131 research outputs found
An overview of using small punch testing for mechanical characterization of MCrAlY bond coats
Considerable work has been carried out on overlay bond coats in the past several decades because of its excellent oxidation resistance and good adhesion between the top coat and superalloy substrate in the thermal barrier coating systems. Previous studies mainly focus on oxidation and diffusion behavior of these coatings. However, the mechanical behavior and the dominant fracture and deformation mechanisms of the overlay bond coats at different temperatures are still under investigation. Direct comparison between individual studies has not yet been achieved due to the fragmentary data on deposition processes, microstructure and, more apparently, the difficulty in accurately measuring the mechanical properties of thin coatings. One of the miniaturized specimen testing methods, small punch testing, appears to have the potential to provide such mechanical property measurements for thin coatings. The purpose of this paper is to give an overview of using small punch testing to evaluate material properties and to summarize the available mechanical properties that include the ductile-to-brittle transition and creep of MCrAlY bond coat alloys, in an attempt to understand the mechanical behavior of MCrAlY coatings over a broad temperature range
Evidence for direct CP violation in B-0 -> K+pi(-) decays
We report evidence for direct CP violation in the decay B-0-->K(+)pi(-) with 253 fb(-1) of data collected with the Belle detector at the KEKB e(+)e(-) collider. Using 275x10(6) B(B) over bar pairs we observe a B-->K(+/-)pi(-/+) signal with 2140+/-53 events. The measured CP violating asymmetry is A(CP)(K(+)pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to a significance of 3.9sigma including systematics. We also search for CP violation in the decays B+-->K(+)pi(0) and B+-->pi(+)pi(0). The measured CP violating asymmetries are A(CP)(K(+)pi(0))=0.04+/-0.05(stat)+/-0.02(syst) and A(CP)(pi(+)pi(0))=-0.02+/-0.10(stat)+/-0.01(syst), corresponding to the intervals -0.05< A(CP)(K(+)pi(0))<0.13 and -0.18< A(CP)(pi(+)pi(0))<0.14 at 90% confidence level
Evaluation of Protective Efficacy of Respiratory Syncytial Virus Vaccine against A and B Subgroup Human Isolates in Korea
Human respiratory syncytial virus (HRSV) is a significant cause of upper and lower respiratory tract illness mainly in infants and young children worldwide. HRSV is divided into two subgroups, HRSV-A and HRSV-B, based on sequence variation within the G gene. Despite its importance as a respiratory pathogen, there is currently no safe and effective vaccine for HRSV. In this study, we have detected and identified the HRSV by RT-PCR from nasopharyngeal aspirates of Korean pediatric patients. Interestingly, all HRSV-B isolates exhibited unique deletion of 6 nucleotides and duplication of 60 nucleotides in the G gene. We successfully amplified two isolates (‘KR/A/09-8’ belonging to HRSV-A and ‘KR/B/10-12’ to HRSV-B) on large-scale, and evaluated the cross-protective efficacy of our recombinant adenovirus-based HRSV vaccine candidate, rAd/3xG, by challenging the immunized mice with these isolates. The single intranasal immunization with rAd/3xG protected the mice completely from KR/A/09-8 infection and partially from KR/B/10-12 infection. Our study contributes to the understanding of the genetic characteristics and distribution of subgroups in the seasonal HRSV epidemics in Korea and, for the first time, to the evaluation of the cross-protective efficacy of RSV vaccine against HRSV-A and -B field-isolates
The impact of radiotherapy in the treatment of desmoid tumours. An international survey of 110 patients. A study of the Rare Cancer Network
PURPOSE: A multi-centre study to assess the value of combined surgical resection and radiotherapy for the treatment of desmoid tumours. PATIENTS AND METHODS: One hundred and ten patients from several European countries qualified for this study. Pathology slides of all patients were reviewed by an independent pathologist. Sixty-eight patients received post-operative radiotherapy and 42 surgery only. Median follow-up was 6 years (1 to 44). The progression-free survival time (PFS) and prognostic factors were analysed. RESULTS: The combined treatment with radiotherapy showed a significantly longer progression-free survival than surgical resection alone (p smaller than 0.001). Extremities could be preserved in all patients treated with combined surgery and radiotherapy for tumours located in the limb, whereas amputation was necessary for 23% of patients treated with surgery alone. A comparison of PFS for tumour locations proved the abdominal wall to be a positive prognostic factor and a localization in the extremities to be a negative prognostic factor. Additional irradiation, a fraction size larger than or equal to 2 Gy and a total dose larger than 50 Gy to the tumour were found to be positive prognostic factors with a significantly lower risk for a recurrence in the univariate analysis. This analysis revealed radiotherapy at recurrence as a significantly worse prognostic factor compared with adjuvant radiotherapy. The addition of radiotherapy to the treatment concept was a positive prognostic factor in the multivariate analysis. CONCLUSION: Postoperative radiotherapy significantly improved the PFS compared to surgery alone. Therefore it should always be considered after a non-radical tumour resection and should be given preferably in an adjuvant setting. It is effective in limb preservation and for preserving the function of joints in situations where surgery alone would result in deficits, which is especially important in young patients
Granular Assembly of α-Synuclein Leading to the Accelerated Amyloid Fibril Formation with Shear Stress
α-Synuclein participates in the Lewy body formation of Parkinson's disease. Elucidation of the underlying molecular mechanism of the amyloid fibril formation is crucial not only to develop a controlling strategy toward the disease, but also to apply the protein fibrils for future biotechnology. Discernable homogeneous granules of α-synuclein composed of approximately 11 monomers in average were isolated in the middle of a lag phase during the in vitro fibrillation process. They were demonstrated to experience almost instantaneous fibrillation during a single 12-min centrifugal membrane-filtration at 14,000×g. The granular assembly leading to the drastically accelerated fibril formation was demonstrated to be a result of the physical influence of shear force imposed on the preformed granular structures by either centrifugal filtration or rheometer. Structural rearrangement of the preformed oligomomeric structures is attributable for the suprastructure formation in which the granules act as a growing unit for the fibril formation. To parallel the prevailing notion of nucleation-dependent amyloidosis, we propose a double-concerted fibrillation model as one of the mechanisms to explain the in vitro fibrillation of α-synuclein, in which two consecutive concerted associations of monomers and subsequent oligomeric granular species are responsible for the eventual amyloid fibril formation
Indications for Detection, Completion, and Retention Rates of Small Bowel Capsule Endoscopy Based on the 10-Year Data from the Korean Capsule Endoscopy Registry.
BACKGROUND/AIMS: Capsule endoscopy (CE) is widely used. However, CE has limitations including incomplete examination, inadequate bowel preparation, and retention. The aim of this study was to estimate the indications for and detection, completion, and retention rates of small intestine CE based on the 10-year data from the Korean Capsule Endoscopy Registry.
METHODS: Twenty-four hospitals participated in this study. Clinical information, such as reasons for CE, method and quality of bowel preparation, and incomplete examination and capsule retention rates, was collected and analyzed.
RESULTS: A total of 2,914 CEs were registered. The most common reason for CE was obscure gastrointestinal bleeding (59%). Significant lesions were detected in 66% of cases. Positive CE diagnosis occurred in 63% of cases. The preparation method did not significantly affect the quality of bowel preparation for CE. The overall incomplete rate was 33%, and was high in the elderly and those with poor bowel preparation. Capsule retention was 3% and high in patients with small bowel tumors and Crohn's disease and in children under 10 years of age.
CONCLUSIONS: CE is a valuable technique; while the overall detection rate is high, incompletion and retention rates are also relatively high. CE should be carefully considered in the elderly and children less than 10 years of age, as well as in patients with small bowel tumors and Crohn's disease
Short rare hTERT-VNTR2-2nd alleles are associated with prostate cancer susceptibility and influence gene expression
Long-Term Outcomes of NSAID-Induced Small Intestinal Injury Assessed by Capsule Endoscopy in Korea: A Nationwide Multicenter Retrospective Study.
BACKGROUND/AIMS: We evaluated the long-term outcome and clinical course of patients of nonsteroidal anti-inflammatory drug (NSAID)-induced small intestinal injury by performing capsule endoscopy (CE).
METHODS: A multicenter retrospective study was conducted using data collected from the CE nationwide database registry, which has been established since 2002.
RESULTS: A total of 140 patients (87 males; mean age, 60.6±14.8 years) from the CE nationwide database registry (n=2,885) were diagnosed with NSAID-induced small intestinal injury and enrolled in our study. Forty-nine patients (35.0%) presented with a history of aspirin use and an additional 49 (35.0%) were taking NSAIDs without aspirin. The most prominent findings after performing CE were multiple ulcerations (n=82, 58.6%) and erosions or aphthae (n=32, 22.9%). During the follow-up period (mean, 15.9±19.0 months; range, 0 to 106 months), NSAID-induced small intestinal injury only recurred in six patients (4.3%). Older age and hypertension were positive predictive factors for recurrence.
CONCLUSIONS: These results suggest that the recurrence of NSAID-induced small bowel injury was not frequent in the presence of conservative treatment. Therefore, the initial diagnosis using CE and the medication history are important
Diagnostic Yield and Clinical Impact of Video Capsule Endoscopy in Patients with Chronic Diarrhea: A Korean Multicenter CAPENTRY Study
Background/Aims: In some cases, chronic diarrhea is unexplained, and small bowel disorders may be one of the causes. The aim of this study was to assess the diagnostic yield and clinical impact of video capsule endoscopy (VCE) in patients with chronic diarrhea.
Methods: We retrospectively analyzed records from October 2002 to August 2013 in the VCE nationwide database registry (n=2,964). Ninety-one patients from 15 medical centers (60 males and 31 females: mean age, 47+/-19 years) were evaluated for VCE as a result of chronic diarrhea.
Results: The duration of chronic diarrhea was 8.3+/-14.7 months. The positive diagnostic yield of VCE was 42.9% (39/91). However, 15.4% (14/91) exhibited an inconsistent result, and 41.8% (38/91) were negative. Abnormal findings consistent with chronic diarrhea included erosions/aphthous ulcers (19.8%), ulcers (17.6%), mucosal erythema (3.3%), edema (1.1%), and luminal narrowing (1.1%). The most common diagnoses were functional diarrhea associated with irritable bowel syndrome in 37 patients (40.7%) and Crohn's disease in 18 patients (19.8%). After VCE examination, the diagnosis was changed in 34.1% of the patients (31/91). Hematochezia (odds ratio [OR], 8.802: 95% confidence interval [CI], 2.126 to 36.441) and hypoalbuminemia (OR, 4.811: 95% CI, 1.241 to 18.655) are predictive factors of a positive diagnostic yield.
Conclusions: VCE had a favorable diagnostic yield and clinical impact on the management of patients with chronic diarrhea
Combining motivational and volitional approaches to reducing excessive alcohol consumption in pre-drinkers: A theory-based intervention protocol
Background: Pre-drinking refers to the consumption of alcohol at home or a private residence prior to attending a subsequent social event. We present the study protocol of an online theory-based intervention to reduce pre-drinking and related harm in pre-drinking undergraduates, using behavior change techniques targeting the motivational and volitional phases of behaviour. Design: A fully randomized 2 (autonomy support: present vs. absent) x 2 (implementation intention: present vs. absent) between-participants design will be used to ascertain the effectiveness of the intervention in reducing pre-drinking alcohol consumption and alcohol-related harm. Participants will complete a range of theory-based measures prior to being allocated to one of the four experimental conditions. Four weeks later, participants will complete a follow-up questionnaire comprised of theoretical and behavioral measures. Analyses: The main and interactive effects of the intervention components in reducing our primary dependent variables, namely, pre-drinking alcohol consumption and alcohol-related harm at four-week follow-up will be tested. Baseline alcohol consumption and demographic information will be included in the analysis as covariates. Discussion: This online intervention is the first to be developed to reduce pre-drinking alcohol consumption, a behaviour linked to increased risk of alcohol-related harm. The intervention targets motivational and volitional components of the behaviour change process and is therefore likely to lead to greater reductions in pre-drinking alcohol consumption and experience of alcohol-related harm compared to either approach in isolation. If successful, the intervention can be implemented across various contexts and in populations where pre-drinking is prevalent. © 2016 Caudwell et al
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