940 research outputs found
Group sparse dictionary learning and inference for resting-state fMRI analysis of Alzheimer'S disease
A novel group analysis tool for data-driven resting state fMRI analysis using group sparse dictionary learning and mixed model is presented along with the promising indica-tions of Alzheimer’s disease progression. Instead of using independency assumption as in popular ICA approaches, the proposed approach is based on the sparse graph assumption such that a temporal dynamics at each voxel position is a sparse combination of global brain dynamics. In estimating the unknown global dynamics and local network structures, we perform sparse dictionary learning for the concatenated temporal data across the subjects by constraining that the network structures within a group are similar. Under the homoscedasticity variance assumption across subjects and groups, we show that the mixed model group inference can be easily performed using second level GLM with summary statistics. Using extensive resting fMRI data set obtaine
Observation of transverse spin Nernst magnetoresistance induced by thermal spin current in ferromagnet/non-magnet bilayers
Electric generation of spin current via spin Hall effect is of great interest
as it allows an efficient manipulation of magnetization in spintronic devices.
Theoretically, spin current can be also created by a temperature gradient,
which is known as spin Nernst effect. Here, we report spin Nernst
effect-induced transverse magnetoresistance in ferromagnet (FM)/non-magnetic
heavy metal (HM) bilayers. We observe that the magnitude of transverse
magnetoresistance (i.e., planar Nernst signal) in FM/HM bilayers is
significantly modified by HM and its thickness. This strong dependence of
transverse magnetoresistance on HM evidences the spin Nernst effect in HM; the
generation of thermally-induced spin current in HM and its subsequent
reflection at the FM/HM interface. Our analysis of transverse magnetoresistance
shows that the spin Nernst angles of W and Pt have the opposite sign to their
spin Hall angles. Moreover, our estimate implies that the magnitude of the spin
Nernst angle would be comparable to that of the spin Hall angle, suggesting an
efficient generation of spin current by the spin Nernst effect
Anti-Inflammatory Effects of Bangpungtongsung-San, a Traditional Herbal Prescription
Bangpungtongsung-san (BPTS), a traditional oriental herbal prescription, is widely used for expelling wind, draining heat, and providing general improvement to the immune system. In this study, we investigated the effects of BPTS on induction of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), proinflammatory cytokines, nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinases (MAPKs) in lipopolysaccharide- (LPS- ) stimulated Raw 264.7 cells, and on paw edema in rats. At concentrations of 0.5, 0.75, and 1 mg/mL, treatment with BPTS inhibited levels of expression of LPS-induced NF-κB and MAPKs (ERK, JNK, and p38) as well as production of proinflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) by LPS. These results suggest that BPTS may exert anti-inflammatory effects via reduction of proinflammatory mediators, including NO, PGE2, TNF-α, and IL-6 through suppression of the signaling pathways of NF-κB and MAPKs in LPS-induced macrophages. In addition, using the carrageenan-induced paw edema assay, an antiedema effect of BPTS was observed in rats. These findings may provide scientific evidence validating the use of BPTS in treatment of patients with heat syndrome in Korean oriental medicine
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