10,816 research outputs found
Alignment in total knee arthroplasty : what’s in a name?
Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved
Caracterização molecular de populações de Fusarium oxysporum f. sp. cubense em regiões produtoras de banana na Bahia.
O mal-do-Panamá, causado pelo fungo Fusarium oxysporum f. sp. cubense (Foc), é uma das doenças mais destrutivas da bananeira, sendo considerada entre as cinco doenças economicamente mais importantes de todos os tempos. O fato de ser causada por um fungo do solo que, mesmo na ausência da cultura, sobrevive por períodos prolongados, faz com que a medida de controle mais efetiva seja o uso de variedades resistentes. Desta forma, o projeto tem como objetivo caracterizar populações brasileiras de Foc por meio de marcadores SSR
Coleção Biológica de trabalho de Fusarium oxysporum f. sp. Cubense: do Laboratório de Fitopatologia.
A cultura da bananeira (Musa spp.) é a base econômica de muitas nações. E a banana, por sua vez, é a fruta mais consumida no mundo, sendo para alguns, item de segurança alimentar. A bananicultura está entre as atividades agrícolas de maior expressão econômica e social no Brasil.bitstream/item/56745/1/folder-colecao-biologica-de-trabalho-de-fusarium-oxysporum-INTERNET-2.pd
Preparation, Characterization And Tests Of Incorporation In Stem Cells Of Superparamagnetic Iron Oxide
Superparamagnetic iron oxide nanoparticles (SPIONs) have been produced and used as contrast-enhancing agents in magnetic resonance imaging (MRI) for diagnostic use in a wide range of maladies including cardiovascular, neurological disorders, and cancer. The reasons why these SPIONs are attractive for medical purposes are based on their important and unique features. The large surface area of the nanoparticles and their manipulation through an external magnetic field are features that allow their use for carrying a large number of molecules such as biomolecules or drugs. In this scenario, the present work reports on the synthesis and characterization of SPIONs and in vitro MRI experiments to increase their capacity as probes for MRI applications on stem cells therapy. Initially, the SPIONs were prepared through the co-precipitation method using ferrous and ferric chlorides in acidic solution. The SPIONs were coated with two thiol molecules such as mercaptosuccinic acid (MSA) and cysteine (Cys) (molar ratio SPIONs: ligand = 1: 20), leading to the formation of a stable aqueous dispersion of thiolated nanoparticles (SH-SPIONs). The SH-SPIONs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that the SH-SPIONs have a mean diameter of 14 nm and display superparamagnetic behavior at room temperature. Preliminary tests of incorporation of SH-SPIONs were evaluated stem cells. The results showed that the thiolated nanoparticles have no toxic effects for stem cells and successfully internalized and enhance the contrast in MRI.61
Relativistic linear stability equations for the nonlinear Dirac equation in Bose-Einstein condensates
We present relativistic linear stability equations (RLSE) for
quasi-relativistic cold atoms in a honeycomb optical lattice. These equations
are derived from first principles and provide a method for computing
stabilities of arbitrary localized solutions of the nonlinear Dirac equation
(NLDE), a relativistic generalization of the nonlinear Schr\"odinger equation.
We present a variety of such localized solutions: skyrmions, solitons,
vortices, and half-quantum vortices, and study their stabilities via the RLSE.
When applied to a uniform background, our calculations reveal an experimentally
observable effect in the form of Cherenkov radiation. Remarkably, the Berry
phase from the bipartite structure of the honeycomb lattice induces a
boson-fermion transmutation in the quasi-particle operator statistics.Comment: 6 pages, 3 figure
The two-component Beta-t-QVAR-M-lev: a new forecasting model
We introduce a new joint model of expected return and volatility forecasting, namely the two-component Beta-t-QVAR-M-lev (quasi-vector autoregression in-mean with leverage). The maximum likelihood estimator for the two-component Beta-t-QVAR-M-lev is an extension of theoretical results of the one-component Beta-t-QVAR-M. We compare the volatility forecasting performance of the two-component Beta-t-QVAR-M-lev and two-component GARCH-M (generalized autoregressive conditional heteroscedasticity), also considering their one-component frameworks. The results for G20 stock market indices indicate that the forecasting performance of the two-component Beta-t-QVAR-M-lev is superior compared with the two-component GARCH-M and their one-component versions
Training deep neural density estimators to identify mechanistic models of neural dynamics
Mechanistic modeling in neuroscience aims to explain observed phenomena in terms of underlying causes. However, determining which model parameters agree with complex and stochastic neural data presents a significant challenge. We address this challenge with a machine learning tool which uses deep neural density estimators-- trained using model simulations-- to carry out Bayesian inference and retrieve the full space of parameters compatible with raw data or selected data features. Our method is scalable in parameters and data features, and can rapidly analyze new data after initial training. We demonstrate the power and flexibility of our approach on receptive fields, ion channels, and Hodgkin-Huxley models. We also characterize the space of circuit configurations giving rise to rhythmic activity in the crustacean stomatogastric ganglion, and use these results to derive hypotheses for underlying compensation mechanisms. Our approach will help close the gap between data-driven and theory-driven models of neural dynamics
Preparation, characterization and tests of incorporation in stem cells of superparamagnetic iron oxide
Superparamagnetic iron oxide nanoparticles (SPIONs) have been produced and used as contrast-enhancing agents in magnetic resonance imaging (MRI) for diagnostic use in a wide range of maladies including cardiovascular, neurological disorders, and cancer. The reasons why these SPIONs are attractive for medical purposes are based on their important and unique features. The large surface area of the nanoparticles and their manipulation through an external magnetic field are features that allow their use for carrying a large number of molecules such as biomolecules or drugs. In this scenario, the present work reports on the synthesis and characterization of SPIONs and in vitro MRI experiments to increase their capacity as probes for MRI applications on stem cells therapy. Initially, the SPIONs were prepared through the co-precipitation method using ferrous and ferric chlorides in acidic solution. The SPIONs were coated with two thiol molecules such as mercaptosuccinic acid (MSA) and cysteine (Cys) (molar ratio SPIONs: ligand = 1: 20), leading to the formation of a stable aqueous dispersion of thiolated nanoparticles (SH-SPIONs). The SH-SPIONs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that the SH-SPIONs have a mean diameter of 14 nm and display superparamagnetic behavior at room temperature. Preliminary tests of incorporation of SH-SPIONs were evaluated stem cells. The results showed that the thiolated nanoparticles have no toxic effects for stem cells and successfully internalized and enhance the contrast in MRI6174th International Conference on Safe Production and Use of Nanomaterials (Nanosafe
On the number of contacts of a floating polymer chain cross-linked with a surface adsorbed chain on fractal structures
We study the interaction problem of a linear polymer chain, floating in
fractal containers that belong to the three-dimensional Sierpinski gasket (3D
SG) family of fractals, with a surface-adsorbed linear polymer chain. Each
member of the 3D SG fractal family has a fractal impenetrable 2D adsorbing
surface, which appears to be 2D SG fractal. The two-polymer system is modelled
by two mutually crossing self-avoiding walks. By applying the Monte Carlo
Renormalization Group (MCRG) method, we calculate the critical exponents
, associated with the number of contacts of the 3D SG floating polymer
chain, and the 2D SG adsorbed polymer chain, for a sequence of SG fractals with
. Besides, we propose the codimension additivity (CA) argument
formula for , and compare its predictions with our reliable set of the
MCRG data. We find that monotonically decreases with increasing ,
that is, with increase of the container fractal dimension. Finally, we discuss
the relations between different contact exponents, and analyze their possible
behaviour in the fractal-to-Euclidean crossover region .Comment: 15 pages, 3 figure
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