Pristine extraterrestrial material with unprecedented nitrogen isotopic variation.

abstract：:Both stem cells and mast cells express c-kit and proliferate after exposure to c-kit ligand. Mutations in c-kit may enhance or interfere with the ability of c-kit receptor to initiate the intracellular pathways resulting in cell proliferation. These observations suggested to us that mastocytosis might in some patients...

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

authors： Nagata H,Worobec AS,Oh CK,Chowdhury BA,Tannenbaum S,Suzuki Y,Metcalfe DD

更新日期：1995-11-07 00:00:00

abstract：:Cytochrome c peroxidase reacts with peroxide to form compound I, which contains an oxyferryl heme and an indolyl radical at Trp-191. The indolyl free radical has a half-life of several hours at room temperature, and this remarkable stability is essential for the catalytic function of cytochrome c peroxidase. To probe ...

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

authors： Miller MA,Han GW,Kraut J

更新日期：1994-11-08 00:00:00

abstract：:We describe a physical map of the end of the long arm of the human X chromosome encompassing the region from Xq27.2 to the q telomere, inclusive of the chromosomal band Xq28. This region is of particular interest, since it contains the highest density of genes associated with genetic diseases. The map covers a total o...

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

authors： Poustka A,Dietrich A,Langenstein G,Toniolo D,Warren ST,Lehrach H

更新日期：1991-10-01 00:00:00

abstract：:The crystal structure of DsRed, a red fluorescent protein from a corallimorpharian, has been determined at 2.0-A resolution by multiple-wavelength anomalous dispersion and crystallographic refinement. Crystals of the selenomethionine-substituted protein have space group P2(1) and contain a tetramer with 222 noncrystal...

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

authors： Yarbrough D,Wachter RM,Kallio K,Matz MV,Remington SJ

更新日期：2001-01-16 00:00:00

abstract：:Opportunistic infections are often polymicrobial. Two of the most important bacterial opportunistic pathogens of humans, Pseudomonas aeruginosa and Staphylococcus aureus, frequently are coisolated from infections of catheters, endotracheal tubes, skin, eyes, and the respiratory tract, including the airways of people w...

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

authors： Hoffman LR,Déziel E,D'Argenio DA,Lépine F,Emerson J,McNamara S,Gibson RL,Ramsey BW,Miller SI

更新日期：2006-12-26 00:00:00

abstract：:Preparations of the hemin-controlled repressor (HCR) from rabbit reticulocytes contain 3':5'-cyclic-AMP-independent protein kinase activity for the smallest subunit of the peptide initiation factor eIF-2 and for proteins of reticulocyte 40S ribosomal subunits. Binding of the ternary complex formed between Met-tRNAf, G...

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

authors： Kramer G,Henderson AB,Pinphanichakarn P,Wallis MH,Hardesty B

更新日期：1977-04-01 00:00:00

abstract：:Estimates of 21st Century global-mean surface temperature increase have generally been based on scenarios that do not include climate policies. Newly developed multigas mitigation scenarios, based on a wide range of modeling approaches and socioeconomic assumptions, now allow the assessment of possible impacts of clim...

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

authors： Van Vuuren DP,Meinshausen M,Plattner GK,Joos F,Strassmann KM,Smith SJ,Wigley TM,Raper SC,Riahi K,de la Chesnaye F,den Elzen MG,Fujino J,Jiang K,Nakicenovic N,Paltsev S,Reilly JM

更新日期：2008-10-07 00:00:00

abstract：:Nuclear lamins are components of the nuclear lamina, a structural scaffolding for the cell nucleus. Defects in lamins A and C cause an array of human diseases, including muscular dystrophy, lipodystrophy, and progeria, but no diseases have been linked to the loss of lamins B1 or B2. To explore the functional relevance...

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

authors： Coffinier C,Chang SY,Nobumori C,Tu Y,Farber EA,Toth JI,Fong LG,Young SG

更新日期：2010-03-16 00:00:00

abstract：:Branching morphogenesis in the mammary gland is achieved by the migration of epithelial cells through a microenvironment consisting of stromal cells and extracellular matrix (ECM). Here we show that galectin-1 (Gal-1), an endogenous lectin that recognizes glycans bearing N-acetyllactosamine (LacNAc) epitopes, induces ...

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

authors： Bhat R,Belardi B,Mori H,Kuo P,Tam A,Hines WC,Le QT,Bertozzi CR,Bissell MJ

更新日期：2016-08-16 00:00:00

abstract：:Dihydropteridine reductase (EC 1.6.99.7) is a member of the recently identified family of proteins known as short-chain dehydrogenases. When the x-ray structure of dihydropteridine reductase is correlated with conserved amino acid sequences characteristic of this enzyme class, two important common structural regions c...

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

authors： Varughese KI,Xuong NH,Kiefer PM,Matthews DA,Whiteley JM

更新日期：1994-06-07 00:00:00

abstract：:Efficient single nucleotide polymorphism (SNP) genotyping methods are necessary to accomplish many current gene discovery goals. A crucial element in large-scale SNP genotyping is the number of individual biochemical reactions that must be performed. An efficient method that can be used to simultaneously amplify a set...

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

authors： Jordan B,Charest A,Dowd JF,Blumenstiel JP,Yeh Rf RF,Osman A,Housman DE,Landers JE

更新日期：2002-03-05 00:00:00

abstract：:Genes carried by EcoRI endonuclease-generated fragments of Staphylococcus plasmid DNA have been covalently joined to the E. coli antibiotic-resistance plasmid pSC101, and the resulting hybrid molecules have been introduced into E. coli by transformation. The newly constructed plasmids replicate as biologically functio...

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

authors： Chang AC,Cohen SN

更新日期：1974-04-01 00:00:00

abstract：:Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is a hallmark of major depressive disorder. A number of studies have shown that this dysregulation is correlated with impaired forebrain glucocorticoid receptor (GR) function. To determine whether a primary, acquired deficit in forebrain GR signaling is an...

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

authors： Boyle MP,Brewer JA,Funatsu M,Wozniak DF,Tsien JZ,Izumi Y,Muglia LJ

更新日期：2005-01-11 00:00:00

abstract：:The Fas/APO-1 cytotoxic pathway plays an important role in the regulation of peripheral immunity. Recent evidence indicates that this regulatory function operates through deletion of activated T and B lymphocytes by CD4+ T cells expressing the Fas ligand. Because macrophages play a key role in peripheral immunity, we ...

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

authors： Ashany D,Song X,Lacy E,Nikolic-Zugic J,Friedman SM,Elkon KB

更新日期：1995-11-21 00:00:00

abstract：:NIH 3T3 mouse cells were transfected with plasmids that induce efficient expression of either (i) the Rous sarcoma virus v-src gene, (ii) the chicken c-src gene, or (iii) a recombinant gene combining the 5' portion of c-src with the 3' end of v-src. Focus formation in tissue culture and formation of large colonies in ...

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

authors： Shalloway D,Coussens PM,Yaciuk P

更新日期：1984-11-01 00:00:00

abstract：:Two major problems have to be solved in studies of genes near breakpoints of chromosome abnormalities and in large-scale genomic mapping projects: (i) the identification of genes within the large amount on nontranscribed DNA and (ii) the determination of the tissues in which the identified genes are transcribed. In si...

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

authors： Boehm T,Gonzalez-Sarmiento R,Kennedy M,Rabbitts TH

更新日期：1991-05-01 00:00:00

abstract：:The concept of a charge density wave (CDW) permeates much of condensed matter physics and chemistry. CDWs have their origin rooted in the instability of a one-dimensional system described by Peierls. The extension of this concept to reduced dimensional systems has led to the concept of Fermi surface nesting (FSN), whi...

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

authors： Zhu X,Cao Y,Zhang J,Plummer EW,Guo J

更新日期：2015-02-24 00:00:00

abstract：:Dendritic spines are of major importance in information processing and memory formation in central neurons. Estradiol has been shown to induce an increase of dendritic spine density on hippocampal neurons in vivo and in vitro. The neurotrophin brain-derived neurotrophic factor (BDNF) recently has been implicated in ne...

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

authors： Murphy DD,Cole NB,Segal M

更新日期：1998-09-15 00:00:00

abstract：:Direct reciprocity and conditional cooperation are important mechanisms to prevent free riding in social dilemmas. However, in large groups, these mechanisms may become ineffective because they require single individuals to have a substantial influence on their peers. However, the recent discovery of zero-determinant ...

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

authors： Hilbe C,Wu B,Traulsen A,Nowak MA

更新日期：2014-11-18 00:00:00

abstract：:In eukaryotes, transfer RNAs (tRNAs) are transcribed in the nucleus yet function in the cytoplasm; thus, tRNA movement within the cell was believed to be unidirectional--from the nucleus to the cytoplasm. It is now known that mature tRNAs also move in a retrograde direction from the cytoplasm to the nucleus via retrog...

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

authors： Kramer EB,Hopper AK

更新日期：2013-12-24 00:00:00

abstract：:A pure population of mast cells was obtained after 14 days of culturing mouse bone marrow cells in the presence of medium derived from concanavalin A-stimulated mouse spleen cells. The cells were characterized as mast cells by their morphologic appearance and histologic staining, by their histamine content (450 ng per...

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

authors： Razin E,Cordon-Cardo C,Good RA

更新日期：1981-04-01 00:00:00

abstract：:Explaining the maintenance of tropical forest diversity under the countervailing forces of drift and competition poses a major challenge to ecological theory. Janzen-Connell effects, in which host-specific natural enemies restrict the recruitment of juveniles near conspecific adults, provide a potential mechanism. Jan...

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

authors： Levi T,Barfield M,Barrantes S,Sullivan C,Holt RD,Terborgh J

更新日期：2019-01-08 00:00:00

abstract：:Peptide nucleic acid (PNA) is a DNA mimic that has shown considerable promise as a lead compound for developing gene therapeutic drugs. We report that PNAs targeted to functional and accessible sites in ribosomal RNA can inhibit translation in an Escherichia coli cell-free transcription/translation system, with 50% re...

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

authors： Good L,Nielsen PE

更新日期：1998-03-03 00:00:00

abstract：:Angiogenesis restores blood flow to healing tissues, a process that is inhibited by high doses of glucocorticoids. However, the role of endogenous glucocorticoids and the potential for antiglucocorticoid therapy to enhance angiogenesis is unknown. Using in vitro and in vivo models of angiogenesis in mice, we examined ...

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

authors： Small GR,Hadoke PW,Sharif I,Dover AR,Armour D,Kenyon CJ,Gray GA,Walker BR

更新日期：2005-08-23 00:00:00

abstract：:Asexual freshwater planarians reproduce by tearing themselves into two pieces by a process called binary fission. The resulting head and tail pieces regenerate within about a week, forming two new worms. Understanding this process of ripping oneself into two parts poses a challenging biomechanical problem. Because pla...

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

authors： Malinowski PT,Cochet-Escartin O,Kaj KJ,Ronan E,Groisman A,Diamond PH,Collins ES

更新日期：2017-10-10 00:00:00

abstract：:Mechanisms that enabled primitive cell membranes to self-reproduce have been discussed based on the physicochemical properties of fatty acids; however, there must be a transition to modern cell membranes composed of phospholipids [Budin I, Szostak JW (2011) Proc Natl Acad Sci USA 108:5249-5254]. Thus, a growth-divisio...

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

authors： Terasawa H,Nishimura K,Suzuki H,Matsuura T,Yomo T

更新日期：2012-04-17 00:00:00

abstract：:Our research addresses the relationship between subnuclear localization and gene expression in fission yeast. We observed the relocalization of a heterochromatic region, the mating-type region, from its natural location at the spindle-pole body to the immediate vicinity of the nucleolus. Relocalization occurred in res...

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

authors： Jakociunas T,Domange Jordö M,Aït Mebarek M,Bünner CM,Verhein-Hansen J,Oddershede LB,Thon G

更新日期：2013-11-19 00:00:00

abstract：:Changes in the amount, intensity, and timing of precipitation are increasing hydrologic variability in many regions, but we have little understanding of how these changes are affecting freshwater species. Stream-breeding amphibians-a diverse group in North America-may be particularly sensitive to hydrologic variabilit...

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

authors： Lowe WH,Swartz LK,Addis BR,Likens GE

更新日期：2019-09-24 00:00:00

abstract：:The human foamy virus (HFV) genome possesses three open reading frames (bel 1, 2, and 3) located between env and the 3' long terminal repeat. By analogy to other human retroviruses this region was selected as the most likely candidate to encode the viral transactivator. Results presented here confirmed this and showed...

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

authors： Rethwilm A,Erlwein O,Baunach G,Maurer B,ter Meulen V

更新日期：1991-02-01 00:00:00

abstract：:The patch-clamp technique allows currents to be recorded through single ion channels in patches of cell membrane in the tips of glass pipettes. When recording, voltage is typically applied across the membrane patch to drive ions through open channels and to probe the voltage-sensitivity of channel activity. In this st...

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

authors： Gil Z,Silberberg SD,Magleby KL

更新日期：1999-12-07 00:00:00