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Protein tyrosine phosphatases (PTPs) play a critical role in regulating cellular functions by selectively dephosphorylating their substrates. Here we present 22 human PTP crystal structures that, together with prior structural knowledge, enable a comprehensive analysis of the classical PTP family. Despite their largely conserved fold, surface properties of(More)
There is a growing recognition of the importance of protein kinases in the control of alternative splicing. To define the underlying regulatory mechanisms, highly selective inhibitors are needed. Here, we report the discovery and characterization of the dichloroindolyl enaminonitrile KH-CB19, a potent and highly specific inhibitor of the CDC2-like kinase(More)
We describe techniques that enable fabrication of a new class of photonic devices based on free UH-Q microresonators. Preliminary results show that free silica microtoroids with Qs above 30 million can be fabricated and transferred to different platforms for integration with a variety of photonic devices. Very high-order microring resonator filters for WDM(More)
  • Ayça Yalçın, Ketul C Popat, John C Aldridge, Tejal A Desai, John Hryniewicz, Nabil Chbouki +8 others
  • 2006
—A biosensor application of vertically coupled glass mi-croring resonators with Q ∼ 12 000 is introduced. Using balanced photodetection, very high signal to noise ratios, and thus high sensitivity to refractive index changes (limit of detection of 1.8 × 10 −5 refractive index units), are achieved. Ellipsometry and X-ray pho-toelectron spectroscopy results(More)
All fiber lasers to date emit radiation only along the fiber axis. Here a fiber that exhibits laser emission that is radially directed from its circumferential surface is demonstrated. A unique and controlled azimuthally anisotropic optical wave front results from the interplay between a cylindrical photonic bandgap fiber resonator, anisotropic organic dye(More)
RecQ helicases have attracted considerable interest in recent years due to their role in the suppression of genome instability and human diseases. These atypical helicases exert their function by resolving a number of highly specific DNA structures. The crystal structure of a truncated catalytic core of the human RECQ1 helicase (RECQ1(49-616)) shows a(More)
BACKGROUND Hundreds of millions of people are infected with cryptosporidiosis annually, with immunocompromised individuals suffering debilitating symptoms and children in socioeconomically challenged regions at risk of repeated infections. There is currently no effective drug available. In order to facilitate the pursuit of anti-cryptosporidiosis targets(More)
Optical resonators designed for biological sensing and imaging are demonstrated to yield sub-nanometer position accuracy in DNA conformation, high-sensitivity in ring-resonators for biosensing, and massively parallel, non-labeled detection in a Resonant Cavity Imaging Biosensor. Resonance is an enabling property of a myriad of optical devices such as(More)
We report the initial evaluation of a mid-infrared QCL-coupled silicon-on-sapphire ring resonator gas sensor. The device probes the N 2 O 2241.79 cm −1 optical transition (R23 line) in the ν 3 vibrational band. N 2 O concentration is deduced using a non-linear least squares fit, based on coupled-mode theory, of the change in ring resonator Q due to gas(More)
An etched beam splitter (EBS) photonic coupler based on frustrated total internal reflection (FTIR) is designed, fabricated and characterized in the InP/InGaAsP material system. The EBS offers an ultra compact footprint (8x11 μm) and a complete range of bar/cross coupling ratio designs. A novel pre-etching process is developed to achieve sufficient depth of(More)
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