1
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Wang Y, Yang SG, Li YX, Cao Y, Liu F, Zeng XB, Cseh L, Ungar G. Supertwisted Chiral Gyroid Mesophase in Chiral Rod-Like Compounds. Angew Chem Int Ed Engl 2024:e202403156. [PMID: 38566540 DOI: 10.1002/anie.202403156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024]
Abstract
Among the intriguing bicontinuous self-assembled structures, the gyroid cubic is the most ubiquitous. It is found in block and star polymers, surfactants with or without solvent, in thermotropic liquid crystals with end- or side-chains, and in biosystems providing structural color and modelling cell mitosis. It contains two interpenetrating networks of opposite chirality and is thus achiral if, as usual, the content of the two nets is the same. However, we now find that this is not the case for strongly chiral compounds. While achiral molecules follow the opposite twists of nets 1 and 2, molecules with a chiral center in their rod-like core fail to follow the 70° twist between junctions in net 2 and instead wind against it by -110° to still match the junction orientation. The metastable chiral gyroid is a high-entropy high-heat-capacity mesophase. The homochirality of its nets makes the CD signal of the thienofluorenone compounds close to that in the stable I23 phase with 3 isochiral nets.
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Affiliation(s)
- Yan Wang
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Shu-Gui Yang
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Ya-Xin Li
- School of Chemistry and Chemical Engineering, Henan University of Technology, 450001, Zhengzhou, China
| | - Yu Cao
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Feng Liu
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Xiang-Bing Zeng
- Department of Materials Science and Engineering, University of Sheffield, S1 3JD, Sheffield, UK
| | - Liliana Cseh
- Romanian Academy, Coriolan Dragulescu Institute of Chemistry, 300223, Timisoara, Romania
| | - Goran Ungar
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
- Department of Materials Science and Engineering, University of Sheffield, S1 3JD, Sheffield, UK
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2
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Cui J, Yang SG, Zhang R, Cao Y, Wang Y, Zeng X, Liu F, Ungar G. Continuous Spectrum of Morphologies and Phase Behavior across the Contact Zone from Poly(l-lactide) to Poly(d-lactide): Stereocomplex, Homocrystal, and Between. Macromolecules 2023; 56:8754-8766. [PMID: 38024153 PMCID: PMC10653275 DOI: 10.1021/acs.macromol.3c01815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023]
Abstract
The enantiomeric ratio is a key factor affecting the crystallization behavior and morphology of poly-l-lactide/poly-d-lactide (PLLA/PDLA) blends. Despite a number of studies on crystallization of nonequimolar PLLA/PDLA blends, a full picture of the effect of the L/D ratio is still lacking. Here, we put the two enantiomers in contact and allow interdiffusion above the melting point of the stereocomplex crystal (SC) to prepare samples with a continuously changing L/D ratio from enantiopure PLLA (ratio 0/100) to enantiopure PDLA (100/0). Using polarized optical microscopy, atomic force microscopy, and microbeam X-ray diffraction, the continuous spectrum of morphologies and phase behaviors across the contact zone is investigated. The blend morphology shows clear evidence of "poisoning by purity" of SC crystallization at all blend compositions. The low birefringence of the 50/50 SC is found to be due to the meandering of broken edge-on lamellae. Its further decrease to near zero as L/D deviates further away from 50/50 is explained by transition from radial edge-on lamellae to fully random meandering lamellae, then to mixed flat-on lamellae, and finally to submicron-sized axialites. In comparison with the smooth and straight homocrystal (HC) lamellae of pure enantiomers, the lamellae in the blends often have serrated edges caused by pinning by rejected excess enantiomer acting as an impurity during lamellar growth. A feature of the binary phase diagram is pure enantiomers acting as an impurity to the SC and counter-enantiomer acting as an impurity to homocrystallization of the enantiomers. Crystallization was found to be most suppressed at 99% enantiomeric purity, where the amount of the counter-enantiomer is insufficient for creation of SC nuclei and HC growth is inhibited by the small amount of the enantio-impurity. These and other intriguing results are less likely to be noticed without the continuous composition gradient of the contact sample.
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Affiliation(s)
- Jiaming Cui
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
| | - Shu-Gui Yang
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
| | - Ruibin Zhang
- Department
of Materials Science and Engineering, Sheffield
University, Sheffield S1 3JD, U.K.
| | - Yu Cao
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
| | - Yubo Wang
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
| | - Xiangbing Zeng
- Department
of Materials Science and Engineering, Sheffield
University, Sheffield S1 3JD, U.K.
| | - Feng Liu
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
| | - Goran Ungar
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an 710049, P. R. China
- Department
of Materials Science and Engineering, Sheffield
University, Sheffield S1 3JD, U.K.
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3
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Wang Y, Li YX, Cseh L, Chen YX, Yang SG, Zeng X, Liu F, Hu W, Ungar G. Enantiomers Self-Sort into Separate Counter-Twisted Ribbons of the Fddd Liquid Crystal─Antiferrochirality and Parachirality. J Am Chem Soc 2023; 145:17443-17460. [PMID: 37523689 PMCID: PMC10416214 DOI: 10.1021/jacs.3c06164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Indexed: 08/02/2023]
Abstract
The recently discovered orthorhombic liquid crystal (LC) phase of symmetry Fddd is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping. Although pure R and S enantiomers form only a strongly chiral hexagonal columnar LC phase (Colh*), the racemic mixture forms a highly ordered Fddd phase with 4 right- and 4 left-handed twisted ribbon-like columns traversing its large unit cell. In that structure, the two enantiomers locally deracemize and self-sort into the columns of their preferred chirality. The twisted ribbons in Fddd, with a 7.54 nm pitch, consist of stacked rafts, each containing ∼2 side-by-side molecules, the successive rafts rotated by 17°. In contrast, an analogous achiral compound forms only the columnar phase. The multiple methods used gave a comprehensive picture and helped in-depth understanding not only of the Fddd phase but also of the "parachiral" Colh* in pure enantiomers with irregular helicity, whose chirality is compared to the magnetization of a paramagnet in a field. Unusual short-range ordering effects are also described. An explanation of these phenomena is proposed based on conformational analysis. Surprisingly, the isotropic-columnar transition is extremely fast, completing within ∼20 ms. A clear effect of phase on UV-vis absorption and emission is observed.
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Affiliation(s)
- Yan Wang
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Ya-Xin Li
- School
of Chemistry and Chemical Engineering, Henan
University of Technology, Zhengzhou 450001, China
| | - Liliana Cseh
- Romanian
Academy, Coriolan Dragulescu Institute of Chemistry, Timisoara 300223, Romania
| | - Yong-Xuan Chen
- State
Key Laboratory of Coordinate Chemistry, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093, China
| | - Shu-Gui Yang
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Xiangbing Zeng
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
| | - Feng Liu
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Wenbing Hu
- State
Key Laboratory of Coordinate Chemistry, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093, China
| | - Goran Ungar
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
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4
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Yang SG, Zhang LQ, Chen C, Cui J, Zeng XB, Liu L, Liu F, Ungar G. 3D Morphology of Different Crystal Forms in β-Nucleated and Fiber-Sheared Polypropylene: α-Teardrops, α-Teeth, and β-Fans. Macromolecules 2023; 56:5502-5511. [PMID: 37521250 PMCID: PMC10373525 DOI: 10.1021/acs.macromol.3c00788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/20/2023] [Indexed: 08/01/2023]
Abstract
Polymorphism of semicrystalline polymers has significant influence on their physical properties, with each form having its advantages and disadvantages. However, real-life polymer processing often results in different coexisting crystal polymorphs, and it remains a challenge to determine their shape, spatial distribution, and volume fraction. Here, i-polypropylene (i-PP) sheets containing both α- and β-forms were prepared either by adding β-nucleating agent or by fiber pulling-induced crystallization. By adding a compatible dye that is partially rejected from the growing crystalline aggregates (spherulites and cylindrites), we visualize the shape of these objects in 3D using two-photon fluorescence confocal microscopy. To distinguish between crystal forms, we take advantage of the difference in dye-retaining ability of the α- and β-aggregates. Even in 2D, fluorescence microscopy (FM) distinguishes the two crystal forms better than polarized microscopy. In 3D imaging, the volume fraction and spatial distribution of α- and β-forms in different morphological types could be determined quantitatively. Morphologies described as α-teeth, β-fans, and α-teardrops were visualized for the first time in 3D. Furthermore, internal and surface microcracks were seen to be associated predominantly with the β-form and around the fiber. Spatial distribution of α- and β-forms was also determined by scanning with a synchrotron X-ray beam. Good agreement was obtained with 3D microscopy, but XRD could not match the detail obtainable by the tomography. The work demonstrates the ability of the 3D imaging method to distinguish different crystal forms and their specific morphologies.
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Affiliation(s)
- Shu-Gui Yang
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Liang-Qing Zhang
- College
of Material Science and Engineering, Xi’an
University of Science and Technology, Xi’an 710054, China
| | - Changlong Chen
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Jiaming Cui
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Xiang-bing Zeng
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
| | - Liying Liu
- Biomedical
Experimental Center of Xi’an Jiaotong University Health Science
Center, Xi’an 710116, China
| | - Feng Liu
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Goran Ungar
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
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5
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Huo H, Zou J, Yang SG, Zhang J, Liu J, Liu Y, Hao Y, Chen H, Li H, Huang C, Ungar G, Liu F, Zhang Z, Zhang Q. Multicompartment Nanoparticles by Crystallization-Driven Self-Assembly of Star Polymers: Combining High Stability and Loading Capacity. Macromol Rapid Commun 2023; 44:e2200706. [PMID: 36353903 DOI: 10.1002/marc.202200706] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/15/2022] [Indexed: 11/11/2022]
Abstract
Herein novel multicompartment nanoparticles (MCNs) that combine high stability and cargo loading capacity are developed. The MCNs are fabricated by crystallization-driven self-assembly (CDSA) of a tailor-made 21 arm star polymer, poly(L-lactide)[poly(tert-butyl acrylate)-block-poly(ethylene glycol)]20 [PLLA(PtBA-b-PEG)20 ]. Platelet-like or spherical MCNs containing a crystalline PLLA core and hydrophobic PtBA subdomains are formed and stabilized by PEG. Hydrophobic cargos, such as Nile Red and chemotherapeutic drug doxorubicin, can be successfully encapsulated into the collapsed PtBA subdomains with loading capacity two orders of magnitude higher than traditional CDSA nanoparticles. Depolarized fluorescence measurements of the Nile Red loaded MCNs suggest that the free volume of the hydrophobic chains in the nanoparticles may be the key for regulating their drug loading capacity. In vitro study of the MCNs suggests excellent cytocompatibility of the blank nanoparticles as well as a dose-dependent cellular uptake and cytotoxicity of the drug-loaded MCNs.
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Affiliation(s)
- Haohui Huo
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Jing Zou
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Shu-Gui Yang
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Jiaqi Zhang
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Jie Liu
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Yutong Liu
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Yanyun Hao
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Hongfei Chen
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Hui Li
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Chaobo Huang
- Joint Laboratory of Advanced Biomedical Materials (NFU-UGent), Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, P. R. China
| | - Goran Ungar
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Feng Liu
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Zhiyue Zhang
- NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, P. R. China
| | - Qilu Zhang
- Shaanxi International Research Center for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
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6
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Cui J, Yang SG, Zhang Q, Liu F, Ungar G. Poisoning by Purity: What Stops Stereocomplex Crystallization in Polylactide Racemate? Macromolecules 2023; 56:989-998. [PMID: 36818575 PMCID: PMC9933539 DOI: 10.1021/acs.macromol.2c02067] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/28/2022] [Indexed: 01/22/2023]
Abstract
Formation of stereocomplex crystals (SC) is an effective way to improve the heat resistance and mechanical performance of poly(lactic acid) products. However, at all but the slowest cooling rates, SC crystallization of a high-molecular-weight poly(l-lactic acid)/poly(d-lactic acid) (PLLA/PDLA) racemate stops at a high temperature or does not even start, leaving the remaining melt to crystallize into homochiral crystals (HC) or an SC-HC mixture on continuous cooling. To understand this intriguing phenomenon, we revisit the SC crystallization of both high- and low-molecular-weight PLLA/PDLA racemates. Based on differential scanning calorimetry (DSC), supplemented by optical microscopy and X-ray scattering, we concluded that what stops the growth of SC is the accumulation of the nearly pure enantiomer, either PDLA or PLLA, that is rejected from the SC ahead of its growth front. The excess enantiomer is a result of random compositional fluctuation present in the melt even if the average composition is 1:1. The situation is more favorable if the initial polymer is not fully molten or is brought up to just above the melting point where SC seeds remain, as proven by DSC and X-ray scattering. Moreover, we find that not only is SC growth poisoned by the locally pure enantiomer but also that at lower temperatures, the HC growth can be poisoned by the blend. This explains why SC growth, arrested at high temperatures, can resume at lower temperatures, along with the growth of HC. Furthermore, while some previous works attributed the incomplete SC crystallization to a problem of primary nucleation, we find that adding a specific SC-promoting nucleating agent does not help alleviate the problem of cessation of SC crystallization. This reinforces the conclusion that the main problem is in growth rather than in nucleation.
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Affiliation(s)
- Jiaming Cui
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an710049, China
| | - Shu-Gui Yang
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an710049, China,
| | - Qilu Zhang
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an710049, China
| | - Feng Liu
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an710049, China
| | - Goran Ungar
- Shaanxi
International Research Center for Soft Matter, State Key Laboratory
for Mechanical Behavior of Materials, Xi’an
Jiaotong University, Xi’an710049, China,Department
of Materials Science and Engineering, Sheffield
University, SheffieldS1 3JD, U.K.,,
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7
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Yang SG, Zhang LQ, Cui J, Zeng XB, Guo B, Liu F, Ungar G. Morphology of Shear-Induced Polymer Cylindrites Revealed by 3D Optical Imaging. Macromolecules 2022; 56:198-206. [PMID: 36644554 PMCID: PMC9835984 DOI: 10.1021/acs.macromol.2c01433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/30/2022] [Indexed: 11/11/2022]
Abstract
Two-photon confocal laser microscopy was used to obtain three-dimensional (3D) images of the morphology of poly(lactic acid) after shear-induced crystallization. The necessary fluorescence contrast was achieved by doping the polymer with Nile Red. The dye gets partially rejected from the growing crystalline aggregates during their formation, thus creating a renderable high-low fluorescence boundary outlining the shape of the aggregates. Parallel-plate melt-shearing and pulling a glass fiber through the melt were used as the two methods to achieve shear-induced crystallization. This study focuses on the shape of the resulting cylindrites, i.e., large-diameter shish-kebabs. The first 3D images of polymer cylindrites show that, if far from boundaries, they are circular cylinders, highly regular after fiber pull, but less so after parallel-plate shear. In the latter case, the cylindrite reveals the trajectory of the foreign particle that had nucleated its growth. Interestingly, lateral growth of the cylindrites was found to accelerate toward the sample surface when approaching it, giving the cylindrite an elliptical cross section. Furthermore and surprisingly, in the case of fiber pull, a row of spherulites is nucleated at the polymer-substrate interface nearest to the fiber, aligned along the fiber axis and appearing ahead of the rest of the space-filling spherulites. Both the phenomena, elliptical cylindrites and row of spherulites, are attributed to negative pressure buildup peaking at the cylindrite growth front and at the nearby film surface caused by crystallization-induced volume contraction. The pressure and flow distribution in the system is confirmed by numerical simulation. The results illustrate the value of 3D imaging of crystalline morphology in polymer science and polymer processing industry.
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Affiliation(s)
- Shu-Gui Yang
- Shaanxi
International Research Center for Soft Materials, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an710049, China,
| | - Liang-Qing Zhang
- College
of Material Science and Engineering, Xi’an
University of Science and Technology, Xi’an710054, China
| | - Jiaming Cui
- Shaanxi
International Research Center for Soft Materials, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an710049, China
| | - Xiang-bing Zeng
- Department
of Materials Science and Engineering, University
of Sheffield, SheffieldS1 3JD, U.K.
| | - Baolin Guo
- State
Key Laboratory for Mechanical Behavior of Materials, Frontier Institute
of Science and Technology, Xi’an
Jiaotong University, Xi’an710049, China
| | - Feng Liu
- Shaanxi
International Research Center for Soft Materials, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an710049, China
| | - Goran Ungar
- Shaanxi
International Research Center for Soft Materials, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an710049, China,Department
of Materials Science and Engineering, University
of Sheffield, SheffieldS1 3JD, U.K.,;
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8
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Zhang LQ, Yang SG, Zhang JH, Zhong KP, Zhao ZG, Chen YH, Lei J, Zhang QY, Li ZM. Insight into the Excellent Tribological Performance of Highly Oriented Poly(phenylene sulfide). Chin J Polym Sci 2022. [DOI: 10.1007/s10118-022-2672-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Yang SG, Wei ZZ, Cseh L, Kazemi P, Zeng XB, Xie HJ, Saba H, Ungar G. Bowls, vases and goblets-the microcrockery of polymer and nanocomposite morphology revealed by two-photon optical tomography. Nat Commun 2021; 12:5054. [PMID: 34417451 PMCID: PMC8379155 DOI: 10.1038/s41467-021-25297-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 07/29/2021] [Indexed: 11/09/2022] Open
Abstract
On the >1 µm scale the morphology of semicrystalline plastics like polyethylene or Nylon features spherulites, "shish-kebabs", cylinddrites and other crystalline aggregates which strongly affect mechanical and other material properties. Current imaging techniques give only a 2D picture of these objects. Here we show how they can be visualized in 3D using fluorescent labels and confocal microscopy. As a result, we see spherulites in 3D, both in neat polymers and their nanocomposites, and observe how unevenly nanoparticles and other additives are distributed in the material. Images of i-polypropylene and biodegradable poly(lactic acid) reveal previously unsuspected morphologies such as "vases" and "goblets", nonspherical "spherulites" and, unexpectedly, "shish-kebabs" grown from quiescent melt. Also surprisingly, in nanocomposite sheets spherulite nucleation is seen to be copied from one surface to another, mediated by crystallization-induced pressure drop and local melt-flow. These first results reveal unfamiliar modes of self-assembly in familiar plastics and open fresh perspectives on polymer microstructure.
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Affiliation(s)
- Shu-Gui Yang
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Centre for Soft Matter, Xi'an Jiaotong University, Xi'an, China
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
| | - Zhen-Zhen Wei
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
- College of Textile and Clothing Engineering, National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, China
| | - Liliana Cseh
- Romanian Academy, Coriolan Dragulescu Institute of Chemistry, Timisoara, Romania
| | - Pantea Kazemi
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
| | - Xiang-Bing Zeng
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
| | - Hui-Jie Xie
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou, China
| | - Hina Saba
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou, China
| | - Goran Ungar
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Centre for Soft Matter, Xi'an Jiaotong University, Xi'an, China.
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK.
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10
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Ren JY, Yang SG, Li Y, Lei J, Huang HD, Pan M, Lin H, Zhong GJ, Li ZM. Coupling effect of pressure and flow fields on the crystallization of Poly(vinylidene fluoride)/Poly(methyl methacrylate) miscible blends. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123565] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Zhang XX, Yang SG, Zhong GJ, Lei J, Liu D, Sun GA, Xu JZ, Li ZM. Rapid Melt Crystallization of Bisphenol-A Polycarbonate Jointly Induced by Pressure and Flow. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02208] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xi-Xi Zhang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Shu-Gui Yang
- State Key Laboratory for Mechanical Behaviour of Materials, Shanxi International Research Center for Soft Matter, Xi’an Jiaotong University, Xi’an 710049, P. R. China
| | - Gan-Ji Zhong
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Jun Lei
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Dong Liu
- Key Laboratory of Neutron Physics, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, 621999 Mianyang, P. R. China
| | - Guang-Ai Sun
- Key Laboratory of Neutron Physics, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, 621999 Mianyang, P. R. China
| | - Jia-Zhuang Xu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
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12
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Yang SG, Lei J, Zhong GJ, Xu JZ, Li ZM. Role of lamellar thickening in thick lamellae formation in isotactic polypropylene when crystallizing under flow and pressure. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Lin JM, Li Y, Xu L, Hua WQ, Yang SG, Bian FG, Lei J, Li ZM. Evolution of Polymorphic Structure in β-Nucleated Isotactic Polypropylene under a Certain Pressure: Effects of Temperature and Flow. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.8b06160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jian-Mei Lin
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Yue Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Ling Xu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Wen-Qiang Hua
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, P. R. China
| | - Shu-Gui Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Feng-Gang Bian
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, P. R. China
| | - Jun Lei
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
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14
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Zhang LQ, Yang SG, Li L, Yang B, Huang HD, Yan DX, Zhong GJ, Xu L, Li ZM. Correction to "Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding". ACS Appl Mater Interfaces 2019; 11:2559. [PMID: 30601646 DOI: 10.1021/acsami.8b21940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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15
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Zhang LQ, Yang SG, Li L, Yang B, Huang HD, Yan DX, Zhong GJ, Xu L, Li ZM. Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding. ACS Appl Mater Interfaces 2018; 10:40156-40167. [PMID: 30383958 DOI: 10.1021/acsami.8b14738] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Lightweight conductive polymer composites based on biomass could be a promising candidate for electromagnetic interference (EMI) shielding application. Herein, tailoring porous microstructure and regulating the distribution of carbon nanotubes (CNTs) in cellulose composites are attempts to achieve highly efficient EMI shielding properties accompanying desired mechanical property and low density. Specifically, aligned porous structure is fabricated by ice-template freeze-drying method; meanwhile, CNT is regulated to decorate inside the cellulose matrix (CNT-matrix/cellulose porous composites) or to directly bind over the cellulose cell walls (CNT-interface/cellulose porous composites). It is found that, owing to the preferential distribution of CNT on the cell walls, the CNT-interface/cellulose porous composites possess a very high electrical conductivity of 38.9 S m-1 with an extremely low percolation threshold of 0.0083 vol % with regard to CNT-matrix/cellulose porous composites. Therefore, a shielding effectiveness of 40 dB with merely 0.51 vol % CNT under a thickness of 2.5 mm is achieved in CNT-interface/cellulose porous composites, which is attributed to efficient multiple reflections and the accompanying absorption with promoted conductivity and better-defined porous structure. More laudably, the CNT-interface/cellulose porous composites reveal a superior mechanical property with a specific modulus of 279 MPa g-1 cm3. The value behind the current work is to pave an effective way to fabricate environmentally benign, high-performance EMI shielding materials to practically boost numerous advanced applications of cellulose.
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Affiliation(s)
- Liang-Qing Zhang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Shu-Gui Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Lei Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Biao Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Hua-Dong Huang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Ding-Xiang Yan
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Gan-Ji Zhong
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Ling Xu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , China
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16
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Yang SG, Li Y, Lei J, Zhong GJ, Li ZM. Oriented Polar Crystals in Poly(Vinylidene Fluoride) Produced by Simultaneously Applying Pressure and Flow. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201800299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shu-Gui Yang
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Yue Li
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Jun Lei
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Gan-Ji Zhong
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
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17
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Song YN, Zhao QX, Yang SG, Ru JF, Lin JM, Xu JZ, Lei J, Li ZM. Flow-induced crystallization of polylactide stereocomplex under pressure. J Appl Polym Sci 2018. [DOI: 10.1002/app.46378] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ying-Nan Song
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Qing-Xiang Zhao
- College of Manufacturing Science and Engineering, Provincial Laboratory of CAD/CAM; Sichuan University; Chengdu 610065 China
| | - Shu-Gui Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Jia-Feng Ru
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Jian-Mei Lin
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Jia-Zhuang Xu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Jun Lei
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
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18
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Wang Y, Zhao J, Qu M, Guo J, Yang SG, Lei J, Xu JZ, Chen YH, Li ZM, Hsiao BS. An unusual promotion of γ-crystals in metallocene-made isotactic polypropylene from orientational relaxation and favorable temperature window induced by shear. POLYMER 2018. [DOI: 10.1016/j.polymer.2017.11.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Yang SG, Ma Z, Lei J, Li L, Hsiao BS, Li ZM. A Criterion for Flow-Induced Oriented Crystals in Isotactic Polypropylene under Pressure. Macromol Rapid Commun 2017; 38. [DOI: 10.1002/marc.201700407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 07/27/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Shu-Gui Yang
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Zhe Ma
- Tianjin Key Laboratory of Composite and Functional Materials; and School of Materials Science and Engineering; Tianjin University; Tianjin 300072 China
| | - Jun Lei
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
| | - Liangbin Li
- National Synchrotron Radiation Lab and College of Nuclear Science and Technology; CAS Key Laboratory of Soft Matter Chemistry; University of Science and Technology of China; Hefei 230026 China
| | - Benjamin S. Hsiao
- Department of Chemistry; Stony Brook University; New York NY 11794 USA
| | - Zhong-Ming Li
- College of Polymer Science and Engineering; State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu 610065 China
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20
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Yang SG, Chen YH, Deng BW, Lei J, Li L, Li ZM. Window of Pressure and Flow To Produce β-Crystals in Isotactic Polypropylene Mixed with β-Nucleating Agent. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00041] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shu-Gui Yang
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Yan-Hui Chen
- Department
of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’an 710129, China
| | - Bo-Wen Deng
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Jun Lei
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Liangbin Li
- National
Synchrotron Radiation Lab and College of Nuclear Science and Technology,
CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Zhong-Ming Li
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
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21
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Ru JF, Yang SG, Lei J, Li ZM. Thicker Lamellae and Higher Crystallinity of Poly(lactic acid) via Applying Shear Flow and Pressure and Adding Poly(ethylene Glycol). J Phys Chem B 2017; 121:5842-5852. [DOI: 10.1021/acs.jpcb.7b02241] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jia-Feng Ru
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Shu-Gui Yang
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Jun Lei
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhong-Ming Li
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
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22
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Ru JF, Yang SG, Zhou D, Yin HM, Lei J, Li ZM. Dominant β-Form of Poly(l-lactic acid) Obtained Directly from Melt under Shear and Pressure Fields. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00595] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jia-Feng Ru
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Shu-Gui Yang
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Dong Zhou
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Hua-Mo Yin
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Jun Lei
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhong-Ming Li
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
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23
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Zhang J, Yang SG, Ding JX, Li ZM. Tailor-made poly(l-lactide)/poly(lactide-co-glycolide)/hydroxyapatite composite scaffolds prepared via high-pressure compression molding/salt leaching. RSC Adv 2016. [DOI: 10.1039/c6ra06906a] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The degradation rate, hydrophilicity, and mechanical properties of PLLA/PLGA/HA scaffolds can be tuned by adjusting the composition. Such tailor-made scaffolds are hopeful to address the specific requirements of the regenerated tissue.
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Affiliation(s)
- Jin Zhang
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu 610065
- P. R. China
| | - Shu-Gui Yang
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu 610065
- P. R. China
| | - Jian-Xun Ding
- Key Laboratory of Polymer Ecomaterials
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022
- P. R. China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu 610065
- P. R. China
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24
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Zhou D, Yang SG, Lei J, Hsiao BS, Li ZM. Role of Stably Entangled Chain Network Density in Shish-Kebab Formation in Polyethylene under an Intense Flow Field. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01402] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dong Zhou
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Shu-Gui Yang
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Jun Lei
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Benjamin S. Hsiao
- Department
of Chemistry, Stony Brook University, New York 11794, United States
| | - Zhong-Ming Li
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu, 610065, China
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25
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Yang SG, Zhang Z, Zhou D, Wang Y, Lei J, Li L, Li ZM. Flow and Pressure Jointly Induced Ultrahigh Melting Temperature Spherulites with Oriented Thick Lamellae in Isotactic Polypropylene. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01043] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shu-Gui Yang
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhengchi Zhang
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Dong Zhou
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Yan Wang
- School
of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Jun Lei
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Liangbin Li
- National
Synchrotron Radiation Lab and College of Nuclear Science and Technology,
CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Zhong-Ming Li
- College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
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26
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Yang SG, Zhang Z, Zhang LQ, Zhou D, Wang Y, Lei J, Li L, Li ZM. Unexpected shear dependence of pressure-induced γ-crystals in isotactic polypropylene. Polym Chem 2015. [DOI: 10.1039/c5py00339c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Flow and pressure frequently coexist in practical polymer processing operations, but their combined influence on the microstructure of polymer parts has received very limited attention in the academic community.
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Affiliation(s)
- Shu-Gui Yang
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
| | - Zhengchi Zhang
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
| | - Liang-Qing Zhang
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
| | - Dong Zhou
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
| | - Yan Wang
- School of Textile and Material Engineering
- Dalian polytechnic University
- Dalian
- China
| | - Jun Lei
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
| | - Liangbin Li
- National Synchrotron Radiation Lab and College of Nuclear Science and Technology
- CAS Key Laboratory of Soft Matter Chemistry
- University of Science and Technology of China
- Hefei
- China
| | - Zhong-Ming Li
- College of Polymer Science and Engineering
- State Key Laboratory of Polymer Materials Engineering
- Sichuan University
- Chengdu
- China
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27
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An HS, Yang SG, Moon TS, Park JY, Hong CG, Hwang HK, Myeong JI, An CM. Comparison of genetic diversity between wild-caught broodstock and hatchery-produced offspring populations of the vulnerable Korean kelp grouper (Epinephelus bruneus) by microsatellites. Genet Mol Res 2014; 13:9675-86. [PMID: 25501179 DOI: 10.4238/2014.november.14.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The kelp grouper Epinephelus bruneus (Perciformes: Haemulidae), is one of the most economically important fishery resources in Korea. This fish is regarded as a target for prospective aquaculture diversification; therefore, maintenance of stock quality is important. To investigate the effects of current artificial reproduction in a hatchery facility, genetic variation in wild-caught broodstock and hatchery-produced offspring of kelp grouper was analyzed using eight polymorphic nuclear microsatellite DNA loci; 77 alleles were identified. Allelic variability ranged from 2 to 22 in the broodstock and from 1 to 10 in the offspring. The average observed and expected heterozygosities were 0.620 and 0.623 in the broodstock and 0.600 and 0.513 in the offspring, respectively. The possibility of a recent genetic bottleneck was suggested in both populations of E. bruneus. The minor, but significant, genetic differentiation (FST = 0.047, P < 0.05) observed was mainly due to statistically significant reductions in the number of alleles in the offspring compared with the broodstock, suggesting that these genetic changes could be related to genetic drift. Our results demonstrate the usefulness of microsatellite markers to monitor genetic variation and raise concerns about potential harmful genetic effects of inappropriate hatchery procedures. Therefore, genetic variation between broodstock and offspring in a hatchery should be monitored in both breeding and release programs as a routine hatchery operation, and inbreeding should ideally be controlled to improve kelp grouper hatchery management. Our data provide a useful genetic basis for future planning of sustainable culture and management of E. bruneus in fisheries.
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Affiliation(s)
- H S An
- Biotechnology Research Division, National Fisheries Research and Development Institute, Busan, Korea
| | - S G Yang
- Future Aquaculture Research Center, Jeju-do, Korea
| | - T S Moon
- Future Aquaculture Research Center, Jeju-do, Korea
| | - J Y Park
- Aquaculture Industry Division, National Fisheries Research and Development Institute, Yeosu, Korea
| | - C G Hong
- Aquaculture Industry Division, National Fisheries Research and Development Institute, Yeosu, Korea
| | - H K Hwang
- Aquaculture Management Division, National Fisheries Research and Development Institute, Busan, Korea
| | - J I Myeong
- Aquaculture Management Division, National Fisheries Research and Development Institute, Busan, Korea
| | - C M An
- Biotechnology Research Division, National Fisheries Research and Development Institute, Busan, Korea
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28
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Fang Y, Song YQ, Zhou WP, Zhao R, Tang RJ, Yang H, Lv LY, Yang SG, Wang DH, Du YW. Large magnetoelectric coupling in Co4Nb2O9. Sci Rep 2014; 4:3860. [PMID: 24463631 PMCID: PMC3902385 DOI: 10.1038/srep03860] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/03/2014] [Indexed: 12/05/2022] Open
Abstract
Magnetoelectric materials which simultaneously exhibit electric polarization and magnetism have attracted more and more attention due to their novel physical properties and promising applications for next-generation devices. Exploring new materials with outstanding magnetoelectric performance, especially the manipulation of magnetization by electric field, is of great importance. Here, we demonstrate the cross-coupling between magnetic and electric orders in polycrystalline Co4Nb2O9, in which not only magnetic-field-induced electric polarization but also electric field control of magnetism is observed. These results reveal rich physical phenomenon and potential applications in this compound.
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Affiliation(s)
- Y Fang
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - Y Q Song
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - W P Zhou
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - R Zhao
- Jiangsu Key Laboratory of Thin Films, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - R J Tang
- Jiangsu Key Laboratory of Thin Films, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - H Yang
- Jiangsu Key Laboratory of Thin Films, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - L Y Lv
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - S G Yang
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - D H Wang
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
| | - Y W Du
- National Laboratory of Solid State Microstructures and Key Laboratory of Nanomaterials for Jiang Su Province, Nanjing University, Nanjing 210093, People's Republic of China
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Kang JH, Yang SG, Moon TS, Park JY, Choi TJ. Development of microsatellite markers for the kelp grouper Epinephelus bruneus by 454 pyrosequencing and transfer to related species. Genet Mol Res 2013; 12:5485-93. [PMID: 24301919 DOI: 10.4238/2013.november.13.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The kelp or longtooth grouper (Epinephelus bruneus), which inhabits Eastern Asia, is the most economically important of 11 grouper species that inhabit the Southern Sea near Jeju Island in Korea. This species is listed as vulnerable by the International Union for the Conservation of Nature and Natural Resources because of a rapid decrease in its resources. We developed microsatellite markers for E. bruneus using the pyrosequencing technique for applications in resource management and aquaculture. In addition, we tested the cross-species transferability of the microsatellite markers in four species belonging to the Epinephelus genus. Among 66,452 simple sequence repeats, 64 loci containing more than eight CA or TG repeats were randomly selected for primer synthesis; 45 primer sets (75.0%) produced polymerase chain reaction (PCR) products of 100-300 bp and were selected as candidates. After primary testing with four E. bruneus fish, 28 polymorphic loci were selected as the final microsatellite markers, and 23 sets showing clear amplification of polymorphic loci were used to analyze 71 fish. These loci have allele numbers ranging from 2 to 23. Null alleles were detected at three loci, and three loci showed an excess of homozygotes in the Hardy-Weinberg equilibrium test. Of the three species used for cross-species transfer of these markers, Epinephelus moara showed the highest transferability (92.9%) and polymorphism (67.9%), followed by Epinephelus fuscoguttatus (75.0 and 67.9%, respectively) and Epinephelus septemfasciatus (57.1 and 46.4%, respectively). These results suggested that these microsatellite loci should be valuable tools for population genetic studies of the species Epinephelus.
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Affiliation(s)
- J-H Kang
- Biotechnology Research Division, National Fisheries Research and Development Institute, Busan, Republic of Korea
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Pang H, Bao Y, Yang SG, Chen C, Zhang WQ, Chen J, Ji X, Lei J. Preparation and properties of carbon nanotube/binary-polymer composites with a double-segregated structure. J Appl Polym Sci 2013. [DOI: 10.1002/app.39789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Huan Pang
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Yu Bao
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Shu-Gui Yang
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Chen Chen
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Wei-Qin Zhang
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Jun Chen
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Xu Ji
- College of Chemical Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
| | - Jun Lei
- College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering; Sichuan University; Chengdu Sichuan 610065 People's Republic of China
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Zhao CF, Liu Y, Que HP, Yang SG, Liu T, Liu ZQ, Hui HD, Liu S. Rnh1 promotes differentiation and myelination via RhoA in oligodendrocytes. Cell Tissue Res 2013; 353:381-9. [PMID: 23624614 DOI: 10.1007/s00441-013-1625-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 04/04/2013] [Indexed: 01/20/2023]
Abstract
Increases in Rattus norvegicus ribonuclease/angiogenin inhibitor 1 (Rnh1) are observed in rat primary neuron injury and/or the regeneration process and in differentiated oligodendrocytes. However, the roles of Rnh1 in the central nervous system are still largely unexplored. RhoA is an important signaling protein that has been implicated in oligodendrocyte differentiation and myelination. We demonstrate enhanced differentiation and myelination of oligodendrocytes mediated by Rnh1 in vitro. We further show that Rnh1 is expressed in oligodendrocyte precursors and oligodendrocytes. Importantly, Rnh1 strongly affects oligodendrocyte differentiation through RhoA-ROCK signaling. Moreover, changes in Rnh1 expression in oligodendrocytes regulates the expression and phosphorylation of Fyn, a regulator of RhoA activity. Finally, Rnh1 promotes myelination in vitro. These results show that Rnh1-mediated RhoA inactivation enhances the differentiation and myelination in oligodendrocytes. Overall, Rnh1 might contribute to oligodendrocyte differentiation and myelination processes in vitro.
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Affiliation(s)
- C F Zhao
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, The Academy of Military Medical Sciences, Beijing, 100850, People's Republic of China
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Yang SG, Wo JE, Li MW, Yu CB, Lv GL, Cao HC, Lu HF, Wang BH, Zhu HP, Li LJ. Construction and packaging of Semliki forest virus replicon particles efficiently expressing Influenza A virus (H5N1) hemagglutinin. Acta Virol 2009; 53:139-41. [PMID: 19537917 DOI: 10.4149/av_2009_02_139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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33
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Gu CG, Ju XH, Jiang X, Wang F, Yang SG, Sun C. DFT study on the bromination pattern dependence of electronic properties and their validity in quantitative structure-activity relationships of polybrominated diphenyl ethers. SAR QSAR Environ Res 2009; 20:287-307. [PMID: 19544193 DOI: 10.1080/10629360902949468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
With quantum chemical computation of density functional theory (DFT), the electronic properties including the polarisabilities, polarisability anisotropies and quadrupole moments of a total of 209 congeners of polybrominated diphenyl ethers (PBDEs) were evaluated. The electronic properties were shown to be highly dependent on the bromination pattern, i.e. their values changed sensitively with the number and sites of bromination. Being similar to the 2,3,7,8-, 1,4,6,9-chlorination of dioxins, respectively, 3,3',4,4'-, 2,2',5,5'-bromination of PBDEs can impose relatively greater effects on the electronic properties. Some of electronic properties were found to be potent in explaining the variance of toxicity, and the potency was verified by the development of quantitative structure-activity relationships (QSARs). To further improve the stability and predictability of QSARs for toxicity, two-dimensional topological indices were introduced. In QSARs, polarisability anisotropy was more significant than other polarisability tensors, indicating the implicit occurrence of dispersion interaction between the ligand and aryl hydrocarbon receptor (AhR). For PBDEs, the quadrupole moment was as significant as shown previously for dioxins. As interesting descriptors with encoded information about dispersion and electronics, the electronic properties analysed herein are helpful in obtaining a better understanding of the congener-specific toxicities of PBDEs, and are applicable and may be extended to research into the toxicology of structurally similar compounds, such as halogenated aromatics.
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Affiliation(s)
- C G Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, PR China.
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Yang SG, Kim DD, Chung SJ, Shim CK. Stable bioavailability of cyclosporin A, regardless of food intake, from soft gelatin capsules containing a new self-nanoemulsifying formulation. Int J Clin Pharmacol Ther 2006; 44:233-9. [PMID: 16724578 DOI: 10.5414/cpp44233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
AIM We recently succeeded in preparing soft gelatin capsules containing a new self-nanoemulsifying formulation consisting of cyclosporin A (CsA), triacetin, polyoxyl 40 hydrogenated castor oil, polysorbate 20, medium chain triglycerides and medium chain mono- and diglycerides. The soft capsules containing the new formulation exhibited a significantly improved physical stability in terms of the appearance of the gelatin capsule shells and the composition of the fill mass during long-term storage, compared to commercially available soft capsules containing CsA, in which ethanol was employed as a cosolvent of CsA. In the present study, the influence of a fat-rich meal on the bioavailability of CsA from the soft capsule containing the new formulation (test drug) was evaluated and the results compared to those obtained with a representative soft capsule of CsA. VOLUNTEERS AND METHODS A randomized, open-label, 3-way crossover study was performed in the test capsules and reference soft capsules, in a fasted state or after a fat-rich breakfast. 18 healthy male volunteers received a single dose of the reference formulation (Neoral, Novartis AG, Basel, Switzerland) or test formulation (2 capsules each, 200 mg as CsA) with 240 ml of water with a 1-week washout period between the treatments, after a fat-rich (670 kcal, 45 g fat) breakfast (for the test drug, Treatment A; for the reference drug, Treatment B) or a 12-h fasting (for the test drug, Treatment C). Serial blood samples, collected over a 24-h period after the administration, were assayed for blood CsA concentrations using a specific monoclonal radioimmunoassay. RESULTS The differences in bioavailability parameters (i.e., AUC(0-24h), AUC(0-infinity) and C(max)) between the treatments were within the range of 80-125% of the reference treatment. An analysis of variance (ANOVA) revealed no significant differences (p > 0.05) between subjects, formulations or periods. The 90% confidence intervals (CI) indicated that the differences between the treatments (Treatments A and B, Treatments A and C) were also within the criteria. CONCLUSION These results indicate that the bioavailability of CsA from the test drug is equivalent to reference in the fed state, and is likely to be less influenced by a fat-rich meal. Therefore, the new formulation of CsA using triacetin appears to have an advantage over the commercial soft capsules of CsA using a volatile cosolvent such as ethanol.
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Affiliation(s)
- S G Yang
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul, Korea
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Duan JH, Yang SG, Liu HW, Gong JF, Huang HB, Zhao XN, Zhang R, Du YW. Preparation and Characterization of Straight and Zigzag AlN Nanowires. J Phys Chem B 2005; 109:3701-3. [PMID: 16851410 DOI: 10.1021/jp044569o] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hexagonal single-crystal AlN nanowires with straight or zigzag morphologies were successfully synthesized by the reaction of aluminum alloy in an ammonia/nitrogen atmosphere at 1100 degrees C. It is found that the crystal tropism of the nanowires is along [0001], whereas the growth directions of the zigzag nanowires shift between [2111] and [2111].
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Lee YH, Kim HS, Kim JY, Jung M, Park YS, Lee JS, Choi SH, Her NH, Lee JH, Hyung NI, Lee CH, Yang SG, Harn CH. A new selection method for pepper transformation: callus-mediated shoot formation. Plant Cell Rep 2004; 23:50-58. [PMID: 15221276 DOI: 10.1007/s00299-004-0791-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Revised: 02/25/2004] [Accepted: 02/25/2004] [Indexed: 05/24/2023]
Abstract
We used two genes, TMV-CP and PPI1 (pepper-PMMV interaction 1 transcription factor), to transform commercially important chili pepper (Capsicum annuum) inbred lines (P915, P409) by means of Agrobacterium co-culture. Eighteen independently transformed T0 plants were obtained. The most critical point in the pepper transformation protocol was the selection of shoots growing on calli--referred to as callus-mediated shoot formation (indirect shooting)--because shoots not grown from the callus (direct shooting from the wounded surface) developed into non-transformants. Selection of the correct right callus type also proved to be an important requirement for obtaining transformed peppers. Six different types of callus developed during the selection process. Shoots regenerated from two of these types, while one type regenerated significantly more shoots than the other types, suggesting that the capacity for shoot formation is callus type-specific. Although the transformation rate was low, transformation via callus-mediated shoot formation proved to be reproducible and was confirmed by Southern and Northern blot analyses. Based on the experimental data, we have succeeded in developing a new protocol for the selection and transformation of pepper and expect that it will be used in the future for pepper transformation.
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Affiliation(s)
- Y H Lee
- Breeding Institute, Nong Woo Bio Co., 537-17, Jeongdan, 469-885, Yeoju, Gyeonggi, South Korea.
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Lu GH, Zhao YH, Yang SG, Cheng XJ. Quantitative structure-biodegradability relationships of substituted benzenes and their biodegradability in river water. Bull Environ Contam Toxicol 2002; 69:111-6. [PMID: 12053264 DOI: 10.1007/s00128-002-0016-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Affiliation(s)
- G H Lu
- College of Water Resources and Environment, Hohai University, Nanjing, 210098 People's Republic of China
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McElhinney DB, Yang SG, Hogarty AN, Rychik J, Gleason MM, Zachary CH, Rome JJ, Karl TR, Decampli WM, Spray TL, Gaynor JW. Recurrent arch obstruction after repair of isolated coarctation of the aorta in neonates and young infants: is low weight a risk factor? J Thorac Cardiovasc Surg 2001; 122:883-90. [PMID: 11689792 DOI: 10.1067/mtc.2001.116316] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Repair of aortic coarctation is often delayed in small infants because of the belief that such patients are at risk of recurrent arch obstruction and that growth will decrease this risk. To determine whether low weight was a risk factor for recurrent arch obstruction, we reviewed our experience with coarctation repair via left thoracotomy in infants less than 3 months of age. METHODS From 1990 to 1999, 103 patients less than 3 months of age underwent repair of aortic coarctation through a left thoracotomy. Median age was 18 days (1-90 days), with 45 patients less than 2 weeks. Median weight was 3.3 kg (1.0-6.4 kg) and 14 patients were less than 2 kg. The method of repair was resection and end-to-end anastomosis in 64 patients, subclavian flap angioplasty in 34, and patch augmentation of the arch in 5. Demographic, echocardiographic, and operative variables were analyzed for correlation with recurrent arch obstruction. RESULTS One early and 1 late death occurred, both in patients who had complications but no evidence of recoarctation. At median follow-up of 24 months, reinterventions for recurrent arch obstruction were performed in 15 patients. The median time to reintervention was 5 months and was less than 1 year in 12 patients. Kaplan-Meier freedom from arch reintervention was 88% at 1 year (95% confidence intervals: 82%-94%) and 82% at 5 years (95% confidence intervals: 72%-92%). Factors associated with shorter duration to arch reintervention by univariable Cox regression included younger age (continuous, P =.01; <2 weeks, P =.005), smaller transverse arch (absolute diameter, P <.001; indexed to weight, P =.03; indexed to ascending aortic diameter, P =.02), and smaller ascending aorta (absolute diameter, P =.02). Smaller absolute transverse arch diameter and younger age were the only independent predictors of shorter time to arch reintervention by multivariable Cox regression analysis. Weight and type of repair did not correlate with risk of recoarctation. CONCLUSIONS Low weight is not a risk factor for recurrent obstruction after repair of coarctation of the aorta in infants less than 3 months of age. Rather, risk of recoarctation is more a function of the anatomy of the arch. Thus, it is not indicated to delay repair in low weight infants with the goal of achieving growth.
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Affiliation(s)
- D B McElhinney
- Division of Pediatric Cardiothoracic Surgery, The Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, USA
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Kim CK, Shin HJ, Yang SG, Kim JH, Oh YK. Once-a-day oral dosing regimen of cyclosporin A: combined therapy of cyclosporin A premicroemulsion concentrates and enteric coated solid-state premicroemulsion concentrates. Pharm Res 2001; 18:454-9. [PMID: 11451031 DOI: 10.1023/a:1011046109078] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop once-a-day oral dosing regimen that provides the blood levels of cyclosporin A (CsA) in the therapeutic ranges over 24 hours. METHODS CsA premicroemulsion concentrates (preME) were formulated from phase diagrams. Enteric-coated solid-state premicroemulsion concentrates (sME) were prepared by coating preME with enteric-coating matrials and solidifying them. CsA was measured using high-performance liquid chromatography or radioimmunoassay. RESULTS PreME consisted of CsA, oil, and mixture of surfactants and a cosurfactant. PreME spontaneously formed microemulsions in aqueous medium and showed oral absorption profiles similar to Sandimmune Neoral in dogs. Dispersion of sME in aqueous medium also formed microemulsions. Release rates of CsA from sME depended on pH and the type of enteric-coating materials and highly correlated with the extent of oral absorption. The co-administration of preME and sME (200 mg CsA) showed the maximum blood level of CsA not significantly different from that of preME (100 mg CsA) and the concentration of CsA close to the minimum therapeutic level at 24 hours. CONCLUSIONS The combined treatment of preME and sME provided controlled oral absorption of CsA over a 24-hour period. Such once-a-day dosing regimens will lead to increased patient compliance and reduced episodes of organ rejection after transplantation.
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Affiliation(s)
- C K Kim
- College of Pharmacy, Seoul National University, South Korea.
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Huang KH, Yang SG, Tang JX. [Improvement of amplification method for Cryptosporidium parvum oocysts from mice]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2001; 19:360-2. [PMID: 12572074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
OBJECTIVE To establish a simplified amplification method for obtaining a large number of purified Cryptosporidium parvum oocysts from infected C57BL/6N mice. METHODS All mice in the experimental groups were immunosuppressed by given different concentrations of dexamethasone phosphate added in drinking water throughout the experiment. The recovery and purity of the oocysts obtained using different purification methods was compared. The infectivity of the oocysts obtained from the same origin but different animals and different purification methods in a bovine fallopian tube epithelial cell culture system was studied. RESULTS 4.16 x 10(9) oocysts were obtained in 30 mice in the 3rd group with dexamethasone of 20 micrograms/ml in drinking water. No significant difference in the oocyst recovery, purity and infectivity was found between methods using saturated saline floatation and sucrose density gradient centrifugation. The infectivity of the oocysts obtained from the same origin but different animals was similar. CONCLUSION A simplified amplification method for obtaining a large number of purified Cryptosporidium parvum oocysts from the infected mice was established.
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Affiliation(s)
- K H Huang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095
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Yang SG, Novello R, Nicolson S, Steven J, Gaynor JW, Spray TL, Rychik J. Evaluation of ventricular septal defect repair using intraoperative transesophageal echocardiography: frequency and significance of residual defects in infants and children. Echocardiography 2000; 17:681-4. [PMID: 11107205 DOI: 10.1046/j.1540-8175.2000.00681.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intraoperative transesophageal echocardiography (IOTEE) is commonly used to assess for residual defect and the need to return to bypass after repair of ventricular septal defect (VSD). The frequency and significance of residual septal defects as noted on IOTEE has not been well defined. We evaluated the frequency of residual VSD via IOTEE and the relationship between size of a residual VSD and rate of reoperation. In addition, we looked at the relationship between the presence of a residual VSD via IOTEE and the presence of residual VSD at follow-up transthoracic echocardiography (TTE). Residual VSD was measured via the largest width of the Doppler color jet diameter originating at the left ventricular septal surface. Of the 294 patients evaluated with IOTEE after VSD repair, one-third had a residual defect by IOTEE Doppler color flow mapping. Two-thirds of these defects closed spontaneously on TTE by the time of hospital discharge. There was no difference in frequency of residual VSD between simple (VSD closure alone, n = 90) and complex (VSD with associated lesions, n = 204) repair. Return to bypass with immediate reoperation was undertaken in nine patients, all of whom had significant shunt via oximetry (Qp/Qs > 1.5:1.0). All had residual VSD color jet diameters > 3 mm. Seven patients had residual color jet equal to 3 mm; however, hemodynamic studies did not reveal a significant shunt and none of these had reoperation. Seven patients with no VSD or < 3 mm residual VSD via had late reoperation to close residual VSD at 4 days to 5 months after initial operation. These were due to patch dehiscence or development of an "intramural" VSD in patients with conotruncal anomaly. A residual defect on IOTEE color Doppler measuring > or = 4 mm predicts the need for immediate reoperation, while a 3 mm defect may be significant and requires additional intraoperative hemodynamic evaluation. The majority of small defects noted on IOTEE are not present at discharge TTE. Patients with conotruncal defect repair should be followed closely for development of late significant "intramural" defects.
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Affiliation(s)
- S G Yang
- Division of Cardiology, Cardiac Anesthesiology and Cardiothoracic Surgery, The Children's Hospital of Philadelphia, 34th Street and Civic Center Blvd., Philadelphia, PA 19104, USA
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Abstract
We report on a case of clear cell acanthoma that developed above a preexisting melanocytic nevus. Although melanocytic nevi can be complicated by the presence of several different types of epithelial or appendageal tumors, there have been no reported case of clear cell acanthoma combined with a nevus. Interestingly, in this case the clear cell acanthoma had a polypoid configuration, an unusual finding.
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Affiliation(s)
- S G Yang
- Department of Dermatology, Seoul National University College of Medicine, Korea
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Jun K, Choi G, Yang SG, Choi KY, Kim H, Chan GC, Storm DR, Albert C, Mayr GW, Lee CJ, Shin HS. Enhanced hippocampal CA1 LTP but normal spatial learning in inositol 1,4,5-trisphosphate 3-kinase(A)-deficient mice. Learn Mem 1998; 5:317-30. [PMID: 10454357 PMCID: PMC311247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
To define the physiological role of IP(3)3-kinase(A) in vivo, we have generated a mouse strain with a null mutation of the IP(3)3-kinase(A) locus by gene targeting. Homozygous mutant mice were fully viable, fertile, apparently normal, and did not show any morphological anomaly in brain sections. In the mutant brain, the IP4 level was significantly decreased whereas the IP3 level did not change, demonstrating a major role of IP(3)3-kinase(A) in the generation of IP4. Nevertheless, no significant difference was detected in the hippocampal neuronal cells of the wild-type and the mutant mice in the kinetics of Ca2+ regulation after glutamate stimulation. Electrophysiological analyses carried out in hippocampal slices showed that the mutation significantly enhanced the LTP in the hippocampal CA1 region, but had no effect on the LTP in dentate gyrus (DG). No difference was noted, however, between the mutant and the wild-type mice in the Morris water maze task. Our results indicate that IP(3)3-kinase(A) may play an important role in the regulation of LTP in hippocampal CA1 region through the generation of IP4, but the enhanced LTP in the hippocampal CA1 does not affect spatial learning and memory.
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Affiliation(s)
- K Jun
- National Creative Research Initiatives Center for Calcium and Learning and Department of Life Science, Pohang University of Science and Technology, Korea
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Abstract
Glomeruloid hemangioma is a term that was coined J.K.C. Chan and colleagues in 1990 because the condition is histopathologically similar to renal glomeruli. In the three cases described to date, there have been signs of POEMS syndrome of multicentric Castleman's disease. We present the case of a 44-year-old Korean woman who developed glomeruloid hemangioma in association with multicentric Castleman's disease and some features of POEMS syndrome. It is interesting that in this patient, the first biopsy specimen revealed an immature vascular tumor that could not be precisely classified and the second indicated glomeruloid hemangioma. The present case may lend support to the suggestion that in POEMS disease, some types of vascular proliferations develop in response to angiogenic stimuli that show a spectrum of histopathologic features, and glomeruloid hemangioma is one of the reactive vascular proliferations. We believe that the primitive vascular tumor seen in the first biopsy specimen may be the most immature stage of this spectrum.
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Affiliation(s)
- S G Yang
- Department of Dermatology, Seoul National University College of Medicine, South Korea
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Abstract
We describe a case of malignant proliferating trichilemmal tumor showing multiple distant metastases. For 10 years, the patient had had a round mass in the occiput, which recurred twice after wide excisions, and later metastasized to the cervical lymph nodes, periparotid area, and chest. Each time the lesions were excised, histologic specimens demonstrated a proliferating trichilemmal tumor with increasing nuclear atypia. Serial specimens showed increasing Ki-67 positivity as the extent of the tumor advanced.
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Affiliation(s)
- B S Park
- Department of Dermatology, Seoul National University College of Medicine, Korea
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Cho KH, Kim CW, Kwon OS, Yang SG, Park KC, Park MH, Cho HI, Kim JG. Epstein-Barr virus-associated lymphoproliferative eruption with progression to large granular lymphocytic leukaemia. Br J Dermatol 1997; 137:426-30. [PMID: 9349343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A 12-year-old Korean girl gave a 9-year history of recurrent necrotizing papules and vesicles on the face, scalp and extremities. Skin biopsy specimens showed an atypical lymphoreticular infiltrate with vasculitis in the dermis and subcutis. In situ hybridization demonstrated latent infection by Epstein-Barr virus (EBV) of the lymphoid cells in the dermis. The disease was diagnosed as an EBV-associated lymphoproliferative skin eruption presenting as recurrent necrotic papulovesicles. The patient subsequently developed large granular lymphocytic leukaemia of natural killer cell origin. Our observations suggest that a patient with an EBV-associated lymphoproliferative skin eruption presenting with recurrent necrotic papulovesicles might progress to develop leukaemia as well as lymphoma.
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Affiliation(s)
- K H Cho
- Department of Dermatology, Seoul National University College of Medicine, Korea
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Abstract
We analysed 134 Korean cases with inflammatory nodules of the lower legs on the basis of clinicopathological findings, responsiveness to various therapeutic agents, and clinical course. There were 53 cases of erythema induratum (EI), 18 of erythema nodosum (EN), 40 of EN-like lesions of Behcet's disease, 15 of other entities, including superficial migratory thrombophlebitis, cutaneous periarteritis nodosa, sarcoidosis, malignant lymphoma, Churg-Strauss syndrome, and parasitosis, and eight unclassified cases. The unclassified group was composed of a spectrum of diseases with clinicopathologic features ranging between those typical of EN and EI. The present study revealed that the profiles of diseases featuring inflammatory nodules of the lower legs in Korea differed from those found in other areas. These geographic and demographic differences should be kept in mind when managing a patient with inflammatory nodules of the lower legs.
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Affiliation(s)
- K H Cho
- Department of Dermatology, Seoul National University College of Medicine, Korea
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Yang SG, Han KH, Cho KH, Lee AY. Development of erythema nodosum in the course of oestrogen replacement therapy. Br J Dermatol 1997; 137:319-20. [PMID: 9292099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Laniyonu AA, Saifeddine M, Yang SG, Hollenberg MD. Tyrosine kinase inhibitors and the contractile action of G-protein-linked vascular agonists. Can J Physiol Pharmacol 1994; 72:1075-85. [PMID: 7842390 DOI: 10.1139/y94-150] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In a porcine coronary artery helical strip preparation, the tyrosine kinase inhibitors genistein and tyrphostin (AG82) attenuated the contractile actions of angiotensin II, arginine vasopressin, epidermal growth factor--urogastrone, noradrenaline, and prostaglandin F2 alpha, under conditions where contractions due to acetylcholine and KCl were not affected. Both genistein and tyrphostin also caused a selective inhibition of angiotensin II action in rat aorta helical strips, without affecting KCl-mediated contractions. The IC50 values for the inhibition of contraction in the porcine coronary artery were in the range of 2-5 microM for genistein and 8-15 microM for tyrphostin. Comparable IC50 values were observed for the inhibitory effects of genistein on angiotensin II and prostaglandin F2 alpha action in the rat aorta, whereas much higher tyrphostin concentrations (IC50 > or = 40 microM) were required to block angiotensin II action in this preparation. Angiotensin II caused an elevation of phosphotyrosyl protein (antiphosphotyrosine Western blot) in the porcine coronary artery, which was reversed by genistein. In addition, porcine coronary artery derived membrane and cytosolic fractions exhibited sarcoma virus related tyrosine kinase activity, which was inhibited by both genistein and tyrphostin. Our data (i) document the selective inhibition by genistein and tyrphostin of the contractile action of some, but by no means all, G-protein-linked vascular agonists in porcine and rat arterial preparations, (ii) establish the presence of sarcoma virus related tyrosine kinase activity in the porcine coronary artery, and (iii) demonstrate angiotensin II mediated increases in phosphotyrosyl protein content in porcine coronary artery tissue. These data support the hypothesis that selected G-protein-linked contractile vascular agonists may act in part via the stimulation of nonreceptor tyrosine kinases. The data also indicate the complex actions of the tyrosine kinase inhibitors, even for the same agonist acting in vascular preparations obtained from different species.
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Affiliation(s)
- A A Laniyonu
- Department of Pharmacology and Therapeutics, University of Calgary, Faculty of Medicine, Canada
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