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X-RAY RUNS: Apply for Beamtime

2017  Nov 1 - Dec 21

2018  Feb 7 - Apr 3
2018  Proposal/BTR deadline: 12/1/17

2018  Apr 11 - Jun 4
2018  Proposal/BTR deadline: 2/1/18

CHESS users

 

Talk Abstracts

 

 
"Illuminating Life on the Rocks: Synchrotron studies of Martians, Mines, and Mints"

Neil Banerjee
University of Western Ontario

Abstract: Synchrotron analysis in astrobiology, life-of-mine, and numismatic studies are novel niches that are currently under-utilized in the geosciences. Harnessing synchrotron light for rapid, micron-scale analysis provides a powerful tool that addresses both academic and industry relevant problems. For example, understanding the distribution and speciation of trace elements in ore minerals is relevant throughout the life-of-mine cycle, including exploration, ore processing, and remediation. In an industry that is a cornerstone of the Canadian and US economies, innovation is key to success. The application of synchrotron science to the mineral exploration industry represents a paradigm shift in the way we utilize high-resolution analysis for mineral exploration. The capabilities of synchrotron analysis provide unprecedented contextual trace element distribution and speciation information, which can be tied to mineralogy; something lacking in conventional bulk rock analysis. This provides critical insights into trace element associations within ore minerals, which can be applied to novel exploration vectors and provide valuable information on local redox conditions responsible for mineralization. The development of these techniques for industry purposes is key to improving efficiency throughout mine life, from exploration to ore processing and remediation. However, the classic barrier to adoption of these techniques by the broader geoscience community has been advanced knowledge of synchrotron techniques and data analysis. Collaborative work at CHESS, APS, and the CLS has uniquely positioned our group to overcome this barrier. Through this collaborative approach between academia, industry, and synchrotrons we are now tackling these problems head on to develop techniques for the broader geoscience community and mining industry.

 

 
"In-situ x-ray scattering studies of organic semiconductor thin film deposition"

Randall Headrick
University of Vermont

Abstract: Organic semiconductors have potential applications in electronic devices ranging from displays to solar cells. Methods to produce thin films with control of grain structure, defects, and polymorphism has recently emerged as a key research area, since the lack of suitable methods is a bottleneck for fully exploiting organic semiconductor materials as well as for evaluating their intrinsic properties. In this talk I will describe our recent work at CHESS on in-situ time resolved X-ray scattering studies of solution processing, and also earlier work on in-situ studies by vacuum-based vapor deposition. Both solution-based and vapor deposition methods have strengths and weaknesses for various applications as well as different fundamental challenges. I will also briefly discuss instrumentation and support needs for future synchrotron-based X-ray studies in this area relevant to the planned CHESS upgrades.

 

 
"Fashionable Nanotechnology: Molecular strategies for Creating Smart Natural Fibers via Manipulation of Nanoscale Phenomena"

Juan P Hinestroza
Cornell University

Abstract: In this presentation, we will discuss several strategies –based on self, forced and convective assembly techniques – that our laboratory have used to modify the properties of natural fibers using nanoscale materials. Furthermore, we will explore how our work on the frontiers of fiber science intersects with the work of apparel designers to create “fashionable nanotechnology”

We will discuss three cases. In the first case, we will discuss the assembly of functionalized nanoparticles on the surface of cellulosic fibers aimed at creating conformal and uniform coatings with nanoscale precision. Some of these conformal coatings exhibit enhanced antibacterial properties and can be used to create tunable structural coloration effects. Since the space between particles can be tailored by controlling the functionalization of the cotton’s surface and the chemistry of the nanoparticles, unique olephobic/hydrophobic surfaces as well as highly sensitive substrates for SERS spectroscopy were created.

In the second case we will discuss the development of electrically responsive cellulosic fibers using an in-situ polymerization method capable of creating flexible bridges between nanoparticles. The resulting conductive threads could be used for simultaneously sewing and wiring wearable electronic textiles. Furthermore, the same procedure was used to create semiconductor-based nanolayers on cotton fibers and these layers were assembled into two types of cotton-based transistors – and Organic electrochemical transistor (OECT) and an organic field effect transistor (OFET). In the third case, we will discuss the use of metal-organic frameworks (MOFs) to create textiles capable of sensing and trapping toxic gases, insecticides and other value-added compounds by judiciously controlling the interactions between the MOF and the functional groups on the surface of the natural fibers.

These examples demonstrate how “old” natural fibers such as cotton can be transformed into engineering material with unique functionalities while preserving its comfort, flexibility and water absorbency properties. The strategies developed by our group to create multifunctional cellulosic materials are scalable and could be replicated in many other cellulose-based natural fibers. The intersection between design and science will also be discussed as prototypes were created for each one of the discussed cases by teamwork between fashion design and fiber science students.

 
"The future of x-ray beam imaging: diamond x-ray detectors for high flux synchrotron applications"

Erik Muller
SUNY Stony Brook

 

 
"A structural view of the neuronal cell adhesion proteins "

Moutse Ranaivoson
University of Medicine & Dentistry of NJ

Abstract: Despite the involvement of neuronal adhesion molecules in neuron-neuron interaction and their key role in neuronal maturation, migration, and connectivity, little is known about the structure and the molecular function of this class of cell surface proteins. Here we describe our structural and mechanistic work on two distinct neuronal adhesion proteins: contactin associated-like protein 2 (CASPR2) and Latrophilin 3 (LPHN3).

CASPR2 is a multidomain transmembrane protein that shares similar domain organization with the neurexin (NRXN) superfamily at the primary structure level. Genetic abnormalities in CASPR2 protein has been implicated in a broad range of phenotypes including autism spectrum disorder and language impairment. We provided the first structural characterization of this protein using SAXS and single particle electron microscopy, showing that CASPR2 is highly glycosylated and has an overall compact architecture. Functionally, we show that CASPR2 associates with micromolar affinity with CNTN1 but, under the same conditions, it does not interact with any of the other members of the contactin family.

Latrophilins (LPHNs) are adhesion-like G-protein coupled receptors implicated in attention-deficit/hyperactivity disorder. LPHN3 was found to establish trans-interactions with fibronectin leucine-rich repeat transmembrane 3 (FLRT3). By isothermal titration calorimetry, we determined that only the olfactomedin (OLF) domain of LPHN3 is necessary for FLRT3 association. By multi-crystal native single-wavelength anomalous diffraction phasing, we determined the crystal structure of the OLF domain in two conformations, depending on the presence a Ca2+ in the central pore of its five-bladed -propeller structure. We also have determined the crystal structure of the OLF/FLRT3 complex describing the OLF/FLRT3 complex inter-molecular interface. Finally, we have helped characterizing a higher-order complex involving LPHN, FLRT and UNC5D, a ligand that plays a role in the regulation of attraction or repulsion between neuronal cells.

 
"For cellular to atomic resolution of how enzymes cut inside membranes"

Sin Urban
Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine

Abstract:  At the turn of the millennium an extraordinary class of enzymes that cut proteins inside the cell membrane were discovered. Rhomboid proteases are the largest family of these ancient membrane-immersed enzymes. Although deceptively simple, the act of hydrolyzing a single peptide bond inside the water-excluding environment of the cell membrane by rhomboid has evolved to trigger cell signaling events during bacterial growth, animal embryogenesis, and mitochondrial quality control throughout the life of a cell. The membrane is a challenging environment for catalysis, and structural biology has been key in efforts to decipher how these unusual enzymes function. We have been combining X-ray crystallography with developing quantitative methods specifically to study rhomboid catalysis directly inside the membrane. I will discuss an integrated but unexpected model for how rhomboid proteases function, and how we have been translating these new insights to combating devastating parasitic diseases that have been plaguing mankind for millennia, including malaria.