646 research outputs found
Atmospheric scattering - state of the art
Atmospheric scattering is the natural phenomenon mainly responsible for the colours we observe in the sky. Over the years, several realistic computer graphics algorithms have been proposed in order to reproduce these colours. This state of the art is motivated by the large amount of scattered information, and by its great potential usage in a wide range of applications like flight simulators, video games and movies. This paper will cover the most important models and will present their evolution over the years. The first part contains a small introduction to the mechanics behind the light scattering phenomena. The second part will cover the earlier models, very much focused in the physical phenomenon. The third section will cover GPU based models, more focused on performance.Fundação para a Ciência e a Tecnologia (FCT
Abortos por Trypanosoma vivax no Pantanal Mato-Grossense e Bolívia.
Existe um elevado número de espécies de tripanosomas descritos na literatura que infectam animais (Hoare, 1972; Clarkson, 1976; Desquesnes, 1997; Dávila, 2002). Porém, entre os tripanosomas que infectam animais de interesse na pecuária podemos citar: Trypanosoma vivax; T. evansi; T. equiperdum e T. theileri. O T. evansi tem ampla distribuição nas Américas, sendo encontrado no Panamá, Venezuela, Colômbia, Brasil, Bolívia, Paraguai, Argentina e Peru. O T. evansi e o T. vivax são um risco potencial para mais de 500 milhões de bovinos e 100 milhões de búfalos (Peregrine, 1994). Várias são as doenças que interferem no processo reprodutivo de animais domésticos. Dentre as enfermidades que provocam aborto e concorrem para a menor produtividade na fase de cria pode-se considerar a infecção pelo Trypanosoma vivax, tanto em bovinos (Seidl et al., 1999), quanto em ovinos (Bawa et al., 2000).bitstream/CPAP/55975/1/DOC75.pdfFormato Eletrônic
Contemporary characteristics and outcomes in chagasic heart failure compared with other nonischemic and ischemic cardiomyopathy
Background: Chagas’ disease is an important cause of cardiomyopathy in Latin America. We aimed to compare clinical characteristics and outcomes in patients with heart failure (HF) with reduced ejection fraction caused by Chagas’ disease, with other etiologies, in the era of modern HF therapies.
Methods and Results: This study included 2552 Latin American patients randomized in the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) and ATMOSPHERE (Aliskiren Trial to Minimize Outcomes in Patients With Heart Failure) trials. The investigator-reported etiology was categorized as Chagasic, other nonischemic, or ischemic cardiomyopathy. The outcomes of interest included the composite of cardiovascular death or HF hospitalization and its components and death from any cause. Unadjusted and adjusted Cox proportional hazards models were performed to compare outcomes by pathogenesis. There were 195 patients with Chagasic HF with reduced ejection fraction, 1300 with other nonischemic cardiomyopathy, and 1057 with ischemic cardiomyopathy. Compared with other etiologies, Chagasic patients were more often female, younger, and had lower prevalence of hypertension, diabetes mellitus, and renal impairment (but had higher prevalence of stroke and pacemaker implantation) and had worse health-related quality of life. The rates of the composite outcome were 17.2, 12.5, and 11.4 per 100 person-years for Chagasic, other nonischemic, and ischemic patients, respectively—adjusted hazard ratio for Chagasic versus other nonischemic: 1.49 (95% confidence interval, 1.15–1.94; P=0.003) and Chagasic versus ischemic: 1.55 (1.18–2.04; P=0.002). The rates of all-cause mortality were also higher.
Conclusions: Despite younger age, less comorbidity, and comprehensive use of conventional HF therapies, patients with Chagasic HF with reduced ejection fraction continue to have worse quality of life and higher hospitalization and mortality rates compared with other etiologies.
Clinical Trial Registration: PARADIGM-HF: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255; ATMOSPHERE: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00853658
Association of single nucleotide polymorphisms in Pre-miR-27a, Pre-miR-196a2, Pre-miR-423, miR-608 and Pre-miR-618 with breast cancer susceptibility in a South American population
Indexación: Web of ScienceBackground
MicroRNAs (miRNAs) are a novel class of endogenous, non-coding, single-stranded RNAs capable of regulating gene expression by suppressing translation or degrading mRNAs. Single nucleotide polymorphisms (SNP) can alter miRNA expression, resulting in diverse functional consequences. Previous studies have examined the association of miRNA SNPs with breast cancer (BC) susceptibility. The contribution of miRNA gene variants to BC susceptibility in South American women had been unexplored. Our study evaluated the association of the SNPs rs895819 in pre-miR27a, rs11614913 in pre-miR-196a2, rs6505162 in pre-miR-423, rs4919510 in miR-608, and rs2682818 in pre-mir-618 with familial BC and early-onset non-familial BC in non-carriers of BRCA1/2 mutations from a South American population.
Results
We evaluated the association of five SNPs with BC risk in 440 cases and 807 controls. Our data do not support an association of rs11614913:C > T and rs4919510:C > G with BC risk. The rs6505162:C > A was significantly associated with increased risk of familial BC in persons with a strong family history of BC (OR = 1.7 [95 % CI 1.0–2.0] p = 0.05). The rs2682818:C > A genotype C/A is associated with an increased BC risk in non-familial early-onset BC. For the rs895819:A > G polymorphism, the genotype G/G is significantly associated with reduced BC risk in families with a moderate history of BC (OR = 0.3 [95 % CI 0.1–0.8] p = 0.01).
Conclusions
The contribution of variant miRNA genes to BC in South American women had been unexplored. Our findings support the following conclusions: a) rs6505162:C > A in pre-miR-423 increases risk of familial BC in families with a strong history of BC; b) the C/A genotype at rs2682818:C > A (pre-miR-618) increases BC risk in non-familial early-onset BC; and c) the G/G genotype at rs895819:A > G (miR-27a) reduces BC risk in families with a moderate history of BC.http://bmcgenet.biomedcentral.com/articles/10.1186/s12863-016-0415-
NEFRECTOMIA PARCIAL – A EXPERIÊNCIA DE 10 ANOS DO HOSPITAL DE SANTO ANTÓNIO
A nefrectomia parcial (NP) é uma técnica reconhecida no tratamento de diferentes patologias renais,nomedamente na oncológica.
Os autores apresentam a sua casuística dos últimos 10 anos, com avaliação dos índices de recorrência e sobrevivência
LIGHTCURVE ANALYSIS OF FOUR ASTEROIDS
From June 2011 through May 2012 May, photometric data for four asteroids were obtained using the Southeastern Association for Research in Astronomy (SARA) telescope located at the Kitt Peak National Observatory. The following synodic periods were found: 4808 Ballaero, P = 8.8976 ± 0.0007 h; 7750 McEwen, P = 27.82 ± 0.01 h; 11941 Archinal, P = 2.717 ±0.006 h; and (47035) 1998WS, P = 7.996 ± 0.001 h
Caracterização da deleção do gene pgk em uma cepa vacinal geneticamente modificada de Brucella abortus.
Neste trabalho objetiva-se expressar o gene pgk de B. abortus para a caracterização da cepa vacinal geneticamente modificada de B. abortus, 2308Δpgk, e utilização da proteína PGK em testes sorológicos
Sympathetic hyperactivity differentially affects skeletal muscle mass in developing heart failure: role of exercise training
Bacurau AV, Jardim MA, Ferreira JC, Bechara LR, Bueno CR Jr, Alba-Loureiro TC, Negrao CE, Casarini DE, Curi R, Ramires PR, Moriscot AS, Brum PC. Sympathetic hyperactivity differentially affects skeletal muscle mass in developing heart failure: role of exercise training. J Appl Physiol 106: 1631-1640, 2009. First published January 29, 2009; doi:10.1152/japplphysiol.91067.2008.-Sympathetic hyperactivity (SH) is a hallmark of heart failure (HF), and several lines of evidence suggest that SH contributes to HF-induced skeletal myopathy. However, little is known about the influence of SH on skeletal muscle morphology and metabolism in a setting of developing HF, taking into consideration muscles with different fiber compositions. the contribution of SH on exercise tolerance and skeletal muscle morphology and biochemistry was investigated in 3- and 7-mo-old mice lacking both alpha(2A)- and alpha(2C)-adrenergic receptor subtypes (alpha(2A)/alpha(2C)ARKO mice) that present SH with evidence of HF by 7 mo. To verify whether exercise training (ET) would prevent skeletal muscle myopathy in advanced-stage HF, alpha(2A)/alpha(2C)ARKO mice were exercised from 5 to 7 mo of age. At 3 mo, alpha(2A)/alpha(2C)ARKO mice showed no signs of HF and preserved exercise tolerance and muscular norepinephrine with no changes in soleus morphology. in contrast, plantaris muscle of alpha(2A)/alpha(2C)ARKO mice displayed hypertrophy and fiber type shift (IIA -> IIX) paralleled by capillary rarefaction, increased hexokinase activity, and oxidative stress. At 7 mo, alpha(2A)/alpha(2C)ARKO mice displayed exercise intolerance and increased muscular norepinephrine, muscular atrophy, capillary rarefaction, and increased oxidative stress. ET reestablished alpha(2A)/alpha(2C)ARKO mouse exercise tolerance to 7-mo-old wild-type levels and prevented muscular atrophy and capillary rarefaction associated with reduced oxidative stress. Collectively, these data provide direct evidence that SH is a major factor contributing to skeletal muscle morphological changes in a setting of developing HF. ET prevented skeletal muscle myopathy in alpha(2A)/alpha(2C)ARKO mice, which highlights its importance as a therapeutic tool for HF.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Dept Biodinam Movimento Corpo Humano, Escola Educacao Fis & Esporte, BR-05508900 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 São Paulo, BrazilUniv São Paulo, Sch Med, Heart Inst InCor, BR-05508900 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilFAPESP: 2005/59740-7FAPESP: 2003/10442-9FAPESP: 2006/56321-6CNPq: 473061/2006-6Web of Scienc
Biological response to pre-mineralized starch based scaffolds for bone tissue engineering
It is known that calcium-phosphate (Ca-P) coatings are able not only to improve the bone
bonding behaviour of polymeric materials, but at the same time play a positive role on
enhancing cell adhesion and inducing the differentiation of osteoprogenitor cells. Recently
an innovative biomimetic methodology, in which a sodium silicate gel was used as a
nucleative agent, was proposed as an alternative to the currently available biomimetic
coating methodologies. This methodology is especially adequate for coating biodegradable
porous scaffolds. In the present work we evaluated the influence of the referred to
treatment on the mechanical properties of 50/50 (wt%) blend of corn starch/ethylene-vinyl
alcohol (SEVA-C) based scaffolds. These Ca-P coated scaffolds presented a compressive
modulus of 224.6 ± 20.6 and a compressive strength of 24.2 ± 2.20. Cytotoxicity evaluation
was performed according ISO/EN 10993 part 5 guidelines and showed that the biomimetic
treatment did not have any deleterious effect on L929 cells and did not inhibit cell growth.
Direct contact assays were done by using a cell line of human osteoblast like cells (SaOS-2).
3 × 105 cells were seeded per scaffold and allowed to grow for two weeks at 37 ◦C in a
humidified atmosphere containing 5% CO2. Total protein quantification and scanning
electron microscopy (SEM) observation showed that cells were able to grow in the
pre-mineralized scaffolds. Furthermore cell viability assays (MTS test) also show that cells
remain viable after two weeks in culture. Finally, protein expression studies showed that
after two weeks osteopontin and collagen type I were being expressed by SaOS-2 cells
seeded on the pre-mineralized scaffolds. Moreover, alkaline phosphatase (ALP) activity was
higher in the supernatants collected from the pre-mineralized samples, when compared to
the control samples (non Ca-P coated). This may indicate that a faster mineralization of the
ECM produced on the pre-mineralized samples was occurring. Consequently, biomimetic
pre-mineralization of starch based scaffolds can be a useful route for applying these
materials on bone tissue engineering
Formation of bone-like apatite layer on chitosan fiber mesh scaffolds by a biomimetic spraying process
Bone-like apatite coating of polymeric substrates
by means of biomimetic process is a possible
way to enhance the bone bonding ability of the
materials. The created apatite layer is believed to have
an ability to provide a favorable environment for
osteoblasts or osteoprogenitor cells. The purpose of
this study is to obtain bone-like apatite layer onto
chitosan fiber mesh tissue engineering scaffolds, by
means of using a simple biomimetic coating process
and to determine the influence of this coating on
osteoblastic cell responses. Chitosan fiber mesh scaffolds
produced by a previously described wet spinning
methodology were initially wet with a Bioglass"–water
suspension by means of a spraying methodology and
then immersed in a simulated body fluid (SBF)
mimicking physiological conditions for one week. The
formation of apatite layer was observed morphologically
by scanning electron microscopy (SEM). As a
result of the use of the novel spraying methodology, a
fine coating could also be observed penetrating into the
pores, that is clearly within the bulk of the scaffolds.
Fourier Transform Infrared spectroscopy (FTIRATR),
Electron Dispersive Spectroscopy (EDS) and
X-ray diffraction (XRD) analysis also confirmed the
presence of apatite-like layer. A human osteoblast-like
cell line (SaOs-2) was used for the direct cell contact assays. After 2 weeks of culture, samples were observed
under the SEM. When compared to the control
samples (unmodified chitosan fiber mesh scaffolds) the
cell population was found to be higher in the Ca–P
biomimetic coated scaffolds, which indicates that the
levels of cell proliferation on this kind of scaffolds
could be enhanced. Furthermore, it was also observed
that the cells seeded in the Ca–P coated scaffolds have
a more spread and flat morphology, which reveals an
improvement on the cell adhesion patterns, phenomena
that are always important in processes such as
osteoconduction
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