Intraclonal generation of antibody mutants in germinal centres.

abstract：:Solitons are large-amplitude, spatially confined wave packets in nonlinear media. They occur in a wide range of physical systems, such as water surfaces, optical fibres, plasmas, Bose-Einstein condensates and magnetically ordered media. A distinguishing feature of soliton behaviour that is common to all systems, is th...

journal_title：Nature

authors： Demokritov SO,Serga AA,Demidov VE,Hillebrands B,Kostylev MP,Kalinikos BA

更新日期：2003-11-13 00:00:00

abstract：:Understanding ice sheet behaviour in the geological past is essential for evaluating the role of the cryosphere in the climate system and for projecting rates and magnitudes of sea level rise in future warming scenarios1-4. Although both geological data5-7 and ice sheet models3,8 indicate that marine-based sectors of ...

journal_title：Nature

authors： Wilson DJ,Bertram RA,Needham EF,van de Flierdt T,Welsh KJ,McKay RM,Mazumder A,Riesselman CR,Jimenez-Espejo FJ,Escutia C

更新日期：2018-09-01 00:00:00

abstract：:Adenylyl cyclase is the prototypical second messenger generator. Nearly all of the eight cloned adenylyl cyclases are regulated by one or other arm of the phospholipase C pathway. Functional and ultrastructural investigations have shown that adenylyl cyclases are intimately associated with sites of calcium ion entry i...

journal_title：Nature

authors： Cooper DM,Mons N,Karpen JW

更新日期：1995-03-30 00:00:00

abstract：:A paramutation is an epigenetic interaction between two alleles of a locus, through which one allele induces a heritable modification in the other allele without modifying the DNA sequence. The paramutated allele itself becomes paramutagenic, that is, capable of epigenetically converting a new paramutable allele. Here...

journal_title：Nature

authors： de Vanssay A,Bougé AL,Boivin A,Hermant C,Teysset L,Delmarre V,Antoniewski C,Ronsseray S

更新日期：2012-10-04 00:00:00

abstract：:CDKN2A (INK4a/ARF) is frequently disrupted in various types of human cancer, and germline mutations of this locus can confer susceptibility to melanoma and other tumours. However, because CDKN2A encodes two distinct cell cycle inhibitory proteins, p16INK4a and p14ARF (p19Arf in mice), the mechanism of tumour suppressi...

journal_title：Nature

authors： Krimpenfort P,Quon KC,Mooi WJ,Loonstra A,Berns A

更新日期：2001-09-06 00:00:00

abstract：:In the chick embryo hindbrain, morphological segmentation into rhombomeres is matched by metameric patterns of early neuronal differentiation and axonogenesis. Boundaries between rhombomeres coincide with boundaries of expression of murine regulatory genes. By clonal analysis using intracellular marking, we show here ...

journal_title：Nature

authors： Fraser S,Keynes R,Lumsden A

更新日期：1990-03-29 00:00:00

abstract：:(Na+ + K+)ATPase contains two different subunits, a catalytic subunit (alpha) and a subunit with uncertain function (beta). The enzyme binds ATP, ouabain and vanadate, and can be phosphorylated by ATP as well as by inorganic phosphate. From the previously reported maximal binding and phosphorylation capacities of 3.5-...

journal_title：Nature

authors： Peters WH,Swarts HG,de Pont JJ,Schuurmans Stekhoven FM,Bonting SL

更新日期：1981-03-26 00:00:00

abstract：:Some observations suggest that very massive stars experience extreme mass-loss episodes shortly before they explode as supernovae, as do several models. Establishing a causal connection between these mass-loss episodes and the final explosion would provide a novel way to study pre-supernova massive-star evolution. Her...

journal_title：Nature

authors： Ofek EO,Sullivan M,Cenko SB,Kasliwal MM,Gal-Yam A,Kulkarni SR,Arcavi I,Bildsten L,Bloom JS,Horesh A,Howell DA,Filippenko AV,Laher R,Murray D,Nakar E,Nugent PE,Silverman JM,Shaviv NJ,Surace J,Yaron O

更新日期：2013-02-07 00:00:00

abstract：:The structure of the operator-binding domain of the lambda repressor has been determined at 3.2 A resolution. This domain contains an extended N-terminal arm and five alpha-helices. Model-building studies of the repressor-operator complex suggest that alpha-helices, especially the N-terminal parts of these helices, ma...

journal_title：Nature

authors： Pabo CO,Lewis M

更新日期：1982-07-29 00:00:00

abstract：:D-type cyclins, in association with the cyclin-dependent kinases Cdk4 or Cdk6, promote progression through the G1 phase of the cell cycle by phosphorylating the retinoblastoma protein (RB). The activities of Cdk4 and Cdk6 are constrained by inhibitors such as p16, the product of the CDKN2 gene on human chromosome 9p21...

journal_title：Nature

authors： Lukas J,Parry D,Aagaard L,Mann DJ,Bartkova J,Strauss M,Peters G,Bartek J

更新日期：1995-06-08 00:00:00

abstract：:Geochemical data from ancient sedimentary successions provide evidence for the progressive evolution of Earth's atmosphere and oceans. Key stages in increasing oxygenation are postulated for the Palaeoproterozoic era (∼2.3 billion years ago, Gyr ago) and the late Proterozoic eon (about 0.8 Gyr ago), with the latter im...

journal_title：Nature

authors： Parnell J,Boyce AJ,Mark D,Bowden S,Spinks S

更新日期：2010-11-11 00:00:00

abstract：:The accumulation of somatic DNA damage has been implicated as a cause of ageing in metazoa. One possible mechanism by which increased DNA damage could lead to cellular degeneration and death is by stochastic deregulation of gene expression. Here we directly test for increased transcriptional noise in aged tissue by di...

journal_title：Nature

authors： Bahar R,Hartmann CH,Rodriguez KA,Denny AD,Busuttil RA,Dollé ME,Calder RB,Chisholm GB,Pollock BH,Klein CA,Vijg J

更新日期：2006-06-22 00:00:00

abstract：:A model catalyst is described which has properties in common with carbonic anhydrase. The model demonstrates the availability of a mechanism, previously only hypothetical, for the action of the enzyme. It also shows, however, that this mechanism alone is not adequate to produce the high activity of the enzyme. ...

journal_title：Nature

authors： Woolley P

更新日期：1975-12-25 00:00:00

abstract：: ...

journal_title：Nature

authors： Jia H

更新日期：2018-11-01 00:00:00

abstract：:Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically dif...

journal_title：Nature

authors： Lovley DR,Woodward JC,Chapelle FH

更新日期：1994-07-14 00:00:00

abstract：:Understanding the fluctuations in marine fish stocks is important for the management of fisheries, and attempts have been made to demonstrate links with oceanographic and climatic variability, including the North Atlantic Oscillation (NAO). The NAO has been correlated with a range of long-term ecological measures, inc...

journal_title：Nature

authors： Attrill MJ,Power M

更新日期：2002-05-16 00:00:00

abstract：:Sleep has been assumed to be necessary for development and to be a vital function in mammals and other animals. However, Lyamin et al. claim that in bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca), neonates and their mothers show almost no sleep behaviour for the first month after birth; this...

journal_title：Nature

authors： Sekiguchi Y,Arai K,Kohshima S

更新日期：2006-06-22 00:00:00

abstract：:Phototransduction in invertebrate microvillar photoreceptors is thought to be mediated by the activation of phospholipase C (PLC), but how this leads to gating of the light-sensitive channels is unknown. Most attention has focused on inositol-1,4,5-trisphosphate, a second messenger produced by PLC from phosphatidylino...

journal_title：Nature

authors： Chyb S,Raghu P,Hardie RC

更新日期：1999-01-21 00:00:00

abstract：:The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth's h...

journal_title：Nature

authors： Reinhard CT,Planavsky NJ,Gill BC,Ozaki K,Robbins LJ,Lyons TW,Fischer WW,Wang C,Cole DB,Konhauser KO

更新日期：2017-01-19 00:00:00

abstract：:In the frog Xenopus, the somatic-type 5S ribosomal RNA genes are active in all cells; the oocyte-type 5S genes are active in oocytes but not in somatic cells. A new method of native gel electrophoresis resolves the two types of 5S RNA which are of the same length but different sequence. When somatic nuclei were inject...

journal_title：Nature

authors： Korn LJ,Gurdon JB

更新日期：1981-02-05 00:00:00

abstract：:Apoptosis is a highly regulated process that is crucial for normal development and homeostasis of multicellular organisms. The p35 protein from baculoviruses effectively prevents apoptosis by its broad-spectrum caspase inhibition. Here we report the crystal structure of p35 in complex with human caspase-8 at 3.0 A res...

journal_title：Nature

authors： Xu G,Cirilli M,Huang Y,Rich RL,Myszka DG,Wu H

更新日期：2001-03-22 00:00:00

abstract：:Acyl carrier protein (ACP) transports the growing fatty acid chain between enzymatic domains of fatty acid synthase (FAS) during biosynthesis. Because FAS enzymes operate on ACP-bound acyl groups, ACP must stabilize and transport the growing lipid chain. ACPs have a central role in transporting starting materials and ...

journal_title：Nature

authors： Nguyen C,Haushalter RW,Lee DJ,Markwick PR,Bruegger J,Caldara-Festin G,Finzel K,Jackson DR,Ishikawa F,O'Dowd B,McCammon JA,Opella SJ,Tsai SC,Burkart MD

更新日期：2014-01-16 00:00:00

abstract：:Transmission of obligate bacterial symbionts between generations is vital for the survival of the host. Although the larvae of certain hydrothermal vent tubeworms (Vestimentifera, Siboglinidae) are symbiont-free and possess a transient digestive system, these structures are lost during development, resulting in adult ...

journal_title：Nature

authors： Nussbaumer AD,Fisher CR,Bright M

更新日期：2006-05-18 00:00:00

abstract：:Water has many kinetic and thermodynamic properties that exhibit an anomalous dependence on temperature, in particular in the supercooled phase. These anomalies have long been interpreted in terms of underlying structural causes, and their experimental characterization points to the existence of a singularity at a tem...

journal_title：Nature

authors： Torre R,Bartolini P,Righini R

更新日期：2004-03-18 00:00:00

abstract：:The tumour microenvironment may contribute to tumorigenesis owing to mechanical forces such as fibrotic stiffness or mechanical pressure caused by the expansion of hyper-proliferative cells. Here we explore the contribution of the mechanical pressure exerted by tumour growth onto non-tumorous adjacent epithelium. In t...

journal_title：Nature

authors： Fernández-Sánchez ME,Barbier S,Whitehead J,Béalle G,Michel A,Latorre-Ossa H,Rey C,Fouassier L,Claperon A,Brullé L,Girard E,Servant N,Rio-Frio T,Marie H,Lesieur S,Housset C,Gennisson JL,Tanter M,Ménager C,Fre S,Rob

更新日期：2015-07-02 00:00:00

abstract：:Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation ...

journal_title：Nature

authors： Delledonne M,Xia Y,Dixon RA,Lamb C

更新日期：1998-08-06 00:00:00

abstract：:The nematode Caenorhabditis elegans is an important model for studying the genetics of ageing, with over 50 life-extension mutations known so far. However, little is known about the pathobiology of ageing in this species, limiting attempts to connect genotype with senescent phenotype. Using ultrastructural analysis an...

journal_title：Nature

authors： Herndon LA,Schmeissner PJ,Dudaronek JM,Brown PA,Listner KM,Sakano Y,Paupard MC,Hall DH,Driscoll M

更新日期：2002-10-24 00:00:00

abstract：:Prostaglandins have wide-ranging effects in the body and are thought to be important mediators of inflammation. Cyclooxygenase (COX) plays a key regulatory role in prostaglandin synthesis, and occurs in both constitutive (COX-1) and inducible (COX-2) isoforms. COX-1 is thought to provide cytoprotective effects, wherea...

journal_title：Nature

authors： Dinchuk JE,Car BD,Focht RJ,Johnston JJ,Jaffee BD,Covington MB,Contel NR,Eng VM,Collins RJ,Czerniak PM

更新日期：1995-11-23 00:00:00

abstract：:Oligodendrocytes and astrocytes are macroglial cells of the vertebrate central nervous system. These cells have diverse roles in the maintenance of neurological function. In the embryo, the genetic mechanisms that underlie the specification of macroglial precursors in vivo appear strikingly similar to those that regul...

journal_title：Nature

authors： Rowitch DH,Kriegstein AR

更新日期：2010-11-11 00:00:00

abstract：:The neutron superfluid in most neutron stars should be in a highly turbulent state. If so, this turbulence drastically alters its rotational properties. ...

journal_title：Nature

authors： Greenstein G

更新日期：1970-08-22 00:00:00