265 research outputs found

    Microscopic insights to spin transport–driven ultrafast magnetization dynamics in a Gd/Fe bilayer

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    Laser-induced spin transport is a key ingredient in ultrafast spin dynamics. However, it remains debated to what extent ultrafast magnetization dynamics generates spin currents and vice versa. We use time- and spin-resolved photoemission spectroscopy to study an antiferromagnetically coupled Gd/Fe bilayer, a prototype system for all-optical switching. Spin transport leads to an ultrafast drop of the spin polarization at the Gd surface, demonstrating angular-momentum transfer over several nanometers. Thereby, Fe acts as spin filter, absorbing spin majority but reflecting spin minority electrons. Spin transport from Gd to Fe was corroborated by an ultrafast increase of the Fe spin polarization in a reversed Fe/Gd bilayer. In contrast, for a pure Gd film, spin transport into the tungsten substrate can be neglected, as spin polarization stays constant. Our results suggest that ultrafast spin transport drives the magnetization dynamics in Gd/Fe and reveal microscopic insights into ultrafast spin dynamics

    Looking Forward to Seeing Real Experiences through Photos? It Depends on the Quality of Photos

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    We investigated whether the quality of photos will exert an influence on the post-evaluation of the experience? Through two experiments, we found that the effect does exist. When people reactivate memories through photos, photos can work in the following ways. First, photos can make the memory related to photo content more prominent. Secondly, photos content can replace the already obscured original memory to a certain extent. When the quality of photos is high, people tend to accept the memory being reprocessed, driven by photos, thus improving the evaluation of the original experience. When the quality of the photos is low, people subconsciously reject the information that photos convey and still insist on the judgment of the original experience. The above scenarios apply when people still have an initial impression on their experiences

    Decoupling of economic growth from CO<sub>2</sub> emissions in Yangtze River Economic Belt cities

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    Cities play significant roles in mitigating global climate change and formulating low carbon roadmaps. As the first regional strategy that prioritizes green development, the Yangtze River Economic Belt (YREB) is an economic circle along the Yangtze River, stringing up 11 provinces and municipalities from west to east of China. The huge regional heterogeneity in terms of economic development, size, and structure in YREB cities need differentiated emission reduction strategies and low-carbon development pathways. This study compiled the CO2 emission inventories of 85 cities in the YREB for the first time and explored the decoupling of economic growth from CO2 emissions at the city level. The results show that CO2 emissions of YREB cities increased at an annual average rate of 5.1% from 2005 to 2017, and 85 YREB cities emitted 44% of national total CO2 emissions and contributed 41% of national GDP in 2017. 61% of cities dominated by high-tech and service industry achieved decoupling between economic development and emissions before 2009 and are moving forward to a stronger decoupling state. 25% of cities achieved decoupling after 2009 and these post-decoupling cities took the heavy industry and light industry as their leading industries. Resource-based cities with slow economic development and high CO2 emissions changed from decoupling to negative decoupling or coupling. The proposed differentiated low-carbon development pathways for YREB cities could provide references for cities at different stages to achieve decoupling of GDP from CO2 emissions and emission reduction goals

    CO<sub>2</sub> emission reduction potential in China from combined effects of structural adjustment of economy and efficiency improvement

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    China has committed to decreasing its emission intensity by 60% to 65% by 2030 compared to 2005 levels and achieving carbon neutrality by 2060. It is of great importance to evaluate the CO2 emission reduction potential to quantify the amount of CO2 emissions that can be less generated and the amount that should be balanced out. Economic structure adjustment and CO2 emission efficiency improvement will contribute to mitigating CO2 emissions, which always happen simultaneously in the real world. However, few studies consider these issues simultaneously, which can lead to inaccurate estimation. A scenario analysis framework is proposed to estimate their combined effects, and an indicator is proposed to measure the technical feasibility of achieving the reduction potential. A set of scenarios are designed based on this framework and we find that: (1) to achieve carbon neutrality, 6161.16 Mt of CO2 emissions of China can be less generated compared to 2017 levels by significantly increasing its tertiary industry share to high-income entities’ level and adopting the most advanced technology to improve emission efficiency; the remaining 2732.40 Mt of CO2 emissions should be removed by carbon offsetting. Regarding emission intensity, 81.39% can be reduced compared with the 2005 level; and (2) Technical feasibility analysis shows Sichuan, Chongqing, and Anhui have the largest technical barriers in achieving the reduction potential. The proposed scenario analysis framework can provide a reference not only for China to achieve the emission mitigation pledges, but for countries with significant technological differences and structure adjustment to formulate mitigation strategies.</p

    Melatonin enhances the anti-tumor effect of fisetin by inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways.

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    Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy

    Cyprinus carpio Decoction Improves Nutrition and Immunity and Reduces Proteinuria through Nephrin and CD2AP Expressions in Rats with Adriamycin-Induced Nephropathy

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    Cyprinus carpio decoction (CCD) is a well-known Chinese food medicine formula, accepted widely as a useful therapy in preventing edema and proteinuria caused by renal disease. However, the mechanism underlying this effect remains unclear. The current study investigated the potential mechanism of CCD in alleviating nephropathy induced by adriamycin (ADR) in rats. 70  eight-week-old Wistar rats were randomly divided into normal, model, fosinopril, YD, YG groups. All rats except for the normal group received 6.5 mg/kg·bw of ADR injection into the vena caudalis once. Different doses of CCD (11.3 and 22.5 g kg−1) were lavaged to rats in YD and YG groups, respectively. Then the serum biochemical values of the total protein (TP), albumin (ALB), blood urea nitrogen (BUN), creatinine (Cr), electrolyte levels, and the urinary protein (UP) content in 12 hr urine were measured. Interleukin-4 (IL-4) and interferon (INF-γ) were measured by enzyme-like immunosorbent assay (ELISA). The pathomorphological analysis was observed using light and electron microscopy, and the expressions of nephrin and CD2-associated protein (CD2AP) in renal tissues were determined by immunohistochemical assay. The results indicated that CCD can relieve ADR-induced nephropathy (ADN) by improving the nutrition status, regulating the immunity, and inhibiting proteinuria by increasing nephrin and CD2AP expressions

    Comparisons of CO<sub>2</sub> emission performance between secondary and service industries in Yangtze River Delta cities

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    To put the brakes on global climate change, China, the world's top emitter, has established ambitious CO2 emissions reduction targets. Industry-level emissions analysis can help policymakers determine better ways to achieve mitigation targets. This study is the first to target the total-factor carbon emission performance (TCPI) of secondary and service industries. We first compile industry-level CO2 emission inventories of 25 Yangtze River Delta cities during 2007–2016. The TCPI of secondary and service industries is then estimated by the non-radial directional distance function. We then compare the TCPI of the two industries across levels, dynamics, and inequalities using a global metafrontier approach. The results show the TCPI of the service industry (0.563 in 2016) was significantly higher than that of secondary industry (0.256 in 2016), suggesting that the service industry was more carbon-friendly. The TCPI gap between the secondary and service industries narrowed over the study period. The TCPI of secondary industry showed a promising increase during 2007–2016 with an annual growth rate of 2.30%, reflecting the positive effects of the government's reforms and environmental regulations. By contrast, the service industry saw a downward trend in TCPI, decreasing by 1.68% annually, primarily because it is a newcomer to low-carbon development. TCPI inequality in secondary industry was much larger than in the service industry, suggesting that significant heterogeneity exists in secondary industry. Therefore, policymakers should implement targeted mitigation policies for secondary industry, and place decarbonising the service industry on the agenda to reverse its decreasing TCPI

    The governance-production nexus of eco-efficiency in Chinese resource-based cities:A two-stage network DEA approach

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    For decades, resource-based cities in China have significantly contributed to China's socio-economic development. The heavy resource dependence of resource-based cities inevitably leads to a series of environmental problems. Mitigating environmental impacts in an unthinking manner might be disruptive for economic development. Improving eco-efficiency has been a crucial solution for protecting the environment while mitigating its negative economic impact. However, the method commonly used to evaluate the eco-efficiency – that is, the black-box data envelopment analysis (DEA) – cannot examine the inefficiencies of the internal structure, and as a result, the underlying management defects are unclear. To open the black box, this study presents a two-stage network DEA framework incorporating government and industrial sectors and measures the eco-efficiency of 84 resource-based cities during the post-financial crisis period (2007–2015). The results indicate that the average eco-efficiency of China's resource-based cities shows a promising increase, and there is a positive relationship between governance efficiency and production efficiency. The decreasing trend of governance efficiency in the Central, Western, and Northeast regions after 2014 shows the low quality of the government sector in the usage of fiscal income. Proactive disclosure of how the government sector conducts public business and spends taxpayers' money should be made to increase transparency, attract more entrepreneurial resources to carry out production activities, and further improve sustainability. The two-stage network DEA framework helps obtain more insights into the internal management defects of the government and industrial sectors and enhance their cooperation to improve the eco-efficiency precisely

    CO2 emission patterns in shrinking and growing cities:A case study of Northeast China and the Yangtze River Delta

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    The implementation of CO2 emission mitigation policies in cities is the key to China achieving its national emission mitigation targets. China is experiencing rapid urbanization and facing huge inequality in regional development and then shrinking cities generate. This study, for the first time, discusses long-term CO2 emission patterns of shrinking cities with comparisons of growing cities. 55 cities in Northeast China and the Yangtze River Delta are selected as cases. We first categorize these cities into three groups of shrinking cities and three groups of growing cities with a population index. Each group's emission patterns in terms of energy, employment and industry structures are then examined. We find that CO2 emissions in the rapidly shrinking group presented a continuously increasing trend, while the other five groups reached their emission peaks in 2011-2013. For slightly and moderately shrinking groups, CO2 emission mitigation was a positive sign but occurred with the decline of secondary industry, especially for resource-based or heavy manufacturing cities, such as Daqing and Anshan in Northeast China. In the case of three types of growing cities, cities were capable of mitigating CO2 emissions and maintaining economic growth. The slightly growing group was the optimal type among these six groups. Its CO2 emissions experienced a decline with an annual rate of -1.47% during 2013-2015, while the economy still soared (increased by 7.27% annually). New economic growth points should be fostered to mitigate further shrinkage and achieve sustainable development for shrinking cities. The cities' categorization rules, research thinking, and results offered in this study could provide a reference for other cities or developing countries at similar industrialization/urbanization phases to abbreviate their path towards a low-carbon economy
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