Antibacterial Activity of Partially Oxidized Ag/Au Nanoparticles against the Oral Pathogen Porphyromonas gingivalis

Advances in nanotechnology provide opportunities for the prevention and treatment of periodontal disease. While physicochemical properties of Ag containing nanoparticles (NPs) are known to influence the magnitude of their toxicity, it is thought that nanosilver can be made less toxic to eukaryotes by passivation of the NPs with a benign metal. Moreover, the addition of other noble metals to silver nanoparticles, in the alloy formulation, is known to alter the silver dissolution behavior. Thus, we synthesized glutathione capped Ag/Au alloy bimetallic nanoparticles (NPs) via the galvanic replacement reaction between maltose coated Ag NPs and chloroauric acid (HAuCl4) in 5% aqueous triblock F127 copolymer solution. We then compared the antibacterial activity of the Ag/Au NPs to pure Ag NPs on Porphyromonas gingivalis W83, a key pathogen in the development of periodontal disease. Only partially oxidized glutathione capped Ag and Ag/Au (Au : Ag ≈ 0.2) NPs inhibited the planktonic growth of P. gingivalis W83. This effect was enhanced in the presence of hydrogen peroxide, which simulates the oxidative stress environment in the periodontal pocket during chronic inflammation

Cold-atom clock based on a diffractive optic

Clocks based on cold atoms offer unbeatable accuracy and long-term stability, but their use in portable quantum technologies is hampered by a large physical footprint. Here, we use the compact optical layout of a grating magneto-optical trap (gMOT) for a precise frequency reference. The gMOT collects 10 7 87Rb atoms, which are subsequently cooled to 20 µK in optical molasses. We optically probe the microwave atomic ground-state splitting using lin┴lin polarised coherent population trapping and a Raman-Ramsey sequence. With ballistic drop distances of only 0.5 mm, the measured short-term fractional frequency stability is 2 × 10 −11/√τ

Perceptions, use and attitudes of pharmacy customers on complementary medicines and pharmacy practice

BACKGROUND: Complementary medicines (CMs) are popular amongst Australians and community pharmacy is a major supplier of these products. This study explores pharmacy customer use, attitudes and perceptions of complementary medicines, and their expectations of pharmacists as they relate to these products. METHODS: Pharmacy customers randomly selected from sixty large and small, metropolitan and rural pharmacies in three Australian states completed an anonymous, self administered questionnaire that had been pre-tested and validated. RESULTS: 1,121 customers participated (response rate 62%). 72% had used CMs within the previous 12 months, 61% used prescription medicines daily and 43% had used both concomitantly. Multivitamins, fish oils, vitamin C, glucosamine and probiotics were the five most popular CMs. 72% of people using CMs rated their products as 'very effective' or 'effective enough'. CMs were as frequently used by customers aged 60 years or older as younger customers (69% vs. 72%) although the pattern of use shifted with older age. Most customers (92%) thought pharmacists should provide safety information about CMs, 90% thought they should routinely check for interactions, 87% thought they should recommend effective CMs, 78% thought CMs should be recorded in customer's medication profile and 58% thought pharmacies stocking CMs should also employ a complementary medicine practitioner. Of those using CMs, 93% thought it important for pharmacists to be knowledgeable about CMs and 48% felt their pharmacist provides useful information about CMs. CONCLUSIONS: CMs are widely used by pharmacy customers of all ages who want pharmacists to be more involved in providing advice about these products

Historical Sources of Institutional Trajectories in Economic Development: China, Japan, and Korea Compared

This essay provides a game-theoretic, endogenous view of institutions, and then applies the idea to identify the sources of institutional trajectories of economic development in China, Japan, and Korea. It stylizes the Malthusian-phase of East Asian economies as peasant-based economies in which small families allocated their working time between farming on small plots - leased or owned - and handcrafting for personal consumption and markets. It then compares institutional arrangements across these economies that sustained otherwise similar economies. It characterizes the varied nature of the political states of Qing China, Tokugawa Japan, and Yi Korea by focusing on the way in which agricultural taxes were enforced. It also identifies different patterns of social norms of trust that were institutional complements to, or substitutes for, political states. Finally, it traces the path-dependent transformations of these state-norm combinations along subsequent transitions to post-Malthusian phases of economic growth in the respective economies

Pregnancy, prescription medicines and the potential risk of herb-drug interactions:a cross-sectional survey

Funding All funding was from institutional resource. JSM, AS are employed by the University of Aberdeen. DS is employed by the Robert Gordon University. BP and CR are employed by NHS Scotland. ARP and MAH are employed by the Hamad Medical Corporation. Qatar. NI is a postgraduate student at the University of Aberdeen.Peer reviewedPublisher PD

Weak lensing of Type Ia Supernovae from the Dark Energy Survey

We consider the effects of weak gravitational lensing on observations of 196 spectroscopically confirmed Type Ia Supernovae (SNe Ia) from years 1 to 3 of the Dark Energy Survey (DES). We simultaneously measure both the angular correlation function and the non-Gaussian skewness caused by weak lensing. This approach has the advantage of being insensitive to the intrinsic dispersion of SNe Ia magnitudes. We model the amplitude of both effects as a function of $\sigma_8$, and find $\sigma_8 = 1.2^{+0.9}_{-0.8}$. We also apply our method to a subsample of 488 SNe from the Joint Light-curve Analysis (JLA) (chosen to match the redshift range we use for this work), and find $\sigma_8 = 0.8^{+1.1}_{-0.7}$. The comparable uncertainty in $\sigma_8$ between DES-SN and the larger number of SNe from JLA highlights the benefits of homogeneity of the DES-SN sample, and improvements in the calibration and data analysis.Comment: 10 pages, 7 figures, MNRA

Modeling Light Adaptation in Circadian Clock: Prediction of the Response That Stabilizes Entrainment

Periods of biological clocks are close to but often different from the rotation period of the earth. Thus, the clocks of organisms must be adjusted to synchronize with day-night cycles. The primary signal that adjusts the clocks is light. In Neurospora, light transiently up-regulates the expression of specific clock genes. This molecular response to light is called light adaptation. Does light adaptation occur in other organisms? Using published experimental data, we first estimated the time course of the up-regulation rate of gene expression by light. Intriguingly, the estimated up-regulation rate was transient during light period in mice as well as Neurospora. Next, we constructed a computational model to consider how light adaptation had an effect on the entrainment of circadian oscillation to 24-h light-dark cycles. We found that cellular oscillations are more likely to be destabilized without light adaption especially when light intensity is very high. From the present results, we predict that the instability of circadian oscillations under 24-h light-dark cycles can be experimentally observed if light adaptation is altered. We conclude that the functional consequence of light adaptation is to increase the adjustability to 24-h light-dark cycles and then adapt to fluctuating environments in nature

Dark energy survey year 3 results: Galaxy sample for BAO measurement

In this paper, we present and validate the galaxy sample used for the analysis of the baryon acoustic oscillation (BAO) signal in the Dark Energy Survey (DES) Y3 data. The definition is based on a colour and redshift-dependent magnitude cut optimized to select galaxies at redshifts higher than 0.5, while ensuring a high-quality determination. The sample covers ~4100 deg2 to a depth of i = 22.3 (AB) at 10s. It contains 7031 993 galaxies in the redshift range from z = 0.6 to 1.1, with a mean effective redshift of 0.835. Redshifts are estimated with the machine learning algorithm DNF, and are validated using the VIPERS PDR2 sample. We find a mean redshift bias of zbias~0.01 and a mean uncertainty, in units of 1 + z, of σ68~0.03. We evaluate the galaxy population of the sample, showing it is mostly built upon Elliptical to Sbc types. Furthermore, we find a low level of stellar contamination of ≤ 4 per cent. We present the method used to mitigate the effect of spurious clustering coming from observing conditions and other large-scale systematics.We apply it to the BAO sample and calculate weights that are used to get a robust estimate of the galaxy clustering signal. This paper is one of a series dedicated to the analysis of the BAO signal in DES Y3. In the companion papers, we present the galaxy mock catalogues used to calibrate the analysis and the angular diameter distance constraints obtained through the fitting to the BAO scale

Dark Energy Survey Year 1 results: galaxy clustering for combined probes

We measure the clustering of DES Year 1 galaxies that are intended to be combined with weak lensing samples in order to produce precise cosmological constraints from the joint analysis of large-scale structure and lensing correlations. Two-point correlation functions are measured for a sample of 6.6×10 5 luminous red galaxies selected using the \textsc{redMaGiC} algorithm over an area of 1321 square degrees, in the redshift range 0.15 0.5 , b(z =0.68)=1.93±0.05 for L/L ∗ > 1 and b(z =0.83)=1.99±0.07 for L/L ∗ >1.5 , broadly consistent with expectations for the redshift and luminosity dependence of the bias of red galaxies. We show these measurements to be consistent with the linear bias obtained from tangential shear measurements

Cosmological constraints from multiple probes in the dark energy survey

International audienceThe combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80-0.11+0.09. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ωb=0.069-0.012+0.009 that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade