Synthesis of glutamate by reductive amination of 2-oxoglutarate with the combination of hydrogenase and glutamate dehydrogenase

Glutamate synthesis by reductive amination of 2-oxoglutarate was performed by the combination of NADH regeneration system and glutamate dehydrogenase (GluDH). The conversion of 2-oxoglutamate to glutamate was 98% after 3 h, and the turnover number of NAD⁺was 17.     

Low-threshold strained multi-quantum well lasers fabricated by selective metalorganic vapor phase epitaxy without a semiconductor etching process

Strained InGaAsP multi-quantum well (MQW) buried hetero- (BH) laser diodes (LDs) on a p-InP substrate were fabricated by selective metalorganic vapor phase epitaxy (MOVPE). In the laser fabrication process, both the strained MQW active layer and current blocking structure were directly formed by selective MOVPE without a semiconductor etching process. This novel laser fabrication process produces extremely uniform device characteristics that are essential to the deployment of optical subscriber systems. Furthermore, important device design parameters (e.g. the active stripe shape or the leakage current path configuration) are precisely controlled by only the epitaxial growth steps. This highly controllable laser fabrication method results in a very low-threshold current with excellent uniformity (I_th = 1.78 ± 0.19 mA) for 20 consecutive LDs (L = 200 μm with 70%–90% coatings).     

Study of neonatal exposure to androgenic endocrine disruptors, testosterone and dihydrotestosterone by normal-phase HPLC

Neonatal exposure to androgen induces developmental abnormalities in the male reproductive system. To investigate whether neonatal exposure affects spermatogenesis in juvenile and pubertal testis, Sprague-Dawley rat pups were given androgen or various androgenic endocrine disruptors by a single injection on the day of birth at concentrations ranging between 4 mm to 200 mm, and sacrificed on day 21 (juvenile) or 50 (puberty). The testes were weighed and examined histologically at each stage. Further, the metabolites of steroidogenesis were analyzed using normal-phase high-performance liquid chromatography. Neonatal exposure significantly reduced testis weights and steroidogenesis of juveniles. Neonatal exposure to testosterone and dihydrotestosterone still suppressed pubertal steroidogenesis, although testis weight was completely restored during puberty.     

Isolation of (E)-9,10-dihydroxy-2-decenoic acid from royal jelly and determination of the absolute configuration by chemical synthesis

(E)-9,10-Dihydroxy-2-decenoic acid 1 was isolated as a new compound from royal jelly. The planar structure was deduced by spectroscopic analyses, whereas the absolute configuration was established by chemical synthesis of both enantiomers of 1. The natural product was revealed to be ca. 3.5:1 mixture of (R)- and (S)-acids by comparison of 1 with authentic samples.     

Investigation of conductivity of adhesive layer including indium tin oxide particles for multi-junction solar cells

We report connection conductivity ( \(C_{\rm c}\) ) of adhesive which including \(\hbox {In}_2\hbox {O}_3\) – \(\hbox {SnO}_2\) (ITO) particles developed for fabrication of stacked-type-multi-junction solar cells. The commercial 20- \(\upmu \) m sized ITO particles were heated in vacuum at temperature ranging from 800 to 1,300  \(^{\circ }{\rm C}\) for 10 min to increase \(C_{\rm c}\) . 6.2 wt% ITO particles were dispersed in commercial Cemedine adhesive gel to form 100 samples structured with n-type Si/adhesive/n-type Si (n-Si sample) and p-type Si/adhesive/p-type Si (p-Si sample). Current density as a function of voltage (J–V) characteristics gave \(C_{\rm c}\) . It ranged from 4.3 to 1.0 S/cm \(^2\) for the n-Si sample with 800 \(^{\circ }{\rm C}\) heat-treated ITO particles. Its standard deviation was 0.59 S/cm \(^2\) . On the other hand, it ranged from 2.0 to 0.6 S/cm \(^2\) for the p-Si sample with 800  \(^{\circ }{\rm C}\) heat-treated ITO particles. Its standard deviation was 0.22 S/cm \(^2\) . The distribution of \(C_{\rm c}\) mainly resulted from contact efficiency of ITO particles to substrate. We theoretically estimated that present \(C_{\rm c}\) achieved a low loss of the power conversion efficiency ( \(E_{\rm ff}\) ) lower than 0.3 % in the application of fabrication of multi-junction solar cell with an intrinsic \(E_{\rm ff}\) of 30 % and an open circuit voltage above 1.9 V.     

Transition on the relationship between fractal dimension and Hurst exponent in the long-range connective sandpile models

The relationships between the Hurst exponent H and the power-law scaling exponent B in a new modification of sandpile models, i.e. the long-range connective sandpile (LRCS) models, exhibit a strong dependence upon the system size L. As L decreases, the LRCS model can demonstrate a transition from the negative to positive correlations between H- and B-values. While the negative and null correlations are associated with the fractional Gaussian noise and generalized Cauchy processes, respectively, the regime with the positive correlation between the Hurst and power-law scaling exponents may suggest an unknown, interesting class of the stochastic processes.