Abstract:
:We have localized an area in the human brain involved in the processing of contours defined by motion differences (kinetic contours) by comparing with positron emission tomography the regional cerebral blood flow in tasks performed with kinetic and luminance-defined gratings. These tasks included passive viewing, counting the total number of grating stimuli, and counting the number of gratings of a given orientation. Comparison between the counting tasks and passive viewing with a given type of contour revealed a set of active areas that were similar for both luminance-defined and kinetic contours. Comparisons between these two types of contours revealed a single focus in the right hemisphere that did not overlap with the many regions activated by uniform motion. In particular this "kinetic focus" was clearly separated from the area previously defined as the human homologue of V5/middle temporal. Activity in this kinetic focus was stronger when orientation had to be processed than in the other two tasks. These results and control experiments with uniformly moving random dot patterns suggest the existence of an area in the human visual system that is activated much more by kinetic contours than by luminance contours or uniformly moving random dots. Up to now, such an area has not been described in the monkey visual system.
journal_name
Proc Natl Acad Sci U S Aauthors
Orban GA,Dupont P,De Bruyn B,Vogels R,Vandenberghe R,Mortelmans Ldoi
10.1073/pnas.92.4.993subject
Has Abstractpub_date
1995-02-14 00:00:00pages
993-7issue
4eissn
0027-8424issn
1091-6490journal_volume
92pub_type
杂志文章abstract::It had long been thought, but never demonstrated, that imino acids are formed in the reactions catalyzed by D- and L-amino acid oxidases (EC 1.4.3.3 and 1.4.3.2). The formation of imino acids is now shown directly by allowing the amino acid oxidase reaction to proceed in the presence of NaBH(4), when the imino acid 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.68.5.987
更新日期:1971-05-01 00:00:00
abstract::We have isolated several lines of rat embryo cells transformed by simian virus 40. All these lines are fully transformed with regard to saturation density and serum sensitivity, but they differ greatly in their anchorage dependence, as assayed by efficiency of plating in methyl cellulose suspension. This set of lines ...
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.71.12.4792
更新日期:1974-12-01 00:00:00
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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.97.2.859
更新日期:2000-01-18 00:00:00
abstract::Lactate racemase is the first enzyme known to possess a metal pincer active site. The enzyme interconverts d- and l-lactic acid, which is important for the assembly of cell walls in many microorganisms. Here, we report a synthetic model of the active site of lactate racemase, which features a pyridinium-based SCS pinc...
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.1616038114
更新日期:2017-02-07 00:00:00
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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.74.12.5482
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abstract::The interaction of carboxylate ions (acetate, butyrate) with nucleic aicd bases and nucleosides has been investigated by proton magnetic resonance in dimethyl sulfoxide (d6)/H2O mixtures. Carboxylate ions interacted only with guanine derivatives and led to a large downfield shift of the NH2 resonance. A 1:1 stoichiome...
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.74.11.4872
更新日期:1977-11-01 00:00:00
abstract::A continuous fluorescence-based assay is described for measuring helicase-mediated unwinding of duplex DNA. The assay utilizes an oligonucleotide substrate containing the fluorescent adenine analog, 2-aminopurine, at regular intervals. 2-Aminopurine forms a Watson-Crick-type base pair with thymine and does not distort...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2006-05-16 00:00:00
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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.92.14.6319
更新日期:1995-07-03 00:00:00
abstract::A series of recombinant plasmids was generated in Escherichia coli in which the TEM beta-lactamase translocon (TnA) was inserted into the small plasmid RSF1010. RSF1010 is a 5.5 X 10(6) dalton nonconjugative plasmid which confers resistance to streptomycin and sulfonamide. The recombinant plasmids can be classified in...
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.72.9.3623
更新日期:1975-09-01 00:00:00
abstract::The lateral neural plate border (NPB), the neural part of the vertebrate neural border, is composed of central nervous system (CNS) progenitors and peripheral nervous system (PNS) progenitors. In invertebrates, PNS progenitors are also juxtaposed to the lateral boundary of the CNS. Whether there are conserved molecula...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2017-08-01 00:00:00
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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.1808645116
更新日期:2019-04-16 00:00:00
abstract::IL-7 functions as a trophic factor during T lymphocyte development by a mechanism that is partly based on the induction of Bcl-2, which protects cells from apoptosis. Here we report a mechanism by which cytokine withdrawal activates the prodeath protein Bax. On loss of IL-7 in a dependent cell line, Bax protein transl...
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.96.25.14476
更新日期:1999-12-07 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2017-02-14 00:00:00
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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.1337185100
更新日期:2003-06-24 00:00:00
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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.1612362113
更新日期:2016-10-18 00:00:00
abstract::Prior studies have identified a subset of dendritic cells in human blood, as well as their stimulatory function for T-cell-mediated immune responses. However research has been limited by difficulties in isolation, since dendritic cells make up only 0.1-1% of blood mononuclear cells. We present a protocol that reliably...
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.87.19.7698
更新日期:1990-10-01 00:00:00
abstract::Using an antibody highly specific for D-serine conjugated to glutaraldehyde, we have localized endogenous D-serine in rat brain. Highest levels of D-serine immunoreactivity occur in the gray matter of the cerebral cortex, hippocampus, anterior olfactory nucleus, olfactory tubercle, and amygdala. Localizations of D-ser...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1995-04-25 00:00:00
abstract::Specific protein domains and amino acids responsible for the apparent capacity of P-glycoprotein (mdr) to recognize and transport a large group of structurally unrelated drugs have not been identified. We have introduced a single Ser----Phe substitution within the predicted TM11 domain of mdr1 (position 941) and mdr3 ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2017-05-16 00:00:00
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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.78.12.7806
更新日期:1981-12-01 00:00:00
abstract::Heavy electronic states originating from the f atomic orbitals underlie a rich variety of quantum phases of matter. We use atomic scale imaging and spectroscopy with the scanning tunneling microscope to examine the novel electronic states that emerge from the uranium f states in URu(2)Si(2). We find that, as the tempe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2010-06-08 00:00:00
abstract::Most aminoacyl-tRNA synthetases contain polypeptide chains of about either 50,000 or 100,000 daltons. Peptide mapping of tryptic, chymotryptic, or Staphylococcus aureus acid protease digests of seryl-tRNA synthetase (100,000, dimer) and leucyl-tRNA synthetase (100,000, monomer) from E. coli was done after selective mo...
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.71.2.376
更新日期:1974-02-01 00:00:00
abstract::Oligomerization of members of the p53 family of transcription factors (p53, p63, and p73) is essential for their distinct functions in cell-cycle control and development. To elucidate the molecular basis for tetramer formation of the various family members, we solved the crystal structure of the human p73 tetramerizat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2009-10-20 00:00:00
abstract::Ionizing radiation (IR) induces a variety of DNA lesions among which DNA double-strand breaks (DSBs) are the biologically most significant. It is currently unclear if DSB repair is equally efficient after low and high doses. Here, we use gamma-H2AX, phospho-ATM (pATM), and 53BP1 foci analysis to monitor DSB repair. We...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2010-08-10 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1986-09-01 00:00:00
abstract::We have compared chicken erythrocyte linker histones H1 and H5 binding to a synthetic four-way DNA junction. Each histone binds to form a single complex, with an affinity which permits competition against a large excess of linear duplex DNA. The affinity of H5 is higher than that of H1. The globular domain from either...
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.91.9.3525
更新日期:1994-04-26 00:00:00
abstract::We report a comprehensive cartography of selective responses to visual letters and words in the human ventral occipito-temporal cortex (VOTC) with direct neural recordings, clarifying key aspects of the neural basis of reading. Intracerebral recordings were performed in a large group of patients (n = 37) presented wit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2018-08-07 00:00:00
abstract::Genetically engineered mice with targeted disruption of the neuronal nitric oxide synthase (nNOS) gene established the inhibitory role of nitric oxide (NO) in male impulsive aggressive behavior. This was later confirmed by using selective nNOS inhibitors in male wild-type mice. The molecular mechanisms accounting for ...
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.031487198
更新日期:2001-01-30 00:00:00
abstract::Human skeletal muscle is composed of various muscle fiber types. We hypothesized that differences in metabolism between fiber types could be detected noninvasively with 31P nuclear magnetic resonance spectroscopy during maximal exercise. This assumes that during maximal exercise all fiber types are recruited and all v...
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.88.13.5714
更新日期:1991-07-01 00:00:00