| 1 | Antimicrobial peptide LL-37 forms complex with bacterial DNA to facilitate blood translocation of bacterial DNA and aggravate ulcerative colitis显示文摘Bacterial DNA(bacDNA) is frequently found in serum of patient with ulcerative colitis(UC) and Crohn's disease, even blood bacterial culture is negative. How bacDNA evades immune elimination and is translocated into blood remain unclear. Here, we showed that bacDNA avoids elimination and disables bacteriakilling function of antimicrobial peptide LL-37(Cramp in mice) by forming complex with LL-37, which is inducible after culture with bacteria or bacterial products. Elevated LL-37-bacDNA complex was found in plasma and lesions of patients with UC. LL-37-bacDNA promoted inflammation by inducing Th1, Th2 and Th17 differentiation and activating toll-like receptor-9(TLR9). The complex also increased paracellular permeability, which possibly combines its inflammatory effects to promote local damage and bacDNA translocation into blood. Cramp-bacDNA aggravated mouse colitis severity while interference with the complex ameliorated the disease. The study identifies that inflammatogenic bacDNA utilizes LL-37 as a vehicle for blood translocation and to evade immune elimination. Additionally, bacteria may make a milieu by releasing bacDNA to utilize and resist host antimicrobial peptides as a ‘trojan horse'. | Zilei Duan Yaqun Fang Yang Sun Ning Luan Xue Chen Mengrou Chen Yajun Han Yizhu Yin James Mwangi Junkun Niu Kunhua Wang Yinglei Miao Zhiye Zhang Ren Lai | 2018 | Science Bulletin2018，63，20： | 4 |
| 4 | Influence of reservoir construction on surrounding vegetation cover显示文摘Vegetation is a significant factor in the energy and water cycles.Changes in vegetation are affected by the natural environment and human activities.In this study,the Dalong Reservoir on the Ningyuan River in Sanya,Hainan,China,was taken as an example to set one type of buffer zone with the reservoir dam site as the center,and two types of horizontal and vertical buffer zones outwards from both banks of the river,and Landsat 5 remote sensing image data and the vegetation data were applied.A coverage estimation model was used to study the temporal and spatial changes in surface vegetation in three types of buffer zones,and the characteristics of the surface vegetation changes in the preterm,midterm and late-term reservoir construction periods were analyzed.The results showed that,(1)During the years 2000 and 2010,the vegetation coverage first decreased and then increased with time in the scope of the research.During preterm construction(2000-2004),the vegetation coverage in the upstream region decreased while that in the downstream region increased.During midterm construction(2004-2006),the declining rate of vegetation coverage downstream was greater than that upstream,but the influence of reservoir construction on vegetation coverage decreased over time in the late-term construction period(2007-2010);(2)Along the direction of the river length,the vegetation coverage showed a downtrend along with the river flow direction during the whole period(2000-2010),and the influence of reservoir construction on vegetation coverage gradually decreased as the distance from the reservoir increased;(3)Along the direction of the river width,the vegetation coverage in the preterm and midterm construction periods(2000-2006)increased with increasing distance from the riverbanks;(4)The vegetation coverage showed a significant increasing trend with increasing distance from the reservoir.The research results can provide a theoretical reference for reducing the risk of vegetation degradation,strengthening the governance of the ecological environment,and promoting the ecological construction of“landscapes,forests,fields,lakes and grass”. | Ping Liu Xinrui Li Ruikang Zhang Mengrou Yao Junfeng Chen Yanrong Li Xiangru Jia Yunfei Xing | 2021 | International Journal of Agricultural and Biological Engineering2021，14，3： | 0 |
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