Abstract& These experiments use functional magnetic resonance imaging (fMRI) to reveal neural activity uniquely associated with perception of biological motion. We isolated brain areas activated during the viewing of point-light figures, then compared those areas to regions known to be involved in coherent-motion perception and kinetic-boundary perception.

Halloysite aluminosilicate nanotubes with a 15 nm lumen, 50 nm external diameter, and length of 800 +/- 300 nm have been developed as an entrapment system for loading, storage, and controlled release of anticorrosion agents and biocides. Fundamental research to enable the control of release rates from hours to months is being undertaken. By variation of internal fluidic properties, the formation of nanoshells over the nanotubes and by creation of smart caps at the tube ends it is possible to develop further means of controlling the rate of release. Anticorrosive halloysite coatings are in development and a self-healing approach has been developed for repair mechanisms through response activation to external impacts. In this Perspective, applications of halloysite as nanometer-scale containers are discussed, including the use of halloysite tubes as drug releasing agents, as biomimetic reaction vessels, and as additives in biocide and protective coatings. Halloysite nanotubes are available in thousands of tons, and remain sophisticated and novel natural nanomaterials which can be used for the loading of agents for metal and plastic anticorrosion and biocide protection.

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Purpose-The objective of this study was to assess changes in the water apparent diffusion coefficient (ADC) and in pharmacokinetic parameters obtained from the fast-exchange regime (FXR) modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during neoadjuvant chemotherapy in breast cancer.Materials and Methods-Eleven patients with locally advanced breast cancer underwent MRI examination prior to and after chemotherapy but prior to surgery. A 1.5-T scanner was used to obtain T 1 , ADC and DCE-MRI data. DCE-MRI data were analyzed by the FXR model returning estimates of K trans (volume transfer constant), ν e (extravascular extracellular volume fraction) and τs i (average intracellular water lifetime). Histogram and correlation analyses assessed parameter changes posttreatment.Results-Significant ( P <.05) changes or trends towards significance ( P <.10) were seen in all parameters except τ i , although there was qualitative reduction in τ i values post-treatment. In particular, there was reduction ( P <.035) in voxels with K trans values in the range 0.2-0.5 min -1 and a decrease ( P <.05) in voxels with ADC values in the range 0.99×10 -3 to 1.35×10 -3 mm 2 /s. ADC and ν e were negatively correlated (r = -.60, P <.02). Parameters sensitive to water distribution and geometry (T 1 , ν e ,τs i and ADC) correlated with a multivariable linear regression model. Conclusion-The analysis presented here is sensitive to longitudinal changes in breast tumor status; K trans and ADC are most sensitive to these changes. Relationships between parameters provide information on water distribution and geometry in the tumor environment.

Halloysite clay nanotubes were investigated as a tubular container for the corrosion inhibitor benzotriazole. Halloysite is a naturally occurring cylindrical clay mineral with an internal diameter in the nanometer range and a length up to several micrometers, yielding a high-aspect-ratio hollow tube structure. Halloysite may be used as an additive in paints to produce a functional composite coating material. A maximum benzotriazole loading of 5% by weight was achieved for clay tubes of 50 nm external diameters and lumen of 15 nm. Variable release rates of the corrosion inhibitor were possible in a range between 5 and 100 h, as was demonstrated by formation of stoppers at tube openings. The anticorrosive performance of the sol-gel coating and paint loaded with 2-5% of halloysite-entrapped benzotriazole was tested on copper and on 2024-aluminum alloy by direct exposure of the metal plates to corrosive media. Kinetics of the corrosion spot formation at the coating defects was analyzed by the scanning vibrating electrode technique, and an essential damping of corrosion development was demonstrated for halloysite-loaded samples.

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Monomeric, but polymerizable, lecithins with diacetylenic fatty acyl chains, such as l,2-bis(10,12-tricosadiynoyl)-.w-glycero-3-phosphocholine (DCg 9PC), are known to form tubular microstructures when liposomes of these lipids are cooled through their chain melting transition. These lipids are soluble in alcohols and other organic solvents, but when such solutions are diluted with water at appropriate temperatures, precipitates form. From optical and electron microscopy the precipitates are seen to consist of tubules and long, open helical structures with diameters similar to those of the tubules. These helices are all right handed when made from lipid with the naturally occurring chiral head group. For an ethanol/water system the proportion of helices and tubules depends on the ratio of the solvent to nonsolvent, as does the overall length of the tubules. The temperature, lipid concentration, and specific solvent used also affect the nature of the precipitate. For DCg 9PC the tubular and helical microstructures vary from 0.3 to 3 pm in diameter, and from 5 to over 1000 pm in length. The width and pitch of the helical ribbons are variable, resulting in a range of structures from open helices to continuous tubules depending on the solvent system used. Upon exposure to energetic radiation such as UV rays or 7-rays, the diacetylenic units polymerize without causing loss of the helical or tubular microstructure, thereby stabilizing the microstructures. Demonstration of this formation route for tubules suggests that they are thermodynamically stable, not accidental products of deforming liposomes. The existence of this polymerizable helical microstructure that may be an intermediate in the formation of tubules supports previous indications of an underlying helical structure to tubules. This precipitation method also affords a simple method of controlling the dimensions of tubules and a screening method for the discovery of other self-organizing lipid microstructures.