Pion structure function within the instanton model

The leading-twist valence-quark distribution function in the pion is obtained at a low normalization scale of an order of the inverse average size of an instanton pc. The momentum dependent quark mass and the quark-pion vertex are constructed in the framework of the instanton liquid model, using a gauge invariant approach. The parameters of instanton vacuum, the effective instanton radius and quark mass, are related to the vacuum expectation values of the lowest dimension quark-gluon operators and to the pion low energy observables. An analytic expression for the quark distribution function in the pion for a general vertex function is derived. The results are QCD evolved to higher momentum-transfer values, and reasonable agreement with phenomenological analyses of the data on parton distributions for the pion is found. ©2000 The American Physical Society.

Moderate physical training increases brain insulin concentrations in experimental diabetic rats

Insulin is an important modulator of growth and metabolic function in the central nervous system. The aim of this study was to investigate the influence of swimming physical training (at 32̈±1̈C, 1 hr/day, 5 days/week, with an overload equivalent to 5% of the body weight, for 4 weeks) on brain insulin concentrations in alloxan induced type 1 diabetic rats. Training attenuated hyperglycemia but had no effect on insulinemia in diabetic rats. Hematocrit and blood albumin values remained without changes. Brain insulin did not change in diabetic rats. However, physical training increased the concentration in both control and diabetic rats. It is concluded that in the present experimental conditions, diabetes had no influence on brain insulin, however moderate physical training increased the hormone in both control and diabetic animals.

Construction and test of low cost X-ray tomography scanner for physical-chemical analysis and nondestructive inspections

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe the development of a low cost micro-CT X-ray scanner that is being developed for nondestructive testing. This tomograph operates using a microfocus X-ray source and contains a silicon photodiode as detectors. The performance of the system, by its spatial resolution, has been estimated through its Modulation Transfer Function - MTF and the obtained value at 10% of MTF is 661 μm. It was built as a general purpose nondestructive testing device. © 2009 American Institute of Physics.

A human retrieval study of plasma-sprayed hydroxyapatite-coated plateau root form implants after 2 months to 13 years in function

Calcium phosphate-based bioactive ceramics in various physical and chemical formulations have been extensively utilized as biomaterials for bone regeneration/conduction. However, the determination of their in vivo temporal behavior from the short to long term in humans has been a challenge due to the lack of physical reference for morphologic and morphometric evaluation. The present study evaluated bone morphology and morphometry (bone-to-implant contact [BIC]) around plasma-sprayed hydroxyapatite (PSHA)-coated endosseous implants that were retrieved due to prosthetic reasons while successfully in function at the posterior region of the jaws from as early as 2 months to ~13 years after a 6-month healing period after placement. Bone morphology was evaluated by light microscopy, and BIC was determined using computer software. Irrespective of the time in vivo, lamellar bone was observed in close contact with the implant PSHA-coated surface and between plateaus. BIC ranged from ~35-95%, was highly directional, and Haversian-like osteonic morphology between plateaus was observed for most implants. The PSHA coating was present with little variation in thickness between the samples retrieved regardless of time in vivo. © 2010 by Begell House, Inc.

A PZT-based technique for SHM using the coherence function

This paper presents a new approach for damage detection in structural health monitoring systems exploiting the coherence function between the signals from PZT (Lead Zirconate Titanate) transducers bonded to a host structure. The physical configuration of this new approach is similar to the configuration used in Lamb wave based methods, but the analysis and operation are different. A PZT excited by a signal with a wide frequency range acts as an actuator and others PZTs are used as sensors to receive the signal. The coherences between the signals from the PZT sensors are obtained and the standard deviation for each coherence function is computed. It is demonstrated through experimental results that the standard deviation of the coherence between the signals from the PZTs in healthy and damaged conditions is a very sensitive metric index to detect damage. Tests were carried out on an aluminum plate and the results show that the proposed methodology could be an excellent approach for structural health monitoring (SHM) applications.

Monitoring chronic physical stress using biomarkers, performance protocols and mathematical functions to identify physiological adaptations in rats

This study was undertaken to characterize the effects of monotonous training at lactate minimum (LM) intensity on aerobic and anaerobic performances; glycogen concentrationsin the soleus muscle, the gastrocnemius muscle and the liver; and creatine kinase (CK), free fatty acids and glucose concentrations in rats. The rats were separated into trained (n =10), baseline (n = 10) and sedentary (n=10) groups. The trained group was submitted to the following: 60 min/day, 6 day/week and intensity equivalent to LM during the 12-week training period. The training volume was reduced after four weeks according to a sigmoid function. The total CK (U/L) increased in the trained group after 12 weeks (742.0±158.5) in comparison with the baseline (319.6±40.2) and the sedentary (261.6+42.2) groups. Free fatty acids and glycogen stores (liver, soleus muscle and gastrocnemius muscle) increased after 12 weeks of monotonous training but aerobic and anaerobic performances were unchanged in relation to the sedentary group. The monotonous training at LM increased the level of energy substrates, unchanged aerobic performance, reduced anaerobic capacity and increased the serum CK concentration; however, the rats did not achieve the predicted training volume.

Role of the range of the dipole function in the classical dynamics of molecular dissociation

The dissociation dynamics of heteronuclear diatomic molecules induced by infrared laser pulses is investigated within the framework of the classical driven Morse oscillator. The interaction between the molecule and the laser field described in the dipole formulation is given by the product of a time-dependent external field with a position-dependent permanent dipole function. The effects of changing the spatial range of the dipole function in the classical dissociation dynamics of large ensembles of trajectories are studied. Numerical calculations have been performed for distinct amplitudes and carrier frequencies of the external pulses and also for ensembles with different initial energies. It is found that there exist a set of values of the dipole range for which the dissociation probability can be completely suppressed. The dependence of the dissociation on the dipole range is explained through the examination of the Fourier series coefficients of the dipole function in the angle variable of the free system. In particular, the suppression of dissociation corresponds to dipole ranges for which the Fourier coefficients associated with nonlinear resonances are null and the chaotic region in the phase space is reduced to thin layers. In this context, it is shown that the suppression of dissociation of heteronuclear molecules for certain frequencies of the external field is a consequence of the finite range of the corresponding permanent dipole. © 2013 American Physical Society.

Effect of drying technique on some physical properties of cross-linked high amylose/pectin mixtures

Polymers mixtures as well as cross-linking reactions are approaches that have been used successfully to modulate the polymers characteristics in order to improve the control over drug release rate. High amylose and pectin are polysaccharides frequently used to prepare drug delivery systems. Since the drying technique can strongly influence the properties of such systems, the aim of this work was to characterize high amylose/pectin mixtures cross-linked with sodium trimetaphosphate and dried by different techniques-oven and lyophilization. The results showed that samples dried by lyophilization presented reduced particle size, higher porosity and higher swelling ability than the samples dried in oven. Besides, lower thermal stability and different diffraction patterns showed by the former particles should reflect the structural changes as a function of drying technique. © 2013 Informa Healthcare USA, Inc.

Cardiorespiratory fitness, but not central obesity or C-reactive protein, is related to liver function in obese children

Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent complications associated with excess adiposity. Its pathogenesis is complex and there are multiple factors that may contribute to it. AIM: To analyze whether cardiorespiratory ftness (CRF), waist circumference (WC), and C-reactive protein (CRP) are associated with alanine aminotransferase (ALT) in children with obesity. METHODS: 79 overweight/obese children of both genders, 11-13 year-olds, with abnormal serum ALT from Porto public schools comprised the sample. Measurements included CRF (20-m Shuttle Run Test), WC (NHANES protocol), CRP and ALT (Cholestech LDX analyzer). Logistic regression adjusted for gender, maturation, and weight with ALT levels as dependent variable (risk vs. non risk), and WC (risk vs. non risk), CRP (risk vs. non risk), and CRF (fit vs. unfit) as independent variables. Level of significance was set at 95%. RESULTS: Logistic regression showed that obese fit children were less likely to have abnormal ALT values (OR=.031) CONCLUSION: In obese children, higher cardiovascular fitness appears to reduce the chance of decreased liver function. © 2013 Human Kinetics, Inc.

Semi-synthetic minimal cells: Biochemical, physical, and technological aspects

The construction of synthetic cells is one of the major goals of bioengineering. The most successful approach consists in the encapsulation of biochemical materials (DNA, RNA, enzymes, etc.) inside lipid vesicles (liposomes), mimicking a cell structure. In this contribution, that also aims at introducing the reader to 'chemical synthetic biology,' we describe the current state of the art of 'semi-synthetic minimal cells' (SSMCs), namely, cell-like structures containing the minimal number of biological compounds that are required to reconstruct a function of interest. We will first describe how the concept of the minimal cell was originated and its relation with the theory of autopoiesis, then we review the most advanced results focused on genetic/metabolic networks inside liposomes. Next, we emphasize that relevance of physical aspects (too often neglected) that impact on the solute entrapment process, and finally we discuss new technological trends in SSMC research that will probably allow their future use in biotechnology. © 2013 Copyright © 2013 Elsevier Inc. All rights reserved.

Diastolic function is associated with quality of life and exercise capacity in stable heart failure patients with reduced ejection fraction

Exercise capacity and quality of life (QOL) are important outcome predictors in patients with systolic heart failure (HF), independent of left ventricular (LV) ejection fraction (LVEF). LV diastolic function has been shown to be a better predictor of aerobic exercise capacity in patients with systolic dysfunction and a New York Heart Association (NYHA) classification >II. We hypothesized that the currently used index of diastolic function E/e' is associated with exercise capacity and QOL, even in optimally treated HF patients with reduced LVEF. This prospective study included 44 consecutive patients aged 55±11 years (27 men and 17 women), with LVEF,0.50 and NYHA functional class I-III, receiving optimal pharmacological treatment and in a stable clinical condition, as shown by the absence of dyspnea exacerbation for at least 3 months. All patients had conventional transthoracic echocardiography and answered the Minnesota Living with HF Questionnaire, followed by the 6-min walk test (6MWT). In a multivariable model with 6MWT as the dependent variable, age and E/e' explained 27% of the walked distance in 6MWT (P=0.002; multivariate regression analysis). No association was found between walk distance and LVEF or mitral annulus systolic velocity. Only normalized left atrium volume, a sensitive index of diastolic function, was associated with decreased QOL. Despite the small number of patients included, this study offers evidence that diastolic function is associated with physical capacity and QOL and should be considered along with ejection fraction in patients with compensated systolic HF.

Nonsteroidal anti-inflammatory therapy: changes on renal function of healthy dogs

PURPOSE: To evaluate the renal function in healthy dogs submitted to nonselective and preferential COX-2 nonsteroidal anti-inflammatory drug (NSAID) therapy. METHODS: Twenty four healthy dogs were distributed into four groups (G) (n=6): ketoprofenG - treated with ketoprofen; nimesulideG - treated with nimesulid; meloxicanG - treated with meloxican; and etodolacG - treated with etodolaco. All the dogs received the NSAIDs for 10 days by oral route. Physical examination and renal function (urinalysis, urinary sodium and gamma-glutamyl transpeptidase (GGT), serum urea, creatinine, potassium and sodium, and endogenous creatinine clearance) were evaluated before, after five and ten days (T0, T5 and T10) of the treatment in all groups. RESULTS: Changes were observed in urinalysis, with a significant increase in renal cells in the urine at T5 and T10 in nimesulideG. Significant reduction in urinary sodium in nimesulideG at T5 was observed. The clearance values were lower in ketoprofenG at T10. CONCLUSIONS: Meloxicam and etodolac were the drugs that have proven to be safer for short-term therapy in healthy dogs in relation to renal function. NSAIDs ketoprofen and nimesulide should be used judiciously in dogs with renal dysfunction, since there are promoted changes in renal function.

Corn productivity in function of surface application of lime in differents management systems and cultural preparation

The evaluation of technologies employed at the agricultural production system such as crop rotation and soil preparation, both associated with crop-livestock integration, is crucial. Therefore, the aim of the present study was to evaluate the incorporation of lime for three no-tillage systems and cultural managements in system of crop-livestock integration, with emphasis on corn grain yield. The experiment was conducted from January 2003 to April 2005 at Selvíria city, MS, in Dystroferric Red Latosol, clay texture. The experimental design was randomized blocks with split plots consisted of three main treatments, aimed the soil physics conditioning and the incorporation of lime: PD - No-no-tillage; CM - minimum no-tillage, and PC - conventional no-tillage; and of two secondary treatments related to the management: rotation and crop succession, with four replications. Data on agronomic traits of maize were analyzed: plant height, stem diameter, height of the first spike insertion, 100 grains weight and grain yield. The results showed that the maize produced under the system of crop-livestock integration is quite feasible, showing that grain yields are comparable to averages in the region and the different soil physical conditioning and incorporation of lime did not influence the corn yield as well as the cultural managements, rotation and succession, did not affect the maize crop behavior after two years of cultivation.

Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Neonatally induced mild diabetes: influence on development, behavior and reproductive function of female Wistar rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)