344 research outputs found

    Charge Transfer Induced Molecular Hole Doping into Thin Film of Metal-Organic-Frameworks

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    Despite the highly porous nature with significantly large surface area, metal organic frameworks (MOFs) can be hardly used in electronic, and optoelectronic devices due to their extremely poor electrical conductivity. Therefore, the study of MOF thin films that require electron transport or conductivity in combination with the everlasting porosity is highly desirable. In the present work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity are synthesized using layer-by-layer and doctor blade coating techniques followed by iodine doping. The as-prepared and doped films are characterized using FE-SEM, EDX, UV/Visible spectroscopy, XPS, current-voltage measurement, photoluminescence spectroscopy, cyclic voltammetry, and incident photon to current efficiency measurements. In addition, the electronic and semiconductor property of the MOF films are characterized using Hall Effect measurement, which reveals that in contrast to the insulator behavior of the as-prepared MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by charge transfer induced hole doping into the frameworks. The observed charge transfer induced hole doping phenomenon is also confirmed by calculating the densities of states of the as-prepared and iodine doped MOFs based on density functional theory. Photoluminescence spectroscopy demonstrate an efficient interfacial charge transfer between TiO2 and iodine doped MOFs, which can be applied to harvest solar radiations.Comment: Main paper (19 pages, 6 figures) and supplementary information (15 pages, 10 figures), accepted in ACS Appl. Materials & Interface

    Enhanced Generative Adversarial Networks for Unseen Word Generation from EEG Signals

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    Recent advances in brain-computer interface (BCI) technology, particularly based on generative adversarial networks (GAN), have shown great promise for improving decoding performance for BCI. Within the realm of Brain-Computer Interfaces (BCI), GANs find application in addressing many areas. They serve as a valuable tool for data augmentation, which can solve the challenge of limited data availability, and synthesis, effectively expanding the dataset and creating novel data formats, thus enhancing the robustness and adaptability of BCI systems. Research in speech-related paradigms has significantly expanded, with a critical impact on the advancement of assistive technologies and communication support for individuals with speech impairments. In this study, GANs were investigated, particularly for the BCI field, and applied to generate text from EEG signals. The GANs could generalize all subjects and decode unseen words, indicating its ability to capture underlying speech patterns consistent across different individuals. The method has practical applications in neural signal-based speech recognition systems and communication aids for individuals with speech difficulties.Comment: 5 pages, 2 figure

    Primary Acinic Cell Carcinoma of the Breast: A Case Report with an Immunohistochemical and Ultrastructural Studies

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    Acinic cell carcinoma (ACC) of the breast is extremely rare and is characterized by widespread acinar cell-like differentiation. We report of a 39-year-old woman presented with a palpable breast mass with significant morphological, immunohistochemical and ultrastructural findings. Histologically, ACC showed a diffuse glandular infiltrative pattern, with small acinar or glandular structures mixed with solid nests. Neoplastic cells were monotonous proliferation of cells with a granular or clear cytoplasm, resembling acinar cells of the salivary glands or Paneth cells. Both glandular and solid tumor cell populations were strongly positive for lysozyme and α-1-antitrypsin

    Characteristics of Soil Heavy Metal Contamination in the Intensive Livestock Farming Watersheds

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    Soil contamination of agricultural watersheds can increase to deteriorate water quality, human health, crop production and aquatic ecology. In particular, it is important to understand the impacts of soil heavy metal contamination from livestock excretion because the excretion has been gradually increasing due to the rapid growth of the livestock industry. In this study, to analyze the characteristics of soil heavy metal contamination in intensive livestock farming watersheds, we selected intensive livestock farming watersheds where livestock heads and amount of livestock excretion by species were spatiotemporally surveyed. We also investigated the characteristics of five soil heavy metals (As, Cd, Pb, Cu, Zn) contamination. The Cheongmi Stream watershed in Anseong, Kyungi-do and Gwangcheon Stream watershed in Hongseong, Chungcheongbuk-do, Korea were one of the most intensive livestock rearing regions where there were very large amounts of livestock excretion. It was also found that Cu and Zn among heavy metals exceeded the soil contamination concern standard at two of the sampling points in the Gwangcheon Stream watershed. Compared to the national soil measurement network data, it was showed that the concentrations of Cd, Cu, and Zn in the intensive livestock farming areas such as both Cheongmi Stream and Gwangcheon Stream watersheds were higher than in other areas. Thus, we suggested that the soil in intensive farming watersheds was contaminated by heavy metals compared to other areas. Therefore, it is necessary to manage not only livestock excretion, but also animals’ welfare, humans, and the environment to use less heavy metals in their feeds. We also believed that various impacts of livestock excretion on the environment need to be studied soon

    Parenchymal Neurocutaneous Melanosis in Association with Intraventricular Dermoid and Dandy-Walker Variant: A Case Report

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    Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation

    Molecular genetic study of novel biomarkers for early diagnosis of oral squamous cell carcinoma

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    Objectives: Early detection and treatment of an oral squamous cell carcinoma (OSCC) is critical because of its rapid growth, frequent lymph-node metastasis, and poor prognosis. However, no clinically-valuable methods of early diagnosis exist, and genetic analysis of OSCCs has yielded no biomarkers. Study D esign: We investigated the expression of genes associated with inflammation in OSCCs via a quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of microarray data. Tumor and normal tissues from five patients with an OSCC were used for microarray analysis. Differentially-expressed genes, identified using permutation, local pooled error (LPE), t-tests, and significance analysis of microarrays (SAM), were selected as candidate genetic markers. Results: Two groups corresponding to tissue identity were evident, implying that their differentially-expressed genes represented biological differences between tissues. Fifteen genes were identified using the Student’s paired t-test ( p< 0.05) and the SAM, with a false discovery rate of less than 0.02. Based on gene expression, these 15 genes can be used to classify an OSCC. A genetic analysis of functional networks and ontologies, validated by using a qRT-PCR analysis of the tissue samples, identified four genes, ADAM15, CDC7, IL12RB2 and TNFRSF8, that demonstrated excellent concordance with the microarray data. Conclusions: Our study demonstrated that four genes (ADAM15, CDC7, IL12RB2 and TNFRSF8) had potential as novel biomarkers for the diagnosis and the treatment of an OSCC

    Signaling Events During Induction of Plasminogen Activator Inhibitor-1 Expression by Sphingosylphosphorylcholine in Cultured Human Dermal Fibroblasts

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    Sphingosylphosphorylcholine (SPC) is a bioactive sphingolipid metabolite that can enhance wound healing. In a search for effectors downstream of SPC in the wound-healing process, we found that the expression of the gene for plasminogen activator inhibitor-1 (PAI-1) was significantly affected. ELISA and western blot analyses showed that SPC markedly induced PAI-1 production in human dermal fibroblasts cultured in vitro. Inhibition by pre-treatment with pertussis toxin (PTx), but not by tyrphostin A47 (a receptor tyrosine kinase inhibitor), indicated that PTx-sensitive G proteins were involved in SPC-induced PAI-1 expression. SPC elicited a rapid and transient increase in intracellular calcium levels ([Ca2+]i), measured using laser scanning confocal microscopy, which was partly mediated through PTx-sensitive G proteins. Pre-treatment with thapsigargin, but not with EGTA, abolished SPC-induced PAI-1 expression, indicating the importance of Ca2+ release from internal stores. Phorbol-12-myristate-13-acetate (PMA) induced the expression of PAI-1, and pre-treatment with Ro 31-8220 (a PKC inhibitor) markedly suppressed SPC-induced PAI-1 expression. SPC-induced PAI-1 expression was also significantly suppressed by PD98059 (a specific MAPK kinase 1/2 inhibitor). Consistent with this result, SPC stimulated the phosphorylation of p42/44 extracellular signal-regulated kinase (ERK). Together, these results suggest that SPC induces PAI-1 production through a G protein-coupled calcium increase and downstream kinase signaling events in cultured human dermal fibroblasts
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