Abstract：
:Although stars form from clouds of gas and dust, there are insignificant amounts of gas around ordinary (Sun-like) stars. This suggests that hydrogen and helium, the primary constituents of planets such as Jupiter and Saturn, are not easily retained in orbit as a star matures. The gas-giant planets in the Solar System must therefore have formed rapidly. Models of their formation generally suggest that a solid core formed in < or = 10(6) yr, followed by the accretion of the massive gaseous envelope in approximately 10(7) yr (refs 1-5). But how and when the gas of the solar nebula dissipated, and how this compares with the predicted timescale of gas-giant formation, remains unclear, in part because direct observations of circumstellar gas have been made only for stars either younger or older than the critical range of 10(6)-10(7) yr (refs 8-15). Here we report observations of the molecular gas surrounding 20 stars whose ages are likely to be in this range. The gas dissipates rapidly; after a few million years the mass remaining is typically much less than the mass of Jupiter. Thus, if gas-giant planets are common in the Galaxy, they must form even more quickly than present models suggest.
journal_name
Naturejournal_title
Natureauthors
Zuckerman B,Forveille T,Kastner JHdoi
10.1038/373494a0subject
Has Abstractpub_date
1995-02-09 00:00:00pages
494-6issue
6514eissn
0028-0836issn
1476-4687journal_volume
373pub_type
杂志文章相关文献
NATURE文献大全abstract：:Zygotic genome activation (ZGA) is the first transcription event in life1. However, it is unclear how RNA polymerase is engaged in initiating ZGA in mammals. Here, by developing small-scale Tn5-assisted chromatin cleavage with sequencing (Stacc-seq), we investigated the landscapes of RNA polymerase II (Pol II) binding...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-020-2847-y
更新日期：2020-11-01 00:00:00
abstract：:Nuclear pore complexes (NPCs) fuse the inner and outer membranes of the nuclear envelope. They comprise hundreds of nucleoporins (Nups) that assemble into multiple subcomplexes and form large central channels for nucleocytoplasmic exchange1,2. How this architecture facilitates messenger RNA export, NPC biogenesis and ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-020-2670-5
更新日期：2020-10-01 00:00:00
abstract：:Colorectal cancer (CRC) is a heterogeneous disease of the intestinal epithelium that is characterized by the accumulation of mutations and a dysregulated immune response. Up to 90% of disease risk is thought to be due to environmental factors such as diet, which is consistent with a growing body of literature that des...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/s41586-020-2729-3
更新日期：2020-09-01 00:00:00
abstract：:Human leukocyte antigens (HLAs) are highly polymorphic proteins that initiate immunity by presenting pathogen-derived peptides to T cells. HLA polymorphisms mostly map to the antigen-binding cleft, thereby diversifying the repertoire of self-derived and pathogen-derived peptide antigens selected by different HLA allot...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature11147
更新日期：2012-06-28 00:00:00
abstract：:The four R-spondin secreted ligands (RSPO1-RSPO4) act via their cognate LGR4, LGR5 and LGR6 receptors to amplify WNT signalling1-3. Here we report an allelic series of recessive RSPO2 mutations in humans that cause tetra-amelia syndrome, which is characterized by lung aplasia and a total absence of the four limbs. Fun...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-018-0118-y
更新日期：2018-05-01 00:00:00
abstract：:In developing mammalian muscle, axon branches of several motor neurons co-innervate the same muscle fibre. Competition among them results in the strengthening of one and the withdrawal of the rest. It is not known why one particular axon branch survives or why some competitions resolve sooner than others. Here we show...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature01836
更新日期：2003-07-24 00:00:00
abstract：:Many physiological events require transient increases in cytosolic Ca(2+) concentrations. Ryanodine receptors (RyRs) are ion channels that govern the release of Ca(2+) from the endoplasmic and sarcoplasmic reticulum. Mutations in RyRs can lead to severe genetic conditions that affect both cardiac and skeletal muscle, ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature09471
更新日期：2010-11-25 00:00:00
abstract：:In the adult brain, new synapses are formed and pre-existing ones are lost, but the function of this structural plasticity has remained unclear. Learning of new skills is correlated with formation of new synapses. These may directly encode new memories, but they may also have more general roles in memory encoding and ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature09946
更新日期：2011-05-26 00:00:00
abstract：:Long before infants reach, crawl or walk, they explore the world by looking: they look to learn and to engage, giving preferential attention to social stimuli, including faces, face-like stimuli and biological motion. This capacity-social visual engagement-shapes typical infant development from birth and is pathognomo...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature22999
更新日期：2017-07-20 00:00:00
abstract：:In addition to acting as template for protein synthesis, messenger RNA (mRNA) often contains sensory sequence elements that regulate this process. Here we report a new mechanism that limits the number of complete protein molecules that can be synthesized from a single mRNA molecule of the human AMD1 gene encoding aden...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature25174
更新日期：2018-01-18 00:00:00
abstract：:The well known trade-off between hardness and toughness (resistance to fracture) makes simultaneous improvement of both properties challenging, especially in diamond. The hardness of diamond can be increased through nanostructuring strategies1,2, among which the formation of high-density nanoscale twins - crystalline ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-020-2361-2
更新日期：2020-06-01 00:00:00
abstract：:T lymphocytes, essential for the generation of a normal immune response, require the presence of the lymphokine interleukin-2 (IL-2) in order to proliferate. Cells that respond to IL-2 possess a surface receptor glycoprotein specific for this lymphokine. We have recently purified and chemically characterized the IL-2 ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/312768a0
更新日期：1984-12-20 00:00:00
abstract：:Most of what is known about the evolution of deinonychosaurs (that is, the group of theropods most closely related to birds) is based on discoveries from North America and Asia. Except for Unenlagia comahuensis and some fragmentary remains from northern Africa, no other evidence was available on deinonychosaurian dive...
journal_title：Nature
pub_type： 历史文章,杂志文章
doi：10.1038/nature03285
更新日期：2005-02-24 00:00:00
abstract：:At one time the synthetic chemist's last resort, reactions catalysed by transition metals are now the preferred method for synthesizing many types of organic molecule. A recent success in this type of catalysis is the discovery of reactions that form bonds between carbon and heteroatoms (such as nitrogen, oxygen, sulp...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/nature07369
更新日期：2008-09-18 00:00:00
abstract：:The separation of ON and OFF channels and the development of an antagonistic surround occur at the first synapse in the vertebrate retina. This functional differentiation is mediated by the action of the photoreceptor neurotransmitter on the ON bipolar, OFF bipolar and horizontal cells, respectively. Glutamate mimics ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/314096a0
更新日期：1985-03-07 00:00:00
abstract：:Although freeze-fracture electron microscopy is normally analysed with the presumption that particles represent proteins embedded within the membrane, particles which appeared to represent inverted lipid micelles within membranes have been reported. I have now confirmed the occurrence of particles in protein-free lipo...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/287166a0
更新日期：1980-09-11 00:00:00
abstract：:Adult neurogenesis in the dentate gyrus of the hippocampus is highly regulated by environmental influences, and functionally implicated in behavioural responses to stress and antidepressants1-4. However, how adult-born neurons regulate dentate gyrus information processing to protect from stress-induced anxiety-like be...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-018-0262-4
更新日期：2018-07-01 00:00:00
abstract：:The autosomal dominant hyper-IgE syndrome (HIES, 'Job's syndrome') is characterized by recurrent and often severe pulmonary infections, pneumatoceles, eczema, staphylococcal abscesses, mucocutaneous candidiasis, and abnormalities of bone and connective tissue. Mutations presumed to underlie HIES have recently been ide...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature06764
更新日期：2008-04-10 00:00:00
abstract：:The human nose is often considered something of a luxury, but in the rest of the animal world, from bacteria to mammals, detecting chemicals in the environment has been critical to the successful organism. An indication of the importance of olfactory systems is the significant proportion - as much as 4% - of the genom...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/35093026
更新日期：2001-09-13 00:00:00
abstract：:The specification of both the germ line and abdomen in Drosophila depends on the localization of oskar messenger RNA to the posterior of the oocyte. This localization requires several trans-acting factors, including Barentsz and the Mago-Y14 heterodimer, which assemble with oskar mRNA into ribonucleoprotein particles ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature02351
更新日期：2004-02-19 00:00:00
abstract：:Growth of basal cell carcinomas (BCCs) requires high levels of hedgehog (HH) signalling through the transcription factor GLI. Although inhibitors of membrane protein smoothened (SMO) effectively suppress HH signalling, early tumour resistance illustrates the need for additional downstream targets for therapy. Here we ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature11889
更新日期：2013-02-28 00:00:00
abstract：:There is a clear case for drug treatments to be selected according to the characteristics of an individual patient, in order to improve efficacy and reduce the number and severity of adverse drug reactions. However, such personalization of drug treatments requires the ability to predict how different individuals will ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature04648
更新日期：2006-04-20 00:00:00
abstract：:Alternative splicing of eukaryotic messenger RNA precursors is now known to be of widespread importance in generating multiple transcripts from a single gene. This phenomenon has emphasized the problem of the way in which splice sites are selected; recent studies have discussed the role of secondary structure or affin...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/324280a0
更新日期：1986-11-20 00:00:00
abstract：:Most species live in species-rich food webs; yet, for a century, most mathematical models for population dynamics have included only one or two species. We ask whether such models are relevant to the real world. Two-species population models of an interacting consumer and resource collapse to one-species dynamics when...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/417541a
更新日期：2002-05-30 00:00:00
abstract：:There has been much interest in the biochemical and biophysical processes that couple extracellular signals to alterations in gene expression. While many early events associated with the treatment of cells with growth factors have been described (for example, ion flux and protein phosphorylation), it has proved diffic...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/322552a0
更新日期：1986-08-07 00:00:00
abstract：:The nicotinic acetylcholine receptor (AChR) from the electroplax of the ray Torpedo californica is composed of five subunits present in a molar stoichiometry of alpha 2 beta gamma delta (refs 1-3) and contains both the binding site for the neurotransmitter and the cation gating unit (reviewed in refs 4-6). We have rec...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/302528a0
更新日期：1983-04-07 00:00:00
abstract：:The rod and cone transducins are specific G proteins originally thought to be present only in photoreceptor cells of the vertebrate retina. Transducins convert light stimulation of photoreceptor opsins into activation of cyclic GMP phosphodiesterase (reviewed in refs. 5-7). A transducin-like G protein, gustducin, has ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/376080a0
更新日期：1995-07-06 00:00:00
abstract：:Dehydration embrittlement has been proposed to explain both intermediate- and deep-focus earthquakes in subduction zones. Because such earthquakes primarily occur at shallow depths or within the core of the subducting plate, dehydration at relatively low temperatures has been emphasized. However, recent careful reloca...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature02475
更新日期：2004-04-08 00:00:00
abstract：:El Niño events are characterized by surface warming of the tropical Pacific Ocean and weakening of equatorial trade winds that occur every few years. Such conditions are accompanied by changes in atmospheric and oceanic circulation, affecting global climate, marine and terrestrial ecosystems, fisheries and human activ...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/s41586-018-0252-6
更新日期：2018-07-01 00:00:00
abstract：:Interactions of CD4 with the class II major histocompatibility complex (MHC) are crucial during thymic ontogeny and subsequently for helper and cytotoxic functions of CD4+CD8- T lymphocytes. CD4 is the receptor for the T-lymphotropic human immunodeficiency virus and binds its envelope glycoprotein, gp120. The residues...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/339548a0
更新日期：1989-06-15 00:00:00
