A Schottky/2-DEG varactor diode for millimeter and submillimeter wave multiplier applications

A new Schottky diode is investigated for use as a multiplier element in the millimeter and submillimeter wavelength regions. The new diode is based on the Schottky contact at the edge of a 2-dimensional electron gas (2-DEG). As a negative voltage is applied to the Schottky contact, the depletion layer between the Schottky contact and the 2-DEG expands and the junction capacitance decreases, resulting in a nonlinear capacitance-voltage characteristic. In this paper, we outline the theory, design, fabrication, and evaluation of the new device. Recent results include devices having cutoff frequencies of 1 THz and above. Preliminary multiplier results are also presented

Demonstration of safety of intravenous immunoglobulin in geriatric patients in a long-term, placebo-controlled study of Alzheimer's disease.

INTRODUCTION:We present safety results from a study of Gammagard Liquid intravenous immunoglobulin (IGIV) in patients with probable Alzheimer's disease. METHODS:This was a placebo-controlled double-blind study. Subjects were randomized to 400 mg/kg (n = 127), 200 mg/kg (n = 135) IGIV, or to 0.25% human albumin (n = 121) administered every 2 weeks ± 7 days for 18 months. RESULTS:Elevated risk ratios of IGIV versus placebo included chills (3.85) in 9.5% of IGIV-treated subjects (all doses), compared to 2.5% of placebo-treated subjects, and rash (3.08) in 15.3% of IGIV-treated subjects versus 5.0% of subjects treated with placebo. Subjects in the highest IGIV dose group had the lowest proportion of SAEs considered related to product (2 of 127 [1.6%]). Subjects treated with IGIV experienced a lower rate of respiratory and all other infections compared to placebo. DISCUSSION:IGIV-treated subjects did not experience higher rates of renal failure, lung injury, or thrombotic events than the placebo group. There were no unexpected safety findings. IGIV was well tolerated throughout 18 months of treatment in subjects aged 50-89 years

Efficacy, safety, tolerability and pharmacokinetics of a novel human immune globulin subcutaneous, 20%: a Phase 2/3 study in Europe in patients with primary immunodeficiencies

A highly concentrated (20%) immunoglobulin (Ig)G preparation for subcutaneous administration (IGSC 20%), would offer a new option for antibody replacement therapy in patients with primary immunodeficiency diseases (PIDD). The efficacy, safety, tolerability and pharmacokinetics of IGSC 20% were evaluated in a prospective trial in Europe in 49 patients with PIDD aged 2-67 years. Over a median of 358 days, patients received 2349 IGSC 20% infusions at monthly doses equivalent to those administered for previous intravenous or subcutaneous IgG treatment. The rate of validated acute bacterial infections (VASBIs) was significantly lower than 1 per year (0.022/patient-year, P /= 8 g/l. There was no serious adverse event (AE) deemed related to IGSC 20% treatment; related non-serious AEs occurred at a rate of 0.101 event/infusion. The incidence of local related AEs was 0.069 event/infusion (0.036 event/infusion, when excluding a 13-year-old patient who reported 79 of 162 total related local AEs). The incidence of related systemic AEs was 0.032 event/infusion. Most related AEs were mild, none were severe. For 64.6% of patients and in 94.8% of IGSC 20% infusions, no local related AE occurred. The median infusion duration was 0.95 (range = 0.3-4.1) h using mainly one to two administration sites [median = 2 sites (range = 1-5)]. Almost all infusions (99.8%) were administered without interruption/stopping or rate reduction. These results demonstrate that IGSC 20% provides an effective and well-tolerated therapy for patients previously on intravenous or subcutaneous treatment, without the need for dose adjustment

Adiabatic perturbation theory: from Landau-Zener problem to quenching through a quantum critical point

We discuss the application of the adiabatic perturbation theory to analyze the dynamics in various systems in the limit of slow parametric changes of the Hamiltonian. We first consider a two-level system and give an elementary derivation of the asymptotics of the transition probability when the tuning parameter slowly changes in the finite range. Then we apply this perturbation theory to many-particle systems with low energy spectrum characterized by quasiparticle excitations. Within this approach we derive the scaling of various quantities such as the density of generated defects, entropy and energy. We discuss the applications of this approach to a specific situation where the system crosses a quantum critical point. We also show the connection between adiabatic and sudden quenches near a quantum phase transitions and discuss the effects of quasiparticle statistics on slow and sudden quenches at finite temperatures.Comment: 20 pages, 3 figures, contribution to "Quantum Quenching, Annealing and Computation", Eds. A. Das, A. Chandra and B. K. Chakrabarti, Lect. Notes in Phys., Springer, Heidelberg (2009, to be published), reference correcte

A BIO-MOLECULAR ARCHITECTURAL CONCEPT FOR ENHANCED SENSING OF BIO-SIGNATURES

Author Institution: University of Virginia; Army Research Laboratory, Army Research OfficeRecent research has demonstrated the potential use of terahertz (THz) frequency transmission spectroscopy as a technique for the detection, identification and characterization of biological agents. However, while adequate levels of sensitivity appear to be demonstrated even for remote detection applications, the viability of THz spectroscopy for biological sensing (i.e., point and remote) will ultimately hinge on the level of reliable discrimination it can provide. Two challenges arise within this context. First, there are a reasonably limited number of spectral signatures (i.e., $\preceq 100$) associated with any bio-agent in its natural state and, second, the strong atmospheric absorption limits the sensitivity of the approach at all but a few THz-band transmission channels. However, it is possible to envision bio-molecular electronic architectures that can be effectively utilized for sensing and processing of bio-signature data. The novelty of this approach lies in the strategic use of integrated biological elements to achieve higher-level function and spectral data processing within a nanoscale and molecular-level architecture. An overview of this new bio-molecular architectural concept will be presented along with a report on the initial theoretical studies that are underway for defining the functional bio-molecular components. Hence, this presentation will define a new and novel approach for enhancing the spectral sensing of bio-signatures at THz frequencies