Initial attachment of osteoblasts to various guided bone regeneration membranes: an in vitro study

Guided bone regeneration (GBR) has proved to be a suitable and somehow predictable technique for promoting bone regeneration. Avariety of synthetic and naturally derived GBR barriers have been used in clinics to facilitate bone regeneration. These barriers may differ in composition and structure and these may affect the outcomes of GBR. Therefore, the present study was undertaken to evaluate the in vitro ability of osteoblasts (MC3T3-E1) to attach to various GBR membranes. Materials and methods:  Six GBR/GTR (guided tissue regeneration) membranes [BioMend ® (BM), Resolut ® (RL), Guidor ® (GD), EpiGuide ® (EG), Gore-Tex ® (GT) and Millipore filter ® (MP)] were tested. For controls, cells were directly plated on culture dishes (CD). Each test membrane was secured to the bottom of a culture dish with a double-sided adhesive tape. All samples were triplicate. At 1.5 and 24 h after plating of 2 ml (5 × 10 4 cells/ml) of MC3T3-E1 (passage 7) cells, the specimens were rinsed with phosphate-buffered saline to wash out any unattached cells and then fixed with a 10% buffered formalin solution for 1 d. After washing with distilled water, the cells were stained with hematoxylin. The number of attached cells was counted under a light microscope equipped with an ocular-micrometer in a unit area of 0.25 mm 2 (five areas on each membrane). In addition, cell morphology attached to the membranes was evaluated under scanning electron microscope. Results:  Data were presented as mean ± standard error and analyzed for statistical difference using a generalized Wilcoxon's test. Cell attachment at 1.5 h was as follows: MP (27.5 ± 2.1) > RL (17.0 ± 1.4) ≈ BM (14.5 ± 1.4) ≈ EG (11.4 ± 1.0) > GD (5.2 ± 0.8) ≈ GT (3.1 ± 0.6); and at 24 h was: MP (67.6 ± 3.6) > RL (35.8 ± 1.8) > BM (15.4 ± 0.9) ≈ EG (13.3 ± 1.3) > GD (5.9 ± 0.7) ≈ GT (5.6 ± 1.3). At 24 h, the scanning electron microscope finding revealed that cells attached on MP, RL, BM and EG were flatter in shape, like cells on CD, than cells on GD and GT, where cells were rather round. Conclusions:  Results from this study suggested that MP, BM, RL and EG enhanced the early osteoblast attachment. However, the true benefit of this observation in clinic remains to be determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65252/1/j.1600-0765.2002.01625.x.pd

Performance of the Charge Injection Capability of Suzaku XIS

A charge injection technique is applied to the X-ray CCD camera, XIS (X-ray Imaging Spectrometer) onboard Suzaku. The charge transfer inefficiency (CTI) in each CCD column (vertical transfer channel) is measured by the injection of charge packets into a transfer channel and subsequent readout. This paper reports the performances of the charge injection capability based on the ground experiments using a radiation damaged device, and in-orbit measurements of the XIS. The ground experiments show that charges are stably injected with the dispersion of 91eV in FWHM in a specific column for the charges equivalent to the X-ray energy of 5.1keV. This dispersion width is significantly smaller than that of the X-ray events of 113eV (FWHM) at approximately the same energy. The amount of charge loss during transfer in a specific column, which is measured with the charge injection capability, is consistent with that measured with the calibration source. These results indicate that the charge injection technique can accurately measure column-dependent charge losses rather than the calibration sources. The column-to-column CTI correction to the calibration source spectra significantly reduces the line widths compared to those with a column-averaged CTI correction (from 193eV to 173eV in FWHM on an average at the time of one year after the launch). In addition, this method significantly reduces the low energy tail in the line profile of the calibration source spectrum.Comment: Paper contains 18 figures and 15 tables. Accepted for publication in PAS

Financial Assessment Considered Weighting Factor Scenarios for the Optimal Combination of Power Plants on the Power System Operation

This paper presents an application of the novel evolutionary algorithm for assessing financially an economic power system operation throughout a combined economic and emission dispatch problem required by various technical limitations. In detail, this problem considers two dispatches for fuel and environmental aspects as a constrained objective function associated with weighting factor scenarios. Running out simulations show that minimum costs are depended on weighting factors, which implemented on the combination of the problem. Reducing the total fuel cost focused on the dispatching priority and the pollutant target based on the emission production have difference implications as its contribution to the economic operation, the increasing load demand leads to generated powers, costs and emission discharges associated with its parameters and power schedules