1,306 research outputs found
Erratum
No full textThis article corrects the following:Interpretation of pediatric lung function: Impact of ethnicityJ. Kirkby, R. Bonner, S. Lum, P. Bates, V. Morgan, R.C. Strunk, F. Kirkham, S. Sonnappa, J. StocksVolume 48, Issue 1, Pediatric Pulmonology, pages: 20-26, First Published online: March 19, 201
Instrumente der Professorenauswahl als zentraler Bestandteil von Berufungsverfahren an Universitäten: Entwicklung eines Entscheidungsrahmens.
No full textStrunk C. Instrumente der Professorenauswahl als zentraler Bestandteil von Berufungsverfahren an Universitäten: Entwicklung eines Entscheidungsrahmens. Bielefeld: Universität Bielefeld; 2018
Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe
No full textWe report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials
Trinity, polyphony and pastoral relationships
No full textThe author explores the Christian doctrine of the Trinity to shed light on the nature of the pastoral ministry. Using the trinitarian term, "polyphony" (David Cunningham) for this purpose, he explicates unity and difference as key polyphonic categories in the doctrine of the Trinity. The author suggests that the polyphonic notes sounded by pastoral caregivers are toughness and tenderness, woundedness and health, wisdom and folly, and communion, nearness and distance
Investigation of carbon nanotube quantum dots connected to ferromagnetic leads
No full textThe implementation of ferromagnetic contacts in complex nanoelectronic devices,
e.g. in spin-valves bears great potential for applications and fundamental
investigations. Spin-valves are structures with two magnetic contacts and
a non-magnetic medium (M) in-between, where a step-like change in magnetoresistance
(MR) is observed when the relative orientation of the strip magnetization
is changed by an external magnetic field. There is already a very
successful use of the electron spin in electronic devices for magnetic field sensing
for example in read-and-write heads of computer hard discs. Another upcoming
application of spin valves are for example non-volatile random-access
memories (MRAMs) for data storage.
However, electronic devices which use the electron spin directly, like in a spintransistor
or as quantum bits requires materials for the non-magnetic
medium exhibiting long coherence times and electrical tunability. Carbon
based materials like graphene or carbon nanotubes are due to their intrinsic
large coherence times in principle ideal candidates for spintronic devices, as
demonstrated in nonlocal spin-accumulation experiments on graphene or in
electrically tunable spin valves on carbon nanotubes.
Especially the observation of a gate dependent magneto-resistance in carbon
nanotube quantum dots contacted with ferromagnetic leads in 2005 by S. Sahoo
promises an electrical control over spin transport. These devices analog
to field-effect transistors might pave the way for multi-functional spintronic
devices. However, the implementation of ferromagnetic contacts in nanoelectronic
devices has been a proven challenging task due to the complex nature
of ferromagnets and interfaces, where oxidation, surface roughness and mesoscopic
details may induce uncontrolled instabilities in transport measurements.
Spintransport experiments on carbon nanotube quantum dots suffer mainly
from irreproducibilities in the magneto resistance and from the low yield of
electrical contacts to the nanotube. Therefore in this thesis carbon nanotube
quantum dots connected to ferromagnetic leads are investigated, focusing on
the fabrication of stable devices with higher contact yields and first experiments
on stable devices. This allows for further investigations of the not well
understood gate dependence of the magneto resistance in such devices. Moreover
with such stable devices, even more complex experiments or applications like detectors
for spin entanglement can become possible
Increased risk of severe vaso-occlusive episodes after initial acute chest syndrome in children with sickle cell anemia less than 4 years old: Sleep and asthma cohort
No full textPrevious studies have shown that the highest incidence of acute chest syndrome (ACS) in sickle cell disease occurs in children <4 years old, and a history of ACS at this age is a risk factor for future ACS episodes. However, the interval associated with the highest risk of subsequent ACS or severe pain is not known. Through this mixed retrospective-prospective observational study, the Sleep and Asthma Cohort, we sought to determine the interval after an initial ACS episode during which the majority of children <4 years old are rehospitalized for ACS or severe pain. The cumulative prevalence of rehospitalization for ACS or severe pain within 6 months, 1 years, and 2 years was calculated for children with an initial ACS episode <4 years old and compared to children with an initial ACS episode ≥4 years old. A total of 44.8% and 55.2% of participants had an initial ACS episode <4 years and ≥4 years old (Range: 4-17.7 years), respectively. At 1 year following the initial ACS episode, children <4 years old had a significantly higher cumulative prevalence of rehospitalizations for ACS or pain as compared to children ≥4 years of age, 62.5 and 39.1%, respectively (P = 0.009). After initial ACS episodes, the majority of children <4 years old will be rehospitalized for ACS or severe pain within one year, suggesting the need for a therapeutic intervention for this high-risk group.</p
Incomplete Ozone Loss and Weak Mixing in the outer Antarctic Vortex derived from airborne in situ observations
No full textAnnual Academy of Sickle Cell and Thalassaemia (ASCAT) conference: a summary of the proceedings
No full textThe fourteenth annual ASCAT conference was held 21–23 October 2019. The theme of the conference was ‘Sickle Cell and Thalassaemia disorders new treatment horizon; while ensuring patient safety and delivering excellence in routine patient care.’ Over the three-day conference, topics on current and novel models of care, advances in bone marrow transplant and gene therapy, as well as the psychosocial aspects of mind, body and health related quality of life were discussed. In addition, blood transfusion, apheresis, iron chelation therapy and acute haemolytic complications were presented. Quality standards in the diagnosis and treatment of sickle cell and thalassaemia were reviewed. Experts from Europe, the United Kingdom, the Middle East, the United States and Africa reported up-to-date scientific data, guides to comprehensive care, and current research into developing cures and advancing current therapy were described. In addition, oral and poster presentations on novel research from all over the world were shown during the conference
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