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Ni N, Wang N, Veronese V, Wang MZ, Wang JW, Wang CH, Li T, Xia YY, Huang F, Zhao YL. Current status and future prospects of TB digital treatment adherence technology use in China. Int J Tuberc Lung Dis 2023; 27:438-443. [PMID: 37231604 DOI: 10.5588/ijtld.22.0540] [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] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND: Digital treatment adherence technologies (DATs) have been recommended by the Chinese National Tuberculosis Programme since 2015. However, until now the extent to which DATs have been adopted in China remain unclear. In this study, we aimed to understand the current status and future prospects of DAT use in China.METHODS: A cross-sectional study was undertaken to collect data from all 2,884 county-level TB-designated institutions across China using a quantitative questionnaire and extraction of information from the Chinese TB information management system. Data were collected between 1 July 2020 and 30 June 2021.RESULTS: All of the 2,884 county-level TB-designated institutions responded to the questionnaire. We found that the utilisation rate of DATs in China was 21.5% (n = 620). Among those using DATs, the uptake of DATs among TB patients was 31.0%. Lack of financial, policy and technology support were the main barriers to adoption and scale up DATs at the institution level.CONCLUSIONS: The use of DATs is in an early stage in China; however, the number of institutions who offer DATs have increased significantly after July 2020. To facilitate the use of DATs, the national TB programme should provide more financial, policy and technology support, and a national guideline is required.
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Affiliation(s)
- N Ni
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - N Wang
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - V Veronese
- The Special Programme for Research and Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - M-Z Wang
- Xinjiang Province Center Disease Control and Prevention, Urumchi, China
| | - J-W Wang
- Guangdong Tuberculosis Control Center, Guangzhou, China
| | - C-H Wang
- Tianjin Tuberculosis Control Center, Tianjin, China
| | - T Li
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Y-Y Xia
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - F Huang
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Y-L Zhao
- National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Frakulli R, Ni N, Schmidt L, Guntrum F, Kramer P, Frisch S, Glas M, Timmermann B. P03.09.A Proton beam therapy for adults medullobastoma. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Although Medulloblastoma (MB) is the most common primary malignant intracranial tumor in childhood, in adults it is extremely rare. Therefore, available data is scarce and experience with radiation and proton beam therapy (PBT) is very limited. The treatment typically includes tumour resection, irradiation of the craniospinal axis (CSI) followed by a boost, +/- concomitant chemotherapy, and maintenance therapy. Herein, we present our preliminary analysis of outcome and toxicity after PBT.
Material and Methods
Patients ≥ 18 years with primary MB treated with PBT between January 2017 and March 2020 enrolled in the prospective registry study (DRKS00004384) were evaluated in this analysis. Within the registry, adverse events were documented according to CTCAE v4.0 before, during, and after PT. The overall survival (OS), local control (LC) and higher-grade toxicity (≥ grade 3) were analyzed.
Results
A total of 19 patients (13 males, 6 females) with a median age of 23 years (range, 18.5- 39 years) were included in this study. Histopathology type were classic, desmoplastic /extensive nodularity or anaplastic MB in 52.6%, 26.3% and 21.1 % of patients, respectively. Complete tumor resection was performed in 57.8 % of patients. 68.4 % of patients had local disease without any metastases. Median total CSI dose was 35.2 Gy(RBE) (range, 23.4-40 Gy) with a median single dose of 1.6 Gy(RBE) (range, 1-1.8 Gy). All patients received either boost to the posterior fossa (57.9%) or to the tumor bed only (42.1%). The median total tumor dose was 18.8 Gy(RBE) (range, 54-68 Gy). Concomitant chemotherapy was given to 63.1% of patients. The median follow-up time after first diagnosis was 28.2 months (range, 8-56 months). No higher-grade acute or late adverse event was documented so far. One patient developed local disease progression. Another patient deceased due to an acute pulmonary embolism during maintenance chemotherapy without evidence of disease. The 3-year LC and OS rate were 89 % and 94 %, respectively.
Conclusion
Early results display good feasibility and high tumor control of PT in adult patient with MB. Results will need to be confirmed in larger cohort with longer follow-up time.<Bookmark(28)>
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Affiliation(s)
- R Frakulli
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
| | - N Ni
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
| | - L Schmidt
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
| | - F Guntrum
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
| | - P Kramer
- West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen , Essen , Germany
| | - S Frisch
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
| | - M Glas
- University Hospital Essen, University Duisburg-Essen, Division of Clinical Neuro-oncology, Department of Neurology/DKFZ Division of Translational Neuro-oncology , Essen , Germany
| | - B Timmermann
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) , Essen , Germany
- German Cancer Consortium (DKTK) , Essen , Germany
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Banerjee R, Pal P, Hilmi I, Ghoshal UC, Desai DC, Rahman MM, Dutta U, Mohiuddin SA, Al Mohannadi M, Philip M, Ramesh GN, Niriella MA, De Silva AP, de Silva HJ, Pisespongsa P, Limsrivilai J, Aniwan S, Nawarathne M, Fernandopulle N, Aye TT, Ni N, Al Awadhi S, Joshi N, Ngoc PTV, Kieu TV, Nguyen AD, Abdullah M, Ali E, Zeid A, Sollano JD, Saberi B, Omar M, Mohsin MN, Aftab H, Wai TM, Shastri YM, Chaudhuri S, Ahmed F, Bhatia SJ, Travis SPL. Emerging inflammatory bowel disease demographics, phenotype, and treatment in South Asia, South-East Asia, and Middle East: Preliminary findings from the Inflammatory Bowel Disease-Emerging Nations' Consortium. J Gastroenterol Hepatol 2022; 37:1004-1015. [PMID: 35178742 DOI: 10.1111/jgh.15801] [Citation(s) in RCA: 1] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 01/04/2022] [Accepted: 01/23/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Inflammatory bowel disease (IBD) is emerging in the newly industrialized countries of South Asia, South-East Asia, and the Middle East, yet epidemiological data are scarce. METHODS We performed a cross-sectional study of IBD demographics, disease phenotype, and treatment across 38 centers in 15 countries of South Asia, South-East Asia, and Middle East. Intergroup comparisons included gross national income (GNI) per capita. RESULTS Among 10 400 patients, ulcerative colitis (UC) was twice as common as Crohn's disease (CD), with a male predominance (UC 6678, CD 3495, IBD unclassified 227, and 58% male). Peak age of onset was in the third decade, with a low proportion of elderly-onset IBD (5% age > 60). Familial IBD was rare (5%). The extent of UC was predominantly distal (proctitis/left sided 67%), with most being treated with mesalamine (94%), steroids (54%), or immunomodulators (31%). Ileocolic CD (43%) was the commonest, with low rates of perianal disease (8%) and only 6% smokers. Diagnostic delay for CD was common (median 12 months; interquartile range 5-30). Treatment of CD included mesalamine, steroids, and immunomodulators (61%, 51%, and 56%, respectively), but a fifth received empirical antitubercular therapy. Treatment with biologics was uncommon (4% UC and 13% CD), which increased in countries with higher GNI per capita. Surgery rates were 0.1 (UC) and 2 (CD) per 100 patients per year. CONCLUSIONS The IBD-ENC cohort provides insight into IBD in South-East Asia and the Middle East, but is not yet population based. UC is twice as common as CD, familial disease is uncommon, and rates of surgery are low. Biologic use correlates with per capita GNI.
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Affiliation(s)
- Rupa Banerjee
- Department of Medical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
| | - Partha Pal
- Department of Medical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
| | - Ida Hilmi
- University of Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Uday C Ghoshal
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Devendra C Desai
- Department of Gastroenterology, P.D. Hinduja National Hospital and Medical Research Centre, Mumbai, India
| | | | - Usha Dutta
- Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Syed A Mohiuddin
- Division of Gastroenterology, Department of Medicine, Hamad General Hospital, Doha, Qatar
| | - Munnera Al Mohannadi
- Division of Gastroenterology, Department of Medicine, Hamad General Hospital, Doha, Qatar
| | - Mathew Philip
- Lisie Institute of Gastroenterology, Lisie Hospital, Kochi, India
| | | | - Madunil A Niriella
- Department of Medicine, Faculty of Medicine, University of Kelaniya, Colombo, Sri Lanka
| | - Arjuna P De Silva
- Department of Medicine, Faculty of Medicine, University of Kelaniya, Colombo, Sri Lanka
| | | | | | - Julajak Limsrivilai
- Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | | | | | - Than Than Aye
- Department of Gastroenterology, Thingangyun General Hospital, University of Medicine 2, Yangon, Myanmar
| | - Nwe Ni
- Department of Gastroenterology, Mandalay General Hospital and University of Medicine, Mandalay, Myanmar
| | - Sameer Al Awadhi
- Digestive Disease Unit, Rashid Hospital, Dubai, United Arab Emirates
| | | | | | | | | | - Murdani Abdullah
- Department of Internal Medicine, Cipto Mangunkusumo National Hospital, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Ezzat Ali
- Department of Internal Medicine, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Ahmed Zeid
- Department of Internal Medicine, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Jose D Sollano
- Department of Medicine, University of Santo Tomas, Manila, Philippines
| | | | | | - Mostafa Noor Mohsin
- Department of Gastroenterology, Chittagong Medical College, Chittagong, Bangladesh
| | - Hafeza Aftab
- Department of Gastroenterology, Dhaka Medical College and Hospital, Dhaka, Bangladesh
| | - Tin Moe Wai
- Department of Gastroenterology, Yangon General Hospital, University of Medicine (1), Yangon, Myanmar
| | - Yogesh M Shastri
- Department of Gastroenterology, NMC Specialty Hospital, Abu Dhabi, United Arab Emirates
| | | | - Faruque Ahmed
- Department of Gastroenterology, Dhaka Medical College and Hospital, Dhaka, Bangladesh
| | | | - Simon P L Travis
- Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford, UK
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Sirica N, Orth PP, Scheurer MS, Dai YM, Lee MC, Padmanabhan P, Mix LT, Teitelbaum SW, Trigo M, Zhao LX, Chen GF, Xu B, Yang R, Shen B, Hu C, Lee CC, Lin H, Cochran TA, Trugman SA, Zhu JX, Hasan MZ, Ni N, Qiu XG, Taylor AJ, Yarotski DA, Prasankumar RP. Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs. Nat Mater 2022; 21:62-66. [PMID: 34750539 DOI: 10.1038/s41563-021-01126-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.
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Affiliation(s)
- N Sirica
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - P P Orth
- Ames Laboratory, Ames, IA, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, USA
| | - M S Scheurer
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria
| | - Y M Dai
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - M-C Lee
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - P Padmanabhan
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - L T Mix
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - S W Teitelbaum
- Department of Physics, Arizona State Univeristy, Tempe, AZ, USA
- Beus CXFEL Labs, Biodesign Institute, Arizona State Univeristy, Tempe, AZ, USA
| | - M Trigo
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - L X Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - G F Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - B Xu
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - R Yang
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - B Shen
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Guangzhou, China
| | - C Hu
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - C-C Lee
- Department of Physics, Tamkang University, New Taipei, Taiwan
| | - H Lin
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - T A Cochran
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - S A Trugman
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - J-X Zhu
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - M Z Hasan
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - N Ni
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - X G Qiu
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - A J Taylor
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - D A Yarotski
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - R P Prasankumar
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA.
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5
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Sirica N, Tobey RI, Zhao LX, Chen GF, Xu B, Yang R, Shen B, Yarotski DA, Bowlan P, Trugman SA, Zhu JX, Dai YM, Azad AK, Ni N, Qiu XG, Taylor AJ, Prasankumar RP. Tracking Ultrafast Photocurrents in the Weyl Semimetal TaAs Using THz Emission Spectroscopy. Phys Rev Lett 2019; 122:197401. [PMID: 31144919 DOI: 10.1103/physrevlett.122.197401] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/05/2019] [Indexed: 06/09/2023]
Abstract
We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.
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Affiliation(s)
- N Sirica
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R I Tobey
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747AG, Netherlands
| | - L X Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - G F Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - B Xu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - R Yang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - B Shen
- Department of Physics and Astronomy and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095, USA
| | - D A Yarotski
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - P Bowlan
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S A Trugman
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J-X Zhu
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Y M Dai
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- School of Physics, Nanjing University, Nanjing 210093, China
| | - A K Azad
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095, USA
| | - X G Qiu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - A J Taylor
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R P Prasankumar
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Liu ZR, Zhang N, Ni N, Wu GG, Li JT, Dong L. [Advance of the HEART score in patients with chest pain at the emergency department]. Zhonghua Xin Xue Guan Bing Za Zhi 2019; 47:69-72. [PMID: 30669816 DOI: 10.3760/cma.j.issn.0253-3758.2019.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Z R Liu
- Department of Emergency, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
| | - N Zhang
- Cardiovascular Hospital, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
| | - N Ni
- Department of Surgery, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
| | - G G Wu
- Department of Surgery, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
| | - J T Li
- Department of Surgery, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
| | - L Dong
- Department of Emergency, General Hospital of Anshan Iron and Steel Group Corporation, Anshan 114021, China
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Ni N, Luo D. 1117 MiRNAs involved in ultraviolet radiation induced bystander effects. J Invest Dermatol 2018. [DOI: 10.1016/j.jid.2018.03.1131] [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: 10/17/2022]
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Luo D, Ni N. 1115 Long noncoding RNA associated-competing endogenous RNAs in UVB-induced premature senescence of human dermal fibroblasts. J Invest Dermatol 2018. [DOI: 10.1016/j.jid.2018.03.1129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ansari S, Kabamba ET, Shrestha PK, Aftab H, Myint T, Tshering L, Sharma RP, Ni N, Aye TT, Subsomwong P, Uchida T, Ratanachu-ek T, Vilaichone RK, Mahachai V, Matsumoto T, Akada J, Yamaoka Y. Helicobacter pylori bab characterization in clinical isolates from Bhutan, Myanmar, Nepal and Bangladesh. PLoS One 2017; 12:e0187225. [PMID: 29107979 PMCID: PMC5673166 DOI: 10.1371/journal.pone.0187225] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 10/16/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Helicobacter pylori BabA is an important outer membrane protein that involves in the attachment to the gastric mucosa and enhances the virulence property of the bacterium. This study was aimed to characterize the bab genotypes, to evaluate its association with cagA, vacA and clinical diseases as well as degree of gastric inflammation. METHODS H. pylori isolates from four countries were subjected for the characterization of bab. The locus specific forward and bab specific reverse primers were used to get the specific products by PCR, which could distinguish the three locus (A, B and C). The histological activities were evaluated according to the Updated Sydney system. RESULT In patients from high risk countries (Bhutan and Myanmar) relatively higher frequencies of strains with babA-positivity (91.8% and 90.7%, respectively), babA at locus A (98% and 91.2%, respectively) and with single babA (96.8% and 91.2%, respectively) were found. Strains with two loci occupied were the most prevalent in Bhutan (84.6%), Myanmar (74.7%), Nepal (58.3%) and Bangladesh (56.9%). The genotype babA at locus A/babB at locus B/bab-negative at locus C (babA/babB/-) was the most common genotype isolated from Bhutan (82.7%), Myanmar (58.7%), Nepal (32%) and Bangladesh (31.4%) among all genotypes assessed. This genotype was also associated with the peptic ulcer disease (P = 0.013) when compared to gastritis. babA-positive characteristics and the genotype babA/babB/- exhibited the enhanced histological activities. CONCLUSIONS The higher prevalence of virulence associated babA-positive characteristics and enhanced histological activities in Bhutan than in Myanmar, Nepal and Bangladesh might partly explain why the peoples in Bhutan are at higher risk for developing severe gastric complications.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | | | - Pradeep Krishna Shrestha
- Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Hafeza Aftab
- Department of Gastroenterology, Dhaka Medical College and Hospital, Dhaka, Bangladesh
| | - Thein Myint
- Department of Gastroenterology, Yangon General Hospital, Yangon, Myanmar
| | - Lotay Tshering
- Department of Surgery, Jigme Dorji Wangchuck National Referral Hospital, Thimphu, Bhutan
| | - Rabi Prakash Sharma
- Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Nwe Ni
- Department of Gastroenterology, Mandalay General Hospital and University of Medicine (Mandalay), Mandalay, Myanmar
| | - Than Than Aye
- Department of Gastroenterology, Thingangyun Sanpya General Hospital and University of Medicine (2), Thingangyun, Myanmar
| | - Phawinee Subsomwong
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Tomohisa Uchida
- Department of Molecular Pathology, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan
| | | | - Ratha-korn Vilaichone
- Gastroenterology Unit, Department of Medicine, Thammasat University Hospital, Pathum Thani, Thailand
| | | | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
- Department of Medicine-Gastroenterology, Baylor College of Medicine, Houston, TX, United States of America
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Ni N, Wang ZL. [Meeting Minutes of 2016 International Congress of Oral Implantology: Pujiang Forum]. Zhonghua Kou Qiang Yi Xue Za Zhi 2017; 52:53-54. [PMID: 28072996 DOI: 10.3760/cma.j.issn.1002-0098.2017.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- N Ni
- Office for Dean's Affairs, School & Hospital of Stomatology, Tongji University, Shanghai 200072, China
| | - Z L Wang
- Department of Oral Implantology, School & Hospital of Stomatology, Tongji University, Shanghai 200072, China
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Mounce AM, Yasuoka H, Koutroulakis G, Ni N, Bauer ED, Ronning F, Thompson JD. Detection of a spin-triplet superconducting phase in oriented polycrystalline U(2)PtC(2) samples using ^(195)Pt nuclear magnetic resonance. Phys Rev Lett 2015; 114:127001. [PMID: 25860768 DOI: 10.1103/physrevlett.114.127001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Indexed: 06/04/2023]
Abstract
Nuclear magnetic resonance (NMR) measurements on the ^{195}Pt nucleus in an aligned powder of the moderately heavy-fermion material U_{2}PtC_{2} are consistent with spin-triplet pairing in its superconducting state. Across the superconducting transition temperature and to much lower temperatures, the NMR Knight shift is temperature independent for field both parallel and perpendicular to the tetragonal c axis, expected for triplet equal-spin pairing superconductivity. The NMR spin-lattice relaxation rate 1/T_{1}, in the normal state, exhibits characteristics of ferromagnetic fluctuations, compatible with an enhanced Wilson ratio. In the superconducting state, 1/T_{1} follows a power law with temperature without a coherence peak giving additional support that U_{2}PtC_{2} is an unconventional superconductor. Bulk measurements of the ac susceptibility and resistivity indicate that the upper critical field exceeds the Pauli limiting field for spin-singlet pairing and is near the orbital limiting field, an additional indication for spin-triplet pairing.
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Affiliation(s)
- A M Mounce
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H Yasuoka
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - G Koutroulakis
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N Ni
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E D Bauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Ronning
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J D Thompson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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12
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Kim MG, Lamsal J, Heitmann TW, Tucker GS, Pratt DK, Khan SN, Lee YB, Alam A, Thaler A, Ni N, Ran S, Bud'ko SL, Marty KJ, Lumsden MD, Canfield PC, Harmon BN, Johnson DD, Kreyssig A, McQueeney RJ, Goldman AI. Effects of transition metal substitutions on the incommensurability and spin fluctuations in BaFe2As2 by elastic and inelastic neutron scattering. Phys Rev Lett 2012; 109:167003. [PMID: 23215117 DOI: 10.1103/physrevlett.109.167003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Indexed: 06/01/2023]
Abstract
The spin fluctuation spectra from nonsuperconducting Cu-substituted, and superconducting Co-substituted, BaFe(2)As(2) are compared quantitatively by inelastic neutron scattering measurements and are found to be indistinguishable. Whereas diffraction studies show the appearance of incommensurate spin-density wave order in Co and Ni substituted samples, the magnetic phase diagram for Cu substitution does not display incommensurate order, demonstrating that simple electron counting based on rigid-band concepts is invalid. These results, supported by theoretical calculations, suggest that substitutional impurity effects in the Fe plane play a significant role in controlling magnetism and the appearance of superconductivity, with Cu distinguished by enhanced impurity scattering and split-band behavior.
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Affiliation(s)
- M G Kim
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
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13
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McLeod JA, Buling A, Green RJ, Boyko TD, Skorikov NA, Kurmaev EZ, Neumann M, Finkelstein LD, Ni N, Thaler A, Bud'ko SL, Canfield PC, Moewes A. Effect of 3d doping on the electronic structure of BaFe2As2. J Phys Condens Matter 2012; 24:215501. [PMID: 22534111 DOI: 10.1088/0953-8984/24/21/215501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The electronic structure of BaFe(2)As(2) doped with Co, Ni and Cu has been studied by a variety of experimental and theoretical methods, but a clear picture of the dopant 3d states has not yet emerged. Herein we provide experimental evidence of the distribution of Co, Ni and Cu 3d states in the valence band. We conclude that the Co and Ni 3d states provide additional free carriers to the Fermi level, while the Cu 3d states are found at the bottom of the valence band in a localized 3d(10) shell. These findings help shed light on why superconductivity can occur in BaFe(2)As(2) doped with Co and Ni but not Cu.
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Affiliation(s)
- J A McLeod
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK, Canada.
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14
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Tanatar MA, Reid JP, Shakeripour H, Luo XG, Doiron-Leyraud N, Ni N, Bud'ko SL, Canfield PC, Prozorov R, Taillefer L. Doping dependence of heat transport in the iron-arsenide superconductor Ba(Fe(1-x)Co(x))2As2: from isotropic to a strongly k-dependent gap structure. Phys Rev Lett 2010; 104:067002. [PMID: 20366850 DOI: 10.1103/physrevlett.104.067002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 12/18/2009] [Indexed: 05/29/2023]
Abstract
The temperature and magnetic field dependence of the in-plane thermal conductivity kappa of the iron-arsenide superconductor Ba(Fe(1-x)Co(x))2As2 was measured down to T approximately 50 mK and up to H = 15 T as a function of Co concentration x in the range 0.048 < or = x < or = 0.114. At H = 0, a negligible residual linear term in kappa/T as T-->0 at all x shows that the superconducting gap has no nodes in the ab plane anywhere in the phase diagram. However, while the slow H dependence of kappa(H) at T-->0 in the underdoped regime is consistent with a superconducting gap that is large everywhere on the Fermi surface, the rapid increase in kappa(H) observed in the overdoped regime shows that the gap acquires a deep minimum somewhere on the Fermi surface. Outside the antiferromagnetic-orthorhombic phase, the superconducting gap structure has a strongly k-dependent amplitude.
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15
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Nandi S, Kim MG, Kreyssig A, Fernandes RM, Pratt DK, Thaler A, Ni N, Bud'ko SL, Canfield PC, Schmalian J, McQueeney RJ, Goldman AI. Anomalous suppression of the orthorhombic lattice distortion in superconducting Ba(Fe1-xCox)2As2 single crystals. Phys Rev Lett 2010; 104:057006. [PMID: 20366790 DOI: 10.1103/physrevlett.104.057006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Indexed: 05/29/2023]
Abstract
High-resolution x-ray diffraction measurements reveal an unusually strong response of the lattice to superconductivity in Ba(Fe1-xCox)2As2. The orthorhombic distortion of the lattice is suppressed and, for Co doping near x=0.063, the orthorhombic structure evolves smoothly back to a tetragonal structure. We propose that the coupling between orthorhombicity and superconductivity is indirect and arises due to the magnetoelastic coupling, in the form of emergent nematic order, and the strong competition between magnetism and superconductivity.
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Affiliation(s)
- S Nandi
- Ames Laboratory, U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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16
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Pratt DK, Tian W, Kreyssig A, Zarestky JL, Nandi S, Ni N, Bud'ko SL, Canfield PC, Goldman AI, McQueeney RJ. Coexistence of competing antiferromagnetic and superconducting phases in the underdoped Ba(Fe0.953Co0.047)2As2 compound using x-ray and neutron scattering techniques. Phys Rev Lett 2009; 103:087001. [PMID: 19792748 DOI: 10.1103/physrevlett.103.087001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Indexed: 05/28/2023]
Abstract
Neutron and x-ray diffraction studies show that the simultaneous first-order transition to an orthorhombic and antiferromagnetic (AFM) ordered state in BaFe2As2 splits into two transitions with Co doping. For Ba(Fe0.953Co0.047)2As2, a tetragonal-orthorhombic transition occurs at TS=60 K, followed by a second-order transition to AFM order at TN=47 K. Superconductivity occurs in the orthorhombic state below TC=17 K and coexists with AFM. Below TC, the static Fe moment is reduced along with a redistribution of low energy magnetic excitations indicating competition between coexisting superconductivity and AFM order.
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Affiliation(s)
- D K Pratt
- Department of Physics and Astronomy and Ames Laboratory, Iowa State University, Ames, Iowa 50011 USA
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17
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Yang J, Hüvonen D, Nagel U, Rõõm T, Ni N, Canfield PC, Bud'ko SL, Carbotte JP, Timusk T. Optical spectroscopy of superconducting Ba0.55K0.45Fe2As2: evidence for strong coupling to low-energy bosons. Phys Rev Lett 2009; 102:187003. [PMID: 19518902 DOI: 10.1103/physrevlett.102.187003] [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: 07/07/2008] [Indexed: 05/27/2023]
Abstract
Normal state optical spectroscopy on single crystals of the new iron arsenide superconductor Ba0.55K0.45Fe2As2 shows that the infrared spectrum consists of two major components: a strong metallic Drude band and a well-separated midinfrared absorption centered at 0.7 eV. It is difficult to separate the two components unambiguously but several fits using Lorentzian peaks suggest a model with a Drude peak having a plasma frequency of 1.6 to 2.1 eV and a midinfrared peak with a plasma frequency of 2.5 eV. Detailed analysis of the frequency dependent scattering rate shows that the charge carriers interact with a broad bosonic spectrum extending beyond 100 meV with a very large coupling constant lambda=3.4 at low temperature. As the temperature increases this coupling weakens to lambda=0.78 at ambient temperature. This suggests a bosonic spectrum that is similar to what is seen in the lower Tc cuprates.
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Affiliation(s)
- J Yang
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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18
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Diallo SO, Antropov VP, Perring TG, Broholm C, Pulikkotil JJ, Ni N, Bud'ko SL, Canfield PC, Kreyssig A, Goldman AI, McQueeney RJ. Itinerant magnetic excitations in antiferromagnetic CaFe2As2. Phys Rev Lett 2009; 102:187206. [PMID: 19518910 DOI: 10.1103/physrevlett.102.187206] [Citation(s) in RCA: 7] [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: 01/27/2009] [Indexed: 05/27/2023]
Abstract
Neutron scattering measurements of the magnetic excitations in single crystals of antiferromagnetic CaFe2As2 reveal steeply dispersive and well-defined spin waves up to an energy of approximately 100 meV. Magnetic excitations above 100 meV and up to the maximum energy of 200 meV are however broader in energy and momentum than the experimental resolution. While the low energy modes can be fit to a Heisenberg model, the total spectrum cannot be described as arising from excitations of a local moment system. Ab initio calculations of the dynamic magnetic susceptibility suggest that the high energy behavior is dominated by the damping of spin waves by particle-hole excitations.
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Affiliation(s)
- S O Diallo
- Ames Laboratory USDOE, Ames, Iowa 50011 USA
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19
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Gordon RT, Ni N, Martin C, Tanatar MA, Vannette MD, Kim H, Samolyuk GD, Schmalian J, Nandi S, Kreyssig A, Goldman AI, Yan JQ, Bud'ko SL, Canfield PC, Prozorov R. Unconventional London penetration depth in single-crystal Ba(Fe0.93Co0.07)2As2 superconductors. Phys Rev Lett 2009; 102:127004. [PMID: 19392314 DOI: 10.1103/physrevlett.102.127004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Indexed: 05/27/2023]
Abstract
The London penetration depth lambda(T) has been measured in single crystals of Ba(Fe0.93Co0.07)2As2. The observed low-temperature variation of lambda(T) follows a power law, Deltalambda(T) approximately T(n) with n approximately 2.4+/-0.1, indicating the existence of normal quasiparticles down to at least 0.02T(c). This is in contrast with previous penetration depth measurements on single crystals of NdFeAsO1-xFx and SmFeAsO1-xFx, which indicate an anisotropic but nodeless gap. We discuss possible explanations of the observed power law behavior.
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Affiliation(s)
- R T Gordon
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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20
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Ni N, Mojibian H, Pollak J, Tal M. Abstract No. 88: Outcomes of Fibrin Sheath Stripping Versus Catheter Exchange of Malfunctioning Tunneled Hemodialysis Catheters. J Vasc Interv Radiol 2009. [DOI: 10.1016/j.jvir.2008.12.078] [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: 10/21/2022] Open
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21
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McQueeney RJ, Diallo SO, Antropov VP, Samolyuk GD, Broholm C, Ni N, Nandi S, Yethiraj M, Zarestky JL, Pulikkotil JJ, Kreyssig A, Lumsden MD, Harmon BN, Canfield PC, Goldman AI. Anisotropic three-dimensional magnetism in CaFe2As2. Phys Rev Lett 2008; 101:227205. [PMID: 19113520 DOI: 10.1103/physrevlett.101.227205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Indexed: 05/27/2023]
Abstract
Inelastic neutron scattering measurements of the magnetic excitations in CaFe2As2 indicate that the spin wave velocity in the Fe layers is exceptionally large and similar in magnitude to the cuprates. However, the spin wave velocity perpendicular to the layers is at least half as large that in the layer, so that the magnetism is more appropriately categorized as anisotropic three-dimensional, in contrast to the two-dimensional cuprates. Exchange constants derived from band structure calculations predict spin wave velocities that are consistent with the experimental data.
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Affiliation(s)
- R J McQueeney
- Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, USA
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Affiliation(s)
- T Sanghvi
- College of Pharmacy, Tucson, Arizona 85721, USA.
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Abstract
1-(2-Chloroethyl)-3-sarcosinamide-1-nitrosourea, (SarCNU) (NSC-364432) is a new antitumor drug that is of interest to the National Cancer Institute. It is intended for use as an intravenous injection. Although SarCNU is sufficiently soluble in water to obtain the desired dosage, it is highly unstable. Its T(90) in aqueous solution at room temperature is less than 6 h. Neat tertiary butyl alcohol (TBA), a low toxicity, high vapor pressure and low melting solvent, was determined to be an excellent freeze-drying medium. Lyophilization of SarCNU from pure TBA produces a uniform cake composed of needle-shaped crystals. Thermal analysis and gas chromatography indicate that the cake contains less than 0.001% residual solvent. The SarCNU cake can be readily reconstituted with either water or an aqueous solution of 40% propylene glycol and 10% ethanol. The reconstituted solutions are stable for 4 and 13 h, respectively.
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Affiliation(s)
- N Ni
- College of Pharmacy, University of Arizona, Tucson, AZ 85721, USA.
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24
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Abstract
The Setschenow constant, K(salt), of a nonelectrolyte in a NaCl solution is shown to be related to the logarithm of its octanol-water partition coefficient, log K(ow), determined by K(salt) = A log K(ow) + B, where K(ow) is the octanol-water partition coefficient of the solute and the coefficients A and B are constants. The values of A and B were empirically determined from literature data for 62 organic compounds and validated for a test set of 15 compounds including several drugs.
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Affiliation(s)
- N Ni
- College of Pharmacy, The University of Arizona, Tucson, Arizona 85721, USA
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25
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Abstract
The synthetic estrogens ethinyl estradiol (EE) and mestranol (M) are weak complete hepatic carcinogens and potent tumor promoters. In vivo, EE and M cause a rapid but transient increase in liver growth. However, studies in cultured female rat hepatocytes indicate that EE is not a strong complete hepatic mitogen but rather enhances epidermal growth factor (EGF)-induced DNA synthesis and is thus classified as a co-mitogen (Yager, J.D., Zurlo, J. and Ni, N. (1991) Proc. Soc. Exptl. Biol. Med., 198, 667-674). The endogenous estrogen 17 beta-estradiol (E2) also exhibits co-mitogenic activity, enhancing the fraction of hepatocytes undergoing DNA synthesis induced by both EGF and transforming growth factor alpha (TGF-alpha) (Ni, N. and Yager, J.D. (1994) Hepatology, 19, 183-192). The objectives of the study reported here were: (1) to determine whether the co-mitogenic effects of EE and E2 extend to other synthetic estrogens including mestranol and diethylstilbestrol, and to alpha-zearalanol, a natural product with estrogenic activity; (2) to compare the co-mitogenic effects of endogenous estrogens including E2, estrone, estriol and the catechol metabolites 2- and 4-hydroxy-estradiol; and (3) to determine whether the conditioned medium from E2-treated hepatocytes has co-mitogenic activity. Female rat hepatocytes in primary culture were exposed to the various estrogens +/- TGF-alpha and DNA synthesis was determined by measuring [3H]thymidine incorporation into extracted DNA. The results show that the co-mitogenic effects previously observed with EE and E2 also extend to all of these estrogens and to the E2 catechol metabolites. Although the co-mitogenic potency of these estrogens does not correlate with their reported affinities to the estrogen receptor, their estrogenicity appears necessary since the non-estrogenic metabolite 2-methoxy-estradiol lacks co-mitogenic activity. In addition, enhancement of TGF-alpha-induced DNA synthesis by conditioned medium from E2-treated cells supports the notion that a metabolite mediates its co-mitogenic effect.
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Affiliation(s)
- N Ni
- Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205
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27
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Ni N, Yager JD. Comitogenic effects of estrogens on DNA synthesis induced by various growth factors in cultured female rat hepatocytes. Hepatology 1994; 19:183-92. [PMID: 7506224] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Ethinyl estradiol is a weak complete carcinogen and potent tumor promoter. In vivo, ethinyl estradiol causes a rapid but transient increase in liver growth, whereas in cultured female hepatocytes it enhances DNA synthesis induced by epidermal growth factor and is thus classified as a comitogen. The objectives of this study were to determine: (a) whether estradiol also has comitogenic activity; (b) whether the comitogenic effects of estrogen extend to complete hepatic mitogens other than epidermal growth factor and (c) whether inhibition of hepatocyte DNA synthesis by transforming growth factor-beta can be blocked by estradiol. Female rat hepatocytes in primary culture were exposed to estradiol with and without various growth factors, and we determined DNA synthesis by measuring [3H]thymidine incorporation into extracted DNA or by determining the nuclear labeling index by means of autoradiography. The results show that estradiol, like ethinyl estradiol, has comitogenic activity for epidermal growth factor, although it is somewhat less potent. Four complete hepatic mitogens showed different abilities to stimulate DNA synthesis, with hepatocyte growth factor > transforming growth factor-alpha > epidermal growth factor > acidic fibroblast growth factor. Estradiol enhanced DNA synthesis occurring in response to all four of these complete hepatic mitogens. This finding suggests that the mechanism of estrogen comitogenesis may involve effects at a point where the different signal-transduction pathways leading from the growth factors converge. The level of estrogen-mediated enhancement of DNA synthesis was similar for all four mitogens, ranging from 1.5 to 2.2-fold, depending on the experiment. Furthermore, determination of the nuclear labeling index showed that estrogen enhancement of DNA synthesis was associated with an increase in the percentage of hepatocytes that responded to the growth factors. Finally, estradiol did not specifically block the growth-inhibitory effects of transforming growth factor-beta.
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Affiliation(s)
- N Ni
- Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland 21205
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28
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Abstract
Epidemiological and experimental data strongly support a causal relationship between exposure to excessive levels of estrogens and the development of cancer in various tissues. In this paper, we have presented background information that shows a correlation between the prolonged use of oral contraceptives and the development of liver cancer. The clinical data supported the hypothesis that the estrogenic components of oral contraceptives were promoters of hepatocarcinogenesis, and the experimental evidence in support of this hypothesis and bearing on the mechanisms involved are also reviewed. The effects of estrogens on liver neoplasia and growth are: (i) synthetic steroidal estrogens are potent promoters of hepatocarcinogenesis in female rats; (ii) these estrogens stimulate liver growth at doses that are not hepatotoxic; (iii) the mechanisms by which the estrogens stimulate liver growth are indirect and include the enhancement of a serum/plasma growth factor, co-mitogenic effects which result in enhanced responsiveness of cultured hepatocytes to epidermal growth factor and decreased sensitivity of hepatocytes to growth inhibition by transforming growth factor-beta; (iv) the co-mitogenic effects of synthetic estrogens extend to endogenous estrogens and natural product estrogens; and (v) the co-mitogenic effects of estrogens for epidermal growth factor are associated with increased epidermal growth factor receptor protein levels caused by an increase in the half-life of the receptor protein. The synthetic estrogens also have weak "complete" carcinogenic activity in rat liver and strong complete carcinogenic activity in Syrian hamster kidney and Armenian hamster liver. Evidence from the literature is presented in support of a hypothesis that this process may involve indirect genotoxicity mediated through redox cycling and the formation of hydroxylated DNA bases. This process, together with the potent promoting activity of these estrogenic chemicals, may account for their complete carcinogenicity.
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Affiliation(s)
- J D Yager
- Department of Environmental Health Sciences, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205
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