Synthesis, characterization and photocatalytic properties of In2.77S4/Ti3C2 composites.

Recently, the problem of water pollution, caused by antibiotics, is becoming more and more serious. Photocatalysis is one of the promising technologies for removing antibiotics from water. Herein, the In2.77S4/Ti3C2 composites were prepared by an in-situ hydrothermal growth method for photocatalytic degradation of tetracycline (TC). The as-developed composites were characterized by various methods. The UV-Vis DRS spectra reveals that the introduction of Ti3C2 makes the bandgap of the as-prepared composites smaller and the visible light absorption ability improved. The photocatalytic degradation efficiency of the as-prepared composite is enhanced under visible light illumination. It is shown as first increasing and then decreasing with increasing the content of Ti3C2 in the composite and reaches to the maximum of 89.3% in 90 min, which is higher than 75.1% of In2.77S4 and 6.7% of Ti3C2. The reason of improvement is the interface between In2.77S4 and Ti3C2 is tightly combined to form a heterojunction. Moreover, the photocurrent intensity of the as-obtained composite is improved, while its Nyquist arc radius is decreased. In addition, holes are the main active species and ·OH and ·O2 - play an auxiliary role during the degradation of TC.

AgBrO3/Few-Layer g-C3N4 Composites: A Visible-Light-Driven Photocatalyst for Tetracycline Degradation.

The AgBrO3/few-layer g-C3N4 composite photocatalyst has been developed via an in-situ synthetic method. The structure, morphology, light response range, separation and migration efficiency of the photogenerated electron-hole pairs and element valence state of the as-obtained samples have been characterized. The tetracycline was used to discuss the photocatalytic activities of the samples. The photocatalytic degradation mechanism of the as-obtained composites was also researched. The analysis results show that the photocatalytic degradation property of the asobtained composite photocatalyst appears to the tendency of first increasing and then decreasing with increasing the amount of AgBrO3 under visible light illumination. When the mass ratio of AgBrO3 to g-C3N4 is 4:3, in 60 min, the photocatalytic degradation efficiency of the as-obtained composites reaches the maximum of 79%. It is 37% and 45% higher than that of pure AgBrO3 and g-C3N4, respectively. Moreover, the separation and migration efficiency of the photogenerated electron-hole pairs of the as-prepared composites are also enhanced. In addition, superoxide radicals and holes are the dominant active species during the photocatalytic degradation process.

Preparation and Characterization of Nanosized Bi-Doped SnO2/Reduced Graphene Oxide 3D Hybrids for Visible-Light-Driven Photocatalysis.

The nanosized Bi-doped SnO2/reduced graphene oxide 3D hybrids have been synthesized via one-step hydrothermal method. The structures, morphologies, photocatalytic activities of the as-prepared samples were discussed, respectively. The formation mechanism of the as-prepared hybrids was also proposed. Experimental results indicated that the usage amount of Bi2Sn2O7 obviously affected the photocatalytic performance of the as-prepared products. When it was 450 mg, the as-prepared sample possessed the band gap energy of 1.9 eV and the photocatalytic efficiency of 90% in 210 min for degradation of rhodamine B solution. In addition, triethylene tetramine and the as-prepared carbon hydrogel could act as reductant to synergistically reduce Bi2Sn2O7 into Bi-doped SnO2 particles during the formation of the hybrids.

Zn2SnO4-Reduced Graphene Oxide Nanohybrids for Visible-Light-Driven Photocatalysis.

Zn2SnO4-reduced graphene oxide photocatalysts were synthesized by using SnCl4 5H2O, Zn(NO3)2 · 6H2O and graphene oxide via hydrothermal process. The structure, morphology, specific surface area and photo response of the as-prepared nanocomposites were characterized by X-ray diffraction, Transmission electron microscopy, UV-vis diffuse reflectance spectra, Brunauer-emmett-teller surface area measurement and Photoluminescence emission spectra. Experimental results showed that the Zn2SnO4 nanoparticles, with 20-30 nm a size range, were uniformly dispersed on the surfaces of reduced graphene oxide. Moreover, the as-prepared Zn2SnO4-reduced graphene oxide photocatalysts exhibited enhanced photocatalytic activities for degradation of Rhodamine B compared to those of pure Zn2SnO4. When the amount of reduced graphene oxide was 4 wt%, it showed the highest photocatalytic efficiency of 99.7% for 240 min, and the photocatalytic efficiency was still 98.5% after it was recycled 4 times. It also possessed the band gap of 2.48 eV and specific surface area of 58.1 m2 g-1.

Solvothermal Preparation of Zinc Oxide/Reduced Graphene Oxide Composites for Rapid Removal of Methylene Blue.

Zinc oxide/reduced graphene oxide composites with various morphologies and properties were prepared via a one-step solvothermal process. The formation of zinc oxide and reduction of graphene oxide were simultaneously accomplished. These as-obtained samples showed high performance in removing methylene blue from aqueous solution. Solvent could play an important role in tuning the morphologies of the zinc oxide and the efficiency of the final composites. Composites prepared in acetone showed the highest removal efficiency, compared with those prepared in water and ethanol. Loading content of the reduced graphene oxide could affect the performance as well. With the increase in the content of the reduced graphene oxide, the as-prepared samples showed enhanced performance gradually. The as-prepared composite showed certain stability, with a maximum recyclability of 5 times for efficient removal. The effective removal of target dye turned out to be the result of the combination of physical adsorption and photo-catalysis.

Preparation of Reduced-Graphene Nanoribbons via One-Step Solvothermal Process.

Carbon nanotubes were unzipped to become reduced-graphene nanoribbons via one-step solvothermal process in a Teflon-lined autoclave. The samples were characterized by X-ray diffraction, thermo-gravimetric analysis and transmission electrical microscopy, respectively. Results showed that the solvothermal reaction temperature played an important role in the structure of the samples. When it was 75 °C, carbon nanotubes were completely cutted into graphene oxide nanoribbons. Moreover, when it was 155 °C, they were become reduced-graphene nanoribbons. Furthermore, the as-prepared reduced-graphene nanoribbons could improve mechanical strength of the phenolic resin/hollow glass beads foamed composites. When the reduced-graphene nanoribbons loading was 0.4 wt%, the tensile and compressive strength of the composites were increased by 19.7% and 21.3%, respectively.

[Effect of chronic psychological stress on vascular endothelial dysfunction rats and intervention tongxinluo on it].

OBJECTIVE: To observe the effect of chronic psychological stress on vascular endothelial dysfunction rats and to explore the intervention and mechanism of Tongxinluo (TXL) on it. METHODS: Forty male Wistar rats were randomly divided into the normal control group (with no modeling), the endothelial dysfunction group (the HCY group), the psychological stress group (the model group), and TXL group, ten in each group. Rats in the latter three groups were fed with 3% high methionine diet to duplicate vascular endothelial dysfunction (VED) model. In addition, chronic psychological stress was applied in VED rats using repeated binding method. TXL at the dose of 1.2 g/kg body weight was given by gastrogavage. The plasma endothelin (ET) and angiotensin II (Ang II), serum cortisone (CORT) were detected by radioimmunoassay. The serum nitric oxide (NO) was detected by nitrate reductase. Ultrastructural changes of aortic endothelial cells were observed by transmission electron microscope. Serum levels of norepinephrine (NE) and epinephrine (E) were detected by enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with the plasma ET level and the serum NO level in the HCY group (161.70 +/- 13.96 pg/mL and 26.82 +/- 13.03 micromol/L), the plasma ET level obviously increased (178.25 +/- 21.85 pg/mL) (P < 0.05) and the serum NO level decreased (24.91 +/- 9.95 micromol/L, P > 0.05), levels of CORT, NE, and E obviously increased in the model group (all P < 0.05). Ultrastructural changes of aortic endothelial cells were obviously injured. Compared with the model group, the plasma ET level (154.74 +/- 13.27 pg/mL), Ang II, CORT, NE, and E obviously decreased (P < 0.05, P < 0.01), the serum NO level obviously increased (34.44 +/- 18.35 micromol/L, P < 0.05). Ultrastructural changes of aortic endothelial cells were obviously improved. CONCLUSIONS: Chronic psychological stress could obviously aggravate endothelial injury in VED rats. TXL showed protection on the vascular endothelial structure and function.

[Effects of Tongxinluo on neuron ultrastructure and endothelial cell self-repairing ability in hypoxia preconditioning mice].

OBJECTIVE: To observe the ultrastructure changes of cerebral cortex neuron and endothelial cell in hypoxia preconditioning mice and the effects of Tongxinluo (TXL, Chinese traditional medilihe) on them. METHODS: Mice were randomly divided into 4 groups: control group, hypoxia group, hypoxia preconditioning (HP) group and Tongxinluo (TXL) group. The hypoxia preconditioning mice were exposed by repetitive hypoxia for 5 runs. The animal's tolerance time of each hypoxia run was recorded. The ultrastructure change of cerebral neuron and endothelial cell were studied by electron microscope. RESULTS: The hypoxic tolerance time in HP and TXL groups were significantly increased run by run. Compared with HP group, the tolerance time of TXL group were increased in every run. The ultrastructure of cerebral neuron and endothelial cell in hypoxia group changed obviously, mitochondrion and endoplasmic reticulum destroyed. However they were slighter in HP group than those in hypoxia group. The change in TXL group had no obvious differentce with control group and were slighter than those in HP group. CONCLUSION: Hypoxia preconditioning shows that organism has a strong self-repairing ability. Tongxinluo self-repairing; could increase self-repairing ability and adaptive ability of mice to hypoxia obviously.

[Effects of Tongxinluo on repeated hypoxic tolerance in mice].

OBJECTIVE: To observe the effects of Tongxinluo (TXL) on repeated hypoxic tolerance in mice and explore the underlying mechanisms. METHODS: Mice were randomly divided into groups of repeated hypoxia (control) and TXL according to body weights. The mice in each group were exposed to acute repeated hypoxia for 0 run (H0), 1 run (H1), 3 runs (H3) and 5 runs (H5). The animal's tolerance time of each hypoxic exposure was recorded. Western blot was used to measure the protein levels of hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in cortex tissue. RESULTS: The hypoxic tolerance time in control and TXL groups significantly increased run by run. Both HIF-1alpha and VEGF proteins in two groups increased gradually. Compared with control group, the tolerance time in H1 of TXL group [(18.0 +/- 2.4) minvs (15.6 +/- 2.0) min], H3 [(68.3 +/- 13.2) min vs (41.7 +/- 9.0) min) and H5 (85.9 +/- 7.0) min vs (51.4 +/- 14.4) min] increased (P < 0.05 or P < 0.01); the HIF-1alpha protein expression in H1 of TXL group (0.95 +/- 0.04 vs 0.79 +/- 0.02), H3 (1.01 +/- 0.03 vs 0.85 +/- 0.02), H5 (1.16 +/- 0.02 vs 0.92 +/- 0.03) increased (P < 0.05 or P < 0.01); the VEGF protein expression in H3 of TXL group (1.14 +/- 0.02 vs 0.89 +/- 0.03), H5 (1.34 +/- 0.05 vs 0.99 +/- 0.07) increased (P < 0.05 or P < 0.01). CONCLUSIONS: Under repeated hypoxia, an organism has a strong adaptive ability. The rises of HIF-1alpha and VEGF may be an adaptive mechanism. TXL can increase obviously the adaptive ability of mice to hypoxia.

[Remote postconditioning by brief renal ischemia and reperfusion reduces acute myocardial ischemia and reperfusion induced myocardial apoptosis in rabbits].

OBJECTIVES: To observe the effects of renal ischemic postconditioning (RI-Post) on myocardial apoptosis in rabbits with acute myocardial ischemia and reperfusion. METHODS: All rabbits were subjected to 60 minutes ischemia by left anterior descending coronary artery occlusion (LADO) and 6 hours reperfusion. The rabbits are randomly divided into 3 groups (n = 8 in each group): (1) Ischemia-reperfusion (IR): LADO and reperfusion without additional intervention; (2) RI-Post: after 60 minutes of LADO, the left renal artery was occluded for 30 seconds and reperfused for 30 seconds and repeated 3 times, then the coronary artery was reperfused for 6 hours; (3) Medication intervention (MI): 10 minutes before coronary reperfusion, rabbits were treated with PKC antagonist GF109203X (0.05 mg/kg, IV), followed by RI-Post treatment and 6 hours coronary reperfusion. Myocardial apoptosis was measured by TUNEL and the myocardial Bcl-2 and Bax protein expressions were assessed by immunohistochemistry. RESULTS: Compared with the IR group and the MI group, myocardial apoptosis was significantly reduced (P < 0.05) and the Bcl-2 protein expression increased (P < 0.01) while the Bax protein expression decreased (P < 0.05) in the RI-Post group. CONCLUSIONS: Remote renal postconditioning applied right before the onset of coronary artery reperfusion can reduce the myocardial apoptosis induced by myocardial ischemia and reperfusion and up-regulate Bcl-2 while down-regulate Bax expression possibly by activation of protein kinase C.

Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes.

BACKGROUND: Shensong Yangxin (SSYX) is one of the compound recipe of Chinese materia medica. This study was conducted to investigate the effects of SSYX on sodium current (I(Na)), L-type calcium current (I(Ca, L)), transient outward potassium current (I(to)), delayed rectifier current (I(K)), and inward rectifier potassium currents (I(K1)) in isolated ventricular myocytes. METHODS: Whole cell patch-clamp technique was used to study ion channel currents in enzymatically isolated guinea pig or rat ventricular myocytes. RESULTS: SSYX decreased peak I(Na) by (44.84 +/- 7.65)% from 27.21 +/- 5.35 to 14.88 +/- 2.75 pA/pF (n = 5, P < 0.05). The medicine significantly inhibited the I(Ca, L). At concentrations of 0.25, 0.50, and 1.00 g/100 ml, the peak I(Ca, L) was reduced by (19.22 +/- 1.10)%, (44.82 +/- 6.50)% and (50.69 +/- 5.64)%, respectively (n = 5, all P < 0.05). SSYX lifted the I - V curve of both I(Na) and I(Ca, L) without changing the threshold, peak and reversal potentials. At the concentration of 0.5%, the drug blocked the transient component of I(to) by 50.60% at membrane voltage of 60 mV and negatively shifted the inactive curve and delayed the recovery from channel inactivation. The tail current density of I(K) was decreased by (30.77 +/- 1.11)% (n = 5, P < 0.05) at membrane voltage of 50 mV after exposure to the medicine and the time-dependent activity of I(K) was also inhibited. Similar to the effect on I(K), the SSYX inhibited I(K1) by 33.10% at the test potential of -100 mV with little effect on reversal potential and the rectification property. CONCLUSIONS: The experiments revealed that SSYX could block multiple ion channels such as I(Na) I(Ca, L), I(k), I(to) and I(K1), which may change the action potential duration and contribute to some of its antiarrhythmic effects.