An Inexpensive Adaptation of a Commercial Microwave Reactor for Solid Phase Peptide Synthesis.

A home-built apparatus to perform solid phase peptide synthesis (SPPS), assisted by microwave irradiation and heating, is presented. In contrast to conventional SPPS reaction vessels, which drain solvent and byproducts via a frit located at the bottom of the vessel, the presented apparatus employs a gas dispersion tube under vacuum to remove solvent, byproducts, and excess reagents. The same gas dispersion tube supplies nitrogen gas agitation of the SPPS beads during the reaction steps of coupling and deprotection.

Developmental effects of zebrafish (Danio rerio) embryos after exposure to glyphosate and lead mixtures.

Natural aquatic environments have a heterogeneous composition; therefore, simultaneous exposure to multiple contaminants is relevant and more realistic when assessing exposure and toxicity. This study examines the combinatorial effects of two compounds found ubiquitously in drinking water across the United States: glyphosate and lead acetate. Zebrafish (Danio rerio) embryos were used as a model for investigating developmental delays following controlled exposures.

Rhenium -Tricarbonyl Bisimine Chalcogenide Complexes: Synthesis, Photophysical Studies, and Confocal and Time-Resolved Cell Microscopy.

We describe the preparation, characterization, and imaging studies of rhenium carbonyl complexes with a pyta (4-(2-pyridyl)-1,2,3-triazole) or tapy (1-(2-pyridyl)-1,2,3-triazole)-based heteroaromatic N∧N ligand and thiolate or selenoate X ligand. The stability and photophysical properties of the selenolate complexes are compared with parent chloride complexes and previously described analogues with benzenethiolate ligands. Two complexes were imaged in A549 cells upon excitation at 405 nm.

Selective Transesterification to Control Copolymer Microstructure in the Ring-Opening Copolymerization of Lactide and ε-Caprolactone by Lanthanum Complexes.

A series of novel lanthanum amido complexes, supported by ligands designed around the salan framework (salan = ,'-(-hydroxy, -di--butylbenzyl)-1,2-diaminoethane) were synthesized and fully characterized in the solid and solution states. The ligands incorporate benzyl or 2-pyridyl substituents at each tertiary amine center. The complexes were investigated as catalysts in the ring-opening homopolymerization of lactide (LA) and ε-caprolactone (ε-CL) and copolymerization of equimolar amounts of LA and ε-CL at ambient temperature.

CRISPR/Cas9-mediated knock-in of masu salmon (Oncorhyncus masou) elongase gene in the melanocortin-4 (mc4r) coding region of channel catfish (Ictalurus punctatus) genome.

Channel catfish, Ictalurus punctatus, have limited ability to synthesize Ω-3 fatty acids. The ccβA-msElovl2 transgene containing masu salmon, Oncorhynchus masou, elongase gene driven by the common carp, Cyprinus carpio, β-actin promoter was inserted into the channel catfish melanocortin-4 receptor (mc4r) gene site using the two-hit two-oligo with plasmid (2H2OP) method. The best performing sgRNA resulted in a knockout mutation rate of 92%, a knock-in rate of 54% and a simultaneous knockout/knock-in rate of 49%.

A New Strategy for Increasing Knock-in Efficiency: Multiple Elongase and Desaturase Transgenes Knock-in by Targeting Long Repeated Sequences.

CRISPR/Cas9-mediated knock-in (KI) has a wide application in gene therapy, gene function study, and transgenic breeding programs. Unlike gene therapy, which requires accurate KI to correct gene mutation, transgenic breeding programs can accept robust KI as long as integration does not interrupt normal gene functions and result in any negative pleiotropic effects. High KI efficiency is required to reduce the breeding cost and shorten the breeding period, especially in transferring multiple foreign genes to a single individual.

Improved Growth and High Inheritance of Melanocortin-4 Receptor (mc4r) Mutation in CRISPR/Cas-9 Gene-Edited Channel Catfish, Ictalurus punctatus.

Effects of CRISPR/Cas9 knockout of the melanocortin-4 receptor (mc4r) gene in channel catfish, Ictalurus punctatus, were investigated. Three sgRNAs targeting the channel catfish mc4r gene in conjunction with Cas9 protein were microinjected in embryos and mutation rate, inheritance, and growth were studied. Efficient mutagenesis was achieved as demonstrated by PCR, Surveyor® assay, and DNA sequencing.

Tunable Emissive Ir(III) Benzimidazole-quinoline Hybrids as Promising Theranostic Lead Compounds.

Bioactive and luminescent cyclometallated Ir(III) complexes [Ir(ppy) L1]Cl (1) and [Ir(ppy) L2]Cl (2) containing a benzimidazole derivative (L1/L2) as auxiliary mimic of a nucleotide have been synthesised. The emissive properties of both complexes are conditioned by the nature of L1 and L2, rendering an orange and a green emitter respectively. Both are highly emissive with quantum yield increasing in absence of oxygen up to 0.

Response of cecropin transgenesis to challenge with Edwardsiella ictaluri in channel catfish Ictalurus punctatus.

Constructs bearing the cecropin B gene from the moth Hyalophora cecropia, driven by the cytomegalovirus (CMV) promoter, or the common carp beta-actin (β-actin) promoter were transferred to channel catfish, Ictalurus punctatus via electroporation. One F channel catfish family transgenic for cecropin transgene driven by the CMV promoter, and one F channel catfish family transgenic for cecropin transgene driven by the common carp β-actin promoter were produced. F and F individuals exhibited enhanced disease resistance when challenged in tanks with Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish (ESC).

CRISPR/Cas9-Mediated Transgenesis of the Masu Salmon (Oncorhynchus masou) elovl2 Gene Improves n-3 Fatty Acid Content in Channel Catfish (Ictalurus punctatus).

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), play a very important role in human health. Channel catfish (Ictalurus punctatus) is one of the leading freshwater aquaculture species in the USA, but has low levels of EPA and DHA compared to some fish such as salmon. To improve EPA and DHA content, a modification of the n-3 PUFA biosynthetic pathway was achieved through the insertion of an elovl2 transgene isolated from masu salmon (Oncorhynchus masou) driven by a carp β-actin promoter using a two-hit by gRNA and two oligos with a targeting plasmid (2H2OP) CRISPR/Cas9 approach.

Answering a Call to Action on American Workplace and Community Opioid Concerns.

Leidos, Inc. is a large government science and technology company. When a Leidos employee lost his son to an opioid overdose, he wrote an impassioned email to the CEO, asking him to take action related to the growing societal problem of opioid use disorders.

Effectiveness of Cathelicidin Antimicrobial Peptide against Ictalurid Catfish Bacterial Pathogens.

One of the major goals in aquaculture is to protect fish against infectious diseases as disease outbreaks could lead to economic losses if not controlled. Antimicrobial peptides (AMPs), a class of highly conserved peptides known to possess direct antimicrobial activities against invading pathogens, were evaluated for their ability to protect Channel Catfish Ictalurus punctatus and hybrid catfish (female Channel Catfish × male Blue Catfish I. furcatus) against infection caused by the fish pathogen Aeromonas hydrophila ML09-119.

Photochemical Oxidation of Pt(IV)Me(1,2-diimine) Thiolates to Luminescent Pt(IV) Sulfinates.

We report the formation of dinuclear complexes from, and photochemical oxidation of, (CH)-Pt(IV)(N^N) (N^N = 1,2-diimine derivatives) complexes of thiophenolate ligands to the analogous sulfinates (CH)Pt(N^N)(SOPh) and structural, spectroscopic, and theoretical studies of the latter revealing tunable photophysics depending upon the 1,2-diimine ligands. Electron-rich thiolate and conjugated 1,2-diimines encourage formation of thiolate-bridged dinuclear complexes; smaller 1,2-diimines or electron-poor thiolates favor mononuclear complexes. Photooxidation of the thiolate ligand yields hitherto unreported Pt(IV)-SOR complexes, promoted by electron-deficient thiolates such as 4-nitrothiophenol, which exclusively forms the sulfinate complex.

CRISPR/Cas9-mediated knock-in of alligator cathelicidin gene in a non-coding region of channel catfish genome.

CRISPR/Cas9-based gene knockout in animal cells, particularly in teleosts, has proven to be very efficient with regards to mutation rates, but the precise insertion of exogenous DNA or gene knock-in via the homology-directed repair (HDR) pathway has seldom been achieved outside of the model organisms. Here, we succeeded in integrating with high efficiency an exogenous alligator cathelicidin gene into a targeted non-coding region of channel catfish (Ictalurus punctatus) chromosome 1 using two different donor templates (synthesized linear dsDNA and cloned plasmid DNA constructs). We also tested two different promoters for driving the gene, zebrafish ubiquitin promoter and common carp β-actin promoter, harboring a 250-bp homologous region flanking both sides of the genomic target locus.

Development of a spermatogonia cryopreservation protocol for blue catfish, Ictalurus furcatus.

Sustainability of channel catfish, Ictalurus punctatus ♀ × blue catfish, Ictalurus furcatus ♂ hybrid aquaculture relies on new innovative technologies to maximize fry output. Transplanting spermatogonial stem cells (SSCs) from blue catfish into channel catfish hosts has the potential to greatly increase gamete availability and improve hybrid catfish fry outputs. Cryopreservation would make these cells readily accessible for xenogenesis, but a freezing protocol for blue catfish testicular tissues has not yet been fully developed.

Silicon photosensitisation using molecular layers.

Silicon photosensitisation via energy transfer from molecular dye layers is a promising area of research for excitonic silicon photovoltaics. We present the synthesis and photophysical characterisation of vinyl and allyl terminated Si(111) surfaces decorated with perylene molecules. The functionalised silicon surfaces together with Langmuir-Blodgett (LB) films based on perylene derivatives were studied using a wide range of steady-state and time resolved spectroscopic techniques.

Reduction in testing and change in testing algorithm associated with decrease in number of nosocomial Clostridioides (Clostridium) difficile infections.

Objective: To evaluate the effects of a best practice advisory (BPA) and a change in the Clostridioides (Clostridium) difficile testing algorithm on nosocomial C. difficile infection (CDI) rates.

Methods: This was a retrospective analysis at a tertiary care hospital of adult patients who tested positive for CDI between July 1, 2017 and September 30, 2019.

Development, characterisation and in vitro evaluation of lanthanide-based FPR2/ALX-targeted imaging probes.

We report the design, preparation and characterisation of three small-molecule, Formyl Peptide Receptor (FPR)-targeted lanthanide complexes (Tb·14, Eu·14 and Gd·14). Long-lived, metal-based emission was observed from the terbium complex (τH2O = 1.9 ms), whereas only negligible lanthanide signals were detected in the europium analogue.

Average orientation of a fluoroaromatic molecule in lipid bilayers from DFT-informed NMR measurements of H-F dipolar couplings.

Fluorine is often incorporated into the aromatic moieties of synthetic bioactive molecules such as pharmaceuticals and disease diagnostics in order to alter their physicochemical properties. Fluorine substitution may increase a molecule's lipophilicity, thereby enabling its diffusion across cell membranes to enhance bioavailability or to exert a direct physiological effect from within the lipid bilayer. Understanding the structure, dynamics and orientation of fluoroaromatic molecules in lipid bilayers can provide useful insight into the effect of fluorine on their mode of action, and their interactions with membrane-embedded targets or efflux proteins.

Self-assembly of singlet-emitting double-helical silver dimers: the curious coordination chemistry and fluorescence of bisquinolylpyridone.

2,6-Bis(2-quinolyl)-4(1H)-pyridone 1, a novel quinoline analogue of the well-known ligand 2-terpyridone, shows unusual fluorescence with a large Stokes shift and low energy emission. Pyridine-pyridone tautomerism is investigated by NMR and theoretical methods and indicates that the low energy emission is from the pyridine form. 1 reacts with Ag(i) salts to give a double helical AgN core showing a BLUE shift in fluorescence with respect to the free ligand, which has been characterised experimentally and theoretically as involving an unusual mixed MLCT/ILCT excited state and emission from a singlet state.

Blue rhenium tricarbonyl DPPZ complexes - low energy charge-transfer absorption at tissue-penetrating wavelengths.

fac-[Re(CO)(dppz)] complexes of amido ligands generated in situ under basic conditions display an intense (ε = 16460 L mol cm) absorption band between 500-700 nm which are assigned to an n(amido,RNH-) → π* (dppz) inter-ligand charge transfer band offering an extraordinarily low energy charge separating absorption with potential for imaging and energy application.

The redox-active drug metronidazole and thiol-depleting garlic compounds act synergistically in the protist parasite Spironucleus vortens.

Spironucleus vortens is a protozoan parasite associated with significant mortalities in the freshwater angelfish, Pterophyllum scalare. Control of this parasite is especially problematic due to restrictions on the use of the drug of choice, metronidazole (MTZ), on fish farms. Use of garlic (Allium sativum) is undergoing a renaissance following experimental validations of its antimicrobial efficiency.

Ventilator-Associated Pneumonia in Trauma Patients: Different Criteria, Different Rates.

Background: No consensus exists regarding the definition of ventilator-associated pneumonia (VAP). Even within a single institution, inconsistent diagnostic criteria result in conflicting rates of VAP. As a Level 1 trauma center participating in the Trauma Quality Improvement Project (TQIP) and the National Healthcare Safety Network (NHSN), our institution showed inconsistencies in VAP rates depending on which criteria was applied.

Platinum trimethyl bipyridyl thiolates--new, tunable, red- to near IR emitting luminophores for bioimaging applications.

Synthetic, spectroscopic, computational and biological imaging studies of platinum trimethyl bipyridyl thiolate complexes of the general formula [PtMe3(bpy)SR] reveal these to be easily accessed, tunable bioimaging agents which feature an unusual σ-π* Inter-Ligand Charge Transfer (ILCT) transition, and in some cases emit into the Near infra-red (NIR).