Modification of properties of yttria stabilized zirconia epitaxial thin films by excimer laser annealing.

This study focuses on the ultrafast improvement of surface wettability, electrical, and room temperature magnetic characteristics of cubic zirconia single crystalline thin films after laser annealing. The point defects generated by the laser treatment are envisaged to play a critical role in altering the above properties. Yttria stabilized zirconia (YSZ) thin films were epitaxially grown on Si(100) substrates by pulsed laser deposition technique and subsequently annealed by a KrF excimer laser beam (τ = 25 ns) using low-energy laser pulses. An atomically sharp interface, parallel to the film free surface, between laser annealed layer and the pristine region was observed. The single crystalline nature of thin films was preserved following the laser treatment. The laser-solid interaction with YSZ led to the introduction of point defects, i.e., oxygen vacancies, resulting in a strained structure which, in turn, resulted in the formation of a tetragonal-like zirconia. With the increase of number of laser pulses the laser treated films got highly disordered due to the high concentration of the point defects, while maintaining their crystalline nature. Although the surface of the pristine sample showed weak hydrophilic characteristics (contact angle ∼ 73°), the laser annealed samples exhibited significantly improved hydrophilic characteristics. It was found that there is an optimum number of laser pulses where the maximum hydrophilicity (contact angle ∼ 22°) is obtained. The carrier concentration in the sample with the highest hydrophilicity was determined to be higher by about 5 orders of magnitude compared to the pristine sample. This sample possessed the lowest electrical resistivity. The laser annealed YSZ epilayers showed a superior room-temperature ferromagnetic behavior, compared to the pristine samples. A 2-fold enhancement in the magnetization of the samples was observed following the laser treatment which is a clear demonstration of the key role of defects and their transient distribution throughout the lattice. All these observations were correlated with the formation of point defects due to the photon interaction with YSZ and absorption of energy of the KrF laser photons to produce defects.

The measurement of health in nursing research.

Health, a concept central to the discipline of nursing, was investigated to determine how it is operationalized in the nursing research literature. It was found that, in spite of extensive admonitions in most theoretical guides (which otherwise vary) not to do so, nurse researchers most often characterize health in research as the absence of illness, disability, or symptoms, and they frequently ignore multiple dimensions, eg, physical, mental, or sociological aspects, as well as the reliability and validity of the measures when assessing the health of subjects. Suggestions for advancing research on the concept of health consistent with theoretical beliefs are offered.

Lung carcinoid with Cushing's syndrome: control of serum ACTH and cortisol levels using SMS 201-995 (sandostatin).

Two patients with Cushing's syndrome due to lung carcinoid tumours were given the long-acting somatostatin analogue SMS 201-995 (Sandostatin). One received a single 50 micrograms dose which produced a 50% reduction in circulating ACTH levels within 4 h. The other has been maintained in clinical and biochemical remission for 10 weeks on 100 micrograms tid. This is the first report of the successful use of SMS 201-995 in carcinoid-induced Cushing's syndrome, and suggests that this hormone analogue could be valuable in the long term medical management of such patients.

A new total substitute urinary bladder.

A surgical technique for the creation of an antireflux reservoir type substitute urinary bladder using the distal part of the ileum and aimed at meeting the demands expected of its normal counterpart is presented. Two male patients who underwent radical cystoprostatectomy with pelvic node dissection without urethrectomy for transitional cell carcinoma of the bladder are discussed herein. Variations in the creation of the reservoirs in both patients are described and the preliminary results reported.

Construction of natural appearing female genitalia in the male transsexual.

A surgical technique is presented which gives an excellent appearance and functional result in male-to-female transsexual conversion of genitalia. The complications have been few, and the conversion is done in one operation.

Thermodynamic considerations of the setting reaction in Ag3Sn amalgams.

The setting reaction of Ag3Sn amalgams may be thought of as a liquid phase sintering problem in which the reactants seek to form products with the lowest thermodynamic potential. We discuss the thermodynamic and kinetic considerations of this reaction. The lowering of free energy has been given as the reason for the formation of the gamma1, gamma2,and beta1 phases and a qualitative reaction coordinate diagram has been hypothesized. The barrier height for the formation of the beta1 phase has been determined to be 137 kJ/mol.