First surveillance and draft genome sequences of circulating mcr-1-carrying, multidrug-resistant Escherichia coli in wastewater in Qatar.

Objective: The global rise of colistin resistance, primarily mediated by the mcr-1 gene, threatens the efficacy of one of the last-resort treatments for multidrug-resistant Gram-negative infections. While mcr genes have been reported in clinical, veterinary and limited environmental samples in Qatar, there is a notable gap in data regarding their presence in wastewater.

Methods: Fifteen composite wastewater samples were collected across multiple rounds in Qatar.

Ecotoxicity and environmental safety assessment of two-dimensional niobium carbides (MXenes).

Two-dimensional (2D) MXenes have gained great interest in water treatment, biomedical, and environmental applications. The antimicrobial activity and cell toxicity of several MXenes including NbCT and NbCT have already been explored. However, potential side effects related to Nb-MXene toxicity, especially on aquatic pneuma, have rarely been studied.

Leveraging wastewater surveillance for managing the spread of SARS-CoV-2 and concerned pathogens during FIFA World Cup Qatar 2022.

Wastewater-based epidemiology (WBE) has been proven effective for the monitoring of infectious disease outbreaks during mass gathering events and for timely public health interventions. As part of Qatar's efforts to monitor and combat the spread of infectious diseases during the FIFA World Cup Qatar 2022™ (FWC'22), wastewater surveillance was used to monitor the spread of SARS-CoV-2, human enterovirus, and poliovirus. The screening covered five major wastewater treatment plants servicing the event locations between October 2022 and January 2023.

Anterolateral advancement pharyngoplasty versus barbed reposition pharyngoplasty in patients with obstructive sleep apnea.

Objectives: To compare functional outcomes and complication rates of anterolateral advancement pharyngoplasty (ALA) versus barbed reposition pharyngoplasty (BRP) in the treatment of obstructive sleep apnea patients with palatal and lateral pharyngeal wall collapse.

Study Design: Prospective study.

Setting: University hospitals.

Marine Bacterial Community Structures of Selected Coastal Seawater and Sediment Sites in Qatar.

Severe environmental conditions can have a diverse impact on marine microorganisms, including bacteria. This can have an inevitable impact on the biofouling of membrane-based desalination plants. In this work, we have utilized indicator bacteria such as total coliform, fecal coliform, and , as well as 16S rRNA sequencing, to investigate the impact of environmental conditions and spatial variations on the diversity of bacterial communities in the coastal waters and sediments from selected sites in Qatar.

Application of human RNase P normalization for the realistic estimation of SARS-CoV-2 viral load in wastewater: A perspective from Qatar wastewater surveillance.

The apparent uncertainty associated with shedding patterns, environmental impacts, and sample processing strategies have greatly influenced the variability of SARS-CoV-2 concentrations in wastewater. This study evaluates the use of a new normalization approach using human RNase P for the logic estimation of SARS-CoV-2 viral load in wastewater. SARS-CoV-2 variants outbreak was monitored during the circulating wave between February and August 2021.

MXene (TiCT)/Cellulose Acetate Mixed-Matrix Membrane Enhances Fouling Resistance and Rejection in the Crossflow Filtration Process.

Obstacles in the membrane-based separation field are mainly related to membrane fouling. This study involved the synthesis and utilization of covalently crosslinked MXene/cellulose acetate mixed matrix membranes with MXene at different concentrations (CCAM-0% to CCAM-12%) for water purification applications. The membranes' water flux, dye, and protein rejection performances were compared using dead-end (DE) and crossflow (CF) filtration.

A critical overview of MXenes adsorption behavior toward heavy metals.

In recent years, tremendous interest has been generated in MXenes as a fast-growing and diversified family of two-dimensional (2D) materials with a wide range of potential uses. MXenes exhibit many unique structural and physicochemical properties that make them particularly attractive as adsorbents for removing heavy metals from aqueous media, including a large surface area, abundant surface terminations, electron-richness, and hydrophilic nature. In light of the adsorption capabilities of MXenes at the ever-increasing rate of expansion, this review investigates the recent computational predictions for the adsorption capabilities of MXenes and the effect of synthesis of different MXene on their remediation behavior toward heavy metals.

Advancements of 2D Materials-Based Membranes.

Our environment desperately needs creative solutions to limit the effect of industrialization's fast rise and, consequently, to remediate vast amounts of harmful by-products and toxic exhausts [...

Efficient Photocatalytic Degradation of Organic Dyes by AgNPs/TiO/TiCT MXene Composites under UV and Solar Light.

Due to their broad applications in various industrial activities, and their well-known negative impacts on the aquatic environment, organic dyes have been continuously identified as serious threat to the quality of ecosystems. The photocatalytic degradation process in aqueous solutions has emerged as an efficient and reliable approach for the removal of organic dyes. MXenes, a new class of two-dimensional (2D) nanomaterials, possess unique chemical composition, surface functionalities, and physicochemical properties.

Enhanced water flux and bacterial resistance in cellulose acetate membranes with quaternary ammoniumpropylated polysilsesquioxane.

An enhanced water flux and anti-fouling nanocomposite ultrafiltration membrane based on quaternary ammoniumpropylated polysilsesquioxane (QAPS)/cellulose acetate (QAPS@CA) was fabricated by in situ sol-gel processing via phase inversion followed by quaternization with methyl iodide (CHI). Membrane characterizations were performed based on the contact angle, FTIR, SEM, and TGA properties. Membrane separation performance was assessed in terms of pure water flux, rejection, and fouling resistance.

Antibacterial Mechanism of Multifunctional MXene Nanosheets: Domain Formation and Phase Transition in Lipid Bilayer.

MXenes, two-dimensional metal carbides or nitrides with multifunctional surfaces, are one of the most promising antibacterial nanoscale materials. However, their putative bactericidal mechanism is elusive. To study their bactericidal mechanism, we investigated the interaction between a MXene nanosheet and a model bacterial membrane by molecular dynamics simulations and found that an adsorbed MXene on a membrane surface induced a local phase transition in a domain where the fluidity of the phospholipid in this domain at room temperature was comparable with that of the gel phase.

First-Principles Density Functional Theory Calculations of Bilayer Membranes Heterostructures of TiCT (MXene)/Graphene and AgNPs.

The properties of two-dimensional (2D) layered membrane systems can be medullated by the stacking arrangement and the heterostructure composition of the membrane. This largely affects the performance and stability of such membranes. Here, we have used first-principle density functional theory calculations to conduct a comparative study of two heterostructural bilayer systems of the 2D-MXene (TiCT, T = F, O, and OH) sheets with graphene and silver nanoparticles (AgNPs).

COVID-19 (SARS-CoV-2) outbreak monitoring using wastewater-based epidemiology in Qatar.

Raw municipal wastewater from five wastewater treatment plants representing the vast majority of the Qatar population was sampled between the third week of June 2020 and the end of August 2020, during the period of declining cases after the peak of the first wave of infection in May 2020. The N1 region of the SARS-CoV-2 genome was used to quantify the viral load in the wastewater using RT-qPCR. The trend in Ct values in the wastewater samples mirrored the number of new daily positive cases officially reported for the country, confirmed by RT-qPCR testing of naso-pharyngeal swabs.

"Safe" Chitosan/Zinc Oxide Nanocomposite Has Minimal Organ-Specific Toxicity in Early Stages of Zebrafish Development.

Marine biofouling is considered to be one of the most challenging issues affecting maritime industries worldwide. In this regard, traditional biocides, being used to combat biofouling, have high toxicity toward aquatic systems. Recently, a new chitosan/zinc oxide nanoparticle (CZNC) composite has been used as a promising "green" biocide.

Unprecedented environmental and energy impacts and challenges of COVID-19 pandemic.

The rapid transmission tendency, severity, and wide geographical spread of newly emerged novel coronavirus (SARS-CoV-2) in different environmental matrices, including water, air, and soil, has posed severe health, environmental, energy, and economic challenges worldwide. Despite the severe health effects, unprecedented improvements in air quality in many countries due to emergency measures, and public behavior changes have been reported. SARS-CoV-2 has been detected in air and sewage samples in several studies across the globe.

Large interlayer spacing NbCT (MXene) promotes the ultrasensitive electrochemical detection of Pb on glassy carbon electrodes.

A NbCT (MXene)-modified glassy carbon electrode was used for the electrochemical detection of Pb ions in aqueous media. The sensing platform was evaluated by anodic stripping analysis after optimizing the influencing factors such as pH, deposition potential, and time. The large interlayer spacing, high lattice parameter and higher conductivity of NbCT compared to other MXenes enhance the electrochemical detection of Pb.

Chitosan/Lignosulfonate Nanospheres as "Green" Biocide for Controlling the Microbiologically Influenced Corrosion of Carbon Steel.

In this work, uniform cross-linked chitosan/lignosulfonate (CS/LS) nanospheres with an average diameter of 150-200 nm have been successfully used as a novel, environmentally friendly biocide for the inhibition of mixed sulfate-reducing bacteria (SRB) culture, thereby controlling microbiologically influenced corrosion (MIC) on carbon steel. It was found that 500 µg·mL of the CS/LS nanospheres can be used efficiently for the inhibition of SRB-induced corrosion up to a maximum of 85% indicated by a two fold increase of charge transfer resistance () on the carbon steel coupons. The hydrophilic surface of CS/LS can readily bind to the negatively charged bacterial surfaces and thereby leads to the inactivation or damage of bacterial cells.

Natural clay-supported palladium catalysts for methane oxidation reaction: effect of alloying.

The catalytic combustion of methane (CCM) has been extensively studied owing to the wide use of methane in motor vehicles and power generation turbines. However, the absence of polarizability and the high C-H bond strength are considered to be the main drawbacks that limit its oxidation by traditional catalytic converters. Palladium-based catalysts are recognized as the benchmark catalysts for methane oxidation, especially under oxidizing conditions, and their activity is dependent on different parameters such as size, dispersion, and the nature of the support.

Plasmonic MXene-based nanocomposites exhibiting photothermal therapeutic effects with lower acute toxicity than pure MXene.

Here, we fabricated two plasmonic 2D TiCT-based nanocomposites (Au/MXene and Au/FeO/MXene) with similarly high anti-cancer photothermal therapy (PTT) capabilities, but with less in vivo toxicity than a pure MXene. Au/MXene was synthesized by in situ reduction of tetrachloroauric acid using NaBH on TiCT flakes. For targeted PTT, magnetic Au/FeO/MXene was synthesized via a reaction between freshly prepared magnetite FeO NPs and MXene solution, followed by in situ integration of gold nanoparticles (AuNPs).

A flexible TiCT (MXene)/paper membrane for efficient oil/water separation.

The scalable fabrication of flexible membranes for efficient oil/water separation is in high demand but still significantly underdeveloped. Here, we present a flexible membrane using TiCT (MXene) as the functional layer on conventional print paper as the substrate. With a simple coating process using MXene ink, we developed a highly hydrophilic and oleophobic membrane with an underwater oil contact angle of 137°.

Impaired Liver Size and Compromised Neurobehavioral Activity are Elicited by Chitosan Nanoparticles in the Zebrafish Embryo Model.

The use of chitosan nanoparticles (ChNPs) in various biological and environmental applications is attracting great interest. However, potential side effects related to ChNP toxicity remain the major limitation hampering their wide application. For the first time, we investigate the potential organ-specific (cardiac, hepatic, and neuromuscular) toxicity of ChNPs (size 100⁻150 nm) using the zebrafish embryo model.

Effect of Synthesis on Performance of MXene/Iron Oxide Anode Material for Lithium-Ion Batteries.

Two-dimensional heterostructures, such as FeO/MXene nanoparticles, can be attractive anode materials for lithium-ion batteries (LIBs) due to the synergy between high lithium-storage capacity of FeO and stable cyclability and high conductivity provided by MXene. Here, we improved the storage performance of TiCT (MXene)/FeO nanocomposite by confining FeO nanoparticles into TiCT nanosheets with different mixing ratios using a facile and scalable dry ball-milling process. Composites of TiCT -25 wt % FeO and TiCT -50 wt % FeO synthesized by ball-milling resulted in uniform distribution of FeO nanoparticles on TiCT nanosheets with minimum oxidation of MXene as compared to composites prepared by hydrothermal or wet sonication.

Graphene nanoplatelet doping of P3HT:PCBM photoactive layer of bulk heterojunction organic solar cells for enhancing performance.

Hybrid organic photovoltaic (OPV) cells based on conjugated polymer photoactive materials are promising candidates for flexible, high-performance and low-cost energy sources owing to their inexpensive materials, cost-effective processing and ease of fabrication by simple solution processes. However, the modest PV performance obtained to date-in particular the low power conversion efficiency (PCE)-has impeded the large scale deployment of OPV cells. The low PCE in OPV solar cells is mainly attributed to the low carrier mobility, which is closely correlated to the transport diffusion length of the charge carriers within the photoactive layers.

Mercuric ion capturing by recoverable titanium carbide magnetic nanocomposite.

Two-dimensional metal carbides and nitrides (MXenes) have attracted increasing attention for application in water/wastewater treatment. The functionalization of MXenes to increase their stability while demonstrating high pollutant removal can facilitate sustainable water/wastewater treatment processes. In this study, the highly stable magnetic titanium carbide (TiCT) MXene nanocomposite (MGMX nanocomposite) was successfully synthesized through a facile hydrothermal approach and was tested for aqueous-phase adsorptive removal of mercuric ions.