Electrochemically Generated Luminescence of Luminol and Luciferin in Ionic Liquids

Electrochemiluminescence (ECL) is the generation of light triggered by an electrochemical reaction. ECL has been extensively studied in solvent-based electrolytes, but there is a lack of data on using electrode reactions to populate an excited-state light emitter in room temperature ionic liquids (RTILs). This work explores the current response, light intensity (photon counting), and spectral signatures of the cathodic ECL of luminol and firefly's luciferin in imidazolium-based RTILs. We have demonstrated that the cathodic (superoxide-triggered) ECL of both luminol and adenylate-ester of firefly's luciferin is viable in RTILs, explored the effect of water contaminations, and importantly, shown that the ECL signal persists for up to about 700 s after the removal of the external cathodic pulse, which is probably due to the stabilization of superoxide by double-layer cation-rich structures. Long-lived RTIL double-layer structures and their endogenous fields are detected as stable and discrete open-circuit potential plateaus

Luciferase-free Luciferin Electrochemiluminescence

Luciferin is one of Nature's most widespread luminophores, and enzymes that catalyze luciferin luminescence are the basis of successful commercial “glow” assays for gene expression and metabolic ATP formation. Herein we report an electrochemical method to promote firefly's luciferin luminescence in the absence of its natural biocatalyst—luciferase. We have gained experimental and computational insights on the mechanism of the enzyme-free luciferin electrochemiluminescence, demonstrated its spectral tuning from green to red by means of electrolyte engineering, proven that the colour change does not require, as still debated, a keto/enol isomerization of the light emitter, and gained evidence of the electrostatic-assisted stabilization of the charge-transfer excited state by double layer electric fields. Luciferin's electrochemiluminescence, as well as the in situ generation of fluorescent oxyluciferin, are applied towards an optical measurement of diffusion coefficients

Diabetic foot infections: a team-oriented review of medical and surgical management

As the domestic and international incidence of diabetes and metabolic syndrome continues to rise, health care providers need to continue improving management of the long-term complications of the disease. Emergency department visits and hospital admissions for diabetic foot infections are increasingly commonplace, and a like-minded multidisciplinary team approach is needed to optimize patient care. Early recognition of severe infections, medical stabilization, appropriate antibiotic selection, early surgical intervention, and strategic plans for delayed reconstruction are crucial components of managing diabetic foot infections. The authors review initial medical and surgical management and staged surgical reconstruction of diabetic foot infections in the inpatient setting

Evolution of the dislocation structure during compression in a Mg-Zn-Y alloy with long period stacking ordered structure

Evolution of the dislocation structure in Mg97Y7Zn5 (at. %) alloy having long period stacking ordered (LPSO) structure was studied during compression tests. Two materials, an as-cast and an extruded one were deformed up to the applied strain of ~25%. The evolution of the crystallite size, the dislocation density and the population of the particular slip systems were determined by the evaluation of the X-ray diffraction peak profiles. A very low dislocation density with the order of magnitude 1012–1013 m−2 was detected in the compressed specimens. This dislocation density did not increase considerably with increasing strain. At the same time, a significant decrease of the crystallite size occurred during compression. These observations can be explained by the arrangement of dislocations into low energy dipolar configurations, such as kink walls, which do not contribute to the dislocation density measurable by X-ray diffraction peak profile analysis, however they yield a fragmentation of the crystallites.The authors are grateful for the support of the Czech Grant Agency under grant Nr. 16-12075S. This work was supported by the Hungarian Scientific Research Fund, OTKA, Grant no. K-109021.Peer Reviewe

Comparative study between dexmedetomidine-ketamine and fentanyl-ketamine combinations for sedation in patients undergoing extracorporeal shock wave lithotripsy. A randomized double blinded study

Background and objectives Extracorporeal shock wave lithotripsy (ESWL) is used safely for management of urinary stones. The aim of this randomized double blinded study was to compare the effects of dexmedetomidine-ketamine and fentanyl-ketamine combinations on analgesia, sedation, hemodynamics and respiratory effects in patients underwent ESWL. Methods: Sixty patients aged between 20 and 50 years, ASA I or II physical status were randomly assigned into two groups. In Group Fentanyl-ketamine (FK) (n = 27): Patients received fentanyl at a 1 μg/kg over 10 min before the procedure and 0.5 mg/kg bolus of ketamine. In Group Dexmedetomidine-ketamine DK (n = 30): patients received dexmedetomidine 1 μg/kg over 10 min before the procedure and a 0.5 mg/kg bolus of ketamine. A blinded researcher assessed the patient’s pain level (primary outcome), sedation level, and awareness via visual analogue scale (VAS), modified Observer’s Assessment Alertness/sedation, and bispectral index respectively. Results: There was a significant increase in VAS in the recovery period in FK group. There was a significant decrease in hemodynamics (HR, MAP) in the recovery period in DK group. There was a significant increase in bispectral index values in FK group during the postoperative period. The first analgesia required was significantly longer in DK. There was a significant increase in sedation score in the recovery period in FK group. There was no significant difference between the two groups as regards the adverse effects except nausea and vomiting (significant in FK group). Conclusion: Dexmedetomidine/ketamine combination was accompanied by more prolonged analgesia in the recovery period, prolonged sedation, and delayed request of first dose analgesia with less nausea and vomiting than fentanyl/ketamine combination