BACKGROUND Symptomatic obstruction of long-segment tracheal or bronchial portions either related to congenital instability or secondary to vascular compression are rare malformations, which remain difficult to manage. A method of external tracheal or bronchial stabilization is described. METHODS From July 1992 to April 1995, 7 children (age range, 4 months to 4 years; mean age, 19 months) and...

To investigate the tribological interaction and wear mechanisms of polytetrafluoroethylene-lined radial lip oil seals in service, a sleeve, seal lubricant sample taken off rotating rig are studied. The test was terminated at 72 h, after severe leakage final 15 h test. All three components studied using coherence scanning interferometer environmental electron microscopy to testing. Results show ...

A state-of-the-art chamber facility is described for investigation of atmospheric aerosol chemistry. Dual 28 m3 FEP Teflon film chambers are used to simulate atmospheric conditions in which aerosol formation may occur. This facility provides the flexibility to investigate dark, single oxidant reactions as well as full photochemical simulations. This paper discusses the environmental control imp...

THz wave has been increasingly applied in engineering practice. One of its outstanding advantages is the penetrability through certain optically opaque materials, whose interior properties could be therefore obtained. In this report, we develop an experimental method to determine the plane stress state of optically opaque materials based on the stress-optical law using terahertz time-domain spe...

The Koch-Haaf reaction of adamantanols was successfully carried out in a microflow system at room temperature. By combining an acid-tolerant hastelloy-made micromixer, a PTFE tube, and a hastelloy-made microextraction unit, a packaged reaction-to-workup system was developed. By means of the present system, the multigram scale synthesis of 1-adamantanecarboxylic acid was achieved in ca. one hour...

We describe a case of infrarenal aortic hypoplasia in a 52-yr-old woman who presented with claudication. Computed tomographic angiography revealed an abrupt absence of the infrarenal aorta, with collateral flow reconstituting the iliofemoral systems. After a polytetrafluoroethylene graft was interposed between the aortic stump and the iliac bifurcation, the patient's claudication resolved.

In a liquid-liquid interface bioreactor, fungal cells locate in a hydrophilic polyacrylonitrile microsphere layer on an aqueous-organic interface. In this article, effects of hydrophobicity of the interface on n-decane hydroxylation activity of Monilliera sp. NAP 00702 was examined. (-)-4-Decanol production was significantly enhanced to 132% by addition of polytetrafluoroethylene.

A novel numerical method at the microscale for studying the mechanical behavior of an aluminum-particle-reinforced polytetrafluoroethylene (Al/PTFE) composite is proposed and validated experimentally in this paper. Two types of 2D representative volume elements (RVEs), real microstructure-based and simulated microstructures, are established by following a series of image processing procedures a...

Although there have not been any studies directly examining the rates and predictors of symptomatic non-remission or treatment resistance in patients with FEP in an Asian population, it is reasonable to deduce, based on current literature, that reducing DUP and achieving early symptomatic response are perhaps the most crucial modifiable factors in preventing treatment resistance and improving l...