520 research outputs found

    Operative Treatment of Isolated Bicondylar Hoffa Fracture With a Modified Swashbuckler Approach

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    Introduction: An isolated coronal fracture of either or both femoral condyles is a rare entity and is usually associated with high-energy injury trauma. Such fractures should be meticulously fixed for a good functional outcome as they involve the articular surface of a weight bearing joint. A modified swashbuckler approach provides adequate exposure for appropriate reduction and fixation of such fractures. Case Presentation: A 32-year-old male sustained a bicondylar Hoffa fracture of the right femur which was treated by open reduction and internal fixation using a modified swashbuckler approach. At two years of follow-up, the patient had excellent radiological and functional outcome. Conclusions: In our study, we treated this rare fracture successfully using a modified swashbuckler approach and found it to be a good approach for such fractures as compared to the conventional approach

    Fuzzy hierarchical segmentation

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    This paper introduces a new image thresholding method based on fuzzy sets theory. The membership function in the thresholding method is used to denote the characteristic relationship between a pixel and its belonging region (the object or background). To calculate these membership degrees, we propose an adaptation of the S-function. The proposed method is based on a hierarchical updating of the pixels membership values. In this way, we use an aggregation operator. The performance characteristics including accuracy, complexity and visual analysis of practical results are compared with classical methods.On propose dans ce travail une nouvelle méthode de seuillage d'image qui se base sur la théorie des sous-ensembles flous. Ainsi l'appartenance des pixels au fond ou à l'objet n'est plus absolue mais graduelle. Pour calculer les degrés d'appartenance des pixels à la classe fond ou à la classe objet, une adaptation de la fonction S de Zadeh est proposée. La méthode de seuillage proposée est fondée sur une mise à jour hiérarchique des degrés d'appartenance de chaque pixel. Dans cette optique un opérateur d'agrégation est utilisé. Les résultats du seuillage d'images présentant des degrés de complexité différents sont comparés à ceux obtenus par des méthodes plus classiques

    A newtonien operator for contrast enhancement

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    We propose in this work, a new local method to enhance image contrast. This method can be considered as member of convolution filters set, but present the originality of the adaptative found of convolution mask coefficients. Further more, in this method, the grey level distribution of pixels in the neighbourhood of the current pixel is considered as 1/r 2 distribution, which was deduced from the Newtonian model. Where r is a hybrid distance, which involves the spatial information and the luminance one. The results of the application of the proposed method over different grey level images with different levels of complexity were compared with those obtained by classical methods.Nous proposons dans ce travail une méthode locale d'amélioration de contraste. Cette méthode peut être cataloguée dans la famille des filtres par convolution, dont la singularité réside dans le choix des coefficients du masque de convolution qui ne sont pas fixés à l'avance mais déterminés de façon adaptative. L'originalité de ce modèle est basée sur l'application du principe fondamental de la dynamique. La distribution des niveaux de gris des pixels appartenant à une fenêtre d'observation centrée autour d'un pixel à traiter subit une pondération en l/r 2 inspiré du modèle newtonien. La distance r représente une distance hybride faisant intervenir à la fois l'information spatiale et l'information luminance. Les résultats de l'application de cette méthode sont montrés sur des images à niveaux de gris à complexités différentes, puis comparés à ceux donnés par des méthodes plus classiques

    Spatial and temporal variation of hydraulic conductivity and vegetation growth in green infrastructures using infiltrometer and visual technique

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    Hydraulic conductivity of a vegetated soil (i.e., mixed grass cover) is an important parameter governing the hydrological performance of green infrastructure (GI). This paper focuses on GI with mixed grass cover in the presence of trees. Due to shading effects (interception of radiant energy) of tree canopy, mixed grass cover in the vicinity of trees may not receive direct photosynthetically active radiation (PAR). This can hinder the growth rates resulting in the low grass cover (i.e., in density). The hydraulic conductivity and the performance of GI can be further affected. Several field studies were conducted to investigate hydraulic conductivity in different types of vegetated covers. However, any variation in growth and hydraulic conductivity of mixed grass cover in the vicinity of trees was rarely investigated. The objective of this study is to quantify spatial and temporal variation of vegetation growth and hydraulic conductivity in a mixed grass cover in the vicinity of a tree. Field monitoring of a mixed grass cover in the vicinity of a tree in a GI was conducted for about six months. Hydraulic conductivity tests were carried out using mini disk infiltrometer (MDI) at 149 locations in a selected site once every month. Vegetation density was quantified using image analysis and the images were captured by a DJI Phantom drone. The growth of mixed grass cover around tree vicinity (within 5 m radial distance) was found to be more uniform during months characterized by high rainfall depth. Spatial heterogeneity in both vegetation density and hydraulic conductivity is found to be more significant during a dry period than wet period. Variation of hydraulic conductivity with respect to the change in vegetation density is found to be significant in a wet period than dry period. It is also found that hydraulic conductivity is higher at the portions where shredded leaves are present. The obtained dynamic spatio-temporal relationship of soil, vegetation and atmospheric parameters can support the design of green infrastructures and contribute to a better understanding of the maintenance practices

    Agents with inotropic properties for the management of acute heart failure syndromes. Traditional agents and beyond

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    Treatment with inotropic agents is one of the most controversial topics in heart failure. Initial enthusiasm, based on strong pathophysiological rationale and apparent empirical efficacy, has been progressively limited by results of controlled trials and registries showing poorer outcomes of the patients on inotropic therapy. The use of these agents remains, however, potentially indicated in a significant proportion of patients with low cardiac output, peripheral hypoperfusion and end-organ dysfunction caused by heart failure. Limitations of inotropic therapy seem to be mainly related to their mechanisms of action entailing arrhythmogenesis, peripheral vasodilation, myocardial ischemia and damage, and possibly due to their use in patients without a clear indication, rather than to the general principle of inotropic therapy itself. This review will discuss the characteristics of the patients with a potential indication for inotropic therapy, the main data from registries and controlled trials, the mechanism of the untoward effects of these agents on outcomes and, lastly, perspectives with new agents with novel mechanisms of action

    Judging enzyme-responsive micelles by their covers : direct comparison of dendritic amphiphiles with different hydrophilic blocks

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    Enzymatically degradable polymeric micelles have great potential as drug delivery systems, allowing the selective release of their active cargo at the site of disease. Furthermore, enzymatic degradation of the polymeric nanocarriers facilitates clearance of the delivery system after it has completed its task. While extensive research is dedicated toward the design and study of the enzymatically degradable hydrophobic block, there is limited understanding on how the hydrophilic shell of the micelle can affect the properties of such enzymatically degradable micelles. In this work, we report a systematic head-to-head comparison of well-defined polymeric micelles with different polymeric shells and two types of enzymatically degradable hydrophobic cores. To carry out this direct comparison, we developed a highly modular approach for preparing clickable, spectrally active enzyme-responsive dendrons with adjustable degree of hydrophobicity. The dendrons were linked with three different widely used hydrophilic polymers-poly(ethylene glycol), poly(2-ethyl-2-oxazoline), and poly(acrylic acid) using the CuAAC click reaction. The high modularity and molecular precision of the synthetic methodology enabled us to easily prepare well-defined amphiphiles that differ either in their hydrophilic block composition or in their hydrophobic dendron. The micelles of the different amphiphiles were thoroughly characterized and their sizes, critical micelle concentrations, drug loading, stability, and cell internalization were compared. We found that the micelle diameter was almost solely dependent on the hydrophobicity of the dendritic hydrophobic block, whereas the enzymatic degradation rate was strongly dependent on the composition of both blocks. Drug encapsulation capacity was very sensitive to the type of the hydrophilic block, indicating that, in addition to the hydrophobic core, the micellar shell also has a significant role in drug encapsulation. Incubation of the spectrally active micelles in the presence of cells showed that the hydrophilic shell significantly affects the micellar stability, localization, cell internalization kinetics, and the cargo release mechanism. Overall, the high molecular precision and the ability of these amphiphiles to report their disassembly, even in complex biological media, allowed us to directly compare the different types of micelles, providing striking insights into how the composition of the micelle shells and cores can affect their properties and potential to serve as nanocarriers

    Obstructive sleep apnea and electrocardiographic P-wave morphology.

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    INTRODUCTION: Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder with important cardiovascular implications. Left atrial abnormality can be identified by electrocardiographic P-wave morphology and is considered an important risk for atrial fibrillation (AF) and stroke, both of which have been associated with OSA. We hypothesized that severity of OSA would be associated with more abnormal electrocardiographic P-wave morphology as indicated by P-wave terminal force in V METHODS: Patients who underwent clinically indicated polysomnography and had 12-lead ECG were identified through medical record review. Logistic regression was used to determine the associations between the measures of OSA severity (apnea hypopnea index [AHI] and mean nocturnal oxygen [O RESULTS: A total of 261 patients (mean age: 57 years old, male: 52%) were included in the study. Multivariate analysis showed that AHI was associated with abnormal PTFV CONCLUSION: In a sleep clinic cohort, there was significant association between OSA severity and ECG-defined left atrial abnormality

    Prescription opioid use before and after kidney transplant: Implications for posttransplant outcomes

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146648/1/AJT14714-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146648/2/ajt14714_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146648/3/ajt14714.pd
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