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The number of available 3D models in various areas increases steadily. Effective methods to search for those 3D models by content, rather than textual annotations are crucial. For this purpose, we propose a new approach for content based 3D model retrieval by hand-drawn sketch images. This approach to retrieve visually similar mesh models from a large database consists of three major steps: (1) suggestive contour renderings from different viewpoints to compare against the user drawn sketches; (2) descriptor computation by analyzing diffusion tensor fields of suggestive contour images, or the query sketch respectively; (3) similarity measurement to retrieve the models and the most probable view-point from which a model was sketched. Our proposed sketch based 3D model retrieval system is very robust against variations of shape, pose or partial occlusion of the user drawn sketches. Experimental results are presented and indicate the effectiveness of our approach for sketch-based 3D model retrieval

In this paper, we describe three methods to improve the performance of pressure-driven laminar flow-based microreactors by manipulating reaction-depletion boundary layers to overcome mass transfer limitations at reactive surfaces on the walls, such as electrodes. The transport rate of the reactants to the reactive surfaces is enhanced by (i) removing the depleted zone through multiple periodically-placed outlets; (ii) adding fresh reactants through multiple periodically-placed inlets along the reactive surface; or (iii) producing a spiraling, transverse flow through the integration of herringbone ridges along the channel walls. For approaches (i) and (ii), the network of microfluidic channels needs to be designed such that under the operating conditions used the right amount of boundary layer at each outlet or inlet is removed or replenished, respectively. Here, we report a set of design rules, derived with the help of a fluidic resistance circuit model, to aid in the design of appropriate microfluidic networks. Also, the actual enhancement of the performance of the electrochemical microreactor, i.e. chemical conversion efficiency, using multiple inlets, multiple outlets, or herringbone ridges is reported.

It has been hypothesized that transforming growth factor-beta1 (TGF-beta1) signalling is involved in erectile dysfunction (ED). This study was undertaken to elucidate in detail whether expression of TGF-beta1 and its type II receptor is clinically related to various causes of ED. Fifty-four patients with ED and 24 potent men were the subjects of this study. After multidisciplinary work-up, the ED was classified as psychogenic (n = 6), neurogenic (n = 15), or vasculogenic (n = 33). In every subject, percutaneous cavernous biopsy was performed using a Biopty gun. Masson's trichrome staining was used to quantitate collagen fibres and immunohistochemical staining to evaluate both TGF-beta1 and its type II receptor by scoring the intensity of immunoreactivity (score 0-6). Collagen fibres were significantly more abundant in men with vasculogenic ED (72.7 +/- 17.7%) than in control subjects (43.3 +/- 11.2%) or those with psychogenic (45.0 +/- 12.2%) or neurogenic (51.3 +/- 20.3%) ED (p < 0.01). Expression of TGF-beta1 was significantly greater in vasculogenic ED (4.3 +/- 1.3) than in the control subjects (2.4 +/- 0.9) or psychogenic ED (2.0 +/- 0.6) groups (p < 0.01). Type II receptor expression was also significantly increased in vasculogenic ED (3.9 +/- 1.3) compared with control (2.2 +/- 0.7) and psychogenic (2.2 +/- 0.8) or neurogenic (2.6 +/- 1.3) ED (p < 0.01). Of the ED groups, both the hyperlipidaemia and the atherosclerosis patients showed significantly more fibrosis than those without the condition (p < 0.05). The abundance of collagen fibres correlated well with both TGF-beta1 expression (gamma = 0.81; p < 0.001) and receptor II expression (gamma = 0.83; p < 0.001). These results suggest that TGF-beta1 and its receptor II pathway are involved in cavernous fibrosis and ED in man. Patients with vascular risk factors such as hyperlipidaemia and atherosclerosis are liable to ED by activation of this pathway.

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