The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Amy E Herr - One of the best experts on this subject based on the ideXlab platform.
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microfluidic western blotting of low Molecular Mass proteins
Analytical Chemistry, 2014Co-Authors: Rachel E. Gerver, Amy E HerrAbstract:We describe a microfluidic Western blot assay (μWestern) using a Tris tricine discontinuous buffer system suitable for analyses of a wide Molecular Mass range (6.5–116 kDa). The Tris tricine μWestern is completed in an enclosed, straight glass microfluidic channel housing a photopatterned polyacrylamide gel that incorporates a photoactive benzophenone methacrylamide monomer. Upon brief ultraviolet (UV) light exposure, the hydrogel toggles from Molecular sieving for size-based separation to a covalent immobilization scaffold for in situ antibody probing. Electrophoresis controls all assay stages, affording purely electronic operation with no pumps or valves needed for fluid control. Electrophoretic introduction of antibody into and along the Molecular sieving gel requires that the probe must traverse through (i) a discontinuous gel interface central to the transient isotachophoresis used to achieve high-performance separations and (ii) the full axial length of the separation gel. In-channel antibody probing of small Molecular Mass species is especially challenging, since the gel must effectively sieve small proteins while permitting effective probing with large-Molecular-Mass antibodies. To create a well-controlled gel interface, we introduce a fabrication method that relies on a hydrostatic pressure mismatch between the buffer and polymer precursor solution to eliminate the interfacial pore-size control issues that arise when a polymerizing polymer abuts a nonpolymerizing polymer solution. Combined with a new swept antibody probe plug delivery scheme, the Tris tricine μWestern blot enables 40% higher separation resolution as compared to a Tris glycine system, destacking of proteins down to 6.5 kDa, and a 100-fold better signal-to-noise ratio (SNR) for small pore gels, expanding the range of applicable biological targets.
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Microfluidic western blotting of low-Molecular-Mass proteins
Analytical Chemistry, 2014Co-Authors: Rachel E. Gerver, Amy E HerrAbstract:© 2014 American Chemical Society. We describe a microfluidic Western blot assay (μWestern) using a Tris tricine discontinuous buffer system suitable for analyses of a wide Molecular Mass range (6.5-116 kDa). The Tris tricine μWestern is completed in an enclosed, straight glass microfluidic channel housing a photopatterned polyacrylamide gel that incorporates a photoactive benzophenone methacrylamide monomer. Upon brief ultraviolet (UV) light exposure, the hydrogel toggles from Molecular sieving for size-based separation to a covalent immobilization scaffold for in situ antibody probing. Electrophoresis controls all assay stages, affording purely electronic operation with no pumps or valves needed for fluid control. Electrophoretic introduction of antibody into and along the Molecular sieving gel requires that the probe must traverse through (i) a discontinuous gel interface central to the transient isotachophoresis used to achieve high-performance separations and (ii) the full axial length of the separation gel. In-channel antibody probing of small Molecular Mass species is especially challenging, since the gel must effectively sieve small proteins while permitting effective probing with large-Molecular-Mass antibodies. To create a well-controlled gel interface, we introduce a fabrication method that relies on a hydrostatic pressure mismatch between the buffer and polymer precursor solution to eliminate the interfacial pore-size control issues that arise when a polymerizing polymer abuts a nonpolymerizing polymer solution. Combined with a new swept antibody probe plug delivery scheme, the Tris tricine μWestern blot enables 40% higher separation resolution as compared to a Tris glycine system, destacking of proteins down to 6.5 kDa, and a 100-fold better signal-to-noise ratio (SNR) for small pore gels, expanding the range of applicable biological targets.
Rachel E. Gerver - One of the best experts on this subject based on the ideXlab platform.
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microfluidic western blotting of low Molecular Mass proteins
Analytical Chemistry, 2014Co-Authors: Rachel E. Gerver, Amy E HerrAbstract:We describe a microfluidic Western blot assay (μWestern) using a Tris tricine discontinuous buffer system suitable for analyses of a wide Molecular Mass range (6.5–116 kDa). The Tris tricine μWestern is completed in an enclosed, straight glass microfluidic channel housing a photopatterned polyacrylamide gel that incorporates a photoactive benzophenone methacrylamide monomer. Upon brief ultraviolet (UV) light exposure, the hydrogel toggles from Molecular sieving for size-based separation to a covalent immobilization scaffold for in situ antibody probing. Electrophoresis controls all assay stages, affording purely electronic operation with no pumps or valves needed for fluid control. Electrophoretic introduction of antibody into and along the Molecular sieving gel requires that the probe must traverse through (i) a discontinuous gel interface central to the transient isotachophoresis used to achieve high-performance separations and (ii) the full axial length of the separation gel. In-channel antibody probing of small Molecular Mass species is especially challenging, since the gel must effectively sieve small proteins while permitting effective probing with large-Molecular-Mass antibodies. To create a well-controlled gel interface, we introduce a fabrication method that relies on a hydrostatic pressure mismatch between the buffer and polymer precursor solution to eliminate the interfacial pore-size control issues that arise when a polymerizing polymer abuts a nonpolymerizing polymer solution. Combined with a new swept antibody probe plug delivery scheme, the Tris tricine μWestern blot enables 40% higher separation resolution as compared to a Tris glycine system, destacking of proteins down to 6.5 kDa, and a 100-fold better signal-to-noise ratio (SNR) for small pore gels, expanding the range of applicable biological targets.
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Microfluidic western blotting of low-Molecular-Mass proteins
Analytical Chemistry, 2014Co-Authors: Rachel E. Gerver, Amy E HerrAbstract:© 2014 American Chemical Society. We describe a microfluidic Western blot assay (μWestern) using a Tris tricine discontinuous buffer system suitable for analyses of a wide Molecular Mass range (6.5-116 kDa). The Tris tricine μWestern is completed in an enclosed, straight glass microfluidic channel housing a photopatterned polyacrylamide gel that incorporates a photoactive benzophenone methacrylamide monomer. Upon brief ultraviolet (UV) light exposure, the hydrogel toggles from Molecular sieving for size-based separation to a covalent immobilization scaffold for in situ antibody probing. Electrophoresis controls all assay stages, affording purely electronic operation with no pumps or valves needed for fluid control. Electrophoretic introduction of antibody into and along the Molecular sieving gel requires that the probe must traverse through (i) a discontinuous gel interface central to the transient isotachophoresis used to achieve high-performance separations and (ii) the full axial length of the separation gel. In-channel antibody probing of small Molecular Mass species is especially challenging, since the gel must effectively sieve small proteins while permitting effective probing with large-Molecular-Mass antibodies. To create a well-controlled gel interface, we introduce a fabrication method that relies on a hydrostatic pressure mismatch between the buffer and polymer precursor solution to eliminate the interfacial pore-size control issues that arise when a polymerizing polymer abuts a nonpolymerizing polymer solution. Combined with a new swept antibody probe plug delivery scheme, the Tris tricine μWestern blot enables 40% higher separation resolution as compared to a Tris glycine system, destacking of proteins down to 6.5 kDa, and a 100-fold better signal-to-noise ratio (SNR) for small pore gels, expanding the range of applicable biological targets.
Johannes F.g. Vliegenthart - One of the best experts on this subject based on the ideXlab platform.
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The influence of starch Molecular Mass on the properties of extruded thermoplastic starch
Polymer, 1996Co-Authors: J.j.g. Van Soest, Kiley Benes, Johannes F.g. VliegenthartAbstract:The mechanical properties of a low and a high Molecular Mass thermoplastic starch (TPS) were monitored at water contents in the range of 5-30% (w/w). The granular starches were plasticized by extrusion processing with glycerol and water. The low Molecular Mass starch was prepared by partial acid hydrolysis of potato starch. The extruded TPS materials were stored at 60% relative humidity for 12 months to level out differences in starch structure due to retrogradation. The water content was then varied by an additional storage period at various humidities. The average Molecular Masses of the TPS materials, composed of native starch or of hydrolysed starch, were 37 000 and 1900 kg mol-1, respectively. The apparent amylose contents of the high and low Molecular Mass materials were 25% and 11%, respectively. Differences were observed in thermal properties and crystallinity between the two types of materials, as a function of water content but not as a function of Molecular Mass. The stress-strain properties of the materials were dependent on the water content. The materials showed a viscoelastic behaviour characteristic of a semicrystalline polymer. Materials containing less than 9% water were glassy with an elastic modulus between 400 and 1000 MPa. For the materials a transition from brittle to ductile behaviour occurred at a water content in the range of 9-10%, which is in accordance with the observed glass transition temperature at this water content. The rubbery materials, with a water content of 9-15%, were tough and an optimum in ultimate elongation was observed. Above a water content of 15% the materials became weak and soft and the strain at break decreased. No significant differences in brittle-to-ductile transition as a function of water content were observed between the low and high Molecular Mass TPS materials. In the rubbery state with 14% water, the elongations at break of the high and low Molecular Mass materials were 100-125% and 30-50%, respectively. The tearing energy of the materials showed a maximum at a water content of 9-10%. The energies at this maximum of the high and low Molecular Mass materials were 0.15 and 0.1J mm-2, respectively. The lower strain and tearing energy of the low Molecular Mass materials in the rubbery state were attributed to the reduced amylose chain length as well as the Molecular Mass and the degree of branching of the amylopectin molecules. This resulted in a material with a less effective entangled starch matrix. The entanglements were described as a complex network of the linear amylose chains and the outer chains of the amylopectin molecules in which hydrogen bonding plays an important role. Copyright
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The influence of starch Molecular Mass on the properties of extruded thermoplastic starch
Polymer, 1996Co-Authors: J. J.g. Van Soest, D. De Wit, Kiley Benes, Johannes F.g. VliegenthartAbstract:The mechanical properties of a low and a high Molecular Mass thermoplastic starch (TPS) were monitored at water contents in the range of 5-30% (w/w). The granular starches were plasticized by extrusion processing with glycerol and water. The low Molecular Mass starch was prepared by partial acid hydrolysis of potato starch. The extruded TPS materials were stored at 60% relative humidity for 12 months to level out differences in starch structure due to retrogradation. The water content was then varied by an additional storage period at various humidities. The average Molecular Masses of the TPS materials, composed of native starch or of hydrolysed starch, were 37 000 and 1900 kg mol-1, respectively. The apparent amylose contents of the high and low Molecular Mass materials were 25% and 11%, respectively. Differences were observed in thermal properties and crystallinity between the two types of materials, as a function of water content but not as a function of Molecular Mass. The stress-strain properties of the materials were dependent on the water content. The materials showed a viscoelastic behaviour characteristic of a semicrystalline polymer. Materials containing less than 9% water were glassy with an elastic modulus between 400 and 1000 MPa. For the materials a transition from brittle to ductile behaviour occurred at a water content in the range of 9-10%, which is in accordance with the observed glass transition temperature at this water content. The rubbery materials, with a water content of 9-15%, were tough and an optimum in ultimate elongation was observed. Above a water content of 15% the materials became weak and soft and the strain at break decreased. No significant differences in brittle-to-ductile transition as a function of water content were observed between the low and high Molecular Mass TPS materials. In the rubbery state with 14% water, the elongations at break of the high and low Molecular Mass materials were 100-125% and 30-50%, respectively. The tearing energy of the materials showed a maximum at a water content of 9-10%. The energies at this maximum of the high and low Molecular Mass materials were 0.15 and 0.1J mm-2, respectively. The lower strain and tearing energy of the low Molecular Mass materials in the rubbery state were attributed to the reduced amylose chain length as well as the Molecular Mass and the degree of branching of the amylopectin molecules. This resulted in a material with a less effective entangled starch matrix. The entanglements were described as a complex network of the linear amylose chains and the outer chains of the amylopectin molecules in which hydrogen bonding plays an important role. Copyright © 1996 Elsevier Science Ltd.
Eugene Rosenberg - One of the best experts on this subject based on the ideXlab platform.
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high and low Molecular Mass microbial surfactants
Applied Microbiology and Biotechnology, 1999Co-Authors: Eugene RosenbergAbstract:Microorganisms synthesize a wide variety of high- and low-Molecular-Mass bioemulsifiers. The low-Molecular-Mass bioemulsifiers are generally glycolipids, such as trehalose lipids, sophorolipids and rhamnolipids, or lipopeptides, such as surfactin, gramicidin S and polymyxin. The high-Molecular-Mass bioemulsifiers are amphipathic polysaccharides, proteins, lipopolysaccharides, lipoproteins or complex mixtures of these biopolymers. The low-Molecular-Mass bioemulsifiers lower surface and interfacial tensions, whereas the higher-Molecular-Mass bioemulsifiers are more effective at stabilizing oil-in-water emulsions. Three natural roles for bioemulsifiers have been proposed: (i) increasing the surface area of hydrophobic water-insoluble growth substrates; (ii) increasing the bioavailability of hydrophobic substrates by increasing their apparent solubility or desorbing them from surfaces; (iii) regulating the attachment and detachment of microorganisms to and from surfaces. Bioemulsifiers have several important advantages over chemical surfactants, which should allow them to become prominent in industrial and environmental applications. The potential commercial applications of bioemulsifiers include bioremediation of oil-polluted soil and water, enhanced oil recovery, replacement of chlorinated solvents used in cleaning-up oil-contaminated pipes, vessels and machinery, use in the detergent industry, formulations of herbicides and pesticides and formation of stable oil-in-water emulsions for the food and cosmetic industries.
J. J.g. Van Soest - One of the best experts on this subject based on the ideXlab platform.
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The influence of starch Molecular Mass on the properties of extruded thermoplastic starch
Polymer, 1996Co-Authors: J. J.g. Van Soest, D. De Wit, Kiley Benes, Johannes F.g. VliegenthartAbstract:The mechanical properties of a low and a high Molecular Mass thermoplastic starch (TPS) were monitored at water contents in the range of 5-30% (w/w). The granular starches were plasticized by extrusion processing with glycerol and water. The low Molecular Mass starch was prepared by partial acid hydrolysis of potato starch. The extruded TPS materials were stored at 60% relative humidity for 12 months to level out differences in starch structure due to retrogradation. The water content was then varied by an additional storage period at various humidities. The average Molecular Masses of the TPS materials, composed of native starch or of hydrolysed starch, were 37 000 and 1900 kg mol-1, respectively. The apparent amylose contents of the high and low Molecular Mass materials were 25% and 11%, respectively. Differences were observed in thermal properties and crystallinity between the two types of materials, as a function of water content but not as a function of Molecular Mass. The stress-strain properties of the materials were dependent on the water content. The materials showed a viscoelastic behaviour characteristic of a semicrystalline polymer. Materials containing less than 9% water were glassy with an elastic modulus between 400 and 1000 MPa. For the materials a transition from brittle to ductile behaviour occurred at a water content in the range of 9-10%, which is in accordance with the observed glass transition temperature at this water content. The rubbery materials, with a water content of 9-15%, were tough and an optimum in ultimate elongation was observed. Above a water content of 15% the materials became weak and soft and the strain at break decreased. No significant differences in brittle-to-ductile transition as a function of water content were observed between the low and high Molecular Mass TPS materials. In the rubbery state with 14% water, the elongations at break of the high and low Molecular Mass materials were 100-125% and 30-50%, respectively. The tearing energy of the materials showed a maximum at a water content of 9-10%. The energies at this maximum of the high and low Molecular Mass materials were 0.15 and 0.1J mm-2, respectively. The lower strain and tearing energy of the low Molecular Mass materials in the rubbery state were attributed to the reduced amylose chain length as well as the Molecular Mass and the degree of branching of the amylopectin molecules. This resulted in a material with a less effective entangled starch matrix. The entanglements were described as a complex network of the linear amylose chains and the outer chains of the amylopectin molecules in which hydrogen bonding plays an important role. Copyright © 1996 Elsevier Science Ltd.
