Archive for ‘Forensic Science’

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Metal Coated Microspheres Market Propelled by Rising Demand from Electronics Industry

Metal Coated Microspheres Market Propelled by Rising Demand from Electronics Industry

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Microspheres are innovative materials with extremely small size and diameters ranging from 1 micrometer to 1 millimeter. It’s the small size of microspheres that makes them apt for various applications such as aerospace, electronics, outdoor billboards, cosmetics, and drug delivery. Microspheres come in two forms: hollow and solid. Each form of microsphere has a particular set of application areas. Microspheres are made from synthetic or non-synthetic materials.

Perceptions for the Forthcoming Trends of Metal Coated Microspheres Market at: http://www.transparencymarketresearch.com/sample/sample.php?flag=B&rep_id=3803

There are various forms of microspheres in the global market, such as polymer microspheres, ceramic microspheres, and glass microspheres. Metal-coated microspheres are microspheres that are developed using a combination of glass and polymer microspheres, along with a coating of certain metals. The metal coating on the microspheres (glass and polymer) gives them the additional benefit of being magnetic and having electrical properties. Thus, metal microspheres are used in applications such as electronics, manufacturing of composites, electromagnetic shielding, and as fillers for plastics.

The metals typically used for the manufacturing of metal-coated microspheres are: silver, gold, nickel, and aluminum. Other metals used for coating include tin, titanium, and iron. Since metal microspheres gain electric and magnetic properties, they are extensively used in the electronics industry. Due to the rising requirement of metal-coated microspheres in the electronics industry, the market for-metal coated microspheres is soaring. The market’s growth rate is high in the developed nations. The North America metal coated microspheres market is dominating the global metal coated microspheres market, followed by Europe and Asia Pacific.

In the future, the market is expected to be driven by the economic development and infrastructure development in emerging nations such as Indonesia and China. Moreover, the growing demand from all across the world for metal coated microspheres is set to boost the global metal coated microspheres market during the period from 2014 to 2020. According to the report, major companies dealing with metal coated microspheres will be focusing on the emerging nations in Asia Pacific, since the region demonstrates tremendous market potential.

Some of the leading players analyzed in the report are Momentive Performance Materials Inc., Cospheric LLC, Mo Sci Corp, 3M, and Potters Industries LLC. A comprehensive analysis of the strategies used by these leading companies has been presented in the report in a clear and easy-to-understand manner. Charts, tables, graphs, and figures have been used wherever required to depict information.

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New Technology for Turn-On Fluorescence Detection of Cyanide in Water

New Technology for Turn-On Fluorescence Detection of Cyanide in Water

New Technology for Turn-On Fluorescence Detection of Cyanide in Water

A molecular probe was prepared that selectively responds to cyanide in aqueous solutions by fluorescence enhancement. Using the peptide ?-turn as a structural template, we designed a series of diphenylacetylene derivatives in which the ?-conjugated backbone was functionalized with an aldehyde group to render the molecule nonfluorescent. The N-H···O hydrogen bond across the 2,2?-functionalized diphenylacetylene turn motif activates the carbonyl group toward nucleophilic attack, and chemical transformation of this internal quencher site by reaction with CN- elicits a rapid (k = 72 M-1 s-1) enhancement in the emission at ?max = 375 nm. Tethering of an ammonium group to the hydrogen bond donor fragment significantly increased both the response kinetics and the intensity of the fluorescence signal. In addition to providing electrostatic attraction toward the CN- ion, this positively charged R-NH3+ fragment can engage in a secondary hydrogen bond to facilitate the formation of the cyanohydrin adduct responsible for the signaling event. The structurally optimized molecular probe 3 responds exclusively to ?M-level cyanide in neutral aqueous solutions, with no interference from other common anions including F- and AcO-.

Citation data is made available by participants in CrossRef’s Cited-by Linking service. For a more comprehensive list of citations to this article, users are encouraged to perform a search in SciFinder.

54645kcn New Technology for Turn On Fluorescence Detection of Cyanide in WaterScientists from Indiana University Bloomington are reporting in J. Am. Chem. Soc. the development of a fluorescent molecular probe that can detect minuscule concentrations of cyanide in water at normal pH levels. This research can conceivably be extended into a commercialization stage to develop a simple and cheap cyanide detector:

“This is the first system that works in water at normal pH levels and can be modified at will to enhance its reactivity,” said IU Bloomington chemist Dongwhan Lee, who led the research. “We are now looking at how to make the detector more sensitive.”

Graduate student Junyong Jo is the report’s first author.

One of the reasons the detector is not ready for market, Lee says, is that its optical properties need to be improved to emit light at longer wavelengths with less interference from background signals, especially those of biological origin. Since pond or river water is likely to contain living organisms and other organic matter, Lee says the detector system must be perfected.

Another unique aspect of the detector molecule is its modular structure.

“This is an essentially three-component chemical device with an activator, a receptor, and a reporter module,” Lee said. “These three components we can change at will in the future, either to make the detector more sensitive, or have it detect an entirely different toxin by sending out signals as different colors of light. Because of the structure’s modularity, a change in one of the three components doesn’t really affect the others.”

Lee and Jo were inspired by life itself — the natural properties of proteins — when they began designing their sensor molecule. The design of this novel system takes advantage of the structure-organizing “beta turn” motif commonly found in protein structures. The detector is essentially inert, except in the presence of cyanide, with which it preferentially reacts. The addition of cyanide induces a subtle but important structural change in the detector that turns it into a pigment that absorbs ultraviolet light (currently 270 nm) and convert it to light emission at around 375 nm, a purplish color at the very edge of human beings’ normal vision range.

Cyanide is a negatively charged ion composed of one carbon and one nitrogen atom. Among its many chemical targets inside cells is the oxidative phosphorylation system, which is a crucial producer of energy. Cyanide disrupts the system, making it impossible for cells to maintain even the most basic processes, which is one reason cyanide is considered a poison.

Source : http://pubs.acs.org/doi/abs/10.1021/ja907056m

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New Fluorescent Technique Opens Window on Neuronal Activity

New Fluorescent Technique Opens Window on Neuronal Activity

New Fluorescent Technique Opens Window on Neuronal Activity

Researchers at the University of California, San Diego School of Medicine have created a new generation of fast-acting fluorescent dyes that optically highlight electrical activity in neuronal membranes. The work is published in this week’s online Early Edition of the Proceedings of the National Academy of Sciences.

The ability to visualize these small, fast-changing voltage differences between the interior and exterior of neurons – known as transmembrane potential – is considered a powerful method for deciphering how brain cells function and interact.

However, current monitoring methods fall short, said the study’s first author Evan W. Miller, a post-doctoral researcher in the lab of Roger Tsien, PhD, Howard Hughes Medical Institute investigator, UC San Diego professor of pharmacology, chemistry and biochemistry and 2008 Nobel Prize co-winner in chemistry for his work on green fluorescent protein.

“The most common method right now monitors the movement of calcium ions into the cell,” said Miller. “It provides some broad indication, but it’s an indirect measurement that misses activity we see when directly measuring voltage changes.”

Voltage Sensing Dyes

Leech neurons stained with voltage-sensitive dye.

The new method employs dyes that penetrate only the membrane of neurons, either in in vitro cells cultured with the dye or, for this study, taken up by neurons in a living leech model. When the dyed cells are exposed to light, neuronal firing causes the dye momentarily to glow more brightly, a flash that can be captured with a high-speed camera.

“One of the tradeoffs with using voltage-sensing dyes in the past is that when they were reasonably sensitive to voltage changes, they were slow compared to the actual physiological events,” said Miller. “The new dye gives big signals but is much faster and doesn’t perturb the neurons. We essentially see no lag time between the optical signal and electrodes (used to double-check neuronal activity).”

The new method provides a wider view of neuronal activity, said Miller. More importantly, it makes it possible for neuroscientists to do accurate, single trial experiments. “Right now, you have to repeat experiments with cells, and then average the results, which is physiologically less relevant and meaningful.”

For Tsien, the new dyes address a career-long challenge.

“These results are the first demonstration of a new mechanism to sense membrane voltage, which is particularly satisfying to me because this was the first problem I started working on as a graduate student in 1972, with little success back then,” said Tsien. “Later, we devised indirect solutions such as calcium imaging or dyes that gave big but slow responses to voltage. These techniques have been very useful in other areas of biology or in drug screening, but didn’t properly solve the original problem. I think we are finally on the right track, four decades later.”

Funding for this research came, in part, from the Howard Hughes Medical Institute, the National Institutes of Health, including the National Institute of Neurological Disorders and Stroke and the National Institute of Biomedical Imaging and Bioengineering.

Co-authors are John Y. Lin, Department of Pharmacology, UC San Diego; E. Paxon Frady, Neurosciences Graduate Group, UC San Diego; Paul A. Steinbach, Department of Pharmacology, UC San Diego and Howard Hughes Medical Institute; William B. Kristan, Jr., Division of Biological Sciences, UC San Diego.

Fluorescence imaging is an attractive method for monitoring neuronal activity. A key challenge for optically monitoring voltage is development of sensors that can give large and fast responses to changes in transmembrane potential. We now present fluorescent sensors that detect voltage changes in neurons by modulation of photo-induced electron transfer (PeT) from an electron donor through a synthetic molecular wire to a fluorophore. These dyes give bigger responses to voltage than electrochromic dyes, yet have much faster kinetics and much less added capacitance than existing sensors based on hydrophobic anions or voltage-sensitive ion channels. These features enable single-trial detection of synaptic and action potentials in cultured hippocampal neurons and intact leech ganglia. Voltage-dependent PeT should be amenable to much further optimization, but the existing probes are already valuable indicators of neuronal activity.

Studying neuronal activity has been difficult due to a lack of methods that provide localized, real time feedback. Researchers at University of California, San Diego School of Medicine have now developed a new technique that utilizes special voltage reactive dyes that only pass through the membrane of neurons. When light is applied to the dyed neurons, they glow slightly more in response. Because former techniques lacked precision, results of multiple experiments had to be averaged out in order to get a clear picture. With the new method, individual experiments on the activity of neurons can be conducted

From the announcement:

“One of the tradeoffs with using voltage-sensing dyes in the past is that when they were reasonably sensitive to voltage changes, they were slow compared to the actual physiological events,” said Miller [Evan W. Miller, a UCSD post-doc]. “The new dye gives big signals but is much faster and doesn’t perturb the neurons. We essentially see no lag time between the optical signal and electrodes (used to double-check neuronal activity).”

The new method provides a wider view of neuronal activity, said Miller. More importantly, it makes it possible for neuroscientists to do accurate, single trial experiments. “Right now, you have to repeat experiments with cells, and then average the results, which is physiologically less relevant and meaningful.”

For Tsien [Roger Tsien, PhD, Howard Hughes Medical Institute investigator, UC San Diego professor of pharmacology, chemistry and biochemistry and 2008 Nobel Prize co-winner in chemistry for his work on green fluorescent protein], the new dyes address a career-long challenge.

“These results are the first demonstration of a new mechanism to sense membrane voltage, which is particularly satisfying to me because this was the first problem I started working on as a graduate student in 1972, with little success back then,” said Tsien. “Later, we devised indirect solutions such as calcium imaging or dyes that gave big but slow responses to voltage. These techniques have been very useful in other areas of biology or in drug screening, but didn’t properly solve the original problem. I think we are finally on the right track, four decades later.”

Source : http://health.ucsd.edu/news/releases/Pages/2012-01-25-fluorescent-neurons.aspx

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New Tag Promises to Do for Electron Microscopy What GFP Did for Fluorescence Microscopy

New Tag Promises to Do for Electron Microscopy What GFP Did for Fluorescence Microscopy

New Tag Promises to Do for Electron Microscopy What GFP Did for Fluorescence Microscopy

The glowing green molecule known as green fluorescent protein (GFP) has revolutionized molecular biology. When GFP is attached to a particular protein inside a cell, scientists can easily identify and locate it using fluorescence microscopy. However, GFP can’t be used with electron microscopy, which offers much higher resolution than fluorescence microscopy.

Chemists from MIT have now designed a GFP equivalent for electron microscopy — a tag that allows scientists to label and visualize proteins with unprecedented clarity.

“With things that may appear only a few pixels across by fluorescence microscopy — for example, a mitochondrion — you can’t make out any of the internal features. But with electron microscopy it’s very easy to discern the intricate internal structures,” says Jeff Martell, a graduate student in chemistry at MIT and lead author of a paper describing the new tag in the Oct. 21 online edition of Nature Biotechnology.

The new tag could help scientists pinpoint the locations of many cell proteins, providing new insight into those proteins’ functions, according to the researchers.

Improving on nature

Dubbed APEX, the new tag is similar to naturally occurring proteins that have been tried as imaging labels for electron microscopy. Horseradish peroxidase (HRP) is one commonly used tag, but it works only in a few compartments of a cell. Other recently developed tags work throughout a cell but are technically challenging to use because they require light to be shined on the sample and oxygen to be bubbled through it.

To improve on these methods, the researchers started with a protein similar to HRP, called ascorbate peroxidase (APX). APX is more versatile than HRP because it can function within a cell’s cytosol, in the main cavity of a cell.

Both HRP and APX belong to a class of enzymes called peroxidases, which remove an electron and a proton from other molecules in a process known as oxidation. Every peroxidase has different targets, and one of HRP’s main targets is a molecule called DAB, which when oxidized can be visualized with electron microscopy. The researchers genetically engineered APX so that it would also target DAB.

To use this new APEX tag (for “engineered APX”), the researchers deliver, into a living cell, a small ring of DNA containing the APEX gene joined to the gene for the protein they plan to image. The cell then produces the target protein, bound to the APEX protein.

Next, the researchers need to deliver DAB, which is not normally found in cells. This delivery takes place during the process of “fixing,” or stabilizing cells, which must be done before they can be imaged with electron microscopy.

When the APEX protein oxidizes DAB, it generates radicals that rapidly clump together into a tarlike polymer. That polymer can be detected through electron microscopy, allowing the researchers to pinpoint the location of the target protein.

A biological question resolved

To demonstrate the usefulness of their new tag, the researchers set out to resolve an open question regarding the location of a calcium channel protein discovered last year. Two research groups identified the protein and reported that it is located within mitochondria, but they had conflicting theories as to its precise location and orientation. Using the new imaging technique, the MIT-led team labeled the protein and determined that it is embedded in the inner mitochondrial membrane and faces into the innermost part of mitochondria, the mitochondrial matrix.

The team also showed that the new tag can label proteins throughout the cell — not only within mitochondria but also in the nucleus, the endoplasmic reticulum and the cytosol.

Martell and Alice Ting, the Ellen Swallow Richards Associate Professor of Chemistry at MIT and senior author of the Nature Biotechnology paper, invented the new technology. Other authors who helped to test the tag and explore biological applications are Mark Ellisman, Thomas Deerinck and Gina Sosinsky of the University of California at San Diego, Yasemin Sancak and Vamsi Mootha of Harvard Medical School, and Thomas Poulos of the University of California at Irvine.

In current studies, the researchers are working on filling entire cells, such as neurons, with their imaging agent. This allows certain neurons in an electron microscope image to stand out, making it easier to trace the connections they make with other neurons. For that project, the MIT researchers are collaborating with Joshua Sanes, a professor of molecular and cellular biology at Harvard University, who says he believes the new labeling technology will be very useful.

“We want to find the exact connections that these cells are making, and APEX is a good way to label cells for electron microscopy. We can label specific types of cells and figure out how they fit into the neural circuitry,” Sanes says.

Ting and Martell have filed for a patent on their imaging technology and are now working on making the APEX molecule more stable and better able to bind heme (an iron atom embedded in an organic compound), which is necessary for it to function properly.

The research was funded by the National Institutes of Health.

Electron microscopy (EM) is the standard method for imaging cellular structures with nanometer resolution, but existing genetic tags are inactive in most cellular compartments1 or require light and can be difficult to use2. Here we report the development of ‘APEX’, a genetically encodable EM tag that is active in all cellular compartments and does not require light. APEX is a monomeric 28-kDa peroxidase that withstands strong EM fixation to give excellent ultrastructural preservation. We demonstrate the utility of APEX for high-resolution EM imaging of a variety of mammalian organelles and specific proteins using a simple and robust labeling procedure. We also fused APEX to the N or C terminus of the mitochondrial calcium uniporter (MCU), a recently identified channel whose topology is disputed3, 4. These fusions give EM contrast exclusively in the mitochondrial matrix, suggesting that both the N and C termini of MCU face the matrix. Because APEX staining is not dependent on light activation, APEX should make EM imaging of any cellular protein straightforward, regardless of the size or thickness of the specimen.

The invention of green fluorescent protein (GFP) as a tool for observing cellular activity under fluorescence microscopy has accelerated life science research and rightfully earned a Nobel in chemistry.

GFP is still limited in higher resolution applications because it is dependent on visible light, the wavelength of which is much larger than what is being studied. A team of researchers led by a couple chemists at MIT have developed a protein tag that works much like GFP but at nanometer resolution of electron microscopy.

From the study abstract in Nature Biotechnology:

Here we report the development of ‘APEX’, a genetically encodable EM tag that is active in all cellular compartments and does not require light. APEX is a monomeric 28-kDa peroxidase that withstands strong EM fixation to give excellent ultrastructural preservation. We demonstrate the utility of APEX for high-resolution EM imaging of a variety of mammalian organelles and specific proteins using a simple and robust labeling procedure. We also fused APEX to the N or C terminus of the mitochondrial calcium uniporter (MCU), a recently identified channel whose topology is disputed3, 4. These fusions give EM contrast exclusively in the mitochondrial matrix, suggesting that both the N and C termini of MCU face the matrix. Because APEX staining is not dependent on light activation, APEX should make EM imaging of any cellular protein straightforward, regardless of the size or thickness of the specimen.

Source : http://web.mit.edu/newsoffice/2012/a-new-glow-for-electron-microscopy-1021.html

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Beacon Endoscopic’s BNX System for EUS FNA

Beacon Endoscopic’s BNX System for EUS FNA

Engineered to improve clinical workflow by facilitating the passage of multiple needles through a single delivery system, without removing the delivery system.

Automated Needle Shield

Designed to cover needle sharp

Proprietary Glide Ball

Allows for interchangeability of all needle sizes through a universal delivery system

Start with one needle size and switch to any other size instantly during the same case, while using one universal delivery system

Engages automated needle shield during needle removal

Centers needle in catheter for consistent needle trajectory

Quad Bevel Design

4 cutting edges designed to optimize tissue yield and coring potential

Super-bright echogenic signature

22 and 25 Gauge Needle

Low cost, high performance

Designed to minimize kinking and improve overall performance

19 Gauge Nitinol Needle

Highly flexible Nitinol construction facilitates easy passage through tortuous positions

Allows for optimal tissue yield and coring potential via Quad Bevel design

Needle Exchange

Engineered for multiple needle exchanges throughout the procedure to improve clinical workflow

Ergonomic release button designed for fast, efficient removal of needle

Delivery System with PEBAX

Maintains flexibility and durability, reducing needle exposure to endoscope channel while remaining in position at point of interest

Beacon Endoscopic out of Newton, Massachusetts has developed an interesting new device for endoscopic ultrasound-guided fine needle aspiration (EUS FNA).

Beacon Endoscopics BNX System for EUS FNA (video)The BNX system is aimed at improving efficiency and safety when performing EUS FNA biopsies, and features interchangeable needle sizes. A company representative tells Medgadget that the company’s delivery system is “sold with multiple low cost needles that can be rapidly exchanged through the single delivery system, reducing the down time between needle passes, which improves the clinical workflow. When the needles are removed from the delivery system, they automatically integrate into a safety needle shield, designed to reduce the human errors (manually screwing and un-screwing a needle into a secure position) associated with needle sticks.”

source : http://www.beaconendoscopic.com/bnx-system

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ExoShape for ACL Surgery Now in Full Market Release

ExoShape for ACL Surgery Now in Full Market Release

ExoShape for ACL Surgery Now in Full Market Release

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Medshape out of Atlanta, GA is bringing to market its ExoShape Soft Tissue Fastener for anterior cruciate ligament (ACL) reconstructive surgery.

The device was offered to a limited number of sports medicine surgeons last year for evaluation and for refinement of the procedure.

From the announcement:

ExoShape’s enhanced design supports reconstruction techniques as they continue to evolve to more accurately replicate the complex functionality of the native ACL. It employs a unique non-rotational deployment technique that preserves the surgeon’s desired graft bundle orientation and tension during single tunnel-double bundle procedures.

medshape exoshape ExoShape for ACL Surgery Now in Full Market ReleaseWhen used with soft tissue grafts, traditional interference screws exhibit low ultimate yield loads and can damage the graft during insertion. In an attempt to overcome these issues, surgeons have turned to “sheath-and-screw” devices that offer improved graft fixation and graft protection. However, these solutions may continue to compromise graft bundle orientation due to the sheath rotating within the tibial tunnel, as significant manual torque is required to drive the screw into the sheath and achieve adequate interference fixation of the graft. The need to drive screws into these devices in a direction counter to the desired direction of graft tension may also introduce undesirable laxity into the graft construct.

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Source : http://www.marketwatch.com/Story/story/rescue?SourceUrl=http%3A%2F%2Fwww.marketwatch.com%2Fstory%2Fmedshape-inc-announces-full-commercial-release-of-exoshape-soft-tissue-fastener-2012-01-17

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Green Tea and Gold to Fight Prostate Cancer

Green Tea and Gold to Fight Prostate Cancer

Gold Nanoparticles Could Treat Prostate Cancer With Fewer Side Effects than Chemotherapy, MU Researchers Find

VIDEO: Gold Nanoparticles Could Treat Prostate Cancer With Fewer Side Effects than Chemotherapy

This video is available for broadcast quality download and re-use. For more information, contact Nathan Hurst at hurstn@missouri.edu.

COLUMBIA, Mo. – Currently, large doses of chemotherapy are required when treating certain forms of cancer, resulting in toxic side effects. The chemicals enter the body and work to destroy or shrink the tumor, but also harm vital organs and drastically affect bodily functions. Now, University of Missouri scientists have found a more efficient way of targeting prostate tumors by using gold nanoparticles and a compound found in tea leaves. This new treatment would require doses that are thousands of times smaller than chemotherapy and do not travel through the body inflicting damage to healthy areas. The study is being published in the Proceedings of the National Academy of Science.

“In our study, we found that a special compound in tea was attracted to tumor cells in the prostate,” said Kattesh Katti, curators’ professor of radiology and physics in the School of Medicine and the College of Arts and Science and senior research scientist at the MU Research Reactor. “When we combined the tea compound with radioactive gold nanoparticles, the tea compound helped ‘deliver’ the nanoparticles to the site of the tumors and the nanoparticles destroyed the tumor cells very efficiently.”

Currently, doctors treat prostate cancer by injecting hundreds of radioactive ‘seeds’ into the prostate. However, that treatment is not effective when treating an aggressive form of prostate cancer, said Cathy Cutler, research professor at the MU Research Reactor and co-author of the study. The size of the seeds and their inability to deliver effective doses hampers their ability to stop the aggressive form of prostate cancer.

In the study, the MU scientists created nanoparticles that are just the right size. Instead of hundreds of injections, the team only used one or two injections, and the nanoparticles were more likely to stay very close to the tumor sites.

Cutler and Katti have been working with colleagues Raghuraman Kannan, Anandhi Upendran, Charles Caldwell as well as others in the Department of Radiology and at the MU Research Reactor to develop and design the nanoparticles to the correct shape and size to treat prostate cancer. If the nanoparticles produced are too small, they can escape and spread; if they are made large enough, the nanoparticles will stay inside the tumor and treat it much more effectively than current methods.

“Current therapy for this disease is not effective in those patients who have aggressive prostate cancer tumors,” Cutler said. “Most of the time, prostate cancers are slow-growing; the disease remains localized and it is easily managed. Aggressive forms of the disease spread to other parts of the body, and it is the second-leading cause of cancer deaths in U.S. men. However, we believe the gold nanoparticles could shrink the tumors, both those that are slow-growing and aggressive, or eliminate them completely.”

“This treatment is successful due to the inherent properties of radioactive gold nanoparticles,” Kannan said. “First, the gold nanoparticles should be made to the correct size, and second, they have very favorable radiochemical properties, including a very short half-life.”

With a half-life of only 2.7 days, the radioactivity from the gold nanoparticles is finished within three weeks.

“Because of their size and the compound found in tea, the nanoparticles remain at the tumor sites,” Upendran said. “This helps the nanoparticles maintain a high level of effectiveness, resulting in significant tumor volume reduction within 28 days of treatment.”

In the current study, the team tested the nanoparticles on mice. Prior to human trials, the scientists will study the treatment in dogs with prostate cancer. Prostate cancer in dogs is extremely close to the human form of the disease.

“When it comes to drug discovery, MU is fortunate because we have a combination of experts in cancer research, animal modeling, isotope production and nanomedicine, and state-of-the-art research infrastructure to take discoveries from ‘the bench to the bedside’ and never leave campus,” Katti said. “For example, we developed the nanoparticles here at our research reactor, which is one of the few places in the world that produces therapeutic, clinical grade radioisotopes. We then tested the radioactive gold nanoparticles in small animals in collaboration with other radiology researchers using testing facilities located at the Harry S. Truman Veterans Hospital. Our next steps include partnering with the College of Veterinary Medicine to treat larger animals with the hopes of having human clinical trials, held on our campus, soon.”

Katti, Cutler, Kannan, Upendran and Caldwell were joined in the study by Ravi Shukla, Nripen Chanda and Ajit Zambre, all from the Department of Radiology.

Systemic delivery of therapeutic agents to solid tumors is hindered by vascular and interstitial barriers. We hypothesized that prostate tumor specific epigallocatechin-gallate (EGCg) functionalized radioactive gold nanoparticles, when delivered intratumorally (IT), would circumvent transport barriers, resulting in targeted delivery of therapeutic payloads. The results described herein support our hypothesis. We report the development of inherently therapeutic gold nanoparticles derived from the Au-198 isotope; the range of the 198Au ?-particle (approximately 11 mm in tissue or approximately 1100 cell diameters) is sufficiently long to provide cross-fire effects of a radiation dose delivered to cells within the prostate gland and short enough to minimize the radiation dose to critical tissues near the periphery of the capsule. The formulation of biocompatible 198AuNPs utilizes the redox chemistry of prostate tumor specific phytochemical EGCg as it converts gold salt into gold nanoparticles and also selectively binds with excellent affinity to Laminin67R receptors, which are over expressed in prostate tumor cells. Pharmacokinetic studies in PC-3 xenograft SCID mice showed approximately 72% retention of 198AuNP-EGCg in tumors 24 h after intratumoral administration. Therapeutic studies showed 80% reduction of tumor volumes after 28 d demonstrating significant inhibition of tumor growth compared to controls. This innovative nanotechnological approach serves as a basis for designing biocompatible target specific antineoplastic agents. This novel intratumorally injectable 198AuNP-EGCg nanotherapeutic agent may provide significant advances in oncology for use as an effective treatment for prostate and other solid tumors.

By coating radioactive gold nanoparticles with a green tea component, researchers of the University of Missouri have enhanced the delivery of the nanoparticles to tumors and their retention at the tumor site. In earlier work the researchers, led by Kattesh Katti and Cathy Cutler, showed us shrinkage of prostate cancer tumors in mice by using gold nanoparticles. However, they also found that a certain component in green tea, known as epigallocatechin-gallate (EGCg), was attracted to prostate tumor cells. By combining the nanoparticles with the tea component, the treatment will now be more efficient. The study results are published in the Proceedings of the National Academy of Sciences.

For the treatment, the size of a tumor is important in deciding whether surgical removal is an option. The smaller size can also have a positive influence on the success rate of chemotherapy and immunotherapy. In earlier research, the mice prostate tumors showed a 82% volume reduction and there were no side effects of the injected radioactive gold nanoparticles, also known as 198AuNP. The half-life of the nanoparticles is just 2.7 days and after three weeks there is no radioactivity anymore. The size of these small nanoparticles makes it possible to reach the tumor cells through the tumor vasculature, which often consist of small, fragile blood vessels.

The next step will be to acquire permission to perform clinical trials to test the effectiveness in human tumors. But before the clinical trials will start, the researchers will study the effect of the radioactive gold nanoparticles in dogs with prostate cancer.

Source : http://munews.missouri.edu/news-releases/2012/0716-gold-nanoparticles-could-treat-prostate-cancer-with-fewer-side-effects-than-chemotherapy-mu-researchers-find/

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Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures

Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures

Scientists at the research arm of General Electric have developed a heat sensor that consists of wings of the Morpho butterfly coated with single-walled carbon nanotubes. The device detects mid-wave infrared light with a precision of less than 0.06° C at a rate of about 40 Hz. GE believes the technology can be used in future medical imaging devices for visualizing inflammation and for thermal characterization of wounds.GE-butterfly-heat-sensor

Here’s more from Radislav Potyrailo, the lead scientist of the study:

Starting from our initial experiments in early 2008 and followed by more detailed studies over 2009 – 2010, we have found that scales of Morpho butterfly wings can serve as low thermal mass optical resonators and rapidly respond to temperature changes with very high sensitivity.

Our team has found that in these resonators, the optical cavity is modulated by its thermal expansion and refractive index change, resulting in conversion of infrared heat into visible iridescence changes. We further decorated the Morpho butterfly scales with single-walled carbon nanotubes and achieved heat detection with the temperature resolution of 0.02 – 0.06oC and 35 – 40 Hz response rate without the need to use a heat sink for heat removal. In the thermographic image below you can see me first holding and then breathing onto a Morpho butterfly.

The nanoscale pitch and the extremely small thermal mass of individual “pixels” of this Morphobutterfly nanostructure promise significant improvements compared to existing detectors in the cost of detectors, response speed, temperature resolution, the ability to obtain more crisp thermal images, and to have thermal images from different infrared spectral regions – all these factors being critical for the much broader acceptance of thermal imaging technologies in consumer electronic products.

Existing infrared detectors rely on complex microfabrication and thermal management methods. Here, we report an attractive platform of low-thermal-mass resonators inspired by the architectures of iridescent Morpho butterfly scales. In these resonators, the optical cavity is modulated by its thermal expansion and refractive index change, resulting in ‘wavelength conversion’ of mid-wave infrared (3–8 µm) radiation into visible iridescence changes. By doping Morpho butterfly scales with single-walled carbon nanotubes, we achieved mid-wave infrared detection with 18–62 mK noise-equivalent temperature difference and 35–40 Hz heat-sink-free response speed. The nanoscale pitch and the extremely small thermal mass of individual ‘pixels’ promise significant improvements over existing detectors. Computational analysis explains the origin of this thermal response and guides future conceptually new bio-inspired thermal imaging sensor designs.

Source:http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2011.355.html

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Therapy Cool Path Duo™ Ablation Catheter, Safire BLU Duo™

Therapy Cool Path Duo™ Ablation Catheter, Safire BLU Duo™

The FDA granted pre-market approval to St. Jude Medical for the company’s Therapy Cool Path Duo and Safire Blu Duo cardiac ablation catheters and the matching IBI1500T9-CP V1.6 generator to power them.Therapy-Cool-Path-Duo

The catheters provide cooling irrigation all around the tip from a dozen ports so that only targeted tissue is destroyed.  The system is already cleared for marketing in Europe.

Some of the features:

  • Externally irrigated ablation catheter with additional irrigation ports for more uniform cooling
  • Lower average measured tip temperature at equivalent flow rates compared to distal tip irrigation only 
  • Fewer incidences of coagulum and charring observed in preliminary study
  • All-braided construction provides uninterrupted torque transfer for more responsive handling
  • M, L, XL, and L1 curve configurations

This is a brief overview of information related to FDA’s approval to market this product. See the links below to the Summary of Safety and Effectiveness Data (SSED) and product labeling for more complete information on this product, its indications for use, and the basis for FDA’s approval.

Product Name: Therapy Cool Path Duo™ Ablation Catheter, Safire BLU Duo™ Ablation Catheter, and IBI1500T9-CP V1.6 Cardiac Ablation Generato
PMA Applicant: Irvine Biomedical, Inc., A St. Jude Medical Company
Address: 2375 Morse Ave., Irvine, CA 92614
Approval Date: January 25, 2012
Approval Letter: http://www.accessdata.fda.gov/cdrh_docs/pdf11/p110016a.pdf

What is it? The Therapy Cool Path Duo™ Ablation Catheter or the Safire BLU Duo™ Ablation Catheter is a steerable, deflectable, irrigated catheter (a long, thin, flexible tube) used to treat a certain kind of abnormal heart rhythm (arrhythmia) called typical atrial flutter by finding the source of the rhythm disturbance and destroying (ablating) small areas of the heart tissue. The catheters take energy from an external source (the IBI1500T9-CP V1.6 Cardiac Ablation Generator) to a point in the right side of the heart.

How does it work? The Therapy Cool Path Duo™ Ablation Catheter or the Safire BLU Duo™ Ablation Catheter is inserted into a blood vessel (artery or vein), usually though a site in the upper leg or neck. The catheter is manually advanced through the blood vessels until it reaches the correct location inside the heart. The tip of the catheter is moved around by a mechanism on the handle. Inside the heart, electrodes at the tip gather data that pinpoint the location of the faulty tissue in the heart (electrical mapping). Once the site is identified, the device delivers radiofrequency (RF) energy to destroy the small areas of tissue that blocks the heart’s internal electrical signals that cause the typical atrial flutter. The catheters are removed after treatment.

When is it used? The Therapy Cool Path Duo™ Ablation Catheter or the Safire BLU Duo™ Ablation Catheter, and the IBI 1500T9-CP V1.6 Cardiac Ablation Generator are used to destroy small areas in the heart that cause an abnormally fast heart beat or abnormal heart rhythm in the upper chambers (the atria) of the heart. The technical name for this kind of abnormal heart beat is typical atrial flutter.

What will it accomplish? Cardiac catheter ablation can cure typical atrial flutter and restore a normal heart rhythm, and in other cases, can reduce the frequency of episodes that a patient experiences. In a clinical study involving 188 patients, the abnormal rhythm (typical atrial flutter) was corrected in 181 patients (96%) for 7 days after treatment; and it remained corrected after 3 months in 174 patients (94.5%).

When should it not be used? The device should not be used in patients:

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POLARCUP Dual Mobility Hip System

POLARCUP Dual Mobility Hip System

It’s been implanted in Europe and other places outside the U.S. for over a decade, and the company says that the implant can deliver lower wear and dislocation rates when compared to competing devices.SN-POLARCUP

The system is specifically designed to address the challenges of treating patients – in both primary and revision cases – who are susceptible to dislocation and need enhanced stability.  Backed by 10 years of clinical history in Europe and other markets outside the US, the POLARCUP System allows surgeons to implant a smaller, constrained femoral component within a larger, anatomically sized polyethylene head, thus providing greater stability by increasing range of motion and jump distance.

February 9, 2012 – Smith & Nephew (NYSE:SNN;LSE:SN), the global medical technology business, is introducing the clinically proven POLARCUP◊ Dual Mobility Hip System to orthopaedic surgeons in the US at this year’s American Academy of Orthopaedic Surgeons (AAOS) annual meeting in San Francisco. The system is specifically designed to address the challenges of treating patients – in both primary and revision cases – who are susceptible to dislocation and need enhanced stability.

Backed by 10 years of clinical history in Europe and other markets outside the US, the POLARCUP System allows surgeons to implant a smaller, constrained femoral component within a larger, anatomically sized polyethylene head, thus providing greater stability by increasing range of motion and jump distance. “This stability philosophy is widely used in the European market where surgeons have extensive experience with dual mobility in elderly and less active patients,” says John Soto, Senior Vice President for Smith & Nephew’s Global Hip Franchise.

The POLARCUP System is a complement to the company’s clinically proven BIRMINGHAM™ Hip Resurfacing System, which provides stability and durability for the young active patient.

Source:http://global.smith-nephew.com/master/40746.htm

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