163 results on '"scanning"'
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2. Development and preliminary evaluation of a grid design application for adults and children using scanning and bci-based augmentative and alternative communication.
- Author
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Pitt KM
- Abstract
Augmentative and alternative communication (AAC) supports offer communication aids for individuals with severe speech and physical impairments. This study presents the development and proof of concept for an iPad application designed to evaluate the design preferences of both adults and children for AAC scanning and emerging P300-brain-computer interface access to AAC (BCI-AAC), both of which utilize item highlighting. Developed through a multidisciplinary and iterative process, the application incorporates customizable highlighting methods and display options for spelling-based and pictorial symbol interfaces. Initial testing involved five participants, including two adults with physical impairments and three children without physical impairments. Participants created unique interface displays using picture overlays, motion, and other highlighting methods. Feedback indicated strong usability and enjoyment during application use. Recommendations included expanded sound options and pre-made templates. This study demonstrates preliminary proof of concept for the application and supports the need for further research to explore user preferences and optimize communication outcomes across various AAC modalities. While BCI-AAC technology remains in its early stages, its integration into this application helps promote user-centered BCI-AAC development.
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- 2024
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3. Visual mental imagery abilities in autism.
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Bled C, Guillon Q, Mottron L, Soulieres I, and Bouvet L
- Subjects
- Humans, Male, Female, Adult, Young Adult, Reaction Time physiology, Adolescent, Neuropsychological Tests statistics & numerical data, Pattern Recognition, Visual physiology, Imagination physiology, Autistic Disorder physiopathology, Autistic Disorder psychology, Visual Perception physiology
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- 2024
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4. The influence of different cement spaces on the marginal gap of lithium disilicate crowns constructed by two scanner and milling unit combinations.
- Author
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Dudley J and Xu J
- Subjects
- Humans, Dental Cements, Molar, Crowns, Dental Porcelain chemistry, Computer-Aided Design, Dental Prosthesis Design, Dental Marginal Adaptation
- Abstract
Background: This study compared the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using a contemporary and older scanner/milling unit combination at three different cement spaces., Methods: Twenty-four undergraduate students prepared a Columbia model lower left first molar for an LDS crown in a simulated environment. From each crown preparation, one LDS crown was constructed using an E4D scanner/E4D milling unit (E4DS/E4DM) and TRIOS 3 scanner/Sirona inLab MC X5 milling unit (TRIO/MCX5) at cement space settings of 50, 100 and 200 μm. Each LDS crown was positioned onto the original crown preparation, and then a stereomicroscope was used to make three vertical marginal gap measurements at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal). The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface., Results: The MMGs of CAD/CAM LDS crowns constructed by TRIO/MCX5 were 72.31 at 50, 63.73 at 100 μm and 46.23 μm at 200 μm, which were smaller than E4DS/E4DM at each cement space., Conclusions: Increasing the cement space decreased the MMG in both scanner/milling unit combinations. The smallest MMG was found using the newer scanner/milling unit at the 200 μm cement space. © 2024 Australian Dental Association., (© 2024 The Authors. Australian Dental Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Dental Association.)
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- 2024
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5. Promoting Exploration During Learning: Effect of Imposed and Self-Controlled Practice Schedules on Learners' Behavioral Flexibility.
- Author
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Hacques G, Komar J, and Seifert L
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- Humans, Male, Female, Young Adult, Motor Skills physiology, Adult, Exploratory Behavior physiology, Physical Education and Training methods, Learning, Practice, Psychological
- Abstract
Purpose: Enriching learners' motor repertoires in a complex pluri-articular task, such as climbing, could help learners' adaptation to various sets of task constraints. Promoting exploration with variable practice conditions is one solution recurrently proposed. However, recent studies have shown that a too elevated exploration-exploitation ratio during practice could impair learning. A proposed solution is to give learners some control over their practice schedule, which appeared to better respect the individual learning dynamic in comparison to the usual experimenter-imposed practice schedule. Thus, the aim of this study is to investigate whether giving learners the possibility of controlling when to confront to new climbing routes would result in greater flexibility in their motor repertoire compared to giving them an imposed schedule of climbing routes or a constant practice condition. Method: Participants were assigned to either a constant practice group (CPG), an imposed-variability group (IVG) or a self-controlled variability group (SVG) to carry out a climbing task. To assess participants' behavioral flexibility, a scanning procedure was conceived by manipulating the route design and the instructions. Results: Participants showed an initial lack of flexibility as they strongly relied on a single coordination pattern. At posttest and retention, the three groups more frequently used a new hand coordination pattern and more often showed coordination patterns associated with high climbing fluency. Results suggest that the individualized rate of exploration in the self-controlled practice condition may have helped the learners improve their flexibility, whereas forcing exploration did not seem more beneficial than constant practice in this complex pluri-articular task.
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- 2024
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6. A Computed Tomography-Based Fracture Prediction Model With Images of Vertebral Bones and Muscles by Employing Deep Learning: Development and Validation Study.
- Author
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Kong SH, Cho W, Park SB, Choo J, Kim JH, Kim SW, and Shin CS
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- Humans, Female, Male, Aged, Retrospective Studies, Middle Aged, Longitudinal Studies, Spine diagnostic imaging, Muscle, Skeletal diagnostic imaging, Muscle, Skeletal injuries, Deep Learning, Tomography, X-Ray Computed methods, Spinal Fractures diagnostic imaging
- Abstract
Background: With the progressive increase in aging populations, the use of opportunistic computed tomography (CT) scanning is increasing, which could be a valuable method for acquiring information on both muscles and bones of aging populations., Objective: The aim of this study was to develop and externally validate opportunistic CT-based fracture prediction models by using images of vertebral bones and paravertebral muscles., Methods: The models were developed based on a retrospective longitudinal cohort study of 1214 patients with abdominal CT images between 2010 and 2019. The models were externally validated in 495 patients. The primary outcome of this study was defined as the predictive accuracy for identifying vertebral fracture events within a 5-year follow-up. The image models were developed using an attention convolutional neural network-recurrent neural network model from images of the vertebral bone and paravertebral muscles., Results: The mean ages of the patients in the development and validation sets were 73 years and 68 years, and 69.1% (839/1214) and 78.8% (390/495) of them were females, respectively. The areas under the receiver operator curve (AUROCs) for predicting vertebral fractures were superior in images of the vertebral bone and paravertebral muscles than those in the bone-only images in the external validation cohort (0.827, 95% CI 0.821-0.833 vs 0.815, 95% CI 0.806-0.824, respectively; P<.001). The AUROCs of these image models were higher than those of the fracture risk assessment models (0.810 for major osteoporotic risk, 0.780 for hip fracture risk). For the clinical model using age, sex, BMI, use of steroids, smoking, possible secondary osteoporosis, type 2 diabetes mellitus, HIV, hepatitis C, and renal failure, the AUROC value in the external validation cohort was 0.749 (95% CI 0.736-0.762), which was lower than that of the image model using vertebral bones and muscles (P<.001)., Conclusions: The model using the images of the vertebral bone and paravertebral muscle showed better performance than that using the images of the bone-only or clinical variables. Opportunistic CT screening may contribute to identifying patients with a high fracture risk in the future., (©Sung Hye Kong, Wonwoo Cho, Sung Bae Park, Jaegul Choo, Jung Hee Kim, Sang Wan Kim, Chan Soo Shin. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 12.07.2024.)
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- 2024
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7. A systematic review on visual scanning behaviour in hemianopia considering task specificity, performance improvement, spontaneous and training-induced adaptations.
- Author
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Postuma EMJL, Heutink J, Tol S, Jansen JL, Koopman J, Cornelissen FW, and de Haan GA
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- Humans, Adaptation, Physiological, Task Performance and Analysis, Reading, Hemianopsia rehabilitation, Hemianopsia physiopathology
- Abstract
Purpose: People with homonymous hemianopia (HH) benefit from applying compensatory scanning behaviour that limits the consequences of HH in a specific task. The aim of the study is to (i) review the current literature on task-specific scanning behaviour that improves performance and (ii) identify differences between this performance-enhancing scanning behaviour and scanning behaviour that is spontaneously adopted or acquired through training., Materials and Methods: The databases PsycInfo, Medline, and Web of Science were searched for articles on scanning behaviour in people with HH., Results: The final sample contained 60 articles, reporting on three main tasks, i.e., search ( N = 17), reading ( N = 16) and mobility ( N = 14), and other tasks ( N = 18). Five articles reported on two different tasks. Specific scanning behaviour related to task performance in search, reading, and mobility tasks. In search and reading tasks, spontaneous adaptations differed from this performance-enhancing scanning behaviour. Training could induce adaptations in scanning behaviour, enhancing performance in these two tasks. For mobility tasks, limited to no information was found on spontaneous and training-induced adaptations to scanning behaviour., Conclusions: Performance-enhancing scanning behaviour is mainly task-specific. Spontaneous development of such scanning behaviour is rare. Luckily, current compensatory scanning training programs can induce such scanning behaviour, which confirms that providing scanning training is important.IMPLICATIONS FOR REHABILITATIONScanning behaviour that improves performance in people with homonymous hemianopia (HH) is task-specific.Most people with HH do not spontaneously adopt scanning behaviour that improves performance.Compensatory scanning training can induce performance-enhancing scanning behaviour.
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- 2024
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8. Material Testing of Historic Bricks and Mortars in Degraded Masonry Structures.
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Bajno D, Schabowicz K, and Grzybowska A
- Abstract
The subject of this article is material research carried out on the ruins of a medieval castle located in west-central Poland. This facility was built at the beginning of the 15th century by the Order of St. John, and during its long life, it was subjected to many reconstructions. Unfortunately, in 1975, it was destroyed by fire. Since then, it has been left in a state of advanced ruin, exposed to climatic influences without any protection. The subject of the research was to assess the possibility of maintaining such buildings in a severely degraded condition while ensuring their technical efficiency. The article discusses a particular instance of "consolidation" applied to a structure in a state of historical, architectural, and structural ruin. After the diagnosis, it was determined that the structure should be safeguarded using a minimally invasive method. The purpose of these activities was to answer the question of whether the structure could be left to continue operating despite failing to meet the requirements of current standards and regulations while posing an additional danger to itself and the environment,. This goal was achieved by obtaining a considerable amount of data on the condition of the materials embedded in the masonry structure, thanks to which the initial parameters for conducting an assessment of the technical condition of the damaged masonry structure and evaluating the degree of its danger were developed. The results of the research and analysis carried out and described in this article can be used in other similar situations where saving national heritage objects through "artificial modern" strengthening will be unsafe and will lead to a loss of their authenticity. We still have a long way to go to develop a comprehensive method for "in situ" diagnosis of heterogeneous masonry structures, so we should use possible techniques and knowledge to conduct such assessments and propose rescue methods for historically valuable objects in a way that could minimize the damage and that can "easily" disappear from our surroundings. Each study should have a specific purpose, not only research but also a long-term perspective, making it possible to leave material for further research and analysis, including testing new research methods in real conditions of its installation.
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- 2024
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9. DNA melting analysis.
- Author
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Wittwer CT, Hemmert AC, Kent JO, and Rejali NA
- Subjects
- Humans, Polymerase Chain Reaction methods, Nucleic Acid Denaturation, DNA genetics, DNA chemistry
- Abstract
Melting is a fundamental property of DNA that can be monitored by absorbance or fluorescence. PCR conveniently produces enough DNA to be directly monitored on real-time instruments with fluorescently labeled probes or dyes. Dyes monitor the entire PCR product, while probes focus on a specific locus within the amplicon. Advances in amplicon melting include high resolution instruments, saturating DNA dyes that better reveal multiple products, prediction programs for domain melting, barcode taxonomic identification, high speed microfluidic melting, and highly parallel digital melting. Most single base variants and small insertions or deletions can be genotyped by high resolution amplicon melting. High resolution melting also enables heterozygote scanning for any variant within a PCR product. A web application (uMelt, http://www.dna-utah.org) predicts amplicon melting curves with multiple domains, a useful tool for verifying intended products. Additional applications include methylation assessment, copy number determination and verification of sequence identity. When amplicon melting does not provide sufficient detail, unlabeled probes or snapback primers can be used instead of covalently labeled probes. DNA melting is a simple, inexpensive, and powerful tool with many research applications that is beginning to make its mark in clinical diagnostics., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
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- 2024
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10. [Application of Digital Galvanometer Scanner System for CO 2 Fractional Laser Safety Improvement].
- Author
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Li M, Feng W, and Liu S
- Subjects
- Equipment Design, Equipment Safety, Lasers, Gas
- Abstract
An analog PID controller-based galvanometer scanner is widely used by fractional laser medical equipment (FLME) to scan lasers across tissue surfaces, achieving the desired therapeutic effect. This type of driver, primarily composed of passive components and operational amplifiers, can only accept commands from the central controller of the FLME, with a simple hardware circuit-based fault diagnosis; thus, the safety of the FLME is compromised. To address these issues, the failure mechanisms of galvanometers and their impact on the safety of FLME are thoroughly analyzed first. Then, an adaptive limit protection method, a coil open circuit fault diagnosis, a communication timeout protection based on two handshakes, and a galvanometer control timeout protection are proposed, respectively, based on a digital driver platform, to supplement the deficiencies in the original fault diagnosis and protection system. This ensures the safety of the FLME. Finally, the effectiveness of the proposed strategies is validated through experiments.
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- 2024
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11. Development of a Six-Degree-of-Freedom Analog 3D Tactile Probe Based on Non-Contact 2D Sensors.
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Albajez JA, Velázquez J, Torralba M, Díaz-Pérez LC, Yagüe-Fabra JA, and Aguilar JJ
- Abstract
In this paper, a six-degree-of-freedom analog tactile probe with a new, simple, and robust mechanical design is presented. Its design is based on the use of one elastomeric ring that supports the stylus carrier and allows its movement inside a cubic measuring range of ±3 mm. The position of the probe tip is determined by three low-cost, noncontact, 2D PSD (position-sensitive detector) sensors, facilitating a wider application of this probe to different measuring systems compared to commercial ones. However, several software corrections, regarding the size and orientation of the three LED light beams, must be carried out when using these 2D sensors for this application due to the lack of additional focusing or collimating lenses and the very wide measuring range. The development process, simulation results, correction models, experimental tests, and calibration of this probe are presented. The results demonstrate high repeatability along the X-, Y-, and Z-axes (2.0 µm, 2.0 µm, and 2.1 µm, respectively) and overall accuracies of 6.7 µm, 7.0 µm, and 8.0 µm, respectively, which could be minimized by more complex correction models.
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- 2024
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12. Impact of Breathing Control Training Program on sonographic quantification of abdominal vasculature.
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Hassan MG, Alotaibi AM, Altuwaym RH, Alnuwaysir RH, Alharbi RB, Alnajashi LM, Alsaber MK, Aldakan HF, Hawesa HM, Abdelgabar ZA, Aldahes AS, and Yaqob MG
- Subjects
- Humans, Male, Female, Adult, Abdomen diagnostic imaging, Abdomen blood supply, Mesenteric Artery, Superior diagnostic imaging, Young Adult, Breathing Exercises methods, Blood Flow Velocity, Saudi Arabia, Respiration, Ultrasonography methods, Aorta, Abdominal diagnostic imaging, Vena Cava, Inferior diagnostic imaging, Renal Artery diagnostic imaging
- Abstract
Objectives: To compare vascular scanning parameters (vessel diameter, peak systolic velocity, end-diastolic velocity, and resistive index) and scanning time before and after breathing control training program for selected abdominal vessels., Methods: This study was pre and post quasi-experimental. The researchers designed a breathing training program that gives participants instructions through a video describing breathing maneuvers. Data were collected at the ultrasound laboratory/College of Health and Rehabilitation Sciences in Princess Nourah bint Abdul Rahman University, Riyadh, Saudi Arabia from January 2023 to November 2023. About 49 volunteers at the university participated in the study. Scanning was performed two times for the right renal artery, upper abdominal aorta, inferior vena cava, and superior mesenteric artery. Scanning time was measured before and after the program as well. A paired sample t-test was used to compare the parameters means and time before and after the program., Results: The program had a significant effect on the following parameters: right renal artery peak systolic velocity ( p =0.042), upper abdominal aortic peak systolic velocity, and resistive index ( p =0.014, p =0.014 respectively), superior mesenteric artery and inferior vena cava diameters ( p =0.010 and p =0.020). The scanning time was reduced significantly ( p <0.001)., Conclusion: The breathing training program saves time and improves ultrasound measurement quality. Hospitals and health centers should consider the importance of breathing control training programs before abdominal scanning., (Copyright: © Saudi Medical Journal.)
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- 2024
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13. No evidence that visual exploratory activity distinguishes the super elite from elite football players.
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Caso S, McGuckian TB, and van der Kamp J
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Visual exploratory activities (VEA) refer to head and body movements that football players make prior to receiving the ball to search possibilities for action. VEA is considered a key performance indicator that differentiates the skill level of players. This study revisited whether VEA also distinguishes super elite, award winning players from their elite teammates without awards. To this end, video footage from the men's UEFA Champions League season 2018-2019 featuring the super elite players ( n = 18) and the elite players ( n = 18) was analyzed. To reduce the potential differences in match dynamics as much as possible, the selected players in the two groups were of the same team, playing the same match, in the same positioning line. VEA (i.e. frequency per unit time) during the penultimate and final pass prior to ball reception and performance (i.e. percentages of adequate ball contacts and subsequent actions) were compared between the two groups of players using ANOVA and Mann-Whitney tests, respectively. In addition, hierarchical stepwise regression analyses were conducted to explore the degree to which VEA was predicted by group and subsequent performance. The results showed that the players had higher VEA during the final pass ( M = 0.45) than the penultimate pass ( M = 0.41). There were no significant differences in VEA or performance between the two groups. Also, the regression analyses did not deliver significant models. We conclude that with partial control for match dynamics, no evidence emerged to support that VEA distinguishes super elite players from elite football players.
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- 2024
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14. Customized scan bodies to facilitate intraoral scanning for full arch implant prosthesis: A dental technique.
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Saaedi TMASE and Thabet YG
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- Computer-Aided Design, Dental Prosthesis, Implant-Supported, Dental Impression Technique, Dental Implants
- Abstract
This article presents the design of customized resin scan bodies with different forms and their use to facilitate intraoral scanning of a maxillary full arch implant case with five implants. The aim is to limit the distance between the scan bodies and to create definite landmarks to facilitate the scanning process in full arch implant cases., (© 2023 by the American College of Prosthodontists.)
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- 2024
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15. Noise-dependent bias in quantitative STEM-EMCD experiments revealed by bootstrapping.
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Ali H, Rusz J, Bürgler DE, Adam R, Schneider CM, Tai CW, and Thersleff T
- Abstract
Electron magnetic circular dichroism (EMCD) is a powerful technique for estimating element-specific magnetic moments of materials on nanoscale with the potential to reach atomic resolution in transmission electron microscopes. However, the fundamentally weak EMCD signal strength complicates quantification of magnetic moments, as this requires very high precision, especially in the denominator of the sum rules. Here, we employ a statistical resampling technique known as bootstrapping to an experimental EMCD dataset to produce an empirical estimate of the noise-dependent error distribution resulting from application of EMCD sum rules to bcc iron in a 3-beam orientation. We observe clear experimental evidence that noisy EMCD signals preferentially bias the estimation of magnetic moments, further supporting this with error distributions produced by Monte-Carlo simulations. Finally, we propose guidelines for the recognition and minimization of this bias in the estimation of magnetic moments., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)
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- 2024
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16. Using the Amsler Grid Test for Age-Related Macular Degeneration Screening.
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Kuzucu Üşümüş SA, Koçak Altıntaş AG, Özdemir A, and Aypak C
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- Humans, Middle Aged, Aged, Visual Acuity, Sensitivity and Specificity, Tomography, Optical Coherence, Visual Field Tests methods, Macular Degeneration diagnosis
- Abstract
Objectives: To evaluate the use of the Amsler grid test (AGT) in screening for age-related macular degeneration (AMD), one of the most common causes of blindness, in primary healthcare settings., Materials and Methods: The AGT was applied to 700 eyes of 355 people aged 50 and over who applied to a family health center in Ankara and had no eye complaints. The test was considered positive if the lines on the AGT card were seen as broken or curved, there was a difference in shape or size between the squares, or a color change or blurring was described in any area. An ophthalmologist was consulted if the AGT was positive in one or both eyes. Patients considered suitable by ophthalmologists were evaluated with optical coherence tomography. AGT results were compared with ophthalmologist examination and tomography findings in terms of AMD detection., Results: The AGT was positive in 97 (13.9%) and negative in 603 (86.1%) out of 700 eyes included in the study. A total of 184 eyes, 79 with a positive AGT and 105 eyes with a negative test, were evaluated by an ophthalmologist. As a result of examinations and tests performed by ophthalmologists, AMD was detected in a total of 67 eyes: 42 of 79 eyes with positive AGT and 25 of 105 eyes with negative AGT but referred to an ophthalmologist for different reasons. In our study, the AGT had 62.7% sensitivity and 68.4% specificity., Conclusion: The AGT is an inexpensive and easily applicable test. Although moderate sensitivity and specificity were found in our study; further studies are needed to evaluate the suitability of its use for AMD screening in primary care with limited facilities., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (©Copyright 2024 by the Turkish Ophthalmological Association / Turkish Journal of Ophthalmology published by Galenos Publishing House.)
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- 2024
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17. Deformation of palmar hand measurements in a power grip by wrist ulnar/radial deviation.
- Author
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Jung H, Lee W, Moon S, and You H
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- Male, Female, Humans, Ergonomics, Hand Strength, Fingers, Wrist, Hand
- Abstract
Objectives: The present study analyzed changes in palmar hand measurements during power grip by wrist radial/ulnar deviation for an ergonomic grip design., Method: Twelve palmar dimensions (Tip-to-PTC/DTC distances, Tip-to-MMC distances, and Tip-to-MMC surface lengths) of digits 2 to 5 were measured for 30 Koreans with various hand sizes (15 males and 15 females; hand length = 177.9 ± 12.3 mm) at three wrist postures (neutral, 20° of radial deviation, and 30° of ulnar deviation) using 3D scanning and casting methods., Results: As the hand changed from the straight neutral posture to the power grip posture, the Tip-to-PTC/DTC distances (related to grip widths), Tip-to-MMC distances (related to grip heights), and Tip-to-MMC surface lengths (related to grip circumferences) decreased to 30%-65% compared to corresponding original lengths. Wrist posture also had significant effects on the Tip-to-PTC/DTC and Tip-to-MMC distances by 6.5%-9.0%, while finger position significantly affected all the measurements by 8.2%-22.3%., Practitioner Summary: The measurement protocol of palmar hand dimensions and the changes in palmar hand measurements by wrist posture are of use to develop an ergonomic handle design for comfort and prevention of musculoskeletal disorders., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that colud have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)
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- 2024
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18. Transforming P & O Care with 3D Printing-More than Meets the Eye.
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Andrysek J and Ramdial S
- Abstract
Many within the prosthetics and orthotics (P&O) industry are embracing 3D printing technology to produce better devices more efficiently, cost-effectively and to improve patient outcomes. 3D printing is here to stay, but how much will it transform P&O practices? This paper explores the state-of 3D printing technology as it applies to P&O and aims to highlight important considerations for bringing 3D printing into mainstream practice. The paper draws from recent published literature, as well as experiences stemming from ongoing efforts focused on implementing digital workflows and 3D printing into P&O care. The paper examines the topic from the technological, research, economics, funding, and clinical perspectives. While 3D printing and digital workflows have advantages over traditional methods (i.e. ability to design more complex parts, reprinting and reproduction of parts, less labour intensive) there are also challenges limiting adoption. First, despite recent advancements in 3D printing technology, gaps still exist in terms of the materials and processes. For example, cost-effectively fabricating devices that are concurrently strong and durable, allow for colourful designs, and are thermoformable are still being developed. Cost-wise, 3D printing may currently be more viable for small, or paediatric devices. There are also limited technical standards to ensure safe and durable devices are produced, as well as a lack of evidence and information about patient outcomes and operating costs. Nevertheless, a great amount of enthusiasm and momentum exists within the industry to innovate, and with it the potential for 3D printing to one day be central to mainstream P&O care. Given the many aspects of the P&O industry, collaboration and partnerships will facilitate learning from each other to advance and realize the potential of 3D printing sooner., Competing Interests: The authors have no conflicts of interest to declare related to this paper., (Copyright (c) 2023 Andrysek J, Ramdial S.)
- Published
- 2023
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19. Leukocyte- and Platelet-Rich Fibrin (L-PRF) Obtained from Smokers and Nonsmokers Shows a Similar Uniaxial Tensile Response In Vitro.
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Lara C, Bezmalinovic A, García-Herrera C, Ríos S, Valenzuela LM, and Martínez CE
- Abstract
We evaluated and compared the biomechanical properties of Leukocyte-and Platelet Rich Fibrin L-PRF clots and membranes derived from smoker and nonsmoker donors. Twenty venous-blood donors (aged 18 to 50 years) were included after signing informed consent forms. L-PRF clots were analyzed and then compressed to obtain L-PRF membranes. L-PRF clot and membrane samples were tested in quasi-static uniaxial tension and the stress-stretch response was registered and characterized. Furthermore, scanning electron microscope representative images were taken to see the fibrin structure from both groups. The analysis of stress-stretch curves allowed us to evaluate the statistical significance in differences between smoker and nonsmoker groups. L-PRF membranes showed a stiffer response and higher tensile strength when compared to L-PRF clots. However, no statistically significant differences were found between samples from smokers and nonsmokers. With the limitations of our in vitro study, we can suggest that the tensile properties of L-PRF clots and membranes from the blood of smokers and nonsmokers are similar. More studies are necessary to fully characterize the effect of smoking on the biomechanical behavior of this platelet concentrate, to further encourage its use as an alternative to promote wound healing in smokers.
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- 2023
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20. Inking cell blocks improves scanner detection for diagnosis in pathology.
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Eloy C, Neves B, Vale J, Campelos S, Curado M, and Polónia A
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- Humans, Ink, Microscopy methods
- Abstract
Cell blocks may be hard to be totally automatically detected by the scanner (ADS), generating incomplete whole slide images (WSIs), with areas that are not scanned, leading to possible false negative diagnosis. The aim of this study is to test if inking the cell blocks helps increasing ADS. Test 1: 15 cell blocks were sectioned, one half inked black (1HB) and the other inked green (1HG). Each of the halves was individually processed to generate a WSI stained by the H&E. 1HBs and 1HGs had similar scanning time (median 59 s vs. 65 s, p = .126) and file sizes (median 382 Mb vs. 381 Mb, p = .567). The black ink interfered less in the observation (2.2% vs. 44.4%; p < .001) than in the green one. Test 2: 15 cell blocks were sectioned, one half inked black (2HB) and the other left unstained/null (2HN). Each of the halves was individually processed to generate three WSIs-one HE, one periodic-acid Schiff (PAS), and one immunostained by cytokeratin AE1&AE3 (CKAE1AE3). HE and PAS WSIs from both 2HN and 2HB groups were all totally ADS and had similar scanning times and file sizes. Concerning immunostaining with CKAE1AE3: ADS (46.7% vs. 93.3%; p = .014), median time for scanning (57 s vs. 83 s; p < .001) and file size (178 Mb vs. 338 Mb; p < .001) were reduced significantly in the 2HN group in comparison with the 2HB. Although increasing scanning time and file size, inking the cell blocks helps increasing ADS after immunostaining, improving the safety and efficiency of the digital pathology workflow., (© 2023 Wiley Periodicals LLC.)
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- 2023
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21. A dynamic parallel image acquisition method for slide scanning process.
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Zhong B, Liao Z, Hao X, Hu J, and Sun L
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Automated microscope systems have played an important role in the screening of numerous diseases. However, it is a very time-consuming process to continuously acquire images under the high magnification objective lens. This paper proposes a dynamic parallel image acquisition method, which can greatly improve image acquisition speed. Due to the relative motion between the x-y stage and the camera, some of the captured images have motion blur To this end, we also designed a motor variable speed motion curve to ensure the quality of the collected images. The experimental results show that the traditional image scanning mode needs 47.3 ms to obtain continuous microscopic images, while the dynamic parallel image acquisition method only needs 25.4 ms, which improves the acquisition speed without affecting the clarity of the acquired images., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: BoWen Zhong reports financial support was provided by National Natural Science Foundation of China (No. 52175541, 51875378)., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
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- 2023
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22. Numerical and physical modeling of breast cancer based on image fusion and artificial intelligence.
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Dołęga-Kozierowski B, Kasprzak P, Lis M, Szynglarewicz B, Matkowski R, Sawicki M, Dymek M, Szumiejko A, Carmo G, Kwiatkowski A, Soliński DG, and Ptak M
- Subjects
- Humans, Female, Artificial Intelligence, Breast pathology, Mastectomy, Segmental, Ultrasonography, Magnetic Resonance Imaging methods, Breast Neoplasms diagnostic imaging, Breast Neoplasms surgery, Breast Neoplasms pathology
- Abstract
Purpose: The key problem raised in the paper is the change in the position of the breast tumor due to magnetic resonance imaging examinations in the abdominal position relative to the supine position during the surgical procedure. Changing the position of the patient leads to significant deformation of the breast, which leads to the inability to indicate the location of the neoplastic lesion correctly., Methods: This study outlines a methodological process for treating cancer patients. Pre-qualification assessments are conducted for magnetic resonance imaging (MRI), and 3D scans are taken in three positions: supine with arms raised, supine surgical position (SS), and standing. MRI and standard ultrasonography (USG) imaging are performed, and breast and cancer tissue are segmented from the MRI images. Finite element analysis is used to simulate tissue behavior in different positions, and an artificial neural network is trained to predict tumor dislocation. Based on the model, a 3D-printed breast with a highlighted tumor is manufactured. This computer-aided analysis is used to create a detailed surgical plan, and lumpectomy surgery is performed in the SS. In addition, the geometry of the tumor is presented to the medical staff as a 3D-printed element., Results: By utilizing a comprehensive range of techniques, including pre-qualification assessment, 3D scanning, MRI and USG imaging, segmentation of breast and cancer tissue, model analysis, image fusion, finite element analysis, artificial neural network training, and additive manufacturing, a detailed surgical plan can be created for performing lumpectomy surgery in the supine surgical position., Conclusion: The new approach developed for the pre-operative assessment and surgical planning of breast cancer patients has demonstrated significant potential for improving the accuracy and efficacy of surgical procedures. This procedure may also help the pathomorphological justification. Moreover, transparent 3D-printed breast models can benefit breast cancer operation assistance. The physical and computational models can help surgeons visualize the breast and the tumor more accurately and detailedly, allowing them to plan the surgery with greater precision and accuracy., (© 2023. The Author(s).)
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- 2023
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23. Strategies for highlighting items within visual scene displays to support augmentative and alternative communication access for those with physical impairments.
- Author
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Pitt KM and McCarthy JW
- Subjects
- Humans, Fixation, Ocular, Communication, Brain-Computer Interfaces, Communication Devices for People with Disabilities, Mobile Applications, Communication Disorders
- Abstract
Purpose: In contrast to the traditional grid-based display, visual scene displays (VSDs) offer a new paradigm for aided communication. For individuals who cannot select items from an AAC display by direct selection due to physical impairments, AAC access can be supported via methods such as item scanning. Item scanning sequentially highlights items on a display until the individual signals for selection. How items are highlighted or scanned for AAC access can impact performance outcomes. Further, the effectiveness of a VSD interface may be enhanced through consultation with experts in visual communication. Therefore, to support AAC access for those with physical impairments, the aim of this study was to evaluate the perspectives of experts in visual communication regarding effective methods for highlighting VSD elements., Methods: Thirteen participants with expertise related to visual communication (e.g., photographers, artists) completed semi-structured interviews regarding techniques for item highlighting., Results: Study findings identified four main themes to inform how AAC items may be highlighted or scanned, including (1) use of contrast related to light and dark, (2) use of contrast as it relates to colour, (3) outline highlighting, and (4) use of scale and motion., Conclusion: By identifying how compositional techniques can be utilized to highlight VSD elements, study findings may inform current practice for scanning-based AAC access, along with other selection techniques where feedback or highlighting is used (e.g., eye-gaze, brain-computer interface). Further, avenues for just-in-time programming are discussed to support effective implementation for those with physical impairments.IMPLICATIONS FOR REHABILITATIONFindings identify multiple potential techniques to improve scanning through items in a photograph for individuals with severe motor impairments using alternative access strategies.Study findings inform current practice for scanning-based AAC access, along with other selection techniques where feedback or highlighting is used (e.g., eye-gaze, brain-computer interface).Avenues for just in time programming of AAC displays are discussed to decrease programming demands and support effective implementation of study findings.
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- 2023
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24. Crime Light Imaging (CLI): A Novel Sensor for Stand-Off Detection and Localization of Forensic Traces.
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Chiuri A, Chirico R, Angelini F, Andreoli F, Menicucci I, Nuvoli M, Cano-Trujillo C, Montalvo G, and Lazic V
- Abstract
Stand-off detection of latent traces avoids the scene alteration that might occur during close inspection by handheld forensic lights. Here, we describe a novel sensor, named Crime Light Imaging (CLI), designed to perform high-resolution photography of targets at a distance of 2-10 m and to visualize some common latent traces. CLI is based on four high-power illumination LEDs and one color CMOS camera with a motorized objective plus frontal filters; the LEDs and camera could be synchronized to obtain short-exposure images weakly dependent on the ambient light. The sensor is integrated into a motorized platform, providing the target scanning and necessary information for 3D scene reconstruction. The whole system is portable and equipped with a user-friendly interface. The preliminary tests of CLI on fingerprints at distance of 7 m showed an excellent image resolution and drastic contrast enhancement under green LED light. At the same distance, a small (1 µL) blood droplet on black tissue was captured by CLI under NIR LED, while a trace from 15 µL semen on white cotton became visible under UV LED illumination. These results represent the first demonstration of true stand-off photography of latent traces, thus opening the way for a completely new approach in crime scene forensic examination.
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- 2023
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25. Improving the Mechanical Properties of Orthodontic Occlusal Splints Using Nanoparticles: Silver and Zinc Oxide.
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Barbur I, Opris H, Colosi HA, Baciut M, Opris D, Cuc S, Petean I, Moldovan M, Dinu CM, and Baciut G
- Abstract
The goal of the current study was to determine the mechanical proprieties of polymethylmethacrylate (PMMA) and the improved compound, the graphene-based PMMA, with Zn and Ag and to compare the results. Scanning electron microscopy analysis of the samples before and after the mechanical test was conducted. The compression behavior, flexural properties, tensile strength, and shape of the samples were all investigated and compared between the variants of PMMA. Commercially available polymethylmethacrylate was used (Orthocryl
® -Dentaurum, Ispringen, Germany) with the salt and pepper technique according to the manufacturer's instructions to produce 20 samples for each mechanical trial with standard cylinders (4 mm diameter × 8 mm length) for compression, parallelepipedal prisms for flexing (2 mm × 2 mm × 25 mm) and flat samples for traction. There was no statistical difference in the mechanical proprieties of the samples evaluated, although there were values that could suggest significance. The graphene-based PMMA demonstrated good mechanical proprieties, like the commercially available PMMA, and appears promising for future clinical use based on its multiple advantages.- Published
- 2023
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26. Multi-modal access method (eye-tracking + switch-scanning) for individuals with severe motor impairment: A preliminary investigation.
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Fager SK, Sorenson T, Jakobs E, Koester H, Jakobs T, and Beukelman DR
- Subjects
- Humans, Eye-Tracking Technology, Computers, Motor Disorders
- Abstract
Individuals with severe motor impairments often require alternative means to access computers and communication technology. A range of alternative access devices exist; however, most rely on use of a single access modality. While this approach works for some individuals, it can be limiting for others. This study explored the use of a multi-modal prototype (eye-tracking + switch-scanning) on typing performance with a range of individuals with motor impairments. The multi-modal prototype was compared to eye-tracking alone for this study. Results indicated that the multi-modal prototype had significantly slower typing rate but significantly lower total errors compared to eye-tracking alone. Analysis of individual data revealed four subgroups of clinical relevance including individuals that 1) benefit from multi-modal, 2) benefit from eye-tracking, 3) demonstrate learning and 4) demonstrate fluctuating performance.
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- 2023
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27. Regenerative and Protective Effects on Dental Tissues of a Fluoride-Silicon-Rich Toothpaste Associated with a Calcium Booster: An In Vitro Study.
- Author
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Vilhena FV, Grecco SDS, González AHM, and D'Alpino PHP
- Abstract
Calcium boosters have been used as a supplement for fluoride toothpastes to repair the dental tissues and reduce dentin permeability. This in vitro study aimed to characterize the regenerative and protective effects of the treatment of dental tissues with a fluoride-silicon-rich toothpaste associated with a calcium booster. Bovine enamel and dentin blocks ( n = 5) were obtained (4 × 4 × 6 mm). A fluoride-silicon-rich toothpaste and a calcium booster were used to brush the enamel and dentin both immediately and five days afterwards. The outcomes were then compared to those of the untreated control group. After that, the specimens were cross-sectioned. SEM was used to evaluate the micromorphology of the surface and cross-section. Energy-dispersive X-ray spectroscopy (EDS) was used to determine the elemental analyses (weight%). After treatment for 5 days with a booster/silicon-rich toothpaste, EDS analysis demonstrated that it induced a significant mineral change. It was also able to form a protective silicon-enriched mineral layer on both enamel and dentin surfaces. It was demonstrated in vitro that a fluoride-silicon-rich toothpaste associated with a calcium booster regenerates the dental tissues, remineralizing the enamel structure and occluding the dentin tubules.
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- 2023
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28. Arrhythmogenicity of anti-tachycardia pacing in patients with implantable cardioverter defibrillator.
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Awad SS, Azeez EF, Taha MO, El-Naggar WM, and El-Damaty A
- Abstract
Background: Anti-tachycardia pacing therapy (ATP) has shown comparable efficacy to shock therapy in ventricular tachycardia (VT) termination with better quality of life. However, some ATPs may lead to VT acceleration or degeneration to ventricular fibrillation (VF), which will result in more ICD shocks. The aim of this study was to investigate the predictors of VT acceleration by ATP therapy in a real-life patient cohort., Results: We retrospectively reviewed 448 monomorphic VT episodes that required ATP therapy in 60 patients with structural heart diseases implanted with ICD or CRTD. The clinical data of the patients and the episodes' details were evaluated. We found that patients with a higher ejection fraction (EF) were more likely to be cardioverted by ATP therapy (P: 0.024). VT acceleration was more frequent in patients with lower EF (mean 31.24 ± 4.08) compared with the non-accelerated patients with higher EF (mean 37.00 ± 9.4, P: 0.016). The percentage of accelerated episodes was 8.5%. VT episodes with a mean cycle length (CL) < 310 ms are more likely to accelerate (sensitivity 76.3%, specificity 67.7%, PPV value 45%, NPV 86%, and AUC 0.790). There was a statistically significant difference in the accelerated VT episodes as compared to non-accelerated episodes regarding the number of ATP bursts (mean 3.66 ± 2.22 vs. 1.76 ± 1.35, P: < 0.001), ramp (23.7% vs. 4.2%, P: < 0.001), scanning (55.3% vs. 31.3%, P: 0.003) and burst adaptive cycle length (mean 83.55 ± 2.92 vs. 84.64 ± 2.61, P: 0.016). In a multivariate analysis, the VT CL, number of ATP bursts and ramp pacing predicted VT acceleration by ATP therapy., Conclusions: Ventricular tachycardia in patients with low LV EF and fast VTs with a CL less than 310 ms were more likely to accelerate with ATP therapy. The number of ATP bursts and the use of ramp had a significant effect on VT acceleration. To avoid VT acceleration by ATP therapy, ramp pacing better be avoided, especially in fast VTs, and lesser number of bursts should be delivered., (© 2023. The Author(s).)
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- 2023
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29. Head movement direction in football - a field study on visual scanning activity during the UEFA-U17 and -U21 European Championship 2019.
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Pokolm M, Kirchhain M, Müller D, Jordet G, and Memmert D
- Subjects
- Humans, Head Movements, Visual Perception, Foot, Soccer
- Abstract
Visual exploration (scanning) of one's environment is a key aspect in team sports. Based on Gibson's (1979) ecological approach of visual perception, this study aims to advance the understanding of scanning by focusing on the direction of head movements in football and its implications for subsequent on-ball actions. The video-based data analysis consisted of nine selected matches and 162 players of the Union of European Football Associations (UEFA) U17 and U21 European Championship 2019. The results indicate that the direction of the last scan prior to receiving the ball is related to the foot used for the first ball contact. This relationship was further analysed in view of the game context (direction of play and opponent pressure) and with information about the player's dominant foot. The findings reveal a relationship between the direction of the last scan before receiving the ball and the direction the game is proceeded in. Further, when a player performs the last scan to the side of their dominant foot, the probability increases that their dominant foot is used for the subsequent first ball contact. Depending on the direction of the last scan, opponent pressure had various effects on the foot used for the first contact.
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- 2023
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30. Autoencoders Based on 2D Convolution Implemented for Reconstruction Point Clouds from Line Laser Sensors.
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Klarák J, Klačková I, Andok R, Hricko J, Bulej V, and Tsai HY
- Abstract
Gradual development is moving from standard visual content in the form of 2D data to the area of 3D data, such as points scanned by laser sensors on various surfaces. An effort in the field of autoencoders is to reconstruct the input data based on a trained neural network. For 3D data, this task is more complicated due to the demands for more accurate point reconstruction than for standard 2D data. The main difference is in shifting from discrete values in the form of pixels to continuous values obtained by highly accurate laser sensors. This work describes the applicability of autoencoders based on 2D convolutions for 3D data reconstruction. The described work demonstrates various autoencoder architectures. The reached training accuracies are in the range from 0.9447 to 0.9807. The obtained values of the mean square error (MSE) are in the range from 0.059413 to 0.015829 mm. They are close to resolution in the Z axis of the laser sensor, which is 0.012 mm. The improvement of reconstruction abilities is reached by extracting values in the Z axis and defining nominal coordinates of points for the X and Y axes, where the structural similarity metric value is improved from 0.907864 to 0.993680 for validation data.
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- 2023
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31. A Novel Hands-on Approach Towards Teaching Diagnostic Radiology Residents MRI Scanning and Physics.
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Colucci PG, Gao MA, Schweitzer AD, Chang EW, Riyahi S, Taya M, Lu C, Ballon D, Min RJ, and Prince MR
- Subjects
- Humans, Curriculum, Magnetic Resonance Imaging, Health Physics education, Clinical Competence, Teaching, Radiology education, Internship and Residency
- Abstract
Rationale and Objectives: Traditional approaches towards teaching magnetic resonance imaging (MRI) scanning and physics have limitations that a hands-on course may help overcome. A dedicated week of MRI instruction may help improve radiology resident confidence and competence. Additional benefits may include improved physician-technologist communication and accelerated mastery of MRI safety., Materials and Methods: Surveys and tests were approved by our Program Evaluation Committee and administered at the beginning and at the end of this one-week course. The course consisted of protected reading time as well as practice scanning with a research magnet and assisting with clinical scanning under the close supervision of a licensed MRI technologist. Eighteen senior residents (nine third-year and nine fourth-year) participated in this course during its first year., Results: Few residents had previous experience with MRI physics, scanning, or research prior to residency. After this course, mean resident confidence increased by 0.47 points (3.33 vs 2.86; p=0.01) on a five-point Likert scale. Understanding of MRI physics, as measured by pre- and post-tests, increased by 22% (0.72 vs 0.50; p<0.01), corresponding to a large effect size of 1.29 (p<0.001). Resident feedback reported that this course was efficacious (5/5), engaging (4.9/5), and had optimal faculty oversight. The most highly rated component of the course was the opportunity to experiment with the research MR scanner (5/5)., Conclusion: A dedicated week of MRI education was highly rated by residents and associated with improvements in confidence and understanding, suggesting a positive correlation between confidence and competence. Additional metrics, such as trends in scores on the American Board of Radiology's Core Examination over the next several years, may further support the apparent benefits of this hands-on MR course., (Copyright © 2022 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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32. Imaging of Liver Tissues Using a Combination of Silver Impregnation and Low-Vacuum Scanning Electron Microscopy; A Simple Method for the High-Resolution Visualization of Reticulin Structures with Applicability to a Quantitative Analysis.
- Author
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Izuta M, Kuwamoto S, Kamiya T, Nagata K, Matsushita M, Inaga S, Kaido T, Umekita Y, Hayashi K, and Kitamura Y
- Abstract
Background: Low-vacuum scanning electron microscopy (LVSEM) enables the detailed three-dimensional imaging of archival tissues without special pretreatments. The clinical utility of LVSEM in the assessment of liver diseases has not yet been defined. So, we investigated the utility of LVSEM imaging in morphological assessments of normal and diseased liver tissues, with a focus on reticulin structures., Methods: Formalin-fixed tissue samples of two normal livers and two hepatocellular carcinomas with background regenerative nodules/areas were stained with platinum blue stain or silver-impregnated using Watanabe's method and then comparatively observed under LVSEM. We also evaluated the applicability of LVSEM imaging of liver tissues to a quantitative analysis using a digital image analysis technique., Results: Optimal high-resolution images of reticulin structures were obtained using 10-μm-thick silver-impregnated sections. Reticulin fibers were clearly observed to run dendritically around sinusoids in normal livers, and markedly increased in regenerative nodules/areas. Normal reticulin frameworks were lost in hepatocellular carcinoma, leaving a few fragments of reticulin fibers within tumors. Moreover, when a quantitative analysis was applied to these images, we successfully demonstrated a significantly higher reticulin fiber density in regenerative nodules/areas than in the normal liver ( P < 0.05)., Conclusion: We not only obtained detailed three-dimensional images of reticulin structures in various liver tissues by LVSEM combined with silver impregnation but also showed their applicability to a quantitative analysis. The method presented herein may be applied to future studies for the more accurate diagnosis and better classification/risk stratification of various liver diseases., Competing Interests: The authors declare no conflict of interest., (©2023 Tottori University Medical Press.)
- Published
- 2023
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33. Automation of Measurements for Personalized Medical Appliances by Means of CAD Software-Application in Robin Sequence Orthodontic Appliances.
- Author
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Aretxabaleta M, Roehler A, Poets CF, Xepapadeas AB, Koos B, and Weise C
- Abstract
Measuring the dimensions of personalized devices can provide relevant information for the production of future such devices used in various medical specialties. Difficulties with standardizing such measurement and obtaining high accuracy, alongside cost-intensive measuring methodologies, has dampened interest in this practice. This study presents a methodology for automatized measurements of personalized medical appliances of variable shape, in this case an orthodontic appliance known as Tübingen Palatal Plate (TPP). Parameters such as length, width and angle could help to standardize and improve its future use. A semi-automatic and custom-made program, based on Rhinoceros 7 and Grasshopper, was developed to measure the device (via an extraoral scanner digital file). The program has a user interface that allows the import of the desired part, where the user is able to select the necessary landmarks. From there, the program is able to process the digital file, calculate the necessary dimensions automatically and directly export all measurements into a document for further processing. In this way, a solution for reducing the time for measuring multiple dimensions and parts while reducing human error can be achieved.
- Published
- 2022
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34. Benefits of 3D Printed and Customized Anatomical Footwear Insoles for Plantar Pressure Distribution.
- Author
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Jandova S and Mendricky R
- Abstract
During walking, the foot is in direct contact with the insole of the footwear, and it affects the biomechanics of the whole human body. The aim of this study was to compare the plantar pressure distribution while walking in the same footwear in three different situations: with an original footwear insole, with an ethylene-vinyl acetate customized insole, and with a 3D printed anatomical insole to find out the optimal insoles for people with a normal, flat, and high arched foot according to the plantar pressure relief. Fifty-one adults were grouped into three groups (normal foot, flat foot, and high arched foot geometry). The feet of the randomly selected subjects from each group were scanned, and the insoles were designed on the basis of the foot model. These models were then used for the 3D printing. The plantar pressure distribution was observed when walking in all three different insole types for each of the three subjects with the different foot types. The peak pressure values in the forefoot, midfoot, and rearfoot and contact area were compared. The results of the study show that customized insoles influence the plantar pressure distribution mainly in people with a flat foot or with a high arched foot deformity. This influence is dependent on the type of the customized insoles, mainly in people with a high arched foot. People with a flat foot deformity have a similar plantar pressure relief in the thermoplastic insoles as those in the 3D printed insoles, and both these customized insoles can be used as a supplementary therapeutic instrument. Our study showed that the biggest attention, with regards to customizing insoles, is required by people with a high arched foot deformity, and we recommend that these people use fully customized insoles which can be guaranteed with 3D printing techniques., Competing Interests: No competing financial interests exist. There was no conflict of interest., (Copyright 2022, Mary Ann Liebert, Inc., publishers.)
- Published
- 2022
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35. An overview of three-dimensional imaging devices in dentistry.
- Author
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Hou X, Xu X, Zhao M, Kong J, Wang M, Lee ES, Jia Q, and Jiang HB
- Subjects
- Face, Dentistry, Imaging, Three-Dimensional, Cone-Beam Computed Tomography
- Abstract
Objective: To review four types of three-dimensional imaging devices: intraoral scanners, extraoral scanners, cone-beam computed tomography (CBCT), and facial scanners, in terms of their development, technologies, advantages, disadvantages, accuracy, influencing factors, and applications in dentistry., Methods: PubMed (National Library of Medicine) and Google Scholar databases were searched. Additionally, the scanner manufacturers' websites were accessed to obtain relevant data. Four authors independently selected the articles, books, and websites. To exclude duplicates and scrutinize the data, they were uploaded to Mendeley Data. In total, 135 articles, two books, and 17 websites were included., Results: Research and clinical practice have shown that oral and facial scanners and CBCT can be used widely in various areas of dentistry with high accuracy., Conclusion: Although further advancement of these devices is desirable, there is no doubt that digital technology represents the future of dentistry. Furthermore, the combined use of different devices may bring dentistry into a new era. These four devices will play a significant role in clinical utility with high accuracy. The combined use of these devices should be explored further., Clinical Significance: The four devices will play a significant role in clinical use with high accuracy. The combined use of these devices should be explored further., (© 2022 Wiley Periodicals LLC.)
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- 2022
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36. Delivery of intensity-modulated electron therapy by mechanical scanning: An algorithm study.
- Author
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Ma P, Tian Y, Li M, Niu C, Song Y, and Dai J
- Abstract
Purpose: In principle, intensity-modulated electron therapy (IMET) can be delivered through mechanical scanning, with a robotic arm mounting a linac., Materials and Methods: Here is a scanning algorithm to identify the back-and-forth, top-to-bottom (zigzag) pattern scan sequence. The algorithm includes generating beam positions with a uniform resolution according to the applicator size; adopting discrete energies to achieve the depth of 90% dose by compositing energies; selecting energy by locating the target's distal edge; and employing the energy-by-energy scan strategy for step-and-shoot discrete scanning. After a zigzag scan sequence is obtained, the delivery order of the scan spots is optimized by fast simulated annealing (FSA) to minimize the path length. For algorithm evaluation, scan sequences were generated using the computed tomography data of 10 patients with pancreatic cancer undergoing intraoperative radiotherapy, and the results were compared between the zigzag path and an optimized path. A simple calculation of the treatment delivery time, which comprises the irradiation time, the total robotic arm moving time, the time for energy switch, and the time to stop and restart the beam, was also made., Results: In these clinical cases, FSA optimization shortened the path lengths by 12%-43%. Assuming the prescribed dose was 15 Gy, machine dose rate was 15 Gy/s, energy switch time was 2 s, stop and restart beam time was 20 ms, and robotic arm move speed was 50 mm/s, the average delivery time was 124±38 s. The largest reduction in path length yielded an approximately 10% reduction in the delivery time, which can be further reduced by increasing the machine dose rate and the robotic arm speed, decreasing the time for energy switch, and/or developing more efficient algorithms., Conclusion: Mechanically scanning IMET is potentially feasible and worthy of further exploration., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ma, Tian, Li, Niu, Song and Dai.)
- Published
- 2022
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37. Rapid 40S scanning and its regulation by mRNA structure during eukaryotic translation initiation.
- Author
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Wang J, Shin BS, Alvarado C, Kim JR, Bohlen J, Dever TE, and Puglisi JD
- Subjects
- Codon, Initiator metabolism, RNA, Messenger metabolism, 5' Untranslated Regions, Adenosine Triphosphate metabolism, Peptide Chain Initiation, Translational, Protein Biosynthesis, Ribosomes metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism
- Abstract
How the eukaryotic 43S preinitiation complex scans along the 5' untranslated region (5' UTR) of a capped mRNA to locate the correct start codon remains elusive. Here, we directly track yeast 43S-mRNA binding, scanning, and 60S subunit joining by real-time single-molecule fluorescence spectroscopy. 43S engagement with mRNA occurs through a slow, ATP-dependent process driven by multiple initiation factors including the helicase eIF4A. Once engaged, 43S scanning occurs rapidly and directionally at ∼100 nucleotides per second, independent of multiple cycles of ATP hydrolysis by RNA helicases post ribosomal loading. Scanning ribosomes can proceed through RNA secondary structures, but 5' UTR hairpin sequences near start codons drive scanning ribosomes at start codons backward in the 5' direction, requiring rescanning to arrive once more at a start codon. Direct observation of scanning ribosomes provides a mechanistic framework for translational regulation by 5' UTR structures and upstream near-cognate start codons., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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38. Efficiency when scanning old ophthalmologic slides.
- Author
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Sevillano C
- Subjects
- Humans, Microscopy methods
- Abstract
Objective: To digitise our old archive and evaluate the efficiency of this task, both in medical and economic terms., Material and Methods: All slides and negatives (8254) archived in our clinic were collected, digitised with a 5-megapixel slide scanner. The images were taken from 1972 to 1999. Quality and utility of images were taken into account, as far as costs of the task (up to 2100 euros), all the work done by the same ophthalmologist., Results: Of those identifiable, 62% of the patients had already died. Only 1.5% were archived for use; 70 images for teaching reasons and 60 for medical reasons, being incorporated into the patient's history. About 210h were spent on scanning, identifying, checking and uploading images. 84% corresponded to retinal pathology, 4% to glaucomatous pathology, 3% to anterior segment pathology and the last 9% to learning material. The quality of most images is good, and, in some cases, were important for the correct diagnosis of the pathology. If only medical reasons are taken into account, the number of images uploaded is very low when working with archives older than 50 years., Conclusions: Although there was a low percentage of scanned images, the task was efficient because of a low cost. Images older than 50 years must be evaluated before scanning because of their low utility., (Copyright © 2022 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)
- Published
- 2022
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39. The efficacy of computed tomography scanning versus surface scanning in 3D finite element analysis.
- Author
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Rowe AJ and Rayfield EJ
- Subjects
- Finite Element Analysis, Mathematics, Radionuclide Imaging, Mandible anatomy & histology, Tomography, X-Ray Computed
- Abstract
Finite element analysis (FEA) is a commonly used application in biomechanical studies of both extant and fossil taxa to assess stress and strain in solid structures such as bone. FEA can be performed on 3D structures that are generated using various methods, including computed tomography (CT) scans and surface scans. While previous palaeobiological studies have used both CT scanned models and surface scanned models, little research has evaluated to what degree FE results may vary when CT scans and surface scans of the same object are compared. Surface scans do not preserve the internal geometries of 3D structures, which are typically preserved in CT scans. Here, we created 3D models from CT scans and surface scans of the same specimens (crania and mandibles of a Nile crocodile, a green sea turtle, and a monitor lizard) and performed FEA under identical loading parameters. It was found that once surface scanned models are solidified, they output stress and strain distributions and model deformations comparable to their CT scanned counterparts, though differing by notable stress and strain magnitudes in some cases, depending on morphology of the specimen and the degree of reconstruction applied. Despite similarities in overall mechanical behaviour, surface scanned models can differ in exterior shape compared to CT scanned models due to inaccuracies that can occur during scanning and reconstruction, resulting in local differences in stress distribution. Solid-fill surface scanned models generally output lower stresses compared to CT scanned models due to their compact interiors, which must be accounted for in studies that use both types of scans., Competing Interests: The authors declare there are no competing interests., (©2022 Rowe and Rayfield.)
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- 2022
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40. Design of the Automated Calibration Process for an Experimental Laser Inspection Stand.
- Author
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Klarák J, Andok R, Hricko J, Klačková I, and Tsai HY
- Subjects
- Calibration, Fourier Analysis, Lasers, Software
- Abstract
This paper deals with the concept of the automated calibration design for inspection systems using laser sensors. The conceptual solution is based on using a laser sensor and its ability to scan 3D surfaces of inspected objects in order to create a representative point cloud. Problems of scanning are briefly discussed. The automated calibration procedure for solving problems of errors due to non-precise adjustment of the mechanical arrangement, possible tolerances in assembly, and their following elimination is proposed. The main goal is to develop a system able to measure and quantify the quality of produced objects in the environment of Industry 4.0. Laboratory measurements on the experimental stand, including the principal software solution for automated calibration of laser sensors suitable for gear wheel inspection systems are presented. There is described design of compensation eccentricity by Fourier transform and sinusoidal fitting to identify and suppress the first harmonic component in the data with high precision measuring.
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- 2022
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41. Evaluating person-centered factors associated with brain-computer interface access to a commercial augmentative and alternative communication paradigm.
- Author
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Pitt KM and Brumberg JS
- Subjects
- Cognition, Communication, Electroencephalography, Humans, Amyotrophic Lateral Sclerosis, Brain-Computer Interfaces, Communication Devices for People with Disabilities
- Abstract
Current BCI-AAC systems largely utilize custom-made software and displays that may be unfamiliar to AAC stakeholders. Further, there is limited information available exploring the heterogenous profiles of individuals who may use BCI-AAC. Therefore, in this study, we aimed to evaluate how individuals with amyotrophic lateral sclerosis (ALS) learned to control a motor-based BCI switch in a row-column AAC scanning pattern, and person-centered factors associated with BCI-AAC performance. Four individuals with ALS completed 12 BCI-AAC training sessions, and three individuals without neurological impairment completed 3 BCI-AAC training sessions. To assess person-centered factors associated with BCI-AAC performance, participants completed both initial and recurring assessment measures including levels of cognition, motor ability, fatigue, and motivation. Three of four participants demonstrated either BCI-AAC performance in the range of neurotypical peers, or an improving BCI-AAC learning trajectory. However, BCI-AAC learning trajectories were variable. Assessment measures revealed that two participants presented with a suspicion for cognitive impairment yet achieved the highest levels of BCI-AAC accuracy with their increased levels of performance being possibly supported by largely unimpaired motor skills. Motor-based BCI switch access to a commercial AAC row-column scanning may be feasible for individuals with ALS and possibly supported by timely intervention.
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- 2022
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42. Opportunities and Limitations of a Gaze-Contingent Display to Simulate Visual Field Loss in Driving Simulator Studies.
- Author
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Biebl B, Arcidiacono E, Kacianka S, Rieger JW, and Bengler K
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Background: Research on task performance under visual field loss is often limited due to small and heterogenous samples. Simulations of visual impairments hold the potential to account for many of those challenges. Digitally altered pictures, glasses, and contact lenses with partial occlusions have been used in the past. One of the most promising methods is the use of a gaze-contingent display that occludes parts of the visual field according to the current gaze position. In this study, the gaze-contingent paradigm was implemented in a static driving simulator to simulate visual field loss and to evaluate parallels in the resulting driving and gaze behavior in comparison to patients., Methods: The sample comprised 15 participants without visual impairment. All the subjects performed three drives: with full vision, simulated left-sided homonymous hemianopia, and simulated right-sided homonymous hemianopia, respectively. During each drive, the participants drove through an urban environment where they had to maneuver through intersections by crossing straight ahead, turning left, and turning right., Results: The subjects reported reduced safety and increased workload levels during simulated visual field loss, which was reflected in reduced lane position stability and greater absence of large gaze movements. Initial compensatory strategies could be found concerning a dislocated gaze position and a distorted fixation ratio toward the blind side, which was more pronounced for right-sided visual field loss. During left-sided visual field loss, the participants showed a smaller horizontal range of gaze positions, longer fixation durations, and smaller saccadic amplitudes compared to right-sided homonymous hemianopia and, more distinctively, compared to normal vision., Conclusion: The results largely mirror reports from driving and visual search tasks under simulated and pathological homonymous hemianopia concerning driving and scanning challenges, initially adopted compensatory strategies, and driving safety. This supports the notion that gaze-contingent displays can be a useful addendum to driving simulator research with visual impairments if the results are interpreted considering methodological limitations and inherent differences to the pathological impairment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Biebl, Arcidiacono, Kacianka, Rieger and Bengler.)
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- 2022
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43. The marginal gaps of lithium disilicate crowns constructed by different scanner and milling unit combinations.
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Su S and Dudley J
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- Ceramics, Computer-Aided Design, Crowns, Dental Impression Technique, Dental Porcelain, Humans, Dental Marginal Adaptation, Dental Prosthesis Design
- Abstract
Background: The purpose of this study was to compare the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using three different scanner and milling unit combinations., Methods: Twenty-four Columbia model lower left molars were prepared for LDS crowns by undergraduate students in a simulated environment. One LDS crown was constructed for each crown preparation using each of the following intraoral scanner/milling unit combinations: TRIOS 3 scanner/E4D milling unit (TRIO/E4DM); TRIOS 3 scanner/Sirona inLab MC X5 milling unit (TRIO/MCX5); E4D scanner/E4D milling unit (E4DS/E4DM). The crowns were seated onto the original crown preparations and three vertical marginal gap measurements taken at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal) using a stereomicroscope. The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface., Results: The TRIO/MCX5 scanner/milling unit combination produced the smallest MMG of 63.73 ± 47.38 μm followed by E4DS/E4DM (88.64 ± 106.51 μm) and TRIO/E4DM (107.41 ± 76.47 μm). There was a significant effect of milling unit (p < 0.0001) on MMG but no significant effect of scanner (p = 0.070) or location (p = 0.182)., Conclusions: The newer scanner/milling unit combination produced LDS crowns with the smallest MMG. All scanner/milling unit combinations produced LDS crowns within a clinically acceptable MMG., (© 2021 Australian Dental Association.)
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- 2022
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44. Digital model superimpositions: are different software algorithms equally accurate in quantifying linear tooth movements?
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Adel SM, Vaid NR, El-Harouni N, Kassem H, and Zaher AR
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- Algorithms, Humans, Mandible, Software, Imaging, Three-Dimensional methods, Models, Dental
- Abstract
Background: To evaluate the accuracy of three different 3D digital model registration software packages for linear tooth movement measurements, with reference to a 3D digital virtual setup (DS)., Methods: Twenty maxillary and mandibular pre-treatment scans of patients undergoing clear aligner therapy were used. Digital Setups were generated from pre-treatment scans using OrthoAnalyzer software. Both the pretreatment digital scans (T1) and Digital Setups (T2) were converted to STL files to be imported to the three studied software packages: Geomagic, OrthoAnalyzer and Compare. Linear changes in tooth positions were calculated for all the registered pairs., Results: The change in tooth position was compared between the calculated tooth movement using each of the registration software packages versus the actual generated tooth movement from the Digital Setups. Continuous data was expressed as mean and standard deviation. Intraclass Correlation Coefficients for agreements between Digital Simulation and each software was used. Intra and Inter-examiner reliabilities were also assessed using Intraclass Correlation Coefficients. Significance of the obtained results was expressed at p ≤ 0.01. Geomagic software showed agreements > 0.90 for maxillary linear tooth movements and between 0.75 and 0.90 for mandibular measurements. OrthoAnalyzer software showed agreements between 0.50 and < 0.75 for maxillary and mandibular measurements. Compare software showed agreements > 0.90 for maxillary and mandibular linear tooth movements, indicating the best consistency., Conclusions: Compare and Geomagic software packages consistently showed maximum accuracy in measuring the amount of tooth movement in the maxillary arch compared to the reference standard. Compare software showed the highest agreements in the mandibular arch. None of the three studied software packages showed poor agreement with the Digital Setup across all tooth movement measurements. Buccolingual tooth movements showed the highest agreements amongst linear measurements., (© 2022. The Author(s).)
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- 2022
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45. Virtual reality validation of naturalistic modulation strategies to counteract fading in retinal stimulation.
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Thorn JT, Chenais NAL, Hinrichs S, Chatelain M, and Ghezzi D
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- Electric Stimulation, Humans, Phosphenes, Retina, Retinal Ganglion Cells, Vision, Ocular, Virtual Reality, Visual Prosthesis
- Abstract
Objective . Temporal resolution is a key challenge in artificial vision. Several prosthetic approaches are limited by the perceptual fading of evoked phosphenes upon repeated stimulation from the same electrode. Therefore, implanted patients are forced to perform active scanning, via head movements, to refresh the visual field viewed by the camera. However, active scanning is a draining task, and it is crucial to find compensatory strategies to reduce it. Approach . To address this question, we implemented perceptual fading in simulated prosthetic vision using virtual reality. Then, we quantified the effect of fading on two indicators: the time to complete a reading task and the head rotation during the task. We also tested if stimulation strategies previously proposed to increase the persistence of responses in retinal ganglion cells to electrical stimulation could improve these indicators. Main results . This study shows that stimulation strategies based on interrupted pulse trains and randomisation of the pulse duration allows significant reduction of both the time to complete the task and the head rotation during the task. Significance . The stimulation strategy used in retinal implants is crucial to counteract perceptual fading and to reduce active head scanning during prosthetic vision. In turn, less active scanning might improve the patient's comfort in artificial vision., (Creative Commons Attribution license.)
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- 2022
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46. Dual amplification enabled counting based ultrasensitive enzyme-linked immunosorbent assay.
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Liu H and Lei Y
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- Animals, Enzyme-Linked Immunosorbent Assay methods, Mice, Reproducibility of Results, Alkaline Phosphatase
- Abstract
ELISA is a predominant technique in the detection of biomarkers. Notwithstanding its ubiquity and numerous advantages, its application for detection of low abundant biomarkers requires the ultrasensitivity. To bridge the gap between the need and availability, an innovative dual amplification enabled counting based ELISA was developed for ultrasensitive detection of mouse total IgG (a model biomarker). The dual amplification strategy, which is compatible with conventional plate-based ELISA, was realized through tyramide signal amplification (TSA) and alkaline phosphatase enabled formation of fluorescent precipitates. The counting of fluorescent precipitates in 25 images of each well can correlate the number of precipitates to the concentration of IgG with good linearity and lower the limit of detection of the commercial mouse IgG kit (1.56 ng/mL) to 54.5 pg/mL. Recovery tests further demonstrate the reliability of the developed method. This study opens a new avenue to improve the sensitivity of conventional plate-based ELISA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2022
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47. TIP, TORQUE & ROTATIONS: How accurately do digital superimposition software packages quantify tooth movement?
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Adel SM, Vaid NR, El-Harouni N, Kassem H, and Zaher AR
- Subjects
- Humans, Maxilla, Software, Torque, Mandible, Tooth Movement Techniques
- Abstract
Background: To investigate the accuracy of three different 3D digital model registration software for tip, torque and rotation measurements, with reference to a 3D digital virtual setup. Twenty maxillary and mandibular pre-treatment scans of patients undergoing clear aligner therapy were used. Digital setups were generated from pre-treatment scans using a tooth movement software. Both the pretreatment digital scans (T1) and digital setups (T2) were converted to STL files to be exported to the 3 studied software that employed: (1) Semiautomatic best fit registration (S-BF), (2) Interactive surface-based registration (I-SB), and (3) Automatic best fit registration (A-BF) respectively. Changes in tip, torque and rotation were calculated for all the registered pairs., Results: The change in tooth position was compared between the calculated tooth movement using each of the registration software packages versus the actual generated tooth movement from the digital setups. Continuous data was expressed as mean and standard deviation. Intra Class Correlation Coefficient for agreement between digital simulation and each software was used. Intra and Inter-examiner reliabilities were also assessed using Intra Class Correlation Coefficient. Significance of the obtained results was expressed at p ≤ 0.01. Semiautomatic best fit registration software showed excellent agreement (> 0.90) for all tooth movements, except for good agreement for torque (0.808). Interactive surface-based registration software showed moderate agreement for all measurements (0.50 and < 0.75), except for good agreement for rotation (0.783). Automatic best fit registration software demonstrated excellent agreement (> 0.90) for rotation, good agreement for tip (0.890) and moderate agreement for torque (0.740)., Conclusions: Overall, semiautomatic best fit registration software consistently showed excellent agreement in superimpositions compared to other software types. Automatic best fit registration software consistently demonstrated better agreement for mandibular superimpositions, compared to others. Accuracy of digital model superimpositions for tooth movements studied in superimposition studies, can be attributed to the algorithm employed for quantification., (© 2022. The Author(s).)
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- 2022
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48. FLASH radiotherapy with carbon ion beams.
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Weber UA, Scifoni E, and Durante M
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- Ions therapeutic use, Protons, Radiobiology, Radiotherapy methods, Radiotherapy Dosage, Carbon therapeutic use, Radiation Oncology
- Abstract
FLASH radiotherapy is considered a new potential breakthrough in cancer treatment. Ultra-high dose rates (>40 Gy/s) have been shown to reduce toxicity in the normal tissue without compromising tumor control, resulting in a widened therapeutic window. These high dose rates are more easily achievable in the clinic with charged particles, and clinical trials are, indeed, ongoing using electrons or protons. FLASH could be an attractive solution also for heavier ions such as carbon and could even enhance the therapeutic window. However, it is not yet known whether the FLASH effect will be the same as for sparsely ionizing radiation when densely ionizing carbons ions are used. Here we discuss the technical challenges in beam delivery and present a promising solution using 3D range-modulators in order to apply ultra-high dose rates (UHDR) compatible with FLASH with carbon ions. Furthermore, we will discuss the possible outcome of C-ion therapy at UHDR on the level of the radiobiological and radiation chemical effects., (© 2021 The Authors. Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)
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- 2022
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49. uS5/Rps2 residues at the 40S ribosome entry channel enhance initiation at suboptimal start codons in vivo.
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Dong J and Hinnebusch AG
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- Codon, Initiator genetics, Peptide Chain Initiation, Translational, Ribosomal Proteins genetics, Ribosomal Proteins metabolism, Ribosome Subunits, Small, Eukaryotic metabolism, Ribosome Subunits, Small, Eukaryotic genetics, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism, Saccharomyces cerevisiae Proteins chemistry
- Abstract
The eukaryotic 43S pre-initiation complex (PIC) containing Met-tRNAiMet in a ternary complex (TC) with eIF2-GTP scans the mRNA leader for an AUG codon in favorable "Kozak" context. AUG recognition triggers rearrangement of the PIC from an open conformation to a closed state with more tightly bound Met-tRNAiMet. Yeast ribosomal protein uS5/Rps2 is located at the mRNA entry channel of the 40S subunit in the vicinity of mRNA nucleotides downstream from the AUG codon or rRNA residues that communicate with the decoding center, but its participation in start codon recognition was unknown. We found that nonlethal substitutions of conserved Rps2 residues in the entry channel reduce bulk translation initiation and increase discrimination against poor initiation codons. A subset of these substitutions suppress initiation at near-cognate UUG start codons in a yeast mutant with elevated UUG initiation, and also increase discrimination against AUG codons in suboptimal Kozak context, thus resembling previously described substitutions in uS3/Rps3 at the 40S entry channel or initiation factors eIF1 and eIF1A. In contrast, other Rps2 substitutions selectively discriminate against either near-cognate UUG codons, or poor Kozak context of an AUG or UUG start codon. These findings suggest that different Rps2 residues are involved in distinct mechanisms involved in discriminating against different features of poor initiation sites in vivo., (Published by Oxford University Press on behalf of Genetics Society of America 2021. This work is written by US Government employees and is in the public domain in the US.)
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- 2022
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50. Large volume scanning laser induced fluorescence measurement of a bluff-body stabilised flame in an annular combustor.
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Govender D, Wiseman S, Dawson JR, and Worth NA
- Abstract
Abstract: This study outlines a variant of three-dimensional OH planar laser-induced fluorescence and its application in characterising a single bluff body stabilised flame inside a 12 burner annular combustor. In this variant of the method a relatively large volume was scanned slowly in order to calculate the full three-dimensional Flame Surface Density (FSD) distribution. The method used a combination of two scanning directions to overcome bias errors associated with laser sheet positions close to the flame edges. The source of this bias error was confirmed numerically through a complimentary synthetic PLIF study, which was also used to refine the experimental setup. The bias error resulted in a reduction of FSD magnitude, although the method was still capable of capturing the flame structure. This was demonstrated by comparing the reconstructions from the two independent scan directions. Combining the data from both directions overcame the bias, and allowed flame asymmetry due to the confinement to be assessed. The FSD was used to determine the heat release rate of the flame with varying local azimuthal angle for different downstream regions. This highlighted the highly asymmetric structure, produced by the asymmetric confinement., (© The Author(s) 2022.)
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- 2022
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