Enhancing cell therapies from the outside in: Cell surface engineering using synthetic nanomaterials

Therapeutic treatments based on the injection of living cells are in clinical use and preclinical development for diseases ranging from cancer to cardiovascular disease to diabetes. To enhance the function of therapeutic cells, a variety of chemical and materials science strategies are being developed that engineer the surface of therapeutic cells with new molecules, artificial receptors, and multifunctional nanomaterials, synthetically endowing donor cells with new properties and functions. These approaches offer a powerful complement to traditional genetic engineering strategies for enhancing the function of living cells.Massachusetts Institute of Technology. Center for Materials Science and Engineering (National Science Foundation (U.S.) DMR-0819762)United States. Dept. of Defense. Prostate Cancer Research Program (W81XWH-10-1-0290)National Institutes of Health (U.S.) (CA140476)National Institutes of Health (U.S.) (EB012352

Non-linear photonic crystals as a source of entangled photons

Non-linear photonic crystals can be used to provide phase-matching for frequency conversion in optically isotropic materials. The phase-matching mechanism proposed here is a combination of form birefringence and phase velocity dispersion in a periodic structure. Since the phase-matching relies on the geometry of the photonic crystal, it becomes possible to use highly non-linear materials. This is illustrated considering a one-dimensional periodic Al$_{0.4}$Ga$_{0.6}$As / air structure for the generation of 1.5 $\mu$m light. We show that phase-matching conditions used in schemes to create entangled photon pairs can be achieved in photonic crystals.Comment: 4 pages, 3 figure

Spin gating electrical current

We use an aluminium single electron transistor with a magnetic gate to directly quantify the chemical potential anisotropy of GaMnAs materials. Uniaxial and cubic contributions to the chemical potential anisotropy are determined from field rotation experiments. In performing magnetic field sweeps we observe additional isotropic magnetic field dependence of the chemical potential which shows a non-monotonic behavior. The observed effects are explained by calculations based on the $\mathbf{k}\cdot\mathbf{p}$ kinetic exchange model of ferromagnetism in GaMnAs. Our device inverts the conventional approach for constructing spin transistors: instead of spin-transport controlled by ordinary gates we spin-gate ordinary charge transport.Comment: 5 pages, 4 figure

Geometric frustration and concerted migration in the superionic conductor barium hydride

Authors would like to thank the ISIS Facility Development Studentship for funding this work. Additionally, I would like to thank ISIS Neutron and Muon Source for providing the beam time to collect all the scattering data presented in this paper. Finally, I would like to thank the Crockett Scholarship for supporting my studies. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) license to any Accepted Author Manuscript version arising.Ionic conductivity is a phenomenon of great interest, not least because of its application in advanced electrochemical devices such as batteries and fuel cells. While lithium, sodium, and oxide fast ion conductors have been the subjects of much study, the advent of hydride (H–) ion fast conductors opens up new windows in the understanding of fast ion conduction due to the fundamental simplicity of the H– ion consisting of just two electrons and one proton. Here we probe the nature of fast ion conduction in the hydride ion conductor, barium hydride (BaH2). Unusually for a fast ion conductor, this material has a structure based upon a close-packed hexagonal lattice, with important analogues such as BaF2 and Li2S. We elucidate how the structure of the high temperature phase of BaH2 results in a disordered hydride sublattice. Furthermore, using novel combined quasi-elastic neutron scattering (QENS) and electrochemical impedance spectroscopy (EIS) we show how the high energy ions interact to create a concerted migration that results in macroscopic superionic conductivity via an interstitialcy mechanism.Publisher PDFPeer reviewe

Realisation of Hardy's Thought Experiment

We present an experimental realisation of Hardy's thought experiment [Phys. Rev. Lett. {\bf 68}, 2981 (1992)], using photons. The experiment consists of a pair of Mach-Zehnder interferometers that interact through photon bunching at a beam splitter. A striking contradiction is created between the predictions of quantum mechanics and local hidden variable based theories. The contradiction relies on non-maximally entangled position states of two particles.Comment: 5 page