286 research outputs found

    Multiplateau structure in photoemission spectra of strong-field ionization of dense media

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    Strong-field ionization of dense molecular gases in a short infrared laser pulse is studied by means of photoelectron spectroscopy combined with a liquid microjet technique. By increasing the gas density, we observe how the laser- assisted electron scattering on neighboring particles becomes a dominant mechanism of hot electron emission. The angle-resolved energy distributions of rescattered electrons are obtained by analyzing the density dependency of emission spectra. A semiclassical consideration of electron trajectories is shown to provide a good description of experimental spectra. The model predicts the existence of four energy plateaus. Two cutoffs at higher energies are evident in the spectra

    Trauma simulation training: a randomized controlled trial -evaluating the effectiveness of the Imperial Femoral Intramedullary Nailing Cognitive Task Analysis (IFINCTA) tool

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    Background and purpose - Cognitive task analysis (CTA) has been used extensively to train pilots and in other surgical specialties. However, the use of CTA within orthopedics is in its infancy. We evaluated the effectiveness of a novel CTA tool to improve understanding of the procedural steps in antegrade femoral intramedullary nailing. Material and methods - Design: A modified Delphi technique was used to generate a CTA from 3 expert orthopedic trauma surgeons for antegrade femoral intramedullary nailing. The written and audiovisual information was combined to describe the technical steps, decision points, and errors for each phase of this procedure Validation: A randomized double-blind controlled trial was undertaken with 22 medical students (novices) randomized into 2 equal groups. The intervention group were given the CTA tool and the control group were given a standard operative technique manual. They were assessed using the validated "Touch Surgery™" application assessment tool on femoral intramedullary nailing. Results - The pre-test scores between the two groups were similar. However, the post-test scores were statistically significantly better in the intervention group compared with the control group. The improvement (post-test median scores) in the intervention group compared with the control group was 20% for patient positioning and preparation, 21% for femoral preparation, 10% for proximal locking, and 19% for distal locking respectively (p < 0.001 for all comparisons). Interpretation - This is the first multimedia CTA tool in femoral intramedullary nailing that is easily accessible, user-friendly, and has demonstrated significant benefits in training novices over the traditional use of operative technique manuals

    The relation between ST-segment resolution and in-hospital mortality after primary percutaneous coronary interventions

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    Objective:&nbsp;The resolution of ST-segment elevation (&gt;50%) indicates successful reperfusion with thrombolytic therapy. The aim of this study is to evaluate the relation of ST-segment resolution post-primary percutaneous cardiac intervention (PCI) with in-hospital mortality and coronary thrombolysis in myocardial infarction (TIMI) blood flow.&nbsp;Methods:&nbsp;This study is a single-centred retrospective study. The study enrolled 100 patients who were referred to the Nasiriya Heart Centre for primary PCI. We measured the ST segment amplitude in the lead with the highest elevation prior to primary PCI and assessed the ST-segment elevation post-primary PCI. The ratio of ST-segment resolution was calculated and considered complete if reaches ≥70% from the initial ST-segment elevation. We assessed the association of ST-segment resolution with in-hospital mortality.&nbsp;Results:&nbsp;Analysis of the electrocardiogram (ECG) showed that 21 patients (21%) had complete ST-segment (≥ 70%) resolution. No significant association was shown between ST-segment resolution and in-hospital mortality. Two out of 21 patients with complete ST-segment resolution died in the hospital and 6 out of 79 patients with incomplete ST-segment resolution died (P=0.77). There is no significant association between ST-segment resolution and coronary TIMI flow grades. In patients with complete ST-segment resolution, 19 patients had TIMI III flow and 2 patients had TIMI II flow. In patients with incomplete ST-segment resolution, 72 patients had TIMI III flow, 6 patients had TIMI II flow; and 1 patient had no-reflow (P=0.84).&nbsp;Conclusion:&nbsp;Complete ST-segment resolution in post-primary PCI settings has no significant association with in-hospital mortality. Absent or incomplete ST-segment resolution is not necessarily an indicator of coronary artery re-occlusion after primary PCI

    Interpreting Arabic Sign Alphabet by using the Deep Learning

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    Sign Language (SL) is a communication method between people. It is an essential language; especially for people who are speech impaired and hearing impaired, it can be considered as their mother tongues. Hand gestures form the nonverbal communication of this language. We focus on interpreting Arabic Sign Alphabet (ASA) in this study and, as a case study, the recognition of alphabet in Iraqi Sign Language (IrSL) is carried out with the help of specialists from the “Al-Amal Institute for the Deaf and Dumb”. A new ASA dataset of various hand gestures was created and adopted. In addition, a deep learning model named the Deep Arabic Sign Alphabet (DASA) is proposed, which is a developed version of the Convolutional Neural Network (CNN). It can efficiently interpret the ASA, achieving a high interpretation accuracy of 95.25%

    Differential proteomic study of oil palm leaves in response to in vitro inoculation with pathogenic and non-pathogenic Ganoderma spp.

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    Basal stem rot is an aggressive disease in oil palm caused by Ganoderma species. The disease threatens the commercial oil palm plantations of South East Asia, especially in Malaysia. In order to understand the mechanism involved in the early stage of interaction between Ganoderma spp. and its host at systemic level, proteomic analysis of oil palm leaves was conducted on protein samples collected over 72 hours during inoculation with pathogenic Ganoderma boninense and non-pathogenic Ganoderma tornatum. A total of 82 proteins resolved during two-dimensional gel electrophoresis with significant differences in the spot abundance. However, only 24 differentially expressed proteins in response to Ganoderma spp. inoculations were successfully identified by mass spectrophotometry as compared to the non-inoculated control. These proteins are mainly involved in photosynthesis, signalling, stress/defense, energy and metabolism regulation. Changes in relative abundance of these proteins suggest an important role in disease susceptibility. Most proteins showed altered abundance in response to both G. boninense and G. tornatum, while some proteins were only affected by either G. boninense or G. tornatum. The putative role of the identified proteins in oil palm leaves during the interaction with both Ganoderma spp. is discussed

    The effect of blade angles of the vertical axis wind turbine on the output performance.

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    There are many social, political and environmental issues associated with the use of fossil fuels. For this reason, there are numerous investigations currently being carried out to develop newer and renewable sources of energy to alleviate energy demand. Wind is one source of energy that can be harnessed using wind turbines. In this study, numerical investigations using CFD analysis have been carried out to determine the optimum dimensions of a wind turbine used in urban environments by varying the rotor and stator blade angles. The effect of these blade angles have been considered to be within the normal operating range (α from 1.689 to 21.689 , δ from 22.357 to 42.357 and γ from 18.2 to 38.2 ) while β was kept constant to 90 . The results show that as α increase torque output and power output increases to a certain point after which both these quantities start decreasing. On the contrary to α, as δ increase torque output and power output decreases. From the results it can be concluded that the ideal blade angles, for optimal power output, are α=16.689, γ=18.2 and δ=22.357

    Paper and electronic versions of HM-PRO, a novel patient-reported outcome measure for hematology: an equivalence study.

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    © 2019 Goswami, Oliva, Ionova et al.Aim:To determine measurement equivalence of paper and electronic application of the hematologi-cal malignancy-patient-reported outcome (HM-PRO), a specific measure for the evaluation of patient-reported outcomes in HMs.Patients & methods:Following International Society of Pharmacoeconomicsand Outcomes Research ePRO Good Research Practice Task Force guidelines, a total of 193 adult patientswith different HMs were recruited into a multicenter prospective study. The paper and the electronic ver-sion of the instrument were completed in the outpatient clinics in a randomized crossover design with a30-min time interval to minimize the learning effect. Those who completed the paper version first, com-pleted the electronic version after 30 min and vice versa. Instrument version and order effects were testedon total score of the two parts of the HM-PRO (Part A: quality of life and Part B: signs & symptoms) in atwo-way ANOVA with patients as random effects. Intraclass correlation coefficients (95% CI) and Spear-man’s rank correlation coefficients were used to evaluate test–retest reliability and reproducibility. Theeffects of instrument version and order were tested on total score of the two parts of HM-PRO.Results:The questionnaire version and administration order effects were not significant at the 5% level. Therewere no interactions found between these two factors for HM-PRO (Part A [quality of life]; p=0.95); and(part B [signs and symptoms]; p=0.72]. Spearman’s rank correlation coefficients were greater than 0.9, andintraclass correlation coefficients ranged from 0.94 to 0.98; furthermore, the scores were not statisticallydifferent between the two versions, showing acceptable reliability indexes. Noteworthy, the differencebetween the completion time for both paper (mean=6:38 min) and electronic version (mean=7:29 min)was not statistically significant (n=100; p=0.11). Patients did not report any difficulty in completing theelectronic version during cognitive interviews and were able to understand and respond spontaneously.Conclusion:Measurement equivalence has been demonstrated for the paper and electronic applicationof the HM-PRO.Peer reviewe

    Crack healing under sustained load in concrete: An experimental/numerical study

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    The need of sustainable resilient structures and infrastructures push towards the use of cementitious materials able to heal micro-cracks and defects. For real structural application under service loading the time-dependent behavior is of the utmost importance, especially in presence of cracks which can lead to a nonlinear creep behavior that might cause the structural failure. Now the new challenge is to study and quantify the effect of crack-healing on the nonlinear creep behavior. This study aims at the following goals: 1) to characterize with experimental investigations the effect of the healing in tests in which the specimens, along the exposure time and under controlled environmental conditions, are under sustained load, the expected service load, determined as a fraction of the pre-cracking load; 2) develop a comprehensive numerical framework for the interpretation and simulation of the experimentally observed results. To this purpose an experimental investigation is currently ongoing at Politecnico di Milano with reference to an Ultra High-Performance Concrete developed in the framework of the H2020 ReSHEALience project for exposure to extremely aggressive environments. The numerical framework is based on the recent developments of the multiphysics lattice particle model
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