114 research outputs found
Study of the structure and electrostrictive property of proton-irradiated P(VDF-TrFE) 56/44 mol% copolymer
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Ablação ocular no camarão Macrobrachium rosenbergii (De Man) (Crustacea, Decapoda, Palaemonidae): efeitos sobre a reprodução, pigmentação epidérmica e atividade alimentar
The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set
Background
Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables.
Methods
Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set.
Results
Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001).
Conclusions
The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy
Sources of business financing and financing practices: A comparison among U.S. and Asian countries
Journal of Business Venturing55271-275JBVE
(Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-(Bi1/2Li1/2)TiO3-BaTiO3 lead-free ceramic fibres fabricated by a powder-based extrusion method
Lead-free bismuth sodium potassium lithium titanate—barium titanate [0.885 (Bi1/2Na1/2)TiO3-0.05(Bi1/2K1/2)TiO3–0.015(Bi1/2Li1/2)TiO3-0.05BaTiO3, BNKLBT-1.5] fibres have been fabricated by a powder-based extrusion method. The ceramic fibres with 400 μ m diameter were well-crystallized after being calcined at 800°C and sintered at 1170°C. After being poled, the electromechanical coupling coefficient k33 of the fibre is 0.55 while other properties are comparable to those a ceramic disc. The BNKLNT ceramic fibres prepared by the powder-based extrusion method have good piezoelectric and ferroelectric properties and have potential to replace lead zirconate titanate (PZT) fibres in various device applications
A piezoelectric-metal-cavity (PMC) actuator
A novel piezoelectric-metal-cavity (PMC) actuator has been designed to exhibit a large flexural displacement. This PMC actuator consists of a metal ring sandwiched between two identical piezoelectric unimorphs. The radial contraction of the piezoelectric ceramic is converted into flextensional motion of the unimorph, causing a large flexural displacement in the centre part of the actuator. The metal cavity acts a function of circumferential coupling of the piezoelectric unimorphs. It was found that the effective piezoelectric charge coefficient of the PMC actuator can approach 40,000 pC/N. With its high piezoelectric and electromechanical coupling coefficients, the PMC actuator gives a static displacement 16 μm can be produced under a d.c. driving voltage of ±77 V
A novel drum piezoelectric-actuator
This paper presents a large displacement, piezoelectric-metal structure actuator, named the piezoelectric drum actuator. The drum actuator consists of a short, thick-walled steel cylinder sandwiched by two thin composite disks, which are fabricated from a brass disk bonded with a piezoceramic disk. The piezoceramic disk, which is polarized in its thickness direction, has a large diameter thickness ratio, producing a large radial displacement under an applied voltage in the thickness, leading to a large transverse deflection of the composite disks in the drum. The drum (outer diameter: 12.0 mm) has a displacement that is about eight times larger than that of a cymbal actuator made with the same ceramic material and comparable dimensions under the same dc driving voltage of 270 V. The drum actuator also showed a large resonance displacement of 56.7 μm under an ac voltage of 90 V. The effective piezoelectric charge coefficient d’33 of the drum is about twice as large as that reported for the cymbal
Dielectric properties and relaxation of SrBi2(Nb0.25Ta0.75)2O9 ceramic at RF frequency
The dielectric properties and relaxation of the SrBi2(Nb0.25Ta0.75)2O9 ceramic were investigated from 3 to 300 MHz using frequency domain measurement by an impedance spectroscopy. Our results show that the dielectric relaxation of the ceramic can be understood in terms of power law dependence known as the Curie-von Schweidler law. It is assumed that defects, Schottkey jumps of electrons between localized states and the motions of ions play an important role in the dielectric properties and relaxation of the ceramic. The ceramic has large relative permittivity (*er ~117 at 300 MHz), low dielectric loss (tan*de < 0.018 at 300 MHz) and small dispersion ( < 3% decrease in *er from 3 to 300 MHz). The Curie temperature of the ceramic is very high (~370 DGC), implying that it has a small temperature coefficient. Hence the SrBi2(Nb0.25Ta0.75)2O9 ceramic is a potential candidate for microwave applications
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