571 research outputs found
Direct-written polymer field-effect transistors operating at 20 MHz
Printed polymer electronics has held for long the promise of revolutionizing technology by delivering distributed, flexible, lightweight and cost-effective applications for wearables, healthcare, diagnostic, automation and portable devices. While impressive progresses have been registered in terms of organic semiconductors mobility, field-effect transistors (FETs), the basic building block of any circuit, are still showing limited speed of operation, thus limiting their real applicability. So far, attempts with organic FETs to achieve the tens of MHz regime, a threshold for many applications comprising the driving of high resolution displays, have relied on the adoption of sophisticated lithographic techniques and/or complex architectures, undermining the whole concept. In this work we demonstrate polymer FETs which can operate up to 20 MHz and are fabricated by means only of scalable printing techniques and direct-writing methods with a completely mask-less procedure. This is achieved by combining a fs-laser process for the sintering of high resolution metal electrodes, thus easily achieving micron-scale channels with reduced parasitism down to 0.19 pF mm(-1), and a large area coating technique of a high mobility polymer semiconductor, according to a simple and scalable process flow
Nonlinearities in Conservative Growth Equations
Using the dynamic renormalization group (DRG) technique, we analyze general
nonlinearities in a conservative nonlinear growth equation with non-conserved
gaussian white noise. We show that they fall in two classes only: the
Edwards-Wilkinson and Lai-Das Sarma types, by explicitly computing the
associated amputated two and three point functions at the first order in
perturbation parameter(s). We further generalize this analysis to higher order
nonlinearities and also suggest a physically meaningful geometric
interpretation of the same.Comment: REVTEX, will appear in Phys Rev E Rapid Comm. February 1996, .ps
figure file available upon request to [email protected]
Pushout bond strength of root fillings after irrigation of root canals utilizing sodium hypochlorite, chlorhexidine, and homeopathic mother tincture (Arnica montana)
The pushout bond strength of root fillings at radicular dentin was investigated employing NaOCl, CHX, and homoeopathic mother tincture (Arnica montana) as an irrigant. Sixty human permanent single-rooted extracted teeth were decoronated. The root canals were instrumented using Pro taper universal rotary system (Dentsply Tulsa Dental; Tulsa, Oklahoma) and were prepared up to F3 apical size. The roots were then randomly divided into three groups according to irrigation solution (n = 20) according to the final irrigation regimen: Group I: 3 mL 5.25% NaOCl followed by 3 mL Saline (control); Group II: 3 mL Arnica montana (10%, w/v) followed by 3 mL Saline; Group III: 3 mL CHX followed by 3 mL Saline. The canals were dried using paper points. The canals were coated with AH Plus sealer (Dentsply DeTey, Konstaz, Germany) with the aid of a Lentulo spiral (Dentsply DeTey, Konstaz, Germany) and obturated with #F3 gutta-percha. Each root was then horizontally sliced into three slices, labelled coronal, middle, and apical, each measuring 2 mm thick. Furthermore, at a crosshead speed of 2 mm/min, the test was carried out using the universal testing apparatus. The 5.25% NaOCl significantly decreased the bond strength of AH Plus to dentin. Both CHX and Arnica montana were capable of reversing the compromised pushout of AH Plus to NaOCl-treated dentin. After using NaOCl as an irrigant, the danger of diminished binding capacity of AH Plus to root canal walls arises. Final irrigation with Arnica montana and CHX reduces this risk
Universality class of the restricted solid-on-solid model with hopping
We study the restricted solid-on-solid (RSOS) model with finite hopping
distance , using both analytical and numerical methods. Analytically, we
use the hard-core bosonic field theory developed by the authors [Phys. Rev. E
{\bf 62}, 7642 (2000)] and derive the Villain-Lai-Das Sarma (VLD) equation for
the case which corresponds to the conserved RSOS (CRSOS) model
and the Kardar-Parisi-Zhang (KPZ) equation for all finite values of .
Consequently, we find that the CRSOS model belongs to the VLD universality
class and the RSOS models with any finite hopping distance belong to the KPZ
universality class. There is no phase transition at a certain finite hopping
distance contrary to the previous result. We confirm the analytic results using
the Monte Carlo simulations for several values of the finite hopping distance.Comment: 13 pages, 3 figure
Combination therapy improves survival after acute myocardial infarction in the elderly with chronic kidney disease
Background: Individuals with chronic kidney disease have a high mortality rate after acute myocardial infarction. It is not known how frequently these individuals are prescribed combination cardioprotective therapy and if survival is affected by such therapy after acute myocardial infarction. Methods: A retrospective cohort study of 1,342 Medicare recipients with acute myocardial infarction. Data were collected by medical chart abstraction as part of the Cooperative Cardiovascular Project in 60 hospitals in North Carolina during 5/30/1996-12/28/1997. We categorized cardioprotective medication use as aspirin alone, aspirin with beta-blockers, and aspirin with beta-blockers and ace-inhibitors. Chronic kidney disease was defined as a derived glomerular filtration rate (GFR) ranging from 15-89 mL/min/1.73 m2. Cox proportional hazards regression analyses were performed to determine the effect of cardioprotective medication use on survival while controlling for potential explanatory variables. Results: The prevalence of cardioprotective medication use differed among levels of chronic kidney disease. Those with severe kidney disease (GFR 15-29 mL/min/1.73 m2) were less frequently prescribed aspirin with beta-blockers, 27.1%, and only 8.6% were prescribed aspirin with beta-blockers and ace-inhibitors. Survival was improved with prescribed cardioprotective medication use. In severe kidney disease (GFR 15-29 mL/min/1.73 m2), the hazards risk for death was 0.21 (0.08, 0.53) for aspirin alone, 0.17 (0.06, 0.51) for aspirin with beta-blockers, and 0.35 (0.09, 1.42) for aspirin with beta-blockers and ace-inhibitors. Conclusions: Individuals with chronic kidney disease benefit from combination cardioprotective therapy, but are less likely to be prescribed them after acute myocardial infarction. Further investigation is warranted to identify possible reasons for these observed treatment disparities
Negligible particle-specific toxicity mechanism of silver nanoparticles: The role of Ag+ion release in the cytosol
Toxicity of silver nanoparticles (AgNPs) is supported by many observations in literature, but no mechanism details have been proved yet. Here we confirm and quantify the toxic potential of fully characterized AgNPs in HeLa and A549 cells. Notably, through a specific fluorescent probe, we demonstrate the intracellular release of Ag+ ions in living cells after nanoparticle internalization, showing that in-situ particle degradation is promoted by the acidic lysosomal environment. The activation of metallothioneins in response to AgNPs and the possibility to reverse the main toxic pathway by Ag+ chelating agents demonstrate a cause/effect relationship between ions and cell death. We propose that endocytosed AgNPs are degraded in the lysosomes and the release of Ag+ ions in the cytosol induces cell damages, while ions released in the cell culture medium play a negligible effect. These findings will be useful to develop safer-by-design nanoparticles and proper regulatory guidelines of AgNPs
Derivation of continuum stochastic equations for discrete growth models
We present a formalism to derive the stochastic differential equations (SDEs)
for several solid-on-solid growth models. Our formalism begins with a mapping
of the microscopic dynamics of growth models onto the particle systems with
reactions and diffusion. We then write the master equations for these
corresponding particle systems and find the SDEs for the particle densities.
Finally, by connecting the particle densities with the growth heights, we
derive the SDEs for the height variables. Applying this formalism to discrete
growth models, we find the Edwards-Wilkinson equation for the symmetric
body-centered solid-on-solid (BCSOS) model, the Kardar-Parisi-Zhang equation
for the asymmetric BCSOS model and the generalized restricted solid-on-solid
(RSOS) model, and the Villain--Lai--Das Sarma equation for the conserved RSOS
model. In addition to the consistent forms of equations for growth models, we
also obtain the coefficients associated with the SDEs.Comment: 5 pages, no figur
Concept Graph Learning from Educational Data
This paper addresses an open challenge in educational data mining, i.e., the problem of using observed prerequisite re-lations among courses to learn a directed universal con-cept graph, and using the induced graph to predict un-observed prerequisite relations among a broader range of courses. This is particularly useful to induce prerequisite relations among courses from different providers (universi-ties, MOOCs, etc.). We propose a new framework for in-ference within and across two graphs—at the course level and at the induced concept level—which we call Concept Graph Learning (CGL). In the training phase, our system projects the course-level links onto the concept space to in-duce directed concept links; in the testing phase, the concept links are used to predict (unobserved) prerequisite links for test-set courses within the same institution or across insti-tutions. The dual mappings enable our system to perform an interlingua-style transfer learning, e.g. treating the con-cept graph as the interlingua, and inducing prerequisite links in a transferable manner across different universities. Ex-periments on our newly collected data sets of courses fro
Full potential LAPW calculation of electron momentum density and related properties of Li
Electron momentum density and Compton profiles in Lithium along , and directions are calculated using Full-Potential Linear
Augmented Plane Wave basis within generalized gradient approximation. The
profiles have been corrected for correlations with Lam-Platzman formulation
using self-consistent charge density. The first and second derivatives of
Compton profiles are studied to investigate the Fermi surface breaks. Decent
agreement is observed between recent experimental and our calculated values.
Our values for the derivatives are found to be in better agreement with
experiments than earlier theoretical results. Two-photon momentum density and
one- and two-dimensional angular correlation of positron annihilation radiation
are also calculated within the same formalism and including the
electron-positron enhancement factor.Comment: 11 pages, 7 figures TO appear in Physical Review
Serum Lipopolysaccharide Activity Is Associated With the Progression of Kidney Disease in Finnish Patients With Type 1 Diabetes
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