Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and dist...Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and distribution of brominated flame retardants in sediments.The acute toxicity effects of tetrabromobisphenol A(TBBPA)and hexabromocyclododecane(HBCDs)in sediments were evaluated using Caenorhabditis elegans as model organisms.The concentration of TBBPA in sediments ranged from not detected(ND)to 12.59μg/kg andwas mainly distributed in the central area,whichwas affected by the emission of TBBPA from residential and factory.The concentration of HBCDs ranged from ND to 6.31μg/kg,and the diastereoisomer distribution was consistent,showing a trend close to the South China Sea.The composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%,7.89%-25.54%,and 18.76%-40.65%forα-,β-,andγ-HBCD,respectively,and in the sediments from reservoirs were 26.15%-45.52%,7.44%-19.23%,and 47.04%-61.89%forα-,β-,andγ-HBCD,respectively.When the sum of concentrations of TBBPA and HBCD in sediments were above high levels,reactive oxygen species in nematodes significantly increased,resulting in an oxidative stress response.Intestinal permeabilitywas also enhanced,causing intestinal damage.In addition,in terms of this study,TBBPA had a greater impact on biotoxicity compared to HBCDs,and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City,Guangdong Province.This study can complement the pollution database in the study area and provide basic data for pollution control.展开更多
Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of...Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of multiple zoological taxa on reservoir islands of a large lake in eastern China(Thousand Island Lake).This lake,created in 1959,has 1078 artificial land-bridge islands of varying areas and isolation.Our review summarizes the decades-long studies in island biogeography and habitat fragmentation from this island system,grouped into three topics:species richness(“how many species are there”),community structure(“who are they”),and species interaction(“how they interact with each other”).Our findings support the predictions of the Equilibrium Theory of Island Biogeography and extend this theory to predict community structure of island faunas by moving beyond assumptions of species equivalency.In addition,the extensive studies on ecological networks,including mutualistic,antagonistic,and parasitic interactions,reveal the negative impacts of habitat loss on the maintenance of such networks,even as increasing forest edge enhances the robustness of pollination networks.At the end of this review,we proposed several future research directions based on current studies that are simultaneously at the frontier of ecology and biogeography.展开更多
Abstract Nestedness is a pattern frequently reported for faunal assemblages in fragmented systems. Although nestedness has been documented for a wide range of taxa, it is rarely tested in snake assemblages. To arrive ...Abstract Nestedness is a pattern frequently reported for faunal assemblages in fragmented systems. Although nestedness has been documented for a wide range of taxa, it is rarely tested in snake assemblages. To arrive at robust generalizations about processes and mechanisms structuring island biotas, it is important to examine under-represented taxa such as snakes for the insights they may offer. We tested for the existence of nestedness and underlying causal mechanisms using snake data collected on islands in the Thousand Island Lake, China. We used the line-transect method to survey snake occupancy and abundance on 20 islands during two breeding seasons in 2009 and 2010. We used the recently developed metric WNODF to estimate nestedness. We used Spearman rank correlations to examine the associations of nestedness and habitat variables （area, isolation, and habitat diversity） as well as life-history traits （body size, clutch size, geographical range size and area requirement） related to species extinction and immigration tendencies. Snake assemblages were significantly nested and were shaped by extinction processes mediated through area effects and habitat nestedness. The nestedness of snake assemblages was not due to passive sampling or selective colonization. From a conservation viewpoint, our results indicate that we should protect both the largest island with the most species-rich community and habitat-rich islands to maximize the number of species preserved .展开更多
The small-island effect （SIE） has become more and more part of the theoretical framework of island biogeography and biodiversity research. However, previous methods for the detection of SlEs are often flawed in one ...The small-island effect （SIE） has become more and more part of the theoretical framework of island biogeography and biodiversity research. However, previous methods for the detection of SlEs are often flawed in one way or another, including not accounting for model complexity, not comparing all relevant models, and not including islands with no species. Therefore, the existence and the prevalence of the SIE may be dubious. In this study, after controlling for all these methodological shortcomings, we tested for the existence of the SlE in amphibian assemblages on subtropical landbridge islands created by the inundation of the Thousand Island Lake, China. We used the line transect method to determine the distribution of amphibian assemblages on 23 study islands during 3 breeding seasons from 2009 to 2011. To evaluate whether an SIE exists in amphibian assemblages, we compared the fit of a simple linearized power model with two most widely used breakpoint regression models. The information-theoretic multimodel inference approach based on Akaike＇s information criterion identified the left-horizontal SIE model as the best single model. Thus, we found strong evidence for the existence of an SIE in our system. The upper limit of the SlE for amphibian assemblages was 39.95 ha. Below this threshold area, amphibian richness varied independently of island size. The SlE in amphibian assemblages may be due to episodic disturbances, stochastic events, and nutrient subsidies from the lake. Our results indicate that all the islands 〉39.95 ha should be protected for the effective conservation of amphibian assemblages in our system.展开更多
Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology per...Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology perspective what is known about the structure and organization of flocks,emphasizing that flocking species tend to be those particularly vulnerable to predation,and flocks tend to be led by species that are able to act as sources of information about predators for other species.Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate,but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear.We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build.We then outline potentially fruitful future directions,focusing on studies that can investigate how dependent species are on each other in flocks,and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region.展开更多
Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other i...Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.展开更多
The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out...The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out as function of pH,temperature,agitation rate and concentration of Fe(Ⅲ)ions.The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were determined.The Langmuir model agrees very well with experimental data.The pseudo-first-order a...展开更多
Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic...Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic view of how species traits and habitat characteristics relate to metacommunity dynamics and use it to test for differences in the spatiotemporal distribution of seasonal bird assemblages. Methods: We surveyed forest birds in breeding and winter seasons within 36 islands for 9 years. We then grouped birds into four landbird assemblages, selected on the basis of published differences in biology or ecology: winter residents, migratory winter visitors, breeding summer residents, and migratory summer visitors. We estimated dynamic species colonization and extirpation through the 9-year period, and evaluated the associations among island attributes, species attributes and community composition. Results: Overall, winter and summer residents showed strong associations between composition and habitat structure of the islands. In addition, winter and summer residents on large islands had lower extirpation and turnover than winter and summer visitors. Visitor assemblages showed no significant habitat associations, and in winter had high extirpation rates and small body sizes. By contrast, local extirpation of summer visitors was correlated with local species richness, indicating a likely effect of competition on extirpation. Conclusions: Our results demonstrated repeated patterns among species composition, bird traits, habitat/island characteristics and observed metacommunity dynamics. Winter and summer residents best matched species sorting and patch dynamics, respectively, due to differences in resource availability and requirements of overwinter survival versus breeding. Summer visitors were consistent with species sorting and winter visitors were randomly distributed, likely because of interactions with resident competitors. Our results highlight that coexisting seasonal migrant and resident assemblages differ in their spatial dynamics, with consequences for relevant conservation and management strategies.展开更多
DEAR EDITOR：The species-area relationship（SAR）describes the phenomenon whereby the number of plant and animal species found in an area of wild habitat is strongly correlated with the size of that area.As one of the...DEAR EDITOR：The species-area relationship（SAR）describes the phenomenon whereby the number of plant and animal species found in an area of wild habitat is strongly correlated with the size of that area.As one of the few ecological laws,the SAR plays a vital role in the design and assessment of biodiversity protection regions（Lomolino et al,2010;Ladle＆Whittaker,2011）.Increasing area and habitat promote species richness（Triantis et al,2003）and both these mechanisms have展开更多
Objective To study the chemical constituents from Millettia speciosa. Methods The compounds were isolated and purified by silica gel, Sephadex LH-20, ODS column chromatography, and recrystallization. The structures we...Objective To study the chemical constituents from Millettia speciosa. Methods The compounds were isolated and purified by silica gel, Sephadex LH-20, ODS column chromatography, and recrystallization. The structures were identified using physicochemical and spectral data. Results Thirteen compounds were isolated from M. speciosa and identified as docosanoic acid （1）, tetracosane （2）, octadecane （3）, hexacosanoic acid （4）, β-sitosteroi acetate （5）, β-sitosterol （6）, syringin （7）, maackiain （8）, formononetin （9）, ψ-baptigenin （10）, rotundic acid （11）, pedunculoside （12）, and daucosterol （13）. Conclusion Compounds 5, 7, and 10-12 are obtained from this plant for the first time.展开更多
Alpinia officinarum is a medicinal plant and food. Its dried rhizome has been widely used for the relief of symptoms such as stomach aches, colds, ulcer and diarrhea for hundreds of years. Recent pharmacological studi...Alpinia officinarum is a medicinal plant and food. Its dried rhizome has been widely used for the relief of symptoms such as stomach aches, colds, ulcer and diarrhea for hundreds of years. Recent pharmacological studies showed it has anti-inflammatory, anti-oxidative, antidiabetic, anti-ulcer, anti-diarrhea, antiemetic,analgesia, anticoagulation, antitumor and antivitiligo effects. In this study, we summarized the current knowledge about its botanical resources, ethanopharmacological function, chemical constituents, pharmacologies and pharmacokinetics, safety and toxicity, and clinical application.展开更多
We present the carbon isotopic composition of the total organic carbon (TOC) and fine roots in the sedimentary profile from the underground ancient forest in Sihui to study the climatic and environmental changes from ...We present the carbon isotopic composition of the total organic carbon (TOC) and fine roots in the sedimentary profile from the underground ancient forest in Sihui to study the climatic and environmental changes from 4.5 ka BP to 0.6 ka BP. Results show t展开更多
Objective:To investigate therapeutic mechanism in Jasminum amplexicaule(Oleaceae)and verify its main active component as quality control markers Methods:Established mouse models of diarrhea,intestinal angina,and infla...Objective:To investigate therapeutic mechanism in Jasminum amplexicaule(Oleaceae)and verify its main active component as quality control markers Methods:Established mouse models of diarrhea,intestinal angina,and inflammation were firstly used to select herb fractions with optimum efficacy,followed by an in vitro experiment to determine key targets associated with effects of J.amplexicaule extract.The selected fractions were isolated and purified,its components were identified,and the obtained compounds were verified for their effects on NF-κB and i NOS.Finally,effective compounds were administered to rats,their plasma pharmacokinetic parameters were calculated,and quality markers(QMs)reflecting therapeutic activities of J.amplexicaule were confirmed.Results:Trichloromethane and ethyl acetate fractions had significant anti-diarrheal,anti-inflammatory,and analgesic effects.The trichloromethane fraction also reduced BDNF,p38 MAPK,p-p38 MAPK,NF-κB p65,and p-NF-κB p65 levels in the ileum in a rhubarb-induced diarrhea mouse model.Additionally,it inhibited LPS-induced NF-κB transcription and nitric oxide(NO)production in RAW264.7 macrophages,which suppressed i NOS expression.Therefore,the trichloromethane fraction was further investigated.QMs candidate selection identified 17 compounds,and results of in-vitro therapeutic validation indicated that methyl caffeate and isochlorogenic acid B had the strongest anti-diarrheal,anti-inflammatory,and analgesic activities.After being validated by a UHPLC–MS-MS method,concentrations of these target compounds were accurately determined in the rat plasma and pharmacokinetic parameters were calculated.Cmax,tmax,and t1/2 were respectively 575.35 ng/mL(2.963 nmol/mL),0.5 h,and 0.45 h for methyl caffeate and 262.03 ng/m L(0.5034 nmol/mL),0.25 h,and 2.03 h for isochlorogenic acid B.Because these candidate compounds exhibited favorable pharmacokinetics,they were considered as QMs of J.amplexicaule.Conclusions:The present study accurately and effectively identified QMs of J.amplexicaule that act as indicators of efficacy and quality.展开更多
Density-dependent non-monotonic species interactions are important in maintaining ecosystem stability and function,but empirical evidences are still rare.Rodents,as both seed dispersers and seed predators,have dual ef...Density-dependent non-monotonic species interactions are important in maintaining ecosystem stability and function,but empirical evidences are still rare.Rodents,as both seed dispersers and seed predators,have dual effects on plant regeneration and may result in non-monotonic rodent-plant interactions.According to the non-monotonic models,the relative positive or negative effects of rodents on seedling establishment can be measured based on the positive or negative association of seedling recruitment rate and rodent abundance.In this study,we investigated the fates of acorns of Quercus serrata by tracking tagged seeds on 21 fragmented subtropical islands in the Thousand Island Lake,China.We found that the proportion of germinated seeds of all released seeds showed a dome-shaped association with rodent abundance per seed.The proportion of removed seeds and cached seeds showed a saturated-and a weak dome-shaped association with rodent abundance per seed,respectively.Our results demonstrated a clear empirical evidence that rodent abundance per seed triggered a switch between the relative mutualism and predation in a rodent-seed system.Our study implied that the observed non-monotonic interactions between plants and animals may play a significant role in maintaining biodiversity and ecosystem function.We appeal for more investigations of the complex non-monotonic interactions in various ecosystems.展开更多
To the Editor:Critically ill patients are always complicated with systematic inflammation causing organ dysfunction,even multiple organ dysfunction syndrome(MODS)or sepsis,which commonly contributes to mortality in in...To the Editor:Critically ill patients are always complicated with systematic inflammation causing organ dysfunction,even multiple organ dysfunction syndrome(MODS)or sepsis,which commonly contributes to mortality in intensive care unit(ICU).It was originally thought that ferritin plays an important role in the hematopoietic system for its iron storage capacity.Recently,it was reported that the raised plasma ferritin is correlated with a poor prognosis of diseases.The level of ferritin could not only reflect disease activity,but also may predict the outcomes.[1]The relationship between plasma ferritin and clinical outcomes of critically ill or sepsis patients remained controversial.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFC3902102 and 2019YFC1803403)the Key Programof National Natural Science Foundation of China(No.41931298).
文摘Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and distribution of brominated flame retardants in sediments.The acute toxicity effects of tetrabromobisphenol A(TBBPA)and hexabromocyclododecane(HBCDs)in sediments were evaluated using Caenorhabditis elegans as model organisms.The concentration of TBBPA in sediments ranged from not detected(ND)to 12.59μg/kg andwas mainly distributed in the central area,whichwas affected by the emission of TBBPA from residential and factory.The concentration of HBCDs ranged from ND to 6.31μg/kg,and the diastereoisomer distribution was consistent,showing a trend close to the South China Sea.The composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%,7.89%-25.54%,and 18.76%-40.65%forα-,β-,andγ-HBCD,respectively,and in the sediments from reservoirs were 26.15%-45.52%,7.44%-19.23%,and 47.04%-61.89%forα-,β-,andγ-HBCD,respectively.When the sum of concentrations of TBBPA and HBCD in sediments were above high levels,reactive oxygen species in nematodes significantly increased,resulting in an oxidative stress response.Intestinal permeabilitywas also enhanced,causing intestinal damage.In addition,in terms of this study,TBBPA had a greater impact on biotoxicity compared to HBCDs,and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City,Guangdong Province.This study can complement the pollution database in the study area and provide basic data for pollution control.
基金supported by National Natural Science Foundation of China(32030066,32071545,32371590,32301330,32001124,32101268,32101278)。
文摘Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of multiple zoological taxa on reservoir islands of a large lake in eastern China(Thousand Island Lake).This lake,created in 1959,has 1078 artificial land-bridge islands of varying areas and isolation.Our review summarizes the decades-long studies in island biogeography and habitat fragmentation from this island system,grouped into three topics:species richness(“how many species are there”),community structure(“who are they”),and species interaction(“how they interact with each other”).Our findings support the predictions of the Equilibrium Theory of Island Biogeography and extend this theory to predict community structure of island faunas by moving beyond assumptions of species equivalency.In addition,the extensive studies on ecological networks,including mutualistic,antagonistic,and parasitic interactions,reveal the negative impacts of habitat loss on the maintenance of such networks,even as increasing forest edge enhances the robustness of pollination networks.At the end of this review,we proposed several future research directions based on current studies that are simultaneously at the frontier of ecology and biogeography.
基金We thank two anonymous reviewers for helpful comments on earlier version of the manuscript. We are grateful to Chunan Forestry Bureau and the Thousand Island Lake National Forest Park for permits necessary to conduct the research. This study was supported by the National Natural Science Foundation of China （Nos. 31100394, 31170397）, the China Postdoctoral Science Foundation （No. 20070411192）, Zhejiang Provincial Postdoctoral Science Foundation, and the Fundamental Research Funds for the Central Universities.
文摘Abstract Nestedness is a pattern frequently reported for faunal assemblages in fragmented systems. Although nestedness has been documented for a wide range of taxa, it is rarely tested in snake assemblages. To arrive at robust generalizations about processes and mechanisms structuring island biotas, it is important to examine under-represented taxa such as snakes for the insights they may offer. We tested for the existence of nestedness and underlying causal mechanisms using snake data collected on islands in the Thousand Island Lake, China. We used the line-transect method to survey snake occupancy and abundance on 20 islands during two breeding seasons in 2009 and 2010. We used the recently developed metric WNODF to estimate nestedness. We used Spearman rank correlations to examine the associations of nestedness and habitat variables （area, isolation, and habitat diversity） as well as life-history traits （body size, clutch size, geographical range size and area requirement） related to species extinction and immigration tendencies. Snake assemblages were significantly nested and were shaped by extinction processes mediated through area effects and habitat nestedness. The nestedness of snake assemblages was not due to passive sampling or selective colonization. From a conservation viewpoint, our results indicate that we should protect both the largest island with the most species-rich community and habitat-rich islands to maximize the number of species preserved .
基金The study was supported by the National Natural Science Foundation of China （31471981, 31100394, and 31210103908）, the Project-sponsored by SRF for ROCS, SEM （J20130585） and the Fundamental Research Funds for the Central Universities （2016QNA6001 ）.
文摘The small-island effect （SIE） has become more and more part of the theoretical framework of island biogeography and biodiversity research. However, previous methods for the detection of SlEs are often flawed in one way or another, including not accounting for model complexity, not comparing all relevant models, and not including islands with no species. Therefore, the existence and the prevalence of the SIE may be dubious. In this study, after controlling for all these methodological shortcomings, we tested for the existence of the SlE in amphibian assemblages on subtropical landbridge islands created by the inundation of the Thousand Island Lake, China. We used the line transect method to determine the distribution of amphibian assemblages on 23 study islands during 3 breeding seasons from 2009 to 2011. To evaluate whether an SIE exists in amphibian assemblages, we compared the fit of a simple linearized power model with two most widely used breakpoint regression models. The information-theoretic multimodel inference approach based on Akaike＇s information criterion identified the left-horizontal SIE model as the best single model. Thus, we found strong evidence for the existence of an SIE in our system. The upper limit of the SlE for amphibian assemblages was 39.95 ha. Below this threshold area, amphibian richness varied independently of island size. The SlE in amphibian assemblages may be due to episodic disturbances, stochastic events, and nutrient subsidies from the lake. Our results indicate that all the islands 〉39.95 ha should be protected for the effective conservation of amphibian assemblages in our system.
基金the 1000 Plan Recruitment Program of Global Experts of the People’s Republic of Chinathe Special Talent Recruitment Program of Guangxi University for support
文摘Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology perspective what is known about the structure and organization of flocks,emphasizing that flocking species tend to be those particularly vulnerable to predation,and flocks tend to be led by species that are able to act as sources of information about predators for other species.Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate,but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear.We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build.We then outline potentially fruitful future directions,focusing on studies that can investigate how dependent species are on each other in flocks,and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region.
基金supported by the National Natural Science Foundation of China (No. 31170397)the Fundamental Research Funds for the Central Universities
文摘Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.
基金This work was financially supported by the National Science Foundation of China(No.20376085).
文摘The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out as function of pH,temperature,agitation rate and concentration of Fe(Ⅲ)ions.The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were determined.The Langmuir model agrees very well with experimental data.The pseudo-first-order a...
基金supported by National Natural Science Foundation of China(Grants 31210103908 and 31572250 to PD,Grant 31500453 to XS,Grants 31471981 and 31770462 to YW)Jiangsu Postdoctoral Research Foundation(2018K169C)supported by Agricultural Experiment Station to the University of California at Davis
文摘Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic view of how species traits and habitat characteristics relate to metacommunity dynamics and use it to test for differences in the spatiotemporal distribution of seasonal bird assemblages. Methods: We surveyed forest birds in breeding and winter seasons within 36 islands for 9 years. We then grouped birds into four landbird assemblages, selected on the basis of published differences in biology or ecology: winter residents, migratory winter visitors, breeding summer residents, and migratory summer visitors. We estimated dynamic species colonization and extirpation through the 9-year period, and evaluated the associations among island attributes, species attributes and community composition. Results: Overall, winter and summer residents showed strong associations between composition and habitat structure of the islands. In addition, winter and summer residents on large islands had lower extirpation and turnover than winter and summer visitors. Visitor assemblages showed no significant habitat associations, and in winter had high extirpation rates and small body sizes. By contrast, local extirpation of summer visitors was correlated with local species richness, indicating a likely effect of competition on extirpation. Conclusions: Our results demonstrated repeated patterns among species composition, bird traits, habitat/island characteristics and observed metacommunity dynamics. Winter and summer residents best matched species sorting and patch dynamics, respectively, due to differences in resource availability and requirements of overwinter survival versus breeding. Summer visitors were consistent with species sorting and winter visitors were randomly distributed, likely because of interactions with resident competitors. Our results highlight that coexisting seasonal migrant and resident assemblages differ in their spatial dynamics, with consequences for relevant conservation and management strategies.
基金supported by the National Natural Science Foundation of China(31170397)
文摘DEAR EDITOR：The species-area relationship（SAR）describes the phenomenon whereby the number of plant and animal species found in an area of wild habitat is strongly correlated with the size of that area.As one of the few ecological laws,the SAR plays a vital role in the design and assessment of biodiversity protection regions（Lomolino et al,2010;Ladle＆Whittaker,2011）.Increasing area and habitat promote species richness（Triantis et al,2003）and both these mechanisms have
基金Natural Science Foundation of Guangdong Province (No.9151040701000037)
文摘Objective To study the chemical constituents from Millettia speciosa. Methods The compounds were isolated and purified by silica gel, Sephadex LH-20, ODS column chromatography, and recrystallization. The structures were identified using physicochemical and spectral data. Results Thirteen compounds were isolated from M. speciosa and identified as docosanoic acid （1）, tetracosane （2）, octadecane （3）, hexacosanoic acid （4）, β-sitosteroi acetate （5）, β-sitosterol （6）, syringin （7）, maackiain （8）, formononetin （9）, ψ-baptigenin （10）, rotundic acid （11）, pedunculoside （12）, and daucosterol （13）. Conclusion Compounds 5, 7, and 10-12 are obtained from this plant for the first time.
基金supported by the National Key R&D Program of China (No. 2017YFC1701104)Guangdong Province Applied Science and Technology R&D Special Fund Project (No. 2015B020234002)
文摘Alpinia officinarum is a medicinal plant and food. Its dried rhizome has been widely used for the relief of symptoms such as stomach aches, colds, ulcer and diarrhea for hundreds of years. Recent pharmacological studies showed it has anti-inflammatory, anti-oxidative, antidiabetic, anti-ulcer, anti-diarrhea, antiemetic,analgesia, anticoagulation, antitumor and antivitiligo effects. In this study, we summarized the current knowledge about its botanical resources, ethanopharmacological function, chemical constituents, pharmacologies and pharmacokinetics, safety and toxicity, and clinical application.
基金Supported by National Natural Science Foundation of China (Grant Nos. 40231015 and 40473002)National Basic Research Program of China (Grant No. 2005CB422004)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KSCX2-SW-133)Open Funds of State Key Laboratory of Organic Geochemistry (Grant No. OGL-200607)
文摘We present the carbon isotopic composition of the total organic carbon (TOC) and fine roots in the sedimentary profile from the underground ancient forest in Sihui to study the climatic and environmental changes from 4.5 ka BP to 0.6 ka BP. Results show t
基金the open topic grant of Guangxi Key Laboratory for TCM Quality Control Research(Gui Zhong Zhong Kai 201402)Guangxi Institute of Chinese Medicine and Pharmaceutical Science for financial support.
文摘Objective:To investigate therapeutic mechanism in Jasminum amplexicaule(Oleaceae)and verify its main active component as quality control markers Methods:Established mouse models of diarrhea,intestinal angina,and inflammation were firstly used to select herb fractions with optimum efficacy,followed by an in vitro experiment to determine key targets associated with effects of J.amplexicaule extract.The selected fractions were isolated and purified,its components were identified,and the obtained compounds were verified for their effects on NF-κB and i NOS.Finally,effective compounds were administered to rats,their plasma pharmacokinetic parameters were calculated,and quality markers(QMs)reflecting therapeutic activities of J.amplexicaule were confirmed.Results:Trichloromethane and ethyl acetate fractions had significant anti-diarrheal,anti-inflammatory,and analgesic effects.The trichloromethane fraction also reduced BDNF,p38 MAPK,p-p38 MAPK,NF-κB p65,and p-NF-κB p65 levels in the ileum in a rhubarb-induced diarrhea mouse model.Additionally,it inhibited LPS-induced NF-κB transcription and nitric oxide(NO)production in RAW264.7 macrophages,which suppressed i NOS expression.Therefore,the trichloromethane fraction was further investigated.QMs candidate selection identified 17 compounds,and results of in-vitro therapeutic validation indicated that methyl caffeate and isochlorogenic acid B had the strongest anti-diarrheal,anti-inflammatory,and analgesic activities.After being validated by a UHPLC–MS-MS method,concentrations of these target compounds were accurately determined in the rat plasma and pharmacokinetic parameters were calculated.Cmax,tmax,and t1/2 were respectively 575.35 ng/mL(2.963 nmol/mL),0.5 h,and 0.45 h for methyl caffeate and 262.03 ng/m L(0.5034 nmol/mL),0.25 h,and 2.03 h for isochlorogenic acid B.Because these candidate compounds exhibited favorable pharmacokinetics,they were considered as QMs of J.amplexicaule.Conclusions:The present study accurately and effectively identified QMs of J.amplexicaule that act as indicators of efficacy and quality.
基金supported by the National Natural Science Foundation of China(31872210,31930073,31210103908)by the China Postdoctoral Science Foundation(2019M662031)partially by the National Key Research and Development Program of China(2017YFC0503802).
文摘Density-dependent non-monotonic species interactions are important in maintaining ecosystem stability and function,but empirical evidences are still rare.Rodents,as both seed dispersers and seed predators,have dual effects on plant regeneration and may result in non-monotonic rodent-plant interactions.According to the non-monotonic models,the relative positive or negative effects of rodents on seedling establishment can be measured based on the positive or negative association of seedling recruitment rate and rodent abundance.In this study,we investigated the fates of acorns of Quercus serrata by tracking tagged seeds on 21 fragmented subtropical islands in the Thousand Island Lake,China.We found that the proportion of germinated seeds of all released seeds showed a dome-shaped association with rodent abundance per seed.The proportion of removed seeds and cached seeds showed a saturated-and a weak dome-shaped association with rodent abundance per seed,respectively.Our results demonstrated a clear empirical evidence that rodent abundance per seed triggered a switch between the relative mutualism and predation in a rodent-seed system.Our study implied that the observed non-monotonic interactions between plants and animals may play a significant role in maintaining biodiversity and ecosystem function.We appeal for more investigations of the complex non-monotonic interactions in various ecosystems.
基金Northern Jiangsu People’s Hospital Foundation(Nos. yzucms 201919 and yzucms202001)
文摘To the Editor:Critically ill patients are always complicated with systematic inflammation causing organ dysfunction,even multiple organ dysfunction syndrome(MODS)or sepsis,which commonly contributes to mortality in intensive care unit(ICU).It was originally thought that ferritin plays an important role in the hematopoietic system for its iron storage capacity.Recently,it was reported that the raised plasma ferritin is correlated with a poor prognosis of diseases.The level of ferritin could not only reflect disease activity,but also may predict the outcomes.[1]The relationship between plasma ferritin and clinical outcomes of critically ill or sepsis patients remained controversial.
