Abstract: The disclosure discloses an irreversible covalent organic framework for efficient and selective gold recovery and a preparation method thereof, and belongs to the technical field of precious metal recovery from an aqueous solution. In the disclosure, metal trifluoromethanesulfonate is used as a catalyst, and a solvothermal method is used to prepare a mother covalent organic framework, and then the corresponding structural unit is used to perform an exchange reaction to prepare an irreversible amide-linked covalent organic framework material. The disclosure solves the problem of preparation of high-stability irreversible covalent organic framework, the introduced amide bond gives the covalent organic framework the ability to quickly and selectively recover precious metal gold from an aqueous solution, and the covalent organic framework can be used repeatedly.

Abstract: Biomarkers of lung disease are provided. The biomarkers comprise target genomic DNA sequences having one or more CpG dinucleotides that are differentially methylated in genomic DNA of subjects having lung disease as compared to normal subjects or subjects not having lung disease. In one exemplary embodiment, methylation status profiles of 71 CpG sites mapping to 67 unique genes are significantly associated with at least one of three lung function decline measures associated with lung disease. Other biomarkers significantly associated with cigarette smoking-related lung function decline, with age-related lung function decline, and with the intensifying effects of cigarette smoking on lung function decline with age are also provided.