Evolutionary dynamics of Clostridium difficile over short and long time scales.

abstract：:Immediately after focal retinal lesions, receptive fields (RFs) in primary visual cortex expand considerably, even when the retinal damage is limited to the photoreceptor layer. The time course of these changes suggests that mere lack of stimulation in the vicinity of the RF accompanied by stimulation in the surroundi...

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

authors： Pettet MW,Gilbert CD

更新日期：1992-09-01 00:00:00

abstract：:Public responses where identical T cell receptors (TCRs) are clonally dominant and shared between different individuals are a common characteristic of CD8(+) T cell-mediated immunity. Focusing on TCR sharing, we analyzed approximately 3,400 TCR beta chains (TCRbetas) from mouse CD8(+) T cells responding to the influen...

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

authors： Venturi V,Kedzierska K,Price DA,Doherty PC,Douek DC,Turner SJ,Davenport MP

更新日期：2006-12-05 00:00:00

abstract：:Persephin (Pspn), a recently cloned member of the transforming growth factor-beta superfamily (TGF-beta) and glial cell line-derived neurotrophic factor (GDNF) subfamily, is distributed throughout the nervous system at extremely low levels and is thought to function as a survival factor for midbrain dopaminergic and s...

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

authors： Tomac AC,Agulnick AD,Haughey N,Chang CF,Zhang Y,Bäckman C,Morales M,Mattson MP,Wang Y,Westphal H,Hoffer BJ

更新日期：2002-07-09 00:00:00

abstract：:Since the end of World War II, much evidence has accrued of the primary phase of village-farming community life in Southwestern Asia, which began about 7000 B.C. The remains of (usually) several of the positively domesticated animals (dog, sheep, goat, pig) and plants (wheat, barley, legumes such as peas and lentils) ...

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

authors： Braidwood RJ,Cambel H,Redman CL,Watson PJ

更新日期：1971-06-01 00:00:00

abstract：:Inhibition of eicosanoid formation in larvae of the tobacco hornworm Manduca sexta, using specific inhibitors of phospholipase A2, cyclooxygenase, and lipoxygenase, severely weakened the ability of larvae to clear the bacterium Serratia marscescens from their hemolymph. The reduced capability to remove bacteria is ass...

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

authors： Stanley-Samuelson DW,Jensen E,Nickerson KW,Tiebel K,Ogg CL,Howard RW

更新日期：1991-02-01 00:00:00

abstract：:The yeast SIN1 protein is a nuclear protein that together with other proteins behaves as a transcriptional repressor of a family of genes. In addition, sin1 mutants are defective in proper mitotic chromosome segregation. In an effort to understand the basis for these phenotypes, we employed the yeast two-hybrid system...

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

authors： Shpungin S,Liberzon A,Bangio H,Yona E,Katcoff DJ

更新日期：1996-08-06 00:00:00

abstract：:The oxazolidinones represent the first new class of antibiotics to enter into clinical usage within the past 30 years, but their binding site and mechanism of action has not been fully characterized. We have determined the crystal structure of the oxazolidinone linezolid bound to the Deinococcus radiodurans 50S riboso...

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

authors： Wilson DN,Schluenzen F,Harms JM,Starosta AL,Connell SR,Fucini P

更新日期：2008-09-09 00:00:00

abstract：:Biomimetic nanopores based on membrane-spanning single-walled carbon nanotubes have been designed to include selectivity filters based on combinations of anionic and cationic groups mimicking those present in bacterial porins and in voltage-gated sodium and calcium channels. The ion permeation and selectivity properti...

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

authors： García-Fandiño R,Sansom MS

更新日期：2012-05-01 00:00:00

abstract：:An in vitro enzyme system for the conversion of amino acid to oxime in the biosynthesis of glucosinolates has been established by the combined use of an improved isolation medium and jasmonic acid-induced etiolated seedlings of Sinapis alba L. An 8-fold induction of de novo biosynthesis of the L-tyrosine-derived p-hyd...

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

authors： Du L,Lykkesfeldt J,Olsen CE,Halkier BA

更新日期：1995-12-19 00:00:00

abstract：:Water freezing on solid surfaces is ubiquitous in nature. Even though icing/frosting impairs the performance and safety in many processes, its mechanism remains inadequately understood. Changing atmospheric conditions, surface properties, the complexity of icing physics, and the unorthodox behavior of water are the pr...

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

authors： Jung S,Tiwari MK,Poulikakos D

更新日期：2012-10-02 00:00:00

abstract：:The complete nucleotide sequence of the gene for the specific glycoprotein (gp55) of the polycythemic strain of Friend spleen focus-forming virus (SFFV) was derived from the cloned SFFV DNA intermediate. The gp55 gene is present within 1.4 kilobases of the 5' side of the 3'long terminal repeat sequence. The open readi...

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

authors： Amanuma H,Katori A,Obata M,Sagata N,Ikawa Y

更新日期：1983-07-01 00:00:00

abstract：:The utilization of the isoaccepting species of leucyl-tRNA in protein synthesis has been examined in E. coli. Two minor leucyl-tRNA species, isoacceptors tRNA3Leu and tRNA4Leu, are the predominant species found bound to ribosomes during exponential growth in minimal medium. In rich medium, an increased proportion of t...

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

authors： Holmes WM,Goldman E,Miner TA,Hatfield GW

更新日期：1977-04-01 00:00:00

abstract：:The DNA binding activity of p53 is crucial for its tumor suppressor function and is subject to tight regulation. Previous studies revealed that the inhibitory function of the p53 C terminus is implicated in the latent, low affinity sequence-specific DNA binding activity of p53 in the uninduced state. Sequence-specific...

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

authors： Müller-Tiemann BF,Halazonetis TD,Elting JJ

更新日期：1998-05-26 00:00:00

abstract：:Excited states of proteins may play important roles in function, yet are difficult to study spectroscopically because of their sparse population. High hydrostatic pressure increases the equilibrium population of excited states, enabling their characterization [Akasaka K (2003) Biochemistry 42:10875-85]. High-pressure ...

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

authors： Lerch MT,Horwitz J,McCoy J,Hubbell WL

更新日期：2013-12-03 00:00:00

abstract：:The antimicrobial peptide hepcidin appears to play a central role in the regulation of iron homeostasis. In intact animals, iron overload or the injection of lipopolysaccharide (LPS) stimulates transcription of HAMP, the gene that encodes hepcidin. In isolated hepatocytes, IL-6, an inflammatory cytokine the production...

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

authors： Lee P,Peng H,Gelbart T,Beutler E

更新日期：2004-06-22 00:00:00

abstract：:Ca2+ influx through voltage-gated Ca2+ channels and the resulting elevation of intracellular Ca2+ concentration, [Ca2+]i, triggers transmitter release in nerve terminals. However, it is controversial whether in addition to the opening of Ca2+ channels, membrane potential directly affects transmitter release. Here, we ...

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

authors： Felmy F,Neher E,Schneggenburger R

更新日期：2003-12-09 00:00:00

abstract：:Sonicated rabbit-liver chromatin is fractionated by ion-exchange chromatography on ECTHAM-cellulose, a weakly cationic adsorbent. The chromatographic procedure provides a series of fractions having a spectrum of thermal denaturation profiles. The earliest-eluting fractions melt cooperatively at a significantly higher ...

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

authors： Reeck GR,Simpson RT,Sober HA

更新日期：1972-08-01 00:00:00

abstract：:Amino-terminal sequence determinations are reported of the subunits of biliproteins of prokaryotic unicellular and filamentous cyanobacteria and of eukaryotic unicellular red algae. The biliproteins examined, allophycocyanin, C-phycocyanin, R-phycocyanin, b-phycoerythrin, and phycoerythrocyanin, vary with respect to t...

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

authors： Glazer AN,Apell GS,Hixson CS,Bryant DA,Rimon S,Brown DM

更新日期：1976-02-01 00:00:00

abstract：:We describe the partial purification of an endonuclease from calf thymus that nicks phage PM2 DNA irradiated with UV doses producing only a few pyrimidine dimers per molecule. It has much less activity on DNA that has been subjected to enzymatic photoreactivation after UV irradiation. The calf thymus endonuclease is d...

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

authors： Waldstein EA,Peller S,Setlow RB

更新日期：1979-08-01 00:00:00

abstract：:cDNA clones for the (S)-tetrahydroberberine (H4Ber) oxidase of cultured berberine-producing Coptis japonica cells were isolated by screening a C. japonica cDNA library with synthetic nucleotides that can encode the NH2-terminal sequence of this enzyme. Analyses of the nucleotide sequences of the cloned cDNA inserts re...

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

authors： Okada N,Koizumi N,Tanaka T,Ohkubo H,Nakanishi S,Yamada Y

更新日期：1989-01-01 00:00:00

abstract：:The chemical speciation of arsenic in sediments and porewaters of aquifers is the critical factor that determines whether dissolved arsenic accumulates to potentially toxic levels. Sequestration of arsenic in solid phases, which may occur by adsorption or precipitation processes, controls dissolved concentrations. We ...

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

authors： O'Day PA,Vlassopoulos D,Root R,Rivera N

更新日期：2004-09-21 00:00:00

abstract：:p21Sdi1 (also known as Cip1 and Waf1), an inhibitor of DNA synthesis cloned from senescent human fibroblasts, is an inhibitor of G1 cyclin-dependent kinases (Cdks) in vitro and is transcriptionally regulated by wild-type p53. In addition, p21Sdi1 has been found to inhibit DNA replication by direct interaction with pro...

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

authors： Nakanishi M,Adami GR,Robetorye RS,Noda A,Venable SF,Dimitrov D,Pereira-Smith OM,Smith JR

更新日期：1995-05-09 00:00:00

abstract：:A model is presented for age-specific selection on the genotypes in a population. Each genotype is assigned a life table that specifies the viability and fecundity of its age classes. Breeding and reproduction occur at regular intervals, and generations overlap. Examples were generated on a digital computer. Gene freq...

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

authors： Anderson WW,King CE

更新日期：1970-07-01 00:00:00

abstract：:Hitherto it has not been possible to obtain spore and stalk cell differentiation of the cellular slime molds in submerged cultures. It is shown here that cells, when placed in roller tubes under an atmosphere of oxygen, will form clumps and differentiate in 48-72 hr into mature spores and stalk cells. Although differe...

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

authors： Sternfeld J,Bonner JT

更新日期：1977-01-01 00:00:00

abstract：:Human activities increasingly take place in online environments, providing novel opportunities for relating individual behaviors to population-level outcomes. In this paper, we introduce a simple generative model for the collective behavior of millions of social networking site users who are deciding between different...

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

authors： Gleeson JP,Cellai D,Onnela JP,Porter MA,Reed-Tsochas F

更新日期：2014-07-22 00:00:00

abstract：:We have carried out free energy perturbation calculations on DNA double-stranded hexanucleotides. The sequence d(CGCGCG)2 has been "mutated" into d(CGTGCG).d(CGCACG) with the oligonucleotide in the A, B, and Z structural forms, both in vacuo and in aqueous solution. In addition, model free energy calculations have bee...

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

authors： Dang LX,Pearlman DA,Kollman PA

更新日期：1990-06-01 00:00:00

abstract：:The growth of actin filament networks is a fundamental biological process that drives a variety of cellular and intracellular motions. During motility, eukaryotic cells and intracellular pathogens are propelled by actin networks organized by nucleation-promoting factors that trigger the formation of nascent filaments ...

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

authors： Shaevitz JW,Fletcher DA

更新日期：2007-10-02 00:00:00

abstract：:Plasmids that contain synthetic genes coding for small oligoribonucleotides called external guide sequences (EGSs) have been introduced into strains of Escherichia coli harboring antibiotic resistance genes. The EGSs direct RNase P to cleave the mRNAs transcribed from these genes thereby converting the phenotype of dr...

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

authors： Guerrier-Takada C,Salavati R,Altman S

更新日期：1997-08-05 00:00:00

abstract：:A temperature-sensitive (ts) mutant, GA 907/7, was isolated after mutagen treatment of avian myeloblastosis virus. When bone marrow cells or secondary yolk sac macrophages were infected with GA 907/7, the expression of transformation was greatly reduced at 41 degrees C. The results of temperature-shift experiments sug...

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

authors： Moscovici MG,Moscovici C

更新日期：1983-03-01 00:00:00

abstract：:Expression of luminescence in Escherichia coli was recently achieved by cloning genes from the marine bacterium Vibrio fischeri. One DNA fragment on a hybrid plasmid encoded regulatory functions and enzymatic activities necessary for light production. We report the results of a genetic analysis to identify the lumines...

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

authors： Engebrecht J,Silverman M

更新日期：1984-07-01 00:00:00