out of 320 students, 198 correctly completed VARK questionnaires, with mean age of 17.88 years (SD 1.52) and 74.2% were female students. About 59.6% were from governmental schools and 79.4% of the studied students had Sudanese High Secondary Certificates. About 64.1% demonstrated singular mode preference. Inferential statistics showed statistically significant difference between the learning styles and the type of secondary school whether governmental or private (P-value 0.005) while no statistically significant difference in relation to the type of high school certificate of the studied group (P-value 0.225).Conclusion: The type of secondary school whether governmental or private may affect learning style of medical students while student's gender, type of college, or type of high school certificate (whether Sudanese or Arabian) do not. More andlarger studies are encouraged.Key word: Learning modalities, VARK questionnaire, Unimodal preference, Medicaleducation, Sudan

On the Oscillation of Impulsive Neutral First-order Differential Equations with Variable Arguments

Throughout the article, we study the oscillation of a general class of first-order neutral differential equations in presence of variable delays under the effect of impulses. Due to its importance in applications, there are many papers concerning with the property of oscillation and non-oscillation of neutral delay differential equations. Although, a lot of works are concerning with the oscillation of neutral delay differential equations without impulse or impulsive neutral with constant delays, however few papers dealt with the impulsive neutral and those with variable delays. In this paper, we establish sufficient conditions of certain neutral equations with variable delay arguments. New oscillation criteria are deduced. Our results are based on using equivalence transformation and two useful lemmas to prove the obtained criteria. The results of this paper improve those of [20] by adding several non-linear delay functions to the equations instead of having one delay term. Where it is assumed that the two variable delays satisfying a Lipschitz condition. Moreover we discuss more general non-linear delay functions comparing with those used in [14]. Our results improve and extend some recent results in the literature. An illustrative example is given

Corneal biomechanics and biomechanically corrected intraocular pressure in primary open-angle glaucoma, ocular hypertension and controls.

AIMS: To compare the biomechanically corrected intraocular pressure (IOP) estimate (bIOP) provided by the Corvis-ST with Goldmann applanation tonometry (GAT-IOP) in patients with high-tension and normal-tension primary open-angle glaucoma (POAG; HTG and NTG), ocular hypertension (OHT) and controls. Moreover, we compared dynamic corneal response parameters (DCRs) of the Corvis-ST in POAG, OHT and controls, evaluated the correlation between global visual field parameters mean deviation and pattern SD (MD and PSD) and DCRs in the POAG group. METHODS: 156 eyes of 156 patients were included in this prospective, single-centre, observational study, namely 41 HTG and 33 NTG, 45 OHT cases and 37 controls. Central corneal thickness (CCT), GAT-IOP and bIOP were measured, GAT-IOP was also adjusted for CCT (GATAdj). DCRs provided by Corvis-ST were evaluated, MD and PSD were recorded by 24-2 full-threshold visual field. To evaluate the difference in DCRs between OHT, HTG and NTG, a general linear model was used with sex, medications and group as fixed factors and bIOP and age as covariates. RESULTS: There was a significant difference between GAT-IOP, GATAdj and bIOP in NTG and HTG, OHT and controls. NTG corneas were significantly softer and more deformable compared with controls, OHT and HTG as demonstrated by significantly lower values of stiffness parameters A1 and highest concavity and higher values of inverse concave radius (all p<0.05). There was a significant correlation (p<0.05) between MD, PSD and many DCRs with POAG patients with softer or more compliant corneas more likely to show visual field defects. CONCLUSIONS: Corneal biomechanics might be a significant confounding factor for IOP measurement that should be considered in clinical decision-making. The abnormality of corneal biomechanics in NTG and the significant correlation with visual field parameters might suggest a new risk factor for the development or progression of NTG

Left Atrial Appendage Occlusion Versus Direct Oral Anticoagulants in the Prevention of Ischaemic Stroke in Patients with Atrial Fibrillation

Introduction Existing randomised controlled trials assessing the safety and efficacy of left atrial appendage occlusion (LAAO) in atrial fibrillation (AF) were of relatively small sample size, or included patients who could receive oral anticoagulant treatment after device implantation. We compared the outcomes of patients with newly diagnosed AF who received percutaneous LAAO or direct oral anticoagulants (DOAC) treatment, in a large population from a global federated health network (TriNetX). Methods Patients with AF treated with percutaneous LAAO were matched with those treated with DOAC between 1st December 2010 and 1st October 2018. Outcomes were all-cause mortality, ischaemic stroke and intracranial haemorrhage (ICH) at 5 years. Results We included 200 patients with AF, who received either LAAO or DOAC. The risk of all-cause mortality, ischaemic stroke and ICH at 5 years was not significantly different between the two groups (Risk Ratio [RR] for all-cause mortality: 1.52, 95% confidence interval (CI): 0.97- 2.38, RR for ischaemic stroke: 1.09, 95% CI: 0.51- 2.36, and RR for ICH: 1.0, 95% CI: 0.44- 2.30). Conclusion Patients newly diagnosed with AF, eligible for DOAC, showed similar 5-year risk of death, ischemic stroke, and ICH when comparing those who underwent percutaneous LAAO to those receiving DOAC. Future randomised controlled trials are needed to confirm the findings and advise changes in guidelines

Egypt's feminist counterpublic: The re-invigoration of the post-revolution public sphere

This study examines the current feminist counterculture movements which appears to be reinvigorating the Egyptian public sphere. The study argues women in particular have been able to find themselves alternative ways to develop a discourse focused on a desire for social changes around which they can unite. In focusing on lifestyle issues that normally are discussed only in small private spheres, they are able to challenge norms while not provoking the state or security apparatus and avoiding becoming part of the polarised political environment. This article explores the dynamics and motivations of these groups through a case study of three of the networked feminist movements. Our data from semi-structured interviews with the founders show that they grew from networks to movements which then evolved in order to be sustainable. This article argues that through the process of their evolution, these movements are helping strengthen the public sphere and enhance Egyptian democracy

CD34+cells augment endothelial cell differentiation of CD14+endothelial progenitor cells in vitro

Neovascularization by endothelial progenitor cells (EPC) for the treatment of ischaemic diseases has been a topic of intense research. The CD34+ cell is often designated as EPC, because it contributes to repair of ischaemic injuries through neovascularization. However, incorporation of CD34+ cells into the neovasculature is limited, suggesting another role which could be paracrine. CD14+ cells can also differentiate into endothelial cells and contribute to neovascularization. However, the low proliferative capacity of CD14+ cell-derived endothelial cells hampers their use as therapeutic cells. We made the assumption that an interaction between CD34+ and CD14+ cells augments endothelial differentiation of the CD14+ cells. In vitro, the influence of CD34+ cells on the endothelial differentiation capacity of CD14+ cells was investigated. Endothelial differentiation was analysed by expression of endothelial cell markers CD31, CD144, von Willebrand Factor and endothelial Nitric Oxide Synthase. Furthermore, we assessed proliferative capacity and endothelial cell function of the cells in culture. In monocultures, 63% of the CD14+-derived cells adopted an endothelial cell phenotype, whereas in CD34+/CD14+ co-cultures 95% of the cells showed endothelial cell differentiation. Proliferation increased up to 12% in the CD34+/CD14+ co-cultures compared to both monocultures. CD34-conditioned medium also increased endothelial differentiation of CD14+ cells. This effect was abrogated by hepatocyte growth factor neutralizing antibodies, but not by interleukin-8 and monocyte chemoattractant protein-1 neutralizing antibodies. We show that co-culturing of CD34+ and CD14+ cells results in a proliferating population of functional endothelial cells, which may be suitable for treatment of ischaemic diseases such as myocardial infarction