Synthetic routes contaminate graphene materials with a whole spectrum of unanticipated metallic elements.

abstract：:The oxygenation of the atmosphere ∼2.45-2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth's redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which re...

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

authors： Chi Fru E,Rodríguez NP,Partin CA,Lalonde SV,Andersson P,Weiss DJ,El Albani A,Rodushkin I,Konhauser KO

更新日期：2016-05-03 00:00:00

abstract：:The sporulation of Saccharomyces cerevisiae in the presence of [2-13C]acetate was studied by 13C NMR spectroscopy. The fate of 13C label was analyzed in vivo and in cell extracts. During the first 4 hr of sporulation the major metabolite produced from [2-13C]acetate utilization was glutamate. From the labeling pattern...

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

authors： Dickinson JR,Dawes IW,Boyd AS,Baxter RL

更新日期：1983-10-01 00:00:00

abstract：:Increasing concentrations of estradiol (E2) ranging from 0.01 to 10 nM were found to inhibit partially but significantly the lactogenic effect of ovine prolactin (oPRL) on alpha-lactalbumin production in primate mammary tissues maintained in organ culture for 9 days. E2 at 10 nM inhibited by 38% (mean) PRL-stimulated ...

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

authors： Kleinberg DL,Todd J,Babitsky G

更新日期：1983-07-01 00:00:00

abstract：:Adult rats were trained to detect the occurrence of a two-element sound sequence in a background of nine other nontarget sound pairs. Training resulted in a modest, enduring, static expansion of the cortical areas of representation of both target stimulus sounds. More importantly, once the initial stimulus A in the ta...

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

authors： Zhou X,de Villers-Sidani E,Panizzutti R,Merzenich MM

更新日期：2010-08-17 00:00:00

abstract：:Infectious tolerance describes the process of CD4(+) regulatory T cells (Tregs) converting naïve T cells to become additional Tregs. We show that antigen-specific Tregs induce, within skin grafts and dendritic cells, the expression of enzymes that consume at least 5 different essential amino acids (EAAs). T cells fail...

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

authors： Cobbold SP,Adams E,Farquhar CA,Nolan KF,Howie D,Lui KO,Fairchild PJ,Mellor AL,Ron D,Waldmann H

更新日期：2009-07-21 00:00:00

abstract：:The interrelationships of hexose feeding and insulin action were studied in the Chinese hamster fibroblast cell lines 023 and DS-7. The latter, derived from 023 and deficient in phosphoglucose isomerase, has been used to map the metabolic requirements for aldohexose-mediated down-regulation or "curbing" of hexose tran...

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

authors： Wilson C,Peterson SW,Ullrey DB,Kalckar HM

更新日期：1986-06-01 00:00:00

abstract：:Cytochrome P450 monooxygenases (P450) in the honey bee, Apis mellifera, detoxify phytochemicals in honey and pollen. The flavonol quercetin is found ubiquitously and abundantly in pollen and frequently at lower concentrations in honey. Worker jelly consumed during the first 3 d of larval development typically contains...

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

authors： Mao W,Schuler MA,Berenbaum MR

更新日期：2017-03-07 00:00:00

abstract：:The brain continuously influences and perceives the physiological condition of the body. Related cortical representations have been proposed to shape emotional experience and guide behavior. Although previous studies have identified brain regions recruited during autonomic processing, neurological lesion studies have ...

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

authors： Guo CC,Sturm VE,Zhou J,Gennatas ED,Trujillo AJ,Hua AY,Crawford R,Stables L,Kramer JH,Rankin K,Levenson RW,Rosen HJ,Miller BL,Seeley WW

更新日期：2016-04-26 00:00:00

abstract：:Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of...

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

authors： Jang SW,Liu X,Yepes M,Shepherd KR,Miller GW,Liu Y,Wilson WD,Xiao G,Blanchi B,Sun YE,Ye K

更新日期：2010-02-09 00:00:00

abstract：:Innate immunity can facilitate nervous system regeneration, yet the underlying cellular and molecular mechanisms are not well understood. Here we show that intraocular injection of lipopolysaccharide (LPS), a bacterial cell wall component, or the fungal cell wall extract zymosan both lead to rapid and comparable intra...

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

authors： Baldwin KT,Carbajal KS,Segal BM,Giger RJ

更新日期：2015-02-24 00:00:00

abstract：:The UV photodissociation kinetics of tryptophan amino acid, Trp, attached to the membrane of bacteria, Escherichia coli and Bacillus subtilis, have been studied by means of normal and synchronous fluorescence. Our experimental data suggest that the fluorescence intensity of Trp increases during the first minute of irr...

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

authors： Li R,Dhankhar D,Chen J,Cesario TC,Rentzepis PM

更新日期：2019-09-17 00:00:00

abstract：:For centuries ecologists have studied how the diversity and functional traits of plant and animal communities vary across biomes. In contrast, we have only just begun exploring similar questions for soil microbial communities despite soil microbes being the dominant engines of biogeochemical cycles and a major pool of...

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

authors： Fierer N,Leff JW,Adams BJ,Nielsen UN,Bates ST,Lauber CL,Owens S,Gilbert JA,Wall DH,Caporaso JG

更新日期：2012-12-26 00:00:00

abstract：:Whole-cell voltage clamp was used to investigate the properties and spatial distribution of fast-deactivating (FD) Ca channels in squid giant fiber lobe (GFL) neurons. Squid FD Ca channels are reversibly blocked by the spider toxin omega-Agatoxin IVA with an IC50 of 240-420 nM with no effect on the kinetics of Ca chan...

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

authors： McFarlane MB,Gilly WF

更新日期：1996-05-14 00:00:00

abstract：:The extensive intratumor heterogeneity revealed by sequencing cancer genomes is an essential determinant of tumor progression, diagnosis, and treatment. What maintains heterogeneity remains an open question because competition within a tumor leads to a strong selection for the fittest subclone. Cancer cells also coope...

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

authors： Archetti M,Ferraro DA,Christofori G

更新日期：2015-02-10 00:00:00

abstract：:Biological membranes are complex, self-organized structures that define boundaries and compartmentalize space in living matter. Composed of a wide variety of lipid and protein molecules, these responsive surfaces mediate transmembrane signaling and material transport within the cell and with its environment. It is wel...

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

authors： Watkins EB,Miller CE,Majewski J,Kuhl TL

更新日期：2011-04-26 00:00:00

abstract：:Mitochondrial membrane potentials and resistances have been determined under various metabolic conditions by the use of piezoelectric-driven microelectrodes. The mean state 3 potentials (about +19 mv) are higher than the potentials in state 4 (about +9 mv). DNP in uncoupling concentrations or KCN have no significant e...

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

authors： Tupper JT,Tedeschi H

更新日期：1969-07-01 00:00:00

abstract：:Noninvasive prenatal testing using fetal DNA in maternal plasma is an actively researched area. The current generation of tests using massively parallel sequencing is based on counting plasma DNA sequences originating from different genomic regions. In this study, we explored a different approach that is based on the ...

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

authors： Yu SC,Chan KC,Zheng YW,Jiang P,Liao GJ,Sun H,Akolekar R,Leung TY,Go AT,van Vugt JM,Minekawa R,Oudejans CB,Nicolaides KH,Chiu RW,Lo YM

更新日期：2014-06-10 00:00:00

abstract：:Translational initiation factor 2 (IF2) is a guanine nucleotide-binding protein that can bind guanosine 3',5'-(bis) diphosphate (ppGpp), an alarmone involved in stringent response in bacteria. In cells growing under optimal conditions, the GTP concentration is very high, and that of ppGpp very low. However, under stre...

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

authors： Milon P,Tischenko E,Tomsic J,Caserta E,Folkers G,La Teana A,Rodnina MV,Pon CL,Boelens R,Gualerzi CO

更新日期：2006-09-19 00:00:00

abstract：:The major obstacle to the study of functional/structural interrelationships of spinach chloroplasts by using spin labels has been the rapid loss of the electron paramagnetic resonance (EPR) signals upon illumination with visible light. The present study demonstrates that the addition of ferredoxin and NADP+ in the pre...

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

authors： Sun AS,Calvin M

更新日期：1975-08-01 00:00:00

abstract：:Aneuploidy, a chromosome content other than a multiple of the haploid number, is a common feature of cancer cells. Whole chromosomal aneuploidy accompanying ongoing chromosomal instability in mice resulting from reduced levels of the centromere-linked motor protein CENP-E has been reported to increase the incidence of...

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

authors： Silk AD,Zasadil LM,Holland AJ,Vitre B,Cleveland DW,Weaver BA

更新日期：2013-10-29 00:00:00

abstract：:One of the major surprises of the molecular analysis of major histocompatibility complex (MHC) genes is the large number of class I (K/D)-related sequences in the genome. Both restriction fragment length polymorphisms and cosmid cloning experiments showed them all to be closely linked to the MHC. Until now little info...

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

authors： Schepart BS,Woodward JG,Palmer MJ,Macchi MJ,Basta P,McLaughlin-Taylor E,Frelinger JA

更新日期：1985-08-01 00:00:00

abstract：:Trypanosomosis, or sleeping sickness, is a major disease constraint on livestock productivity in sub-Saharan Africa. To identify quantitative trait loci (QTL) controlling resistance to trypanosomosis in cattle, an experimental cross was made between trypanotolerant African N'Dama (Bos taurus) and trypanosusceptible im...

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

authors： Hanotte O,Ronin Y,Agaba M,Nilsson P,Gelhaus A,Horstmann R,Sugimoto Y,Kemp S,Gibson J,Korol A,Soller M,Teale A

更新日期：2003-06-24 00:00:00

abstract：:The MAK16 gene was first defined as a gene whose mutation resulted in loss of M1 double-stranded RNA virus-like particles. The mak16-1 mutation also produces temperature-sensitive cell growth. We report here that mak16-1 cells arrest at the nonpermissive temperature in G1 phase, such that they are mating competent. We...

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

authors： Wickner RB

更新日期：1988-08-01 00:00:00

abstract：:Within the scientific community, much attention has focused on improving communications between scientists, policy makers, and the public. To date, efforts have centered on improving the content, accessibility, and delivery of scientific communications. Here we argue that in the current political and media environment...

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

authors： Iyengar S,Massey DS

更新日期：2019-04-16 00:00:00

abstract：:Newly formed hepatic granulomas around Schistosoma mansoni eggs become progressively smaller during the chronic (greater than or equal to 15 weeks after infection) phase of the disease. This reduction in granuloma size, termed "modulation," is known to be caused in part by a T lymphocyte that can adoptively transfer m...

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

authors： Green WF,Colley DG

更新日期：1981-02-01 00:00:00

abstract：:Negative-stranded RNA viruses cover their genome with nucleoprotein (N) to protect it from the human innate immune system. Abrogation of the function of N offers a unique opportunity to combat the spread of the viruses. Here, we describe a unique fold of N from Leanyer virus (LEAV, Orthobunyavirus genus, Bunyaviridae ...

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

authors： Niu F,Shaw N,Wang YE,Jiao L,Ding W,Li X,Zhu P,Upur H,Ouyang S,Cheng G,Liu ZJ

更新日期：2013-05-28 00:00:00

abstract：:Efforts are underway to construct several recoded genomes anticipated to exhibit multivirus resistance, enhanced nonstandard amino acid (nsAA) incorporation, and capability for synthetic biocontainment. Although our laboratory pioneered the first genomically recoded organism (Escherichia coli strain C321.∆A), its fitn...

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

authors： Wannier TM,Kunjapur AM,Rice DP,McDonald MJ,Desai MM,Church GM

更新日期：2018-03-20 00:00:00

abstract：:The E6 protein of the high-risk human papillomaviruses inactivates the tumor suppressor protein p53 by stimulating its ubiquitinylation and subsequent degradation. Ubiquitinylation is a multistep process involving a ubiquitin-activating enzyme, one of many distinct ubiquitin-conjugating enzymes, and in certain cases, ...

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

authors： Rolfe M,Beer-Romero P,Glass S,Eckstein J,Berdo I,Theodoras A,Pagano M,Draetta G

更新日期：1995-04-11 00:00:00

abstract：:The high-potential iron-sulfur center associated with the g = 1.89-1.90 electron paramagnetic resonance signal in spinach chloroplasts is fully reduced in the dark. It is photooxidized in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea and reduced after illumination with red actinic light in the absence of inh...

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

authors： Whitmarsh J,Cramer WA

更新日期：1979-09-01 00:00:00

abstract：:A recently determined set of 20 NMR-derived conformations of a 48-residue all-alpha-helical protein, (PDB ID code 2JVD), is validated here by comparing the observed (13)C(alpha) chemical shifts with those computed at the density functional level of theory. In addition, a recently introduced physics-based method, aimed...

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

authors： Vila JA,Aramini JM,Rossi P,Kuzin A,Su M,Seetharaman J,Xiao R,Tong L,Montelione GT,Scheraga HA

更新日期：2008-09-23 00:00:00