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This study examines the relationship between paternal height or body mass index (BMI) and birth weight of their offspring in a Japanese general population. The sample included 33,448 pregnant Japanese women and used fixed data, including maternal, paternal and infant characteristics, from the Japan Environment and Children’s Study (JECS), an ongoing nationwide birth cohort study. Relationships between paternal height or BMI and infant birth weight [i.e., small for gestational age (SGA) and large for gestational age (LGA)] were examined using a multinomial logistic regression model. Since fetal programming may be a sex-specific process, male and female infants were analyzed separately. Multivariate analysis showed that the higher the paternal height, the higher the odds of LGA and the lower the odds of SGA in both male and female infants. The effects of paternal BMI on the odds of both SGA and LGA in male infants were similar to those of paternal height; however, paternal height had a stronger impact than BMI on the odds of male LGA. In addition, paternal BMI showed no association with the odds of SGA and only a weak association with the odds of LGA in female infants. This cohort study showed that paternal height was associated with birth weight of their offspring and had stronger effects than paternal BMI, suggesting that the impact of paternal height on infant birth weight could be explained by genetic factors. The sex-dependent effect of paternal BMI on infant birth weight may be due to epigenetic effects.
Diarrhoeagenic Escherichia coli (DEC) is a leading cause of infectious diarrhoea worldwide. In recent years, Escherichia albertii has also been implicated as a cause of human enteric diseases. This study describes the occurrence of E. coli pathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC). PCR of stool enrichments for DEC pathotypes was employed, and E. albertii was also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10 E. albertii strains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. Two E. albertii isolates belonged to serogroup O113 and one had the stx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report of E. albertii isolation from active surveillance. These results highlight the need of continuing DEC and E. albertii surveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.
This study aimed to predict eosinophilic chronic rhinosinusitis prognosis by investigating changes in the blood eosinophil count and other disease biomarkers after surgery.
Blood eosinophil numbers and serum interleukin-5 levels were measured in 22 eosinophilic chronic rhinosinusitis patients before and after functional endoscopic sinus surgery, and compared with equivalent measures in non-eosinophilic chronic rhinosinusitis patients and chronic rhinosinusitis without polyps patients. Differences between well-controlled eosinophilic chronic rhinosinusitis patients and those who experienced recurrence were also assessed.
Blood eosinophil numbers and serum interleukin-5 level decreased after surgery in eosinophilic chronic rhinosinusitis patients. In this patient group, blood eosinophil counts before surgery were significantly higher in patients who experienced recurrence (825.7 ± 26.1 vs 443.9 ± 76.6 cells/μl, p < 0.05), and decreased significantly after surgery (825.7 ± 26.1 vs 76.7 ± 25.8 cells/μl, p < 0.05).
Blood eosinophil numbers may reflect disease severity in eosinophilic chronic rhinosinusitis patients and their prognosis after surgery.
Population genetics of invading pests can be informative for understanding their ecology. In this study, we investigated population genetics of the invasive alfalfa weevil Hypera postica in Fukuoka Prefecture, Japan. We analyzed mitochondrial tRNALeu-COII, nuclear EF-1α gene fragments, and Wolbachia infection in relation to three leguminous host plants: Vicia angustifolia, Vicia villosa, and a new host Astragalus sinicus cultivated as a honey source and green manure crop. A parsimony network generated from mitochondrial gene sequences uncovered two major haplotypic groups, Western and Egyptian. In contrast to reported Wolbachia infection of the Western strain in the United States, none of our analyzed individuals were infected. The absence of Wolbachia may contribute to the stable coexistence of mitochondrial strains through inter-strain reproductive compatibility. Hypera postica genetic variants for the mitochondrial and nuclear genes were associated neither with host plant species nor with two geographic regions (Hisayama and Kama) within Fukuoka. Mitochondrial haplogroups were incongruent with nuclear genetic variants. Genetic diversity at the nuclear locus was the highest for the populations feeding on V. angustifolia. The nuclear data for A. sinicus-feeding populations indicated past sudden population growth and extended Bayesian skyline plot analysis based on the mitochondrial and nuclear data showed that the growth of A. sinicus-feeding population took place within the past 1000 years. These results suggest a shorter history of A. sinicus as a host plant compared with V. angustifolia and a recent rapid growth of H. postica population using the new host A. sinicus.
Various nanostructures with high-aspect-ratio formed in a low-resistivity silicon wafer by the nano-processing using a carbon nanotube (CNT) probe of a scanning tunneling microscope (STM) have been investigated. The multi-wall CNT probes were obtained with our original pulling-method from CNT dispersion liquid. Nanostructures of point configurations (pit and mound) and line configurations were obtained at the constant tunneling current of 0.1 nA by controlling the bias voltages up to 10 V, processing times up to 300 s and scanning speeds of probe up to 480 nm/s for a line configuration. The aspect-ratio of the pit configuration fabricated at the bias voltage of 3 V increased about 6 times in proportion to the increase in processing time. Remarkable influence of the bias voltage on the configurations indicated that there exists a threshold bias voltage for the transition from the pit configuration to the mound one between 3 V and 5 V, and the aspect ratio of all nanostructures fabricated by the CNT probe were larger than those by a conventional tungsten probe. Finally, cross-sectional TEM observations were also applied to clarify the difference in the formation mechanisms between the pit configuration and the mound configuration. The TEM image of the pit configuration showed neither dislocations nor remarkable strains existed, but in the case of the mound shape TEM analysis indicated the existence of single crystalline silicon region solidified with atomic defects under the mound configuration. Therefore the drastic change of the configurations was attributed to the changes of the atomic-scale microstructures by applying the bias voltages.
Mucosal mast cells (MMC) play a crucial role in the expulsion of Strongyloides ratti adults from the small intestine of mice. We reported the large intestinal parasitism of S. ratti in rats, and there has been no report on MMC in the large intestine of the natural host. We studied kinetics of MMC, together with eosinophils, in the upper and lower small intestines, caecum and colon of infected rats. Two distinct phases of mastocytosis were revealed: one in the upper small intestine triggered by stimulation of ‘ordinary’ adults, and the other in the colon stimulated by ‘immune-resistant’ adults that started parasitizing the colon around 19 days post-infection. In all 4 intestinal sites, the MMC peaks were observed 5–7 days after the number of adult worms became the maximum and the height of MMC peaks appeared to be dependent on the number of parasitic adults, suggesting an important role played by worms themselves in the MMC buildup.
The heterogeneous integration of III-V semiconductors with the Si platform is expected to provide high performance CMOS logic for future technology nodes because of high electron mobility and low electron effective mass in III-V semiconductors. However, there are many technology issues to be addressed for integrating III-V MOSFETs on the Si platform as follow; high-quality MOS interface formation, low resistivity source/drain formation, and high-quality III-V film formation on Si substrates. In this paper, we present several possible solutions for the above critical issues of III-V MOSFETs on the Si platform. In addition, we present the III-V CMOS photonics platform on which III-V MOSFETs and III-V photonics can be monolithically integrated for ultra-large scale electric-optic integrated circuits.
Strongyloides ratti (Nagoya strain) is unique in that a portion of adults parasitizing the small intestine withstands ‘worm expulsion’, which starts at around day 8 post-infection (p.i.) by host immunity, and establishes in the large intestine after day 19 p.i. To investigate the mechanism, adults obtained from the small intestine at day 7 or 19 p.i. were transplanted into the colon of infection-primed immune rats. Adults obtained at day 7 p.i. were rejected quickly, whereas those obtained at day 19 p.i. could establish infection. Moreover, the body length and the number of intrauterine eggs increased in the large intestine. In a separate experiment, large intestinal parasitism was abolished by the treatment of host rats with an anti-oxidant, butylated hydroxyanisole. These results indicate that small intestinal adults between days 7 and 19 p.i. acquired the ability to parasitize the large intestine of immune rats, and that free radicals produced by the host may have played a significant role in the process.
A new fabrication method of SiGe-on-Insulator (SGOI) and Ge-on-Insulator (GOI) structures are presented as well as the application to high-mobility channel CMOS devices. This method, the Ge-condensation technique, consists of epitaxial growth of a SiGe layer with a low Ge fraction on an SOI substrate and successive oxidation at high temperatures, which can be incorporated in conventional CMOS processes. During the oxidation, Ge atoms are pushed out from the oxide layer and condensed in the remaining SiGe layer. The interface between the Si and SiGe layers is disappeared due to the interdiffusion of Si and Ge atoms. Eventually, an SGOI layer with a higher Ge fraction is formed on the buried oxide layer. The Ge fraction in the SGOI layer can be controlled by the oxidation time because total amount of Ge atoms in the SGOI layer is conserved throughout the oxidation process. We found that the lattice relaxation in the SGOI layer also can be controlled through the initial SiGe thickness. P- and n-type strained SOI MOSFETs, which were fabricated on relaxed SGOI substrates formed by this technique, exhibited mobility enhancement of 50% and 80%, respectively. CMOS ring oscillators comprised of the MOSFETs exhibited reduction in propagation delay of 70%-30% compared to a conventional SOI-CMOS device. Ultrathin-body strained SGOI pMOSFETs with high Ge fraction and surface channels were also fabricated by this technique. These devices exhibited hole-mobility enhancement factors up to 2.3. Furthermore, Ge-on-Insulator (GOI) structures with thicknesses less than 10 nm were realized for ultrathin body GOI-CMOS applications by using the Ge-condensation technique. In conclusion, the Ge-condensation technique is a promising technique for fabricating various types of high-mobility channel-on-insulator devices.
Strained-Si MOSFET is an attractive device structure to be able to relax several fundamental limitations of CMOS scaling, because of high electron and hole mobility and compatibility with Si CMOS standard processing. In this paper, we present a new device structure including strained-Si channel, strained-SOI MOSFET, applicable to CMOS under sub-100 nm technology nodes. The main feature of this device is that thin strained-Si channel/relaxed SiGe hetero-structures are formed on buried oxides. The principle and the advantages are described in detail. The strained-SOI MOSFETs, whose electron and hole mobility is 1.6 and 1.3 times, respectively, higher than in conventional MOSFETs, have successfully been fabricated by combining the SIMOX technology with re-growth of strained Si films. We also present novel fabrication techniques to realize ultra-thin SiGe-on-Insulator (SGOI) virtual substrates with high Ge content, including Ge condensation due to oxidation of SGOI with lower Ge content. Strained-Si/SGOI structures with total thickness of 21 nm and Ge content of 56 % have been fabricated by oxidizing SiGe films on conventional SOI substrates and re-growing strained-Si films.
W(15 Å)/C(15 Å), W(50 Å)/C(50 Å) and W(100 Å)/C(100 Å) periodic multilaver films were prepared by magnetron sputtering and suhsequently annealed at 980, 730 and 500°C. The changes of layered and crystal structures were studied by x-ray diffraction. The results depended largely on the thickness of W layers and their initial crystal struictures of W. The kinds of transformations are classified into two types: one is the non-reacting type in the case of multilayers having the thinner W layers like W(15 Å)/C(15 Å), in which the crystallization of W layers prevails over the reactions between W and C layers; the other, the reacting type in the multilayers having thicker W layers like W(50 Å)/C(50 Å) and W(100 Å)/C(100 Å), in which reactions Prevail over crystallization. A tentative model in which the effective reaction rate between amorphous–W and amornhous–C is much smaller than that of crystalline-W(beta phase) and amorphous-C is proposed to explain the origin of the phenomena.
YBa2Cu3O7-δ single crystals and epitaxial films are grown and characterized. In flux growth for bulk crystals, effects of growth conditions on yield and electric resistivity of crystals are examined. The yield of flaky crystals depends on the formation of cavities. The transition temperature is 86 K after annealing in an oxygen atmosphere. Films are prepared on SrTiO3 by sputtering and epitaxial growth is confirmed by high resolution electron microscopy. Periodic lattice defects are observed near the interface between the substrate and the film. It seems that these defects result from the diffusion of impurities from the substrate.
The addition of nitrous oxide (N2O) gas in the hot-filament chemical vapor deposition of carbon film from mixtures of methane and hydrogen was found to increase remarkably the content of diamond structure in the film. Increased particle size and crystal orientation parallel to the (111) direction were also obtained by the N2O addition. Mass spectrometry revealed that the vapor phase reaction was scarcely affected by the N2O addition.
The crystal growth, characterization and various characteristics such as electrical, thermal and semiconducting properties of boron phosphide (BP) single crystalline wafers made by chemical vapor deposition technique are summrized. It is demonstrated that Schottky diode using single crystal and thermoelectric device employing sintered polycrystal are promising application for electronic materials.
All-oxide S-N-S (superconductor-normal layer-superconductor) junctions having a planar structure are fabricated and their electrical characteristics in the normal state are investigated. The superconducting electrodes are composed of HoBa2Cu3O7−x, and the normal layer is La1.5Ba1.5Cu3O7-y. Conductance characteristics are measured and their behaviors are explained by the geometrical resonance of quasiparticles. A pair potential distribution in the normal layer is estimated from the resonance structure.
A low temperature preheating process is developed for metalorganic chemical vapor deposition (MOCVD) growth of GaAs on wet chemical pretreated Si substrates. NH4 OH/H2 O2 is found to be most effective in decreasing the preheating temperature among the chemicals we tried: NH4 OH/H2 O2, H2SO4 /H2O2, or hot HNO3. By using NH4OH/H2 O2, the preheating temperature is reduced from 1000°C to 875°C. X-ray diffraction measurements and surface observations with an atomic force microscope (AFM) show that the GaAs film quality obtained with the 875 °C preheating process is better than that obtained with 1000°C preheating.
We developed GaAs heteroepitaxy on a Si substrate by metalorganio vapor phase epitaxy (MOVPE) using tertiarybutylarsine (TBAs). When we preheated Si at 1000ºC in the atmosphere including TBAs, a carbide layer was formed on the Si surface. This led to polycrystalline GaAs growth. By carrying out high-temperature preheating in an H2 -only atmosphere and supplying TBAs after the preheating, we have successfully grown single-crystal GaAs with a mirror surface in a process completely free of AsH3.
We developed GaAs heteroepitaxy on a Si substrate by metalorganic vapor phase epitaxy (MOVPE) using tertiarybutylarsine (TBAs). In buffer layer growth at 450°C, the surface morphology and crystal quality of TBAs-grown films were slightly inferior to those of AsH3-grown films. At buffer layer growth below 400°C, the quality of TBAs-grown films improved. The GaAs films we grew using TBAs had a better quality than those grown using AsH2.
We have discovered 24 K-superconductivity in a family of compounds Ln2−xCexCuO4−y (Ln=Pr, Nd, Sm). Novel feature of the superconductivity in these family of compounds is that superconductivity is produced by electron-doping in sharp contrast with high-Tc cuprates discovered so far. The effect of doping on physical properties particularly the elecronic phase diagram and transport coefficients which indicate symmetry in many respects between electron- and hole- doping is described.