Shoot organogenesis and somatic embryogenesis in leaf tissue of Pulsatilla tongkangensis Y.N. Lee & T.C. Lee

Zhao Xiao-mei,Lian Yu-ji,Jin Ze-lin,Zhang Xue-jie,Y Yan,Fan Shou-jin 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.4

Leaf material explants of Pulsatilla tongkangensis Y. N. Lee & T. C. Lee were used to regenerate plants of this endangered species by somatic embryogenesis and organogenesis from meristematic nodules, induced by MS medium supplemented with zeatin (Zn) and indole-3-acetic acid (IAA). Globular structures were induced on the surface of the explants after 2 weeks and after 6–7 weeks of culture, multiple shoots developed from the nodules. Morpho-histological analysis of light green globular, heart-shaped structures resembling somatic embryos revealed, however, that these were organogenic, with strongly vacuolated parenchymatous cells surrounded by a single layer of epithermal cells, and tracheid elements, but no root pole. Milky-white callus also developed around the nodules after 4–6 weeks. Morpho-histological analysis of the globular, heart-, and torpedo-shaped stages of regenerants present in this callus confirmed the development of somatic embryos in the milky-white structures, characterized by deeply staining, small cells with rich cytoplasm, very little vascular tissue in the developing embryos, and no vascular connection with the surrounding callus. The highest rooting frequency (93.33%) was achieved on MS medium containing 1.5 mg/l NAA. Plantlets were acclimatized and successfully transferred to pots. Our results provide a plant regeneration system with potential for germplasm conservation of endangered plants and the rapid propagation and molecular breeding of P. tongkangensis.

Thermal properties of Y(BH₄)₃ synthesized via two different methods

Park, K.,Lee, H.S.,Remhof, A.,Lee, Y.S.,Yan, Y.,Kim, M.Y.,Kim, S.J.,Zuttel, A.,Cho, Y.W. Pergamon Press ; Elsevier Science Ltd 2013 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.38 No.22

Y(BH<SUB>4</SUB>)<SUB>3</SUB> is one of the candidates for solid-state hydrogen storage, which contains 9.06 wt% of hydrogen. In this study, the thermal properties of Y(BH<SUB>4</SUB>)<SUB>3</SUB> synthesized via two different methods are extensively examined. One method relies on the solid-solid metathesis reaction between LiBH<SUB>4</SUB> and YCl<SUB>3</SUB>, and the other method is the gas-solid reaction between B<SUB>2</SUB>H<SUB>6</SUB> and YH<SUB>3</SUB>. The two samples are studied by differential scanning calorimetry, thermogravimetry, and X-ray diffraction. They exhibit distinctly different polymorphic phase transformation and melting. It turns out that the side product LiCl in the metathesis reaction, which has been regarded as being inert, shifts the melting point and promotes the formation of YB<SUB>4</SUB> during decomposition. Differential scanning calorimetry and in situ X-ray diffraction data indicate that the addition of LiBH<SUB>4</SUB> to Y(BH<SUB>4</SUB>)<SUB>3</SUB> induces co-melting as is found in the cases of LiBH<SUB>4</SUB>-Ca(BH<SUB>4</SUB>)<SUB>2</SUB> or LiBH<SUB>4</SUB>-Mg(BH<SUB>4</SUB>)<SUB>2</SUB>. Melt infiltration of Y(BH<SUB>4</SUB>)<SUB>3</SUB> into mesoporous carbon cage confirms such melting behavior.

Tin porphyrin immobilization significantly enhances visible-light-photosensitized degradation of Microcystins: Mechanistic implications

Yoo, H.Y.,Yan, S.,Ra, J.W.,Jeon, D.,Goh, B.,Kim, T.Y.,Mackeyev, Y.,Ahn, Y.Y.,Kim, H.J.,Wilson, L.J.,Alvarez, P.J.J.,Lee, Y.,Song, W.,Hong, S.W.,Kim, J.,Lee, J. Elsevier 2016 Applied catalysis. B, Environmental Vol.199 No.-

<P>This study demonstrates that tin porphyrin (SnP) loading on a silica substrate (SnP/silica) markedly accelerates the degradation of Microcystins (MCs) under visible light irradiation, despite a reduction of photosensitized singlet oxygen (O-1(2)) production. A comparative study using Rose Bengal, SnP, and C-60 aminofullerene suggested that the MC-RR decay rate was directly proportional to the photosensitizing activity for triplet state-induced oxidation, while it exhibited poor correlation to singlet oxygenation efficiency. This implies that electron transfer from MC to the triplet state of SnP (facilitated by favorable MC sorption on silica) contributes to the photosensitized MC oxidation. Experiments to examine sensitizers for the one-electron oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) showed the superiority of SnP/silica for photo-initiated electron transfer as a possible MC oxidation route. This was corroborated by the negligible effects of reagents that quench or facilitate singlet oxygenation (e.g., azide ion, D2O) on the MC-RR degradation rate. Despite MC-RR removal below detection levels, residual toxicity (indicated by a significant decrease in protein phosphatase inhibition activity) was observed. Tandem mass spectrometric analysis suggests that this residual toxicity may be ascribed to byproducts resulting from addition of a single oxygen atom to the Adda moiety. (C) 2016 Elsevier B.V. All rights reserved.</P>

Development of an Automatic Packer Using Vacuum Packaging and its Effects on the Rice Quality

Yan, T.Y.,Chung, J.H.,Rhee, C.O. Korean Society for Agricultural Machinery 2004 바이오시스템공학 Vol.29 No.2

본 연구에서는 배아미, 현미, 가능성쌀들 및 진공을 요하는 식품의 품질을 보존하기 위해서 연속식 자동진공포장기를 국내 최초로 개발하였다. 배아미의 진공포장 성공률은 92.6%이었고, 실패율 7.4%에서 진공포장기 자체에서 불완전 테이핑의 밀봉작업으로 진공이 서서히 풀리는 경우가 5.5%, 그리고 진공하기 전 자동비닐포장기에서 포장시 봉지 윗부분 밀봉이 불완전해 1.9%가 진공이 풀렸다. 이에 개발한 자동진공포장기의 진공포장성공률은 약 94.5%수준이었다. 진공포장기로 진공시간에 따른 진공압력을 측정하였고, 배아미 2, 3, 5 kg를 진공포장하는데 소요되는 시간은 각각 6, 8, 11초이었다. 진공포장으로 처리한 배아미와 진공포장 처리하지 않은 배아미를 각각 3재월간 저장실험하여 백도, 함수율, 과산화물가, 산가를 저장기간별로 분석하였다. 그 결과, 백도는 진공처리가 2 감소, 비처리가 4 감소하였고, 함수율은 진공처리가 0.8%감소, 비처리가 1.3%감소, 과산화물가는 진공처리가 최대 1.89 meq/kg까지 서서히 증가하였고, 비처리가 3.45 meq/kg까지 급속히 증가하였다가 서서히 감소하였다. 산가 역시 진공처리가 최대 0.71 mg/g까지 서서히 증가하였고, 비처리의 경우는 0.98 mg/g까지 급속히 증가하였다. 그리고 현미의 진공포장에서도 산가 및 과산화물가 변화가 배아미 경우와 비슷하였다. 또한 진공포장 제품에 인위적으로 쌀벌레들을 넣은 경우 15일 지나면 산소부족으로 모두 사멸하였다. 따라서 개발한 진공포장기로 진공포장한 경우 배아미 및 현미의 품질을 잘 보존할 수 있었다.

Effects of acid vapour mediated oxidization on the electrochemical performance of thermally exfoliated graphene

Yan, Y.,Kuila, T.,Kim, N.H.,Lee, J.H. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.74 No.-

The surface modification of thermally exfoliated graphene (TEG) is an important technique for alteration of its hydrophobic nature and the resolution of its limited dispersibility. We have developed an easy acid-vapour-mediated method to functionalize the inert TEG surface with oxygen functional groups. The effects of oxygen functional groups on the capacitive performances of TEG were investigated with various reaction times. Ultraviolet-visible, Fourier transform infrared and Raman spectroscopy analyses demonstrated that the dispersibility of TEG was improved due to defect augmenting as the extent of oxidation progressed. Quantitative analyses of functional groups of the oxidized TEG samples (O-TEGs) were performed by thermogravimetric analysis and X-ray photoelectron spectroscopic studies. Physisorption surface analysis showed that the pore volumes of O-TEGs were greater than that of the pristine TEG, whereas the specific surface areas of O-TEGs were lower than that of pristine TEG. Electrochemical performances of the O-TEG samples were measured through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy analysis. A maximum specific capacitance of 175.2Fg<SUP>-1</SUP> was recorded at a current density of 1Ag<SUP>-1</SUP> for the O-TEG oxidized for 2h. Retention of specific capacitance for the sample was ~97% after 5000 charge-discharge cycles.

Nodeless superconductivity in the noncentrosymmetric superconductor BiPd

Yan, X B,Xu, Y,He, L P,Dong, J K,Cho, Hwanbeom,Peets, D C,Park, Je-Geun,Li, S Y IOP 2016 Superconductor science & technology Vol.29 No.6

<P>We report low-temperature thermal conductivity measurements on high-quality single crystalline <I>α</I>-BiPd, a noncentrosymmetric superconductor with <I>T</I> <SUB>c</SUB>?≃?3.8 K. In zero magnetic field, the residual linear term <I>κ</I> <SUB>0</SUB>/<I>T</I> is absent, indicating a full gap and suggesting dominant singlet pairing. Consistent with this picture, <I>κ</I> <SUB>0</SUB>(<I>H</I>)/<I>T</I> shows weak field dependence in low field, but grows relatively fast in fields above 0.03 T (≃1/5<I>H</I> <SUB>c2</SUB>). Implications for the material’s disputed high-field behavior are discussed, and constraints are placed on the previously proposed scenarios.</P>

N-doped carbon layer coated thermally exfoliated graphene and its capacitive behavior in redox active electrolyte

Yan, Y.,Kuila, T.,Kim, N.H.,Lee, S.H.,Lee, J.H. Pergamon Press ; Elsevier Science Ltd 2015 Carbon Vol.85 No.-

A nitrogen-doped carbon layer coated thermally exfoliated graphene (NC-TEG) is prepared by in-situ polymerization of p-phenylene diamine (PD) with thermally exfoliated graphene (TEG) and subsequent high temperature pyrolysis (600<SUP>o</SUP>C for 1h in argon gas environment). Fourier transfer infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy confirm the formation of poly-(p-phenylene diamine) layers on the TEG surfaces with a nitrogen doping level of ~6.1%. Physisorption analysis indicates that NC-TEG not only has the enlarged surface area, but also forms hierarchical three dimensional structures with several micro and meso-pores compared to pristine TEG. Due to the synergic effect of nitrogen atoms in the carbon structures and augmented surface area, the capacitance measured from cyclic voltammetry and galvanic charge-discharge increases to 282.5Fg<SUP>-1</SUP> from the 95.1Fg<SUP>-1</SUP> of TEG. Moreover, the PD monomer acts as a reversible faradaic agent. The capacitive performance of the NC-TEG electrode is investigated in different mixed electrolytes. The specific capacitance is significantly increased to 635.6Fg<SUP>-1</SUP> in a mixed electrolyte of 0.025M PD and 2M KOH. After 10,000 cycles, the capacitive retention shows remarkable stability as high as 87.4%.

Experimental Study of the Runaway Current in the J-TEXT Tokamak

Y. H. Luo,Z. Y. Chen,X. Q. Zhang,D. W. Huang,W. Jin,Y. H. Huang,Y. Tang,J. C. Li,R. H. Tong,W. Yan,G. Zhuang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.3

Major plasma disruptions in tokamaks often generate runaway currents, which contain electronswith energies of several tens of megaelectron-volts (MeV). These currents can cause substantialdamage when control is lost and the current hits the limiters or the vessel wall. The interactionbetween the runaway electrons and the impurities inside the plasma results in soft X-ray emission,which can provide detailed information about the runaway generation process and the confinementof runaway electrons. A vertical soft X-ray array at the top of Joint Texas Experimental Tokamak(J-TEXT) was used to study the runaway beams resulting from major disruptions. Runawayelectron production and confinement of runaway current were observed by using soft X-ray images.

Preparation of Nd-doped manganese-zinc-ferrite/polyaniline composite materials

Yan, S. F.,Xie, Y.,Liu, J. M.,Pan, J. F.,Yu, Y. F.,Shi, L.,Zhang, K.,Lai, Q.,Liu, F. M.,Gao, Y. H.,Ling, Y. Informa UK (TaylorFrancis) 2014 Materials research innovations Vol.18 No.2

Chemical Constituents of the Aerial Parts of Artemisia iwayomogi

Yan, X. T.,Ding, Y.,Li, W.,Sun, Y. N.,Kim, Y. H. Springer Science + Business Media 2015 Chemistry of natural compounds Vol.51 No.6