| 1. |
- Liu, Haifeng, et al.
(författare)
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Laser diagnostics and chemical kinetic analysis of PAHs and soot in co-flow partially premixed flames using diesel surrogate and oxygenated additives of n-butanol and DMF
- 2018
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Ingår i: Combustion and Flame. - : Elsevier BV. - 0010-2180. ; 188, s. 129-141
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Tidskriftsartikel (refereegranskat)abstract
- Effects of oxygenated fuels on soot reduction strongly depend on the base fuel. Interesting candidates from oxygenated fuels in this respect include both n-butanol and 2,5-dimethylfuran (DMF), because they have already been used in diesel engines recently. However, information is rather limited on n-butanol and DMF added into a diesel fuel surrogate in fundamental flames to investigate the mechanism of soot reduction. In the current work, both n-butanol and DMF was successively added into diesel surrogate (80% n-heptane and 20% toluene in volume, named as T20) in co-flow partially premixed flames. The effects of different oxygenated structures on polycyclic aromatic hydrocarbons (PAHs) and soot were investigated at the same oxygen weight fractions of 4% and the same volume fractions of 20%. The diagnostics on PAHs, soot volume fractions and soot sizes were conducted by using both laser-induced fluorescence (LIF) and two-color laser-induced incandescence (2C-LII). A combined detailed kinetic model (n-heptane/toluene/butanols/DMF/PAHs) has been obtained in order to clarify the chemical effects of the different oxygenated fuels on PAHs formation. Results show that the reduced toluene content due to the addition of oxygenated fuels is the dominant factor for the reduction of soot, as compared with the base fuel of T20. The oxygenated structure of n-butanol has a higher ability to reduce PAHs and soot as compared with the addition of DMF. This is due to the fact that the consumption of DMF leads to much formation of C5H5 which enhances the formation of PAHs and subsequent soot. However, the formation of PAHs can be inhibited remarkably as blending n-butanol because only small hydrocarbons like C2H2 and C3H3 etc. are formed. The formation rate of A4 is more similar to that of soot in comparison with the smaller ring aromatics. For the size of soot particles, the distribution range is shrunk from 19–70 nm for T20 to 20–40 nm for the addition of oxygenated fuels. As compared to the effects of oxygenated structures, DMF20 presents a little wider distribution on soot sizes than that of B16.8. Some larger soot particles are detected in DMF20 flame but cannot be found in B20 flame.
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| 2. |
- Zhao, Haifeng, et al.
(författare)
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Efficient and High-Luminance Perovskite Light-Emitting Diodes Based on CsPbBr3 Nanocrystals Synthesized from a Dual-Purpose Organic Lead Source
- 2020
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829.
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Tidskriftsartikel (refereegranskat)abstract
- Rational engineering of the surface properties of perovskite nanocrystals (PeNCs) is critical to obtain light emitters with simultaneous high photoluminescence efficiency and excellent charge transport properties for light-emitting diodes (LEDs). However, the commonly used lead halide sources make it hard to rationally optimize the surface compositions of the PeNCs. In addition, previously developed ligand engineering strategies for conventional inorganic nanocrystals easily deteriorate surface properties of the PeNCs, bringing additional difficulties in optimizing their optoelectronic properties. In this work, a novel strategy of employing a dual-purpose organic lead source for the synthesis of highly luminescent PeNCs with enhanced charge transport property is developed. Lead naphthenate (Pb(NA)(2)), of which the metal ions work as lead sources while the naphthenate can function as the surface ligands afterward, is explored and the obtained products under different synthesis conditions are comprehensively investigated. Monodispersed cesium lead bromide (CsPbBr3) with controllable size and excellent optical properties, showing superior photoluminescence quantum yields up to 80%, is obtained. Based on the simultaneously enhanced electrical properties of the Pb(NA)(2)-derived PeNCs, the resultant LEDs demonstrate a high peak external quantum efficiency of 8.44% and a superior maximum luminance of 31 759 cd cm(-2).
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| 3. |
- Ausin, Israel, et al.
(författare)
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DNA methylome of the 20-gigabase Norway spruce genome
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 113:50, s. E8106-E8113
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Tidskriftsartikel (refereegranskat)abstract
- DNA methylation plays important roles in many biological processes, such as silencing of transposable elements, imprinting, and regulating gene expression. Many studies of DNA methylation have shown its essential roles in angiosperms (flowering plants). However, few studies have examined the roles and patterns of DNA methylation in gymnosperms. Here, we present genome-wide high coverage single-base resolution methylation maps of Norway spruce (Picea abies) from both needles and somatic embryogenesis culture cells via whole genome bisulfite sequencing. On average, DNA methylation levels of CG and CHG of Norway spruce were higher than most other plants studied. CHH methylation was found at a relatively low level; however, at least one copy of most of the RNA-directed DNA methylation pathway genes was found in Norway spruce, and CHH methylation was correlated with levels of siRNAs. In comparison with needles, somatic embryogenesis culture cells that are used for clonally propagating spruce trees showed lower levels of CG and CHG methylation but higher level of CHH methylation, suggesting that like in other species, these culture cells show abnormal methylation patterns.
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| 4. |
- Cao, Yongkang, et al.
(författare)
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Protic Ionic Liquid‐Based Deep Eutectic Solvents with Multiple Hydrogen Bonding Sites for Efficient Absorption of NH3
- 2020
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Ingår i: AIChE Journal. - : American Institute of Chemical Engineers. - 0001-1541 .- 1547-5905. ; 66:8
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Tidskriftsartikel (refereegranskat)abstract
- The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL‐based deep eutectic solvents (DESs) for NH3 absorption. The results indicated that these PIL‐based DESs not only have fast absorption rate, but also exhibit exceptional NH3 capacity and excellent recyclability. The highest mass capacity of 211 mg NH3/g DES was achieved by [Im][NO3]/EG with molar ratio of 1:3, and was higher than all the reported ILs and IL‐based DESs, which was originated from multiple hydrogen bonding between acidic H and hydroxyl groups of the DESs and NH3. This work will provide useful idea for designing IL‐based solvents for NH3 separation applications.
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| 5. |
- Chen, Hongting, et al.
(författare)
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High-Efficiency Formamidinium Lead Bromide Perovskite Nanocrystal-Based Light-Emitting Diodes Fabricated via a Surface Defect Self-Passivation Strategy
- 2020
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Formamidinium lead bromide (FAPbBr(3)) nanocrystals (NCs) demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability. However, the abundant defects at the surface of the NCs act as charge trapping centers and significantly increase the trap-assisted nonradiative recombination channels, hampering the performance improvement of LEDs based on FAPbBr(3) NCs. Herein, a facile self-passivation strategy of the surface defects is developed by introducing excess formamidinium bromide (FABr) during the colloidal synthesis of NCs, leading to much improved photoluminescence quantum yield (PLQY) of the obtained NCs. In addition, enhanced charge transport property is measured in the assembled films owing to the simultaneously declined insulating ligands at the surface of NCs. The molar ratio of FABr and PbBr2 is rationally optimized during the synthesis of NCs and high-efficient green-emissive LEDs are fabricated with a champion current efficiency of 76.8 cd A(-1), corresponding to an external quantum efficiency of 17.1%, which is among the best-performing green LEDs based on perovskite NCs so far.
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| 6. |
- Cui, Yanqing, et al.
(författare)
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Optical diagnostics of misfire in partially premixed combustion under low load conditions
- 2022
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 329
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Tidskriftsartikel (refereegranskat)abstract
- To clarify the misfire mechanism is important for stabilizing combustion in partially premixed combustion (PPC) under low load. Fuel-tracer planar laser-induced fluorescence (PLIF), formaldehyde PLIF, flame and OH* natural luminosity imaging were utilized to qualify the local equivalence ratio, low-temperature reaction and the high-temperature flame features in an optical engine. Results show that in high direct injection (DI) pressure (1000 bar), due to excessive premixing, the local equivalence ratio in the initial timing of the high temperature heat release (HTHR) is low. Although the auto-ignition flame kernels are formed in high DI pressure, they cannot stably develop, resulting in misfire during the flame development process. In late DI timing (-5 crank angle degree after top dead center, °CA ADTC), since the whole heat release process occurs in the expansion stroke, the in-cylinder temperature and pressure continue decreasing. Although the local equivalence ratio in some regions is high enough, the in-cylinder thermodynamic environment does not support the generation of more auto-ignition flame kernels, thus a small amount of auto-ignition flame kernels can only develop through flame propagation. In short, the misfire of PPC occurs in regions where the equivalence ratio is low or the in-cylinder thermodynamic environment does not further support flame development. Therefore, the trade-off relationship between equivalence ratio and temperature determines the formation of auto-ignition kernels. The local equivalence ratio and temperature distribution near the initial timing of HTHR is the key factor to ensure the subsequent stable combustion. Taking the ambient pressure of 18 bar as an example, the boundary condition where the autoignition kernels are most likely formed or the charge is most likely ignited by the nearby flame kernels is in the range of 0.53–0.62 for equivalence ratio and 740–757 K for temperature. The misfire region most likely appears when the equivalence ratio is lower than 0.49. It can be concluded that the misfire of PPC results from the synergistic effect of local equivalent ratio and temperature. The controlling parameters of injection pressure and injection timing are actually optimizing the suitable combinations of equivalence ratio and temperature to stabilize combustion.
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| 7. |
- Dai, Baomin, et al.
(författare)
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Environmental and economical analyses of transcritical CO2 heat pump combined with direct dedicated mechanical subcooling (DMS) for space heating in China
- 2019
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Ingår i: Energy Conversion and Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0196-8904 .- 1879-2227. ; 198
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Tidskriftsartikel (refereegranskat)abstract
- An environmental and economical assessment model is developed, in order to evaluate the performances of transcritical CO2 heat pump system with dedicated mechanical subcooling (CO2 HPDMS). Introducing DMS to traditional CO2 HP system is an efficient method to reduce the primary energy consumption, which can be further decreased by using small temperature difference fan-coil unit (STD-FCU) as heating terminal. Using CO2 heat pump system for space heating is an environmentally-friendly heating method. The corresponding pollution emissions are only inferior to those of the wall hanging gas heater. The initial capital cost and operating cost of CO2 HPDMS system are both lower than those of CO2 HPBASE system, and the CO2 compressor cost accounts for about 80% of the overall initial capital cost. In contrast to other traditional heating methods, the payback periods of CO2 HPDMS system are not more than 9 years in most cases. If the CO2 compressor and electricity price are reduced by 20% and 28.79% respectively, the life cycle cost of CO2 HPDMS will be competitive to that of coal-fired boiler. In China, it is a promising way to adopt CO2 HPDMS for space heating in the near future with the assistant of electricity price subsidy and compressor price reduction.
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| 8. |
- Hussain, Shahid, et al.
(författare)
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Efficient Selective Carbon Dioxide Separation via Task-Specific Ionic Liquids Incorporated in ZIF-8
- 2024
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 40:16, s. 8636-8644
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Tidskriftsartikel (refereegranskat)abstract
- Owing to the rapid increase in anthropogenic emission of carbon dioxide (CO2) in the atmosphere, which has resulted in a number of global climate challenges, a decrease in CO2 emissions is urgently needed in the current scenario. This study focuses on the development and characterization of composites for carbon dioxide (CO2) separation. The composites consist of two task-specific ionic liquids (TSILs), namely, tetramethylgunidinium imidazole [TMGHIM] and tetramethylgunidinium phenol [TMGHPhO], impregnated in ZIF-8. The performance of CO2 separation, including sorption capacity and selectivity, was evaluated for pristine ZIF-8 and composites of TMGHIM@ZIF-8 and TMGHPhO@ZIF-8. To demonstrate the thermal stability of the material, thermogravimetric analysis (TGA) was performed. Additionally, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to showcase the crystal structures and morphology. Fourier transform infrared spectroscopy (FTIR) and BET were also utilized to confirm the successful incorporation of TSILs into ZIF-8. The composite synthesized with TMGHIM@ZIF-8 demonstrated superior CO2 sorption performance as compared with TMGHPhO@ZIF-8. This is attributed to its strong attraction toward CO2, resulting in a higher CO2/CH4 selectivity of 110 while pristine MOFs showed 12 that is 9 times higher than that of the pristine ZIF-8. These TSILs@ZIF-8 composites have significant potential in designing sorbent materials for efficient acid gas separation applications.
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| 9. |
- Liang, Huagang, et al.
(författare)
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Logistics-involved QoS-aware service composition in cloud manufacturing with deep reinforcement learning
- 2021
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Ingår i: Robotics and Computer-Integrated Manufacturing. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0736-5845 .- 1879-2537. ; 67
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Tidskriftsartikel (refereegranskat)abstract
- Cloud manufacturing is a new manufacturing model that aims to provide on-demand manufacturing services to consumers over the Internet. Service composition is an essential issue as well as an important technique in cloud manufacturing (CMfg) that supports construction of larger-granularity, value-added services by combining a number of smaller-granularity services to satisfy consumers' complex requirements. Meta-heuristics algorithms such as genetic algorithm, particle swarm optimization, and ant colony algorithm are frequently employed for addressing service composition issues in cloud manufacturing. These algorithms, however, require complex design flows and painstaking parameter tuning, and lack adaptability to dynamic environment. Deep re-inforcement learning (DRL) provides an alternative approach for solving cloud manufacturing service compo-sition (CMfg-SC) issues. DRL as model-free artificial intelligent methods enables a system to learn optimal service composition solutions through training, which can therefore circumvent the aforementioned problems with meta-heuristics algorithms. This paper is dedicated to exploring possible applications of DRL in CMfg-SC. A logistics-involved QoS-aware DRL-based CMfg-SC is proposed. A dueling Deep Q-Network (DQN) with prior-itized replay named PD-DQN is designed as the DRL algorithm. Effectiveness, robustness, adaptability, and scalability of PD-DQN are investigated, and compared with that of the basic DQN and Q-learning. Experimental results indicate that PD-DQN is able to effectively address the CMfg-SC problem.
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| 10. |
- Liu, Haifeng, et al.
(författare)
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Effects of Flame Temperature on PAHs and Soot Evolution in Partially Premixed and Diffusion Flames of a Diesel Surrogate
- 2019
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Ingår i: Energy and Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 33:11, s. 11821-11829
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, polycyclic aromatic hydrocarbons (PAHs) and soot formation in rich partially premixed flames and nonpremixed flames were studied using a blend of n-heptane and toluene. The flames were diluted with Ar, N2, and CO2 to control the flame temperature. Laser-induced fluorescence, laser-induced incandescence, and two-color pyrometry were used to study the effects of flame temperature on the PAHs and soot evolution. Results show that temperature distributions are similar for different gas dilutions at low flow rates. However, the higherature area increases dramatically in size at high flow rates and it depends on diluents in the order Ar > N2 > CO2 with regard to flame temperature. With an increase in the flow rate of Ar, the higher growth rate of flame temperature and bigger region of higherature region can lead to a higher growth rate from small to large PAHs and higher soot volume fraction. However, for CO2 dilution, the increased flow rate results in the increase of formation of large PAHs, but soot formation is reduced due to the fact that lower flame temperature suppresses the soot formation. Therefore, it can be concluded that the evolution of PAHs and soot strongly depends on flame temperature.
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| 11. |
- Liu, Yongkui, et al.
(författare)
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Logistics-involved service composition in a dynamic cloud manufacturing environment : A DDPG-based approach
- 2022
-
Ingår i: Robotics and Computer-Integrated Manufacturing. - : Elsevier BV. - 0736-5845 .- 1879-2537. ; 76, s. 102323-
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Tidskriftsartikel (refereegranskat)abstract
- Service composition as an important technique for combining multiple services to construct a value-added service is a major research issue in cloud manufacturing. Highly dynamic environments present great challenges to cloud manufacturing service composition (CMfg-SC). Most of previous studies employ heuristic algorithms to solve service composition issues in cloud manufacturing, which, however, are designed for specific problems and lack adaptability necessary to dynamic environment. Hence, CMfg-SC calls for new adaptive approaches. Recent advances in deep reinforcement learning (DRL) provide a new means for solving this issue. Based on DRL, we propose a Deep Deterministic Policy Gradient (DDPG)-based service composition approach to cloud manufacturing, with which optimal service composition solutions can be learned through repeated training. Performance of DDPG in solving CMfg-SC in both static and dynamic environments is examined. Results obtained with another DRL algorithm -Deep Q-Networks (DQN) and the traditional Ant Colony Optimization (ACO) are also presented. Comparison indicates that DDPG has better adaptability, robustness, and extensibility to dynamic environments than ACO, although ACO converges faster and its steady QoS value of the service composition solution is higher than that of DDPG by 0.997%. DDPG outperforms DQN in convergence speed and stability, and the QoS value of the service composition solution of DDPG is higher than that of DQN by 3.249%.
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| 12. |
- Tang, Qinglong, et al.
(författare)
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Study on ignition and flame development in gasoline partially premixed combustion using multiple optical diagnostics
- 2017
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Ingår i: Combustion and Flame. - : Elsevier BV. - 0010-2180. ; 177, s. 98-108
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Tidskriftsartikel (refereegranskat)abstract
- Gasoline partially premixed combustion (PPC) is a potential strategy to achieve high engine efficiency, as well as low NOx and soot emissions. But the in-cylinder combustion process of PPC is not well understood. In this paper, multiple optical diagnostics are applied to investigate the PPC ignition and flame development in a light-duty optical engine under single-injection condition. For the injection timing of −25 CA after top dead center (ATDC), the results indicate that the combustion process of gasoline PPC can be basically divided into four stages: 1) multiple auto-ignition kernels emerging in fuel-rich regions; 2) flame front propagation of the ignition kernels towards fuel-lean regions; 3) auto-ignition in the end-gas of fuel-lean regions; 4) a “burnout” stage in the whole combustion chamber after the main heat release process ends. The natural flame emission spectra from these four stages in PPC are analyzed. Distinct flame front propagation is verified during the early stages of the flame development process by both formaldehyde and OH planar laser-induced fluorescence (PLIF) imaging. The wide spread and late persistence of OH radicals after the main heat release process may account for the low soot emissions of gasoline PPC. The flame expansion speeds, determined by monitoring the flame fronts extracted from the combustion images, are much higher than that in SI (spark ignition) or SACI (spark-assisted compression ignition) combustion. With earlier fuel injection timing of −90 CA ATDC, the flame propagation process is less pronounced, and the sequential auto-ignition process prevails. Variation of the fuel stratification degree caused by the different fuel injection timings is responsible for this transformation in the flame development pattern for gasoline PPC.
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| 13. |
- Wang, Aozhe, et al.
(författare)
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Targeted lipidomics and inflammation response to six weeks of sprint interval training in male adolescents
- 2023
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 20:4
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Tidskriftsartikel (refereegranskat)abstract
- Lipids play an important role in coordinating and regulating metabolic and inflammatoryprocesses. Sprint interval training (SIT) is widely used to improve sports performance and healthoutcomes, but the current understanding of SIT-induced lipid metabolism and the correspondingsystemic inflammatory status modification remains controversial and limited, especially in maleadolescents. To answer these questions, twelve untrained male adolescents were recruited andunderwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygenconsumption (VO2peak), biometric data (weight and body composition), serum biochemical pa-rameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-densitylipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and tar-geted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1β, IL-2,IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β significantlydecreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition,the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05,fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatorymarkers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, andFFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers andcirculating lipid composition, offering health benefits to the population.
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| 14. |
- Zhang, Xiang, et al.
(författare)
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Graphene oxide-based polymeric membranes for broad water pollutant removal
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 5:122, s. 100651-100662
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Tidskriftsartikel (refereegranskat)abstract
- Graphene oxide (GO) and its derivatives display excellent removal abilities of water contaminants; however, the complex preparation process of GO-based adsorbents and difficult collection of GO sheets during the adsorption process limit their practical applications. Hence, three kinds of GO-based polymeric membranes with specific adsorption characteristics were fabricated by a facile blending method, including GO/PES membrane, reduced GO (RGO)/PES membrane, and polyethyleneimine (PEI) coated GO membrane of GO@PEI/PES membrane. The GO/PES membrane exhibited selective adsorption for cationic dyes, the RGO/PES membrane exhibited selective adsorption for endocrine disruptors, and the GO@PEI/PES membrane exhibited selective adsorption for anionic dyes. The adsorption data fitted the pseudo-second-order kinetic model and the Langmuir isotherm well, and the adsorption process was controlled by the interparticle diffusion. The thermodynamic studies indicated that the adsorption reactions were spontaneous and exothermic processes. The dynamic adsorption results indicated that the prepared membranes could be used in wastewater filtration. The study indicated that GO-based polymeric membranes with broad water pollutant removal could be fabricated by facile strategies, and the problem of difficult collection of GO sheets during and after adsorption process was solved.
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| 15. |
- Zhao, Haifeng, et al.
(författare)
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High-Brightness Perovskite Light-Emitting Diodes Based on FAPbBr(3) Nanocrystals with Rationally Designed Aromatic Ligands
- 2021
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Ingår i: ACS Energy Letters. - : AMER CHEMICAL SOC. - 2380-8195. ; 6:7, s. 2395-2403
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Tidskriftsartikel (refereegranskat)abstract
- Despite rapid developments of light-emitting diodes (LEDs) based on emerging perovskite nanocrystals (PeNCs), it remains challenging to achieve devices with integrated high efficiencies and high brightness because of the insulating long-chain ligands used for the PeNCs. Herein, we develop highly luminescent and stable formamidinium lead bromide PeNCs capped with rationally designed short aromatic ligands of 2-naphthalenesulfonic acid (NSA) for LEDs. Compared with commonly used oleic acid ligands, the NSA molecules not only preserve the surface properties of the PeNCs during the purification but also notably improve the electrical properties of the assembled emissive layers, ensuring efficient charge injection/transport in the devices. The resulting champion LED with electroluminescence approaching the Rec. 2020 green primary color demonstrates a high brightness of 67 115 cd cm(-2) and a peak external quantum efficiency of 19.2%. More impressively, the device shows negligibly decreased efficiency at an elevated brightness of 20 000 cd cm(-2) and a well-retained efficiency of over 10% at around 65 000 cd cm(-2), presenting a breakthrough in LEDs based on PeNCs.
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| 16. |
- Zhu, Minggu, et al.
(författare)
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Dietary Mustard Seeds (Sinapis alba Linn) Suppress 1,2-Dimethylhydrazine-Induced Immuno-Imbalance and Colonic Carcinogenesis in Rats
- 2012
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Ingår i: Nutrition and Cancer. - : Taylor and Francis (Routledge): STM, Behavioural Science and Public Health Titles / Taylor and Francis (Routledge). - 0163-5581 .- 1532-7914. ; 64:3, s. 464-472
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Tidskriftsartikel (refereegranskat)abstract
- In a Wistar rat model, prolonged supplementation of mustard seed (MS) to the diet significantly ameliorates the induction of colorectal carcinomas by 1,2-dimethylhydrazine (DMH). The expression of the splenocyte major histocompatibility complex class I (MHCI) was found significantly enhanced, whereas that of the major histocompatibility complex class II (MHCII) was significantly decreased. Compared to that of control animals, the proportion of spleenic B- and dendritic cells (DC) was amplified in the MS group. The expressions of MHCI, as well as that of MHCII, were increased in DC cells; whereas in B cells, MHCI expression was augmented but that of MHCII moderately decreased. The percentages of CD8+CD28+ and CD4+CD28+ cells were increased in the MS group, while the CD4+CD25+Foxp3+ subset was depressed. Plasma analysis showed that DMH-exposure induced amplified amounts of interleukin (IL)-4, IL-5, IL-10, and transforming growth factor-beta, whereas MS feeding counteracted this effect but enhanced IL-2,IL12p70,IL21, TNF-alpha, and interferon-gamma. In the SW480 colon adenocarcinoma cell-line, the cytotoxicity of spleenic T-cells from MS-fed animals was significantly increased. In the DMH-exposed rats, the expression of perforin in the spleenic T-cells was dramatically decreased, whereas MS abolished this depression. In summary, dietary MS suppresses DMH-induced immuno-imbalance as well as colon carcinogenesis in rats.
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