| 51. |
- Adam, J., et al.
(author)
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Rapidity and transverse-momentum dependence of the inclusive J/psi nuclear modification factor in p-Pb collisions at root s(NN)=5.02 TeV
- 2015
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In: Journal of High Energy Physics. - 1029-8479. ; :6
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Journal article (peer-reviewed)abstract
- We have studied the transverse-momentum (p(T)) dependence of the inclusive J/psi production in p-Pb collisions at root s(NN) = 5.02 TeV, in three center-of-mass rapidity (y(cms)) regions, down to zero p(T). Results in the forward and backward rapidity ranges (2.03 < y(cms) < 3.53 and -4.46 < y(cms) < -2.96) are obtained by studying the J/psi decay to mu(+)mu(-), while the mid-rapidity region (-1.37 < y(cms) < 0.43) is investigated by measuring the e(+)e(-) decay channel. The p(T) dependence of the J/psi production cross section and nuclear modification factor are presented for each of the rapidity intervals, as well as the J/psi mean p(T) values. Forward and mid-rapidity results show a suppression of the J/psi yield, with respect to pp collisions, which decreases with increasing p(T). At backward rapidity no significant J/psi suppression is observed. Theoretical models including a combination of cold nuclear matter effects such as shadowing and partonic energy loss, are in fair agreement with the data, except at forward rapidity and low transverse momentum. The implications of the p-Pb results for the evaluation of cold nuclear matter effects on J/psi production in Pb-Pb collisions are also discussed.
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| 52. |
- Adam, J., et al.
(author)
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Search for weakly decaying (Lambda n)over-bar and Lambda Lambda exotic bound states in central Pb-Pb collisions at root S-NN=2.76 TeV
- 2016
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In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 752, s. 267-277
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Journal article (peer-reviewed)abstract
- We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible (Lambda n) over bar bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at root S-NN = 2.76 TeV, by invariant mass analysis in the decay modes (Lambda n) over bar (d) over bar pi(+) and H-dibaryon -> Lambda p pi(-). No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.
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| 53. |
- Adam, J., et al.
(author)
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Two-pion femtoscopy in p-Pb collisions at root(NN)-N-S=5.02 TeV
- 2015
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 91:3
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Journal article (peer-reviewed)abstract
- We report the results of the femtoscopic analysis of pairs of identical pions measured in p-Pb collisions at root(NN)-N-S = 5.02 TeV. Femtoscopic radii are determined as a function of event multiplicity and pair momentum in three spatial dimensions. As in the pp collision system, the analysis is complicated by the presence of sizable background correlation structures in addition to the femtoscopic signal. The radii increase with event multiplicity and decrease with pair transverse momentum. When taken at comparable multiplicity, the radii measured in p-Pb collisions, at high multiplicity and low pair transverse momentum, are 10%-20% higher than those observed in pp collisions but below those observed in A-A collisions. The results are compared to hydrodynamic predictions at large event multiplicity as well as discussed in the context of calculations based on gluon saturation.
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| 54. |
- Arcavi, Iair, et al.
(author)
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Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star
- 2017
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 551:7679, s. 210-213
-
Journal article (peer-reviewed)abstract
- Every supernova so far observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decreasing in velocity over time, as the ejecta expand and thin, revealing slower-moving material that was previously hidden. In addition, every supernova that exhibits the absorption lines of hydrogen has one main light-curve peak, or a plateau in luminosity, lasting approximately 100 days before declining(1). Here we report observations of iPTF14hls, an event that has spectra identical to a hydrogen-rich core-collapse supernova, but characteristics that differ extensively from those of known supernovae. The light curve has at least five peaks and remains bright for more than 600 days; the absorption lines show little to no decrease in velocity; and the radius of the line-forming region is more than an order of magnitude bigger than the radius of the photosphere derived from the continuum emission. These characteristics are consistent with a shell of several tens of solar masses ejected by the progenitor star at supernova-level energies a few hundred days before a terminal explosion. Another possible eruption was recorded at the same position in 1954. Multiple energetic pre-supernova eruptions are expected to occur in stars of 95 to 130 solar masses, which experience the pulsational pair instability(2-5). That model, however, does not account for the continued presence of hydrogen, or the energetics observed here. Another mechanism for the violent ejection of mass in massive stars may be required.
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| 55. |
- Blanton, Michael R., et al.
(author)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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In: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Journal article (peer-reviewed)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 56. |
- Botvinik-Nezer, Rotem, et al.
(author)
-
Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
-
Journal article (peer-reviewed)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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| 57. |
- Cao, Zhi, et al.
(author)
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Adherence to a healthy lifestyle counteracts the negative effects of risk factors on all-cause mortality in the oldest-old
- 2019
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In: Aging. - : Impact Journals, LLC. - 1945-4589 .- 1945-4589. ; 11:18, s. 7605-7619
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Journal article (peer-reviewed)abstract
- In the study, we examined the extent to which the harmful effects of risk factors on all-cause mortality can be counteracted by healthy lifestyle practices in the oldest-old (80 years of age and older). A total of 17,660 oldest-old from China were followed up for up to 10 years. The data were analyzed using the Cox proportional hazard model with adjustment for potential confounders. We found that having a rural residence, not being married, having lower economic status, physical disability, impaired cognitive function, or comorbidity were all associated with an elevated risk of mortality. Using these factors, we computed a weighted risk score. Because never smoking, never drinking, doing physical exercise, having an ideal diet, and a normal weight were independently associated with lower mortality, we also combined them to compute a weighted protection score. Both scores were divided into lowest, middle, and highest groups using their tertiles. In joint effect analyses, participants with the combined highest-risk score and lowest-protection score profile had a nearly threefold higher joint death risk. These analyses show that adherence to a healthy lifestyle counteracts the negative effect of risk factors on all-cause mortality in the oldest-old by more than 20%.
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| 58. |
- Chen, Haiyang, et al.
(author)
-
A guest-assisted molecular-organization approach for >17% efficiency organic solar cells using environmentally friendly solvents
- 2021
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In: Nature Energy. - : NATURE PORTFOLIO. - 2058-7546. ; 6:11, s. 1045-1053
-
Journal article (peer-reviewed)abstract
- The power conversion efficiencies (PCEs) of laboratory-sized organic solar cells (OSCs), usually processed from low-boiling-point and toxic solvents, have reached high values of over 18%. However, there is usually a notable drop of the PCEs when green solvents are used, limiting practical development of OSCs. Herein, we obtain certificated PCEs over 17% in OSCs processed from a green solvent paraxylene (PX) by a guest-assisted assembly strategy, where a third component (guest) is employed to manipulate the molecular interaction of the binary blend. In addition, the high-boiling-point green solvent PX also enables us to deposit a uniform large-area module (36 cm(2)) with a high efficiency of over 14%. The strong molecular interaction between the host and guest molecules also enhances the operational stability of the devices. Our guest-assisted assembly strategy provides a unique approach to develop large-area and high-efficiency OSCs processed from green solvents, paving the way for industrial development of OSCs. Organic solar cells processed from green solvents are easier to implement in manufacturing yet their efficiency is low. Chen et al. devise a guest molecule to improve the molecular packing, enabling devices with over 17% efficiency.
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| 59. |
- Chen, Haiyang, et al.
(author)
-
Heterogeneous Nucleating Agent for High-Boiling-Point Nonhalogenated Solvent-Processed Organic Solar Cells and Modules
- 2024
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In: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Journal article (peer-reviewed)abstract
- High-boiling-point nonhalogenated solvents are superior solvents to produce large-area organic solar cells (OSCs) in industry because of their wide processing window and low toxicity; while, these solvents with slow evaporation kinetics will lead excessive aggregation of state-of-the-art small molecule acceptors (e.g. L8-BO), delivering serious efficiency losses. Here, a heterogeneous nucleating agent strategy is developed by grafting oligo (ethylene glycol) side-chains on L8-BO (BTO-BO). The formation energy of the obtained BTO-BO; while, changing from liquid in a solvent to a crystalline phase, is lower than that of L8-BO irrespective of the solvent type. When BTO-BO is added as the third component into the active layer (e.g. PM6:L8-BO), it easily assembles to form numerous seed crystals, which serve as nucleation sites to trigger heterogeneous nucleation and increase nucleation density of L8-BO through strong hydrogen bonding interactions even in high-boiling-point nonhalogenated solvents. Therefore, it can effectively suppress excessive aggregation during growth, achieving ideal phase-separation active layer with small domain sizes and high crystallinity. The resultant toluene-processed OSCs exhibit a record power conversion efficiency (PCE) of 19.42% (certificated 19.12%) with excellent operational stability. The strategy also has superior advantages in large-scale devices, showing a 15.03-cm2 module with a record PCE of 16.35% (certificated 15.97%). The heterogeneous nucleating agent (BTO-BO) is developed to suppress the excessive aggregation of L8-BO in high-boiling-point nonhalogenated solvents processing, achieving the active layer with high crystallinity and nano-scaled phase separation morphology. The resultant OSCs achieve record power conversion efficiencies of 19.42% (0.062-cm2) and 16.35% (15. 03-cm2) with excellent operational stabilities. image
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| 60. |
- Chen, Mengying, et al.
(author)
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A prospective study of pain experience in a neonatal intensive care unit of China
- 2012
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In: The Clinical Journal of Pain. - Philadelphia, PA, USA : Lippingcott Williams & Wilkins. - 0749-8047 .- 1536-5409. ; 28:8, s. 700-704
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Journal article (peer-reviewed)abstract
- Objectives: To assess pain burden in neonates during their hospitalization in China and thus provide evidence for the necessity of neonatal pain management. Patients and Methods: The Neonatal Facial Coding System was used to evaluate pain in neonates. We prospectively collected data of all painful procedures performed on 108 neonates (term, 62; preterm, 46) recruited from admission to discharge in a neonatal intensive care unit of a university-affiliated hospital in China. Results: We found that during hospitalization each preterm and term neonate was exposed to a median of 100.0 (range, 11 to 544) and 56.5 (range, 12 to 249) painful procedures, respectively. Most of the painful procedures were performed within the first 3 days. Preterm neonates, especially those born at 28 and 29 weeks' gestational age, experienced more pain than those born at 30 weeks' gestation or later (P < 0.001). Among those painful procedures, tracheal aspiration was the most frequently performed on preterm neonates, and intravenous cannulation was the most common for term neonates. Moreover, tracheal intubations and femoral venous puncture were found to be the most painful. Notably, none of the painful procedures was accompanied by analgesia. Conclusions: Neonates, particularly preterm neonates, were exposed to numerous invasive painful procedures without appropriate analgesia in hospitals in China. The potential long-term impacts of poorly treated pain in neonates call for a change in pediatric practice in China and in countries with similar practices.
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