bluuebunny/crossref_metadata_2025 huggingface dataset:
Blocking Coalitions and Fairness in Asset Markets and Asymmetric Information Economies
Authors: Bhowmik Anuj , Gabriella Graziano Maria
Published: September 2019

This paper analyses two properties of the core in a two-period exchange economy under uncertainty: the veto power of arbitrary sized coalitions; and coalitional fairness of core allocations. We study these properties in relation to classical (static) and sequential (dynamic) core notions and apply our results to asset markets and asymmetric information models. We develop a formal setting where consumption sets have no lower bound and impose a series of general restrictions on the first period trades of each agent. All our results are applications of the same lemma about improvements to an allocation that is either non-core or non-coalitionally fair. Roughly speaking, the lemma states that if all the members of a coalition achieve a better allocation in some way (for instance, by blocking the status quo allocation or because they envy the net trade of other coalitions) then an alternative improvement can be obtained through a perturbation of the initial improvement.
Deep Learning for Prediction of Diaphragm Activity from the Surface Electromyogram
Authors: Bockelmann Niclas , Graßhoff Jan , Hansen Lasse , Bellani Giacomo , Heinrich Mattias P. , Rostalski Philipp
Published: September 2019

The electrical activity of the diaphragm (EAdi) is a novel monitoring parameter for patients under assisted ventilation and is used for assessing the patient’s neural respiratory drive. It is recorded by an array of electrodes placed inside the esophagus at the level of the diaphragm. A noninvasive alternative is the measurement of the electromyogram by means of skin surface electrodes (sEMG). The respiratory sEMG signal, however, is subject to electrocardiographic interference and crosstalk from other muscles and may also pick up a different part of the muscular activity. In this work, we propose to use a deep neural network to predict the electrical activity of the diaphragm as measured by a nasogastric catheter from sEMG measurements. We use a ResNet based architecture and train the network to directly regress the EAdi as a supervised learning task - we further investigate a heatmap based regression approach. The proposed methods are evaluated on a clinical dataset consisting of 77 recordings from mechanically ventilated patients. For the direct regression task, the network’s predictions reach a Pearson correlation coefficient (PCC) of 0.818 with EAdi on the hold-out set. The heatmap regression increases the PCC to 0.830 while at the same time achieving a lower mean absolute error, indicating a superior performance. From our results we conclude that sEMG measurements may be used to predict the internal activity of the diaphragm as measured invasively using a nasogastric catheter.
A computer-assisted optimization approach for orthognathic surgery planning
Authors: Weichel Frederic , Eisenmann Urs , Richter Sarah , Hagen Niclas , Rückschloß Thomas , Freudlsperger Christian , Dickhaus Hartmut
Published: September 2019

Orthognathic surgery is used to treat misaligned jaws in adults by repositioning them. Intervention planning has to take into account different clinical, anatomical, functional, and aesthetic parameters to determine the optimal position. Current planning systems usually present 3D surface models obtained from a CT or Cone-Beam scan of the patient. The surgeon then interactively positions the upper and lower jaw. Thus, the surgeon can manually optimize anatomical aspects but has to consider functional and aesthetic effects simultaneously, which may be error-prone. We are developing a computer-assisted planning system which generates an optimized position for both jaws based on different analyses (cephalometric, plaster model, photostat) of the head, using a gradient descent algorithm. For this purpose, landmarks are interactively identified on a 3D surface representation. The system is developed as a plugin for MITK utilizing a knowledge base realized in the sematic web standard RDFS, which is queried with SPARQL requests. In a preliminary evaluation with five different cases we compare the automatically generated planning proposal with the planning results of a maxillofacial expert (ground truth). Good general agreement is observed, although more research for the identification and development of 3D cephalometric analyses is needed.
Self-adapting Classification System for Swallow Intention Detection in Dysphagia Therapy
Authors: Riebold Benjamin , Nahrstaedt Holger , Schauer Thomas , Seidl Rainer O.
Published: September 2019

In dysphagia the ability of elevating the larynx and hyoid is usually impaired. Electromyography (EMG) and Bioimpedance (BI) measurements at the neck can be used to trigger functional electrical stimulation (FES) of swallowing related muscles. The height and speed of larynx elevation can be assessed by evaluating the BI during a swallow. For the triggering of an supporting FES and for biofeedback online detection of swallow onsets is required. Patients can practice by a gamified biofeedback to swallow harder, swallow in a timely manner or to maintain the larynx elevation for a longer time period (Mendelson maneuver). The success of the stimulation and biofeedback therapy as well as the acceptance by the patient strongly depends on the precise detection of swallow onsets. We have introduced a classification algorithm based on a random forest classifier to trigger FES in phase with voluntary swallowing based on EMG and BI. Although the classification is successful in healthy subjects, difficulties appear in the utilization on some patients. The reason for this can be found in a strongly varying residual swallow activity. Usually the activity of EMG and change in BI are smaller in patients compared to healthy subjects. Thus an adaption procedure is needed, that can be easily applied. In this paper we introduce an algorithm that is capable to find an optimal classifier for a patient in terms of sensitivity. The adaption algorithm uses a small number of recorded swallow onsets of a patient at the beginning of a therapy session to evaluate different classifiers and to pick the most suitable for the treatment. The set of random forest classifiers has been trained with data from healthy subjects by step wise shifting the class weights of swallows and non-swallows, yielding classifiers with different sensitivities. The evaluation is done using data from 41 patients. It showed that the sensitivity of the classification can be increased by 4 to 6 % in average compared to fixed classifiers, but up to 66 % for individual patients. Finally, we studied the effect this adaptive classifier in triggered stimulation therapy in a single dysphagia patient. Swallowing performance was measurements during one week of therapy consisting of eleven therapy session. An improvement of 40 and 63 % in larynx elevation and speed could be observed, respectively.
HRV (Heart Rate Variability) as a non-invasive measurement method for performance diagnostics and training control
Authors: Scherer Matthias , Martinek Johannes , Mayr Winfried
Published: September 2019

The aim of this study was to determine whether non-invasive heart rate variability (HRV) recordings can be used to monitor training exercises and to estimate athletic performance. Thus far, condition and performance have been evaluated with lactate test procedures and spirometry. Several tests were conducted to determine the relationship of data from lactate test samplings, spirometry and HRV recordings. Four groups of professional athletes in different disciplines such as ball sports (n=15), martial arts (n=17), endurance sports (n=8) and hobby athletes (n=6) underwent a standardized treadmill or bicycle ergometer step test while increasing load rates, e.g. 2 km/h or 20-50 Watt every 3.5 minutes, synchronized with standardized series of lactate test sampling, spirometry and ECG recording. An inclusion criterion for all athlete groups was a minimum training frequency of an hour, five days a week focusing on continuous performance improvement. Evidence shows that offline analysis of ECG data allows conclusions on actual individual athletic performance without the need for complex instrumentation and laboratory environment. The total power parameter of the HRV reaches a plateau phase in all tested subjects and this plateau phase reaches zero near the 2 mmol threshold of lactate concentration in all subjects recorded on a bicycle ergometer. Nine out of ten subjects measured on the bicycle ergometer had negatively correlating data of lactate concentration and total power of HRV (α < 0.05). Lactate measurements using treadmills require resting periods for blood sampling. As the HRV increases instantly in these resting periods, the use of bicycle ergometers, where no testing breaks are needed, is recommended for further research.
Computational flow analysis of the washout of an aortic valve by means of Eulerian transport equation
Authors: Stiehm Michael , Borowski Finja , Kaule Sebastian , Ott Robert , Pfensig Sylvia , Siewert Stefan , Schmitz Klaus-Peter , Öner Alper Ö , Grabow Niels
Published: September 2019

Although the development of the transcatheter aortic valve (TAV) has saved many lives of inoperable patients and has a very good clinical outcome, concerns about valve thrombosis are increasing. Due to the potential risk of late clinically relevant events, the US Food and Drug Administration (FDA) suggests a careful systematic investigation of thrombosis and reduced leaflet motion related to hemodynamic changes induced by TAV implantation. Furthermore, recently published position papers of the ISO working group address numerical and experimental flow field assessment of TAV. In particular, pathologically high shear rates and a reduced washout of the sinuses may increase the risk of valve thrombosis and should therefore be investigated. By means of fluid-structure interaction (FSI) as a powerful in silico tool, the transient flow field in an aortic valve was analyzed. A linear elastic behavior was assumed for leaflet material properties (Young modulus: 10 MPa, Poisson ratio: 0.46 and leaflet material density: 1000 kg/m3) and blood was specified as a homogeneous, Newtonian and incompressible fluid (fluid density: 1060 kg/m3 and a dynamic viscosity: 0.0035 Pa s). In this numerical study we present a Eulerian approach, which is based on transport equation of the residence time (RT) as a passively transported scalar. It can be clearly seen that the RT is significantly higher in the sinus referred to the main flow. At time step t = 0.25 s, the average residence time in the main flow is RTavg ≈ 0.05 s, whereas RT ≈ 0.25 s in the sinus. In particular, RT is a valuable hemodynamic metric to quantify the washout of the sinus in order to evaluate the thrombogenic potential of TAV devices. Further studies will concentrate on particle image velocimetry measurements for validation purposes. In particular the velocity in the sinus and therefore the washout is one important hemodynamic key feature that has to be improved for future TAV designs.
Usability assessment of patient hoists as a purchasing guide for health facilities
Authors: Müller Lorenz , Sobkowicz Saskia , Ibenthal Elisabeth , Backhaus Claus
Published: September 2019

Nurses suffer from musculoskeletal strains because of frequent patient mobilizations. Therefore, mobile patient hoists were developed. However, patient hoists are rarely used. A possible reason is a low user acceptance due to poor usability of available products. To increase the user acceptance in health facilities and thus the frequency of use, a comparative usability assessment was conducted. The goal is to support health facilities in future purchasing decisions. 12 hoists were tested by 40 nurses in three everyday scenarios. Every nurse tested three hoists in randomized order. In total, each hoist was tested ten times. The success rate was used to measure the effectiveness. To identify poorly designed components, success rates were clustered into categories, which describe different hoist parts. User acceptance was quantified in the range of 0 to 100 using a standardized questionnaire. The success rate over all hoists was high and ranges from 88 % to 95 % (M = 92 %, SD = 2 %). However, serious use errors occurred in 24 % of the scenarios. The slingbars of the hoists showed the lowest effectiveness (M = 82 %, SD = 6 %). The user acceptance of the hoists ranges from 49 to 86 (M = 68, SD = 10). Besides structural problems like limited space or product availability, design deficits are a possible reason, why hoists are not used. All in all, the study identifies ergonomically better-designed hoists. Based on the results, health facilities can take usability aspects into account when making purchasing decisions.
Biodegradable magnetic microspheres for drug targeting, temperature controlled drug release, and hyperthermia
Authors: Zahn Diana , Weidner Andreas , Saatchi Katayoun , Häfeli Urs O. , Dutz Silvio
Published: September 2019

Magnetic microspheres (MMS) used for magnetic drug targeting consist of magnetic nanoparticles (MNP) and a pharmaceutical agent embedded in a polymeric matrix material. The application of MNP for drug targeting enables guiding the MMS to a target area, imaging the position of the MMS with magnetic particle imaging, and finally inducing drug release. As latter takes place by degradation of the MMS or diffusion through the matrix, an increase in temperature, e.g. through magnetic hyperthermia, leads to an accelerated drug release. Here, MMS consisting of poly(lactic-coglycolic) acid (PLGA) with different monomer ratios were prepared by an oil-in-water emulsion evaporation method. The model drug Camptothecin (CPT) and magnetic multicore nanoparticles (MCNP) with a high specific heating rate were embedded into the microspheres. We obtained MMS in the preferred size range of 1 to 2 μm with a concentration of MCNP of 16wt%, a drug load of about 0.5wt% and an excellent heating performance of 161 W/gMMS. Investigations of the drug release behaviour showed an accelerated drug release when increasing the temperature from 20 °C to 37 °C or 43 °C by using a water bath. In addition, an increase in drug release of about 50% through magnetic heating of the MMS up to 44 °C compared to 37 °C was observed. By this, a magnetic hyperthermia induced CPT release from PLGA MMS is demonstrated for the very first time.
Experimental Study on Cell-free Approach for Articular Cartilage Treatment
Authors: Dursun Gözde , Markert Bernd , Stoffel Marcus
Published: September 2019

Cell-free based approaches are introduced as a promising treatment method for articular cartilage. The success of this method requires cell colonisation from resident tissue into cell-free implants. The objective of our study is to promote the cell colonisation into cell-free collagen I based implants by mechanical stimulation. Therefore, a new in vitro cellular model consisting chondrocyte-seeded matrix and cell-free implants was developed in a polydimethylsiloxan (PDMS) mold. These constructs were cultured under dynamic and static culture conditions. For the dynamic culture, we have developed an in-house bioreactor system where both the load and the deformation applied to the specimen are recorded. Cyclic compression, with a strain of 5% and frequency of 0.1 Hz, was applied to constructs without any break. At the end of three days of dynamic and static cultivation, the cell-free implants were seperated from cell-seeded matrix and cultured in a petri dish three days long. Afterwards, they were analysed using fluoresence dyes. The microscopic assessment indicated that there was a cell migration into the cell-free implants which were cultured dynamically.
Intelligent Assistant System for the Automatic Assessment of Fall Processes in Sports Climbing for Injury Prevention based on Inertial Sensor Data
Authors: Munz Michael , Engleder Thomas
Published: September 2019

In this work, an assistant system is presented for the automatic assessment of falling and belaying in sport climbing. Both climber and belayer are equipped with inertial measurement unit (IMU) sensors. Forces as well as movements in the form of multi-dimensional accelerations on the legs and torso are captured. It can be shown that forces can be estimated by means of IMU sensors, thus eliminating a complex force measurement unit in the safety chain. Furthermore, the data can be used to assess both falling and belaying by automatic segmentation and evaluation algorithms. The sensor data should later be evaluated automatically in order to objectively measure faulty behavior by climber or belayer (for example wrong jump-off behavior, too hard protection, etc.). The overall goal is to provide quantified feedback in fall training for injury and accident prevention.
Development of an antifibrotic drug-eluting coating for a minimally invasive implantable glaucoma microstent
Authors: Siewert Stefan , Reske Thomas , Pfensig Sylvia , Großmann Swen , Stiehm Michael , Schmitz Klaus-Peter , Schmidt Wolfram , Grabow Niels , Stahnke Thomas , Guthoff Rudolf
Published: September 2019

Primary open angle glaucoma represents an eye disease that usually is associated with an increased intraocular pressure (IOP). Implants for micro-invasive glaucoma surgery (MIGS) are gaining importance as a promising option for IOP lowering. Currently available devices are implanted into the eye ab interno based on a clear corneal incision and drain aqueous humour into the schlemm’s canal, suprachoroidal or subconjunctival space. Fibrosis is known as a major limitation for long term success and often leads to the necessity of an additional medication or a surgical re-intervention. The current work focusses on the development of an antifibrotic drug-eluting coating for a minimally invasive implantable glaucoma microstent. Tubular microstent base bodies manufactured from a polycarbonate based silicone elastomer were spray-coated with a chloroform based mixture of the same polymer and the antifibrotic drug pirfenidone (PFD, P2116, Merck KGaA, Germany) in a polymer/drug ratio of 85/15% (w/w). Coating mass of 89 μg according to a drug loading of 1.96 μg mm-2 was aspired. Coating mass was measured using an ultramicrobalance (XP6U, Mettler-Toledo International, Inc., Switzerland). Glaucoma microstent prototypes with a drugeluting coating mass of (84 ± 19) μg (n = 12) were manufactured. Characterization by means of scanning electron microscopy (Quattro S, Thermo Fisher Scientific, FEI Deutschland GmbH, Germany) yielded a reproducible smooth surface of the coating. High performance liquid chromatography (KNAUER Wissenschaftliche Geräte GmbH, Germany) was used for analysis of drug release behaviour in 0.9% NaCl solution at 37°C. The in vitro PFDrelease is characterized by an initial burst phase of approximately 6 h followed by a more retarded release phase. The entire drug was released within 36 h (n = 3). Sterilization processing has a minor impact on drug release kinetics. Appropriate drug stability after sterilization could be proven. Future studies will focus on the antifibrotic properties of drug-eluting glaucoma microstents in animal studies.
Validation System for Digital Stethoscopes
Authors: Klum Michael , Stehling Julian , Pielmus Alexandru , Tigges Timo , Orglmeister Reinhold
Published: September 2019

Stethoscope auscultation is a diagnostic method widely used by medical professionals. With the introduction of digital stethoscopes, auscultation sound analysis has been objectified, which led to an increased interest in the field. Until today, however, no standard to assess the acoustical properties of stethoscopes is available. Some approaches use phantoms mimicking the properties of human soft tissue. In most cases, however, the properties of the phantoms have not been analyzed with respect to environmental variables. In our work, we propose a stethoscope characterization system for the frequency range between 50 Hz and 2.5 kHz with a small financial footprint. We analyzed its frequency behavior over temperature, time and position on the phantom and derived quantitative recommendations for environmental variables. Finally, the frequency response of a commercial digital stethoscope was characterized at different pressure levels. We conclude that the presented system is capable to stably and reproducibly assess the transfer function of digital stethoscopes. We hope that future stethoscope designs will be characterized with respect to their acoustical properties.
Integrating Label Uncertainty in Ultrasound Image Classification using Weighted Support Vector Machines
Authors: Hagenah Jannis , Leymann Sascha , Ernst Floris
Published: September 2019

Inference from medical image data using machine learning still suffers from the disregard of label uncertainty. Usually, medical images are labeled by multiple experts. However, the uncertainty of this training data, assessible as the unity of opinions of observers, is neglected as training is commonly performed on binary decision labels. In this work, we present a novel method to incorporate this label uncertainty into the learning problem using weighted Support Vector Machines (wSVM). The idea is to assign an uncertainty score to each data point. The score is between 0 and 1 and is calculated based on the unity of opinions of all observers, where u = 1 if all observers have the same opinion and u = 0 if the observers opinions are exactly 50/50, with linear interpolation in between. This score is integrated in the Support Vector Machine (SVM) optimization as a weighting of errors made for the corresponding data point. For evaluation, we asked 15 observers to label 48 2D ultrasound images of aortic roots addressing whether the images show a healthy or a pathologically dilated anatomy, where the ground truth was known. As the observers were not trained experts, a high diversity of opinions was present in the data set. We performed image classification using both approaches, i.e. classical SVM and wSVM with integrated uncertainty weighting, utilizing 10-fold Cross Validation, respectively (linear kernel, C = 7). By incorporating the observer uncertainty, the classification accuracy could be improved by 3.1 percentage points (SVM: 83.5%, wSVM: 86.6%). This indicates that integrating information on the observers’ unity of opinions increases the generalization performance of the classifier and that uncertainty weighted wSVM could present a promising method for machine learning in the medical domain.
Aspects of Multimodal Hybrid Biomaterials
Authors: Jennissen H. P.
Published: September 2019

Immobilizing a single growth factor such as rhBMP-2 on Implant materials can significantly increase the integration of implants into bone in animals. Paradoxically the effective osteoinductive dose of rhBMP-2 in humans is ca. 100-1000-fold higher than in animals and may induce serious side effects in spine fusion surgery. In physiological bone healing at least 10 separate growth and differentiation factors are sequentially involved in the first two healing phases leading to a callus and/or woven bone. It is therefore hypothesized that a significant dose reduction for rhBMP-2 applications in humans may be achieved by a combination of rhBMP-2 with other growth factors in a biomimetically oriented manner. Some aspects involved in multimodal bioactive hybrid carriers with spatio-temporal release kinetics and a new phenomenon ("protein interference") are presented.
Interactive Image Segmentation for Cochlea Implant Planning based on DVT Data
Authors: Killguß Nathalie , Wittenberg Thomas , Franz Daniela , Eixelberger Thomas , Rupp Robin , Hofer Mathias
Published: September 2019

Cochlea Implant (CI) planning is usually based on preoperative obtained CT or MRI data, visualising risk structures in the petrosal bone. In the past years, Digital Volume Tomography (DVT) with an increased spatial resolution and reduced radiation has become more important in the clinical routine for otology. In this work we propose an extension of our interactive “wizard”-guided approach for the interactive segmentation of the middle and inner ear structures for the use with DVT data. Different filter pipelines enable the user to interactive segment the acoustic canal, ossicles, tympanic cavity, facial nerve, chorda tympani, round window, cochlea and semicircular canals. The approach has been evaluated on six pre-operative acquired DVT datasets by an ENT expert. Results imply that the proposed method can handle DVT well and can potentially be used for interactive OR planning.
Development of a smart fabric force-sensing glove for physiotherapeutic Applications
Authors: Spilz Andreas , Engleder Thomas , Munz Michael , Karge Marius
Published: September 2019

In this work, a low-priced smart fabric forcesensing glove is developed which is able to measure the total amount and direction of the force a person applies on a patient in a physiotherapeutic context. A device like this would be beneficial for the education of physiotherapists, to measure the progress of a patient and to evaluate the treatment. The proposed device uses a new sensor, which is based on a piezoresistive fabric. This fabric changes its electrical resistance according to the applied stress. The characterization of this sensor revealed that the change in resistance of the sensor is dependent of the amount of force, the loaded area, the total time the sensor is loaded and hysteresis. To compensate these behaviours, an additional sensor based on the same smart fabric was developed which measures the loaded area of the first sensor. By combining these two sensors, it is possible to calculate the applied force. The results show the feasibility to build a measurement system out of smart fabric material that can measure the applied force. Furthermore, the prototype shows promising results in determining the applied force in amount and direction.
Model of SpO2 signal of the neonate
Authors: Huttova Veronika , Rafl Jakub , Möller Knut , Bachman Thomas E. , Kudrna Petr , Rozanek Martin , Roubik Karel
Published: September 2019

The advantages of automatic control of the fraction of inspired oxygen in neonates have been documented in recently published clinical trials. Many control algorithms are available, but their comparison is missing in the literature. A mathematical model of neonatal oxygen transport could be a useful tool to compare and enhance both automatic control algorithms and manual control of fraction of inspired oxygen. Besides other components, the model of neonatal oxygen transport must include a module linking arterial (SaO2) and peripheral (SpO2) oxygen saturation. The pulse oximeter module must reflect issues of SpO2 measurement typical for clinical practice, such as overestimation of SpO2 over SaO2 documented by several studies, or inaccurate pulse oximeter readings due to high noise. The aim of this study was to describe both the bias between SaO2 and SpO2 and the noise, characteristic for continuous SpO2 recording, for a computer model of oxygenation of a premature infant. The SpO2-SaO2 bias, derived from available clinical data, describes a typical deviation of the SpO2 measurement as a function of the true SaO2 value in three different SaO2 intervals. The SpO2 measurement noise was considered as a random process that affects biased SpO2values at each time point with statistical properties estimated from SpO2 continuous recordings of 5 stable newborns. The results of the study will help to adjust a computer model of neonatal oxygenation to the real situations observed in the clinical practice.
Guiding and Accumulation of Magnetic Nanoparticles Employing High Intensity Focused Ultrasound for Drug Targeting Applications
Authors: George Benedikt , Fink Michael , Ermert Helmut , Rupitsch Stefan J. , Lyer Stefan , Alexiou Christoph
Published: September 2019

Magnetic Drug Targeting (MDT) is a cancer treatment technique that enables a local chemotherapy. In MDT, chemotherapeutic drugs are bound to magnetic nanoparticles and are accumulated in the tumor area by means of an external magnetic field. Unfortunately, a single magnet can only generate a pulling magnetic force. However, in some applications a pushing force on the nanoparticles could be advantageous. One way to realize pushing forces is to exploit the acoustic radiation force based on the nonlinearity of sound propagation in fluid media generated by a high intensity focused ultrasonic transducer. In this context, we built a test setup was built to investigate the utility of High Intensity Focused Ultrasound (HIFU) to generate a pushing force on the magnetic nanoparticles. The results show that the acoustic radiation force can be employed for particle guidance to achieve concentration differences similar to those obtained by using an electromagnet.
Evaluation of MRI-compatible pneumatic muscle stepper motors
Authors: Odenbach Robert , Guthrie Alan , Friebe Michael
Published: September 2019

The automation of instruments and tools (e.g. bone drill) or robotic devices (e.g. needle positioning robot for prostate surgery) for use in interventional MRI (iMRI) is still challenging due to a lack of accurate, affordable and completely metal-free actuators and motors. Inspired by biological muscles, a bionic equivalent known as the fluid muscle actuator (which can be operated pneumatically or hydraulically) is well-known in the mechanical engineering industry. Fluid muscle actuators have multiple beneficial characteristics: they are simple, self-returning, low-friction and can produce relatively high actuation forces at low diameters and pressures. We present two novel designs for metal-free, pneumatic stepper motors for potential application in iMRI. Our stepper motors are powered by simple pneumatic muscles, which are assembled from low-cost off-the-shelf components. Besides, the components of the stepper motor demonstrators were 3Dprinted using a stereolithographic additive manufacturing process (SLA printing). We evaluate the effect of pneumatic muscle length on contractile force and length. Our results demonstrated the functional feasibility of the pneumatic muscle-powered and fully MRI-compatible stepper motor designs. In a next step, we will optimize the motor´s design, characterize their performance and reliability, and use the stepper motors to power a micropositioning device in iMRI-phantom tests.
Perspectives from the other side of the screen: how clinicians and radiologists communicate about diagnostic errors
Authors: Lama Anna , Hogg Jeffery , Olson Andrew P.J.
Published: September 2019

Background

Miscommunication amongst providers is a major factor contributing to diagnostic errors. There is a need to explore the current state of communications between clinicians and diagnostic radiologists. We compare and contrast the perceptions, experiences, and other factors that influence communication behaviors about diagnostic errors between clinicians and radiologists.

Methods

A survey with questions addressing (1) communication around diagnostic error, (2) types of feedback observed, (3) the manner by which the feedback is reported, and (4) length of time between the discovery of the diagnostic error and disclosing it was created and distributed through two large academic health centers and through listservs of professional societies of radiologists and clinicians.

Results

A total of 240 individuals responded, of whom 58% were clinicians and 42% diagnostic radiologists. Both groups of providers frequently discover diagnostic errors, although radiologists encounter them more frequently. From the qualitative analysis, feedback around diagnostic error included (1) timeliness of error, (2) specificity in description or terminology, (3) collegial in delivery, and (4) of educational value through means such as quality improvement.

Conclusions

Clinicians and radiologists discover diagnostic errors surrounding the interpretation of radiology images, although radiologists discover them more frequently. There is significant opportunity for improvement in education and practice regarding how radiologists and clinicians communicate as a team and, importantly, how feedback is given when an error is discovered. Educators and clinical leaders should consider designing, implementing, and evaluating strategies for improvement.
5-Year review on amniocentesis and its maternal fetal complications
Authors: Jummaat Fauziah , Ahmad Shuhaila , Mohamed Ismail Nor Azlin
Published: September 2019

Background

Amniocentesis is a well-known invasive procedure which is commonly carried out in the second trimester. The indication for amniocentesis varies throughout countries and centers. Despite providing significant prenatal diagnosis; many maternal and fetal complications have been reported from previous studies.

Materials and methods

This retrospective study aimed to determine the maternal and fetal complications following amniocentesis. This study involved all patients who underwent amniocentesis from January 2012 until June 2017 in a tertiary centre. Maternal age, parity, premorbid medical conditions, amniocentesis indications, gestational age during amniocentesis, karyotyping results, complications during and post procedure and the fetal outcomes were reviewed and analyzed.

Results

One hundred and fourteen patients’ medical records were reviewed and the majority of patients (50.9%) ranged in age from age 30 to 39 years old with mean age of 34.29 years. Amniocentesis was performed during the second trimester in the majority of patients (71.1%). The indications for amniocentesis in this study were polyhydramnios (7.9%), advanced maternal age (9.6%), risk of Down’s syndrome (31.6%), increased risk of Patau syndrome (6.1%), increased risk of Edward’s syndrome (4.4%) and abnormal fetal ultrasonography (70.2%). Cytogenetics results of amniocentesis were normal in 82 patients (71.9%). The majority of patients (86.0%) had no complications. Two patients (12.5%) had intrauterine death presumed to be procedural related.

Conclusion

This 5-year retrospective study on amniocentesis procedure showed that the majority of amniocentesis were safe as 86.0% of the patients were free from any complications. Anticipating its complication is important as there is always a risk even though it is a safe procedure in general.
Structural investigations of cell-free expressed G protein-coupled receptors
Authors: Kögler Lisa Maria , Stichel Jan , Beck-Sickinger Annette G.
Published: September 2019

G protein-coupled receptors (GPCRs) are of great pharmaceutical interest and about 35% of the commercial drugs target these proteins. Still there is huge potential left in finding molecules that target new GPCRs or that modulate GPCRs differentially. For a rational drug design, it is important to understand the structure, binding and activation of the protein of interest. Structural investigations of GPCRs remain challenging, although huge progress has been made in the last 20 years, especially in the generation of crystal structures of GPCRs. This is mostly caused by issues with the expression yield, purity or labeling. Cell-free protein synthesis (CFPS) is an efficient alternative for recombinant expression systems that can potentially address many of these problems. In this article the use of CFPS for structural investigations of GPCRs is reviewed. We compare different CFPS systems, including the cellular basis and reaction configurations, and strategies for an efficient solubilization. Next, we highlight recent advances in the structural investigation of cell-free expressed GPCRs, with special emphasis on the role of photo-crosslinking approaches to investigate ligand binding sites on GPCRs.
Developing Reflective Thinking through Poetry Writing: Views from Students and Educators
Authors: Jack Kirsten , Illingworth Sam
Published: September 2019

Aims and Objectives To explore student nurse and educator perspectives on the use of poetry writing as a way to reflect on important nursing practice issues. Background Reflective practice is a well-established method of learning in pre-registration nurse education although student nurses can find reflection a challenging process. Design An exploratory descriptive approach. Methods Data were extracted from unstructured interviews with students and educators (n = 12) from one university in the North-West region of England, United Kingdom (UK). Data were thematically analysed. Results Poetry writing supports a meaningful exploration of events, which have the potential to lead to changes in perspective. Careful planning of the poetry writing process is required, to ensure the potential of this approach is realised. Conclusion Poetry writing is an effective way to reflect on clinical practice. This work has relevance and transferability to a wide range of professional disciplines, where reflective practice is encouraged.
Reflecting on Leadership Development through Community Based Participatory Action Research
Authors: Asirifi Mary Asor
Published: September 2019

The need for leadership in nursing is well-documented and Domain Six of the doctoral section of the National Nursing Education Framework of the Canadian Association of Schools of Nursing (CASN) is Leadership. While there are likely many paths to achievement of these leadership components, the intent of this paper is to share my journey through iteration of and reflection on my PhD dissertation research focused on a four-cycle community-based participatory action research study (CBPR) related to clinical teaching in Ghana. The focus of CBPR is to engage the researcher and the participant group (community) in collaborative, and egalitarian processes to assess and problem solve an issue in the community. Similarly, leadership promotes collaborative interpersonal relationships among leaders and followers to address issues and institutes change strategies in policies. This paper presents my experiences in building leadership capacity through this scholarly endeavor (PhD thesis) in relation to the CASN guideline.
Enhanced Twitter Sentiment Analysis Using Hybrid Approach and by Accounting Local Contextual Semantic
Authors: Gupta Itisha , Joshi Nisheeth
Published: September 2019

This paper addresses the problem of Twitter sentiment analysis through a hybrid approach in which SentiWordNet (SWN)-based feature vector acts as input to the classification model Support Vector Machine. Our main focus is to handle lexical modifier negation during SWN score calculation for the improvement of classification performance. Thus, we present naive and novel shift approach in which negation acts as both sentiment-bearing word and modifier, and then we shift the score of words from SWN based on their contextual semantic, inferred from neighbouring words. Additionally, we augment negation accounting procedure with a few heuristics for handling the cases in which negation presence does not necessarily mean negation. Experimental results show that the contextual-based SWN feature vector obtained through shift polarity approach alone led to an improved Twitter sentiment analysis system that outperforms the traditional reverse polarity approach by 2–6%. We validate the effectiveness of our hybrid approach considering negation on benchmark Twitter corpus from SemEval-2013 Task 2 competition.
Mechanical characterization and machining performance evaluation of rice husk/epoxy an agricultural waste based composite material
Authors: Jain Naman , Somvanshi Kritika Singh , Gope Prakash Chandra , Singh V. K.
Published: September 2019

Natural fibers from agricultural waste have received more attraction than traditional synthetic fibers in recent years. In present investigation epoxy/rice husk composite has been fabricated to utilize the agricultural waste which can be recycled easily and overcome the pollution problems due to smoke and fine silica ash. Study of interfacial bonding and dispersion of rice husk in epoxy resin has been studied through scanning electron microscope image. Characterization of fabricated composites has been done by mechanical properties. Ultimate tensile strength, Young’s Modulus and hardness are highest at 10 wt.% of rice husk particle and their values are 66.5 MPa, 616.46 MPa and 16.8 HV respectively. Machinability of epoxy/rice husk composites has been determined through drilling operation. Effect of feed rate (0.1, 0.2 and 0.3 mm/rev), speed (300, 600 and 900 rpm) and wt.% of reinforcement (10, 15 & 20) have been studied on machinability of epoxy/rice husk composites. Taguchi L27orthogonal array has been applied to conduct the experiments to evaluate the performance characteristics viz thrust force and torque. Weight percentage was found the most significant factor for machinability followed by feed rate and speed.
The non-commuting graph of a non-central hypergroup
Authors: Iranmanesh Mahdiyeh , Jafarpour Morteza , Cristea Irina
Published: September 2019

The aim of this paper is to construct and study the properties of a certain graph associated with a non-central hypergroup, i.e. a hypergroup having non-commutative the associated fundamental group. The method of the construction of the graph is similar to that one proposed by Paul Erdős, when he defined a graph associated with a non-commutative group. We establish necessary and /or sufficient conditions for the associated graph to be Hamiltonian or planar.
Evaluation of surgical site infection in mini-invasive urological surgery
Authors: de Vermandois Jacopo Adolfo Rossi , Cochetti Giovanni , Zingaro Michele Del , Santoro Alberto , Panciarola Mattia , Boni Andrea , Marsico Matteo , Gaudio Gianluca , Paladini Alessio , Guiggi Paolo , Cirocchi Roberto , Mearini Ettore
Published: September 2019

Surgical Site Infection (SSI) is the most frequent source of infection in surgical patients and the second most frequent cause of hospital-acquired infection. The primary aim of this prospective study was to compare SSI occurrences between minimally invasive surgery (MIS) and open urological surgery. Secondly, perioperative outcomes were evaluated in two different approaches.

A consecutive group of 60 patients undergoing urological surgery were prospectively enrolled in a single high-volume center between May and October 2018. We included procedures that were performed by minimally invasive or traditional techniques. We evaluated and compared the incidence of SSI and perioperative outcomes in terms of intraoperative bleeding, post-operative complications, postoperative pain, patient satisfaction with the analgesic treatment, time to flatus, time of oral intake and mobilization, and length of hospital stay. The two groups were homogeneous with regard to demographic data.

Superficial incisional SSIs were diagnosed in 10% of cases (3/30) in the second group and 0% in the first (p<0.05); space/organ SSIs developed in 4 patients, which were diagnosed by ultrasound scan and confirmed by abdominal CT: 1 patient (3.3%) in group 1 showed an infected lymphocele, whereas 1 case of infected lymphocele and 2 cases of pelvic abscess were detected in group 2 (10%, p<0.05). All the perioperative outcomes as well as were overall complication rate favored MIS (p<0.05). The use of minimally invasive techniques in urological surgery reduced the risk of SSI by comparison with a traditional approach. In addition, MIS was associated with better perioperative outcomes and a lower overall complication rate.
Optical force microscopy: combining light with atomic force microscopy for nanomaterial identification
Authors: Jahan Nusrat , Wang Hanwei , Zhao Shensheng , Dutta Arkajit , Huang Hsuan-Kai , Zhao Yang , Chen Yun-Sheng
Published: September 2019

Scanning probe techniques have evolved significantly in recent years to detect surface morphology of materials down to subnanometer resolution, but without revealing spectroscopic information. In this review, we discuss recent advances in scanning probe techniques that capitalize on light-induced forces for studying nanomaterials down to molecular specificities with nanometer spatial resolution.
Crystal structure of tetraaqua-bis(μ2-5-aminoisophthalato-κ3
N:O,O′)-bis(4,4′-dipyridylsulfide-κ1
N)dizinc(II), C36H34N6O12S2Ni2
Authors: Chang Xin-Hong , Zhai Zhi-Min , Lu Xiao-Min
Published: September 2019

C36H34N6O12S2Ni2, monoclinic, C2/c (no. 15), a = 29.642(4) Å, b = 6.2241(4) Å, c = 21.667(2) Å, β = 108.592(13)°, V = 3788.9(7) Å3, Z = 4, R
gt(F) = 0.0907, wR
ref(F
2) = 0.1605, T = 293(2) K.
Barrel heating with inductive coils in an injection molding machine
Authors: Nian Shih-Chih , Yeh Gao-Hao , Huang Ming-Shyan
Published: September 2019

Traditional injection molding machines use resistance heating (RH) bands to heat the barrel. However, RH has a low energy rate; thus, the time required to reach the target temperature is rather long. Consequently, the use of inductive techniques, with a faster heating rate and improved energy rate, has attracted growing interest in recent years. However, an inappropriate design of the inductive coils and plasticization barrel may result in a strong repulsive magnetic field between neighboring coils and a corresponding reduction in the heating performance. Thus, developing an appropriate inductive heating design is essential in improving the barrel heating performance. The present study therefore performed a simulation and experimental investigation into the magnetic field and temperature distribution for different barrel geometries and coil current designs. The simulation results showed that the application of spiral grooves to the barrel improved both the heating rate and the temperature uniformity (TU) and effectively solved the proximity effect. The results indicated that the application of induction heating together with a novel grooved barrel design yields an effective improvement in both the thermal efficiency and the TU compared to that achieved using the traditional RH method with a single- or double-section barrel.
Determining wildland fire markers in residential structures using thermal desorption gas chromatography mass spectrometry
Authors: Martin M. Katie , LeCaptain Dale J. , Delia Alice
Published: September 2019

Each year thousands of wildland fires blaze across the United States causing secondary (“smoke”) damage to numerous businesses and personal property. Currently there are no specific industry standards or guidelines for determining wildfire combustion residues. Remediation decisions often rely on anecdotal evidence from occupants. A variety of particulate methods are used to assess surface contamination but there are few methods for evaluating organic chemical residues that encompass the wide range of chemical classes produced during wildland fires. A new method was developed employing a thermal desorption gas chromatography mass spectrometry (TD-GCMS). TD-GCMS using novel sorbent beds decreases the sample preparation substantially and enables sampling of bulk materials by off-gassing. Furthermore, the method developed is specific to wildland fire events. Results from a simulated wildland fire event are also provided.
Alpine rock art: then and now, and into the future?
Authors: Chippindale Christopher
Published: September 2019

Rock art in the Alps, centred on just two expansive sites, complements the many Scandinavian sites as a major source for open-air art in later European prehistory. A revelatory biography of one of the pioneering researchers there, published simultaneously with a superb monograph on a single rich surface of Alpine art, prompts this review of how we have studied, how we presently study and how we may come to study that art.