Deposition of F-doped ZnO transparent thin films using ZnF2-doped ZnO target under different sputtering substrate temperatures

Highly transparent and conducting fluorine-doped ZnO (FZO) thin films were deposited onto glass substrates by radio-frequency (RF) magnetron sputtering, using 1.5 wt% zinc fluoride (ZnF2)-doped ZnO as sputtering target. Structural, electrical, and optical properties of the FZO thin films were investigated as a function of substrate temperature ranging from room temperature (RT) to 300°C. The cross-sectional scanning electron microscopy (SEM) observation and X-ray diffraction analyses showed that the FZO thin films were of polycrystalline nature with a preferential growth along (002) plane perpendicular to the surface of the glass substrate. Secondary ion mass spectrometry (SIMS) analyses of the FZO thin films showed that there was incorporation of F atoms in the FZO thin films, even if the substrate temperature was 300°C. Finally, the effect of substrate temperature on the transmittance ratio, optical energy gap, Hall mobility, carrier concentration, and resistivity of the FZO thin films was also investigated

Effects of Hydrogen Plasma on the Electrical Properties of F-Doped ZnO Thin Films and p-i-n -Si:H Thin Film Solar Cells

1.5 wt% zinc fluoride (ZnF2) was mixed with zinc oxide powder to form the F-doped ZnO (FZO) composition. At first, the FZO thin films were deposited at room temperature and 5×10-3 Torr in pure Ar under different deposition power. Hall measurements of the as-deposited FZO thin films were investigated, and then the electrical properties were used to find the deposition power causing the FZO thin films with minimum resistance. The FZO thin films with minimum resistance were further treated by H2 plasma and then found their variations in the electrical properties by Hall measurements. Hydrochloric (HCl) acid solutions with different concentrations (0.1%, 0.2%, and 0.5%) were used to etch the surfaces of the FZO thin films. Finally, the as-deposited, HCl-etched as-deposited, and HCl-etched H2-plasma-treated FZO thin films were used as transparent electrodes to fabricate the p-i-n α-Si:H thin film solar cells and their characteristics were compared in this study. We would show that using H2-plasma-treated and HCl-etched FZO thin films as transparent electrodes would improve the efficiency of the fabricated thin film solar cells

The Continuous Combinatorial Auction Architecture

The paper reports the architecture of a continuous combinatorial auction. Preferences are based on sets of items and feasibility requires the nonintersection of sets. Countdown clocks replace eligibility and activity requirements typical of rounds-based auctions. Bids remain in the system to be combined with new bids to form winning collections. Increment requirements dictate improvements over appropriate collections of existing bids. The auction evolved from experimental methods and operates at high levels of efficiency. Field applications are reported and result in natural equilibration in a few hours as opposed to days or weeks required by round-based architectures

Multiple Items, Ascending Price Auctions: An Experimental Examination of Alternative Auction Sequences

The paper investigates the revenue and efficiency of different ascending price auction architectures for the sale of three items and five bidders. Four architectures are studied: two different sequences of single item auctions, simultaneous auctions with a common countdown clock, and simultaneous auctions with item specific countdown clocks. A countdown clock measures the time until the auction closes but resets with each new bid. The environment contains independent private values, no uncertainty about own preferences, no information about other’s preferences, and a one unit budget constraint. The Nash equilibrium best response with straight forward bidding fits both dynamic and outcome data well. When non-unique Nash equilibria exist as in the case of simultaneous markets with a common clock, the social value maximizing Nash equilibrium emerges as the equilibrium selection. Both total revenue and efficiencies depend on the architecture as predicted by the Nash model, with the exception of the independent clocks architecture, which performs poorly on all dimensions

Discovery of selective inhibitors of Glutaminase-2, which inhibit mTORC1, activate autophagy and inhibit proliferation in cancer cells

Glutaminase, which converts glutamine to glutamate, is involved in Warburg effect in cancer cells. Two human glutaminase genes have been identified, GLS (GLS1) and GLS2. Two alternative transcripts arise from each glutaminase gene: first, the kidney isoform (KGA) and glutaminase C (GAC) for GLS; and, second, the liver isoform (LGA) and glutaminase B (GAB) for GLS2. While GLS1 is considered as a cancer therapeutic target, the potential role of GLS2 in cancer remains unclear. Here, we discovered a series of alkyl benzoquinones that preferentially inhibit glutaminase B isoform (GAB, GLS2) rather than the kidney isoform of glutaminase (KGA, GLS1). We identified amino acid residues in an allosteric binding pocket responsible for the selectivity. Treatment with the alkyl benzoquinones decreased intracellular glutaminase activity and glutamate levels. GLS2 inhibition by either alkyl benzoquinones or GLS2 siRNA reduced carcinoma cell proliferation and anchorage-independent colony formation, and induced autophagy via AMPK mediated mTORC1 inhibition. Our findings demonstrate amino acid sequences for selective inhibition of glutaminase isozymes and validate GLS2 as a potential anti-cancer target

Targeting a ribonucleoprotein complex containing the caprin-1 protein and the c-Myc mRNA suppresses tumor growth in mice: an identification of a novel oncotarget

Tylophorine compounds have been the focus of drug development for decades. Tylophorine derivatives exhibit anti-cancer activities but their cellular targets remain unknown. We used a biotinylated tylophorine derivative to probe for the interacting cellular target(s) of tylophorine. Tylophorine directly binds to caprin-1 and consequently enhances the recruitment of G3BP1, c-Myc mRNA, and cyclin D2 mRNA to form a ribonucleoprotein complex. Subsequently, this tylophorine targeted ribonucleoprotein complex is sequestered to the polysomal fractions and the protein expressions of the associated mRNA-transcripts are repressed. Caprin-1 depleted carcinoma cells become more resistant to tylophorine, associated with decreased formation of the ribonucleoprotein complex targeted by tylophorine. Consequently, tylophorine downregulates c-Myc and cyclins D1/D2, causing hypophosphorylation of Rb and suppression of both processing-body formation and the Warburg effect. Gene expression profiling and gain-of-c-Myc-function experiments also revealed that the downregulated c-Myc contributes to the anti-oncogenic effects of tylophorine compounds. Furthermore, the potent tylophorine derivative dibenzoquinoline-33b elicited a similar effect, as c-Myc protein levels were also decreased in xenograft tumors treated with dibenzoquinoline-33b. Thus, tylophorine compounds exert anti-cancer activity predominantly by targeting and sequestering the caprin-1 protein and c-Myc mRNA associated ribonucleoprotein complex

Interval between Intra-Arterial Infusion Chemotherapy and Surgery for Locally Advanced Oral Squamous Cell Carcinoma: Impacts on Effectiveness of Chemotherapy and on Overall Survival

Background. The interval between intra-arterial infusion chemotherapy (IAIC) and surgery was investigated in terms of its effects on survival in patients with locally advanced oral squamous cell carcinoma (OSCC). Methods. This retrospective study analyzed 126 patients who had completed treatment modalities for stage IV OSCC. All patients were followed up for 3 years. Kaplan-Meier and Cox regression methods were used to determine how survival was affected by general factors, primary tumor volume, TNM stage, and duration of neoadjuvant chemotherapy. Results. In 126 patients treated for locally advanced OSCC by preoperative induction IAIC using methotrexate, multivariate analysis of relevant prognostic factors showed that an IAIC duration longer than 90 days was significantly associated with poor prognosis (hazard ratio, 1.77; P=0.0259). Conclusions. Duration of IAIC is a critical factor in the effectiveness of multimodal treatment for locally advanced OSCC. Limiting the induction course to 90 days improves overall survival