Vocal imitation in zebra finches is inversely related to model abundance.

abstract：:Amyloid fibrils were concentrated from the kidney, thyroid, and peripheral nerve of six patients with familial amyloidotic polyneuropathy (FAP). The fibril concentrates were solubilized in 6 M guanidine.HCl and fractionated on Sephadex G-100 columns. The elution profile of all FAP amyloid fibril concentrates revealed ...

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

authors： Costa PP,Figueira AS,Bravo FR

更新日期：1978-09-01 00:00:00

abstract：:Mechanisms of bacterial pathogenesis have become an increasingly important subject as pathogens have become increasingly resistant to current antibiotics. The adhesion of microorganisms to the surface of host tissue is often a first step in pathogenesis and is a plausible target for new antiinfective agents. Examinati...

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

authors： Liang MN,Smith SP,Metallo SJ,Choi IS,Prentiss M,Whitesides GM

更新日期：2000-11-21 00:00:00

abstract：:There is significant variation in the reported magnitude and even the sign of [Formula: see text] shifts in thin polymer films with nominally the same chemistry, film thickness, and supporting substrate. The implicit assumption is that methods used to estimate [Formula: see text] in bulk materials are relevant for inf...

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

authors： Zhang W,Douglas JF,Starr FW

更新日期：2018-05-29 00:00:00

abstract：:The genomic RNA of the avian influenza A virus, fowl plague, was fractionated into eight species by electrophoresis in polyacrylamide-agarose gels containing 6 M urea. The separated 32P-labeled RNA species were characterized by digestion with RNase T1 and fractionation of the resulting oligonucleotides by two-dimensio...

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

authors： McGeoch D,Fellner P,Newton C

更新日期：1976-09-01 00:00:00

abstract：:We have studied the expression of simian virus 40 (SV40) specific tumor antigen (T-antigen) and viral RNA in SV40-transformed mouse 3T3 cells that are temperature-sensitive for the expression of the transformed phenotype (ts SV3T3). Although transformed by wild-type SV40, ts SV3T3 cells at 32 degrees behave like stand...

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

authors： Basilico C,Zouzias D

更新日期：1976-06-01 00:00:00

abstract：:We introduce Pathifier, an algorithm that infers pathway deregulation scores for each tumor sample on the basis of expression data. This score is determined, in a context-specific manner, for every particular dataset and type of cancer that is being investigated. The algorithm transforms gene-level information into pa...

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

authors： Drier Y,Sheffer M,Domany E

更新日期：2013-04-16 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：:The SOS-inducible ruvA and ruvB gene products of Escherichia coli are required for normal levels of genetic recombination and DNA repair. In vitro, RuvA protein interacts specifically with Holliday junctions and, together with RuvB (an ATPase), promotes their movement along DNA. This process, known as branch migration...

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

authors： Tsaneva IR,Müller B,West SC

更新日期：1993-02-15 00:00:00

abstract：:Rad51 is a core component of the eukaryotic homologous recombination machinery and is responsible for key mechanistic steps during strand invasion. Higher order oligomers of Rad51 display a remarkable degree of structural variation, forming rings, compressed filaments, and elongated filaments. It is unclear whether Ra...

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

authors： Robertson RB,Moses DN,Kwon Y,Chan P,Chi P,Klein H,Sung P,Greene EC

更新日期：2009-08-04 00:00:00

abstract：:IFN-gamma treatment of cells leads to tyrosine phosphorylation of signal transducer and activator of transcription (STAT) 1 followed by dimerization through a reciprocal Src homology 2-phosphotyrosine interaction near the -COOH end of each monomer, forming a parallel structure that accumulates in the nucleus to drive ...

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

authors： Zhong M,Henriksen MA,Takeuchi K,Schaefer O,Liu B,ten Hoeve J,Ren Z,Mao X,Chen X,Shuai K,Darnell JE Jr

更新日期：2005-03-15 00:00:00

abstract：:Normal rat kidney cells infected with a temperature-sensitive mutant (LA23) of Rous sarcoma virus exhibit the transformed phenotype when grown at 33 degrees and the normal phenotype at 39 degrees. We have previously shown [Ash, J.F., Vogt, P.K. & Singer, S.J. (1976) Proc. Natl. Acad. Sci. USA 73, 3603-3607] that the a...

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

authors： Carroll RC,Ash JF,Vogt PK,Singer SJ

更新日期：1978-10-01 00:00:00

abstract：:There are many sources of genetic diversity, ranging from programmed mutagenesis in antibody genes to random mutagenesis during species evolution or development of cancer. We propose that mutations in DNA sequence-specific transcription factors that target response elements (REs) in many genes can also provide for rap...

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

authors： Resnick MA,Inga A

更新日期：2003-08-19 00:00:00

abstract：:A major challenge of the 21st century is to produce more food for a growing population without increasing humanity's agricultural footprint. Urban food production may help to solve this challenge; however, little research has examined the productivity of urban farming systems. We investigated inputs and produce yields...

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

authors： McDougall R,Kristiansen P,Rader R

更新日期：2019-01-02 00:00:00

abstract：:On illuminating chloroplasts with "short-wavelength" monochromatic light that supports oxygen evolution, spectral evidence was obtained for a new photoreactive chloroplast component, provisionally designated C550, which shows a reversible decrease of absorbance with a maximum at 550 mmu. The light-induced absorbance c...

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

authors： Knaff DB,Arnon DI

更新日期：1969-07-01 00:00:00

abstract：:Tumor necrosis factor (TNF) is a macrophage product under active study as an anticancer drug. However, this agent can be very toxic and has been implicated in the pathogenesis of endotoxic shock. After intravenous injection of human recombinant TNF (4 micrograms/g), growing rats showed an unusual constellation of phys...

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

authors： Kettelhut IC,Fiers W,Goldberg AL

更新日期：1987-06-01 00:00:00

abstract：:The calcium-activated K(+) channel KCa3.1 plays an important role in T lymphocyte Ca(2+) signaling by helping to maintain a negative membrane potential, which provides an electrochemical gradient to drive Ca(2+) influx. To assess the role of KCa3.1 channels in lymphocyte activation in vivo, we studied T cell function ...

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

authors： Di L,Srivastava S,Zhdanova O,Ding Y,Li Z,Wulff H,Lafaille M,Skolnik EY

更新日期：2010-01-26 00:00:00

abstract：:Inhibition of protein synthesis in rabbit reticulocyte lysates by double-stranded RNA is caused by the inactivation of IF-3, an initiation factor required for the recycling of ribosomes and for their binding to messenger RNA. The evidence for this is that (i) the inhibition can be overcome by addition of exogenous If-...

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

authors： Kaempfer R,Kaufman J

更新日期：1973-04-01 00:00:00

abstract：:Increasing evidence suggests that amyloid polymorphism gives rise to different strains of amyloids with distinct toxicities and pathology-spreading properties. Validating this hypothesis is challenging due to a lack of tools and methods that allow for the direct characterization of amyloid polymorphism in hydrated and...

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

authors： Cendrowska U,Silva PJ,Ait-Bouziad N,Müller M,Guven ZP,Vieweg S,Chiki A,Radamaker L,Kumar ST,Fändrich M,Tavanti F,Menziani MC,Alexander-Katz A,Stellacci F,Lashuel HA

更新日期：2020-03-24 00:00:00

abstract：:In cerebellar granule neurons of neonatal rats micromolar concentrations of 7-chloro-3-methyl-3,4-dihydro-2H-1,2, 4-benzothiadiazine S,S-dioxide (IDRA-21) and cyclothiazide, two negative modulators of the spontaneous agonist-dependent rapid desensitization of alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA...

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

authors： Impagnatiello F,Oberto A,Longone P,Costa E,Guidotti A

更新日期：1997-06-24 00:00:00

abstract：:Global loss of DNA methylation has been known for decades as an epigenomic aberration associated with carcinogenesis and cancer progression. Loss of DNA methylation affects predominantly repetitive elements, which encompass >50% of the CpG dinucleotides present in the human genome. Because of the lack of an effective ...

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

authors： Xie H,Wang M,Bonaldo Mde F,Rajaram V,Stellpflug W,Smith C,Arndt K,Goldman S,Tomita T,Soares MB

更新日期：2010-04-13 00:00:00

abstract：:A protein of 87 kilodaltons (87 kDa) was previously identified as a major specific substrate for protein kinase C in neuronal and other tissues. We have now studied the effect of protein kinase C-catalyzed phosphorylation of this protein on its association with membranes in isolated nerve terminals (synaptosomes) from...

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

authors： Wang JK,Walaas SI,Sihra TS,Aderem A,Greengard P

更新日期：1989-04-01 00:00:00

abstract：:A principal goal of cancer nanomedicine is to deliver therapeutics effectively to cancer cells within solid tumors. However, there are a series of biological barriers that impede nanomedicine from reaching target cells. Here, we report a stimuli-responsive clustered nanoparticle to systematically overcome these multip...

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

authors： Li HJ,Du JZ,Du XJ,Xu CF,Sun CY,Wang HX,Cao ZT,Yang XZ,Zhu YH,Nie S,Wang J

更新日期：2016-04-12 00:00:00

abstract：:We are designing simple peptide ion channels as model systems for the study of the physical principles controlling conduction through ion-channel proteins. Here we report on an uncharged peptide, Ac-(Leu-Ser-Ser-Leu-Leu-Ser-Leu)3-CONH2, designed to form an aggregate of parallel, amphiphilic, membrane-spanning alpha-he...

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

authors： Kienker PK,DeGrado WF,Lear JD

更新日期：1994-05-24 00:00:00

abstract：:Calcium/phospholipid-dependent protein kinase (protein kinase C, PKC) has been suggested to play a role in the sensitivity of gamma-aminobutyrate type A (GABAA) receptors to ethanol. We tested a line of null mutant mice that lacks the gamma isoform of PKC (PKC gamma) to determine the role of this brain-specific isoenz...

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

authors： Harris RA,McQuilkin SJ,Paylor R,Abeliovich A,Tonegawa S,Wehner JM

更新日期：1995-04-25 00:00:00

abstract：:The activity-regulated cytoskeleton-associated protein (Arc) gene is a neural immediate early gene that is involved in synaptic downscaling and is robustly induced by prolonged wakefulness in rodent brains. Converging evidence has led to the hypothesis that wakefulness potentiates, and sleep reduces, synaptic strength...

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

authors： Suzuki A,Yanagisawa M,Greene RW

更新日期：2020-05-12 00:00:00

abstract：:Changes in the secondary structure of some dozen different proteins upon lyophilization of their aqueous solutions have been investigated by means of Fourier-transform infrared spectroscopy in the amide III band region. Dehydration markedly (but reversibly) alters the secondary structure of all the proteins studied, a...

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

authors： Griebenow K,Klibanov AM

更新日期：1995-11-21 00:00:00

abstract：:A serum-free culture of dissociated neurons from embryonic rat hippocampus has been established as a rapid and quantitative in vitro test system for neurotrophic signals in the mammalian brain. By means of this cell culture bioassay, a novel low molecular weight neurotrophic factor (NTF) could be identified. NTF is es...

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

authors： Müller HW,Beckh S,Seifert W

更新日期：1984-02-01 00:00:00

abstract：:Realizing the goal of the Paris Agreement to limit global warming to 2 °C by the end of this century will most likely require deployment of carbon-negative technologies. It is particularly important that China, as the world's top carbon emitter, avoids being locked into carbon-intensive, coal-fired power-generation te...

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

authors： Lu X,Cao L,Wang H,Peng W,Xing J,Wang S,Cai S,Shen B,Yang Q,Nielsen CP,McElroy MB

更新日期：2019-04-23 00:00:00

abstract：:An argument is presented in favor of the hypothesis that, bovine carboxypeptidases A and B fit by and large, the concept of homology on the levels of both amino acid sequence and three-dimensional structure. Two peptide sequences from carboxypeptidases A and B, comprising 46 amino acid residues, display structural hom...

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

authors： Bradshaw RA,Neurath H,Walsh KA

更新日期：1969-06-01 00:00:00

abstract：:The pineal organ of the lizard Anolis carolinensis can be maintained for up to 10 days in superfused organ culture. During this time it synthesizes and releases melatonin into the medium flowing slowly over it. Collection of timed aliquots of medium and subsequent analysis for melatonin by radioimmunoassay reveal circ...

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

authors： Menaker M,Wisner S

更新日期：1983-10-01 00:00:00