Overview of imaging science.

abstract：:This work explores the concept that differential wave function overlap between excited states can be engineered within a molecular chromophore. The aim is to control excited state wave function symmetries, so that symmetry matches or mismatches result in differential orbital overlap and define low-energy trajectories ...

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

authors： Oviedo PS,Baraldo LM,Cadranel A

更新日期：2021-01-26 00:00:00

abstract：:Intermolecular electronic coupling dictates the optical properties of molecular aggregate systems. Of particular interest are photosynthetic pigment-protein complexes that absorb sunlight then efficiently direct energy toward the photosynthetic reaction center. Two-dimensional (2D) ultrafast spectroscopy has been used...

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

authors： Read EL,Engel GS,Calhoun TR,Mancal T,Ahn TK,Blankenship RE,Fleming GR

更新日期：2007-09-04 00:00:00

abstract：:Crises in science concern not only methods, statistics, and results but also, theory development. Beyond the indispensable refinement of tools and procedures, resolving crises would also benefit from a deeper understanding of the concepts and processes guiding research. Usually, theories compete, and some lose, incent...

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

authors： Ellemers N,Fiske ST,Abele AE,Koch A,Yzerbyt V

更新日期：2020-04-07 00:00:00

abstract：:The molecular mechanism by which the homodimeric enzyme Cu/Zn superoxide dismutase (SOD) causes neural damage in amytrophic lateral sclerosis is yet poorly understood. A striking, as well as an unusual, feature of SOD is that it maintains intrasubunit disulfide bonds in the reducing environment of the cytosol. Here, w...

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

authors： Lindberg MJ,Normark J,Holmgren A,Oliveberg M

更新日期：2004-11-09 00:00:00

abstract：:Little is known about the large ectodomain of MET, the product of the c-met protooncogene and receptor for hepatocyte growth factor/scatter factor (HGF/SF). Here, we establish by deletion mutagenesis that the HGF/SF and heparin-binding sites of MET are contained within a large N-terminal domain spanning the alpha-chai...

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

authors： Gherardi E,Youles ME,Miguel RN,Blundell TL,Iamele L,Gough J,Bandyopadhyay A,Hartmann G,Butler PJ

更新日期：2003-10-14 00:00:00

abstract：:All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O(6)-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O(6)-methylguanine (O(6)MeG) and O(6)-chloroethylguanine (O(6)CEG) specifically initiate apoptosis in...

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

authors： Hickman MJ,Samson LD

更新日期：1999-09-14 00:00:00

abstract：:A population of procollagen molecules has been isolated from the culture medium of a clonal line of calf dermatosparactic cells and shown to have the amino-acid composition, physical properties, and molecular structure consistent with collagen precursors. Although this procollagen population shares immunologic determi...

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

authors： Tanzer ML,Church RL,Yaeger JA,Wampler DE,Park E

更新日期：1974-08-01 00:00:00

abstract：:Protein tyrosine phosphorylation in purified synaptic vesicles from rat forebrain has been studied in the presence of Mn2+ and orthovanadate. High levels of endogenous protein tyrosine phosphorylation were observed. Four major phosphoproteins, with apparent molecular masses of 105, 94, 38, and 30 kDa, were shown to co...

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

authors： Pang DT,Wang JK,Valtorta F,Benfenati F,Greengard P

更新日期：1988-02-01 00:00:00

abstract：:The N-terminal domain of HIV-1 integrase contains a pair of His and Cys residues (the HHCC motif) that are conserved among retroviral integrases. Although His and Cys residues are often involved in binding zinc, the HHCC motif does not correspond to any recognized class of zinc binding domain. We have investigated the...

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

authors： Zheng R,Jenkins TM,Craigie R

更新日期：1996-11-26 00:00:00

abstract：:In autotrophically grown Chlorella cells, glucose induces a hexose transport system but, at the same time, the synthesis of two amino acid transport systems is also induced. Thus, the rates of uptake of glycine, L-alanine, L-proline, and L-serine, all of which compete with each other for entry into the cells, increase...

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

authors： Cho BH,Sauer N,Komor E,Tanner W

更新日期：1981-06-01 00:00:00

abstract：:Granulocyte-colony-stimulating factor (G-CSF) stimulates the proliferation and differentiation of cells of the neutrophil lineage by interaction with a specific receptor. Early signal transduction events following G-CSF receptor activation were studied. We detected tyrosine phosphorylation of both the G-CSF receptor a...

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

authors： Nicholson SE,Oates AC,Harpur AG,Ziemiecki A,Wilks AF,Layton JE

更新日期：1994-04-12 00:00:00

abstract：:The ability of lysosomes to move within the cytoplasm is important for many cellular functions. This ability is particularly critical in neurons, which comprise vast, highly differentiated domains such as the axon and dendrites. The mechanisms that control lysosome movement in these domains, however, remain poorly und...

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

authors： Farías GG,Guardia CM,De Pace R,Britt DJ,Bonifacino JS

更新日期：2017-04-04 00:00:00

abstract：:By the use of a rapid radioautographic screening procedure, two mutants of Bacillus brevis ATCC 8185 that have lost the ability to produce gramicidin have been isolated. These mutants produced normal levels of tyrocidine and sporulated at the same frequency as the parent strain. Their spores, however, were more heat-s...

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

authors： Mukherjee PK,Paulus H

更新日期：1977-02-01 00:00:00

abstract：:In the presence but not in the absence of pokeweed mitogen (PWM), monoclonal antibodies against HLA-DR antigens 147 and 164 helped highly purified B lymphocytes to proliferate and mature to Ig-secreting cells. In contrast, neither anti-DR antibody 231 nor the UCHT1 monoclonal anti-human T cell antibody (both of the sa...

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

authors： Palacios R,Martinez-Maza O,Guy K

更新日期：1983-06-01 00:00:00

abstract：:The mannose receptor (MR) is an endocytic receptor involved in serum homeostasis and antigen presentation. Here, we identify the MR as a direct regulator of CD8(+) T-cell activity. We demonstrate that MR expression on dendritic cells (DCs) impaired T-cell cytotoxicity in vitro and in vivo. This regulatory effect of th...

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

authors： Schuette V,Embgenbroich M,Ulas T,Welz M,Schulte-Schrepping J,Draffehn AM,Quast T,Koch K,Nehring M,König J,Zweynert A,Harms FL,Steiner N,Limmer A,Förster I,Berberich-Siebelt F,Knolle PA,Wohlleber D,Kolanus W,Beyer M

更新日期：2016-09-20 00:00:00

abstract：:We construct a C*-algebra that has only one irreducible representation up to unitary equivalence but is not isomorphic to the algebra of compact operators on any Hilbert space. This answers an old question of Naimark. Our construction uses a combinatorial statement called the diamond principle, which is known to be co...

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

authors： Akemann C,Weaver N

更新日期：2004-05-18 00:00:00

abstract：:An ADP analog carrying a biotin moiety and a photoreactive group was synthesized. In the presence of vanadate ion (Vi), the analog was tightly trapped into the ATPase site of heavy meromyosin (HMM) or myosin subfragment 1 (S1) in an ADP analog/ATPase site molar ratio of 1:1. UV illumination on the HMM (or S1)-Vi-ADP a...

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

authors： Sutoh K,Yamamoto K,Wakabayashi T

更新日期：1986-01-01 00:00:00

abstract：:The Fas/APO-1 cytotoxic pathway plays an important role in the regulation of peripheral immunity. Recent evidence indicates that this regulatory function operates through deletion of activated T and B lymphocytes by CD4+ T cells expressing the Fas ligand. Because macrophages play a key role in peripheral immunity, we ...

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

authors： Ashany D,Song X,Lacy E,Nikolic-Zugic J,Friedman SM,Elkon KB

更新日期：1995-11-21 00:00:00

abstract：:The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) is a transcriptional coactivator that controls expression of metabolic/energetic genes, programming cellular responses to nutrient and environmental adaptations such as fasting, cold, or exercise. Unlike other coactivators, PGC-1α contai...

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

authors： Tavares CDJ,Aigner S,Sharabi K,Sathe S,Mutlu B,Yeo GW,Puigserver P

更新日期：2020-09-08 00:00:00

abstract：:The primary structure and phosphorylation pattern of the tandem Y(1)S(2)P(3)T(4)S(5)P(6)S(7) repeats of the RNA polymerase II carboxyl-terminal domain (CTD) convey information about the transcription apparatus--a CTD code--to a large ensemble of CTD-binding receptor proteins. Four of the seven coding "letters" of the ...

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

authors： Schwer B,Sanchez AM,Shuman S

更新日期：2012-10-30 00:00:00

abstract：:The initiator RNAs of mammalian Okazaki fragments are thought to be removed by RNase HI and the 5'-3' flap endonuclease (FEN1). Earlier evidence indicated that the cleavage site of RNase HI is 5' of the last ribonucleotide at the RNA-DNA junction on an Okazaki substrate. In current work, highly purified calf RNase HI ...

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

authors： Murante RS,Henricksen LA,Bambara RA

更新日期：1998-03-03 00:00:00

abstract：:In aqueous solution, aldehydes, and to a lesser extent ketones, hydrate to form geminal diols. We investigate the hydration of methylglyoxal (MG) in the gas phase, a process not previously considered to occur in water-restricted environments. In this study, we spectroscopically identified methylglyoxal diol (MGD) and ...

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

authors： Axson JL,Takahashi K,De Haan DO,Vaida V

更新日期：2010-04-13 00:00:00

abstract：:The CRR1 (Copper Response Regulator) locus, required for both activating and repressing target genes of a copper- and hypoxia-sensing pathway in Chlamydomonas, encodes a 1,232-residue candidate transcription factor with a plant-specific DNA-binding domain named SBP, ankyrin repeats, and a C-terminal Cys-rich region, w...

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

authors： Kropat J,Tottey S,Birkenbihl RP,Depège N,Huijser P,Merchant S

更新日期：2005-12-20 00:00:00

abstract：:X-ray structures of bovine heart cytochrome c oxidase have suggested that the enzyme, which reduces O(2) in a process coupled with a proton pumping process, contains a proton pumping pathway (H-pathway) composed of a hydrogen bond network and a water channel located in tandem across the enzyme. The hydrogen bond netwo...

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

authors： Shimokata K,Katayama Y,Murayama H,Suematsu M,Tsukihara T,Muramoto K,Aoyama H,Yoshikawa S,Shimada H

更新日期：2007-03-06 00:00:00

abstract：:Whereas amyloid-β (Aβ) accumulates in the brain of normal animals dosed with low levels of copper (Cu), the mechanism is not completely known. Cu could contribute to Aβ accumulation by altering its clearance and/or its production. Because Cu homeostasis is altered in transgenic mice overexpressing Aβ precursor protein...

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

authors： Singh I,Sagare AP,Coma M,Perlmutter D,Gelein R,Bell RD,Deane RJ,Zhong E,Parisi M,Ciszewski J,Kasper RT,Deane R

更新日期：2013-09-03 00:00:00

abstract：:The molecular mechanisms linking glucose metabolism with active transcription remain undercharacterized in mammalian cells. Using nuclear factor-κB (NF-κB) as a glucose-responsive transcription factor, we show that cells use the hexosamine biosynthesis pathway and O-linked β-N-acetylglucosamine (O-GlcNAc) transferase ...

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

authors： Allison DF,Wamsley JJ,Kumar M,Li D,Gray LG,Hart GW,Jones DR,Mayo MW

更新日期：2012-10-16 00:00:00

abstract：:A revelation of the genomic age has been the contributions of the mobile DNA segments called transposable elements to chromosome structure, function, and evolution in virtually all organisms. Substantial fractions of vertebrate genomes derive from transposable elements, being dominated by retroelements that move via R...

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

authors： Mitra R,Li X,Kapusta A,Mayhew D,Mitra RD,Feschotte C,Craig NL

更新日期：2013-01-02 00:00:00

abstract：:Mesp2 is a transcription factor that plays fundamental roles in somitogenesis, and its expression is strictly restricted to the anterior presomitic mesoderm just before segment border formation. The transcriptional on-off cycle is linked to the segmentation clock. In our current study, we show that a T-box transcripti...

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

authors： Yasuhiko Y,Haraguchi S,Kitajima S,Takahashi Y,Kanno J,Saga Y

更新日期：2006-03-07 00:00:00

abstract：:RNase T2 enzymes are conserved in most eukaryotic genomes, and expression patterns and phylogenetic analyses suggest that they may carry out an important housekeeping role. However, the nature of this role has been elusive. Here we show that RNS2, an intracellular RNase T2 from Arabidopsis thaliana, is essential for n...

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

authors： Hillwig MS,Contento AL,Meyer A,Ebany D,Bassham DC,Macintosh GC

更新日期：2011-01-18 00:00:00

abstract：:cDNA array technology has proven to be a powerful way to monitor global changes in gene expression patterns. Here, we present an approach that extends the current utility of cDNA arrays to allow the evaluation of the relative roles of transcription and mRNA turnover in governing gene expression on a global basis, comp...

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

authors： Fan J,Yang X,Wang W,Wood WH 3rd,Becker KG,Gorospe M

更新日期：2002-08-06 00:00:00