330 research outputs found

    Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope

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    We present new photometric data of 11 hot Jupiter transiting exoplanets (CoRoT-12b, HAT-P-5b, HAT-P-12b, HAT-P-33b, HAT-P-37b, WASP-2b, WASP-24b, WASP-60b, WASP-80b, WASP-103b, XO-3b) in order to update their planetary parameters and to constrain information about their atmospheres. These observations of CoRoT-12b, HAT-P-37b and WASP-60b are the first follow-up data since their discovery. Additionally, the first near-UV transits of WASP-80b and WASP-103b are presented. We compare the results of our analysis with previous work to search for transit timing variations (TTVs) and a wavelength dependence in the transit depth. TTVs may be evidence of a third body in the system and variations in planetary radius with wavelength can help constrain the properties of the exoplanet's atmosphere. For WASP-103b and XO-3b, we find a possible variation in the transit depths that may be evidence of scattering in their atmospheres. The B-band transit depth of HAT-P-37b is found to be smaller than its near-IR transit depth and such a variation may indicate TiO/VO absorption. These variations are detected from 2-4.6σ\sigma, so follow-up observations are needed to confirm these results. Additionally, a flat spectrum across optical wavelengths is found for 5 of the planets (HAT-P-5b, HAT-P-12b, WASP-2b, WASP-24b, WASP-80b), suggestive that clouds may be present in their atmospheres. We calculate a refined orbital period and ephemeris for all the targets, which will help with future observations. No TTVs are seen in our analysis with the exception of WASP-80b and follow-up observations are needed to confirm this possible detection.Comment: 18 pages, 7 figures, 9 Tables. Light Curves available online. Accepted to MNRAS (2017 August 25

    Intergenomic and epistatic interactions control free radical mediated pancreatic β-cell damage.

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    Alloxan (AL)-generated Reactive Oxygen Species (ROS) selectively destroy insulin-producing pancreatic β-cells. A previous genome-wide scan (GWS) using a cohort of 296 F2 hybrids between NOD (AL-sensitive) and ALR (AL-resistant) mice identified linkages contributing to β-cell susceptibility or resistance to AL-induced diabetes on Chromosomes (Chr) 2, 3, 8, and a single nucleotide polymorphism i

    Water-soluble ionic carbon nitride as unconventional stabilizer for highly catalytically active ultrafine gold nanoparticles

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    Ultrafine metal nanoparticles (NPs) hold promise for applications in many fields, including catalysis. However, ultrasmall NPs are typically prone to aggregation, which often leads to performance losses, such as severe deactivation in catalysis. Conventional stabilization strategies (e.g., immobilization, embedding, or surface modification by capping agents) are typically only partly effective and often lead to loss of catalytic activity. Herein, a novel type of stabilizers based on water-soluble ionic (K+^+ and Na+^+ containing) polymeric carbon nitride (i.e., K,Na-poly(heptazine imide) = K,Na-PHI) is reported that enables effective stabilization of highly catalytically active ultrafine (size of ∼2–3 nm) gold NPs. Experimental and theoretical comparative studies using different structural units of K,Na-PHI (i.e., cyanurate, melonate, cyamelurate) indicate that the presence of functionalized heptazine moieties is crucial for the synthesis and stabilization of small Au NPs. The K,Na-PHI-stabilized Au NPs exhibit remarkable dispersibility and outstanding stability even in solutions of high ionic strength, which is ascribed to more effective charge delocalization in the large heptazine units, resulting in more effective electrostatic stabilization of Au NPs. The outstanding catalytic performance of Au NPs stabilized by K,Na-PHI is demonstrated using the selective reduction of 4-nitrophenol to 4-aminophenol by NaBH4_4 as a model reaction, in which they outperform even the benchmark “naked” Au NPs electrostatically stabilized by excess NaBH4_4. This work thus establishes ionic carbon nitrides (PHI) as alternative capping agents enabling effective stabilization without compromising surface catalysis, and opens up a route for further developments in utilizing PHI-based stabilizers for the synthesis of high-performance nanocatalysts

    Alirocumab versus usual lipid-lowering care as add-on to statin therapy in individuals with type 2 diabetes and mixed dyslipidaemia:The ODYSSEY DM-DYSLIPIDEMIA randomized trial

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    Individuals with type 2 diabetes (T2DM) and mixed dyslipidaemia represent a high-risk and difficult-to-treat population. ODYSSEY DM-DYSLIPIDEMIA (NCT02642159) compared alirocumab, a proprotein convertase subtilisin-kexin type 9 inhibitor, with usual care (UC) in individuals with T2DM and mixed dyslipidaemia not optimally managed by maximally-tolerated statins

    No effect of PCSK9 inhibitor alirocumab on the incidence of diabetes in a pooled analysis from 10 ODYSSEY Phase 3 studies

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    AIMS: Statins have modest adverse effects on glycaemic control. Alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, lowers low-density lipoprotein cholesterol. This study assessed the effects of alirocumab on new-onset diabetes and pre-diabetes incidence in individuals without diabetes at baseline. METHODS AND RESULTS: Pooled analysis of 10 ODYSSEY Phase 3 trials (n = 4974) of 24–104 weeks duration. Six trials (n = 4211) were ≥52 weeks in length. Most patients received background maximally tolerated statin. Alirocumab effect on the rate of diabetes-related treatment-emergent adverse events (TEAEs), and/or fasting plasma glucose (FPG) and glycated haemoglobin A(1C) (HbA(1C)) was measured at baseline and every 12–24 weeks. Transition to diabetes analysis combined TEAE and FPG/HbA(1C) laboratory data. At baseline, 30.7% of individuals had diabetes and were excluded from the current analysis. The remaining 3448 individuals without diabetes had pre-diabetes (39.6%) or were normoglycaemic (29.7%). The hazard ratio (HR; 95% confidence interval) for diabetes-related TEAEs in alirocumab was 0.64 (0.36–1.14) vs. placebo and 0.55 (0.22–1.41) vs. ezetimibe. The HR associated for transition from pre-diabetes to new-onset diabetes for alirocumab was 0.90 (0.63–1.29) vs. placebo and 1.10 (0.57–2.12) vs. ezetimibe. Mean change in FPG/HbA(1C) over time showed no difference between treatment groups in patients without diabetes. CONCLUSIONS: There was no evidence of an effect of alirocumab on transition to new-onset diabetes in 3448 individuals without diabetes at baseline with a follow-up period of 6–18 months, compared to either placebo or ezetimibe. Longer follow-up with larger number of individuals is needed to conclusively rule out an effect

    A Study in Red: The Overlooked Role of Azo‐Moieties in Polymeric Carbon Nitride Photocatalysts with Strongly Extended Optical Absorption

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    The unique optical and photoredox properties of heptazine-based polymeric carbon nitride (PCN) materials make them promising semiconductors for driving various productive photocatalytic conversions. However, their typical absorption onset at ca. 430–450 nm is still far from optimum for efficient sunlight harvesting. Despite many reports of successful attempts to extend the light absorption range of PCNs, the determination of the structural features responsible for the red shift of the light absorption edge beyond 450 nm has often been obstructed by the highly disordered structure of PCNs and/or low content of the moieties responsible for changes in optical and electronic properties. In this work, we implement a high-temperature (900 °C) treatment procedure for turning the conventional melamine-derived yellow PCN into a red carbon nitride. This approach preserves the typical PCN structure but incorporates a new functionality that promotes visible light absorption. A detailed characterization of the prepared material reveals that partial heptazine fragmentation accompanied by de-ammonification leads to the formation of azo-groups in the red PCN, a chromophore moiety whose role in shifting the optical absorption edge of PCNs has been overlooked so far. These azo moieties can be activated under visible-light (470 nm) for H₂ evolution even without any additional co-catalyst, but are also responsible for enhanced charge-trapping and radiative recombination, as shown by spectroscopic studies

    Cost-effectiveness of ticagrelor in patients with type 2 diabetes and coronary artery disease: a European economic evaluation of the THEMIS trial.

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    To conduct a health economic evaluation of ticagrelor in patients with type 2 diabetes and coronary artery disease (CAD) from a multinational payer perspective. Cost-effectiveness and cost-utility of ticagrelor were evaluated in the overall effect of Ticagrelor on Health Outcomes in Diabetes Mellitus Patients Intervention Study (THEMIS) trial population and in the predefined patient group with prior percutaneous coronary intervention. A Markov model was developed to extrapolate patient outcomes over a lifetime horizon. The primary outcome was incremental cost-effectiveness ratios (ICERs), which were compared with conventional willingness-to-pay thresholds [€47 000/quality-adjusted life-year (QALY) in Sweden and €30 000/QALY in other countries].Treatment with ticagrelor resulted in QALY gains of up to 0.045 in the overall population and 0.099 in patients with percutaneous coronary intervention (PCI). Increased costs and benefits translated to ICERs ranged between €27 894 and €42 252/QALY across Sweden, Germany, Italy, and Spain in the overall population. In patients with prior PCI, estimated ICERs improved to €18 449, €20 632, €20 233, and €13 228/QALY in Sweden, Germany, Italy, and Spain, respectively, driven by higher event rates and treatment benefit. Based on THEMIS results, ticagrelor plus aspirin compared with aspirin alone may be cost-effective in some European countries in patients with T2DM and CAD and no prior myocardial infarction (MI) or stroke. Additionally, ticagrelor is likely to be cost-effective across European countries in patients with a history of PCI.This work was supported by AstraZeneca.S

    External applicability of the Effect of ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS) trial: An analysis of patients with diabetes and coronary artery disease in the REduction of Atherothrombosis for Continued Health (REACH) registry.

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    THEMIS is a double-blind, randomized trial of 19,220 patients with diabetes mellitus and stable coronary artery disease (CAD) comparing ticagrelor to placebo, in addition to aspirin. The present study aimed to describe the proportion of patients eligible and reasons for ineligibility for THEMIS within a population of patients with diabetes and CAD included in the Reduction of Atherothrombosis for Continued Health (REACH) registry. The THEMIS eligibility criteria were applied to REACH patients. THEMIS included patients ≥50 years with type 2 diabetes and stable CAD as determined by either a history of previous percutaneous coronary intervention, coronary artery bypass grafting, or documentation of angiographic stenosis of ≥50% of at least one coronary artery. Patients with prior myocardial infarction or stroke were excluded. In REACH, 10,156 patients had stable CAD and diabetes. Of these, 6515 (64.1%) patients had at least one exclusion criteria. From the remaining population, 784 patients did not meet inclusion criteria (7.7%) mainly due to absence of aspirin treatment (7.2%), yielding a 'THEMIS-eligible population' of 2857 patients (28.1% of patients with diabetes and stable CAD). The main reasons for exclusion were a history of myocardial infarction (53.1%), use of oral anticoagulation (14.5%), or history of stroke (12.9%). Among the 4208 patients with diabetes and a previous PCI, 1196 patients (28.4%) were eligible for inclusion in the THEMIS-PCI substudy. In a population of patients with diabetes and stable coronary artery disease, a sizeable proportion appear to be 'THEMIS eligible.' http://www. gov identifier: NCT01991795.The THEMIS trial was funded by AstraZeneca. The REACH registry was sponsored by Sanofi, Bristol-Myers Squibb, and the Waksman Foundation (Tokyo, Japan) and is endorsed by the World Heart Federation.S
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