Heme compounds in dinosaur trabecular bone.

abstract：:High-resolution analyses of a late Holocene core from Kettle Lake in North Dakota reveal coeval fluctuations in loss-on-ignition carbonate content, percentage of grass pollen, and charcoal flux. These oscillations are indicative of climate-fuel-fire cycles that have prevailed on the Northern Great Plains (NGP) for mos...

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

authors： Brown KJ,Clark JS,Grimm EC,Donovan JJ,Mueller PG,Hansen BC,Stefanova I

更新日期：2005-06-21 00:00:00

abstract：:The oxazolidinones represent the first new class of antibiotics to enter into clinical usage within the past 30 years, but their binding site and mechanism of action has not been fully characterized. We have determined the crystal structure of the oxazolidinone linezolid bound to the Deinococcus radiodurans 50S riboso...

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

authors： Wilson DN,Schluenzen F,Harms JM,Starosta AL,Connell SR,Fucini P

更新日期：2008-09-09 00:00:00

abstract：:Vitamin A signals play critical roles during embryonic development. In particular, heart morphogenesis depends on vitamin A signals mediated by the retinoid X receptor alpha (RXRalpha), as the systemic mutation of this receptor results in thinning of the myocardium and embryonic lethality. However, the molecular and c...

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

authors： Merki E,Zamora M,Raya A,Kawakami Y,Wang J,Zhang X,Burch J,Kubalak SW,Kaliman P,Izpisua Belmonte JC,Chien KR,Ruiz-Lozano P

更新日期：2005-12-20 00:00:00

abstract：:The oligodendrocyte (Od), a glial cell that produces myelin in the central nervous system, may be a target for autoreactive T cells in autoimmune demyelinating processes, although not expressing major histocompatibility complex (MHC) products. To analyze Od-T-cell interactions, we selected from normal SJL/J mouse sple...

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

authors： Jewtoukoff V,Lebar R,Bach MA

更新日期：1989-04-01 00:00:00

abstract：:In skeletal muscle, dihydropyridine receptors are functionally coupled to ryanodine receptors of the sarcoplasmic reticulum in triadic or diadic junctional complexes. In cardiac muscle direct physical or functional couplings have not been demonstrated. We have tested the hypothesis of functional coupling of L-type Ca2...

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

authors： Sham JS,Cleemann L,Morad M

更新日期：1995-01-03 00:00:00

abstract：:The core structures of many viruses move within cells by association with host cytoskeletal motor proteins; however, the mechanisms by which intracellular viral particles are transported toward sites of replication or the cell periphery at distinct stages of infection remain to be understood. The regulation of herpesv...

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

authors： Smith GA,Pomeranz L,Gross SP,Enquist LW

更新日期：2004-11-09 00:00:00

abstract：:We have obtained the resonance Raman spectrum of bacteriorhodopsin's primary photoproduct K with a novel low-temperature spinning sample technique. Purple membrane at 77 K is illuminated with spatially separated actinic (pump) and probe laser beams. The 514-nm pump beam produces a photostationary steady-state mixture ...

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

authors： Braiman M,Mathies R

更新日期：1982-01-01 00:00:00

abstract：:Activation of class II gene transcription may involve alleviation of transcription repression as well as stimulation of the assembly and function of the general RNA polymerase (RNAP) II transcription machinery. Here, we investigated whether activator-reversible transcription repression by NC2 (Dr1/DRAP1) contributes t...

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

authors： Castaño E,Gross P,Wang Z,Roeder RG,Oelgeschläger T

更新日期：2000-06-20 00:00:00

abstract：:Previous research and theory suggest that two stable personality dimensions, extroversion and neuroticism, differentially influence emotional reactivity to a variety of pleasurable phenomena. Here, we use event-related functional MRI to address the putative neural and behavioral associations between humor appreciation...

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

authors： Mobbs D,Hagan CC,Azim E,Menon V,Reiss AL

更新日期：2005-11-08 00:00:00

abstract：:The long QT syndrome (LQTS) is a heritable disorder that predisposes to sudden cardiac death. LQTS is caused by mutations in ion channel genes including HERG and KCNE1, but the precise mechanisms remain unclear. To clarify this situation we injected adenoviral vectors expressing wild-type or LQT mutants of HERG and KC...

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

authors： Hoppe UC,Marbán E,Johns DC

更新日期：2001-04-24 00:00:00

abstract：:The outcome of exposure to infectious microbes or their toxins is influenced by both microbial and host genes. Some host genes encode defense mechanisms, whereas others assist pathogen functions. Genomic analyses have associated host gene mutations with altered infectious disease susceptibility, but evidence for causa...

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

authors： Martchenko M,Candille SI,Tang H,Cohen SN

更新日期：2012-02-21 00:00:00

abstract：:The high concentration of gonadotropin-releasing hormone (GnRH) in milk of several species implies that the mammary gland is either a site of synthesis for this neuropeptide or that it is efficiently concentrated from plasma by this organ. By PCR amplification of mammary gland cDNA, we have demonstrated expression of ...

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

authors： Palmon A,Ben Aroya N,Tel-Or S,Burstein Y,Fridkin M,Koch Y

更新日期：1994-05-24 00:00:00

abstract：:Despite substantial size variations, proportions of the developing body plan are maintained with a remarkable precision. Little is known about the mechanisms that ensure this adaptation (scaling) of pattern with size. Most models of patterning by morphogen gradients do not support scaling. In contrast, we show that sc...

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

authors： Ben-Zvi D,Barkai N

更新日期：2010-04-13 00:00:00

abstract：:Phospholipid flippases (P4-ATPases) utilize ATP to translocate specific phospholipids from the exoplasmic leaflet to the cytoplasmic leaflet of biological membranes, thus generating and maintaining transmembrane lipid asymmetry essential for a variety of cellular processes. P4-ATPases belong to the P-type ATPase prote...

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

authors： Tadini-Buoninsegni F,Mikkelsen SA,Mogensen LS,Molday RS,Andersen JP

更新日期：2019-08-13 00:00:00

abstract：:An analysis of taxonomic longevity for species of the two Cenozoic radiations of Caribbean planktonic foraminifera shows strong similarity in longevity for extinct taxa, though extant species of the latter radiation are biased towards longer-lived forms. In this case, the present is not the key to the past. A simple o...

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

authors： Levinton JS,Ginzburg L

更新日期：1984-09-01 00:00:00

abstract：:Tramadol, previously only known as a synthetic analgesic, has now been found in the bark and wood of roots of the African medicinal tree Nauclea latifolia. At present, no direct evidence is available as to the biosynthetic pathway of its unusual skeleton. To provide guidance as to possible biosynthetic precursors, we ...

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

authors： Romek KM,Nun P,Remaud GS,Silvestre V,Taïwe GS,Lecerf-Schmidt F,Boumendjel A,De Waard M,Robins RJ

更新日期：2015-07-07 00:00:00

abstract：:Oxidants, such as those generated by metabolically activated phagocytes in inflammation, have been implicated in the metabolic activation of carcinogens, and in this study we demonstrate that the interaction of (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-dihydrodiol) with phorbol ester-stimulated polym...

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

authors： Trush MA,Seed JL,Kensler TW

更新日期：1985-08-01 00:00:00

abstract：:CD45, a protein tyrosine phosphatase that regulates Src family kinases, is important for regulating T cell and B cell receptor signaling; however, little is known about how CD45 regulates immunoreceptor tyrosine-based activation motif (ITAM)-dependent natural killer (NK) cell receptor signaling and the resulting effec...

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

authors： Hesslein DG,Takaki R,Hermiston ML,Weiss A,Lanier LL

更新日期：2006-05-02 00:00:00

abstract：:The Bam complex assembles β-barrel proteins into the outer membrane (OM) of Gram-negative bacteria. These proteins comprise cylindrical β-sheets with long extracellular loops and create pores to allow passage of nutrients and waste products across the membrane. Despite their functional importance, several questions re...

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

authors： Wzorek JS,Lee J,Tomasek D,Hagan CL,Kahne DE

更新日期：2017-03-07 00:00:00

abstract：:Selective therapeutics for nuclear receptors would revolutionize treatment for endocrine disease. Specific control of nuclear receptor activity is challenging because the internal cavities that bind hormones can be virtually identical. Only one highly selective hormone analog is known for the thyroid receptor, GC-24, ...

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

authors： Borngraeber S,Budny MJ,Chiellini G,Cunha-Lima ST,Togashi M,Webb P,Baxter JD,Scanlan TS,Fletterick RJ

更新日期：2003-12-23 00:00:00

abstract：:In the face of antibiotics, bacterial populations avoid extinction by harboring a subpopulation of dormant cells that are largely drug insensitive. This phenomenon, termed "persistence," is a major obstacle for the treatment of a number of infectious diseases. The mechanism that generates both actively growing as well...

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

authors： Rotem E,Loinger A,Ronin I,Levin-Reisman I,Gabay C,Shoresh N,Biham O,Balaban NQ

更新日期：2010-07-13 00:00:00

abstract：:We report measurements of the geometrical structure and temporal evolution of metastable helical intermediates in the pathway for cholesterol crystallization in native and model biles. We find that the lecithin component in the bile can dramatically affect the kinetics along this pathway. We also present a theoretical...

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

authors： Chung DS,Benedek GB,Konikoff FM,Donovan JM

更新日期：1993-12-01 00:00:00

abstract：:The involvement of p53 in regulating diverse cellular processes dictates that it must respond to multiple signaling mechanisms, thus coordinating the response to various "stress conditions." Genotoxic stress has served as a paradigm to dissect the transactivation-dependent branch of the pathway by which p53 can induce...

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

authors： Ruaro EM,Collavin L,Del Sal G,Haffner R,Oren M,Levine AJ,Schneider C

更新日期：1997-04-29 00:00:00

abstract：:The interactions between products of the 15-lipoxygenase cascade and human natural killer (NK) cell activity have been studied. Addition of human leukocyte-derived (14R,15S)-14,15-dihydroxy-5Z,8Z,10E,12E-ic osatetraenoic acid (14,15-DiHETE) to the NK cytotoxicity assay against K562 target cells resulted in inhibition ...

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

authors： Ramstedt U,Serhan CN,Lundberg U,Wigzell H,Samuelsson B

更新日期：1984-11-01 00:00:00

abstract：:The structure of Sindbis virus was determined by electron cryomicroscopy. The virion contains two icosahedral shells of viral-encoded proteins separated by a membrane bilayer of cellular origin. The three-dimensional structure of the ice-embedded intact Sindbis virus, reconstructed from electron images, unambiguously ...

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

authors： Paredes AM,Brown DT,Rothnagel R,Chiu W,Schoepp RJ,Johnston RE,Prasad BV

更新日期：1993-10-01 00:00:00

abstract：:The rate of Cl- secretion by human airway epithelium is determined, in part, by apical cell membrane Cl- conductance. In cystic fibrosis airway epithelia, defective regulation of Cl- conductance decreases the capability to secrete Cl-. Here we report that extracytosolic ATP in the luminal bath of cultured human airway...

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

authors： Stutts MJ,Chinet TC,Mason SJ,Fullton JM,Clarke LL,Boucher RC

更新日期：1992-03-01 00:00:00

abstract：:The redox potentials of electron transfer proteins vary over a wide range, even when the type of redox center is the same. Rees [Proc. Natl. Acad. Sci. USA (1985) 82, 3082-3085] proposed that this variation of redox potential partly reflects the different net charges of the proteins, and he presented a linear correlat...

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

authors： Moore GR,Pettigrew GW,Rogers NK

更新日期：1986-07-01 00:00:00

abstract：:Cigarette smoke is the major cause of lung cancer, the leading cause of cancer death, and of chronic obstructive pulmonary disease, the fourth leading cause of death in the United States. Using high-density gene expression arrays, we describe genes that are normally expressed in a subset of human airway epithelial cel...

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

authors： Spira A,Beane J,Shah V,Liu G,Schembri F,Yang X,Palma J,Brody JS

更新日期：2004-07-06 00:00:00

abstract：:Precise regulation of the evolutionarily conserved hypoxia-inducible transcription factor (HIF) ensures proper adaptation to variations in oxygen availability throughout development and into adulthood. Oxygen-dependent regulation of HIF stability and activity are mediated by hydroxylation of conserved proline and aspa...

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

authors： Dann CE 3rd,Bruick RK,Deisenhofer J

更新日期：2002-11-26 00:00:00

abstract：:Mouse lymphocytic cells of the established line GF-14 were allowed to accumulate intracellular 3H-labeled aminoisobutyric acid (AIB), frozen, and stored over liquid N2. After internal radiation had reduced survival to 1 in 10(4), survivors were plated and tested for their ability to transport AIB. Out of 200 clones te...

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

authors： Finkelstein MC,Slayman CW,Adelberg EA

更新日期：1977-10-01 00:00:00