Jun

22

Not Science Fiction Anymore: Remote Control for the Brain

June 22, 2007 | Leave a Comment

Remote Control for the Brain – A New Protein Provides a Neuron Photoswitch. ‘The development of a remote control device that can be used to manipulate neural activity in a brain sounds like the premise of a science fiction film, probably a summer blockbuster starring Keanu Reeves. However, the device is real, it stars a team of Berkeley Lab and UC Berkeley scientists, and it holds enormous promise for future studies into how the brain works.
Ehud Isacoff, a biophysicist who holds joint appointments with Berkeley Lab’s Physical Biosciences Division and UC Berkeley’s Department of Molecular and Cell Biology, has led a study in which an artificial, light-activated protein was genetically engineered into the neurons of zebrafish. When a beam of light at a certain wavelength shines on the fish, it blocks their normal reflex response to a physical touch.
When the fish are illuminated with a second beam of light at a higher wavelength, the reflex response is restored. The engineered protein is called a “light-gated ionotropic glutamate receptor (LiGluR)” and was developed in a continuing collaboration between Isacoff and Dirk Trauner, a UC Berkeley chemistry professor.
“For the first time, we have the ability to target specific types of neurons within the neural circuits of a brain for selective activation,” Isacoff says. “This ability to stimulate select neurons, either in isolated tissue or in living animals, is a big advantage for scientists seeking to determine how specific neuronal cell types contribute to brain functions and behavior”.’

Jun

22

What Does an Unparticle Look Like? What is an unparticle?

June 22, 2007 | 2 Comments

The hunt for unparticles is on. ‘When the Large Hadron Collider turns on next year, most physicists will be scouring the high-energy data for new particles such as the Higgs boson. Not Howard Georgi of Harvard University in the US, though – he says he is on the look out for a new type of “stuff” altogether called “unparticles”. If it exists, it would mean that our Standard Model of particle physics is not the whole story, and that things other than particles fill the universe (Phys. Rev. Lett. 98 221601).
Unparticles would have properties in common with neutrinos, which have almost zero mass and are therefore nearly scale invariant. Neutrinos barely interact with matter – most of the time physicists can only infer their presence by calculating the “missing” energy and momentum after an interaction. By looking at the same interaction many times, a probability distribution is built up that tells more specifically how many and what sort of neutrinos are involved.
Georgi thinks that a similar technique could be used to search for evidence of unparticles. According to scale invariance, a distribution containing unparticles would become apparent because, oddly, it would look like a distribution for a fractional number of massless particles.’

See also: Professor proposes theory of unparticle physics. ‘Howard Georgi, a physicist at Harvard University, has recently published a paper on so-called unparticle physics, which suggests the existence of “unparticle stuff” that cannot be accounted for by the standard model. Appearing in a recent edition of Physical Review Letters, the paper says that unparticle stuff would be very different than anything seen before.’

Jun

18

Artnatomy: An Interactive Learning Tool for Facial Expressions

June 18, 2007 | Leave a Comment

Artnatomy – Anatomical Basis of Facial Expressions Learning Tool. ‘This resource has been designed and constructed to exploit digital technology in the context of Fine Art anatomical study. It is intended to facilitate the teaching and learning of the anatomical and biomechanical foundation of facial expression morphology. This resource does not add new material but refers to existing sources. The presentation of material takes advantage of digital animation, interactivity and multimedia presentation techniques as the means to facilitate visual understanding and learning.
The primary goal is to provide the student and those interested, a convenient reference tool, facilitating familiarity and experimentation with the underlying anatomical structures using correct biomechanical representation of the different facial expressions.’

Jun

18

Luminescent Nanoparticles as Cancer Imaging Probes

June 18, 2007 | Leave a Comment

Persistently Bright Nanoparticle Images Tumors. ‘In a new take on use of luminescent nanoparticles as cancer imaging probes, a team of investigators from several research institutes in Paris, France, has developed new metal-containing nanoparticles that emit light for several hours after they are initially excited. The researchers have demonstrated that once these nanoparticles are excited, they can then be injected into an animal and imaged without any additional energy input.
Reporting their work in the Proceedings of the National Academy of Sciences of the United States of America, Daniel Scherman, Ph.D., Quentin le Masne de Chermont, Ph.D., and colleagues describe their methods for synthesizing inorganic magnesium silicate-based nanoparticles doped with luminescent metals such as europium and dysprosium along with atoms of manganese. The particles range in diameter from 50 to 100 nanometers. Characterization experiments showed that the luminescent metal atoms concentrate in the center of the resulting nanoparticles together with the manganese atoms, forming an electronic core that can absorb light energy and emit red to near-infrared light for prolonged periods of time.’

Jun

17

Cerium Oxide Nanoparticles Used in Glaucoma Treatment

June 17, 2007 | Leave a Comment

UCF Nanoparticle Offers Promise for Treating Glaucoma. ‘A unique nanoparticle made in a laboratory at the University of Central Florida is proving promising as a drug delivery device for treating glaucoma, an eye disease that can cause blindness and affects millions of people worldwide.
The nanoparticle can safely get past the blood-brain barrier making it an effective non-toxic tool for drug delivery, said Sudipta Seal, an engineering professor with appointments in UCF’s Advanced Materials Processing and Analysis Center and the Nanoscience Technology Center.
The findings will be published in an article appearing in the June 28 issue of the Journal of Physical Chemistry C.
Seal and his colleagues from North Dakota State University note in the article that while barely 1-3 percent of existing glaucoma medicines penetrate into the eye, earlier experiments with nanoparticles have shown not only high penetration rates but also little patient discomfort. The miniscule size of the nanoparticles makes them less abrasive than some of the complex polymers now used in most eye drops.
Seal and his team created a specialized cerium oxide nanoparticle and bound it with a compound that has been shown to block the activity of an enzyme (hCAII) believed to play a central role in causing glaucoma.
The disease involves abnormally high pressure of the fluid inside the eye, which, if left untreated, can result in damage to the optic nerve and vision loss. High pressure occurs, in part, because of a buildup of carbon dioxide inside the eye, and the compound blocks the enzyme that produces carbon dioxide.’

Oven cleaner offers glaucoma hope. ‘A substance found in oven cleaner could be used to treat the eye disease glaucoma, US research suggests. Cerium oxide nanoparticles, also commonly used in window cleaner, may help in more effectively delivering an active ingredient into the eye.’

Article: Surface-Derivatized Nanoceria with Human Carbonic Anhydrase II Inhibitors and Fluorophores: A Potential Drug Delivery Device (PDF), Swanand Patil, Serge Reshetnikov, Manas K. Haldar, Sudipta Seal and Sanku Mallik, J. Phys. Chem. C 111, 8437-8442 (2007). Abstract: Human carbonic anhydrase (hCAII) is a metalloenzyme that catalyzes the reversible hydration of carbon dioxide to bicarbonate and is associated with glaucoma (a major cause of blindness). The present study focuses on the use of cerium oxide nanoparticles (nanoceria) as a potential delivery device for hCAII inhibitors. Carboxybenzenesulfonamide, an inhibitor of the hCAII enzyme, was attached to nanoceria particles using epichlorohydrin as an intermediate linkage. Along with the CA inhibitor, a fluorophore (carboxyfluorescein) was also attached on the nanoparticles to enable the tracking of the nanoparticles in vitro as well as in vivo. X-ray photoelectron spectroscopic studies carried out at each reaction step confirmed the successful derivatization of the nanoceria particles. The attachment of carboxyfluorescein was also confirmed by confocal fluorescence microscopy. Preliminary studies suggest that carboxybenzenesulfonamide-functionalized nanoceria retains its inhibitory potency for hCAII.’

Other applications of Cerium Oxide Nanparticles:
Ceria nanoparticles catalyze reactions for cleaner-fuel future
Could nanoparticles be designed to become potent antioxidants?
Nanoparticles of cerium oxide–application to coatings technologies
Nanoparticles offer hope for frayed nerves
New Catalyst Could Help Diesels Meet NOx Deadlines While Saving Energy
Chance Of A Lifetime. As they steward their products into the market, nanomaterial producers have the opportunity to address environmental, health, and safety concerns from the start.’