Preparation of novel multifunctional formulations intended for pulmonary delivery

The eradication of pathogenic bacteria in cystic fibrosis (CF) lungs is often unsuccessful because of the poor permeability of the drug through the thick respiratory mucus barrier and biofilm. Nanoparticles are promising carriers due to their ability to cross these barriers and to deliver the loaded drug into the site of action. Nanoparticles exhibit a poor lung deposition; therefore, they need to be transformed into microparticles, which are suitable for dry powder inhalers and thus can be applied pulmonary. In this work, PLGA NPs loaded with Curcumin were produced using microfluidic technology. While using different factors during the manufacturing, their effect on the size and the encapsulation efficiency of the drug was evaluated. Also, the particles showed a fast permeability through the mucus barrier. Furthermore, a novel microparticulate matrix (composed of an antibiotic and N-acetylcysteine) was developed using a spray-drying technique in order to embed the NPs within it and to add even more functionality to the formulation. The aerodynamic properties of microparticles were tested using NGI. Then, their impact on the viscosity of mucus was tested. Additionally, a solid-state characterization and investigations regarding the physical stability of the obtained DPI formulations were performed. Finally, their effect against biofilm formation and inflammation was tested. Summarizing, the formulations represent a promising approach for the future treatment of pulmonary infections in CF.Oft misslingt die Eradikation pathogener Bakterien in Atemwegen von Mukoviszidose Patienten. Grund ist die schlechte Permeabilität des Arzneistoffes durch den pulmonalen Mukus und den Biofilm. Nanopartikel sind hierfür vielversprechende Trägersysteme, da sie diese Barrieren durchdringen und den geladenen Arzneistoff an den Wirkort bringen können. Aufgrund der geringen Deposition von Nanopartikeln in der Lunge ist die Umformulierung der Mikropartikel nötig, damit sie pulmonal appliziert werden können. In dieser Arbeit wurden durch Verwendung von Mikrofluidik Kurkumin beladene PLGA Nanopartikel hergestellt. Der Einfluss verschiedener Herstellungsfaktoren auf Partikelgröße und Verkapselungseffizienz wurde bewertet. Die Partikel zeigten eine rasche Permeation in den Mukus. Mittels Sprühtrocknung wurde eine neuartige Matrix (aus Antibiotikum und N-Acetylcystein) entwickelt, die die Einbettung der Nanopartikel erlaubt und die Funktionalität der Formulierung weiter steigert. Die aerodynamischen Eigenschaften der Mikropartikel wurden mittels NGI untersucht und die Verflüssigung des Mukus wurde nach Anwendung gezeigt. Die Formulierungen für den Pulverinhalator wurden im festen Aggregatzustand charakterisiert und ihre physikalische Stabilität getestet. Schließlich wurde ihre biologische Wirkung (gegen Biofilme und Entzündungsreaktionen) untersucht. Die Formulierungen stellen einen vielversprechenden Ansatz für die künftige Behandlung von pulmonalen Infektionen bei Mukoviszidose dar

The L2 Perceptual Mapping of Arabic and English Consonants By American English Learners

There has been rapid growth in Arabic learning in the United States. With that increase, many learners of Arabic often experience difficulties in learning some Arabic sounds. Among these are the Arabic plain sounds /t, d, ð, s/ and emphatic sounds /tʕ, dʕ, ðʕ, sʕ/. Many studies have proposed that these difficulties are related to the relationship between sounds in learners’ first language (L1) and those in the target language (L2) (Flege, 1987 and 1995; Best, 1995 and 1999; Best, McRoberts, & Sithole, 1988; Best & Tyler, 2007). Previous studies have examined the perceptual patterns of these sounds by relying solely on the articulatory differences between them and the English categories (Al-Mahmoud, 2013). This study first investigates the categorical representations of the plain and emphatic Arabic sounds in the minds of monolingual native speakers of American English in order to establish accurate category mappings between the two languages following Guion et al. (2000). Sixteen listeners participated in an identification task and a goodness-of-fit rating task. Following the sound categorization of the Speech Learning Model (Flege, 1995), the results show that the Arabic consonants /t, d, ð, s, sʕ/ are considered “similar” sounds to the English categories, Arabic /tʕ, ðʕ, dʕ/ are considered “new” sounds. The study also examined whether the L1-to-L2 mappings found earlier differ between naïve monolingual English listeners and L2 Arabic learners. In addition, the study investigates the perceptual development of the Arabic sounds over time with more L2 exposure. Fifty L2 Arabic learners participated in an L1 labeling task, an L2 labeling task, and goodness-of-fit rating tasks. The results show L2 perceptual development for the emphatic sounds but not for the plain sounds. The results show no difference between L1-to-L2 mappings between the naïve monolinguals and experienced L2 learners at the labeling level. However, the results show differences at the goodness-rating level, suggesting subtle L2 perceptual development. The study also investigates the degree of reliance on L1 in order to predict the accuracy of L2 identification by following Park and de Jong’s (2008) quantitative analysis. The results show that it is not clear to what extent L2 learners are using and facilitating their L1 categories in order to perceive L2 sounds. However, the observed accuracy results are successful at showing how L2 exposure affects the overall learnability of L2 emphatic sounds. The study concludes that the perceptual developmental pattern of the emphatic sounds matches the description of SLM’s “new” categories, while the pattern of the plain sounds matches the description of the “similar” sounds

New evaluation of a forgotten American woman writer

Caroline Lee Hentz was a best-selling author. All of her books enjoyed a wide popularity, 100,000 copies being sold in a three year period over her life time. Furthermore, her books continued to sell following her death in 1856. Publishers kept some of the titles in print until the last decade of the century, which indicates that they continued to be in demand. A Philadelphia house, under the successive names of Carey and Hart, A. Hart, and Perry and MacMillan, was Hentz's original publisher. After her death the stereotype plates of all her volumes were purchased by T.B. Peterson and Brothers, also of Philadelphia, who then issued "Peterson's Uniform Edition of the Complete Works of Mrs. Caroline Lee Hentz" guaranteed to be printed on better paper then before. The last discoverable imprint of this edition was in 1889

Multiphase flow measurement in the slug regime using ultrasonic measurement techniques and slug closure model

Multiphase flow in the oil and gas industry covers a wide range of flows. Thus, over the last decade, the investigation, development and use of multiphase flow metering system have been a major focus for the industry worldwide. However, these meters do not perform well in slug flow conditions. The present work involves experimental investigations of multiphase flow measurement under slug flow conditions. A two-phase gas/liquid facility was designed and constructed at Cranfield University. It consisted of a 0.05 m diameter 25 m long horizontal pipeline with the necessary instrumentation. An ultrasonic multiphase metering concept has been proposed and investigated. The concept was based on the combination of non-invasive and non-intrusive ultrasonic sensors and a slug closure model. The slug closure model was based on the "slug unit" model to infer the gas and liquid phase volumetric flowrates. The slug characteristics obtained by non-invasive and non-intrusive ultrasonic techniques were inputs to slug closure model which calculates the factors KI (Liquid), K2 (Liquid), K3 (Gas) and K4 (Gas). These factors are function of the slip ratio in the slug body, flow profile (CO), drift velocity (Vd), liquid holdup and gas void fraction in slug body, slug length, film length, and the total length of the slug unit. Based on ultrasonic sensor measurements, the slug translational velocity was estimated and the slug closure model then calculates the gas and liquid phase volumetric flowrates. Air water slug flow data were gathered and processed for a range of superficial velocities VSL=0.3 to 1.03 ms'1 and VsG=0.6 to 3.01 ms'1. The overall goal of a 5% relative error metering for both phases was not achieved for the conditions tested. The liquid phase percentage errors were from -63.6% to 45.4% while the gas phase percentage errors were from 42% to -14.6%. Key words: slug flow, slug characteristics, slug closure model, non-invasive ultrasonic, non-intrusive ultrasonic, clamp-on transit time ultrasonic flowmeter

Microscopic simulation of superconductor-topological insulator proximity structures

We present microscopic, self-consistent calculations of the superconducting order parameter and pairing correlations near the interface of an $s$-wave superconductor and a three-dimensional topological insulator with spin-orbit coupling. We discuss the suppression of the order parameter by the topological insulator and show that the equal-time pair correlation functions in the triplet channel, induced by spin-flip scattering at the interface, are of $p_x\pm i p_y$ symmetry. We verify that the spectrum at sub-gap energies is well described by the Fu-Kane model. The sub-gap modes are viewed as interface states with spectral weight penetrating well into the superconductor. We extract the phenomenological parameters of the Fu-Kane model from microscopic calculations, and find they are strongly renormalized from the bulk material parameters. This is consistent with previous results of Stanescu et al for a lattice model using perturbation theory in the tunneling limit.Comment: 8 pages, 10 figures; references added in v

Mott scattering at the interface between a metal and a topological insulator

We compute the spin-active scattering matrix and the local spectrum at the interface between a metal and a three-dimensional topological band insulator. We show that there exists a critical incident angle at which complete (100%) spin flip reflection occurs and the spin rotation angle jumps by $\pi$. We discuss the origin of this phenomena, and systematically study the dependence of spin-flip and spin-conserving scattering amplitudes on the interface transparency and metal Fermi surface parameters. The interface spectrum contains a well-defined Dirac cone in the tunneling limit, and smoothly evolves into a continuum of metal induced gap states for good contacts. We also investigate the complex band structure of Bi$_2$Se$_3$.Comment: published versio

Exploring the use of social networking tools among Lebanese students

During the last decade, Social Networking (SN) tools have become increasingly popular and are now an important part of our daily lives. SN tools can be brought into the classroom to bear on some of the challenges the faculty face in enabling students to succeed in their education. This study explores various SN tools used by high school students in Lebanon. It gives insight into students’ suggestions and ideas for various formal learning tasks using SN tools that might be beneficial for teaching and learning. Lebanese students were found to use SN applications in their daily lives extensively, for communication, socialization and various formats of formal and informal learning. The most widely used app was the WhatsApp Instant Messenger. Keywords: social networking tools, formal learning, informal learning

Upstream Multiphase Flow Assurance Monitoring Using Acoustic Emission

An offshore or subsea production facility consists of several satellite wells. The contents of each well are combined and passed onshore via a common pipeline. Each satellite well produces variable quantities of oil, water and gas during its lifetime. However, if different companies own these wells, their flowrates and compositions in pipelines must be monitored and control before any mixing takes plac

Language Anxiety: A Case Study of the Perceptions and Experiences of Teachers and Students of English as a Foreign Language in a Higher Education Institution in the United Arab Emirates

Foreign Language Classroom Anxiety (FLCA) is considered a situation-specific anxiety experienced in the context of the foreign language classroom (MacIntyre & Gardner, 1991a, 1991b, 1994). Despite the growing interest in investigating and exploring the potential causes and manifestations of language anxiety in many Western and Far Eastern countries, the potential sources of this complicated phenomenon have not been widely researched and identified in Arab EFL contexts. The importance of this research rests on a paradigm, which attests the existence of substantial variation through which FLA is experienced not only across cultural groups Horwitz (2001) but also across regions within a specific country (Yan and Horwitz 2008). In order to fill the gap in literature, this mixed method research design study explored and investigated possible factors associated with language anxieties and the coping strategies used by students to alleviate its existence in the hope that the findings contribute to current related literature. Therefore, the current case study comprised two phases. The first phase explored the scope and severity of language anxiety among all Foundation level male students at a Federal college in the UAE. In the second phase of the study, quantitative data were collected using two inventories and one scale with the purpose of investigating the anxiety levels, effects, sources, and beliefs of language learners. In addition, interviews were undertaken with a sample of teachers and students. Focus group (FG) interviews with students were conducted to gain a deeper understanding of the possible sources of anxiety about language learning and its manifestations, as well as consideration of the strategies that may be used to alleviate its negative effects. The purpose of the 1:1 interviews with the teachers was to explore their views and experiences of the phenomenon of language anxiety. Observations of language sessions were also conducted to triangulate the data gathered from the inventories and the teacher and student interviews. The findings show that some of the student participants in this case study experienced moderate to high levels of anxiety in the second language classrooms. Feelings of anxiety could be attributed to a number of interrelated personal and situational related variables. The findings paved the way for a number of implications and recommendations for future research