48 research outputs found

    Characterizing and Prognosticating Heart Failure with Improved Ejection Fraction Using NT-proBNP, Growth Differentiation Factor 15 and Global Longitudinal Strain

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    Background: Heart failure with improved ejection fraction (HFiEF) is a novel heart failure (HF) subgroup. There are sparse data on using NT-proBNP, growth differentiation factor 15 (GDF15) and global longitudinal strain (GLS) to characterize and prognosticate HFiEF patients. Objectives: (1) To determine the level and correlation between NT-proBNP, GDF-15 and GLS in HFiEF patients. (2) To examine the correlation of each marker with NYHA, MAGGIC prognostic score, HF etiologies, comorbidities status, degree of LVEF/ LV end-diastolic diameter change from baseline and diastolic dysfunction. (3) To look for association of each marker with follow-up LVEF change and 1-year composite mortality or HF events outcome. Materials & Methods: This was a cross-sectional observational study in Sarawak Heart Centre HF clinic. 53 HfiEF patients who had NT-proBNP and GDF15 tests performed were selected. This cohort had no HF events in the past 6 months during the blood tests. Clinical characteristics, echocardiography parameters, and 1-year composite clinical outcome were analyzed retrospectively. Results: The mean age of the cohort was 52 years old and 81% were male. The cohort was highly comorbid (hypertension 71%; diabetes 45.3%; AF 17.3%). Most of the patients (87%) were asymptomatic by NYHA (I) and low rate of composite outcome was observed, 5.7%. The mean NT-proBNP, GDF-15, GLS were 357 pg/ml, 1572 pg/ml, and -12.1% respectively. There were significant moderate correlation between GDF15 with NT-proBNP (r=0.414) and NT-proBNP with GLS (r=-0.351). Higher NT-proBNP and GDF15 levels were associated with poorer MAGGIC prognostic scores (r=0.549, 0.41 respectively). NT-proBNP was the only marker associated with a higher degree of LVEF improvement compare to baseline echocardiography. NT-proBNP was also related to severe diastolic echo parameters. Hypertension and diabetes were strongly associated with higher elevated GDF15 levels. The lower mean GLS level was significantly associated with the presence of composite outcome (-6.45% vs -12.47%, p=0.0). Patients with NT-proBNP levels below the median cutoff had favourable follow-up LVEF improvement (+9.73%, p=0.035). Conclusion: In our HFiEF study cohort, NT-proBNP best correlate and prognosticate future LV remodelling. GDF15 was closely related to systemic illnesses such as diabetes. The role of GLS in our HFiEF cohort remains uncertain

    T cell metabolism drives immunity

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    Lymphocytes must adapt to a wide array of environmental stressors as part of their normal development, during which they undergo a dramatic metabolic remodeling process. Research in this area has yielded surprising findings on the roles of diverse metabolic pathways and metabolites, which have been found to regulate lymphocyte signaling and influence differentiation, function and fate. In this review, we integrate the latest findings in the field to provide an up-to-date resource on lymphocyte metabolism

    Inverted Polymer Solar Cells with an Ultrathin Lithium Fluoride Buffer Layer

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    An ultrathin lithium fluoride (LiF) buffer layer was applied to inverted polymer solar cells with P3HT [poly(3-hexylthiophene)]:PCBM [[6,6]-phenyl C 61-butyric acid methyl ester] blend films. By inserting the LiF layer between the transparent electrode and the P3HT:PCBM blend film, all parameters, including the short-circuit current, the open-circuit voltage and the fill factor, were enhanced compared to those of a reference cell without the LiF layer. The power conversion efficiency of the device with the LiF layer was thereby improved by more than 300% relative to the reference cell. © 2012 American Scientific Publishers.1

    Improved performance of dye-sensitized solar cells with surface-treated TiO2 as a photoelectrode

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    We report on the effects of surface-modified TiO 2 on the performance of dye-sensitized solar cells (DSSCs). TiO 2 surface was modified with Na 2CO 3 via a simple dip coating process and the modified TiO 2 was applied to photoelectrodes of DSSCs. By dipping of TiO 2 layer into aqueous Na 2CO 3 solution, the DSSC showed a power conversion efficiency of 9.98%, compared to that (7.75%) of the reference device without surface treatment. The UV-vis absorption spectra, the impedance spectra and the dark current studies revealed that the increase of all parameters was attributed to the enhanced dye adsorption, the prolonged electron lifetime and the reduced interfacial resistance. © 2012 Elsevier Ltd. All rights reserved.1

    Study of reaction mechanisms and synthetic manipulations of bismuth tellurium selenide nanomaterials for enhanced thermoelectric performance

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    We synthesized ternary n-type bismuth tellurium selenide nanomaterials for thermoelectric applications via a water-based chemical reaction under an atmospheric environment. In this work, bismuth nitrate was employed as a bismuth precursor and was hydrolyzed to form bismuth hydroxide in an aqueous solution. Ascorbic acid was used to dissolve the bismuth hydroxide and give a reactive bismuth source (Bi3+ ions) that was able to react with anion sources (Te2-/Se2- ions). Ascorbic acid played a role in reducing bismuth hydroxide to an unreactive bismuth source (bismuth particles, Bi 0). We confirmed that ascorbic acid dissolved or reduced bismuth hydroxide depending on the solution pH. Because either Bi3+ ions or bismuth particles were generated depending on the pH, the nanomaterial stoichiometry was pH dependent. Nanomaterials prepared at various pH levels were individually sintered using a spark plasma sintering process to measure their thermoelectric transport properties (i.e., carrier concentration, electrical resistivity, Seebeck coefficient, and thermal conductivity). We observed how the transport properties were affected through adjustment of the pH of the reaction and found an appropriate pH for optimizing the transport properties, which resulted in enhancement of the thermoelectric performance. © 2013 Elsevier B.V. All rights reserved.1

    In Situ Engineering of the Electrode-Electrolyte Interface for Stabilized Overlithiated Cathodes.

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    The first-ever demonstration of stabilized Si/lithium-manganese-rich full cells, capable of retaining >90% energy over early cycling and >90% capacity over more than 750 cycles at the 1C rate (100% depth-of-discharge), is made through the utilization of a modified ionic-liquid electrolyte capable of forming a favorable cathode-electrolyte interface
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