The Experts below are selected from a list of 3141 Experts worldwide ranked by ideXlab platform
Elliot L Chaikof - One of the best experts on this subject based on the ideXlab platform.
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the effect of a recombinant elastin mimetic coating of an eptfe prosthesis on acute thrombogenicity in a baboon arteriovenous shunt
Biomaterials, 2007Co-Authors: Sumanas W Jordan, Carolyn A Haller, Rory E Sallach, Robert P Apkarian, Stephen R Hanson, Elliot L ChaikofAbstract:Abstract A recombinant elastin-mimetic triblock protein polymer with an inverse transition temperature (∼20 °C) was used to impregnate small-diameter (4 mm i.d.) expanded polytetrafluoroethylene (ePTFE) vascular grafts. Scanning electron microscopy confirmed that initial elastin impregnation of the graft followed by further multilayer coating with elastin films filled in the fibril and node structure of the luminal surface of the ePTFE graft and was macroscopically smooth. Elastin protein polymer impregnation reduced the Advancing Contact Angle of the luminal surface to 43°, which was comparable to the Advancing Contact Angle of 47° for a cast elastin film. Attenuated total reflection infrared spectroscopy and Coomassie blue staining revealed little discernable change in the protein surface film after 24 h of shear at 500 s −1 and 37 °C. Excellent short-term blood-Contacting properties as determined by minimal fibrin and platelet deposition were demonstrated using a baboon extracorporeal femoral arteriovenous shunt model. The results of this study demonstrate the applicability of an elastin-mimetic triblock protein polymer as a non-thrombogenic coating or as a component of a tissue-engineered composite.
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the effect of a recombinant elastin mimetic coating of an eptfe prosthesis on acute thrombogenicity in a baboon arteriovenous shunt
Biomaterials, 2007Co-Authors: Sumanas W Jordan, Carolyn A Haller, Rory E Sallach, Robert P Apkarian, Stephen R Hanson, Elliot L ChaikofAbstract:A recombinant elastin-mimetic triblock protein polymer with an inverse transition temperature (approximately 20 degrees C) was used to impregnate small-diameter (4 mm i.d.) expanded polytetrafluoroethylene (ePTFE) vascular grafts. Scanning electron microscopy confirmed that initial elastin impregnation of the graft followed by further multilayer coating with elastin films filled in the fibril and node structure of the luminal surface of the ePTFE graft and was macroscopically smooth. Elastin protein polymer impregnation reduced the Advancing Contact Angle of the luminal surface to 43 degrees, which was comparable to the Advancing Contact Angle of 47 degrees for a cast elastin film. Attenuated total reflection infrared spectroscopy and Coomassie blue staining revealed little discernable change in the protein surface film after 24 h of shear at 500 s(-1) and 37 degrees C. Excellent short-term blood-Contacting properties as determined by minimal fibrin and platelet deposition were demonstrated using a baboon extracorporeal femoral arteriovenous shunt model. The results of this study demonstrate the applicability of an elastin-mimetic triblock protein polymer as a non-thrombogenic coating or as a component of a tissue-engineered composite.
Xinxin Zhang - One of the best experts on this subject based on the ideXlab platform.
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determining the surface tension of two dimensional nanosheets by a low rate Advancing Contact Angle measurement
Langmuir, 2019Co-Authors: Xinru Zhang, Zeyi Jiang, Hao Yuan, Yang Wang, Xinxin ZhangAbstract:Because of their atomic thinness, two-dimensional (2D) nanosheets need be bound to a substrate or be dispersed in material in various applications. The surface tension (ST) of a 2D nanosheet is critical for analyzing the physicochemical interactions between 2D nanosheets and other materials. To date, the determination of the ST of 2D nanosheets has relied mainly on the Contact Angle (CA) method. However, because of the difficulty in measuring the thermodynamically significant Young?s CA, which is the only meaningful CA that can be used to determine the ST, significant differences exist in reported STs of 2D nanosheets. In this study, we obtained such unique Young?s CAs on graphene, boron nitride, molybdenum disulfide, and tungsten disulfide nanosheets by a low-rate Advancing Contact Angle measurement using a rigorously designed experimental setup. By interpreting the CA with Neumann?s equation of state, we determined the STs of these four nanosheets to be 29.7 ? 0.6, 30.9 ? 0.7, 27.8 ? 0.7, and 29.1 ? 0.8...
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determining the surface tension of two dimensional nanosheets by a low rate Advancing Contact Angle measurement
Langmuir, 2019Co-Authors: Xinru Zhang, Zeyi Jiang, Hao Yuan, Yang Wang, Xinzhi Cai, Kairu Jin, Yan Jia, Limei Cao, Xinxin ZhangAbstract:Because of their atomic thinness, two-dimensional (2D) nanosheets need be bound to a substrate or be dispersed in material in various applications. The surface tension (ST) of a 2D nanosheet is cri...
Victor Starov - One of the best experts on this subject based on the ideXlab platform.
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hysteresis of Contact Angle of sessile droplets on smooth homogeneous solid substrates via disjoining conjoining pressure
Langmuir, 2015Co-Authors: I V Kuchin, Victor StarovAbstract:A theory of Contact Angle hysteresis of liquid droplets on smooth, homogeneous solid substrates is developed in terms of the shape of the disjoining/conjoining pressure isotherm and quasi-equilibrium phenomena. It is shown that all Contact Angles, θ, in the range θr < θ < θa, which are different from the unique equilibrium Contact Angle θ ≠ θe, correspond to the state of slow "microscopic" Advancing or receding motion of the liquid if θe < θ < θa or θr < θ < θe, respectively. This "microscopic" motion almost abruptly becomes fast "macroscopic" Advancing or receding motion after the Contact Angle reaches the critical values θa or θr, correspondingly. The values of the static receding, θr, and static Advancing, θa, Contact Angles in cylindrical capillaries were calculated earlier, based on the shape of disjoining/conjoining pressure isotherm. It is shown now that (i) both Advancing and receding Contact Angles of a droplet on a on smooth, homogeneous solid substrate can be calculated based on shape of disjoining/conjoining pressure isotherm, and (ii) both Advancing and receding Contact Angles depend on the drop volume and are not unique characteristics of the liquid-solid system. The latter is different from Advancing/receding Contact Angles in thin capillaries. It is shown also that the receding Contact Angle is much closer to the equilibrium Contact Angle than the Advancing Contact Angle. The latter conclusion is unexpected and is in a contradiction with the commonly accepted view that the Advancing Contact Angle can be taken as the first approximation for the equilibrium Contact Angle. The dependency of hysteresis Contact Angles on the drop volume has a direct experimental confirmation.
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static Contact Angle hysteresis on smooth homogeneous solid substrates
Colloid and Polymer Science, 2013Co-Authors: Victor StarovAbstract:A theory of Contact Angle hysteresis on smooth, homogeneous solid substrates is developed in terms of shape of disjoining/conjoining pressure isotherm and quasi-equilibrium phenomena. It is shown that all Contact Angles, θ, in the range θr < θ < θa, which are different from the unique equilibrium Contact Angle θ ≠ θe, correspond to the state of slow “microscopic” Advancing or receding motion of the liquid if θe < θ < θa or θr < θ < θe, respectively. This “microscopic” motion almost abruptly becomes fast “macroscopic” Advancing or receding motion after the Contact Angle reaches the critical values θ = θa or θr = θ, correspondingly. The values of the static receding, θr, and static Advancing, θa, Contact Angles in cylindrical capillaries were calculated earlier, based on the shape of disjoining pressure isotherm. It is shown that an Advancing Contact Angle of a droplet on a solid substrate depends on the drop volume and is not a unique characteristic of the liquid–solid system. The suggested mechanism of Contact Angle hysteresis has direct experimental confirmation.
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evaporation of sessile water droplets universal behaviour in presence of Contact Angle hysteresis
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011Co-Authors: Sergey Semenov, Victor Starov, Ramon G Rubio, Hezekiah Agogo, Manuel G VelardeAbstract:A theory is presented, which describes the diffusion limited evaporation of sessile water droplets in presence of Contact Angle hysteresis. Theory describes two stages of evaporation process: (I) evaporation with a constant radius of the droplet base; and (II) evaporation with a constant Contact Angle. During stage (I) the Contact Angles decreases from static Advancing Contact Angle to static receding Contact Angle. During stage (II) the Contact Angle remains equal to the static receding Contact Angle. Universal dependences are deduced for both evaporation stages. Obtained universal curves are validated against available in the literature experimental data.
Sumanas W Jordan - One of the best experts on this subject based on the ideXlab platform.
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the effect of a recombinant elastin mimetic coating of an eptfe prosthesis on acute thrombogenicity in a baboon arteriovenous shunt
Biomaterials, 2007Co-Authors: Sumanas W Jordan, Carolyn A Haller, Rory E Sallach, Robert P Apkarian, Stephen R Hanson, Elliot L ChaikofAbstract:Abstract A recombinant elastin-mimetic triblock protein polymer with an inverse transition temperature (∼20 °C) was used to impregnate small-diameter (4 mm i.d.) expanded polytetrafluoroethylene (ePTFE) vascular grafts. Scanning electron microscopy confirmed that initial elastin impregnation of the graft followed by further multilayer coating with elastin films filled in the fibril and node structure of the luminal surface of the ePTFE graft and was macroscopically smooth. Elastin protein polymer impregnation reduced the Advancing Contact Angle of the luminal surface to 43°, which was comparable to the Advancing Contact Angle of 47° for a cast elastin film. Attenuated total reflection infrared spectroscopy and Coomassie blue staining revealed little discernable change in the protein surface film after 24 h of shear at 500 s −1 and 37 °C. Excellent short-term blood-Contacting properties as determined by minimal fibrin and platelet deposition were demonstrated using a baboon extracorporeal femoral arteriovenous shunt model. The results of this study demonstrate the applicability of an elastin-mimetic triblock protein polymer as a non-thrombogenic coating or as a component of a tissue-engineered composite.
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the effect of a recombinant elastin mimetic coating of an eptfe prosthesis on acute thrombogenicity in a baboon arteriovenous shunt
Biomaterials, 2007Co-Authors: Sumanas W Jordan, Carolyn A Haller, Rory E Sallach, Robert P Apkarian, Stephen R Hanson, Elliot L ChaikofAbstract:A recombinant elastin-mimetic triblock protein polymer with an inverse transition temperature (approximately 20 degrees C) was used to impregnate small-diameter (4 mm i.d.) expanded polytetrafluoroethylene (ePTFE) vascular grafts. Scanning electron microscopy confirmed that initial elastin impregnation of the graft followed by further multilayer coating with elastin films filled in the fibril and node structure of the luminal surface of the ePTFE graft and was macroscopically smooth. Elastin protein polymer impregnation reduced the Advancing Contact Angle of the luminal surface to 43 degrees, which was comparable to the Advancing Contact Angle of 47 degrees for a cast elastin film. Attenuated total reflection infrared spectroscopy and Coomassie blue staining revealed little discernable change in the protein surface film after 24 h of shear at 500 s(-1) and 37 degrees C. Excellent short-term blood-Contacting properties as determined by minimal fibrin and platelet deposition were demonstrated using a baboon extracorporeal femoral arteriovenous shunt model. The results of this study demonstrate the applicability of an elastin-mimetic triblock protein polymer as a non-thrombogenic coating or as a component of a tissue-engineered composite.
Nobuo Maeda - One of the best experts on this subject based on the ideXlab platform.
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removal of induced nanobubbles from water graphite interfaces by partial degassing
Langmuir, 2006Co-Authors: Xuehua Zhang, Gang Li, Nobuo Maeda, Jun HuAbstract:Nanobubbles at an interface between a hydrophobic solid and water have a wide range of implications, but the evidence for their existence is still being debated. Here we artificially induced nanobubbles on freshly cleaved HOPG substrates in water using the protocol developed previously and subjected the system to moderate levels of degassing (∼0.1 atm for 0.5 to 3 h). The AFM images after the partial degassing revealed that some nanobubbles had coalesced and detached from the substrate because of buoyancy, whereas others apparently remained unaffected. The size and spatial distributions of the nanobubbles after the partial degassing suggest that there is a critical size for a nanobubble above which it may grow. The Contact Angle of water next to nanobubbles (∼160°) is much larger than the Advancing Contact Angle of a macroscopic water droplet on the same substrate (∼80°) both before and after the partial degassing and concomitant growth and shrinkage of the nanobubbles. The Contact Angle of a nanobubble a...
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removal of induced nanobubbles from water graphite interfaces by partial degassing
Langmuir, 2006Co-Authors: Xuehua Zhang, Nobuo MaedaAbstract:Nanobubbles at an interface between a hydrophobic solid and water have a wide range of implications, but the evidence for their existence is still being debated. Here we artificially induced nanobubbles on freshly cleaved HOPG substrates in water using the protocol developed previously and subjected the system to moderate levels of degassing (approximately 0.1 atm for 0.5 to 3 h). The AFM images after the partial degassing revealed that some nanobubbles had coalesced and detached from the substrate because of buoyancy, whereas others apparently remained unaffected. The size and spatial distributions of the nanobubbles after the partial degassing suggest that there is a critical size for a nanobubble above which it may grow. The Contact Angle of water next to nanobubbles (approximately 160 degrees) is much larger than the Advancing Contact Angle of a macroscopic water droplet on the same substrate (approximately 80 degrees) both before and after the partial degassing and concomitant growth and shrinkage of the nanobubbles. The Contact Angle of a nanobubble also remained unchanged as the nanobubble was moved along the substrate by the AFM tip. The apparent lack of Contact Angle hysteresis in the nanobubble systems may suggest that the very large Contact Angle may correspond to a local minimum of the free-energy landscape.