Search

Objective: To describe the epidemiology of healthcare-associated Clostridioides difficile infection (HA-CDI) in two Québec hospitals in Canada following the 2003 epidemic and to evaluate the impact of antibiotic stewardship on the incidence of HA-CDI and the NAP1/027 strain., Design: Time-series analysis., Setting: Two Canadian tertiary care hospitals based in Montréal, Québec., Patients: Patients with a positive assay for toxigenic C. difficile were identified through infection control surveillance. All cases of HA-CDI, defined as symptoms occurring after 72 hours of hospital admission or within 4 weeks of hospitalization, were included., Methods: The incidence of HA-CDI and antibiotic utilization from 2003 to 2020 were analyzed with available C. difficile isolates. The impact of antibiotic utilization on HA-CDI incidence was estimated by a dynamic regression time-series model. Antibiotic utilization and the proportion of NAP1/027 strains were compared biannually for available isolates from 2010 to 2020., Results: The incidence of HA-CDI decreased between 2003 and 2020 at both hospitals from 26.5 cases per 10,000 patient-days in 2003 to 4.9 cases per 10,000 patient-days in 2020 respectively. Over the study period, there were an increase in the utilization of third-generation cephalosporins and a decrease in usage of fluoroquinolones and clindamycin. A decrease in fluoroquinolone utilization was associated with a significant decrease in HA-CDI incidence as well as decrease in the NAP1/027 strain by approximately 80% in both hospitals., Conclusions: Decreased utilization of fluoroquinolones in two Québec hospitals was associated with a decrease in the incidence of HA-CDI and a genotype shift from NAP1/027 to non-NAP1/027 strains., Competing Interests: YL received salary support from the Fonds de Recherche du Québec outside of this work. VGL received consulting fees from Ferring Inc., Merck Inc., and Xediton Pharmaceuticals Inc. outside of this work. All other authors report no competing interests., (© The Author(s) 2024.)

Urban mining of precious metals from electronic waste, such as printed circuit boards (PCB), is not yet feasible because of the lengthy isolation process, health risks, and environmental impact. Although porous polymers are particularly effective toward the capture of metal contaminants, those with porphyrin linkers have not yet been considered for precious metal recovery, despite their potential. Here, we report a porous porphyrin polymer that captures precious metals quantitatively from PCB leachate even in the presence of 63 elements from the Periodic Table. The nanoporous polymer is synthesized in two steps from widely available monomers without the need for costly catalysts and can be scaled up without loss of activity. Through a reductive capture mechanism, gold is recovered with 10 times the theoretical limit, reaching a record 1.62 g/g. With 99% uptake taking place in the first 30 min, the metal adsorbed to the porous polymer can be desorbed rapidly and reused for repetitive batches. Density functional theory (DFT) calculations indicate that energetically favorable multinuclear-Au binding enhances adsorption as clusters, leading to rapid capture, while Pt capture remains predominantly at single porphyrin sites., Competing Interests: Competing interest statement: KAIST has filed provisional patent applications (KR: 10-2017-0170184, 10-2018-0129227; PCT: PCT/KR2018/013067; US: 16212052; JP: 2018-230885) related to the materials and precious metal recovery reported in this article. J.F.S. and J.L.S. are subcontractors on an NSF CCI grant.

Rigid network structures of nanoporous organic polymers provide high porosity, which is beneficial for applications such as gas sorption, gas separation, heterogeneous (photo)catalysis, sensing, and (opto)electronics. However, the network structures are practically insoluble. Thus, the processing of nanoporous polymers into nanoparticles or films remains challenging. Herein, we report that nanoporous polymers made via a Knoevenagel-like condensation can be easily processed into nanoparticles (115.7 ± 40.8 nm) or a flawless film by using liquid amines as a solvent at elevated temperatures. FTIR spectra revealed that the carboxyl groups in the nanoporous polymers act as reactive sites for amines, forming new functionalities and spacing the polymeric chains to be dissolved in the liquid amines. The processed film was found to be CO 2 -philic despite the low surface area, and further able to be transformed into a fine carbon film by thermal treatment., (Copyright © 2019, Byun et al.; licensee Beilstein-Institut.)

Molecular architecture in nanoscale spaces can lead to selective chemical interactions and separation of species with similar sizes and functionality. Substrate specific sorbent chemistry is well known through highly crystalline ordered structures such as zeolites, metal organic frameworks and widely available nanoporous carbons. Size and charge-dependent separation of aqueous molecular contaminants, on the contrary, have not been adequately developed. Here we report a charge-specific size-dependent separation of water-soluble molecules through an ultra-microporous polymeric network that features fluorines as the predominant surface functional groups. Treatment of similarly sized organic molecules with and without charges shows that fluorine interacts with charges favourably. Control experiments using similarly constructed frameworks with or without fluorines verify the fluorine-cation interactions. Lack of a σ-hole for fluorine atoms is suggested to be responsible for this distinct property, and future applications of this discovery, such as desalination and mixed matrix membranes, may be expected to follow.

Effective carbon dioxide (CO 2 ) capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon-carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile-aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m 2 /g) and easily interchangeable nitrile groups, was modified post-synthetically into free amine- or amidoxime-containing networks. The modified COP-156-amine showed fast and increased CO 2 uptake under simulated moist flue gas conditions compared to the starting network and usual industrial CO 2 solvents, reaching up to 7.8 wt % uptake at 40 °C.

3π-2spiro compounds are constituted of three π-systems linked through two shared spiro carbons leading to a three-dimensional architecture. The modulation of the electronic properties of such molecular systems can be achieved through the modification and/or substitution of their different π-systems and by the modification of their geometry. The present work is focused on the tuning of the electrochemical properties of a wide range of 3π-2spiro compounds based on fluorenyl, xanthenyl, 2,7-disubstituted fluorenyl, 1,2-b- or 2,1-a-indenofluorenyl, and pentaphenylenyl fragments with a main emphasis on the localization of the successive electron transfers. A detailed structure-property relationship study of interest for the organic electronics scientific community is then drawn.