Holographic interferometry measurement of the thermal refractive index coefficient and the thermal expansion coefficient of Nd:YAG and Nd:YALO

Accurate values for the thermal expansion coefficient α and the thermal coefficient of refractive indexdn/dTare important in the design of a solid-state laser. This paper presents values of α anddn/dTthat were measured for Nd:YAG and Nd:YALO by a single-exposure holographic interferometry technique. The value of α for Nd:YAG agrees closely with that reported before, yet significantly different values ofdn/dTfor Nd:YAG and α for Nd: YALO were obtained. A discussion of the measurement techniques is given.     

Estimating frequency-response function using periodic signals and the f.f.t.

A technique for estimating a frequency-response function using a periodic pseudorandom binary sequence which is compatible with the fast-Fourier-transform algorithm is presented. A method of synchronising the p.r.b.s. and the sampling for the f.f.t. using a single clock source and two binary counters is described. A simple check on the synchronisations and the identification of an 8th-order lowpass Butterworth filter is provided.     

Surgical treatment of the massively dilated ureter in children. Part II. Management by primary reconstruction

Bypass of the left ventricle was accomplished in dogs and the entire circulation was supported temporarily by only the right ventricle. The atrial septum was excised, and the atrium was repartitioned so that the pulmonary veins were in continuity with the right ventricle and the venae cavae were connected through the atrium. Anastomosis of the superior vena cava to the right pulmonary artery brought systemic venous return directly to the lungs. The main pulmonary artery was ligated proximal to the bifurcation, preserving distal confluence of right and left pulmonary arteries. A tubular prosthesis between the proximal pulmonary artery and the aorta connected the right ventricle to the systemic circuit. This procedure, or some modification of the principle, may have clinical feasibility in the treatment of patients with hypoplastic left heart syndrome.     

Translocation of Escherichia coli from the gastrointestinal tract to the mesenteric lymph nodes in gnotobiotic mice receiving Escherichia coli vaccines before colonization

Germfree mice were immunized orally or intraperitoneally for 6 weeks with heat-killed vaccines of indigenous Escherichia coli or nonindigenous E. coli O 127: B8 before colonization with these strains. The mice exhibited increases in specific serum antibodies and intestinal immunoglobulin A reacting with the E coli antigens. Prior immunization did not reduce the gastrointestinal population levels of the E. coli strains attained 3 and 7 days after colonization. Neither oral nor intraperitoneal immunization with the E. coli strains before colonization decreased the incidence of bacterial translocation to the mesenteric lymph nodes or reduced the number of viable E. coli cells per mesenteric lymph node. There also was no relation in individual mice between serum antibody titers and the numbers of viable E. coli cells translocating to the mesenteric lymph nodes. Thus, prior vaccination with E. coli in this study did not decrease the incidence or reduce the numbers of viable E. coli translocating to the mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli.     

Placental proteins and steroid hormones in the soluble fraction of human syncytiotrophoblast plasma membrane

Placental protein 5 (PP5), pregnancy-specific glycoprotein (SP1), pregnancy-associated alpha 2-glycoprotein (SP3) and chorionic gonadotrophin could not be demonstrated in appreciable molar quantities in the soluble fraction from microvillous plasma membrane preparations isolated from the syncytiotrophoblast of full-term human placentae. However, progesterone, total oestriol and placental lactogen may have some association with this membrane.     

Measurement of integrated sensory-motor function following brain damage by a computerized preview tracking task

A preview tracking task has been developed which has particular application to neurological assessment and rehabilitation. Generated and monitored by a graphic display computer, it permits accurate global quantification of the upper-limb sensory-motor system. The incorporation of 'preview' into the tracking task is considered to significantly increase its effectiveness and relevance in relation to normal daily activities. Applied to three groups of normal subjects, several features of normal psychomotor performance and learning were identified or verified: hand dominance is not significant in overall arm control; learning does not completely plateau; increase in age (15-59 years) results in only a minor overall decrement in performance; an initial wide performance distribution decreases dramatically in subsequent sessions. Applied to brain-damaged patients, particularly head injury or stroke, the preview tracking task allows assessment at regular intervals enabling sensory-motor recovery curves to be generated. The potential of this technique, to help determine the efficacy of therapeutic procedures on the recovery process, is illustrated with the presentation of results from three brain-damaged patients demonstrating zero, significant and disjointed recovery of sensory-motor function. The usefulness of the preview tracking task can be expanded by combination with a less frequently applied but more component specific neurological assessment battery.     

Basic chemistry of a new cycle, based on reactions of Ce(III) titanate, for splitting water

The chemistry of a new thermochemical cycle for splitting water is described. It consists essentially of three reactions: (a) Ce(IV), as CeO₂, is reduced to Ce(III) by reaction with TiO₂, evolving oxygen and forming one or more Ce(III) titanates; (b) the Ce(III) titanates react with molten NaOH to evolve hydrogen, and form CeO₂ and Na-titanate; and (c) the sodium titanate is hydrolyzed by boiling water into a hydrous titanium dioxide and a sodium hydroxide solution. The cycle has been demonstrated with regenerated materials.