Fabricating Ti alloy based dental implants with defined porous scaffold structure is a promising strategy for improving the osteoinduction of implants. In this study, we use Laser Beam Melting (LBM) 3D printing technique to fabricate porous Ti6Al4V dental implant prototypes with three controlled pore sizes (200, 350 and 500 μm). The mechanical stress distribution in the surrounding bone tissue is characterized by photoelastography and associated finite element simulation. For in-vitro studies, experiments on implants’ biocompatibility and osteogenic capability are conducted to evaluate the cellular response correlated to the porous structure. As the preliminary results, porous structured implants show a lower stress-shielding to the surrounding bone at the implant neck and a more densed distribution at the bottom site compared to the reference implant. From the cell proliferation tests and the immunofluorescence images, 350 and 500 μm pore sized implants demonstrate a better biocompatibility in terms of cell growth, migration and adhesion. Osteogenic genes expression of the 350 μm group is significantly increased alone with the ALP activity test. All these suggest that a pore size of 350 μm provides an optimal provides an optimal potential for improving the mechanical shielding to the surrounding bones and osteoinduction of the implant itself.
Aim: To systematically evaluate the accuracy of contrast-enhanced ultrasonography (CEUS) for the detection of gallbladder carcinoma. Material and method: Relevant studies were identified searching PubMed, Embase, Elsevier, the CNKI (China National Knowledge Infrastructure) database and the Cochrane Trial Register searches until August 2015. Patient clinical characteristics, sensitivity and specificity were extracted. The summary receiver operating characteristic (ROC) curve was used to examine the accuracy of CEUS. A meta-analysis was performed to evaluate the clinical utility in the diagnosis of gallbladder carcinoma. Sensitivity analysis was performed after omitting outliers identified in a bivariate boxplot and publication bias was assessed with Egger testing. Results: From 89 citations, 16 were included in the meta-analysis with a total of 1673 lesions. We detected heterogeneity between studies and evidence of publication bias. The methodological quality was moderate. The pooled weighted sensitivity with a corresponding 95% confidence interval (CI) was 0.92 (95%CI: 0.90, 0.94), the specificity was 0.91 (95%CI: 0.89, 0.93), the positive likelihood ratio was 10.01 (95%CI: 7.02, 14.29), the negative likelihood ratio was 0.10 (95%CI: 0.07, 0.14), and the diagnostic odds ratio was 123.02 (95%CI: 78.40, 193.03). The area under the ROC curve was 0.9689 (95%CI: 0.9376, 0.9879). Conclusions: CEUS is a reliable, non-invasive, and no-radiation-exposure imaging modality with a high sensitivity and specificity for detection of gallbladder carcinoma. Nonetheless, it should be applied cautiously, and large scale, well-designed trials are necessary to assess its clinical value.
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