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Biomedical subjects

R Ehrlich

Publications and source records attributed to R Ehrlich.

352 records · Page 20Linked to original sources

Response of microorganisms to a simulated Martian environment.

A study was undertaken to determine whether terrestrial microorganisms can survive in a simulated Martian environment. The ultimate objective is to establish whether earth organisms can contaminate Mars. In addition, any demonstration of survival and growth in a simulated Martian environment will provide information relating to the biology of Mars. In the experimental design, exhaustive consideration was given to the duplication of the known and the theoretical environmental parameters of Mars. These included composition of the soil and the atmosphere, barometric pressure, moisture content, solar radiation, and diurnal temperature extremes. Based upon these considerations, a simulated Martian summer environment was defined and used in the experiments. One group of microorganisms was selected from culture collections on the basis of their known characteristics. The other group was made of microorganisms isolated from soils. The soil samples were obtained from the Antarctic, from New Mexico, and California deserts, and from the Colorado tundra. The studies showed that a number of microorganisms can survive the simulated Martian environment. However, no substantial growth under such conditions could be demonstrated. The ability of microorganisms to form spores as a mechanism for survival will be discussed. Also, experiments utilizing augmented environments to establish minimum environmental conditions which will permit growth will be described.

Atmosphere↗

Evaluation of patients undergoing senning repair with two-dimensional contrast echocardiography.

The postoperative anatomy of the Senning interatrial diversion was defined by two-dimensional contrast echocardiography in ten patients. A modified apical four-chamber view proved most valuable, allowing for simultaneous visualization of both the systemic venous atrium and the pulmonary venous atrium. The anatomy was confirmed with two-dimensional contrast echocardiography utilizing catheters placed in the systemic venous atrium and pulmonary venous atrium at the time of surgery. In addition, in several of the patients, we were able to detect atrial or ventricular level shunts which were not clinically apparent. One patient who was judged to have a significant shunt by two-dimensional contrast echocardiography had no anatomic site found at autopsy to explain the shunting. We conclude that two-dimensional contrast echocardiography can define the postoperative anatomy following Senning repair allowing for immediate and future evaluation. Shunting at the atrial and ventricular levels can also be detected, but the method is very sensitive and difficult to quantitate or correlate clinically.

Child, Preschool↗

Biotech frontiers.

Researchers have wrought many new treatments for two growing fields of medicine: cardiovascular services and neurosciences.

Biotechnology↗