PR separations of band envelopes produced by prolate and oblate top molecules

A study of PR separations produced by a relatively large number of prolate and oblate asymmetrical top molecules reported in the literature revealed that under certain conditions the branch separations of type A(z.snfc;), type B() and type C() bands (prolate molecules) are in the proportion of 1:1/S(ß):3/2 whereas the separations produced by type A(), type B() and type C(z.snfc;) bands (oblate molecules) are in the proportion of :1/S(ß):1 and ::1 for planar oblate compounds. The branch separation of the parallel bands is found to obey the relation: Δν(PR) = 10S(ß)(BT/9)1/2 cm−1 For * and −1 χ +1 the proposed ξ values fairly match those as calculated by Gerhard and Dennsion and Badger and Zumwalt as well. The method of predicting branch separations is therefore simplified while the agreement with the values observed by experiment is quite satisfactory

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used