Data on fuzzy logic based-modelling and optimization of recovered lipid from microalgae

This article presents the data of recovered lipid from microalgae using fuzzy logic based-modelling and particle swarm optimization (PSO) algorithm. The details of fuzzy model and optimization process were discussed in our work entitled “Application of Fuzzy Modelling and Particle Swarm Optimization to Enhance Lipid Extraction from Microalgae” (Nassef et al., 2019) [1]. The presented data are divided into two main parts. The first part represents the percentage of recovered lipid using fuzzy logic model and ANOVA. However, the second part shows the variation of the cost function (recovered lipid) for the 100 runs of PSO algorithm during optimization process. These data sets can be used as references to analyze the data obtained by any other optimization technique. The data sets are provided in the supplementary materials in Tables 1–2

Image Quality Assessment and Radiation exposure in Intra Oral Dental Radiography

In this study, an intra oral dental unit (Siemens-70) at King Abdul Aziz University (KAU) Dental Hospital was selected and investigated for visual image quality assessment and radiation protection purposes. Radiation dosimetry for determining the optimum image quality with the lowest radiation exposure to the patient was carried out. A DXTTR dental radiography trainer phantom head and neck, portable survey meter Model RAD EYE-B20, and radiation dosimetry system RADCAL Acuu-pro were used in this study. RADCAL Accu-pro is a non-invasive kV system, reliable instruments to measure and diagnose all X-ray machines including dental units. The radiation exposure to patients in (mGy) was measured using RADCAL ionization chamber Model 10×6-6. The best image quality with the lowest exposure dose was assessed for conventional intraoral X-ray film (Kodak type E) and the digital processing sensor (RVG 5200). Radiation survey level was done during this study for safety and protection purposes

Optimization Methods of Laser Induced Breakdown Spectroscopy (LIBS) and the Self-Absorption Problem

Laser Induced Breakdown Spectroscopy (LIBS) is a well-established technique for determining elemental composition. Compared to conventional methods, its ability to analyze solids, liquids, and gases with little or no sample preparation makes it more versatile and ideal for field, multi-element, and in-situ analysis. The method can be certified for analytical applications of interest in environmental monitoring and quality control processes. Previous work has demonstrated that several different experimental parameters (e.g. laser wavelength, repetition rate, interaction geometry, surface conditions) may affect the effective analytical possibilities of the method. Therefore, many studies have been devoted to optimize such parameters in a way to enhance its figure of merits. In this thesis, LIBS is combined with a spark discharge to operate in a laser triggered spark discharge mode. This Spark Discharge Laser Induced Breakdown Spectroscopy (SD-LIBS) is evaluated for Al and Cu targets in air under atmospheric pressure. Significant enhancement in the measured line intensities and the signal-to-background ratios, which depends on the spark discharge voltage and the laser fluence, is observed in SD-LIBS when compared to LIBS alone for similar laser conditions. The measured line intensities increase with the applied voltage for both targets, and the ratio of the measured line intensity using SD-LIBS to that using LIBS is found to increase as the laser fluence is decreased. For Al II 358.56, such intensity enhancement ratio increases from ∼50 to ∼400 as the laser fluence is decreased from 48 to 4 J/cm2 at an applied voltage of 3.5 kV. Thus, SD-LIBS allows for using laser pulses with relatively low energy to ablate the studied material, causing less ablation, and hence, less damage to its surface. Moreover, applying SD-LIBS gives up to 6-fold enhancement in the SB ratio, compared to those obtained with LIBS for the investigated spectral emission lines. Self-Absorption Laser Induced Breakdown Spectroscopy (SA-LIBS) of compacted brass samples was introduced as a new approach whose principle stems from the well-known Atomic absorption Spectroscopy (AAS) technique. Two closely produced plasmas were generated; one acts as the light source analogous to AAS while the other acts as the analyte thus we let the plasma probe itself. Temporal development of Cu spectral lines was initially obtained in order to examine the lines which are more susceptible to self-absorption. SA-LIBS showed that Cu 324 and 327 nm are significantly subject to self-absorption while Cu 330 nm is not, a result that agrees with those reported in literature. Non-linear calibration curves were also obtained, a problem which was previously demonstrated in several reports for brass samples and was attributed to the difference in ablation rate. Internal standardization of emission lines is a method that results in linear calibration curves. Assuming that the concentration of the absorbing species follows a Gaussian distribution, we tried to solve the familiar Beer-Lambert\u27s law for our specific experimental condition. Linear calibration curves of the logarithm of the absorption and absorbing species concentration or equivalently exponential relationship between them have been obtained. The plasma temperature was about the same for both Zn and Cu species, which is reasonably accepted under the assumption of LTE

Bottom-up surface engineering for the construction of (bio) sensoring systems: design strategies and analytical applications

Specifically outlining the work achieved in this PhD thesis, the work is organised into separate articles that have been published, submitted or are under preparation for submission.Chapter 1 is an introduction, in which the state of the art and objectives are presented. In Chapters 2-4, different potential mediators that could be used for the catalytic interaction with the enzymatic product o-AP were evaluated and due to their well characterized properties, hydrazine, NADH and ascorbic acid were selected for further study. Hydrazine is used as an antioxidant and reducing agent; NADH plays an important rule in oxidoreductases and dehydrogenase systems and ascorbic acid (vitamin C) is an antioxidant whose detection is important in clinical and food applications. The electrocatalytic properties of o-aminophenol films grafted on glassy carbon surfaces have been employed for the electrochemical evaluation of hydrazine, NADH and ascorbic acid, to select the most relevant as a recycling mediator in the planned signal amplification strategy. To evaluate the best mediator, the reaction kinetics between mediators and the o-AP/o-QI were extensively studied using different techniques such as cyclic voltammetry, hydrodynamic voltammetry, double potential step chronoamperometry, and double potential step chronocoulometry. Of them, ascorbic acid was selected as the mediator for regeneration of the o-AP film and substrate recycling. We had thus demonstrated an interesting catalytic system for the oxidation of ascorbic acid, which is stable, sensitive and reproducible, and we decided to explore this system for clinical and food applications. In the first application, we targeted the determination of uric acid (UA) in the presence of ascorbic acid (AA), which commonly co-exist in biological fluids of humans, mainly in blood and urine (Chapter 4). In Chapters 5 and 6, the selective electrocatalytic properties of the grafted o-AP film toward ascorbic acid were also applied to its detection in real samples of fruits and vegetables using disposable one-shot screen printed electrodes. The o-AP modified screen printed electrodes showed high catalytic responses toward the electrocatalytic oxidation of ascorbic acid. The o-AP SPE sensor exhibited high sensitivity and selectivity toward ascorbic acid with excellent storage and operational stability, as well as a quantitatively reproducible analytical performance. In the second part of the thesis, different surface engineering strategies of antibody immobilization for immunosensor construction using a linker or via direct attachment onto a Au surface using a strategy of self assembly were evaluated and compared. An alternative strategy explored was the direct anchoring of the antibody with or without a linker via the electrochemical reduction of their diazonium cations.In Chapter 7, a comparison between these different surface chemistries methodologies for the construction of immunosensors towards the model analyte of coeliac toxic gliadin was carried out. Firstly, the self-assembled monolayer approach was evaluated based on the modification of gold surfaces with two bipodal carboxylic acid terminated thiols (thioctic acid and a benzyl alcohol disubstituted thiol, DT2). A stable SAM of DT2 was rapidly immobilized (3 h) on Au as compared with thioctic acid (100 h), although both surface chemistries resulted in highly sensitive electrochemical immunosensors for gliadin detection using an anti-gliadin antibody (CDC5), with detection limits of 11.6 and 5.5 ng/mL, respectively. The developed immunosensors were then applied to the detection of gliadin in commercial gluten-free and gluten-containing food products, showing an excellent correlation when compared to results obtained with ELISA. In Chapter 8, another approach was explored to further improve immunosensor sensitivity and stability and furthermore to reduce the time necessary for sensor preparation was investigated looking at the direct attachment of the SATA modified full length antibody, and their F(ab) fragments onto Au electrodes. Spontaneously adsorbed SAMs of Fab-SH and CDC5-SH onto Au were rapidly formed in less than 15 minutes. The amperometric immunosensors based on Fab fragments exhibited a vastly improved detection limit as compared to the thiolated antibody with a highly sensitive response toward gliadin detection (LOD, 3.29 ng/ml for amperometric detection and 0.42 g/ml for labelless (impedimetric) detection). Moreover, the self-assembled monolayer of F(ab) fragments was extremely stable with almost no loss in response after 60 days storage at 4oC.In Chapter 9, an alternative surface chemistry approach was explored for the modification of Au electrodes via electrochemical and spontaneous reduction of diazonium cations of a conjugate prepared from the monoclonal full length anti-gliadin antibody (CDC5) and the linker 3,5-bis(aminophenoxy)benzoic acid (DAPBA). Cylic voltammetry was chosen for surface modification via applying three potential cycles, but it was observed that an extensive washing process was necessary after each potential cycle to remove the non-specifically adsorbed molecules or formed multilayers. The affinity of the immobilized antibody toward gliadin was studied using EIS and amperometry. The modified CDC5-DAPBA surface showed a reasonable amperometric response after incubation with 5 g/ml gliadin, and exhibited excellent specificity with no response observed in the absence of the analyte.In Chapter 10, general conclusions and future work are presented. From the different surface chemistry strategies evaluated in this work we can conclude that the best approach is the immunosensor based on the spontaneous adsorption of thiolated F(ab) fragments on gold. This surface is easy and fast to prepare, very stable and sensitive and can be stored for long times in the appropriate conditions without lost of affinity. A good alternative to this approach seems to be the electrodeposition of antibody-diazonium conjugates, although further work is needed in order to optimize this system.Overall, this work has contributed significantly to the vision we have for an immunosensor that avoids washes and reagent addition, where we have selected an excellent mediator for co-encapsulation with alkaline phosphatase enzymes within liposome reporter molecules, for regeneration of surface immobilised substrate following enzymatic dephosporylation, facilitating substrate recycling and increase in sensitivity and reduction in detection limit. Furthermore, we have selected an optimum surface chemistry for co-immobilisation of capture antibody molecules and enzyme substrate via the formation of self-assembled monolayers of antibody fragments on gold surfaces. Future work will focus on combining the selected mediator and surface chemistry into a sandwich immunosensor with a target sensitive liposome reporter molecule, to demonstrate a reagentless, washless ultrasesensitive immunosensing platform.El trabajo descrito en la presente tesis ha sido organizado en capitulos en los que se detallan diferentes artículos publicados, enviados para su publicación o en preparacion en los cuales esta basada la tesis. El Capitulo 1 es una introducción en la que se presenta el estado del arte del tema y los objetivos de la tesis. En los Capítulos 2 a 4 se evalúan las propiedades electrocatalíticas de diferentes mediadores (hidracina, NADH y ácido ascórbico) que podrían ser utilizados en reacciones de reciclado de substratos enzimáticos en estrategias de amplificación de señal en biosensores. La hidracina es usada como antioxidante y agente reductor, el NADH es fundamental para el funcionamiento de oxidorreductasas y deshidrogenasas y el ácido ascórbico (AA, vitamina C) es de gran importancia como antioxidante. Las propiedades electrocatalíticas de monocapas de o-aminofenol (o-AP) en superficies de carbón vítreo fueron empleadas en la caracterización electroquímica de estos mediadores con el objetivo de seleccionar el mediador más adecuado. Para ello se determinaron diferentes parámetros cinéticos asociados empleando voltametría cíclica e hidrodinámica, así como cronoamperometría y cronocoulometría de doble potencial, siendo el acido ascórbico es mas adecuado en términos de coste, respuesta electroquímica y estabilidad. Teniendo en cuenta estas propiedades del AA, se decidió explorar otras posibles aplicaciones clínicas y en análisis de alimentos de este sistema. En primer lugar se estudio la determinación de acido úrico en presencia de AA, el cual coexiste en diferentes fluidos biológicos y se estudió su determinación en muestras reales de orina (Capítulo 4). En los Capítulos 5 y 6 se detalla la utilización de electrodos desechables modificados con o-AP fabricados con la técnica de screen-printing en la determinación de AA de ácido ascórbico en una amplia variedad de frutas y vegetales frescos y zumos comerciales. La selectividad, reproducibilidad y estabilidad de estos electrodos fueron también estudiadas.En la segunda parte de la tesis se evalúan diferentes estrategias para la inmovilización de anticuerpos para la construcción de inmunosensores. Estas estrategias consisten en la deposición de los anticuerpos en superficies de oro mediante autoensamblaje de compuestos tiolados o la electrodeposición de sales de diazonio. En el Capítulo 7 se compara el uso de dos compuestos ditiolados para la modificación de superficies de oro. Estos compuestos se emplearon para la inmovilización de anticuerpos en la construcción de un inmunosensor electroquímico para la detección de gliadina en muestras reales.El Capítulo 8 es la continuación del trabajo anterior y está basado en la adsorción espontánea de fragmentos de anticuerpos o anticuerpos tiolados en superficies de Au para la detección de gliadina. Para ello se compararon las respuestas amperométricas de ambos sistemas, observándose una excelente sensibilidad en el caso de los fragmentos de anticuerpos, asi como una mayor estabilidad (hasta 60 dias a 4ºC) de este sistema. En el Capítulo 9, se estudia una alternativa consistente en la electrodeposición de sales de diazonio conjugadas a anticuerpos. Para ello se estudiaron diferentes métodos de deposicion (electroquímicos o adsorción espontánea), siendo la deposición empleando voltametría ciclica la más adecuada. Sin embargo, esta metodología requirió de un gran número de pasos de lavado para la eliminaciñon de compuestos adsorbidos no específicamente. A pesar de esto, el anticuerpo inmovilizado mostró una buena afinidad hacia la gliadina al ser evaluada por amperometría con una excelente especificidad.El Capítulo 10 consiste en las conclusiones generales y un plan de trabajo para el futuro.De forma general, este trabajo ha contribuido significativamente a la culminación de una estrategia que evita pasos de lavado y de adición de reactivo en el diseño de inmunosensores. Para ello se la seleccionado el mediador más adecuado para coencapsulación con fosfatasa alcalina en liposomas para la regeneración de sustratos inmovilizados en superficies, lo cual facilita su reciclado, así como incrementa la sensibilidad y disminuye los limites de detección. Paralelamente, se han estudiado diferentes superficies para la inmovilización de anticuerpos consistentes en la deposición de los anticuerpos y sus fragmentos en superficies de oro mediante autoensamblaje de compuestos tiolados o la electrodeposición de sales de diazonio. Se propone en el futuro combinar ambas estrategias en la construcción de plataformas inmunosensoras de fácil operatividad y ultrasensibles

Flexible parylene actuator for micro adaptive flow control

This paper describes the first flexible parylene electrostatic actuator valves intended for micro adaptive flow control for the future use on the wings of micro-air-vehicle (MAV). The actuator diaphragm is made of two layers of parylene membranes with offset vent holes. Without electrostatic actuation, air can move freely from one side of the skin to the other side through the vent holes. With actuation, these vent holes are sealed and the airflow is controlled. The membrane behaves as a complete diaphragm. We have successfully demonstrated this function using a 2-mm x 2-mm parylene diaphragm electrostatic actuator valves. This work also includes the novel anti-stiction technology that is crucial to make such large-area parylene actuator diaphragm with the combined use of anti-stiction posts, self-assembled monolayers (SAM), surface roughening, and bromine trifluoride (BrFe) dry etching. With the help of SAM treatment, the operating voltage is lowered from 30 volts to 13 volts. The load deflection method is then used to measure the effective thickness of the composite diaphragm. The flexible parylene diaphragm can be deflected up to 100 μm when 150 Torr of pressure is applied. The result is fitted into a theoretical model and yields an effective thickness of 5.9 μm, which is agreeable with the actual thickness of 5.6 μm, thus proves the functionality of the device

Improving graduate attributes within the Egyptian university sector.

Throughout the years universities have attempted to foster graduate attributes in undergraduate degree courses. Despite the initiatives and funds put in place, attempts have been met with limited success causing what is known as the skills gap. This study sets out to understand the causes underpinning the skills gap by examining the specific nature of graduate attributes through using complexity theory. It builds on earlier work into graduate attributes by investigating the reasons influencing the variation in their interpretation thus providing an analysis of their contextual nature. Rather than determining key factors, this paper examines the multi factor causalities that affect the teaching and learning of graduate attributes in their educational context which requires to be acknowledged in higher education policies and practices. The study was explored in the Egyptian computer engineering undergraduate context. Using semi-structured interviews, a number of questions were posed to a purposive sample of academics and graduates belonging to two different computer engineering undergraduate programmes; one that is private and another that is public. To ensure the validity of data, more data were collected from Egyptian employers as well as the documents that represent the different educational policies and practices implemented in both private and public programmes of study. This research could be of interest to higher education authorities including: universities, deans of faculties, and heads of academic programmes, academics teaching undergraduate bachelor degrees, and course designers and reviewers for undergraduate bachelor degrees

Treatment of Β-Naphthols from Waste Water by Electrocoagulation

The release of poly aromatic hydrocarbons specially β-Naphthols from industrial plants, especially in wastewater effluents discharged from desizing processes in the textile industry, causes many ecological problems that must be solved. These highly contaminated wastewaters contain considerable amounts of dissolved organic carbon, causing a high chemical oxygen demand. Various techniques have been investigated for the removal of these organic pollutants hydrocarbons from contaminated water, including biodegradation, adsorption onto activated carbon, membrane processes, and advanced oxidation processes. These techniques suffer from several technical and economic disadvantages. Although biodegradation is an environmentally friendly process, the rate of hydrocarbon biodegradation is considerably slow and thus requires long reaction times in the range. Electrocoagulation is an important water treatment technology that has been widely used for removing heavy metals and organic pollutants. In the present study, several factors were studied first of them is the EC process parameters such as current density, pH, electrolysis time, electrolyte concentration and initial compound concentration were investigated in terms of their effects on the removal efficiencies of poly aromatic hydrocarbons specially β-Naphthols. The optimum conditions for the removal of β-Naphthols were achieved at current density = 20mA/cm2, pH = 7, NaCl concentration = 1 g/l and temperature of 25°C.Keywords: Organic pollutants, waste water, treatment, electro coagulation

Knowledge, Attitudes, and Utilization of BRCA Testing Among Obstetricians and Gynecologists

Hereditary breast and ovarian cancer (HBOC) is an inherited cancer syndrome that is associated with mutations in the BRCA1 and BRCA2 genes. Carriers of BRCA mutations, both men and women, are at an increased risk for developing certain cancers. Carriers are most notably at an increased risk to develop breast and ovarian cancers; however an increased risk for prostate cancer, melanoma, and pancreatic cancers has also been associated with these mutations. In 2009 the American Congress of Obstetricians and Gynecologists (ACOG) released a practice bulletin stating that evaluating a patient’s risk for HBOC should be a routine part of obstetric and gynecologic practice. A survey was created and completed by 83 obstetricians and gynecologists in the greater Houston, TX area. The survey consisted of four sections designed to capture demographic information, attitudes towards HBOC and BRCA testing, utilization of BRCA testing, and the overall knowledge of respondents with regards to HBOC and BRCA testing. This study found that the majority of participants indicated that they felt that obstetricians and gynecologists should have the primary responsibility of identifying patients who may be at increased risk of carrying a BRCA mutation. Moreover, this study found that the majority of participants indicated that they felt comfortable or very comfortable in identifying patients at an increased risk of carrying a BRCA mutation. However, only about a quarter of participants indicated that they order BRCA genetic testing one to two times per month or more. Lastly, this study demonstrates that the overall knowledge of HBOC and BRCA testing among this population of obstetricians and gynecologists is poor. The results of this study stress the need for more education regarding HBOC, genetic testing, and strategies for identifying patients that may be at risk for having a mutation in a BRCA gene. Furthermore, it reiterates the importance of raising awareness to current practice guidelines and recommendations that can assist obstetricians and gynecologist to better identify and manage patients that may be at an increased risk of having HBOC