Events Calendar View

• Departmental Colloquium Sep 2, 2010

  First Principles Simulations of Piezoelectric Oxides

  

  Guest: Dr. Valentino Cooper, Oak Ridge National Laboratory, Materials Science and Technology Division
  Thursday, September 2, 2010 4:00 pm - 5:00 pm
  Location: Physics 202

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  Piezoelectrics are dielectric materials which convert electrical energy to mechanical energy (and vice-versa).  It is this coupling which makes them crucial to the success of a variety of modern devices including SONAR, ultrasound machines, non-volatile memory devices, and chemical and biological sensors.  Given their importance, there has been much research devoted to enhancing the electromechanical responses of these materials.  Recent advances in theory, most notably the ability to accurately compute the macroscopic polarization using first principles density functional theory, have opened the door to the computational discovery of new piezeoelectrics.  In this presentation, I will demonstrate how concepts and insights gained from first principles calculations can be used to tailor the properties of complex oxides.  In particular, I will discuss our use of epitaxial strain through superlattice geometries [1] and chemical composition and ordering [2] to predict structures with enhanced piezoelectric properties. 
  1.  V. R. Cooper and K. M. Rabe, Phys. Rev. B 79 (18), 180101 (2009).
  2.  S. Takagi, A. Subedi, D. J. Singh and V. R. Cooper, Phys. Rev. B 81 (13), 134106 (2010).

• NanoSEC Seminar Sep 3, 2010

  Nano-Carbon: Fundamental Exploration and Technological Development

  

  Guest: Prof. Ya-Ping Sun, Department of Chemistry and Laboratory for Emerging Materials and Technology, Clemson University
  Friday, September 3, 2010 4:00 pm - 5:00 pm
  Location: Riverbend Research South Laboratory Auditorium

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  Nanoscale carbon materials, including fullerenes, carbon nanotubes, graphene nanosheets, and small carbon nanoparticles, have interesting and/or unique properties. We have been studying these nanomaterials, from fullerene conjugates with anticancer drugs and bulkseparated metallic/semiconducting single-walled carbon nanotubes for electrical/electronic materials and applications to more recently graphene nanosheets for thermal and mechanical nanocomposites and carbon-based photoluminescent nanoparticles (“carbon dots”) as effective imaging agents. In this talk, some interesting and representative results from our research will be highlighted.

• Departmental Colloquium Sep 9, 2010

  Quantum computing with Bose--Einstein condensate Bragg interferometry

  

  Guest: Dr. Mark Edwards, Georgia Southern University, Department of Physics
  Thursday, September 9, 2010 4:00 pm - 5:00 pm
  Location: Physics 202

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  Quantum computers use the interferences of different computational paths to enhance correct outcomes. Quantum computation can be viewed as multi-particle computational interference [1].  I will describe how quantum circuits can be mapped to interferometry experiments performed on Bose-Einstein condensates (BECs) using Bragg pulses. I further describe an extension to an approach, originally developed to prototype Bragg interferometry of BECs [2], to describe new interferometers inspired by quantum information concepts. This approach follows ideas recently introduced in neutron inter- ferometry [3].  Using techniques that have been well calibrated by experiments in con- ventional BEC interferometry [2], experiments associated with some simple quantum circuits using the prototyping method mentioned above are modeled. We prototype ex- tensions to standard Mach-Zehnder configurations, analogous to the four-blade designs of neutron interferometry.
  [1] R. Cleve, et al., Proc. R. Soc. Lond. A 454 339 (1998)
  [2] J. E. Simsarian, et al., Phys. Rev. Lett. 85, 2040 (2000)
  [3] D. A. Pushin, M. Arif, and D. G. Cory, Phys. Rev. A 79, 053635, (2009)

• NanoSEC Seminar Sep 10, 2010

  Targeted Delivery of Therapeutics

  

  Guest: Prof. Shanta Dhar, Department of Chemistry, University of Georgia
  Friday, September 10, 2010 4:00 pm - 5:00 pm
  Location: Riverbend Research South Laboratory Auditorium

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  Three platinum(II) complexes, cisplatin, carboplatin, and oxaliplatin, have been approved by the US FDA for the treatment of cancer. Structural and mechanistic studies have elucidated four early steps that describe their action, cell entry, activation, DNA binding, and transcription inhibition while eluding repair. In spite of the clinical success of cisplatin, there are many occasions where treatment must be discontinued due to drug resistance, acquired or intrinsic, arises from reduced cellular uptake, enhanced DNA repair, drug deactivation, or a combination of these mechanisms. One strategy to overcome resistance is to design specific functionalities onto platinum to enhance uptake and delivery via drug targeting. Oxidation of cisplatin affords Pt(IV) species, known as prodrugs, that can be derivatized with axial ligands for attaching the resulting complexes to carriers for targeted delivery to cancer cells. Upon entry into the cell, the platinum(IV) is reduced, liberating cisplatin and the axial ligands, which can potentiate the cell-killing properties of the construct. In this manner we have functionalized single-walled carbon nanotubes as “longboat” carriers of Pt(IV) constructs into cells, specifically targeted the folate receptor on cancer cells and delivered platinum complexes with extraordinary potency against folate receptor overexpressing cancer cells.1 Dose limiting toxicities or resistance also limit application of cisplatin in many types of cancer including prostate. We devised a unique strategy to deliver cisplatin to prostate cancer cells by constructing Pt(IV)-encapsulated prostate-specific membrane antigen (PSMA) targeted nanoparticles (NPs) of poly(D,L-lactic-co-glycolic acid) (PLGA)-poly(ethylene glycol) (PEG)-functionalized controlled release polymers. By using PLGA-b-PEG nanoparticles with PSMA targeting aptamers (Apt) on the surface as a vehicle for a platinum(IV) prodrug, a lethal dose of cisplatin was delivered specifically to prostate cancer cells.2 By appending axial ligands that destroy the mitochondrial function of the cancer cell while platinum simultaneously impeding DNA-mediated processes in the nucleus, we have synthesized a novel compound mitaplatin, and this new construct is currently being evaluated for anticancer activity vs. normal cells.3 Our technologies provide a potentially important platform for spatiotemporal, controlled release of two or more drugs for future applications in human cancer chemotherapy.4
  1. Dhar, S.; Liu, Z.; Thomale, J.; Dai, H. and Lippard, S. J. “Targeted Single Walled Carbon Nanotube Mediated Pt(IV) Prodrug Delivery using Folate as Homing Device”, J. Am. Chem. Soc. 2008, 130, 11467‐11476.
  2. Dhar, S.; Gu, F. X.; Langer, R.; Farokhzad, O. C. and Lippard, S. J. “Targeted Delivery of Cisplatin to Prostate Cancer Cells by Aptamer Functionalized Pt(IV) Prodrug‐PLGA–PEG Nanoparticles”,Proc. Natl. Acad. Sci. USA, 2008, 105, 17356‐17361.
  3. Dhar, S. and Lippard, S. J. Proc. Natl. Acad. Sci. USA, 2009, 106, 22199‐22204.
  4. Kolishetti, N.; Dhar, S.; Pedro, V.; Lin, L.; Karnik, R.; Lippard, S. J. Langer, R.; Farokhzad, O. C. and “Engineering of Self‐assembled Nanoparticle Platform for Precisely‐controlled Combination Drug Therapy”, Proc. Natl. Acad. Sci. USA, 2010, in press.

• CSP Lunch Seminar Sep 14, 2010

  Using RCC machines: Shell, Compilers and Running Jobs

  

  Guest: Shan-ho Tsai
  Tuesday, September 14, 2010 12:30 pm - 1:30 pm
  Location: CSP Conference Room (322)

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• Departmental Colloquium Sep 16, 2010

  Implementing and Sustaining Curricular Reform in a Large Introductory Physics Course at Georgia Tech

  

  Guest: Dr. Mike Schatz, Georgia Institute of Technology, School of Physics
  Thursday, September 16, 2010 4:00 pm - 5:00 pm
  Location: Physics 202

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  A novel physics curriculum, Matter and Interactions (M&I), was introduced into Georgia Tech engineering physics courses in Summer 2006; today the curriculum is taught to approximately one thousand students each semester.  We will highlight some key issues associated with implementing the M&I curriculum. We will also describe efforts to measure the new curriculum's impact using both standardized assessment tools (concept inventories) and in-depth student interviews (think-aloud protocol studies).  The presentation will highlight barriers to implementing and to sustaining reform curricula in university physics courses.

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