977 research outputs found

    Design Techniques for Energy Efficient Multi-GB/S Serial I/O Transceivers

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    Total I/O bandwidth demand is growing in high-performance systems due to the emergence of many-core microprocessors and in mobile devices to support the next generation of multi-media features. High-speed serial I/O energy efficiency must improve in order to enable continued scaling of these parallel computing platforms in applications ranging from data centers to smart mobile devices. The first work, a low-power forwarded-clock I/O transceiver architecture is presented that employs a high degree of output/input multiplexing, supply-voltage scaling with data rate, and low-voltage circuit techniques to enable low-power operation. The transmitter utilizes a 4:1 output multiplexing voltage-mode driver along with 4-phase clocking that is efficiently generated from a passive poly-phase filter. The output driver voltage swing is accurately controlled from 100-200 mV_(ppd) using a low-voltage pseudo-differential regulator that employs a partial negative-resistance load for improved low frequency gain. 1:8 input de-multiplexing is performed at the receiver equalizer output with 8 parallel input samplers clocked from an 8-phase injection-locked oscillator that provides more than 1UI de-skew range. Low-power high-speed serial I/O transmitters which include equalization to compensate for channel frequency dependent loss are required to meet the aggressive link energy efficiency targets of future systems. The second work presents a low power serial link transmitter design that utilizes an output stage which combines a voltage-mode driver, which offers low static-power dissipation, and current-mode equalization, which offers low complexity and dynamic-power dissipation. The utilization of current-mode equalization decouples the equalization settings and termination impedance, allowing for a significant reduction in pre-driver complexity relative to segmented voltage-mode drivers. Proper transmitter series termination is set with an impedance control loop which adjusts the on-resistance of the output transistors in the driver voltage-mode portion. Further reductions in dynamic power dissipation are achieved through scaling the serializer and local clock distribution supply with data rate. Finally, it presents that a scalable quarter-rate transmitter employs an analog-controlled impedance-modulated 2-tap voltage-mode equalizer and achieves fast power-state transitioning with a replica-biased regulator and ILO clock generation. Capacitively-driven 2 mm global clock distribution and automatic phase calibration allows for aggressive supply scaling

    Postbiotic heat-killed lactobacilli modulates on body weight associated with gut microbiota in a pig model

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    For decades, Lactobacillus has been extensively used as beneficial probiotics because it positively effects on the intestinal health of the host and has been studying its possible serve to treat obesity as well as various diseases. This research aimed to investigate the effects of heat-killed Ligilactobacillus salivarius strain 189 (HK LS 189) supplementation on anti-obesity and gut microbiota. A total of 48 pigs were fed either a basal diet or a diet supplemented with HK LS 189 for 4 weeks. The impact of HK LS 189 supplementation on the composition and function of the intestinal microbiota was revealed by 16 S rRNA gene sequencing. HK LS 189 supplementation significantly decreased growth performance. Moreover, HK LS 189 supplementation altered the gut microbiota of the pigs by decreasing the proportion of Prevotella and increasing the proportion of Parabacteroides. Beta-diversity analysis showed a significant difference between the two groups. The results support the potential use of HK LS 189 for its anti-obesity effect in pigs through modulation of the gut microbiota. Furthermore, we found changes in the functional pathways of the gut microbiota. The functional pathway study indicated that metabolism and lipid metabolism differed between the two groups. Our data may contribute to understanding the potential use of postbiotic supplementation with HK LS 189 for improving the anti-obesity effects.This research was supported by a National Research Foundation of Korea Grant, funded by the Korean government (MEST) (NRF-2021R1A2C3011051) and by the support of “Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ0158652021)” Rural Development Administration, Republic of Korea

    Use of Coal Bottom Ash and CaO-CaCl2-Activated GGBFS Binder in the Manufacturing of Artificial Fine Aggregates through Cold-Bonded Pelletization

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    This study investigated the use of coal bottom ash (bottom ash) and CaO-CaCl2-activated ground granulated blast furnace slag (GGBFS) binder in the manufacturing of artificial fine aggregates using cold-bonded pelletization. Mixture samples were prepared with varying added contents of bottom ash of varying added contents of bottom ash relative to the weight of the cementless binder (= GGBFS + quicklime (CaO) + calcium chloride (CaCl2)). In the system, the added bottom ash was not simply an inert filler but was dissolved at an early stage. As the ionic concentrations of Ca and Si increased due to dissolved bottom ash, calcium silicate hydrate (C-S-H) formed both earlier and at higher levels, which increased the strength of the earlier stages. However, the added bottom ash did not affect the total quantities of main reaction products, C-S-H and hydrocalumite, in later phases (e.g., 28 days), but simply accelerated the binder reaction until it had occurred for 14 days. After considering both the mechanical strength and the pelletizing formability of all the mixtures, the proportion with 40 relative weight of bottom ash was selected for the manufacturing of pilot samples of aggregates. The produced fine aggregates had a water absorption rate of 9.83% and demonstrated a much smaller amount of heavy metal leaching than the raw bottom ash

    High-performance silicon-based multicomponent battery anodes produced via synergistic coupling of multifunctional coating layers

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    Nanostructured Si-based materials are key building blocks for next-generation energy storage devices. To meet the requirements of practical energy storage devices, Si-based materials should exhibit high-power, low volume change, and high tap density. So far, there have been no reliable materials reported satisfying all of these requirements. Here, we report a novel Si-based multicomponent design, in which the Si core is covered with multifunctional shell layers. The synergistic coupling of Si with the multifunctional shell provides vital clues for satisfying all Si anode requirements for practical batteries. The Si-based multicomponent anode delivers a high capacity of similar to 1000 mA h g(-1), a highly stable cycling retention (similar to 65% after 1000 cycles at 1 C), an excellent rate capability (similar to 800 mA h g(-1) at 10 C), and a remarkably suppressed volume expansion (12% after 100 cycles). Our synthetic process is simple, low-cost, and safe, facilitating new methods for developing electrode materials for practical energy storage.open0

    Protein Translation and Cell Death: The Role of Rare tRNAs in Biofilm Formation and in Activating Dormant Phage Killer Genes

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    We discovered previously that the small Escherichia coli proteins Hha (hemolysin expression modulating protein) and the adjacent, poorly-characterized YbaJ are important for biofilm formation; however, their roles have been nebulous. Biofilms are intricate communities in which cell signaling often converts single cells into primitive tissues. Here we show that Hha decreases biofilm formation dramatically by repressing the transcription of rare codon tRNAs which serves to inhibit fimbriae production and by repressing to some extent transcription of fimbrial genes fimA and ihfA. In vivo binding studies show Hha binds to the rare codon tRNAs argU, ileX, ileY, and proL and to two prophage clusters D1P12 and CP4-57. Real-time PCR corroborated that Hha represses argU and proL, and Hha type I fimbriae repression is abolished by the addition of extra copies of argU, ileY, and proL. The repression of transcription of rare codon tRNAs by Hha also leads to cell lysis and biofilm dispersal due to activation of prophage lytic genes rzpD, yfjZ, appY, and alpA and due to induction of ClpP/ClpX proteases which activate toxins by degrading antitoxins. YbaJ serves to mediate the toxicity of Hha. Hence, we have identified that a single protein (Hha) can control biofilm formation by limiting fimbriae production as well as by controlling cell death. The mechanism used by Hha is the control of translation via the availability of rare codon tRNAs which reduces fimbriae production and activates prophage lytic genes. Therefore, Hha acts as a toxin in conjunction with co-transcribed YbaJ (TomB) that attenuates Hha toxicity

    The Security Weakness of Block Cipher Piccolo against Fault Analysis

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    Piccolo is a 64-bit lightweight block cipher which is able to be implemented in constrained hardware environments such as a wireless sensor network. Fault analysis is a type of side channel attack and cube attack is an algebraic attack finding sufficiently low-degree polynomials in a cipher. In this paper, we show a fault analysis on the Piccolo by using cube attack. We find 16 linear equations corresponding to a round function F by cube attack, which are used to fault analysis. Our attack has the complexity of 2 8.49 and 2 9.21 encryptions with fault injections of target bit positions into Piccolo-80 and Piccolo-128, respectively. And our attack needs 2 20.86 and 2 21.60 encryptions with random 4-bit fault injections for Piccolo-80 and Piccolo-128, respectively
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