3,425 research outputs found
Measurement of healing area using planimetry after applying low-intensity ultrasound to the skin of rats
CONTEXTUALIZAÇÃO: A planimetria é um método utilizado para avaliar a evolução da cicatrização de feridas. A planimetria computacional é um método ainda em experimentação, mas cujas vantagens têm sido demonstradas em várias investigações. OBJETIVOS: Avaliar os efeitos do ultra-som pulsado de baixa intensidade sobre a cicatrização de lesão cutânea produzida na região dorsal de ratos, por meio da planimetria computacional. MATERIAIS E MÉTODOS: Utilizou-se 60 ratos machos Wistar (peso médio de 300g) divididos em dois grupos com 30 animais cada, de acordo com o tratamento: 1) irradiação simulada (controle); 2) irradiação efetiva (Freqüência fundamental de 1,5MHz, freqüência de repetição de pulsos de 1KHz, largura de pulso de 200µs, intensidade de 30mW/cm² SATA, dez minutos de aplicação em dias alternados). Cada grupo foi subdividido em três grupos, de acordo com o período de irradiação ultra-sônica, de três, sete e 14 dias, respectivamente, e a cicatrização foi avaliada por meio da planimetria, um decalque da lesão sendo obtido em papel especial, digitalizado e medido ao computador por meio de um programa gráfico. Análise estatística pelo método não-paramétrico de Mann-Whitney. RESULTADOS: Houve aumento significante (p<0,05) da área cicatrizada no grupo 2 (141,88±18,50mm²) em relação ao grupo 1 (117,38±15,14mm²), no 14º dia. Não houve diferenças significantes entre os grupos nos demais períodos. CONCLUSÕES: O ultra-som pulsado de baixa intensidade estimula a cicatrização cutânea por segunda intenção em condições experimentais. A planimetria computacional mostrou-se um recurso de baixo custo, fácil manuseio e de aplicabilidade clínica.BACKGROUND: Planimetry is a method used to evaluate the progression of skin wound healing. Computerized planimetry is still an experimental method, but its advantages have been demonstrated in several investigations. OBJECTIVE: To evaluate the effects of low-intensity pulsed ultrasound on the healing of a skin lesion produced on the dorsal region of rats, by means of computerized planimetry. METHODS: Sixty male Wistar rats of mean weight 300g were used. They were divided into two groups according to the treatment applied: 1) simulated irradiation (control); 2) effective irradiation (fundamental frequency 1.5MHz, pulse repetition frequency 1KHz, pulse width 200µs, SATA intensity 30mW/cm² and application for ten minutes on alternate days). Each group was divided into three subgroups according to the length of time for which ultrasound irradiation was applied of three, seven and 14 days, respectively, and healing was evaluated by means of planimetry; a tracing of the wound was obtained on special paper and this was digitized and measured by means of a graphing software. Statistical analysis was performed using the Mann-Whitney non-parametric method. RESULTS: The healed area was significantly greater (p<0.05) in group 2 (141.88±18.50mm²) than in group 1 (117.38±15.14mm²) on the 14th day. There were no significant differences between the subgroups for the other experimental periods. CONCLUSIONS: Low-intensity pulsed ultrasound irradiation stimulated secondary skin healing under these experimental conditions. Computerized planimetry was shown to be a low cost method that was easy to use and present clinical applicability
Edades por trazas de fisión de circones provenientes de la Formación Saldaña, Valle Superior del Magdalena
El análisis por trazas de fisión en circones provenientes de muestras de zanja y corazones de los pozos: 1A, Suarez-1, Dina-12 perforados en el Valle Superior del Magdalena (VSM), permitió sugerir el límite máximo de depositación para la secuencia piroclástica de la Formación Saldaña en 137 Ma. Adicionalmente, se encontraron retrabajados en la Formación Saldaña circones con edades del Devónico-Carbonífero (356±16 Ma a 395±15 Ma); hasta comprobar que no hay rejuvenecimiento en esta edades no se descarta la posibilidad de que el área fuente sea más antigua. Cristales Jurásicos, provenientes de la erosión de bloques de la Formación Saldaña se encontraron además mezclados con circones del Cretáceo Inferior en el pozo Suarez- 1 y con cristales Miocenos en el pozo Dina 12.La retención de trazas en los circones indica que por lo menos a partir del Jurásico, la secuencia sedimentaria del VSM no ha sido afectada por eventos térmicos locales con temperaturas superiores a los 210±40°C (rango de temperatura para el inicio de borrado de trazas en el circón ).Fission track analyses were done on ditch cutting and core samples from wells 1A, Suarez-1 and Dina 12 drilled in the Upper Magdalena Valley. In 1A well: a population of crystals of Devonian-Carboniferous age (356±16 Ma to 395±15 Ma) occurs with a population of crystals of Early Cretacic age (137±6 Ma). In the Suarez-1 well zircons of Early Cretacic age (135.0 ± 5 Ma) were found. Finally, it was found in Dina 12 well a population of crystals of Early Cretacic age (141± 5 Ma) mixed with Tertiary crystals. Fission track ages between 137 and 141 Ma, are in agreement with published ages for the Saldaña Formation. Track retention in zircon indicates that, at least, from the Jurassic the sedimentary sequence has not been affected by thermal events over 210±20°C (maximum temperature of retention track range in zircon according to Zaun and Wagner, 1985)
Edades por trazas de fisión de circones provenientes de la Formación Saldaña, Valle Superior del Magdalena
El análisis por trazas de fisión en circones provenientes de muestras de zanja y corazones de los pozos: 1A, Suarez-1, Dina-12 perforados en el Valle Superior del Magdalena (VSM), permitió sugerir el límite máximo de depositación para la secuencia piroclástica de la Formación Saldaña en 137 Ma. Adicionalmente, se encontraron retrabajados en la Formación Saldaña circones con edades del Devónico-Carbonífero (356±16 Ma a 395±15 Ma); hasta comprobar que no hay rejuvenecimiento en esta edades no se descarta la posibilidad de que el área fuente sea más antigua. Cristales Jurásicos, provenientes de la erosión de bloques de la Formación Saldaña se encontraron además mezclados con circones del Cretáceo Inferior en el pozo Suarez- 1 y con cristales Miocenos en el pozo Dina 12.La retención de trazas en los circones indica que por lo menos a partir del Jurásico, la secuencia sedimentaria del VSM no ha sido afectada por eventos térmicos locales con temperaturas superiores a los 210±40°C (rango de temperatura para el inicio de borrado de trazas en el circón ).Fission track analyses were done on ditch cutting and core samples from wells 1A, Suarez-1 and Dina 12 drilled in the Upper Magdalena Valley. In 1A well: a population of crystals of Devonian-Carboniferous age (356±16 Ma to 395±15 Ma) occurs with a population of crystals of Early Cretacic age (137±6 Ma). In the Suarez-1 well zircons of Early Cretacic age (135.0 ± 5 Ma) were found. Finally, it was found in Dina 12 well a population of crystals of Early Cretacic age (141± 5 Ma) mixed with Tertiary crystals. Fission track ages between 137 and 141 Ma, are in agreement with published ages for the Saldaña Formation. Track retention in zircon indicates that, at least, from the Jurassic the sedimentary sequence has not been affected by thermal events over 210±20°C (maximum temperature of retention track range in zircon according to Zaun and Wagner, 1985)
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Model pruning in depth completion CNNs for forestry robotics with simulated annealing
In this article, we present an analysis of model compression in depth completion neural networks for forestry robotics, considering the increasing demands of real time autonomous solutions. Specifically, we implement a single state simulated annealing meta-heuristic for model pruning in the ENet and MSG-CHN neural networks for depth completion. We run experiments in three different datasets and analyze how different levels of pruning affect the accuracy and speed of the models. Experimental tests show that increasing sparsity has different effects depending on the neural network and dataset. ENet has negligible difference in accuracy and it would greatly benefit from lowering the amount of FLOPs, while MSG-CHN displays an inconsistent behavior depending on the dataset. This suggests that while both models benefit from model compression techniques, the optimal sparsity level depends on environment, dataset and neural network
Interpreting ambiguous ‘trace’ results in Schistosoma mansoni CCA Tests: Estimating sensitivity and specificity of ambiguous results with no gold standard
Background The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities. A point-of-care circulating cathodic antigen (CCA) test has been shown to be more sensitive than KK. However, CCA can return an ambiguous ‘trace’ result between ‘positive’ and ‘negative’, and much debate has focused on interpretation of traces results. Methodology/Principle findings We show how LCA can be extended to include ambiguous trace results and analyse S. mansoni studies from both Côte d’Ivoire (CdI) and Uganda. We compare the diagnostic performance of KK and CCA and the observed results by each test to the estimated infection prevalence in the population. Prevalence by KK was higher in CdI (13.4%) than in Uganda (6.1%), but prevalence by CCA was similar between countries, both when trace was assumed to be negative (CCAtn: 11.7% in CdI and 9.7% in Uganda) and positive (CCAtp: 20.1% in CdI and 22.5% in Uganda). The estimated sensitivity of CCA was more consistent between countries than the estimated sensitivity of KK, and estimated infection prevalence did not significantly differ between CdI (20.5%) and Uganda (19.1%). The prevalence by CCA with trace as positive did not differ significantly from estimates of infection prevalence in either country, whereas both KK and CCA with trace as negative significantly underestimated infection prevalence in both countries. Conclusions Incorporation of ambiguous results into an LCA enables the effect of different treatment thresholds to be directly assessed and is applicable in many fields. Our results showed that CCA with trace as positive most accurately estimated infection prevalence
Do we need another trial on exercise in patients with knee osteoarthritis?: No new trials on exercise in knee OA
© 2019 Osteoarthritis Research Society International Objective: We aim to investigate if we need additional trials on exercise in knee osteoarthritis (OA) to accept a certain effect size to be a ‘true’ effect size, and new studies are not needed anymore. Design: We performed a secondary analyses of a meta-analysis of studies on patients with knee osteoarthritis, on pain immediately post treatment. We performed five different analysis: a) we evaluated publication bias, b) we performed subgroup analysis, c) a sensitivity analysis based on the overall risk of bias (RoB) score, d) a cumulative meta-analysis and e) we developed an extended funnel plot to explore the potential impact of a new study on the summary effect estimate. Results: We included 42 studies with in total 6863 patients. The analyses showed that a) there is no clear publication bias, b) subgrouping did not affect the overall effect estimate, c) the effect estimate of exercise is more consistent (no heterogeneity) in the studies of low RoB, d) the benefit of exercise was clear since 2010 and e) the extended funnel plot suggests that an additional study has a none or very limited impact to change the current effect estimate. Conclusion: Exercise is effective and clinically worthwhile in reducing pain immediately post treatment compared to no or minimal interventions in patients with knee OA and adding new data will unlikely change this conclusion
RAPID AND RELIABLE HEALING OF CRITICAL SIZE BONE DEFECTS WITH GENETICALLY MODIFIED SHEEP MUSCLE
Large segmental defects in bone fail to heal and remain a clinical problem. Muscle is highly osteogenic, and preliminary data suggest that autologous muscle tissue expressing bone morphogenetic protein-2 (BMP-2) efficiently heals critical size defects in rats. Translation into possible human clinical trials requires, inter alia, demonstration of efficacy in a large animal, such as the sheep. Scale-up is fraught with numerous biological, anatomical, mechanical and structural variables, which cannot be addressed systematically because of cost and other practical issues. For this reason, we developed a translational model enabling us to isolate the biological question of whether sheep muscle, transduced with adenovirus expressing BMP-2, could heal critical size defects in vivo. Initial experiments in athymic rats noted strong healing in only about one-third of animals because of unexpected immune responses to sheep antigens. For this reason, subsequent experiments were performed with Fischer rats under transient immunosuppression. Such experiments confirmed remarkably rapid and reliable healing of the defects in all rats, with bridging by 2 weeks and remodelling as early as 3-4 weeks, despite BMP-2 production only in nanogram quantities and persisting for only 1-3 weeks. By 8 weeks the healed defects contained well-organised new bone with advanced neo-cortication and abundant marrow. Bone mineral content and mechanical strength were close to normal values. These data demonstrate the utility of this model when adapting this technology for bone healing in sheep, as a prelude to human clinical trials
Power-law solutions for TeVeS
The dynamics of TeVeS in a homogeneous and isotropic universe is shown to be
equivalent to the dynamics of an interacting two-component system, consisting
of a scalar field and a "fluid", related to the matter part, with explicitly
given coupling term. Scaling solutions (solutions with a constant ratio of the
energy densities of both components) in the "Einstein frame" are found which
are exponentially expanding or contracting with no remaining freedom for
Bekenstein's function. In the "physical frame" these solutions are of the
power-law type. An equivalent General Relativity (GR) picture of the dynamics
suggests that it is the scalar field which plays the role of dark matter, while
the "matter" has to mimic (phantom-type) dark energy.Comment: 24 pages, presentation improved, acepted for publication in
Class.Quantum Grav
Equilibrium random-field Ising critical scattering in the antiferromagnet Fe(0.93)Zn(0.07)F2
It has long been believed that equilibrium random-field Ising model (RFIM)
critical scattering studies are not feasible in dilute antiferromagnets close
to and below Tc(H) because of severe non-equilibrium effects. The high magnetic
concentration Ising antiferromagnet Fe(0.93)Zn(0.07)F2, however, does provide
equilibrium behavior. We have employed scaling techniques to extract the
universal equilibrium scattering line shape, critical exponents nu = 0.87 +-
0.07 and eta = 0.20 +- 0.05, and amplitude ratios of this RFIM system.Comment: 4 pages, 1 figure, minor revision
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