3,712 research outputs found
Electrically detected magnetic resonance of carbon dangling bonds at the Si-face 4H-SiC/SiO interface
SiC based metal-oxide-semiconductor field-effect transistors (MOSFETs) have
gained a significant importance in power electronics applications. However,
electrically active defects at the SiC/SiO interface degrade the ideal
behavior of the devices. The relevant microscopic defects can be identified by
electron paramagnetic resonance (EPR) or electrically detected magnetic
resonance (EDMR). This helps to decide which changes to the fabrication process
will likely lead to further increases of device performance and reliability.
EDMR measurements have shown very similar dominant hyperfine (HF) spectra in
differently processed MOSFETs although some discrepancies were observed in the
measured -factors. Here, the HF spectra measured of different SiC MOSFETs
are compared and it is argued that the same dominant defect is present in all
devices. A comparison of the data with simulated spectra of the C dangling bond
(P) center and the silicon vacancy (V) demonstrates
that the P center is a more suitable candidate to explain the
observed HF spectra.Comment: Accepted for publication in the Journal of Applied Physic
Functional DNAâPolymer Conjugates
[Image: see text] DNA nanotechnology has seen large developments over the last 30 years through the combination of solid phase synthesis and the discovery of DNA nanostructures. Solid phase synthesis has facilitated the availability of short DNA sequences and the expansion of the DNA toolbox to increase the chemical functionalities afforded on DNA, which in turn enabled the conception and synthesis of sophisticated and complex 2D and 3D nanostructures. In parallel, polymer science has developed several polymerization approaches to build di- and triblock copolymers bearing hydrophilic, hydrophobic, and amphiphilic properties. By bringing together these two emerging technologies, complementary properties of both materials have been explored; for example, the synthesis of amphiphilic DNAâpolymer conjugates has enabled the production of several nanostructures, such as spherical and rod-like micelles. Through both the DNA and polymer parts, stimuli-responsiveness can be instilled. Nanostructures have consequently been developed with responsive structural changes to physical properties, such as pH and temperature, as well as short DNA through competitive complementary binding. These responsive changes have enabled the application of DNAâpolymer conjugates in biomedical applications including drug delivery. This review discusses the progress of DNAâpolymer conjugates, exploring the synthetic routes and state-of-the-art applications afforded through the combination of nucleic acids and synthetic polymers
From algebra to logic: there and back again -- the story of a hierarchy
This is an extended survey of the results concerning a hierarchy of languages
that is tightly connected with the quantifier alternation hierarchy within the
two-variable fragment of first order logic of the linear order.Comment: Developments in Language Theory 2014, Ekaterinburg : Russian
Federation (2014
Opicapone Efficacy and Tolerability in Parkinson's Disease Patients Reporting Insufficient Benefit/Failure of Entacapone
Background: Opicapone, a recently introduced catecholâoâmethyl transferase (COMT) inhibitor has the advantage of being administered once daily, and has pharmacokinetic data to indicate it offers a greater degree of COMT inhibition than entacapone. Although trial data indicate it is nonâinferior to entacapone, there are no data to indicate whether it offers any clinical advantages. /
Methods: In this audit, we present data from 57 individuals prescribed opicapone at the National Hospital for Neurology and Neurosurgery, Queen Square who had either not tolerated or reported insufficient benefit following previous prescription of entacapone. /
Results: A total of 20 of 57 patients switched directly from entacapone to opicapone (âentacapone switchersâ) whereas 37 of 57 patients had previously discontinued entacapone because of lack of benefit or adverse events (âentacapone failuresâ). A total of 21 of 57 (37%) patients stopped opicapone prior to 6âmonths. A total of 7 of 20 (35%) âentacapone switchersâ experienced adverse events with opicapone of which 5 stopped the drug prior to the 6âmonth evaluation of efficacy. A total of 23 of 37 (62%) âentacapone failuresâ reported adverse events of which 16 stopped the drug. Among 36 of 57 (63%) patients who continued to use opicapone at 6âmonths, there was an improvement in OFF time of ~2âhours per day as measured by interview. /
Conclusions: We conclude that opicapone can be an effective additional treatment for wearing off in Parkinson's disease (PD) in a subgroup of patients. The use of opicapone in our cohort with prior entacapone exposure, however, was associated with higher rates of adverse effects and treatment discontinuation than reported in published trial data of COMT inhibitor naĂŻve patients
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