bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Process Induced Variations in PolyJet Printing With Digital Polypropylene via Homogeneous 3D Tensile Test Coupon
Authors: Tomar Ravi Pratap Singh , Ulu Furkan I. , Kelkar Ajit , Mohan Ram V.
Published: January 2020

The capability of additive manufacturing (AM) of making the monolithic, multi-material structure allow the fabrication of complex parts with varying mechanical properties. Many AM processes and equipment utilize proprietary material stocks from equipment vendors. A better understanding of the digital material mixing behavior to form traditional material configurations during AM is critical.

Many jetting-based AM processes also have the capability to print different material gradient and build them layer by layer in a specific concentration of two or more base materials. This paper investigates the tensile strength and mechanical behavior of these digital materials formed by mixing or multi-material interfaces fabricated by material jetting.

Further, due to the flexibility of orientating the digital design in AM, a part can be created in any orientation; however, processing-induced variation affects the performance of parts, as the way AM forms part is different from traditional manufacturing that leads to many artifacts. These artifacts affect the mechanical properties and behavior of final parts formed in AM. To eliminate the process-induced effect that exits in traditional 2D test coupon, this paper evaluates a homogenized 3D configuration test coupon which reduces the geometric effects in AM, that we had recently proposed and investigated.
Development of 3-D Printed Optically Clear Rigid Anatomical Vessels for Particle Image Velocimetry Analysis in Cardiovascular Flow
Authors: Stanley Nicholas , Ciero Ashley , Timms William , Hewlin Rodward L.
Published: January 2020

In recent years, blood flow analysis of diseased arterial mock vessels using particle image velocimetry (PIV) has been hampered by the inability to fabricate optically clear anatomical vessel models that realistically replicate the complex morphology of arterial vessels and provide highly resolved flow images of flow tracer particles. The aim of the present work is to introduce an approach for producing optically clear rigid anatomical models that are suitable for PIV analysis using a common 3-D SLA inkjet printing process (using a Formlabs Form 2 3-D printer) and stock clear resin (RS-F2-GPCL-04). By matching the index of refraction (IOR) of the working fluid to the stock clear resin material, and by printing the part in a 45-degree print orientation, a clear anatomical model that allows clear visualization of flow tracer particles can be produced which yields highly resolved flow images for PIV analyses. However, a 45-degree print orientation increases the need for post processing due to an increased amount of printed support material. During post processing, the part must be wet sanded in several steps and surface finished with Novus Plastic Polish 3 Step System to achieve the final surface finish needed to yield high quality flow images. The fabrication methodology of the clear anatomical models is described in detail.
Cold Spray Deposition of Pure Titanium Coating Onto High Strength Substrate With Ultra-High Bond Strength
Authors: M. Jafarlou Davoud , Ferguson Gehn , Nardi Aaron , Champagne Victor , Grosse Ian R.
Published: January 2020

Cold spray (CS) is a relatively new spray coating technology which has opened up a new avenue for deposition of bulk coatings with a thickness in the millimeter range. The unique bonding mechanism of the CS process facilitates deposition of commercially pure titanium (CP-Ti) on a wide range of substrates including high strength alloys. In this paper we present a multi-stage bond coat deposition process using a mixture of ultra-hard ceramic beads and CP-Ti prior to the top CP-Ti coating deposition to produce a coating layer with promising bond strength. In addition, three combinations of the carrier gas temperature (450, 540, and 550 °C), and pressure (2.5 and 3.8 MPa) were considered for maximizing bond strength. The relationship between bond strength and surface roughness was also examined. The shear test results indicated a significant high bond strength of approximately 195 MPa for the gas pressure of 3.8 MPa and temperature of 450 °C owing to the newly introduced bond coat deposition method. The relatively high bond strength is explained by the beneficial effect of multi-stage bond coat prior to the deposition of the bond coat. The results also indicated a tradeoff between bond strength and obtained surface roughness.
Thermal Property Measurements of Si µ-Cantilever Beams Using the Suspended Thermoreflectance Technique
Authors: Sarkar Dipta , Oxandale Samuel W. , Hieber Tyler J. , Baboly M. G. , Leseman Zayd C.
Published: January 2020

Thermoreflectance is a common technique to measure thermal properties of micro/nano devices. Most thermoreflectance techniques use a pump-probe scheme with lasers to heat the sample and analyze the temperature. The limiting characteristics of most of these techniques are that they can probe the temperature at only one spot on the sample, assume a value for either heat capacity or thermal conductivity to find the other, and require a semi-infinite substrate. In this paper, a new technique is described, the Suspended ThermoReflectance (STR) technique, which allows measurement of thermal conductivity by probing multiple points along the length of a suspended micro/nano-scale sample. This technique involves a pump laser for heating the tip of a suspended μ-cantilever Si beam and a probe laser to scan the temperature along the μ-cantilever’s length. Thermal conductivity is obtained by applying the heat diffusion equation for the temperature gradient along the beam length. 2.9 μm thick Si μ-cantilever samples are tested over a range of temperatures from 20–300K. It is found that thermal conductivity of the silicon varies from 28 W/mK to 80 W/mK.
Structural Dynamic Testing Results for Air-Independent Proton Exchange Membrane (PEM) Fuel Cell Technologies for Space Applications
Authors: Gilligan Ryan P. , Jakupca Ian J. , Smith Phillip J. , Bennett William R. , Guzik Monica C. , Kacher Henry
Published: January 2020

In 2016, the National Aeronautics and Space Administration (NASA) Advanced Exploration Systems (AES) project office funded testing at the NASA Glenn Research Center to evaluate the maturity of the Proton Exchange Membrane (PEM) fuel cell technology and its viability for supporting launch vehicle and space applications. This technology evaluation included vibration, reactant purity, and vacuum exposure sensitivity testing. The evaluation process did not include microgravity testing. This paper discusses the vibration sensitivity testing of two air-independent fuel cell stacks provided by different vendors to assess the ability of currently available fuel cell stack hardware to survive the projected random vibrational environment that would be encountered in an upper stage launch vehicle. Baseline performance testing was utilized to quantify stack performance and overboard leak rate at standard atmospheric conditions in order to provide a reference for posttest comparison. Both fuel cell stacks were tested at a random vibration qualification level of 10.4 grms for five minutes in each axis. Low-level sinusoidal sweeps were conducted before and after each random vibration level run to see if any significant change in resonances were detected. Following vibration facility testing, the baseline performance testing was repeated. Test results demonstrated no measurable change in fuel cell electrochemical or mechanical performance, indicating that the two evaluated PEM fuel cell stacks may be suitable for space applications pending microgravity testing.
Numerical Study on the Interfacial Modification Effects of Soy Protein on Poly(Vinylidene Fluoride)
Authors: Zheng Zhuoyuan , Xin Chen , Li Yumeng
Published: January 2020

The application of bio-degradable green materials is a rising global trend during the past decades for the sake of environment protection and sustainable development. Soy protein-based biomaterial is a promising candidate to replace the petroleum-based synthetic materials and was proved to be an effective functional modifier for polymers from our previous studies. Molecular dynamic (MD) simulation is implemented in this study to provide insights in understanding the underlying mechanisms. 11S molecule is chosen as a representative of soy protein, and three different denaturation processes are applied, including heat denaturation at two temperatures and the breaking of disulfide bonds. It is observed that by controlling the denaturation conditions, the hydrophobicity of the protein molecule is manipulated: high temperature denaturation can increase the exposed area of hydrophilic residues; whereas, by breaking the disulfide bonds, the hydrophobic residues of the molecules can be largely exposed. Besides, the mechanisms of using protein as functional modifier to tune the structures of the hydrophobic Poly(vinylidene fluoride) (PVDF) polymer (amorphous and β-crystal phases) are studied. S-S debond protein is found to favor the formation of amorphous PVDF; whereas, high temperature denatured one has stronger interactions with β phase.
CFD Analysis of Flow Structures in a Mixing Chamber
Authors: Cândido Sílvio , Páscoa Marques José , Tomé António , Amorim António , Weber Stefan Karl
Published: January 2020

Special mixing chambers are usually used to perform scientific experiments or for routine industrial production processes. This is the case, typically, of fan mixers in a baffled tank. Mixing chambers comprise, among other alternative elements, two counter-rotating fans at the bottom and top. These will eventually allow a mixing effect on the chamber with an adequate level of uniformity. Herein a computational flow simulation is performed for the mixing conditions of air and SO2 inside the chamber used in the CLOUD experiment, by studying in detail the flow structures and uniformity inside the chamber. This Unsteady Navier-Stokes computation is performed using the kω-SST and SAS turbulence models. A first validation step is performed by using an experimental test case, comprising a T-junction geometry, that performs the mixing of air and N2. Following this validation step a detailed analysis of the flow structures inside the 3D chamber is conducted, and specific insights are given regarding the flow uniformity. A detailed analysis of the computed mixing flow structures for the SST and SAS turbulence models is also described. It is shown that the SAS model captures with more detail the macro and meso-mmixing process with an accuracy of, at most, 6%. This value can be further reduced to values around 2% by resorting to high density meshes, with the associated computational burden.
Experimental Investigation of Spiral Wound Module Under Pressure Retarded Osmosis Process
Authors: Vives Luis , Elsharqawy Mostafa H. , Quiñones-Bolaños Edgar
Published: January 2020

The performance of a spiral wound module operating under pressure retarded osmosis (PRO) is measured experimentally with a feed water back pressure. The module has a diameter of 0.1 m, a length of 1.02 m, and total membrane surface area of 7.45 m2 capsulated in a stainless-steel pressure vessel. The module is commercially designed for a reverse osmosis (RO) system however, a feed water outlet is added, and a back pressure is applied to adapt it for the PRO process. The experimental results of the spiral wound PRO module with a back pressure in the feed water side showed low power density values (about 0.35 W/m2) compared with those commonly found in the literature, demonstrating the geometric inefficiency of RO modules for the PRO process.
The Effect of Time Delay on 3D Printed Part Strength
Authors: Gay Jasmine , Moore Carl , Pollard Marquese , Dickens Tarik , Wang Hui
Published: January 2020

We are investigating the impact on 3D printed part strength when the extruder is positioned using articulated robotic arms in place of a traditional x-y gantry-style system. One of our printer designs is called the DeXter printer [1] which uses two selective compliance assembly robotic arms (SCARA) to position dual extruders. An advantage of using dual robotic arms is that two extruders can move independently drastically reducing build times, or the second arm can perform additional operations like segment stimulation during the build process [2]. In either case the arms require a collision avoidance process to prevent them from colliding in the part space. A possible drawback of the collision avoidance requirement is that it can result in a time delay along some sections of the layer which, due to cooling, could have adverse effects on the part strength. This research aims to determine how this cooling time will affect the strength of ABS extruded parts.

We performed tensile tests on 3D printed part samples for which we altered the g-code to produce a variable time delay during the printing process. Our control sample had a zero-dwell time, and as we increased dwell time we found that the ultimate tensile strength (UTS) did decrease.
Combining FEA and Field Measurement Techniques for Dynamic Machinery Foundation Design
Authors: Cunningham Seth , White Benjamin A. , Poerner Nathan W.
Published: January 2020

Proper foundation design is an essential component in the design process of many types of rotating machinery. Most foundations are designed for static loading, however dynamic foundation design is often overlooked or considered a secondary check. Failing to consider the dynamics of the foundation during the design phase can result in excessive machinery vibrations resulting in failures, forced shutdowns, and expensive in-situ repairs. Foundation dynamics are commonly assessed using finite element analysis (FEA) during the design phase with modal and forced response analyses; however the interactions of machinery, piping, foundation, and soil create a potentially nonlinear system with many degrees-of-freedom. In many applications, it is necessary to design the mechanical natural frequencies of the foundation to avoid excitation mechanisms of the machinery. With modern variable speed machines, accurate prediction of the mechanical natural frequencies is often required to place them in narrow frequency bands between operating orders. These systems are inherently difficult to accurately model, however combining FEA modeling with field measurement techniques allows the possibility of field “tunable” foundation designs. For example, pile foundations can be designed with alternative pile configurations to be connected during commissioning based on the results of modal testing. Modal and vibration data collected on-site can also be used to calibrate the frequencies and mode shapes predicted by the model. This calibrated model is then used to evaluate the effects of proposed changes to the skid and suggest modifications to fix or reduce the problems in existing machinery foundations.
On the Global Dynamics of Complex Networks
Authors: Yang Chun-Lin , Suh C. Steve
Published: January 2020

Complex networks are nonlinear dynamic systems. The dynamics of a complex network is the local dynamics of all ensemble at the microscopic level, coupled with the global dynamics at the macroscopic level. At the macroscopic level, the connections between each ensemble contain energy that couples the ensembles to evolve toward the state of consensus. Both the local and global dynamics are nonlinear and time-dependent. The level of coupling between each ensemble pair is affected by the energy that characterizes the connection of each ensemble pair. As the connection energy is time-dependent, consequently, the relation between each ensemble pair is dynamic as well. Since the energy of each connection can be different, the dynamic distribution of the connection energy is a key factor for defining the global dynamics of a complex network. While statistical entropy can be applied to define the distribution of energy among all connections, the global dynamics of a complex network can be defined by regulating the entropy of the connection energy distribution. As the global dynamics of a complex network can be defined by entropy, the correlation between statistical entropy and network dynamics is investigated.
Numerical Evaluation of Recalling Elasticity due to Surface Roughness by Finite Element Modeling of Human Skin
Authors: Yamamoto Tomohisa , Sakuma Atsushi
Published: January 2020

Among human sensations, tactile perception has an important role in physics and in living comfortably. It is already known that surface roughness greatly affects the feel of solid objects, but the mechanics of the relationship between feeling and physics, as well as their effects, are difficult to determine. This study, aims to clarify the numerical relationship between elastic tactile perception and surface roughness of a rigid body by designing various products with surfaces comfortable to touch. The finite element method (FEM) has been adopted for this clarification, and a numerical model of human skin with 3 layers, epidermis, dermis, and subcutaneous, has been developed to discuss the mechanical effects of touch movement. This skin model is used to evaluate the distribution of skin deformations during the process of touch movement, and the analysis of the tactile perception is done by discussing the distribution change due to touching objects. The change in distribution of deformation is mainly discussed in terms of pressure under the epidermis, and various patterns of distribution are inspected by changing the diameters and pitch ratio of a uniformly spread ball used as a plain surface. By comparing the relationship between distributions of rigid and elastic surfaces, similar distributions of pressure in the skin model were observed, and the relationships of the distribution are summarized to solve the mechanics of touch feeling. In this summarization, the maximum pressure and the maximum gradient of pressure distribution are adopted as parameters for the analysis. The analysis shows that it is numerically possible to represent the elasticity recalled by the rigid surface from its relationship with the elastic surface when they have the same maximum pressure and maximum inclination of pressure. The importance of maximum inclination of pressure for touch feeling is also shown here.
Experimental Determination of Axial Viscoelasticity of Braided Steel Cables Through the Design of a Special Purpose Machine
Authors: Zamora-Garcia Diego A. , Acosta-Carrion Luis Miguel , Corona-Lira Ma. Pilar , Ramirez-Reivich Alejandro C.
Published: January 2020

Braided steel cables have the potential for improving the mechanisms providing them several advantages in comparison with rigid elements. Nevertheless, a limitation in the use of cable mechanism is that due to the inherent flexibility, the problem of vibration arises. In this research, we investigate the axial viscoelastic behavior of 1/32″ braided steel cables. The essential idea is to determine the parameters of elasticity (k) and viscosity (b) as a function of the length of the cable in its axial direction. It was achieved through the design and construction of a test bench and the design of an experiment. The test bench is a free vibration particular design machine. One end of the cable is fixed to the structure, and in the other end, a load is attached. Then, the load is released, and the free vibration of the cable in the axial direction is registered. The factor of the experiment is the length of the cable. There are six levels, and these were repeated four times. We demonstrated that the braided steel cables have a viscoelastic behavior like a Kelvin-Voigt. Also, we found a relation between the effective length of the cables and the parameters of elasticity and viscosity.
Shoulder Proprioception Device (S.P.D.): A Novel Design for Measuring Shoulder Joint Proprioception
Authors: Schnipke Jeremy R. , Rounds Thomas G. , Sroka Jacob P. , Lowe Zachary B. , Freisinger Gregory M. , Nowicki Margaret A. , Cameron Kenneth L. , Hotaling Brittany R. , Westrick Richard B.
Published: January 2020

Shoulder injuries are a serious and costly issue, particularly in physically intensive professions like athletics and the military. Previous data indicates a dangerous feedback mechanism between reduced shoulder proprioception due to previous injury and higher probability of re-injury due to reduced proprioception. It is therefore important for organizations to possess a device that can accurately and efficiently evaluate and track an individual’s shoulder proprioception, especially following injury. Existing technologies that fill this role are generally impractical or do not quantify proprioception to the necessary levels of accuracy. The Shoulder Proprioception Device (SPD) therefore strives to measure and quantify three-dimensional shoulder proprioception in a highly accurate, user-friendly, and cost-effective manner. This device employs two Inertial Measurement Units (IMUs) with nine degrees-of-freedom attached to the lateral and frontal sides of the upper arm. These sensors are connected to a microcontroller board with a touch screen and datalogger. The screen displays the shoulder angles in real-time and allows the user to store discrete angle positions for further analysis through the data-logger. The system is compact (390 cubic centimeter volume), light (0.34 kilograms), and cost effective ($179 per unit). This device is capable of measuring, in a total procedural time of seven minutes, shoulder proprioception within two degrees of accuracy along the three anatomical planes of motion: sagittal flexion/extension, frontal abduction/adduction, and transverse abduction/adduction. This device is able to both aid upper extremity research and provide data to those making return to duty decisions following injury.
Recycling Li-Ion Batteries: Robotic Disassembly of Electric Vehicle Battery Systems
Authors: Kay Ian , Esmaeeli Roja , Hashemi Seyed Reza , Mahajan Ajay , Farhad Siamak
Published: January 2020

This paper presents the application of robotics for the disassembly of electric vehicle lithium-ion battery (LIB) packs for the purpose of recycling. Electric vehicle battery systems can be expensive and dangerous to disassemble, therefore making it cost inefficient to recycle them currently. Dangers associated with high voltage and thermal runaway make a robotic system suitable for this task, as the danger to technicians or workers is significantly reduced, and the cost to operate a robotic system would be potentially less expensive over the robots lifetime. The proposed method allows for the automated or semi-automated disassembly of electric vehicle LIB packs for the purpose of recycling. In order to understand the process, technicians were studied during the disassembly process, and the modes and operations were recorded. Various modes of interacting with the battery module were chosen and broken down into gripping and cutting operations. Operations involving cutting and gripping were chosen for experimentation, and custom end of arm tooling was designed for use in the disassembly process. Path planning was performed offline in both MATLAB/Simulink and ROBOGUIDE, and the simulation results were used to program the robot for experimental validation.
Plasma Decomposition of Carbon Dioxide: Simulations and Experiments
Authors: Wright Kamau , Galvez Robert
Published: January 2020

Simulations and experiments are conducted to model, simulate, test and demonstrate the effect of plasma discharges on decomposition of carbon dioxide (CO2). A pin-to-plane discharge is employed in gas samples containing CO2. A high voltage plasma system is used which was previously shown to be able to decrease CO2 concentration in gas samples. The discharge is modeled and described, including monitoring electrical parameters such as current and voltage. The present study investigated plasma decomposition of carbon dioxide experimentally, and through simulation. A plasma micro-discharge was utilized to better understand plasma-CO2 interactions. Enhancements are suggested to help increase the efficiency and yield of the plasma-CO2 decomposition process. Gas samples are analyzed over time using a CO2 meter.
Dynamic Brake Force Distribution for Heavy Commercial Road Vehicles Using Wheel Slip Regulation
Authors: Challa Akhil , Devika K. B. , Subramanian Shankar C. , Vivekanandan Gunasekaran , Sivaram Sriram
Published: January 2020

Wheel lock is an undesired phenomenon in Heavy Commercial Road Vehicles (HCRVs) and wheel slip control within a desired range is of crucial importance for stable and effective braking. This study proposes a framework to distribute brake force dynamically between the front and rear wheels, primarily to avoid instability by preventing wheel lock. Further, it ensures the maximum utilization of the available traction force at the tire-road interface that varies during the course of braking due to factors like load transfer. Wheel slip regulation provides an approach to maximize braking performance that subsumes the effects of varying road, load and braking conditions that occur during vehicle deceleration. The methodology proposed consists of a wheel slip controller that calculates the required brake force distribution parameters, which are then provided to the brake controller for control action. Sliding mode control was used because of the nonlinear nature of the longitudinal vehicle dynamic model considered and for robustness towards different parameter variations. The algorithm was implemented on a Hardware-in-Loop test setup consisting of a pneumatic air brake system, interfaced with IPG-TruckMaker® (a vehicle dynamic simulation software), and co-simulated with MATLAB-Simulink®. It was found that this algorithm improved the braking performance of a HCRV both in terms of stopping distance and vehicle stability.
Sustainable Waste Water Treatment Using Solar Energy by Heat Localization Through Porous Media
Authors: Jaladi Divya , Languri Ethan , Piras Bob
Published: January 2020

Efficient utilization of solar energy can be a sustainable technology for wastewater treatment and desalination of seawater. However, the methods and optical concentrators used in the current process of treatments are hindering the application due to its high cost and low efficiencies. Here, we demonstrate a scalable approach for treating fertilized wastewater using acid treated carbon foam of different porosities at 1 Sun (1 kW/m2) solar illuminations by avoiding heat losses. This solar heat-localized distillation approach may be used independently or in connection with an existing active distillation method. In this approach, we incorporate the heat localization process to accelerate the evaporation rates of the liquid and then condense the vapor, thereby collecting distilled liquid. Various potential applications of this method include seawater desalination and water reclamation. In this paper, we will report the evaporation rates of fertilized water used in hydroponic greenhouses to analyze the distillation rate and quality of water obtained from evaporating and condensing for reusability.
Effect of Build Direction in Direct Metal Laser Sintering (DMLS) of Inconel 718 on Microstructure and Mechanical Behavior
Authors: Alya Sachin , Vundru Chaitanya , Singh Ramesh , Thool Khushahal , Samajdar Indradev , Saigal Anil
Published: January 2020

Additive manufacturing (AM) technology is gaining enormous popularity in the manufacturing industries. The continuous improvements made in the AM processes features development of 3D metallic prototypes as well as fully functional end-use components. Direct Metal Laser Sintering (DMLS) is a pre-placed powder bed based technique, in which a thin layer of powder is place over the build tray and the areas need to be sintered are exposed to the laser. In the current work the microstructural and mechanical behavior of Inconel 718 parts produced by DMLS are investigated. As the DMLS produces parts in a layer by layer fashion, the orientation of parts with respect to the build direction is an important criterion. Microstructure and mechanical properties of the produce differs depending upon the orientation. This paper emphasize on the variation of grain sizes and grain orientations developed in the components built with different orientations. Another common issue with the additive manufacturing is the development of the residual stresses in the components arising due to the differential thermal gradients experienced during processing. The variation of the residual stress generated in the produced parts has also been characterized and modeled.
Mechanical Behavior of Lattice Structures Fabricated by Direct Light Processing With Compression Testing and Size Optimization of Unit Cells
Authors: Peto Marinela , Ramirez-Cedillo Erick , Uddin Mohammad J. , Rodriguez Ciro A. , Siller Hector R.
Published: January 2020

Lattice structures used for medical implants offer advantages related to weight reduction, osseointegration, and minimization of stress shielding. This paper intends to study and to compare the mechanical behavior of three different lattice structures: tetrahedral vertex centroid (TVC), hexagonal prism vertex centroid (HPVC), and cubic diamond (CD), that are designed to be incorporated in a shoulder hemiprosthesis. The unit cell configurations were generated using nTopology Element Pro software with a uniform strut thickness of 0.5 mm. Fifteen cuboid samples of 25mm × 25mm × 15 mm, five for each unit cell configuration, were additively manufactured using Direct Light Printing (DLP) technology with a layer height of 50μm and a XY resolution of 73μm. The mechanical behavior of the 3D printed lattice structures was examined by performing mechanical compression testing. E-silicone (methacrylated silicone) was used for the fabrication of samples, and its mechanical properties were obtained from experimental tensile testing of dog-bone samples. A methodology for size optimization of lattice unit cells is provided, and the optimization is achieved using nTopology Element Pro software. The generated results are analyzed, and the HPVC configuration is selected to be incorporated in the further design of prosthesis for bone cancer patients.
Laser Ablation Tomography for 3D Tissue Imaging and Analysis
Authors: Lanba Asheesh , Hall Benjamin
Published: January 2020

Laser ablation tomography (LATscan) can produce 3D tissue models at micron-scale resolution within a few minutes, being amenable to high-throughput applications. The RGB images obtained from LATscan allow for enhanced and accurate feature segmentation and quantification. The technology uses an ultrafast, ultraviolet pulsed laser to continually ablate a sample as it is fed into the laser ablation plane. The ultrafast nature of the laser pushes the process into being athermal, minimizing structural damage to the material being imaged. The surfaces are imaged at the ablation plane. Precise motion control allows for sub-micron separation between consecutive images. The ablation results in color images due to the ultraviolet laser inducing multi-spectral fluorescence. The LATscan system can also be programmed allow for co-registration of cross-sections under different lighting conditions. The images are then stacked, further processed and reconstructed into volume renderings with a voxel size that can go down to 0.2 μm3 for further analysis and virtual dissection. Image processing allows for the 3D visualization and quantification of desired anatomy. LATscan has been successfully applied in the fields of plant science, entomology and materials science. It shows great promise for biomedical imaging and tissue analysis, and this paper presents a few results from the LATscan imaging of murine tissue. Various murine organs have been imaged, including the gut, kidney, and brain (inside the skull). The imaging and analysis combined have the potential to provide pathologists, researchers and diagnosticians with insights and solutions not available to them before.
Impact of emergency care centralisation on mortality and efficiency: a retrospective service evaluation
Authors: Price Christopher , McCarthy Stephen , Bate Angela , McMeekin Peter
Published: January 2020

Objective

Evidence favours centralisation of emergency care for specific conditions, but it remains unclear whether broader implementation improves outcomes and efficiency. Routine healthcare data examined consolidation of three district general hospitals with mixed medical admission units (MAU) into a single high-volume site directing patients from the ED to specialty wards with consultant presence from 08:00 to 20:00.

Methods

Consecutive unscheduled adult index admissions from matching postcode areas were identified retrospectively in Hospital Episode Statistics over a 3-year period: precentralisation baseline (from 16 June 2014 to 15 June 2015; n=18 586), year 1 postcentralisation (from 16 June 2015 to 15 June 2016; n=16 126) and year 2 postcentralisation (from 16 June 2016 to 15 June 2017; n=17 727). Logistic regression including key demographic covariates compared baseline with year 1 and year 2 probabilities of mortality and daily discharge until day 60 after admission and readmission within 60 days of discharge.

Results

Relative to baseline, admission postcentralisation was associated with favourable OR (95% CI) for day 60 mortality (year 1: 0.95 (0.88 to 1.02), p=0.18; year 2: 0.94 (0.91 to 0.97), p<0.01), mainly among patients aged 80+ years (year 1: 0.88 (0.79 to 0.97); year 2: 0.91 (0.87 to 0.96)). The probability of being discharged alive on any day since admission increased (year 1: 1.07 (1.04 to 1.10), p<0.01; year 2: 1.04 (1.02 to 1.05), p<0.01) and the risk of readmission decreased (year 1: 0.90 (0.87 to 0.94), p<0.01; year 2: 0.92 (0.90 to 0.94), p<0.01).

Conclusion

A centralised site providing early specialist care was associated with improved short-term outcomes and efficiency relative to lower volume ED admitting to MAU, particularly for older patients.
A man with intolerant vomiting
Authors: Liang Ya-Chin , Tsai Tou-Yuan
Published: January 2020

Case presentation

A 57-year-old man was in a healthy state until 6 hours before presenting to the emergency department, when he suffered from more than 10 episodes of vomiting after a large meal at lunchtime. On physical examination, vital signs were unremarkable. Tenderness was noted over the epigastrium on palpation. Point-of-care ultrasound (POCUS) of the abdomen is shown in figure 1 and online supplementary video 1.

Supplementary video

Figure 1

Transverse (A) and longitudinal (B) ultrasonography of the epigastrium.

Question

What is the most likely diagnosis?

Hypertrophic pylorus stenosis

Aortic dissection

Superior mesentery artery (SMA) syndrome

Volvulus

For answer see page 2
How should the ‘privilege’ in therapeutic privilege be conceived when considering the decision-making process for patients with borderline capacity?
Authors: Menon Sumytra , Entwistle Vikki , Campbell Alastair Vincent , van Delden Johannes J M
Published: January 2020

Therapeutic privilege (TP) is a defence that may be available to doctors who fail to disclose to the patient relevant information when seeking informed consent for treatment if they have a reasonable belief that providing that information would likely cause the patient concerned serious physical or mental harm. In a landmark judgement, the Singapore Court of Appeal introduced a novel interpretation of TP, identifying circumstances in which it might be used with patients who did not strictly lack capacity but might be inclined to refuse recommended treatments. In this paper, we explore the conceptual and practical challenges of this novel interpretation of TP. We propose that more emphasis should be placed on forms of shared and supported decision-making that foster the autonomy of patients with compromised mental capacity while being mindful of the need to safeguard their well-being. The kind of privilege that doctors might need to invoke is one of time and supportive expertise to ensure a flexible, responsive approach calibrated to the individual patients’ needs. The provision of such service would extinguish the need for the novel TP proposed by the Singapore Court of Appeal.
Above the Line, Below the Line
Authors: Cook Richard I.
Published: January 2020

Knowledge and understanding of below-the-line structure and function are continuously in flux. Near-constant effort is required to calibrate and refresh the understanding of the workings, dependencies, limitations, and capabilities of what is present there. In this dynamic situation no individual or group can ever know the system state. Instead, individuals and groups must be content with partial, fragmented mental models that require more or less constant updating and adjustment if they are to be useful.
Information Disclosure and Privacy Paradox
Authors: Aivazpour Zahra , Rao V. Srinivasan (Chino)
Published: January 2020

Self-disclosure of personal information is generally accepted as a security risk. Nonetheless, many individuals who are concerned about their privacy will often voluntarily reveal information to others. This inconsistency between individuals' expressed privacy concern and the willingness to divulge personal information is referred to as privacy paradox. Several arguments have been proposed to explain the inconsistency. One set of arguments centers around the possible effects of differences in personality characteristics, such as the Big Five factors. In the current article, we examine the role of one personality characteristic, impulsivity, in explaining the relationship between privacy concern and information disclosure. We report the results of a survey-based study that consisted of two hundred and forty-two (242) usable responses from subjects recruited on Amazon Mechanical Turk. The results show that one of the three dimensions of impulsivity, motor impulsivity, directly influences the extent of information disclosure and also moderates the relationship between privacy concern and information disclosure. Furthermore, our study shows impulsivity explains more variance in information disclosure than explained by the Big Five factors only.
It's Not Just About the Product
Authors: Becker Moritz , Matt Christian , Hess Thomas
Published: January 2020

Individuals' disclosure of personal health information (PHI) can hold substantial benefits for both users and providers, but users are often reluctant to disclose, even if they gain benefits such as better personalization. While previous research has dealt with message framing and information quality in a health-related context, these factors have been observed separately. To our best knowledge, we are among the first to have examined both factors (attribute framing and argument strength) and their interactions concerning PHI disclosure. Thus, we conducted a web-based experiment with 529 participants to examine the impacts of two persuasive message techniques (attribute framing and argument strength) on individuals' PHI disclosure. We reveal that individuals tend to disclose more PHI when they experience persuasive messages with more positively framed health wearable (HW) attributes or messages with higher argument strength based on the reasons for the data collection. We enable researchers to uncover the impacts of persuasive messages in highly sensitive data environments and provide practitioners with workable suggestions on how to affect individuals' PHI disclosure behaviors.
Looking Beyond GINA: Policy Approaches to Address Genetic Discrimination
Authors: Joly Yann , Dupras Charles , Pinkesz Miriam , Tovino Stacey A. , Rothstein Mark A.
Published: January 2020

Concerns about genetic discrimination (GD) often surface when discussing research and innovation in genetics. Over recent decades, countries around the world have attempted to address GD using various policy measures. In this article, we survey these approaches and provide a critical commentary on their advantages and disadvantages. Our examination begins with regions featuring extensive policy-making activities (North America and Europe), followed by regions with moderate policy-making activities (Australia, Asia, and South America) and regions with minimal policy-making activities (the Middle East and Africa). Our analysis then turns to emerging issues regarding genetic testing and GD, including the expansion of multiomics sciences and direct-to-consumer genetic tests outside the health context. We additionally survey the shortcomings of current normative approaches addressing GD. Finally, we conclude by highlighting the evolving nature of GD and the need for more innovative policy-making in this area.
Postnatal leptin surge is critical for the transient induction of the developmental beige adipocytes in mice
Authors: Wu Rui , Yu Wenyan , Fu Lizhi , Li Fenfen , Jing Jia , Cui Xin , Wang Shirong , Cao Qiang , Xue Bingzhong , Shi Hang
Published: January 2020

Beige adipocytes have become a promising therapeutic target to combat obesity. Our senior author Dr. B. Xue previously discovered a transient but significant induction of beige adipocytes in mice during early postnatal development, which peaked at postnatal day (P) 20 and then disappeared thereafter. However, the physiological mechanism underlying the transient induction of the developmental beige cells remains mystery. Interestingly, there exists a postnatal surge of leptin in mice at P10 before the appearance of the developmental beige adipocytes. Given the neurotropic effect of leptin during neuronal development and its role in activating the sympathetic nervous system (SNS), we tested the hypothesis that postnatal leptin surge is required for the transient induction of developmental beige adipocytes through sympathetic innervation. Unlike wild-type (WT) mice that were able to acquire the developmentally induced beige adipocytes at P20, ob/ob mice had much less uncoupling protein 1 (UCP1)-positive multilocular cells in inguinal white adipose tissue at the same age. This was consistent with reduced expression of UCP1 mRNA and protein levels in white fat of ob/ob mice. In contrast, daily injection of ob/ob mice with leptin between P8 and P16, mimicking the postnatal leptin surge, largely rescued the ability of these mice to acquire the developmentally induced beige adipocytes at P20, which was associated with enhanced sympathetic nerve innervation assessed by whole mount adipose tissue immunostaining of tyrosine hydroxylase. Our data demonstrate that the postnatal leptin surge is essential for the developmentally induced beige adipocyte formation in mice, possibly through increasing sympathetic nerve innervation.
Upregulated phospholipase D activity toward glycosylphosphatidylinositol-anchored proteins in micelle-like serum complexes in metabolically deranged rats and humans
Authors: Müller Günter A. , Tschöp Matthias H. , Müller Timo D.
Published: January 2020

Glycosylphosphatidylinositol-anchored proteins (GPI-AP) with the complete glycolipid anchor attached have previously been shown to be released from the outer plasma membrane leaflet of rat adipocytes in positive correlation to cell size and blood glucose/insulin levels of the donor rats. Furthermore, they are present in rat and human serum, however, at amounts that are lower in insulin-resistant/obese rats compared with normal ones. These findings prompted further evaluation of the potential of full-length GPI-AP for the prediction and stratification of metabolically deranged states. A comparison of the signatures of horizontal surface acoustic waves that were generated by full-length GPI-AP in the course of their specific capture by and subsequent dissociation from a chip-based sensor between those from rat serum and those reconstituted into lipidic structures strongly argues for expression of full-length GPI-AP in serum in micelle-like complexes in concert with phospholipids, lysophospholipids, and cholesterol. Both the reconstituted and the rat serum complexes were highly sensitive toward mechanical forces, such as vibration. Furthermore, full-length GPI-AP reconstituted into micelle-like complexes represented efficient substrates for cleavage by serum glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD). These findings raised the possibility that the upregulated release of full-length GPI-AP into micelle-like serum complexes from metabolically deranged cells is compensated by elevated GPI-PLD activity. In fact, serum GPI-PLD activity toward full-length GPI-AP in micelle-like complexes, but not in detergent micelles, was positively correlated to early states of insulin resistance and obesity in genetic and diet-induced rat models as well as to the body weight in humans. Moreover, the differences in the degradation of GPI-AP in micelle-like complexes were found to rely in part on the interaction of serum GPI-PLD with an activating serum factor. These data suggest that serum GPI-PLD activity measured with GPI-AP in micelle-like complexes is indicative of enhanced release of full-length GPI-AP from relevant tissues into the circulation as a consequence of early metabolic derangement in rats and humans.
High-protein diet accelerates diabetes and kidney disease in the BTBRob/ob mouse
Authors: Björnson Granqvist Anna , Ericsson Anette , Sanchez José , Tonelius Pernilla , William-Olsson Lena , Dahlqvist Ulrika , Andersson Ann-Katrin , Tesan Tomic Tajana , Hudkins Kelly , Alpers Charles E. , Pellegrini Giovanni , Söderberg Magnus
Published: January 2020

There is a need for improved animal models that better translate to human kidney disease to predict outcome of pharmacological effects in the patient. The diabetic BTBR ob/ob mouse model mimics key features of early diabetic nephropathy in humans, but with chronic injury limited to glomeruli. To explore if we could induce an accelerated and more advanced disease phenotype that closer translates to human disease, we challenged BTBR ob/ob mice with a high-protein diet (HPD; 30%) and followed the progression of metabolic and renal changes up to 20 wk of age. Animals on the HPD showed enhanced metabolic derangements, evidenced by further increased levels of glucose, HbA1C, cholesterol, and alanine aminotransferase. The urinary albumin-to-creatinine ratio was markedly increased with a 53-fold change compared with lean controls, whereas BTBR ob/ob mice on the standard diet only presented an 8-fold change. HPD resulted in more advanced mesangial expansion already at 14 wk of age compared with BTBR ob/ob mice on the standard diet and also aggravated glomerular pathology as well as interstitial fibrosis. Gene expression analysis revealed that HPD triggered expression of markers of fibrosis and inflammation in the kidney and increased oxidative stress markers in urine. This study showed that HPD significantly aggravated renal injury in BTBR ob/ob mice by further advancing albuminuria, glomerular, and tubulointerstitial pathology by 20 wk of age. This mouse model offers closer translation to humans and enables exploration of new end points for pharmacological efficacy studies that also holds promise to shorten study length.