Relative growth, morphological sexual maturity, and size of Macrobrachium amazonicum (Heller 1862) (Crustacea, Decapoda, Palaemonidae) in a population with an entirely freshwater life cycle

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

Structural and morphological characteristics of (Pb1-x Sr (x) )TiO3 powders obtained by polymeric precursor method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modeling and analysis of artificial neural networks applied in operations research

Artificial neural networks are dynamic systems consisting of highly interconnected and parallel nonlinear processing elements. Systems based on artificial neural networks have high computational rates due to the use of a massive number of these computational elements. Neural networks with feedback connections provide a computing model capable of solving a rich class of optimization problems. In this paper, a modified Hopfield network is developed for solving problems related to operations research. The internal parameters of the network are obtained using the valid-subspace technique. Simulated examples are presented as an illustration of the proposed approach. Copyright (C) 2000 IFAC.

The minimization of open stacks problem: A review of some properties and their use in pre-processing operations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of the microwave oven on structural, morphological and electrical properties of SrBi4Ti4O15 thin films grown on Pt/Ti/SiO2/Si substrates by a soft chemical method

Thin films of SrBi4Ti4O15 (SBTi), a prototype of the Bi-layered-ferroelectric oxide family, were obtained by a soft chemical method and crystallized in a domestic microwave oven. For comparison, films were also crystallized in a conventional method at 700 degrees C for 2 h. Structural and morphological characterization of the SBTi thin films were investigated by Xray diffraction (XRD) and atomic force microscopy (AFM), respectively. Using platinum coated silicon substrates, the ferroelectric properties of the films were determined. Remanent polarization P-r and a coercive field E-c values of 5.1 mu C/cm(2) and 135 kV/cm for the film thermally treated in the microwave oven and 5.4 mu C/cm(2) and 85 kv/cm for the film thermally treated in conventional furnace were found. The films thermally treated in the conventional furnace exhibited excellent fatigue-free characteristics up to 10(10) switching cycles indicating that SBTi thin films are a promising material for use in non-volatile memories. (C) 2007 Elsevier B.V. All rights reserved.

Morphological evolution of tin oxide nanobelts after phase transition

This article reports a study of the thermal stability and morphological changes in tin oxide nanobelts grown in the orthorhombic SnO phase. The nanobelts were heat-treated in a differential scanning calorimetry (DSC) furnace at 800 degrees C for I It in argon, oxygen, or synthetic air atmospheres. The samples were then characterized by DSC, X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and high resolution field emission scanning electron microscopy (FE-SEM). The results confirmed that the orthorhombic SnO phase is thermodynamically unstable, causing the belts to transform into the SnO2 phase when heat-treated. During the phase transition, if oxygen is available in the furnace atmosphere, nanofibers grow at the edge of nanobelts at about 50 degrees of the belts' growth direction, while particles grow on the belt surface in the absence of oxygen. Although the decomposition process reduces the nanobelt cell volume by 22%, most belts remain monocrystalline after the heat treatment. The results confirm that phase transition is a decomposition process, which explains the morphological changes in the belts based on metallic tin generated in the process.

Cellulose nanowhiskers from coconut husk fibers: Effect of preparation conditions on their thermal and morphological behavior

Cellulose nanowhiskers were prepared by sulfuric acid hydrolysis from coconut husk fibers which had previously been submitted to a delignification process. The effects of preparation conditions on the thermal and morphological behavior of the nanocrystals were investigated. Cellulose nanowhisker suspensions were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and X-ray diffraction. Results showed that it was possible to obtain ultrathin cellulose nanowhiskers with diameters as low as 5 nm and aspect ratio of up to 60. A possible correlation between preparation conditions and particle size was not observed. Higher residual lignin content was found to increase thermal stability indicating that by controlling reaction conditions one can tailor the thermal properties of the nanowhiskers. Published by Elsevier Ltd.

Electromyographical, ultrasonographical and morphological modifications in semitendinous muscle after transposition as ventral perineal muscle flap

The aim of this study was to evaluate modifications occurring in semitendinous muscle after transposition as a ventral perineal muscle flap using electromyography, ultrasonography, and morphological studies. Ten male crossbreed dogs of 3-4 year old were used. The left semitendinous muscle was cut close to the popliteus lymph node, rotated and sutured at the perineal region. The contralateral muscle was considered as control. Motor nerve conduction studies of both sciatic-tibial nerves, and electromyographic and ultrasonographic examinations of both semitendinous muscles were performed before surgery and 15, 30, 60, and 90 days postoperatively. Semitendinous muscle samples were collected for morphological analysis 90 days after surgery. No alterations were observed in clinical gait examinations, or in goniometrical and electroneuromyographical studies in pelvic limbs after surgery. Electromyography demonstrated that the transposed muscle was able to contract, but atrophy was detected by ultrasonography and morphological analysis.

Morphological and functional evaluation of distal esophagus of rabbits submitted to esophageal infusion with caustic soda

A ingestão de substâncias cáusticas constitui importante situação de emergência, tendo em vista a gravidade de suas seqüelas. OBJETIVO: Estudar as alterações morfológicas e funcionais do esôfago de coelhos submetidos à infusão esofágica com soda cáustica (NaOH). MÉTODOS: 88 coelhos foram divididos em 4 grupos: G1 (n=22) foi submetido à infusão esofágica com água destilada; G2, G3 e G4 foram submetidos a infusão esofágica com NaOH a 2%, 4% e 6%, respectivamente. Alterações morfológicas foram estudadas em 12 animais de cada grupo e as alterações manométricas, nos 10 animais restantes. Foram feitas análises do esfíncter inferior do esôfago (EIE), número e amplitude das contrações no terço distal do esôfago. Estes estudos foram realizados antes (momento 1 - M1) e aos 30 minutos, 6 horas e 24 horas após a infusão esofágica (momentos M2, M3 e M4, respectivamente). RESULTADOS: Avaliação macroscópica: G1 - sem alterações; G2 - edema, hiperemia e descamação; G3 - aumento do calibre do esôfago, úlceras, descamação da mucosa; G4 - lesões semelhantes as do G3, porém mais intensas, áreas de extensa hemorragia. Avaliação funcional: a pressão no EIE foi mais elevada em M2 no grupo 2; o número das contrações no terço distal do esôfago foi menor em G3 e G4, e a amplitude das contrações foi menor em G4. CONCLUSÕES: 1) a infusão esofágica com NaOH constitui excelente modelo experimental de esofagite cáustica no coelho; 2) a infusão esofágica com NaOH causa lesões na parede do esôfago, com gravidade proporcional a concentração da solução; 3) a infusão causou espasmo do EIE em M2 e redução do número e amplitude das contrações no terço distal do esôfago.

Correlation between the intensity of venous reflux in the saphenofemoral junction and morphological changes of the great saphenous vein by duplex scanning in patients with primary varicosis

Aim. One of the major causes of chronic venous disease is venous reflux, the identification and quantification of which are important for diagnosis. Duplex scanning allows for the detection and quantification of reflux in individual veins. Evaluation of the great saphenous vein in primary varicosis is necessary for its preservation. Objective of the study is to evaluate a possible correlation between the intensity of reflux at the saphenofemoral junction, diameter alterations of the incompetent great saphenous vein and the practical effect of such correlation. Also to compare the clinical severity of the CEAP classification with such parameters.Methods. Three hundred limbs were submitted to duplex evaluation of their insufficient saphenous veins. Vein diameter was measured on five different points. Velocity and flow at reflux peak and reflux time were determined. The saphenous vein's diameters were correlated with velocity, flow and time. The three latter parameters and diameters were compared with clinical severity according to CEAP.Results. Correlation was found between the saphenous vein's diameters, velocity and flow. No correlation was observed between time and diameter in the thigh's upper and middle thirds. When comparing diameter, velocity and flow with CEAP clinical severity classification, an association was observed. The correlation between reflux time with clinical severity was weak.Conclusion. Reflux time is a good parameter for identifying the presence of reflux, but not for quantifying it. Velocity and peak flow were better parameters for evaluating reflux intensity as they were correlated with great saphenous vein alterations, and were associated with the disease's clinical severity. [Int Angiol 2010;29:323-30]

Mechanical, biochemical, and morphological changes in the heart from chronic food-restricted rats

Food restriction (FR) has been shown to induce important morphological changes in rat myocardium. However, its influence on myocardial performance is not completely defined. We examined the effects of chronic FR on cardiac muscle function and morphology. Sixty-day-old Wistar-Kyoto rats were fed a control (C) or a restricted diet (daily intake reduced to 50% of the amount of food consumed by the control group) for 90 days. Myocardial performance was studied in isolated left ventricular (LV) papillary muscle. Fragments of the LV free wall were analysed by light microscopy, and the ultrastructure of the myocardium was examined in the LV papillary muscle. The myocardial collagen concentration was also evaluated. FR decreased body weight (BW) and LV weight (LVW); the LVW/BW ratio was higher in the restricted group (C, 1.86 +/- 0.17 mg/g; FR, 2.19 +/- 0.31 mg/g; p < 0.01). In the FR animals, the cardiac fibers were polymorphic, some of them were of small diameter and others presented lateral infoldings; the ultrastructural alterations were focal and included reduction of sarcoplasmic content, absence and (or) disorganization of myofilaments and Z line, numerous electron dense and polymorphic mitochondria, and deep infoldings of the plasma membrane. The hydroxyproline concentration was higher in the FR animals (p < 0.01). FR prolonged the contraction and relaxation time of the papillary muscle and did not change its ability to contract and shorten. In conclusion, although a 90-day period of FR caused striking myocardial ultrastructural alterations and increased the collagen concentration, it only minimally affected the mechanical function.

Morphological and molecular characterization of an equine isolate of Pythium insidiosum and comparison with the first human isolate from the same geographic region

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

Dysphonia and laryngeal sequelae in paracoccidioidomycosis patients: a morphological and phoniatric study

The larynx is the third most commonly involved organ in paracoccidioidomycosis (PCM). While a few studies have evaluated laryngeal sequelae, there have not been any investigations of voice abnormalities in PCM patients. To evaluate persistent dysphonia and laryngeal lesions, we studied 15 normal subjects and 30 post-treatment PCM patients, i.e., 15 with only pulmonary and 15 with both laryngeal and pulmonary involvement. Perceptual and acoustic voice analysis were performed with all patients, while endoscopic studies were also conducted with the 15 laryngeal patients. Voice analysis showed instability by perceptual analysis (P < 0.01) in both groups, but more severe dysphonia was noted in the laryngeal group (P < 0.01). The dysponia, seen in 66.7% of these patients (dysphonia index < 7.0), was characterized by roughness and breathness. The Dr. Speech (Tiger Electronics) analysis program did not accept five voices from the laryngeal group due to the severe dysphonia. Jitter was elevated in five laryngeal lesion patients. Endoscopy showed that 80% of patients with laryngeal lesion had two or more laryngeal structures involved. Vocal fold alterations were seen in all laryngeal lesion patients, which included involvement of the arythenoids, epiglottis, and vestibular folds. This first functional study of laryngeal sequelae in PCM revealed frequent and severe dysphonia that may have important social consequences for patients.