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Hu SX, Ceurvorst L, Peebles JL, Mao A, Li P, Lu Y, Shvydky A, Goncharov VN, Epstein R, Nichols KA, Goshadze RMN, Ghosh M, Hinz J, Karasiev VV, Zhang S, Shaffer NR, Mihaylov DI, Cappelletti J, Harding DR, Li CK, Campbell EM, Shah RC, Collins TJB, Regan SP, Deeney C. Laser-direct-drive fusion target design with a high-Z gradient-density pusher shell. Phys Rev E 2023; 108:035209. [PMID: 37849111 DOI: 10.1103/physreve.108.035209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023]
Abstract
Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.
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Affiliation(s)
- S X Hu
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - L Ceurvorst
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J L Peebles
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - A Mao
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - P Li
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Y Lu
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - A Shvydky
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - R Epstein
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - K A Nichols
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - R M N Goshadze
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - M Ghosh
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Hinz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - V V Karasiev
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - S Zhang
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - N R Shaffer
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - D I Mihaylov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Cappelletti
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - D R Harding
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - C K Li
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - E M Campbell
- MCM Consulting, San Diego, California 97127, USA
| | - R C Shah
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - T J B Collins
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - C Deeney
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
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Gu X, Nardone C, Kamitaki N, Mao A, Elledge SJ, Greenberg ME. The midnolin-proteasome pathway catches proteins for ubiquitination-independent degradation. Science 2023; 381:eadh5021. [PMID: 37616343 PMCID: PMC10617673 DOI: 10.1126/science.adh5021] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/11/2023] [Indexed: 08/26/2023]
Abstract
Cells use ubiquitin to mark proteins for proteasomal degradation. Although the proteasome also eliminates proteins that are not ubiquitinated, how this occurs mechanistically is unclear. Here, we found that midnolin promoted the destruction of many nuclear proteins, including transcription factors encoded by the immediate-early genes. Diverse stimuli induced midnolin, and its overexpression was sufficient to cause the degradation of its targets by a mechanism that did not require ubiquitination. Instead, midnolin associated with the proteasome via an α helix, used its Catch domain to bind a region within substrates that can form a β strand, and used a ubiquitin-like domain to promote substrate destruction. Thus, midnolin contains three regions that function in concert to target a large set of nuclear proteins to the proteasome for degradation.
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Affiliation(s)
- Xin Gu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher Nardone
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Nolan Kamitaki
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Aoyue Mao
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Stephen J. Elledge
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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3
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Nardone C, Palanski BA, Scott DC, Timms RT, Barber KW, Gu X, Mao A, Leng Y, Watson EV, Schulman BA, Cole PA, Elledge SJ. A central role for regulated protein stability in the control of TFE3 and MITF by nutrients. Mol Cell 2023; 83:57-73.e9. [PMID: 36608670 PMCID: PMC9908011 DOI: 10.1016/j.molcel.2022.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [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: 07/18/2022] [Revised: 10/24/2022] [Accepted: 12/13/2022] [Indexed: 01/07/2023]
Abstract
The TFE3 and MITF master transcription factors maintain metabolic homeostasis by regulating lysosomal, melanocytic, and autophagy genes. Previous studies posited that their cytosolic retention by 14-3-3, mediated by the Rag GTPases-mTORC1, was key for suppressing transcriptional activity in the presence of nutrients. Here, we demonstrate using mammalian cells that regulated protein stability plays a fundamental role in their control. Amino acids promote the recruitment of TFE3 and MITF to the lysosomal surface via the Rag GTPases, activating an evolutionarily conserved phospho-degron and leading to ubiquitination by CUL1β-TrCP and degradation. Elucidation of the minimal functional degron revealed a conserved alpha-helix required for interaction with RagA, illuminating the molecular basis for a severe neurodevelopmental syndrome caused by missense mutations in TFE3 within the RagA-TFE3 interface. Additionally, the phospho-degron is recurrently lost in TFE3 genomic translocations that cause kidney cancer. Therefore, two divergent pathologies converge on the loss of protein stability regulation by nutrients.
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Affiliation(s)
- Christopher Nardone
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Brad A Palanski
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel C Scott
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Richard T Timms
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, Cambridgeshire CB2 0AW, UK
| | - Karl W Barber
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Xin Gu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Aoyue Mao
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Yumei Leng
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Emma V Watson
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany
| | - Philip A Cole
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen J Elledge
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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Zhang N, Zhou J, Wang L, Zhang T, Zhu W, Mao A, Pan Q, Lin Z, Wang M, Zhang Y, Feng Y, Xu W, Zhao Y, Wang L. 162P Efficacy and safety of GEMOX (gemcitabine plus oxaliplatin) plus sintilimab and bevacizumab as a conversion therapy in patients with initially unresectable biliary tract cancers (BTC): A single-arm, phase II study. Immuno-Oncology and Technology 2022. [DOI: 10.1016/j.iotech.2022.100274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Wang L, Wang L, Zhang T, Zhao Y, Mao A, Zhu W, Zhang N. P-110 Safety and efficacy of GEMOX plus donafenib and tislelizumab as first-line therapy for advanced epithelial malignant biliary tract cancer. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.04.200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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6
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Wen L, Mao A, Jiao F, Zhang D, Xie J, He K. Detection of porcine circovirus-like virus P1 in Hebei, China. Transbound Emerg Dis 2018; 65:1133-1136. [PMID: 29761653 DOI: 10.1111/tbed.12896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Indexed: 11/29/2022]
Abstract
Porcine circovirus-like virus P1 is a novel unclassified circovirus that was first detected in China and may be associated with post-weaning multisystemic wasting syndrome (PMWS) and congenital tremor. In this study, we detected P1 infection in pigs in Hebei Province, China, in 2017. One hundred and forty of 500 (28.0%) serum samples from 25 pig farms with different PMWS status in seven cities were P1 positive on PCR. Twelve P1 strains were sequenced, and the complete genomes of 11 P1 strains were 648 nucleotides (nt) in length, whereas that of strain ZJK02 was 647 nt, with a G deletion at position of 183 in its genome. The complete genomic and capsid protein sequences of the 12 P1 strains analysed in this study shared 98.8%-100.0% and 86.5%-100.0% identity, respectively. A phylogenetic analysis based on the complete genomic and capsid sequences of 26 P1 strains showed that the 12 P1 sequences from Hebei Province clustered on two small branches. Further studies of the evolution and pathogenesis of P1 are required.
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Affiliation(s)
- L Wen
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
| | - A Mao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
| | - F Jiao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
| | - D Zhang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
| | - J Xie
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
| | - K He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology, Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses, Yangzhou, China
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7
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Affiliation(s)
- L. Wen
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base; Nanjing China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou China
| | - A. Mao
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base; Nanjing China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou China
| | - X. Zhu
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base; Nanjing China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou China
| | - J. Xie
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base; Nanjing China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou China
| | - K. He
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences·Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture·Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base; Nanjing China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou China
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8
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Wen L, Mao A, Jiao F, Zhang D, Xie J, He K. Evidence of porcine circovirus-like virus P1 in piglets with an unusual congenital tremor. Transbound Emerg Dis 2017; 65:e501-e504. [DOI: 10.1111/tbed.12772] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Indexed: 01/07/2023]
Affiliation(s)
- L. Wen
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
| | - A. Mao
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
| | - F. Jiao
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
| | - D. Zhang
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
| | - J. Xie
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
| | - K. He
- Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Institute of Veterinary Medicine; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing China
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Wen L, Mao A, Fan Z, Li W, Xiao Q, Liu Q, Xie J, He K. Porcine circovirus-like virus P1 in cattle, goats and rabbits in China. Transbound Emerg Dis 2017; 65:e217-e218. [DOI: 10.1111/tbed.12716] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Indexed: 12/01/2022]
Affiliation(s)
- L. Wen
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - A. Mao
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - Z. Fan
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - W. Li
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - Q. Xiao
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - Q. Liu
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - J. Xie
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
| | - K. He
- Institute of Veterinary Medicine; Jiangsu Academy of Agricultural Sciences Key Laboratory of Animal Diseases, Diagnostics, and Immunology; Ministry of Agriculture National Center for Engineering Research of Veterinary Bio-products; Nanjing Jiangsu China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infections Diseases and Zoonoses; Yangzhou Jiangsu China
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Abstract
The aim of the research presented here was to investigate the immunoloregulatory effects of 5 saponins: Saikosaponins A (SSA) and D (SSD) from Bupleurum chinese DC (Umbelliferae), Panax Notoginseng Saponin (PNS) and Notoginsenoside R1 from Panax notoginseng (Araliaceae) (SR1), and Anemoside B4 from Pulsatilla chinensis Regel (Ranunculaceae) (AB4). To achieve this, endothelial cells were challenged with 10(5) TCID50/mL PRRSV for 24 h then treated respectively with 5 saponins at 3 concentrations (1, 5 and 10 μg/mL). The cells were incubated at 37°C in a cell incubator for 24 h. The supernatants were collected and analyzed the levels of interleukin-4 (IL-4), IL-10, IL-2, and γ-interferon (IFN-γ) by ELISA kits. The results revealed that PNS and SR1 inhibited the production of IL-4; PNS, SR1 and SSD inhibited the secretion of IL-10; SSA, SSD and AB4 up-regulated IL-2 expression; SSA and SSD increased the level of IFN-γ. All these changes were significant. Taken together, the data suggested that these 5 saponins might effectively regulate immune responses via changes in the levels of these select cytokines.
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Affiliation(s)
- Y Hu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, China
| | - A Mao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, China
| | - Y Tan
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, China
| | - Y Zhao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, China
| | - K He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, China
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Han Z, Wang Y, Chi Y, Yan S, Mao A, Zhong-Chao H. Long-term culture of human umbilical cord mesenchymal stem cells in defined serum free media. Cytotherapy 2014. [DOI: 10.1016/j.jcyt.2014.01.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Wang Y, Han Z, Zhang Z, Chi Y, Yang Z, Yang S, Yan S, Mao A, Zhang J, Xu F, Liang L, Zhang Q, Yang Y, Wang S, Meng L, Cui J, Ji Y, Fang X, Zhong-Chao H. Long-term cultured mesenchymal stem cells frequently develop genomic mutations but do not undergo malignant transformation. Cytotherapy 2014. [DOI: 10.1016/j.jcyt.2014.01.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mao A, Schaper CD, Karlicek RF. Nanopatterning using a simple bi-layer lift-off process for the fabrication of a photonic crystal nanostructure. Nanotechnology 2013; 24:085302. [PMID: 23376918 DOI: 10.1088/0957-4484/24/8/085302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A simple and versatile method for fabricating nanopatterns by a lift-off procedure is demonstrated. The technique involves the use of molecular transfer lithography based on water-soluble templates to form a nanopatterned UV-curable material on a PMGI layer, which serves as an underlying resin suitable for lift-off processes. This bi-layer procedure is used for the fabrication of nickel patterns, which are subsequently used as a hard mask for plasma etch processing. Using this procedure, a two-dimensional TiO(2) photonic crystal layer with a 450 nm lattice constant is fabricated on Y(3)Al(5)O(12):Ce(3+) (YAG:Ce) yellow ceramic plate phosphor to enhance its forward emission. The yellow emission in the forward direction is improved by a factor of 3.5 compared to that of a conventional non-scattering YAG:Ce phosphor plate excited by a blue LED.
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Affiliation(s)
- A Mao
- Smart Lighting Engineering Research Center, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
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Faludi M, Mao A, Vinet E, Clarke A, Pineau C, Bernatsky S, Nashi E. B-cell receptor signaling studies in patients with lupus: preliminary results. Arthritis Res Ther 2012. [PMCID: PMC3467537 DOI: 10.1186/ar3994] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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15
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Liu B, Mao A, Liu D. The hypothesis of an effective strategy for resistance of hepatocellular carcinoma to therapy-autophagy. W INDIAN MED J 2011; 60:666-668. [PMID: 22512226] [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
Hepatocellular carcinoma (HCC) is one of the most common malignant tumours and its five-year survival rate remains low. Autophagy is a catabolic process conserved among all eukaryotes ranging from yeast to mammals. Recently, many studies show that tumour cells can utilize autophagy as a cellular defence mechanism when facing metabolic stress. Thus, we hypothesize that autophagy may play an important role in the resistance of hepatocellular carcinomas to therapy. Although the exact role of autophagy on tumour cells is still complex and further studies are needed to prove the impact of autophagy on HCC, it suggests that autophagy may be a new therapeutic target for the resistance to therapy of HCC.
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Affiliation(s)
- B Liu
- Department of Interventional Radiology, St Luke's Hospital, Shanghai 200050, PR China
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16
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Shah S, Ceska R, Gil-Extremera B, Paolini JF, Giezek H, Vandormael K, Mao A, McCrary Sisk C, Maccubbin D. Efficacy and safety of extended-release niacin/laropiprant plus statin vs. doubling the dose of statin in patients with primary hypercholesterolaemia or mixed dyslipidaemia. Int J Clin Pract 2010; 64:727-38. [PMID: 20518948 DOI: 10.1111/j.1742-1241.2010.02370.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Co-administration of niacin with statin offers the potential for additional lipid management and cardiovascular risk reduction. However, niacin is underutilised because of the side effects of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). A combination tablet containing extended-release niacin and laropiprant (ERN/LRPT), a PGD(2) receptor (DP1) antagonist, offers improved tolerability. This study assessed the efficacy and safety of ERN/LRPT added to statin vs. doubling the dose of statin in patients with primary hypercholesterolaemia or mixed dyslipidaemia who were not at their National Cholesterol Education Program Adult Treatment Panel III low-density lipoprotein cholesterol (LDL-C) goal based on their coronary heart disease risk category (high, moderate or low). METHODS After a 2- to 6-week run-in statin (simvastatin 10 or 20 mg or atorvastatin 10 mg) period, 1216 patients were randomised equally to one of two treatment groups in a double-blind fashion: group 1 received ERN/LRPT (1 g) plus the run-in statin dose and advanced to ERN/LRPT (2 g) after 4 weeks for an additional 8 weeks, with no adjustments to the run-in statin dose; group 2 received simvastatin or atorvastatin at twice their run-in statin dose and remained on this stable dose for 12 weeks. RESULTS ERN/LRPT added to statin (pooled across statin and statin dose) significantly improved key lipid parameters vs. the doubled statin dose (pooled): the between-treatment group difference in least squares mean per cent change [95% confidence interval (CI)] from baseline to week 12 in LDL-C (primary end-point) was -4.5% (-7.7, -1.3) and in high-density lipoprotein cholesterol (HDL-C) was 15.6% (13.4, 17.9) and in median per cent change for triglyceride (TG) was -15.4% (-19.2, -11.7). Treatment-related adverse experiences (AEs) related to flushing, pruritis, rash, gastrointestinal upset and elevations in liver transaminases and fasting serum glucose occurred more frequently with ERN/LRPT added to statin vs. statin dose doubled. CONCLUSIONS The addition of ERN/LRPT to ongoing statin treatment produced significantly improved lipid-modifying benefits on LDL-C, HDL-C and TG and all other lipid parameters compared with doubling the statin dose in patients with primary hypercholesterolaemia or mixed dyslipidaemia. The types of AEs that occurred at a greater frequency in the ERN/LRPT group were those typically associated with niacin.
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Affiliation(s)
- S Shah
- Merck Research Laboratories, Cardiovascular Disease, Merck, Sharp & Dohme Corp., Rahway, NJ 07065, USA.
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17
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Zhang WX, Chen B, Jin Z, Yu Z, Wang X, Chen H, Mao A, Cai W. Influence of uridine diphosphate (UDP)-glucuronosyltransferases and ABCC2 genetic polymorphisms on the pharmacokinetics of mycophenolic acid and its metabolites in Chinese renal transplant recipients. Xenobiotica 2008; 38:1422-36. [DOI: 10.1080/00498250802488585] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Day SH, Mao A, White R, Schulz-Utermoehl T, Miller R, Beconi MG. A semi-automated method for measuring the potential for protein covalent binding in drug discovery. J Pharmacol Toxicol Methods 2005; 52:278-85. [PMID: 16125627 DOI: 10.1016/j.vascn.2004.11.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [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: 09/27/2004] [Accepted: 11/15/2004] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Covalent protein binding of metabolically reactive intermediates of drugs has been implicated in drug toxicity including the occurrence of idiosyncratic drug toxicity. Investigators therefore would prefer to avoid developing compounds that produce significant amounts of reactive metabolites. By incubating the radiolabeled drug of interest with liver microsomes it is possible to evaluate the propensity of a drug candidate to covalently bind to proteins. METHODS Here we present a semi-automated method in which a Brandel cell harvester is used to collect and wash proteins that have been incubated with radiolabeled drug. This method utilizes glass fiber filter paper to capture precipitated protein, rather than the more traditional exhaustive extraction/centrifugation approach. Using model compounds (including [14C]diclofenac, [3H]imipramine, [14C]naphthalene, and [14C]L-746530) we compare the covalent binding results obtained using this method to results generated using the traditional method and we performed cross-laboratory testing of assay reproducibility. RESULTS It was found that results from new method correlated highly with the traditional method (R2=0.89). The cross-laboratory testing of the method showed an average interlaboratory coefficient of variation of only 18.4%. DISCUSSION This method provides comparable results to the more traditional centrifugation-based method with considerable time and labor savings.
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Affiliation(s)
- S H Day
- Medicinal Chemistry, Merck Frosst Centre for Therapeutic Research, Merck Frosst Canada and Co., 16711 Trans Canada Hwy., Kirkland, Quebec, Canada H9H 3L1.
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Beconi M, Mao A, Creighton M, Hop CECA, Chiu SHL, Eydelloth R, Franklin R, Tang F, Yu N, Vincent S. Species and gender differences in the formation of an active metabolite of a substituted 2,4-thiazolidinedione insulin sensitizer. Xenobiotica 2003; 33:767-87. [PMID: 12893525 DOI: 10.1080/0049825031000108333] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The metabolism of a substituted 2,4-thiazolidinedione (P1) with dual PPARalpha/gamma activity was evaluated in male and female rats, dogs and monkeys. A para-hydroxylated metabolite (M1) with potent PPARgamma-selective agonist, was a major circulating drug-related component in female rats, dogs and monkeys, but not in male rats (M1-to-P1 exposure ratio of <1, 3-5, 5 and 5-11 in male rat, monkey, female rat, and dog, respectively). 2. M1 (%) formed in vitro (5, 53, 57-65, 67 and 67% in male rat, monkey, female rat, dog, and human liver microsomes, respectively), rank ordered with M1 (%) formed in vivo (24-45, 53-57, 78, 75-85%, for male rat, monkey, female rat and dog, respectively, after oral administration of P1). 3. The plasma clearance of M1 was higher in male rats (32 ml min(-1) kg(-1) compared with 6, 7 and 2 ml min(-1) kg(-1) in female rat, male monkey and male dogs, respectively). 4. The low amounts of M1 observed in male rats, with the appearance of products of the cleavage of the propyl group between the phenyl groups was probably due to the presence of the sex-specific CYP2C11, which cleaves P1 at the propyl bridge. None of the CYPs present in female rats cleaved P1 at this site and M1 was only produced by CYP2C6. In humans, only CYP2C8 and the polymorphic CYP2C19 produced M1.
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Affiliation(s)
- M Beconi
- Department of Drug Metabolim, Merck Research Laboratories, Rahway, NJ 07065, USA.
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Liu DQ, Hop CE, Beconi MG, Mao A, Chiu SH. Use of on-line hydrogen/deuterium exchange to facilitate metabolite identification. Rapid Commun Mass Spectrom 2001; 15:1832-1839. [PMID: 11565101 DOI: 10.1002/rcm.442] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Biotransformation studies performed on an investigational compound (I, represented by R1-CH(NH(2))-CO-N(R2)-CH(2)-S-R3) led to the identification of five metabolites (M1-M5). Based on LC/MS (liquid chromatography/mass spectrometry) analysis which included the use of H(2)O and D(2)O in the mobile phases, they were identified as the sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3), N-glucuronide (M4), and N-glucoside (M5) metabolites, respectively. The structure of M3, a less commonly seen carbamoyl glucuronide metabolite, was established using on-line H/D (hydrogen/deuterium) exchange experiments conducted by LC/MS. H/D exchange experiments were also used to distinguish the S-oxidation structures of M1 and M2 from hydroxylation. Herein, the application of deuterium oxide as the LC/MS mobile phase for structural elucidation of drug metabolites in biological matrices is demonstrated.
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Affiliation(s)
- D Q Liu
- Department of Drug Metabolism, Merck Research Laboratories, RY80L-109, P.O. Box 2000, Rahway, NJ 07065, USA.
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Sobolev NV, Fursenko BA, Goryainov SV, Shu J, Hemley RJ, Mao A, Boyd FR. Fossilized high pressure from the Earth's deep interior: the coesite-in-diamond barometer. Proc Natl Acad Sci U S A 2000; 97:11875-9. [PMID: 11035808 PMCID: PMC17262 DOI: 10.1073/pnas.220408697] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mineral inclusions in diamonds provide an important source of information about the composition of the continental lithosphere at depths exceeding 120-150 km, i.e., within the diamond stability field. Fossilized high pressures in coesite inclusions from a Venezuela diamond have been identified and measured by using laser Raman and synchrotron x-ray microanalytical techniques. Micro-Raman measurements on an intact inclusion of remnant vibrational band shifts give a high confining pressure of 3.62 (+/-0.18) GPa. Synchrotron single-crystal diffraction measurements of the volume compression are in accord with the Raman results and also revealed direct structural information on the state of the inclusion. In contrast to olivine and garnet inclusions, the thermoelasticity of coesite favors accurate identification of pressure preservation. Owing to the unique combination of physical properties of coesite and diamond, this "coesite-in-diamond" geobarometer is virtually independent of temperature, allowing an estimation of the initial pressure of Venezuela diamond formation of 5.5 (+/-0.5) GPa.
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Affiliation(s)
- N V Sobolev
- Institute of Mineralogy and Petrography, Russian Academy of Sciences Siberian Branch, Novosibirsk, 630090, Russia
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Abstract
We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa followed by a drastic increase in the conversion rate to our maximum pressure of 58 GPa. This pressure enhancement of conversion is not predicted by previous theoretical treatments and must be due to a new conversion pathway.
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Affiliation(s)
- J H Eggert
- Department of Physics, Colorado School of Mines, Golden, CO 80401, USA
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Abstract
Global Positioning System (GPS) measurements across the New Madrid seismic zone (NMSZ) in the central United States show little, if any, motion. These data are consistent with platewide continuous GPS data away from the NMSZ, which show no motion within uncertainties. Both these data and the frequency-magnitude relation for seismicity imply that had the largest shocks in the series of earthquakes that occurred in 1811 and 1812 been magnitude 8, their recurrence interval should well exceed 2500 years, longer than has been assumed. Alternatively, the largest 1811 and 1812 earthquakes and those in the paleoseismic record may have been much smaller than typically assumed. Hence, the hazard posed by great earthquakes in the NMSZ appears to be overestimated.
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Affiliation(s)
- A Newman
- Department of Geological Sciences, Northwestern University, Evanston, IL, 60208, USA. Department of Geology, Grand Valley State University, Allendale, MI 49401, USA. Department of Geological Sciences, University of Missouri, Columbia, MO
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Norabuena E, Leffler-Griffin L, Mao A, Dixon T, Stein S, Sacks IS, Ocola L, Ellis M. Space geodetic observations of nazca-south america convergence across the central andes. Science 1998; 279:358-62. [PMID: 9430582 DOI: 10.1126/science.279.5349.358] [Citation(s) in RCA: 203] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Space geodetic data recorded rates and directions of motion across the convergent boundary zone between the oceanic Nazca and continental South American plates in Peru and Bolivia. Roughly half of the overall convergence, about 30 to 40 millimeters per year, accumulated on the locked plate interface and can be released in future earthquakes. About 10 to 15 millimeters per year of crustal shortening occurred inland at the sub-Andean foreland fold and thrust belt, indicating that the Andes are continuing to build. Little (5 to 10 millimeters per year) along-trench motion of coastal forearc slivers was observed, despite the oblique convergence.
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Affiliation(s)
- E Norabuena
- E. Norabuena, Instituto Geofisico del Peru, Apartado 3747, Lima 100, Peru, and Rosenstiel School for Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA. L. Leffler-Griffin and S. Stein, Departme
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Abstract
The concentrations of endogenous ligands generally remain in a bounded range around a basal level, a manifestation of control. The dopaminergic system is an excellent example of a control system in which a negative feedback signal is associated with receptor occupancy of a D2-like dopamine autoreceptor. A consequence of the control theory is that autoreceptor occupancy by an agonist results in dopamine levels below the basal, whereas similar stimulation by a dopamine competitive antagonist results in an increase of dopamine to levels above the basal. These consequences of control theory were tested and verified in the rat striatum by infusing graded doses of either the agonist, quinpirole, or the antagonist, sulpiride, into the rat striatum via a microdialysis probe and sampling dopamine and metabolite levels at various times after the start of infusion. Control was maintained even at the very highest doses of these compounds, i.e., striatal dopamine concentration rose in response to the antagonist and fell in response to the agonist. In contrast, administration of each of two high affinity dopamine agonists, 7-OH-DPAT and PPHT showed dose-dependent control only up to certain doses. Above these doses the dopamine concentration actually increased to levels well above basal, an indication of loss of control. These findings suggest that the control of this endogenous ligand does not extend to the very highest levels of autoreceptor occupancy.
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Affiliation(s)
- A Mao
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Peng M, Emig FA, Mao A, Lu W, Kirby EP, Niewiarowski S, Kowalska MA. Interaction of echicetin with a high affinity thrombin binding site on platelet glycoprotein GPIb. Thromb Haemost 1995; 74:954-7. [PMID: 8571328] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Echicetin, a protein isolated from Echis carinatus snake venom, inhibited platelet aggregation and secretion induced by low concentrations of thrombin ( < 0.2 U/ml), by binding to platelet glycoprotein Ib (GPIb). The inhibition was not observed when the platelets were stimulated with higher concentrations of thrombin ( > 0.2 U/ml). Echicetin competed with thrombin for binding to the high affinity site on GPIb. Thrombin also inhibited 50% of the binding of 125I-echicetin to the platelets.
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Affiliation(s)
- M Peng
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Freeman KA, Mao A, Nordberg LO, Pak J, Tallarida RJ. The relationship between vessel wall tension and the magnitude and frequency of oscillation in rat aorta. Life Sci 1994; 56:PL129-34. [PMID: 7830497 DOI: 10.1016/0024-3205(94)00912-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Aortic rings from adult normotensive rats display spontaneous rhythmic activity that is enhanced by vasoconstricting agents. Graded doses of norepinephrine as well as combinations of norepinephrine and vasodilators produced levels of tension that were inversely related to the magnitude of oscillation and directly related to the frequency. A similar result occurred with KCl stimulation. Oscillations were only slightly affected by removal of the endothelium. These results, when combined with other reported studies, suggest that the oscillations in rat aorta are a manifestation of feedback control that may involve the cyclic release of one or more agents affecting calcium channels.
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Affiliation(s)
- K A Freeman
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140
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