Microbial Photoelectrotrophic Denitrification as a Sustainable and Efficient Way for Reducing Nitrate to Nitrogen.

Biological removal of nitrate, a highly concerning contaminant, is limited when the aqueous environment lacks bioavailable electron donors. In this study, we demonstrated, for the first time, that bacteria can directly use the electrons originated from the photoelectrochemical process to carry out the denitrification. In such photoelectrotrophic denitrification (PEDeN) systems (denitrification biocathode coupling with TiO2 photoanode), nitrogen removal was verified solely relying on the illumination dosing without consuming additional chemical reductant or electric power. Under the UV illumination (30 mW·cm-2, wavelength at 380 ± 20 nm), nitrate reduction in PEDeN apparently followed the first-order kinetics with a constant of 0.13 ± 0.023 h-1. Nitrate was found to be almost completely converted to nitrogen gas at the end of batch test. Compared to the electrotrophic denitrification systems driven by organics (OEDeN, biocathode/acetate consuming bioanode) or electricity (EEDeN, biocathode/abiotic anode), the denitrification rate in PEDeN equaled that in OEDeN with a COD/N ratio of 9.0 or that in EEDeN with an applied voltage at 2.0 V. This study provides a sustainable technical approach for eliminating nitrate from water. PEDeN as a novel microbial metabolism may shed further light onto the role of sunlight played in the nitrogen cycling in certain semiconductive and conductive minerals-enriched aqueous environment.

Molecular cloning, sequence characteristics, and tissue expression analysis of ECE1 gene in Tibetan pig.

Low air pressure and low oxygen partial pressure at high altitude seriously affect the survival and development of human beings and animals. ECE1 is a recently discovered gene that is involved in anti-hypoxia, but the full-length cDNA sequence has not been obtained. For a better understanding of the structure and function of the ECE1 gene and to study its effect in Tibetan pig, the cDNA of the ECE1 gene from the muscle of Tibetan pig was cloned, sequenced and characterized. The ECE1 full-length cDNA sequence consists of 2262 bp coding sequence (CDS) that encodes 753 amino acids with a molecular mass of 85,449 kD, 2 bp 5'UTR and 1507 bp 3'UTR. In addition, the phylogenetic tree analysis revealed that the Tibetan pig ECE1 has a closer genetic relationship and evolution distance with the land mammals ECE1. Furthermore, analysis by qPCR showed that the ECE1 transcript is constitutively expressed in the 10 tissues tested: the liver, subcutaneous fat, kidney, muscle, stomach, heart, brain, spleen, pancreas, and lung. These results serve as a foundation for further insight into the Tibetan pig ECE1 gene.

In situ growth of matchlike ZnO/Au plasmonic heterostructure for enhanced photoelectrochemical water splitting.

In this paper, we report a novel matchlike zinc oxide (ZnO)/gold (Au) heterostructure with plasmonic-enhanced photoelectrochemical (PEC) activity for solar hydrogen production. The matchlike heterostructure with Au nanoparticles coated on the tip of ZnO nanorods is in situ grown on a zinc (Zn) substrate by using a facile hydrothermal and photoreduction combined approach. This unique heterostructure exhibits plasmonic-enhanced light absorption, efficient charge separation and transportation properties with tunable Au contents. The photocurrent density of the matchlike ZnO/Au heterostructure reaches 9.11 mA/cm(2) at an applied potential of 1.0 V (vs Ag/AgCl) with an Au/Zn atomic ratio of 0.039, which is much higher than that of the pristine ZnO nanorod array (0.33 mA/cm(2)). Moreover, the solar-to-hydrogen conversion efficiency of this special heterostructure can reach 0.48%, 16 times higher than that of the pristine ZnO nanorod array (0.03%). What is more, the efficiency could be further improved by optimizing the Au content of the heterostructure. The formation mechanism of such a unique heterostructure is proposed to explain the plasmonic-enhanced PEC performance. This study might contribute to the rational design of the visible-light-responsive plasmonic semiconductor/metal heterostructure photoanode to harvest the solar spectrum.

The MAP30 protein from bitter gourd (Momordica charantia) seeds promotes apoptosis in liver cancer cells in vitro and in vivo.

Human hepatocellular carcinoma Hep G2 cells and Hep G2-bearing mice were used as in vitro and in vivo models to assess the efficacy and safety of MAP30, a natural component from Momordica charantia, as an anticancer agent against liver cancer. Molecular studies disclosed the contribution of both caspase-8 regulated extrinsic and caspase-9 regulated intrinsic caspase cascades in MAP30-induced cell apoptosis. The antitumor potential was also effective in Hep G2-bearing nude mice. Since bitter gourd is a staple in many Asian countries, MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer.