A Method for Received Waveform Reconstruction Based on Bender Element Test Using Frequency-swept Signal

An experimental technique for reconstructing the received wave of bender element tests based on linear system theory is shown in this paper. In order to identify the frequency response of testing apparatus, bender element tests using frequency-swept signals are performed. Received waves for one-period sine pulse transmitting with various frequencies are calculated and compared with observed waves in several kinds of soil samples and testing apparatuses. The linearity of the testing system is also confirmed by coherence function. It is shown that calculated data are less affected by random noise and show good agreement with observed data in regards to not only waveform itself but also resulting shear wave velocity. It is mentioned that this technique can provide simulations for arbitrary transmitted waveform with high signal/noise ratio after laboratory tests are performed. It is also mentioned that this technique is advantageous when sufficient amplitude of received wave cannot be ensured or shear wave velocity must be verified, for example, due to uncertainty of arrival time by near-field effect.     

Dose and dose-rate dependence of mutation frequency under long-term exposure – a new look at DDREF from WAM model

We have investigated the dependence of the mutation frequency on the dose and dose rate of artificial radiation using the Whack-A-Mole (WAM) model that we recently proposed. In particular, we pay special attention to the case of long-term and low-dose-rate exposure. Our results indicate that the WAM model successfully describes the dose-rate dependence, and it can replace the so-called dose and dose-rate effectiveness factor (DDREF), which has been used for long, to account for the differences between high-dose-rate and low-dose-rate data. The basic properties of the WAM model are discussed with special emphasis on the dose-rate dependence in order to demonstrate how the dose-rate dependence, which is built into the model explicitly, plays a key role. Biological effects of long-term exposure to extremely low-dose-rate radiation are discussed in light of analysis of mega-mouse experiments using the WAM model. In the WAM model, the effects of long-term exposure show a saturation property, thus making it distinctly different from the ‘linear no threshold (LNT)’ hypothesis that predicts a linear increase of the effects with time.     

Culture characteristics of carotenoid-producing filamentous fungus T-1, and carotenoid production

The culture characteristics, carotenoid production, and associated biosynthetic pathway of strain T-1 were examined. As a result of examining the culture temperature and light irradiation, an increase of neurosporaxanthin and neurosporaxanthin beta-D-glucopyranoside was observed at a low temperature and 0 lx. It was suggested that highly polar carotenoids, such as neurosporaxanthin, and carotenoid glycosides were involved in the stabilization of membrane during nutrition storage other than the defense function of fungus bodies. Strain T-1 produced lycopene, beta-carotene, gamma-carotene, torulene, neurosporaxanthin, and neurosporaxanthin beta-D-glucopyranoside, as assessed by HPLC, LC-MS, and NMR analysis. Carotenoid biosynthesis begins with neurosporene, passing to lycopene and gamma-carotene through cyclization, and produces beta-carotene. In addition, it is saturated, gamma-carotene is converted to torulene, and neurosporaxanthin is produced. Thus, the carotenoid biosynthetic pathway in strain T-1 was estimated.     

Serum concentration of 20K human growth hormone (20K hGH) measured by a specific enzyme-linked immunosorbent assay. Study Group of 20K hGH

Several GH isoforms have been identified in pituitary and serum, the most abundant of which is the 22K human GH (hGH) isoform. The 20K hGH isoform is produced by alternative splicing of GH messenger ribonucleic acid and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined, partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunosorbent assays (ELISAs) specific to 20K and 22K hGH. To determine whether regulation of 20K hGH secretion is the same as that for 22K hGH, we measured serum concentrations of both species of hGH in normal subjects and patients with a variety of endocrine disorders. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (n = 282) in normal women, significantly higher than that in normal men (64 +/- 170 pg/mL; n = 226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, mean +/- SD; n = 176) and women (6.3 +/- 2.1%; n = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight, or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P < 0.001) higher in patients with active acromegaly (9.2 +/- 2.2%; n = 33) and patients with anorexia nervosa (9.0 +/- 1.9; n = 8), both of which are characterized by chronic elevation of circulating GH levels. The proportion of 20K hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or that a chronic excess of 22K hGH alters the MCR of 20K hGH. The values in patients with adult GH deficiency, hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests, such as the insulin tolerance test and the GHRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH. This new assay may provide a tool for understanding the physiological or pathophysiological role of the 20K hGH isoform.     

The three-dimensional structure of human RNase 4, unliganded and complexed with d(Up), reveals the basis for its uridine selectivity

The RNase 4 family is unique among RNase enzymes, displaying the highest level of sequence similarity and encompassing the shortest polypeptide chain. It is the only one showing high specificity. The human representative is an intracellular and plasma enzyme, first isolated from colon adenocarcinoma cell line HT-29. The crystal structures of human recombinant RNase 4, unliganded and in complex with d(Up), have been determined, revealing in the unique active site an explanation for the uridine specificity. Arg101, at a position not involved in catalysis in the other RNase enzymes, penetrates the enzyme moiety shaping the recognition pocket, a flip that is mediated by the interaction with the (shorter chain) C-terminal carboxylate group, providing an anchoring point for the O4 atom of the substrate uridine. The bulky Phe42 side-chain forces Asp80 to be in the chi1=-72.49 degrees rotamer, accepting a hydrogen bond from Thr44, further converting the latter into a hydrogen bond acceptor. This favours an interaction with the -NH-donor group of uridine at position 3 over that with the =N-acceptor of cytidine. The two chemical groups that distinguish uracyl from cytosine are used by the enzyme to discriminate between these two bases.     

Rheological flow models of banana peel pectin jellies as affected by sugar concentration

In the present study, peel pectin jellies (PPJ) were isolated from banana peel Musa acuminata Colla (AAA, cv ‘Berangan’) varieties using water bath extraction; five jellies were produced, namely, PPJ_68%, PPJ_70%, PPJ_71%, PPJ_72%, and PPJ_76%. The effect of sugar content on the rheology of the PPJ and commercial fruit jelly was conducted at 25°C within 0.05–100 s^?1 shear rate. Flow behaviour was evaluated on the test dispersions while frequency sweeps (E_a) to obtain the viscoelastic (G’ and G”) were performed on the jellies. PPJ dispersion showed shear thinning flow behaviour, a good fit to the Casson model. Sugar concentration does not affect Casson parameters (K_c, K_oc, ?_ca, and σ_oc). Frequency sweep decreased as viscosity increased which revealed high dependence for both G’ and G”. Tan δ for PPJ was more than unity which showed that jelly has less elastic properties. PPJ with the lowest sugar concentration, PPJ_68%, conducted at a high shear rate showed it was compatible with validation of the Cox–Merz rule.     

Visible-light sensitive hydrogen evolution photocatalyst ZnRh2O4

We investigated the ability of the oxide ZnRh₂O₄ to serve as a solar H₂-evolution photocatalyst due to the predicted potential of its conduction band bottom, which may allow thermodynamically favorable H₂ evolution in spite of its small band-gap of 1.2 eV. ZnRh₂O₄ produced H₂ in the presence of HCHO, but only scarcely in the presence of CH₃OH, indicating that the potential of the valence band top of ZnRh₂O₄ lies at ∼0.1 V (vs. SHE). Thus, the conduction band bottom potential (∼−1.1 V) lies much more negative than the potential of H⁺/H₂, allowing thermodynamically favorable H₂ evolution. In addition, the irradiated-light-wavelength dependence of the quantum efficiency (QE) for H₂ evolution was consistent with the solar spectrum, and the QE was quite high (∼27%), even at a wavelength of 770 ± 25 nm. Taken together, our findings indicate that ZnRh₂O₄ can utilize solar light effectively, not only the entire range of UV and visible light, but is also sensitive to infrared light.     

Analysis of in situ water transport in Nafion by confocal micro-Raman spectroscopy

A proton exchange membrane fuel cell (PEMFC) is a promising alternative source of clean power for automotive applications, but its acceptance in such applications depends on reducing its costs and increasing its power density to achieve greater compactness. To meet these requirements, further improvements in cell performance are required. In particular, when the fuel cell is operating at high current density, the transport of water through the membrane has considerable impacts on the performance because of the large concentration gradient of water between the cathode and anode. Through-plane water permeation across the membrane is therefore a fundamental process in operational PEMFCs. Recently, resistance to water transport at the membrane-gas interface has been reported, and this is affected by the temperature and relative humidity. We investigated the distribution of water inside a proton exchange membrane during a water permeation test by using confocal micro-Raman spectroscopy with a fine spatial resolution (2-3 μm). In the presence of a water flux, the local water content is not necessarily in equilibrium with the water activity in the gas phase. Interfacial water-transport resistance due to the presence of a non-equilibrium membrane structure at the interface cannot be neglected.     

Selective dissolution of nanolamellar Ti–41 at.% Al alloy single crystals

The selective dissolution behavior of Ti–41 at.% Al single crystals having a α₂/γ-lamellar structure with a lamellar thickness in the range 20 nm to 1 μm have been investigated in 0.5 M NaCl aqueous solution focusing on the effect of lamellar thickness on the dissolution of γ-lamellae. In the case where γ-lamellae were thicker than ～100 nm on average, γ-lamellae were selectively dissolved and, as a result, crevasses whose widths were close to the γ-lamellae thicknesses were formed. However, not all γ-lamellae were dissolved and the distribution of crevasses was much less uniform compared with that of the γ-lamellae. On the other hand, when the average γ-lamellae thickness was <100 nm relatively thick γ-lamellae were preferentially dissolved, but the distribution of the crevasses was relatively uniform compared with that obtained from the coarse lamellar structure. The reasons for this difference are discussed from the viewpoint of the absence of misfit dislocations in nanoscaled lamellae and the difference in ion transport through crevasses of different width formed by dissolution of γ-lamellae.     

Adsorption of cationic monomeric and gemini surfactants on montmorillonite and adsolubilization of vitamin E

Adsorption of a cationic gemini surfactant (1,2-bis(dodecyldimethylammonio) ethane dibromide, 12-2-12) and the corresponding monomeric surfactant (dodecyltrimethylammonium bromide, DTAB) on montmorillonite has been characterized with a combination of adsorption isotherm, interlayer spacing and FT-IR spectroscopic data. Adsolubilization of vitamin E into the adsorbed surfactant layers has also been studied. The adsorption isotherm data reveal that the adsorption of the two surfactants is driven by the two factors: one is the cation exchange that occurs on the interlayer basal planes and the other is the hydrophobic interaction between hydrocarbon chains of the surfactants. Although the adsorbed amount measured in the saturation region (in mol g(-1)) is almost identical for the two surfactants, the conformation of the intercalated surfactant molecules differs significantly from each other. The adsorption of DTAB results in a lateral bilayer arrangement in the limited interlayer space, whereas 12-2-12 gives a normal bilayer arrangement in the expanded interlayer space. Adsolubilization of vitamin E takes place into the adsorbed surfactant layers, and interestingly, all the vitamin E molecules added in the montmorillonite suspensions are hybridized at lower surfactant concentrations due to the great specific surface area of the clay material. Since the maximum adsolubilization amount is usually obtained just below the critical micelle concentration, the gemini surfactant is deemed to be more efficient than the corresponding monomeric one to achieve the great adsolubilization amount.