Biomedical subjects

A Cabanas

Publications and source records attributed to A Cabanas.

3 recordsLinked to original sources

PubMed2001

Deposition of conformal copper and nickel films from supercritical carbon dioxide.

Device-quality copper and nickel films were deposited onto planar and etched silicon substrates by the reduction of soluble organometallic compounds with hydrogen in a supercritical carbon dioxide solution. Exceptional step coverage on complex surfaces and complete filling of high-aspect-ratio features of less than 100 nanometers width were achieved. Nickel was deposited at 60 degrees C by the reduction of bis(cyclopentadienyl)nickel and copper was deposited from either copper(I) or copper(II) compounds onto the native oxide of silicon or metal nitrides with seed layers at temperatures up to 200 degrees C and directly on each surface at temperatures above 250 degrees C. The latter approach provides a single-step means for achieving high-aspect-ratio feature fill necessary for copper interconnect structures in future generations of integrated circuits.

Journal Article↗

PubMed1980

Effects of ketamine and halothane on normal and asthmatic smooth muscle of the airway in guinea pigs.

In vitro preparations of trachea isolated from normal and asthmatic guinea pigs were used to measure their maximum contractile response to histamine challenge and to determine spontaneous relaxation of smooth muscle of the airway. The effect of ketamine and halothane on these reactions was investigated. The optimal ketamine concentration was found to be 10 micrograms/ml. This dose attenuated the maximum contraction and produced greater relaxation (p less than 0.01) of isolated trachea. However, ketamine failed to prevent an anaphylactic (Schultz-Dale) response when antigen (one per cent albumin) was added in an experimental chamber containing pre-sensitized guinea pig trachea. In contrast, halothane abolished any response to histamine challenge and prevented development of the Schultz-Dale response of smooth muscle from the airway of asthmatic guinea pigs.

Anaphylaxis↗

PubMed1977

A procedure for dissociating Ayre scrape samples.

The dissociation of cervical cell suspensions after various chemical and enzymatic treatments was monitored by using the Centrifugal Cytology rotor to produce glutaraldehyde-fixed dispersions on conventional microscope slides and subsequent Pap staining. A special program was written in RPG II to record and analyze the results of the dissociation experiments in terms of white blood cells and the true cervical cells ("other cells"), and the degree of dissociation and recovery of both classes of cells. Since accurate differential counts on the untreated Ayre scrapes were difficult, the samples were syringed gently to break up the large or adventitious clumps. Cumulated results from control preparations indicate that the white blood cells and "other cells" are composed respectively of 92 and 63% single cells. The cells were further dissociated by: dissolving the cervical mucin sequentially with dithiothreitol and iodoacetic acid; depolymerizing the nucleohistone gel with ribonuclease; solubilizing the desmosomes with EDTA; removing the remaining cellular agglutinins with Varidase; and finally mechanical dispersion by hypertonic shock. The optimum procedure for dissociation involves the use of ribonuclease, dithiothreitol, iodoacetic acid EDTA, Varidase and sucrose shock. The white blood cells are now monodisperse and 81% of the "other cells" are found as single cells. If nuclear separation by two diameters is considered sufficient 98% of the "other cells" are single. The slide preparations are now sufficiently good that a scanning system is feasible.

Autoanalysis↗