In vivo magnetic resonance imaging and spectroscopy of Alzheimer__s disease in transgenic mice

The thesis describes the application of several different magnetic resonance (MR) techniques to study the effects of the progression of disease in a transgenic mouse model of Alzheimer's. Using MR imaging, the amyloid plaque deposition was visualized and the plaque load quantified in the same mice as they aged. Concurrently the transverse relaxation time (T2) was measured in affected brain regions and shown to decrease over time as plaque-load increased. To study the neurochemical profile in the mouse brain brain both one- (1D) and two-dimensional (2D) MR spectroscopic techniques were employed. 1D MRS is widely used in similar research, but has limited spectral resolution. To overcome this limitation, a 2D MRS technique was implemented and optimized for use in mouse brain. This technique, L-COSY, allowed the detection of several metabolites which were not visible using standard 1D MRS techniques. This technique was subsequently used to study the effects of Alzheimer's on the neurochemical profile. Observed changes were correlated with plaque deposition.UBL - phd migration 201

Impedance model for the polarization-dependent optical absorption of superconducting single-photon detectors

We measured the single-photon detection efficiency of NbN superconducting single photon detectors as a function of the polarization state of the incident light for different wavelengths in the range from 488 nm to 1550 nm. The polarization contrast varies from ~5% at 488 nm to ~30% at 1550 nm, in good agreement with numerical calculations. We use an optical-impedance model to describe the absorption for polarization parallel to the wires of the detector. For lossy NbN films, the absorption can be kept constant by keeping the product of layer thickness and filling factor constant. As a consequence, we find that the maximum possible absorption is independent of filling factor. By illuminating the detector through the substrate, an absorption efficiency of ~70% can be reached for a detector on Si or GaAs, without the need for an optical cavity.Comment: 15 pages, 5 figures, submitted to Journal of Applied Physic

Когнітивні структури репрезентації хрематонімійних знань

В запропонованій статті розглядаються основні структури репрезентації хрематонімів в ментальному лексиконі індивіда. Питання побудови моделей та схем організації ментального лексикону привертає велику увагу лінгвістів сьогодні.В предложенной статье рассматриваются основные структуры репрезентации хрематонимов в ментальном лексиконе индивида. Вопрос построения моделей и схем организации ментального лексикона привлекает огромное внимание лингвистов.The article deals with the main representation structures of chrematonyms in the mental lexicon of an individual. The task of model construction and scheme organization of mental lexicon attracts much attention of linguists today

Wnt3a protein reduces growth factor-driven expansion of human hematopoietic stem and progenitor cells in serum-free cultures

Abstract Ex vivo expansion of hematopoietic stem and progenitor cells (HSPC) is a promising approach to improve insufficient engraftment after umbilical cord blood stem cell transplantation (UCB-SCT). Although culturing HSPC with hematopoietic cytokines results in robust proliferation, it is accompanied with extensive differentiation and loss of self-renewal capacity. Wnt signaling has been implicated in regulating HSPC fate decisions in vivo and in promoting HSPC self-renewal by inhibition of differentiation, but the effects of Wnt on the ex vivo expansion of HSPC are controversial. Here, we demonstrate that exogenous Wnt3a protein suppresses rather than promotes the expansion of UCB-derived CD34+ cells in serum free expansion cultures. The reduced expansion was also observed in cultures initiated with LinCD34+ CD38lowCD45RACD90+ cells which are highly enriched in HSC and was also observed in response to activation of beta-catenin signaling by GSK3 inhibition. The presence of Wnt3a protein during the culture reduced the frequency of multilineage CFU-GEMM and the long-term repopulation ability of the expanded HSPC. These data suggest that Wnt signaling reduces expansion of human HSPC in growth factor-driven expansion cultures by promoting differentiation of HSPC

In vivo longitudinal monitoring of blood flow alterations in TG2576 mouse model of Alzheimer's Disease

Solid state NMR/Biophysical Organic Chemistr

In vivo localized two dimensional MR spectroscopy to compare the neurochemical profile in wild-type and transgenic mouse of Alzheimer’s disease

Solid state NMR/Biophysical Organic Chemistr

MRI assessment of blood flow artifacts in a transgenic mouse model of Alzheimer’s disease

Solid state NMR/Biophysical Organic Chemistr

Longitudinal assessment of Alzheimer's beta-amyloid plaquedevelopment in transgenic mice monitored by in vivo magnetic resonance microimaging

Solid state NMR/Biophysical Organic Chemistr