1,041 research outputs found
Melatonin Alters Age-Related Changes in Transcription Factors and Kinase Activation
Male mice were fed 40 ppm melatonin for 2 months prior to sacrifice at age 26 months, and compared with both 26 and 4 month-old untreated controls. The nuclear translocation of NF-κB increased with age in both brain and spleen and this was reversed by melatonin only in brain. Another transcription factor, AP-1 was increased with age in the spleen and not in brain and this could be blocked by melatonin treatment. The fraction of the active relative to the inactive form of several enabling kinases was compared. The proportion of activated ERK was elevated with age in brain and spleen but this change was unresponsive to melatonin. A similar age-related increase in glial fibrillary acidic protein (GFAP) was also refractory to melatonin treatment. The cerebral melatonin M1 receptor decreased with age in brain but increased in spleen. The potentially beneficial nature of melatonin for the preservation of brain function with aging was suggested by the finding that an age-related decline in cortical synaptophysin levels was prevented by dietary melatonin
Understanding innovators' experiences of barriers and facilitators in implementation and diffusion of healthcare service innovations: A qualitative study
This article is made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Barnett et al.Background: Healthcare service innovations are considered to play a pivotal role in improving organisational efficiency and responding effectively to healthcare needs. Nevertheless, healthcare organisations encounter major difficulties in sustaining and diffusing innovations, especially those which concern the organisation and delivery of healthcare services. The purpose of the present study was to explore how healthcare innovators of process-based initiatives perceived and made sense of factors that either facilitated or obstructed the innovation implementation and diffusion. Methods: A qualitative study was designed. Fifteen primary and secondary healthcare organisations in the UK, which had received health service awards for successfully generating and implementing service innovations, were studied. In-depth, semi structured interviews were conducted with the organisational representatives who conceived and led the development process. The data were recorded, transcribed and thematically analysed. Results: Four main themes were identified in the analysis of the data: the role of evidence, the function of inter-organisational partnerships, the influence of human-based resources, and the impact of contextual factors. "Hard" evidence operated as a proof of effectiveness, a means of dissemination and a pre-requisite for the initiation of innovation. Inter-organisational partnerships and people-based resources, such as champions, were considered an integral part of the process of developing, establishing and diffusing the innovations. Finally, contextual influences, both intra-organisational and extra-organisational were seen as critical in either impeding or facilitating innovators' efforts. Conclusions: A range of factors of different combinations and co-occurrence were pointed out by the innovators as they were reflecting on their experiences of implementing, stabilising and diffusing novel service initiatives. Even though the innovations studied were of various contents and originated from diverse organisational contexts, innovators' accounts converged to the significant role of the evidential base of success, the inter-personal and inter-organisational networks, and the inner and outer context. The innovators, operating themselves as important champions and being often willing to lead constructive efforts of implementation to different contexts, can contribute to the promulgation and spread of the novelties significantly.This research was supported financially by the Multidisciplinary Assessment of
Technology Centre for Healthcare (MATCH)
Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions
We report on a search for metastable positively and negatively charged states
of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864.
We have sampled approximately six billion 10% most central Au+Pb interactions
and have observed no strangelet states (baryon number A < 100 droplets of
strange quark matter). We thus set upper limits on the production of these
exotic states at the level of 1-6 x 10^{-8} per central collision. These limits
are the best and most model independent for this colliding system. We discuss
the implications of our results on strangelet production mechanisms, and also
on the stability question of strange quark matter.Comment: 21 pages, 9 figures, to be published in Nuclear Physics A (Carl Dover
memorial edition
Treatment of secondary hyperparathyroidism in haemodialysis patients: a randomised clinical trial comparing paricalcitol and alfacalcidol
<p>Abstract</p> <p>Background</p> <p>Secondary hyperparathyroidism is a common feature in patients with chronic kidney disease. Its serious clinical consequences include renal osteodystrophy, calcific uremic arteriolopathy, and vascular calcifications that increase morbidity and mortality.</p> <p>Reduced synthesis of active vitamin D contributes to secondary hyperparathyroidism. Therefore, this condition is managed with activated vitamin D. However, hypercalcemia and hyperphosphatemia limit the use of activated vitamin D.</p> <p>In Denmark alfacalcidol is the primary choice of vitamin D analog.</p> <p>A new vitamin D analog, paricalcitol, may be less prone to induce hypercalcemia and hyperphosphatemia.</p> <p>However, a randomised controlled clinical study comparing alfacalcidol and paricalcitol has never been performed.</p> <p>The primary objective of this study is to compare alfacalcidol and paricalcitol. We evaluate the suppression of the secondary hyperparathyroidism and the tendency towards hyperphosphatemia and hypercalcemia.</p> <p>Methods/Design</p> <p>This is an investigator-initiated cross-over study. Nine Danish haemodialysis units will recruit 117 patients with end stage renal failure on maintenance haemodialysis therapy.</p> <p>Patients are randomised into two treatment arms. After a wash out period of 6 weeks they receive increasing doses of alfacalcidol or paricalcitol for a period of 16 weeks and after a further wash out period of 6 weeks they receive the contrary treatment (paricalcitol or alfacalcidol) for 16 weeks.</p> <p>Discussion</p> <p>Hyperparathyroidism, hypercalcemia and hyperphosphatemia are associated with increased cardiovascular mortality in patients with chronic kidney disease.</p> <p>If there is any difference in the ability of these two vitamin D analogs to decrease the secondary hyperparathyroidism without causing hypercalcemia and hyperphosphatemia, there may also be a difference in the risk of cardiovascular mortality depending on which vitamin D analog that are used. This has potential major importance for this group of patients.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT004695</p
Symmetrical Corticobasal Syndrome Caused by a Novel c.314dup Progranulin Mutation
Corticobasal syndrome (CBS) is characterised by asymmetrical parkinsonism and cognitive impairment. The underlying pathology varies between corticobasal degeneration, progressive supranuclear palsy, Alzheimer’s disease, Creutzfeldt–Jakob disease and frontotemporal lobar degeneration sometimes in association with GRN mutations. A 61-year-old male underwent neurological examination, neuropsychological assessment, MRI, and HMPAO-SPECT at our medical centre. After his death at the age of 63, brain autopsy, genetic screening and mRNA expression analysis were performed. The patient presented with slow progressive walking disabilities, non-fluent language problems, behavioural changes and forgetfulness. His family history was negative. He had primitive reflexes, rigidity of his arms and postural instability. Later in the disease course he developed dystonia of his left leg, pathological crying, mutism and dysphagia. Neuropsychological assessment revealed prominent ideomotor and ideational apraxia, executive dysfunction, non-fluent aphasia and memory deficits. Neuroimaging showed symmetrical predominant frontoparietal atrophy and hypoperfusion. Frontotemporal lobar degeneration (FTLD)-TDP type 3 pathology was found at autopsy. GRN sequencing revealed a novel frameshift mutation c.314dup, p.Cys105fs and GRN mRNA levels showed a 50% decrease. We found a novel GRN mutation in a patient with an atypical (CBS) presentation with symmetric neuroimaging findings. GRN mutations are an important cause of CBS associated with FTLD-TDP type 3 pathology, sometimes in sporadic cases. Screening for GRN mutations should also be considered in CBS patients without a positive family history
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Measurements of the transverse-momentum-dependent cross sections of J /ψ production at mid-rapidity in proton+proton collisions at s =510 and 500 GeV with the STAR detector
We present measurements of the differential cross sections of inclusive J/ψ meson production as a function of transverse momentum (pTJ/ψ) using the μ+μ- and e+e- decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the μ+μ- channel is for
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Bulk properties of the system formed in Au+Au collisions at sNN =14.5 GeV at the BNL STAR detector
We report systematic measurements of bulk properties of the system created in Au+Au collisions at sNN=14.5 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The transverse momentum spectra of π±, K±, and p(p) are studied at midrapidity (|y|<0.1) for nine centrality intervals. The centrality, transverse momentum (pT), and pseudorapidity (η) dependence of inclusive charged particle elliptic flow (v2), and rapidity-odd charged particles directed flow (v1) results near midrapidity are also presented. These measurements are compared with the published results from Au+Au collisions at other energies, and from Pb+Pb collisions at sNN=2.76 TeV. The results at sNN=14.5 GeV show similar behavior as established at other energies and fit well in the energy dependence trend. These results are important as the 14.5-GeV energy fills the gap in μB, which is of the order of 100 MeV, between sNN=11.5 and 19.6 GeV. Comparisons of the data with UrQMD and AMPT models show poor agreement in general
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Measurement of inclusive J/ψ suppression in Au+Au collisions at sNN=200 GeV through the dimuon channel at STAR
J/ψ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive J/ψ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at sNN=200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The J/ψ yields are measured in a wide transverse momentum (pT) range of 0.15 GeV/c to 12 GeV/c from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the J/ψ yield is suppressed by a factor of approximately 3 for pT>5 GeV/c relative to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The J/ψ nuclear modification factor displays little dependence on pT in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by J/ψ mesons in the QGP
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Charge-dependent pair correlations relative to a third particle in p + Au and d + Au collisions at RHIC
Quark interactions with topological gluon configurations can induce chirality imbalance and local parity violation in quantum chromodynamics. This can lead to electric charge separation along the strong magnetic field in relativistic heavy-ion collisions – the chiral magnetic effect (CME). We report measurements by the STAR collaboration of a CME-sensitive observable in p+Au and d+Au collisions at 200 GeV, where the CME is not expected, using charge-dependent pair correlations relative to a third particle. We observe strong charge-dependent correlations similar to those measured in heavy-ion collisions. This bears important implications for the interpretation of the heavy-ion data
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