Combining metabolic engineering and biocompatible chemistry for high-yield production of homo-diacetyl and homo-(S,S)-2,3-butanediol

Liu, J.,Chan, S.H.J.,Brock-Nannestad, T.,Chen, J.,Lee, S.Y.,Solem, C.,Jensen, P.R. Academic Press 2016 Metabolic engineering Vol.36 No.-

Biocompatible chemistry is gaining increasing attention because of its potential within biotechnology for expanding the repertoire of biological transformations carried out by enzymes. Here we demonstrate how biocompatible chemistry can be used for synthesizing valuable compounds as well as for linking metabolic pathways to achieve redox balance and rescued growth. By comprehensive rerouting of metabolism, activation of respiration, and finally metal ion catalysis, we successfully managed to convert the homolactic bacterium Lactococcus lactis into a homo-diacetyl producer with high titer (95mM or 8.2g/L) and high yield (87% of the theoretical maximum). Subsequently, the pathway was extended to (S,S)-2,3-butanediol (S-BDO) through efficiently linking two metabolic pathways via chemical catalysis. This resulted in efficient homo-S-BDO production with a titer of 74mM (6.7g/L) S-BDO and a yield of 82%. The diacetyl and S-BDO production rates and yields obtained are the highest ever reported, demonstrating the promising combination of metabolic engineering and biocompatible chemistry as well as the great potential of L. lactis as a new production platform.

3D yolk-shell NiGa2S4 microspheres confined with nanosheets for high performance supercapacitors

Liu, S.,Kim, K.,Yun, J.,Kundu, A.,Sankar, K. V.,Patil, U.,Ray, C.,ChanJun, S. Royal Society of Chemistry 2017 Journal of Materials Chemistry A Vol.5 No.13

<P>Recent advances in the development of two-dimensional transition-metal chalcogenides (2D TMCs) have opened up new avenues for supercapacitor applications. However, they still suffer from limited specific capacitance and poor rate capability due to their poor interfacial properties and simple geometry. Here, we propose a facile strategy for the synthesis of yolk-shell NiGa2S4 microspheres comprising crumpled nanosheets supported on nickel foam. The robust structure not only highly facilitates the electron and charge transportation but also efficiently alleviates the volume expansion during redox reactions, contributing to excellent electrochemical behaviors in terms of specific capacitance and rate capability. Significantly, an asymmetric supercapacitor based on the prepared NiGa2S4 as the positive electrode and N, S-codoped graphene/Fe2O3 (N, S-G/Fe2O3) as the negative electrode delivers a high energy density of 43.6 W h kg(-1) at a power density of 961 W kg(-1) and retains an energy density of 22.2 W h kg(-1) even at 15 974 W kg(-1). These impressive results may provide a new perspective to develop high energy and power density storage systems for practical applications.</P>

<i>K</i>-mixing in the doubly mid-shell nuclide ¹⁷⁰Dy and the role of vibrational degeneracy

Sö,derströ,m, P.-A.,Walker, P.M.,Wu, J.,Liu, H.L.,Regan, P.H.,Watanabe, H.,Doornenbal, P.,Korkulu, Z.,Lee, P.,Liu, J.J.,Lorusso, G.,Nishimura, S.,Phong, V.H.,Sumikama, T.,Xu, F.R.,Yagi, A.,Zha North-Holland Pub. Co 2016 Physics letters. Section B Vol.762 No.-

<P><B>Abstract</B></P> <P>A detailed study of the structure of the doubly mid-shell nucleus Dy 104 1 66 170 has been carried out, following isomeric and <I>β</I> decay. We have measured the yrast band up to the spin-parity <SUP> J π </SUP> = <SUP> 6 + </SUP> state, the K = 2 <I>γ</I>-vibration band up to the <SUP> 5 + </SUP> state, a low-lying negative-parity band based on a <SUP> 2 − </SUP> state that could be a candidate for the lowest energy octupole vibration state within this nucleus, and a candidate for the <SUP> K π </SUP> = <SUP> 6 + </SUP> two quasi-particle isomer. This state was determined to have an excitation energy of 1643.91(23) keV and a half life of 0.99(4) μs, with a reduced hindrance for its decay to the ground-state band an order of magnitude lower than predicted by <SUB> N p </SUB> <SUB> N n </SUB> systematics. This is interpreted as being due to <I>γ</I>-vibrational mixing from a near degeneracy of the isomer and the <SUP> 6 + </SUP> state of the <I>γ</I> band. Furthermore, the parent nucleus <SUP>170</SUP>Tb has been determined to have a half-life of 0.91 ( − 13 + 18 ) s with a possible spin-parity of <SUP> 2 − </SUP> .</P>

Magnetically separable sulfur-doped SnFe₂O₄/graphene nanohybrids for effective photocatalytic purification of wastewater under visible light

Jia, Y.,Wu, C.,Lee, B.W.,Liu, C.,Kang, S.,Lee, T.,Park, Y.C.,Yoo, R.,Lee, W. Elsevier Scientific Pub. Co 2017 Journal of hazardous materials Vol.338 No.-

In this report, magnetically recoverable sulfur-doped SnFe<SUB>2</SUB>O<SUB>4</SUB>/graphene (S-SFO/GR) nanohybrids have been successfully developed via a facile solvothermal method. The characterizations on the structural, morphology, and optical properties of the nanohybrids indicate that S-SFO particles are successfully embedded on the GR nanosheets. The photocatalytic activity has been evaluated by photocatalytic degradation of chlorotetracycline under visible light irradiation. Among the composites with various mass ratios, the quasi-first-order rate constant of the nanohybrids formed with 9wt% S in SFO and 15wt% GR (9S-SFO/GR-15) can reach as high as 1.83min<SUP>-1</SUP>, which is much higher than that of SFO (0.68min<SUP>-1</SUP>) and SFO/GR (0.91min<SUP>-1</SUP>), confirming the important role of S and GR for the photocatalytic process. The combination of the three components of S, SFO, and GR has enhanced the visible light absorption capability and inhibited the recombination of photogenerated electron-hole. The 9S-SFO/GR-15 nanohybrids can be recovered easily by a magnet and reused for five times with remained photocatalytic efficiency about 70%. A possible catalytic mechanism explaining the efficient photocatalytic performances of the prepared nanohybrids has been proposed.

The Magnetoresistance in Iron-based Superconductors

B. Lv,R. B. Xie,S. L. Liu,G. J. Wu,H. M. Shao,X. S. Wu 한국자기학회 2011 Journal of Magnetics Vol.16 No.2

The phase transition of vortex matter from solid to liquid was studied in iron-based superconductors. Based on the traditional vortex glass theory, we have examined the magnetoresistivity data of iron-based superconductors using our extended thermal activation model: ρ(B,T) = ρ((T-Tg(B))/(Tc(0)-Tg(B)))<SUP>v(z-1)</SUP>. We predict that the magnetic field-dependent area S + S? which integrates ρ with T is proportional to B<SUP>β</SUP>, where β is the vortex glass transition exponent. From our calculation, the vortex glass transition exponent is 0.33, close to the exponent of area S?+ S is 0.31 in SmO0.9F0.1FeAs; the exponent of area S is 0.63, which is close to the irreversibility line exponent 2/3. Both of the results show the validity of our model. In addition, our model is shown to be effective in describing irreversibility behavior in layered superconductors.

SimulationX 기반 자동차 semi-active 현가장치의 모델 개발 및 특성 해석

정인태(I. T. Jeong),정동석(D. S. Jeong),정원식(W. S. Jeong),이성민(S. M. Lee),유보연(B. Y. Yoo),장대범(D. B. Jang),서영우(Y. W. Seo),한성민(S. M. Han),이석우(S. W. Lee),여현승(H. S. Yeo),류하오(Hao Liu) 유공압건설기계학회 2022 유공압건설기계학회 학술대회논문집 Vol.2022 No.12

The semi-active suspension system controls the damping force of the vehicle damper to simultaneously improve the steering stability (handling) and ride comfort of the vehicle. In order to improve the ride comfort of a passenger car, performance analysis is required through modeling and simulation adaptation of a semi-active suspension system. This study used SimulationX, a commercial multi-domain analysis S/W, and modeling about 1/4 car of the semi-active suspension system. The damping force was controlled through a given performance of the damper. The developed SimulationX-based semi-active suspension system model is prepared for future controller development research.

Effects of Dietary Energy Density on Growth, Carcass Quality and mRNA Expression of Fatty Acid Synthase and Hormone-sensitive Lipase in Finishing Pigs

Liu, Z.H.,Yang, F.Y.,Kong, L.J.,Lai, C.H.,Piao, X.S.,Gu, Y.H.,Ou, X.Q. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.10

A single factorial experiment was conducted to test the effects of three dietary levels of energy on mRNA expression of fatty acid synthase (FAS-mRNA) and hormone-sensitive lipase (HSL-mRNA) and their association with intramuscular fat in finishing pigs. 72 crossbred (Large $White{\times}Rongchang$) barrows with an average initial body weight of 20.71 (s.e. 0.1) kg, were randomly allotted to three dietary treatments (11.75, 13.05 and 14.36 MJ DE/kg) and fed until slaughtered at 100 or 101 kg. The diets were iso-nitrogenous and iso-essential amino acids. The growth performances including the duration of finishing were changed linearly (p<0.05) or quadratically (p<0.05) with increased dietary energy levels. The effects of dietary energy content on the percentage of external fat, intramuscular backfat and the fat thickness were linear (p<0.05). The content of dietary energy increased FAS-mRNA linearly or quadratically, while HSL-mRNA decreased linearly or quadratically in backfat and Longissmus dorsi muscle. Meanwhile, significant positive correlations (p<0.05) were found between energy level and intramuscular fat, FAS-mRNA or the ratio of FAS-mRNA to HSL-mRNA, between the ratio of FAS-mRNA to HSL-mRNA and intramuscular fat. However, the correlations between HSL mRNA and dietary energy or intramuscular fat were negative (p<0.05). The results indicated that dietary energy level regulates lipid accumulation, especially intramuscular fat, possibly by modulating the mRNA of FAS and HSL together rather than individually.

Effects of absorbents on growth performance, blood profiles and liver gene expression in broilers fed diets naturally contaminated with aflatoxin

Liu, J.B.,Yan, H.L.,Cao, S.C.,Hu, Y.D.,Zhang, H.F. Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.2

Objective: The study was conducted to evaluate the effects of the absorbent (a mixture of activated carbon and hydrated sodium calcium aluminosilicate) on growth performance, blood profiles and hepatic genes expression in broilers fed diets naturally contaminated with aflatoxin. Methods: A total of 1,200 one-day-old male chicks were randomly assigned to 6 treatments with 10 replicate cages per treatment. The dietary treatments were as follows: i) control (basal diets); ii) 50% contaminated corn; iii) 100% contaminated corn; iv) control+1% adsorbent; v) 50% contaminated corn+1% absorbent; vi) 100% contaminated corn+1% absorbent. Results: During d 1 to 21, feeding contaminated diets reduced (p<0.05) body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI), but increased (p<0.05) feed-to-gain ratio (F/G). The absorbent supplementation increased (p<0.05) BW, ADG, and ADFI. There were interactions (p<0.05) in BW, ADG, and ADFI between contaminated corn and absorbent. Overall, birds fed 100% contaminated diets had lower (p<0.05) final BW and ADG, but higher (p<0.05) F/G compared to those fed control diets. The absorbent addition increased (p<0.05) serum albumin concentration on d 14 and 28 and total protein (TP) level on d 28, decreased (p<0.05) alanine transaminase activity on d 14 and activities of aspartate aminotransferase and alkaline phosphatase on d 28. Feeding contaminated diets reduced (p<0.05) hepatic TP content on d 28 and 42. The contaminated diets upregulated (p<0.05) expression of interleukin-6, catalase (CAT), and superoxide dismutase (SOD), but downregulated (p<0.05) glutathione S-transferase (GST) expression in liver. The absorbent supplementation increased (p<0.05) interleukin-1β, CAT, SOD, cytochrome P450 1A1 and GST expression in liver. There were interactions (p<0.05) in the expression of hepatic CAT, SOD, and GST between contaminated corn and absorbent. Conclusion: The results suggest that the naturally aflatoxin-contaminated corn depressed growth performance, while the adsorbent could partially attenuate the adverse effects of aflatoxin on growth performance, blood profiles and hepatic genes expression in broilers.

Nanostructured nitrogen-doped mesoporous carbon derived from polyacrylonitrile for advanced lithium sulfur batteries

Liu, Y.,Zhao, X.,Chauhan, G.S.,Ahn, J.H. New York] ; North-Holland 2016 APPLIED SURFACE SCIENCE - Vol.380 No.-

Nitrogen doping in carbon matrix can effectively improve the wettability of electrolyte and increase electric conductivity of carbon by ensuring fast transfer of ions. We synthesized a series of nitrogen-doped mesoporous carbons (CPANs) via in situ polymerization of polyacrylonitrile (PAN) in SBA-15 template followed by carbonization at different temperatures. Carbonization results in the formation of ladder structure which enhances the stability of the matrix. In this study, CPAN-800, carbon matrix synthesized by the carbonization at 800<SUP>o</SUP>C, was found to possess many desirable properties such as high specific surface area and pore volume, moderate nitrogen content, and highly ordered mesoporous structure. Therefore, it was used to prepare S/CPAN-800 composite as cathode material in lithium sulfur (Li-S) batteries. The S/CPAN-800 composite was proved to be an excellent material for Li-S cells which delivered a high initial discharge capacity of 1585mAhg<SUP>-1</SUP> and enhanced capacity retention of 862mAhg<SUP>-1</SUP> at 0.1C after 100 cycles.

Selection and Isoenzyme Analysis of Plant Cell Lines for High Yields of Superoxide Dismutase

You, S. H 한국식물조직배양학회 1996 식물생명공학회지 Vol.23 No.2