Costs, needs, and integration efforts shape helping behavior toward refugees.

abstract：:The rat W3/25 antigen was the first marker antigen of helper T lymphocytes to be identified. Subsequently, the human OKT4 antigen (now called CD4) was described, and cell distribution and functional data suggested that W3/25 and OKT4 antigens were homologous. This is now confirmed by the matching of peptide sequences ...

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

authors： Clark SJ,Jefferies WA,Barclay AN,Gagnon J,Williams AF

更新日期：1987-03-01 00:00:00

abstract：:NADH:quinone oxidoreductase (complex I) plays a pivotal role in cellular energy production. It employs a series of redox cofactors to couple electron transfer to the generation of a proton-motive force across the inner mitochondrial or bacterial cytoplasmic membrane. Complex I contains a noncovalently bound flavin mon...

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

authors： Yakovlev G,Reda T,Hirst J

更新日期：2007-07-31 00:00:00

abstract：:This work describes the rational design, synthesis, and study of a ligand that selectively complexes CUG repeats in RNA (and CTG repeats in DNA) with high nanomolar affinity. This sequence is considered a causative agent of myotonic dystrophy type 1 (DM1) because of its ability to sequester muscleblind-like (MBNL) pro...

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

authors： Arambula JF,Ramisetty SR,Baranger AM,Zimmerman SC

更新日期：2009-09-22 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：:Water-biomolecule interactions have been extensively studied in dilute solutions, crystals, and rehydrated powders, but none of these model systems may capture the behavior of water in the highly organized intracellular milieu. Because of the experimental difficulty of selectively probing the structure and dynamics of...

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

authors： Persson E,Halle B

更新日期：2008-04-29 00:00:00

abstract：:Creatine kinase from rabbit muscle has been specifically labeled with a derivative of a nitroxide free radical on the two essential sulfhydryl groups, one per active site. The conformation in the environment of the enzyme-bound free radical and the change in conformation induced upon binding of the substrate, metal ad...

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

authors： Taylor JS,Leigh JS Jr,Cohn M

更新日期：1969-09-01 00:00:00

abstract：:Gyrate atrophy (GA), a recessive eye disease involving progressive loss of vision due to chorioretinal degeneration, is associated with a deficiency of the mitochondrial enzyme ornithine aminotransferase (OATase; ornithine-oxo-acid aminotransferase; L-ornithine:2-oxo-acid aminotransferase, EC 2.6.1.13) with consequent...

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

authors： Ramesh V,McClatchey AI,Ramesh N,Benoit LA,Berson EL,Shih VE,Gusella JF

更新日期：1988-06-01 00:00:00

abstract：:That the yolk proteins (YPs), or vitellins, stored in the oocytes of insects are a nutritional store for subsequent embryogenesis has long been assumed. Exhaustive data base searching programs revealed highly significant sequence similarity between the three YPs of Drosophila melanogaster and part of the triacylglycer...

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

authors： Bownes M,Shirras A,Blair M,Collins J,Coulson A

更新日期：1988-03-01 00:00:00

abstract：:Immediately after adsorption, phages T4 and T5 induce a partial depolarization of the host cytoplasmic membrane. Infected bacteria respond to this phage-induced effect by a repolarization that leads to a new steady state of reduced membrane potential. The rate and extent of repolarization are adjusted to the intensity...

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

authors： Labedan B,Letellier L

更新日期：1981-01-01 00:00:00

abstract：:Previous studies have identified an ATP-dependent DNA helicase activity intrinsic to the human minichromosome maintenance (MCM) complex, composed of MCM subunits 4, 6, and 7 [Ishimi, Y. (1997) J. Biol. Chem. 272, 24508-24513]. In contrast to the presence of multiple MCM genes (at least six) in eukaryotes, the archaeon...

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

authors： Kelman Z,Lee JK,Hurwitz J

更新日期：1999-12-21 00:00:00

abstract：:Although adaptor ADAP (FYB) and its binding to SLP-76 has been implicated in TcR-induced "inside-out" signaling for LFA-1 activation in T cells, little is known regarding its role in LFA-1-mediated "outside-in" signaling. In this study, we demonstrate that ADAP and SLP-76-ADAP binding are coupled to LFA-1 costimulatio...

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

authors： Wang H,Wei B,Bismuth G,Rudd CE

更新日期：2009-07-28 00:00:00

abstract：:The development of protein subunit vaccines to combat some of the world's deadliest pathogens such as a malaria parasite, Plasmodium falciparum, is stalled, due in part to the inability to induce and sustain high-titer antibody responses. Here, we show the induction of persistent, high-titer antibody responses to reco...

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

authors： Wu Y,Przysiecki C,Flanagan E,Bello-Irizarry SN,Ionescu R,Muratova O,Dobrescu G,Lambert L,Keister D,Rippeon Y,Long CA,Shi L,Caulfield M,Shaw A,Saul A,Shiver J,Miller LH

更新日期：2006-11-28 00:00:00

abstract：:High levels of inbreeding cause populations to become composed of homozygous, inbred lines. High levels of homozygosity limit the effectiveness of recombination, and therefore, retard the rate of decay of linkage (gametic phase) disequilibrium (LD) among mutations. Inbreeding and recombination interact to shape the ex...

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

authors： Morrell PL,Toleno DM,Lundy KE,Clegg MT

更新日期：2005-02-15 00:00:00

abstract：:Methods to accurately predict potential drug target mutations in response to early-stage leads could drive the design of more resilient first generation drug candidates. In this study, a structure-based protein design algorithm (K* in the OSPREY suite) was used to prospectively identify single-nucleotide polymorphisms...

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

authors： Reeve SM,Gainza P,Frey KM,Georgiev I,Donald BR,Anderson AC

更新日期：2015-01-20 00:00:00

abstract：:With 13C NMR, phosphoglucose isomerase (PGI; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9) is shown to produce mannose 6-phosphate (M6P) slowly from a much more rapidly catalyzed equilibrium between glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P). The identity of M6P and its formation from G6P plus F6P a...

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

authors： Seeholzer SH

更新日期：1993-02-15 00:00:00

abstract：:Adults and older children are more likely to punish a wrongdoer for a moral transgression when the victim belongs to their group. Building on these results, in violation-of-expectation experiments (n = 198), we examined whether 2.5-year-old toddlers (Exps. 1 and 2) and 1-year-old infants (Exps. 3 and 4) would selectiv...

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

authors： Ting F,He Z,Baillargeon R

更新日期：2019-03-26 00:00:00

abstract：:We present a method for designing a funnel-shaped free-energy surface that reproducibly assembles secondary structure elements of proteins into their native conformations from a random extended configuration. Assuming a priori knowledge of secondary structure, our method can design a funnel-shaped surface for folding ...

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

authors： Fain B,Levitt M

更新日期：2003-09-16 00:00:00

abstract：:Despite enormous body plan variation, genes regulating embryonic development are highly conserved. Here, we probe the mechanisms that predispose ancient regulatory genes to reutilization and diversification rather than evolutionary loss. The Hox gene fushi tarazu (ftz) arose as a homeotic gene but functions as a pair-...

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

authors： Heffer A,Xiang J,Pick L

更新日期：2013-02-05 00:00:00

abstract：:The microvillus core-filament bundle from intestinal epithelial cells is a highly ordered structure containing actin and four major associated proteins. Two of these, villin and calmodulin, bind calcium ions (Kd approximately 10(-6) M) in the physiologically important range. Because ethylene glycol bis(beta-aminoethyl...

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

authors： Glenney JR Jr,Bretscher A,Weber K

更新日期：1980-11-01 00:00:00

abstract：:Most genetic regulatory mechanisms involve protein-DNA interactions. In these processes, the classical Watson-Crick DNA structure sometimes is distorted severely, which in turn enables the precise recognition of the specific sites by the protein. Despite its key importance, very little is known about such deformation ...

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

authors： Leger JF,Robert J,Bourdieu L,Chatenay D,Marko JF

更新日期：1998-10-13 00:00:00

abstract：:FKBP12-rapamycin associated protein (FRAP, also known as mTOR or RAFT) is the founding member of the phosphatidylinositol kinase-related kinase family and functions as a sensor of physiological signals that regulate cell growth. Signals integrated by FRAP include nutrients, cAMP levels, and osmotic stress, and cellula...

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

authors： Desai BN,Myers BR,Schreiber SL

更新日期：2002-04-02 00:00:00

abstract：:The reliability of (13)C NMR chemical shift correlations in the application of the "tool of increasing electron demand" to stable long-lived carbocationic systems is demonstrated by a comprehensive analysis of 22 stable aryl-substituted carbocationic systems. The observation of slopes of less than unity in such chemic...

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

authors： Olah GA,Berrier AL,Prakash GK

更新日期：1981-04-01 00:00:00

abstract：:Resting- or baseline-state low-frequency (0.01-0.2 Hz) brain activity is observed in fMRI, EEG, and local field potential recordings. These fluctuations were found to be correlated across brain regions and are thought to reflect neuronal activity fluctuations between functionally connected areas of the brain. However,...

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

authors： Krishnan GP,González OC,Bazhenov M

更新日期：2018-06-26 00:00:00

abstract：:Bones of the flightless sea duck (Chendytes lawi) from 14 archaeological sites along the California coast indicate that humans hunted the species for at least 8,000 years before it was driven to extinction. Direct (14)C dates on Chendytes bones show that the duck was exploited on the southern California islands as ear...

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

authors： Jones TL,Porcasi JF,Erlandson JM,Dallas H Jr,Wake TA,Schwaderer R

更新日期：2008-03-18 00:00:00

abstract：:The induction of antigen-specific tolerance is critical for the prevention of autoimmunity and maintenance of immune tolerance. In addition to their classical role as sentinels of the immune response-inducing T cell reactivity, dendritic cells (DCs) play an important role in maintaining peripheral tolerance through th...

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

authors： Chorny A,Gonzalez-Rey E,Fernandez-Martin A,Pozo D,Ganea D,Delgado M

更新日期：2005-09-20 00:00:00

abstract：:Prototrophic hybrids formed from an adenine-requiring Chinese hamster cell and human fibroblasts uniformly display new esterase activity that differs from that of either parental cell in electrophoretic mobility and substrate specificity. The hybrids that grew in the selective medium and possessed the new esterase act...

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

authors： Kao FT,Puck TT

更新日期：1972-11-01 00:00:00

abstract：:RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. It is not known whether host cells also use siRNAs as an antibacterial defense mechanism in eukaryotes. Here, we report the discovery of an endogeno...

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

authors： Katiyar-Agarwal S,Morgan R,Dahlbeck D,Borsani O,Villegas A Jr,Zhu JK,Staskawicz BJ,Jin H

更新日期：2006-11-21 00:00:00

abstract：:Animal development is remarkably robust; cell fates are specified with spatial and temporal precision despite physiological and environmental contingencies. Favorable conditions cause Caenorhabditis elegans to develop rapidly through four larval stages (L1-L4) to the reproductive adult. In unfavorable conditions, L2 l...

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

authors： Hammell CM,Karp X,Ambros V

更新日期：2009-11-03 00:00:00

abstract：:Microcalcifications geographically target the location of abnormalities within the breast and are of critical importance in breast cancer diagnosis. However, despite stereotactic guidance, core needle biopsy fails to retrieve microcalcifications in up to 15% of patients. Here, we introduce an approach based on diffuse...

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

authors： Soares JS,Barman I,Dingari NC,Volynskaya Z,Liu W,Klein N,Plecha D,Dasari RR,Fitzmaurice M

更新日期：2013-01-08 00:00:00

abstract：:Natural abundance 13C spin-lattice (T1) relaxation time measurements are reported for unilamellar vesicles of 1,2-dipalmitoylphosphatidylcholine (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), in the liquid crystalline phase, at magnetic field strengths of 1.40, 1.87, 2.35, 4.23, 7.05, 8.45, and 11.7 tesla (resonance f...

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

authors： Brown MF,Ribeiro AA,Williams GD

更新日期：1983-07-01 00:00:00