Visual motion perception.

abstract：:The influence of oxidation state on the pH dependence of the dissolution of the Fe(4)S(4) clusters of Chromatium vinosum ferredoxin and high-potential iron protein (HIPIP) has been studied. The first-order rate constants (k(obs)) for dissolution of both the Fe(4)S(4)(S-Cys)(4) (2-) and Fe(4)S(4)(S-Cys)(4) (3-) cluster...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Maskiewicz R,Bruice TC

更新日期：1977-12-01 00:00:00

abstract：:Mitochondrial protein kinases (mPKs) are molecular switches that down-regulate the oxidation of branched-chain alpha-ketoacids and pyruvate. Elevated levels of these metabolites are implicated in disease states such as insulin-resistant Type II diabetes, branched-chain ketoaciduria, and primary lactic acidosis. We rep...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Machius M,Chuang JL,Wynn RM,Tomchick DR,Chuang DT

更新日期：2001-09-25 00:00:00

abstract：:The highly aggressive character of melanoma makes it an excellent model for probing the mechanisms underlying metastasis, which remains one of the most difficult challenges in treating cancer. We find that miR-182, member of a miRNA cluster in a chromosomal locus (7q31-34) frequently amplified in melanoma, is commonly...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Segura MF,Hanniford D,Menendez S,Reavie L,Zou X,Alvarez-Diaz S,Zakrzewski J,Blochin E,Rose A,Bogunovic D,Polsky D,Wei J,Lee P,Belitskaya-Levy I,Bhardwaj N,Osman I,Hernando E

更新日期：2009-02-10 00:00:00

abstract：:Extensive studies have detailed the molecular regulation of individual components of the hemostatic system, including platelets, coagulation factors, and regulatory proteins. Questions remain, however, about how these elements are integrated at the systems level within a rapidly changing physical environment. To answe...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tomaiuolo M,Matzko CN,Poventud-Fuentes I,Weisel JW,Brass LF,Stalker TJ

更新日期：2019-02-05 00:00:00

abstract：:High-valent iron-oxo species are thought to be intermediates in the catalytic cycles of oxygenases and peroxidases. An attractive route to these iron-oxo intermediates involves laser flash-quench oxidation of ferric hemes, as demonstrated by our work on the ferryl (compound II) and ferryl porphyrin radical cation (com...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ener ME,Lee YT,Winkler JR,Gray HB,Cheruzel L

更新日期：2010-11-02 00:00:00

abstract：:Any isospectral family of two-dimensional Euclidean domains is shown to be compact in the C(infinity) topology. Previously Melrose, using heat invariants, was able to establish the C(infinity) compactness of the curvature of the boundary curves. The additional ingredient used in this paper to obtain the compactness of...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Osgood B,Phillips R,Sarnak P

更新日期：1988-08-01 00:00:00

abstract：:Fumarase C was strongly induced by paraquat in a parental strain of Escherichia coli but was not induced in a strain lacking the soxRS response. Moreover, a strain that constitutively expresses the soxRS regulon contained more fumarase C than did the parental strain. The Mn-containing superoxide dismutase and glucose-...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Liochev SI,Fridovich I

更新日期：1992-07-01 00:00:00

abstract：:Signaling in the nervous system requires matching of neurotransmitter receptors with cognate neurotransmitters at synapses. The vertebrate neuromuscular junction is the best studied cholinergic synapse, but the mechanisms by which acetylcholine is matched with acetylcholine receptors are not fully understood. Because ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Borodinsky LN,Spitzer NC

更新日期：2007-01-02 00:00:00

abstract：:The rpoS gene of Escherichia coli encodes a putative RNA polymerase sigma factor that is considered to be the central regulator of gene expression in stationary phase. The gene product (sigma 38) was overproduced using the cloned rpoS gene and purified to homogeneity. Reconstituted RNA polymerase holoenzyme (E sigma 3...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tanaka K,Takayanagi Y,Fujita N,Ishihama A,Takahashi H

更新日期：1993-04-15 00:00:00

abstract：:Clostridium difficile has rapidly emerged as the leading cause of antibiotic-associated diarrheal disease, with the transcontinental spread of various PCR ribotypes, including 001, 017, 027 and 078. However, the genetic basis for the emergence of C. difficile as a human pathogen is unclear. Whole genome sequencing was...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： He M,Sebaihia M,Lawley TD,Stabler RA,Dawson LF,Martin MJ,Holt KE,Seth-Smith HM,Quail MA,Rance R,Brooks K,Churcher C,Harris D,Bentley SD,Burrows C,Clark L,Corton C,Murray V,Rose G,Thurston S,van Tonder A,Walker D

更新日期：2010-04-20 00:00:00

abstract：:It is proved that the well known Nagata automorphism of the polynomial ring in three variables over a field of characteristic zero is wild, that is, it can not be decomposed into a product of elementary automorphisms. ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shestakov IP,Umirbaev UU

更新日期：2003-10-28 00:00:00

abstract：:Over the past years, family 18 chitinases have been validated as potential targets for the design of drugs against human pathogens that contain or interact with chitin during their normal life cycles. Thus far, only one potent chitinase inhibitor has been described in detail, the pseudotrisaccharide allosamidin. Recen...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Houston DR,Shiomi K,Arai N,Omura S,Peter MG,Turberg A,Synstad B,Eijsink VG,van Aalten DM

更新日期：2002-07-09 00:00:00

abstract：:Taz1 is a hybrid signal-transducing membrane receptor between Tar, an aspartate chemoreceptor, and EnvZ, an osmosensor of Escherichia coli that is able to induce ompC expression by phosphorylating OmpR (a transcriptional activator) in response to aspartate. When the Taz1 His-277, the proposed autophosphorylation site ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yang Y,Inouye M

更新日期：1991-12-15 00:00:00

abstract：:Apomixis is a naturally occurring mode of reproduction that results in embryo formation without the involvement of meiosis or fertilization of the egg. Seed-derived progeny of an apomictic plant are genetically identical to the maternal parent. We are studying a form of apomixis called apospory that occurs in the genu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ozias-Akins P,Roche D,Hanna WW

更新日期：1998-04-28 00:00:00

abstract：:Hybrid wheat plants are superior in yield and growth characteristics compared with their homozygous parents. The commercial production of wheat hybrids is difficult because of the inbreeding nature of wheat and the lack of a practical fertility control that enforces outcrossing. We describe a hybrid wheat system that ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kempe K,Rubtsova M,Gils M

更新日期：2014-06-24 00:00:00

abstract：:A change in the conformation of the active site of scallop myosin under the influence of regulatory amounts of Ca2+ has been identified by use of the ADP photoaffinity analog 2-[(4-azido-2-nitrophenyl)amino]ethyl diphosphate (NANDP). NANDP, trapped at the active site with Mn2+ and vanadate, photolabeled preferentially...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kerwin BA,Yount RG

更新日期：1993-01-01 00:00:00

abstract：:RNA transcription in Euglena gracilis chloroplasts has been characterized by hybridization of RNA from cells at different stages of chloroplast development to (3)H-labeled chloroplast DNA restriction endonuclease fragments. Chloroplast DNA was digested into five fragments of 53,000, 35,000, 25,000, 10,000, and 6900 ba...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chelm BK,Hallick RB,Gray PW

更新日期：1979-05-01 00:00:00

abstract：:Three enzyme reactions have been reported to catalyze the synthesis of phosphoribosylamine in eukaryotic cells. These activities are glutamine phosphoribosylpyrophosphate (P-Rib-P-P) amidotransferase [amidophosphoribosyl-transferase; 5-phosphoribosylamine: pyrophosphate phosphoribosyltransferase (glutamate-amidating) ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Holmes EW,King GL,Leyva A,Singer SC

更新日期：1976-07-01 00:00:00

abstract：:alpha-1-Antitrypsin is a serum protein that inhibits many proteolytic enzymes. Recently, it was suggested that the alpha-1-antitrypsin-trypsin complex is an acyl ester analogous to the acyl intermediate that forms between trypsin and its substrates. In previous work we showed that the alpha-1-antitrypsin-trypsin compl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cohen AB,Gruenke LD,Craig JC,Geczy D

更新日期：1977-10-01 00:00:00

abstract：:Regulation of biological phenomena occurs in all types of systems, being manifested in many different reaction types, from allosteric behavior in proteins, through modulation in energy and information transfer, to the control of growth and differentiation in cells, organelles, and organisms. In this communication, a m...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sligar SG,Gunsalus IC

更新日期：1976-04-01 00:00:00

abstract：:Plasmids that contain synthetic genes coding for small oligoribonucleotides called external guide sequences (EGSs) have been introduced into strains of Escherichia coli harboring antibiotic resistance genes. The EGSs direct RNase P to cleave the mRNAs transcribed from these genes thereby converting the phenotype of dr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Guerrier-Takada C,Salavati R,Altman S

更新日期：1997-08-05 00:00:00

abstract：:Turbulence in fluids is a ubiquitous, fascinating, and complex natural phenomenon that is not yet fully understood. Unraveling turbulence in high density, high temperature plasmas is an even bigger challenge because of the importance of electromagnetic forces and the typically violent environments. Fascinating and nov...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mondal S,Narayanan V,Ding WJ,Lad AD,Hao B,Ahmad S,Wang WM,Sheng ZM,Sengupta S,Kaw P,Das A,Kumar GR

更新日期：2012-05-22 00:00:00

abstract：:An improved electron cloud bolometer is analyzed. In this device the cloud temperature is read out not via thermal noise induced by the electrons in a coupled LC circuit but via shift in their axial oscillation frequency in the Penning trap confining them. This shift occurs because as the electron cloud expands with i...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dehmelt H

更新日期：1994-07-05 00:00:00

abstract：:The molecular mechanisms by which transcription is selectively activated and precisely controlled by signal transducer and activator of transcription (Stat) factors represent a central issue in cytokine-mediated cellular responses. Stat6 mediates responses to IL-4 and antagonizes Stat1 activated by IFN-gamma. We have ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Goenka S,Boothby M

更新日期：2006-03-14 00:00:00

abstract：:A Chinese hamster ovary cell (CHO) mutant (strain 58), defective in CDP-choline synthetase (cholinephosphate cytidylyltransferase; CTP:cholinephosphate cytidylyltransferase, EC 2.7.7.15), is temperature sensitive for growth and contains less than half of the normal amount of phosphatidylcholine under nonpermissive con...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Esko JD,Nishijima M,Raetz CR

更新日期：1982-03-01 00:00:00

abstract：:In 100 primary colorectal carcinomas, we demonstrate by array comparative genomic hybridization (aCGH) that 33% show DNA copy number (DCN) loss involving PARK2, the gene encoding PARKIN, the E3 ubiquitin ligase whose deficiency is responsible for a form of autosomal recessive juvenile parkinsonism. PARK2 is located on...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Poulogiannis G,McIntyre RE,Dimitriadi M,Apps JR,Wilson CH,Ichimura K,Luo F,Cantley LC,Wyllie AH,Adams DJ,Arends MJ

更新日期：2010-08-24 00:00:00

abstract：:Peace River is one of the few shocked members of the L-chondrites clan that contains both high-pressure polymorphs of olivine, ringwoodite and wadsleyite, in diverse textures and settings in fragments entrained in shock-melt veins. Among these settings are complete olivine porphyritic chondrules. We encountered few sq...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Miyahara M,El Goresy A,Ohtani E,Nagase T,Nishijima M,Vashaei Z,Ferroir T,Gillet P,Dubrovinsky L,Simionovici A

更新日期：2008-06-24 00:00:00

abstract：:Listeriolysin O (LLO) is a cholesterol-dependent cytolysin that is an essential virulence factor of Listeria monocytogenes. LLO pore-forming activity is pH-dependent; it is active at acidic pH (<6), but not at neutral pH. In contrast to other pH-dependent toxins, we have determined that LLO pore-forming activity is co...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schuerch DW,Wilson-Kubalek EM,Tweten RK

更新日期：2005-08-30 00:00:00

abstract：:This paper shows that proteins display an unexpectedly wide range of behaviors in buffers containing moderate (0.1-10 mM) concentrations of SDS (complete unfolding, formation of stable intermediate states, specific association with SDS, and various kinetic phenomena); capillary electrophoresis provides a convenient me...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gudiksen KL,Gitlin I,Whitesides GM

更新日期：2006-05-23 00:00:00

abstract：:Cancer stem-like cells (CSCs) are a highly tumorigenic cell type present as a minority population in developmentally diverse tumors and cell lines. Using a genetic screen in an inducible model of CSC formation in a breast cell line, we identify microRNAs (miRNAs) that inhibit CSC growth and are down-regulated in CSCs....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Polytarchou C,Iliopoulos D,Struhl K

更新日期：2012-09-04 00:00:00