135 research outputs found
Congestive heart failure in patients with systemic hypertension : a retrospective analysis with gated bloodpool scintigraphy
Published ArticleCongestive heart failure (CHF) is a clinical syndrome that may be a manifestation of inadequate myocardial contraction (myocardial failure), volume overload or inadequate ventricular filling. In the Framingham Heart Study in participants aged 40 to 89 years and free of chronic heart failure, Levy, Larson, Vasan, Kannel & Ho (1996:1560) found a substantially greater risk for the development of CHF in both hypertensive men and women. The reason for CHF was not established i.e. systolic or diastolic dysfunction or both. More recently the effect of hypertensive left ventricular hypertrophy on left ventricular systolic function was reported in the Losartan Intervention for Endpoint (LIFE) study (Wachtell, Rokkedal, Bella, Aalto, Dahlöf, Smith, Roman, Ibsen, Aurigemma & Devereux, 2001:57). The left ventricular ejection fraction (LVEF) remains normal in most patients with left ventricular hypertrophy, but abnormal diastolic left ventricular filling in patients with high left ventricular mass was reported. The purpose of this study was to analyze the prevalence of systolic and diastolic dysfunction (or both) by means of radionuclide bloodpool scintigraphy in patients with the clinical diagnosis of hypertensive heart failure, referred to the Nuclear Medicine Department, Universitas Hospital, Bloemfontein. The LVEF did not differ significantly between the two groups, and remain within normal limits, but the mean PFR and TPF differ significantly between the two groups, indicating diastolic dysfunction in the study group. The differentiation between systolic and diastolic dysfunction has become of utmost importance because of differences in the therapeutic approach to congestive heart failure. Conventional treatment of heart failure with vasodilators, digitalis and diuretics, is irrelevant and even dangerous with diastolic dysfunction, and must be treated preferably with beta-blockers and Ca-antagonists
Parametrically Excited Surface Waves: Two-Frequency Forcing, Normal Form Symmetries, and Pattern Selection
Motivated by experimental observations of exotic standing wave patterns in
the two-frequency Faraday experiment, we investigate the role of normal form
symmetries in the pattern selection problem. With forcing frequency components
in ratio m/n, where m and n are co-prime integers, there is the possibility
that both harmonic and subharmonic waves may lose stability simultaneously,
each with a different wavenumber. We focus on this situation and compare the
case where the harmonic waves have a longer wavelength than the subharmonic
waves with the case where the harmonic waves have a shorter wavelength. We show
that in the former case a normal form transformation can be used to remove all
quadratic terms from the amplitude equations governing the relevant resonant
triad interactions. Thus the role of resonant triads in the pattern selection
problem is greatly diminished in this situation. We verify our general results
within the example of one-dimensional surface wave solutions of the
Zhang-Vinals model of the two-frequency Faraday problem. In one-dimension, a
1:2 spatial resonance takes the place of a resonant triad in our investigation.
We find that when the bifurcating modes are in this spatial resonance, it
dramatically effects the bifurcation to subharmonic waves in the case of
forcing frequencies are in ratio 1/2; this is consistent with the results of
Zhang and Vinals. In sharp contrast, we find that when the forcing frequencies
are in ratio 2/3, the bifurcation to (sub)harmonic waves is insensitive to the
presence of another spatially-resonant bifurcating mode.Comment: 22 pages, 6 figures, late
Rover Traverse Planning to Support a Lunar Polar Volatiles Mission
Studies of lunar polar volatile depositsare of interest for scientific purposes to understandthe nature and evolution of the volatiles, and alsofor exploration reasons as a possible in situ resource toenable long term exploration and settlement of theMoon. Both theoretical and observational studies havesuggested that significant quantities of volatiles exist inthe polar regions, although the lateral and horizontaldistribution remains unknown at the km scale and finerresolution. A lunar polar rover mission is required tofurther characterize the distribution, quantity, andcharacter of lunar polar volatile deposits at thesehigher spatial resolutions. Here we present two casestudies for NASAs Resource Prospector (RP) missionconcept for a lunar polar rover and utilize this missionarchitecture and associated constraints to evaluatewhether a suitable landing site exists to support an RPflight mission
âHey, look at meâ An {auto}ethnographic account of experiencing ADHD symptoms within sport.
This auto-ethnography presents a reflective analysis of my experiences of Attention Deficit Hyperactivity Disorder (ADHD) in sport. To date, research into ADHD has been largely confined to clinical evaluation and subjective interpretations. This, however, fails to advance cultural understandings and maintains the status quo. Using an autoethnographic approach, we aim to address this in-balance within sport and to give a voice to the voiceless. As an individual diagnosed with ADHD in early childhood, the first author, guided by the second author, shares and explores his experiences as both an athlete and a coach. By endeavouring to reveal the thoughts and feelings attached to key episodes within his sporting experience, the study functions to provide preliminary evidence to showcase how ADHD can impact upon those who participate in sport. Furthermore, the vignettes presented act as a vehicle to signpost the reader in accessing the available academic literature. As a result, it is hoped that this manuscript will bring further meaning to this often misunderstood condition, showcase how ADHD symptoms may present themselves within a sporting environment, and enable coaches to support those who experience similar episodes
Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with Beams of High Intensity and Large Brilliance
We study the production of radioisotopes for nuclear medicine in
photonuclear reactions or ()
photoexcitation reactions with high flux [()/s], small
diameter m and small band width () beams produced by Compton back-scattering of laser
light from relativistic brilliant electron beams. We compare them to (ion,np) reactions with (ion=p,d,) from particle accelerators like
cyclotrons and (n,) or (n,f) reactions from nuclear reactors. For
photonuclear reactions with a narrow beam the energy deposition in the
target can be managed by using a stack of thin target foils or wires, hence
avoiding direct stopping of the Compton and pair electrons (positrons).
isomer production via specially selected cascades
allows to produce high specific activity in multiple excitations, where no
back-pumping of the isomer to the ground state occurs. We discuss in detail
many specific radioisotopes for diagnostics and therapy applications.
Photonuclear reactions with beams allow to produce certain
radioisotopes, e.g. Sc, Ti, Cu, Pd, Sn,
Er, Pt or Ac, with higher specific activity and/or
more economically than with classical methods. This will open the way for
completely new clinical applications of radioisotopes. For example Pt
could be used to verify the patient's response to chemotherapy with platinum
compounds before a complete treatment is performed. Also innovative isotopes
like Sc, Cu and Ac could be produced for the first time
in sufficient quantities for large-scale application in targeted radionuclide
therapy.Comment: submitted to Appl. Phys.
Five principles for the practice of knowledge exchange in environmental management
This paper outlines five principles for effective practice of knowledge exchange, which when applied, have the potential to significantly enhance the impact of environmental management research, policy and practice. The paper is based on an empirical analysis of interviews with 32 researchers and stakeholders across 13 environmental management research projects, each of which included elements of knowledge co-creation and sharing in their design. The projects focused on a range of upland and catchment management issues across the UK, and included Research Council, Government and NGO funded projects. Preliminary findings were discussed with knowledge exchange professionals and academic experts to ensure the emerging principles were as broadly applicable as possible across multiple disciplines. The principles suggest that: knowledge exchange needs to be designed into research; the needs of likely research users and other stakeholders should be systematically represented in the research where possible; and long-term relationships must be built on trust and two-way dialogue between researchers and stakeholders in order to ensure effective co-generation of new knowledge. We found that the delivery of tangible benefits early on in the research process helps to ensure continued motivation and engagement of likely research users. Knowledge exchange is a flexible process that must be monitored, reflected on and continuously refined, and where possible, steps should be taken to ensure a legacy of ongoing knowledge exchange beyond initial research funding. The principles have been used to inform the design of knowledge exchange and stakeholder engagement guidelines for two international research programmes. They are able to assist researchers, decision-makers and other stakeholders working in contrasting environmental management settings to work together to co-produce new knowledge, and more effectively share and apply existing knowledge to manage environmental change
Identification of drug candidates targeting monocyte reprogramming in people living with HIV
INTRODUCTION: People living with HIV (PLHIV) are characterized by functional reprogramming of innate immune cells even after long-term antiretroviral therapy (ART). In order to assess technical feasibility of omics technologies for application to larger cohorts, we compared multiple omics data layers. METHODS: Bulk and single-cell transcriptomics, flow cytometry, proteomics, chromatin landscape analysis by ATAC-seq as well as ex vivo drug stimulation were performed in a small number of blood samples derived from PLHIV and healthy controls from the 200-HIV cohort study. RESULTS: Single-cell RNA-seq analysis revealed that most immune cells in peripheral blood of PLHIV are altered in their transcriptomes and that a specific functional monocyte state previously described in acute HIV infection is still existing in PLHIV while other monocyte cell states are only occurring acute infection. Further, a reverse transcriptome approach on a rather small number of PLHIV was sufficient to identify drug candidates for reversing the transcriptional phenotype of monocytes in PLHIV. DISCUSSION: These scientific findings and technological advancements for clinical application of single-cell transcriptomics form the basis for the larger 2000-HIV multicenter cohort study on PLHIV, for which a combination of bulk and single-cell transcriptomics will be included as the leading technology to determine disease endotypes in PLHIV and to predict disease trajectories and outcomes
Fighting post-COVID and ME/CFS - development of curative therapies
The sequela of COVID-19 include a broad spectrum of symptoms that fall under the umbrella term post-COVID-19 condition or syndrome (PCS). Immune dysregulation, autoimmunity, endothelial dysfunction, viral persistence, and viral reactivation have been identified as potential mechanisms. However, there is heterogeneity in expression of biomarkers, and it is unknown yet whether these distinguish different clinical subgroups of PCS. There is an overlap of symptoms and pathomechanisms of PCS with postinfectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). No curative therapies are available for ME/CFS or PCS. The mechanisms identified so far provide targets for therapeutic interventions. To accelerate the development of therapies, we propose evaluating drugs targeting different mechanisms in clinical trial networks using harmonized diagnostic and outcome criteria and subgrouping patients based on a thorough clinical profiling including a comprehensive diagnostic and biomarker phenotyping
Measurement of the cross section for isolated-photon plus jet production in pp collisions at âs=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in protonâproton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fbâ1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photonâjet invariant mass and the scattering angle in the photonâjet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
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