bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Mechanical Analysis of ABS From Hybrid Additive Manufacturing by Fused Filament Fabrication and Shot Peening
Authors: Hadidi Haitham , Mailand Brady , Sundermann Tayler , Johnson Ethan , Karunakaran Rakeshkumar , Negahban Mehrdad , Delbreilh Laurent , Sealy Michael
Published: January 2021

The mechanical properties of 3D printed polymers parts are process parameter dependent. Defects such as inadvertent voids between deposited rasters and layers lead to weakness in produced parts, which results in inferior mechanical properties as compared to injection molding. An alternative method to change energy absorption and stiffness of a polymer is hybrid additive manufacturing (AM). Hybrid-AM is the use of additive manufacturing with one or more secondary processes that are fully coupled and synergistically affect part quality, functionality, and/or process performance. In this study, fused filament fabrication (FFF) was coupled with layer-by-layer shot peening to study the dynamic mechanical properties of ABS 430 polymer using dynamic mechanical analysis (DMA). FFF is a heated extrusion process. Shot peening is a mechanical surface treatment that impinges a target with a stochastically dispersed, high velocity stream of beads. Compressive residual stress was imparted to preferential layer intervals during printing to modify the elasticity (stiffness), viscosity, toughness, and glass transition temperature. Viscoelastic and dynamic mechanical properties are important to the performance of polymers in automotive, aerospace, electronics, and medical components. Coupling printing and peening increased the storage and loss moduli as well as the tangent delta. DMA results suggest that preferential layer sequences exist that possess higher elasticity and better absorb energy upon sinusoidal dynamic loading.
Interval Multi-Objective Evolutionary Optimization for Disassembly Line Balancing With Uncertain Task Time
Authors: Fang Yilin , Zhang Hanke , Liu Quan , Zhou Zude , Yao Bitao , Pham Duc Truong
Published: January 2021

In the disassembly line balancing problem, the disassembly time of task is usually uncertain due to the influence of various factors. Interval number theory is very suitable to solve this problem. In this paper, a new interval mathematical model is proposed and the objectives are to minimize the cycle time and the total energy consumption of robots. To solve this problem, an evolutionary algorithm named γ based-NSGA-II for the interval multi-objective optimization is proposed. This algorithm directly solve the original interval multi-objective optimization problem by using interval Pareto dominance and interval crowding distance, rather than transforming the problem into a determined parameter optimization problem, which can retain the uncertain information, making the solution more reliable. And the local search operator is proposed to strength the local search ability of the algorithm. Experiment is executed in the three scale problems. By comparing the value of HV-U and HV-D, the influence of γ on the convergence, distribution and uncertainty of the algorithm is analyzed, and the optimal value of γ for this problem is found. On this basis, the performance of the proposed γ based-NSGA-II is compared with NSGA-II and MOEA / D by the value of IGD. The results show that the proposed algorithm has good performance in the small and medium scale problems.
Observation at the Interelectrode Gap of Micro Electric Discharge Milling
Authors: Mullya Satish A. , Karthikeyan G. , Patil Ranjit S. , Patil Rajkumar B.
Published: January 2021

The rapid phenomenon happening at the interelectrode gap (IEG) of 50 microns in the micro electric discharge milling (μED-milling) is complex. Various techniques such as computational fluid dynamics (CFD), scanning electron microscope (SEM), and the high-speed camera is utilized to study the behavior. As multiple process occurs in microseconds, high-speed video camera is useful to capture rapidly occurring events. The actual process images at the interelectrode gap (IEG) of the micro electric discharge milling (μED-milling) is captured using a high-speed video camera pco. dimax HS4 highspeed CMOS camera. This camera can capture images at a maximum frame rate of 46746 fps at a lower resolution of 320 × 200. The images of spark and dielectric flow are captured at a high resolution and a frame rate of 2277 fps. The high-speed images show sparking to be continuous along the periphery of the tool which is unique in μED-milling. The obtained images of the spark are used to find the IEG size and the bubble motion is used to calculate the velocity of the dielectric. The dielectric motion is majorly vortex flow and is observed at the back of the tool due to tool rotation. The SEM images show spherical debris particles deposited on the machined surface. The size of the debris particles depends on the input energy. Larger crater is formed on the workpiece surface at high energy levels which eventually forms large size debris particles. All the techniques used provide useful information and shows close resemblance.
Nanoclay Suspension-Enabled Extrusion Printing of 3D Soft Structures for Biomedical Applications
Authors: Jin Yifei , Antonelli Patrick J. , Long Christopher J. , McAleer Christopher W. , Hickman James J. , Xiong Ruitong , Huang Yong
Published: January 2021

Three-dimensional (3D) extrusion printing of cellular/acellular structures with biocompatible materials has been widely investigated in recent years. However, the requirement of suitable solidification rate of printable ink materials constrains the utilization of extrusion-based 3D printing technique. In this study, the yield-stress nanoclay suspension-enabled extrusion-based 3D printing system has been investigated and demonstrated to overcome solidification rate constraints during printing. Utilizing the liquid-solid transition property of nanoclay suspension, two fabrication approaches, including nanoclay support bath-enabled printing and nanoclay-enabled direct printing, have been proposed. For the former approach, nanoclay (Laponite EP) has been used as a support bath material to fabricate alginate-based tympanic membrane patches. The constituents of alginate-based ink have been investigated to have the desired mechanical property of alginate-based tympanic membrane patches and facilitate the printing process. For the latter approach, nanoclay (Laponite XLG) has been used as an internal scaffold material to help print poly (ethylene glycol) diacrylate (PEGDA)-based neural chambers, which can be further cross-linked in air. Mechanical stress analysis has been performed to explore the geometric limitation of printable Laponite XLG-PEGDA neural chambers.
A Framework for Industrial Robot Training in Cloud Manufacturing With Deep Reinforcement Learning
Authors: Liu Yongkui , Yao Junying , Lin Tingyu , Xu He , Shi Feng , Xiao Yingying , Zhang Lin , Wang Lihui
Published: January 2021

Cloud manufacturing is a service-oriented networked manufacturing model that embraces the concept of ‘Everything-as-a-Service’. In cloud manufacturing, distributed manufacturing resources encompassed in the product lifecycle are transformed into manufacturing services. Industrial robots are an important category of manufacturing resources in cloud manufacturing. During the past years, robots have been demonstrated to be able to learn various dexterous manipulation skills through training with deep reinforcement learning (DRL). In cloud manufacturing, there are many complex industrial application scenarios that require dexterous robots. Hence, robot training, which enables robots to learn various manipulation skills, becomes an important requirement for cloud manufacturing in the future, leading to the concept of ‘Robot Training-as-a-Service’. This paper focuses on industrial robot training in the context of cloud manufacturing. First, related work on cloud manufacturing, DRL, DRL-based robot training, and cloud-edge collaboration is briefly reviewed and analyzed. Then, a framework for industrial robot training in cloud manufacturing with DRL is proposed, and a simplified case study is presented to demonstrate the basic principle of the framework. Finally, possible future research issues are discussed.
Sketch-Based Tensor Decomposition for Non-Parametric Monitoring of Electrospinning Processes
Authors: Segura Luis Javier , Muñoz Christian Narváez , Zhou Chi , Sun Hongyue
Published: January 2021

Electrospinning is a promising process to fabricate functional parts from macrofibers and nanofibers of bio-compatible materials including collagen, polylactide (PLA), and polyacrylonitrile (PAN). However, the functionality of the produced parts highly rely on quality, repeatability, and uniformity of the electrospun fibers. Due to the variations in material composition, process settings, and ambient conditions, the process suffers from large variations. In particular, the fiber formation in the stable regime (i.e., Taylor cone and jet) and its propagation to the substrate plays the most significant role in the process stability. This work aims to designing a fast process monitoring tool from scratch for monitoring the dynamic electrospinning process based on the Taylor cone and jet videos. Nevertheless, this is challenging since the videos are of high frequency and high dimension, and the monitoring statistics may not have a parametric distribution. To achieve this goal, a framework integrating image analysis, sketch-based tensor decomposition, and non-parametric monitoring, is proposed. In particular, we use Tucker tensor-sketch (Tucker-TS) based tensor decomposition to extract the sparse structure representations of the videos. Additionally, the extracted monitoring variables are non-normally distributed, hence non-parametric bootstrap Hotelling T2 control chart is deployed to handle this issue during the monitoring. The framework is demonstrated by electrospinning a PAN-based polymeric solution. Finally, it is demonstrated that the proposed framework, which uses Tucker-TS, largely outperformed the computational speed of the alternating least squares (ALS) approach for the Tucker tensor decomposition, i.e., Tucker-ALS, in various anomaly detection tasks while keeping the comparable anomaly detection accuracy.
Identification of Young’s Modulus and Equivalent Spring Constraint Boundary Conditions of the Object With Incomplete Displacement Boundary Conditions
Authors: Xu Tian , Lei Yong
Published: January 2021

In endoscopic surgery, the surgical navigation needs to calculate the internal deformation of the soft tissue by biomechanical model which needs to determine the elastic properties and boundary conditions. However, these information cannot be obtained accurately in a real operation scenario. For example, only a limited portion of a liver surface can be observed in a hepatic surgery under endoscope while its elastic properties remain unknown. In addition, simple boundary conditions such as fixed constraints and free-force constraints are not physically adequate to simulate the elastic effect of ligaments attached to the liver. Biomechanical models of the soft tissue have been thoroughly studied in recent years. In these studies, boundary conditions play an important role in identification of elastic properties for mechanical model based methods. But they rarely combine these unknown conditions together to construct the model, and instead set boundary conditions or elastic properties as known for simplification. In this paper, we present a novel method to identify the Young’s modulus and equivalent spring constraint boundary conditions of a partially observed soft object with incomplete boundary conditions. The spring constraint boundary condition is applied to alternate the conventional displacement boundary conditions (e.g. free constraint and fixed constraint) and an inverse algorithm based on the standard finite element method (FEM) and Gauss-Newton (GN) method is developed, which takes external forces and displacements of observable nodes as inputs. A series of numerical simulation experiments are implemented and the analysis of simulation results show the feasibility of the proposed method.
Human-in-Cognition Manufacturing-Loop (HCML): Framework and Technologies
Authors: Jiang Yanan , Liu Yahui , Bao Jinsong , Li Jie , Zhang Jie , Fang Yunhao
Published: January 2021

The wave of intelligent manufacturing has swept the world, and intelligent manufacturing has realized the interconnection of the physical world and the information world. With the deep integration of intelligent manufacturing, cognitive computing and cognitive science, the manufacturing industry presents a new manufacturing model, which is called cognitive manufacturing. Cognitive manufacturing, as the evolution stage of intelligent manufacturing, endows industrial manufacturing system with perception and judgment ability. In addition, it enables the machine to realize self-adaptation, self-organization and self-decision-making based on cognition, thus completing accurate execution. But the manufacturing system cannot be entirely controlled by machines without the involvement of human. Based on the new generation of intelligent manufacturing for human-information-physical system and human-computer synthetic-intelligent system. This paper compares and extends the relevant technical models of intelligent manufacturing and cognitive manufacturing. Furthermore, it presents a framework that integrates the cognitive ability of human and machine, putting forward a cognitive manufacturing system architecture of human-machine collaborative cognition, called Human-in-Cognition Manufacturing-Loop (HCML). Additionally, the connotation, key implementation technology and future development trend of the system are discussed in details, and the role of artificial intelligence in the system are introduced.
Effects of Shield Gas Flow on Meltpool Variability and Signature in Scanned Laser Melting
Authors: Deisenroth David C. , Neira Jorge , Weaver Jordan , Yeung Ho
Published: January 2021

In laser powder bed fusion metal additive manufacturing, insufficient shield gas flow allows accumulation of condensate and ejecta above the build plane and in the beam path. These process byproducts are associated with beam obstruction, attenuation, and thermal lensing, which then lead to lack of fusion and other defects. Furthermore, lack of gas flow can allow excessive amounts of ejecta to redeposit onto the build surface or powder bed, causing further part defects. The current investigation was a preliminary study on how gas flow velocity and direction affect laser delivery to a bare substrate of Nickel Alloy 625 (IN625) in the National Institute of Standards and Technology (NIST) Additive Manufacturing Metrology Testbed (AMMT). Melt tracks were formed under several gas flow speeds, gas flow directions, and energy densities. The tracks were then cross-sectioned and measured. The melt track aspect ratio and aspect ratio coefficient of variation (CV) were reported as a function of gas flow speed and direction. It was found that a mean gas flow velocity of 6.7 m/s from a nozzle 6.35 mm in diameter was sufficient to reduce meltpool aspect ratio CV to less than 15 %. Real-time inline hotspot area and its CV were evaluated as a process monitoring signature for identifying poor laser delivery due to inadequate gas flow. It was found that inline hotspot size could be used to distinguish between conduction mode and transition mode processes, but became diminishingly sensitive as applied laser energy density increased toward keyhole mode. Increased hotspot size CV (associated with inadequate gas flow) was associated with an increased meltpool aspect ratio CV. Finally, it was found that use of the inline hotspot CV showed a bias toward higher CV values when the laser was scanned nominally toward the gas flow, which indicates that this bias must be considered in order to use hotspot area CV as a process monitoring signature. This study concludes that gas flow speed and direction have important ramifications for both laser delivery and process monitoring.
Mechanical Evaluation of Selective Laser Melted Ni-Rich NiTi: Compression, Tension, and Torsion
Authors: Safaei Baghbaderani Keyvan , Nematollahi Mohammadreza , Bayatimalayeri Parisa , Dabbaghi Hediyeh , Jahadakbar Ahmadreza , Elahinia Mohammad
Published: January 2021

Two unique behaviors of superelasticity and shape memory effect have made shape memory alloy such as NiTi, an interesting alloy for different applications. Recently, additive manufacturing (AM) as a powerful tool for fabricating NiTi has become of interest to make complex geometries. Selective laser melting (SLM) is an AM method that not only provides flexibility to make complex 3D shapes but also it can be possible to tailor the thermomechanical properties of the parts just by changing the process parameters. The non-homogenous microstructure of as-fabricated parts as well as asymmetric mechanical behavior of NiTi, make it important to study the properties of SLM NiTi parts under different loading condition. In this study, Ni50.8Ti (at. %) powder was utilized to fabricate cube, dog-bone, and tube by SLM technique. The transformation temperatures (TTs) of samples were measured by the differential scanning calorimetry (DSC) method and the variation of TTs was discussed. Three coupons were tested mechanically under compression, tension, and torsion. In-situ digital image correlation (DIC) was employed to measure and monitor the strain field of samples during the mechanical tests. The strain distribution showed localized strain for all three samples. The equivalent stress/strain was calculated to compare the result of compressive, tensile, and torsional responses and the significant asymmetric behavior was shown and discussed.
Investigation of In-Situ Surface Polishing for Fused Filament Fabrication
Authors: Nigam Aman , Tai Bruce L.
Published: January 2021

Fused filament fabrication (FFF) is one of the most researched techniques in the field of additive manufacturing because of its fast and cost-effective nature. However, the surface quality of these printed parts suffers because of the stairstepping effect, which leads to visible layer lines. Secondary finishing operations are often needed to comply with the design requirements. These post-processing techniques are useful but are labor-intensive and often time-consuming. The present study compares the effects of in-situ polishing of acrylonitrile butadiene styrene (ABS) using chemical and mechanical approaches. The advantages of in-situ settings include ease of operation and lower time consumption. For this, a modified rapid prototyping system was developed which had separate heads for mechanical and chemical polishing. A full factorial experiment was conducted with the two polishing methods and two feed rates. In results, mechanical polishing with end mill with a lower feed rate achieved the best roughness (Ra = 2.047 μm), while chemical polishing with a lower feed rate has the least improvement (Ra = 14.257 μm). General trends, pros, and cons for both chemical and mechanical methods are discussed.
Simultaneous Material Microstructure Classification and Discovery via Hidden Markov Modeling of Acoustic Emission Signals
Authors: Zhao Xinyu , Iquebal Ashif , Sun Huifeng , Yan Hao
Published: January 2021

Acoustic emission (AE) signals have been widely employed for tracking material properties and structural characteristics. In this study, we aim to analyze the AE signals gathered during a scanning probe lithography process to classify the known microstructure types and discover unknown surface microstructures/anomalies. To achieve this, we developed a Hidden Markov Model to consider the temporal dependency of the high-resolution AE data. Furthermore, we compute the posterior classification probability and the negative likelihood score for microstructure classification and discovery. Subsequently, we present a diagnostic procedure to identify the dominant AE frequencies that allow us to track the microstructural characteristics. Finally, we apply the proposed approach to identify the surface microstructures of additively manufactured Ti-6Al-4V and show that it not only achieved a high classification accuracy (e.g., more than 90%) but also correctly identified the microstructural anomalies that may be subjected further investigation to discover new material phases/properties.
Structrual Coloration of Surfaces With Microstructures Replicated by Non-Isothermal Precision Glass Molding
Authors: Zhong Yong , Du Ruxu , Zhang Lin , Yi Allen Y.
Published: January 2021

Micro/nano periodic structures are generally adopted in diffraction gratings. As an important optical component, the diffraction grating has the capability to split and diffract incident white light beams into iridescent beams travelling in different directions. The emerging coloration is a form of structural coloration. In this paper, the non-isothermal precision glass molding is introduced for fast replication of periodic grating structures, which are employed to render iridescent colors on surfaces. Firstly, the effect of colorization and periodic grating profiles is theoretically analyzed. Secondly, different periodic micro gratings on silicon wafer, which are generally generated by photolithography, are employed in non-isothermal precision glass molding process as mold inserts. The molding result indicates that the periodic grating space and depth of grating structures can be precisely replicated from the mold inserts to polymer substrates. Subsequently, the split and iridescent color effects are demonstrated with monochromatic & white incident light beam and compared between samples with different periodic grating spaces. The optical effects of the replicated micro-structures confirm the feasibility of this method. The proposed non-isothermal precision glass molding process provides an alternative manufacturing option for realizing structural colors with large-volume and low-cost.
Toward Structural Fatigue Analysis of Horizontally-Fabricated NiTi via Selective Laser Melting
Authors: Bayati Parisa , Jahadakbar Ahmadreza , Safaie Keyvan , Nematollahi Mohammadreza , Dabbaghi Hediyeh , Haghshenas Meysam , Mahtabi Mohammad , Elahinia Mohammad
Published: January 2021

NiTi (Nitinol) is a shape memory alloy with distinctive properties, such as shape memory, superelasticity, biocompatibility, and low density. All these unique properties make NiTi a great candidate in different applications. However, the conventional fabrication of NiTi encounters many challenges that significantly limits the practical applications of the alloy. As a solution, the Selective Laser Melting (SLM) which is an Additive Manufacturing (AM) technique has been recently used for the fabrication of NiTi parts. Although complex geometries can be fabricated directly from CAD files via SLM, different process parameters significantly affect the parts’ quality and must be optimized for each application. In most of the potential applications, NiTi components undergo cyclic loads and therefore its structural fatigue must be fully studied and considered in the design process. However, due to the nature of the SLM process, the fatigue behaviour of SLM fabricated NiTi is different from the conventional ones. In this work, as an initial step, the fatigue behaviour of the SLM fabricated NiTi in the horizontal direction is studied and the reasons for failure have been discussed. To this end, strain-controlled fatigue tests were performed on NiTi dog-bone samples, and fractography was used to analyze the different defects which could cause the failure or scatter in the results.
Experimental Investigation of Effects of Extrusion Pressure on Cell Growth of Bioprinted Algae Cells in Green Bioprinting
Authors: Jerpseth Laura , Thakare Ketan , Pei Zhijian , Qin Hongmin
Published: January 2021

In bioprinting, biomaterials are deposited layer-by-layer to fabricate structures. Bioprinting has many potential applications in drug screening, tissue engineering, and regenerative medicine. Both animal cells and plant cells can be used to synthesize bioinks. Green bioprinting uses bioinks that have been synthesized using plant cells. Constructs fabricated via green bioprinting contain immobilized plant cells, with these cells arranged at desired locations. The constructs provide scaffolds for cell growth. Printing parameters affecting the growth of cells in green bioprinted constructs include print speed, needle diameter, extrusion temperature, and extrusion pressure. This paper reports a study to examine effects of extrusion pressure on cell growth (measured by cell count) in bioprinted constructs, using bioink containing Chlamydomonas reinhardtii algae cells. Three levels of extrusion pressure were used: 3, 5, and 7 bar. Cell counts in the bioprinted constructs were measured on the third and sixth days after bioprinting. It was found that, as extrusion pressure increased, cell count decreased on both the third and sixth days after bioprinting. Furthermore, the difference in cell counts between the third and the sixth days decreased as extrusion pressure increased. These trends suggest that increasing extrusion pressure during green bioprinting negatively affects cell growth. A possible reason for these trends is physical damage to or death of cells in the bioprinted constructs when extrusion pressure became higher.
An Online Side Channel Monitoring Approach for Cyber-Physical Attack Detection of Additive Manufacturing
Authors: Liu Chenang , Kan Chen , Tian Wenmeng
Published: January 2021

Due to its predominant flexibility in fabricating complex geometries, additive manufacturing (AM) has gain increasing popularity in various mission critical applications, such as aerospace, health care, military, and transportation. The layerby-layer manner of AM fabrication significantly expands the vulnerability space of AM cyber-physical systems, leading to potentially altered AM parts with compromised mechanical properties and functionalities. Moreover, internal alterations of the build are very difficult to detect based on traditional geometric dimensioning and tolerancing (GD&T) features. Therefore, how to achieve effective monitoring and attack detection is a very important problem for broader adoption of AM technology. To address this issue, this paper proposes to utilize side channels for process authentication. An online feature extraction approach is developed based on autoencoder to detect unintended process/product alterations caused by cyber-physical attacks. Both supervised and unsupervised monitoring schemes are implemented based on the extracted features. To validate the effectiveness of the proposed method, two real-world case studies are conducted on a fused filament fabrication (FFF) platform equipped with two accelerometers for process monitoring. Two different types of attacks are implemented. The results demonstrate that the proposed method outperforms conventional process monitoring methods, and can effectively detect part geometry and layer thickness alterations in real time.
Optimizing Fused Deposition Modeling Processing Parameters Using Response Surface Method for Strong Parts
Authors: Alafaghani Ala’aldin , Qattawi Ala , Truong Julia , Jaman Md. Shah , Sun Jian-Qiao
Published: January 2021

Optimizing the processing parameters of fused deposition modeling is a challenging task due to the significant number of factors that influence the quality of the fabricated parts. Therefore, optimizing the dimensional accuracy, surface roughness, or mechanical properties usually requires a considerable amount of test samples. In the presented work, the design of experiments approach was used to minimize the number of tests needed to optimize the factors. Most of the work available in literature did not investigate the interactions between the factors or their second-order effects on the strength and stiffness of fused deposition modeling parts. In this work, the effects of the layer thickness, extrusion temperature, and infill percentage are investigated and optimized to achieve the optimum strength and stiffness of the fabricated parts. The response surface method was used to investigate the interaction effects and second-order effects on the tensile strength and elastic modulus of the fabricated samples. It was found that some interaction and second-order effects exist and affect the strength and stiffness of FDM parts. Generally, increasing the extrusion temperature and infill percentage increase the tensile strength and the elastic modulus. In addition, the predicted data matches the experimental results well. However, multi-objective optimization is needed when choosing the layer thickness.
New taxonomic and ontogenetic data on oribatid mites of the genus Eutegaeus (Acari, Oribatida, Eutegaeidae)

Authors: Ermilov Sergey G.
Published: January 2021

Two new species of the genus Eutegaeus (Oribatida, Eutegaeidae) are described based on specimens from moss in the Queulat National Park of Chile. Eutegaeus aysenensis sp. nov. (description based on the adult, larva, deuto- and tritonymph) is morphologically similar to that of Eutegaeus lagrecai in having long, flagellate interlamellar and notogastral setae and rod-like bothridial seta; it differs from the latter by having smaller body size and comparatively long bothridial seta, the lamella having anteromedial process, and by the absence of striate ornamentation on notogaster. Eutegaeus queulatensis sp. nov. (description based on the adult, proto- and tritonymph) is morphologically similar to that of Eutegaeus membraniger in having a triangular anteromedial lamellar process, long, rod-like bothridial seta, foveate lamella, and dorsal notogastral setae of medium length; it differs from the latter by having smaller body length, thickened notogastral setae, flagellate interlamellar setae, setiform lamellar setae, a tubercle on epimere III, and absence of an anterolateral tooth on the lamella. Based on new information, several characters in the generic diagnosis of Eutegaeus adults are modified or expanded, and a preliminary diagnosis for juveniles is presented. The larva of E. aysenensis sp. nov. is the first to be described for the genus. Nymphs of four species of Eutegaeus are compared.
Improving ultrasound-based multimodal speech recognition with predictive features from representation learning
Authors: Wang Hongcui , Roussel Pierre , Denby Bruce
Published: January 2021

Representation learning is believed to produce high-level representations of underlying dynamics in temporal sequences. A three-dimensional convolutional neural network trained to predict future frames in ultrasound tongue and optical lip images creates features for a continuous hidden Markov model based speech recognition system. Predictive tongue features are found to generate lower word error rates than those obtained from an auto-encoder without future frames, or from discrete cosine transforms. Improvement is apparent for the monophone/triphone Gaussian mixture model and deep neural network acoustic models. When tongue and lip modalities are combined, the advantage of the predictive features is reduced.
Quantifying Achievable Levels of Improvement in Knee Joint Biomechanics During Gait After Total Knee Arthroplasty Relative to Osteoarthritis Severity
Authors: Outerleys Jereme B. , Dunbar Michael J. , Richardson Glen , Hubley-Kozey Cheryl L. , Astephen Wilson Janie L.
Published: January 2021

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.
Single-cell cytometry via multiplexed fluorescence prediction by label-free reflectance microscopy
Authors: Cheng Shiyi , Fu Sipei , Kim Yumi Mun , Song Weiye , Li Yunzhe , Xue Yujia , Yi Ji , Tian Lei
Published: January 2021

Deep learning–augmented reflectance microscopy enables label-free multiplexed cytometry.
Strontium ions protect hearts against myocardial ischemia/reperfusion injury
Authors: Xing Min , Jiang Yun , Bi Wei , Gao Long , Zhou Yan-Ling , Rao Sen-Le , Ma Ling-Ling , Zhang Zhao-Wenbin , Yang Huang-Tian , Chang Jiang
Published: January 2021

A strontium-containing hydrogel protects hearts against myocardial ischemia/reperfusion injury.
Corner-, edge-, and facet-controlled growth of nanocrystals
Authors: Li Yuanwei , Lin Haixin , Zhou Wenjie , Sun Lin , Samanta Devleena , Mirkin Chad A.
Published: January 2021

Energy barrier profiles and reducing conditions yield control over corner-, edge-, and facet-specific nanoparticle growth.
Tembusu Virus Entering the Central Nervous System Caused Nonsuppurative Encephalitis without Disrupting the Blood-Brain Barrier
Authors: Yang Sheng , Huang Yufei , Shi Yonghong , Bai Xuebing , Yang Ping , Chen Qiusheng
Published: January 2021

TMUV disease has caused huge losses to the poultry industry in Asia and is potentially harmful to public health. Neurological symptoms and their sequelae are the main characteristics of this disease.
Real-time continuous glucose monitoring versus self-monitoring of blood glucose in adults with insulin-treated type 2 diabetes: a protocol for a randomised controlled single-centre trial
Authors: Lind Nanna , Lindqvist Hansen Dorte , Sætre Rasmussen Signe , Nørgaard Kirsten
Published: January 2021

Introduction

Medical treatment options for type 2 diabetes (T2D) have increased over the last decade and enhance the possibility of individualised treatment strategies where insulin is still one of them. In spite of the advancements in treatment options, less than one-third of the population with T2D obtain their optimal glycaemic goal. In persons with type 1 diabetes, continuous glucose monitoring (CGM) has shown to be the most important driver for improvement in glycaemic control, even more than insulin-pump therapy. The use of technology in T2D has only been investigated in few studies.

The overall objective of the research study is to examine the effectiveness of the use of CGM versus self-monitoring of blood glucose (SMBG) in persons with insulin-treated T2D on glycaemic variables and patient-reported outcomes on treatment satisfaction, health behaviour and well-being. The independent effect of peer support will also be studied.

Methods and analysis

The study is a single centre, prospective, randomised, open-labelled, three-armed study with the randomisation 2:1:2 in group A with CGM, group B with CGM and peer support, and group C as a control group with SMBG. The participants receive a training course unique for the allocation group. The study runs for 12 months and includes 100 adult participants with insulin-treated T2D, treated at the outpatient clinic at Steno Diabetes Center Copenhagen. Primary outcome is difference in change in time in range. Recruitment begins in August 2020 and ends in July 2021. Final 12-month follow-up is anticipated to be in August 2022.

Ethics and dissemination

The study will be carried out in accordance with the Helsinki Declaration and is approved by the Scientific Ethics Committee of the Capital Region (H-20000843). Data collection and handling will be performed in accordance with the General Data Protection Regulation and is approved by the Danish Data Protection Agency (J-2020-100). Dissemination will be in international peer-reviewed journals, conferences and a plain-language summary for participants.

Trial registration number

ClinicalTrials.gov Registry (NCT04331444).

Protocol version

V.3, 11 December 2020.
Randomised phase II trial of olaparib, chemotherapy or olaparib and cediranib in patients with platinum-resistant ovarian cancer (OCTOVA): a study protocol
Authors: Mansouri Anita , McGregor Naomi , Dunn Rachel , Dobbie Sam , Holmes Jane , Collins Linda , Nicum Shibani
Published: January 2021

Introduction

Patients relapsing within 12 months of platinum-based chemotherapy usually have a poorer response to subsequent treatments. To date, extensive research into the mechanism of resistance to platinum agents in the treatment of ovarian cancer has not resulted in improved responses or longer survival. Further experimental work and clinical trials with novel agents are therefore justified to address this unmet need.

Patients with ovarian, fallopian tube or primary peritoneal cancer that has relapsed within 12 months of platinum-based chemotherapy will be randomised with stratification for BReast CAncer gene (BRCA) status, prior poly (ADP-ribose) polymerase (PARP) exposure and prior antiangiogenic therapy into weekly paclitaxel (chemotherapy), olaparib or the combination of cediranib and olaparib. They will be followed until disease progression or unacceptable toxicity develops. Our trial design permits two investigations. We will compare the efficacy and tolerability of single-agent olaparib with weekly paclitaxel. We will also compare the efficacy and tolerability of olaparib with the combination of olaparib and cediranib. The required sample size of 138 participants (46 per arm) was calculated using a 20% one-sided type I error, 80% power and 15% dropout rate. Recruitment will last 34 months with a follow-up of 18 months.

Methods and analysis

Ethics and dissemination

This study will be conducted under a UK Medicines and Healthcare Products Regulatory Agency Clinical Trials Authorisation. Approval to conduct the study was obtained from the responsible authority before beginning the study. The sponsor will retain ownership of all data arising from the trial. We aim to publish this research in a specialist peer-reviewed scientific journal on study completion. EudraCT number: 2016-000559-28, ethics reference number: 16/LO/2150.

Trial registration number

ISRCTN:ISRCTN14784018, clinicaltrials.gov:NCT03117933; Pre-results.
Nurses’ educational needs when dealing with aggression from patients and their families: a mixed-methods study
Authors: Sato Kana , Kodama Yoshimi
Published: January 2021

Objectives

To explore the type of education needed for nurses when dealing with aggression from patients and their families.

Design

A two-phase sequential mixed-methods study.

Setting

This study was conducted in Japan, with phase I from March to November 2016 and phase II in November 2018.

Main outcome measures

The challenges faced by nurses when dealing with incidents of aggression from the neutral perspective of neither nurse nor patient/family and perceptions of the educational contents developed in this study. Descriptive analyses were used to examine the data retrieved from both phases.

Participants

Phase I entailed semistructured interviews among 11 neutral-party participants who observed aggressive incidents between nurses and patients/families. Phase II consisted of a web survey conducted among 102 nursing students and 308 nursing professionals.

Results

Phase I resulted in the identification of the following five main educational components: understanding the mechanisms of anger and aggression, maintaining self-awareness, observant listening, managing the self-impression, and communicating based on specific disease characteristics. Each component was related to improved communication through self-awareness. The results of phase II indicated that participants positively perceived these educational contents as likely to be effective for dealing with aggression from patients/families.

Conclusions

This study clarified the type of education needed for nurses when dealing with aggression based on multiple viewpoints. Specifically, neutral-party interviews revealed that communication should be improved through self-awareness. A subsequent survey among nurses and nursing students showed that the identified educational contents were positively received.
Effects of improved hypoallergenic fabrics in medical wigs in patients with breast cancer with chemotherapy-induced alopecia: a randomised clinical trial
Authors: Tamai Nao , Minematsu Takeo , Ikeda Mari , Mugita Yuko , Sanada Hiromi
Published: January 2021

Purpose

Chemotherapy causes changes in appearance in patients with cancer. Therefore, to have a normal life, it is necessary for patients to wear a wig. However, wearing a wig may strain an already sensitive scalp during chemotherapy. This study aimed to assess the effects of a hypoallergenic medical wig in breast cancer patients with chemotherapy-induced alopecia (CIA).

Methods

A randomised, single-blind, controlled study was conducted from January 2015 to July 2017 in Tokyo, Japan. Women with non-metastatic breast cancers were enrolled. Participants were provided a hypoallergenic medical wig or a traditional medical wig. The primary endpoint was incidence of scalp dermatitis, including erythema, rash and erosion. The secondary endpoints were incidence of scalp symptoms, alterations in scalp barrier functions and quality of life (QOL). Patients were followed at the start of the first chemotherapy administration and at 13th week.

Results

Fifty-nine women were included in the analysis. At 13th week, the incidence of erythema was 44.8% among patients in the intervention group and 86.7% among patients in the control group, in the intention-to-treat analysis (p<0.01). The incidence of erosion tended to decrease in the intervention group at the 13th week (p=0.09). The incidence of scalp symptoms, alterations in scalp barrier functions and QOL were not significantly different between the groups.

Conclusions

The incidence of dermatitis, including erythema, rash and erosion, decreased when wearing the new hypoallergenic medical wig. The gentle hypoallergenic medical wig is useful in improving erythema in cancer patients with CIA.

Trial registration numberUMIN000021289.
Effusive–constrictive pericarditis in the spectrum of pericardial compressive syndromes
Authors: Janus Scott E , Hoit Brian D
Published: January 2021

When pericardial fluid accumulates and exceed the reserve volume of the pericardium or when the pericardium becomes scarred and inelastic, one of three pericardial compressive syndromes may ensue, namely, cardiac tamponade (CT), characterised by the accumulation of pericardial fluid under pressure; constrictive pericarditis (CP), the result of scarring and loss of the normal elasticity of the pericardial sac; and effusive–constrictive pericarditis (ECP), characterised by the concurrence of a tense pericardial effusion and constriction of the heart by the visceral pericardium. Although relatively uncommon, prevalence estimates vary widely and depend on the nature of the cohorts studied, the methods used to diagnose ECP and the manner in which ECP is defined. Most cases of ECP are idiopathic, reflecting the frequency of idiopathic pericardial disease in general, and other causes include radiation, malignancy, chemotherapy, infection and postsurgical/iatrogenic pericardial disease. The diagnosis of ECP often becomes apparent when pericardiocentesis fails to decrease the right atrial pressure by 50% or to a level below 10 mm Hg. Important non-invasive diagnostic modalities include echocardiography, cardiac magnetic resonance and, to a lesser extent, cardiac CT. In cases with clear evidence of pericardial inflammation, a trial of an anti-inflammatory regimen is warranted. A complete pericardiectomy should be reserved for refractory symptoms or clinical evidence of chronic CP.
Patient-reported outcomes data in patients with psoriatic arthritis from a randomised trial of etanercept and methotrexate as monotherapy or in combination
Authors: Strand Vibeke , Mease Philip J , Maksabedian Hernandez Ervant J , Stolshek Bradley S , Liu Lyrica X H , Collier David H , Kricorian Gregory , Merola Joseph F
Published: January 2021

Objectives

We examined patient-reported outcomes (PROs) in The Study of Etanercept And Methotrexate in Patients with Psoriatic Arthritis (PsA); a 48-week, phase 3, randomised controlled trial that compared outcomes with methotrexate (MTX) monotherapy, etanercept monotherapy, and MTX+ etanercept in patients with PsA.

Methods

Efficacy endpoints included: mean changes from baseline and proportion of patients who reported improvements≥minimal clinically important difference (MCID) at week 24 in treatment groups for Health Assessment Questionnaire-Disability Index, Patient Global Assessment (PtGA), Patient Global Assessment of Joint Pain (PtGAJP) and Medical Outcomes Study Short Form-36 Questionnaire (SF-36) Physical Component Summary (PCS), and Mental Component Summary, and eight domain scores. PROs were analysed as reported (observed), without multiplicity adjustment; therefore, p values are descriptive.

Results

At week 24, patients receiving etanercept monotherapy or MTX+ etanercept combination reported greater improvements (p≤0.05) in PtGA, PtGAJP and SF-36 PCS scores compared with those receiving MTX monotherapy. Compared with MTX monotherapy, higher proportions of patients receiving etanercept monotherapy and combination therapy reported improvements≥MCID in PtGA (etanercept vs MTX, p=0.005) and PtGAJP (MTX +etanercept vs MTX, p=0.038). Across PROs, proportions of patients reporting scores≥age and gender-matched normative values at week 24 ranged from 20.8% to 51.0% with MTX monotherapy, 30.9% to 48.8% with etanercept monotherapy, and 30.6% to 52.3% with MTX+ etanercept combination.

Conclusions

Patients receiving etanercept monotherapy or MTX+ etanercept reported greater improvements from baseline in several PROs compared with those receiving MTX monotherapy. PROs should be incorporated in discussions between patients and clinicians regarding their treatment choices as they can help determine which treatments are more beneficial in patients with PsA.