Solving multi-scale low frequency electromagnetic problems

In this paper, we will discuss two methods to tackle the low-frequency, multi-scale electromagnetics problem. First we will discuss the augmented electric field integral equation (AEFIE), and then, we will discuss the equivalence principle algorithm (EPA). The AEFIE allows the solution of such problems without the need to perform a loop search of a complex structure. The EPA allows the separation of circuit physics from wave physics in a multiscale problem. Hybridization of these two methods will be discussed.published_or_final_versionThe 4th European Conference on Antennas and Propagation (EuCAP) 2010, Barcelona, Spain, 12-16 April 2010. In Proceedings of the 4th EuCAP, 2010, p. 1-

Effectively predicting whether and when a topic will become prevalent in a social network

Copyright © 2015, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved. Effective forecasting of future prevalent topics plays an important role in social network business development. It involves two challenging aspects: predicting whether a topic will become prevalent, and when. This cannot be directly handled by the existing algorithms in topic modeling, item recommendation and action forecasting. The classic forecasting framework based on time series models may be able to predict a hot topic when a series of periodical changes to user-addressed frequency in a systematic way. However, the frequency of topics discussed by users often changes irregularly in social networks. In this paper, a generic probabilistic framework is proposed for hot topic prediction, and machine learning methods are explored to predict hot topic patterns. Two effective models, PreWHether and PreWHen, are introduced to predict whether and when a topic will become prevalent. In the PreWHether model, we simulate the constructed features of previously observed frequency changes for better prediction. In the PreWHen model, distributions of time intervals associated with the emergence to prevalence of a topic are modeled. Extensive experiments on real dataseis demonstrate that our method outperforms the baselines and generates more effective predictions

Revealing microstructural evolutions, mechanical properties and wear performance of wire arc additive manufacturing homogeneous and heterogeneous NiTi alloy

Heterogeneous microstructure designs have attracted a great deal of attention, not only because they have the potential to achieve an ideal combination of two conflicting properties, but also because the processes involved in their fabrication are cost-effective and can be scaled up for industrial production. The process parameters in the preparation process have an important effect on the microstructure and properties of alloy members prepared by wire arc additive manufacturing (WAAM) technology. It was expected that the spatial heterogeneous microstructure with large microstructural heterogeneities in metals can be formed through changing the process parameters. In this work, homogeneous NiTi thin-walled component and heterogeneous NiTi thin-walled component were fabricated using WAAM technology by adjusting the heat input. The effects of deposition height and heat input on the microstructure, mechanical properties and wear properties of WAAM NiTi alloys were investigated. The results show that grains were gradually refined with the increase of deposition height in the homogeneous WAAM NiTi component. The ultimate tensile strength of homogeneous WAAM NiTi component increased from 606.87 MPa to 654.45 MPa and the elongation increased from 12.72% to 15.38%, as the increase of deposition height. Moreover, the homogeneous WAAM NiTi component exhibited excellent wear resistance, the coefficient of friction decreased from 0.760 to 0.715 with the increase of deposition height. Meanwhile, the grains in the heterogeneous WAAM NiTi component shows the finest grains in the central region. The ultimate tensile strength of the lower region, middle region and upper region of heterogeneous WAAM NiTi components were 556.12 MPa, 599.53 MPa and 739.79 MPa, and the elongations were 12.98%, 16.69%, 21.74%, respectively. The coefficient of friction for the lower region, middle region and upper region of heterogeneous WAAM NiTi components were 0.713, 0.720 and 0.710, respectively. The microhardness and cyclic compression properties of the homogeneous components with higher heat input were better than those of the heterogeneous components for the same deposition height. The tensile yield strength, elongation and wear resistance of the heterogeneous components were superior compared to the homogeneous components. These results can be used to optimize the WAAM process parameters to prepare NiTi components with excellent mechanical properties

Selective nitrogen adsorption via backbonding in a metal-organic framework with exposed vanadium sites.

Industrial processes prominently feature π-acidic gases, and an adsorbent capable of selectively interacting with these molecules could enable important chemical separations1-4. Biological systems use accessible, reducing metal centres to bind and activate weakly π-acidic species, such as N2, through backbonding interactions5-7, and incorporating analogous moieties into a porous material should give rise to a similar adsorption mechanism for these gaseous substrates8. Here, we report a metal-organic framework featuring exposed vanadium(II) centres capable of back-donating electron density to weak π acids to successfully target π acidity for separation applications. This adsorption mechanism, together with a high concentration of available adsorption sites, results in record N2 capacities and selectivities for the removal of N2 from mixtures with CH4, while further enabling olefin/paraffin separations at elevated temperatures. Ultimately, incorporating such π-basic metal centres into porous materials offers a handle for capturing and activating key molecular species within next-generation adsorbents

Hepatitis B Virus Core Promoter Double Mutations (A1762T, G1764A) Are Associated with Lower Levels of Serum Dihydrolipoyl Dehydrogenase

Published by S. Karger AG, BaselObjectives: The aim of this study was to identify serum proteins with differential concentrations between hepatocellular carcinoma (HCC) patients and HBsAg asymptomatic carriers among individuals infected with hepatitis B virus (HBV) with basal core promoter (BCP) double mutations (A1762T, G1764A). Methods: iTRAQ and liquid chromatography-tandem mass spectrometry were used to identify differentially expressed protein, and an ELISA test was used for the validation test. Results: The total number of proteins identified was 1,125, of which 239 showed statistically significant differences in their expression. The relative concentrations of serum dihydrolipoyl dehydrogenase (DLD), which showed the most significant correlation with liver diseases and infection, were significantly lower in HCC patients than asymptomatic HBsAg carriers and individuals negative for HBsAg. However, only the difference between HCC patients with BCP double mutations and HBsAg-negative individuals could be confirmed by ELISA. Meanwhile, we found that the concentrations of serum DLD in those infected with HBV with BCP double mutations were significantly lower than in individuals with the wild-type BCP. However, the difference in the concentrations of serum DLD between individuals with wild-type BCP and those negative for HBsAg was not significant. Conclusions: HBV with BCP double mutations are associated with lower concentrations of serum DLD

FasL expression on human nucleus pulposus cells contributes to the immune privilege of intervertebral disc by interacting with immunocytes

The mechanisms of immune privilege in human nucleus pulposus (NP) remain unclear. Accumulating evidence indicates that Fas ligand (FasL) might play an important role in the immune privilege of the disc. We aimed for addressing the role of FasL expression in human intervertebral disc degeneration (IDD) and immune privilege in terms of the interaction between NP cells and immunocytes via the FasL-Fas machinery. We collected NP specimens from 20 patients with IDD as degenerative group and 8 normal cadaveric donors as control. FasL expression was detected by qRT-PCR, western blotting and flow cytometry (FCM). We also collected macrophages and CD8(+) T cells from the peripheral blood of patients with IDD for co-cultures with NP cells. And macrophages and CD8(+) T cells were harvested for apoptosis analysis by FCM after 2 days of co-cultures. We found that FasL expression in mRNA, protein and cellular resolutions demonstrated a significant decrease in degenerative group compared with normal control (p<0.05). FCM analysis found that human NP cells with increased FasL expression resulted in significantly increased apoptosis ratio of macrophages and CD8(+) T cells. Our study demonstrated that FasL expression tends to decrease in degenerated discs and FasL plays an important role in human disc immune privilege, which might provide a novel target for the treatment strategies for IDD.published_or_final_versio

Microstructures and resistivity of cuprate/manganite bilayer deposited on SrTiO3 substrate

Thin Yba[SUB2]Cu[SUB3]O[SUB7-δ/La[SUB0.67]Ca[SUB0.33]MnO[SUB3] (YBCO/LCMO) films were grown on SrTiO[SUB3](STO)substrates by magnetron sputtering technique. The microstructures of the bilayers were characterized and a standard four-probe technique was applied to measure the resistivity of the samples. The interdiffusions at the YBCO/LCMO and LCMO/STO interfaces formed two transient layers with the thickness of about 3 and 2 nm, respectively. All the bilayers were well textured along the c axis. At low temperature, the superconductivity can only be observed when the thickness of YBCO is more than 25 nm. When the thickness of YBCO is less than 8 nm, the bilayers show only ferromagnetism. The superconductivity and ferromagnetism perhaps coexist in the bilayer with the YBCO thickness of 12.5 nm. These interesting properties are related to the interaction between spin polarized electrons in the manganites and the cooper pairs in the cuprates. © 2003 American Institute of Physics.published_or_final_versio

Review of multi-scale electromagnetic modeling

This paper reviews various methods to solve multiscale problems ranging from low-frequency methods to very high-frequency methods. ©2010 IEEE.published_or_final_versionThe 2010 International Conference on Electromagnetics in Advanced Applications (ICEAA), Sydney, N.S.W., 20-24 September 2010. In Proceedings of ICEAA'10, 2010, p. 641-64

Evaluation of tumor response to cytokine-induced killer cells therapy in malignant solid tumors

CIK cells therapy has been evaluated as an adoptive cell immunotherapy for cancer patients, but there still have not been any standardized systems for evaluating the antitumor efficacy yet. The WHO and RECIST criteria have already been established for a few years but not sufficient to fully characterize the activity of immunotherapy. Based on these two criteria, the irRC was proposed for evaluating the efficacy of immunotherapy. A variety of bioassays for immune monitoring including the specific and non-specific methods, have been established. We recommend detect levels of various immunocytes, immune molecules and soluble molecules to find the correlations among them and clinicopathological characteristics to establish criteria for immunological classification. We also recommend a paradigm shift for the oncologists in the evaluation of immune therapies to ensure assessment of activity based on clinically relevant criteria and time points