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Chinese Physics B 2014年第6期23卷 158-164页

作者：柯汉平陈浩林雁勤韦芝良蔡淑惠张志勇陈忠 Department of Electronic Science Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance Xiamen University

In many cases, high-resolution nuclear magnetic resonance （NMR） spectra are virtually impossible to obtain by con- ventional nuclear magnetic resonance methods because of inhomogeneity of magnetic field and inherent heterogeneity of sample. Although conventional intramolecular zero-quantum coherence （ZQC） can be used to obtain high-resolution spectrum in inhomogeneous field, the acquisition takes rather long time. In this paper, a spatially encoded intramolecular ZQC technique is proposed to fast acquire high-resolution NMR spectrum in inhomogeneous field. For the first time, the gradient-driven decoding technique is employed to selectively acquire intramolecular ZQC signals. Theoretical analyses and experimental observations demonstrate that high-resolution NMR spectral information can be retrieved within several scans even when the field inhomogeneity is severe enough to erase most spectral information. This work provides a new way to enhance the acquisition efficiency of high-resolution intramolecular ZQC spectroscopy in inhomogeneous fields.

关键词： nuclear magnetic resonance intramolecular zero-quantum coherence inhomogeneous magneticfields spatial encoding

Entanglement of a two-qubit anisotropic Heisenberg X Y Z chain in nonuniform magnetic fields with intrinsic decoherence

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Chinese Physics B 2008年第2期17卷 456-461页

作者：徐晓波刘金明于鹏飞 Key Laboratory of Optical and magnetic resonance Spectroscopy Department of PhysicsEast China Normal University

Taking the intrinsic decoherence effect into account, this paper investigates the entanglement of a two-qubit anisotropic Heisenberg XYZ model in the presence of nonuniform external magnetic fields by employing the concurrence as entanglement measure. It is found that both the intrinsic decoherence and the anisotropy of the system give a significant suppression to the entanglement. Moreover it finds that the initial state of the system plays an important role in the time evolution of the entanglement, which means that the entanglement of the system is independent of the nonuniformity and uniformity of the magnetic field when the system is in the initial state ｜ψ （0）） = ｜00） and [ψ′ （0）） = m ｜01）＋ n ｜10）, respectively.

关键词： Heisenberg XYZ chain concurrence magnetic field intrinsic decoherence

Excited-state Intramolecular Proton Transfer Mechanisms of Thiazole-based Chemosensor: a TD-DFT Study

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Chinese Journal of Structural Chemistry 2020年第11期39卷 1933-1940页

作者： CAO Hu LIU Gai-Mei CAI Jia WANG Yan School of Chemistry and Environmental Engineering Hubei Minzu UniversityEnshi 445000China Key Laboratory of magnetic resonance in Biological Systems National Center for Magnetic Resonance in WuhanState Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

The excited-state intramolecular proton transfer(ESIPT) mechanisms of 2-(2-hydroxyphenyl)-4-phenylthiazole(HPT) and 2-(5-bromo-2-hydroxyphenyl)-4-phenylthiazole(BrHPT) have been systematically investigated by density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods, approaching along with the polarizable continuum model(PCM). The calculated primary bond lengths and bond angles demonstrate that HPT and BrHPT can form intramolecular hydrogen bonds in the ground state(S0), which can be significantly strengthened in the first excited state(S1). Our calculated results well reproduce the experimental absorption and emission spectra. Upon addition of F-, the proton can move close to F-and the hydroxy moieties are deprotonated, which cause a red-shift in absorption and a new emission peak in fluorescence emission with the disappearance of the dual fluorescence emission. The calculated Mulliken’s charge distribution and frontier molecular orbitals further demonstrate that the ESIPT processes are more likely to occur in the S1 state. The constructed potential energy curves of the S0 and S1 states confirm that the proton transfer processes are hard to occur in the S0 state due to the high energy barriers. Moreover, much lower energy barriers are found in the S1 state, which proves that the ESIPT processes are more likely to take place in the S1 state. In addition, compound with electron withdrawing(-Br) group might result in much stronger intramolecular hydrogen bond and owns lower energy barrier, which can facilitate the ESIPT processes.

关键词： density functional theory ESIPT 2-(2-hydroxy-phenyl)-4-phenylthiazole potential energy curves

Computational Insights into the Excited State Intramolecular Proton Transfer Reactions in Ortho-hydroxylated Oxazolines

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Chinese Journal of Structural Chemistry 2021年第5期40卷 540-548,527页

作者： LIU Gai-Mei MA Wei-Jia WANG Yan YANG Yan SONG Xin-Jian School of Chemistry and Environmental Engineering Hubei Minzu UniversityEnshi 445000China Key Laboratory of magnetic resonance in Biological Systems National Center for Magnetic Resonance in WuhanState Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

Excited-state intramolecular proton transfer(ESIPT) reactions of three ortho-hydroxylated oxazolines, 2-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-phenol(DDOP), 4-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-[1,1?-biphenyl]-3-ol(DDOP-C_(6)H_(5)) and 4-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)-3-hydroxy-benzonitrile(DDOP-CN), have been systematically explored by density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods. Two stable configurations(enol and keto forms) are found in the ground states(S_(0)) for all the compounds while the enol form only exists in the first excited states(S_(1)) for the compound modified with electron donating group(-C_(6)H_(5)). In addition, the calculated absorption and emission spectra of the compounds are in good agreements with the experiments. Infrared vibrational spectra at the hydrogen bond groups demonstrate that the intramolecular hydrogen bond O(1)-H(2)···N(3) in DDOP-C_(6)H_(5) is strengthened in the S_(1) states, while the frontier molecular orbitals further reveal that the ESIPT reactions are more likely to occur in the S_(1) states for all the compounds. Besides, the proton transfer potential energy curves show that the enol forms can barely convert into keto forms in the S_(0) states because of the high energy barriers. Meanwhile, intramolecular proton transfer of all the compounds could occur in S_(1) states. The ESIPT reactions of the ortho-hydroxylated oxazolines are barrierless processes for unsubstituted DDOP and electron withdrawing substituted DDOP-CN, while the electron donating substituted DDOP-C_(6)H_(5) has a small barrier, so the electron donating is unfavorable to the ESIPT reactions of ortho-hydroxylated oxazolines.

关键词： excited-state intramolecular proton transfer electron donating group ortho-hydroxylated oxazolines potential energy curves

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用于常见疾病成像的纳米材料造影剂

Science China Materials 2024年第4期67卷 1288-1291页

作者：邢洁李子厚姚俊列吴爱国 Ningbo Key Laboratory of Biomedical imaging Probe Materials and Technology Zhejiang International Cooperation Base of Biomedical Materials Technology and Application Chinese Academy of Sciences (CAS) Key Laboratory of Magnetic Materials and Devices Ningbo Cixi Institute of Biomedical Engineering Zhejiang Engineering Research Center for Biomedical Materials Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Advanced Energy Science and Technology Guangdong Laboratory

生物医学精准诊断对于疾病的有效治疗十分重要.纳米基成像造影剂具有灵敏度高、特异性强、生物相容性好等特点,在生物医学成像诊断中具有巨大的临床转化潜力.目前,尽管研究者们构筑了大量的纳米基探针材料作为疾病诊断造影剂,但纳米材... 详细信息

生物医学精准诊断对于疾病的有效治疗十分重要.纳米基成像造影剂具有灵敏度高、特异性强、生物相容性好等特点,在生物医学成像诊断中具有巨大的临床转化潜力.目前,尽管研究者们构筑了大量的纳米基探针材料作为疾病诊断造影剂,但纳米材料造影剂在临床转化方面仍然面临极大的挑战.这里我们主要概述了不同生物医学成像类型的纳米基造影剂所面临的问题,并针对这些难题提出了应对方案和未来的研究重点,最后对纳米基造影剂的临床转化前景进行了展望.

关键词：造影剂生物医学成像疾病诊断应对方案生物相容性纳米材料临床转化有效治疗

Cognitive dysfunction in schizophrenia patients caused by downregulation of γ-aminobutyric acid receptor subunits

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World Journal of Psychiatry 2024年第6期14卷 784-793页

作者： Xi Chen Ya-Nan Zhou Xiao-Zi Lu Ren-Jiao Li Yi-Fan Xiong Xia Sheng Wei-Wei Zhu Department of Child and Adolescent Psychiatric Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Psychiatry Qingdao Mental Health CenterQingdao 266034Shandong ProvinceChina Department of Psychiatry Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Sleep Disorders and Neurosis Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina

BACKGROUND The expression pattern of gamma aminobutyric acid(GABA)receptor subunits are commonly altered in patients with schizophrenia,which may lead to nerve excitation/inhibition problems,affecting cognition,emotion,and *** To explore GABA receptor expression and its relationship with schizophrenia and to provide insights into more effective *** This case-control study enrolled 126 patients with schizophrenia treated at our hospital and 126 healthy volunteers who underwent physical examinations at our hospital during the same *** expression levels of the GABA receptor subunits were detected using 1H-magnetic resonance *** recognized cognitive battery tool,the MATRICS Consensus Cognitive Battery,was used to evaluate the scores for various dimensions of cognitive *** correlation between GABA receptor subunit downregulation and schizophrenia was also *** Significant differences in GABA receptor subunit levels were found between the case and control groups(P0.05).CONCLUSION Downregulation of the GABA receptor subunits is positively correlated with *** other words,when GABA receptor subunits are downregulated in patients,cognitive impairment becomes more severe.

关键词： Cognitive function Schizophrenia Downregulation Gamma-aminobutyric acid receptor subunits Correlation

Neuronal Network Dissection with Neurotropic Virus Tracing

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Neuroscience Bulletin 2020年第3期36卷 199-201页

作者： Xiaoping Rao Jie Wang Center of brain Science State Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsNational Center for Magnetic Resonance in WuhanKey Laboratory of Magnetic Resonance in Biological SystemsWuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China The Second Hospital of Shijiazhuang Shijiazhuang 050051China

The brain is a marvel of biological evolution,a highly complex organ including hundreds of different types of about 100 billion *** the structure and function of the brain is one of the most challenging scientific questions in the 21st ***,the structure of neural circuits and the mechanisms of neuronal information processing related to brain function are still poorly understood[1].A neural circuit is composed of a large number of synaptically connected neurons of different types and *** is the structural basis for the execution of various functions,such as perception,emotion,memory,and imagination,as well as other *** the structure of neural circuits is the basic premise for understanding the mechanism of information processing in the brain[2].

关键词： neural hundreds function

Multimodality magnetic resonance imaging in hepatic encephalopathy: An update

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World Journal of Gastroenterology 2014年第32期20卷 11262-11272页

作者： Xiao-Dong Zhang Long-Jiang Zhang Sheng-Yong Wu Guang-Ming lu Department of Medical imaging Jinling Hospital Nanjing Clinical School Southern Medical University Department of Medical imaging Jinling Hospital Medical School of Nanjing University Department of Radiology Medical Imaging Institute of Tianjin

Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE. Hyperammonaemia and neuroinflammation are two main underlying factors which contribute to the neurological alterations in HE. Both structural and functional impairments are found in the white mater and grey mater involved in HE. Although the investigations into HE pathophysiological mechanism are enormous, the exact pathophysiological causes underlying HE remain controversial. Multimodality magnetic resonance imaging(MRI) plays an important role in helping to understand the pathological process of HE. This paper reviews the up-to-date multimodality MRI methods and predominant findings in HE patients with a highlight ofthe increasingly important role of blood oxygen level dependent functional MRI.

关键词： Hepatic encephalopathy magnetic resonance imaging magnetic resonance spectroscopy Diffusion weighted imaging Default-mode network Blood oxygenation level dependent functional magnetic resonance imaging

A flexible ultra-broadband multi-layered absorber working at 2 GHz-40 GHz printed by resistive ink

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Chinese Physics B 2024年第2期33卷 329-333页

作者：汪涛闫玉伦陈巩华李迎胡俊毛剑波 School of Microelectronics Hefei University of TechnologyHefei 230601China Special Display and imaging Technology Innovation Center of Anhui Province Academy of Photoelectric TechnologyHefei University of TechnologyHefei 230027China

A flexible extra broadband metamaterial absorber(MMA)stacked with five layers working at 2 GHz–40 GHz is *** layer is composed of polyvinyl chloride(PVC),polyimide(PI),and a frequency selective surface(FSS),which is printed on PI using conductive *** investigate this absorber,both one-dimensional analogous circuit analysis and three-dimensional full-wave simulation based on a physical model are *** crucial electromagnetic properties,such as absorption,effective impedance,complex permittivity and permeability,electric current distribution and magnetic field distribution at resonant peak points,are studied in *** shows that the working frequency of this absorber covers entire S,C,X,Ku,K and Ka bands with a minimum thickness of 0.098λ_(max)(λ_(max) is the maximum wavelength in the absorption band),and the fractional bandwidth(FBW)reaches 181.1%.Moreover,the reflection coefficient is less than-10 dB at 1.998 GHz–40.056 GHz at normal incidence,and the absorptivity of the plane wave is greater than 80%when the incident angle is smaller than 50°.Furthermore,the proposed absorber is experimentally validated,and the experimental results show good agreement with the simulation results,which demonstrates the potential applicability of this absorber at 2 GHz–40 GHz.

关键词： extra broadband physical model flexible metamaterial absorber multi-layer frequency selective surface

Recent advances in solid-state NMR of zeolite catalysts

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National Science Review 2022年第9期9卷 79-101页

作者： Weiyu Wang Jun Xu Feng Deng National Center for magnetic resonance in Wuhan State Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of Sciences University of Chinese Academy of Sciences

Zeolites are important inorganic crystalline microporous materials with a broad range of applications in the areas of catalysis, ion exchange, and adsorption/separations. Solid-state nuclear magnetic resonance(NMR) spectroscopy has proven to be a powerful tool in the study of zeolites and relevant catalytic reactions because of its advantage in providing atomic-level insights into molecular structure and dynamic behavior. In this review, we provide a brief discussion on the recent progress in exploring framework structures, catalytically active sites and intermolecular interactions in zeolites and metal-containing ones by using various solid-state NMR methods. Advances in the mechanistic understanding of zeolite-catalysed reactions including methanol and ethanol conversions are presented as selected examples. Finally, we discuss the prospect of the solid-state NMR technique for its application in zeolites.

关键词： solid-state NMR zeolites characterization active sites reaction mechanism