Cerebral Metabolic Differences Associated with Cognitive Impairment in Parkinson’s Disease

<div><p>Purpose</p><p>To characterize cerebral glucose metabolism associated with different cognitive states in Parkinson’s disease (PD) using ¹⁸F-fluorodeoxyglucose (FDG) and Positron Emission Tomography (PET).</p><p>Methods</p><p>Three groups of patients were recruited in this study including PD patients with dementia (PDD; n = 10), with mild cognitive impairment (PD-MCI; n = 20), and with no cognitive impairment (PD-NC; n = 30). The groups were matched for age, sex, education, disease duration, motor disability, levodopa equivalent dose and Geriatric Depression Rating Scale (GDS) score. All subjects underwent a FDG-PET study. Maps of regional metabolism in the three groups were compared using statistical parametric mapping (SPM5).</p><p>Results</p><p>PD-MCI patients exhibited limited areas of hypometabolism in the frontal, temporal and parahippocampal gyrus compared with the PD-NC patients (p < 0.01). PDD patients had bilateral areas of hypometabolism in the frontal and posterior parietal-occipital lobes compared with PD-MCI patients (p < 0.01), and exhibited greater metabolic reductions in comparison with PD-NC patients (p < 0.01).</p><p>Conclusions</p><p>Compared with PD-NC patients, hypometabolism was much higher in the PDD patients than in PD-MCI patients, mainly in the posterior cortical areas. The result might suggest an association between posterior cortical hypometabolism and more severe cognitive impairment. PD-MCI might be important for early targeted therapeutic intervention and disease modification.</p></div

Brain regions with significant metabolic differences between PD groups (p<0.01 uncorrected).

<p>Brain regions with significant metabolic differences between PD groups (p<0.01 uncorrected).</p

Neuropsychological testing in Parkinson’s disease patients.

<p>Neuropsychological testing in Parkinson’s disease patients.</p

Demographic and clinical profiles of subjects.

<p>Demographic and clinical profiles of subjects.</p

Ordered Porous Pd Octahedra Covered with Monolayer Ru Atoms

Monolayer Ru atoms covered highly ordered porous Pd octahedra have been synthesized via the underpotential deposition and thermodynamic control. Shape evolution from concave nanocube to octahedron with six hollow cavities was observed. Using aberration-corrected high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, we provide quantitative evidence to prove that only a monolayer of Ru atoms was deposited on the surface of porous Pd octahedra. The as-prepared monolayer Ru atoms covered Pd nanostructures exhibited excellent catalytic property in terms of semihydrogenation of alkynes

Atomically Dispersed Ru on Ultrathin Pd Nanoribbons

We report a one-pot synthesis of atomically dispersed Ru on ultrathin Pd nanoribbons. By using synchrotron radiation photoemission spectroscopy (SRPES) and extended X-ray absorption fine structure (EXAFS) measurements in combination with aberration corrected high-resolution transmission electron microscopy (HRTEM), we show that atomically dispersed Ru with content up to 5.9% was on the surface of the ultrathin nanoribbon. Furthermore, the ultrathin Pd/Ru nanoribbons could remarkably prohibit the hydrogenolysis in chemoselective hydrogenation of CC bonds, leading to an excellent catalytic selectivity compared with commercial Pd/C and Ru/C