Trace gas measurement with an integrated porous tube collector/long-path absorbance detector

Porous membrane tubes filled with an absorbing solution that change colors upon selective reactions with specific gases provide high sensitivity inexpensive gas sensors. These can be routinely used for ambient monitoring in a fully automated manner. We consider both stopped and continuous flow operations and show the superiority of the stopped flow mode theoretically and experimentally. Light throughput through various membrane tubes is presented, and superior performance of such tubes over Teflon AF is shown. Sensors for NO2 and for O3 were based on Griess-Saltzman and indigotrisulfonate chemistries, respectively. A computer-controlled two-LED absorbance measurement system (one wavelength monitors the signal, the other references the system) that also governs automated reagent refilling was implemented. Sub-parts-per-billion-volume detection limits are attainable within a few minutes for both gases. Comparative data with a commercial UV-photometry-based ozone monitor showed excellent agreement with the response pattern of the present instrument. Low cost, ready applicability to the measurement of different gases by merely changing the light source and chemistry, and high sensitivity makes this instrument attractive for both pedagogic and practical purposes.     

Possible 3He Boltzmann Gas Formed on Three-Dimensional Nanopores Preplated with 4He

We have measured the heat capacity of ³He adsorbed on three-dimensionally connected nanopores, 2.7 nm in diameter, preplated with about 1.3 atomic layers of ⁴He. At low coverages of ³He, the ³He heat capacity is roughly constant at the measured temperatures between 0.1 and 1 K. Its molar heat capacity is on the order of the gas constant R, between 1.1R and 1.8R. This suggests a Boltzmann gas state of the adsorbed ³He. At high coverages, the heat capacity is likely approaching linear in T at low temperatures, which suggests a degenerate state at further lower temperatures.     

Design and evaluation of robot patient for nursing skill training in patient transfer

We developed a robot patient for patient transfer training for simulating a patient’s performance during patient transfer and for enabling nurses to practice their nursing skills on it. To realize the robot patient, we focused on addressing the problems of designing its limb actions to enable it to respond to nurses’ operations. RC servos and electromagnetic brakes were installed in the joints to enable the robot to simulate a patient’s limb actions, such as embracing and remaining standing. To enable the robot to automatically respond to nurses’ operations, an identification method for these operations was developed that used voice commands and the features of the limbs’ posture measured by angle sensors installed in the robot’s joints. The robot patient’s performance was examined by a control test in which four experienced nursing teachers performed patient transfer with the robot patient and a human-simulated patient. The results revealed that the robot patient could successfully simulate the actions of a patient’s limbs according to the nursing teachers’ operations and that it is suitable for nursing skill training.     

Nonequilibrium Carrier Dynamics Studied in Underdoped Bi2212 by Polarized Optical Pump-Probe Spectroscopy

We investigate nonequilibrium quasiparticle dynamics measured by ultrafast optical spectroscopy on underdoped Bi2212 crystals, which provide direct evidence that superconducting (SC) and pseudogap (PG) quasiparticles coexist below T _c . We verify that the ratio of signals from SC and PG quasiparticles depends on both excitation energy and polarization of the probe beam due to the anisotropy of the probe transition matrix elements and the interband transition probability. Based on this property, we successfully separate the SC or PG component and precisely evaluate the temperature dependence of them across T _c .     

Single-mode behavior of a circular grating for potentialdisk-shaped DFB lasers

The reflectivity and the resonance condition of a circular grating for a disk-shaped distributed-feedback (DFB) laser are calculated. The periodicity and the position of the grating are so chosen that all of the reflections from each refractive index step are superimposed in-phase so as to be consistent with the resonant behavior of the fundamental mode wave. The calculated wave impedance (E/H ) is almost purely imaginary in the central region of the grating for the higher modes     

One-Dimensional Phonon State of 4He Films Adsorbed in Straight Nanopores

We have studied heat capacities of ⁴He adsorbed in straight nanopores 1.8, 2.2, and 2.8 nm in diameter. Heat capacities of the ⁴He fluid film on the solid layer at 0.08–0.4 K show power laws close to T in 1.8 nm pores, close to T ² in 2.8 nm pores, and a crossover from T to T ² with increasing temperature in 2.2 nm pores. These heat capacities are explained by a model assuming a phonon dispersion with continuous one-dimensional (1D) states in the axial direction and discrete energy levels in the azimuthal direction. By fitting experimental data to the model, the phonon velocity along the pore axis and the energy gap for propagation in the cross section are derived. At temperatures sufficiently lower than the energy gap, where the thermal wave length of phonons is much longer than the effective pore diameter, the ⁴He fluid films show a T-linear heat capacity of 1D phonons propagating only along the pore axis. At higher temperatures, a 1D-2D crossover of phonons occurs.      

Recombinant Long-Acting Thioredoxin Ameliorates AKI to CKD Transition via Modulating Renal Oxidative Stress and Inflammation

An effective strategy is highly desirable for preventing acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Thioredoxin-1 (Trx), a redox-active protein that has anti-oxidative and anti-inflammatory properties, would be a candidate for this but its short half-life limits its clinical application. In this study, we examined the renoprotective effect of long-acting Trx that is comprised of human albumin and Trx (HSA-Trx) against AKI to CKD transition. AKI to CKD mice were created by renal ischemia-reperfusion (IR). From day 1 to day 14 after renal IR, the recovery of renal function was accelerated by HSA-Trx administration. On day 14, HSA-Trx reduced renal fibrosis compared with PBS treatment. At the early phase of fibrogenesis (day 7), HSA-Trx treatment suppressed renal oxidative stress, pro-inflammatory cytokine production and macrophage infiltration, thus ameliorating tubular injury and fibrosis. In addition, HSA-Trx treatment inhibited G2/M cell cycle arrest and apoptosis in renal tubular cells. While renal Trx protein levels were decreased after renal IR, the levels were recovered by HSA-Trx treatment. Together, HSA-Trx has potential for use in the treatment of AKI to CKD transition via its effects of modulating oxidative stress and inflammation.     

PZT MIM capacitor with oxygen-doped Ru-electrodes for embedded FeRAM devices

An add-on-type, Pb(Zr,Ti)O/sub 3/ (PZT) metal-insulator- (MIM) capacitor on Al multilevel interconnects is developed for embedded FeRAM devices, concluding that the oxygen-doping into the ruthenium (Ru) electrodes is crucial for obtaining large remnant polarization under a limited process temperature below 450/spl deg/C. The oxygen-doped, Ru bottom-electrode with a granular structure reduces the PZT sputtering temperature below 450/spl deg/C to obtain the ferroelectric perovskite-phase. On the other hand, oxygen doping into the Ru top-electrode suppresses the reductive damage at the interface between the top-electrode and the PZT, keeping the leakage current low. The PZT MIM capacitor with these oxygen-doped, Ru electrodes exhibits the remnant polarization of 21 /spl mu/C/cm/sup 2/ on the Al multilevel interconnects with no degradation of the interconnect reliability, thus applicable to the embedded FeRAM in 0.25 /spl mu/m-CMOS logic LSIs.