565 research outputs found
Dynamic gas temperature measurement system. Volume 2: Operation and program manual
The hot section technology (HOST) dynamic gas temperature measurement system computer program acquires data from two type B thermocouples of different diameters. The analysis method determines the in situ value of an aerodynamic parameter T, containing the heat transfer coefficient from the transfer function of the two thermocouples. This aerodynamic parameter is used to compute a fequency response spectrum and compensate the dynamic portion of the signal of the smaller thermocouple. The calculations for the aerodynamic parameter and the data compensation technique are discussed. Compensated data are presented in either the time or frequency domain, time domain data as dynamic temperature vs time, or frequency domain data
Comparative absorption of curcumin formulations
BACKGROUND: The potential health benefits of curcumin are limited by its poor solubility, low absorption from the gut, rapid metabolism and rapid systemic elimination. The purpose of this study was the comparative measurement of the increases in levels of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and the metabolite tetrahydrocurcumin after oral administration of three different curcumin formulations in comparison to unformulated standard. METHODS: The relative absorption of a curcumin phytosome formulation (CP), a formulation with volatile oils of turmeric rhizome (CTR) and a formulation of curcumin with a combination of hydrophilic carrier, cellulosic derivatives and natural antioxidants (CHC) in comparison to a standardized curcumin mixture (CS) was investigated in a randomized, double-blind, crossover human study in healthy volunteers. Samples were analyzed by HPLC-MS/MS. RESULTS: Total curcuminoids appearance in the blood was 1.3-fold higher for CTR and 7.9-fold higher for CP in comparison to unformulated CS. CHC showed a 45.9-fold higher absorption over CS and significantly improved absorption over CP (5.8-fold) and CTR (34.9-fold, all p < 0.001). CONCLUSION: A formulation of curcumin with a combination of hydrophilic carrier, cellulosic derivatives and natural antioxidants significantly increases curcuminoid appearance in the blood in comparison to unformulated standard curcumin CS, CTR and CP
Transient electrical coupling regulates formation of neuronal networks
Introduction Electrical coupling is widespread in invertebrate nervous systems as well as in the developing mammalian brain. Neurons functionally coupled by electrical synapses possess coordinated patterns of spontaneous activity and changes in intracellular calcium concentratio
Perfusion MR Imaging in Differentiating High-Grade from Low-Grade Gliomas
To correlate perfusion MR imaging with histologic grade of cerebral gliomas.
Materials & Methods
Relative cerebral blood volume (rCBV) maps were determined in 22 patients with
pathologically proved gliomas (11 glioblastomas, 8 anaplastic gliomas and 2 low-grade
gliomas) by dynamic contrast-enhanced T2*-weighted MR imaging. MR examination
was completed with conventional T1- and T2-weighted imaging. The rCBV maps were
calculated with an independent workstation by fitting a gamma-variate function to the
contrast material concentration versus time curve. Relative CBV ratios obtained between
tumor and normal white matter were compared between glioblastomas, anaplastic
gliomas and low-grade gliomas by means of receiver operating characteristic (ROC)
analysis.
Results
Mean rCBV ratios were 4.85 (\ub1 1) for glioblastomas, 3.87 (\ub1 0.7) for anaplastic gliomas
and 1.65 (\ub1 1.6) for low-grade gliomas. Receiver operating characteristic analysis
demonstrates significant differences between glioblastomas and anaplastic gliomas
(p<.05), between anaplastic gliomas and low-grade gliomas (p<.05) and between
glioblastomas and low-grade gliomas (p<.01). The rCBV ratio cutoff value between highgrade
gliomas and low-grade gliomas was 2.52 with a sensitivity and specificity of 100%
and 75% respectively.
Conclusion
Perfusion MR imaging is a reliable technique for differentiating high-grade from low-grade
glioma
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Can tDCS enhance treatment of aphasia after stroke?
Background: Recent advances in the application of transcranial direct current stimulation (tDCS) in healthy populations have led to the exploration of the technique as an adjuvant method to traditional speech therapies in patients with post-stroke aphasia.
Aims: The purpose of the review is: (i) to review the features of tDCS that make it an attractive tool for research and potential future use in clinical contexts; (ii) to describe recent studies exploring the facilitation of language performance using tDCS in post-stroke aphasia; (iii) to explore methodological considerations of tDCS that may be key to understanding tDCS in treatment of aphasia post stroke; and (iv) to highlight several caveats and outstanding questions that need to be addressed in future work.
Main Contribution: This review aims to highlight our current understanding of the methodological and theoretical issues surrounding the use of tDCS as an adjuvant tool in the treatment of language difficulties after stroke.
Conclusions: Preliminary evidence shows that tDCS may be a useful tool to complement treatment of aphasia, particularly for speech production in chronic stroke patients. To build on this exciting work, further systematic research is needed to understand the mechanisms of tDCS-induced effects, its application to current models of aphasia recovery, and the complex interactions between different stimulation parameters and language rehabilitation techniques. The potential of tDCS is to optimise language rehabilitation techniques and promote long-term recovery of language. A stimulating future for aphasia rehabilitation
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