Daily oscillation of gene expression associated with nacreous layer formation

Three major organic matrix components, nacrein, MSI60 and N16 have been reported from the nacreous layer of Japanese pearl oyster, Pinctada fucata. Though several in vitro experiments have been carried out to elucidate the functions of these molecules details have not yet been clarified. In this report, we tempt to clarify the gene expression levels encoding the above three proteins between samples of 1) summer and winter seasons and 2) ocean and aquarium environments by using real-time polymerase chain reaction (PCR).It was confirmed that the biomineralization process of P. fucata is mainly influenced by the circatidal rhythm of the ocean environment. The gene expressions coding for N16 and MSI60 increased at the time of high tide, while that of nacrein increased at the time of low tide. The similar tendency observed in N16 and MSI60 showed the possibility that both components are secreted simultaneously, supporting a hypothesis that N16 forms cross-linkage with MSI60 to form the membrane. The expressions of MSI60, N16 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were remarkable in winter season, while no variation was found in the expression level of the nacrein gene in summer and winter season.The study is the first attempt regarding the seasonal and circadian rhythms observed on gene expressions incorporated into molluscan shell formation. The results will give a new insight into the relationship between molluscan physiology and the mechanism of shell formation.     

Liquid heating effects by SAW streaming on the piezoelectric substrate

When a liquid is placed on a surface acoustic wave (SAW) propagation surface, a longitudinal wave is radiated into the liquid, and the liquid begins to vibrate stream, jet, and atomize. This phenomenon is known as SAW streaming. In this paper, we describe experimental results concerning the temperature of a thin liquid layer during SAW generation. The results reveal that the temperature of the liquid is a function of the SAW amplitude, which is determined by the applied voltage. This means that the liquid temperature can be controlled by the applied voltage. We conclude that a novel microliquid heating system can be realized using the SAW device.     

Influence of antiferromagnetic ordering on ferroelectric polarization switching of YMnO3 epitaxial thin films

In this study, the switching behavior of ferroelectric polarization of (0001) YMnO(3) epitaxial films at around Néel temperature was investigated. From the experimental results of the frequency and temperature dependences of coercive electric filed (E(c)) obtained from polarization-electric field (P-E) hysteresis loop, the crosscorrelation phenomena between magnetics and ferroelectrics are discussed in detail. The P-E hysteresis loops of the films were measured in the frequency range from 1 Hz to 10 kHz, and the temperature was varied from 10 to 150 K. Frequency dependence of Ec accorded with Ishibashi-Orihara's theory at the measured temperature range. However, temperature dependence of E(c) disagreed with Devonshire's theory below 120 K, which is close to the Néeel temperature of the YMnO(3) epitaxial film. disagreed with Devonshire's theory below 120 K, which is close to the Neel temperature of the YMnO(3) epitaxial film.     

Profile of non-volatiles in whisky with regard to superoxide dismutase activity

SOD (Superoxide dismutase)-like activities of 23 kinds of single malt whisky (Scotch and Japanese) were evaluated. There was a positive correlation between SOD-like activity and the maturation age of whisky that exceeded the difference resulting from the manufacturing region. The SOD-like activity of Yamazaki 18, a typical single malt whisky in Japan, was approximately 1333 U/ml and that of non-volatile components in the whisky was 388U/mg, indicating that single malt whisky generally has a very strong SOD-like activity. To elucidate their contribution to SOD-like activity, the non-volatile components of whisky (Yamazaki 18) were ultrafiltered and separated with a Diaion HP20/water-EtOH system. Elution of the fraction less than 5000 molecular weight (<5000 MW fraction) with 60% (v/v) EtOH contributed most to SOD-like activity of the whisky. As this elution contained a considerable amount of polyphenolics, the content and SOD-like specific activity of ellagic acid, gallic acid, and lyoniresinol--the main whisky polyphenolics--were evaluated. The contribution of these compounds to the SOD-like activity of whisky was approximately 15%. Polyphenolics in whisky were relatively distributed to a higher MW fraction compared to carbohydrates in whisky, and specific activity (SOD-like activity per weight) of the >10,000 MW fraction was greater than that of the <5000 MW fraction, although the content of this fraction was low. These results indicate that various polyphenolics with higher molecular weights also contribute to the SOD-like activity of whisky together with main whisky polyphenolics.     

A novel adsorbent obtained by caging activated carbon by konjac glucomannan gel for elimination of organic compounds

In this study, the adsorptive ability of the konjac glucomannan gel containing activated carbon (KGMG–AC) was investigated by measuring the removal of several organic compounds with different charges, such as nitrobenzene (NB), methylene blue (MB), and rose bengale (RB). The physical and chemical properties, adsorption dynamics, adsorption isotherms, and the effect of pH of the adsorbents were compared with those of a commercially available powdered activated carbon (AC). The results of the present study indicate that the removal ratio of NB, MB, and RB onto KGMG–AC was slightly higher than that of the AC. The adsorption equilibrium constant (K_L) value (0.02 L/mg) of KGMG–AC for NB was similar to that of AC (0.03 L/mg). However, the saturated adsorption amount (Q₀) of KGMG–AC (368 mg/g) for NB was slightly larger than that of AC (354 mg/g). The saturated adsorption amounts of MB and RB on KGMG–AC were 302 and 259 mg/g, respectively. On the other hand, a high molecular weight humic acid was not adsorbed by KGMG–AC. Thus, entrapping AC into KGMG resulted in the selective adsorption. Therefore, this study could show that KGMG–AC was a new environmental friendly adsorbent that can be easily prepared, used, and recovered in environments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40542.     

Electrochemical detection and control of interactions between DNA and electroactive intercalator using a DNA-alginate complex film modified electrode

The surface of a glassy carbon electrode was modified with a DNA-alginate complex film in which water-soluble DNA was encapsulated into a calcium-alginate gel. The resulting modified electrode (DAFE) was used to detect ethidium bromide (EtBr), after its accumulation on the electrode. The intercalative behavior of EtBr for dsDNA in the film was investigated by measuring the electrode response based on the intercalation of EtBr separated from nonspecific interactions (electrostatic interaction). The accumulation of EtBr in the dsDAF was enhanced by applying a negative potential below -200 mV at the dsDAFE. When a positive potential above +700 mV was applied to the dsDAFE for a constant time with stirring in a Tris buffer solution, the amount accumulated decreased. These results indicate that it is possible to electrochemically control the accumulation and release of EtBr when a dsDAFE is used. In addition, the accumulation and detection of EtBr in spiked river water samples and daunomycin, an antitumor agent, is described.