Invoking the known link between impact sensitivity and compressibility, we have expanded upon an earlier preliminary study of the significance of the available free space per molecule in the unit cell, ΔV. We express ΔV as V(eff) - V(int), where V(eff) corresponds to zero free space, V(eff) = molecular mass/density. V(int) is the intrinsic gas phase molecular volume. We demonstrate that V(int) can be appropriately defined as the volume enclosed by the 0.003 au contour of the molecule's electronic density; this produces packing coefficients that have the range and average value found crystallographically. Measured impact sensitivities show an overall tendency to increase as ΔV becomes larger. For nitramines, the dependence upon ΔV is rather weak; we interpret this as indicating that a single overriding factor dominates their initiation mechanism, e.g., N-NO(2) rupture. (An analogous situation appears to hold for many organic azides.) In addition to the conceptual significance of identifying ΔV as a factor in impact sensitivity, the present results allow rough estimates of relative sensitivities that are not known.
We have investigated the possibility of a link between the impact sensitivities of energetic compounds and the space available to their molecules in their crystal lattices. As a measure of this space, we use Delta V=V(eff)-V(0.002), where V(eff) is the effective molecular volume obtained from the crystal density and V(0.002) is that enclosed by the 0.002 au contour of the molecule's gas phase electronic density, determined computationally. When experimental impact sensitivity was plotted against Delta V for a series of 20 compounds, the nitramines formed a separate group showing little dependence upon Delta V. Their impact sensitivities correlate well with an anomalous imbalance in the electrostatic potentials on their molecular surfaces, which is characteristic of energetic compounds in general. The imbalance is symptomatic of the weakness of the N-NO(2) bonds, caused by depletion of electronic charge. The impact sensitivities of non-nitramines, on the other hand, depend much more strongly upon Delta V, and can be quite effectively related to it if an electrostatically-based correction term is included.
- MeSH
- Physicians utilization MeSH
- Humans MeSH
- Job Description standards MeSH
- Foreign Professional Personnel utilization MeSH
- Check Tag
- Humans MeSH
- Publication type
- Newspaper Article MeSH
- Interview MeSH
- Geographicals
- Czech Republic MeSH
- Germany MeSH
Amiodaron je lékem užívaným v lékařské praxi již od roku 1962. Jeho účinky jsou dostatečně prozkoumány. Stejně tak jsou velmi dobře známy i jeho nežádoucí účinky. Ve světě i v ČR dochází k postupnému narůstání užívání tohoto léku. Spolu s narůstajícím počtem pacientů a spolu s narůstající délkou jejich léčby se zvyšuje počet zaznamenaných nežádoucích účinků. Tento článek podává jejich přehled, snaží se přiblížit mechanizmy vzniku nežádoucích účinků a předkládá postupy k jejich zvládnutí. Autoři zde diskutují nutnost vysazení amiodaronu a nebo možnost pokračování v terapii při jednotlivých typech nežádoucích účinků.
Amiodarone is an antiarrythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhytmias. It was registered by FDA in 1962. The effects of these drug are well known. The adverse effects are well known in the same way. The usage of amiodarone has gradually increased in the Czech Republic and in the world. The adverse effects has increased much the same as number of treated pacients. The authors present summary of all adverse effects, show mechanisms of their origin and discuss possibility of continuation of amiodarone therapy and the neccesity of discontinuation
Diagnóza infarktu myokardu je velmi přesně definována v rámci společného doporučení Evropské kardiologické společnosti a Amerických kardiologických společností (ESC/AHA/ACC). Nedílnou součástí diagnostiky je i subjektivní stav pacienta - stenokardie (7). Autoři ve svém sdělení předkládají případ, kdy vedoucím příznakem k zahájení další diagnostiky infarktu myokardu (IM) byl singultus.
- MeSH
- Diaphragm MeSH
- Diagnosis, Differential methods MeSH
- Adult MeSH
- Echocardiography MeSH
- Electrocardiography MeSH
- Myocardial Infarction diagnosis etiology therapy MeSH
- Middle Aged MeSH
- Humans MeSH
- Signs and Symptoms diagnosis MeSH
- Muscle Cramp MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Case Reports MeSH
- MeSH
- Adult MeSH
- Electrocardiography, Ambulatory MeSH
- Ventricular Fibrillation epidemiology MeSH
- Myocardial Infarction psychology radiation effects MeSH
- Interview, Psychological MeSH
- Middle Aged MeSH
- Humans MeSH
- Stress, Psychological MeSH
- Aged MeSH
- Exercise Test MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Aged MeSH
