Continuous and reversible tuning of the disorder-driven superconductor-insulator transition in bilayer graphene

The influence of static disorder on a quantum phase transition (QPT) is a fundamental issue in condensed matter physics. As a prototypical example of a disorder-tuned QPT, the superconductor-insulator transition (SIT) has been investigated intensively over the past three decades, but as yet without a general consensus on its nature. A key element is good control of disorder. Here, we present an experimental study of the SIT based on precise in-situ tuning of disorder in dual-gated bilayer graphene proximity-coupled to two superconducting electrodes through electrical and reversible control of the band gap and the charge carrier density. In the presence of a static disorder potential, Andreev-paired carriers formed close to the Fermi level in bilayer graphene constitute a randomly distributed network of proximity-induced superconducting puddles. The landscape of the network was easily tuned by electrical gating to induce percolative clusters at the onset of superconductivity. This is evidenced by scaling behavior consistent with the classical percolation in transport measurements. At lower temperatures, the solely electrical tuning of the disorder-induced landscape enables us to observe, for the first time, a crossover from classical to quantum percolation in a single device, which elucidates how thermal dephasing engages in separating the two regimes.1132Ysciescopu

Dry semi-continuous anaerobic digestion of food waste in the mesophilic and thermophilic modes: New aspects of sustainable management and energy recovery in South Korea

© 2016 Elsevier Ltd In this study, parallel, bench-scale, mesophilic and thermophilic, dry, semi-continuous anaerobic digestion (DScAD) of Korea food waste (FW, containing 22% total solids (TS) and 20% volatile solids (VS)) was investigated thoroughly under varying operational conditions, including hydraulic retention times (HRTs) and organic loading rates (OLRs). The aim was to evaluate the start-up, stability, overall removal efficiency, and inhibitory effects of toxic compounds on process performance over a long-term operation lasting 100 days. The results from both digesters indicate that the simultaneous reduction of VS and the production of gas improved as the HRT decreased or the OLR increased. The highest average rates of VS reduction (79.67%) and biogas production (162.14 m3biogas/ton of FW, 61.89% CH4), at an OLR of 8.62 ± 0.34 kg VS/m3day (25 days of HRT), were achieved under thermophilic DScAD. In addition, the average rates of reduction of VS and the production of biogas in thermophilic DScAD were higher by 6.88% and 16.4%, respectively, than were those in mesophilic DScAD. The inhibitory effects of ammonia, H2S, and volatile fatty acids (VFAs) on methane production was not clear from either of the digesters, although, apparently, their concentrations did fluctuate. This fluctuation could be attributed to the self-adaptation of the microbial well. However, digestion that was more stable and faster was observed under thermophilic conditions compared with that under mesophilic conditions. Based on our results, the optimum operational parameters to improve FW treatment and achieve higher energy yields could be determined, expanding the application of DScAD in treating organic wastes

Identifying Pathway Proteins in Networks using Convergence

One of the key goals of systems biology concerns the analysis of experimental biological data available to the scientific public. New technologies are rapidly developed to observe and report whole-scale biological phenomena; however, few methods exist with the ability to produce specific, testable hypotheses from this noisy ‘big’ data. In this work, we propose an approach that combines the power of data-driven network theory along with knowledge-based ontology to tackle this problem. Network models are especially powerful due to their ability to display elements of interest and their relationships as internetwork structures. Additionally, ontological data actually supplements the confidence of relationships within the model without clouding critical structure identification. As such, we postulate that given a (gene/protein) marker set of interest, we can systematically identify the core of their interactions (if they are indeed working together toward a biological function), via elimination of original markers and addition of additional necessary markers. This concept, which we refer to as “convergence,” harnesses the idea of “guilt-by-association” and recursion to identify whether a core of relationships exists between markers. In this study, we test graph theoretic concepts such as shortest-path, k-Nearest- Neighbor and clustering) to identify cores iteratively in data- and knowledge-based networks in the canonical yeast Pheromone Mating Response pathway. Additionally, we provide results for convergence application in virus infection, hearing loss, and Parkinson’s disease. Our results indicate that if a marker set has common discrete function, this approach is able to identify that function, its interacting markers, and any new elements necessary to complete the structural core of that function. The result below find that the shortest path function is the best approach of those used, finding small target sets that contain a majority or all of the markers in the gold standard pathway. The power of this approach lies in its ability to be used in investigative studies to inform decisions concerning target selection

Subthreshold characteristics of pentacene field-effect transistors influenced by grain boundaries

Grain boundaries in polycrystalline pentacene films significantly affect the electrical characteristics of pentacene field-effect transistors (FETs). Upon reversal of the gate voltage sweep direction, pentacene FETs exhibited hysteretic behaviours in the subthreshold region, which was more pronounced for the FET having smaller pentacene grains. No shift in the flat-band voltage of the metal-insulator-semiconductor capacitor elucidates that the observed hysteresis was mainly caused by the influence of localized trap states existing at pentacene grain boundaries. From the results of continuous on/off switching operation of the pentacene FETs, hole depletion during the off period is found to be limited by pentacene grain boundaries. It is suggested that the polycrystalline nature of a pentacene film plays an important role on the dynamic characteristics of pentacene FETs

Adenoma of the nonpigmented ciliary epithelium presenting with recurrent iridocyclitis: unique expression of glial fibrillary acidic protein

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Lethality and centrality in protein networks

In this paper we present the first mathematical analysis of the protein interaction network found in the yeast, S. cerevisiae. We show that, (a) the identified protein network display a characteristic scale-free topology that demonstrate striking similarity to the inherent organization of metabolic networks in particular, and to that of robust and error-tolerant networks in general. (b) the likelihood that deletion of an individual gene product will prove lethal for the yeast cell clearly correlates with the number of interactions the protein has, meaning that highly-connected proteins are more likely to prove essential than proteins with low number of links to other proteins. These results suggest that a scale-free architecture is a generic property of cellular networks attributable to universal self-organizing principles of robust and error-tolerant networks and that will likely to represent a generic topology for protein-protein interactions.Comment: See also http:/www.nd.edu/~networks and http:/www.nd.edu/~networks/cel

Pharmacokinetic characteristics and anticancer effects of 5-Fluorouracil loaded nanoparticles

<p>Abstract</p> <p>Background</p> <p>It is expected that prolonged circulation of anticancer drugs will increase their anticancer activity while decreasing their toxic side effects. The purpose of this study was to prepare 5-fluorouracil (5-FU) loaded block copolymers, with poly(γ-benzyl-L-glutamate) (PBLG) as the hydrophobic block and poly(ethylene glycol) (PEG) as the hydrophilic block, and then examine the 5-FU release characteristics, pharmacokinetics, and anticancer effects of this novel compound.</p> <p>Methods</p> <p>5-FU loaded PEG-PBLG (5-FU/PEG-PBLG) nanoparticles were prepared by dialysis and then scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the shape and size of the nanoparticles, and ultraviolet spectrophotometry was used to evaluate the 5-FU in vitro release characteristics. The pharmacokinetic parameters of 5-FU/PEG-PBLG nanoparticles in rabbit plasma were determined by measuring the 5-FUby high-performance liquid chromatography (HPLC). To study in vivo effects, LoVo cells (human colon cancer cell line) or Tca8113 cells (human oral squamous cell carcinoma cell line) were implanted in BALB/c nude mice that were subsequently treated with 5-FU or 5-FU/PEG-PBLG nanospheres.</p> <p>Results</p> <p>5-FU/PEG-PBLG nanoparticles had a core-shell spherical structure with a diameter of 200 nm and a shell thickness of 30 nm. The drug loading capacity was 27.1% and the drug encapsulation was 61.5%. Compared with 5-FU, 5-FU/PEG-PBLG nanoparticles had a longer elimination half-life (t_1/2, 33.3 h vs. 5 min), lower peak concentration (C, 4563.5 μg/L vs. 17047.3 μg/L), and greater distribution volume (V_D, 0.114 L vs. 0.069 L). Compared with a blank control, LoVo cell xenografts and Tca8113 cell xenografts treated with 5-FU or 5-FU/PEG-PBLG nanoparticles grew slower and had prolonged tumor doubling times. 5-FU/PEG-PBLG nanoparticles showed greater inhibition of tumor growth than 5-FU (p < 0.01). In the PEG-PBLG nanoparticle control group, there was no tumor inhibition (p > 0.05).</p> <p>Conclusion</p> <p>In our model system, 5-FU/PEG-PBLG nanoparticles changed the pharmacokinetic behavior of 5-FU, thus increasing its anticancer activity. 5-Fluorouracil loaded nanoparticles have potential as a novel anticancer drug that may have useful clinical applications.</p

Development of an in vitro periodontal biofilm model for assessing antimicrobial and host modulatory effects of bioactive molecules

Background: Inflammation within the oral cavity occurs due to dysregulation between microbial biofilms and the host response. Understanding how different oral hygiene products influence inflammatory properties is important for the development of new products. Therefore, creation of a robust host-pathogen biofilm platform capable of evaluating novel oral healthcare compounds is an attractive option. We therefore devised a multi-species biofilm co-culture model to evaluate the naturally derived polyphenol resveratrol (RSV) and gold standard chlorhexidine (CHX) with respect to anti-biofilm and anti-inflammatory properties.&lt;p&gt;&lt;/p&gt; Methods: An in vitro multi-species biofilm containing &lt;i&gt;S. mitis, F. nucleatum, P. Gingivalis&lt;/i&gt; and &lt;i&gt;A. Actinomycetemcomitans&lt;/i&gt; was created to represent a disease-associated biofilm and the oral epithelial cell in OKF6-TERT2. Cytotoxicity studies were performed using RSV and CHX. Multi-species biofilms were either treated with either molecule, or alternatively epithelial cells were treated with these prior to biofilm co-culture. Biofilm composition was evaluated and inflammatory responses quantified at a transcriptional and protein level.&lt;p&gt;&lt;/p&gt; Results: CHX was toxic to epithelial cells and multi-species biofilms at concentrations ranging from 0.01-0.2%. RSV did not effect multi-species biofilm composition, but was toxic to epithelial cells at concentrations greater than 0.01%. In co-culture, CHX-treated biofilms resulted in down regulation of the inflammatory chemokine IL-8 at both mRNA and protein level. RSV-treated epithelial cells in co-culture were down-regulated in the release of IL-8 protein, but not mRNA.&lt;p&gt;&lt;/p&gt; Conclusions: CHX possesses potent bactericidal properties, which may impact downstream inflammatory mediators. RSV does not appear to have bactericidal properties against multi-species biofilms, however it did appear to supress epithelial cells from releasing inflammatory mediators. This study demonstrates the potential to understand the mechanisms by which different oral hygiene products may influence gingival inflammation, thereby validating the use of a biofilm co-culture model.&lt;p&gt;&lt;/p&gt

Textile industry manufacturing by-products induce human melanoma cell proliferation via ERK1/2 activation

OBJECTIVES: Textiles used to make clothing can represent a source, often ignored, of chemicals potentially noxious to both skin and the whole organism. Among the most frequently produced potentially noxious chemical manufacturing by-products are formaldehyde (FA), nickel (Ni) and hexavalent chromium (Cr); they are of potential clinical interest as all are known to be carcinogenic to humans and to be potent skin sensitizers. The aim of this study was to investigate, in vitro, effects of these potentially dangerous compounds on two different melanoma cell lines. In particular, attention was focused on A375P, a poorly metastatic and low invasive cell line and SK-MEL-28, a highly metastatic cell line. MATERIALS AND METHODS: Effects of these compounds was evaluated on A375P and SK-MEL-28 cells. FA (1-5 7 10(-5) m), NiSO4 (10(-6) -10(-3) m), K2 Cr2 O7 (10(-7) -10(-6) m) effects on cell proliferation were evaluated by cell counting, while ERK pathway involvement was evaluated by Western blot analysis. RESULTS: Low concentrations of the chemicals, covering a range that corresponds to commonly accepted limits in textile production, induced a significant increase in cell proliferation concomitant with transient activation of phosphorylated ERK expression. CONCLUSIONS: Data obtained suggest that increasing attention must be focused on these by-products' potentially harmful effects in chemical manufacturing of clothes and accessories, that remain for long periods of time, in contact with human skin