Sunday, April 24, 2011

Researchers combine active proteins with material derived from fruit fly

 

Researchers at Rice University and Texas A&M have discovered a way to pattern active proteins into bio-friendly fibers. The "eureka" moment came about because somebody forgot to clean up the lab one night.


The new work from the Rice lab of biochemist Kathleen Matthews, in collaboration with former Rice faculty fellow and current Texas A&M assistant professor Sarah Bondos, simplifies the process of making materials with fully functional proteins. Such materials could find extensive use as chemical catalysts and biosensors and in tissue engineering, for starters.


Their paper in today's online edition of details a method to combine proteins with a transcription factor derived from and then draw it into fine, strong strands that can be woven into any configuration.


Bondos and Matthews led the team that included primary author Zhao Huang and research technician Taha Salim, both of Rice, and research assistants Autumn Brawley and Jan Patterson, both of Texas A&M.


The research had its genesis while Bondos was in Matthews' Rice lab studying Ultrabithorax (Ubx), a recombinant transcription factor found in Drosophila melanogaster (the common fruit fly). This protein regulates the development of wings and legs.


"It's biodegradable, nontoxic and made of naturally occurring proteins -- though we have no reason to believe that fruit flies ever produce enough of these proteins to actually make fibers," Bondos said.


It was a surprise, then, to find that Ubx self-assembles into a film under relatively mild conditions.


"I was cleaning up in the lab one morning and I noticed what appeared to be a drop of water suspended in midair beneath a piece of equipment I was using the previous night," Bondos recalled.


It turned out the droplet was water encased in a sac of Ubx film. The sac was hanging by a Ubx fiber so thin that it was more difficult to see than a strand of a spider's web, Bondos said.


"It clued us in that this was making materials," said Matthews, Rice's Stewart Memorial Professor of Biochemistry and Cell Biology and former dean of the Wiess School of Natural Sciences.


The chance discovery prompted a 2009 paper in the journal Biomacromolecules about the material they dubbed "ultrax," a superstrong and highly elastic natural fiber.


"We found that if you put a little drop of this protein solution on a slide, the Ubx forms a film. And if you touch a needle to that film, you can draw a fiber," Matthews said. "Then we asked, What if we could incorporate other functions into these materials? Can we make chimeras?" The answer was yes, though it took ingenuity to prove.


Chimeras in the biological world contain genetically distinct cells from two or more sources. In Greek mythology, chimeras are beings with parts from multiple animals; a pig with wings, for instance, would qualify. But real chimeras are usually more subtle. On the molecular level, chimeras are proteins that are fused into a single polypeptide and can be purified as a single molecular entity.


As a proof of principle, the team used gene-fusion techniques to create chimeras by combining Ubx with fluorescent and luminescent proteins to see if they remained functional. They did. The combined materials still formed a film on water. Drawn into fibers and put under a microscope, Ubx combined with enhanced green fluorescent protein (EGFP) kept its bright green color. Ubx-mCherry was bright red, the brown protein myoglobin (from sperm whales) was brown, and luciferase glowed.


Huang was able to make patterns with strands generated by the chimeras by twisting red and green fluorescent proteins into candy cane-like tubes, or lacing them on a frame. "This patterning technique is pretty unique and very simple," said Huang, who recently defended his thesis on the subject. He said making solid materials with functional proteins often requires harsh chemical or physical processing that damages the proteins' effectiveness. But creating complex three-dimensional structures with Ubx is efficient and requires no specialized equipment.


Bondos is studying how many proteins are amenable to fusion with Ubx. "It looks like it's a fairly wide range, and even though Ubx is positively charged, both positively and negatively charged proteins can be incorporated." She said even proteins that don't directly fuse with Ubx may be able to connect through intermediary binding partners.


Bondos said the 2009 paper "showed we could make three-dimensional scaffolds. We can basically make rods and sheets and meld them together; anything you can build with Legos, we can build with Ubx."


Ubx-based materials can match the natural properties of elastin, the protein that makes skin and other tissues pliable, Bondos said. "You don't want to make a heart out of something hard, and you don't want to make a bone out of something soft," she said. "We can tune the mechanical properties by changing the diameter of the fibers."


She said functionalized Ubx offers a path to growing three-dimensional organs layer by layer. "We should be able to build something shaped like a heart, and because we can pattern the chimeras within fibers and films, we can build instructions into the material that cause cells to differentiate as muscle, nerves, vasculature and other things."


Bondos suggested the material might also be useful for replacing damaged nerves. "We should be able to stimulate cell attachment and nerve growth along the middle and factors on the ends to enhance attachment to existing nerve cells, to tie it into the patient. It really is pretty exciting."


Matthews said the ability to characterize and pattern fibers for different functions should find many uses, because enzymes, antibodies, growth factors and peptide recognition sequences can now be incorporated into biomaterials. She said sequential arrays of functional fibers for step-by-step catalysis of materials is also possible.


"You're only limited by your mechanical imagination," she said.


More information: http://onlinelibra … 067/abstract


Provided by Rice University (news : web)

A scratched coating heals itself quickly and easily, with light not heat (w/ video)

 Imagine you're driving your own new car--or a rental car--and you need to park in a commercial garage. Maybe you're going to work, visiting a mall or attending an event at a sports stadium, and you're in a rush. Limited and small available spots and concrete pillars make parking a challenge. And it happens that day: you slightly misjudge a corner and you can hear the squeal as you scratch the side of your car--small scratches, but large anticipated repair costs.


Now imagine that that you can repair these unsightly scratches yourself--quickly, easily and inexpensively. . . . or that you can go through a car wash that can detect these and other more minor scratches and fix them as the car goes through the washing garage. Fantasy? Not exactly. Not anymore. Not according to a new discovery detailed in the April 21 issue of the journal Nature, and depicted in a short video interview and simulation:

This video is not supported by your browser at this time.

A team of researchers in the United States and Switzerland have developed a polymer-based material that can heal itself with the help of a widely used type of lighting. Called "metallo-supramolecular polymers," the material is capable of becoming a supple liquid that fills crevasses and gaps left by scrapes and scuffs when placed under ultraviolet light for less than a minute and then resolidifying.

"This is ingenious and transformative research," said Andrew Lovinger, polymers program director in NSF's Division of Materials Research. "It demonstrates the versatility and power of novel to address technological issues and serve society while creating broadly applicable scientific concepts."


The team involves researchers at Case Western Reserve University in Cleveland, Ohio, led by Stuart J. Rowan; the Adolphe Merkle Institute of the University of Fribourg in Switzerland, led by Christoph Weder; and the Army Research Laboratory at Aberdeen Proving Ground in Maryland, led by Rick Beyer.


The scientists envision widespread uses in the not-so-distant future for re-healable materials like theirs, primarily as coatings for consumer goods such as automobiles, floors and furniture. While their polymers are not yet ready for commercial use, they acknowledge, they now have proved that the concept works. And with that, what happens next is up to the market place. Necessity, the mother of invention, will expand the possibilities for commercial applications.


"These polymers have a Napoleon Complex," explains lead author Stuart Rowan, a professor of macromolecular engineering and science and director of the Institute for Advanced Materials at Case Western Reserve University. "In reality they're pretty small but are designed to behave like they're big by taking advantage of specific weak molecular interactions."


"Our study is really a fundamental research study," said Christoph Weder, a professor of chemistry and materials and the director of the Adolphe Merkle Institute. "We tried to create materials that have a unique property matrix, that have unique functionality and that in principle could be very useful."


Specifically, the new materials were created by a mechanism known as supramolecular assembly. Unlike conventional polymers, which consist of long, chain-like molecules with thousands of atoms, these materials are composed of smaller molecules, which were assembled into longer, polymer-like chains using metal ions as "molecular glue" to create the metallo-supramolecular polymers.


While these metallo-supramolecular polymers behave in many ways like normal polymers, when irradiated with intense ultraviolet light the assembled structures become temporarily unglued. This transforms the originally solid material into a liquid that flows easily. When the light is switched off, the material re-assembles and solidifies again; its original properties are restored.


Using lamps such as those dentists use to cure fillings, the researchers repaired scratches in their polymers. Wherever they waved the light beam, the scratches filled up and disappeared, much like a cut that heals and leaves no trace on skin. While skin's healing process can be represented by time-lapse photography that spans several days or weeks, self-healing polymers heal in just seconds.


In addition, unlike the human body, durability of the material does not seem to be compromised by repeated injuries. Tests showed the researchers could repeatedly scratch and heal their materials in the same location.


Further, while heat has provided a means to heal materials for a long time, the use of light provides distinct advantages, says Mark Burnworth, a graduate student at Case Western Reserve University. "By using light, we have more control as it allows us to target only the defect and leave the rest of the material untouched."


The researchers systematically investigated several new polymers to find an optimal combination of mechanical properties and healing ability. They found that metal ions that drive the assembly process via weaker chemical interactions serve best as the light-switchable molecular glue.


They also found the materials that assembled in the most orderly microstructures had the best mechanical properties. But, healing efficiency improved as structural order decreased.


"Understanding these relationships is critical for allowing us improve the lifetime of coatings tailored to specific applications, like windows in abrasive environments" Beyer said.


And what's next? According to Rowan, "One of our next steps is to use the concepts we have shown here to design a coating that would be more applicable in an industrial setting."


Film director and art curator Aaron Rose was at least partially right when he said, "In the right light, at the right time, everything is extraordinary." Self-healing polymers certainly are extraordinary.


Provided by National Science Foundation (news : web)

On the way to hydrogen storage?

The car of the future could be propelled by a fuel cell powered with hydrogen. But what will the fuel tank look like? Hydrogen gas is not only explosive but also very space-consuming. Storage in the form of very dense solid metal hydrides is a particularly safe alternative that accommodates the gas in a manageable volume. As the storage tank should also not be too heavy and expensive, solid-state chemists worldwide focus on hydrides containing light and abundant metals like magnesium.


Sjoerd Harder and his co-workers at the Universities of Groningen (Netherlands) and Duisburg-Essen (Germany) now take the molecular approach. As the researchers report in the journal Angewandte Chemie, extremely small clusters of molecular magnesium hydride could be a useful model substance for more precise studies about the processes involved in hydrogen storage.


Magnesium hydride (MgH2) can release hydrogen when needed and the resulting magnesium metal reacts back again to form the hydride by pressurizing with hydrogen at a "gas station". Unfortunately, this is an idealized picture. Not only is the speed of hydrogen release/uptake excessively slow (kinetics) but it also only operates at higher temperatures (). The hydrides, the negatively charged (H-), are bound so strongly in the of magnesium cations (Mg2+) that temperatures of more than 300 °C are needed to release the .


Particularly intensive milling has made it possible to obtain nanocrystalline materials, which, on account of its larger surface, rapidly release or take up hydrogen. However, the high stability of the magnesium hydride still translates to rather high release temperatures. According to recent computer calculations, magnesium hydride clusters of only a few atoms possibly could generate hydrogen at temperatures far below 300 °C. Clusters with less than 20 Mg2+ ions are smaller than one nanometer and behave differently from the bulk material. Their hydride ions have fewer Mg2+ neighbors and are more weakly bound. However, it is extremely difficult to obtain such tiny clusters by milling. In Harder's "bottom-up" approach, magnesium hydride clusters are made by starting from molecules. The challenge is to prevent such clusters from forming very stable bulk material. Using a special ligand system, they could trap a cluster that resembles a paddle wheel made of eight Mg2+ and ten H- ions. For the first time it was shown that molecular clusters indeed release hydrogen already at the temperature of 200 °C.


This largest magnesium hydride cluster reported to date is not practical for efficient hydrogen storage but shines new light on a current problem. It is easily studied by molecular methods and as a model system could provide detailed insights in .


More information: Sjoerd Harder, Hydrogen Storage in Magnesium Hydride: The Molecular Approach, Angewandte Chemie International Edition 2011, 50, No. 18, 4156–4160, http://dx.doi.org/ … ie.201101153


Provided by Wiley (news : web)

New kid on the plasmonic block: Researchers find plasmonic resonances in semiconductor nanocrystals

 With its promise of superfast computers and ultrapowerful optical microscopes among the many possibilities, plasmonics has become one of the hottest fields in high-technology. However, to date plasmonic properties have been limited to nanostructures that feature interfaces between noble metals and dielectrics. Now, researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that plasmonic properties can also be achieved in the semiconductor nanocrystals known as quantum dots. This discovery should make the field of plasmonics even hotter.


"We have demonstrated well-defined localized surface plasmon resonances arising from p-type carriers in vacancy-doped semiconductor quantum dots that should allow for plasmonic sensing and manipulation of solid-state processes in single nanocrystals," says Berkeley Lab director Paul Alivisatos, a nanochemistry authority who led this research. "Our doped semiconductor quantum dots also open up the possibility of strongly coupling photonic and electronic properties, with implications for light harvesting, nonlinear optics, and quantum information processing."


Alivisatos is the corresponding author of a paper in the journal Nature Materials titled "Localized surface plasmon resonances arising from free carriers in doped quantum dots." Co-authoring the paper were Joseph Luther and Prashant Jain, along with Trevor Ewers.


The term "plasmonics" describes a phenomenon in which the confinement of light in dimensions smaller than the wavelength of photons in free space make it possible to match the different length-scales associated with photonics and electronics in a single nanoscale device. Scientists believe that through plasmonics it should be possible to design computer chip interconnects that are able to move much larger amounts of data much faster than today's chips. It should also be possible to create microscope lenses that can resolve nanoscale objects with visible light, a new generation of highly efficient light-emitting diodes, and supersensitive chemical and biological detectors. There is even evidence that plasmonic materials can be used to bend light around an object, thereby rendering that object invisible.


The plasmonic phenomenon was discovered in nanostructures at the interfaces between a noble metal, such as gold or silver, and a dielectric, such as air or glass. Directing an electromagnetic field at such an interface generates electronic surface waves that roll through the conduction electrons on a metal, like ripples spreading across the surface of a pond that has been plunked with a stone. Just as the energy in an electromagnetic field is carried in a quantized particle-like unit called a photon, the energy in such an electronic surface wave is carried in a quantized particle-like unit called a plasmon. The key to plasmonic properties is when the oscillation frequency between the plasmons and the incident photons matches, a phenomenon known as localized surface plasmon resonance (LSPR). Conventional scientific wisdom has held that LSPRs require a metal nanostructure , where the conduction electrons are not strongly attached to individual atoms or molecules. This has proved not to be the case as Prashant Jain, a member of the Alivisatos research group and one of the lead authors of the Nature Materials paper, explains.


"Our study represents a paradigm shift from metal nanoplasmonics as we've shown that, in principle, any nanostructure can exhibit LSPRs so long as the interface has an appreciable number of free charge carriers, either electrons or holes," Jain says. "By demonstrating LSPRs in doped quantum dots, we've extended the range of candidate materials for plasmonics to include semiconductors, and we've also merged the field of plasmonic nanostructures, which exhibit tunable photonic properties, with the field of quantum dots, which exhibit tunable electronic properties."


Jain and his co-authors made their quantum dots from the semiconductor copper sulfide, a material that is known to support numerous copper-deficient stoichiometries. Initially, the copper sulfide nanocrystals were synthesized using a common hot injection method. While this yielded nanocrystals that were intrinsically self-doped with p-type charge carriers, there was no control over the amount of charge vacancies or carriers.


"We were able to overcome this limitation by using a room-temperature ion exchange method to synthesize the copper sulfide nanocrystals," Jain says. "This freezes the nanocrystals into a relatively vacancy-free state, which we can then dope in a controlled manner using common chemical oxidants."


By introducing enough free electrical charge carriers via dopants and vacancies, Jain and his colleagues were able to achieve LSPRs in the near-infrared range of the electromagnetic spectrum. The extension of plasmonics to include semiconductors as well as metals offers a number of significant advantages, as Jain explains.


"Unlike a metal, the concentration of free charge carriers in a semiconductor can be actively controlled by doping, temperature, and/or phase transitions," he says. "Therefore, the frequency and intensity of LSPRs in dopable quantum dots can be dynamically tuned. The LSPRs of a metal, on the other hand, once engineered through a choice of nanostructure parameters, such as shape and size, is permanently locked-in."


Jain envisions quantum dots as being integrated into a variety of future film and chip-based photonic devices that can be actively switched or controlled, and also being applied to such optical applications as in vivo imaging. In addition, the strong coupling that is possible between photonic and electronic modes in such doped quantum dots holds exciting potential for applications in solar photovoltaics and artificial photosynthesis


"In photovoltaic and artificial photosynthetic systems, light needs to be absorbed and channeled to generate energetic electrons and holes, which can then be used to make electricity or fuel," Jain says. "To be efficient, it is highly desirable that such systems exhibit an enhanced interaction of light with excitons. This is what a doped quantum dot with an LSPR mode could achieve."


The potential for strongly coupled electronic and photonic modes in doped quantum dots arises from the fact that semiconductor quantum dots allow for quantized electronic excitations (excitons), while LSPRs serve to strongly localize or confine light of specific frequencies within the quantum dot. The result is an enhanced exciton-light interaction. Since the LSPR frequency can be controlled by changing the doping level, and excitons can be tuned by quantum confinement, it should be possible to engineer doped quantum dots for harvesting the richest frequencies of light in the solar spectrum.


Quantum dot plasmonics also hold intriguing possibilities for future quantum communication and computation devices.


"The use of single photons, in the form of quantized plasmons, would allow quantum systems to send information at nearly the speed of light, compared with the electron speed and resistance in classical systems," Jain says. "Doped quantum dots by providing strongly coupled quantized excitons and LSPRs and within the same nanostructure could serve as a source of single plasmons."


Jain and others in Alivsatos' research group are now investigating the potential of doped quantum dots made from other semiconductors, such as copper selenide and germanium telluride, which also display tunable plasmonic or photonic resonances. Germanium telluride is of particular interest because it has phase change properties that are useful for memory storage devices.


"A long term goal is to generalize plasmonic phenomena to all doped quantum dots, whether heavily self-doped or extrinsically doped with relatively few impurities or vacancies," Jain says.


This research was supported by the DOE Office of Science.


Story Source:


The above story is reprinted (with editorial adaptations ) from materials provided by DOE/Lawrence Berkeley National Laboratory.

Journal Reference:

Joseph M. Luther, Prashant K. Jain, Trevor Ewers, A. Paul Alivisatos. Localized surface plasmon resonances arising from free carriers in doped quantum dots. Nature Materials, 2011; DOI: 10.1038/nmat3004

Biophysicist targeting IL-6 to halt breast, prostate cancer

An Ohio State biophysicist used a supercomputer to search thousands of molecular combinations for the best configuration to block a protein that can cause breast or prostate cancer.


Chenglong Li, Ph.D., an assistant professor of medicinal chemistry and pharmacognosy at The Ohio State University (OSU), is leveraging a powerful computer cluster at the Ohio Supercomputer Center (OSC) to develop a drug that will block the small protein molecule Interleukin-6 (IL-6). The body normally produces this immune-response messenger to combat infections, burns, traumatic injuries, etc. Scientists have found, however, that in people who have cancer, the body fails to turn off the response and overproduces IL-6.


"There is an inherent connection between inflammation and cancer," explained Li. "In the case of breast cancers, a medical review systematically tabulated IL-6 levels in various categories of cancer patients, all showing that IL-6 levels elevated up to 40-fold, especially in later stages, metastatic cases and recurrent cases."


In 2002, Japanese researchers found that a natural, non-toxic molecule created by marine bacteria -- madindoline A (MDL-A) -- could be used to mildly suppress the IL-6 signal. Unfortunately, the researchers also found the molecule wouldn't bind strongly enough to be effective as a cancer drug and would be too difficult and expensive to synthesize commercially. And, most surprisingly, they found the bacteria soon mutated to produce a different, totally ineffectual compound. Around the same time, Stanford scientists were able to construct a static image of the crystal structure of IL-6 and two additional proteins.


Li recognized the potential of these initial insights and partnered last year with an organic chemist and a cancer biologist at OSU's James Cancer Hospital to further investigate, using an OSC supercomputer to construct malleable, three-dimensional color simulations of the protein complex.


"The proximity of two outstanding research organizations -- the James Cancer Hospital and OSC -- provide a potent enticement for top medical investigators, such as Dr. Li, to conduct their vital computational research programs at Ohio State University," said Ashok Krishnamurthy, interim co-executive director of OSC.


"We proposed using computational intelligence to re-engineer a new set of compounds that not only preserve the original properties, but also would be more potent and efficient," Li said. "Our initial feasibility study pointed to compounds with a high potential to be developed into a non-toxic, orally available drug."


Li accessed 64 nodes of OSC's Glenn IBM 1350 Opteron cluster to simulate IL-6 and the two additional helper proteins needed to convey the signal: the receptor IL-6R and the common signal-transducing receptor GP130. Two full sets of the three proteins combine to form a six-sided molecular machine, or "hexamer," that transmits the signals that will, in time, cause cellular inflammation and, potentially, cancer.


Li employed the AMBER (Assisted Model Building with Energy Refinement) and AutoDock molecular modeling simulation software packages to help define the interactions between those proteins and the strength of their binding at five "hot spots" found in each half of the IL-6/IL-6R/GP130 hexamer.


By plugging small molecules, like MDL-A, into any of those hot spots, Li could block the hexamer from forming. So, he examined the binding strength of MDL-A at each of the hexamer hotspots, identifying most promising location, which turned out to be between IL-6 and the first segment, or modular domain (D1), of the GP130.


To design a derivative of MDL-A that would dock with D1 at that specific hot spot, Li used the CombiGlide screening program to search through more than 6,000 drug fragments. So far, he has identified two potential solutions by combining the "top" half of the MDL-A molecule with the "bottom" half of a benzyl molecule or a pyrazole molecule. These candidates preserve the important binding features of the MDL-A, while yielding molecules with strong molecular bindings that also are easier to synthesize than the original MDL-A.


"While we didn't promise to have a drug fully developed within the two years of the project, we're making excellent progress," said Li. "The current research offers us an exciting new therapeutic paradigm: targeting tumor microenvironment and inhibiting tumor stem cell renewal, leading to a really effective way to overcome breast tumor drug resistance, inhibiting tumor metastasis and stopping tumor recurrence."


While not yet effective enough to be considered a viable drug, laboratory tests on tissue samples have verified the higher potency of the derivatives over the original MDL-A. Team members are preparing for more sophisticated testing in a lengthy and carefully monitored evaluation process.


Li's project is funded by a grant from the Department of Defense (CDMRP grant number BC095473) and supported by the award of an OSC Discovery Account. The largest funding areas of Congressionally Directed Medical Research Programs (CDMRP) are breast cancer, prostate cancer and ovarian cancer. Another Defense CDMRP grant involving Li supports a concurrent OSU investigation of the similar role that IL-6 plays in causing prostate cancer. Those projects are being conducted in collaboration with Li's Medicinal Chemistry colleague, Dr. James Fuchs, as well as Drs. Tushar Patel, Greg Lesinski and Don Benson at OSU's College of Medicine and James Cancer Hospital, and Dr. Jiayuh Lin at Nationwide Children's Hospital in Columbus.


"In addition to leading the center's user group this year, the number and depth of Dr. Li's computational chemistry projects have ranked him one of our most prolific research clients," Krishnamurthy noted.


Story Source:


The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Ohio Supercomputer Center.

Biologically inspired catalysts being developed

 NJIT Associate Professor Sergiu M. Gorun is leading a research team to develop biologically-inspired catalysts. The work is based on organic catalytic framework made sturdy by the replacement of carbon-hydrogen bonds with a combination of aromatic and aliphatic carbon-fluorine bonds. Graduate students involved with this research recently received first place recognition at the annual NJIT Dana Knox student research showcase.


The newest focus of Gorun's research has been the cobalt complex as a catalyst for which the known degradation pathways appear to have been suppressed. Their work appeared recently online in Dalton Transactions. Similar to a previous publication, this recent one addresses an important industrial process, the "sweetening" of petroleum products by the transformation of smelly and corrosive thiols into disulfides. The extreme electronic deficiency of the new catalyst metal center allows it to process molecules that are not reactive in the presence of regular catalysts that perform this chemistry industrially.


Two years ago Gorun and his team reported that the related zinc perfluoroalkylated phthalocyanine, a molecule resembling the porphyrin core of several heme enzymes, exhibit highly-efficient photochemical oxygenation of an organic substrate. This was of great interest to the fragrance industry.


Concurrently, the unusual properties of Gorun's new materials are explored in parallel in constructing surface coatings, an area in which Gorun was awarded US patent 7,670,684. Several publications describe the properties of the new coatings.


The Department of Defense and National Science Foundation have supported this work. Gorun will be an invited speaker in a symposium about advances in phthalocyanines and related macrocycles to be held July of 2012 at the 7th International Conference on Porphyrins and Phthalocyanines, held in Jeju Island, South Korea.


Story Source:


The above story is reprinted (with editorial adaptations ) from materials provided by New Jersey Institute of Technology, via EurekAlert!, a service of AAAS.

Journal Reference:

Andrei Loas, Robert Gerdes, Yongyi Zhang, Sergiu M. Gorun. Broadening the reactivity spectrum of a phthalocyanine catalyst while suppressing its nucleophilic, electrophilic and radical degradation pathways. Dalton Transactions, 2011; DOI: 10.1039/C1DT10458F