Dimension-Dependent Phenomenological Model of Excitonic Electric Dipole in InGaAs Quantum Dots.

Permanent electric dipole is a key property for effective control of semiconductor quantum-dot-based sources of quantum light. For theoretical prediction of that, complex geometry-dependent quantum simulations are necessary. Here, we use k·p simulations of exciton transition in InGaAs quantum dots to derive a simple geometry-dependent analytical model of dipole.

Structural and compositional analysis of (InGa)(AsSb)/GaAs/GaP Stranski-Krastanov quantum dots.

We investigated metal-organic vapor phase epitaxy grown (InGa)(AsSb)/GaAs/GaP Stranski-Krastanov quantum dots (QDs) with potential applications in QD-Flash memories by cross-sectional scanning tunneling microscopy (X-STM) and atom probe tomography (APT). The combination of X-STM and APT is a very powerful approach to study semiconductor heterostructures with atomic resolution, which provides detailed structural and compositional information on the system. The rather small QDs are found to be of truncated pyramid shape with a very small top facet and occur in our sample with a very high density of ∼4 × 10 cm.

Artificial Coherent States of Light by Multiphoton Interference in a Single-Photon Stream.

Coherent optical states consist of a quantum superposition of different photon number (Fock) states, but because they do not form an orthogonal basis, no photon number states can be obtained from it by linear optics. Here we demonstrate the reverse, by manipulating a random continuous single-photon stream using quantum interference in an optical Sagnac loop, we create engineered quantum states of light with tunable photon statistics, including approximate weak coherent states. We demonstrate this experimentally using a true single-photon stream produced by a semiconductor quantum dot in an optical microcavity, and show that we can obtain light with g^{(2)}(0)→1 in agreement with our theory, which can only be explained by quantum interference of at least 3 photons.

Automated Knee Osteoarthritis Assessment Increases Physicians' Agreement Rate and Accuracy: Data from the Osteoarthritis Initiative.

. To assess the impact of a computerized system on physicians' accuracy and agreement rate, as compared with unaided diagnosis. .

Excitonic structure and pumping power dependent emission blue-shift of type-II quantum dots.

In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction ap- proach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement.

The relation of iron status and hemochromatosis gene mutations in patients with chronic hepatitis C.

Background & Aims: Elevated hepatic iron concentration may affect the response to antiviral therapy in chronic hepatitis C. This study explored the contribution of genetic hemochromatosis to iron accumulation in chronic hepatitis C.

Methods: HFE mutations (C282Y and H63D) were assessed in 184 patients with chronic hepatitis C virus and 487 controls.

Role of tryptophan in the elevated serotonin-turnover in hepatic encephalopathy.

The increase of the brain levels of 5-hydroxyindoleacetic acid (5-HIAA) in hepatic encephalopathy (HE) suggests an increased turnover of serotonin (5-HT). To study the role of tryptophan on the increased brain 5-HT metabolism in HE, we attempted to monitor brain levels of tryptophan in rats with thioacetamide-induced acute liver failure by intravenous infusion of branched-chain amino acids (BCAA). The effect of this treatment on 5-HT synthesis and metabolism was investigated in five brain areas.

M3/M21 serum levels in women with adnexal masses and inflammatory diseases.

The aim of the present study was to evaluate the clinical usefulness of the cytokeratin tumor marker M3/M21 as a screening marker for ovarian cancer, as a predictive marker in patients with adnexal masses and as a prognostic factor in women with ovarian cancer. To determine the specificity of the M3/M21 test, we investigated M3/M21 serum levels in several benign conditions. This retrospective study comprises 37 patients with ovarian cancer FIGO stages Ia to III.

Liver biopsy is a useful predictor of response to interferon therapy in chronic hepatitis C.

Aim: To evaluate the usefulness of easily assessable morphological parameters in liver biopsies in order to predict efficacy of interferon-alpha (IFN) treatment in patients with chronic hepatitis C.

Methods And Results: Inflammatory activity and fibrosis (according to Scheuer), and the hepatic iron content (according to Rowe and DiBisceglie) were assessed in pre-treatment liver biopsies of 73 de novo patients with chronic hepatitis C. Furthermore the presence of fat, lymphoid aggregates, and bile duct lesions was evaluated.

[Changes in the 24-hour rhythm of plasma melatonin in patients with liver cirrhosis--relation to sleep architecture].

Objective: To assess the 24 hr plasma melatonin profile as a marker of the output rhythm from the circadian clock and to study sleep diaries as reflection of subjective sleep quality in patients with liver cirrhosis.

Design: Prospective cohort study.

Patients: A total of 14 subjects, 7 non-alcoholic cirrhotics and 7 age-, sex-, and educationally-matched controls.

Wilson's disease in patients presenting with liver disease: a diagnostic challenge.

Background & Aims: In patients with Wilson's disease presenting with liver involvement, the correct diagnosis is often missed or delayed. The aim of this study was to find an algorithm for diagnosis of this difficult patient group.

Methods: Clinical and laboratory findings of 55 patients with Wilson's disease were evaluated at diagnosis before treatment.

A low-protein diet ameliorates disrupted diurnal locomotor activity in rats after portacaval anastomosis.

In previous studies we noted a disruption of the circadian locomotor activity rhythm in rats after portacaval anastomosis (PCA). To examine whether this abnormality is related to factors that aggravate hepatic encephalopathy in humans, we studied the effect of dietary formulation and protein content on body weight, locomotor activity, and entrainment to the light-dark cycle in rats after PCA or sham operation. Postoperative weight loss was prevented by pair-feeding with a purified liquid diet.

Modulation of hepatic encephalopathy in rats with thioacetamide-induced acute liver failure by serotonin antagonists.

Objective: Accumulated neurochemical data in different animal models of fulminant hepatic failure and in humans with hepatic encephalopathy suggest that serotoninergic tone is increased in the brain in hepatic encephalopathy. Since neurochemical alterations may not have behavioural or electrophysiological consequences the contribution of the serotoninergic system to the pathogenesis of hepatic encephalopathy was explored.

Methods: The effects of drugs modulating serotoninergic neurotransmission, the nonselective serotonin receptor antagonist methysergide and the serotonin2 receptor antagonist seganserin were tested neuropharmacologically in thioacetamide-induced acute liver failure in rats.

Diagnosis of Wilson's disease in an asymptomatic sibling by DNA linkage analysis.

The molecular genetic diagnosis of Wilson's disease in the 5-year-old sister of a patient with Wilson's disease is reported. The girl was clinically free of disease and had no conventional biochemical markers of Wilson's disease (i.e.

Disruption of circadian locomotor activity in rats after portacaval anastomosis is not gender dependent.

A recent study suggested that female rats are less affected by a portacaval anastomosis (PCA) than their male counterparts, as measured by body weight and changes in locomotor activity. In this study, we evaluated the entrainment of locomotor activity to the light/dark (LD) cycle, a consistent abnormality in the portacaval shunted rat. The degree of entrainment was measured in male and female rats before and after PCA or sham operation.

Disruption of the diurnal rhythm of plasma melatonin in cirrhosis.

Objectives: To assess 24-hour plasma melatonin profile as a marker of output rhythm from the circadian clock and to study sleep diaries as reflections of subjective sleep quality in patients with liver cirrhosis.

Design: Prospective cohort study.

Setting: Clinical research center in a university hospital.

Hepatic encephalopathy in rats with thioacetamide-induced acute liver failure is not mediated by endogenous benzodiazepines.

Background: To distinguish whether the improvement of hepatic encephalopathy by benzodiazepine receptor antagonists is mediated by their antagonistic or their inverse agonistic properties, the neurobehavioral effects of a variety of benzodiazepine receptor ligands in rats with thioacetamide-induced acute liver failure were tested.

Methods: The neural inhibitory effect of the benzodiazepine agonist flunitrazepam and its reversibility by the "pure" antagonist Ro 14-7437 were examined in thioacetamide-treated rats and controls. The effects of Ro 14-7437, of the partial inverse agonist Ro 15-4513, and the inverse agonist DMCM in rats with hepatic encephalopathy grade II/III were tested.

Beneficial effect of pharmacological modulation of the GABAA-benzodiazepine receptor on hepatic encephalopathy in the rat: comparison with uremic encephalopathy.

Hepatic encephalopathy is ameliorated by drugs acting on the central GABAA-benzodiazepine receptor complex. To investigate whether these effects are specific for hepatic encephalopathy or just reflect a nonspecific arousal reaction, various benzodiazepine antagonists like flumazenil or with inverse agonistic properties (Ro 15-4513, Ro 15-3505) were studied in uremic encephalopathy in rats after bilateral ureteral ligation (n = 20) and compared with hepatic encephalopathy caused by thioacetamide-induced acute liver failure (n = 33). As soon as the animals developed clear signs of metabolic encephalopathy, their motor activity was recorded in an animal activity meter for 10 min.

Increased serotoninergic and noradrenergic activity in hepatic encephalopathy in rats with thioacetamide-induced acute liver failure.

Functional changes of various neurotransmitter systems have been implicated in the pathogenesis of hepatic encephalopathy. In this study the role of brain monoaminergic neurotransmitter systems in hepatic encephalopathy was investigated in rats with thioacetamide-induced acute liver failure. Concentrations of serotonin, dopamine, noradrenaline and of their metabolites 5-hydroxyindoleacetic acid, dihydroxyphenylalanine (following inhibition of dihydroxyphenylalanine-decarboxylase), dihydroxyphenylacetic acid, homovanillic acid and 3-methoxy-4-hydroxyphenyl-glycol, were measured in the cerebral cortex, striatum and hippocampus by high performance liquid chromatography with electrochemical detection.