Eupatorium adenophorum Spreng. was introduced in Yunnan Province of China around 1940. Since then it has been spreading rapidly, particularly in the southern and southwestern parts of China and caused serious economic...Eupatorium adenophorum Spreng. was introduced in Yunnan Province of China around 1940. Since then it has been spreading rapidly, particularly in the southern and southwestern parts of China and caused serious economic loss. The biological research and inte-grated control on E. adenophorum were carried out from 1980's in Yunnan Province. Together with other 15 invasive external species, the weed has been listed in the White Paper by The State Environmental Protection Administration of China. This paper briefly reviews the studies on natural distribution, biological character, ecological character, chemical component, hazard, potential application and the control of E. adenophorum. The research direction for this invasive external species in future was also discussed.展开更多
AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutiv...AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size： small （≤10 ram） and large （〉10 ram）. Clinicopathological features, incidence of lymph node metastasis （LNM） and risk factors for LNM, such as depth of invasion, lymphovascular invasion （LVI） and poorly differentiated adenocarcinoma （PDA） were analyzed in all resected specimens. RESULTS： There were 120 （21%） small and 463 （79%） large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer （sin： 1〉1000 μm） in 90 （75%） cases, LVI in 26 （22%） cases, and PDA in 12 （10%） cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 （82%） cases, LVI in 125 （27%） cases, and PDA in 79 （17%） cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION： Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.展开更多
Applying randomly amplified polymorphic DNA (RAPD), the genetic variation of Cabomba caro- liniana Gray (cabomba or fanwort), a new alien plant in China, was analyzed in this paper. Total 143 bands, in- cluding 47 pol...Applying randomly amplified polymorphic DNA (RAPD), the genetic variation of Cabomba caro- liniana Gray (cabomba or fanwort), a new alien plant in China, was analyzed in this paper. Total 143 bands, in- cluding 47 polymorphic bands, were amplified from 23 primers in 20 samples. The sampling distance was large, but its genetic diversity was low. The main results were that: (1) Cabomba, which grew and dispersed mainly in fragment, was an abundant and dominant species in freshwater, and its main dispersal mechanism was vegetative reproduction. (2) Cabomba was originally introduced into China as an aquarium submerged plant. Somehow, those discarded cabomba became invasive species in the areas of Hangzhou, Shanghai, and Meicheng, and other places. (3) Although the level of genetic diversity in cabomba was low, their rapid dispersion and propagation could seriously harm to local aquatic community. Therefore, specific measure should be used to control cabomba from uncontrolled spreading and damage to local vegetation communities.展开更多
Single-element combustor experiments are conducted for three shear coaxial geometry configuration injectors by using gaseous oxygen and gaseous hydrogen(GO2/GH2) as propellants. During the combustion process, several ...Single-element combustor experiments are conducted for three shear coaxial geometry configuration injectors by using gaseous oxygen and gaseous hydrogen(GO2/GH2) as propellants. During the combustion process, several spatially and time- resolved non-intrusive optical techniques, such as OH planar laser induced fluorescence(PLIF), high speed imaging, and infrared imaging, are simultaneously employed to observe the OH radical concentration distribution, flame fluctuations, and temperature fields. The results demonstrate that the turbulent flow phenomenon of non-premixed flame exhibits a remarkable periodicity, and the mixing ratio becomes a crucial factor to influence the combustion flame length. The high speed and infrared images have a consistent temperature field trend. As for the OH-PLIF images, an intuitionistic local flame structure is revealed by single-shot instantaneous images. Furthermore, the means and standard deviations of OH radical intensity are acquired to provide statistical information regarding the flame, which may be helpful for validation of numerical simulations in future. Parameters of structure configurations, such as impinging angle and oxygen post thickness, play an important role in the reaction zone distribution. Based on a successful flame contour extraction method assembled with non-linear anisotropic diffusive filtering and variational level-set, it is possible to implement a fractal analysis to describe the fractal characteristics of the non-premixed flame contour. As a result, the flame front cannot be regarded as a fractal object. However, this turbulent process presents a self-similarity characteristic.展开更多
Aims Among terrestrial ecosystems,coastal sandy dunes are particularly prone to alien plant invasion.Many studies related the invasion of dune habitats to anthropic causes,but less is known about the role of soil prop...Aims Among terrestrial ecosystems,coastal sandy dunes are particularly prone to alien plant invasion.Many studies related the invasion of dune habitats to anthropic causes,but less is known about the role of soil properties and plant traits in plant invasion.In this study,we tested the relationships between soil features and alien plant invasion in dune systems,focusing on the interplay between soil nutrients,soil salinity and plant functional traits.Methods Study sites were sandy barrier islands of the Marano and Grado lagoon(northern Adriatic Sea).One hundred plots(4 m×4 m)were selected within 10 areas according to the main habitats occurring along the ecological gradient of dune system(foredune,backdune and saltmarsh).In each plot,we recorded all plant species occurrence and abundance and we collected a soil core.For each soil sample,soil texture,conductivity(as proxy of soil salinity),organic carbon and nitrogen content were analyzed and related to the species number and cover of native and alien plants.Variation of main reproductive and vegetative functional traits among habitats was also analyzed for both alien and native species.Important Findings Soil properties were strongly related to overall plant diversity,by differently affecting alien and native species pools.In backdune,the most invaded habitat,a high soil conductivity limited the number of alien species,whereas the content of soil organic carbon increased along with alien plant abundance,suggesting also the occurrence of potential feedback processes between plant invasion and soil.We found a significant convergence between native and alien plant functional trait spectra only in backdune habitat,where environmental conditions ameliorate and plant competition increases.Our findings suggest that in harsh conditions only native specialized plants can thrive while at intermediate conditions,soil properties gradient acts in synergy with plant traits to curb/facilitate alien plant richness.展开更多
Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment...Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment on exotic plant invasions are associated with its effects on root-AMF symbiosis of invasive and native plants.To address this issue,the annual invasive plant Xanthium strumarium and two phylogenetically related annual natives were compared under ambient and elevated CO_(2)concentrations for three consecutive years.Atmospheric CO_(2)enrichment increased AMF colonization rates for the species only in few cases,and the invader did not benefit more from CO_(2)enrichment in terms of AMF colonization.Under ambient CO_(2)concentration,however,the invader had a higher AMF colonization rate than the natives in the first year of the study,which disappeared in the second and third year of the study due to the increase of AMF colonization rates in the natives but not in the invader.The influences of species,CO_(2)concentrations and planting year on AMF colonization were associated with their effects on both soil nutrient and AMF community,and the former may be more important as it also influenced the latter.Our results indicate that the invader could more quickly form symbiosis with soil AMF,contributing to adaptation and occupation of new habitats,and that it is necessary to consider the roles of AMF and the effects of time when determining the effects of global changes such as atmospheric CO_(2)enrichment on exotic plant invasions.展开更多
基金This study was supported by Project of Chinese Academy of Science Knowledge Innovation Program (KSCX1-SW-13-0X-0X) and National Natural Science Foundation of China (30470337)
文摘Eupatorium adenophorum Spreng. was introduced in Yunnan Province of China around 1940. Since then it has been spreading rapidly, particularly in the southern and southwestern parts of China and caused serious economic loss. The biological research and inte-grated control on E. adenophorum were carried out from 1980's in Yunnan Province. Together with other 15 invasive external species, the weed has been listed in the White Paper by The State Environmental Protection Administration of China. This paper briefly reviews the studies on natural distribution, biological character, ecological character, chemical component, hazard, potential application and the control of E. adenophorum. The research direction for this invasive external species in future was also discussed.
文摘AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size： small （≤10 ram） and large （〉10 ram）. Clinicopathological features, incidence of lymph node metastasis （LNM） and risk factors for LNM, such as depth of invasion, lymphovascular invasion （LVI） and poorly differentiated adenocarcinoma （PDA） were analyzed in all resected specimens. RESULTS： There were 120 （21%） small and 463 （79%） large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer （sin： 1〉1000 μm） in 90 （75%） cases, LVI in 26 （22%） cases, and PDA in 12 （10%） cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 （82%） cases, LVI in 125 （27%） cases, and PDA in 79 （17%） cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION： Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.
基金Supported by National Natural Science Foundation of China (No.39970145) and Major State Basic Research Development Program ofChina (No. G2000046803)
文摘Applying randomly amplified polymorphic DNA (RAPD), the genetic variation of Cabomba caro- liniana Gray (cabomba or fanwort), a new alien plant in China, was analyzed in this paper. Total 143 bands, in- cluding 47 polymorphic bands, were amplified from 23 primers in 20 samples. The sampling distance was large, but its genetic diversity was low. The main results were that: (1) Cabomba, which grew and dispersed mainly in fragment, was an abundant and dominant species in freshwater, and its main dispersal mechanism was vegetative reproduction. (2) Cabomba was originally introduced into China as an aquarium submerged plant. Somehow, those discarded cabomba became invasive species in the areas of Hangzhou, Shanghai, and Meicheng, and other places. (3) Although the level of genetic diversity in cabomba was low, their rapid dispersion and propagation could seriously harm to local aquatic community. Therefore, specific measure should be used to control cabomba from uncontrolled spreading and damage to local vegetation communities.
文摘Single-element combustor experiments are conducted for three shear coaxial geometry configuration injectors by using gaseous oxygen and gaseous hydrogen(GO2/GH2) as propellants. During the combustion process, several spatially and time- resolved non-intrusive optical techniques, such as OH planar laser induced fluorescence(PLIF), high speed imaging, and infrared imaging, are simultaneously employed to observe the OH radical concentration distribution, flame fluctuations, and temperature fields. The results demonstrate that the turbulent flow phenomenon of non-premixed flame exhibits a remarkable periodicity, and the mixing ratio becomes a crucial factor to influence the combustion flame length. The high speed and infrared images have a consistent temperature field trend. As for the OH-PLIF images, an intuitionistic local flame structure is revealed by single-shot instantaneous images. Furthermore, the means and standard deviations of OH radical intensity are acquired to provide statistical information regarding the flame, which may be helpful for validation of numerical simulations in future. Parameters of structure configurations, such as impinging angle and oxygen post thickness, play an important role in the reaction zone distribution. Based on a successful flame contour extraction method assembled with non-linear anisotropic diffusive filtering and variational level-set, it is possible to implement a fractal analysis to describe the fractal characteristics of the non-premixed flame contour. As a result, the flame front cannot be regarded as a fractal object. However, this turbulent process presents a self-similarity characteristic.
基金supported by Regione Autonoma Friuli Venezia Giulia and University of Udine(grant number Morphological and environmental study of the Marano and Grado Lagoon CUP D26D14000230002).
文摘Aims Among terrestrial ecosystems,coastal sandy dunes are particularly prone to alien plant invasion.Many studies related the invasion of dune habitats to anthropic causes,but less is known about the role of soil properties and plant traits in plant invasion.In this study,we tested the relationships between soil features and alien plant invasion in dune systems,focusing on the interplay between soil nutrients,soil salinity and plant functional traits.Methods Study sites were sandy barrier islands of the Marano and Grado lagoon(northern Adriatic Sea).One hundred plots(4 m×4 m)were selected within 10 areas according to the main habitats occurring along the ecological gradient of dune system(foredune,backdune and saltmarsh).In each plot,we recorded all plant species occurrence and abundance and we collected a soil core.For each soil sample,soil texture,conductivity(as proxy of soil salinity),organic carbon and nitrogen content were analyzed and related to the species number and cover of native and alien plants.Variation of main reproductive and vegetative functional traits among habitats was also analyzed for both alien and native species.Important Findings Soil properties were strongly related to overall plant diversity,by differently affecting alien and native species pools.In backdune,the most invaded habitat,a high soil conductivity limited the number of alien species,whereas the content of soil organic carbon increased along with alien plant abundance,suggesting also the occurrence of potential feedback processes between plant invasion and soil.We found a significant convergence between native and alien plant functional trait spectra only in backdune habitat,where environmental conditions ameliorate and plant competition increases.Our findings suggest that in harsh conditions only native specialized plants can thrive while at intermediate conditions,soil properties gradient acts in synergy with plant traits to curb/facilitate alien plant richness.
基金supported by the National Natural Science Foundation of China(31971557,31670545 and 31470575)the National Key R&D Program of China(2017YFC1200101).
文摘Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment on exotic plant invasions are associated with its effects on root-AMF symbiosis of invasive and native plants.To address this issue,the annual invasive plant Xanthium strumarium and two phylogenetically related annual natives were compared under ambient and elevated CO_(2)concentrations for three consecutive years.Atmospheric CO_(2)enrichment increased AMF colonization rates for the species only in few cases,and the invader did not benefit more from CO_(2)enrichment in terms of AMF colonization.Under ambient CO_(2)concentration,however,the invader had a higher AMF colonization rate than the natives in the first year of the study,which disappeared in the second and third year of the study due to the increase of AMF colonization rates in the natives but not in the invader.The influences of species,CO_(2)concentrations and planting year on AMF colonization were associated with their effects on both soil nutrient and AMF community,and the former may be more important as it also influenced the latter.Our results indicate that the invader could more quickly form symbiosis with soil AMF,contributing to adaptation and occupation of new habitats,and that it is necessary to consider the roles of AMF and the effects of time when determining the effects of global changes such as atmospheric CO_(2)enrichment on exotic plant invasions.
