Dissipation function of the first-order phase transformation in VO2 ceramics by internal-friction measurements

In order to apply the concept of the dissipation function during the first-order phase transition (FOPT) in solids, we measured the internal friction Q-1 and shear modulus μ for a range of frequencies of polycrystalline ceramics VO2 as the sample passed through a FOPT across the temperature range of 300–420 K. The experiment was repeated for different temperature variation rate Ṫ. We have found that for each frequency, a maximum of Q-1 and a minimum of μ occurred at the same temperature Tp when Ṫ was kept constant. The numerical values of the dissipation function ΔGR plus other FOPT parameters have been deduced using Q-1 data. The general trend of ΔGR-T and other results are found to be consistent with known physical aspects.published_or_final_versio

Reconstruction of 3D deformation from 2D MR velocity mapping with incompressibility constraints

This paper presents a new method for calculating 3D myocardial deformation from multislice 2D magnetic resonance velocity mapping. The method first involves the rectification of in-plane velocity distribution with a variational vector restoration method. This restored 2D velocity is then used to estimate the through-plane velocity component by applying a local incompressibility constraint. A global optimization procedure was then used to derive the velocity distribution that conforms to the incompressibility constraint. The proposed method was validated by using a simulation phantom with different levels of noise. The derived velocity field permits a full 3D deformation analysis of the myocardium

Narrowband Single-Pole Double-Throw Filtering Switch Based on Dielectric Resonator

© 2001-2012 IEEE. In this letter, a narrowband single-pole double-throw (SPDT) filtering switch based on dielectric resonators (DRs) is presented. It consists of two DRs shared by two channels for size reduction. Printed circuit boards are embedded in the metal cavity to integrate the PIN diodes. The switching between two channels is enabled by controlling the PIN diodes connected to the two output feeding lines. The electromagnetic field distributions of the DR at the TE -{11\delta } mode are studied to control the coupling between the DR and two output feeding lines. When one channel is on, the PIN diode for this channel is turned off, which does not introduce loss and affect the linearity. For the off-state channel, isolation is obtained by controlling the coupling between the DR and output feeding line, which is considerably enhanced. For demonstration, the DR filtering SPDT switch is implemented. The measured results exhibit that the proposed filtering SPDT switch has narrow bandwidth, low loss, high isolation, and high linearity

Recent changes of water discharge and sediment load in the Yellow River basin, China

The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613

Enhanced performance in polymer photovoltaic cells with chloroform treated indium tin oxide anode modification

Enhanced performance of a poly(3-hexylthiophene):(6,6)-phenyl C61 butyric acid methyl ester bulk heterojunction polymer photovoltaic cell is reported by modifying the indium tin oxide (ITO) anode with chloroform solution. Instead of the traditional UV-ozone treatment, the optimized chloroform modification on ITO anode can result in an enhancement in the power conversion efficiency of an identical device, originating from an increase in the photocurrent with negligible change in the open-circuit voltage. The performance enhancement is attributed to the work function modification of the ITO substrate through the surface incorporation of the chlorine, and thus improved charge collection efficiency. © 2011 American Institute of Physics

Surface plasmon-enhanced electroluminescence in organic light-emitting diodes incorporating Au nanoparticles

Surface plasmon-enhanced electroluminescence (EL) in an organic light-emitting diode is demonstrated by incorporating the synthesized Au nanoparticles (NPs) in the hole injection layer of poly(3,4-ethylene dioxythiophene):polystyrene sulfonic acid. An increase of ∼25% in the EL intensity and efficiency are achieved for devices with Au NPs, whereas the spectral and electrical properties remain almost identical to the control device. Time-resolved photoluminescence spectroscopy reveals that the EL enhancement is ascribed to the increase in spontaneous emission rate due to the plasmonic near-field effect induced by Au NPs. © 2012 American Institute of Physics

Unique pattern of infections in chronic granulomatous disease – The Asian experience

Conference Theme: Inflammatory Basis of Perinatal and Childhood DiseasesSymposium 40: InfectionBackground: Chronic granulomatous disease (CGD) is a phagocytic disorder caused by defective NADPH oxidase activity. Affected individuals are susceptible to bacterial infections, mycosis and hyperinflammatory complications. Variations in the epidemiology of infectious diseases across geographical regions can lead to distinct clinical phenotypes. Objective: To identify the unique clinical characteristics of a large cohort of CGD patients in China and Southeast Asia referred for genetic studies from 2003 to 2012. Methods: 53 patients with genetically-confirmed CGD were included and their clinical features were analyzed. CYBB and CYBA mutations were studied by Sanger sequencing, and NCF1 ‘GT’ deletion hotspot mutation was studied on genomic DNA by GeneScan. Results: 44 patients with X-CGD had CYBB mutations (missense[n=16]; nonsense[n=8]; deletion[n=9]; insertion[n=2]; intron mutation[n=9]). Nine patient had AR-CGD (CYBA[n=5]; NCF1 75_76delGT[n=4]). The median age at presentation and diagnosis was higher in AR-CGD (7m and 66m) compared with X-CGD (3m and 22m). The commonest presentations were pneumonia (58%), skin and perianal abscess (49%), lymphadenitis (42%) and recurrent diarrhea (30%). Aspergillosis and salmonellosis occurred at a frequency similar to published studies (13% and 19% respectively), but the commonest infection was BCG (43%) and 11% had disseminated BCG. 21% of patients had tuberculosis. Fulminant melioidosis and Chromobacterium violaceum infections occurred in 3 patients and two of their male siblings. Hyperinflammatory conditions included polyarthritis (n=3) and pulmonary granuloma (n=2). Death was recorded in 8 patients (15%). Conclusion: Melioidosis and C. violaceum indigenous to Southeast Asia can cause life-threatening infections in CGD patients. The high incidence of mycobacterial infections is associated with universal BCG vaccination and endemicity of tuberculosis. Such observations emphasize the role of respiratory burst as an immune defense mechanism against these pathogens. These infections are seldom reported in Caucasian cohorts, illustrating the importance of regional collaborative studies to facilitate pattern recognition and early diagnosis of primary immunodeficiencies.published_or_final_versio

Alisertib, an Aurora kinase A inhibitor, induces apoptosis and autophagy but inhibits epithelial to mesenchymal transition in human epithelial ovarian cancer cells.

Ovarian cancer is a leading killer of women, and no cure for advanced ovarian cancer is available. Alisertib (ALS), a selective Aurora kinase A (AURKA) inhibitor, has shown potent anticancer effects, and is under clinical investigation for the treatment of advanced solid tumor and hematologic malignancies. However, the role of ALS in the treatment of ovarian cancer remains unclear. This study investigated the effects of ALS on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition (EMT), and the underlying mechanisms in human epithelial ovarian cancer SKOV3 and OVCAR4 cells. Our docking study showed that ALS, MLN8054, and VX-680 preferentially bound to AURKA over AURKB via hydrogen bond formation, charge interaction, and π-π stacking. ALS had potent growth-inhibitory, proapoptotic, proautophagic, and EMT-inhibitory effects on SKOV3 and OVCAR4 cells. ALS arrested SKOV3 and OVCAR4 cells in G2/M phase and induced mitochondria-mediated apoptosis and autophagy in both SKOV3 and OVCAR4 cell lines in a concentration-dependent manner. ALS suppressed phosphatidylinositol 3-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways but activated 5\u27-AMP-dependent kinase, as indicated by their altered phosphorylation, contributing to the proautophagic activity of ALS. Modulation of autophagy altered basal and ALS-induced apoptosis in SKOV3 and OVCAR4 cells. Further, ALS suppressed the EMT-like phenotype in both cell lines by restoring the balance between E-cadherin and N-cadherin. ALS downregulated sirtuin 1 and pre-B cell colony enhancing factor (PBEF/visfatin) expression levels and inhibited phosphorylation of AURKA in both cell lines. These findings indicate that ALS blocks the cell cycle by G2/M phase arrest and promotes cellular apoptosis and autophagy, but inhibits EMT via phosphatidylinositol 3-kinase/Akt/mTOR-mediated and sirtuin 1-mediated pathways in human epithelial ovarian cancer cells. Further studies are warranted to validate the efficacy and safety of ALS in the treatment of ovarian cancer

Wideband Diplexer with Narrow Channel Spacing Using Hybrid Bandpass-Bandstop Structures

© 2013 IEEE. In this paper, a wideband diplexer with narrow channel spacing is designed by using hybrid bandpass-bandstop structures. Two wideband bandpass structures are designed with the transmission zeros at the upper or lower passband edges to achieve high skirt selectivity. Two bandstop structures based on half-wavelength coupled lines are integrated to the two bandpass structures to introduce additional transmission zeros and thus the skirt selectivity is further improved. Accordingly, two channel filters with high skirt selectivity and high stopband rejection are designed to realize a wideband microstrip diplexer with very narrow channel spacing. For verification, a wideband diplexer operating at 1.71-2.17 GHz and 2.30-2.70 GHz is implemented, which covers multiple frequency bands for different mobile systems. The measured results show excellent performance of passband flatness, high in-band isolation of better than 35 dB and low minimum insertion losses of 0.46 and 0.50 dB for the two channels

A comparative study of skin cell activities in collagen and fibrin constructs.

Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength