In order to evaluate the effectiveness of CdTe surface passivating layers, HgCdTe photoconductors with and without CdTe sidewall passivation were fabricated. As expected, photoconductors with CdTe ...sidewall passivation demonstrated significantly higher responsivity in comparison with those without sidewall passivation, indicating the effectiveness of molecular-beam epitaxially (MBE)-grown CdTe as a passivation layer in reducing surface recombination velocity. Characterization of the responsivity differences between photoconductors with and without sidewall CdTe passivation offers a potential method for measuring the interface/surface recombination velocity. This has been demonstrated in this paper by extracting the value of the surface recombination velocity using the Synopsys Sentaurus commercial modeling package to fit experimental responsivity data for fully and partially passivated devices.
The electrical properties of semiconductor materials have conventionally been extracted via Hall measurements performed at a single magnetic field. When applied to a semiconductor such as HgCdTe with ...mixed conduction characteristics, the values obtained from the Hall measurement represent only an averaged contribution of all carriers present in the sample. In this study, the transport properties of a liquid-phase epitaxially (LPE) grown p-type HgCdTe were determined. Variable magnetic field and temperature Hall and resistivity measurements were employed in conjunction with the improved-quantitative mobility spectrum analysis (iQMSA) algorithm to extract the concentrations and mobilities of all carriers present in the material. A comparison study was made between a van der Pauw Greek cross and a standard Hall bar structure on the same material. A disparity in the transport property of the sample was observed when both structures were measured within a few days of each other. Through iQMSA analysis, the discrepancy is seen to be attributed to the formation of an n-type skin inversion layer within a week after processing.
Interleukin-17A is considered to be central to the pathogenesis of psoriasis. We evaluated secukinumab, a fully human anti-interleukin-17A monoclonal antibody, in patients with moderate-to-severe ...plaque psoriasis.
In two phase 3, double-blind, 52-week trials, ERASURE (Efficacy of Response and Safety of Two Fixed Secukinumab Regimens in Psoriasis) and FIXTURE (Full Year Investigative Examination of Secukinumab vs. Etanercept Using Two Dosing Regimens to Determine Efficacy in Psoriasis), we randomly assigned 738 patients (in the ERASURE study) and 1306 patients (in the FIXTURE study) to subcutaneous secukinumab at a dose of 300 mg or 150 mg (administered once weekly for 5 weeks, then every 4 weeks), placebo, or (in the FIXTURE study only) etanercept at a dose of 50 mg (administered twice weekly for 12 weeks, then once weekly). The objective of each study was to show the superiority of secukinumab over placebo at week 12 with respect to the proportion of patients who had a reduction of 75% or more from baseline in the psoriasis area-and-severity index score (PASI 75) and a score of 0 (clear) or 1 (almost clear) on a 5-point modified investigator's global assessment (coprimary end points).
The proportion of patients who met the criterion for PASI 75 at week 12 was higher with each secukinumab dose than with placebo or etanercept: in the ERASURE study, the rates were 81.6% with 300 mg of secukinumab, 71.6% with 150 mg of secukinumab, and 4.5% with placebo; in the FIXTURE study, the rates were 77.1% with 300 mg of secukinumab, 67.0% with 150 mg of secukinumab, 44.0% with etanercept, and 4.9% with placebo (P<0.001 for each secukinumab dose vs. comparators). The proportion of patients with a response of 0 or 1 on the modified investigator's global assessment at week 12 was higher with each secukinumab dose than with placebo or etanercept: in the ERASURE study, the rates were 65.3% with 300 mg of secukinumab, 51.2% with 150 mg of secukinumab, and 2.4% with placebo; in the FIXTURE study, the rates were 62.5% with 300 mg of secukinumab, 51.1% with 150 mg of secukinumab, 27.2% with etanercept, and 2.8% with placebo (P<0.001 for each secukinumab dose vs. comparators). The rates of infection were higher with secukinumab than with placebo in both studies and were similar to those with etanercept.
Secukinumab was effective for psoriasis in two randomized trials, validating interleukin-17A as a therapeutic target. (Funded by Novartis Pharmaceuticals; ERASURE and FIXTURE ClinicalTrials.gov numbers, NCT01365455 and NCT01358578, respectively.).
Extrinsic p-type doping of Mercury Cadmium Telluride (HgCdTe) epilayers grown by Molecular Beam Epitaxy (MBE) was carried out with an arsenic (As) cracker cell. As-grown samples were characterised ...via Fourier Transform Infrared Transmission Spectrometry (FTIR) and Secondary Ion Mass Spectrometry (SIMS). A preliminary study on various activation annealing techniques is made, where HgCdTe layers were annealed under Hg overpressures in a closed tube furnace at varying temperatures to either activate arsenic and/or, to eliminate Hg vacancies. Variable field magneto-transport measurements coupled with the quantitative mobility spectrum analysis (QMSA) were then utilised to study the Hall effect characteristics of the annealed material.
The semiconductor-passivating layer interfaces, as well as their dielectric properties, play important and very often dominant roles in determining HgCdTe device performance. In this work, ...photoconductors were fabricated on p-type mid-wave infrared Hg 1-x Cd x Te material using molecular beam epitaxy (MBE) grown CdTe film as the passivation layer. In order to emphasize the importance of the CdTe passivating layer, HgCdTe photoconductors with and without the sidewall CdTe passivation were fabricated. The photoconductor with its sidewalls passivated shows significantly higher responsivity than the one without sidewall passivation. Conductance-voltage characteristics of capacitor using CdTe between HgCdTe and metal contacts were made in studying insulating property of the passivation film. Scanning electron microscopy (SEM) micrographs and X-ray diffraction (XRD) spectra were included in order to investigate the structural properties of the CdTe passivation film.
Extrinsic p-type doping of Mercury Cadmium Tel-luride (HgCdTe) epilayers grown by Molecular Beam Epitaxy (MBE) was carried out with an arsenic (As) cracker cell. As-grown samples were characterised ...via Fourier Transform Infrared Transmission Spectrometry (FTIR), Secondary Ion Mass Spectrometry (SIMS) as well as variable field magneto-transport measurements coupled with the quantitative mobility spectrum analysis (QMSA) to study the Hall effect characteristics. Arsenic activation annealing of the samples were performed and magneto-transport measurements repeated. Results indicate that as-grown samples show n-type behaviour indicating that arsenic incorporate as donors in the material with annealed samples showing p-type characteristics with heavy compensation.
From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 ...samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan.
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