| 1. |
- Jiang, Jingjing, et al.
(author)
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Sino-European Differences in the Genetic Landscape and Clinical Presentation of Pheochromocytoma and Paraganglioma
- 2020
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 105:10
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Journal article (peer-reviewed)abstract
- Context: Pheochromocytomas and paragangliomas (PPGLs) are characterized by distinct genotype-phenotype relationships according to studies largely restricted to Caucasian populations.Objective: To assess for possible differences in genetic landscapes and genotype-phenotype relationships of PPGLs in Chinese versus European populations.Design: Cross-sectional study.Setting: 2 tertiary-care centers in China and 9 in Europe.Participants: Patients with pathologically confirmed diagnosis of PPGL, including 719 Chinese and 919 Europeans.Main Outcome Measures: Next-generation sequencing performed in tumor specimens with mutations confirmed by Sanger sequencing and tested in peripheral blood if available. Frequencies of mutations were examined according to tumor location and catecholamine biochemical phenotypes.Results: Among all patients, higher frequencies of HRAS, FGFR1, and EPAS1 mutations were observed in Chinese than Europeans, whereas the reverse was observed for NF1, VHL, RET, and SDHx. Among patients with apparently sporadic PPGLs, the most frequently mutated genes in Chinese were HRAS (16.5% [13.6-19.3] vs 9.8% [7.6-12.1]) and FGFR1 (9.8% [7.6-12.11 vs 2.2% [1.1-3.3]), whereas among Europeans the most frequently mutated genes were NF1 (15.9% [13.2-18.6) vs 6.6% [4.7-8.5)) and SDHx (10.7% [8.4-13.0] vs 4.2% [2.6-5.7]). Among Europeans, almost all paragangliomas lacked appreciable production of epinephrine and identified gene mutations were largely restricted to those leading to stabilization of hypoxia inducible factors. In contrast, among Chinese there was a larger proportion of epinephrine-producing paragangliomas, mostly due to HRAS and FGFR1 mutations.Conclusions: This study establishes Sino-European differences in the genetic landscape and presentation of PPGLs, including ethnic differences in genotype-phenotype relationships indicating a paradigm shift in our understanding of the biology of these tumors.
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| 2. |
- Dong, Jianqi, et al.
(author)
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Centimeter-long III-Nitride nanowires and continuous-wave pumped lasing enabled by graphically epitaxial lift-off
- 2020
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In: Nano Energy. - : Elsevier BV. - 2211-2855. ; 78
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Journal article (peer-reviewed)abstract
- It remains a big challenge to elongate one-dimensional (1D) semiconductor nanowires (NWs), which can be attractive platforms for miniaturizing and/or integrating macroscopic devices, into centimeter-scale length. Herein, we report the innovative preparation of single-crystalline III-nitride NWs, with unprecedented length above 2 cm and the aspect ratio above 6000, by graphically epitaxial lifting-off (GELO) the epitaxial films on sapphire. The proposed GELO technology involves isotropic dry etching and selectively electrochemical (EC) etching. Reaction kinetics study of the EC etching indicate that two-steps processes are included, which is, to our best knowledge, firstly revealed and experimentally confirmed. Centimeter-long freestanding NWs, with predesigned structure of homogeneous GaN, p-GaN/(InGaN/GaN)6 quantum-wells/n-GaN (simply InGaN/GaN QWs) and AlGaN/AlN/GaN heterostructure, are successfully obtained and exhibit superior morphological uniformity and robust flexibility. Optical properties of the released InGaN/GaN QW-NWs were well optimized owing to the relieved intrinsic strain. Random lasing behavior was unexpectedly observed by continuous-wave excitation of the individual InGaN/GaN QW-NW, with a low threshold of 232 kW•cm-2. This work represents a low-cost and economic approach to yield structure-engineerable super-long III-nitride NWs, which would promote the development and integration of optoelectronic nanodevices.
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| 3. |
- Guo, Jiawei, et al.
(author)
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Bimetallic Sulfides with Vacancy Modulation Exhibit Enhanced Electrochemical Performance
- 2024
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In: Advanced Functional Materials. - 1616-3028 .- 1616-301X. ; 34:28
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Journal article (peer-reviewed)abstract
- Transition bimetallic sulfides show significant promise for energy-related applications because of their plentiful active sites and synergistic redox activity. However, limited pore size and low-conductivity issues hinder their application. The structure of NiCo-S with rich sulfur vacancies is first predicted by density functional theory (DFT) calculations. Different sulfur vacancy concentrations are modeled by DFT calculations, and the results confirm that sulfur vacancies enhance the conductivity of the electrode material and are more beneficial for the adsorption of OH* species. It is verified by the differential charge density that the electric field formed on the surface of the electrode can lead to strong interfacial interactions by electron aggregation, which promotes electron/ion transfer kinetics. Furthermore, NiCo-S nanosheets are prepared on carbon cloth enriched with different concentrations of sulfur vacancies (denoted as NiCo-Sv-x, with x representing the concentration of sulfur vacancies) by sulfide etching NiCo-MOF and annealing under H2/Ar atmosphere. The NiCo-Sv-x electrodes obtained are applied to the cathode of supercapacitors and the anode of the oxygen evolution reaction. Through combining experimental and theoretical analysis, the effect of vacancy defect engineering on the electrochemical performance of the electrode materials is further confirmed. This work constructs transition metal sulfides with different sulfur vacancy concentrations through DFT model prediction and experimental validation, further confirming the effect of vacancy defect engineering on the electrochemical performance of electrode materials. Therefore, this modulation of sulfur vacancy concentration by vacancy defects contributes to the construction of electrode materials with excellent performance for energy applications.
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| 4. |
- Sun, Xiaoyu, et al.
(author)
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Tuning Mo/W ratio to improve high temperature oxidation resistance of single crystal nickel base superalloys
- 2024
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In: Materials Today Communications. - : ELSEVIER. - 2352-4928. ; 38
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Journal article (peer-reviewed)abstract
- The effect of different Mo/W ratios of three single crystal nickel base superalloys on the oxidation behavior was investigated at 1100 degrees C. Both isothermal and cyclic oxidation tests showed that increasing Mo/W ratio corresponds to lower weight change and improved resistance. The microscopic observation uncovers that the harmful effect of Mo is limited by the dense Al2O3 scale. In contrast, excessive W leads to fast growth of interlayer and its premature spallation. This research proposes and verifies a new way to improve oxidation resistance of alloy, namely, balancing the harmful effect of refractory elements.
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| 5. |
- Xi, Fengming, et al.
(author)
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Substantial global carbon uptake by cement carbonation
- 2016
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In: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 9:12, s. 880-883
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Journal article (peer-reviewed)abstract
- Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO 2 emissions from all industrial process and fossil-fuel combustion in 2013. Considerable attention has been paid to quantifying these industrial process emissions from cement production, but the natural reversal of the process - carbonation - has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondary use of concrete waste to estimate regional and global CO 2 uptake between 1930 and 2013 using an analytical model describing carbonation chemistry. We find that carbonation of cement materials over their life cycle represents a large and growing net sink of CO 2, increasing from 0.10 GtC yr â '1 in 1998 to 0.25 GtC yr â '1 in 2013. In total, we estimate that a cumulative amount of 4.5 GtC has been sequestered in carbonating cement materials from 1930 to 2013, offsetting 43% of the CO 2 emissions from production of cement over the same period, not including emissions associated with fossil use during cement production. We conclude that carbonation of cement products represents a substantial carbon sink that is not currently considered in emissions inventories.
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| 6. |
- Xiao, Manjun, et al.
(author)
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Approaching 19% efficiency and stable binary polymer solar cells enabled by a solidification strategy of solvent additive
- 2023
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In: Science in China Series B. - : SCIENCE PRESS. - 1674-7291 .- 1869-1870. ; 66, s. 1500-1510
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Journal article (peer-reviewed)abstract
- Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells (PSCs). However, the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents, while their trace residues may reduce device stability. Herein, an effective strategy of "solidification of solvent additive (SSA)" has been developed to convert additive from liquid to solid, by introducing a covalent bond into low-cost solvent diphenyl sulfide (DPS) to synthesize solid dibenzothiophene (DBT) in one-step, which achieves optimized morphology thus promoting efficiency and device stability. Owing to the fine planarity and volatilization of DBT, the DBT-processed films achieve ordered molecular crystallinity and suitable phase separation compared to the additive-free or DPS-treated ones. Importantly, the DBT-processed device also possesses improved light absorption, enhanced charge transport, and thus a champion efficiency of 11.9% is achieved in the PM6:Y6-based PSCs with an excellent additive component tolerance, reproducibility, and stability. Additionally, the DBT-processed PM6:L8-BO-based PSCs are further fabricated to study the universality of SSA strategy, offering an impressive efficiency approaching 19% as one of the highest values in binary PSCs. In conclusion, this article developed a promising strategy named SSA to boost efficiency and improve stability of PSCs.
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| 7. |
- Zhong, Shenghui, et al.
(author)
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Cool flame wave propagation in high-pressure spray flames
- 2023
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In: Proceedings of the Combustion Institute. - : Elsevier BV. - 1540-7489. ; 39:2, s. 2513-2522
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Journal article (peer-reviewed)abstract
- Cool flame has an important impact on the performance and emission of advanced low-temperature combustion (LTC) internal combustion engines (ICEs) in which the liquid fuel is injected earlier at a lower ambient temperature (Tam) than that in the conventional diesel combustion engines. However, the cool flame characteristics of spray combustion under ICEs conditions are not fully understood, e.g., the effect of cool flame on the spray ignition and flame stabilization is not well studied. In this paper, the so-called cool flame wave propagation (CFWP) in the Engine Combustion Networks Spray A flames at three ambient temperatures Tam (800 K, 900 K and 1000 K) is analyzed using the data from large eddy simulation with an improved Eulerian based transported probability density function sub-grid combustion model. A good agreement between the LES results and experimental data is obtained for the spray liquid penetration length, vapor fuel penetration length, mean pressure rise profile, and flame liftoff length. It is shown that CFWP in the spray ignition process promotes the ignition of the fuel-rich and cold reactant mixture, leading to the most reactive mixture shifting toward fuel-richer locations due to the spatial stratification of temperature and concentration, and turbulent mixing. As a result, the high temperature ignition (HTI) can be shortened compared to the ignition in the homogeneous mixture. At Tam = 800 K, the HTI kernels are consistently formed following the CFWP propagating toward the spray head region. However, as Tam increases, the spatial correlation between HTI kernels and CFWP fronts is weakened. On the other hand, the turbulent mixing (quantified using local scalar dissipation rate) contributes more to the formation of HTI kernels at higher Tam. The present results indicate that CFWP is more profound at lower Tam in the spray ignition process. Finally, it is found that cool flame propagates mainly into pre-reacted fuel-rich mixture in an ignition wave propagation mode from the spray upstream region toward downstream region, whereas the ignition assisted flame mode is found in the spray upstream region where the combustion heat release is negligible.
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