The spectrum of NGC 7027 (367-650 nm).

abstract：:We study the electrophoretic transport of single-stranded RNA molecules through 1.5-nm-wide pores of carbon nanotube membranes by molecular dynamics simulations. From approximately 170 individual RNA translocation events analyzed at full atomic resolution of solvent, membrane, and RNA, we identify key factors in membr...

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

authors： Yeh IC,Hummer G

更新日期：2004-08-17 00:00:00

abstract：:The productivity of aquatic ecosystems depends on the supply of limiting nutrients. The invasion of the Laurentian Great Lakes, the world's largest freshwater ecosystem, by dreissenid (zebra and quagga) mussels has dramatically altered the ecology of these lakes. A key open question is how dreissenids affect the cycli...

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

authors： Li J,Ianaiev V,Huff A,Zalusky J,Ozersky T,Katsev S

更新日期：2021-02-09 00:00:00

abstract：:A technique for systematic peptide variation by a combination of rational and evolutionary approaches is presented. The design scheme consists of five consecutive steps: (i) identification of a "seed peptide" with a desired activity, (ii) generation of variants selected from a physicochemical space around the seed pep...

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

authors： Schneider G,Schrödl W,Wallukat G,Müller J,Nissen E,Rönspeck W,Wrede P,Kunze R

更新日期：1998-10-13 00:00:00

abstract：:Fungi that are resistant or sensitive to the singlet oxygen-generating toxin cercosporin were assayed for their ability to detoxify it by reduction. Cercosporin reduction was assayed microscopically by using bandpass filters to differentiate between fluorescence emission from cercosporin and reduced cercosporin. Hypha...

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

authors： Daub ME,Leisman GB,Clark RA,Bowden EF

更新日期：1992-10-15 00:00:00

abstract：:Because mouse models play a crucial role in biomedical research related to the human nervous system, understanding the similarities and differences between mouse and human brain is of fundamental importance. Studies comparing transcription in human and mouse have come to varied conclusions, in part because of their re...

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

authors： Miller JA,Horvath S,Geschwind DH

更新日期：2010-07-13 00:00:00

abstract：:A form of two-dimensional (2D) vibrational spectroscopy, which uses two ultrafast IR laser pulses, is used to examine the structure of a cyclic penta-peptide in solution. Spectrally resolved cross peaks occur in the off-diagonal region of the 2D IR spectrum of the amide I region, analogous to those in 2D NMR spectrosc...

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

authors： Hamm P,Lim M,DeGrado WF,Hochstrasser RM

更新日期：1999-03-02 00:00:00

abstract：:Human activities have increased N availability dramatically in terrestrial and aquatic ecosystems. Extensive research demonstrates that local plant species diversity generally declines in response to nutrient enrichment, yet the mechanisms for this decline remain unclear. Based on an analysis of >900 species responses...

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

authors： Suding KN,Collins SL,Gough L,Clark C,Cleland EE,Gross KL,Milchunas DG,Pennings S

更新日期：2005-03-22 00:00:00

abstract：:English and Russian color terms divide the color spectrum differently. Unlike English, Russian makes an obligatory distinction between lighter blues ("goluboy") and darker blues ("siniy"). We investigated whether this linguistic difference leads to differences in color discrimination. We tested English and Russian spe...

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

authors： Winawer J,Witthoft N,Frank MC,Wu L,Wade AR,Boroditsky L

更新日期：2007-05-08 00:00:00

abstract：:Neuroinflammation is an important contributor to neuronal pathology and death in neurodegenerative diseases and neuronal injury. Therapeutic interventions blocking the activity of the inflammatory kinase IKKβ, a key regulator of neuroinflammatory pathways, is protective in several animal models of neurodegenerative di...

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

authors： Ochaba J,Fote G,Kachemov M,Thein S,Yeung SY,Lau AL,Hernandez S,Lim RG,Casale M,Neel MJ,Monuki ES,Reidling J,Housman DE,Thompson LM,Steffan JS

更新日期：2019-05-28 00:00:00

abstract：:The last 2 decades have seen discoveries in highly excited states of atoms and molecules of phenomena that are qualitatively different from the "planetary" model of the atom, and the near-rigid model of molecules, characteristic of these systems in their low-energy states. A unified view is emerging in terms of approx...

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

authors： Kellman ME

更新日期：1996-12-10 00:00:00

abstract：:Ferredoxin:NADP oxidoreductases (FNRs) constitute a family of flavoenzymes that catalyze the exchange of reducing equivalents between one-electron carriers and the two-electron-carrying NADP(H). The main role of FNRs in cyanobacteria and leaf plastids is to provide the NADPH for photoautotrophic metabolism. In root pl...

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

authors： Thomas JC,Ughy B,Lagoutte B,Ajlani G

更新日期：2006-11-28 00:00:00

abstract：:The three-dimensional structure of O,O',N-trimethyl-d-tubocurarine, a neuromuscular blocking agent, has been determined by x-ray crystallography. This may help to provide insight into its pharmacologic action. ...

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

authors： Sobell HM,Sakore TD,Tavale SS,Canepa FG,Pauling P,Petcher TJ

更新日期：1972-08-01 00:00:00

abstract：:Entropic effects have often been invoked to explain the extraordinary catalytic power of enzymes. In particular, the hypothesis that enzymes can use part of the substrate-binding free energy to reduce the entropic penalty associated with the subsequent chemical transformation has been very influential. The enzymatic r...

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

authors： Kazemi M,Himo F,Åqvist J

更新日期：2016-03-01 00:00:00

abstract：:Two mutations are described that alter the pattern of inheritance of chloroplast genes in Chlamydomonas. The mutant gene mat-1 linked to the mating type allele mt(-) greatly increases the frequency of exceptional zygotes, i.e., zygotes that transmit chloroplast genes from the mt(-) (male) parent. In some crosses, 80-9...

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

authors： Sager R,Ramanis Z

更新日期：1974-12-01 00:00:00

abstract：:Therapeutics for cerebral ischemia/hypoxia, which often results in ischemic stroke in humans, are a global unmet medical need. Here, we report that bryostatin-1, a highly potent protein kinase C (PKC) activator, interrupts pathophysiological molecular cascades and apoptosis triggered by cerebral ischemia/hypoxia, enha...

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

authors： Sun MK,Hongpaisan J,Alkon DL

更新日期：2009-08-25 00:00:00

abstract：:Deletion derivatives of the maize transposable element Activator (Ac) were constructed in vitro and inserted into a kanamycin resistance gene. These constructions were then introduced into tobacco protoplasts derived from plants previously transformed with Ac. The ability of each deletion derivative to excise was meas...

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

authors： Coupland G,Plum C,Chatterjee S,Post A,Starlinger P

更新日期：1989-12-01 00:00:00

abstract：:A number of recent studies have shown that iron dissolution in Fe-containing dust aerosol can be linked to source material (mineral or anthropogenic), mineralogy, and iron speciation. All of these factors need to be incorporated into atmospheric chemistry models if these models are to accurately predict the impact of ...

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

authors： Rubasinghege G,Lentz RW,Scherer MM,Grassian VH

更新日期：2010-04-13 00:00:00

abstract：:Kdo (3-deoxy-d-manno-oct-2-ulosonic acid) is an eight-carbon sugar mostly confined to Gram-negative bacteria. It is often involved in attaching surface polysaccharides to their lipid anchors. α-Kdo provides a bridge between lipid A and the core oligosaccharide in all bacterial LPSs, whereas an oligosaccharide of β-Kdo...

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

authors： Ovchinnikova OG,Mallette E,Koizumi A,Lowary TL,Kimber MS,Whitfield C

更新日期：2016-05-31 00:00:00

abstract：:Transposable elements make up half of the mammalian genome. One of the most abundant is the short interspersed nuclear element (SINE). Among their million copies, B2 accounts for ∼350,000 in the mouse genome and has garnered special interest because of emerging roles in epigenetic regulation. Our recent work demonstra...

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

authors： Hernandez AJ,Zovoilis A,Cifuentes-Rojas C,Han L,Bujisic B,Lee JT

更新日期：2020-01-07 00:00:00

abstract：:Histone methylation has an important role in transcriptional regulation. However, unlike H3K4 and H3K9 methylation, the role of H4K20 monomethylation (H4K20me-1) in transcriptional regulation remains unclear. Here, we show that Wnt3a specifically stimulates H4K20 monomethylation at the T cell factor (TCF)-binding elem...

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

authors： Li Z,Nie F,Wang S,Li L

更新日期：2011-02-22 00:00:00

abstract：:Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their charac...

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

authors： Frantz LAF,Haile J,Lin AT,Scheu A,Geörg C,Benecke N,Alexander M,Linderholm A,Mullin VE,Daly KG,Battista VM,Price M,Gron KJ,Alexandri P,Arbogast RM,Arbuckle B,Bӑlӑşescu A,Barnett R,Bartosiewicz L,Baryshnikov G,Bons

更新日期：2019-08-27 00:00:00

abstract：:It is becoming common practice to partition glass-forming liquids into two classes based on the dependence of the shear viscosity η on temperature T. In an Arrhenius plot, ln η vs 1/T, a strong liquid shows linear behavior whereas a fragile liquid exhibits an upward curvature [super-Arrhenius (SA) behavior], a situati...

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

authors： Mallamace F,Branca C,Corsaro C,Leone N,Spooren J,Chen SH,Stanley HE

更新日期：2010-12-28 00:00:00

abstract：:Glucose is a fundamental metabolite, yet how cells sense and respond to changes in extracellular glucose concentration is not completely understood. We recently reported that the MondoA:Mlx dimeric transcription factor directly regulates glycolysis. In this article, we consider whether MondoA:Mlx complexes have a broa...

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

authors： Stoltzman CA,Peterson CW,Breen KT,Muoio DM,Billin AN,Ayer DE

更新日期：2008-05-13 00:00:00

abstract：:Sonicated rabbit-liver chromatin is fractionated by ion-exchange chromatography on ECTHAM-cellulose, a weakly cationic adsorbent. The chromatographic procedure provides a series of fractions having a spectrum of thermal denaturation profiles. The earliest-eluting fractions melt cooperatively at a significantly higher ...

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

authors： Reeck GR,Simpson RT,Sober HA

更新日期：1972-08-01 00:00:00

abstract：:Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary ge...

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

authors： Arnold BJ,Lahner B,DaCosta JM,Weisman CM,Hollister JD,Salt DE,Bomblies K,Yant L

更新日期：2016-07-19 00:00:00

abstract：:Plant soil specialists contribute greatly to global diversity; however, the ecoevolutionary forces responsible for generating this diversity are poorly understood. We integrate molecular phylogenies with descriptive and experimental ecological data, creating a powerful framework with which to elucidate forces driving ...

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

authors： Cacho NI,Strauss SY

更新日期：2014-10-21 00:00:00

abstract：:Considerable effort has been directed toward controlling tuberculosis, which kills almost two million people yearly. High on the research agenda is the discovery of biomarkers of active tuberculosis (TB) for diagnosis and for monitoring treatment outcome. Rational biomarker discovery requires understanding host-pathog...

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

authors： Kunnath-Velayudhan S,Salamon H,Wang HY,Davidow AL,Molina DM,Huynh VT,Cirillo DM,Michel G,Talbot EA,Perkins MD,Felgner PL,Liang X,Gennaro ML

更新日期：2010-08-17 00:00:00

abstract：:Residues important in the interaction between the 23-residue transmembrane (TM) domains of the integrin alpha(IIb)- and beta(3)-subunits were identified by mutating each non-Leu residue to Leu. Leu substitutions of alpha(IIb) at G972, G976, and T981, and of beta(3) at I693 and G708, increased ligand binding. Substitut...

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

authors： Luo BH,Carman CV,Takagi J,Springer TA

更新日期：2005-03-08 00:00:00

abstract：:Habituation is a form of simple memory that suppresses neural activity in response to repeated, neutral stimuli. This process is critical in helping organisms guide attention toward the most salient and novel features in the environment. Here, we follow known circuit mechanisms in the fruit fly olfactory system to der...

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

authors： Shen Y,Dasgupta S,Navlakha S

更新日期：2020-06-02 00:00:00

abstract：:The synthesis of antiviral beta-chemokines has joined cytolysis as a potential mechanism for the control of HIV-1 infection by CD8(+) T cells. Recent evidence suggests that these two effector functions can diverge in some individuals infected with HIV-1; however, little is known about the CD8(+) T cell subsets in norm...

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

authors： Kamin-Lewis R,Abdelwahab SF,Trang C,Baker A,DeVico AL,Gallo RC,Lewis GK

更新日期：2001-07-31 00:00:00