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A comprehensive investigation to determine the initiation power of detonators containing as a base charge the novel explosives: dihydroxylammonium 5,5′-bis(tetrazolate-1 N-oxide) - TKX-50, dihydroxylammonium 5,5′-bis(3-nitro-1,2,4-triazolate-1 N-oxide) - MAD-X1, pentaerythritol tetranitrocarbamate - PETNC and 3,3′-diamino-4,4′-azoxyfurazan - DAAF in comparison with RDX, HMX and PETN was undertaken. In order to estimate the initiation power of the detonators, the underwater initiating capability test was used. The total energy as a sum of the primary shock wave energy and the bubble gas energy was determined for each of these explosives, by measuring the overpressure of the shock waves generated in water. Moreover, the complete synthesis for novel explosives is presented. The thermal behavior of the explosives was investigated using DSC (differential scanning calorimetry). The gas phase absolute molar enthalpies at 298 K and 105 Pa were calculated theoretically using the modified complete basis set method (CBS-4M; M referring to the use of minimal population localization) with the Gaussian 09 software. Gas phase standard molar enthalpies of formation (Δ Hf°( g)) at 298 K were computed using the atomization energy method. Standard molar enthalpies of formation ( ▵H( s) °) were calculated using Δ Hf°( g) and the standard molar enthalpies of sublimation by applying Trouton's rule. The Chapman-Jouguet (CJ) characteristics based on calculated ▵H( s) ° values were computed using the EXPLO5 V6.01 thermochemical computer code. For the calculations the theoretical maximum densities and densities obtained during the experiments presented in this work were used. [ABSTRACT FROM AUTHOR]

Aims The aim of this study was to characterize left ventricular (LV) mechanics in symptomatic and asymptomatic patients with moderate-to-severe or severe aortic regurgitation (AR) and preserved ejection fraction (left ventricular ejection fraction) using two-dimensional speckle tracking echocardiography (2D-STE). The association between baseline LV strain and development of indications for surgery in asymptomatic patients was also evaluated. Methods and results Atotal of 129 patients with moderate-to-severe or severe ARand LVEF >50% (age 55 ± 17years, 64% male, 53% asymptomatic at baseline) were included. Standard echocardiography and 2D-STE were performed at baseline. Compared with asymptomatic patients, symptomatic patients had significantly impaired LV longitudinal ( -14.9 ± 3.0 vs. -16.8 ± 2.5%, P < 0.001), circumferential (-17.5 ± 2.9 vs. -19.3 ± 2.8%, P = 0.001), and radial (35.7 ± 12.2 vs. 43.1 ± 14.7%, P = 0.004) strains. Among49 asymptomatic patients who were followed up, 26 developed indications for surgery (symptoms onset or LVEF ≤50%). These patients had comparable LV volumes, LVEF, and colour Doppler assessments of AR jet at baseline, but more impaired LV longitudinal (P = 0.009) and circumferential (P = 0.017) strains compared with patients who remained asymptomatic. Impaired baseline LV longitudinal (per 1% decrease, HR = 1.21, P = 0.04) or circumferential (per 1% decrease, HR = 1.22, P = 0.04) strain was independently associated with the need for surgery. Conclusion Multidirectional LV strain was more impaired in symptomatic than in asymptomatic patients with moderate-to-severe or severe AR, despite preserved LVEF. In asymptomatic AR patients, longitudinal and circumferential strains identified patients who would require surgery during follow-up. [ABSTRACT FROM AUTHOR]

Quantitative assessment of aortic regurgitation (AR) remains challenging. The present study evaluated the accuracy of 2-dimensional (2D) and 3-dimensional (3D) transthoracic echocardiography (TTE) for AR quantification, using 3D 3-directional velocity-encoded magnetic resonance imaging (VE-MRI) as the reference method. Thirty-two AR patients were included. With color Doppler TTE, 2D effective regurgitant orifice area (EROA) was calculated using the proximal isovelocity surface area method. From the 3D TTE multiplanar reformation data, 3D-EROA was calculated by planimetry of the vena contracta. Regurgitant volumes (RVol) were obtained by multiplying the 2D-EROA and 3D-EROA by the velocity-time integral of AR jet and compared with that obtained using VE-MRI. For the entire population, 3D TTE RVol demonstrated a strong correlation and good agreement with VE-MRI RVol (r = 0.94 and -13.6 to 15.6 ml/beat, respectively), whereas 2D TTE RVol showed a modest correlation and large limits of agreement with VE-MRI (r = 0.70 and -22.2 to 32.8 ml/beat, respectively). Eccentric jets were noted in 16 patients (50%). In these patients, 3D TTE demonstrated an excellent correlation (r = 0.95) with VE-MRI, a small bias (0.1 ml/beat) and narrow limits of agreement (-18.7 to 18.8 ml/beat). Finally, the kappa agreement between 3D TTE and VE-MRI for grading of AR severity was good (k = 0.96), whereas the kappa agreement between 2D TTE and VE-MRI was suboptimal (k = 0.53). In conclusion, AR RVol quantification using 3D TTE is accurate, and its advantage over 2D TTE is particularly evident in patients with eccentric jets. [ABSTRACT FROM AUTHOR]

2,6-Bis(picrylamino)pyridine (1; pre-PYX) and 2,6-bis(picrylamino)-3,5-dinitropyridine (2; PYX) were synthesized using an improved literature method. Compounds 1 and 2 were reinvestigated in detail and the X-ray structures (1: ρ=1.698 g cm(-3) at 173 K; 2: ρ=1.757 g cm(-3) at 298 K) are given. The reactions of 2 with different bases, such as alkali metal hydroxides (sodium, potassium, rubidium, cesium), and N-bases (ammonia, hydrazine, hydroxylamine, guanidinium carbonate, aminoguanidine bicarbonate) are reported, as well as metathesis reactions producing energetic salts. Several energetic compounds were synthesized and characterized for the first time using vibrational (IR, Raman) and multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and DSC. The crystal structures of four energetic salts were determined using low temperature single-crystal X-ray diffraction. Heats of formation for the metal-free species were calculated using the Gaussian 09 software. Detonation parameters were estimated using the EXPLO5 program. The sensitivities towards impact, friction, and electrostatic discharge were also determined., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aims: The aim of this study was to characterize left ventricular (LV) mechanics in symptomatic and asymptomatic patients with moderate-to-severe or severe aortic regurgitation (AR) and preserved ejection fraction (left ventricular ejection fraction) using two-dimensional speckle tracking echocardiography (2D-STE). The association between baseline LV strain and development of indications for surgery in asymptomatic patients was also evaluated., Methods and Results: A total of 129 patients with moderate-to-severe or severe AR and LVEF >50% (age 55 ± 17 years, 64% male, 53% asymptomatic at baseline) were included. Standard echocardiography and 2D-STE were performed at baseline. Compared with asymptomatic patients, symptomatic patients had significantly impaired LV longitudinal (-14.9 ± 3.0 vs. -16.8 ± 2.5%, P < 0.001), circumferential (-17.5 ± 2.9 vs. -19.3 ± 2.8%, P = 0.001), and radial (35.7 ± 12.2 vs. 43.1 ± 14.7%, P = 0.004) strains. Among 49 asymptomatic patients who were followed up, 26 developed indications for surgery (symptoms onset or LVEF ≤50%). These patients had comparable LV volumes, LVEF, and colour Doppler assessments of AR jet at baseline, but more impaired LV longitudinal (P = 0.009) and circumferential (P = 0.017) strains compared with patients who remained asymptomatic. Impaired baseline LV longitudinal (per 1% decrease, HR = 1.21, P = 0.04) or circumferential (per 1% decrease, HR = 1.22, P = 0.04) strain was independently associated with the need for surgery., Conclusion: Multidirectional LV strain was more impaired in symptomatic than in asymptomatic patients with moderate-to-severe or severe AR, despite preserved LVEF. In asymptomatic AR patients, longitudinal and circumferential strains identified patients who would require surgery during follow-up., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

The synthesis, characterisation, and crystal structure determination of the closely related compounds 3,3'-bi-(5-trifluoromethyl-1,2,4-oxadiazole) and 5,5'-bi-(2-trifluoromethyl-1,3,4-oxadiazole) are reported. These two compounds are known for their bioactivity; however, in this study they serve as model compounds to evaluate the suitability of the heterocyclic oxadiazole ring system for energetic materials when the fluorine atoms in the exocyclic CF3 groups are substituted successively by nitro groups. Quantum chemical calculations for the bi-1,3,4-oxadiazole derivatives with difluoronitromethyl, fluorodinitromethyl, and trinitromethyl groups have been carried out and predict promising energetic performances for both explosive and propulsive applications., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aims: Despite a successful surgical procedure and adherence to current recommendations, postoperative left ventricular (LV) dysfunction after mitral valve repair (MVr) for organic mitral regurgitation (MR) may still occur. New approaches are therefore needed to detect subclinical preoperative LV dysfunction. LV global longitudinal strain (GLS), assessed with speckle-tracking echocardiographic analysis, has been proposed as a novel measure to better depict latent LV dysfunction. The aim of this study was to investigate the value of GLS to predict long-term LV dysfunction after MVr., Methods and Results: A total of 233 patients (61% men, 61 ± 12 years) with moderate-severe organic MR who underwent successful MVr between 2000 and 2009 were included. Echocardiography was performed at baseline and long-term follow-up (34 ± 20 months) after MVr. LV dysfunction at follow-up was defined as LV ejection fraction (EF) <50% and was present in 29 (12%) patients. A cut-off value of -19.9% of GLS showed a sensitivity and specificity of 90 and 79% to predict long-term LV dysfunction. By univariate logistic regression analysis, baseline LVEF ≤60%, LV end-systolic diameter (ESD) ≥40 mm, atrial fibrillation, presence of symptoms, and GLS >-19.9% were predictors of long-term LV dysfunction. By multivariate analysis, GLS remained an independent predictor of LV dysfunction (odds ratio 23.16, 95% confidence interval: 6.53-82.10, P < 0.001), together with LVESD., Conclusion: In a large series of patients operated within the last decade, MVr resulted in a low incidence of long-term LV dysfunction. A GLS of >-19.9% demonstrated to be a major independent predictor of long-term LV dysfunction after adjustment for parameters currently implemented into guidelines.