Concerns about the durability of transportation infrastructure due to freeze-thaw(F-T)cycles are particu-larly significant in the Chinese plateau region,where concrete aging and performance deterioration pose substant...Concerns about the durability of transportation infrastructure due to freeze-thaw(F-T)cycles are particu-larly significant in the Chinese plateau region,where concrete aging and performance deterioration pose substantial challenges.The current national standards for the frost resistance design of concrete struc-tures are based predominantly on the coldest monthly average temperature and do not adequately address the comprehensive effects of the spatiotemporal variance,amplitude,and frequency of F-T cycles.To address this issue,this study introduced a spatiotemporal distribution model to analyze the long-term impact of F-T action on concrete structures by employing statistical analysis and spatial inter-polation techniques.Cluster analysis was applied to create a nationwide zonation of F-T action level from data on the freezing temperature,temperature difference,and the number of F-T cycles.Furthermore,this study explored the similarity between natural environmental conditions and laboratory-accelerated tests using hydraulic pressure and cumulative damage theories.A visualization platform that incorporates tools for meteorological data queries,environmental characteristic analyses,and F-T action similarity calculations was designed.This research lays theoretical groundwork and provides technical guidance for assessing service life and enhancing the quantitative durability design of concrete structures in the Chinese plateau region.展开更多
Background:Pulmonary blastoma(PB)is a rare subtype of lung cancer.Currently,the underlying pathogenesis mechanisms of PB have not been fully illustrated,and the therapeutic approach for this entity is limited.Methods:...Background:Pulmonary blastoma(PB)is a rare subtype of lung cancer.Currently,the underlying pathogenesis mechanisms of PB have not been fully illustrated,and the therapeutic approach for this entity is limited.Methods:Whole-exome sequencing(WES),RNA sequencing,and DNA methylation profiling are applied to seven PB patients.Multi-omics data of pulmonary sarcomatoid carcinoma(PSC)and pituitary blastoma(PitB)from previous studies are invoked to illuminate the associations among PB and these malignacies.Results:We portray the genomic alteration spectrum of PB and find that DICER1 is with the highest alteration rate(86%).We uncover that DICER1 alterations,Wnt signaling pathway dysregulation and IGF2 imprinting dysregulation are the potential pathogenesis mechanisms of PB.Moreover,we reveal that the integrated molecular features of PB are distinct from PSC,and the molecular characteristics of PB are more similar to PitB than to PSC.Pancancer analysis show that the tumor mutation burden(TMB)and leukocyte fraction(LF)of PB are low,while some cases are positive for PD-L1 or have CD8-positive focal areas,implying the potential applicability of immunotherapy in selected PB patients.Conclusion:This study depicts the integrated molecular characteristics of PB and offers novel insights into the pathogenesis and therapeutic strategies of PB.展开更多
Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics.To increase the oxytetracycline(OTC) production in Streptomyces rimosus,we investigated the coope...Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics.To increase the oxytetracycline(OTC) production in Streptomyces rimosus,we investigated the cooperative effect of three co-overexpressing OTC resistance genes:one gene encodes a ribosomal protection protein(otrA) and the other two express efflux proteins(otrB and otrC).Results indicated that combinational overexpression of otrA,otrB,and otrC(MKABC) exerted a synergetic effect.OTC production increased by 179%in the recombinant strain compared with that of the wild-type strain M4018.The resistance level to OTC was increased by approximately two-fold relative to the parental strain,thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production.Furthermore,the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC;such strain can produce OTC of approximately7.49 g L^((-1)),which represents an increase of 19%in comparison with that of the OtcR-overexpressing strain alone.Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.展开更多
Chemical functionalization is an effective approach to address interfacial deterioration caused by environmental exposure in cellulose nanofiber(CNF)-epoxy nanocomposites.However,how functionalization affects interfac...Chemical functionalization is an effective approach to address interfacial deterioration caused by environmental exposure in cellulose nanofiber(CNF)-epoxy nanocomposites.However,how functionalization affects interfacial deterioration and durability of nanocomposites in erosive environment is still lacked.In this work,the global mechanical properties and local interfacial intermolecular behavior of pristine and functionalized CNF-reinforced nanocomposites are investigated through molecular dynamics simulations.The results show that functionalization can enhance the interfacial energy barrier and debonding stress by 43%and 57%,respectively.Functionalized CNF inhibits the slippage of epoxy chains,ensuring better interfacial adhesion and efficient stress transfer between fiber and matrix.Functional groups promote the formation of interfacial bridging and topological structures and weaken the hydrogen bonding ability of water molecules,leading to stronger intermolecular adsorption effect and better interfacial integrity.The epoxy molecular configuration evolution and intermolecular interactions,caused by the functionalization of CNF in the interfacial region,enhance the interfacial erosion resistance,contributing to the durability of the nanocomposites.This study reveals the in-depth interfacial deterioration mechanism of functionalized nanocomposites under erosive environment,inspiring a novel strategy for the design of durable CNF-reinforced nanocomposites.展开更多
基金supported by the National Key Research and Development Program of China(2021YFF0500801)the Joint Funds of the National Natural Science Foundation of China(U23A20658)the National Natural of China(52025081).
文摘Concerns about the durability of transportation infrastructure due to freeze-thaw(F-T)cycles are particu-larly significant in the Chinese plateau region,where concrete aging and performance deterioration pose substantial challenges.The current national standards for the frost resistance design of concrete struc-tures are based predominantly on the coldest monthly average temperature and do not adequately address the comprehensive effects of the spatiotemporal variance,amplitude,and frequency of F-T cycles.To address this issue,this study introduced a spatiotemporal distribution model to analyze the long-term impact of F-T action on concrete structures by employing statistical analysis and spatial inter-polation techniques.Cluster analysis was applied to create a nationwide zonation of F-T action level from data on the freezing temperature,temperature difference,and the number of F-T cycles.Furthermore,this study explored the similarity between natural environmental conditions and laboratory-accelerated tests using hydraulic pressure and cumulative damage theories.A visualization platform that incorporates tools for meteorological data queries,environmental characteristic analyses,and F-T action similarity calculations was designed.This research lays theoretical groundwork and provides technical guidance for assessing service life and enhancing the quantitative durability design of concrete structures in the Chinese plateau region.
基金supported by National Natural Sciences Foundation(grant number:82203827).
文摘Background:Pulmonary blastoma(PB)is a rare subtype of lung cancer.Currently,the underlying pathogenesis mechanisms of PB have not been fully illustrated,and the therapeutic approach for this entity is limited.Methods:Whole-exome sequencing(WES),RNA sequencing,and DNA methylation profiling are applied to seven PB patients.Multi-omics data of pulmonary sarcomatoid carcinoma(PSC)and pituitary blastoma(PitB)from previous studies are invoked to illuminate the associations among PB and these malignacies.Results:We portray the genomic alteration spectrum of PB and find that DICER1 is with the highest alteration rate(86%).We uncover that DICER1 alterations,Wnt signaling pathway dysregulation and IGF2 imprinting dysregulation are the potential pathogenesis mechanisms of PB.Moreover,we reveal that the integrated molecular features of PB are distinct from PSC,and the molecular characteristics of PB are more similar to PitB than to PSC.Pancancer analysis show that the tumor mutation burden(TMB)and leukocyte fraction(LF)of PB are low,while some cases are positive for PD-L1 or have CD8-positive focal areas,implying the potential applicability of immunotherapy in selected PB patients.Conclusion:This study depicts the integrated molecular characteristics of PB and offers novel insights into the pathogenesis and therapeutic strategies of PB.
基金supported by funding from Shengxue Dacheng Pharmaceutical Co.,Ltd,National Natural Science Foundation of China(31400034 and 31570031)the Ministry of Science and Technology of China(2013CB734001)
文摘Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics.To increase the oxytetracycline(OTC) production in Streptomyces rimosus,we investigated the cooperative effect of three co-overexpressing OTC resistance genes:one gene encodes a ribosomal protection protein(otrA) and the other two express efflux proteins(otrB and otrC).Results indicated that combinational overexpression of otrA,otrB,and otrC(MKABC) exerted a synergetic effect.OTC production increased by 179%in the recombinant strain compared with that of the wild-type strain M4018.The resistance level to OTC was increased by approximately two-fold relative to the parental strain,thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production.Furthermore,the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC;such strain can produce OTC of approximately7.49 g L^((-1)),which represents an increase of 19%in comparison with that of the OtcR-overexpressing strain alone.Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.
基金supported by the National Key Research and Development Program of China(No.2021YFF0500802)the National Science Fund for Distinguished Young Scholars(No.52025081)+2 种基金Key Research and Development Program of Guangdong Province(No.2019B111107001)Shenzhen Science and Technology Programs(No.RCBS20200714114819352)Foundation for Distinguished Young Talents in Higher Education of Guangdong(No.2021KQNCX096).
文摘Chemical functionalization is an effective approach to address interfacial deterioration caused by environmental exposure in cellulose nanofiber(CNF)-epoxy nanocomposites.However,how functionalization affects interfacial deterioration and durability of nanocomposites in erosive environment is still lacked.In this work,the global mechanical properties and local interfacial intermolecular behavior of pristine and functionalized CNF-reinforced nanocomposites are investigated through molecular dynamics simulations.The results show that functionalization can enhance the interfacial energy barrier and debonding stress by 43%and 57%,respectively.Functionalized CNF inhibits the slippage of epoxy chains,ensuring better interfacial adhesion and efficient stress transfer between fiber and matrix.Functional groups promote the formation of interfacial bridging and topological structures and weaken the hydrogen bonding ability of water molecules,leading to stronger intermolecular adsorption effect and better interfacial integrity.The epoxy molecular configuration evolution and intermolecular interactions,caused by the functionalization of CNF in the interfacial region,enhance the interfacial erosion resistance,contributing to the durability of the nanocomposites.This study reveals the in-depth interfacial deterioration mechanism of functionalized nanocomposites under erosive environment,inspiring a novel strategy for the design of durable CNF-reinforced nanocomposites.
