420 research outputs found

    Мовні реалії іншого часу і простору (про особливості слововживання у творах Івана Багряного)

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    The structure of Earthʼs deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core. Using an extensive new data set of handpicked absolute travel time observations of the inner core phase PKIKP, we find that the data are best explained by variations in anisotropy between two hemispheres and do not require an innermost inner core. We demonstrate that observations of an innermost inner core are an artifact from averaging over lateral anisotropy variations. More significantly we show that hemispherical variations in anisotropy, previously only imaged in the upper inner core, continue to its centre. The eastern region has 0.5–1.5% anisotropy, whereas the western region has 3.5–8.8% anisotropy increasing with depth, with a slow direction at 57–61° to the Earthʼs rotation axis at all depths. Such anisotropy is consistent with models of aligned hcp or bcc iron aggregates

    Oncologist-led BRCA ‘mainstreaming’ in the ovarian cancer clinic: A study of 255 patients and its impact on their management

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    Although guidelines recommend BRCA testing for all women with non-mucinous epithelial ovarian cancer, there is significant variability in access to testing across the UK. A germline BRCA mutation (BRCAm) in ovarian cancer patients provides prognostic and predictive information and influences clinical management, such as the use of PARP inhibitors, which have demonstrated a progression-free survival benefit in the BRCAm cohort. Additionally, the finding of a BRCAm has significant implications for patients and their families in terms of cancer risk and prevention. We studied the impact of a newly-formed, oncologist-led ‘mainstreaming’ germline BRCA testing pathway in 255 ovarian cancer patients at Imperial College NHS Trust. Prior to the establishment of ‘mainstreaming’, uptake of germline BRCA testing was 14% with a mean turnaround time of 148.2 calendar days. The ‘mainstreaming’ approach led to a 95% uptake of germline BRCA testing and a mean turnaround time of 20.6 days. Thirty-four (13.33%) BRCAm patients were identified. At the time of data collection nine BRCAm patients had received a PARP inhibitor off-trial, three had entered a PARP inhibitor trial and 5 were receiving platinum-based chemotherapy with a plan to receive PARP inhibitor maintenance. This study provides further evidence of the impact of oncologist-led ‘mainstreaming’ programs

    External validation of the fatty liver index and lipid accumulation product indices, using H-1-magnetic resonance spectroscopy, to identify hepatic steatosis in healthy controls and obese, insulin-resistant individuals

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    Background and Aims. Simple clinical algorithms including the Fatty Liver Index (FLI) and Lipid Accumulation Product (LAP) have been developed as a surrogate marker for Non-Alcoholic Fatty Liver Disease (NAFLD). These algorithms have been constructed using ultrasonography, a semi-quantitative method. This study aimed to validate FLI and LAP as measures of hepatic steatosis, as measured quantitatively by proton magnetic resonance spectroscopy (1H-MRS). Methods. Data were collected from 168 patients with NAFLD and 168 controls who had undergone clinical, biochemical and anthropometric assessment in the course of research studies. Values of FLI and LAP were determined, and assessed both as predictors of the presence of hepatic steatosis (liver fat >5.5 %) and of actual liver fat content, as measured by 1H MRS. The discriminative ability of FLI and LAP was estimated using the area under the Receiver Operator Characteristic curve (AUROC). Since FLI can also be interpreted as a predictive probability of hepatic steatosis, we assessed how well calibrated it was in our cohort. Linear regression with prediction intervals was used to assess the ability of FLI and LAP to predict liver fat content. Results. FLI and LAP discriminated between patients with and without hepatic steatosis with an AUROC of 0.79 (IQR= 0.74, 0.84) and 0.78 (IQR= 0.72, 0.83), although quantitative prediction of liver fat content was unsuccessful. Additionally, the algorithms accurately matched the observed percentages of patients with hepatic steatosis in our cohort. Conclusions. FLI and LAP may be used clinically, and for metabolic and epidemiological research, to identify patients with hepatic steatosis, but not as surrogates for liver fat content

    Novel exomphalos genetic mouse model: The importance of accurate phenotypic classification.

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    Rodent models of abdominal wall defects (AWD) may provide insight into the pathophysiology of these conditions including gut dysfunction in gastroschisis, or pulmonary hypoplasia in exomphalos. Previously, a Scribble mutant mouse model (circletail) was reported to exhibit gastroschisis. We further characterise this AWD in Scribble knockout mice

    Multi-modal imaging probe for assessing the efficiency of stem cell delivery to orthotopic breast tumours

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    Stem cells have been utilised as anti-cancer agents due to their ability to home to and integrate within tumours. Methods to augment stem cell homing to tumours are being investigated with the goal of enhancing treatment efficacy. However, it is currently not possible to evaluate both cell localisation and cell viability after engraftment, hindering optimisation of therapy. In this study, luciferase-expressing human adipocyte-derived stem cells (ADSCs) were incubated with Indium-111 radiolabelled iron oxide nanoparticles to produce cells with tri-modal imaging capabilities. ADSCs were administered intravenously (IV) or intracardially (IC) to mice bearing orthotopic breast tumours. Cell fate was monitored using bioluminescence imaging (BLI) as a measure of cell viability, magnetic resonance imaging (MRI) for cell localisation and single photon emission computer tomography (SPECT) for cell quantification. Serial monitoring with multi-modal imaging showed the presence of viable ADSCs within tumours as early as 1-hour post IC injection and the percentage of ADSCs within tumours to be 2-fold higher after IC than IV. Finally, histological analysis was used to validate engraftment of ADSC within tumour tissue. These findings demonstrate that multi-modal imaging can be used to evaluate the efficiency of stem cell delivery to tumours and that IC cell administration is more effective for tumour targeting

    Coordination chemistry of amide-functionalised tetraazamacrocycles: structural, relaxometric and cytotoxicity studies

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    Three different tetraazamacrocyclic ligands containing four amide substituents that feature groups (namely allyl, styryl and propargyl groups) suitable for polymerisation have been synthesised. Gadolinium(III) complexes of these three ligands have been prepared as potential monomers for the synthesis of polymeric MRI contrast agents. To assess the potential of these monomers as MRI contrast agents, their relaxation enhancement properties and cytotoxicity have been determined. A europium(III) complex of one of these ligands (with propargyl substituents) is also presented together with its PARACEST properties. In addition, to gain further insight into the coordination chemistry of the tetra-propargyl substituted ligand, the corresponding zinc(II) and cadmium(II) complexes have been prepared. The X-ray crystal structures of the tetra-propargyl ligand and its corresponding gadolinium(III), zinc(II) and cadmium(II) complexes are also presented

    Multi Atlas Segmentation applied to in vivo mouse brain MRI

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    Multi-atlas segmentation propagation has evolved quickly in recent years, becoming a state-of-the-art method for automatic struc- tural parcellation for brain MRI. However, few studies have applied these methods to preclinical research. In this study, we present a fully auto- matic multi-atlas segmentation pipeline for mouse brain MRI tissue par- cellation. The pipeline adopts the Multi-STEPS multi-atlas segmentation algorithm, which utilises a locally normalised cross correlation (LNCC) similarity metric for atlas selection and an extended STAPLE frame- work for multi-label fusion. The segmentation accuracy of the pipeline was evaluated using an in vivo mouse brain atlas with pre-segmented manual labels as gold standard, and optimised parameters were obtained. Results show a mean Dice similarity coefficient of 0.839 over all the struc- tures and for all the samples in the database, significantly higher than in a single atlas propagation strategy, and also generally higher than STAPLE strategy, although the improvement is not significant
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