2,577 research outputs found
Individual dosage of digoxin in patients with heart failure
Backgroud: After the publication of DIG trial, the therapeutic target of serum digoxin concentration (SDC) for the treatment of heart failure (HF) has been lowered (0.40-1.00 ng/ml). However, the majority of equations to calculate digoxin dosages were developed for higher SDCs. Recently, a new equation was validated in Asian population for low SDCs by Konishi et al., but results in Caucasians are unknown. Aim: This study was aimed to test the Konishi equation in Caucasians specifically targeting low SDCs. Furthermore, the Konishi equation was compared with other frequently used equations. Design: This was a prospective, multicenter study. Methods: Clinically indicated digoxin was given in 40 HF patients. The dosage was calculated with the Konishi equation. The SDC was measured at 1 and 6 months after starting digoxin. Adherence to digoxin was monitored with a specific questionnaire. Results: After exclusion of patients admitting poor adherence, we found a reasonable correlation between predicted and measured SDC (r = 0.48; P < 0.01) by the Konishi equation. Excluding patients with poor adherence and relevant worsening of renal function, the measured SDC (n = 54 measurements) was within the pre-defined therapeutic range in 95% of the cases. The mean, maximal and minimal measured SDC were 0.69 ± 0.19, 1.00 and 0.32 ng/ml, respectively. The correlation was weaker for the Jelliffe, the Koup and Jusko, and the Bauman equations. Conclusions: This study supports the clinical validity of the Konishi equation for calculating individual digoxin dosage in Caucasians, targeting SDCs according to current HF guideline
Prognostic impact of systemic inflammatory diseases in elderly patients with congestive heart failure
Background and aims: Inflammation is part of the pathophysiology of congestive heart failure (CHF). However, little is known about the impact of the presence of systemic inflammatory disease (SID), defined as inflammatory syndrome with constitutional symptoms and involvement of at least two organs as co-morbidity on the clinical course and prognosis of patients with CHF. Methods and results: This is an analysis of all 622 patients included in TIME-CHF. After an 18 months follow-up, outcomes of patients with and without SID were compared. Primary endpoint was all-cause hospitalization free survival. Secondary endpoints were overall survival and CHF hospitalization free survival. At baseline, 38 patients had history of SID (6.1%). These patients had higher N-terminal pro brain natriuretic peptide and worse renal function than patients without SID. SID was a risk factor for adverse outcome [primary endpoint: hazard ratio (HR) = 1.73 (95% confidence interval: 1.18-2.55, P = 0.005); survival: HR = 2.60 (1.49-4.55, P = 0.001); CHF hospitalization free survival: HR = 2.3 (1.45-3.65, P < 0.001)]. In multivariate models, SID remained the strongest independent risk factor for survival and CHF hospitalization free survival. Conclusions: In elderly patients with CHF, SID is independently accompanied with adverse outcome. Given the increasing prevalence of SID in the elderly population, these findings are clinically important for both risk stratification and patient managemen
Impact of loop diuretic dosage in a population of patients with acute heart failure: a retrospective analysis
BackgroundLoop diuretics are essential for managing congestion in acute heart failure (AHF) patients, but concerns exist about their dosing and administration. This study aims to explore the relationship between aggressive diuretic treatment and clinical outcomes in AHF patients.MethodsWe randomly selected 370 AHF patients from admissions at Maastricht University Medical Center between January 2011 and March 2017. Patients were divided into four quartiles based on diuretic doses administrated during index hospitalization. The primary endpoint was a composite of cardiovascular (CV) rehospitalization or death at 1 year.Results42.4% of patients experimented the primary outcome The composite endpoint rates were 35.4%, 41.6%, 38.5%, and 54.9%, respectively, from lowest to highest dose quartiles (p = 0.033). In univariate analysis, the outcome was significantly lower in the first three quartiles as compared to the fourth quartile. One-year CV mortality was 9.1%, 10.1%, 20.9% and 27.2%, respectively (p = 0.002). After adjusting for confounders, the association between loop diuretic dosage disappeared for both the primary outcome and one-year CV mortality. Most secondary outcomes and endpoints at 3 months, including worsening renal function, showed no significant differences between groups, while hypokaliemia occurrence, length of hospital stay and weight loss at index admission were higher in the fourth quartile compared to the first one.ConclusionsHigh loop diuretic doses are associated with poor outcomes in AHF patients, reflecting disease severity rather than harm from aggressive diuretic use. Furthermore, high diuretic doses do not seem to negatively affect kidney function
Revisiting the Bragg reflector to illustrate modern developments in optics
Copyright © 2014 American Association of Physics TeachersA series of thin layers of alternating refractive index are known to make a good optical mirror over certain bands of frequency. Such a device, often termed the Bragg reflector, is usually introduced to students in isolation from other parts of the curriculum. Here, we show that the basic physics of wave propagation through a stratified medium can be used to illustrate some more modern developments in optics and quantum physics, from transfer matrix techniques to the optical properties of cold trapped atoms and optomechanical cooling. We also show a simple example of how such systems exhibit an appreciable level of optical nonreciprocity.Engineering and Physical Sciences Research Council (EPSRC)National Natural Science Foundation of ChinaNational Basic Research Program of ChinaCRUI-British CouncilAzione Integrata MIURFondo di Ateneo of Brescia Universit
Radiative corrections to the excitonic molecule state in GaAs microcavities
The optical properties of excitonic molecules (XXs) in GaAs-based quantum
well microcavities (MCs) are studied, both theoretically and experimentally. We
show that the radiative corrections to the XX state, the Lamb shift
and radiative width , are
large, about of the molecule binding energy , and
definitely cannot be neglected. The optics of excitonic molecules is dominated
by the in-plane resonant dissociation of the molecules into outgoing
1-mode and 0-mode cavity polaritons. The later decay channel,
``excitonic molecule 0-mode polariton + 0-mode
polariton'', deals with the short-wavelength MC polaritons invisible in
standard optical experiments, i.e., refers to ``hidden'' optics of
microcavities. By using transient four-wave mixing and pump-probe
spectroscopies, we infer that the radiative width, associated with excitonic
molecules of the binding energy meV, is
meV in the microcavities and
meV in a reference GaAs single quantum
well (QW). We show that for our high-quality quasi-two-dimensional
nanostructures the limit, relevant to the XX states, holds at
temperatures below 10 K, and that the bipolariton model of excitonic molecules
explains quantitatively and self-consistently the measured XX radiative widths.
We also find and characterize two critical points in the dependence of the
radiative corrections against the microcavity detuning, and propose to use the
critical points for high-precision measurements of the molecule bindingenergy
and microcavity Rabi splitting.Comment: 16 pages, 11 figures, accepted for publication in Phys. Rev.
"Fresnel light drag in a coherently driven moving medium"
We theoretically study how the phase of a light plane wave propagating in a resonant medium under electromagnetically induced transparency (EIT) is affected by the uniform motion of the medium. For cuprous oxide (Cu2O), where EIT can be implemented through a typical pump-probe configuration, the resonant probe beam experiences a phase shift (Fresnel-Fizeau effect) that may vary over a wide range of values, positive or negative, and even vanishing, due to the combined effects of the strong frequency dispersion and anisotropy both induced by the pump. The use of such a coherently driven dragging medium may improve by at least 1 order of magnitude the sensitivity at low velocity in optical drag experiments
Transferring research from a university to the United Kingdom National Health Service : The implications for impact
This is an Open Access article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.The aim of this article is to inform readers of the author's reflections on the experience of transferring universitybased research into the commercial sector, and of the processes and strategies employed when preparing for impact in so doing. Concepts for the transfer are illustrated by the author's reflection on aspects that arose during the birthing and subsequent start-up of a university spin-off, Pathways2Wellbeing, a form of reflection-on-action. This is the vehicle for the adaption required to transfer research into the delivery of a specialised clinic in the United Kingdom National Health Service for people with medically unexplained, persistent, bodily symptoms such as fibromyalgia, chronic fatigue and chronic pain. It is hoped that the article will provide readers with an insight into how knowledge transfer can take place through engagement with stakeholders to create an exchange of knowledges to result in impact on health service policy for service users, despite the challenges, and the enablers that facilitated this process. The reflections on the process of knowledge transfer and the implications for impact are underpinned by relevant theory.Peer reviewedFinal Published versio
Impact of sex-specific target dose in chronic heart failure patients with reduced ejection fraction
Aims: A recent study suggested that women with heart failure and heart failure reduced ejection fraction might hypothetically need lower doses of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (= renin-angiotensin-system inhibitors) and β-blockers than men to achieve the best outcome. We assessed the current medical treatment of heart failure reduced ejection fraction in men and women in a large contemporary cohort and address the hypothetical impact of changing treatment levels in women. Methods: This analysis is part of a large contemporary quality of heart failure care project which includes 5320 (64%) men and 3003 (36%) women with heart failure reduced ejection fraction. Detailed information on heart failure therapy prescription and dosage were collected. Results: Women less often received renin-angiotensin-system inhibitors (79% vs 83%, p 100% of the new hypothetical target dose would be 24% for β-blockers and 52% for renin-angiotensin-system inhibitors, which can be considered as relatively overdosed. Conclusion: In this large contemporary heart failure registry, there were significant but relatively small differences in drug dose between men and women with heart failure reduced ejection fraction. Implementation of the hypothetical sex-specific target dosing schedule would lead to considerably more women adequately treated. In contrast, we identified a group of women who might have been relatively overdosed with increased risk of side-effects and intolerance
An “Electronic Fluorescent Pictograph” Browser for Exploring and Analyzing Large-Scale Biological Data Sets
Background. The exploration of microarray data and data from other high-throughput projects for hypothesis generation has become a vital aspect of post-genomic research. For the non-bioinformatics specialist, however, many of the currently available tools provide overwhelming amounts of data that are presented in a non-intuitive way. Methodology/Principal Findings. In order to facilitate the interpretation and analysis of microarray data and data from other large-scale data sets, we have developed a tool, which we have dubbed the electronic Fluorescent Pictograph – or eFP – Browser, available a
Generalisability of Randomised Controlled Trials in Heart Failure with Reduced Ejection Fraction
BACKGROUND: Heart failure (HF) trials have stringent in- and ex- clusion criteria, but limited data exists regarding generalisability of trials. We compared patient characteristics and outcomes between patients with HF and reduced ejection fraction (HFrEF) in trials and observational registries. METHODS AND RESULTS: Individual patient data for 16922 patients from five randomised clinical trials and 46914 patients from two HF registries were included. The registry patients were categorised into trial-eligible and non-eligible groups using the most commonly used in- and ex-clusion criteria. A total of 26104 (56%) registry patients fulfilled the eligibility criteria. Unadjusted all-cause mortality rates at one year were lowest in the trial population (7%), followed by trial-eligible patients (12%) and trial-non-eligible registry patients (26%). After adjustment for age and sex, all-cause mortality rates were similar between trial participants and trial-eligible registry patients (standardised mortality ratio (SMR) 0.97; 95% confidence interval (CI) 0.92 -1.03) but cardiovascular mortality was higher in trial participants (SMR 1.19; 1.12 -1.27). After full case-mix adjustment, the SMR for cardiovascular mortality remained higher in the trials at 1.28 (1.20- 1.37) compared to RCT-eligible registry patients. CONCLUSION: In contemporary HF registries, over half of HFrEF patients would have been eligible for trial enrolment. Crude clinical event rates were lower in the trials, but, after adjustment for case-mix, trial participants had similar rates of survival as registries. Despite this, they had about 30% higher cardiovascular mortality rates. Age and sex were the main drivers of differences in clinical outcomes between HF trials and observational HF registries
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