589 research outputs found
Air-leak management after upper lobectomy in patients with fused fissure and chronic obstructive pulmonary disease: a pilot trial comparing sealant and standard treatment
A pilot trial to compare the efficacy of two different procedures to prevent postoperative air-leak in chronic obstructive pulmonary disease (COPD) patients submitted to upper lobectomy for non-small cell lung cancer. Sixty patients with COPD and lung cancer at the upper pulmonary lobes eligible for lobectomy were enrolled and randomly assigned either to standard treatment (ST) with stapling device or to electrocautery dissection and application of a collagen patch coated with human fibrinogen and thrombin (TachoSil) (experimental treatment [ET]) for the intra-operative completion of their fused fissures. Thirty patients were enrolled in each group during a three-year period. Preoperative characteristics were similar between the two groups. Statistically significant reduction of air-leak was registered in the ET group when overall incidence of postoperative air-leak (55% vs. 96%; P=0.03), postoperative air-leak (mean 1.63+/-1.96 vs. 4.33+/-4.12 days; P=0.0018), chest-drain (mean 3.53+/-1.59 vs. 5.90+/-3.72 days; P=0.0021) and hospital stay duration (mean 5.87+/-1.07 vs. 7.50+/-3.20 days; P=0.01) were considered. The use of TachoSil to prevent postoperative air-leak after interlobar fissure completion in patients with COPD submitted to upper lobectomy seems to be safe and more effective than the ST based on stapling device application
Surface reactivity and silanization ability of borosilicate and Mg-Sr-based bioactive glasses
Processing methods for making porous bioactive glass-based scaffolds—A state-of-the-art review
Robocasting of SiO2-based bioactive glass scaffolds with porosity gradient for bone regeneration and potential load-bearing applications
Boundedness and Stability of Impulsively Perturbed Systems in a Banach Space
Consider a linear impulsive equation in a Banach space
with . Suppose each solution of
the corresponding semi-homogeneous equation
(2) is bounded for any bounded sequence .
The conditions are determined ensuring
(a) the solution of the corresponding homogeneous equation has an exponential
estimate;
(b) each solution of (1),(2) is bounded on the half-line for any bounded
and bounded sequence ;
(c) for any tending to
zero;
(d) exponential estimate of implies a similar estimate for .Comment: 19 pages, LaTex-fil
Mechanical Properties of Robocast Glass Scaffolds Assessed through Micro-CT-Based Finite Element Models
In this study, the mechanical properties of two classes of robocast glass scaffolds are obtained through Computed micro-Tomography (micro-CT) based Finite Element Modeling (FEM) with the specific purpose to explicitly account for the geometrical defects introduced during manufacturing. Both classes demonstrate a fiber distribution along two perpendicular directions on parallel layers with a (Formula presented.) tilting between two adjacent layers. The crack pattern identified upon compression loading is consistent with that found in experimental studies available in literature. The finite element models have demonstrated that the effect of imperfections on elastic and strength properties may be substantial, depending on the specific type of defect identified in the scaffolds. In particular, micro-porosity, fiber length interruption and fiber detaching were found as key factors. The micro-pores act as stress concentrators promoting fracture initiation and propagation, while fiber detachment reduces the scaffold properties substantially along the direction perpendicular to the fiber plane
Optical properties of polystyrene-ZnO nanocomposite scattering layer to improve light extraction in organic light-emitting diode
In this work, experimental measurements on polystyrene-ZnO nanocomposite scattering films and on organic light-emitting device with and without the scattering layers are presented. The results are also compared with Henyey-Greenstein radiative-transfer model to narrow down the parameters that can be important in the identification of more suitable scattering layers. As a result, an increase of efficiency of about 30% has been obtained that it can be translated in 60% of outcoupled light in respect to the total generated amount
In Vivo Evaluation of 3D-Printed Silica-Based Bioactive Glass Scaffolds for Bone Regeneration
Bioactive glasses are often designed as porous implantable templates in which newly-formed bone can grow in three dimensions (3D). This research work aims to investigate the bone regenerative capability of silicate bioactive glass scaffolds produced by robocasting in comparison with powder and granule-like materials (oxide system: 47.5SiO2-10Na2O-10K2O-10MgO-20CaO-2.5P2O5, mol.%). Morphological and compositional analyses performed by scanning electron microscopy (SEM), combined with energy dispersive spectroscopy (EDS) after the bioactivity studies in a simulated body fluid (SBF) confirmed the apatite-forming ability of the scaffolds, which is key to allowing bone-bonding in vivo. The scaffolds exhibited a clear osteogenic effect upon implantation in rabbit femur and underwent gradual resorption followed by ossification. Full resorption in favor of new bone growth was achieved within 6 months. Osseous defect healing was accompanied by the formation of mature bone with abundant osteocytes and bone marrow cells. These in vivo results support the scaffold’s suitability for application in bone tissue engineering and show promise for potential translation to clinical assessment
Surface Properties and Antioxidant Activity of Silicate and Borosilicate Bioactive Glasses
Herein, silicate and borosilicate bioactive glasses are synthetized and characterized. The antioxidant activity, in the presence and absence of human osteoblasts' progenitor cells, of the different glass compositions, is correlated to the surface properties: wettability, zeta potential, hydroxylation degree, reactivity in simulated body fluid (SBF), and Tris buffer. An enhancing effect of boron in glass reactivity and a stabilizing role of Sr and Mg are evidenced. The scavenging potential of the analyzed bioactive glasses toward reactive oxygen species (ROS) is clearly proved. Moreover, cellular tests confirm the protective effect of the bioactive glasses toward viable cells acting as ROS/RNS species scavenger. The obtained results represent an original improvement of the knowledge concerning the intrinsic antioxidant ability of bioactive glasses with different compositions and the mechanisms involved
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