The elimination of hepatitis B virus infection: changing seroepidemiology of hepatitis A and B virus infection in Okinawa, Japan over a 26-year period

Serial changes in hepatitis A virus (HAV) and B virus (HBV) markers were determined from 1970 to 1996 in healthy Japanese residents of a rural area of Okinawa, Japan. All 190 serum samples taken in 1970, 791 in 1980, 708 in 1988, and 523 in 1996 from residents 0 to more than 60 years of age were tested for antibody to HAV (anti-HAV), antibody to hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg). The age-adjusted prevalences of anti-HAV and anti-HBc decreased significantly from 83.9% and 74.9%, respectively, in 1970 to 39.7% and 36.6%, respectively, in 1996. In residents < or = 29 years of age, the prevalences of anti-HAV and anti-HBc decreased significantly from 65.3% and 83.8%, respectively, in 1970 to 0.7% and 8.2%, respectively, in 1996. The age-adjusted HBsAg prevalence decreased significantly from 8.2% in 1980 to 4.1% in 1988. These results indicate that exposure to HAV and HBV infections among Okinawa residents less than 29 years of age is decreasing, probably because of improvements in socioeconomic conditions since 1970. Infection with HBV may be eliminated there in the near future.     

Shear bond strength of amalgam adhesives to dentin

Recent studies have suggested that failure of pentamidine prophylaxis against Pneumocystis carinii pneumonia (PCP) may be due to reduced deposition of pentamidine in the upper lobes. In this study, we performed bronchoalveolar lavage from the apical segment of the upper lobe and the middle lobe in 51 HIV-positive patients, all of whom were receiving prophylaxis with aerosolized pentamidine, who had presented with acute respiratory symptoms. Lavage fluid from each lobe was assayed for pentamidine using high-performance liquid chromatography (HPLC). The number of clusters of P carinii were counted after staining with a Wright-Giemsa stain. The patients were subclassified as PCP-positive (32 patients) and PCP-negative (19 patients) on the basis of the presence/absence of P carinii clusters in their BAL fluid. The concentration of pentamidine in the upper lobe compared with the middle lobe was no different (using paired Student's t tests) for either PCP-positive patients or PCP-negative patients. In comparing the positive with the negative subjects, using unpaired Student's t test, there was no difference in the concentration of pentamidine in the upper lobe or the middle lobe. For PCP-positive patients, the numbers of P carinii clusters were on average higher in the upper lobes (mean +/- SD: upper = 14.9 +/- 16.6, middle 7.5 +/- 10.8, p = 0.013, paired Student's t test), but there was no correlation between lobar P carinii cluster counts and pentamidine levels. We conclude that the absence of a relationship between cluster count and pentamidine level, the similarity in regional pentamidine levels between upper and middle lobes, as well as the similarity in pentamidine levels between the PCP-positive and PCP-negative groups indicate that the regional dose of pentamidine is not the determining factor as to whether aerosolized pentamidine prophylaxis will succeed or fail.     

Preparation and photoconduction of rapidly quenched films in the Bi2O3-TiO2 system

The rapidly quenched films in the Bi₂O₃-TiO₂ system (0 to 60% TiO₂) were prepared using a twin-roller type apparatus. The films precipitated Bi₂O₃ solid solutions of different types in the composition ranges, with TiO₂ contents of 0 to 5, 7.5 to 10 and 12.5 to 40%, respectively. The first solid solution had a tetragonal structure of -form. The second, though also crystallized in the tetragonal structure, adopted a disordered modification of the -form. The third solid solution was -form (defect fluorite structure). The formation of amorphous phase commenced in the composition with 30% TiO₂, and the films became completely amorphous beyond 50% TiO₂. The quenched films showed a certain instability to decompose or transform into the different phase assemblage by annealing at higher temperatures (about 400 to 500° C, except 260° C for the pure Bi₂O₃ film). The quenched films were also characterized by a high photoconductivity. The photoconduction mechanism was suggested to be associated with a structural imperfection of Bi₂O₃ accompanied by a certain amount of pentavalent bismuth ion.     

MiR-10a in Pancreatic Juice as a Biomarker for Invasive Intraductal Papillary Mucinous Neoplasm by miRNA Sequencing

New biomarkers are needed to further stratify the risk of malignancy in intraductal papillary mucinous neoplasm (IPMN). Although microRNAs (miRNAs) are expected to be stable biomarkers, they can vary owing to a lack of definite internal controls. To identify universal biomarkers for invasive IPMN, we performed miRNA sequencing using tumor-normal paired samples. A total of 19 resected tissues and 13 pancreatic juice samples from 32 IPMN patients were analyzed for miRNA expression by next-generation sequencing with a two-step normalization of miRNA sequence data. The miRNAs involved in IPMN associated with invasive carcinoma were identified from this tissue analysis and further verified with the pancreatic juice samples. From the tumor-normal paired tissue analysis of the expression levels of 2792 miRNAs, 20 upregulated and 17 downregulated miRNAs were identified. In IPMN associated with invasive carcinoma (INV), miR-10a-5p and miR-221-3p were upregulated and miR-148a-3p was downregulated when compared with noninvasive IPMN. When these findings were further validated with pancreatic juice samples, miR-10a-5p was found to be elevated in INV (p = 0.002). Therefore, three differentially expressed miRNAs were identified in tissues with INV, and the expression of miR-10a-5p was also elevated in pancreatic juice samples with INV. MiR-10a-5p is a promising additional biomarker for invasive IPMN.     

Spherical Aluminum Nitride Fillers for Heat-Conducting Plastic Packages

It is necessary for encapsulants to have not only a suitable coefficient of thermal expansion (CTE) compatible to IC devices and a low dielectric constant to reduce the device propagation delay, but also a high thermal conductivity to dissipate large amounts of heat from power-hungry, high-speed IC and high-density packages. Fillers such as silica have been mixed with polymers to improve their properties. Aluminum nitride (AlN) is considered as an alternative one, because it has a higher theoretical thermal conductivity of ∼320 W/mK¹, a compatible CTE with silicon chips and a low dielectric constant. Commercial AlN fillers are angular in shape, because they are prepared via grinding coarse AlN powders synthesized by direct nitridation of aluminum metal and classification. The angular AlN are not expected to have high fluidity when mixed with polymers and hence low packing density. Recently, we successfully obtained single-crystalline spherical AlN fillers. Furthermore, polymer composites filled with the spherical AlN showed excellent thermal conductivity (>8 W/mK) as encapsulants for dissipating the heat generated in electronic devices.     

Formation and transformation of cubic 3PbO·2Ta2O5 solid solution

The formation of lead tantalates in the PbO-rich region is studied using the powders prepared by the simultaneous hydrolysis of lead and tantalum alkoxides. Cubic 3PbO · 2Ta₂O₅ solid solutions crystallize at low temperatures from amorphous materials between 60 and 75 mol% PbO. The lattice parameter,a, increases linearly from 1.0545 to 1.0705 nm with increasing PbO. At higher temperatures the solid solutions above 66.67 mol% PbO are transformed into those of rhombohedral 2PbO · Ta₂O₅. Rhombohedral 5PbO · 2Ta₂O₅ is formed at 850 to 900 °C by transformation of 2PbO·Ta₂O₅ solid solution corresponding to 71.43 mol% PbO. The existence of previously reported 3PbO·Ta₂O₅ is not confirmed.     

Measurement of self-diffusion coefficients in Li ionic conductors by using the short-lived radiotracer of 8Li

For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of ⁸Li (T_1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing ⁸Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li).     

A content search system considering the activity and context of a mobile user

People routinely carry mobile devices in their daily lives and obtain a variety of information from the Internet in many different situations. In searching for information (content) with a mobile device, a user’s activity (e.g., moving or stationary) and context (e.g., commuting in the morning or going downtown in the evening) often change, and such changes can affect the user’s degree of concentration on his or her mobile device’s display and information needs. Therefore, a search system should provide the user with an amount of information suitable for the current activity and a type of information suitable for the current context. In this study, we present the design and implementation of a content search system that considers a mobile user’s activity and context, with the goal of reducing the user’s operation load for content search. The proposed system switches between two kinds of content search systems according to the user’s activity: the location-based content search system is activated when the user is stationary (e.g., standing and sitting), while a menu-based content search system is activated when the user is moving (e.g., walking). Both systems present information according to user context. The location-based system presents detailed information via menus and a map according to location-based categories. The menu-based system presents only a few options to enable users to get content easily. Through user experiments, we confirmed that participants could get desired information more easily with this system than with a commercial search system.     

Scattering mechanism and reduction of insertion losses in a laminated polarization splitter

We experimentally found the unexpected phenomena of scattering in laminated polarization splitters (LPS's) composed of a-Si:H-SiO(2) multilayer and studied its mechanism. The scattering phenomena strongly depend on the incident angle and polarization of the incident light. To reduce the scattering loss in LPS's, a multilayer with flat layer boundaries is fabricated with rf bias sputtering. As a result, the insertion loss of the LPS is reduced to ~ 1 × 10(-3) dB/ μm, which is acceptable for practical uses.     

Probabilistic nearest neighbor query processing on distributed uncertain data

A nearest neighbor (NN) query, which returns the most similar object to a user-specified query object, plays an important role in a wide range of applications and hence has received considerable attention. In many such applications, e.g., sensor data collection and location-based services, objects are inherently uncertain. Furthermore, due to the ever increasing generation of massive datasets, the importance of distributed databases, which deal with such data objects, has been growing. One emerging challenge is to efficiently process probabilistic NN queries over distributed uncertain databases. The straightforward approach, that each local site forwards its own database to the central server, is communication-expensive, so we have to minimize communication cost for the NN object retrieval. In this paper, we focus on two important queries, namely top-k probable NN queries and probabilistic star queries, and propose efficient algorithms to process them over distributed uncertain databases. Extensive experiments on both real and synthetic data have demonstrated that our algorithms significantly reduce communication cost.