Institution
Environmental Molecular Sciences Laboratory
Facility•Richland, Washington, United States•
About: Environmental Molecular Sciences Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Mass spectrometry & Ion. The organization has 1471 authors who have published 3010 publications receiving 169961 citations.
Topics: Mass spectrometry, Ion, X-ray photoelectron spectroscopy, Catalysis, Fourier transform ion cyclotron resonance
Papers published on a yearly basis
Papers
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TL;DR: Ionization and molecular weight (MW) determination of megadalton size plasmid DNA has been achieved using electrospray ionization (ESI) with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry.
Abstract: Ionization and molecular weight (MW) determination of megadalton size plasmid DNA has been achieved using electrospray ionization (ESI) with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. DNA molecules were shown to remain intact through electrospray ionization by collection on a specially prepared surface, followed by agarose gel electrophoresis. Individual highly charged ions of plasmid DNA produced by ESI were trapped in an FTICR cell for up to several hours and reacted with acetic acid to induce charge state shifts. Measurements of mass-to-charge ratios for these multiple peaks arising from charge state shifting give MW measurements of individual ions with an average accuracy of 0.2%. The MW distribution was obtained by measurements for a number of individual ions from the same sample [plasmid DNA: pGEM-5S MW(cal) = 1.946 MDa], yielding a MW(obs) of 1.95 +/- 0.07 MDa for ions clustered in the vicinity of the expected MW.
74 citations
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TL;DR: This work presents an approach to calculate the free energy profile along a condensed-phase reaction path based on high-level electronic structure methods for the reactive region using molecular mechanics, density functional theory, and coupled cluster theories.
Abstract: We present an approach to calculate the free energy profile along a condensed-phase reaction path based on high-level electronic structure methods for the reactive region. The bulk of statistical averaging is shifted toward less expensive descriptions by using a hierarchy of representations that includes molecular mechanics, density functional theory, and coupled cluster theories. As an application of this approach we study the reaction of CHCl3 with OH− in aqueous solution.
74 citations
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TL;DR: The pH dependence of the (67)Zn solid-state nuclear magnetic resonance spectroscopy of human carbonic anhydrase (CAII) has been investigated and the NMR data is consistent with an alternative mechanism of CAII, including the EFG interaction.
Abstract: The pH dependence of the (67)Zn solid-state nuclear magnetic resonance spectroscopy of human carbonic anhydrase (CAII) has been investigated to characterize the nature of the fourth ligand. CAII, through the Zn(2+)-bound hydroxide, catalyzes the deceptively simple reaction: CO(2) + H(2)O HCO(3)(-) + H(+). The accepted mechanism for CAII would predict that water would be bound to the Zn(2+) at pH 5 and hydroxide would be bound at pH 8.5. The measured values for the electric field gradient (EFG) or quadrupole coupling constant (Cq) for CAII are independent of pH within the limits of the experimental error, i.e., 9.8 +/- 0.2 MHz. The EFG interaction has been predicted by ab initio electronic structure calculations for water and hydroxide bound to the zinc, including various levels of hydrogen bonding. After comparing the predicted Cq's with the experimental values, we conclude that the species present from pH 5-8.5 is the hydroxide form. The NMR data presented here is not consistent with the accepted mechanism for CAII. We show that the NMR data is consistent with an alternative mechanism of CAII.
74 citations
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TL;DR: The authors measure the alignment forces in ZnO using dynamic force spectroscopy, highlighting the role of intervening water molecules, and reveal an attractive force with 60o rotational periodicity.
Abstract: Crystallization by particle attachment is impacting our understanding of natural mineralization processes and holds promise for novel materials design. When particles assemble in crystallographic alignment, expulsion of the intervening solvent and particle coalescence are enabled by near-perfect co-alignment via interparticle forces that remain poorly quantified. Here we report measurement and simulation of these nanoscale aligning forces for the ZnO(0001)-ZnO(000
$$\bar 1$$
) system in aqueous solution. Dynamic force spectroscopy using nanoengineered single crystal probes reveals an attractive force with 60o rotational periodicity. Calculated distance and orientation-dependent potentials of mean force show several attractive free energy wells distinguished by numbers of intervening water layers, which reach a minimum when aligned. The calculated activation energy to separate the attractively bound solvated interfaces perfectly reproduces the measured 60o periodicity, revealing the key role of intervening water structuring as a basis to generate the interparticle torque that completes alignment and enables coalescence. Crystal growth is a fundamental process, important in a wide range of fields, but the interparticle forces responsible for molecule alignment are not well understood. Here, the authors measure the alignment forces in ZnO using dynamic force spectroscopy, highlighting the role of intervening water molecules.
74 citations
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TL;DR: In this paper, an acid-catalyzed sol-gel formation process in acetonitrile was reported, in which wet GO-loaded gels were realized within 2h at temperatures below 45°C. Spectroscopic and electrochemical analysis following supercritical drying and pyrolysis confirmed the reduction of the GO in the aerogels to sp2 carbon crystallites with no residual carbon-nitrogen bonds from the acetonitile or its derivatives.
73 citations
Authors
Showing all 1477 results
Name | H-index | Papers | Citations |
---|---|---|---|
George M. Whitesides | 240 | 1739 | 269833 |
Yi Cui | 220 | 1015 | 199725 |
Donald G. Truhlar | 165 | 1518 | 157965 |
Ronald W. Davis | 155 | 644 | 151276 |
Richard D. Smith | 140 | 1180 | 79758 |
Yuehe Lin | 118 | 641 | 55399 |
Robert C. Haddon | 112 | 577 | 52712 |
Lai-Sheng Wang | 103 | 576 | 36212 |
Mark H. Engelhard | 103 | 545 | 39864 |
Alex Guenther | 100 | 447 | 45476 |
Gordon E. Brown | 100 | 454 | 32152 |
X. Sunney Xie | 98 | 225 | 44104 |
Jun Li | 98 | 631 | 40958 |
Richard A. Friesner | 97 | 367 | 52729 |
Chongmin Wang | 95 | 451 | 33983 |