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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

NASA/DoD Aerospace Knowledge Diffusion Research Project. XXVII - Knowledge diffusion and U.S. government technology policy: Issues and opportunities for sci/tech librarians

Federal involvement in stimulating economic growth through the development and application of technology policy is currently the subject of serious debate. A recession and the recognition that an internationally competitive economy is a prerequisite for the attainment of national goals have fostered a number of technology policy initiatives aimed at improving the economic competitiveness of American industry. This paper suggests that the successful implementation of U.S. technology policy will require the adoption of a knowledge diffusion model, the development of user oriented information products and services, and a more 'activist' approach on the part of sci/tech librarians in the provision of scientific and technical information (STI). These changes will have a dramatic impact on the sci/tech library of the future and the preparation of sci/tech librarians.

Pinelli, Thomas E.↗
DOE OSTI2018

Hemoglobin crystals immersed in liquid oxygen reveal diffusion channels

Highlights: • Crystal structure of Human Hemoglobin were solved after immersion in liquid oxygen. • Immersion in liquid oxygen oxidizes the heme-center revealing aquomethemoglobin. • Immersion in liquid oxygen also reveals the footprints of oxygen channels. • These channels contain medically relevant mutations that modulate oxygen affinity. Human hemoglobin (HbA) transports molecular oxygen (O{sub 2}) from the lung to tissues where the partial pressure of O{sub 2} is lower. O{sub 2} binds to HbA at the heme cofactor and is stabilized by a distal histidine (HisE7). HisE7 has been observed to occupy opened and closed conformations, and is postulated to act as a gate controlling the binding/release of O{sub 2}. However, it has been suggested that HbA also contains intraprotein oxygen channels for entrances/exits far from the heme. In this study, we developed a novel method of crystal immersion in liquid oxygen prior to X-ray data collection. In the crystals immersed in liquid oxygen, the heme center was oxidized to generate aquomethemoglobin. Increases of structural flexibility were also observed in regions that are synonymous with previously postulated oxygen channels. These regions also correspond to medically relevant mutations which affect O{sub 2} affinity. The way HbA utilizes these O{sub 2} channels could have a profound impact on understanding the relationship of HbA O{sub 2} transport within these disease conditions. Finally, the liquid oxygen immersion technique can be utilized as a new tool to crystallographically examine proteins and protein complexes which utilize O{sub 2} for enzyme catalysis or transport.

60 APPLIED LIFE SCIENCES↗