articles+ search results

Algorithm, Sensors -- Analysis, Wireless sensor networks -- Analysis, and Algorithms -- Analysis

Keywords Tissue P System; Wireless Sensor Network; Multi-Objective problem; Task Assignment; Decision Support System; Parallel computing; Sustainable computing Abstract The contemporary wireless sensor applications employ a Heterogeneous Wireless Sensor Network (HeWSN) to achieve its multi-objective missions. Modern wireless nodes constituting the HeWSN are more versatile in terms of its capabilities, functionalities, and applications. Assigning tasks in a dynamic HeWSN environment are challenging due to its inherent heterogeneous properties and capabilities. The investigation of existing task assignment algorithms reveals (i) the majority of the existing task assignment algorithms were designed for the homogeneous environment, (ii) most of the nature-inspired algorithms were built for centralized architecture. Scheduling tasks by existing task assignment algorithms lead to underutilization of resources as well as to the rapid depletion of network resources. To this end, a novel, distributed, heterogeneous task assignment algorithm adhering the modern sensors capabilities, functionalities and sensor application to attain sustainable computing is required. Based on the investigation, Tissue P-System inspired task assignment algorithm for the distributed heterogeneous WSN has been modelled. The experimental analyses of the proposed method have been self-evaluated as well as compared with the corresponding recent benchmark algorithms under various conditions and its performance metrics are analysed. Author Affiliation: Karunya Institute of Technology & Sciences, Coimbatore, Tamil Nadu 641 114, India * Corresponding author. Article History: Received 18 November 2019; Revised 11 June 2020; Accepted 21 June 2020 (footnote) Peer review under responsibility of King Saud University. Byline: Titus Issac [titusissac@gmail.com] (*), Salaja Silas, Elijah Blessing Rajsingh

Protein cages are attractive as molecular scaffolds for the fundamental study of enzymes and metabolons and for the creation of biocatalytic nanoreactors for in vitro and in vivo use. Virus-like particles (VLPs) such as those derived from the P22 bacteriophage capsid protein make versatile self-assembling protein cages and can be used to encapsulate a broad range of protein cargos. In vivo encapsulation of enzymes within VLPs requires fusion to the coat protein or a scaffold protein. However, the expression level, stability, and activity of cargo proteins can vary upon fusion. Moreover, it has been shown that molecular crowding of enzymes inside VLPs can affect their catalytic properties. Consequently, testing of numerous parameters is required for production of the most efficient nanoreactor for a given cargo enzyme. Here, we present a set of acceptor vectors that provide a quick and efficient way to build, test, and optimize cargo loading inside P22 VLPs. We prototyped the system using a yellow fluorescent protein and then applied it to mevalonate kinases (MKs), a key enzyme class in the industrially important terpene (isoprenoid) synthesis pathway. Different MKs required considerably different approaches to deliver maximal encapsulation as well as optimal kinetic parameters, demonstrating the value of being able to rapidly access a variety of encapsulation strategies. The vector system described here provides an approach to optimize cargo enzyme behavior in bespoke P22 nanoreactors. This will facilitate industrial applications as well as basic research on nanoreactor-cargo behavior.

Humans, Hydrogels, Microvessels, Neovascularization, Pathologic, Lab-On-A-Chip Devices, and Microtechnology

Reconstruction of 3D vascularized microtissues within microfabricated devices has rapidly developed in biomedical engineering, which can better mimic the tissue microphysiological function and accurately model human diseases in vitro . However, the traditional PDMS-based microfluidic devices suffer from the microfabrication with complex processes and usage limitations of either material properties or microstructure design, which drive the demand for easy processing and more accessible devices with a user-friendly interface. Here, we present an open microfluidic device through a rapid prototyping method by laser cutting in a cost-effective manner with high flexibility and compatibility. This device allows highly efficient and robust hydrogel patterning under a liquid guiding rail by spontaneous capillary action without the need for surface treatment. Different vascularization mechanisms including vasculogenesis and angiogenesis were performed to construct a 3D perfusable microvasculature inside a tissue chamber with various shapes under different microenvironment factors. Furthermore, as a proof-of-concept we have created a vascularized spheroid by placing a monoculture spheroid into the central through-hole of this device, which formed angiogenesis between the spheroid and microvascular network. This open microfluidic device has great potential for mass customization without the need for complex microfabrication equipment in the cleanroom, which can facilitate studies requiring high-throughput and high-content screening.

Electrodes and Ions chemistry

Traveling wave structures for lossless ion manipulation (TW-SLIM) has proven a valuable tool for the separation and study of gas-phase ions. Unfortunately, many of the traditional components of TW-SLIM experiments manifest practical and financial barriers to the technique's broad implementation. To this end, a series of technological innovations and methodologies are presented which enable for simplified SLIM experimentation and more rapid TW-SLIM prototyping. In addition to the use of multiple independent board sets that comprise the present SLIM system, we introduce a low-cost, multifunctional traveling wave generator to produce TW within the TW-SLIM. This square-wave producing unit proved effective in realizing TW-SLIM separations compared to traditional approaches. Maintaining a focus on lowering barriers to implementation, the present set of experiments explores the use of on-board injection (OBI) methods, which offer potential alternatives to ion funnel traps. These OBI techniques proved feasible and the ability of this simplified TW-SLIM platform to enhance ion accumulation was established. Further experimentation regarding ion accumulation revealed a complexity to ion accumulation within TW-SLIM that has yet to be expounded upon. Lastly, the ability of the presented TW-SLIM platform to store ions for extended periods (1 s) without significant loss (<10%) was demonstrated. The aforementioned experiments clearly establish the efficacy of a simplified TW-SLIM platform which promises to expand adoption and experimentation of the technique.
(Copyright © 2022 Elsevier B.V. All rights reserved.)

Gene Library, Protein Biosynthesis, Synthetic Biology, High-Throughput Screening Assays, and Microfluidics methods

Engineering regulatory parts for improved performance in genetic programs has played a pivotal role in the development of the synthetic biology cell programming toolbox. Here, we report the development of a novel high-throughput platform for regulatory part prototyping and analysis that leverages the advantages of engineered DNA libraries, cell-free protein synthesis (CFPS), high-throughput emulsion droplet microfluidics, standard flow sorting adapted to screen droplet reactions, and next-generation sequencing (NGS). With this integrated platform, we screened the activity of millions of genetic parts within hours, followed by NGS retrieval of the improved designs. This in vitro platform is particularly valuable for engineering regulatory parts of nonmodel organisms, where in vivo high-throughput screening methods are not readily available. The platform can be extended to multipart screening of complete genetic programs to optimize yield and stability.

Purpose: Virtual reality (VR) can provide an added value for diagnosis and/or intervention planning. Several VR software implementations have been proposed but they are often application dependent. Previous attempts for a more generic solution incorporating VR in medical prototyping software (MeVisLab) were still lacking functionality precluding easy and flexible development.
Methods: We propose an alternative solution that uses rendering to a graphical processing unit (GPU) texture to enable rendering arbitrary Open Inventor scenes in a VR context. It facilitates flexible development of user interaction and rendering of more complex scenes involving multiple objects. We tested the platform in planning a transcatheter cardiac stent placement procedure.
Results: This approach proved to enable development of a particular implementation that facilitates planning of percutaneous treatment of a sinus venosus atrial septal defect. The implementation showed it is intuitive to plan and verify the procedure using VR.
Conclusion: An alternative implementation for linking OpenVR with MeVisLab is provided that offers more flexible development of VR prototypes which can facilitate further clinical validation of this technology in various medical disciplines.
(© 2022. CARS.)

Autotrophic Processes, Fermentation, Oxidation-Reduction, Carbon Cycle, and Escherichia coli metabolism

Carbon-negative synthesis of biochemical products has the potential to mitigate global CO 2 emissions. An attractive route to do this is the reverse β-oxidation (r-BOX) pathway coupled to the Wood-Ljungdahl pathway. Here, we optimize and implement r-BOX for the synthesis of C4-C6 acids and alcohols. With a high-throughput in vitro prototyping workflow, we screen 762 unique pathway combinations using cell-free extracts tailored for r-BOX to identify enzyme sets for enhanced product selectivity. Implementation of these pathways into Escherichia coli generates designer strains for the selective production of butanoic acid (4.9 ± 0.1 gL -1 ), as well as hexanoic acid (3.06 ± 0.03 gL -1 ) and 1-hexanol (1.0 ± 0.1 gL -1 ) at the best performance reported to date in this bacterium. We also generate Clostridium autoethanogenum strains able to produce 1-hexanol from syngas, achieving a titer of 0.26 gL -1 in a 1.5 L continuous fermentation. Our strategy enables optimization of r-BOX derived products for biomanufacturing and industrial biotechnology.
(© 2022. The Author(s).)

The use of personal protective equipment (PPE) has become essential to reduce the transmission of coronavirus disease 2019 (COVID-19) as it prevents the direct contact of body fluid aerosols expelled from carriers. However, many countries have reported critical supply shortages due to the spike in demand during the outbreak in 2020. One potential solution to ease pressure on conventional supply chains is the local fabrication of PPE, particularly face shields, due to their simplistic design. The purpose of this paper is to provide a research protocol and cost implications for the rapid development and manufacturing of face shields by individuals or companies with minimal equipment and materials. This article describes a best practice case study in which the establishment of a local manufacturing hub resulted in the swift production of 12,000 face shields over a seven-week period to meet PPE shortages in the North-West region of Ireland. Protocols and processes for the design, materials sourcing, prototyping, manufacturing, and distribution of face shields are described. Three types of face shields were designed and manufactured, including Flat, Laser-cut, and 3D-printed models. Of the models tested, the Flat model proved the most cost-effective (€0.51/unit), while the Laser-cut model was the most productive (245 units/day). The insights obtained from this study demonstrate the capacity for local voluntary workforces to be quickly mobilised in response to a healthcare emergency, such as the COVID-19 pandemic.
(© 2022 The Authors.)

This paper demonstrates laser forming, localized heating with a laser to induce plastic deformation, can self-fold 2D printed circuit boards (PCBs) into 3D structures with electronic function. There are many methods for self-folding but few are compatible with electronic materials. We use a low-cost commercial laser writer to both cut and fold a commercial flexible PCB. Laser settings are tuned to select between cutting and folding with higher power resulting in cutting and lower power resulting in localized heating for folding into 3D shapes. Since the thin copper traces used in commercial PCBs are highly reflective and difficult to directly fold, two approaches are explored for enabling folding: plating with a nickel/gold coating or using a single, high-power laser exposure to oxidize the surface and improve laser absorption. We characterized the physical effect of the exposure on the sample as well as the fold angle as a function of laser passes and demonstrate the ability to lift weights comparable with circuit packages and passive components. This technique can form complex, multifold structures with integrated electronics; as a demonstrator, we fold a commercial board with a common timing circuit. Laser forming to add a third dimension to printed circuit boards is an important technology to enable the rapid prototyping of complex 3D electronics.

Exoskeletons and more in general wearable mechatronic devices represent a promising opportunity for rehabilitation and assistance to people presenting with temporary and/or permanent diseases. However, there are still some limits in the diffusion of robotic technologies for neuro-rehabilitation, notwithstanding their technological developments and evidence of clinical effectiveness. One of the main bottlenecks that constrain the complexity, weight, and costs of exoskeletons is represented by the actuators. This problem is particularly evident in devices designed for the upper limb, and in particular for the hand, in which dimension limits and kinematics complexity are particularly challenging. This study presents the design and prototyping of a hand finger exoskeleton. In particular, we focus on the design of a gear-based differential mechanism aimed at coupling the motion of two adjacent fingers and limiting the complexity and costs of the system. The exoskeleton is able to actuate the flexion/extension motion of the fingers and apply bidirectional forces, that is, it is able to both open and close the fingers. The kinematic structure of the finger actuation system has the peculiarity to present three DoFs when the exoskeleton is not worn and one DoF when it is worn, allowing better adaptability and higher wearability. The design of the gear-based differential is inspired by the mechanism widely used in the automotive field; it allows actuating two fingers with one actuator only, keeping their movements independent.
(Copyright © 2022 Dragusanu, Troisi, Villani, Prattichizzo and Malvezzi.)

Electrodes, Ion-Selective Electrodes, Ions, Potassium, Potentiometry, Printing, Three-Dimensional, Sodium, Internet of Things, and Robotics

We report automated fabrication of solid-contact sodium-selective (Na + -ISEs) and potassium-selective electrodes (K + -ISEs) using a 3D printed liquid handling robot controlled with Internet of Things (IoT) technology. The printing system is affordable and can be customized for the use with micropipettes for applications such as drop-casting, biological assays, sample preparation, rinsing, cell culture, and online analyte monitoring using multi-well plates. The robot is more compact (25 × 30 × 35 cm) and user-friendly than commercially available systems and does not require mechatronic experience. For fabrication of ion-selective electrodes, a carbon black intermediate layer and ion-selective membrane were successively drop-cast on the surface of stencil-printed carbon electrode using the dispensing robot. The 3D-printed robot increased ISE robustness while decreasing the modification time by eliminating manual steps. The Na + -ISEs and K + -ISEs were characterized for their potentiometric responses using a custom-made, low-cost (<$25) multi-channel smartphone-based potentiometer capable of signal processing and wireless data transmission. The electrodes showed Nernstian responses of 58.2 ± 2.6 mV decade -1 and 56.1 ± 0.7 mV decade -1 for Na + and K + , respectively with an LOD of 1.0 × 10 -5  M. We successfully applied the ISEs for multiplexed detection of Na + and K + in urine and artificial sweat samples at clinically relevant concentration ranges. The 3D-printed pipetting robot cost $100 and will pave the way for more accessible mass production of ISEs for those who cannot afford the expensive commercial robots.
(Copyright © 2022 Elsevier B.V. All rights reserved.)

Humans, Intelligence, and Software

Sensor networks have dynamically expanded our ability to monitor and study the world. Their presence and need keep increasing, and new hardware configurations expand the range of physical stimuli that can be accurately recorded. Sensors are also no longer simply recording the data, they process it and transform into something useful before uploading to the cloud. However, building sensor networks is costly and very time consuming. It is difficult to build upon other people's work and there are only a few open-source solutions for integrating different devices and sensing modalities. We introduce REIP, a Reconfigurable Environmental Intelligence Platform for fast sensor network prototyping. REIP's first and most central tool, implemented in this work, is an open-source software framework, an SDK, with a flexible modular API for data collection and analysis using multiple sensing modalities. REIP is developed with the aim of being user-friendly, device-agnostic, and easily extensible, allowing for fast prototyping of heterogeneous sensor networks. Furthermore, our software framework is implemented in Python to reduce the entrance barrier for future contributions. We demonstrate the potential and versatility of REIP in real world applications, along with performance studies and benchmark REIP SDK against similar systems.

Despite evidence associating the use of mechanical circulatory support (MCS) devices with increased survival and quality of life in patients with advanced heart failure (HF), significant complications and high costs limit their clinical use. We aimed to design an innovative MCS device to address three important needs: low cost, minimally invasive implantation techniques, and low risk of infection. We used mathematical modeling to calculate the pump characteristics to deliver variable flows at different pump diameters, turbomachinery design software CFturbo (2020 R2.4 CFturbo GmbH, Dresden, Germany) to create the conceptual design of the pump, computational fluid dynamics analysis with Solidworks Flow Simulation to in silico test pump performance, Solidworks (Dassault Systèmes SolidWorks Corporation, Waltham, MA, USA) to further refine the design, 3D printing with polycarbonate filament for the initial prototype, and a stereolithography printer (Form 2, Formlabs, Somerville, MA, USA) for the second variant materialization. We present the concept, design, and early prototyping of a low-cost, minimally invasive, fully implantable in a subcutaneous pocket MCS device for long-term use and partial support in patients with advanced HF which unloads the left heart into the arterial system containing a rim-driven, hubless axial-flow pump and the wireless transmission of energy. We describe a low-cost, fully implantable, low-invasive, wireless power transmission left ventricular assist device that has the potential to address patients with advanced HF with higher impact, especially in developing countries. In vitro testing will provide input for further optimization of the device before proceeding to a completely functional prototype that can be implanted in animals.

Electrodes, Glucose, Gold chemistry, Hydrogen Peroxide, Silver, Electrochemical Techniques, and Microfluidics

We present a low-cost, accessible, and rapid fabrication process for electrochemical microfluidic sensors. This work leverages the accessibility of consumer-grade electronic craft cutters as the primary tool for patterning of sensor electrodes and microfluidic circuits, while commodity materials such as gold leaf, silver ink pen, double-sided tape, plastic transparency films, and fabric adhesives are used as its base structural materials. The device consists of three layers, the silver reference electrode layer at the top, the PET fluidic circuits in the middle and the gold sensing electrodes at the bottom. Separation of the silver reference electrode from the gold sensing electrodes reduces the possibility of cross-contamination during surface modification. A novel approach in mesoscale patterning of gold leaf electrodes can produce generic designs with dimensions as small as 250 μm. Silver electrodes with dimensions as small as 385 μm were drawn using a plotter and a silver ink pen, and fluid microchannels as small as 300 μm were fabricated using a sandwich of iron-on adhesives and PET. Device layers are then fused together using an office laminator. The integrated microfluidic electrochemical platform has electrode kinetics/performance of Δ Ep = 91.3 mV, Ipa / Ipc = 0.905, characterized by cyclic voltammetry using a standard ferrocyanide redox probe, and this was compared against a commercial screen-printed gold electrode (Δ Ep = 68.9 mV, Ipa / Ipc = 0.984). To validate the performance of the integrated microfluidic electrochemical platform, a catalytic hydrogen peroxide sensor and enzyme-coupled glucose biosensors were developed as demonstrators. Hydrogen peroxide quantitation achieves a limit of detection of 0.713 mM and sensitivity of 78.37 μA mM -1 cm -2 , while glucose has a limit of detection of 0.111 mM and sensitivity of 12.68 μA mM -1 cm -2 . This rapid process allows an iterative design-build-test cycle in under 2 hours. The upfront cost to set up the system is less than USD 520, with each device costing less than USD 0.12, making this manufacturing process suitable for low-resource laboratories or classroom settings.

Background: Augmented reality (AR) and brain-computer interface (BCI) are promising technologies that have a tremendous potential to revolutionize health care. While there has been a growing interest in these technologies for medical applications in the recent years, the combined use of AR and BCI remains a fairly unexplored area that offers significant opportunities for improving health care professional education and clinical practice. This paper describes a recent study to explore the integration of AR and BCI technologies for health care applications.
Objective: The described effort aims to advance an understanding of how AR and BCI technologies can effectively work together to transform modern health care practice by providing new mechanisms to improve patient and provider learning, communication, and shared decision-making.
Methods: The study methods included an environmental scan of AR and BCI technologies currently used in health care, a use case analysis for a combined AR-BCI capability, and development of an integrated AR-BCI prototype solution for health care applications.
Results: The study resulted in a novel interface technology solution that enables interoperability between consumer-grade wearable AR and BCI devices and provides the users with an ability to control digital objects in augmented reality using neural commands. The article discusses this novel solution within the context of practical digital health use cases developed during the course of the study where the combined AR and BCI technologies are anticipated to produce the most impact.
Conclusions: As one of the pioneering efforts in the area of AR and BCI integration, the study presents a practical implementation pathway for AR-BCI integration and provides directions for future research and innovation in this area.
(©Anya Andrews. Originally published in JMIR Formative Research (https://formative.jmir.org), 21.04.2022.)

Crown Lengthening, Humans, Printing, Three-Dimensional, Stereolithography, Computer-Aided Design, and Dental Implants

Progress with additive 3D printing is revolutionizing biomaterial manufacturing, including clinical dentistry and prosthodontics. Among the several 3D additive printing technologies, stereolithography is very popular as it utilizes light-activated resin for precise resolution. A simplified digital technique was used to fabricate two designs of a surgical guide for crown lengthening. Two cases are presented that utilized digital imaging and communications in medicine (DICOM) files obtained with computed tomography (CT) imaging and processed using four CAD software (Blue Sky Plan, Exocad, Meshmixer and 3D Slicer). The final models were converted to standard tessellation (STL) files and the guides were 3D printed with an additive stereolithography (SLA) printer. The first case was fabricated with a bone model from cone beam computed tomography (CBCT) data, and the second case was generated with intraoral and wax-up scans alone. Both methods appear to be equally effective compared to using a conventional method of guide frabication. However, proximal bone reduction was a concern with both designs. Digitally fabricated 3D printed surgical guide for crown lengthening has merit and a practical design is needed for future clinical validation.
(© 2021 by the American College of Prosthodontists.)

Transforming lab research into a sustainable business is becoming a trend in the microfluidic field. However, there are various challenges during the translation process due to the gaps between academia and industry, especially from laboratory prototyping to industrial scale-up production, which is critical for potential commercialization. In this Perspective, based on our experience in collaboration with stakeholders, e.g., biologists, microfluidic engineers, diagnostic specialists, and manufacturers, we aim to share our understanding of the manufacturing process chain of microfluidic cartridge from concept development and laboratory prototyping to scale-up production, where the scale-up production of commercial microfluidic cartridges is highlighted. Four suggestions from the aspect of cartridge design for manufacturing, professional involvement, material selection, and standardization are provided in order to help scientists from the laboratory to bring their innovations into pre-clinical, clinical, and mass production and improve the manufacturability of laboratory prototypes toward commercialization.
(© 2022 Author(s).)

Gait, Humans, Neural Networks, Computer, Recognition, Psychology, Apathy, and Wearable Electronic Devices

Human gait is a unique behavioral characteristic that can be used to recognize individuals. Collecting gait information widely by the means of wearable devices and recognizing people by the data has become a topic of research. While most prior studies collected gait information using inertial measurement units, we gather the data from 40 people using insoles, including pressure sensors, and precisely identify the gait phases from the long time series using the pressure data. In terms of recognizing people, there have been a few recent studies on neural network-based approaches for solving the open set gait recognition problem using wearable devices. Typically, these approaches determine decision boundaries in the latent space with a limited number of samples. Motivated by the fact that such methods are sensitive to the values of hyper-parameters, as our first contribution, we propose a new network model that is less sensitive to changes in the values using a new prototyping encoder-decoder network architecture. As our second contribution, to overcome the inherent limitations due to the lack of transparency and interpretability of neural networks, we propose a new module that enables us to analyze which part of the input is relevant to the overall recognition performance using explainable tools such as sensitivity analysis (SA) and layer-wise relevance propagation (LRP).

Algorithms -- Analysis and Algorithm

Adult, Dental Pulp Cavity, Humans, Root Canal Therapy, Tooth Root, Transplantation, Autologous, Treatment Outcome, Surgery, Computer-Assisted, and Tooth

Background: Autotransplantation is a beneficial treatment with a high success rate for young patients. However, most adult patients require root canal treatment (RCT) of the donor teeth after the autotransplantation procedure, which causes a prolonged treatment time and additional expenses and increases the rate of future tooth fracture. Rapid prototyping (RP)-assisted autotransplantation shortens the extra-alveolar time and enables a superior clinical outcome. However, no cohort studies of the application of this method on adult populations have been reported.
Methods: This study is a retrospective cohort study. All patients underwent autotransplantation from 2012 to 2020 in the Kaohsiung and Chia-Yi branches of Chang Gung Memorial Hospital, and the procedure and clinical outcomes were analysed. Differences in clinical outcomes, age, sex, extra-alveolar time, fixation method, and RCT rate were compared between the two groups.
Results: We enrolled 21 patients, 13 treated using the conventional method and 8 treated using the RP-based technique. The RCT rates of the conventional group and RP group were 92.3% and 59%, respectively. The mean age of the two groups was significantly different (28.8 ± 10 vs. 21.6 ± 2.1); after performing subgroup analysis by excluding all of the patients aged > 40 years, we found that the RCT rates were still significantly different (91.0% vs. 50%). The mean extra-alveolar time was 43 s in the RP group, and the autotransplantation survival rate in both groups was 100%.
Conclusions: Rapid prototyping-assisted autotransplantation was successfully adopted for all patients in our study population. By shortening the extra-alveolar time, only 50% of the patients required a root canal treatment with a 100% autotransplantation survival rate.
Trial Registration: Retrospectively registered.
(© 2022. The Author(s).)

Teaching -- Usage, Teaching -- Methods, and Teaching -- Study and teaching

Given the ubiquity of interfaces on computing devices, it is essential for future Information Systems (IS) professionals to understand the ramifications of good user interface (UI) design. This article provides instructions on how to efficiently and effectively teach IS students about "fit," a Human-Computer Interaction (HCI) concept, through a paper prototyping activity. Although easy to explain, the concept of "fit" can be difficult to understand without repeated practice. Practically, designing "fit" into UIs can be cost-prohibitive because working prototypes are often beyond students' technical skillset. Accordingly, based on principles of active learning, we show how to use paper prototyping to demonstrate "fit" in a hands-on class exercise. We provide detailed stepby-step instructions to plan, setup, and present the exercise to guide students through the process of "fit" in UI design. As a result of this activity, students are better able to employ both theoretical and practical applications of "fit" in UI design and implementation. This exercise is applicable in any course that includes UI design, such as principles of HCI, systems analysis and design, software engineering, and project management. Keywords: Human-computer interaction (HCI), Paper prototyping, Active learning, Constructionism, Teaching tip
1. INTRODUCTION With computing devices peppering nearly every aspect of our lives, how people interact with these technologies is critically important to all computing fields. In fact, failure to properly [...]

Capillary Action, Polymers, Porosity, Lab-On-A-Chip Devices, and Microfluidics

Paper-based microfluidics was initially developed for use in ultra-low-cost diagnostics powered passively by liquid wicking. However, there is significant untapped potential in using paper to internally guide porous microfluidic flows using externally applied pressure gradients. Here, we present a new technique for fabricating and utilizing low-cost polymer-laminated paper-based microfluidic devices using external pressure. Known as microfluidic pressure in paper (μPiP), devices fabricated by this technique are capable of sustaining a pressure gradient for use in precise liquid handling and manipulation applications similar to conventional microfluidic open-channel designs, but instead where fluid is driven directly through the porous paper structure. μPiP devices can be both rapidly prototyped or scalably manufactured and deployed at commercial scale with minimal time, equipment, and training requirements. We present an analysis of continuous pressure-driven flow in porous paper-based microfluidic channels and demonstrate broad applicability of this method in performing a variety of different liquid handling applications, including measuring red blood cell deformability and performing continuous free-flow DNA electrophoresis. This new platform offers a budget-friendly method for performing microfluidic operations for both academic prototyping and large-scale commercial device production.

Electrochemical Techniques, Electrodes, Microfluidics, Aptamers, Nucleotide, and Biosensing Techniques

We demonstrate the ability to rapidly prototype and fabricate an epoxy-embedded electrode platform and microfluidic device suitable for using electrochemical biosensors under flow conditions. We utilize three-dimensional (3-D) printing to rapidly prototype molds to fabricate epoxy-embedded electrodes in addition to molds for rapid prototyping of PDMS microfluidic components. We characterize the bare gold epoxy-embedded electrodes using ferricyanide as a redox indicator and then characterize the performance of an adenosine triphosphate (ATP) specific electrochemical, aptamer-based (E-AB) sensor. We then incorporate the ATP specific E-AB sensors into the microfluidic device to study and take advantage of the dynamic response this class of sensor offers. We were able to flow varying concentrations of target analyte and monitor the dynamic response of the sensors to the changing concentration. This work demonstrates the ability to rapidly prototype E-AB sensors under flow conditions using 3-D printing which can lead to rapid and affordable point-of-care or fieldable applications where dynamic measurements of concentration, specificity and sensitivity and multiplex detection are necessary.
(Copyright © 2021 Elsevier B.V. All rights reserved.)

Culture Media, Plastics, Workflow, Laboratories, and Printing, Three-Dimensional

Although the microbiology laboratory paradigm has increasingly changed from manual to automated procedures, and from functional to molecular methods, traditional culture methods remain vital. Using inexpensive desktop fused filament fabrication 3D printing, we designed, produced and tested rapid prototypes of customised labware for microbial culture namely frames to make dip slides, inoculation loops, multi-pin replicators, and multi-well culture plates for solid medium. These customised components were used to plate out samples onto solid media in various formats, and we illustrate how they can be suitable for many microbiological methods such as minimum inhibitory concentration tests, or for directly detecting pathogens from mastitis samples, illustrating the flexibility of rapid-prototyped culture consumable parts for streamlining microbiological methods. We describe the methodology needed for microbiologists to develop their own novel and unique tools, or to fabricate and customise existing consumables. A workflow is presented for designing and 3D printing labware and quickly producing easy-to-sterilise and re-useable plastic parts of great utility in the microbiology laboratory.
(© 2021 The Society for Applied Microbiology.)

Animals, Antibodies, Cost-Benefit Analysis, Data Interpretation, Statistical, Disulfides, Drosophila melanogaster, Escherichia coli, Female, Gene Expression Regulation drug effects, Humans, Leishmania, Peptides genetics, Protein Aggregates, Protein Domains, RNA, Ribosomal, 16S, Synthetic Biology, Thermodynamics, Cell-Free System drug effects, Drugs, Generic chemistry, Drugs, Generic pharmacology, Peptides chemistry, and Peptides pharmacology

Advances in peptide and protein therapeutics increased the need for rapid and cost-effective polypeptide prototyping. While in vitro translation systems are well suited for fast and multiplexed polypeptide prototyping, they suffer from misfolding, aggregation and disulfide-bond scrambling of the translated products. Here we propose that efficient folding of in vitro produced disulfide-rich peptides and proteins can be achieved if performed in an aggregation-free and thermodynamically controlled folding environment. To this end, we modify an E. coli-based in vitro translation system to allow co-translational capture of translated products by affinity matrix. This process reduces protein aggregation and enables productive oxidative folding and recycling of misfolded states under thermodynamic control. In this study we show that the developed approach is likely to be generally applicable for prototyping of a wide variety of disulfide-constrained peptides, macrocyclic peptides with non-native bonds and antibody fragments in amounts sufficient for interaction analysis and biological activity assessment.
(© 2022. The Author(s).)

Background: Medical students show low levels of e-mental health literacy. Moreover, there is a high prevalence of common mental illnesses among medical students. Mobile health (mHealth) apps can be used to maintain and promote medical students' well-being. To date, the potential of mHealth apps for promoting mental health among medical students is largely untapped because they seem to lack familiarity with mHealth. In addition, little is known about medical students' preferences regarding mHealth apps for mental health promotion. There is a need for guidance on how to promote competence-based learning on mHealth apps in medical education.
Objective: The aim of this case study is to pilot an innovative concept for an educative workshop following a participatory co-design approach and to explore medical students' preferences and ideas for mHealth apps through the design of a hypothetical prototype.
Methods: We conducted a face-to-face co-design workshop within an elective subject with 26 participants enrolled at a medical school in Germany on 5 consecutive days in early March 2020. The aim of the workshop was to apply the knowledge acquired from the lessons on e-mental health and mHealth app development. Activities during the workshop included group work, plenary discussions, storyboarding, developing personas (prototypical users), and designing prototypes of mHealth apps. The workshop was documented in written and digitalized form with the students' permission.
Results: The participants' feedback suggests that the co-design workshop was well-received. The medical students presented a variety of ideas for the design of mHealth apps. Among the common themes that all groups highlighted in their prototypes were personalization, data security, and the importance of scientific evaluation.
Conclusions: Overall, this case study indicates the feasibility and acceptance of a participatory design workshop for medical students. The students made suggestions for improvements at future workshops (eg, use of free prototype software, shift to e-learning, and more time for group work). Our results can be (and have already been) used as a starting point for future co-design workshops to promote competence-based collaborative learning on digital health topics in medical education.
(©Melina Dederichs, Felix Jan Nitsch, Jennifer Apolinário-Hagen. Originally published in JMIR Medical Education (https://mededu.jmir.org), 10.01.2022.)

Designs of soft actuators are mostly guided and limited to certain target functionalities. This article presents a novel programmable design for soft pneumatic bellows-shaped actuators with distinct motions, thus a wide range of functionalities can be engendered through tuning channel parameters. According to the design principle, a kinematic model is established for motion prediction, and a sampling-based optimal parameter search is executed for automatic design. The proposed design method and kinematic models provide a tool for the generation of an optimal channel curve, with respect to target functions and required motion trajectories. Quantitative characterizations on the analytical model are conducted. To validate the functionalities, we generate three types of actuators to cover a wide range of motions in manipulation and locomotion tasks. Comparisons of model prediction on motion trajectory and prototype performance indicate the efficacy of the forward kinematics, and two task-based optimal designs for manipulation scenarios validate the effectiveness of the design parameter search. Prototyped by additive manufacturing technique with soft matter, multifunctional robots in case studies have been demonstrated, suggesting adaptability of the structure and convenience of the soft actuator's automatic design in both manipulation and locomotion. Results show that the novel design method together with the kinematic model paves a way for designing function-oriented actuators in an automatic flow.

As telecommunications technology progresses, telehealth frameworks are becoming more widely adopted in the context of long-term care (LTC) for older adults, both in care facilities and in homes. Today, robots could assist healthcare workers when they provide care to elderly patients, who constitute a particularly vulnerable population during the COVID-19 pandemic. Previous work on user-centered design of assistive technologies in LTC facilities for seniors has identified positive impacts. The need to deal with the effects of the COVID-19 pandemic emphasizes the benefits of this approach, but also highlights some new challenges for which robots could be interesting solutions to be deployed in LTC facilities. This requires customization of telecommunication and audio/video/data processing to address specific clinical requirements and needs. This paper presents OpenTera, an open source telehealth framework, aiming to facilitate prototyping of such solutions by software and robotic designers. Designed as a microservice-oriented platform, OpenTera is an end-to-end solution that employs a series of independent modules for tasks such as data and session management, telehealth, daily assistive tasks/actions, together with smart devices and environments, all connected through the framework. After explaining the framework, we illustrate how OpenTera can be used to implement robotic solutions for different applications identified in LTC facilities and homes, and we describe how we plan to validate them through field trials.
(© The Author(s) under exclusive licence to International Union for Physical and Engineering Sciences in Medicine (IUPESM) 2022.)

Cell-Free System metabolism, Metabolic Networks and Pathways, Protein Biosynthesis, Biosynthetic Pathways, and Metabolic Engineering methods

Biological systems provide a sustainable and complimentary approach to synthesizing useful chemical products. Metabolic engineers seeking to establish economically viable biosynthesis platforms strive to increase product titers, rates, and yields. Despite continued advances in genetic tools and metabolic engineering techniques, cellular workflows remain limited in throughput. It may take months to test dozens of unique pathway designs even in a robust model organism, such as Escherichia coli. In contrast, cell-free protein synthesis enables the rapid generation of enzyme libraries that can be combined to reconstitute metabolic pathways in vitro for biochemical synthesis in days rather than weeks. Cell-free reactions thereby enable comparison of hundreds to thousands of unique combinations of enzyme homologs and concentrations, which can quickly identify the most productive pathway variants to test in vivo or further characterize in vitro. This cell-free pathway prototyping strategy provides a complementary approach to accelerate cellular metabolic engineering efforts toward highly productive strains for metabolite production.
(© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Implant dentures -- Methods, Implant dentures -- Usage, Rapid prototyping -- Methods, and Rapid prototyping -- Usage

To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1002/rcs.1895/abstract Byline: Mohamed Farid Shehab, Nabila Mohammed Abdel Hamid, Nevien Abdullatif Askar, Ahmed Mokhtar Elmardenly Keywords: CAD-CAM, electron beam melting; immediate mandibular reconstruction; patient-specific titanium mesh; rapid prototyping Abstract Background Immediate mandibular reconstruction was performed using a patient-specific titanium mesh tray fabricated by electron beam melting (EBM) /rapid prototyping techniques. Methods Patient-specific titanium trays were virtually designed and fabricated using EBM technology/rapid prototyping for patients requiring mandibular resection and immediate reconstruction using an iliac crest bone graft. Dental implants were placed in the grafted sites and the patients received prosthetic rehabilitation with a follow-up of one year. Clinical data, postoperative bone formation and complications were evaluated. Results A symmetric appearance of facial contours was achieved. The titanium tray incorporated the particulate iliac crest bone graft that provided significant bone formation (mean 18.97 [+ or -] 1.45 mm) and predictable results. Stability of the dental implants was achieved. Conclusion The patient-specific titanium meshes and immediate particulate autogenous bone graft showed satisfactory clinical and surgical results in improving patients' quality of life and decreasing the overall treatment time with adequate functional rehabilitation.

The strategy of embedding conductive materials on polymeric matrices has produced functional and wearable artificial electronic skin prototypes capable of transduction signals, such as pressure, force, humidity, or temperature. However, these prototypes are expensive and cover small areas. This study proposes a more affordable manufacturing strategy for manufacturing conductive layers with 6 × 6 matrix micropatterns of RTV-2 silicone rubber and Single-Walled Carbon Nanotubes (SWCNT). A novel mold with two cavities and two different micropatterns was designed and tested as a proof-of-concept using Low-Force Stereolithography-based additive manufacturing (AM). The effect SWCNT concentrations (3 wt.%, 4 wt.%, and 5 wt.%) on the mechanical properties were characterized by quasi-static axial deformation tests, which allowed them to stretch up to ~160%. The elastomeric soft material's hysteresis energy (Mullin's effect) was fitted using the Ogden-Roxburgh model and the Nelder-Mead algorithm. The assessment showed that the resulting multilayer material exhibits high flexibility and high conductivity (surface resistivity ~7.97 × 10 4 Ω/sq) and that robust soft tooling can be used for other devices.

Industry, Lakes, and Software

Seaports are genuine, intermodal hubs connecting seaways to inland transport links, such as roads and railways. Seaports are located at the focal point of institutional, industrial, and control activities in a jungle of interconnected information systems. System integration is setting considerable challenges when a group of independent providers are asked to implement complementary software functionalities. For this reason, seaports are the ideal playground where software is highly composite and tailored to a large variety of final users (from the so-called port communities). Although the target would be that of shaping the Port Authorities to be providers of (digital) innovation services, the state-of-the-art is still that of considering them as final users, or proxies of them. For this reason, we show how a canonical cloud, virtualizing a distributed architecture, can be structured to host different, possibly overlapped, tenants, slicing the information system at the infrastructure, platform, and software layers. Resources at the infrastructure and platform layers are shared so that a variety of independent applications can make use of the local calculus and access the data stored in a Data Lake. Such a cloud is adopted by the Port of Livorno as a rapid prototyping framework for the development and deployment of ICT innovation services. In order to demonstrate the versatility of this framework, three case studies relating to as many prototype ICT services (Navigation Safety, e-Freight, and Logistics) released within three industrial tenants are here presented and discussed.

Organ-on-a-chip (OoC) and microfluidic devices are conventionally produced using microfabrication procedures that require cleanrooms, silicon wafers, and photomasks. The prototyping stage often requires multiple iterations of design steps. A simplified prototyping process could therefore offer major advantages. Here, we describe a rapid and cleanroom-free microfabrication method using maskless photolithography. The approach utilizes a commercial digital micromirror device (DMD)-based setup using 375 nm UV light for backside exposure of an epoxy-based negative photoresist (SU-8) on glass coverslips. We show that microstructures of various geometries and dimensions, microgrooves, and microchannels of different heights can be fabricated. New SU-8 molds and soft lithography-based polydimethylsiloxane (PDMS) chips can thus be produced within hours. We further show that backside UV exposure and grayscale photolithography allow structures of different heights or structures with height gradients to be developed using a single-step fabrication process. Using this approach: (1) digital photomasks can be designed, projected, and quickly adjusted if needed; and (2) SU-8 molds can be fabricated without cleanroom availability, which in turn (3) reduces microfabrication time and costs and (4) expedites prototyping of new OoC devices.

Aged, Communication, Humans, Motivation, Quality of Life, Aphasia, and Mobile Applications

Aphasia is a partial or total loss of the ability to articulate ideas or comprehend spoken language, resulting from brain damage, in a person whose language skills were previously normal. Our goal was to find out how a storytelling app can help people with aphasia to communicate and share daily experiences. For this purpose, the Aphasia Create app was created for tablets, along with Aphastory for the Google Glass device. These applications facilitate social participation and enhance quality of life by using visual storytelling forms composed of photos, drawings, icons, etc., that can be saved and shared. We performed usability tests (supervised by a neuropsychologist) on six participants with aphasia who were able to communicate. Our work contributes (1) evidence that the functions implemented in the Aphasia Create tablet app suit the needs of target users, but older people are often not familiar with tactile devices, (2) reports that the Google Glass device may be problematic for persons with right-hand paresis, and (3) a characterization of the design guidelines for apps for aphasics. Both applications can be used to work with people with aphasia, and can be further developed. Aphasic centers, in which the apps were presented, expressed interest in using them to work with patients. The Aphasia Create app won the Enactus Poland National Competition in 2015.

Many New Zealand residential dwellings suffer from dampness and fungi during the winter, which can cause respiratory health problems. This can be due to poor insulation and ventilation, and the situation worsens when residents cannot afford to heat the dwelling. The main aim of this paper is to modify an existing dehumidifier so that it can remove moisture, heat the living space and reduce fungi growth and bacteria. To achieve that, we installed ultraviolet germicidal lights (UVGI) in an existing dehumidifier with a total cost of USD $150.7 (NZD $213.76). The UVGI lights are known to be efficient in destroying the DNA of fungi and bacteria. The results show that the device reduced the fungi growth and did increase the room temperature because the dehumidifier captured two litres of water over 24 h of testing. The proposed device did achieve a reduction in particulate matters, from 0.9μg/m3to 0.14μg/m3and an acceptable range of relative humidity below 50%, which reduces the favourable conditions for fungi growth. Therefore, our proposed low-cost device does improve the indoor air quality (IAQ) in the living space.
(© 2021 The Author(s).)

Cell Culture Techniques, Humans, Reproducibility of Results, Xylenes, Lab-On-A-Chip Devices, and Polymers

Fabrication of microfluidic devices by photolithography generally requires specialized training and access to a cleanroom. As an alternative, 3D printing enables cost-effective fabrication of microdevices with complex features that would be suitable for many biomedical applications. However, commonly used resins are cytotoxic and unsuitable for devices involving cells. Furthermore, 3D prints are generally refractory to elastomer polymerization such that they cannot be used as master molds for fabricating devices from polymers ( e.g. polydimethylsiloxane, or PDMS). Different post-print treatment strategies, such as heat curing, ultraviolet light exposure, and coating with silanes, have been explored to overcome these obstacles, but none have proven universally effective. Here, we show that deposition of a thin layer of parylene, a polymer commonly used for medical device applications, renders 3D prints biocompatible and allows them to be used as master molds for elastomeric device fabrication. When placed in culture dishes containing human neurons, regardless of resin type, uncoated 3D prints leached toxic material to yield complete cell death within 48 hours, whereas cells exhibited uniform viability and healthy morphology out to 21 days if the prints were coated with parylene. Diverse PDMS devices of different shapes and sizes were easily cast from parylene-coated 3D printed molds without any visible defects. As a proof-of-concept, we rapid prototyped and tested different types of PDMS devices, including triple chamber perfusion chips, droplet generators, and microwells. Overall, we suggest that the simplicity and reproducibility of this technique will make it attractive for fabricating traditional microdevices and rapid prototyping new designs. In particular, by minimizing user intervention on the fabrication and post-print treatment steps, our strategy could help make microfluidics more accessible to the biomedical research community.

Chromatography, Liquid, Drug Liberation, Humans, Printing, Three-Dimensional, Tandem Mass Spectrometry, and Technology, Pharmaceutical

Analytical sample preparation techniques are regarded as crucial steps for analyzing compounds from different biological matrices. The development of new extraction techniques is a modern trend in the bioanalytical sciences. 3D printed techniques have emerged as a valuable technology for prototyping devices in customized shapes for a cost-effective way to advance analytical sample preparation techniques. The present study aims to fabricate customized filaments through the hot-melt extrusion (HME) technique followed by fused deposition modeling mediated 3D printing process for rapid prototyping of 3D printed sorbents to extract a sample from human plasma. Thus, we fabricated our own indigenous filament using poly (vinyl alcohol), Eudragit® RSPO, and tri-ethyl citrate through HME to prototype the fabricated filament into a 3D printed sorbent for the extraction of small molecules. The 3D sorbent was applied to extract hydrocortisone from human plasma and analyzed using a validated LC-MS/MS method. The extraction procedure was optimized, and the parameters influencing the sorbent extraction were systematically investigated. The extraction recovery of hydrocortisone was found to be >82% at low, medium, and high quality control samples, with a relative standard deviation of <2%. The intra-and inter-day precisions for hydrocortisone ranged from 1.0% to 12% and 2.0%-10.0%, respectively, whereas the intra-and inter-day accuracy for hydrocortisone ranged from 93.0% to 111.0% and 92.0% to 110.0%, respectively. The newly customizable size and shape of the 3D printed sorbent opens new possibilities for extracting small molecules from human plasma.
(Copyright © 2021 Elsevier B.V. All rights reserved.)

Cadaver, Cervical Vertebrae diagnostic imaging, Cervical Vertebrae surgery, Humans, Pedicle Screws, Spinal Fusion, and Surgery, Computer-Assisted

Purpose: Due to the high perforation rate of cervical pedicle screw placement, we have designed four different types of rapid prototyping navigation templates to enhance the accuracy of cervical pedicle screw placement.
Methods: Fifteen human cadaveric cervical spines from C2 to C7 were randomly divided into five groups, with three specimens in each group. The diameter of pedicle screw used in this study was 3.5 mm. Groups 1-4 were assisted by the two-level template, one-level bilateral template, one-level unilateral template and one-level point-contact template, respectively. Group 5 was without any navigation template. After the surgery, the accuracy of screw placement in the five groups was evaluated using postoperative computed tomographic scans to observe whether the screw breached the pedicle cortex.
Results: A total of 180 pedicle screws were inserted without any accidents. The accuracy rate was 75%, 100%, 100%, 91.7%, and 63.9%, respectively, from Groups 1 to 5. All the template groups were significantly higher than Group 5, though the two-level navigation template group was significantly lower than the other three template groups. The operation time was 4.72 ± 0.28, 4.81 ± 0.29, 5.03 ± 0.35, 8.42 ± 0.36, and 10.05 ± 0.52 min, respectively, from Groups 1 to 5. The no template and point-contact procedures were significantly more time-consuming than the template procedures.
Conclusion: This study demonstrated that four different design types of navigation templates achieved a higher accuracy in assisting cervical pedicle screw placement than no template insertion. However, the two-level template's accuracy was the lowest compared to the other three templates. Meanwhile, these templates avoided fluoroscopy during the surgery and decreased the operation time. It is always very challenging to translate cadaveric studies to clinical practice. Hence, the one-level bilateral, unilateral, and point-contact navigation templates designed by us need to be meticulously tested to verify their accuracy and safety.

The paper presents an original method concerning the problem of vibration reduction in the general case while milling large-size and geometrically complex details with the use of an innovative approach to the selection of spindle speed. A computational model is obtained by applying the so-called operational approach to identify the parameters of the workpiece modal model. Thanks to the experimental modal analysis results, modal subsystem identification was performed and reliable process data for simulation studies were obtained. Next, simulations of the milling process, for successive values of the spindle speed, are repeated until the best vibration state of the workpiece is obtained. For this purpose, the root mean square values of the time plots of vibration displacements are examined. The effectiveness of the approach proposed for reducing vibrations in the process of face milling is verified on the basis of the results of appropriate experimental investigations. The economic profitability of the implementation of the operational technique in the production practice of enterprises dealing with mechanical processing is demonstrated as well.

Elasticity, Hardness, Materials Testing, Surface Properties, Composite Resins, and Flexural Strength

Objective: This study is focused on testing experimental rapid prototyping materials for occlusal splints made from Urethandimethacrylate (UDMA) and Urethanmethacrylate (UMA).
Methods: Materials were mixed from UDMA and UMA in ratios of 1.0:0.0, 0.75:0.25, 0.5:0.5, 0.25:0.75 and 0.0:1.0. Specimens were printed using digital light processing (DLP). After post-processing, the specimens underwent testing on flexural strength, modulus of elasticity, hardness, wear behavior, surface roughness, gloss and color stability. All tests were performed after 24 h (baseline) and 10 days of water storage (aging). Splints underwent cyclic pull-off and insertion testing, which was alongside simulated using finite element analysis.
Results: The mechanical properties were significantly influenced by changes in the UDMA:UMA ratio. Statistical analysis revealed that increased amounts of UMA correlated with a decrease in flexural strength (92.0 to 30.7 MPa), modulus of elasticity (2.4 to 0.6 GPa), hardness (155.1 to 102.0 N/mm 2 ) and wear resistance (-1394.9 to -1742.1 μm). Materials with higher amounts of UMA were also more likely to be influenced by water storage. Specimens with 75% and 100% UMA content were partly not analyzable due to soft consistency. Optical properties showed only minor influence from UMA content and aging. Differences in surface roughness (3.9 to 2.4 μm) and color stability were insignificant. Gloss was partly influenced by the UDMA:UMA ratio and water storage. Mean survival rates for cyclic pull-off and insertion testing ranged from 2537 to 23,857 cycles. A correlation between the amount of UMA and survival rates was observed.
Significance: The addition of up to 25% UMA showed promising results, complying with clinical standards and delivering acceptable results in the cyclic pull-off and insertion test. Further investigation on increments between 0 and 25% UMA could help to find an optimum.
(Copyright © 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)