Nucleic acids are considered as perfect programmable materials for cascade signal amplification and not merely as genetic information carriers. Among them, catalytic hairpin assembly (CHA), an enzyme‐free, high‐efficiency, and isothermal amplification method, is a typical example. A typical CHA reaction is initiated by single‐stranded analytes, and substrate hairpins are successively opened, resulting in thermodynamically stable duplexes. CHA circuits, which were first proposed in 2008, present dozens of systems today. Through in‐depth research on mechanisms, the CHA circuits have been continuously enriched with diverse reaction systems and improved analytical performance. After a short time, the CHA reaction can realize exponential amplification under isothermal conditions. Under certain conditions, the CHA reaction can even achieve 600 000‐fold signal amplification. Owing to its promising versatility, CHA is able to be applied for analysis of various markers in vitro and in living cells. Also, CHA is integrated with nanomaterials and other molecular biotechnologies to produce diverse readouts. Herein, the varied CHA mechanisms, hairpin designs, and reaction conditions are introduced in detail. Additionally, biosensors based on CHA are presented. Finally, challenges and the outlook of CHA development are considered.

No abstract

Congenital heart disease (CHD) is a common structural birth defect worldwide, and defects typically occur in the walls and valves of the heart or enlarged blood vessels. Chromosomal abnormalities and genetic mutations only account for a small portion of the pathogenic mechanisms of CHD, and the etiology of most cases remains unknown. The role of epigenetics in various diseases, including CHD, has attracted increased attention. The contributions of DNA methylation, one of the most important epigenetic modifications, to CHD have not been illuminated. Increasing evidence suggests that aberrant DNA methylation is related to CHD. Here, we briefly introduce DNA methylation and CHD and then review the DNA methylation profiles during cardiac development and in CHD, abnormalities in maternal genome-wide DNA methylation patterns are also described. Whole genome methylation profile and important differentially methylated genes identified in recent years are summarized and clustered according to the sample type and methodologies. Finally, we discuss the novel technology for and prospects of CHD-related DNA methylation.

Our observations suggest that serum miR-483-5p and miR-500a might serve as novel, noninvasive biomarkers for HCC. Serum miR-483-5p might complement AFP in detecting HCC.

No abstract

To identify drugs that are potentially used for the treatment of COVID-19, the potency of 1403 FDA-approved drugs were evaluated using a robust pseudovirus assay and the candidates were further confirmed by authentic SARS-CoV-2 assay. Four compounds, Clomiphene (citrate), Vortioxetine, Vortioxetine (hydrobromide) and Asenapine (hydrochloride), showed potent inhibitory effects in both pseudovirus and authentic virus assay. The combination of Clomiphene (citrate), Vortioxetine and Asenapine (hydrochloride) is much more potent than used alone, with IC50 of 0.34 μM.

BackgroundTo determine reference intervals for serum levels of human epididymis protein 4 (HE4) in Chinese women.MethodsIn this multicenter (n = 9) study, 618 healthy women, 767 patients with non-malignant diseases, and 951 patients with malignant tumors were enrolled. Serum levels of HE4 were measured in all patients using electrochemiluminescence immunoassays. The influence of age, menopause, malignancy status and other characteristics on the levels of HE4 was evaluated using univariate and multivariate analyses. Confidence intervals (2.5–97.5 %) were determined in different populations.ResultsThere were significant differences in HE4 levels among groups with different ages, menopause or malignancy status. Higher levels of HE4 were detected in elder compared to younger, post- compare to pre- menopause and malignant compared to benign subjects. Multivariate analysis showed that menopause and malignancy status, as well as smoking and pelvic masses were independent factors involved in serum HE4 levels. In pre-menopause stage, the reference ranges of HE4 level were 29.30–68.79, 28.12–1284.83 and 34.75–981.91 pmol/L in healthy, benign and malignant populations, respectively. In post-menopause stage, the reference ranges are 35.96–114.43, 39.11–2208.70 and 39.40–1678.13 pmol/L for those populations.ConclusionsThe present study has established the reference intervals of HE4 levels in pre- and post-menopause populations with different malignancy status.Electronic supplementary materialThe online version of this article (doi:10.1186/s13048-015-0201-z) contains supplementary material, which is available to authorized users.

p62 expression is common in carcinomas of the digestive system and higher in carcinomas of the gastrointestinal tract than in primary HCC. p62 is a cellular differentiation-related protein. Cancer cells with a high p62 expression exhibited highgrowth fractions in HCC.