EXPERIMENTAL QUANTIFICATION OF THE SOLIDS FLUX IN AN INTERNALLY CIRCULATING FLUIDIZED BED

Internally circulating fluidized beds (ICFBs) have been applied to a number of processes and provide a means of exchanging the bed particles from one reaction chamber to the other. Fundamental to this system is a good knowledge of the solids circulation rate (SRR). This paper summarises experimental investigations conducted using a hot tracer technique to measure the solids recirculation flux through an ICFB with a reaction and heat exchange chamber. Possible predictive models which link the bed hydrodynamics to the SRR are also evaluated

Correlação genótipo-fenótipo em pacientes brasileiras com síndrome de Rett

BACKGROUND: Rett syndrome (RS) is a severe neurodevelopmental X-linked dominant disorder caused by mutations in the MECP2 gene. PURPOSE: To search for point mutations on the MECP2 gene and to establish a correlation between the main point mutations found and the phenotype. METHOD: Clinical evaluation of 105 patients, following a standard protocol. Detection of point mutations on the MECP2 gene was performed on peripheral blood DNA by sequencing the coding region of the gene. RESULTS: Classical RS was seen in 68% of the patients. Pathogenic point mutations were found in 64.1% of all patients and in 70.42% of those with the classical phenotype. Four new sequence variations were found, and their nature suggests patogenicity. Genotype-phenotype correlations were performed. CONCLUSION: Detailed clinical descriptions and identification of the underlying genetic alterations of this Brazilian RS population add to our knowledge of genotype/phenotype correlations, guiding the implementation of mutation searching programs.INTRODUÇÃO: A síndrome de Rett é uma grave doença do neurodesenvolvimento ligada ao X dominante, causada por mutações no gene MECP2. OBJETIVOS: Identificar mutações de ponto no gene MECP2 e estabelecer uma correlação entre as principais mutações encontradas e o fenótipo. MÉTODO: Avaliação clínica de 105 pacientes, seguindo um protocolo estabelecido. A identificação de mutações de ponto foi realizada em DNA de sangue periférico por sequenciamento da região codificante do gene amplificada por PCR. RESULTADOS: Em 68% dos pacientes observou-se o quadro clássico da síndrome. Mutações de ponto patogênicas foram encontradas em 64,1% dos pacientes e em 70,42% das pacientes com o quadro clássico. Quatro novas variações de seqüência foram identificadas e sua natureza sugere patogenicidade. Correlações genótipo-fenótipo foram estabelecidas. CONCLUSÃO: Descrições clínicas detalhadas desta população brasileira de pacientes acrescenta conhecimento às correlações genótipo-fenótipo nesta grave condição, que podem auxiliar na implantação de programas de triagem de mutações

Theory of monolayers with boundaries: Exact results and Perturbative analysis

Domains and bubbles in tilted phases of Langmuir monolayers contain a class of textures knows as boojums. The boundaries of such domains and bubbles may display either cusp-like features or indentations. We derive analytic expressions for the textures within domains and surrounding bubbles, and for the shapes of the boundaries of these regions. The derivation is perturbative in the deviation of the bounding curve from a circle. This method is not expected to be accurate when the boundary suffers large distortions, but it does provide important clues with regard to the influence of various energetic terms on the order-parameter texture and the shape of the domain or bubble bounding curve. We also look into the effects of thermal fluctuations, which include a sample-size-dependent effective line tension.Comment: replaced with published version, 21 pages, 16 figures include

Linear stability analysis of transverse dunes

Sand-moving winds blowing from a constant direction in an area of high sand availability form transverse dunes, which have a fixed profile in the direction orthogonal to the wind. Here we show, by means of a linear stability analysis, that transverse dunes are intrinsically unstable. Any along-axis perturbation on a transverse dune amplify in the course of dune migration due to the combined effect of two main factors, namely: the lateral transport through avalanches along the dune's slip-face, and the scaling of dune migration velocity with the inverse of the dune height. Our calculations provide a quantitative explanation for recent observations from experiments and numerical simulations, which showed that transverse dunes moving on the bedrock cannot exist in a stable form and decay into a chain of crescent-shaped barchans.Comment: 8 pages, 4 figure

Plasma Extracellular Vesicle-Derived TIMP-1 mRNA as a Prognostic Biomarker in Clear Cell Renal Cell Carcinoma:A Pilot Study

The tumor microenvironment has gained a lot of attention from the scientific community since it has a proven impact in the development of tumor progression and metastasis. Extracellular vesicles (EVs) are now considered one of the key players of tumor microenvironment modulation. Clear cell renal cell carcinoma (ccRCC) is the most lethal urological neoplasia and presents a high metastatic potential, which reinforces the need for the development of more effective predictive biomarkers. Our goal was to evaluate the applicability of EV-derived matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as prognostic biomarkers for ccRCC. To do so, we studied the plasma EV content of 32 patients with localized ccRCC and 29 patients with metastatic ccRCC. We observed that patients with localized disease and tumors larger than 7 cm presented higher levels of plasma EV-derived TIMP-1 mRNA when compared with patients presenting smaller tumors (p = 0.020). Moreover, patients with metastatic disease presented higher levels of EV-derived TIMP-1 mRNA when compared with patients with localized disease (p = 0.002) and when we stratified those patients in high and low levels of TIMP-1 EV-derived mRNA, the ones presenting higher levels had a lower overall survival (p = 0.030). EV-derived TIMP-1 mRNA may be a good prognostic biomarker candidate for ccRCC

Adipose Tissue Omega-3 and Omega-6 Fatty Acid Content and Breast Cancer in the EURAMIC Study

The fatty acid content of adipose tissue in postmenopausal breast cancer cases and controls from five European countries in the European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Cancer (EURAMIC) breast cancer study (1991 -1992) was used to explore the hypothesis that fatty acids of the omega-3 family inhibit breast cancer and that the degree of inhibition depends on background levels of omega-6 polyunsaturates. Considered in isolation, the level of omega-3 or omega-6 fat in adipose tissue displayed little consistent association with breast cancer across study centers. The ratio of long-chain omega-3 fatty acids to total omega-6 fat showed an inverse association with breast cancer in four of five centers. In Malaga, Spain, the odds ratio for the highest tertile relative to the lowest reached 0.32 (95% confidence interval 0.13-0.82). In this center, total omega-6 fatty acid was strongly associated with breast cancer. With all centers pooled, the odds ratio for long-chain omega-3 to total omega-6 reached 0.80 for the second tertile and 0.65 for the third tertile, a downward trend bordering on statistical significance (p for trend = 0.055). While not definitive, these results provide evidence for the hypothesis that the balance between omega-3 and omega-6 fat may play a rolein breast cancer. Am J Epidemiol 1998; 147: 342-5

Lycopene and Myocardial Infarction Risk in the EURAMIC Study

A multicenter case-control study was conducted to evaluate the relations between antioxidant status assessed by biomarkers and acute myocardial infarction. Incidence cases and frequency matched controls were recruited from 10 European countries to maximize the variance in exposure within the study. Adipose tissue needle aspiration biopsies were taken shortly after the infarction and analyzed for levels of carotenoids and tocopherols. An examination of colinearity including all covariates and the three carotenoids, α-carotene, β-carotene, and lycopene, showed that the variables were sufficiently independent to model simultaneously. When examined singularly, each of the carotenoids appeared to be protective. Upon simultaneous analyses of the carotenoids, however, using conditional logistic regression models that controlled for age, body mass index, socioeconomic status, smoking, hypertension, and maternal and paternal history of disease, lycopene remained independently protective, with an odds ratio of 0.52 for the contrast of the 10th and 90th percentiles (95% confidence interval 0.33-0.82, p= 0.005). The associations for α- and β-carotene were largely eliminated. We conclude that lycopene, or some substance highly correlated which is in a common food source, may contribute to the protective effect of vegetable consumption on myocardial infarction ris

Stress Physiology of Lactic Acid Bacteria

Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.</p