Helicobacter pylori(H.pylori)infection remains a pivotal driver of chronic gastritis,peptic ulcer,gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer,yet its eradication is increasingly frustrated by...Helicobacter pylori(H.pylori)infection remains a pivotal driver of chronic gastritis,peptic ulcer,gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer,yet its eradication is increasingly frustrated by climbing antibiotic resistance and intolerable side-effects of standard triple or quadruple therapies.In recent years,fecal microbiota transplantation(FMT),a strategy that reconstructs the gut ecosystem by introducing a healthy donor microbiome,has emerged as a novel adjunct or alternative.By competitively excluding H.pylori,reinforcing mucosal barrier integrity,modulating host immunity and secreting bacteriocins,FMT can raise eradication rates,relieve dyspeptic symptoms and lower recurrence.This review synthesizes up-to-date pre-clinical,pilot and controlled clinical data,dissects underlying mechanisms,compares delivery routes,donor screening protocols and safety profiles,and discusses regulatory,ethical and standardization hurdles that must be overcome before large-scale clinical application.展开更多
Background:The importance of biodiversity in maintaining multiple ecosystem functions has been widely accepted.However,the specific mechanisms affecting biodiversity and ecosystem multifunctionality(BEMF)relationships...Background:The importance of biodiversity in maintaining multiple ecosystem functions has been widely accepted.However,the specific mechanisms affecting biodiversity and ecosystem multifunctionality(BEMF)relationships in forests are largely unknown.This is particularly evident for the macroscale of a large forested landscape.Methods:Based on 412 one-tenth hectare field plots distributed over forested areas across northeastern China,we evaluated three alternative hypotheses explaining the relationships between BEMF,namely:niche complementarity,mass ratio,and vegetation quantity effect.We used Rao's quadratic entropy and community weighted mean trait values to quantify forest“biodiversity”.These two variables represent two complementary aspects of functional properties,which are in line with niche complementary and mass ratio effects,respectively.Results:Ecosystem multifunctionality was negatively associated with the community weighted mean values of acquisitive traits(a proxy of mass ratio effect).Rao's quadratic entropy(a proxy of niche complementarity)had no relationship with ecosystem multifunctionality.Higher stand biomass greatly increased ecosystem multifunctionality,which is in line with the vegetation quantity effect.Our results confirm that in the temperate forests of northeastern China,the relationship of BEMF was primarily affected by vegetation quantity,followed by mass ratio effects.Conclusions:The results of this study contribute to a better understanding of the main drivers of ecosystem multifunctionality in forest ecosystems.The results of this study provide additional evidence to support the vegetation quantity and mass ratio hypotheses in forest ecosystems.展开更多
Background: The demographic trade-offs(i.e. growth and survival) play important roles in forest dynamics and they are driven by multiple factors, including species’ inherent life-history strategies(such as shade-tole...Background: The demographic trade-offs(i.e. growth and survival) play important roles in forest dynamics and they are driven by multiple factors, including species’ inherent life-history strategies(such as shade-tolerance and mycorrhizal type), neighborhood interactions(such as conspecific negative density dependence, CNDD), and abiotic environment pressures. Although studies found that CNDD occurred in tropical and temperate forest,attempts to identify how the variations in CNDD control their impacts on growth and survival remain debate. In the present study, we conducted an extensive field survey, and analyzed demographic rates from 24 co-occurring temperate tree species, in order to test the importance of CNDD in shaping the growth-survival trade-offs.Results: Our study found that density dependence and environmental filtering were strong predictors for individual growth-survival trade-offs, while they showed variations across shade-intolerant and ectomycorrhizal species, as well as saplings and juveniles with more negative CNDD. Species growth showed positive relationship with mortality. And our results also support the fact that CNDD drives species growth-survival trade-offs at the community level with environmental stress.Conclusions: Our study indicates that biotic interactions such as density dependence and environment filtering played an important role in growth-survival trade-offs, and confirmed that the Janzen-Connell hypothesis in temperate forest was associated with species life-history strategies. In addition, shade-tolerance, mycorrhizal type and life-stage of forest species responded differently to CNDD, thus providing insights regarding different community assembly mechanisms and their interactions. Therefore, it is important to take species survival with growth and species life-history strategies into account when focusing on forest dynamics.展开更多
In this paper, a quasi-Newton-type optimized iterative learning control （ILC） algorithm is investigated for a class of discrete linear time-invariant systems. The proposed learning algorithm is to update the learnin...In this paper, a quasi-Newton-type optimized iterative learning control （ILC） algorithm is investigated for a class of discrete linear time-invariant systems. The proposed learning algorithm is to update the learning gain matrix by a quasi-Newton-type matrix instead of the inversion of the plant. By means of the mathematical inductive method, the monotone convergence of the proposed algorithm is analyzed, which shows that the tracking error monotonously converges to zero after a finite number of iterations. Compared with the existing optimized ILC algorithms, due to the superlinear convergence of quasi-Newton method, the proposed learning law operates with a faster convergent rate and is robust to the ill-condition of the system model, and thus owns a wide range of applications. Numerical simulations demonstrate the validity and effectiveness.展开更多
A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount...A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount of H_(2)P-Bph-COF at room temperature,various substituted N,N-dimethylanilines and N-aryl maleimides were transformed to tetrahydroquinoline derivatives in moderate to good yields.This was the first example of the synthesis of tetrahydroquinolines via the photocatalytic aerobic annulation reaction employing the metal-free COF as the heterogeneous photocatalyst.展开更多
By applying two donor-acceptor motif molecules,5,10-di(pyridin-4-yl)-5,10-dihydrophenazine(L1)and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine(L2),as ligands and CuI/AgCF3CO2 as metal salt,we synthe...By applying two donor-acceptor motif molecules,5,10-di(pyridin-4-yl)-5,10-dihydrophenazine(L1)and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine(L2),as ligands and CuI/AgCF3CO2 as metal salt,we synthesized three coordination polymers,namely,{Cu4(L1)2I4}(CP1),{Cu(L2)I·CHCl3}(CP2)and{Ag(L2)CO2CF3·CHCl3}(CP3).X-ray crystallographic analysis revealed that three coordination polymers all feature one-dimensional(1D)linear chains which are consisting of molecular boxlike units.In comparison with low photoluminescence quantum yield(PLQY)of two ligands,three coordination polymers,CP1,CP2 and CP3,present more intense photoluminescence with PLQY of 15%,46%and 34%at room temperature respectively.The PL emission of CP1 and CP2 at room temperature could be attributed to the fast phosphorescence with lifetime both around 5 ms due to effective intersystem crossing(ISC).Whilst,it is worth noting that CP3 exhibit thermally activated delayed fluorescence(TADF)emission at room temperature.展开更多
Because the conventional ultra wideband（UWB） radar imaging algorithm cannot meet the demand in the capability of multiple targets detection,a novel UWB radar imaging algorithm based on the near field radiation theor...Because the conventional ultra wideband（UWB） radar imaging algorithm cannot meet the demand in the capability of multiple targets detection,a novel UWB radar imaging algorithm based on the near field radiation theory of dipole is presented.On the foundation of researching the principle of a time domain imaging algorithm,the back projection（BP） algorithm is derived and analyzed.Firstly,the far field sampling data are transferred to the near field sampling data by using the near field radiation theory of dipole.Then the BP algorithm is applied to target detection.The capability of the new algorithm to detect the multi-target is verified by using the finite-difference time-domain method,and the threedimensional images of targets are obtained.The coupling effect between targets for imaging is analyzed.The simulation results show that the new UWB radar imaging algorithm based on the near field radiation theory of dipole could weaken the coupling effect for imaging,and as a result the quality of imaging is improved.展开更多
In this paper,approximate nutritional components and amino acid content were determined in muscles of female wild population(WP)with body weight of 2500-3000 g and female cultured population(CP)with body weight of 750...In this paper,approximate nutritional components and amino acid content were determined in muscles of female wild population(WP)with body weight of 2500-3000 g and female cultured population(CP)with body weight of 750-1250 g masu salmon Oncorhynchus masou in the gonadal development stage IV by conventional method.The results showed that there were significantly higher crude protein and significantly lower crude fat in fresh muscle of WP than that in CP(P<0.05),but not significant differences in the contents of moisture and crude ash between WP and CP(P>0.05).Eighteen kinds of amino acids were detected in muscles of WP and CP,with higher total content of amino acids(TAA),essential amino acids(EAA)and four kinds of delicious amino acids(DAA)in WP than those in CP(P<0.05).The amino acid score(AAS)and chemical score(CS)revealed that the first limiting amino acid was tryptophan in two populations,with essential amino acid index(EAAI)of 75.59%in WP and 70.77%in CP.The findings indicated that the amino acid contents in muscles of CP are lower than that of WP,but the amino acid nutritional value evaluation indicators of both populations are very close,and both have high nutritional value.展开更多
基金the 2026 Health Commission Fund of Guizhou Province,China.the freestatistics suite for its technical support.
文摘Helicobacter pylori(H.pylori)infection remains a pivotal driver of chronic gastritis,peptic ulcer,gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer,yet its eradication is increasingly frustrated by climbing antibiotic resistance and intolerable side-effects of standard triple or quadruple therapies.In recent years,fecal microbiota transplantation(FMT),a strategy that reconstructs the gut ecosystem by introducing a healthy donor microbiome,has emerged as a novel adjunct or alternative.By competitively excluding H.pylori,reinforcing mucosal barrier integrity,modulating host immunity and secreting bacteriocins,FMT can raise eradication rates,relieve dyspeptic symptoms and lower recurrence.This review synthesizes up-to-date pre-clinical,pilot and controlled clinical data,dissects underlying mechanisms,compares delivery routes,donor screening protocols and safety profiles,and discusses regulatory,ethical and standardization hurdles that must be overcome before large-scale clinical application.
基金supported by the Program of National Natural Science Foundation of China(No.31971650)the Key Project of National Key Research and Development Plan(No.2017YFC0504005)the National Natural Science Foundation of China(No.31800362).
文摘Background:The importance of biodiversity in maintaining multiple ecosystem functions has been widely accepted.However,the specific mechanisms affecting biodiversity and ecosystem multifunctionality(BEMF)relationships in forests are largely unknown.This is particularly evident for the macroscale of a large forested landscape.Methods:Based on 412 one-tenth hectare field plots distributed over forested areas across northeastern China,we evaluated three alternative hypotheses explaining the relationships between BEMF,namely:niche complementarity,mass ratio,and vegetation quantity effect.We used Rao's quadratic entropy and community weighted mean trait values to quantify forest“biodiversity”.These two variables represent two complementary aspects of functional properties,which are in line with niche complementary and mass ratio effects,respectively.Results:Ecosystem multifunctionality was negatively associated with the community weighted mean values of acquisitive traits(a proxy of mass ratio effect).Rao's quadratic entropy(a proxy of niche complementarity)had no relationship with ecosystem multifunctionality.Higher stand biomass greatly increased ecosystem multifunctionality,which is in line with the vegetation quantity effect.Our results confirm that in the temperate forests of northeastern China,the relationship of BEMF was primarily affected by vegetation quantity,followed by mass ratio effects.Conclusions:The results of this study contribute to a better understanding of the main drivers of ecosystem multifunctionality in forest ecosystems.The results of this study provide additional evidence to support the vegetation quantity and mass ratio hypotheses in forest ecosystems.
基金supported by the Program of National Natural Science Foundation of China(No.31971650)the Key Project of National Key Research and Development Plan(No.2017YFC0504104)Beijing Forestry University Outstanding Young Talent Cultivation Project(No.2019JQ03001).
文摘Background: The demographic trade-offs(i.e. growth and survival) play important roles in forest dynamics and they are driven by multiple factors, including species’ inherent life-history strategies(such as shade-tolerance and mycorrhizal type), neighborhood interactions(such as conspecific negative density dependence, CNDD), and abiotic environment pressures. Although studies found that CNDD occurred in tropical and temperate forest,attempts to identify how the variations in CNDD control their impacts on growth and survival remain debate. In the present study, we conducted an extensive field survey, and analyzed demographic rates from 24 co-occurring temperate tree species, in order to test the importance of CNDD in shaping the growth-survival trade-offs.Results: Our study found that density dependence and environmental filtering were strong predictors for individual growth-survival trade-offs, while they showed variations across shade-intolerant and ectomycorrhizal species, as well as saplings and juveniles with more negative CNDD. Species growth showed positive relationship with mortality. And our results also support the fact that CNDD drives species growth-survival trade-offs at the community level with environmental stress.Conclusions: Our study indicates that biotic interactions such as density dependence and environment filtering played an important role in growth-survival trade-offs, and confirmed that the Janzen-Connell hypothesis in temperate forest was associated with species life-history strategies. In addition, shade-tolerance, mycorrhizal type and life-stage of forest species responded differently to CNDD, thus providing insights regarding different community assembly mechanisms and their interactions. Therefore, it is important to take species survival with growth and species life-history strategies into account when focusing on forest dynamics.
基金supported by the National Natural Science Foundation of China(Nos.F010114-60974140,61273135)
文摘In this paper, a quasi-Newton-type optimized iterative learning control （ILC） algorithm is investigated for a class of discrete linear time-invariant systems. The proposed learning algorithm is to update the learning gain matrix by a quasi-Newton-type matrix instead of the inversion of the plant. By means of the mathematical inductive method, the monotone convergence of the proposed algorithm is analyzed, which shows that the tracking error monotonously converges to zero after a finite number of iterations. Compared with the existing optimized ILC algorithms, due to the superlinear convergence of quasi-Newton method, the proposed learning law operates with a faster convergent rate and is robust to the ill-condition of the system model, and thus owns a wide range of applications. Numerical simulations demonstrate the validity and effectiveness.
基金the financial support from the National Natural Science Foundation of China(Nos.22101158,22171169,21971153 and 21772116)the Natural Science Foundation of Shandong Province(No.ZR2021MB088)+2 种基金the Taishan Scholars Climbing Program of Shandong Provincethe Taishan Scholar Project of Shandong Provincethe Major Basic Research Projects of Shandong Natural Science Foundation(No.ZR2020ZD32)。
文摘A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount of H_(2)P-Bph-COF at room temperature,various substituted N,N-dimethylanilines and N-aryl maleimides were transformed to tetrahydroquinoline derivatives in moderate to good yields.This was the first example of the synthesis of tetrahydroquinolines via the photocatalytic aerobic annulation reaction employing the metal-free COF as the heterogeneous photocatalyst.
基金financially supported by the National Natural Science Foundation (Nos.21772116,21671122 and 21475078)the Shandong Taishan Scholar’s Construction Project,JSPS KAKENHI (No.JP17H01232)the Japan Science and Technology Agency (JST),ERATO,Adachi Molecular Exciton Engineering Project,under JST ERATO (No.JPMJER1305),Japan
文摘By applying two donor-acceptor motif molecules,5,10-di(pyridin-4-yl)-5,10-dihydrophenazine(L1)and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine(L2),as ligands and CuI/AgCF3CO2 as metal salt,we synthesized three coordination polymers,namely,{Cu4(L1)2I4}(CP1),{Cu(L2)I·CHCl3}(CP2)and{Ag(L2)CO2CF3·CHCl3}(CP3).X-ray crystallographic analysis revealed that three coordination polymers all feature one-dimensional(1D)linear chains which are consisting of molecular boxlike units.In comparison with low photoluminescence quantum yield(PLQY)of two ligands,three coordination polymers,CP1,CP2 and CP3,present more intense photoluminescence with PLQY of 15%,46%and 34%at room temperature respectively.The PL emission of CP1 and CP2 at room temperature could be attributed to the fast phosphorescence with lifetime both around 5 ms due to effective intersystem crossing(ISC).Whilst,it is worth noting that CP3 exhibit thermally activated delayed fluorescence(TADF)emission at room temperature.
基金supported by the Key Laboratory of Millimeter Waves of China (K200907)
文摘Because the conventional ultra wideband（UWB） radar imaging algorithm cannot meet the demand in the capability of multiple targets detection,a novel UWB radar imaging algorithm based on the near field radiation theory of dipole is presented.On the foundation of researching the principle of a time domain imaging algorithm,the back projection（BP） algorithm is derived and analyzed.Firstly,the far field sampling data are transferred to the near field sampling data by using the near field radiation theory of dipole.Then the BP algorithm is applied to target detection.The capability of the new algorithm to detect the multi-target is verified by using the finite-difference time-domain method,and the threedimensional images of targets are obtained.The coupling effect between targets for imaging is analyzed.The simulation results show that the new UWB radar imaging algorithm based on the near field radiation theory of dipole could weaken the coupling effect for imaging,and as a result the quality of imaging is improved.
基金the Project of Beijing Sturgeon-Salmon and Trout Innovation Team(BAIC08-2019).
文摘In this paper,approximate nutritional components and amino acid content were determined in muscles of female wild population(WP)with body weight of 2500-3000 g and female cultured population(CP)with body weight of 750-1250 g masu salmon Oncorhynchus masou in the gonadal development stage IV by conventional method.The results showed that there were significantly higher crude protein and significantly lower crude fat in fresh muscle of WP than that in CP(P<0.05),but not significant differences in the contents of moisture and crude ash between WP and CP(P>0.05).Eighteen kinds of amino acids were detected in muscles of WP and CP,with higher total content of amino acids(TAA),essential amino acids(EAA)and four kinds of delicious amino acids(DAA)in WP than those in CP(P<0.05).The amino acid score(AAS)and chemical score(CS)revealed that the first limiting amino acid was tryptophan in two populations,with essential amino acid index(EAAI)of 75.59%in WP and 70.77%in CP.The findings indicated that the amino acid contents in muscles of CP are lower than that of WP,but the amino acid nutritional value evaluation indicators of both populations are very close,and both have high nutritional value.
