82 research outputs found

    Bandwidth Control and Symmetry Breaking in a Mott-Hubbard Correlated Metal

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    In Mott materials strong electron correlation yields a spectrum of complex electronic structures. Recent synthesis advancements open realistic opportunities for harnessing Mott physics to design transformative devices. However, a major bottleneck in realizing such devices remains the lack of control over the electron correlation strength. This stems from the complexity of the electronic structure, which often veils the basic mechanisms underlying the correlation strength. Here, we present control of the correlation strength by tuning the degree of orbital overlap using picometer-scale lattice engineering. We illustrate how bandwidth control and concurrent symmetry breaking can govern the electronic structure of a correlated SrVO3SrVO_3 model system. We show how tensile and compressive biaxial strain oppositely affect the SrVO3SrVO_3 in-plane and out-of-plane orbital occupancy, resulting in the partial alleviation of the orbital degeneracy. We derive and explain the spectral weight redistribution under strain and illustrate how high tensile strain drives the system towards a Mott insulating state. Implementation of such concepts will drive correlated electron phenomena closer towards new solid state devices and circuits. These findings therefore pave the way for understanding and controlling electron correlation in a broad range of functional materials, driving this powerful resource for novel electronics closer towards practical realization

    Improved Normothermic Machine Perfusion After Short Oxygenated Hypothermic Machine Perfusion of Ischemically Injured Porcine Kidneys

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    Background: In an era where global kidney shortage has pushed the field of transplantation towards using more marginal donors, modified kidney preservation techniques are currently being reviewed. Some techniques require further optimization before implementation in full scale transplantation studies. Using a porcine donation after circulatory death kidney model, we investigated whether initial kidney hemodynamics improved during normothermic machine perfusion if this was preceded by a short period of oxygenated hypothermic machine perfusion (oxHMP) rather than static cold storage (SCS). Methods: Kidneys subjected to 75 minutes of warm ischemia were randomly assigned to either SCS (n = 4) or SCS + oxHMP (n = 4), with a total cold storage time of 240 minutes. Cold preservation was followed by 120 minutes of normothermic machine perfusion with continuous measurement of hemodynamic parameters and renal function. Results: oxHMP preserved kidneys maintained significantly lower renal resistance throughout the normothermic machine perfusion period compared to SCS kidneys (P < 0.001), reaching lowest levels at 60 minutes with means of 0.71 ± 0.35 mm Hg/mL/min/100 g (SCS) and 0.45 ± 0.15 mm Hg/mL/min/100 g (oxHMP). Accordingly, the oxHMP group had a higher mean renal blood flow versus SCS kidneys (P < 0.001). oxHMP kidneys had higher oxygen consumption during normothermic machine perfusion compared to SCS preserved kidneys (P < 0.001). Creatinine clearance remained similar between groups (P = 0.665). Conclusions: Preceding oxHMP significantly improved initial normothermic machine perfusion hemodynamics and increased total oxygen consumption. With the long period of warm ischemia, immediate kidney function was not observed, reflected by the findings of low creatinine clearance in both groups

    Endothelial overexpression of LOX-1 increases plaque formation and promotes atherosclerosis in vivo

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    Aims Lectin-like oxLDL receptor-1 (LOX-1) mediates the uptake of oxidized low-density lipoprotein (oxLDL) in endothelial cells and macrophages. However, the different atherogenic potential of LOX-1-mediated endothelial and macrophage oxLDL uptake remains unclear. The present study was designed to investigate the in vivo role of endothelial LOX-1 in atherogenesis. Methods and results Endothelial-specific LOX-1 transgenic mice were generated using the Tie2 promoter (LOX-1TG). Oxidized low-density lipoprotein uptake was enhanced in cultured endothelial cells, but not in macrophages of LOX-1TG mice. Six-week-old male LOX-1TG and wild-type (WT) mice were fed a high-cholesterol diet (HCD) for 30 weeks. Increased reactive oxygen species production, impaired endothelial nitric oxide synthase activity and endothelial dysfunction were observed in LOX-1TG mice as compared with WT littermates. LOX-1 overexpression led to p38 phosphorylation, increased nuclear factor κB activity and subsequent up-regulation of vascular cell adhesion molecule-1, thereby favouring macrophage accumulation and aortic fatty streaks. Consistently, HCD-fed double-mutant LOX-1TG/ApoE−/− displayed oxidative stress and vascular inflammation with higher aortic plaques than ApoE−/− controls. Finally, bone marrow transplantation experiments showed that endothelial LOX-1 was sufficient for atherosclerosis development in vivo. Conclusions Endothelial-specific LOX-1 overexpression enhanced aortic oxLDL levels, thereby favouring endothelial dysfunction, vascular inflammation and plaque formation. Thus, LOX-1 may serve as a novel therapeutic target for atherosclerosi

    The Effect of Dapagliflozin on Albuminuria in DECLARE-TIMI 58

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    OBJECTIVE Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve albuminuria in patients with high cardiorenal risk. We report albuminuria change in the Dapagliflozin Effect on Cardiovascular Events (DECLARE-TIMI 58) cardiovascular outcome trial, which included populations with lower cardiorenal risk. RESEARCH DESIGN AND METHODS DECLARE-TIMI 58 randomized 17,160 patients with type 2 diabetes, creatinine clearance >60 mL/min, and either atherosclerotic cardiovascular disease (CVD; 40.6%) or risk-factors for CVD (59.4%) to dapagliflozin or placebo. Urinary albumin-to-creatinine ratio (UACR) was tested at baseline, 6 months, 12 months, and yearly thereafter. The change in UACR over time was measured as a continuous and categorical variable (15 to = 30 to 300 mg/g) by treatment arm. The composite cardiorenal outcome was a >= 40% sustained decline in the estimated glomerular filtration rate (eGFR) to 15 to 300 mg/g. Measured as a continuous variable, UACR improved from baseline to 4.0 years with dapagliflozin, compared with placebo, across all UACR and eGFR categories (all P = 1 category improvement in UACR was more common in dapagliflozin versus placebo (hazard ratio 1.45 [95% CI 1.35-1.56], P = 30 mg/g (P < 0.0125, P-interaction = 0.033), and the renal-specific outcome was reduced for all UACR subgroups (P < 0.05, P-interaction = 0.480). CONCLUSIONS In DECLARE-TIMI 58, dapagliflozin demonstrated a favorable effect on UACR and renal-specific outcome across baseline UACR categories, including patients with normal albumin excretion. The results suggest a role for SGLT2i also in the primary prevention of diabetic kidney disease

    Seven recommendations to make your invasive alien species data more useful

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    Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost

    Cardiorenal outcomes with dapagliflozin by baseline glucose-lowering agents: Post hoc analyses fromDECLARE-TIMI58

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    Aim To assess the associations between baseline glucose-lowering agents (GLAs) and cardiorenal outcomes with dapagliflozin versus placebo in the DECLARE-TIMI 58 study. Materials and methods DECLARE-TIMI 58 assessed the cardiorenal outcomes of dapagliflozin versus placebo in patients with type 2 diabetes. This post hoc analysis elaborates the efficacy and safety outcomes by baseline GLA for treatment effect and GLA-based treatment interaction. Results At baseline, 14 068 patients (82.0%) used metformin, 7322 (42.7%) sulphonylureas, 2888 (16.8%) dipeptidyl peptidase-4 inhibitors, 750 (4.4%) glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and 7013 (40.9%) insulin. Dapagliflozin reduced the composite of cardiovascular death (CVD) and hospitalization for heart failure (HHF) versus placebo regardless of baseline GLA, with greater benefit in the small group of patients with baseline use of GLP-1 RAs (HR [95% CI] 0.37 [0.18, 0.78] vs. 0.86 [0.75, 0.98] in GLP-1 RA users vs. non-users,P-interaction= .03). The overall HR for major adverse cardiovascular events (CVD, myocardial infarction or ischaemic stroke) was 0.93 (95% CI 0.84, 1.03) with dapagliflozin versus placebo, with no interaction by baseline GLA (P-interaction> .05). The renal-specific outcome was reduced with dapagliflozin versus placebo in the overall cohort (HR [95%CI] 0.53[0.43-0.66]), with no interaction by baseline GLA (P-interaction> .05). All of these outcomes were similar in those with versus those without baseline metformin use. Conclusions The effects of dapagliflozin on cardiorenal outcomes were generally consistent regardless of baseline GLA, with consistent benefits regardless of baseline metformin use. The potential clinical benefit of combining sodium-glucose co-transporter-2 inhibitors with GLP-1 RAs, given some evidence of cardiovascular risk reduction with both classes, should be explored further

    Climate, host and geography shape insect and fungal communities of trees.

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    Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate

    Maternal outcomes and risk factors for COVID-19 severity among pregnant women.

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    Pregnant women may be at higher risk of severe complications associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may lead to obstetrical complications. We performed a case control study comparing pregnant women with severe coronavirus disease 19 (cases) to pregnant women with a milder form (controls) enrolled in the COVI-Preg international registry cohort between March 24 and July 26, 2020. Risk factors for severity, obstetrical and immediate neonatal outcomes were assessed. A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented with severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of caesarean section [70.7% (n = 53/75)], preterm delivery [62.7% (n = 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n = 31/75)]. In this study, several risk factors for developing severe complications of SARS-CoV-2 infection among pregnant women were identified including pulmonary comorbidities, hypertensive disorders and diabetes. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease
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