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Zhang W, Ji Q, Zhang G, Gu Z, Wang H, Hu C, Liu H, Ren ZJ, Qu J. Pumping and sliding of droplets steered by a hydrogel pattern for atmospheric water harvesting. Natl Sci Rev 2023; 10:nwad334. [PMID: 38299118 PMCID: PMC10829482 DOI: 10.1093/nsr/nwad334] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 02/02/2024] Open
Abstract
Atmospheric water harvesting is an emerging strategy for decentralized and potable water supplies. However, water nucleation and microdroplet coalescence on condensing surfaces often result in surface flooding owing to the lack of a sufficient directional driving force for shedding. Herein, inspired by the fascinating properties of lizards and catfish, we present a condensing surface with engineered hydrogel patterns that enable rapid and sustainable water harvesting through the directional pumping and drag-reduced sliding of water droplets. The movement of microscale condensed droplets is synergistically driven by the surface energy gradient and difference in Laplace pressure induced by the arch hydrogel patterns. Meanwhile, the superhydrophilic hydrogel surface can strongly bond inner-layer water molecules to form a lubricant film that reduces drag and facilitates the sliding of droplets off the condensing surface. Thus, this strategy is promising for various water purification techniques based on liquid-vapor phase-change processes.
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Affiliation(s)
- Wei Zhang
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qinghua Ji
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Gong Zhang
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhenao Gu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haozhi Wang
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350207, China
- Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Chengzhi Hu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhiyong Jason Ren
- Department of Civil and Environmental Engineering and Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ 08544, USA
| | - Jiuhui Qu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Shultz MJ, Bisson P, Wang J, Marmolejos J, Davies RG, Gubbins E, Xiong Z. High phase resolution: Probing interactions in complex interfaces with sum frequency generation. Biointerphases 2023; 18:058502. [PMID: 37902617 DOI: 10.1116/6.0002963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/20/2023] [Indexed: 10/31/2023] Open
Abstract
An often-quoted statement attributed to Wolfgang Pauli is that God made the bulk, but the surface was invented by the devil. Although humorous, the statement really reflects frustration in developing a detailed picture of a surface. In the last several decades, that frustration has begun to abate with numerous techniques providing clues to interactions and reactions at surfaces. Often these techniques require considerable prior knowledge. Complex mixtures on irregular or soft surfaces-complex interfaces-thus represent the last frontier. Two optical techniques: sum frequency generation (SFG) and second harmonic generation (SHG) are beginning to lift the veil on complex interfaces. Of these techniques, SFG with one excitation in the infrared has the potential to provide exquisite molecular- and moiety-specific vibrational data. This Perspective is intended both to aid newcomers in gaining traction in this field and to demonstrate the impact of high-phase resolution. It starts with a basic description of light-induced surface polarization that is at the heart of SFG. The sum frequency is generated when the input fields are sufficiently intense that the interaction is nonlinear. This nonlinearity represents a challenge for disentangling data to reveal the molecular-level picture. Three, high-phase-resolution methods that reveal interactions at the surface are described.
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Affiliation(s)
- Mary Jane Shultz
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
| | - Patrick Bisson
- Cambridge Polymer Group, Inc., 100 Trade Center Drive, Suite 200, Woburn, Massachusetts 01801
| | - Jing Wang
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
| | - Joam Marmolejos
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
| | - Rebecca G Davies
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
| | - Emma Gubbins
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
| | - Ziqing Xiong
- Laboratory for Water and Surface Studies, Tufts University, Pearson Laboratory, 62 Talbot Ave., Medford, Massachusetts 02155
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Das Mahanta D, Brown DR, Pezzotti S, Han S, Schwaab G, Shell MS, Havenith M. Local solvation structures govern the mixing thermodynamics of glycerol-water solutions. Chem Sci 2023; 14:7381-7392. [PMID: 37416713 PMCID: PMC10321518 DOI: 10.1039/d3sc00517h] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023] Open
Abstract
Glycerol is a major cryoprotective agent and is widely used to promote protein stabilization. By a combined experimental and theoretical study, we show that global thermodynamic mixing properties of glycerol and water are dictated by local solvation motifs. We identify three hydration water populations, i.e., bulk water, bound water (water hydrogen bonded to the hydrophilic groups of glycerol) and cavity wrap water (water hydrating the hydrophobic moieties). Here, we show that for glycerol experimental observables in the THz regime allow quantification of the abundance of bound water and its partial contribution to the mixing thermodynamics. Specifically, we uncover a 1 : 1 connection between the population of bound waters and the mixing enthalpy, which is further corroborated by the simulation results. Therefore, the changes in global thermodynamic quantity - mixing enthalpy - are rationalized at the molecular level in terms of changes in the local hydrophilic hydration population as a function of glycerol mole fraction in the full miscibility range. This offers opportunities to rationally design polyol water, as well as other aqueous mixtures to optimize technological applications by tuning mixing enthalpy and entropy based on spectroscopic screening.
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Affiliation(s)
- Debasish Das Mahanta
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
- Department of Physics, Technische Universität Dortmund 44227 Dortmund Germany
| | - Dennis Robinson Brown
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
| | - Simone Pezzotti
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Songi Han
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
- Department of Chemistry and Biochemistry, University of California Santa Barbara California 93106-9510 USA
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
| | - M Scott Shell
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
- Department of Physics, Technische Universität Dortmund 44227 Dortmund Germany
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4
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Mbarek F, Chérif I, Chérif A, Alonso JM, Morales I, de la Presa P, Ammar S. Insights into the Synthesis Parameters Effects on the Structural, Morphological, and Magnetic Properties of Copper Oxide Nanoparticles. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093426. [PMID: 37176307 PMCID: PMC10180341 DOI: 10.3390/ma16093426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023]
Abstract
The present study aims at the integration of the "oxalic conversion" route into "green chemistry" for the synthesis of copper oxide nanoparticles (CuO-NPs) with controllable structural, morphological, and magnetic properties. Two oxalate-containing precursors (H2C2O4.2H2O and (NH4)2C2O4.H2O) and different volume ratios of a mixed water/glycerol solvent were tested. First, the copper oxalates were synthesized and then subjected to thermal decomposition in air at 400 °C to produce the CuO powders. The purity of the samples was confirmed by X-ray powder diffraction (XRPD), and the crystallite sizes were calculated using the Scherrer method. The transmission electron microscopy (TEM) images revealed oval-shaped CuO-NPs, and the scanning electron microscopy (SEM) showed that morphological features of copper oxalate precursors and their corresponding oxides were affected by the glycerol (V/V) ratio as well as the type of C2O42- starting material. The magnetic properties of CuO-NPs were determined by measuring the temperature-dependent magnetization and the hysteresis curves at 5 and 300 K. The obtained results indicate the simultaneous coexistence of dominant antiferromagnetic and weak ferromagnetic behavior.
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Affiliation(s)
- Fatma Mbarek
- Electrochemistry, Materials and Environment Research Unit, UREME (UR17ES45), Faculty of Sciences of Gabes, University of Gabes, Gabes 6072, Tunisia
| | - Ichraf Chérif
- Electrochemistry, Materials and Environment Research Unit, UREME (UR17ES45), Faculty of Sciences of Gabes, University of Gabes, Gabes 6072, Tunisia
- Higher Institute of Education and Continuous Training of Tunis, Virtual University of Tunis, Tunis 1073, Tunisia
| | - Amira Chérif
- University of Tunis El Manar, Faculty of Sciences of Tunis, Laboratory of Materials Organization and Properties, Tunis 2092, Tunisia
| | - José María Alonso
- Institute of Applied Magnetism, Complutense University of Madrid, A6 22,500 Km, 28230 Las Rozas, Spain
- Institute of Materials Sciences of Madrid, CSIC, Sor Juana Ines de la Cruz, 28049 Madrid, Spain
| | - Irene Morales
- Institute of Applied Magnetism, Complutense University of Madrid, A6 22,500 Km, 28230 Las Rozas, Spain
| | - Patricia de la Presa
- Institute of Applied Magnetism, Complutense University of Madrid, A6 22,500 Km, 28230 Las Rozas, Spain
- Department of Material Physics, Complutense University of Madrid, Plaza de la Ciencia 1, 28040 Madrid, Spain
| | - Salah Ammar
- Electrochemistry, Materials and Environment Research Unit, UREME (UR17ES45), Faculty of Sciences of Gabes, University of Gabes, Gabes 6072, Tunisia
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5
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Marshall T, Earnden L, Marangoni AG, Laredo T, Pensini E. Cubic mesophases of self-assembled amphiphiles separate miscible solvents. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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6
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Lu W, Mackie CJ, Xu B, Head-Gordon M, Ahmed M. A Computational and Experimental View of Hydrogen Bonding in Glycerol Water Clusters. J Phys Chem A 2022; 126:1701-1710. [PMID: 35254809 DOI: 10.1021/acs.jpca.2c00659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Polyol-water clusters provide a template to probe ionization and solvation processes of paramount interest in atmospheric and interstellar chemistry. We generate glycerol water clusters in a continuous supersonic jet expansion and interrogate the neutral species with synchrotron-based tunable vacuum ultraviolet photoionization mass spectrometry. A series of glycerol fragments (m/z 44, 61, 62, and 74) clustered with water are observed. A judicious combination of backing pressure, nozzle temperature, and water vapor pressure allows for tuning the mol % of glycerol. The recorded appearance energies of the water cluster series m/z 62 and 74 are similar to that observed in pure glycerol, while the m/z 61 series shows a dependence on cluster composition. Furthermore, this series also tracks the water concentration of the beam. Theoretical calculations on neutral and ionized clusters visualize the hydrogen bond network in these water clusters and provide an assessment of the number of glycerol-glycerol, glycerol-water, and water-water hydrogen bonds in the cluster, as well as their interaction energies. This method of bond counting and interaction energy assessment explains the changes in the mass spectrum as a function of mol % and offers a glimpse of the disruption of the hydrogen bond network in glycerol-water clusters. The calculations also reveal interesting barrierless chemical processes in photoionized glycerol water clusters that are either activated or do not occur without the presence of water. Examples include spontaneous intramolecular proton transfer within glycerol to form a distonic ion, nonactivated breaking of a C-C bond, and spontaneous proton transfer from glycerol to water. These results appear relevant to radiation-induced chemical processing of alcohol-water ices in the interstellar medium.
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Affiliation(s)
- Wenchao Lu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Cameron J Mackie
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Bo Xu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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7
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Vazquez de Vasquez MG, Carter-Fenk KA, McCaslin LM, Beasley EE, Clark JB, Allen HC. Hydration and Hydrogen Bond Order of Octadecanoic Acid and Octadecanol Films on Water at 21 and 1 °C. J Phys Chem A 2021; 125:10065-10078. [PMID: 34761931 DOI: 10.1021/acs.jpca.1c06101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The temperature-dependent hydration structure of long-chain fatty acids and alcohols at air-water interfaces has great significance in the fundamental interactions underlying ice nucleation in the atmosphere. We present an integrated theoretical and experimental study of the temperature-dependent vibrational structure and electric field character of the immediate hydration shells of fatty alcohol and acid headgroups. We use a combination of surface-sensitive infrared reflection-absorption spectroscopy (IRRAS), surface potentiometry, and ab initio molecular dynamics simulations to elucidate detailed molecular structures of the octadecanoic acid and octadecanol (stearic acid and stearyl alcohol) headgroup hydration shells at room temperature and near freezing. In experiments, the alcohol at high surface concentration exhibits the largest surface potential; yet we observe a strengthening of the hydrogen-bonding for the solvating water molecules near freezing for both the alcohol and the fatty acid IRRAS experiments. Results reveal that the hydration shells for both compounds screen their polar headgroup dipole moments reducing the surface potential at low surface coverages; at higher surface coverage, the polar headgroups become dehydrated, which reduces the screening, correlating to higher observed surface potential values. Lowering the temperature promotes tighter chain packing and an increase in surface potential. IRRAS reveals that the intra- and intermolecular vibrational coupling mechanisms are highly sensitive to changes in temperature. We find that intramolecular coupling dominates the vibrational relaxation pathways for interfacial water determined by comparing the H2O and the HOD spectra. Using ab initio molecular dynamics (AIMD) calculations on cluster systems of propanol + 6H2O and propionic acid + 10H2O, a spectral decomposition scheme was used to correlate the OH stretching motion with the IRRAS spectral features, revealing the effects of intra- and intermolecular coupling on the spectra. Spectra calculated with AIMD reproduce the red shift and increase in intensity observed in experimental spectra corresponding to the OH stretching region of the first solvation shell. These findings suggest that intra- and intermolecular vibrational couplings strongly impact the OH stretching region at fatty acid and fatty alcohol water interfaces. Overall, results are consistent with ice templating behavior for both the fatty acid and the alcohol, yet the surface potential signature is strongest for the fatty alcohol. These findings develop a better understanding of the complex surface potential and spectral signatures involved in ice templating.
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Affiliation(s)
- Maria G Vazquez de Vasquez
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Kimberly A Carter-Fenk
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Laura M McCaslin
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Emma E Beasley
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Jessica B Clark
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C Allen
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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8
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Liu Y, Huang K, Zhou Y, Gou D, Shi H. Hydrogen Bonding and the Structural Properties of Glycerol-Water Mixtures with a Microwave Field: a Molecular Dynamics Study. J Phys Chem B 2021; 125:8099-8106. [PMID: 34264668 DOI: 10.1021/acs.jpcb.1c03232] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a microwave field, the dielectric properties, molecular structures, and hydrogen bonding dynamics of glycerol in its mixtures with water were determined by the molecular dynamics simulation method. The dipole-dipole correlation of glycerol is linked to the field intensity of microwaves. The results show that as the field intensity is increased, even glycerol in the second coordination shell can become correlated with each other. The structures of up to 35 glycerol molecules are observed. More than that, it was observed that lifetimes of glycerol-glycerol hydrogen bonds were prolonged, while the average hydrogen bond number was also increased. Besides, the structures in a strong microwave field mimic the weak C-H⋯O hydrogen bonds seen in high-glycerol concentration mixtures, yet the concentration is lower. These results indicate that with the assistance of the microwave field, glycerol molecules become concentrated and are more likely to establish stable interactions with others. As a consequence, the spherical clusters composed by glycerol molecules in our nanosheet synthesis experiment are easier to form.
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Affiliation(s)
- Ying Liu
- College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Kama Huang
- College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Yanping Zhou
- College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Dezhi Gou
- College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Hongxiao Shi
- College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, Sichuan, China
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9
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Weeraratna C, Amarasinghe C, Lu W, Ahmed M. A Direct Probe of the Hydrogen Bond Network in Aqueous Glycerol Aerosols. J Phys Chem Lett 2021; 12:5503-5511. [PMID: 34087076 DOI: 10.1021/acs.jpclett.1c01383] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The properties of aerosols are of paramount importance in atmospheric chemistry and human health. The hydrogen bond network of glycerol-water aerosols generated from an aqueous solution with different mixing ratios is probed directly with X-ray photoelectron spectroscopy. The carbon and oxygen X-ray spectra reveal contributions from gas and condensed phase components of the aerosol. It is shown that water suppresses glycerol evaporation up to a critical mixing ratio. A dielectric analysis using terahertz spectroscopy coupled with infrared spectroscopy of the bulk solutions provides a picture of the microscopic heterogeneity prevalent in the hydrogen bond network when combined with the photoelectron spectroscopy analysis. The hydrogen bond network is composed of three intertwined regions. At low concentrations, glycerol molecules are surrounded by water forming a solvated water network. Adding more glycerol leads to a confined water network, maximizing at 22 mol %, beyond which the aerosol resembles bulk glycerol. This microscopic view of hydrogen bonding networks holds promise in probing evaporation, diffusion dynamics, and reactivity in aqueous aerosols.
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Affiliation(s)
- Chaya Weeraratna
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Chandika Amarasinghe
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Wenchao Lu
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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10
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Habuka A, Yamada T, Nakashima S. Interactions of Glycerol, Diglycerol, and Water Studied Using Attenuated Total Reflection Infrared Spectroscopy. APPLIED SPECTROSCOPY 2020; 74:767-779. [PMID: 32223430 DOI: 10.1177/0003702820919530] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In order to examine the mixing properties of glycerol-water and diglycerol-water solutions, these solutions were measured using attenuated total reflection infrared spectroscopy. The absorbance spectra corrected for 1 µm thickness were subtracted by pure polyols for obtaining water spectra, and by pure water for polyol spectra. Both asymmetric and symmetric CH2 stretching vibration bands (around 2940, 2885 cm-1) shifted about 10 cm-1 to lower wavenumber side (redshifts) with increasing polyol concentrations, especially at higher concentrations. Redshifts of C-O-H rocking bands (around 1335 cm-1) with increasing polyol concentrations are slightly larger for diglycerol-water (10 > 6 cm-1) than glycerol-water solutions. C-O stretching bands of CHOH groups (1125 and 1112 cm-1) shift slightly but in opposite sides for glycerol and diglycerol at highest polyol concentrations (90-100 wt%). These shifts of CH2 stretching, COH rocking, and CO stretching of CHOH at higher polyol concentrations suggest interactions of outer CH2 with inner CHOH groups of surrounding polyols. The normalized band area changes with polyol concentrations could be fitted by quadratic polynomials possibly due to mixtures of different interactions between water-water, polyol-water, and polyol-polyol molecules. The OH stretching band for diglycerol 90 wt% shows three humps indicating at least three OH components: long, medium, and short H bond water molecules. Short H bond water molecules are the major component possibly between inner CHOH and outer side CH2OH groups, while the long H component might loosely bind to outer CH2OH groups.
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Affiliation(s)
- Akari Habuka
- Research and Development Center, Sakamoto Yakuhin Kogyo Co., Ltd, Osaka, Japan
| | - Takeshi Yamada
- Research and Development Center, Sakamoto Yakuhin Kogyo Co., Ltd, Osaka, Japan
| | - Satoru Nakashima
- Department of Earth and Space Science, Osaka University, Osaka, Japan
- Faculty of Environmental and Urban Engineering, Kansai University, Osaka, Japan
- Research Institute for Natural Environment, Science and Technology (RINEST), Osaka, Japan
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11
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Deng GH, Shen Y, Chen H, Chen Y, Jiang B, Wu G, Yang X, Yuan K, Zheng J. Ordered-to-Disordered Transformation of Enhanced Water Structure on Hydrophobic Surfaces in Concentrated Alcohol-Water Solutions. J Phys Chem Lett 2019; 10:7922-7928. [PMID: 31794227 DOI: 10.1021/acs.jpclett.9b03429] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effects of hydrophobic solutes on the structure of the surrounding water have been a topic of debate for almost 70 years. However, a consistent description of the physical insight into the causes of the anomalous thermodynamic properties of alcohol-water mixtures is lacking. Here we report experimental results that combined temperature-dependent linear and femtosecond infrared spectroscopy measurements to explore the water structural transformation in concentrated alcohol-water solutions. Experiments show that the enhancement of water structure arises around microhydrophobic interfaces at room temperature in the solutions. As temperature increases, this ordered water structure disappears and a surface topography-dependent new disordered water structure arises at concentrated solutions of large alcohols. The water structural transformation is dependent on not only the length of the alkyl chain but also the clustering of the alcohols. A more-ordered-than-water structure can transform into a less-ordered-than-water structure.
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Affiliation(s)
- Gang-Hua Deng
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Yuneng Shen
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
- School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China
| | - Hailong Chen
- Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Yajing Chen
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Bo Jiang
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, 457 Zhongshan Road , Dalian 116023 , China
| | - Junrong Zheng
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences , Peking University , Beijing 100871 , China
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12
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Lv T, Wang Y, Zhang S, Feng Z, Zheng J, Yang J, Liu X, Liu X, Meng C. Solid-state transformation of TMA-magadiite into zeolite omega and detailed insights into the crystallization process. Dalton Trans 2019; 48:16974-16985. [PMID: 31687705 DOI: 10.1039/c9dt02945a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we have studied the crystallization of zeolite omega by the solid-state transformation of TMA-magadiite at 100 °C for 12 h. The samples prepared at different times were subjected to XRD, SEM, IR, Raman and solid MAS NMR analyses to investigate the crystallization behaviors and changes in the medium-range structure during the synthesis process and a comprehensive mechanism was proposed. It has been demonstrated that the 5Rs and 6Rs in magadiite are partially retained in the system and participate in the growth of zeolite omega. The 4Rs were formed after heating for 4 h. The synthesis time of the zeolite omega using this method is shorter than that using the magadiite hydrothermal conversion method (about 72 h), because special composition building units, which have similarities to the structure of zeolite omega, were formed and adsorbed on the surface of the TMA-magadiite, and then provided a growth surface for the synthesis of targets. In addition, recycling the waste mother liquid produced in the preparation of the precursor was done to achieve the low cost and green synthesis. Finally, several factors influencing the reaction are discussed.
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Affiliation(s)
- Tianming Lv
- School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
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13
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Nakagawa H, Oyama T. Molecular Basis of Water Activity in Glycerol-Water Mixtures. Front Chem 2019; 7:731. [PMID: 31737605 PMCID: PMC6839025 DOI: 10.3389/fchem.2019.00731] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/14/2019] [Indexed: 12/11/2022] Open
Abstract
Water activity (Aw) is a reliable indication of the microbial growth, enzymatic activity, preservation, and quality of foods. However, a molecular basis of Aw is still under debate in multiple related disciplines. Glycerol-water mixtures can provide a variation of Aws by controlling the ratio of glycerol and water. In this study, the molecular basis of Aw was examined by using differential scanning calorimetry (DSC), attenuated total reflection Fourier-transform infrared spectroscopy (ATR-IR), and incoherent quasi-elastic neutron scattering (IQENS) based on moisture sorption isotherms of glycerol-water mixtures. Three regions were identified and classified based on DSC results. DSC showed that bulk-like water existed at Aw > ≈ 0.7 at 27°C. Hydrogen bonding related molecular vibrations were analyzed by ATR-IR, which indicated that the OH stretching in water molecules is significantly different for Aw > ≈ 0.7. Translational diffusive and/or rotational motions in time and space analyzed by IQENS appeared when Aw > ≈ 0.7, and are correlated with hydrogen bonding related local vibrational dynamics in the glycerol-water mixtures. More importantly, Aw values of glycerol-water mixtures can be explained by the hydrogen bonding network and molecular dynamics of water in the solution. We discuss the implications of Aw in the preservation of food at the molecular level.
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Affiliation(s)
- Hiroshi Nakagawa
- Hierarchical Structure Research Group, Materials Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
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14
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Wacławska M, Guza M, Ścibisz G, Fortunka M, Dec R, Puławski W, Dzwolak W. Reversible Freeze-Induced β-Sheet-to-Disorder Transition in Aggregated Homopolypeptide System. J Phys Chem B 2019; 123:9080-9086. [DOI: 10.1021/acs.jpcb.9b06097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Matylda Wacławska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
| | - Marcin Guza
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
| | - Grzegorz Ścibisz
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
| | - Mateusz Fortunka
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
| | - Robert Dec
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
| | - Wojciech Puławski
- Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37 Str., Warsaw 01-142, Poland
| | - Wojciech Dzwolak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., Warsaw 02-093, Poland
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15
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Adsorption and Decomposition of Glycerol on Pristine and Oxygen Modified Au(111) Surfaces. Top Catal 2019. [DOI: 10.1007/s11244-019-01199-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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16
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Fanetti S, Falsini N, Bartolini P, Citroni M, Lapini A, Taschin A, Bini R. Superheating and Homogeneous Melting Dynamics of Bulk Ice. J Phys Chem Lett 2019; 10:4517-4522. [PMID: 31342749 DOI: 10.1021/acs.jpclett.9b01490] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Homogeneous melting of crystals is a complex multistep process involving the formation of transient states at temperatures considerably higher than the melting point. The nature and persistence of these metastable structures are intimately connected to the melting process, and a precise definition of the temporal boundaries of these phenomena is not yet available. We set up a specifically designed experiment to probe by transient infrared absorption spectroscopy the entire dynamics, ranging from tens of picoseconds to microseconds, of superheating and melting of an ice crystal. In spite of a large excess of energy provided, only about 30% of the micrometric crystal liquefies in the first 20-25 ns because of the long persistence of the superheated metastable phase that extends for more than 100 ns. This behavior is ascribed to the population of low-energy states that trap a large amount of energy, favoring the formation of a metastable, likely plastic, ice phase.
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Affiliation(s)
- Samuele Fanetti
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
- ICCOM, Istituto di Chimica dei Composti OrganoMetallici , Via Madonna del Piano 10 , I-50019 Sesto Fiorentino , Firenze , Italy
| | - Naomi Falsini
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
| | - Paolo Bartolini
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
| | - Margherita Citroni
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
| | - Andrea Lapini
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
- INRIM, Istituto Nazionale di Ricerca Metrologica , Strada delle Cacce 91 , I-10135 Torino , Italy
| | - Andrea Taschin
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
- ENEA, Centro Ricerche Frascati , Via E. Fermi 45 , I-00044 Frascati Roma , Italy
| | - Roberto Bini
- European Laboratory for Nonlinear Spectroscopy (LENS) , via Nello Carrara 1 , 50019 Sesto Fiorentino (FI), Italy
- ICCOM, Istituto di Chimica dei Composti OrganoMetallici , Via Madonna del Piano 10 , I-50019 Sesto Fiorentino , Firenze , Italy
- Dipartimento di Chimica "Ugo Schiff" , Università di Firenze , via della Lastruccia 3 , 50019 Sesto Fiorentino (FI), Italy
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17
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Investigation of plasticizer aggregation problem in casein based biopolymer using chemical imaging. Talanta 2019; 193:128-138. [DOI: 10.1016/j.talanta.2018.09.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 11/21/2022]
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18
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Yamada T, Mizuno M. Characteristic Spectroscopic Features because of Cation-Anion Interactions Observed in the 700-950 cm -1 Range of Infrared Spectroscopy for Various Imidazolium-Based Ionic Liquids. ACS OMEGA 2018; 3:8027-8035. [PMID: 31458940 PMCID: PMC6644554 DOI: 10.1021/acsomega.8b00938] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/05/2018] [Indexed: 06/10/2023]
Abstract
The 700-950 cm-1 range in infrared spectroscopy was investigated for various imidazolium-based ionic liquids (ILs). Two main vibrational modes of the methylimidazolium cation exist in this region. At 700-800 cm-1, there is an out-of-plane +C(2)-H and +C(4,5)-H bending mode with a larger motion of +C(4,5)-H in the imidazolium ring, whereas at 800-950 cm-1, there is an out-of-plane +C(2)-H and +C(4,5)-H bending mode with a larger motion of +C(2)-H in the imidazolium ring. The molar-concentration-normalized absorbance spectrum of the former band at 700-800 cm-1, which is related to the bending mode with a large +C(4,5)-H motion in the imidazolium ring, is not particularly sensitive to the interactions with anions. The molar-concentration-normalized absorbance spectrum of the latter band at 800-950 cm-1 was nearly identical for ILs that have methylimidazolium cations with carbon chains of different lengths and the same anions. The band shape of the latter band, which is related to the bending mode with a large out-of-plane +C(2)-H bending motion, was highly sensitive to the interactions with anions and, interestingly, both blue- and red-shifted tendencies in the spectrum for each system were observed.
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Affiliation(s)
- Toshiki Yamada
- Advanced
ICT Research Institute, National Institute
of Information and Communications Technology, 588-2 Iwaoka, Kobe 651-2492, Japan
| | - Maya Mizuno
- Applied
Electromagnetic Research Institute, National
Institute of Information and Communications Technology, 4-2-1 Nukuikitamachi, Koganei, Tokyo 184-8795, Japan
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Carpenter WB, Fournier JA, Biswas R, Voth GA, Tokmakoff A. Delocalization and stretch-bend mixing of the HOH bend in liquid water. J Chem Phys 2018; 147:084503. [PMID: 28863511 DOI: 10.1063/1.4987153] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Liquid water's rich sub-picosecond vibrational dynamics arise from the interplay of different high- and low-frequency modes evolving in a strong yet fluctuating hydrogen bond network. Recent studies of the OH stretching excitations of H2O indicate that they are delocalized over several molecules, raising questions about whether the bending vibrations are similarly delocalized. In this paper, we take advantage of an improved 50 fs time-resolution and broadband infrared (IR) spectroscopy to interrogate the 2D IR lineshape and spectral dynamics of the HOH bending vibration of liquid H2O. Indications of strong bend-stretch coupling are observed in early time 2D IR spectra through a broad excited state absorption that extends from 1500 cm-1 to beyond 1900 cm-1, which corresponds to transitions from the bend to the bend overtone and OH stretching band between 3150 and 3550 cm-1. Pump-probe measurements reveal a fast 180 fs vibrational relaxation time, which results in a hot-ground state spectrum that is the same as observed for water IR excitation at any other frequency. The fastest dynamical time scale is 80 fs for the polarization anisotropy decay, providing evidence for the delocalized or excitonic character of the bend. Normal mode analysis conducted on water clusters extracted from molecular dynamics simulations corroborate significant stretch-bend mixing and indicate delocalization of δHOH on 2-7 water molecules.
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Affiliation(s)
- William B Carpenter
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Joseph A Fournier
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Rajib Biswas
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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20
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Gao X, Cai C, Ma J, Zhang Y. Repartitioning of glycerol between levitated and surrounding deposited glycerol/NaNO 3/H 2O droplets. ROYAL SOCIETY OPEN SCIENCE 2018; 5:170819. [PMID: 29410802 PMCID: PMC5792879 DOI: 10.1098/rsos.170819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 11/24/2017] [Indexed: 06/07/2023]
Abstract
Repartitioning of semi-volatile organic compounds (SVOCs) between particles is an important process to understand the particle growth and shrinkage in the atmosphere environment. Here, by using optical tweezers coupled with cavity-enhanced Raman spectroscopy, we report the repartitioning of glycerol between a levitated glycerol/NaNO3/H2O droplet and surrounding glycerol/NaNO3/H2O droplets deposited on the inner wall of a chamber with different organic to inorganic molar ratios (OIRs). For the high OIR with 3 : 1, no NaNO3 crystallization occurs both for levitated and deposited droplets in the whole relative humidity (RH) range, the radius of the levitated droplet decreases slowly due to the evaporation of glycerol from the levitated droplet at constant RHs. The levitated droplets radii with OIR of 1 : 1 and 1 : 3 increase with constant RHs that are lower than 45.3% and 55.7%, respectively, indicating that the repartitioning of glycerol occurs. The reason is that NaNO3 in the deposited droplets is crystallized when RH is lower than 45.3% for 1 : 1 or 55.7% for 1 : 3. So the vapour pressure of glycerol at the surface of deposited droplets is higher than that of the levitated droplet which always remains as liquid droplet without NaNO3 crystallization, resulting in the transfer of glycerol from the deposited ones to the levitated one. The process of the glycerol repartitioning we discussed herein is a useful model to interpret the repartitioning of SVOCs between the externally mixed particles with different phase states.
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Affiliation(s)
| | | | - Jiabi Ma
- Authors for correspondence: Jiabi Ma e-mail:
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21
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Hygroscopicity of Mixed Glycerol/Mg(NO3)2/Water Droplets Affected by the Interaction between Magnesium Ions and Glycerol Molecules. J Phys Chem B 2015; 119:5558-66. [PMID: 25860879 DOI: 10.1021/acs.jpcb.5b00458] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tropospheric aerosols are usually complex mixtures of inorganic and organic components, which can influence the hygroscopicities of each other. In this research, we applied confocal Raman technology combined with optical microscopy to investigate the relationship between the hygroscopic behavior and the molecular interactions of mixed glycerol/Mg(NO3)2/water droplets. Raman spectra provide detailed structural information about the interactions between glycerol molecules and Mg(2+) ions, as well as information about the interactions between glycerol and NO3(-) ions through electrostatic interaction and hydrogen bonding. The change of the CH2 stretching band of glycerol molecules in mixed droplets suggests that the backbone structures of glycerol mainly transform from αα to γγ in the dehumidifying process, and the additional Mg(2+) ions strongly influence the structure of glycerol molecules. Because the existence of glycerol suppresses the crystallization of Mg(NO3)2·6H2O in the dehumidifying process, Mg(NO3)2 molecules in mixed droplets form an amorphous state rather than forming crystals of Mg(NO3)2·6H2O when the relative humidity is lower than 17.8%. Moreover, in mixed droplets, the molar ratio of NO3(-) to glycerol is higher in the center than in the outer region.
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22
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Chuntonov L, Kumar R, Kuroda DG. Non-linear infrared spectroscopy of the water bending mode: direct experimental evidence of hydration shell reorganization? Phys Chem Chem Phys 2014; 16:13172-81. [PMID: 24871901 PMCID: PMC4130209 DOI: 10.1039/c4cp00643g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure and dynamics of liquid water are further studied by investigating the bend vibrational mode of HDO/D2O and pure H2O via two-dimensional infrared spectroscopy (2D-IR) and linear absorption. The experimental findings and theoretical calculations support a picture in which the HDO bend is localized and the H2O bend is delocalized. The HDO and H2O bends present a loss of the frequency-frequency correlation in subpicosecond time scale. While the loss of correlation for the H2O bend is likely to be associated with the vibrational dynamics of a delocalized transition, the loss of the correlation in the localized HDO bend appears to arise from the fluctuations/rearrangements of the local environment. Interestingly, analysis of the HDO 2D-IR spectra shows the presence of multiple overlapping inhomogeneous distributions of frequencies that interchange in a few picoseconds. Theoretical calculations allow us to propose an atomistic model of the observed vibrational dynamics in which the different inhomogeneous distributions and their interchange are assigned to water molecules with different hydrogen-bond states undergoing chemical exchange. The frequency shifts as well as the concentration of the water molecules with single and double hydrogen-bonds as donors derived from the theory are in good agreement with our experimental findings.
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Affiliation(s)
- Lev Chuntonov
- Ultrafast Optical Processes Laboratory, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Revati Kumar
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Daniel G. Kuroda
- Ultrafast Optical Processes Laboratory, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
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23
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In-situ FTIR-ATR spectroscopic observation on the dynamic efflorescence/deliquescence processes of Na2SO4 and mixed Na2SO4/glycerol droplets. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2013.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Imoto S, Xantheas SS, Saito S. Molecular origin of the difference in the HOH bend of the IR spectra between liquid water and ice. J Chem Phys 2013; 138:054506. [PMID: 23406132 DOI: 10.1063/1.4789951] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The intensity of the HOH bend in the infrared (IR) spectrum of ice is significantly smaller than the corresponding one in liquid water. This difference in the IR intensities of the HOH bend in the two systems is investigated using Molecular Dynamics (MD) simulations with the flexible, polarizable, ab initio based TTM3-F model for water, a potential that correctly reproduces the experimentally observed increase of the HOH angle in liquid water and ice from the water monomer value. We have identified two factors that are responsible for the difference in the intensity of the HOH bend in liquid water and ice: (i) the decrease of the intensity of the HOH bend in ice caused by the strong anti-correlation between the permanent dipole moment of a molecule and the induced dipole moment of neighboring hydrogen bond acceptor molecules, and (ii) the weakening of this anti-correlation by the disordered hydrogen bond network in liquid water. The presence of the anti-correlation in ice is further confirmed by ab initio electronic structure calculations of water pentamer clusters extracted from the trajectories of the MD simulations with the TTM3-F potential for ice and liquid water.
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Affiliation(s)
- Sho Imoto
- The Graduate University for Advanced Studies, Myodaiji, Okazaki, Aichi 444-8585, Japan
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25
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Egorov GI, Makarov DM. Volumetric Properties of Binary Mixtures of Glycerol + tert-Butanol over the Temperature Range 293.15 to 348.15 K at Atmospheric Pressure. J SOLUTION CHEM 2012. [DOI: 10.1007/s10953-012-9813-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Zelent B, Buettger C, Grimsby J, Sarabu R, Vanderkooi JM, Wand AJ, Matschinsky FM. Thermal stability of glucokinase (GK) as influenced by the substrate glucose, an allosteric glucokinase activator drug (GKA) and the osmolytes glycerol and urea. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:769-84. [PMID: 22446163 DOI: 10.1016/j.bbapap.2012.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 02/15/2012] [Accepted: 03/05/2012] [Indexed: 11/27/2022]
Abstract
We investigated how glycerol, urea, glucose and a GKA influence kinetics and stability of wild-type and mutant GK. Glycerol and glucose stabilized GK additively. Glycerol barely affected the TF spectra of all GKs but decreased k(cat), glucose S(0.5) and K(D) values and ATP K(M) while leaving cooperativity unchanged. Glycerol sensitized all GKs to GKA as shown by TF. Glucose increased TF of GKs without influence of glycerol on the effect. Glycerol and GKA affected kinetics and binding additively. The activation energies for thermal denaturation of GK were a function of glucose with K(D)s of 3 and 1mM without and with glycerol, respectively. High urea denatured wild type GK reversibly at 20 and 60°C and urea treatment of irreversibly heat denatured GK allowed refolding as demonstrated by TF including glucose response. We concluded: Glycerol stabilizes GK indirectly without changing the folding structure of the apoenzyme, by restructuring the surface water of the protein, whereas glucose stabilizes GK directly by binding to its substrate site and inducing a compact conformation. Glucose or glycerol (alone or combined) is unable to prevent irreversible heat denaturation above 40°C. However, urea denatures GK reversibly even at 60°C by binding to the protein backbone and directly interacting with hydrophobic side chains. It prevents irreversible aggregation allowing complete refolding when urea is removed. This study establishes the foundation for exploring numerous instability mutants among the more than 600 variant GKs causing diabetes in animals and humans.
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Affiliation(s)
- B Zelent
- Department of Biochemistry and Biophysics and Diabetes Research Center, University of Pennsylvania, Philadelphia, PA 19104, USA
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27
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Chen C, Li WZ, Song YC, Weng LD, Zhang N. Concentration dependence of water self-diffusion coefficients in dilute glycerol–water binary and glycerol–water–sodium chloride ternary solutions and the insights from hydrogen bonds. Mol Phys 2012. [DOI: 10.1080/00268976.2011.641602] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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28
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Cryoradiolysis and cryospectroscopy for studies of heme-oxygen intermediates in cytochromes p450. Methods Mol Biol 2012; 875:375-91. [PMID: 22573452 DOI: 10.1007/978-1-61779-806-1_20] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cryogenic radiolytic reduction is one of the most straightforward and convenient methods of generation and stabilization of reactive iron-oxygen intermediates for mechanistic studies in chemistry and biochemistry. The method is based on one-electron reduction of the precursor complex in frozen solution via exposure to the ionizing radiation at cryogenic temperatures. Such approach allows for accumulation of the fleeting reactive complexes which otherwise could not be generated at sufficient amount for structural and mechanistic studies. Application of this method allowed for characterizing of peroxo-ferric and hydroperoxo-ferric intermediates, which are common for the oxygen activation mechanism in cytochromes P450, heme oxygenases, and nitric oxide synthases, as well as for the peroxide metabolism by peroxidases and catalases.
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29
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Malferrari M, Francia F, Venturoli G. Coupling between Electron Transfer and Protein–Solvent Dynamics: FTIR and Laser-Flash Spectroscopy Studies in Photosynthetic Reaction Center Films at Different Hydration Levels. J Phys Chem B 2011; 115:14732-50. [DOI: 10.1021/jp2057767] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Marco Malferrari
- Laboratorio di Biochimica e Biofisica, Dipartimento di Biologia, Università di Bologna, 40126 Bologna, Italy
| | - Francesco Francia
- Laboratorio di Biochimica e Biofisica, Dipartimento di Biologia, Università di Bologna, 40126 Bologna, Italy
| | - Giovanni Venturoli
- Laboratorio di Biochimica e Biofisica, Dipartimento di Biologia, Università di Bologna, 40126 Bologna, Italy
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, c/o Dipartimento di Fisica, Università di Bologna, 40127 Bologna, Italy
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30
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Goursot A, Mineva T, Bissig C, Gruenberg J, Salahub DR. Structure, dynamics, and energetics of lysobisphosphatidic acid (LBPA) isomers. J Phys Chem B 2010; 114:15712-20. [PMID: 21053942 DOI: 10.1021/jp108361d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lysobisphosphatidic acid (LBPA), or bis(monoacylglycerol)phosphate, is a very interesting lipid, that is mainly found in late endosomes. It has several intriguing characteristics, which differ from those of other animal glycerophospholipids, that may be related to its specific functions, particularly in the metabolism of cholesterol. Its phosphodiester group is bonded at the sn-1 (sn-1') positions of the glycerols rather than at sn-3 (sn-3'); the position of the two fatty acid chains is still under debate but, increasingly, arguments favor the sn-2, sn-2' position in the native molecule, whereas isolation procedures or acidic conditions lead to the thermodynamically more stable sn-3, sn-3' structure. Because of these peculiar features, it can be expected that LBPA shape and interactions with membrane lipids and proteins are related to its structure at the molecular level. We applied quantum mechanical methods to study the structures and stabilities of the 2,2' and 3,3' LBPA isomers, using a step-by-step procedure from glycerol to precursors (in vitro syntheses) and to the final isoforms. The structures of the two positional LBPA isomers are substantially different, showing that the binding positions of the fatty acid chains on the glycerol backbone determine the shape of the LBPA molecule and thus, possibly, its functions. The 3,3' LBPA structures obtained are more stable with respect to the 2,2' form, as expected from experiment. If one argues that the in vivo synthesis starts from the present glycerol conformers and considering the most stable bis(glycero)phosphate structures, the 2,2' isoform should be the most probable isomer.
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Affiliation(s)
- A Goursot
- UMR 5253 CNRS/ENSCM/UM2/UM1 Ecole de Chimie de Montpellier, 8 rue de l'Ecole Normale, 34296, Montpellier, Cedex 5, France
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31
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Sharp KA, Vanderkooi JM. Water in the half shell: structure of water, focusing on angular structure and solvation. Acc Chem Res 2010; 43:231-9. [PMID: 19845327 DOI: 10.1021/ar900154j] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Water is a highly polar molecule, consisting of a very electronegative atom, oxygen, bonded to two weakly electropositive hydrogen atoms with two lone pairs of electrons. These features give water remarkable physical properties, some of which are anomalous, such as its lower density in the solid phase compared with the liquid phase. Its ability to serve as both a hydrogen bond donor and hydrogen bond acceptor governs its role as a solvent, a role that is of central interest for biological chemists. In this Account, we focus on water's properties as a solvent. Water dissolves a vast range of solutes with solubilities that range over 10 orders of magnitude. Differences in solubility define the fundamental dichotomy between polar, or hydrophilic, solutes and apolar, or hydrophobic, solutes. This important distinction plays a large part in the structure, stability, and function of biological macromolecules. The strength of hydrogen bonding depends on the H-O...O H-bond angle, and the angular distribution is bimodal. Changes in the width and frequency of infrared spectral lines and in the heat capacity of the solution provide a measure of the changes in the strength and distribution of angles of the hydrogen bonds. Polar solutes and inorganic ions increase the population of bent hydrogen bonds at the expense of the more linear population, while apolar solutes or groups have the opposite effect. We examine how protein denaturants might alter the solvation behavior of water. Urea has very little effect on water's hydrogen bond network, while guanidinium ions promote more linear hydrogen bonds. These results point to fundamental differences in the protein denaturation mechanisms of these molecules. We also suggest a mechanism of action for antifreeze (or thermal hysteresis) proteins: ordering of water around the surface of these proteins prior to freezing appears to interfere with ice formation.
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Affiliation(s)
- Kim A. Sharp
- E. R. Johnson Research Foundation and Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Jane M. Vanderkooi
- E. R. Johnson Research Foundation and Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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32
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Guo F, Friedman JM. Osmolyte-induced perturbations of hydrogen bonding between hydration layer waters: correlation with protein conformational changes. J Phys Chem B 2009; 113:16632-42. [PMID: 19961206 PMCID: PMC3354986 DOI: 10.1021/jp9072284] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gadolinium vibronic sideband luminescence spectroscopy (GVSBLS) is used to probe osmolyte-induced changes in the hydrogen bond strength between first and second shell waters on the surface of free Gd(3+) and Gd(3+) coordinated to EDTA and to structured calcium binding peptides in solution. In parallel, Raman is used to probe the corresponding impact of the same set of osmolytes on hydrogen bonding among waters in the bulk phase. Increasing concentration of added urea is observed to progressively weaken the hydrogen bonding within the hydration layer but has minimal observed impact on bulk water. In contrast, polyols are observed to enhance hydrogen bonding in both the hydration layer and the bulk with the amplitude being polyol dependent with trehalose being more effective than sucrose, glucose, or glycerol. The observed patterns indicate that the size and properties of the osmolyte as well as the local architecture of the specific surface site of hydration impact preferential exclusion effects and local hydrogen bond strength. Correlation of the vibronic spectra with CD measurements on the peptides as a function of added osmolytes shows an increase in secondary structure with added polyols and that the progressive weakening of the hydrogen bonding upon addition of urea first increases water occupancy within the peptide and only subsequently does the peptide unfold. The results support models in which the initial steps in the unfolding process involve osmolyte-induced enhancement of water occupancy within the interior of the protein.
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Affiliation(s)
- Feng Guo
- Department of Biophysics and Physiology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, New York, U.S.A. 10461
| | - Joel M. Friedman
- Department of Biophysics and Physiology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, New York, U.S.A. 10461
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33
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Chen C, Li WZ, Song YC, Yang J. A molecular dynamics study of cryoprotective agent – Water–sodium chloride ternary solutions. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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34
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Zelent B, Vanderkooi JM. Infrared spectroscopy used to study ice formation: the effect of trehalose, maltose, and glucose on melting. Anal Biochem 2009; 390:215-7. [PMID: 19376080 DOI: 10.1016/j.ab.2009.04.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 04/11/2009] [Indexed: 10/20/2022]
Abstract
We report the use of infrared (IR) spectroscopy to detect ice crystals in biological solutions. The method is based on the temperature dependence of the OH bending and stretch bands of water. By using mixtures of D(2)O and H(2)O, water's absorption bands can be made to be on-scale in transmission mode. Water's stretch band moves to lower frequency and sharpens with freezing, and the bending band goes to higher frequency and becomes less sharp. The technique is demonstrated for the study of the hysteresis of freezing in the presence of glucosyl sugars, namely glucose, maltose, and trehalose.
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Affiliation(s)
- B Zelent
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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35
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Malsam J, Aksan A. Hydrogen Bonding and Kinetic/Thermodynamic Transitions of Aqueous Trehalose Solutions at Cryogenic Temperatures. J Phys Chem B 2009; 113:6792-9. [DOI: 10.1021/jp8099434] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jason Malsam
- Biostabilization Laboratory, Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455
| | - Alptekin Aksan
- Biostabilization Laboratory, Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455
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36
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Chen C, Li W, Song Y, Yang J. Molecular dynamics simulation studies of cryoprotective agent solutions: the relation between melting temperature and the ratio of hydrogen bonding acceptor to donor number. Mol Phys 2009. [DOI: 10.1080/00268970902852632] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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37
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Zelent B, Bryan MA, Sharp KA, Vanderkooi JM. Influence of surface groups of proteins on water studied by freezing/thawing hysteresis and infrared spectroscopy. Biophys Chem 2009; 141:222-30. [PMID: 19251353 DOI: 10.1016/j.bpc.2009.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 02/05/2009] [Accepted: 02/05/2009] [Indexed: 10/21/2022]
Abstract
The influence of proteins and solutes on hysteresis of freezing and melting of water was measured by infrared (IR) spectroscopy. Of the solutes examined, poly-L-arginine and flounder antifreeze protein produced the largest freezing point depression of water, with little effect on the melting temperature. Poly-L-lysine, poly-L-glutamate, cytochrome c and bovine serum albumin had less effect on the freezing of water. Small compounds used to mimic non-polar (trimethylamine N-oxide, methanol), positively charged (guanidinium chloride, NH(4)Cl, urea) and negatively charged (Na acetate) groups on protein surfaces were also examined. These molecules and ions depress water's freezing point and the melting profiles became broad. Since infrared absorption measures both bulk solvent and solvent bound to the solutes, this result is consistent with solutes interacting with liquid water. The amide I absorption bands of antifreeze protein and poly-L-arginine do not detectably change with the phase transition of water. An interpretation is that the antifreeze protein and poly-L-arginine order liquid water such that the water around the group is ice-like.
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Affiliation(s)
- Bogumil Zelent
- The Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, Philadelphia PA 19104, United States
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38
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Zelent B, Vanderkooi JM, Nucci NV, Gryczynski I, Gryczynski Z. Phosphate assisted proton transfer in water and sugar glasses: a study using fluorescence of pyrene-1-carboxylate and IR spectroscopy. J Fluoresc 2009; 19:21-31. [PMID: 18496739 DOI: 10.1007/s10895-008-0375-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 04/10/2008] [Indexed: 10/22/2022]
Abstract
The role of water's H-bond percolation network in acid-assisted proton transfer was studied in water and glycerol solutions and in sugar glasses. Proton transfer rates were determined by the fluorescence of pyrene-1-carboxylate, a compound with a higher pK in its excited state relative to the ground state. Excitation of pyrene-1-COO- produces fluorescence from pyrene-1-COOH when a proton is accepted during the excited singlet state lifetime of pyrene-1-COO-. The presence of glycerol as an aqueous cosolvent decreases proton transfer rates from phosphoric and acetic acid in a manner that does not follow the Stokes relationship on viscosity. In sugar glass composed of trehalose and sucrose, proton transfer occurs when phosphate is incorporated in the glass. Sugar glass containing phosphate retains water and it is suggested that proton transfer requires this water. The infrared (IR) frequency of water bending mode in sugar glass and in aqueous solution is affected by the presence of phosphate and the IR spectral bands of all phosphate species in water are temperature dependent; both results are consistent with H-bonding between water and phosphate. The fluorescence results, which studied the effect of cosolvent, highlight the role of water in assisting proton transfer in reactions involving biological acids, and the IR results, which give spectroscopic evidence for H-bonding between water and phosphate, are consistent with a mechanism of proton transfer involving H-bonding. The possibility that the phosphate-rich surface of membranes assists in proton equilibration in cells is discussed.
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Affiliation(s)
- Bogumil Zelent
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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39
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Sethu Raman M, Ponnuswamy V, Kolandaivel P, Perumal K. Ultrasonic and DFT study of intermolecular association through hydrogen bonding in aqueous solutions of glycerol. J Mol Liq 2008. [DOI: 10.1016/j.molliq.2008.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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40
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Nucci NV, Scott JN, Vanderkooi JM. Coupling of complex aromatic ring vibrations to solvent through hydrogen bonds: effect of varied on-ring and off-ring hydrogen-bonding substitutions. J Phys Chem B 2008; 112:4022-35. [PMID: 18331017 DOI: 10.1021/jp0758770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we examine the coupling of a complex ring vibration to solvent through hydrogen-bonding interactions. We compare phenylalanine, tyrosine, l-dopa, dopamine, norepinephrine, epinephrine, and hydroxyl-dl-dopa, a group of physiologically important small molecules that vary by single differences in H-bonding substitution. By examination of the temperature dependence of infrared absorptions of these molecules, we show that complex, many-atom vibrations can be coupled to solvent through hydrogen bonds and that the extent of that coupling is dependent on the degree of both on- and off-ring H-bonding substitution. The coupling is seen as a temperature-dependent frequency shift in infrared spectra, but the determination of the physical origin of that shift is based on additional data from temperature-dependent optical experiments and ab initio calculations. The optical experiments show that these small molecules are most sensitive to their immediate H-bonding environment rather than to bulk solvent properties. Ab initio calculations demonstrate H-bond-mediated vibrational coupling for the system of interest and also show that the overall small molecule solvent dependence is determined by a complex interplay of specific interactions and bulk solvation characteristics. Our findings indicate that a full understanding of biomolecule vibrational properties must include consideration of explicit hydrogen-bonding interactions with the surrounding microenvironment.
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Affiliation(s)
- Nathaniel V Nucci
- Department of Biochemistry and Biophysics, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, Pennsylvania 19104, USA.
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41
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Nordqvist D, Hedenqvist MS. Properties of amylopectin/montmorillonite composite films containing a coupling agent. J Appl Polym Sci 2007. [DOI: 10.1002/app.26172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Dashnau J, Vanderkooi J. Computational Approaches to Investigate How Biological Macromolecules Can Be Protected in Extreme Conditions. J Food Sci 2007; 72:R001-10. [DOI: 10.1111/j.1750-3841.2006.00242.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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43
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Colosi LM, Huang Q, Weber WJ. Validation of a two-parameter quantitative structure–activity relationship as a legitimate tool for rational re-design of horseradish peroxidase. Biotechnol Bioeng 2007; 98:295-9. [PMID: 17657769 DOI: 10.1002/bit.21419] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previously reported rates of reaction between six mutant strains of the enzyme horseradish peroxidase (HRP) and a test substrate, 2-methoxyphenol, were found to correlate with characteristic binding distances computed using molecular simulation. The correlation (R(2) = 0.86) bears out a working hypothesis that, based on a quantitative structure-activity relationship (QSAR) we had previously developed for HRP, reductions in binding distances between the HRP enzyme and any selected substrate mediate increased enzyme reactivity towards that substrate. The results validate the use of QSAR as a quantitative means for formulating enzyme mutations designed to achieve enhanced HRP reactivity towards compounds of specific interest.
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Affiliation(s)
- Lisa M Colosi
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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44
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Tan B, Rankin SE. Study of the Effects of Progressive Changes in Alkoxysilane Structure on Sol−Gel Reactivity. J Phys Chem B 2006; 110:22353-64. [PMID: 17091975 DOI: 10.1021/jp060376k] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Effects of the structure of an alkoxysilane on the early reaction kinetics of sol-gel polymerization are investigated in basic and acidic conditions. Six silanes, including tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), methyltrimethoxysilane (MTMS), bis(trimethoxysilyl)ethane (BTMSE), bis(trimethoxysilyl)hexane (BTMSH), and bis(trimethoxysilylpropyl)amine (BTMSPA), are selected to examine the effects of progressive changes in the silane's structure. In basic conditions, reactivities of the silanes follow the pairwise trends TEOS << TMOS, TMOS > MTMS, MTMS < BTMSE, BTMSE >> BTMSH, and BTMSH << BTMSPA. Hydrolysis rate coefficients of BTMSE, TMOS, MTMS, and BTMSPA are similar in value and are almost one order of magnitude larger than the coefficients of BTMSH and TEOS. In acidic conditions, the pairwise reactivity trends are TEOS approximately TMOS, TMOS < MTMS, MTMS > BTMSE, BTMSE >> BTMSH, and BTMSH > BTMSPA. The condensation rate coefficients of BTMSH and BTMPA are much smaller than the others. Theses relationships can be explained mainly on the basis of the expected inductive and steric factors of the silanes. Bulky organics attached to the silane lead to low reactivity in both acidic and basic conditions. A high electron density at silicon leads to a low reactivity in basic conditions but a high reactivity in acidic conditions (pH approximately 2.3). Only BTMSPA in basic conditions defies these trends, possibly because of the effects of solvation near the reactive silicon site.
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Affiliation(s)
- Bing Tan
- Department of Chemical & Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, Kentucky 40506-0046, USA
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45
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Dashnau JL, Nucci NV, Sharp KA, Vanderkooi JM. Hydrogen bonding and the cryoprotective properties of glycerol/water mixtures. J Phys Chem B 2006; 110:13670-7. [PMID: 16821896 DOI: 10.1021/jp0618680] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular dynamics simulations and infrared spectroscopy were used to determine the hydrogen bond patterns of glycerol and its mixtures with water. The ability of glycerol/water mixtures to inhibit ice crystallization is linked to the concentration of glycerol and the hydrogen bonding patterns formed by these solutions. At low glycerol concentrations, sufficient amounts of bulk-like water exist, and at low temperature, these solutions demonstrate crystallization. As the glycerol concentration is increased, the bulk-like water pool is eventually depleted. Water in the first hydration shell becomes concentrated around the polar groups of glycerol, and the alkyl groups of glycerol self-associate. Glycerol-glycerol hydrogen bonds become the dominant interaction in the first hydration shell, and the percolation nature of the water network is disturbed. At glycerol concentrations beyond this point, glycerol/water mixtures remain glassy at low temperatures and the glycerol-water hydrogen bond favors a more linear arrangement. High glycerol concentration mixtures mimic the strong hydrogen bonding pattern seen in ice, yet crystallization does not occur. Hydrogen bond patterns are discussed in terms of hydrogen bond angle distributions and average hydrogen bond number. Shift in infrared frequency of related stretch and bend modes is also reviewed.
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Affiliation(s)
- Jennifer L Dashnau
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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46
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Affiliation(s)
- Ninad Prabhu
- Johnson Research Foundation, Dept. of Biochemistry and Biophysics, University of Pennsylvania
| | - Kim Sharp
- Johnson Research Foundation, Dept. of Biochemistry and Biophysics, University of Pennsylvania
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47
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Walters RS, Pillai ED, Duncan MA. Solvation dynamics in Ni+ (H2O)n clusters probed with infrared spectroscopy. J Am Chem Soc 2006; 127:16599-610. [PMID: 16305249 DOI: 10.1021/ja0542587] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared photodissociation spectroscopy is reported for mass-selected Ni+ (H2O)n complexes in the O-H stretching region up to cluster sizes of n = 25. These clusters fragment by the loss of one or more intact water molecules, and their excitation spectra show distinct bands in the region of the symmetric and asymmetric stretches of water. The first evidence for hydrogen bonding, indicated by a broad band strongly red-shifted from the free OH region, appears at the cluster size of n = 4. At larger cluster sizes, additional red-shifted structure evolves over a broader wavelength range in the hydrogen-bonding region. In the free OH region, the symmetric stretch gradually diminishes in intensity, while the asymmetric stretch develops into a closely spaced doublet near 3700 cm(-1). The data indicate that essentially all of the water molecules are in a hydrogen-bonded network by the size of n = 10. However, there is no evidence for the formation of clathrate structures seen recently via IR spectroscopy of protonated water clusters.
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Affiliation(s)
- Richard S Walters
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
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48
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Khajehpour M, Dashnau JL, Vanderkooi JM. Infrared spectroscopy used to evaluate glycosylation of proteins. Anal Biochem 2006; 348:40-8. [PMID: 16298329 DOI: 10.1016/j.ab.2005.10.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Revised: 10/03/2005] [Accepted: 10/04/2005] [Indexed: 11/25/2022]
Abstract
Infrared (IR) spectroscopy is used for studying the carbohydrate moieties of glycosylated proteins. IR spectra of mono- and disaccharides in the fingerprint region are specific to each sugar and to the environment of the sugar molecules (i.e., aqueous solution or anhydrous glass phase). The IR spectra of glycosylated proteins (mucin, soybean peroxidase, collagen IV, and avidin) were compared with those of the constituent sugars and cytochrome c (a protein with no glycosylation). Our results demonstrate that the IR absorption spectra of glycosylated proteins show distinct absorption bands for the sugar moiety, the protein amide group, and water. Therefore, IR can be used to detect glycosylation.
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Affiliation(s)
- Mazdak Khajehpour
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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49
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Zelent B, Yano T, Ohlsson PI, Smith ML, Paul J, Vanderkooi JM. Optical Spectra of Lactoperoxidase as a Function of Solvent. Biochemistry 2005; 44:15953-9. [PMID: 16313199 DOI: 10.1021/bi0513655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The iron of lactoperoxidase is predominantly high-spin at ambient temperature. Optical spectra of lactoperoxidase indicate that the iron changes from high-spin to low-spin in the temperature range from room temperature to 20 K. The transformation is independent of whether the enzyme is in glycerol/water or solid sugar glass. Addition of the inhibitor benzohydroxamic acid increases the amount of the low-spin form, and again the transformation is independent of whether the protein is in an aqueous solution or a nearly anhydrous sugar. In contrast to lactoperoxidase, horseradish peroxidase remains high-spin over the temperature excursion in both solvents and with addition of benzohydroxamic acid. We conclude that details of the heme pocket of lactoperoxidase allow ligation changes with temperature that are dependent upon the apoprotein but independent of solvent fluctuations. At low pH, lactoperoxidase shows a solvent-dependent transition; the high-spin form is predominant in anhydrous sugar glass, but in the presence of water, the low-spin form is also present in abundance. The active site of lactoperoxidase is not as tightly constrained at low pH as at neutrality, though the enzyme is active over a wide pH range.
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Affiliation(s)
- B Zelent
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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50
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Vanderkooi JM, Dashnau JL, Zelent B. Temperature excursion infrared (TEIR) spectroscopy used to study hydrogen bonding between water and biomolecules. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1749:214-33. [PMID: 15927875 DOI: 10.1016/j.bbapap.2005.03.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 02/15/2005] [Accepted: 03/09/2005] [Indexed: 11/22/2022]
Abstract
Water is a highly polar molecule that is capable of making four H-bonding linkages. Stability and specificity of folding of water-soluble protein macromolecules are determined by the interplay between water and functional groups of the protein. Yet, under some conditions, water can be replaced with sugar or other polar protic molecules with retention of protein structure. Infrared (IR) spectroscopy allows one to probe groups on the protein that interact with solvent, whether the solvent is water, sugar or glycerol. The basis of the measurement is that IR spectral lines of functional groups involved in H-bonding show characteristic spectral shifts with temperature excursion, reflecting the dipolar nature of the group and its ability to H-bond. For groups involved in H-bonding to water, the stretching mode absorption bands shift to lower frequency, whereas bending mode absorption bands shift to higher frequency as temperature decreases. The results indicate increasing H-bonding and decreasing entropy occurring as a function of temperature, even at cryogenic temperatures. The frequencies of the amide group modes are temperature dependent, showing that as temperature decreases, the amide group H-bonds to water strengthen. These results are relevant to protein stability as a function of temperature. The influence of solvent relaxation is demonstrated for tryptophan fluorescence over the same temperature range where the solvent was examined by infrared spectroscopy.
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Affiliation(s)
- Jane M Vanderkooi
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, 19104-6059, USA.
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