RESUMO
A novel photocatalytic method for the preparation of diarylmethyl silanes was reported through silyl radicals addition strategy to p-QMs (p-quinone methides). This protocol could tolerate a variety of functional groups affording the corresponding silylation products with moderate to excellent yields. The resulting silylation products could be easily converted into a series of bioactive GPR40 agonists and useful p-QMs precursors for the synthesis of compounds possessing both quaternary carbon centers and silicon substituents through simple operation. A plausible mechanism of silyl radicals to p-QMs was proposed on the basis of experimental results and previous literature.
RESUMO
BACKGROUND: Quantitative data are limited on the natural course of liver fibrosis in patients with chronic HBV infection (CHB). AIMS: To estimate the prevalence of fibrosis status including non-fibrosis, significant fibrosis, advanced fibrosis, and cirrhosis throughout the natural course of CHB. METHODS: We searched Cochrane library, EMBASE, PubMed, SCOPUS, Web of Science, and ScienceDirect from January 1993 to November 2019 for studies with histologic data on liver fibrosis in CHB natural course. CHB course was defined based on current criteria for identifying infection phases as recommended by international clinical practice guidelines, including the HBeAg-positive immune-tolerant, HBeAg-positive immune-active, HBeAg-negative immune-inactive, HBeAg-negative immune-reactive, and HBsAg-negative phases. Pooled prevalence rate of fibrosis status at each phase was obtained from random-effect meta-analyses. RESULTS: Thirty-three studies with 9,377 adult participants (23.8-49.0 age years; 45.5-88.6% males) were eligible and finally included. The estimated prevalence of non-fibrosis, significant fibrosis, advanced fibrosis, and cirrhosis was, for HBeAg-positive immune-tolerant phase: 31.2% (95%CI 15.6-46.7), 16.9% (95%CI 7.8-26.1), 5.4% (95%CI 0.0-11.2), and 0.0% (95%CI 0.0-1.5); HBeAg-positive immune-active phase: 6.9% (95%CI 3.6-10.2), 50.6% (95%CI 39.2-61.9), 32.1% (95%CI 24.2-40.0), and 12.8% (95%CI 8.6-17.0); HBeAg-negative immune-inactive phase: 32.4% (95%CI 0.0-100.0), 24.8% (95%CI 4.5-45.1), 3.0% (95%CI 0.0-8.3), and 0.0% (95%CI 0.0-1.0); and HBeAg-negative immune-reactive phase: 6.3% (95%CI 3.5-9.2), 50.3% (95%CI 38.9-61.7), 30.3% (95%CI 20.9-39.6), and 10.0% (95%CI 6.6-13.5), respectively. There was only one study for HBsAg-negative phase, thus not allowing further meta-analyses. CONCLUSIONS: Fibrosis risk persists through CHB natural course. These data can support risk estimation in clinical practice and provide reference for noninvasive investigation.
