3,322 research outputs found
Cure monitoring of composites with embedded piezoelectric sensors
Manufacturing of carbon fiber reinforce polymers (CFRPs) presents challenges because of uncertainty in the exact conditions of cure in the material, especially in a complex structure, and this effects the quality of the finished product. This work evaluates the use of piezoelectric sensors embedded into CFRP layups before curing to monitor the composite material during the cure cycle. These sensors were used to propagate ultrasonic waves through the structure at different stages during cure. By examining features of the changing ultrasonic signal, the corresponding changes in material properties of the composite can be observed
Information System Development Team Collaboration Antecedents
Despite information system development companies have invested substantial resources to support the success of information system development (ISD) projects, the failure rate is still high. Extant studies indicated that the constant changes from socio-technical environments are the main causes of the low success rate. This study argues that team collaboration is a key factor to effectively cope with unexpected disruptions that would have negative effect on overall software product success. This study proposes a research model exploring factors that influence the development of team collaboration. These factors include the team commitment, transactive memory systems (TMS), and collective mind. In addition, the study suggests that the collective mind has an intermediate effect on the team commitment, TMS, and team collaboration. This study takes the information development teams of various companies in Taiwan as its subjects
Modeling of failure and response to laminated composites subjected to in-plane loads
An analytical model was developed for predicting the response of laminated composites with or without a cutout and subjected to in-plane tensile and shear loads. Material damage resulting from the loads in terms of matrix cracking, fiber-matrix shearing, and fiber breakage was considered in the model. Delamination, an out-of-plane failure mode, was excluded from the model
Epidemiology of gout in the United Kingdom and Taiwan
Background: Gout is the most common inflammatory arthritis worldwide. The hallmarks of initial gout presentation are acute pain, swelling, erythema and tenderness in peripheral joints but eventually unremitting arthritis, joint deformity and tophus deposition may develop with long-standing hyperuricaemia. Patients with gout suffer not only arthritis but also cardiovascular, renal, metabolic and other comorbidities. Since gout is the consequence of chronic hyperuricaemia, urate-lowering treatments (ULT) helps prevent the formation of urate crystals and promote dissolution of existing crystals.
Methods: This thesis contained results from a series of observational studies relating to gout. The data sources included the Clinical Practice Research Data-link in the UK and the National Health Insurance Database in Taiwan, both of which are representative of the general population in these two countries. Six different analyses were carried out: (1) epidemiology of gout in the UK (chapter 3); (2) epidemiology of gout in Taiwan (chapter 4); (3) Nature history of gout following diagnosis in the UK (chapter 5); (4) familial aggregation and heritability of gout in Taiwan (chapter 6); (5) risk of comorbidities occurring before gout diagnosis (chapter 7) and (6) Effects of allopurinol on all-cause mortality (chapter 8).
Results: This study estimated that the prevalence of gout was 2.49% in the UK in 2012 and 6.24% in Taiwan. Incidence of gout was also higher in Taiwan (3.47 per 1,000 person years in 2010) than in the UK (1.77 per 1,000 person years in 2012). The prevalence and incidence were increasing in the UK in the past decade, however, both of which remained stable in the period 2005-2010 in Taiwan. Compared with the general population, individuals with a family history of gout had a two-fold increased risk of the disease. The relative contributions of heritability, shared and non-shared environmental factors to explain phenotypic variance of gout were 35.1%, 28.1% and 36.8% in men and 17.0%, 18.5% and 64.5% in women, respectively. Patients with gout were already at higher risk of multiple comorbidities at diagnosis, furthermore, gout was associated with higher all-cause mortality. In both countries, the management of gout remains poor. Most gout patients were eligible for ULT at diagnosis or shortly after. Allopurinol, the most commonly prescribed ULT in primary care in the UK, exerted a neutral effect on all-cause mortality, which reassures the safety of the drug in terms of all-cause mortality.
Conclusions: Gout is the most common inflammatory arthritis affecting one in 40 people in the UK and one in 16 people in Taiwan. It is influenced by both environmental and genetic factors. Both incidence and prevalence keep rising in the UK whilst they remain comparatively stable in Taiwan. The management in the UK remains poor. Primary care physicians should be encouraged to screen for possible existing comorbidities at diagnosis. Most patients are eligible for ULT at diagnosis or shortly after diagnosis, and given the many benefits of ULT for gout patients, early discussion of ULT with patients seems reasonable practice. Allopurinol is not associated with heightened mortality which should reassure practitioners who avoid ULT for fear of serious adverse events
Design of Composite Laminates Containing Pin Loaded Holes
Methods are presented for sizing composite laminates containing one, two, or several pin loaded holes, the holes being arranged either in a single row or in two parallel rows. It is shown how the design parameters (number of holes, hole diameter, hole positions) can be found, which result in the maximum failure load and in the max imum failure load per unit weight.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68243/2/10.1177_002199838401800306.pd
Epidemiology of gout in the United Kingdom and Taiwan
Background: Gout is the most common inflammatory arthritis worldwide. The hallmarks of initial gout presentation are acute pain, swelling, erythema and tenderness in peripheral joints but eventually unremitting arthritis, joint deformity and tophus deposition may develop with long-standing hyperuricaemia. Patients with gout suffer not only arthritis but also cardiovascular, renal, metabolic and other comorbidities. Since gout is the consequence of chronic hyperuricaemia, urate-lowering treatments (ULT) helps prevent the formation of urate crystals and promote dissolution of existing crystals.
Methods: This thesis contained results from a series of observational studies relating to gout. The data sources included the Clinical Practice Research Data-link in the UK and the National Health Insurance Database in Taiwan, both of which are representative of the general population in these two countries. Six different analyses were carried out: (1) epidemiology of gout in the UK (chapter 3); (2) epidemiology of gout in Taiwan (chapter 4); (3) Nature history of gout following diagnosis in the UK (chapter 5); (4) familial aggregation and heritability of gout in Taiwan (chapter 6); (5) risk of comorbidities occurring before gout diagnosis (chapter 7) and (6) Effects of allopurinol on all-cause mortality (chapter 8).
Results: This study estimated that the prevalence of gout was 2.49% in the UK in 2012 and 6.24% in Taiwan. Incidence of gout was also higher in Taiwan (3.47 per 1,000 person years in 2010) than in the UK (1.77 per 1,000 person years in 2012). The prevalence and incidence were increasing in the UK in the past decade, however, both of which remained stable in the period 2005-2010 in Taiwan. Compared with the general population, individuals with a family history of gout had a two-fold increased risk of the disease. The relative contributions of heritability, shared and non-shared environmental factors to explain phenotypic variance of gout were 35.1%, 28.1% and 36.8% in men and 17.0%, 18.5% and 64.5% in women, respectively. Patients with gout were already at higher risk of multiple comorbidities at diagnosis, furthermore, gout was associated with higher all-cause mortality. In both countries, the management of gout remains poor. Most gout patients were eligible for ULT at diagnosis or shortly after. Allopurinol, the most commonly prescribed ULT in primary care in the UK, exerted a neutral effect on all-cause mortality, which reassures the safety of the drug in terms of all-cause mortality.
Conclusions: Gout is the most common inflammatory arthritis affecting one in 40 people in the UK and one in 16 people in Taiwan. It is influenced by both environmental and genetic factors. Both incidence and prevalence keep rising in the UK whilst they remain comparatively stable in Taiwan. The management in the UK remains poor. Primary care physicians should be encouraged to screen for possible existing comorbidities at diagnosis. Most patients are eligible for ULT at diagnosis or shortly after diagnosis, and given the many benefits of ULT for gout patients, early discussion of ULT with patients seems reasonable practice. Allopurinol is not associated with heightened mortality which should reassure practitioners who avoid ULT for fear of serious adverse events
Different Implications of Paternal and Maternal Atopy for Perinatal IgE Production and Asthma Development
Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma
Effect of allopurinol on all-cause mortality in adults with incident gout: propensity score–matched landmark analysis
Objective: To examine the association between allopurinol use and all-cause mortality for patients with incident gout.
Methods: We compared all-cause mortality in incident gout patients who received allopurinol for at least 6 months within the exposure window (1 year or 3 years) with those who did not, using the UK Clinical Practice Research Data-link. Landmark analysis was used to account for immortal time bias and propensity score matching was used to control for potential effects of known confounders.
Results: Of 23 332 incident gout patients identified, the propensity score–matched cohorts contained 1016 patients exposed to allopurinol on the date 1 year from diagnosis (landmark date) and 1016 allopurinol non-users. Over a median follow-up period of 10 years after the landmark date, there were 437 allopurinol users and 443 allopurinol non-users who died during follow-up. Allopurinol users and non-users had similar risk for all-cause mortality (hazard ratio 0.99; 95% CI 0.87, 1.12). In the 3-year landmark analysis, 3519 allopurinol users (1280 died) were compared with 3519 non-users (1265 died). The hazard ratio for all-cause mortality was 1.01 (95% CI 0.92, 1.09).
Conclusion: This propensity score–matched landmark analysis in a population of incident gout patients in the UK primary care setting found a neutral effect on the risk of all-cause mortality. Our study provides reassurance about the prescription of allopurinol for gout patients early in their disease course to prevent untoward consequences of chronic uncontrolled hyperuricaemia. However, whether higher than the commonly used dose of allopurinol could influence mortality remains to be determined
Association between use of non–vitamin k oral anticoagulants with and without concurrent medications and risk of major bleeding in nonvalvular atrial fibrillation
Importance: Non–vitamin K oral anticoagulants (NOACs) are commonly prescribed with other medications that share metabolic pathways that may increase major bleeding risk.
Objective: To assess the association between use of NOACs with and without concurrent medications and risk of major bleeding in patients with nonvalvular atrial fibrillation.
Design, Setting, and Participants: Retrospective cohort study using data from the Taiwan National Health Insurance database and including 91 330 patients with nonvalvular atrial fibrillation who received at least 1 NOAC prescription of dabigatran, rivaroxaban, or apixaban from January 1, 2012, through December 31, 2016, with final follow-up on December 31, 2016.
Exposures: NOAC with or without concurrent use of atorvastatin; digoxin; verapamil; diltiazem; amiodarone; fluconazole; ketoconazole, itraconazole, voriconazole, or posaconazole; cyclosporine; erythromycin or clarithromycin; dronedarone; rifampin; or phenytoin.
Main Outcomes and Measures: Major bleeding, defined as hospitalization or emergency department visit with a primary diagnosis of intracranial hemorrhage or gastrointestinal, urogenital, or other bleeding. Adjusted incidence rate differences between person-quarters (exposure time for each person during each quarter of the calendar year) of NOAC with or without concurrent medications were estimated using Poisson regression and inverse probability of treatment weighting using the propensity score.
Results: Among 91 330 patients with nonvalvular atrial fibrillation (mean age, 74.7 years [SD, 10.8]; men, 55.8%; NOAC exposure: dabigatran, 45 347 patients; rivaroxaban, 54 006 patients; and apixaban, 12 886 patients), 4770 major bleeding events occurred during 447 037 person-quarters with NOAC prescriptions. The most common medications co-prescribed with NOACs over all person-quarters were atorvastatin (27.6%), diltiazem (22.7%), digoxin (22.5%), and amiodarone (21.1%). Concurrent use of amiodarone, fluconazole, rifampin, and phenytoin with NOACs had a significant increase in adjusted incidence rates per 1000 person-years of major bleeding than NOACs alone: 38.09 for NOAC use alone vs 52.04 for amiodarone (difference, 13.94 [99% CI, 9.76-18.13]); 102.77 for NOAC use alone vs 241.92 for fluconazole (difference, 138.46 [99% CI, 80.96-195.97]); 65.66 for NOAC use alone vs 103.14 for rifampin (difference, 36.90 [99% CI, 1.59-72.22); and 56.07 for NOAC use alone vs 108.52 for phenytoin (difference, 52.31 [99% CI, 32.18-72.44]; P < .01 for all comparisons). Compared with NOAC use alone, the adjusted incidence rate for major bleeding was significantly lower for concurrent use of atorvastatin, digoxin, and erythromycin or clarithromycin and was not significantly different for concurrent use of verapamil; diltiazem; cyclosporine; ketoconazole, itraconazole, voriconazole, or posaconazole; and dronedarone.
Conclusions and Relevance: Among patients taking NOACs for nonvalvular atrial fibrillation, concurrent use of amiodarone, fluconazole, rifampin, and phenytoin compared with the use of NOACs alone, was associated with increased risk of major bleeding. Physicians prescribing NOAC medications should consider the potential risks associated with concomitant use of other drugs
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