A numerical calculation on the basis of the Boltzmann-Poisson model clarifies that the conduction band of the i-GaAs/n-GaAs Selleckchem GW4869 sample bends upward at the surface region, which indicates that photogenerated electrons flow into the inside. In the measurement of the terahertz wave, it is observed that the polarity of the terahertz wave from the SI-GaAs crystal is the same as that of the i-GaAs/n-GaAs sample, namely, the present SI-GaAs crystal has an upward
band bending. In contrast, the terahertz-wave polarity is reversed in the GaAs1-xNx samples in spite of the relatively small nitrogen mole fraction; namely, the GaAs1-xNx samples have a downward band bending. The above-mentioned terahertz-wave polarity reversal is attributed to the phenomenon that conduction-band bottom is considerably lowered by the band anticrossing peculiar to GaAs1-xNx, which results in approaching
the conduction-band bottom to the surface Fermi level. This modifies the direction of LEE011 price the surface band bending connected with the polarity of the terahertz wave. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3125451]“
“SETTING: Twenty hospitals in Spain.
OBJECTIVE: To describe the incidence of active tuberculosis (TB) and factors related to TB development after treatment for latent tuberculous infection (TLTBI) in human immunodeficiency virus-1 (HIV-1) infected patients in the highly active antiretroviral therapy era.
DESIGN: In a multicentre cohort of HIV-1-infected patients, we calculated TB incidence selleck by tuberculin skin test
(TST) results and TLTBI, and factors associated with a positive TST and the development of TB after TLTBI.
RESULTS: Of 7902 patients, 6.5% had a history of TB at enrolment: 168 patients developed TB during 10889 person-years (py) of follow-up, corresponding to an incidence rate of 1.54 cases per 100 py (95%CI 1.33- 1.80). TB incidence in TST-positive patients who did not receive TLTBI was three times higher (6 cases/100 py) than in those who did (1.75 cases/100 py). In patients who received TLTBI, risk of development of TB was higher among cases aged <35 years (HR 6.14, 95%CI 1.12-33.73) and in those with a nadir CD4(+) cell count of <200 cells/mu l (HR 5.64, 95%CI 1.34-23.70).
CONCLUSIONS: TLTBI is effective in preventing the development of TB in HIV-infected patients, particularly in those who were TST-positive.”
“A prototype of Ni-Mn-Ga based ferromagnetic-shape-memory-alloy (FSMA) actuator was designed and built; an acoustic-assist technique was applied to the actuator to enhance its performance. A piezoelectric stack actuator was attached to the Ni-Mn-Ga sample to generate acoustic energy to enhance twin-boundary mobility and, hence, reduce the magnetic threshold field required for activating twin-boundary motion.