Abstract Previous data demonstrate that traumatic brain injury (TBI) activates autophagy, and increases microtubule-associated protein 1 light chain 3 (LC3) immunostaining mainly in neurons. However, ...the role of autophagy in traumatic brain damage remains elusive. The aim of the present study was to investigate the autophagic mechanisms participating in traumatic brain injury. The autophagy inhibitors 3-methyladenine (3-MA) and bafliomycin A1 (BFA) were administered with a single i.c.v. injection before TBI. We first examined the protein levels of Beclin-1 and LC3 II, which have been found to promote autophagy previously. Immunoblotting analysis showed that 3-MA pretreatment reduced post-TBI Beclin-1 and LC3-II levels, and maintained p62/SQSTM1 (p62) levels. In addition, double immunolabeling showed that the increased punctate LC3-II dots colocalizing with Propidium Iodide (PI)-stained nuclei at 24 h after injury, were partially inhibited by 3-MA pretreatment. Furthermore, inhibition of autophagy could reduce TBI-induced cell injury assessed with i.p. injection of PI and lesion volume, and attenuate behavioral outcome evaluated by motor test and Morris water maze. The neuroprotective effects were associated with an inhibition on TBI-induced up-regulation of LC3, Beclin-1, cathepsin B, caspase-3 and the Beclin-1/Bcl-2 ratio. Taken together, these data imply that the autophagy pathway is involved in the pathophysiologic responses after TBI, and inhibition of this pathway may help attenuate traumatic damage and functional outcome deficits.
The interface between transition metal compounds provides a rich playground for emergent phenomena. Recently, significantly enhanced superconductivity has been reported for single-layer FeSe on ...Nb-doped SrTiO3 substrate. Yet it remains mysterious how the interface affects the superconductivity. Here we use in situ angle-resolved photoemission spectroscopy to investigate various FeSe-based heterostructures grown by molecular beam epitaxy, and uncover that electronic correlations and superconducting gap-closing temperature (Tg) are tuned by interfacial effects. Tg up to 75 K is observed in extremely tensile-strained single-layer FeSe on Nb-doped BaTiO3, which sets a record high pairing temperature for both Fe-based superconductor and monolayer-thick films, providing a promising prospect on realizing more cost-effective superconducting device. Moreover, our results exclude the direct correlation between superconductivity and tensile strain or the energy of an interfacial phonon mode, and highlight the critical and non-trivial role of FeSe/oxide interface on the high Tg, which provides new clues for understanding its origin.
SnO2 attracts considerable interest as a promising high-capacity anode material for lithium ion batteries. It is believed that SnO2 stores lithium by the alloying and de-alloying reactions after the ...initial irreversible reduction from SnO2 to Li2O and metallic Sn. Here we report that a reversible conversion reaction, similar to that often observed in transition metal oxides, can occur in the cycling of the carbon-coated SnO2 hollow microspheres (SnO2/C), as is evidenced by Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM) and theoretical calculations. However, only alloying and de-alloying reactions can reversibly take place in carbon-free SnO2 hollow microspheres. The reversible capacity of the SnO2/C is even higher than the theoretical capacity of the free SnO2. These findings provide guidance to designing anode materials with higher reversible capacities.
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► The SnO2 and carbon-coated SnO2 (SnO2/C) hollow microspheres are fabricated by hydrothermal reactions respectively. ► The SnO2/C shows higher reversible capacity and good cycling performance than that of pure SnO2. ► A further electrochemical conversion reaction of SnO2/C is proposed according to the experimental and theoretical evidences.
High-resolution mapping of fuel combustion and CO2 emission provides valuable information for modeling pollutant transport, developing mitigation policy, and for inverse modeling of CO2 fluxes. ...Previous global emission maps included only few fuel types, and emissions were estimated on a grid by distributing national fuel data on an equal per capita basis, using population density maps. This process distorts the geographical distribution of emissions within countries. In this study, a sub-national disaggregation method (SDM) of fuel data is applied to establish a global 0.1° × 0.1° geo-referenced inventory of fuel combustion (PKU-FUEL) and corresponding CO2 emissions (PKU-CO2) based upon 64 fuel sub-types for the year 2007. Uncertainties of the emission maps are evaluated using a Monte Carlo method. It is estimated that CO2 emission from combustion sources including fossil fuel, biomass, and solid wastes in 2007 was 11.2 Pg C yr−1 (9.1 Pg C yr−1 and 13.3 Pg C yr−1 as 5th and 95th percentiles). Of this, emission from fossil fuel combustion is 7.83 Pg C yr−1, which is very close to the estimate of the International Energy Agency (7.87 Pg C yr−1). By replacing national data disaggregation with sub-national data in this study, the average 95th minus 5th percentile ranges of CO2 emission for all grid points can be reduced from 417 to 68.2 Mg km−2 yr−1. The spread is reduced because the uneven distribution of per capita fuel consumptions within countries is better taken into account by using sub-national fuel consumption data directly. Significant difference in per capita CO2 emissions between urban and rural areas was found in developing countries (2.08 vs. 0.598 Mg C/(cap. × yr)), but not in developed countries (3.55 vs. 3.41 Mg C/(cap. × yr)). This implies that rapid urbanization of developing countries is very likely to drive up their emissions in the future.
The unique thermal history of different metal additive manufacturing processes would have profound impacts on the resulting microstructure and material properties. However, few have conducted ...benchmark research on the impacts. This work provides a comprehensive benchmark comparison on microstructure, mechanical properties, and their underlying mechanisms in selective laser melting (SLM), electron beam melting (EBM), and mill-annealing of Ti–6Al–4V alloys. The results have shown that the SLMed and EBMed samples possess very fine acicular α′ martensite while the conventional mill-annealed ones have granular α phase. The SLMed samples exhibit the highest tensile and yield strength resulted from the combined effects of refined α’ martensite and high microscale residual stress. The lowest tensile and yield strength and intermediate elongation of the EBMed samples are attributed to the relatively high number of type-II pores and in-situ annealing for residual stress relief during the printing process. The mill-annealed samples have the highest elongation due to the fully dense structure, the negligible microscale residual stress, and favorable grain orientation. It is expected to improve the ductility of SLMed samples via appropriate post-annealing and enhance the strength of EBMed samples by reducing the number of type-II pores through process optimization. The fundamental differences in microstructure and properties are attributed to the unique thermal histories of the concerned processes.
•EBMed samples possess more type- II pores and uncertain mechanical properties.•SLMed samples have the highest strength due to refined α′ and residual micro stress.•Mill-annealed have the largest elongation due to dense structure and favorable texture.
The metabolic responses of cows undergo substantial changes during the transition from late pregnancy to early lactation. However, the molecular mechanisms associated with these changes in ...physiological metabolism have not been clearly elucidated. The objective of this study was to investigate metabolic changes in transition cows from the perspective of plasma metabolites. Plasma samples collected from 24 multiparous dairy cows on approximately d 21 prepartum and immediately postpartum were analyzed using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. In conjunction with multidimensional statistical methods (principal component analysis and orthogonal partial least squares discriminant analysis), differences in plasma metabolites were identified using the t-test and fold change analysis. Sixty-seven differential metabolites were identified consisting of AA, lipids, saccharides, and nucleotides. The levels of 32 plasma metabolites were significantly higher and those of 35 metabolites significantly lower after parturition than on d 21 prepartum. Pathway analysis indicated that the metabolites that increased from late pregnancy to early lactation were primarily involved in lipid metabolism and energy metabolism, whereas decreased metabolites were related to AA metabolism.
Circular electron positron colliders, such as the CEPC and FCC-ee, have been proposed to measure Higgs boson properties precisely, test the Standard Model, search for physics beyond the Standard ...Model, and so on. One of the important goals of these colliders is to measure the
W
boson mass with great precision by taking data around the
W
-pair production threshold. In this paper, the data-taking scheme is investigated to maximize the achievable precisions of the
W
boson mass and width with a threshold scan, when various systematic uncertainties are taken into account. The study shows that an optimal and realistic data-taking scheme is to collect data at three center-of-mass energies and that precisions of 1.0 MeV and 3.4 MeV can be achieved for the mass and width of the
W
boson, respectively, with a total integrated luminosity of
L
=
3.2
ab
-
1
and several assumptions of the systematic uncertainty sources.
The deformation mechanisms and associated microstructure changes during tensile loading of an annealed twinning-induced plasticity steel with chemical composition Fe–20Mn–3Si–3Al–0.045C (wt.%) were ...systematically investigated using in situ time-of-flight neutron diffraction in combination with post mortem transmission electron microscopy (TEM). The initial microstructure of the investigated alloy consists of equiaxed γ grains with the initial α′-phase of ∼7% in volume. In addition to dislocation slip, twinning and two types of martensitic transformations from the austenite to α′- and ε-martensites were observed as the main deformation modes during the tensile deformation. In situ neutron diffraction provides a powerful tool for establishing the deformation mode map for elucidating the role of different deformation modes in different strain regions. The critical stress is 520MPa for the martensitic transformation from austenite to α′-martensite, whereas a higher stress (>600MPa) is required for actuating the deformation twin and/or the martensitic transformation from austenite to ε-martensite. Both ε- and α′-martensites act as hard phases, whereas mechanical twinning contributes to both the strength and the ductility of the studied steel. TEM observations confirmed that the twinning process was facilitated by the parent grains oriented with 〈111〉 or 〈110〉 parallel to the loading direction. The nucleation and growth of twins are attributed to the pole and self-generation formation mechanisms, as well as the stair-rod cross-slip mechanism.
The Cenozoic history of the Tibetan Plateau topography is critical for understanding the evolution of the Indian‐Eurasian collision, climate, and biodiversity. However, the long‐term growth and ...landscape evolution of the Tibetan Plateau remain ambiguous, it remains unclear if plateau uplift occurred soon after the India‐Asia collision in the Paleogene (∼50–25 Ma) or later in the Neogene (∼20–5 Ma). Here, we reproduce the uplift history of the southeastern Tibetan Plateau using a 2D landscape evolution model, which simultaneously solves fluvial erosion and sediment transport processes in the drainage basins of the Three Rivers region (Yangtze, Mekong, and Salween Rivers). Our model was optimized through a formal inverse analysis with 20,000 forward simulations, which aims to reconcile the transient states of the present‐day river profiles. The results, compared to existing paleoelevation and thermochronologic data, suggest initially low elevations (∼300–500 m) during the Paleogene, followed by a gradual southeastward propagation of topographic uplift of the plateau margin.
Plain Language Summary
When and how was formed the Tibetan Plateau which includes the highest mountains in the world? The answer is critical to decipher between competing models trying to explain how the Indian and Asian tectonic plates behaved when they collided. It is also a major constraint on the evolution of Asian mountain biodiversity, Asian monsoons, and even global climate. However, current estimates of past Tibetan elevation are contradictory, some arguing for a high plateau since the onset of the India‐Asia collision over 50 million years ago, while others favor the region remained low until a sudden rise 25 million years ago. Here, we use a numerical model of landscape evolution to test various hypothesis focusing on the southeastern Tibetan Plateau. We compared the results to see how they fit with the observed river profiles of the Three Rivers. The best fits were obtained with low elevations between 50 and 25 million years ago, and a more gradual growth toward the southeast of the high‐elevated plateau until present day.
Key Points
We constrained the uplift history of the southeastern (SE) Tibetan Plateau by performing inversion of the Three Rivers profiles
The inversion suggests that SE Tibet was at a low elevation until 50–25 Ma, followed by gradual outward growth until 0 Ma
Our modeling does not support Paleogene formation of the SE Tibetan Plateau with a major subsequent degradation via upstream fluvial erosion
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