Archive for the ‘Tech’ Category

Flasks, beakers and hot plates may soon be a thing of the past in chemistry labs. Instead of handling a few experiments on a bench top, scientists may simply pop a microchip into a computer and instantly run thousands of chemical reactions, with results — literally shrinking the lab down to the size of a thumbnail.

A microfluidic device held in the palm of the hand.

Toward that end, UCLA researchers have developed technology to perform more than a thousand chemical reactions at once on a stamp-size, PC-controlled microchip, which could accelerate the identification of potential drug candidates for treating diseases like cancer.

Their study appears in the Aug. 21 edition of the journal Lab on a Chip and is currently available online.

A team of UCLA chemists, biologists and engineers collaborated on the technology, which is based on microfluidics — the utilization of miniaturized devices to automatically handle and channel tiny amounts of liquids and chemicals invisible to the eye. The chemical reactions were performed using in situ click chemistry, a technique often used to identify potential drug molecules that bind tightly to protein enzymes to either activate or inhibit an effect in a cell, and were analyzed using mass spectrometry.

While traditionally only a few chemical reactions could be produced on a chip, the research team pioneered a way to instigate multiple reactions, thus offering a new method to quickly screen which drug molecules may work most effectively with a targeted protein enzyme. In this study, scientists produced a chip capable of conducting 1,024 reactions simultaneously, which, in a test system, ably identified potent inhibitors to the enzyme bovine carbonic anhydrase.

Design of the second generation integrated microfluidic device.

A thousand cycles of complex processes, including controlled sampling and mixing of a library of reagents and sequential microchannel rinsing, all took place on the microchip device and were completed in just a few hours. At the moment, the UCLA team is restricted to analyzing the reaction results off-line, but in the future, they intend to automate this aspect of the work as well.

“The precious enzyme molecules required for a single in situ click reaction in a traditional lab now can be split into hundreds of duplicates for performing hundreds of reactions in parallel, thus revolutionizing the laboratory process, reducing reagent consumption and accelerating the process for identifying potential drug candidates,” said study author Hsian-Rong Tseng, a researcher at UCLA’s Crump Institute for Molecular Imaging, an associate professor molecular and medical pharmacology at the David Geffen School of Medicine at UCLA, and a member of the California NanoSystems Institute at UCLA.

Kym F. Faull, director of the Pasarow Mass Spectrometry Lab at UCLA, helped the team with several challenges, including reducing the amount of chemicals needed for reactions on the chip, enhancing test sensitivity and speeding up reaction analysis.

“The system allows researchers to not only test compounds quicker but uses only tiny amounts of materials, which greatly reduces lab time and costs,” said Faull, a professor of psychiatry and biobehavioral sciences at the Geffen School of Medicine.

Next steps for the team include exploring the use of this microchip technology for other screening reactions in which chemicals and material samples are in limited supply — for example, with a class of protein enzymes called kinases, which play critical roles in the malignant transformation of cancer.

According to the researchers, the technology may open up many areas for biological and medicinal study.

The study team relied on work in the UCLA labs of Michael E. Phelps, Norton Simon Professor and chair of molecular and medical pharmacology, and Clifton K.F. Shen, assistant professor of molecular and medical pharmacology. Key research contributors included Yanju Wang, Wei-Yu Lin and Kan Liu, who work in Tseng’s lab and intend to continue this line of research in independent careers after completing their training with Tseng.

The study was funded by the U.S. Department of Energy and the National Institutes of Health.

Other authors include: Rachel J. Lin of UCLA’s Crump Institute for Molecular Imaging; Matthias Selke of the department of chemistry and biochemistry at California State University, Los Angeles; Hartmuth C. Kolb of Siemens Medical Solutions; Nangang Zhang of UCLA’s Crump Institute for Molecular Imaging and the department of physics and Center of Nanoscience and Nanotechnology at China’s Wuhan University; and Xing-Zhong Zhao of the department of physics and Center of Nanoscience and Nanotechnology at China’s Wuhan University.
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Electrical engineering researchers at the University of Arkansas and the University of South Carolina were informed this week that they will receive federal economic stimulus funds via the National Science Foundation to continue and strengthen their efforts to modernize the national power grid. The award will establish an NSF center of excellence, known as an Industry/University Cooperative Research Center.

The new center will focus on grid-connected, advanced-power electronic systems and will be operated jointly by researchers at both universities. It reinforces a major research thrust – grid-connected power electronics – of the university’s existing National Center for Reliable Electric Power Transmission.

“These funds will help us develop the knowledge, tools, hardware, software and personnel to flood the 21st century power grid with power electronics,” said Alan Mantooth, professor of electrical engineering and executive director of both the new center and the existing NCREPT. “The nature of this grant will enable us to expand NCREPT’s work with utility companies, defense contractors, equipment manufacturers, component suppliers and others to bring to market the technologies that will be needed to realize a robust and more reliable power grid.”

The award, funded under the American Recovery and Reinvestment Act of 2009, becomes effective Sept. 1 and lasts for five years. It is renewable for up to another five years. Each year of the grant period, the National Science Foundation will provide $113,000 for administrative costs to the University of Arkansas as lead institution and $63,000 to the University of South Carolina. In addition, as part of the industry/university cooperative, large companies – the utility companies and equipment manufacturers Mantooth mentioned – will contribute $40,000 per year to be members of the center. Small companies, as defined by the federal Small Business Administration, will contribute $5,000 annually. So far the center has recruited 12 private companies and is seeking more, Mantooth said.

The researchers work with purely electronic – referred to as “solid-state” – systems, which they are designing to replace or augment the grid’s existing electromechanical switchgear. The latter sometimes do not function as quickly as needed and thus lead to unreliable service. Made of silicon-carbide, a durable and fast semiconducting material, new solid-state systems will help manufacturers produce power electronic hardware that can react as much as 200 times faster than the electromechanical devices currently used in the power grid.

Mantooth said the combination of academic research and industry insight, made possible by this grant, will accelerate commercialization of solid-state systems. The researchers will focus on design, development, evaluation, control and standardization of grid-connected power-electronic equipment. Attention will also be given to intelligent coordination of the emerging, digitally controlled electric power grid.

The overall goal of the center is to pursue projects that enhance grid reliability. The center will also train students and practicing engineers to develop and manage the next generation of power systems. Producing more students in this field is important to both Arkansas and the nation, Mantooth said. The energy and power industry estimates that more than 50 percent of the engineers will retire in the next five to 10 years. Young people are being encouraged to strongly consider a career in electrical engineering to meet this demand.

“To put this in perspective, if all the of country’s electrical engineering programs put all of their students into this field, it wouldn’t be enough,” Mantooth said. “So our graduates are seeing wonderful employment opportunities at the bachelor’s, master’s and Ph.D. levels.”

The grant will help researchers make full use of NCREPT’s unique test facility, a 7,000-square-foot building at the Arkansas Research and Technology Park in south Fayetteville. The facility, which is capable of testing power systems up to 6 megawatts, consists of several transformers, many circuit breakers and regeneration drives that are connected in a highly reconfigurable and programmable manner to enable many types of application scenarios, including distributed generation (wind, solar, etc.) and protection devices.

In addition to Mantooth, other University of Arkansas researchers involved in the project include Simon Ang, Juan Balda and Roy McCann, professors of electrical engineering; T. A. Walton, the managing director of NCREPT; Yongfeng Feng and Brian Rowden, research assistant professors; and approximately 40 graduate and undergraduate students in electrical engineering.

Mantooth is the Twenty-First Century Chair in Mixed-Signal Integrated Circuit Design and Computer-Aided Design in the College of Engineering.