Physical Sciences and Mathematics Commons^™

Solvent Stable Microbial Lipases: Current Understanding And Biotechnological Applications, Barry Ryan, Priyanka Priyanka, Yeqi Tan, Gemma K Kinsella, Gary T. Henehan

Articles

Objective: This review examines on our current understanding of microbial lipase solvent tolerance, with a specific focus on the molecular strategies employed to improve lipase stability in a non-aqueous environment.

Results: It provides an overview of known solvent tolerant lipases and of approaches to improving solvent stability such as; enhancing stabilising interactions, modification of residue flexibility and surface charge alteration. It shows that judicious selection of lipase source supplemented by appropriate enzyme stabilisation, can lead to a wide application spectrum for lipases.

Conclusion: Organic solvent stable lipases are, and will continue to be, versatile and adaptable biocatalytic workhorses commonly employed …

Regeneration Of Aged Dmf For Use In Solid-Phase Peptide Synthesis, Jordan K. Magtaan, Marc Devocelle, Fintan Kelleher

Articles

DMF, which is still the most commonly used solvent for Fmoc-SPPS, has the potential for degradation over time on exposure to air (and water vapour) and storage, to give dimethylamine and formic acid impurities. In particular, dimethylamine can lead to unwanted deprotection of the Fmoc group during for example the initial loading of Fmoc amino acids in SPPS, which leads reduced calculated loading values. We have found that treatment of such aged DMF by simple sparging with an inert gas (N₂), or vacuum sonication, can regenerate the DMF in order to restore loading levels back to those found …

Conformational Studies Of Gram-Negative Bacterial Quorum Sensing Acyl Homoserine Lactone (Ahl) Molecules: The Importance Of The N→* Interaction, Fintan Kelleher, Goar Sánchez-Sanz, Darren Crowe, Alan Nicholson, Adrienne Fleming

Articles

A ¹H NMR study shows the presence of intermolecular hydrogen bonds for AHLs in CDCl₃ solution. A detailed computational study of the structure of AHLs and the relative stability between the extended conformations (X) and those showing n→p* interactions (np) have been carried out by means of DFT calculations. Solvent effects have been shown to be very important when stabilising np conformations, particularly with polar solvents. This was shown by the shortening of C···O intramolecular distances and the increase in the relative energies favouring the np conformation with the dielectric constant of the solvent. …

Investigation Of Temperature Response Of Photopolymer Material Used For Holographic Sensor, Muhammad Irfan, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova

Conference Papers

Recently, functionalised photopolymer has emerged as a versatile recording material in the field of optical holography due to its novel characteristics and potential use in the development of holographic based sensors, and optical elements. This work describes the temperature response of a newly developed photopolymer, containing of a monomer Nisopropylacrylamide (NIPA) which under photopolymerisation forms a temperature sensitive polymer - Poly(Nisopropylacrylamide) (PNIPA). The photonic sensor was developed by holographic recording of volume phase transmission gratings in a self-processing NIPA-based polymer with a 532 nm laser beam. A 633 nm probe beam was used to monitor real time diffraction efficiency (DE) …

In Vitro Label Free Screening Of Chemotherapeutic Drugs Using Raman Micro-Spectroscopy: Towards A New Paradigm Of Spectralomics., Zeineb Farhane, Haq Nawaz, Franck Bonnier, Hugh Byrne

Articles

This overview groups some of the recent studies highlighting the potential application of Raman micro-spectroscopy as an analytical technique in preclinical development to predict drug mechanism of action and in clinical application as a companion diagnostic and in personalised therapy due to its capacity to predict cellular resistance and therefore to optimise chemotherapeutic treatment efficacy.

Notably, the anthracyclines, Doxorubicin and Actinomycin D, elicit similar spectroscopic signatures of subcellular interaction characteristic of the mode of action of intercalation. Although Cisplatin and Vincristine show markedly different signatures, at low exposure doses, their signatures at higher doses show marked similarities to those elicited …

Confocal Raman Spectroscopic Imaging For In Vitro Monitoring Of Active Ingredient Penetration And Distribution In Reconstructed Human Epidermis Model, Lynda Miloudi, Franck Bonnier, Ali Tfayli, Florent Yvergnaux, Hugh Byrne, Igor Chourpa, Emilie Munnier

Articles

Topically applied Active Cosmetic Ingredients (ACI) or Active Pharmaceutical Ingredients (API) efficacy is directly related to their efficiency of penetration in the skin. In vitro Reconstructed Human Epidermis (RHE) surrogate models offer in vivo like skin samples for transdermal studies. Using Delipidol®, an ACI currently used in the cosmetics industry, the capabilities to deliver accurate distribution maps and penetration profiles of this molecule by means of Confocal Raman spectroscopic Imaging have been demonstrated. Using a NCLS (Non negative constrained least squares) approach, contribution of specific molecules can be estimated at each point of spectral maps in order to deliver semi-quantitative …

Protection Of Triplet Excited State Materials From Oxygen Quenching And Photooxidation In Optical Sensing Applications, Mikhail Filatov

Books/Book chapters

No abstract provided.

Comparison Of Fungal Spores Concentrations Measured With Wideband Integrated Bioaerosol Sensor And Hirst Methodology, S. Fernández-Rodríguez, R. Tormo-Molina, N. Lemonis, B. Clot, David O'Connor, John R. Sodeau

Articles

The aim of this work was to provide both a comparison of traditional and novel methodologies for airborne spores detection (i.e. the Hirst Burkard trap and WIBS-4) and the first quantitative study of airborne fungal concentrations in Payerne (Western Switzerland) as well as their relation to meteorological parameters. From the traditional method -Hirst trap and microscope analysis-, sixty-three propagule types (spores, sporangia and hyphae) were identified and the average spore concentrations measured over the full period amounted to 4145 ± 263.0 spores/m3. Maximum values were reached on July 19th and on August 6th. Twenty-six spore types reached average levels above …

The Janus-Faced Chromophore: A Donor-Acceptor Dyad With Dual Performance In Photon Up-Conversion, Natalia Kiseleva, Mikhail Filatov, Michael Oldenburg, Dimitry Busko, Marius Jakoby, Ian Howard, Bryce Richards, Mathias Senge, Sergey Borisov, Andrey Turshatov

Articles

An electron donor-acceptor dyad based on BODIPY (acceptor) and anthracene (donor) plays either the role of sensitizer or emitter in triplet-triplet annihilation photon up-conversion (TTA-UC). This Janus-like behavior was achieved via altering the relative ordering of charge-transfer and local excited state energies in the dyad through the polarity of TTA-UC media.

The Role Of The Hydrolysis And Zirconium Concentration On The Structure And Anticorrosion Performances Of A Hybrid Silicate Sol-Gel Coating, Maikki Cullen, Mary O’Sullivan, Aditya Madhan Kumar, Ahmad A. Sorour, Brendan Duffy, Mohamed Oubaha

Articles

In sol-gel chemistry, hydrolysis is the key step in the formation of the reactive hydroxide groups that are responsible for the formation of inorganic networks via the occurrence of condensation reactions. Though previous studies have investigated the effect of the hydrolysis conditions on the structure of organically modified silicates (ormosils), no study, to our knowledge, has investigated this variable on the structure of hybrid materials prepared by combinations of an ormosil and a transition metal (TM). Here, we propose to investigate this effect in a hybrid material composed of 3-trimethoxysilylpropylmethacrylate and a zirconium complex. To also highlight the effects of …

A Novel Quantitative Electrochemical Method To Monitor Dna Double-Strand Breaks Caused By A Dna Cleavage Agent At A Dna Sensor, Anna Banasiak, John Cassidy, John Colleran

Articles

Biosensors and Bioelectronics, Vol. 117

A Comparison Of On-Line And Off-Line Bioaerosol Measurements At A Biowaste Site, Patrick Feeney, Santiago Fernández Rodríguez, Rafael Molina, Eoin Mcgillicuddy, Stig Hellebust, Michael Quirke, Shane Daly, David O'Connor, John Sodeau

Articles

An air measurement campaign was carried out at a green-waste composting site in the South of Ireland during Spring 2016. The aim was to quantify and identify the levels of Primary Biological Aerosol Particles (PBAP) that were present using the traditional off-line, impaction/optical microscopy method alongside an on-line, spectroscopic approach termed WIBS (Wideband Integrated Bioaerosol Sensor), which can provide number concentrations, sizes and “shapes” of airborne PBAP in real-time by use of Light Induced Fluorescence (LIF). The results from the two techniques were compared in order to validate the use of the spectroscopic method for determining the releases of the …

Environmental Impact Assessment Of Pinaceae Airborne Pollen And Green Infrastructure Using Bim, Santiago Fernández-Rodríguez, Juan Pedro Cortés-Pérez, Paloma Prieto Muriel, Rafael Tormo-Molina, J. M. Maya-Manzano

Articles

Urban air quality is a parameter that plays a major role in human health at the local scale. Consequently, in urban planning, the behavior and potential risk of allergenicity for some pollen grains coming from ornamental trees and green spaces surrounding newly built buildings, should be considered. This paper aims to study how pollen exposure, influenced by weather parameters, can be assessed and integrated in the designing and building of constructions as other component of air quality assessment beforehand, by using BIM. Based on a comparative aerobiological study at the height over a building (sampled by two traps at ground …

Synthesis, Characterisation And Dna Intercalation Studies Of Regioisomers Of Ruthenium (Ii) Polypyridyl Complexes, Laura Perdisatt, Samar Moqadasi, Luke O'Neill, Gary Hessman, Alessandra Ghion, Muhammad Qasim Mushtaq Warraich, Alan Casey, Christine O'Connor

Articles

Regioisomers of the functional group of the main ligand (L) on a series of [Ru(phen)2L]2+and [Ru(bpy)2L]2+ complexes, where phen is 1,10 phenanthroline and bpy is 2,2′-bipyridine, were synthesised to investigate the interaction with deoxyribonucleic acid (DNA) as potential therapeutics. UV–Vis binding titrations, thermal denaturation and circular dichroism were used to evaluate their interaction with DNA. The conclusions indicated the significance of the auxiliary ligand; especially 1,10-phenanthroline has on the binding constants (Kb). The systematic variation of auxiliary ligand(phen or bpy), and polypyridyl ligand (4-(1H-Imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzonitrile (CPIP), 2-(4-formylphenyl)imidazo[4,5-f] [1,10] phenanthroline (FPIP), 2-(4-bromophenyl)imidazo[4,5-f][1,10]phenanthroline (BPIP) and 2-(4-nitrophenyl)imidazo[4,5-f] [1,10] phenanthroline (NPIP), split in terms of …

Robust, Bridge-Less Ion-Selective Electrodes With Significantly Reduced Need For Pre- And Post-Application Handling, Benjamin Schazmann, S. Demey, Z. Waqar Ali, M-S Plissart, E. Brennan, A. Radu

Articles

We are demonstrating robust, single-layer ion-selective electrode (ISE) utilizing simple Ag/AgCl electrode as solid support without the need for intermediate polymer layer. We have created and chemically linked a family of imidazolium ionic liquids (ILs) with poly (vinyl chloride) (PVC) using click chemistry, resulting in hybrid materials with tunable characteristics. The resultant material inherently contains chloride ion thus offering the ability to stabilize interfacial potential. This allowed us to construct very simple, single-layer membranes with significantly reduced need for conditioning as an added bonus compared to traditional sensors. Chemical immobilization of ISE membrane components also led to extended lifetime as …

Conformational Studies Of Gram-Negative Bacterial Quorum Sensing Acyl Homoserine Lactone (Ahl) Molecules: The Importance Of The N → Π* Interaction, Goar Sánchez-Sanz, Darren Crowe, Alan Nicholson, Adrienne Fleming, Ed Carey, Fintan Kelleher

Articles

A 1H NMR study shows the presence of intermolecular hydrogen bonds for AHLs in CDCl3 solution. A detailed computational study of the structure of AHLs and the relative stability between the extended conformations (X) and those showing n → π* interactions (np) have been carried out by means of DFT calculations. Solvent effects have been shown to be very important when stabilising np conformations, particularly with polar solvents. This was shown by the shortening of C⋯O intramolecular distances and the increase in the relative energies favouring the np conformation with the dielectric constant of the solvent. The charge transfer between …

Disposable Printed Lateral Flow Electrochemical Immunosensors For Human Cardiac Troponin T, Eithne Dempsey, Dhanraj Rathod

Articles

Here we report an electrochemical ELISA approach for cardiac Troponin T (cTnT) determination based on a lateral flow membrane with underlying screen printed electrodes (<;100 Ω /cm 2 ). The thick film transducer was modified with the anti-cardiac Troponin T antibody via physisorption and the electrochemical performance of the immunosensor was evaluated using cyclic voltammetry. The capture antibody coated immunoelectrode employed for electrochemical determination of Troponin T antigen used a sandwich assay format with horseradish peroxidase conjugated signaling antibodies held in the track of a lateral flow sensor strip. A simple two step procedure realized signal acquisition within <;20 min (total assay time). The lateral flow electrochemical immunosensor response resulted in a calibration curve with linear response (0-700 ng/ml cTnT) with limit of detection of 0.15 ng/ml.

Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Patrick Cullen, Vladimir Milosavljević

Articles

The use of plastics has spanned across almost all aspects of day to day life. Although their uses are invaluable, they contribute to the generation of a lot of waste products that end up in the environment and end up polluting natural habitats such as forests and the ocean. By treating low-density polyethylene (LDPE) samples with non-thermal plasma in ambient air and with an addition of ≈4% CO2, the biodegradation of the samples can be increased due to an increase in oxidative species causing better cell adhesion and acceptance on the polymer sample surface. It was, however, found that the …

Targeting The Folate Receptor: Improving Efficacy In Inorganic Medicinal Chemistry, Pauraic Mccarron, Aisling Crowley, Denis O'Shea, Malachy Mccann, Orla L. Howe, Mary Hunt, Michael Devereux

Articles

The discovery of the high-affinity, high-specificity folate receptor in mamalian kidney cells, coupled with the ability of folate to enter cells by folate receptor-mediated endocytosis and the subsequent elucidation of the folate receptor’s overexpression in specific cancer cell types; heralded the arrival of the area of chemotherapeutic folate targeting. The application of purely organic folate-based small-molecule drug conjugates that selectively target the folate receptor, which is over expressed in several diseases such as cancer, is well established. The application of inorganic folate-targeted drugs offers significant potential to expand and enhance this therapeutic approach. From the data made available to date, …

Chemical Modifications Of Lipids And Proteins By Nonthermal Food Processing Technologies, Juan M. PéRez-AndréS, CléMentine Charoux, Patrick J. Cullen, Brijesh K. Tiwari

Articles

A range of nonthermal techniques have demonstrated process efficacy in ensuring product safety, extension of shelf life, and in general a retention of key quality attributes. However, various physical, chemical and biochemical effects of nonthermal techniques on macro and micro nutrients are evident, leading to both desirable and undesirable changes in food products. The objective of this review is to outline the effects of nonthermal techniques on food chemistry and the associated degradation mechanisms with the treatment of foods. Oxidation is one of the key mechanisms responsible for undesirable effects induced by nonthermal techniques. Degradation of key macromolecules largely depends …

Unprecedented In Vitro Antitubercular Activitiy Of Manganese(Ii) Complexes Containing 1,10- Phenanthroline And Dicarboxylate Ligands: Increased Activity, Superior Selectivity, And Lower Toxicity In Comparison To Their Copper(Ii) Analogs, Pauraic Mccarron, Malachy Mccann, Michael Devereux, Kevin Kavanagh, Ciaran M. Skerry, Petros C. Karakousis, Ana Carolina Aor, Thaís P. Mello, Dos Santos, André Luis Souza Dos Santos, André Luis Souza, Débora Leite Campos, Fernando R. Pavan

Articles

Mycobacterium tuberculosis is the etiologic agent of tuberculosis. The demand for new chemotherapeutics with unique mechanisms of action to treat (multi)resistant strains is an urgent need. The objective of this work was to test the effect of manganese(II) and copper(II) phenanthroline/dicarboxylate complexes against M. tuberculosis. The water-soluble Mn(II) complexes, [Mn2(oda)(phen)4(H2O)2][Mn2(oda)(phen)4(oda)2]·4H2O (1) and ([Mn(3,6,9-tdda)(phen)2]·3H2O·EtOH)n (3) (odaH2 = octanedioic acid, phen = 1,10-phenanthroline, tddaH2 = 3,6,9-trioxaundecanedioic acid), and water-insoluble complexes, [Mn(ph)(phen)(H2O)2] (5), [Mn(ph)(phen)2(H2O)]·4H2O (6), [Mn2(isoph)2(phen)3]·4H2O (7), ([Mn(phen)2(H2O)2])2(isoph)2(phen)·12H2O (8) and [Mn(tereph)(phen)2]·5H2O (9) (phH2 = phthalic acid, isophH2 = isophthalic acid, terephH2 = terephthalic acid), robustly inhibited the viability of M. tuberculosis strains, H37Rv …