Uniform electron gases

We show that the traditional concept of the uniform electron gas (UEG) --- a homogeneous system of finite density, consisting of an infinite number of electrons in an infinite volume --- is inadequate to model the UEGs that arise in finite systems. We argue that, in general, a UEG is characterized by at least two parameters, \textit{viz.} the usual one-electron density parameter $\rho$ and a new two-electron parameter $\eta$. We outline a systematic strategy to determine a new density functional $E(\rho,\eta)$ across the spectrum of possible $\rho$ and $\eta$ values.Comment: 8 pages, 2 figures, 5 table

Decay of proton-rich nuclei between 39Ti and 49Ni

Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in this work, 39,40Ti, 42,43Cr, 46Mn, 45,46,47Fe and 49Ni, half-lives and decay spectra have been measured. In a few cases, gamma coincidence measurements helped to successfully identify the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in our spectra and we conclude rather on a delayed particle decay.Comment: 12 pages, 15 figures, submitted for publication in Eur. Phys. J.

First observation of 55,56Zn

In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes 55,56Zn have been observed for the first time. The experiment was performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of 55,56Zn opens the way to 54Zn, a good candidate for two-proton radioactivity according to theoretical predictions.Comment: 2 pages, 1 figure, accepted for publication in Eur. Phys. J.

Tolerance of Artemia to static and shock pressure loading

Hydrostatic and hydrodynamic pressure loading has been applied to unicellular organisms for a number of years due to interest from food technology and extremophile communities. There is also an emerging interest in the response of multicellular organisms to high pressure conditions. Artemia salina is one such organism. Previous experiments have shown a marked difference in the hatching rate of these organisms after exposure to different magnitudes of pressure, with hydrostatic tests showing hatching rates at pressures up to several GPa, compared to dynamic loading that resulted in comparatively low survival rates at lower pressure magnitudes. In order to begin to investigate the origin of this difference, the work presented here has focussed on the response of Artemia salina to (quasi) one-dimensional shock loading. Such experiments were carried out using the plate-impact technique in order to create a planar shock front. Artemia cysts were investigated in this manner along with freshly hatched larvae (nauplii). The nauplii and cysts were observed post-shock using optical microscopy to detect motility or hatching, respectively. Hatching rates of 18% were recorded at pressures reaching 1.5 GPa, as determined with the aid of numerical models. Subjecting Artemia to quasi-one-dimensional shock loading offers a way to more thoroughly explore the shock pressure ranges these organisms can survive

Intra-operative Raman spectroscopy and ex vivo Raman mapping for assessment of cartilage degradation

The development of a label-free, non-destructive and safe analytical method such as Raman spectroscopy for assessing cartilage degradation is highly desirable. Compared to non-optical imaging modalities, Raman mapping offers a more sensitive means of directly assessing the chemical composition of cartilage in three-dimensional space and the potential to monitor cartilage degeneration to inform intervention and treatment strategies. Herein, we report the application of Raman spectroscopic methods ex vivo and at arthroscopy to identify molecular alterations in cartilage specimens containing minor focal lesions characteristic of the early disease phase. Our initial ex vivo analysis, obtained by single-point Raman spectroscopy of cartilage samples, supports previous findings based on S-O stretching vibration bands associated with sulphated glycosaminoglycans (sGAGs). We extended the analyses to the high-wavenumber region where we observed that vibrational bands assigned to C-H and O-H stretching modes discriminated early cartilage alterations from healthy cartilage samples. Furthermore, we performed a proof-of-concept in-clinic study using a custom-built optical probe to acquire Raman spectral measurements for the first time in patients undergoing arthroscopy of knee joints. Spectra were obtained with adequate signal-to-noise ratios that similarly discriminated between lesion and adjacent cartilage sites and identified reductions in sGAGs in apparently healthy cartilage. Building on this, we present initial results from Raman mapping to spatially resolve the molecular constituents of cartilage through its depth and across a lesion. Mapping revealed a non-uniform and reduced sGAG distribution within the lesion and peripheral cartilage that was otherwise visually normal, similar to the in-clinic observations, showing that the degradative influence of the lesion extended beyond its border. This was accompanied by a decreased fluorescence signal intensity, which suggests that fluorescence may provide valuable information as an adjunct to the Raman signal in discriminating normal and degenerating cartilage. This work demonstrates the value of Raman mapping over single-point Raman measurements for the analysis of the anisotropy of articular cartilage and highlights the potential of the technology for in vivo articular joint arthroscopy applications

Cateterização simultânea das artérias coronárias no tratamento das oclusões crónicas totais

As oclusões crónicas totais apresentam-se como um grande desafio para os cardiologistas de intervenção, sendo o seu tratamento geralmente acompanhado de um aumento das complicações. É apresentado um argumento para a utilização da cateterização simultânea das artérias coronárias para a melhoria das características da lesão e optimização dos resultados. Oito doentes com oclusões crónicas totais foram revascularizados percutaneamente utilizando esta técnica com sucesso imediato e ausência de complicações em todos eles

Three-dimensional contrast-enhanced magnetic resonance pulmonary angiography in the study of pulmonary vascular pathology

Objectives: To assess the feasibility of performing pulmonary angiography using MRI with contrast enhancement in patients with pulmonary vascular disease. Methods: We present our experience in ten individuals, two controls and eight patients who underwent the exam after injection of a gadolinium-based contrast agent on a 1 Tesla MR scanner using a time-of-flight sequence and breath-holding during injection of contrast. Results: Pathology in the main pulmonary artery and its major branches was detected easily while resolution at the segmental and subsegmental levels was inadequate. Conclusion: Contrast-enhanced magnetic resonance pulmonary angiography is feasible on a 1 Tesla MR scanner for the study of pathology of the main pulmonary artery and its major branches, like massive pulmonary embolism. However its ability to detect and define distal vessel pathology as found in chronic thromboembolic pulmonary hypertension and small pulmonary emboli is limited

Recalculation of dose for each fraction of treatment on TomoTherapy.

OBJECTIVE: The VoxTox study, linking delivered dose to toxicity requires recalculation of typically 20-37 fractions per patient, for nearly 2000 patients. This requires a non-interactive interface permitting batch calculation with multiple computers. METHODS: Data are extracted from the TomoTherapy(®) archive and processed using the computational task-management system GANGA. Doses are calculated for each fraction of radiotherapy using the daily megavoltage (MV) CT images. The calculated dose cube is saved as a digital imaging and communications in medicine RTDOSE object, which can then be read by utilities that calculate dose-volume histograms or dose surface maps. The rectum is delineated on daily MV images using an implementation of the Chan-Vese algorithm. RESULTS: On a cluster of up to 117 central processing units, dose cubes for all fractions of 151 patients took 12 days to calculate. Outlining the rectum on all slices and fractions on 151 patients took 7 h. We also present results of the Hounsfield unit (HU) calibration of TomoTherapy MV images, measured over an 8-year period, showing that the HU calibration has become less variable over time, with no large changes observed after 2011. CONCLUSION: We have developed a system for automatic dose recalculation of TomoTherapy dose distributions. This does not tie up the clinically needed planning system but can be run on a cluster of independent machines, enabling recalculation of delivered dose without user intervention. ADVANCES IN KNOWLEDGE: The use of a task management system for automation of dose calculation and outlining enables work to be scaled up to the level required for large studies.JES is supported by Cancer Research UK through the Cambridge Cancer Centre. MR, AB and KH are supported by Cancer Research UK through the VoxTox Research Programme. NGB is supported by the NIHR Cambridge Biomedical Research Centre.This is the author accepted manuscript. The final version is available from British Institute of Radiology via http://dx.doi.org/10.1259/bjr.2015077

Transferência de doentes críticos para cirurgia cardíaca urgente após colocação de balão intra-aórtico

Introdução, material e métodos: São apresentados os resultados de um estudo retrospectivo de todos os exames hemodinâmicos realizados no nosso Centro, com o objectivo de avaliar a exequibilidade e segurança de transferência para um centro cirúrgico, de doentes coronários instáveis, nos quais foi implantado um balão intra- -aórtico. No total, foram implantados 62 BIAOs, em outros tantos doentes, dos quais 24 foram transferidos para centros cirúrgicos no centro de Lisboa, numa ambulância, acompanhados de médico, enfermeiro e pessoal paramédico. Resultados: O grupo de doentes que necessitou da implantação de BIAO, era constituído por doentes com angina instável e com uma anatomia coronária que aconselhava intervenção cirúrgica imediata, doentes com hipotensão e complicações mecânicas pós-enfarte, e ainda doentes com enfarte agudo do miocárdio que não foram submetidos a trombólise e nos quais a anatomia coronária desaconselhava intervenção percutânea. Todos os doentes chegaram vivos ao hospital, não se verificando nenhuma instabilidade hemodinâmicaa e/ou eléctrica durante o transporte. Conclusões: O transporte terrestre de doentes necessitando de cirurgia de emergência nos quais foi colocado um BIAO foi fácil e seguro, podendo a prévia colocação deste device contribuir para uma melhoria clínica neste subgrupo particularmente grave de doentes

DAPK3 participates in the mRNA processing of immediate early genes in Chronic Lymphocytic Leukaemia

Cross‐linking of the B cell receptor (BCR) induces transcriptional activation of immediate early genes (IEGs) including EGR1 and DUSP2 in chronic lymphocytic leukaemia (CLL). Here, we have shown that this transcriptional activation correlated with histone H3 threonine 6 and 11 phosphorylation. Both transcription and histone post‐translational modifications are repressed by ibrutinib, a small molecule inhibitor used in CLL treatment. Moreover, we have identified the Death‐Associated Protein Kinase 3 (DAPK3), as the kinase mediating these histone phosphorylation marks in response to activation of the BCR signalling pathway with this kinase being recruited to RNA polymerase II in an anti‐IgM‐dependent manner. DAPK inhibition mimics ibrutinib‐induced repression of both IEG mRNA and histone H3 phosphorylation and has anti‐proliferative effect comparable to ibrutinib in CLL in vitro. DAPK inhibitor (DAPKi) does not repress transcription itself but impacts on mRNA processing and has a broader anti‐tumour effect than ibrutinib, by repressing both anti‐IgM‐ and CD40L‐dependent activation