Objective:Endometrial tuberculosis,which commonly affects women of reproductive age,is a significant cause of intrauterine adhesions(IUA),potentially leading to hypomenorrhea,amenorrhea,and infertility.Hysteroscopic a...Objective:Endometrial tuberculosis,which commonly affects women of reproductive age,is a significant cause of intrauterine adhesions(IUA),potentially leading to hypomenorrhea,amenorrhea,and infertility.Hysteroscopic adhesiolysis is the primary treatment for IUA;however,studies specifically addressing its efficacy in tuberculosisinduced IUA remain scarce.This study aims to evaluate the therapeutic outcomes of hysteroscopic adhesiolysis for IUA caused by endometrial tuberculosis.Methods:This retrospective cohort study included patients diagnosed with tuberculosisinduced IUA who underwent hysteroscopic adhesiolysis at the Third Xiangya Hospital of Central South University between May 2014 and October 2022.Clinical data including age,medical history,adhesion severity,surgical treatment,and reproductive outcomes were analyzed.Results:Among 39 patients identified,2 were lost to follow-up.A total of 37 patients were included,with a follow-up duration ranging from 6 months to 9 years.Hypomenorrhea was reported in 24(64.9%)patients,secondary amenorrhea in 10(27.0%)patients,and normal menstruation in 3(8.1%)patients.Most patients presented with primary infertility(59.5%),and only 2(5.4%)had secondary infertility.The median American Fertility Society(AFS)score at initial assessment was 10(range,8−12);8(21.6%)patients had moderate IUA,and 29(78.4%)had severe IUA.A total of 86 surgical procedures were performed across 37 patients,with 27 patients undergoing 2 or more surgeries.Postoperatively,25(67.6%)patients achieved normalization of the uterine cavity,while 12(32.4%)still had a reduced cavity.Only 7(18.9%)patients had a grossly normal endometrium at the final surgery,all of whom had moderate adhesions at the initial procedure.Menstrual flow returned to normal in 12(32.4%)patients,while 25(67.6%)continued to experience hypomenorrhea.Of 29 patients who attempted in vitro fertilization and embryo transfer(IVF-ET),only 6(20.7%)conceived.Among these,4(13.8%)delivered at term via cesarean section;one case was complicated by postpartum hemorrhage due to uterine atony and another by placental adhesion.Conclusion:Endometrial tuberculosis can lead to severe IUA.Hysteroscopic adhesiolysis facilitates cavity restoration and improvement of menstrual conditions,but the overall reproductive outcomes remain suboptimal.展开更多
Large-area two-dimensional(2D)materials,such as graphene,MoS_(2),WS_(2),h-BN,black phosphorus,and MXenes,are a class of advanced materials with many possible applications.Different applications need different substrat...Large-area two-dimensional(2D)materials,such as graphene,MoS_(2),WS_(2),h-BN,black phosphorus,and MXenes,are a class of advanced materials with many possible applications.Different applications need different substrates,and each substrate may need a different way of transferring the 2D material onto it.Problems such as local stress concentrations,an uneven surface tension,inconsistent adhesion,mechanical damage and contamination during the transfer can adversely affect the quality and properties of the transferred material.Therefore,how to improve the integrity,flatness and cleanness of large area 2D materials is a challenge.In order to achieve high-quality transfer,the main concern is to control the interface adhesion between the substrate,the 2D material and the transfer medium.This review focuses on this topic,and finally,in order to promote the industrial use of large area 2D materials,provides a recipe for this transfer process based on the requirements of the application,and points out the current problems and directions for future development.展开更多
Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on ...The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on untangling the underlying impact of varying adhesive cohesive or adhesion properties is limited and sometimes appears to provide conflicting conclusions.Comparison between the available studies is also often difficult due to variations in armour systems or ballistic testing being conducted.This review scrutinises the available research,identifying six critical properties of an adhesive layer in determining ballistic performance:elastic modulus,fracture strain,acoustic impedance,tensile bond strength,shear bond strength,and thickness.The impact of each of these properties on ballistic performance is discussed in detail,with clear description of the underlying processes involved,allowing clear optimisation goals to be established depending on the ceramic armour specification.展开更多
Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is propo...Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is proposed as a substituting method.By absorbing high energy of the 1064 nm pulsed laser, the paint is vaporized quickly.The ablated debris is then collected by using a suction pump.Initial metal surface of the steel is exposed when laser beam irradiates perpendicularly and scans over it.The cleaned surface fulfills the requirements of surface preparation standards ISO 8501 of SA2.The adhesion is further characterized with pull-off test after carrying out painting with Jotamastic 87 aluminum paint.The repainting can be embedded onto the laser cleaned surface to bond much more tightly.The excellent adhesion strength of 20 MPa between repainted coating and the substrate is achieved, which is higher than what is required by shipyards applications.展开更多
The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic ...The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic accidents were presented.The results show that the adhesion coefficient is a function with the extreme value.If there is atmospheric pressure in the tire,the load of the vehicle and the degree of the coarse on the road surface is not selected properly,it will reach the least and affect the safety of the running automobile.展开更多
The synthetic method of nickel borate acylate (NBA), a kind of rubber steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. The preparation of nickel carbonate coul...The synthetic method of nickel borate acylate (NBA), a kind of rubber steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. The preparation of nickel carbonate could be performed through reaction of nickel sulfate with sodium carbonate in aqueous solution, in which fractional conversion of nickel was more than 99.9%. The mixed nickel carboxylate was prepared by the reaction of nickel carbonate with isooctanoic acid and acetic acid, under strong stirring for 2 h, the mole ratio of these chemicals were 1∶1∶1.1 respectively, and water should be removed completely by adding of inert organic solvent after reaction was finished so as to avoid hydrolysis of tributyl borate in the second reaction. NBA was synthesized by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200 250 ℃ for 6 h. By detection and comparison with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate was very similar to product 680C in IR data, 300% fixed extension strength, tensile strength, hardness and cure curve, and was slightly lower than those of product 680C in tensile failure extensibility and hot air aging. The experimental results show that the prepared NBA can be used as rubber steel cord AP.展开更多
The adhesion between the mining machine and the deep-sea sediments will significantly affect the driving performance of the mining machine in the deep-sea environment.When the mining machine and the deep-sea sediment ...The adhesion between the mining machine and the deep-sea sediments will significantly affect the driving performance of the mining machine in the deep-sea environment.When the mining machine and the deep-sea sediment interaction simulation was carried out,the accuracy of the particle interaction parameters will directly affect the simulation results.This study proposed a method to systematically calibrate the interaction parameters between deep-sea sediment and grouser through the combination of experiment and simulation.The uniaxial compression test and macro adhesion test and corresponding discrete element numerical simulation were carried out,modifying the contact parameters until the simulation results are close to the experimental results.Then the micro-parameters of the JKR adhesion contact model were back calibrated with the test results,and the contact parameters between soil particle-soil particle and soil particle-metal are calibrated.Besides,the adhesion test shows that the adhesion forces were ranked in the order of 5052<STi80<TA2<TC4 under the same surface roughness,which indicates the aluminum alloy 5052 has the best anti-adhesion performance.The relationship between surface adhesion force and microscopic contact parameters was studied by discrete element numerical simulation,and the result shows that the coefficient of static friction and the coefficient of rolling friction has little effect on adhesion force.While it is mainly affected by the coefficient of restitution and surface energy,the surface adhesion force tends to decrease with the increase of the coefficient of restitution and increase with the growth of surface energy.The obtained parameters of soil particle to soil particle and soil particle to metal affecting the adhesion can contribute to the design optimization for the grouser of mining machines to decrease surface adhesion and enhance its movability and mining efficiency.展开更多
Integrins are heterodimeric cell surface receptors that bind to ligands on another cell,e.g.intercellular adhesion molecule 1(ICAM-1),or the extracellular matrix.Integrins play an important role in immune system,and t...Integrins are heterodimeric cell surface receptors that bind to ligands on another cell,e.g.intercellular adhesion molecule 1(ICAM-1),or the extracellular matrix.Integrins play an important role in immune system,and they participate in inflammation,thrombosis,and proliferation,migration and apoptosis of tumor cells.They mediate adhesion and transduce signals across the membrane usually under the influence of forces.A recent study has shown that integrins bind and activate transforming growth factorβisoform(TGF-β)which is involved in tumor suppression and growth,and blocking the binding of TGF-βto integrin can inhibit tumor growth.RGD(arginine-glycine-aspartate)small peptide,which competitively inhibits ligand binding to integrins,has been approved as an injectable drug.However,when the RGD is used to block cancer-related extracellular signaling pathways,it will also cause activation of integrins for a period,and stimulate the transduction of intracellular signals constantly.Therefore,it is necessary to explore for new drugs that can selectively control conformational state of integrins without activating or blocking all of them.In this study,we selected two small peptides,KQAGDV and RTDLDSLRT,that combined with integrins and do not contain an RGD sequence.The non-RGD polypeptide RTDLDSLRT has been reported to have a binding site with integrins and the binding affinity is on nanomolar scale.For the motif of the fibrinogen y chain C-terminal KQAGDV,it can adhere to the head of the integrins.The micropipette aspiration technique and electron microscopy techniques were used to study the adhesion and activation of integrins by peptides,respectively.Micropipette aspiration technique was used to investigate the adhesion frequency of peptide and integrin on Jurkat cell.The pressure system was used to supply a controllable negative pression to the microtube,and two micropipettes were used to absorb red blood cells and Jurkat cells,respectively.The red blood cells were coated with small peptides and can serve as a force sensor after being sucked when two cells were connected.The binding kinetics of integrin and peptides interactions was determined by fitting the curves constructed using adhesion probability between two cells as a function of time.The curves were fitted using a small system probabilistic kinetic model to estimate a pair of kinetic parameters,including the zero force reverse rate kr0,and the cellular binding affinity Acmrm1Ka0.The adhesion frequency yielded P(t)=75%and 57%for RGD and KQAG DV peptides,respectively.We obtained Acmrm1Ka0=1.40 and kr0=0.32 s-1,for RGD,and Acmrm1Ka0=0.85 and kr0=0.54 s-1 for KQAGDV.The RGD peptide has a higher adhesion frequency and lower dissociation rate than the KQAGDV peptide.Electron microscopy techniques was used to observe the activation of integrins by peptides.Jurkat cell expressing integrins was bound to a magnetic bead and bottom plate which were coated with different integrin-binding peptides.Then,we manipulated the beads in a controlled direction by changing the magnetic field nearby,and the forces were applied to the cell.The target cells were fixed and then observed by scanning electron microscope or transmission electron microscope.Jurkat cells contain abundant flexible microvilli of which there are many parallel bundles of actin filaments inside.By electron microscopy analysis,the cell connected with magnetic bead coated with RGD were found to be protruded and the size of microvilli increased up to#-fold of the length of the KQAGDV sample.The microvilli exhibited a curved agglomerate structure under a force-free condition.Moreover,a higher proportion of cells were activated in the presence of RGD than KQAGDV.In conclusion,the binding affinity of KQAGDV to integrin is weaker than RGD,and KQAGDV can bind with integrins effectively with a lower activated proportion.Our results indicate the peptides may selectively bind to integrins without activating them.展开更多
The size mismatch in an end-to-end vascular anastomosis between the host vessel and the graft may cause flow disturbance and predispose to thrombosis [1].Although a number of techniques have been employed to reduce th...The size mismatch in an end-to-end vascular anastomosis between the host vessel and the graft may cause flow disturbance and predispose to thrombosis [1].Although a number of techniques have been employed to reduce the risk of anastomotic thrombosis due to the size mismatch。展开更多
Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some ...Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some pathologic conditions.However,the law of展开更多
In response to current development of materials in nano-science.characterisation of thin coating adhesion ona nano-scale becomes one of the most important research areas,as new coatings get ever thinner and more techn...In response to current development of materials in nano-science.characterisation of thin coating adhesion ona nano-scale becomes one of the most important research areas,as new coatings get ever thinner and more technologically advanced.With a review of technology and mechanisms of evaluating the adhesion failure of coatings.three techniques,nano-im-pact,nano-scratch and nano-indentation techniques,for charactering the adhesion of thin coatings on a nano scale are described.Results of charactering the adhesion faliure of thin coatings using three different techniques indicate that the nano scratch and nano-indentation techniques are very useful tools particularly in charactering the performance of thin coatings under nano-abra sive wear conditions.However,results from these types of tests cannot be easily applied to predict the performance of coatings whose are subject to nano-erosive wear,cyclic nano-fatigue or multiple nano-impacts during service.Instead,results of the new dynamic testing technique。展开更多
基金supported by the Wisdom Accumulation and Talent Cultivation Project of Third Xiangya Hosipital of Central South University,China(YX202112).
文摘Objective:Endometrial tuberculosis,which commonly affects women of reproductive age,is a significant cause of intrauterine adhesions(IUA),potentially leading to hypomenorrhea,amenorrhea,and infertility.Hysteroscopic adhesiolysis is the primary treatment for IUA;however,studies specifically addressing its efficacy in tuberculosisinduced IUA remain scarce.This study aims to evaluate the therapeutic outcomes of hysteroscopic adhesiolysis for IUA caused by endometrial tuberculosis.Methods:This retrospective cohort study included patients diagnosed with tuberculosisinduced IUA who underwent hysteroscopic adhesiolysis at the Third Xiangya Hospital of Central South University between May 2014 and October 2022.Clinical data including age,medical history,adhesion severity,surgical treatment,and reproductive outcomes were analyzed.Results:Among 39 patients identified,2 were lost to follow-up.A total of 37 patients were included,with a follow-up duration ranging from 6 months to 9 years.Hypomenorrhea was reported in 24(64.9%)patients,secondary amenorrhea in 10(27.0%)patients,and normal menstruation in 3(8.1%)patients.Most patients presented with primary infertility(59.5%),and only 2(5.4%)had secondary infertility.The median American Fertility Society(AFS)score at initial assessment was 10(range,8−12);8(21.6%)patients had moderate IUA,and 29(78.4%)had severe IUA.A total of 86 surgical procedures were performed across 37 patients,with 27 patients undergoing 2 or more surgeries.Postoperatively,25(67.6%)patients achieved normalization of the uterine cavity,while 12(32.4%)still had a reduced cavity.Only 7(18.9%)patients had a grossly normal endometrium at the final surgery,all of whom had moderate adhesions at the initial procedure.Menstrual flow returned to normal in 12(32.4%)patients,while 25(67.6%)continued to experience hypomenorrhea.Of 29 patients who attempted in vitro fertilization and embryo transfer(IVF-ET),only 6(20.7%)conceived.Among these,4(13.8%)delivered at term via cesarean section;one case was complicated by postpartum hemorrhage due to uterine atony and another by placental adhesion.Conclusion:Endometrial tuberculosis can lead to severe IUA.Hysteroscopic adhesiolysis facilitates cavity restoration and improvement of menstrual conditions,but the overall reproductive outcomes remain suboptimal.
基金the National Key R&D Program of China(2022YFA1505200)the National Natural Science Foundation of China(22472140,22021001)the Fundamental Research Funds for the Central Universities(20720210017 and 20720210009)。
文摘Large-area two-dimensional(2D)materials,such as graphene,MoS_(2),WS_(2),h-BN,black phosphorus,and MXenes,are a class of advanced materials with many possible applications.Different applications need different substrates,and each substrate may need a different way of transferring the 2D material onto it.Problems such as local stress concentrations,an uneven surface tension,inconsistent adhesion,mechanical damage and contamination during the transfer can adversely affect the quality and properties of the transferred material.Therefore,how to improve the integrity,flatness and cleanness of large area 2D materials is a challenge.In order to achieve high-quality transfer,the main concern is to control the interface adhesion between the substrate,the 2D material and the transfer medium.This review focuses on this topic,and finally,in order to promote the industrial use of large area 2D materials,provides a recipe for this transfer process based on the requirements of the application,and points out the current problems and directions for future development.
文摘Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
基金funding for this research was provided by Netherlands Ministry of Defence
文摘The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on untangling the underlying impact of varying adhesive cohesive or adhesion properties is limited and sometimes appears to provide conflicting conclusions.Comparison between the available studies is also often difficult due to variations in armour systems or ballistic testing being conducted.This review scrutinises the available research,identifying six critical properties of an adhesive layer in determining ballistic performance:elastic modulus,fracture strain,acoustic impedance,tensile bond strength,shear bond strength,and thickness.The impact of each of these properties on ballistic performance is discussed in detail,with clear description of the underlying processes involved,allowing clear optimisation goals to be established depending on the ceramic armour specification.
基金supported by the National Natural Science Foundation of China (U1609209)National Natural Science Foundation of China (61605162)+2 种基金NSFC-Liaoning Province united foundation (U1608259)National Natural Science Foundation of China (51501219)the financial support from the China Scholarship Council
文摘Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is proposed as a substituting method.By absorbing high energy of the 1064 nm pulsed laser, the paint is vaporized quickly.The ablated debris is then collected by using a suction pump.Initial metal surface of the steel is exposed when laser beam irradiates perpendicularly and scans over it.The cleaned surface fulfills the requirements of surface preparation standards ISO 8501 of SA2.The adhesion is further characterized with pull-off test after carrying out painting with Jotamastic 87 aluminum paint.The repainting can be embedded onto the laser cleaned surface to bond much more tightly.The excellent adhesion strength of 20 MPa between repainted coating and the substrate is achieved, which is higher than what is required by shipyards applications.
文摘The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic accidents were presented.The results show that the adhesion coefficient is a function with the extreme value.If there is atmospheric pressure in the tire,the load of the vehicle and the degree of the coarse on the road surface is not selected properly,it will reach the least and affect the safety of the running automobile.
文摘The synthetic method of nickel borate acylate (NBA), a kind of rubber steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. The preparation of nickel carbonate could be performed through reaction of nickel sulfate with sodium carbonate in aqueous solution, in which fractional conversion of nickel was more than 99.9%. The mixed nickel carboxylate was prepared by the reaction of nickel carbonate with isooctanoic acid and acetic acid, under strong stirring for 2 h, the mole ratio of these chemicals were 1∶1∶1.1 respectively, and water should be removed completely by adding of inert organic solvent after reaction was finished so as to avoid hydrolysis of tributyl borate in the second reaction. NBA was synthesized by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200 250 ℃ for 6 h. By detection and comparison with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate was very similar to product 680C in IR data, 300% fixed extension strength, tensile strength, hardness and cure curve, and was slightly lower than those of product 680C in tensile failure extensibility and hot air aging. The experimental results show that the prepared NBA can be used as rubber steel cord AP.
基金Project(12072309)supported by the National Natural Science Foundation of ChinaProject(19B546)supported by the Education Department Foundation of Hunan Province,ChinaProject(2019RS1059)supported by the Hunan Innovative Province Construction Project,China。
文摘The adhesion between the mining machine and the deep-sea sediments will significantly affect the driving performance of the mining machine in the deep-sea environment.When the mining machine and the deep-sea sediment interaction simulation was carried out,the accuracy of the particle interaction parameters will directly affect the simulation results.This study proposed a method to systematically calibrate the interaction parameters between deep-sea sediment and grouser through the combination of experiment and simulation.The uniaxial compression test and macro adhesion test and corresponding discrete element numerical simulation were carried out,modifying the contact parameters until the simulation results are close to the experimental results.Then the micro-parameters of the JKR adhesion contact model were back calibrated with the test results,and the contact parameters between soil particle-soil particle and soil particle-metal are calibrated.Besides,the adhesion test shows that the adhesion forces were ranked in the order of 5052<STi80<TA2<TC4 under the same surface roughness,which indicates the aluminum alloy 5052 has the best anti-adhesion performance.The relationship between surface adhesion force and microscopic contact parameters was studied by discrete element numerical simulation,and the result shows that the coefficient of static friction and the coefficient of rolling friction has little effect on adhesion force.While it is mainly affected by the coefficient of restitution and surface energy,the surface adhesion force tends to decrease with the increase of the coefficient of restitution and increase with the growth of surface energy.The obtained parameters of soil particle to soil particle and soil particle to metal affecting the adhesion can contribute to the design optimization for the grouser of mining machines to decrease surface adhesion and enhance its movability and mining efficiency.
基金supported by the National Science Foundation of China ( 11772133, 11372116)
文摘Integrins are heterodimeric cell surface receptors that bind to ligands on another cell,e.g.intercellular adhesion molecule 1(ICAM-1),or the extracellular matrix.Integrins play an important role in immune system,and they participate in inflammation,thrombosis,and proliferation,migration and apoptosis of tumor cells.They mediate adhesion and transduce signals across the membrane usually under the influence of forces.A recent study has shown that integrins bind and activate transforming growth factorβisoform(TGF-β)which is involved in tumor suppression and growth,and blocking the binding of TGF-βto integrin can inhibit tumor growth.RGD(arginine-glycine-aspartate)small peptide,which competitively inhibits ligand binding to integrins,has been approved as an injectable drug.However,when the RGD is used to block cancer-related extracellular signaling pathways,it will also cause activation of integrins for a period,and stimulate the transduction of intracellular signals constantly.Therefore,it is necessary to explore for new drugs that can selectively control conformational state of integrins without activating or blocking all of them.In this study,we selected two small peptides,KQAGDV and RTDLDSLRT,that combined with integrins and do not contain an RGD sequence.The non-RGD polypeptide RTDLDSLRT has been reported to have a binding site with integrins and the binding affinity is on nanomolar scale.For the motif of the fibrinogen y chain C-terminal KQAGDV,it can adhere to the head of the integrins.The micropipette aspiration technique and electron microscopy techniques were used to study the adhesion and activation of integrins by peptides,respectively.Micropipette aspiration technique was used to investigate the adhesion frequency of peptide and integrin on Jurkat cell.The pressure system was used to supply a controllable negative pression to the microtube,and two micropipettes were used to absorb red blood cells and Jurkat cells,respectively.The red blood cells were coated with small peptides and can serve as a force sensor after being sucked when two cells were connected.The binding kinetics of integrin and peptides interactions was determined by fitting the curves constructed using adhesion probability between two cells as a function of time.The curves were fitted using a small system probabilistic kinetic model to estimate a pair of kinetic parameters,including the zero force reverse rate kr0,and the cellular binding affinity Acmrm1Ka0.The adhesion frequency yielded P(t)=75%and 57%for RGD and KQAG DV peptides,respectively.We obtained Acmrm1Ka0=1.40 and kr0=0.32 s-1,for RGD,and Acmrm1Ka0=0.85 and kr0=0.54 s-1 for KQAGDV.The RGD peptide has a higher adhesion frequency and lower dissociation rate than the KQAGDV peptide.Electron microscopy techniques was used to observe the activation of integrins by peptides.Jurkat cell expressing integrins was bound to a magnetic bead and bottom plate which were coated with different integrin-binding peptides.Then,we manipulated the beads in a controlled direction by changing the magnetic field nearby,and the forces were applied to the cell.The target cells were fixed and then observed by scanning electron microscope or transmission electron microscope.Jurkat cells contain abundant flexible microvilli of which there are many parallel bundles of actin filaments inside.By electron microscopy analysis,the cell connected with magnetic bead coated with RGD were found to be protruded and the size of microvilli increased up to#-fold of the length of the KQAGDV sample.The microvilli exhibited a curved agglomerate structure under a force-free condition.Moreover,a higher proportion of cells were activated in the presence of RGD than KQAGDV.In conclusion,the binding affinity of KQAGDV to integrin is weaker than RGD,and KQAGDV can bind with integrins effectively with a lower activated proportion.Our results indicate the peptides may selectively bind to integrins without activating them.
基金supported by Grants-in-Aid from the National Natural Science Foundation of China No.10632010,30670517
文摘The size mismatch in an end-to-end vascular anastomosis between the host vessel and the graft may cause flow disturbance and predispose to thrombosis [1].Although a number of techniques have been employed to reduce the risk of anastomotic thrombosis due to the size mismatch。
基金supported by National Natural Science Foundation of China,No.30700151
文摘Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some pathologic conditions.However,the law of
文摘In response to current development of materials in nano-science.characterisation of thin coating adhesion ona nano-scale becomes one of the most important research areas,as new coatings get ever thinner and more technologically advanced.With a review of technology and mechanisms of evaluating the adhesion failure of coatings.three techniques,nano-im-pact,nano-scratch and nano-indentation techniques,for charactering the adhesion of thin coatings on a nano scale are described.Results of charactering the adhesion faliure of thin coatings using three different techniques indicate that the nano scratch and nano-indentation techniques are very useful tools particularly in charactering the performance of thin coatings under nano-abra sive wear conditions.However,results from these types of tests cannot be easily applied to predict the performance of coatings whose are subject to nano-erosive wear,cyclic nano-fatigue or multiple nano-impacts during service.Instead,results of the new dynamic testing technique。
