bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparative Numerical Investigation on Machining of Laminated and 3D Printed CFRP Composites
Authors: Hassan Mahmudul , Alimuzzaman Sk Md , Ma Jianfeng , Jahan Muhammad
Published: February 2023

One of the shortcomings of 3D printed or laminated carbon fiber reinforced polymer (CFRP) composites is that their dimensional precision and surface finish fall short of the normal tolerance requirements for most industrial applications. Machining is often necessary as a post-processing step to get the CFRP parts in appropriate form. This research uses numerical modeling and simulation with ABAQUS/Explicit, a commercially available sophisticated finite element analysis (FEA) software program, to compare the machining behavior and post-processing capabilities of laminated and 3D printed CFRP composites. The effects of machining parameters, such as, feed, cutting speed and depth of cut (DOC), and 3D printing parameters like percentage of overlap between neighboring passes and layer heights, have been investigated. Cutting forces, strain, chip and burr development, and the consequent surface topology have all been used to assess the post-processing capability or machining behavior of CFRPs. A 3D model was built using appropriate damage initiation and propagations factors such as ductile and shear damage, as well as the Johnson-Cook criteria for plasticity. C3D8R elements, which are 8-node brick elements, were used to mesh each layer of the laminated workpiece model. For 3D printed models, linear tetrahedral elements, also known as C3D4T, were employed to capture changes in elemental level. The cutting and thrust forces generated increased as the DOC, cutting speed and feed rate increased. Chip formation was primarily controlled by stiffness and flute shape of the cutting tool, and 3D print direction. It was seen that the surface quality is better for laminated CFRPs. The highest cutting force obtained are found to have an essentially proportional correlation with feed, layer height, and spindle speed. Finally, the findings are persuasive, and they may be utilized to direct actual machining operations and achieve the required results.
Experimental Study on Stress Measurement Based on Zero-Group-Velocity (ZGV) Lamb Waves
Authors: Pancong He , Maodan Yuan , Xuanrong Ji , Weiming Xuan
Published: February 2023

The stress state of engineering structures is the key information for the reliability evaluation. However, conventional ultrasonic method is not suitable for local stress measurement. The dispersion characteristics of Lamb wave acoustoelasticity show that higher-order Lamb waves near cut-off frequency possess higher sensitivity to stress. Considering that the proximity of zero-group-velocity (ZGV) mode and the cut-off frequency and its sensitivity to local material property, a local stress measurement method based on ZGV mode is proposed for thin plates. An oblique incident ultrasonic system was built for experimental validation. The wedges were tailored made based on the Snell’s law to efficiently excite and receive the signal of S1-ZGV mode. The frequency of S1-ZGV was obtained by spectra analysis after filtering out the direct wave part. Tensile experiments were carried out on a uniform 6061 aluminum plate with 3mm to obtain the calibration curve between S1-ZGV frequency and stress level. Then a step-wise plate was designed to generate different stress at two positions on a tensile testing machine. The stresses were then evaluated by the calibrated frequency-stress coefficient. The measured stresses agreed well with the calculated stress, proving that S1-ZGV method is effective for local stress measurement in thin plates.
Production of Date Palm Nanoparticle Reinforced Composites and Characterization of Their Mechanical Properties
Authors: Al-Safy Mahmoud , Al Hinai Nasr , Alzebdeh Khalid
Published: February 2023

The extraction of Nano-sized fillers from bio sources has been a key focus of the material industry to secure green composites for a wide range of applications. Consequently, chemical fragmentation and downsizing of waste lignocellulosic fibers into small size particles is a viable economic and environmental option. The objective of this work is to explore the potential use of Nano natural fillers as a reinforcement element in thermoplastic polymers. In specific, the Nano-sized lignocellulosic filler is extracted from date palm microfibers using the mechanical ball milling technique. The ball milling is performed at a high speed of 12 cycles per minute for four different time durations. The achieved nanoparticle size ranged from 80 to 122 nm, reduced to a range of 70 to 51 nm and then reached 27 to 39 nm after 3, 4 and 5 hours of powdering, respectively, with no significant change in size after 6 hours of milling. After that, the morphological properties of the produced fillers are characterized using various techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Finally, the mechanical performance of the reinforced recycled polypropylene (rPP) using 10% (wt.) date palm nanofillers is investigated using tensile and flexural tests, as well as the physical properties including water absorption and density tests. Successful implementation of nanofillers in bio-composites offers an economical and sustainable route to attain high-performance material in the future.
Flexible Low-Level Control Software Framework for Achieving Critical Real-Time Deadlines
Authors: Tremaroli Nicholas J. , Stelmack Maxwell A. , Herron Connor W. , Kalita Bhaben , Leonessa Alexander
Published: February 2023

In this work, a low-level software framework is proposed to simplify software development for Hardware Abstract Layered (HAL) control systems, identify networking methods for accurate real-time communication between devices, and verify task completion. The framework is implemented on a distributed microcontroller system composed of Texas Instruments TM4C123GXL Tivas for a multi-joint robot. The robot’s high-level controller executes dynamic motion control algorithms, with low-level controllers responsible for each individual joint. All microcontroller software is unified into one program and uses initialization files from the high-level controller to configure each individual Tiva depending on its location on the robot. The EtherCAT communication protocol is utilized to avoid unnecessary overhead from traditional networking protocols. A real-time operating system, TI-RTOS, enforces crucial deadlines and provides powerful diagnostic tools for the designer to optimize task completion. Overall, our proposed framework overcomes the major challenges of writing low-level control software so that development is less time-consuming, simpler to manage, and easier to validate. Further, this work can be used for many kinds of robotic systems and applications that use microcontrollers within a multi-layered control architecture.
A Comprehensive Assessment of Gearbox Tooth Faults Based on Dynamic Modelling and Machine Learning
Authors: Kumar Vikash , Mukherjee Subrata , Kumar Sanjeev , Sarangi Somnath
Published: February 2023

This paper presents a dynamic model-based gearbox fault diagnosis using machine learning. A single-stage spur gear using an eight-degrees-of-freedom (DOF) dynamic model is developed and investigated with four gear tooth conditions, i.e., healthy tooth, 20 % tooth crack, 40 % tooth crack, and 60 % tooth crack. In the developed model, an analytically improved time-varying mesh stiffness (IAM-TVMS) model, which considers the effects of structural coupling of loaded tooth, nonlinear Hertzian contact stiffness, precise transition curve, and misalignment between base and root circle, and an improved tooth crack model, are incorporated to get a reliable system dynamic response. To make the simulated response more realistic, different levels of negative white Gaussian noise (−2dB to −10dB SNR) are added to the simulated signal. The simulated noisy signals are then segmented, and a total of 12 statistical indicators are calculated on each segmented signal to develop the feature matrix. Four different machine learning algorithms are used to classify the faults from the extracted feature matrix, and their performances are compared and discussed. The results show that the KNN classifier outperformed them all, with a classification accuracy of 90.5 %. The finding shows that the proposed method works well in the presence of intense noise and may help in identifying the faults in the system in quick time without expending too much on experimental test setup.
Vision-Based Horizontal Structure Tracking and Inspection via Unmanned Aerial Vehicle
Authors: Kumar Amit , Shukla Amit , Gupta Ayush , Shivratri Ashok Kumar
Published: February 2023

The involvement of unmanned aerial vehicles in the civilian domains has made the task quite speedy, cost-effective, and risk-free. This paper provides a general approach to how horizontal civil structures such as bridges can be tracked and monitored using unmanned aerial vehicles. The work is divided into two sections. The first one is the identification of horizontal structures, followed by structure tracking. Images taken from the mounted camera on the UAV are first processed to extract features with the help of computer vision. Then, from the features, the important parameters are taken out to design a controller that handles the tracking process. Also, during this tracking process, the whole structure area is scanned. This work contains simulation results of vision-based structure tracking done on a gazebo simulator.
Effect of Flapper Valve on the Performance of a Hydraulic Ram Pump
Authors: Sharma Ashokkumar M. , Banerjee Dipak K. , Pidugu Srikanth B.
Published: February 2023

Water supply is one of the imminent challenges in the coming age for mankind. The hydraulic ram pump is an eco-friendly and very cost-effective technology that can feasibly transport water from nearby water resources (such as lakes, streams, and rivers) to remote places for daily water needs. The goal of the present work was to investigate the effect of flapper valve size on pump performance. It was hypothesized that the decrease in the flapper valve size would impose more flow resistance at the waste-valve outlet diverting more water flow towards the ram pump inlet, which will increase the amount of water to the delivery tank. Based on the previous study, four flapper valve sizes (1-inch, 3/4-inch, 1/2-inch, and 1/4-inch) were selected for this study. Experiments with riser tubes were carried out using the selected flapper valve sizes. Results confirmed that the flapper valve size has a considerable influence on performance of the hydraulic ram pump. The 3/4-inch flapper valve displayed the maximum pump’s volumetric (21.7%) and energy (38.9%) efficiencies, followed by 1-inch, 1/4-inch, and 1/2-inch sized flapper valves. The flow capacity of the studied hydraulic ram pump system for 3/4-inch valve was found to be 1121 gal/day.
Development of a Soft Robotic Gripper for Carpet Handling
Authors: Abbas Ayman , Sahbel Anwar
Published: February 2023

The use of soft robotic grippers is an alternative to conventional rigid body grippers in industrial applications specifically in the handling of carpets. This paper presents, a novel design of a 3D soft robotic gripper based on a simulation model and experimental prototype that can be used for carpet handling applications. In addition, the fabrication method of the pneumatic soft robotic gripper is introduced. The pneu-net actuator geometrical parameters are optimized such as the thickness of the chamber walls and the internal structure of the chambers resulting in significantly improved pressure handling capabilities. The simple pneu-net and the modified actuator are tested at two different pressure 55 and 110 kPa, to check the range of motion. A single actuator is calculated to lift a maximum of five kilograms, with several actuators included in the gripper the weight carrying capabilities reached ten kilograms. The geometry was optimized to maximize weight carrying capabilities by increasing the amount of pressure the actuator can withstand. A finite element analysis using ABAQUS software is carried out to evaluate the stresses acting upon the soft gripper.
A Method to Account for the Effects of Electro-Osmotic Drag and Back Diffusion in PEM Fuel Cells
Authors: Ingarra Nicholas , Kobus Krzysztof (Chris) , Maisonneuve Jonathan
Published: February 2023

The objective of this research is to quantify the separate effects of electro-osmotic drag (EOD) and back diffusion (BD) on the net water flow across a proton exchange membrane (PEM) where these effects occur simultaneously. The solution here is to detail a method to decompose the net water flow into component drivers without making assumptions regarding the various coefficients, and instead relying on data mining to isolate the EOD and BD contributions. The net water flow across the membrane is a function of current density and water concentration differences, represented as a surface for which slopes can be determined in the direction of constant current to isolate BD, and constant concentration difference to determine EOD. This method also can be used to determine the hydration state of the membrane as well as determining which EOD and BD coefficient empirical models are valid under certain conditions. With a clearer understanding of net water flow, EOD and BD, the water balance of the fuel cell can be improved which will lead to improved fuel cell operation.
FEA-Based Prediction and Experimental Validation of Drilling Tool Lateral Motion Dynamics
Authors: Song Fei , Li Ke , Xu Liangyu
Published: February 2023

Logging-while-drilling (LWD) tools are placed in the bottomhole assembly (BHA) at the lowest part of the drillstring, which are used for measuring formation properties during the excavation of the hole, or shortly thereafter. These formation properties can include spectral gamma ray, neutron, porosity, resistivity, and many others. With the tools being pushed to complete wells faster and cheaper, drilling conditions are becoming increasingly harsh. A variety of downhole vibration modes that hinder efficient drilling could occur and create wasted energy that is unusable to cut formation. Among them, BHA whirl is one of the undesired motions which can be faced during drilling operations, where the BHA follows an eccentric rotation about a point along the wellbore other than the geometric center. BHA whirl can be one of the most destructive types of drilling dynamics. For example, the lateral motion induced shock and vibration can be propagated from the outside collar to the inside chassis of the tool and damage the expensive electronics or other measurement devices. Therefore, having a reasonably accurate numerical model that can be used to understand and predict the lateral motion of a tool is highly demanded to mitigate the risks associated with the effect of whirl on measurement quality and health of the drilling tools.

This study focuses on simulating the most seen backward whirl scenario where the center of the motion rotates in the opposite direction of the drill string. A high-fidelity 3D finite element analysis (FEA) model that can capture the contact interaction between the outside collar and internal chassis of the tool and between the tool and wellbore is developed to predict the lateral motion of the drilling tool in the presence of backward whirl. A roll test system (i.e., a tubular assembly rolls along the inner wall of an impact ring while spinning with a drive motor) instrumented with accelerometers, strain gauges and high-speed cameras is also developed to mimic such dynamics that the tool could experience while drilling in a controlled lab environment. The measurements collected from the accelerometer and strain gauge are analyzed and the videos recorded with the high speed camera is processed with computer vision to experimentally determine the motion trajectory and characteristics. Excellent agreement is observed between experimental motion data and the predictions from the developed FEA model, which validates the FEA model. The validated numerical model can be very useful for fit-for-basin virtual qualification of new drilling tools and for post-run root cause analysis of drilling tool failures.
Additive Manufacturing Process-Induced Wing Skin Deformation and Effects on Aerodynamic Performance
Authors: Valenti Justin D. , Barolai Joseph , Cole Julia A. , Yukish Michael A.
Published: February 2023

The objective of this study is to characterize the trade space for the structural design of small uncrewed aerial vehicle wings fabricated using Material Extrusion Additive Manufacturing, specifically the trade-off between maintaining the wing external shape while minimizing its internal structure. Beam bending analysis shows that the structural requirements associated with flight loads are easily met with a single perimeter extrusion monocoque construction, however this approach leads to large, unsupported, thin-walled structures that can deform during the build process, creating a potential need for additional structure to maintain wing shape. To characterize the relationship between structure/weight and wing deformation, wing sections were fabricated with varying internal structures for two airfoil shapes. Weight and 3-D laser measurements were taken of the printed parts to capture the final as-built geometry. The as-built geometries were then compared to the as-designed geometries to quantify the deformation, and a coupled viscous-inviscid flow solver was used to determine the aerodynamic effects. The results indicate that while significant aerodynamic performance penalties exist for the monocoque construction, a small amount of well-placed internal structure provides sufficient improvement at minimal weight penalty. Results also showed that less internal structure is required to minimize deformation for an airfoil with larger initial curvature.
Numerical Simulation for Analyzing Interfacial Velocity and Interfacial Forces of a Bubble Motion in Taper Micro Gap
Authors: Pal Divyprakash , Shukla Maharshi , Perez-Raya Isaac , Kandlikar Satish
Published: February 2023

Heat transfer due to the convective boiling mechanism in the microchannel plays an important role in heat transfer during boiling. Therefore, it is relevant to find ways to manipulate the vapor bubbles such that convection heat transfer is enhanced. This numerical study investigates the effects of different geometrical parameters on bubble movement through a micro tapered gap. The objective is to identify an optimal configuration such that the bubble moves at the fastest possible speed when it travels through the micro gap. To conduct this research a model is created using ANSYS-Fluent which uses the Volume of Fluid (VOF) interface tracking method. The multiphase VOF model tracks the air-water interface. A bubble is generated inside the microchannel in which fluid is flowing. The overall domain of the model consists of the surface at the bottom, having an orifice through which the air bubble is generated. Three different cases of an angled tapered surface are created 5°, 10°, and 15°. The airflow rate is kept constant throughout each simulation. Simulation results show the impact of the tapered angle on the bubble’s flow movement and flow direction. Liquid and air velocity contours can be used to analyze the flow. The impact of the taper angles on the movement and flow direction of the air bubble is discussed. It is observed that the performed simulations help to better understand the experimental observation of bubble motion; the simulations give clear evidence of the fluid dynamic behavior along the tapered microchannel.
Photoresponse of O2 plasma treated WS2 monolayers synthesized by chemical vapor deposition
Authors: do Nascimento Barbosa André , Stand Figueroa Neileth Johanna , Diaz Mendoza Cesar Augusto , Freire Fernando Lázaro
Published: February 2023

WS2 monolayers synthesized by chemical vapor deposition underwent low-power O2 plasma treatment, and the effect of this treatment was studied in this work. The results show that the WS2 photoresponse is quenched due to the treatment and subsequently vanishes for more extended periods of plasma exposure. Raman spectra of the treated WS2 monolayers show that the position of the LA(M) mode is blueshifted and has a larger FWHM when compared with pristine samples. Since the LA(M) phonon can be used as a figure of merit to infer indirectly a density of defects in the lattice, these results show an increase in defects upon treatment times. At the same time, the main E2g and A1g peak positions remain nearly unchanged for short plasma exposures, indicating that there is an intrinsic defect-related process rather than a strain-related change. X-ray photoelectron spectroscopy results reveal the presence of O impurities incorporated into lattice passivating sulfur vacancies, while atomic force microscopy confirms that the sample creates cracks at the micrometer scale. Our results indicate that the pure oxygen plasma treatment significantly reduces the photoresponse of WS2 monolayers by increasing the density of defects.
Weather related detection probability of Lacerta agilis LINNAEUS, 1758 within the core range in Western Germany
Authors: Clement Vic Fernand , Edanackaparampil Julia , Schmitz Lisa Maria , Schluckebier Rieke , Rödder Dennis
Published: February 2023

Weather conditions are important factors determining the activity, and consequently detection probability, of animals. Especially in ectotherms from temperate habitats, activity can vary strongly depending on weather. The sand lizard Lacerta agilis is a wide-ranging lizard that is often subject to environmental impact assessments due to its proximity to humans and prevalence as a candidate for compensatory measures according to the Flora and Fauna Habitat Directive of the European Union. Lacerta agilis has been studied extensively at certain edges of its distribution, but studies focusing on the core range have been rare. We use Bayesian models in order to identify the best explaining weather variables out of a large variety of available variables for a population of Lacerta agilis in western Germany. We furthermore depict their interactions with an easy-to-understand regression tree model. Sand lizards have shown to be more active during dry conditions with low windspeeds. They further are best found after sunny weather with temperatures around 20°C. Rainfall in the previous 24 hours also increases the detection probability. An unpruned regression tree reaffirms the results while giving concrete variable values and exploring how the values influence each other. Overall the method delivers a decision tree based on easy to obtain weather variables that allows for post- survey analysis and for determination of the best survey conditions.
Factors That Influence Physical Activity in Individuals With Down Syndrome: Perspectives of Guardians and Health Professionals
Authors: Schultz Emma E. , Sergi Katerina , Twietmeyer Gregg , Oreskovic Nicolas M. , Agiovlasitis Stamatis
Published: February 2023

Identifying factors that influence physical activity (PA) among individuals with Down syndrome is essential for PA promotion. Insight can be gained from guardians and health professionals. The purpose of this study was to explore the perspectives of guardians and health professionals on facilitators and barriers of PA in individuals with Down syndrome. Interviews were conducted with 11 guardians (five mothers, four fathers, and two legal guardians) and 11 professionals (four PA specialists, three physical therapists, and four occupational therapists). Grounded theory was applied. Barriers and facilitators fit the levels of the ecological model of health behavior: (a) intrapersonal (perceived rewards), (b) interpersonal (interaction), (c) community (availability of programs), (d) organizational (school systems), and (e) policy (education). Guardians and professionals agreed on the importance of enjoyment, interaction, and programs to promote PA. Differences between groups were identified at the organizational and policy levels. PA in persons with Down syndrome is influenced by interactions between individual and environmental factors.
Association Between Variations in Training Load, Sleep, and the Well-Being of Professional Hockey Players
Authors: Apinis-Deshaies Amélie , Trempe Maxime , Tremblay Jonathan
Published: February 2023

Purpose: To evaluate whether sleep quantity and quality of professional hockey players is affected by external training load (TL), their perception of well-being, and contextual factors associated with match participation. Methods: Fifty male athletes were monitored daily during the 28 weeks of the regular season using well-being and sleep surveys. On-ice external TL was monitored using portable inertial measurement units during practices and matches. Linear mixed-effects models were applied to evaluate whether well-being perception (ie, pain, nutrition, stress, and rest) and external TL may affect sleep quality and quantity. Results: High levels of well-being positively affected sleep duration and quality (P < .001), whereas high-intensity TL had a detrimental impact on sleep duration (P = .007). Moreover, away and evening matches had a detrimental effect on sleep quantity and quality (P < .001). Finally, a high match on-ice load per minute had a negative association with sleep quality (P = .04). Conclusions: Findings indicate that well-being and high-intensity trainings can impair sleep duration and quality. In addition, high-intensity match load, away matches, and evening matches can impair postmatch sleep. Therefore, monitoring well-being in conjunction with TL is essential to understand sleep disturbances in athletes. Practitioners should also implement sleep hygiene strategies that facilitate longer time in bed after high-intensity, away, and evening matches to help athletes recover.
Improving Student Interview Preparation Through Collaborative Multimodal Mock-Interview Assignments
Authors: Anaza Emeka , Mabrey Paul , Sato Mikihiro , Miller Olivia , Thompson Julia
Published: February 2023

This research explored the usefulness of a mock-interview assignment through collaborative work between sport and recreation management faculty and communication center staff. The assignment paired entry-level undergraduate students working on mock-interviewing skills as job applicants with upper level undergraduate students acting as hiring managers for a series of mock interviews. Peer educators and faculty in the communication center conducted instructional workshops, provided direct student support and feedback, and facilitated the mock interviews. Data were collected on students’ insights of their job interview skills and career preparation during the 2019–20 academic year. The pivot to emergency remote learning during the spring 2020 semester led the assignment and research collection to happen virtually. The results and findings advocate the positive impact that role playing as hiring managers has on students, the effectiveness of students’ receiving multiple sources of feedback, and the value of virtual or online mock interviewing.
Fighting bias with bias: How same-race endorsements reduce racial discrimination on Airbnb
Authors: Park Minsu , Yu Chao , Macy Michael
Published: February 2023

Recent studies have documented racial discrimination in online interactions, mirroring the historic bias observed offline. The sharing economy is especially vulnerable due to greater dependence on mutual trust in sharing a ride, residence, or date with a stranger. These services rely on user recommendations to build trust, but the effects of these peer evaluations on racial bias are only beginning to be explored. Using data from Airbnb, we examine in-group preference for same-race hosts as well as same-race recommendations. The unexpected result is that these two manifestations of racial bias are offsetting, not reinforcing. White guests largely overcame their racial bias in host selection when hosts were endorsed by previous white guests. Moreover, we found no evidence of racial bias in the affective enthusiasm of endorsements, which suggests that the preference for same-race endorsements is motivated by the race of the recommender, not the content of the recommendation.
Spinal cord tissue engineering via covalent interaction between biomaterials and cells
Authors: Liu Weiyuan , Xu Bai , Zhao Shuaijing , Han Shuyu , Quan Rui , Liu Wenbin , Ji Chunnan , Chen Bing , Xiao Zhifeng , Yin Man , Yin Yanyun , Dai Jianwu , Zhao Yannan
Published: February 2023

Noncovalent interactions between cells and environmental cues have been recognized as fundamental physiological interactions that regulate cell behavior. However, the effects of the covalent interactions between cells and biomaterials on cell behavior have not been examined. Here, we demonstrate a combined strategy based on covalent conjugation between biomaterials (collagen fibers/lipid nanoparticles) and various cells (exogenous neural progenitor cells/astrocytes/endogenous tissue-resident cells) to promote neural regeneration after spinal cord injury (SCI). We found that metabolic azido-labeled human neural progenitor cells conjugated on dibenzocyclooctyne-modified collagen fibers significantly promoted cell adhesion, spreading, and differentiation compared with noncovalent adhesion. In addition, dibenzocyclooctyne-modified lipid nanoparticles containing edaravone, a well-known ROS scavenger, could target azide-labeled spinal cord tissues or transplanted azide-modified astrocytes to improve the SCI microenvironment. The combined application of these covalent conjugation strategies in a rat SCI model boosted neural regeneration, suggesting that the covalent interactions between cells and biomaterials have great potential for tissue regeneration.
A van der Waals heterojunction strategy to fabricate layer-by-layer single-molecule switch
Authors: Zou Yu-Ling , Liang Qing-Man , Lu Taige , Li Yao-Guang , Zhao Shiqiang , Gao Jian , Yang Zi-Xian , Feng Anni , Shi Jia , Hong Wenjing , Tian Zhong-Qun , Yang Yang
Published: February 2023

Single-molecule electronics offer a unique strategy for the miniaturization of electronic devices. However, the existing experiments are limited to the conventional molecular junctions, where a molecule anchors to the electrode pair with linkers. With such a rod-like configuration, the minimum size of the device is defined by the length of the molecule. Here, by incorporating a single molecule with two single-layer graphene electrodes, we fabricated layer-by-layer single-molecule heterojunctions called single-molecule two-dimensional van der Waals heterojunctions (M-2D-vdWHs), of which the sizes are defined by the thickness of the molecule. We controlled the conformation of the M-2D-vdWHs and the cross-plane charge transport through them with the applied electric field and established that they can serve as reversible switches. Our results demonstrate that the M-2D-vdWHs, as stacked from single-layer 2D materials and a single molecule, can respond to electric field stimulus, which promises a diverse class of single-molecule devices with unprecedented size.
An optical aptasensor for real-time quantification of endotoxin: From ensemble to single-molecule resolution
Authors: Zhu Pancheng , Papadimitriou Vasileios A. , van Dongen Jeanne E. , Cordeiro Julia , Neeleman Yannick , Santoso Albert , Chen Shuyi , Eijkel Jan C. T. , Peng Hanmin , Segerink Loes I. , Rwei Alina Y.
Published: February 2023

Endotoxin is a deadly pyrogen, rendering it crucial to monitor with high accuracy and efficiency. However, current endotoxin detection relies on multistep processes that are labor-intensive, time-consuming, and unsustainable. Here, we report an aptamer-based biosensor for the real-time optical detection of endotoxin. The endotoxin sensor exploits the distance-dependent scattering of gold nanoparticles (AuNPs) coupled to a gold nanofilm. This is enabled by the conformational changes of an endotoxin-specific aptamer upon target binding. The sensor can be used in an ensemble mode and single-particle mode under dark-field illumination. In the ensemble mode, the sensor is coupled with a microspectrometer and exhibits high specificity, reliability (i.e., linear concentration to signal profile in logarithmic scale), and reusability for repeated endotoxin measurements. Individual endotoxins can be detected by monitoring the color of single AuNPs via a color camera, achieving single-molecule resolution. This platform can potentially advance endotoxin detection to safeguard medical, food, and pharmaceutical products.
Peanut allergen inhibition prevents anaphylaxis in a humanized mouse model
Authors: Alakhras Nada S. , Shin Jaeho , Smith Scott A. , Sinn Anthony L. , Zhang Wenwu , Hwang Gyoyeon , Sjoerdsma Jenna , Bromley Emily K. , Pollok Karen E. , Bilgicer Basar , Kaplan Mark H.
Published: February 2023

Peanut-induced allergy is an immunoglobulin E (IgE)–mediated type I hypersensitivity reaction that manifests symptoms ranging from local edema to life-threatening anaphylaxis. Although there are treatments for symptoms in patients with allergies resulting from allergen exposure, there are few preventive therapies other than strict dietary avoidance or oral immunotherapy, neither of which are successful in all patients. We have previously designed a covalent heterobivalent inhibitor (cHBI) that binds in an allergen-specific manner as a preventive for allergic reactions. Building on previous in vitro testing, here, we developed a humanized mouse model to test cHBI efficacy in vivo. Nonobese diabetic–severe combined immunodeficient γc-deficient mice expressing transgenes for human stem cell factor, granulocyte-macrophage colony-stimulating factor, and interleukin-3 developed mature functional human mast cells in multiple tissues and displayed robust anaphylactic reactions when passively sensitized with patient-derived IgE monoclonal antibodies specific for peanut
Arachis hypogaea 2
(Ara h 2). The allergic response in humanized mice was IgE dose dependent and was mediated by human mast cells. Using this humanized mouse model, we showed that cHBI prevented allergic reactions for more than 2 weeks when administered before allergen exposure. cHBI also prevented fatal anaphylaxis and attenuated allergic reactions when administered shortly after the onset of symptoms. cHBI impaired mast cell degranulation in vivo in an allergen-specific manner. cHBI rescued the mice from lethal anaphylactic responses during oral Ara h 2 allergen–induced anaphylaxis. Together, these findings suggest that cHBI has the potential to be an effective preventative for peanut-specific allergic responses in patients.
Murine Gammaherpesvirus 68 ORF45 Stimulates B2 Retrotransposon and Pre-tRNA Activation in a Manner Dependent on Mitogen-Activated Protein Kinase (MAPK) Signaling
Authors: Lari Azra , Glaunsinger Britt A.
Published: February 2023

Gammaherpesviral infection alters the gene expression landscape of a host cell, including through the induction of noncoding RNAs transcribed by RNA polymerase III (RNAPIII). Among these are a class of repetitive genes known as retrotransposons, which are normally silenced elements and can copy and spread throughout the genome, and transfer RNAs (tRNAs), which are fundamental components of protein translation machinery.
Innovative COVID-19 point-of-care diagnostics suitable for tuberculosis diagnosis: a scoping review protocol
Authors: Yerlikaya Seda , Holtgrewe Lydia Marie-Luise , Broger Tobias , Isaacs Chris , Nahid Payam , Cattamanchi Adithya , Denkinger Claudia M
Published: February 2023

Introduction

In 2014, the WHO published high-priority target product profiles (TPPs) for new tuberculosis (TB) diagnostics to align end-user needs with test targets and specifications; nevertheless, no TB test meets these targets to date. The COVID-19-driven momentum in the diagnostics world offers an opportunity to address the long-standing lack of innovation in the field of TB diagnostics. This scoping review aims to summarise point-of-care (POC) molecular and antigen tests for COVID-19 diagnosis that, when applied to TB, potentially meet WHO TPPs. This summary of currently available innovative diagnostic tools will guide the development of novel TB diagnostics toward the WHO-set targets.

Methods and analysis

We will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension Scoping Reviews recommendations. MEDLINE (via PubMed), bioRxiv, MedRxiv and other publicly available in vitro diagnostic test databases were searched on 23 November 2022. POC antigen or molecular tests developed for SARS-CoV-2 detection that meet the eligibility criteria will be included in the review. Developer description, test description, operation characteristics, pricing information, performance and commercialisation status of diagnostic tests identified will be extracted using a predefined standardised data extraction form. Two reviewers will independently perform the screening and data extraction. A narrative synthesis of the final data will be provided.

Ethics and dissemination

No ethical approval is required because individual patient data will not be included. The findings will be published in open-access scientific journals.
Acetyltransferase fromAkkermansia muciniphilablunts colorectal tumourigenesis by reprogramming tumour microenvironment
Authors: Jiang Yi , Xu Yuejie , Zheng Chang , Ye Lei , Jiang Ping , Malik Sara , Xu Guifang , Zhou Qian , Zhang Mingming
Published: February 2023

Objective

The protein post-translational modification (PTM) in host cells can be rewritten by bacterial enzymes and represents an unprecedented mechanism in the communication between intestinal flora and the host. AlthoughAkkermansia muciniphilahas been widely investigated as a probiotic and blunts colitis-associated tumourigenesis in mice, there is little understanding regarding whetherA. muciniphilais involved in the PTM of colorectal cancer (CRC). This study investigates whether and howA. muciniphilaengages in the PTM of host CRC.

Design

The secreting extracellular vesicles fromA. muciniphilaand purified Amuc_2172 were used for different tumourigenesis mice models. Amuc_2172-induced immune activity of CD8+cytotoxic T lymphocytes (CTLs) were evaluated in vitro and in vivo. The acetyltransferase activity and downstream target genes of Amuc_2172 were investigated.

Results

Amuc_2172, a general control non-derepressible 5-related acetyltransferase ofA. muciniphila, was accessible to colorectal cells by macropinocytosis and functioned as an acetyltransferase of Lys14 on histone H3 (H3K14ac). Elevated H3K14ac onHspa1aloci promoted the transcription and secretion of heat-shock protein 70 (HSP70) in cancer cells. High level of HSP70 promoted the immune activity of CTLs in vitro and in vivo. Moreover, bioengineered nanoparticles provided a safe and reliable drug delivery strategy of Amuc_2172 for CRC treatment in an allograft mice model.

Conclusion

Amuc_2172 reprogrammed tumour microenvironment by inducing HSP70 secretion and promoting CTL-related immune response in the process of tumourigenesis.
Food insecurity and its association with health and well-being in middle-aged and older adults in India
Authors: Selvamani Y , Elgar Frank
Published: February 2023

Aim

Food insecurity is a global public health concern; however, there is limited knowledge about its health impacts in India. We examined the associations of food insecurity with socioeconomic conditions, chronic disease and various domains of health and well-being in a community sample of middle-aged and older adults (45+ years) in India.

Methods

Cross-sectional nationally representative data were collected in wave 1 (2017–2018) of the Longitudinal Ageing Study in India. Food insecurity was measured by questions of access and availability of food. We used logistic regression analyses to examine associations of food insecurity with poor self-rated health, limitations in activities of daily living (ADLs), instrumental ADLs, low life satisfaction, depression, sleep problems and low body mass.

Results

Food insecurity related to all seven indicators of poor health and well-being, even after controlling for material wealth and the presence of multimorbidity (which food insecurity also predicted). Associations with mental health were stronger for those for physical health. For instance, food insecurity related to a threefold increase in probable depression (OR=2.9, 95% CI=2.4 to 3.4) and low life satisfaction (OR=3.4, 95% CI=2.9 to 3.8).

Conclusions

Food insecurity is a powerful social determinant of poor health among older adults in India. Policy measures to improve population health and well-being should closely follow trends in food insecurity, particularly among those living in poverty and with multiple health conditions.
MUC1-C is a master regulator of MICA/B NKG2D ligand and exosome secretion in human cancer cells
Authors: Morimoto Yoshihiro , Yamashita Nami , Daimon Tatsuaki , Hirose Haruka , Yamano Shizuka , Haratake Naoki , Ishikawa Satoshi , Bhattacharya Atrayee , Fushimi Atsushi , Ahmad Rehan , Takahashi Hidekazu , Dashevsky Olga , Mitsiades Constantine , Kufe Donald
Published: February 2023

Background

The MUC1-C protein evolved in mammals to protect barrier tissues from loss of homeostasis; however, MUC1-C promotes oncogenesis in association with chronic inflammation. Aberrant expression of MUC1-C in cancers has been linked to depletion and dysfunction of T cells in the tumor microenvironment. In contrast, there is no known involvement of MUC1-C in the regulation of natural killer (NK) cell function.

Methods

Targeting MUC1-C genetically and pharmacologically in cancer cells was performed to assess effects on intracellular and cell surface expression of the MHC class I chain-related polypeptide A (MICA) and MICB ligands. TheMICA/Bpromoters were analyzed for H3K27 and DNA methylation. Shedding of MICA/B was determined by ELISA. MUC1-C interactions with ERp5 and RAB27A were assessed by coimmunoprecipitation and direct binding studies. Exosomes were isolated for analysis of secretion. Purified NK cells were assayed for killing of cancer cell targets.

Results

Our studies demonstrate that MUC1-C represses expression of the MICA and MICB ligands that activate the NK group 2D receptor. We show that the inflammatory MUC1-C→NF-κB pathway drives enhancer of zeste homolog 2-mediated and DNMT-mediated methylation of theMICAandMICBpromoter regions. Targeting MUC1-C genetically and pharmacologically with the GO-203 inhibitor induced intracellular and cell surface MICA/B expression but not MICA/B cleavage. Mechanistically, MUC1-C regulates the ERp5 thiol oxidoreductase that is necessary for MICA/B protease digestion and shedding. In addition, MUC1-C interacts with the RAB27A protein, which is required for exosome formation and secretion. As a result, targeting MUC1-C markedly inhibited secretion of exosomes expressing MICA/B. In concert with these results, we show that targeting MUC1-C promotes NK cell-mediated killing.

Conclusions

These findings uncover pleotropic mechanisms by which MUC1-C confers evasion of cancer cells to NK cell recognition and destruction.
Epidemiology of invasive Haemophilus influenzae disease in northwestern Ontario: comparison of invasive and noninvasive H. influenzae clinical isolates
Authors: Ulanova Marina , Tsang R.S.W. , Nix E.B. , Kelly L. , Shuel M. , Lance B. ,   for the Canadian Immunization Research Network Investigators
Published: February 2023

In the post- Haemophilus influenzae type b (Hib) vaccine era, invasive H. influenzae type a (Hia) disease emerged in North American Indigenous populations. The role of Hia in noninvasive disease is uncertain; it is unknown whether noninvasive Hia infections are prevalent in populations with a high incidence of invasive disease, and whether invasive and noninvasive Hia isolates have different characteristics. We analyzed all invasive and noninvasive clinical H. influenzae isolates collected in a northwestern Ontario hospital serving 82% Indigenous population over 5.5 years. Serotyping, clonal analysis, and antimicrobial sensitivity testing were conducted on 233 noninvasive and 20 invasive isolates. Among noninvasive isolates, 91% were nontypeable (NTHi) and 3% were Hia; Hia was the most frequent invasive isolate (60%). Incidence rates of invasive H. influenzae disease (12.5/100 000/year) greatly exceeded average provincial data, with the highest found in <6-year-old children (63.9/100 000/year); the proportion of Hia among invasive isolates was seven times larger than in Ontario. No difference in clonal characteristics between invasive and noninvasive Hia isolates was found. Antibiotic resistance was more common among NTHi than among encapsulated isolates, without differences between invasive and noninvasive isolates. Considering the significance of Hia in Indigenous populations, pediatric immunization against Hia will be useful to prevent serious infections in young Indigenous children.
Effects of Daqu properties on the microbial community and their metabolites in fermented grains in Baijiu fermentation system
Authors: Mao Fengjiao , Huang Jun , Zhou Rongqing , Qin Hui , Zhang Suyi , Cai Xiaobo , Qiu Chuanfeng
Published: February 2023

Daqu is the natural starter for Nong-flavor Baijiu brewing. The effects of Daqu properties on the microbial community succession and their metabolites in fermented grains (FG) during Baijiu brewing were determined. These results showed that the effect of Daqu on the bacterial communities was stronger than that of the fungal communities. Compared with the conventional Daqu (DZ), Taikong (TK), and Qianghua (QH), Daqu significantly enhanced the content of volatile metabolites (especially esters) and ethanol when they were used, respectively, for FG fermentation. In the second round of fermentation, the relative abundance of Lactobacillus decreased, the content of lactic acid decreased, and that of caproic acid increased. In particular, the abundance of Lactobacillus was also reduced by 20% in FGs of the second round when TK Daqu was used than that in the respective first round. Partial least squares structural equation model analysis also showed that physicochemical parameters and Daqu properties significantly affected FG community structure and metabolism. This study provides a theoretical basis for further study on the effect of high-quality Daqu on the quality of fresh Baijiu and lays an important theoretical foundation for the stabilization of the Baijiu fermentation system based on Daqu.
Patterns of free-living and particle-attached bacteria along environmental gradients in Lake Taihu
Authors: Xie Guijuan , Martin Robbie M. , Liu Changli , Zhang Li , Tang Xiangming
Published: February 2023

To elucidate the effects of environmental heterogeneity on diversity, composition, and degree of overlap between free-living (FL) and particle-attached (PA) bacteria, we sampled large, shallow, eutrophic Lake Taihu, China across gradients spanning riverine inflow, cyanobacterial blooms, and the open limnetic area. Using high-throughput sequencing of the 16S rRNA gene, we show that ( i) bacterial communities near riverine inflow had high α-diversity and a high degree of overlap between FL and PA lifestyles, ( ii) communities in cyanobacterial blooms have reduced α-diversity within the PA lifestyle, and ( iii) communities from the limnetic area had the lowest bacterial α-diversity within the FL lifestyle and a medium degree of overlap between the FL and PA lifestyles. Redundancy analysis showed that the variation of the FL bacterial community was shaped by suspended solids and total phosphorous, while the variation of the PA bacterial community was shaped by suspended solids, dissolved oxygen, and the percentage of organic matter in suspended solids. This study highlights the importance of environmental heterogeneity, riverine input, cyanobacterial blooms, and nutrient status on the spatial distribution patterns of FL and PA bacterial communities in freshwater lakes.