Currently, land resources are becoming more and more constrained and structures are getting closer to each other. To investigate the seismic response of inter-story isolated structure to adjacent structure, models con...Currently, land resources are becoming more and more constrained and structures are getting closer to each other. To investigate the seismic response of inter-story isolated structure to adjacent structure, models considering no soil-structure interaction (SSI), considering soil-structure interaction (SSI), and considering structure-soil-structure interaction (SSSI) were established. Nonlinear seismic response comparative analysis was conducted by varying the spacing between adjacent structure and inter-story isolated structure, as well as the weight of adjacent structure, under different earthquake inputs, in order to obtain the structural response characteristics. The results indicate that the inter-story drift and inter-story shear of the inter-story isolated structure without considering SSI are smaller than those considering SSI and SSSI. The inter-story drift and inter-story shear of the inter-story isolated structure considering SSSI are further affected compared to that of the inter-story isolated structure considering only SSI. As the spacing between adjacent structure and inter-story isolated structure increases, the influence of adjacent structure on inter-story isolated structure decreases. The variation in the spacing between the two structures has a negligible effect on the isolation layer of the inter-story isolated structure. With the increase in the weight of adjacent structure, the influence of adjacent structure on inter-story isolated structure becomes more significant. The increasing weight of adjacent structure has an increasing effect on the Isolation layer of the inter-story isolated structure.展开更多
objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but n...objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but not evidence-confirmed.This study aimed to determine the clinical value of 2IC+2CCRT regarding efficacy,toxicity and cost-effectiveness.Methods:This real-world study from two epidemic centers used propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)analyses.The enrolled patients were divided into three groups based on treatment modality:Group A(2IC+2CCRT),Group B(3IC+2CCRT or 2IC+3CCRT)and Group C(3IC+3CCRT).Long-term survival,acute toxicities and cost-effectiveness were compared among the groups.We developed a prognostic model dividing the population into high-and low-risk cohorts,and survivals including overall survival(OS),progression-free survival(PFS),distant metastasis-free survival(DMFS)and locoregional relapse-free survival(LRRFS)were compared among the three groups according to certain risk stratifications.Results:Of 4,042 patients,1,175 were enrolled,with 660,419,and 96 included in Groups A,B and C,respectively.Five-year survivals were similar among the three groups after PSM and confirmed by IPTW.Grade 3-4 neutropenia and leukocytopenia were significantly higher in Groups C and B than in Group A(52.1%vs.41.5%vs.25.2%;41.7%vs.32.7%vs.25.0%)as were grade 3-4 nausea/vomiting and oral mucositis(29.2%vs.15.0%vs.6.1%;32.3%vs.25.3%vs.18.0%).Cost-effective analysis suggested that 2IC+2CCRT was the least expensive,while the health benefits were similar to those of the other groups.Further exploration showed that 2IC+2CCRT tended to be associated with a shorter PFS in high-risk patients,while 3IC+3CCRT potentially contributed to poor PFS in low-risk individuals,mainly reflected by LRRFS.Conclusions:In LA-NPC patients,2IC+2CCRT was the optimal choice regarding efficacy,toxicity and costeffectiveness;however,2IC+2CCRT and 3IC+3CCRT probably shortened LRRFS in high-and low-risk populations,respectively.展开更多
The high-quality development of rural finance is an important support for rural revitalization.In recent years,it continuously expands the investment in rural finance in Heilongjiang Province,and optimizes the rural f...The high-quality development of rural finance is an important support for rural revitalization.In recent years,it continuously expands the investment in rural finance in Heilongjiang Province,and optimizes the rural financial service system and mechanism.The overall income level and living conditions of rural residents have been significantly improved,but there still exists income gap between urban and rural residents.Therefore,based on analyzing and combing current situation and problems of rural financial development and urban-rural income gap in Heilongjiang Province,multiple linear regression model is used to study the impact of rural financial development on the income gap between urban and rural residents in Heilongjiang Province.The research results show that the scale of rural financial development in Heilongjiang Province will enlarge the income gap between urban and rural residents,while rural financial development efficiency and urbanization level reduce income gap between urban and rural residents in Heilongjiang Province.Based on the above conclusions,some policy suggestions to promote the equalization of urban and rural income in Heilongjiang Province are puts forward in this paper.展开更多
As the core and foundation of the business ecosystem,the platform determines its structure and operation mode.The research on platform strategy and business ecosystem is receiving more and more attention from all walk...As the core and foundation of the business ecosystem,the platform determines its structure and operation mode.The research on platform strategy and business ecosystem is receiving more and more attention from all walks of life.This paper first provided the concept of a platform-based business ecosystem.Then,on the basis of the platform's"control mode"and"position on the industry chain,it designed four types of construction modes of business ecosystem:open participation,open technology,close symbiosis and channel control.In addition,combined with typical cases,it discussed the structure and operating characteristics of each type of business ecosystem.Finally,it analyzed weak points of this study and made some prospects for future study.展开更多
As an important means for enterprises to promote technological progress,product development and service level,innovation has an absolute role in enhancing enterprises'innovation strength and market strength.In the...As an important means for enterprises to promote technological progress,product development and service level,innovation has an absolute role in enhancing enterprises'innovation strength and market strength.In the context of frequent and rapid product replacement and shortened technological innovation cycle in modern society,through the embedding of social networks,forming platforms for higher education institutions,governments,capital markets,research institutions and intermediary links to promote the integration of innovation and capital development and make the most of every resource has become an important way.From the perspective of social network,the methods and necessary approaches for the establishment of enterprise innovation network are studied in this article.展开更多
Vygotsky and Bruner’s theory,as a significant guidance in the field of education,make a influence for many students and teachers.This paper uses the ways of description and discussion to explore the implication from ...Vygotsky and Bruner’s theory,as a significant guidance in the field of education,make a influence for many students and teachers.This paper uses the ways of description and discussion to explore the implication from Vygotsky and Bruner’s theory on teaching and learning.展开更多
With the progress of technology,learning in the cloud has becoming the new teaching and learning model in education.Compared with the traditional class,it influences on improving academic performance,stimulating learn...With the progress of technology,learning in the cloud has becoming the new teaching and learning model in education.Compared with the traditional class,it influences on improving academic performance,stimulating learning motivation and saving time.However,most changeling of it is increased of dropout.What is more,the feeling of lacking interpersonal communication happened between the teachers and students.展开更多
Teacher plays an essential role in the lives of children.In addition to promoting their learning and improving academic performance,teachers have a major character in developing student’s creative potential and growi...Teacher plays an essential role in the lives of children.In addition to promoting their learning and improving academic performance,teachers have a major character in developing student’s creative potential and growing into responsible citizens.However,in recent years,a report by National Foundation for Educational(2019)claimed that the teacher has faced many challenges than other occupations.Stress is one of the most challenges for the teacher to overcome.The main sources of teacher stress generally come from personal,interpersonal as well as organization.This essay explores and discusses the factors that impact or affect teacher stress,exploring the theories and concepts associated with teacher stress and mitigation practices for teacher stress in the United Kingdom school system-from primary and secondary school.展开更多
Despite recent advances in extrusion bioprinting of cell-laden hydrogels,using nat-urally derived bioinks to biofabricate complex elastic tissues with both satisfying biological functionalities and superior mechanical...Despite recent advances in extrusion bioprinting of cell-laden hydrogels,using nat-urally derived bioinks to biofabricate complex elastic tissues with both satisfying biological functionalities and superior mechanical properties is hitherto an unmet challenge.Here,we address this challenge with precisely designed biological tough hydrogel bioinks featuring a double-network structure.The tough hydrogels con-sisted of energy-dissipative dynamically crosslinked glycosaminoglycan hyaluronic acid(o-nitrobenzyl-grafted hyaluronic acid)and elastin through Schiff’s base reac-tion,and free-radically polymerized gelatin methacryloyl.The incorporation of elastin further improved the elasticity,stretchability(∼170%strain),and tough-ness(∼45 kJ m-3)of the hydrogels due to the random coiling structure.We used this novel class of hydrogel bioinks to bioprint several complex elastic tissues with good shape retention.Furthermore,in vitro and in vivo experiments also demon-strated that the existence of elastin in the biocompatible bioinks facilitated improved cell behaviors and biological functions of bioprinted tissues,such as cell spreading and phenotype maintenance as well as tissue regeneration.The results confirmed the potential of the elastin-containing tough hydrogel bioinks for bioprinting of 3D complex elastic tissues with biological functionalities,which mayfind widespread applications in elastic tissue regeneration.展开更多
Gene expression profiling of new or modified cell lines becomes routine today;however,obtaining comprehensive molecular characterization and cellular responses for a variety of cell lines,including those derived from ...Gene expression profiling of new or modified cell lines becomes routine today;however,obtaining comprehensive molecular characterization and cellular responses for a variety of cell lines,including those derived from underrepresented groups,is not trivial when resources are minimal.Using gene expression to predict other measurements has been actively explored;however,systematic investigation of its predictive power in various measurements has not been well studied.Here,we evaluated commonly used machine learning methods and presented TransCell,a two-step deep transfer learning framework that utilized the knowledge derived from pan-cancer tumor samples to predict molecular features and responses.Among these models,TransCell had the best performance in predicting metabolite,gene effect score(or genetic dependency),and drug sensitivity,and had comparable performance in predicting mutation,copy number variation,and protein expression.Notably,TransCell improved the performance by over 50%in drug sensitivity prediction and achieved a correlation of 0.7 in gene effect score prediction.Furthermore,predicted drug sensitivities revealed potential repurposing candidates for new 100 pediatric cancer cell lines,and predicted gene effect scores reflected BRAF resistance in melanoma cell lines.Together,we investigated the predictive power of gene expression in six molecular measurement types and developed a web portal(http://apps.octad.org/transcell/)that enables the prediction of 352,000 genomic and cellular response features solely from gene expression profiles.展开更多
Growth-and health-promoting bacteria can boost crop productivity in a sustainable way.Pseudomonas simiae WCS417is sucha bacterium that efficiently colonizes roots,modifiesthe architecture of the root systemto increase...Growth-and health-promoting bacteria can boost crop productivity in a sustainable way.Pseudomonas simiae WCS417is sucha bacterium that efficiently colonizes roots,modifiesthe architecture of the root systemto increase its size,and induces systemic resistance to make plants more resistant to pests and pathogens.Our previous work suggested that WCS417-induced phenotypes are controlled by root cell-type-specific mechanisms.However,it remains unclear how WCS417 affects these mechanisms.In this study,we transcriptionally profiled five Arabidopsis thaliana root cell types following WCS417 colonization.We found that the cortex and endodermis have the most differentially expressed genes,even though they are not in direct contact with this epiphytic bacterium.Many of these genes are associated with reduced cell wall biogenesis,and mutant analysis suggests that this downregulation facilitates WCS417-driven root architectural changes.Furthermore,we observed elevated expression of suberin biosynthesis genes and increased deposition of suberin in the endodermis of WCS417-colonized roots.Using an endodermal barrier mutant,we showed the importance of endodermal barrier integrity for optimal plant-beneficial bacterium association.Comparison of the transcriptome profiles in the two epidermal cell types that are in direct contact with WcS417-trichoblasts that form root hairs and atrichoblasts that do not-implies a difference in potential for defense gene activation.While both cell types respond to WCS417,trichoblasts displayed both higher basal and WCS417-dependent activation of defense-related genes compared with atrichoblasts.This suggests that root hairs may activate root immunity,a hypothesis that is supported by differential immune responses in root hair mutants.Taken together,these results highlight the strength of cell-type-specific transcriptional profiling to uncover"masked"biological mechanisms underlying beneficial plant-microbe associations.展开更多
In order to discover structurally new and bioactive conipounds from marine life,we studied the secondary metabolites of the marine-derived fungi associated with a marine sponge(XS-3)from the Xisha islands.As a result,...In order to discover structurally new and bioactive conipounds from marine life,we studied the secondary metabolites of the marine-derived fungi associated with a marine sponge(XS-3)from the Xisha islands.As a result,4-O-methylcandidusin A(1),a new p-terphenyl alcohol,along with nine known analogs(2-10),were isolated and identified from the marine spongederived fungus Aspergillus candidus OUCMDZ-1051.The structures of these compounds were determined by analyzing spectroscopic data,especially ID and 2D NMR.The new compound 1 selectively inhibited the growth of the MDA-MB-46&BT474 and A431 human cancer cell lines with the IC_(50) values of 1.84,6.05 and 0.98 pmol/L,respectively.Compound 1 also displayed a selective antimicrobial activity against Escherichia coli with an MIC value of 27.3 pmol/L.The results indicated 4-O-methylcandidusin A(1)as a potential lead in the new drug discovery for triple negative breast cancer,invasive ductal breast cancer and epidermoid cancer.The antimicrobial metabolites also evidenced a clue for chemical defense of sponges by their associated microorganisms.展开更多
文摘Currently, land resources are becoming more and more constrained and structures are getting closer to each other. To investigate the seismic response of inter-story isolated structure to adjacent structure, models considering no soil-structure interaction (SSI), considering soil-structure interaction (SSI), and considering structure-soil-structure interaction (SSSI) were established. Nonlinear seismic response comparative analysis was conducted by varying the spacing between adjacent structure and inter-story isolated structure, as well as the weight of adjacent structure, under different earthquake inputs, in order to obtain the structural response characteristics. The results indicate that the inter-story drift and inter-story shear of the inter-story isolated structure without considering SSI are smaller than those considering SSI and SSSI. The inter-story drift and inter-story shear of the inter-story isolated structure considering SSSI are further affected compared to that of the inter-story isolated structure considering only SSI. As the spacing between adjacent structure and inter-story isolated structure increases, the influence of adjacent structure on inter-story isolated structure decreases. The variation in the spacing between the two structures has a negligible effect on the isolation layer of the inter-story isolated structure. With the increase in the weight of adjacent structure, the influence of adjacent structure on inter-story isolated structure becomes more significant. The increasing weight of adjacent structure has an increasing effect on the Isolation layer of the inter-story isolated structure.
基金supported by grants from the National Natural Science Foundation of China(No.81872375 and 82172863)the Natural Science Foundation of Guangdong Province(No.2021A1515010118).
文摘objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but not evidence-confirmed.This study aimed to determine the clinical value of 2IC+2CCRT regarding efficacy,toxicity and cost-effectiveness.Methods:This real-world study from two epidemic centers used propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)analyses.The enrolled patients were divided into three groups based on treatment modality:Group A(2IC+2CCRT),Group B(3IC+2CCRT or 2IC+3CCRT)and Group C(3IC+3CCRT).Long-term survival,acute toxicities and cost-effectiveness were compared among the groups.We developed a prognostic model dividing the population into high-and low-risk cohorts,and survivals including overall survival(OS),progression-free survival(PFS),distant metastasis-free survival(DMFS)and locoregional relapse-free survival(LRRFS)were compared among the three groups according to certain risk stratifications.Results:Of 4,042 patients,1,175 were enrolled,with 660,419,and 96 included in Groups A,B and C,respectively.Five-year survivals were similar among the three groups after PSM and confirmed by IPTW.Grade 3-4 neutropenia and leukocytopenia were significantly higher in Groups C and B than in Group A(52.1%vs.41.5%vs.25.2%;41.7%vs.32.7%vs.25.0%)as were grade 3-4 nausea/vomiting and oral mucositis(29.2%vs.15.0%vs.6.1%;32.3%vs.25.3%vs.18.0%).Cost-effective analysis suggested that 2IC+2CCRT was the least expensive,while the health benefits were similar to those of the other groups.Further exploration showed that 2IC+2CCRT tended to be associated with a shorter PFS in high-risk patients,while 3IC+3CCRT potentially contributed to poor PFS in low-risk individuals,mainly reflected by LRRFS.Conclusions:In LA-NPC patients,2IC+2CCRT was the optimal choice regarding efficacy,toxicity and costeffectiveness;however,2IC+2CCRT and 3IC+3CCRT probably shortened LRRFS in high-and low-risk populations,respectively.
基金Supported by General Project of Philosophy and Social Sciences in Heilongjiang Province(18JYB153)Joint Guiding Project of Natural Science Foundation in Heilongjiang Province(LH2019G019).
文摘The high-quality development of rural finance is an important support for rural revitalization.In recent years,it continuously expands the investment in rural finance in Heilongjiang Province,and optimizes the rural financial service system and mechanism.The overall income level and living conditions of rural residents have been significantly improved,but there still exists income gap between urban and rural residents.Therefore,based on analyzing and combing current situation and problems of rural financial development and urban-rural income gap in Heilongjiang Province,multiple linear regression model is used to study the impact of rural financial development on the income gap between urban and rural residents in Heilongjiang Province.The research results show that the scale of rural financial development in Heilongjiang Province will enlarge the income gap between urban and rural residents,while rural financial development efficiency and urbanization level reduce income gap between urban and rural residents in Heilongjiang Province.Based on the above conclusions,some policy suggestions to promote the equalization of urban and rural income in Heilongjiang Province are puts forward in this paper.
基金Project of Natural Science Foundation of Heilongjiang Province(LH2019G019)General Philosophical and Social Science Research Project of Heilongjiang Province(18JYB153).Research Start-up Project of Graduated and Introduced Talents of Heilongjiang Bayi Agricultural University"Research on Cooperation Mechanism and Operation Mode of Large,Small and Medium-sized Enterprises Based on Enterprise Ecosystem".
文摘As the core and foundation of the business ecosystem,the platform determines its structure and operation mode.The research on platform strategy and business ecosystem is receiving more and more attention from all walks of life.This paper first provided the concept of a platform-based business ecosystem.Then,on the basis of the platform's"control mode"and"position on the industry chain,it designed four types of construction modes of business ecosystem:open participation,open technology,close symbiosis and channel control.In addition,combined with typical cases,it discussed the structure and operating characteristics of each type of business ecosystem.Finally,it analyzed weak points of this study and made some prospects for future study.
基金Natural Science Foundation of Heilongjiang Province(LH2019G019)Philosophy and Social Science General Project of Heilongjiang Province(18JYB153)Scientific Research Foundation for Cultivated and Introduced Talents of Heilongjiang Bayi Agricultural University。
文摘As an important means for enterprises to promote technological progress,product development and service level,innovation has an absolute role in enhancing enterprises'innovation strength and market strength.In the context of frequent and rapid product replacement and shortened technological innovation cycle in modern society,through the embedding of social networks,forming platforms for higher education institutions,governments,capital markets,research institutions and intermediary links to promote the integration of innovation and capital development and make the most of every resource has become an important way.From the perspective of social network,the methods and necessary approaches for the establishment of enterprise innovation network are studied in this article.
文摘Vygotsky and Bruner’s theory,as a significant guidance in the field of education,make a influence for many students and teachers.This paper uses the ways of description and discussion to explore the implication from Vygotsky and Bruner’s theory on teaching and learning.
文摘With the progress of technology,learning in the cloud has becoming the new teaching and learning model in education.Compared with the traditional class,it influences on improving academic performance,stimulating learning motivation and saving time.However,most changeling of it is increased of dropout.What is more,the feeling of lacking interpersonal communication happened between the teachers and students.
文摘Teacher plays an essential role in the lives of children.In addition to promoting their learning and improving academic performance,teachers have a major character in developing student’s creative potential and growing into responsible citizens.However,in recent years,a report by National Foundation for Educational(2019)claimed that the teacher has faced many challenges than other occupations.Stress is one of the most challenges for the teacher to overcome.The main sources of teacher stress generally come from personal,interpersonal as well as organization.This essay explores and discusses the factors that impact or affect teacher stress,exploring the theories and concepts associated with teacher stress and mitigation practices for teacher stress in the United Kingdom school system-from primary and secondary school.
基金Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences,Grant/Award Numbers:2021-I2M-1-052,2017-I2M-1-007National Multidisciplinary Cooperative Diagnosis and Treatment Capacity Building Project for Major Diseases,Grant/Award Number:21025National Natural Science Foundation of China,Grant/Award Numbers:82371796,81871575。
文摘Despite recent advances in extrusion bioprinting of cell-laden hydrogels,using nat-urally derived bioinks to biofabricate complex elastic tissues with both satisfying biological functionalities and superior mechanical properties is hitherto an unmet challenge.Here,we address this challenge with precisely designed biological tough hydrogel bioinks featuring a double-network structure.The tough hydrogels con-sisted of energy-dissipative dynamically crosslinked glycosaminoglycan hyaluronic acid(o-nitrobenzyl-grafted hyaluronic acid)and elastin through Schiff’s base reac-tion,and free-radically polymerized gelatin methacryloyl.The incorporation of elastin further improved the elasticity,stretchability(∼170%strain),and tough-ness(∼45 kJ m-3)of the hydrogels due to the random coiling structure.We used this novel class of hydrogel bioinks to bioprint several complex elastic tissues with good shape retention.Furthermore,in vitro and in vivo experiments also demon-strated that the existence of elastin in the biocompatible bioinks facilitated improved cell behaviors and biological functions of bioprinted tissues,such as cell spreading and phenotype maintenance as well as tissue regeneration.The results confirmed the potential of the elastin-containing tough hydrogel bioinks for bioprinting of 3D complex elastic tissues with biological functionalities,which mayfind widespread applications in elastic tissue regeneration.
基金supported by the National Institute of Health(Grant Nos.R01GM134307 and K01 ES028047)the MSU Global Impact Initiative,USA.
文摘Gene expression profiling of new or modified cell lines becomes routine today;however,obtaining comprehensive molecular characterization and cellular responses for a variety of cell lines,including those derived from underrepresented groups,is not trivial when resources are minimal.Using gene expression to predict other measurements has been actively explored;however,systematic investigation of its predictive power in various measurements has not been well studied.Here,we evaluated commonly used machine learning methods and presented TransCell,a two-step deep transfer learning framework that utilized the knowledge derived from pan-cancer tumor samples to predict molecular features and responses.Among these models,TransCell had the best performance in predicting metabolite,gene effect score(or genetic dependency),and drug sensitivity,and had comparable performance in predicting mutation,copy number variation,and protein expression.Notably,TransCell improved the performance by over 50%in drug sensitivity prediction and achieved a correlation of 0.7 in gene effect score prediction.Furthermore,predicted drug sensitivities revealed potential repurposing candidates for new 100 pediatric cancer cell lines,and predicted gene effect scores reflected BRAF resistance in melanoma cell lines.Together,we investigated the predictive power of gene expression in six molecular measurement types and developed a web portal(http://apps.octad.org/transcell/)that enables the prediction of 352,000 genomic and cellular response features solely from gene expression profiles.
基金the Netherlands Organization of Scientific Research through ALW Topsector Grant no.831.14.001(E.H.V.)a postdoctoral fellowship from the Jane Coffin Childs Memorial Fund for Medical Research(L.M.L.)+8 种基金the NIH(5R01-GM-043778),the NSF(MCB-06-18304),the Gordon and Betty Moore Foundation and the Howard Hughes Medical Institute(P.N.B.)a postdoctoral fellowship from the Research Foundation Flanders(FWO 12B8116N)(R.d.J.)the NWO Green II Grant no.ALWGR.2017.002(R.d.J.)the Novo Nordisk Foundation Grant no.NNF19SA0059362(R.d.J.)the China Scholarship Council(CSC)scholarship no.201908320054(J.Z.)scholarship no.202006990074(J.Y.)the Technology Foundation Perspective Program Back2Roots grant no.14219(C.M.J.P.)the ERC Advanced Grant no.269072 of the European Research Council(C.M.J.P.)the NWO Gravitation Grant no.024.004.014(1.A.S.and C.M.J.).
文摘Growth-and health-promoting bacteria can boost crop productivity in a sustainable way.Pseudomonas simiae WCS417is sucha bacterium that efficiently colonizes roots,modifiesthe architecture of the root systemto increase its size,and induces systemic resistance to make plants more resistant to pests and pathogens.Our previous work suggested that WCS417-induced phenotypes are controlled by root cell-type-specific mechanisms.However,it remains unclear how WCS417 affects these mechanisms.In this study,we transcriptionally profiled five Arabidopsis thaliana root cell types following WCS417 colonization.We found that the cortex and endodermis have the most differentially expressed genes,even though they are not in direct contact with this epiphytic bacterium.Many of these genes are associated with reduced cell wall biogenesis,and mutant analysis suggests that this downregulation facilitates WCS417-driven root architectural changes.Furthermore,we observed elevated expression of suberin biosynthesis genes and increased deposition of suberin in the endodermis of WCS417-colonized roots.Using an endodermal barrier mutant,we showed the importance of endodermal barrier integrity for optimal plant-beneficial bacterium association.Comparison of the transcriptome profiles in the two epidermal cell types that are in direct contact with WcS417-trichoblasts that form root hairs and atrichoblasts that do not-implies a difference in potential for defense gene activation.While both cell types respond to WCS417,trichoblasts displayed both higher basal and WCS417-dependent activation of defense-related genes compared with atrichoblasts.This suggests that root hairs may activate root immunity,a hypothesis that is supported by differential immune responses in root hair mutants.Taken together,these results highlight the strength of cell-type-specific transcriptional profiling to uncover"masked"biological mechanisms underlying beneficial plant-microbe associations.
基金This work is supported by the National Natural Science Foundation of China(NSFC)(Nos.U1906213,41876172.and U1606403).
文摘In order to discover structurally new and bioactive conipounds from marine life,we studied the secondary metabolites of the marine-derived fungi associated with a marine sponge(XS-3)from the Xisha islands.As a result,4-O-methylcandidusin A(1),a new p-terphenyl alcohol,along with nine known analogs(2-10),were isolated and identified from the marine spongederived fungus Aspergillus candidus OUCMDZ-1051.The structures of these compounds were determined by analyzing spectroscopic data,especially ID and 2D NMR.The new compound 1 selectively inhibited the growth of the MDA-MB-46&BT474 and A431 human cancer cell lines with the IC_(50) values of 1.84,6.05 and 0.98 pmol/L,respectively.Compound 1 also displayed a selective antimicrobial activity against Escherichia coli with an MIC value of 27.3 pmol/L.The results indicated 4-O-methylcandidusin A(1)as a potential lead in the new drug discovery for triple negative breast cancer,invasive ductal breast cancer and epidermoid cancer.The antimicrobial metabolites also evidenced a clue for chemical defense of sponges by their associated microorganisms.
