bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Different Atrial Conduction Velocity Estimation Algorithms Improves with Knowledge about the Depolarization Pattern
Authors: Nagel Claudia , Pilia Nicolas , Unger Laura , Dössel Olaf 
Published: September 2019

Abstract
Quantifying the atrial conduction velocity (CV) reveals important information for targeting critical arrhythmia sites that initiate and sustain abnormal electrical pathways, e.g. during atrial flutter. The knowledge about the local CV distribution on the atrial surface thus enhances clinical catheter ablation procedures by localizing pathological propagation paths to be eliminated during the intervention. Several algorithms have been proposed for estimating the CV. All of them are solely based on the local activation times calculated from electroanatomical mapping data. They deliver false values for the CV if applied to regions near scars or wave collisions. We propose an extension to all approaches by including a distinct preprocessing step. Thereby, we first identify scars and wave front collisions and provide this information for the CV estimation algorithm. In addition, we provide reliable CV values even in the presence of noise. We compared the performance of the Triangulation, the Polynomial Fit and the Radial Basis Functions approach with and without the inclusion of the aforementioned preprocessing step. The evaluation was based on different activation patterns simulated on a 2D synthetic triangular mesh with different levels of noise added. The results of this study demonstrate that the accuracy of the estimated CV does improve when knowledge about the depolarization pattern is included. Over all investigated test cases, the reduction of the mean velocity error quantified to at least 25 mm/s for the Radial Basis Functions, 14 mm/s for the Polynomial Fit and 14 mm/s for the Triangulation approach compared to their respective implementations without the preprocessing step. Given the present results, this novel approach can contribute to a more accurate and reliable CV estimation in a clinical setting and thus improve the success of radio-frequency ablation to treat cardiac arrhythmias.
3D Printed Anatomical Model of a Rat for Medical Imaging
Authors: Exner Miriam , Szwargulski Patryk , Knopp Tobias , Graeser Matthias , Ludewig Peter 
Published: September 2019

Abstract
For medical research, approximately 115 million animals are needed every year. Rodents are used to test possible applications and procedures for the diagnosis of anatomical and physiological diseases. However, working with living animals increases the complexity of an experiment. Accurate experimental planning is essential in order to fulfill the 3R rules (replace, reduce and refine). Especially in tracer-based imaging modalities, such as magnetic particle imaging (MPI), where only nanoparticles give a positive contrast, the anatomical structure of the rodent is not visible without co-registration with another imaging modality. This leads to problems in the experimental planning, as parameters, such as field of view, rodent position and tracer concentration, have to be determined without visual feedback. In this work, a 3D CAD rat model is presented, which can be used to improve the experiment planning and thus reduce the number of animals required. It was determined using an anatomy atlas and 3D printed with stereolithography. The resulting model contains the most important organs and vessels as hollow cavities. By filling these with appropriate tracer materials, the phantom can be used in different imaging modalities such as MPI, magnetic resonance imaging (MRI) or computed tomography (CT). In a first MPI measurement, the phantom was filled with superparamagnetic nanoparticles. Finally, a successful visualization of all organs and vessels of the phantom was possible. This enables the planning of the experiment and the optimization of experimental parameters for a region of interest, where certain organs in a living animal are localized.
Mobile System for the Prevention, Diagnosis, and Personalized Treatment of Neck Pain Under a Patient’s Everyday Life Circumstances
Authors: Tadayon Puian , Felderhoff Thomas , Staude Gerhard , Knopp Andreas 
Published: September 2019

Abstract
This work presents a new system concept for the prevention, diagnosis and interactive treatment of neck pain. It comprises two measurement units worn at the head and the torso, a smartphone/tablet and a medical assistance software. The system aims to provide mobile measurement of full neck movement including rotatory and translatory movements under a patients everyday life circumstances. Multiple features including biofeedback and therapy exercises are intended to be individually configurable according to the specific medical indications of the patient. In addition to the system concept the current implementation state comprising the two measurement units and a visualization app running on a tablet is presented.
Development and Validation of Bone Models using Structural Dynamic Measurement Methods
Authors: Neupetsch Constanze , Hensel Eric , Werner Michael , Meißner Sven , Troge Jan , Drossel Welf-Guntram , Rotsch Christian 
Published: September 2019

Abstract
Vibration measurement and signal analysis methods are common to evaluate the functionality and characteristics of technical components in different industrial and scientific areas. Modal analysis for example is a standard method to characterize the dynamic behavior of a structure and enables the development of validated bone models. The state of the art of analyzing bone structures does not include the modal damping, although it has a significant influence on the dynamic characteristics. Within the presented investigations, the modal analyses have been performed contactless with respect to excitation and response acquisition, which implies that there are no influences of shakers or sensor couplings. Therefore, an automatic impulse hammer and a 3D Scanning Laser Doppler Vibrometer were used for excitation and response detection. Various supports of the test specimens, surface pretreatments, excitation points and excitation impulses were examined to optimize the measurement setup and process. Experimental modal analysis data were analyzed by curve fitting methods to determine the modal parameters. To evaluate different structures and effects of damping, 3D printed artificial bones and animal in vitro bones were used to perform the measurements. To produce the cortical layer of the artificial bone models, volume models were generated based on medical image data and printed by polyamide-based selective laser sintering. The cancellous bone was represented by different foam fillings for the artificial bones. Thereby, the variation of the porosity was achieved by using different mixing ratios of polyurethane foam and hardener. Furthermore, the modal damping parameters were determined from the measurement of animal bones. The measurement time was optimized during the practical implementation of the parameter determination to minimize the influence of drying and decomposition processes on the measurement results.
Feasibility test of Dynamic Cooling for detection of small tumors in IR thermographic breast imaging
Authors: Sadeghi Maryam , Boese Axel , Maldonado Ivan , Friebe Michael , Sauerhering Joerg , Schlosser Simon , Wehberg Heinrich , Wehberg Konrad 
Published: September 2019

Abstract
Thermographic imaging is a known technology to detect temperature differences. For medical applications, the patterns of heat distribution are used for diagnosis. It is already tested to visualize blood supply, inflammatory processes, and superficial or more extensive tumors, e.g. in the breast tissue. This method was promoted for breast screening purposes and as a substitute for mammography for mid aged women, but the results were not convincing for younger women, where tissue density is higher, tumor growth is often connected to local temperature increase and radiation-based mammography is not an option. Infrared (IR) thermography can support tumor screening. The screening should allow the early detection of small lesions even in the depth. Therefor we evaluated the feasibility of dynamic cooling in combination with IR imaging in a phantom study. A temperature-controllable gel phantom including a heating plate, a depth-adjustable heat source mimicking a tumor, and three sensors for temperature monitoring was built up. A raspberry pi device serves as a control unit to create a stable temperature balance comparable to a human breast. For the experiments, the tumor was placed in various depth. After cooling, the thermal recovery phase of the phantom was imaged using an IR camera and a webcam. A pixel-wise analysis of the IR data detects a higher gradient of temperature change in the tumor region. The experiments demonstrated the feasibility of tumor detection based on dynamic cooling and IR imaging.
Predicting Surgical Phases using CNN-NARX Neural Network
Authors: Jalal Nour Aldeen , Alshirbaji Tamer Abdulbaki , Möller Knut 
Published: September 2019

Abstract
Online recognition of surgical phases is essential to develop systems able to effectively conceive the workflow and provide relevant information to surgical staff during surgical procedures. These systems, known as context-aware system (CAS), are designed to assist surgeons, improve scheduling efficiency of operating rooms (ORs) and surgical team and promote a comprehensive perception and awareness of the OR. State-of-the-art studies for recognizing surgical phases have made use of data from different sources such as videos or binary usage signals from surgical tools. In this work, we propose a deep learning pipeline, namely a convolutional neural network (CNN) and a nonlinear autoregressive network with exogenous inputs (NARX), designed to predict surgical phases from laparoscopic videos. A convolutional neural network (CNN) is used to perform the tool classification task by automatically learning visual features from laparoscopic videos. The output of the CNN, which represents binary usage signals of surgical tools, is provided to a NARX neural network that performs a multistep-ahead predictions of surgical phases. Surgical phase prediction performance of the proposed pipeline was evaluated on a dataset of 80 cholecystectomy videos (Cholec80 dataset). Results show that the NARX model provides a good modelling of the temporal dependencies between surgical phases. However, more input signals are needed to improve the recognition accuracy.
Biocompatibility of magnetic iron oxide nanoparticles for biomedical applications
Authors: Matschegewski Claudia , Kowalski Anja , Müller Knut , Teller Henrik , Grabow Niels , Großmann Swen , Schmitz Klaus-Peter , Siewert Stefan 
Published: September 2019

Abstract
Magnetic nanoparticles are highly promising for the usage in various biomedical applications including magnetic particle imaging (MPI), cancer hyperthermia treatment or as drug carriers. The present study aims at assessing in vitro biocompatibility of two commercially available magnetic iron oxide nanoparticle formulations: dextran-based magnetic nanoparticle synomag-D and bionized nanoferrite BNF-starch. Biological performance of both nanoparticle formulations were studied in human endothelial cells by analyzing cell viability and nanoparticle internalization in order to judge their suitability as theranostics.
A Multistep Legendre Pseudo-Spectral Method for Nonlinear Volterra Integral Equations
Authors: Xiao-Yong Zhang , Jun-Lin Li 
Published: September 2019

Abstract
In this paper, we extend the single-step pseudo-spectral method for nonlinear Volterra integral equations of the second kind to the multistep pseudo-spectral method. We also analyze the convergence of the hp-version of the multistep pseudo-spectral method under the L
2-norm, and the result shows that the scheme enjoys high order accuracy and can be implemented in a stable and efficient manner. In addition, it is very suitable for long time calculations and large step size situations. Numerical experiments confirm the theoretical expectations.
Proton internal pressure distribution suggests a simple proton structure
Authors: Vayenas Constantinos G. , Grigoriou Dimitrios , Martino Eftychia 
Published: September 2019

AbstractUnderstanding the origin of quark confinement in hadrons remains one of the most challenging problems in modern physics. Recently, the pressure distribution inside the proton was measured via deeply virtual Compton scattering. Surprisingly, strong repulsive pressure up to 1035 pascals, the highest so far measured in our universe, was obtained near the center of the proton up to 0.6 fm, combined with strong binding energy at larger distances. We show here that this profile can be derived semiquantitatively without any adjustable parameters using the rotating lepton model of composite particles (RLM), i.e. a proton structure comprising a ring of three gravitationally attracting rotating ultrarelativistic quarks. The RLM synthesizes Newton’s gravitational law, Einstein’s special relativity, and the de Broglie’s wavelength expression, thereby conforming with quantum mechanics, and also yields a simple analytical formula for the proton radius and for the maximum measured pressure which are in excellent agreement with the experimental values.
Confinement effect of different arrangements of transverse reinforcement on axially loaded concrete columns: An experimental study
Authors: Domenico Dario De , Falliano Devid , Ricciardi Giuseppe 
Published: September 2019

AbstractConcrete behaves as a brittle material due to its low inherent tensile strength, but it can also exhibit a markedly ductile behavior when coupled with transverse reinforcement like steel stirrups. The role of stirrups is to enhance confinement effect, to restrain the lateral expansion of concrete, thus modifying the concrete stress-strain constitutive law and enabling higher compression strains and higher ductility. This paper focuses on the confinement effect induced by different arrangements of transverse reinforcement on axially loaded concrete columns. An experimental campaign has been carried out, comprising 18 concrete columns with two different mechanical strengths and reinforced with three different layouts of stirrups, namely typical closed square hoops, closed stirrups with additional cross ties, and a novel type of stirrups involving rectangular hoops with additional restraint plates, the latter offering an enhanced diffused confinement action and limiting extensive spalling of the cover concrete. Formation and propagation of longitudinal micro-cracks are reduced with the novel type of diffused stirrups and a moderate-to-high increase of ductility is observed. However, the beneficial effects induced by diffused stirrups are more pronounced in medium-strength concrete and almost negligible in low-strength concrete that collapses due to a brittle cracking failure without involving the confinement action of the transverse reinforcement.
Lie symmetry analysis and conservation law for the equation arising from higher order Broer-Kaup equation
Authors: Wang Hengtai , Chen Huiwen , Ouyang Zigen , Li Fubin 
Published: September 2019

Abstract
In this paper, Lie symmetry analysis is performed for the equation derived from $(2+1)$-dimensional higher order Broer-Kaup equation. Meanwhile, the optimal system and similarity reductions based on the Lie group method are obtained. Furthermore, the conservation law is studied via the Ibragimov’s method.
Positive solutions of the discrete Dirichlet problem involving the mean curvature operator
Authors: Ling Jiaoxiu , Zhou Zhan 
Published: September 2019

Abstract
In this paper, by using critical point theory, we obtain some sufficient conditions on the existence of infinitely many positive solutions of the discrete Dirichlet problem involving the mean curvature operator. We show that the suitable oscillating behavior of the nonlinear term near at the origin and at infinity will lead to the existence of a sequence of pairwise distinct nontrivial positive solutions. We also give two examples to illustrate our main results.
The factors affecting early death in newly diagnosed APL patients
Authors: Ciftciler Rafiye , Haznedaroglu Ibrahim Celalettin , Aksu Salih , Ozcebe Osman , Sayınalp Nilgun , Malkan Umit Yavuz , Buyukasık Yahya 
Published: September 2019

Abstract

Background and aim
In the past, acute promyelocytic leukemia (APL) was considered as one of the most rapidly lethal form of acute myeloid leukemia (AML). The objective of this study was to assess clinical parameters affecting early death (ED) in patients with APL.

Materials and methods
Forty-three patients with APL who were diagnosed at Hacettepe University Hospital between the years of 2005 and 2018 were evaluated.

Results
In univariate analyses, presentation with hemorrhage, DIC or infection at diagnosis, ECOG performance score, blast percentage on bone marrow, Sanz score, leukocyte, thrombocyte, fibrinogen and LDH levels were found to be statistically significantly different between patients with ER and patients without ED. In multivariate analysis, presentation with hemorrhage, DIC or infection at diagnosis, ECOG performance score, blast percentage on bone marrow, Sanz score, leukocyte, thrombocyte, fibrinogen, and LDH levels were found to be independent factors that are related with higher rate of ED in 30 days after treatment.

Conclusion
Induction chemotherapy should be started as soon as possible after diagnosis of APL. Improving ED rates may become the greatest challenge for the future treatment of the diseases.
Beta Frequency Oscillations in the Subthalamic Nucleus Are Not Sufficient for the Development of Symptoms of Parkinsonian Bradykinesia/Akinesia in Rats
Authors: Swan Christina Behrend , Schulte Derek J. , Brocker David T. , Grill Warren M. 
Published: September 2019

AbstractSubstantial correlative evidence links the synchronized, oscillatory patterns of neural activity that emerge in Parkinson’s disease (PD) in the beta (β) frequency range (13–30 Hz) with bradykinesia in PD. However, conflicting evidence exists, and whether these changes in neural activity are causal of motor symptoms in PD remains unclear. We tested the hypothesis that the synchronized β oscillations that emerge in PD are causal of symptoms of bradykinesia/akinesia. We designed patterns of stimulation that mimicked the temporal characteristics of single unit β bursting activity seen in PD animals and humans. We applied these β-patterned stimulation patterns along with continuous low-frequency and high-frequency controls to the subthalamic nucleus (STN) of intact and 6-OHDA-lesioned female Long–Evans and Sprague-Dawley rats. β-Patterned paradigms were superior to low-frequency controls at induction of β power in downstream substantia nigra reticulata (SNr) neurons and in ipsilateral motor cortex. However, we did not detect deleterious effects on motor performance across a wide battery of validated behavioral tasks. Our results suggest that β frequency oscillations (BFOs) may not be sufficient for the generation of bradykinesia/akinesia in PD.
Effects of a prevention intervention concerning screens, and video games in middle-school students: Influences on beliefs and use
Authors: Bonnaire Céline , Serehen Zéphyr , Phan Olivier 
Published: September 2019

Background and aims
The aim of this study was to evaluate the effects of a prevention intervention on French adolescents’ Internet and video games use and on their beliefs concerning gaming and Internet Gaming Disorder (IGD), in order to adjust prevention programs further.

Methods
The study comprised a prevention intervention group (PIG) and a control group assessed at three times – baseline, post-test, and 4-month follow-up. At baseline, a total of 434 junior high adolescents from five secondary schools were assessed (Mage = 13.2 years; SD = 0.5). The main outcome measures were adolescents’ gaming and Internet use (amount of time spent during the week and the weekend), the number of adolescents with IGD, and beliefs about gaming and IGD.

Results
The results showed significant effects of the prevention intervention on Internet and gaming use (at T2, time spent was significantly lower in the PIG), an important increase of IGD prevalence between baseline and follow-up in the control group, and decreased rates of IGD among adolescents in the PIG between post-intervention and follow-up. Between baseline and follow-up, the control group showed a more significant increase of minutes per day during the week and the weekend on Internet versus during the week on video games. The impact of the prevention intervention on adolescents’ beliefs varied according to gender. Girls had a better understanding generally of the potential dangers of and reasons for IGD.

Discussion
Implications for future research and prevention approaches are discussed in this study.
Staphylococcus által kiváltott, immunglobulin-E-alapú anafilaxiás reakciók Crohn-betegségben. Egy tünetegyüttes első leírása
Authors: Zöld Éva , Barta Zsolt , Török Miklós , Soltész Pál , Szegedi Andrea , Sipka Sándor 
Published: September 2019

Abstract: Immunglobulin E (IgE)-based, irregularly recurring, severe anaphylactic reactions occurred in a 50-year-old European white male patient suffering also from Crohn’s disease. On the base of immunologic laboratory tests concerning the mechanism of the phenomenon, the idea arose whether molecules derived for certain microbial derivatives could enter the blood circulation via the damaged bowel walls in the patient with Crohn’s disease and they might act as allergens. The microbial analysis diagnosed atypical Staphylococcus in the stool. The serum level of IgE was very high. The concomitant use of targeted antibiotics and anti-allergy and immunosuppressive agents resulted in a complete remission during a couple of months. Not only Crohn’s disease has improved, but also the total serum IgE level has decreased significantly, and the unpredictable anaphylactic attacks have been completely eliminated. In Crohn’s disease, the anaphylactic complications induced by atypical microbial allergens (e.g., derivatives of Staphylococcus) can be effectively treated after the recognition of this pathological mechanism. This is the first description of such a pathologic state. Orv Hetil. 2019; 160(38): 1514–1518.
Epehólyag-agenesia. Epekövességet utánzó ritka rendellenesség egy felnőtt nőben
Authors: Molnar Călin , Sárközi Tibor , Kwizera Cedric , Botoncea Marian , Zeno Opriș , Petrișor Marius , Grigorescu Bianca Liana 
Published: September 2019

Abstract: Gallbladder agenesis is a rare congenital malformation due to an embryological defect of the biliary system. In most cases it is asymptomatic, but it can also mimic biliary colic. We report the case of a 72-year-old Caucasian woman with a medical history of cardiovascular disease and hypercholesterolemia, under cholesterol-lowering and hypotensive treatment, who presented symptoms suggesting biliary colic. She underwent laparoscopic surgery that confirmed the final diagnosis. We present our approach in this rare case as well as a brief review of medical literature. The surgeon should decide intraoperatively whether to continue and search for a possible ectopic gallbladder or investigate further with imaging studies. Gallbladder agenesis is a rare condition that the surgeon must be aware of. In the cases of inconclusive or indirect signs of cholelithiasis, the best approach is complementary imaging investigations such as magnetic resonance cholangiopancreatography in order to avoid surgery. Orv Hetil. 2019; 160(38): 1510–1513.