Continuous supercritical synthesis of high quality UV-emitting ZnO nanocrystals for optochemical applications

ZnO nanocrystals (NCs) are of increasing interest in many industrial applications especially in the field of optochemical sensors. We recently demonstrated the synthesis of excitonic luminescent ZnO NCs using the perfectly controlled environment offered by supercritical microfluidics. However, the limited production rates of such a microscale synthesis approach make it essential to develop scaled-up continuous supercritical synthesis processes. Here, we investigate the influence of the scale-up effect from continuous microfluidic up to millifluidic systems over the synthesized ZnO NCs' optical properties. We also propose to discuss the influence of reactor's dimensions, as a consequence of different hydrodynamics regimes, on the characteristics of ZnO NCs. The obtained ZnO NCs have various shapes depending on the considered set-up. A strong excitonic-only emission in the UV region in room temperature photoluminescence (PL) spectra is obtained from all types of reactors, demonstrating the success of the scale-up process for higher production rates (up to 100 mg per hour)

Continuous supercritical synthesis of high quality UV-emitting ZnO nanocrystals for optochemical applications

ZnO nanocrystals (NCs) are of increasing interest in many industrial applications especially in the field of optochemical sensors. We recently demonstrated the synthesis of excitonic luminescent ZnO NCs using the perfectly controlled environment offered by supercritical microfluidics. However, the limited production rates of such a microscale synthesis approach make it essential to develop scaled-up continuous supercritical synthesis processes. Here, we investigate the influence of the scale-up effect from continuous microfluidic up to millifluidic systems over the synthesized ZnO NCs' optical properties. We also propose to discuss the influence of reactor's dimensions, as a consequence of different hydrodynamics regimes, on the characteristics of ZnO NCs. The obtained ZnO NCs have various shapes depending on the considered set-up. A strong excitonic-only emission in the UV region in room temperature photoluminescence (PL) spectra is obtained from all types of reactors, demonstrating the success of the scale-up process for higher production rates (up to 100 mg per hour)

Luminescence of sensitive materials: towards new optical sensing

In the last decades, considerable efforts have been carried out to develop new tools and knowledge in the domain of functionalized materials, for application ranging information, lighting, communication, energy, optical sources or detection. To couple an optical answer with another property is possible through the follow-up of the luminescence. The control of the structural symmetry, oxidation state or surface chemistry enables the chemists to precisely tune the emission. Illustrations will be provided on inorganic powder and crystal materials

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)