589 research outputs found
Competition between intrinsic and extrinsic effects in the quenching of the superconducting state in FeSeTe thin films
We report the first experimental observation of the quenching of the
superconducting state in current-voltage characteristics of an iron-based
superconductor, namely, in FeSeTe thin films. Based on available theoretical
models, our analysis suggests the presence of an intrinsic flux-flow electronic
instability along with non-negligible extrinsic thermal effects. The
coexistence and competition of these two mechanisms classify the observed
instability as halfway between those of low-temperature and of high-temperature
superconductors, where thermal effects are respectively largely negligible or
predominant.Comment: 7 pages, 5 figures, fixed typo
Different Apathy Profile in Behavioral Variant of Frontotemporal Dementia and Alzheimer's Disease: A Preliminary Investigation
Apathy is one of the most common behavioral symptoms of dementia; it is one of the salient features of behavioral variant of frontotemporal dementia (bvFTD) but is also very frequent in Alzheimer's disease. This preliminary investigation was aimed at assessing the type of apathy-related symptoms in a population of bvFTD and AD subjects showing comparable apathy severity. Each patient underwent a comprehensive neuropsychological assessment; behavioral changes were investigated by the neuropsychiatric inventory (NPI), using the NPI-apathy subscale to detect apathetic symptoms. At univariate analysis, bvFTD subjects showed lack of initiation (χ2 = 4.602, p = 0.032), reduced emotional output (χ2 = 6.493, p = 0.008), and reduced interest toward friends and family members (χ2 = 4.898, p = 0.027), more frequently than AD subjects. BvFTD displayed higher scores than AD on NPI total score (p = 0.005) and on subscales assessing agitation (p = 0.004), disinhibition (p = 0.007) and sleep disturbances (p = 0.025); conversely, AD subjects were more impaired on memory, constructional abilities, and attention. On multivariate logistic regression, reduced emotional output was highly predictive of bvFTD (OR = 18.266; p = 0.008). Our preliminary findings support the hypothesis that apathy is a complex phenomenon, whose clinical expression is conditioned by the site of anatomical damage. Furthermore, apathy profile may help in differentiating bvFTD from AD
Cost-Effectiveness of Using a Molecular Diagnostic Test to Improve Preoperative Diagnosis of Thyroid Cancer
AbstractObjectiveFine-needle aspiration biopsy (FNAB) is a safe and inexpensive diagnostic procedure for evaluating thyroid nodules.Up to 25% of the results from an FNAB, however, may not be diagnostic or may be indeterminate, leading to a subsequent diagnostic thyroid surgery. A new molecularly based diagnostic test could potentially reduce indeterminate cytological results and, with high accuracy, provide a definitive diagnosis for cancer in thyroid nodules. The aim of the study was to estimate the cost-effectiveness of utilizing a molecular diagnostic (DX) test as an adjunct to FNAB, compared with NoDX, to improve the preoperative diagnosis of thyroid nodules.MethodsWe constructed a patient-level simulation model to estimate the clinical and economic outcomes of using a DX test compared with current practice (NoDX) for the diagnosis of thyroid nodules. By using a cost-effectiveness framework, we measured incremental clinical benefits in terms of quality-adjusted life-years and incremental costs over a 10-year time horizon.ResultsAssuming 95% sensitivity and specificity of the Dx test when used as an adjunct to FNAB, the utilization of the DX test resulted in a gain of 0.046 quality-adjusted life-years (95% confidence interval 0.019–0.078) and a saving of 691–1087 per test, we expect to save quality-adjusted life-years and reduce costs when it is utilized. Sensitivity of the DX test, compared with specificity, had a larger influence on the overall outcomes
Stability mechanisms of high current transport in iron-chalcogenides superconducting films
The improvement in the fabrication techniques of iron-based superconductors
have made these materials real competitors of high temperature superconductors
and MgB. In particular, iron-chalcogenides have proved to be the most
promising for the realization of high current carrying tapes. But their use on
a large scale cannot be achieved without the understanding of the current
stability mechanisms in these compounds. Indeed, we have recently observed the
presence of flux flow instabilities features in Fe(Se,Te) thin films grown on
CaF. Here we present the results of current-voltage characterizations at
different temperatures and applied magnetic fields on Fe(Se,Te) microbridges
grown on CaF. These results will be analyzed from the point of view of the
most validated models with the aim to identify the nature of the flux flow
instabilities features (i.e., thermal or electronic), in order to give a
further advance to the high current carrying capability of iron-chalcogenide
superconductors.Comment: 4 pages, 3 figure
A systematic review of economic evaluations of therapy in asthma
Katayoun Bahadori1, Bradley S Quon2, Mary M Doyle-Waters1, Carlo Marra3, J Mark FitzGerald21Centre for Clinical Epidemiology and Evaluation (C2E2), 2Department of Medicine, Respiratory Division, 3Faculty of Pharmaceutical Sciences, UBC, Vancouver, BC, CanadaBackground: Asthma’s cost-effectiveness is a major consideration in the evaluation of its treatment options. Our objective was to perform a systematic review of the cost-effectiveness of asthma medications.Methods: We performed a systematic search of MEDLINE, EMBASE, CINAHL, Cochrane Database of Systematic Reviews, OHE-HEED, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Health Technology Assessments Database, NHS Economic Evaluation Database, and Web of Science and reviewed references from key articles between 1990 and Jan 2008.Results: A total of 49 RCTs met the inclusion criteria. Maintenance therapy with inhaled corticosteroids was found to be very cost-effective and in uncontrolled asthmatics patients currently being treated with ICS, the combination of an ICS/LABA represents a safe, cost-effective treatment. The simplified strategy using budesonide and formoterol for maintenance and reliever therapy was also found to be as cost-effective as salmeterol/fluticasone plus salbutamol. Omalizumab was found to be cost-effective. An important caveat with regard to the published literature is the relatively high proportion of economic evaluations which are funded by the manufacturers of specific drug treatments.Conclusion: Future studies should be completed independent of industry support and ensure that the comparator arms within studies should include dosages of drugs that are equivalent.Keywords: asthma, medication, cost-effectiveness, cost of illness, economic cost
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Future Impact of Various Interventions on the Burden of COPD in Canada: A Dynamic Population Model
Background: Chronic obstructive pulmonary disease (COPD) is a growing economic burden worldwide. Smoking cessation is thought to be the single most effective way of reducing the economic burden of COPD. The impact of other strategies such as interventions that predict risk of disease, reduce progression of disease, or reduce exacerbations has not been systematically studied. Objectives: We estimated the economic and clinical burden of COPD over the next 25 years in Canada and the impact of three potential interventions (screening test for predisposition to COPD, new drugs to avoid progression into more severe disease stages, and predictive test for exacerbations) on COPD burden. Methods Using a dynamic simulation model, we projected the total burden of COPD (cost, morbidity, and mortality) from 2011 to 2035 using the population of Canada as a case study. The model stratified population based on sex, age, smoking status, respiratory symptoms, and their COPD stage. The cost and quality adjusted life years (QALYs) associated with each intervention were estimated. Results: The model indicates that annual societal cost of COPD is 3.61B (101.4B in societal costs ($147.5B undiscounted) and 12.9 million QALYs lost (19.0 million undiscounted). Our results suggested that the best strategy to reduce the financial burden of COPD is by reducing exacerbations. Smoking cessation, while it is the cornerstone of COPD prevention, has only a modest effect in attenuating the financial burden of COPD over the next 25 years in Western countries such as Canada. Conclusion: Our data suggest that any intervention that can reduce the number of exacerbations has a substantial impact on morbidity and costs of COPD and should be considered in conjunction with the ongoing efforts to reduce smoking rates
Safety of Extracorporeal Shockwave Myocardial Revascularization (ESMR) in Patient with a Mechanical Prosthetic Valve
Cerebellar white matter disruption in Alzheimer’s Disease patients: a Diffusion Tensor Imaging study
The cognitive role of the cerebellum has recently gained much attention, and its pivotal role in Alzheimer’s disease (AD) has now been widely recognized. Diffusion tensor imaging (DTI) has been used to evaluate the disruption of the microstructural milieu in AD, and though several white matter (WM) tracts such as corpus callosum, inferior and superior longitudinal fasciculus, cingulum, fornix, and uncinate fasciculus have been evaluated in AD, data on cerebellar WM tracts are currently lacking. We performed a tractography-based DTI reconstruction of the middle cerebellar peduncle (MCP), and the left and right superior cerebellar peduncles separately (SCPL and SCPR) and addressed the differences in fractional anisotropy (FA), axial diffusivity (Dax), radial diffusivity (RD), and mean diffusivity (MD) in the three tracts between 50 patients with AD and 25 healthy subjects. We found that AD patients showed a lower FA and a higher RD compared to healthy subjects in MCP, SCPL, and SCPR. Moreover, a higher MD was found in SCPR and SCPL and a higher Dax in SCPL. This result is important as it challenges the traditional view that WM bundles in the cerebellum are unaffected in AD and might identify new targets for therapeutic interventions
The Impact of GLP-1 RAs and DPP-4is on Hospitalisation and Mortality in the COVID-19 Era: A Two-Year Observational Study
Novel antidiabetic drugs have the ability to produce anti-inflammatory effects regardless of their glucose-lowering action. For this reason, these molecules (including GLP-1 RAs and DPP-4is) were hypothesized to be effective against COVID-19, which is characterized by cytokines hyperactivity and multiorgan inflammation. The aim of our work is to explore the potential protective role of GLP-1 RAs and DPP-4is in COVID-19 (with the disease intended to be a model of an acute stressor) and non-COVID-19 patients over a two-year observation period. Retrospective and one-versus-one analyses were conducted to assess the impact of antidiabetic drugs on the need for hospitalization (in both COVID-19- and non-COVID-19-related cases), in-hospital mortality, and two-year mortality. Logistic regression analyses were conducted to identify the variables associated with these outcomes. Additionally, log-rank tests were used to plot survival curves for each group of subjects, based on their antidiabetic treatment. The performed analyses revealed that despite similar hospitalization rates, subjects undergoing home therapy with GLP-1 RAs exhibited significantly lower mortality rates, even over a two-year period. These individuals demonstrated improved survival estimates both within hospital and non-hospital settings, even during a longer observation period
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