352 research outputs found

    Simultaneous transfer of cholesterol, triglycerides, and phospholipids to high-density lipoprotein in aging subjects with or without coronary artery disease

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    OBJECTIVE: To verify whether the capacity of high-density lipoprotein (HDL) to simultaneously receive nonesterified cholesterol, triglycerides, cholesteryl esters, and phospholipids changes with aging and the presence of coronary artery disease. DESIGN: Cross-sectional study with biochemical analyses. SUBJECTS: Eleven elderly patients with coronary artery disease (74±5 years) were compared with the following groups of non-coronary artery disease subjects (referred to as "healthy"): 25 young (25±5 years), 25 middle-aged (42± years), and 25 elderly subjects (75±8 years). METHODS: Plasma samples were incubated with a nanoemulsion labeled with radioactive lipids; the transfer of the lipids from the nanoemulsion to the HDL was measured in chemically precipitated HDL. HDL size and paraoxonase-1 activity were also determined. RESULTS: The transfer of cholesteryl esters and phospholipids to high-density lipoprotein was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. Non-esterified cholesterol and triglyceride transfer was not different among these three groups. The HDL size was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. The paraoxonase-1 activity was similar among the groups. Compared with healthy elderly subjects, coronary artery disease elderly subjects had significantly less (p<0.05) transfer of non-esterified cholesterol, triglycerides, and cholesteryl esters to the HDL and a significantly smaller (p<0.05) HDL size. CONCLUSION: Because lipid transfer is enhanced in healthy elderly subjects but not in those with coronary artery disease, increasing lipid transfer to HDL may be a protective mechanism against the disease

    A Horseshoe Pit mixture model for Bayesian screening with an application to light sheet fluorescence microscopy in brain imaging

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    Finding parsimonious models through variable selection is a fundamental problem in many areas of statistical inference. Here, we focus on Bayesian regression models, where variable selection can be implemented through a regularizing prior imposed on the distribution of the regression coefficients. In the Bayesian literature, there are two main types of priors used to accomplish this goal: the spike-and-slab and the continuous scale mixtures of Gaussians. The former is a discrete mixture of two distributions characterized by low and high variance. In the latter, a continuous prior is elicited on the scale of a zero-mean Gaussian distribution. In contrast to these existing methods, we propose a new class of priors based on discrete mixture of continuous scale mixtures providing a more general framework for Bayesian variable selection. To this end, we substitute the observation-specific local shrinkage parameters (typical of continuous mixtures) with mixture component shrinkage parameters. Our approach drastically reduces the number of parameters needed and allows sharing information across the coefficients, improving the shrinkage effect. By using half-Cauchy distributions, this approach leads to a cluster-shrinkage version of the Horseshoe prior. We present the properties of our model and showcase its estimation and prediction performance in a simulation study. We then recast the model in a multiple hypothesis testing framework and apply it to a neurological dataset obtained using a novel whole-brain imaging technique

    {6,6′-Dibromo-4,4′-dichloro-2,2′-[o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}nickel(II)

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    In the title complex, [Ni(C20H10Br2Cl2N2O2)], the NiII ion is coordinated by two phen­oxy O atoms and two imino N atoms of the tetradentate ligand, forming a slightly distorted square-planar environment. The mol­ecule is essentially planar, with an r.m.s. deviation of 0.088 Å for the mean plane defined by all non-H atoms in the mol­ecule

    Institutionalization of the sciences, gender system, and scientific production in Brazil (1939-1969)

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    Thanks to policies put in place in the 1930s, women's experiences in higher education increased their professional participation in the academic and scientific worlds. Largely neglected in Brazilian historiography of the sciences, analysis of this phenomenon introduces a new perspective on the meaning of institutionalization and professionalization of scientific activities, a process in which women have played an authentic role. We explore their presence by analyzing the scientific production published in four journals between 1939 and 1969. Gender differences are detected according to the standard of the publication.15S437

    CALCULATING BEDLOAD TRANSPORT IN RIVERS: CONCEPTS, CALCULUS ROUTINES AND APPLICATION

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    Rivers are immensely important to human activities such as water supply, navigation, energy generation, and agriculture. They are also an important morphodynamic agent of erosion, transport and deposition. Their capacity to transport sediment depends on their hydraulic characteristics and can be predicted by mathematical models. Several mathematical models can be used to compute bed-load transport. Each one is appropriately better for certain conditions. In this paper, we present an application built in Microsoft Excel to compute the bed-load transport in rivers based on the Van Rijn mathematical model. The Van Rijn model is appropriate for rivers transporting sandy sediments in conditions of subcritical flow. Hydraulic parameters such as channel slope, stream power, and Reynolds and Froude numbers can be calculated using the application proposed here. The application was tested in the Parana River and results from the calculations are consistent with data obtained from fieldwork surveys. The error of the application was only 20%, which shows good agreement of the model with survey values.CNPqMato Grosso do Sul Research FoundationSao Paulo Research FoundationNational Council of Technological and Scientific DevelopmentCAPESSao Paulo Research Foundation (FAPESP)Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Ave 24A,1515, BR-13506900 Rio Claro, SP, BrazilUniv Fed Mato Grosso do Sul, Dept Geog, Ave Rio Branco 1270, BR-79304902 Corumba, MS, BrazilUniv Fed Sao Paulo, Dept Ciencias Ambientais, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilUniv Kentucky, Dept Earth & Environm Sci, 101 Slone Res Bldg, Lexington, KY 40506 USAUniv Fed Sao Paulo, Dept Ciencias Ambientais, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilCNPq: 140334/2015-7CNPq: 308563/2013-1CNPq: 312386/2014-1FUNDECT/CNPq: 083/2016]FAPESP: 2007/55987-3FAPESP: 2014/06889-2CNPq: 443437/2014-9CNPq: 447402/2014-5CAPES: 140334/2015-7CAPES: 308563/2013-1CAPES: 312386/2014-1FAPESP: 2014/23334-4Web of Scienc

    Lee Silverman Voice Treatment versus standard speech and language therapy versus control in Parkinson’s disease: a pilot randomised controlled trial (PD COMM pilot)

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    Background: Speech-related problems are common in Parkinson’s disease (PD), but there is little evidence for the effectiveness of standard speech and language therapy (SLT) or Lee Silverman Voice Treatment (LSVT LOUD®). Methods: The PD COMM pilot was a three-arm, assessor-blinded, randomised controlled trial (RCT) of LSVT LOUD®, SLT and no intervention (1:1:1 ratio) to assess the feasibility and to inform the design of a full-scale RCT. Non-demented patients with idiopathic PD and speech problems and no SLT for speech problems in the past 2 years were eligible. LSVT LOUD® is a standardised regime (16 sessions over 4 weeks). SLT comprised individualised content per local practice (typically weekly sessions for 6–8 weeks). Outcomes included recruitment and retention, treatment adherence, and data completeness. Outcome data collected at baseline, 3, 6, and 12 months included patient-reported voice and quality of life measures, resource use, and assessor-rated speech recordings. Results: Eighty-nine patients were randomised with 90% in the therapy groups and 100% in the control group completing the trial. The response rate for Voice Handicap Index (VHI) in each arm was ≥ 90% at all time-points. VHI was highly correlated with the other speech-related outcome measures. There was a trend to improvement in VHI with LSVT LOUD® (difference at 3 months compared with control: − 12.5 points; 95% CI − 26.2, 1.2) and SLT (difference at 3 months compared with control: − 9.8 points; 95% CI − 23.2, 3.7) which needs to be confirmed in an adequately powered trial. Conclusion: Randomisation to a three-arm trial of speech therapy including a no intervention control is feasible and acceptable. Compliance with both interventions was good. VHI and other patient-reported outcomes were relevant measures and provided data to inform the sample size for a substantive trial

    Mechanotransduction and growth factor signalling to engineer cellular microenvironments

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    Engineering cellular microenvironments involves biochemical factors, the extracellular matrix (ECM) and the interaction with neighbouring cells. This progress report provides a critical overview of key studies that incorporate growth factor (GF) signalling and mechanotransduction into the design of advanced microenvironments. Materials systems have been developed for surface-bound presentation of GFs, either covalently tethered or sequestered through physico-chemical affinity to the matrix, as an alternative to soluble GFs. Furthermore, some materials contain both GF and integrin binding regions and thereby enable synergistic signalling between the two. Mechanotransduction refers to the ability of the cells to sense physical properties of the ECM and to transduce them into biochemical signals. Various aspects of the physics of the ECM, i.e. stiffness, geometry and ligand spacing, as well as time-dependent properties, such as matrix stiffening, degradability, viscoelasticity, surface mobility as well as spatial patterns and gradients of physical cues are discussed. To conclude, various examples illustrate the potential for cooperative signalling of growth factors and the physical properties of the microenvironment for potential applications in regenerative medicine, cancer research and drug testing

    An in vivo study of the host response to starch-based polymers and composites subcutaneously implanted in rats

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    Implant failure is one of the major concerns in the biomaterials field. Several factors have been related to the fail but in general these biomaterials do not exhibit comparable physical, chemical or biological properties to natural tissues and ultimately, these devices can lead to chronic inflammation and foreign-body reactions. Starch-based biodegradable materials and composites have shown promising properties for a wide range of biomedical applications as well as a reduced capacity to elicit a strong reaction from immune system cells in vitro. In this work, blends of corn starch with ethylene vinyl alcohol (SEVA-C), cellulose acetate (SCA) and polycaprolactone (SPCL), as well as hydroxyapatite (HA) reinforced starch-based composites, were investigated in vivo. The aim of the work was to assess the host response evoked for starch-based biomaterials, identifying the presence of key cell types. The tissues surrounding the implant were harvested together with the material and processed histologically for evaluation using immunohistochemistry. At implant retrieval there was no cellular exudate around the implants and no macroscopic signs of an inflammatory reaction in any of the animals. The histological analysis of the sectioned interface tissue after immunohistochemical staining using ED1, ED2, CD54, MHC class II and a/b antibodies showed positively stained cells for all antibodies, except for a/b for all the implantation periods, where it was different for the various polymers and for the period of implantation. SPCL and SCA composites were the materials that stimulated the greatest cellular tissue responses, but generally biodegradable starch-based materials did not induce a severe reaction for the studied implantation times, which contrasts with other types of degradable polymeric biomaterials.Fundação para a Ciência e a Tecnologia (FCT
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