31 research outputs found
Comparison of self-administration behavior and responsiveness to drug-paired cues in rats running an alley for intravenous heroin and cocaine
Three-dimensional analysis of cortical bone structure using X-ray micro-computed tomography
We demonstrate the capability of X-ray micro-computed tomography to image the micro-structure of human cortical bone. At 5 μm voxel size we observe the complex morphology of the Haversian network in three dimensions. The local thickness of Haversian canals is measured using a maximal sphere algorithm and found to have a bimodal signature and a mean radius of 19.2 μm. The intra-cortical porosity due to Haversian canals is measured as 3.0%. Both results are in agreement with traditional histomorphometric measurements. We show that at higher resolutions one can resolve the spatial distribution of lacunae in cortical bone. © 2004 Elsevier B.V. All rights reserved
Augmentation of Pulmonary Vein Backflow Velocity during Left Atrial Contraction: A Novel Phenomenon Responsible for Progression of Atrial Fibrillation in Hypertensive Patients
Revisiting long‐access versus short‐access cocaine self‐administration in rats: intermittent intake promotes addiction symptoms independent of session length
Shared medical appointments as a new model for carpal tunnel surgery consultation: A randomized clinical trial
Scaffold percolative efficiency: in vitro evaluation of the structural criterion for electrospun mats
Fibrous scaffolds of engineered structures can be chosen as promising porous environments when an approved criterion validates their applicability for a specific medical purpose. For such biomaterials, this paper sought to investigate various structural characteristics in order to determine whether they are appropriate descriptors. A number of poly(3-hydroxybutyrate) scaffolds were electrospun; each of which possessed a distinguished architecture when their material and processing conditions were altered. Subsequent culture of mouse fibroblast cells (L929) was carried out to evaluate the cells viability on each scaffold after their attachment for 24 h and proliferation for 48 and 72 h. The scaffolds’ porosity, pores number, pores size and distribution were quantified and none could establish a relationship with the viability results. Virtual reconstruction of the mats introduced an authentic criterion, “Scaffold Percolative Efficiency” (SPE), with which the above descriptors were addressed collectively. It was hypothesized to be able to quantify the efficacy of fibrous scaffolds by considering the integration of porosity and interconnectivity of the pores. There was a correlation of 80% as a good agreement between the SPE values and the spectrophotometer absorbance of viable cells; a viability of more than 350% in comparison to that of the controls