Publications by authors named "Steffensen G"

One of the most promising approaches towards large-scale quantum computation uses devices based on many Josephson junctions. Yet, even today, open questions regarding the single junction remain unsolved, such as the detailed understanding of the quantum phase transitions, the coupling of the Josephson junction to the environment or how to improve the coherence of a superconducting qubit. Here we design and build an engineered on-chip reservoir connected to a Josephson junction that acts as an efficient bolometer for detecting the Josephson radiation under non-equilibrium, that is, biased conditions.

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Understanding heating and cooling mechanisms in mesoscopic superconductor-semiconductor devices is crucial for their application in quantum technologies. Owing to their poor thermal conductivity, heating effects can drive superconducting-to-normal transitions even at low bias, observed as sharp conductance dips through the loss of Andreev excess currents. Tracking such dips across magnetic field, cryostat temperature, and applied microwave power allows us to uncover cooling bottlenecks in different parts of a device.

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Hybrid superconductor-semiconductor devices offer highly tunable platforms, potentially suitable for quantum technology applications, that have been intensively studied in the past decade. Here we establish that measurements of the superconductor-to-normal transition originating from Joule heating provide a powerful spectroscopical tool to characterize such hybrid devices. Concretely, we apply this technique to junctions in full-shell Al-InAs nanowires in the Little-Parks regime and obtain detailed information of each lead independently and in a single measurement, including differences in the superconducting coherence lengths of the leads, inhomogeneous covering of the epitaxial shell, and the inverse superconducting proximity effect; all-in-all constituting a unique fingerprint of each device with applications in the interpretation of low-bias data, the optimization of device geometries, and the uncovering of disorder in these systems.

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By using scanning tunneling microscopy (STM) we find and characterize dispersive, energy-symmetric in-gap states in the iron-based superconductor FeTeSe, a material that exhibits signatures of topological superconductivity, and Majorana bound states at vortex cores or at impurity locations. We use a superconducting STM tip for enhanced energy resolution, which enables us to show that impurity states can be tuned through the Fermi level with varying tip-sample distance. We find that the impurity state is of the Yu-Shiba-Rusinov (YSR) type, and argue that the energy shift is caused by the low superfluid density in FeTeSe, which allows the electric field of the tip to slightly penetrate the sample.

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Background: In a Danish family, multiple individuals in five generations present with early-onset paroxysmal cranial dyskinesia, musculoskeletal abnormalities, and kidney dysfunction.

Objective: To demonstrate linkage and to identify the underlying genetic cause of disease.

Methods: Genome-wide single-nucleotide polymorphisms analysis, Sequence-Tagged-Site marker analyses, exome sequencing, and Sanger sequencing were performed.

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We demonstrate the Josephson effect in a serial double quantum dot defined in a nanowire with epitaxial superconducting leads. The supercurrent stability diagram adopts a honeycomb pattern. We observe sharp discontinuities in the magnitude of the critical current, I_{c}, as a function of dot occupation, related to doublet to singlet ground state transitions.

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A magnetic impurity coupled to a superconductor gives rise to a Yu-Shiba-Rusinov (YSR) state inside the superconducting energy gap. With increasing exchange coupling the excitation energy of this state eventually crosses zero and the system switches to a YSR ground state with bound quasiparticles screening the impurity spin by ħ/2. Here we explore indium arsenide (InAs) nanowire double quantum dots tunnel coupled to a superconductor and demonstrate YSR screening of spin-1/2 and spin-1 states.

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Unilateral renal cystic disease (URCD) is a rare, non-familial non-progressive renal disorder not associated with cysts in other organs in contrast to autosomal dominant polycystic kidney disease. Only 55 cases have been published in the world literature. Renal diseases are a well-recognized etiology of secondary erythrocytosis but not in URCD.

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Objective: Subcutaneous (s.c.) administration of erythropoietin (EPO) is recommended over the intravenous (i.

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Children's compliance with orally administered medicine is described. Five hundred questionnaires were given to the parents of children at their first visit at the out-patient clinic with a response from 484. Three hundred and ninety-seven children had been treated with oral medication in the form of liquid formulation or tablets, 257 within the previous year.

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Objective: The purpose of the present study was to compare the dosage requirements of recombinant human erythropoletin (rHuEPO) administered subcutaneously (SC) either one or three times weekly.

Design: A randomized, prospective study.

Setting: The patients were recruited from two university hospitals and five county hospitals.

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Fifteen patients with end-stage renal disease (ESRD) were blood sampled before and 1-, 2-, 3-, and 6 months after institution of recombinant human erythropoietin (r-HuEPO) therapy. Subpopulations of immunocompetent peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry using monoclonal antibodies against various T-lymphocyte antigens, B-lymphocytes, natural killer (NK)-cells, monocytes, and macrophages, and finally bone marrow progenitor cells. Functional properties of peripheral T-lymphocytes were analyzed by proliferation assays with mitogens, alloantigens and microbiological antigens.

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1. The aim of this pharmacokinetic study was to evaluate to what extent oropharyngeal deposition of drug contributes to the systemic availability of budesonide inhaled from a dry powder inhaler (Turbuhaler). 2.

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In 10 female and 10 male haemodialysis patients plasma FSH, LH, testosterone, prolactin, and somatotropin (STH) were estimated during erythropoietin (rHuEpo) treatment for 6 months. All but one patient responded with an increase in haemoglobin. The patients experienced improved sexual function according to the answers given in a self-administered questionnaire.

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A major adverse effect of recombinant human erythropoietin (r-HuEPO) in hemodialyzed patients are thrombotic events. Several reports on platelet function during r-HuEPO treatment have been published but less is known about fibrinolysis. In the present study, the fibrinolytic capacity was studied in 20 patients on maintenance hemodialysis and treated with r-HuEPO.

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Two cases of the oculo-cerebro-renal syndrome of Lowe are reported, in which the course of the disease was very fast and unusual. Within the first hours after birth the patients developed nephrotic syndrome and died at the age of 45 and 4 days, respectively. Renal tissue obtained by biopsy and at autopsy disclosed pronounced glomerular changes.

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When the nephrotic syndrome develops within the first 3 months of life it is considered as congenital. In a review, different types of renal diseases are found behind the syndrome in early infancy. A classification of these is proposed, based on clinicopathology.

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Medullary cystic disease (MCD) is an uncommon renal disease with adult onset and autosomal inheritance, eventually progressing to terminal renal failure. It may be difficult to identify because of insufficient diagnostic tools. At urography, the same ring-shaped accumulation of contrast medium at the corticomedullary junction was observed in two patients (mother and son) suffering from MCD.

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The recommended dose of intravenous IgG for idiopathic thrombocytopenic purpura has been 0.4 g/kg on 5 consecutive days. A simplified approach, giving a single infusion of 0.

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The single- and multiple-dose absorption characteristics of a new sustained-release theophylline preparation, which has been formulated for once per day dosing in adults, were investigated in children aged 8 to 14 years. Four single doses were studied, each dose separated by 1 week. During steady state the preparation was given once daily in the morning for 1 week, and serum theophylline concentration was determined through two dosing intervals (48 hours).

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