Improving the Corrosion Resistance of Zn-Rich Epoxy Coating with Three-Dimensional Porous Graphene.

To improve the corrosion inhibition of zinc-rich epoxy (ZRE) composite coatings and shed light on the influence of the spatial structure of graphene fillers on the coatings' performance, three-dimensional graphene (3DG) and a conventional graphene sheet (G) were used to modify the ZRE composite paint, respectively. The effect of introducing the 2D G fillers on the anti-corrosion behavior of ZRE was studied comprehensively, and its optimal content was determined to be 0.5 wt%. Interestingly, it was found that, comparing with 2D graphene sheets, the corrosion resistance of the ZRE coating could be enhanced more significantly with incorporating even less 3DG. With introducing only 0.1 wt% 3DG, the corrosion current intensity of the resulting 3DG/ZRE coating was reduced to be about 1/10 that of the G/ZRE coating with the same graphene content and 27% of that of the optimized G/ZRE. The corrosion products of the coating were analyzed with the XRD technique. The results indicated that, in contrast to neat ZRE coating, Zn5(CO3)2(OH)6 was absent from the corroded 3DG/ZRE coating, confirming its improved long-term anti-corrosion performance. The porous interconnected framework and high crystallinity of 3DG could contribute to not only its facilely mixing with epoxy resin, but also its effective incorporation into the conductive network of zinc micro-flakes, thus enhancing the corrosion resistance of its ZRE coating at a lower content. The innovative technology to improve the anti-corrosion performance of the ZRE coatings via using the 3D graphene fillers should be capable to be extended to other 2D fillers, such as MXenes.

LncRNA DLEU1 is overexpressed in premature ovarian failure and sponges miR-146b-5p to increase granulosa cell apoptosis.

BACKGROUND: miR-146b-5p has been reported to participate in premature ovarian failure (POF) in mice. However, its role in POF patients is unclear. We predicted that miR-146b-5p might interact with lncRNA DLEU1, a crucial player in ovarian cancer. We then explored the interaction between DLEU1 and miR-146b-5p. METHODS: Expression of DLEU1 and miR-146b-5p in POF and control ovary tissues was determined by RT-qPCR. The subcellular location of DLEU1 in human KGN cells was analyzed using subcellular fractionation assays. The direct interaction between DLEU1 and miR-146b-5p was analyzed using RNA pull-down assays. The role of DLEU1 in miR-146a expression was analyzed using overexpression assay. Cell proliferation was analyzed using cell apoptosis assay. RESULTS: Increased DLEU1 expression and decreased miR-146b-5p expression were observed in POF. DLEU1 directly interacted with MiR-146b-5p and was expressed in both nuclear and cytoplasm samples of KGN cells. In KGN cells, DLEU1 and miR-146b-5p failed to regulate the expression of each other. However, DLEU1 promoted cell apoptosis and reduced the inhibitory effects of miR-146b-5p on cell apoptosis. CONCLUSIONS: DLEU1 is overexpressed in POF and sponges miR-146b-5p to increase KGN cell apoptosis.

Molecular Model Construction of the Dense Medium Component Scaffold in Coal for Molecular Aggregate Simulation.

Coal as an important fossil energy has been comprehensively studied in terms of its structure, reactivity, and application. However, there are few publications reported about the formation mechanism of coal. In order to explore the molecular mechanism of the formation of the dense medium component (DMC) aggregate, which is extracted from coal, the molecular model of the DMC scaffold (DMC-S) was constructed based on a number of X-ray photoelectron spectroscopy, 13C NMR, and ultimate analysis. Then, DMC-S was further optimized, and the periodic boundary condition was added for molecular mechanics and molecular dynamics simulation. The DMC-S molecule model with a density of 1.05 g/cm3 and a different number of unit cells was obtained after the aforementioned experiments and simulations. When the unit cell contained 12 DMC-S molecules, the absolute value of electrostatic energy significantly increased and the peripheral branch chains in DMC-S interlaced with each other, forming a compact aggregate. The density and macrosize calculated values are all slightly lower than the true relative values because the presence of minerals or small molecules was not included in the model construction. Despite some unavoidable defects, the comparison between the simulated and experimental results validates the DMC-S aggregate model and lays a solid foundation for an in-depth study of DMC and its reactivity.

Chemical composition and antioxidant activity of phenolic compounds from Dioscorea (Yam) leaves.

This study was aimed to assess the potential of Dioscorea (yam) leaves as a source of antioxidants. Microwave-assisted extraction (MAE) process was used to prepare the extracts. The phenolic compounds in Dioscorea leaves extracts were analyzed by HPLC-DAD-ESI-MS/MS method and the contents of major compounds were determined. Results indicated that a total of 17 phenolic compounds were separated identified by means of UV and mass spectra compared with authentic reference substances and/or reported values in the literature. The main phenolic compound was rosmarinic acid and its highest amount was found in Dioscorea glabra Roxb. leaves (22.31±1.33 mg/g DW). Rutin was the dominant flavonoid followed by quercetin which highest amount was found in Dioscorea alata leaves (8.66±0.29 mg/g DW). Antioxidant activity of the extracts was estimated by the use of DPPH and ABTS assays. Both kinds of leaves exhibited satisfied antioxidant capacity which was correlated with phenolic contents. In the cytoprotective effect on HUVECs viability assay, Dioscorea glabra Roxb. leaves extract was found to be more active than that of Dioscorea alata against H2O2-induced oxidative stress. Our findings support the promising role of Dioscorea leaves that can be used as an interesting source of phenolic antioxidants.

Aggregation-induced emission on benzothiadiazole dyads with large third-order optical nonlinearity.

Two kinds of D-A molecular of (4-(4-(9H-carbazol-9-yl)phenyl))-7-nitrobenzothiadiazole (BSC) and 4-((4-(9H-carbazol-9-yl)phenyl)ethynyl)-7-nitrobenzothiadiazole (BEC) containing carbazole moieties as the donor were synthesized. X-ray crystal data elucidated the multiple intermolecular interactions. They exhibit distinctly different self-assembly behaviours. The nonlinear optical properties were studied using the top-hat Z-scan technique at 532 nm with a 21 ps pulse. The results indicate that they exhibit large third-order nonlinear absorption effects. The nonlinear absorption coefficients α2 fitting the experimental data are 6.3 × 10(-12) m W(-1) for BSC and 3.6 × 10(-11) m W(-1) for BEC. The time-resolved pump-probe results show that both nonlinear absorption and nonlinear refraction of BEC in CH2Cl2 solution have rapid optical responses, which indicate the nonlinear absorption and nonlinear refraction mechanism are excited-state nonlinear. Moreover, both of these two compounds are observed to be aggregation-induced emission (AIE) active. The aggregates of the well-formed one-dimensional microrods of BEC and BSC endow the material with potential applications in the field of optical devices.

Designed synthesis and supramolecular architectures of furan-substituted perylene diimide.

Novel furan-substituted perylene diimides are successfully synthesized and an efficient supramolecular architecture approach to construct zero/one-dimensional nano- and micro-structures by controlling solvents has been demonstrated. The aggregate structure conversion in different molecular structures can be controlled in the form of sphere-like, rod-like, and vesicle-like structures. As expected, these solid supramolecular rod-like architectures displayed interesting optical waveguide behavior, which indicates the aggregate structure materials of furan-substituted perylene diimides have the potential application as micro-scale photonic elements.

Selective and colorimetric fluoride anion chemosensor based on s-tetrazines.

s-Tetrazine and their derivatives are found to be a class of selective and colorimetric chemosensors for fluoride anions. The supramolecular interaction (anion-π and charge/electron transfer) between fluoride ion and π-electron deficient tetrazines receptor could facilitate the F(-)-tetrazines electron transfer (ET) event that generates tetrazine˙(-) radical anion. Accordingly, the color of its solution changed from red to green. Furthermore, the recognition of F(-) in DMSO is tolerant to water (DMSO-H(2)O = 9:1, v/v) and shows excellent selectivity towards other anions, especially H(2)PO(4)(-) and OAc(-).

Effect of rosiglitazone on the expression of cardiac adiponectin receptors and NADPH oxidase in type 2 diabetic rats.

This study investigated the effect of rosiglitazone on the expression of cardiac adiponectin receptors and NADPH oxidase in type 2 diabetic rats. Thirty-six male Wistar rats were randomly divided into control (C, n=10), diabetic (D, n=13) and diabetic treated with rosiglitazone (DT, n=13). Type 2 diabetes was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin (STZ). Eleven rats in diabetic untreated group and twelve rats in diabetic treated group were successfully induced to be diabetes. After induction of diabetes, rosiglitazone (3mg/kg/day) was administrated to diabetic treated rats by gavage for 12 weeks. Twelve weeks later, the heart function was detected. Plasma and myocardial adiponectin levels were detected by enzyme linked immunosorbent assay (ELISA). The cardiac mRNA expression of adiponectin receptors 1 and 2, and monocyte chemoattractant protein-1 (MCP-1) was assayed by reverse transcript-polymerase chain reaction (RT-PCR). The cardiac mRNA expression of p22phox and NOX4 was assayed by real-time fluorescence quantitative PCR. The cardiac protein expression of phosphor-AMPK-α (Thr172) and glucose transporter 4 (GLUT4) was determined by Western blotting. The protein expression of adiponectin receptors 1 and 2, and connective tissue growth factor (CTGF)were determined by immunohistochemistrial staining. The ratio of heart weight to body weight was significantly increased in diabetic rats compared to control. Heart function, plasma and myocardial adiponectin levels, the protein and mRNA expression of myocardial adiponectin receptors 1 and 2, myocardial phosphorylation of AMPK-α (Thr172) and the protein expression of myocardial GLUT4 were significantly decreased in diabetic rats compared to control (P<0.05). The expression of myocardial p22phox, Nox4, MCP-1 and CTGF was significantly increased in diabetic rats compared to control (P<0.05). Rosiglitazone treatment significantly attenuated the increased ratio of heart weight to body weight, and the increased expression of myocardial p22phox, Nox4, MCP-1 and CTGF in diabetic rats (P<0.05). Heart function, plasma and myocardial adiponectin levels, the expression of myocardial adiponectin receptors 1 and 2 and GLUT4, and myocardial phosphorylation of AMPK-α (Thr172) were significantly decreased in diabetic treated with rosiglitazone compared to diabetic untreated (P<0.05). These results suggest that the protective effects of rosiglitazone on diabetic rat hearts may be attributable to the increased myocardial adiponectin and its receptors and the decreased myocardial NADPH oxidase.

Ganoderma applanatum terpenes protect mouse liver against benzo(α)pyren-induced oxidative stress and inflammation.

Ganoderma applanatum terpenes (GAT) have been reported to have many benefits and medicinal properties. In this study, we evaluated the protective effect of GAT against benzo(a)pyrene (BaP) induced oxidative stress and inflammation in mouse liver, and explored the potential mechanism of its action. Our data showed that GAT significantly decreased levels of ALT and AST in serum and the liver histological injury in BaP-treated mice. GAT markedly decreased the levels of ROS, MDA and lowered the GSH/GSSG ratio in the liver of BaP-treated mice. Furthermore, GAT markedly inhibited the BaP-induced increase of Cu/Zn-SOD, CAT, GPx and GST activities in the mouse liver. Western blot analysis showed that GAT significantly inhibited inflammation by pressing the expression of IL-1ß and COX-2 and inhibiting NF-κB translocation in the liver of BaP-treated mice. In conclusion, these results suggested that GAT could protect the mouse liver against BaP-induced injury by improving hepatic function, attenuating histopathologic changes, decreasing levels of ROS and MDA, renewing the activities of antioxidant enzymes and suppressing inflammatory response.

Cellular and molecular mechanisms of the Ganoderma applanatum extracts induces apoptosis on SGC-7901 gastric cancer cells.

To investigate the inhibition effect of Ganoderma applanatum extract (GAEAE) on human gastric cancer cell lines and apoptosis mechanism, Alamar Blue assay was used to assess the inhibition and apoptosis-inducing effect of the GAEAE on proliferation of SGC-7901 cells, the DNA ladders of the apoptosis cells was done, the mRNA expression of p53, Bax, Bcl-2 and JNK were analysed by reverse transcription-polymerase chain reaction. The levels of the Cyt C and the p53, Bax/Bcl-2, JNK proteins and the caspase-3 activity in the SGC-7901 cells were measured with ELISA kits. Our data showed that the GAEAE markedly inhibited the proliferation of SGC-7901 cells in a dose-dependent manner. The expression of Bcl-2 protein was down-regulated and Bax, c-jun, p53 protein expressions were up-regulated by the GAEAE treatment in SGC-7901 cells. The activity of caspase-3 was markedly increased and the Cty C was markedly released into cytoplasm from the mitochondria after GAEAE action. In conclusion, our results indicated that the GAEAE could enhance the sensitivity of SGC-7901 cells to the c-jun, p53, Bax and Bcl-2 induced apoptosis and provided a promising approach to anti-human gastric cancer therapy with Ganoderma applanatum.

Effect of telmisartan on the expression of cardiac adiponectin and its receptor 1 in type 2 diabetic rats.

OBJECTIVES: This study investigated the effect of telmisartan on the expression of cardiac adiponectin and its receptor 1 in type 2 diabetic rats. METHODS: Thirty-six male Wistar rats were randomly divided into control (C, n = 10) and diabetic (n = 26) groups. Type 2 diabetes was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin (STZ). After induction of diabetes, diabetic rats were again randomly divided into diabetic (D, n = 10) and diabetic treated (DT, n = 10) groups. Telmisartan (5 mg/kg/day) was administrated to diabetic treated rats by gavage for 12 weeks. Twelve weeks later, the heart function was investigated. Plasma and myocardial adiponectin levels were detected by enzyme-linked immunosorbent assay (ELISA). The cardiac mRNA expression of adiponectin receptor 1 (adipiR1) was assayed by reverse transcript-polymerase chain reaction (RT-PCR). The cardiac protein expression of adipiR1, AMP-activated protein kinase (AMPK)-α, phospho-AMPK-α (Thr172) and glucose transporter 4(GLUT4) was determined by Western blotting. KEY FINDINGS: The ratio of heart weight to body weight was significantly increased in diabetic rats compared with control. The decreased levels of plasma and myocardial adiponectin and the decreased protein and mRNA expression of myocardial adipoR1 led to the decreased myocardial phosphorylation of AMPK-α (Thr172) and the decreased protein expression of myocardial GLUT4 in diabetic rats. Consequently, the heart function was decreased in diabetic rats. Telmisartan treatment significantly attenuated the increased ratio of heart weight to body weight in diabetic rats. The levels of plasma and myocardial adiponectin and the expression of myocardial adipoR1 in diabetic rats were upregulated by telmisartan. Subsequently, the levels of myocardial phospho-AMPK-α (Thr172) and the expression of myocardial GLUT4 in diabetic rats were increased by telmisartan. Consequently, the heart function was improved in diabetic rats treated with telmisartan. CONCLUSIONS: These results suggest that the levels of myocardial adiponectin and its receptor 1 are decreased in type 2 diabetic rats. Telmisartan treatment up-regulates the levels of myocardial adiponectin and its receptor 1, resulting in the increase in myocardial phospho-AMPK-α (Thr172) and GLUT4 expression, which may contribute to the improvement of heart function and the decrease in cardiac hypertrophy in diabetic rats.

[Preparation and preliminary identification of the monoclonal antibody to bovine bFGF].

AIM: To prepare mAb against bovine bFGF and identify their Ig subgroups so as to establish an ELISA for detection of bFGF level. METHODS: BALB/c mice were immunized by recombinant bovine bFGF. Hybridoma cell lines which could stably secret the monoclonal antibodies to bFGF were established by cell fusion technique, and their related characteristics were identified. In addition, polyclonal antibodies to bFGF were prepared by immunization of rabbits with bovine bFGF. The mAb and polyclonal antibodies purified through protein A affinity chromatography were used to develop a sandwich ELISA for detection of bFGF level. RESULTS: Three hybridoma cell lines which could secret the mAbs IgG 1 to bFGF were obtained. The concentration of bFGF could be detected by sandwich ELISA developed with purified mAb and polyclonal antibody at nanogram level. CONCLUSION: mAb and polyclonal antibodies against to bovine bFGF have been prepared successfully, which provide powerful tool for further clinical application and related studies.