26 research outputs found

    Integrating VR, AR, and Haptics in Basic Surgical Skills Training: a Review and Perspective

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    Traditional surgical training faces challenges related to sustainability, cost, and ethical considerations. Limited access to resources, ethical concerns about cadaver-based learning, limited availability of surgical cases, and the high costs associated with hands-on training impede the effectiveness and accessibility of surgical education. Despite these challenges, the need for direct tactile experience remains critical, as it fosters the development of essential motor skills and tactile abilities vital for surgical practice. However, advancements in immersive technologies such as virtual reality (VR), augmented reality (AR), and haptics offer a promising solution to address these challenges. VR and AR technologies offer realistic, controlled environments where learners can visualise anatomical structures and practice surgical procedures without risks. The integration of haptic feedback in these immersive simulations further enriches the learning process by adding the sense of touch and physical interaction, aiding in mastering critical surgical skills. The incorporation of immersive technologies in surgical training presents an opportunity to address the constraints of conventional methods. These technologies offer the possibility of creating platforms that replicate real-life surgical scenarios, allowing learners to hone their skills and build confidence in a safe and controlled environment. Moreover, immersive learning offers an ethical alternative to cadaver-based training and extends access to training materials irrespective of geographical limitations. Such an approach allows for step-based training, where students may begin acquiring skills through immersive learning, then move to special surgical simulators, and finally to patients. This article deals with the impact of immersive technologies such as VR, AR, and haptics on reshaping conventional surgical training, by focusing specifically on basic surgical skills. Targeting educators, medical experts, and involved parties, the article aims to stimulate additional exploration and adoption of immersive technologies to elevate surgical competencies and patient care standards

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Assessment of Impact Energy Harvesting in Composite Beams with Piezoelectric Transducers

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    Piezoelectric energy harvesting (PEH) is studied in the case of a low-velocity impact of a rigid mass on a composite beam. A methodology is outlined, encompassing modelling of the open-circuit impact response in a finite element (FE) package, formulation of a lumped parameter (LP) model for the piezoelectric transducer connected with the harvesting circuit, and experimental verification of the impact using a custom portable configuration with impactor motion control. The subcircuit capacitor charging effect, the impactor mass and velocity on the harvesting subcircuit response, and the obtained output power are quantified. The results indicate that the current methodology can be used as a design tool for the structure and the harvesting circuit to achieve power output from composite beams with piezoelectric patches under impact conditions.</jats:p

    Assessment of Impact Energy Harvesting in Composite Beams with Piezoelectric Transducers

    No full text
    Piezoelectric energy harvesting (PEH) is studied in the case of a low-velocity impact of a rigid mass on a composite beam. A methodology is outlined, encompassing modelling of the open-circuit impact response in a finite element (FE) package, formulation of a lumped parameter (LP) model for the piezoelectric transducer connected with the harvesting circuit, and experimental verification of the impact using a custom portable configuration with impactor motion control. The subcircuit capacitor charging effect, the impactor mass and velocity on the harvesting subcircuit response, and the obtained output power are quantified. The results indicate that the current methodology can be used as a design tool for the structure and the harvesting circuit to achieve power output from composite beams with piezoelectric patches under impact conditions

    Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers

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    A finite element-based methodology is introduced for studying composite beams with piezoelectric transducers connected to energy harvesting circuits. Continuous and lumped-parameter models are developed based on finite element approximations and verified by means of experiments performed on a cantilever beam subjected to sinusoidal excitation at low, with respect to resonance, frequencies below 15 Hz. Three harvesting circuits have been studied: an in-house, a commercial, modified to include a rectification stage, and an off-the-shelf commercial. Comparison of numerical predictions with experiments illustrates good agreement in voltage and high sensitivity to current losses in the circuit. It was found that the commercial circuits outperform the in-house circuit in terms of harvested power at frequencies higher than 5 Hz, while the latter enables power harvesting at arbitrary low frequencies. Based on these results, it is demonstrated that the developed approach enables coupled simulation of a composite structure and a realistic harvesting circuit in one-shot. </jats:p

    A Sensing Role of the Glutamine Synthetase in the Nitrogen Regulation Network in Fusarium fujikuroi

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    Contains fulltext : 125173.pdf (publisher's version ) (Open Access)In the plant pathogenic ascomycete Fusarium fujikuroi the synthesis of several economically important secondary metabolites (SM) depends on the nitrogen status of the cells. Of these SMs, gibberellin and bikaverin synthesis is subject to nitrogen catabolite repression (NCR) and is therefore only executed under nitrogen starvation conditions. How the signal of available nitrogen quantity and quality is sensed and transmitted to transcription factors is largely unknown. Earlier work revealed an essential regulatory role of the glutamine synthetase (GS) in the nitrogen regulation network and secondary metabolism as its deletion resulted in total loss of SM gene expression. Here we present extensive gene regulation studies of the wild type, the Deltagln1 mutant and complementation strains of the gln1 deletion mutant expressing heterologous GS-encoding genes of prokaryotic and eukaryotic origin or 14 different F. fujikuroi gln1 copies with site-directed mutations. All strains were grown under different nitrogen conditions and characterized regarding growth, expression of NCR-responsive genes and biosynthesis of SM. We provide evidence for distinct roles of the GS in sensing and transducing the signals to NCR-responsive genes. Three site directed mutations partially restored secondary metabolism and GS-dependent gene expression, but not glutamine formation, demonstrating for the first time that the catalytic and regulatory roles of GS can be separated. The distinct mutant phenotypes show that the GS (1) participates in NH4 (+)-sensing and transducing the signal towards NCR-responsive transcription factors and their subsequent target genes; (2) affects carbon catabolism and (3) activates the expression of a distinct set of non-NCR GS-dependent genes. These novel insights into the regulatory role of the GS provide fascinating perspectives for elucidating regulatory roles of GS proteins of different organism in general

    sj-pdf-2-pil-10.1177_14644207211046585 - Supplemental material for Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers

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    Supplemental material, sj-pdf-2-pil-10.1177_14644207211046585 for Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers by Theofanis S. Plagianakos, Nikolaos Margelis, Nikolaos Leventakis, Georgios Bolanakis, Panagiotis Vartholomeos and Evangelos G. Papadopoulos in Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications</p

    Interferon-gamma release assay clarifies the effect of bacille Calmette-Guerin vaccination in Greek army recruits

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    OBJECTIVE: To compare the most recent commercial interferon-gamma release assay (IGRA), the QuantiFERON-TB Gold In-Tube (QFT-GIT), with the tuberculin skin test (TST) in Greek army recruits who were bacille Calmette-Guerin (BCG) vaccinated during childhood and had no history of tuberculosis (TB) exposure. METHOD: We conducted a cross-sectional comparison study of 1750 young army recruits. TST was performed on all participants, while QFT-GIT was performed in all subjects with TST > 0 mm and in 18 TST-negative controls (TST = 0 mm). RESULTS: Among the study subjects, 5.4% (96/1750) had TST indurations of >or=10 mm, and 3.4% (59/1750) had indurations of >or=15 mm. Among subjects with a positive TST, 11.4% (11/96) tested positive on QFT-GIT. All those with QFT-GIT positivity had TST indurations of >or=15 mm, and none of those with TST indurations of 10-14 mm were positive by QFT-GIT. The overall agreement between TST and QFT-GIT was poor (kappa = 0.02). CONCLUSION: We found a significant discordance between TST and QFT-GIT in BCG-vaccinated Greek army recruits consistent with previous studies showing that BCG received after infancy produces false-positive TST reactions. Our findings underline the need for a two-step approach in diagnosing latent TB infection in all BCG-vaccinated individuals: initial TST screening, followed by an IGRA to confirm TST positivity.Int J Tuberc Lung Di

    sj-doc-3-pil-10.1177_14644207211046585 - Supplemental material for Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers

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    Supplemental material, sj-doc-3-pil-10.1177_14644207211046585 for Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers by Theofanis S. Plagianakos, Nikolaos Margelis, Nikolaos Leventakis, Georgios Bolanakis, Panagiotis Vartholomeos and Evangelos G. Papadopoulos in Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications</p
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