VLSI Architectures for the Steerable-Discrete-Cosine-Transform (SDCT)

Since frame resolution of modern video streams is rapidly growing, the need for more complex and efficient video compression methods arises. H.265/HEVC represents the state of the art in video coding standard. Its architecture is however not completely standardized, as many parts are only described at software level to allow the designer to implement new compression techniques. This paper presents an innovative hardware architecture for the Steerable Discrete Cosine Transform (SDCT), which has been recently embedded into the HEVC standard, providing better compression ratios. Such technique exploits directional DCT using basis having different orientation angles, leading to a sparser representation which translates to an improved coding efficiency. The final design is able to work at a frequency of 188 MHZ, reaching a throughput of 3.00 GSample/s. In particular, this architecture supports 8k UltraHigh Definition (UHD) (7680 × 4320) with a frame rate of 60 Hz, which is one of the best resolutions supported by HEVC

Genetic Analysis of the Functions and Interactions of Components of the LevQRST Signal Transduction Complex of Streptococcus mutans

Transcription of the genes for a fructan hydrolase (fruA) and a fructose/mannose sugar:phosphotransferase permease (levDEFG) in Streptococcus mutans is activated by a four-component regulatory system consisting of a histidine kinase (LevS), a response regulator (LevR) and two carbohydrate-binding proteins (LevQT). The expression of the fruA and levD operons was at baseline in a levQ mutant and substantially decreased in a levT null mutant, with lower expression with the cognate inducers fructose or mannose, but slightly higher expression in glucose or galactose. A strain expressing levQ with two point mutations (E170A/F292S) did not require inducers to activate gene expression and displayed altered levD expression when growing on various carbohydrates, including cellobiose. Linker-scanning (LS) mutagenesis was used to generate three libraries of mutants of levQ, levS and levT that displayed various levels of altered substrate specificity and of fruA/levD gene expression. The data support that LevQ and LevT are intimately involved in the sensing of carbohydrate signals, and that LevQ appears to be required for the integrity of the signal transduction complex, apparently by interacting with the sensor kinase LevS

Optoelectronics with electrically tunable PN diodes in a monolayer dichalcogenide

One of the most fundamental devices for electronics and optoelectronics is the PN junction, which provides the functional element of diodes, bipolar transistors, photodetectors, LEDs, and solar cells, among many other devices. In conventional PN junctions, the adjacent p- and n-type regions of a semiconductor are formed by chemical doping. Materials with ambipolar conductance, however, allow for PN junctions to be configured and modified by electrostatic gating. This electrical control enables a single device to have multiple functionalities. Here we report ambipolar monolayer WSe2 devices in which two local gates are used to define a PN junction exclusively within the sheet of WSe2. With these electrically tunable PN junctions, we demonstrate both PN and NP diodes with ideality factors better than 2. Under excitation with light, the diodes show photodetection responsivity of 210 mA/W and photovoltaic power generation with a peak external quantum efficiency of 0.2%, promising numbers for a nearly transparent monolayer sheet in a lateral device geometry. Finally, we demonstrate a light-emitting diode based on monolayer WSe2. These devices provide a fundamental building block for ubiquitous, ultra-thin, flexible, and nearly transparent optoelectronic and electronic applications based on ambipolar dichalcogenide materials.Comment: 14 pages, 4 figure

Exceptional Performance of Room Temperature Sputtered Flexible Thermoelectric Thin Film Using High Target Utilisation Sputtering Technique

The High Target Utilisation Sputtering technique (HiTUS) is of interest for industrial processes, including in roll-to-roll manufacturing. This study marks the first application of HiTUS to thermoelectric materials, exemplified by bismuth telluride. The HiTUS technique separates the sputtering power into the plasma power and the target power, with additional kinetic energy in the sputtering particles from the applied electrical field, thus enabling a much wider sputter parameter space to modify the film performance. This study investigates how plasma power, target power, and substrate bias in HiTUS intricately influence crystal orientation/size, elemental composition, surface morphology, and other film properties. These factors subsequently affect carrier density/mobility, and consequently the thermoelectric performance of the bismuth telluride film. These deposited films reach a power factor of 6.5 × 10−4 W m−1 K−2 with a figure of merit ≈0.14 at room temperature, the highest value for room-temperature sputtered un-doped bismuth telluride. Subsequent post-deposition annealing significantly enhances the crystallinity of the film (highly polycrystalline), further improving the power factor to 23.5 × 10−4 W m−1 K-2, with a figure of merit ≈0.45 at room temperature. The excellent performance of the HiTUS fabricated thermoelectric film opens opportunities for the large-area manufacture of thin-film thermoelectric materials and devices

Electrically Tunable Excitonic Light Emitting Diodes based on Monolayer WSe2 p-n Junctions

Light-emitting diodes are of importance for lighting, displays, optical interconnects, logic and sensors. Hence the development of new systems that allow improvements in their efficiency, spectral properties, compactness and integrability could have significant ramifications. Monolayer transition metal dichalcogenides have recently emerged as interesting candidates for optoelectronic applications due to their unique optical properties. Electroluminescence has already been observed from monolayer MoS2 devices. However, the electroluminescence efficiency was low and the linewidth broad due both to the poor optical quality of MoS2 and to ineffective contacts. Here, we report electroluminescence from lateral p-n junctions in monolayer WSe2 induced electrostatically using a thin boron nitride support as a dielectric layer with multiple metal gates beneath. This structure allows effective injection of electrons and holes, and combined with the high optical quality of WSe2 it yields bright electroluminescence with 1000 times smaller injection current and 10 times smaller linewidth than in MoS2. Furthermore, by increasing the injection bias we can tune the electroluminescence between regimes of impurity-bound, charged, and neutral excitons. This system has the required ingredients for new kinds of optoelectronic devices such as spin- and valley-polarized light-emitting diodes, on-chip lasers, and two-dimensional electro-optic modulators.Comment: 13 pages main text with 4 figures + 4 pages upplemental material

Using electric current to surpass the microstructure breakup limit

The elongated droplets and grains can break up into smaller ones. This process is driven by the interfacial free energy minimization, which gives rise to a breakup limit. We demonstrated in this work that the breakup limit can be overpassed drastically by using electric current to interfere. Electric current free energy is dependent on the microstructure configuration. The breakup causes the electric current free energy to reduce in some cases. This compensates the increment of interfacial free energy during breaking up and enables the processing to achieve finer microstructure. With engineering practical electric current parameters, our calculation revealed a significant increment of the obtainable number of particles, showing electric current a powerful microstructure refinement technology. The calculation is validated by our experiments on the breakup of Fe3C-plates in Fe matrix. Furthermore, there is a parameter range that electric current can drive spherical particles to split into smaller ones

Identification of plasma lipid biomarkers for prostate cancer by lipidomics and bioinformatics

Background: Lipids have critical functions in cellular energy storage, structure and signaling. Many individual lipid molecules have been associated with the evolution of prostate cancer; however, none of them has been approved to be used as a biomarker. The aim of this study is to identify lipid molecules from hundreds plasma apparent lipid species as biomarkers for diagnosis of prostate cancer. Methodology/Principal Findings: Using lipidomics, lipid profiling of 390 individual apparent lipid species was performed on 141 plasma samples from 105 patients with prostate cancer and 36 male controls. High throughput data generated from lipidomics were analyzed using bioinformatic and statistical methods. From 390 apparent lipid species, 35 species were demonstrated to have potential in differentiation of prostate cancer. Within the 35 species, 12 were identified as individual plasma lipid biomarkers for diagnosis of prostate cancer with a sensitivity above 80%, specificity above 50% and accuracy above 80%. Using top 15 of 35 potential biomarkers together increased predictive power dramatically in diagnosis of prostate cancer with a sensitivity of 93.6%, specificity of 90.1% and accuracy of 97.3%. Principal component analysis (PCA) and hierarchical clustering analysis (HCA) demonstrated that patient and control populations were visually separated by identified lipid biomarkers. RandomForest and 10-fold cross validation analyses demonstrated that the identified lipid biomarkers were able to predict unknown populations accurately, and this was not influenced by patient's age and race. Three out of 13 lipid classes, phosphatidylethanolamine (PE), ether-linked phosphatidylethanolamine (ePE) and ether-linked phosphatidylcholine (ePC) could be considered as biomarkers in diagnosis of prostate cancer. Conclusions/Significance: Using lipidomics and bioinformatic and statistical methods, we have identified a few out of hundreds plasma apparent lipid molecular species as biomarkers for diagnosis of prostate cancer with a high sensitivity, specificity and accuracy

Predictors for neonatal death in the rural areas of Shaanxi Province of Northwestern China: a cross-sectional study

Background Almost all (99%) neonatal deaths arise in low-income and middle-income countries. Approximately 450 new-born children die every hour, which is mainly from preventable causes. There has been increased recognition of the need for these countries to implement public health interventions that specifically target neonatal deaths. The purpose of this paper is to identify the predictors of neonatal death in Type 4 rural (poorest) counties in Shaanxi Province of northwestern China. Methods A cross-sectional study was conducted in Shaanxi Province, China. A single-stage survey design was identified to estimate standard errors. Because of concern about the complex sample design, the data were analysed using multivariate logistic regression analysis. Socioeconomic and maternal health service utilization factors were added into the model. Results During the study period, a total of 4750 women who delivered in the past three years were randomly selected for interview in the five counties. There were 4880 live births and 54 neonatal deaths identified. In the multiple logistic regression, the odds of neonatal death was significantly higher for multiparous women (OR = 2.77; 95% CI: 1.34, 5.70) and women who did not receive antennal health care in the first trimester of pregnancy (OR = 2.49; 95% CI: 1.41, 4.40). Women who gave birth in a county-level hospital (OR = 0.18; 95% CI: 0.04, 0.86) and had junior high school or higher education level (OR = 0.20; 95% CI: 0.05, 0.84) were significantly protected from neonatal death. Conclusions Public health interventions directed at reducing neonatal death should address the socioeconomic factors and maternal health service utilization, which significantly influence neonatal mortality in rural China. Multipara, low educational level of the women, availability of prenatal visits in the first trimester of pregnancy and hospital delivery should be considered when planning the interventions to reduce the neonatal mortality in rural areas

An introduction to Graph Data Management

A graph database is a database where the data structures for the schema and/or instances are modeled as a (labeled)(directed) graph or generalizations of it, and where querying is expressed by graph-oriented operations and type constructors. In this article we present the basic notions of graph databases, give an historical overview of its main development, and study the main current systems that implement them