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Anewtype carbon nanotube-based gas sensor: palladium nanoparticles decorated singlewalled carbon nanotube film/SiO2/Si (Pd-SWCNT film/SiO2/Si) heterostructures were fabricated by a simple and practical filtration method. When used for hydrogen (H2) sensing, the Pd-SWCNT film/SiO2/p-Si heterostructure shows very high H2 response, which is tens of times higher than that of Pd-SWCNT film resistance-typeH2 sensor in this paper and is superior to those of carbon nanotube-based resistance-type H2 sensors reported previously. The mechanism of the enhanced H2 response can be explained by thermionic emission theory and interfacial effect. [ABSTRACT FROM AUTHOR]

The identification of LSD1-like genes in parasite, green algae, moss, pine, and monocot and dicot species allowed us to trace the phylogenetic history of this gene family. Computational analysis showed that the diversification of members of this family could be dated back to the early stage of plant evolution. The evolution of plant LSD1-like genes was possibly shaped by two duplication events. These proteins, which contain three copies of the LSD1 zinc finger (zf-LSD1) domain within their entire polypeptides and play crucial roles in modulating disease defense and cell death, resulted from the second duplication. A gain of zf-LSD1 domain model was reasonable for explaining the origination of three-zf-LSD1 domain-containing proteins. The zf-LSD1 domain phylogeny showed that the middle (M) and C-terminal (C) domains originated from a common ancestor; the N-terminal (N) domain might be more ancient than the former two. The divergence of the N, M, and C domains was well before the monocot-dicot split. Coevolution analysis revealed that four intramolecular domain pairs, including the N domain and the interregion between the M and the C domains (INTER2), the M and C domain, the N- and C-terminus, and the M domain and C-terminus, possibly coevolved during the evolution of three-zf-LSD1 domain-containing proteins. The three zf-LSD1 domains are evolutionary conserved. Thus, the differences at the N- and C-terminus would be crucial for functional specificity of LSD1 genes. Strong functional constraints should work on the zf-LSD1 domains, whereas reduced functional constraint was found in the INTER2 region. Functional divergence analysis showed that three-zf-LSD1 domain-containing proteins were significantly functionally divergent from those proteins containing only one zf-LSD1 domain, a result demonstrating that shifted evolutionary rates between the two clusters were significantly different from each other. [ABSTRACT FROM AUTHOR]

The article presents a study on pathogenesis-related protein-type (PR) genes in Oryza sativa. It was found that PR-1 genes contain a hydrophobic signal sequence and the mature PR-1 proteins have 6 conserved cysteine residues forming disulphide bridges. A phylogenetic analysis has found that rice PR-1 can be divided into 3 groups, in which the first group was mostly composed of PR-1 proteins, the acidic PR-1 in second group and the basic form in group 3.

Serine carboxypeptidases (SCPs) comprise a large family of protein hydrolyzing enzymes and have roles ranging from protein turnover and C-terminal processing to wound responses and xenobiotic metabolism. The proteins can be classified into three groups, namely carboxypeptidase I, II and III, based on their coding protein sequences and the fact that each family is characterized by a central catalytic domain of unique topology designated as the “α/β hydrolase fold”. The available SCP protein sequences have been utilized as datasets to build a HMM (hidden Markov model) profile, which is used to search the rice ( Oryza sativa L. ssp. japonica) proteome. A total of 71 SCP and serine carboxypeptidase-like (SCPL) protein-coding genes exist in rice. The intron-exon structure, chromosome localization, expression and characteristics of encoded protein sequences of the 71 putative genes are reviewed. [ABSTRACT FROM AUTHOR]

The Pd doped amorphous carbon (a-C:Pd) films were deposited on n-Si substrates with or without a native SiO2 layer using magnetron sputtering. The photovoltaic characteristics of the a-C:Pd/SiO2/Si and a-C:Pd/Si junctions were studied. It is found that under light illumination of 15 mW/cm2 at room temperature, the a-C:Pd/SiO2/Si solar cell fabricated at 350 °C has a high power conversion efficiency of 4.7%, which is much better than the a-C/Si junctions reported before. The enhanced conversion efficiency is ascribed to the Pd doping and the increase in sp2-bonded carbon clusters in the carbon film caused by the high temperature deposition. [ABSTRACT FROM AUTHOR]

Novel core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons (MWCNT@GONRs) nanohybrids were successfully prepared using a modified chemical longitudinal unzipping method. Subsequently, the MWCNT@GONRs nanohybrids were used as fillers to enhance the gas separation performance of polyimide based mixed matrix membranes (MMMs). It is found that MMMs concurrently exhibited higher gas selectivity and higher gas permeability compared to pristine polyimide. The high gas selectivity could be attributed to the GONRs shell, which provided a selective barrier and large gas adsorbed area, while the high gas permeability resulted from the hollow structured MWCNTs core with smooth internal surface, which acted as a rapid transport channel. MWCNT@GONRs could be promising candidates to improve gas separation performance of MMMs due to the unique microstructures, ease of synthesis and low filling loading. [ABSTRACT FROM AUTHOR]

Polyacrylonitrile/graphene oxide (PAN/GO) composite fibers with spindle-knot structure have been fabricated by facile electrospinning and then hydrolyzed (H-PAN/GO) for tailoring their chemical features, and their separation performance for oil-water is evaluated. Herein, bio-inspired spindle-knot structures are induced by the GO sheets, which may be attributed to the mismatch between GO size and fiber diameter and the strong interaction between PAN and GO. It is found that H-PAN/GO membrane with GO concentration at 7% (H-PAN/GO7%) is superhydrophilic in air and ultralow-oil-adhesion under water. As a result, the H-PAN/GO7% membrane exhibits ultra-high flux (~3500 LMH), satisfied rejection ration (~99%) and outstanding flux recovery ratio (~99%) for separating oil-water emulsion. These outstanding separation performances mainly are attributed to the combination of chemical features of hydrolyzed PAN and spindle-knotted structure induced by GO. Moreover, self-transport of oil along spindle-knotted fiber under water is demonstrated by Lattice Boltzmann method (LBM) and the anti-fouling mechanism of this structure was also explained in this paper. The H-PAN/GO fibrous membrane offers a novel insight into fabricating next generation membrane to separate oil-water emulsion. [ABSTRACT FROM AUTHOR]

Bulk-like molybdenum disulfide (MoS2) thin films were deposited on the surface of p-type Si substrates using dc magnetron sputtering technique and MoS2/Si p-n junctions were formed. The vibrating modes of E1 2g and A1g were observed from the Raman spectrum of the MoS2 films. The current density versus voltage (J-V) characteristics of the junction were investigated. A typical J-V rectifying effect with a turn-on voltage of 0.2V was shown. In different voltage range, the electrical transporting of the junction was dominated by diffusion current and recombination current, respectively. Under the light illumination of 1 5mW cm-2, the p-n junction exhibited obvious photovoltaic characteristics with a short-circuit current density of 3.2 mA cm-2 and open-circuit voltage of 0.14 V. The fill factor and energy conversion efficiency were 42.4% and 1.3%, respectively. According to the determination of the Fermi-energy level (~4.65 eV) and energy-band gap (~1.45 eV) of the MoS2 films by capacitance-voltage curve and ultraviolet-visible transmission spectra, the mechanisms of the electrical and photovoltaic characteristics were discussed in terms of the energy-band structure of the MoS2/Si p-n junctions. The results hold the promise for the integration of MoS2 thin films with commercially available Si-based electronics in high-efficient photovoltaic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mesh showed reliable superhydrophilicity, mechanical durability, ultra-high separation fluxes and rejections for separating oily wastewater. • A strategy of scalable and robust hydrophilic modification was successfully developed by uniformly oxidizing and then coating tough sodium alginate/phytic acid hydrogel with the hydrogen-bonded-ionic double network. • This developed mesh with recyclability and durability is promising for low-cost, large-scale and long-term treatment of oily wastewater. Oily wastewater, mainly from the petroleum related industries, have posed on extremely serious waste of water resources and oil resources. Superwetting membrane technology is considered to be the most effective method to treat oily wastewater. And a scalable strategy to prepare robust superhydrophilic membrane is the core issue. In this work, a superhydrophilic mesh was successfully prepared via facile oxidation and coating strategy. The oxidative treatment successfully fabricated large-scale uniform hierarchical morphologies on mesh. And the coating of sodium alginate/phytic acid hydrogel on the hierarchical mesh synthesized tough and controllable superhydrophilic layer, based the hydrogen-bonded-ionic double-network design. This developed mesh was superhydrophilic, underwater superoleophobic (∼171°) and antifouling. And this mesh also possessed strong mechanical durability, excellent chemical durability, ultra-high separation fluxes (28,220–54,340 L·m−2·h−1) and rejections (99.99%) for separating oily wastewater. In addition, with the assistance of calcination, this mesh could be recyclable. This developed mesh with recyclability and scalability looks promising for low-cost, large-scale and long-term treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

A ultrahigh performance humidity sensor based on graphene oxide (GO)/poly(diallyldimethylammonium chloride) (PDDA) nanocomposite film was reported in this paper. The multilayered film of GO/PDDA was fabricated on a polyimide substrate using layer-by-layer self-assembly technique. The structures of the self-assembled films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The humidity sensing behaviors of the film sensor were investigated at room temperature over a wide range of 11-97% relative humidity. Unprecedented response of up to 265,640% was demonstrated for the presented sensor when exposed to varying relative humidity levels, which is better than that of the best conventional humidity sensor. Furthermore, the presented sensor exhibited ultrafast response and recovery times capable of monitoring human breath. Moreover, the possible humidity sensing mechanism of the proposed sensor was discussed by using complex impedance spectra and bode diagrams. This measurement results observed highlight the layer-by-layer self-assembled graphene oxide/polyelectrolyte film is a candidate material for constructing humidity sensors. [ABSTRACT FROM AUTHOR]

A new kind of hierarchical ZnO nanorod with a periodical structure was successfully synthesized using a mixture of Zn, ZnO and carbon as the source through the chemical vapour deposition method. A self-catalyzed growth process dominated by a negative feedback mechanism was proposed to explain its growth. Combining the experimental conditions, the change in reagent supersaturation through a whole reaction was analysed and a three-step growth model was built. Two contrasting experiments were further conducted to study the relation between microscopic conditions and the growth behaviour of the nanostructure. The results and discussions were a beneficial exploration and could reference for controlled growth of nanostructure through modulating the supersaturation by source. Furthermore these obtained hierarchical nanostructures are also expected to have potential applications as functional blocks in future nanodevices. [ABSTRACT FROM AUTHOR]

Hybrids lose heterotic yield advantage when multiplied sexually via meiosis. A potential alternative breeding system for hybrids is apospory, where female gametes develop without meiosis. Common among grasses, apospory begins in the nucellus, where aposporous initials (AIs) appear near the sexual megaspore mother cell (MeMC). The cellular origin of AIs is obscure, but one possibility, suggested by the mac1 and msp1 mutants of maize and rice, is that AIs are apomeiotic derivatives of the additional MeMCs that appear when genetic control over sporocyte numbers is relaxed. MULTIPLE SPOROCYTES1 ( MSP1) encodes a leucine-rich-repeat receptor kinase, which is orthologous to EXS/EMS1 in Arabidopsis. Like mac1 and msp1, exs/ ems1 mutants produce extra sporocytes in the anther instead of a tapetum, causing male sterility. This phenotype is copied in mutants of TAPETUM DETERMINANT1 ( TPD1), which encodes a small protein hypothesized to be an extracellular ligand of EXS/EMS1. Here we show that rice contains two TPD1-like genes, OsTDL1A and OsTDL1B. Both are co-expressed with MSP1 in anthers during meiosis, but only OsTDL1A and MSP1 are co-expressed in the ovule. OsTDL1A binds to the leucine-rich-repeat domain of MSP1 in yeast two-hybrid assays and bimolecular fluorescence complementation in onion cells; OsTDL1B lacks this capacity. When driven by the maize Ubiquitin1 promoter, RNA interference against OsTDL1A phenocopies msp1 in the ovule but not in the anther. Thus, RNAi produces multiple MeMCs without causing male sterility. We conclude that OsTDL1A binds MSP1 in order to limit sporocyte numbers. OsTDL1A-RNAi lines may be suitable starting points for achieving synthetic apospory in rice. [ABSTRACT FROM AUTHOR]

A simple hydrogenation treatment is used to synthesize unique oxygen-deficient TiO2 with a core/shell structure (TiO2@TiO2−xHx), superior to the high H2-pressure process (under 20 bar for five days). It is demonstrated that oxygen-deficient TiO2 nanoparticle film/Si heterojunction possesses improved photoresponse performance compared to the untreated TiO2 nanoparticle film/Si heterojunction. Particularly, under 900 nm of 0.5 μW cm−2, the oxygen-deficient TiO2 nanoparticle film (TiO2@TiO2−xHx core–shell nanoparticle film)/Si heterojunction shows high responsivity (R) of 336 A W−1, prominent sensitivity (S) of 1.3 × 107 cm2 W−1, accompanied with a fast rise and decay time of 6 and 5 ms, respectively. Significantly, the detectivity (D*) of the photodetector is up to 1.17 × 1014 cm Hz1/2 W−1, which is better than that reported in metal oxide nanomaterials/Si heterojunction photodetectors, and is 4–5 orders of magnitude higher than some 2D nanosheets/Si heterojunctions of 109–1010 cm Hz1/2 W−1, indicating the excellent ability to detect weak signals. The oxygen vacancies generated in amorphous shell TiO2−xHx make the Fermi level of TiO2−x shift near the conduction band minimum and can lead to reduced dark current. The high absorption and reduced dark current of the heterojunction ensure excellent photoresponse properties of oxygen-deficient TiO2 nanoparticle film/Si heterojunction. The H-reduced oxygen-deficient amorphous shell may be an excellent candidate to enhance the photoresponse performance of metal oxide/Si heterojunction. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, polyaniline nanofibers/TiO2 nanotubes (PANI/TiO2) heterojunction thin film has been prepared on Pt interdigital electrodes by layer-by-layer self-assembly method and applied in room temperature NH3 detection. It is found that the optimal self-assembly layer number is three (PANI/TiO2-3) compared to one layer (PANI/TiO2-1) and five layers (PANI/TiO2-5). The PANI/TiO2-3 thin film sensor possesses superior response characteristics compared with our other PANI based sensors, including higher response value (336%@5 ppm NH3), acceptable response/recovery time (110 s/1 086 s@5 ppm NH3), low detection limit (0.5 ppm), and remarkable selectivity. The enhanced gas sensing performances could be ascribed to the tremendous variation of the carrier concentration caused by the p-n junctions as well as the increased specific surface area and pore volume. This work not only offers a superb strategy to fabricate heterojunction thin film but also accelerates the development of room-temperature operable NH3 sensors. [ABSTRACT FROM AUTHOR]

Development of low energy cost membranes for separating helium from natural gas is highly desired. Using van der Waals-corrected first-principles density functional theory (DFT) calculations, we theoretically investigate the helium separation performance of divacancy-defective germanene. The 555 777 divacancy-defective germanene presents a 0.53 eV energy barrier for helium, which is slightly larger than the energy threshold value of gas molecule penetration of a membrane (0.5 eV). Thus, the 555 777 divacancy-defective germanene is difficult for helium to permeate, except under high temperature or pressure. However, the 585 divacancy-defective germanene presents a surmountable energy barrier (0.27 eV) for helium, and it shows extremely high helium selectivities relative to other studied gas molecules. Especially, the He/Ne selectivity can be as high as 1 × 104 at room temperature. Together with the acceptable permeance for helium, the 585 divacancy-defective germanene can be used for helium separation with remarkably good performance. [ABSTRACT FROM AUTHOR]