The hollow gold nanospheres developed in the laboratory of Jin Zhang, a professor of chemistry and biochemistry at UCSC, have a unique set of properties, including strong, narrow, and tunable absorption of light. Zhang is collaborating with researchers at the University of Texas M. D. Anderson Cancer Center, who have used the new nanostructures to target tumors for photothermal cancer therapy. They reported good results from preclinical studies earlier this year (Clinical Cancer Research, February 1, 2009).

Zhang described his lab’s work on the hollow gold nanospheres in a talk on Sunday, March 22, at the annual meeting of the American Chemical Society in Salt Lake City.

“What makes this structure special is the combination of the spherical shape, the small size, and the strong absorption in visible and near infrared light,” Zhang said. “The absorption is not only strong, it is also narrow and tunable. All of these properties are important for cancer treatment.”

Zhang’s lab is able to control the synthesis of the hollow gold nanospheres to produce particles with consistent size and optical properties. The hollow particles can be made in sizes ranging from 20 to 70 nanometers in diameter, which is an ideal range for biological applications that require particles to be incorporated into living cells. The optical properties can be tuned by varying the particle size and wall thickness.

In the cancer studies, led by Chun Li of the M. D. Anderson Cancer Center, researchers attached a short peptide to the nanospheres that enabled the particles to bind to tumor cells. After injecting the nanospheres into mice with melanoma, the researchers irradiated the animals’ tumors with near-infrared light from a laser, heating the gold nanospheres and selectively killing the cancer cells to which the particles were bound.

Cancer therapy was not the goal, however, when Zhang’s lab began working several years ago on the synthesis and characterization of hollow gold nanospheres. Zhang has studied a wide range of metal nanostructures to optimize their properties for surface-enhanced Raman scattering (SERS). SERS is a powerful optical technique that can be used for sensitive detection of biological molecules and other applications.

Adam Schwartzberg, then a graduate student in Zhang’s lab at UCSC, initially set out to reproduce work reported by Chinese researchers in 2005. In the process, he perfected the synthesis of the hollow gold nanospheres, then demonstrated and characterized their SERS activity.

“This process is able to produce SERS-active nanoparticles that are significantly smaller than traditional nanoparticle structures used for SERS, providing a sensor element that can be more easily incorporated into cells for localized intracellular measurements,” Schwartzberg, now at UC Berkeley, reported in a 2006 paper published in Analytical Chemistry.

The collaboration with Li began when Zhang heard him speak at a conference about using solid nanoparticles for photothermal cancer therapy. Zhang immediately saw the advantages of the hollow gold nanospheres for this technique. Li uses near-infrared light in the procedure because it provides good tissue penetration. But the solid gold nanoparticles he was using do not absorb near-infrared light efficiently. Zhang told Li he could synthesize hollow gold nanospheres that absorb light most efficiently at precisely the wavelength (800 nanometers) emitted by Li’s near-infrared laser.

“The heat that kills the cancer cells depends on light absorption by the metal nanoparticles, so more efficient absorption of the light is better,” Zhang said. “The hollow gold nanospheres were 50 times more effective than solid gold nanoparticles for light absorption in the near-infrared.”

Zhang’s group has been exploring other nanostructures that can be synthesized using the same techniques. For example, graduate student Tammy Olson has designed hollow double-nanoshell structures of gold and silver, which show enhanced SERS activities compared to the hollow gold nanospheres.

The ability to tune the optical properties of the hollow nanospheres makes them highly versatile, Zhang said. “It is a unique structure that offers true advantages over other nanostructures, so it has a lot of potential,” he said.

Source: Tim Stephens
University of California – Santa Cruz

In a paper titled, “Diagnostic Assay Based on has-miR-205 Expression Distinguishes Squamous From Non-Squamous Non-Small-Cell Lung Carcinoma,” researchers looked at 252 patients with lung cancer and sent their tumor samples to a lab where a single microRNA biomarker identified squamous lung carcinomas with 96% sensitivity and 90% specificity. This is important because studies have shown that as many as 30% of squamous lung cancers are misclassified. If the type of lung cancer is not identified correctly, patients may have side effects due to treatment and medications. For example, squamous lung cancer carries increased risk of severe or fatal bleeding for certain targeted biological therapies including Bevacizumab (Avastin) and other drugs in development. Other approved therapies such as Pemetrexed (Alimta) are indicated for non-squamous lung cancer only.

The study, funded by Rosetta Genomics, was conducted at the NYU Cancer Institute at NYU Langone Medical Center in collaboration with researchers from Columbia University and Sheba Medical Center.

“The results of this study are very encouraging,” says Harvey Pass, MD, professor of cardiothoracic surgery and director, thoracic surgery and oncology at the NYU Cancer Institute at NYU Langone Medical Center. “The study has demonstrated that a microRNA biomarker successfully identifies squamous lung cancer with high reproducibility, sensitivity and specificity. “The study certainly demonstrates the power of microRNAs in correctly classifying lung cancer and hopefully can immediately translate into more accurate choices of targeted therapies as well as cytotoxics for the disease.”

Dr. Pass is the Vice chairman medical advisory board for Rosetta Genomics (Nasdaq: ROSG), the company who makes a test based on the same microRNA biomarker that was evaluated by the study. The test offers similar accuracy (97% sensitivity) and is now commercially available through Rosetta Genomics CLIA-certified lab in Philadelphia.

Notes:

About NYU Langone Medical Center

Located in the heart of New York City, NYU Langone Medical Center is a premier center for health care, biomedical research, and medical education. For over 167 years, NYU physicians and researchers have contributed to the practice and science of medicine. Today the Medical Center consists of NYU School of Medicine; Rusk Institute of Rehabilitation Medicine, the first and largest facility of its kind; NYU Hospital for Joint Diseases, a leader in musculoskeletal care; and such nationally recognized programs as the NYU Cancer Institute, the NYU Child Study Center, and the NYU Cardiac and Vascular Institute.

About NYU Cancer Institute

The NYU Cancer Institute is an NCI-designated cancer center. Its mission is to discover the origins of human cancer and to use that knowledge to eradicate the personal and societal burden of cancer in our community, the nation and the world. The center and its multidisciplinary team of experts provide access to the latest treatment options and clinical trials along with a variety of programs in cancer prevention, screening, diagnostics, genetic counseling and supportive services. For additional information, please visit: http://www.nyuci.org.

The study, “3D Ultrasound Can Contribute to Planning CT to Define the Target for Partial Breast Radiotherapy,” conducted at the Radiation Therapy Program, British Columbia Cancer Agency, Vancouver Island Centre and the University of British Columbia, examined 20 consecutive cases of early-stage breast cancer where the patients were treated with breast-conserving surgery. Researchers found that in 40 percent of cases, the variability between lumpectomy cavity contours was reduced when ultrasound was used instead of CT – the current standard of care for planning breast cancer treatment. In particular, 3D ultrasound proved to be particularly beneficial for imaging patients with dense breasts and small cavities.

“Precision in planning and the increased certainty that radiation is being delivered to the exact area where it is needed have never been more critical, with the percentage of patients opting for breast conservation therapy and PBI on the rise,” said Pauline Truong, MD, CM, a researcher on the study. “Following this study, however, it is clear that the benefits of this technology could be applicable to not only PBI patients, but those undergoing whole breast radiation and electron boost therapy – potentially helping an even larger population of women with breast cancer.”

The Clarity Breast System marks the first application of 3D ultrasound technology to Image-Guided Radiation Therapy (IGRT) in breast cancer. The Clarity system was cleared by the U.S. Food and Drug Administration in 2004 for guidance in the treatment of prostate and breast cancers.

In addition to its application with treatment planning, the Clarity System is also used to image the lumpectomy cavity daily with each radiation treatment, to get an actual visual image and location of the tumor cavity on a regular basis. While the breast cancer radiation oncology community is aware that the location of the lumpectomy cavity target can change throughout the course of treatment, this issue is still largely unaccounted for in current treatment protocols. Clinical consequences can include delivery of radiation to healthy tissue, application of radiation too close to the chest wall or skin and, in some cases, under-treatment of certain areas. Clarity provides the first method of daily lumpectomy cavity monitoring that is based on visualization of the actual anatomy–rather than an estimation of the location of the cavity. This precision in planning and treatment could enable physicians to reduce the field of radiation they need to deliver, which is always preferable if clinically justified.

Several studies detailing the benefits of the use of Clarity during breast cancer treatment have also been presented in recent months. For example:

– At the 2008 Annual Meeting of the American Society for Therapeutic Radiation Oncology (ASTRO), data from a study conducted at McGill University and the University of Vermont was presented investigating the use of the Clarity system to track tumor cavity movement prior to daily treatments. The study compared the use of 3D ultrasound to CT, and found that these techniques were statistically equivalent. Researchers concluded that because ultrasound is non-ionizing and non-invasive, it is preferable to daily CT for tumor cavity monitoring.

– Additionally, at the 2008 meeting of the Radiological Society of North America (RSNA), data collected at Beth Israel Medical Center in New York on the use of Clarity when delivering electron boost therapy was examined. Although electron boost treatments have been delivered for quite some time, there has been no way to ensure that the electron dose is treating the correct area. This study found that in 45 percent of treatments, part of the tumor cavity would have been outside of the dose region and would have been missed without ultrasound guidance.

“The Clarity System has been used in the treatment of thousands of prostate cancer patients, and we are encouraged by the results and feedback we have seen and heard from radiation oncologists regarding its application with breast cancer,” said Tony Falco, PhD, FCCP, Founder and Chief Executive Officer of Resonant Medical. “This mounting clinical evidence acknowledges the value of the Clarity system for the effective planning and treatment of breast cancer.”

About Resonant Medical

Resonant Medical (Montreal, Canada) develops, manufactures and commercializes 3D ultrasound image-guided adaptive radiotherapy products. Originally developed at McGill University Health Center, Resonant’s technologies are available in more than 50 cancer centers in the U.S., Canada and Europe, helping cancer centers make significant improvements in radiation therapy planning, verification and delivery–advancing patient care. Resonant can be found on the Web at http://www.resonantmedical.com

A new type of asthma therapy might be especially helpful for people with severe asthma who often have to take oral steroids to control their symptoms.

The drug is called mepolizumab, and two small studies in the March 5 issue of the New England Journal of Medicine have found that, when taken regularly, it can reduce asthma exacerbations. Additionally, people taking the drug had lower levels of eosinophils, a type of white blood cell that has been implicated as a potential cause of asthma.

“This is a new treatment which substantially reduces the risk of asthma attacks in a severe asthma population,” said the senior author of one of the studies, Dr. Ian Pavord, a consultant physician and an honorary professor of medicine at Glenfield Hospital, University Hospitals of Leicester, England.

Dr. Paul O’Byrne, the senior author of the other study, added that “we now have a likely new treatment modality that will improve outcomes and reduce exacerbations in severe prednisone-dependent asthma, and this is not a small population — it’s probably 2 to 4 percent of the asthmatic population.” O’Byrne is chairman of the Department of Medicine at McMaster University and executive director of the Firestone Institute for Respiratory Health at St. Joseph’s Hospital in Hamilton, Ontario, Canada.

Both studies were funded by GlaxcoSmithKline, the pharmaceutical company that is developing the drug.

He said that mepolizumab works by blocking a protein called interleukin-5, which is essential for the development of eosinophils. Eosinophils have long been implicated in asthma, though their exact role remains unclear. However, scientists do know that when an asthma exacerbation occurs, eosinophil levels usually rise.

In the first study, Pavord and his colleagues randomly placed 61 people with severe asthma on either 750 milligrams of mepolizumab or a placebo for a year. The drug and placebo were administered intravenously once a month for a year.

Over the study period, those on mepolizumab had fewer asthma exacerbations than those on placebo — 2 versus 3.4. People taking the drug also reported a greater improvement in their quality of life than did people taking the placebo.

The second study was smaller, including just 20 patients. Nine received 750 mg of mepolizumab, and 11 were given a placebo. Again, the drug and placebo were administered in intravenous doses once a month.

Everyone in this study had severe, prednisone-dependent asthma. Prednisone is an oral steroid that is generally quite effective in treating asthma but has numerous and serious side effects.

In the six-month trial, there were 12 asthma exacerbations in 10 people on placebo. Nine had evidence of eosinophils during their exacerbations. During the study, just one person in the treatment group had an exacerbation, but no eosinophils were present. Additionally, those taking the drug were able to reduce their dosage of prednisone more than people on placebo could.

Mepolizumab was not associated with a serious side effect in either study, though both authors pointed out that the studies were small and no more than six months to a year long.

“If you are one of those people [who has eosinophils] and your asthma is pretty severe, this may be a relatively promising treatment to prevent exacerbations, though it’s still experimental,” said the author of an accompanying editorial in the same issue of the journal, Dr. Sally Wenzel, director of the Asthma and Allergy Center at the University of Pittsburgh Medical Center.

But, she pointed out that not everyone who has asthma also has eosinophils.

All three experts said they were not sure if mepolizumab would have a place in treating less severe asthma, at least for awhile. O’Byrne said that the drug needs to be studied in larger populations and it’s currently very expensive, which would limit its use by people who have other treatment options.

The 28-year-old Ph.D. candidate in the Harvard-MIT Division of Health Sciences and Technology (HST) received the prestigious $30,000 Lemelson-MIT Student Prize for his promising innovations in the area of cancer therapy, specifically two inventions in nanomedicine: a new class of cancer therapeutics and a new paradigm for enhancing drug delivery to tumors.

Cancer currently kills more people worldwide than HIV/AIDS, tuberculosis and malaria combined. Despite billions of dollars invested into drug development and decades of research, selectively eradicating cancer cells has remained an elusive goal. Chemotherapies, a common class of cancer treatments, are intended to kill the fast-growing cells that form tumors. However, these drugs travel throughout the entire body, and often affect normal, healthy tissue along with cancer cells, causing side effects such as hair loss, nausea, anemia, and even nerve and muscle problems. Furthermore, resistance to these drugs can arise and can cause even initially successful treatment regimens to fail.

Working at the confluence of nanotechnology, engineering and medicine, von Maltzahn’s innovations have the potential to reduce side effects and overpower drug resistance mechanisms by more powerfully concentrating external energy and targeted therapeutics in tumors.

Using Gold Nano-Antennas to Target and Destroy Tumors

Since 2004, von Maltzahn has worked closely with his advisor, Dr. Sangeeta N. Bhatia, an electrical engineering and computer science professor in the Harvard-MIT Division of HST, to invent novel treatments that could precisely target and destroy tumor cells without affecting healthy tissue. Seeking to improve the specificity of cancer ablation – the destruction of tumors through the application of heat – von Maltzahn developed polymer-coated gold ‘nano-antennas’ that can target tumors and convert benign-infrared light into heat.

The nanoparticles are designed to be injected intravenously, where they circulate through the bloodstream and progressively concentrate at the tumor site by infiltrating pores in rapidly growing tumor blood vessels. Once in the tumor, the antennas can be precisely heated with a non-invasive, near-infrared light to specifically kill the cancerous cells. “The polymer coated gold nano-antennas are the longest-circulating and most efficiently heated to date,” states Dr. Bhatia. “Pre-clinical trials reveal that a single intravenous nanoparticle injection eradicated 100 percent of tumors in mice using a near-infrared light. The results of these trials are very promising, meaning that the impact of this technology is wide-reaching with many potential applications.”

Scout and Assassin: Communicating Nanoparticles

Von Maltzahn’s second invention aims to fundamentally improve the intravenous delivery of therapeutics to tumors by taking a ‘systems’ approach to their design. This work draws on insights from biological systems, like ants foraging and bees swarming, where relatively simple methods of communication can lead to very sophisticated system behaviors.

Inspired by the potential for inter-nanoparticle communication to improve therapeutics’ ability to find tumors, von Maltzahn invented a series of ways for nanoparticles to ‘talk’ to one another in the body. One method involves benign ‘scout’ particles initially locating the tumor and, once inside, sending powerful signals to recruit secondary, ‘assassin’ particles that contain the therapeutics. In pre-clinical trials, this system has been able to deliver over 40-times higher doses of therapeutics to tumors in mice, in comparison to non-communicating control nanoparticles.

“If such highly-targeted delivery can be achieved clinically, this method would enable doctors to increase the drug dose that is delivered to tumors, increasing its overall efficacy and reducing side-effects,” von Maltzahn explains. “This concept of engineering systems of nanoparticles that collectively outsmart disease barriers has many potential applications in medicine, from improving regenerative medicines to ultra-sensitive diagnostics.”

Looking Forward

Von Maltzahn’s work has already made a significant impact scientifically and commercially, resulting in eight patent applications, 19 submitted or published papers, and his founding roles in two companies: Nanopartz Inc. and Resonance Therapeutics.

Nanopartz was founded more than one year ago to address the nanotechnology industry’s need for dependable and standardized nanoparticle sources. Von Maltzahn’s goal with Nanopartz is to aid in research endeavors worldwide by supplying a repertoire of gold nanoparticles for a broad spectrum of commercial applications, ranging from biomedicine to energy.

Resonance Therapeutics was founded to bring nano-rods towards clinical applications and to develop technologies that amplify the efficacy of existing cancer therapeutics.

“In addition to the long hours spent in the lab, finishing up his Ph.D., and founding two companies, Geoff mentored 14 undergraduate students, taking them out of the classroom setting and inspiring them to make the link from science to the real world,” states Joshua Schuler, the executive director of the Lemelson-MIT Program. “Geoff is not only a mentor for aspiring scientists, but also a shining example of bridging the gap between technological invention and entrepreneurship.”

Additional Inventions

During von Maltzahn’s time at MIT he has also developed inventions outside of the polymer nano-rods and ‘systems nanotechnology’ paradigm for improving drug delivery, including: a low-cost method for hemorrhage detection; a new class of ‘self-assembling’ lipid-like peptides with promising applications in gene therapy; sensors for detecting tumor protease hot-spots in MRI; a method for remotely-controlling drug release from nanoparticles; and a variety of new nanostructures for improved drug delivery and imaging.

Collegiate Student Prize Expansion

On March 4th, the winners of the third annual $30,000 Lemelson-Illinois Student Prize and $30,000 Lemelson-Rensselaer Student Prize will be announced at the University of Illinois at Urbana-Champaign and Rensselaer Polytechnic Institute, respectively. Following, on March 5th the first $30,000 Lemelson-Caltech Student Prize will be announced at the California Institute of Technology.

Notes:

ABOUT THE $30,000 LEMELSON-MIT STUDENT PRIZE

The $30,000 Lemelson-MIT Student Prize is awarded annually to an MIT senior or graduate student who has created or improved a product or process, applied a technology in a new way, redesigned a system, or demonstrated remarkable inventiveness in other ways. A distinguished panel of MIT alumni including scientists, technologists, engineers and entrepreneurs chooses the winner.

ABOUT THE LEMELSON-MIT PROGRAM

The Lemelson-MIT Program recognizes outstanding inventors, encourages sustainable new solutions to real-world problems, and enables and inspires young people to pursue creative lives and careers through invention.

Jerome H. Lemelson, one of U.S. history’s most prolific inventors, and his wife Dorothy founded the Lemelson-MIT Program at the Massachusetts Institute of Technology in 1994. It is funded by the Lemelson Foundation, a philanthropy that celebrates and supports inventors and entrepreneurs in order to strengthen social and economic life in the U.S. and developing countries. More information on the Lemelson-MIT Program is online at http://web.mit.edu/invent/.

According to the New England Journal of Medicine1, dense breast tissue increases the risk of breast cancer for a woman up to five-fold. While mammography remains the method of choice in breast cancer screening, a study published by the RSNA (Radiological Society of North America) in 20022 showed that the detection rate for non-palpable, invasive breast cancer increased by 42 percent when mammography was followed by an ultrasound examination.

“I am convinced that automatic ultrasound volume imaging with the Acuson S2000 ABVS can make a significant contribution in diagnostic confidence for women with dense breast tissue or inconclusive mammography findings,” said Klaus Hambüchen, CEO, Ultrasound at Siemens Healthcare. Examinations performed with the Acuson S2000 ABVS technique generally take less than 15 minutes. “Time well spent if you consider the extended diagnostic capabilities of ultrasound in dense breasts.”

Coronal anatomical view

The system quickly and comfortably acquires and surveys full-field sonographic volume images that provide a more comprehensive overview of the breast. Included is the intuitive, anatomical coronal plane of the breast (from the nipple to the breast wall), which is not available with conventional ultrasound imaging. This view provides a more understandable representation of the global anatomy and architecture of the breast.

The system’s automatic image acquisition significantly improves the workflow of a breast ultrasound examination. While hand held examinations usually take up to 30 minutes, with the Acuson S2000 ABVS, the exam can be performed in less than 15 minutes. Semi-automated reporting and comprehensive BI-RADS® ultrasound reporting capabilities further enhance the clinical workflow. This Breast Imaging Reporting and Data System (BI-RADS) is a classification of the American College of Radiology (ACR) for reporting mammography screenings.

To further optimize high-volume patient care, the system also supports innovative breast imaging applications, such as Fatty Tissue and eSie Touch elasticity imaging. All of these applications help increase diagnostic confidence, while at the same time reducing examination and waiting time for the patient. The new system is an all-round system for ultrasound breast care, from early detection, to diagnosis to aftercare.

The Siemens Healthcare Sector is one of the largest suppliers of healthcare technology in the world. The company is a medical solution provider with core competences and innovative strengths in diagnostic and therapeutic technologies as well as knowledge processing, including information technology and system integration. With its acquisitions in laboratory diagnostics, Siemens Healthcare is the first integrated healthcare company that combines imaging and lab diagnostics, therapy solutions and medical information technology and also supplements these with consultation and services. Siemens Healthcare offers solutions for the entire supply chain under one roof – from prevention and early detection to diagnosis and on to treatment and aftercare. In addition, Siemens Healthcare is the global market leader for innovative hearing instruments. The company employs some 49,000 employees worldwide and is present in more than 130 countries. During fiscal 2008 (ending on September 30), Siemens Healthcare achieved sales of 11.17 billion euros and incoming orders totaling 11.78 billion euros. The Sector profit from operations amounted to 1.23 billion euros.

For more information, go to: www.siemens.com/healthcare

1 N Engl J Med 356;3. Boyd N.F. et Al., Mammographic Density and the Risk and Detection of Breast Cancer 2 Radiology 2002;225:165-175. Kolb T.M. et Al., Comparison of the Performance of Screening

Mammography, Physical Examination, and Breast US and Evaluation of Factors that Influence Them: An Analysis of 27,825 Patient Evaluations

ASPYRA AccessNET PACS is a modular designed PACS solution that ranges from imaging modality viewing stations to multi-facility, enterprise-wide implementations with load balancing, redundancy, and remote backup archives, allowing healthcare facilities to build systems with components that meet their needs. System features include flexible licensing, built-in web server for image and report access, flexible Storage (Archive) Solutions, user definable Search Lists and Work Lists, a full featured MedVIEW Viewer with intuitive human interface, and built in Dictation and Transcription functions based on common medical communication standards such as DICOM and HL7 that integrates with healthcare systems, protecting investments and streamlining workflow.

“We were amazed by the impressive performance using the Matrox Xenia Series,” says Bill Culton, Product Manager, Aspyra Inc. “The ability to window and level large image data quickly and smoothly on high resolution monitors are critical to medical imaging workflow and optimum patient care. By implementing Xenia’s new advanced hardware features we were able to significantly improve the response to changes on our viewer which will further enhance the user experience. ”

Matrox Xenia is the first native PCI Express single-slot board with all-digital, triple-monitor output and the flexibility to drive practically any known display configuration. Xenia Series supports resolutions from under 1MP up to 8MP, with up to 1GB of on-board memory, and features new technology to ensure optimum display calibration (via Matrox DLC™ and 8/10/13-bit gamma LUTs).

“Our goal was to quickly demonstrate the enhanced hardware functionality to Aspyra, an important development Partner who has contributed to our initial specification of the Matrox Xenia Series design;” says George Rigas, business development manager for medical imaging, Matrox Graphics Inc. “Ease of development was paramount for Aspyra developers to incorporate performance enhancements for efficient workflow and a better end user experience.”

With the development potential for increasing hardware-accelerated performance via hardware LUTs, multiple hardware window IDs, and additional hardware features, Xenia Series is a flexible and expandable solution for medical imaging developers and integrators looking for leading edge technology.

About Aspyra

Aspyra is a global provider of Health Care Information Technology (HCIT) solutions and services to the healthcare industry. The Company specializes in Clinical Information Systems (CIS), Picture Archive Communication Systems (PACS) and Clinical Image Management Systems (CIMS) for hospitals, multi-specialty clinics, clinical laboratories, imaging departments and centers and orthopedic environments. Aspyra’s highly scalable systems can be installed standalone or integrated to provide a single-vendor, enterprise-wide solution. For more information on Aspyra, its products and services, visit www.aspyra.com.

About Matrox Graphics Inc.

Matrox Graphics is a leading manufacturer of graphics solutions for professional markets. In-house design expertise, top-to-bottom manufacturing, and dedicated customer support make our solutions the premier choice in industries that require stable, high-reliability products. Founded in 1976, Matrox is a privately held company headquartered in Montreal, Canada, with representation and offices in the Americas, Europe, and Asia.

The study, “The Clinical Time-Course of Experimental Autoimmune Uveoretinitis Using Topical Endoscopic Fundal Imaging with Histologic and Cellular Infiltrate Correlation,” was published in the Association for Research in Vision and Ophthalmology journal Investigative Ophthalmology and Visual Science (Invest. Ophthalmol. Vis. Sci. 2008 49: 5458-5465).

It featured the use of Topical Endoscopic Fundal Imaging (TEFI), a technique that uses an endoscope with parallel illumination and observation channels connected to a digital camera. TEFI was developed by Michel Paques, et al (see Invest. Ophthalmol. Vis. Sci. 2007 48: 2769-2774).

David Copland, BSc, MSc, and the team from the University of Bristol’s Academic Unit of Ophthalmology monitored changes in the mice retina over time without distress to the animals or the need for anesthesia.

“TEFI enhances our monitoring of clinical disease in a rapid and non-invasive fashion,” the researchers reported. “It will aid in the design of experimental protocols according to clinical observations.”

The study focused on a condition similar to human posterior uveitis, which can be difficult to monitor using present techniques. TEFI allowed the researchers to see changes to the eye that were previously undetectable.

The researchers wrote that TEFI can help monitor the effects of new ocular therapies, as well as invasive procedures such as intravitreal or sub-retinal injections.

Though the method will be a helpful resource to improving detection, Copland’s team said the technology should be used in conjunction with existing techniques for monitoring the progression of eye diseases.

“Combined TEFI and histological methods enable the observation of clinical features and severity of disease, but information regarding the dynamics, phenotype, function and quantity of cellular traffic through the eye is only provided through detailed analysis of cell populations present in the eye at various stages of disease progression.”

Notes:

ARVO is the largest eye and vision research organization in the world. Members include more than 12,500 eye and vision researchers from over 73 countries. The Association encourages and assists research, training, publication and dissemination of knowledge in vision and ophthalmology. For more information, visit http://www.arvo.org

Working in partnership with the Indian Institute of Technology in Kanpur, they tested the numerical properties of a flat lens made out of ‘meta-material’ – a material that gains its properties from its structure rather than its composition. This material is thought to defy the laws of physics, allowing objects to appear exactly as they are rather than upside down as seen in a normal convex or concave lens.

Dr Sebastien Guenneau, from Liverpool’s Department of Mathematical Sciences, explains: “We know that light can be controlled using ‘meta-material’ which can bend electromagnetic radiation around an area of space, making any object within it appear invisible. Now we have produced a mathematical model that proves this theory also works for sound.

“This theory becomes particularly interesting when considering ultrasound, which is a sound pressure used to penetrate an object to help produce an image of what the object looks like inside. This is most commonly used in pregnancy scans to produce an image of a foetus. We found that at a particular wave frequency the meta-material has a negative refraction effect, which means that the image produced in the flat lens appears at a high resolution in exactly the same way it appears in reality.

“What surprised us most of all, however, was at the point where negative refraction occurs the meta-material becomes invisible, suggesting that if we were to use this in sonogram technology, it could be possible to make the image appear in mid-air like a hologram rather than on a computer screen. We also found that if we arranged the meta-material in a checkerboard fashion, sound became trapped, making noisy machines, for example, quieter.”

The scientists predict that the technology could be adapted for tests at higher sound frequencies such as when drilling for oil, where a more accurate image of the earth could be made in order to pin point where drilling should take place.

“There are all sorts of rules about what crystals can do during phase transitions,” said Mark D. Hollingsworth, associate professor of chemistry at Kansas State University. “For a long time, scientists have assumed that the norm applied for all sorts of substances.

But aperiodic materials — those that lack a regularly repeating structure — don’t necessarily work like this, Hollingsworth said.

These aperiodic, rule-bending crystals are the focus of an article co-authored by Hollingsworth that appears in the Jan. 4 issue of the journal Science. Building on results from Hollingsworth’s collaborator, French researcher Bertrand Toudic, Hollingsworth, Toudic and their co-authors looked at how these aperiodic crystals behave differently from “normal” periodic crystals. These differences could have implications not only for research but also for technology that relies on crystals, from computer displays to hard drives, Hollingsworth said.

For the research featured in the Science article, Hollingsworth and colleagues looked at crystals that form a host-guest structure. In this case, urea molecules formed tunnels around nonadecane molecules, making a honeycomb-like structure that takes the form of a double-helix — the shape of DNA. In periodic host-guest crystals, Hollingsworth said the host molecules forming the tunnels and the guest molecules inside form a regularly repeating structure. But not so with the rule-breaking aperiodic crystals.

“Sometimes the host and guest fit nicely, sometimes they don’t,” Hollingsworth said. “This can have a huge effect on all sorts of properties. During crystal growth, for example, periodic and aperiodic host-guest crystals can behave very differently.”

In aperiodic crystals, in which the host and guest structures don’t match, the guest molecules protrude from the ends of the crystals, making the surface rough. This means it’s easier to attach new molecules to the end of the crystal. Such crystals, including the ones featured in the Science article, are shaped like long needles.

But it really gets weird when the crystals undergo transitions from one phase to another.

“Bertrand and I have been talking about this for years, trying to find out what’s going on in this system,” Hollingsworth said. “The idea of studying these systems is to better understand how phase transitions work in aperiodic materials.”

To find out what’s going on in the phase transitions, the researchers observed the crystals at different temperatures above the phase transition, when the guest molecules are moving rapidly inside their tunnel-like hosts, and also at extremely cold temperatures as molecules are becoming frozen in place. To probe the crystals, the researchers scattered neutrons from them and measured different types of reflections. One class of reflections, called satellite reflections, measures the interaction between the guest and host molecules.

The researchers were surprised by what happened when the crystal was cooled to about -190 degrees Fahrenheit. The satellite reflections showed a change in the interaction between the host and guest structures but no noticeable changes in either the host or guest structures themselves.

“Previously, we thought these materials had homogenous phase transitions and that the normal rules concerning symmetry breaking applied to them,” Hollingsworth said. “I don’t think anyone would have predicted what happens in this phase transition.”

Because these aperiodic materials don’t play by the same rules, Hollingsworth said the impact on research is that scientists need to figure out what rules these aperiodic crystals are playing by in phase transitions. In addition to affecting research, these different rules also could have impacts on technology, he said. Crystals like the ones featured in the Science article are ferroelastic. That means that the molecules within the crystals reorient when the crystals are squeezed. The researchers can do this with a small anvil and observe the rotations of large domains in the crystals by viewing the crystal under a microscope. Closely related ferroelectric materials are important to technology because the domains within these materials can be reoriented with electric fields to allow or prohibit polarized light to pass through. This makes them useful in electronic displays.

“The question is whether these phases that we have observed will have unusual properties that are useful,” he said.

As research on aperiodic crystals continues, Hollingsworth said that researchers expect this same unusual phase transition behavior in materials other than the urea-nonadecane crystals used in this study.