1,755 research outputs found
Comparative study of Clâ‚‚, Clâ‚‚/Oâ‚‚, and Clâ‚‚/Nâ‚‚ inductively coupled plasma processes for etching of high-aspect-ratio photonic-crystal holes in InP
An extensive investigation has been performed on inductively coupled plasmaetching of InP. An important motivation for this work is the fabrication of high-aspect-ratio holes for photonic crystals. The essential chemistry is based on Clâ‚‚ with the addition of Nâ‚‚ or Oâ‚‚ for sidewall passivation. The influence of different process parameters such as gas flows, temperature,pressure, ion energy, and inductively coupled plasma power on the hole geometry is presented. It is concluded that photonic crystals can be etched with Clâ‚‚ only; however, temperature and pressure control is critical. Adding passivation gases largely broadens the window in the parameter space for hole etching. Most importantly, etching of narrow holes can be carried out at higher temperatures where the etching is mass limited and spontaneous etching of InP by Clâ‚‚ occurs.Part of this research is supported by NanoNed, a technology program of the Dutch
Ministry of Economic Affairs
Integrability of a conducting elastic rod in a magnetic field
We consider the equilibrium equations for a conducting elastic rod placed in
a uniform magnetic field, motivated by the problem of electrodynamic space
tethers. When expressed in body coordinates the equations are found to sit in a
hierarchy of non-canonical Hamiltonian systems involving an increasing number
of vector fields. These systems, which include the classical Euler and
Kirchhoff rods, are shown to be completely integrable in the case of a
transversely isotropic rod; they are in fact generated by a Lax pair. For the
magnetic rod this gives a physical interpretation to a previously proposed
abstract nine-dimensional integrable system. We use the conserved quantities to
reduce the equations to a four-dimensional canonical Hamiltonian system,
allowing the geometry of the phase space to be investigated through Poincar\'e
sections. In the special case where the force in the rod is aligned with the
magnetic field the system turns out to be superintegrable, meaning that the
phase space breaks down completely into periodic orbits, corresponding to
straight twisted rods.Comment: 19 pages, 1 figur
Scenario planning for the Edinburgh city region
This paper examines the application of scenario planning techniques to the detailed and daunting challenge of city re-positioning when policy makers are faced with a heavy history and a complex future context. It reviews a process of scenario planning undertaken in the Edinburgh city region, exploring the scenario process and its contribution to strategies and policies for city repositioning. Strongly rooted in the recent literature on urban and regional economic development, the text outlines how key individuals and organisations involved in the process participated in far-reaching analyses of the possible future worlds in which the Edinburgh city region might find itself
InP-based two-dimensional photonic crystals filled with polymers
Polymer filling of the air holes of Indium Phosphide based two-dimensional
photonic crystals is reported. After infiltration of the holes with a liquid
monomer and solidification of the infill in situ by thermal polymerization,
complete filling is proven using scanning electron microscopy. Optical
transmission measurements of a filled photonic crystal structure exhibit a
redshift of the air band, confirming the complete filling.Comment: To be published in Appl. Phys. Let
Outcome of atypical haemolytic uraemic syndrome relapse after eculizumab withdrawal
Background. The introduction of eculizumab has significantly improved the outcome of patients with atypical haemolytic uraemic syndrome (aHUS). Because of the risk of relapse after discontinuation, eculizumab was proposed as life-long therapy. However, data on the outcome of relapse are limited. In the Netherlands, patients with aHUS are treated with a restrictive eculizumab regime and are included in a national observational study (CUREiHUS, Dutch Trial Register NTR5988/NL5833). Methods. For this interim safety analysis, we evaluated the outcome of all adult patients with a suspected relapse, defined as the need to intensify eculizumab after tapering or withdrawal of therapy. Results. We describe 11 patients who received renewed eculizumab therapy because of suspected relapse. In three patients with aHUS in native kidneys, estimated glomerular filtration rate (eGFR) returned to baseline value and remained stable without overt proteinuria after follow-up. Six out of eight transplanted patients responded to eculizumab therapy with improvement in eGFR. After a median follow-up of 24.6 months, a reduction of eGFR >= 25% was observed in three of these transplanted patients, which was attributed to the aHUS relapse in only one patient. Conclusions. This interim analysis suggests that re-treatment with eculizumab after relapse is safe and feasible. We will continue to use our restrictive treatment strategy
Resonant tunneling spectroscopy of valley eigenstates on a donor-quantum dot coupled system
We report on electronic transport measurements through a silicon double quantum dot consisting of a donor and a quantum dot. Transport spectra show resonant tunneling peaks involving different valley states, which illustrate the valley splitting in a quantum dot on a Si/SiO2 interface. The detailed gate bias dependence of double dot transport allows a first direct observation of the valley splitting in the quantum dot, which is controllable between 160 and 240 μeV with an electric field dependence 1.2 ± 0.2 meV/(MV/m). A large valley splitting is an essential requirement for implementing a physical electron spin qubit in a silicon quantum dot
Diagnostic value of a heart-type fatty acid-binding protein (H-FABP) bedside test in suspected acute coronary syndrome in primary care
AbstractBackgroundTo determine the diagnostic accuracy of a rapid heart-type fatty acid-binding protein (H-FABP) test in patients suspected of acute coronary syndrome (ACS) in primary care.MethodsGeneral practitioners included 298 patients suspected of ACS. In all patients, whether referred to hospital or not, ECG and cardiac biomarker testing was performed. ACS was determined in accordance with international guidelines. Multivariate analysis was used to determine the value of H-FABP in addition to clinical findings.ResultsMean patient age was 66years (SD 14), 52% was female and 66 patients (22%) were diagnosed with ACS. The H-FABP bedside test was performed within 24h (median 3.1, IQR 1.5 to 7.1) after symptom onset. The positive predictive value (PPV) of H-FABP was 65% (95% confidence interval (CI) 50–78). The negative predictive value (NPV) was 85% (95% CI 80–88). Sensitivity was 39% (29–51%) and specificity 94% (90–96%). Within 6h after symptom onset, the PPV was 72% (55–84) and the NPV was 83% (77–88), sensitivity 43% (31–57%) and specificity 94% (89–97%). Adding the H-FABP test to a diagnostic model for ACS led to an increase in the area under the receiver operating curve from 0.66 (95% CI 0.58–0.73) to 0.75 (95% CI 0.68–0.82).ConclusionThe H-FABP rapid test provides modest additional diagnostic certainty in primary care. It cannot be used to safely exclude rule out ACS. The test can only be used safely in patients otherwise NOT referred to hospital by the GP, as an extra precaution not to miss ACS (‘rule in’)
COMPARE LAAO: Rationale and design of the randomized controlled trial "COMPARing Effectiveness and safety of Left Atrial Appendage Occlusion to standard of care for atrial fibrillation patients at high stroke risk and ineligible to use oral anticoagulation therapy"
Contains fulltext :
252137.pdf (Publisher’s version ) (Open Access)BACKGROUND: Left atrial appendage occlusion (LAAO) provides an alternative to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation (AF). In patients with a long-term or permanent contraindication for OAC randomized controlled trial (RCT) data is lacking. STUDY OBJECTIVES: To assess the efficacy and safety of LAAO in AF patients who are ineligible to use OAC. The co-primary efficacy endpoint is (1) time to first occurrence of stroke (ischemic, hemorrhagic, or undetermined) and (2) time to first occurrence of the composite of stroke, transient ischemic attack (TIA), and systemic embolism (SE). The primary safety endpoint is the 30-day rate of peri-procedural complications. STUDY DESIGN: This is a multicenter, investigator-initiated, open-label, blinded endpoint (PROBE), superiority-driven RCT. Patients with AF, a CHA₂DS₂-VASc score ≥2 for men and ≥3 for women and a long-term or permanent contraindication for OAC will be randomized in a 2:1 fashion to the device- or control arm. Patients in the device arm will undergo percutaneous LAAO and will receive post-procedural dual antiplatelet therapy (DAPT) per protocol, while those in the control arm will continue their current treatment consisting of no antithrombotic therapy or (D)APT as deemed appropriate by the primary responsible physician. In this endpoint-driven trial design, assuming a 50% lower stroke risk of LAAO compared to conservative treatment, 609 patients will be followed for a minimum of 1 and a maximum of 5 years. Cost-effectiveness and budget impact analyses will be performed to allow decision-making on reimbursement of LAAO for the target population in the Netherlands. SUMMARY: The COMPARE LAAO trial will investigate the clinical superiority in preventing thromboembolic events and cost-effectiveness of LAAO in AF patients with a high thromboembolic risk and a contraindication for OAC use. NCT TRIAL NUMBER: NCT04676880
the State of Utah v. Walter Preston Boggess, Jr. : Brief of Respondent
An Appeal from a Judgment of the District Court of the Fourth Judicial District, The Honorable J, Robert Bullock, District Court Judg
Identification of particles with Lorentz factor up to with Transition Radiation Detectors based on micro-strip silicon detectors
This work is dedicated to the study of a technique for hadron identification
in the TeV momentum range, based on the simultaneous measurement of the
energies and of the emission angles of the Transition Radiation (TR) X-rays
with respect to the radiating particles. A detector setup has been built and
tested with particles in a wide range of Lorentz factors (from about to
about crossing different types of radiators. The measured
double-differential (in energy and angle) spectra of the TR photons are in a
reasonably good agreement with TR simulation predictions.Comment: 31 pages, 12 figures, paper published on Nuclear Instruments &
Methods
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