Plasmonic Molecular Nanohybrids—Spectral Dependence of Fluorescence Quenching

We demonstrate strong spectral dependence of the efficiency of fluorescence quenching in molecular systems composed of organic dyes and gold nanoparticles. In order to probe the coupling with metallic nanoparticles we use dyes with varied spectral overlap between the plasmon resonance and their absorption. Hybrid molecular structures were obtained via conjugation of metallic nanoparticles with the dyes using biotin-streptavidin linkage. For dyes featuring absorption above the plasmon excitation in gold nanoparticles, laser excitation induces minute changes in the fluorescence intensity and its lifetime for both conjugated and non-conjugated mixtures, which are the reference. In contrast, when the absorption of the dye overlaps with the plasmon resonance, the effect is quite dramatic, reaching 85% and 95% fluorescence quenching for non-conjugated and conjugated mixtures, respectively. The degree of fluorescence quenching strongly depends upon the concentration of metallic nanoparticles. Importantly, the origin of the fluorescence quenching is different in the case of the conjugated mixture, as evidenced by time-resolved fluorescence. For conjugated mixtures of dyes resonant with plasmon, excitation features two-exponential decay. This is in contrast to the single exponential decay measured for the off-resonant configuration. The results provide valuable insight into spectral dependence of the fluorescence quenching in molecular assemblies involving organic dyes and metallic nanoparticles

Benefits of the selective invasive strategy guided by CTA and CT-FFR in patients with coronary artery disease

Background: Coronary computed tomography angiography (CTA) has high diagnostic accuracy in ruling out significant stenosis of coronary arteries. The additional use of CTA- derived FFR further enhances diagnostic utility of coronary CTA. Some of the patients interrogated non-invasively have diseased coronary arteries and undergo further diagnostic testing, including invasive coronary angiography (ICA). Patients with one vessel disease may benefit from invasive interrogation limited to the diseased vessel only. Aims: In 100 patients, we analysed the impact of a “diseased-vessel-only”, selective invasive diagnostic approach in patients undergoing ICA following coronary CTA (and CT-FFR) as compared to the traditional, “full ICA” approach. Our aim was to compare contrast volume and radiation dose used during ICA in both scenarios, seeking potential benefit for the patient in reducing those values by “diseased-vessel-only” approach. Results: Sensitivity, specificity, positive predictive value and negative predictive value of CTA in prediction of subsequent revascularization were 96%, 75%, 51% and 99%, respectively, and for CT-FFR 90%, 90%, 69% and 97%, respectively. Using CTA as a method to guide ICA would reduce contrast volume and estimated radiation dose (ED), by 35% and 42.0% respectively (P <0.0001 for both). Taking into consideration CT-FFR results, contrast volume would be reduced by 57% and ED by 69% (P <0.0001 for both). Conclusion: These real-world data support the concept that vessels with <50% diameter stenosis in QCT and hemodynamically insignificant in CTA-derived FFR may be skipped during ICA. Such approach would result in substantial reductions in contrast media volume used, as well as patient’s exposure to radiation during during ICA, while not leading to missed diagnoses

Estimation Complete Combustion Coefficient in Rotary Kilns

This paper presents a model-based analysis of variability of thermodynamic and chemical parameters in a rotary kiln (RK) during thermal treatment of animal waste. The core process of chemical treatment of waste takes place in RKs; the process involves heating, gasification and partial combustion of the waste. Control over these parameters, and especially the level of complete combustion, determines the quality and efficiency of the process. In operational practice, control and analysis of the variability of process parameters is complicated by the high degree of simultaneity of individual transformations, random disruptions of the process and metrological difficulties resulting from high temperature and chemical activity of the materials being processed. The purpose of preparing the model was to obtain a tool for predicting variability of selected process parameters. By definition, model calculations assume no influence of disturbances on output values, which makes it possible to acquire accurate results that can be compared with corresponding empirically obtained data. The result of the analyses conducted is a theoretical model of the analysed process and a graphical presentation of the calculation results in the form of graphs and charts. A formula for calculating the level of complete combustion and the results of calculation of this index on the basis of empirical data from an industrial waste incineration plant are also presented herein. The presented model is a useful tool providing an insight into interdependencies between selected process parameters and facilitating design of corrective actions oriented towards process optimisation

The nature of interactions of benzene with CF3I and CF3CH2I

Bujak M, Stammler H-G, Blomeyer S, Mitzel NW. The nature of interactions of benzene with CF3I and CF3CH2I. Chemical Communications. 2018;55(2):175-178

Severe tachycardiomyopathy and thrombus in the left atrial appendage - a case report

We describe a case of severe left ventricular (LV) heart failure caused by tachycardiomyopathy with concomitant presence of unsolved thrombus in left atrial appendage despite effective oral anticoagulant treatment. Successful ablation of atrial flutter and atrioventricular nodal reentry tachycardia entailed resolution of heart failure symptoms and normalisation of LV function. Kardiol Pol 2011; 69, 3: 294-29