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Ichikawa S, Payne NC, Xu W, Chang CF, Vallavoju N, Frome S, Flaxman HA, Mazitschek R, Woo CM. The cyclimids: Degron-inspired cereblon binders for targeted protein degradation. Cell Chem Biol 2024:S2451-9456(24)00039-4. [PMID: 38320555 DOI: 10.1016/j.chembiol.2024.01.003] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/02/2023] [Accepted: 01/11/2024] [Indexed: 02/08/2024]
Abstract
Cereblon (CRBN) is an E3 ligase substrate adapter widely exploited for targeted protein degradation (TPD) strategies. However, achieving efficient and selective target degradation is a preeminent challenge with ligands that engage CRBN. Here, we report that the cyclimids, ligands derived from the C-terminal cyclic imide degrons of CRBN, exhibit distinct modes of interaction with CRBN and offer a facile approach for developing potent and selective bifunctional degraders. Quantitative TR-FRET-based characterization of 60 cyclimid degraders in binary and ternary complexes across different substrates revealed that ternary complex binding affinities correlated strongly with cellular degradation efficiency. Our studies establish the unique properties of the cyclimids as versatile warheads in TPD and a systematic biochemical approach for quantifying ternary complex formation to predict their cellular degradation activity, which together will accelerate the development of ligands that engage CRBN.
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Affiliation(s)
- Saki Ichikawa
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - N Connor Payne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Center for Systems Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Wenqing Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Chia-Fu Chang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nandini Vallavoju
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Spencer Frome
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Hope A Flaxman
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Ralph Mazitschek
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Christina M Woo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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2
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Henry C, Kruell JA, Wilson RM, Chang CF, Woo CM, Koehler AN. A Versatile Isocyanate-Mediated Strategy for Appending Chemical Tags onto Drug-Like Small Molecules. Bioconjug Chem 2023; 34:2181-2186. [PMID: 38052453 PMCID: PMC10739574 DOI: 10.1021/acs.bioconjchem.3c00352] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 10/09/2023] [Accepted: 10/23/2023] [Indexed: 12/07/2023]
Abstract
Target identification studies are a major hurdle in probe and drug discovery pipelines due to the need to chemically modify small molecules of interest, which can be time intensive and have low throughput. Here, we describe a versatile and scalable method for attaching chemical moieties to a small molecule, isocyanate-mediated chemical tagging (IMCT). By preparation of a template resin with an isocyanate capture group and a cleavable linker, nucleophilic groups on small molecules can be modified with an enforced one-to-one stoichiometry. We demonstrate a small molecule substrate scope that includes primary and secondary amines, thiols, phenols, benzyl alcohols, and primary alcohols. Cheminformatic analyses predict that IMCT is reactive with more than 25% of lead-like compounds in publicly available databases. To demonstrate that the method can produce biologically active molecules, we generated FKBP12 photoaffinity labeling (PAL) compounds with a wide range of affinities and showed that purified and crude cleavage products can bind to and label FKBP12. This method could be used to rapidly modify small molecules for many applications, including the synthesis of PAL probes, fluorescence polarization probes, pull-down probes, and degraders.
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Affiliation(s)
- Catherine
C. Henry
- David
H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
- MIT
Center for Precision Cancer Medicine, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Jasmin A. Kruell
- David
H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
- MIT
Center for Precision Cancer Medicine, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Robert M. Wilson
- David
H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
- MIT
Center for Precision Cancer Medicine, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Chia-Fu Chang
- Chemistry
and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Christina M. Woo
- Chemistry
and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Angela N. Koehler
- David
H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
- MIT
Center for Precision Cancer Medicine, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02142, United States
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3
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Flaxman HA, Chrysovergi MA, Han H, Kabir F, Lister RT, Chang CF, Black KE, Lagares D, Woo CM. Sanglifehrin A mitigates multi-organ fibrosis in vivo by inducing secretion of the collagen chaperone cyclophilin B. bioRxiv 2023:2023.03.09.531890. [PMID: 36945535 PMCID: PMC10028952 DOI: 10.1101/2023.03.09.531890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Pathological deposition and crosslinking of collagen type I by activated myofibroblasts drives progressive tissue fibrosis. Therapies that inhibit collagen synthesis by myofibroblasts have clinical potential as anti-fibrotic agents. Lysine hydroxylation by the prolyl-3-hydroxylase complex, comprised of cartilage associated protein, prolyl 3-hydroxylase 1, and cyclophilin B, is essential for collagen type I crosslinking and formation of stable fibers. Here, we identify the collagen chaperone cyclophilin B as a major cellular target of the macrocyclic natural product sanglifehrin A (SfA) using photo-affinity labeling and chemical proteomics. Our studies reveal a unique mechanism of action in which SfA binding to cyclophilin B in the endoplasmic reticulum (ER) induces the secretion of cyclophilin B to the extracellular space, preventing TGF-β1-activated myofibroblasts from synthesizing collagen type I in vitro without inhibiting collagen type I mRNA transcription or inducing ER stress. In addition, SfA prevents collagen type I secretion without affecting myofibroblast contractility or TGF-β1 signaling. In vivo, we provide chemical, molecular, functional, and translational evidence that SfA mitigates the development of lung and skin fibrosis in mouse models by inducing cyclophilin B secretion, thereby inhibiting collagen synthesis from fibrotic fibroblasts in vivo . Consistent with these findings in preclinical models, SfA reduces collagen type I secretion from fibrotic human lung fibroblasts and precision cut lung slices from patients with idiopathic pulmonary fibrosis, a fatal fibrotic lung disease with limited therapeutic options. Our results identify the primary liganded target of SfA in cells, the collagen chaperone cyclophilin B, as a new mechanistic target for the treatment of organ fibrosis.
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Trentadue K, Chang CF, Nalin A, Taylor RE. Enantioselective Total Synthesis of the Putative Biosynthetic Intermediate Ambruticin J. Chemistry 2021; 27:11126-11131. [PMID: 33887073 DOI: 10.1002/chem.202100975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Indexed: 11/09/2022]
Abstract
The family of anti-fungal natural products known as the ambruticins are structurally distinguished by a pair of pyran rings adorning a divinylcyclopropane core. Previous characterization of their biosynthesis, including the expression of a genetically modified producing organism, revealed that the polyketide synthase pathway proceeds via a diol intermediate, known as ambruticin J. Herein, we report the first enantioselective total synthesis of the putative PKS product, ambruticin J, according to a triply convergent synthetic route featuring a Suzuki-Miyaura cross-coupling and a Julia-Kocienski olefination for fragment assembly. This synthesis takes advantage of synthetic methodology previously developed by our laboratory for the stereoselective generation of the trisubstituted cyclopropyl linchpin.
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Affiliation(s)
- Kathryn Trentadue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Chia-Fu Chang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
| | - Ansel Nalin
- College of Medicine, The Ohio State University, 370 W. 9th Avenue, Columbus, OH, 43210, USA
| | - Richard E Taylor
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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5
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Chang CF, Flaxman HA, Woo CM. Enantioselective Synthesis and Biological Evaluation of Sanglifehrin A and B and Analogs. Angew Chem Int Ed Engl 2021; 60:17045-17052. [PMID: 34014025 DOI: 10.1002/anie.202103022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/03/2021] [Indexed: 01/02/2023]
Abstract
Sanglifehrin A and B are immunosuppressive macrocyclic natural products endowed with and differentiated by a unique spirocyclic lactam. Herein, we report an enantioselective total synthesis and biological evaluation of sanglifehrin A and B and analogs. Access to the spirocyclic lactam was achieved through convergent assembly of a key pyranone intermediate followed by a stereo-controlled spirocyclization. The 22-membered macrocyclic core was synthesized by ring-closing metathesis in the presence of 2,6-bis(trifluoromethyl) benzeneboronic acid (BFBB). The spirocyclic lactam and macrocycle fragments were united by a Stille coupling to furnish sanglifehrin A and B. Additional sanglifehrin B analogs with variation at the C40 position were additionally prepared. Biological evaluation revealed that the 2-CF3 analog of sanglifehrin B exhibited higher anti-proliferative activity than the natural products sanglifehrin A and B in Jurkat cells. Both natural products induced higher-order homodimerization of cyclophilin A (CypA), but only sanglifehrin A promoted CypA complexation with inosine-5'-monophosphate dehydrogenase 2 (IMPDH2). The synthesis reported herein will enable further evaluation of the spirolactam and its contribution to sanglifehrin-dependent immunosuppressive activity.
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Affiliation(s)
- Chia-Fu Chang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
| | - Hope A Flaxman
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
| | - Christina M Woo
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
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6
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Chang CF, Hsieh HH, Huang HC, Huang YL. The Effect of Positive Emotion and Interpersonal Relationships to Adaptation of School Life on High School Athletic Class Students. Int J Environ Res Public Health 2020; 17:ijerph17176354. [PMID: 32878329 PMCID: PMC7504183 DOI: 10.3390/ijerph17176354] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/29/2020] [Accepted: 08/30/2020] [Indexed: 11/16/2022]
Abstract
Background: Adaption for school life is important for all students. As for athletic students, since they need to cope with schoolwork and extensive training, adaption for school life could be very challenging. Taking this into consideration, the purpose of this study was to explore the factors which may help high school athletic students’ adaption of school life. Owing to this, the study explored previous researches and proposed four hypotheses: the first two hypotheses proposed that athletes’ positive emotion will have positive impacts on both their interpersonal relationships and adaption of school life; the third hypothesis suggests that athletes’ interpersonal relationships will have positive impacts on their adaption of school life and the fourth hypothesis suggested that interpersonal relationships play a mediating role among the positive emotion’s effect on adaption of school life. Methods: A total of 800 structured questionnaires were distributed to eleven high schools with athletic class students for data collection with a valid return rate of 90.6%. Structural equation modelling was used to test the relationship among them. Results: The result showed that positive emotion (β = 0.72, p < 0.05) and interpersonal relationships (β = 0.34, p < 0.05) had positive impacts on students’ adaption of school life with a predictive power of 68%. In addition, positive emotion also affected students’ school life adaption through interpersonal relationships. Conclusion: The study confirmed the positive emotion can have significant influences on student athletes’ interpersonal relationships and school life adaption. Implications: According to our findings, we suggest to encourage and promote athletes’ positive emotions so to help them have better interpersonal relationships and school life adaption.
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Affiliation(s)
- Chia-Fu Chang
- Physical Education and Arts School, Chengyi University College, Jimei University, Xiamen 361023, China;
| | - Huey-Hong Hsieh
- Department of Leisure Management, Taiwan Shoufu University, Tainan 72153, Taiwan;
| | - Hsiu-Chin Huang
- Physical Education and Arts School, Chengyi University College, Jimei University, Xiamen 361023, China;
- Correspondence: ; Tel.: +886-886-9-01195520
| | - Yu-Lan Huang
- Department of Physical Education, Health & Recreation, National Chiayi University, Chiayi 62103, Taiwan;
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7
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Flaxman HA, Chang CF, Wu HY, Nakamoto CH, Woo CM. A Binding Site Hotspot Map of the FKBP12-Rapamycin-FRB Ternary Complex by Photoaffinity Labeling and Mass Spectrometry-Based Proteomics. J Am Chem Soc 2019; 141:11759-11764. [PMID: 31309829 DOI: 10.1021/jacs.9b03764] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Structural characterization of small molecule binding site hotspots within the global proteome is uniquely enabled by photoaffinity labeling (PAL) coupled with chemical enrichment and unbiased analysis by mass spectrometry (MS). MS-based binding site maps provide structural resolution of interaction sites in conjunction with identification of target proteins. However, binding site hotspot mapping has been confined to relatively simple small molecules to date; extension to more complex compounds would enable the structural definition of new binding modes in the proteome. Here, we extend PAL and MS methods to derive a binding site hotspot map for the immunosuppressant rapamycin, a complex macrocyclic natural product that forms a ternary complex with the proteins FKBP12 and FRB. Photo-rapamycin was developed as a diazirine-based PAL probe for rapamycin, and the FKBP12-photo-rapamycin-FRB ternary complex formed readily in vitro. Photoirradiation, digestion, and MS analysis of the ternary complex revealed a McLafferty rearrangement product of photo-rapamycin conjugated to specific surfaces on FKBP12 and FRB. Molecular modeling based on the binding site map revealed two distinct conformations of complex-bound photo-rapamycin, providing a 5.0 Å distance constraint between the conjugated residues and the diazirine carbon and a 9.0 Å labeling radius for the diazirine upon photoactivation. These measurements may be broadly useful in the interpretation of binding site measurements from PAL. Thus, in characterizing the ternary complex of photo-rapamycin by MS, we applied binding site hotspot mapping to a macrocyclic natural product and extracted precise structural measurements for interpretation of PAL products that may enable the discovery of new binding sites in the "undruggable" proteome.
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Affiliation(s)
- Hope A Flaxman
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Chia-Fu Chang
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Hung-Yi Wu
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Carter H Nakamoto
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Christina M Woo
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
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8
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Liu XH, Chang CF, Tjeng LH, Komarek AC, Wirth S. Large magnetoresistance effects in Fe 3O 4. J Phys Condens Matter 2019; 31:225803. [PMID: 30836348 DOI: 10.1088/1361-648x/ab0cf4] [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] [Indexed: 06/09/2023]
Abstract
We investigated the magnetoresistance (MR) of a single crystal of magnetite, Fe3O4. In an effort to distinguish between different contributions to the MR the samples were prepared in two different initial magnetic states, i.e. by either zero-field or by field cooling from room temperature. The different magnetic structures in this sample have a dramatic effect on the magnetoresistance: for initially zero-field-cooled conditions a negative MR of about -20% is observed just below the Verwey transition at [Formula: see text] K. For decreasing temperature the MR increases, changes sign at ∼78 K and reaches a record positive value of ∼45% at around 50 K. This behavior is completely absent in the field-cooled sample. Magnetization measurements corroborate an alignment of the easy magnetization direction in applied magnetic fields below [Formula: see text] as a cause of the strong effects observed in both, magnetization and MR. Our results point to a complex interplay of structural and magnetocrystalline effects taking place upon cooling Fe3O4 through [Formula: see text].
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Affiliation(s)
- X H Liu
- Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany. State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People's Republic of China
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9
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Larsen EM, Chang CF, Sakata-Kato T, Arico JW, Lombardo VM, Wirth DF, Taylor RE. Conformation-guided analogue design identifies potential antimalarial compounds through inhibition of mitochondrial respiration. Org Biomol Chem 2018; 16:5403-5406. [PMID: 30009295 PMCID: PMC7487978 DOI: 10.1039/c8ob01257a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The synthesis of a 2-methyl-substituted analogue of the natural product, neopeltolide, is reported in an effort to analyze the importance of molecular conformation and ligand-target interactions in relation to biological activity. The methyl substitution was incorporated via highly diastereoselective ester enolate alkylation of a late-stage intermediate. Coupling of the oxazole sidechain provided 2-methyl-neopeltolide and synthetic neopeltolide via total synthesis. The substitution was shown to maintain the conformational preferences of its biologically active parent compound through computer modeling and NMR studies. Both compounds were shown to be potential antimalarial compounds through the inhibition of mitochondrial respiration in P. falciparum parasites.
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Affiliation(s)
- Erik M Larsen
- Department of Chemistry & Biochemistry and the Warren Family Research Center for Drug Discovery, University of Notre Dame, Notre Dame, IN 46556, USA.
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Lin TY, Chen YL, Chang CF, Huang GM, Huang CW, Hsieh CY, Lo YC, Lu KC, Wu WW, Chen LJ. In Situ Investigation of Defect-Free Copper Nanowire Growth. Nano Lett 2018; 18:778-784. [PMID: 29369633 DOI: 10.1021/acs.nanolett.7b03992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The fabrication and placement of high purity nanometals, such as one-dimensional copper (Cu) nanowires, for interconnection in integrated devices have been among the most important technological developments in recent years. Structural stability and oxidation prevention have been the key issues, and the defect control in Cu nanowire growth has been found to be important. Here, we report the synthesis of defect-free single-crystalline Cu nanowires by controlling the surface-assisted heterogeneous nucleation of Cu atomic layering on the graphite-like loop of an amorphous carbon (a-C) lacey film surface. Without a metal-catalyst or induced defects, the high quality Cu nanowires formed with high aspect ratio and high growth rate of 578 nm/s. The dynamic study of the growth of heterogeneous nanowires was conducted in situ with a high-resolution transmission electron microscope. The study illuminates the new mechanism by heterogeneous nucleation control and laying the groundwork for better understanding of heterosurface-assisted nucleation of defect-free Cu nanowire on a-C lacey film.
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Affiliation(s)
- Ting-Yi Lin
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Yong-Long Chen
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Chia-Fu Chang
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Guan-Min Huang
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Chun-Wei Huang
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Cheng-Yu Hsieh
- Material and Chemical Research Laboratories, Nanotechnology Research Center, Industrial Technology Research Institute , Hsinchu 310, Taiwan
| | - Yu-Chieh Lo
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Kuo-Chang Lu
- Department of Materials Science and Engineering, National Cheng Kung University , Tainan 701, Taiwan
| | - Wen-Wei Wu
- Department of Materials Science and Engineering, National Chiao Tung University , 1001 University Road, Hsinchu 300, Taiwan
| | - Lih-Juann Chen
- Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 300, Taiwan
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Chang CF, Chen JY, Huang CW, Chiu CH, Lin TY, Yeh PH, Wu WW. Direct Observation of Dual-Filament Switching Behaviors in Ta 2 O 5 -Based Memristors. Small 2017; 13:1603116. [PMID: 28165195 DOI: 10.1002/smll.201603116] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 12/19/2016] [Indexed: 06/06/2023]
Abstract
The Forming phenomenon is observed via in situ transmission electron microscopy in the Ag/Ta2 O5 /Pt system. The device is switched to a low-resistance state as the dual filament is connected to the electrodes. The results of energy dispersive spectrometer and electron energy loss spectroscopy analyses demonstrate that the filament is composed by a stack of oxygen vacancies and Ag metal.
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Affiliation(s)
- Chia-Fu Chang
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
| | - Jui-Yuan Chen
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
| | - Chun-Wei Huang
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
| | - Chung-Hua Chiu
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
| | - Ting-Yi Lin
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
| | - Ping-Hung Yeh
- Department of Physics, Tamkang University, 151 Ying Chuan Road, 251, Taipei, Taiwan
| | - Wen-Wei Wu
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, 30010, Hsinchu, Taiwan
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12
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Zhang L, Zhao CX, Ji HX, He J, Chang CF, Hao HY, Li JG. [Effect of occupational lead exposure on the blood pressure of lead-exposed workers]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2016; 34:825-827. [PMID: 28043269 DOI: 10.3760/cma.j.issn.1001-9391.2016.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the effect of occupational lead exposure on blood pressure and pro-vide supportive evidence of health protection on lead - exposed workers. Methods: 612 workers (452 lead - ex-posed workers, 160 workers as control) were recruited in the battery factory. The blood lead concentration and blood pressure were detected by occupational health examination and biological monitoring. The relationship of blood lead concentration and blood pressure wasanalyzed. Results: The blood lead concentration in the exposed group (249.84±137.74) μg/L was higher than that of the control group (117.25±70.15) μg/L, and the differ-ence was statistically significant (P<0.01) . The difference of abnormal blood pressure and diastolic pressure among the exposed and the control group was statistically significant (P<0.05) . The abnormal blood pressure rate, systolic pressure rate and diastolic pressure rate in the 400~726 μg/L group was higher than that of the 6~199 μg/L and 200~399 μg/L group, and the difference was statistically significant (P<0.01) . Multiple lin-ear regression analysis showed that the influencing factors of the systolic pressure followed by sex, age, length of service and blood lead concentration, diastolic pressure followed by sex, age, smoke and blood lead concen-tration. Conclusion: These findings suggest that long - term occupational lead exposure may result in the in-crease of blood lead concentration.
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Affiliation(s)
- L Zhang
- Department of Epidemiology and Statistics, Hebei Medical University, Shijiazhuang 050017, China
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13
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Chen YH, Huang CW, Yeh PH, Chen JY, Lin TY, Chang CF, Wu WW. A solid-state cation exchange reaction to form multiple metal oxide heterostructure nanowires. Nanoscale 2016; 8:17039-17043. [PMID: 27714036 DOI: 10.1039/c6nr01287f] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Metal oxide nanostructures have been investigated extensively due to their wide range of physical properties; zinc oxide is one of the most promising materials. It exhibits fascinating functional properties and various types of morphologies. In particular, ZnO heterostructures have attracted great attention because their performance can be modified and further improved by the addition of other materials. In this study, we successfully transformed ZnO nanowires (NWs) into multiple ZnO/Al2O3 heterostructure NWs via a solid-state cation exchange reaction. The experiment was carried out in situ via an ultrahigh vacuum transmission electron microscope (UHV-TEM), which was equipped with a video recorder. Moreover, we analyzed the structure and composition of the heterostructure NWs by Cs-corrected STEM equipped with EDS. Based on these experimental results, we inferred a cation exchange reaction ion path model. Additionally, we investigated the defects that appeared after the cation reaction, which resulted from the remaining zinc ions. These multiple heterostructure ZnO/Al2O3 NWs exhibited excellent UV sensing sensitivity and efficiency.
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Affiliation(s)
- Y H Chen
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
| | - C W Huang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
| | - P H Yeh
- Department of Physics, Tam Kang University, New Taipei 251, Taiwan
| | - J Y Chen
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
| | - T Y Lin
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
| | - C F Chang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
| | - W W Wu
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
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14
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Chang CF, Yang J, Li XF, Zhao WM, Chen SS, Wang GP, Xu CS. [SPINK3: A novel growth factor that promotes rat liver regeneration]. Mol Biol (Mosk) 2016; 50:457-65. [PMID: 27414783 DOI: 10.7868/s0026898416030058] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/13/2015] [Indexed: 11/23/2022]
Abstract
Serine peptidase inhibitor, Kazal type 3 (SPINK3) is a trypsin inhibitor, and also a growth factor that has an identical structure to epidermal growth factor (EGF), which could combine with epidermal growth factor receptor (EGFR) to promote cell proliferation. To shed light on the role and regulation mechanism of SPINK3 in rat liver regeneration (LR), Rat Genome 230 2.0 assay was used to detect the expression profiles of LR genes after partial hepatectomy (PH). The results showed that Spink3 was significantly up-regulated at 2-24 h and 72-168 h after PH. In the present study, RT-PCR and immunoblotting were used to validate the assay results. Ingenuity Pathway Analysis 9.0 (IPA) software was used to build the SPINK3 signaling regulating LR and analyze the possible mechanism. And then the expression of cell proliferation-associated gene Ccna2 was examined by RT-PCR in normal rat liver cell line BRL-3A in which Spink3 was overexpressed. The results showed that Ccna2 was significantly up-regulated in BRL-3A in which Spink3 was over-expressed. SPINK3 combining with EGFR accelerated cell proliferation during rat liver regeneration via P38, PKC, JAK-STAT and AKT pathways. Thus, SPINK3 was likely to promote hepatocytes proliferation in LR through P38, PKC, JAK-STAT and AKT.
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Affiliation(s)
- C F Chang
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - J Yang
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - X F Li
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - W M Zhao
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - S S Chen
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - G P Wang
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China
| | - C S Xu
- State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P.R. China.,College of Life Science, Henan Normal University, Xinxiang, 453007, P.R. China.,
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15
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Zhao WM, Qin YL, Niu ZP, Chang CF, Yang J, Li MH, Zhou Y, Xu CS. Branches of the NF-κB signaling pathway regulate proliferation of oval cells in rat liver regeneration. Genet Mol Res 2016; 15:gmr7750. [PMID: 27050988 DOI: 10.4238/gmr.15017750] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The NF-kB (nuclear factor kB) pathway is involved in the proliferation of many cell types. To explore the mechanism of the NF-kB signaling pathway underlying the oval cell proliferation during rat liver regeneration, the Rat Genome 230 2.0 Array was used to detect expression changes of NF-kB signaling pathway-related genes in oval cells. The results revealed that the expression levels of many genes in the NF-kB pathway were significantly changed. This included 48 known genes and 16 homologous genes, as well as 370 genes and 85 homologous genes related to cell proliferation. To further understand the biological significance of these changes, an expression profile function was used to analyze the potential biological processes. The results showed that the NF-kB pathway promoted oval cell proliferation mainly through three signaling branches; the tumor necrosis factor alpha branch (TNF-a pathway), the growth factor branch, and the chemokine branch. An integrated statistics method was used to define the key genes in the NF-kB pathway. Seven genes were identified to play vital roles in the NF-kB pathway. To confirm these results, the protein content, including two key genes (TNF and FGF11) and two non-key genes (CCL2 and TNFRSF12A), were analyzed using two-dimensional gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The results were generally consistent with those of the array data. To conclude, three branches and seven key genes were involved in the NF-kB signaling pathway that regulates oval cell proliferation during rat liver regeneration.
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Affiliation(s)
- W M Zhao
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - Y L Qin
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - Z P Niu
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - C F Chang
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - J Yang
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - M H Li
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
| | - Y Zhou
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China.,College of Computer and Information Engineering, Henan Normal University, Xinxiang, Henan, China
| | - C S Xu
- College of Life Science, Henan Normal University, Xinxiang, China.,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, China
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16
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Wu YT, Huang CW, Chiu CH, Chang CF, Chen JY, Lin TY, Huang YT, Lu KC, Yeh PH, Wu WW. Nickel/Platinum Dual Silicide Axial Nanowire Heterostructures with Excellent Photosensor Applications. Nano Lett 2016; 16:1086-91. [PMID: 26789624 DOI: 10.1021/acs.nanolett.5b04309] [Citation(s) in RCA: 3] [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] [Indexed: 05/07/2023]
Abstract
Transition metal silicide nanowires (NWs) have attracted increasing attention as they possess advantages of both silicon NWs and transition metals. Over the past years, there have been reported with efforts on one silicide in a single silicon NW. However, the research on multicomponent silicides in a single silicon NW is still rare, leading to limited functionalities. In this work, we successfully fabricated β-Pt2Si/Si/θ-Ni2Si, β-Pt2Si/θ-Ni2Si, and Pt, Ni, and Si ternary phase axial NW heterostructures through solid state reactions at 650 °C. Using in situ transmission electron microscope (in situ TEM), the growth mechanism of silicide NW heterostructures and the diffusion behaviors of transition metals were systematically studied. Spherical aberration corrected scanning transmission electron microscope (Cs-corrected STEM) equipped with energy dispersive spectroscopy (EDS) was used to analyze the phase structure and composition of silicide NW heterostructures. Moreover, electrical and photon sensing properties for the silicide nanowire heterostructures demonstrated promising applications in nano-optoeletronic devices. We found that Ni, Pt, and Si ternary phase nanowire heterostructures have an excellent infrared light sensing property which is absent in bulk Ni2Si or Pt2Si. The above results would benefit the further understanding of heterostructured nano materials.
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Affiliation(s)
- Yen-Ting Wu
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Chun-Wei Huang
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Chung-Hua Chiu
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Chia-Fu Chang
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Jui-Yuan Chen
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Ting-Yi Lin
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Yu-Ting Huang
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
| | - Kuo-Chang Lu
- Department of Materials Science and Engineering, National Cheng Kung University , No. 1, University Road, Tainan City 70101, Taiwan
| | - Ping-Hung Yeh
- Department of Physics, Tamkang University , No. 151, Yingzhuan Road, Tamsui District, New Taipei City 25137, Taiwan
| | - Wen-Wei Wu
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, East District, Hsinchu City 30010, Taiwan
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17
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Huang WH, Gao TL, Huang CW, Chang CF, Wu WW, Tuan HY. Synthesis of single-crystalline Ge 1Sb 2Te 4nanoplates in solution phase. CrystEngComm 2016. [DOI: 10.1039/c5ce02355f] [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: 11/21/2022]
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18
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Schock EN, Chang CF, Struve JN, Chang J, Brugmann SA. Using the talpid
2
as novel model for determining the cellular and molecular etiology of Oral-facial-digital syndrome. Cilia 2015. [PMCID: PMC4519141 DOI: 10.1186/2046-2530-4-s1-p41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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19
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Chang CF, Stefan E, Taylor RE. Total Synthesis and Structural Reassignment of Lyngbyaloside C Highlighted by Intermolecular Ketene Esterification. Chemistry 2015; 21:10681-6. [PMID: 26101039 PMCID: PMC6896800 DOI: 10.1002/chem.201502132] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Indexed: 11/07/2022]
Abstract
Lyngbyaloside C, a classic macrolide, isolated from Lyngbya bouilloni, has shown moderate anticancer activity against several cancer cell lines. Here, we report the first total synthesis and stereochemical configuration reassignment of lyngbyaloside C. The synthesis highlights a one-pot intermolecular ketene esterification reaction to form the crucial tertiary ester and tetrahydropyran. In addition, a novel and concise synthetic pathway towards the 1,3-syn secondary, tertiary diol fragment is described using a regio- and stereospecific electrophilic ether transfer reaction.
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Affiliation(s)
- Chia-Fu Chang
- Warren Family Research Center for Drug Discovery and Development and the Department of Chemistry & Biochemistry, 250 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556-5670 (USA)
| | - Eric Stefan
- Warren Family Research Center for Drug Discovery and Development and the Department of Chemistry & Biochemistry, 250 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556-5670 (USA)
| | - Richard E Taylor
- Warren Family Research Center for Drug Discovery and Development and the Department of Chemistry & Biochemistry, 250 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556-5670 (USA).
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20
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Chang CF, Zhao WM, Mei JX, Zhou Y, Pan CY, Xu TT, Xu CS. Branches of NF-κb signaling pathway regulate hepatocyte proliferation in rat liver regeneration. Genet Mol Res 2015. [PMID: 26214444 DOI: 10.4238/2015.july.13.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Previous studies have demonstrated that the nuclear factor κB (NF-κB) pathway is involved in promoting cell proliferation. To further explore the regulatory branches and their sequence in the NF-κB pathway in the promotion of hepatocyte proliferation at the transcriptional level during rat liver regeneration, Rat Genome 230 2.0 array was used to detect the expression changes of the isolated hepatocytes. We found that many genes involved in the NF-κB pathway (including 73 known genes and 19 homologous genes) and cell proliferation (including 484 genes and 104 homologous genes) were associated with liver regeneration. Expression profile function (Ep) was used to analyze the biological processes. It was revealed that the NF-κB pathway promoted hepatocyte proliferation through three branches. Several methods of integrated statistics were applied to extract and screen key genes in liver regeneration, and it indicated that eight genes may play a vital role in rat liver regeneration. To confirm the above predicted results, Ccnd1, Jun and Myc were analyzed using qRT-PCR, and the results were generally consistent with that of microarray data. It is concluded that 3 branches and 8 key genes involved in the NF-κB pathway regulate hepatocyte proliferation during rat liver regeneration.
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Affiliation(s)
- C F Chang
- College of Life Science, Henan Normal University, Xinxiang, China
| | - W M Zhao
- College of Life Science, Henan Normal University, Xinxiang, China
| | - J X Mei
- College of Life Science, Henan Normal University, Xinxiang, China
| | - Y Zhou
- College of Life Science, Henan Normal University, Xinxiang, China
| | - C Y Pan
- College of Life Science, Henan Normal University, Xinxiang, China
| | - T T Xu
- College of Life Science, Henan Normal University, Xinxiang, China
| | - C S Xu
- College of Life Science, Henan Normal University, Xinxiang, China
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21
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Chang CF, Yang J, Zhao WM, Li Y, Guo PJ, Li MH, Zhou Y, Xu CS. Gene expression profiling analysis of 5-hydroxytryptamine signaling pathway in rat regenerating liver and different types of liver cells. Genet Mol Res 2015; 14:3409-20. [PMID: 25966107 DOI: 10.4238/2015.april.15.4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We examined the gene expression profiles of the 5-hydroxytryptamine signaling pathway in the regenerating liver and 8 types of liver cells during rat liver regeneration, and explored expression differences in 5-hydroxytryptamine signaling pathway genes at the level of tissues and cells, as well as the role of the pathway on liver regeneration. Eight types of rat regenerating liver cells were isolated using Percoll density-gradient centrifugation and immunomagnetic bead methods. Rat Genome 230 2.0 Array was used to detect expression changes in 5-hydroxytryptamine signaling pathway genes. The results showed that 26, 47, 8, 21, 16, 19, 22, 27, and 20 genes changed significantly in hepatocytes, biliary epithelial cells, hepatic stellate cells, oval cells, sinusoidal endothelial cells, Kupffer cells, pit cells, dendritic cells, and the regenerating liver, respectively. Synthetic effects of 5-hydroxytryptamine signaling pathway genes in 8 types of liver cells showed that 26 genes were expressed significantly; the expression trends of 10 genes were the same in the regenerating liver, while others were different. Based on the gene expression profiles of the 8 types of liver cells, 5-hydroxytryptamine promoted hepatocyte proliferation through the RAS and STAT3 signaling pathways, proliferation and differentiation of sinusoidal endothelial cells through the STAT3 signaling pathway, and proliferation and apoptosis of pit cells through the AKT3 signaling pathway. There were large differences in genes involved in 5-hydroxytryptamine signaling at the tissue and cellular levels; thus, liver regeneration should be studied in-depth at the cellular level to reveal the molecular mechanism of liver regeneration.
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Affiliation(s)
- C F Chang
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - J Yang
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - W M Zhao
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - Y Li
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - P J Guo
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - M H Li
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - Y Zhou
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
| | - C S Xu
- Key Laboratory for Cell Differentiation Regulation, Xinxiang, Henan, China
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22
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Lee JJ, Chang CF, Sheu JR, Jayakumar T. Pharmacology and Clinical Effect of Platonin, a Cyanine Photosensitizing Dye: Potential Molecular Targets. Curr Pharm Biotechnol 2014; 15:700-11. [DOI: 10.2174/138920101508140930154046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 11/22/2022]
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23
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de Jong S, Kukreja R, Trabant C, Pontius N, Chang CF, Kachel T, Beye M, Sorgenfrei F, Back CH, Bräuer B, Schlotter WF, Turner JJ, Krupin O, Doehler M, Zhu D, Hossain MA, Scherz AO, Fausti D, Novelli F, Esposito M, Lee WS, Chuang YD, Lu DH, Moore RG, Yi M, Trigo M, Kirchmann P, Pathey L, Golden MS, Buchholz M, Metcalf P, Parmigiani F, Wurth W, Föhlisch A, Schüßler-Langeheine C, Dürr HA. Speed limit of the insulator-metal transition in magnetite. Nat Mater 2013; 12:882-6. [PMID: 23892787 DOI: 10.1038/nmat3718] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 06/24/2013] [Indexed: 05/19/2023]
Abstract
As the oldest known magnetic material, magnetite (Fe3O4) has fascinated mankind for millennia. As the first oxide in which a relationship between electrical conductivity and fluctuating/localized electronic order was shown, magnetite represents a model system for understanding correlated oxides in general. Nevertheless, the exact mechanism of the insulator-metal, or Verwey, transition has long remained inaccessible. Recently, three-Fe-site lattice distortions called trimerons were identified as the characteristic building blocks of the low-temperature insulating electronically ordered phase. Here we investigate the Verwey transition with pump-probe X-ray diffraction and optical reflectivity techniques, and show how trimerons become mobile across the insulator-metal transition. We find this to be a two-step process. After an initial 300 fs destruction of individual trimerons, phase separation occurs on a 1.5±0.2 ps timescale to yield residual insulating and metallic regions. This work establishes the speed limit for switching in future oxide electronics.
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Affiliation(s)
- S de Jong
- 1] Stanford Institute for Energy and Materials Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA [2]
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24
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Chang JY, Lin JM, Su LF, Chang CF. Improved performance of CuInS2 quantum dot-sensitized solar cells based on a multilayered architecture. ACS Appl Mater Interfaces 2013; 5:8740-8752. [PMID: 23937511 DOI: 10.1021/am402547e] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This article describes a CuInS2 quantum dot (QD)-sensitized solar cell (QDSSC) with a multilayered architecture and a cascaded energy-gap structure fabricated using a successive ionic-layer adsorption and reaction process. We initially used different metal chalcogenides as interfacial buffer layers to improve unmatched band alignments between the TiO2 and CuInS2 QD sensitizers. In this design, the photovoltaic performance, in terms of the short-circuit current density (JSC), open-circuit voltage (VOC), fill factor (FF), and power conversion efficiency (PCE), was significantly improved. Both JSC and VOC were improved in CuInS2-based QDSSCs in the presence of interfacial buffer layers because of proper band alignment across the heterointerface and the negative band edge movement of TiO2. The PCE of CuInS2-based QDSSCs containing In2Se3 interfacial buffer layers was 1.35%, with JSC=5.83 mA/cm2, VOC=595 mV, and FF=39.0%. We also examined the use of alternative CdS and CdSe hybrid-sensitized layers, which were sequentially deposited onto the In2Se3/CuInS2 configuration for creating favorable cascaded energy-gap structures. Both JSC (11.3 mA cm(-2)) and FF (47.3%) for the CuInS2/CdSe hybrid-sensitized cells were higher than those for CuInS2-based cells (JSC=5.83 mA cm(-2) and FF=39.0%). In addition, the hybrid-sensitized cells had PCEs that were 1.3 times those of cells containing identically pretreated In2Se3 interfacial buffer layers. Additionally, we determined that ZnSe served as a good passivation layer on the surface of CuInS2/CdSe hybrid-sensitized QDs, prevented current leakage from the QDs to electrolytes, and lowered interfacial charge recombination. Under simulated illumination (AM 1.5, 100 mW cm(-2)), multilayered QDSSCs with distinct architectures delivered a maximum external quantum efficiency of 80% at 500 nm and a maximum PCE of 4.55%, approximately 9 times that of QDSSCs fabricated with pristine CuInS2.
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Affiliation(s)
- Jia-Yaw Chang
- Department of Chemical Engineering, National Taiwan University of Science and Technology , Section 4, #43, Keelung Road, Taipei 106, Taiwan , Republic of China
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25
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Liu DG, Chao CH, Chang CH, Juang JM, Liu CY, Chang SH, Chang CF, Chou CK, Tseng CC, Chiang CH, Jean YC, Tang MT, Chung SC, Chang SL. Microbeam MAD Beamline for Challenging Protein Crystallography in TPS. ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/425/1/012004] [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: 11/12/2022]
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26
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Tanaka A, Chang CF, Buchholz M, Trabant C, Schierle E, Schlappa J, Schmitz D, Ott H, Metcalf P, Tjeng LH, Schüßler-Langeheine C. Symmetry of orbital order in Fe3O4 studied by Fe L(2,3) resonant x-ray diffraction. Phys Rev Lett 2012; 108:227203. [PMID: 23003646 DOI: 10.1103/physrevlett.108.227203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Indexed: 06/01/2023]
Abstract
We studied the symmetry of the Fe 3d wave function in magnetite below the Verwey temperature T(V) with resonant soft-x-ray diffraction. Although the lattice structure of the low-temperature phase of Fe(3)O(4) is well described by the pseudo-orthorhombic Pmca with a slight monoclinic P2/c distortion, we find that the 3d wave function does not reflect the Pmca symmetry, and its distortion toward monoclinic symmetry is by far larger than that of the lattice. The result supports a scenario in which the Verwey transition involves the ordering of t(2g) orbitals with complex-number coefficients.
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Affiliation(s)
- A Tanaka
- Department of Quantum Matters, ADSM, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
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27
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Chang CF, Huang HJ, Lee HC, Hung KC, Wu RT, Lin AMY. Melatonin attenuates kainic acid-induced neurotoxicity in mouse hippocampus via inhibition of autophagy and α-synuclein aggregation. J Pineal Res 2012; 52:312-21. [PMID: 22212051 DOI: 10.1111/j.1600-079x.2011.00945.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this study, the protective effect of melatonin on kainic acid (KA)-induced neurotoxicity involving autophagy and α-synuclein aggregation was investigated in the hippocampus of C57/BL6 mice. Our data showed that intraperitoneal injection of KA (20 mg/kg) increased LC3-II levels (a hallmark protein of autophagy) and reduced mitochondrial DNA content and cytochrome c oxidase levels (a protein marker of mitochondria). Atg7 siRNA transfection prevented KA-induced LC3-II elevations and mitochondria loss. Furthermore, Atg7 siRNA attenuated KA-induced activation of caspases 3/12 (biomarkers of apoptosis) and hippocampal neuronal loss, suggesting a pro-apoptotic role of autophagy in the KA-induced neurotoxicity. Nevertheless, KA-induced α-synuclein aggregation was not affected in the Atg7 siRNA-transfected hippocampus. The neuroprotective effect of melatonin (50 mg/kg) orally administered 1 hr prior to KA injection was studied. Melatonin was found to inhibit KA-induced autophagy-lysosomal activation by reducing KA-induced increases in LC3-II, lysosomal-associated membrane protein 2 (a biomarker of lysosomes) and cathepsin B (a lysosomal cysteine protease). Subsequently, KA-induced mitochondria loss was prevented in the melatonin-treated mice. At the same time, melatonin reduced KA-increased HO-1 levels and α-synuclein aggregation. Our immunoprecipitation study showed that melatonin enhanced ubiquitination of α-synuclein monomers and aggregates. The anti-apoptotic effect of melatonin was demonstrated by attenuating KA-induced DNA fragmentation, activation of caspases 3/12, and neuronal loss. Taken together, our study suggests that KA-induced neurotoxicity may be mediated by autophagy and α-synuclein aggregation. Moreover, melatonin may exert its neuroprotection via inhibiting KA-induced autophagy and a subsequent mitochondrial loss as well as reducing α-synuclein aggregation by enhancing α-synuclein ubiquitination in the CNS.
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Affiliation(s)
- Chia-Fu Chang
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
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28
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Schlappa J, Chang CF, Hu Z, Schierle E, Ott H, Weschke E, Kaindl G, Huijben M, Rijnders G, Blank DHA, Tjeng LH, Schüssler-Langeheine C. Resonant soft x-ray scattering from stepped surfaces of SrTiO3. J Phys Condens Matter 2012; 24:035501. [PMID: 22179392 DOI: 10.1088/0953-8984/24/3/035501] [Citation(s) in RCA: 5] [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: 05/31/2023]
Abstract
We studied the resonant diffraction signal from stepped surfaces of SrTiO(3) at the Ti 2p → 3d (L(2,3)) resonance in comparison with x-ray absorption (XAS) and specular reflectivity data. The steps on the surface form an artificial superstructure suitable as a model system for resonant soft x-ray diffraction. A small step density on the surface is sufficient to produce a well defined diffraction peak. We determined the optical parameters of the sample across the resonance and found that the differences between the energy dependence of the x-ray absorption signal, the specular reflectivity and the step-related peak reflect the different quantities probed in these signals. When recorded at low incidence or detection angles, XAS and specular reflectivity spectra are strongly distorted by the changes of the angle of total reflection with energy. The resonant diffraction spectrum is less affected and can be used as a spectroscopic probe even in less favorable geometries.
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Affiliation(s)
- J Schlappa
- II. Physikalisches Institut, Universität zu Köln, Köln, Germany.
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Li JW, Wang GP, Fan JY, Chang CF, Xu CS. Eight paths of ERK1/2 signalling pathway regulating hepatocyte proliferation in rat liver regeneration. J Genet 2011; 90:435-442. [PMID: 22227930] [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: 05/31/2023]
Abstract
Although it is known that hormones, growth factors and integrin promote hepatocyte proliferation in liver regeneration (LR) through ERK1/2 signalling pathway, reports about regulating processes of its intracellular paths in hepatocytes of LR are limited. This study aims at exploring which paths of ERK1/2 signalling pathway participate in the regulation of rat LR, especially in hepatocyte proliferation, and how they do so. In all, 14 paths and 165 genes are known to be involved in ERK1/2 signalling pathway. Of them, 161 genes are included in Rat Genome 230 2.0 Array. This array was used to detect expression changes of genes related to ERK1/2 signalling pathway in isolated hepatocytes of rat LR, showing that 60 genes were related to hepatocytes of LR. In addition, bioinformatics and systems biology methods were used to analyse the roles of 14 above paths in regenerating hepatocytes. We found that three paths, RTK→SHC→GRB2/SOS→RAS→RAF, IntegrinΒ→FAK→RAC→PAK→RAF and GΒγ→PI3KΒγ→RAC→PAK→RAF, promoted the G1 phase progression of hepatocytes by activating ERK1/2. A further four paths, Gq→PLCΒ→PKC→SRC/PYK2→GRB2/SOS→RAS→RAF, RTK→PLCγ→PKC→SRC/PYK2→GRB2/SOS→RAS→RAF, IntegrinΒ→FAK/SRC→GRB2/SOS→RAS→RAF and IntegrinΒ→FAK→RAC→PAK→RAF, advanced the cell progression of S phase and G(2)/M checkpoint by activating ERK1/2, and so did PP1/2→Mek1/2 by decreasing the negative influence on ERK1/2. At the late phase of LR, Gαs→AC→EPAC→Rap1→Raf blocked hepatocyte proliferation by decreasing the activity of ERK1/2 and so did PP1/2→Mek1/2. In summary, 60 genes and 8 paths of ERK1/2 signalling pathway regulated hepatocyte proliferation in rat LR.
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Affiliation(s)
- J W Li
- College of Life Sciences, Henan Normal University, Xinxiang 453007, Henan Province, People's Republic of China
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Thangaraj S, Tsao WS, Luo YW, Lee YJ, Chang CF, Lin CC, Uang BJ, Yu CC, Guh JH, Teng CM. Total synthesis of moniliformediquinone and calanquinone A as potent inhibitors for breast cancer. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.06.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Xu CS, Chen XG, Chang CF, Wang GP, Wang WB, Zhang LX, Zhu QS, Wang L. Differential gene expression and functional analysis of pit cells from regenerating rat liver. Genet Mol Res 2011; 10:678-92. [PMID: 21523657 DOI: 10.4238/vol10-2gmr1052] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hepatic pit cells are a population of large granular lymphocytes that substantially contribute to hepatic immunity. Studies have proven that pit cells have a role in liver regeneration, but the details of the relationship between pit cells and liver regeneration is not clear at present. We subjected rats to a two-third hepatectomy; pit cells with high purity were obtained with Percoll density centrifugation and immunomagnetic bead methods, and the changes in mRNA levels in pit cells from the regenerating liver were monitored up to 168 h using a Rat Genome 230 2.0 Array composed of 25,020 distinct rat liver cDNA clones. Of the 25,020 genes analyzed, 612 known and 358 unknown genes were identified to be associated with liver regeneration. The 612 known genes are classified into up-regulation and down-regulation patterns based on the expression levels; they primarily participate in at least 23 biological activities based on gene ontology analysis. Together with gene function enrichment analysis, cytokines and a growth factor-mediated pathway in pit cells were activated at an early phase of liver regeneration; pit cell proliferation occurred from 24-72 h after liver hepatectomy; the machinery of pit cell differentiation commenced early and came into play late; an immune/inflammatory response was enhanced late. Expression pattern analysis of functionally classified genes in pit cells can give insights into the relationship between pit cells and liver regeneration.
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Affiliation(s)
- C S Xu
- College of Life Science, Henan Normal University, Xinxiang, China.
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Chang CF, Huang CY, Huang YC, Lin KY, Lee YJ, Wang CJ. Total Synthesis of (±)-Armepavines and (±)-Nuciferines From (2-Nitroethenyl)benzene Derivatives. SYNTHETIC COMMUN 2010. [DOI: 10.1080/00397910903435411] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Chia-Fu Chang
- a Department of Chemistry , National Changhua University of Education , Changhua, Taiwan
| | - Chu-Yun Huang
- a Department of Chemistry , National Changhua University of Education , Changhua, Taiwan
| | - Yu-Chao Huang
- a Department of Chemistry , National Changhua University of Education , Changhua, Taiwan
| | - Kuan-Yu Lin
- a Department of Chemistry , National Changhua University of Education , Changhua, Taiwan
| | - Yean-Jang Lee
- a Department of Chemistry , National Changhua University of Education , Changhua, Taiwan
| | - Chau-Jong Wang
- b Institute of Biochemistry , Chung Shan Medical University , Taichung, Taiwan
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Chang CF, Hu Z, Wu H, Burnus T, Hollmann N, Benomar M, Lorenz T, Tanaka A, Lin HJ, Hsieh HH, Chen CT, Tjeng LH. Spin blockade, orbital occupation, and charge ordering in La1.5Sr0.5CoO4. Phys Rev Lett 2009; 102:116401. [PMID: 19392219 DOI: 10.1103/physrevlett.102.116401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Indexed: 05/27/2023]
Abstract
Using Co-L2,3 and O-K x-ray absorption spectroscopy, we reveal that the charge ordering in La1.5Sr0.5CoO4 involves high spin (S=3/2) Co2+ and low spin (S=0) Co3+ ions. This provides evidence for the spin-blockade phenomenon as a source for the extremely insulating nature of the La2-xSrxCoO4 series. The associated e{g}{2} and e{g}{0} orbital occupation accounts for the large contrast in the Co-O bond lengths and, in turn, the high charge ordering temperature. Yet, the low magnetic ordering temperature is naturally explained by the presence of the nonmagnetic (S=0) Co3+ ions. From the identification of the bands we infer that La1.5Sr0.5CoO4 is a narrow band material.
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Affiliation(s)
- C F Chang
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
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Hossain MA, Hu Z, Haverkort MW, Burnus T, Chang CF, Klein S, Denlinger JD, Lin HJ, Chen CT, Mathieu R, Kaneko Y, Tokura Y, Satow S, Yoshida Y, Takagi H, Tanaka A, Elfimov IS, Sawatzky GA, Tjeng LH, Damascelli A. Crystal-field level inversion in lightly Mn-doped Sr3Ru2O7. Phys Rev Lett 2008; 101:016404. [PMID: 18764131 DOI: 10.1103/physrevlett.101.016404] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Indexed: 05/26/2023]
Abstract
Sr3(Ru(1-x)Mnx)2O7, in which 4d-Ru is substituted by the more localized 3d-Mn, is studied by x-ray dichroism and spin-resolved density functional theory. We find that Mn impurities do not exhibit the same 4+ valence of Ru, but act as 3+ acceptors; the extra eg electron occupies the in-plane 3d(x2-y2) orbital instead of the expected out-of-plane 3d(3z2-r2). We propose that the 3d-4d interplay, via the ligand oxygen orbitals, is responsible for this crystal-field level inversion and the material's transition to an antiferromagnetic, possibly orbitally ordered, low-temperature state.
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Affiliation(s)
- M A Hossain
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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Chang CF, Yang LY, Chang SW, Fang YT, Lee YJ. Total synthesis of demethylwedelolactone and wedelolactone by Cu-mediated/Pd(0)-catalysis and oxidative-cyclization. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.02.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hansmann P, Severing A, Hu Z, Haverkort MW, Chang CF, Klein S, Tanaka A, Hsieh HH, Lin HJ, Chen CT, Fåk B, Lejay P, Tjeng LH. Determining the crystal-field ground state in rare earth heavy fermion materials using soft-x-ray absorption spectroscopy. Phys Rev Lett 2008; 100:066405. [PMID: 18352496 DOI: 10.1103/physrevlett.100.066405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Indexed: 05/26/2023]
Abstract
We infer that soft-x-ray absorption spectroscopy is a versatile method for the determination of the crystal-field ground state symmetry of rare earth heavy fermion systems, complementing neutron scattering. Using realistic and universal parameters, we provide a theoretical mapping between the polarization dependence of Ce M(4,5) spectra and the charge distribution of the Ce 4f states. The experimental resolution can be orders of magnitude larger than the 4f crystal-field splitting itself. To demonstrate the experimental feasibility of the method, we investigated CePd2Si2, thereby settling an existing disagreement about its crystal-field ground state.
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Affiliation(s)
- P Hansmann
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
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Schlappa J, Schüssler-Langeheine C, Chang CF, Ott H, Tanaka A, Hu Z, Haverkort MW, Schierle E, Weschke E, Kaindl G, Tjeng LH. Direct observation of t2g orbital ordering in magnetite. Phys Rev Lett 2008; 100:026406. [PMID: 18232896 DOI: 10.1103/physrevlett.100.026406] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Indexed: 05/12/2023]
Abstract
Using soft-x-ray diffraction at the site-specific resonances in the Fe L2,3 edge, we find clear evidence for orbital and charge ordering in magnetite below the Verwey transition. The spectra show directly that the (001/2) diffraction peak (in cubic notation) is caused by t2g orbital ordering at octahedral Fe2+ sites and the (001) by a spatial modulation of the t2g occupation.
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Affiliation(s)
- J Schlappa
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
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Xu CS, Chang CF. Expression profiles of the genes associated with metabolism and transport of amino acids and their derivatives in rat liver regeneration. Amino Acids 2007; 34:91-102. [PMID: 17713745 DOI: 10.1007/s00726-007-0576-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [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: 06/05/2007] [Accepted: 06/21/2007] [Indexed: 12/31/2022]
Abstract
Amino acids (AA) are components of protein and precursors of many important biological molecules. To address effects of the genes associated with metabolism and transport of AA and their derivatives during rat liver regeneration (LR), we firstly obtained the above genes by collecting databases data and retrieving related thesis, and then analyzed their expression profiles during LR using Rat Genome 230 2.0 array. The LR-associated genes were identified by comparing the gene expression difference between partial hepatectomy (PH) and sham-operation (SO) rat livers. It was approved that 134 genes associated with metabolism of AA and their derivatives and 26 genes involved in transport of them were LR-associated. The initially and totally expressing number of these genes occurring in initial phase of LR (0.5-4 h after PH), G0/G1 (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and structure-function reconstruction of liver tissue (72-168 h after PH) were respectively 76, 17, 79, 5 and 162, 89, 564, 195, illustrating that these LR-associated genes were initially expressed mainly in initial stage, and functioned in different phases. Frequencies of up-regulation and down-regulation of them being separately 564 and 357 demonstrated that genes up-regulated outnumbered those down-regulated. Categorization of their expression patterns into 22 types implied the diversity of cell physiological and biochemical activities. According to expression changes and patterns of the above-mentioned genes in LR, it was presumed that histidine biosynthesis in the metaphase and anaphase, valine metabolism in the anaphase, and metabolism of glutamate, glutamine, asparate, asparagine, methionine, alanine, leucine and aromatic amino acid almost were enhanced in the whole LR; as for amino acid derivatives, transport of neutral amino acids, urea, gamma-aminobutyric acid, betaine and taurine, metabolism of dopamine, heme, S-adenosylmethionine, thyroxine, and biosynthesis of hydroxyproline, nitric oxide, orinithine, polyamine, carnitine, selenocysteine were augmented during the entire liver restoration. Above results showed that metabolism and transport of AA and their derivates were necessary in liver regeneration.
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Affiliation(s)
- C S Xu
- College of Life Science, Henan Normal University, Xinxiang, China.
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Abstract
One of the most pressing issues in facing emerging and re-emerging respiratory infections is how to bring them under control with current public health measures. Approaches such as the Wells-Riley equation, competing-risks model, and Von Foerster equation are used to prioritize control-measure efforts. Here we formulate how to integrate those three different types of functional relationship to construct easy-to-use and easy-to-interpret critical-control lines that help determine optimally the intervention strategies for containing airborne infections. We show that a combination of assigned effective public health interventions and enhanced engineering control measures would have a high probability for containing airborne infection. We suggest that integrated analysis to enhance modelling the impact of potential control measures against airborne infections presents an opportunity to assess risks and benefits. We demonstrate the approach with examples of optimal control measures to prioritize respiratory infections of severe acute respiratory syndrome (SARS), influenza, measles, and chickenpox.
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Affiliation(s)
- C M Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, ROC.
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Schüssler-Langeheine C, Schlappa J, Tanaka A, Hu Z, Chang CF, Schierle E, Benomar M, Ott H, Weschke E, Kaindl G, Friedt O, Sawatzky GA, Lin HJ, Chen CT, Braden M, Tjeng LH. Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction. Phys Rev Lett 2005; 95:156402. [PMID: 16241744 DOI: 10.1103/physrevlett.95.156402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Indexed: 05/05/2023]
Abstract
Strong resonant enhancements of the charge-order and spin-order superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The pronounced photon-energy and polarization dependences of these diffraction intensities allow for a critical determination of the local symmetry of the ordered spin and charge carriers. We found that not only the antiferromagnetic order but also the charge-order superstructure resides within the NiO2 layers; the holes are mainly located on in-plane oxygens surrounding a Ni2+ site with the spins coupled antiparallel in close analogy to Zhang-Rice singlets in the cuprates.
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Affiliation(s)
- C Schüssler-Langeheine
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
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Chiou CS, Chang CF, Chang CY, Wu YP, Chang CT, Li YS, Chen YH. Mineralization of polyethylene glycol in aqueous solution by hydrogen peroxide with basic oxygen furnace slag. Environ Technol 2004; 25:1357-1365. [PMID: 15691196 DOI: 10.1080/09593332508618468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study evaluated the dissolution behavior of basic oxygen furnace slag (BOF slag) and the performance of H2O2 with BOF slag denoted as H2O2/BOF slag process to degrade polyethylene glycol (PEG) in the aqueous solution. The concentration of total organic carbon (TOC) was chosen as a mineralization index of the degradation of PEG by the H2O2/BOF slag process. A first-order kinetic model with respect to TOC was adopted to represent the mineralization of PEG by H2O2/BOF slag process. The experimental results in this study suggested that dosages with 3.98 x 10(-4) mole min(-1) l(-1) H2O2 and 15 g l(-1) BOF slag loading in the solution at pH 2 provided the optimal operation conditions for the mineralization of PEG yielding a 75.5% treatment efficiency at 100 min reaction time. The H2O2/Fe2+ ratio was then determined to be 13.5:1.
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Affiliation(s)
- C S Chiou
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan
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Huang DJ, Chang CF, Jeng HT, Guo GY, Lin HJ, Wu WB, Ku HC, Fujimori A, Takahashi Y, Chen CT. Spin and orbital magnetic moments of Fe3O4. Phys Rev Lett 2004; 93:077204. [PMID: 15324271 DOI: 10.1103/physrevlett.93.077204] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Indexed: 05/24/2023]
Abstract
We present measurements of the spin and orbital magnetic moments of Fe3O4 by using SQUID and magnetic circular dichroism in soft x-ray absorption. The measurements show that Fe3O4 has a noninteger spin moment, in contrast to its predicted half-metallic feature. Fe3O4 also exhibits a large unquenched orbital moment. Calculations using the local density approximation including the Hubbard U method and the configuration interaction cluster-model suggest that strong correlations and spin-orbit interaction of the 3d electrons result in the noninteger spin and large orbital moments of Fe3O4.
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Affiliation(s)
- D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan
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Tsai WT, Chang CY, Ing CH, Chang CF. Adsorption of acid dyes from aqueous solution on activated bleaching earth. J Colloid Interface Sci 2004; 275:72-8. [PMID: 15158382 DOI: 10.1016/j.jcis.2004.01.072] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Accepted: 01/29/2004] [Indexed: 11/15/2022]
Abstract
In the present study, activated bleaching earth was used as clay adsorbent for an investigation of the adsorbability and adsorption kinetics of acid dyes (i.e., acid orange 51, acid blue 9, and acid orange 10) with three different molecular sizes from aqueous solution at 25 degrees C in a batch adsorber. The rate of adsorption has been investigated under the most important process parameters (i.e., initial dye concentration). A simple pseudo-second-order model has been tested to predict the adsorption rate constant, equilibrium adsorbate concentration, and equilibrium adsorption capacity by the fittings of the experimental data. The results showed that the adsorbability of the acid acids by activated bleaching earth follows the order: acid orange 51 > acid blue 9 > acid orange 10, parallel to the molecular weights and molecular sizes of the acid dyes. The adsorption removals (below 3%) of acid blue 9 and acid orange 10 onto the clay adsorbent are far lower than that (approximately 24%) of acid orange 51. Further, the adsorption kinetic of acid orange 51 can be well described by the pseudo-second-order reaction model. Based on the isotherm data obtained from the fittings of the adsorption kinetics, the Langmuir model appears to fit the adsorption better than the Freundlich model. The external coefficients of mass transfer of the acid orange 51 molecule across the boundary layer of adsorbent particle have also been estimated at the order of 10(-4)-10(-5) cm s(-1) based on the film-pore model and pseudo-second-order reaction model.
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Affiliation(s)
- W T Tsai
- Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan.
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Chen YH, Chang CY, Chen CC, Chiu CY, Yu YH, Chiang PC, Ku Y, Chen JN, Chang CF. Decomposition of 2-mercaptothiazoline in aqueous solution by ozonation. Chemosphere 2004; 56:133-140. [PMID: 15120559 DOI: 10.1016/j.chemosphere.2004.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Revised: 10/31/2003] [Accepted: 02/05/2004] [Indexed: 05/24/2023]
Abstract
This study investigates the ozonation of 2-mercaptothiazoline (2-MT). The 2-MT is one of the important organic additives for the electroplating solution of the printed wiring board industry and has been widely used as a corrosion inhibitor in many industrial processes. It is of concern for the aquatic pollution control especially in the wastewaters. Semibatch ozonation experiments in the completely stirred tank reactor are performed under various concentrations of input ozone. The concentrations of 2-MT, sulfate, and ammonium are analyzed at specified time intervals to elucidate the decomposition of 2-MT during the ozonation. In addition, the time variation of the dissolved ozone concentration (C(ALb)) is continuously monitored in the course of experiments. Total organic carbon (TOC) is chosen and measured as a mineralization index of the ozonation of 2-MT. The results indicate that the decomposition of 2-MT is efficient, while the mineralization of TOC is limited via the ozonation only. Simultaneously, the yield of sulfate with the maximum value of about 47% is characterized by the increases of TOC removal and ozone consumption. These results can provide some useful information for assessing the feasibility of the treatment of 2-MT in the aqueous solution by the ozonation.
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Affiliation(s)
- Y H Chen
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 106, Taiwan
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Huang DJ, Wu WB, Guo GY, Lin HJ, Hou TY, Chang CF, Chen CT, Fujimori A, Kimura T, Huang HB, Tanaka A, Jo T. Orbital ordering in La0.5Sr1.5MnO4 studied by soft X-ray linear dichroism. Phys Rev Lett 2004; 92:087202. [PMID: 14995808 DOI: 10.1103/physrevlett.92.087202] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Revised: 11/17/2003] [Indexed: 05/24/2023]
Abstract
We found that the conventional model of orbital-ordering of 3x(2)-r(2)/3y(2)-r(2) type in the e(g) states of La0.5Sr1.5MnO4 is incompatible with measurements of linear dichroism in the Mn 2p-edge x-ray absorption, whereas these e(g) states exhibit predominantly cross-type orbital ordering of x(2)-z(2)/y(2)-z(2). LDA+U band-structure calculations reveal that such a cross-type orbital-ordering results from a combined effect of antiferromagnetic structure, Jahn-Teller distortion, and on-site Coulomb interactions.
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Affiliation(s)
- D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan
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Harvey BK, Chang CF, Chiang YH, Bowers WJ, Morales M, Hoffer BJ, Wang Y, Federoff HJ. HSV amplicon delivery of glial cell line-derived neurotrophic factor is neuroprotective against ischemic injury. Exp Neurol 2003; 183:47-55. [PMID: 12957487 DOI: 10.1016/s0014-4886(03)00080-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [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: 11/24/2022]
Abstract
Direct intracerebral administration of glial cell line-derived neurotrophic factor (GDNF) is neuroprotective against ischemia-induced cerebral injury. Utilizing viral vectors to deliver and express therapeutic genes presents an opportunity to produce GDNF within localized regions of an evolving infarct. We investigated whether a herpes simplex virus (HSV) amplicon-based vector encoding GDNF (HSVgdnf) would protect neurons against ischemic injury. In primary cortical cultures HSVgdnf reduced oxidant-induced injury compared to the control vector HSVlac. To test protective effects in vivo, HSVgdnf or HSVlac was injected into the cerebral cortex 4 days prior to, or 3 days, after a 60-min unilateral occlusion of the middle cerebral artery. Control stroke animals developed bradykinesia and motor asymmetry; pretreatment with HSVgdnf significantly reduced such motor deficits. Animals receiving HSVlac or HSVgdnf after the ischemic insult did not exhibit any behavioral improvement. Histological analyses performed 1 month after stroke revealed a reduction in ischemic tissue loss in rats pretreated with HSVgdnf. Similarly, these animals exhibited less immunostaining for glial fibrillary acidic protein and the apoptotic marker caspase-3. Taken together, our data indicate that HSVgdnf pretreatment provides protection against cerebral ischemia and supports the utilization of the HSV amplicon for therapeutic delivery of trophic factors to the CNS.
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Affiliation(s)
- B K Harvey
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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Sarabi A, Chang CF, Wang Y, Tomac AC, Hoffer BJ, Morales M. Differential expression of the cell line-derived neurotrophic factor (GDNF) receptor GFRalpha1 in heterozygous Gfralpha1 null-mutant mice after stroke. Neurosci Lett 2003; 341:241-5. [PMID: 12697293 DOI: 10.1016/s0304-3940(03)00195-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Exogenous administration of glial cell line-derived neurotrophic factor (GDNF) reduces ischemia-induced cerebral infarction. Cerebral ischemia induces gene expression of GDNF, GDNF-receptor alpha-1 (GFRalpha-1) and c-Ret, suggesting that a GDNF signaling cascade mechanism may be involved in endogenous neuroprotection during ischemia. In the present study, we examined if this endogenous neuroprotective pathway was altered in Gfralpha-1 deficient mice. Since mice homozygous for the Gfralpha-1 deletion (-/-) die within 24 h of birth, stroke-induced changes in the levels of Gfralpha-1 mRNA were studied in Gfralpha-1 heterozygous (+/-) mice and their wild-type (+/+) littermates. The right middle cerebral artery was transiently ligated for 45 min in anesthetized mice. Animals were killed at 0, 6, 12 and 24 h after the onset of reperfusion and levels of Gfralpha-1 mRNA were measured by in situ hybridization histochemistry. Previously, we showed that Gfralpha-1 (+/-) mice are more vulnerable to focal cerebral ischemia. In the present study, we found that basal levels of GFRalpha-1 mRNA were at similar low levels in cortex and striatum in adult Gfralpha-1 (+/+) and Gfralpha-1 (+/-) mice and that ischemia/reperfusion induced up-regulation of Gfralpha-1 mRNA in the lesioned and contralateral sides of cortex and striatum in both Gfralpha-1 (+/+) and GFRalpha-1 (+/-) mice. However, the ischemia/reperfusion induction of Gfralpha-1 mRNA was significantly higher in the cortex of wild type mice, as compared to Gfralpha-1 (+/-) mice. Moreover, the increased expression of Gfralpha-1 in striatum after reperfusion occurred earlier in the GFRalpha-1 (+/+) than in the Gfralpha-1 (+/-) mice. These results indicate that after ischemia, there is a differential up-regulation of Gfralpha-1 expression in Gfralpha-1 (+/+) and Gfralpha-1 (+/-) mice. Since GDNF has neuroprotective effects, the reduced up-regulation of Gfralpha-1 in Gfralpha-1 (+/-) mice at early time points after ischemia suggests that the responsiveness to GDNF and GDNF receptor mediated neuroprotection is attenuated in these genetically modified animals and may underlie their greater vulnerability.
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Affiliation(s)
- A Sarabi
- National Institute on Drug Abuse, IRP Department, Cellular Neurophysiology Section, NIH, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA
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Abstract
In the present study, a hydrophobic zeolite was used as an adsorbent for the adsorption of polyethylene glycol (PEG) in water solution and electroplating solution at 25 degrees C. The adsorption capacities were determined through the adsorption isotherms in a thermostated shaker. The rate of adsorption, on the other hand, was investigated in a batch adsorber under controlled process parameters such as initial PEG concentration (30, 70, 110, 150, 200, and 300 mg x dm(-3)), agitation speed (200, 800, and 1000 rpm), and adsorbent particle size (0.72, 1.44, and 2.03 mm). A batch kinetic model, according to a pseudo-second-order mechanism, has been tested to predict the rate constant of adsorption, equilibrium adsorption capacity, time of half-adsorption, and equilibrium concentration by the fitting of the experimental data. The results of the adsorption isotherm and kinetic studies show that the adsorption process can well be described with the Langmuir and Freundlich models and the pseudo-second-order equation, respectively. Comparing the values of adsorption parameters of PEG in water solution and electroplating solution, there are no significant differences. In addition, the effective diffusion coefficient of the PEG molecule in the microporous adsorbent has been estimated at about 3.20 x 10(-8) cm(2)s(-1) based on the restrictive diffusion model.
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Affiliation(s)
- C Y Chang
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC
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