207 research outputs found

    Transport or Store? Synthesizing Flow-based Microfluidic Biochips using Distributed Channel Storage

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    Flow-based microfluidic biochips have attracted much atten- tion in the EDA community due to their miniaturized size and execution efficiency. Previous research, however, still follows the traditional computing model with a dedicated storage unit, which actually becomes a bottleneck of the performance of bio- chips. In this paper, we propose the first architectural synthe- sis framework considering distributed storage constructed tem- porarily from transportation channels to cache fluid samples. Since distributed storage can be accessed more efficiently than a dedicated storage unit and channels can switch between the roles of transportation and storage easily, biochips with this dis- tributed computing architecture can achieve a higher execution efficiency even with fewer resources. Experimental results con- firm that the execution efficiency of a bioassay can be improved by up to 28% while the number of valves in the biochip can be reduced effectively.Comment: ACM/IEEE Design Automation Conference (DAC), June 201

    Integrating compressed CO2 energy storage in an oxy-coal combustion power plant with CO2 capture

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    To compensate for the high cost of CO2 capture, this study proposes a novel solution that integrates a compressed CO2 energy storage (CCES) system into an oxy-coal combustion power plant with CO2 capture (Oxy_CCES). The integration of energy storage has the potential to create arbitrage from variations in electricity prices. The proposed Oxy_CCES system can achieve a higher net efficiency of 34.1%, and a higher exergy efficiency of 57.5%, than that of a liquified oxygen storage-integrated oxy-coal combustion power plant (Oxy_O2). Two scenarios, i.e., retrofitting an existing oxy-coal combustion power plant (S–I) and building a new plant (S-II), were established to compare the Oxy_CCES and Oxy_O2. In S–I, the payback time of the Oxy_CCES is one year and in the S-II the levelized cost of electricity (LCOE) of the Oxy_CCES increases by 1.8%, which is lower than that of the Oxy_O2. The sensitivity analysis shows that, when the difference between the peak and the valley electricity prices and the capacities of the energy storage systems increase by 50%, the net present value (NPV) and LCOE of the Oxy_CCES system increase by 113.4% and 1.7% respectively, which are lower than the NPV and LCOE increase of the Oxy_O2

    Transjugular Intrahepatic Portosystemic Shunt for the Treatment of Portal Hypertension in Noncirrhotic Patients with Portal Cavernoma

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    Background. The purpose of this study was to evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) placement in the management of portal hypertension in noncirrhotic patients with portal cavernoma. Methods. We conducted a single institution retrospective analysis of 15 noncirrhotic patients with portal cavernoma treated with TIPS placement. 15 patients (4 women and 11 men) were evaluated via the technical success of TIPS placement, procedural complications, and follow-up shunt patency. Results. TIPS placement was technically successful in 11 out of 15 patients (73.3%). Procedure-related complications were limited to a single instance of hepatic encephalopathy in one patient. In patients with successful shunt placement, the portal pressure gradient decreased from 25.8±5.7 to 9.5±4.2 mmHg (P<0.001). TIPS dysfunction occurred in two patients during a median follow-up time of 45.2 months. Revision was not performed in one patient due to inadequate inflow. The other patient died of massive gastrointestinal bleeding in a local hospital. The remaining nine patients maintained functioning shunts through their last evaluation. Conclusions. TIPS is a safe and effective therapeutic treatment for noncirrhotic patients with symptomatic portal hypertension secondary to portal cavernoma

    Impersonation Attacks on Lightweight Anonymous Authenticated Key Exchange Scheme for IoT

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    Recently, in IEEE Internet of Things Journal (DOI: 10.1109/JIOT.2019.2923373 ), Banerjee et al. proposed a lightweight anonymous authenticated key exchange scheme for IoT based on symmetric cryptography. In this paper, we show that the proposal can not resist impersonation attacks due to vulnerable mutual authentication, and give improvements

    VisKoP: Visual Knowledge oriented Programming for Interactive Knowledge Base Question Answering

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    We present Visual Knowledge oriented Programming platform (VisKoP), a knowledge base question answering (KBQA) system that integrates human into the loop to edit and debug the knowledge base (KB) queries. VisKoP not only provides a neural program induction module, which converts natural language questions into knowledge oriented program language (KoPL), but also maps KoPL programs into graphical elements. KoPL programs can be edited with simple graphical operators, such as dragging to add knowledge operators and slot filling to designate operator arguments. Moreover, VisKoP provides auto-completion for its knowledge base schema and users can easily debug the KoPL program by checking its intermediate results. To facilitate the practical KBQA on a million-entity-level KB, we design a highly efficient KoPL execution engine for the back-end. Experiment results show that VisKoP is highly efficient and user interaction can fix a large portion of wrong KoPL programs to acquire the correct answer. The VisKoP online demo https://demoviskop.xlore.cn (Stable release of this paper) and https://viskop.xlore.cn (Beta release with new features), highly efficient KoPL engine https://pypi.org/project/kopl-engine, and screencast video https://youtu.be/zAbJtxFPTXo are now publicly available

    Comparison of the fecal microbiota of two free-ranging Chinese subspecies of the leopard (Panthera pardus) using high-throughput sequencing

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    The analysis of gut microbiota using fecal samples provides a non-invasive approach to understand the complex interactions between host species and their intestinal bacterial community. However, information on gut microbiota for wild endangered carnivores is scarce. The goal of this study was to describe the gut microbiota of two leopard subspecies, the Amur leopard (Panthera pardus orientalis) and North Chinese leopard (Panthera pardus japonensis). Fecal samples from the Amur leopard (n = 8) and North Chinese leopard (n = 13) were collected in Northeast Tiger and Leopard National Park and Shanxi Tieqiaoshan Provincial Nature Reserve in China, respectively. The gut microbiota of leopards was analyzed via high-throughput sequencing of the V3–V4 region of bacterial 16S rRNA gene using the Life Ion S5™ XL platform. A total of 1,413,825 clean reads representing 4,203 operational taxonomic units (OTUs) were detected. For Amur leopard samples, Firmicutes (78.4%) was the dominant phylum, followed by Proteobacteria (9.6%) and Actinobacteria (7.6%). And for the North Chinese leopard, Firmicutes (68.6%), Actinobacteria (11.6%) and Fusobacteria (6.4%) were the most predominant phyla. Clostridiales was the most diverse bacterial order with 37.9% for Amur leopard and 45.7% for North Chinese leopard. Based on the beta-diversity analysis, no significant difference was found in the bacterial community composition between the Amur leopard and North Chinese leopard samples. The current study provides the initial data about the composition and structure of the gut microbiota for wild Amur leopards and North Chinese leopards, and has laid the foundation for further investigations of the health, dietary preferences and physiological regulation of leopards

    Activation loop dynamics are controlled by conformation-selective inhibitors of ERK2

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    Conformational selection by small molecules expands inhibitory possibilities for protein kinases. Nuclear magnetic resonance (NMR) measurements of the mitogen-activated protein (MAP) kinase ERK2 have shown that activation by dual phosphorylation induces global motions involving exchange between two states, L and R. We show that ERK inhibitors Vertex-11e and SCH772984 exploit the small energetic difference between L and R to shift the equilibrium in opposing directions. An X-ray structure of active 2P-ERK2 complexed with AMP-PNP reveals a shift in the Gly-rich loop along with domain closure to position the nucleotide in a more catalytically productive conformation relative to inactive 0P-ERK2:ATP. X-ray structures of 2P-ERK2 complexed with Vertex-11e or GDC-0994 recapitulate this closure, which is blocked in a complex with a SCH772984 analog. Thus, the L→R shift in 2P-ERK2 is associated with movements needed to form a competent active site. Solution measurements by hydrogen-exchange mass spectrometry (HX-MS) reveal distinct binding interactions for Vertex-11e, GDC-0994, and AMP-PNP with active vs. inactive ERK2, where the extent of HX protection correlates with R state formation. Furthermore, Vertex-11e and SCH772984 show opposite effects on HX near the activation loop. Consequently, these inhibitors differentially affect MAP kinase phosphatase activity toward 2P-ERK2. We conclude that global motions in ERK2 reflect conformational changes at the active site that promote productive nucleotide binding and couple with changes at the activation loop to allow control of dephosphorylation by conformationally selective inhibitors

    Orbital parameters for an ELM white dwarf with a white dwarf companion: LAMOST J033847.06+413424.2

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    Double white dwarf systems are of great astrophysical importance in the field of gravitational wave and Type Ia supernova. While the binary fraction of CO core white dwarf is about a few percents, the extremely low mass white dwarfs are all thought to be within binary systems. In this work, we report the orbital solution of a double degenerate system: J033847.06+413424.24, an extremely low mass He core white dwarf orbiting a CO core white dwarf. With LAMOST and P200, time domain spectroscopic observations have been made and spectral atmosphere parameters are estimated to be Teff∼22500T_{\rm eff}\sim22500 K and log g∼5.6g\sim5.6 dex. Combining Gaia parallax, 3D extinction, and evolution tracks, we estimate a radius of ∼0.12\sim0.12 R⊙R_{\odot} and a mass of ∼0.22\sim0.22 M⊙M_{\odot}. With the 37 single exposure spectra, the radial velocities are measured and the orbital parameters are estimated to be P=0.1253132(1)P=0.1253132(1) days, K1=289±4K1=289\pm4 km/s and Vsys=−41±3V_{sys}=-41\pm3 km/s. The radial velocity based system ephemeris is also provided. The light curves from several photometric surveys show no orbital modulation. The orbital solution suggests that the invisible companion has a minimum mass of about 0.60 M⊙M_{\odot} and is ∼0.79\sim0.79 M⊙M_{\odot} for an inclination of 60.0∘60.0^{\circ}, indicating most probably a CO core white dwarf. The system is expected to merge in about 1 Gyr. With present period and distance (∼596\sim596 pc) it can not irradiate strong enough gravitational wave for LISA. More double degenerate systems are expected to be discovered and parameterized as the LAMOST survey goes on.Comment: 12 pages, 11 figure
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