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The characterization of molecular mechanisms underlying the taste-sensing system of chickens will add to our understanding of their feeding behaviors in poultry farming. In the mammalian taste system, the heterodimer of taste receptor type 1 members 1/3 (T1R1/T1R3) functions as an umami (amino acid) taste receptor. Here, we analyzed the expression patterns of T1R1 and T1R3 in the taste cells of chickens, labeled by the molecular markers for chicken taste buds (vimentin and α-gustducin). We observed that α-gustducin was expressed in some of the chicken T1R3-positive taste bud cells but rarely expressed in the T1R1-positive and T2R7-positive taste bud cells. These results raise the possibility that there is another second messenger signaling system in chicken taste sensory cells. We also observed that T1R3 and α-gustducin were expressed mostly in the vimentin-positive taste bud cells, whereas T1R1 and bitter taste receptor (i.e., taste receptor type 2 member 7, T2R7) were expressed largely in the vimentin-negative taste bud cells in chickens. In addition, we observed that T1R1 and T1R3 were co-expressed in about 5% of chickens' taste bud cells, which express T1R1 or T1R3. These results suggest that the heterodimer of T1R1 and T1R3 is rarely formed in chickens’ taste bud cells, and they provide comparative insights into the expressional regulation of taste receptors in the taste bud cells of vertebrates.

Generating electric power using CO2 as a reactant is challenging because the electroreduction of CO2 usually requires a large overpotential. Herein, we report the design and development of a polymer electrolyte fuel cell driven by feeding H2 and CO2 to the anode (Pt/C) and cathode (Pt0.8Ru0.2/C), respectively, based on their theoretical electrode potentials. Pt-Ru/C is a promising electrocatalysts for CO2 reduction at a low overpotential; consequently, CH4 is continuously produced through CO2 reduction with an enhanced faradaic efficiency (18.2%) and without an overpotential (at 0.20 V vs. RHE) was achieved when dilute CO2 is fed at a cell temperature of 40 °C. Significantly, the cell generated electric power (0.14 mW·cm− 2) while simultaneously yielding CH4 at 86.3 µmol·g− 1·min− 1. These results show that a H2-CO2 fuel cell is a promising technology for promoting the carbon capture and utilization (CCU) strategy.

A functional fatty acid taste receptor, GPR120, is present in chicken oral tissues, and chickens show a preference for lipid in feed. However, it remains unclear whether chickens can detect fatty acids. To address this issue, we adopted 2 behavioral paradigms: a one-bowl drinking test to evaluate the preference for oleic acid solution and a conditioned taste aversion test to investigate the role of gustation in chickens' ability to detect oleic acid. In the one-bowl drinking test, chickens did not show any preference for solution containing 0.001, 0.01, 0.03, 0.1, or 30 mmol/L oleic acid although 30 mmol/L oleic acid was enough to fully activate GPR120, confirmed by Ca2+ imaging. On the other hand, chickens conditioned to avoid 30 mmol/L oleic acid solution also learned to avoid the solution. These results suggested that chickens have a gustatory perception of oleic acid solution but do not have a preference for it. The present results support the idea that chickens prefer lipid in feed, not only by a postingestive effect but also by sensing the taste of fatty acid.

It has been reported that the supplementation of chicken diet with polyunsaturated fatty acids (PUFAs) such as arachidonic acid (AA), eicosapentaenoic acid (EPA), or docosahexaenoic acid (DHA) affects the qualities of eggs and meat. Previous studies have shown that a functional fatty acid taste receptor, G protein-coupled receptor 120 (GPR120), is broadly expressed in chicken oral and gastrointestinal tissues, and chickens have a gustatory perception of oleic acid, which is a chicken GPR120 agonist. The aim of this study was to elucidate the role of chicken GPR120 in response to PUFAs in chicken diets. Ca

Mammalian taste buds comprise types I, II, and III taste cells, with each type having specific characteristics: glia-like supporting cells (type I), taste receptor cells (type II), and presynaptic cells (type III). In this study, to characterize the peripheral taste-sensing systems in chickens, we analyzed the distributions of the mammalian types I, II, and III taste cell markers in chicken taste buds: glutamate-aspartate transporter (GLAST) for type I; taste receptor type 1 members 1 and 3 (T1R1 and T1R3), taste receptor type 2 member 7 (T2R7), and α-gustducin for type II; and synaptosomal protein 25 (SNAP25) and neural cell adhesion molecule (NCAM) for type III. We found that most GLAST+ taste cells expressed α-gustducin and SNAP25 and that high percentages of T1R3+ or α-gustducin+ taste cells expressed SNAP25 and NCAM. These results demonstrated a unique subset of chicken taste cells expressing multiple taste cell type marker proteins. Taken together, these results provide new insights into the taste-sensing mechanisms in vertebrate taste buds.

The phytoflagellate Euglena gracilis produces a large amount of paramylon (PM), a conglomerate of liner β-1,3-glucan chains, as a storage polysaccharide. PM is synthesized from uridine diphosphate-glucose, but its mechanism of formation is largely unknown. Two enzymes, glucan synthase-like (EgGSL) 1 and EgGSL2 were previously identified as candidates for PM synthesis in a Euglena transcriptome analysis. Here, we performed a reverse genetic analysis on these enzymes. Knockdown of EgGSL2, but not EgGSL1, significantly inhibits PM accumulation in Euglena cells. Additionally, β-1,3-glucan synthesis is detected in a PM-associated membrane fraction extracted from Euglena cells. Our findings indicate that EgGSL2 is the predominant enzyme for PM biosynthesis.

Thick films of lacquers were coated by Wajima-nuri on yidaki (didgeridoo), a woodwind instrument loved by indigenous Australians from ancient times. Investigating frequency spectra of fast-frequency transform (FFT) before and after the coating revealed the significant enhancement of the sound pressure from the yidaki coated by Wajima-nuri, particularly in the low-frequency region. All peaks of sound pressures were shifted to higher frequencies by the Wajima-nuri. The improvement of sound characteristics was the most effective by the Wajima-nuri on both inside and outside the yidaki than that on the outside the yidaki only. It might be due to that lacquers soak through into perforated holes and cracks inherent to the original yidaki. Urushiol in lacquers tends to be solid by oxidative polymerization, which resulted in a smooth surface, and suppressed the turbulence of the air breathed. These results could be useful to many other instruments such as stringed, wind or percussion.

Plasma is becoming increasingly adopted in bioapplications such as plasma medicine and agriculture. This study investigates the interaction between plasma and molecules in living tissues, focusing on plasma-protein interactions. To this end, the reaction of air-pressure air plasma with NH2-terminated self-assembled monolayer is investigated by infrared spectroscopy in multiple internal reflection geometry. The atmospheric-pressure plasma decomposed the NH2components, the characteristic units of proteins. The decomposition is attributed to water clusters generated in the plasma, indicating that protein decomposition by plasma requires humid air.

Slow swelling and shrinking rates are a significant challenge for some applications of temperature-sensitive hydrogels. This study reports raspberry-form poly N,N-diethylacrylamide (DEAA) gel particles, which are aggregates of single spherical gel particles. The raspberry-form gel particles show improved temperature-response rates especially for swelling. This improvement in the response rate is attributed to two key factors: the free space between the individual gel particles that make up the aggregated gel particle, and the constraints from the contact points between the individual gel particles. During the swelling process, the polymer chain networks can diffuse at the faster rate characteristic of the individual gel particles constructing the raspberry-form gel, and consequently the response rate of the overall raspberry-form gels can be accelerated. During the shrinking process, the constraints from the contact points between the individual gels dominate the polymer chain diffusion and the shrinking rate because of non-zero shear modulus. The shrinking behavior was affected not by the individual particle size, but rather the apparent gel size and shape.

Background The phytoflagellated protozoan, Euglena gracilis, has been proposed as an attractive feedstock for the accumulation of valuable compounds such as β-1,3-glucan, also known as paramylon, and wax esters. The production of wax esters proceeds under anaerobic conditions, designated as wax ester fermentation. In spite of the importance and usefulness of Euglena, the genome and transcriptome data are currently unavailable, though another research group has recently published E.gracilis transcriptome study during our submission. We herein performed an RNA-Seq analysis to provide a comprehensive sequence resource and some insights into the regulation of genes including wax ester metabolism by comparative transcriptome analysis of E.gracilis under aerobic and anaerobic conditions. Results The E.gracilis transcriptome analysis was performed using the Illumina platform and yielded 90.3 million reads after the filtering steps. A total of 49,826 components were assembled and identified as a reference sequence of E.gracilis, of which 26,479 sequences were considered to be potentially expressed (having FPKM value of greater than 1). Approximately half of all components were estimated to be regulated in a trans-splicing manner, with the addition of protruding spliced leader sequences. Nearly 40 % of 26,479 sequences were annotated by similarity to Swiss-Prot database using the BLASTX program. A total of 2080 transcripts were identified as differentially expressed genes (DEGs) in response to anaerobic treatment for 24 h. A comprehensive pathway enrichment analysis using the KEGG pathway revealed that the majority of DEGs were involved in photosynthesis, nucleotide metabolism, oxidative phosphorylation, fatty acid metabolism. We successfully identified a candidate gene set of paramylon and wax esters, including novel β-1,3-glucan and wax ester synthases. A comparative expression analysis of aerobic- and anaerobic-treated E.gracilis cells indicated that gene expression changes in these components were not extensive or dynamic during the anaerobic treatment. Conclusion The RNA-Seq analysis provided comprehensive transcriptome information on E.gracilis for the first time, and this information will advance our understanding of this unique organism. The comprehensive analysis indicated that paramylon and wax ester metabolic pathways are regulated at post-transcriptional rather than the transcriptional level in response to anaerobic conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2540-6) contains supplementary material, which is available to authorized users.

The kinetics of swelling and shrinking of spherical particles of poly(N,N-diethylacrylamide) (DEAA) gel, prepared with static mixing technology, was investigated experimentally. The shrinking process was separated into late shrinking and initial shrinking by the skin layer effect. When the final temperature of temperature swing experiments was above the lower critical solution temperature (LCST) of polyDEAA, the apparent increase in the response rate constant (kv) and the polymer diffusion constant (D) were due to reduction of the friction coefficient between polymer chains and water, arising from decrease in the water viscosity. When the final temperature was below the LCST, the main factor determining kv and D was the change in the network structure of DEAA particles caused by the final temperature. The initial temperature affected the values of kv and apparent diffusion constant Dapp only in initial shrinking, in which the decrease in D with increase in the initial temperature came mainly from the spatial limitation.

Temperature-sensitive hydrogel beads were prepared by Kenics static mixer technology. The temperature-sensitive monomer N,N-diethylacrylamide and photo-crosslinkable pre-polymer ENT were used as model hydrogel materials. Drop dispersion of high viscosity polymer material in low viscosity hexadecane was made using the static mixer. Drops of a solution of the mixed materials were rapidly photo-crosslinked by UV irradiation after mixing in the static mixer, and spherical hydrogel beads with narrow, normal size distribution were thus prepared. The Kenics static mixer is a useful device for the preparation of spherical beads of temperature-sensitive hydrogels. The Sauter Mean Diameter of the hydrogel beads swollen in deionized water at 293 K was measured. The experimentally determined dimensionless swollen hydrogel bead diameter was well correlated with the Weber number, degree of swelling and viscosity ratio. The effects of gelation and ENT addition on the bead size were evaluated from the degree of swelling. The correlation equation can be used for size adjustment of temperature-sensitive spherical hydrogel beads.

Reactions involving hydrogen plasma and oxygen plasma with a self-assembled monolayer (SAM) of octadecyltrichlorosilane were investigated by infrared absorption spectroscopy in multiple internal reflection geometry. The rate of decrease of the CH3 peak intensity is smaller than that of the CH2 peak intensity when the SAM is exposed to hydrogen plasma. This is attributed to the formation of CH3 components as intermediate states of the hydrogenation of the SAM during hydrogen plasma exposure. Peak intensities due to CH2 and CH3 components in the SAM decreased at the same rate during oxygen plasma exposure. C=O components, detected during plasma exposure, are indicated as the intermediate states of film oxidation.

An in situ monitoring system for plasma-induced reactions in ethanol was developed by infrared absorption spectroscopy in multiple internal reflection geometry. We monitored in situ the preferential decrease in the IR peak intensity of CH3 and OH groups in liquid ethanol. In addition, we monitored in situ the preferential inclusion of OCH3 and free OH groups deposited on a multiple internal reflection prism. Unlike optical emission spectroscopy, the IR-based technique detects non-light-emitting compounds. It presents as a powerful alternative tool for monitoring liquid-phase plasma reactions.