Seminars will be held at 4:30 pm each Thursday. The specific meeting room for each seminar is listed along with the speaker information on the web site and on the paper announcement. Be on time! Changes in topic, location or date will be announced at the previous seminar and posted in hard copy outside the Chem & Biochem Department office, S&T I Room 343, and on the seminar web site.

All graduate students are expected to attend all seminars, whether registered or not.

CHEM 790/490 is an attendance/participation based course. It is your responsibility to sign the attendance sheet. You must have at least: 90% attendance to get A, 80% for B, 70% for C, and <70%  for F. In addition, you must submit a summary page of the seminar you have attended. This should be written in your own words demonstrating your interest and understanding. You could use available references on the topic. The hard copy summary is due during the next seminar.

Students who need to present a seminar as a requirement for the MS or PhD should schedule a date one semester in advance since the schedule fills quickly.

All Seminars will take place in EnterPrise Hall, Room 173 , unless otherwise mentioned.

Seminar Updates: March 22, 2012

SPRING 2012 CHEMISTRY AND BIOCHEMISTRY SEMINAR SCHEDULE

Date	Topic and speaker
Jan 26	Adventures in Photovoltaic Technology: Frontlines of the Solar Energy Race Dr. Diogenes Placencia SunShot Fellow, Solar Energy Technologies Program- Energy Efficiency and Renewable Energy, U.S. Department of Energy
Feb 2 Innovation Hall Room 419 4:30 - 6:00 PM	Cell Surface Molecular Mimicry for Bio-Analytical and Pharmaceutical Applications Dr. Xue-Long Sun Associate Professor of Pharmaceutical Chemistry, Department of Chemistry, Cleveland State University, OH
Feb 9 Innovation Hall Room 419 4:30 - 6:00 PM	Drug Discovery for Diseases Associated with Cigarette Smoking Dr. Mikell Paige Georgetown University Medical Center, Washington, DC
Feb 16	Anisotrpoic Particles for Medical Applications Dr. Carolina Morales Assistant Professor, Department of Bioengineering, George Mason University
Feb 23	Bifunctional Transfer Hydrogenation Reactions in Aqueous and Biphasic Media Bahram Moasser PhD Department of Chemistry, Georgetown University
March 1	Optical Remote Sensing of Greenhouse Gases Dr. Kevin Douglass Biophysics Group, Optical Technology Division, National Institute of Standards and Technology, MD
March 8	Mechanical Sensors for Fundamental Biological Research Professor Jun Xi                    Department of Chemistry, Drexel University, PA
March 22	Hybrid materials from the f elements: Synthesis, structure and spectroscopy Dr. Christopher L. Cahill Professor of Chemistry and International Affairs George Washington University, Washington DC
March 29	Smokeless biomass pyrolysis (TBA) Dr. James W. Lee Department of Chemistry and Biochemistry Old Dominion University, VA
April 5	Kinetics of Unimolecular and Recombination Reactions of Radicals in the Gas Phase Dr. Vadim Knyazev Associate Professor, Research Center for Chemical Kinetics, Department of Chemistry     Catholic Univeristy, Washington DC.
April 12	Detection of trace arsenic with electrochemical flow cells Doug Mays (PhD candidate) Department of Chemistry and Biochemistry, George Mason University, VA
April 19	Small Compounds Regulate Scaffold Protein RACK1 Mediated Cellular Stress Signaling Pathways Dr. Hemayet Ullah Associate Professor, Biology Department, Howard University, Washington, DC
April 26	Development and Surface Analysis of Novel Environmentally Benign Marine Coatings Hameed A. Khan (MS candidate) Department of Chemistry and Biochemistry, GMU
May 3	Investigation of platinum and palladium photographs Dr. Matthew L. Clarke Photographic Materials Scientist, National Gallery of Art, Washington, DC

 *Topics are tentative and to be announced (TBA)

SPRING 2012 CHEMISTRY AND BIOCHEMISTRY SEMINARS

Speaker’s profile

Adventures in Photovoltaic (PV) Technology: Frontlines of the Solar Energy Race
Diogenes Placencia, Ph.D.
SunShot Fellow
Solar Energy Technologies Program
Energy Efficiency and Renewable Energy
U.S. Department of Energy
Diogenes.Placencia@ee.doe.gov

Harnessing energy from the sun through solid-state photovoltaic (PV) devices is one of the approaches heavily researched since the development of the first  PV module at Bell Labs in 1954. Since then, emerging and commercial devices with large variations in mechanistic operation, design, and application have resulted in respectable efficiencies, leading government entities and private interest to reconsider solar as a possible energy source for the nation. This talk will focus on some of the basic science challenges faced by emerging PV technologies in their quest to gain higher efficiencies. In addition, the challenges faced by manufacturers within the U.S. will be highlighted, with some of the ways in which the U.S. Department of Energy is trying to mitigate their effect.

Biography

Diogenes Placencia is a SunShot Fellow at the U.S. Department of Energy in Washington, DC. He is based within the Solar Energy Technologies Program (SETP), where he supports Technology Program Managers on current and emerging federal funding opportunities. He is also a Visiting Scientist at the Naval Research Laboratories (NRL) in Washington, DC where he works within theSolid State Devices Branch to advance Pb Chalcogenide-based PV technology. Diogenes graduated from the University of Arizona’s Chemistry Department, studying under Neal R. Armstrong investigating the interface science of small-molecule organic photovoltaics.

Cell Surface Molecular Mimicry for Bio-Analytical and Pharmaceutical Applications
Xue-Long Sun, Ph.D.
Associate Professor of Pharmaceutical Chemistry, Department of Chemistry, Cleveland State University
2121 Euclid Avenue, SI 313
Cleveland, OH, 44115
Tel: 216-687-3919/Fax: 216-687-9298
Email: x.sun55@csuohio.edu
Website: http://academic.csuohio.edu/sunlab

Cell surfaces are highly complex architectures consisting of a variety of molecules such as proteins, carbohydrates and lipids, and perform critical cellular functions. Among them, cell surface carbohydrates existing as glycoconjugates such as glycoprotein, glycolipids, and proteoglycans are playing significant roles in many biological processes, such as cell-cell signaling, immune recognition events, pathogen host interaction, etc. Membrane proteins perform essential functions, including signal transduction, energy conversion, and chemical transport into and out of cells. On the other hand, cell membranes consist of a lipid bilayer, which fulfills many tasks and, in particular, serves as a barrier between different compartments of the cell. Numerous diseases are associated with reduction, loss, or malfunction of the cell surface molecules. Therefore, construction of cell surface mimetic structures opens potential tools to investigate cell surface-related processes and to develop membrane mimetic drugs as well. This talk will introduce our main research interests on cell surface mimicry for pathogen and biomarker identification and for novel antithrombotic development applications. First, an oriented and density controlled glyco-marcroligand microarray formation based on end-point immobilization of glycopolymer will be discussed. Second, a membrane-mimetic assembling of endothelial thrombomodulin will be introduced. In addition, fabrication of immobilized membrane mimetic systems will be introduced for investigation the effects of lipids and its effect on membrane protein and cell surface carbohydrate functions.

Drug Discovery for Diseases Associated with Cigarette Smoking.
Mikell Paige, Ph.D.
Lombardi Comprehensive Cancer Center
3970 Reservior RD, NW
Research Building, EP15A
Washington, DC 20057
Phone # (202) 687-5341
FAX   # (202) 687-7659
email:  map65@georgetown.edu

Anisotropic particles for Medical Applications
Carolina Morales, Ph.D.
Assistant Professor, Department of Bioengineering, George Mason University

There is a great interest among academic and industry investigators to develop differentially surface modified nanoparticles and microparticles to further advance their utility in many fields, most notably in biomedical applications. One example of a differentially modified particle is the Janus particle, named for having two faces on each half of the particle core. This presentation shows nano and micron sized anisotropic particles that have a polymeric core and surface domains. The polymeric core of these particles can serve to encapsulate desired payloads while the surface domains can be further functionalized with a wide variety of organic and inorganic molecules. The creation of this new type of particle, whose functionalized surface could be utilized for different functions while its core could also serve as a source for introducing an additional function, represents the next generation of building blocks for numerous applications in the biomedical, sensing, and electronics fields

.

Green Chemistry (TBA)
Bahram Moasser, Ph.D.
Assistant Professor, Department of Chemistry
Georgetown University 
Phone: 202-687-5937
Fax: 202-687-6209
bm276@georgetown.edu

Optical Remote Sensing of Greenhouse Gases
Kevin Douglass, Ph.D.
Biophysics Group
Optical Technology Division 844
National Institute of Standards and Technology
100 Bureau Drive, Stop 8443
Gaithersburg, MD 20899
Phone 301-975-6489
Fax 301-975-6991
Email kevin.douglass@nist.gov

Our goal is to develop measurement technology needed to accurately quantify greenhouse-gas emissions from natural and anthropogenic sources and sinks to meet the requirements for local, national, and international mitigation efforts.  To meet these challenges we are developing new methods to perform optical remote sensing using differential absorption LIght Detection And Ranging (LIDAR).  A DIfferential Absorption LIDAR (DIAL) system measures chemical specific concentration with range resolution.  A LIDAR measurement is performed by sending a laser pulse through the atmosphere and the pulse of light is scattered from aerosols and molecules.    The backscattered light is collected with a telescope and imaged onto a detector while the signal is recorded as a function of time.   The pulse time of flight yields a distance dependent measurement.  A DIAL system has the ability to map out a 3-dimensional plume of gas directly without using complex mathematical models.   Our DIAL system operates in the eye safe 1600 nm wavelength region where three critical greenhouse gases, carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) have vibrational absorption bands.  The final system will be capable of measuring both concentration and wind speed in order to determine emission rates.  Various components of the DIAL instrument are currently under construction and research is focused on developing; 1. a high energy near infrared laser system, 2. an optical transmitter and receiver, 3. novel detection strategies, and 4. a 100 meter long indoor test facility.   The test facility will enable careful characterization of the DIAL system and may serve as a reference for other remote sensing systems.  An overview of the DIAL system and recent results will be presented.

Mechanical Sensors for Fundamental Biological Research
Jun Xi, Ph.D.                         
Professor, Department of Chemistry
Drexel University, PA

To advance the fundamental understanding of the complex world of biology depends on the development of innovative approaches. In this talk, I will touch on our recent effort to apply mechanical sensors to probe the interfacial enzymology of cellulase and to explore epidermal growth factor receptor (EGFR)-mediated cell signaling. Cellulase catalyzes the hydrolytic degradation of cellulose at a liquid/solid interface, and has been widely used to convert cellulosic biomass to fermentable sugars for biofuel production. Prior to the hydrolytic cleavage, cellulase utilizes an activity known as enzymatic decrystallization to break up the solid aggregate of cellulose molecules to release them from their solid aggregate into the active site of the enzyme. We utilized a nanomechanical sensor in a microcantilever to detect such unusual enzymatic activity based on the dynamic bending of the microcantilever. EGFR has often shown two distinct binding affinities for epidermal growth factor. It is the high-affinity EGFR that is predominantly responsible for mediating the cell signaling that plays an indispensable role in cell growth, proliferation, motility, and differentiation. The extent of cell signaling mediated by high-affinity EGFR can be very informative for assessing the role of EGFR in cancer development and cancer prognosis. We applied the quartz crystal microbalance with dissipation monitoring (QCM-D) to detect cellular responses to high- and low-affinity EGFR signaling individually as well as simultaneously based on changes in mass and viscoelasticity of cells. These responses are associated with EGF-induced biological processes including the cytoskeleton remodeling and calcium influx.

Hybrid materials from the f elements: Synthesis, structure and spectroscopy
Christopher L. Cahill, Ph.D.
Professor of Chemistry and International Affairs
725 21st Street, NW Corcoran 107
Washington, DC 20052
Samson 315
202) 994-6959
cahill@gwu.edu

Hybrid materials in general typically consist of an inorganic oxide component coupled to an organic portion via covalent, ionic or van der Waals interactions. The recent literature is rich with examples of such coordination polymer or metal-organic framework (aka ‘MOF’) compounds.  The majority of these materials however, are based on transition metal chemistry, leaving compounds based on f-metals less explored. This presentation will highlight results from our efforts to develop the synthesis, crystal chemistry and ultimately the properties of Ln(III), UO2n+ and Th(IV) based hybrid materials.  Structural features absent from d-metal systems (such as spherical coordination environments), provide unique challenges and opportunities for the formation of extended topologies.  Further, metal mediated organic reactivity under hydrothermal conditions gives rise to novel structure types based on ligands generated in situ. Comments that place these results in the context of environmental issues and hydrothermal syntheses in general will be presented as well.

Smokeless biomass (TBA)
James W. Lee, PhD
Assistant Director,  Virginia Coastal Energy Research Consortium
Faculty (Associate Professor), Old Dominion University
Department of Chemistry and Biochemistry
Physical Sciences Building, Rm. 3100B
4402 Elkhorn Avenue
Norfolk, Virginia 23529
Tel: (757) 683-4260
Email: JWLee@ODU.edu

Sustainability: Smokeless Biomass Pyrolysis for Biochar Soil Amendment and Global Carbon Sequestration

James W. Lee, PhD Assistant Director,  Virginia Coastal Energy Research Consortium Faculty (Associate Professor), Old Dominion University Department of Chemistry and Biochemistry Physical Sciences Building, Rm. 3100B 4402 Elkhorn Avenue Norfolk, Virginia 23529 Tel: (757) 683-4260 Email: JWLee@ODU.edu

 

Kinetics of Unimolecular and Recombination Reactions of Radicals in the Gas Phase
Vadim Knyazev, Ph.D.
Associate Professor
Research Center for Chemical Kinetics
Department of Chemistry    
Catholic Univeristy                                         
Tel: (202) 319-6742
Email:  knyazev@cua.edu

Scaffold proteins are known as important cellular regulators that can interact with multiple proteins to modulate diverse signal transduction pathways. RACK1 (Receptor for Activated C Kinase 1) is a WD-40 type scaffold protein, conserved in eukaryotes, from Chlamydymonas to plants and humans, plays regulatory roles in diverse signal transduction and stress response pathways.  RACK1 in humans has been implicated in myriads of neuropathological diseases including Alzheimer and alcohol addictions. Model plant Arabidopsis thaliana genome maintains three different RACK1 genes termed RACK1A, RACK1B, and RACK1C with a very high (85-93%) sequence identity among themselves. Loss of function mutant in Arabidopsis indicates that RACK1 proteins regulate diverse environmental stress signaling pathways including drought stress resistance pathway. Recently deduced crystal structure of Arabidopsis RACK1A- very first among all the RACK1 proteins, indicates that it can potentially be regulated by post-translational modifications, like tyrosine phosphorylations and sumoylation at key residues. Here we show evidence that  RACK1A proteins, depending on diverse environmental stresses, are tyrosine phosphorylated and sumoylated.  Utilizing site-directed mutagenesis of key tyrosine and lysine residues, it is found that tyrosine phosphorylation and sumoylation can potentially dictate the homo-dimerization of RACK1A proteins. Targeting the diverse post-translational modification sites of RACK1A, small inhibitor compounds are isolated. High efficacy compounds are identified for their ability to counter specific environmental stress pathways known to be regulated by RACK1A protein. Considering the very high structural conservation of RACK1A across the kingdoms, similar compounds are expected to regulate human RACK1 regulated pathological conditions as well.

The appearance and chemical and physical stability and of a photograph depend upon the materials and processes used in its creation as well as its history of storage, display, and conservation treatment. Proper preservation requires a thorough understanding of each of these variables as well as the underlying chemical reactions and interactions responsible for change. Scientific analysis can aid in identifying a photograph's components and determining possible mechanisms of image formation and degradation. This presentation will detail the production of historic platinum and palladium photographs (popular circa 1890-1920s and 1917-1930s, respectively), and our investigations into the factors that affect their appearance and longevity. Research into the historic commercial chemical modification of the photographic paper surface, resulting in a unique texture, will also be discussed.

Biography

Matthew Clarke received his B.S. in chemistry from the University of Wisconsin – Green Bay. He earned his M.S. and Ph.D. in chemistry from the University of Michigan where his research focused on polymer interfaces. He subsequently investigated optical imaging methods and analyses at the National Institute of Standards and Technology. Dr. Clarke is now a photographic materials scientist in the Scientific Research Department at the National Gallery of Art where he works in support of the conservation program.

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