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食用蔬菜能吸收和积累微塑料 期刊论文
科学通报, 2019, 卷号: 64, 期号: 9, 页码: 928-934
作者:  李连祯;  周倩;  尹娜;  涂晨;  骆永明
收藏  |  浏览/下载：63/0  |  提交时间：2020/06/17
微塑料  生菜  聚苯乙烯微球  吸收  积累  健康风险  microplastics  lettuce  polystyrene microbeads  uptake  accumulation  human health risk  Microplastic (MP, 100 nm-5 mm) may present an attributable risk to ecosystem and human health, and its pollution has become a global environmental concern. Despite a wealth of information on the accumulation of MPs in aquatic species, there is no information on the uptake and accumulation of MPs by higher plants. Terrestrial edible plants are directly exposed to MPs when agricultural soil was applied with organic manure, sewage sludge as fertilizer or plastic mulching. In this paper, the uptake of two sizes of polystyrene (PS) microbeads (0.2 and 1.0 mum) and then their distribution and migration in an edible plant lettuce were firstly investigated based on laboratory experiments. We used fluorescent markers to track PS microbeads in plant tissues and found fluorescence to be a sensitive and reliable detection method. Sections from untreated control lettuce showed no autofluorescence. When roots were treated with fluorescently labeled PS microbeads, the microbeads could be identified by its fluorescence. Our main study investigated the uptake of 0.2 mum beads, as few luminescence signals were observed in lettuce roots for 1.0 mum beads in our experiment. We observed that 0.2 mum fluorescent microbeads were extracellularly trapped in the root cap mucilage (which is a highly hydrated polysaccharide) and a dark green tip (which was typical of lettuce roots exposed to label PS beads) was usually visible to the naked eye. Confocal images revealed that the PS luminescence signals were mainly located in the vascular system and on the cell walls of the cortex tissue of the roots, indicated that the beads passed through the intercellular space via the apoplastic transport system. Once inside the central cylinder, the 0.2 mum PS beads were transferred from the roots to the stems and leaves via the vascular system following the transpiration stream. We also observed that the PS beads adhered to one another and self-assembled systematically into grape-like and (chain) string-like clusters in the intercellular space of the root and stem vascular tissue of lettuce plant. In contrast to the root and stem, PS beads were dispersed in the leaf tissue. Here, for the first time we provide evidence of the adherence, uptake, accumulation, and translocation of submicrometer MPs within an edible plant. Our findings highlight the previously underappreciated human exposure pathway to MPs through the consumption of contaminated crops and emphasize the need for new management strategies to control the release of MPs waste products into the terrestrial environment. Ultimately, the potential impacts of low range sized MPs on food safety of crop plants and human health need to be urgently considered.  
An analysis of first-time and repeat visitors to Korean national parks from 2007 and 2013 期刊论文
Journal of Mountain Science, 2017, 卷号: 14, 期号: 12, 页码: 2527-2539
作者:  Yunseon CHOE;  Michael A. SCHUETT;  Kyu-Won SIM
收藏  |  浏览/下载：123/0  |  提交时间：2017/12/07
ThIs Paper ExamIned VIsiTors To Bukhansan NatiOnal Park In Korea Based On First-time And Repeat vIsitatiOn. Bukhansan NatiOnal Park Is Korea's Most Heavily vIsited NatiOnal Park With Annual vIsitatiOn Of Six milliOn VIsiTors In 2015. Data Used In ThIs Article Were Collected On-site In The Park In 2007 And 2013 By The Korea NatiOnal Park Service (Knps). The Study Variables Included Socio-demographics  Travel Behavior  Motivation  And Satisfaction With Park Attributes  Services And Facilities. Data Were Analyzed By Each Study Year For First-time And Repeat Visitors. Results Showed Significant Differences For Both First-time And Repeat Visitors.On Several Socio-demographic  Travel Behavior  And Motivation Variables Within Each Study Year. For Satisfaction With Park Attributes  Facilities And Services  First-time VisiTors Were Significantly Different From Repeat VisiTors On Seven Variables For Both Years. implicatiOns Are Given Regarding Programs And Services To Improve visiTor satisfactiOn And Sustain The Natural  Cultural And HisTorical Resources At Bukhansan nAtional Park And Other nAtional Parks In Korea. Future Research Suggestions Are Provided To Learn More About visiTor Characteristics  StAndards Of Quality And Preferences In The National Parks.  
Quantitative analysis of COLREG rules and seamanship for autonomous collision avoidance at open sea 期刊论文
Ocean Engineering, 2017, 卷号: 140, 页码: 281-291
作者:  He, Yixiong;  Jin, Yi;  Huang, Liwen;  Xiong, Yong;  Chen, Pengfei
收藏  |  浏览/下载：5/0  |  提交时间：2019/12/04
ACA  automatic collision avoidance  CA  collision avoidance  COLREG  International Regulations for Preventing Collisions at Sea 1972  CPA  closest point of approach  CR  risk of collision  CS  close-quarters situation  DCPA  distance to the closest point of approach  FTCS  first time-in-point of close-quarters situation  FTID  first time-in-point of immediate danger  ID  immediate danger  MMG  mathematical modeling group  OS  own ship  PCR  potential risk of collision  RPM  Revolutions Per Minute  SD  ship domain  TCPA  time to the closest point of approach  TCS  time to close-quarters situation  TID  time to immediate danger  TS  target ship  Quantitative analysis  COLREG rules and Seamanship  Modeling  Navigation  Autonomous collision avoidance  
Structural time-dependent reliability assessment of the vibration active control system with unknown-but-bounded uncertainties 期刊论文
STRUCTURAL CONTROL & HEALTH MONITORING, 2017, 卷号: 24
作者:  Wang, Lei;  Wang, Xiaojun;  Li, Yunlong;  Lin, Guiping;  Qiu, Zhiping
收藏  |  浏览/下载：4/0  |  提交时间：2019/12/30
早产儿视网膜病变的筛查策略探讨 期刊论文
2012
熊永强; 刘生荣; 陈立宇; 廖宝兰; 吕月娥; 陈美玲; 林新祝
收藏  |  浏览/下载：5/0  |  提交时间：2016/05/17
Seroprevalence of Chlamydophila infection in chickens, ducks, geese and pigeons in Southern China 期刊论文
AFRICAN JOURNAL OF MICROBIOLOGY RESEARCH, 2011, 卷号: 5, 期号: 24, 页码: 4240-4242
作者:  Lin, R. Q.;  Wang, X. Q.;  Yan, C.;  He, X. H.;  Cheng, T.
收藏  |  浏览/下载：5/0  |  提交时间：2019/12/23
Chlamydophila psittaci is widely distributed in a number of birds and humans throughout the world  but little is known of the prevalence of C. psittaci in birds in China. In the present study  sera from 240 chickens  200 ducks  200 geese and 200 pigeons in China’s southern Guangdong Province were assayed for Chlamydophila antibodies by indirect hemagglutination assay (IHA). The specific antibodies were found in sera of 17.92% of 240 chickens  6% of 200 ducks  22% of 200 geese and 17% of 200 pigeons. Statistical analysis showed that the seroprevalence of C. psittaci in ducks was significantly lower than that in chickens  geese and pigeons  respectively (P < 0.05). The seroprevalence in free-range chickens was 10.83%  and it was 25% in caged chickens  and the difference was statistically significant (P < 0.05). Among different age groups of pigeons  the difference in seroprevalence of C. psittaci between adult pigeons and adolescent pigeons was significant (P < 0.05). This is the first time that the seroprevalence of Chlamydophila infection in domestic birds in Southern China was reported  and the data showed that the prevalence of Chlamydophila infection in domestic birds is high  indicating that the domestic birds may be an important source for human infection by C. psittaci in Southern China.  

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