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Biomedical subjects

A P Boss

Publications and source records attributed to A P Boss.

4 recordsLinked to original sources

The early evolution of the inner solar system: a meteoritic perspective.

Formation of the solar system may have been triggered by a stellar wind. From then on, the solar system would have followed a conventional evolutionary path, including the formation of a disk and bipolar jets. The now extinct short-lived radionuclides beryllium-10 and, possibly, manganese-53 that were present in meteorites probably resulted from energetic particle irradiation within the solar system. Calcium-aluminum-rich inclusions (the oldest known solar system solids) and chondrules could have been produced by the bipolar jets, but it is more likely that they formed during localized events in the asteroid belt. The chondritic meteorites formed within the temperature range (100 to 400 kelvin) inferred for the midplane of classical T Tauri disks at 2 to 3 astronomical units from their central stars. However, these meteorites may retain a chemical memory of earlier times when midplane temperatures were much higher. Dissipation of the solar nebula occurred within a few million years of solar system formation, whereas differentiation of asteroidal-sized bodies occurred within 5 to 15 million years. The terrestrial planets took approximately 100 million years to form. Consequently, they would have accreted already differentiated bodies, and their final assembly was not completed until after the solar nebula had dispersed. This implies that water-bearing asteroids and/or icy planetesimals that formed near Jupiter are the likely sources of Earth's water.

Journal Article↗

Primary endoprosthesis in comminuted humeral head fractures in patients over 60 years of age.

The purpose of this study was to determine the early subjective and functional results after primary endoprosthesis replacement for comminuted humeral head fractures in patients over 60 years old. Twenty comminuted humeral head fractures in 20 patients were treated primarily (within 3.5 days (range 0-17 days) with a Neer II modular shoulder prosthesis, and were then followed up for an average of 32. 5 months (range 17-44 months). The average age of the patients was 77 years (range 63-91 years). The average post-operative Constant score was 52 points (range 30-76). This was significantly less than that of the contralateral side where the score was 80 points (range 53-100), P=0.0001. The average active abduction was 90 degrees (contralateral 157 degrees ) and active flexion 99 degrees (contralateral 161 degrees ). Eighteen of the 20 patients experienced relief of pain and would accept the same procedure again.

Activities of Daily Living↗