85 research outputs found

    Polymer Electret Improves the Performance of the Oxygen-Doped Organic Field-Effect Transistors

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    Chemical doping is widely used in the electronic devices. In p-type semiconductor thin films, oxygen doping fills the hole traps and increases hole concentrations, improving the performance of the organic field-effect transistors (OFETs). Due to the low ionization potential for p-type semiconductors, the superfluous holes induced by the oxygen doping degrades the OFETs off-state leakage performance. On the other hand, for p-type semiconductors with high ionization potential (up to 5.5-6.0 eV), the limited oxidation of oxygen is hard to achieve satisfactory doping concentrations to fill the trap states. This refers to the well-known intrinsic incompatibility between the oxygen doping and high-performance OFETs. Herein, a novel strategy is introduced to overcome the incompatibility and achieve high-performance OFETs by using the structural polymer electret. That is, moderate hole concentrations induced by low-pressure (30 Pa) oxygen plasma fill the hole traps within semiconductor. And the built-in field resulted from polymer electret accumulates the holes inside semiconductor near the semiconductor/electret interface, thus improving the OFETs performance. Using a model organic semiconductor with high ionization potential-2,7-didodecyl[1]benzothieno [3,2-b][1]benzothiophene (C12-BTBT) as an example, the high-performance OFETs with field-effect mobility (μFET) of 3.5 cm 2 V -1 s -1 , subthreshold-swing (SS) of 110 mV decade -1 , on-off ratio of 10 4 , and widely-tunable threshold voltage (V t ) are realized at a low voltage below 2 V in the open air

    Synthesis, biological evaluation and mechanism studies of C-23 modified 23-hydroxybetulinic acid derivatives as anticancer agents

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    A series of C-23 modified 23-hydroxybetulinic acid (HBA) derivatives were synthesized and evaluated for their antiproliferative activity against a panel of cancer cell lines (A2780, A375, B16, MCF-7 and HepG2). The biological screening results showed that most of the derivatives exhibited more potent antiproliferative activity than HBA, and compound 6e exhibited the most potent activity with IC50 values of 2.14 μM, 2.89 μM, and 3.97 μM against A2780, B16, and MCF-7 cells, respectively. Further anticancer mechanism studies revealed that compound 6e induced the generation of intracellular reactive oxygen species (ROS) and reduction of mitochondrial membrane potential (MMP) of B16 cells in a dose-dependent manner. Moreover, western blot analysis indicated that compound 6e downregulated the expression of anti-apoptotic protein Bcl-2 and upregulated the expression of proapoptotic protein Bax, activation of caspase 3 to induce cell apoptosis. Meanwhile, compound 6e significantly inhibited the phosphorylation of MEK, ERK, and Akt without affecting the expression of MEK, ERK, and Akt. Furthermore, the in vivo anti-tumor activity of 6e was validated (tumor inhibitory ratio of 68.4% at the dose of 30 mg/kg) in mice with B16 melanoma

    Genome-Wide Transcriptome and Antioxidant Analyses on Gamma-Irradiated Phases of Deinococcus radiodurans R1

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    Adaptation of D. radiodurans cells to extreme irradiation environments requires dynamic interactions between gene expression and metabolic regulatory networks, but studies typically address only a single layer of regulation during the recovery period after irradiation. Dynamic transcriptome analysis of D. radiodurans cells using strand-specific RNA sequencing (ssRNA-seq), combined with LC-MS based metabolite analysis, allowed an estimate of the immediate expression pattern of genes and antioxidants in response to irradiation. Transcriptome dynamics were examined in cells by ssRNA-seq covering its predicted genes. Of the 144 non-coding RNAs that were annotated, 49 of these were transfer RNAs and 95 were putative novel antisense RNAs. Genes differentially expressed during irradiation and recovery included those involved in DNA repair, degradation of damaged proteins and tricarboxylic acid (TCA) cycle metabolism. The knockout mutant crtB (phytoene synthase gene) was unable to produce carotenoids, and exhibited a decreased survival rate after irradiation, suggesting a role for these pigments in radiation resistance. Network components identified in this study, including repair and metabolic genes and antioxidants, provided new insights into the complex mechanism of radiation resistance in D. radiodurans

    Design, synthesis and anticancer properties of isocombretapyridines as potent colchicine binding site inhibitors

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    A series of novel isocombretapyridines were designed and synthesized based on a lead compound isocombretastatin A-4 (isoCA-4) by replacing 3,4,5-trimethoxylphenyl with substituent pyridine nucleus. The MTT assay results showed that compound 20a possessed the most potent activities against all tested cell lines with IC50 values at nanomolar concentration ranges. Moreover, 20a inhibited tubulin polymerization at a micromolar level and also displayed potent anti-vascular activity in vitro. Further mechanistic studies were conducted to demonstrate that compound 20a could bind to the colchicine site of tubulin,and disrupte the cell microtubule networks, induce G2/M phase arrest, promote apoptosis and depolarize mitochondria of K562 cells in a dose-dependent manner. Notably, 20a exhibited more potent tumor growth inhibition activity with 68.7% tumor growth inhibition than that of isoCA-4 in H22 allograft mouse model without apparent toxicity. The present results suggested that compound 20a may serve as a promising potent microtubule-destabilizing agent candidate for the development of therapeutics to treat cancer

    Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering

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    This publication is the Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering from July 6-8, 2022. The EG-ICE International Workshop on Intelligent Computing in Engineering brings together international experts working on the interface between advanced computing and modern engineering challenges. Many engineering tasks require open-world resolution of challenges such as supporting multi-actor collaboration, coping with approximate models, providing effective engineer-computer interaction, search in multi-dimensional solution spaces, accommodating uncertainty, including specialist domain knowledge, performing sensor-data interpretation and dealing with incomplete knowledge. While results from computer science provide much initial support for resolution, adaptation is unavoidable and most importantly, feedback from addressing engineering challenges drives fundamental computer-science research. Competence and knowledge transfer goes both ways. &nbsp

    Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering

    Get PDF
    This publication is the Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering from July 6-8, 2022. The EG-ICE International Workshop on Intelligent Computing in Engineering brings together international experts working on the interface between advanced computing and modern engineering challenges. Many engineering tasks require open-world resolution of challenges such as supporting multi-actor collaboration, coping with approximate models, providing effective engineer-computer interaction, search in multi-dimensional solution spaces, accommodating uncertainty, including specialist domain knowledge, performing sensor-data interpretation and dealing with incomplete knowledge. While results from computer science provide much initial support for resolution, adaptation is unavoidable and most importantly, feedback from addressing engineering challenges drives fundamental computer-science research. Competence and knowledge transfer goes both ways. &nbsp

    Estudi i conservació preventiva de les pintures murals de la cova 87 de les Coves de Mogao, Dunhuang (China).

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    [ES] Las cuevas de Mogao, en Dunhuang (China), son las grutas más extensas y ricamente tematizadas del mundo, con gran valor histórico, científico y artístico. En concreto este trabajo se centra en la denominada Cueva 87 del grandioso conjunto de las cuevas de Mogao. Se encuentra en la sección media de la parte sur de las cuevas, al norte del noveno piso, y pertenece a las cuevas de la Dinastía Tang. En este trabajo se ha realizado una evaluación paso a paso del valor de la Cueva 87, se ha llevado a cabo un estudio de su estado actual, un análisis ambiental y también se ha analizado el mecanismo de degradación que ha derivado en las patologías presentes. Además, se ha identificado su entorno de preservación, el estado de conservación, materiales y técnicas de producción. Por último, se plantea una propuesta de intervención y conservación preventiva, partiendo del estudio y análisis del estado actual de las patologías en la Cueva 87 de Mogao. Con la realización de este trabajo, se pretende conseguir una aproximación científica a la obra dentro del campo de la conservación y restauración de pintura mural, concretando la información disponible para asegurar una correcta intervención en el patrimonio.[EN] The Mogao Caves in Dunhuang are the most extensive and richly themed caves in the world, with great historical, scientific and artistic value. Cave 87 of the Mogao Caves is located in the middle section of the southern part of the Mogao Caves, north of the ninth floor, and belongs to the Tang Dynasty caves. In this paper, a step-by-step evaluation of the value of Cave 87, a study of its current state, an analysis of the environmental and the mechanism of the disease are carried out. In addition, it identifies its preservation environment, conservation status, production materials and production techniques. Finally, a proposal for intervention and preventive conservation is proposed based on a study and analysis of the current state of the pathology in Cave 87 of the Mogao Caves. The aim of this work is to achieve a scientific approach to the work within the field of Conservation and Restoration of Mural Painting, specifying the information available to ensure a correct intervention in the Heritage.Lu, S. (2022). Estudio y conservación preventiva de las pinturas murales de la cueva 87 de las cuevas de Mogao, Dunhuang (China). Universitat Politècnica de València. http://hdl.handle.net/10251/184669TFG
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