bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerodynamics, Stability and Control Analysis of Tactical Solar Power UAV
Authors: Kampoon J , Jiajan W , Klongtrujrok J
Published: July 2020

This paper addresses the fundamental aerodynamics, stability, and control analysis of a solar power Unmanned Aerial Vehicle (UAV) as a part of the preliminary design stage. The tactical solar-powered UAV addressed in this paper is primarily developed for intelligence, surveillance, and reconnaissance (ISR) missions at low altitude. Moreover, such design also has a dual-use capability, which could be utilized in both military and civilian domains. The aerodynamic characteristics of the UAV are obtained from both computational fluid dynamics analysis technique and the wind-tunnel testing at the design operating Reynolds number ranging from 1x105 – 4.5x105. The fundamental aerodynamics coefficient consists of lift, drag, and pitching moment variations versus the angle of attack. The stability and control analysis was carried out based on the small disturbance theory in correlation with the XFLR5 software. The results show that the tactical solar power UAV design could achieve high aerodynamic efficiency at a 4-degree angle of attack which is corresponding to the lift-to-drag ratio of 20.05. Also, the analysis results confirm that the design possesses positive static and dynamic stability at the design cruise flight condition.
Influence of the trailing edge shape on the aerodynamic characteristics of an airfoil at low Re number using RANS
Authors: Perrin R. , Rattanasiri P. , Lamballais E. , Yooyen S.
Published: July 2020

Recent studies have demonstrated that periodic spanwise modifications of the Trailing Edge of an airfoil can significantly reduce the noise produced and can also increase its aerodynamic performances. This study aims to analyse the effects of such modifications on the aerodynamic performances of a profile by numerical simulation, with a particular emphasis on low Reynolds numbers typical of Unmanned Aerial Vehicles, Micro Aerial Vehicle, and/or small wind turbines. In the range of Re numbers considered here, the flow presents laminar separation eventually followed by transition and reattachment (depending on Reynolds number, Angle of Attack and Free Stream Turbulence).

As the standard for industrial applications is still the RANS approach, thanks to its moderate computational cost, this approach is considered here and a first step consists in evaluating the ability of recently proposed transition models (Menter, 2015; Ge, 2014; Kubacki, 2016) to predict the characteristics of the flow for such geometries. A baseline NACA0012 profile is considered, together with modified Trailing Edges (blunt and serrated). Simulations are performed using Code_Saturne (2nd order finite volume), and the influence of the Free Stream Turbulence, Angle of Attack, and Reynolds number on the aerodynamics performances is examined. The results are compared with data from the literature.
Flow Simulations of Modified Diffuser Augmented Wind Turbine
Authors: Kannan Thangavelu Saravana , Goh Leong Wan Timothy , Piraiarasi C
Published: July 2020

In order for wind technology to compete with conventional sources of energy, in terms of energy production costs, researchers are working on different ways to increase the energy density in wind. Development of wind power augmentation system is one of the most promising concepts in this field. The main objective of this research is to propose a new diffuser design for Diffuser Augmented Wind Turbine (DAWT) by introducing air vents and vortex generators. This study also investigates the effect of wind velocity and air pressure on the proposed modified diffuser to develop a suitable diffuser for DAWT. The purpose of this modified diffuser is to create a low-pressure region in the centre of the diffuser to increase the inlet mass flow rate. Three modified designs were developed and were simulated using CFD techniques. Results showed an outstanding increment in wind speed, which is 8.56 m/s (2.14 times increment), over the 4 m/s initial wind speed in a modified diffuser (Model 3 Air vents with splitter). This modified diffuser is based on the parameters: rotor diameter (D) = 500 mm, diffuser length (L) = 1000 mm, diffuser open-angle (θ) = 12º, flange size = 221.73 mm and inner splitter with 14º open-angle (α).
Modelling Method Investigation of Drive and Motor for an Industrial Overhead Crane
Authors: Suksabai Nattapong , Waikoonvet Jatuporn , Chuckpaiwong Ittichote
Published: July 2020

Overhead cranes are commonly used to carry heavy objects from one place to another in a workspace. In common, 3-phase electric drive and induction motor are selected to drive a crane in three dimensions. Many mathematical models of a three- dimensional overhead crane were previously derived by energy equation to describe a relationship of applied force and crane movement. The problem was that the applied force could not be used for controlling most overhead crane systems whose motors were commonly controlled by velocity commands. Although, this problem was solved by creating an empirical model which contains the three functions: switch, rate limiter and linear second order, the further investigation and validation was still required. In this paper, the model of drives and motors of an overhead crane was investigated and validated by experiments using an industrial-grade 1-ton overhead crane. A unit step input of velocity command and actual velocity were used as data to create an empirical model. The model performance was experimentally evaluated by comparing with actual velocity and position of each time step. The discussion was also provided at the end.
Simulated Braking Performance Comparison of an Electric Drum Brake and a Hydraulic Drum Brake Systems
Authors: Kittirattanachai A , Watechagit S
Published: July 2020

The most important safety equipment for the operation of a vehicle is the brake equipment. This research attempts to develop an all-electric braking system that can be used in an electric vehicle. Since the drum brake requires lower actuation input than the disk brake in order to deliver the same amount of braking force. It seems logical to be used in the electric vehicle as far as minimizing energy usage is concerned. The proposed electric drum brake system conceptually is not new as it has been used as a trailer brake for a tractor-trailer vehicle. Adopting the trailer brake for a passenger vehicle requires proper downsizing and different braking control scheme. This paper presents the modelling and simulation results of the proposed electric drum brake. The main interest is its braking performance which can be investigated by the brake force profile or the brake force characteristic. The results are compared with the braking performance of the conventional hydraulic drum brake system which is using validated data from the literature. The simulation results show that the braking force of the electric drum brake system is two times higher than that is of the hydraulic drum brake system subjected to the same actuation force. The results from this paper will be valuable for the development of the controller in the future.
A Force-controlled Three-fnger Prosthetic Hand via Three-Dimensional Printing
Authors: Chalong Wattana , Tanjaipet Settanan , Eurcherdkul Peeraphat , Chuckpaiwong Ittichote
Published: July 2020

This paper presents the development of a force-controlled 3D-printed prosthetic hand commanded by surface electromyography. The prosthetic hand used force control to pick up a 600-ml water bottle without any damages. Two experiments were carried out to determine the model of the system. The first one is to determine the relationship between the voltage of electromyography and the handgrip force. The second one is to determine the relationship between the current of DC motor and the water bottle grip force. Feedback control was used to control the gripping force. The prosthetic hand was tested for its gripping water bottles. Percentage of success in holding water bottle with a closed bottle cap is 90% of all brands. With opened bottles, the prosthetic hand cannot hold bottles from one brand, which is made of a soft plastic shell. The remaining brands of water bottle have a percentage of success above 90%.
LQR-Based Stabilization and Position Control of a Mobile Double Inverted Pendulum
Authors: Ratnayake D T , Parnichkun M
Published: July 2020

The double inverted pendulum is a system that can be used efficiently to test and validate the performance of control algorithms because of its instability and the many degrees of freedom system. The paper presents the design and development of a unique mobile double inverted pendulum system. LQR is applied for the balancing control of both pendulums and position control of the mobile platform of the system. Both simulations and experiments are conducted to evaluate the system performance.
Development of Vertical Articulated Robot Deburring System by Using Sensor Feedback
Authors: Kakoi Hiroki , Yanagihara Kiyoshi , Akashi Koji , Tsuchiya Kensuke
Published: July 2020

Demand of customer for higher quality of product is increasing. Number of skilled engineers, however, is chronically lacking in worldwide. Thus, the change of environment of production drives robotization of hand-finishing process recently. This study is about Robotization of deburring by means of a hand grinder, which is one of the hand finishing tools. Basically, in robotization of the hand-finishing process, teaching operation is selected for the programming of the tool path of the robotic arm. In this study, however, a vertically articulated robot equipped with various sensors is developed for the robotic deburring system, the feasibility of fully automated robotic deburring by using hand grinder is investigated.
Improvement of Background Oriented Schlieren Method Focused on Amplitude of Wavelet Transform
Authors: Koki Miyaoku , Hiroshi Fukuoka , Shigeto Nakamura , Masanori Yao , Kazuki Hiro
Published: July 2020

The BOS method is a visualization method of density variation in the flow field. This method is simpler and cheaper to visualize than the Schlieren method. The primary purpose of this study is to propose WA-BOS (a simpler BOS method focusing on the amplitude of the Wavelet transform). Output images by WA-BOS and WP-BOS (BOS method focused on the phase of the Wavelet transform) and the Schlieren image were compared to verify the validity of the output images. Also, output images by the captured image lost periodic information partially were verified, in order to confirm the validity of the image processing for the deviation out of the domain of phase. The targets of visualization are the supersonic jet and the shock wave ejected from the shock tube. The measurement system consists of an LED, a sine pattern background image and a high-speed camera. As a result, the supersonic jet and the shock wave ejected from the shock tube are visible in the visualized image that was obtained by WA-BOS and WP-BOS. Moreover, it is found that WA-BOS can visualize a supersonic phenomenon without containing an error.
Numerical Simulation of Flow past Glove-shaped Formers in Latex Dipping to Consider Tip Effect to Free Surface Flow
Authors: Koranuntachai W , Chantrasmi T , Nontakaew U
Published: July 2020

Latex-dipping process in a medical-gloves production line is one of the most critical components that affect the final product quality. In this process, glove-shaped formers are moved through an open-channel latex-dipping tank. Since the gloves have long arms and the latex compound is opaque, it is difficult or impossible to directly observe the flow beneath the free surface. On the other hand, the surface wave and vortex shedding patterns are easily observed or measured on-site. Therefore, it will be beneficial to identify and establish a relationship between the observable surface quantities and the flow underneath. In this work, Computational Fluid Dynamics (CFD) is used to simulate a free-surface flow past a glove-shaped former in comparison to that over a vertical cylinder of the same diameter. The computational results showed that the vortex generation in the near wake is inhibited by the effect of the free surface, and reducing the vortex shedding and vorticity. The shedding from the fingertips has little to no effect on the surface. Most surprisingly, the free surface flow past a glove-shaped former in this setting does not exhibit a transient vortex-shedding pattern unlike the case with a vertical cylinder. This disparity among others makes a vertical cylinder a poor simplified surrogate model for the glove-shaped former.
Minimization of Energy and Water Cost for the Main Building of Suranaree University of Technology Hospital (SUTH)
Authors: Prasetyadi A , Koonsrisuk A
Published: July 2020

Hospitals consume a significant amount of energy and water. Energy and water are intertwined in a way that an improvement of one can worsen the other one. However, as the water price was relatively cheaper in comparison to energy, several studies paid their attention to the minimization of energy usage of the building only. In this research, a study of energy and water for the main building of Suranaree University of Technology Hospital (SUTH) was conducted in order to find the minimum cost of energy and water of the building using proposed a new method namely variables pair. The investigation showed that a single meter of electricity usage as the only energy consumption of the building was applied. Meanwhile, water usage was composed of tap water, flush water, and distilled water. Therefore, a method to determine the cost of energy and water was proposed. A variables pair in a form of (water usage, electricity consumption) was used in the proposed method to determine the cost of energy and water for the main building. Several water-saving options were proposed and examined. It was found that the water and electricity consumptions in the form of variables pair were (82.9 m3/day, 26.3 kWh/day) for a current system, while they were (82.9 m3/day, 21.2 kWh/day) for an option without water regeneration with minimum energy. Meanwhile, they were (82.9 m3/day, 24.4 kWh/day) for a system with water supply tanks allocated at the rooftop and 8th floor of the main building, instead of using only one supply tank installed at the rooftop as in the current system. A system that collects the condensed vapor of the HVAC system and then uses it, had consumptions of (77.3 m3/day, 16.3 kWh/day). Applying the current cost of energy and water at 4.5 Baht/kWh and 10 Baht/m3 respectively it was found that the cost of water could be reduced up to 10.2% with water regeneration. The water cost contributed 7.1% cost reduction, while the energy part was 38.2%. It shows water volume saving is more significant than the energy of water processing saving. The proposed method could separate process and cost parts, therefore it is easy to handle and provides a broader perspective of the saving strategy.
Influence on the Electrical Efficiency of a Hybrid MGT-SOFC-System by μ-fogging in a-Two-Staged Compressor System
Authors: Dückershoff R , Berg H P , Himmelberg A , Lehmann M , Kleissl M
Published: July 2020

Hybrid combinations of solid oxide fuel cell and recuperated micro gas turbines can convert the chemical energy of hydrocarbon-based fuels in electrical energy with high electrical efficiency. With an integrated and improved cycle management, more than 70% of the energy content of the fuel could be converted. Therefore, the systems are highly suitable for the Power-To-Gas conversion. In particular, a pressure charging of the SOFC fuel cell leads to an increase in stack performance. By a downstream turbo set, after residual fuels are intentionally oxidized with an afterburner, additional electrical energy can be gained from the expansion of the hot exhaust gas stream and the overall efficiency can be increased. In order to increase the electrical efficiency of the system, it is proposed, to ensure the required compression of the process air in particular by a-two-staged turbo compressor with an intermediate cooling system. By thus achievable reduction of the dissipation of the compressor and by targeted condensation of finest drops in front of the second compressor stage affected by intermediate cooling, an increase in efficiency of the system is possible. This is achieved by targeted cooling of the process air behind a low pressure compression, so that it is saturated over 100% relative air humidity. As a result, a slightly supersaturated airflow is available for the second compressor stage, which enters the compressor after heat removal via an intermediate cooling having a small number of microdroplets. Therefore, the condensed water evaporates again by the heat of compression in the second stage and the compressed flow ultimately enters the recuperation at a lower temperature than during normal compression. Thus, more heat can be recovered within the recuperation system. Therefore, the electrical energy of the system can be produced having higher efficiency, because the heat dissipation of the overall system decreases. In this article it is presented, how such a process is thermodynamically modelled and how a technical realization can be built after optimization by simulations. Finally, in this study, the process-influencing factors are analyzed to show the highest possible electrical yield of such a system.
Development of a Solar Water Distiller with a Receiver and Condenser
Authors: Tri Le Hieu , Chitsomboon Tawit , Koonsrisuk Atit
Published: July 2020

The solar water distillation distills brackish water, which can mitigate the demand of pure water for the human beings. This study proposes a solar water distiller with a condenser and collector made from a tube bank. The receiver and condenser are connected by the rubber tubes. The brackish water from a tank flows along with condenser. The water temperature is relatively low, so this tube bank acts as a condenser for the water vapor that evaporates from a water basin of the distiller. It is believed that this can increase the condensation rate of the system. After passing through the condenser, the brackish water flows up along the receiver and its temperature is increased. Then the water continuously flows to the basin. According to the experimental results, the water’s temperature in the proposed system is higher than that of the conventional distiller. This leads to the higher productivity of the proposed system (approximately 3.3 L/m2 day). In addition, it was found that the temperature of the condenser of the proposed system was lower than that of the top cover of the conventional system.
Effects of a Microporous Layer on Water Transport Behaviour in PEM Fuel Cell Gas Diffusion Layers
Authors: Jinuntuya F , Kamsanam W
Published: July 2020

This paper studies water transport behaviours in proton exchange membrane (PEM) fuel cell gas diffusion layers (GDLs) under the effects of a microporous layer (MPL) and some GDL structure parameters, namely thickness and pore size. Different paper GDL samples with and without MPL treatment were used in this study. The breakthrough pressure of liquid water and the amount of water retention in the GDL were measured. The results indicate that applying MPL on the GDL substrate has a greater impact on water transport behaviours in the GDL than changing the structure parameters of the GDL substrate. Compared to the GDL without MPL, the results show that applying MPL on the GDL surface considerably increases breakthrough pressure up to 4.3 times, while it greatly decreases water retention in the GDL by up to 13.7 times. For the GDL thickness, the results indicate that thicker GDL of the same structure requires up to 60% higher pressure to break through the GDL, while it can retain up to 4.8 times more water in its structure than thinner versions. Besides, the results indicate that twice-larger mean pore size GDL requires about 1.4 times lower breakthrough pressure, while it retains approximately twice more water in the GDL.
Development of a Transient Dynamic Finite Clement Model for the Drum Testing of a Non-Pneumatic Tire
Authors: Rugsaj R , Suvanjumrat C
Published: July 2020

Non-pneumatic tire (NPT) or airless tire must be designed to meet the required performance such as weight, load carrying capacity and resistance to cyclic loading. The tire dynamic response is also needed to be observed since the tire are constantly subject to cyclic loading while rolling. Drum testing method is preferred over other rolling tire testing method since various factors from the vehicle suspension system and pavement structure are eliminated. This article aimed to develop the finite element (FE) model based on the transient dynamic approach for drum testing of NPT. The finite element model of NPT was created using Ogden hyperelastic material model. The FEM of NPT, which composed of Tread band and Spokes, was model using 3D hexagonal and 2D Quadrilateral elements respectively. The steel belt layers were modelled and embed using rebar elements and tying equation, respectively. The FE model of NPT was then assigned to contact with the rigid drum surface using Coulomb’s friction model. The finite element analysis of drum testing method of NPT as the drum was assigned to be rolling at speed of 11 km/hr. The NPT spoke deformations at each position and the angle was compared to the experiment to prove the validity of the model. The analysis results of spoke deformation were shown to be in a good agreement with the experiment at the average error of 3.51%. The developed FE model of NPT based on transient dynamic approach can be used to evaluate the important dynamic response of NPT during rolling and can be useful in designing the NPT.
Numerical study of temperature dependent thermal conductivity and homogeneous-heterogeneous reactions on Williamson fluid flow
Authors: Hamid Aamir
Published: July 2020

Understanding the flow nature of non-Newtonian fluids need more studies in recent days in terms of their various aspects. Further, heat transfer analysis is an inspiring topic in non-Newtonian flows because of its dominant role in technology. With these incentives, a theoretical investigation is performed to study the time-dependent flow of a non-Newtonian fluid model with focus on heat and mass transfer. In this study, we proposed the mathematical model for the flow of Williamson fluid by incorporating the impact of infinite shear rate of viscosity. With the assistance of rheological expression of Williamson fluid, we construct the governing field equations. For physical relevance we analyzed the impacts of homogeneous-heterogeneous reactions on the flow field. The system of governing partial differential equations is transformed into a set of ordinary differential equations by adopting the non-dimensional variables. This non-dimensional ruling problem together with physical boundary conditions are tackled numerically by utilizing Runge–Kutta Fehlberg scheme via MATLAB software. The physical behavior of friction factor, reduced Nusselt number, dimensionless velocity, temperature and concentration distributions for distinct estimations of leading parameters is examined with the assistance of graphs.
Transitioning hospitalized patients from rivaroxaban or apixaban to a continuous unfractionated heparin infusion: A retrospective review
Authors: Smith Alex R , Dager William E , Gulseth Michael P
Published: July 2020

Purpose

To determine a patient’s clinical course based on the use of an activated partial thromboplastin time (aPTT) or heparin anti-Xa assay when transitioning from rivaroxaban or apixaban to an unfractionated heparin infusion.

Methods

A retrospective chart review was conducted to investigate how unfractionated heparin infusions were managed at a tertiary care hospital in the setting of recent apixaban or rivaroxaban administration. Patients were separated into 2 cohorts based on the chosen heparin infusion monitoring assay: heparin anti-Xa or aPTT. The primary composite outcome was total number of bleeding and thrombotic events; the secondary composite outcome was average incidence of heparin infusion holds and rate changes per patient.

Results

Data were collected from 76 patients (heparin anti-Xa = 69, aPTT = 7). Due to the limited number of patients within the aPTT cohort, this data was excluded from the analysis, and heparin anti-Xa descriptive statistics were reported without statistical comparisons. In the heparin anti-Xa group, a total of 10 bleeds and 1 thrombus were discovered. Additionally, the average number of infusion holds and rate changes was 0.841 and 2.65 times per patient, respectively, for those patients monitored via heparin anti-Xa assay.

Conclusion

In the presence of a recently administered oral anti-Xa anticoagulant, more down-titrations occurred in the initial 6 hours of the heparin infusion when measuring anti-Xa activity, and most up-titrations occurred after 36 hours. Baseline heparin anti-Xa activity may be a useful tool to identify patients with residual plasma concentrations of apixaban and rivaroxaban to help better individualize heparin therapy.
A Double-Blind, Randomized Clinical Trial to Determine Effects of Increasing Doses and Dose-Response Relationship of IncobotulinumtoxinA in the Treatment of Glabellar Rhytids
Authors: Polacco Marc A , Singleton Adam E , Barnes Christian H , Maas Conner , Maas Corey S
Published: July 2020

Background

IncobotulinumtoxinA is an effective neuromodulator for treating glabellar rhytids. The relationship between dose and reduction in rhytid severity is well established. However, the effects of escalating doses on the treatment duration response are less understood.

Objectives

The aim of this study was to assess the effects of increasing doses of incobotulinumtoxinA on the treatment duration for glabellar rhytids.

Methods

A randomized, double-blind, Phase IV study was conducted at a fully accredited, outpatient surgical facility. Subjects (31 female, 7 male) with moderate to severe glabellar rhytids were randomized to 1 of 3 incobotulinumtoxinA dose groups: 20, 60, or 100 U. Effect duration was determined by calculating the time to return to baseline for dynamic glabellar lines during maximal contraction. Follow-up was completed through 1 year, and adverse events were monitored.

Results

The median duration of effect was 120 days (95% confidence interval [CI] [90, 180 days]), 180 days (95% CI [180, 210 days]), and 270 days (95% CI [240, 330 days]) for the 20-, 60-, and 100-U groups, respectively. A Wald chi-square test from the Cox regression on the primary efficacy variable indicated a statistically significant effect of dose group on time to baseline (chi square = 54.63; df = 2; P < 0.001). Hazard ratios were HR = 0.21 (95% CI [0.10; 0.43] for the 60-U vs the 20-U group, and HR = 0.06 (95% CI [0.10; 0.43]) for the 100-U vs the 20-U group, indicating a statistically longer return to baseline for both the 60- and 100-U cohorts.

Conclusions

There is a dose-dependent relationship between incobotulinumtoxinA and duration of effect in the glabella.

Level of Evidence: 2
Mini-Pterional Craniotomy and Extradural Clinoidectomy for Clinoid Meningioma: Optimization of Exposure Using Augmented Reality Template: 2-Dimensional Operative Video
Authors: Jean Walter C
Published: July 2020

A “keyhole” approach to a deep-lying skull base lesion, as such a clinoid meningioma, can be a daunting challenge.
1-3
The minimally invasive exposure must be precisely placed and adequately wide to accomplish the surgical goal. Surgical rehearsal in virtual reality (VR) can not only increase the confidence of the surgeon through practice on patient-specific anatomy,
4
but it can also generate navigation-integrated templates to ensure precise placement and adequate bone openings. In this operative video, we demonstrate the use of an augmented reality (AR) template in a 69-yr-old woman with a growing clinoid meningioma. The 3-dimensional, VR rendering (SNAP VR360, Surgical Theater Inc, Cleveland, Ohio) of her right clinoid meningioma was used in surgical rehearsal for the mini-pterional approach with extradural clinoidectomy. The optimal opening was saved as a VR file and, at surgery, projected into the eye-piece of the navigation-tracked microscope (Synchronized AR v3.8.0, Surgical Theater Inc). In this manner, the surgical opening in the template was visible in AR on the patient's anatomy in real time during surgery. The template enhanced the planning of the incision and soft-tissue exposure, guided the drilling of the sphenoid wing, facilitated the extradural clinoidectomy,
5
and ultimately facilitated the accomplishment of the surgical goal of total resection of the meningioma. With this application of novel technology, the surgeon is no longer using navigation to get her/his bearings. Instead, the surgeon is using AR-enhanced navigation to duplicate a plan that is known to work. This is a fundamental paradigm shift.

 Patient consent was obtained prior to the creation of the video and is available on request.
The Expression of Activin Receptor-Like Kinase 1 (ACVRL1/ALK1) in Hippocampal Arterioles Declines During Progression of Alzheimer’s Disease
Authors: Anderson Kelley E , Bellio Thomas A , Aniskovich Emily , Adams Stephanie L , Blusztajn Jan Krzysztof , Delalle Ivana
Published: July 2020

Cerebral amyloid angiopathy (CAA) in Alzheimer’s disease (AD)—deposition of beta amyloid (Aβ) within the walls of cerebral blood vessels—typically accompanies Aβ buildup in brain parenchyma and causes abnormalities in vessel structure and function. We recently demonstrated that the immunoreactivity of activin receptor-like kinase 1 (ALK1), the type I receptor for circulating BMP9/BMP10 (bone morphogenetic protein) signaling proteins, is reduced in advanced, but not early stages of AD in CA3 pyramidal neurons. Here we characterize vascular expression of ALK1 in the context of progressive AD pathology accompanied by amyloid angiopathy in postmortem hippocampi using immunohistochemical methods. Hippocampal arteriolar wall ALK1 signal intensity was 35% lower in AD patients (Braak and Braak Stages IV and V [BBIV-V]; clinical dementia rating [CDR1-2]) as compared with subjects with early AD pathologic changes but either cognitively intact or with minimal cognitive impairment (BBIII; CDR0-0.5). The intensity of Aβ signal in arteriolar walls was similar in all analyzed cases. These data suggest that, as demonstrated previously for specific neuronal populations, ALK1 expression in blood vessels is also vulnerable to the AD pathophysiologic process, perhaps related to CAA. However, cortical arterioles may remain responsive to the ALK1 ligands, such as BMP9 and BMP10 in early and moderate AD.
Control of T-DNA Transfer from Agrobacterium tumefaciens to Plants Based on an Inducible Bacterial Toxin-Antitoxin System
Authors: Denkovskienė Erna , Paškevičius Šarūnas , Stankevičiūtė Justina , Gleba Yuri , Ražanskienė Aušra
Published: July 2020

High-value pharmaceutical products are already successfully produced in contained facilities using Agrobacterium-mediated transient transformation of plants. However, transfection methods suitable for open field applications are still desirable as a cheaper alternative. Biosafety concerns related to the use of recombinant agrobacteria in an industrial transfection process include possible transformation or transfection of unintended hosts or spread of the genetically modified agrobacteria in the environment. In this paper, we explored a novel biocontrol approach resulting in greater biosafety of the transient expression process in plants. Our proposed solution involves inducible expression of Agrobacterium tumefaciens toxin PemK and antitoxin PemI that provides for strictly regulated T-DNA transfer from agrobacteria to plants. We also identified several other toxins from putative Agrobacterium toxin-antitoxin modules and demonstrate their potential usefulness in the control of Agrobacterium tumefaciens as a DNA vector.
Crop Establishment SIMulator: A Qualitative Aggregative Model to Predict the Role of Phytobiomes on Field Crop Establishment
Authors: Lamichhane Jay Ram , You Ming Pei , Barbetti Martin J. , Aubertot Jean-Noël
Published: July 2020

The definition of phytobiomes can be transposed to any agroecosystem and applies to any phase of crop cycles. Here, we study the crop establishment phase using a generic modeling framework to assess the potential role of phytobiomes on field crop establishment. We first developed a generic model called Crop Establishment SIMulator (CESIM) that takes into account cropping practices, seed and seedling characteristics, seedbed components (physical chemical and biological), and weather, as well as their interactions. All these variables were integrated in a qualitative aggregative hierarchical network to predict the quality of field crop establishment. CESIM has 38 basic (input variables) and 20 aggregated (19 state variables and 1 output variable) attributes for a total of 58 attributes. The prediction quality of the model was evaluated for a dataset of 231 field observations across four states of Australia and experimental results obtained in the last 40 years. Accuracy of predictions of the final attribute (i.e., crop establishment) was 91% and explained 29% of variability of the dataset, as described by the quadratic weighted Cohen’s κ. CESIM represents a unique and original generic model capable of taking into account a large number of variables and their interactions to predict the quality of field crop establishment. This model is flexible, transparent, and user friendly and, therefore, is suitable both for academic and nonacademic users. CESIM can be used across a wide range of situations to perform not only the ex-ante assessment of potential establishment quality of a given crop but also ex-post assessment.
Comparing children and adults with chronic nonbacterial osteomyelitis
Authors: Lenert Aleksander , Ferguson Polly J.
Published: July 2020

Purpose of review

To describe the main clinical differences of children and adults with chronic nonbacterial osteomyelitis (CNO).

Recent findings

CNO is a severe systemic autoinflammatory syndrome characterized by multiple bone lesions because of inflammatory osteitis. Delay to diagnosis of CNO can lead to functional impairment, fractures, and chronic pain. Key clinical aspects and disease patterns differ in children and adults, including onset and time to diagnosis, symptom localization, associated comorbidities (i.e. skin, joints), bone lesion distribution pattern, and treatment approach. Novel biomarkers, such as urine N-terminal telopeptide in children and serum IgG4 in adults, are being studied for possible future use in improving diagnosis and guiding treatment. Despite recent advances in our understanding of CNO, many children and adults have a high disease burden and poor long-term outcomes. Recent findings suggest that adults with CNO tend to have a more chronic disease course and are less likely to achieve remission in follow-up.

The clinical presentation of CNO differs in children and adults, highlighting the importance of these key features for the accurate diagnosis and early treatment in CNO.
Role of Anterior Segment OCT for Descemet Membrane Stripping During Descemet Membrane Endothelial Keratoplasty in Eyes With Congenital Hereditary Endothelial Dystrophy
Authors: Fogla Rajesh
Published: July 2020

Purpose:

To report the utility of preoperative anterior segment optical coherence tomography (ASOCT) in decision-making for stripping of the Descemet membrane (DM) during Descemet membrane endothelial keratoplasty (DMEK) in eyes with congenital hereditary endothelial dystrophy (CHED).

Methods:

ASOCT was performed in eyes with CHED undergoing DMEK. Host DM was retained if the DM appearance was normal on ASOCT. Outcomes of DMEK with or without DM stripping (non DM stripping [DMEK]) were analyzed and compared regarding graft adhesion, graft clarity, visual acuity, and complications.

Results:

Twelve eyes of 8 patients were included in the series. Of these, 6 eyes (mean age, 6 ± 2.6 years, range 3–8 years) underwent nDMEK and 6 eyes (mean age, 23.6 ± 10.2 years, range 13–39 years) underwent standard DMEK. There were no intraoperative complications in either group. During the early postoperative period, one eye in the nDMEK group had donor detachment that was successfully managed by repeat air injection. The mean preoperative and postoperative corrected visual acuities were 1.15 and 0.37 logarithm of the minimum angle of resolution (LogMAR) in the nDMEK group, and 0.95 and 0.25 LogMAR in the DMEK group (P 0.39 and 0.06). Average endothelial cell counts were 1826 ± 318 cell/mm2 in the nDMEK group (32.3% loss), and 1708 ± 271 cells/mm2 in the DMEK group (33.6% loss) at the last follow-up.

Conclusions:

Preoperative anterior segment OCT is useful in decision-making regarding stripping of host DM during DMEK in eyes with CHED. The outcomes of nDMEK were similar to DMEK in this small series.
Novel Microforceps Technique Developed for Endothelial Surgical Procedures
Authors: Berry J. Christian , Moore Lee E. , Riaz Kamran M.
Published: July 2020

Purpose:

To develop a more efficient and less traumatic method of Descemet membrane removal in endothelial surgery.

Methods:

A novel, vertically oriented, reverse-grasping microforceps (named the Rabiyah Descemet Membrane Removal Microforceps) were created to facilitate grasping and extraction of a host Descemet membrane.

Results:

This new instrument has been used successfully and safely in more than 85 endothelial keratoplasty cases among 4 surgeons.

Conclusions:

The Rabiyah Descemet Membrane Removal Microforceps provides surgeons with a safe and an efficient option to remove Descemet membrane in endothelial surgical procedures.
Evaluation of Visual Acuity Outcomes and Corneal Alterations of New Generation Hybrid Contact Lenses in Patients With Advanced Keratoconus
Authors: Dikmetas Ozlem , Kocabeyoglu Sibel , Mocan Mehmet Cem
Published: July 2020

Purpose:

To evaluate the visual and corneal outcomes of new generation hybrid contact lenses (HCL) in patients with advanced keratoconus.

Methods:

This was a retrospective study undertaken at a single academic center. The study cohort consisted of subjects with advanced keratoconus who had elected not to undergo keratoplasty and were fitted with HCLs. Patients were fitted either with EyeBrid (LCS, Cane, France) or Airflex (SwissLens, Prilly, Switzerland) HCLs. Primary outcome measures included contact lens (CL) drop-out rate, best corrected visual acuity, and corneal endothelial cell density (ECD) measurements at the end of a 6-month HCL wear. ECD was measured using in vivo confocal microscopy (ConfoScan4; Nidek, Tokyo, Japan). One eye per patient was included for statistical purposes. Paired t tests and Wilcoxon signed-rank tests were used for comparative analyses.

Results:

Thirty-two keratoconic eyes of 32 patients (14M/18F) with a mean age of 25.9 ± 11.5 years were included in the study. All patients were able to continue CL wear for a duration of 6 months. There was a significant improvement in the mean best corrected visual acuity from 0.5 ± 0.2 logarithm of minimal angle of resolution to 0.1 ± 0.1 logarithm of minimal angle of resolution after daily CL wear with HCL at the 6-month follow-up visit (P < 0.001). No vision-threatening CL-related corneal adverse effects were observed. There was no significant reduction in the ECD noted at the 6-month visit [2625.8 ± 300.3 cells/mm2 (baseline) vs. 2566.4 ± 309.8 cells/mm2 (6-month); P = 0.623].

Conclusions:

Hybrid contact lenses can provide improved visual function without inducing any short-term clinical or microscopic adverse effects on corneal endothelial cells in patients with advanced keratoconus.
Optimizing Visualization of Descemet Membrane Endothelial Keratoplasty Tissue: Assessing the Impact of Trypan Blue Exposure on Stain Duration and Corneal Endothelial Cell Function
Authors: Ling Jennifer J. , Kyrillos Ralph , Burckart Kimberlee A. , Aldrich Benjamin T. , Skeie Jessica M. , Schmidt Gregory A. , Conwell Chris , Ramirez Tiffany , Reed Cynthia R. , Zimmerman M. Bridget , Greiner Mark A. , Li Jennifer Y.
Published: July 2020

Purpose:

To assess how trypan blue staining affects Descemet membrane endothelial keratoplasty (DMEK) graft visibility and corneal endothelial cell (CEC) mitochondrial respiration.

Methods:

DMEK grafts (n = 20) were stained with trypan blue 0.06% for 1, 3, 5, or 10 minutes. Each graft was injected into an artificial anterior chamber. Surgery was simulated with tapping and sweeping motions on the corneal surface and injections of balanced salt solution (BSS). Graft visibility was assessed at 5, 10, 20, and 30 minutes. Effects of trypan blue on mitochondrial respiration were assessed using primary CECs cultured from donor corneas (n = 43). Treatment wells exposed to trypan blue 0.06% (1, 5, or 30 minutes) and donor-matched control wells to methylene blue 1% (1 minute) or BSS (1, 5, or 30 minutes) were assayed for key respiration parameters.

Results:

After 5 minutes of surgical manipulation, grafts stained for 5 minutes were significantly more visible than grafts stained for 1 or 3 minutes; there was no added benefit of staining for 10 minutes. After 10 minutes of surgical manipulation, grafts stained for 3 minutes were more visible than grafts stained for 1 minute, without additional benefits of staining ≥5 minutes. No visibility differences were observed after ≥20 minutes of surgical manipulation. CEC mitochondrial respiration did not change significantly following trypan blue exposure for all intervals tested compared to BSS.

Conclusions:

Staining DMEK grafts with trypan blue for 3 to 5 minutes optimizes visibility during surgical manipulation without mitochondrial impairment. Corneal surgeons learning DMEK will benefit from optimizing this critical step.
Measuring Student Interprofessional Skills in the Roles/Responsibilities Competency
Authors: Chappell Rachel , Goumas Amanda , Hollie Shay , Levitzky Elizabeth G. , Gunaldo Tina Patel
Published: July 2020

Purpose

To assess students' perceptions and knowledge of interprofessional collaborative practice related to the Interprofessional Education Collaborative (IPEC) Roles/Responsibilities (RRs) competency after engagement in interprofessional education experiences.

Methods

Thirty physician assistant students were surveyed 3 times during the clinical year to assess the level of collaborative engagement with 5 professions. The level of engagement was assessed utilizing a 5-point Likert scale, and an open-ended question measured student knowledge of other professionals' roles.

Results

Student responses indicated that the level of engagement was greatest during the first clinical semester overall for all 3 levels of engagement. An increase in the level of engagement was noted for 2 professions over the one-year study period. Students also provided examples of opportunities where they relied on the expertise of another profession during the clinical rotation year.

Conclusion

Study results confirm student acquisition of 2 IPEC RR subcompetencies during clinical rotations. However, there remains a gap in correlating interprofessional education with interprofessional collaborative practice.
Role of endoscopic ultrasonography guided fiducial marker placement in gastrointestinal cancer
Authors: Kerdsirichairat Tossapol , Shin Eun Ji
Published: July 2020

Purpose of review

Dose escalation radiation therapy such as those delivered by stereotactic body radiation therapy (SBRT) has shown to improve local disease control in multiple types of malignancies. This requires fiducial placement to improve accuracy of treatment and avoid adverse events to adjacent radiosensitive organs during respiration phases. The purpose of this review is to provide updates of recent high-quality articles related to endoscopic ultrasonography (EUS)-guided fiducial placement for gastrointestinal malignancies, particularly in pancreatic cancer, which is expected to be the second leading cause of cancer-related deaths in the USA within this decade.

Recent findings

A recent systematic review and meta-analysis has shown that EUS-guided fiducial placement for gastrointestinal malignancies has excellent technical success and safety profile. Comparative studies of most commercially available fiducial types via a 22-gauge needle system showed that a 0.035 mm diameter and 10 mm long gold fiducial with coiled configuration, hollow core and external helical design might be favoured due to its most balanced performance of visibility, artifact and migration.

A fine balance of performance characteristics of fiducials should be discussed with radiation oncologists to select a suitable and preferred type of fiducials. The comparative studies of other newly developed platinum fiducials and liquid fiducial are pending.
Insights into ADAMTS13 structure: impact on thrombotic thrombocytopenic purpura diagnosis and management
Authors: Roose Elien , Veyradier Agnès , Vanhoorelbeke Karen
Published: July 2020

Purpose of review

Fundamental knowledge on the role of a disintegrin and metalloprotease with thrombospondin type one repeats, member 13 (ADAMTS13) has been crucial to better understand the pathophysiology of the rare and life-threatening disease thrombotic thrombocytopenic purpura (TTP).

Recent findings

ADAMTS13 works through a molecular zipper mechanism to proteolyze its substrate von Willebrand factor (VWF). Recent insights into the structure and function of ADAMTS13 led to the identification of an allosteric activation mechanism. Therefore, ADAMTS13 is roughly folded in two in which the N-terminal spacer (S) domain and C-terminal T7-CUB2 domains interact to adopt a closed conformation. Upon substrate binding, ADAMTS13 adopts an open conformation in which the S-T7-CUB2 interaction is abrogated to further position VWF towards the catalytic cleft, inducing activation of the latent metalloprotease domain and resulting in cleavage of VWF. Unravelling the structure function relationship of ADAMTS13 helped identifying open ADAMTS13 as a novel and unique biomarker for immune-mediated TTP (iTTP). This novel biomarker has potential in the diagnosis, treatment and follow-up of iTTP.

In this review, the most recent findings on the structure and working mechanism of ADAMTS13 are addressed. In addition, how those findings led to the identification of a novel biomarker, and how this novel biomarker could have an impact on the diagnosis, management and follow-up of iTTP patients are discussed.
PET imaging in testicular tumours
Authors: Calabrò Diletta , Telo Silvi , Ambrosini Valentina
Published: July 2020

Purpose of review

Testicular cancer is rare, but its incidence is expected to rise. [18F] fluorodeoxyglucose ([18F]FDG) PET/computed tomography (CT) added role in testicular cancer management has been defined in a set of specific clinical settings. The current review focuses on recent advances in the employment of PET/CT in testicular cancer patients.

Recent findings

[18F]FDG PET/CT is not recommended for initial staging or for suspected testicular tumours. PET/CT role in testicular cancer management is mainly for the assessment of seminoma residual masses after therapy (>3 cm). Although [18F]FDG PET/CT has a very high negative predictive value, its positive predictive value varies across studies: appropriate PET/CT scheduling after therapy and a careful history are mandatory for accurate interpretation. Interim PET/CT could prove valuable to spare subsequent chemotherapy cycles in patients already in remission, reducing related toxicity. The role of [18F]FDG in nonseminoma tumours is hampered by the low sensitivity in teratoma.

[18F]FDG PET/CT is currently used for the assessment of seminoma residual masses (>3 cm) after therapy. A negative PET could also spare unnecessary further chemotherapy cycles in responding patients, reducing toxicity. Although rare, testicular secondary lesions can be detected with non[18F]FDG tracers when PET/CT is performed for other primary tumours.