577 research outputs found

    Optical property and Stokes' shift of Zn <inf>1-x</inf>Cd <inf>x</inf>O thin films depending on Cd content

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    Ternary Zn1-x Cdx O films were grown on (0001) sapphire substrates by pulsed laser deposition. The energy band gap of Zn1-x Cdx O films decreases with increasing Cd content. An increase of Cd content also leads to the emission broadening, absorption edge broadening, and crystallinity degradation. The absorption edge and ultraviolet emission energy shift to lower energy from 3.357 eV to 3.295 eV and 3.338 eV to 3.157 eV, respectively, with increasing Cd content from 0.3% to 3% at 4 K. The Stokes' shift between the absorption and emission is observed and that indicates the increase of exciton localization with Cd content. © 2006 American Institute of Physics

    Optimizing ET-based irrigation scheduling for wheat and maize with water constraints

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    © 2017 American Society of Agricultural and Biological Engineers. Deficit irrigation has been shown to increase crop water use efficiency (WUE) under certain conditions, even though the yield is slightly reduced. In this study, the Root Zone Water Quality Model (RZWQM) was first calibrated with measured data from a large weighing lysimeter from 1998 to 2003 at the Yucheng Experimental Station in the North China Plain for daily evapotranspiration (ET), soil water storage (0-120 cm), leaf area index (LAI), aboveground biomass, and grain yield. The calibrated model was then used to explore crop responses to ET-based irrigation management using weather data from 1958 to 2015 and identify the most suitable ET-based irrigation schedules for the area. Irrigation amount was determined by constraining irrigation to a percentage of potential crop ET (40%, 60%, 80%, and 100% ETc) at the various growth stages of wheat [planting to before winter dormancy (P-D), green up to booting (G-B), booting to flowering (B-F), and flowering to maturity (F-M)] and of maize [planting to silking (P-S) and silking to maturity (S-M)], subject to seasonal water availability limits of 100/50, 200/100, 300/150, and 400/200 mm and no water limit for wheat/maize seasons, respectively. In general, wheat was more responsive to irrigation than maize, while greater influence of weather variation was simulated on maize than on wheat. For wheat with seasonal water limits, the highest average WUE was simulated with the highest targeted ETc levels at both the G-B and B-F stages and lower targeted ETc levels at the P-D and F-M stages. However, the highest average grain yield was simulated with the highest targeted ETc levels at all four growth stages for no water limit and the 400 mm water limit, or at both the G-B and B-F stages for the 300 and 200 mm water limits. For maize, lower targeted ETc levels after silking did not significantly affect maize production due to the high season rainfall, but irrigation of 60% ETc before silking was recommended. These results could be used as guidelines for precision irrigation along with real-time weather information

    Mutant INS-Gene Induced Diabetes of Youth: Proinsulin Cysteine Residues Impose Dominant-Negative Inhibition on Wild-Type Proinsulin Transport

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    Recently, a syndrome of Mutant INS-gene-induced Diabetes of Youth (MIDY, derived from one of 26 distinct mutations) has been identified as a cause of insulin-deficient diabetes, resulting from expression of a misfolded mutant proinsulin protein in the endoplasmic reticulum (ER) of insulin-producing pancreatic beta cells. Genetic deletion of one, two, or even three alleles encoding insulin in mice does not necessarily lead to diabetes. Yet MIDY patients are INS-gene heterozygotes; inheritance of even one MIDY allele, causes diabetes. Although a favored explanation for the onset of diabetes is that insurmountable ER stress and ER stress response from the mutant proinsulin causes a net loss of beta cells, in this report we present three surprising and interlinked discoveries. First, in the presence of MIDY mutants, an increased fraction of wild-type proinsulin becomes recruited into nonnative disulfide-linked protein complexes. Second, regardless of whether MIDY mutations result in the loss, or creation, of an extra unpaired cysteine within proinsulin, Cys residues in the mutant protein are nevertheless essential in causing intracellular entrapment of co-expressed wild-type proinsulin, blocking insulin production. Third, while each of the MIDY mutants induces ER stress and ER stress response; ER stress and ER stress response alone appear insufficient to account for blockade of wild-type proinsulin. While there is general agreement that ultimately, as diabetes progresses, a significant loss of beta cell mass occurs, the early events described herein precede cell death and loss of beta cell mass. We conclude that the molecular pathogenesis of MIDY is initiated by perturbation of the disulfide-coupled folding pathway of wild-type proinsulin

    Ni–Al diffusion barrier layer for integrating ferroelectric capacitors on Si

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    2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Cardio-Protection of Salvianolic Acid B through Inhibition of Apoptosis Network

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    Targeting cellular function as a system rather than on the level of the single target significantly increases therapeutic potency. In the present study, we detect the target pathway of salvianolic acid B (SalB) in vivo. Acute myocardial infarction (AMI) was induced in rats followed by the treatment with 10 mg/kg SalB. Hemodynamic detection and pathological stain, 2-dimensional electrophoresis, MALDI-TOF MS/MS, Western blot, pathway identification, apoptosis assay and transmission electron microscope were used to elucidate the effects and mechanism of SalB on cardioprotection. Higher SalB concentration was found in ischemic area compared to no-ischemic area of heart, correlating with improved heart function and histological structure. Thirty-three proteins regulated by SalB in AMI rats were identified by biochemical analysis and were classified as the components of metabolism and apoptosis networks. SalB protected cardiomyocytes from apoptosis, inhibited poly (ADP-ribose) polymerase-1 pathway, and improved the integrity of mitochondrial and nucleus of heart tissue during AMI. Furthermore, the protective effects of SalB against apoptosis were verified in H9c2 cells. Our results provide evidence that SalB regulates multi-targets involved in the apoptosis pathway during AMI and therefore may be a candidate for novel therapeutics of heart diseases

    White Electroluminescence Using ZnO Nanotubes/GaN Heterostructure Light-Emitting Diode

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    We report the fabrication of heterostructure white light–emitting diode (LED) comprised of n-ZnO nanotubes (NTs) aqueous chemically synthesized on p-GaN substrate. Room temperature electroluminescence (EL) of the LED demonstrates strong broadband white emission spectrum consisting of predominating peak centred at 560 nm and relatively weak violet–blue emission peak at 450 nm under forward bias. The broadband EL emission covering the whole visible spectrum has been attributed to the large surface area and high surface states of ZnO NTs produced during the etching process. In addition, comparison of the EL emission colour quality shows that ZnO nanotubes have much better quality than that of the ZnO nanorods. The colour-rendering index of the white light obtained from the nanotubes was 87, while the nanorods-based LED emit yellowish colour

    Molecular Dynamics Simulations of the Roller Nanoimprint Process: Adhesion and Other Mechanical Characteristics

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    Molecular dynamics simulations using tight-binding many body potential are carried out to study the roller imprint process of a gold single crystal. The effect of the roller tooth’s taper angle, imprint depth, imprint temperature, and imprint direction on the imprint force, adhesion, stress distribution, and strain are investigated. A two-stage roller imprint process was obtained from an imprint force curve. The two-stage imprint process included the imprint forming with a rapid increase of imprint force and the unloading stage combined with the adhesion stage. The results show that the imprint force and adhesion rapidly increase with decreasing taper angle and increasing imprint depth. The magnitude of the maximum imprint force and the time at which this maximum occurs are proportional to the imprint depth, but independent of the taper angle. In a comparison of the imprint mechanisms with a vertical imprint case, while high stress and strain regions are concentrated below the mold for vertical imprint, they also occur around the mold in the case of roller imprint. The regions were only concentrated on the substrate atoms underneath the mold in vertical imprint. Plastic flow increased with increasing imprint temperature

    Differential Proteomic Analysis of Platelets Suggested Possible Signal Cascades Network in Platelets Treated with Salvianolic Acid B

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    Salvianolic acid B (SB) is an active component isolated from Danshen, a traditional Chinese medicine widely used for the treatment of cardiovascular disorders. Previous study suggested that SB might inhibit adhesion as well as aggregation of platelets by a mechanism involving the integrin α2β1. But, the signal cascades in platelets after SB binding are still not clear.In the present study, a differential proteomic analysis (two-dimensional electrophoresis) was conducted to check the protein expression profiles of rat platelets with or without treatment of SB. Proteins altered in level after SB exposure were identified by MALDI-TOF MS/MS. Treatment of SB caused regulation of 20 proteins such as heat shock-related 70 kDa protein 2 (hsp70), LIM domain protein CLP-36, copine I, peroxiredoxin-2, coronin-1 B and cytoplasmic dynein intermediate chain 2C. The regulation of SB on protein levels was confirmed by Western blotting. The signal cascades network induced by SB after its binding with integrin α2β1 was predicted. To certify the predicted network, binding affinity of SB to integrin α2β1 was checked in vitro and ex vivo in platelets. Furthermore, the effects of SB on protein levels of hsp70, coronin-1B and intracellular levels of Ca²+ and reactive oxygen species (ROS) were checked with or without pre-treatment of platelets using antibody against integrin α2β1. Electron microscopy study confirmed that SB affected cytoskeleton structure of platelets.Integrin α2β1 might be one of the direct target proteins of SB in platelets. The signal cascades network of SB after binding with integrin α2β1 might include regulation of intracellular Ca²+ level, cytoskeleton-related proteins such as coronin-1B and cytoskeleton structure of platelets

    Self-Cleaning Glass of Photocatalytic Anatase TiO2@Carbon Nanotubes Thin Film by Polymer-Assisted Approach

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    Due to the good photocatalytic activity, the TiO2@CNTs thin film is highly desirable to apply to the self-cleaning glass for green intelligent building. Here, the TiO2@CNTs thin film has been successfully achieved by polymer-assisted approach of an aqueous chemical solution method. The polymer, polyethylenimine, aims to combine the Ti4+ with CNTs for film formation of TiO2@CNTs. The resultant thin film was uniform, highly transparent, and super-hydrophilic. Owing to fast electron transport and effectively hindering electron-hole recombination, the TiO2@CNTs thin film has nearly twofold photocatalytic performance than pure TiO2. The TiO2@CNTs thin films show a good application for self-cleaning glasses

    A Combined Approach of High-Throughput Sequencing and Degradome Analysis Reveals Tissue Specific Expression of MicroRNAs and Their Targets in Cucumber

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    MicroRNAs (miRNAs) are endogenous small RNAs playing an important regulatory function in plant development and stress responses. Among them, some are evolutionally conserved in plant and others are only expressed in certain species, tissue or developmental stages. Cucumber is among the most important greenhouse species in the world, but only a limited number of miRNAs from cucumber have been identified and the experimental validation of the related miRNA targets is still lacking. In this study, two independent small RNA libraries from cucumber leaves and roots were constructed, respectively, and sequenced with the high-throughput Illumina Solexa system. Based on sequence similarity and hairpin structure prediction, a total of 29 known miRNA families and 2 novel miRNA families containing a total of 64 miRNA were identified. QRT-PCR analysis revealed that some of the cucumber miRNAs were preferentially expressed in certain tissues. With the recently developed ‘high throughput degradome sequencing’ approach, 21 target mRNAs of known miRNAs were identified for the first time in cucumber. These targets were associated with development, reactive oxygen species scavenging, signaling transduction and transcriptional regulation. Our study provides an overview of miRNA expression profile and interaction between miRNA and target, which will help further understanding of the important roles of miRNAs in cucumber plants
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