Hepatitis B virus with X gene mutation is associated with the majority of serologically "silent" non-b, non-c chronic hepatitis

Hepatitis B virus (HBV) with X gene mutations has been a putative pathogen of chronic hepatitis without serological markers of known hepatitis viruses. The aim of this study was to reconfirm whether the HBV with the X gene mutation is associated with these serologically "silent" non-B, non-C (NBNC) chronic hepatitis, alcoholic liver disease (ALD) and autoimmune hepatitis (AIH). HBV DNA was amplified from serum and sequenced in 30 patients with NBNC chronic hepatitis in comparison with 20 patients with ALD and 5 patients with AIH. HBV DNA was identified in 21 patients (70%) in NBNC chronic hepatitis by nested polymerase chain reaction while only one patient (5%) in ALD and none in AIH showed HBV DNA. Eighteen (85.7%) of the 21 identified HBV DNAs had an identical 8-nucleotide deletion mutation at the distal part of the X region. This mutation affected the core promoter and the enhancer II sequence of HBV DNA and created a translational stop codon which truncated the X protein by 20 amino acids from the C-terminal end. All the HBV DNAs had a precore mutation at the 83rd nucleotide resulting in disruption of HBe antigen synthesis. These results indicate that HBV mutants are closely associated with the majority of serologically "silent" NBNC chronic hepatitis cases and the population of such mutant HBV DNAs is not uniform.     

Photoelectron emission from heavily B-doped homoepitaxial diamond films

We discuss the energy band structure near the valence band maximum based on photoemission yield spectroscopy experiments using a hydrogen-terminated heavily boron-doped homoepitaxial diamond film with concentration of 3 × 10²⁰ cm^− 3. The experimental results showed a metallic photoemission behavior with a negative electron affinity surface. Based on the fitting as metallic photoemission behavior with a Fowler plot, the Fermi level should be at 5.35 eV below the conduction band minimum, which means that the Fermi level lies at 0.12 eV (5.47–5.35 eV) above the valence band maximum. Thus the film shows metallic conduction by the Mott transition, but not as degenerate semiconductor.     

The DeltaUp constraint solver: minimizing the number of method selections in DeltaBlue

We present a modification of the DeltaBlue constraint solver called DeltaUp. DeltaBlue is an incremental constraint solver based on local propagation, which is widely used for constructing graphical user interfaces and algorithm animations. DeltaUp minimizes the number of time‐consuming tasks of DeltaBlue, namely method selections, in each planning phase. To compute the exact number of needed method selections, we introduced a cost function up‐cost to DeltaBlue. Our benchmarks show that DeltaUp is approximately two times faster than DeltaBlue in the best case. Even in the worst case, it is only slightly slower than DeltaBlue. Copyright © 2001 John Wiley & Sons, Ltd.     

Guardring-Free Planar AlInAs Avalanche Photodiodes for 2.5-Gb/s Receivers With High Sensitivity

We demonstrate a practical 2.5-Gb/s AlInAs avalanche photodiode (APD) and an AlInAs APD-based optical receiver with high sensitivity. The AlInAs APD has a simple guardring-free planar structure with high reliability. In addition to the inherent low excess noise of AlInAs, their simplicity and high yields are great advantages in production, even when contrasted with the planar InP APDs now on the market. The guardring-free AlInAs APDs achieve larger gain-bandwidth (GB) products and lower excess noise, with a maximum 3-dB bandwidth of 6.0 GHz and a GB product of typically 80 GHz, and have equal performance with InP APDs, which have a responsivity of 1.0 A/W and a multiplying dark current of 2.2 nA. An AlInAs APD-based 2.5-Gb/s optical receiver with a SiGe transimpedance amplifier has a sensitivity of -37.0 dBm at a bit-error rate of 10^-10     

Thermal analysis of a low flow piezoelectric air pump

With the propagation of ever faster and more powerful electronics, the need for active, low power cooling is becoming apparent. In particular, applications which have traditionally relied only on natural convection will soon require an active cooling solution due to continually rising heat loads. A promising solution lies in utilizing piezoelectric materials via fans or pumps. Examples of such devices include synthetic jets and piezoelectric pumps, both of which rely on an oscillating diaphragm to induce flow. The device under investigation in this paper is able to generate flow rates up to 1 L/min and overcome pressures of over 2 kPa. The focus is to experimentally characterize the cooling potential of a piezoelectric-based air pump oriented normal to the heated element, an environment similar to jet impingement. Experimental characterizations were made through the use of a thin film heater which provided a constant heat flux while an infrared camera was used to capture the resulting temperature field of the heated surface. Full-field data of the convection coefficient was analyzed as a function of vibration amplitude of the piezoelectric diaphragm and distance from the nozzle to the heated target. The maximum heat transfer coefficient was found to always be at the stagnation point regardless of vibration amplitude or distance to the target. Correlations have been developed which account for both variables considered and can be used to predict the performance of future designs which rely on the same physical characteristics.     

A new differential LSI space-based probabilistic document classifier

We have developed a new effective probabilistic classifier for document classification by introducing the concept of differential document vectors and DLSI (differential latent semantic indexing) spaces. A combined use of the projections on and the distances to the DLSI spaces introduced from the differential document vectors improves the adaptability of the LSI (latent semantic indexing) method by capturing unique characteristics of documents. Using the intra- and extra-document statistics, both a simple posteriori calculation on a small example and an experiment on a large Reuters-21578 database demonstrate the advantage of the DLSI space-based probabilistic classifier over the LSI space-based classifier in classification performance.     

A highly sensitive method for quantifying gallocatechin gallate and its epimer using a catechin-specific peptide

We have developed a method for quantifying gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) using a catechin-binding peptide (part of the 67-kDa laminin receptor). Using micro titer plates, we investigated various conditions, including the quantifiable range of EGCg concentrations, the optimal concentration of the catechin-binding peptide, and the optimal reaction conditions. In this microplate assay, after each well was coated with bovine serum albumin, sample containing GCg and EGCg was added at pH 8.0, and allowed to stand at 37 °C for 2 h. After washing, biotinylated-peptide solution was added at 1 μg mL^?1 and allowed to react for 1 h at 37 °C. Each well was added with streptavidin–horseradish peroxidase conjugate, followed by chromogenic reaction for 25 min at room temperature. After the reaction, absorbance was measured at 405 nm. Our method is capable of quantifying EGCg in the range of approximately 0.1–2.0 mg L^?1 with a high degree of sensitivity and a high correlation (R² = 0.98) between EGCg concentration and absorbance. The method was specific to GCg and EGCg and seems capable of estimating GCg and EGCg contents in the presence of other catechin compounds. The method is simple and highly sensitive for quantitative GCg and EGCg measurement that requires no special equipment or operation and can measure multiple samples simultaneously.     

Induced absorption in X-ray-irradiated CdS- and CdSSe-doped glasses

Optical transmission spectra of X-ray-irradiated CdS- and CdSSe-doped glasses and undoped glass have been measured. Induced absorption has been observed in these glasses. In addition to the radiation-induced absorption increment, decrease in absorption has been observed near absorption edge in CdSSe-doped glasses. Origin of the decrease in absorption was examined.