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Notes: We report ab initio calculations of the ground state energy for 404 new conformations of H3, supplementing the set of 368 conformations reported previously by others. The entire dataset has been used to constrain an analytical functional form for the potential energy surface, building on that of Truhlar and Horowitz. The new surface extends the Truhlar and Horowitz surface to higher energies and offers some modest improvement at lower energies. In addition, we have eliminated a problem with derivatives of the London equation that was pointed out by Johnson. The new surface matches the 772 ab initio energies with an overall root-mean-square (rms) error of 0.25 mhartree (i.e., 0.16 kcal/mol) and a maximum absolute deviation of 1.93 mhartree (1.21 kcal/mol); for "noncompact'' conformations (no interatomic distance smaller than 1.15 bohr), the rms error is 0.17 mhartree (0.11 kcal/mol) and the maximum absolute deviation is 1.10 mhartree (0.69 kcal/mol). The classical barrier height for H+H2→H2+H is estimated to be 15.20±0.15 mhartree (i.e., 9.54±0.09 kcal/mol).

Notes: The interaction potential energy surface (PES) of H4 is of great importance for quantum chemistry, as a test case for molecule–molecule interactions. It is also required for a detailed understanding of certain astrophysical processes, namely, collisional excitation and dissociation of H2 in molecular clouds, at densities too low to be accessible experimentally. Accurate ab initio energies were computed for 6046 conformations of H4, using a multiple reference (single and) double excitation configuration interaction (MRD-CI) program. Both systematic and "random'' errors were estimated to have an rms size of 0.6 mhartree, for a total rms error of about 0.9 mhartree (or 0.55 kcal/mol) in the final ab initio energy values. It proved possible to include in a self-consistent way ab initio energies calculated by Schwenke, bringing the number of H4 conformations to 6101. Ab initio energies were also computed for 404 conformations of H3; adding ab initio energies calculated by other authors yielded a total of 772 conformations of H3. (The H3 results, and an improved analytic PES for H3, are reported elsewhere.) Ab initio energies are tabulated in this paper only for a sample of H4 conformations; a full list of all 6101 conformations of H4 (and 772 conformations of H3 ) is available from Physics Auxiliary Publication Service (PAPS), or from the authors.The best existing analytic PESs for H4 are shown to be accurate only for pairs of H2 molecules with intermolecular separations greater than about 3 bohr (1.6 A(ring)). High energy collisions (such as might lead to direct collisional dissociation) cannot be well represented by such surfaces. A more general analytic PES for H4 is required, which will be accurate for compact (high-energy) conformations and for conformations that cannot be subdivided into a pair of H2 molecules. Work in progress on devising such a surface (fitted to the 6101 conformations of this work) will be reported in a forthcoming paper.

Notes: From 1977 to 1986, 264 women with stage I or II breast cancer and positive breast cancer family histories were treated with conservative surgery, axillary dissection, and irradiation. The records of these cases were reviewed and compared to those of 517 women with stage I or II breast cancer and negative breast cancer family histories who were treated similarly during the same time period. Patients with a negative family history were more likely to present with positive axillary lymph nodes than patients whose history was positive (33% vs. 26.5%, p = 0.054). There were no statistically significant differences found between the family history positive and family history negative women in terms of 5 and 10 year actuarial overall survival (5 yr: 91% vs. 90%, 10 yr: 86% vs. 82%) or relapse-free survival (5 yr: 76% vs. 76%, 10 yr: 64% vs. 61 %). Breast recurrence rates were likewise not significantly different for the two groups of patients (5 yr: 6% vs. 9%, 10 yr: 17% vs. 18%). A separate analysis restricted to lymph node-positive patients revealed no significant differences in survival between the family history positive and family history negative groups. It thus appears that women with early stage breast cancer who have a family history of the disease can be treated with breast-conserving surgery and definitive irradiation with the same excellent results as seen in women without such a family history.

Notes: Telemetry is done in a variety of settings with different levels of sophistication. The American College of Cardiology has made suggestions for telemetry monitoring but these are not in place in many smaller community hospitals that do telemetry monitoring. The objective of this study was to compare prospectively telemetry without a dedicated monitor watcher or full disclosure to results obtained on full disclosure. Patients included were admitted to a single community hospital with an indication for telemetry as judged by their primary physician. Telemetry results reported by the hospital staff were compared to over-read of full disclosure traces by an academic cardiology service and the patient was used as his own control. Significant rhythm disturbances including pauses of 2 seconds or greater and short runs of ventricular and supraventricular tachycardia were frequently missed when a dedicated monitor watcher and full disclosure were not in use. When a dedicated monitor watcher and full disclosure are not in use, telemetry results should be accepted with caution and attempts should be made to improve monitoring. A.N.E. 2002;7(3):219–221 telemetry; full disclosure; dedicated monitor watcher

Notes: Abstract:  Background: National rates of cesarean birth continue a three decade-long escalation, despite widespread recognition that a reduction in the use of the procedure is a continuing appropriate public health goal, as evidenced by the Healthy People 2010 reduction targets. Nonclinical factors associated with cesarean delivery include maternal age, race, socioeconomic status, and insurance coverage. This study compared cesarean delivery rates and trends for the U.S. Department of Defense healthcare beneficiary population from 1996 to 2002 with those observed nationally, and assessed the association of these nonclinical factors with cesarean rate variation in the U.S. Department of Defense healthcare beneficiary population. Methods: Hospital discharge and claims records for babies born in the military and civilian hospitals that comprise the Department of Defense healthcare network were used to calculate total and primary cesarean delivery rates and vaginal birth after cesarean (VBAC) rates from 1996 to 2002. Annual cesarean rates for subgroups defined by maternal age, race, and socioeconomic status were calculated to examine rate variations and rate trends within the study population. Pooled data from 1999 to 2002 were used to compare rates across socioeconomic status, stratified by age and race. Statistical significance of the differences calculated for subgroups was assessed using chi-square. Results: Total and primary cesarean delivery rates among the U.S. Department of Defense population were lower than those reported nationally for every year examined. Cesarean delivery and VBAC rate trends in the national and Department of Defense populations were similar. Within the Department of Defense population, total cesarean delivery increased with increasing maternal age and was more highly associated with racial minorities relative to white women. The higher socioeconomic subgroup (defined as active duty, retired, and warrant officers and their families in this study) was generally associated with reduced cesarean delivery rates. Conclusions: Cesarean deliveries are performed less frequently for the U.S. Department of Defense healthcare beneficiary population relative to the national population. Associations between socioeconomic factors and cesarean rates reported for the national population were not apparent in the study population. The consistent pattern of rate variation across racial subgroups in the Department of Defense population suggests that factors beyond those examined in this study are needed to explain the elevated cesarean rates for racial minorities. (BIRTH 31:1 March 2004)