Mutations in the bglY gene increase the frequency of spontaneous deletions in Escherichia coli K-12.

abstract：:FRET between the zinc porphyrin (ZnP) chromophore in zinc-substituted cytochrome c (Zn-cyt c) and an Alexa Fluor dye attached to specific surface sites was used to characterize Zn-cyt c unfolding. The use of ZnP as a fluorescent acceptor eliminates the need to doubly label the protein with exogenous dyes to perform FR...

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

authors： Ensign AA,Jo I,Yildirim I,Krauss TD,Bren KL

更新日期：2008-08-05 00:00:00

abstract：:Parkinson's disease (PD) is a neurodegenerative disorder of uncertain pathogenesis characterized by a loss of substantia nigra pars compacta (SNpc) dopaminergic (DA) neurons, and can be modeled by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Both inflammatory processes and oxidative stress may c...

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

authors： Wu DC,Teismann P,Tieu K,Vila M,Jackson-Lewis V,Ischiropoulos H,Przedborski S

更新日期：2003-05-13 00:00:00

abstract：:Microstructural, δ(13)C isotope and C/N ratio investigations were conducted on excavated material from the black Younger Dryas boundary in Lommel, Belgium, aiming for a characterisation of the carbon content and structures. Cubic diamond nanoparticles are found in large numbers. The larger ones with diameters around o...

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

authors： Tian H,Schryvers D,Claeys P

更新日期：2011-01-04 00:00:00

abstract：:A remarkable property of Ca2+ fluxes through the inositol 1,4,5-trisphosphate (InsP3)-gated Ca2+ channel is that successive increments of InsP3 induce repeated transient release of accumulated Ca2+. The initial aim of this study was to propose a model, based on hypotheses compatible with the current description of thi...

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

authors： Swillens S,Combettes L,Champeil P

更新日期：1994-10-11 00:00:00

abstract：:p-Coumaric acid is the precursor of phenylpropanoids, which are plant secondary metabolites that are beneficial to human health. Tyrosine ammonia lyase catalyzes the production of p-coumaric acid from tyrosine. Because of their photosynthetic ability and biosynthetic versatility, cyanobacteria are promising candidates...

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

authors： Xue Y,Zhang Y,Cheng D,Daddy S,He Q

更新日期：2014-07-01 00:00:00

abstract：:Synaptic transmission of the light response from photoreceptors to second-order cells of the retina was studied with the whole-cell patch-clamp technique in tiger salamander (Ambystoma tigrinum) retinal slices. Synaptic strength is modulated by extracellular pH in a striking manner: Light-sensitive postsynaptic curren...

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

authors： Barnes S,Merchant V,Mahmud F

更新日期：1993-11-01 00:00:00

abstract：:Reactive oxygen species (ROS) mediate abscisic acid (ABA) signaling in guard cells. To dissect guard cell ABA-ROS signaling genetically, a cell type-specific functional genomics approach was used to identify 2 MAPK genes, MPK9 and MPK12, which are preferentially and highly expressed in guard cells. To provide genetic ...

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

authors： Jammes F,Song C,Shin D,Munemasa S,Takeda K,Gu D,Cho D,Lee S,Giordo R,Sritubtim S,Leonhardt N,Ellis BE,Murata Y,Kwak JM

更新日期：2009-12-01 00:00:00

abstract：:Previous studies have shown that binding of interleukin 1 (IL-1) to its receptor and intracellular processing of the IL-1/IL-1 receptor complex appear to be different in B- and T-lymphocyte cell lines. In this study we used a B-lymphoid cell line, 70Z/3, and T-lymphoid cell line, EL-4 6.1 C10, to explore further the d...

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

authors： Bomsztyk K,Sims JE,Stanton TH,Slack J,McMahan CJ,Valentine MA,Dower SK

更新日期：1989-10-01 00:00:00

abstract：:The immunoglobulin light chain is thought to be organized into two structural domains, the constant and the variable regions, linked by a switch region of lesser tertiary organization. Light chains of homogeneous rabbit antibodies to pneumococcal polysaccharides labeled with (125)I were subjected to trypsin digestion ...

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

authors： Poulsen K,Fraser KJ,Haber E

更新日期：1972-09-01 00:00:00

abstract：:Are animals conscious? If so, when did consciousness evolve? We address these long-standing and essential questions using a modern neuroscientific approach that draws on diverse fields such as consciousness studies, evolutionary neurobiology, animal psychology, and anesthesiology. We propose that the stepwise emergenc...

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

authors： Mashour GA,Alkire MT

更新日期：2013-06-18 00:00:00

abstract：:From an analysis of the distributions of measures of transmission rates among hosts, we identify an empirical relationship suggesting that, typically, 20% of the host population contributes at least 80% of the net transmission potential, as measured by the basic reproduction number, R0. This is an example of a statist...

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

authors： Woolhouse ME,Dye C,Etard JF,Smith T,Charlwood JD,Garnett GP,Hagan P,Hii JL,Ndhlovu PD,Quinnell RJ,Watts CH,Chandiwana SK,Anderson RM

更新日期：1997-01-07 00:00:00

abstract：:Treatment of quiescent cultures of mouse embryo-derived AKR-2B cells with transforming growth factor beta resulted in an early induction of c-sis mRNA. The increase in c-sis mRNA was followed by a corresponding increase in protein similar to platelet-derived growth factor (PDGF) in the culture medium. In addition, PDG...

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

authors： Leof EB,Proper JA,Goustin AS,Shipley GD,DiCorleto PE,Moses HL

更新日期：1986-04-01 00:00:00

abstract：:In the course of scrapie, a transmissible spongiform encephalopathy caused by an unconventional agent, a normal cellular protein is converted to an abnormal form that copurifies with infectivity and aggregates to form deposits of amyloid. We have used immunocytochemistry and methods that enhance detection of amyloidog...

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

authors： Diedrich JF,Bendheim PE,Kim YS,Carp RI,Haase AT

更新日期：1991-01-15 00:00:00

abstract：:Studies of biotic remains of polar ice caps have been limited to morphological identification of plant pollen and spores. By using sensitive molecular techniques, we now demonstrate a much greater range of detectable organisms; from 2000- and 4000-year-old ice-core samples, we obtained and characterized 120 clones tha...

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

authors： Willerslev E,Hansen AJ,Christensen B,Steffensen JP,Arctander P

更新日期：1999-07-06 00:00:00

abstract：:We show that supercoiling of a DNA trefoil, the simplest knotted ring, perturbs differently the spatial writhe of its two chiral forms. As a consequence, the negative-noded and positive-noded DNA trefoils can be resolved by gel electrophoresis. Analysis of the chirality of trefoils produced by cyclization of two linea...

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

authors： Shaw SY,Wang JC

更新日期：1997-03-04 00:00:00

abstract：:Blue mold of tobacco is caused by the fungus Peronospora tabacina. Its spores are released in the morning when the relative humidity falls, but they require free water for germination. Traditionally, the walls of the shade tents are raised to control the pathogen by drying leaves. We show that raising the walls does n...

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

authors： Aylor DE,Taylor GS

更新日期：1982-01-01 00:00:00

abstract：:The coupling of calcium transport to ATP hydrolysis in rabbit muscle sarcoplasmic reticulum vesicles was determined under steady-state conditions in the presence of 5 mM oxalate and using various concentrations of vesicles to modulate the concentration of free Ca2+ in the medium. This experimental approach takes advan...

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

authors： Gafni A,Boyer PD

更新日期：1985-01-01 00:00:00

abstract：:The crystal structure of the murine Fab S-20-4 from a protective anti-cholera Ab specific for the lipopolysaccharide Ag of the Ogawa serotype has been determined in its unliganded form and in complex with synthetic fragments of the Ogawa O-specific polysaccharide (O-SP). The upstream terminal O-SP monosaccharide is sh...

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

authors： Villeneuve S,Souchon H,Riottot MM,Mazie JC,Lei P,Glaudemans CP,Kovác P,Fournier JM,Alzari PM

更新日期：2000-07-18 00:00:00

abstract：:The temporal distribution of the major extinctions over the past 250 million years has been investigated statistically using various forms of time series analysis. The analyzed record is based on variation in extinction intensity for fossil families of marine vertebrates, invertebrates, and protozoans and contains 12 ...

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

authors： Raup DM,Sepkoski JJ Jr

更新日期：1984-02-01 00:00:00

abstract：:Temporal integration in visual perception is thought to occur within cycles of occipital alpha-band (8-12 Hz) oscillations. Successive stimuli may be integrated when they fall within the same alpha cycle and segregated for different alpha cycles. Consequently, the speed of alpha oscillations correlates with the tempor...

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

authors： Wutz A,Melcher D,Samaha J

更新日期：2018-02-06 00:00:00

abstract：:Linear hierarchies, the classical pecking-order structures, are formed readily in both nature and the laboratory in a great range of species including humans. However, the probability of getting linear structures by chance alone is quite low. In this paper we investigate the two hypotheses that are proposed most often...

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

authors： Chase ID,Tovey C,Spangler-Martin D,Manfredonia M

更新日期：2002-04-16 00:00:00

abstract：:Cell cultures of Catharanthus roseus were supplied with [2-13C, 3-2H]-deoxyxylulose or [2-13C,4-2H]1-deoxyxylulose. Lutein and chlorophylls were isolated from the cell mass, and hydrolysis of the chlorophyll mixtures afforded phytol. Isotope labeling patterns of phytol and lutein were determined by 2H NMR and 1H,2H-de...

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

authors： Arigoni D,Eisenreich W,Latzel C,Sagner S,Radykewicz T,Zenk MH,Bacher A

更新日期：1999-02-16 00:00:00

abstract：:The final step in hydrocarbon biosynthesis involves loss of CO from a fatty aldehyde. This decarbonylation is catalyzed by microsomes from Botyrococcus braunii. Among the several detergents tested for solubilizing the decarbonylase, octyl beta-glucoside (0.1%) was found to be the most effective and released 65% of the...

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

authors： Dennis M,Kolattukudy PE

更新日期：1992-06-15 00:00:00

abstract：:The chromosomal locations of cellular sequences flanking integrated papillomavirus DNA in four cervical carcinoma cell lines and a primary cervical carcinoma have been determined. The two human papillomavirus (HPV) 16 flanking sequences derived from the tumor were localized to chromosome regions 20pter----20q13 and 3p...

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

authors： Dürst M,Croce CM,Gissmann L,Schwarz E,Huebner K

更新日期：1987-02-01 00:00:00

abstract：:Surgical removal of one or both atrial appendages was employed in rats to reduce the intrinsic stores of atriopeptin (AP). In conscious rats (with intact baroreceptor reflexes), bilateral or unilateral atrial appendectomy suppressed the diuresis and natriuresis produced by acute volume expansion. Surprisingly, volume ...

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

authors： Sakata M,Greenwald JE,Needleman P

更新日期：1988-05-01 00:00:00

abstract：:Phagocytic cells are a critical line of defense against infection. The ability of a pathogen to survive and even replicate within phagocytic cells is a potent method of evading the defense mechanisms of the host. A number of pathogens survive within macrophages after phagocytosis and this contributes to their virulenc...

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

authors： Lindgren SW,Stojiljkovic I,Heffron F

更新日期：1996-04-30 00:00:00

abstract：:Prostaglandin (PG) D2 has been shown to be transformed by human 11-ketoreductase to 9 alpha,11 beta-PGF2, a biologically active metabolite that is produced in vivo. During the course of developing a mass spectrometric assay for 9 alpha,11 beta-PGF2, several compounds with characteristics similar to PGF2 were detected ...

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

authors： Wendelborn DF,Seibert K,Roberts LJ 2nd

更新日期：1988-01-01 00:00:00

abstract：:Accumulative aggregation of mutant Huntingtin (Htt) is a primary neuropathological hallmark of Huntington's disease (HD). Currently, mechanistic understanding of the cytotoxicity of mutant Htt aggregates remains limited, and neuroprotective strategies combating mutant Htt-induced neurodegeneration are lacking. Here, w...

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

authors： Zhu Y,Li C,Tao X,Brazill JM,Park J,Diaz-Perez Z,Zhai RG

更新日期：2019-09-17 00:00:00

abstract：:The quantum mechanical problem of the hydrogen atom is treated by use of a finite difference equation in place of Schrödinger's differential equation. The exact solution leads to a wave vector energy expression that is readily converted to the Bohr-Rydberg formula. (The calculations here reported are limited to spheri...

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

authors： Wall FT

更新日期：1986-08-01 00:00:00

abstract：:Rearrangements between tandem sequence homologies of various lengths are a major source of genomic change and can be deleterious to the organism. These rearrangements can result in either deletion or duplication of genetic material flanked by direct sequence repeats. Molecular genetic analysis of repetitive sequence i...

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

authors： Bzymek M,Lovett ST

更新日期：2001-07-17 00:00:00