Peltier cooling and onsager reciprocity in ferromagnetic thin films.

We present direct measurements of the Peltier effect as a function of temperature from 77 to 325 K in Ni, Ni(80)Fe(20), and Fe thin films made using a suspended Si-N membrane structure. Measurement of the Seebeck effect in the same films allows us to directly test predictions of Onsager reciprocity between the Peltier and Seebeck effects. The Peltier coefficient Π is negative for both Ni and Ni(80)Fe(20) films and positive for the Fe film. The Fe film also exhibits a peak associated with the magnon drag Peltier effect. The observation of magnon drag in the Fe film verifies that the coupling between the phonon, magnon, and electron systems in the film is the same whether driven by heat current or charge current. The excellent agreement between Π values predicted using the experimentally determined Seebeck coefficient for these films and measured values offers direct experimental confirmation of the Onsager reciprocity between these thermoelectric effects in ferromagnetic thin films near room temperature.

Observation of the planar Nernst effect in permalloy and nickel thin films with in-plane thermal gradients.

We present experimental evidence of a transverse thermopower, or planar Nernst effect, in ferromagnetic metal thin films driven by thermal gradients applied in the plane of the films. Samples of 20 nm thick Ni and Ni(80)Fe(20) were deposited on 500 nm thick suspended Si-N thermal isolation platforms with integrated platinum strips designed originally to allow measurement of thermally generated spin currents (the spin Seebeck effect). The low thermal conductivity of the thin supporting Si-N structure results in an essentially 2D geometry that approaches the zero substrate limit, dramatically reducing the contribution of thermal gradients perpendicular to the sample plane typically found in similar experiments on bulk substrates. The voltage on the platinum strips generated transverse to the applied thermal gradient (V(T)) is linear with increasing ΔT and exhibits a sign reversal on hot and cold sides of the sample. However, V(T) is always even in applied magnetic field and shows a sinθ cosθ angular dependence, both key indicators of the planar Nernst effect. Within the 5 nV estimated error of our experiment there is no evidence of a signal from the spin Seebeck effect, which would have cosθ angular dependence, suggesting a reduced spin Seebeck coefficient in a planar, entirely thin-film geometry.

Small cell lung cancer in a patient with neutropenia due to Felty's syndrome.

A patient with severe neutropenia due to Felty's syndrome had limited stage small cell lung cancer, resulting in a therapeutic dilemma. Because he had a cellular bone marrow and no history of recurrent infection, we decided to administer full doses of cytotoxic chemotherapy with curative intent. A durable remission was achieved without complication, despite persistent severe peripheral neutropenia. It may be possible to administer aggressive chemotherapeutic regimens to selected patients with Felty's syndrome when there is the potential for cure of malignant disease.

Quality assurance today and tomorrow: forecast for the future.

We review here the definition, history, and current findings of quality assessment. Difficulties with quality assessment center principally on methods problems, including using the medical record as a source of information, using process versus outcome criteria, and ignoring decision analysis methods in establishing quality criteria. One overriding issue is placing a value on health and, by extension, on quality assurance and assessment efforts; another is the degree to which improvements in the quality of care can be achieved through changes in physician practices. Several sets of recommendations address these topics. With the assumption that such recommendations could be acted on in a transition period, a hypothetical quality assurance system is described for the 1980s and beyond. This system is based on preservation of the fee-for-service system, adoption of a national health insurance plan, and minimal federal involvement in quality of care decisions at the regional level.