Intrinsically Stretchable Electrochromic Display by a Composite Film of Poly(3,4-ethylenedioxythiophene) and Polyurethane

A stretchable, electrochromic film of a uniform composite of poly­(3,4-ethylenedioxythiophene):<i>p</i>-toluene sulfonic acid (PEDOT:PTS) and polyurethane (PU) (PEDOT/PU) was fabricated, and its integration with a hydrogel as a free-standing, stretchable electrochromic (EC) display was demonstrated. The PEDOT/PU composite film was prepared by the spin coating of a solution containing an EDOT monomer and PU, followed by oxidative polymerization using iron­(III) tosylate at elevated temperature. The fabricated film showed reversible electrochromism without an external conductive support. The color change of the film can be used to quantify the progress of the redox reactions by means of digital camera image analysis and a custom mobile phone app

Effect of Antibiotics on Redox Transformations of Arsenic and Diversity of Arsenite-Oxidizing Bacteria in Sediment Microbial Communities

In the present study, we investigated the effect of antibiotics on microbial arsenate (As­(V)) reduction and arsenite (As­(III)) oxidation in sediments collected from a small pond and eutrophic lake. The As­(V)-reducing activities were less susceptible to chloramphenicol in aerobic conditions than in anaerobic conditions. Aerobic As­(V) reduction proceeded in the presence of diverse types of antibiotics, suggesting that As-resistant bacteria are widely antibiotic resistant. In contrast, some antibiotics, e.g., chloramphenicol, strongly inhibited aerobic As­(III) oxidation. In addition, bacterial As­(III) oxidase genes were scarcely amplified and Proteobacteria-related 16S rRNA genes drastically decreased in chloramphenicol-amended cultures. Erythromycin and lincomycin, which successfully target many Gram-positive bacteria, scarcely affected As­(III) oxidation, although they decreased the diversity of As­(III) oxidase genes. These results indicate that the aerobic As­(III) oxidizers in the sediment cultures are mainly composed of Proteobacteria and are more sensitive to certain types of antibiotics than the aerobic As­(V) reducers. Our results suggest that antibiotic disturbance of environmental microbial communities may affect the biogeochemical cycle of As

Changes in the bacterial community in the fermentation process of <i>kôso</i>, a Japanese sugar-vegetable fermented beverage

<p><i>Kôso</i> is a Japanese fermented beverage made with over 20 kinds of vegetables, mushrooms, and sugars. The changes in the bacterial population of <i>kôso</i> during fermentation at 25 °C over a period of 10 days were studied using 454 pyrosequencing of the 16S rRNA gene. The analysis detected 224 operational taxonomic units (OTUs) clustered from 8 DNA samples collected on days 0, 3, 7, and 10 from two fermentation batches. Proteobacteria were the dominant phylum in the starting community, but were replaced by Firmicutes within three days. Seventy-eight genera were identified from the 224 OTUs, in which <i>Bifidobacterium</i>, <i>Leuconostoc</i>, <i>Lactococcus</i>, and <i>Lactobacillus</i> dominated, accounting for over 96% of the total bacterial population after three days’ fermentation. UniFrac–Principal Coordinate Analysis of longitudinal fermented samples revealed dramatic changes in the bacterial community in <i>kôso</i>, resulting in significantly low diversity at the end of fermentation as compared with the complex starting community.</p> <p>Changes in the relative abundance of the 50 species in <i>kôso</i> communities during 10-day fermentation.</p

CRADs of the human infant gut microbiome.

<p>A: Clustering of the 13 human infant samples at the genus level. Hierarchal clustering is performed at the genus-level abundance of the human infant samples. Each genus is shown in a different color. B: Individual CRADs of gut microbiomes of 13 human infants based on the OTU-level composition. The CRADs of the gut microbiomes of the 13 infants (red) and the 104 healthy Japanese adults (black) are shown. C: Median CRADs of the same samples as those in (B). The CRADs of the gut microbiomes of the 13 infants (red) and the 104 healthy Japanese adults (black) are shown in the boxplot.</p

Concept of the mathematical model.

<p>To determine the species in the blue-shaded lattice (top), a species in the black shaded area (underneath) is randomly selected with probability <i>p</i>. A new additional species joins with probability 1-<i>p</i>.</p

Simulation of CRADs of infant and adult gut microbiomes.

<p>Red and blue boxes represent the CRADs of the gut microbiomes of the 13 infants and the 104 Japanese adults, respectively. The solid line and the dashed line represent the simulation results for <i>p</i> = 1.0 with 100 initial species and <i>p</i> = 0.999 with 200 initial species, respectively. Lattice size in the following simulations was (<i>x</i>, <i>y</i>, <i>z</i>) = (40, 40, 2000). The simulation results are obtained from the average of 100 repetitions.</p

CRADs of murine gut microbiomes.

<p>A: Clustering of the bacterial composition at the OTU level in mice. Hierarchal clustering is performed at the OTU-level abundance of the samples. Each OTU is shown in a different color. B: Individual CRADs of murine gut microbiomes based on the OTU-level composition. C: Median CRADs of the same samples as those in (B).</p

CRADs of the dissected mouse gut contents.

<p>S1-S4, C, and L indicate the contents of the small intestine, the cecum, and the large intestine, respectively.</p

Simulation of CRADs of mice microbiomes.

<p>The boxplot shows the observed CRADs of the combined samples, small and large intestine and cecum. Red and blue lines represent the average CRADs in the simulation with <i>p</i> = 1.0 and <i>p</i> = 0.9975, respectively, with 200 initial species. Lattice size in the following simulations was (<i>x</i>, <i>y</i>, <i>z</i>) = (40, 40, 2000). The simulation results are obtained from the average of 100 repetitions.</p

Simulation of CRADs of gut microbiomes in antibiotic-treated mice.

<p>The red and blue lines represent the CRADs of samples from two mice treated with antibiotics. Black boxplots represent the CRADs in the simulation with <i>p</i> = 1, where the growth rate of 197 of the 200 species was set to half that of the other 3 species. Lattice size in the following simulations was (<i>x</i>, <i>y</i>, <i>z</i>) = (40, 40, 2000). The simulation results are obtained from the average of 100 repetitions.</p