Brief history of US debt limits before 1939.

abstract：:Understanding how institutional changes within academia may affect the overall potential of science requires a better quantitative representation of how careers evolve over time. Because knowledge spillovers, cumulative advantage, competition, and collaboration are distinctive features of the academic profession, both...

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

authors： Petersen AM,Riccaboni M,Stanley HE,Pammolli F

更新日期：2012-04-03 00:00:00

abstract：:Acute injury to the intestinal mucosa is a major dose-limiting complication of abdominal radiation therapy. We studied the role of the transcription factor NF-kappaB in protection against radiation-induced apoptosis in the intestinal epithelium in vivo. We use mice in which NF-kappaB signaling through IkappaB-kinase (...

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

authors： Egan LJ,Eckmann L,Greten FR,Chae S,Li ZW,Myhre GM,Robine S,Karin M,Kagnoff MF

更新日期：2004-02-24 00:00:00

abstract：:Neurons vary in their capacity to produce, store, and release neuropeptides packaged in dense-core vesicles (DCVs). Specifically, neurons used for cotransmission have terminals that contain few DCVs and many small synaptic vesicles, whereas neuroendocrine neuron terminals contain many DCVs. Although the mechanistic ba...

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

authors： Bulgari D,Zhou C,Hewes RS,Deitcher DL,Levitan ES

更新日期：2014-03-04 00:00:00

abstract：:The effects of phorbol 12-myristate 13-acetate (PMA), a potent activator of protein kinase C, on Na+ influx were investigated in cultured human foreskin fibroblasts (HSWP cells). We report here that in serum-deprived HSWP cells the addition of PMA alone has no significant effect on Na+ influx. However, the addition of...

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

authors： Vicentini LM,Villereal ML

更新日期：1985-12-01 00:00:00

abstract：:Efficient and reliable classification of visual stimuli requires that their representations reside a low-dimensional and, therefore, computationally manageable feature space. We investigated the ability of the human visual system to derive such representations from the sensory input-a highly nontrivial task, given the...

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

authors： Cutzu F,Edelman S

更新日期：1996-10-15 00:00:00

abstract：:We explored the conformational landscape of the proteinogenic amino acid serine [CH(2)OH CH(NH(2)) COOH] in the gas phase. Solid serine was vaporized by laser ablation, expanded in a supersonic jet, and characterized by Fourier transform microwave spectroscopy. In the isolation conditions of the jet there have been di...

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

authors： Blanco S,Sanz ME,López JC,Alonso JL

更新日期：2007-12-18 00:00:00

abstract：:We studied intracellular pH (pHi) regulation in the absence of HCO3- in single mesangial cells (MCs) with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(and -6)carboxyfluorescein. Our approach was to acid load the cells by an NH+4 prepulse and to monitor the subsequent pHi recovery. Previous work on MCs and other ce...

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

authors： Boyarsky G,Ganz MB,Cragoe EJ Jr,Boron WF

更新日期：1990-08-01 00:00:00

abstract：:The protein products of T4 bacteriophage genes 41, 43, 45, 44, and 62 have been purified to near homogeneity using an assay which measures their stimulation of DNA synthesis in a crude lysate of Escherichia coli cells in fected by an appropriate mutant phage. When all of these proteins and T4 gene 32 protein are incub...

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

authors： Morris CF,Sinha NK,Alberts BM

更新日期：1975-12-01 00:00:00

abstract：:The semidwarf phenotype has been extensively selected during modern crop breeding as an agronomically important trait. Introduction of the semidwarf gene, semi-dwarf1 (sd1), which encodes a gibberellin biosynthesis enzyme, made significant contributions to the "green revolution" in rice (Oryza sativa L.). Here we repo...

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

authors： Asano K,Yamasaki M,Takuno S,Miura K,Katagiri S,Ito T,Doi K,Wu J,Ebana K,Matsumoto T,Innan H,Kitano H,Ashikari M,Matsuoka M

更新日期：2011-07-05 00:00:00

abstract：:The multifunctional Creb-binding protein (CBP) protein plays a pivotal role in many critical cellular processes. Here we demonstrate that the bromodomain of CBP binds to histone H3 acetylated on lysine 56 (K56Ac) with higher affinity than to its other monoacetylated binding partners. We show that autoacetylation of CB...

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

authors： Das C,Roy S,Namjoshi S,Malarkey CS,Jones DN,Kutateladze TG,Churchill ME,Tyler JK

更新日期：2014-03-25 00:00:00

abstract：:We previously characterized a methionine aminopeptidase (EC 3.4.11.18; Met-AP1; also called peptidase M) in Saccharomyces cerevisiae, which differs from its prokaryotic homologues in that it (i) contains an N-terminal zinc-finger domain and (ii) does not produce lethality when disrupted, although it does slow growth d...

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

authors： Li X,Chang YH

更新日期：1995-12-19 00:00:00

abstract：:Respiratory cytochrome c has been found to be phosphorylated at tyrosine 97 in the postischemic brain upon neuroprotective insulin treatment, but how such posttranslational modification affects mitochondrial metabolism is unclear. Here, we report the structural features and functional behavior of a phosphomimetic cyto...

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

authors： Guerra-Castellano A,Díaz-Quintana A,Pérez-Mejías G,Elena-Real CA,González-Arzola K,García-Mauriño SM,De la Rosa MA,Díaz-Moreno I

更新日期：2018-07-31 00:00:00

abstract：:A 978-base-pair gene that encodes thymidylate synthase (TS; 5,10-methylenetetrahydrofolate:dUMP C-methyltransferase, EC 2.1.1.45) from Lactobacillus casei has been synthesized and inserted into Escherichia coli expression vectors. The DNA sequence contains 35 unique restriction sites that are located an average of 28 ...

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

authors： Climie S,Santi DV

更新日期：1990-01-01 00:00:00

abstract：:Production of mature erythrocytes requires multiple growth factors, but we do not know how their actions are coordinated. Here we show that erythroid progenitors from erythropoietin receptor (Epo-R)-/- fetal livers, infected in vitro with a retrovirus expressing the wild-type Epo-R, require addition of both Epo and st...

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

authors： Wu H,Klingmüller U,Acurio A,Hsiao JG,Lodish HF

更新日期：1997-03-04 00:00:00

abstract：:In maturing T lineage cells, the helix-loop-helix protein E47 has been shown to enforce a critical proliferation and developmental checkpoint commonly referred to as beta selection. To examine how E47 regulates cellular expansion and developmental progression, we have used an E2A-deficient lymphoma cell line and DNA m...

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

authors： Schwartz R,Engel I,Fallahi-Sichani M,Petrie HT,Murre C

更新日期：2006-06-27 00:00:00

abstract：:Synthetic radionuclides, such as the transuranic actinides plutonium, americium, and curium, present severe health threats as contaminants, and understanding the scope of the biochemical interactions involved in actinide transport is instrumental in managing human contamination. Here we show that siderocalin, a mammal...

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

authors： Allred BE,Rupert PB,Gauny SS,An DD,Ralston CY,Sturzbecher-Hoehne M,Strong RK,Abergel RJ

更新日期：2015-08-18 00:00:00

abstract：:Cells have evolved complex regulatory networks that reorganize gene expression patterns in response to changing environmental conditions. These changes often involve redundant mechanisms that affect various levels of gene expression. Here, we examine the consequences of enhanced mRNA degradation in the galactose utili...

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

authors： Baumgartner BL,Bennett MR,Ferry M,Johnson TL,Tsimring LS,Hasty J

更新日期：2011-12-27 00:00:00

abstract：:The DNA-binding domain of c-Myb consists of three homologous tandem repeats of 52 amino acids. The structure of the third (C-terminal) repeat obtained by NMR analysis has a conformation related to the helix-turn-helix motif. To identify the role of each repeat in the sequence recognition of DNA, we analyzed specific i...

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

authors： Tanikawa J,Yasukawa T,Enari M,Ogata K,Nishimura Y,Ishii S,Sarai A

更新日期：1993-10-15 00:00:00

abstract：:According to a current "RNA first" model for the origin of life, RNA emerged in some form on early Earth to become the first biopolymer to support Darwinism here. Threose nucleic acid (TNA) and other polyelectrolytes are also considered as the possible first Darwinian biopolymer(s). This model is being developed by re...

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

authors： Kim HJ,Benner SA

更新日期：2017-10-24 00:00:00

abstract：:The vacuolated lens (vl) mouse mutant causes congenital cataracts and neural tube defects (NTDs), with the NTDs being caused by abnormal neural fold apposition and fusion. Our positional cloning of vl indicates these phenotypes result from a deletion mutation in an uncharacterized orphan G protein-coupled receptor (GP...

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

authors： Matteson PG,Desai J,Korstanje R,Lazar G,Borsuk TE,Rollins J,Kadambi S,Joseph J,Rahman T,Wink J,Benayed R,Paigen B,Millonig JH

更新日期：2008-02-12 00:00:00

abstract：:Early events in the action of 17-beta-estradiol can be studied in soluble extracts of rat uterus by exposure of the estradiol-receptor protein to a DNA-cellulose matrix. After complexing with [(3)H]estradiol, the 4S receptor protein binds to the DNA, and it can be eluted with buffer of high ionic strength as a more ti...

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

authors： Yamamoto KR,Alberts BM

更新日期：1972-08-01 00:00:00

abstract：:Natural killer-22 (NK-22) cells are a human NK cell subset situated in mucosal-associated lymphoid tissues that specialize in IL-22 secretion in response to IL-23. Here we investigated the cytokine requirements for NK-22 cell expansion. IL-7 maintained the survival of NK-22 cells and IL-22 production in response to IL...

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

authors： Cella M,Otero K,Colonna M

更新日期：2010-06-15 00:00:00

abstract：:The generation of high levels of new catalytic activities on natural and artificial protein scaffolds is a major goal of enzyme engineering. Here, we used random mutagenesis and selection in vivo to establish a sugar isomerisation reaction on both a natural (beta alpha)(8)-barrel enzyme and a catalytically inert chime...

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

authors： Claren J,Malisi C,Höcker B,Sterner R

更新日期：2009-03-10 00:00:00

abstract：:Awareness that our planet is a self-supporting biosphere with sunlight as its major source of energy for life has resulted in a long-term historical fascination with the workings of self-supporting ecological systems. However, the studies of such systems have never entered the canon of ecological or evolutionary tools...

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

authors： Rillig MC,Antonovics J

更新日期：2019-06-04 00:00:00

abstract：:The exocytosis of AMPA receptors is a key step in long-term potentiation (LTP), yet the timing and location of exocytosis and the signaling pathways involved in exocytosis during synaptic plasticity are not fully understood. Here we combine two-photon uncaging with two-photon imaging of a fluorescent label of surface ...

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

authors： Patterson MA,Szatmari EM,Yasuda R

更新日期：2010-09-07 00:00:00

abstract：:Parasitic plants share a common anatomical feature, the haustorium. Haustoria enable both infection and nutrient transfer, which often leads to growth penalties for host plants and yield reduction in crop species. Haustoria also reciprocally transfer substances, such as RNA and proteins, from parasite to host, but the...

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

authors： Spallek T,Melnyk CW,Wakatake T,Zhang J,Sakamoto Y,Kiba T,Yoshida S,Matsunaga S,Sakakibara H,Shirasu K

更新日期：2017-05-16 00:00:00

abstract：:A hybrid bacteriophage, P420, was constructed in vitro; it contains part of bacteriophage P4 and a 3.6-kilobase derivative of plasmid ColE1. In Escherichia coli, the plasmid-phage hybrid can exist as a stable plasmid or can be packaged into infective bacteriophage particles. Replication of P420, directed by the ColE1 ...

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

authors： Kahn M,Helinski DR

更新日期：1978-05-01 00:00:00

abstract：:Truncation selection is known to be the most efficient form of directional selection. When this is modified so that the fitness increases linearly over a range of one or two standard deviations of the value of the selected character, the efficiency is reduced, but not greatly. When truncation selection is compared to ...

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

authors： Crow JF,Kimura M

更新日期：1979-01-01 00:00:00

abstract：:Multiplex assays, involving the simultaneous use of multiple circulating tumor DNA (ctDNA) markers, can improve the performance of liquid biopsies so that they are highly predictive of cancer recurrence. We have developed a single-tube methylation-specific quantitative PCR assay (mqMSP) that uses 10 different methylat...

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

authors： Jin S,Zhu D,Shao F,Chen S,Guo Y,Li K,Wang Y,Ding R,Gao L,Ma W,Lu T,Li D,Zhang Z,Cai S,Liang X,Song H,Ji L,Li J,Zheng Z,Jiang F,Wu X,Luan J,Zhang H,Yang Z,Cantor CR,Xu C,Ding C

更新日期：2021-02-02 00:00:00

abstract：:The earliest folding events in single-tryptophan mutants of RNase A were investigated by fluorescence measurements by using a combination of stopped-flow and continuous-flow mixing experiments covering the time range from 70 micros to 10 s. An ultrarapid double-jump mixing protocol was used to study refolding from an ...

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

authors： Welker E,Maki K,Shastry MC,Juminaga D,Bhat R,Scheraga HA,Roder H

更新日期：2004-12-21 00:00:00