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Wave energy is one of the most promising renewable energy sources. The approaches for wave energy harvesting have been attracting more and more attentions all over the world. Although triboelectric nanogenerators (TENGs) based on liquid-solid interface have offered a new method for wave energy harvesting, some challenges still remain such as the relatively low energy power density and energy conversion efficiency. Here, we introduce a liquid-solid generator with electrode arrays that allows for improved wave energy harvesting compared to conventional TENG. The design of 3D electrodes above dielectric layer engenders a bulk effect that connect the electrode array, the polymer layer and bulk water into a closed-looped system. The arrayed generator can also be assembled easily and the instantaneous output power density can be enhanced from 2.7 W/m2 to 11.7 W/m2 with the 3D electrodes. We envision that this bulk effect generator based on liquid-solid interface will open new insight in blue energy harvesting in the future.

Coupling the heterojunction system with surface plasmon resonance (SPR) effect is an innovative and feasible strategy to improve photocatalyst. An excellent Z-scheme CdSe-Ag-WO3-Ag photocatalyst was constructed via continuous photo-assisted process, which exhibited superior photocatalytic activity in H2 evolution (448.31 μmol•g−1 for 4 h) with simultaneous degradation of CFZ (96.32% in just 30 min) compared with CdSe-WO3, CdSe and WO3. This developed system conforms to Z-scheme electron transfer mode: CB/WO3 to Ag NPs, Ag NPs to VB/CdSe. It was verified by experiments, DFT simulation and in situ XPS characterization. So the strong reducing electron in CB/CdSe and the strong oxidizing hole in VB/WO3 were retained for H2 evolution and degradation, respectively. The coupling Ag with Z-scheme heterojunction can realize rapid electron transfer and utilization. Because the Z-scheme heterojunction inhibits recombination of carriers of the single catalyst itself and enhances electrons life, Ag acts as conductive channel to accelerate electrons transfer, and the surface defects of CdSe and Schottky barrier reduce the energy loss during the electron transmission process. This work provides new insights for boosts electron transfer to improve photocatalytic performance.

Mn-TiO2/carbon cloth (CC) membranes with various Mn doping concentrations have been synthesized by hydrothermal process for efficient oil-water separation. The prepared membranes with superhydrophilic in air and underwater superoleophobic have the excellent self-cleaning performance under visible light driven, and these performances are strongly influenced by Mn doping concentration. The separation efficiency of the membranes is above 98% even after 56 oil-water separation cycles for various oil-water mixtures due to the d-states hybridization of Mn ions. Importantly, the membranes also have the good mechanical performance, reusability, chemical durability, and even work in acid, alkali and salt environment. The aforementioned properties and the easily scale-up production technique ensure that the Mn-TiO2/CC membrane has a potential application in practical treatment of oil spillage clean-up and oily wastewater.

Sinopodophyllum hexandrum is a perennial rhizomatous herb and its rhizome produces anti-cancer compound podophyllotoxin (PPT). As a result of overexploitation of wild resources and lack of large-scale cultivation, it is currently an endangered species. An effective and conventional propagation method is by seed, but seed germination is erratic attributed to the barriers from seed coat and thick-walled endosperm. While several proteins and genes that are involved in cell wall loosening and endosperm weakening have been identified, the mechanism responsible for regulating germination has not been systematically mapped. Here, transcriptomics profiles of S. hexandrum during seed germination were performed, genes expression was validated as well as metabolites and hormones were measured. Over one thousand genes were observed to be differentially co-expressed at the five germination stages. Functional annotation classified 67 genes associated with cell wall loosening and endosperm weakening (25), primary metabolism and energy (16), hormone biosynthesis and bio-signaling (15), radicle growth (5), and transcription factor (6). The expression levels of genes involved in hydrolases (i.e. XTHs, GLCs, MANs, EXPAs, AGALs, PECSs and PGs), metabolites (i.e. starch, oligosaccharides, proteins, lipids and fatty acids) and hormones (i.e. GA3, ABA and IAA) were almost consistent with changes of seed water uptake, contents of metabolites and hormones, and cell wall modifications. This combinational analysis of transcriptomics with targeted metabolites and hormones provides new insights into seed germination of S. hexandrum.

e13061 Background: Worldwide, breast cancer is the most common type of cancers and the presentation of drug resistance is often associated with poor prognosis. Previous studies have shown the mechanism of drug resistance was affected by apoptosis at different levels in the signaling cascades. This article is aimed to explore the relationship between the serum and glucocorticoid-regulated kinase 1 (SGK1) and apoptosis in invasive breast cancer (IBC). Methods: We evaluated the expression of SGK1 in IBC using publicly available data from The Cancer Genome Atlas (TCGA) and Curtis Breast program. TaqMan probe-based qRT-PCR assay and Western Blot analysis were performed to quantitatively detect the expression of SGK1 at RNA and protein levels in the IBC specimens. Clinicopathologic characteristics associated with overall survival were tested by Cox regression. Gene Set Enrichment Analysis (GSEA) was performed to mine the biological pathways involved in IBC pathogenesis related SGK1 regulatory network using MSigDB database. Immunohistochemistry staining (IHC) was used to detect apoptotic markers Fas, Bcl2 and SGK1 in the IBC specimens. Results: Totally 1109 IBC samples with SGK1 expression data were downloaded from TCGA databases for analyzed. SGK1 expression was elevated in normal breast tissues compared with both invasive ductal carcinoma and invasive lobular carcinoma (p < 0.0001). Among them, SKG expression in 112 tumor tissues was significantly lower than that in paracancerous tissues, especially in advanced patients with TNM stage IV. Western Blot and qRT-PCR assay confirmed that SGK1 expression in IBC was distinctly lower than normal. The Kaplan-Meier survival analysis showed that decreased expression of SGK1 was significantly correlated with the clinical stage (p = 0.036). In Curtis Breast program, we further verified SGK1 gene expression was reduced in stage IV than stage I. The univariate analysis demonstrated that clinicopathologic variables associated with poor survival include age, advanced stage, lymph nodes, distant metastasis and deep myometrial invasion. GSEA revealed that apoptosis was differentially enriched when SGK1 was highly expressed. Similarly, TCGA data indicated that the positive rate of SGK1 was higher in Fas positive IBCs, and the same result was also obtained by IHC in the IBC specimens. Conclusions: Expression of SGK1 regulated apoptosis in invasive breast carcinoma, which might be a potential therapeutic target to overcome refractory and drug-resistant breast cancer.

e15081 Background: Gamma-interferon Inducible Lysosomal Thiolreductase (GILT) is constitutively expressed in most antigens endocytosed by antigen presenting cells (APCs), and its function is to catalyze the reduction of disulfide (S-S) bonds in protein substrates. The cytokine CXCL16 is one of the only two known plasma membrane chemokines which induces chemotaxis of activated T cells and bone marrow plasma cells in tumor microenvironment. It contains a free end folded by two sulfur bonds and therefore could also be a zymolyte of GILT. Previous studies found that specific receptor of CXCL16, CXCR6, was significantly overexpressed in breast cancer tissues and metastatic axillary lymph nodes. We suppose whether CXCR6/CXCL16 axis is regulated by GILT and affect tumor microenvironment, thereby eliciting specific anti-tumor immune responses in breast cancer (BC). Methods: GILT expression in BC was evaluated using publicly available data from The Cancer Genome Atlas (TCGA). GILT gene was analyzed in UALCAN ( http://ualcan.path.uab.edu/analysis-prot.html ) . In vitro, Immunohistochemistry (IHC) was conducted to examine the location and relation of GILT and CXCR6. Gene Set Enrichment Analysis (GSEA) was performed to mine the biological pathways involved in BC related GILT regulatory network. The expression of GILT at protein and RNA levels were detected by Western Blot and RT-PCR assay. Overexpression and knockdown of GILT in BC cell lines was carried out to further analyzed the correlation between GILT and CXCL16/CXCR6. Results: TCGA database showed that GILT expression was increased in the stroma of BC compared with normal, and was correlated to shorter BC overall survival. GSEA suggested that the expression of GILT was associated with chemotactic factors. Pearson analysis and IHC showed GILT had a strong correlation with CXCL16/CXCR6 axis in the aspect of angiogenesis and immunity. qRT-PCR and Western Blot assay also revealed that GILT had high expression in BC. Besides, patients with high expression of GILT in IHC simultaneously showed high immunoreactive to macrophage markers, which was related to neovascularization and anti-tumor immune responses. Compared with the normal breast cell line MCF-10A, GILT protein had high expression in Hs578T and low expression in MDA-MB-231 cell line. GILT was overexpressed in MDA-MB-231 and knockdown in Hs578T. Result showed that high level GILT promoted the production of CXCL16/CXCR6,while GILT siRNA knockdown inhibited the production of CXCL16/CXCR6. Conclusions: GILT could catalyze CXCL16 in BC, function as a key mechanism to affect tumor microenvironment through CXCR6/CXCL16 pathway. GILT-activated CXCL16 levels showed a strong connection with unfavorable outcomes in BC, which could be a potential biomarker of prognosis and a novel therapeutic target.

The nanoscale distribution of Bi in InPBi is determined by atom probe tomography and transmission electron microscopy. The distribution of Bi atoms is not uniform both along the growth direction and within the film plane. A statistically high Bi-content region is observed at the bottom of the InPBi layer close to the InPBi/InP interface. Bi-rich V-shaped walls on the (−111) and (1–11) planes close to the InPBi/InP interface and quasi-periodic Bi-rich nanowalls in the (1–10) plane with a periodicity of about 100 nm are observed. A growth model is proposed to explain the formation of these unique Bi-related nanoscale features. These features can significantly affect the deep levels of the InPBi epilayer. The regions in the InPBi layer with or without these Bi-related nanostructures exhibit different optical properties.

As a promising new class of near-infrared light emitters, GaAsBi laser diodes (LDs) are considered to have a high energy efficiency and an insensitive temperature dependence of the band gap. In this paper, we realize the longest ever reported lasing wavelength up to 1.142 μm at room temperature in GaAsBi0.058/GaAs quantum well LDs grown by molecular beam epitaxy. The output power is up to 127 mW at 300 K under pulsed mode. We also demonstrate continuous wave mode operation up to 273 K for the first time. The temperature coefficient of the GaAsBi/GaAs LD is 0.26 nm/K in the temperature range of 77–350 K, lower than that of both InGaAsP/InP and InGaAs/GaAs LDs. The characteristic temperature is extracted to be 139 K in the temperature range of 77–225 K and decreases to 79 K at 225–350 K.

We have fabricated highly transparent Al/Bi2Te3/Al superconductor/normal metal/superconductor double-barrier heterostructures. Transport measurements reveal the presence of multiple Andreev reflections related to two distinct energy gaps that we identify as the induced superconducting gap in the two electrodes. The realization of high-transparency Josephson junctions with topological insulators is an important step towards the study of topological superconductivity and Majorana fermions.

We propose a new type II InGaAs/GaAsBi quantum well structure to extend light emission wavelength on GaAs and demonstrate the effect experimentally. Type II InGaAs/GaAsBi QWs were grown using molecular beam epitaxy. Room temperature photoluminescence confirms wavelength extension to 1230 nm, 82 and 208 nm longer than that of the type I GaAsBi and InGaAs QW with the same Bi or In content, respectively. The PL intensity is enhanced by more than ten times than the GaAsBi QW. Our results show that the type II dilute bismide QW has potentials for making telecom lasers on GaAs.

The electronic and optical properties of strained monolayer arsenene were calculated based on first-principle density functional theory. Our theoretical calculations demonstrated that monolayer arsenene was transformed from indirect to direct band gap semiconductor by inducing uniaxial tensile strain along armchair and zigzag directions. Compared to the biaxial tensile strain of 0.04, this transformation occurred at the strain of 0.06 and 0.10 along armchair and zigzag direction, respectively. Spin–orbital coupling is available to tune the bandgaps. The spin–orbit interaction opens a 0.2 eV bandgap in the Γ-point on the unstrained monolayer arsenene. The absorption properties were calculated and a clear red shift was observed with the increasing strain.

InPBi exhibits broad and strong photoluminescence at room temperature, and is a potential candidate for fabricating super-luminescence diodes applied in optical coherence tomography. In this paper, the strained InPBi quantum dot (QD) embedded in the AlGaAs barrier on a GaAs platform is proposed to enhance the light emission efficiency and further broaden the photoluminescence spectrum. The finite element method is used to calculate the strain distribution, band alignment and confined levels of InPBi QDs. The carrier recombinations between the ground states and the deep levels are systematically investigated. A high Bi content and a flat QD shape are found preferable for fabricating super-luminescence diodes with high efficiency and a broad emission spectrum.

The teaching experimental system for industrial robot electrical connectors based on PLC is designed. The system combines reliability acceleration test theory, constant temperature PID control technology, electric servo drive technology, PLC control technology, insertion force detection technology, microscopic observation technology and electromechanical transmission control technology to form a set of multi-functional advanced teaching experimental system with optical - electromechanical integration, which can not only complete the basic teaching experiments of classical electromechanical transmission control, insertion force sensing, temperature PID control and pin surface friction and wear morphology observation, but also carry out the research and teaching experiment on service reliability of connectors under various acceleration conditions such as ambient temperature and plugging speed. It has better advanced teaching experimental equipment and higher application value.

Exosomes derived from differentiated P12 cells and MSCs were proved to suppress apoptosis of neuron cells, and phosphatase and tensin homolog pseudogene 1 (PTENP1) was reported to inhibit cell proliferation. In this study, we aimed to investigate the role of PTENP1 in the process of post-spinal cord injury (SCI) recovery, so as to evaluate the therapeutic effects of exosomes derived from MSCs transfected with PTENP1 short hairpin RNA (shRNA), as a type of novel biomarkers in the treatment of SCI. Electron microscopy was used to observe the morphology of different exosomes. Real-time polymerase chain reaction and western blot, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry, Nissl staining, immunohistochemistry assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were conducted to investigate and validate the underlying molecular signaling pathway. PTENP1-shRNA downregulated PTENP1 and PTEN while upregulating miR-21 and miR-19b. PTENP1-shRNA also accelerated cell apoptosis and reduced cell viability. In addition, PTENP1 reduced the miR-21 and miR-19b expression by directly targeting miR-21 and miR-19b. Meanwhile, both miR-21 and miR-19b reduced the expression of PTEN by directly targeting the 3'-untranslated region of PTEN. Furthermore, PTEN level and apoptosis index of neuron cells was the highest in the SCI group, while the treatment with exosomes+PTENP1-shRNA reduced the PTEN expression to a level similar to that in the sham group. Finally, PTENP1 inhibited miR-21 and miR-19b expression but upregulated PTEN expression. The upregulation of miR-21/miR-19b also suppressed the apoptosis of neuron cells by downregulating the PTEN expression. PTENP1 is involved in the recovery of SCI by regulating the expression of miR-19b and miR-21, and exosomes from PTENP1-shRNA-transfected cells may be used as a novel biomarker in SCI treatment.

Extensive efforts have been made to harvest energy from water in the form of raindrops

A pressing challenge in engineering devices with topological insulators (TIs) is that electron transport is dominated by the bulk conductance, and so dissipationless surface states account for only a small fraction of the conductance. Enhancing the surface-to-volume ratio is a common method to enhance the relative contribution of such states. In thin films with reduced thickness, the confinement results in symmetry-breaking and is critical for the experimental observation of topologically protected surface states. We employ micro-Raman and tip-enhanced Raman spectroscopy to examine three different mechanisms of symmetry breaking in Bi2Te3 TI thin films: surface plasmon generation, charge transfer, and application of a periodic strain potential. These mechanisms are facilitated by semiconducting and insulating substrates that modify the electronic and mechanical conditions at the sample surface and alter the long-range interactions between Bi2Te3 and the substrate. We confirm the symmetry breaking in Bi2Te3 via the emergence of the Raman-forbidden $${{\boldsymbol{A}}}_{{\bf{1}}{\boldsymbol{u}}}^{{\bf{2}}}$$ A 1 u 2 mode. Our results suggest that topological surface states can exist at the Bi2Te3/substrate interface, which is in a good agreement with previous theoretical results predicting the tunability of the vertical location of helical surface states in TI/substrate heterostructures.

Carcass meat yield is an important carcass trait that contributes to the production efficiency and economic benefits in beef cattle. It is therefore critical to identify quantitative trait loci associated with carcass traits to enable selection. Our previous studies have identified several causal variants within the pleomorphic adenoma gene 1 (

Just as the innovation of electronic diodes that allow the current to flow in one direction provides a foundation for the development of digital technologies, the engineering of surfaces or devices that allow the directional and spontaneous transport of fluids, termed liquid diodes, is highly desired in a wide spectrum of applications ranging from medical microfluidics, advanced printing, heat management and water collection to oil–water separation. Recent advances in manufacturing, visualization techniques, and biomimetics have led to exciting progress in the design of various liquid diodes. In spite of exciting progress, formulating a general framework broad enough to guide the design, optimization and fabrication of engineered liquid diodes remains a challenging task to date. In this review, we first present an overview of the development of biological and engineered liquid diodes to elucidate how to control the surface chemistry and topography to regulate the transport of liquids without the need for external energy. Then the latest design strategies allowing for the creation of longitudinal and transverse liquid diodes are discussed and compared. We also define some figures of merit such as the rectification coefficient and the transport velocity and distance to quantify the performance of liquid diodes. Finally, we highlight perspectives on the development of engineered liquid diodes that transcend nature and adapt to various practical applications.

Background Infectious bursal disease (IBD) is an acute contagious immunosuppressive disease which lead to acute bursal injury and immune dysfunction in poultry. It has caused heavy economic losses in the commercial poultry industry for many years in worldwide. Attenuated live vaccine has widely used in poultry showing some promising signs against IBDV infection. But it has defects such as generating enhanced virulence and immunosuppression prohibits. Therefore, the development of mucosal vaccines using the food-grade lactic acid bacterium is necessary. Here, we construct a recombinant Lactococcus co-expressing the major IBDV antigens VP2 and RCK protein of Salmonella enterica to prevent IBD. Results The recombinant fusion protein VP2-RCK was expressed in a soluble and stable form in the cytoplasm of the recombinant Lactococcus lactis. Animal experiments showed that: (1) the survival rates of the injected immunization inactivated recombinant LAB group and oral immunization live recombinant LAB group were 100% and 80%, respectively; (2) ELISA titers of all serum samples from all experimental groups were negative, but high amounts of specific neutralizing antibodies were detected (1:210 to 1:212); and (3) the bursas of the injected immunization inactivated recombinant LAB group did not suffer damage, as confirmed by clinical observation and bursal histopathological examination. Our results indicate that r-L. lactis-OptiVP2-RCK induces a specific neutralizing-antibody-mediated immune response that confers full protection against very-virulent IBDV (vvIBDV) challenge. Conclusion Lactococcus lactis NZ3900 strain and its matching plasmid pNZ8149 could express the recombinant fusion protein VP2-RCK in a soluble form in the cytoplasm. The protective efficacy of r-L. lactis-OptiVP2-RCK (100%) was better than r-L. lactis-OptiVP2 (0%) which prove RCK protein played its unique role. The neutralizing antibodies titers against infectious bursal disease virus via one-time vaccination with inactivated r-L. lactis-OptiVP2-RCK could reach 1:210 to 1:212, but ELISA titers of all serum samples were negative. For this phenomenon, perhaps because of the change of delivery pathway or the spatial structure of fusion protein. We need further study to test these hypotheses.

Harvesting water kinetic energy is a prospective way to obtain sustainable power. However, conventional water energy harvesting technologies are restricted by specific operating locations and fabrication materials. These techniques urgently need to be improved and supplemented with new methods. Here, we report a novel and universal single electrode droplet-based electricity generator (SE-DEG) that allows converting water droplet kinetic energy into electricity power on any surfaces of artificial or natural materials such as PTFE, glass, wood, aloe, cicada wing, stone and etc. This functionality is endowed by a special configuration characterized by the location of the electrode on the top of dielectric material rather than underlying as in the conventional triboelectric nanogenerator (TENG). Such special configuration can effectively harness the triboelectric charges generated without going through the electrostatic induction process between bottom electrode and the surface in the case of TENG. We envision that SE-DEGs represent a new dimension in ability to harvest abundant hydrodynamic energy everywhere.

Previous works have demonstrated the use of acoustic waves to manipulate microparticles and biological samples on bare glass and silicon superstrates. Traditionally, the surface acoustic wave (SAW) is converted into a Lamb wave propagating within a bare silicon superstrate via a thin coupling agent. The potential impact of acoustically driven microfluidics could be further augmented if applied to superstrates integrated with sensing structures that would allow sequential analysis after sample treatment. In this work, we demonstrate the applicability of acoustically-driven micro-centrifugation on a superstrate with multiple thin film layers to mimic sensing structures on a chip, and characterize the underlying performance. We propose an integrated plug-and-play platform comprised of a reusable SAW device interfaced to a disposable surface-micromachined silicon (SMS) superstrate processed with five layers of thin films. To address the shortcomings of existing coupling agents, we examine and compare the transmission efficiency and long-term stability of four kinds of coupling agents with the aim to enable disposable acoustofluidics applications. To investigate the effect of different superstrates on the performance of droplet centrifugation, we characterize and compare centrifugation on different superstrates. High-performance concentration was realized on the SMS superstrate under different conditions, such as input power, temperature, droplet volume, and particle size and density. In terms of more advanced fluidic handling functionality on a multi-layered SMS superstrate, we demonstrate ultrasonic isopycnic separation between microbeads differentiated by density on the SMS superstrate. The results herein lay the groundwork for realizing particle concentration on complex superstrates processed with multilayer films that represent a range of microfabricated sensors towards a broader goal of integrating acoustically driven concentration capabilities and sensing for applications in diagnostics and fundamental analysis.

The CC@TiO2-Cu membranes with various Cu doping contents have been synthesized via a simple one-step hydrothermal method for oil-water separation application. It is found that a certain amount of Cu doping is beneficial for achieving visible light response and enhance the superhydrophilicity/underwater superoleophobic performance of CC@TiO2-Cu membranes. Importantly, the CC@TiO2-Cu2.5 membrane with cauliflower-like morphology shows excellent self-cleaning and antifouling performance under visible light driven. And its separation efficiency can still maintain up to 99.6% under gravity even after 80 cycles of oil-water separation experiments. The mechanisms of both oil-water separation and photocatalytic self-cleaning for the CC@TiO2-Cu membrane are discussed in detail. The study provides a new concept for designing self-cleaning membrane to apply in oil-water separation.

We report on a new type of nitrogen-doped porous carbon@Co3O4 catalysts, demonstrating high-efficiency for tetracycline (TC) degradation, are synthesized via two steps of simple grinding and calcination treatment. The temperatures of carbonization and oxidation play an important role in determining the structure, morphology, chemical composition and catalytic performance of the catalysts. The C-700-300 catalyst with 3D porous structure demonstrates the best catalytic performance for TC degradation due to the large amount of graphitized nitrogen, large specific surface area and small particle size. The effect of catalyst and peroxymonosulfate (PMS) amount on the catalytic performance are also fully investigated. The mechanism of catalysts to PMS activation for TC degradation is elaborated, which is ascribed to the radical and non-radical pathways. The sulfate radical function in TC degradation from the radical quenching experiment and the non-radical pathway is also discussed to complement the above degradation due to the excessive electron donors in catalysts.

A carbon cloth@TiO2@Ag (CC@TiO2@Ag) membrane has been prepared by two-step method, including the hydrothermal method to make TiO2 grow on carbon cloth and the photodeposition method to synthesize Ag element on CC@TiO2 for oil-water separation. The obtained CC@TiO2@Ag membrane shows the good superhydrophilicity and underwater superoleophobicity due to its hierarchical broccoli-like interface with the good surface roughness and the natural hydrophilicity of TiO2. Importantly, the resultant membrane exhibits a strong self-cleaning ability under visible light irradiation of CC@TiO2@Ag membrane with loading a certain amount of Ag, so that the separation efficiency remains above 99% even after 60 cycles for various oil-water mixtures. Moreover, the CC@TiO2@Ag membrane is flexible and durable. The high separation efficiency and excellent self-cleaning ability of the membrane may own the broad application prospects in the field of oil-water separation.

Single porous nickel disulfide (NiS 2 ) nanoballs and nanohybrids of NiS 2 with reduced graphene oxide (NiS 2 /rGO) were successfully prepared by a simple hydrothermal process in the absence or presence of graphene oxide. NiS 2 /rGO nanocomposites exhibit remarkable electrocatalytic performance for hydrogen evolution from water splitting due to the plentiful active sites in the porous NiS 2 , the improved conductivity and the positive synergetic effect between NiS 2 and rGO. The nanocomposites displayed superior activity for the hydrogen evolution reaction (10 mA cm − 2 vs. − 200 mV, Tafel slope of 52 mV dec − 1 ) and an excellent electrocatalytic stability.

This paper reports abnormal effects of Auger recombination in InGaAs/InAlAs quantum well probed by steady state temperature and excitation-power dependent photoluminescence measurements. The transition from Auger recombination to Shockley–Read–Hall recombination is clearly manifested with rising temperature, and abnormal enhancement of Auger recombination at low temperatures is evidenced. Detailed analysis indicates that such enhancement is positively correlated with strong localization, and can be either relative and due to reduction of Shockley–Read–Hall recombination, or absolute and resulted from the confinement-induced uncertainty of momentum. It suggests that excitation-power dependent photoluminescence measurement is effective to assess the side-effect of the localization, and therefore a convenient evaluation routine of alloy quantum wells.

Strain and stress were simulated using finite element method (FEM) for three III–V-on-Insulator (III–VOI) structures, i.e., InP/SiO2/Si, InP/Al2O3/SiO2/Si, and GaAs/Al2O3/SiO2/Si, fabricated by ion-slicing as the substrates for optoelectronic devices on Si. The thermal strain/stress imposes no risk for optoelectronic structures grown on InPOI at a normal growth temperature using molecular beam epitaxy. Structures grown on GaAsOI are more dangerous than those on InPOI due to a limited critical thickness. The intermedia Al2O3 layer was intended to increase the adherence while it brings in the largest risk. The simulated results reveal thermal stress on Al2O3 over 1 GPa, which is much higher than its critical stress for interfacial fracture. InPOI without an Al2O3 layer is more suitable as the substrate for optoelectronic integration on Si.

InPBi thin film has shown ultra-broad room temperature photoluminescence, which is promising for applications in super-luminescent diodes (SLDs) but met problems with low light emission efficiency. In this paper, InPBi quantum dot (QD) is proposed to serve as the active material for future InPBi SLDs. The quantum confinement for carriers and reduced spatial size of QD structure can improve light emission efficiently. We employ finite element method to simulate strain distribution inside QDs and use the result as input for calculating electronic properties. We systematically investigate different transitions involving carriers on the band edges and the deep levels as a function of Bi composition and InPBi QD geometry embedded in InAlAs lattice matched to InP. A flat QD shape with a moderate Bi content of a few percent over 3.2% would provide the optimal performance of SLDs with a bright and wide spectrum at a short center wavelength, promising for future optical coherence tomography applications. Published version

A pressing challenge in engineering devices with topological insulators (TIs) is that electron transport is dominated by the bulk conductance, and so dissipationless surface states account for only a small fraction of the conductance. Enhancing the surface-to-volume ratio is a common method to enhance the relative contribution of such states. In thin films with reduced thickness, the confinement results in symmetry-breaking and is critical for the experimental observation of topologically protected surface states. We employ micro-Raman and tip-enhanced Raman spectroscopy to examine three different mechanisms of symmetry breaking in Bi2Te3 TI thin films: surface plasmon generation, charge transfer, and application of a periodic strain potential. These mechanisms are facilitated by semiconducting and insulating substrates that modify the electronic and mechanical conditions at the sample surface and alter the long-range interactions between Bi2Te3 and the substrate. We confirm the symmetry breaking in Bi2Te3 via the emergence of the Raman-forbidden \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{A}}}_{{\bf{1}}{\boldsymbol{u}}}^{{\bf{2}}}$$\end{document}A1u2 mode. Our results suggest that topological surface states can exist at the Bi2Te3/substrate interface, which is in a good agreement with previous theoretical results predicting the tunability of the vertical location of helical surface states in TI/substrate heterostructures.

Topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. The key ingredient is an unconventional order parameter, with an orbital component containing a chiral $p_x$ + i$p_y$ wave term. Here we present phase-sensitive measurements, based on the quantum interference in nanoscale Josephson junctions, realized by using Bi$_2$Te$_3$ topological insulator. We demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral $p_x$ + i$p_y$ component. The magnetic field pattern of the junctions shows a dip at zero externally applied magnetic field, which is an incontrovertible signature of the simultaneous existence of 0 and $\pi$ coupling within the junction, inherent to a non trivial order parameter phase. The nano-textured morphology of the Bi$_2$Te$_3$ flakes, and the dramatic role played by thermal strain are the surprising key factors for the display of an unconventional induced order parameter., Comment: 47 pages, 7 figures in the main text and 12 figures in the supplementary material

It is shown that the electron-phonon interaction at a conducting interface between a topological insulator thin film and a semiconductor substrate can be directly probed by means of high-resolution Brillouin light scattering (BLS). The observation of Kohn anomalies in the surface phonon dispersion curves of a 50 nm thick Bi2Te3 film on GaAs, besides demonstrating important electron-phonon coupling effects in the GHz frequency domain, shows that information on deep interface electrons can be obtained by tuning the penetration depth of optically-generated surface phonons so as to selectively probe the interface region, as in a sort of quantum sonar.

A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. Our theoretical result agrees well with previous experimental data.

Infectious bursal disease virus (IBDV) is a highly contagious disease that results in enormous economic losses in the global poultry sector. Lactic acid bacteria are an appealing vehicle for the safe and effective delivery of heterologous protein antigens. Oral administration of the commensal bacterium Lactococcus lactis expressing recombinant fusion proteins has been used to elicit mucosal and systemic immune responses. In this study, a Lactococcus lactis NZ3900 strain co-expressing the outer membrane protein (Omp) H of the microfold (M) cell-targeting ligand and the viral capsid protein (VP)2 antigen of IBDV was genetically engineered, and its immunopotentiating capacity as an oral and injected vaccine in chickens was evaluated. Western blotting analysis demonstrated that VP2-OmpH was expressed in the cytoplasm of cells and had high immunoreactivity. An in vivo study showed that in the absence of any adjuvant, the recombinant L. lactis VP2-OmpH strain stimulated the immune response and protected against very virulent IBDV challenge in 100% and 80% of chickens immunized by injection and oral administration, respectively. Moreover, the antiviral neutralizing antibody titers induced by injection administration were higher than those induced by oral administration. Mucosal secretory IgA titers induced by oral administration were higher than those induced by injection administration. These results suggested that the recombinant L. lactis VP2-OmpH strain is a promising candidate vaccine to prevent IBDV infection.

A dual-nanowire heterostructure with a GeSn layer laterally laying on Ge nanowires is demonstrated by MBE. The strain field analyzed by FEM shows that the novel proposal can significantly release the compressive strain in GeSn for potential direct bandgap conversion as a Si-based light source.

In this paper, we present electrically pumped GaAsBi quantum well (QW) laser diodes (LDs) grown by molecular beam epitaxy. The LDs reveal a record long lasing wavelength of 1.14 µm at 300 K and can be operated under CW excitation up to 273 K. They also show high performance with an internal quantum efficiency of 86% and an internal optical loss of 10 cm−1. The characteristic temperature is 79 K in the temperature range of 225–350 K and the temperature coefficient of the lasing wavelength is 0.26 nm/K at 77 – 350 K, much smaller than 0.35 – 0.40 nm/K for InGaAs and InGaAsP QW LDs. These results suggest that GaAsBi LDs are attractive candidates for uncooled near infrared lasers on GaAs.

Single-marker genome-wide association study (GWAS) is a convenient strategy of genetic analysis that has been successful in detecting the association of a number of single-nucleotide polymorphisms (SNPs) with quantitative traits. However, analysis of individual SNPs can only account for a small proportion of genetic variation and offers only limited knowledge of complex traits. This inadequacy may be overcome by employing a gene-based GWAS analytic approach, which can be considered complementary to the single-SNP association analysis. Here we performed an initial single-SNP GWAS for bone weight (BW) and meat pH value with a total of 770,000 SNPs in 1141 Simmental cattle. Additionally, 21836 cattle genes collected from the Ensembl Genes 83 database were analyzed to find supplementary evidence to support the importance of gene-based association study. Results of the single SNP-based association study showed that there were 11 SNPs significantly associated with bone weight (BW) and two SNPs associated with meat pH value. Interestingly, all of these SNPs were located in genes detected by the gene-based association study.

The nanoscale distribution of Bi in InPBi is determined by atom probe tomography and transmission electron microscopy. The distribution of Bi atoms is not uniform both along the growth direction and within the film plane. A statistically high Bi-content region is observed at the bottom of the InPBi layer close to the InPBi/InP interface. Bi-rich V-shaped walls on the (−111) and (1–11) planes close to the InPBi/InP interface and quasi-periodic Bi-rich nanowalls in the (1–10) plane with a periodicity of about 100 nm are observed. A growth model is proposed to explain the formation of these unique Bi-related nanoscale features. These features can significantly affect the deep levels of the InPBi epilayer. The regions in the InPBi layer with or without these Bi-related nanostructures exhibit different optical properties.

Structural and electronic properties of two-dimensional stanene and graphene heterostructure (Sn/G) are studied by using first-principles calculations. Various supercell models are constructed in order to reduce the strain induced by the lattice mismatch. The results show that stanene interacts overall weakly with graphene via van der Waals (vdW) interactions. Multiple phases of different crystalline orientation of stanene and graphene could coexist at room temperature. Moreover, interlayer interactions in stanene and graphene heterostructure can induce tunable band gaps at stanene’s Dirac point, and weak p-type and n-type doping of stanene and graphene, respectively, generating a small amount of electron transfer from stanene to graphene. Interestingly, for model \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathrm{S}\mathrm{n}\left(\sqrt{7}\right)/\mathrm{G}(5) $$\end{document}Sn7/G5 , there emerges a band gap about 34 meV overall the band structure, indicating it shows semiconductor feature.

Photoluminescence (PL) study is conducted on InAs films molecular beam epitaxially grown on GaAs substrates with different Bi flux levels. A PL peak blueshift accompanied by linewidth broadening is found with the increase of Bi/As flux ratio, in contrast to the common Bi isoelectronic incorporation or surfactant effect. It is, with detailed lineshape analysis and the evidence of PL peak splitting in a magnetic filed, attributed to the electron concentration enhancement induced by Bi flux. The electron concentration in InAs film is evaluated, which is about 5-fold enhanced as Bi/As flux ratio rises up from 0 to 1x10(-3). The temperature dependence of the PL spectrum indicates that the carrier redistribution augments while the carrier-phonon Frohlich scattering weakens in InAs films with high Bi/As flux ratios. These findings reveal a novel Bi effect of electron concentration enhancement, and contribute to the basic knowledge of Bi in III-V semiconductors.

Intermediate band solar cells have attracted significant interest as a possible means of achieving high conversion efficiency. Under optimized growth parameters, we successfully achieve a high density of uniform InAs QDs grown on various matrixes by molecular beam epitaxy. Incorporating N atoms into GaAs and AlGaAs barriers effectively compensates the internal compressive strain and avoids formation of dislocations and defects. The 50 stacking of high density and uniform InAs QDs was demonstrated without detectable dislocations using 26 nm GaNAs as a barrier.

InAs/GaSb type-II superlattce (T2SL) photodetector structures at the MWIR regime were grown by molecular beam epitaxy. The growth temperature and group-V soaking times were optimized with respect to interface and transport quality. Novel strain compensation schemes with insertion of InSb layers were proposed and tested to be efficient to tune the overall strain between tensile and compressive without degradation of interface and optical quality. The effect of the proposed methods is modeled by analytic functions. Band structure calculations were also carried out for the proposed T2SL structures to assist optimizing sample designs. Single pixel photodiodes with a low dark current were demonstrated.

This study proposes an ablation enhancement approach to fabricate microgrooves in PMMA by femtosecond laser irradiation assisted with a microtorch. The influences of pulse energy and scanning speed on the groove depth and removal area of groove are investigated. It is demonstrated that the improvement of groove depth has a close relationship with the scanning speed. When the scanning speed was less than 50 µm/s, the ablated groove depth is considerably improved with various pulse energies, up to 100 %. Moreover, the removal area of groove has significant enhancements of up to 250 % in various processing parameters. It is suggested that the ablation enhancement of microgrooves fabrication is related to the status of plasma plume and substrate heating. With the assistance of the microtorch, laser-induced plasma plume is confined and its density at center region is raised, which results in the increment of the central plasma’s temperature and more energy deposited on the PMMA surface, ultimately leading to the ablation enhancement. Meanwhile, the instantaneous substrate heating also plays a crucial role on enhanced microgrooves fabrication.