Giant capacitance of a plane capacitor with a two-dimensional electron gas in a magnetic field

If a clean two-dimensional electron gas (2DEG) with small concentration $n$ comprises one (or both) electrodes of a plane capacitor, the resulting capacitance $C$ can be larger than the "geometric capacitance" $C_g$ determined by the physical separation $d$ between electrodes. A recent paper [1] argued that when the effective Bohr radius $a_B$ of the 2DEG satisfies $a_B << d$, one can achieve $C >> C_g$ at low concentration $nd^2 << 1$. Here we show that even for devices with $a_B > d$, including graphene, for which $a_B$ is effectively infinite, one also arrives at $C >> C_g$ at low electron concentration if there is a strong perpendicular magnetic field.Comment: 6 pages, 5 figures; updated discussion about bilayer systems; added discussion of fractional quantum Hall state

CIN2+ detection of the HPV DNA Array genotyping assay in comparison with the Cobas 4800 HPV test and cytology

BACKGROUND: HPV DNA Array is an E1-targeting PCR genotyping test, with capability of distinguishing 18 high-risk (16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 82) and 11 low-risk HPV types (6, 11, 40, 42, 44, 54, 67, 69, 70, 85, 97). HPV DNA Array uses multiplex PCR for E1-gene sequence amplification. The amplicons are detected and genotyped by reverse hybridization to immobilized DNA probes spotted as triplets in single 96 well-plate wells and read by AID ELISPOT reader. METHODS: Aim of the study was to evaluate the clinical performance of the assay against internationally accepted and FDA approved Cobas 4800 HPV test (Roche Diagnostics). Study population comprised of 500 cervical samples. RESULTS: HPV DNA Array demonstrated a very high sensitivity of 100% for CIN2+ and 100% for CIN3+ detection, same as Cobas 4800. HPV DNA Array showed greater sensitivity for CIN2+ detection than cytology (100% vs. 13.6%). The agreement to Cobas 4800 for HPV detection, irrespective of type, was 81.4% with κ = 0.613. The agreement for HPV 16 was 92.8% (κ = 0.929), and for HPV 18 54.2% (κ = 0.681). CONCLUSION: HPV DNA Array demonstrated good clinical performance for detection of high-grade lesions, and may be considered for usage in a screening setting

A new species of the genus <i>Atelopsalis</i> (Acari: Halacaridae) from Zanzibar, Tanzania

A new halacarid species belonging to the genus Atelopsalis is described from the east coast of Zanzibar,Tanzania. Atelopsalis zanzibari sp. nov. is characterized by an anterior areola and two longitudinal costae on anterior dorsal plate, posterior dorsal plate with four costae, genu I with one spine, genu II devoid of spine. This is the first report of the genus Atelopsalis from Tanzania

Clinical performance of the HPV DNA Array genotyping assay in detection of CIN2+ lesions with BS GP5+/6+ MPG Luminex tested cervical samples

Human papillomavirus (HPV) detection is used for screening of cervical cancer and genotype-specific persistence has shown to be mandatory for dysplasia development. Aim of this study was to evaluate the clinical performance of HPV DNA Array for cervical intraepithelial neoplasia 2+ (CIN2+) lesion detection. HPV DNA Array is a polymerase chain reaction-based assay that targets E1 sequences of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97). The clinical evaluation was performed against the reference assay, BS-GP5+/6+ multiplex genotyping (MPG)-Luminex, with 600 cervical smear samples of a referral population. HPV DNA Array detected CIN2+ lesions with a sensitivity of 90.2%, identical to that of MPG-Luminex. Detection of CIN3+ lesions was with a sensitivity of 90.3%, as compared with 88.7% of MPG-Luminex. It demonstrated very good agreement for HPV detection, irrespective of type, of 91.5% (kappa = 0.832). HPV DNA Array is a simple and robust assay, with a short protocol of 4 hours hands-on time and automated readout by ELISpot AiDot software. It permits testing of up to 96 samples in one run and may be considered for use in organized screening programs and low resource settings