Highly sensitive alkane odour sensors based on functionalised gold nanoparticles

We deposit dense, ordered, thin films of Au-dodecanethiol core/shell nanoparticles by the Langmuir-Schafer (LS) printing method, and find that their resistance at ambient temperature responds selectively and sensitively to alkane odours. Response is a rapid resistance increase due to swelling, and is strongest for alkane odours where the alkane chain is similar in length to the dodecane shell. For decane odours, we find a response to concentrations as low as 15 ppm, about 600 times below the lower explosive limit. Response is weaker, but still significant, to aromatic odours (e.g. Toluene, Xylene), while potential interferants such as polar and/or hydrogen-bonding odours (e.g. alcohols, ketones, water vapour) are somewhat rejected. Resistance is weakly dependent on temperature, and recovers rapidly and completely to its original value within the error margin of measurement. (C) 2011 Elsevier B.V. All rights reserved

The weekend effect on the provision of Emergency Surgery before and during the COVID-19 pandemic: case–control analysis of a retrospective multicentre database

Introduction: The concept of “weekend effect”, that is, substandard healthcare during weekends, has never been fully demonstrated, and the different outcomes of emergency surgical patients admitted during weekends may be due to different conditions at admission and/or different therapeutic approaches. Aim of this international audit was to identify any change of pattern of emergency surgical admissions and treatments during weekends. Furthermore, we aimed at investigating the impact of the COVID-19 pandemic on the alleged “weekend effect”. Methods: The database of the CovidICE-International Study was interrogated, and 6263 patients were selected for analysis. Non-trauma, 18+ yo patients admitted to 45 emergency surgery units in Europe in the months of March–April 2019 and March–April 2020 were included. Demographic and clinical data were anonymised by the referring centre and centrally collected and analysed with a statistical package. This study was endorsed by the Association of Italian Hospital Surgeons (ACOI) and the World Society of Emergency Surgery (WSES). Results: Three-quarters of patients have been admitted during workdays and only 25.7% during weekends. There was no difference in the distribution of gender, age, ASA class and diagnosis during weekends with respect to workdays. The first wave of the COVID pandemic caused a one-third reduction of emergency surgical admission both during workdays and weekends but did not change the relation between workdays and weekends. The treatment was more often surgical for patients admitted during weekends, with no difference between 2019 and 2020, and procedures were more often performed by open surgery. However, patients admitted during weekends had a threefold increased risk of laparoscopy-to-laparotomy conversion (1% vs. 3.4%). Hospital stay was longer in patients admitted during weekends, but those patients had a lower risk of readmission. There was no difference of the rate of rescue surgery between weekends and workdays. Subgroup analysis revealed that interventional procedures for hot gallbladder were less frequently performed on patients admitted during weekends. Conclusions: Our analysis revealed that demographic and clinical profiles of patients admitted during weekends do not differ significantly from workdays, but the therapeutic strategy may be different probably due to lack of availability of services and skillsets during weekends. The first wave of the COVID-19 pandemic did not impact on this difference

Study of oxygen desorption from TixSn1-xO2 by a fast intermittent temperature-programmed desorption (ITPD) technique

internationa

Sensing of volatile alkanes by metal-oxide semiconductors

Sensing of volatile alkanes via chemoresistive gas sensors has been addressed. Screen-printed films of Au- and Pd-added SnO2 and a solid solution of mixed Sn and Ti oxides have been selected for the purpose. We demonstrate that the films sensitively detect 200 ppm of such gases, a value which is by far lower than their alarm limits. Information about the working mechanism of chemical reactions at surface has been discussed

Metal-oxide solid solutions for light alkane sensing

Sensing of light alkanes via chemoresistive gas sensors has been addressed. Screen-printed films of a solid solution of mixed Sn and Ti oxides have been selected for the purpose. We demonstrate that the films sensitively detect 100ppm of such gases and 500ppm of methane, the two levels being by far lower than the alarm limits for these gases. Information about the working mechanism of chemical reactions on the surface has been discussed under either dry or wet condition

Metal-oxide solid solutions for light alkane sensing

Sensing of light alkanes via chemoresistive gas sensors has been addressed. Screen-printed films of a solid solution of mixed Sn and Ti oxides have been selected for the purpose. We demonstrate that the films sensitively detect 100ppm of such gases and 500ppm of methane, two levels which are by far lower than the alarm limits for these gases. Information about the working mechanism of chemical reactions at surface has been discussed under either dry or wet condition

[Appropriate hospital utilization in emergency surgery: application of the Appropiatness Evaluation Protocol].

The Authors developed and tested a new version of the Appropriateness Evaluation Protocol (AEP) to review 160 clinical records of the Emergency Surgery Department of Policlinico Umberto I-Rome. The modifications to the AEP also allow to evaluate the appropriate ward of hospitalization of acute patients (Surgery, Orthopedics, Head & Neck, Burns). 26 (16%) out 160 admissions failed the AEP criteria; 85 of the remaining admissions were judged appropriate in the Emergency Surgery Department (53% of the whole sample), 14 (9%) in the Head & Neck Department, 10 (6%) in the Orthopedic Department, 25 (16%) not in an Emergency Surgery Department. Only 63% of the appropriate admissions has been judged adequate in the Emergency Surgery Department. The Authors conclude that it is necessary to improve the primary "filter" of the hospitalization (the ambulatory care component of the National Health System). Finally, this version of the AEP was shown to be reliable, an useful tool in the hands of trained physicians

TPD and ITPD study of materials used as chemoresistive gas sensors

none7Temperature-programmed desorption (TPD) and a differential form of it, called intermittent temperature-programmed desorption (ITPD), turned out to be powerful characterising techniques for chemoresistive materials applied to gas sensing. We investigated samples of SnO2, TiO2 and solid solutions of them (TixSn1−xO2). TPD and ITPD experiments were carried out in vacuum, with samples previously treated in pure O2 (100 Torr, 500 °C, 30 min). Amounts of desorbed O2 corresponded for all Ti-containing samples to less than 10% of a compact monolayer of ions O2−. Corresponding values of the apparent activation energy of desorption (Eapp) were calculated directly from the Arrhenius plots for each partial TPD and ranged from about 100 to 330 kJ mol− 1 (1.16 to 3.82 eV).noneD. Puzzovio; M. C. Carotta; A. Cervi; A. El Hachimi; J.P. Joly; F. Gaillard; V. GuidiPuzzovio, Delia; Carotta, Maria Cristina; Cervi, Alan; A., El Hachimi; J. P., Joly; F., Gaillard; Guidi, Vincenz

Defunctioning Ileostomy to Prevent the Anastomotic Leakage in Colorectal Surgery. The State of the Art of the Different Available Types

not availabl