Notes: We describe a phenomenological model for the thermal fluctuations of the line of contact between two fluid phases and one solid phase. The line of contact between the three phases is constrained to lie along the solid surface, which is assumed to be smooth, flat, and horizontal with respect to gravity. In order to model the fluctuations of the contact line we must account not only for the fluctuations of the contact line itself, but also the corresponding fluctuations of the fluid–fluid interface. We develop a model for the energy of a superposition of sinusoidal fluctuations of all possible wavelengths. Our model for the fluctuation energy includes the effects of line tension, surface tension, and gravity. This fluctuation energy is then used in a modified capillary wave model based on the usual capillary wave model for a two-phase fluid interface to calculate the mean square magnitude of thermal fluctuations. We find that if the line tension is zero the rms fluctuation amplitude of the contact line is roughly proportional to the corresponding amplitude for a two-phase fluid interface, where the factor of proportionality is the reciprocal of the contact angle. Positive line tension significantly reduces the rms fluctuation amplitude near a second order wetting transition. If the line tension is negative, the fluctuation energy becomes negative for short wavelength fluctuations and small θ, and our model breaks down. We discuss the implications of our results.

Notes: We describe a phenomenological model for the thermal fluctuations of a three-phase contact line in the case of three fluid phases. The model is an extension of an earlier model for the case of two fluids and one solid. In the previous model only one interface was allowed to fluctuate, and the contact line was constrained to move along the solid surface. In the present case all three two-phase interfaces can fluctuate, and the contact line can move in any direction. Our model includes the effects of line tension, the three surface tensions, and gravity. We investigate the behavior of the fluctuations in the limit of a wetting transition. Since the line tension appears to diverge in the limit of a first order transition, and vanishes in the limit of a second order transition, we consider each of these cases separately. We obtain the mean square fluctuation magnitude analytically if the line tension is identically zero. If the line tension is positive we obtain an integral expression for the mean square fluctuation magnitude, and derive modified exponents for the fluctuation magnitude as a function of contact angle near both a first and second order wetting transition. Our model breaks down if the line tension is negative, just as in the earlier model.

Notes: Abstract  Objectives: Resternotomy is a common part of cardiac surgical practice. Associated with resternotomy are the risks of cardiac injury and catastrophic hemorrhage and the subsequent elevated morbidity and mortality in the operating room or during the postoperative period. The technique of direct vision resternotomy is safe and has fewer, if any, serious cardiac injuries. The technique, the reduced need for groin cannulation and the overall low operative mortality and morbidity are the focus of this restrospective analysis. Methods: The records of 495 patients undergoing 546 resternotomies over a 21-year period to January 2000 were reviewed. All consecutive reoperations by the one surgeon comprised patients over the age of 20 at first resternotomy: M:F 343:203, mean age 57 years (range 20 to 85, median age 60). The mean NYHA grade was 2.3 [with 67 patients (I), 273 (II), 159 (III), 43 (IV), and 4 (V classification)] with elective reoperation in 94.6%. Cardiac injury was graded into five groups and the incidence and reasons for groin cannulation estimated. The morbidity and mortality as a result of the reoperation and resternotomy were assessed. Results: The hospital/30 day mortality was 2.9% (95% CI: 1.6%-4.4%) (16 deaths) over the 21 years. First (481), second (53), and third (12) resternotomies produced 307 uncomplicated technical reopenings, 203 slower but uncomplicated procedures, 9 minor superficial cardiac lacerations, and no moderate or severe cardiac injuries. Direct vision resternotomy is crystalized into the principle that only adhesions that are visualized from below are divided and only sternal bone that is freed of adhesions is sewn. Groin exposure was never performed prophylactically for resternotomy. Fourteen patients (2.6%) had such cannulation for aortic dissection/aneurysm (9 patients), excessive sternal adherence of cardiac structures (3 patients), presurgery cardiac arrest (1 patient), and high aortic cannulation desired and not possible (1 patient). The average postop blood loss was 594 mL (95% CI:558–631) in the first 12 hours. The need to return to the operating room for control of excessive bleeding was 2% (11 patients). Blood transfusion was given in 65% of the resternotomy procedures over the 21 years (mean 854 mL: 95% Cl 765–945 mL) and 41% over the last 5 years. Conclusions: The technique of direct vision resternotomy has been associated with zero moderate or major cardiac injury/catastrophic-hemorrhage at reoperation. Few patients have required groin cannulation. In the postoperative period, there was acceptable blood loss, transfusion rates, reduced morbidity, and moderate low mortality for this potentially high risk group.

Notes: Abstract  Objectives and Methods: Reoperations are an integral part of a cardiac surgeon's practice. We share our experience of 546 reoperations over the last 21 years to January 2000, with the focus directed towards the timing of reoperation, reducing the mortality and morbidity of reoperation and rereplacement aortic valve surgery, and understanding the important risk factors. In addition, the precise technical steps that facilitate careful successful explantation of various devices (allograft, stented and stentless xenografts, and mechanical valves) are detailed. Results: Optimal planned reoperation before deterioration to New York Heart Association Class III/IV levels and before unfavorable cardiac and comorbidity general system failure occurs has produced low mortality and morbidity as compared with first operation results. However, unfavorable delays and late rereferral result in mortality rates of up to 22% for emergency redo AVR for degenerated bioprostheses. Conclusion: Cardiac surgical units have the opportunity to establish a closer patient-surgeon relationship, which favors, when necessary, the optimal timing of reoperation. Knowledge of the more important risk factors and adherence to specific technical steps at explantation of various devices enhances satisfactory reoperation outcomes.

Notes: Restructured steaks were manufactured using hot- and cold-boned (HB, CB) beef with or without a combination of sodium alginate (0.6%), CaCO3 (0.01%) and encapsulated lactate (0.6%). Evaluation of textural changes during refrigerated (4C) storage for 72 h revealed that the CB treatment resulted in more rapid gelation (12 h) of the algin/calcium binders than the HB treatment (30 h). All comparisons of physical and sensory properties confirmed that the restructured treatments with binders had greater cohesiveness than the controls (no binder). Comparison of penetration and compression force measurements revealed that HB products had the same or lower values than CB samples for all raw or cooked treatments. Sensory evaluation of bind strength and hardness suggested that statistical differences between HB and CB products were eliminated by cooking the restructured steaks.

Notes: In Part I of this paper, two governing equations have been derived that describe the shape of a falling liquid sheet (a curtain) subjected to ambient pressure disturbances. These equations are termed varicose and sinuous. The varicose equation governs thickness variations in the curtain, for which the two air–liquid interfaces move exactly out of phase. The sinuous equation governs the deflection of the curtain centreline, i.e., the two air–liquid interfaces move in phase such that the local thickness of the liquid is preserved. To the order of the approximations used, the theory presented in Part 1 indicates that pressure disturbances invoke a sinuous curtain deflection with no varicose contribution. In Part 2 of this paper, the sinuous equation is verified by means of a localised pressure disturbance induced by an electrostatic field. After initiation, the propagation of this disturbance is followed and the shape of the air liquid interface is measured using a laser reflection technique. Both the generation and detection of the disturbance are non-contacting and therefore allow a precise verification of the equation. © 1997 American Institute of Physics.

Notes: We simulate the compression of a two-component Lennard-Jones liquid at a variety of constant temperatures using a molecular dynamics algorithm in an isobaric–isothermal ensemble. The viscosity of the liquid increases with pressure, undergoing a broadened transition into a structurally arrested, amorphous state. This transition, like the more familiar one induced by cooling, is correlated with a significant increase in icosahedral ordering. In fact, the structure of the final state, as measured by an analysis of the bonding, is essentially the same in the glassy, frozen state whether produced by squeezing or by cooling under pressure. We have computed an effective hard-sphere packing fraction at the transition, defining the transition pressure or temperature by a cutoff in the diffusion constant, analogous to the traditional laboratory definition of the glass transition by an arbitrary, low cutoff in viscosity. The packing fraction at this transition point is not constant, but is consistently higher for runs compressed at higher temperature. We show that this is because the transition point defined by a constant cutoff in the diffusion constant is not the same as the point of structural arrest, at which further changes in pressure induce no further structural changes, but that the two alternate descriptions may be reconciled by using a thermally activated cutoff for the diffusion constant. This enables estimation of the characteristic activation energy for diffusion at the point of structural arrest. © 1995 American Institute of Physics.

Notes: Restructured pork roasts were microwave cooked to an endpoint temperature of 73°C and evaluated for proximate composition, cooking loss and cooking time. Restructuring formulations were: (1) 0.75% salt and 0.2% phosphate (S/P), (2) S/P and 0.5, 1.0 or 2.0% carboxymethyl cellulose, (3) S/P and 0.5, 1.0 or 2.0% algin, and (4) 0.5, 1.0 and 2.0% algin with calcium carbonate and lactic acid added at a constant ratio of 6:1:1.5, respectively. The algin/calcium restructuring resulted in faster (P〈 0.05) cooking time and less cooking loss. Decreased cooking time was attributable to improved penetration and/or dispersion of microwaves. Algin/calcium restructuring may interest companies utilizing microwave energy to precook meats and to consumers desiring quickly prepared meals. More uniform microwave heating of pork could reduce the concern of ingesting viable trichinae or other pathogens.

Notes: Algin/calcium/myofibrillar protein gel interactions were investigated by modifying protein basic amino acids to an unreactive state and evaluating Instron texture profile (TP) of gels. Gels analyzed were: 1% algin and 0.075% CaCl2; 1% algin, 0.075% CaCl2 and 1.5% porcine myofibrillar protein (A/C/P); and A/C/P with lysine, histidine or arginine modified. The modification of amino acids reduced (P〈0.05) gel TP parameters of hardness, hardness 2, gumminess and chewiness. Similar TP data for protein modified gels indicated that each basic amino acid was involved in algin/protein gelation. Results provided evidence that ionic bonds between protein basic amino acids and algin carboxylate groups may be important for algin/myofibrillar protein gelation.

Notes: Rice flour and yellow or white corn flour were combined at 50, 60 and 70% levels with mechanically deboned turkey and extrusion processed at 104C and 121C. The texture of the extrudates was evaluated by Warner-Bratzler shear (WBS), and flour concentration had more effect on the WBS values than flour type; treatments with 70% flour had significantly greater WBS values. Corn flour treatments and low temperature extrusion resulted in greater TBA values. Proximate composition of extrudates confirmed moisture losses during extrusion and that high temperature processing had mixed results on ether-extractable compounds.