Preliminary analysis of PGRP-LC gene and structure characteristics in bumblebees

PGRP-LC is a significant pattern recognition receptor of the insect innate immune system that can recognize peptidoglycans and activate immune signaling pathways regulating the expression and release of antimicrobial peptides against infection. We for the first time analyzed the phylogenetic tree, purification and structure of bumblebee PGRP-LC. The results showed high conservation of bumblebee PGRP-LC among the 16 bumblebee species, and further phylogenetic analysis showed that the PGRP-LC phylogeny of different subgenera (Subterraneobombus, Megabombus, Melanobombus, Bombus) is consistent with that of the COI gene. Additionally, the phylogeny of PGRP-LCs among Bombus, Apis and the solitary bee Megachile rotundata coincides with the sociality evolution of bees. Moreover, bumblebee PGRP-LC (Bl-PGRP-LC) shares the Drosophila PGRP-LCx and PGRP-LCa topology, retaining conserved disulfide bonds and 80% binding residues involved in the interaction between TCT and PGRP-LCx. Therefore, Bl-PGRP-LC might share some similar binding characteristics with Drosophila PGRP-LCx. In addition, Bl-PGRP-LC has shorter β5 and β1 sheets, longer β2, β3, and β4 sheets and a shallow binding groove. To determine the characteristics of Bl-PGRP-LC, high-purity PGRP-LC inclusion bodies, soluble GST-tag Bl-PGRP-LC fusion protein and soluble pure Bl-PGRP-LC were obtained in vitro. The results will be helpful for further study of the function and structure of Bl-PGRP-LC

Accurate determination of microparticle size using Fourier transform of light scattering spectrum over wavenumber

© 2007 Optical Society of AmericaThe definitive version of this paper is available at: http://dx.doi.org/10.1364/OL.32.001171DOI: 10.1364/OL.32.001171We discovered that the far-field light scattering spectra of microparticles over wavenumber at a certain angle could be decomposed into periodic components, with an oscillation frequency linearly dependent on the particle size at each angle. Based on this observation, we propose and experimentally demonstrate a new Fourier transform technique for microparticle size determination. This technique is simple, fast, robust in its data processing algorithm, and flexible in its detection system

Two-dimensional electron gas related emissions in ZnMgO/ZnO heterostructures

Radiative recombination of two-dimensional electron gas(2DEG), induced by polarization and validated by Hall effect measurements, is investigated in ZnMgO/ZnO heterostructures grown by metal-organic chemical vapor deposition. The Mg composition, the depth profile distribution of Mg, the residual strain in ZnMgO caplayer, and the thickness of caplayer all significantly influence the 2DEG-related transitions in ZnMgO/ZnO heterostructures. Below or above ZnO donor bound exciton, three additional broad emissions persisting up to 100 K are assigned to the spatially indirect transitions from 2DEG electrons to the photoexcited holes towards the ZnO flat-band region or remaining at the heterointerface.Research is supported by the State Key Program for Basic Research of China under Grant No. 2011CB302003 and National Natural Science Foundation of China (Nos. 61025020 and 60990312)

Temperature-dependent exciton-related transition energies mediated by carrier concentrations in unintentionally Al-doped ZnO films

The authors reported on a carrier-concentration mediation of exciton-related radiative transition energies in Al-doped ZnO films utilizing temperature-dependent (TD) photoluminescence and TD Hall-effect characterizations. The transition energies of free and donor bound excitons consistently change with the measured TD carrier concentrations. Such a carrier-concentration mediation effect can be well described from the view of heavy-doping-induced free-carrier screening and band gap renormalization effects. This study gives an important development to the currently known optical properties of ZnO materials.This research is supported by the State Key Program for Basic Research of China under Grant No. 2011CB302003, National Natural Science Foundation of China (Nos. 61025020, 60990312, and 61274058), Basic Research Program of Jiangsu Province (BK2011437), and the Priority Academic Program Development of Jiangsu Higher Education Institutions

Thermal pretreatment of sapphire substrates prior to ZnO buffer layer growth

The properties of ZnO buffer layers grown via metal-organic chemical vapor deposition (MOCVD) on sapphire substrates after various thermal pretreatments are systematically investigated. High-temperature pretreatments lead to significant modifications of the sapphire surface, which result in enhanced growth nucleation and a consequent improvement of the surface morphology and quality of the ZnO layers. The evolution of the surface morphology as seen by atomic force microscopy indicates an obvious growth mode transition from three-dimensional to quasi-two-dimensional as the pretreatment temperature increases. A minimum surface roughness is obtained when the pretreatment temperature reaches 1150 °C, implying that a high-temperature pretreatment at 1150 °C or above may lead to a conversion of the surface polarity from O-face to Zn-face, similar to processes in GaN material growth via MOCVD. By analyzing the evolution of the film properties as a function of pretreatment temperature, the optimal condition has been determined to be at 1150 °C. This study indicates that a high-temperature pretreatment is crucial to grow high-quality ZnO on sapphire substrates by MOCVD.This research was supported by the State Key Program for Basic Research of China under Grant No. 2011CB302003, National Natural Science Foundation of China (Nos. 61025020, 60990312, and 61274058), Basic Research Program of Jiangsu Province (BK2011437), and the Priority Academic Program Development of Jiangsu Higher Education Institutions

An Integrated Approach for Mining Meta-Rules 1

Abstract: An integrated approach of mining association rules and meta-rules based on a hyper-structure is put forward. In this approach, time serial databases are partitioned according to time segments, and the total number of scanning database is only twice. In the first time, a set of 1-frequent itemsets and its projection database are formed at every partition. Then every projected database is scanned to construct a hyper-structure. Through mining the hyper-structure, various rules, for example, global association rules, meta-rules, stable association rules and trend rules etc. can be obtained. Compared with existing algorithms for mining association rule, our approach can mine and obtain more useful rules. Compared with existing algorithms for meta-mining or change mining, our approach has higher efficiency. The experimental results show that our approach is very promising

Characterization of the parent and hydroxylated polycyclic aromatic hydrocarbons in the soil of the Fildes Peninsula, Antarctica

Polycyclic aromatic hydrocarbons (PAHs) and hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were investigated in the soil of the Fildes Peninsula, Antarctica. Various analytes were detected, and the concentration of OH-PAHs was 0.300–1.847 ng·g−1 dry weight, with the dominant components being danthron and 1-hydroxy-phenanthrene. The relationship between soil total organic matter (TOM), OH-PAHs, and the parent PAHs in the soil was studied. No significant correlation was detected between the spatial distribution of OH-PAHs and the occurrence of PAHs, whereas a positive correlation with TOM was found

Application of Ion Exchange Resin in the Advanced Treatment of Condensate Water

The advanced treatment of condensate water is important for efficient reuse of water resources, especially in confined space. In this work, a novel integrated process of ion exchange resins and activated carbon is proposed to remove various pollutants in condensate water. A fixed bed column of pre-treated basic anion exchange resin, acidic cation exchange resin, mixed ion exchange resins and modified activated carbon was applied to remove ionic pollutants, organic pollutants and adjust the pH value of output water. The effects of the types, amount ratios and the sequence of ion exchange resins were investigated using two types of condensate water. The results showed that the output water of the fixed bed column had an average TOC of 30~70 ppm, conductivity under 5 μS/cm, pH value of 5~8, which could meet the requirements of sanitary water. The saturated adsorption capacities of the basic anion exchange resin and the acidic cation exchange resin were calculated to be 0.87 mol/L and 1.82 mol/L, respectively. Under the actual operating conditions, continuous dynamic test was carried out over a condensate water treatment module consisting of two adsorption columns and four exchange columns to evaluate its real service life

Identification and modulation of electronic band structures of single-phase B-(AlxGa1-x)2O3 alloys grown by laser molecular beam epitaxy

Understanding the band structure evolution of (AlxGa1x)2O3 alloys is of fundamental importance for developing Ga2O3-based power electronic devices and vacuum ultraviolet super-radiation hard detectors. Here, we report on the bandgap engineering of b-(AlxGa1x)2O3 thin films and the identification of compositionally dependent electronic band structures by a combination of absorption spectra analyses and density functional theory calculations. Single-monoclinic b-phase (AlxGa1x)2O3 (0 x 0.54) films with a preferred (201) orientation were grown by laser molecular beam epitaxy with tunable bandgap ranging from 4.5 to 5.5 eV. The excellent fitting of absorption spectra by the relation of (ah) 1/2 / (h-E) unambiguously identifies that b-(AlxGa1x)2O3 alloys are indirect bandgap semiconductors. Theoretical calculations predict that the indirect nature of b-(AlxGa1x)2O3 becomes more pronounced with increased Al composition due to the increased eigenvalue energy gap between M and U points in the valence band. The experimentally determined indirect bandgap exhibits almost a linear relationship with Al composition, which is consistent with the theoretical calculation and indicates a small bowing effect and a good miscibility. The identification and modulation of (AlxGa1x)2O3 band structures allows rational design of ultra-wide bandgap oxide heterostructures for the applications in power electronics and solar-blind or X-ray detection.This research was supported by the National Key Research and Development Project (Grant No. 2017YFB0403003), the National Natural Science Foundation of China (Grant Nos. 61774081, 61322403, and 11227904), the Natural Science Foundation of Jiangsu Province (Grant Nos. BK20130013 and BK20161401), the Six Talent Peaks Project in Jiangsu Province (2014XXRJ001), the Fundamental Research Funds for the Central Universities (021014380093 and 021014380085) and the Australian Research Council. The computational part of this research was undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Government under the NCRIS program