Few prospective studies have reported dietary risk factors for ovarian cancer. A total of 71 histologically confirmed epithelial ovarian cancers occurred among 13,281 non-Hispanic white California Seventh-day Adventist women during follow-up. Participants were part of the Adventist Health Study (AHS) and had no history of cancer or hysterectomy at baseline in 1976 when they completed a detailed lifestyle questionnaire including a dietary assessment. The association of dietary variables with either all ovarian cancer cases or postmenopausal cases was tested using proportional hazards regression with adjustment for age and other covariates. The strongest hazardous risk factor associations among the food variables were found for meat intake with a risk ratio (RR) of 2.42 for intake > or = 1 time/week versus no meat (p for trend = 0.006), and cheese intake with a RR of 2.02 for intake of > 2 time/week versus < 1 per week (p for trend = 0.10), both of these being in postmenopausal cases. We found significantly reduced risk of all ovarian cancer with higher tomato consumption (RR = 0.32) comparing intakes > or = five times/week versus never to < 1 time/week (p for trend = 0.002), and also with higher fruit consumption (p < 0.01). A weak protective association was found with low fat, but not whole milk. Little confounding was observed between these foods.

In the present work, the effect of graphene oxide (GO) nanosheets on the antibacterial activity of CuO nanowire arrays under visible light irradiation is shown. A combined thermal oxidation/electrophoretic deposition technique was employed to prepare three-dimensional networks of graphene oxide nanosheets hybridized with vertically aligned CuO nanowires. With the help of standard antibacterial assays and X-ray photoelectron spectroscopy, it is shown that the light-activated antibacterial response of the hybrid material against gram-negative Escherichia coli is significantly improved as the oxide functional groups of the GO nanosheets are reduced. In order to explore the physicochemical mechanism behind this behavior, ab-initio simulations based on density functional theory were performed and the effect of surface functional groups and hybridization were elucidated. Supported by the experiments, a three-step photo-antibacterial based mechanism is suggested: (i) injection of an electron from CuO into rGO, (ii) localization of the excess electron on rGO functional groups, and (iii) release of reactive oxygen species lethal to bacteria. Activation of new photoactive and physical mechanisms in the hybrid system makes rGO-modified CuO nanowire coatings as promising nanostructure devices for antimicrobial applications in particular for dry environments.

Efficient simultaneous adsorption of heavy metal ions from solutions by modified graphene oxide with 3-aminopyrazole using central composite design modeling.

Ultrathin and extra-large single-crystalline Au microflakes (Au MFs) have a huge potential in applications ranging from nanophotonics to catalysis. Yet, wet chemical synthesis approaches cannot access this size range due to the proportionality between growth time, thickness, and lateral size. Concurrently, complexity and small MF areas restrict the use of 2D template-based methods. In all cases, subsequent transfer to a substrate remains challenging. Here, we demonstrate a facile, gap-assisted synthesis method that enables on-substrate growth of ultrathin and extra-large Au MFs. In particular, using a 43 μm gap-size between two glass substrates and leveraging the directed-growth effect of halide ions, we achieve a high yield (∼90%) of Au MFs on glass with lateral sizes as high as 0.25 mm and thicknesses as low as 10 nm. Interestingly, for up to 25 h growth time, we observe a time-independent, ultralow average thickness of just 21 nm. A parametric synthesis study and an in-depth material characterization provide mechanistic insights into this extreme 2D growth mode. Overall, our gap-assisted approach greatly enhances the halide effect and results in a record-high aspect ratio of ∼104. It thus opens new opportunities for on-substrate anisotropic growth strategies that would benefit emerging optoelectronic and photoelectrochemical devices.

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In this study, pK a values of glycine, valine, phenylalanine, glycylvaline, and glycylphenylalanine were determined in aqueous solution by an ab initio method. To explain the acidic dissociation constants obtained, we investigated the molecular conformations and solute−solvent interactions of the peptides and amino acid anions, using the density functional theory (DFT) method. Several ionization reactions and equilibria in protic solvents, which possess a high hydrogen-band-donor capability, are shown. The mentioned reactions and equilibria constitute the indispensable theoretical basis to calculate the acidity constants of glycine, valine, phenylalanine, glycylvaline, and glycylphenylalanine. Basis sets at the B3LYP/6-31+G(d) level of theory were used for calculations. Tomasi’s method was used to analyze the formation of intermolecular hydrogen bonds between the existent species and water molecules. In this way, it was determined that in alkaline aqueous solutions the cation, anion, and neutral species of glycine, valine, phenylalanine, glycylvaline, and glycylphenylalanine are solvated with one, two, three, and four molecules of water, respectively. In this study, there is comparable agreement between the experimentally determined pK a values for the acid−base reactions selected by potentiometric and those reported in the literature demonstrating the theoretically calculated pK a values.

A novel, green and rapid sonochemical research to preparation of the biphenyls was carried out through the coupling reaction between various aryl halides and phenylboronic acid by using bis(propyl malononitrile) Ni (0) complex (NiFeO@SiO-BPMN-Ni) as an efficient nano catalyst. The catalyst can be recycled via an external magnet and reused several times without considerable loss of its catalytic activity. Compare to the previous works, this procedure has advantages such as easy workup, high yields of products, environmentally benign and short reaction times. The novel nickel catalyst prepared and characterized by FT-IR, XRD, SEM, EDX, TGA and VSM techniques.

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