Photorefractive two-wave mixing phase coupling measurement in a self-stabilized recording regime

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Universal zero-bias conductance through a quantum wire side-coupled to a quantum dot

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fast sequential multi-element determination of Ca, Mg, K, Cu, Fe, Mn and Zn for foliar diagnosis using high-resolution continuum source flame atomic absorption spectrometry: Feasibility of secondary lines, side pixel registration and least-squares background correction

The fast sequential multi-element determination of Ca, Mg, K, Cu, Fe, Mn and Zn in plant tissues by high-resolution continuum source flame atomic absorption spectrometry is proposed. For this, the main lines for Cu (324.754 nm), Fe (248.327 nm), Mn (279.482 nm) and Zn (213.857 nm) were selected, and the secondary lines for Ca (239.856 nm), Mg (202.582 nm) and K (404.414 nm) were evaluated. The side pixel registration approach was studied to reduce sensitivity and extend the linear working range for Mg by measuring at wings (202.576 nm; 202.577 nm; 202.578 nm; 202.580 nm: 202.585 nm; 202.586 nm: 202.587 nm; 202.588 nm) of the secondary line. The interference caused by NO bands on Zn at 213.857 nm was removed using the least-squares background correction. Using the main lines for Cu, Fe, Mn and Zn, secondary lines for Ca and K, and line wing at 202.588 nm for Mg, and 5 mL min(-1) sample flow-rate, calibration curves in the 0.1-0.5 mg L-1 Cu, 0.5-4.0 mg L-1 Fe, 0.5-4.0 mg L-1 Mn, 0.2-1.0 mg L-1 Zn, 10.0-100.0 mg L-1 Ca, 5.0-40.0 mg L-1 Mg and 50.0-250.0 mg L-1 K ranges were consistently obtained. Accuracy and precision were evaluated after analysis of five plant standard reference materials. Results were in agreement at a 95% confidence level (paired t-test) with certified values. The proposed method was applied to digests of sugar-cane leaves and results were close to those obtained by line-source flame atomic absorption spectrometry. Recoveries of Ca, Mg, K, Cu, Fe, Mn and Zn in the 89-103%, 84-107%, 87-103%, 85-105%, 92-106%, 91-114%, 96-114% intervals, respectively, were obtained. The limits of detection were 0.6 mg L-1 Ca, 0.4 mg L-1 Mg, 0.4 mg L-1 K, 7.7 mu g L-1 Cu, 7.7 mu g L-1 Fe, 1.5 mu g L-1 Mn and 5.9 mu g L-1 Zn. (C) 2009 Elsevier B.V. All rights reserved.

Plasmonic Coupling in Er3+:Au Tellurite Glass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of electrical stimulation of the cranial tibial muscle after end-to-side neurorrhaphy of the peroneal nerve in rats

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

An exactly soluble multiatom-multiphoton coupling model

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

Phenomenology of infrared finite gluon propagator and coupling constant

We report on some recent solutions of the Dyson-Schwinger equations for the infrared behavior of the gluon propagator and coupling constant, discussing their differences and proposing that these different behaviors can be tested through hadronic phenomenology. We discuss which kind of phenomenological tests can be applied to the gluon propagator and coupling constant, how sensitive they are to the infrared region of momenta and what specific solution is preferred by the experimental data.

End-to-side neurorrhaphy with and without perineurium

OBJETIVOS: Comparar a neurorrafia término-lateral com epineuro versus sem epineuro. DESENHO: Foram operados 20 ratos. O nervo fibular foi seccionado e seu coto distal suturado na face lateral do nervo tibial. do lado direito nós removemos janela de epineuro e no lado esquerdo o epineuro foi deixado intacto. Depois de seis meses, os 14 animais sobreviventes foram submetidos a testes eletrofisiológicos, sacrificados e os nervos e músculos removidos para exames histológicos. O teste eletrofisiológico foi realizado mediante estímulo elétrico fornecido por um neuro-estimulador (LHM-110) com 2 milisegundos de duração, num modo repetido e 30 Hz. O estímulo foi aumentado progressivamente partindo de zero até atingir 1 volt. LOCAL: Faculdade de Medicina de Botucatu. RESULTADOS: No lado direito, os músculos que tiveram resposta positiva necessitaram uma média de 258,89 mv (±92,31) de estímulo elétrico para apresentar uma resposta e no lado esquerdo uma média de 298,34 mV (±139,32). O músculo tibial cranial apresentou peso médio para o lado direito de 0,47 g (±0,18) e para o lado esquerdo de 0,45 g (±0,15). O coto distal do nervo fibular apresentou uma média 310 fibras nervosas (±191,34) para o lado direito e 287,71 (±183,60) para o lado esquerdo. O nervo tibial acima da neurorrafia mostrou médias de 939,46 (±223,51) fibras nervosas para o lado direito e 959,46 (±327,48) para o lado esquerdo. O nervo tibial abaixo da neurorrafia mostrou médias de 935,17 (±298,65) fibras nervosas para o lado direito e 755,31 (±323,26) para o lado esquerdo. As fibras do músculo tibial cranial do lado direito apresentaram uma área média de 0,0162 (±0,008) m2 depois de 230 vezes de magnificação e 0,0152 (±0,0064) para as fibras do músculo tibial cranial do lado esquerdo. O aspecto histológico do músculo tibial cranial, tomando-se o normal como 100% foi de 78,21 (±20,75) para o lado direito e 82,14 (±15,89) para o lado esquerdo. A análise estatística (testetde Student) não mostrou diferenças (p>0,05) entre os lados esquerdo e direito para todas as variáveis. CONCLUSÕES: Ambas as neurorrafias (com e sem epineuro) não mostraram diferenças relacionadas aos aspectos morfológicos e eletrofisiológicos estudados.

2 END-TO-SIDE NEURORRHAPHIES AND NERVE GRAFT WITH REMOVAL OF THE EPINEURAL SHEATH - EXPERIMENTAL-STUDY IN RATS

We have studied a new type of end-to-side nerve repair in rats. The healthy (donor) nerve was not divided but an epineural window was created. In our experiment, a nerve graft bridged the tibial nerve to the distal end of the divided peroneal nerve. Electrophysiological studies showed electrical impulses conducted through both end-to-side nerve junctions. Histological studies demonstrated axons leaving the lateral surface of the healthy (donor) nerve. Based on these observations, we suggest that end-to-side neurorrhaphy from a healthy nerve may bridge a neural deficit.

Physical activity and postural control in the elderly: Coupling between visual information and body sway

Background: Aging is characterized by a decline in the postural control performance, which is based on a coherent and stable coupling between sensory information and motor action. Therefore, changes in postural control in elderlies can be related to changes in this coupling. In addition, it has been observed that physical activity seems to improve postural control performance in elderlies. These improvements can be due to changes in the coupling between sensory information and motor action related to postural control. Objective: the purpose of this study was to verify the coupling between visual information and body sway in active and sedentary elderlies. Methods: Sixteen sedentary elderlies ( SE), 16 active elderlies ( AE) and 16 young adults ( YA) were asked to stand upright inside a moving room in two experimental conditions: ( 1) discrete movement and ( 2) continuous movement of the room. Results: In the continuous condition, the results showed that the coupling between the movement of the room and body sway was stronger and more stable for SE and AE compared to YA. In the discrete condition, SE showed larger body displacement compared to AE and YA. Conclusions: SE have more difficulty to discriminate and to integrate sensory information than AE and YA indicating that physical activity may improve sensory integration. Copyright (C) 2005 S. Karger AG, Basel.

Manipulation of anchoring strength in an azo-dye side chain polymer by photoisomerization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On the coupling of the self-dual field to dynamical U(1) matter and its dual theory

We consider arbitrary U (1) charged matter non-minimally coupled to the self-dual field in d = 2 + 1. The coupling includes a linear and a rather general quadratic term in the self-dual field. By using both Lagragian gauge embedding and master action approaches we derive the dual Maxwell Chern-Simons-type model and show the classical equivalence between the two theories. At the quantum level the master action approach in general requires the addition of an awkward extra term to the Maxwell Chern-Simons-type theory. Only in the case of a linear coupling in the self-dual field can the extra term be dropped and we are able to establish the quantum equivalence of gauge invariant correlation functions in both theories.