Role of hydrophytes in constructed wetlands for nitrogen removal and greenhouse gases reduction.

With the prominence of global climate change and proposal of carbon reduction concept, how to maximize the comprehensive effect of nitrogen removal and greenhouse gases (GHGs) reduction in constructed wetlands (CWs) has become crucial. As indispensable biological component of CWs, hydrophytes have received extensive attention owing to their application potential. This review comprehensively evaluates the functions of hydrophytes in nitrogen removal and GHGs reduction in CWs in terms of plants themselves, plant-mediated microbes and plant residues (hydrophyte carbon sources and hydrophyte-derived biochars). On this basis, the strategies for constructing an ideal CW system are put forward from the perspective of full life-cycle utilization of hydrophytes. Finally, considering the variability of plant species composition in CWs, outlooks for future research are specifically proposed. This review provides guidance and novel perspectives for the full life-cycle utilization of hydrophytes in CWs, as well as for the construction of an ideal CW system.

Tumor mutation burden associated with miRNA-gene interaction outcome mediates the survival of patients with liver hepatocellular carcinoma.

Tumor mutation burden (TMB) is associated with immunogenic responses and the survival of cancer patients. This study demonstrates how TMB levels impact the immune-related cells, genes, and miRNAs, and how miRNA/gene interactions respond to variations in the survival rate of patients with liver hepatocellular carcinoma (LIHC). LIHC patients were divided into two groups, either a low TMB (< median) or a high TMB (≥ median) group. We found that high TMB plays a positive role in immune-mediated infiltration, generating more CD4 T-cells and memory B cells. Among the 21 immune genes that altered significantly, only C9orf24 and CYP1A1 were expected to up-regulate in LIHC patients with high TMB. A total of 19 miRNAs, which regulate various functional pathways, were significantly altered in patients with LIHC. One of the miRNA/gene pair, hsa-miR-33a/ALDH1A3 was significantly associated with the survival rate of LIHC patients. Our results suggest that LIHC patients with high TMB can be treated more effectively with immunotherapy.

Hydrothermal synthesis of a 3D double-sided comb-like ZnO nanostructure and its growth mechanism analysis.

Self-assembly of two-dimensional (2D) nanosheets and one-dimensional (1D) nanorods into three-dimensional (3D) double-sided comb-like ZnO nanostructures has been successfully performed via a simple one-step hydrothermal method on Si and ITO substrates. It is found that the thickness of the ZnO seeds plays a vital role in the formation of 3D double-sided comb-like ZnO.

Ultralong Rutile TiO2 Nanowire Arrays for Highly Efficient Dye-Sensitized Solar Cells.

Vertically aligned rutile TiO2 nanowire arrays (NWAs) with lengths of ∼44 µm have been successfully synthesized on transparent, conductive fluorine-doped tin oxide (FTO) glass by a facile one-step solvothermal method. The length and wire-to-wire distance of NWAs can be controlled by adjusting the ethanol content in the reaction solution. By employing optimized rutile TiO2 NWAs for dye-sensitized solar cells (DSCs), a remarkable power conversion efficiency (PCE) of 8.9% is achieved. Moreover, in combination with a light-scattering layer, the performance of a rutile TiO2 NWAs based DSC can be further enhanced, reaching an impressive PCE of 9.6%, which is the highest efficiency for rutile TiO2 NWA based DSCs so far.

Reaction mechanism of a PbS-on-ZnO heterostructure and enhanced photovoltaic diode performance with an interface-modulated heterojunction energy band structure.

A room temperature successive ionic layer adsorption and reaction (SILAR) method is introduced for fabricating quantum dots-on-wide bandgap semiconductors. Detailed exploration of how SILAR begins and proceeds is performed by analyzing changes in the electronic structure of related elements at interfaces by X-ray photoelectric spectroscopy, together with characterization of optical properties and X-ray diffraction. The distribution of PbS QDs on ZnO, which is critical for optoelectrical applications of PbS with a large dielectric constant, shows a close relationship with the dipping order. A successively deposited PbS QDs layer is obtained when the sample is first immersed in Na2S solution. This is reasonable because the initial formation of different chemical bonds on ZnO nanorods is closely related to dangling bonds and defect states on surfaces. Most importantly, dipping order also affects their optoelectrical characteristics greatly, which can be explained by the heterojunction energy band structure related to the interface. The formation mechanism for PbS QDs on ZnO is confirmed by the fact that the photovoltaic diode device performance is closely related to the dipping order. Our atomic-scale understanding emphasises the fundamental role of surface chemistry in the structure and tuning of optoelectrical properties, and consequently in devices.

Emodin enhances the demethylation by 5-Aza-CdR of pancreatic cancer cell tumor-suppressor genes P16, RASSF1A and ppENK.

5-Aza-2'-deoxycytidine (5-Aza-CdR) is currently acknowledged as a demethylation drug, and causes a certain degree of demethylation in a variety of cancer cells, including pancreatic cancer cells. Emodin, a traditional Chinese medicine (TCM), is an effective monomer extracted from rhubarb and has been reported to exhibit antitumor activity in different manners in pancreatic cancer. In the present study, we examined whether emodin caused demethylation and increased the demethylation of three tumor-suppressor genes P16, RASSF1A and ppENK with a high degree of methylation in pancreatic cancer when combined with 5-Aza-CdR. Our research showed that emodin inhibited the growth of pancreatic cancer Panc-1 cells in a dose- and time-dependent manner. Dot-blot results showed that emodin combined with 5-Aza-CdR significantly suppressed the expression of genome 5mC in PANC-1 cells. In order to verify the effect of methylation, methylation-specific PCR (MSP) and bisulfite genomic sequencing PCR (BSP) combined with TA were selected for the cloning and sequencing. Results of MSP and BSP confirmed that emodin caused faint demethylation, and 5-Aza-CdR had a certain degree of demethylation. When emodin was combined with 5-Aza-CdR, the demethylation was more significant. At the same time, fluorescent quantitative PCR and western blot analysis results confirmed that when emodin was combined with 5-Aza-CdR, the expression levels of P16, RASSF1A and ppENK were increased more significantly compared to either treatment alone. In contrast, the expression levels of DNA methyltransferase 1 (DNMT1) and DNMT3a were more significantly reduced with the combination treatment than the control or either agent alone, further proving that emodin in combination with 5-Aza-CdR enhanced the demethylation effect of 5-Aza-CdR by reducing the expression of methyltransferases. In conclusion, the present study confirmed that emodin in combination with 5-Aza-CdR enhanced the demethylation by 5-Aza-CdR of tumor-suppressor genes p16, RASSF1A and ppENK by reducing the expression of methyltransferases DNMT1 and DNMT3a.

Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells.

Emodin, a natural anthraquinone derivative isolated from Rheum palmatum, has been reported to inhibit the growth of pancreatic cancer cells through different modes of action; yet, the detailed mechanism remains unclear. In the present study, we hypothesized that emodin exerts its antitumor effect by participating in the regulation of the DNA methylation level. Our research showed that emodin inhibited the growth of pancreatic cancer PANC-1 cells in a dose- and time-dependent manner. Dot-blot results showed that 40 µM emodin significantly inhibited genomic 5 mC expression in the PANC-1 cells, and mRNA-Seq showed that different concentrations of emodin could alter the gene expression profile in the PANC-1 cells. BSP confirmed that the methylation levels of P16, RASSF1A and ppENK were decreased, while concomitantly the unmethylated status was increased. RT-PCR and western blotting results confirmed that the low expression or absence of expression of mRNA and protein in the PANC-1 cells was re-expressed following treatment with emodin. In conclusion, our study for the first time suggests that emodin inhibits pancreatic cancer cell growth, which may be related to the demethylation of tumor-suppressor genes. The related mechanism may be through the inhibition of methyltransferase expression.

Cu-doped ZnO nanorod arrays: the effects of copper precursor and concentration.

Cu-doped ZnO nanorods have been grown at 90°C for 90 min onto a quartz substrate pre-coated with a ZnO seed layer using a hydrothermal method. The influence of copper (Cu) precursor and concentration on the structural, morphological, and optical properties of ZnO nanorods was investigated. X-ray diffraction analysis revealed that the nanorods grown are highly crystalline with a hexagonal wurtzite crystal structure grown along the c-axis. The lattice strain is found to be compressive for all samples, where a minimum compressive strain of -0.114% was obtained when 1 at.% Cu was added from Cu(NO3)2. Scanning electron microscopy was used to investigate morphologies and the diameters of the grown nanorods. The morphological properties of the Cu-doped ZnO nanorods were influenced significantly by the presence of Cu impurities. Near-band edge (NBE) and a broad blue-green emission bands at around 378 and 545 nm, respectively, were observed in the photoluminescence spectra for all samples. The transmittance characteristics showed a slight increase in the visible range, where the total transmittance increased from approximately 80% for the nanorods doped with Cu(CH3COO)2 to approximately 90% for the nanorods that were doped with Cu(NO3)2.

Graphene nanosheets inserted by silver nanoparticles as zero-dimensional nanospacers for dye sensitized solar cells.

Three-dimensional Ag nanoparticle/GNs (Ag/GNs) hybrids as highly efficient counter electrode (CE) materials for dye sensitized solar cells (DSSCs) is described, highlighting the Ag nanoparticles as zero-dimensional nanospacers inserting into GNs to lift the interspacing layer between individual GNs. It is demonstrated that, when the hybrids are used as CE materials for DSSCs, compared to their pure GNs, Ag/GNs hybrids without agglomerates have a significant improvement in their electrochemical properties such as high current density, narrow peak-to-peak separation (Epp) and low charge transfer resistance (RCT). The enhancement of electrochemical performance can be attributed to the increased electrode conductivity, an extended interlayer distance and the reduction of the restacking of graphene sheets due to the insertion of metallic Ag nanoparticles into GNs. The DSSC with this hybrid CE exhibited an energy conversion efficiency (η) of 7.72% with an open circuit voltage (VOC), short circuit photocurrent density (JSC), and fill factor (FF) of 732 mV, 14.67 mA cm(-2), and 71.8%, respectively.

High-efficiency organic dye-sensitized mesoscopic solar cells with a copper redox shuttle.

Based upon the bis(2,9-dimethyl-1,10-phenanthroline)copper(I/II) electron mediator, we present an iodine-free dye-sensitized solar cell exhibiting an impressive power conversion efficiency of 7.0% at 100 mW cm(-2) air mass global (AM1.5G) conditions, which rivals that of a control cell with a conventional iodine redox couple.

High-efficiency dye-sensitized solar cells: the influence of lithium ions on exciton dissociation, charge recombination, and surface states.

We present a time-saving staining protocol based upon the low-toxicity and nonvolatile solvent dimethyl sulfoxide for a high-efficiency dye-sensitized solar cell, which is very critical for the roll-to-roll flexible cell production. Power conversion efficiencies of 11.7-12.1% were achieved under AM1.5G simulated sunlights. The intrinsic roles of lithium cations on efficiency enhancement were scrutinized by measuring transient absorption and electrical impedance spectroscopies. Our studies have revealed that lithium ions can enhance exciton dissociation at the energy-offset dye/titania interface effectively. Charge collection is not found to be a crucial current loss channel in our high-efficiency dye-sensitized solar cell.

A plasma sputtering decoration route to producing thickness-tunable ZnO/TiO(2) core/shell nanorod arrays.

We report a radio frequency magnetron sputtering method for producing TiO(2) shell coatings directly on the surface of ZnO nanorod arrays. ZnO nanorod arrays were firstly fabricated on transparent conducting oxide substrates by a hydrothermal route, and subsequently decorated with TiO(2) by a plasma sputtering deposition process. The core/shell nanorods have single-crystal ZnO cores and anatase TiO(2) shells. The shells are homogeneously coated onto the whole ZnO nanorods without thickness change. This approach enables us to tailor the thickness of the TiO(2) shell for desired photovoltaic applications on a one-nanometer scale. The function of the TiO(2) shell as a blocking layer for increasing charge separation and suppression of the surface recombination was tested in dye-sensitized solar cells. The enhanced photocurrent and open-circuit voltage gave rise to increased photovoltaic efficiency and decreased dark current, indicating successful functioning of the TiO(2) shell.

High efficiency and stable dye-sensitized solar cells with an organic chromophore featuring a binary pi-conjugated spacer.

We employed a binary spacer of orderly conjugated 3,4-ethyldioxythiophene and thienothiophene to construct a wide-spectral response organic chromophore for dye-sensitized solar cells, exhibiting a high power conversion efficiency of 9.8% measured under irradiation of 100 mW cm(-2) air mass 1.5 global (AM1.5G) sunlight and an excellent stability.

Conjugation of selenophene with bipyridine for a high molar extinction coefficient sensitizer in dye-sensitized solar cells.

A high molar extinction coefficient heteroleptic polypyridyl ruthenium sensitizer, featuring a conjugated electron-rich selenophene unit in its ancillary ligand, has been synthesized and demonstrated as an efficient sensitizer in dye-sensitized solar cells. A nanocrystalline titania film stained with this sensitizer shows improved optical absorptivity, which is highly desirable for dye-sensitized solar cells with a thin photoactive layer. With preliminary testing, this sensitizer has already achieved a high efficiency of 10.6% measured under the air mass 1.5 global conditions.

Large-scale synthesis and microwave absorption enhancement of actinomorphic tubular ZnO/CoFe2O4 nanocomposites.

Actinomorphic tubular ZnO/CoFe(2)O(4) nanocomposites were fabricated in large scale via a simple solution method at low temperature. The phase structures, morphologies, particle size, shell thickness, chemical compositions of the composites have been characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The as-synthesized nanocomposites were uniformly dispersed into the phenolic resin then the mixture was pasted on metal plate with the area of 200 mm x 200 mm as the microwave absorption test plate. The test of microwave absorption was carried out by the radar-absorbing materials (RAM) reflectivity far field radar cross-section (RCS) method. The range of microwave absorption is from 2 to 18 Hz and the best microwave absorption reach to 28.2 dB at 8.5 Hz. The results indicate that the composites are of excellence with respect to microwave absorption.

Ultrasonic-assisted synthesis of highly dispersed MoO3 nanospheres using 3-mercaptopropyltrimethoxysilane.

With ultrasonic irradiation as assistance, highly dispersed MoO(3) nanospheres were synthesized using silane coupling agent 3-mercaptopropyltrimethoxysilane HS-(CH(2))(3)Si(OCH(3))(3) (MPTS) as figuration agent. The results of X-ray powder diffractometer (XRD) showed that the precursor was hexagonal molybdenum oxide hydrate (MoO(3).0.55H(2)O). It was converted into orthorhombic MoO(3) after annealed at 400 degrees C for 2h. Transmission electron microscopy (TEM) showed that MoO(3).0.55H(2)O and MoO(3) nanoparticles were spherical with particle-size distribution of ca. 30-80 nm and 25-75 nm, respectively. Results indicated that MPTS and ultrasonic irradiation played important role in formation of highly dispersed MoO(3) nanospheres. X-ray photoelectron spectroscopy (XPS) was also adopted to confirm the growth mechanism. The possible cause of formation was based on dispersion function of ultrasonic irradiation and figuration of MPTS.

Growth of dumbbell-like ZnO microcrystals under mild conditions and their photoluminescence properties.

Large-scale uniform dumbbell-like ZnO microcrystals were successfully synthesized via a facile solution method under mild conditions. The as-prepared dumbbells, with lengths of 3.5-5.4 microm and diameters of 1.3-1.8 microm, possess a single-crystal hexagonal structure and grow along the [0001] direction. The influence of the reactant concentration on the size and shapes of the ZnO samples had been studied, and the results revealed that the reactant concentration plays a crucial role in determining final morphologies of the samples. Moreover, the evolution process of the dumbbell-like ZnO microcrystals was viewed by field-emission scanning electron microscopy (FE-SEM) characterization, and a possible formation mechanism was proposed. In addition, optical properties of the ZnO samples prepared at different reaction times were also investigated by photoluminescence (PL) spectroscopy. The room-temperature PL spectrum of the dumbbell-like ZnO microcrystals shows a strong UV emission peak. The UV emission is further identified to originate from the radiative free-exciton recombination by the temperature-dependent PL.