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A simulation scheme based on nonequilibrium Green's functions for biased periodic semiconductor heterostructure devices is presented in detail. The implementation can determine current and optical gain both for small and large optical fields. Specific results for superlattices, quantum cascade lasers, and quantum cascade detectors are shown which demonstrate the capabilities of the approach.

Background: Age, gender and socioeconomic status have been shown to be associated with the use of prescription drugs, even after adjustment for multimorbidity. General practitioners have a holistic and patient-centred perspective and our hypothesis is that this may reflect on the prescription of drugs. In Sweden the patient may seek secondary care without a letter of referral and the liability of

Background: Randomized placebo-controlled trials represent the gold standard in evaluating healthcare interventions but are rarely performed within orthopedics. Ethical concerns or well-known challenges in recruiting patients for surgical trials in general have been expressed and adding a placebo component only adds to this complexity. The purpose of this study was to report the challenges of recr

The objective was to develop evidence -based recommendations and a research and educational agenda for the non-pharmacological management of hip and knee osteoarthritis (OA). The multidisciplinary task force comprised 21 experts: nurses, occupational therapists, physiotherapists, rheumatologists, orthopaedic surgeons, general practitioner, psychologist, dietician, clinical epidemiologist and patie

BACKGROUND AND PURPOSE: Differences in risk factor profiles between lacunar and other ischemic stroke subtypes may provide evidence for a distinct lacunar arteriopathy, but existing studies have limitations. We overcame these by pooling individual data on 2875 patients with first-ever ischemic stroke from 5 collaborating prospective stroke registers that used similar, unbiased methods to define ri

The aim of the present study was to identify patterns of background factors related to the early RA patients' conceptions of the cause of the disease. Conceptions from a qualitative study formed the basis for the stratification of 785 patients from the Swedish EIRA study answering a question about their own thoughts about the cause to RA. Logistic regression analyses were used to explore the assoc

Time-resolved terahertz spectroscopy was employed for the investigation of charge-transport dynamics in benzothiadiazolo-dithiophene polyfluorene ([2,7-(9,9-dioctylfluorene)-alt-S,S-(4',7'-di-2-thieny1-2',1',3'-benzothiadiazole)]) (APFO-3) polymers with various chain lengths and in its monomer form, all blended with an electron acceptor ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM). Upon phot

Second harmonic generation is analyzed from a microscopical point of view using a non-equilibrium Green's function formalism. Through this approach the complete on-state of the laser can be modeled and results are compared to experiment with good agreement. In addition, higher order current response is extracted from the calculations and together with waveguide properties, these currents provide t

Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, were predicted two decades ago but have to date not been observed in experiments. Recent works have predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising the question whether they exist in practice. Here, we answer this question affirmatively by experimentally verifying the

We present the results of a quantum mechanical modelling of the free carrier absorption (FCA) in semiconductor heterolayers. Elastic and inelastic scatterers are considered with emphasis on the interface defects (optical phonons) contributions to the induced photon absorption for elastic (inelastic) scatterers. Various approaches to FCA are also presented (perturbation, Green's function technique)

The geometric and electronic structure of condensed phase organic conducting polymer PEDOT:PSS blends has been investigated by periodic density functional theory (DFT) calculations with a generalized-gradient approximation (GGA) functional, and a plane wave basis set. The influence of the degree of doping of the PEDOT polymer on structural and optical parameters such as the reflectivity, absorbanc

We report on the use of binary mixtures of oppositely charged gold nanoparticles (AuNPs) and spherical polyelectrolyte brushes (SPBs), consisting of a polystyrene core onto which long polystyrene sulfonate chains are grafted, as a simple model system to investigate the influence of directional interactions on self-assembly. We demonstrate that the mixing ratio, i.e., the number of AuNPs per SPB, h

The relation between free-carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free-carrier absorption evolves from the intersubband transitions in the limit of infinite number of wells with vanishing barrier width. It is explicitly shown that the integral of the absorption

Graves' disease (GD) is a complex autoimmune disorder characterized by hyperthyroidism and diffuse goitre. 25-50% of the patients with GD develop eye symptoms, Graves' ophthalmopathy (GO). The overall aim of this thesis was to explore the molecular etiology of GD and GO. By studying gene expression in Studies I, III, and IV, we demonstrated that adipocyte-related immediate early genes (IEGs) incl

Background: The social environment in which children grow up is closely associated with their health. The aim of this study was to investigate the relationship between maternal educational level, parental preventive behavior, parental risk behavior, social support, and use of medical care in small children in Malmo, Sweden. We also wanted to investigate whether potential differences in child medic

We present a theory for a mesoscopic turnstile that produces spatially separated streams of electrons and holes along edge states in the quantum Hall regime. For a broad range of frequencies in the nonadiabatic regime the turnstile operation is found to be ideal, producing one electron and one hole per cycle. The accuracy of the turnstile operation is characterized by the fluctuations of the trans

Two-dimensional spectroscopy has recently revealed the oscillatory behavior of the excitation dynamics of molecular systems. However, in the majority of cases there is considerable debate over what is actually being observed: excitonic or vibrational wavepacket motion or evidence of quantum transport. In this letter we present a method for distinguishing between vibrational and excitonic wavepacke

Addition of surfactants to aqueous solutions of polyelectrolytes carrying an opposite charge causes the spontaneous formation of complexes in the bulk phase in certain concentration ranges. Under some conditions, compact monodisperse multichain complexes are obtained in the bulk. The size of these complexes depends on the mixing procedure and it can be varied in a controlled way from nanometers up

The performance of hybrid solar cells composed of polymer and ZnO is mainly hindered by the defects of ZnO. Here, we investigate the effects of ZnO nanoparticle surface modification with poly(ethylene oxide) (PEO) on the performance of bulk heterojunction hybrid solar cells based on poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and ZnO nanoparticles. The reference device us