12 resultados para treatment effect

em Aston University Research Archive


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Purpose: Eicosapentaenoic acid (EPA) has been proposed to have specific anticachectic effects. This trial compared EPA diethyl ester with placebo in cachectic cancer patients for effects on weight and lean body mass. Patients and Methods: Five hundred eighteen weight-losing patients with advanced gastrointestinal or lung cancer were studied in a multicenter, double-blind, placebo controlled trial. Patients were randomly assigned to receive a novel preparation of pure EPA at a dose of 2 g or 4 g daily or placebo (2g EPA, n = 175; 4 g EPA, n = 172; placebo, n = 171). Patients were assessed at 4 weeks and 8 weeks. Results: The groups were well balanced at baseline. Mean weight loss at baseline was 18% (n = 518). Over the 8-week treatment period, both intention-to-treat analysis and per protocol analysis revealed no statistically significant improvements in survival, weight, or other nutritional variables. There was, however, a trend in favor of EPA with analysis of the primary end point, weight, at 8 weeks showing a borderline, nonsignificant treatment effect (P = .066). Relative to placebo, mean weight increased by 1.2 kg with 2 g EPA (95% CI, 0 kg to 2.3 kg) and by 0.3 kg with 4g EPA (-0.9 kg to 1.5 kg). Conclusion: The results indicate no statistically significant benefit from single agent EPA in the treatment of cancer cachexia. Future studies should concentrate on other agents or combination regimens. © 2006 by American Society of Clinical Oncology.

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Background: We introduced a series of computer-supported workshops in our undergraduate statistics courses, in the hope that it would help students to gain a deeper understanding of statistical concepts. This raised questions about the appropriate design of the Virtual Learning Environment (VLE) in which such an approach had to be implemented. Therefore, we investigated two competing software design models for VLEs. In the first system, all learning features were a function of the classical VLE. The second system was designed from the perspective that learning features should be a function of the course's core content (statistical analyses), which required us to develop a specific-purpose Statistical Learning Environment (SLE) based on Reproducible Computing and newly developed Peer Review (PR) technology. Objectives: The main research question is whether the second VLE design improved learning efficiency as compared to the standard type of VLE design that is commonly used in education. As a secondary objective we provide empirical evidence about the usefulness of PR as a constructivist learning activity which supports non-rote learning. Finally, this paper illustrates that it is possible to introduce a constructivist learning approach in large student populations, based on adequately designed educational technology, without subsuming educational content to technological convenience. Methods: Both VLE systems were tested within a two-year quasi-experiment based on a Reliable Nonequivalent Group Design. This approach allowed us to draw valid conclusions about the treatment effect of the changed VLE design, even though the systems were implemented in successive years. The methodological aspects about the experiment's internal validity are explained extensively. Results: The effect of the design change is shown to have substantially increased the efficiency of constructivist, computer-assisted learning activities for all cohorts of the student population under investigation. The findings demonstrate that a content-based design outperforms the traditional VLE-based design. © 2011 Wessa et al.

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Analysis of covariance (ANCOVA) is a useful method of ‘error control’, i.e., it can reduce the size of the error variance in an experimental or observational study. An initial measure obtained before the experiment, which is closely related to the final measurement, is used to adjust the final measurements, thus reducing the error variance. When this method is used to reduce the error term, the X variable must not itself be affected by the experimental treatments, because part of the treatment effect would then also be removed. Hence, the method can only be safely used when X is measured before an experiment. A further limitation of the analysis is that only the linear effect of Y on X is being removed and it is possible that Y could be a curvilinear function of X. A question often raised is whether ANCOVA should be used routinely in experiments rather than a randomized blocks or split-plot design, which may also reduce the error variance. The answer to this question depends on the relative precision of the difference methods with reference to each scenario. Considerable judgment is often required to select the best experimental design and statistical help should be sought at an early stage of an investigation.

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Objective - To investigate whether artificial tears and cold compress alone or in combination provide a treatment benefit and whether they were as effective as or could enhance topical antiallergic medication. Design - Randomized, masked clinical trial. Participants - Eighteen subjects (mean age, 29.5±11.0 years) allergic to grass pollen. Intervention - Controlled exposure to grass pollen using an environmental chamber to stimulate an ocular allergic reaction followed by application of artificial tears (ATs), 5 minutes of cold compress (CC), ATs combined with CC, or no treatment applied at each separate visit in random order. A subset of 11 subjects also had epinastine hydrochloride (EH) applied alone and combined with CC in random order or instillation of a volume-matched saline control. Main Outcome Measures - Bulbar conjunctival hyperemia, ocular surface temperature, and ocular symptoms repeated before and every 10 minutes after treatment for 1 hour. Results - Bulbar conjunctival hyperemia and ocular symptoms decreased and temperature recovered to baseline faster with nonpharmaceutical treatments compared with no treatment (P?treatments (P?treatment effect of EH was enhanced by combining it with a CC (P?effect (P?>?0.05). At all measurement intervals, symptoms were reduced for both EH and EH combined with CC than CC or ATs alone or in combination (P?treatment showed a therapeutic effect on the signs and symptoms of allergic conjunctivitis. A CC enhanced the use of EH alone and was the only treatment to reduce symptoms to baseline within 1 hour of antigenic challenge. Signs of allergic conjunctivitis generally were reduced most by a combination of a CC in combination with ATs or EH.

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Objective To investigate whether artificial tears and cold compress alone or in combination provide a treatment benefit and whether they were as effective as or could enhance topical antiallergic medication. Design Randomized, masked clinical trial. Participants Eighteen subjects (mean age, 29.5±11.0 years) allergic to grass pollen. Intervention Controlled exposure to grass pollen using an environmental chamber to stimulate an ocular allergic reaction followed by application of artificial tears (ATs), 5 minutes of cold compress (CC), ATs combined with CC, or no treatment applied at each separate visit in random order. A subset of 11 subjects also had epinastine hydrochloride (EH) applied alone and combined with CC in random order or instillation of a volume-matched saline control. Main Outcome Measures Bulbar conjunctival hyperemia, ocular surface temperature, and ocular symptoms repeated before and every 10 minutes after treatment for 1 hour. Results Bulbar conjunctival hyperemia and ocular symptoms decreased and temperature recovered to baseline faster with nonpharmaceutical treatments compared with no treatment (P <0.05). Artificial tears combined with CC reduced hyperemia more than other treatments (P <0.05). The treatment effect of EH was enhanced by combining it with a CC (P <0.001). Cold compress combined with ATs or EH lowered the antigen-raised ocular surface temperature to less than the pre-exposure baseline. Artificial tear instillation alone or CC combined with ATs or EH significantly reduced the temperature (P <0.05). Cold compress combined with ATs or EH had a similar cooling effect (P > 0.05). At all measurement intervals, symptoms were reduced for both EH and EH combined with CC than CC or ATs alone or in combination (P <0.014). Conclusions After controlled exposure to grass pollen, CC and AT treatment showed a therapeutic effect on the signs and symptoms of allergic conjunctivitis. A CC enhanced the use of EH alone and was the only treatment to reduce symptoms to baseline within 1 hour of antigenic challenge. Signs of allergic conjunctivitis generally were reduced most by a combination of a CC in combination with ATs or EH. © 2014 by the American Academy of Ophthalmology.

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Auditory Training (AT) describes a regimen of varied listening exercises designed to improve an individual’s ability to perceive speech. The theory of AT is based on brain plasticity (the capacity of neurones in the central auditory system to alter their structure and function) in response to auditory stimulation. The practice of repeatedly listening to the speech sounds included in AT exercises is believed to drive the development of more efficient neuronal pathways, thereby improving auditory processing and speech discrimination. This critical review aims to assess whether auditory training can improve speech discrimination in adults with mild-moderate SNHL. The majority of patients attending Audiology services are adults with presbyacusis and it is therefore important to evaluate evidence of any treatment effect of AT in aural rehabilitation. Ideally this review would seek to appraise evidence of neurophysiological effects of AT so as to verify whether it does induce change in the CAS. However, due to the absence of such studies on this particular patient group, the outcome measure of speech discrimination, as a behavioural indicator of treatment effect is used instead. A review of available research was used to inform an argument for or against using AT in rehabilitative clinical practice. Six studies were identified and although the preliminary evidence indicates an improvement gained from a range of AT paradigms, the treatment effect size was modest and there remains a lack of large-sample RCTs. Future investigation into the efficacy of AT needs to employ neurophysiological studies using auditory evoked potentials in hearing-impaired adults in order to explore effects of AT on the CAS.

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The overall objective of this work was to compare the effect of pre-treatment and catalysts on the quality of liquid products from fast pyrolysis of biomass. This study investigated the upgrading of bio-oil in terms of its quality as a bio-fuel and/or source of chemicals. Bio-oil used directly as a biofuel for heat or power needs to be improved particularly in terms of temperature sensitivity, oxygen content, chemical instability, solid content, and heating values. Chemicals produced from bio-oil need to be able to meet product specifications for market acceptability. There were two main objectives in this research. The first was to examine the influence of pre-treatment of biomass on the fast pyrolysis process and liquid quality. The relationship between the method of pre-treatment of biomass feedstock to fast pyrolysis oil quality was studied. The thermal decomposition behaviour of untreated and pretreated feedstocks was studied by using a TGA (thermogravimetric analysis) and a Py-GC/MS (pyroprobe-gas chromatography/mass spectrometry). Laboratory scale reactors (100g/h, 300g/h, 1kg/h) were used to process untreated and pretreated feedstocks by fast pyrolysis. The second objective was to study the influence of numerous catalysts on fast pyrolysis liquids from wheat straw. The first step applied analytical pyrolysis (Py-GC/MS) to determine which catalysts had an effect on fast pyrolysis liquid, in order to select catalysts for further laboratory fast pyrolysis. The effect of activation, temperature, and biomass pre-treatment on catalysts were also investigated. Laboratory experiments were also conducted using the existing 300g/h fluidised bed reactor system with a secondary catalytic fixed bed reactor. The screening of catalysts showed that CoMo was a highly active catalyst, which particularly reduced the higher molecular weight products of fast pyrolysis. From these screening tests, CoMo catalyst was selected for larger scale laboratory experiments. With reference to the effect of pre-treatment work on fast pyrolysis process, a significant effect occurred on the thermal decomposition of biomass, as well as the pyrolysis products composition, and the proportion of key components in bio-oil. Torrefaction proved to have a mild influence on pyrolysis products, when compared to aquathermolysis and steam pre-treatment.

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The effect of thermochemical treatment namely carburising on the fatigue behaviour of one carbon and two alloy steels has been studied in rotating and unidirectional bending. The effect of carbon profile on the unidirect¬ional bending fatigue strength of 63SA14 was assessed, and it was found that single stage carburising with a surface carbon content of 0.8% has resulted in a higher fatigue strength than other types of carbon profiles. Residual stresses and other metallurgical variables arising from different carbon profiles, were also considered. The highest compressive stresses h~e resulted from boost-diffuse-carburising. On the other hand surface decarburisation was associated with tensile residual stresses and a reduced fatigue strength. Retained austenite was found to be detrimental in unidirectional bending fatigue; however its presence in carburised 83SAIS did not seem to influence the rotating bending fatigue strength. Carbide particles in globular and/or intergranular form were detrimental to compressive residual stresses; the unidirectional bending fatigue strength is markedly lowered. The highest fatigue strength was accomplished by vacuum carburising. The absence of internal oxidation was the key factor in the increased fatigue strength; the presence of uniformly distributed fine carbide particles did not upset the superior fatigue strength of vacuum carburised pieces. The effect of mean stress on the fatigue strength of carburised 63SA14 was studied. Increasing the mean stress as would be expected resulted in a decreased fatigue strength. Carburisation showed its advantages at low mean stress, but at high mean stress it offers little advantage over the uncarburised hardened conditions. Notch effect was also studied in unidirectional bending of carburised 080MlS. The general trend showed that the fatigue strength decreases with increasing the stress concentration factor. But different carburising conditions have different effect on notch sensitivity.

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Pulsed Nd:YAG has been adopted successfully in welding process of thin (0.7 mm) Ti6Al4V. Laser welding of such thin sheet requires a small focal spot, good laser beam quality and fast travel speed, since too much heat generation can cause distortion for thin sheet weld. The microstructures of Ti6Al4V were complex and strongly affected the mechanical properties. These structures include: a´ martensite, metastable ß, Widmanstätten, bimodal, lamellar and equiaxed microstructure. Bimodal and Widmanstätten structures exhibit a good-balance between strength and ductility. The microstructure of pulsed Nd:YAG welded Ti6Al4V was primarily a´ martensite, which showed the lowest ductility but not significantly high strength. A heat treatment at 950 followed by furnace cooling can transform the microstructure in the weld from a´ martensite structure into Widmanstätten structure.

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Coalition loyalty programs are on the rise, yet few studies investigate the impact of service failures in such programs. Using data from a retail context, the authors show that a program partner deemed responsible for a service failure suffers negative customer responses. However, customers' perceptions of the benefits of the coalition loyalty program buffer these consequences. Perhaps most importantly, when customers perceive the program's special treatment benefits as low, direct and indirect spillover effects occur, such that a service failure by one program partner has a negative effect on customer loyalty toward the program itself. © 2013 New York University.