998 resultados para 12930-007


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Introduction The number of revision hip arthroplasties is increasing but several aspects of this procedure could be improved. One method of reducing intra-operative complications is the cement-in-cement technique. This procedure entails cementing a smaller femoral prosthesis into the existing stable cement mantle. The aim of this systematic review is to provide a concise overview of the existing historical, operative, biomechanical and clinical literature on the cement-in-cement construct.

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The convergence of the iterative identification algorithm for a general Hammerstein system has been an open problem for a long time. In this paper, it is shown that the convergence can be achieved by incorporating a regularization procedure on the nonlinearity in addition to a normalization step on the parameters.

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In this paper we examine the properties of stable coalitions under sequential and simultaneous bargaining by competing labor unions. We do this using the Nash bargaining solution and various notions of stability, namely, Nash, coalitional, contractual and core stability. (C) 2011 Elsevier B.V. All rights reserved,

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Hydrogenation of tertiary amides, in particular, N-methylpyrrolidin-2-one, can be efficiently facilitated by a TiO(2)-supported bimetallic Pt/Re catalyst at low temperatures and pressures. Characterisation of the catalysts and kinetic tests have shown that the close interaction between the Re and Pt is crucial to the high activity observed. DFT calculations were used to examine a range of metal combinations and show that the role of the uncoordinated Re is to activate the C=O and that of the Pt is as a hydrogenation catalyst, removing intermediates from the catalyst surface. The rate enhancement observed on the TiO(2) support is thought to be due to the presence of oxygen vacancies allowing adsorption and weakening of the C=O bond. (C) 2011 Elsevier Inc. All rights reserved.

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The sonochemical oxidation efficiency (eta(ox)) of a commercial titanium alloy ultrasound horn has been measured using potassium iodide as a dosimeter at its main resonance frequency (20 kHz) and two higher resonance frequencies (41 and 62 kHz). Narrow power and frequency ranges have been chosen to minimise secondary effects such as changing bubble stability, and time available for radical diffusion from the bubble to the liquid. The oxidation efficiency, eta(ox), is proportional to the frequency and to the power transmitted to the liquid (275 mL) in the applied power range (1-6 W) under argon. Luminol radical visualisation measurements show that the radical generation rate increases and a redistribution of radical producing zones is achieved at increasing frequency. Argon, helium, air, nitrogen, oxygen, and carbon dioxide have been used as saturation gases in potassium iodide oxidation experiments. The highest eta(ox) has been observed at 5 W under air at 62 kHz. The presence of carbon dioxide in air gives enhanced nucleation at 41 and 62 kHz and has a strong influence on eta(ox). This is supported by the luminol images, the measured dependence of eta(ox). on input power, and bubble images recorded under carbon dioxide. The results give insight into the interplay between saturation gas and frequency, nucleation, and their effect on eta(ox). (C) 2010 Elsevier B.V. All rights reserved.

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Evidence is accumulating that breast cancer is not one disease but many separate diseases. DNA microarray-based gene expression profiling has demonstrated subtypes with distinct phenotypic features and clinical responses. Prominent among the new subtypes is 'basal-like' breast cancer, one of the 'intrinsic' subtypes defined by negativity for the estrogen, progesterone, and HER2/neu receptors and positivity for cytokeratins-5/6. Focusing on basal-like breast cancer, we discuss how molecular technologies provide new chemotherapy targets, optimising treatment whilst sparing patients from un-necessary toxicity. Clinical trials are needed that incorporate long-term follow-up of patients with well-characterised tumour markers. Whilst the absence of an obvious dominant oncogene driving basallike breast cancer and the lack of specific therapeutic agents are serious stumbling blocks, this review will highlight several promising therapeutic candidates currently under evaluation. Thus, new molecular technologies should provide a fundamental foundation for better understanding breast and other cancers which may be exploited to save lives.

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This paper reports on work in developing a finite element (FE) based die shape optimisation for net-shape forging of 3D aerofoil blades for aeroengine applications. Quantitative representations of aerofoil forging tolerances were established to provide a correlation between conventional dimensional and shape specifications in forging production and those quantified in FE simulation. A new direct compensation method was proposed, employing variable weighting factors to minimise the total forging tolerances in forging optimisation computations. A surface approximation using a B-spline surface was also developed to ensure improved die surface quality for die shape representation and design. For a Ni-alloy blade test case, substantial reduction in dimensional and shape tolerances was achieved using the developed die shape optimisation system.

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Laying hens generally choose to aggregate, but the extent to which the environments in which we house them impact on social group dynamics is not known. In this paper the effect of pen environment on spatial clustering is considered. Twelve groups of four laying hens were studied under three environmental conditions: wire floor (W), shavings (Sh) and perches, peat, nestbox and shavings (PPN). Groups experienced each environment twice, for five weeks each time, in a systematic order that varied from group to group. Video recordings were made one day per week for 30 weeks. To determine level of clustering, we recorded positional data from a randomly selected 20-min excerpt per video (a total of 20 min x 360 videos analysed). On screen, pens were divided into six equal areas. In addition, PPN pens were divided into an additional four (sub) areas, to account for the use of perches (one area per half perch). Every 5 s, we recorded the location of each bird and calculated location use over time, feeding synchrony and cluster scores for each environment. Feeding synchrony and cluster scores were compared against unweighted and weighted (according to observed proportional location use) Poisson distributions to distinguish between resource and social attraction.

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This paper analyses the interaction between neoliberal inspired reforms of public services and the mechanisms for achieving public accountability. Where once accountability was exercised through the ballot box, now in the neoliberal age managerial and market based forms of accountability predominate. The analysis identifies resistance from civil society campaigns to the neoliberal restructuring of public services which leads to public accountability (PA) becoming a contested arena. To develop this analysis a re-theorisation of PA, as a relationship where civil society seeks to control the state, is explored in the context of social housing in England over the past thirty years. Central to this analysis is a dialogical analysis of key documents from a social housing regulator and civil society campaign. The analysis shows that the current PA practices are an outcome of both reforms from the government and resistance from civil society (in the shape of tenants’ campaigns). The outcome of which is to tell the story of the changes in PA (and accountability) centring on an analysis of discourse. Thus, the paper moves towards answering the question – what has happened to PA during the neoliberal age?

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a- and b-zearalenol (a-ZOL and b-ZOL, respectively) are metabolites of the mycotoxin zearalenone (ZEN). All three individual mycotoxins have shown to be biological active i.e. being estrogenic and able to stimulate cellular proliferation albeit at different strengths. In this work, cytosol protein expression was determined by using stable-isotope labelling by amino acids in cell culture (SILAC) upon exposure of a-ZOL and b-ZOL to the steroidogenesis cell model H295R. A total of 14 and 5 individual proteins were found to be significantly regulated by a-ZOL and b-ZOL, respectively. Interestingly, there were no common protein regulations by the metabolites or the parent mycotoxin ZEN. Furthermore, the regulated proteins were assigned to networks and groups of actions that also differed from one another suggesting that the three individual mycotoxins may have unique biological activities.

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Obtaining as much particulate material as possible from questioned items is desirable in forensic science as this allows a range of analyses to be undertaken and the retention of material for others to check. A method of maximising particulate recovery is described using a kidnap case, where minimal staining on clothing (socks) remained as possible indications of where the victim had been held captive. Police intelligence led to a hostage scene that was sampled. Brushing of the socks recovered about 50 sand grains with some silt: ultrasonic agitation and centrifuging recovered over 300 grains of sand, silt and clay. These were visually compared to scene and control samples, allowing exclusion of 52 samples and the retention of one comparison sample as well as other possibles, saving time and money, but maximising sample quantity and quality. © 2011 Elsevier Ireland Ltd.

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Objectives. We investigated whether exposure to negative aspects of close relationships was associated with subsequent increase in body mass index (BMI) and waist circumference.
Methods. Data came from a prospective cohort study (Whitehall II) of 9425 civil servants aged 35 to 55 years at baseline (phase 1: 1985-1988). We assessed negative aspects of close relationships with the Close Persons Questionnaire (range 0-12) at phases 1 and 2 (1989-1990). We measured BMI and waist circumference at phases 3 (1991-1994) and 5 (1997-1999). Covariates at phase 1 included gender, age, marital status, ethnicity, BMI, employment grade, smoking, physical activity, fruit and vegetable consumption, and common mental disorder.
Results. After adjustment for sociodemographic characteristics and health behaviors, participants with higher exposure to negative aspects of close relationships had a higher likelihood of a 10% or greater increase in BMI and waist circumference (odds ratios per 1-unit increase 1.08 [95% confidence interval (CI)=1.02, 1.14; P=.007] and 1.09 [CI=1.04, 1.14; P <= .001], respectively) as well as a transition from the overweight (25 <= BMI <30) to the obese (BMI >= 30) category.
Conclusions. Adverse social relationships may contribute to weight gain.

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The effect of Al incorporation and pH adjustment during hydrolysis of the silica precursor on the thermal and structural stability of ordered microporous silica films with a 2D structure is presented. The structural stability of the films was determined from a combination of LA XRD/TEM data with porosity data obtained from ethanol adsorption isotherms. Thermogravimetric analysis and MR data were used to determine the template removal and the thermal stability. Stability of aluminium incorporated silica films has further been examined in several organic solvents with different polarity. A solvent with a higher polarity interacts more strongly with the films; the long-order structure disappeared after exposure to polar solvents. After exposure to non-polar solvents, the pore size uniformity was retained after 48 h. The samples with an Al/Si ratio of 0.007 showed the smallest d-spacing shift after exposure to hexane. The stability was further tested in the hydrogenation of phenylacetylene performed in a batch reactor over 1 wt.% Pd/Si(Al)O-2/Si (Al/Si = 0.007) films at 30 degrees C and 10 bar H-2 with hexane as solvent. No deactivation was observed in two subsequent hydrogenation runs. (C) 2009 Elsevier Inc. All rights reserved.