A meta-analysis was performed to assess and compare the accuracies of magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI) for the staging of hepatic fibrosis. Online journal databases and a manual search from January 2000 to May 2011 were used. We identified 41 studies, but only 14 met the criteria to perform a meta-analysis assessing MRE (five trials) or DWI (10 trials). Fibrosis was categorized by redistribution into five stages according to histopathological description. A bivariate binomial model was used to combine the sensitivity and specificity and their 95% confidence intervals (CIs), from which diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and summary receiver operating characteristic (sROC) were derived to indicate the diagnostic accuracy of imaging modalities. With MRE, the sensitivity, specificity, DOR, PLR, NLR, and area under sROC curve (with 95% CIs) for staging F0 $ A z test demonstrated that MRE had a significantly higher accuracy than DWI in those indicators (P < 0.05). Conclusion: MRE is more reliable for staging hepatic fibrosis, compared with DWI, with a high combination of sensitivity, specificity, likelihood ratios, DOR, and area under sROC curve. (HEPATOLOGY 2012;56:239-247)
Two azo substituted achiral bent-core mesogens have been synthesized. Optical polarizing microscopy and synchrotron X-ray scattering studies of both compounds reveal the existence of the thermotropic uniaxial and biaxial nematic and three smectic phases at different temperatures in these single component small molecule systems. The transition from the uniaxial to biaxial nematic phase is confirmed to be second order. The transitions from the biaxial nematic to the underlying smectic phase and between the smectic phases have barely discernible heat capacity signatures and thus are also second order.
New methods capable of effecting cyclization, and forming novel three-dimensional structures while maintaining favourable physicochemical properties are needed to facilitate the development of cyclic peptide-based drugs that can engage challenging biological targets, such as protein-protein interactions. Here, we report a highly efficient and generally applicable strategy for constructing new types of peptide macrocycles using palladium-catalysed intramolecular C(sp)-H arylation reactions. Easily accessible linear peptide precursors of simple and versatile design can be selectively cyclized at the side chains of either aromatic or modified non-aromatic amino acid units to form various cyclophane-braced peptide cycles. This strategy provides a powerful tool to address the long-standing challenge of size- and composition-dependence in peptide macrocyclization, and generates novel peptide macrocycles with uniquely buttressed backbones and distinct loop-type three-dimensional structures. Preliminary cell proliferation screening of the pilot library revealed a potent lead compound with selective cytotoxicity toward proliferative Myc-dependent cancer cell lines.
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