Extended application of edge-to-edge matching model to HCP/HCP (alpha-Mg/MgZn2) system in magnesium alloys

In the present work, the edge-to-edge matching model has been introduced to predict the orientation relationships (OR) between the MgZn2 phase which has hexagonal close packed (HCP) structure and the HCP a-Mg matrix. Based on the crystal structures and lattice parameters only, the model has predicted the two most preferred ORs and they are: (1) [1 1 2 3](alpha-Mg) vertical bar vertical bar]1 1 2 3](alpha-Mg), (0 0 0 1)(alpha-Mg) 0.27 degrees from (0 0 0 1)(MgZn2), (1 0 1 1)(alpha-Mg) 26.18 degrees from (1 1 2 2)(MgZn2), (2) [1 0 1 0](alpha-Mg),vertical bar vertical bar[1 1 2 0](MgZn2), (0 0 0 1)(alpha-Mg) vertical bar vertical bar(0 0 0 1)(MgZn2), (1 0 1 1)(alpha-Mg) 3.28 degrees from ( 1 1 2 2)(MgZn2). Four experimental ORs have been reported in the alpha-Mg/MgZn2 system, and the most frequently reported one is ideally the OR (2). The other three experimental ORs are near versions of the OR (2). The habit plane of the OR (2) has been predicted and it agrees well with the experimental results.

High-resolution spectroscopy of globular cluster post-Asymptotic Giant Branch stars

We present model atmosphere analyses of high resolution Keck and VLT optical spectra for three evolved stars in globular clusters, viz. ZNG-1 in M 10, ZNG-1 in M 15 and ZNG-1 in NGC 6712. The derived atmospheric parameters and chemical compositions confirm the programme stars to be in the post- Asymptotic Giant Branch (post-AGB) evolutionary phase. Differential abundance analyses reveal CNO abundance patterns in M 10 ZNG-1, and possibly M 15 ZNG-1, which Suggest that both objects may have evolved off the AGB before the third dredge-up occurred. The abundance pattern of these stars is similar to the third class of optically, bright post-AGB objects discussed by van Winckel (1997). Furthermore, M 10 ZNG-1 exhibits a large C underabundance (with Delta[C/O] similar to -1.6 dex), typical of other hot post-AGB objects. Differential Delta[alpha/Fe] abundance ratios in both M 10 ZNG-1 and NGC 6712 ZNG-1 are found to be approximately 0.0 dex, with the Fe abundance of the former being in disagreement with the cluster metallicity of M 10. Given that the Fe absorption features in both M 10 ZNG-1 and NGC6712 ZNG-1 are well observed and reliably modelled, we believe that these differential Fe abundance estimates to be secure. However, our Fe abundance is difficult to explain in terms of previous evolutionary processes that Occur oil both the Horizontal Branch and the AGB.

A Cluster Randomized Controlled Trial of an Adapted U.S. Model of Pharmaceutical Care for Nursing Home Residents in Northern Ireland (Fleetwood Northern Ireland Study): A Cost-Effectiveness Analysis

OBJECTIVES: To evaluate the cost-effectiveness of an adapted U.S. model of pharmaceutical care to improve psychoactive prescribing for nursing home residents in Northern Ireland (Fleetwood NI Study).
DESIGN: Economic evaluation alongside a cluster randomized controlled trial.
SETTING: Nursing homes in NI randomized to intervention (receipt of the adapted model of care; n511) or control (usual care continued; n511).
PARTICIPANTS: Residents aged 65 and older who provided informed consent (N5253; 128 intervention, 125 control) and who had full resource use data at 12 months.
INTERVENTION: Trained pharmacists reviewed intervention home residents’ clinical and prescribing information for 12 months, applied an algorithm that guided them in assessing the appropriateness of psychoactive medication, and worked with prescribers (general practitioners) to make changes. The control homes received usual care in which there was no pharmacist intervention.
MEASUREMENTS: The proportion of residents prescribed one or more inappropriate psychoactive medications (according to standardized protocols), costs, and a cost-effectiveness acceptability curve. The latter two outcomes are the focus for this article.
RESULTS: The proportions of residents receiving inappropriate psychoactive medication at 12 months in the intervention and control group were 19.5% and 50.4%, respectively. The mean cost of healthcare resources used per resident per year was $4,923 (95% con?dence interval.

1/f(alpha) fluctuations in a ricepile model

The temporal fluctuation of the average slope of a ricepile model is investigated. It is found that the power spectrum S(f) scales as 1/f(alpha) with alpha approximate to 1.3 when grains of rice are added only to one end of the pile. If grains are randomly added to the pile, the power spectrum exhibits 1/f(2) behavior. The profile fluctuations of the pile under different driving mechanisms are also discussed.

Assessment of the usability of the 'alpha' version of the prototype 'Octopus'-application of the heuristic evaluation model of user's graphic interfaces. 'Evaluación de la utilidad de la versión 'alfa' del prototipo 'Octopus'-uso del modelo de evaluación heurístico de los interfaces gráficos del usuario'.

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Comparative investigation of the cleavage step in the synthesis of model peptide resins: Implications for N-alpha-9-fluorenylmethyloxycarbonyl-solid phase peptide synthesis

Based on our studies of the stability of model peptide-resin linkage in acid media, we previously proposed a rule for resin selection and a final cleavage protocol applicable to the N-alpha-tert-butyloxycarbonyl (Boc)-peptide synthesis strategy. We found that incorrect choices resulted in decreases in the final synthesis yield, which is highly dependent on the peptide sequence, of as high as 30%. The present paper continues along this line of research but examines the N-alpha-9-fluorenylmethyloxycarbonyl (Fmoc)-synthesis strategy. The vasoactive peptide angiotensin II (All, DRVYIHPF) and its [Gly(8)]-All analogue were selected as model peptide resins. Variations in parameters such as the type of spacer group (linker) between the peptide backbone and the resin, as well as in the final acid cleavage protocol, were evaluated. The same methodology employed for the Boc strategy was used in order to establish rules for selection of the most appropriate linker-resin conjugate or of the peptide cleavage method, depending on the sequence to be assembled. The results obtained after treatment with four cleavage solutions and with four types of linker groups indicate that, irrespective of the circumstance, it is not possible to achieve complete removal of the peptide chains from the resin. Moreover, the Phe-attaching peptide at the C-terminal yielded far less cleavage (50-60%.) than that observed with the Gly-bearing sequences at the same position (70-90%). Lastly, the fastest cleavage occurred with reagent K acid treatment and when the peptide was attached to the Wang resin.

Cluster Coordination and Photoluminescence Properties of alpha-Ag2WO4 Microcrystals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamic behavior of cluster observables for the 2d Ising model

We present results of our numerical study of the critical dynamics of percolation observables for the two-dimensional Ising model. We consider the (Monte Carlo) short-time evolution of the system with small initial magnetization and heat-bath dynamics. We find qualitatively different dynamic behaviors for the magnetization M and for Ω, the so-called strength of the percolating cluster, which is the order parameter of the percolation transition. More precisely, we obtain a (leading) exponential form for Ω as a function of the Monte Carlo time t, to be compared with the power-law increase encountered for M at short times. Our results suggest that, although the descriptions in terms of magnetic or percolation order parameters may be equivalent in the equilibrium regime, greater care must be taken to interpret percolation observables at short times.

Multiple particle and cluster emissions from Zr following intermediate energies photo absorption

A new approach based on a N-a cluster photoabsorption model is proposed for the understanding of the puzzling steady increase behavior of the 90Zr (e, α) yield measured at the National Bureau of Standards (NBS) within the Giant Dipole Resonance and quasideuteron energy range. The calculation takes into account the pre-equilibrium emissions of protons, neutrons and alpha particles in the framework of an extended version of the multicollisional intranuclear cascade model (MCMC). Another Monte Carlo based algorithm describes the statistical decay of the compound nucleus in terms of the competition between particle evaporation (p, n, d, α, 3He and t) and nuclear fission. The results reproduce quite successfully the 90Zr (e,α) yield, suggesting that emissions of a particles are essential for the interpretation of the exotic increase of the cross sections.

Diabetes reduces mesenchymal stem cells in fracture healing through a TNF alpha-mediated mechanism

Diabetes interferes with bone formation and impairs fracture healing, an important complication in humans and animal models. The aim of this study was to examine the impact of diabetes on mesenchymal stem cells (MSCs) during fracture repair.Fracture of the long bones was induced in a streptozotocin-induced type 1 diabetic mouse model with or without insulin or a specific TNF alpha inhibitor, pegsunercept. MSCs were detected with cluster designation-271 (also known as p75 neurotrophin receptor) or stem cell antigen-1 (Sca-1) antibodies in areas of new endochondral bone formation in the calluses. MSC apoptosis was measured by TUNEL assay and proliferation was measured by Ki67 antibody. In vitro apoptosis and proliferation were examined in C3H10T1/2 and human-bone-marrow-derived MSCs following transfection with FOXO1 small interfering (si)RNA.Diabetes significantly increased TNF alpha levels and reduced MSC numbers in new bone area. MSC numbers were restored to normal levels with insulin or pegsunercept treatment. Inhibition of TNF alpha significantly reduced MSC loss by increasing MSC proliferation and decreasing MSC apoptosis in diabetic animals, but had no effect on MSCs in normoglycaemic animals. In vitro experiments established that TNF alpha alone was sufficient to induce apoptosis and inhibit proliferation of MSCs. Furthermore, silencing forkhead box protein O1 (FOXO1) prevented TNF alpha-induced MSC apoptosis and reduced proliferation by regulating apoptotic and cell cycle genes.Diabetes-enhanced TNF alpha significantly reduced MSC numbers in new bone areas during fracture healing. Mechanistically, diabetes-enhanced TNF alpha reduced MSC proliferation and increased MSC apoptosis. Reducing the activity of TNF alpha in vivo may help to preserve endogenous MSCs and maximise regenerative potential in diabetic patients.

OXYGEN ABUNDANCES IN LOW- AND HIGH-alpha FIELD HALO STARS AND THE DISCOVERY OF TWO FIELD STARS BORN IN GLOBULAR CLUSTERS

Oxygen abundances of 67 dwarf stars in the metallicity range -1.6 < [Fe/H] < -0.4 are derived from a non-LTE analysis of the 777 nm O I triplet lines. These stars have precise atmospheric parameters measured by Nissen and Schuster, who find that they separate into three groups based on their kinematics and alpha-element (Mg, Si, Ca, Ti) abundances: thick disk, high-alpha halo, and low-alpha halo. We find the oxygen abundance trends of thick-disk and high-alpha halo stars very similar. The low-alpha stars show a larger star-to-star scatter in [O/Fe] at a given [Fe/H] and have systematically lower oxygen abundances compared to the other two groups. Thus, we find the behavior of oxygen abundances in these groups of stars similar to that of the a elements. We use previously published oxygen abundance data of disk and very metal-poor halo stars to present an overall view (-2.3 < [Fe/H] < +0.3) of oxygen abundance trends of stars in the solar neighborhood. Two field halo dwarf stars stand out in their O and Na abundances. Both G53-41 and G150-40 have very low oxygen and very high sodium abundances, which are key signatures of the abundance anomalies observed in globular cluster (GC) stars. Therefore, they are likely field halo stars born in GCs. If true, we estimate that at least 3% +/- 2% of the local field metal-poor star population was born in GCs.

Cluster Coordination and Photoluminescence Properties of alpha-Ag2WO4 Microcrystals

In this paper, we report our initial research to obtain hexagonal rod-like elongated silver tungstate (alpha-Ag2WO4) microcrystals by different methods [sonochemistry (SC), coprecipitation (CP), and conventional hydrothermal (CH)] and to study their cluster coordination and optical properties. These microcrystals were structurally characterized by X-ray diffraction (XRD), Rietveld refinements, Fourier transform infrared (FT-IR), X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopies. The shape and average size of these alpha-Ag2WO4 microcrystals were observed by field-emission scanning electron microscopy (FE-SEM). The optical properties of these microcrystals were investigated by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) measurements. XRD patterns and Rietveld refinement data confirmed that alpha-Ag2WO4 microcrystals have an orthorhombic structure. FT-IR spectra exhibited four IR-active modes in a range from 250 to 1000 cm(-1). XANES spectra at the W L-3-edge showed distorted octahedral [WO6] clusters in the lattice, while EXAFS analyses confirmed that W atoms are coordinated by six O atoms. FE-SEM images suggest that the alpha-Ag2WO4 microcrystals grow by aggregation and the Ostwald ripening process. PL properties of alpha-Ag2WO4 microcrystals decrease with an increase in the optical band-gap values (3.19-3.23 eV). Finally, we observed that large hexagonal rod-like alpha-Ag2WO4 microcrystals prepared by the SC method exhibited a major PL emission intensity relative to alpha-Ag2WO4 microcrystals prepared by the CP and CH methods.