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The ability to modulate optical and electrical properties of two-dimensional (2D) semiconductors has sparked considerable interest in transition metal dichalcogenides (TMDs). Herein, we introduce a facile strategy for modulating optoelectronic properties of monolayer MoSe2 with external light. Photochromic diarylethene (DAE) molecules formed a 2-nm-thick uniform layer on MoSe2, switching between its closed- and open-form isomers under UV and visible irradiation, respectively. We have discovered that the closed DAE conformation under UV has its lowest unoccupied molecular orbital energy level lower than the conduction band minimum of MoSe2, which facilitates photoinduced charge separation at the hybrid interface and quenches photoluminescence (PL) from monolayer flakes. In contrast, open isomers under visible light prevent photoexcited electron transfer from MoSe2 to DAE, thus retaining PL emission properties. Alternating UV and visible light repeatedly show a dynamic modulation of optoelectronic signatures of MoSe2. Conductive atomic force microscopy and Kelvin probe force microscopy also reveal an increase in conductivity and work function of MoSe2/DAE with photoswitched closed-form DAE. These results may open new opportunities for designing new phototransistors and other 2D optoelectronic devices. [ABSTRACT FROM AUTHOR]

The effects of concentration, temperature, and time on infusion of fluorescein into corn and waxy rice starches and their controlled release pattern were investigated. At low fluorescein concentration (1 μM), temperature significantly affected infusion efficiency. At high fluorescein concentration (50–150 μM), temperature showed little effect; fluorescein concentration significantly affected infusion efficiency. Corn starch showed relatively higher infusion efficiency than waxy rice starch at high concentration. During controlled release, 50% and 81% of infused fluorescein were released from corn and waxy rice starches, respectively, after bacterial α-amylase treatment. However, 61% and 68% of infused fluorescein were released from corn and waxy rice starches, respectively, after pancreatic α-amylase treatment. The dextrose equivalent (DE) value revealed similar patterns, suggesting that degradation of starch by different α-amylases is a major factor affecting release of fluorescein from starch granules. Moreover, granule size of starch greatly affected enzymatic hydrolysis and controlled release in this system. [ABSTRACT FROM AUTHOR]

Fluorescein isothiocyanate-dextrans (FDs) of different molecular weights were infused into corn, waxy rice, tapioca, and potato starches under atmospheric and high hydrostatic pressures (HHP). FD4, FD10, FD20, and FD40 (Mw 4000, 10,000, 20,000, and 40,000, respectively) were used as infusion materials. Confocal laser scanning microscopy confirmed that all FDs except FD40 infused into corn, waxy rice, and tapioca starches. However, no FDs infused into potato starch. Corn starch had the highest amounts of infused FDs. As molar mass increased, the amount of infused FD decreased in all starches. The infused amounts of FDs in corn starch were similar at 200–300 MPa and atmospheric pressure. Infusion of FDs at 400 MPa was reduced due to partial gelatinization. These results confirm that infusion efficiency is inversely proportional to the molecular weight of the infused material and large materials (Mw > 40,000) cannot be infused into starch granules under atmospheric pressure or HHP. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, strictly aerobic, non-flagellated, rod-shaped bacterium, designated GSB7T, was isolated from seawater collected at the Yellow Sea coast of South Korea. Catalase and oxidase activities were positive. Growth occurred at pH 6.0–9.0 (optimum pH 7.0), 10–40 °C (optimum 30 °C) and with 0–8% NaCl (optimum 1–2%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSB7T belonged to the genus Marivivens, showing the sequence similarities of 96.3, 96.1, and 96.0% with Marivivens niveibacter HSLHS2T, Limimaricola hongkongensis DSM17492T, and Marivivens donghaensis AM-4T, respectively. The respiratory quinone was ubiquinone-10 and the major fatty acids were summed feature 8 (C18:1ω7c and/or C18:1ω6c), C18:1ω7c 11-methyl, C16:0 and C10:0 3-OH. The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid, and five unidentified lipids. The DNA G + C content calculated from the whole-genome sequence was 60.6 mol%. On the basis of phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain GSB7T is suggested to represent a novel species of the genus Marivivens, for which the name Marivivens aquimaris sp. nov. is proposed. The type strain is GSB7T (= KCTC 82026T = JCM 34042T). [ABSTRACT FROM AUTHOR]

Bio-based production of industrially important chemicals provides an eco-friendly alternative to current petrochemical-based processes. Because of the limited supply of fossil fuel reserves, various technologies utilizing microbial host strains for the sustainable production of platform chemicals from renewable biomass have been developed. Corynebacterium glutamicum is a non-pathogenic industrial microbial species traditionally used for l-glutamate and l-lysine production. It is a promising species for industrial production of bio-based chemicals because of its flexible metabolism that allows the utilization of a broad spectrum of carbon sources and the production of various amino acids. Classical breeding, systems, synthetic biology, and metabolic engineering approaches have been used to improve its applications, ranging from traditional amino-acid production to modern biorefinery systems for production of value-added platform chemicals. This review describes recent advances in the development of genetic engineering tools and techniques for the establishment and optimization of metabolic pathways for bio-based production of major C2-C6 platform chemicals using recombinant C. glutamicum. [ABSTRACT FROM AUTHOR]

Effects of high hydrostatic pressure (HHP) and the propylene oxide (PO) concentration on the freeze-thaw stability, glass transition temperature ( Tg′), and retrogradation degree of HHP-assisted hydroxypropylated corn starch were investigated. HHP-assisted hydroxypropylated corn starches were prepared using propylene oxide (4, 8, and 12%, v/w) at 25°C for 15 min under HHP (100, 200, 300, and 400 MPa). The freeze-thaw stability, Tg′, ice melting enthalpy ( H), and retrogradation degree of HHP-assisted hydroxypropylated corn starches showed patterns different from native corn starch. In general, higher pressures and PO levels lowered Tg′ and H values, and the retrogradation degree. The highest freeze-thaw stability was observed in HHP-assisted hydroxypropylated corn starch prepared using 12% PO at 400 MPa for 15 min. Retrogradation kinetics of hydroxypropylated corn starch gels observed from the glass transition temperature, ice melting enthalpy, and retrogradation degree revealed that recrystallization occurred with instantaneous nucleation, followed by rod-like growth of crystals. [ABSTRACT FROM AUTHOR]

SnO@CoO hollow nano-spheres have been prepared using the template-based sol-gel coating technique and their electrochemical performance as an anode for lithium-ion battery (LIB) was investigated. The size of synthesized hollow spheres was about 50 nm with the shell thickness of 7-8 nm. The fabricated SnO@CoO hollow nano-sphere electrode exhibited an extraordinary reversible capacity (962 mAh·g after 100 cycles at 100 mA·g), good cyclability, and high rate capability, which was attributed to the Co-enhanced reversibility of the LiO reduction reaction during cycling. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Intracellular protein motors have evolved to perform specific tasks critical to the function of cells such as intracellular trafficking and cell division. Kinesin and dynein motors, for example, transport cargoes in living cells by walking along microtubules powered by adenosine triphosphate hydrolysis. These motors can make discrete 8 nm centre-of-mass steps and can travel over 1 µm by changing their conformations during the course of adenosine triphosphate binding, hydrolysis and product release. Inspired by such biological machines, synthetic analogues have been developed including self-assembled DNA walkers that can make stepwise movements on RNA/DNA substrates or can function as programmable assembly lines. Here, we show that motors based on RNA-cleaving DNA enzymes can transport nanoparticle cargoes-CdS nanocrystals in this case-along single-walled carbon nanotubes. Our motors extract chemical energy from RNA molecules decorated on the nanotubes and use that energy to fuel autonomous, processive walking through a series of conformational changes along the one-dimensional track. The walking is controllable and adapts to changes in the local environment, which allows us to remotely direct 'go' and 'stop' actions. The translocation of individual motors can be visualized in real time using the visible fluorescence of the cargo nanoparticle and the near-infared emission of the carbon-nanotube track. We observed unidirectional movements of the molecular motors over 3 µm with a translocation velocity on the order of 1 nm min−1 under our experimental conditions. [ABSTRACT FROM AUTHOR]

We deal with analysis and experiments of a novel moving-coil-type synchronous permanent magnet planar motor (SPMPM) with reduced cogging force. Our previous study assumed that the equation of magnetic flux existing between a permanent magnet (PM) and core was a second-order polynomial, and the minimum cogging force was theoretically and geometrically calculated without FE analysis. In this paper, the cogging force of SPMPM with an iron core is calculated exactly using geometrical factors, which are desired for determining the magnetic flux density. The analytical results of the cogging force using the factors agree well with those obtained by FE analysis and experiment. Several methods for reducing the cogging force of the SPMPM, such as separation and arrangement of the iron core, addition of an extra core, and addition of auxiliary core teeth, are introduced in this paper. Velocity control experiments of the SPMPM with modified and unmodified cores are carried out and the results are compared with each other. The velocity ripple of SPMPM with a modified core is much smaller than that of SPMPM with an unmodified core. [ABSTRACT FROM AUTHOR]

For an efficient production of retroviral vectors for gene therapy, the effect of serum concentrations in culture medium on the production and inactivation of retroviral vectors from the amphotropic producer cells (pMFG/ψCRIP) was investigated in various cultivation methods. The serum concentration in the range of 1–10% did not show any significant influence on the inactivation of retroviral vector at 37°C. The half-life of the vectors at 37°C was in the range of 2.0–2.7 hours. However, the serum concentration significantly influenced the cell growth as well as vector production. In a commonly used method where the medium was exchanged once after the cells reached subconfluency, the maximum cell concentration and vector titer in 10% serum were 2.31×105cells/cm2 and 6.2(±0.7; ±standard deviation)×105 colony forming unit (CFU)/ml, respectively. On the other hand, the maximum cell concentration and vector titer in 1% serum were only 1.12×105 cells/cm2 and 1.3(±0.3)×105 CFU/ml, respectively. Furthermore, a daily medium exchange did not enhance the cell growth and vector production in 1% serum. However, in 10% serum, a daily medium exchange allowed further cell growth and thereby enhanced the maximum vector titer (1.1(±0.1)×106 CFU/ml). In addition, since it also improved the maintenance of high cell concentration, the vector could be produced throughout 16 days culture, suggesting the feasibility of perfusion culture system for continuous production of high titer retroviral vector. [ABSTRACT FROM AUTHOR]

Functional interfaces between electronics and biological matter are essential to diverse fields including health sciences and bio-engineering. Here, we report the discovery of spontaneous (no external energy input) hydrogen transfer from biological glucose reactions into SmNiO3, an archetypal perovskite quantum material. The enzymatic oxidation of glucose is monitored down to ~5 × 10−16 M concentration via hydrogen transfer to the nickelate lattice. The hydrogen atoms donate electrons to the Ni d orbital and induce electron localization through strong electron correlations. By enzyme specific modification, spontaneous transfer of hydrogen from the neurotransmitter dopamine can be monitored in physiological media. We then directly interface an acute mouse brain slice onto the nickelate devices and demonstrate measurement of neurotransmitter release upon electrical stimulation of the striatum region. These results open up avenues for use of emergent physics present in quantum materials in trace detection and conveyance of bio-matter, bio-chemical sciences, and brain-machine interfaces. Functional materials that act as bio-sensing media when interfaced with complex bio-matter are attractive for health sciences and bio-engineering. Here, the authors report room temperature enzyme-mediated spontaneous hydrogen transfer between a perovskite quantum material and glucose reactions. [ABSTRACT FROM AUTHOR]