1,207 research outputs found

    Impact of current localization on the performance of compact MIMO antennas

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    In this paper, we study the influence of current localization on the isolation between two antennas in a compact terminal setting. The two antennas are chosen to be a monopole and a PIFA. The degree of current localization is controlled by the permittivity value of the PIFA’s dielectric loading. Both lossless and lossy cases are simulated in order to ascertain the underlying performance impact from current localization and its potential use in real implementation. Our results show that significant isolation enhancement is achieved with more localized currents. Moreover, the technique improves the terminal’s diversity and capacity performance both at the center frequency and over a given bandwidth. In addition, PIFAs with dielectric loadings of higher permittivity values and more localized currents are physically smaller. Antenna prototypes are fabricated, and the measured results agree well with the simulated results

    Combination of anti-C1qA08 and anti-mCRP a.a.35-47 antibodies is associated with renal prognosis of patients with lupus nephritis

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    ObjectiveThe aim of this study is to explore the prevalence and clinicopathological associations between anti-C1qA08 antibodies and anti-monomeric CRP (mCRP) a.a.35-47 antibodies and to explore the interaction between C1q and mCRP.MethodsNinety patients with biopsy-proven lupus nephritis were included from a Chinese cohort. Plasma samples collected on the day of renal biopsy were tested for anti-C1qA08 antibodies and anti-mCRP a.a.35-47 antibodies. The associations between these two autoantibodies and clinicopathologic features and long-term prognosis were analyzed. The interaction between C1q and mCRP was further investigated by ELISA, and the key linear epitopes of the combination of cholesterol binding sequence (CBS; a.a.35-47) and C1qA08 were tested by competitive inhibition assays. The surface plasmon resonance (SPR) was used to further verify the results.ResultsThe prevalence of anti-C1qA08 antibodies and anti-mCRP a.a.35-47 antibodies were 50/90 (61.1%) and 45/90 (50.0%), respectively. Levels of anti-C1qA08 antibodies and anti-mCRP a.a.35-47 antibodies were negatively correlated with serum C3 concentrations ((0.5(0.22-1.19) g/L vs. 0.39(0.15-1.38) g/L, P=0.002) and (0.48(0.44-0.88) g/L vs. 0.41(0.15-1.38) g/L, P=0.028), respectively. Levels of anti-C1qA08 antibodies were correlated with the score of fibrous crescents and tubular atrophy (r=-0.256, P=0.014 and r=-0.25, P=0.016, respectively). The patients with double positive antibodies showed worse renal prognosis than that of the double negative group (HR 0.899 (95% CI: 0.739-1.059), P=0.0336). The binding of mCRP to C1q was confirmed by ELISA. The key linear epitopes of the combination were a.a.35-47 and C1qA08, which were confirmed by competitive inhibition experiments and SPR.ConclusionThe combination of anti-C1qA08 and anti-mCRP a.a.35-47 autoantibodies could predict a poor renal outcome. The key linear epitopes of the combination of C1q and mCRP were C1qA08 and a.a.35-47. A08 was an important epitope for the classical pathway complement activation and a.a.35-47 could inhibit this process

    Characteristic mode based tradeoff analysis of antenna-chassis interactions for multiple antenna terminals

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    The design of multiple antennas in compact mobile terminals is a significant challenge, due to both practical and fundamental design tradeoffs. In this paper, fundamental antenna design tradeoffs of multiple antenna terminals are presented in the framework of characteristic mode analysis. In particular, interactions between the antenna elements and the characteristic modes and their impact on design tradeoffs are investigated in both theory and simulations. The results reveal that the characteristic modes play an important role in determining the optimal placement of antennas for low mutual coupling. Moreover, the ability of antenna elements to localize the excitation currents on the chassis can significantly influence the final performance. To demonstrate the effectiveness of the proposed approach, a dual-band, dual-antenna terminal is designed to provide an isolation of over 10 dB for the 900 MHz band without additional matching or decoupling structures. A tradeoff analysis of bandwidth, efficiency, effective diversity gain and capacity is performed over different antenna locations. Finally, three fabricated prototypes verify the simulation results for representative cases

    Cross-linked CoMoO4/rGO nanosheets as oxygen reduction catalyst

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    Development of inexpensive and robust electrocatalysts towards oxygen reduction reaction (ORR) is crucial for the cost-affordable manufacturing of metal-air batteries and fuel cells. Here we show that cross-linked CoMoO4 nanosheets and reduced graphene oxide (CoMoO4/rGO) can be integrated in a hybrid material under one-pot hydrothermal conditions, yielding a composite material with promising catalytic activity for oxygen reduction reaction (ORR). Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to investigate the efficiency of the fabricated CoMoO4/rGO catalyst towards ORR in alkaline conditions. The CoMoO4/rGO composite revealed the main reduction peak and onset potential centered at 0.78 and 0.89 V (vs. RHE), respectively. This study shows that the CoMoO4/rGO composite is a highly promising catalyst for the ORR under alkaline conditions, and potential noble metal replacement cathode in fuel cells and metal-air batteries

    Transcriptome profile of the human endothelial cell response to high- and low-density infections of Candida albicans

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    Background: Candida albicans morphology switching and quorum-sensing are important factors for pathogenicity and virulence in persons with a compromised or deficient immune system. This study investigates the in vitro response of human umbilical vein endothelial cells (HUVECs) to infections with low and high densities of C. albicans. We hypothesize that higher cell densities of C. albicans yeast-form cells (blastospores), are more detrimental to HUVECs than lower cell densities of hyphal forms. Methods: Three biological replicates of confluent HUVECs in 6-well plates were challenged with 106 C. albicans blastospores (low-density infection) and 5 x 107 blastospores (highdensity infection) for 8 hours. The low-density infection generated true hyphae, but in the high-density infection, C. albicans remained as blastospores. RNA from these samples were subjected to DNA microarray transcript profiling. For MTT and XTT cell proliferation assays, conditioned media from the co-cultures for microarray experiments were incubated with HUVECs in 96-well plates for 24 hours. Results: The high-density blastospore-HUVEC co-cultures elicited significantly higher differential expression of genes involved in functional pathways of apoptosis, immune response, cell-cell signaling and cancer development, such as ZC3HAV1, HES1, CSF2, CXCL2 and PIM1, compared to the low-density true hyphae-HUVEC co-cultures. Cell proliferation assays also show that HUVECs incubated with conditioned media from the highdensity infection caused a higher percentage of cell death compared to incubation with conditioned media from the low-density infection. These results suggest that high densities of unattenuated, innate C. albicans blastospore cells can cause significant cellular toxicity, even though the cells are in the yeast form, not filamentous. Conclusion: Transcript profiling of this in vitro endothelial cell model may provide new insights into how C. albicans cell densities affect the host during the colonization and invasion through the bloodstream to the deep organs. We also suggest that quorum-sensing molecules and other unknown secretions from high-density C. albicans infections are strong inducers of cellular injury leading to cell death in systemic candidiasis

    Towards Sustainable Ultrawide Bandgap Van der Waals Materials: An ab initio Screening Effort

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    The sustainable development of next-generation device technology is paramount in the face of climate change and the looming energy crisis. Tremendous efforts have been made in the discovery and design of nanomaterials that achieve device-level sustainability, where high performance and low operational energy cost are prioritized. However, many of such materials are composed of elements that are under threat of depletion and pose elevated risks to the environment. The role of material-level sustainability in computational screening efforts remains an open question thus far. Here we develop a general van der Waals materials screening framework imbued with sustainability-motivated search criteria. Using ultrawide bandgap (UWBG) materials as a backdrop -- an emerging materials class with great prospects in dielectric, power electronics, and ultraviolet device applications, we demonstrate how this screening framework results in 25 sustainable UWBG layered materials comprising only of low-risks elements. Our findings constitute a critical first-step towards reinventing a more sustainable electronics landscape beyond silicon, with the framework established in this work serving as a harbinger of sustainable 2D materials discovery.Comment: 15 pages, 8 figure

    Enhancing Mentoring in Palliative Care: An Evidence Based Mentoring Framework

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    Background: Growing concerns over ethical issues in mentoring in medicine and surgery have hindered efforts to reinitiate mentoring for Palliative Care (PC) physicians following the easing of COVID-19 restrictions. Ranging from the misappropriation of mentee’s work to bullying, ethical issues in mentoring are attributed to poor understanding and structuring of mentoring programs, underlining the need for a consistent approach to mentoring practices. Methods: Given diverse practices across different settings and the employ of various methodologies, a novel approach to narrative reviews (NR)s is proposed to summarize, interpret, and critique prevailing data on novice mentoring. To overcome prevailing concerns surrounding the reproducibility and transparency of narrative reviews, the Systematic Evidenced Based Approach (SEBA) adopts a structured approach to searching and summarizing the included articles and employed concurrent content and thematic analysis that was overseen by a team of experts. Results: A total of 18 915 abstracts were reviewed, 62 full text articles evaluated and 41 articles included. Ten themes/categories were ascertained identified including Nature; Stakeholders; Relationship; Approach; Environment; Benefits; Barriers; Assessments; Theories and Definitions. Conclusion: By compiling and scrutinizing prevailing practice it is possible to appreciate the notion of the mentoring ecosystem which sees each mentee, mentor, and host organization brings with them their own microenvironment that contains their respective goals, abilities, and contextual considerations. Built around competency based mentoring stages, it is possible to advance a flexible yet consistent novice mentoring framework. </jats:sec
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