1,106 research outputs found
Recommended from our members
Intellectual Property Rights as Protected Investments: How Open are the Gates?
This is the author accepted manuscript. It is currently embargoed pending publication
Imaging study of thoracic outlet syndrome
Universidade Federal de São Paulo (UNIFESP)UNIFESP Departamento de Diagnóstico por ImagemUniversidade Federal do Rio de JaneiroHospital de Caridade São BrásUNIFESP, Depto. de Diagnóstico por ImagemSciEL
Quantitative evaluation of lateral forces on the patella: static and kinematic magnetic resonance imaging
OBJECTIVE: To evaluate the usefulness of combining static and kinematic magnetic resonance imaging in the evaluation of the femoropatellar joint. MATERIALS AND METHODS: Twenty healthy volunteers (40 knees) and 23 patients (43 knees) were submitted to both static and kinematic magnetic resonance imaging on a 1.5 tesla whole-body magnetic resonance scanner. The knees were positioned at 30º flexion with the quadrature knee coil at the inner end of the examination table. The patellar translation was evaluated by measurements of bisect offset, lateral patellar displacement and patellar tilt angle. The nonparametric Wilcoxon test was utilized for statistical analysis of data resulting from the static and kinematic studies in both groups. Nonparametric Mann-Whitney test was utilized in the comparison between healthy volunteers and patients. RESULTS: Statistical analysis demonstrated significant differences (p < 0.05) between static and kinematic magnetic resonance imaging for the three parameters evaluated in both groups. Among the patients the differences between static and kinematic measurements were greater than those found in the volunteers, at 30° and 20° flexion, with bisect offset and lateral patellar displacement. CONCLUSION: Static and kinematic magnetic resonance imaging, when performed in association, demonstrated that the lateral forces being exerted on the patella are higher at a knee flexion at the range between 20° and 30°, particularly in individuals symptomatic for femoropatellar instability.OBJETIVO: Avaliar a validade da ressonância magnética cinemática combinada com a ressonância magnética estática no estudo da articulação femoropatelar. MATERIAIS E MÉTODOS: Foram realizadas ressonância magnética estática e ressonância magnética cinemática em 20 voluntários assintomáticos (40 joelhos) e em 23 pacientes (43 joelhos), em aparelho de configuração fechada de 1,5 tesla de campo. Os indivíduos foram posicionados na extremidade da mesa, em 30° de flexão. A translação patelar foi avaliada medindo-se o desvio da bissetriz, o deslocamento lateral da patela e o ângulo de inclinação da patela. Para a comparação entre os estudos estático e cinemático, foi utilizado o teste não-paramétrico de Wilcoxon. Para a comparação entre os voluntários e os pacientes, foi utilizado o teste de Mann-Whitney. RESULTADOS: Houve diferenças significantes entre a ressonância magnética estática e a ressonância magnética cinemática (p < 0,05) nos três parâmetros utilizados. No grupo dos pacientes, as diferenças entre a ressonância magnética estática e a ressonância magnética cinemática foram maiores que nos voluntários a 20° e a 30° de flexão, com o desvio da bissetriz e com o deslocamento lateral da patela. CONCLUSÃO: A combinação da ressonância magnética estática e ressonância magnética cinemática evidenciou que a força resultante lateral é maior na faixa de 20° e 30° de flexão, especialmente nos indivíduos sintomáticos, para a instabilidade femoropatelar.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Diagnóstico por ImagemSociedade Brasileira de Ortopedia e TraumatologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Ortopedia e TraumatologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Medicina Preventiva e BioestatísticaUNIFESP, EPM, Depto. de Diagnóstico por ImagemUNIFESP, EPM, Depto. de Ortopedia e TraumatologiaUNIFESP, EPM, Depto. de Medicina Preventiva e BioestatísticaSciEL
Quantum Holographic Encoding in a Two-dimensional Electron Gas
The advent of bottom-up atomic manipulation heralded a new horizon for
attainable information density, as it allowed a bit of information to be
represented by a single atom. The discrete spacing between atoms in condensed
matter has thus set a rigid limit on the maximum possible information density.
While modern technologies are still far from this scale, all theoretical
downscaling of devices terminates at this spatial limit. Here, however, we
break this barrier with electronic quantum encoding scaled to subatomic
densities. We use atomic manipulation to first construct open
nanostructures--"molecular holograms"--which in turn concentrate information
into a medium free of lattice constraints: the quantum states of a
two-dimensional degenerate Fermi gas of electrons. The information embedded in
the holograms is transcoded at even smaller length scales into an atomically
uniform area of a copper surface, where it is densely projected into both two
spatial degrees of freedom and a third holographic dimension mapped to energy.
In analogy to optical volume holography, this requires precise amplitude and
phase engineering of electron wavefunctions to assemble pages of information
volumetrically. This data is read out by mapping the energy-resolved electron
density of states with a scanning tunnelling microscope. As the projection and
readout are both extremely near-field, and because we use native quantum states
rather than an external beam, we are not limited by lensing or collimation and
can create electronically projected objects with features as small as ~0.3 nm.
These techniques reach unprecedented densities exceeding 20 bits/nm2 and place
tens of bits into a single fermionic state.Comment: Published online 25 January 2009 in Nature Nanotechnology; 12 page
manuscript (including 4 figures) + 2 page supplement (including 1 figure);
supplementary movie available at http://mota.stanford.ed
Body composition, nutritional profile and muscular fitness affect bone health in a sample of schoolchildren from Colombia: The Fuprecol Study
This is the final version of the article. Available from the publisher via the DOI in this record.The objective of the present study is to investigate the relationships between body
composition, nutritional profile, muscular fitness (MF) and bone health in a sample of children
and adolescents from Colombia. Participants included 1118 children and adolescents (54.6% girls).
Calcaneal broadband ultrasound attenuation (c-BUA) was obtained as a marker of bone health.
Body composition (fat mass and lean mass) was assessed using bioelectrical impedance analysis.
Furthermore height, weight, waist circumference and Tanner stage were measured and body mass
index (BMI) was calculated. Standing long-jump (SLJ) and isometric handgrip dynamometry were
used respectively as indicators of lower and upper body muscular fitness. A muscular index score
was also computed by summing up the standardised values of both SLJ and handgrip strength.
Dietary intake and degree of adherence to the Mediterranean diet were assessed by a 7-day recall
questionnaire for food frequency and the Kidmed questionnaire. Poor bone health was considered
using a z-score cut off of ≤−1.5 standard deviation. Once the results were adjusted for age and
Tanner stage, the predisposing factors of having a c-BUA z-score ≤−1.5 standard deviation included
being underweight or obese, having an unhealthy lean mass, having an unhealthy fat mass, SLJ
performance, handgrip performance, and unhealthy muscular index score. In conclusion, body
composition (fat mass and lean body mass) and MF both influenced bone health in a sample of
children and adolescents from Colombia. Thus promoting strength adaptation and preservation in
Colombian youth will help to improve bone health, an important protective factor against osteoporosis
in later life.: We would like to acknowledge to Bogota District Education Department for supporting data
collection for this study. The authors also thank the participating Bogota District students, teachers, schools, and
staff. The “FUPRECOL Study” was possible given the financial support provided by the Instituto Colombiano
para el Desarrollo de la Ciencia y la Tecnología “Francisco José de Caldas” COLCIENCIAS (Contract Number
671-2014 Code 122265743978). Also, during the completion of this paper, AG-H was visiting researchers at
the University of Rosario (CEMA, Bogotá, Colombia), supported with grants awarded by Proyectos Basales y
Vicerrectoría de Investigación, Desarrollo e Innovación” (Universidad de Santiago de Chile, USACH)
Domain wall brane in squared curvature gravity
We suggest a thick braneworld model in the squared curvature gravity theory.
Despite the appearance of higher order derivatives, the localization of gravity
and various bulk matter fields is shown to be possible. The existence of the
normalizable gravitational zero mode indicates that our four-dimensional
gravity is reproduced. In order to localize the chiral fermions on the brane,
two types of coupling between the fermions and the brane forming scalar is
introduced. The first coupling leads us to a Schr\"odinger equation with a
volcano potential, and the other a P\"oschl-Teller potential. In both cases,
the zero mode exists only for the left-hand fermions. Several massive KK states
of the fermions can be trapped on the brane, either as resonant states or as
bound states.Comment: 18 pages, 5 figures and 1 table, references added, improved version
to be published in JHE
Correlation Between Mucosal IL-6 mRNA Expression Level and Virulence Factors of Helicobacter pylori in Iranian Adult Patients With Chronic Gastritis
Background: Helicobacter pylori infection is associated with gastritis and marked infiltration of the gastric mucosa by several cytokines secreting inflammatory cells that contribute to sustained local inflammation. In this study, we sought to examine IL-6 expression in H. pylori-infected and uninfected gastric mucosa and elucidate the implication in the pathogenesis of H. pylori-associated gastritis in human. Objectives: The current study aimed to determine mucosal IL-6 mRNA expression level and their correlation with virulence factors and the grade of chronic gastritis among H. pylori infected patients with chronic gastritis from Shahrekord, Iran. Patients and Methods: Mucosal IL-6 mRNA levels was measured by real-time PCR using endoscopic biopsies taken from the gastric antrum of 58 subjects infected with H. pylori and 44 uninfected subjects. Presence of vacA and cagA virulence factors was evaluated using PCR. Results: The IL-6 mRNA expression levels were significantly more elevated in H. pylori-positive patients than uninfected individuals and expression of this cytokine was independent from the virulence factors. There was a correlation between IL-6 expression level and the grade of chronic gastritis. Conclusions: Enhanced induction of IL-6 may be involved in the pathogenesis of H. pylon-associated gastritis
- …