31 research outputs found
Incidental Subcortical Lesions Identified on Magnetic Resonance Imaging in the Elderly. I. Correlation With Age and Cerebrovascular Risk Factors
Patchy subcortical foci of increased signal intensity are frequently identified on magnetic resonance imaging (MRI) in the elderly. The incidence and clinical correlates of these lesions remain unknown. In this report, 240 consecutive MRI scans performed over a 6-month period were reviewed (excluding patients with recent brain trauma or known demyelinating disease). Subcortical incidental lesions (ILs) were identified, which could not be accounted for by the patient’s current clinical diagnosis, neurological status, or CT scan. The ILs were graded according to size, multiplicity, and location. The incidence and severity of ILs increased with advancing age (p \u3c 0.0005). Among patients over 50 years of age, the incidence and severity of ILs were correlated with a previous history of ischemic cerebrovascular disease (p \u3c 0.05) and with hypertension (p \u3c 0.05). Multivariable regression analysis identified age, prior brain ischemia, and hypertension as the major predictors of ILs in the elderly. Diabetes, coronary artery diseases, and sex did not play a significant role. With the exception of cerebrovascular disease, there was no association between ILs and any particular clinical entity, including dementia. It is concluded that subcorti-cal parenchyma! lesions are frequent incidental findings on MRI in the elderly, and may represent an index of chronic cerebrovascular diseases in such patients. © 1986 American Heart Association, Inc
Surgical Treatment of an Abscess in a Rathke\u27s Cleft Cyst
An abscess in a Rathke\u27s cleft cyst was surgically treated in a 39-year-old man. The patient presented with headaches, fever, and visual deficits. Transcranial decompression of the optic chiasm was carried out first. The abscess recurred, however, and drainage of the abscess and removal of its wall via the transsphenoidal route was carried out 4 weeks later. Visual evoked responses were useful in the successful management of this lesion. The patient regained normal pituitary function and visual function after the operation. © 1983
High-yield production of graphene by liquid-phase exfoliation of graphite
Fully exploiting the properties of graphene will require a method for the mass production of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to ~0.01 mg m1-1, produced by dispersion and exfoliation of graphite in organic solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent -graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of ~1 wt%, which could potentially be improved to 7–12 wt% with further processing. The absence of defects or oxides is confirmed by X-ray photoelectron, infrared and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Solution processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liquid-phase chemistry
Binding of Copper and Cisplatin to Atox1 Is Mediated by Glutathione through the Formation of Metal–Sulfur Clusters
Copper is an essential
nutrient required for many biological processes
involved in primary metabolism, but free copper is toxic due to its
ability to catalyze formation of free radicals. To prevent toxic effects,
in the cell copper is bound to proteins and low molecular weight compounds,
such as glutathione, at all times. The widely used chemotherapy agent
cisplatin is known to bind to copper-transporting proteins, including
copper chaperone Atox1. Cisplatin interactions with Atox1 and other
copper transporters are linked to cancer resistance to platinum-based
chemotherapy. Here we analyze the binding of copper and cisplatin
to Atox1 in the presence of glutathione under redox conditions that
mimic intracellular environment. We show that copper(I) and glutathione
form large polymers with a molecular mass of approximately 8 kDa,
which can transfer copper to Atox1. Cisplatin also can form polymers
with glutathione, albeit at a slower rate. Analysis of simultaneous
binding of copper and cisplatin to Atox1 under physiological conditions
shows that both metals are bound to the protein through copper-sulfur-platinum
bridges
Probing silver deposition on single gold nanorods by their acoustic vibrations
10.1021/nl404304hNano Letters142915-922NALE