221 research outputs found
APRESENTAÇÃO
Temas centrais na historiografia africanista, o domínio político, a escravidão e o trabalho forçado são abordados nesse dossiê a partir da reação dos africanos ao modo como esses fenômenos ocorreram em Angola, Moçambique e no Congo. Os artigos resultam de apresentações realizadas durante o Seminário Internacional Cultura, Política e Trabalho na África Meridional, que teve lugar na Universidade Estadual de Campinas - UNICAMP (Brasil), entre 11 e 14 de maio de 2015, promovido pelo Centro de Pes..
Evaluating the Performance of Ultra-Low-Field MRI for In-vivo 3D Current Density Imaging of the Human Head
Magnetic fields associated with currents flowing in tissue can be measured
non-invasively by means of zero-field-encoded ultra-low-field magnetic
resonance imaging (ULF MRI) enabling current density imaging (CDI) and possibly
conductivity mapping of human head tissues. Since currents applied to a human
are limited by safety regulations and only a small fraction of the current
passes through the relatively high-resistive skull, a sufficient
signal-to-noise ratio (SNR) may be difficult to obtain when using this method.
In this work, we study the relationship between the image SNR and the SNR of
the field reconstructions from zero-field-encoded data. We evaluate these
results for two existing ULF MRI scanners, one ultra-sensitive single-channel
system and one whole-head multi-channel system, by simulating sequences
necessary for current-density reconstruction. We also derive realistic
current-density and magnetic-field estimates from finite-element-method
simulations based on a three-compartment head model. We found that existing
ULF-MRI systems reach sufficient SNR to detect intra-cranial current
distributions with statistical uncertainty below 10%. However, they also reveal
that image artifacts influence the reconstruction quality. Further, our
simulations indicate that current-density reconstruction in the scalp requires
a resolution less than 5 mm and demonstrate that the necessary sensitivity
coverage can be accomplished by multi-channel devices.Comment: 18 pages, 8 figures. This project has received funding from the
European Union's Horizon 2020 research and innovation programme under grant
agreement No 68686
Willingness and Ability of Older Adults in the Emergency Department to Provide Clinical Information Using a Tablet Computer
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134983/1/jgs14366.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134983/2/jgs14366_am.pd
Optical properties of silicon-implanted polycrystalline diamond membranes
We investigate the optical properties of polycrystalline diamond membranes
containing silicon-vacancy (SiV) color centers in combination with other
nano-analytical techniques. We analyze the correlation between the Raman
signal, the SiV emission, and the background luminescence in the crystalline
grains and in the grain boundaries, identifying conditions for the
addressability of single SiV centers. Moreover, we perform a scanning
transmission electron microscopy (STEM) analysis, which associates the
microscopic structure of the membranes and the evolution of the diamond crystal
along the growth direction with the photoluminescence properties, as well as a
time-of-flight secondary ion mass spectrometry (ToF-SIMS) to address the
distribution of silicon in implanted and un-implanted membranes. The results of
the STEM and ToF-SIMS studies are consistent with the outcome of the optical
measurements and provide useful insight into the preparation of polycrystalline
samples for quantum nano-optics.Comment: 21 pages, 8 figure
A Prospective Evaluation of Shared Decision-making Regarding Analgesics Selection for Older Emergency Department Patients With Acute Musculoskeletal Pain
Musculoskeletal pain is a common reason for emergency department (ED) visit by older adults. Outpatient pain management following ED visits in this population is challenging as a result of contraindications to, and side effects from, available therapies. Shared decision-making (SDM) between patients and emergency physicians may improve patient experiences and health outcomes. Among older ED patients with acute musculoskeletal pain, we sought to characterize their desire for involvement in the selection of outpatient analgesics. We also sought to assess the impact of SDM on change in pain at 1 week, patient satisfaction, and side effects
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