Ultra-low oxygen, liquid sample cell for in situ synchrotron-based small-wide angle scattering (SAXS-WAXS).

Here, we report the design and successful implementation of an ultra-low oxygen sample cell for use on the SAXS-WAXS (small-wide angle x-ray scattering) beamline I22 at DIAMOND. The rigorous exclusion of oxygen is found to require double jacketing with purge gas throughout the entire system, pipework, pumps, and the sample cell itself. This particularly includes a "double-window" arrangement at the sample location to accommodate the very tight geometrical restrictions of the sample position. The in situ cell design also requires the additional complexity of heating the sample/solution and real-time electrochemical measurements. We demonstrate the successful implementation of this arrangement with real-time in situ characterization of an iron foil corrosion evolving under the "sweet-scale environment," very anoxic conditions common, in particular, commercial situations. The formation of iron carbonate, siderite, rather than iron oxide, indicates that our system is oxygen free down very low levels (<35 ppb at 80 °C).

Ultra-small-angle X-ray photon correlation spectroscopy using the Eiger detector.

Successful implementation of the single-photon-counting Eiger 500k pixel array detector for sub-millisecond X-ray photon correlation spectroscopy (XPCS) measurements in the ultra-small-angle scattering region is reported. The performance is demonstrated by measuring the dynamics of dilute silica colloids in aqueous solvents when the detector is operated at different counter depths, 4, 8 and 12 bit. In the fastest mode involving 4 bit parallel readout, a stable frame rate of 22 kHz is obtained that enabled measurement of intensity-intensity autocorrelation functions with good statistics down to the 50 µs range for a sample with sufficient scattering power. The high frame rate and spatial resolution together with large number of pixels of the detector facilitate the investigation of sub-millisecond dynamics over a broad length scale by multispeckle XPCS. This is illustrated by an example involving phoretic motion of colloids during the phase separation of the solvent.

Purification and characterization of cytochrome c6 from the unicellular green alga Scenedesmus obliquus.

Purification of a soluble cytochrome c6 from the unicellular green alga Scenedesmus obliquus by a simple and rapid method is described. The purification procedure includes ammonium sulfate precipitation and non-denaturating PAGE. The N-terminal sequence of the first 20 amino acids was determined and shows 85% similarity and 75% identity to the sequence of cytochrome c6 from the green alga Monoraphidium braunii. The ferrocytochrome shows typical UV/VIS absorption peaks at 552.9, 521.9 and 415.7 nm. The apparent molecular mass was estimated to be 12 kDa by SDS-PAGE. EPR-spectroscopy at 20 K shows resonances indicative for two distinct low-spin heme forms.

Evidence for nickel in the soluble hydrogenase from the unicellular green alga Scenedesmus obliquus.

Cultures of the green alga Scenedesmus obliquus were grown in the presence of either the chelating reagent EDTA or NiCl2 in various concentrations and assayed for hydrogenase catalyzed photohydrogen evolution after an anaerobic dark adaptation period. Cultivation of algae in the presence of 100 microM EDTA inhibited the formation of hydrogenase activity by 37%. After a cultivation of the cells in the presence of 5-20 microM NiCl2 photohydrogen evolution was increased by 20-40%. Addition of EDTA up to a final concentration of 1.5 mM had no effect on the activity of hydrogenase in cell-free hydrogenase preparations. Cultures grown in the presence of radioactive 63NiCl2 incorporated 63Ni in a parallel fashion to the cell growth. In radioactive labeled hydrogenase preparations a co-elution of radioactivity and hydrogenase activity could be observed using gel filtration chromatography.

Enabling technologies build bridge to 21st century.

The sophisticated healthcare institutions of the future will be computer-driven integrated clinical creatures. But which technologies are key to overall information access? Futurist Tim Zinn stalks tomorrow's "best of breed" I/S technologies.

Survey reveals portrait of today's healthcare CIO.

I/S executives in community hospitals across the United States have reason to celebrate! They are finally moving into the executive suite, with the titles, reporting status, staffing levels and salary to prove it.

Healthcare I/S executives look toward the next decade.

A survey of I/S executives conducted specifically for Computers in Healthcare reveals that the perception of the institutional mindset as leader, follower or average hospital makes a great deal of difference both in approach to I/S issues and in their relative priority.

Voice recognition: the key to hospital dominance.

Although still three to five years away, digitized voice recognition and input may hold the key to a comprehensive electronic patient clinical record and ultimately permit hospitals to retain their position as the depository of patient clinical data, according to healthcare futurist Tim Zinn.

HIS technology trends.

In the hospital information systems of the year 2000, futuristic technology will play a major role in managing the data needs of providers. Although systems managers face formidable challenges, they can make effective use of these new technologies by coordinating the roles of systems, personnel and planning in their own facilities.

Confronting 2000 and beyond: tomorrow's healthcare information system.

The promising healthcare information systems of tomorrow will be founded on strategies and technology that is already available today. In this article, Tim K. Zinn examines the information systems of the future, as well as the developments that will make such systems a reality.

Healthcare information systems as they evolve to the year 2000.

The revolution in healthcare information systems will continue in the next decade and beyond, with information becoming a more valuable source of quality control and cost savings for hospitals and other providers. In this article, Tim K. Zinn examines the future development of specific technologies, and discusses their impact on hospitals, systems suppliers and healthcare consultants.

Benchmarking system expectations.

Development of the first large, comprehensive HIS database started in 1982 at the University of Florida in Gainesville. The National Survey of Hospital Information Systems, initially an academic endeavor, launched a massive data collection effort. McGraw-Hill assumed ownership of this database, renaming it PROFILE in 1987.

Actualizing system benefits--Part IV.

Although hospitals continue to gain benefits from computerization, these benefits often fall short of expectations. Part IV of this series examines why department heads and administrators fail to achieve the kind of tangible, quantitative benefits that convinced them to buy information systems in the first place.