Modeling of piezoelectric energy harvesting considering the dependence of the rectifier circuit

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Recanalization Rates after Acute Deep Vein Thrombosis: A Single-center Experience Using a Newly Proposed Vein Diameter Variation Index

Background: Duplex ultrasound scanning (DUS) is the method of choice for diagnosis of deep vein thrombosis (DVT). However, only a few studies have performed prospective serial DUS after an acute episode of DVT to assess its evolution. This study aimed to report our experience using DUS combined with a thrombosis score (TS) and a newly proposed vein diameter variation index (VDVI) to evaluate the rate of resolution of DVT by assessing and quantifying the early stages of vein recanalization in proximal vein segments within 6 months after an episode of acute lower extremity DVT.Methods: Twelve patients with first episode of acute lower extremity DVT confirmed by DUS as occurring in <= 10 days after the onset of venous thrombosis symptoms were followed up prospectively for 6 months. TS and VDVI were calculated at 1, 3, and 6 months to assess vein recanalization. Intra-thrombus arteriovenous fistula formation was also investigated and related to the recanalization process.Results: Seven (58%) women were included, with a total cohort median age of 53.5 +/- 19 years. The left lower extremity was affected in 7 (58%) patients. DVT was diagnosed in 55 proximal vein segments. All patients had proximal DVT, with involvement of the external iliac, femoral, and popliteal veins. After 6 months, there was a significant decrease in TS and increase in VDVI (P < 0.001) in all proximal vein segments assessed, indicating thrombus regression. The more distal the DVT was, the faster was the VDVI increase, with most popliteal veins being recanalized at 3 months (P < 0.001). Intra-thrombus arteriovenous fistula was identified in 50% of patients at 1 month while on anticoagulation.Conclusions: The combined use of two different DUS-based assessment tools, TS and the proposed VDVI, provided an effective method to prospectively assess vein recanalization rates after an episode of acute lower extremity DVT in this series of patients and may allow a correct evaluation of DVT and its resolution or progression.

Photoluminescence activity of Ba1-xCaxTiO3: dependence on particle size and morphology

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of different mydriatics on intraocular pressure, pupil diameter, and ruminal and intestinal motility in healthy sheep

Objective To determine the effects of the administration of subconjunctival 1% atropine (SA), topical 1% atropine (A), 0.5% tropicamide (T), 1% homatropine (H), 10% phenylephrine (P), and 2% ibopamine (I) on intraocular pressure (IOP), pupil diameter (PD), ruminal motility (RM) and intestinal motility (IM) in sheep.Animal studied Ten spayed ewes of Santa Ines breed.Procedures Six experiments were performed separately at 1-week intervals. One eye was randomly selected and received one drop of A, T, H, P, I, or subconjunctival injection of atropine at 8 a. m. On the following days, IOP and PD were evaluated every 8 h until the pupil returned to its normal diameter. Ruminal motility and intestinal motility were evaluated only within the first 13 h.Results The IOP did not change significantly in the treated eyes compared with the control eyes and baseline at any time point (P > 0.05). A longer-lasting pupil dilation was observed after the administration of A (96 h), SA (79 h), H (24 h), and T (24 h). Within the first 30 min after treatment, RM and IM decreased, by 78% and 82% (H), 76% and 86% (SA), 46% and 58% (A), and 62% and 70% (T) (P < 0.001), respectively, with a tendency to return to baseline values following 13 h of drug administration. Both 10% phenylephrine and 2% ibopamine did not have any effect on the parameters evaluated (P > 0.05).Conclusions Topical and subconjunctival 1% atropine, 0.5% tropicamide, and 1% homatropine significantly reduced RM and IM, and induced pupil dilation but did not change IOP in eyes of healthy sheep. The sympathomimetics phenylephrine (10%) and ibopamine (2%) did not change the parameters evaluated.

Dependência espacial da estabilidade de agregados e matéria orgânica do solo em cambissolo sob cultivo de cana de açucar

The soil management system can modify the natural distribution of the soil attributes and, consequently, the variability of the soil aggregation and organic matter content. Thus, the aim of this work was to evaluate the aggregate stability and organic matter content spatial distribution on a Haplic Cambisol under sugar cane cultivation in the Southern Amazonas State, Brazil. A 70 x 70 m square mesh, with regular 10 meters intervals, was designed over the cultivation area, resulting in 64 sample points. Soil blocks with preserved structure were collected at 0.0-0.2 m depth in order to analyze the aggregate stability and organic matter content. The data were submitted to the descriptive and geostatistical analysis. The soil attributes presented a spatial dependence structure and the greater range was observed for the mean weighted diameter and aggregate class <1.00 mm. Also, there is a spatial relation among the mean geometric diameter, mean weighted diameter and aggregate classes (>2.00 and 2.00-1.00 mm).

Cultivo de milho verde em sucessão ao arroz no Vale do Ribeira, SP: subsídios para adoção de zonas de manejo

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

On the spatial and temporal dependence of CO2 emission on soil properties in sugarcane (Saccharum spp.) production

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect

Estimation of the lower flammability limits of C-H compounds at 25 degrees C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 degrees C H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C H compounds. When tested for a temperature range from 5 degrees C to 100 degrees C , the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene. (C) 2014 Elsevier B.V. All rights reserved.

Nicotine dependence and levels of depression and anxiety in smokers in the process of smoking cessation

Background: Depression and anxiety are psychiatric disorders that are related to tobacco use and associated with dependence, the process of cessation, lapses and relapses after quitting smoking. Objective: To analyze the association of nicotine dependence with the level of anxiety and depression in patients who are in the process of smoking cessation. Methods: Cross-sectional study conducted with patients who sought the smoking cessation program in Cuiabá/MT. All the smokers enrolled from May to August 2012, participated in this study. Four instruments were applied: Socio-demographic Questionnaire, Fagerstrom test, Beck Anxiety Inventory and Beck Depression Inventory. Following bivariate analysis, using the crude prevalence ratio, with level of significance lower than 5% (p < 0.05), having as variable outcome the nicotine dependence >= 5 (Fagerstrom). The associations with p < 0.20 were selected for robust Multiple Poisson Regression (RPa). Results: Associations of Fagerstrom >= 5 with the male sex (RP = 1.15 CI 95% 1.03-1.28); number of cigarettes/day (RP = 1,33; CI 95% 1.19-1.48); and moderate/severe level of depression (RP = 1.15; CI 95% 1.04-1.28) were found. In the final model (RPa), the following variables remained associated: male gender (RPa 1.12; CI 95% 1.01-1.24), number of cigarettes/day (RPa 1.28; CI 95% 1.15-1.43) and high level of depression (RPa 1.12; CI 95% 1.01-1.23). Discussion: High level of nicotine dependence was associated significantly with the level of depression, emphasizing the association between smoking and psychiatric comorbidities.

Dielectric properties of Sr0.75Ba0.25Nb 2O6 thin films: Bias field, frequency and temperature dependence

Ferroelectric strontium barium niobate solid solutions had received great attention due to their excellent pyroelectric, electrooptic and photorefractive properties. Furthermore, they usually also present very interesting phase transition characteristics. In this work, polycrystalline single phase Sr 0.75 Ba 0.25 Nb 2 O 6 thin films were prepared by a hybrid chemical method and deposited on Pt/Ti/SiO 2 /Si substrates. The temperature dependence of dielectric constant was measured at different frequencies and bias field levels. The presence of two dielectric dispersion regions with relaxor characteristics was observed at distinct temperature ranges, corresponding to the ferro-paraelectric and to a structural phase transition at low temperatures, respectively. A specific dielectric dispersion region, associated with an incommensurate superstructure frequently observed in bulk samples, was not observed in this films probably due to their small grain sizes. © 2002 Taylor & Francis.

Cellulose acetate membranes for osmosedimentation: Performance and morphological dependence on preparation conditions

Osmosedimentation is a new membrane-assisted separation technique, based on the rapid approach to sedimentation equilibrium when macromolecular solutions are contained within dialysis cells, in contact with solvent via a permselective membrane. Cellulose acetate membranes, cast from ternary solvent (acetone, acetic acid, water) solutions are suitable for osmosedimentation of proteins at low (2000 rpm) centrifugation speeds. Solute retention is improved when acetone-rich casting solutions are used. These membranes were examined by electron and optical microscopy, showing considerable morphological changes in the membrane support layer as the casting solution composition is changed. © 1986.

Temperature dependence of conformational properties of short polyelectrolytes from simulations at a single temperature

We use a series expansion method introduced recently by Rickman and Phillpot (Phys. Rev. Lett. 1991, 66, 349) to study the temperature dependent conformational properties of short ionized polyelectrolyte chains in ionic solutions by conducting simulations at a single temperature. The charged beads located at the sites of a cubic lattice interact through screened Coulombic interactions. It is shown that this method provides results that correlate with other Monte Carlo simulations, performed over a range of temperatures, where conformational transitions induced by thermal and screening effects occur. It is also shown that the method can be used successfully when the potential is weakly dependent on temperature. © 1994 American Chemical Society.

Características sociodemográficas e clínicas que afetam a qualidade de vida em pacientes estomizados intestinais

Pós-graduação em Enfermagem (mestrado profissional) - FMB

Temperature-Dependence of Cationic Lipid Bilayer Intermixing: Possible Role of Interdigitation

In this work, we investigated the properties of a fusogenic cationic lipid, diC14-amidine, and show that this lipid possesses per se the capacity to adopt either an interdigitated structure (below and around its transition temperature) or a lamellar structure (above the transition temperature). To provide experimental evidence of this lipid bilayer organization, phospholipids spin-labeled at different positions of the hydrocarbon chain were incorporated into the membrane and their electron spin resonance (ESR) spectra were recorded at different temperatures. For comparison, similar experiments were performed with dimyristoyl phosphatidylcholine, a zwitterionic lipid (DMPC) which adopts a bilayer organization over a broad temperature range. Lipid mixing between diC14-amidine and asolectin liposomes was more efficient below (10-15 degrees C) than above the transition temperature (above 25 degrees C). This temperature-dependent "fusogenic" activity of diC14-amidine liposomes is opposite to what has been observed so far for peptides or virus-induced fusion. Altogether, our data suggest that interdigitatiori is a highly fusogenic state and that interdigitation-mediated fusion occurs via an unusual temperature-dependent mechanism that remains to be deciphered.

Pressure Dependence of N-15 Chemical Shifts in Model Peptides Ac-Gly-Gly-X-Ala-NH2

High pressure NMR spectroscopy has developed into an important tool for studying conformational equilibria of proteins in solution. We have studied the amide proton and nitrogen chemical shifts of the 20 canonical amino acids X in the random-coil model peptide Ac-Gly-Gly-X-Ala-NH2, in a pressure range from 0.1 to 200 MPa, at a proton resonance frequency of 800 MHz. The obtained data allowed the determination of first and second order pressure coefficients with high accuracy at 283 K and pH 6.7. The mean first and second order pressure coefficients <B-1(15N)> and <B-2(15N)> for nitrogen are 2.91 ppm/GPa and -2.32 ppm/GPa(2), respectively. The corresponding values <B-1(1H)> and <B-2(1H)> for the amide protons are 0.52 ppm/GPa and -0.41 ppm/GPa(2). Residual dependent (1)J(1H15N)-coupling constants are shown.