An uncorrelated relaxed-clock analysis suggests an earlier origin for flowering plants.

abstract：:Collectivistic cultures have been characterized as having harmonious, cooperative ingroup relationships. However, we find evidence that people in collectivistic cultures are more vigilant toward ingroup members, mindful of their possible unethical intentions. Study 1 found that Chinese participants were more vigilant ...

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

authors： Liu SS,Morris MW,Talhelm T,Yang Q

更新日期：2019-07-16 00:00:00

abstract：:We used a modified subtractive suppression hybridization to identify cellular genes that show altered expression in Burkitt lymphomas (BLs) in the presence of Epstein-Barr virus (EBV). Comparison of the gene expression patterns of an EBV-negative clone of the originally EBV-positive BL line Akata, with its Neo(R)-EBV ...

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

authors： Kiss C,Nishikawa J,Takada K,Trivedi P,Klein G,Szekely L

更新日期：2003-04-15 00:00:00

abstract：:Previously it was shown that yeast ADA2 protein is necessary for the full activity of some activation domains, such as VP16 and GCN4, in vivo and in vitro. These results suggest that ADA2 protein functions as a transcriptional coactivator or adaptor that bridges the interaction between certain acidic activation domain...

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

authors： Silverman N,Agapite J,Guarente L

更新日期：1994-11-22 00:00:00

abstract：:The solution conformations of 2-substituted derivatives of 1-(beta-D-ribofuranosyl)benzimidazole have been determined by circular dichroism spectroscopy in aqueous solutions. It is shown that analogs with methyl, amino, or methylamino substituents at position 2 of the benzimidazole ring (position 8 of the purine ring)...

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

authors： Miles DW,Townsend LB,Miles DL,Eyring H

更新日期：1979-02-01 00:00:00

abstract：:Colorectal cancer is the second leading cause of cancer-related deaths in the United States. Understanding the distinct genetic and epigenetic changes contributing to the establishment and growth of metastatic lesions is crucial for the development of novel therapeutic strategies. In a search for key regulators of col...

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

authors： Rychahou PG,Kang J,Gulhati P,Doan HQ,Chen LA,Xiao SY,Chung DH,Evers BM

更新日期：2008-12-23 00:00:00

abstract：:The rate of change of climate codetermines the global warming impacts on natural and socioeconomic systems and their capabilities to adapt. Establishing past rates of climate change from temperature proxy data remains difficult given their limited spatiotemporal resolution. In contrast, past greenhouse gas radiative f...

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

authors： Joos F,Spahni R

更新日期：2008-02-05 00:00:00

abstract：:The structure of cellulose microfibrils in wood is not known in detail, despite the abundance of cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the microfibrils of spruce wood cellulose was investigated using a range of spectroscopic methods coupled to small-angle ...

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

authors： Fernandes AN,Thomas LH,Altaner CM,Callow P,Forsyth VT,Apperley DC,Kennedy CJ,Jarvis MC

更新日期：2011-11-22 00:00:00

abstract：:3.L2 T cell receptor transgenic T cells are activated by the 64-76 peptide of the mouse hemoglobin d beta chain [Hb(64-76)], and their response is antagonized by the position 72 alanine substitution of this peptide (A72). To test the effect of this altered peptide ligand (APL) on 3.L2 T cell function in vivo, a transg...

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

authors： Basu D,Williams CB,Allen PM

更新日期：1998-11-24 00:00:00

abstract：:Aneuploidy is ubiquitous in cancer, and its phenotypes are inevitably dominant and abnormal. In view of these facts we recently proposed that aneuploidy is sufficient for carcinogenesis generating cancer-specific aneusomies via a chain reaction of autocatalytic aneuploidizations. According to this hypothesis a carcino...

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

authors： Fabarius A,Willer A,Yerganian G,Hehlmann R,Duesberg P

更新日期：2002-05-14 00:00:00

abstract：:Erythropoietin, the hormone that is the primary regulator of erythrocyte production, has been purified from anemic-sheep plasma, with a purification factor of more than 1 million. Gel electrophoresis shows that the major contaminant is desialated erythropoietin. ...

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

authors： Goldwasser E,Kung CK

更新日期：1971-04-01 00:00:00

abstract：:Current issues pertaining to theoretical simulations of materials, with a focus on systems of nanometer-scale dimensions, are discussed. The use of atomistic simulations as high-resolution numerical experiments, enabling and guiding formulation and testing of analytic theoretical descriptions, is demonstrated through ...

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

authors： Landman U

更新日期：2005-05-10 00:00:00

abstract：:Alzheimer's disease (AD) is characterized by a progressive dysfunction of central neurons. Recent experimental evidence indicates that in the cortex, in addition to the silencing of a fraction of neurons, other neurons are hyperactive in amyloid-β (Aβ) plaque-enriched regions. However, it has remained unknown what com...

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

authors： Busche MA,Chen X,Henning HA,Reichwald J,Staufenbiel M,Sakmann B,Konnerth A

更新日期：2012-05-29 00:00:00

abstract：:Questions that still surround the origin and early dispersals of maize (Zea mays L.) result in large part from the absence of information on its early history from the Balsas River Valley of tropical southwestern Mexico, where its wild ancestor is native. We report starch grain and phytolith data from the Xihuatoxtla ...

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

authors： Piperno DR,Ranere AJ,Holst I,Iriarte J,Dickau R

更新日期：2009-03-31 00:00:00

abstract：:Dietary restriction has been shown to have several health benefits including increased insulin sensitivity, stress resistance, reduced morbidity, and increased life span. The mechanism remains unknown, but the need for a long-term reduction in caloric intake to achieve these benefits has been assumed. We report that w...

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

authors： Anson RM,Guo Z,de Cabo R,Iyun T,Rios M,Hagepanos A,Ingram DK,Lane MA,Mattson MP

更新日期：2003-05-13 00:00:00

abstract：:Breast cancer comprises a heterogeneous set of diseases distinguishable from one another by pathologic presentation and molecular signatures. However, each breast cancer subtype is also heterogeneous. Some of the heterogeneity may be attributable to genetic instability, but recent data emphasize that developmental pla...

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

authors： Mizuno H,Spike BT,Wahl GM,Levine AJ

更新日期：2010-12-28 00:00:00

abstract：:The appearance of jaws was a turning point in vertebrate evolution because it allowed primitive vertebrates to capture and process large, motile prey. The vertebrate jaw consists of separate dorsal and ventral skeletal elements connected by a joint. How this structure evolved from the unjointed gill bar of a jawless a...

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

authors： Cerny R,Cattell M,Sauka-Spengler T,Bronner-Fraser M,Yu F,Medeiros DM

更新日期：2010-10-05 00:00:00

abstract：:The design, realization, and test performances of an electronic junction based on single-electron phenomena that works in the air at room temperature are hereby reported. The element consists of an electrochemically etched sharp tungsten stylus over whose tip a nanometer-size crystal was synthesized. Langmuir-Blodgett...

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

authors： Facci P,Erokhin V,Carrara S,Nicolini C

更新日期：1996-10-01 00:00:00

abstract：:Understanding how electric fields and their fluctuations in the active site of enzymes affect efficient catalysis represents a critical objective of biochemical research. We have directly measured the dynamics of the electric field in the active site of a highly proficient enzyme, Δ(5)-3-ketosteroid isomerase (KSI), i...

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

authors： Jha SK,Ji M,Gaffney KJ,Boxer SG

更新日期：2011-10-04 00:00:00

abstract：:Whereas NF-kappaB has potent antiapoptotic function in most cell types, it was reported that in pancreatic beta cells it serves a proapoptotic function and may contribute to the pathogenesis of autoimmune type 1 diabetes. To investigate the role of beta cell NF-kappaB in autoimmune diabetes, we produced transgenic mic...

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

authors： Kim S,Millet I,Kim HS,Kim JY,Han MS,Lee MK,Kim KW,Sherwin RS,Karin M,Lee MS

更新日期：2007-02-06 00:00:00

abstract：:We report here on the isolation and characterization of a serotonin (5HT) transporter from Drosophila melanogaster. A 3.1-kb complementary DNA clone (dSERT) was found to encode a protein of 622 amino acid residues with a predicted molecular mass of approximately 69 kDa and a putative transmembrane topology characteris...

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

authors： Demchyshyn LL,Pristupa ZB,Sugamori KS,Barker EL,Blakely RD,Wolfgang WJ,Forte MA,Niznik HB

更新日期：1994-05-24 00:00:00

abstract：:Herpesvirus saimiri (HVS) is the prototype member of a distinctive subset of lymphotropic herpesviruses (the gamma 2 subgroup) with A+T-rich coding sequences. In this paper, we show that cells productively infected with HVS contain high concentrations of a virus-specified thymidylate synthase (5,10-methylenetetrahydro...

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

authors： Honess RW,Bodemer W,Cameron KR,Niller HH,Fleckenstein B,Randall RE

更新日期：1986-06-01 00:00:00

abstract：:We introduce a polynomial C(mu)[Z; q, t], depending on a set of variables Z = z(1), z(2),..., a partition mu, and two extra parameters q, t. The definition of C(mu) involves a pair of statistics (maj(sigma, mu), inv(sigma, mu)) on words sigma of positive integers, and the coefficients of the z(i) are manifestly in N[q...

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

authors： Haglund J

更新日期：2004-11-16 00:00:00

abstract：:Iron is an essential nutrient for the survival of most organisms and has played a central role in the virulence of many infectious disease pathogens. Mycobacterial IdeR is an iron-dependent repressor that shows 80% identity in the functional domains with its corynebacterial homologue, DtxR (diphtheria toxin repressor)...

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

authors： Manabe YC,Saviola BJ,Sun L,Murphy JR,Bishai WR

更新日期：1999-10-26 00:00:00

abstract：:The nicotinic acetylcholine (ACh) receptor (nAChR) plays a crucial role in excitatory neurotransmission and is an important target for drugs and insecticides. Diverse nAChR subtypes with various subunit combinations confer differential selectivity for nicotinic drugs. We investigated the subtype selectivity of nAChR a...

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

authors： Tomizawa M,Maltby D,Talley TT,Durkin KA,Medzihradszky KF,Burlingame AL,Taylor P,Casida JE

更新日期：2008-02-05 00:00:00

abstract：:Recombination between unirradiated chromosomes was induced by UV or x-ray irradiation of haploids followed by a mating with heteroallelic diploids of Saccharomyces cerevisiae. The selected event of intragenic recombination did not involve the participation of the irradiated chromosome and apparently was not caused by ...

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

authors： Fabre F,Roman H

更新日期：1977-04-01 00:00:00

abstract：:Exposure of 3T3/A31 cells to serum-free medium, one type of apoptotic stimulus, causes a rapid increase in the sphingosine (Sph) level, which initiates a series of processes: (i) activation of caspase 3 through an enhanced "cascade" of caspases, (ii) release of the C-terminal-half kinase domain of PKCdelta (PKCdelta K...

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

authors： Suzuki E,Handa K,Toledo MS,Hakomori S

更新日期：2004-10-12 00:00:00

abstract：:Stearoyl-acyl-carrier-protein-desaturase-mediated conversion of stearic acid (18:0) to oleic acid (18:1) is a key step, which regulates levels of unsaturated fatty acids in cells. We previously showed that stearoyl-acyl-carrier-protein-desaturase mutants ssi2/fab2 carrying a loss-of-function mutation in the plastidial...

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

authors： Kachroo A,Venugopal SC,Lapchyk L,Falcone D,Hildebrand D,Kachroo P

更新日期：2004-04-06 00:00:00

abstract：:Understanding the molecular mechanisms of osmolyte protection in protein stability has proved to be challenging. In particular, little is known about the role of osmolytes in the structure of the unfolding transition state of a protein, the main determinant of its dynamics. We have developed an experimental protocol t...

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

authors： Dougan L,Genchev GZ,Lu H,Fernandez JM

更新日期：2011-06-14 00:00:00

abstract：:The increasing frequency of antibiotic resistance in hospital-acquired infections is a major public health concern that has both biological and economic causes. Here we develop conceptual mathematical models that couple the economic incentives and population biology of hospital infection control (HIC). We show that th...

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

authors： Smith DL,Levin SA,Laxminarayan R

更新日期：2005-02-22 00:00:00

abstract：:MscS is a mechanosensitive channel that is ubiquitous among bacteria. Recent progress in the genome projects has revealed that homologs of MscS are also present in eukaryotes, but whether they operate as ion channels is unknown. In this study we cloned MSC1, a homolog of MscS in Chlamydomonas, and examined its functio...

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

authors： Nakayama Y,Fujiu K,Sokabe M,Yoshimura K

更新日期：2007-04-03 00:00:00