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Shcherbakov D, Voigt G, Memaran S, Liu GB, Wang Q, Watanabe K, Taniguchi T, Smirnov D, Balicas L, Zhang F, Lau CN. Giant Tunability of Intersubband Transitions and Quantum Hall Quartets in Few-Layer InSe Quantum Wells. Nano Lett 2024; 24:3851-3857. [PMID: 38502010 DOI: 10.1021/acs.nanolett.3c04121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
A two-dimensional (2D) quantum electron system is characterized by quantized energy levels, or subbands, in the out-of-plane direction. Populating higher subbands and controlling the intersubband transitions have wide technological applications such as optical modulators and quantum cascade lasers. In conventional materials, however, the tunability of intersubband spacing is limited. Here we demonstrate electrostatic population and characterization of the second subband in few-layer InSe quantum wells, with giant tunability of its energy, population, and spin-orbit coupling strength, via the control of not only layer thickness but also the out-of-plane displacement field. A modulation of as much as 350% or over 250 meV is achievable, underscoring the promise of InSe for tunable infrared and THz sources, detectors, and modulators.
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Affiliation(s)
- Dmitry Shcherbakov
- Department of Physics, The Ohio State University, Columbus, Ohio 43221, United States
| | - Greyson Voigt
- Department of Physics, The Ohio State University, Columbus, Ohio 43221, United States
| | - Shahriar Memaran
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Gui-Bin Liu
- School of Physics, Beijing Institute of Technology, 100081 Beijing, China
| | - Qiyue Wang
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, United States
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Luis Balicas
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Fan Zhang
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, United States
| | - Chun Ning Lau
- Department of Physics, The Ohio State University, Columbus, Ohio 43221, United States
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2
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Zhou J, Zhu C, Zhou Y, Dong J, Li P, Zhang Z, Wang Z, Lin YC, Shi J, Zhang R, Zheng Y, Yu H, Tang B, Liu F, Wang L, Liu L, Liu GB, Hu W, Gao Y, Yang H, Gao W, Lu L, Wang Y, Suenaga K, Liu G, Ding F, Yao Y, Liu Z. Composition and phase engineering of metal chalcogenides and phosphorous chalcogenides. Nat Mater 2023; 22:450-458. [PMID: 35739274 DOI: 10.1038/s41563-022-01291-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) materials with multiphase, multielement crystals such as transition metal chalcogenides (TMCs) (based on V, Cr, Mn, Fe, Cd, Pt and Pd) and transition metal phosphorous chalcogenides (TMPCs) offer a unique platform to explore novel physical phenomena. However, the synthesis of a single-phase/single-composition crystal of these 2D materials via chemical vapour deposition is still challenging. Here we unravel a competitive-chemical-reaction-based growth mechanism to manipulate the nucleation and growth rate. Based on the growth mechanism, 67 types of TMCs and TMPCs with a defined phase, controllable structure and tunable component can be realized. The ferromagnetism and superconductivity in FeXy can be tuned by the y value, such as superconductivity observed in FeX and ferromagnetism in FeS2 monolayers, demonstrating the high quality of as-grown 2D materials. This work paves the way for the multidisciplinary exploration of 2D TMPCs and TMCs with unique properties.
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Affiliation(s)
- Jiadong Zhou
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China.
- Chongqing Center for Microelectronics and Microsystems, Beijing Institute of Technology, Chongqing, People's Republic of China.
| | - Chao Zhu
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing, People's Republic of China
| | - Yao Zhou
- Advanced Research Institute of Multidisciplinary Science, and School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, People's Republic of China
| | - Jichen Dong
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan, Republic of Korea
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Zhaowei Zhang
- School of Physical and Mathematical Science, Nanyang Technological University, Singapore, Singapore
| | - Zhen Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | - Yung-Chang Lin
- The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Jia Shi
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Runwu Zhang
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China
| | - Yanzhen Zheng
- Beijing Key Laboratory of Green Recovery and Extraction of Rare and Precious Metals, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Huimei Yu
- School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Bijun Tang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Fucai Liu
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Lin Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, People's Republic of China
| | - Liwei Liu
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, People's Republic of China
| | - Gui-Bin Liu
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China
| | - Weida Hu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | - Yanfeng Gao
- School of Materials Science and Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Haitao Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Weibo Gao
- School of Physical and Mathematical Science, Nanyang Technological University, Singapore, Singapore
| | - Li Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
- Songshan Lake Materials Laboratory, Guangdong, China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, People's Republic of China.
| | - Kazu Suenaga
- The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
- Songshan Lake Materials Laboratory, Guangdong, China
| | - Feng Ding
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Yugui Yao
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China.
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.
- CINTRA CNRS/NTU/THALES, Research Techno Plaza, Singapore, Singapore.
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
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3
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Liu GB, Zhang XB, Yuan L, Zhai XW, Zhou WH, Zeng M, Huang GY. [Strengthening the treatment of SARS-CoV-2 infection in children with underlying diseases]. Zhonghua Er Ke Za Zhi 2022; 60:1100-1102. [PMID: 36319140 DOI: 10.3760/cma.j.cn112140-20220705-00620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- G B Liu
- Department of Medical Affairs,Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X B Zhang
- Department of Respiratory Medicine,Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - L Yuan
- President Office, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X W Zhai
- Department of Hematology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - W H Zhou
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - M Zeng
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - G Y Huang
- Heart Center, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
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Li SJ, Zhang L, Yuan H, Zhang XB, Wang CQ, Liu GB, Gu Y, Yang TL, Zhu XT, Zhai XW, Shi Y, Jiang SY, Zhang K, Yan K, Zhang P, Hu XJ, Liu Q, Gao RW, Zhao J, Zhou JG, Cao Y, Li ZH. [Management and short-term outcomes of neonates born to mothers infected with SARS-CoV-2 Omicron variant]. Zhonghua Er Ke Za Zhi 2022; 60:1163-1167. [PMID: 36319151 DOI: 10.3760/cma.j.cn112140-20220613-00545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Objective: To summarize the management and short-term outcomes of neonates delivered by mothers infected with SARS-CoV-2 Omicron variant. Methods: A retrospective study was performed on 158 neonates born to mothers infected with SARS-CoV-2 Omicron variant admitted to the isolation ward of Children's Hospital of Fudan University from March 15th, 2022 to May 30th, 2022. The postnatal infection control measures for these neonates, and their clinical characteristics and short-term outcomes were analyzed. They were divided into maternal symptomatic group and maternal asymptomatic group according to whether their mothers had SARS-CoV-2 symptoms. The clinical outcomes were compared between the 2 groups using Rank sum test and Chi-square test. Results: All neonates were under strict infection control measures at birth and after birth. Of the 158 neonates, 75 (47.5%) were male. The gestational age was (38+3±1+3) weeks and the birth weight was (3 201±463)g. Of the neonates included, ten were preterm (6.3%) and the minimum gestational age was 30+1 weeks. Six neonates (3.8%) had respiratory difficulty and 4 of them were premature and required mechanical ventilation. All 158 neonates were tested negative for SARS-COV-2 nucleic acid by daily nasal swabs for the first 7 days. A total of 156 mothers (2 cases of twin pregnancy) infected with SARS-CoV-2 Omicron variant, the time from confirmed SARS-CoV-2 infection to delivery was 7 (3, 12) days. Among them, 88 cases (56.4%) showed clinical symptoms, but none needed intensive care treatment. The peripheral white blood cell count of the neonates in maternal symptomatic group was significantly higher than that in maternal symptomatic group (23.0 (18.7, 28.0) × 109 vs. 19.6 (15.4, 36.6) × 109/L, Z=2.44, P<0.05). Conclusions: Neonates of mothers infected with SARS-CoV-2 Omicron variant during third trimester have benign short-term outcomes, without intrauterine infection through vertical transmission. Strict infection control measures at birth and after birth can effectively protect these neonates from SARS-CoV-2 infection.
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Affiliation(s)
- S J Li
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - L Zhang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - H Yuan
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X B Zhang
- Department of Respiratory Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - C Q Wang
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - G B Liu
- Department of Medical Affairs, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Y Gu
- Department of Nursing, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - T L Yang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X T Zhu
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X W Zhai
- Department of Hematology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Y Shi
- Department of Rheumatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - S Y Jiang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - K Zhang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - K Yan
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - P Zhang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X J Hu
- Department of Nursing, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Q Liu
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - R W Gao
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - J Zhao
- Department of Neonatology, Shanghai Public Health Clinical Center, Shanghai 201508, China
| | - J G Zhou
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Y Cao
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Z H Li
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
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5
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Li JJ, Zeng M, Xu J, Ge YL, Tian H, Wang ZL, Liu GB, Zhai XW, Zhang XB, Zhu QR, Chang HL. [Diagnostic value of rapid antigen testing for the detection of SARS-CoV-2 infection]. Zhonghua Er Ke Za Zhi 2022; 60:1153-1157. [PMID: 36319149 DOI: 10.3760/cma.j.cn112140-20220628-00598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Objective: To investigate the diagnostic value of rapid antigen test based on colloidal gold immunochromatographic assay for the detection of SARS-CoV-2 infection in symptomatic patients. Methods: From May 20 to June 5 2022, 76 hospitalized children and their 55 accompanying family members with confirmed SARS-CoV-2 infection in the COVID-19 isolation unit of the Children's Hospital of Fudan University (designated referral hospital for SARS-CoV-2 infection in Shanghai) enrolled. Their nasopharyngeal swab specimens were consecutively collected. The samples were tested for SARS-CoV-2 nucleic acid by real-time quantitative. SARS-CoV-2 antigen was tested by immunochromatography. The correlation between the antigen detection results and the change of the cycle threshold (Ct) values were evaluated, as well as the sensitivity and specificity of SARS-CoV-2 antigen detection at different periods after the onset of the disease. Kappa consistency test was conducted to investigate the consistency between the 2 diagnostic methods. Results: Of the enrolled SARS-CoV-2 symptomatic infections, 76 were children, including 41 males and 35 females, with an age of 5 (2, 9) years; 55 were accompanying families, including 8 males and 47 females, with an age of 38 (32, 41) years. All 478 samples were simultaneously tested for SARS-CoV-2 antigen and nucleic acid. In any period from disease onset to negative conversion of viral nucleic acid, the overall sensitivity of the rapid antigen test was 48.2% (119/247), the specificity was 98.3% (227/231), and antigen test and nucleic acid test showed moderate consistency (κ=0.46, P<0.05). The sensitivity of antigen test was 100% (82/82) when the Ct value was ≤25. And the sensitivity of antigen test was 8/10, 4/15 and 8.3% (3/36) when the Ct value was 26, 30 and 35, respectively. All antigen tests were negative when Ct value was >35. During the period of 1-2 days, 3-5 days, 6-7 days, 8-10 days and >10 days after onset, the sensitivity and specificity of SARS-CoV-2 antigen test were 5/8 and 5/5, 90.2% (37/41) and 5/5, 88.9% (24/27) and 2/5, 45.0% (36/80) and 94.1% (32/34), 18.7% (17/91) and 98.9% (183/185) respectively. The Ct values of nasopharyngeal swabs were<26 during 2 to 7 days after onset, 28.7±5.0 on day 8, 34.5±2.9 on day 13 and > 35 after 14 days, respectively. Conclusion: SARS-CoV-2 antigen test in the patients with SARS-CoV-2 infection shows acceptable sensitivity and specificity within 7 days after onset of disease, and the sensitivity was positively correlated with viral load and negatively correlated with onset time.
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Affiliation(s)
- J J Li
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - M Zeng
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - J Xu
- Department of Clinical Laboratory, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Y L Ge
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - H Tian
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Z L Wang
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - G B Liu
- Department of Medical Affairs, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X W Zhai
- Department of Hematology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - X B Zhang
- Department of Respiratory Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - Q R Zhu
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - H L Chang
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
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Gu Y, Liu GB, Wang YW, Wang CQ, Zeng M, Lu GP, Wang ZL, Xia AM, Tao JH, Zhai XW, Zhou WH, Huang GY, Xu H, Gui YH, Zhang XB. [Management strategy and practice for SARS-CoV-2 infection in children's hospital]. Zhonghua Er Ke Za Zhi 2022; 60:1107-1110. [PMID: 36319142 DOI: 10.3760/cma.j.cn112140-20220607-00521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Y Gu
- Department of Nursing, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - G B Liu
- Department of Medical Affairs, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - Y W Wang
- Department of Nursing, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - C Q Wang
- Department of Nosocomial Infection Control, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - M Zeng
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - G P Lu
- Pediatric Intensive Care Unit, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - Z L Wang
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - A M Xia
- Department of Infectious Diseases, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
| | - J H Tao
- Pediatric Intensive Care Unit, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - X W Zhai
- Department of Hematology, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - W H Zhou
- Department of Neonatology, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - G Y Huang
- Heart Center, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - H Xu
- Department of Nephrology, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - Y H Gui
- Heart Center, Children's Hospital of Fudan University,National Children's Medical Center, Shanghai 201102, China
| | - X B Zhang
- Department of Respiratory Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai 201102, China
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Peng H, Wang F, Li JJ, Li JF, Shen XL, Liu GB, Pan XH, Hou CT, Yi WD, Wang Q. [Mechanical analysis of the impact of the morphology of the iris and ciliary body on the central vault after posterior chamber phakic intraocular lens implantation]. Zhonghua Yan Ke Za Zhi 2022; 58:615-623. [PMID: 35959606 DOI: 10.3760/cma.j.cn112142-20220214-00060] [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] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Objective: To investigate the impact of the iris and ciliary body morphology on the central vault after phakic posterior chamber intraocular lens (pIOL) implantation. Methods: This research was based on the retrospective analysis of 123 patients (123 eyes) who underwent pIOL implantation in the Department of Ophthalmology, Affiliated Hospital of Qingdao University between June 2018 and June 2020. The anterior segment structure was observed with an ultrasound biomicroscope before surgery, and all morphological parameters of the iris and ciliary body were measured manually using the ImageJ software, including iris span (IS), iris convexity (IC), iris-ciliary body contact distance (ICCD) and iris-lens contact distance (ILCD). The ICCD was divided into Q1, Q2 and Q3 groups according to the equidistant distance of 0.36 mm. The lens thickness was measured with the IOLMaster. The horizontal corneal diameter and anterior chamber depth were measured using the Pentacam. The central vaults were measured by optical coherence tomography at 1 week, 3 months and 1 year after surgery. The relationships between vault values and preoperative parameters of the anterior segment were evaluated using the Pearson correlation analysis, Spearman correlation analysis, and multiple linear regression. The repeated measures ANOVA was applied to identify changes of vault values over time. Results: The mean values of the vaults at 1 week, 3 months and 1 year after surgery were (723±265) μm, (642±255) μm and (613±280) μm, respectively. The difference among them was statistically significant (F=50.143, P<0.001). The vaults continued to decline within 1 year after pIOL implantation, and the total decline was (122±86) μm. The vaults declined by (69±98) μm from postoperative 1 week to 3 months and by (52±54) μm from postoperative 3 months to 1 year. The regression formula showed that the pIOL size and ILCD were positively related with the vault, while the LT, IS and IC were negatively related with the vault at 1 week postoperatively (adjusted R²=0.404, P<0.001). The pIOL size and ILCD were positively related with the vault, while the IS and IC were negatively related with the vault at 3 months postoperatively (adjusted R²=0.342, P<0.001). The pIOL size was positively related with the vault, while the IS and IC were negatively related with the vault at 1 year postoperatively (adjusted R²=0.661, P<0.001). The vault values were higher in group Q3 compared to group Q1 at every timepoint, and the vault value was higher in group Q2 compared to Q1 at 1 year postoperatively. Conclusions: In the early postoperative period, eyes with a larger pIOL, shorter iris span, longer contact distance between the iris and ciliary body, and longer contact distance between the iris and lens were associated with a higher rate of excessive vaults. Meanwhile, eyes with a thicker lens and larger iris reverse convexity were more likely to obtain insufficient vaults. Within one year after surgery, the pIOL size, IS, IC and ICCD continued to impact on the vault. The ICCD, ILCD and IC can reflect the posterior chamber volume and change the haptic location and force, thus affecting the vault.
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Affiliation(s)
- H Peng
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - F Wang
- Department of Ophthalmology, Weihai Municipal Hospital, Weihai 264200, China
| | - J J Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - J F Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - X L Shen
- College of Public Health, Qingdao University, Qingdao 266071, China
| | - G B Liu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - X H Pan
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - C T Hou
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - W D Yi
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Q Wang
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
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Cui H, Zhang KC, Cao B, Deng H, Liu GB, Song LQ, Zhao RY, Liu Y, Chen L, Wei B. Short and long-term outcomes between laparoscopic and open total gastrectomy for advanced gastric cancer after neoadjuvant chemotherapy. World J Gastrointest Surg 2022; 14:452-469. [PMID: 35734616 PMCID: PMC9160691 DOI: 10.4240/wjgs.v14.i5.452] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 01/17/2022] [Accepted: 04/22/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Neoadjuvant chemotherapy (NACT) combined with surgery is regarded as an effective treatment for advanced gastric cancer (AGC). Laparoscopic surgery represents the mainstream of minimally invasive surgery. Currently, surgeons focus more on surgical safety and oncological outcomes of laparoscopic gastrectomy after NACT. Thus, we sought to evaluate short- and long-term outcomes between laparoscopic total gastrectomy (LTG) and open total gastrectomy (OTG) after NACT.
AIM To compare the short and long-term outcomes between LTG and OTG for AGC after NACT.
METHODS We retrospectively collected the clinicopathological data of 136 patients who accepted gastrectomy after NACT from June 2012 to June 2019, including 61 patients who underwent LTG and 75 who underwent OTG. Clinicopathological characteristics between the LTG and OTG groups showed no significant difference. SPSS 26.0, R software, and GraphPad PRISM 8.0 were used to perform statistical analyses.
RESULTS Of the 136 patients included, eight acquired pathological complete response, and the objective response rate was 47.8% (65/136). The LTG group had longer operation time (P = 0.015), less blood loss (P = 0.003), shorter days to first flatus (P < 0.001), and shorter postoperative hospitalization days (P < 0.001). LTG spent more surgical cost than OTG (P < 0.001), while total hospitalized cost of LTG was less than OTG (P < 0.001). 21 (28.0%) patients in the OTG group and 14 (23.0%) in the LTG group had 30-d postoperative complications, but there was no significant difference between the two groups (P = 0.503). The 3-year overall survival (OS) rate was 60.6% and 64.6% in the LTG and OTG groups, respectively [hazard ratio (HR) = 0.859, 95% confidence interval (CI): 0.522-1.412, P = 0.546], while the 3-year disease-free survival (DFS) rate was 54.5% and 51.8% in the LTG and OTG group, respectively (HR = 0.947, 95%CI: 0.582-1.539, P = 0.823). Multivariate cox analysis showed that body mass index and pTNM stage were independent risk factors for OS while vascular invasion and pTNM stage were independent risk factors for DFS (P < 0.05).
CONCLUSION After NACT, LTG shows comparable 30-d postoperative morbidity as well as 3-year OS and DFS rate to OTG. We recommend that experienced surgeons select LTG other than OTG for proper AGC patients after NACT.
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Affiliation(s)
- Hao Cui
- School of Medicine, Nankai University, Tianjin 300071, China
| | - Ke-Cheng Zhang
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
| | - Bo Cao
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
- Medical School, Chinese PLA General Hospital, Beijing 100853, China
| | - Huan Deng
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
- Medical School, Chinese PLA General Hospital, Beijing 100853, China
| | - Gui-Bin Liu
- School of Medicine, Nankai University, Tianjin 300071, China
| | - Li-Qiang Song
- School of Medicine, Nankai University, Tianjin 300071, China
| | - Rui-Yang Zhao
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
- Medical School, Chinese PLA General Hospital, Beijing 100853, China
| | - Yi Liu
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
| | - Lin Chen
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
| | - Bo Wei
- Department of General Surgery and Institute of General Surgery, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
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9
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Cui H, Cao B, Deng H, Liu GB, Liang WQ, Xie TY, Ye L, Zhang QP, Wang N, Liu FD, Wei B. [A nomogram for predicting lymph node metastasis in early gastric cancer]. Zhonghua Wei Chang Wai Ke Za Zhi 2022; 25:40-47. [PMID: 35067033 DOI: 10.3760/cma.j.cn441530-20210208-00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Objective: To explore the independent risk factors of lymph node metastasis (LNM) in early gastric cancer, and to use nomogram to construct a prediction model for above LNM. Methods: A retrospective cohort study was conducted. Inclusion criteria: (1) primary early gastric cancer as stage pT1 confirmed by postoperative pathology; (2) complete clinicopathological data. Exclusion criteria: (1) patients with advanced gastric cancer, stump gastric cancer or history of gastrectomy; (2) early gastric cancer patients confirmed by pathology after neoadjuvant chemotherapy; (3) other types of gastric tumors, such as lymphoma, neuroendocrine tumor, stromal tumor, etc.; (4) primary tumors of other organs with gastric metastasis. According to the above criteria, 1633 patients with early gastric cancer who underwent radical gastrectomy at the Department of General Surgery of the Chinese PLA General Hospital First Medical Center from December 2005 to December 2020 were enrolled as training set, meanwhile 239 patients with early gastric cancer who underwent gastrectomy at the Department of General Surgery of the Chinese PLA General Hospital Fourth Medical Center from December 2015 to December 2020 were enrolled as external validation set. Risk factors of LNM in early gastric cancer were identified by using univariate and multivariate logistic regression analyses. A nomogram prediction model was established with significant factors screened by multivariate analysis. Area under the receiver operating characteristic curve (AUC) was used for assessing the predictive value of the model. Calibration curve was drawn for external validation. Results: Among 1633 patients in training set, the mean number of retrieved lymph nodes was 20 (13-28), and 209 patients (12.8%) had lymph node metastasis. Univariate analysis showed that gender, resection range, tumor location, tumor morphology, lymph node clearance, vascular invasion, lymphatic cancer thrombus, tumor length, tumor differentiation, microscopic presence of signet ring cells and depth of tumor invasion were associated with LNM (all P<0.05). Multivariate analysis revealed that females, tumor morphology as ulcer type, vascular invasion, lymphatic cancer thrombus, tumor length≥3 cm, deeper invasion of mucosa, and poor differentiation were independent risk factors for LNM in early gastric cancers (all P<0.05). Receiver operating characteristic curve indicated that AUC of training set was 0.818 (95%CI: 0.790-0.847) and AUC of external validation set was 0.765 (95%CI: 0.688-0.843). The calibration curve showed that the LNM probability predicted by nomogram was consistent with the actual situation (C-index: 0.818 in training set and 0.765 in external validation set). Conclusions: Females, tumor morphology as ulcer type, vascular invasion, lymphatic cancer thrombus, tumor length≥3 cm, deeper invasion of mucosa and poor differentiation are independent risk factors for LNM of early gastric cancer. The establishment of a nomogram prediction model for LNM in early gastric cancer has great diagnostic value and can provide reference for treatment selection.
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Affiliation(s)
- H Cui
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China School of Medicine, Nankai University, Tianjin 300071, China
| | - B Cao
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
| | - H Deng
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
| | - G B Liu
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China School of Medicine, Nankai University, Tianjin 300071, China
| | - W Q Liang
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
| | - T Y Xie
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China School of Medicine, Nankai University, Tianjin 300071, China
| | - L Ye
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China School of Medicine, Nankai University, Tianjin 300071, China
| | - Q P Zhang
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
| | - N Wang
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
| | - F D Liu
- Departmentof General Surgery, Chinese PLA General Hospital Fourth Medical Center, Beijing 100048, China
| | - B Wei
- Department of General Surgery & Instituteof General Surgery, Chinese PLA General Hospital First Medical Center, Beijing 100853, China
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10
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Deng H, Cui H, Cao B, Liu GB, Song LQ, Li HH, Zhao RY, Chen L, Wei B. [Analysis of influence factors for short-term recurrence of retroperitoneal liposarcoma after complete resection]. Zhonghua Wai Ke Za Zhi 2022; 60:52-56. [PMID: 34954947 DOI: 10.3760/cma.j.cn112139-20210401-00154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To examine the influence factors of short-term recurrence after complete surgical resection of retroperitoneal liposarcoma. Methods: The clinicopathological data of retroperitoneal liposarcoma at Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital from January 1, 2000 to January 31, 2020 were retrospectively analyzed. There were 60 males and 31 females, aged (52.1±9.9) years (range: 30 to 84 years). Tumor recurrence within 12 months after complete resection was defined as short-term recurrence, and tumor recurrence more than 12 months was defined as non-short-term recurrence. The t test, rank-sum test, χ2 test and Fisher exact test were conducted for inter-group comparison. Logistic regression analysis was used to analyze the independent influence factors for the short-term recurrence of retroperitoneal liposarcoma after complete resection. The Kaplan-Meier curve was used to calculate the recurrence-free survival, and the Log-rank test was adopted for the comparison between the groups. Results: The univariate analysis results showed that irregular tumor morphology, multiple pathological subtypes, pathological scores>3, and multiple primary tumors are influence factors for short-term recurrence after complete resection of retroperitoneal liposarcoma (χ2: 4.422 to 7.773, all P<0.05). Regression analysis of the above risk factors showed that multiple primary tumors was the independent risk factor (OR=2.918, 95%CI: 1.127 to 7.556, P=0.027). In the short-term recurrence group, Kaplan-Meier curve analysis showed that patients with multiple primary tumors had a shorter median recurrence time than patients with unifocal tumor (6 months vs. 9 months, P=0.028). Conclusions: Multiple primary tumor is an independent risk factor for short-term recurrence after complete resection of retroperitoneal liposarcoma. It suggests that the frequency of follow-up after surgery should be increased for such patients.
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Affiliation(s)
- H Deng
- Medical School of People's Liberation Army, Beijing 100853, China
| | - H Cui
- Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital, Beijing 100853, China
| | - B Cao
- Medical School of People's Liberation Army, Beijing 100853, China
| | - G B Liu
- Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital, Beijing 100853, China
| | - L Q Song
- Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital, Beijing 100853, China
| | - H H Li
- Medical School of People's Liberation Army, Beijing 100853, China
| | - R Y Zhao
- Medical School of People's Liberation Army, Beijing 100853, China
| | - L Chen
- Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital, Beijing 100853, China
| | - B Wei
- Department of General Surgery, the First Medical Center, People's Liberation Army General Hospital, Beijing 100853, China
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11
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Li JF, Hou CT, Li JJ, Peng H, Liu GB, Jiang ZT, Wang Q. [Corneal nerve repair and optical density in patients with high myopia after three kinds of corneal refractive surgery]. Zhonghua Yan Ke Za Zhi 2021; 57:268-276. [PMID: 33832051 DOI: 10.3760/cma.j.cn112142-20200612-00394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Objective: To investigate the repair of subepithelial nerve fibers in different areas of the cornea and the difference of corneal transparency 12 months after small incision lenticule extraction (SMILE), femtosecond laser in situ keratomileusis (FS-LASIK) and excimer laser in situ keratomileusis (LASEK) in high myopia. Methods: A cohort study. From June 2018 to October 2019, 30 patients with high myopia (60 eyes) were selected for corneal refractive surgery in the Department of Ophthalmology, Affiliated Hospital of Qingdao University, including 16 females (32 eyes) and 14 males (28 eyes). According to the mode of operation, the patients were divided into the SMILE group (n=10), FS-LASIK group (n=11) and LASEK group (n=9). The repair of subepithelial nerves in different areas of the cornea was observed by laser confocal microscopy 12 months after operation,and the morphological parameters were analyzed by ACCMetrics software. The parameters included corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal nerve fiber total branch density (CTBD) and corneal nerve fiber width. The Pentacam anterior segment analyzer was used to measure the optical density of the cornea in different diameters. The nerve fiber parameters and corneal optical density were compared by random block analysis of variance, and multiple comparisons were performed between groups by the Turkey test. Results: Twelve months after operation, there was no significant difference in the CNFD among the three groups(all P>0.05). The CNBD around the upper corneal incision in the SMILE group, FS-LASIK group and LASEK group was (7.81±7.93), (9.61±7.18) and (21.25±15.55) branches/mm2, respectively. The CTBD was (22.00±16.02), (24.44±11.42) and (54.37±22.13) branches/mm2, respectively. The values in the LASEK group significantly differed from the other two groups (HSD=2.823, -3.010, 3.053, -3.048, P<0.01). The CNFL was (9.19±3.25), (12.88±3.52) and (15.75±2.36) mm/mm2, respectively. The value in the SMILE group was significantly different (HSD=-3.151, -4.418; P<0.0l). The corneal optical density after SMILE was 13.16±0.72 in the 0-6 mm diameter area(HSD=-4.164, -4.489; P<0.01), 16.12±3.18 in the 6-12 mm diameter area(HSD=-3.918, -3.493;P<0.01) and 14.06±1.36 in the total diameter (HSD=-6.031, -5.519;P<0.01), which differed significantly from the other two groups. Conclusions: Twelve months after SMILE for high myopia, the nerve repair around the superior corneal incision is slightly worse than that after FS-LASIK and LASEK, but the nerve repair in other areas has some advantages, and the corneal transparency is better. (Chin J Ophthalmol, 2021, 57:268-276).
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Affiliation(s)
- J F Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - C T Hou
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - J J Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - H Peng
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - G B Liu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Z T Jiang
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Q Wang
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, China
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12
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Wang Q, Gao H, Li J, Liu GB, Jin H. Importance of Crystallographic Sites on Sodium-Ion Extraction from NASICON-Structured Cathodes for Sodium-Ion Batteries. ACS Appl Mater Interfaces 2021; 13:14312-14320. [PMID: 33749228 DOI: 10.1021/acsami.1c01663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The V4+/V3+ (3.4 V) redox couple has been well-documented in cathode material Na3V2(PO4)3 for sodium-ion batteries. Recently, partial cation substitution at the vanadium site of Na3V2(PO4)3 has been actively explored to access the V5+/V4+ redox couple to achieve high energy density. However, the V5+/V4+ redox couple in partially substituted Na3V2(PO4)3 has a voltage far below its theoretical voltage in Na3V2(PO4)3, and the access of the V5+/V4+ redox reaction is very limited. In this work, we compare the extraction/insertion behavior of sodium ions from/into two isostructural compounds of Na3VGa(PO4)3 and Na3VAl(PO4)3, found that, by DFT calculations, the lower potential of the V5+/V4+ redox couple in Na3VM(PO4)3 (M = Ga or Al) than that in Na3V2(PO4)3 is because of the extraction/insertion of sodium ions through the V5+/V4+ redox reaction at different crystallographic sites, that is, sodium ions extracting from the Na(2) site in Na3VM(PO4)3 while from the Na(1) site in Na3V2(PO4)3, and further evidenced that the full access of the V5+/V4+ redox reaction is restrained by the excessive diffusion activation energy in Na3VM(PO4)3.
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Affiliation(s)
- Qianchen Wang
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Hongcai Gao
- School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
- Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, P. R. China
| | - Jingbo Li
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Gui-Bin Liu
- School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Haibo Jin
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
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13
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Pan D, Liu C, Liu GB, Feng S, Yao Y. Physical Fingerprints of the 2O-tαP Phase in Phosphorene Stacking. J Phys Chem Lett 2019; 10:3190-3196. [PMID: 31144818 DOI: 10.1021/acs.jpclett.9b01323] [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: 06/09/2023]
Abstract
The 2O-tαP phase is a bilayer phosphorene stacking twisted by ∼70.5° standing out from all the potential candidates predicted by our previous work. Here, by linear response theory, we directly verified that the 2O-tαP phase preserves the intrinsic features of phonon spectrum of the existing AB phase, reflecting a stable thermodynamic behavior. Then we provided three distinct fingerprints to help finding this new phase: upon comparison to the existing shifting bilayer phosphorene, the in-plane elastic constants showed a much weaker anisotropic response, providing a characteristic mechanical criterion; the calculated Raman spectrum revealed for the low frequency rang the layer-breathing mode and the out-of-plane twisted mode, L-A1 and L-A2, both of which together stabilize the twisted structure; in particular, the simulated scanning tunneling microscope image presented recognizable cross stripes, which should withstand an examination of exfoliated bilayer and few-layer black phosphorus.
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Affiliation(s)
- Douxing Pan
- Bio-inspired Robotics and Intelligent Material Laboratory, Institute of Advanced Manufacturing Technology , Hefei Institutes of Physical Science, Chinese Academy of Sciences , Changzhou 213164 , China
- Key Laboratory of Materials Physics, Institute of Solid State Physics , Hefei Institutes of Physical Science , Chinese Academy of Sciences, Hefei 230031 , China
| | - Changsong Liu
- Key Laboratory of Materials Physics, Institute of Solid State Physics , Hefei Institutes of Physical Science , Chinese Academy of Sciences, Hefei 230031 , China
| | - Gui-Bin Liu
- Laboratory of Quantum Functional Material Design and Application, School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| | - Song Feng
- Bio-inspired Robotics and Intelligent Material Laboratory, Institute of Advanced Manufacturing Technology , Hefei Institutes of Physical Science, Chinese Academy of Sciences , Changzhou 213164 , China
| | - Yugui Yao
- Laboratory of Quantum Functional Material Design and Application, School of Physics , Beijing Institute of Technology , Beijing 100081 , China
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14
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Wu Z, Zhou BT, Cai X, Cheung P, Liu GB, Huang M, Lin J, Han T, An L, Wang Y, Xu S, Long G, Cheng C, Law KT, Zhang F, Wang N. Intrinsic valley Hall transport in atomically thin MoS 2. Nat Commun 2019; 10:611. [PMID: 30723283 PMCID: PMC6363770 DOI: 10.1038/s41467-019-08629-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 01/23/2019] [Indexed: 11/25/2022] Open
Abstract
Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom in addition to charge and spin. In the absence of inversion symmetry, these systems were predicted to exhibit opposite Hall effects for electrons from different valleys. Such valley Hall effects have been achieved only by extrinsic means, such as substrate coupling, dual gating, and light illuminating. Here we report the first observation of intrinsic valley Hall transport without any extrinsic symmetry breaking in the non-centrosymmetric monolayer and trilayer MoS2, evidenced by considerable nonlocal resistance that scales cubically with local resistance. Such a hallmark survives even at room temperature with a valley diffusion length at micron scale. By contrast, no valley Hall signal is observed in the centrosymmetric bilayer MoS2. Our work elucidates the topological origin of valley Hall effects and marks a significant step towards the purely electrical control of valley degree of freedom in topological valleytronics. Electrons hopping in two-dimensional honeycomb lattices possess a valley degree of freedom. Here, the authors observe room-temperature valley Hall transport without any extrinsic symmetry breaking in the non-centrosymmetric monolayer and trilayer MoS2 by purely electronic means, whereas no valley signal is detected for centrosymmetric bilayer MoS2.
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Affiliation(s)
- Zefei Wu
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China.
| | - Benjamin T Zhou
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiangbin Cai
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Patrick Cheung
- Department of Physics, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Gui-Bin Liu
- School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Meizhen Huang
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Jiangxiazi Lin
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Tianyi Han
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Liheng An
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Yuanwei Wang
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Shuigang Xu
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Gen Long
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Chun Cheng
- Department of Materials Science and Engineering, Southern University of Science and Technology, 518055, Shenzhen, China
| | - Kam Tuen Law
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Fan Zhang
- Department of Physics, University of Texas at Dallas, Richardson, TX, 75080, USA.
| | - Ning Wang
- Department of Physics and the Center for Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China.
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15
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Liu GB, Cui XQ, Wang ZB, Wen L, Duan HL. Detection of serum procalcitonin and hypersensitive C-reactive protein in patients with pneumonia and sepsis. J BIOL REG HOMEOS AG 2018; 32:1165-1169. [PMID: 30334408] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Sepsis, a systemic inflammatory response syndrome induced by infection, has high rates of morbidity and mortality. Pneumonia is a major cause for sepsis; however, pneumonia complicated by sepsis is a difficult clinical diagnosis. To assess the clinical relevance of serum procalcitonin (PCT) and hypersensitive C-reactive protein (hs-CRP) in early diagnosis of pneumonia complicated by sepsis, 220 patients with pneumonia who were admitted to hospital from July 2015 to July 2016 were enrolled in this study. The patients were divided into non-sepsis (N=82), mild sepsis (N=97), severe sepsis (N=23), and septic shock (N=18) groups. The patients were also divided into a survival group (N=186) and a death group (N=34) according to their prognosis at 2 weeks. The PCT and hs-CRP levels and Acute Physiology and Chronic Health Evaluation-II (APACHE-II) scores of the two groups were evaluated. The PCT level and APACHE-II score showed a progressively increasing tendency in the non-sepsis, mild sepsis, severe sepsis, and septic shock group; the differences between all pairs of groups were significant (P less than 0.05). The hs-CRP level was significantly lower in the non-sepsis group than in the other groups (P less than 0.05), but differences among the other groups were not significant (P>0.05). The areas under the receiver operating characteristic curves of PCT and hs-CRP for diagnosis of pneumonia complicated by mild and severe sepsis were 0.841 and 0.817, respectively. The optimal cut-off points for pneumonia and sepsis were ≥0.5 ng/mL and ≥55 mg/L, respectively; the sensitivity and specificity were 71.42% and 82.13%, and 75.04% and 53.61%, respectively. The sensitivity and specificity of diagnosis based on PCT and hs-CRP were 89.32% and 85.68%, respectively. PCT and hs-CRP are used to assess the severity of pneumonia in combination with sepsis in new-borns, but PCT is more strongly related to the severity of sepsis than is hs-CRP. Detection of PCT in combination with hs-CRP facilitates the early diagnosis of pneumonia and sepsis in new-borns, as well as monitoring of the treatment response and prediction of the prognosis.
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Affiliation(s)
- G B Liu
- Clinico-Medical Biochemistry Laboratory, Department of Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad, Pakistan
| | - X Q Cui
- Hemodialysis Room, Binzhou City Center Hospital, Bingzhou, China
| | - Z B Wang
- Neurosurgery, Binzhou City Center Hospital, Bingzhou, China
| | - L Wen
- Ophthalmology Department, Binzhou City Center Hospital, Bingzhou, China
| | - H L Duan
- Hemodialysis Room, Binzhou City Center Hospital, Bingzhou, China
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16
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Yu H, Liu GB, Tang J, Xu X, Yao W. Moiré excitons: From programmable quantum emitter arrays to spin-orbit-coupled artificial lattices. Sci Adv 2017; 3:e1701696. [PMID: 29152568 PMCID: PMC5681217 DOI: 10.1126/sciadv.1701696] [Citation(s) in RCA: 211] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 10/18/2017] [Indexed: 05/20/2023]
Abstract
Highly uniform and ordered nanodot arrays are crucial for high-performance quantum optoelectronics, including new semiconductor lasers and single-photon emitters, and for synthesizing artificial lattices of interacting quasiparticles toward quantum information processing and simulation of many-body physics. Van der Waals heterostructures of two-dimensional semiconductors are naturally endowed with an ordered nanoscale landscape, that is, the moiré pattern that laterally modulates electronic and topographic structures. We find that these moiré effects realize superstructures of nanodot confinements for long-lived interlayer excitons, which can be either electrically or strain tuned from perfect arrays of quantum emitters to excitonic superlattices with giant spin-orbit coupling (SOC). Besides the wide-range tuning of emission wavelength, the electric field can also invert the spin optical selection rule of the emitter arrays. This unprecedented control arises from the gauge structure imprinted on exciton wave functions by the moiré, which underlies the SOC when hopping couples nanodots into superlattices. We show that the moiré hosts complex hopping honeycomb superlattices, where exciton bands feature a Dirac node and two Weyl nodes, connected by spin-momentum-locked topological edge modes.
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Affiliation(s)
- Hongyi Yu
- Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, China
| | - Gui-Bin Liu
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Jianju Tang
- Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA 98195, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA
| | - Wang Yao
- Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, China
- Corresponding author.
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Wu Z, Xu S, Lu H, Khamoshi A, Liu GB, Han T, Wu Y, Lin J, Long G, He Y, Cai Y, Yao Y, Zhang F, Wang N. Even-odd layer-dependent magnetotransport of high-mobility Q-valley electrons in transition metal disulfides. Nat Commun 2016; 7:12955. [PMID: 27651106 PMCID: PMC5036047 DOI: 10.1038/ncomms12955] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 08/15/2016] [Indexed: 11/09/2022] Open
Abstract
In few-layer transition metal dichalcogenides (TMDCs), the conduction bands along the ΓK directions shift downward energetically in the presence of interlayer interactions, forming six Q valleys related by threefold rotational symmetry and time reversal symmetry. In even layers, the extra inversion symmetry requires all states to be Kramers degenerate; whereas in odd layers, the intrinsic inversion asymmetry dictates the Q valleys to be spin-valley coupled. Here we report the transport characterization of prominent Shubnikov-de Hass (SdH) oscillations and the observation of the onset of quantum Hall plateaus for the Q-valley electrons in few-layer TMDCs. Universally in the SdH oscillations, we observe a valley Zeeman effect in all odd-layer TMDC devices and a spin Zeeman effect in all even-layer TMDC devices, which provide a crucial information for understanding the unique properties of multi-valley band structures of few-layer TMDCs. Few-layer transition metal dichalcogenides exhibit strong spin-valley entanglement and unconventional quantum Hall states, however their study has been limited by electron mobility. Here, the authors explore how quantum transport varies between even- and odd-layered systems of high mobility.
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Affiliation(s)
- Zefei Wu
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Shuigang Xu
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Huanhuan Lu
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Armin Khamoshi
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - Gui-Bin Liu
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Tianyi Han
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Yingying Wu
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Jiangxiazi Lin
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Gen Long
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Yuheng He
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Yuan Cai
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
| | - Yugui Yao
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Fan Zhang
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - Ning Wang
- Department of Physics and the Center for 1D/2D Quantum Materials, the Hong Kong University of Science and Technology, Hong Kong, China
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18
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Li YL, Liu GB, Cheng DF, Shi HC. [Research progress in metabolic and receptor-like nuclear imaging agents for hepatocellular carcinoma]. Zhonghua Gan Zang Bing Za Zhi 2016; 24:619-623. [PMID: 27788712 DOI: 10.3760/cma.j.issn.1007-3418.2016.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Hepatocellular carcinoma (HCC) commonly presents with high morbidity and mortality, and early staging diagnosis and timely treatment is pivotal to prolonging patients' survival time. Compared with traditional morphological imaging methods such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), functional imaging methods like single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are playing an increasingly important role in the early diagnosis, efficacy assessment, prognostic evaluation, and treatment planning for HCC, thanks to their higher sensitivity at a molecular level by using various radiopharmaceuticals.
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Affiliation(s)
- Y L Li
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University; Shanghai Institute of Medical Imaging, Shanghai 200032, China
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19
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Liu H, Chen J, Yu H, Yang F, Jiao L, Liu GB, Ho W, Gao C, Jia J, Yao W, Xie M. Observation of intervalley quantum interference in epitaxial monolayer tungsten diselenide. Nat Commun 2015; 6:8180. [PMID: 26324205 PMCID: PMC4569794 DOI: 10.1038/ncomms9180] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 07/27/2015] [Indexed: 11/09/2022] Open
Abstract
The extraordinary electronic structures of monolayer transition metal dichalcogenides, such as the spin-valley-coupled band edges, have sparked great interest for potential spintronic and valleytronic applications based on these two-dimensional materials. In this work, we report the experimental observation of quasi-particle interference patterns in monolayer WSe2 using low-temperature scanning tunnelling spectroscopy. We observe intervalley quantum interference involving the Q valleys in the conduction band due to spin-conserving scattering processes, while spin-flipping intervalley scattering is absent. Our results establish unequivocally the presence of spin-valley coupling and affirm the large spin splitting at the Q valleys. Importantly, the inefficient spin-flipping scattering implies long valley and spin lifetime in monolayer WSe2, which is a key figure of merit for valley-spintronic applications.
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Affiliation(s)
- Hongjun Liu
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Jinglei Chen
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Hongyi Yu
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong.,Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Fang Yang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Lu Jiao
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Gui-Bin Liu
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Wingking Ho
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Chunlei Gao
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.,Innovation Center of Advanced Microstructures, Nanjing, China
| | - Jinfeng Jia
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.,Innovation Center of Advanced Microstructures, Nanjing, China
| | - Wang Yao
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong.,Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Maohai Xie
- Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong
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20
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Liu GB, Xiao D, Yao Y, Xu X, Yao W. Electronic structures and theoretical modelling of two-dimensional group-VIB transition metal dichalcogenides. Chem Soc Rev 2015; 44:2643-63. [DOI: 10.1039/c4cs00301b] [Citation(s) in RCA: 443] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Two-dimensional group-VIB transition metal dichalcogenides have extraordinary properties originating from their complex electronic structures.
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Affiliation(s)
- Gui-Bin Liu
- School of Physics
- Beijing Institute of Technology
- Beijing 100081
- China
- Department of Physics and Center of Theoretical and Computational Physics
| | - Di Xiao
- Department of Physics
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Yugui Yao
- School of Physics
- Beijing Institute of Technology
- Beijing 100081
- China
| | - Xiaodong Xu
- Department of Physics
- University of Washington
- Seattle
- USA
- Department of Material Science and Engineering
| | - Wang Yao
- Department of Physics and Center of Theoretical and Computational Physics
- The University of Hong Kong
- Hong Kong
- China
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21
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Yu H, Wu Y, Liu GB, Xu X, Yao W. Nonlinear valley and spin currents from Fermi pocket anisotropy in 2D crystals. Phys Rev Lett 2014; 113:156603. [PMID: 25375729 DOI: 10.1103/physrevlett.113.156603] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Indexed: 06/04/2023]
Abstract
The controlled flow of spin and valley pseudospin is key to future electronics exploiting these internal degrees of freedom of carriers. Here, we discover a universal possibility for generating spin and valley currents by electric bias or temperature gradient only, which arises from the anisotropy of Fermi pockets in crystalline solids. We find spin and valley currents to the second order in the electric field as well as their thermoelectric counterparts, i.e., the nonlinear spin and valley Seebeck effects. These second-order nonlinear responses allow two unprecedented possibilities to generate pure spin and valley flows without net charge current: (i) by an ac bias or (ii) by an arbitrary inhomogeneous temperature distribution. As examples, we predict appreciable nonlinear spin and valley currents in two-dimensional (2D) crystals including graphene, monolayer and trilayer transition-metal dichalcogenides, and monolayer gallium selenide. Our finding points to a new route towards electrical and thermal generations of spin and valley currents for spintronic and valleytronic applications based on 2D quantum materials.
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Affiliation(s)
- Hongyi Yu
- Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China
| | - Yue Wu
- Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China
| | - Gui-Bin Liu
- Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China and School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, Washington 98195, USA and Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Wang Yao
- Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China
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22
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Zeng H, Liu GB, Dai J, Yan Y, Zhu B, He R, Xie L, Xu S, Chen X, Yao W, Cui X. Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides. Sci Rep 2013; 3:1608. [PMID: 23575911 PMCID: PMC3622914 DOI: 10.1038/srep01608] [Citation(s) in RCA: 346] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/18/2013] [Indexed: 11/09/2022] Open
Abstract
We report systematic optical studies of WS2 and WSe2 monolayers and multilayers. The efficiency of second harmonic generation shows a dramatic even-odd oscillation with the number of layers, consistent with the presence (absence) of inversion symmetry in even-layer (odd-layer). Photoluminescence (PL) measurements show the crossover from an indirect band gap semiconductor at multilayers to a direct-gap one at monolayers. A hot luminescence peak (B) is observed at ~0.4 eV above the prominent band edge peak (A) in all samples. The magnitude of A-B splitting is independent of the number of layers and coincides with the spin-valley coupling strength in monolayers. Ab initio calculations show that this thickness independent splitting pattern is a direct consequence of the giant spin-valley coupling which fully suppresses interlayer hopping at valence band edge near K points because of the sign change of the spin-valley coupling from layer to layer in the 2H stacking order.
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Affiliation(s)
- Hualing Zeng
- Department of Physics, The University of Hong Kong, Pokfulam road, Hong Kong, China
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23
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Xiao D, Liu GB, Feng W, Xu X, Yao W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys Rev Lett 2012; 108:196802. [PMID: 23003071 DOI: 10.1103/physrevlett.108.196802] [Citation(s) in RCA: 1393] [Impact Index Per Article: 116.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 03/21/2012] [Indexed: 05/20/2023]
Abstract
We show that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides, making possible controls of spin and valley in these 2D materials. The spin-valley coupling at the valence-band edges suppresses spin and valley relaxation, as flip of each index alone is forbidden by the valley-contrasting spin splitting. Valley Hall and spin Hall effects coexist in both electron-doped and hole-doped systems. Optical interband transitions have frequency-dependent polarization selection rules which allow selective photoexcitation of carriers with various combination of valley and spin indices. Photoinduced spin Hall and valley Hall effects can generate long lived spin and valley accumulations on sample boundaries. The physics discussed here provides a route towards the integration of valleytronics and spintronics in multivalley materials with strong spin-orbit coupling and inversion symmetry breaking.
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Affiliation(s)
- Di Xiao
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
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24
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Liu GB, Liu BG. Temperature-dependent striped antiferromagnetism of LaFeAsO in a Green's function approach. J Phys Condens Matter 2009; 21:195701. [PMID: 21825495 DOI: 10.1088/0953-8984/21/19/195701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We use a Green's function method to study the temperature-dependent average moment and magnetic phase-transition temperature of the striped antiferromagnetism of LaFeAsO, and other similar compounds, as the parents of FeAs-based superconductors. We consider the nearest and the next-nearest couplings in the FeAs layer, and the nearest coupling for inter-layer spin interaction. The dependence of the transition temperature T(N) and the zero-temperature average spin on the interaction constants is investigated. We obtain an analytical expression for T(N) and determine our temperature-dependent average spin from zero temperature to T(N) in terms of unified self-consistent equations. For LaFeAsO, we obtain a reasonable estimation of the coupling interactions with the experimental transition temperature T(N) = 138 K. Our results also show that a non-zero antiferromagnetic (AFM) inter-layer coupling is essential for the existence of a non-zero T(N), and the many-body AFM fluctuations reduce substantially the low-temperature magnetic moment per Fe towards the experimental value. Our Green's function approach can be used for other FeAs-based parent compounds and these results should be useful to understand the physical properties of FeAs-based superconductors.
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Affiliation(s)
- Gui-Bin Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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25
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Affiliation(s)
- O L Carter
- Vision, Touch and Hearing Research Centre, University of Queensland, St Lucia, Australia 4072.
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26
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Abstract
BACKGROUND The rate of binocular rivalry has been reported to be slower in subjects with bipolar disorder than in controls when tested with drifting, vertical and horizontal gratings of high spatial frequency. METHOD Here we assess the rate of binocular rivalry with stationary, vertical and horizontal gratings of low spatial frequency in 30 subjects with bipolar disorder, 30 age- and sex-matched controls, 18 subjects with schizophrenia and 18 subjects with major depression. Along with rivalry rate, the predominance of each of the rivaling images was assessed, as was the distribution of normalized rivalry intervals. RESULTS The bipolar group demonstrated significantly slower rivalry than the control, schizophrenia and major depression groups. The schizophrenia and major depression groups did not differ significantly from the control group. Predominance values did not differ according to diagnosis and the distribution of normalized rivalry intervals was well described by a gamma function in all groups. CONCLUSIONS The results provide further evidence that binocular rivalry is slow in bipolar disorder and demonstrate that rivalry predominance and the distribution of normalized rivalry intervals are not abnormal in bipolar disorder. It is also shown by comparison with previous work, that high strength stimuli more effectively distinguish bipolar from control subjects than low strength stimuli. The data on schizophrenia and major depression suggest the need for large-scale specificity trials. Further study is also required to assess genetic and pathophysiological factors as well as the potential effects of state, medication, and clinical and biological subtypes.
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Affiliation(s)
- S M Miller
- Cognitive Psychophysiology Laboratory, Central Clinical School, Vision Touch and Hearing Research Centre, University of Queensland, Prince Charles Hospital, Brisbane, Queensland, Australia
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Liu GB, Mark RF. Functional development of the inferior colliculus (IC) and its relationship with the auditory brainstem response (ABR) in the tammar wallaby (Macropus eugenii). Hear Res 2001; 157:112-23. [PMID: 11470191 DOI: 10.1016/s0378-5955(01)00289-1] [Citation(s) in RCA: 4] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To discover the developmental relationship between the auditory brainstem response (ABR) and the focal inferior colliculus (IC) response, 32 young tammar wallabies were used, by the application of simultaneous ABR and focal brainstem recordings, in response to acoustic clicks and tone bursts of seven frequencies. The IC of the tammar wallaby undergoes a rapid functional development from postnatal day (PND) 114 to 160. The earliest (PND 114) auditory evoked response was recorded from the rostral IC. With development, more caudal parts of the IC became functional until age about PND 127, when all parts of the IC were responsive to sound. Along a dorsoventral direction, the duration of the IC response decreased, the peak latency shortened, while the amplitude increased, reaching a maximum value at the central IC, then decreased. After PND 160, the best frequency (BF) of the ventral IC was the highest, with values between 12.5 and 16 kHz, the BF of the dorsal IC was the lowest, varying between 3.2 and 6.4 kHz, while the BF of the central IC was between 6.4 and 12.5 kHz. Between PND 114 and 125, the IC response did not have temporal correlation with the ABR. Between PND 140 and 160, only the early components of the responses from the ventral and central IC correlated with the P4 waves of the ABR. After PND 160, responses recorded from different depths of the IC had a temporal correlation with the ABR.
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Affiliation(s)
- G B Liu
- Vision, Touch and Hearing Research Centre, The University of Queensland, St. Lucia, Brisbane, Australia.
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28
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Liu GB, Hill KG, Mark RF. Temporal relationship between the auditory brainstem response and focal responses of auditory nerve root and cochlear nucleus during development in the tammar wallaby (Macropus eugenii). Audiol Neurootol 2001; 6:140-53. [PMID: 11474140 DOI: 10.1159/000046821] [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: 11/19/2022] Open
Abstract
Thirty-two pouch-young tammar wallabies were used to discover the generators of the auditory brainstem response (ABR) during development by the use of simultaneous ABR and focal brainstem recordings. A click response from the auditory nerve root (ANR) in the wallaby was recorded from postnatal day (PND) 101, when no central auditory station was functional, and coincided with the ABR, a simple positive wave. The response of the cochlear nucleus (CN) was detected from PND 110, when the ABR had developed 1 positive and 1 negative peak. The dominant component of the focal ANR response, the N1 wave, coincided with the first half of the ABR P wave, and that of the focal CN response, the N1 wave, coincided with the later two thirds. In older animals, the ANR response coincided with the ABR's N1 wave, while the CN response coincided with the ABR's P2, N2 and P3 waves, with its contribution to the ABR P2 dominant. The protracted development of the marsupial auditory system which facilitated these correlations makes the tammar wallaby a particularly suitable model.
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Affiliation(s)
- G B Liu
- Vision Touch and Hearing Research Centre, Department of Physiology and Pharmacology, University of Queensland, Brisbane, Qld., Australia
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Abstract
BACKGROUND Binocular rivalry refers to the alternating perceptual states that occur when the images seen by the two eyes are too different to be fused into a single percept. Logothetis and colleagues have challenged suggestions that this phenomenon occurs early in the visual pathway. They have shown that, in alert monkeys, neurons in the primary visual cortex continue to respond to their preferred stimulus despite the monkey reporting its absence. Moreover, they found that neural activity higher in the visual pathway is highly correlated with the monkey's reported percept. These and other findings suggest that the neural substrate of binocular rivalry must involve high levels, perhaps the same levels involved in reversible figure alternations. RESULTS We present evidence that activation or disruption of a single hemisphere in human subjects affects the perceptual alternations of binocular rivalry. Unilateral caloric vestibular stimulation changed the ratio of time spent in each competing perceptual state. Transcranial magnetic stimulation applied to one hemisphere disrupted normal perceptual alternations when the stimulation was timed to occur at one phase of the perceptual switch, but not at the other. Furthermore, activation of a single hemisphere by caloric stimulation affected the perceptual alternations of a reversible figure, the Necker cube. CONCLUSIONS Our findings suggest that interhemispheric switching mediates perceptual rivalry. Thus, competition for awareness in both binocular rivalry and reversible figures occurs between, rather than within, each hemisphere. This interhemispheric switch hypothesis has implications for understanding the neural mechanisms of conscious experience and also has clinical relevance as the rate of both types of perceptual rivalry is slow in bipolar disorder (manic depression).
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Affiliation(s)
- S M Miller
- Vision, Touch and Hearing Research Centre, Department of Physiology and Pharmacology, The University of Queensland, Brisbane, 4072, Australia.
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Graham MC, Scher HI, Liu GB, Yeh SD, Curley T, Daghighian F, Goldsmith SJ, Larson SM. Rhenium-186-labeled hydroxyethylidene diphosphonate dosimetry and dosing guidelines for the palliation of skeletal metastases from androgen-independent prostate cancer. Clin Cancer Res 1999; 5:1307-18. [PMID: 10389913] [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: 02/13/2023]
Abstract
Rhenium-186 (tin)-labeled hydroxyethylidene diphosphonate (186Re-labeled HEDP) was evaluated in 27 men with progressive androgen-independent prostate cancer and bone metastases. Administered activities ranged from 1251 to 4336 MBq (33.8-117.2 mCi). The primary objectives were to assess tumor targeting, normal organ dosimetry, and safety. Antitumor effects were assessed by posttherapy changes in prostate-specific antigen and, when present, palliation of pain. Whole-body kinetics, blood and kidney clearance, skeletal dose, marrow dose, and urinary excretion of the isotope were assessed. Targeting of skeletal disease was observed over the period of quantification (4-168 h). Radiation doses to whole body, bladder, and kidney were well tolerated. The dose-limiting toxicity was myelosuppression (grade III) at 4107 MBq (111 mCi) and grade II at 296 MBq (80 mCi). Probe clearance (whole body) and urinary excretion measurements were highly correlated. Of the six patients treated at the highest dosage schedules (three at 1510 MBq/m2 and three at 1665 MBq/m2), three showed a posttherapy decline in prostate-specific antigen of 50% or more. The declines were not sustained. The determination of total activity retained at 24 h, as well as an estimate of marrow dose, correlated with the amount of myelosuppression observed. These results suggest that a single 24-h measurement of retained activity would allow individualized dosing and an improved therapeutic index relative to fixed dosing schema. Repetitive dosing is required to increase palliation.
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Affiliation(s)
- M C Graham
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
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32
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Abstract
Auditory brainstem responses (ABRs) were evoked in developing wallabies by click and tone burst stimuli delivered by bone conduction and air conduction, at progressive stages of post-natal (pouch) life. ABRs were recorded through the onset of auditory responses (95-110 days), the opening of the external ear canal (125-130 days) and the maturation of ABR thresholds and latencies to values corresponding to those in adults ( > 180 days). ABRs were evoked in response to bone-conducted clicks some days prior to the age at which an acoustically evoked response was first observed (around 95 days of pouch life). ABRs could be evoked by bone-conducted and intense air-conducted stimuli prior to opening of the ear canal. A trend of decreasing threshold and latency with age was observed for both modes of stimulation. The morphology of the ABR became more complex, according to both increased age and increased stimulus intensity. The ABR waveforms indicated relatively greater mechanosensitivity to bone-conducted stimuli than to air-conducted stimuli, prior to opening of the ear canal. Following opening of the ear canal, thresholds to air-conducted clicks and tones were substantially reduced and decreased further over the next 10-20 days, while thresholds to bone-conducted clicks continued slowly to decrease. Thresholds to tone bursts in the centre frequency range (4-12 kHz) remained less than those for low (0.5-1.5 kHz) and higher (16 kHz) frequencies. Latencies of an identified peak in ABR waveforms characteristically decreased with age (at constant stimulus intensity) and with stimulus intensity (for a given age). ABR waveforms obtained at progressive ages, but judged to be at corresponding sensation levels, underwent maturational changes, independent of conductive aspects of the wallabies' hearing, for 2-3 weeks after opening of the ear canal.
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Affiliation(s)
- K G Hill
- Research School of Biological Sciences, Australian National University, Canberra.
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Abstract
Auditory brainstem responses (ABR) elicited by click and tonal stimuli were recorded from the tammar wallaby (Macropus eugenii), a marsupial mammal. The morphology, threshold, amplitude, and latency of ABRs recorded in the tammar wallaby are similar to those of other marsupials and mammals used in auditory research, including humans. Thresholds determined by an algorithm employing cross-correlation and by conventional visual detection methods were comparable. The findings from this study indicate that tammar wallaby is a suitable model for auditory research and that algorithms employing cross-correlation are useful for detection of the ABR waveform.
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Affiliation(s)
- B K Cone-Wesson
- Developmental Neurobiology Group, Research School of Biological Sciences, Australian National University, Canberra, Australia.
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Withington DJ, Mark RF, Thornton SK, Liu GB, Hill KG. Neural responses to free-field auditory stimulation in the superior colliculus of the wallaby (Macropus eugenii). Exp Brain Res 1995; 105:233-40. [PMID: 7498376 DOI: 10.1007/bf00240959] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Auditory responses to free-field broad band stimulation from different directions were recorded from clusters of neurones in the superior colliculus (SC) of the anaesthetized tammar wallaby. The auditory responses were found approximately 2 mm beneath the first recording of visually evoked responses in the superficial layers, the vast majority being solely auditory in nature; only one recording responded to both auditory and visual stimulation. Responses to suprathreshold intensities displayed sharp spatial tuning to sound in the contralateral hemifield. Those from the rostral pole of the SC disclosed a preference for auditory stimuli in the azimuthal anterior field, whereas those in the caudal SC preferentially responded to sounds in the posterior field. A continuum of directionally tuned responses was seen along the rostrocaudal axis of the SC so that the entire azimuthal contralateral auditory hemifield was represented in the SC. Furthermore, tight spatial alignment was evident between the best position of the visual responses in the superficial layers in azimuth and the peak angle of the auditory response in the deeper layers.
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Fortune HT, Liu GB, O'Donnell JM, Silk JD, Mordechai S. Energy dependence of 58Ni( pi +, pi -)58Zn double charge exchange. Phys Rev C Nucl Phys 1994; 50:306-308. [PMID: 9969661 DOI: 10.1103/physrevc.50.306] [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: 05/22/2023]
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Guobin L, Kemp DR, Liu GB. Water stress affects the productivity, growth components, competitiveness and water relations of phalaris and white clover growing in a mixed pasture. ACTA ACUST UNITED AC 1992. [DOI: 10.1071/ar9920659] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effect of water stress during summer and recovery after rain on herbage accumulation, leaf growth components, stomatal conductance and leaf water relations of white clover (Trifolium repens cv. Haifa) and phalaris (Phalaris aquatica cv. Australian Commercial) was studied in an established mixed pasture under dryland (dry) or irrigated (wet) conditions. Soil water deficits under dry conditions reached 150 mm and soil water potentials in the top 20 cm declined to nearly -2 MPa after 50 days of dry weather. Water stress severely restricted growth of both species but then after rain fell, white clover growth rates exceeded those of phalaris. Under irrigation, white clover produced twice the herbage mass of phalaris but under dry conditions herbage production was similar from both species. Leaf appearance rates per tiller or stolon were slightly higher for white clover than phalaris but were reduced by 20% under water stress in both species. Leaf or petiole extension rates were more sensitive to water stress than leaf appearance rates and declined by 75% in phalaris and 90% in white clover. The ratio of leaf or petiole extension rates on dry/wet treatments was similar for both species in relation to leaf relative water contents, but in relation to leaf water potentials phalaris maintained higher leaf growth rates. Phalaris maintained a higher leaf relative water content in relation to leaf water potentials than did white clover and also maintained higher leaf water potentials in relation to the soil water potential in the top 20 cm. Stomata1 conductances for both species declined by 80-90% with increasing water stress, and both species showed similar stomatal responses to bulk leaf water potentials and leaf relative water contents. It is suggested that the poorer performance of white clover under water stress may be due principally to a shallower root system than phalaris and not due to any underlying major physiological differences. The white clover cultivar used in this study came from the mediterranean region and showed some different responses to water stress than previously published evidence on white clover. This suggests genetic variation in responses to water stress may exist within white clover. To maintain white clover in a pasture under dry conditions it is suggested that grazing practices aim to retain a high proportion of growing points.
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Moore CF, Johnson K, Kahrimanis GP, McDonald J, Snell M, Ward HJ, Yoo SH, Morris CL, Mordechai S, Burlein M, Claytor N, Fortune HT, Ivie R, Liu GB, O'Donnell JM, Smith D, Auerbach N, Robson D. Angular distributions for the double isobaric analog and a T< state at high excitation in pion double charge exchange on 93Nb. Phys Rev C Nucl Phys 1991; 44:2209-2212. [PMID: 9967641 DOI: 10.1103/physrevc.44.2209] [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: 05/22/2023]
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