Determination of Polycyclic Aromatic Hydrocarbons in the fecal Materials of Mactra veneriformis and Excrement of Marphysa sanguinea

The concentration of polycyclic aromatic hydrocarbons (PAHs) was measured in the sediment, a bivalve (Mactra veneriformis), fecal materials (feces and pseudofeces) of M. veneriformis, and excrement (feces) of an annelid (Marphysa sanguinea), which were collected in the Yoro tidal flat in Chiba, Japan. The total PAH concentration was 350 μg/kg-dry in the fecal materials of M. veneriformis and 977 μg/kg-dry in the excrement of M. sanguinea; these values were about 8–23 times as large as that of the sediment. The concentration of the fecal materials stayed constant even after 24 h, whereas that of the excrement decreased to half in 2 h. The sediment and fecal materials of M. veneriformis showed a high level of PAHs with lower molecular weight such as phenanthrene, fluoranthene, and pyrene; on the other hand, the excrement of M. sanguinea showed a high level of PAHs with higher molecular weight such as chrysene, benzo[b]fluoranthene, benzo[a]pyrene, and perylene. The logarithm of the concentration factor, defined as the ratio of the concentration of individual PAHs in the fecal materials or excrement to that in the sediment, correlated with the logarithm of the n-octanol/water partition coefficient for the PAHs (R ² = 0.803). These findings indicate that the sources and characteristics of the fecal materials of M. veneriformis and the excrement of M. sanguinea are different.     

Drinking Ice-Cold Water Reduces the Severity of Anticancer Drug-Induced Taste Dysfunction in Mice

Taste disorders are common adverse effects of cancer chemotherapy that can reduce quality of life and impair nutritional status. However, the molecular mechanisms underlying chemotherapy-induced taste disorders remain largely unknown. Furthermore, there are no effective preventive measures for chemotherapy-induced taste disorders. We investigated the effects of a combination of three anticancer drugs (TPF: docetaxel, cisplatin and 5-fluorouracil) on the structure and function of mouse taste tissues and examined whether the drinking of ice-cold water after TPF administration would attenuate these effects. TPF administration significantly increased the number of cells expressing apoptotic and proliferative markers. Furthermore, TPF administration significantly reduced the number of cells expressing taste cell markers and the magnitudes of the responses of taste nerves to tastants. The above results suggest that anticancer drug-induced taste dysfunction may be due to a reduction in the number of taste cells expressing taste-related molecules. The suppressive effects of TPF on taste cell marker expression and taste perception were reduced by the drinking of ice-cold water. We speculate that oral cryotherapy with an ice cube might be useful for prophylaxis against anticancer drug-induced taste disorders in humans.     

Evaluation of Fatigue Specimens Using EMATs for Nonlinear Ultrasonic Wave Detection

It is suggested that the waveform of the received ultrasonic wave is slightly different from that of the incident ultrasonic wave when the displacement of an ultrasonic wave and the opening width of a crack are almost same. Thus, as regarding the incident ultrasonic wave, its harmonic frequency components change as it penetrates the crack. Since, the nonlinearity of a solid material is very small compared to that of a liquid medium with a high nonlinear efficiency when used as a coupling medium, we applied an electromagnetic acoustic transducer (EMAT), which does not require a coupling medium. In addition, we tried to develop the EMAT that could alternately drive S₀-Lamb wave and fundamental Shear Horizontal (SH₀)-plate wave to detect any nonlinearity in an ultrasonic wave. We actually tested the performance using the fatigue specimens we fabricated. As a result, we observed that the harmonic components changed when we used the specimen with a specific loading condition and a specific ultrasonic mode. This is indicated that the harmonic components detection using the trial EMAT could also provide useful information on the degree of damage to any structures or any materials.     

Modulating the Mechanical Performance of Macroscale Fibers through Shear‐Induced Alignment and Assembly of Protein Nanofibrils

Protein‐based fibers are used by nature as high‐performance materials in a wide range of applications, including providing structural support, creating thermal insulation, and generating underwater adhesives. Such fibers are commonly generated through a hierarchical self‐assembly process, where the molecular building blocks are geometrically confined and aligned along the fiber axis to provide a high level of structural robustness. Here, this approach is mimicked by using a microfluidic spinning method to enable precise control over multiscale order during the assembly process of nanoscale protein nanofibrils into micro‐ and macroscale fibers. By varying the flow rates on chip, the degree of nanofibril alignment can be tuned, leading to an orientation index comparable to that of native silk. It is found that the Young's modulus of the resulting fibers increases with an increasing level of nanoscale alignment of the building blocks, suggesting that the mechanical properties of macroscopic fibers can be controlled through varying the level of ordering of the nanoscale building blocks. Capitalizing on strategies evolved by nature, the fabrication method allows for the controlled formation of macroscopic fibers and offers the potential to be applied for the generation of further novel bioinspired materials.     

Polymerization of Substituted Acetylenes Using Well‐Defined Rhodium Complex Catalyst. Chirality Transfer and Amplification in Chiral‐Chiral Block and Random Copolymers

Block and random copolymers are synthesized by the copolymerization of N‐tert‐butoxycarbonyl‐?‐valine 4‐ethynylanilide ( 1L ) and N‐tert‐butoxycarbonyl‐d‐valine 4‐ethynylanilide ( 1D ) using [(nbd)Rh{C(Ph) = CPh₂}(PPh₃)]/PPh₃ as a catalyst. The size exclusion chromatography (SEC) peaks show narrow polydispersities from the first stage polymerization to the second one in the block copolymerization. Poly( 1L ₂₅‐ran‐ 1D ₂₅) exhibits no circular dichroism (CD) signal, while poly( 1L ₂₅)‐block‐poly( 1D ₂₅) exhibits weak CD signals with the same sign as those of poly( 1L ₅₀), suggesting the occurrence of chirality transfer from the poly( 1L ) block to poly( 1D) block. The relationship between the |g| values and 1L / 1D contents of the block copolymers becomes almost linear at the region of each unit larger than 60%. On the other hand, the relationship between these two factors of the random copolymers is convex upward.     

Consumption of lily bulb modulates fecal ratios of firmicutes and bacteroidetes phyla in rats fed a high-fat diet

Food Science and Biotechnology - Different ascorbic acid (AA) concentrations of 0.16, 0.20, and 0.24% (w/v) were added to pear juice from the new cultivar Pyrus pyrifolia Nakai cv....     

Novel 2,2,6,6‐Tetramethylpiperidine 1‐Oxyl–Iodobenzene Hybrid Catalyst for Oxidation of Primary Alcohols to Carboxylic Acids

Novel bifunctional hybrid‐type catalysts bearing 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) and iodobenzene moieties ( 1a and 1b ) were developed and used for the environmentally benign oxidation of primary alcohols to carboxylic acids. Reaction of primary alcohols 2 with a catalytic amount of 1 in the presence of peracetic acid as a co‐oxidant under mild conditions gave the corresponding carboxylic acids 3 in excellent yields.     

Improvement of power conversion efficiency of soft‐switching inverter in range of low output power by adjustable dead time control

The power conversion efficiency of soft‐switching inverters can be improved by using loss‐less snubber commutation; however, the main switches of the inverter fail in zero‐voltage turn‐on when the output current is small. As a solution to this problem, adjustable dead time control in a loss‐less snubber commutation according to the magnitude of output current has been proposed. Adjustable dead time control achieves zero‐voltage turn‐on of the inverter main switches in a loss‐less snubber commutation in the range of low output current; however, waveforms of the output current of the inverter become distorted. In this paper, we propose a scheme for adjustable dead time control with dead time compensation for soft‐switching inverters. The effectiveness of the proposed control scheme is verified by experiments. Experimental results demonstrate that when the proposed control scheme is adopted, the power conversion efficiency in the range of low output power improves up to about 3% and the THD is improved within 3%. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(1): 57–64, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21282     

Efficient molecular weight control of bacterially synthesized polyesters by alcohol supplementation

The bacterial plastic poly(3‐hydroxybutyrate) (PHB) has many practical applications but its commercial potential is presently limited, partly due to the challenge of achieving appropriate mechanical performance characteristics. One method of tailoring the physical properties of the polymer is to control its molecular weight, which can be achieved by the addition of chain transfer agents such as poly(ethylene glycol) (PEG) to the culture medium during production. For the first time, PEG has been compared directly with alternative chain transfer agents, all of which contain at least one hydroxyl group. Methanol, ethanol and isopropanol all reduced the molecular weight of PHB produced by transgenic Escherichia coli by the same amount as PEG (～60%). PEG‐treated cultures grew to lower density and produced less PHB than control or alcohol‐treated cultures. Glycerol and sodium acetate were also tested, but only reduced the molecular weight by 15–24%. Naturally occurring short chain alcohols such as methanol and ethanol are a superior choice of chain transfer agent than the currently preferred PEG, as they achieve the same effect with reduced toxicity and are substantially less expensive. © 2013 Society of Chemical Industry     

Improvement of Porous Si Luminescence Intensity Durability by Nitrogen Ion Irradiation Using an ECR Ion Source

We have investigated the effects of the porous Si surface passivation by oxygen or nitrogen ion processing on the photoluminescence (PL) intensity and its stability using an electron cyclotron resonance ion source. The results indicate that an anneal before exposure to ion beam causes a PL intensity enhancement upon exposure to oxygen or nitrogen ion beam. A combination of an anneal and a passivation by exposure to nitrogen ion beam enhances the PL intensity by a factor of 2.5 compared to the intensity of the initial as-anodized PS and the enhanced intensity is stabilized for more than 180 min under Ar⁺-laser illumination while oxygen-ion-exposed PS exhibits an enhancement in PL intensity only by 1.4 and a decay in PL intensity by 20% after 180 min Ar⁺-laser illumination. The results suggest that the reaction of nitrogen with a PS surface plays a key role for the PL intensity enhancement and stability.