The sizes of the CDR3 hypervariable regions of the murine T-cell receptor beta chains vary as a function of the recombined germ-line segments.

abstract：:Measures of complexity derived from ergodic theory of dynamical systems were developed and applied to an exemplary data set describing locomotor movements of rats in a bounded space. A symbolic dynamical system was obtained by partitioning the event space into equally probable partition elements, using a k-dimensional...

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

authors： Paulus MP,Geyer MA,Gold LH,Mandell AJ

更新日期：1990-01-01 00:00:00

abstract：:Hydra interstitial stem cells continuously give rise to daughter stem cells as well as precursors for nerve and nematocyte differentiation. Growth of the stem cell population is controlled by the self-renewal probability (Ps): Ps is the fraction of stem cell daughters that remain stem cells in each generation. We have...

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

authors： David CN,MacWilliams H

更新日期：1978-02-01 00:00:00

abstract：:Immune cells take residence in metabolic tissues, providing a framework for direct regulation of nutrient metabolism. Despite conservation of this anatomic relationship through evolution, the signals and mechanisms by which the immune system regulates nutrient homeostasis and insulin action remain poorly understood. H...

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

authors： Ricardo-Gonzalez RR,Red Eagle A,Odegaard JI,Jouihan H,Morel CR,Heredia JE,Mukundan L,Wu D,Locksley RM,Chawla A

更新日期：2010-12-28 00:00:00

abstract：:Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged delta(18)O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprece...

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

authors： Thompson LG,Mosley-Thompson E,Brecher H,Davis M,León B,Les D,Lin PN,Mashiotta T,Mountain K

更新日期：2006-07-11 00:00:00

abstract：:In addition to their roles in desensitization and signaling of seven-membrane-spanning receptors, beta-arrestins have been more recently implicated in regulating non-seven-membrane-spanning receptor pathways. By using a yeast two-hybrid screen, we identified the inhibitor of NF-kappaB, IkappaBalpha, as a binding partn...

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

authors： Witherow DS,Garrison TR,Miller WE,Lefkowitz RJ

更新日期：2004-06-08 00:00:00

abstract：:The mechanistic basis for chloroquine resistance (CQR) in Plasmodium falciparum recently has been linked to the polymorphic gene pfcrt. Alleles associated with CQR in natural parasite isolates harbor threonine (T), as opposed to lysine (K) at amino acid 76. P. falciparum CQR strains of African and Southeast Asian orig...

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

authors： Mehlotra RK,Fujioka H,Roepe PD,Janneh O,Ursos LM,Jacobs-Lorena V,McNamara DT,Bockarie MJ,Kazura JW,Kyle DE,Fidock DA,Zimmerman PA

更新日期：2001-10-23 00:00:00

abstract：:Host factor protein Cyclophilin A (CypA) regulates HIV-1 viral infectivity through direct interactions with the viral capsid, by an unknown mechanism. CypA can either promote or inhibit viral infection, depending on host cell type and HIV-1 capsid (CA) protein sequence. We have examined the role of conformational dyna...

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

authors： Lu M,Hou G,Zhang H,Suiter CL,Ahn J,Byeon IJ,Perilla JR,Langmead CJ,Hung I,Gor'kov PL,Gan Z,Brey W,Aiken C,Zhang P,Schulten K,Gronenborn AM,Polenova T

更新日期：2015-11-24 00:00:00

abstract：:Memory stretches over a lifetime. In controlled laboratory settings, the hippocampus and other medial temporal lobe brain structures have been shown to represent space and time on the scale of meters and seconds. It remains unclear whether the hippocampus also represents space and time over the longer scales necessary...

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

authors： Nielson DM,Smith TA,Sreekumar V,Dennis S,Sederberg PB

更新日期：2015-09-01 00:00:00

abstract：:Although it has been known for decades that the tight junctions of fluid-transporting epithelia are leaky to ions, it has not been possible to determine directly whether significant transjunctional water movement also occurs. An optical microscopic technique was developed for the direct visualization of the flow veloc...

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

authors： Kovbasnjuk O,Leader JP,Weinstein AM,Spring KR

更新日期：1998-05-26 00:00:00

abstract：:Nature is rife with networks that are functionally optimized to propagate inputs to perform specific tasks. Whether via genetic evolution or dynamic adaptation, many networks create functionality by locally tuning interactions between nodes. Here we explore this behavior in two contexts: strain propagation in mechanic...

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

authors： Rocks JW,Ronellenfitsch H,Liu AJ,Nagel SR,Katifori E

更新日期：2019-02-12 00:00:00

abstract：:Certain mutations at the glaB locus result in the failure to fully derepress glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] and to convert it to the active nonadenylylated form in response to nitrogen limitation. In these mutants the PII regulatory protein is altered such that it cannot be...

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

authors： Foor F,Reuveny Z,Magasanik B

更新日期：1980-05-01 00:00:00

abstract：:Adult workers in honeybee (Apis mellifera) colonies exhibit plasticity in hormonally regulated, age-based division of labor by altering their pattern of behavioral development in response to changes in colony conditions. One form of this plasticity is precocious development: levels of juvenile hormone increase prematu...

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

authors： Huang ZY,Robinson GE

更新日期：1992-12-15 00:00:00

abstract：:A direct method for the determination of N-linked glycosylation sites in highly glycosylated proteins is described. Carcinoembryonic antigen (CEA) and a nonspecific crossreacting antigen (NCA) were chemically deglycosylated, and peptide maps were prepared by reverse-phase HPLC. The peptides were sequenced on a gas-pha...

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

authors： Paxton RJ,Mooser G,Pande H,Lee TD,Shively JE

更新日期：1987-02-01 00:00:00

abstract：:This paper describes experiments in which cytosolic Ca2+ concentrations ([Ca2+]i) and catecholamine release were measured in two populations of chromaffin cells stimulated with a solution enriched in K+ (100 mM). Once depolarized, external Ca2+ or Ba2+ ions were offered to cells either as a single 2.5 mM step or as a ...

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

authors： Michelena P,García-Pérez LE,Artalejo AR,García AG

更新日期：1993-04-15 00:00:00

abstract：:The amphibian tetradecapeptide, bombesin (BBS) has been shown to stimulate insulin secretion both in vivo and by pancreatic islet cells in vitro. To determine whether BBS can act directly on pancreatic beta cells, we examined its effects on insulin secretion by HIT-T15 cells (HIT cells), a clonal islet cell line. Addi...

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

authors： Swope SL,Schonbrunn A

更新日期：1984-03-01 00:00:00

abstract：:The conditional lifetime expectancy function (LEF) is the expected lifetime of a subject given survival past a certain time point and the values of a set of explanatory variables. This function is attractive to researchers because it summarizes the entire residual life distribution and has an easy interpretation compa...

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

authors： Kong J,Klein BE,Klein R,Wahba G

更新日期：2015-09-29 00:00:00

abstract：:In vivo, G protein-coupled receptors (GPCR) for neurotransmitters undergo complex intracellular trafficking that contribute to regulate their abundance at the cell surface. Here, we report a previously undescribed alteration in the subcellular localization of D1 dopamine receptor (D1R) that occurs in vivo in striatal ...

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

authors： Dumartin B,Jaber M,Gonon F,Caron MG,Giros B,Bloch B

更新日期：2000-02-15 00:00:00

abstract：:A photolyzable derivative of dipeptidyl-tRNA, p-azido-N-tBoc-Phe-[3H]Phe-tRNA, bound reversibly to 70S ribosomes in the presence of poly(U), becomes, when irradiated, covalently attached to components of the 50S ribosomal subunit. Most of the reaction occurs within the 23S RNA, while ribosomal proteins are only weakly...

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

authors： Sonenberg N,Wilchek M,Zamir A

更新日期：1975-11-01 00:00:00

abstract：:We describe a single autoregulatory cassette that allows reversible induction of transgene expression in response to tetracycline (tet). This cassette contains all of the necessary components previously described by others on two separate plasmids that are introduced sequentially over a period of months [Gossen, M. & ...

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

authors： Hofmann A,Nolan GP,Blau HM

更新日期：1996-05-28 00:00:00

abstract：:An early and a late histone H2B gene from the sea urchin Stronglyocentrotus purpuratus were linked in a single plasmid and injected into the eggs of the sea urchin Lytechinus pictus. The levels of transcripts of injected early and late genes and of endogenous early genes were monitored during development by a ribonucl...

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

authors： Colin AM,Catlin TL,Kidson SH,Maxson R

更新日期：1988-01-01 00:00:00

abstract：:Ascorbic acid metabolism is associated with a number of mechanisms known to be involved in host resistance to malignant disease. Cancer patients are significantly depleted of ascorbic acid, and in our opinion this demonstrable biochemical characteristic indicates a substantially increased requirement and utilization o...

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

authors： Cameron E,Pauling L

更新日期：1976-10-01 00:00:00

abstract：:Escherichia coli cells treated with toluene replicate DNA when they are provided with deoxyribonucleoside 5'-triphosphates, ATP, Mg(++), and K(+). However, when deoxycytidine 5'-triphosphate is replaced by hydroxymethyl deoxycytidine 5'-triphosphate, incorporation of nucleotides into acid-precipitable material by tolu...

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

authors： Fleischman RA,Richardson CC

更新日期：1971-10-01 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 properties of a recently synthesized photolabile chelator for divalent cations are described, the affinity of which for Ca2+ changes by some 5 orders of magnitude on illumination. The compound 1-(2-nitro-4,5-dimethoxyphenyl)-N,N,N',N'-tetrakis[(oxycarbonyl)me thyl]-1,2-ethanediamine (DM-nitrophen) binds Ca2+ (Kd a...

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

authors： Kaplan JH,Ellis-Davies GC

更新日期：1988-09-01 00:00:00

abstract：:HLA-G is the putative natural killer (NK) cell inhibitory ligand expressed on the extravillous cytotrophoblast of the human placenta. Killing of the class I negative human B cell line 721.221 by NK cells is inhibited by the expression of HLA-G. This inhibition is dependent on a high level of HLA-G expression. In the p...

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

authors： Mandelboim O,Pazmany L,Davis DM,Valés-Gómez M,Reyburn HT,Rybalov B,Strominger JL

更新日期：1997-12-23 00:00:00

abstract：:When an unusually high frequency of an allele is encountered in a population, "founder effect" is often invoked as an explanation. As usually used, the term implies the disproportionate increase through chance (rather than selection) of an allele contributed to the population by a particular ancestor. While genetic th...

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

authors： Thompson EA,Neel JV

更新日期：1978-03-01 00:00:00

abstract：:We present data that demonstrate that three MR elements isolated from wild populations of Drosophila melanogaster on two continents can cause large deletions of the X chromosome in males. The deleted chromosomes, termed mini-X chromosomes, are induced at a frequency of approximately 1:4000 in chromosomes that are init...

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

authors： Green MM,Yamamoto MT,Miklos GL

更新日期：1987-07-01 00:00:00

abstract：:Coat components localize to specific membrane domains, where they sort selected transmembrane proteins. To study how clathrin coats are stabilized on such domains and to identify the protein networks involved, we combined proteomic screens and in vitro liposome-based assays that recapitulate the fidelity of protein so...

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

authors： Baust T,Czupalla C,Krause E,Bourel-Bonnet L,Hoflack B

更新日期：2006-02-28 00:00:00

abstract：:The substrate specificity of the catalytic subunit of rabbit skeletal muscle 3': 5'-cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP: protein phosphotransferase) has been studied using the synthetic peptide Arg-Gly-Tyr-Ser-Leu-Gly corresponding to the sequence around serine 24, a phosphorylation site in reduced, ...

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

authors： Kemp BE,Benjamini E,Krebs EG

更新日期：1976-04-01 00:00:00

abstract：:We describe a Xenopus mRNA, Xrel1, that is related to the avian protooncogene c-rel, the embryonic pattern gene dorsal of Drosophila, and the mammalian transcription factor NK-kappa B/KBF1. The sequence of Xrel1 is homologous to the other rel-related proteins in the large amino-terminal region that defines this class ...

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

authors： Kao KR,Hopwood ND

更新日期：1991-04-01 00:00:00