bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of anatomical variations on insertion forces
Authors: Hügl Silke , Blum Tobias , Lenarz Thomas , Majdani Omid , Rau Thomas S.
Published: September 2018

The choice of a cochlear implant electrode carrier for the individual patient is influenced by cochlear size, as this parameter has an impact on the risk of scala dislocations. Therefore, size and morphology should be represented in artificial cochlear models too, since these are generally used for insertion studies evaluating newly developed cochlear implant electrode carriers and insertion techniques, before human temporal bone studies are applied for. Within this study custom-made electrode carrier test samples were inserted into nine artificial cochlear models of different shape. To fabricate them, four human temporal bone samples have been processed by a serial cross-sectioning technique; the other four samples have been scanned with micro computed tomography. The cochlea was segmented on this data using rotating, midmodiolar slice planes, followed by the generation of a three-dimensional digital model, which finally was projected on a plane and 2D models were milled out of PTFE. The ratios of length to width of the cochlear basal turn of our samples were found to be within previously reported range. For comparative reasons a model used in previous studies was included in this study too. The maximal insertion forces per cochlear model followed a normal distribution. The insertion depth at initial insertion force increase is correlated to the length of cochlear basal turn. Using the here presented cochlear models with varying anatomical measures may help to increase the clinical relevance of insertion studies in artificial cochlear models.
Novel hot-wire based spirometry is highly accurate at low flow rates
Authors: Perera Arshan , Friedrich Petra , Ledermüller Rosina
Published: September 2018

Spirometry is the most commonly used pulmonary function test. The aim of this comparative study was to evaluate four commercially available spirometers with different measurement principles (turbine-, ultrasound-, differential pressure- and hot-wire anemometer). In particular, the measurement accuracy in breathing manoeuvres with low flow rates was investigated, which is highly relevant for paediatric use. Among the tested devices the hot-wire based spirometer showed the highest measurement accuracy at low flows whilst fully complying with the ATS/ERS standards.
MATLAB Simulation Environment for Estimating the Minimal Number and Positions of Cameras for 3D Surface Reconstruction in a Fully-Digital Surgical Microscope
Authors: Wachter Andreas , Kost Jan , Nahm Werner
Published: September 2018

Contemporary surgical microscope systems have excellent optical properties but some desirable features remain unavailable. The number of co-observers is currently restricted, by spatial and optical limitations, to only two. Moreover, ergonomics poses are a problem: Current microscope systems impede free movement and sometimes demand that surgeons take uncomfortable postures over long periods of time. To rectify these issues, some companies developed surgical microscope systems based on a streaming approach. These systems remove some of the limitations. Multi-observer positions, for example, are not independent from each other, for example. In order to overcome the aforementioned limitations, we are currently developing an approach for the next generation of surgical microscope: Namely the fully digital surgical microscope, where the current observation system is replaced with a camera array, allowing real-time 3D reconstruction of surgical scenes and, consequently, the rendering of almost unlimited views for multiple observers. These digital microscopes could make the perspective through the microscope unnecessary allowing the surgeon to move freely and work in more comfortable postures. The requirements on the camera array in such a system have to be determined. For this purpose, we propose of estimation the minimal number of cameras and their positions needed for the 3D reconstruction of microsurgical scenes. The method of estimation is based on the requirements for the 3D reconstruction. Within the MATLAB simulation environment, we have developed a 3D model of a microsurgical scene, used for the determination of the number of required cameras. In a next step a small, compact and costefficient system with few opto-mechanical components could be manufactured.
Comparing distance measures on assessed medical device incident data using Average Silhouette Width
Authors: Bayer Christian , Seidel Robin
Published: September 2018

Many machine learning algorithms depend on the choice of an appropriate similarity or distance measure. Comparing such measures in different domains and on diversely structured data is common, but often performed in regards of an algorithm to cluster or classify the data. In this study, data assessed by experts is analyzed instead. The data is taken from the database of the Federal Institute for Drugs and Medical Devices (BfArM) and represents free text incident reports. The Average Silhouette Width, a cluster density measure, is used to compare the distance measures’ ability to discriminate the data according to the experts’ assessments. The Euclidean distance and four distance measures derived from the Jaccard similarity, the Simple Matching similarity, the Cosine similarity and the Yule similarity are compared on four subsets of this database. The results show, that a better data preprocessing is necessary, possibly due to boilerplate texts being used to write incident reports. These results will also provide the basis to compare improvements by different methods of data preprocessing in the future.
Investigation of balloon dilation devices for treatment of Eustachian tube dysfunction
Authors: Schubert Julia , Wilfling Tamara , Paasche Gerrit , Lenarz Thomas , Schümann Kerstin , Grabow Niels , Schmidt Wolfram , Schmitz Klaus-Peter
Published: September 2018

The presented three different balloon dilation devices for treating Eustachian tube dysfunction were compared regarding their geometries and designs. The balloon dilation behaviour was investigated by an in vitro test setup consisting of a test chamber with 37 °C water, a 2-axis laser scanner and a pressure controller. All balloons could be properly dilated up to the given nominal pressure (NP) or to rated burst pressure (RBP). The balloons reached their expected balloon diameter and length. The compliance data were 1.07 %/atm (TubaVent short), 1.16 %/atm (Acclarent Aera) and 1.28 %/atm (XprESS LoProfile). The measured profile and compliance data can be used for development of new devices for balloon dilation Eustachian tuboplasty.
Balloon-based measuring system for compliance investigations
Authors: Tautorat Carsten , Schümann Kerstin , Specht Olaf , Kamke Frank , Behrens Peter , Schmitz Klaus-Peter , Grabow Niels , Schmidt Wolfram
Published: September 2018

For the development of new stent designs, the compliance of the surrounding biological tissue has to be considered. We expect to obtain parameters for simulation, stent dimensioning, and the forces acting on the stent after implantation. Starting point of the investigations is the commercially available Metricath system allowing cross-sectional lumen area measurements of arteries. Its working principle is based on the pressure-volume relationship using a balloon catheter, which is inflated to a specific pressure of about 250 mmHg and conforms to the shape and size of the lumen. However, for compliance charts multiple pressure levels and a larger pressure range are needed. To overcome this technical limitation, the Metricath balloon catheter is combined with a new inflation device, called pV-Monitor. The presented cross-sectional lumen area measurements in rigid tubes and compliance investigations of elastic tubes demonstrate the feasibility of the pV-Monitor system.
Efficient feature-based motion estimation in neurosurgery using non-maximum suppression
Authors: Chen Fang , Müller Jan , Müller Jens , Tetzlaff Ronald
Published: September 2018

In this contribution we propose a feature-based method for motion estimation and correction in intraoperative thermal imaging during brain surgery. The motion is estimated from co-registered white-light images in order to perform a robust motion correction on the thermographic data. To ensure real-time performance of an intraoperative application, we optimise the processing time which essentially depends on the number of key points found by our algorithm. For this purpose we evaluate the effect of applying an non-maximum suppression (NMS) to improve the feature detection efficiency. Furthermore we propose an adaptive method to determine the size of the suppression area, resulting in a trade-off between accuracy and processing time.
Hydrophilic silicone elastomer with excellent cell adhesion capability - A promising material for ophthalmic micro-implants
Authors: Brietzke Andreas , Grabow Niels , Schmitz Klaus-Peter , Schmidt Wolfram , Siewert Stefan , Guthoff Rudolph , Stahnke Thomas , Kreiner Christine
Published: September 2018

For minimising tissue reactions of implants hydrophilic silicone elastomers feature a high potential to be utilised as material for micro-implants in ophthalmologic pathology. To estimate the biocompatibility we quantified cell viability of human primary fibroblasts from scleral (hSF) and choroideal (hCF) origin in direct contact test and evaluated cell adhesion and cell morphology with Phalloidin- TRITC stained hSF and EA.hy926. Mechanical properties were analysed by means of uniaxial tensile testing. Direct contact testing revealed a good biocompatibility from 65 to 70% relative cell viability for hCF and moderate viabilities (46 to 63%) for hSF. EA.hy926 and also hSF exhibited typical cell morphology on the silicones. Improvement of cell adhesion was observed with increasing amount of hydrophilic component. Mechanical testing shows a minor decrease in elongation at break from 236% to 155% with increasing amount of hydrophilic component. These findings indicate that the investigated silicones may ensure a reliable integration of implants into the ocular tissues.
Optimization of manufacturing processes for biodegradable polymeric stents regarding improved mechanical properties
Authors: Sahmel Olga , Arbeiter Daniela , Schümann Kerstin , Grabow Niels , Siewert Stefan , Schmitz Klaus-Peter
Published: September 2018

Although current drug eluting stents show low risks of in-stent restenosis and stent thrombosis, the presence of a permanent foreign body inside the vessel represents a major limitation. In order to overcome this limitation, stents made of biodegradable polymeric materials are currently being developed. The present work describes an optimized fabrication process for tubular semi-finished products for manufacturing of stents made of poly-L-lactide (PLLA). The impact of the haul-off speed as a major parameter during extrusion processing on the cross-sectional area of tubular specimens was analyzed. It could be shown that the crosssection of the extrudate, in particular the tubing diameter and wall thickness, can be adjusted by varying haul-off speed. In a subsequent blow molding process the influence of the holding time on polymer cold crystallization was analyzed. Thermal properties of the polymeric material after processing were examined by differential scanning calorimetry (DSC). The results showed that there is almost no cold crystallization using a holding time of at least 20 minutes. The investigations showed that semi-finished products with variable geometry and improved mechanical properties can be produced with the described extrusion and blow molding process.
Fabrication and Characterization of Bending- Independent Capacitive CMOS Pressure Sensor Stacks
Authors: Fischer Roland , Ditler Heinrich , Görtz Michael , Mokwa Wilfried
Published: September 2018

Artificial limbs, equipped with miniaturized tactile sensors, can handle objects with more dexterousness. Next to detecting forces, the sensor devices are also able to measure temperature. With this additional information, the touched objects can be better characterized. As such sensors, active CMOS-based capacitive pressure sensors are used in this work. The Sensors are thinned to 20-30 μm target thickness to make them bendable. One challenge of such thin sensors is the strong dependence of the output signal upon bending. To compensate this dependency, two sensors were mounted back to back. This allows a numerical adjustment of the two characteristic sensor output signals to mechanical stress curves. After electrically contacting of the stacks with a 15 μm thin polyimide foil substrate, the bending dependence of the stacks was characterized with a four-point bending procedure. By this characterization the dependency of the pressure sensor output signal on the height of mechanical stress was determined. Both sensor output signals show an inverted behavior under the same mechanical stress which confirmed prior simulation results with the same setup. Based on this information, a numerical method for compensating the bending dependence was successfully proven.
In vitro investigation of the radial compliance of porcine carotid arteries
Authors: Brandt-Wunderlich Christoph , Specht Olaf , Ortmann Heinrich Erik , Schmidt Wolfram , Grabow Niels , Schmitz Klaus-Peter
Published: September 2018

The regaining elastic behavior of the artery after treatment with a bioresorbable scaffold is a measure for successful degradation. The investigation of the elastic properties of arteries is often performed using ultrasound based methods. The current study describes an in vitro test setup for the measurement of the elastic radial compliance of blood vessels with an automated laser scanning device. A porcine carotid artery was placed inside a phosphate buffered saline filled chamber and the outer diameter was measured during stepwise pressurization from 20 mmHg to 160 mmHg. Reference measurements were done with an ultrasound based method. The results show that the automated laser scanning device method provides similar values to the ultrasound measurements. Therefore, the automated laser scanning device method appears to be suitable to investigate radial compliance differences of a stented vessel segment during the degradation process of a bioresorbable scaffold in vitro. The high degree of automation allows for an effective investigation of a larger series of measurements.
Development of a drug-eluting microstent for micro-invasive glaucoma surgery
Authors: Siewert Stefan , Pfensig Sylvia , Großmann Swen , Stiehm Michael , Schmitz Klaus-Peter , Schmidt Wolfram , Kohse Stefanie , Wulf Katharina , Grabow Niels , Kopp Franziska , Guthoff Rudolf
Published: September 2018

Glaucoma represents the leading cause of irreversible blindness worldwide. Therapeutic approaches are based on the lowering of intraocular pressure (IOP). Micro-invasive glaucoma surgery (MIGS) offers perspectives for implant based IOP-reduction with reduced complication rates compared to conventional surgical approaches. Nevertheless, available devices suffer from complications like hypotony and fibrotic encapsulation. The current work focuses on the development of a minimally invasive implantable drugeluting microstent for the drainage of aqueous humour into suprachoroidal or subconjunctival space. Technical feasibility of a micro-scale resorbable nonwoven for the prevention of hypotony and of a drug-eluting coating for the prevention of fibrosis is assessed. Microstent base bodies with a length of 10 mm and an inner/outer diameter of 0.20 mm / 0.35 mm were manufactured. For the prevention of hypotony, resorbable nonwovens with an adequate flow resistance of 1.543 mmHg/μl min-1 were manufactured in the inflow area of microstents. A drug-eluting coating in the outflow area of microstents was developed based on the model drug fluorescein diacetate. Micro-invasive ab interno implantation of a microstent prototype into suprachoroidal space of a porcine eye post mortem was successfully performed, using an injector device. Future studies will focus on the development of an antifibrotic drug-eluting coating and further in vitro, ex vivo and in vivo testing of the devices.
Influence of application parameters of ultrasonic-assisted bone instruments on the tear force of a substitute material for spinal dura mater
Authors: Foelkel Marie C. , Herzog Vitali , Meier Markus , Morlock Michael M.
Published: September 2018

An ultrasonic-assisted bone instrument can be used for the dissection of bone in spinal surgery. During surgery, the tip of such a bone instrument can touch spinal dura mater. Especially during critical re-operations, high forces can be unintentionally applied on spinal dura mater. To prevent dural tears, the influence of application parameters on the tear force shall be analyzed. Collagen foil is used as a substitute material for spinal dura mater because of its similar mechanical properties and structure. Sponge cloth is placed below collagen foil to imitate cerebrospinal fluid and nerve tissue. A 3-axis CNC-machine is used to automate the movement of the bone instrument. In a full factorial experiment the influence of amplitude, shape of movement and velocity of movement on the tear force is analyzed. Amplitude has the strongest effect because of the increase in input energy. Velocity also has a significant influence, probably because of the strain rate increasing with velocity. Thus, a surgeon should mainly reduce the amplitude and furthermore the velocity of movement to generate higher safety in critical areas.
Enhancing haptic feedback of subsurfaces during needle insertion
Authors: Antoni Sven-Thomas , Soltau Stefan , Beringhoff Jens , Rajput Omer , Otte Christoph , Schlaefer Alexander
Published: September 2018

Haptic feedback can be helpful for accurate needle insertion but is complicated by friction on the needle shaft. Concepts to directly measure the forces at the needle tip exist but cause additional cost and complexity. Moreover, haptic devices may show inaccuracies in recreating forces. We present a novel force feedback method that uses needle shaft forces and enhances haptic feedback of subsurfaces based on robotic ultrasound elastography. This approach allows to overcome accuracy limitations of haptic devices. We evaluate our method in a volunteer subject study using recordings from a robotic needle driver setup. We compare haptic feedback based on shaft and enhanced force for the detection of surfaces inside of gelatin phantoms. Using our method, the error of subsurface detection decreased from more than 16 to about 1.7 mm for the first subsurface. A second subsurface was solely detectable using our method with an error of only 1.4 mm. Insertion time decreased by more than 32%. The results indicate that our enhanced sensor is suitable to detect subsurfaces for untrained subjects using a haptic feedback device of limited accuracy.
Standardized technique of water permeability measurement for biomedical applications
Authors: Grossmann Swen , Siewert Stefan , Ott Robert , Schmitz Klaus-Peter , Kohse Stefanie , Schmidt Wolfram , Grabow Niels
Published: September 2018

Standardized methods and measures are ubiquitous in biomedical engineering and a key factor for the successful development and certification of novel biomaterials, implants or other medical devices. Hence, the development of standardized measurement techniques, which can be applied to nearly every material and device is of crucial importance. Within the current work, we introduce a method to evaluate the water permeability according to ISO/FDIS 7198. The setup was designed to determine the volumetric flow through a test sample for a given hydraulic pressure. One key feature is the effortless replacement of the chamber containing the test sample. The measurement technique can thus be applied to a variety of materials and medical devices. To demonstrate the functionality of the setup we fabricated nanofiber membranes using the process of electrospinning. Nonwovens with comparable thickness and varying morphology were analyzed with regard to water permeability. In particular the different fiber diameters as well as the modified inter-fiber distances result in large deviations of the water permeability. Furthermore, there are hints for a rearrangement of the nanofibers due to the applied hydraulic pressure. The developed measurement technique provides a powerful tool for the standardized quantification of the water permeability and can be applied to a variety of biomaterials and medical devices.
Nanofibrous polyamide 6 scaffolds promote adhesion of endothelial cells
Authors: Khaimov Valeria , Kohse Stefanie , Arbeiter Daniela , Grabow Niels , Schmitz Klaus-Peter
Published: September 2018

The usage of synthetic scaffolds is a promising approach in development of implant materials. In this study we fabricated nanofibrous nonwovens of polyamide 6 (PA-6) by means of electrospinning and performed a systematic characterization with regard to the mechanical and biological performance of scaffold materials. Mechanical strength was assessed by uniaxial tensile testing and biological performance was evaluated by measuring cell viability and qualitative analysis of cellular morphology when human umbilical vein endothelial cells (EA.hy926) or human fibroblasts (HT-1080) were grown on polymeric substrates. While all polymeric materials exhibited an excellent biocompatibility with respect to cell viability, their surface topography promoted the adhesion of endothelial but not fibroblast cells. A better understanding of the physicochemical and morphological material properties with a selective impact on cell adhesion will help to further improve biocompatibility of nonwovens for biomedical applications.
Nanostructuring of Titanium by Anodic Oxidation with Sulfuric and Hydrofluoric Acid
Authors: Doll P. W. , Wolf M. , Weichert M. , Ahrens R. , Guber A. E. , Spindler B.
Published: September 2018

Within this work we demonstrate different Anodic Oxidation processes to achieve a broad variety of nanostructures on titanium and the titanium alloy Ti6Al4V for the use as medical implant surfaces. The influence of electrolyte, reaction time and voltage on the nanostructure formation is described as well as the transfer to microstructured surfaces. As electrolytes we investigate sulfuric and hydrofluoric acids with different concentrations. The resulting nanostructures reach from nano porosities over amorphous sponge like structures to self-assembled hexagonal nanotubes.
Integrating a Usability Engineering Process into a Consisting Risk Management
Authors: Scholtes Michael , Buedenbender Stephanie , Behrend Annemarie , Sohrabi Keywan , Gross Volker
Published: September 2018

The complexity of medical devices and its user interactions increases. A growing number of incident reports are assumed to be associated primarily with user errors. This development is tackled through current modifications in standards, such as ISO 13485:2016 and legislations, such as the Medical Device Regulation. Both intensify the focus on use errors significantly. The aim of this paper was the development of a process orientated approach integrating usability engineering into a consisting risk management based on a classic V-model. An appropriate procedure was worked out. For each development step, risk and usability activities were cumulated. Thus, the present paper might help medical device manufacturers to reflect their risk management and usability management processes to find synergies. Prospectively, a step-by-step guide for the integration of risk management and usability engineering based on this approach should be developed.
Low-cost active knee orthoses – a systematic evaluation
Authors: Janzen Swantje , Stewart Kent , Pott Peter P.
Published: September 2018

The aging of humans induces muscle weakness. Muscle weakness results the inability to climb stairs or stand up from a chair and thus, is one of the first steps towards elderly having a less autonomous and self-sufficient life. Therefore, an accessible active knee orthosis, which especially supports these movements would be of great assistance. Recent research projects have focused on feasibility, perfection of motion control and imitation of human movement. For active knee orthoses to be accessible it must be affordable. Hence, this paper systematically evaluates the current research projects around active knee orthosis and discuss the possibilities of implementing a lowcost active knee orthosis.
Challenges of Medical Device Regulation for Small and Medium sized Enterprises
Authors: Wagner Marcel Vila , Schanze Thomas
Published: September 2018

For known reasons, the European Parliament was forced not only to revise the old Medical Device Directive (MDD) and the Active Implantable Medical Devices Directive (AIMDD), but to replace it with the extensive MDR. With the implementation of the Medical Device Regulation (MDR) in May 2017, manufacturers of medical devices will face new challenges for their products in the future, which also have to be implemented in a timely manner. Particularly small and medium-sized enterprises (SMEs) are concerned about whether a timely adaptation to the MDR and their requirements can be implemented. The conversion is associated with a huge effort for all producers of medical devices and certainly, produkt launchers. The purpose of this paper is to get an overview of the most relevant and emerging requirements that manufacturers need to adapt to sell their medical devices in compliance with the MDR regulations. It also explains the extent to which changes and innovations in the MDR are discusses and problems for SMEs.
Pacing electrode modeling and simulation of cardiac contractility modulation
Authors: Roller Tom , Heinke Matthias , Hörth Johannes
Published: September 2018

Cardiac contractility modulation (CCM) is a device-based therapy for the treatment of systolic left ventricular chronic heart failure. Unlike other devicebased therapies for heart failure, CCM delivers nonexcitatory pacing signals to the myocardium. This leads to an extension of the action potential and to an improved contractility of the heart. The modeling and simulation was done with the electromagnetic simulation software CST. Three CCM electrodes were inserted into the Offenburg heart rhythm model and subsequently simulated the electric field propagation in CCM therapy. In addition, simulations of CCM have been performed with electrodes from other device-based therapies, such as cardiac resynchronization therapy (CRT) and implantable cardioverter./.defibrillator (ICD) therapy. At the same distance to the simulation electrode, the electric field is slightly stronger in CCM therapy than in CCM therapy with additionally implanted CRT or ICD electrodes. In addition, there is a change in the electric field propagation at the electrodes of the CRT and the shock electrode of the ICD. By simulating several different therapy procedures on the heart, it is possible to check how they affect their behavior during normal operation. CCM heart rhythm model simulation allows the evaluation the individual electrical pacing and sensing field during CCM.
Journeys/Viaggi: Intertwined multi-university English L2 and Italian L2 courses for bilingual and intercultural growth
Authors: Thonn Jessica A.
Published: September 2018

The University of Florence’s Language Center (CLA) and the Florence seat of an American university renowned for its language programs, Middlebury College, twice intertwined their English and Italian B2/C1 foreign language courses to produce an English/Italian reciprocal learning space. In addition to disparate organizational constructs, the two institutions had slightly differing goals. Both institutions sought multiple, peer-speaking opportunities; however, in addition, Middlebury aimed for intercultural exchange with local peers. To achieve these multiple objectives, our joint courses included elements of group work, collaborative learning, and the latter’s language-acquisition offspring, task-based learning. Research drawn from the fields of management, psychology, pedagogy, sociology, and translation studies, in addition to second language acquisition, guided our instructional design choices. Students worked together outside the classroom, co-constructing knowledge in increasingly complex tasks, to produce tangible outcomes. These joint activities provided students with a space to confront their interpretations and expectations of the L2 culture with an insider’s view. Students experimented with simultaneous, sequential and reciprocal bilingualism. In the second edition of the course, Spanish L1 speakers were present in both universities, co-constructing their knowledge multilingually. The article describes the courses’ format, activities and hurdles, for those interested in setting up bilingual lessons, as well as citing germane studies from a variety of academic disciplines which guided course design.
Student perceptions and attitudes towards the use of Facebook to support the acquisition of Japanese as a second language
Authors: Kelly Niamh
Published: September 2018

Linking Second Language Acquisition theories with a theoretically-grounded socio-constructivist pedagogical approach, this paper documents the attitudes and perceptions of first year language learners using social media (Facebook) as part of their core language module in an Irish university. Results from this study would indicate that while students acknowledge that it can support the acquisition of language, particularly grammatical and lexical knowledge, this does not necessarily mean students like it as a learning tool. Student attitudes are analysed to see if there is evidence of the major tenets of a socio-constructivist pedagogy. The analyis suggest that it supports some such tenets, namely peer-learning, student engagement, collaborative and contextualised learning. There is little evidence that it supports the tenets of motivation, self and peer assessment and a learner-centred approach.
Making languages marketable: An analysis of a promotional brochure for prospective students in an Australian tertiary institution
Authors: Amorati Riccardo
Published: September 2018

Given the implicit disincentive that the native knowledge of a global language poses to the learning of other languages, improvement in student recruitment in language studies is a key priority for educational institutions in English-speaking countries. This paper explores how a major Australian tertiary institution markets five European languages, by focusing on which characteristics of L2 learning are incorporated in the persuasive discourse of a university brochure and on how these are reflective, more or less deliberately, both of L2 motivation theories and of marketing strategies in higher education. It shows that the brochure creates future L2 visions for prospective students through the description of the cultural and instrumental benefits associated with L2 proficiency, and details how to turn this L2 vision into action, by providing a glimpse into L2 learning experiences and by presenting the University as a reputable and trustworthy institution. The study offers a multifaceted theoretical framework which can be utilised in future investigations on a bigger sample of universities and suggests that re-thinking marketing material for language learning in terms of the creation and operationalisation of future L2 Selves could be a fruitful avenue of research with significant implications for student recruitment.
A cognitive approach to L2 Russian and Polish: a case study
Authors: Zherebov Vladimir , Schalley Ewa
Published: September 2018

In this paper we propose a new methodology for teaching third person possessive pronouns in Russian and Polish (его/её/ихRussianjego, jej, ichPolish) as opposed to the reflexive pronounsсвой(Russian)swój(Polish), which always pose significant problems for students learning these languages. In this paper we maintain that the reason for the problem at hand is cognitive in nature: if such a distinction is not present in the mother tongue of the students, they fail to correctly conceptualize the existing difference in the target languages and consequently use the pronouns in question incorrectly. This is based on lack of correct perception rather than lack of theoretical knowledge. The methodology we suggest is based on the practical application of the leading cognitive theories, in particular the Conceptual Integration theory of Fauconnier and Turner.
Spoken language features (and anomalies) in films for ESL classes
Authors: Giampieri Patrizia
Published: September 2018

It is argued that learning a language through films is enjoyable, useful and motivating. At the same time, despite being scripted, film dialogues are claimed to mirror authentic conversational language. This paper is aimed at exploring whether films provide useful and interesting instances of spoken language. These can be used in ESL (English as a Second Language) classes in order to foster second language (L2) learners’ communication skills. To this aim, a trial pedagogical intervention was carried out in which students were exposed to film excerpts and prompted to highlight spoken language features and anomalies. In order to foster learners’ noticing and comparing, the dubbed versions of the film excerpts were also addressed. The paper argues that the many instances of authentic colloquial language in film can be exploited in ESL classes. As far as the dubbed versions are concerned, this paper will demonstrate that not all dialogues are dubbed faithfully and many features of spoken language are unfortunately “lost in translation”. Nonetheless, exposing L2 learners to film sequences in both the original and dubbed versions can be useful in order to raise their awareness and foster noticing and comparing.
CH4 Direct Reduction of In-Flight Fe3O4 Concentrate Particles
Authors: Abolpour Bahador , Afsahi M. Mehdi , Soltani Goharrizi Ataallah
Published: September 2018

In this study, reduction of in-flight fine particles of magnetite ore concentrate by methane at a constant heat flux has been investigated both experimentally and numerically. A 3D turbulent mathematical model was developed to simulate the dynamic motion of these particles in a methane content reactor and experiments were conducted to evaluate the model. The kinetics of the reaction were obtained using an optimizing method as: [-Ln(1-X)]1/2.91 = 1.02 × 10−2dP
−2.07CCH4
0.16exp(−1.78 × 105/RT)t. The model predictions were compared with the experimental data and the data had an excellent agreement.
Determining qualitative effect size ratings using a likelihood ratio scatter matrix in diagnostic test accuracy systematic reviews
Authors: Rubinstein Matthew L. , Kraft Colleen S. , Parrott J. Scott
Published: September 2018

Background

Diagnostic test accuracy (DTA) systematic reviews (SRs) characterize a test’s potential for diagnostic quality and safety. However, interpreting DTA measures in the context of SRs is challenging. Further, some evidence grading methods (e.g. Centers for Disease Control and Prevention, Division of Laboratory Systems Laboratory Medicine Best Practices method) require determination of qualitative effect size ratings as a contributor to practice recommendations. This paper describes a recently developed effect size rating approach for assessing a DTA evidence base.

Methods

A likelihood ratio scatter matrix will plot positive and negative likelihood ratio pairings for DTA studies. Pairings are graphed as single point estimates with confidence intervals, positioned in one of four quadrants derived from established thresholds for test clinical validity. These quadrants support defensible judgments on “substantial”, “moderate”, or “minimal” effect size ratings for each plotted study. The approach is flexible in relation to a priori determinations of the relative clinical importance of false positive and false negative test results.

Results and conclusions

This qualitative effect size rating approach was operationalized in a recent SR that assessed effectiveness of test practices for the diagnosis ofClostridium difficile. Relevance of this approach to other methods of grading evidence, and efforts to measure diagnostic quality and safety are described. Limitations of the approach arise from understanding that a diagnostic test is not an isolated element in the diagnostic process, but provides information in clinical context towards diagnostic quality and safety.
Characterization of Mn-Doped Co3O4 Thin Films Prepared by Sol Gel-Based Dip-Coating Process
Authors: Abdelhak Lakehal , Amar Bouaza , Bedhiaf Benrabah , Cherifa Dalache , Hadj Benhebal
Published: September 2018

In this article, manganese-doped cobalt oxide (Mn-doped Co3O4) thin films have been prepared on glass substrates using sol gel-based dip-coating technique in order to investigate their optical, structural and electrical properties. The Mn concentration was changed from 0 % to 9 %. The synthesized samples were characterized by ultraviolet-visible spectroscopy (UV-visible), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and complex impedance spectroscopy to elucidate the optical, structural, vibrational and electrical properties. Our optical results show that the transmittance of Mn-doped Co3O4 films decreases with increasing doping levels. The optical band gaps were found to be

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for the case of undoped Co3O4 and 9 % Mn-doped Co3O4, respectively. This shift means that the impurities would create energy levels. The structural analysis provides evidence that obtained powders were crystallized in cubic spinel structure. The complementary phase information is provided by FTIR spectroscopy. The FTIR study depicted the presence of four distinct bands characterizing Mn-doped Co3O4 cubic spinel-type structure. The Nyquist plots suggest that the equivalent circuit of Mn-doped Co3O4 films is an RpCp parallel circuit. It was found that the effective resistance Rp decreases, whereas the effective capacitance Cp increases with doping.
Effects of smoking on tooth loss among individuals under periodontal maintenance therapy: a systematic review and meta-analysis
Authors: Vieira Thais Ribeiral , Martins Carolina Castro , Cyrino Renata Magalhães , Azevedo Andrea Mara Oliveira , Cota Luís Otávio Miranda , Costa Fernando Oliveira
Published: September 2018

Abstract: Dental mortality has been reported by longitudinal studies on periodontal maintenance therapy (PMT), but the independent effect of smoking on tooth loss (TL), adjusted for important confounding variables, has been poorly evaluated. This systematic review aimed to assess and analyze the isolated effect of smoking TL among individuals undergoing PMT. Electronic, manual, grey literature, and recent articles (from April 2018) were searched, with no restriction regarding language; respective dates of publication were included. Epidemiological clinical studies reporting TL data among smokers undergoing PMT in comparison to nonsmoker control groups were selected. Methodological quality was assessed using the Newcastle-Ottawa Scale. Meta-analysis was performed, as well as I2 heterogeneity and sensitivity tests. Evidence quality was assessed using GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Eleven papers were included in the systematic review: four case-control and seven cohort studies. Ten out of the 11 studies concluded that smoking was an important risk factor for the occurrence of TL. Meta-analysis of four of the cohort studies found that smokers had 3.24 times the chance of occurrence of TL than nonsmokers undergoing PMT (95%CI: 1.33-7.90). Overall, studies’ risk of bias was low. The quality of the scientific evidence moderately supports that smokers undergoing PMT have a greater chance of TL than nonsmokers.
Association between the employment status and the presence of depressive symptoms in men and women in Mexico
Authors: Fernández-Niño Julián Alfredo , Bonilla-Tinoco Laura Juliana , Astudillo-García Claudia Iveth , Manrique-Hernández Edgar Fabián , Giraldo-Gartner Vanesa
Published: September 2018

Abstract: This study aims to estimate the relationship between employment status and depressive symptoms among Mexican adults, as well as to explore its differential effect by gender. Cross-sectional study of 36,516 adults between 20 and 59 years of age taken from the 2012 Mexican National Health and Nutrition Survey. Depressive symptoms were evaluated using the Center for Epidemiologic Studies Depression Scale (CES-D), and the employment status was determined a week before the survey. Logistic regression models were stratified by gender and education level and adjusted by sociodemographic and health-related conditions to estimate the association between depressive symptoms and employment status. The prevalence of clinically depressive symptoms was 7.59% for men and 18.62% for women. In the case of men, those who were unemployed were more likely to present depressive symptoms (OR = 1.66; 95%CI: 1.08-2.55) than those who were working. For women, employment status is not associated with the presence of depressive symptoms, except in students (OR = 1.57; 95%CI: 1.02-2.43) compared with those who were working. In both genders, disability preventing one from working was associated with depressive symptoms. Although being employed has been reported to be associated with lower levels of psychiatric morbidity, the estimated effect is different for men and women. Occupational health policies should consider these conditions.
Saúde bucal de adolescentes rurais quilombolas e não quilombolas: um estudo dos hábitos de higiene e fatores associados
Authors: Silva Etna Kaliane Pereira da , Santos Patrícia Reis dos , Chequer Tatiana Praxedes Rodrigues , Melo Camila Moreira de Almeida , Santana Katiuscy Carneiro , Amorim Maise Mendonça , Medeiros Danielle Souto de
Published: September 2018

Resumo Este estudo avaliou os hábitos de higiene bucal e sua associação com fatores socioculturais, ambientais e relacionados à utilização de serviços odontológicos entre adolescentes rurais quilombolas e não quilombolas do interior da Bahia. Foi um estudo transversal realizado em 2015. Estimaram-se prevalências e razões de prevalências para os desfechos e foi conduzida análise múltipla por regressão de Poisson com variância robusta. Foram entrevistados 390 adolescentes, 42,8% quilombolas. Escovação dentária insatisfatória e não uso do fio dental foram encontrados em 33,3% e 46,7% dos adolescentes, respectivamente. Mostraram aumentar a escovação dentária insatisfatória: sexo masculino (RP = 1,45), não morar com ambos os pais (RP = 1,45), menor hábito de lavar as mãos (RP = 1,72) e pior autoavaliação da saúde bucal (RP = 1,38). Com o não uso de fio dental, mostraram-se associados: nível econômico E (RP = 1,54), maior idade (RP = 0,91) menor hábito de lavar as mãos (RP = 1,53) e pior autoavaliação da saúde bucal (RP = 1,33). Distintos fatores associados foram observados entre quilombolas e não quilombolas. Ressalta-se a necessidade de se considerar as especificidades das populações para a promoção da saúde bucal dos adolescentes e a importância da intersetorialidade entre educação e saúde e a atenção às famílias.
Políticas de Saúde de adolescentes e jovens no contexto luso-brasileiro: especificidades e aproximações
Authors: Schaefer Rafaela , Barbiani Rosangela , Nora Carlise Rigon Dalla , Viegas Karin , Leal Sandra Maria Cezar , Lora Priscila Schmidt , Ciconet Rosane , Micheletti Vania Dezoti
Published: September 2018

Resumo O objetivo deste artigo é caracterizar a produção científica sobre políticas e programas de saúde de adolescentes no Brasil e em Portugal no período 2010-2017. Estudo de revisão da literatura, baseado no método de “Scoping Review”. A questão de investigação: como se caracteriza a produção científica sobre políticas e programas de saúde de adolescentes do Brasil e de Portugal? As buscas foram realizadas no mês de outubro de 2017, nas plataformas BVS, EBSCO e Google Acadêmico. Foram selecionados 22 estudos, 17 brasileiros e 5 portugueses. Foram identificadas sete categorias temáticas transversais: avaliação de políticas e programas; promoção e educação para a saúde; saúde mental; saúde sexual e reprodutiva; violência; saúde bucal e saúde nutricional. Conclui-se que, embora em contextos sociais distintos, as temáticas refletem áreas tradicionais de intervenção das políticas e programas, com exceção daquelas decorrentes do fenômeno da violência estrutural, marcadamente presente na realidade brasileira. Ainda, ausência de temáticas emergentes como identidades de gênero, fluxos migratórios e morbimortalidade por causas externas, revelando possível vazio assistencial das políticas e programas e um campo necessário a ser explorado.
Desafios da atenção à anorexia nervosa na adolescência: etnografia em serviço público de saúde no Rio de Janeiro, Brasil
Authors: Castro Priscila da Silva , Brandão Elaine Reis
Published: September 2018

Resumo O artigo busca, por meio de pesquisa antropológica etnográfica, refletir sobre a dinâmica de funcionamento cotidiano de um serviço público de saúde especializado no atendimento aos transtornos alimentares, bem como sobre o processo de adoecimento vivenciado por adolescentes que enfrentam publicamente a anorexia nervosa. O Programa de Transtornos Alimentares observado no Rio de Janeiro oferta atendimento ambulatorial e possibilidade de internação hospitalar. O trabalho de campo propiciou o conhecimento sobre a atenção prestada aos adolescentes e seus familiares, bem como as dificuldades vivenciadas pela equipe multiprofissional. A convivência mais estreita da pesquisadora no serviço de saúde possibilitou identificar os muitos desafios que perpassam a relação profissional de saúde-usuários, desmotivação profissional frente à complexidade da doença, falta de qualificação para tratar adolescentes, dentre outros obstáculos. Busca-se salientar a importância dessa temática para o campo da Saúde Coletiva no Brasil, com o desenvolvimento de diretrizes para orientar os serviços de saúde, bem como de políticas públicas de saúde que promovam a criação de programas, ações e atividades visando dar visibilidade e assegurar direitos aos portadores de transtornos alimentares no país.
Experimentação e aprendizagem na trajetória afetiva e sexual de jovens de uma favela do Rio de Janeiro, Brasil, com experiência de aborto clandestino
Authors: Ferrari Wendell , Peres Simone , Nascimento Marcos
Published: September 2018

Resumo Este artigo aborda o tema da iniciação sexual na adolescência, com foco nas narrativas de dez jovens com experiência de aborto induzido, moradoras de uma favela do Rio de Janeiro. A análise lança mão da descrição do processo de entrada na sexualidade como estratégia para elucidar o contexto da gravidez e do primeiro aborto clandestino na trajetória afetivo-sexual das jovens aqui entrevistadas. Considera-se a iniciação um domínio da sexualidade e da vida social que envolve socialização, interpretação de regras e significados, sistema de atitudes, formas de aproximação, controle e modelação dos afetos, das emoções e das relações de gênero. Os resultados mostraram que a diferença de idade entre os pares na iniciação amorosa sexual é significativa, clarificando o contexto em que ocorreram as decisões sobre métodos contraceptivos, gravidez e aborto. Notou-se que as adolescentes se submetem a difíceis decisões sobre sua sexualidade e reprodução, em um momento de vida em que ainda lhes falta experiência sexual e reprodutiva. A partir dos dados, demonstra-se a importância do fortalecimento de políticas públicas, discussões sobre gênero e direitos sexuais e reprodutivos na adolescência em diversos âmbitos da sociedade, como escola, família e demais instituições.