12 research outputs found

    Joltik: Enabling Energy-Efficient \ "Future-Proof" Analytics on Low-Power Wide-Area Networks

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    Wireless sensors have enabled a number of key complications. Despite many advances in sensing, computation and wireless technologies, simultaneously achieving energy-efficiency, fidelity, and generality across many (possibly unforeseen) metrics, has remained elusive. To this end, this paper presents Joltik , a framework enablinggeneral and energy efficient analytics for low power wireless sensors. Joltik is built upon recent theoretical advances in universal sketching, which can enable a Joltik sensor node to report a compact summary of observed data to enable a large class of statistical summaries. We address key system design and implementation challenges with respect to communication, memory and computation bottlenecks that arise in practically realizing the potential benefits of universal sketching in the low-power regime. We present a proof-of-concept evaluation of Joltik in LoRaWAN NUCLEO-L476RGboards and sensors and conduct experiments in a local testbed. Across a range of realistic datasets, Joltik provides significant reduction in energy cost compared to transmittingraw data and outperforms many natural alternatives (e.g., sub-sampling, custom sketches, compressed sensing) in terms of energy-accuracy tradeoffs.</div

    Challenging the Stateless Quo of Programmable Switches

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    Ā© 2020 ACM. Programmable switches based on the Protocol Independent Switch Architecture (PISA) have greatly enhanced the flexibility of today's networks by allowing new packet protocols to be deployed without any hardware changes. They have also been instrumental in enabling a new computing paradigm in which parts of an application's logic run within the network core (in-network computing). The characteristics and requirements of in/-network applications, however, are quite different from those of packet protocols for which programmable switches were originally designed. Packet protocols are typically stateless, while in-network applications require frequent operations on shared state maintained in the switch. This mismatch increases the developing complexity of in-network computing and hampers widespread adoption. In this paper, we describe the key obstacles to developing in-network applications on PISA and propose rethinking the current switch architecture. Rather than changing the existing architecture, we propose augmenting it with a Stateful Data Plane (SDP). The SDP supports the requirements of stateful applications, while the conventional data plane (CDP) performs packet-protocol functions

    Effects of inlet working condition and heat load on supercritical CO2 compressor performance

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    The supercritical carbon dioxide (sCO2) Brayton power cycle is more effective than the conventional power cycle and is more widely applicable to heat sources. The inlet working conditions of the compressor have a higher influence on their operating performance because the thermophysical properties of the CO2 vary dramatically close to the critical point. The flow in the sCO2 compressor is simulated and the compressor performance is analyzed. The results show that the sCO2 centrifugal compressor operates outside of its intended parameters due to the change in inlet temperature. The sCO2 compressor requires more power as the inlet temperature increases. The compressor power is 582Ā kW when the inlet temperature is at 304Ā K. But the power is doubled when the inlet temperature increases to 314Ā K, and the change in the isentropic efficiency is within 5%. The increase in the inlet temperature significantly reduces the risk of condensation in centrifugal compressors. When the heat load of the sCO2 power system changes, the inlet pressure to the turbine can be kept constant by regulating the rotational speed of compressors. With the increase in rotational speed, the incidence loss and condensation risk increase

    Pro-Apoptotic Effect of Zeolitic Imidazolate Framework-8 (ZIF-8)-Loaded Dihydromyricetin on HepG2 Cells

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    Dihydromyricetin (DHM) has garnered attention due to its promising antitumor activity, but its low bioavailability restricts its clinical application. Thus, developing nano-drug delivery systems could enhance its antitumor activity. We prepared DHM@ZIF-8 nanoparticles using the zeolite imidazole framework-8 (ZIF-8) as a carrier loaded with dihydromyricetin. A series of characterizations were performed, including morphology, particle size, zeta potential, X-single crystal diffraction, ultraviolet spectroscopy, infrared spectroscopy, and Brunauer&ndash;Emmett&ndash;Teller (BET). The in vitro release characteristics of DHM@ZIF-8 under pH = 5.0 and pH = 7.4 were studied using membrane dialysis. The antitumor activity and pro-apoptotic mechanism of DHM@ZIF-8 were investigated through CCK-8 assay, reactive oxygen species (ROS), Annexin V/PI double-staining, transmission electron microscopy, and Western blot. The results depicted that DHM@ZIF-8 possessed a regular morphology with a particle size of 211.07 &plusmn; 9.65 nm (PDI: 0.19 &plusmn; 0.06) and a Zeta potential of &minus;28.77 &plusmn; 0.67 mV. The 24 h drug releasing rate in PBS solution at pH = 7.4 was 32.08% and at pH = 5.0 was 85.52% in a simulated tumor micro acid environment. DHM@ZIF-8 could significantly enhance the killing effect on HepG2 cells compared to the prodrug. It can effectively remove ROS from the tumor cells, promote apoptosis, and significantly affect the expression of apoptosis-related proteins within tumor cells

    Dissecting the Single-Cell Transcriptome Network Underlying Gastric Premalignant Lesions and Early Gastric Cancer

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    Summary: Intestinal-type gastric cancer is preceded by premalignant lesions, including chronic atrophic gastritis and intestinal metaplasia. In this study, we constructed a single-cell atlas for 32,332 high-quality cells from gastric antral mucosa biopsies of patients spanning a cascade of gastric premalignant lesions and early gastric cancer (EGC) using single-cell RNA sequencing. We then constructed a single-cell network underlying cellular and molecular characteristics of gastric epithelial cells across different lesions. We found that gland mucous cells tended to acquire an intestinal-like stem cell phenotype during metaplasia, and we identified OR51E1 as a marker for unique endocrine cells in the early-malignant lesion. We also found that HES6 might mark the pre-goblet cell cluster, potentially aiding identification of metaplasia at the early stage. Finally, we identified a panel of EGC-specific signatures, with clinical implications for the precise diagnosis of EGC. Our study offers unparalleled insights into the human gastric cellulome in premalignant and early-malignant lesions. : Zhang etĀ al. conduct a single-cell transcriptomic study on gastric antral biopsies from patients across premalignant lesions and early gastric cancer. They construct the single-cell network for epithelial cells across lesions and dissect the molecular characteristics for representative cell types in each lesion. Keywords: single-cell, stomach, premalignant lesions, early gastric cancer, networ

    Bioinspired gradient scaffolds for osteochondral tissue engineering

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    Abstract Repairing articular osteochondral defects present considerable challenges in selfā€repair due to the complex tissue structure and low proliferation of chondrocytes. Conventional clinical therapies have not shown significant efficacy, including microfracture, autologous/allograft osteochondral transplantation, and cellā€based techniques. Therefore, tissue engineering has been widely explored in repairing osteochondral defects by leveraging the natural regenerative potential of biomaterials to control cell functions. However, osteochondral tissue is a gradient structure with a smooth transition from the cartilage to subchondral bone, involving changes in chondrocyte morphologies and phenotypes, extracellular matrix components, collagen type and orientation, and cytokines. Bioinspired scaffolds have been developed by simulating gradient characteristics in heterogeneous tissues, such as the pores, components, and osteochondrogenesisā€inducing factors, to satisfy the anisotropic features of osteochondral matrices. Bioinspired gradient scaffolds repair osteochondral defects by altering the microenvironments of cell growth to induce osteochondrogenesis and promote the formation of osteochondral interfaces compared with homogeneous scaffolds. This review outlines the meaningful strategies for repairing osteochondral defects by tissue engineering based on gradient scaffolds and predicts the pros and cons of prospective translation into clinical practice
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