| 1. |
- Yi, Chuixiang, et al.
(författare)
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Climate control of terrestrial carbon exchange across biomes and continents
- 2010
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid-and high-latitudes, (2) a strong function of dryness at mid-and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 degrees N). The sensitivity of NEE to mean annual temperature breaks down at similar to 16 degrees C (a threshold value of mean annual temperature), above which no further increase of CO2 uptake with temperature was observed and dryness influence overrules temperature influence.
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| 2. |
- Liu, Yongkui, et al.
(författare)
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Logistics-involved service composition in a dynamic cloud manufacturing environment : A DDPG-based approach
- 2022
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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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| 3. |
- Song, Wei, et al.
(författare)
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Kinetics and pathway of atrazine degradation by a novel method : Persulfate coupled with dithionite
- 2019
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 373, s. 803-813
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Tidskriftsartikel (refereegranskat)abstract
- Efficient and environmentally friendly activation methods of persulfate (PS) have gained growing attention in the remediation of water or soil polluted by organic contaminants. Among all, the exploration of effective and applicable method for the PS activation becomes one of the hottest topics in the field of organic degradation. Dithionite (DTN) was employed in this study to activate PS and applied to degrade Atrazine (ATZ) without secondary pollution. ATZ could be completely degraded within 90 min by PS/DTN system. ATZ degradation by PS obeyed the pseudo-first-order kinetics and the rate constant values increased from (4.71-5.05) x10(-3) min(-1) to (4.59-5.09) x10(-2) min(-1) with the addition of DTN. Sulfate radicals were verified to be the dominant reactive species through the radical scavenging experiment. PS/DTN system can remain a strong oxidative ability in the range of pH below 9.0. The presence of Cl-, natural organic matter (NOM), and high concentration of HCO3- may inhibit the removal of ATZ while the low concentration of HCO3- can slightly promote the degradation. It was found that the degradation pathways of ATZ by PS/DTN involved de-chlorination and hydroxylation, de-alkylation, and de-amination by the reactive species. The study reveals that PS/DTN system has the broad application prospect in the treatment of refractory pollutants.
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| 4. |
- Wang, Jingxin, et al.
(författare)
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Label-free quantitative comparison of cerebrospinal fluid glycoproteins and endogenous peptides in subjects with Alzheimer's disease, mild cognitive impairment, and healthy individuals.
- 2016
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Ingår i: Proteomics. Clinical applications. - : Wiley. - 1862-8354 .- 1862-8346. ; 10:12, s. 1225-1241
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this study is to investigate putative molecular dynamic changes in cerebrospinal fluids (CSFs) collected from individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD) as compared to healthy controls.The CSF samples from 12 subjects comprised of four cognitively normal individuals and eight patients with MCI and AD, respectively. Two aliquots of each CSF samples (total 1 mL) of each participant are used for this study. Endogenous peptide separations are performed using 10000 molecular weight cut-off filters followed by LC-MS/MS identification and quantitation while lectin-enrichment chromatography is used to enrich glycoproteins in CSF followed by trypsin digestion and subsequent LC-MS/MS for shotgun identification and label-free quantitation.Using an optimized submicrogram peptide separation with molecular weight cut-off filtration and an in house-constructed database, 645 peptides are identified. Glycoproteins are enriched by lectin affinity chromatography, resulting in 795 identified proteins. The discovery and alterations of proSAAS-derived peptides and transthyretin are described and their roles in AD are discussed.Comprehensive identification of endogenous CSF peptidome is achieved. Fifteen proteins are found to be differentially expressed among the three groups. The dynamic changes of transthyretin are reported for the first time.
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| 5. |
- Wang, Shuyun, et al.
(författare)
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Local thermal injury induces general endothelial cell contraction through p38 MAP kinase activation
- 2014
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 122:9, s. 832-841
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells (ECs) of thin-walled blood vessels form a barrier between blood and tissue. As a response to inflammation, the EC junctions widen and gaps form, resulting in compromised barrier functions. Although the mechanisms behind the establishment of these changes are still incompletely understood, one known reason is actomyosin-dependent actin rearrangement. Here, by using atomic force microscopy and a combination of confocal microscopy methods, we are the first to report that thermal injury induces general venular hyperpermeability and that serum from burned rats induces EC actin rearrangement, contraction, as well as tight-junction damage. Inhibition of the p38 mitogen-activated protein kinase (p38MAPK) largely ameliorates resulting vascular dysfunction by significantly reducing EC stress-fiber formation, contraction, volume changes and tight-junction damage, thereby greatly reducing the appearance of EC gaps. The findings may be of importance for the design of future pharmacotherapies aiming to ease the severe general vascular dysfunction that follows extensive burns.
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