bluuebunny/crossref_metadata_2025 huggingface dataset:
Native Aortic and Tricuspid Valve Endocarditis Complicated by Embolic ST Elevation Myocardial Infarction
Authors: Zaman Mumtaz , Loynd Richard , Donato Anthony
Published: March 2019

Acute myocardial infarction due to a coronary embolic event can occur as a complication of infective endocarditis in up to 2.9% of cases and can frequently be the presenting symptom. A 35-year-old female presented with 4 hours of typical chest pain and was found to have ST elevations in inferior leads as well as an elevated serum Troponin I of 8.29 ng/ml (normal: <0.06 ng/ml). Urgent cardiac catheterization revealed total occlusion of the right coronary artery without other coronary disease or collaterals. Following a failed attempt at thrombus extraction, a 3.0×38 mm bioabsorbable drug-eluting stent was placed. Echocardiography then revealed large mobile aortic valve vegetations with the largest measuring 1.4×1.7 cm, severe tricuspid regurgitation with a 1.1×0.5 cm mobile vegetation on the anterior leaflet along with a patent foramen ovale with right-to-left shunting. Blood cultures identified Enterococcus faecalis in 4 of 4 vials. The patient underwent urgent replacement of tricuspid and aortic valves as well as 6 weeks of IV antibiotics followed by chronic antibiotic suppression.
Predictors of Effectiveness of Glucagon-Like Peptide-1 Receptor Agonist Therapy in Patients with Type 2 Diabetes and Obesity
Authors: Babenko Alina Yu. , Savitskaya Daria A. , Kononova Yulia A. , Trofimova Aleksandra Yu. , Simanenkova Anna V. , Vasilyeva Elena Yu. , Shlyakhto Evgeny V.
Published: March 2019

Rationale. It is well known that diabetes mellitus (DM) exacerbates the mechanisms underlying atherosclerosis. Currently, glucagon-like peptide-1 receptor agonists (aGLP-1) have one of the most prominent cardioprotective effects among the antidiabetic agents. However, the treatment with aGLP-1 is effective only in 50-70% of the cases. Taking into account the high cost of these medications, discovery of the predictors of optimal response to treatment is required. Purpose. To identify the predictors of the greater impact of aGLP-1 on HbA1c levels, weight reduction, and improvement in lipid profile. Methods. The study group consisted of 40 patients with type 2 DM (T2DM) and obesity who were treated with aGLP-1. The follow-up period was 24 weeks. Patients’ evaluation was conducted at baseline and after 24 weeks. In addition, it included the assessment of the hormones involved in glucose and lipid metabolism and appetite regulation. Results. Patients who have initially higher BMI (body mass index), glycemia, and triglycerides (TG) had better improvement in these parameters undergoing aGLP-1 treatment. In patients with a BMI loss≥5%, GLP-1 and fasting ghrelin levels were higher and ghrelin level in postnutritional status was lower. The HbA1c levels decreased more intensively in participants with higher GLP-1 levels. TG responders had lower baseline fasting glucose-dependent insulinotropic peptide (GIP) and postprandial ghrelin levels. Conclusion. The evaluation of the glycemic control, lipid profile, and GLP-1, GIP, and ghrelin levels are useable for estimating the expected efficacy of aGLP-1.
Ship-SIBISCaS: A First Step towards the Identification of Potential Maritime Law Infringements by means of LSA-Based Image
Authors: León-Paredes Gabriel Alejandro , Barbosa-Santillán Liliana Ibeth , Sánchez-Escobar Juan Jaime , Pareja-Lora Antonio
Published: March 2019

Maritime safety and security are being constantly jeopardized. Therefore, identifying maritime flow irregularities (semi-)automatically may be crucial to ensure maritime security in the future. This paper presents a Ship Semantic Information-Based, Image Similarity Calculation System (Ship-SIBISCaS), which constitutes a first step towards the automatic identification of this kind of maritime irregularities. In particular, the main goal of Ship-SIBISCaS is to automatically identify the type of ship depicted in a given image (such as abandoned, cargo, container, hospital, passenger, pirate, submersible, three-decker, or warship) and, thus, classify it accordingly. This classification is achieved in Ship-SIBISCaS by finding out the similarity of the ship image and/or description with other ship images and descriptions included in its knowledge base. This similarity is calculated by means of an LSA algorithm implementation that is run on a parallel architecture consisting of CPUs and GPUs (i.e., a heterogeneous system). This implementation of the LSA algorithm has been trained with a collection of texts, extracted from Wikipedia, that associate some semantic information to ImageNet ship images. Thanks to its parallel architecture, the indexing process of this image retrieval system has been accelerated 10 times (for the 1261 ships included in ImageNet). The range of the precision of the image similarity method is 46% to 92% with 100% recall (that is, a 100% coverage of the database).
Compatibilizer Polarity Parameters as Tools for Predicting Organoclay Dispersion in Polyolefin Nanocomposites
Authors: Weltrowski Marek , Dolez Patricia I.
Published: March 2019

Nanocomposites give an innovative method to increase the mechanical, thermal, and barrier performance of polymers. However, properly dispersing the nanoparticles in the polymer matrix is often key in achieving high performance, especially in the case of hydrophilic nanoparticles and hydrophobic polymers. For that purpose, nanoparticles may be functionalized with organic groups to increase their affinity with the polymer matrix. Compatibilizing agents may also be included in the nanocomposite formulation. This paper aims at identifying parameters relative to the compatibilizer polarity that would allow predicting nanoparticle dispersion in the polymer nanocomposite. The analysis used published data on nanocomposite samples combining clay nanoparticles, polyolefins, and various compatibilizing agents. We studied the correlations between the nanoclay exfoliation ratio and five different parameters describing the compatibilizer hydrophilic-lipophilic balance: the acid value, the mole, and weight fraction of polar groups, the number of polymer chain units per polar group, and the number of moles of polar groups per mole of compatibilizer. The best correlation was observed with the number of polymer chain units per polar group in the compatibilizer. This parameter could be used as a tool to predict the dispersion of organoclay nanoparticles in polyolefins. Another important result of the study is that, among the compatibilizers investigated, those with a low acid value provided a better nanoclay exfoliation compared to those with a high acid value. This may indicate the existence of a maximum in the nanoclay exfoliation/compatibilizer polarity curve, which would open new perspectives for nanocomposite performance optimization.
Development of Bright Fluorescent Poly(1-vinyl-2-pyrrolidone-co-acrylonitrile) and Its Polysalts with HCl and HNO3: Materials for Solid State Electrical Applications
Authors: Upadhyaya Samiran , Sarma Rajumani , Barik Abdul , Sen Sarma Neelotpal
Published: March 2019

Herein, we have reported the synthesis, characterization, and ionic conductivity analysis of fluorescent poly(1-vinyl-2-pyrrolidone-co-acrylonitrile) and its salts with 10% HCl and HNO3 in solid state. The synthesized polymers and their polysalts were characterized using Fourier-transformed infrared spectroscopy, UV-visible, Cyclic Voltammetry, Thermogravimetric analysis, Differential Scanning Calorimetric, X-ray diffraction, and spectrofluorometric techniques. The AC conductivities were measured in the frequency ranging from 42 Hz to 1 MHz and temperature from 30°C to 70°C in solid state. Ionic conductivities of the salts of the copolymer with hydrochloric acid and nitric acid were found to be 2.145×10−5 and 2.349×10−5 S cm −1, respectively, which are nearly 1000 times more than that of poly(1-vinyl-2-pyrrolidone-co-acrylonitrile). The activation energies for the copolymer and the polyelectrolytes were found to be 0.454, 0.6288, and 0.659 eV, respectively. The transport number of the copolymers was found to be 0.0278, and that of the polysalts was found to be 0.7596 and 0.7424, respectively. The copolymer showed distinct fluorescent when irradiated with UV light and can be used as acid vapor sensor in solid state.
Optical Model of Laminated Remote Phosphor Films and Its Application in White LED
Authors: Chen Yong-Hao , Zhuo Ning-Ze , Jiang Peng , Cheng Shao-Wen , Shen Peng-Fei , Wang Hai-Bo
Published: March 2019

Based on Mie scattering and Monte Carlo ray tracing method, the transmission process of light in the remote phosphor film is described and the optical model of red and green laminated phosphor films is constructed. The photochromic properties of the phosphor films were studied by TM-30-15 method proposed by the North American Lighting Association. The investigation discloses that the normalized cross correlation of single-layer phosphor film spectral power distribution between the simulation and experimental results is about 99%, and the deviation of color coordinates is within 0.01. Based on the monochrome phosphor optical model, we establish bicolor optical model of red and green laminated phosphor film layers to form white light and can predict its color performance. The experimental results show that the normalized cross correlation of laminated phosphor film spectral power distribution between the simulation and experiment is about 97%, and the optical model of red and green laminated phosphor film can accurately predict the index Rf and Rg. When the red and green phosphor mass ratio is 0.05:0.5, the simulated color is optimal, Rf reaches 90, and Rg reaches 100, whose corresponding experimental values are Rf=90, Rg=101.
Photocatalytic Degradation of 2,4-Dichlorophenol by TiO2 Intercalated Talc Nanocomposite
Authors: Ai Manqing , Qin Wenli , Xia Tian , Ye Ying , Chen Xuegang , Zhang Pingping
Published: March 2019

Novel nanocomposites have been prepared by intercalating TiO2 nanoparticles into talc. The nanocomposites have been verified by X-ray diffraction (XRD) from the appearance of a characteristic diffraction peak of TiO2. Thermal behavior of the prepared samples is examined by thermogravimetric analyzer (TGA), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS), which have shown no TiO2 particles on the surface of the talc. The TiO2 particles are found in the layers of talc by transmission electron microscopy (TEM) and the Brunauer-Emmett-Teller (BET) method, which have shown the increase of specific surface areas and total pore volumes and the decline of average pore diameters. As the strong adsorption ability of talc can intensify the power of photon absorption and capture-recombination carriers, more than 99.5% of 2,4-dichlorophenol can be degraded in 1 h by the nanocomposite under an ultraviolet lamp in neutral solution and room temperature after reaching adsorption equilibrium, and the result of adsorbance is in accord with the first-order kinetic. The degradation rate was maintained at about 99% after 20 times. Therefore, the prepared talc/TiO2 nanocomposite is an efficient, stable, and recyclable material for wastewater treatment.
Numerical Simulation and Microscopic Stress Mechanism for the Microscopic Pore Deformation during Soil Compression
Authors: Tao Gaoliang , Peng Wan , Xiao Henglin , Wu Xiaokang , Chen Yin
Published: March 2019

Pore structure is closely related with strength, constitutive relation, consolidation characteristics, and permeability properties of soil. Consequently, improving the understanding of the relationship between microscopic structure and macroscopic physical and mechanical properties has extremely important scientific significance. A large number of studies have shown that pores of soil have fractal features, and hence, the carpet model can be used to approximately simulate the fractal structure of clay. In the present study, ANSYS software was selected to establish a microscopic model of clay to study the distribution of microscopic stress and microscopic deformation characteristics of pores under different consolidation pressures. Besides, the variation law of microscopic pore size was quantitatively determined by using IPP (Image‐Pro Plus) software. Combined with the fractal theory, the changes of microscopic pore of numerical simulation and that of physical experiment during compression of clay are studied. All the results indicated that the microscopic stress distribution of clay is not uniform on the compaction process. The larger the pore size is, the bigger the compression stress on both sides and the greater the bending deformation of upper part of the pore is, which leads to the deformation of larger pores which is bigger than that of smaller pores. Based on the results, issues about the microscopic mechanism of the difference in vertical and horizontal permeability under compression of clay, the relationship between the changes of pore shape and microscopic stress, the preliminary principle of “preferential crush of larger particles” for granular soil, skeleton stress across the region where stiffness is relative larger, and the self‐protection of particles and pores are also discussed. The results of this study are of great importance in understanding of soil compression and related physical and mechanical properties from the microscopic view.
Full-Phase Operation Transresistance-Mode Precision Full-Wave Rectifier Designs Using Single Operational Transresistance Amplifier
Authors: Chien Hung-Chun
Published: March 2019

This study proposed the designs of two full-phase operation transresistance-mode (TRM) precision full-wave rectifiers. The first circuit consisted of a single operational transresistance amplifier (OTRA), four diodes, and a resistor. The second scheme was an OTRA combined with a full metal-oxide semiconductor field-effect transistor-based design, which is preferable for integrated circuit implementation because no passive components are used in the circuit topology. Based on our literature review, this is the first study that discussed a full-phase operation transresistance-mode precision full-wave rectifier consisting of a single OTRA and few passive components. In this paper, several previously reported precision full-wave rectifiers consisting of various active devices are first reviewed followed by the proposed OTRA-based transresistance-mode precision full-wave rectifiers and an analysis of nonideal effects. Furthermore, computer simulations and experimental results are presented to verify the validity of the proposed circuits, which were consistent with the theoretical predictions.
Design of Modified Single-Layer Double U-Type Linear to Circular Polarization Convertor
Authors: Hu Haoming , Zhou Dongfang , Chen Guohu , Li Tianpeng , Gao Jun
Published: March 2019

This paper proposes single-layer periodic arrays of freestanding slot frequency-selective surface (FSS) as an approach to convert linearly polarized wave to circularly polarized wave. The double U-type structure is etched on a metal plate rather than a traditional print circuit board (PCB) material. It has the characteristics of broadband and could be applied to the situation of large incident angles. Numerical simulations have been carried out, and the prototype structures have been fabricated and experimentally validated. The whole thickness is only 1 mm, and the results show that 3 dB axial ratio (AR) bandwidth is 36.6% at normal incident (16.5% at ±60°). An insertion loss of under 3 dB can be achieved within the whole AR bandwidth.
Numerical Investigation of Natural Convective Condensation with Noncondensable Gases in the Reactor Containment after Severe Accidents
Authors: Fu Wen , Zhang Li , Li Xiaowei , Wu Xinxin
Published: March 2019

The heat and mass transfer processes of natural convective condensation with noncondensable gases are very important for the passive containment cooling system of water cooled reactors. Numerical simulation of natural convective condensation with noncondensable gases was realized in the Fluent software by adding condensation models. The scaled AP600 containment condensation experiment was simulated to verify the numerical method. It was shown that the developed method can predict natural convective condensation with noncondensable gases well. The velocity, species, and density fields in the scaled AP600 containment were presented. The heat transfer rate distribution and the influences of the mass fraction of air on heat transfer rate were also analyzed. It is found that the driving force of natural convective condensation with noncondensable gases is mainly caused by the mass fraction difference but not temperature difference. The natural convective condensation with noncondensable gases in AP1000 containment was then simulated. The temperature, species, velocity, and heat flux distributions were obtained and analyzed. The upper head of the containment contributes to 35.1% of the total heat transfer rate, while its area only takes 25.4% of the total condensation area of the containment. The influences of the mass fraction of low molecular weight noncondensable gas (hydrogen) on the natural convective condensation were also discussed based on the detailed species, density, and velocity fields. The results show that addition of hydrogen (production of zirconium-water reaction after severe accident) will weaken the intensity of natural convection and the heat and mass transfer processes significantly. When hydrogen contributes to 50% mole fraction of the noncondensable gases, the heat transfer coefficient will be reduced to 45%.
Flexural Behavior of Hybrid Composite Beam (HCB) Bridges
Authors: Aboelseoud Mohamed A. , Myers John J.
Published: March 2019

A new hybrid composite beam (HCB) has recently been used in the construction of three bridges in Missouri, USA. HCB consists of self-consolidating concrete (SCC) that is poured into classical arch shape and tied at the ends by steel tendons. Both the concrete and the steel are tucked inside a durable fiberglass shell, and the voids are filled with polyiso foam. This paper aims to examine the flexural behavior of an in-service HCB, evaluate the current methodology and assumptions, and propose modifications to that methodology. To achieve these goals, the strains induced in HCB elements due to different loading stages were experimentally measured. Numerical predictions of the strains were performed via the existing methodology, the modified procedure, and a finite element model (FEM) that was constructed using ANSYS V14. The linear FEM predicted the strains with acceptable accuracy. The model clarified that the foam achieves partial composite action between the HCB elements, resulting in a strain incompatibility between them. The current methodology was found to be unable to predict the maximum compressive strain in the concrete arch. The modified procedure is based on the strain compatibility assumption. However, it models the HCBs as curved beam rather than a straight one, using a simplified spring model to represent the beam supports. These modifications achieved significant enhancements in estimating the strains under service loads.
Using Video Modeling to Teach a Meal Preparation Task to Individuals with a Moderate Intellectual Disability
Authors: Kanfush Philip M. , Jaffe Jordan W.
Published: March 2019

A single-subject study implementing an AB design with 3 replications was conducted with 4 adolescents having multiple disabilities, including moderate cognitive impairments, to demonstrate the efficacy of a video modeling and video-prompting intervention to teach a food preparation skill. Each participant was taught to prepare a different food item using a task analysis comprising 50 to 64 steps. Within 12 training sessions, each participant achieved criterion performance, completing at least 90% of their cooking task steps independently. Three out of 4 participants maintained their food preparation skill in a maintenance probe taken 6 weeks after instruction ended. The fourth participant completed 89% of the task’s steps independently during the maintenance probe. The findings of this study are consistent with those of earlier studies and suggest that video modeling may be a very effective and efficient method for promoting independence, participation, and self-determination among individuals with moderate intellectual disabilities. This study extends the literature base by focusing on longer, more complex meal preparation tasks than earlier studies.
Chaotic Adaptive Butterfly Mating Optimization and Its Applications in Synthesis and Structure Optimization of Antenna Arrays
Authors: Li Bin , Liu Chao , Wu Huaning , Zhao Yifeng , Dong Yinghui
Published: March 2019

A novel chaotic adaptive butterfly mating optimization (CABMO) is proposed to be used in synthesizing the beam pattern. In order to improve the optimization accuracy and avoid trapping in the local optimum, the homogeneous chaotic system and adaptive movement mechanism are combined into the proposed algorithm, where the initialization and redistribution of butterflies are chaotically dispersed with an adaptive movement closely related to the ultraviolet changes. After validating the performance of CABMO through several benchmark functions with different dimensions, the improved algorithm outperforms when compared to other state-of-the-art nature-inspired metaheuristic algorithms. The proposed algorithm is then used to understand any linear array problems in terms of the sidelobe reduction. Finally, a CABMO strategy is utilized to optimize the mutual coupling model of the closely spaced VLF umbrella arrays. Results show that the optimized structure has comfortably outperformed the original structure. Full scanning of wave positions is realized from 15 to 30 kHz. The synthesis patterns are close to the theoretical optimum. The optimized results of the radiation performance and synthesized patterns demonstrate that the pattern synthesis and antenna structure optimization based on the CABMO algorithm provides a novel idea for antenna array optimization.
Numerical Investigation of Load‐Carrying Capacity of GFRP‐Reinforced Rectangular Concrete Members Using CDP Model in ABAQUS
Authors: Raza Ali , Khan Qaiser uz Zaman , Ahmad Afaq
Published: March 2019

The present work demonstrates the nonlinear finite element analysis (NLFEA) of 13 concentrically and eccentrically loaded short rectangular concrete column specimens reinforced with GFRP and conventional steel bars. GFRP bars are lightweight having the high tensile strength and high corrosion resistance. An NLFEA model for the rectangular concrete specimens was developed using the commercial software ABAQUS Standard and calibrated for different materials and geometric parameters based on the previous experimental test results of the studied specimen. The behavior of reinforced concrete was modelled using the concrete damaged plasticity (CDP) model, the behavior of steel bars was simulated as a bilinear elastoplastic material, and the GFRP bars were considered as a linear elastic material. After the calibration of CDP parameters, the control sample was used for the further numerical parametric analysis to investigate the effect of critical parameters, i.e., the area of concrete (Ac), the compressive strength of concrete (), and the ratio of longitudinal reinforcement (ρl) and transverse reinforcement (ρt) on the load‐carrying capacity of columns. The results show that the selected NLFEA model can simulate the behavior of columns accurately and there was good agreement of numerical results obtained from ABAQUS Standard with the experimental results.
Size Effects of Finite Element Model for Three-Dimensional Microstructural Modeling of Asphalt Mixture
Authors: Wu Kuanghuai , Deng Qingzi , Deng Naiming , Cai Xu , Huang Wenke
Published: March 2019

Asphalt mixture is a particulate composite material consisting of aggregate, mastic, and air voids. The computed tomography (CT) image-based finite element approach is used as an effective method to simulate micromechanical response of asphalt mixture. For finite element analysis, the accuracy of the finite results is determined by the size of the finite element. In this paper, a voxel-based three-dimensional (3D) digital reconstruction model of asphalt mixture with the CT images after being processed was proposed. In this 3D model, the aggregate phase was considered as elastic materials while the asphalt mastic phase was considered as linear viscoelastic material. Four micromechanical digital models were generated, whose voxel sizes were 0.5 mm, 0.67 mm, 1.0 mm, and 2.0 mm, respectively. The four digital models were used to conduct uniaxial creep test for predicting creep stiffness modulus to investigate the effect of voxel size. Simulation results showed that the voxel sizes had a significant effect on creep stiffness modulus. For the creep simulation test, the most appropriate voxel size whose creep stiffness modulus changes within 2.5% is 1.0 mm with regard to time steps, computational time, aggregate, and mastic shape representations.
Towards Reinforced Brain Tumor Segmentation on MRI Images Based on Temperature Changes on Pathologic Area
Authors: Bousselham Abdelmajid , Bouattane Omar , Youssfi Mohamed , Raihani Abdelhadi
Published: March 2019

Brain tumor segmentation is the process of separating the tumor from normal brain tissues; in clinical routine, it provides useful information for diagnosis and treatment planning. However, it is still a challenging task due to the irregular form and confusing boundaries of tumors. Tumor cells thermally represent a heat source; their temperature is high compared to normal brain cells. The main aim of the present paper is to demonstrate that thermal information of brain tumors can be used to reduce false positive and false negative results of segmentation performed in MRI images. Pennes bioheat equation was solved numerically using the finite difference method to simulate the temperature distribution in the brain; Gaussian noises of ±2% were added to the simulated temperatures. Canny edge detector was used to detect tumor contours from the calculated thermal map, as the calculated temperature showed a large gradient in tumor contours. The proposed method is compared to Chan–Vese based level set segmentation method applied to T1 contrast-enhanced and Flair MRI images of brains containing tumors with ground truth. The method is tested in four different phantom patients by considering different tumor volumes and locations and 50 synthetic patients taken from BRATS 2012 and BRATS 2013. The obtained results in all patients showed significant improvement using the proposed method compared to segmentation by level set method with an average of 0.8% of the tumor area and 2.48% of healthy tissue was differentiated using thermal images only. We conclude that tumor contours delineation based on tumor temperature changes can be exploited to reinforce and enhance segmentation algorithms in MRI diagnostic.
Changes in Vitamin D Status in Overweight Middle-Aged Adults with or without Impaired Glucose Metabolism in Two Consecutive Nordic Summers
Authors: Lundström Petra , Caidahl Kenneth , Eriksson Maria J. , Fritz Tomas , Krook Anna , Zierath Juleen R. , Rickenlund Anette
Published: March 2019

Background. Sun exposure is the main driver of vitamin D synthesis. High latitude, obesity, and type 2 diabetes mellitus (T2DM) are all risk factors for vitamin D deficiency. However, the seasonal variation in vitamin D concentrations (25[OH]D) in such populations before and after sun exposure during the summer is unknown. Therefore, we investigated 25[OH]D status before and after two consecutive summers in high latitude and its associations with body fat, sex, and glucose metabolism. Methods. 158 participants from Sweden (87 women, 71 men; mean age, 60 ± 5 y; body mass index ≥ 25 kg/m2) and 25[OH]D were measured and evaluated in relation to normal or impaired glucose tolerance, body composition, and dietary habits during summer season. Results. Eighty-four percent of the participants were categorized with low to deficient 25[OH]D values before summer (55.1 ± 21.7 nmol·L−1), with a significant increase after the summer season (66.3 ± 21.0 nmol·L−1; P<0.001). However, the values remained below the recommended range (76–250 nmol·L−1) in 66% of the participants. These findings were verified in a subgroup of the study population during the subsequent summer. Participants who reported use of vitamin D supplements had higher initial concentrations (64.2 ± 20.1 nmol·L−1) compared to nonusers (53.7 ± 21.7 nmol·L−1; P=0.04). Further, 25[OH]D values correlated negatively with fat mass (kg) prior to summer only in the female population (r=−0.29, P=0.008). Conclusions. In the present study, sun exposure had a beneficial but insufficient effect on 25[OH]D levels, and the same levels were documented in two consecutive summer seasons, confirming that vitamin D supplementation in both summer and winter should be considered in this population.
Shear-Force Sensors on Flexible Substrates Using Inkjet Printing
Authors: Albrecht Andreas , Trautmann Mauriz , Becherer Markus , Lugli Paolo , Rivadeneyra Almudena
Published: March 2019

Printing techniques are a promising way of fabricating low-cost electronics without the need for masking and etching. In recent years, additive printing techniques, such as inkjet and screen printing, have been adopted to fabricate low-cost and large-area electronics on flexible substrates. In this work, a three-axial normal and shear force sensor was designed and printed that consists of four miniaturized, printed capacitors. The partially overlapping electrodes are arranged in a manner, so that force sensitivity in orthogonal directions is achieved. A silicone rubber is used as an elastic dielectric and spacer between the two electrodes. The base unit of this sensor has been fabricated using inkjet printing and characterized for normal and shear forces. The force response was investigated in a force range from 0.1 N to 8 N, the normal-force sensitivity was determined to be Sz=5.2 fF/N, and the shear-force sensitivity was Sy=13.1 fF/N. Due to its sensing range, this sensor could be applicable in tactile sensing systems like wearables and artificial electronic skins.
Pharmacological Studies Pertaining to Smooth Muscle Relaxant, Platelet Aggregation Inhibitory and Hypotensive Effects of Ailanthus altissima
Authors: Rahman Hafiz Muhammad Abdur , Rasool Muhammad Fawad , Imran Imran
Published: March 2019

Objective. This in vitro and in vivo study was conducted to rationalize some of traditional medicinal uses of Ailanthus altissima in gastrointestinal, respiratory, and cardiovascular systems. Materials. Crude extract of Ailanthus altissima (Aa.Cr) and its fractions were prepared and utilized in in vitro and in vivo studies. For in vitro studies, Aa.Cr was investigated on isolated rabbit jejunum, isolated tracheal strip, and isolated aorta of rat suspended in tissue organ bath. Platelet rich and platelet poor plasma were used to study platelet aggregation inhibitory activity. In vivo antidiarrheal effect of Aa.Cr was investigated on balb/c mice pretreated with castor oil to induce diarrhea and SD rats were used to study hypotensive activity. Results. Concentration dependent spasmolytic effects of Aa.Cr and its DCM fraction (Aa.DCM) were observed on spontaneous and spasmogen induced contractions in jejunum isolated from rabbit, but effect against high potassium (high-K+) induced contractions was more potent. Moreover Aa.Cr showed parallel shifting of calcium response curve to the right side. While its aqueous fraction (Aa.aq) caused spasmogenesis of isolated rabbit jejunum, this effect was blocked partially with prior administration of atropine (1μM). Concentration dependent protection against castor oil induced diarrhea was also observed. Relaxant effect was observed by the application of Aa.Cr and Aa.DCM against high-K+ and carbachol (CCh) induced contractions in tracheal strips isolated from SD rats, while Aa.Aq caused partial relaxation of high-K+ induced contractions, but no effect was observed against CCh induced contractions. Relaxation of rat aorta by the application of Aa.Cr and its fractions was also observed. Inhibition of force of contraction in rabbit atrium was also observed. Inhibition of platelet aggregation was observed against epinephrine and ADP induced aggregation. Conclusion. Keeping in view the observed results, it is concluded that smooth muscle relaxant, platelet aggregation inhibitory and hypotensive effect may be due to the blockage of calcium channels.
Aldosterone Antagonists Reduce the Risk of Cardiovascular Mortality in Dialysis Patients: A Meta-Analysis
Authors: Li Yan , Xie Na , Liang Min
Published: March 2019

Background and Purpose. Cardiovascular disease is the major cause of death in dialysis patients. Although aldosterone antagonists were considered a treatment for severe heart failure patients to reduce cardiac mortality, whether treating patients undergoing maintenance dialysis with aldosterone antagonists could reduce the risk of cardiocerebrovascular (CCV) remains unclear. We aim to systematically assess the efficacy and tolerability of the addition of aldosterone antagonists to conventional therapy in patients undergoing maintenance dialysis. Materials and Methods. We searched PubMed, EMBASE, the Cochrane Library, the Chinese Biomedical Literature Database (CBM), and the China National Knowledge Infrastructure (CNKI) for relevant articles. The primary endpoint of interest was CCV mortality. The secondary endpoints were all-cause mortality, left ventricular mass index (LVMI), and left ventricular ejection fraction (LVEF). Publication bias was evaluated using funnel plots and Egger’s test. The meta-analysis was performed using Review Manager software version 5.3. Results. This analysis included 10 randomized controlled trials (RCTs) with 1172 total chronic dialysis patients. The use of aldosterone antagonists in the dialysis population resulted in a marked reduction in CCV mortality (RR 0.42, 95% CI 0.26-0.65, P=0.0002) and all-cause mortality (RR0.46, 95%CI 0.32-0.66, P<0.0001). The LVEF was improved by treatment with aldosterone antagonists (WMD 6.35%, P<0.00001). Moreover, aldosterone antagonists decreased the LVMI (WMD -8.69 g/m2, P=0.0006), whereas aldosterone antagonists increased the occurrence of hyperkalemia (RR1.70, 95%CI 1-2.88, P=0.05) and gynecomastia (RR 8.01, 95% CI 2.44- 26.27, P=0.0006). Conclusions. Addition of aldosterone antagonists to conventional treatment in chronic dialysis patients may reduce CCV mortality, improve cardiac function, and simultaneously decrease LVMI.
Analysis of the Mechanical Behavior of Bolted Beam‐Column Connections with Different Structural Forms
Authors: Yang Rongqian , Zhou Xuejun
Published: March 2019

In order to study the mechanical behavior of bolted beam‐column connections, the accuracy and applicability of the finite element model were firstly validated according to the published experiments on end‐plate connections using ABAQUS. Then, in order to discuss the mechanical behavior of connections, three semirigid connections which are convenient for prefabricated construction, including top‐and‐seat angle connections with web and ear plate, extended end‐plate connection, and T‐stub connection, were examined using numerical simulation analysis to study and compare their capacity, hysteretic behavior, ductility, and degradation characteristics in detail. The results showed that the finite element models that were built could effectively simulate the load bearing behavior of bolted connections under both single‐direction loading and cyclic loading. The three connections showed good load bearing capacity. The connectors significantly affected the energy dissipation capacity under load. The extended end‐plate connection demonstrated the best performance in both mechanical behavior and manufacture and installation, so it would therefore be the preferred option.
Prominent T-Cell Responses against the Acetylcholine Receptor ε Subunit in Myasthenia Gravis
Authors: Neuhaus Oliver , Wiesmüller Karl-Heinz , Hartung Hans-Peter , Wiendl Heinz
Published: March 2019

The human acetylcholine receptor (AChR) is well characterized as the target antigen in myasthenia gravis (MG). Pathogenic antibody responses against the AChR alpha-chain have been investigated extensively and are of diagnostic and prognostic value. However, less is known on the pathogenetic relevance of T-cell responses against epitopes of the different AChR chains (alpha, epsilon, gamma). Using an enzyme-linked immunospot (ELISPOT) assay we measured T-cell responses against recombinant fragments and synthetic peptides of the α and the ε subunits of the human AChR in MG patients (n=15) and in healthy donors (HD; n=9). In MG, highest T-cell responses were noted against recombinantly expressed Epsilon 1-221. Among the synthetic peptides Epsilon 201-215 showed the most prominent T-cell response and represented the peptide with the most remarkable difference between MG and HD. Taken together, prominent T-cell responses against the ε subunit of the human AChR indicate an important role in the pathogenesis of MG.
The Impact ofPlasmodiumInfection on Placental Histomorphology: A Stereological Preliminary Study
Authors: Ahenkorah John , Tetteh-Quarcoo Patience B. , Nuamah Mercy A. , Kwansa–Bentum Bethel , Nuamah Hanson G. , Hottor Bismarck , Korankye Emmanuel , Torto Magdalene , Ntumy Michael , Addai Fredrick K.
Published: March 2019

Background. Malaria during pregnancy may threaten the mother’s health and cause serious structural damage to the internal architecture of the placenta, which subsequently affects the pregnancy outcome. A better understanding of the impact of malaria parasites on the placenta morphology is crucial for better management of pregnant women and their babies.Aim. To assess by stereology the histomorphology of selected placental structures in placenta malaria compared with normal placentae at term.Method. A total of 10 placentae comprising 5 controls and 5 cases were selected from 50 placentae that were collected at term (38 weeks ± 2 weeks) from the maternal delivery suit of Korle-Bu Teaching Hospital in Accra, Ghana. Blood from the placentae was collected for both rapid diagnostic test and microscopic examinations. Samples collected were examined forPlasmodiumparasites, after which they were classified as study group (Plasmodiumpositive) or control (Plasmodiumnegative). Stereological quantification using systematic uniform random sampling technique with test point and intersection counting of photomicrographs were employed to estimate the mean volume densities of syncytial knots, syncytial necrosis, foetal capillaries, and intervillous spaces of the placentae on a total of 1,600 photomicrographs.Results. Out of the fifty placental samples from the maternal side tested forPlasmodium,six representing 12% were found to be infected with the parasite by both rapid diagnostic test and microscopy. On stereological assessment, the mean volume density of syncytial knots was significantly higher in the placental malaria group compared with the control placentae at term (P = 0.0080), but foetal capillaries (P = 0.7813), intervillous spaces (P = 0.8078), and syncytial necrosis (P = 0.8249) were not significantly different.Conclusion. This preliminary result indicates that placental malaria may cause significant increase in the syncytial knots but not foetal capillaries, intervillous spaces, or syncytial necrosis. This finding signifies early maturation of the placenta and may be crucial in understanding perinatal outcomes.
Fractal Loading Model of the Joint Interface Considering Strain Hardening of Materials
Authors: Wang Yanhui , Zhang Xueliang , Wen Shuhua , Chen Yonghui
Published: March 2019

Based on fractal geometry theory, the deformation state of the four stages of the asperity elastic, first elastoplastic, second elastoplastic, and fully plastic deformation and comprehensively considering the hardness of the asperity changes with the amount of deformation in elastoplastic deformation stage due to strain hardening are considered, thereby establishing a single-loading model of the joint interface. By introducing the pushing coefficient and the asperity frequency exponent, each critical frequency exponents of asperity is obtained, and the relationship between the normal contact load and the contact area of the first elastoplastic deformation phase and the second elastoplastic deformation phase of the single asperity in the case of taking into account the change in hardness is inferred, eventually deducing the relationship between the total contact load of the joint interface and the contact area. The analysis results show that in the elastoplastic deformation stage, when the deformation is constant, the asperity load considering the hardness change is smaller than the unconsidered load, and the difference increases with the increase of the deformation amount. The establishment of the model provides a theoretical basis for further research on the elastoplastic contact of joint interfaces.
Survey of the Thermodynamic Properties of the Charge Density Wave Systems
Authors: Saint-Paul M. , Monceau P.
Published: March 2019

We reexamine the thermodynamic properties such as specific heat, thermal expansion, and elastic constants at the charge density wave (CDW) phase transition in several one- and two-dimensional materials. The amplitude of the specific heat anomaly at the CDW phase transition TCDW increases with increasing TCDW and a tendency to a lineal temperature dependence is verified. The Ehrenfest mean field theory relationships are approximately satisfied by several compounds such as the rare earth tritelluride compound TbTe3, transition metal dichalcogenide compound 2H-NbSe2, and quasi-one-dimensional conductor K0.3MoO3. In contrast inconsistency exists in the Ehrenfest relationships with the transition metal dichalcogenide compounds 2H-TaSe2 and TiSe2 having a different thermodynamic behavior at the transition temperature TCDW. It seems that elastic properties in the ordered phase of most of the compounds are related to the temperature dependence of the order parameter which follows a BCS behavior.
Effects of Interventions with Manipulatives on Immediate Learning, Maintenance, and Transfer in Children with Mathematics Learning Disabilities: A Systematic Review
Authors: Lafay Anne , Osana Helena P. , Valat Marion
Published: March 2019

Manipulatives are concrete or virtual objects (e.g., blocks and chips) often used in elementary grades to illustrate abstract mathematical concepts. We conducted a systematic review to examine the effects of interventions delivered with manipulatives on the learning of children with mathematics learning disabilities (MLD). The outcomes observed in the sample (N = 38) were learning, maintenance, and transfer in a variety of mathematical domains. Interventions using manipulatives were reported to be effective for a range of learning objectives (e.g., conceptual understanding and computational fluency), but several methodological weaknesses were observed. Analyses also highlighted considerable heterogeneity in the studies reviewed in terms of participant characteristics, intervention approaches, and methodology. We discuss overall effects of interventions with manipulatives in the MLD population, the methodological quality across the sample, and implications for practice.
Optimized Complex Network Method (OCNM) for Improving Accuracy of Measuring Human Attention in Single-Electrode Neurofeedback System
Authors: Wu Zheng-Ping , Zhang Wei , Zhao Jing , Chen Chun , Ji Peng
Published: March 2019

A neurofeedback system adjusting an individual’s attention is an effective treatment for attention-deficit/hyperactivity disorder (ADHD). In current studies, an accurate measure of the level of human attention is one of the key issues that arouse much interest. This paper proposes a novel optimized complex network method (OCNM) for measuring an individual’s attention level using single-electrode electroencephalography (EEG) signals. A time-delay embedding algorithm was used to reconstruct EEG data epochs into nodes of the OCNM network. Euclidean distances were calculated between each two nodes to decide edges of the network. Three key parameters influencing OCNM, i.e., delaying time, embedding dimension, and connection threshold, were optimized for each individual. The average degree and clustering coefficient of the constructed network were extracted as a feature vector and were classified into two patterns of concentration and relaxation using an LDA classifier. In the offline experiments of six subjects, the classification performance was tested and compared with an attention meter method (AMM) and an α + β + δ + θ + R method. The experimental results showed that the proposed OCNM achieved the highest accuracy rate (80.67% versus 70.58% and 68.88%). This suggests that the proposed method can potentially be used for EEG-based neurofeedback systems with a single electrode.
Protective Effects of Evodiamine against LPS-Induced Acute Kidney Injury through Regulation of ROS-NF-κB-Mediated Inflammation
Authors: Shi Yan , Hua Qiuju , Li Na , Zhao Min , Cui Yan
Published: March 2019

Acute kidney injury (AKI) is a critical care syndrome, which is usually associated with sepsis-related endotoxemia. Evodiamine (EVO) is an active ingredient of many traditional medicinal formulations that possess a battery of biological activities. In the study, we aimed to evaluate the potential protective effect of EVO against lipopolysaccharide- (LPS-) induced AKI and cytotoxicity. LPS-resulted pathological injuries were significantly ameliorated by the administration of EVO. EVO reduced the levels of blood urea nitrogen (BUN) and creatinine in LPS-treated rats. EVO also inhibited LPS-induced reduction of cell viability in NRK-52E cells. LPS-resulting increase of TNFαand IL-1βin both serum and kidney of rats and NRK-52E cells was inhibited by EVO. LPS-induced increase of P65 NF-κB expression was markedly inhibited by EVO. EVO-induced reduction of TNFαand IL-1βexpression in LPS-treated cells was blocked by overexpression of P65 NF-κB. Moreover, the increase of cell viability in LPS-treated cells induced by EVO was remarkably suppressed by overexpression of P65 NF-κB. LPS-resulting increase of reactive oxygen species (ROS) production was suppressed by EVO. H2O2suppressed EVO-induced decrease of P65 NF-κB expression and increase of cell viability in LPS-treated NRK-52E cells. Moreover, the antioxidant NAC significantly promoted EVO-induced decrease of P65 NF-κB expression and increase of cell viability in LPS-treated NRK-52E cells. In conclusion, EVO had crucial protective effects against LPS-induced AKI and cytotoxicity through the antioxidant activities and thus the inhibition of inflammation. Our data highlight EVO as a potential candidate for the development of new strategies for the treatment of AKI.