141 research outputs found

    Understanding oxygen anionic-electronic defects under high electric fields: Resistive switches devices

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    Nanoscale resistive switches (ReRAMs) were recently proposed as new class of non-volatile memories by switching non-linearly between low- and high-resistance values through application of voltage pulses in the ns-range. Through this paper we firstly introduce the topic of resistive switching oxides under high electric fields, their charge transport mechanism and often named memristive characteristics; and critically address open questions. In the second part we turn, to innovative new approaches in making of doped oxides and interface designs to novel device structures for oxide-based switches based on own results: Here, we will firstly discuss a mixed anionic electronic conductor model experiment, being a Gd-doped ceria series with tuned doping concentration to affect the defect association and mobility of the oxide switching bits in a systematic manner. We find a clear correlation between concentration and mobility of oxygen ionic carriers and resistive switching response, and discuss those down to the changes in the near order structures connected therein. Secondly, we exemplify the switching characteristics based on either compressively or tensely strained Gd0.1Ce0.9O2-x heterostructures modulated by Er2O3 or Sm2O3 layers, respectively, and discuss directly the device implication. Thereby, we present a new type of a model material device concept entitled a strained ReRAM . Here, new material engineering of oxides beyond doping is discussed to control resistive switching device properties like retention, Roff/Ron ratios and power consumption by interfacial strain engineering of mixed conducting oxide . Thirdly, we grow nanoscopically-flat LaFeO3 switching bits and demonstrate in a model experiment for amorphous and epitaxially grown films the implication of grain-boundary free but varying defect levels of the structures on resistive switching. Fourthly, we turn to the role of electric field and frequency dependencies of SrTiO3-based ReRAMs. Here, electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry are used to investigate optimum operation concerning fast switching and stable retention with high resistance modulation. We show that two different switching mechanisms can be individually addressed depending on electric field strength and switching times. The Memristor-based Cottrell analysis is used to successfully determine diffusion constant characteristics of the materials and separating capacitive and memristive contributions. Finally, we conclude on the role of oxygen anionic-electronic carriers and transfer for oxide-based switches, and discuss the applicability for bits and circuits of potential memory and logic applications. References S. Schweiger, M. Kubicek, F. Messerschmitt, C. Murer, J.L.M. Rupp, ACS Nano, 8, 5, 5032, 2014. F. Messerschmitt, M. Kubicek, S. Schweiger, J.L.M. Rupp, Adv. Funct. Mater. 24, 47, 7448, 2014. F. Messerschmitt, M. Kubicek, J.L.M. Rupp, Adv. Funct. Mater. 25, 32, 5117, 2015. M. Kubicek, R. Schmitt, F. Messerschmitt, J.L.M. Rupp ACS Nano, 9, 11, 10737, 201

    Identification of importin (IPO-8) as the most accurate reference gene for the clinicopathological analysis of lung specimens

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    Abstract Background: The accurate normalization of differentially expressed genes in lung cancer is essential for the identification of novel therapeutic targets and biomarkers by real time RT-PCR and microarrays. Although classical "housekeeping" genes, such as GAPDH, HPRT1, and beta-actin have been widely used in the past, their accuracy as reference genes for lung tissues has not been proven. Results: We have conducted a thorough analysis of a panel of 16 candidate reference genes for lung specimens and lung cell lines. Gene expression was measured by quantitative real time RTPCR and expression stability was analyzed with the softwares GeNorm and NormFinder, mean of |ΔCt| (= |Ct Normal-Ct tumor|) ± SEM, and correlation coefficients among genes. Systematic comparison between candidates led us to the identification of a subset of suitable reference genes for clinical samples: IPO8, ACTB, POLR2A, 18S, and PPIA. Further analysis showed that IPO8 had a very low mean of |ΔCt| (0.70 ± 0.09), with no statistically significant differences between normal and malignant samples and with excellent expression stability. Conclusion: Our data show that IPO8 is the most accurate reference gene for clinical lung specimens. In addition, we demonstrate that the commonly used genes GAPDH and HPRT1 are inappropriate to normalize data derived from lung biopsies, although they are suitable as reference genes for lung cell lines. We thus propose IPO8 as a novel reference gene for lung cancer samples

    Development of a novel splice array platform and its application in the identification of alternative splice variants in lung cancer

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    Abstract Background Microarrays strategies, which allow for the characterization of thousands of alternative splice forms in a single test, can be applied to identify differential alternative splicing events. In this study, a novel splice array approach was developed, including the design of a high-density oligonucleotide array, a labeling procedure, and an algorithm to identify splice events. Results The array consisted of exon probes and thermodynamically balanced junction probes. Suboptimal probes were tagged and considered in the final analysis. An unbiased labeling protocol was developed using random primers. The algorithm used to distinguish changes in expression from changes in splicing was calibrated using internal non-spliced control sequences. The performance of this splice array was validated with artificial constructs for CDC6, VEGF, and PCBP4 isoforms. The platform was then applied to the analysis of differential splice forms in lung cancer samples compared to matched normal lung tissue. Overexpression of splice isoforms was identified for genes encoding CEACAM1, FHL-1, MLPH, and SUSD2. None of these splicing isoforms had been previously associated with lung cancer. Conclusions This methodology enables the detection of alternative splicing events in complex biological samples, providing a powerful tool to identify novel diagnostic and prognostic biomarkers for cancer and other pathologies

    E-retailing ethics in Egypt and its effect on customer repurchase intention

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    The theoretical understanding of online shopping behaviour has received much attention. Less focus has been given to the formation of the ethical issues that result from online shopper interactions with e-retailers. The vast majority of earlier research on this area is conceptual in nature and limited in scope by focusing on consumers’ privacy issues. Therefore, the purpose of this paper is to propose a theoretical model explaining what factors contribute to online retailing ethics and its effect on customer repurchase intention. The data were analysed using variance-based structural equation modelling, employing partial least squares regression. Findings indicate that the five factors of the online retailing ethics (security, privacy, non- deception, fulfilment/reliability, and corporate social responsibility) are strongly predictive of online consumers’ repurchase intention. The results offer important implications for e-retailers and are likely to stimulate further research in the area of e-ethics from the consumers’ perspective

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci.

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    Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity

    Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

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    International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes

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    This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.Cardiolog
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