36 research outputs found

    On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

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    In this report, a successful thermodynamical model was employed to understand the structural transition in Er5_5Si4_4, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a ΔF0=\Delta F_0 = -0.262 eV. Finally, it was achieved a variation of Seebeck coefficient (\sim 6 μ\muV) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

    Design and photo-Fenton performance of Graphene/CuS/Fe3O4 tertiary nanocomposites for Rhodamine B degradation

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    This study describes nanocomposites of graphene flakes (GF) combined with CuS, Fe3O4 and CuS−Fe3O4 nanoparticles prepared by wet chemical methods. The Fe3O4 and/or CuS nanoparticles were directly anchored onto GF without requiring additional chemical treatment. The composition, structure and morphology of the nanocomposites, as well as of the pristine GF and metal oxide/sulfide nanoparticles were characterised by X − ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), powder X − ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results confirmed the successful attachment of CuS nanophases (size range: 23.7–50.1 nm) and/or Fe3O4 nanoparticles (size range: 10.6–15.8 nm). The adsorption and photocatalytic properties of the GF−based nanocomposites were evaluated at room temperature using Rhodamine B (RhB) as a model contaminant. Theoretical models were fitted to the adsorption kinetic results using the pseudo-first-order, pseudo-second-order and Elovich equations, while the adsorption mechanism was determined using the intraparticle diffusion, Bangham and Boyd models. The RhB adsorption efficiency was 6.5% for GF@CuS−Fe3O4 after 180 min contact time, whereas for the other materials was significantly higher: 97.6%, 60.9% and 31.9% for GF, GF@CuS and GF@Fe3O4, respectively. The adsorption capacity of GF and composites fitted the pseudo−second−order kinetic and Elovich models. The influence of the nanostructures composition on the corresponding photocatalytic activity in the degradation of RhB under a 150 W halogen lamp was also evaluated. The GF@CuS−Fe3O4 nanocomposite totally eliminated the dissolved RhB after 60 min irradiation, whereas the GF@CuS, GF@Fe3O4 and pristine Fe3O4 removed 75.6%, 80.9% and 30.8%, respectively, after 180 min irradiation. It was found that the photocatalytic behaviour of the composites was best described by the first−order kinetic model. The rate constant of the photocatalytic RhB removal for GF@CuS−Fe3O4 (k = 7.05 ×10−2 min−1) was 2.1, 5.1 and 15.0 times higher than those obtained for GF@CuS, GF@Fe3O4 and pristine Fe3O4, respectively, after 60 min of visible light irradiation.publishe

    Expression and Function of Ccbe1 in the Chick Early Cardiogenic Regions Are Required for Correct Heart Development

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    During the course of a differential screen to identify transcripts specific for chick heart/hemangioblast precursor cells, we have identified Ccbe1 (Collagen and calcium-binding EGF-like domain 1). While the importance of Ccbe1 for the development of the lymphatic system is now well demonstrated, its role in cardiac formation remained unknown. Here we show by whole-mount in situ hybridization analysis that cCcbe1 mRNA is initially detected in early cardiac progenitors of the two bilateral cardiogenic fields (HH4), and at later stages on the second heart field (HH9-18). Furthermore, cCcbe1 is expressed in multipotent and highly proliferative cardiac progenitors. We characterized the role of cCcbe1 during early cardiogenesis by performing functional studies. Upon morpholino-induced cCcbe1 knockdown, the chick embryos displayed heart malformations, which include aberrant fusion of the heart fields, leading to incomplete terminal differentiation of the cardiomyocytes. cCcbe1 overexpression also resulted in severe heart defects, including cardia bifida. Altogether, our data demonstrate that although cardiac progenitors cells are specified in cCcbe1 morphants, the migration and proliferation of cardiac precursors cells are impaired, suggesting that cCcbe1 is a key gene during early heart development.FCT [SFRH/BD/65628/2009, SFRH/BPD/86497/2012, SFRH/BPD/41081/2007]; F.C.T.B.I. fellowship [PTDC/SAU-BID/114902/ 2009]; FCT; Institute for Biotechnology Bioengineering (Centro Biomedicina Molecular e Celular (IBB/CBME), Laboratorio Associado (LA) in the frame of Project [PestOE/EQB/LA0023/2013]info:eu-repo/semantics/publishedVersio

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Burden of non-communicable diseases among adolescents aged 10–24 years in the EU, 1990–2019: a systematic analysis of the Global Burden of Diseases Study 2019

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    Background Disability and mortality burden of non-communicable diseases (NCDs) have risen worldwide; however, the NCD burden among adolescents remains poorly described in the EU. Methods Estimates were retrieved from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Causes of NCDs were analysed at three different levels of the GBD 2019 hierarchy, for which mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) were extracted. Estimates, with the 95% uncertainty intervals (UI), were retrieved for EU Member States from 1990 to 2019, three age subgroups (10–14 years, 15–19 years, and 20–24 years), and by sex. Spearman's correlation was conducted between DALY rates for NCDs and the Socio-demographic Index (SDI) of each EU Member State. Findings In 2019, NCDs accounted for 86·4% (95% uncertainty interval 83·5–88·8) of all YLDs and 38·8% (37·4–39·8) of total deaths in adolescents aged 10–24 years. For NCDs in this age group, neoplasms were the leading causes of both mortality (4·01 [95% uncertainty interval 3·62–4·25] per 100 000 population) and YLLs (281·78 [254·25–298·92] per 100 000 population), whereas mental disorders were the leading cause for YLDs (2039·36 [1432·56–2773·47] per 100 000 population) and DALYs (2040·59 [1433·96–2774·62] per 100 000 population) in all EU Member States, and in all studied age groups. In 2019, among adolescents aged 10–24 years, males had a higher mortality rate per 100 000 population due to NCDs than females (11·66 [11·04–12·28] vs 7·89 [7·53–8·23]), whereas females presented a higher DALY rate per 100 000 population due to NCDs (8003·25 [5812·78–10 701·59] vs 6083·91 [4576·63–7857·92]). From 1990 to 2019, mortality rate due to NCDs in adolescents aged 10–24 years substantially decreased (–40·41% [–43·00 to –37·61), and also the YLL rate considerably decreased (–40·56% [–43·16 to –37·74]), except for mental disorders (which increased by 32·18% [1·67 to 66·49]), whereas the YLD rate increased slightly (1·44% [0·09 to 2·79]). Positive correlations were observed between DALY rates and SDIs for substance use disorders (rs=0·58, p=0·0012) and skin and subcutaneous diseases (rs=0·45, p=0·017), whereas negative correlations were found between DALY rates and SDIs for cardiovascular diseases (rs=–0·46, p=0·015), neoplasms (rs=–0·57, p=0·0015), and sense organ diseases (rs=–0·61, p=0·0005)

    Key Parameters in Phototherapy with Gold Nanorods Using Continuous Near Infrared Radiation

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    Abstract As nanoparticle formulations move toward human clinical trials in photothermal cancer therapy (PTT), the influence of individual key parameters on the heating efficacy must be thoroughly assessed. This work reports a systematic study on the heating performance of gold nanorods during exposure to near‐infrared radiation, evaluating the influence of nanorods concentration, total volume, laser output power, and spot area. Interestingly, the lowest concentration tested (24 µg mL−1) shows the most promising results with a SAR (Specific Absorption Rate) value of 24.6 kW gAu−1 for the highest laser power (0.8 W), spot area (0.4 cm2), volume (1 mL). The laser output power and concentration proved to be the key parameters in global heating of the sample. The cuvette's optical path length also proves to be an important parameter given that there is a threshold concentration value beyond which no significant improvement will be observed, and the higher gold mass will play a detrimental role suppressing SAR values. It is experimentally demonstrated that the multi‐parameter exploration can lead to a finer control of the performance in PTT, opening a pathway for efficient heating of low nanoparticle concentrations

    Desenvolvimento de um sistema de estimativa da evapotranspiração de referência

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    Neste trabalho, apresenta-se um programa computacional denominado SEVAP (Sistema de Estimativa da Evapotranspiração) com o objetivo de se estimar a evapotranspiração através de oito métodos. Os métodos indicados no programa são: Penman-Monteith, Hargreaves, Jensen-Haise, Linacre, Makkink, Priestley & Taylor, Tanque Classe A e Thornthwaite. A eficiência do SEVAP foi avaliada com a aplicação dos dados da estação Meteorológica de Petrolina, PE, referentes ao ano 2002. Foram utilizados as médias mensais desse ano e os valores diários dos meses de março e agosto, do mesmo ano, das seguintes variáveis meteorológicas: temperaturas máxima e mínima do ar, umidade relativa do ar, insolação, velocidade do vento, evaporação do Tanque Classe A e radiação solar global. Os resultados evidenciam que o modelo SEVAP possibilita estimativas confiáveis e contínuas da evapotranspiração de referência; além disso, ele pode ser utilizado no monitoramento local e regional da evapotranspiração potencial, em escala diária ou mensal. Na ausência dos dados de insolação e de velocidade do vento, o método de Penman-Monteith pode ser substituído pelo método de Hargreaves
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