133 research outputs found
In conversation with Naser Faruqui : a next generation water leader
French version available in IDRC Digital Library: Entretien avec Naser Faruqui : un futur chef de file de la gestion de l'ea
Entretien avec Naser Faruqui : un futur "chef de file de la gestion de l'eau"
Version anglaise disponible dans la Bibliothèque numérique du CRDI: In conversation with Naser Faruqui : a next generation water leade
Concordance between a neuroradiologist, a consultant radiologist and trained reporting radiographers interpreting MRI head examinations: An empirical study
Introduction: This study assessed agreement between MRI reporting radiographers and a consultant radiologist compared with an index neuroradiologist when reporting MRI head (brain/internal auditory meati [IAMs]) examinations. The effect on patient management of any discordant reports was also examined.
Methods: Two trained MRI reporting radiographers (RRs), a consultant radiologist (CR) and an index neuroradiologist (INR) reported on a random sample of 210 MRI examinations. The radiographers reported during clinical practice and the radiologists in clinical practice conditions. Two independent consultant physicians (neuro-rehabilitation and neuropsychiatry) compared these reports with the index neuroradiologist report for agreement and the clinical importance of discrepant reports.
Results: Overall observer agreement between the RRs and CR was comparable in relation to agreement with the INR: RR; 93/210 (44.3%); and the CR; 83/210 (39.4%) for all head MRI examinations (p = 0.32). For brain examinations the difference was similar: RR; 64/180 (35.6%); and CR; 54/190 (30.0%), p = 0.26. Agreement rates for the IAMs examinations were identical, 29/30 (97.7%). For all head MRI examinations (n = 210) there was a very small observed difference of <0.5% in mean agreement between the reporting radiographers and the consultant radiologist (p = 0.92) for examinations where a major disagreement would have been likely to have led to a change in patient management.
Conclusion: MRI reporting radiographers reported during clinical practice on MRI head examinations to a level of agreement comparable with a consultant radiologist.
Implications for practice: This is an area in which radiographers could provide additional reporting roles to the reporting service to increase capacity. Wider potential benefits include cost-effectiveness and role development/retention of radiographers
Antimicrobial peptide capsids of de novo design
The spread of bacterial resistance to antibiotics poses the need for antimicrobial discovery. With traditional search paradigms being exhausted, approaches that are altogether different from antibiotics may offer promising and creative solutions. Here, we introduce a de novo peptide topology that-by emulating the virus architecture-assembles into discrete antimicrobial capsids. Using the combination of high-resolution and real-time imaging, we demonstrate that these artificial capsids assemble as 20-nm hollow shells that attack bacterial membranes and upon landing on phospholipid bilayers instantaneously (seconds) convert into rapidly expanding pores causing membrane lysis (minutes). The designed capsids show broad antimicrobial activities, thus executing one primary function-they destroy bacteria on contact
Psychiatric rating scales in Urdu: a systematic review
<p>Abstract</p> <p>Background</p> <p>Researchers setting out to conduct research employing questionnaires in non-English speaking populations need instruments that have been validated in the indigenous languages. In this study we have tried to review the literature on the status of cross-cultural and/or criterion validity of all the questionnaires measuring psychiatric symptoms available in Urdu language.</p> <p>Methods</p> <p>A search of Medline, Embase, PsycINFO and <url>http://www.pakmedinet.com</url> was conducted using the search terms; Urdu psychiatric rating scale, and Urdu and Psychiatry. References of retrieved articles were searched. Only studies describing either cross-cultural or criterion validation of a questionnaire in Urdu measuring psychiatric symptoms were included.</p> <p>Results</p> <p>Thirty two studies describing validation of 19 questionnaires were identified. Six of these questionnaires were developed indigenously in Urdu while thirteen had been translated from English. Of the six indigenous questionnaires five had had their criterion validity examined. Of the thirteen translated questionnaires only four had had both their cross-cultural and criterion validity assessed.</p> <p>Conclusion</p> <p>There is a paucity of validated questionnaires assessing psychiatric symptoms in Urdu. The BSI, SRQ and AKUADS are the questionnaires that have been most thoroughly evaluated in Urdu.</p
Nano-mechanical single-cell sensing of cell-matrix contacts
Extracellular protein matrices provide a rigidity interface exhibiting nano-mechanical cues that guide cell growth and proliferation. Cells sense such cues using actin-rich filopodia extensions which encourage favourable cell–matrix contacts to recruit more actin-mediated local forces into forming stable focal adhesions. A challenge remains in identifying and measuring these local cellular forces and in establishing empirical relationships between them, cell adhesion and filopodia formation. Here we investigate such relationships using a micromanipulation system designed to operate at the time scale of focal contact dynamics, with the sample frequency of a force probe being 0.1 ms, and to apply and measure forces at nano-to-micro Newton ranges for individual mammalian cells. We explore correlations between cell biomechanics, cell–matrix attachment forces and the spread areas of adhered cells as well as their relative dependence on filopodia formation using synthetic protein matrices with a proven ability to induce enhanced filopodia numbers in adherent cells. This study offers a basis for engineering exploitable cell–matrix contacts in situ at the nanoscale and single-cell levels
Robust Single-view Cone-beam X-ray Pose Estimation with Neural Tuned Tomography (NeTT) and Masked Neural Radiance Fields (mNeRF)
Many tasks performed in image-guided, mini-invasive, medical procedures can
be cast as pose estimation problems, where an X-ray projection is utilized to
reach a target in 3D space. Expanding on recent advances in the differentiable
rendering of optically reflective materials, we introduce new methods for pose
estimation of radiolucent objects using X-ray projections, and we demonstrate
the critical role of optimal view synthesis in performing this task. We first
develop an algorithm (DiffDRR) that efficiently computes Digitally
Reconstructed Radiographs (DRRs) and leverages automatic differentiation within
TensorFlow. Pose estimation is performed by iterative gradient descent using a
loss function that quantifies the similarity of the DRR synthesized from a
randomly initialized pose and the true fluoroscopic image at the target pose.
We propose two novel methods for high-fidelity view synthesis, Neural Tuned
Tomography (NeTT) and masked Neural Radiance Fields (mNeRF). Both methods rely
on classic Cone-Beam Computerized Tomography (CBCT); NeTT directly optimizes
the CBCT densities, while the non-zero values of mNeRF are constrained by a 3D
mask of the anatomic region segmented from CBCT. We demonstrate that both NeTT
and mNeRF distinctly improve pose estimation within our framework. By defining
a successful pose estimate to be a 3D angle error of less than 3 deg, we find
that NeTT and mNeRF can achieve similar results, both with overall success
rates more than 93%. However, the computational cost of NeTT is significantly
lower than mNeRF in both training and pose estimation. Furthermore, we show
that a NeTT trained for a single subject can generalize to synthesize
high-fidelity DRRs and ensure robust pose estimations for all other subjects.
Therefore, we suggest that NeTT is an attractive option for robust pose
estimation using fluoroscopic projections
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