Acoustic emission and digital image correlation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard composite laminated rock masses(SHCLRM)containing double fissures und...Acoustic emission and digital image correlation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard composite laminated rock masses(SHCLRM)containing double fissures under uniaxial compression.The effects of different rock combination methods and prefabricated fissures with different orientations on mechanical properties and crack coalescence patterns were analyzed.The characteristics of the acoustic emission source location distribution,and frequency changes of the crack evolution process were also investigated.The test results show that the damage mode of SHCLRM is related to the combination mode of rock layers and the orientation of fractures.Hard layers predominantly produce tensile cracks;soft layers produce shear cracks.The first crack always sprouts at the tip or middle of prefabricated fractures in hard layers.The acoustic emission signal of SHCLRM with double fractures has clear stage characteristics,and the state of crack development can be inferred from this signal to provide early warning for rock fracture instability.This study can provide a reference for the assessment of the fracture development status between adjacent roadways in SHCLRM in underground mines,as well as in roadway layout and support.展开更多
Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications.However,motor systems composed by organism-derived organics that maximize the therapeutic ef...Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications.However,motor systems composed by organism-derived organics that maximize the therapeutic efficacy of enzymatic products remain challenging.Herein,swimming proteomotors based on biocompatible urease and human serum albumin are constructed for enhanced antitumor therapy via active motion and ammonia amplification.By decomposing urea into carbon dioxide and ammonia,the designed proteomotors are endowed with self-propulsive capability,which leads to improved internalization and enhanced penetration in vitro.As a glutamine synthetase inhibitor,the loaded L-methionine sulfoximine further prevents the conversion of toxic ammonia into non-toxic glutamine in both tumor and stromal cells,resulting in local ammonia amplification.After intravesical instillation,the proteomotors achieve longer bladder retention and thus significantly inhibit the growth of orthotopic bladder tumor in vivo without adverse effects.We envision that the as-developed swimming proteomotors with amplification of the product toxicity may be a potential platform for active cancer treatment.展开更多
基金This study was supported by the Natural Science Foundation of Hubei Province(No.2020CFB123)the Scientific Research Program of Hubei Education Department(No.Q20201109).
文摘Acoustic emission and digital image correlation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard composite laminated rock masses(SHCLRM)containing double fissures under uniaxial compression.The effects of different rock combination methods and prefabricated fissures with different orientations on mechanical properties and crack coalescence patterns were analyzed.The characteristics of the acoustic emission source location distribution,and frequency changes of the crack evolution process were also investigated.The test results show that the damage mode of SHCLRM is related to the combination mode of rock layers and the orientation of fractures.Hard layers predominantly produce tensile cracks;soft layers produce shear cracks.The first crack always sprouts at the tip or middle of prefabricated fractures in hard layers.The acoustic emission signal of SHCLRM with double fractures has clear stage characteristics,and the state of crack development can be inferred from this signal to provide early warning for rock fracture instability.This study can provide a reference for the assessment of the fracture development status between adjacent roadways in SHCLRM in underground mines,as well as in roadway layout and support.
基金supported by the National Natural Science Foundation of China(22175083,51973241,31900567 and 82102051)the Guangzhou Basic and Applied Basic Research Foundation(202201011078)。
文摘Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications.However,motor systems composed by organism-derived organics that maximize the therapeutic efficacy of enzymatic products remain challenging.Herein,swimming proteomotors based on biocompatible urease and human serum albumin are constructed for enhanced antitumor therapy via active motion and ammonia amplification.By decomposing urea into carbon dioxide and ammonia,the designed proteomotors are endowed with self-propulsive capability,which leads to improved internalization and enhanced penetration in vitro.As a glutamine synthetase inhibitor,the loaded L-methionine sulfoximine further prevents the conversion of toxic ammonia into non-toxic glutamine in both tumor and stromal cells,resulting in local ammonia amplification.After intravesical instillation,the proteomotors achieve longer bladder retention and thus significantly inhibit the growth of orthotopic bladder tumor in vivo without adverse effects.We envision that the as-developed swimming proteomotors with amplification of the product toxicity may be a potential platform for active cancer treatment.
