| 1. |
- Metra, M., et al.
(författare)
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Effects of low-dose oral enoximone administration on mortality, morbidity, and exercise capacity in patients with advanced heart failure: the randomized, double-blind, placebo-controlled, parallel group ESSENTIAL trials
- 2009
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Ingår i: European Journal of Heart Failure. - 1522-9645. ; 30:24, s. 3015-26
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Use of inotropic agents in patients with heart failure (HF) has been limited by adverse effects on outcomes. However, administration of positive inotropes at lower doses and concomitant treatment with beta-blockers might increase benefit-risk ratio. We investigated the effects of low doses of the positive inotrope enoximone on symptoms, exercise capacity, and major clinical outcomes in patients with advanced HF who were also treated with beta-blockers and other guideline-recommended background therapy. METHODS AND RESULTS: The Studies of Oral Enoximone Therapy in Advanced HF (ESSENTIAL) programme consisted of two identical, randomized, double-blind, placebo-controlled trials that differed only by geographic location (North and South America: ESSENTIAL-I; Europe: ESSENTIAL-II). Patients with New York Heart Association class III-IV HF symptoms, left ventricular ejection fraction < or = 30%, and one hospitalization or two ambulatory visits for worsening HF in the previous year were eligible for participation in the trials. The trials had three co-primary endpoints: (i) the composite of time to all-cause mortality or cardiovascular hospitalization, analysed in the two ESSENTIAL trials combined; (ii) the 6 month change from baseline in the 6 min walk test distance (6MWTD); and (iii) the Patient Global Assessment (PGA) at 6 months, both analysed in each trial separately. ESSENTIAL-I and -II randomized 1854 subjects at 211 sites in 16 countries. In the combined trials, all-cause mortality and the composite, first co-primary endpoint did not differ between the two treatment groups [hazard ratio (HR) 0.97; 95% confidence interval (CI) 0.80-1.17; and HR 0.98; 95% CI 0.86-1.12, respectively, for enoximone vs. placebo]. The two other co-primary endpoints were analysed separately in the two ESSENTIAL trials, as prospectively designed in the protocol. The 6MWTD increased with enoximone, compared with placebo, in ESSENTIAL-I (P = 0.025, not reaching, however, the pre-specified criterion for statistical significance of P < 0.020), but not in ESSENTIAL-II. No difference in PGA was observed in either trial. CONCLUSION: Although low-dose enoximone appears to be safe in patients with advanced HF, major clinical outcomes are not improved.
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| 2. |
- Abraham, Mark J, et al.
(författare)
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Ensuring Mixing Efficiency of Replica-Exchange Molecular Dynamics Simulations
- 2008
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 4:7
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Tidskriftsartikel (refereegranskat)abstract
- We address the question of constructing a protocol for replica-exchange molecular dynamics (REMD) simulations that make efficient use of the replica space, assess whether published applications are achieving such "mixing" efficiency, and provide a how-to guide to assist users to plan efficient REMD simulations. To address our first question, we introduce and discuss three metrics for assessing the number of replica-exchange attempts required to justify the use of a replica scheme and define a "transit number" as the lower bound for the length of an efficient simulation. Our literature survey of applications of REMD simulations of peptides in explicit solvent indicated that authors are not routinely reporting sufficient details of their simulation protocols to allow readers to make independent assessments of the impact of the method on their results, particularly whether mixing efficiency has been achieved. Necessary details include the expected or observed replica-exchange probability, together with the total number of exchange attempts, the exchange period, and estimates of the autocorrelation time of the potential energy. Our analysis of cases where the necessary information was reported suggests that in many of these simulations there are insufficient exchanges attempted or an insufficiently long period between them to provide confidence that the simulation length justifies the size of the replica scheme. We suggest guidelines for designing REMD simulation protocols to ensure mixing efficiency. Two key recommendations are that the exchange period should in general be larger than 1 ps and the number of exchange attempts should be chosen to significantly exceed the transit number for the replica scheme.
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| 3. |
- Abraham, N G, et al.
(författare)
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Metabolic syndrome : psychosocial, neuroendocrine, and classical risk factors in type 2 diabetes
- 2007
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1113, s. 256-275
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Tidskriftsartikel (refereegranskat)abstract
- This article summarizes some aspects of stress in the metabolic syndrome at the psychosocial, tissue, and cellular levels. The metabolic syndrome is a valuable research concept for studying population health and social-biological translation. The cluster of cardiovascular risk factors labeled the metabolic syndrome is linked with low socioeconomic status. Systematic differences in diet and physical activity contribute to social patterning of the syndrome. In addition, psychosocial factors including chronic work stress are linked with its development. Psychosocial factors could lead to metabolic perturbations and increase cardiovascular risk via activation of neuroendocrine responses, for example, in the autonomic nervous system and in several hormonal pathways. High glucocorticoid levels will promote lipid storage in visceral rather than subcutaneous adipose tissue. Adipocytes secrete several proinflammatory cytokines, which considered major contributors to increase in oxidants and cell injury. Upregulation of heme oxygenase 1 (HO-1) and peroxidase in the early development of diabetes produces a decrease in oxidative-mediated injury. Increased HO activity is associated with a significant decrease in superoxide, endothelial cell shedding and blood pressure. Finally, it is proposed that overexpression of glutathione peroxidase in beta cells may protect beta cell deterioration from oxidative stress during development of diabetes and hyperglycemia and this may result in attenuation of beta cell failure. If this proves to be the case, then the scene will be set to develop glutathione peroxidase mimetics for use in preclinical and clinical trials.
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| 4. |
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| 5. |
- Marchesini, Stefano, et al.
(författare)
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Massively parallel X-ray holography
- 2008
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Ingår i: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 2:9, s. 560-563
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Tidskriftsartikel (refereegranskat)abstract
- Advances in the development of free-electron lasers offer the realistic prospect of nanoscale imaging on the timescale of atomic motions. We identify X-ray Fourier-transform holography(1,2,3) as a promising but, so far, inefficient scheme to do this. We show that a uniformly redundant array(4) placed next to the sample, multiplies the efficiency of X-ray Fourier transform holography by more than three orders of magnitude, approaching that of a perfect lens, and provides holographic images with both amplitude-and phase-contrast information. The experiments reported here demonstrate this concept by imaging a nano-fabricated object at a synchrotron source, and a bacterial cell with a soft-X-ray free-electron laser, where illumination by a single 15-fs pulse was successfully used in producing the holographic image. As X-ray lasers move to shorter wavelengths we expect to obtain higher spatial resolution ultrafast movies of transient states of matter.
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| 6. |
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| 7. |
- Spaanenburg, Henk A.E., et al.
(författare)
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The need for large local FPGA-accessible memories
- 2006
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Ingår i: Proceedings ISCAS. - 0780393902 ; , s. 1957-1960
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Konferensbidrag (refereegranskat)abstract
- Advanced Principles Group (APG) has developed a Reconfigurable Computing Board (RCB) based on the Xilinx Virtex-II Pro FPGA family, potentially capable of 1.5 - 2.0 TeraOps of compute power, 100 Gbps I/O on front panel, 4 Gbps I/O on backplane, as well as containing more than 4 GBytes of on-board memory. Computationally complex applications such as Software-Defined Radio, Synthetic Aperture Radar, Hyper-Spectral Imaging and Cellular Neural Networks drive similar wide bandwidths and therefore require super-computing I/O and signal processing densities far exceeding the capabilities of current and future microprocessor-based system technology. We illustrate how such applications benefit from the large amount of local FPGA-accessible memory (4+ GBytes) provided on the RCB.
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| 8. |
- Trzaskowski, Bartosz, et al.
(författare)
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Theoretical modeling of the nonenzymatic solvolysis of CMP-NeuAc in an acidic environment
- 2007
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Ingår i: Journal of Molecular Structure. - : Elsevier BV. - 0166-1280. ; 820:03-jan, s. 90-97
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Tidskriftsartikel (refereegranskat)abstract
- A density-functional-theory investigation of the nonenzymatic solvolysis of the cytydine 5'-monophosphate N-acetylneuraminic acid and its derivatives in the acidic environment is presented. The theoretical calculations of the second stage of the reaction mechanism are in agreement with the hypothesis of a dissociative oxocarbenium-like transition state with proton transfer as a key part of the reaction. The geometries of the transition states of the reactions yielding alpha-methyl and P-meth, I glycosides are essentially different. This study provides new theoretical data that can be helpful in elucidating the mechanism of the carbohydrates hydrolysis as well as other reactions catalyzed by the glycosyltransferases.
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