Impact melting of frozen oceans on the early Earth: implications for the origin of life.

abstract：:The binding of killer cell Ig-like Receptors (KIR) to their Class I MHC ligands was shown previously to be characterized by extremely rapid association and dissociation rate constants. During experiments to investigate the biochemistry of receptor-ligand binding in more detail, the kinetic parameters of the interactio...

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

authors： Valés-Gómez M,Erskine RA,Deacon MP,Strominger JL,Reyburn HT

更新日期：2001-02-13 00:00:00

abstract：:Recently, a 29-residue cyclic peptide was synthesized (TrPepz) that was reported to possess nearly the same catalytic activity and specificity as the pancreatic serine protease, trypsin, for hydrolysis of a small ester substrate, N-tosyl-L-arginine methyl ester (TAME), and small and large peptides [Atassi, M. Z. & Man...

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

authors： Wells JA,Fairbrother WJ,Otlewski J,Laskowski M Jr,Burnier J

更新日期：1994-05-10 00:00:00

abstract：:The actin cytoskeleton is a critical regulator of cytoplasmic architecture and mechanics, essential in a myriad of physiological processes. Here we demonstrate a liquid phase of actin filaments in the presence of the physiological cross-linker, filamin. Filamin condenses short actin filaments into spindle-shaped dropl...

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

authors： Weirich KL,Banerjee S,Dasbiswas K,Witten TA,Vaikuntanathan S,Gardel ML

更新日期：2017-02-28 00:00:00

abstract：:The human renin gene was isolated from a Charon 4A human genomic library and characterized. The gene spans about 11.7 kilobases and consists of 10 exons and 9 introns that map at points that could be variable surface loops of the enzyme. The complete coding regions, the 5'- and 3'-flanking regions, and the exon-intron...

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

authors： Miyazaki H,Fukamizu A,Hirose S,Hayashi T,Hori H,Ohkubo H,Nakanishi S,Murakami K

更新日期：1984-10-01 00:00:00

abstract：:Cognitive studies of memory processes demonstrate that memory for stimuli is a function of how they are encoded; stimuli processed semantically are better remembered than those processed in a perceptual or shallow fashion. This study investigates the neural correlates of this cognitive phenomenon. Twelve subjects perf...

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

authors： Kapur S,Craik FI,Tulving E,Wilson AA,Houle S,Brown GM

更新日期：1994-03-15 00:00:00

abstract：:Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Althoug...

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

authors： Gibbs HK,Ruesch AS,Achard F,Clayton MK,Holmgren P,Ramankutty N,Foley JA

更新日期：2010-09-21 00:00:00

abstract：:Inducible cAMP early repressor (ICER) is a transcriptional repressor, which, because of alternate promoter use, is generated from the 3' region of the cAMP response modulator (Crem) gene. Its expression and nuclear occurrence are elevated by high cAMP levels in naturally occurring regulatory T cells (nTregs). Using tw...

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

authors： Vaeth M,Gogishvili T,Bopp T,Klein M,Berberich-Siebelt F,Gattenloehner S,Avots A,Sparwasser T,Grebe N,Schmitt E,Hünig T,Serfling E,Bodor J

更新日期：2011-02-08 00:00:00

abstract：:The covalent linkage of supramolecular monomers provides a powerful strategy for constructing dynamic polymeric materials whose properties can be readily tuned either by the selection of monomers or the choice of functional linkers. In this strategy, the stabilities of the supramolecular monomers and the reactions use...

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

authors： Zhang M,Li S,Yan X,Zhou Z,Saha ML,Wang YC,Stang PJ

更新日期：2016-10-04 00:00:00

abstract：:PIK3CA mutations are reported to be present in approximately 25% of breast cancer (BC), particularly the estrogen receptor-positive (ER+) and HER2-overexpressing (HER2+) subtypes, making them one of the most common genetic aberrations in BC. In experimental models, these mutations have been shown to activate AKT and i...

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

authors： Loi S,Haibe-Kains B,Majjaj S,Lallemand F,Durbecq V,Larsimont D,Gonzalez-Angulo AM,Pusztai L,Symmans WF,Bardelli A,Ellis P,Tutt AN,Gillett CE,Hennessy BT,Mills GB,Phillips WA,Piccart MJ,Speed TP,McArthur GA,Sotiriou

更新日期：2010-06-01 00:00:00

abstract：:Gastrulation is a fundamental process in early development that results in the formation of three primary germ layers. During avian gastrulation, presumptive mesodermal cells in the dorsal epiblast ingress through a furrow called the primitive streak (PS), and subsequently move away from the PS and form adult tissues....

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

authors： Zamir EA,Czirók A,Cui C,Little CD,Rongish BJ

更新日期：2006-12-26 00:00:00

abstract：:Somatic fungal hyphae are generally assumed to elongate at steady linear rates when grown under constant environmental conditions with ample nutrients. However, patterns of pulsed hyphal elongation were detected during apparent steady growth of hyphal tips in fungi from several major taxonomic groups (Oomycetes, Pythi...

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

authors： López-Franco R,Bartnicki-Garcia S,Bracker CE

更新日期：1994-12-06 00:00:00

abstract：:Cellular senescence is defined by the limited proliferative capacity of normal cultured cells. Immortal cells overcome this regulation and proliferate indefinitively. One step in the immortalization process may be reactivation of telomerase activity, a ribonucleoprotein complex, which, by de novo synthesized telomeric...

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

authors： Härle-Bachor C,Boukamp P

更新日期：1996-06-25 00:00:00

abstract：:In light of the rapid recent retreat of Arctic sea ice, a number of studies have discussed the possibility of a critical threshold (or "tipping point") beyond which the ice-albedo feedback causes the ice cover to melt away in an irreversible process. The focus has typically been centered on the annual minimum (Septemb...

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

authors： Eisenman I,Wettlaufer JS

更新日期：2009-01-06 00:00:00

abstract：:The amino-terminal amino acid sequence and several internal peptide sequences of angiotensin I-converting enzyme (ACE; peptidyl-dipeptidase A, kininase II; EC 3.4.15.1) purified from human kidney were used to design oligonucleotide probes. The nucleotide sequence of ACE mRNA was determined by molecular cloning of the ...

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

authors： Soubrier F,Alhenc-Gelas F,Hubert C,Allegrini J,John M,Tregear G,Corvol P

更新日期：1988-12-01 00:00:00

abstract：:Non-human primates (NHP) provide crucial research models. Their strong similarities to humans make them particularly valuable for understanding complex behavioral traits and brain structure and function. We report here the genetic mapping of an NHP nervous system biologic trait, the cerebrospinal fluid (CSF) concentra...

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

authors： Freimer NB,Service SK,Ophoff RA,Jasinska AJ,McKee K,Villeneuve A,Belisle A,Bailey JN,Breidenthal SE,Jorgensen MJ,Mann JJ,Cantor RM,Dewar K,Fairbanks LA

更新日期：2007-10-02 00:00:00

abstract：:The four-helical bundle soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) complex that mediates intracellular membrane fusion events contains a highly conserved ionic layer at the center of an otherwise hydrophobic core. This layer has an undetermined function; it consists of ...

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

authors： Scales SJ,Yoo BY,Scheller RH

更新日期：2001-12-04 00:00:00

abstract：:For almost a century the plant hormone auxin has been central to theories on apical dominance, whereby the growing shoot tip suppresses the growth of the axillary buds below. According to the classic model, the auxin indole-3-acetic acid is produced in the shoot tip and transported down the stem, where it inhibits bud...

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

authors： Mason MG,Ross JJ,Babst BA,Wienclaw BN,Beveridge CA

更新日期：2014-04-22 00:00:00

abstract：:Amyotrophic lateral sclerosis is a neurodegenerative syndrome associated with 114 mutations in the gene encoding the cytosolic homodimeric enzyme Cu/Zn superoxide dismutase (SOD). In this article, we report that amyotrophic lateral sclerosis-associated SOD mutations with distinctly different disease progression can be...

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

authors： Lindberg MJ,Byström R,Boknäs N,Andersen PM,Oliveberg M

更新日期：2005-07-12 00:00:00

abstract：:HIV infection leads to a state of chronic immune activation and progressive deterioration in immune function, manifested most recognizably by the progressive depletion of CD4+ T cells. A substantial percentage of natural killer (NK) cells from patients with HIV infection are activated and express the natural cytotoxic...

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

authors： Vieillard V,Strominger JL,Debré P

更新日期：2005-08-02 00:00:00

abstract：:The mitochondrial genome of the S-type male-sterile cytoplasm of maize contains two linear episomes, S1 (6397 base pairs) and S2 (5453 base pairs). The S2 episome contains two large unidentified open reading frames, URF1 (3512 base pairs) and URF2 (1017 base pairs). We have demonstrated that a polypeptide with an appa...

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

authors： Zabala G,O'brien-Vedder C,Walbot V

更新日期：1987-11-01 00:00:00

abstract：:Operant conditioning techniques were used to assess how gender and song familiarity affect song discrimination in adult zebra finches (Taeniopygia guttata). Twenty-five males and females, divided into five cohorts, were trained to discriminate between conspecific songs at different times of year. Males discriminating ...

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

authors： Cynx J,Nottebohm F

更新日期：1992-02-15 00:00:00

abstract：:The reversible association of alpha and beta gamma subunits of GTP-binding proteins is important for signal transmission from a variety of cell-surface receptors to intracellular effectors. Previous work showed that 1,6-bis(maleimido)hexane, which crosslinks cysteine residues, crosslinks alpha o and alpha i-1 to beta ...

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

authors： Thomas TC,Schmidt CJ,Neer EJ

更新日期：1993-11-01 00:00:00

abstract：:I have determined the nucleotide sequence of the ampicillin resistance gene of pBR322, an Escherichia coli plasmid that encodes a penicillin beta-lactamase. This gene codes for a protein of 286 amino acid residues. The first 23 amino acids presumably form a signal for secretion, because they do not appear in the matur...

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

authors： Sutcliffe JG

更新日期：1978-08-01 00:00:00

abstract：:A complete experimental format is given for the reconstitution of human hemoglobin from the separated heme-free alpha- and beta-globin chains (alpha degrees, beta degrees) and hemin, by two alternative routes. Based on their oxygen binding properties, the reaction of the ferri-forms with reducing agent, and the respon...

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

authors： Yip YK,Waks M,Beychok S

更新日期：1977-01-01 00:00:00

abstract：:The results of previous preclinical and clinical studies have identified angiogenin (ANG) as a potentially important target for anticancer therapy. Here we report the design and implementation of a high-throughput screening assay to identify small molecules that bind to the ribonucleolytic active site of ANG, which is...

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

authors： Kao RY,Jenkins JL,Olson KA,Key ME,Fett JW,Shapiro R

更新日期：2002-07-23 00:00:00

abstract：:A neuroethological approach to human and nonhuman primate behavior and cognition predicts biological specializations for social life. Evidence reviewed here indicates that ancestral mechanisms are often duplicated, repurposed, and differentially regulated to support social behavior. Focusing on recent research from no...

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

authors： Chang SW,Brent LJ,Adams GK,Klein JT,Pearson JM,Watson KK,Platt ML

更新日期：2013-06-18 00:00:00

abstract：:A two-dimensional model of the expansion of a crack in an elastic medium is considered in which friction depends on the slip rate and the modulus of cohesion depends on the speed of expansion of the crack. Elastic waves are neglected (quasi-static model). Under some conditions, the expansion of the crack is realized b...

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

authors： Barenblatt GI,Keilis-Borok VI,Vishik MM

更新日期：1981-09-01 00:00:00

abstract：:The three-dimensional organization of HLA antigens has been investigated by spectroscopic and immunochemical techniques. Measurement of the circular dichroism shows that in papain-solubilized HLA the heavy chain as well as the previously studied light chain (beta 2-microglobulin) consists predominantly of beta-pleated...

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

authors： Lancet D,Parham P,Strominger JL

更新日期：1979-08-01 00:00:00

abstract：:The p53 tumor suppressor protein and the MDM2 oncoprotein form a feedback-control loop that up-regulates cellular MDM2 production, blocks p53 activity, and promotes p53 decay. tsg101 was discovered as a gene whose deficiency results in neoplastic transformation of NIH 3T3 cells and the ability to generate metastatic t...

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

authors： Li L,Liao J,Ruland J,Mak TW,Cohen SN

更新日期：2001-02-13 00:00:00

abstract：:Positive lower bounds for pseudo-differential operators with nonnegative symbols are derived; the bounds in particular yield subelliptic estimates for operators arising as sums of squares of vector fields. ...

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

authors： Fefferman C,Phong DH

更新日期：1979-12-01 00:00:00