Nuclear inelastic scattering spectroscopy of iron-sulfur cubane compounds

The potential of NIS spectroscopy to study the iron-sulfur clusters in metalloproteins is illustrated using model compounds. The origin of the intense low energy transfer bands is discussed.     

High precision measurement of the superallowed 0+ --> 0+ beta decay of 22Mg

The half-life, 3.8755(12) s, and superallowed branching ratio, 0.5315(12), for 22Mg beta decay have been measured with high precision. The latter depended on gamma-ray intensities being measured with an HPGe detector calibrated for relative efficiencies to an unprecedented 0.15%. Previous precise measurements of 0+ --> 0+ transitions have been restricted to the nine that populate stable daughter nuclei. No more such cases exist, and any improvement in a critical Cabibbo-Kobayashi-Maskawa unitarity test must depend on precise measurements of more exotic nuclei. With this branching-ratio measurement, we show those to be possible for T(z)=-1 parents. We obtain a corrected Ft value of 3071(9) s, in good agreement with expectations.     

Fully Entangled Quantum States in C^{N^2 } and Bell Measurement

Entangled quantum states are an important component of quantum computing techniques such as quantum error-correction, dense coding, and quantum teleportation. We describe how to generate fully entangled states in the Hilbert space C ^N C ^N starting from a unitary matrix and show that they form an orthonormal basis in this space.     

Observation of the transverse optical plasmon in SmLa0.8Sr0.2CuO4-delta

We present microwave and infrared measurements on SmLa0.8Sr0.2CuO4-delta, which are direct evidence for the existence of a transverse optical plasma mode, observed as a peak in the c-axis optical conductivity. This mode appears as a consequence of the existence of two different intrinsic Josephson couplings between the CuO2 layers, one with a Sm2O2 block layer, and the other one with a (La,Sr)2O2-delta block layer. From the frequencies and the intensities of the collective modes we determine the value of the compressibility of the two dimensional electron fluid in the copper oxygen planes.     

Fast MAS total through-bond correlation spectroscopy

Mixing sequences for total through-bond correlation spectroscopy in solids (TOBSY) were developed. The motivation is the design of broadband, effective, and robust sequences adapted for "fast" MAS. Possible sequences with the desired Hamiltonian (the homonuclear isotropic J interaction) were identified using lowest order average Hamiltonian theory. Numerical simulations as a function of the MAS frequency were then employed to further characterize the performance. An experimental TOBSY spectrum of a uniformly (13)C-labeled decapeptide at 20 kHz MAS was obtained using one of the new sequences. The spectrum allows us to assign the (13)C resonances to the respective spin systems.     

Local distinguishability of multipartite orthogonal quantum states

We consider one copy of a quantum system prepared in one of two orthogonal pure states, entangled or otherwise, and distributed between any number of parties. We demonstrate that it is possible to identify which of these two states the system is in by means of local operations and classical communication alone. The protocol we outline is both completely reliable and completely general; it will correctly distinguish any two orthogonal states 100% of the time.     

Phonon screening in high-temperature superconductors

In good conductors optical phonons are usually screened, and therefore not observed. However, sharp features due to infrared-active modes in the copper-oxygen planes are observed in the optical conductivity of Pr1.85Ce0.15CuO4 and YBa2Cu3O6.95. Oscillator strengths indicate that the screening of these modes is poor or totally absent. These materials are compared with eta-Mo4O11, in which lattice modes appear suddenly below the charge-density wave transition. It is proposed that poor screening in the cuprates originates from fluctuating charge inhomogeneities in the copper-oxygen planes.     

A phase I, randomized study of combined IL-2 and therapeutic immunisation with antiretroviral therapy

Background  

Fully functional HIV-1-specific CD8 and CD4 effector T-cell responses are vital to the containment of viral activity and disease progression. These responses are lacking in HIV-1-infected patients with progressive disease. We attempted to augment fully functional HIV-1-specific CD8 and CD4 effector T-cell responses in patients with advanced chronic HIV-1 infection.     

New insight into the role of the β3 subunit of the GABA<Subscript>A</Subscript>-R in development,behavior, body weight regulation,and anesthesia revealed by conditional gene knockout

Background  

The β3 subunit of the γ-aminobutyric acid type A receptor (GABA_A-R) has been reported to be important for palate formation, anesthetic action, and normal nervous system function. This subunit has also been implicated in the pathogenesis of Angelman syndrome and autism spectrum disorder. To further investigate involvement of this subunit, we previously produced mice with a global knockout of β3. However, developmental abnormalities, compensation, reduced viability, and numerous behavioral abnormalities limited the usefulness of that murine model. To overcome many of these limitations, a mouse line with a conditionally inactivated β3 gene was engineered.