TY  - JOUR
A1  - Zbilut, J. P.
A1  - Mitchell, J. C.
A1  - Giuliani, A.
A1  - Colosimo, A.
A1  - Marwan, Norbert
A1  - Webber, C. L.
T1  - Singular hydrophobicity patterns and net charge : a mesoscopic principle for protein aggregation/folding
N2  - A statistical model describing the propensity for protein aggregation is presented. Only amino-acid hydrophobicity values and calculated net charge are used for the model. The combined effects of hydrophobic patterns as computed by the signal analysis technique, recurrence quantification, plus calculated net charge were included in a function emphasizing the effect of singular hydrophobic patches which were found to be statistically significant for predicting aggregation propensity as quantified by fluorescence studies obtained from the literature. These results suggest preliminary evidence for a mesoscopic principle for protein folding/aggregation. (C) 2004 Elsevier B.V. All rights reserved
Y1  - 2004
SN  - 0378-4371
ER  - 
TY  - JOUR
A1  - Zaritsky, Dennis
A1  - Courtois, Helene
A1  - Munoz-Mateos, Juan-Carlos
A1  - Sorce, Jenny
A1  - Erroz-Ferrer, S.
A1  - Comeron, S.
A1  - Gadotti, D. A.
A1  - Gil De Paz, A.
A1  - Hinz, J. L.
A1  - Laurikainen, E.
A1  - Kim, T.
A1  - Laine, J.
A1  - Menendez-Delmestre, K.
A1  - Mizusawa, T.
A1  - Regan, M. W.
A1  - Salo, H.
A1  - Seibert, M.
A1  - Sheth, K.
A1  - Athanassoula, E.
A1  - Bosma, A.
A1  - Cisternas, M.
A1  - Ho, Luis C.
A1  - Holwerda, B.
T1  - The baryonic Tully-Fisher relationship for S(4)G galaxies and the  "condensed" baryon fraction of galaxies
JF  - The astronomical journal
N2  - We combine data from the Spitzer Survey for Stellar Structure in Galaxies, a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of Hi spectral line profiles to examine the baryonic Tully-Fisher (BTF) relation. We find (1) that the BTF has lower scatter than the classic Tully-Fisher (TF) relation and is better described as a linear relationship, confirming similar previous results, (2) that the inclusion of a radial scale in the BTF decreases the scatter but only modestly, as seen previously for the TF relation, and (3) that the slope of the BTF, which we find to be 3.5 +/- 0.2 (Delta log M-baryon/Delta log v(c)), implies that on average a nearly constant fraction (similar to 0.4) of all baryons expected to be in a halo are "condensed" onto the central region of rotationally supported galaxies. The condensed baryon fraction, M-baryon/M-total, is, to our measurement precision, nearly independent of galaxy circular velocity (our sample spans circular velocities, vc, between 60 and 250 km s(-1), but is extended to v(c) similar to 10 km s(-1) using data from the literature). The observed galaxy-to-galaxy scatter in this fraction is generally <= a factor of 2 despite fairly liberal selection criteria. These results imply that cooling and heating processes, such as cold versus hot accretion, mass loss due to stellar winds, and active galactic nucleus driven feedback, to the degree that they affect the global galactic properties involved in the BTF, are independent of halo mass for galaxies with 10 < v(c) < 250 km s(-1) and typically introduce no more than a factor of two range in the resulting M-baryon/M-total. Recent simulations by Aumer et al. of a small sample of disk galaxies are in excellent agreement with our data, suggesting that current simulations are capable of reproducing the global properties of individual disk galaxies. More detailed comparison to models using the BTF holds great promise, but awaits improved determinations of the stellar masses.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - galaxies: fundamental parameters
KW  - galaxies: stellar content
KW  - galaxies: structure
Y1  - 2014
U6  - https://doi.org/10.1088/0004-6256/147/6/134
SN  - 0004-6256
SN  - 1538-3881
VL  - 147
IS  - 6
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Zaragoza-Cardiel, Javier
A1  - Gómez-González, Víctor Mauricio Alfonso
A1  - Mayya, Yalia Divakara
A1  - Ramos-Larios, Gerardo
T1  - Nebular abundance gradient in the Cartwheel galaxy using MUSE data
JF  - Monthly notices of the Royal Astronomical Society
N2  - We here present the results from a detailed analysis of nebular abundances of commonly observed ions in the collisional ring galaxy Cartwheel using the Very Large Telescope (VLT) Multi-Unit Spectroscopic Explorer (MUSE) data set. The analysis includes 221 H II regions in the star-forming ring, in addition to 40 relatively fainter H a-emitting regions in the spokes, disc, and the inner ring. The ionic abundances of He, N, O, and Fe are obtained using the direct method (DM) for 9, 20, 20, and 17 ring H II regions, respectively, where the S++ temperature-sensitive line is detected. For the rest of the regions, including all the nebulae between the inner and the outer ring, we obtained O abundances using the strong-line method (SLM). The ring regions have a median 12 + log O/H = 8.19 +/- 0.15, log N/O = -1.57 +/- 0.09 and log Fe/O = -2.24 +/- 0.09 using the DM. Within the range of O abundances seen in the Cartwheel, the N/O and Fe/O values decrease proportionately with increasing O, suggesting local enrichment of O without corresponding enrichment of primary N and Fe. The O abundances of the disc H II regions obtained using the SLM show a well-defined radial gradient. The mean O abundance of the ring H II regions is lower by similar to 0.1 dex as compared to the extrapolation of the radial gradient. The observed trends suggest the preservation of the pre-collisional abundance gradient, displacement of most of the processed elements to the ring, as predicted by the recent simulation by Renaud et al., and post-collisional infall of metal-poor gas in the ring.
KW  - galaxies: star clusters
KW  - galaxies: individual
KW  - galaxies: abundances
Y1  - 2022
U6  - https://doi.org/10.1093/mnras/stac1423
SN  - 0035-8711
SN  - 1365-2966
VL  - 514
IS  - 2
SP  - 1689
EP  - 1705
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zapata-Arteaga, Osnat
A1  - Marina, Sara
A1  - Zuo, Guangzheng
A1  - Xu, Kai
A1  - Dörling, Bernhard
A1  - Alberto Pérez, Luis
A1  - Sebastián Reparaz, Juan
A1  - Martín, Jaime
A1  - Kemerink, Martijn
A1  - Campoy-Quiles, Mariano
T1  - Design rules for polymer blends with high thermoelectric performance
JF  - Advanced energy materials
N2  - A combinatorial study of the effect of in-mixing of various guests on the thermoelectric properties of the host workhorse polymer poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT) is presented. Specifically, the composition and thickness for doped films of PBTTT blended with different polymers are varied. Some blends at guest weight fractions around 10-15% exhibit up to a fivefold increase in power factor compared to the reference material, leading to zT values around 0.1. Spectroscopic analysis of the charge-transfer species, structural characterization using grazing-incidence wide-angle X-ray scattering, differential scanning calorimetry, Raman, and atomic force microscopy, and Monte Carlo simulations are employed to determine that the key to improved performance is for the guest to promote long-range electrical connectivity and low disorder, together with similar highest occupied molecular orbital levels for both materials in order to ensure electronic connectivity are combined.
KW  - doping
KW  - microstructure
KW  - organic thermoelectrics
KW  - orientation
KW  - ternary
Y1  - 2022
U6  - https://doi.org/10.1002/aenm.202104076
SN  - 1614-6832
SN  - 1614-6840
VL  - 12
IS  - 19
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Zamponi, Flavio
A1  - Penfold, Thomas J.
A1  - Nachtegaal, Maarten
A1  - Luebcke, Andrea
A1  - Rittmann, Jochen
A1  - Milne, Chris J.
A1  - Chergui, Majed
A1  - van Bokhoven, Jeroen A.
T1  - Probing the dynamics of plasmon-excited hexanethiol-capped gold nanoparticles by picosecond X-ray absorption spectroscopy
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - Picosecond X-ray absorption spectroscopy (XAS) is used to investigate the electronic and structural dynamics initiated by plasmon excitation of 1.8 nm diameter Au nanoparticles (NPs) functionalised with 1-hexanethiol. We show that 100 ps after photoexcitation the transient XAS spectrum is consistent with an 8% expansion of the Au-Au bond length and a large increase in disorder associated with melting of the NPs. Recovery of the ground state occurs with a time constant of similar to 1.8 ns, arising from thermalisation with the environment. Simulations reveal that the transient spectrum exhibits no signature of charge separation at 100 ps and allows us to estimate an upper limit for the quantum yield (QY) of this process to be <0.1.
Y1  - 2014
U6  - https://doi.org/10.1039/c4cp03301a
SN  - 1463-9076
SN  - 1463-9084
VL  - 16
IS  - 42
SP  - 23157
EP  - 23163
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Zamponi, Flavio
A1  - Ansari, Zunaira
A1  - von Korff Schmising, Clemens
A1  - Rothhardt, Philip
A1  - Zhavoronkov, Nickolai
A1  - Woerner, Michael
A1  - Elsaesser, Thomas
A1  - Bargheer, Matias
A1  - Trobitzsch-Ryll, Timo
A1  - Haschke, Michael
T1  - Femtosecond hard X-ray plasma sources with a kilohertz repetition rate
N2  - Laser-driven plasma sources of femtosecond hard X-ray pulses have found widespread application in ultrafast X- ray diffraction. The recent development of plasma sources working at kilohertz repetition rates has allowed for diffraction experiments with strongly improved sensitivity, now revealing subtle fully reversible changes of the geometry of crystal lattices. We provide a brief review of this development and present a novel plasma source with an optimized mechanical and optical design, providing a high flux of several 10(10) photons/s at the Cu-K alpha energy of 8.04 keV and a pulse duration of a parts per thousand currency sign300 fs. First experiments, including the generation of Debye-Scherrer diffraction patterns from Si powder, demonstrate the high performance of this source.
Y1  - 2009
UR  - http://www.springerlink.com/content/100501
U6  - https://doi.org/10.1007/s00339-009-5171-9
SN  - 0947-8396
ER  - 
TY  - JOUR
A1  - Zalden, Peter
A1  - Quirin, Florian
A1  - Schumacher, Mathias
A1  - Siegel, Jan
A1  - Wei, Shuai
A1  - Koc, Azize
A1  - Nicoul, Matthieu
A1  - Trigo, Mariano
A1  - Andreasson, Pererik
A1  - Enquist, Henrik
A1  - Shu, Michael J.
A1  - Pardini, Tommaso
A1  - Chollet, Matthieu
A1  - Zhu, Diling
A1  - Lemke, Henrik
A1  - Ronneberger, Ider
A1  - Larsson, Jörgen
A1  - Lindenberg, Aaron M.
A1  - Fischer, Henry E.
A1  - Hau-Riege, Stefan
A1  - Reis, David A.
A1  - Mazzarello, Riccardo
A1  - Wuttig, Matthias
A1  - Sokolowski-Tinten, Klaus
T1  - Femtosecond x-ray diffraction reveals a liquid-liquid phase transition in phase-change materials
JF  - Science
N2  - In phase-change memory devices, a material is cycled between glassy and crystalline states. The highly temperature-dependent kinetics of its crystallization process enables application in memory technology, but the transition has not been resolved on an atomic scale. Using femtosecond x-ray diffraction and ab initio computer simulations, we determined the time-dependent pair-correlation function of phase-change materials throughout the melt-quenching and crystallization process. We found a liquid-liquid phase transition in the phase-change materials Ag4In3Sb67Te26 and Ge15Sb85 at 660 and 610 kelvin, respectively. The transition is predominantly caused by the onset of Peierls distortions, the amplitude of which correlates with an increase of the apparent activation energy of diffusivity. This reveals a relationship between atomic structure and kinetics, enabling a systematic optimization of the memory-switching kinetics.
Y1  - 2019
U6  - https://doi.org/10.1126/science.aaw1773
SN  - 0036-8075
SN  - 1095-9203
VL  - 364
IS  - 6445
SP  - 1062
EP  - 1067
PB  - American Assoc. for the Advancement of Science
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Zaks, Michael
A1  - Pikovskij, Arkadij
T1  - Chimeras and complex cluster states in arrays of spin-torque oscillators
JF  - Scientific reports
N2  - We consider synchronization properties of arrays of spin-torque nano-oscillators coupled via an RC load. We show that while the fully synchronized state of identical oscillators may be locally stable in some parameter range, this synchrony is not globally attracting. Instead, regimes of different levels of compositional complexity are observed. These include chimera states (a part of the array forms a cluster while other units are desynchronized), clustered chimeras (several clusters plus desynchronized oscillators), cluster state (all oscillators form several clusters), and partial synchronization (no clusters but a nonvanishing mean field). Dynamically, these states are also complex, demonstrating irregular and close to quasiperiodic modulation. Remarkably, when heterogeneity of spin-torque oscillators is taken into account, dynamical complexity even increases: close to the onset of a macroscopic mean field, the dynamics of this field is rather irregular.
Y1  - 2017
U6  - https://doi.org/10.1038/s41598-017-04918-9
SN  - 2045-2322
VL  - 7
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Tomov, Petar
T1  - Onset of time dependence in ensembles of excitable elements with global repulsive coupling
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - We consider the effect of global repulsive coupling on an ensemble of identical excitable elements. An increase of the coupling strength destabilizes the synchronous equilibrium and replaces it with many attracting oscillatory states, created in the transcritical heteroclinic bifurcation. The period of oscillations is inversely proportional to the distance from the critical parameter value. If the elements interact with the global field via the first Fourier harmonics of their phases, the stable equilibrium is in one step replaced by the attracting continuum of periodic motions.
Y1  - 2016
U6  - https://doi.org/10.1103/PhysRevE.93.020201
SN  - 2470-0045
SN  - 2470-0053
VL  - 93
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Osipov, Grigory V.
A1  - Kurths, Jürgen
T1  - Phase synchronization of chaotic oscillations in terms of periodic orbits
Y1  - 1997
SN  - 1054-1500
ER  -