Dry granular flows can generate surface features resembling those seen in Martian gullies.

abstract：:Neurotrophins are essential for neuronal differentiation, but the onset and the intensity of neurotrophin signaling within the neuronal microenvironment are poorly understood. We tested the hypothesis that extracellular nucleotides and their cognate receptors regulate neurotrophin-mediated differentiation. We found th...

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

authors： Arthur DB,Akassoglou K,Insel PA

更新日期：2005-12-27 00:00:00

abstract：:Gastrointestinal infections often induce epithelial damage that must be repaired for optimal gut function. While intestinal stem cells are critical for this regeneration process [R. C. van der Wath, B. S. Gardiner, A. W. Burgess, D. W. Smith, PLoS One 8, e73204 (2013); S. Kozar et al., Cell Stem Cell 13, 626-633 (2013...

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

authors： Mileto SJ,Jardé T,Childress KO,Jensen JL,Rogers AP,Kerr G,Hutton ML,Sheedlo MJ,Bloch SC,Shupe JA,Horvay K,Flores T,Engel R,Wilkins S,McMurrick PJ,Lacy DB,Abud HE,Lyras D

更新日期：2020-04-07 00:00:00

abstract：:We prove that the property of excision in algebraic K-theory is for a Q-algebra A equivalent to the H-unitality of the latter. Our excision theorem, in particular, implies Karoubi's conjecture on the equality of algebraic and topological K-theory groups of stable C*-algebras. It also allows us to identify the algebrai...

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

authors： Suslin AA,Wodzicki M

更新日期：1990-12-15 00:00:00

abstract：:We recently reported the hemochromatosis-like phenotype observed in our Usf2 knockout mice. In these mice, as in murine models of hemochromatosis and patients with hereditary hemochromatosis, iron accumulates in parenchymal cells (in particular, liver and pancreas), whereas the reticuloendothelial system is spared fro...

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

authors： Nicolas G,Bennoun M,Porteu A,Mativet S,Beaumont C,Grandchamp B,Sirito M,Sawadogo M,Kahn A,Vaulont S

更新日期：2002-04-02 00:00:00

abstract：:Methylation on lysine 9 of histone H3 (H3K9me) and DNA methylation play important roles in the transcriptional silencing of specific genes and repetitive elements. Both marks are detected on class I and II endogenous retroviruses (ERVs) in murine embryonic stem cells (mESCs). Recently, we reported that the H3K9-specif...

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

authors： Leung DC,Dong KB,Maksakova IA,Goyal P,Appanah R,Lee S,Tachibana M,Shinkai Y,Lehnertz B,Mager DL,Rossi F,Lorincz MC

更新日期：2011-04-05 00:00:00

abstract：:In earlier studies it was shown that the mammalian translation system is highly organized in vivo and that the intermediates in the process, aminoacyl-tRNAs, are channeled--i.e., they are directly transferred from the aminoacyl-tRNA synthetases to the elongation factor to the ribosomes without dissociating into the ce...

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

authors： Stapulionis R,Deutscher MP

更新日期：1995-08-01 00:00:00

abstract：:We have investigated the biochemical basis for negative regulation of interleukin 2 receptor alpha-chain (IL-2R alpha) gene expression. Transient transfection studies employing internally deleted forms of the IL-2R alpha promoter localized a negative regulatory element (NRE) between nucleotides -400 and -368 relative ...

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

authors： Smith MR,Greene WC

更新日期：1989-11-01 00:00:00

abstract：:It is unknown whether cross-regulatory interactions between homeotic genes, which have been shown to play an important role in the maintenance of their expression domains during Drosophila development, are also important during mammalian development. We have analyzed here the expression of Hox genes in Hoxa-1 (Hox-1.6...

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

authors： Dollé P,Lufkin T,Krumlauf R,Mark M,Duboule D,Chambon P

更新日期：1993-08-15 00:00:00

abstract：:Sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose) is the polar head group of the plant sulfolipid SQ-diacylglycerol, and SQ comprises a major proportion of the organosulfur in nature, where it is degraded by bacteria. A first degradation pathway for SQ has been demonstrated recently, a "sulfoglycolytic" pathway, in addition...

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

authors： Felux AK,Spiteller D,Klebensberger J,Schleheck D

更新日期：2015-08-04 00:00:00

abstract：:Nuclear spin relaxation is a powerful method for studying molecular dynamics at atomic resolution. Recent methods development in biomolecular NMR spectroscopy has enabled detailed investigations of molecular dynamics that are critical for biological function, with prominent examples addressing allostery, enzyme cataly...

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

authors： Lundström P,Mulder FA,Akke M

更新日期：2005-11-22 00:00:00

abstract：:Adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity of purified secretory vesicle membranes from the adrenal medulla is inhibited by I-isoproterenol and I-epinephrine, as well as by nerve growth factor (NGF). The effect of these agents was found to be dose-dependent and, in the case of the cat...

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

authors： Nikodijevic O,Nikodijevic B,Zinder O,Yu MY,Guroff G,Pollard HB

更新日期：1976-03-01 00:00:00

abstract：:Genetic selections that use proteinaceous transdominant inhibitors encoded by DNA libraries to cause mutant phenocopies may facilitate genetic analysis in traditionally nongenetic organisms. We performed a selection for random short peptides and larger protein fragments (collectively termed "perturbagens") that inhibi...

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

authors： Caponigro G,Abedi MR,Hurlburt AP,Maxfield A,Judd W,Kamb A

更新日期：1998-06-23 00:00:00

abstract：:The 2-deoxy-D-glucose method was used to study asymmetries in cerebral metabolic activity in neonatal rats. Left-right asymmetries in 2-deoxy-D-glucose uptake were observed in hippocampus, diencephalon, cortex, and medulla-pons: 2-deoxy-D-glucose incorporation was greater in right hippocampus, right diencephalon, left...

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

authors： Ross DA,Glick SD,Meibach RC

更新日期：1981-03-01 00:00:00

abstract：:Chromatin remodeling complexes have been implicated in the disruption or reformation of nucleosomal arrays resulting in modulation of transcription, DNA replication, and DNA repair. Here we report the isolation of WCRF, a new chromatin-remodeling complex from HeLa cells. WCRF is composed of two subunits, WCRF135, the ...

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

authors： Bochar DA,Savard J,Wang W,Lafleur DW,Moore P,Côté J,Shiekhattar R

更新日期：2000-02-01 00:00:00

abstract：:People who are more avoidant of pathogens are more politically conservative, as are nations with greater parasite stress. In the current research, we test two prominent hypotheses that have been proposed as explanations for these relationships. The first, which is an intragroup account, holds that these relationships ...

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

authors： Tybur JM,Inbar Y,Aarøe L,Barclay P,Barlow FK,de Barra M,Becker DV,Borovoi L,Choi I,Choi JA,Consedine NS,Conway A,Conway JR,Conway P,Adoric VC,Demirci DE,Fernández AM,Ferreira DC,Ishii K,Jakšić I,Ji T,van Leeuwen

更新日期：2016-11-01 00:00:00

abstract：:This article discusses some of the similarities between work being done by economists and by physicists seeking to contribute to economics. We also mention some of the differences in the approaches taken and seek to justify these different approaches by developing the argument that by approaching the same problem from...

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

authors： Stanley HE,Amaral LA,Buldyrev SV,Gopikrishnan P,Plerou V,Salinger MA

更新日期：2002-02-19 00:00:00

abstract：:p70 S6 kinase (p70(S6k)) is a mitogen-activated protein kinase that plays a central role in the control of mRNA translation. It physiologically phosphorylates the S6 protein of the 40s ribosomal subunit in response to mitogenic stimuli and is a downstream component of the rapamycin-sensitive pathway, which includes th...

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

authors： Burnett PE,Blackshaw S,Lai MM,Qureshi IA,Burnett AF,Sabatini DM,Snyder SH

更新日期：1998-07-07 00:00:00

abstract：:The feeling of being observed or merely participating in an experiment can affect individuals' behavior. Referred to as the Hawthorne effect, this inconsistently observed phenomenon can both provide insight into individuals' behavior and confound the interpretation of experimental manipulations. Here, we pursue both t...

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

authors： Schwartz D,Fischhoff B,Krishnamurti T,Sowell F

更新日期：2013-09-17 00:00:00

abstract：:Fanconi anemia (FA) is caused by defects in cellular responses to DNA crosslinking damage and replication stress. Given the constant occurrence of endogenous DNA damage and replication fork stress, it is unclear why complete deletion of FA genes does not have a major impact on cell proliferation and germ-line FA patie...

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

authors： Wang R,Lenoir WF,Wang C,Su D,McLaughlin M,Hu Q,Shen X,Tian Y,Klages-Mundt N,Lynn E,Wood RD,Chen J,Hart T,Li L

更新日期：2020-12-29 00:00:00

abstract：:After exposure to low density lipoprotein (LDL) that had been minimally modified by oxidation (MM-LDL), human endothelial cells (EC) and smooth muscle cells (SMC) cultured separately or together produced 2- to 3-fold more monocyte chemotactic activity than did control cells or cells exposed to freshly isolated LDL. Th...

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

authors： Cushing SD,Berliner JA,Valente AJ,Territo MC,Navab M,Parhami F,Gerrity R,Schwartz CJ,Fogelman AM

更新日期：1990-07-01 00:00:00

abstract：:Endothelin, originally purified from porcine aortic endothelial cells, is widely distributed in tissues and is recognized as a product of epithelial cells, glial cells, and neurons in addition to endothelial cells. We found evidence by mRNA content and immunoreactivity that this peptide is synthesized in rat parathyro...

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

authors： Fujii Y,Moreira JE,Orlando C,Maggi M,Aurbach GD,Brandi ML,Sakaguchi K

更新日期：1991-05-15 00:00:00

abstract：:The Rev protein of HIV-1, which facilitates the nuclear export of HIV-1 pre-mRNAs, has been a target for antiviral therapy. Here we describe a new strategy for inhibiting Rev function and HIV-1 replication. In contrast to previous approaches, we use a wild-type rather than a mutant Rev protein and covalently link this...

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

authors： Qian XY,Chen ZY,Zhang J,Rabson AB,Krug RM

更新日期：1996-08-20 00:00:00

abstract：:We have used electron microscopy to examine freshly isolated Salmonella typhimurium and Escherichia coli basal flagellar fragments, purified without resort to extremes of pH or ionic strength. Such fragments contain the large bell-like basal structures visualized recently in freeze-substituted or fixed preparations. W...

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

authors： Khan IH,Reese TS,Khan S

更新日期：1992-07-01 00:00:00

abstract：:The acid-sensing ion channel-1 (ASIC1) contributes to synaptic plasticity and may influence the response to cerebral ischemia and acidosis. We found that cAMP-dependent protein kinase phosphorylated heterologously expressed ASIC1 and endogenous ASIC1 in brain slices. ASIC1 also showed significant phosphorylation under...

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

authors： Leonard AS,Yermolaieva O,Hruska-Hageman A,Askwith CC,Price MP,Wemmie JA,Welsh MJ

更新日期：2003-02-18 00:00:00

abstract：:A study has been made of Cauchy's problem for a class of abstract parabolic differential equations. Our study is based upon a transformation that maps solutions of second-order abstract Cauchy problems into solutions of first-order. This is a preliminary report on some of the results obtained. These results include (1...

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

authors： Donaldson JA

更新日期：1971-09-01 00:00:00

abstract：:Graphene oxide (GO), the main precursor of graphene-based materials made by solution processing, is known to be very stiff. Indeed, it has a Young's modulus comparable to steel, on the order of 300 GPa. Despite its very high stiffness, we show here that GO is superflexible. We quantitatively measure the GO bending rig...

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

authors： Poulin P,Jalili R,Neri W,Nallet F,Divoux T,Colin A,Aboutalebi SH,Wallace G,Zakri C

更新日期：2016-10-04 00:00:00

abstract：:Fibrinogen binding to receptors on stimulated platelets is a prerequisite for platelet aggregation. To gain further insight into the role of fibrinogen in platelet aggregation and to identify the platelet fibrinogen receptor, we developed a monoclonal anti-platelet antibody that inhibited platelet aggregation. The pur...

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

authors： Bennett JS,Hoxie JA,Leitman SF,Vilaire G,Cines DB

更新日期：1983-05-01 00:00:00

abstract：:Various biological processes exhibit characteristics that vary dramatically in response to different input conditions or changes in the history of the process itself. One of the examples studied here, the Ras-PKC-mitogen-activated protein kinase (MAPK) bistable pathway, follows two distinct dynamics (modes) depending ...

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

authors： Barbano PE,Spivak M,Feng J,Antoniotti M,Mishra B

更新日期：2005-05-03 00:00:00

abstract：:Avian reovirus S1133 penetrates and uncoats in suspension cultures of mouse L cells. The multiple species of viral transcripts are produced in the cytoplasm of the infected cell, but they fail to associate with polysomes, consistent with the absence of viral protein synthesis. The selective block in avian virus mRNA t...

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

authors： Benavente J,Shatkin AJ

更新日期：1988-06-01 00:00:00

abstract：:Signaling through the Toll receptor is required for dorsal/ventral polarity in Drosophila embryos, and also plays an evolutionarily conserved role in the immune response. Upon ligand binding, Toll appears to multimerize and activate the associated kinase, Pelle. However, the immediate downstream targets of Pelle have ...

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

authors： Shen B,Liu H,Skolnik EY,Manley JL

更新日期：2001-07-17 00:00:00