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Life Improvement (life + improvement)

Distribution by Scientific Domains

Medical Sciences	63%
Polymers and Materials Science	36%

Kinds of Life Improvement

fatigue life improvement

Selected Abstracts

Warm Laser Shock Peening Driven Nanostructures and Their Effects on Fatigue Performance in Aluminum Alloy 6160,

ADVANCED ENGINEERING MATERIALS, Issue 4 2010
Chang Ye
Warm laser shock peening is an innovative manufacturing process that integrates laser shock peening and dynamic aging to improve materials' fatigue performance. Compared to traditional laser shock peening (LSP), warm laser shock peening (WLSP) , i.e., LSP at elevated temperatures , provides better performance in many aspects. WLSP can induce nanoscale precipitation and high density dislocation arrangement, resulting in higher surface strength and lower surface roughness than LSP, which are both beneficial for fatigue life improvement. Due to pinning of the dislocation structure by nanoscale precipitates , so-called dislocation pinning effects , the relaxation of residual stress and surfaces dislocation arrangement is significantly reduced. In this study, AA6061 alloy is used to evaluate the WLSP process. It is found that the fatigue life improvements after WLSP are not only caused by large compressive residual stress and high density dislocations but also by the higher stability of the residual stresses and surface strength during cyclic loading. [source]

Description of fatigue damage in carbon black filled natural rubber

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2008
J.-B. LE CAM
ABSTRACT The present paper describes macroscopic fatigue damage in carbon black-filled natural rubber (CB-NR) under uniaxial loading conditions. Uniaxial tension-compression, fully relaxing uniaxial tension and non-relaxing uniaxial tension loading conditions were applied until sample failure. Results, summarized in a Haigh-like diagram, show that only one type of fatigue damage is observed for uniaxial tension-compression and fully relaxing uniaxial tension loading conditions, and that several different types of fatigue damage take place in non-relaxing uniaxial tension loading conditions. The different damage types observed under non-relaxing uniaxial tension, loading conditions are closely related to the improvement of rubber fatigue life. Therefore, as fatigue life improvement is classically supposed to be due to strain-induced crystallization (SIC), a similar conclusion can be drawn for the occurrence of different types of fatigue damage. [source]

The effect of laser power density on the fatigue life of laser-shock-peened 7050 aluminium alloy

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 11 2007
Q. LIU
ABSTRACT Laser shock peening (LSP) is an innovative surface treatment method that can result in significant improvement in the fatigue life of many metallic components. The process produces very little or no surface profile modification while producing a considerably deeper compressive residual stress layer than traditional shot peening operations. The work discussed here was designed to: (a) quantify the fatigue life improvement achieved by LSP in a typical high strength aircraft aluminium alloy and (b) identify any technological risks associated with its use. It is shown that when LSP conditions are optimal for the material and specimen configuration, a ,three to four times increase in fatigue life over the as-machined specimens could be achieved for a representative fighter aircraft loading spectrum when applied at a representative load level. However, if the process parameters are not optimal for the material investigated here, fatigue lives of LSP treated specimens may be reduced instead of increased due to the occurrence of internal cracking. This paper details the effect of laser power density on fatigue life of 7050-T7451 aluminium alloy by experimental and numerical analysis. [source]

Quality of life in acute and maintenance treatment of non-erosive and mild erosive gastro-oesophageal reflux disease

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2005
F. PACE
Summary Background:, Quality of life has been assessed in a large, multicentre randomized, open label study. Aim:, To evaluate the economic and clinical consequences of two different maintenance treatment modalities, administered to 6017 gastro-oesophageal reflux disease patients at 451 gastroenterological centres in Italy. Methods:, Adult gastro-oesophageal reflux disease patients received, at enrolment, an acute treatment of esomeprazole 40 mg/day for 4 weeks and, if successfully treated, were randomized into two maintenance treatment strategies: esomeprazole 20 mg/day or esomeprazole on demand for 6 months. A baseline endoscopy allowed the exclusion of grade II,IV oesophagitis according to Savary,Miller's classification. Burden of gastro-oesophageal reflux disease was measured at baseline by the generic questionnaire Short-Form 36 and by a disease specific instrument, quality of life in reflux and dyspepsia (QOLRAD), also administered at start and conclusion of maintenance period. Investigators were required to collect patient judgement about the degree of satisfaction with treatment effect on heartburn, with a 7-point scale. Results:, A comparison between Short-Form 36 scores and the normative source of the Italian general population suggested that symptomatic gastro-oesophageal reflux disease patients experience a worse quality of life than the general population. At the end of the 4-week treatment with esomeprazole 40 mg all (QOLRAD) dimensions showed a statistically significant (P < 0.0001) and clinically meaningful improvement. Satisfaction level towards treatment was reported high in the total enrolled population after acute treatment with esomeprazole 40 mg/day (96.2% satisfied and 64.4% very satisfied). A statistically significant difference in (QOLRAD) scores was registered at the end of maintenance phase in favour of the continuous regimen, nevertheless the size of this difference was very small in all dimensions; similarly, the proportion of patients very satisfied was slightly higher in the continuous treatment arm (64.5%) than in the on-demand arm (59.7%). Conclusions:, Gastro-oesophageal reflux disease can significantly impair health-related quality of life and esomeprazole therapy allows immediate relief in the acute phase of the disease. Quality of life improvement was maintained during the 6-month follow-up with a slight difference in term of quality of life in reflux and dyspepsia scores and patients' satisfaction in favour of the continuous treatment strategy. [source]

The effect of spinal cord stimulation in patients with chronic reflex sympathetic dystrophy: Two years' follow-up of the randomized controlled trial

ANNALS OF NEUROLOGY, Issue 1 2004
Marius A. Kemler MD
Chronic reflex sympathetic dystrophy is a painful, disabling disorder for which no treatment with proven effect is available. We performed a randomized trial in a 2 to 1 ratio of patients, in which 36 patients were treated with spinal cord stimulation and physical therapy (SCS+PT), and 18 patients received solely PT. Twenty-four SCS+PT patients were given a permanent spinal cord stimulation system after successful test stimulation; the remaining 12 patients received no permanent system. We assessed pain intensity, global perceived effect, functional status, and health-related quality of life. Patients were examined before randomization, before implantation, and also at 1, 3, 6, 12, and 24 months thereafter. At 2 years, three patients were excluded from the analysis. The intention-to-treat analysis showed improvements in the SCS+PT group concerning pain intensity (,2.1 vs 0.0cm; p < 0.001) and global perceived effect (43% vs 6% "much improved"; p = 0.001). There was no clinically important improvement of functional status. Health-related quality of life improved only in the group receiving spinal cord stimulation. After careful selection and successful test stimulation, spinal cord stimulation results in a long-term pain reduction and health-related quality of life improvement in chronic reflex sympathetic dystrophy. [source]

Quality of life assessment after non-laser endonasal dacryocystorhinostomy

CLINICAL OTOLARYNGOLOGY, Issue 5 2006
A. Ho
Objective:, There has been a lack of patient-centred evidence in the Otolaryngology literature, that non-laser endonasal dacryocystorhinostomy improves the quality of life of patients. Many studies demonstrate successful outcomes based on non-validated subjective patient reporting. The aim of this survey was to evaluate the impact of non-laser endonasal dacryocystorhinostomy on the quality of life of patients using a validated questionnaire, the Glasgow Benefit Inventory (GBI). Design:, Prospective non-randomised case series. Setting:, Secondary otorhinolaryngology,ophthalmology centre, single centre. Participants:, Sixty-five consecutive patients undergoing non-laser endonasal dacryocystorhinostomy were asked to complete a questionnaire at their follow-up clinic appointment. All patients had a minimum of 9 months follow-up. Main outcome measures:, A consultant ophthalmologist reviewed each patient six months after surgery and recorded the outcomes as ,cure', ,better', ,no change' or ,worse'. We defined ,success' as cured or better. ,Failure' suggests no improvement or worsening epiphora. The validated 18-item GBI was used. Results:, Fully completed questionnaires were received from 55 patients. Mean total GBI scores were +34 for successful non-laser endonasal dacryocystorhinostomy and ,19 for failed non-laser endonasal dacryocystorhinostomy (Mann,Whitney z = 3.8, P < 0.001). Conclusion:, Successful non-laser endonasal dacryocystorhinostomy does confer significant quality of life improvement. [source]

Warm Laser Shock Peening Driven Nanostructures and Their Effects on Fatigue Performance in Aluminum Alloy 6160,

Service Use and Costs of Support 12 Years after Leaving Hospital

JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 4 2006
Angela Hallam
Background, There have been major changes in the provision and organization of services for people with intellectual disabilities in England over the last 30 years, particularly deinstitutionalization and the development of the mixed economy of care. The experiences of the people who participated in the Care in the Community Demonstration Programme in the mid-1980s provide evidence of the immediate and longer-term effects of the reprovision policy. Methods, Cross-sectional and longitudinal evidence was gathered on service use and costs for over 250 people 12 years after they left long-stay hospitals for community living arrangements. Comparisons were made with the situation in hospital, and 1 and 5 years after leaving. Relationships between costs after 12 years and individual characteristics assessed before people left hospital were explored. Results, Community care at the 12-year follow-up remained more expensive than hospital-based support, although the average cost was lower than at either of the 1- or 5-year community follow-up points. Service users were living in a wide variety of accommodation settings. Management responsibility fell on National Health Service (NHS) trusts, local authorities, voluntary agencies, or to private organizations or individuals. After standardizing for users' skills and abilities, costs in minimum support accommodation were significantly lower than those in residential and nursing homes, costs in staffed group homes significantly higher, and costs in hostels slightly lower. When looking at differences between individuals, no relationship was found between costs and outcomes although, overall, people were better off in the community than they had been when in hospital. Conclusions, Reprovision planning for hospital and other institutional modes of care requires major and long-term commitment of resources. Quality of life improvements can be achieved at a cost little different in the long-run from that for hospital care. The link between needs and costs (reflecting the services intended to meet those needs) would be made stronger through the individualization of care. [source]

Clinical trial: the effects of the proton pump inhibitor dexlansoprazole MR on daytime and nighttime heartburn in patients with non-erosive reflux disease

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2009
R. FASS
Summary Background, The proportion of patients who respond to proton pump inhibitor (PPI) therapy is about 20% lower in those with non-erosive reflux disease (NERD) than in those with erosive oesophagitis. Aim, To assess efficacy and safety of dexlansoprazole MR, a PPI using Dual Delayed Release technology, in NERD patients. Methods, In this 4-week, double-blind, placebo-controlled study, 947 NERD patients randomly received dexlansoprazole MR 30 mg, 60 mg or placebo once daily (QD). The percentages of 24-h heartburn-free days (primary) and nights without heartburn (secondary) were assessed from patients' daily diaries. Investigators also assessed symptoms. Patients completed validated quality of life and symptom severity questionnaires. Results, Dexlansoprazole MR provided significantly greater median percentages of 24-h heartburn-free days (54.9% and 50.0% for the 30- and 60-mg doses vs. 17.5% for placebo, P < 0.00001) and nights without heartburn (80.8% and 76.9% vs. 51.7%, P < 0.00001 vs. placebo). Dexlansoprazole MR also reduced symptom severity. Quality of life improvements in patients receiving dexlansoprazole MR were consistent with clinical efficacy endpoints. Percentages of patients experiencing treatment-emergent adverse events were similar among groups. Conclusions, Dexlansoprazole MR 30 and 60 mg were superior to placebo in providing 24-h heartburn-free days and nights in NERD patients. Treatment was well tolerated. [source]

Evaluation of the meaningfulness of health-related quality of life improvements as assessed by the SF-36 and the EQ-5D VAS in patients with active Crohn's disease

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2009
G. COTEUR
Summary Background, Crohn's disease (CD) is a chronic inflammatory illness characterized by episodic abdominal pain, diarrhoea, fever, bleeding and obstruction. While the Crohn's Disease Activity Index (CDAI) remains the most commonly accepted measure for assessing the disease status in clinical trials, patient-reported outcome (PRO) instruments are being utilized more frequently to provide information about health-related quality of life (HRQOL). To facilitate interpretation of results, it is common to identify a meaningful unit of PRO score change, such as a minimal clinically important difference (MCID). Aim, To define and apply MCID estimates for the SF-36 and EuroQol-5D visual analogue scale (EQ-5D VAS) for use in CD treatment evaluation. Methods, Data from two phase III randomized controlled trials of certolizumab pegol were utilized. MCID estimates were computed from one trial using anchor-based and distribution-based methods. These estimates were applied to data from the other trial. Results, SF-36 PCS and MCS MCID estimates ranged from 1.6 to 7.0 and 2.3 to 8.7 respectively, depending on approach. EQ-5D VAS MCID estimates ranged from 4.2 to 14.8. Conclusions, For the first time, the MCID values provided interpretation guidelines for PRO results in CD. This research demonstrates that patients treated with certolizumab pegol benefit from meaningful and sustained HRQOL improvements. [source]

Acupuncture in patients with osteoarthritis of the knee or hip: A randomized, controlled trial with an additional nonrandomized arm

ARTHRITIS & RHEUMATISM, Issue 11 2006
Claudia M. Witt
Objective To investigate the effectiveness of acupuncture in addition to routine care, compared with routine care alone, in the treatment of patients with chronic pain due to osteoarthritis (OA) of the knee or hip. Methods In a randomized, controlled trial, patients with chronic pain due to OA of the knee or hip were randomly allocated to undergo up to 15 sessions of acupuncture in a 3-month period or to a control group receiving no acupuncture. Another group of patients who did not consent to randomization underwent acupuncture treatment. All patients were allowed to receive usual medical care in addition to the study treatment. Clinical OA severity (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) and health-related quality of life (Short Form 36) were assessed at baseline and after 3 months and 6 months. Results Of 3,633 patients (mean ± SD age 61.8 ± 10.8 years; 61% female), 357 were randomized to the acupuncture group and 355 to the control group, and 2,921 were included in the nonrandomized acupuncture group. At 3 months, the WOMAC had improved by a mean ± SEM of 17.6 ± 1.0 in the acupuncture group and 0.9 ± 1.0 in the control group (3-month scores 30.5 ± 1.0 and 47.3 ± 1.0, respectively [difference in improvement 16.7 ± 1.4; P < 0.001]). Similarly, quality of life improvements were more pronounced in the acupuncture group versus the control group (P < 0.001). Treatment success was maintained through 6 months. The changes in outcome in nonrandomized patients were comparable with those in randomized patients who received acupuncture. Conclusion These results indicate that acupuncture plus routine care is associated with marked clinical improvement in patients with chronic OA,associated pain of the knee or hip. [source]