'Easy to treat' genotypes were not created equal: can rapid virological response (RVR) level the playing field?

Genotypes 2 and 3 (G2/G3) of hepatitis C virus have been lumped together as 'easy to treat'. As a result, guidelines recommend 24 weeks of peginterferon/ribavirin for both. However, a closer look at trials shows that these genotypes are not the same, with G2 infection proving more responsive to peginterferon. The data supporting this conclusion are presented along with possible explanations for the differences observed. Ultimately, decisions must be made about therapy. Rapid virological response (RVR) may be the best parameter predicting successful antiviral therapy. For patients with G2 infection who achieve an RVR, shortened courses of therapy are effective. In contrast, for G3 patients without an RVR, there may be benefit to extending therapy to 48 weeks; however, this requires confirmation in prospective studies. Using RVR to guide therapy may level the playing field between these 'easy to treat' genotypes.

SiGe nanowire field effect transistors.

Si0.5Geo0.5 nanowires have been utilized to fabricate source-drain channels of p-type field effect transistors (p-FETs). These transistors were fabricated using two methods, focused ion beam (FIB) and electron beam lithography (EBL). The electrical analyses of these devices show field effect transistor characteristics. The boron-doped SiGe p-FETs with a high-k (HfO2) insulator and Pt electrodes, made via FIB produced devices with effective hole mobilities of about 50 cm2V(-1)s(-1). Similar transistors with Ti/Au electrodes made via EBL had effective hole mobilities of about 350 cm2V(-1)s(-1).

SiGe nanowire growth and characterization.

Single-crystal SiGe nanowires were synthesized via the vapour-liquid-solid (VLS) growth mechanism using disilane and germane as precursor gases. We have investigated the effect of temperature, pressure, and the inlet gas ratio on the growth and stoichiometry of Si(x)Ge(1-x) nanowires. The nanowires were characterized using scanning and transmission electron microscopies and energy dispersive x-ray analysis. It was found that nanowires with a Si:Ge ratio of about 1 had smooth surfaces, whereas departure from this ratio led to rough surfaces. Electrical properties were then investigated by fabricating back-gated field effect transistors (using a focused ion beam system) where single SiGe nanowires served as the conduction channels. Gated conduction was observed although resistance in the undoped devices was high.

Oximeter's acquisition parameter influences the profile of respiratory disturbances.

STUDY OBJECTIVES: Pulse oximetry (Sp02) is a key parameter monitored during polysomnographic studies, and different acquisition settings can be employed to obtain this data. The purpose of this study was to determine if the use of different settings would significantly influence scoring of respiratory disturbance events (RDE). DESIGN: Prospective study SETTING: Sleep Disorders Center - community PATIENTS: 30 patients had three identical oximeters simultaneously attached to the digits during polysomnography, each placed in a different recording setting: 3, 6 and 12 seconds. INTERVENTIONS: None. MEASUREMENTS: RDEs were identified by changes in snoring and flow then sub-categorized as RDE0, RDE1-2 and/or RDE3 if less than 1%, greater than 1 but less than 3%, and 3% or greater oxyhemoglobin desaturation occurred. Each event was given three labels according to the level of desaturation seen on each oximetry tracing. RESULTS: Significant differences in the mean frequency of RDE types at each recording setting were noted (p < .001). A survey of sleep practitioners revealed changes in clinical behavior when presented examples of such differences. CONCLUSION: These data confirm the impact of different oximetric recording settings on the profile of RDEs and the importance of reporting such acquisition settings in studies of sleep disordered breathing.