Abstract:
:Discrete growing spiral modes are calculated, on the basis of principles of stellar dynamics, according to the recently developed asymptotic theory of density waves for spiral structure in galaxies. From the growth rates obtained, it appears likely that several spiral modes coexist in a given disk galaxy. General properties of these modes are described for two galaxy models, and some of their important observational implications are discussed.
journal_name
Proc Natl Acad Sci U S Aauthors
Bertin G,Lau YY,Lin CC,Mark JW,Sugiyama Ldoi
10.1073/pnas.74.11.4726subject
Has Abstractpub_date
1977-11-01 00:00:00pages
4726-9issue
11eissn
0027-8424issn
1091-6490journal_volume
74pub_type
杂志文章abstract::The quaternary structure of delta-aminolevulinic acid dehydratase (5-aminolaevulinate hydrolyase, EC 4.2.1.24) from bovine liver was examined by analytical ultracentrifugation, polyacrylamide gel electrophoresis, and electron microscopy. The molecular weights, determined by sedimentation-velocity and sedimentation-equ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.5.1767
更新日期:1974-05-01 00:00:00
abstract::The proteolytic cleavage of sterol regulatory element-binding proteins (SREBPs) is regulated by SREBP cleavage-activating protein (SCAP), which forms complexes with SREBPs in membranes of the endoplasmic reticulum (ER). In sterol-depleted cells, SCAP facilitates cleavage of SREBPs by Site-1 protease, thereby initiatin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.20.11235
更新日期:1999-09-28 00:00:00
abstract::Significant inhibition of spermatogenesis and appearance of antibodies against spermatogenic cells identified by cytotoxicity and immunofluorescence reactions were observed in mice of inbred strains 129/Sv and BALB/c and in albino guinea pigs after syngeneic, allogeneic, and xenogeneic immunization with mouse F9 embry...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.2.459
更新日期:1983-01-01 00:00:00
abstract::We compared whole-exome sequencing (WES) and whole-genome sequencing (WGS) in six unrelated individuals. In the regions targeted by WES capture (81.5% of the consensus coding genome), the mean numbers of single-nucleotide variants (SNVs) and small insertions/deletions (indels) detected per sample were 84,192 and 13,32...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1418631112
更新日期:2015-04-28 00:00:00
abstract::Capsaicin is a unique alkaloid of the plant kingdom restricted to the genus Capsicum. Capsaicin is the pungency factor, a bioactive molecule of food and of medicinal importance. Capsaicin is useful as a counterirritant, antiarthritic, analgesic, antioxidant, and anticancer agent. Capsaicin biosynthesis involves conden...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.0605805103
更新日期:2006-09-05 00:00:00
abstract::The Per-Arnt-Sim (PAS) domain is a ubiquitous protein module with a common three-dimensional fold involved in a wide range of regulatory and sensory functions in all domains of life. The activation of these functions is thought to involve partial unfolding of N- or C-terminal helices attached to the PAS domain. Here w...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0601567103
更新日期:2006-08-01 00:00:00
abstract::The development of Drosophila organ discs can be arrested by culturing them in adult male flies. These aged discs lose some of their differentiation competence and form incomplete imaginal structures. The more advanced the aging, the greater the loss of competence. Discs made to differentiate prematurely show deficien...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.11.4674
更新日期:1975-11-01 00:00:00
abstract::Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin and transferrin. The synthesis of siderophores by Escherichia coli is considered to be fully regulated at the tran...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1007805107
更新日期:2010-08-24 00:00:00
abstract::Epstein-Barr virus (EBV) latent infection membrane protein 1 (LMP1)-induced NF-kappaB activation is important for infected cell survival. LMP1 activates NF-kappaB, in part, by engaging tumor necrosis factor (TNF) receptor-associated factors (TRAFs), which also mediate NF-kappaB activation from LTbetaR and CD40. LTbeta...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2237183100
更新日期:2004-01-06 00:00:00
abstract::The B-cell antigen receptor is composed of membrane immunoglobulin sheathed by an alpha/beta heterodimer. The complex is noncovalently associated with protein kinase activity, and crosslinking of the receptor leads to capping and transmembrane signaling. Here we show that the sheath is not necessary either for this ca...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.2.474
更新日期:1994-01-18 00:00:00
abstract::Saccharomyces cerevisiae cells reproduce by budding to yield a mother cell and a smaller daughter cell. Although both mother and daughter begin G1 simultaneously, the mother cell progresses through G1 more rapidly. Daughter cell G1 delay has long been thought to be due to a requirement for attaining a certain critical...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1833999100
更新日期:2003-09-02 00:00:00
abstract::Parasitic plants share a common anatomical feature, the haustorium. Haustoria enable both infection and nutrient transfer, which often leads to growth penalties for host plants and yield reduction in crop species. Haustoria also reciprocally transfer substances, such as RNA and proteins, from parasite to host, but the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1619078114
更新日期:2017-05-16 00:00:00
abstract::Intermolecular electronic coupling dictates the optical properties of molecular aggregate systems. Of particular interest are photosynthetic pigment-protein complexes that absorb sunlight then efficiently direct energy toward the photosynthetic reaction center. Two-dimensional (2D) ultrafast spectroscopy has been used...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0701201104
更新日期:2007-09-04 00:00:00
abstract::Eccentricity, obliquity, and precession are cyclic parameters of the Earth's orbit whose climatic implications have been widely demonstrated on recent and short time intervals. Amplitude modulations of these parameters on million-year time scales induce "grand orbital cycles," but the behavior and the paleoenvironment...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1419946112
更新日期:2015-10-13 00:00:00
abstract::In contrast with speciation in terrestrial organisms, marine plankton frequently display gradual morphological change without lineage division (e.g., phyletic gradualism or gradual evolution), which has raised the possibility that a different mode of evolution dominates within pelagic environments. Here, we reexamine ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0902887106
更新日期:2009-12-15 00:00:00
abstract::Explanted mouse blastocysts were microinjected in the blastocoel cavity with simian virus 40 (SV40) viral DNA. After surgical transfer to the uteri of pseudopregnant surrogate mothers, approximately 40% of the blastocysts developed to term and became healthy adults without apparent tumors at 1 year of age. Molecular h...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.4.1250
更新日期:1974-04-01 00:00:00
abstract::Serotonin (5-HT) binding sites from bovine and rat cerebral cortex membranes share pharmacological properties that allow both to be subclassified by the same criteria. We show here that [3H]5-HT binding sites from human cortex also possess pharmacological properties that follow the same subclassification scheme as for...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.2.612
更新日期:1985-01-01 00:00:00
abstract::Decision-making accuracy typically increases through collective integration of people's judgments into group decisions, a phenomenon known as the wisdom of crowds. For simple perceptual laboratory tasks, classic signal detection theory specifies the upper limit for collective integration benefits obtained by weighted ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1610732114
更新日期:2017-05-23 00:00:00
abstract::Y chromosomes are different from other chromosomes because of a lack of recombination. Until now, complete sequence information of Y chromosomes has been available only for some primates, although considerable information is available for other organisms, e.g., several species of Drosophila. Here, we report the gene o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0609054104
更新日期:2007-04-10 00:00:00
abstract::In the replication of human immunodeficiency virus type 1 (HIV-1), gag MA (matrix), a major structural protein of the virus, carries out opposing targeting functions. During virus assembly, gag MA is cotranslationally myristoylated, a modification required for membrane targeting of gag polyproteins. During virus infec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.1.367
更新日期:1996-01-09 00:00:00
abstract::Hepatitis E virus is responsible for both sporadic and epidemic hepatitis in developing countries. The nonenveloped virus is 27-34 nm in diameter and has been shown to contain a single-strand, positive-sense, polyadenylylated RNA genome of approximately 7.5 kilobases. The nucleotide sequence of the Burma strain of hep...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.9.3855
更新日期:1992-05-01 00:00:00
abstract::Staphylococcus aureus forms biofilms on indwelling medical devices using a variety of cell-surface proteins. There is growing evidence that specific homophilic interactions between these proteins represent an important mechanism of cell accumulation during biofilm formation, but the underlying molecular mechanisms are...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1616805114
更新日期:2017-04-04 00:00:00
abstract::Sulfur assimilation is an evolutionarily conserved pathway that plays an essential role in cellular and metabolic processes, including sulfation, amino acid biosynthesis, and organismal development. We report that loss of a key enzymatic component of the pathway, bisphosphate 3'-nucleotidase (Bpnt1), in mice, both who...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1715302115
更新日期:2018-03-20 00:00:00
abstract::More than a thousand proteins are thought to contribute to mammalian chromatin and its regulation, but our understanding of the genomic occupancy and function of most of these proteins is limited. Here we describe an approach, which we call "chromatin proteomic profiling," to identify proteins associated with genomic ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1502971112
更新日期:2015-03-24 00:00:00
abstract::We have recently demonstrated that immunization with hepatitis C virus-like particles (HCV-LPs) generated in insect cells can elicit both humoral and cellular immune responses in BALB/c mice. Here, we evaluate the immunogenicity of HCV-LPs in HLA2.1 transgenic (AAD) mice in comparison to DNA immunization. HCV-LP immun...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1131929100
更新日期:2003-05-27 00:00:00
abstract::The enterotoxigenic Escherichia coli (ETEC) are among the most common causes of diarrheal illness and death due to diarrhea among young children in low-/middle-income countries (LMICs). ETEC have also been associated with important sequelae including malnutrition and stunting, placing children at further risk of death...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2012480117
更新日期:2020-11-17 00:00:00
abstract::In genotypic mutation analysis DNA sequence changes are determined without the in vivo or in vitro selection of phenotypically altered cells. We have studied the induction of base-pair changes by N-ethyl-N-nitrosourea in Taq I endonuclease recognition site 2508-2511 (TCGA) of the c-H-ras1 gene in human fibroblasts by ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.12.5331
更新日期:1992-06-15 00:00:00
abstract::Murine and human cDNAs, related to but distinct from c-raf-1, have been isolated and designated mA-raf and hA-raf, respectively. The mA-raf and hA-raf cDNAs detect the same murine and human fragments in Southern blots of restriction enzyme-cleaved murine and human cellular DNA. The murine restriction enzyme fragments ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.11.3934
更新日期:1986-06-01 00:00:00
abstract::Toll-like receptor 4 (TLR4), the principal signaling receptor for lipopolysaccharide (LPS) in mammals, requires the binding of MD-2 to its extracellular domain for maximal responsiveness. MD-2 contains a leader sequence but lacks a transmembrane domain, and we asked whether it is secreted into the medium as an active ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.211445098
更新日期:2001-10-09 00:00:00
abstract::The failure of the population of microjunctions forming the frictional interface between two solids is central to fields ranging from biomechanics to seismology. This failure is mediated by the propagation along the interface of various types of rupture fronts, covering a wide range of velocities. Among them are the s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1321752111
更新日期:2014-06-17 00:00:00