A cost-effective retractor and heart stabilizer for minimal-access coronary bypass

Exposure for internal mammary artery harvesting and immobilization of the coronary artery during the performance of minimally invasive direct coronary artery bypass grafting requires the use of appropriate retractors and instruments. We have successfully used existing retractors and instruments, modified for such use, which are reusable and cost effective. The use of such a retractor and cardiac stabilizer is described.     

Crystallization of glassforming melts under hydrostatic pressure and shear stress: Part I Crystallization catalysis under hydrostatic pressure: possibilities and limitations

This is the first part of a thorough study of the kinetics of melt crystallization under applied static pressure, P, and under shear stress. The thermodynamic and kinetic consequences of increased external pressure on nucleation rate, non-steady-state time lag, rate of crystal growth and overall crystallization kinetics in undercooled melts are analysed. Two types of undercooled liquids (with either positive or negative volume dilatation upon crystallization) are considered. Particular attention is given to the effect of pressure on the specific interface energy, σ, at the crystal/melt phase boundary. Using an appropriate thermodynamic model it is shown that for one-component systems, (∂σ/∂p)<0 is to be expected as a rule. Thus an additional decrease of the thermodynamic barrier of nucleation in pressurized melts is to be expected. However, it is also shown that the increase of melt viscosity with pressure in most cases reduces the effect of this decrease. Thus increased pressure has a limited effect as a nucleation catalyst. The possibilities in this respect are analysed and conditions under which static pressure may lead to enhanced crystallization are outlined. This revised version was published online in November 2006 with corrections to the Cover Date.     

An improved thick-film piezoelectric material by powder blending and enhanced processing parameters

This paper details improvements of the d33 co-efficient for thick-film lead zirconate titanate (PZT) layers. In particular, the effect of blending ball and attritor milled powders has been investigated. Mathematical modeling of the film structure has produced initial experimental values for powder combination percentages. A range of paste formulations between 8:1 and 2:1 ball to attritor milled PZT powders by weight have been mixed into a screen-printable paste. Each paste contains 10% by weight of lead borosilicate glass and an appropriate quantity of solvent to formulate a screen printable thixotropic paste. A d33 of 63.5 pC/N was obtained with a combination of 4:1 ball milled to attritor milled powder by weight. The improved paste combines the high d33 values of ball and the consistency of attritor milled powder. The measured d33 coefficient was further improved to 131 pC/N by increasing the furnace firing profile to 1000 degrees C, increasing the poling temperature to 200 degrees C, and using gold cermet and polymer electrodes that avoid silver migration effects and repeated firing of the PZT film.     

Osteomyelitis of the foot: relative importance of primary and secondary MR imaging signs

STUDY OBJECTIVES: Dyspnea is most commonly assessed by questioning patients about their subjective perception of shortness of breath during physical exertion. Although speech production is altered by pulmonary disease, it has not been included in current dyspnea assessment tools. A questionnaire was developed to address reports of dyspnea during (1) physical activity, (2) speech activity, and (3) simultaneous speech and physical activity. DESIGN: An equal number of self- and experimenter-administered 30-item questionnaires was given to 203 patients with restrictive and obstructive pulmonary diseases. Their responses were analyzed statistically. RESULTS: The questionnaire had high internal consistency for individual items within each of the three sections. The sections were highly correlated but provided separate and distinct information. Factors extracted from each section were related to severity of dyspnea. Pairwise t tests demonstrated highly significant differences in subject responses to the three sections. The least dyspnea was experienced during speech activities, more during physical activities, and the most when speech and physical activities were combined. CONCLUSIONS: The questionnaire proved to be a quickly administered tool for providing information about the effect of dyspnea on activities of daily living. Because of the emphasis on dyspnea during speech production, it may be particularly useful for assessing patients who rely extensively on speaking ability for their livelihood.     

Low-Reynolds-number translation of a slender cylinder near a plane wall

Summary Low-Reynolds-number results are presented for the drag and induced torque on a slender circular cylinder translating near a single plane wall. Four representative situations are investigated, the principal feature of the analysis being that it is valid for all distances from the wall which are large compared with the radius of the cylinder. In particular, the results hold for distances from the wall of the same order of magnitude as the length of the cylinder. The direction and rate of rotation are given for those cases where it occurs.This paper was written while N. J. de Mestre was a visitor at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge. W. B. Russel was supported by a NATO Postdoctoral Fellowship.     

Cure behavior of DGEBA vinyl ester–styrene resins near silane‐treated interfaces

An experimental technique using FTIR‐ATR was developed for monitoring the copolymerization behavior of a DGEBA‐based vinyl ester (VE) and styrene (ST) near the surface of a germanium internal reflection element. The data were compared to previously obtained bulk measurements of the cure behavior. It was found that the extent of conversion may be slightly greater for ST and slightly lower for VE near an untreated interface compared to the bulk. The cure behavior of VE–ST in the vicinity of a germanium IRE surface treated with a styryl amine silane (Dow Corning Z‐6032) was also investigated. In this case the effect on the cure was more dramatic, as exhibited by a more rapid consumption of ST compared to VE, thus resulting in a greatly reduced final conversion of VE double bonds compared to the bulk. These results suggest that, in glass fiber–reinforced composites, such sizings could significantly alter the composition of the crosslinked network in the vicinity of a fiber surface with the potential for a lower T_g interphase being formed that is rich in homopolymerized styrene. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2784–2792, 2006     

The contribution of psychologists to the treatment of plastic surgery patients.

Discusses the common interest in self-image of psychology and plastic surgery and suggests some possible roles for psychologists in the field of plastic surgery. Case examples are presented to illustrate the potential value of psychologists working in collaboration with plastic surgeons during each phase of the surgical endeavor, from presurgical assessment through perisurgical management through postsurgical adjustment. Case examples include a 42-yr-old male who requested sex reassignment surgery, a family in crisis after the birth of a child with facial deformities, an 8-yr-old boy with frontonasal dysplasia, and a 33-yr-old woman who could not adapt to her postsurgery appearance. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)