349 research outputs found

    Development of Multigene Expression Signature Maps at the Protein Level from Digitized Immunohistochemistry Slides

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    Molecular classification of diseases based on multigene expression signatures is increasingly used for diagnosis, prognosis, and prediction of response to therapy. Immunohistochemistry (IHC) is an optimal method for validating expression signatures obtained using high-throughput genomics techniques since IHC allows a pathologist to examine gene expression at the protein level within the context of histologically interpretable tissue sections. Additionally, validated IHC assays may be readily implemented as clinical tests since IHC is performed on routinely processed clinical tissue samples. However, methods have not been available for automated n-gene expression profiling at the protein level using IHC data. We have developed methods to compute expression level maps (signature maps) of multiple genes from IHC data digitized on a commercial whole slide imaging system. Areas of cancer for these expression level maps are defined by a pathologist on adjacent, co-registered H&E slides, allowing assessment of IHC statistics and heterogeneity within the diseased tissue. This novel way of representing multiple IHC assays as signature maps will allow the development of n-gene expression profiling databases in three dimensions throughout virtual whole organ reconstructions

    7 T renal MRI: challenges and promises

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    The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging

    Quantitative comparison of immunohistochemical staining measured by digital image analysis versus pathologist visual scoring

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    <p>Abstract</p> <p>Immunohistochemical (IHC) assays performed on formalin-fixed paraffin-embedded (FFPE) tissue sections traditionally have been semi-quantified by pathologist visual scoring of staining. IHC is useful for validating biomarkers discovered through genomics methods as large clinical repositories of FFPE specimens support the construction of tissue microarrays (TMAs) for high throughput studies. Due to the ubiquitous availability of IHC techniques in clinical laboratories, validated IHC biomarkers may be translated readily into clinical use. However, the method of pathologist semi-quantification is costly, inherently subjective, and produces ordinal rather than continuous variable data. Computer-aided analysis of digitized whole slide images may overcome these limitations. Using TMAs representing 215 ovarian serous carcinoma specimens stained for S100A1, we assessed the degree to which data obtained using computer-aided methods correlated with data obtained by pathologist visual scoring. To evaluate computer-aided image classification, IHC staining within pathologist annotated and software-classified areas of carcinoma were compared for each case. Two metrics for IHC staining were used: the percentage of carcinoma with S100A1 staining (%Pos), and the product of the staining intensity (optical density [OD] of staining) multiplied by the percentage of carcinoma with S100A1 staining (OD*%Pos). A comparison of the IHC staining data obtained from manual annotations and software-derived annotations showed strong agreement, indicating that software efficiently classifies carcinomatous areas within IHC slide images. Comparisons of IHC intensity data derived using pixel analysis software versus pathologist visual scoring demonstrated high Spearman correlations of 0.88 for %Pos (p < 0.0001) and 0.90 for OD*%Pos (p < 0.0001). This study demonstrated that computer-aided methods to classify image areas of interest (e.g., carcinomatous areas of tissue specimens) and quantify IHC staining intensity within those areas can produce highly similar data to visual evaluation by a pathologist.</p> <p>Virtual slides</p> <p>The virtual slide(s) for this article can be found here: <url>http://www.diagnosticpathology.diagnomx.eu/vs/1649068103671302</url></p

    Late-time observations of the relativistic tidal disruption flare candidate Swift J1112.2-8238

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    We present late-time follow-up of the relativistic tidal disruption flare candidate Swift J1112.2- 8238. We confirm the previously determined redshift of z = 0.8900±0.0005 based on multiple emission line detections. HST imaging of the host galaxy indicates a complex and distorted morphology with at least two spatially distinct components. These are offset in velocity space by less than 350 km s−1 in VLT/X-Shooter observations, suggesting that the host is undergoing interaction with another galaxy. The transient position is consistent to 2.2σ with the centre of a bulge-like component at a distance of 1.1±0.5kpc from its centre. Luminous, likely variable radio emission has also been observed, strengthening the similarities between Swift J1112.2-8238 and other previously identified relativistic tidal disruption flares. While the transient location is ∼2σ from the host centroid, the disrupted nature of the host may provide an explanation for this. The tidal disruption model remains a good description for these events

    Some remarks on the size of bodies and black holes

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    We consider the application of stable marginally outer trapped surfaces to problems concerning the size of material bodies and the area of black holes. The results presented extend to general initial data sets (V,g,K) previous results assuming either maximal (tr K = 0) or time-symmetric (K = 0) initial data.Comment: 12 page

    A Detailed Observational Analysis of V1324 Sco, the Most Gamma-Ray Luminous Classical Nova to Date

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    It has recently been discovered that some, if not all, classical novae emit GeV gamma rays during outburst, but the mechanisms involved in the production of the gamma rays are still not well understood. We present here a comprehensive multi-wavelength dataset---from radio to X-rays---for the most gamma-ray luminous classical nova to-date, V1324 Sco. Using this dataset, we show that V1324 Sco is a canonical dusty Fe-II type nova, with a maximum ejecta velocity of 2600 km s1^{-1} and an ejecta mass of few ×105\times 10^{-5} M_{\odot}. There is also evidence for complex shock interactions, including a double-peaked radio light curve which shows high brightness temperatures at early times. To explore why V1324~Sco was so gamma-ray luminous, we present a model of the nova ejecta featuring strong internal shocks, and find that higher gamma-ray luminosities result from higher ejecta velocities and/or mass-loss rates. Comparison of V1324~Sco with other gamma-ray detected novae does not show clear signatures of either, and we conclude that a larger sample of similarly well-observed novae is needed to understand the origin and variation of gamma rays in novae.Comment: 26 pages, 13 figure

    Developing Telemental Health Partnerships Between State Medical Schools and Federally Qualified Health Centers: Navigating the Regulatory Landscape and Policy Recommendations

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    BackgroundFederally Qualified Health Centers (FQHCs) deliver care to 26 million Americans living in underserved areas, but few offer telemental health (TMH) services. The social missions of FQHCs and publicly funded state medical schools create a compelling argument for the development of TMH partnerships. In this paper, we share our experience and recommendations from launching TMH partnerships between 12 rural FQHCs and 3 state medical schools.ExperienceThere was consensus that medical school TMH providers should practice as part of the FQHC team to promote integration, enhance quality and safety, and ensure financial sustainability. For TMH providers to practice and bill as FQHC providers, the following issues must be addressed: (1) credentialing and privileging the TMH providers at the FQHC, (2) expanding FQHC Scope of Project to include telepsychiatry, (3) remote access to medical records, (4) insurance credentialing/paneling, billing, and supplemental payments, (5) contracting with the medical school, and (6) indemnity coverage for TMH.RecommendationsWe make recommendations to both state medical schools and FQHCs about how to overcome existing barriers to TMH partnerships. We also make recommendations about changes to policy that would mitigate the impact of these barriers. Specifically, we make recommendations to the Centers for Medicare and Medicaid about insurance credentialing, facility fees, eligibility of TMH encounters for supplemental payments, and Medicare eligibility rules for TMH billing by FQHCs. We also make recommendations to the Health Resources and Services Administration about restrictions on adding telepsychiatry to the FQHCsâ Scope of Project and the eligibility of TMH providers for indemnity coverage under the Federal Tort Claims Act.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/1/jrh12323_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/2/jrh12323.pd

    The 2020 photovoltaic technologies roadmap

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    Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years
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