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Wu SY, Qian RL, Ma CL, Shan Y, Wu YJ, Wu XY, Zhang JL, Zhu XB, Ji HT, Qu CY, Hou F, Liu LZ. Photoluminescence and magnetism integrated multifunctional black phosphorus probes through controllable PO bond orbital hybridization. Phys Chem Chem Phys 2021; 23:22476-22482. [PMID: 34586129 DOI: 10.1039/d1cp03155d] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biological probes with integrated photoluminescence and magnetism characteristics play a critical role in modern clinical diagnosis and surgical protocols combining fluorescence optical imaging (FOI) with magnetic resonance imaging (MRI) technology. However, traditional magnetic semiconductors can easily generate a spin splitting at the Fermi level and half-metallic electronic occupation, which will sharply reduce the radiation recombination efficiency of photogenerated carriers. To overcome this intrinsic contradiction, we propose a controllable oxidation strategy to introduce some particular PO bonds into black phosphorus nanosheets, in which the p orbital hybridization between P and O atoms not only provides some carrier recombination centers but also leads to a room-temperature spin polarization. As a result, the coexistence of photoluminescence and magnetism is realized in multifunctional black phosphorus probes with excellent biocompatibility. This work provides a new insight into integrating photoluminescence and magnetism together by intriguing atomic orbital hybridization.
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Affiliation(s)
- S Y Wu
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - R L Qian
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - C L Ma
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - Y Shan
- Key Laboratory of Advanced Functional Materials of Nanjing, Nanjing Xiaozhuang University, Nanjing 211171, China.
| | - Y J Wu
- Department of Neurology, Suzhou Science and Technology Town Hospital affiliated to Nanjing Medical University, Suzhou, 215009, China
| | - X Y Wu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China.
| | - J L Zhang
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - X B Zhu
- School of Mechano-Electronic Engineering, Suzhou Vocational University, Suzhou, Jiangsu 215104, China
| | - H T Ji
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - C Y Qu
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - F Hou
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - L Z Liu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
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Chen FC, Fei Y, Li SJ, Wang Q, Luo X, Yan J, Lu WJ, Tong P, Song WH, Zhu XB, Zhang L, Zhou HB, Zheng FW, Zhang P, Lichtenstein AL, Katsnelson MI, Yin Y, Hao N, Sun YP. Temperature-Induced Lifshitz Transition and Possible Excitonic Instability in ZrSiSe. Phys Rev Lett 2020; 124:236601. [PMID: 32603145 DOI: 10.1103/physrevlett.124.236601] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/06/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
The nodal-line semimetals have attracted immense interest due to the unique electronic structures such as the linear dispersion and the vanishing density of states as the Fermi energy approaching the nodes. Here, we report temperature-dependent transport and scanning tunneling microscopy (spectroscopy) [STM(S)] measurements on nodal-line semimetal ZrSiSe. Our experimental results and theoretical analyses consistently demonstrate that the temperature induces Lifshitz transitions at 80 and 106 K in ZrSiSe, which results in the transport anomalies at the same temperatures. More strikingly, we observe a V-shaped dip structure around Fermi energy from the STS spectrum at low temperature, which can be attributed to co-effect of the spin-orbit coupling and excitonic instability. Our observations indicate the correlation interaction may play an important role in ZrSiSe, which owns the quasi-two-dimensional electronic structures.
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Affiliation(s)
- F C Chen
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Y Fei
- Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - S J Li
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
| | - Q Wang
- University of Science and Technology of China, Hefei 230026, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - X Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - J Yan
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - W J Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - P Tong
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - W H Song
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - X B Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - L Zhang
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - H B Zhou
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - F W Zheng
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - P Zhang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
- School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China
| | - A L Lichtenstein
- Institute for Theoretical Physics, University Hamburg, Jungiusstrasse 9, D-20355 Hamburg, Germany
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia
| | - M I Katsnelson
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia
- Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, NL-6525AJ Nijmegen, The Netherlands
| | - Y Yin
- Department of Physics, Zhejiang University, Hangzhou 310027, China
- Collaborative Innovation Center of Microstructures, Nanjing University, Nanjing 210093, China
| | - Ning Hao
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Y P Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Collaborative Innovation Center of Microstructures, Nanjing University, Nanjing 210093, China
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3
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Yan J, Luo X, Gao JJ, Lv HY, Xi CY, Sun Y, Lu WJ, Tong P, Sheng ZG, Zhu XB, Song WH, Sun YP. The giant planar Hall effect and anisotropic magnetoresistance in Dirac node arcs semimetal PtSn 4. J Phys Condens Matter 2020; 32:315702. [PMID: 32235052 DOI: 10.1088/1361-648x/ab851f] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Topological semimetals (TSMs) present intriguing quantum states and have attracted much attention in recent years because of exhibiting various anomalous magneto-transport phenomena. Theoretical prediction shows that some novel phenomena, such as negative magnetoresistance (MR) and the planar Hall effect (PHE), originate from the chiral anomaly in TSMs. In this work, high-field (33 T) Shubnikov-de Haas (SdH) oscillations are obtained to reveal the topology of PtSn4. Giant PHE and anisotropic magnetoresistance (AMR) are observed in Dirac node arcs of semimetal PtSn4. First, a non-zero transverse voltage can be acquired while tilting the in-plane magnetic field. Moreover, the amplitude of PHE sharply increases atT*∼ 50 K with decreasing temperature, which is suggested to be related to the Fermi surface reconstruction observed in PtSn4. Subsequently, the field-dependent amplitudes of the PHE show an abnormal behavior around 50 K, which is thought to stem from the complex correlation between the chiral charge and electric one in PtSn4driving the system into different coupling states due to the complicated band structure. On the other hand, the relative AMR is negative and up to -98% at 8.5 T. Our work proves that the PHE measurements are a convincing transport fingerprint feature to confirm the chiral anomaly in TSMs.
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Affiliation(s)
- J Yan
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
- University of Science and Technology of China, Hefei, 230026, People's Republic of China
| | - X Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - J J Gao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
- University of Science and Technology of China, Hefei, 230026, People's Republic of China
| | - H Y Lv
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - C Y Xi
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - Y Sun
- Institute of Physical Science and Information Technology, Anhui University, Hefei, 230601, People's Republic of China
| | - W J Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - P Tong
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - Z G Sheng
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China
| | - X B Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - W H Song
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
| | - Y P Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China
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Gao XF, He HQ, Zhu XB, Xie SL, Cao Y. LncRNA SNHG20 promotes tumorigenesis and cancer stemness in glioblastoma via activating PI3K/Akt/mTOR signaling pathway. Neoplasma 2019; 66:532-542. [PMID: 30943748 DOI: 10.4149/neo_2018_180829n656] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 01/08/2019] [Indexed: 11/08/2022]
Abstract
Long noncoding RNAs (lncRNAs) play crucial roles in the development of human cancers. LncRNA small nucleolar RNA host gene 20 (SNHG20) has been reported to be an oncogene in several cancers, whereas the specific role of SNHG20 in glioblastoma is unclear. In this study, we found that SNHG20 was significantly upregulated in glioblastoma tissues and cell lines. Survival analysis suggested that high expression of SNHG20 indicated the low overall survival rate of glioblastoma patients. Subsequently, gain or loss-of-function assays were carried out to examine the effect of SNHG20 on glioblastoma cell proliferation and apoptosis. We found that SNHG20 knockdown obviously suppressed cell proliferation, increased cell apoptosis and impaired stem properties, while SNHG20 overexpression led to the opposite results. In vivo experiment demonstrated that knockdown of SNHG20 efficiently suppressed cell growth in vivo. Furthermore, western blotting demonstrated that the PI3K/Akt/mTOR signaling pathway was activated by SNHG20 in glioblastoma cells. At last, rescue assays validated that PI3K/Akt/mTOR signaling pathway involved in the glioblastoma progression mediated by SNHG20. Taken together, this study revealed that SNHG20 regulated PI3K/Akt/mTOR signaling pathway to promote tumorigenesis and stemness of glioblastoma.
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Affiliation(s)
- X F Gao
- Department of Neurosurgery, The First Hospital of Jilin University, Jilin, China
| | - H Q He
- Intensive Medicine Department, The First Hospital of Jilin University, Jilin, China
| | - X B Zhu
- Department of Neurosurgery, The First Hospital of Jilin University, Jilin, China
| | - S L Xie
- Department of Hepatobiliary Surgery, The First Hospital of Jilin University, Jilin, China
| | - Y Cao
- Clinical Laboratory, The First Hospital of Jilin University, Jilin, China
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5
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Pan C, Liu HD, Gong Z, Yu X, Hou XB, Xie DD, Zhu XB, Li HW, Tang JY, Xu YF, Yu JQ, Zhang LY, Fang H, Xiao KH, Chen YG, Wang JY, Pang Q, Chen W, Sun JP. Cadmium is a potent inhibitor of PPM phosphatases and targets the M1 binding site. Sci Rep 2014; 3:2333. [PMID: 23903585 PMCID: PMC3730172 DOI: 10.1038/srep02333] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/24/2013] [Indexed: 11/16/2022] Open
Abstract
The heavy metal cadmium is a non-degradable pollutant. By screening the effects of a panel of metal ions on the phosphatase activity, we unexpectedly identified cadmium as a potent inhibitor of PPM1A and PPM1G. In contrast, low micromolar concentrations of cadmium did not inhibit PP1 or tyrosine phosphatases. Kinetic studies revealed that cadmium inhibits PPM phosphatases through the M1 metal ion binding site. In particular, the negative charged D441 in PPM1G specific recognized cadmium. Our results suggest that cadmium is likely a potent inhibitor of most PPM family members except for PHLPPs. Furthermore, we demonstrated that cadmium inhibits PPM1A-regulated MAPK signaling and PPM1G-regulated AKT signaling potently in vivo. Cadmium reversed PPM1A-induced cell cycle arrest and cadmium insensitive PPM1A mutant rescued cadmium induced cell death. Taken together, these findings provide a better understanding of the effects of the toxicity of cadmium in the contexts of human physiology and pathology.
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Affiliation(s)
- Chang Pan
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong 250012, China
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6
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Abstract
BACKGROUND Henoch Schonlein Purpura (HSP) is a systemic vasculitic disease which is common in children. It is very important to understand the clinical features of this disease for doctors and nurses. OBJECTIVES To study the clinical characteristics of HSP in children. METHODS Collect the clinical data of the HSP children, and analyze the clinical characteristics of these HSP patients. RESULTS The ratio of M:F was 1.9:1. The mean age was 6.6 ± 1.6 years. The typical onset seasons were spring, winter and autumn. Infection and food allergy were the main etiological factors. The first symptom was skin purpura and these purpura mainly concentrated the lower extremities and buttocks. The dominant digestive clinical features were abdominal pains and vomiting. The knee joint and ankle joint were most frequently affected. The typical kidney symptoms were microscopic hematuria and albuminuria. An increased ESR was reported in 68 patients (56.7%). Serum C3 decreased in 13 cases (10.8%). ASO titer was higher in 57 children (47.5%). CONCLUSION There were gender, season and area differences for the HSP patients. The etiological factors were diverse. HSP patients could have various clinical symptoms and rare complications.
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Affiliation(s)
- O Chen
- Department of Pediatrics, Qilu Hospital, Shandong University, #107 West Wenhua Road, Jinan 250012, China
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7
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Yu HF, Zhu XB, Peng ZH, Tian Y, Cui DJ, Chen GH, Zheng DN, Jing XN, Lu L, Zhao SP, Han S. Quantum phase diffusion in a small underdamped Josephson junction. Phys Rev Lett 2011; 107:067004. [PMID: 21902362 DOI: 10.1103/physrevlett.107.067004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Indexed: 05/27/2023]
Abstract
Quantum phase diffusion in a small underdamped Nb/AlO(x)/Nb junction (∼0.4 μm(2)) is demonstrated in a wide temperature range of 25-140 mK where macroscopic quantum tunneling (MQT) is the dominant escape mechanism. We propose a two-step transition model to describe the switching process in which the escape rate out of the potential well and the transition rate from phase diffusion to the running state are considered. The transition rate extracted from the experimental switching current distribution follows the predicted Arrhenius law in the thermal regime but is greatly enhanced when MQT becomes dominant.
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Affiliation(s)
- H F Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, China
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Luo X, Sun YP, Hu L, Wang BS, Lu WJ, Zhu XB, Yang ZR, Song WH. Observation of the large magnetocaloric effect in an orbital-spin-coupled system MnV(2)O(4). J Phys Condens Matter 2009; 21:436010. [PMID: 21832456 DOI: 10.1088/0953-8984/21/43/436010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The magnetocaloric effect (MCE) in an orbital-spin-coupled spinel vanadate MnV(2)O(4) is investigated by magnetization measurement. MnV(2)O(4) has ferrimagnetic ordering occurring at T(C) = 57 K. The maximum magnetic entropy change reaches 14.8 and 24.0 J kg(-1) K(-1) for field changes of 0-2 and 0-4 T, respectively. The maximum adiabatic temperature is about 2.9 K for a magnetic field change of 2 T. Except for the spin entropy change, the observed giant MCE is suggested to be related to the orbital entropy change due to the change of the orbital state of V(3+) induced by an applied magnetic field around T(C).
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Affiliation(s)
- X Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
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Cheng YL, Dai JM, Zhu XB, Wu DJ, Yang ZR, Sun YP. Enhanced Microwave Absorption Properties of Intrinsically Core/shell Structured La(0.6)Sr(0.4)MnO(3) Nanoparticles. Nanoscale Res Lett 2009; 4:1153-1158. [PMID: 20596374 PMCID: PMC2894104 DOI: 10.1007/s11671-009-9374-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 06/04/2009] [Indexed: 05/15/2023]
Abstract
The intrinsically core/shell structured La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of -41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than -10 dB is obtained in the 5.5-11.3 GHz range for absorber thicknesses of 1.5-2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9374-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- YL Cheng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
| | - JM Dai
- School of Physics and Electronic Information, Huaibei Coal Industry Teachers College, 235000, Huaibei, People’s Republic of China
| | - XB Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
| | - DJ Wu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
| | - ZR Yang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
| | - YP Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
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10
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Abstract
The critical behavior of the double perovskite La(2)NiMnO(6) was investigated by measurement of the magnetization around the Curie temperature T(C). The magnetic data were analyzed in the critical region using the Kouvel-Fisher method to yield the critical exponents of β = 0.408 ± 0.011 with T(C) = 270.50 (from the temperature dependence of the spontaneous magnetization below T(C)) and γ = 1.295 ± 0.015 with T(C) = 271.10 (from the temperature dependence of the inverse initial susceptibility above T(C)). The critical magnetization isotherm M(T(C),H) gives δ = 4.139 ± 0.090. The critical exponents obtained by this method obey the Widom scaling relation δ = 1+γ/β, implying the critical exponents are reliable. The values of critical exponents are close to those predicted by the three-dimensional (3D) Heisenberg model with short-range interactions.
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Affiliation(s)
- X Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
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11
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Li WW, Zhou WZ, Zhang YZ, Wang J, Zhu XB. Flocculation behavior and mechanism of an exopolysaccharide from the deep-sea psychrophilic bacterium Pseudoalteromonas sp. SM9913. Bioresour Technol 2008; 99:6893-6899. [PMID: 18353634 DOI: 10.1016/j.biortech.2008.01.050] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 01/14/2008] [Accepted: 01/20/2008] [Indexed: 05/26/2023]
Abstract
Flocculation behavior and mechanism of the exopolysaccharide secreted by Pseudoalteromonas sp. SM9913 (EPS SM9913), a psychrophilic bacterium isolated from 1855m deep-sea sediment, has been studied in this paper. EPS SM9913 showed a peak flocculating activity of 49.3 in 1g/L kaolin suspension with 4.55mmol/L CaCl2 and the optimum pH range of 5-8. It appears that the flocculating activity of EPS SM9913 was stimulated by Ca2+ and Fe2+. This study found that EPS SM9913 showed a better flocculation performance than Al2(SO4)3 at salinity of 5-100 per thousand or temperatures of 5-15 degrees C. In addition, this EPS was effective to flocculate several other suspended solids. The measured zeta-potentials, the size of flocs formed during the flocculation process and the surface profile of flocs revealed by scan electron micrograph suggest that bridging is the main flocculation mechanism of the studied EPS. Deacetylation of EPS SM9913 resulted in a significant decrease in its flocculating activity indicating that the large number of acetyl groups in EPS SM9913 played an important role in its flocculation performance.
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Affiliation(s)
- W W Li
- School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
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12
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Tay TW, Andriana BB, Ishii M, Choi EK, Zhu XB, Alam MS, Tsunekawa N, Kanai Y, Kurohmaru M. Phagocytosis plays an important role in clearing dead cells caused by mono(2-ethylhexyl) phthalate administration. Tissue Cell 2007; 39:241-6. [PMID: 17590400 DOI: 10.1016/j.tice.2007.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 04/19/2007] [Accepted: 04/26/2007] [Indexed: 11/22/2022]
Abstract
The role of phagocytosis in eliminating apoptotic spermatogenic cells caused by mono(2-ethylhexyl) phthalate (MEHP) was studied. Twenty-one-day-old C57Bl/6N male mice were given a single dose of 800 mg/kg MEHP in corn oil by oral gavage and sacrificed at 1, 3, 5, 7 and 9 days after initial exposure. At the same time, the role of phagocytosis in MEHP related apoptosis was examined using microinjection of annexin V into the seminiferous tubules of living mice. Results showed that mice treated with MEHP had a lower rate of testis weight gain (lower regression line) and a significant TUNEL-positive spermatogenic cell number compared to control. However, this incident was reversible, and the number of TUNEL-positive cells returned to normal after 9 days. Mice microinjected with annexin V and later treated with MEHP showed a large amount of TUNEL-positive cells compared to mice treated with MEHP only. This clearly proves that phagocytosis plays an efficient and highly important role in eliminating dead cells in the injured testis of mice treated with MEHP.
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Affiliation(s)
- T W Tay
- Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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13
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Li SX, Qiu W, Han S, Wei YF, Zhu XB, Gu CZ, Zhao SP, Wang HB. Observation of macroscopic quantum tunneling in a single Bi2Sr2CaCu2O8+delta surface intrinsic Josephson junction. Phys Rev Lett 2007; 99:037002. [PMID: 17678315 DOI: 10.1103/physrevlett.99.037002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Indexed: 05/16/2023]
Abstract
We report on the first unambiguous observation of macroscopic quantum tunneling (MQT) in a single submicron Bi(2)Sr(2)CaCu(2)O(8+delta) surface intrinsic Josephson junction (IJJ) by measuring its temperature-dependent switching current distribution. All relevant junction parameters were determined in situ in the classical regime and were used to predict the behavior of the IJJ in the quantum regime via MQT theory. Experimental results agree quantitatively with the theoretical predictions, thus confirming the MQT picture. Furthermore, the data also indicate that the surface IJJ, where the current flows along the c axis of the crystal, has the conventional sinphi current-phase relationship.
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Affiliation(s)
- Shao-Xiong Li
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA
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Abstract
Yellow birch seedlings (Betula alleghaniensis Britt.) that had lost more than 90% of their stem hydraulic conductivity during ambient winter temperatures were exposed to 0 and 20 days of a simulated winter thaw followed by a 48-h freezing treatment at 0, -5, -10, -20 and -30 degrees C. After measuring freezing injury to shoots and roots, the seedlings were placed in a greenhouse where recovery of xylem conductivity and new growth were measured. Shoot xylem cavitation was measured as percent loss of hydraulic conductivity. Shoot freezing injury was assessed by electrolyte leakage (EL) and root freezing injury was assessed by EL and triphenyl tetrazolium chloride reduction. Seedlings pretreated with thaw had higher stem water contents and suffered more freezing damage to roots and shoots (at -20 and -30 degrees C, respectively) than unthawed seedlings. After 3 weeks in a greenhouse, seedlings from the 0, -5 and -10 degrees C freezing treatments showed complete recovery of xylem conductivity, with substantially increased stem water contents. Poor recovery of hydraulic conductivity was observed only in seedlings that were subjected to freezing treatments at -20 and -30 degrees C, regardless of thaw treatment. Of these embolized seedlings, however, only those not previously thawed showed recovery of hydraulic conductivity or regained stem water content after 9 weeks in the greenhouse. Shoot dieback, bud burst and length of new shoots were significantly related to the extent of stem xylem cavitation and freezing injury. We conclude that (1) the simulated winter thaw predisposed yellow birch seedlings to freezing damage in shoots and roots by dehardening tissues and increasing their water content; (2) root freezing damage in turn affected the seedlings' ability to refill embolized stem xylem, resulting in considerable residual xylem embolism after spring refilling; (3) further recovery of stem xylem conductivity was attributable to growth of new vessels; (4) and the permanent residual embolism, together with root and shoot freezing injury, caused increased dieback, bud mortality and reduced growth of new shoots.
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Affiliation(s)
- R M Cox
- Canadian Forest Service-Atlantic Forestry Centre, Fredericton, NB E3B 5P7, Canada.
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Abstract
One-year-old, cold-hardened, container-grown yellow birch (Betula alleghaniensis Britt.) seedlings were exposed to cold treatments after being pretreated with a simulated winter thaw. Freezing injury to roots and shoots was assessed by relative electrolyte leakage and triphenyltetrazolium chloride reduction. Growth characteristics were also determined after 60 days under greenhouse conditions. Relative electrolyte leakage and triphenyltetrazolium chloride reduction measurements showed that roots became increasingly damaged with decreasing cold-treatment temperatures. However, plants pretreated with thaws showed significantly lower stem increment, shoot length, and leaf area in response to the cold temperatures than did the unthawed plants. Variation in these growth parameters was also significantly correlated with both root and shoot freezing injury parameters. Cold hardiness under different thaw pretreatments was assessed using the highest freezing temperature that caused significant injury, referred to as the critical temperature. For seedlings without the thaw pretreatment, shoot and root critical temperatures were estimated as 52.5 and 23.8°C, respectively. Following 12 days of thaw, these temperatures increased to 24.08°C for shoots and 13°C for roots. Twelve days of thaw, or growing degree-day (>4°C) accumulations greater than 66 during a thaw, could sufficiently deharden roots and shoots such that they would be susceptible to freezing damage at ambient temperatures commonly encountered in the Canadian Maritimes. We also observed that root pressure declined significantly with increasing root freezing injury. Sufficient root pressure is required for springtime refilling of xylem embolisms caused by winter cavitation of the vessels in this species. Weak root pressure caused by freezing injury would represent a risk of shoot dieback and tree decline due to the remaining embolisms reducing water flow to the developing foliage. The rapid reduction of shoot cold hardiness may also indicate the threat of late-spring frosts to this species. These induced changes are especially important under climate change scenarios that suggest increases in winter temperatures and changes in seasonality in eastern Canada.Key words: climate change, cold hardiness, electrolyte leakage, growth, root pressure, TTC reduction.
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Abstract
Three new hederagenin-based acetylated saponins isolated from the fruits of Gliricidia sepium, were identified by chemical and spectroscopic methods as hederagenin-3-O- (4-O-acetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2 ) -alpha-L-arabinopyranoside, hederagenin-3-O-(3,4-di-O-acetyl-beta-D- xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha- arabinopyranoside and hederagenin-3-O-(3,4-di-O-acetyl-alpha-L- arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L- arabinopyranoside.
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Affiliation(s)
- K Kojima
- Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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Chen SG, Zhang CK, Zhang DM, Zhang CL, Zhang WH, Zhu XB, Zhang YS, Cong XF, Zen QY, Fan LL, Zhou YP, Liu WH. [Use of coronary artery occluder in experimental myocardial ischemia and infarction in conscious dogs]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1982; 4:147-51. [PMID: 6215137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Chen SG, Zhang JG, Zhang YS, Cong XF, Zhang CL, Zhang WH, Zhu XB, Gao RQ. [Estimation of the myocardial infarct size in conscious dogs (author's transl)]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1982; 4:45-9. [PMID: 6461432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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