Self consistent determination of plasmonic resonances in ternary nanocomposites

We have developed a self consistent technique to predict the behavior of plasmon resonances in multi-component systems as a function of wavelength. This approach, based on the tight lower bounds of the Bergman-Milton formulation, is able to predict experimental optical data, including the positions, shifts and shapes of plasmonic peaks in ternary nanocomposites without using any ftting parameters. Our approach is based on viewing the mixing of 3 components as the mixing of 2 binary mixtures, each in the same host. We obtained excellent predictions of the experimental optical behavior for mixtures of Ag:Cu:SiO2 and alloys of Au-Cu:SiO2 and Ag-Au:H2 O, suggesting that the essential physics of plasmonic behavior is captured by this approach.Comment: 7 pages and 4 figure

Charge-storage process of stoichiometric and nanostructured ruthenium nitride thin films

Ti-supported RuN thin films, synthesized by rf-magnetron sputtering, have been electrochemically characterized, focusing in particular to their charge-storage capacity, and to the mechanisms that influence this important property, in view, e.g., of applications in supercapacitors. Based on cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) data, a deconvolution of non-faradic and faradic contributions has been attempted, and a mechanism for the charging/discharging process has been proposed

The experience of regular exercise participation for women moving into their middle years : its nature, meaning and its benefits

This study added to the limited research on positive aspects of the human condition. It highlighted the perspective that women in western society recognise that there are wider health benefits to be taken from exercise than science suggests. Whilst this study acknowledged the customary fragmentary view, it took a holistic approach to exploring the nature and meaning of regular participation in exercise from the perspective of 41 women aged 30 to 50 years. This qualitative study included the views of regular participants in facility based and non-facility based exercise, along with the views of exercise instructors and the researcher. The study was contextualised within the traditional theories of related disciplines, namely health, women's studies, and exercise science. Also it was founded on the fitness industry's perspective on its service provision and its instructor training. Theory was compared with the experiences of a sector of the female population who, despite all the accepted calls on their time and energy, consistently maintained regular involvement in exercise. The study provided a holistic perspective on the nature, meaning and benefits of regular participation in exercise. Semi-structured interviews and focus groups were utilised in the data gathering process. In each case, the process consisted of a series of questions designed to explore a subjective perception of experience in accordance with the Neuro-Logical Levels process, a model from within the field of Neuro-Linguistic Programming (Dilts, 1990; Dilts, Hallbom and Smith, 1990; O'Connor and Seymour, 1995). This model acknowledges that behaviours and actions, witnessed on a surface level, are driven by internal systems, including personal beliefs and identity structures. It was utilised as an exploratory technique to identify unconscious triggers for behaviour. The use of this process in the interviews facilitated individual exploration of the research topic at increasingly deep levels of awareness. Focus groups demonstrated a consensus on, as well as further individual differences in, the beliefs, attitudes, experiences and feelings of the participants as they arose from the interactive context. The heuristic methodology utilised in the analysis and presentation of the data offered a holistic, person-centred and reflective perspective on the nature, meaning and benefits of exercise (Moustakas, 1990). Individual and exemplary portraits depicted the experience and personal meaning of exercise as it emerged from the data. Composite depictions conveyed the nature of exercise participation from the perspectives of participants and instructors. The researcher's involvement in the complete study facilitated the emergence of a creative synthesis of the essence of exercise. Exercise provided emotional and spiritual gains that extended beyond the traditional lifestyle benefits. Individuals indicated a range of 'special' qualities in exercise, along with benefits to the mind. They noted unique personal benefits and enhanced interpersonal relationships in all spheres of life. Regular participation in exercise greatly enhanced the lives of those involved and contributed to an individual and collective evolutionary process. Effective exercise delivery consisted of interactional and motivational elements beyond the scientific and mechanistic topics traditionally recognised in instructor training programmes and was founded on empathy, facilitation, passion, love and positive energy.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Nonlinear optical properties of Au–Ag nanoplanets made by ion beam processing of bimetallic nanoclusters in silica

The nonlinear absorption of Au–Ag nanoplanets made by Ar irradiation of bimetallic nanoclusters in silica has been experimentally investigated by means of the single beam z-scan technique. The measurements have been performed in the picoseconds regime in order to isolate the fast electronic contribution to the third-order nonlinearity. The results reveal large nonlinear absorption properties of these systems, characterized by the concomitance of saturable and reverse saturable absorption. A phenomenological expression has been developed to fit the z-scan curves and to quantitatively determine the nonlinear optical parameters

COPPER DIFFUSION IN ION-EXCHANGED SODA-LIME GLASS

Cu-alkali ion exchange in silicate glasses gives rise to a peculiar copper distribution, with the presence of both the Cu2+ and Cu+ oxidation states. Grazing incidence X-ray absorption near-edge structure spectroscopy and secondary ion mass spectrometry were performed on different ion-exchanged samples. The results show that the Cu2+/Cu+ ratio is strongly depth-dependent. The relative presence of the two species throughout the exchanged region turns out to be governed by their different diffusion regimes, while the chemistry of the redox process is shown to play a minor role. A phenomenological model is proposed to describe the diffusion process

Relationship between programmed cell death and the cell cycle in the tobacco BY-2 cell line

Ethylene is an established plant growth regulator linked with programmed cell death (PCD). To investigate the relationship between the cell cycle and PCD, ethylene was used to see if it induced mortality in a cell cycle specific manner. Tobacco BY-2 cultures synchronized with aphidicolin were treated with ethylene. Cell cycle progression and mortality, measured at hourly intervals, showed distinct peaks of mortality at the G2/M boundary and S-phase. In conjunction with this, DNA fragmentation increased at G2/M. Furthermore, ethylene caused a significant reduction in cell size of the cycling population. Simultaneous addition of silver nitrate with ethylene ameliorated ethylene-induced G2/M mortality, although a toxic effect of silver alone was evident. Due to the toxicity of silver, 1-MCP, an alternative chemical for blocking ethylene receptors was used. 1-MCP neither affected the BY-2 cell cycle nor mortality levels. In addition, 1-MCP ameliorated ethylene-induced G2/M mortality. To balance the chemical approaches to blocking ethylene receptors, tobacco BY-2 cells were transformed with Atetrl that encodes a dominant insensitive form of the Arabidopsis ETR1 ethylene receptor. Atetrl expression caused a massive perturbation to the tobacco BY-2 cell cycle, especially in S-phase, and resulted in high levels of mortality throughout the cell cycle. Ethylene treatment caused a doubling of G2 duration but did not affect temporal distribution of mortality. However, ethylene treatment generated a peak of mortality in S-phase. These results suggest that ethylene induces PCD at G2/M through the known ethylene signaling pathway. Furthermore, it confirms that 1-MCP and Atetrl result in ethylene insensitivity. To examine the G2/M transition, Spcdc25, a positive regulator of G2/M in fission yeast was transformed into the tobacco BY-2 cell line. This resulted in premature entry into mitosis, a shortened cell cycle, and reduced cell size. This was similar to Spcdc25 over-expression in fission yeast and suggests the presence of a CDC25-like phosphatase in plants.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Silver doping of silica-hafnia waveguides containing Tb3+/Yb3+ rare earths for downconversion in PV solar cells

The aim of this paper is to study the possibility to obtain an efficient downconverting waveguide which combines the quantum cutting properties of Tb3+/Yb3+ codoped materials with the optical sensitizing effects provided by silver doping. The preparation of 70SiO(2)-30HfO(2) glass and glass-ceramic waveguides by sol-gel route, followed by Ag doping by immersion in molten salt bath is reported. The films were subsequently annealed in air to induce the migration and/or aggregation of the metal ions. Results of compositional and optical characterization are given, providing evidence for the successful introduction of Ag in the films, while the photoluminescence emission is strongly dependent on the annealing conditions. These films could find potential applications as downshifting layers to increase the efficiency of PV solar cells. (C) 2016 Elsevier B.V. All rights reserved

Immunogenic cell death pathway polymorphisms for predicting oxaliplatin efficacy in metastatic colorectal cancer

Background Immunogenic cell death (ICD) is a tumor cell death involving both innate and adaptive immune responses. Given published findings that oxaliplatin, but not irinotecan, drives ICD, we investigated whether single nucleotide polymorphisms (SNPs) in the ICD pathway are associated with the efficacy of oxaliplatin-based chemotherapy in metastatic colorectal cancer (mCRC). Methods Two randomized clinical trials data were analyzed: discovery cohort, FOLFOX/bevacizumab arm (MAVERICC); validation cohort, FOLFOXIRI/bevacizumab arm (TRIBE); and two control cohorts, FOLFIRI/bevacizumab arms (both trials). Genomic DNA extracted from blood samples was genotyped. Ten SNPs in the ICD pathway were tested for associations with clinical outcomes. Results In total, 648 patients were included. In the discovery cohort, three SNPs were significantly associated with clinical outcomes in univariate analysis: CALR rs1010222 with progression-free survival (G/G vs any A, HR=0.61, 95% CI 0.43-0.88), ANXA1 rs1050305 with overall survival (OS) (A/A vs any G, HR=1.87, 95% CI 1.04-3.35), and LRP1 rs1799986 with OS (C/C vs any T, HR=1.69, 95% CI 1.07-2.70). Multivariate analysis confirmed the trend, but statistical significance was not reached. In the validation cohort, ANXA1 rs1050305, and LRP1 rs1799986 were validated to have the significant associations with clinical outcome. No significant associations of these SNPs were observed in the two control cohorts. Treatment-by-SNP interaction test confirmed the predictive values. Conclusions The predictive utility of ICD-related SNPs for the efficacy of oxaliplatin-based chemotherapy was demonstrated, warranting further validation studies to be translated into personalized treatment strategies using conventional cytotoxic agents in mCRC

SILVER-SENSITIZED ERBIUM-DOPED ION-EXCHANGED SOL-GEL WAVEGUIDES

Ag- and Er-doped glass films have been synthesized with a combined sol–gel and ion-exchange route. The introduction of silver as erbium sensitizer in the film was obtained by ion exchanging Er-doped SiO2–Al2O3–Na2O sol–gel films. The films were subsequently annealed under controlled atmosphere to induce the migration and aggregation of the metal ions. Films showed different Er3+ photoluminescence behaviors depending on silver concentration and aggregation state. The interaction between erbium ions and Ag centers has been investigated and enhancement of the excitation cross section due to the silver sensitizing effect has been demonstrated. The developed synthesis also allowed the realization of erbiumdoped channel waveguides by a selective Na–Ag ion-exchange process

Fertilizing Nature: A Tragedy of Excess in the Commons

Why has nitrogen fertilizer use declined in some countries while increasing in others, despite significant environmental harm? Proper crop management strategies offer environmental and economic benefits without sacrificing yields