359 research outputs found
An Ensemble Learning for Predicting Breakdown Field Strength of Polyimide Nanocomposite Films
Using the method of Stochastic Gradient Boosting, ten SMO-SVR are constructed into a strong prediction model (SGBS model) that is efficient in predicting the breakdown field strength. Adopting the method of in situ polymerization, thirty-two samples of nanocomposite films with different percentage compositions, components, and thicknesses are prepared. Then, the breakdown field strength is tested by using voltage test equipment. From the test results, the correlation coefficient (CC), the mean absolute error (MAE), the root mean squared error (RMSE), the relative absolute error (RAE), and the root relative squared error (RRSE) are 0.9664, 14.2598, 19.684, 22.26%, and 25.01% with SGBS model. The result indicates that the predicted values fit well with the measured ones. Comparisons between models such as linear regression, BP, GRNN, SVR, and SMO-SVR have also been made under the same conditions. They show that CC of the SGBS model is higher than those of other models. Nevertheless, the MAE, RMSE, RAE, and RRSE of the SGBS model are lower than those of other models. This demonstrates that the SGBS model is better than other models in predicting the breakdown field strength of polyimide nanocomposite films
Essential role of microglia in the fast antidepressant action of ketamine and hypidone hydrochloride (YL-0919)
Introduction: Intracerebral microglia play a vital role in mediating central immune response, neuronal repair and synaptic pruning, but its precise role and mechanism in fast action of antidepressants have remained unknown. In this study, we identified that the microglia contributed to the rapid action of antidepressants ketamine and YL-0919.Methods: The depletion of microglia was achieved with the diet containing the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 in mice. The tail suspension test (TST), forced swimming test (FST) and novelty suppressed feeding test (NSFT) were employed to evaluate the rapid acting antidepressant behavior of ketamine and YL-0919 in the microglia depletion model. The number of microglia in the prefrontal cortex (PFC) was assayed by the immunofluorescence staining. The expressions of synaptic proteins (synapsin-1, PSD-95, GluA1) and brain-derived neurotrophic factor (BDNF) in the PFC were tested by Western blot.Results: The immobility duration in FST and the latency to feed in NSFT were shortened 24 h after an intraperitoneal (i.p.) injection of ketamine (10 mg/kg). The microglial depletion of PLX3397 blocked the rapid antidepressant-like effect of ketamine in mice. In addition, the immobility time in TST and FST as well as latency to feed in NSFT were reduced 24 h after the intragastric (i.g.) administration of YL-0919 (2.5 mg/kg, administered for 5–6 consecutive days), and the rapid antidepressant effect of YL-0919 was also blocked by the microglial depletion using PLX5622. About 92% of microglia in the prefrontal cortex was depleted in PLX5622 diet-fed mice, while both ketamine and YL-0919 promoted proliferation on the remaining microglia. YL-0919 significantly increased the protein expressions of synapsin-1, PSD-95, GluA1 and BDNF in the PFC, all of which could be blocked by PLX5622.Conclusion: These results suggested the microglia underlying the rapid antidepressant-like effect of ketamine and YL-0919, and microglia would likely constitute in the rapid enhancing impact of synaptic plasticity in the prefrontal cortex by YL-0919
LightDAG: A Low-latency DAG-based BFT Consensus through Lightweight Broadcast
To improve the throughput of Byzantine Fault Tolerance (BFT) consensus protocols, the Directed Acyclic Graph (DAG) topology has been introduced to parallel data processing, leading to the development of DAG-based BFT consensus. However, existing DAG-based works heavily rely on Reliable Broadcast (RBC) protocols for block broadcasting, which introduces significant latency due to the three communication steps involved in each RBC. For instance, DAGRider, a representative DAG-based protocol, exhibits a best latency of 12 steps, considerably higher than non-DAG protocols like PBFT, which only requires 3 steps. To tackle this issue, we propose LightDAG, which replaces RBC with lightweight broadcasting protocols such as Consistent Broadcast (CBC) and Plain Broadcast (PBC). Since CBC and PBC can be implemented in two and one communication steps, respectively, LightDAG achieves low latency.
In our proposal, we present two variants of LightDAG, namely LightDAG1 and LightDAG2, each providing a trade-off between the best latency and the expected worst latency. In LightDAG1, every block is broadcast using CBC, which exhibits a best latency of 5 steps and an expected worst latency of 14 steps. Since CBC cannot guarantee the totality property, we design a block retrieval mechanism in LightDAG1 to assist replicas in retrieving missing blocks. LightDAG2 utilizes a combination of PBC and CBC for block broadcasting, resulting in a best latency of 4 steps and an expected worst latency of steps, where represents the number of actual Byzantine replicas. Since a Byzantine replica may equivocate through PBC, LightDAG2 prohibits blocks from directly referencing contradictory blocks. To ensure liveness, we propose a mechanism to identify and exclude Byzantine replicas if they engage in equivocation attacks. Extensive experiments have been conducted to evaluate LightDAG, and the results demonstrate its feasibility and efficiency
Surface density-of-states on semi-infinite topological photonic and acoustic crystals
Iterative Green's function, based on cyclic reduction of block tridiagonal
matrices, has been the ideal algorithm, through tight-binding models, to
compute the surface density-of-states of semi-infinite topological electronic
materials. In this paper, we apply this method to photonic and acoustic
crystals, using finite-element discretizations and a generalized eigenvalue
formulation, to calculate the local density-of-states on a single surface of
semi-infinite lattices. The three-dimensional (3D) examples of gapless
helicoidal surface states in Weyl and Dirac crystals are shown and the
computational cost, convergence and accuracy are analyzed.Comment: 7 pages, 4 figure
Characterization of mycotoxins and microbial community in whole-plant corn ensiled in different silo types during aerobic exposure
Silage can be contaminated with mycotoxins and accidental fungi after aerobic exposure. The study assessed the effects of bunker silos (BS), round bales (RB), and silage bags (SB) on the nutritional characteristics, fermentation quality, aerobic stability, mycotoxin levels and microbial communities of whole-plant corn silage (WPCS). After 90 days of fermentation, silages were opened and sampled at 0, 1, 3, 5, 7, and 9 days of exposure. SB group conserved higher lactic acid and dry matter contents and a lower pH value than other groups after 9 days of exposure (p < 0.05). The SB group showed the longest aerobic stability (202 h) among all silages (p < 0.05). The concentrations of aflatoxin B1, trichothecenes and fumonisin B1 were significantly lower in SB after 9 days of exposure (p < 0.05). Acetobacter became the dominant bacteria in BS and RB groups after 5 days of exposure. However, Lactobacillus still dominated the bacterial community in SB group. Acetobacter was positively correlated with pH, acetic acid content, and ammonia-N content (p < 0.05). Lactobacillus was positively correlated with Kazachstania and Candida abundances (p < 0.01) but negatively correlated with Fusarium abundance (p < 0.05). Considering the feed value and food safety of silage in the feeding process, silage bags are recommended for WPCS according to the observed nutritional quality, fermentation index and mycotoxin content
SARS-CoV-2 Causes a Significant Stress Response Mediated by Small RNAs in the Blood of COVID-19 Patients
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a serious impact on the world. In this study, small RNAs from the blood of COVID-19 patients with moderate or severe symptoms were extracted for high-throughput sequencing and analysis. Interestingly, the levels of a special group of tRNA-derived small RNAs (tsRNAs) were found to be dramatically upregulated after SARS-CoV-2 infection, particularly in coronavirus disease 2019 (COVID-19) patients with severe symptoms. In particular, the 3′CCA tsRNAs from tRNA-Gly were highly consistent with the inflammation indicator C-reactive protein (CRP). In addition, we found that the majority of significantly changed microRNAs (miRNAs) were associated with endoplasmic reticulum (ER)/unfolded protein response (UPR) sensors, which may lead to the induction of proinflammatory cytokine and immune responses. This study found that SARS-CoV-2 infection caused significant changes in the levels of stress-associated small RNAs in patient blood and their potential functions. Our research revealed that the cells of COVID-19 patients undergo tremendous stress and respond, which can be reflected or regulated by small non-coding RNA (sncRNAs), thus providing potential thought for therapeutic intervention in COVID-19 by modulating small RNA levels or activities
Possible Origin of the Damocloids:the Scattered Disk or a New Region?
The Damocloids are a group of unusual asteroids, recently enrolling a new
member of 2010 EJ104. The dynamical evolution for the Damocloids may uncover a
connection passage from the Main Belt, the Kuiper Belt and the scattered disk
beyond. According to our simulations, two regions may be considered as possible
origin of the Damocloids: the scattered disk, or a part of Oort cloud which
will be perturbed to a transient region locating between 700 AU and 1000 AU.
Based on the potential origin, the Damocloids can be classified into two types,
with relation to their semi-major axes, and about 65.5% Damocloids is
classified into type I which mainly originate from Oort cloud. Whether the
Damocloids is inactive nuclei of Halley Family Comets may rely on their origin.Comment: 10 pages, 5 figures, accepted for publication in Research in
Astronomy and Astrophysic
Titanium Nitride Film on Sapphire Substrate with Low Dielectric Loss for Superconducting Qubits
Dielectric loss is one of the major decoherence sources of superconducting
qubits. Contemporary high-coherence superconducting qubits are formed by
material systems mostly consisting of superconducting films on substrate with
low dielectric loss, where the loss mainly originates from the surfaces and
interfaces. Among the multiple candidates for material systems, a combination
of titanium nitride (TiN) film and sapphire substrate has good potential
because of its chemical stability against oxidization, and high quality at
interfaces. In this work, we report a TiN film deposited onto sapphire
substrate achieving low dielectric loss at the material interface. Through the
systematic characterizations of a series of transmon qubits fabricated with
identical batches of TiN base layers, but different geometries of qubit
shunting capacitors with various participation ratios of the material
interface, we quantitatively extract the loss tangent value at the
substrate-metal interface smaller than in 1-nm disordered
layer. By optimizing the interface participation ratio of the transmon qubit,
we reproducibly achieve qubit lifetimes of up to 300 s and quality factors
approaching 8 million. We demonstrate that TiN film on sapphire substrate is an
ideal material system for high-coherence superconducting qubits. Our analyses
further suggest that the interface dielectric loss around the Josephson
junction part of the circuit could be the dominant limitation of lifetimes for
state-of-the-art transmon qubits
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