328 research outputs found

    Respiratory motion correction in dynamic MRI using robust data decomposition registration - Application to DCE-MRI.

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    Motion correction in Dynamic Contrast Enhanced (DCE-) MRI is challenging because rapid intensity changes can compromise common (intensity based) registration algorithms. In this study we introduce a novel registration technique based on robust principal component analysis (RPCA) to decompose a given time-series into a low rank and a sparse component. This allows robust separation of motion components that can be registered, from intensity variations that are left unchanged. This Robust Data Decomposition Registration (RDDR) is demonstrated on both simulated and a wide range of clinical data. Robustness to different types of motion and breathing choices during acquisition is demonstrated for a variety of imaged organs including liver, small bowel and prostate. The analysis of clinically relevant regions of interest showed both a decrease of error (15-62% reduction following registration) in tissue time-intensity curves and improved areas under the curve (AUC60) at early enhancement

    Study of Structural and Optical Properties of FeS2 Nanoparticles Prepared by Polyol Method

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    FeS2 nanoparticles were prepared using a simple and cost-effective Polyol method with ethylene glycol and precursor thiourea as capping reagents. The crystalline structure of FeS2 nanoparticles were confirmed by X-ray diffraction. Dimensions of the unit cell and Pa-3 space group were determined by Rietveld refinement. The average crystallite size was found to be ~ 42.1 nm. The stoichiometry of these nanoparticles were also confirmed by, Raman and Fourier Transform Infrared Spectroscopy. Further, Raman spectroscopy revealed the chemical bonding and symmetry of molecules. FTIR spectroscopy exhibited the presence of functional groups of Fe=S, Fe–S and S–S in the samples. Advanced measurements and analysis towards the applicability of surfactant coated pyrite FeS2 nanoparticles for solar cell etc. applications are in progress

    Evaluation of Multiple Salinity Tolerance Indices for Screening and Comparative Biochemical and Molecular Analysis of Pearl Millet [Pennisetum glaucum (L.) R. Br.] Genotypes

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    Salinity is a major constraint for plant growth, development and yield worldwide. Evaluation of a large number of germplasms in salt-stressed environments may help identify superior salt-tolerant genotypes. The present study dissects the genetic diversity of 33 pearl millet genotypes (landraces and inbred lines) for salinity tolerance through in vitro screening at the seedling stage. Our results revealed a significant reduction in total biomass and shoot growth of the salt-sensitive genotypes upon exposure to 150 mM NaCl, in contrast to the tolerant genotypes showing better growth characteristics. A significant differential effect of salt treatment on morphological traits was observed by analysis of variance (ANOVA), confirming substantial genetic diversity among all genotypes for salt tolerance. The genotypes were clustered into three groups based on multiple stress indices. The genotypes were also evaluated using principal component analysis (PCA) to identify the key contributing traits for stress tolerance. Based on these results, a total of four contrasting genotypes were selected for further biochemical and molecular analysis. Physiological studies confirmed that salt tolerance might be due to the higher content of osmolytes and the activity of antioxidant enzymes. Similarly, gene expression profiling of catalase (CAT), glutamate dehydrogenase (GDH), glutathione reductase (GR), and nitrate reductase (NR) revealed a profound increase in NR and GDH transcript levels in the tolerant genotypes, suggesting their major role as reactive oxygen species (ROS) scavengers under salinity. The overall findings of this study could be utilized further for candidate gene mining through “omics” approaches, aiming toward development of salinity resilient crop plants

    Multiparametric MR characterisation of a high-fat, high-cholesterol diet rodent model of liver disease

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    There is a growing interest in the development of new animal models of non-alcoholic fatty liver disease. In this study, we use T1, proton density fat fraction (PDFF) and R2* mapping to characterise hepatic parenchymal tissue and the evolution of MR properties over time in a high-fat, high-cholesterol diet model of fatty liver disease

    Current Applications and Future Development of Magnetic Resonance Fingerprinting in Diagnosis, Characterization, and Response Monitoring in Cancer

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    Magnetic resonance imaging (MRI) has enabled non-invasive cancer diagnosis, monitoring, and management in common clinical settings. However, inadequate quantitative analyses in MRI continue to limit its full potential and these often have an impact on clinicians' judgments. Magnetic resonance fingerprinting (MRF) has recently been introduced to acquire multiple quantitative parameters simultaneously in a reasonable timeframe. Initial retrospective studies have demonstrated the feasibility of using MRF for various cancer characterizations. Further trials with larger cohorts are still needed to explore the repeatability and reproducibility of the data acquired by MRF. At the moment, technical difficulties such as undesirable processing time or lack of motion robustness are limiting further implementations of MRF in clinical oncology. This review summarises the latest findings and technology developments for the use of MRF in cancer management and suggests possible future implications of MRF in characterizing tumour heterogeneity and response assessment

    VEROnA Protocol: A Pilot, Open-Label, Single-Arm, Phase 0, Window-of-Opportunity Study of Vandetanib-Eluting Radiopaque Embolic Beads (BTG-002814) in Patients With Resectable Liver Malignancies

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    BACKGROUND: Transarterial chemoembolization (TACE) is the current standard of care for patients with intermediate-stage hepatocellular carcinoma (HCC) and is also a treatment option for patients with liver metastases from colorectal cancer. However, TACE is not a curative treatment, and tumor progression occurs in more than half of the patients treated. Despite advances and technical refinements of TACE, including the introduction of drug-eluting beads-TACE, the clinical efficacy of TACE has not been optimized, and improved arterial therapies are required. OBJECTIVE: The primary objectives of the VEROnA study are to evaluate the safety and tolerability of vandetanib-eluting radiopaque embolic beads (BTG-002814) in patients with resectable liver malignancies and to determine concentrations of vandetanib and the N-desmethyl metabolite in plasma and resected liver following treatment with BTG-002814. METHODS: The VEROnA study is a first-in-human, open-label, single-arm, phase 0, window-of-opportunity study of BTG-002814 (containing 100 mg vandetanib) delivered transarterially, 7 to 21 days before surgery in patients with resectable liver malignancies. Eligible patients have a diagnosis of colorectal liver metastases, or HCC (Childs Pugh A), diagnosed histologically or radiologically, and are candidates for liver surgery. All patients are followed up for 28 days following surgery. Secondary objectives of this study are to evaluate the anatomical distribution of BTG-002814 on noncontrast-enhanced imaging, to evaluate histopathological features in the surgical specimen, and to assess changes in blood flow on dynamic contrast-enhanced magnetic resonance imaging following treatment with BTG-002814. Exploratory objectives of this study are to study blood biomarkers with the potential to identify patients likely to respond to treatment and to correlate the distribution of BTG-002814 on imaging with pathology by 3-dimensional modeling. RESULTS: Enrollment for the study was completed in February 2019. Results of a planned interim analysis were reviewed by a safety committee after the first 3 patients completed follow-up. The recommendation of the committee was to continue the study without any changes to the dose or trial design, as there were no significant unexpected toxicities related to BTG-002814. CONCLUSIONS: The VEROnA study is studying the feasibility of administering BTG-002814 to optimize the use of this novel technology as liver-directed therapy for patients with primary and secondary liver cancer. TRIAL REGISTRATION: ClinicalTrial.gov NCT03291379; https://clinicaltrials.gov/ct2/show/NCT03291379. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/13696

    Infection, colonization and shedding of Campylobacter and Salmonella in animals and their contribution to human disease: A review

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    Livestock meat and offal contribute significantly to human nutrition as sources of high‐quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low‐ and middle‐income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource‐poor settings

    Harnessing Infrared Photons for Photoelectrochemical Hydrogen Generation. A PbS Quantum Dot Based "Quasi-Artificial Leaf"

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    [EN] Hydrogen generation by using quantum dot (QD) based heterostructures has emerged as a promising strategy to develop artificial photosynthesis devices. In the present study, we sensitize mesoporous TiO2 electrodes with in-situ-deposited PbS/CdS QDs, aiming at harvesting light in both the visible and the near-infrared for hydrogen generation. This heterostructure exhibits a remarkable photocurrent of 6 mA.cm(-2), leading to 60 mL.cm(-2).day(-1) hydrogen generation. Most importantly, confirmation of the contribution of infrared photons to H-2 generation was provided by the incident-photon-to-current-efficiency (IPCE), and the integrated current was in excellent agreement with that obtained through cyclic voltammetry. The main electronic processes (accumulation, transport, and recombination) were identified by impedance spectroscopy, which appears as a simple and reliable methodology to evaluate the limiting factors of these photoelectrodes. On the basis of this TiO2/PbS/CdS heterostructrure, a "quasi-artificial leaf' has been developed, which has proven to produce hydrogen under simulated solar illumination at (4.30 +/- 0.25) mL.cm(-2).day(-1).We acknowledge support by projects from Ministerio de Economia y Competitividad (MINECO) of Spain (Consolider HOPE CSD2007-00007, MAT2010-19827), Generalitat Valenciana (PROMETEO/2009/058 and Project ISIC/2012/008 "Institute of Nanotechnologies for Clean Energies"), and Fundacio Bancaixa (P1.1B2011-50). S.G. acknowledges support by MINECO of Spain under the Ramon y Cajal programme. The SCIC of the University Jaume I de Castello is also acknowledged for the gas analysis measurements. C.S. acknowledges the POSDRU/89/1.5/S/58852 Project "Postdoctoral programme for training scientific researchers", co-financed by the European Social Fund within the Sectorial Operational Program Human Resources Development 2007-2013. We want to acknowledge Prof. J. Bisquert for the fruitful discussions related to this manuscript.Trevisan, R.; Rodenas, P.; González-Pedro, V.; Sima, C.; Sánchez, RS.; Barea, EM.; Mora-Sero, I.... (2013). Harnessing Infrared Photons for Photoelectrochemical Hydrogen Generation. A PbS Quantum Dot Based "Quasi-Artificial Leaf". Journal of Physical Chemistry Letters. 4(1):141-146. https://doi.org/10.1021/jz301890mS1411464
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