Abstract:
:Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac-Hartree-Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor-crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg2Cl2), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from (119)Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium.
journal_name
Proc Natl Acad Sci U S Aauthors
Schauble EAdoi
10.1073/pnas.1216216110subject
Has Abstractpub_date
2013-10-29 00:00:00pages
17714-9issue
44eissn
0027-8424issn
1091-6490pii
1216216110journal_volume
110pub_type
杂志文章abstract::A light beam hitting the retina produces an excitatory process; however, around the edge of the light beam, sensory cells are inhibited and lose their sensitivity. This combination of stimulation and inhibition produces a discrepancy between the luminance pattern presented to the eye and the brightness pattern that is...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.69.4.885
更新日期:1972-04-01 00:00:00
abstract::SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0404220101
更新日期:2004-08-03 00:00:00
abstract::A nitrogenase-inspired biomimetic chalcogel system comprising double-cubane [Mo2Fe6S8(SPh)3] and single-cubane (Fe4S4) biomimetic clusters demonstrates photocatalytic N2 fixation and conversion to NH3 in ambient temperature and pressure conditions. Replacing the Fe4S4 clusters in this system with other inert ions such...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1605512113
更新日期:2016-05-17 00:00:00
abstract::The localization of calmodulin, a calcium-dependent modulator of many enzymes, was studied in rat liver, skeletal muscle, and adrenal slices. Calmodulin is found in liver cytoplasm, nucleus, and plasma membrane. Much of the cytoplasmic calmodulin is associated with glycogen particles presumably bound to enzymes involv...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.1.366
更新日期:1980-01-01 00:00:00
abstract::Sets of Burkitt lymphoma lines and Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) derived from the same individuals were compared for sensitivity to cytotoxic T-lymphocyte (CTL) clones. Major histocompatibility complex class I antigen-restricted CTL clones were generated by stimulating the lymph...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.15.5620
更新日期:1986-08-01 00:00:00
abstract::Although rigorous measures of similarity for sequence and structure are now well established, the problem of defining functional relationships has been particularly daunting. Here, we present several manifold embedding techniques to compute distances between Gene Ontology (GO) functional annotations and consequently e...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0702965104
更新日期:2007-07-03 00:00:00
abstract::beta-Endorphin, an opiate-like peptide, has potent antinociceptive properties when it is administered directly into the brain and assayed in the the tail-flick, hot-plate, and writhing tests in mice and in the wet shake test in rats. On a molar basis, beta-endorphin is 18 to 33 times more potent than morphine and its ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.8.2895
更新日期:1976-08-01 00:00:00
abstract::Earlier work has shown that mitochondrial proteins synthesized in the cytosol are initially made as larger precursors which are then transferred into the organelles and processed to their mature size in the absence of protein synthesis. It is now demonstrated that depletion of the mitochondrial matrix ATP in intact ye...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.9.4365
更新日期:1979-09-01 00:00:00
abstract::We have established a recombinant inbred strain of mouse named spontaneous crescentic glomerulonephritis-forming mouse/Kinjoh or SCG/Kj. Mice of this strain spontaneously develop rapidly progressive glomerulonephritis. This strain of mice was derived from (BXSB/Mp x MRL/Mp-lpr/lpr)F1 hybrid mice by brother x sister ma...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.8.3413
更新日期:1993-04-15 00:00:00
abstract::Soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) protein interactions at the synaptic vesicle/plasma membrane interface play an essential role in neurotransmitter release. The membrane-proximal region (amino acids 77-90) of the v-SNARE vesicle-associated membrane protein 2 (VAMP 2,...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0303274101
更新日期:2004-02-10 00:00:00
abstract::Plants frequently respond to herbivorous insect attack by synthesizing defense proteins that deter insect feeding and prevent additional herbivory. Maize (Zea mays L.) lines, resistant to feeding by a number of lepidopteran species, rapidly mobilize a unique 33-kDa cysteine protease in response to caterpillar feeding....
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.202224899
更新日期:2002-10-01 00:00:00
abstract::Endosomal cargo travels through a dynamic vesicle network en route to degradation by lysosomes or recycling through the Golgi apparatus back to the cell surface. Rab5 is a key determinant of the early endosomes by organizing effector proteins in specific subdomains and mediating early endosome fusion. We find that ear...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0711707105
更新日期:2008-06-10 00:00:00
abstract::Superoxide dismutases (SODs; superoxide: superoxide oxidoreductase, EC 1.15.1.1) play a key role in protection against oxygen radicals, and SOD gene expression is highly induced during environmental stress. To determine the conditions of SOD induction, the promoter of the cytosolic copper/zinc SOD (Cu/ZnSODcyt) gene w...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.7.3108
更新日期:1993-04-01 00:00:00
abstract::Understanding Hadean (>4 Ga) Earth requires knowledge of its crust. The composition of the crust and volatiles migrating through it directly influence the makeup of the atmosphere, the composition of seawater, and nutrient availability. Despite its importance, there is little known and less agreed upon regarding the n...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1720880115
更新日期:2018-06-19 00:00:00
abstract::Rat brain and adrenal gland were analyzed by hybridization histochemistry using an RNA probe complementary to mRNA for tyrosine 3-hydroxylase (TyrOHase; tyrosine 3-monooxygenase, EC 1.14.16.2), by immunohistochemistry using TyrOHase antiserum, and by retrograde tracing using the fluorescent compound Fast blue. Cell bo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.16.6208
更新日期:1986-08-01 00:00:00
abstract::Food avoidance learning in the mollusc Pleurobranchaea entails reduction in the responsiveness of key brain interneurons in the feeding neural circuitry, the paracerebral feeding command interneurons (PCNs), to the neurotransmitter acetylcholine (AcCho). Food stimuli applied to the oral veil of an untrained animal dep...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.12.4556
更新日期:1986-06-01 00:00:00
abstract::Fetal cerebral neurons at the initiation of active neurite outgrowth in culture incorporate 4-fold more [3H]glucosamine into glycoproteins than into the cellular lipid fraction. After 8 days or longer, when a well-developed fiber network is apparent, lipids are labeled more extensively than the glycoproteins. Labeling...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.18.5638
更新日期:1984-09-01 00:00:00
abstract::The evolution of sensory systems has let mammals develop complicated tactile end organs to enable sophisticated sensory tasks, including social interaction, environmental exploration, and tactile discrimination. The Merkel disc, a main type of tactile end organ consisting of Merkel cells (MCs) and Aβ-afferent endings,...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1610176113
更新日期:2016-09-13 00:00:00
abstract::Goblet-cell hyperplasia is a critical pathological feature in hypersecretory diseases of airways. However, the underlying mechanisms are unknown, and no effective therapy exists. Here we show that stimulation of epidermal growth factor receptors (EGF-R) by its ligands, EGF and transforming growth factor alpha (TGFalph...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.6.3081
更新日期:1999-03-16 00:00:00
abstract::The mammalian anx7 gene codes for a Ca(2+)-activated GTPase, which supports Ca(2+)/GTP-dependent secretion events and Ca(2+) channel activities in vitro and in vivo. To test whether anx7 might be involved in Ca(2+) signaling in secreting pancreatic beta cells, we knocked out the anx7 gene in the mouse and tested the i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.24.13783
更新日期:1999-11-23 00:00:00
abstract::HU, the major DNA binding protein of Escherichia coli, exists in solution as a heterodimer composed of two highly homologous subunits: HU1, encoded by hupB; HU2, encoded by hupA. The purification of the HU protein from hupA- or hupB- bacteria showed that the hupB mutant strains synthesize normal amounts of the HU2 sub...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.20.7691
更新日期:1989-10-01 00:00:00
abstract::Multidrug resistance in Gram-negative bacteria, to which multidrug efflux pumps such as the AcrB transporter makes a major contribution, is becoming a major public health problem. Unfortunately only a few compounds have been cocrystallized with AcrB, and thus computational approaches are essential in elucidating the i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1218348109
更新日期:2012-12-11 00:00:00
abstract::Very thin (2.3-5.5 nm) self-assembled organic dielectric multilayers have been integrated into organic thin-film transistor structures to achieve sub-1-V operating characteristics. These new dielectrics are fabricated by means of layer-by-layer solution phase deposition of molecular silicon precursors, resulting in sm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0501027102
更新日期:2005-03-29 00:00:00
abstract::Zachariae Isstrøm (ZI) and Nioghalvfjerdsfjorden (79N) are marine-terminating glaciers in northeast Greenland that hold an ice volume equivalent to a 1.1-m global sea level rise. ZI lost its floating ice shelf, sped up, retreated at 650 m/y, and experienced a 5-gigaton/y mass loss. Glacier 79N has been more stable des...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2015483118
更新日期:2021-01-12 00:00:00
abstract::Genetic studies in mice suggest that Wnt4 signaling antagonizes expression of male hormones and effectively blocks male development in the female embryo. We recently identified an XY intersex patient carrying a chromosomal duplication of the WNT4 locus and proposed that this patient's feminization arises from an incre...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1834480100
更新日期:2003-09-16 00:00:00
abstract::One of the most fundamental functions of the brain is to predict upcoming events on the basis of the recent past. A closely related function is to signal when a prediction has been violated. The identity of the brain regions that mediate these functions is not known. We set out to determine whether they are implemente...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1112895108
更新日期:2011-11-29 00:00:00
abstract::Understanding the approach to faulting in continental rocks is critical for identifying processes leading to fracturing in geomaterials and the preparation process of large earthquakes. In situ dynamic X-ray imaging and digital volume correlation analysis of a crystalline rock core, under a constant confining pressure...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1902994116
更新日期:2019-08-13 00:00:00
abstract::Helper T lymphocytes recognize fragments of foreign (or self) antigens in the peptide-binding clefts of major histocompatibility complex class II molecules; their activation is a crucial step in the induction of many immune and autoimmune responses. While studying the latter, we raised a T-cell line from the thymus of...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.16.7343
更新日期:1991-08-15 00:00:00
abstract::Cerebellar granule cells are the most abundant neurons in the brain, and granule cell precursors (GCPs) are a common target of transformation in the pediatric brain tumor medulloblastoma. Proliferation of GCPs is regulated by the secreted signaling molecule Sonic hedgehog (Shh), but the mechanisms by which Shh control...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0832317100
更新日期:2003-06-10 00:00:00
abstract::The X gene product encoded by the hepatitis B virus, termed pX, is a promiscuous transactivator of a variety of viral and cellular genes under the control of diverse cis-acting elements. Although pX does not appear to directly bind DNA, pX-responsive elements include the NF-kappa B, AP-1, and CRE (cAMP response elemen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.9.3819
更新日期:1995-04-25 00:00:00