Circ_0004771 Promotes Hypoxia/Reoxygenation Induced Cardiomyocyte Injury via Activation of Mitogen-Activated Protein Kinase Signaling Pathway.

This study aimed to observe the mechanism and effect of circ_0004771 on cardiomyocyte injury in acute myocardial infarction (AMI). The differences in circ_0004771 expression in the blood of AMI patients and healthy volunteers were observed by Real-Time Quantitative Reverse Transcription-Polymerase Chain Reaction. AMI cell models were constructed by hypoxia/reoxygenation (H/R)-induced injury in human cardiomyocytes (AC16 cells). The changes of circ_0004771 expression in AMI cells were observed. After transfection with the knockdown or overexpression of circ_0004771 vector in AMI cells, Cell Counting Kit-8 (CCK-8) assay and propidium iodide/FITC-Annexin V staining were performed to detect cell proliferation and apoptosis levels, extracellular lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) concentration, and superoxide dismutase (SOD) activity. Expression levels of Mitogen-activated protein kinase (MAPK) signaling pathway-related proteins (p-MEK1/2, MEK1/2, p-ERK1/2, ERK1/2), and endoplasmic reticulum (ER) stress proteins (GRP78 and CHOP-1) were observed in each group of cells by western blot method. The expression level of circ_0004771 was significantly reduced in both clinical samples and cells of AMI. When circ_0004771 was knocked down in AMI cells, it resulted in a decrease in cell proliferation level and significant increase in apoptosis level. The inhibition of circ_0004771 expression caused leakage of LDH in AMI cells, accumulation of intracellular MDA, and inhibition of SOD activity. In addition, the knockdown of circ_0004771 significantly increased the levels of p-MEK1/2, p-ERK1/2, GRP78, and CHOP-1 in H/R-induced AC16 cells. However, the overexpression of circ_0004771 resulted in the opposite result as when circ_0004771 was knocked down. A low level of circ_0004771 in AMI activates the MAPK signaling pathway in cardiomyocytes as well as encourages intracellular oxidative stress and ER stress, thereby inhibiting cell proliferation and promoting apoptosis.

Ca(II) doped ß-In2S3 hierarchical structures for photocatalytic hydrogen generation and organic dye degradation under visible light irradiation.

Hierarchical structures assembled by two-dimensional (2D) nanosheets could inherit the characteristics of nanosheets and acquire additional advantages from the unique secondary architectures, which would have important influences on the photocatalytic properties of semiconductor nanomaterials. In this work, we successfully synthesized Ca(II) doped ß-In2S3 hierarchical structures stacked by thin nanosheets by a simple solution chemical process. The effects of reaction temperature and Ca2+ concentration on the size and morphology of the products were systematically investigated. The photocatalytic applications of the ß-In2S3 hierarchical structures were evaluated for hydrogen production and degradation of Rhodamine B (RhB) under visible light irradiation (λ>420nm). The ß-In2S3 hierarchical structures showed promising activity towards photocatalytic hydrogen production (145.0µmolg-1h-1) and RhB solution (1×10-5M) was completely degraded within 100min under visible light irradiation.

Monodisperse SnS2 nanosheets for high-performance photocatalytic hydrogen generation.

Graphene-like two-dimensional layered materials have attracted quite a lot of interest because of their sizable band gaps and potential applications. In this work, monodisperse tin disulfide (SnS2) nanosheets were successfully prepared by a simple solvothermal procedure in the presence of polyvinylpyrrolidone (PVP). Large PVP molecules absorbing on (001) facets of SnS2 would inhibit crystal growth along [001] orientation and protect the product from agglomeration. The obtained SnS2 nanosheets have diameters of ca. 0.8-1 µm and thicknesses of ca. 22 nm. Different experiment parameters were carried out to investigate the transformation of phase and morphology. The formation mechanism was proposed according to the time-dependent experiments. SnS2 nanosheets exhibit high photocatalytic H2 evolution activity of 1.06 mmol h(-1) g(-1) under simulated sunlight irradiation, much higher than that of SnS2 with different morphologies and P25-TiO2. Moreover, the as-obtained SnS2 nanosheets show excellent photoelectrochemical response performance in visible-light region.

Solvothermal synthesis of orthorhombic Sb2WO6 hierarchical structures and their visible-light-driven photocatalytic activity.

We report the solvothermal synthesis of hierarchical structures of orthorhombic Sb2WO6 and their implementation as a visible-light-driven photocatalyst for the degradation of Rhodamine B. The obtained hierarchical structures constructed by tiny nanosheets are doughnut-like flat ellipsoids with concaves in the centres, and with typical sizes of 1.3 µm in length, 800 nm in width and 400 nm in thickness. The concave characteristics and sizes of Sb2WO6 hierarchical structures can be tuned by adjusting the volume ratio of EG-H2O. Time-dependent experiments reveal that the formation process of concave structures involves the aggregation of nanoparticles to form solid spheres, dissolution-recrystallization to form hierarchical structures subsequently, and an Ostwald ripening process to shape the desired concaves finally. Under visible-light irradiation, complete degradation of Rhodamine B is achieved within 180 min in the presence of Sb2WO6 hierarchical structures, which could be ascribed to the porous structures, high BET surface area (42.58 m(2) g(-1)) and wide absorption in the visible-light region.