38 resultados para 13200-045


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The objective of this research was to determine the surface temperature of a high pressure die casting die during casting conditions. This was achieved by instrumentation of an insert which was placed in the shotplate region of the die. This research overcame the challenge of directly measuring the die surface temperature during a HPDC production casting cycle and shows that this is an effective method to determine the die surface temperature during the casting cycle. The instrumentation results gave a peak and minimum temperature of 500 C and 240 C respectively during steady state running conditions with a molten aluminium casting temperature of 660 C. Stress analysis from the steady state measured temperature of the die surface was calculated through a simple FEA model and the resulting stress uctuation was applied to a fatigue equation for the die material, the predicted number of cycles for cracking to start was found to correlate well with observed die damage.

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Morphometric study of modern ice masses is useful because many reconstructions of glaciers traditionally draw on their shape for guidance Here we analyse data derived from the surface profiles of 200 modern ice masses-valley glaciers icefields ice caps and ice sheets with length scales from 10º to 10³ km-from different parts of the world Four profile attributes are investigated relief span and two parameters C* and C that result from using Nye s (1952) theoretical parabola as a profile descriptor C* and C respectively measure each profile s aspect ratio and steepness and are found to decrease in size and variability with span This dependence quantifies the competing influences of unconstrained spreading behaviour of ice flow and bed topography on the profile shape of ice masses which becomes more parabolic as span Increases (with C* and C tending to low values of 2.5-3.3 m ½) The same data reveal coherent minimum bounds in C* and C for modern ice masses that we develop into two new methods of palaeo glacier reconstruction In the first method glacial limits are known from moraines and the bounds are used to constrain the lowest palaeo ice surface consistent with modern profiles We give an example of applying this method over a three-dimensional glacial landscape in Kamchatka In the second method we test the plausibility of existing reconstructions by comparing their C* and C against the modern minimum bounds Of the 86 published palaeo ice masses that we put to this test 88% are found to be plausible The search for other morphometric constraints will help us formalise glacier reconstructions and reduce their uncertainty and subjectiveness

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A study undertaken at the University of Liverpool has investigated the potential for using construction and demolition waste (C&DW) derived aggregate in the manufacture of a range of precast concrete products, i.e. building and paving blocks and pavement flags. Phase III, which is reported here, investigated
concrete pavement flags. This was subsequent to studies on building and paving blocks. Recycled demolition aggregate can be used to replace newly quarried limestone aggregate, usually used in coarse (6 mm) and fine (4 mm-to-dust) gradings. The first objective was, as was the case with concrete building
and paving blocks, to replicate the process used by industry in fabricating concrete pavement flags in the laboratory. The ‘‘wet’’ casting technique used by industry for making concrete flags requires a very workable mix so that the concrete flows into the mould before it is compressed. Compression squeezes out water from the top as well as the bottom of the mould. This industrial casting procedure was successfully replicated in the laboratory by using an appropriately modified cube crushing machine and a special mould typical of what is used by industry. The mould could be filled outside of the cube crushing machine and then rolled onto a steel frame and into the machine for it to be compressed. The texture and mechanical properties of the laboratory concrete flags were found to be similar to the factory ones. The experimental work involved two main series of tests, i.e. concrete flags made with concrete- and
masonry-derived aggregate. Investigation of flexural strength was required for concrete paving flags. This is different from building blocks and paving blocks which required compressive and tensile splitting strength respectively. Upper levels of replacement with recycled demolition aggregate were determined
that produced similar flexural strength to paving flags made with newly quarried aggregates, without requiring an increase in the cement content. With up to 60% of the coarse or 40% of the fine fractions replaced with concrete-derived aggregates, the target mean flexural strength of 5.0 N/mm2 was still
achieved at the age of 28 days. There was similar detrimental effect by incorporating the fine masonry-derived aggregate. A replacement level of 70% for coarse was found to be satisfactory and also conservative. However, the fine fraction replacement could only be up to 30% and even reduced to 15% when used for mixes where 60% of the coarse fraction was also masonry-derived aggregate.

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In reconstructive surgery, skeletal muscle may endure protracted ischemia before reperfusion, which can lead to significant ischemia/reperfusion injury. Ischemic postconditioning induced by brief cycles of reperfusion/reocclusion at the end of ischemia has been shown to salvage skeletal muscle from ischemia/reperfusion injury in several animal models. However, ischemic postconditioning has not been confirmed in human skeletal muscle. Using an established in vitro human skeletal muscle hypoxic conditioning model, we tested our hypothesis that hypoxic postconditioning salvages ex vivo human skeletal muscle from hypoxia/reoxygenation injury and the mechanism involves inhibition of opening of the mitochondrial permeability transition pore (mPTP) and preservation of ATP synthesis. Muscle strips (~0.5×0.5×15mm) from human rectus abdominis muscle biopsies were cultured in Krebs-Henseleit-HEPES buffer, bubbled with 95%N(2)/5%CO(2) (hypoxia) or 95%O(2)/5%CO(2) (reoxygenation). Samples were subjected to 3h hypoxia/2h reoxygenation. Hypoxic postconditioning was induced by one or two cycles of 5min reoxygenation/5min hypoxia after 3h hypoxia. Muscle injury, viability and ATP synthesis after 2h of reoxygenation were assessed by measuring lactate dehydrogenase (LDH) release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reduction and ATP content, respectively. Hypoxic postconditioning or treatment with the mPTP-opening inhibitors Cyclosporine A (CsA, 5×10(-6)M) or N-Methyl-4-isoleucine Cyclosporine (NIM811, 5×10(-6)M) 10min before reoxygenation decreased LDH release, increased MTT reduction and increased muscle ATP content (n=7 patients; P

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Abstract
Background Physical inactivity is a major public health concern, and more innovative approaches are urgently needed to address it. The UK Government supports the use of incentives and so-called nudges to encourage healthy behaviour changes, and has encouraged business sector involvement in public health through the Public Health Responsibility Deal. To test the effectiveness of provision of incentives to encourage adults to increase their physical activity, we
recruited 406 adults from a workplace setting (office-based) to take part in an assessor-blind randomised controlled trial.
Methods
We developed the physical activity loyalty card scheme, which integrates a novel physical activity tracking system with web-based monitoring (palcard). Participants were recruited from two buildings at Northern Ireland’s main
government offices and were randomly allocated (grouped by building [n=2] to reduce contamination) to either incentive group (n=199) or no incentive group (n=207). We included participants aged 16–65 years, based at the worksite 4 days or more per week and for 6 h or more per day, and able to complete 15 min of moderate-paced walking (self-report). Exclusion criteria included having received specific advice by a general practitioner not to exercise. A statistician not involved in administration of the trial prepared a computer-generated random allocation sequence. Random assignments were placed in individually numbered, sealed envelopes by the statistician to ensure concealment of allocation. Only the assessor was masked to assignment. Sensors were placed along footpaths and the gym in the workplace. Participants scanned their loyalty card at the sensor when undertaking physical activity (eg, walking), which logged activity. Participants in the incentive group monitored their physical activity, collected points, and received rewards (retail vouchers) for minutes of physical activity completed over the 12-week intervention. Rewards were vouchers sponsored by local retailers. Participants in the no incentive group used their loyalty card to self-monitor their physical activity but were not able to earn points or receive rewards. The primary outcome was change in minutes of moderate to vigorous physical activity with the Global Physical Activity Questionnaire, measured at baseline, week 12, and 6 months. Activity was objectively measured with the tracking system over the 12-week intervention. Mann Whitney U tests were done to assess change between groups.
Findings
The mean age of participants was 43·32 years (SD 9·37), and 272 (67%) were women. We obtained follow-up data from 353 (87%) participants at week 12 and 341 (84%) at 6 months. At week 12, participants in the incentive group increased moderate to vigorous physical activity by a median of 60 min per week (IQR –10 to 120) compared with 30 min per week (–60 to 90) in the no incentive group (p=0·05). At 6 months, participants in the incentive group had
increased their moderate to vigorous physical activity by 30 min per week (–60 to 100) from baseline compared with 0 min per week (–115 to 1110) in the no incentive group (p=0·099). We noted no significant differences between groups
for use of loyalty card (p=0·18). Participants in the incentive group recorded a mean of 60·22 min (95% CI 50·90–69·55) of physical activity per week with their loyalty card on week 1 and 23·56 min (17·06–30·06) at week 12, which was similar to that for those in the no incentive group (59·74 min, 51·24–68·23, at week 1; 20·25 min, 14·45–26·06, at week 12; p=0·94 for differences between groups at week 1; p=0·45 for differences between groups at week 12).
Interpretation:
Financial incentives showed a short-term behaviour change in physical activity. This innovative study contributes to the necessary evidence base, and has important implications for physical activity promotion and business engagement in health. The optimum incentive-based approach needs to be established. Results should be interpreted with some caution as the analyses of secondary outcomes were not adjusted for multiple comparisons.

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Using ion carbon beams generated by high intensity short pulse lasers we perform measurements of single shot mean charge equilibration in cold or isochorically heated solid density aluminum matter. We demonstrate that plasma effects in such matter heated up to 1 eV do not significantly impact the equilibration of carbon ions with energies 0.045-0.5 MeV/nucleon. Furthermore, these measurements allow for a first evaluation of semiempirical formulas or ab initio models that are being used to predict the mean of the equilibrium charge state distribution for light ions passing through warm dense matter.

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Purpose: To compare long-term cognitive outcomes of patients treated with surgical clipping or endovascular coiling after subarachnoid haemorrhage (SAH). Method: Retrospective matched cohort study assessed neuropsychological functioning at least 12 months after aneurysmal SAH treatment. Fourteen patients treated by endovascular coiling and nine patients treated by surgical clipping participated. After gaining written consent, a comprehensive neuropsychological battery was completed. Standardised tests were employed to assess pre-morbid and current intellectual functioning (IQ), attention, speed of information processing, memory and executive function as well as psychosocial functioning and affect. Results: Treatment groups were not significantly different in terms of age, pre-morbid IQ, time from injury to treatment or time since injury. A significant effect of treatment on full-scale IQ score (p = 0.025), performance IQ (p = 0.045) and verbal IQ score (p = 0.029), all favouring the coiled group was observed. A medium effect size between groups difference in immediate memory (p = 0.19, partial ?(2) = 0.08) was also observed. No significant between group differences on attention, executive functioning and speed of information processing measures or mood and psychosocial functioning were noted. Both groups reported increased anxiety and memory, attention and speed of information processing deficits relative to normative data. Conclusions: Study findings indicate fewer cognitive deficits following endovascular coiling. Cognitive deficits in the clipped group may be due in part to the invasive nature of neurosurgical clipping. Further prospective research with regard to long-term cognitive and emotional outcomes is warranted. [Box: see text].

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According to a current paradigm cardiovascular diseases can be initiated by exposure of vascular cells to qualitatively modified low-density lipoproteins (LDL). Capillary leakage, an early feature of diabetic retinopathy, results in the exposure of retinal pericytes to modified LDL, including glycated (G-LDL) and heavily oxidized glycated LDL (HOG-LDL). We demonstrate here that modified LDL inhibits the proliferation and survival of cultured human retinal pericytes. Modified LDL also induced DNA fragmentation in bovine retinal pericytes. Overall, HOG-LDL produced a significantly higher extent of cytotoxicity and apoptosis in retinal pericytes. These results indicate that exposure of pericytes to HOG-LDL could be implicated in the development of diabetic retinopathy.

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We describe, for the first time, the microbial characterisation of hydrogel-forming polymeric microneedle arrays and the potential for passage of microorganisms into skin following microneedle penetration. Uniquely, we also present insights into the storage stability of these hydroscopic formulations, from physical and microbiological viewpoints, and examine clinical performance and safety in human volunteers. Experiments employing excised porcine skin and radiolabelled microorganisms showed that microorganisms can penetrate skin beyond the stratum corneum following microneedle puncture. Indeed, the numbers of microorganisms crossing the stratum corneum following microneedle puncture were greater than 105 cfu in each case. However, no microorganisms crossed the epidermal skin. When using a 21G hypodermic needle, more than 104 microorganisms penetrated into the viable tissue and 106 cfu of Candida albicans and Staphylococcus epidermidis completely crossed the epidermal skin in 24 h. The hydrogel-forming materials contained no microorganisms following de-moulding and exhibited no microbial growth during storage, while also maintaining their mechanical strength, apart from when stored at relative humidities of 86%. No microbial penetration through the swelling microneedles was detectable, while human volunteer studies confirmed that skin or systemic infection is highly unlikely when polymeric microneedles are used for transdermal drug delivery. Since no pharmacopoeial standards currently exist for microneedle-based products, the exact requirements for a proprietary product based on hydrogel-forming microneedles are at present unclear. However, we are currently working towards a comprehensive specification set for this microneedle system that may inform future developments in this regard.

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Abstract
PURPOSE:
The optimal duration over which lung SBRT should be delivered is unknown. We conducted a randomized pilot study in patients treated with four fractions of lung SBRT delivered over 4 or over 11days.
METHODS:
Patients with a peripheral solitary lung tumor (NSCLC or pulmonary metastasis) ?5cm were eligible. For NSCLC lung tumors ?3cm, a dose of 48Gy in 4 fractions was used, otherwise 52Gy in 4 fractions was delivered. Patients were randomized to receive treatment over 4 consecutive days or over 11days. The primary end-point was acute grade ?2 toxicity. Secondary end-points included quality of life (QOL) assessed using the EORTC QLQ-C30 and QLQ-LC13 questionnaires.
RESULTS:
Fifty four patients were enrolled. More patients in the 11day group had respiratory symptoms at baseline. 55.6% patients treated over 4days and 33.3% of patients treated over 11days experienced acute grade ?2 toxicity (p=0.085). Dyspnea, fatigue and coughing domains were worse in the 11day group at baseline. At 1 and 4months, more patients in the 4day group experienced a clinically meaningful worsening in the dyspnea QOL domain compared to the 11day group (44.5% vs 15.4%, p=0.02; 38.5% vs 12.0%, p=0.03, respectively). However, raw QOL scores were not different at these time-points between treatment groups.
CONCLUSIONS:
Grade 2 or higher acute toxicity was more common in the 4day group, approaching statistical significance. More patients treated on 4 consecutive days reported a clinically meaningful increase in dyspnea, although interpretation of these results is challenging due to baseline imbalance between treatment groups. Larger studies are required to validate these results.

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Rice is comparatively efficient at assimilating inorganic arsenic (As i), a class-one, non-threshold carcinogen, into its grain, being the dominant source of this element to mankind. Here it was investigated how the total arsenic (Ast) and Asi content of Italian rice grain sourced from market outlets varied by geographical origin and type. Total Cr, Cd Se, Mg, K, Zn, Ni were also quantified. Ast concentration on a variety basis ranged from means of 0.18 mg kg-1 to 0.28 mg kg -1, and from 0.11 mg kg-1 to 0.28 mg kg-1 by production region. For Asi concentration, means ranged from 0.08 mg kg-1 to 0.11 mg kg-1 by variety and 0.10 mg kg -1 to 0.06 mg kg-1 by region. There was significant geographical variation for both Ast and Asi; total Se and Ni concentration; while the total concentration of Zn, Cr, Ni and K were strongly influenced by the type of rice.

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Objective
To investigate the effect of fast food consumption on mean population body mass index (BMI) and explore the possible influence of market deregulation on fast food consumption and BMI.

Methods
The within-country association between fast food consumption and BMI in 25 high-income member countries of the Organisation for Economic Co-operation and Development between 1999 and 2008 was explored through multivariate panel regression models, after adjustment for per capita gross domestic product, urbanization, trade openness, lifestyle indicators and other covariates. The possible mediating effect of annual per capita intake of soft drinks, animal fats and total calories on the association between fast food consumption and BMI was also analysed. Two-stage least squares regression models were conducted, using economic freedom as an instrumental variable, to study the causal effect of fast food consumption on BMI.

Findings
After adjustment for covariates, each 1-unit increase in annual fast food transactions per capita was associated with an increase of 0.033 kg/m2 in age-standardized BMI (95% confidence interval, CI: 0.013–0.052). Only the intake of soft drinks – not animal fat or total calories – mediated the observed association (β: 0.030; 95% CI: 0.010–0.050). Economic freedom was an independent predictor of fast food consumption (β: 0.27; 95% CI: 0.16–0.37). When economic freedom was used as an instrumental variable, the association between fast food and BMI weakened but remained significant (β: 0.023; 95% CI: 0.001–0.045).

Conclusion
Fast food consumption is an independent predictor of mean BMI in high-income countries. Market deregulation policies may contribute to the obesity epidemic by facilitating the spread of fast food.

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Background: Patient reported outcome measures (PROMs) are used to evaluate lifestyle interventions but littleis known about differences between patients returning valid and invalid responses, or of potential for bias inevaluations. We aimed to examine the characteristics of patients who returned valid responses to lifestylequestionnaires compared to those whose responses were invalid for evaluating lifestyle change. 
Methods: We conducted a secondary data analysis from the SPHERE Study, a trial of an intervention to improveoutcomes for patients with coronary heart disease in primary care. Postal questionnaires were used to assessphysical activity (Godin) and diet (DINE) among study participants at baseline and 18 month follow-up. Three binaryresponse variables were generated for analysis: (1) valid Godin score; (2) valid DINE Fibre score; and (3) validDINE Total Fat score. Multivariate analysis comprised generalised estimating equation regression to examine theassociation of patients’ characteristics with their return of valid responses at both timepoints. 
Results: Overall, 92.1% of participants (832/903) returned questionnaires at both baseline and 18 months. Relativelyfewer valid Godin scores were returned by those who left school aged <15 years (36.5%) than aged 18 and over(50.5%), manual workers (39.5%) than non-manual (49.5%) and those with an elevated cholesterol (>5 mmol)(34.7%) than those with a lower cholesterol (44.4%) but multivariate analysis identified that only school leaving age(p = 0.047) was of statistical significance.Relatively fewer valid DINE scores were returned by manual than non-manual workers (fibre: 80.8% v 86.8%;fat: 71.2% v 80.0%), smokers (fibre: 72.6% v 84.7%; fat: 67.5% v 76.9%), patients with diabetes (fibre: 75.9% v 82.9%;fat: 66.9% v 75.8%) and those with cholesterol >5 mmol (fat: 68.2% v 76.2%) but multivariate analysis showedstatistical significance only for smoking (fibre: p = 0.013; fat: p = 0.045), diabetes (fibre: p = 0.039; fat: p = 0.047), andcholesterol (fat: p = 0.039). 
Conclusions: Our findings illustrate the importance of detailed reporting of research methods, with clearinformation about response rates, respondents and valid outcome data. Outcome measures which are relevant to astudy population should be chosen carefully. The impact of methods of outcome measurement and valid responserates in evaluating healthcare requires further study.

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The aim of this paper is to develop a new extruder control system for recycled materials which has ability to automatically maintain constant a polymer melt viscosity of mixed recycled polymers during extrusion, regardless of variations in the Melt Flow Index (MFI) of recycled mixed grade high density polyethylene (HDPE) feedstock. A closed-loop controller is developed to automatically regulate screw speed and barrel temperature profile to achieve constant viscosity and enable consistent processing of variable grade recycled HDPE materials. The experimental results of real time viscosity measurement and control using a 38mm single screw extruder with different recycled HDPEs with widely different MFIs are reported in this work