Acute and chronic toxicity of cationic polyquaterniums of varying charge density and molecular weight to Daphnia magna and Ceriodaphnia dubia.

Cationic polymers have the unique ability to neutralize negative charge with practical applications in personal care products, such as shampoos, conditioners, contact lens solutions, and as flocculants in wastewater treatment processes. Cationic polymers are a diverse class of materials varying in structural composition, cationic charge density (CD), and molecular weight (MW). In this study, we investigated three classes of polyquaternium cationic polymers (PQ-6, PQ-10, PQ-16) of varying CD and MW to characterize their toxicity to aquatic invertebrates.

Reversible formation of tetraphenylpentalene, a room temperature stable antiaromatic hydrocarbon.

1,3,4,6-Tetraphenylpentalene (PhPn) has been synthesised by chemical oxidation of the corresponding pentalenide complex Mg[PhPn] with iodine. PhPn is a rare example of a room-temperature stable hydrocarbon that is antiaromatic by Hückel's rule and has been fully characterised by NMR and UV-vis spectroscopy, mass spectrometry as well as single-crystal X-ray diffraction. Quantum chemical studies including nucleus-independent chemical shift (NICS) and anisotropy of the induced current density (ACID) calculations showed the existence of an 8π antiaromatic core decorated with four independent 6π aromatic substituents.

Plaseval: a framework for comparing and evaluating plasmid detection tools.

Background: Plasmids play a major role in the transfer of antimicrobial resistance (AMR) genes among bacteria via horizontal gene transfer. The identification of plasmids in short-read assemblies is a challenging problem and a very active research area. Plasmid binning aims at detecting, in a draft genome assembly, groups (bins) of contigs likely to originate from the same plasmid.

Microbiological analysis of tunneled hemodialysis catheters isolated from patients receiving hemodialysis in Saskatchewan.

To compare the microbial communities inside hemodialysis catheters from symptomatic and asymptomatic patients to determine their differences. Catheters ( = 41) were removed from patients in the Saskatchewan Health Authority over an 18-month period. The catheter section inside the body was flushed and the contents were evaluated using culture-dependent and culture-independent analysis.

Understanding and tuning the electronic structure of pentalenides.

Here we report the first example of systematic tuning of the electronic properties of dianionic pentalenides through a straightforward synthetic protocol which allows the controlled variation of substituents in the 1,3,4,6-positions to produce nine new compounds, representing the largest pentalenide study to date. Both electron-withdrawing as well as electron-donating aromatics have been incorporated to achieve different polarisations of the bicyclic 10π aromatic core as indicated by characteristic H and C NMR shifts and evaluated by DFT calculations including nucleus-independent chemical shift (NICS) scans, anisotropy of the induced current density (ACID) calculations, and natural bond orbital (NBO) charge distribution analysis. The introduction of methyl substituents to the pentalenide core required positional control in the dihydropentalene precursor to avoid exocyclic deprotonation during the metalation.

Methods for Genomic Epidemiology of Bacterial Pathogens: Example Salmonella.

Genomics has revolutionized how we characterize and monitor infectious diseases for public health. The surveillance and characterization of Salmonella has improved drastically within the past decade. In this chapter, we discuss the prerequisites for good bacterial genomics studies and make note of advantages and disadvantages of this research approach.

Collaborative approaches to greenhouse gas inventory in higher education: Insights from the Universities Denmark Group.

The challenges faced by universities and private industry in estimating their emissions for decarbonisation are similar, but the task of linking emissions to university operations, namely procurement, is complex and time-consuming due to the wide range and types of purchases. Here, participatory action research is used to address these challenges, with a group of Danish universities to investigate the functions and improve the completeness of university GHG inventories. The research enabled knowledge sharing and collaboration, leading to a better understanding of the complexities and possibilities of GHG inventories.

Twinned linked organometallics - bimetallic "half-baguette" pentalenide complexes of Rh(I).

The application of and in transmetalation reactions to a range of Rh(I) precursors led to the formation of "half-baguette" (L = 1,5-cyclooctadiene, norbornadiene, ethylene; = 1, 2) and complexes as well as the related iridium complex . With CO exclusive metalation was obtained even when using mono-nuclear Rh(I) precursors, indicating an electronic preference for metalation. DFT analysis showed this to be the result of π overlap between the adjacent M(CO) units which overcompensates for d repulsion of the metals, an effect which can be overridden by steric clash of the auxiliary ligands to yield -configuration as seen in the larger olefin complexes.

Identification of plasmids in avian-associated Escherichia coli using nanopore and illumina sequencing.

Background: Avian pathogenic Escherichia coli (APEC) are the causative agents of colibacillosis in chickens, a disease which has significant economic impact on the poultry industry. Large plasmids detected in APEC are known to contribute to strain diversity for pathogenicity and antimicrobial resistance, but there could be other plasmids that are missed in standard analysis. In this study, we determined the impact of sequencing and assembly factors for the detection of plasmids in an E.

Environmental impact of the explosion of the Nord Stream pipelines.

Armed conflicts have, in addition to severe impacts on human lives and infrastructure, also impacts on the environment, which needs to be assessed and documented. On September the 26th 2022, unknown perpetrators deliberately ruptured the two gas pipelines Nord Stream 1 and 2 with four coordinated explosions near a major chemical munition dump site near the Danish island of Bornholm in the Baltic Sea. While the massive release of natural gas into atmosphere raised serious concerns concerning the contribution to climate change-this paper assesses the overlooked direct impact of the explosions on the marine ecosystem.

Suspect and non-target screening of semi-volatile emerging contaminants in indoor dust from Danish kindergartens.

Indoor dust is a sink of hundreds of organic chemicals, and humans may potentially be exposed to these via indoor activities. This study investigated potentially harmful semi-volatile organic contaminants in indoor dust from Danish kindergartens using suspect and non-target screening on gas chromatography (GC)-Orbitrap, supported by target analyses using GC-low resolution mass spectrometry (LRMS). A suspect list of 41 chemicals with one or more toxicological endpoints, i.

Synthesis, Structure, and Reactivity of Magnesium Pentalenides.

The first magnesium pentalenide complexes have been synthesized deprotonative metalation of 1,3,4,6-tetraphenyldihydropentalene () with magnesium alkyls. Both the nature of the metalating agent and the reaction solvent influenced the structure of the resulting complexes, and an equilibrium between and was found to exist and investigated by NMR, XRD, and UV-vis spectroscopic techniques. Studies on the reactivity of with water, methyl iodide, and trimethylsilylchloride revealed that the unit undergoes electrophilic addition at 1,5-positions instead of 1,4-positions known for the unsubstituted pentalenide, , highlighting the electronic influence of the four aryl substituents on the pentalenide core.

Acute toxicity of organoarsenic chemical warfare agents to Danio rerio embryos.

During the 20th century, thousands of tons of munitions containing organoarsenic chemical warfare agents (CWAs) were dumped into oceans, seas and inland waters around the world. As a result, organoarsenic CWAs continue to leak from corroding munitions into sediments and their environmental concentrations are expected to peak over the next few decades. There remains, however, a lack of knowledge about their potential toxicity to aquatic vertebrates, such as fish.

Hybrid Genome Assemblies of 245 Avian and Broiler Barn Environment-Associated Escherichia coli Strains Isolated from Saskatchewan Broiler Farms.

Escherichia coli infections in poultry cause significant morbidity and economic losses for producers each year. In a 3-year period, we collected and sequenced the whole genomes of E. coli disease isolates ( = 91), isolates from presumed healthy birds ( = 61), and isolates from 8 barn sites ( = 93) on broiler farms in Saskatchewan.

Exploring the mobilome and resistome of in a One Health context across two continents.

is a ubiquitous opportunistic pathogen that is exhibiting increasing levels of antimicrobial resistance (AMR). Many of the genes that confer resistance and pathogenic functions are localized on mobile genetic elements (MGEs), which facilitate their transfer between lineages. Here, features including resistance determinants, virulence factors and MGEs were profiled in a set of 1273 genomes from two disparate geographic locations (in the UK and Canada) from a range of agricultural, clinical and associated habitats.

Understanding Ecotoxicological Responses of Fish Embryos and Gill Cells to Cationic Polymers.

Cationic polymers are considered by the scientific and regulatory communities as a group of greater interest amongst the polymers in commerce. As a category, relatively little hazard information is available in the public literature. Very few examples exist of published, high-quality polymer characterization and quantification of exposure.

Environmental hazard of cationic polymers relevant in personal and consumer care products: A critical review.

Historically, polymers have been excluded from registration and evaluation under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) program, the European chemical management program. Recently, interest has increased to include polymers. A tiered registration system has been envisioned and would begin with classes of polymers of greater interest based on certain properties.

Green Chemistry in the Synthesis of Pharmaceuticals.

The principles of green chemistry (GC) can be comprehensively implemented in green synthesis of pharmaceuticals by choosing no solvents or green solvents (preferably water), alternative reaction media, and consideration of one-pot synthesis, multicomponent reactions (MCRs), continuous processing, and process intensification approaches for atom economy and final waste reduction. The GC's execution in green synthesis can be performed using a holistic design of the active pharmaceutical ingredient's (API) life cycle, minimizing hazards and pollution, and capitalizing the resource efficiency in the synthesis technique. Thus, the presented review accounts for the comprehensive exploration of GC's principles and metrics, an appropriate implication of those ideas in each step of the reaction schemes, from raw material to an intermediate to the final product's synthesis, and the final execution of the synthesis into scalable industry-based production.

Investigation of long-term hazards of chemical weapon agents in the environment of Sardasht area, Iran.

The present study aimed to investigate the persistence and existence of chemical warfare agents (CWAs) and related dissipation products in the environment of Sardasht area, Iran. Three types of environmental samples including water, soil, and native local plant materials were collected and analyzed. Gas chromatography-mass spectrometry in the electron impact ionization mode has been developed for the separation, screening, identification, and qualification of chemicals after the sample preparation methods.

Evolution of mouse circadian enhancers from transposable elements.

Background: Transposable elements are increasingly recognized as a source of cis-regulatory variation. Previous studies have revealed that transposons are often bound by transcription factors and some have been co-opted into functional enhancers regulating host gene expression. However, the process by which transposons mature into complex regulatory elements, like enhancers, remains poorly understood.

Acute aquatic toxicity of arsenic-based chemical warfare agents to Daphnia magna.

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems.

Fatal infection in a domestic kitten.

has not been reported to cause disease in domestic cats, to our knowledge. In contrast, infection is common in domestic cats and typically results in conjunctivitis, upper respiratory tract infection, and less frequently pneumonia. Herein, we report the pathologic findings and diagnostic features of a fatal case of psittacosis in a 7-wk-old domestic kitten.