Effectiveness and safety of a simple catheter securement device aimed at preventing catheter-associated urinary tract infection in intensive care unit patients: A randomized controlled trial.

BACKGROUND: Clinical practice guidelines for the prevention of catheter associated urinary tract infection (CAUTI) recommend urinary catheter securement in critical patients although there is scant research on its effectiveness. AIM: To analyse whether securement of an indwelling urinary catheter (IUC) reduces the risk of CAUTI and meatal pressure injury among intensive care unit (ICU) patients and assess medical adhesive-related skin injury (MARSI) associated with the securement device. STUDY DESIGN: Open randomized controlled trial involving patients admitted to two ICUs in Spain. In the intervention group (n = 169 patients), the IUC was secured to the thigh using an in-house device piloted as part of this trial. Controls (n = 181) received standard care, including non-securement of the IUC. Barrier film spray was applied to the securement site with the aim of preventing MARSI. The definitions of the main outcomes were: CAUTI was diagnosed according to the criteria of the European Centre for Disease Prevention and Control, meatal pressure injury was categorized into four grades and MARSI was classified as either erythema or skin tears. Bivariate analysis and multivariate logistic regression were performed. Log-rank and Cox regressions were used to compare risk over time to CAUTI and meatal pressure injury in the two groups. RESULTS: Data from 350 patients were analysed, 169 (48.29%) from IG and 181 (51.71%) from CG. In the multiple logistic regression analysis, IUC securement was an independent protective factor against both CAUTI (RR = 0.2, 95% CI [0.05, 0.67]) and meatal pressure injury (RR = 0.31, 95% CI [0.15, 0.58]). The incidence of MARSI was 7.1%. CONCLUSION: Effective IUC securement significantly reduces the risk of CAUTI and meatal pressure injury among ICU patients. The in-house device piloted in the present trial is simple for nurses to use, and the incidence of MARSI was low. These results underline the benefits of IUC securement. RELEVANCE TO CLINICAL PRACTICE: Indwelling urinary catheter (IUC) securement reduces the risk of urinary tract infection. IUC securement helps prevent meatal pressure injury. IUC securement with in-house devices is safe and effective.

Superstructure of a substituted zeolitic imidazolate metal-organic framework determined by combining proton solid-state NMR spectroscopy and DFT calculations.

We report the supercell crystal structure of a ZIF-8 analog substituted imidazolate metal-organic framework (SIM-1) obtained by combining solid-state nuclear magnetic resonance and powder X-ray diffraction experiments with density functional theory calculations.

MOF-supported selective ethylene dimerization single-site catalysts through one-pot postsynthetic modification.

The one-pot postfunctionalization allows anchoring a molecular nickel complex into a mesoporous metal-organic framework (Ni@(Fe)MIL-101). It is generating a very active and reusable catalyst for the liquid-phase ethylene dimerization to selectively form 1-butene. Higher selectivity for 1-butene is found using the Ni@(Fe)MIL-101 catalyst than reported for molecular nickel diimino complexes.

Absolute molecular sieve separation of ethylene/ethane mixtures with silver zeolite A.

Absolute ethylene/ethane separation is achieved by ethane exclusion on silver-exchanged zeolite A adsorbent. This molecular sieving type separation is attributed to the pore size of the adsorbent, which falls between ethylene and ethane kinetic diameters.

Metal-organic frameworks: opportunities for catalysis.

The role of metal-organic frameworks (MOFs) in the field of catalysis is discussed, and special focus is placed on their assets and limits in light of current challenges in catalysis and green chemistry. Their structural and dynamic features are presented in terms of catalytic functions along with how MOFs can be designed to bridge the gap between zeolites and enzymes. The contributions of MOFs to the field of catalysis are comprehensively reviewed and a list of catalytic candidates is given. The subject is presented from a multidisciplinary point of view covering solid-state chemistry, materials science, and catalysis.

An Ag-loaded photoactive nano-metal organic framework as a promising biofilm treatment.

Surface biofilm inhibition is still currently a considerable challenge. Among other organisms, Staphylococcus aureus is notable for its ability to form a strong biofilm with proved resistance to chemotherapy. Contamination of high-touch surfaces with S. aureus biofilm not only promotes disease spread but also generates tremendous health-associated costs. Therefore, development of new bactericidal and antiadhesive surface coatings is a priority. Considering that metal-organic frameworks (MOFs) have recently emerged as promising antibacterial agents, we originally report here the synthesis of a multi-active silver-containing nanoscaled MOF composite as a potential surface coating against S. aureus biofilm owing to a triple effect: intrinsic bactericide activity of the MOF, biocidal character of silver nanoparticles (AgNPs), and photoactivity after UVA irradiation. AgNPs were successfully entrapped within the benchmarked nanoscaled porous photoactive titanium(IV) aminoterephthalate MIL-125(Ti)NH2 using a simple and efficient impregnation-reduction method. After complete characterization of the composite thin film, its antibacterial and anti-adherent properties were fully evaluated. After UVA irradiation, the composite coating exhibited relevant bacterial inhibition and detachment, improved ligand-to-cluster charge transfer, and steady controlled delivery of Ag+. These promising results establish the potential of this composite as an active coating for biofilm treatment on high-touch surfaces (e.g., surgical devices, door knobs, and rail bars). STATEMENT OF SIGNIFICANCE: Surface contamination due to bacterial biofilm formation is still a demanding issue, as it causes severe disease spread. One possible solution is the development of antifouling and antibacterial surface coatings. In this work, we originally propose the use of photoactive metal-organic frameworks (MOFs) for biofilm treatment. The novelty of this work relies on the following: i) the treatment of strongly contaminated surfaces, as previous studies with MOFs have exclusively addressed biofilm prevention; ii) this pioneering work reports both antiadherent effect, which removes the biofilm, and bacterial inhibition; iii) our original successful strategy has never been proposed thus far, involving the multi-active combination of 1) intrinsic antibacterial effect of a photoactive titanium-based nanoMOF, 2) immobilization of biocide silver nanoparticles, and 3) improved anti-bioadherent effect upon irradiation of the composite coating.

Recycling of end-of-life reverse osmosis membranes for membrane biofilms reactors (MBfRs). Effect of chlorination on the membrane surface and gas permeability.

Reducing human impacts on drinking water is one of the main challenges for the water treatment industry. This work provides new results to support the recycling of EoL desalination reverse osmosis (RO) membranes for Membranes Biofilm Reactors (MBfRs). We investigate if the controlled-removal of fouling and polyamide layer may favor the use of these membranes in MBfRs. It also would allow establishing a normalized methodology of membrane recycling, regardless of inherited fouling during its lifespan. For this purpose, we transform by chlorination discarded brackish (BWd) and seawater (SWd) membranes into nanofiltration (BWt-NF and SWt-NF) and ultrafiltration (BWt-UF and SWt-UF) membranes. Our results show that chlorine attacks allow the fouling cleaning while improves the hydrophilicity and maintains roughness only in BWt-NF. Therefore, the bacterial deposition in this membrane is greater than the other tested membranes. Besides, the microcystin (MC) degradation capacity of BWt-NF verifies the compatibility of the chemical modification for the biological activity of MC-degrading bacteria. Finally, our results also provide that polyamide thin-film composite (PA-TFC) membranes, originally manufactured for salt rejection during desalination processes, offer competitive gases diffusion at low pressures. Therefore, we conclude that the membrane recycling may provide alternative low cost and gas permeable membranes for MBfRs, according to circular economy principles.

Co, Zn and Ag-MOFs evaluation as biocidal materials towards photosynthetic organisms.

In the present study, the biocidal activity of three different metal organic frameworks (MOFs) based on Co (Co-SIM1), Zn (Zn-SIM1) and Ag (Ag-TAZ) has been evaluated towards one green alga and two cyanobacteria. These organisms are present in fresh- and seawater and take part in the early stages of the biofouling process. The biocidal activity of these materials was evaluated by measuring chlorophyll a concentration and by inhibition zone testing. After 24h of exposure the three different MOFs caused >50% of chlorophyll a concentration inhibition towards both cyanobacteria, however, although the green alga presented a great sensitivity for Ag-TAZ (reaching 90% of chlorophyll a concentration inhibition), it was much more resistant to the rest of MOFs. Bioavailability of these metals was studied using ICP-MS, the chemical speciation program Visual MINTEQ, and a heavy metal bioreporter bioanalytical tool. We have elucidated that the biocidal activity presented by these MOFs was due to the dissolved metals released from them and more exactly, it depended on the bioavailability presented by these metal ions, which was closely related with the free ion concentration. This article highlights the potential use of different MOFs as biocidal material towards photosynthetic organisms and reveals important differences in the sensitivity between these organisms that should be taken into account in order to increase the biocidal spectrum of these materials.

A Pt/Al2O3-supported metal-organic framework film as the size-selective core-shell hydrogenation catalyst.

The substituted imidazolate-based MOF (SIM-1) easily forms a homogeneous layer at the surface of millimetric platinum-loaded alumina beads. This new core-shell SIM-1@Pt/Al2O3 catalyst shows the fine molecular sieving effect for the Pt-catalyzed hydrogenation of carbon-carbon double bonds.

Antimicrobial activity of cobalt imidazolate metal-organic frameworks.

Two cobalt imidazolate metal-organic frameworks were evaluated as a bactericidal material against the growth of the Gram-negative bacteria Pseudomonas putida and Escherichia coli. Under the most unfavourable conditions, within the exponential growth phase and in the culture media for both microorganisms, the growth inhibition reached over 50% for concentrations of biocidal material in the 5-10mgL(-1) range. The release of metal gives excellent durability with the antibacterial effect persisting after 3months. Both cobalt-based materials can be prepared with simple, cheap and easily accessible commercial ligands, leading to a more affordable possible future application as antimicrobial materials.

Combinatorial synthesis and characterization of metal-open frameworks in mild and friendly conditions: application to CO2 adsorption.

Combinatorial screening using precipitation methods at room temperature can lead to a great diversity of carboxylate based Metal Organic Frameworks (MOFs) including already known or original porous solids. The investigation of the synthesis of MOFs in different solvent and solvent mixtures includes the use of solvents such as alcohols and tetrahydrofuran (THF) which would greatly facilitate large scale production. We also show the application of Principal Component Analysis (PCA) and clustering techniques on large libraries of XRD diffraction files in order to identify classes of similar phases and peculiar phases. The combinatorial screening of 105 samples in the La/btc system has led to the identification of two phases which are solvent depending. On the La(btc) compound, the CO2 adsorption measurements reveal a guest-host interactions as supported by XRD phase transformation upon thermal treatment. The mass transport can be assigned to a "single file diffusion" regime due to the one dimensional channel porous structure associated to small pore size.

Amino acid functionalized metal-organic frameworks by a soft coupling-deprotection sequence.

Covalent post-synthetic modification of a MOF, (In) MIL-68-NH(2), is carried out in a novel fashion to immobilize amino acids within the structure. Solid-phase peptide coupling methodology opens new perspectives for anchoring chiral bio- and catalytically active species. This could facilitate the immobilization of highly active and/or coordinating moieties inside MOF cavities.

Facile shaping of an imidazolate-based MOF on ceramic beads for adsorption and catalytic applications.

A substituted imidazolate-based MOF (SIM-1), easily shaped in situ on and in millimetre-sized alumina beads, is useful for catalytic applications and undergoes no modification of its intrinsic properties.