bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Property and Microstructure of IN718/FGH96 Dissimilar Superalloy Linear Friction Weldment
Authors: Wang Mingxiang , Geng Peihao , Ma Hong , Qin Guoliang
Published: September 2022

Wrought superalloy IN718 and powder metallurgy (P/M) FGH96 were joined by linear friction welding (LFW). The variation of microstructure and mechanical properties at different welding parameters has been investigated. Macrostructural examination of the double flash morphology indicated a conservative shortening length of 2.57 mm that was recommended to extrude out the original surface contaminants into the flash. Weld zone of the joint was featured with weld interface zone (WIZ) and thermo-mechanically affected zone (TMAZ), where deformed morphology tended to be more narrow with increasing applied pressure. The increasing oscillatory frequency or decreasing applied pressure promoted the refinement of dynamically recrystallised γ matrix grain. The analysis of electron backscatter diffraction (EBSD) mapping of the weldments showed that dynamic recrystallisation (DRX) occurred in the weld zone of dissimilar nickel-based superalloy. Continuous dynamic recrystallisation (CDRX) became the predominant behaviour, accompanied by inconspicuous discontinuous dynamic recrystallisation (DDRX). The scanning electron microscope (SEM) shows that dissolution of the strengthening phase occurred from WIZ to TMAZ, strongly influencing hardness distribution across the interface. Sound joints with a higher interface strength than the base metals of IN718 were obtained.
Influence of Silane Treatment on the Joint Properties During Laser Joining of Aluminum Alloy to CFRTP
Authors: Feng Ziwei , Zhang Xueyan , Su Jianhui , Liu Yifan , Zhao Hongyun , Chen Bo , Song Xiaoguo , Tan Caiwang
Published: September 2022

Achieving strong joining of aluminum alloy to carbon fiber thermoplastic composites (CFRTP) using laser heating was an essential method to reduce the weight of structure and save energy. In current study, a silane coupling agent was adopted on the aluminum alloy surface to improve the bonding strength of the laser joining of aluminum alloy to CFRTP. Substrate characteristics of the aluminum alloy after treatment including surface morphology, surface roughness and wettability as well as chemical composition were then studied. For comparison, identical experiments were also performed for the polished and sanded aluminum alloy. Compared to the aluminum alloy polished, the surface roughness of aluminum alloy sanded and silane treated was increased, whereas the wettability was both decreased. The rougher surface led to a worse wettability of aluminum alloy surface for these two specimens. In addition, the detected organo-functional group for the latter was also responsible for the increase of water contact angle on the aluminum alloy surface. Compared to the polished specimens, the tensile shear force of joints for sanded and silane-treated substrates averaged 1106.9N and 2959.4N respectively, which represents a respective increase of 1.2 times and 3.3 times than the polished state. Correspondingly, the tensile shear strength of joints was 6.3MPa and 16.8MPa, which was increased by 1.1 times and 2.9 times, respectively. The improved mechanical interlocking induced by increasing the surface roughness in both sanded and silane treated cases was considered to strengthen the bonding strength at the interface. Moreover, for the joints fabricated by aluminum alloy silane treated and CFRTP, the remarkable enhancement of joint strength was also related to the formation of silane coupling film on the aluminum alloy surface. The tensile shear properties of joints were also found to have a positive influence in increasing the adhesion amount of CFRTP on the fractured surface of aluminum alloy. Finally, the silane treatment was expected to play a significant role in joining aluminum alloy to CFRTP.
Global Disruption of Semiconductor Supply Chains During COVID-19: An Evaluation of Leading Causal Factors
Authors: Mohammed Aamirah , Khan Sardar Asif
Published: September 2022

The coronavirus pandemic has caused unprecedented supply chain disruptions globally, resulting in a heightened need for supply chain resilience. Particularly in the case of semiconductor chips, a commodity already in high demand, the existing challenges in supply chains have been aggravated by the pandemic. This global shortage is resulting in manufacturing disruptions across multiple sectors from automobiles to electronics. The global automobile industry alone is said to suffer a $210 billion loss in revenue from chip shortages. This highlights the cruciality of scientifically analyzing and building solutions that addresses the issue of resiliency of global semiconductor supply chains. While several news articles and white papers have reported this issue, there has been a lack of scientific literature on this topic. The objective of this paper is to identify the factors causing semiconductor shortage, analyze, and quantify their impact on the supply chain. This paper identifies 20 factors under 4 major categories from pre- and post-pandemic era, in the period ranging from 2018 to 2021, that have contributed to this disruption. The categories are: geopolitical tensions, natural disasters, logistics challenges and COVID-19 pandemic. The factors are ranked using the Analytical Hierarchy Process (AHP) methodology. The scientific value of this study lies in its contribution of quantifying and ranking the impact of the individual factors leading to the recent disruption in semiconductor supply chains. The results of this study will provide supply chain managers with the analytical information necessary for enabling resilient semiconductor supply chains as they navigate through these current challenges.
Development of an In-House Customized Perfusion-Based Bioreactor for 3D Cell Culture
Authors: Abbatiello Amar , Habib Md Ahasan
Published: September 2022

Bio-fabrication in the modern age is moving closer to creating viable three-dimensional scaffolds. Both cell-encapsulated and cell-seeded scaffolds need to be cultured to allow for proper cell viability and proliferation. Typical cell culturing methods, due to the three-dimensional nature of the scaffolds, are ineffective as stagnant or even moving mediums cannot enter or pass through the scaffold to reach all the areas inside. To compensate, perfusion bioreactors were developed where a systematic modification of this dynamic culture setup can improve the in vivo stimuli and conditions, and eventually, the overall performance of tissue regeneration. To do this, a set of design modifications were implemented expecting better performance. During operation, the success of an experiment can be difficult without the dynamic feedback due to the fully enclosed nature of a cell-seeded and cell-encapsulated scaffold. To compensate, oxygen sensors have been implemented before and after the perfusion chamber to track the oxygen being used by the cells during the incubation period, giving us a window into the cell’s proliferation. The prototype takes advantage of a dual medium tank design which allowed us to replace the medium without stopping or interrupting perfusion. A cyclical pressure modulation device has been implemented to better simulate in vivo conditions by modulating the pressure within the chamber, mimicking the natural pressure cues within the body such as the heartbeat and movement. The bioreactor will also take advantage of a newly designed perfusion chamber that can accommodate an array of cassettes allowing for a wide assortment of scaffold shapes and sizes.
Automatic Screw Detection and Tool Recommendation System for Robotic Disassembly
Authors: Zhang Xinyao , Eltouny Kareem , Liang Xiao , Behdad Sara
Published: September 2022

Disassembly is an essential process for the recovery of end-of-life (EOL) electronics in remanufacturing sites. Nevertheless, the process remains labor-intensive due to EOL electronics’ high degree of uncertainty and complexity. The robotic technology can assist in improving disassembly efficiency, however, the characteristics of EOL electronics pose difficulties for robot operation, such as removing small components. For such tasks, detecting small objects is critical for robotic disassembly systems. Screws are widely used as fasteners in ordinary electronic products while having small sizes and varying shapes in a scene. To achieve robotic disassembly of screws, the location information and the required tools need to be predicted. This paper proposes a framework to automatically detect screws and recommend related tools for disassembly. First, the YOLOv4 algorithm is used to detect screw targets in EOL electronic devices, and then a screw image extraction mechanism is executed based on the position coordinates predicted by YOLOv4. Second, after obtaining the screw images, the EfficientNetv2 algorithm is applied for screw shape classification. In addition to proposing a framework for automatic small-object detection, we explore how to modify the object detection algorithm to improve its performance and discuss the sensitivity of tool recommendations to the detection predictions. A case study of three different types of screws is used to evaluate the performance of the proposed framework.
Design and Manufacturing of a Functionally Graded Porous Dental Implant
Authors: Dabaja Rana , Popa Bogdan I. , Bak Sun-Yung , Mendonca Gustavo , Banu Mihaela
Published: September 2022

Dental implants are a prosthesis for missing teeth that are made to match a natural tooth. Current dental implants experience a high risk of failure in patients that have diseases affecting the oral region. When the patient experiences one or more of these diseases, the interface between the bone and implant is compromised and patients can experience low success rates or insufficient remaining bone structure. The purpose of this research is to create a dental implant technology that is suitable for both healthy and unhealthy patients. In the solutions studied, inducing pores into the Ti6Al4V implant proved to mimic the material properties of natural bone resulting in enhanced osseointegration. We plan to create an innovative solution with enhanced osseointegration that will ensure a gradient in mechanical properties. The complex geometry of the pore-induced dental implant is manufactured using the additive manufacturing method of selective laser melting (SLM). In this research, a functionally graded porous disk was designed using lattice-like pores to mimic the structure of bone. Multiple samples were created with 50-micron pores and printing was studied to test the capabilities of the SLM machine and resolution of the samples. It was found that the parameters play a role in the print resolution of the design. Additional porosity was induced through a keyhole effect during selective melting process.
Anomaly Scoring Model for Diagnosis on Machine Condition and Health Management
Authors: Joung Byung Gun , Li Zhongtian , Sutherland John W.
Published: September 2022

The reliability of manufacturing equipment is critical for ensuring the productivity and energy efficiency of a manufacturing facility. An unexpected machine breakdown may lead to unexpected downtime, disruption of manufacturing schedule, lower production efficiency, higher operation and maintenance cost. The recent development in machine learning and artificial intelligence enables data-driven Predictive Maintenance (PdM) by means of perceiving the dynamics of manufacturing systems and abstracting them into learnable features to provide a better interpretation of machine failures or unplanned downtimes. PdM, often translated to Prognostics and Health Management (PHM), aims to continue the optimal/normal operation of manufacturing systems. Often, vibration is used as a proxy of an early indicator of impending failure. In this study, tri-axial acceleration data collected from the two different machines are utilized. PdM-based strategies for machine condition monitoring and smart scheduling of equipment maintenance using an anomaly scoring model are discussed for two critical elements in a manufacturing system: 1) Chiller 2) Compressor. An anomaly scoring model is developed to extract meaningful information from the vibration data.
Development of an Interactive Digital Twin for Directed Energy Deposition (DED) Process
Authors: Noh Inwoong , Shin Hyewon , Choi Youngwoon , Lee Yongho , Jeon Yongjae , Lee Sang Won
Published: September 2022

Due to inherent drawbacks of metal 3D printing process such poor dimensional accuracy, surface quality, and various defects, a process monitoring system with an appropriate information visualization interface has been required. In the recent technological mega-trend, the 4th industrial revolution, the digital twin technology has received much attention to effectively monitor the process and transfer relevant information to operators. Therefore, in this paper, the interactive digital twin for a directed energy deposition (DED) process, which is one of representative metal 3D printing processes, is developed. First, the DED equipment digital twin is developed by creating a 3D model of the DED machine, and the motions of virtual components are synchronized with physical ones of the machine by attaching an inertial measurement unit (IMU) sensor to the DED head. Next, the DED process digital twin is developed by pooling objects based on the measured shape of the actual deposited parts. Finally, the DED equipment and process digital twins are combined together to simulate exactly the same as the actual system. Furthermore, the process monitoring function is realized by displaying temperature, shape and size of the melt-pool that are measured by a pyrometer and a CCD camera, respectively. In addition, the diagnosis results of the health state of the DED process are shown in the interactive digital twin.
Selective Laser Melting and Mechanical Properties of Oxide Dispersion Strengthened Haynes 214 Alloy
Authors: Poudel Bibek , Nguyen Hoa X. , O’Neil Aaron , Ahmad Mohsan Uddin , Qu Zhiyuan , Kwon Patrick , Chung Haseung
Published: September 2022

Haynes 214, a nickel-based superalloy, and its oxide dispersion-strengthened (ODS) versions (addition of 0.3, and 1.5 wt. % yttria (Y2O3)) have been successfully fabricated using selective laser melting (SLM). For each feedstock formulation, optimal processing conditions were identified and high temperature tensile testing coupons were produced. Feedstock preparation and laser scanning strategy have been proven to be critical in the dispersion of nanoparticles in the metal matrix, as well as preventing the formation of extensive crack networks. The impact of Y2O3 addition on the high-temperature tensile properties of Haynes 214 was evaluated and discussed.
3D Printing of Salvinia Water Fern-Inspired Superhydrophobic Structures
Authors: He Qingqing , Bethers Brandon , Tran Brian , Yang Yang
Published: September 2022

Certain types of Salvinia water ferns present a highly water-repellent upper surface along their floating leaves. This is accomplished through the use of structured trichomes, which create hydrophobic and superhydrophobic surfaces. Particularly, there are four different types of trichomes found in Salvinia plants that present these characteristics. They are known as Cucullata type, Oblongifolia type, Natans type and Molesta type. However, these structures are characterized by very small sizes, along with complex shapes. With the advantages of high-efficiency, low-cost, fast-fabrication, and ability of producing microstructures, additive manufacturing (AM), known as 3D printing method, has brought lots of attentions to various academic fields. Herein, we apply a 3D printing method to create biomimetic structures designed after the trichomes on Salvinia. In this work, the hydrophobic properties of the four biomimetic structures were tested through the use of optical contact angle measurements after initial modeling through the CAD program Solidworks. Finally, an Optical Contact Angle measurement device was used to determine the hydrophobic properties of each structure. This study concludes that each of the four biomimetic structures based on the different types of trichomes of Salvinia have hydrophobic performance. In particular, the Natans type and Molesta type show superhydrophobic properties, with the Molesta inspired structure displaying the highest contact angle among the four types. These results suggest that future research into the trichome structures of Salvinia water ferns could produce biomimetic structures with enhanced hydrophobic properties and applications.
Sequential Robust Parameter Design With Sample Size Selection
Authors: Lee Jaesung , Zhou Shiyu , Chen Junhong
Published: September 2022

In designing engineering systems, it is crucial to find a robust design whose responses have minimal variations and satisfies a constraint on the mean, also known as robust parameter design (RPD). Such optimization is challenging because collecting data is often expensive, and modern engineering systems commonly produce responses whose mean and variance are complex unknown functions of control variables. To address these challenges, we propose a stochastic constrained Bayesian optimization for RPD. We construct the Gaussian process dual response surrogate models for the mean and variance of the response by the sample mean and sample variance. The predicted mean and quantified uncertainties through the surrogate models are utilized to exploit the predictions and explore the regions with high uncertainty in the proposed Bayesian optimization method. Because the sample size of the sample mean and sample variance affects the performance significantly, we propose an effective sample size selection scheme, which effectively balances between exploitation and exploration during optimization. The performance of our method is demonstrated in numerical and case studies. In the case study, we used the real-world data for the robust design of the Graphene field-effect transistor nanosensors.
Smart Resin Vat: Real-Time Detecting Failures, Defects, and Curing Area in Vat Photopolymerization 3D Printing
Authors: Shan Yujie , Krishnakumar Aravind , Qin Zehan , Mao Huachao
Published: September 2022

Real-time and in-situ printing performance diagnostic in vat photopolymerization is critical to control printing quality, improve process reliability, and reduce wasted time and materials. This paper proposed a low-cost smart resin vat to monitor the printing process and detect the printing faults. Built on a conventional vat photopolymerization process, we added equally spaced thermistors along the edges of the resin vat. During printing, polymerization heat transferred to the edges of the resin vat, which increased thermistors’ temperature and enhanced resistances. The heat flux received at each thermistor varied with the distance to the place of photopolymerization. The temperature profiles of all thermistors were determined by the curing image pattern in each layer, and vice versa. Machine learning algorithms were leveraged to infer the printing status from the measured temperatures of these thermistors. Specifically, we proposed a simple and robust Failure Index to detect if the printing was active or terminated. Gaussian process regression was utilized to predict the printing area using the temperature recordings within a layer. The model was trained, validated, and tested using the data set collected by printing six parts. Different printing abnormalities, including printing failures, manual printing pause, and missing features (incorrect printing area), were successfully detected. The proposed approach modified the resin vat only and could be easily applied to all vat photopolymerization processes, including SLA, DLP, and LCD based 3D printing. The limitation and future work are also highlighted.
A Shape Registration Methodology for Geometric Deviation Correction in Additive Manufacturing
Authors: Wang Yuanxiang , Ruiz Cesar , Park Sanglok , Shin Kyeong-Ho , Kim Joo-Hyung , Huang Qiang
Published: September 2022

To reach the potential of additive manufacturing (AM) for accurate fabrication of complex geometries, extensive work has been done on developing prescriptive models for reducing shape deviations from the intended design. The efficacy of such models relies on proper alignment between the fabricated product and its intended design. However, the most popular registration procedures are extremely sensitive to local shape deformation and global distortion of the final product. This leads to incorrect assessments of the shape deviation patterns and making improvement efforts futile. This paper presents a new shape registration method robust to distortions to facilitate the correction or compensation of shape deviation in AM. It sequentially constrains rigid transformation parameters to reveal the true deformation of the product. A statistical control chart is adopted to filter the measurement data, which is later registered to the corresponding design for deviation identification. Simulation and case studies show that the proposed methodology provides consistent geometric quality assessments in the presence of global distortion compared to the existing methods.
Collaborative Filtering Recommendation Based Trust Evaluation Method for Cloud Manufacturing Service
Authors: Pei Jiang , Mingxing Wang , Xiaobin Li , Chao Yin
Published: September 2022

In the cloud manufacturing (CMfg) model, users can get various high-quality, efficient manufacturing services (MSs) on-demand through the connection between the Internet of things and cloud platforms. While the problem of the reliable identification of MSs is one of the keys to the efficient operation of the cloud platform and the popularization and application of CMfg. To address this problem, a trust evaluation index system and a credible evaluation model considered the similarity and recommendation reliability between users’ behaviors are proposed in this paper. Based on the analysis of the factors that affect the credibility of MSs in the cloud environment, the analytic hierarchy process (AHP) is introduced to calculate the weight of each trusted evaluation index. In addition, a trusted estimation method based on collaborative filtering recommendation algorithm (CFRA) is proposed to solve the model and judge whether the MSs are trusted to the target user according to the obtained predictive valuation value. Finally, compared with PSO and GA, an example is employed to demonstrate the validity and effectiveness of the model and method, which can find a trusted MS for users and greatly save retrieval time.
In situ spectroscopic ellipsometry and rigorous coupled wave analysis for real time profile evolution of atomic layer deposited films inside SiO2 nanotrenches
Authors: Berriel S. Novia , Feit Corbin , Keller Nick , Rudawski Nicholas G. , Banerjee Parag
Published: September 2022

Rigorous coupled wave analysis (RCWA) is conducted on in situ spectroscopic ellipsometry data to understand profile evolution during film deposition inside nanotrenches. Lithographically patterned SiO2 nanotrenches are used as test structures. The nanotrenches are 170 nm wide at the top with a taper angle of 4.5° and are 300 nm in depth. Atomic layer deposition of ZnO is used as a model process where the thickness (cycles) of the film is varied from 0 (0 cycles) to 46 nm (300 cycles). The analysis predicts transient behavior in deposition affecting film conformality and changes to the trench taper angle. In the process, the aspect ratio varies from 2.05 at the start of the process to 6.67 at the end. The model predicts changes in the refractive index of the ZnO film as a function of thickness. The real and imaginary parts of the refractive index at a wavelength of 350 nm change from 1.81 to 2.37 and 0.25 to 0.87, respectively. Scanning electron microscopy cross sections confirm thickness at the top and bottom of the trench to within 13% of those predicted by RCWA. The experimentally measured conformality degrades as film deposition proceeds from 97.3% at 100 cycles to 91.1% at 300 cycles. These results demonstrate the potential of using RCWA for continuous and in situ monitoring of growth inside 3D nanostructures.
Interleukin 1β and lipopolysaccharides induction dictate chondrocyte morphological properties and reduce cellular roughness and adhesion energy comparatively
Authors: Mallah Alia H. , Amr Mahmoud , Gozen Arda , Mendenhall Juana , Van-Wie Bernard J. , Abu-Lail Nehal I.
Published: September 2022

Osteoarthritis (OA) is a whole joint disease marked by the degradation of the articular cartilage (AC) tissue, chronic inflammation, and bone remodeling. Upon AC’s injury, proinflammatory mediators including interleukin 1β (IL1β) and lipopolysaccharides (LPS) play major roles in the onset and progression of OA. The objective of this study was to mechanistically detect and compare the effects of IL1β and LPS, separately, on the morphological and nanomechanical properties of bovine chondrocytes. Cells were seeded overnight in a full serum medium and the next day divided into three main groups: A negative control (NC) of a reduced serum medium and 10 ng/ml IL1ß or 10 ng/ml LPS-modified media. Cells were induced for 24 h. Nanomechanical properties (elastic modulus and adhesion energy) and roughness were quantified using atomic force microscopy. Nitric oxide, prostaglandin 2 (PGE2), and matrix metalloproteinases 3 (MMP3) contents; viability of cells; and extracellular matrix components were quantified. Our data revealed that viability of the cells was not affected by inflammatory induction and IL1ß induction increased PGE2. Elastic moduli of cells were similar among IL1β and NC while LPS significantly decreased the elasticity compared to NC. IL1ß induction resulted in least cellular roughness while LPS induction resulted in least adhesion energy compared to NC. Our images suggest that IL1ß and LPS inflammation affect cellular morphology with cytoskeleton rearrangements and the presence of stress fibers. Finally, our results suggest that the two investigated inflammatory mediators modulated chondrocytes’ immediate responses to inflammation in variable ways.
Growth behavior and substrate selective deposition of polypyrrole, polythiophene, and polyaniline by oxidative chemical vapor deposition and molecular layer deposition
Authors: Kim Jung-Sik , Oh Hwan , Parsons Gregory N.
Published: September 2022

Bottom-up self-aligned area-selective deposition (ASD) plays an important role in patterning of advanced electronic devices. Specifically, ASD of organic materials can be utilized for nucleation inhibitors, sacrificial layers, and air-gap materials for next-generation nanoscale processing. This work introduces fundamental growth behavior of various conjugated polymers including polypyrrole, polythiophene, and polyaniline via oxidative molecular layer deposition and chemical vapor deposition. Effects of process parameters on film properties are described, and ASD behavior of different polymers are quantitatively characterized. These findings expand fundamental understanding of conjugated polymer deposition and provide new perspectives for ASD of organic thin films.
Cell clusters adopt a collective amoeboid mode of migration in confined nonadhesive environments
Authors: Pagès Diane-Laure , Dornier Emmanuel , de Seze Jean , Gontran Emilie , Maitra Ananyo , Maciejewski Aurore , Wang Li , Luan Rui , Cartry Jérôme , Canet-Jourdan Charlotte , Raingeaud Joël , Lemahieu Grégoire , Lebel Marceline , Ducreux Michel , Gelli Maximiliano , Scoazec Jean-Yves , Coppey Mathieu , Voituriez Raphaël , Piel Matthieu , Jaulin Fanny
Published: September 2022

Cell migration is essential to living organisms and deregulated in cancer. Single cell’s migration ranges from traction-dependent mesenchymal motility to contractility-driven propulsive amoeboid locomotion, but collective cell migration has only been described as a focal adhesion–dependent and traction-dependent process. Here, we show that cancer cell clusters, from patients and cell lines, migrate without focal adhesions when confined into nonadhesive microfabricated channels. Clusters coordinate and behave like giant super cells, mobilizing their actomyosin contractility at the rear to power their migration. This polarized cortex does not sustain persistent retrograde flows, of cells or actin, like in the other modes of migration but rather harnesses fluctuating cell deformations, or jiggling. Theoretical physical modeling shows this is sufficient to create a gradient of friction forces and trigger directed cluster motion. This collective amoeboid mode of migration could foster metastatic spread by enabling cells to cross a wide spectrum of environments.
COVID-19 Exposure Assessment Tool (CEAT): Exposure quantification based on ventilation, infection prevalence, group characteristics, and behavior
Authors: Schimmoller Brian J. , Trovão Nídia S. , Isbell Molly , Goel Chirag , Heck Benjamin F. , Archer Tenley C. , Cardinal Klint D. , Naik Neil B. , Dutta Som , Rohr Daniel Ahleah , Beheshti Afshin
Published: September 2022

The coronavirus disease 2019 (COVID-19) Exposure Assessment Tool (CEAT) allows users to compare respiratory relative risk to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for various scenarios, providing understanding of how combinations of protective measures affect risk. CEAT incorporates mechanistic, stochastic, and epidemiological factors including the (i) emission rate of virus, (ii) viral aerosol degradation and removal, (iii) duration of activity/exposure, (iv) inhalation rates, (v) ventilation rates (indoors/outdoors), (vi) volume of indoor space, (vii) filtration, (viii) mask use and effectiveness, (ix) distance between people (taking into account both near-field and far-field effects of proximity), (x) group size, (xi) current infection rates by variant, (xii) prevalence of infection and immunity in the community, (xiii) vaccination rates, and (xiv) implementation of COVID-19 testing procedures. CEAT applied to published studies of COVID-19 transmission events demonstrates the model’s accuracy. We also show how health and safety professionals at NASA Ames Research Center used CEAT to manage potential risks posed by SARS-CoV-2 exposures.
Optically controllable magnetism in atomically thin semiconductors
Authors: Hao Kai , Shreiner Robert , Kindseth Andrew , High Alexander A.
Published: September 2022

We report evidence that ferromagnetic order in electrostatically doped, monolayer transition metal dichalcogenide (TMD) semiconductors can be stabilized and controlled at zero magnetic field by local optical pumping. We use circular dichroism (CD) in reflectivity from excitonic states as a spatially resolved probe of charge-carrier spin polarization. At electron densities

n
e

~ 10
12
cm
−2
, a diffraction-limited, circularly polarized optical pump breaks symmetry between oppositely polarized magnetic states and stabilizes long-range magnetic order, with carrier polarization exceeding 80% over an 8 μm by 5 μm extent. In time-resolved measurements with pulsed optical excitation, we observe that magnetic interactions amplify the initial pump-induced spin polarization by more than an order of magnitude. The optical control of magnetism with local optical pumps will unlock advancements in spin and optical technologies and provides a versatile tool in the study of correlated phases in two-dimensional electron gases.
cDC1 coordinate innate and adaptive responses in the omentum required for T cell priming and memory
Authors: Christian David A. , Adams Thomas A. , Shallberg Lindsey A. , Phan Anthony T. , Smith Tony E. , Abraha Mosana , Perry Joseph , Ruthel Gordon , Clark Joseph T. , Pritchard Gretchen Harms , Aronson Lillian R. , Gossa Selamawit , McGavern Dorian B. , Kedl Ross M. , Hunter Christopher A.
Published: September 2022

In the peritoneal cavity, the omentum contains fat-associated lymphoid clusters (FALCs) whose role in response to infection is poorly understood. After intraperitoneal immunization with
Toxoplasma gondii
, conventional type 1 dendritic cells (cDC1s) were critical to induce innate sources of IFN-γ and cellular changes in the FALCs. Unexpectedly, infected peritoneal macrophages that migrated into the FALCs primed CD8
+
T cells. Although T cell priming was cDC1 independent, these DCs were required for maximal CD8
+
T cell expansion. An agent-based computational model and experimental data highlighted that cDC1s affected the magnitude of the proliferative burst and promoted CD8
+
T cell expression of nutrient uptake receptors and cell survival. Thus, although FALCs lack the organization of secondary lymphoid organs, cDC1s resident in this tissue coordinate innate responses to microbial challenge and provide secondary signals required for T cell expansion and memory formation.
Illness behaviour and influencing aspects of general practitioners in Germany and their use of the health care system: a qualitative study
Authors: Schulz Sven , Hecker Friederike , Sauerbrey Ulf , Wolf Florian
Published: September 2022

Objectives

The aim of this study was to explore aspects that play a role when general practitioners (GPs) become ill and thus gain a more comprehensive understanding of the overall illness behaviour of GPs and their use of the healthcare system.

Setting

Primary care practices in Thuringia, Germany.

Participants

Convenience sample of 16 GPs.

Design

Qualitative study design with semistructured interviews and content analysis.

Results

Using our approach of having participants report their own episodes of illness, we found that self-treatment was practised and accepted by all 16 participants. The widespread use of naturopathy and complementary methods seems to be a special feature of German GPs. Formal use of the healthcare system mainly took place through direct consultation with specialists.

Our study revealed various aspects influencing the illness behaviour of the GPs and their use of the healthcare system. Some aspects also apply to lay patients, but it became clear how strongly illness behaviour is influenced by participants’ activities as physicians. Noteworthy and less described aspects are especially the influence of patients and practice staff, the influence of biographical and professional imprint and the attitudes and values of the physicians.

Complex inter-relationships were found between illness behaviour and influencing aspects; these are subjected to a dynamic and recursive process.

Conclusions

The illness behaviour of German GPs seems to be comprehensively influenced by their activities as responsible healthcare providers. The ability to perceive and reflect in this regards should already be actively promoted in studies and further education. Further research is needed for a better understanding of the inter-relationships.
Developing a core outcome set for physical activity interventions in primary schools: a modified-Delphi study
Authors: Ram Bina , Foley Kimberley A , van Sluijs Esther , Hargreaves Dougal S , Viner Russell M , Saxena Sonia
Published: September 2022

Objectives

To develop a core outcome set (COS) for physical activity interventions in primary schools.

Design

Modified-Delphi study.

Setting

The UK and international.

Participants

104 participants from four stakeholder groups (educators, public health professionals, health researchers, parents); 16 children (aged 8–9 years) from 1 London primary school.

Interventions

Physical activity interventions.

Methods

Four-stage process: (1) outcomes extracted from relevant studies identified from an umbrella review and a focus group; (2) list of outcomes produced and domains established; (3) stakeholders completed a two-round Delphi survey by rating (Round 1) and re-rating (Round 2) each outcome on a nine-point Likert Scale from ‘not important’ to ‘critical’: a>70% participant threshold identified the outcomes rated ‘critical’ to measure, and outcomes important to children were identified through a workshop; and (4) a stakeholder meeting to achieve consensus of the outcomes to include in the COS.

Results

In total, 74 studies were extracted from 53 reviews. A list of 50 outcomes was produced and three domains were established: ‘physical activity and health’ (16 outcomes), ‘social and emotional health’ (22 outcomes) and ‘educational performance’ (12 outcomes). 104 participants completed survey Round 1; 65 participants completed both rounds. In total, 13 outcomes met the threshold; children identified 8 outcomes. Fourteen outcomes achieved consensus to produce the COS: five outcomes for physical activity and health (diet (varied and balanced), energy, fitness, intensity of physical activity, sleep (number of hours)); seven outcomes for social and emotional health (anxiety, depression, enjoyment, happiness, self-esteem, stress, well-being); and two outcomes for educational performance (concentration, focus).

Conclusions

We have developed the first COS for physical activity interventions in primary schools in consultation with those interested in the development and application of an agreed standardised set of outcomes. Future studies including these outcomes will reduce heterogeneity across studies.

Trial registration number

Core Outcome Measures in Effectiveness Trials Initiative registration number 1322; Results.
Quantifying the contribution of smoking to regional mortality disparities in Germany: a cross-sectional study
Authors: Grigoriev Pavel , Klüsener Sebastian , van Raalte Alyson
Published: September 2022

Objectives

Substantial regional variation in smoking behaviour in Germany has been well documented. However, little is known about how these regional differences in smoking affect regional mortality disparities. We aim to assess the contribution of smoking to regional mortality differentials in Germany over the last four decades.

Design

A cross-sectional study using official cause-specific mortality data by German Federal State aggregated into five macro-regions: East, North, South, West-I and West-II.

Participants

The entire population of Germany stratified by sex, age and region during 1980–2019.

Main outcome measures

Smoking-attributable fraction estimated using the Preston-Glei-Wilmoth method; life expectancy at birth before and after the elimination of smoking-attributable deaths.

Results

In all macro-regions, the burden of past smoking has been declining among men but growing rapidly among women. The hypothetical removal of smoking-attributable deaths would eliminate roughly half of the contemporary advantage in life expectancy of the vanguard region South over the other macro-regions, apart from the East. In the latter, smoking only explains around a quarter (0.5 years) of the 2-year difference in male life expectancy compared with the South observed in 2019. Among women, eliminating smoking-attributable deaths would put the East in a more disadvantageous position compared with the South as well as the other macro-regions.

Conclusion

While regional differences in smoking histories explain large parts of the regional disparities in male mortality, they are playing an increasingly important role for female mortality trends and differentials. Health policies aiming at reducing regional inequalities should account for regional differences in past smoking behaviour.
Understanding eating behaviours, mental health and weight change in young adults: protocol paper for an international longitudinal study
Authors: Whatnall Megan , Fozard Therese , Kolokotroni Katerina Z , Marwood Jordan , Evans Tamla , Ells Louisa Jane , Burrows Tracy
Published: September 2022

Introduction

Understanding the complexities of change in eating behaviours, mental health, well-being and weight is crucial to inform healthcare and service provision, particularly in light of the exacerbating effects of the COVID-19 pandemic. This study aims to address the need for more comprehensive cross-sectional and longitudinal evidence, by tracking eating behaviours, mental health, health related behaviours and weight over a 12-month period, in a sample of young adults (18–35 years) in the UK and Australia.

Methods and analysis

Online surveys administered via the Prolific online research platform will be used for data collection at baseline, 6 months and 12 months. The survey (approximately 45 min) measures demographics, the impact of COVID-19, body mass index (BMI), weight management and health service usage, eating behaviours, personality, mental health, and health-related behaviours. An optional substudy component at each time point aims to validate self-reported weight in the main survey through images. Study inclusion criteria are; aged 18–34 years at baseline, BMI ≥20 kg/m2, and residing in the UK or Australia. A target of 500 participants at baseline was set, recruited through Prolific, and with recruitment stratified by BMI, sex and country. The proposed analyses include creating static predictive models using baseline data (eg, using latent class analysis, factor analysis or similar), and mapping changes longitudinally (eg, using multivariate regressions). These analyses will enable changes in the study measures to be identified, as well as predictors and outcomes of change.

Ethics and dissemination

Ethical approval was granted by Leeds Beckett University, UK (reference number 86004) and the University of Newcastle, Australia (reference number H-2022–0110). Study findings will be disseminated through scientific journals, conferences, institute websites and social media, and briefings tailored to policy, practice and the public, with the intention to help inform the future development of health and well-being care and support for young adults across Australia and the UK.
Total retinal thickness: a neglected factor in the evaluation of inner retinal thickness
Authors: Banghart Mark , Lee Kyungmoo , Bahrainian Mozhdeh , Staggers Kristen , Amos Christopher , Liu Yao , Domalpally Amitha , Frankfort Benjamin J , Sohn Elliott H , Abramoff Michael , Channa Roomasa
Published: September 2022

Aim

To determine whether macular retinal nerve fibre layer (mRNFL) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses vary by ethnicity after accounting for total retinal thickness.

Methods

We included healthy participants from the UK Biobank cohort who underwent macula-centred spectral domain-optical coherence tomography scans. mRNFL and GC-IPL thicknesses were determined for groups from different self-reported ethnic backgrounds. Multivariable regression models adjusting for covariables including age, gender, ethnicity and refractive error were built, with and without adjusting for total retinal thickness.

Results

20237 participants were analysed. Prior to accounting for total retinal thickness, mRNFL thickness was on average 0.9 μm (−1.2, –0.6; p<0.001) lower among Asians and 1.5 μm (−2.3, –0.6; p<0.001) lower among black participants compared with white participants. Prior to accounting for total retinal thickness, the average GC-IPL thickness was 1.9 μm (−2.5, –1.4; p<0.001) lower among Asians compared with white participants, and 2.4 μm (−3.9, –1.0; p=0.001) lower among black participants compared with white participants. After accounting for total retinal thickness, the layer thicknesses were not significantly different among ethnic groups. When considered as a proportion of total retinal thickness, mRNFL thickness was ~0.1 and GC-IPL thickness was ~0.2 across age, gender and ethnic groups.

Conclusions

The previously reported ethnic differences in layer thickness among groups are likely driven by differences in total retinal thickness. Our results suggest using layer thickness ratio (retinal layer thicknesses/total retinal thickness) rather than absolute thickness values when comparing retinal layer thicknesses across groups.
Does pre-injury clopidogrel use increase the risk of intracranial haemorrhage post head injury in adult patients? A systematic review and meta-analysis
Authors: Moffatt Samuel , Venturini Sara , Vulliamy Paul
Published: September 2022

Background

Several current guidelines do not include antiplatelet use as an explicit indication for CT scan of the head following head injury. The impact of individual antiplatelet agent use on rates of intracranial haemorrhage is unclear. The primary objective of this systematic review was to assess if clopidogrel monotherapy was associated with traumatic intracranial haemorrhage (tICH) on CT of the head within 24 hours of presentation following head trauma compared with no antithrombotic controls.

Methods

Eligible studies were non-randomised studies with participants aged ≥18 years old with head injury. Studies had to have conducted CT of the head within 24 hours of presentation and contain a no antithrombotic control group and a clopidogrel monotherapy group.

Eight databases were searched from inception to December 2020. Assessment of identified studies against inclusion criteria and data extraction were carried out independently and in duplicate by two authors.

Quality assessment and risk of bias (ROB) were assessed using the Newcastle–Ottawa Quality Assessment tool and Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. Meta-analysis was conducted using a random-effects model and reported as an OR and 95% CI.

Results

Seven studies were eligible for inclusion with a total of 21 898 participants that were incorporated into the meta-analysis. Five studies were retrospective. Clopidogrel monotherapy was not significantly associated with an increase in risk of tICH compared with no antithrombotic controls (OR 0.97, 95% CI 0.54 to 1.75). Heterogeneity was high with an I2of 75%. Sensitivity analysis produced an I2of 21% and did not show a significant association between clopidogrel monotherapy and risk of tICH (OR 1.16, 95% CI 0.87 to 1.55). All studies scored for moderate to serious ROB on categories in the ROBINS-I tool.

Conclusion

Included studies were vulnerable to confounding and several were small-scale studies. The results should be interpreted with caution given the ROB identified. This study does not provide statistically significant evidence that clopidogrel monotherapy patients are at increased risk of tICH after head injury compared with no antithrombotic controls.

PROSPERO registration number

CRD42020223541.
Does overruling Roe discriminate against women (of colour)?
Authors: Räsänen Joona , Gothreau Claire , Lippert-Rasmussen Kasper
Published: September 2022

On 24 July 2022, the landmark decision Roe v. Wade (1973), that secured a right to abortion for decades, was overruled by the US Supreme Court. The Court decision in Dobbs v. Jackson Women’s Health Organisation severely restricts access to legal abortion care in the USA, since it will give the states the power to ban abortion. It has been claimed that overruling Roe will have disproportionate impacts on women of color and that restricting access to abortion contributes to or amounts to structural racism. In this paper, we consider whether restricting abortion access as a consequence of overruling Roe could be understood as discrimination against women of color (and women in general). We argue that banning abortion is indirectly discriminatory against women of color and directly (but neither indirectly, nor structurally) discriminatory against women in general.