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Specific Temperatures (specific + temperature)
Selected AbstractsEffects of Inulin/Oligofructose on the Thermal Stability and Acid-Induced Gelation of Soy ProteinsJOURNAL OF FOOD SCIENCE, Issue 2 2008Y.-C. Tseng ABSTRACT:, Differential scanning calorimetry (DSC) and dynamic oscillatory shear testing were performed to study the influence of inulin (RaftilineŽ HP-gel and RaftilineŽ ST-gel) and oligofructose (RaftiloseŽ P95) on the thermal stability and gelation (using glucono-,-lactone [GDL] as a coagulant) of soy protein isolate (SPI) dispersions. Addition of 10% (w/v) inulin/oligofructose or sucrose increased (P < 0.05) the peak denaturation temperatures (Tm) of 7S and 11S soy proteins in SPI dispersion (5%[w/v], pH 7.0) by an average of 1.9 and 2.3 °C, respectively. GDL induced SPI thermal gelation, and the gel rheology was affected by both the pH decline and the specific temperature of heating. Addition of inulin/oligofructose (8%, w/v) improved the gelling properties of preheated SPI dispersion (8%, w/v) coagulated with GDL, showing 14.4 to 45.6% increase (P < 0.05) in gel rigidity (G, value) at the end of heating (81 °C). Microstructural examination revealed a denser protein cross-linking structure and reduced pore sizes in SPI gels containing inulin/oligofructose. In general, inulin was more capable of improving SPI gelation than oligofructose, suggesting that the degree of fructose polymerization in the fructans was of thermal and rheological importance. [source] A new temperature-sensitive contrast mechanism for MRI: Curie temperature transition-based imagingCONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007F. Settecase Abstract A temperature-sensitive MRI contrast mechanism is proposed based on the physical property, the Curie temperature (Tc), at which a ferromagnetic material transitions to paramagnetic state and vice versa. To evaluate the feasibility of this new contrast mechanism, experiments were performed with solid gadolinium metal, which has a Tc of 20°C. In phantom and ex vivo experiments, the magnetic susceptibility artifact area decreased with increasing temperature transitioning across Tc (p,<,0.05). Similar results would be expected for a variety of ferromagnetic substances with substance-specific Tc values. Temperature-sensitive MRI contrast agents harnessing this mechanism may be used to (1) indicate regional attainment of specific temperatures in thermotherapy, (2) render an accumulated contrast agent more or less visible by the external application of appropriate heating or cooling, or (3) quantify tissue temperature based on MR image characteristics and magnetic susceptibility artifact caused by a ferromagnetic,paramagnetic transitioning substance. Copyright Š 2007 John Wiley & Sons, Ltd. [source] Consequences Arising From Elevated Surface Temperatures on Human BloodARTIFICIAL ORGANS, Issue 9 2010Kathrin F. Hamilton Abstract Heat in blood pumps is generated by losses of the electrical motor and bearings. In the presented study the influence of tempered surfaces on bulk blood and adhesions on these surfaces was examined. Titanium alloy housing dummies were immersed in 25 mL heparinized human blood. The dummies were constantly tempered at specific temperatures (37,45°C) over 15 min. Blood samples were withdrawn for blood parameter analysis and the determination of the plasmatic coagulation cascade. The quantities of adhesion on surfaces were determined by drained weight. Blood parameters do not alter significantly up to surface temperatures of 45°C. In comparison to the control specimen, a drop in the platelet count can be observed, but is not significantly temperature dependent. The mean mass of adhesions at 41°C increased up to 66% compared to 37°C. Thus, heat generated in electrical motors and contact bearings may influence the amount of adhesions on surfaces. [source] Impact of Hyperthermal Rotary Blood Pump Surfaces on Blood Clotting Behavior: An ApproachARTIFICIAL ORGANS, Issue 9 2009Kathrin F. Hamilton Abstract The influence of heat dissipating systems, such as rotary blood pumps, was investigated. Titanium cylinders as rotary blood pump housing dummies were immersed in porcine blood and constantly tempered at specific temperatures (37,60°C) over a defined period of time. The porcine blood was anticoagulated either by low heparin dosage or citrate. At frequent intervals, samples were taken for blood analysis and the determination of the plasmatic coagulation cascade. Blood parameters do not alter at surface temperatures below 50°C. Hyperthermia-induced hemolysis could be confirmed. The plasmatic coagulation cascade is terminated at surface temperatures exceeding 55°C. The adhesion of blood constituents on surfaces is temperature and time dependent, and structural changes of adhesions and blood itself were detected. [source] An investigation into direct dye aggregationCOLORATION TECHNOLOGY, Issue 1 2002M. Ferus-Comelo The aggregation characteristics of the direct dye CI Yellow 162 have been investigated by measuring the optical transmittance at specific temperatures, in the presence and absence of electrolyte and surfactant, using a Hellma quartz immersion probe attached via fibre optical cables to a single-beam Zeiss Specord S 100 spectrophotometer. The experiments indicate that the dye in solution, without electrolyte, was monomolecular at temperatures of 70 °C and higher. The dye solution with electrolyte remained aggregated at temperatures up to 90 °C, a finding contrary to the still widespread assumption that the dyes are monomolecular at elevated temperatures. In the presence of a surfactant the dye appeared to be forming dye,surfactant micelles that were fairly stable even at higher temperatures. [source] | |||||||||||||