130,809 research outputs found
Anatomical and microstructural imaging of angiogenesis
No full textThis article reviews and discusses different options for visualizing the microarchitecture of vessels ex vivo and in vivo with respect to reliability, practicability and availability. The investigation of angiogenesis by standard histological methods, like microvessel density counts, is limited since the three-dimensional (3-D) architecture and the functionality of vessels cannot be considered properly. Coregistration of immunostained images of vessels may be performed but is time consuming and often not sufficiently accurate. Confocal fluorescence microscopy is an alternative, but only enables 3-D stacks of less than 500 nm in thickness. Multiphoton microscopy and other advanced technologies, such as optical coherence tomography and optical frequency domain imaging, provide a deeper view into tissues and allow for in vivo imaging of microvessels, which is a precondition for longitudinal studies. Besides these microscopic techniques, the vascularization in larger tissue samples can be investigated using corrosion casts in combination with scanning electron microscopy, or microcomputed tomography (A mu CT). Furthermore, recent improvements in A mu CT technology open up new perspectives for in vivo scans with high resolution and tolerable X-ray doses. Also 3-D contrast-enhanced high-frequency ultrasound has been shown to be sensitive for angiogenic vessels and even distinguishing between mature and immature vessels appears feasible. Microvessel architecture can also be visualized by MRI. Here, T1-weighted angiography techniques after injection of blood pool contrast agents appear preferable. Optoacoustic tomographic imaging has more recently shown promise for high-resolution in vivo mapping of the microvasculature in rodents using intrinsic haemoglobin-based contrast and exogenous contrast agents
pyruct
No full textPython Package for Reflection Ultrasound Computed Tomography (RUCT) Delay And Sum (DAS) Algorithm
If you use this data in your research, please cite the following paper:
B. Lafci, J. Robin, X. L. Deán-Ben and D. Razansky, "Expediting Image Acquisition in Reflection Ultrasound Computed Tomography," in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, doi: 10.1109/TUFFC.2022.3172713.This project is supported by Swiss Data Science Center (SDSC) grant C19-04
Reflection Ultrasound Computed Tomography (RUCT) Phantom Data
No full textTest Data for Reflection Ultrasound Computed Tomography (RUCT) Delay and Sum Algorithm
This data is shared for "pyruct" package tests. "pyruct" package can be found in "https://github.com/berkanlafci/pyruct"
If you use this data in your research, please cite the following paper:
B. Lafci, J. Robin, X. L. Deán-Ben and D. Razansky, "Expediting Image Acquisition in Reflection Ultrasound Computed Tomography," in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, doi: 10.1109/TUFFC.2022.3172713.This project is supported by Swiss Data Science Center (SDSC) grant C19-04
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Reflection Ultrasound Computed Tomography (RUCT) Data
No full textData for Reflection Ultrasound Computed Tomography (RUCT) Delay and Sum Algorithm
Data is shared for "pyruct" package tests and as supporting files of the research article indicated below.
"pyruct" package can be found in "https://github.com/berkanlafci/pyruct"
If you use this data in your research, please cite the following paper:
B. Lafci, J. Robin, X. L. Deán-Ben and D. Razansky, "Expediting Image Acquisition in Reflection Ultrasound Computed Tomography," in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, doi: 10.1109/TUFFC.2022.3172713.
"nct" means number of consecutive transducer elements used in transmission event. Please use the files with "nct_1" tags for the full acquisition and reconstruction.This project is supported by Swiss Data Science Center (SDSC) grant C19-04
Towards a compact, high-speed optical linkbased 3D optoacoustic imager
No full textWe demonstrate the feasibility of a compact real-time 3D optoacoustic (OA) imager employing a novel low-cost software-defined ultrasound digital acquisition platform. It supports simultaneous signal acquisition from up to 192 ultrasound channels and a direct optical link (2x 100G Ethernet) to the host-PC for high-frame-rate image acquisitions. Real-time 3D imaging experiments with light-absorbing phantoms and the wrist of a healthy volunteer are reported. These results pave the way toward a new generation of compact, affordable, and flexible hand-held OA scanners
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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