High Performance Organic Transistors for Organic Electronic Applications

Thin-film transistor (TFT) devices using organic semiconducting materials have attracted widespread attentions due to their low cost, flexible form factor, and easy fabrication. However, organic materials’ poor performance as compared to inorganic semiconductor such as silicon limits their applications. Specially, high-frequency operation in organic transistors has never been achieved with organic semiconducting material. One very attractive application for organic electronics is low-cost and flexible Radio Frequency Identification Tag (RFID), which requires relatively high frequency operation. Because of low mobility and high operating bias voltage, the current organic TFT is not appropriate for the most of applications including RFID. The objective of this research is to develop the high performance organic transistor structures which are suitable for organic electronic applications. In designing, two major performance metrics of devices are focused to be improved, which are the on-current level with high on-off ratio and the cutoff frequency of the transistors. They are determined mainly by the carrier mobility, the injection of carrier at the metal/semiconductor boundary, and the passive parasitic components introduced by device geometry. In this study, three new structures are investigated, namely dual-organic layer Metal-Semiconductor Field-Effect Transistor (MESFET), depletion mode organic Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), and organic Heterojunction Bipolar Transistor (HBT). Each of these devices is optimized to enhance the performance of the devices based on comprehensive theoretical modeling, and validated by simulation using TCAD. The devices with channel length of longer than 4 µm exhibit a few µA of on-current and ~10 MHz cutoff frequency. The results obtained in this work show those novel transistor structures can overcome the weakness of conventional organic TFTs and have great potential in realizing organic circuit applications in the future

The Relations of Morphological Awareness with Language and Literacy Skills Vary Depending on Orthographic Depth and Nature of Morphological Awareness

We examined the relation of morphological awareness with language and literacy skills, namely phonological awareness, orthographic awareness, vocabulary, word reading, spelling, text reading fluency, and reading comprehension. We also examined potential moderators of the relations (grade level, orthographic depth of language, receptive vs. productive morphological awareness, inflectional vs. derivational vs. compound morphological awareness, and L1/L2 status). After systematic search, a total of 232 articles (965 unique samples, N = 49,936 participants, and 2,765 effect sizes in 17 languages) met inclusion criteria. Morphological awareness was, on average, moderately related to phonological awareness (r =.41), orthographic awareness (r =.39), vocabulary (r =.50), word reading (r =.49), spelling (r =.48), text reading fluency (r =.53), and reading comprehension (r =.54). Importantly, morphological awareness had a stronger relation with word reading in orthographically deep languages (.52) than in orthographically shallow languages (.38). The relation with vocabulary was stronger for upper elementary grades than for primary grades. The magnitude of the relation also varied by the nature of morphological awareness: productive morphological awareness had a stronger relation with phonological awareness and vocabulary than receptive morphological awareness; derivational morphological awareness had a stronger relation with vocabulary and word reading compared to inflectional morphological awareness; and compound morphological awareness had a weaker relation with phonological awareness but a stronger relation with vocabulary compared to inflectional morphological awareness. These results underscore the importance of morphological awareness in language and literacy skills, and reveal a nuanced and precise picture of their relations

Highly circularly polarized white light using a combination of white polymer light-emitting diode and wideband cholesteric liquid crystal reflector

We present a simple and intriguing device that generates highly circularly polarized white light. It comprises white polymer light-emitting diodes (WPLEDs) attached to a wideband cholesteric liquid crystal (CLC) reflector with a wide photonic bandgap (PBG) covering the visible range. The degree of circular polarization realized is very high over the visible range. The wide PBG was realized by introducing a gradient in pitch of the cholesteric helix by controlling the twisting power within the CLC medium. WPLEDs fabricated using a ternary (red, green, and blue) fluorescent polymer blend with the same moiety showed a low turn-on voltage, high brightness, high efficiency, and good color stability.open0

Graph Anomaly Detection with Graph Neural Networks: Current Status and Challenges

Graphs are used widely to model complex systems, and detecting anomalies in a graph is an important task in the analysis of complex systems. Graph anomalies are patterns in a graph that do not conform to normal patterns expected of the attributes and/or structures of the graph. In recent years, graph neural networks (GNNs) have been studied extensively and have successfully performed difficult machine learning tasks in node classification, link prediction, and graph classification thanks to the highly expressive capability via message passing in effectively learning graph representations. To solve the graph anomaly detection problem, GNN-based methods leverage information about the graph attributes (or features) and/or structures to learn to score anomalies appropriately. In this survey, we review the recent advances made in detecting graph anomalies using GNN models. Specifically, we summarize GNN-based methods according to the graph type (i.e., static and dynamic), the anomaly type (i.e., node, edge, subgraph, and whole graph), and the network architecture (e.g., graph autoencoder, graph convolutional network). To the best of our knowledge, this survey is the first comprehensive review of graph anomaly detection methods based on GNNs.Comment: 9 pages, 2 figures, 1 tables; to appear in the IEEE Access (Please cite our journal version.

Activation of CD147 with Cyclophilin A Induces the Expression of IFITM1 through ERK and PI3K in THP-1 Cells

CD147, as a receptor for Cyclophilins, is a multifunctional transmembrane glycoprotein. In order to identify genes that are induced by activation of CD147, THP-1 cells were stimulated with Cyclophilin A and differentially expressed genes were detected using PCR-based analysis. Interferon-induced transmembrane 1 (IFITM1) was detected to be induced and it was confirmed by RT-PCR and Western blot analysis. CD147-induced expression of IFITM1 was blocked by inhibitors of ERK, PI3K, or NF-κB, but not by inhibitors of p38, JNK, or PKC. IFITM1 appears to mediate inflammatory activation of THP-1 cells since cross-linking of IFITM1 with specific monoclonal antibody against it induced the expression of proinflammatory mediators such as IL-8 and MMP-9. These data indicate that IFITM1 is one of the pro-inflammatory mediators that are induced by signaling initiated by the activation of CD147 in macrophages and activation of ERK, PI3K, and NF-κB is required for the expression of IFITM1

Quantitative measurements of C-reactive protein using silicon nanowire arrays

A silicon nanowire-based sensor for biological application showed highly desirable electrical responses to either pH changes or receptor-ligand interactions such as protein disease markers, viruses, and DNA hybridization. Furthermore, because the silicon nanowire can display results in real-time, it may possess superior characteristics for biosensing than those demonstrated in previously studied methods. However, despite its promising potential and advantages, certain process-related limitations of the device, due to its size and material characteristics, need to be addressed. In this article, we suggest possible solutions. We fabricated silicon nanowire using a top-down and low cost micromachining method, and evaluate the sensing of molecules after transfer and surface modifications. Our newly designed method can be used to attach highly ordered nanowires to various substrates, to form a nanowire array device, which needs to follow a series of repetitive steps in conventional fabrication technology based on a vapor-liquid-solid (VLS) method. For evaluation, we demonstrated that our newly fabricated silicon nanowire arrays could detect pH changes as well as streptavidin-biotin binding events. As well as the initial proof-of-principle studies, C-reactive protein binding was measured: electrical signals were changed in a linear fashion with the concentration (1 fM to 1 nM) in PBS containing 1.37 mM of salts. Finally, to address the effects of Debye length, silicon nanowires coupled with antigen proteins underwent electrical signal changes as the salt concentration changed

Interpreting positive signs of the supraspinatus test in screening for torn rotator cuff.

The purpose of this study was to investigate the validity of the supraspinatus test as a screening test for detecting torn rotator cuff and to determine what its valuable positive signs were. Both the empty-can test and full-can test were performed on 200 shoulders diagnosed by magnetic resonance imaging (MRI)-and in some cases, surgical findings-to have full-thickness or partial-thickness torn rotator cuff s, or no tear in the rotator cuff . During the maneuver, the presence of pain or weakness or both pain and weakness were recorded as positive signs, and the distribution of these signs were analyzed according to the degree of tear. The predictive values were calculated in 2 ways by considering (1) only full-thickness tears as tears and (2) both full- and partial-thickness tears as tears. The 2 tests and the 2 ways of considering partial-thickness tears were compared. Pain and weakness were severity-dependent, and the empty-can test had a higher incidence of pain. The sensitivities of the 2 supraspinatus tests in all positive signs were higher when including partial-thickness tears in the tear group ; however, their specificities were higher when excluding partial-thickness tears. Both pain and weakness were interpretive for the supraspinatus test, and both tests were sensitive to full- and partial- thickness tears and specific for full-thickness tears