| 1. |
- Xu, Jianliang, et al.
(författare)
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Protective functions of ZO-2/Tjp2 expressed in hepatocytes and cholangiocytes against liver injury and cholestasis
- 2021
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 160:6, s. 2103-2118
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Liver tight junctions (TJs) establish tissue barriers that isolate bile from the blood circulation. TJP2/ZO-2-inactivating mutations cause progressive cholestatic liver disease in humans. Since the underlying mechanisms remain elusive, we characterized mice with liver-specific inactivation of Tjp2.METHODS: Tjp2 was deleted in hepatocytes, cholangiocytes, or both. Effects on the liver were assessed by biochemical analyses of plasma, liver and bile and .by EM, histology and immunostaining. TJ barrier permeability was evaluated using FITC-Dextran (4kDa). Cholic acid (CA) diet was used to assess susceptibility to liver injury.RESULTS: Liver-specific deletion of Tjp2 resulted in lower Cldn1 protein levels, minor changes to the TJ, dilated canaliculi, lower microvilli density and aberrant Radixin and BSEP distribution, without an overt increase in TJ permeability. Hepatic Tjp2-defcient mice presented with mild progressive cholestasis with lower expression levels of bile acid (BA) transporter Abcb11/Bsep and detoxification enzyme Cyp2b10. A CA-diet tolerated by control mice caused severe cholestasis and liver necrosis in Tjp2-deficient animals. TCPOBOP ameliorated CA-induced injury by enhancing Cyp2b10 expression and ursodeoxycholic acid provided partial improvement. Inactivating Tjp2 separately in hepatocytes or cholangiocytes only showed mild CA-induced liver injury.CONCLUSION: Tjp2 is required for normal cortical distribution of Radixin, canalicular volume regulation and microvilli density, Its inactivation deregulated expression of Cldn1 and key BA transporters and detoxification enzymes. The mice provide a novel animal model for cholestatic liver disease caused by TJP2-inactivating mutations in humans.
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| 2. |
- Chen, Jingjing, et al.
(författare)
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FishBuddy : Promoting Student Engagement in Self-Paced Learning through Wearable Sensing
- 2017
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Ingår i: 2017 IEEE INTERNATIONAL CONFERENCE ON SMART COMPUTING (SMARTCOMP). - : IEEE. - 9781509065172 ; , s. 211-219
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Konferensbidrag (refereegranskat)abstract
- Student engagement is crucial for successful self-paced learning. Feeling isolated during self-paced learning with neither adequate supervision nor intervention by teachers may cause negative emotions such as anxiety. Such emotions may in turn significantly weaken students' motivation to engage in learning activities. In this paper, we develop a self-paced learning environment (FishBuddy) that aims to reduce anxiety and promote student engagement. We construct and implement a physiologically-state-aware performance-evaluation model for identifying potentially fruitful moments of intervention when students show frustration during learning activities using an Apple Watch application that measures heart rate and alerts the student to watch a visualization of his or her own physiological state. We have conducted an experiment with 20 first-year undergraduate students, randomly separated into an experimental group and a control group, who carry out online, self-paced English grammar exercises. The students in the experimental group used FishBuddy and those in the control group did not. The self-reports from both groups show that FishBuddy significantly reduced reported experiences of anxiety and isolation in the experiment. Further to this, students who used FishBuddy were engaged longer with the exercises. The average scores on the exercises between the two groups, however, were not significantly different.
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| 3. |
- Liang, Wang, et al.
(författare)
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Life cycle assessment of blast furnace ironmaking processes : A comparison of fossil fuels and biomass hydrochar applications
- 2023
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 345
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Tidskriftsartikel (refereegranskat)abstract
- The impact of the iron and steel production process on the ecological environment cannot be ignored. This study aims to assess the impact of life cycle assessment on the traditional fossil fuel blast furnace ironmaking process and the biomass hydrochar blast furnace ironmaking process. The Simapro v9.0 software is used to comprehensively evaluate the life cycle impacts of biomass hydrochar in the blast furnace ironmaking process. The results show that the life cycle impact categories of the blast furnace ironmaking process mainly include global warming, non-renewable energy and respiratory inorganics. The global warming impact of the ironmaking process using hydrochar is 2054.00 kg CO2 eq, which is 420.61 kg CO2 eq less than that of traditional blast furnace ironmaking process. The global warming impact is mainly reflected in the emission of CO2 gas, and the main source is the generation of blast furnace gas and the use of sinter. The respiratory inorganics impact is mainly manifested in the emission of nitrogen oxides, sulfur oxides and particulates, which mainly comes from the mining of iron ore and the production of sinter. The non-renewable energy impact mainly comes from the coal resources, and the use of other renewable energy such as biomass energy is an important way to reduce the impact. Therefore, biomass hydrochar used in the metallurgical process is more suitable for sustainable devel-opment of the ecological environment.
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| 4. |
- Ren, Kaipeng, et al.
(författare)
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Bi-objective optimization of water management in shale gas exploration with uncertainty : A case study from Sichuan, China
- 2019
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Ingår i: Resources, Conservation and Recycling. - : ELSEVIER SCIENCE BV. - 0921-3449 .- 1879-0658. ; 143, s. 226-235
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Tidskriftsartikel (refereegranskat)abstract
- Shale gas exploration relies heavily on freshwater inputs while generating large amounts of wastewater. With the quick development of shale gas, water management during exploration has increasingly become a hotspot from both environmental and economic perspectives. This study investigated all the key water-consuming phases in exploration and optimized the freshwater use and flowback water control using a bi-objective programming model with the consideration of uncertainties in each phase, aiming at the optimal trade-offs between economic and environmental objectives. The model conducted a case study of shale gas projects in Sichuan, China. The results show that (a) Tolerance of the uncertainty in water demand for hydraulic fracturing can effectively reduce both economic and environment cost, thereby reducing total system cost. (b) System costs depends on risk preferences of decision-makers. (c) Direct reuse is the best strategy to treat wastewater at the early phase of hydraulic fracturing; while more constraints other than onsite treatment costs should be considered when treating produced water during the production phase. (d) There exists an "economics of scale" in the water management during shale gas exploration.
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| 5. |
- Song, Tengfei, et al.
(författare)
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Effect of carbonization conditions on the property and structure of bamboo char for injection in blast furnace
- 2019
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Ingår i: ISIJ International. - : Iron and Steel Institute of Japan. - 0915-1559 .- 1347-5460. ; 59:3, s. 442-449
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the effect of carbonization conditions on the bamboo, the relationship between carbonization parameter and physicochemical characteristics was studied. The results indicated that the volatile matter drastically decreased with the increase of carbonization temperature, while the fixed carbon and fuel ratio (fixed carbon/volatile matter) increased. Excellent linearity between the fuel ratio and carbonization temperature was obtained. The energy yield decreased gradually when rising the carbonization temperature, whereas the change of heating value was not obvious. A new calculation model of higher heating value (HHV) was developed, and it could be used to predict HHV of the bamboo char more precisely at temperatures above 300°C. The positive impact of functional groups, specific surface area as well as catalysis of alkali metal may contribute to the combustion of bamboo char. The results showed that there is a feasible operating condition for the transformation of bamboo into char with the carbonization parameter at 400°C for 30 min.
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| 6. |
- Wang, Jianliang, et al.
(författare)
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China's unconventional oil : A review of its resources and outlook for long-term production
- 2015
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 82:3, s. 31-42
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Forskningsöversikt (refereegranskat)abstract
- Due to the expected importance of unconventional oil in China's domestic oil supply, this paper first investigates the four types of China's unconventional oil resources comprehensively: heavy and extra-heavy oil, oil sands, broad tight oil and kerogen oil. Our results show that OIP (Oil-in-Place) of these four types of resources amount to 19.64 Gt, 5.97 Gt, 25.74 Gt and 47.64 Gt respectively, while TRRs (technically recoverable resources) amount to 2.24 Gt, 2.26 Gt, 6.95 Gt and 11.98 Gt respectively. Next, the Geologic Resources Supply-Demand Model is used to quantitatively project the long-term production of unconventional oil under two resource scenarios (TRR scenario and Proved Reserve + Cumulative Production scenario). Our results indicate that total unconventional oil production will peak in 2068 at 0.351 Gt in TRR scenario, whereas peak year and peak production of PR (proved reserves) + CP (Cumulative Production) scenario are 2023 and 0.048 Gt, significantly earlier and lower than those of TRR scenario. The implications of this growth in production of unconventional oil for China are also analyzed. The results show that if the TRR scenario can be achieved, it will increase total supply and improve oil security considerably. However, achieving the production in TRR scenario has many challenges, and even if it is achieved, China will still need to rely on imported oil.
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| 7. |
- Wang, Jianliang, et al.
(författare)
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The implications of fossil fuel supply constraints on climate change projections : A supply-side analysis
- 2017
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Ingår i: Futures. - : ELSEVIER SCI LTD. - 0016-3287 .- 1873-6378. ; 86, s. 58-72
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Tidskriftsartikel (refereegranskat)abstract
- Climate projections are based on emission scenarios. The emission scenarios used by the IPCC and by mainstream climate scientists are largely derived from the predicted demand for fossil fuels, and in our view take insufficient consideration of the constrained emissions that are likely due to the depletion of these fuels. This paper, by contrast, takes a supplyside view of CO2 emission, and generates two supply-driven emission scenarios based on a comprehensive investigation of likely long-term pathways of fossil fuel production drawn from peer-reviewed literature published since 2000. The potential rapid increases in the supply of the non-conventional fossil fuels are also investigated. Climate projections calculated in this paper indicate that the future atmospheric CO2 concentration will not exceed 610 ppm in this century; and that the increase in global surface temperature will be lower than 2.6 degrees C compared to pre-industrial level even if there is a significant increase in the production of non-conventional fossil fuels. Our results indicate therefore that the IPCC's climate projections overestimate the upper-bound of climate change. Furthermore, this paper shows that different production pathways of fossil fuels use, and different climate models, are the two main reasons for the significant differences in current literature on the topic.
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| 8. |
- Wang, Siyun, et al.
(författare)
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Environmental impacts from conventional and shale gas and oil development in China considering regional differences and well depth
- 2021
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Ingår i: Resources, Conservation and Recycling. - : Elsevier. - 0921-3449 .- 1879-0658. ; 167
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Tidskriftsartikel (refereegranskat)abstract
- China has stepped up its oil and gas development including unconventional resources as foreign dependence for oil and gas increased. Environmental impacts from the development phase has also caused widespread concern. To better understand environment impacts from current oil and gas development in China, a hybrid life cycle analysis (H-LCA) model was used to estimate the impact of six fields at the development stage based on data from 2017. The full environmental impact and full impact intensity (i.e., full environmental impact per unit of output by calorific value) of shale gas, conventional natural gas and oil development in China was compared and analyzed by eliminating well depth. Shale gas has 12.5% more environmental impact than conventional natural gas. Environmental impact of natural gas development is roughly 1.5 to 2 times that of conventional oil. Development of gas in Sichuan Basin have the greatest environmental impact, following southeast coast, Song Liao Basin, and Junggar Basin. However, the full impact intensity of shale gas development is more than five times that of conventional natural gas, but natural gas is still greener than conventional oil. The greatest full impact intensity is found in Junggar Basin, following Song Liao Basin and southeastern coast. From the comparison of full environmental impact and full impact intensity under per well depth, it's found that both of these are not positively correlated with reservoir depth and well depth even in the same basin. More attention should be paid to driving effects of specific reservoir developments and geological conditions.
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| 9. |
- Zhang, Hongguo, et al.
(författare)
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Cu-doped CaFeO3 perovskite oxide as oxygen reduction catalyst in air cathode microbial fuel cells
- 2022
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Ingår i: Environmental Research. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0013-9351 .- 1096-0953. ; 214
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Tidskriftsartikel (refereegranskat)abstract
- Cathode electrocatalyst is quite critical to realize the application of microbial fuel cells (MFCs). Perovskite oxides have been considered as potential MFCs cathode catalysts to replace Pt/C. Herein, Cu-doped perovskite oxide with a stable porous structure and excellent conductivity was successfully prepared through a sol-gel method. Due to the incorporation of Cu, CaFe0.9Cu0.1O3 has more micropores and a larger surface area, which are more conducive to contact with oxygen. Doping Cu resulted in more Fe3+ in B-site and thus enhanced its binding capability to oxygen molecules. The data from electrochemical test demonstrated that the as-prepared catalyst has good conductivity, high stability, and excellent ORR properties. Compared with Pt/C catalyst, CaFe0.9Cu0.1O3 exhibits a lower overpotential, which had an onset potential of 0.195 V and a half-wave potential of 0.224 V, respectively. CaFe0.9Cu0.1O3 displays an outstanding four-electron pathway for ORR mechanism and demonstrates superiors corrosion resistance and stability. The MFC with CaFe0.9Cu0.1O3 has a greater maximum power density (1090 mW m(-3)) rather than that of Pt/C cathode (970 mW m(-3)). This work demonstrated CaFe0.9Cu0.1O3 is an economic and efficient cathodic catalyst for MFCs.
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