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A microplasma is created by focusing intense laser pulses in air. Besides visible light, the microplasma emits electromagnetic pulses at terahertz frequencies that can be used to detect complex molecules, such as explosives and drugs. (Photo Credit: J. Adam Fenster / University of Rochester)
Study shows lower-power lasers can generate terahertz waves
In a recently published paper, Optics PhD student Fabrizio Buccheri and Xi-Cheng Zhang, Professor of Optics and Director of The Institute of Optics, demonstrate that an approach for generating terahertz waves using intense laser pulses in air — pioneered in 1993 — can be done with much lower power lasers. This had been a major challenge until now.
Buccheri explains that they exploited the underlying physics to reduce the necessary laser power for plasma generation. He adds that it could potentially be improved for applications in explosives or drug monitoring.
Until now, approaches to use a plasma as a broadband source of terahertz have commonly used an elongated plasma generated by combining two laser beams of different frequencies, i.e., colors. This technique, usually referred to as the "two-color" approach, requires powerful, expensive lasers. The "one-color" approach uses single laser frequency to generate the plasma. Pioneered by Harald Hamster and colleagues in 1993, it required even higher laser energies and therefore it was not explored further until this recent paper by Buccheri and Zhang.
The trick was to replace elongated plasmas, ranging in length from few millimeters to several centimeters, with a microplasma about the width of a human hair. Buccheri thinks that fine tuning the type of laser used and changing the air to a different gas could enable even lower operation powers.
An advantage of this "one-color" approach to terahertz radiation is that the terahertz waves propagate in a different direction to the laser beam. This makes it easier for potentially coupling the terahertz waves to a wave guide on a microchip, for example.
Click here to learn more.
Do you have an interesting photo or other image that helps illustrate your research? We would like to showcase it. Send a high resolution jpg or other version, along with a description of what it shows, to bmarcotte@ur.rochester.edu.
Lung-MAP project enables personalized treatment for lung cancer
The more we learn about lung cancer, the more daunting it is.
It causes more deaths in the United States than any other form of cancer.
And, as with other forms of cancer, advances in molecular profiling techniques have provided "more and more evidence that each patient's tumor is different — in its genetic makeup, its aggressiveness and the other things that accompany it," says Eric Kim, Assistant Professor of Medicine (Hematology/Oncology) at the Wilmot Cancer Institute. "This concept of tumor heterogeneity is not only a huge topic, but a huge barrier to offering effective treatment."
Standard chemotherapy, for example, is effective for only a small percentage of patients afflicted with one of the deadliest forms of lung cancer — squamous cell carcinoma. "Most do not benefit, and it is just not right to offer the same toxic therapies just because of a small chance of it working," Kim noted. "Now that we have better tools to understand the underlying molecular characteristics of tumors, we can use targeted agents to precisely attack specific genetic aberrations."
More and more patients are now receiving this kind of targeted, less toxic treatment thanks to a massive national clinical trial called Lung-MAP. The University of Rochester, with Kim as its PI, is one of 557 institutions involved in the project, which is sponsored by the National Cancer Institute, the Southwest Oncology Group and other agencies.
Officially titled "Biomarker-Targeted Second-Line Therapy in Treating Patients With Recurrent Stage IIIB-IV Squamous Cell Lung Cancer," the project enrolls lung cancer patients from all across the country. Biopsied tumor tissue from each patient undergoes comprehensive gene sequencing — at no charge to the patient.
If the sequencing reveals a genetic aberration that is targeted by one of several new drugs being tested by the project, the patient will have an opportunity to receive the drug. If not, the patients could receive novel immunotherapy treatments instead. The very scale of the project will help researchers more quickly refine the use of these drugs and, as new therapies become available, get them into large-scale testing.
Granted, there are innumerable cancer-linked mutations for which no drugs are currently available. Nonetheless, Kim sees great promise in the "paradigm shift" towards precise, personalized treatment based on the patient's individual profile.
"It's not perfect, we do not yet have a different drug for every target because we do not have enough knowledge yet," Kim said. Even so, the availability of even a handful of drugs represents a big improvement over the largely ineffective standard regimens of care.
"I'm excited about being able to have different treatment options for our patients." Kim said. "This is what really distinguishes us from other places that offer just standard care."
Chemotherapy patients feel best if they maintain or slightly increase exercise
Sometimes patients undergoing chemotherapy are encouraged to take it easy throughout their treatments. However, Karen Mustian, Associate Professor of Surgery, says that cancer patients might feel their best if they simply maintain or only slightly increase their physical activity throughout chemotherapy instead of letting it decline.
At a recent American Society of Clinical Oncology (ASCO) meeting, Mustian presented findings that a walking program and gentle resistance-band training at home reduced chronic inflammation that's common among cancer patients receiving chemotherapy. The study's personalized exercise prescription also significantly reduced cognitive impairment — known as chemo-brain — among the 619 study participants.
Mustian's team developed a specialized program called EXCAP (Exercise for Cancer Patients) several years ago and has been evaluating it in clinical trials. Read more here.
Introducing a new faculty member
Niaz Abdolrahim is joining the Department of Mechanical Engineering as an assistant professor. Abdolrahim comes to the University from MIT, where she has worked as a postdoctoral associate on mathematical modeling of interface structure and interface-defect interactions in metals. Her research will focus specifically on using computational techniques to predict the performance of Nanoscale Metallic Materials (NMMs) based on their governing deformation mechanisms. She earned a PhD in mechanical engineering from Washington State University in 2013. Read more here.
Congratulations to . . .
Laurel Carney, Professor of Biomedical Engineering, who has been awarded the William and Christine Hartmann Prize in Auditory Neuroscience by the Acoustical Society of America (ASA). The award recognizes and honors research that links auditory physiology with auditory perception or behavior in humans or other animals. The Carney lab combines neurophysiological, behavioral, and computational modeling techniques to understand neural mechanisms underlying the perception of complex sounds. Most of the lab's work is focused on hearing in listeners with normal hearing ability, but Carney is also interested in applying the results to the design of physiologically based signal-processing strategies to aid listeners with hearing loss.
Phd dissertation defenses
Marina Feigenson, Biochemistry, "Investigating the Role of PGE2 Receptor Subtype 1 in Mesenchymal Stem Cell Differentiation." 8:30 a.m., Monday, June 15, 2015, Neuman Room (1-6823). Advisor: Regis O'Keefe.
Yongchun Zhang, Biochemistry, "beta-CATENIN Signaling Integrates with BMP and CCN1 Signaling to Regulate Chondrocyte Differentiation and Cartilage Development." 1:30 p.m.,
Monday, June 15, 2015, Neuman Room (1-6823). Advisor: Regis O'Keefe.
Click here for a listing of PhD dissertation defenses reported to Research Connections since April 2014.
Mark your calendar
June 15: 1st Annual Rochester Global Health Symposium, 8 a.m. to 5 p.m., Saunders Research Building Atrium. Convenes researchers, students, and practitioners from all sectors of global health to exchange ideas about how to conduct, share, and translate innovative health promotion in low-resource settings. Click here for agenda and registration.
June 17: "Patent Infringement: COX Fighting," presented by Kerry O'Banion, interim chair of the Department of Neurobiology and Anatomy, and University President Emeritus Thomas Jackson. Part of the CTSI workshop series, "Good Advice: Case Studies in Clinical Research, Regulation, and the Law." Noon to 1 p.m. Helen Wood Hall Auditorium.
June 19: "Where Did the New DSM-5 Criteria Come from and Where Will They Take Us?", noon, Whipple Auditorium (Room 26424), Medical Center. Cathy Lord, director of the Center for Autism and the Developing Brain at Weill Cornell Medical School, New York Presbyterian Hospital. The invited guest for the Department of Pediatrics and Golisano Children's Hospital's Gilbert Forbes Lecture, Lord is a noted autism scholar and was a member of the group that revised the DSM criteria.
Aug. 3: Deadline for AS&E PumpPrimerII awards, which are designed to help innovative, high-risk projects develop proof of concept and/or pilot data in order to secure extramural funding. Arts and Sciences faculty can learn more from Debra Haring; Engineering faculty should contact Cynthia Gary.
Please send suggestions and comments to Bob Marcotte. You can see back issues of Research Connections, an index of people and departments linked to those issues, and a chronological listing of PhD dissertation defenses since April 2014, by discipline.
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