Prospective observational study to evaluate the performance of the BioSure HIV Self-Test in the hands of lay users.

OBJECTIVES: In order to assess whether the BioSure HIV Self-Test could be reliably performed by users at home and to determine whether they were able to perform and correctly interpret the test, we carried out an evaluation study among attendees at a sexual health service. METHODS: A prospective observational study of clinic attendees to determine their ability to follow the instructions, complete the test on themselves and correctly interpret the results. The evaluation included interpretation of three dummy (contrived) devices, chosen at random from a sample of 12 devices, to ensure that a sufficient number of all possible test outcomes were included. RESULTS: Two hundred participants were recruited. 97.0% (95% CI 93.5 to 98.9) conducted the test so as to achieve a valid result. 99.5% correctly identified the test result. Participants correctly interpreted the result of 94.0% (95% CI 91.4 to 95.9) of 586 contrived devices. CONCLUSIONS: The majority of participants were able to follow the instructions and perform the test in order to get a valid result. Interpretation of the test results was good and the majority of participants were able to correctly read the result of their own and contrived tests. The availability of HIV self-tests will provide another option to increase access to testing particularly for those who may not wish or are unable to access clinical services.

Current saturation in submicrometer graphene transistors with thin gate dielectric: experiment, simulation, and theory.

Recently, graphene field-effect transistors (FET) with cutoff frequencies (f(T)) between 100 and 300 GHz have been reported; however, the devices showed very weak drain current saturation, leading to an undesirably high output conductance (g(ds)= dI(ds)/dV(ds)). A crucial figure-of-merit for analog/RF transistors is the intrinsic voltage gain (g(m)/g(ds)) which requires both high g(m) (primary component of f(T)) and low g(ds). Obtaining current saturation has become one of the key challenges in graphene device design. In this work, we study theoretically the influence of the dielectric thickness on the output characteristics of graphene FETs by using a surface-potential-based device model. We also experimentally demonstrate that by employing a very thin gate dielectric (equivalent oxide thickness less than 2 nm), full drain current saturation can be obtained for large-scale chemical vapor deposition graphene FETs with short channels. In addition to showing intrinsic voltage gain (as high as 34) that is comparable to commercial semiconductor FETs with bandgaps, we also demonstrate high frequency AC voltage gain and S21 power gain from s-parameter measurements.

CMOS-compatible synthesis of large-area, high-mobility graphene by chemical vapor deposition of acetylene on cobalt thin films.

We demonstrate the synthesis of large-area graphene on Co, a complementary metal-oxide-semiconductor (CMOS)-compatible metal, using acetylene (C(2)H(2)) as a precursor in a chemical vapor deposition (CVD)-based method. Cobalt films were deposited on SiO(2)/Si, and the influence of Co film thickness on monolayer graphene growth was studied, based on the solubility of C in Co. The surface area coverage of monolayer graphene was observed to increase with decreasing Co film thickness. A thorough Raman spectroscopic analysis reveals that graphene films, grown on an optimized Co film thickness, are principally composed of monolayer graphene. Transport properties of monolayer graphene films were investigated by fabrication of back-gated graphene field-effect transistors (GFETs), which exhibited high hole and electron mobility of ∼1600 cm(2)/V s and ∼1000 cm(2)/V s, respectively, and a low trap density of ∼1.2 × 10(11) cm(-2).