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Zhao D, Zhou YB, Fu Y, Wang L, Zhou XF, Cheng H, Li J, Song DW, Li SJ, Kang BL, Zheng LX, Nie LP, Wu ZM, Shan M, Yu FH, Ying JJ, Wang SM, Mei JW, Wu T, Chen XH. Intrinsic Spin Susceptibility and Pseudogaplike Behavior in Infinite-Layer LaNiO_{2}. Phys Rev Lett 2021; 126:197001. [PMID: 34047570 DOI: 10.1103/physrevlett.126.197001] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/25/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
The recent discovery of superconductivity in doped infinite-layer nickelates has stimulated intensive interest, especially for similarities and differences compared to that in cuprate superconductors. In contrast to cuprates, although earlier magnetization measurement reveals a Curie-Weiss-like behavior in undoped infinite-layer nickelates, there is no magnetic ordering observed by elastic neutron scattering down to liquid helium temperature. Until now, the nature of the magnetic ground state in undoped infinite-layer nickelates was still elusive. Here, we perform a nuclear magnetic resonance (NMR) experiment through ^{139}La nuclei to study the intrinsic spin susceptibility of infinite-layer LaNiO_{2}. First, the signature for magnetic ordering or freezing is absent in the ^{139}La NMR spectrum down to 0.24 K, which unambiguously confirms a paramagnetic ground state in LaNiO_{2}. Second, a pseudogaplike behavior instead of Curie-Weiss-like behavior is observed in both the temperature-dependent Knight shift and nuclear spin-lattice relaxation rate (1/T_{1}), which is widely observed in both underdoped cuprates and iron-based superconductors. Furthermore, the scaling behavior between the Knight shift and 1/T_{1}T has also been discussed. Finally, the present results imply a considerable exchange interaction in infinite-layer nickelates, which sets a strong constraint for the proposed theoretical models.
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Affiliation(s)
- D Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Y B Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Y Fu
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
| | - L Wang
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - X F Zhou
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - H Cheng
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - J Li
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - D W Song
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - S J Li
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - B L Kang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - L X Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - L P Nie
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Z M Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - M Shan
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - F H Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - J J Ying
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - S M Wang
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - J W Mei
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
| | - T Wu
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - X H Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Kang BL, Shi MZ, Li SJ, Wang HH, Zhang Q, Zhao D, Li J, Song DW, Zheng LX, Nie LP, Wu T, Chen XH. Preformed Cooper Pairs in Layered FeSe-Based Superconductors. Phys Rev Lett 2020; 125:097003. [PMID: 32915588 DOI: 10.1103/physrevlett.125.097003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 06/06/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Superconductivity arises from two distinct quantum phenomena: electron pairing and long-range phase coherence. In conventional superconductors, the two quantum phenomena generally take place simultaneously, while in the underdoped high- T_{c} cuprate superconductors, the electron pairing occurs at higher temperature than the long-range phase coherence. Recently, whether electron pairing is also prior to long-range phase coherence in single-layer FeSe film on SrTiO_{3} substrate is under debate. Here, by measuring Knight shift and nuclear spin-lattice relaxation rate, we unambiguously reveal a pseudogap behavior below T_{p}∼60 K in two kinds of layered FeSe-based superconductors with quasi2D nature. In the pseudogap regime, a weak diamagnetic signal and a remarkable Nernst effect are also observed, which indicates that the observed pseudogap behavior is related to superconducting fluctuations. These works confirm that strong phase fluctuation is an important character in the 2D iron-based superconductors as widely observed in high-T_{c} cuprate superconductors.
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Affiliation(s)
- B L Kang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - M Z Shi
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - S J Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - H H Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Q Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - D Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - J Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - D W Song
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - L X Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - L P Nie
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - T Wu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - X H Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Zou J, Song DW, Niu JJ, Shi JW, Yang HL. Standardized out-patient diagnosis and treatment process for osteoporosis clinics during the COVID-19 pandemic. Eur Rev Med Pharmacol Sci 2020; 24:5778-5782. [PMID: 32495915 DOI: 10.26355/eurrev_202005_21371] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Since the end of 2019, China and other regions around the world have been facing a pandemic of novel coronavirus pneumonia (COVID-19). The virus is highly transmissible, and the human population is generally susceptible. Most patients with osteoporosis are postmenopausal women or elderly people with hypoimmunity, so the osteoporosis clinic has become a new hotspot for corona virus infection. During the COVID-19 pandemic, it is necessary to establish standardized out-patient protocols to provide safe and effective treatment for osteoporosis patients and medical staff. In an osteoporosis clinic, we advocate the following suggestions to prevent and control osteoporosis during the pandemic period: (1) specialized diagnosis and treatment techniques for osteoporosis patients in the outpatient care, including enhancing the prevention for outpatient medical staff, strengthening awareness of COVID-19 prevention, strictly screening outpatients with COVID-19 infection, and insistent administration of anti-osteoporosis drugs during outbreaks; (2) home prevention for osteoporosis patients including keeping windows open, exposing them to sunlight, supplementing them with enough protein, exercising regularly, and administrating calcium supplements; and (3) simplifying the follow-up and evaluation of osteoporosis using online platforms.
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Affiliation(s)
- J Zou
- Department of Orthopedics, the First Affiliated Hospital of Soochow University, Suzhou City, Jiangsu Province, China.
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Song J, Shao J, Qi HH, Song DW, Zhu W. Risk factors for respiratory failure with tetraplegia after acute traumatic cervical spinal cord injury. Eur Rev Med Pharmacol Sci 2015; 19:9-14. [PMID: 25635969] [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: 06/04/2023]
Abstract
OBJECTIVE To analyze risk factors for respiratory failure with tetraplegia after acute traumatic cervical spinal cord injury (CSCI). PATIENTS AND METHODS Total 180 tetraplegia cases after acute traumatic CSCI treated in Shanghai Changzheng Hospital from 2001 to 2011 were reviewed retrospectively and the frequency of respiratory failure in these patients were analyzed against the factors including age, gender, cause of injury, level/severity of injury, high-dose methylprednisolone (MP) therapy, and surgery intervention, using Chi-square test to look into the correlations of the prevalence of respiratory failure to those factors. RESULTS Of the 180 tetraplegia with acute traumatic CSCI, 29 patients (16.11%) developed respiratory failure. The factors, including age, level and severity of injury, high-dose MP therapy, and surgery intervention, were found to significantly correlate with the appearance of respiratory failure in tetraplegia after acute traumatic CSCI (p < 0.05), while no significant correlation was found between the other factors: gender and cause of injury and the frequency of respiratory failure. CONCLUSIONS Age, level/severity of injury, high-dose MP therapy, and surgery intervention are the four major relevant factors of respiratory failure in patients with acute traumatic CSCI. The appropriate and timing treatments involving high-dose MP therapy and surgical decompression and reconstruction can substantially increase the rates of clinical improvements and reduce the frequency of respiratory failure.
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Affiliation(s)
- J Song
- Department of Orthopedics, Shanghai Changzheng Hospital, Second Military Medical University of China, Shanghai, People's Republic of China.
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Oh SH, Lee MY, Song DW. Synthesis of recombinant blood coagulation factor VIII (FVIII) heavy and light chains and reconstitution of active form of FVIII. Exp Mol Med 1999; 31:95-100. [PMID: 10410309 DOI: 10.1038/emm.1999.16] [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: 11/09/2022] Open
Abstract
FVIII is synthesized as a single chain precursor of approximately 280 kD with the domain structure of A1-A2-B-A3-C1-C2 and it circulates as a series of metal ion-linked heterodimers that result from cleavages at B-A3 junction as well as additional cleavages within B domain. Factor VIII is converted to its active form, factor VIIIa, upon proteolytic cleavages by thrombin and is a heterotrimer composed of the A1, A2, and A3-C1-C2 subunits. A1 subunits of factor VIIIa terminates with 36 residue segment (Met337-Arg372) rich in acidic residues. This segment is removed after cleavages at Arg336 by activated protein C, which results in inactivation of the cofactor. In the present study, site-directed mutagenesis of FVIII at Arg336 to Gln336 was performed in order to produce an inactivation resistant mutant rFVIII (rFVIIIm) with an extended physiological stability. A recombinant mutant heavy chain of FVIII (rFVIII-Hm; Arg336 to Gln336) and wild-type light chain of FVIII (rFVIII-L) were expressed in Baculovirus-insect cell (Sf9) system, and a biologically active recombinant mutant FVIII (rFVIIIm) was reconstituted from rFVIII-Hm and rFVIII-L in the FVIII-depleted human plasma containing 40 mM CaCl2. The rFVIIIm exhibited cofactor activity of FVIIIa (2.85 x 10(-2) units/mg protein) that sustained the high level activity during in vitro incubation at 37 degrees C for 24 h, while the cofactor activity of normal plasma was declined steadily for the period. These results indicate that rFVIIIm (Arg336 to Gln336) expressed in Baculovirus-insect cell system is inactivation resistant in the plasma coagulation milieu and may be useful for the treatment of hemophilia A.
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Affiliation(s)
- S H Oh
- Department of Biochemistry and Molecular Biology, College of Medicine, Yonsei University, Seoul, Korea.
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