This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118–1.218) for PTD, 1.174 (95% CI: 1.070–1.287) for early PTD and 1.151 (95% CI: 1.098–1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

This study aimed to evaluate the association between parental and infant birth weights in Japan. In total, 37,504 pregnant Japanese women and their partners were included in this birth cohort study. A multinomial logistic regression model was used to evaluate the associations of parental birth weights with small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infants. Associations between parental birth weight and low birth weight (LBW) infants or macrosomia were also examined, and linear associations between parental birth weight and SGA or LGA were found. The adjusted odds ratios (aORs) for SGA infants per 500 g decrease in maternal and paternal birth weights were 1.50 (95% confidence interval [CI],1.43–1.58) and 1.31 (95% CI, 1.25–1.38), respectively. The aORs for LGA infants per 500 g increase in maternal and paternal birth weights were 1.53 (95% CI, 1.47–1.60) and 1.41 (95% CI, 1.35–1.47), respectively. The association between parental birth weight and LBW infants or macrosomia was also linear. The aORs for LBW infants per 500 g decrease in maternal and paternal birth weights were 1.47 (95% CI, 1.40–1.55) and 1.25 (95% CI, 1.19–1.31), respectively. The aORs for macrosomia per 500 g increase in maternal and paternal birth weights were 1.59 (95% CI, 1.41–1.79) and 1.40 (95% CI, 1.23–1.60), respectively. Parental birth weight was found to be associated with infant birth weight even after adjusting for various parental factors. Furthermore, maternal birth weight was more strongly associated with infant birth weight than with paternal birth weight.

Sagamiscintilla thalassemicola (Bivalvia: Galeommatoidea: Galeommatidae) is a rare ectocommensal bivalve that lives on the proboscis of echiuran worms, Anelassorhynchus spp. (Annelida: Thalassematidae: Thalassematinae: Thalassematini), and has been known only from the temperate zones of Japan. In this study, we found S. thalassemicola on the proboscis of the large echiuran Ochetostoma sp. (Thalassematidae: Thalassematinae: Thalassematini) on intertidal flats of three islands of the Ryukyu Archipelago, southern Japan. These are the first records of S. thalassemicola on non-Anelassorhynchus hosts and also from the subtropical regions. Additionally, we also collected S. thalassemicola from an intertidal flat of Kushimoto, Wakayama, Kii Peninsula, Japan, which is an update of the easternmost record of this species. The genetic differences in the mitochondrial cytochrome c oxidase subunit I and nuclear internal transcribed spacer 2 genes among S. thalassemicola, including those with Ochetostoma sp. from the subtropical region and with Anelassorhynchus spp. from the temperate region, can be considered within the intraspecific variation. These suggest that S. thalassemicola uses different echiuran hosts in the temperate and subtropical regions, respectively.

Single photon sources (SPS) are an important building block for realizing quantum technologies for computing, communication, and sensing. For industrialization, electrically controllable color centers acting as SPS are required. We have demonstrated the creation of electrically controllable silicon vacancies (VSis) in the SiC pn junction diode fabricated by proton beam writing (PBW). PBW was successfully used to introduce electrically controllable VSi without degradation of the diode performance. The dependence of the electroluminescence (EL) and photoluminescence (PL) intensities from VSi on H+ fluence revealed that the emission efficiency of EL is less than that of PL. For EL, the supply of carriers (electrons and/or holes) was restricted due to the resistive region around each VSi introduced by PBW. The results suggest that further improvement in the VSi creation process without defects acting as majority carrier removal centers (highly resistive region) and nonradiative centers by optimization of PBW conditions are key points to realize highly sensitive quantum sensors using VSi.

Development of an iodine immobilization technique that can fix radioactive iodine in waste form for a long period and constrain its leaching into pore water is necessary in order to secure the long-term safety of geological disposal of transuranic (TRU) waste.

Lead borate glass vitrified at a low temperature is regarded as one of the promising immobilization materials of Iodine-129 which will be removed from spent AgI filters generated from reprocessing plants and may have a significant effect on long term safety of geological disposal.

Leaching experiments in bentonite-equilibrium water have been conducted to understand the lead borate glass dissolution behaviors in possible geological disposal conditions. Boron dissolved with the highest rate in all types of the solutions and was regarded as an index element to represent the glass dissolution rate. On the other hand, lead dissolved with a far slower rate. The chemical species and possible precipitating minerals of lead were examined by a geochemical calculation code for typical underground water. Altered glass surfaces were investigated by SEM, TEM and XRD. XRD analysis showed that the main constituent phase of the altered layer was hydrocerussite, Pb3(CO3)2(OH)2, that was predicted by the geochemical simulation as well.

We present a bottom-up fabrication route to fabricate solid-solution Rh–Pd–Pt ternary alloy nanoparticles (NPs), with well-controlled compositions through femtosecond laser irradiation of a mixed solution of metallic ions, without any reducing agents and complicated processes. The structure of fabricated NPs was crystalline, and formation of solid-solution alloy formation was confirmed by electron and x-ray diffraction measurements. The crystalline nature of alloy NPs was also confirmed through high-resolution transmission electron microscope measurement. According to energy dispersive spectroscopy analysis, elemental composition of an individual NP was almost the same as the initial feeding ratio of ions in the mixed solutions. The electronic state of the element in alloy NPs was confirmed to be pure metal by XPS measurement. The structural studies of Rh–Pd–Pt NPs suggested that the demonstrated technique opens up a new dimension for the fabrication of NPs, which has well-controlled properties for practical use in various fields.

A novel and fundamental method was reported to judge states of lithium ion batteries (LIBs) using the capacitance and the voltage of the cells that were estimated from the real-time currents and voltage characteristics of the cells. We measured the differential capacitance, that is, dQ/dV or delta Q/ delta V that is equal to the currents (I) divided by differential voltages (dV/dt) calculated from the current and the voltage characteristics of the cell during the charging/ discharging, where Q is the charge that flows through the cell, V is the voltage of the cell and t is time. It is thought that the capacitance decrease with the degradation of the cell because the effective area of the electrodes is decreasing due to formation of undesirable compounds. The differential capacitance in some specific voltage range for the LIBs was approximately directly proportional to the state of the degradation of the cell. Therefore, it is concluded that the novel method is very useful to judge the state of the LIBs.

Many industries have developed new materials as substitutes for lead in solid lubricants. For example, lead bronze, a Cu-Pb alloy that has been used for slide bearings, has been replaced by a Cu alloy containing sulfide. The development of Pb-free Cu alloys has received considerable attention recently. Pb and sulfide are types of solid lubricants; in particular, MoS2 (molybdenum disulfide) is a popular sulfide lubricant. This study focuses on a material that contains Cu2S. The properties of Cu2S as a solid lubricant are unknown. First principles (FP) and molecular dynamics (MD) are used to clarify the lubrication mechanism of Cu2S. The atomiclevel stable structure of Cu2S is evaluated by FP under specific sliding conditions. The Cu2S lubrication mechanism is clarified by MD using the FP results for the interatomic potential functions. It is clarified that there is a specific slip system and the Cu-S bonds that exists above and below the layers of the slip system are very strong.

This study was conducted to review the overall short-term outcome of monoamniotic twins in Japan and to determine the prospective risk of fetal death so as to adequately counsel parents with monoamniotic twins. Study subjects were 101 women with monoamniotic twins who were registered with the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System and who had given birth at ≥22 weeks of gestation during 2002–2009. The gestational week at delivery (mean ± SD) was 31.8 ± 3.7. Fourteen women experienced intrauterine fetal death (IUFD). Short-term outcomes of co-twins born to the 14 women included 8 IUFDs, one early neonatal death within 7 days of life (END), and 5 survivors. Four other women experienced 5 ENDs. Thus, 13.9% (28/202) of infants died perinatally (22 IUFDs and 6 ENDs), 13.9% (14/101) of women experienced IUFD, and 82.2% (83/101) of women experienced neither IUFD nor END. Structural anomalies and twin-to-twin transfusion syndrome explained 17.9% (five infants) and 10.7% (three infants) of the 28 perinatal deaths, respectively. The prospective risk of IUFD was 13.9% (14/101) for women who reached gestational week 22−0/7, gradually decreasing thereafter but remaining at between 4.5% and 8.0% between gestational week 30−0/7 and 36−0/7.

Aluminum oxide (Al2Ox) buffer layers were employed to grow single-walled carbon nanotubes (SWNTs) at 400°C using an alcohol gas source and a Co catalyst. By optimizing the thickness of the aluminum oxide layer, the SWNT yield was enhanced by a factor of several times. In addition, SWNT growth at 350°C was realized on the Al2Ox buffer layer by this method. Raman measurements at various excitation wavelengths suggest that a Al2Ox buffer layer preferentially enhances the growth of SWNTs with larger diameters (>1 nm).

In order to restrain global warming and to realize a sustainable global energy system, further enhancements in energy efficiency are required. One reliable technology for reducing greenhouse gas emissions and the consumption of fossil fuel is thermoelectric technology, which can directly convert heat into electricity and consequently increases the energy conversion efficiency of power generation by combustion. Magnesium silicide (Mg2Si) is a promising candidate for a thermal-to-electric energy-conversion material at operating temperatures ranging from 500 to 800 K. Mg2Si exhibits many promising characteristics, such as the abundance of its constituent elements in the earth’s crust and the non-toxicity of its processing by-products, resulting in freedom from concerns regarding prospective extended restrictions on hazardous substances. The efficiency of a thermoelectric device is characterized by the dimensionless figure of merit, ZT. It is well known that several kinds of dopants are effective in improving the thermoelectric performance of n-type Mg2Si. With Bi-doped n-type Mg2Si, we have achieved a maximum value of the dimensionless figure-of-merit ZT of ˜1.0 at ˜ 850 K. However, the correlation between the ZT values and the power generation characteristics, which is essential to understand in order to design a structure for a TE power generation module, has not been sufficiently investigated. In order to design a structure for a thermoelectric module using Mg2Si, we examined the correlation between the ZT values and the power-output of a single element using Mg2Si (ZT = 0.6) and Mg2Si doped with donor impurities such as Al and/or Bi (ZT = 0.65˜0.77). The measured single element was 2×2 mm2 in section and 10 mm long. Additionally, we developed and evaluated a new architecture based on a ‘unileg’ structure Mg2Si TE power generation module, which can improve the module lifetime and simplify its manufacture. As a starting material for the fabrication of the single element and the TE modules, pre-synthesized polycrystalline Mg2Si, fabricated by UNION MATERIAL was used. The material was sintered using a plasma-activated sintering (PAS) technique, and, at the same time, Ni electrodes were formed on the Mg2Si by employing of a monobloc PAS technique. The thermoelectric power-outputs were measured under a temperature difference, ΔT, ranging from 100-to-500 K by using UNION MATERIAL UMTE-1000M. The observed power-output for single element of Mg2Si (ZT = 0.6), 2 at % Bi-doped Mg2Si (ZT = 0.65) and 1at % Bi + 1at % Al-doped Mg2Si (ZT = 0.77) were 23.2 mW, 13.6 mW and 19.4 mW respectively at ΔT = 500 K (between 873 K and 373 K). For the new architecture based on the unileg structure thermoelectric module, the observed value for power-output-per-unit-area was 12 mW/mm2 at ΔT = 500 K.

Gold particles were fabricated by the high-intensity femtosecond laser irradiation of gold (III) chloride trihydrate (HAuCl4) aqueous solution. The structure and size distribution of the prepared particles were evaluated by transmission electron microscopy. The configuration of the gold particles varied with the concentration of the HAuCl4 aqueous solution. The mean particle size and size distribution were changed by the addition of polyvinylpyrrolidone (PVP), which acted as a dispersant, and monodispersed gold nanoparticles with a diameter of about 3 nm were successfully fabricated. The formation process of the nanoparticles is discussed in terms of the optical decomposition of molecules in the highly intense optical field generated by femtosecond laser irradiation.

We observed the enhancement of fluorescence intensity due to the addition of GeO2 in bismuth-doped silica glass (BiSG), which has a peculiar fluorescence at 1.25 μm with a full width at half-maximum of 300 nm. Experimental results revealed that the fluorescence intensity from BiSG with 5.0 mol% GeO2 increased remarkably to be 26.3 times greater than that without GeO2 additive for the same Bi2O3 concentration (0.1 mol%). Furthermore, the enhanced sample showed almost the same intensity as BiSG without GeO2 for 1.0 mol% Bi2O3. These results demonstrate that GeO2 additive effectively promotes the generation of peculiar luminescent centers.