The Technion Researchers Find to NanoParticles may Threaten Heart

Nanoparticles, extremely tiny particles measured in billionths of a meter, are increasingly everywhere, and especially in biomedical products. Their toxicity has been researched in general terms, but now a team of Israeli scientists has for the first time found that exposure nanoparticles (NPs) of silicon dioxide (SiO2) can play a major role in the development of cardiovascular diseases when the NP cross tissue and cellular barriers and also find their way into the circulatory system. Their study is published in the December 2014 issue of Environmental Toxicology.

Prof. Michael Aviram
The research team was comprised of scientists from the Technion Rappaport Faculty of Medicine, Rambam Medical Center, and the Center of Excellence in Exposure Science and Environmental Health (TCEEH).

“Environmental exposure to nanoparticles is becoming unavoidable due to the rapid expansion of nanotechnology,” says the study’s lead author, Prof. Michael Aviram, of the Technion Faculty of Medicine, “This exposure may be especially chronic for those employed in research laboratories and in high tech industry where workers handle, manufacture, use and dispose of nanoparticles. Products that use silica-based nanoparticles for biomedical uses, such as various chips, drug or gene delivery and tracking, imaging, ultrasound therapy, and diagnostics, may also pose an increased cardiovascular risk for consumers as well.”

In this study, researchers exposed cultured laboratory mouse cells resembling the arterial wall cells to NPs of silicon dioxide and investigated the effects. SiO2 NPs are toxic to and have significant adverse effects on macrophages. a type of white blood cell that take up lipids, leading to atherosclerotic lesion development and its consequent cardiovascular events, such as heart attack or stroke. Macrophages accumulation in the arterial wall under atherogenic conditions such as high cholesterol, triglycerides, oxidative stress – are converted into lipids, or laden “foam cells” which, in turn, accelerate atherosclerosis development.

“Macrophage foam cells accumulation in the arterial wall are a key cell type in the development of atherosclerosis, which is an inflammatory disease” says co-author Dr. Lauren Petrick. “The aims of our study were to gain additional insight into the cardiovascular risk associated with silicon dioxide nanoparticle exposure and discover the mechanisms behind Si02’s induced atherogenic effects on macrophages. We also wanted to use nanoparticles as a model for ultrafine particle (UFP) exposure as cardiovascular disease risk factors.”

Both NPs and UFPs can be inhaled and induce negative biological effects. However, until this study, their effect on the development of atherosclerosis has been largely unknown. Here, researchers have discovered for the first time that the toxicity of silicon dioxide nanoparticles has a “significant and substantial effect on the accumulation of triglycerides in the macrophages,” at all exposure concentrations analyzed, and that they also “increase oxidative stress and toxicity.”

A recent update from the American Heart Association also suggested that “fine particles” in air pollution leads to elevated risk for cardiovascular diseases. However, more research was needed to examine the role of “ultrafine particles” (which are much smaller than “fine particles”) on atherosclerosis development and cardiovascular risk.

“The number of nano-based consumer products has risen a thousand fold in recent years, with an estimated world market of $3 trillion by the year 2020,” conclude the researchers. “This reality leads to increased human exposure and interaction of silica-based nanoparticles with biological systems. Because our research demonstrates a clear cardiovascular health risk associated with this trend, steps need to be taken to help ensure that potential health and environmental hazards are being addressed at the same time as the nanotechnology is being developed.

The Technion-Israel Institute of Technology is a major source of the innovation and brainpower that drives the Israeli economy, and a key to Israel’s renown as the world’s “Start-Up Nation.” Its three Nobel Prize winners exemplify academic excellence. Technion people, ideas and inventions make immeasurable contributions to the world including life-saving medicine, sustainable energy, computer science, water conservation and nanotechnology. The Joan and Irwin Jacobs Technion-Cornell Institute is a vital component of Cornell NYC Tech, and a model for graduate applied science education that is expected to transform New York City’s economy.

American Technion Society (ATS) donors provide critical support for the Technion—more than $1.95 billion since its inception in 1940. Based in New York City, the ATS and its network of chapters across the U.S. provide funds for scholarships, fellowships, faculty recruitment and chairs, research, buildings, laboratories, classrooms and dormitories, and more.

Source: ATS

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Competing in Robotics

RoboCup Junior is an international competition for the construction and programming of robots. It’s a part of the major RoboCup initiative – one of the biggest robot competitions in the world, with thousands of participants from over 40 countries.

Linköping students are organising the Swedish qualifying rounds for RoboCup Junior (in Swedish Junior-VM i robotik) where children and young people up to the age of 19 can take part. The winners get to represent Sweden in the 2015 international finals, which will be held in Hefei, China.

Mr Löfgren, who is in the fourth year of his studies for a master’s in Engineering Physics and Electronics, is a previous participant in the competition and current project leader for the RoboCup Junior finals in Linköping. He is the youngest ever member of the technical committee, which is mainly composed of eminent researchers and teachers.

“RoboCup Junior has been held in Sweden since 2009. I took part the very first year, won

the competition, and got to represent Sweden at the world championship in Austria.”

Since then, Mr Löfgren has won many competitions, in which he got to do things such as represent Sweden in Singapore and compete in the World Championships in Istanbul.

“After that I was too old; in 2012 I became team leader for one team and a judge for the national competition. I was also appointed to the international organizing committee of RoboCup Junior Rescue, and the technical committee.”

He has also been involved on the international stage, for example in Brazil where he wrote the rules for the next year’s competition. He was also team leader at the World Championships in Eindhoven. In 2013, Mr Löfgren started a student society whose aim was to organise RoboCup Junior in Sweden. The FIA student association (the Intelligent Autonomous Systems Society) grew, and now RoboCup Junior is just one of many events the society organises each year.

How do you select the participants?

“I was chosen as project leader for the competition by the board of the FIA, and then I appointed a project team of five people to help me plan and organise the competition in Linköping.”

The FIA is also organising a competition for university students and the public in conjunction with RoboCup Junior, so that more people can get the chance to compete with robots.

“I love to compete and I’ve competed in knowledge for a very long time,” Mr Löfgren says.

Robots around the dinner tableWhat has your involvement given you in practical terms?
“Being involved with robots has given me a great advantage in my studies here at the university. I have learned a great deal not only about electronics, programming and construction, but also about leadership and other cultures on my many travels, as well as how to collaborate on international projects.”

Mr Löfgren thinks it’s great to see how older researchers and professors listen to what he has to say, and he is looking forward to the next cooking competition that will be held in Madrid in November. It will consist of seeing how well the robots manage to cook tomato soup, write a shopping list and find and switch off a stove hob that has been left on.

He has already been offered jobs, but turned them down as he wants to finish his studies first before he starts his “real” working life.

Developing robots for space, robots that explore other planets and robots that work in caring for the elderly by doing all the heavy work so that staff can devote time to their personal contact with elderly people, are examples of dream jobs.

“I want to develop the technology of tomorrow and I’m open to everything that has to do with the development of technology. As I have worked with robots for 15 years, they are very dear to my heart.”

Text: Zen Dinah, student reporter
Photo: Julius Jeuthe, student photographer

Source: Linköping University

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VCU researcher receives NSF grant to extend lifespan of Li-ion batteries, make them more environmentally friendly

Arunkumar Subramanian, Ph.D., an assistant professor in the Department of Mechanical and Nuclear Engineering in the School of Engineering, will use the grant to deliver technological advances that reduce the cost and carbon footprint of Li-ion batteries by extending their lifespan.

A Virginia Commonwealth University professor has received a five-year, $505,000 award from the National Science Foundation to make lithium-ion batteries — which power electric vehicles and portable electronic devices — far more efficient, sustainable and environmentally friendly.

Arunkumar Subramanian, Ph.D., an assistant professor in the Department of Mechanical and Nuclear Engineering in the School of Engineering, will use the grant to deliver technological advances that reduce the cost and carbon footprint of Li-ion batteries by extending their lifespan. He will simultaneously research alternative battery materials that are both nontoxic and more abundant.

"If you look at electrical energy storage solutions that are used in today's electric vehicles and portable electronic devices, you would find that lithium-ion batteries is the technology of choice," Subramanian said. "But if you want to make this technology truly sustainable and environmentally benign, then we need to be able to reduce its cost, as well as its carbon footprint as compared to energy derived from other sources such as fossil fuels."

Subramanian plans to address these goals by extending the lifespan of Li-ion batteries made from sustainable electrode materials, which are derived from the nontoxic manganese oxide material system.

“This project is likely to result in transformative innovations for the battery industry, which in turn will impact a whole host of consumer devices and cars.”

"This project is likely to result in transformative innovations for the battery industry, which in turn will impact a whole host of consumer devices and cars," said Ram Gupta, Ph.D., a professor and associate dean for research in the School of Engineering.

An overarching goal of the project, "Sustainable Solutions for Li-ion Batteries through Cycle-Life Improvements in Nanostructured, 'Green' Cathodes," is to maximize the environmental benefits of electric cars.

"Electric vehicles are one alternative for reducing fossil fuel consumption and greenhouse gas production for sustainable transportation needs," according to the project's abstract. "Electric vehicles require rechargeable batteries that balance the electrical energy storage and power delivery needs, and these batteries must have a lifespan sufficient to reduce cost and achieve true carbon footprint reduction. Furthermore, batteries should be manufactured from sustainable materials to minimize environmental impact."

The award is from National Science Foundation's Faculty Early Career Development (CAREER) Program, which provides the foundation's most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations.

A key aspect of Subramanian's project will be to create batteries in which the team will isolate a single manganese oxide nanowire as the battery's functional electrode element. These nanowire materials are synthesized and supplied by Ekaterina Pomerantseva, Ph.D., a research collaborator and materials science professor at Drexel University.

"Now, the reason we want to do this with nanomaterials is because the small form-factors have the potential to facilitate high charge-storage capacities at fast battery charging and discharging rates,” Subramanian said. “The use of a single nanowire battery electrode is motivated by its ability to reveal the electrochemically correlated structure-property-performance relationships in the material system with atomic-to-nanoscale scale resolution, thereby enabling the optimization of the host crystal to lithium intercalation."

The "nanowires" are one-dimensional constructs that have a diameter of roughly 10 nanometers to 20 nanometers. A nanometer is one billionth of a meter.

"If you were to compare these nanowires to, say, a human hair, [the hair would be] about 10,000 times larger than these nanowires in diameter," Subramanian said.

“If you were to compare these nanowires to, say, a human hair, [the hair would be] about 10,000 times larger than these nanowires in diameter.”

These nanowire electrodes will be tested using a co-integrated device created on silicon chips, which includes a lithium cell and a nanoelectromechanical resonator for charge capacity measurements. The functional components of this device are contained within an ultra-small footprint of a square micron, representing the current state-of-the-art for nanosystems made from synthetic constructs.

Much of the testing with the devices is being conducted at Nanomaterials Core Characterization Facility, a research core facility of the VCU Office of Research and located in the Institute for Engineering and Medicine.

As part of the project, Subramanian's team will also develop a "nano energy" workshop for high school teachers taking part in the NanoFellows Institute organized by the MathScience Innovation Center in Richmond.

"We'll have the teachers visit our lab and do hands-on experiments with nano-enabled batteries and then they would take some of these samples for demonstrations in their classrooms during the school year," he said.

The researchers will also implement "nanobot" workshops and summer research internship programs, which are focused on the use of nanorobots inside electron microscopes, targeting Summer Regional Governor’s School student participants at the MathScience Innovation Center.

The researchers will also introduce this "nano energy" module to high school students taking part in the Richmond Area Program for Minorities in Engineering, a nonprofit organization that works to increase diversity in science and engineering.

Source: VCU

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An Advanced Method of DNA Nanostructure Formation Developed

Figure 1: Uni-molecular magnetic tweezers orchestrating the DNA nanostructure formation

Professor Tae-Young Yoon’s research team from the Department of Physics at KAIST has developed a new method to form DNA nanostructures by using magnetic tweezers to observe and to induce the formation of the structure in real time.

Unlike traditional designs of "DNA origami" which relies on thermal or chemical annealing methods, the new technology utilizes a completely different dynamic in DNA folding. This allows the folding to be done within only ten minutes.

Developed in 2006, the "DNA origami" allows a long skeleton of DNA to be folded into an arbitrary structure by using small stapler DNA pieces. This has been a prominent method in DNA nanotechnology.
 

Figure 2: The evolution of DNA nanostructure formation using magnetic tweezers. The DNA nanostructure with a 21-nanometer size was formed in about eight minutes.

However, the traditional technology which adopts thermal processes could not control the DNA formation during the folding because every interaction among DNAs occurs simultaneously. Thus, the thermal processes, which take dozens of hours to complete, had to be repeated multiple times in order to find the optimal condition.

The research team designed a DNA folding using uni-molecular magnetic tweezers that applied force to a single DNA molecule while measuring the state of the DNA. Through this technology, they were able to induce the formation of DNA nanostructure and observe it at the same time.

During high temperature heat treatment, the first stage of conventional thermal processes, the internal structure of the long skeleton DNA untangles. To induce such state, after attaching one side of the skeleton DNA to the surface of glass and the other side to a magnetic material, the team unfolded the internal structure of the DNA by pulling the two sides apart with magnetic force.

Unlike the conventional thermal processes, this method lets the stapler DNA swiftly adhere to the skeleton DNA within a minute because the sites are revealed at room temperature.

After the stapler pieces connected to the skeleton, the team removed the magnetic force. Next, the structure folded through self-assembly as the stapler DNAs stuck to different sites on the skeleton DNA.

Professor Yoon said, “With the existing thermal methods, we could not differentiate the reactions of the DNA because the response of each DNA pieces mutually interacted with each other.” He added that “Using the magnetic tweezers, we were able to sort the process of DNA nanostructure formation into a series of reactions of DNA molecules that are well known, and shorten the time taken for formation in only ten minutes.”

He commented, “This nanostructure formation method will enable us to create more intricate and desirable DNA nanostructures by programming the folding of DNA origami structures.”

Conducted by Dr. Woori Bae under the guidance of Professor Yoon, the research findings were published online in the December 4th issue of Nature Communications.


Source: KAIST

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Bio-inspired bleeding control: Synthesized platelet-like nanoparticles created

Artist's rendering of synthetic platelets. Credit: Peter Allen illustration

Stanching the free flow of blood from an injury remains a holy grail of clinical medicine. Controlling blood flow is a primary concern and first line of defense for patients and medical staff in many situations, from traumatic injury to illness to surgery. If control is not established within the first few minutes of a hemorrhage, further treatment and healing are impossible.

At UC Santa Barbara, researchers in the Department of Chemical Engineering and at Center for Bioengineering (CBE) have turned to the human body's own mechanisms for inspiration in dealing with the necessary and complicated process of coagulation. By creating nanoparticles that mimic the shape, flexibility and surface biology of the body's own platelets, they are able to accelerate natural healing processes while opening the door to therapies and treatments that can be customized to specific patient needs.

"This is a significant milestone in the development of synthetic platelets, as well as in targeted drug delivery," said Samir Mitragotri, CBE director, who specializes in targeted therapy technologies. Results of the researchers' findings appear in the current issue of the journal ACS Nano.

The process of coagulation is familiar to anyone who has suffered even the most minor of injuries, such as a scrape or paper cut. Blood rushes to the site of the injury, and within minutes the flow stops as a plug forms at the site. The tissue beneath and around the plug works to knit itself back together and eventually the plug disappears.

But what we don't see is the coagulation cascade, the series of signals and other factors that promote the clotting of blood and enable the transition between a free-flowing fluid at the site and a viscous substance that brings healing factors to the injury. Coagulation is actually a choreography of various substances, among the most important of which are platelets, the blood component that accumulates at the site of the wound to form the initial plug.

"While these platelets flow in our blood, they're relatively inert," said graduate student researcher Aaron Anselmo, lead author of the paper. As soon as an injury occurs, however, the platelets, because of the physics of their shape and their response to chemical stimuli, move from the main flow to the side of the blood vessel wall and congregate, binding to the site of the injury and to each other. As they do so, the platelets release chemicals that "call" other platelets to the site, eventually plugging the wound.

But what happens when the injury is too severe, or the patient is on anti-coagulation medication, or is otherwise impaired in his or her ability to form a clot, even for a modest or minor injury?

That's where platelet-like nanoparticles (PLNs) come in. These tiny, platelet-shaped 

particles that behave just like their human counterparts can be added to the blood flow to supply or augment the patient's own natural platelet supply, stemming the flow of blood and initiating the healing process, while allowing physicians and other caregivers to begin or continue the necessary treatment. Emergency situations can be brought under control faster, injuries can heal more quickly and patients can recover with fewer complications.

"We were actually able to render a 65 percent decrease in bleeding time compared to no treatment," said Anselmo.

According to Mitragotri, the key lies in the PLNs' mimicry of the real thing. By imitating the shape and flexibility of natural platelets, PLNs can also flow to the injury site and congregate there. With surfaces functionalized with the same biochemical motifs found in their human counterparts, these PLNs also can summon other platelets to the site and bind to them, increasing the chances of forming that essential plug. In addition, and very importantly, these platelets are engineered to dissolve into the blood after their usefulness has run out. This minimizes complications that can arise from emergency hemostatic procedures.

"The thing about hemostatic agents is that you have to intervene to the right extent," said Mitragotri. "If you do too much, you cause problems. If you do too little, you cause problems."

These synthetic platelets also let the researchers improve on nature. According to Anselmo's investigations, for the same surface properties and shape, nanoscale particles can perform even better than micron-size platelets. Additionally, this technology allows for customization of the particles with other therapeutic substances -- medications, therapies and such -- that patients with specific conditions might need.

"This technology could address a plethora of clinical challenges," said Dr. Scott Hammond, director of UCSB's Translational Medicine Research Laboratories. "One of the biggest challenges in clinical medicine right now -- which also costs a lot of money -- is that we're living longer and people are more likely to end up on blood thinners. When an elderly patient presents at a clinic, it's a huge challenge because you have no idea what their history is and you might need an intervention."

With optimizable PLNs, physicians would be able to strike a finer balance between anticoagulant therapy and wound healing in older patients, by using nanoparticles that can target where clots are forming without triggering unwanted bleeding. In other applications, bloodborne pathogens and other infectious agents could be minimized with antibiotic-carrying nanoparticles. Particles could be made to fulfill certain requirements to travel to certain parts of the body -- across the blood-brain barrier, for instance -- for better diagnostics and truly targeted therapies.

Additionally, according to the researchers, these synthetic platelets cost relatively less, and have a longer shelf life than do human platelets -- a benefit in times of widespread emergency or disaster, when the need for these blood components is at its highest and the ability to store them onsite is essential.

Further research into PLNs will involve investigations to see how well the technology and synthesis can scale up, as well as assessments into the more practical matters involved in translating the technology from the lab to the clinic, such as manufacturing, storage, sterility and stability as well as pre-clinical and clinical testing.

Source: University of California - Santa Barbara

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Engineers develop new sensor to detect tiny individual nanoparticles

The image shows arrays of self-referenced and self-heterodyned Whispering-Gallery Raman microlasers for single nanoparticle detection. A "pump" laser generates a single Raman lasing mode inside the silica resonators. Upon landing of a nanoparticle on the resonator, Raman laser circulating inside the resonator undergo mode splitting leading to two new lasing modes in different colors. Monitoring the changes in the color difference (frequency difference) enables detecting and measuring of nanoparticles with single particle resolution. Credit: J. Zhu, B. Peng, S.K. Ozdemir, L. Yang

Nanoparticles, engineered materials about a billionth of a meter in size, are around us every day. Although they are tiny, they can benefit human health, as in some innovative early cancer treatments, but they can also interfere with it through viruses, air pollution, traffic emissions, cosmetics, sunscreen and electronics.

A team of researchers at Washington University in St. Louis, led by Lan Yang, PhD, the Das Family Career Development Associate Professor in Electrical & Systems Engineering, and their collaborators at Tsinghua University in China have developed a new sensor that can detect and count nanoparticles, at sizes as small as 10 nanometers, one at a time. The researchers say the sensor could potentially detect much smaller particles, viruses and small molecules.

The research appears in the Proceedings of the National Academy of Sciences online Early Edition Sept. 1, 2014.

Yang and her colleagues have created the Raman microlaser sensor in a silicon dioxide chip to find individual nanoparticles without the need to "dope" the chip with chemicals called rare-earth ions to provide optical gain for the microlaser. Incorporating additions to the microresonator creates the need for more processing steps and increased costs and invites biocompatibility risks. In addition, the use of rare-earth ions requires specific "pump" lasers matching the energy transitions of the ions to generate optical gain, so for different rare-earth ions, different pump lasers must be used. Using the Raman process loosens the requirement of specific wavelength bands for pump lasers because Raman gain can be obtained using pump at any wavelength band, Yang says.

"This gives us the advantage of using the same dopant-free sensor at different sensing environments by tailoring the lasing frequency for the specific environment, for example, at the band where the environment has minimum absorption, and for the properties of the targeted nanoparticles by just changing the wavelength of the pump laser," says Sahin Kaya Ozdemir, PhD, a research scientist in Yang's group and the first author of the paper.

Yang's team integrated Raman lasing in a silica microcavity with the mode splitting technique pioneered by her group to develop a new, powerful sensor that more readily detects nanoparticles. The technology will benefit the electronics, acoustics, biomedical, plasmonics, security and metamaterials fields.

Yang's microsensor is in a class called whispering gallery mode resonators (WGMRs) because it works similarly to the renowned whispering gallery in London's St. Paul's Cathedral, where a person on one side of the dome can hear a message spoken to the wall by another person on the other side. Yang's device does much the same thing with light frequencies rather than audible ones.

One of the main differences between early resonators and the novel resonator, known as a morphology dependent resonator, was they didn't use mirrors to reflect light. Yang's WGMR is an actual mini-laser that supports "frequency degenerate modes," patterns of excitation inside the mini-laser's doughnut-shaped ring that are of the same frequency. One portion of light beamed by the Raman laser goes counterclockwise, another goes clockwise. When a particle lands on the ring and scatters energy between these modes, the single Raman lasing line splits into two lasing lines with different frequencies.

When a Raman laser beam is generated in the resonator, it likely will encounter a particle, such as a virus nanoparticle, on the circle. When the beam initially sees the particle, the beam splits into two, generating two lasing lines that serve as reference to the other to form a self-referenced sensing technique.

"Our new sensor differs from the earlier whispering gallery sensors in that it relies on Raman gain, which is inherent in silica, thereby eliminating the need for doping the microcavity with gain media, such as rare-earth ions or optical dyes, to boost detection capability," Ozdemir says. "This new sensor retains the biocompatibility of silica and could find widespread use for sensing in biological media."

"It doesn't matter what kind of wavelength is used, once you have the Raman laser circulating inside and there is a molecule sitting on the circle, when the beam sees the particle it will scatter in all kinds of directions," Yang says. "Initially you have a counterclockwise mode, then a clockwise mode, and by analyzing the characterization of the two split modes, we confirm the detection of nanoparticles."

In addition to the demonstration of Raman microlasers for particle sensing, the team says their work shows the possibility of using intrinsic gain mechanisms, such as Raman and parametric gain, instead of optical dyes, rare-earth ions or quantum dots, for loss compensation in optical and plasmonic systems where dissipation hinders progress and limits applications.

Source: Washington University in St. Louis

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Mysteries of 'molecular machines' revealed: Phenix software uses X-ray diffraction spots to produce 3-D image

This is a membrane protein called cysZ, imaged in 3 dimensions with Phenix software using data that could not previously be analyzed. Credit: Los Alamos National Laboratory

Scientists are making it easier for pharmaceutical companies and researchers to see the detailed inner workings of molecular machines.

'Inside each cell in our bodies and inside every bacterium and virus are tiny but complex protein molecules that synthesize chemicals, replicate genetic material, turn each other on and off, and transport chemicals across cell membranes,' said Tom Terwilliger, a Los Alamos National Laboratory scientist.

'Understanding how all these machines work is the key to developing new therapeutics, for treating genetic disorders, and for developing new ways to make useful materials.'

To understand how a machine works you have to be able to see how it is put together and how all its parts fit together. This is where the Los Alamos scientists come in. These molecular machines are very small: a million of them placed side by side would take up less than an inch of space. Researchers can see them however, using x-rays, crystals and computers. Researchers produce billions of copies of a protein machine, dissolve them in water, and grow crystals of the protein, like growing sugar crystals except that the machines are larger than a sugar molecule.

Then they shine a beam of X-rays at a crystal and measure the brightness of each of the thousands of diffracted X-ray spots that are produced. Then researchers use the powerful Phenix software, developed by scientists at Los Alamos, Lawrence Berkeley National Laboratory, Duke and Cambridge universities, to analyze the diffraction spots and produce a three-dimensional picture of a single protein machine. This picture tells the researchers exactly how the protein machine is put together.

The 3-D Advance

Recently Los Alamos scientists worked with their colleagues at LBNL and Cambridge University to make it even easier to visualize a molecular machine. In a report in the journal Nature Methods this month, Los Alamos scientists and their team show that they can obtain three-dimensional pictures of molecular machines using X-ray diffraction spots that could not previously be analyzed.

Some molecular machines contain a few metal atoms or other atoms that diffract X-rays differently than the carbon, oxygen, nitrogen, and hydrogen atoms that make up most of the atoms in a protein. The Phenix software finds those metal atoms first, and then uses their locations to find all the other atoms. For most molecular machines, however, metal atoms have to be incorporated into the machine artificially to make this all work.

The major new development to which Los Alamos scientists have contributed was showing that powerful statistical methods could be applied to find metal atoms even if they do not scatter X-rays very differently than all the other atoms. Even metal atoms such as sulfur that are naturally part of almost all proteins can be found and used to generate a three-dimensional picture of a protein. Now that it will often be possible to see a three-dimensional picture of a protein without artificially incorporating metal atoms into them, many more molecular machines can be studied.

Cracking the Cascade

Molecular machines that have recently been seen in three-dimensional detail include a 'huge' molecular machine called Cascade that was reported in the journal Science this summer. The Cascade machine is present in bacteria and can recognize DNA that comes from viruses that infect the bacteria. The Cascade machine is made up of 11 proteins and an RNA molecule and looks like a seahorse, with the RNA molecule winding through the whole 'body' of the seahorse. If a foreign piece of DNA in the bacterial cell is complementary to part of the RNA molecule then another specialized machine can come by and chop up the foreign DNA, saving the bacterium from infection.

Los Alamos and Cambridge University scientists who were developing the Phenix software were part of the team that visualized this protein machine for the first time. The Phenix software has been used to determine the three-dimensional shapes of over 15,000 different protein machines and has been cited by over 5000 scientific publications.

Source: DOE/Los Alamos National Laboratory

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Nanoparticle research could enhance oil recovery, tracing of fracking fluid

William Sanford and Vivian Li.
Credit: Image courtesy of Colorado State University

Two Colorado State University researchers are examining how nanoparticles move underground, knowledge that could eventually help improve recovery in oil fields and discover where hydraulic fracking chemicals travel.

Vivian Li, assistant professor in the Department of Design and Merchandising, and William Sanford, associate professor in the Department of Geosciences, are trying to find patterns in how certain nanoparticles move underground. If successful, they could train the nanoparticles to indicate when specific chemicals are present in the subsurface, including those found in underground water deposits. These modified "smart" nanoparticles, known as tracers, could sense high pH levels or the presence of hydraulic fracking chemicals.

In the initial phase of their research, funded through a grant from the CSU Water Center, Li and Sanford are testing their specially engineered carbon nanoparticle to see how it moves through the ground. Once they understand how the particle travels through a number of subsurface environments, it could eventually be used to search for chemicals in some of Earth's most hostile underground environments.

"We also want to see how nanoparticles affect the composition of the natural environment and how certain elements found in the ground alter the composition of the nanoparticle," explained Li.
Temperature, water saturation, and the physical and chemical composition of the soil are the primary factors that can alter the movement of nanoparticles.

Hydraulic fracturing of wells has caused a political firestorm in recent years, as Colorado residents have questioned the health and safety risks of injecting chemicals into the ground to free oil and natural gas. There is still debate about whether these chemicals are harming the environment, and some question where the chemicals go after injection, fearing they may be contaminating groundwater supplies.

Using tracers, Li and Sanford theorize they could inject the particles into the earth near fracking sites and allow them to follow subsurface water flow paths to a distance away from the injection site. If the recovered tracers are fluorescent, they are reacting to the fracking chemical they were engineered to detect, demonstrating the path those chemicals traveled.

In continuation of Li's post-doctorate work, these tracers could also be used to improve the recovery of oil from reserves deep within the earth, which would allow scientists to increase the amount of oil that can be pumped, saving time and money on drilling new wells.

"Only about 50 percent of the Earth's oil reservoirs are being tapped," Li said. "With the potential to quickly drain the current oil reserves, the need to improve oil recovery and find the other hidden 50 percent becomes extremely important."

However, these reservoirs are often very deep in the ground and can be home to extreme conditions that make it difficult for nanoparticles to survive. Many nanoparticles that have been developed cannot withstand the high salinity of the oil reserve and deteriorate in the process of finding the oil. However, Li and Sanford believe they have engineered a nanoparticle that can both survive in the harsh environment and keep its smart abilities for a long period of time.

"The uses of these nanoparticles are potentially quite extensive," explained Sanford. "By creating smart particles we can see how contaminants are distributed in the subsurface, the recovery of economic minerals in water can be done, and the uses in the oil industry are many-fold."
Still in the early stages of the research, Li and Sanford are patenting their new nanoparticle and continue to test it in preparation for studies in the field.

The Department of Design and Merchandising is in CSU's College of Health and Human Sciences. The Department of Geosciences is part of the Warner College of Natural Resources.

Source: Colorado State University

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Scientist offers better ways to engineer Earth's climate to prevent dangerous global warming

There may be better ways to engineer the planet's climate to prevent dangerous global warming than mimicking volcanoes, a University of Calgary climate scientist says in two new studies.

Releasing engineered nano-sized disks, or sulfuric acid in a condensable vapor above the Earth, are two novel approaches. These approaches offer advantages over simply putting sulfur dioxide gas into the atmosphere," says David Keith, a director in the Institute for Sustainable Energy, Environment and Economy and a Schulich School of Engineering professor.

Keith, a global leader in investigating this topic, says that geoengineering, or engineering the climate on a global scale, is an imperfect science.

"It cannot offset the risks that come from increased carbon dioxide in the atmosphere. If we don't halt man-made CO₂ emissions, no amount of climate engineering can eliminate the problems -- massive emissions reductions are still necessary."

Nevertheless, Keith believes that research on geoengineering technologies, their effectiveness and environmental impacts needs to be expanded.

"I think the stakes are simply too high at this point to think that ignorance is a good policy."

Keith suggests two novel geoengineering approaches -- 'levitating' engineered nano-particles, and the airborne release of sulfuric acid -- in two newly published studies. One study was authored by Keith alone, and the other with scientists in Canada, the U.S. and Switzerland.

Scientists investigating geoengineering have so far looked mainly at injecting sulfur dioxide into the upper atmosphere. This approach imitates the way volcanoes create sulfuric acid aerosols, or sulfates, that will reflect solar radiation back into space -- thereby cooling the planet's surface.

Keith says that sulfates are blunt instruments for climate engineering. It's very difficult to achieve the optimum distribution and size of the aerosols in the atmosphere to reflect the most solar radiation and get the maximum cooling benefit.

One advantage of using sulfates is that scientists have some understanding of their effects in the atmosphere because of emissions from volcanoes such as Mt. Pinatubo, he adds.

"A downside of both these new ideas is they would do something that nature has never seen before. It's easier to think of new ideas than to understand their effectiveness and environmental risks," says Keith.

In his study-published in the Proceedings of the National Academy of Sciences, Keith describes a new class of engineered nano-particles that might be used to offset global warming more efficiently, and with fewer negative side effects, than using sulfates.

According to Keith, the distribution of engineered nano-particles above the Earth could be more controlled and less likely to harm the planet's protective ozone layer.

Sulfates also have unwanted side-effects, ranging from reducing the electricity output from certain solar power systems, to speeding up the chemical process that breaks down the ozone layer.

Engineered nano-particles could be designed as thin disks and built with electric or magnetic materials that would enable them to be levitated or oriented in the atmosphere to reflect the most solar radiation.

It may also be possible to control the position of particles above the Earth. In theory, the particles might be engineered to drift toward Earth's poles, to reduce solar radiation in polar regions and counter the melting of ice that speeds up polar warming-known as the ice-albedo feedback.

"Such an ability might be relevant in the event that warming triggers rapid deglaciation," Keith's study says.

"Engineered nano-particles would first need to be tested in laboratories, with only short-lived particles initially deployed in the atmosphere so any effects could be easily reversible," says Keith.

Research would also be needed to determine whether such nano-particles could be effectively distributed, given the complex interplay of forces in the atmosphere, and how much cooling might be achieved at the planet's surface.

It is also unknown whether the amount of particles needed-about 1 trillion kilograms per year or 10 million tonnes over 10 years-could be manufactured and deployed at a reasonable cost.

However, Keith notes another study, which looked at the cost of putting natural sulfates into the stratosphere.

"You could manipulate the Earth's climate at large scale for a cost that's of the order of $1 billion a year. It sounds like a lot of money, but compared to the costs of managing other environmental problems or climate change, that is peanuts."

"This is not an argument to do it, only an indication that risk, not cost, will be the deciding issue," he adds.

In a separate new study published in the journal Geophysical Research Letters, Keith and international scientists describe another geoengineering approach that may also offer advantages over injecting sulfur dioxide gas.

Releasing sulfuric acid, or another condensable vapor, from an aircraft would give better control of particle size. The study says this would reflect more solar radiation back into space, while using fewer particles overall and reducing unwanted heating in the lower stratosphere.

The study included computer modeling that showed that the sulfuric acid would quickly condense in a plume, forming smaller particles that would last longer in the stratosphere and be more effective in reflecting solar radiation than the large sulfates formed from sulfur dioxide gas.

Keith stresses that whether geoengineering technology is ever used, it shouldn't be seen as a reason not to reduce man-made greenhouse gas emissions now accumulating in the atmosphere.

"Seat belts reduce the risk of being injured in accidents. But having a seat belt doesn't mean you should drive drunk at 100 miles an hour," he says.

Source: University of Calgary

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