Abstract:
:Fully atomistic molecular-dynamics (MD) simulations of perfluoroalkylalkane molecules at the surface of water show the spontaneous formation of aggregates whose size and topography closely resemble the experimentally observed hemimicelles for this system. Furthermore, the grazing incidence X-ray diffraction (GIXD) pattern calculated from the simulation trajectories reproduces the experimental GIXD spectra previously obtained, fully validating the MD simulation results. The detailed analysis of the internal structure of the aggregates obtained by the MD simulations supports a definite rational explanation for the spontaneous formation, stability, size, and shape of perfluoroalkylalkane hemimicelles at the surface of water.
journal_name
Proc Natl Acad Sci U S Aauthors
Silva GMC,Morgado P,Lourenço P,Goldmann M,Filipe EJMdoi
10.1073/pnas.1906782116subject
Has Abstractpub_date
2019-07-23 00:00:00pages
14868-14873issue
30eissn
0027-8424issn
1091-6490pii
1906782116journal_volume
116pub_type
杂志文章abstract::Laser-induced fluorescence at 337-nm excitation was used in vivo to differentiate neoplastic [cervical intraepithelial neoplasia (CIN)], nonneoplastic abnormal (inflammation and human papilloma viral infection), and normal cervical tissues. A colposcope (low-magnification microscope used to view the cervix with reflec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
doi:10.1073/pnas.91.21.10193
更新日期:1994-10-11 00:00:00
abstract::Lizards and snakes putatively arose between the early Jurassic and late Triassic; they diversified worldwide and now occupy many different ecological niches, making them ideal for testing theories on the origin of ecological traits. We propose and test the "deep history hypothesis," which claims that differences in ec...
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.0501104102
更新日期:2005-05-31 00:00:00
abstract::Transgenic (Tg) mouse lines that express chimeric mouse-human prion protein (PrP), designated MHu2M, are susceptible to prions from patients with sporadic Creutzfeldt-Jakob disease (sCJD). With the aim of decreasing the incubation time to fewer than 200 days, we constructed transgenes in which one or more of the nine ...
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.2627989100
更新日期:2003-04-15 00:00:00
abstract::Human IL-10 (hIL-10) modulates critical immune and inflammatory responses by way of interactions with its high- (IL-10R1) and low-affinity (IL-10R2) cell surface receptors. Human cytomegalovirus exploits the IL-10 signaling pathway by expressing a functional viral IL-10 homolog (cmvIL-10), which shares only 27% sequen...
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.152147499
更新日期:2002-07-09 00:00:00
abstract::The multifunctional DNA-binding protein (DBP) encoded by human adenovirus binds RNA. The association of purified DBP with RNA in vitro was demonstrated by using either a gel filtration or a filter binding assay. This association is sensitive to ionic strength and exhibits no apparent sequence specificity. DBP also int...
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.83.23.8947
更新日期:1986-12-01 00:00:00
abstract::Single strands of DNA serve, in rare instances, as promoters for transcription; duplex DNA promoters with individual strands that also have a promoter capacityfunction have not been described. We show that the nontranscribed strand of the Saccharomyces cerevisiae U6 snRNA gene directs transcription initiation factor I...
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.242735699
更新日期:2003-02-04 00:00:00
abstract::A short, highly stereoselective (over 97%) synthesis of all-trans squalene is described. Starting with succinaldehyde, a tetraenedichlorodione having the complete squalene skeleton with the four internal trans olefinic bonds has been developed in four steps involving a sequence of two double Claisen rearrangements. Th...
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.67.3.1465
更新日期:1970-11-01 00:00:00
abstract::To investigate the molecular basis for the tissue-specific expression of the human CD2 gene, its chromatin configuration was assessed by determining DNase I hypersensitivity and the degree of methylation during T-cell lineage commitment and development. Tissue-specific DNase I-hypersensitive sites were found within th...
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.86.11.4195
更新日期:1989-06-01 00:00:00
abstract::The possible role of guanosine 5'-triphosphate,3'-diphosphate (pppGpp) in protein synthesis by Escherichia coli ribosomes and protein factors was examined. Although pppGpp could effectively substitute for GTP in reactions catalyzed by initiation factor 2 (ribosomal binding of fMet-tRNA and formation of N-formylmethion...
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.70.11.3250
更新日期:1973-11-01 00:00:00
abstract::Organ graft rejection is a T-cell-dependent process. The activation of alloreactive T cells requires stimulation of the T-cell receptor/CD3 complex by foreign major histocompatibility complex (MHC)-encoded gene products. However, accumulating evidence suggests that, in addition to T-cell receptor occupancy, other cost...
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.89.22.11102
更新日期:1992-11-15 00:00:00
abstract::The glucose transporter isoform GLUT4 is found only in cells that exhibit insulin-sensitive glucose transport. To investigate the function of this transporter, L6 myoblasts were stably transfected with GLUT4 cDNA. GLUT4 underwent insulin-dependent movement to the cell surface in myoblasts overexpressing the transporte...
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.89.8.3493
更新日期:1992-04-15 00:00:00
abstract::Chlorpromazine (3 x 10(-4)M) prevents the stimulation of adenyl cyclase activity in thyroid membranes produced by thyrotropin and prostaglandin, ACTH stimulation of adenyl cyclase in adrenal tissue, and glucagon- and epinephrine-stimulation of adenyl cyclase activity in liver. Baseline activity is unaffected. Parathyr...
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.65.2.454
更新日期:1970-02-01 00:00:00
abstract::Myosin I, an actin-dependent force-generating enzyme, has been purified from three mammalian sources: bovine adrenal medulla, adrenal cortex, and brain. The purification procedure includes extraction of tissue with ATP at low ionic strength and coprecipitation with actin, followed by gel filtration on Sepharose 4B, an...
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.89.2.490
更新日期:1992-01-15 00:00:00
abstract::In rats fed the liver carcinogen 2-acetylaminofluorene (AAF), the two most abundant types of DNA adduct are N-(deoxyguanosin-8-yl)-2-acetylaminofluorene and its deacetylated derivative. When plasmids carrying AAF adducts replicate in bacteria, the predominant mutations are frameshifts, whereas with deacetylated (AF) a...
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.88.22.10193
更新日期:1991-11-15 00:00:00
abstract::Characterizing the entropy of a system is a crucial, and often computationally costly, step in understanding its thermodynamics. It plays a key role in the study of phase transitions, pattern formation, protein folding, and more. Current methods for entropy estimation suffer from a high computational cost, lack of gen...
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.2017042117
更新日期:2020-12-01 00:00:00
abstract::We present the first experimental evidence to our knowledge that ingroup relations attenuate core disgust and that this helps explain the ability of groups to coact. In study 1, 45 student participants smelled a sweaty t-shirt bearing the logo of another university, with either their student identity (ingroup conditio...
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.1517027113
更新日期:2016-03-08 00:00:00
abstract::In eukaryotes, ubiquitination is an important posttranslational process achieved through a cascade of ubiquitin-activating (E1), conjugating (E2), and ligase (E3) enzymes. Many pathogenic bacteria deliver virulence factors into the host cell that function as E3 ligases. How these bacterial "Trojan horses" integrate in...
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.1115025109
更新日期:2012-02-07 00:00:00
abstract::By harnessing the oxidative power of microorganisms, energy can be recovered from reservoirs of less-concentrated organic matter, such as marine sediment, wastewater, and waste biomass. Left unmanaged, these reservoirs can become eutrophic dead zones and sites of greenhouse gas generation. Here, we introduce a unique ...
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.1307327110
更新日期:2013-10-01 00:00:00
abstract::We compared students' self-reported perception of learning with their actual learning under controlled conditions in large-enrollment introductory college physics courses taught using 1) active instruction (following best practices in the discipline) and 2) passive instruction (lectures by experienced and highly rated...
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.1821936116
更新日期:2019-09-24 00:00:00
abstract::Buffering variability in morphogen distribution is essential for reproducible patterning. A theoretically proposed class of mechanisms, termed "distal pinning," achieves robustness by combining local sensing of morphogen levels with global modulation of gradient spread. Here, we demonstrate a critical role for morphog...
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.1918268117
更新日期:2020-01-21 00:00:00
abstract::TGF-beta-activated kinase-1 (TAK1), also known as MAPKK kinase-7 (MAP3K7), is a candidate effector of multiple circuits in cardiac biology and disease. Here, we show that inhibition of TAK1 in mice by a cardiac-specific dominant-negative mutation evokes electrophysiological and biochemical properties reminiscent of hu...
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.0604708103
更新日期:2006-11-14 00:00:00
abstract::The underpinnings of STAT3 hyperphosphorylation resulting in enhanced signaling and cancer progression are incompletely understood. Loss-of-function mutations of enzymes that dephosphorylate STAT3, such as receptor protein tyrosine phosphatases, which are encoded by the PTPR gene family, represent a plausible mechanis...
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.1319551111
更新日期:2014-01-21 00:00:00
abstract::A primary method for studying cellular function is to examine cell morphology after a given manipulation. Fluorescent markers attached to proteins/intracellular structures of interest in conjunction with 3D fluorescent microscopy are frequently exploited for functional analysis. Despite the central role of morphology ...
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.1117796109
更新日期:2012-05-29 00:00:00
abstract::The activities of cytosolic 3-hydroxy-3-methylglutaryl coenzyme A synthase [3-hydroxy-3-methylglutaryl-CoA acetoacetyl-CoA-lyase (CoA-acylating), EC 4.1.3.5] and microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase[mevalonate:NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34], two sequential enzymes in the chole...
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.74.4.1421
更新日期:1977-04-01 00:00:00
abstract::Although inappropriate activation of the Wnt/beta-catenin pathway has been implicated in the development of hepatocellular carcinoma (HCC), the role of this signaling in liver carcinogenesis remains unclear. To investigate this issue, we constructed a mutant mouse strain, Apc(lox/lox), in which exon 14 of the tumor-su...
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.0404761101
更新日期:2004-12-07 00:00:00
abstract::A determinanat for chloramphenicol resistance, cam, initially detected on a resistance transfer factor (RTF) and since transferred to phage P1, may be acquired from P1 by coliphage lambda. Lambdapcam are obtained when a lambda prophage is induced in bacteria which also harbor P1 cam prophage. Lambdacam formation is no...
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.72.12.5041
更新日期:1975-12-01 00:00:00
abstract::We exploit the unusual genome organization of the ciliate cell to analyze the control of specific gene amplification during a nuclear differentiation process. Ciliates contain two types of nuclei within one cell, the macronucleus and the micronucleus; and after sexual reproduction a new macronucleus is formed from a m...
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.1009284107
更新日期:2010-12-21 00:00:00
abstract::A library of Photobacterium phosphoreum DNA was screened in lambda 2001 for the lumazine protein gene, using two degenerate 17-mer oligonucleotide probes that were deduced from a partial protein primary sequence. The lumazine protein gene was localized to a 3.4-kilobase BamHI/EcoRI fragment in one clone. The fragment ...
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.88.4.1100
更新日期:1991-02-15 00:00:00
abstract::Cell cycle checkpoints appear to contribute to an increase in cell survival and a decrease in abnormal heritable genetic changes following exposure to DNA damaging agents. Though several radiation-sensitive yeast mutants have been identified, little is known about the genes that control these responses in mammalian ce...
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.89.16.7491
更新日期:1992-08-15 00:00:00
abstract::Supernumerary B chromosomes are optional additions to the basic set of A chromosomes, and occur in all eukaryotic groups. They differ from the basic complement in morphology, pairing behavior, and inheritance and are not required for normal growth and development. The current view is that B chromosomes are parasitic e...
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.1204237109
更新日期:2012-08-14 00:00:00