1,782 research outputs found

    Information-Theoretic Limits of Bistatic Integrated Sensing and Communication

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    The bistatic integrated sensing and communication (ISAC) system model avoids the strong self-interference in a monostatic ISAC system by employing a pair of physically separated sensing transceiver and maintaining the merit of co-designing radar sensing and communications on shared spectrum and hardware. Inspired by the appealing benefits of bistatic radar, we study bistatic ISAC, where a transmitter sends a message to a communication receiver and a sensing receiver at another location carries out a decoding-and-estimation(DnE) operation to obtain the state of the communication receiver. In this paper, both communication and sensing channels are modelled as state-dependent memoryless channels with independent and identically distributed time-varying state sequences. We consider a rate of reliable communication for the message at the communication receiver as communication metric. The objective of this model is to characterize the capacity-distortion region, i.e., the set of all the achievable rate while simultaneously allowing the sensing receiver to sense the state sequence with a given distortion threshold. In terms of the decoding degree on this message at the sensing receiver, we propose three achievable DnE strategies, the blind estimation, the partial-decoding-based estimation, and the full-decoding-based estimation, respectively. Based on the three strategies, we derive the three achievable rate-distortion regions. In addition, under the constraint of the degraded broadcast channel, i.e., the communication receiver is statistically stronger than the sensing receiver, and the partial-decoding-based estimation, we characterize the capacity region. Examples in both non-degraded and degraded cases are provided to compare the achievable rate-distortion regions under three DnE strategies and demonstrate the advantages of ISAC over independent communication and sensing.Comment: 40 pages, 7 figure

    A transformative route to nanoporous manganese oxides of controlled oxidation states with identical textural properties

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    Nanoporous nanocrystalline metal oxides with tunable oxidation states are crucial for controlling their catalytic, electronic, and optical properties. However, previous approaches to modulate oxidation states in nanoporous metal oxides commonly lead to the breakdown of the nanoporous structure as well as involve concomitant changes in their morphology, pore size, surface area, and nanocrystalline size. Herein, we present a transformative route to nanoporous metal oxides with various oxidation states using manganese oxides as model systems. Thermal conversion of Mn-based metal-organic frameworks (Mn-MOFs) at controlled temperature and atmosphere yielded a series of nanoporous manganese oxides with continuously tuned oxidation states: MnO, Mn3O 4, Mn5O8, and Mn2O3. This transformation enabled the preparation of low-oxidation phase MnO and metastable intermediate phase Mn5O8 with nanoporous architectures, which were previously rarely accessible. Significantly, nanoporous MnO, Mn3O4, and Mn5O8 had a very similar morphology, surface area, and crystalline size. We investigated the electrocatalytic activity of nanoporous manganese oxides for oxygen reduction reaction (ORR) to identify the role of oxidation states, and observed oxidation state-dependent activity and kinetics for the ORR.close5

    An Earlier Predictive Rollover Index Designed for Bus Rollover Detection and Prevention

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    As vehicle rollovers annually cause a great deal of traffic-related deaths, an increasing number of vehicles are being equipped with rollover prevention systems with the aim of avoiding such accidents. To improve the functionality of active rollover prevention systems, this study provided a potential enhanced method with the intention to predict the tendency of the lateral load transfer ratio (LTR), which is the most common rollover index. This will help provide a certain amount of lead time for the control system to respond more effectively. Before the prediction process, an estimation equation was proposed to better estimate the LTR; the equation was validated using Simulink and TruckSim. Further, to eliminate the influence of drawbacks and make this method practical, a buffer operator was added. Simulation results showed that grey LTR (GLTR) was able to roundly predict the future trend of the LTR based on current and previous data. Under the tests of “Sine with Dwell” (Sindwell) and double lane change (DLC), the GLTR could provide the control system with sufficient time beforehand. Additionally, to further examine the performance of the GLTR, a differential system model was adopted to verify its effectiveness. Through the Sindwell maneuver, it was demonstrated that the GLTR index could improve the performance of the rollover prevention systems by achieving the expected response. Document type: Articl

    Gallic acid ameliorates dextran sulfate sodium-induced ulcerative colitis in mice via inhibiting NLRP3 inflammasome

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    Background: Ulcerative colitis (UC) is a chronic recurrent inflammatory bowel disease (IBD). The conventional drugs for UC may induce severe side effects. Herbal medicine is considered as a complementary and alternative choice for UC.Purpose: This study aims to estimate the effect of natural polyphenol gallic acid (GA) on the NLRP3 inflammasome with dextran sulfate sodium (DSS)-induced colitis in mice.Study design: The body weights and symptoms of BALB/c mice were recorded. Histological evaluation, ELISA, q-PCR, immunohistochemistry, and western blotting were carried out to observe the morphology, cytokine contents, mRNA expressions, and protein expressions, respectively. Lipopolysaccharide (LPS)-induced RAW264.7 macrophage was used to probe GA’s effect on relative protein expression.Results: GA attenuated weight loss (p < 0.05), relieved symptoms, and ameliorated colonic morphological injury (p < 0.05) in mice with colitis induced by DSS. GA also lowered the contents of TNF-α, IL-1β, IL-18, IL-33, and IFN-γ in the serum and colon of mice, which were elevated by DSS, downregulated protein, and mRNA expressions of the NLRP3 pathway in the colon tissue. Furthermore, GA downregulated the expressions of NLRP3 (p < 0.05), iNOS (p < 0.01), COX2 (p < 0.01), and P-p65 (p < 0.05), and suppressed NO release (p < 0.001) in LPS-induced RAW264.7 cells.Conclusion: GA ameliorated DSS-induced UC in mice via inhibiting the NLRP3 inflammasome. These findings furnish evidence for the anti-inflammatory effect of herbal medicines containing GA on UC

    In Vitro

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    A high-throughput method was developed and applied to screen for the active antihepatic steatosis components within Coptidis Rhizoma Alkaloids Extract (CAE). This method was a combination of two previously described assays: HepG2 cell extraction with HPLC analysis and a free fatty acid-induced (FFA) hepatic steatosis HepG2 cell assay. Two alkaloids within CAE, berberine and coptisine, were identified by HepG2 cell extraction with HPLC analysis as high affinity components for HepG2. These alkaloids were also determined to be active and potent compounds capable of lowering triglyceride (TG) accumulation in the FFA-induced hepatic steatosis HepG2 cell assay. This remarkable inhibition of TG accumulation (P < 0.01) by berberine and coptisine occurred at concentrations of 0.2 μg/mL and 5.0 μg/mL, respectively. At these concentrations, the effect seen was similar to that of a CAE at 100.0 μg/mL. Another five alkaloids within CAE, palmatine, epiberberine, jateorhizine, columbamine, and magnoline, were found to have a lower affinity for cellular components from HepG2 cells and a lower inhibition of TG accumulation. The finding of two potent and active compounds within CAE indicates that the screening method we developed is a feasible, rapid, and useful tool for studying traditional Chinese medicines (TCMs) in treating hepatic steatosis

    Increased Frequency of Circulating Follicular Helper T Cells in Patients with Rheumatoid Arthritis

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    Follicular helper T (Tfh) cells are recognized as a distinct CD4+ helper T-cell subset, which provides for B-cell activation and production of specific antibody responses, and play a critical role in the development of autoimmune disease. So far, only one study investigated the circulating Tfh cells increased in a subset of SLE patients. Since relatively little is known about the Tfh cells in rheumatoid arthritis (RA) patients, in this study, Tfh-cell frequency, related cytokine IL-21, and transcription factor Bcl-6 were investigated in 53 patients with RA and 31 health controls. Firstly, we found that the frequency of CD4+CXCR5+ICOShigh Tfh cells was increased significantly in the peripheral blood of RA patients, compared with that in healthy controls. It is known that Tfh cells are critical for directing the development of an antibody response by germinal centers B cells; secondly, we observed that the Tfh-cell frequency is accompanied by the level of anti-CCP antibody in RA patients. Furthermore, expression of Bcl-6 mRNA and plasma IL-21 concentrations in RA patients was increased. Taken together, these findings have shown that the increased frequency of circulating Tfh cells is correlated with elevated levels of anti-CCP antibody, indicating the possible involvement of Tfh cells in the disease progression of RA
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