The dc current gain dependence of InGaP/GaAs heterojunction bipolar transistors (HBTs) on subcollector and etch-stop doping is examined. Samples of InGaP/GaAs HBTs having various combinations of subcollector doping and etch-stop doping are grown, and large area (60 m 60 ( ) HBTs are then fabricated for dc characterization. It is found that the dc current gain has a strong dependence on the dopi...

Electrical through-wafer interconnects (ETWI) are often integrated with inertial sensors for harsh liquid environment applications. Devices with metal interconnects are very susceptible to corrosion in aquatic environments. An alternative approach is to form highly doped, conductive polysilicon through the wafer from the back side (unexposed to harsh environments) to the front side of the devic...

We proposed a spatially resolved optical emission spectrometer (SROES) for analyzing the uniformity of plasma density for semiconductor processes. To enhance the spatial resolution of the SROES, we constructed a SROES system using a series of lenses, apertures, and pinholes. We calculated the spatial resolution of the SROES for the variation of pinhole size, and our calculated results were in g...

Resistance to virus infections in higher vertebrates is mediated in part through catalysis of RNA decay by the, interferon-regulated 2-5A system. A functional 2-5A system requires two enzymes, a 2-5A synthetase that produces 5'-phosphorylated, 2',5'-linked oligoadenylates (2-5A) in response to double-stranded RNA, and the 2-5A-dependent RNase L. We have coexpressed these human enzymes in transg...

The aim of this study was to evaluate the microtensile bond strength of self-etch adhesive systems to dentin after storage in acids from oral biofilm. Three adhesive systems were used in the study: a two-step self-etch adhesive for use with a silorane-based resin composite (Filtek P90 adhesive system - P90), a two-step self-etch adhesive (Clearfil SE Bond - CSE) and a one-step self-etch adhesiv...

Objective: To assess biofilm proliferation within the sealer-dentin interfaces of methacrylate resin-based sealers, self-etch (SE) and total-etch (TE), and an epoxy resin-based sealer (EP). Methods: Standardized human root specimens were filled with the test materials and were aged for 1 week, 1, 3 or 6 months in saline (n=3/group). Monoclonal biofilms of Enterococcus faecalis were grown on the...

microleakage can be responsible for tooth hypersensitivity, secondary caries, and the possibility of pathological pulp alterations in restored teeth. recently, alternative methods for tooth preparation such as laser irradiation have been studied; but there are limited studies on primary teeth. the aim of this in vitro study was to compare the degree of microleakage of composite restorations pre...

AIM To review the literature on the sealing ability of esthetic post systems with different cementation techniques. BACKGROUND An important factor for successful root canal treatment is the development of a coronal seal to the treated root canal system. Review result: The current literature describes promising results using fiber posts with a dual-cure, self-etch resin cement system. However,...