The Chaîne Opératoire of Middle Kingdom smelting batteries and the problem of fuel: excavation, experimental and analytical studies on ancient Egyptian metallurgy

Material Culture Studie

Geochemical changes during Egyptian copper smelting? An experimental approach to the Ayn Soukhna process and broader implications for archaeometallurgy

This paper presents the results of comprehensive geochemical analysis of experimental copper smelting products. An iterative, long-term experimental programme has been incorporated in the ongoing excavation of Middle Kingdom metallurgy remains at Ayn Soukhna (Egypt) in order to better understand the copper production chain at the site. The integration of archaeometry into this research methodology has enabled a detailed understanding of the geochemical changes which may occur during copper smelting in furnaces of this type. These include significant elemental fractionation, as well as important shifts in lead isotope ratios between ores and end products (slag and copper). This research presents an interpretative framework not only for understanding production waste from Ayn Soukhna itself, but more broadly the provenance and technology of copper alloys circulating in ancient Egypt. The significant shifts in lead isotope ratios observed for an experimental low-lead copper smelting system are highly relevant here, given the similar composition of many Sinai and Eastern Desert ores exploited throughout Pharaonic history. However, the implications of this research may be extrapolated beyond Egypt to low-lead copper provenance research across the ancient world and thus provide an important new methodological perspective for archaeometallurgy more generally. Furthermore, limitations to using iron in copper artefacts as a guide for their production technology are pointed out. Similar iron contents are observed for woodand charcoal-based smelting systems, inviting a reappraisal of fuel use at ancient metal production contexts in Egypt and elsewhere. A research approach integrating excavation, experimentation and analysis is essential when confronting the complexity of production chains underlying Egyptian copper artefacts. While daunting, this generates more nuanced interpretative frameworks for studying copper provenance and technology.Material Culture Studie

Perfluorocarbon nanodroplets stabilized by fluorinated surfactants: characterization and potentiality as theranostic agents

International audienceWe aim to produce emulsions that can act as contrast agents and drug carriers for cancer imaging and therapy. To increase tumor detection and decrease drug side effects, it is desirable to take advantage of the enhanced permeability and retention effect that allows nanoparticles to accumulate in tumor tissues. To do so, the emulsion droplets need to be small enough and stable over time in addition to enhancing image contrast and carrying a drug payload. In the present study, we have investigated the properties and potentiality as theranostic agents of perfluorocarbon emulsions stabilized by a biocompatible fluorinated surfactant called FTAC. To obtain better control of our system, the synthesis of those surfactants was studied and their physico-chemical properties were explored in different configurations such as micelles, in the perfluorocarbon droplet shell and at water/air and water/perfluorocarbon interfaces. The originality of this work lies in the determination of numerous characteristics of emulsions and fluorinated surfactants including surface tension, interfacial tension, critical micelle concentration, adiabatic compressibility, density, size distribution (aging studies), and ultrasonic echogenicity. These characterization studies were conducted using different types of FTAC and several perfluorocarbons (perfluoropentane, perfluorohexane, and perfluorooctyl bromide). We have also shown that a hydrophobic drug could be encapsulated in the FTAC-stabilized perfluorocarbon droplets thanks to triacetin addition. Finally, the perfluorocarbon emulsions were detectable in vitro by a clinical 3 T MRI scanner, equipped with a double frequency 19F/1H transmit–receive coil

The critical view of safety during laparoscopic cholecystectomy: Strasberg Yes or No? An Italian Multicentre study

Background: Laparoscopic cholecystectomy is considered the gold standard for the treatment of gallbladder lithiasis; nevertheless, the incidence of bile duct injuries (BDI) is still high (0.3–0.8%) compared to open cholecystectomy (0.2%). In 1995, Strasberg introduced the "Critical View of Safety" (CVS) to reduce the risk of BDI. Despite its widespread use, the scientific evidence supporting this technique to prevent BDI is controversial. Methods: Between March 2017 and March 2019, the data of patients submitted to laparoscopic cholecystectomy in 30 Italian surgical departments were collected on a national database. A survey was submitted to all members of Italian Digestive Pathology Society to obtain data on the preoperative workup, the surgical and postoperative management of patients and to judge, at the end of the procedure, if the isolation of the elements was performed according to the CVS. In the case of a declared critical view, iconographic documentation was obtained, finally reviewed by an external auditor. Results: Data from 604 patients were analysed. The study population was divided into two groups according to the evidence (Group A; n = 11) or absence (Group B; N = 593) of BDI and perioperative bleeding. The non-use of CVS was found in 54.6% of procedures in the Group A, and 25.8% in the Group B, and evaluating the operator-related variables the execution of CVS was associated with a significantly lower incidence of BDI and intraoperative bleeding. Conclusions: The CVS confirmed to be the safest technique to recognize the elements of the Calot triangle and, if correctly performed, it significantly impacted on preventing intraoperative complications. Additional educational programs on the correct application of CVS in clinical practice would be desirable to avoid extreme conditions that may require additional procedures

The critical view of safety during laparoscopic cholecystectomy: Strasberg Yes or No? An Italian Multicentre study

Background: Laparoscopic cholecystectomy is considered the gold standard for the treatment of gallbladder lithiasis; nevertheless, the incidence of bile duct injuries (BDI) is still high (0.3–0.8%) compared to open cholecystectomy (0.2%). In 1995, Strasberg introduced the "Critical View of Safety" (CVS) to reduce the risk of BDI. Despite its widespread use, the scientific evidence supporting this technique to prevent BDI is controversial. Methods: Between March 2017 and March 2019, the data of patients submitted to laparoscopic cholecystectomy in 30 Italian surgical departments were collected on a national database. A survey was submitted to all members of Italian Digestive Pathology Society to obtain data on the preoperative workup, the surgical and postoperative management of patients and to judge, at the end of the procedure, if the isolation of the elements was performed according to the CVS. In the case of a declared critical view, iconographic documentation was obtained, finally reviewed by an external auditor. Results: Data from 604 patients were analysed. The study population was divided into two groups according to the evidence (Group A; n = 11) or absence (Group B; N = 593) of BDI and perioperative bleeding. The non-use of CVS was found in 54.6% of procedures in the Group A, and 25.8% in the Group B, and evaluating the operator-related variables the execution of CVS was associated with a significantly lower incidence of BDI and intraoperative bleeding. Conclusions: The CVS confirmed to be the safest technique to recognize the elements of the Calot triangle and, if correctly performed, it significantly impacted on preventing intraoperative complications. Additional educational programs on the correct application of CVS in clinical practice would be desirable to avoid extreme conditions that may require additional procedures