PubMed Health⌕ Search

Biomedical subjects

D Cline

Publications and source records attributed to D Cline.

At least 19 recordsLinked to original sources

Breakdown of K selection in 178Hf.

Coulomb activation of the four quasiparticle Kpi=16+ 178Hf isomer (t1/2=31 y) has led to the measurement of a set of Elamda matrix elements coupling the isomer band to the ground band. The present data combined with earlier 178 Hf Coulomb excitation data have probed the components in the wave functions and revealed the onset and saturation of K mixing in low-K bands, whereas the mixing is negligible in the high-K bands. The implications can be applied to other quadrupole-deformed nuclei.

Journal Article↗

Coulomb excitation paths of high-K isomer bands in 178Hf.

Three distinctly different mechanisms are shown to populate the K(pi)=6(+) (t(1/2)=77 ns), 16(+) (31 yr), and 8(-) (4 s) isomer bands of 178Hf by Coulomb excitation. High spin states of the three isomer bands were populated by Coulomb excitation of a hafnium target with a 650 MeV 136Xe beam. Although direct population of high-K bands is highly K-forbidden, isomer bands in 178Hf were populated up to spins 13(+)(K=6), 20(+)(K=16), and 14(-)(K=8) with in-band gamma yields of approximately 10(-4) of the ground state band. The data are consistent with a rapid increase in K mixing with increasing spin in the isomer bands.

Journal Article↗

Observation of plasma focusing of a 28.5 GeV positron beam.

The observation of plasma focusing of a 28.5 GeV positron beam is reported. The plasma was formed by ionizing a nitrogen jet only 3 mm thick. Simultaneous focusing in both transverse dimensions was observed with effective focusing strengths of order tesla per micron. The minimum area of the beam spot was reduced by a factor of 2.0+/-0.3 by the plasma. The longitudinal beam envelope was measured and compared with numerical calculations.

Journal Article↗

Level I trauma certification and emergency medicine resident major trauma experience.

OBJECTIVE: American College of Surgeons (ACS) and Residency Review Committee for Emergency Medicine (RRC-EM) guidelines conflict regarding the role of emergency physicians in directing major trauma resuscitations. This article describes the impact of ACS level I trauma certification on emergency medicine (EM) resident trauma experience. METHODS: A written survey and a follow-up letter were sent to all 101 EM program directors as of August 16, 1994. The survey addressed demographics and trauma experience at hospitals designated by the RRC-EM as primary training sites. RESULTS: There were 95 (94%) survey respondents. Estimates of the percentage of trauma resuscitations directed by EM residents were significantly lower at level I centers (52% +/- 27%, 95% CI 45-59%) than they were at non-level I centers (70% +/- 30%, 95% CI 58-82%) (p < 0.01). There was no significant difference in trauma census between level I and non-level I centers. Of 14 respondents who said they were cited by the RRC-EM for inadequate trauma experience, ten (71%) were in ACS level I trauma centers (p = 1.0). Twelve of the 14 respondents cited for inadequate trauma experience were in either the Northeast or the Midwest. CONCLUSIONS: EM residents direct a smaller percentage of major trauma resuscitations at ACS level I hospitals than they do at non-level I facilities. This finding is not offset by an increased trauma census at level I facilities and may be more pronounced in the Northeast and the Midwest.

Certification↗

Effect of a chiral impulse on the weak interaction induced handedness in a prebiotic medium.

Previously we have carried out simulation of the Weak Neutral Current and symmetry breaking transition bifurcation process addressing some of the issues raised by critics of the approach. We now include the effects of a chiral impulse on the transition and show that under certain cases this could greatly alter the transition time. Examples of a chiral impulse could be a nearby Supernova and an impulse of beta-emitters. We briefly discuss the possibility of these processes in the early solar system.

Biophysical Phenomena↗