Methods for fast evaluation of self-energy matrices in tight-binding modeling of electron transport systems

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Efficient simulation and analysis of quantum ballistic transport in nanodevices with AWE

Quantum-mechanical modeling of ballistic transport in nanodevices usually requires solving the Schrdinger equation at multiple energy points within an energy band. To speed up the simulation and analysis, the asymptotic waveform evaluation is introduced in this paper. Using this method, the wave function is only rigorously solved at several sampled energy points, whereas those at other energies are computed through Pad approximation. This allows us to obtain the physical quantities over the whole energy band with very little computational cost. In addition, the accuracy is controllable by a complex frequency hopping algorithm. The validity and efficiency of the proposed method are demonstrated by detailed study of several multigate silicon nano-MOSFETs. © 2006 IEEE.published_or_final_versio

NKG2D-dependent cross talk between NK cells and CD4 T cells in chronic hepatitis B

NK cells are emerging as potent regulators of adaptive immunity in virus infection. Our group recently documented the partially TRAIL-dependent deletion of HBV-specific T cells by NK cells. For this study, we investigated the underlying interactions between NK cells and T cells through the NKG2D pathway in chronic HBV infection. In this study, we observed that activated and HBV-specific T cells, especially the CD4 fraction, expressed NKG2D ligands (NKG2D-L) not normally seen on T cells. NKG2D-L upregulation was further enriched on CD4 T cells in HBV-infected livers compared to the circulation and control livers. Oxidative stress, one noteworthy pathogenic feature of HBV infection, was demonstrated to recapitulate the T cell NKG2D-L upregulation pattern seen in patients with chronic hepatitis B (CHB). NK cells from patients with CHB maintained NKG2D expression and their increased activation and cytotoxicity could be driven by NKG2D-L expressing cells. In line with the distinctive features of T cells and NK cells in CHB, we discovered a positive correlation between activation of NKG2D+NK cells and the NKG2D-L (MICA/B) levels on CD4 T cells. Additionally, the pro-inflammatory cytokine IFN-α, used in HBV treatment, was shown to favour for NKG2D-mediated regulation. To conclude, we provide the first ex vivo evidence that human T cells, particularly those sequestered within tissues, can become visible to the stress surveillance system by the induction of NKG2D-L. We show that in active CHB, T cells upregulate NKG2D-L which can drive NK cell activation and cytotoxicity via the NKG2D pathway. These interactions may be triggered by aberrant oxidative stress and result in a homeostatic response of "damage removal", thereby limiting T cell antiviral immunity. Therefore, efforts to manipulate the HBV-infected liver milieu in order to decrease T cell oxidative stress and diminish constraints from NK cells and the NKG2D pathway should be considered to reduce HBV pathogenesis and promote immunity

Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) ≤70% and FEV(1) less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction

A comparison of the in- and out-patient referral patterns of four tertiary rheumatology centres in Beijing, Hong Kong, Kaohsiung and Los Angeles

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Finite element based generalized impedance boundary condition for complicated em calculation

In this paper, a finite element based generalized impedance boundary condition (FEM-GIBC) is proposed to solve complicated electromagnetic (EM) problems. Complex structures with arbitrary inhomogeneity and shapes are modeled with the finite element method, and their scattering contributions are transformed to generalized impedance conditions on their boundaries. For each sub-domain, a special GIBC can be established and it is only related to the structures in this domain. Hence, for finite periodic structures, a representative GIBC can be formulated at the boundary of a unit cell. After the GIBC at each boundary is established, the electromagnetic coupling between each impedance boundary can be calculated by the boundary integral equations (BIE) and accelerated with the multilevel fast multipole algorithm (MLFMA). © 2011 IEEE.published_or_final_versionThe 2011 IEEE International Symposium on Antennas and Propagation (APSURSI), Spokane, WA., 3-8 July 2011. In IEEE APSURSI Digest, 2011, p. 2700-270

Progenitor-like cells derived from mouse kidney protect against renal fibrosis in a remnant kidney model via decreased endothelial mesenchymal transition

Showing A quantification of GFP-positive cells in the lung after intravenous injection of MKPCs in five-sixths nephrectomized mice (y axis shows the number of cells, while the x axis (FL1-H) shows the fluorescence intensity; M1 is the area of GFP-positive cells) and B immunohistochemistry of the lung after intravenous injection of MKPCs into a mouse that underwent five-sixths nephrectomy. Few GFP positive cells were found in the lung at the first day but there were no GFP-positive cells at week 14. (TIFF 2253 kb

A pancake-shaped nano-aggregate for focusing surface plasmons

We proposed a pancake-shaped nano-aggregate that highly focuses surface plasmons. The structure is a superposition of bowtie-shaped dimers, where surface plasmons are excited, resonated with the structure, and coupled. Surface integral equation method (Poggio-Miller-Chang-Harrington-Wu-Tsai method) is used to predict the performance of the proposed structure. It is a method which can accurately calculate the near-fields of nanoparticles. Based on the numerical prediction, the proposed structure shows an electric field (E-field) enhancement of more than 400 times, which is equivalent to a Raman enhancement factor of more than 2.5 e 10 times. It is promising for single molecule detections using surface-enhanced Raman scattering. The physics of the proposed structure are revealed. It is useful to design nanostructures for high E-field enhancement. © 2012 American Institute of Physics.published_or_final_versio

Building an Improved Internet of Things Smart Sensor Network Based on a Three-Phase Methodology

© 2013 IEEE. In recent years, the Internet of Things (IoT) has allowed the easy, intelligent, and efficient connection of many devices used in daily life by means of numerous smart sensors which communicate with each other using wireless signals. The rapid development of the IoT has been a result of recent advances in sensing technology. This paper proposes a three-phase methodology to improve the quality of experience for IoT system technologies. The proposed method employs the concepts of simple routing and two well-known multi-criteria decision-making method (MCDM) techniques: The Analytic Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). First, all simple routings are obtained using the proposed depth-first search technology (DFS). AHP is applied to analyze the structure of the problem and to obtain weights for various selected criteria in the second phase. In the third phase, TOPSIS is utilized to rank the simple routings, which are simple paths. A case study example is provided to demonstrate the proposed three-phase methodology. The results from the numerical experiments show that the proposed methodology can successfully achieve the aim of this paper