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.

Thermoelectric properties of Gd, Y co-doped Ca3Co4O9+δ

H.Q. Liu,X.B. Zhao,T.J. Zhu,Y. Song,F.P. Wang 한국물리학회 2009 Current Applied Physics Vol.9 No.3

The Ca3-x-yGdxYyCo4O9+δ precursor powders were synthesized by the polyacrylamide gel method. The powders were sintered by the spark plasma sintering (SPS). The DTA analysis showed that the synthesis temperature of Ca3Co4O9+δ was about 933 K, which is lower than that of the conventional citric acid method. The resistivities, the Seebeck coefficients and the thermal conductivities of the samples were measured from room temperature to 973 K. The Seebeck coefficients and the resistivities of the doped samples were remarkably enhanced due to the decrease of the carrier concentration, whereas the thermal conductivities of them were decreased due to the impurity scattering effect. The maximal ZT value of 0.26 was obtained at 973 K for Ca2.7 Gd0.15 Y0.15Co4O9+δ. The Ca3-x-yGdxYyCo4O9+δ precursor powders were synthesized by the polyacrylamide gel method. The powders were sintered by the spark plasma sintering (SPS). The DTA analysis showed that the synthesis temperature of Ca3Co4O9+δ was about 933 K, which is lower than that of the conventional citric acid method. The resistivities, the Seebeck coefficients and the thermal conductivities of the samples were measured from room temperature to 973 K. The Seebeck coefficients and the resistivities of the doped samples were remarkably enhanced due to the decrease of the carrier concentration, whereas the thermal conductivities of them were decreased due to the impurity scattering effect. The maximal ZT value of 0.26 was obtained at 973 K for Ca2.7 Gd0.15 Y0.15Co4O9+δ.

Emergence and Persistence of NS5A and NS3 Resistance-Associated Substitutions in HCV Genotype 1b Patients Treated with Daclatasvir and Asunaprevir

( F. Mcphee ),( D. Hernandez ),( N. Zhou ),( F. Yu ),( B. Kienzle ),( Y. Zhao ),( M. Linaberry ),( S. Noviello ),( M. L. Yu ),( S. H. Ahn ),( Y. Karino ),( K. Chayama ),( H. Kumada ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: A pooled analysis of emergent RAS was performed in HCV genotype (GT-)1b-infected patients receiving daclatasvir and asunaprevir (DCV+ASV) and the persistence of DCV- and ASV-resistant substitutions through ≥post-treatment Week (PTWK)192 was assessed to understand the RAS profile and help guide potential retreatment options. Methods: HCV GT-1b-infected patients without a sustained virologic response (SVR) and with HCV RNA ≥1000 IU/mL on or after DCV+ASV treatment were included from 5 Phase 2 and 3 studies. Baseline and post-baseline plasma samples were sequenced at a sensitivity cut-off ł20%. To determine the persistence of emergent RAS, samples at the end of study (up to PTWK48) and/or from a 3-year long-term follow-up rollover study were sequenced (sensitivity cut-off ≥20%, and ≥1% for select samples). Results: 152 DCV+ASV-treated patients without SVR met the resistance testing criteria: 89% (136/152) had NS5A and 95% (145/152) had NS3 sequences at both baseline and virologic failure (VF). NS5A and NS3 RAS emerged in 99% (134/136) and 89% (129/145), respectively, at VF (Table). Overall, 93% (142/152) of patients with VF had both NS5A and NS3 sequence data at failure, of which 77% (109/142) had RAS at L31, Y93 and D168. Emergent NS5A RAS persisted at PTWK96 (92%;24/26) and ≥PTWK192 (100;7/7compared with 22% (6/27) and 14% (1/7), respectively, for emergent NS3 RAS. Replacement of emergent NS5A and NS3 RAS observed at VF occurred in 8% (2/26) of NS5A and 74% (17/23) of NS3 sequences at PTWK96 and in 0% (0/7) of NS5A and 86% (6/7) of NS3 sequences at ≥PTWK192. Conclusions: NS5A and NS3 RAS emerged in most patients treated with DCV+ASV who experienced VF, and NS5A RAS persisted post-treatment. Therapy options for DCV+ASV treatment failures may depend on the timing of retreatment: an NS3 inhibitor-containing regimen may be possible if NS3 RAS are no longer observed, while regimens not impacted by the NS5A-L31+Y93 and NS3-D168 RAS combination would offer an immediate alternative.

Separation dynamics of hydrogen isotope gas in mesoporous and microporous adsorbent beds at 77 K: SBA-15 and zeolites 5A, Y, 10X

Chu, X.Z.,Cheng, Z.P.,Xiang, X.X.,Xu, J.M.,Zhao, Y.J.,Zhang, W.G.,Lv, J.S.,Zhou, Y.P.,Zhou, L.,Moon, D.K.,Lee, C.H. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.9

The separation of a hydrogen isotope mixture on porous materials was studied using equilibrium and breakthrough experiments. The adsorption equilibria of H<SUB>2</SUB> and D<SUB>2</SUB> on SBA-15 with mesopores and molecular sieves 5A, Y, and 10X with micropores were measured at 77 K using the volumetric method. The breakthrough experiments of a H<SUB>2</SUB> and D<SUB>2</SUB> mixture in each adsorbent bed were carried out at various conditions of flow rate and pressure. The equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> on mesoporous molecular sieves was larger than the ratio on microporous molecular sieves (SBA-15 > 10X > Y > 5A), but the difference among the adsorbents decreased with increases in pressure. On the other hand, the order of breakthrough separation factor showed the opposite result (SBA-15 < 10X < Y < 5A). The breakthrough separation factors for zeolite 10X was approximately equal to the equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> at the corresponding partial pressures, whereas zeolites 5A and Y showed higher breakthrough separation factors than their equilibrium ratios. In SBA-15, the separation factors from breakthrough results were even smaller than the corresponding equilibrium ratio. In the microporous adsorbent with a limited pore size (zeolite 5A in the study), the diffusion mechanism contributed to the separation of hydrogen isotope gases as one of key factors.

Effect of dietary levan fructan supplementation on growth performance, meat quality, relative organ weight, cecal microflora, and excreta noxious gas emission in broilers

Zhao, P. Y.,Wang, J. P.,Kim, I. H. American Society of Animal Science 2013 Journal of Animal Science Vol.91 No.11

<P>A total of 720 1-d-old male Ross broilers (BW of 48.0 ± 0.3 g) were used to evaluate the effects of dietary levan fructan supplementation on growth performance, meat quality, relative organ weight, cecal microflora, and excreta noxious gas emission in broilers. This experiment lasted 31 d. Broilers were randomly allotted to 1 of 3 dietary treatments: 1) CON, basal diet, 2) CON + 0.25% fructan (FC1), and 3) CON + 0.50% fructan (FC2). Each treatment contained 16 pens with 15 chicks per pen. Broilers on levan fructan supplementation treatments (FC1 + FC2) had a lower (<I>P</I> = 0.005 for d 15 to 31) ADFI and greater (<I>P</I> = 0.005 for d 15 to 31 and <I>P</I> = 0.022 for d 1 to 31) G:F than those on the CON. A decreased (<I>P</I> = 0.031) relative spleen weight was observed with levan fructan supplementation treatments compared with the CON. Cecal <I>E. coli</I> and <I>C. perfringens</I> concentrations in levan fructan treatments were decreased, while cecal <I>Lactobacillus</I>, as well as <I>Bifidobacteria</I>, concentrations in levan fructan treatments were increased compared with the CON. However, excreta NH<SUB>3</SUB> concentrations were decreased (<I>P</I> = 0.013) in levan fructan treatments compared with the CON. In conclusion, fructan supplementation improved later stage growth performance, increased cecal <I>Lactobacillus</I> and <I>Bifidobacteria</I> concentrations, and decreased cecal <I>E. coli</I> and <I>C. perfringens</I> concentrations, as well as excreta NH<SUB>3</SUB> concentrations, in broilers.</P>

On the nanomechanical characteristics of thermally-treated alloy 690: Grain boundaries versus grain interior

Zhao, Y.,Choi, I.C.,Kim, Y.J.,Jang, J.i. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.582 No.-

Alloy 690 has been widely used as steam generator tubing material in nuclear power plants owing to its excellent properties such as stress corrosion cracking resistance. In the present study, a series of nanoindentation experiments were conducted to explore the nanomechanical characteristics of the grain boundaries (GBs) and grain interior (GI) in the alloy 690 that were isothermally aged for four different times (for simulating the 20-80years operation under power plant condition). While the accelerated aging induced no pronounced degradation, the GB and GI show remarkable and reproducible differences in nanohardness (plastic flow), pop-in stress (yielding), and strain-rate sensitivity. The results are discussed in terms of dislocation activities in the various mechanisms of deformation behavior.

Evaluation of dietary fructan supplementation on growth performance, nutrient digestibility, meat quality, fecal microbial flora, and fecal noxious gas emission in finishing pigs

Zhao, P. Y.,Wang, J. P.,Kim, I. H. American Society of Animal Science 2013 Journal of Animal Science Vol.91 No.11

<P>This study was conducted to determine the effect of dietary fructan supplementation on growth performance, nutrient digestibility, meat quality, fecal microbial flora, and fecal noxious gas emission in finishing pigs. A total of 96 finishing pigs [(Yorkshire × Landrace) × Duroc] with an average BW of 73.1 ± 2.5 kg were used in a 6-wk study. Pigs were randomly allotted to 1 of 3 dietary treatments: 1) CON, basal diet, 2) CON + 1% fructan (FC1), and 3) CON + 2% fructan (FC2) with 8 replicate pens per treatment and 2 barrows and 2 gilts per pen. During the overall study, pigs fed the fructan supplementation diets had a greater (<I>P</I> < 0.05) ADG, G:F, the apparent total tract digestibility (ATTD) of DM and GE than pigs fed the CON diet. The levels of fructan supplementation did not affect growth performance and ATTD of DM, N, and GE. Fecal <I>E. coli</I> concentrations in the fructan treatments were lower (<I>P</I> < 0.001), while fecal <I>Lactobacillus</I> concentrations in the fructan treatments were greater (<I>P</I> < 0.001) compared with the CON treatment. Fecal ammonia and hydrogen sulfide emissions were lower (<I>P</I> < 0.05) in d 3, 5, and 7 in the fructan treatments, and total mercaptans emission was lower (<I>P</I> < 0.05) on d 3 and 5 compared with the CON treatment. In conclusion, fructan supplementation improved growth performance and ATTD of DM and GE, improved the fecal microbial balance, and inhibited the fecal <I>E. coli</I>. Furthermore, fructan may decrease fecal noxious gas emissions by finishing pigs.</P>

Polaron Localization at Interfaces in High-Mobility Microcrystalline Conjugated Polymers

Zhao, N.,Noh, Y.-Y.,Chang, J.-F.,Heeney, M.,McCulloch, I.,Sirringhaus, H. WILEY-VCH Verlag 2009 ADVANCED MATERIALS Vol.21 No.37

<B>Graphic Abstract</B> <P>The charge-induced optical absorptions of two-dimensional polarons in semicrystalline, high-mobility conjugated polymers are investigated as a function of distance from an interface with polymer gate dielectrics of different dielectric constants. For high-k dielectrics, polarons in the accumulation layer at the interface are found to be more localized than those in the bulk. <img src='wiley_img/09359648-2009-21-37-ADMA200900326-content.gif' alt='wiley_img/09359648-2009-21-37-ADMA200900326-content'> </P>

Fracture toughness of Porcelain Enamel and Application to 4-point Bending test

Y. L. Zhao,Y. K. Son,D. C. Ko,B. Y. Yu,M. S. Park,B. M. Kim 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.10

The porcelain enamel coating is widely applied to home appliance, since it has many excellent properties including abrasion, chemical resistance, high hardness, brilliant colors and high temperature-proof. But during the usage, hairline cracks occur on enamel coating because of product deformation. The fracture toughness is used as a generic term for measurement of material resistance to extension of a crack. The purpose of this paper is to define the brittle cracking property of enamel coating by measuring the fracture toughness factor KIC in Vickers indentation test. Then the property is applied to 4-point bending simulation using FE-analysis to predict the crack. The validity of the FE-analysis is verified through real 4-point bending test, and the result from FE-analysis agreed well to real test.

Effects of Bacteriophage Supplementation on Egg Performance, Egg Quality, Excreta Microflora, and Moisture Content in Laying Hens

Zhao, P.Y.,Baek, H.Y.,Kim, I.H. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.7

An experiment was conducted to evaluate the effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. A total of 288 Hy-line brown commercial laying hens (36-wk-old) were randomly allotted to 4 treatments in this 6-wk trial and dietary treatments included: i) CON, basal diet; ii) T1, CON+0.020% bacteriophage; iii) T2, CON+0.035% bacteriophage; iv) T3, CON+0.050% bacteriophage. There were 6 replicates for each treatment with 6 adjacent cages (2 hens/cage). Laying hens in T2 and T3 treatments had higher (p<0.05) egg production than those in CON and T1 treatments during wk 0 to 3. In addition, egg production in T1, T2, and T3 treatments was increased (p<0.05) compared with that in CON treatment during wk 4 to 6. At wk 4 and 5, birds in T2 group had higher (p<0.05) HU than those in CON. In addition, at wk 5 and 6, HU in birds fed T1 and T3 diets was greater (p<0.05) than those fed CON diet. E. coli and Salmonella spp. concentrations in excreta were decreased (p<0.05) by T1, T2, and T3 treatments. However, egg weight, egg shell color, yolk height, yolk color unit, egg shell strength, egg shell thickness, egg gravity, and excreta moisture content were not influenced by dietary treatments during the entire experimental period. In conclusion, bacteriophage supplementation has beneficial effects on egg production, egg albumen, and excreta microflora concentration in laying hens.