100 research outputs found

    Myeloid cell-derived LL-37 promotes lung cancer growth by activating Wnt/β-catenin signaling

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    Rationale: Antimicrobial peptides, such as cathelicidin LL-37/hCAP-18, are important effectors of the innate immune system with direct antibacterial activity. In addition, LL-37 is involved in the regulation of tumor cell growth. However, the molecular mechanisms underlying the functions of LL-37 in promoting lung cancer are not fully understood. Methods: The expression of LL-37 in the tissues and sera of patients with non-small cell lung cancer was determined through immunohistological, immunofluorescence analysis, and enzyme-linked immunosorbent assay. The animal model of wild-type and Cramp knockout mice was employed to evaluate the tumorigenic effect of LL-37 in non-small cell lung cancer. The mechanism of LL-37 involving in the promotion of lung tumor growth was evaluated via microarray analyses, recombinant protein treatment approaches in vitro, tumor immunohistochemical assays, and intervention studies in vivo. Results: LL-37 produced by myeloid cells was frequently upregulated in primary human lung cancer tissues. Moreover, its expression level correlated with poor clinical outcome. LL-37 activated Wnt/β-catenin signaling by inducing the phosphorylation of protein kinase B and subsequent phosphorylation of glycogen synthase kinase 3β mediated by the toll-like receptor-4 expressed in lung tumor cells. LL-37 treatment of tumor cells also decreased the levels of Axin2. In contrast, it elevated those of an RNA-binding protein (tristetraprolin), which may be involved in the mechanism through which LL-37 induces activation of Wnt/β-catenin. Conclusion: LL-37 may be a critical molecular link between tumor-supportive immune cells and tumors, facilitating the progression of lung cancer

    Intermolecular coupling enhanced thermopower in single- molecule diketopyrrolopyrrole junctions

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    Sorting out organic molecules with high thermopower is essential for understanding molecular thermoelectrics. The intermolecular coupling offers a unique chance to enhance the thermopower by tuning the bandgap structure of molecular devices, but the investigation of intermolecular coupling in bulk materials remains challenging. Herein, we investigated the thermopower of diketopyrrolopyrrole (DPP) cored single-molecule junctions with different coupling strengths by varying the packing density of the self-assembled monolayers (SAM) using a customized scanning tunneling microscope break junction (STM-BJ) technique. We found that the thermopower of DPP molecules could be enhanced up to one order of magnitude with increasing packing density, suggesting that the thermopower increases with larger neighboring intermolecular interactions. The combined density functional theory (DFT) calculations revealed that the closely-packed configuration brings stronger intermolecular coupling and then reduces the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap, leading to an enhanced thermopower. Our findings offer a new strategy for developing organic thermoelectric devices with high thermopower

    An Improved Multi-Swarm Migrating Birds Optimization Algorithm for Hybrid Flow Shop Scheduling

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    An improved multi-swarm migrating birds optimization (IMMBO) algorithm is proposed for hybrid flow shop scheduling with sequence-dependent setup times (HFS-SDST), to minimize the total maximum completion time (i.e., makespan). Permutation-based encoding is adopted to substitute the individual. The modified Nawaz-Enscore-Ham (MNEH) algorithm is employed to generate initial population which are assigned to each sub-swarm according to the makespan. For each sub-swarm, the neighborhood individuals of the leader and followers are generated respectively by performing serial and parallel neighborhood strategies. If the follower is better than the leader according to their makespan, they are exchanged to ensure the information interaction of individuals within the sub-swarm. Moreover, the discrete whale optimization strategy is embedded in IMMBO to optimize the leaders of all sub-swarms to enhance the interaction among them. Furthermore, the local search is designed for the optimal individual to further improve the local search ability of the algorithm. Meanwhile, to avoid algorithm premature convergence, the control strategy for population diversification is designed to the leader of each sub-swarm. Finally, based on adjusting the algorithm parameters experimentally, simulation experiments are conducted on four variants of IMMBO to verify the function of each part by testing an adaptation dataset of Ta. Moreover, the IMMBO is compared with three existing algorithms by testing an adaptation dataset of Ta, and the experimental results demonstrate the effectiveness of the IMMBO algorithm to solve the hybrid flow shop scheduling problem

    Sustainable development and desertification control in Hotan region [Chinese language]

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    Abstract in EnglishIn order to speed up the step of shaking off poverty and building up a fortune of the 1.5 million population in Hotan region, a target of an increase of o. 33 ha farmland per capita will be realized during the "Ninth-five Plan" (1996~2000). It is estimated that a wasteland area of 6.67 X 104 ha will be reclaimed for planting cotton and fruit trees. This study focuses on the appraisal of the economic, ecological and environmental benefits of the project. The results show that it will need a big amount of investment to implement the project with a tight combination between wasteland reclamation, protection against wind, afforestation for sand -fixation, and construction of irrigation works, coordinative development of agriculture, forestry, and animal husbandry, and taking into a consideration of national, regional and local residents' benefits, while has the obvious benefits. Therefore, it is a feasible sustainable development scheme. It is suggested to do further research on the impact of the project on the environment of the lower reaches of Tarim River, and some privilege policies should be given to Hotan region by the state and autonomous region

    Research on the development mode of artificial ecology in Tarim Basin [Chinese language]

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    Abstract in EnglishThe ecological environment in the oases in Tarim Basin becomes more deteriorative since recent 2000 years, especially since recent 100 years due to the over exploitation and utilization of natural resources. In this paper, a comparative analysis between artificial ecology and natural ecology on the aspects of consumption of water resources, effectivity of ecological and environmental protection, management expenses and output benefits is carried out based on the experiences of the oases' construction in Tarim Basin. The results show that the high - benefit artificial ecology is more effective for ecological protection than the low-output natural ecology. Taking the ecological environment in the area on the southern bank of Tarim River in Xayar County as an example, a dynamic input-output analysis is made for the program of forestry construction and land exploitation in the southern part of Tarim Basin, the paper also analyzes the impact of the construction of irrigation works, soil improvement, and implementation of the measures for protecting against wind and fixing sand upon agricultural production. The calculation results show clearly that the artificial ecological construction and land exploitation can be coordinatedly developed. An ecological agriculture with the high quality and high yield will be able to be reached by the way of spiral growth mode with low-input, high-output and re-input so as to achieve a tight connection between the construction of irrigation works, soil improvement, protection against wind and sand fixation, and provide a new way for reforming the traditional agriculture, protecting ecological environment, and realizing a sustainable development

    From non-market support to cost-competitive incentives: Wind energy commercialization in China

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    This paper presents an overview of the development of wind energy in China. By examining the economics of windfarm development, it compares the economics of wind technology with other conventional energy technologies and analyzes the role of alternative policy instruments. Meanwhile, it identifies the major constraints of wind technology development and the defects of current non-market support from the government. It shows that the development of wind power will be directly subject to rational policy change, incentive mechanisms and institutional framework building. Particular importance is paid to market incentives to reach the objectives of commercialization and industrialization of wind power. The paper recommends some cost-competitive incentive measures and policies to drive the wind power market. It concludes that promising market incentives to speed up the development of wind energy include: (i) establish market competition mechanisms through standard power purchase agreement; (ii) adjust tax policies and government subsidies; (iii) stimulate investment incentive policies and regulations; and (iv) change governmental institutions and management modes

    Intra-annual land cover mapping and dynamics analysis with dense satellite image time series: a spatiotemporal cube based spatiotemporal contextual method

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    Land covers provide essential information for understanding and detecting ecosystem, resources, and environmental dynamics. However, they are generally mapped at coarser temporal scales to study the inter-annual changes, while scant attention has been paid to map intra-annual land cover dynamics at finer temporal scales. Moreover, existing studies are still limited in intra-annual land cover mapping with dense satellite image time series (SITS). Accordingly, this study proposed a novel approach to accurately classify dense SITS for mapping intra-annual land cover dynamics. First, dense SITS is segmented at multiple spatiotemporal scales to generate optimal spatiotemporal cubes (ST-cubes), which are chosen as classification units. Second, the ST-cubes based on spectral, textural, spatial, and temporal features are integratively defined and employed in SITS classification. Third, the spatiotemporal context is modeled by a spatiotemporally extended conditional random field model that measures both spatiotemporal features and semantic correlation between geographic objects. Finally, the proposed method is applied to map the intra-annual land cover dynamics. Comparative experiments of SITS classification are carried out between our method and three existing competitors in a suburban area in Beijing, China, with a dense Sentinel-2 SITS. Moreover, based on the classification results, we analyzed the quantitative intra-annual dynamics of land cover. The result shows that our approach achieves significant improvements in classification accuracy over existing methods, indicating the effectiveness and superiority of the proposed method in mapping intra-annual land cover dynamics with dense SITS

    Novel Amino-Pyridine Functionalized Chitosan Quaternary Ammonium Derivatives: Design, Synthesis, and Antioxidant Activity

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    Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activity of chitosan derivatives. The chitosan derivatives’ antioxidant activity against hydroxyl-radical and 1,1-Diphenyl-2-picrylhydrazyl (DPPH)-radical was tested in vitro. The results showed that chitosan derivatives had better water solubility and stronger antioxidant activity compared with chitosan in all assays. Especially, compounds 3C and 3E (with 3-amino pyridine and 2,3-diamino pyridine as substitute respectively) exhibited stronger hydroxyl-radical and DPPH-radical scavenging ability than other synthesized compounds. These data demonstrated that the synergistic effect of the amino group and pyridine would improve the antioxidant activity of chitosan derivatives, and the position of the amino group on pyridine could influence the antioxidant property of chitosan derivatives
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