The influence of sex on the relationship between heart rate recovery and other cardiovascular risk factors in apparently healthy subjects.

Heart rate recovery (HRR) is an important indicator of cardiovascular health. The purpose of the present investigation is to examine the influence of sex on the relationship between HRR and other markers of cardiovascular health. Two hundred and seventy-five apparently healthy subjects participated in this study. Subjects underwent cardiopulmonary exercise testing (outcome measures: VO(2max) and HRR 1 and 2 min into recovery), lipid analysis, measurement of resting systolic and diastolic blood pressure and measurement of aortic wave velocity (AWV in m/s) via magnetic resonance. HRR both at 1 min (HRR(1)) and at 2 min (HRR(2)) were higher in males. In general, the correlation between HRR(1) and other measures of interest was weaker than that found with HRR(2) in both male and female subjects. With respect to HRR(2), the relationship with other measures of interest was stronger in the female subgroup. Specific to arterial stiffness, the correlation between HRR(2) and AWV was -0.33 and -0.46 (P<0.001 for both) in male and female subgroups, respectively. The results of the present study indicate that both gender and the timing of HRR measurement influence its relationship with other important cardiovascular risk factors.

HMX based enhanced energy LOVA gun propellant.

Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 degrees C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 microm HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.

Trace metal assay of U(3)O(8) powder by electrothermal AAS.

Methods have been developed for the direct determination of Ag, Ca, K., Li, Mg, Na, Pb, Sn and Zn in U(3)O(8) powder samples by electrothermal AAS. Nanogram and lower amounts of these elements have been determined with a relative standard deviation of 6-16% in mg amounts of sample (either alone or mixed with an equal weight of graphite). The results for NBL reference samples were in reasonable agreement with the certified values. X-Ray diffraction studies on the residues left from the graphite mixtures after the atomization cycle, confirmed the formation of uranium carbide (UC(2)).