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Willem de Haan Yolande AL Pijnenburg Rob LM Strijers Yolande van der Made Wiesje M van der Flier Philip Scheltens Cornelis J Stam 《BMC neuroscience》2009,10(1):101-12
Background
Although a large body of knowledge about both brain structure and function has been gathered over the last decades, we still have a poor understanding of their exact relationship. Graph theory provides a method to study the relation between network structure and function, and its application to neuroscientific data is an emerging research field. We investigated topological changes in large-scale functional brain networks in patients with Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD) by means of graph theoretical analysis of resting-state EEG recordings. EEGs of 20 patients with mild to moderate AD, 15 FTLD patients, and 23 non-demented individuals were recorded in an eyes-closed resting-state. The synchronization likelihood (SL), a measure of functional connectivity, was calculated for each sensor pair in 0.5–4 Hz, 4–8 Hz, 8–10 Hz, 10–13 Hz, 13–30 Hz and 30–45 Hz frequency bands. The resulting connectivity matrices were converted to unweighted graphs, whose structure was characterized with several measures: mean clustering coefficient (local connectivity), characteristic path length (global connectivity) and degree correlation (network 'assortativity'). All results were normalized for network size and compared with random control networks. 相似文献85.
We investigate the assignment of electronic transitions in alkyl peroxy radicals. Past experimental work has shown that the phenyl peroxy radical exhibits a transition in the visible region; however, previous high level calculations have not reproduced this observed absorption. We use time dependent density functional theory (TDDFT) to characterize the electronic excitations of the phenyl peroxy radical as well as other hydrocarbon substituted peroxy radicals. TDDFT calculations of the phenyl peroxy radical support an excitation in the visible spectrum. Further, we investigate the nature of this visible absorption using electron attachment/detachment density diagrams of the peroxy radicals and present a qualitative picture of the origin of the visible absorption based on molecular orbital perturbations. The peroxy radical substituent is also compared against isoelectronic radical groups. The visible absorption is determined to be dependent on mixing of the alkyl and radical substituent orbitals. 相似文献
86.
Manoj Kumar AL. Ramanathan Abhijit Mukherjee Ravi Sawlani Shyam Ranjan 《Isotopes in environmental and health studies》2019,55(3):254-271
Stable isotopes of water (δ2H, δ18O) and δ13CTIC were used as a tool to trace the recharge processes, natural carbon (organic and inorganic) source and dynamics in the aquifers of the central Gangetic basin, India. Stable isotope (δ2H, δ18O) record of groundwater (n?=?105) revealed that the groundwater of Piedmont was recharged by meteoric origin before evaporation, while aquifers of the older and younger alluvium were recharged by water that had undergone evaporation loss. River Ganges and its tributaries passing through this area have very little contribution in recharging while ponds play no role in the recharging of adjacent aquifers. The connectivity of shallow aquifers of aquitard formation (comprised of clay/sandy clay with thin patches of fine grey sand), i.e. 25–60?m below ground level (bgl) with the main upper aquifer (at a depth of >120?m?bgl) was found to be higher in older and younger alluvium. Negative values of δ13CTIC (median ?9.6 ‰; range ?13.2 to ?5.4 ‰) and high TIC (median 35?mM; range 31–46?mM) coupled with low TOC (median 1.35?mg/L; range 0.99–1.77?mg/L) indicated acceleration in microbial activity in the younger alluvium, especially in the active floodplain of river Ganges and its proximity. 相似文献
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A standard model is suggested to explore correlation features of two spatially separated optomechanical cavities. The cavities are coupled through the photon-hopping process. In particular, we investigate the generation of entanglement between mechanical resonators in the strong coupling regime and the two cavities are assumed to be driven by a coherent laser field. In order to quantify entanglement we use the logarithmic negativity. The analytical solutions are presented for the system in a parameter regime very close to the current experimental results. We show that in the presence of the photon hopping process between the cavities, the two mechanical resonators and the field modes can be entangled. This shows clearly that the entanglement can be transfer via radiation pressure of a photon hopping coupling from the intracavity photon-phonon entanglements to an inter-cavity photon-photon or phonon-phonon entanglement. 相似文献
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A?Pires M?Nelson AL?Pozniak M?Fisher B?Gazzard F?Gotch N?ImamiEmail author 《Journal of immune based therapies and vaccines》2005,3(1):7
Background
With the advent of antiretroviral therapy (ART) cases of immune reconstitution inflammatory syndrome (IRIS) have increasingly been reported. IRIS usually occurs in individuals with a rapidly rising CD4 T-cell count or percentage upon initiation of ART, who develop a deregulated immune response to infection with or without reactivation of opportunistic organisms. Here, we evaluated rises in absolute CD4 T-cells, and specific CD4 T-cell responses in 4 HIV-1+ individuals presenting with mycobacterial associated IRIS who received in conjunction with ART, IL-2 plus GM-CSF immunotherapy. 相似文献90.
The new experimental method of vibronically selective ground-state recovery probing has been used to study relaxation processes that follow S1 ← 相似文献