Analysis of Endothelial Protein C Receptor Functionality on Living Cells’

Activated protein C (APC) is a major control system of blood coagulation. APC prevents coagulation pathway by degrading Va and VIIIa plasma’s coagulation factors. Protein C activation requires its binding to specific endothelial cell receptor (EPCR). APC binding to EPCR also activates a wide range of defense mechanisms (anti-inflammatory, antiapoptosis…). EPCR expression by cells can be detected by various methods, including immunoanalysis and molecular biology. However, no assays evaluate its functionality. A method, inspired of a standard fibrinoformation time assay, was developed to estimate EPCR ability to bind APC on living cell surface in vitro. Endothelial cells were incubated with APC and fibrinoformation on cells was followed by spectrophotometry (plasma absorbance increases with fibrin polymerization). Membrane-bound EPCR retain APC, thus prolonging fibrinoformation time in a dose-dependent manner. Control was realized with EPCR-negative cells. This new method can be used on any cell type to study the expression of other coagulation receptors

Influence of cavitation on near nozzle exit spray

The importance of cavitation inside multi-hole injectors for direct injection internal combustion (IC) engineshas been addressed in many previous investigations. Still, the effect of cavitation on jet spray, its stability and liquid breakup and atomisation is not yet fully understood. The current experimental work aims to address some of these issues. It focuses on the initiation and development of cavitation inside a 7x enlarged transparent model of a symmetric 6-hole spark ignition direct injection (SIDI) injector and quantifies the effect of cavitation on near-nozzle spray cone angle and stability utilising high speed Mie scattering visualisation. The regions studied include the full length of the nozzle and its exitjet spray wherethe primary breakup takes place

Link between in-nozzle cavitation and jet spray in a gasoline multi-hole injector

The importance of cavitation inside multi-hole injectors has been addressed in many previous investigations where the cavitation formation and its development, fuel spray characteristics and atomisation have quantified. Different types of geometrical and vortex cavitations have been previously reported inside the nozzles of multi-hole injectors with good indication of their influences on the emerging spray. However, the effect of cavitation on jet spray, its stability and liquid breakup and atomisation is not yet fully understood. The current research work is aimed to address some of the above issues. As the initial phase, the current experimental work focuses on the initiation and development of different type of cavitation inside a 15-times enlarged model of a symmetric 6-hole SIDI injector and tries to quantify the effects of the cavitation on the near nozzle jet spray in terms of jet cone angle and its stability. To achieve this, a high speed camera has been used to visualise the innozzle flow and emerging spray simultaneously

Essays on Option-Implied Measures of Risk

This thesis comprises three studies on extracting the information embedded in option prices. In Chapter One, we propose a new predictor to forecast U.S. real economic activity (REA) by utilising the information embedded in equity option prices. We construct our equity option-based predictor by applying standard and recent data reduction methods, to the cross-section of computed option-implied expected returns of the underlying stocks. Our predictor forecasts REA both in- and out-of-sample setting even after controlling for common REA predictors and considering their persistence. We find a robust negative relationship between the option-implied predictor and REA. We show that individual stocks contain some additional predictive power that is not being captured neither by the index option-implied expected return, nor by standard factors. In Chapter Two, we analyze the impact of Federal Open Market Committee (FOMC) meetings on S&P 500 option markets. We document that volatility and tail risks as well as their premiums increase in the week before meetings, whereas option liquidity decreases. We show that these findings are stronger in weaker economic conditions. In Chapter Three, we review variables available for extracting information from equity option prices. We consider option-implied volatilities, implied risk-neutral skewness and implied expected returns. We discuss how these measures have been used in the literature and document the usefulness of their information in forecasting future prices, asset allocation strategies, corporate events, and the state of the economy. In addition, we comprehensively analyse the cross-sectional predictive power of several option-implied variables for forecasting future equity returns. We show that option-implied measures demonstrate statistically and economically significant predictability for future stock returns

In-nozzle flow spray characteristics in gasoline multi-hole injectors

The current experimental research work is concerned to address different types of cavitation inside the multi-hole nozzle and their impact on the emerging spray stability and atomisation as the effect of cavitation on atomisation is not yet fully understood. The previous studies have provided experimental data addressing unresolved questions about string cavitation origin, area of formation, lifetime and influence on the nozzle hole flow [1] [2] [3] [4] [5] [6]. More importantly, it is aimed to fully characterize the spray structure generated from the new generation stepped multi hole injectors [7] [8]. Thus, this experimental research work has been planned in four phases to address specific issues. The first phase of the experimental investigation was to visualise the in-nozzle flow and cavitation development inside a 15-times transparent enlarged model of a conventional multi-hole injector (6-holes symmetric) using high-speed visualisation (Mie Scattering) technique. A new enlarged model injector was designed that was geometrically similar to phase 1 model but 7-times larger than the real injector. In this regard, cavitation types and development at different flow conditions were visualised. It was found that the geometric and vortex cavitation can significantly affect the spray angle and can induce instability in the spray structure. The underlying mechanisms relating to the interaction of vortex and geometric cavitation and the resulting impact of the bubble pockets and their collapse in the erosion sites was obtained. Two counter rotating vortex cavitation found at the top and bottom of the nozzle inlet which can contribute to erosion at the erosion sites. The results also revealed that the hydraulic flip happens much earlier than expected and at lower cavitation numbers compared to the 15 times enlarged model. It also reveals that a stochastic ligament spray with much lower velocities is being formed at the vicinity close to the upper part of the nozzle exit where the air entrainment seems to be maximum. The wetting phenomena can happen inside the counter bore stepped-hole region of the nozzle or on the curved surface on the tip of the injector nose. In the third phase of the experiment, a real-size stepped injector test rig was designed and manufactured. It also enabled the measurement of the spray tip penetration and cone angle from different viewing angles. It further allowed the visualisation of the overall spray behaviour and very near nozzle exit spray. It was found that stepped-nozzle compared to straight nozzle injector may have flapping of the jets creating snake shape pattern. Unique A shaped with no visible jet boundary was also seen. Higher jet to jet interactions and higher air entrainment were observed compared to other injectors. Tip penetrations of 22mm at 0.25ms, 50mm at 0.75ms ASOI are almost similar to other injectors. Increasing the pressure from 50 bar to 100 bar increases the cone angle significantly from 64 degrees to 72 degrees. In the fourth phase of the experiment, a Fiberflow Dantec PDA measurement system was setup to measure spray characteristics including droplet diameters and velocities at the very near-nozzle area of the injector (1mm from it) up to distance of 35mm from injector tip, to investigate early breakup and spray characteristics. Velocities up to 120m/s at 1mm away from nozzle exit at 100bar are in good agreement with micro-PIV measurements of the in-nozzle flow of transparent model of a similar type of injector at the same injection pressure. Comparison of the average droplet diameter at 1mm away from nozzle exit of the current stepped multi-hole injector (7.5μm) with conventional straight multi-hole (15μm) and outward pintle-type (13μm) at same operation condition shows better atomization performance of this model. The improved atomization performance can be due to the stepped part of the current injector where the fuel undergoes through a sudden expansion process whereby the flow becomes 3-D and highly turbulent and becomes susceptible to earlier breakup and rapid atomization. It was also found that as Jet 1 is slightly contracted, the center of the jet moves slightly downward towards the axis of the spray during the main injection event. Also existence of 4 local peaks in the instantaneous velocity contour plot and the change in their location at different ASOI during the main injection event indicates that there are instabilities in the velocity. Maximum droplet mean diameter, SMD, and Weber number decreases during the main injection event. The injector has Weber number of 8 at 1mm from nozzle exit while outward pintle-type model had Weber number of 25 at 2.5mm away from nozzle exit

Cefixime-induced angle closure and transient myopic shift in a healthy individual; A case report

Purpose: To report a case of Acute bilateral angle closure and Myopia following oral Cefixime therapy for pharyngitis. Observation: A 49-year-old man presented to the clinic with a history of aggravating ocular pain and blurry vision in both eyes from 5 days ago. He was under treatment with oral Cefixime 400 mg twice a day for acute bacterial pharyngitis since last week. His refractive error was �3.75 and �4.25 diopters in the right and left eye respectively. Intraocular pressure (IOP) was 32 mm Hg in the right eye and 40 mm Hg in the left eye. Slit lamp examination and gonioscopy showed shallow anterior chamber with 360° appositional angle closure. Ultrasound biomicroscopy revealed shallow anterior chamber, narrow angle, supraciliary effusion and anterior rotation of ciliary body in both eyes. With diagnosis of drug-induced acute angle closure, oral Cefixime was discontinued and eye drops Betamethasone every 4 hours, Cosopt and Brimonidine twice a day, and Atropine 1 twice a day were started. Few days after starting treatment all ocular symptoms and signs were resolved. Conclusions and importance: Systemic Cefixime can induce acute angle closure disease with myopic shift and elevated IOP secondary to supraciliary effusion and ciliary body rotation. © 202

Optical coherence tomography angiography (OCTA) applications in ocular oncology

Optical coherence tomography angiography (OCTA) is a revolutionary method in the visualization of the vascular system in different retinal and choroidal layers. During the last 4 years since the commercial availability of different OCTA devices, attempts have been made to utilize this technology in various aspects of ocular oncology from the differentiation of benign and malignant lesions to assisting in evaluation of post-treatment complications, such as radiation retinopathy. However, current OCTA technology is restricted by various artefacts and inherent limitations, some of which are more pronounced in the presence of elevated tumoural lesions. Imminent advancements in OCTA systems and image acquisition processes promise a great potential for application of OCTA in ocular oncology. © 2020, The Author(s), under exclusive licence to The Royal College of Ophthalmologists

Networks Perceptions and Job Satisfaction: The Mediating Role of Perceived Organizational Support for Women’s Work Contribution

PurposeThis study investigates the relationship between women’s networks perceptions and job satisfaction. It also examines the mediating effects of perceived organizational support for women’s work contribution on the relationship between networks perceptions and job satisfaction. Design/methodology/approachThe participants are female employees working in Scotland (n = 247). The data were collected using a survey questionnaire. PROCESS macro (model 4, Hayes, 2018) was used to test the proposed model. FindingsThe results revealed that (controlling for work time, age, and sector) there is a significant relationship between women’s networks perceptions and job satisfaction. In addition, POS for women’s work contribution mediates the relationship between networks perceptions and job satisfaction. These findings show the significant effects of networks perceptions on employees’ job satisfaction directly and through POS for women’s work contribution. Therefore, understanding the networks perceptions of employees and organizational factors will assist in improving job satisfaction. Originality/valueThis study is unique for examining the role of POS for women’s work contribution in the relationship between employees’ networks perceptions and job satisfaction. It addresses gender inequality in the workplace in terms of women’s career advancement and job satisfaction. In addition, this research offers insight into the development of a 7-items measurement scale related to networks perceptions. Funding StatementThis reported study was unfunded. Ethical Compliance: All procedures performed in this research involving human participants were in accordance with the ethical standards of the university institutional ethics committee

The prevalence of selected intrinsic risk factors for ankle sprain among elite football and basketball players

Background: Lateral ankle sprains (LAS) are among the most common sports-related injuries and the reinjury rate is very high. Objectives: This study aimed to evaluate the prevalence of some intrinsic risk factors among professional football and basketball players with or without history of acute or recurrent ankle sprain. Patients and Methods: One hundred and six professional football and basketball players who were referred for pre-participation examinations were recruited in this study. Prepared checklist was completed for each participant. Athletes were asked for any history of previous ankle sprain and the severity (based of self-description of signs and symptoms by the athlete), level and number of injuries in the last two years. All players were assessed for measures of foot posture index-6, foot length and width, Beighton generalized joint laxity score, anterior drawer and talar tilt tests, star excursion and single leg balance tests and goniometric assessment of ankle plantarflexion, ankle dorsiflexion and first metatarsophalangeal dorsiflexion. Results: Forty eight basketball players (45.3) and 58 football players (54.7) with mean (SD) age of 19.8 (4.5) years participated. About 58.5 and 14.2 of athletes had a history of ankle sprain and recurrent sprain in at least one extremity, respectively. Sprains were more prevalent in basketball players and in dominant leg. There was no significant difference in assessed risk factors between athletes with and without history of ankle sprain, except for positive single leg balance test which was more prevalent in athletes with history of ankle sprain and also for positive talar tilt test and decreased ankle plantarflexion range of motion in acute and recurrent injury of left ankle. Conclusions: Some intrinsic risk factors including lateral ankle ligaments laxity, balance and ankle plantarflexion seem to be related to acute or recurrent LAS in athletes. Further research is needed to reveal the role of different arthrokinematics following lateral ankle sprain. © 2016, Sports Medicine Research Center