98 research outputs found
Design of a multicast router for network-on-chip architectures with irregular topologies
As chip complexity keeps increasing in system-on-chip (SoC), the on-chip interconnect has become a critical issue for large-scale chip design.It has been proposed that the packet-switched network exchanging messages between intellectual property (IP) cores is a viable solution for the SoC interconnect problem.The design of the router in such network-on-chip (NoC) architectures is the key to high-performance communication for the IP cores in SoC. In this paper, we present the design and implementation of a multicast router for NoC with irregular topologies.The router employs our previously proposed tree-based routing algorithm for irregular networks.Our experiment results show that the multicast router has a slightly lower clock rate and moderately larger chip area than the unicast router in NoC.Since multicasting is a technique providing superior network performance, especially for large networks, such multicast router design is an effective routing solution for large-scale network-on-chip architectures
Millimeter-Wave Array Antenna Architectures Employing Joint Power Combining and Beam Steering for Next-Generation Backhaul Applications
We investigate the capabilities and limitations of joint power-combining and beam-steering techniques for millimeter-wave antenna applications. In this analysis, both functionalities are realized simultaneously through a power-combining and beamforming (PC-BF) network interconnecting an input array of active channels with an array of antenna elements. The first part of the paper provides a review of state-of-the-art hardware architectures of such PC-BF networks and examines their suitability for millimeter-wave applications. The architectures are grouped into two classes depending on the array embedded element patterns properties. Next, a unified PC-BF network is proposed where both functionalities are implemented in a single millimeter-wave waveguiding block. A full-wave model of such a network with 6 inputs and 7 outputs is investigated, with its application demonstrated for a W-band focal-plane array feeding a backhaul reflector antenna
Dome-Shaped Ellipsoidal Reflector Antenna for UHF-RFID Readers with Confined Near-Field Detection Region
This letter proposes and demonstrates the concept of ellipsoidal reflector antennas for radio frequency identification reader applications at UHF band. The antenna can be potentially integrated with environmental structures to confine the reader detection region. The energy bounding characteristics result from the dual-focus feature of an ellipsoidal reflector in its near-field region, as the feed located at one of the two foci can create a focused field distribution around the other focus. An axial energy focusing is, thus, formed to confine the energy in a restricted region (near-field beam focusing), also minimizing the interference effects outside of the targeted area. Both numerical simulations and experimental results are presented to demonstrate the feasibility of this antenna concept
Radiation optimization for phased arrays of antennas incorporating the constraints of active reflection coefficients
High-power radiations from active antenna arrays may result in strong reflected power to cause RF device breakdown by the strong inter-element mutual coupling. An excitation weighting synthesis of antenna arrays incorporating the constraint of active reflection/transmission coefficients between antenna elements is presented to optimize the radiation. It may enhance inter-element isolation, reducing the effort of using sophisticated hardware-based structures that have difficulty in broad-angle beam steering. In the synthesis, the cost functions incorporate the difference between the optimized and the predefined excitation weightings of radiation patterns with limited reflected power or active reflection coefficients as a constraint. This paper first introduces the basic concept to show the operational mechanisms. Practical definitions of cost functions are described to synthesize the radiation pattern considering the mutual coupling effects. The case without setting an initial desired radiation pattern is also examined for comparison. Numerical full-wave simulations are presented to validate the synthesis concepts by examining the characteristics of gain, sidelobe level (SLL), and port reflection coefficients
miRTarBase update 2014: an information resource for experimentally validated miRNA-target interactions
MicroRNAs (miRNAs) are small non-coding RNA molecules capable of negatively regulating gene expression to control many cellular mechanisms. The miRTarBase database (http://mirtarbase.mbc.nctu.edu.tw/) provides the most current and comprehensive information of experimentally validated miRNA-target interactions. The database was launched in 2010 with data sources for >100 published studies in the identification of miRNA targets, molecular networks of miRNA targets and systems biology, and the current release (2013, version 4) includes significant expansions and enhancements over the initial release (2010, version 1). This article reports the current status of and recent improvements to the database, including (i) a 14-fold increase to miRNA-target interaction entries, (ii) a miRNA-target network, (iii) expression profile of miRNA and its target gene, (iv) miRNA target-associated diseases and (v) additional utilities including an upgrade reminder and an error reporting/user feedback system
Enhanced Differentiation of Three-Gene-Reprogrammed Induced Pluripotent Stem Cells into Adipocytes via Adenoviral-Mediated PGC-1α Overexpression
Induced pluripotent stem cells formed by the introduction of only three factors, Oct4/Sox2/Klf4 (3-gene iPSCs), may provide a safer option for stem cell-based therapy than iPSCs conventionally introduced with four-gene iPSCs. Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) plays an important role during brown fat development. However, the potential roles of PGC-1α in regulating mitochondrial biogenesis and the differentiation of iPSCs are still unclear. Here, we investigated the effects of adenovirus-mediated PGC-1α overexpression in 3-gene iPSCs. PGC-1α overexpression resulted in increased mitochondrial mass, reactive oxygen species production, and oxygen consumption. Microarray-based bioinformatics showed that the gene expression pattern of PGC-1α-overexpressing 3-gene iPSCs resembled the expression pattern observed in adipocytes. Furthermore, PGC-1α overexpression enhanced adipogenic differentiation and the expression of several brown fat markers, including uncoupling protein-1, cytochrome C, and nuclear respiratory factor-1, whereas it inhibited the expression of the white fat marker uncoupling protein-2. Furthermore, PGC-1α overexpression significantly suppressed osteogenic differentiation. These data demonstrate that PGC-1α directs the differentiation of 3-gene iPSCs into adipocyte-like cells with features of brown fat cells. This may provide a therapeutic strategy for the treatment of mitochondrial disorders and obesity
Oncologic impact of delay between diagnosis and radical nephroureterectomy
PurposeThis study aimed to evaluate the oncological outcome of delayed surgical wait time from the diagnosis of upper tract urothelial carcinoma (UTUC) to radical nephroureterectomy (RNU).MethodsIn this multicenter retrospective study, medical records were collected between 1988 and 2021 from 18 participating Taiwanese hospitals under the Taiwan UTUC Collaboration Group. Patients were dichotomized into the early (≤90 days) and late (>90 days) surgical wait-time groups. Overall survival, disease-free survival, and bladder recurrence-free survival were calculated using the Kaplan–Meier method and multivariate Cox regression analysis. Multivariate analysis was performed using stepwise linear regression.ResultsOf the 1251 patients, 1181 (94.4%) were classifed into the early surgical wait-time group and 70 (5.6%) into the late surgical wait-time group. The median surgical wait time was 21 days, and the median follow-up was 59.5 months. Our study showed delay-time more than 90 days appeared to be associated with worse overall survival (hazard ratio [HR] 1.974, 95% confidence interval [CI] 1.166−3.343, p = 0.011), and disease-free survival (HR 1.997, 95% CI 1.137−3.507, p = 0.016). This remained as an independent prognostic factor after other confounding factors were adjusted. Age, ECOG performance status, Charlson Comorbidity Index (CCI), surgical margin, tumor location and adjuvant systemic therapy were independent prognostic factors for overall survival. Tumor location and adjuvant systemic therapy were also independent prognostic factors for disease-free survival.ConclusionsFor patients with UTUC undergoing RNU, the surgical wait time should be minimized to less than 90 days. Prolonged delay times may be associated with poor overall and disease-free survival
Berberine enhances inhibition of glioma tumor cell migration and invasiveness mediated by arsenic trioxide
<p>Abstract</p> <p>Background</p> <p>Arsenic trioxide (As<sub>2</sub>O<sub>3</sub>) exhibits promising anticarcinogenic activity in acute promyelocytic leukemic patients and induces apoptosis in various tumor cells <it>in vitro</it>. Here, we investigated the effect of the natural alkaloid berberine on As<sub>2</sub>O<sub>3</sub>-mediated inhibition of cancer cell migration using rat and human glioma cell lines.</p> <p>Methods</p> <p>The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine the viability of rat C6 and human U-87 glioma cells after treatment with As<sub>2</sub>O<sub>3 </sub>or berberine, and after co-treatment with As<sub>2</sub>O<sub>3 </sub>and berberine. The wound scratch and Boyden chamber assays were applied to determine the effect of As<sub>2</sub>O<sub>3 </sub>and berberine on the migration capacity and invasiveness of glioma cancer cells. Zymography and Western blot analyses provided information on the effect of As<sub>2</sub>O<sub>3 </sub>and berberine on the intracellular translocation and activation of protein kinase C (PKC), and some PKC-related downstream factors. Most assays were performed three times, independently, and data were analyzed using ANOVA.</p> <p>Results</p> <p>The cell viability studies demonstrated that berberine enhances As<sub>2</sub>O<sub>3</sub>-mediated inhibition of glioma cell growth after 24 h incubation. Untreated control cells formed a confluent layer, the formation of which was inhibited upon incubation with 5 μM As<sub>2</sub>O<sub>3</sub>. The latter effect was even more pronounced in the presence of 10 μM berberine. The As<sub>2</sub>O<sub>3</sub>-mediated reduction in motility and invasion of glioma cells was enhanced upon co-treatment with berberine. Furthermore, it has been reported that PKC isoforms influence the morphology of the actin cytoskeleton, as well as the activation of metalloproteases MT1-MMP and MMP-2, reported to be involved in cancer cell migration. Treatment of glioma cells with As<sub>2</sub>O<sub>3 </sub>and berberine significantly decreased the activation of PKC α and ε and led to actin cytoskeleton rearrangements. The levels of two downstream transcription factors, myc and jun, and MT1-MMP and MMP-2 were also significantly reduced.</p> <p>Conclusion</p> <p>Upon co-treatment of glioma cells with As<sub>2</sub>O<sub>3 </sub>and berberine, cancer cell metastasis can be significantly inhibited, most likely by blocking the PKC-mediated signaling pathway involved in cancer cell migration. This study is potentially interesting for the development of novel chemotherapeutic approaches in the treatment of malignant gliomas and cancer development in general.</p
Impact of clinical parameters and systemic inflammatory status on epidermal growth factor receptor-mutant non-small cell lung cancer patients readministration with epidermal growth factor receptor tyrosine kinase inhibitors
Near-Field Finite-Zone Focused Radiation From Reflector Antenna With Continuously Tapered Ellipsoidal Surface Curvatures
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