Initiation and stagnation of room temperature grain coarsening in cyclically strained gold films

Despite the large number of experiments demonstrating that grains in a metallic material can grow at room temperature due to applied mechanical load, the mechanisms and the driving forces responsible for mechanically induced grain coarsening are still not understood. Here we present a systematic study of room temperature grain coarsening induced by cyclic strain in thin polymer-supported gold films. By means of detailed electron backscatter diffraction analysis we were able to capture both the growth of individual grains and the evolution of the whole microstructure on the basis of statistical data over thousands of grains. The experimental data are reported for three film thicknesses with slightly different microstructures and three different amplitudes of cyclic mechanical loading. Although different kinds of grain size evolution with increasing cycle number are observed depending on film thickness and strain amplitude, a single model based on a thermodynamic driving force is shown to be capable to explain initiation and stagnation of grain coarsening in all cases. The main implication of the model is that the grains having lower individual yield stress are coarsening preferentially. Besides, it is demonstrated that the existence of local shear stresses imposed on a grain boundary is not a necessary requirement for room-temperature grain coarsening

Sovereignty, Protection and the Limits to Regional Refugee Status Determination Arrangements

This case note explores the recent Australian High Court decision of Plaintiff M70/2011 v Minister for Immigration and Citizenship, which declared a proposed regional refugee status determination arrangement between Australia and Malaysia to be unlawful under Australian law. While the decision was determined by the specific statutory construction of Australian's migration legislation, it nonetheless draws attention to the legal character of what constitutes 'protection' under international refugee law and suggests the necessary legal and factual conditions that must exist in a 'third country' in order for any transfer of refugee processing and recognition procedures to be seen to satisfy Convention obligations. It thus represents a significant judicial challenge to the contemporary trend pursued by wealthy industrialised nations in the Global North towards erecting barriers for accessing domestic asylum regimes and adopting policies that in effect outsource and extraterritorialise asylum processing under the guise of 'burden sharing' or regional 'harmonisation'. This case note reads the decision as a particular re-articulation of sovereign authority, borders, belonging and place-making

Arzanol, a prenylated heterodimeric phloroglucinyl pyrone, inhibits eicosanoid biosynthesis and exhibits anti-inflammatory efficacy in vivo.

Based on its capacity to inhibit in vitro HIV-1 replication in T cells and the release of pro-inflammatory cytokines in monocytes, the prenylated heterodimeric phloroglucinyl α-pyrone arzanol was identified as the major anti-inflammatory and anti-viral constituent from Helichrysum italicum. We have now investigated the activity of arzanol on the biosynthesis of pro-inflammatory eicosanoids, evaluating its anti-inflammatory efficacy in vitro and in vivo. Arzanol inhibited 5-lipoxygenase (EC 7.13.11.34) activity and related leukotriene formation in neutrophils, as well as the activity of cyclooxygenase (COX)-1 (EC 1.14.99.1) and the formation of COX-2-derived prostaglandin (PG)E(2)in vitro (IC(50)=2.3-9μM). Detailed studies revealed that arzanol primarily inhibits microsomal PGE(2) synthase (mPGES)-1 (EC 5.3.99.3, IC(50)=0.4μM) rather than COX-2. In fact, arzanol could block COX-2/mPGES-1-mediated PGE(2) biosynthesis in lipopolysaccharide-stimulated human monocytes and human whole blood, but not the concomitant COX-2-derived biosynthesis of thromboxane B(2) or of 6-keto PGF(1α), and the expression of COX-2 or mPGES-1 protein was not affected. Arzanol potently suppressed the inflammatory response of the carrageenan-induced pleurisy in rats (3.6mg/kg, i.p.), with significantly reduced levels of PGE(2) in the pleural exudates. Taken together, our data show that arzanol potently inhibits the biosynthesis of pro-inflammatory lipid mediators like PGE(2)in vitro and in vivo, providing a mechanistic rationale for the anti-inflammatory activity of H. italicum, and a rationale for further pre-clinical evaluation of this novel anti-inflammatory lead

Separation of specific single-enantiomer single-wall carbon nanotubes in the large-diameter regime

The enantiomer-level isolation of single-walled carbon nanotubes (SWCNTs) in high concentration and with high purity for nanotubes greater than 1.1 nm in diameter is demonstrated using a two-stage aqueous two-phase extraction (ATPE) technique. In total, five different nanotube species of ∼1.41 nm diameter are isolated, including both metallics and semiconductors. We characterize these populations by absorbance spectroscopy, circular dichroism spectroscopy, resonance Raman spectroscopy, and photoluminescence mapping, revealing and substantiating mod-dependent optical dependencies. Using knowledge of the competitive adsorption of surfactants to the SWCNTs that controls partitioning within the ATPE separation, we describe an advanced acid addition methodology that enables the fine control of the separation of these select nanotubes. Furthermore, we show that endohedral filling is a previously unrecognized but important factor to ensure a homogeneous starting material and further enhance the separation yield, with the best results for alkane-filled SWCNTs, followed by empty SWCNTs, with the intrinsic inhomogeneity of water-filled SWCNTs causing them to be worse for separations. Lastly, we demonstrate the potential use of these nanotubes in field-effect transistors

Kinetics and crystallization path of a Fe-based metallic glass alloy

The thermal stability and the quantification of the different transformation processes involved in the overall crystallization of the Fe50Cr15Mo14C15B6 amorphous alloy were investigated by several characterization techniques. Formation of various metastable and stable phases during the devitrification process in the sequence a-Fe, ¿-Cr6Fe18Mo5, M23(C,B)6, M7C3, ¿-Fe3Mo3C and FeMo2B2 (with M = Fe, Cr, Mo), was observed by in-situ synchrotron high energy X-ray diffraction and in-situ transmission electron microscopy. By combining these techniques with differential scanning calorimetry data, the crystallization states and their temperature range of stability under continuous heating were related with the evolution of the crystallized fraction and the phase sequence as a function of temperature, revealing structural and chemical details of the different transformation mechanisms.Postprint (published version

Constitutively-active androgen receptor variants function independently of the HSP90 chaperone but do not confer resistance to HSP90 inhibitors

The development of lethal, castration resistant prostate cancer is associated with adaptive changes to the androgen receptor (AR), including the emergence of mutant receptors and truncated, constitutively active AR variants. AR relies on the molecular chaperone HSP90 for its function in both normal and malignant prostate cells, but the requirement for HSP90 in environments with aberrant AR expression is largely unknown. Here, we investigated the efficacy of three HSP90 inhibitors, 17-AAG, HSP990 and AUY922, against clinically-relevant AR missense mutants and truncated variants. HSP90 inhibition effectively suppressed the signaling of wild-type AR and all AR missense mutants tested. By contrast, two truncated AR variants, AR-V7 and ARv567es, exhibited marked resistance to HSP90 inhibitors. Supporting this observation, nuclear localization of the truncated AR variants was not affected by HSP90 inhibition and AR variant:HSP90 complexes could not be detected in prostate cancer cells. Interestingly, HSP90 inhibition resulted in accumulation of AR-V7 and ARv567es in both cell lines and human tumor explants. Despite the apparent independence of AR variants from HSP90 and their treatment-associated induction, the growth of cell lines with endogenous or enforced expression of AR-V7 or ARv567es remained highly sensitive to AUY922. This study demonstrates that functional AR variant signaling does not confer resistance to HSP90 inhibition, yields insight into the interaction between AR and HSP90 and provides further impetus for the clinical application of HSP90 inhibitors in advanced prostate cancer.Joanna L. Gillis, Luke A. Selth, Margaret M. Centenera, Scott L. Townley, Shihua Sun, Stephen R. Plymate, Wayne D. Tilley and Lisa M. Butle

Light emission, light detection and strain sensing with nanocrystalline graphene

Graphene is of increasing interest for optoelectronic applications exploiting light detection, light emission and light modulation. Intrinsically light matter interaction in graphene is of a broadband type. However by integrating graphene into optical micro cavities also narrow band light emitters and detectors have been demonstrated. The devices benefit from the transparency, conductivity and processability of the atomically thin material. To this end we explore in this work the feasibility of replacing graphene by nanocrystalline graphene, a material which can be grown on dielectric surfaces without catalyst by graphitization of polymeric films. We have studied the formation of nanocrystalline graphene on various substrates and under different graphitization conditions. The samples were characterized by resistance, optical transmission, Raman, X-ray photoelectron spectroscopy, atomic force microscopy and electron microscopy measurements. The conducting and transparent wafer-scale material with nanometer grain size was also patterned and integrated into devices for studying light-matter interaction. The measurements show that nanocrystalline graphene can be exploited as an incandescent emitter and bolometric detector similar to crystalline graphene. Moreover the material exhibits piezoresistive behavior which makes nanocrystalline graphene interesting for transparent strain sensors

Investigation wettability of carbon components with the polyurethane binder of resistive composites

The research paper deals with influence wettability of carbon components with the polyurethane binder of resistive composites. We have revealed that the polyurethane lacquer wets up to 25 wt. % of C-1 and GE-3 particles, which results in their uniform distribution over the entire volume of the binder and homogeneity of RCMs. Zero wetting of the same weight percentage is observed in the case of K-163 carbon black, which gives rise to caking and distortion of homogeneity of the composite coating after its formation and its further cracking after heat treatment. The wetting capacity of K-163 carbon black in the polyurethane lacquer is improved using a DISPERBYK-2155 dispersing agent in the amount of 10 wt. % with respect to the binder. The resulting experimental data indicate that C-1 particles exhibit the best wettability, hence their adhesion strength with the binder would be higher than that of GE-3 graphite element and K-163 carbon black

The novel Sinupret® dry extract exhibits anti-inflammatory effectiveness in vivo

Sinupret® is frequently used as a herbal medicinal product to treat sinusitis, and it was assumed that anti-inflammatory effects might contribute to its overall beneficial properties. Here, we investigated the effects of a Sinupret® drug mixture (SIN) as well as of the novel Sinupret® dry extract (SIN DE) with the latter containing higher concentrations of active ingredients, in an in vivo model of acute inflammation, the carrageenan-induced pleurisy in rats. Both SIN and SIN DE were administered to rats orally at doses of 100mg/kg (low dose) and 500mg/kg (high dose) 1h prior to intrapleural injection of carrageenan. Although both SIN and SIN DE significantly reduced the exudate volume and leukocyte numbers in the pleural exudate at the high and the low dose 4h after carrageenan injection, the novel SIN DE was more efficient than SIN at the low dose, implying higher efficiency. In parallel, the novel dry extract SIN DE, but not SIN, at 500mg/kg significantly lowered the levels of prostaglandin (PG)E(2) in the exudates and reduced the amounts of cyclooxygenase (COX)-2 protein in the lungs. Together, SIN and SIN DE exert significant oral anti-inflammatory effects, which rationalize their therapeutic use in the management of sinusitis and other viral/microbial nasal infections that are associated with inflammation. Moreover, our results suggest that based on the higher efficiency and the accompanied reduction of COX-2 expression and PGE(2) formation, the novel dry extract SIN DE might be superior over the former SIN drug mixture