Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its goo...Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.展开更多
Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical...Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical strength and physiological functions of bone.The native structures of organic components and especially the mutual interactions between different components are important questions to be addressed.Among different analytical techniques,solid-state nuclear magnetic resonance(SSNMR)spectroscopy is a powerful tool to reveal the chemical and interactional information at an atomic level.Recent advancements of SSNMR technology and experimental protocols have brought great advances in understanding the molecular details in native bones.In this review,we summarize the progresses on the SSNMR studies of various organic components in the bone matrix.In the first part,we review the studies on collagen from four different aspects:(1)waterassociated molecular dynamics;(2)the intrahelical/interhelical interactions in collagen residues;(3)the interactions between collagen and citrate;and(4)the cross-linking between collagen and inorganic surface.In the second part,we review the studies on the non-protein biomolecules including sugar species,citrate,lipids,and nucleic acids.In the end,we propose an outlook of future directions for SSNMR investigations on bones.展开更多
Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclea...Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclear magnetic resonance(NMR) spectroscopy coupled with Raman and X-ray diffraction(XRD) techniques are employed to study the reaction mechanism in a soft carbon quantitatively.It is revealed that the insertion of potassium ions into the soft carbon firstly induces a transformation of the disordered region to short-range ordered stacking,involving both the pristine local unorganized and organized carbon layers.Subsequently,potassium ions intercalate into the rearranged carbon structure,finally producing the nano-sized KC_(8).Moreover,a remarkable c apacity of 322 mAh·g^(-1) with a low mid potassiation voltage of <0.3 V is present for the prepared soft carbon,which is on account of the underlying potassium storage sites,including the disordered stacking carbon as a main component of the soft carbon.These results suggest that regulating the disordered stacking region in the turbostratic structure of soft carbon is a critical issue for further improving the potassium storage performance.展开更多
We describe a home-made dynamic nuclear polarizatioD (DNP) spectrometer at a fieldof 1.94 T, corresponding to Larmor frequencies 83 MHz and 54 GHz for proton and electron,respectively. Its NMR part is a modified Bruke...We describe a home-made dynamic nuclear polarizatioD (DNP) spectrometer at a fieldof 1.94 T, corresponding to Larmor frequencies 83 MHz and 54 GHz for proton and electron,respectively. Its NMR part is a modified Bruker WP--80SY spectrometer. A 6--mm EIO (ex-tended interaction oscillator) Klystron D3070, with a maximum output power of 30W in cwmode, served as the microwave source of ESR. In ~1H and ^(13)C DNP and DNP--CP (crosspolarization) experiments the probe consisted of a horn-antenna, a movable reflector and adouble-tuned circuit for ~1H and ^(13)C. The proton and carbon NMR signals were enhanced byone to two orders of magnitude for typical samples. Some results are presented in thispaper.展开更多
We have developed an open-source cross-platform software toolkit entitled ACCEPT-NMR (Automated Crystal Contact Extrapolation/Prediction Toolkit for NMR) as a helpful tool to automate many of the complex tasks require...We have developed an open-source cross-platform software toolkit entitled ACCEPT-NMR (Automated Crystal Contact Extrapolation/Prediction Toolkit for NMR) as a helpful tool to automate many of the complex tasks required to find and visualize crystal contacts in structures of biomolecules and biomolecular assemblies. This toolkit provides many powerful features geared toward NMR spectroscopy and related disciplines, such as isotopic labeling, advanced visualization options, and reporting tools. Using this software, we have undertaken a survey of available chemical shift data in the literature and deposited in the BMRB, and show that the mere presence of one or more crystal contacts to a residue confers an approximately 65% likelihood of significant chemical shift perturbations (relative to solution NMR chemical shifts). The presence of each additional crystal contact subsequently increases this probability, resulting in predictive accuracies in excess of 80% in many cases. Conversely, the presence of a significant experimental chemical shift perturbation indicates a >60% likelihood of finding one or more crystal contacts to a particular residue. Pinpointing sites likely to experience large CSPs is critical to mapping solution NMR chemical shifts onto solid-state NMR data as a basis for preliminary assignments, and can thus simplify the assignment process for complex biomolecules. Mapping observed CSPs onto the molecular structure, on the other hand, can indicate the presence of crystal interfaces where no crystal structure is available. Finally, by detecting sites critical to intermolecular interfaces, ACCEPT-NMR can help guide experimental approaches (e.g. isotopic labeling schemes) to detect and probe specific inter-subunit interactions.展开更多
Metal–organic frameworks(MOFs)are being investigated as the potential materials for future drug delivery and gene therapy systems thanks to their tunable functionality and biocompatibility.However,the structure of MO...Metal–organic frameworks(MOFs)are being investigated as the potential materials for future drug delivery and gene therapy systems thanks to their tunable functionality and biocompatibility.However,the structure of MOFs could be altered in a biological environment or in a buffer solution.It is of great importance to evaluate the stability of MOFs and understand the degradation processes for the sake of the biomedical applications.In this work,we investigate the stability of UiO-66,a generally-perceived stable MOF,in different amino acid solutions.We find that UiO-66 loses crystallinity in relatively mild basic conditions(when pH≥9)in the presence of amino acids.The instability is more pronounced in the lysine and arginine solutions which have stronger basicity.It can be attributed to the accelerated ligand exchange of UiO-66 under basic conditions.With a combination of techniques,we show that the amino acids can replace the organic linkers and form zirconium-amino acid complexes.Our research reveals one possible mechanism of MOF degradation in biological environment,yet such degradability could be also an important designable property for MOFs in biomedical applications.展开更多
基金supported by the National Natural Science Foundation of China(No.21974007).
文摘Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.
基金supported by the National Natural Science Foundation of China(Nos.21922410,22072133,and 22275159)Zhejiang Provincial Natural Science Foundation(No.LR19B050001)Zhejiang Provincial Natural Science Foundation(No.LQ20H170002).
文摘Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical strength and physiological functions of bone.The native structures of organic components and especially the mutual interactions between different components are important questions to be addressed.Among different analytical techniques,solid-state nuclear magnetic resonance(SSNMR)spectroscopy is a powerful tool to reveal the chemical and interactional information at an atomic level.Recent advancements of SSNMR technology and experimental protocols have brought great advances in understanding the molecular details in native bones.In this review,we summarize the progresses on the SSNMR studies of various organic components in the bone matrix.In the first part,we review the studies on collagen from four different aspects:(1)waterassociated molecular dynamics;(2)the intrahelical/interhelical interactions in collagen residues;(3)the interactions between collagen and citrate;and(4)the cross-linking between collagen and inorganic surface.In the second part,we review the studies on the non-protein biomolecules including sugar species,citrate,lipids,and nucleic acids.In the end,we propose an outlook of future directions for SSNMR investigations on bones.
基金financially supported by the National Nature Science Foundation of China (Nos.21905314, 21825202,21733012,92045302 and 21603231)Newton Advanced Fellowships (No.NAF/R2/180603)+1 种基金"Scientist Studio Funding" from Tianmu Lake Institute of Advanced Energy Storage Technologies Co.,Ltdthe Science and Technology Service Network Initiative from Chinese Academy of Science (No.STS 2020T3022)。
文摘Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclear magnetic resonance(NMR) spectroscopy coupled with Raman and X-ray diffraction(XRD) techniques are employed to study the reaction mechanism in a soft carbon quantitatively.It is revealed that the insertion of potassium ions into the soft carbon firstly induces a transformation of the disordered region to short-range ordered stacking,involving both the pristine local unorganized and organized carbon layers.Subsequently,potassium ions intercalate into the rearranged carbon structure,finally producing the nano-sized KC_(8).Moreover,a remarkable c apacity of 322 mAh·g^(-1) with a low mid potassiation voltage of <0.3 V is present for the prepared soft carbon,which is on account of the underlying potassium storage sites,including the disordered stacking carbon as a main component of the soft carbon.These results suggest that regulating the disordered stacking region in the turbostratic structure of soft carbon is a critical issue for further improving the potassium storage performance.
基金Project supported by the National Natural Science Foundation of China.
文摘We describe a home-made dynamic nuclear polarizatioD (DNP) spectrometer at a fieldof 1.94 T, corresponding to Larmor frequencies 83 MHz and 54 GHz for proton and electron,respectively. Its NMR part is a modified Bruker WP--80SY spectrometer. A 6--mm EIO (ex-tended interaction oscillator) Klystron D3070, with a maximum output power of 30W in cwmode, served as the microwave source of ESR. In ~1H and ^(13)C DNP and DNP--CP (crosspolarization) experiments the probe consisted of a horn-antenna, a movable reflector and adouble-tuned circuit for ~1H and ^(13)C. The proton and carbon NMR signals were enhanced byone to two orders of magnitude for typical samples. Some results are presented in thispaper.
文摘We have developed an open-source cross-platform software toolkit entitled ACCEPT-NMR (Automated Crystal Contact Extrapolation/Prediction Toolkit for NMR) as a helpful tool to automate many of the complex tasks required to find and visualize crystal contacts in structures of biomolecules and biomolecular assemblies. This toolkit provides many powerful features geared toward NMR spectroscopy and related disciplines, such as isotopic labeling, advanced visualization options, and reporting tools. Using this software, we have undertaken a survey of available chemical shift data in the literature and deposited in the BMRB, and show that the mere presence of one or more crystal contacts to a residue confers an approximately 65% likelihood of significant chemical shift perturbations (relative to solution NMR chemical shifts). The presence of each additional crystal contact subsequently increases this probability, resulting in predictive accuracies in excess of 80% in many cases. Conversely, the presence of a significant experimental chemical shift perturbation indicates a >60% likelihood of finding one or more crystal contacts to a particular residue. Pinpointing sites likely to experience large CSPs is critical to mapping solution NMR chemical shifts onto solid-state NMR data as a basis for preliminary assignments, and can thus simplify the assignment process for complex biomolecules. Mapping observed CSPs onto the molecular structure, on the other hand, can indicate the presence of crystal interfaces where no crystal structure is available. Finally, by detecting sites critical to intermolecular interfaces, ACCEPT-NMR can help guide experimental approaches (e.g. isotopic labeling schemes) to detect and probe specific inter-subunit interactions.
基金supported by the National Natural Science Foundation of China(Nos.21922410,22072133,and 21673206)Zhejiang Provincial Natural Science Foundation(No.LR19B050001)the Leading Innovation and Entrepreneurship Team of Zhejiang Province(No.2020R01003).
文摘Metal–organic frameworks(MOFs)are being investigated as the potential materials for future drug delivery and gene therapy systems thanks to their tunable functionality and biocompatibility.However,the structure of MOFs could be altered in a biological environment or in a buffer solution.It is of great importance to evaluate the stability of MOFs and understand the degradation processes for the sake of the biomedical applications.In this work,we investigate the stability of UiO-66,a generally-perceived stable MOF,in different amino acid solutions.We find that UiO-66 loses crystallinity in relatively mild basic conditions(when pH≥9)in the presence of amino acids.The instability is more pronounced in the lysine and arginine solutions which have stronger basicity.It can be attributed to the accelerated ligand exchange of UiO-66 under basic conditions.With a combination of techniques,we show that the amino acids can replace the organic linkers and form zirconium-amino acid complexes.Our research reveals one possible mechanism of MOF degradation in biological environment,yet such degradability could be also an important designable property for MOFs in biomedical applications.
