The use patterns of salt marsh habitats by fish assemblages were investigated in two welldeveloped intertidal creeks in the Changjiang(Yangtze)River estuary on spatial and temporal scales.Samples were collected using ...The use patterns of salt marsh habitats by fish assemblages were investigated in two welldeveloped intertidal creeks in the Changjiang(Yangtze)River estuary on spatial and temporal scales.Samples were collected using fyke nets at two sites during day and night in each season throughout four years.Notable changes in fish assemblages were detected over seasonal and interannual cycles,with many more marine species present in winter assemblages,whereas freshwater and estuarine species characterized the other seasonal samplings.The appearance of catadromous species in intertidal creeks mainly depended upon their specific physiological requirements,such as spawning migration.No significant diel shifts were observed in fish assemblages.This diel pattern may be a combined consequence of avian predation pressure and other drivers(i.e.,inherent living behaviors,food availability,and predation by piscivorous fishes).The spatial difference in fish community was insignificant even though the two intertidal creeks were different in size.Intertidal creeks with different size could possess similar ecological value for fish fauna.Redundancy analysis(RDA)showed that biological factors exerted greater effects on fish assemblages than physical variables.Temporal variations were strongly facilitated by food availability,but negatively impacted by avian predation.Salinity,water temperature,and river runoff had weak influence on temporal variations of fish communities.The lengthfrequency distribution showed that the fish collected in these two sites mainly consisted of young-of-year and juvenile fish,which confirmed that the creeks provided important nursery and forage roles in the process of fish ontogenetic development.Further,we proposed that salt marsh conservation management should be equally applied to all well-developed intertidal creeks regardless of creek size.展开更多
Two-dimensional(2D)van der Waals layered materials have been widely used as lubricant.Penta-graphene(PG),a 2D carbon allotrope exclusively composed of irregular carbon pentagons has recently been predicted to have sup...Two-dimensional(2D)van der Waals layered materials have been widely used as lubricant.Penta-graphene(PG),a 2D carbon allotrope exclusively composed of irregular carbon pentagons has recently been predicted to have superlubricating property.In the present study,by combining the molecular dynamics simulation and first-principles calculations,we investigated the frictional property of PG in both commensurate and incommensurate contacts.Our calculations show the ultra-low friction at the interface of relatively rotated bilayer PG with twist angles of more than 10°away from the commensurate configuration.Meanwhile,our calculations demonstrate the isotropy of the ultra-low friction at the interface of incommensurate contact,in contrast to the anisotropic of the commensurate contacting interface.Additionally,the evolution of friction force and the fluctuation of potential energy along sliding path correlate closely with the interface’s structure.The energetics and charge density explain the difference between the friction at the interfaces of the commensurate and incommensurate contacts.Not only that,we found the correlation between the intrinsic structural feature and interlayer binding energy.Importantly,our findings on the retainment of the ultra-low friction under work conditions indicates that the superlubricating state of PG has good practical adaptability.展开更多
Dear Editor,Plant viruses make up almost half of the plant disease-causing pathogens,affecting crop yields and the global economy(Savary et al.,2019).Soybean(Glycine max)is one of the most valuable legume crops in the...Dear Editor,Plant viruses make up almost half of the plant disease-causing pathogens,affecting crop yields and the global economy(Savary et al.,2019).Soybean(Glycine max)is one of the most valuable legume crops in the world,supplying 25%of the global edible oil and two-thirds of the global concentrated protein for livestock feeding.Recently,the outbreak of soybean stay-green syndrome with delayed leaf senescence(stay-green),flat pods,and increased number of abnormal seeds has swept the soybean production in the Huang-Huai-Hai region of China,resulting in huge yield losses(Xu et al.,2019).This disease has become an epidemic and prominent problem in soybean production and is still expanding its geography,including North America,posing a serious threat to soybean production(Harbach et al.,2016;Zhang et al.,2016;Li et al.,2019).However,the cause of soybean stay-green syndrome remains obscure.展开更多
Background There are no data comparing a regular diet with a restricted diet after endoscopic polypectomy in patients with colorectal polyps.The current guidelines also did not provide the detailed information of diet...Background There are no data comparing a regular diet with a restricted diet after endoscopic polypectomy in patients with colorectal polyps.The current guidelines also did not provide the detailed information of dietary patterns after polypectomy.In this study,we aimed to evaluate the safety and efficacy of different diets on post-polypectomy outcomes.Methods A total of 302 patients with colorectal polyps who underwent polypectomy were prospectively enrolled between March 2019 and December 2019 in Nanfang Hospital(Guangzhou,China).Enrolled patients were then randomly assigned to a regular diet group or a restricted diet group after polypectomy.The study is a non-inferior design and the primary end point was the post-operative adverse events(AE)rate.Secondary end points included length of stay(LOS)and hospitalization cost.Results Among all the included patients,148 patients received a restricted diet and 154 patients received a regular diet after polypectomy.A total of 376 polyps were removed,with 183 polyps in the restricted diet group and 193 polyps in the regular diet group.Shorter LOS(4.0±1.4 vs 4.8±1.7,P<0.001)and lower hospitalization costs(7,701.63±2,579.07 vs 8,656.05±3,138.53,P=0.001)were observed in the regular diet group.In particular,there was no significant difference in 3-day AE rates between the restricted diet and the regular diet group(1.35%[2/148]vs 2.60%[4/154],P=0.685).Subgroup analysis looking at the number of polyps removed in each patient and different treatmentmodalities also showed similar findings.Conclusion Regular diet should be recommended after polypectomy for polyps<20mm as it can shorten LOS and save hospitalization costs.展开更多
基金Supported by the Science and Technology Commission of Shanghai Municipality (Nos.21DZ1200900,22DZ1202600)the National Natural Science Foundation of China (No.31772405)+3 种基金the Natural Science Foundation of Shanghai (No.19ZR1416200)the Resources Monitoring Project of Shanghai Chongming Dongtan National Nature Reserve (No.CMDT-JC202101)the Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station (No.K202205)the Fundamental Research Funds for the Central Universities。
文摘The use patterns of salt marsh habitats by fish assemblages were investigated in two welldeveloped intertidal creeks in the Changjiang(Yangtze)River estuary on spatial and temporal scales.Samples were collected using fyke nets at two sites during day and night in each season throughout four years.Notable changes in fish assemblages were detected over seasonal and interannual cycles,with many more marine species present in winter assemblages,whereas freshwater and estuarine species characterized the other seasonal samplings.The appearance of catadromous species in intertidal creeks mainly depended upon their specific physiological requirements,such as spawning migration.No significant diel shifts were observed in fish assemblages.This diel pattern may be a combined consequence of avian predation pressure and other drivers(i.e.,inherent living behaviors,food availability,and predation by piscivorous fishes).The spatial difference in fish community was insignificant even though the two intertidal creeks were different in size.Intertidal creeks with different size could possess similar ecological value for fish fauna.Redundancy analysis(RDA)showed that biological factors exerted greater effects on fish assemblages than physical variables.Temporal variations were strongly facilitated by food availability,but negatively impacted by avian predation.Salinity,water temperature,and river runoff had weak influence on temporal variations of fish communities.The lengthfrequency distribution showed that the fish collected in these two sites mainly consisted of young-of-year and juvenile fish,which confirmed that the creeks provided important nursery and forage roles in the process of fish ontogenetic development.Further,we proposed that salt marsh conservation management should be equally applied to all well-developed intertidal creeks regardless of creek size.
基金the Natural Science Fund of Shaanxi Province for the Key Project(No.2021JZ-07),Leading Talents in Scientific and Technological Innovation Program of Shaanxi Province,and the Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘Two-dimensional(2D)van der Waals layered materials have been widely used as lubricant.Penta-graphene(PG),a 2D carbon allotrope exclusively composed of irregular carbon pentagons has recently been predicted to have superlubricating property.In the present study,by combining the molecular dynamics simulation and first-principles calculations,we investigated the frictional property of PG in both commensurate and incommensurate contacts.Our calculations show the ultra-low friction at the interface of relatively rotated bilayer PG with twist angles of more than 10°away from the commensurate configuration.Meanwhile,our calculations demonstrate the isotropy of the ultra-low friction at the interface of incommensurate contact,in contrast to the anisotropic of the commensurate contacting interface.Additionally,the evolution of friction force and the fluctuation of potential energy along sliding path correlate closely with the interface’s structure.The energetics and charge density explain the difference between the friction at the interfaces of the commensurate and incommensurate contacts.Not only that,we found the correlation between the intrinsic structural feature and interlayer binding energy.Importantly,our findings on the retainment of the ultra-low friction under work conditions indicates that the superlubricating state of PG has good practical adaptability.
基金supported by the grants from National Natural Science Foundation of China Grants 31925032 and 32172376the Startup Fund for Distinguished Scholars from Nanjing Agricultural University to Y.X.and the Fundamental Research Funds for the Central Universities(JCQY202104)。
文摘Dear Editor,Plant viruses make up almost half of the plant disease-causing pathogens,affecting crop yields and the global economy(Savary et al.,2019).Soybean(Glycine max)is one of the most valuable legume crops in the world,supplying 25%of the global edible oil and two-thirds of the global concentrated protein for livestock feeding.Recently,the outbreak of soybean stay-green syndrome with delayed leaf senescence(stay-green),flat pods,and increased number of abnormal seeds has swept the soybean production in the Huang-Huai-Hai region of China,resulting in huge yield losses(Xu et al.,2019).This disease has become an epidemic and prominent problem in soybean production and is still expanding its geography,including North America,posing a serious threat to soybean production(Harbach et al.,2016;Zhang et al.,2016;Li et al.,2019).However,the cause of soybean stay-green syndrome remains obscure.
基金supported by the Science and Technology Planning Project of Guangdong Province[grant number 2017A020215139]Guangdong Gastrointestinal Disease Research Center[grant number 2017B020209003].
文摘Background There are no data comparing a regular diet with a restricted diet after endoscopic polypectomy in patients with colorectal polyps.The current guidelines also did not provide the detailed information of dietary patterns after polypectomy.In this study,we aimed to evaluate the safety and efficacy of different diets on post-polypectomy outcomes.Methods A total of 302 patients with colorectal polyps who underwent polypectomy were prospectively enrolled between March 2019 and December 2019 in Nanfang Hospital(Guangzhou,China).Enrolled patients were then randomly assigned to a regular diet group or a restricted diet group after polypectomy.The study is a non-inferior design and the primary end point was the post-operative adverse events(AE)rate.Secondary end points included length of stay(LOS)and hospitalization cost.Results Among all the included patients,148 patients received a restricted diet and 154 patients received a regular diet after polypectomy.A total of 376 polyps were removed,with 183 polyps in the restricted diet group and 193 polyps in the regular diet group.Shorter LOS(4.0±1.4 vs 4.8±1.7,P<0.001)and lower hospitalization costs(7,701.63±2,579.07 vs 8,656.05±3,138.53,P=0.001)were observed in the regular diet group.In particular,there was no significant difference in 3-day AE rates between the restricted diet and the regular diet group(1.35%[2/148]vs 2.60%[4/154],P=0.685).Subgroup analysis looking at the number of polyps removed in each patient and different treatmentmodalities also showed similar findings.Conclusion Regular diet should be recommended after polypectomy for polyps<20mm as it can shorten LOS and save hospitalization costs.
