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In this study, polyolefin elastomer (POE) was blended with a chemically modified hydrocarbon resin (m-HCR), which was modified through a simple radical grafting reaction using γ-methacryloxypropyl trimethoxy silane (MTS) as an adhesion promotor to the glass surface, to design an adhesion-enhanced polyolefin encapsulant material for photovoltaic modules. Its chemical modification was confirmed by 1H and 29Si NMR and FT-IR. Interestingly, the POE blends with the m-HCR showed that the melting peak temperature (Tm) was not changed. However, Tm shifted to lower values with increasing m-HCR content after crosslinking. Additionally, the mechanical properties did not significantly differ with increasing m-HCR content. Meanwhile, with increasing m-HCR content in the POE blend, the peel strength increased linearly without sacrificing their transmittance. The test photovoltaic modules comprising the crosslinked POE blend encapsulants showed little difference in the electrical performance after manufacturing. After 1000 h of damp-heat exposure, no significant power loss was observed.

Pandemic and endemic strains of Vibrio cholerae arise from toxigenic conversion by the CTXφ bacteriophage, a process by which CTXφ infects nontoxigenic strains of V. cholerae. CTXφ encodes the cholera toxin, an enterotoxin responsible for the watery diarrhea associated with cholera infections. Despite the critical role of CTXφ during infections, signals that affect CTXφ-driven toxigenic conversion or expression of the CTXφ-encoded cholera toxin remain poorly characterized, particularly in the context of the gut mucosa. Here, we identify mucin polymers as potent regulators of CTXφ-driven pathogenicity in V. cholerae. Our results indicate that mucin-associated O-glycans block toxigenic conversion by CTXφ and suppress the expression of CTXφ-related virulence factors, including the toxin co-regulated pilus and cholera toxin, by interfering with the TcpP/ToxR/ToxT virulence pathway. By synthesizing individual mucin glycan structures de novo, we identify the Core 2 motif as the critical structure governing this virulence attenuation. Overall, our results highlight a novel mechanism by which mucins and their associated O-glycan structures affect CTXφ-mediated evolution and pathogenicity of V. cholerae, underscoring the potential regulatory power housed within mucus.

Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is Komagataeibacter xylinus. However, due to limited tools of expression, this host is difficult to engineer metabolically to improve BC productivity. In this study, a regulated expression system for K. xylinus with synthetic ribosome binding site (RBS) was developed and used to engineer a BC biosynthesis pathway. A synthetic RBS library was constructed using green fluorescent protein (GFP) as a reporter, and three synthetic RBSs (R4, R15, and R6) with different strengths were successfully isolated by fluorescence-activated cell sorting (FACS). Using synthetic RBS, we optimized the expression of three homologous genes responsible for BC production, pgm, galU, and ndp, and thereby greatly increased it under both static and shaking culture conditions. The final titer of BC under static and shaking conditions was 5.28 and 3.67 g/l, respectively. Our findings demonstrate that reinforced metabolic flux towards BC through quantitative gene expression represents a practical strategy for the improvement of BC productivity.

In this paper, we report a full-color reflective display device by combining reflective electrochromic device (ECD) and different color production units (conventional color filter (CF) and transmittance controllable electrochromic color filter (TCECF)). A full-color reflective device with TCECF showed an excellent diffuse reflectance of 47.2% in the white state owing to the high transmittance of TCECF in the bleached state than that of CF (19.5%). This device structure can easily provide various colors with high brightness and saturation with a broad grayscale. Particularly, in the colored state, TCECF and CF-based full-color reflective device displayed color coordinates of (0.59, 0.34), (0.31, 0.66), (0.24, 0.30) and (0.65, 0.33), (0.27, 0.61), (0.15, 0.06), for red, green and blue, respectively, and alongside also exhibited color gamut of 36.8% (for TCECF) and 73.1% (for CF) for full color reflective devices.

Using a simple esterification reaction of a hydroxyl group with an anhydride group, pristine lignin was successfully converted to a new lignin (COOH-lignin) modified with a terminal carboxyl group. This chemical modification of pristine lignin was confirmed by the appearance of new absorption bands in the FT-IR spectrum. Then, the pristine lignin and COOH-lignin were successfully incorporated into a poly(lactic acid) (PLA) matrix by a typical melt-mixing process. When applied to the COOH-lignin, interfacial adhesion performance between the lignin filler and PLA matrix was better and stronger than pristine lignin. Based on these results for the COOH-lignin/PLA biocomposites, the cost of printing PLA 3D filaments can be reduced without changing their thermal and mechanical properties. Furthermore, the potential of lignin as a component in PLA biocomposites adequate for 3D printing was demonstrated.

Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is

Biofilm formation by Vibrio cholerae facilitates environmental persistence, and hyperinfectivity within the host. Biofilm formation is regulated by 3’,5’-cyclic diguanylate (c-di-GMP) and requires production of the type IV mannose-sensitive hemagglutinin (MSHA) pilus. Here, we show that the MSHA pilus is a dynamic extendable and retractable system, and its activity is directly controlled by c-di-GMP. The interaction between c-di-GMP and the ATPase MshE promotes pilus extension, whereas low levels of c-di-GMP correlate with enhanced retraction. Loss of retraction facilitated by the ATPase PilT increases near-surface roaming motility, and impairs initial surface attachment. However, prolonged retraction upon surface attachment results in reduced MSHA-mediated surface anchoring and increased levels of detachment. Our results indicate that c-di-GMP directly controls MshE activity, thus regulating MSHA pilus extension and retraction dynamics, and modulating V. cholerae surface attachment and colonization., Biofilm formation by Vibrio cholerae is regulated by c-di-GMP and requires the type IV MSHA pilus. Here, Floyd et al. show that the MSHA pilus is a dynamic system, and that both extension and retraction are directly controlled by c-di-GMP via regulation of activity of the extension ATPase MshE.

Highly efficient single-stack hybrid cool white organic light-emitting diodes (OLEDs) having blue-yellow-blue multiple emitting layers (EMLs) are designed and constructed by utilizing blue thermally activated delayed fluorescent (TADF) and yellow phosphorescent emitters. The out-coupling efficiencies of yellow and blue emissions are maximized by tuning the ITO and total device thickness that satisfies both of antinode positions for yellow and blue emissions in a limited multiple EML thickness. To obtain a cool white emission, the exciton formation ratio in the blue-yellow-blue multiple EML system is controlled by manipulating the recombination zone through charge conductivity variation of host medium in the blue TADF EML. The resulting device exhibits cool white emission with very high maximum external quantum efficiency of 23.1% and CIE color coordinates of (0.324, 0.337). We anticipate that the studied approach will raise the viability of single-stack hybrid cool white OLEDs for high performance display applications.

Background Computation of reaction similarity is a pre-requisite for several bioinformatics applications including enzyme identification for specific biochemical reactions, enzyme classification and mining for specific inhibitors. Reaction similarity is often assessed at either two levels: (i) comparison across all the constituent substrates and products of a reaction, reaction level similarity, (ii) comparison at the transformation center with various degrees of neighborhood, transformation level similarity. Existing reaction similarity computation tools are designed for specific applications and use different features and similarity measures. A single system integrating these diverse features enables comparison of the impact of different molecular properties on similarity score computation. Results To address these requirements, we present SimCAL, an integrated system to calculate reaction similarity with novel features and capability to perform comparative assessment. SimCAL provides reaction similarity computation at both whole reaction level and transformation level. Novel physicochemical features such as stereochemistry, mass, volume and charge are included in computing reaction fingerprint. Users can choose from four different fingerprint types and nine molecular similarity measures. Further, a comparative assessment of these features is also enabled. The performance of SimCAL is assessed on 3,688,122 reaction pairs with Enzyme Commission (EC) number from MetaCyc and achieved an area under the curve (AUC) of > 0.9. In addition, SimCAL results showed strong correlation with state-of-the-art EC-BLAST and molecular signature based reaction similarity methods. Conclusions SimCAL is developed in java and is available as a standalone tool, with intuitive, user-friendly graphical interface and also as a console application. With its customizable feature selection and similarity calculations, it is expected to cater a wide audience interested in studying and analyzing biochemical reactions and metabolic networks. Electronic supplementary material The online version of this article (10.1186/s12859-018-2248-5) contains supplementary material, which is available to authorized users.

In this paper, we report two new phenanthroline-based compounds, 1,4-bis(2-phenyl-1,10-phenanthrolin-4-yl)benzene (p-bPPhenB) and 1,3-bis(2-phenyl-1,10-phenanthrolin-4-yl)benzene (m-bPPhenB), for the charge generation unit of tandem organic light-emitting diodes (OLEDs). These two compounds exhibited high electron mobility of (5.8–4.4) × 10–3 cm2/(V s), a very small injection barrier at the p–n junction interface, a high glass transition temperature of 123.9–182.1 °C, and exceptionally good operational stability. Because of such excellent characteristics, a single-stack red phosphorescent OLED (PhOLED) with p-bPPhenB showed a low driving voltage (2.7 V) and significantly improved maximum power efficiency (56.8 lm/W), external quantum efficiency (30.8%), and device lifetime (LT95, 130 h) compared to those of the control device using bathophenanthroline (Bphen) (3.7 V, 39 lm/W, 27.1%, and 13 h). Furthermore, a two-stack (tandem) red PhOLED using p-bPPhenB in the charge generation unit exhibited superior cha...

Spinel-embedded lithium-rich oxides are synthesized and their structural phases are analyzed. The type of spinel LiM0.5Mn1.5O4 (M = Ni, Co, Mn) embedded is varied by controlling the spinel composition and content. Of the various composites fabricated with different spinel phases, the LiCo0.5Mn1.5O4-embedded over-lithiated layered oxide (OLO) shows the best electrochemical performance as a cathode because of the absence of a parasitic phase and its high structural stability. The formation energy of the LiCo0.5Mn1.5O4-embedded oxide is determined through first-principles calculations and is found to be lower than that of the pristine oxide as well as other spinel-phase-embedded oxides. It is also observed that use of OLO with optimal embedded spinel LiCo0.5Mn1.5O4 in a cylindrical 18650-type cell results in improvement in the full-cell electrochemical performance.

Vibrio cholerae, the causative agent of the diarrheal disease cholera, benefits from a sessile biofilm lifestyle that enhances survival outside the host but also contributes to host colonization and infectivity. The bacterial second messenger c-di-GMP has been identified as a central regulator of biofilm formation, including in V. cholerae; however, our understanding of the pathways that contribute to this process is incomplete. Here, we define a conserved signaling system that controls the stability of large adhesion proteins at the cell surface of V. cholerae, which are important for cell attachment and biofilm formation. Insight into the regulatory circuit underlying biofilm formation may inform targeted strategies to interfere with a process that renders this bacterium remarkably adaptable to changing environments., The dinucleotide second messenger c-di-GMP has emerged as a central regulator of reversible cell attachment during bacterial biofilm formation. A prominent cell adhesion mechanism first identified in pseudomonads combines two c-di-GMP-mediated processes: transcription of a large adhesin and its cell surface display via posttranslational proteolytic control. Here, we characterize an orthologous c-di-GMP effector system and show that it is operational in Vibrio cholerae, where it regulates two distinct classes of adhesins. Through structural analyses, we reveal a conserved autoinhibition mechanism of the c-di-GMP receptor that controls adhesin proteolysis and present a structure of a c-di-GMP-bound receptor module. We further establish functionality of the periplasmic protease controlled by the receptor against the two adhesins. Finally, transcription and functional assays identify physiological roles of both c-di-GMP-regulated adhesins in surface attachment and biofilm formation. Together, our studies highlight the conservation of a highly efficient signaling effector circuit for the control of cell surface adhesin expression and its versatility by revealing strain-specific variations.

Significance This report describes an opportunity for the bacterial cellulose nanofiber (BCNF) membrane, which has recently been attracting much attention due to its sustainability and high thermal stability, as a “single-layer,” good alternative membrane to the existing chemical-derived one in batteries, and thus allows us to find possible solutions to the environmental and safety issues. We achieved highest BCNF yield ever reported so far and fabricated a cylindrical lithium ion battery (LIB) by roll-to-roll process to realize remarkable cycle stability with 80% capacity retention even after 1,000 cycles, which is comparable to those of commercialized batteries. Finally, we introduced a Lewis base to improve thermal safety of the battery to a level comparable to that of a commercial ceramic-coated separator.

Conventional interatomic potential methods for Li-ion battery cathode materials normally use fixed-charge models, which are not accurate enough to model the dynamical oxidation state change of transition metals during electrochemical reactions. In order to enable more accurate large-scale simulations for battery cathode materials, here we report a semiempirical interatomic potential of the Li-Ni-O ternary system based on an advanced dynamic charge method: Charge-Transfer Modified Embedded-Atom Method (CT-MEAM). The potential is parameterized by fitting the atomic Bader charges and energy-strain curves of the LiNiO 2 cathode material under uniaxial, biaxial and hydrostatic strains to results obtained with ab initio density-functional theory (DFT) calculations. A variety of structural, electrochemical and dynamical properties derived from the fitted CT-MEAM potential are observed to be in excellent agreement with previous DFT and experimental data. The transferability of the potential is validated by comparing relative phase stabilities and charge distribution states within the ternary Li-Ni-O systems. Our results support the capability of the present CT-MEAM to model complex ternary transition metal oxides. This method will facilitate not only the optimal design of Lithium-ion battery cathode materials, but also other transition metal oxide-based applications involving electrochemical reactions.

Lactic acid (LA) is a versatile compound used in the food, pharmaceutical, textile, leather, and chemical industries. Biological production of LA is possible by yeast strains expressing a bacterial gene encoding l-lactate dehydrogenase (LDH). Kluyveromyces marxianus is an emerging non-conventional yeast with various phenotypes of industrial interest. However, it has not been extensively studied for LA production. In this study, K. marxianus was engineered to express and co-express various heterologous LDH enzymes that were reported to have different pH optimums. Specifically, three LDH enzymes originating from Staphylococcus epidermidis (SeLDH; optimal at pH 5.6), Lactobacillus acidophilus (LaLDH; optimal at pH 5.3), and Bos taurus (BtLDH; optimal at pH 9.8) were functionally expressed individually and in combination in K. marxianus, and the resulting strains were compared in terms of LA production. A strain co-expressing SeLDH and LaLDH (KM5 La+SeLDH) produced 16.0g/L LA, whereas the strains expressing those enzymes individually produced only 8.4 and 6.8g/L, respectively. This co-expressing strain produced 24.0g/L LA with a yield of 0.48g/g glucose in the presence of CaCO3. Our results suggest that co-expression of LDH enzymes with different pH optimums provides sufficient LDH activity under dynamic intracellular pH conditions, leading to enhanced production of LA compared to individual expression of the LDH enzymes.

Water-based systems are dominating the coating market because of worldwide VOCs regulations. Research is focusing especially on waterborne polyurethane (WPU) because of its unique mechanical and chemical properties. However, commercial WPU consists of linear thermoplastic polymers with polar groups on the main chain, which do not perform as well as solvent-borne PU in a two-pack system. In this study, APTES were used as a chain crosslink agent to overcome commercial WPU`s limited performance. WPUs synthesized by using a sol-gel process were evaluated with FT-IR, particle analysis, TGA, tensile tests, pull-off tests, SEM, and EIS. The results showed that WPUs with added APTES had better thermal stability, mechanical properties, and water resistance than did WPUs without added APTES. Consequently, the sol-gel process increased the crosslink density of WPUs and modified the WPU`s own properties.

The assembly status of the V. cholerae flagellum regulates biofilm formation, suggesting that the bacterium senses a lack of movement to commit to a sessile lifestyle. Motility and biofilm formation are inversely regulated by the second messenger molecule cyclic dimeric guanosine monophosphate (c-di-GMP). Therefore, we sought to define the flagellum-associated c-di-GMP-mediated signaling pathways that regulate the transition from a motile to a sessile state. Here we report that elimination of the flagellum, via loss of the FlaA flagellin, results in a flagellum-dependent biofilm regulatory (FDBR) response, which elevates cellular c-di-GMP levels, increases biofilm gene expression, and enhances biofilm formation. The strength of the FDBR response is linked with status of the flagellar stator: it can be reversed by deletion of the T ring component MotX, and reduced by mutations altering either the Na+ binding ability of the stator or the Na+ motive force. Absence of the stator also results in reduction of mannose-sensitive hemagglutinin (MSHA) pilus levels on the cell surface, suggesting interconnectivity of signal transduction pathways involved in biofilm formation. Strains lacking flagellar rotor components similarly launched an FDBR response, however this was independent of the status of assembly of the flagellar stator. We found that the FDBR response requires at least three specific diguanylate cyclases that contribute to increased c-di-GMP levels, and propose that activation of biofilm formation during this response relies on c-di-GMP-dependent activation of positive regulators of biofilm production. Together our results dissect how flagellum assembly activates c-di-GMP signaling circuits, and how V. cholerae utilizes these signals to transition from a motile to a sessile state., Author summary A key regulator of Vibrio cholerae physiology is the nucleotide-based, second messenger cyclic dimeric guanosine monophosphate (c-di-GMP). We found that the status of flagellar biosynthesis at different stages of flagellar assembly modulates c-di-GMP signaling in V. cholerae and identified diguanylate cyclases involved in this regulatory process. The effect of motility status on the cellular c-di-GMP level is partly dependent on the flagellar stator and Na+ flux through the flagellum. Finally, we showed that c-di-GMP-dependent positive regulators of biofilm formation are critical for the signaling cascade that connects motility status to biofilm formation. Our results show that in addition to c-di-GMP promoting motile to biofilm lifestyle switch, “motility status” of V. cholerae modulates c-di-GMP signaling and biofilm formation.

To meet the requirement of large-scale simulation technics for Li-ion battery electrode materials, we introduce the charge-transfer modified embedded-atom method (CT-MEAM) in which the complex nature of the chemical bonding in transition metal (TM) oxides is described as a balance between metallic/covalent and ionic contributions by MEAM and a variable-charge model, respectively. The method is applied to Li 2 MnO 3 , and the parameterization is performed through fitting the energy–strain curves of Li 2 MnO 3 under uniaxial, biaxial and hydrostatic strains to a training set from ab initio density-functional theory calculations. The CT-MEAM prediction of the critical physical properties such as charge states and redox potentials match quite well with the ab initio results in various Li–Mn–O compounds beyond Li 2 MnO 3 . The constructed Li–Mn–O phase diagram is also qualitatively consistent with the ab initio reference work. The excellent transferability ensures use of the present method for a wide range of oxidation states in complex ternary TM oxides. Therefore, it will facilitate large-scale atomistic calculations required for the optimal design of many TM oxide applications including lithium-ion battery cathode materials.

A facile method is developed to improve the initial reversible capacity of hollow carbon nanofibers (HCNFs), which are manufactured via coaxial electrospinning of core/shell precursor nanofibers and their thermal treatments for stabilization and carbonization. Since the low initial reversible capacity of HCNFs is mainly caused by mesopores in the HCNFs, in our approach, the size of these mesopores is reduced by simply introducing a chemical vapor deposition (CVD) process between the stabilization and carbonization processes, thereby inducing the deposition of carbon atoms in the mesopores. The initial coulombic efficiencies of the HCNFs and the Si-encapsulated HCNFs are significantly increased by employing CVD process. The mechanism behind such improvement is revealed by morphological, microstructural, surface, and electrochemical analyses, confirming that control of the mesopores in HCNFs is an effective means to improve the electrochemical performance of HCNFs.

A fundamental understanding of the anodic stabilities of electrolytes is important for the development of advanced high-voltage electrolytes. In this study, we calculated and systematically compared the oxidation stabilities of monomeric solvents and anions, and bimolecular solvent–solvent and anion–solvent systems that are considered to be high-voltage electrolyte components, using ab initio calculations. Oxidation stabilities of solvent or anion monomers without considering specific solvation molecules cannot represent experimental oxidation stabilities. The oxidation of electrolytes usually forms neutral or cationic radicals, which immediately undergo further reactions stabilizing the products. Oxidatively driven intermolecular reactions are the main reason for the lower oxidation stabilities of electrolytes compared with those of monomeric compounds. Electrolyte components such as tetramethylene sulfone (TMS), ethyl methyl sulfone (EMS), bis(oxalate)borate (BOB − ), and bis(trifluoromethane)sulfonamide (TFSI − ) that minimize such intermolecular chemical reactions on oxidation can maintain the oxidation stabilities of monomers. In predictions of the theoretical oxidation stabilities of electrolytes, simple comparisons of highest occupied molecular orbital energies can be misleading, even if microsolvation or bulk clusters are considered. Instead, bimolecular solvent complexes with a salt anion should be at least considered in oxidation calculations. This study provides important information on fundamental and applied aspects of the development of electrolytes.

Thermal stability is one of the critical requirements for commercial operation of high energy lithium-ion batteries. In this study, we use in situ X-ray diffraction technique to elucidate the thermal degradation mechanism of 0.5Li 2 MnO 3 -0.5LiNi 0.33 Co 0.33 Mn 0.33 O 2 lithium rich cathode material in the absence and presence of electrolyte to simulate the real life battery conditions and compare its thermal behavior with the commercial LiNi 0.33 Co 0.33 Mn 0.33 O 2 cathode material. We show that the thermal induced phase transformations in delithiated lithium rich cathode material are much more intense compared to similar single phase layered cathode material in the presence of electrolyte. The structural changes in both cathode materials with the temperature rise follow different trends in the absence and presence of electrolyte between 25 and 600 °C. Phase transitions are comparatively simple in the absence of electrolyte, the fully charged lithium rich cathode material demonstrates better thermal stability by maintaining its phase till 379 °C, and afterwards spinel structure is formed. In the presence of electrolyte, however, the spinel structure appears at 207 °C, subsequently it transforms to rock salt type cubic phase at 425 °C with additional metallic, metal fluoride, and metal carbonate phases.

Lithium-rich layered transition metal oxide positive electrodes offer access to anion redox at high potentials, thereby promising high energy densities for lithium-ion batteries. However, anion redox is also associated with several unfavorable electrochemical properties, such as open-circuit voltage hysteresis. Here we reveal that in Li1.17–xNi0.21Co0.08Mn0.54O2, these properties arise from a strong coupling between anion redox and cation migration. We combine various X-ray spectroscopic, microscopic, and structural probes to show that partially reversible transition metal migration decreases the potential of the bulk oxygen redox couple by > 1 V, leading to a reordering in the anionic and cationic redox potentials during cycling. First principles calculations show that this is due to the drastic change in the local oxygen coordination environments associated with the transition metal migration. We propose that this mechanism is involved in stabilizing the oxygen redox couple, which we observe spectroscopically to persist for 500 charge/discharge cycles., Lithium ion battery electrodes employing anion redox exhibit high energy densities but suffer from poor cyclability. Here the authors reveal that the voltage of anion redox is strongly affected by structural changes that occur during battery cycling, explaining its unique electrochemical properties.

The solvent evaporation method on the structural changes and surface chemistry of the cathode and the effect of electrochemical performance of Li1.0Ni0.8Co0.15Mn0.05O2 (NCM) has been investigated. After dissolving of Li residuals using minimum content of solvent in order to minimize the damage of pristine material and the evaporation time, the solvent was evaporated without filtering and remaining powder was re-heated at 700 °C in oxygen environment. Two kinds of solvent, de-ionized water and diluted nitric acid, were used as a solvent. The almost 40% of Li residuals were removed using solvent evaporation method. The NCM sample after solvent evaporation process exhibited an increase in the initial capacity (214.3 mAh/g) compared to the pristine sample (207.4 mAh/g) at 0.1C because of enhancement of electric conductivity caused by decline of Li residuals. The capacity retention of NCM sample after solvent evaporation process (96.0% at the 50th cycle) was also improved compared to that of the pristine NCM sample (90.6% at the 50th cycle). The uniform Li residual layer after solvent treated and heat treatment acted like a coating layer, leading to enhance the cycle performance. The NCM sample using diluted nitric acid showed better performance than that using de-ionized water.

Hexanoic acid can be used for diverse industrial applications and is a precursor for fine chemistry. Although some natural microorganisms have been screened and evolved to produce hexanoic acid, the construction of an engineered biosynthetic pathway for producing hexanoic acid in yeast has not been reported. Here we constructed hexanoic acid pathways in Kluyveromyces marxianus by integrating 5 combinations of seven genes (AtoB, BktB, Crt, Hbd, MCT1, Ter, and TES1), by which random chromosomal sites of the strain are overwritten by the new genes from bacteria and yeast. One recombinant strain, H4A, which contained AtoB, BktB, Crt, Hbd, and Ter, produced 154 mg/L of hexanoic acid from galactose as the sole substrate. However, the hexanoic acid produced by the H4A strain was re-assimilated during the fermentation due to the reverse activity of AtoB, which condenses two acetyl-CoAs into a single acetoacetyl-CoA. This product instability could be overcome by the replacement of AtoB with a malonyl CoA-acyl carrier protein transacylase (MCT1) from Saccharomyces cerevisiae. Our results suggest that Mct1 provides a slow but stable acetyl-CoA chain elongation pathway, whereas the AtoB-mediated route is fast but unstable. In conclusion, hexanoic acid was produced for the first time in yeast by the construction of chain elongation pathways comprising 5–7 genes in K. marxianus.

Electrochemically active Li 2 MnO 3 nanoparticle dispersed on carbon nanotube (CNT) network has been successfully synthesized by microwave-assisted hydrothermal (MAH) process. To the best of our knowledge, this is the first report showing the formation of Li 2 MnO 3 nanoparticle on CNT network using MnO 2 -coated CNT composite. Appearance of superlattice peak in X-ray diffraction (XRD) pattern and Raman-active modes near the lower wavelength region of Raman spectra reveals the structure transition from spinel LiMn 2 O 4 to layered-type Li 2 MnO 3 phase. The X-ray absorption near edge spectra (XANES) shows increase in average oxidation state of Mn ion from 3.5+ to 4+, and Mn–O and Mn–Mn peak intensity variations observed from extended X-ray absorption fine structure (EXAFS) are well evidenced for the formation of ordered Li 2 MnO 3 structure. Electrochemical performance of Li 2 MnO 3 nanocomposite electrode material prepared from higher LiOH concentration shows much higher capacity than spinel component alone. This synthetic strategy opens a new way for effective synthesis of electrochemically active Li 2 MnO 3 on CNT network, making it suitable for advanced lithium ion battery.

We report a transmittance controllable electrochromic color filter (TCECF) by incorporating new electrochromic leuco dyes and their optimized composition. Each primary color red (R), green (G), and blue (B) electrochromic filter has an excellent transmittance of more than 84% at 650 nm, 540 nm, 450 nm, and the color coordinates are controllable from white (0.332, 0.347) to deep-red (0.621, 0.344), deep-green (0.327, 0.646), and deep-blue (0.179, 0.085), respectively. Also, each TCECF has good coloration efficiencies of 188.7 cm2 C−1 (R), 189.3 cm2 C−1 (G), and 147.8 cm2 C−1 (B) with high optical density change. A full color producible electrochromic color filter (ECF) is designed and fabricated by integrating primary RGB color filters with a refractive index matching adhesive layer. The fabricated three-stack full color producible ECF enables high transmittance of about 61% for clear white light extraction, and it can produce various colors including RGB. This TCECF technology will be very useful for high light out-coupling electro-optical applications, such as smart lighting, smart window, and display.

Carbon serves as one of the best coating materials for the cathode in lithium ion batteries. This is because it can solve two main problems, which are surface deterioration and poor electrical conductivity. However, the conventional carbon coating procedures and, chemical carbonization processes, are especially difficult to implement for the oxide cathode, which could thereby deteriorate the oxide structure. We prepared a new dry 100 nm-thick homogeneous multi-walled carbon nanotube (MWCNT) coating on the high-capacity oxide cathode material, Li1.17Ni0.17Co0.1Mn0.56O2, by applying shear stress without breaking down the crystal structure or morphology of the cathode. The electronic conductivity of the carbon composite with the coated sample is 170 mS cm−1, which is over 40 times as much as the conductivity of the pristine cathode containing the same amount of carbon. In addition, at a high current condition of 2450 mA g−1, a specific capacity of 103 mA h g−1 is observed even with 3 percent of the carbon (in weight) constituting the coated MWCNT. The unconventionally improved performances are explained by the suppression of the electronic resistance and surface charge transfer resistance by electrochemical analyses.

1) Konkuk UniversityAbstract : Integrated aircraft synthesis process for rapid analysis and design is described in this paper. Data flow between different analysis fields is described in details. All the data are divided into several groups according to importance and source of the data. Analysis of design requirements and certification regulations is carried out to determine baseline configuration of an aircraft. Overall design process can be divided into initial sizing, conceptual and preliminary design phases. Basic data for conceptual design are obtained from initial sizing, CAD and geometry analysis. Basic data are required input for weight, aerodynamics and propulsion analyses. Results of this analysis are used for stability and control, performance, mission, and load analysis. Feasibility of design is verified based on analysis results of each discipline. Design optimization that involves integrated process for aircraft analysis is performed to determine optimum configuration of an aircraft on a conceptual design stage. The process presented in this paper was verified to be used for light aircraft design.Key Words : Aircraft design synthesis, Design requirements, Initial Sizing, CADIS-SA, Very Light Aircraft !" # $ % & &$ $" # '!&$ $ ( $ $ # ! ) *+ $ !$ $ , # , $ $

Quorum sensing is a cell-to-cell communication system known to control many bacterial processes. In the present study, the functions of quorum sensing in the pathogenesis of Vibrio vulnificus , a food-borne pathogen, were assessed by evaluating the virulence of a mutant deficient in SmcR, a quorum-sensing regulator and homologue of LuxR. When biofilms were used as an inoculum, the smcR mutant was impaired in virulence and colonization capacity in the infection of mice. The lack of SmcR also resulted in decreased histopathological damage in mouse jejunum tissue. These results indicated that SmcR is essential for V. vulnificus pathogenesis. Moreover, the smcR mutant exhibited significantly reduced biofilm detachment. Upon exposure to INT-407 host cells, the wild type, but not the smcR mutant, revealed accelerated biofilm detachment. The INT-407 cells increased smcR expression by activating the expression of LuxS, an autoinducer-2 synthase, indicating that host cells manipulate the cellular level of SmcR through the quorum-sensing signaling of V. vulnificus . A whole-genome microarray analysis revealed that the genes primarily involved in biofilm detachment and formation are up- and downregulated by SmcR, respectively. Among the SmcR-regulated genes, vvpE encoding an elastolytic protease was the most upregulated, and the purified VvpE appeared to dissolve established biofilms directly in a concentration-dependent manner in vitro . These results suggest that the host cell-induced SmcR enhances the detachment of V. vulnificus biofilms entering the host intestine and thereby may promote the dispersal of the pathogen to new colonization loci, which is crucial for pathogenesis.

Small regulatory RNAs (sRNAs) regulate gene expression in bacteria. We designed synthetic sRNAs to identify and modulate the expression of target genes for metabolic engineering in Escherichia coli. Using synthetic sRNAs for the combinatorial knockdown of four candidate genes in 14 different strains, we isolated an engineered E. coli strain (tyrR- and csrA-repressed S17-1) capable of producing 2 g per liter of tyrosine. Using a library of 130 synthetic sRNAs, we also identified chromosomal gene targets that enabled substantial increases in cadaverine production. Repression of murE led to a 55% increase in cadaverine production compared to the reported engineered strain (XQ56 harboring the plasmid p15CadA). The design principles and the engineering strategy using synthetic sRNAs reported here are generalizable to other bacteria and applicable in developing superior producer strains. The ability to fine-tune target genes with designed sRNAs provides substantial advantages over gene-knockout strategies and other large-scale target identification strategies owing to its easy implementation, ability to modulate chromosomal gene expression without modifying those genes and because it does not require construction of strain libraries.

The solvent evaporation method on the structural changes and surface chemistry of the cathode and the effect of electrochemical performance of Li1.0Ni0.8Co0.15Mn0.05O2 (NCM) has been investigated. After dissolving of Li residuals using minimum content of solvent in order to minimize the damage of pristine material and the evaporation time, the solvent was evaporated without filtering and remaining powder was re-heated at 700 °C in oxygen environment. Two kinds of solvent, de-ionized water and diluted nitric acid, were used as a solvent. The almost 40% of Li residuals were removed using solvent evaporation method. The NCM sample after solvent evaporation process exhibited an increase in the initial capacity (214.3 mAh/g) compared to the pristine sample (207.4 mAh/g) at 0.1C because of enhancement of electric conductivity caused by decline of Li residuals. The capacity retention of NCM sample after solvent evaporation process (96.0% at the 50th cycle) was also improved compared to that of the pristine NCM sample (90.6% at the 50th cycle). The uniform Li residual layer after solvent treated and heat treatment acted like a coating layer, leading to enhance the cycle performance. The NCM sample using diluted nitric acid showed better performance than that using de-ionized water.

The second messenger nucleotide cyclic dimeric guanosine monophosphate (c-di-GMP) governs many cellular processes in the facultative human pathogen Vibrio cholerae. This organism copes with changing environmental conditions in aquatic environments and during transitions to and from human hosts. Modulation of c-di-GMP allows V. cholerae to shift between motile and sessile stages of life, thus allowing adaptation to stressors and environmental conditions during its transmission cycle. The V. cholerae genome encodes a large set of proteins predicted to degrade and produce c-di-GMP. A subset of these enzymes has been demonstrated to control cellular processes – particularly motility, biofilm formation, and virulence – through transcriptional, post-transcriptional, and translational mechanisms. Recent studies have identified and characterized enzymes that modulate or sense c-di-GMP levels and have lead towards mechanistic understanding of c-di-GMP regulatory circuits in V. cholerae.

The real time detection of quantitative oxygen release from the cathode is performed by in-situ Gas Chromatography as a tool to not only determine the amount of oxygen release from a lithium-ion cell but also to address the safety concerns. This in-situ gas chromatography technique monitoring the gas evolution during electrochemical reaction presents opportunities to clearly understand the effect of surface modification and predict on the cathode stability. The oxide cathode, 0.5Li2MnO3∙0.5LiNi0.4Co0.2Mn0.4O2, surface modified by amorphous cobalt-phosphate nanoparticles (a-CoPO4) is prepared by a simple co-precipitation reaction followed by a mild heat treatment. The presence of a 40 nm thick a-CoPO4 coating layer wrapping the oxide powders is confirmed by electron microscopy. The electrochemical measurements reveal that the a-CoPO4 coated overlithiated layered oxide cathode shows better performances than the pristine counterpart. The enhanced performance of the surface modified oxide is attributed to the uniformly coated Co-P-O layer facilitating the suppression of O2 evolution and offering potential lithium host sites. Further, the formation of a stable SEI layer protecting electrolyte decomposition also contributes to enhanced stabilities with lesser voltage decay. The in-situ gas chromatography technique to study electrode safety offers opportunities to investigate the safety issues of a variety of nanostructured electrodes.

Failure mechanisms involved in the high-voltage LiNi 0.5 Mn 1.5 O 4 electrode are studied at an elevated temperature (60 °C). At ambient temperature (25 °C), this oxygen-deficient spinel-structured electrode shows a reasonable cycle performance, but a rapid capacity decay after 40 cycles at 60 °C. An increase of electrode polarization and formation of electrically isolated active material, both of which become prominent from the 40th cycle, suggest that the electrode failure is mainly caused by the breakdown of electrically conductive network that is made between the active material, carbon and current collector in the composite electrode. The post-mortem electron microscope study reveals a crack formation at the electrode layer/aluminum current collector interface as well as inside the composite electrode layer, which can account for the electrode polarization and electrical isolation. The failure can, however, be mitigated by increasing the load of conductive carbon or polymeric binder, and also by using an etched aluminum foil as the current collector. All these countermeasures seem to be beneficial to reinforce the electrically conductive network.

There is the uncertain period of the construction in case of the products meeting the quality standard of KS M 6080, the quality is degraded because of the abrasive loss of the paint caused by vehicle tires as the traffic amount increases and of the loss and detachment of the glass beads providing the retroreflective function. The abrupt degradation of visibility causes the high frequency of traffic accidents at night and increases the traffic accident rate. Additional supplementary construction induces the direct material and construction costs. As the more cost induction effect than the direct cost, the traffic jam caused by the additional construction increases the indirect social costs such as time cost and vehicle cost. Hence, the study is concerned with performing the abrasion resistance test based on the EN 1436 standard to check and improve the quality of various road marking materials resulting in improving the durability of road marking materials. However, even though the difference in the durability lifetime of resins(binders) is bibliographically or theoretically clear, there was no difference in the durability lifetime (retroreflectivity aspect) of the road marking paint using these binders. The reason is that the bonding of beads was very insufficient or that the cross density caused by crack or freshness was low. Moreover, the measured wet retroreflectivity was distributed as the Rw3 or higher class in average on the basis of EN 1436 but was very insufficient on the basis of the minimum wet threshold retroreflectivity with 100mcd/() managed overseas.

Sangsin Brake*School of Mechanical Engineering, Yeungnam University(Received April 15, 2011; Revised June 5, 2011; Accepted June 15, 2011)Abstract − Yaw brakes are used in wind turbines to control the orientation of blades to be perpendicular to thewind. These devices are very important machine elements because they are closely related to the overall effi-ciency of wind turbines. One unit of yaw brakes is composed of a friction pad and a caliper. In this study, a tan-gential force between the friction pad and the disk is calculated when the brake is acting in 750 kW wind turbine.Then, stress distribution and the deformation of the caliper are calculated using a finite element analysis. Anexperimental equipment is also developed to verify the exactness of calculated results. The analytical and exper-imental results are presented and discussed.Keywords − wind turbine(풍력발전기), brake(브레이크), yaw system(요 시스템), structural analysis(구조해석)

We report the transfer printing of GaN-based microscale vertical-type light-emitting diodes (μ-VLEDs) using a functional layer and a biomimetic stamp. An oxide-based functional layer is inserted onto the structure of a μ-VLED and used to separate the chip from the μ-VLED wafer by absorbing the pulse of a UV pulse laser during pick-up of the transfer printing process. Polydimethylsiloxane (PDMS)-based biomimetic stamps have been fabricated to mimic the gecko lizard cilia for improved adhesion and repeatability. The biomimetic stamp has an adhesion force of 25.6 N/cm2, which is 12 times the adhesion of a flat stamp; an adhesion force of 10 N/cm2 or more was maintained after 100,000 repeated adhesion tests. A flexible 10 × 10 prototype array on a polyimide substrate was fabricated, and its bending test results indicated that the strain effect on the forward voltage and the output power was less than 1%. The stable bending test results of the prototype indicate that μ-VLEDs using biomimetic stamps allow the necessary stability for practical transfer printing.

Sucrose is one of the most promising carbon sources for industrial fermentation. To achieve sucrose catabolism, the sucrose utilization operons have been introduced into microorganisms that are not able to utilize sucrose. However, the rates of growth and sucrose uptake of these engineered strains were relatively low to be successfully employed for industrial applications. Here, we report a practical example of developing sucrose-utilizing microorganisms using Escherichia coli K-12 as a model system. The sucrose utilizing ability was acquired by introducing only β-fructofuranosidase from three different sucrose-utilizing organisms (Mannheimia succiniciproducens, E. coli W, and Bacillus subtilis). Among them, the M. succiniciproducens β-fructofuranosidase was found to be the most effective for sucrose utilization. Analyses of the underlying mechanism revealed that sucrose was hydrolyzed into glucose and fructose in the extracellular space and both liberated hexoses could be transported by their respective uptake systems in E. coli K-12. To prove that this system can also be applied for the production of useful metabolites, the M. succiniciproducens β-fructofuranosidase was introduced into the engineered L-threonine production strain of E. coli K-12. This recombinant strain was able to produce 51.1 g/L L-threonine by fed-batch culture, resulting in an overall yield of 0.284 g L-threonine per g sucrose. This simple approach to make E. coli K-12 to acquire sucrose-utilizing ability and its successful biotechnological application can be employed to develop sustainable bioprocesses using renewable biomass.

Transparent organic light emitting diodes (TOLED) have widespread applications in the next-generation display devices particularly in the large size transparent window and interactive displays. Herein, we report high performance and stable attractive smart window displays using facile process. Advanced smart window display is realized by integrating the high performance light blocking screen and highly transparent white OLED panel. The full smart window display reveals a maximum transmittance as high as 64.2% at the wavelength of 600 nm and extremely good along with tunable ambient contrast ratio (171.94:1) compared to that of normal TOLED (4.54:1). Furthermore, the performance decisive light blocking screen has demonstrated an excellent optical and electrical characteristics such as i) high transmittance (85.56% at 562nm) at light-penetrating state, ii) superior absorbance (2.30 at 562nm) in light interrupting mode, iii) high optical contrast (85.50 at 562 nm), iv) high optical stability for more than 25,000 cycle of driving, v) fast switching time of 1.9 sec, and vi) low driving voltage of 1.7 V. The experimental results of smart window display are also validated using optical simulation. The proposed smart window display technology allows us to adjust the intensity of daylight entering the system quickly and conveniently.