A novel method for classifying cortical state to identify the accompanying changes in cerebral hemodynamics

Background: Many brain imaging techniques interpret the haemodynamic response as an indirect indicator of underlying neural activity. However, a challenge when interpreting this blood based signal is how changes in brain state may affect both baseline and stimulus evoked haemodynamics. New method: We developed an Automatic Brain State Classifier (ABSC), validated on data from anaesthetised rodents. It uses vectorised information obtained from the windowed spectral frequency power of the Local Field Potential. Current state is then classified by comparing this vectorised information against that calculated from state specific training datasets. Results: The ABSC identified two user defined brain states (synchronised and desynchronised), with high accuracy (~90%). Baseline haemodynamics were found to be significantly different in the two identified states. During state defined periods of elevated baseline haemodynamics we found significant decreases in evoked haemodynamic responses to somatosensory stimuli. Comparison to existing methods: State classification - The ABSC (~90%) demonstrated greater accuracy than clustering (~66%) or 'power threshold' (~64%) methods of comparison.Haemodynamic averaging - Our novel approach of selectively averaging stimulus evoked haemodynamic trials by brain state yields higher quality data than creating a single average from all trials. Conclusions: The ABSC can account for some of the commonly observed trial-to-trial variability in haemodynamic responses which arises from changes in cortical state. This variability might otherwise be incorrectly attributed to alternative interpretations. A greater understanding of the effects of cortical state on haemodynamic changes could be used to inform techniques such as general linear modelling (GLM), commonly used in fMRI

Ruxolitinib for Glucocorticoid-Refractory Acute Graft-versus-Host Disease

BACKGROUND: Acute graft-versus-host disease (GVHD) remains a major limitation of allogeneic stem-cell transplantation; not all patients have a response to standard glucocorticoid treatment. In a phase 2 trial, ruxolitinib, a selective Janus kinase (JAK1 and JAK2) inhibitor, showed potential efficacy in patients with glucocorticoid-refractory acute GVHD. METHODS: We conducted a multicenter, randomized, open-label, phase 3 trial comparing the efficacy and safety of oral ruxolitinib (10 mg twice daily) with the investigator's choice of therapy from a list of nine commonly used options (control) in patients 12 years of age or older who had glucocorticoid-refractory acute GVHD after allogeneic stem-cell transplantation. The primary end point was overall response (complete response or partial response) at day 28. The key secondary end point was durable overall response at day 56. RESULTS: A total of 309 patients underwent randomization; 154 patients were assigned to the ruxolitinib group and 155 to the control group. Overall response at day 28 was higher in the ruxolitinib group than in the control group (62% [96 patients] vs. 39% [61]; odds ratio, 2.64; 95% confidence interval [CI], 1.65 to 4.22; P<0.001). Durable overall response at day 56 was higher in the ruxolitinib group than in the control group (40% [61 patients] vs. 22% [34]; odds ratio, 2.38; 95% CI, 1.43 to 3.94; P<0.001). The estimated cumulative incidence of loss of response at 6 months was 10% in the ruxolitinib group and 39% in the control group. The median failure-free survival was considerably longer with ruxolitinib than with control (5.0 months vs. 1.0 month; hazard ratio for relapse or progression of hematologic disease, non-relapse-related death, or addition of new systemic therapy for acute GVHD, 0.46; 95% CI, 0.35 to 0.60). The median overall survival was 11.1 months in the ruxolitinib group and 6.5 months in the control group (hazard ratio for death, 0.83; 95% CI, 0.60 to 1.15). The most common adverse events up to day 28 were thrombocytopenia (in 50 of 152 patients [33%] in the ruxolitinib group and 27 of 150 [18%] in the control group), anemia (in 46 [30%] and 42 [28%], respectively), and cytomegalovirus infection (in 39 [26%] and 31 [21%]). CONCLUSIONS: Ruxolitinib therapy led to significant improvements in efficacy outcomes, with a higher incidence of thrombocytopenia, the most frequent toxic effect, than that observed with control therapy

Microwire (Mg,Zn)O/ZnO and (Mg,Zn)O/(Cd,Zn)O non-polar quantum well heterostructures for cavity applications

Pulsed-laser deposited, non-polar MgxZn1-xO/ZnO and MgxZn1-xO/Zn1-yCdyO quantum well heterostructures were fabricated in radial direction on ZnO microwires with well-defined hexagonal cross section. Optical resonances modulate room-temperature luminescence spectra for all fabricated heterostructures demonstrating their applicability as microcavities. Quantum confinement was proven by time-integrated and time-resolved luminescence. The ZnO quantum well emission was tuned between 3.76 and 3.35eV by adjusting the well thickness and barrier composition. In order to further reduce the QW emission energy, active Zn1-yCdyO quantum wells in MgxZn1-xO barriers were grown emitting between 3.07 and 2.70eV for different well thicknesses but fixed barrier composition. (C) 2012 American Institute of Physics. [doi:10.1063/1.3678594]</p

Entwicklung von und Untersuchung an gradierten Grenzschichten Titanoxid/Hydroxylapatit/Kollagen Abschlussbericht

Available from TIB Hannover: F99B574+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDeutsche Forschungsgemeinschaft (DFG), Bonn (Germany)DEGerman

Exciton localization and phonon sidebands in polar ZnO/MgZnO quantum wells

Exciton localization is studied for polar ZnO/Mg0.27Zn0.73O quantum wells (QWs) grown by pulsed laser deposition. The samples exhibit both quantum confinement as well as the quantum-confined Stark effect. Emission energies between 3.46 and 3.18 eV, depending on the QW thickness, are observed in wedge-shaped samples. Intense QW-phonon sidebands are observed as a result of a strong exciton-phonon interaction and the localization of excitons. To calculate the Huang-Rhys factor S correctly, the concept of strongly and weakly localized excitons is applied. With increasing QW thickness from 3 to 9 nm, a decrease of S from 0.67 to 0.43 and an increase of the fraction of strongly localized excitons from 0.2 to 0.63 is observed. The decrease of S is explained by a strong increase of the in-plane pseudo-Bohr radius, whereas the increase of the fraction of strongly localized excitons is expected to result from the increasing strength of localization due to the internal electric field. In this regard, a theory based on an effective mass approximation is applied in calculations to determine the shape of the excitons under the appearance of an internal electric field.</p