Institution
Spanish National Research Council
Government•Madrid, Spain•
About: Spanish National Research Council is a government organization based out in Madrid, Spain. It is known for research contribution in the topics: Population & Galaxy. The organization has 79563 authors who have published 220470 publications receiving 7698991 citations. The organization is also known as: CSIC & Consejo Superior de Investigaciones Científicas.
Topics: Population, Galaxy, Catalysis, Stars, Star formation
Papers published on a yearly basis
Papers
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TL;DR: In several species examined, the fine structure of the peptidoglycan significantly varies with the growth conditions, and the different models for the architecture are discussed with respect to structural and physical parameters.
Abstract: The peptidoglycan (murein) sacculus is a unique and essential structural element in the cell wall of most bacteria. Made of glycan strands cross-linked by short peptides, the sacculus forms a closed, bag-shaped structure surrounding the cytoplasmic membrane. There is a high diversity in the composition and sequence of the peptides in the peptidoglycan from different species. Furthermore, in several species examined, the fine structure of the peptidoglycan significantly varies with the growth conditions. Limited number of biophysical data on the thickness, elasticity and porosity of peptidoglycan are available. The different models for the architecture of peptidoglycan are discussed with respect to structural and physical parameters.
1,876 citations
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TL;DR: A successful alliance between nanoelectronics and nano-optics enables the development of active subwavelength-scale optics and a plethora of nano-optoelectronic devices and functionalities, such as tunable metamaterials, nanoscale optical processing, and strongly enhanced light–matter interactions for quantum devices and biosensing applications.
Abstract: The ability to manipulate optical fields and the energy flow of light is central to modern information and communication technologies, as well as quantum information processing schemes However, because photons do not possess charge, a way of controlling them efficiently by electrical means has so far proved elusive A promising way to achieve electric control of light could be through plasmon polaritons—coupled excitations of photons and charge carriers—in graphene In this two-dimensional sheet of carbon atoms, it is expected that plasmon polaritons and their associated optical fields can readily be tuned electrically by varying the graphene carrier density Although evidence of optical graphene plasmon resonances has recently been obtained spectroscopically, no experiments so far have directly resolved propagating plasmons in real space Here we launch and detect propagating optical plasmons in tapered graphene nanostructures using near-field scattering microscopy with infrared excitation light We provide real-space images of plasmon fields, and find that the extracted plasmon wavelength is very short—more than 40 times smaller than the wavelength of illumination We exploit this strong optical field confinement to turn a graphene nanostructure into a tunable resonant plasmonic cavity with extremely small mode volume The cavity resonance is controlled in situ by gating the graphene, and in particular, complete switching on and off of the plasmon modes is demonstrated, thus paving the way towards graphene-based optical transistors This successful alliance between nanoelectronics and nano-optics enables the development of active subwavelength-scale optics and a plethora of nano-optoelectronic devices and functionalities, such as tunable metamaterials, nanoscale optical processing, and strongly enhanced light–matter interactions for quantum devices and biosensing applications
1,845 citations
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TL;DR: In this article, the authors review the formalism and applications of non-linear perturbation theory (PT) to understand the large-scale structure of the universe, from the linear to the nonlinear regime.
1,833 citations
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University of Portsmouth1, University of Barcelona2, Spanish National Research Council3, Princeton University4, University of Arizona5, Johns Hopkins University6, Fermilab7, University of Chicago8, University of Tokyo9, University of Washington10, University of Sussex11, University of Michigan12, University of Edinburgh13, Los Alamos National Laboratory14, Lawrence Berkeley National Laboratory15, Pennsylvania State University16, Massachusetts Institute of Technology17, Drexel University18, Ohio State University19, Case Western Reserve University20
TL;DR: In this article, an almost independent constraint on the ratio of distances D-V(0.275) = 0.1390 +/- 0.0037 (2.7 per cent accuracy), where r(s) is the comoving sound horizon at the baryon-drag epoch, DV(z) equivalent to [(1 + z)D(A)(2)cz/H(z)](1/3), D-A(z), is the angular diameter distance and H(z).
Abstract: The spectroscopic Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample represents the final set of galaxies observed using the original SDSS target selection criteria. We analyse the clustering of galaxies within this sample, including both the luminous red galaxy and main samples, and also include the 2-degree Field Galaxy Redshift Survey data. In total, this sample comprises 893 319 galaxies over 9100 deg(2). Baryon acoustic oscillations (BAO) are observed in power spectra measured for different slices in redshift; this allows us to constrain the distance-redshift relation at multiple epochs. We achieve a distance measure at redshift z = 0.275, of r(s)(z(d))/D-V(0.275) = 0.1390 +/- 0.0037 (2.7 per cent accuracy), where r(s)(z(d)) is the comoving sound horizon at the baryon-drag epoch, D-V(z) equivalent to [(1 + z)(2)D(A)(2)cz/H(z)](1/3), D-A(z) is the angular diameter distance and H(z) is the Hubble parameter. We find an almost independent constraint on the ratio of distances D-V(0.35)/D-V(0.2) = 1.736 +/- 0.065, which is consistent at the 1.1 sigma level with the best-fitting Lambda cold dark matter model obtained when combining our z = 0.275 distance constraint with the Wilkinson Microwave Anisotropy Probe 5-year (WMAP5) data. The offset is similar to that found in previous analyses of the SDSS DR5 sample, but the discrepancy is now of lower significance, a change caused by a revised error analysis and a change in the methodology adopted, as well as the addition of more data. Using WMAP5 constraints on Omega(b)h(2) and Omega(c) h(2), and combining our BAO distance measurements with those from the Union supernova sample, places a tight constraint on Omega(m) = 0.286 +/- 0.018 and H-0 = 68.2 +/- 2.2 km s(-1) Mpc(-1) that is robust to allowing Omega(k) not equal 0 and omega not equal -1. This result is independent of the behaviour of dark energy at redshifts greater than those probed by the BAO and supernova measurements. Combining these data sets with the full WMAP5 likelihood constraints provides tight constraints on both Omega(k) = -0.006 +/- 0.008 and omega = -0.97 +/- 0.10 for a constant dark energy equation of state.
1,814 citations
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TL;DR: In this article, the kinetic behavior of polyphenols common in fruits as free radical scavengers was studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH).
Abstract: The kinetic behaviour of polyphenols common in fruits as free radical scavengers was studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH.). After addition of different standard concentrations to DPPH. (0.025 g litre-1), the percentage of remaining DPPH. was determined at different times from the absorbances at 515 nm. The percentage remaining DPPH. against reaction time followed a multiplicative model equation: In [DPPH.REM] = b 1n t + 1n a. The slopes of these equations may be useful parameters to define the antioxidant capacity. The steeper the slope, the lower the amount of antioxidant necessary to decrease by 50% the initial DPPH. concentration (EC50). This parameter, EC50, is widely used to measure antioxidant power, but it does not takes into account the reaction time. Time needed to reach the steady state to the concentration corresponding at EC50 (T(EC50)) was calculated, and antiradical efficiency (AE) was proposed as a new parameter to characterise the antioxidant compounds where AE = 1/EC50 T(EC50). It was shown that AE is more discriminatory than EC50. AE values are more useful because they also take into account the reaction time. The results have shown that the order of the AE (x 10(-3)) in the compounds tested was: ascorbic acid (11.44) > caffeic acid (2.75) greater than or equal to gallic acid (2.62) > tannic acid (0.57) greater than or equal to DL-alpha-tocopherol (0.52) > rutin (0.21) greater than or equal to quercetin (0.19) > ferulic acid (0.12) greater than or equal to 3-tert-butyl-4-hydroxyanisole, BHA (0.10) > resveratrol (0.05).
1,812 citations
Authors
Showing all 79686 results
Name | H-index | Papers | Citations |
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Guido Kroemer | 236 | 1404 | 246571 |
George Efstathiou | 187 | 637 | 156228 |
Peidong Yang | 183 | 562 | 144351 |
H. S. Chen | 179 | 2401 | 178529 |
David R. Williams | 178 | 2034 | 138789 |
Andrea Bocci | 172 | 2402 | 176461 |
Adrian L. Harris | 170 | 1084 | 120365 |
Gang Chen | 167 | 3372 | 149819 |
Gregory J. Hannon | 165 | 421 | 140456 |
Alvaro Pascual-Leone | 165 | 969 | 98251 |
Jorge E. Cortes | 163 | 2784 | 124154 |
Dongyuan Zhao | 160 | 872 | 106451 |
John B. Goodenough | 151 | 1064 | 113741 |
David D'Enterria | 150 | 1592 | 116210 |
A. Gomes | 150 | 1862 | 113951 |