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Ding S, Garofalo AM, Wang HQ, Weisberg DB, Li ZY, Jian X, Eldon D, Victor BS, Marinoni A, Hu QM, Carvalho IS, Odstrčil T, Wang L, Hyatt AW, Osborne TH, Gong XZ, Qian JP, Huang J, McClenaghan J, Holcomb CT, Hanson JM. A high-density and high-confinement tokamak plasma regime for fusion energy. Nature 2024:10.1038/s41586-024-07313-3. [PMID: 38658758 DOI: 10.1038/s41586-024-07313-3] [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] [Received: 07/25/2023] [Accepted: 03/14/2024] [Indexed: 04/26/2024]
Abstract
The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.
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Affiliation(s)
- S Ding
- General Atomics, San Diego, CA, USA.
| | | | - H Q Wang
- General Atomics, San Diego, CA, USA
| | | | - Z Y Li
- General Atomics, San Diego, CA, USA
| | - X Jian
- General Atomics, San Diego, CA, USA
| | - D Eldon
- General Atomics, San Diego, CA, USA
| | - B S Victor
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - A Marinoni
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Q M Hu
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, USA
| | | | | | - L Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | | | - X Z Gong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J P Qian
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | - C T Holcomb
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - J M Hanson
- Department of Applied Mathematics and Applied Physics, Columbia University, New York, NY, USA
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2
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Jian X, Chen J, Ding S, Garofalo A, Gong X, Holland C, Huang J, Chan VS, Qin X, Yu G, Ma RR, Du X, Hong R, Staebler G, Wang H, Yan Z, Bass E, Brower D, Ding W, Orlov D. Experimental Validation of a Kinetic Ballooning Mode in High-Performance High-Bootstrap Current Fraction Fusion Plasmas. Phys Rev Lett 2023; 131:145101. [PMID: 37862644 DOI: 10.1103/physrevlett.131.145101] [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] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 07/09/2023] [Accepted: 08/21/2023] [Indexed: 10/22/2023]
Abstract
We report the observation of a set of coherent high frequency electromagnetic fluctuations that leads to a turbulence induced self-regulating phenomenon in the DIII-D high bootstrap current fraction plasma. The fluctuations have frequency of 130-220 kHz, the poloidal wavelength and phase velocity are 16-30 m^{-1} and ∼30 km/s, respectively, in the outboard midplane with the estimated toroidal mode number n∼5-9. The fluctuations are located in the internal transport barrier (ITB) region at large radius and are experimentally validated to be kinetic ballooning modes (KBM). Quasilinear estimation predicts the KBM to be able to drive experimental particle flux and non-negligible thermal flux, suggesting its significant role in regulating the ITB saturation.
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Affiliation(s)
- X Jian
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - J Chen
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - S Ding
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - A Garofalo
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - X Gong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - C Holland
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - V S Chan
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - X Qin
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - G Yu
- University of California at Davis, Davis, California 95616, USA
| | - R R Ma
- Southwestern Institute of Physics, P.O. Box 432 Chengdu 610041, China
| | - X Du
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R Hong
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - G Staebler
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - H Wang
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - Z Yan
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - E Bass
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - D Brower
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - W Ding
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - D Orlov
- University of California, San Diego, La Jolla, California 92093-0417, USA
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3
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Feng S, Cai X, Li Y, Jian X, Zhang L, Li B. Retraction Note: Tripartite motif-containing 14 (TRIM14) promotes epithelial-mesenchymal transition via ZEB2 in glioblastoma cells. J Exp Clin Cancer Res 2023; 42:74. [PMID: 36978192 PMCID: PMC10045949 DOI: 10.1186/s13046-023-02646-9] [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: 03/30/2023] Open
Abstract
This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s13046-019-1070-x.
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Affiliation(s)
- Shuang Feng
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Xiaomin Cai
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yangyang Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaoguang Jian
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Linxin Zhang
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Bin Li
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China.
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Xiao S, Deng F, Xie T, Yang S, Jian X, Hong D. POS-198 CLINICAL EFFECT OF PARATHYROIDECTOMY AND AUTOLOGOUS HOMOGENATE TRANSPLANTATION IN THE TREATMENT OF SECONDARY HYPERPARATHYROIDISM. Kidney Int Rep 2022. [DOI: 10.1016/j.ekir.2022.01.216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Du XD, Hong RJ, Heidbrink WW, Jian X, Wang H, Eidietis NW, Van Zeeland MA, Austin ME, Liu Y, Crocker NA, Rhodes TL, Särkimäki K, Snicker A, Wu W, Knolker M. Multiscale Chirping Modes Driven by Thermal Ions in a Plasma with Reactor-Relevant Ion Temperature. Phys Rev Lett 2021; 127:025001. [PMID: 34296897 DOI: 10.1103/physrevlett.127.025001] [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] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/02/2021] [Accepted: 06/09/2021] [Indexed: 06/13/2023]
Abstract
A thermal ion driven bursting instability with rapid frequency chirping, considered as an Alfvénic ion temperature gradient mode, has been observed in plasmas having reactor-relevant temperature in the DIII-D tokamak. The modes are excited over a wide spatial range from macroscopic device size to microturbulence size and the perturbation energy propagates across multiple spatial scales. The radial mode structure is able to expand from local to global in ∼0.1 ms and it causes magnetic topology changes in the plasma edge, which can lead to a minor disruption event. Since the mode is typically observed in the high ion temperature ≳10 keV and high-β plasma regime, the manifestation of the mode in future reactors should be studied with development of mitigation strategies, if needed. This is the first observation of destabilization of the Alfvén continuum caused by the compressibility of ions with reactor-relevant ion temperature.
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Affiliation(s)
- X D Du
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R J Hong
- University of California, Los Angeles, California 90095, USA
| | - W W Heidbrink
- University of California, Irvine, California 92697, USA
| | - X Jian
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - H Wang
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - N W Eidietis
- University of California, Los Angeles, California 90095, USA
| | - M A Van Zeeland
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M E Austin
- University of Texas-Austin, Austin, Texas 78712, USA
| | - Y Liu
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - N A Crocker
- University of California, Los Angeles, California 90095, USA
| | - T L Rhodes
- University of California, Los Angeles, California 90095, USA
| | - K Särkimäki
- Department of Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - A Snicker
- Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 AALTO, Espoo, Finland
| | - W Wu
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M Knolker
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
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Wang XY, Jian X, Sun BQ, Ge XS, Huang FJ, Chen YQ. LncRNA ROR1-AS1 promotes colon cancer cell proliferation by suppressing the expression of DUSP5/CDKN1A. Eur Rev Med Pharmacol Sci 2021; 24:1116-1125. [PMID: 32096171 DOI: 10.26355/eurrev_202002_20162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The purpose of this study was to explore the possible role of ROR1-AS1 in the pathogenesis of colon cancer and the underlying mechanism. PATIENTS AND METHODS The expression levels of ROR1-AS1 in 75 colon cancer tissue samples and adjacent ones, as well as in cell lines were examined by quantitative Polymerase Chain Reaction (qPCR). Then, ROR1-AS1 overexpression plasmid and siRNA were transfected into colon cancer cells using liposome method. After that, Cell Counting Kit-8 (CCK-8) and plate colony formation assays were conducted to analyze cell proliferation, while flow cytometry was applied for the analysis of cell cycle and apoptosis. At last, the mechanism of action of ROR1-AS1 was further explored by nuclear separation, RNA binding protein immunoprecipitation (RIP) and chromatin immunoprecipitation (CHIP) assays. RESULTS ROR1-AS1 level in colon cancer tissues was remarkably higher than that in normal tissues, and the expression in tumors of stage III and IV was remarkably higher than those of stage I and II. Meanwhile, tumors with diameters more than 5 cm had a higher ROR1-AS1 expression than those less than 5 cm. After transfection with ROR1-AS1 overexpression plasmid, the cell proliferation ability was enhanced, the G0/G1 phase time of cell cycle was shortened, and the apoptosis was suppressed. However, the opposite result was observed after ROR1-AS1 was downregulated. Furthermore, RIP showed that ROR1-AS1 can bind to enhancer of zeste homolog 2 (EZH2) and inhibit the expression of DUSP5, and thus be engaged in the proliferation and apoptosis of colon cancer cells. CONCLUSIONS ROR1-AS1 is highly expressed either in colon cancer tissues or in cell lines, which is able to enhance cell proliferation, accelerate cell cycle, and inhibit cell apoptosis. The mechanism of ROR1-AS1 to participate in the development of colon cancer may be the downregulation of DUSP5 via combination with EZH2.
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Affiliation(s)
- X-Y Wang
- Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China.
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Yongxia Z, Jian X, Suyuan H, Aixin N, Lihong Z. Isolation and characterization of ergosterol from Monascus anka for anti-lipid peroxidation properties. J Mycol Med 2020; 30:101038. [PMID: 33069573 DOI: 10.1016/j.mycmed.2020.101038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/02/2023]
Abstract
Unbalanced lipid peroxidation damages the human body, and is associated with the formation of tumors, infections, inflammations, autoimmune diseases, and cardiovascular and cerebrovascular diseases. However, food and drugs that contain anti-lipid peroxidation active substances, can help to protect against these negative health impacts. We observed lipid peroxidation inhibition in the metabolites of fermented Monascus anka, in media with Dendrobium nobile Lindl. The anti-lipid peroxidation ability of the extracts was strongest in ethyl acetate, so this was selected for further purifications. A crystal with strong antioxidant properties was obtained by column chromatography. Based on its spectroscopic analysis by Electron Bombardment Ion Source and Mass Spectrometry (EI-MS), 1H-Nuclear Magnetic Resonance (1H-NMR), and 13C-Nuclear Magnetic Resonance (13C-NMR), the isolated crystal was identified as ergosterol. The inhibition rates of the lipid peroxide due to the ergosterol were 57.42%, at 2μg/mL in vitro. Simultaneously, the survival rates of the damaged cells treated with 0.3mmol/L H2O2 were significantly improved with the ergosterol, up to 43.88% (200μg/mL) and 46.64% (400μg/mL), compared to 36.47% for the injured cells. The survival rate of the cells was 78.32% (400μg/mL), with ergosterol as a prevention. Cell injury can increase the level of intracellular ROS, but its levels in the damaged cells were reduced after the ergosterol treatments, and the reduction increased with the increasing concentrations. A 400μg/mL concentration resulted in the lowest fluorescence intensity; 33421.11 AU below the normal level. Ergosterol significantly reduced the ROS levels, to reduce the cell damage. Ergosterol from Monascus anka was thus found to have strong anti-lipid peroxidation and antioxidant capabilities, and the ability to protect and repair damaged cells. It may consequently serve as a potential natural antioxidant and will play an important role in human anti-lipid peroxide.
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Affiliation(s)
- Z Yongxia
- Department of Wine Engineering, Moutai Institute, Renhuai, Guizhou, China
| | - X Jian
- Department of Medical Genetics, Zunyi Medical University, Zunyi, Guizhou, China
| | - H Suyuan
- College of Life Sciences, Guizhou University, Guiyang, Guizhou, China
| | - N Aixin
- College of Life Sciences, Guizhou University, Guiyang, Guizhou, China
| | - Z Lihong
- College of Life Sciences, Guizhou University, Guiyang, Guizhou, China.
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8
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Wang XY, Wang L, Xu PC, Huang FJ, Jian X, Wei ZC, Chen YQ. LINC01605 promotes the proliferation of laryngeal squamous cell carcinoma through targeting miR-493-3p. Eur Rev Med Pharmacol Sci 2020; 23:10379-10386. [PMID: 31841192 DOI: 10.26355/eurrev_201912_19677] [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] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The purpose of this study was to elucidate the potential influence of LINC01605 on the progression of laryngeal squamous cell carcinoma (LSCC) and the underlying mechanism. PATIENTS AND METHODS LINC01605 and microRNA-493-3p (miR-493-3p) levels in normal laryngeal tissues, LSCC tissues, and paired paracancerous tissues were detected. Regulatory effects of LINC01605 on proliferative ability and apoptosis in HEp-2 and AMC-HN-8 cells were assessed. Besides, the interaction between LINC01605 and miR-493-3p was evaluated by Dual-Luciferase reporter gene assay and Spearman's rank correlation analysis. Finally, rescue experiments were conducted to clarify the role of LINC01605/miR-493-3p axis in the progression of LSCC. RESULTS LINC01605 was upregulated and miR-493-3p was downregulated in LSCC tissues. Knockdown of LINC01605 inhibited proliferative ability, and stimulated apoptosis in HEp-2 and AMC-HN-8 cells. Moreover, LINC01605 directly bound to miR-493-3p, and the former negatively regulated the level of the latter. In addition, miR-493-3p was able to reverse the regulatory effect of LINC01605 on proliferative ability in LSCC. CONCLUSIONS LINC01605 is upregulated in LSCC tissues, and it promotes the malignant progression of LSCC via targeting miR-493-3p.
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Affiliation(s)
- X-Y Wang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China.
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Jian X, Chunhong X, Hongyan C, Huijun L, Haizhong Y, Jianfen Y. Effects of Chinaberry Tree Extract on Proliferation, Apoptosis, Migration and Cell Cycle Distribution of Human Breast Cancer Cells. Indian J Pharm Sci 2020. [DOI: 10.36468/pharmaceutical-sciences.spl.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Jian X, Holland C, Candy J, Belli E, Chan V, Garofalo AM, Ding S. Role of Microtearing Turbulence in DIII-D High Bootstrap Current Fraction Plasmas. Phys Rev Lett 2019; 123:225002. [PMID: 31868395 DOI: 10.1103/physrevlett.123.225002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/03/2019] [Indexed: 06/10/2023]
Abstract
We report on the first direct comparisons of microtearing turbulence simulations to experimental measurements in a representative high bootstrap current fraction (f_{BS}) plasma. Previous studies of high f_{BS} plasmas carried out in DIII-D with large radius internal transport barriers (ITBs) have found that, while the ion energy transport is accurately reproduced by neoclassical theory, the electron transport remains anomalous and not well described by existing quasilinear transport models. A key feature of these plasmas is the large value of the normalized pressure gradient, which is shown to completely stabilize conventional drift-wave and kinetic ballooning mode instabilities in the ITB, but destabilizes the microtearing mode. Nonlinear gyrokinetic simulations of the ITB region performed with the cgyro code demonstrate that the microtearing modes are robustly unstable and capable of driving electron energy transport levels comparable to experimental levels for input parameters consistent with the experimental measurements. These simulations uniformly predict that the microtearing mode fluctuation and flux spectra extend to significantly shorter wavelengths than the range of linear instability, representing significantly different nonlinear dynamics and saturation mechanisms than conventional drift-wave turbulence, which is also consistent with the fundamental tearing nature of the instability. The predicted transport levels are found to be most sensitive to the magnetic shear, rather than the temperature gradients more typically identified as driving turbulent plasma transport.
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Affiliation(s)
- X Jian
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - C Holland
- University of California, San Diego, La Jolla, California 92093-0417, USA
| | - J Candy
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - E Belli
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - V Chan
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - A M Garofalo
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - S Ding
- Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui, 230031, China
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Feng S, Cai X, Li Y, Jian X, Zhang L, Li B. Tripartite motif-containing 14 (TRIM14) promotes epithelial-mesenchymal transition via ZEB2 in glioblastoma cells. J Exp Clin Cancer Res 2019; 38:57. [PMID: 30728039 PMCID: PMC6364431 DOI: 10.1186/s13046-019-1070-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/30/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Several members of the tripartite motif-containing (TRIM) protein family have been reported to serve as vital regulators of tumorigenesis. Recent studies have demonstrated an oncogenic role of TRIM 14 in multiple human cancers; however, the importance of this protein in glioblastoma remains to be elucidated. METHODS The expression levels of TRIM14 were analyzed in a series of database and were examined in a variety of glioblastoma cell lines. Two independent TRIM14 shRNA were transfected into LN229 and U251 cells, and the effect of TRIM14 depletion was confirmed. Transwell assay and wound healing assay assay were carried out to assess the effect of TRIM14 depletion on glioblastoma cell invasion and migration. Western blotting was performed to screen the downstream gene of TRIM14. The stability analysis and Ubiquitylation assays and Orthotopic xenograft studies were also performed to investigate the role of TRIM14 and the relationship with downstream gene. Human glioblastoma tissues were obtained and immunohistochemical staining were carried out to confirm the clinical significance of TRIM14. RESULTS In this study, we showed that TRIM14 was upregulated in human glioblastoma specimens and cell lines, and correlated with glioblastoma progression and shorter patient survival times. Functional experiments showed that decreased TRIM14 expression reduced glioblastoma cell invasion and migration. Furthermore, we identified that zinc finger E-box binding homeobox 2 (ZEB2), a transcription factor involved in epithelial-mesenchymal transition, is a downstream target of TRIM14. Further investigation revealed that TRIM14 inactivation significantly facilitated ZEB2 ubiquitination and proteasomal degradation, which led to aggressive invasion and migration. Our findings provide insight into the specific biological role of TRIM14 in tumor invasion. CONCLUSIONS Our findings provide insight into the specific biological role of TRIM14 in tumor invasion, and suggest that targeting the TRIM14/ZEB2 axis might be a novel therapeutic approach for blocking glioblastoma.
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Affiliation(s)
- Shuang Feng
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Xiaomin Cai
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yangyang Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaoguang Jian
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Linxin Zhang
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Bin Li
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China.
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12
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Ma W, Ji Y, Qi L, Guo X, Jian X, Liu P. Breast cancer Ki67 expression prediction by DCE-MRI radiomics features. Clin Radiol 2018; 73:909.e1-909.e5. [PMID: 29970244 DOI: 10.1016/j.crad.2018.05.027] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/24/2018] [Indexed: 01/04/2023]
Abstract
AIM To investigate whether quantitative radiomics features extracted from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are associated with Ki67 expression of breast cancer. MATERIALS AND METHODS This institutional review board-approved retrospective study comprised 377 Chinese women who were diagnosed with invasive breast cancer in 2015. This cohort included 53 low-Ki67 expression (Ki67 proliferation index less than 14%) and 324 cases with high-Ki67 expression (Ki67 proliferation index more than 14%). A binary-classification of low-versus high- Ki67 expression was performed. A set of 56 quantitative radiomics features, including morphological, greyscale statistic, and texture features, were extracted from the segmented lesion area. Three machine learning classification methods, including naive Bayes, k-nearest neighbour and support vector machine, were employed for the classification and the least absolute shrink age and selection operator (LASSO) method was used to select most predictive features set for the classifiers. Classification performance was evaluated by the area under receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. RESULES The model that used naive Bayes classification method achieved the best performance than the other two methods, yielding 0.773 AUC, 0.757 accuracy, 0.777 sensitivity and 0.769 specificity. Three most predictive features, i.e., contrast, entropy and line likeness, were selected by the LASSO method and showed a statistical significance (p<0.05) in the classification. CONCLUSION The present study showed that quantitative radiomics imaging features of breast tumour extracted from DCE-MRI are associated with breast cancer Ki67 expression. Future larger studies are needed in order to further evaluate the findings.
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Affiliation(s)
- W Ma
- Department of Breast Imaging, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin 300060, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China; Department of Biomedical and Engineering, Tianjin Medical University, Tianjin 300070, China
| | - Y Ji
- Department of Breast Imaging, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin 300060, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - L Qi
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - X Guo
- Department of Breast Imaging, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin 300060, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - X Jian
- Department of Biomedical and Engineering, Tianjin Medical University, Tianjin 300070, China.
| | - P Liu
- Department of Breast Imaging, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin 300060, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China.
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Jian X, Yang QL, Xiao S, Jing Z, Hu SD. The effects of a sodium-glucose cotransporter 2 inhibitor on diabetic nephropathy and serum oxidized low-density lipoprotein levels. Eur Rev Med Pharmacol Sci 2018; 22:3994-3999. [PMID: 29949175 DOI: 10.26355/eurrev_201806_15284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE To investigate the effect of an SGLT-2 inhibitor on diabetic nephropathy and serum oxidized low-density lipoprotein (ox-LDL) levels. PATIENTS AND METHODS We randomly divided 126 patients with diabetic nephropathy into the treatment group and control group. The 63 patients in the treatment group received an SGLT-2 inhibitor in addition to routine insulin therapy, while the control group received only insulin to control blood glucose. All laboratory indexes were recorded before and after treatment with the SGLT-2 inhibitor. The prognosis of patients was followed-up. Simultaneously, 63 healthy and BMI-matched in-patients were selected as the healthy control group. Peripheral blood samples were collected from all groups, and the levels of ROS were measured by ELISA. RESULTS Renal function indexes such as urinary protein, creatinine, blood urea nitrogen, and glomerular filtration rate (GFR) were significantly higher with SGLT-2 inhibitor treatment compared with the control group (p<0.05). The fasting blood glucose level was not significantly increased before or after treatment (p>0.05). The levels of ROS in peripheral blood were significantly lower in the treatment group than in the control group (p<0.05). Observation at the 1-year follow-up showed that the average GFR was significantly higher in the treatment group than in the control group. Furthermore, the proportion of patients with stage 1-3 chronic kidney disease was significantly higher in the treatment group than in the control group (p<0.05). CONCLUSIONS The SGLT-2 inhibitor had a good therapeutic effect on renal function in patients with diabetic nephropathy, without having effects on fasting blood glucose. Additionally, it significantly delayed the progression of nephropathy. It is therefore worth clinical promotion.
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Affiliation(s)
- X Jian
- Department of Nephrology, Sichuan Mianyang 404 Hospital, Mianyang, China.
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Qin L, Xifa S, Dawei X, Yangjing X, Kangting J, Jian X, Suqin Z. Role of hypoxia-inducible factor in diabetic myocardial hypertrophy. TROP J PHARM RES 2016. [DOI: 10.4314/tjpr.v15i11.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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15
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Chen J, Jiang C, Li N, Gao Z, Chen L, Wu X, Chen X, Jian X. Bipaddled split pectoralis major myocutaneous flaps for single-stage immediate reconstruction of oral mucosal defects combined with neck defects in recurrent oral cancer patients. Int J Oral Maxillofac Surg 2015. [DOI: 10.1016/j.ijom.2015.08.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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16
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Chen J, Jiang C, Min A, Ren H, Gao Z, Jian X. Chimerical DCIAPF for simultaneous reconstruction of composite oromandibular defects. Int J Oral Maxillofac Surg 2015. [DOI: 10.1016/j.ijom.2015.08.618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Chen J, Zhuang G, Li Q, Liu Y, Gao L, Zhou YN, Jian X, Xiong CY, Wang ZJ, Brower DL, Ding WX. High resolution polarimeter-interferometer system for fast equilibrium dynamics and MHD instability studies on Joint-TEXT tokamak (invited). Rev Sci Instrum 2014; 85:11D303. [PMID: 25430163 DOI: 10.1063/1.4891603] [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] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A high-performance Faraday-effect polarimeter-interferometer system has been developed for the J-TEXT tokamak. This system has time response up to 1 μs, phase resolution < 0.1° and minimum spatial resolution ∼15 mm. High resolution permits investigation of fast equilibrium dynamics as well as magnetic and density perturbations associated with intrinsic Magneto-Hydro-Dynamic (MHD) instabilities and external coil-induced Resonant Magnetic Perturbations (RMP). The 3-wave technique, in which the line-integrated Faraday angle and electron density are measured simultaneously by three laser beams with specific polarizations and frequency offsets, is used. In order to achieve optimum resolution, three frequency-stabilized HCOOH lasers (694 GHz, >35 mW per cavity) and sensitive Planar Schottky Diode mixers are used, providing stable intermediate-frequency signals (0.5-3 MHz) with S/N > 50. The collinear R- and L-wave probe beams, which propagate through the plasma poloidal cross section (a = 0.25-0.27 m) vertically, are expanded using parabolic mirrors to cover the entire plasma column. Sources of systematic errors, e.g., stemming from mechanical vibration, beam non-collinearity, and beam polarization distortion are individually examined and minimized to ensure measurement accuracy. Simultaneous density and Faraday measurements have been successfully achieved for 14 chords. Based on measurements, temporal evolution of safety factor profile, current density profile, and electron density profile are resolved. Core magnetic and density perturbations associated with MHD tearing instabilities are clearly detected. Effects of non-axisymmetric 3D RMP in ohmically heated plasmas are directly observed by polarimetry for the first time.
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Affiliation(s)
- J Chen
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - G Zhuang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Q Li
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - L Gao
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y N Zhou
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - X Jian
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - C Y Xiong
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Z J Wang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - D L Brower
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W X Ding
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
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18
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Chen J, Zhuang G, Jian X, Li Q, Liu Y, Gao L, Wang ZJ. Equilibrium reconstruction based on core magnetic measurement and its applications on equilibrium transition in Joint-TEXT tokamak. Rev Sci Instrum 2014; 85:103501. [PMID: 25362387 DOI: 10.1063/1.4896476] [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: 06/04/2023]
Abstract
Evaluation and reconstruction of plasma equilibrium, especially to resolve the safety factor profile, is imperative for advanced tokamak operation and physics study. Based on core magnetic measurement by the high resolution laser polarimeter-interferometer system (POLARIS), the equilibrium of Joint-TEXT (J-TEXT) plasma is reconstructed and profiles of safety factor, current density, and electron density are, therefore, obtained with high accuracy and temporal resolution. The equilibrium reconstruction procedure determines the equilibrium flux surfaces essentially from the data of POLARIS. Refraction of laser probe beam, a major error source of the reconstruction, has been considered and corrected, which leads to improvement of accuracy more than 10%. The error of reconstruction has been systematically assessed with consideration of realistic diagnostic performance and scrape-off layer region of plasma, and its accuracy has been verified. Fast equilibrium transitions both within a single sawtooth cycle and during the penetration of resonant magnetic perturbation have been investigated.
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Affiliation(s)
- J Chen
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - G Zhuang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - X Jian
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Q Li
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - L Gao
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Z J Wang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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19
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Ji Y, Kangyu C, Jian X, Xizhen F, Xianlin S, Chunsheng A. CRT response score predicts the effects of cardiac resynchronisation therapy. Heart 2011. [DOI: 10.1136/heartjnl-2011-300867.647] [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: 11/04/2022]
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20
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Jian X, Xianlin S, Hao S, Ming C, Hongjun Z, Chunsheng A, Fuyuan L, Xizheng F, Ji Y. Ablation of left posterior fascicular tachycardia during sinus rhythm under the guide of non-contact array. Heart 2011. [DOI: 10.1136/heartjnl-2011-300867.542] [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: 11/04/2022]
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21
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Liu Y, Xu S, Li H, Jian X, Xu W. Localized and propagating surface plasmon co-enhanced Raman spectroscopy based on evanescent field excitation. Chem Commun (Camb) 2011; 47:3784-6. [DOI: 10.1039/c0cc04988c] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Abstract
In this paper, real-time extinction spectroscopy was employed to analyze in situ the fast formation process of silver seeds. The influencing factors for silver-seed formation, including the concentration of the reducer (NaBH(4)), the amount of stabilizer (citrate), and the addition procedure of NaBH(4), were evaluated. The configuration of the surface plasmon resonance (SPR) spectra of silver nanoparticles, which reflected the morphology of the produced silver seeds, was found to be distinctly affected by the NaBH(4) concentration. Homogeneous silver nanoparticles were obtained when the added NaBH(4) was lower in concentration than 2.00 mM. In contrast, higher concentrations of reducing agent (≥3.00 mM NaBH(4)) resulted in uneven silver nanoparticles. Mie theory was applied to clarify the correlation of the SPR and the size of the silver seeds. Repeated additions of a small amount of the reducing agent could increase the monodispersity and isotropy of silver seeds. Real-time extinction spectroscopy is a convenient technique that achieves the in-situ and nondestructive measurement of intermediates in the formation process of silver nanoseeds.
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Affiliation(s)
- Bin Tang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, PR. China
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23
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Zhou S, Guo F, Li L, Zhou Y, Lei Y, Hu Y, Su H, Chen X, Yin P, Jian X. Multiple logistic regression analysis of risk factors for carcinogenesis of oral submucous fibrosis in mainland China. Int J Oral Maxillofac Surg 2008; 37:1094-8. [PMID: 18684592 DOI: 10.1016/j.ijom.2008.06.010] [Citation(s) in RCA: 9] [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: 09/05/2007] [Revised: 01/09/2008] [Accepted: 06/20/2008] [Indexed: 11/19/2022]
Abstract
Oral submucous fibrosis (OSF), a chronic progressive disorder, is regarded as the premalignant lesion of oral squamous cell carcinoma (OSCC). Its distribution is associated with chewing betel quid (BQ). The objective of the present study was to investigate risk factors for the carcinogenesis of OSF in mainland China. A case-control study was performed in 42 patients with OSCC that originated from OSF and 40 OSF controls. Epidemiological data and information related to risk factors were collected using a short structured questionnaire. Odd ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analysis. In multivariate analysis, only age, duration of BQ chewing, duration of cigarette smoking, and OSF accompanied by oral leukoplakia or oral lichen planus were associated with significantly increased risk for the malignant transformation of OSF. These findings contribute to current knowledge on the prevention of carcinogenesis of OSF in mainland China.
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Affiliation(s)
- S Zhou
- Department of Oral and Maxillofacial Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, P.R.China
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Jian X, Morita N, Shi Q, Nakamura O, Liu D. FDTD Simulation of Nonlinear Ultrasonic Pulse Propagation in ESWL. Conf Proc IEEE Eng Med Biol Soc 2007; 2005:1806-9. [PMID: 17282568 DOI: 10.1109/iembs.2005.1616799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The extracorporeal shock wave lithotripsy (ESWL) has come into wide use due to its non-invasive advantage. However, as for the shock wave propagation in human body in relation to practical lithotripsy, there are a few studies on numerical simulation based on models conforming to practical situations. In this paper we report a numerical method of finite difference time domain (FDTD) for analyzing ultrasonic pulse nonlinear propagation in human body tissues and demonstrated it through an experiment of Reichenberger's ESWL in water.
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Affiliation(s)
- X Jian
- Dept. of Biomed. Eng., Tianjin Med. Univ
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25
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Abstract
This paper investigates Rayleigh wave interaction with machined slots on flat aluminium blocks to simulate surface breaking cracks. Using a finite element method, Rayleigh wave scattering by narrow slots of varied depth ranging from 0.5 mm to 20 mm is calculated. Pulsed wideband Rayleigh waves with a centre frequency of 590 kHz and -6 dB bandwidth of 520 kHz is considered. Reflection and transmission coefficients are calculated and compare well with the published literature. We and other workers have reported enhancement of the measured amplitude or particle velocity of an apparent Rayleigh wave close to a surface defect. In this paper, it is found that the predicted enhancement of in-plane components of particle velocities close to a crack is significantly higher than that of the out-of-plane components of particle velocities which appears to be mainly due to the mode-converted surface skimming longitudinal wave from the crack that has mainly in-plane components near the sample surface. The enhancement of the in-plane particle velocity will be observed regardless of the type of in-plane sensitive ultrasonic detector used. The explanation of the discrepancy of the reflection and transmission coefficients obtained by pulsed and narrow band or pseudo continuous Rayleigh waves is discussed. The later-arriving Rayleigh waves from reverberation along the inside of the crack surface are observed, as has been previously reported by other workers, and this may also be used to gauge slot depth.
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Affiliation(s)
- X Jian
- University of Warwick, Department of Physics, Ultrasonic Group, Coventry CV4 7AL, UK.
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Edwards RS, Dixon S, Jian X. Depth gauging of defects using low frequency wideband Rayleigh waves. Ultrasonics 2006; 44:93-8. [PMID: 16246389 DOI: 10.1016/j.ultras.2005.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/10/2005] [Accepted: 08/13/2005] [Indexed: 05/05/2023]
Abstract
In non-destructive testing for cracks it is not sufficient to simply detect the presence of a defect, but it is essential to have an accurate measure of the depth. Accurate calibration of the techniques used to gauge defect size is therefore necessary. Recent progress in the field of non-contact ultrasonic testing has led to the development of a practically viable system for generating and detecting wideband Rayleigh waves on electrically conducting or magnetic samples using electro-magnetic acoustic transducers (EMATs). This system has been used to gauge the depth and position of surface breaking defects, and has many applications including metal billet testing and detecting and sizing gauge corner cracking in rails. In this paper we report experiments calibrating the response of EMATs when a defect is present between the generator and receiver, using a calibration sample with slots machined perpendicular to the surface to simulate surface breaking cracks. The depth of the defect can be gauged in the time domain and frequency domain, with an accurate 'fingerprint' of the position given by an enhancement of the signal when the receiver is close to the defect. The best choice of EMAT design for different applications is discussed, as is the best position for the receive EMAT to avoid areas of interference between the Rayleigh wave and bulk waves diffracted from the crack tip.
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Affiliation(s)
- R S Edwards
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK.
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27
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Jian X, Clark WA, Kowalak J, Markey SP, Simonds WF, Northup JK. Gbetagamma affinity for bovine rhodopsin is determined by the carboxyl-terminal sequences of the gamma subunit. J Biol Chem 2001; 276:48518-25. [PMID: 11602594 DOI: 10.1074/jbc.m107129200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [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: 11/06/2022] Open
Abstract
Two native betagamma dimers, beta(1)gamma(1) and beta(1)gamma(2), display very different affinities for receptors. Since these gamma subunits differ in both primary structure and isoprenoid modification, we examined the relative contributions of each to Gbetagamma interaction with receptors. We constructed baculoviruses encoding gamma(1) and gamma(2) subunits with altered CAAX (where A is an aliphatic amino acid) motifs to direct alternate or no prenylation of the gamma chains and a set of gamma(1) and gamma(2) chimeras with the gamma(2) CAAX motif at the carboxyl terminus. All the gamma constructs coexpressed with beta(1) in Sf9 cells yielded beta(1)gamma dimers, which were purified to near homogeneity, and their affinities for receptors and Galpha were quantitatively determined. Whereas alteration of the isoprenoid of gamma(1) from farnesyl to geranylgeranyl and of gamma(2) from geranylgeranyl to farnesyl had no impact on the affinities of beta(1)gamma dimers for Galpha(t), the non-prenylated beta(1)gamma(2) dimer had significantly diminished affinity. Altered prenylation resulted in a <2-fold decrease in affinity of the beta(1)gamma(2) dimer for rhodopsin and a <3-fold change for the beta(1)gamma(1) dimer. In each case with identical isoprenylation, the beta(1)gamma(2) dimer displayed significantly greater affinity for rhodopsin compared with the beta(1)gamma(1) dimer. Furthermore, dimers containing chimeric Ggamma chains with identical geranylgeranyl modification displayed rhodopsin affinities largely determined by the carboxyl-terminal one-third of the protein. These results indicate that isoprenoid modification of the Ggamma subunit is essential for binding to both Galpha and receptors. The isoprenoid type influences the binding affinity for receptors, but not for Galpha. Finally, the primary structure of the Ggamma subunit provides a major contribution to receptor binding of Gbetagamma, with the carboxyl-terminal sequence conferring receptor selectivity.
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Affiliation(s)
- X Jian
- Laboratory of Cellular Biology, NIDCD, National Institutes of Health, Bethesda, Maryland 20892, USA
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Clark WA, Jian X, Chen L, Northup JK. Independent and synergistic interaction of retinal G-protein subunits with bovine rhodopsin measured by surface plasmon resonance. Biochem J 2001; 358:389-97. [PMID: 11513737 PMCID: PMC1222071 DOI: 10.1042/0264-6021:3580389] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have used surface plasmon resonance (SPR) measurements for the kinetic analysis of G-protein-receptor interaction monitored in real time. Functionally active rhodopsin was immobilized on an SPR surface, with full retention of biochemical specific activity for catalysis of nucleotide exchange on the retinal G-protein alpha subunit, via binding to immobilized concanavalin A. The binding interactions of bovine retinal alpha(t) and beta(1)gamma(1) subunits with rhodopsin measured by SPR were profoundly synergistic. Synergistic binding of the retinal G-protein subunits to rhodopsin was not observed for guanosine 5'-[gamma-thio]triphosphate-bound Galpha(t), nor was binding observed with squid retinal Galpha(q), which is not activated by bovine rhodopsin. The binding affinity (336+/-171 nM; mean value+/-S.D.) of retinal betagamma for rhodopsin in the presence of retinal alpha subunit measured by SPR confirmed the apparent affinity of 254 nM determined previously by nucleotide exchange assays. Binding of beta(1)gamma(1), beta(1)gamma(2), and beta(1)gamma(8-olf) dimers to rhodopsin, independently of the alpha subunit, was readily observable by SPR. Further, these dimers, differing only in their gamma subunit compositions, displayed markedly distinct binding affinities and kinetics. The beta(1)gamma(2) dimer bound with a kinetically determined K(d) of 13+/-3 nM, a value nearly identical with the biochemically determined K(1/2) of 10 nM. The physiologically appropriate beta(1)gamma(1) displayed rapid association and dissociation kinetics, whereas the other beta(1)gamma dimers dissociated at a rate less than 1/100 as fast. Thus rhodopsin interaction with its native signalling partners is both rapid and transient, whereas the interaction of rhodopsin with heterologous Gbetagamma dimers is markedly prolonged. These results suggest that the duration of a G-protein-coupled receptor signalling event is an intrinsic property of the G-protein coupling partners; in particular, the betagamma dimer.
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Affiliation(s)
- W A Clark
- Laboratory of Cellular Biology, National Institute on Deafness and Other Communication Disorders, Room 2A-11, 5 Research Court, Rockville, MD 20850, USA
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Lin Y, Jian X, Lin Z, Kroog GS, Mantey S, Jensen RT, Battey J, Northup J. Two amino acids in the sixth transmembrane segment of the mouse gastrin-releasing peptide receptor are important for receptor activation. J Pharmacol Exp Ther 2000; 294:1053-62. [PMID: 10945859] [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: 02/17/2023] Open
Abstract
The gastrin-releasing peptide receptor (GRP-R) is a G protein-coupled receptor that mediates a variety of cellular responses, including cell growth and modulation of neuronal activity by activation of heterotrimeric GTP-binding proteins in the Gq family. To understand the regulation of GRP-R signaling we have substituted alanine for each of 10 amino acid residues within the transmembrane (TM) helices of the GRP-R predicted to project into the binding pocket of the receptor and analyzed the importance of each of these residues for receptor function. Two mutations showed selective loss of either agonist (Y285A) or antagonist (F313A) affinity for the GRP-R. In addition, we identified two amino acid residues, Phe(270) and Asn(281), in the sixth TM segment, which are important for receptor-G protein interaction. In a competition-binding assay with an antagonist radioligand, bombesin showed a 20- to 100-fold decreased affinity for the N281A and F270A mutant GRP-R compared with wild-type GRP-R. The saturation-binding isotherms are best fit by a two-state model, indicating that the receptors are in either a low-affinity (K(D2)) or a high-affinity (K(D1)) state. The ratio of the two affinities (K(D2)/K(D1)) was significantly increased for both mutants compared with wild-type GRP-R, whereas the fraction of mutant receptors in the high-affinity state (R(1)) was decreased. GDP/guanosine-5'-O-(3-thio)triphosphate exchange catalyzed by the N281A mutant was lower than that observed for the wild-type GRP-R. However, for both mutants, bombesin was still able to stimulate 1,4,5-inositol triphosphate in transfected cells albeit with reduced activity. We conclude that these two TM residues are important for receptor-G protein coupling, and postulate that each mutation may affect GRP-R conformational change to the high-affinity, G protein-coupled state.
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Affiliation(s)
- Y Lin
- Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, MD 20892-2320, USA
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Abstract
Previous work on the desensitization of G protein-coupled receptors has focused on the role of arrestin binding following receptor phosphorylation. We have examined the hypothesis that phosphorylation alone contributes to desensitization. In this study we demonstrate that for the G(q)-coupled gastrin-releasing peptide receptor (GRP-R), phosphorylation by GRK2 to a stoichiometry of approximately 1 mol PO(4)/mol GRP-R is sufficient in the absence of arrestin to reduce the rate of receptor catalyzed G protein activation by approximately 80%. Furthermore, GRP-Rs exposed in vivo to agonist are rapidly phosphorylated to a similar stoichiometry and are desensitized to a similar degree. Finally, the molecular mechanism for both in vitro GRK2-induced and in vivo agonist-induced desensitization is primarily a decrease in the maximum velocity (V(max)) for the catalysis of guanine nucleotide exchange by the GRP-R rather than a change in the affinity of the receptor for the alpha(q) or betagamma subunits. Based on these results, we suggest that, for some G protein-coupled receptors, phosphorylation has a role in desensitization that is independent of arrestin.
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Affiliation(s)
- G S Kroog
- Laboratory of Molecular Biology, NIDCD, National Institutes of Health, Rockville, Maryland 20850-3227, USA
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Zhang WG, Liu XF, Wang Y, Jian X, Lin Q, Chen A, Wu CW, Huang HM, Li ZH, Zhang Y, Huang HL. [Construction of expressing vector for phage display scFv and a mouse unspecified antibody library]. Yi Chuan Xue Bao 1999; 26:99-106. [PMID: 10375858] [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: 02/12/2023]
Abstract
The display of antibody gene library on the surface of E. coli filamentous phage offers a new method of obtaining antibodies against specific antigens. In the paper, it is reported that a phagemid for phage display antibody, named after pFUW80, characterized expressing scFv either secretly or stickily. With a series of designed PCR primers, heavy-chain and light-chain variable region genes of mice antibodies were amplified and a mouse unspecified single-chain antibody library with the size of 1.2 x 10(6) clones was constructed. From this library, phage was selected out against antigen human IgG and detected by ELISA and partial sequence analysis. These primary results established the foundation for future research using this system.
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Affiliation(s)
- W G Zhang
- Institute of Genetics, Chinese Academy of Sciences, Beijing
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Abstract
We used an in situ reconstitution assay to examine the receptor coupling to purified G protein alpha subunits by the bombesin receptor family, including gastrin-releasing peptide receptor (GRP-R), neuromedin B receptor (NMB-R), and bombesin receptor subtype 3 (BRS-3). Cells expressing GRP-R or NMB-R catalyzed the activation of squid retinal Galphaq and mouse Galphaq but not bovine retinal Galphat or bovine brain Galphai/o. The GRP-R- and NMB-R-catalyzed activations of Galphaq were dependent upon and enhanced by different betagamma dimers in the same rank order as follows: bovine brain betagamma > beta1gamma2 >> beta1gamma1. Despite these qualitative similarities, GRP-R and NMB-R had distinct kinetic properties in receptor-G protein coupling. GRP-R had higher affinities for bovine brain betagamma, beta1gamma1, and beta1gamma2 and squid retinal Galphaq. In addition, GRP-R showed higher catalytic activity on squid Galphaq. Like GRP-R and NMB-R, BRS-3 did not catalyze GTPgammaS binding to Galphai/o or Galphat. However, BRS-3 showed little, if any, coupling with squid Galphaq but clearly activated mouse Galphaq. GRP-R and NMB-R catalyzed GTPgammaS binding to both squid and mouse Galphaq, with GRP-R activating squid Galphaq more effectively, and NMB-R also showed slight preference for squid Galphaq. These studies reveal that the structurally similar bombesin receptor subtypes, in particular BRS-3, possess distinct coupling preferences among members of the Galphaq family.
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Affiliation(s)
- X Jian
- Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, Rockville, Maryland 20850, USA
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Jian X, Sun B, Liu Y. [Clinic analysis of surgical treatment for benign parotid tumour 55 cases]. Lin Chuang Er Bi Yan Hou Ke Za Zhi 1999; 13:104-5. [PMID: 12563963] [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: 02/28/2023]
Abstract
OBJECTIVE To investigate the relationship between 3 kinds of surgical methods and the postoperative recurrence and complication of patients with the benign parotid tumours. METHOD The records of benign parotid tumours cases (55 patients), who were treated in 1987-1997 at our hospital, were retrospectively analysed. The operative methods as follows: local excision (20 patients), superficial parotidectomy (28 patients), total parotidectomy (7 patients), facial nerve was anatomied during operation for 35 patients. RESULT The rate of tumour recurrence, partial facial nerve paralysis, parotid gland fistula and Frey's syndroms after operation were 14.6% (8/55), 14.6% (8/55), 7.3% (4/55) and 7.3% (4/55) respectively. CONCLUSION The operation of superficial parotidectomy or total parotidectomy should be perfromed for benign parotid tumour cases, facial nerve should be anatomied during operation, for reducing tumour recurrence and facial nerve paralysis.
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Affiliation(s)
- X Jian
- Department of ENT, Second Affiliated Hospital, Hubei Medical University, Wuhan 430071
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Jian X, Wang C, Wang S. [Morphologic characteristics of dental cuticle on teeth affected by diabetic periodontitis]. Hua Xi Kou Qiang Yi Xue Za Zhi 1999; 17:56-7. [PMID: 12539324] [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: 02/28/2023]
Abstract
OBJECTIVE To determine the nature of the dental cuticle found on teeth with diabetic periodontitis. METHODS Thirteen permanent teeth which were extracted from three diabetic patients with periodontitis were studied, with the control group of 16 healthy teeth extracted for orthodontical reasons, then all the teeth were decalcified with 5% nitric acid, stained with HE, and examinated by using light microscope. RESULTS A layer of thick coat, dental cuticle, covered the root surface of the teeth with diabetic periodontitis, and the cuticle which presented regular laminar structure extended from the cementoenamel junction to the apical portion with different thickness from 40 to 80 microns, but no such similar cuticle structure was found on the healthy teeth of the control group. CONCLUSION There is abnormal cuticle structure on the teeth of diabetic patients with periodontitis.
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Affiliation(s)
- X Jian
- Department of Oral Biology, Faculty of Stomatology, Hunan Medical University
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Tang Z, Sheng Z, Liu S, Jian X, Sun K, Yan M. [The preventing function of garlic on experimental oral precancer and its effect on natural killer cells, T-lymphocytes and interleukin-2]. Hunan Yi Ke Da Xue Xue Bao 1998; 22:246-8. [PMID: 9868126] [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: 02/09/2023]
Abstract
In order to study the effect and mechanism of garlic on preventing oral precancer, we divided randomly 32 Wistar rats into two groups. The garlic group was painted with garlic solution on the hard palatal mucosae. The control group was applied with distilled water that is equal in quantity. Then, chemical carinogen 4-nitroquinoline 1-oxide (4NQO) was painted on the same sites for both groups, three times weekly. Eight rats were randomly killed in the 10th, 13th week. The hard palatal mucosae were examined with light microscope. Meanwhile, lymphocytes were isolated from the rat spleens. The activation of natural killer (NK) cells and T-lymphocytes, and level of interleukin-2 were determined by radioimmunoassay. The results revealed that garlic effectively prevented oral precancer induced by 4NQO. This effect may be related to the following factors that garlic can improve the activation of NK cells, the function of T-lymphocytes, and the level of IL-2.
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Affiliation(s)
- Z Tang
- Faculty of Stomatology, Hunan Medical University, Changsha
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Deng F, Tang Z, Liu B, Wang C, Jian X. [A study of anaerobic infection in maxillofacial region]. Hunan Yi Ke Da Xue Xue Bao 1998; 22:229-32. [PMID: 9868121] [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: 02/09/2023]
Abstract
To analyse the anaerobic infection of maxillofacial surgery and estimate the efficacy of antianaerobic therapy, 45 patients were divided into two groups, tinidazole group and metronidazole group. Bacterial culture was positive before treating in all cases. There were Bacillus Melaniogenicus, Veillonella, Peptococcus and Peptostreptococus, etc. There was excellent efficacy in the treatment of maxillofacial anaerobic infection by tinidazole intravenously. After treatment, the result of bacterial examination was negative. The healing rate was 96.4% in 28 cases which used tinidazol, but 82.4% in control group which used metronidazole. The value of white blood cell and the function of liver and kidney pro- and post-treatment were not significantly different (P < 0.05) by comparision.
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Affiliation(s)
- F Deng
- Department of Oral and Maxillorfacial Surgery, Xiangya Hospital, Hunan Medical University, Changsha
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Junjie M, Jian X, Lixin Y, Xiwen B. Urological complications and effects of double-J catheter in ureterovesical anastomosis after cadaveric kidney transplantation. Transplant Proc 1998; 30:3013-4. [PMID: 9838327 DOI: 10.1016/s0041-1345(98)00909-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- M Junjie
- Department of Kidney Transplantation, NanFang Hospital, Tong He, Guang Zhou, China
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Xie M, von Bohlen A, Klockenkämper R, Jian X, Günther K. Multielement analysis of Chinese tea ( Camellia sinensis ) by total-reflection X-ray fluorescence. ACTA ACUST UNITED AC 1998. [DOI: 10.1007/s002170050291] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Jian X. Increasing pressure: impacts of migration on cities. China Popul Today 1996; 13:21-2. [PMID: 12320646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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Abstract
Myosin light-chain kinase (MLCK) regulates actin-myosin II interactions in nonskeletal muscle cells, and the use of specific pharmacological inhibitors has implicated MLCK in retinal growth cone motility and neurite outgrowth. To further establish the existence and functions of MLCK in neurons, we isolated cDNAs encoding two forms of goldfish MLCK that were differentially expressed in the brain and gut and we sequenced the form most abundantly expressed in the brain (GFMLCK1). In situ hybridization with a cRNA probe specific to GFMLCK1 revealed widespread expression in CNS neurons, including tectal periventricular neurons and cerebellar and medullary neurons. After optic nerve crush, expression was markedly increased in the retinal ganglion cells. Expression peaked during the phase of axonal outgrowth, which, when taken together with our previous pharmacological studies, further supports a role for MLCK in growth cone motility.
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Affiliation(s)
- X Jian
- Department of Biological Sciences, University at Albany, SUNY 12222, USA
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Jian X, Chen X, Wang C. [Surgical treatment of unilateral alveolar cleft]. Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi 1996; 12:288-9. [PMID: 9387474] [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: 02/05/2023]
Abstract
In this study, 16 cases of unilateral alveolar cleft with cleft lip and palate were repaired with autografts of cancellous bone (13 cases) or hydroxyapatite (3 cases). The grafts were covered by reflected mucoperiosteal flaps and a mucosal flap from the upper lip. Twelve of the thirteen cases were followed up for 1-5 years. Nine of whom using cancellous bone had bony continuity of the maxilla and 7 cases erupted permanent maxillary canines within the area of autografts. None of the 3 cases using hydroxyapatite erupted a canine tooth. The results showed that autograft was better than hydroxyapatite in terms of maxillary canine eruption.
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Affiliation(s)
- X Jian
- Department of Oral and Maxillofacial Surgery, Xiangya Hospital, Hunan Medical University, Changsha
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Gu S, Jian X. The dual function of and counter-measures for rural population migration. Chin J Popul Sci 1996; 8:59-68. [PMID: 12291454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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43
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Zalewski PD, Jian X, Soon LL, Breed WG, Seamark RF, Lincoln SF, Ward AD, Sun FZ. Changes in distribution of labile zinc in mouse spermatozoa during maturation in the epididymis assessed by the fluorophore Zinquin. Reprod Fertil Dev 1996; 8:1097-105. [PMID: 8916286 DOI: 10.1071/rd9961097] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [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: 02/03/2023] Open
Abstract
The Zn(II)-specific fluorophore Zinquin was used to determine the regional distribution of free or loosely-bound Zn(II) in mouse spermatozoa. Spermatozoa from the testes exhibited bright fluorescence over the entire head; those from the caput epididymides generally fluoresced more brightly in the post-acrosomal region; and spermatozoa from the caudae epididymides fluoresced less brightly, with foci of fluorescence over the sperm head which were lost after extraction with Triton X-100 and hence appeared to be membrane-associated. Treatment of cauda sperm with sodium dodecyl sulfate resulted in a bright uniform Zinquin fluorescence in the heads, similar to that observed in caput sperm, indicating that the two types of sperm have similar amounts of head Zn(II) but that the availability of Zn(II) for binding Zinquin is different. By contrast, the intensity of tail fluorescence was similar in spermatozoa from different regions of the male reproductive tract and was largely unaffected by Triton X-100 extraction, consistent with an intracellular location. Similar differences were observed between caput sperm and cauda sperm in the rat. It is concluded that visualization and measurement of free or loosely-bound Zn(II) in subcellular compartments of spermatozoa should facilitate investigation of the role of this metal in the development and function of spermatozoa and abnormalities that might accompany infertility and Zn(II) deficiency.
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Affiliation(s)
- P D Zalewski
- Department of Medicine, University of Adelaide, Queen Elizabeth Hospital, Woodville, SA, Australia
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Abstract
Since cytoplasmic Ca2+ levels are reported to regulate neurite elongation, we tested whether calcium-activated kinases might be necessary for growth cone motility and neurite elongation in explant cultures of goldfish retina. Kinase inhibitors and activators were locally applied by micropipette to retinal growth cones and the responses were observed via phase-contrast videomicroscopy. In some cases, growth rates were also quantified over several hours after general application in the medium. The selective inhibitors of protein kinase C, calphostin C (0.1-1 microM) and chelerythrin (up to 50 microM), caused no obvious changes in growth cones or neurite elongation, and activators of PKC (phorbols, arachidonic acid, and diacylglycerol) also were generally without effects, although phorbols slowed the growth rate. Inhibitors of protein kinase A and tyrosine kinases also produced no obvious effects. The calmodulin antagonists, calmidazolium (0.1 microM), trifluoperazine (100 microM), and CGS9343B (50 microM), however, caused a reversible growth cone arrest with loss of filopodia and lamellipodia. The growth cone became a club-shaped swelling which sometimes moved a short distance back the shaft, leaving evacuated filaments at points of strong filopodial attachments. A similar reversible growth cone arrest occurred with the general kinase inhibitors: H7 at 200 but not at 100 microM, and staurosporine at 100 but not 10 nM, suggesting possible involvement of a calmodulin-dependent kinase (camK) rather than PKC. The selective inhibitor of camKII, KN-62 (tested up to 50 microM), produced no effects, but the specific myosin light-chain kinase (MLCK) inhibitors ML-7 (3-5 microM) and ML-9 (5-10 microM) reversibly reproduced the effect, suggesting that MLCK rather than camKII is necessary for growth cone motility. The MLCK inhibitors' effects both on growth cone morphology and on F-actin filaments (rhodamine-phalloidin staining) were similar to those caused by cytochalasin D (5 microM), and are discussed in light of findings that inhibiting MLCK disrupts actin filaments in astrocytes and fibroblasts.
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Affiliation(s)
- X Jian
- Department of Biological Sciences, State University of New York at Albany 12222
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