ALBERT

Description: Abstract The dielectric relaxation and conduction properties of hexaferrite BaFe10.2Sc1.8O19 (BFSO) ceramics have been investigated by impedance spectroscopy (1 Hz‐2 GHz) at various temperatures (253‐473 K). The frequency dependence of impedance and modulus spectra of BFSO shows that its dielectric responses are thermally activated. The scaling behaviors of impedance spectra indicate that the distribution of dielectric relaxation times in BFSO is temperature independent. The frequency‐dependent conductivity spectra follow the universal‐power‐law at high temperatures but deviate slightly at low temperatures. An enormous increase in relaxation/conduction activation energies of BFSO above 413 K is also observed in both impedance and conductivity spectra. This indicates that at high temperatures, relaxation/conduction processes may be contributed mainly by the movable oxygen vacancies, whereas at low‐temperature electron hopping dominates. The conductivity fitting results further suggest that electron/oxygen vacancy‐related small polaron hopping should be the most probable conduction mechanism for BFSO.

Description: 6H-SiC powder mixed with Si 3 N 4 , Al 2 O 3 , Y 2 O 3 , and AlN was sintered in a spark plasma sintering (SPS) equipment. The 6H→3CSiC transformation was concerned. Research results indicated the polytype transformation completed in less than 30 s by imposing a 14 458 W (6.2 V, 2332 A) transitory DC current at 1700°C upon cooling down from 2000°C. The fast transformation kinetic and the significant 3C-SiC grain growth accompanying the phase transformation were suspected to be correlated with the pulsed SPS direct current.

Description: Evapotranspiration ( ET ), which links water, energy and the carbon cycle in terrestrial ecosystems, is an important eco-hydrological process, especially in arid and semi-arid regions. To determine the crop coefficient ( K c ) over a two-year period for a temperate desert steppe in Inner Mongolia, China, ET was measured using the eddy covariance method and the reference evapotranspiration ( ET 0 ) was estimated from site meteorological data. The results showed that the seasonal variation of ET differed on an annual timescale between the two consecutive years, exhibiting a multi-peak curve in 2008 and a single peak in 2009. The mean daily K c values were 0.15 and 0.17 in two years, varying from 0.009 to 0.75 in 2008 and from 0.005 to 0.58 in 2009. The 5-day moving average for K c values was mainly affected by SWC 10cm and R n , and the regression coefficients ( R 2 ) were 58.9% and 69.5%, respectively. These results will aid in making accurate and quantitative assessments of the vulnerability of the sparse vegetation to climate change. Copyright © 2011 John Wiley & Sons, Ltd.

Description: Abstract Signals prior to tropical cyclone (TC) intensification are important for improving TC intensity forecasts. The existence of such signals has been noted in previous studies of satellite‐borne observations and lightning. Vertical motions can enhance TCs via the transportation of heat to the warm core; thus, we hypothesized they might signal TC intensification. This study separately examined the processes of updrafts and downdrafts, which are both concentrated within the eyewall surrounding the warm core. The analysis focused on the intensification of Typhoon Hagupit (2008). Numerical experiments were conducted using the Weather Research and Forecasting model to elucidate the changing structure of the vertical motions and their effects on the timing of TC intensification. A control (CTL) simulation and an idealized No‐Land experiment both reproduced the storm structure well, whereas a Half‐Bogus (Half‐Moisture) experiment generated less‐organized TC core structures (weakened moisture convection). Upward motions were found to signal TC intensification with lead times of 1.67–4.50 hr in all experiments. Downward motions apparently signaled TC intensification with lead times of 0.67–4.50 hr in the Half‐Bogus and Half‐Moisture experiments. However, the lead‐lag relationship between downward motion and TC intensification was unclear in the CTL and No‐Land experiments because of the large amount of water vapor in the enhanced eyewall. Thermodynamic analysis showed the latent heat consumed in the downdrafts in the CTL and No‐Land experiments was much greater than in the two other experiments, which resulted in the smallest heating contribution in the downdrafts and a weak relationship with TC intensification.

Description: Long non-coding RNAs (lncRNAs) have played critical roles in a variety of cancers, including non-small cell lung cancer (NSCLC). In our study, we focused on the biological function and clinical significance of lncRNA LINC00968 in NSCLC. It was indicated that LINC00968 was significantly increased in LUAD tissues, LUSC tissues and NSCLC cells compared to their corresponding controls. Inhibition of LINC00968 was able to repress NSCLC growth, migration and invasion in vitro while upregulation of LINC00968 reversed this process. Additionally, downregulation of LINC00968 induced apoptosis capacity of A549 cell. Apoptosis-related proteins BCL-2 were decreased and BAX was increased by knockdown of LINC00968 respectively. Meanwhile we observed that Wnt signaling pathway was involved in the LINC00968-induced NSCLC progression. Finally, in vivo tumor xenografts were established using A549 cells to detect the function of LINC00968 in NSCLC tumorigenesis. Silencing LINC00968 greatly inhibited NSCLC tumor progression, which was consistent with the in vitro tests. In conclusion, we have uncovered that LINC00968 could be regarded as a novel prognostic biomarker and therapeutic target in NSCLC diagnosis and treatment. This article is protected by copyright. All rights reserved

Description: The Rab-family GTPases mainly regulate intracellular vesicle transport, and play important roles in the innate immune response in invertebrates. However, the function and signal transduction of Rab proteins in immune reactions remain unclear in silkworms. In this study, we analyzed a Rab-related protein of silkworm Bombyx mori (BmRABRP) by raising antibodies against its bacterially expressed recombinant form. Tissue distribution analysis showed that BmRABRP mRNA and protein were high expressed in the Malpighian tubule and fat body, respectively. However, among the different stages, only the fourth instar larvae and pupae showed significant BmRABRP levels. After challenge with four pathogenic microorganisms ( Escherichia coli , BmNPV , Beauveria bassiana , Micrococcus luteus ), the expression of BmRABRP mRNA in the fat body was significantly upregulated. In contrast, the BmRABRP protein was significantly upregulated after infection with BmNPV , while it was downregulated by E. coli , B. bassiana , and M. luteus . A specific dsRNA was used to explore the immune function and relationship between BmRABRP and the JAK-STAT signaling pathway. After BmRABRP gene interference, significant reduction in the number of nodules and increased mortality suggested that BmRABRP plays an important role in silkworm's response to bacterial challenge. In addition, four key genes ( BmHOP , BmSTAT , BmSOCS2 , and BmSOCS6 ) of the JAK-STAT signaling pathway showed significantly altered expressions after BmRABRP silencing. BmHOP and BmSOCS6 expressions were significantly decreased, while BmSTAT and BmSOCS2 were significantly upregulated. Our results suggested that BmRABRP is involved in the innate immune response against pathogenic microorganisms through the JAK-STAT signaling pathway in silkworm.

Description: L6 rat myoblasts undergo differentiation and myotube formation when cultured in medium containing a low-concentration of serum, but the underlying mechanism is not well understood. The role of atrogin-1, an E3 ligase with well-characterized roles in muscle atrophy, has not been defined in muscle differentiation. Myocardin is a coactivator of serum response factor (SRF), which together promotes smooth muscle differentiation. Myocardin is transiently expressed in skeletal muscle progenitor cells with inhibitory effects on the expression of myogenin and muscle differentiation. It remains unknown whether myocardin, which undergoes ubiquitination degradation, plays a role in L6 cell differentiation. The current study aimed to investigate the potential roles of myocardin and atrogin-1 in differentiation of L6 cells. As reported by many others, shifting to medium containing 2% serum induced myotube formation of L6 cells. Differentiation was accompanied by up-regulation of atrogin-1 and down-regulation of myocardin, suggesting that both may be involved in muscle differentiation. As expected, overexpression of atrogin-1 stimulated the expression of troponin T and myogenin and differentiation of the L6 myoblasts. Co-expression of myocardin with atrogin-1 inhibited atrogin-1-induced myogenin expression. Overexpression of atrogin-1 decreased myocardin protein level, albeit without affecting its mRNA level. Small-interfering RNA-mediated knockdown of atrogin-1 increased myocardin protein. Consistently, ectopic expression of myocardin inhibited myogenic differentiation. Unexpectedly, myocardin decreased the expression of atrogin-1 without involving Foxo1. Taken together, our results have demonstrated that atrogin-1 plays a positive role in skeletal muscle differentiation through down-regulation of myocardin. J. Cell. Physiol. © 2013 Wiley Periodicals, Inc.

Description: Abstract The flexoelectric effect of the ferroelectric materials has been intensively studied in recent years. One unresolved issue in this field is that the measured flexoelectric coefficients in ferroelectrics are often several orders of magnitude greater than the values predicted by the theoretical studies. To understand the mechanism for this discrepancy, the flexoelectric response of the Na0.5Bi0.5TiO3–BaTiO3 (NBBT) ceramics of different compositions was systematically studied. We show that the measured flexoelectric response of the NBBT ceramics is mainly from the piezoelectric response of the spontaneously polarized surface in the ceramics. The surface effect can be reduced or removed by abrading the surface off or modifying the compositions of the surface. The thickness of the surface layer was found to be 10‐15 µm. We also show that the composition dependence of the flexoelectric response is mainly affected by the piezoelectric response of the surface layer, whereas the temperature dependence of the flexoelectric response of a composition is primarily influenced by the dielectric constant of the bulk. The mechanisms for the observations are discussed based on the origin of the surface layer. This work is important for the understanding of the mechanisms of the flexoelectric (or flexoelectric‐like) response in ferroelectrics.

Description: A series of five new Zn(II) and Cd(II) mixed-ligand coordination polymers, namely, {[Zn(L1)(4,4'-bpy)]*(ClO4)*2H2O} (1), {[Zn(L2)(4,4'-bpy)0.5]*(ClO4)} (2), {[Zn(L3)(4,4'-bpy)]*(NO3)*2H2O} (3), {[Cd(L4)(4,4'-bpy)0.5(NO3)]*5H2O} (4) and {[Zn(L4)(4,4'-bpy)]*Cl*H2O} (5), have been obtained by the reactions of the 4,4'-bipyridine with four dicarboxylate zwitterionic pyridine ligands. Single-crystal X-ray structural analyses reveal that the five complexes demonstrate different molecular frameworks coming from various coordination modes and flexibilities of different dicarboxylate zwitterionic pyridine ligands and metal centers. Mononuclear 2-fold dinuclear 2D 2-fold interpenetrating net for 2, four-coordinate mononuclear 2-fold interpenetrating 2D layer for 3, mononuclear 2D layer arranged in parallel and with large grids for 4 and 2-fold trans interpenetrating 2D network for compound 5. The structural diversities in 1-5 indicate that the nature of the ligands and the presence of different metal atoms have a great influence on metal center coordination modes and the structural topologies of the metal-organic molecular architectures. In addition, π***π stacking interactions also play important roles in the final crystal packing and supramolecular frameworks. The powder X-ray diffraction, elemental analysis and the photoluminescence properties of 1-5 were studied, which show that architectures play an important role in emission bands and intensities.