429 research outputs found
Six simple guidelines for introducing new genera of fungi
We formulate five guidelines for introducing new genera, plus one recommendation how to publish the results of scientific research. We recommend that reviewers and editors adhere to these guidelines. We propose that the underlying research is solid, and that the results and the final solutions are properly discussed. The six criteria are: (1) all genera that are recognized should be monophyletic; (2) the coverage of the phylogenetic tree should be wide in number of species, geographic coverage, and type species of the genera under study; (3) the branching of the phylogenetic trees has to have sufficient statistical support; (4) different options for the translation of the phylogenetic tree into a formal classification should be discussed and the final decision justified; (5) the phylogenetic evidence should be based on more than one gene; and (6) all supporting evidence and background information should be included in the publication in which the new taxa are proposed, and this publication should be peer-reviewed
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Association of white matter hyperintensities and cardiovascular disease
Cardiac and cerebrovascular diseases are currently the leading causes of mortality and disability worldwide. Both the heart and brain display similar vascular anatomy, with large conduit arteries running on the surface of the organ providing tissue perfusion through an intricate network of penetrating small vessels. Both organs rely on fine tuning of local blood flow to match metabolic demand. Blood flow regulation requires adequate functioning of the microcirculation in both organs, with loss of microvascular function, termed small vessel disease (SVD) underlying different potential clinical manifestations. SVD in the heart, known as coronary microvascular dysfunction, can cause chronic or acute myocardial ischemia and may lead to development of heart failure. In the brain, cerebral SVD can cause an acute stroke syndrome known as lacunar stroke or more subtle pathological alterations of the brain parenchyma, which may eventually lead to neurological deficits or cognitive decline in the long term. Coronary microcirculation cannot be visualized in vivo in humans, and functional information can be deduced by measuring the coronary flow reserve. The diagnosis of cerebral SVD is largely based on brain magnetic resonance imaging, with white matter hyperintensities, microbleeds, and brain atrophy reflecting key structural changes. There is evidence that such structural changes reflect underlying cerebral SVD. Here, we review interactions between SVD and cardiovascular risk factors, and we discuss the evidence linking cerebral SVD with large vessel atheroma, atrial fibrillation, heart failure, and heart valve disease
Management of syncope: clinical and economic impact of a Syncope Unit
Aims Aim of this observational study is to evaluate the clinical performance of a Syncope Unit, in order to assess whether the implemented organization really improves syncope management. Methods and results The study enrolled patients with unexplained syncope who were consecutively referred to our Syncope Unit, either as outpatients or during hospitalization, in a 2-month period. The design of this observational study consists in three phases: a retrospective analysis of their clinical. management in the 9 months prior to the first attendance at the Syncope Unit (phase one), their subsequent clinical management in the Syncope Unit (phase two) and a 9-month follow-up (phase three). The retrospective analysis of phase one showed that 25% of patients had already been hospitalized without diagnosis. After Syncope Unit evaluation, diagnosis was obtained in 82% of patients, with 15% of patients indicated to pacing. In the follow-up, 23% of patients experienced a syncopal recurrence. Our analysis indicated an 85% reduction of hospital costs in the follow-up period. Conclusion The clinical and economic analysis of the three phases of our study demonstrates that a Syncope Unit allows an improved management of patients with syncope
Injecting Electrons into CeO2 via Photoexcitation of Embedded Au Nanoparticles
The electron injection efficiency and the steady state absorptance at different photon energies for a composite system made of Au NPs embedded in a cerium oxide matrix are reported. Cerium oxide can be coupled with plasmonic nanoparticles (NPs) to improve its catalytic properties by visible-light absorption. The present work is a study of the ultrafast dynamics of excited states induced by ultraviolet and visible-light excitation in Au NPs combined with cerium oxide, aimed at understanding the excitation pathways. The data, obtained by femtosecond transient absorption spectroscopy, show that the excitation of localized surface plasmon resonances (LSPRs) in the Au NPs leads to an ultrafast injection of electrons into the empty 4f states of the surrounding cerium oxide. Within the first few picoseconds, the injected electrons couple with the lattice distortion forming a polaronic excited state, with similar properties to that formed after direct band gap excitation of the oxide. At sub-picosecond delay times, we observed relevant differences in the energetics and the time dynamics as compared to the case of band gap excitation of the oxide. Using different pump energies across the LSPR-related absorption band, the efficiency of the electron injection from the NPs into the oxide was found to be rather high, with a maximum above 30%. The injection efficiency has a different trend in energy as compared to the LSPR-related static optical absorptance, showing a significant decrease in low energies. This behavior is explained considering different deexcitation pathways with variable weight across the LSPR band. The results are important for the design of materials with high overall solar catalytic efficiency
Human liver glycogen phosphorylase inhibitors bind at a new allosteric site
AbstractBackground: Glycogen phosphorylases catalyze the breakdown of glycogen to glucose-1-phosphate for glycolysis. Maintaining control of blood glucose levels is critical in minimizing the debilitating effects of diabetes, making liver glycogen phosphorylase a potential therapeutic target.Results: The binding site in human liver glycogen phosphorylase (HLGP) for a class of promising antidiabetic agents was identified crystallographically. The site is novel and functions allosterically by stabilizing the inactive conformation of HLGP. The initial view of the complex revealed key structural information and inspired the design of a new class of inhibitors which bind with nanomolar affinity and whose crystal structure is also described.Conclusions: We have identified the binding site of a new class of allosteric HLGP inhibitors. The crystal structure revealed the details of inhibitor binding, led to the design of a new class of compounds, and should accelerate efforts to develop therapeutically relevant molecules for the treatment of diabetes
Persistent left ventricular dysfunction after acute lymphocytic myocarditis: Frequency and predictors.
BACKGROUND: Persistent left ventricular (LV) systolic dysfunction in patients with acute lymphocytic myocarditis (LM) is widely unexplored. OBJECTIVES: To assess the frequency and predictors of persistent LV dysfunction in patients with LM and reduced LVEF at admission. METHODS AND RESULTS: We retrospectively evaluated 89 consecutive patients with histologically-proven acute myocarditis enrolled at three Italian referral hospitals. A subgroup of 48 patients with LM, baseline systolic impairment and an available echocardiographic assessment at 12 months (6-18) from discharge constituted the study population. The primary study end-point was persistent LV dysfunction, defined as LVEF <50% at 1-year, and was observed in 27/48 patients (56.3%). Higher LV end-diastolic diameter at admission (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.04-1.43, p = 0.002), non-fulminant presentation (OR 8.46, 95% CI 1.28-55.75, p = 0.013) and presence of a poor lymphocytic infiltrate (OR 12.40, 95% CI 1.23-124.97, p = 0.010) emerged as independent predictors of persistent LV dysfunction at multivariate analysis (area under the curve 0.91, 95% CI 0.82-0.99). Pre-discharge LVEF was lower in patients with persistent LV dysfunction compared to the others (32%±8 vs. 53%±8, p <0.001), and this single variable showed the best accuracy in predicting the study end-point (area under the curve 0.95, 95% CI 0.89-1.00). CONCLUSIONS: More than half of patients presenting with acute LM and LVEF <50% who survive the acute phase show persistent LV dysfunction after 1-year from hospital discharge. Features of subacute inflammatory process and of established myocardial damage at initial hospitalization emerged as predictors of this end-point
Antithrombotic therapy in ventricular assist device (VAD) management : from ancient beliefs to updated evidence : a narrative review
Platelets play a key role in the pathogenesis of ventricular assist device (VAD) thrombosis; therefore, antiplatelet drugs are essential, both in the acute phase and in the long-term follow-up in VAD management. Aspirin is the most used agent and still remains the first-choice drug for lifelong administration after VAD implantation. Anticoagulant drugs are usually recommended, but with a wide range of efficacy targets. Dual antiplatelet therapy, targeting more than one pathway of platelet activation, has been used for patients developing a thrombotic event, despite an increased risk of bleeding complications. Although different strategies have been attempted, bleeding and thrombotic events remain frequent and there are no uniform strategies adopted for pharmacological management in the short and mid- or long-term follow up. The aim of this article is to provide an overview of the evidence from randomized clinical trials and observational studies with a focus on the pathophysiologic mechanisms underlying bleeding and thrombosis in VAD patients and the best antithrombotic regimens available
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