No abstract

The efficiency of osmotic backwashing cleaning to remove bacteria from forward osmosis membranes was systematically studied for the first time under different attachment and osmotic backwashing conditions. It is hypothesised that biofouling is preventable when tackling initial adhesion, i.e. during the reversible stage. Cell removal from the membrane was dependent on both adhesion and backwashing conditions: tests were performed for backwashing solutions of different concentrations and salt type, as well as different filtration durations and Ca 2+ concentrations in the feed solution.Following adhesion of P. putida, a backwashing draw solution (DSobw) of 3 M NaCl was the most efficient, removing 93% of the adhered cells after 1 minute of backwashing. All adhered cells left on the membrane were dead/injured due to osmotic shock. To optimise the cleaning regime, the maximum filtration time for which backwashing is efficient must be determined. This was determined to be 30 minutes, after which backwashing became inefficient, only removing 78% of cells. The addition of 5 mM Ca 2+ to the feed caused a 50% increase in cell surface coverage compared to adhesion without Ca 2+ . This increase in adhesion rendered backwashing inefficient, as cell removal was only 60%. To increase backwashing efficiency by increasing the backwashing flux, DSobw with CaCl2 were used. However, this was inefficient due to interactions between Ca 2+ in the DSobw and the adhered cells, even for just 1 minute: for a 55.8 L.h -1 m -2 flux, 39% of removal was obtained for a 3 M CaCl2 DSobw when compared to 93% removal for 3 M NaCl for a 36 L.h -1 m -2 flux. Therefore, both adhesion and backwashing conditions are important for cleaning of FO membranes.

Enhancement of fluorescence through the application of plasmonic metal nanostructures has gained substantial research attention due to the widespread use of fluorescence-based measurements and devices. Using a microfabricated plasmonic silver nanoparticle–organic semiconductor platform, we show experimentally the enhancement of fluorescence intensity achieved through electro-optical synergy. Fluorophores located sufficiently near silver nanoparticles are combined with diphenylalanine nanotubes (FFNTs) and subjected to a DC electric field. It is proposed that the enhancement of the fluorescence signal arises from the application of the electric field along the length of the FFNTs, which stimulates the pairing of low-energy electrons in the FFNTs with the silver nanoparticles, enabling charge transport across the metal–semiconductor template that enhances the electromagnetic field of the plasmonic nanoparticles. Many-body perturbation theory calculations indicate that, furthermore, the charging of silver may enhance its plasmonic performance intrinsically at particular wavelengths, through band-structure effects. These studies demonstrate for the first time that field-activated plasmonic hybrid platforms can improve fluorescence-based detection beyond using plasmonic nanoparticles alone. In order to widen the use of this hybrid platform, we have applied it to enhance fluorescence from bovine serum albumin and Pseudomonas fluorescens . Significant enhancement in fluorescence intensity was observed from both. The results obtained can provide a reference to be used in the development of biochemical sensors based on surface-enhanced fluorescence.

Fouling remains a prevalent and serious problem in industries using membrane processes.Efforts to mitigate fouling are improving, however, membrane fouling cannot be completely eliminated. Therefore fouling control via development of sustainable cleaning methods are crucial. Despite osmotic backwashing showing promise, little is understood about this cleaning method for removal of fouling from reverse osmosis (RO) membranes. This paper systematically examines how organic fouling characteristics and osmotic backwashing parameters influence cleaning efficiency. Alginic acid was used as a model foulant and numerous microscopy techniques, including confocal microscopy, scanning electron microscopy and atomic force microscopy were used to examine the membrane fouling before and after cleaning to gain a clearer understanding of the mechanisms involved. Increasing CaCl2 concentration in the fouling solution resulted in an increase in fouling layer thickness from 37 to 179 µm, due to the complexation of Ca 2+ and the carboxyl groups in the alginate.Osmotic backwashing efficiency with 0.7 M NaCl decreased as the fouling layer became thicker and the pure water flux (PWF) recovery decreased from 92% to 81%. Osmotic backwashing efficiency also decreased with increasing initial permeate flux, as less fouling was removed: the fouling generated at higher initial fluxes is largely irreversible, resulting in a denser and more compact fouling layer. In an effort to increase osmotic backwashing flux, a CaCl2 draw solution was used, however, the Ca 2+ ions were found to interact with the alginate in the fouling layer, rendering this method inefficient, when compared to NaCl draw solutions which originated similar osmotic backwashing fluxes. Interestingly, the fouling layer was found to swell from 16 µm to 141 µm, when osmotic backwashing was carried out with a NaCl draw solution, followed by contact with a low ionic strength solution used for PWF testing. This phenomenon does not occur to the same extent after backwashing with CaCl2. The same trends were obtained for bovine serum albumin (BSA) fouling, whilst humic acid (HA) did not display any swelling phenomena. However, it showed the same cleaning inefficiency when using CaCl2 as a draw solution.

The new era of cellular immunotherapies has provided state-of-the-art and efficient strategies for the prevention and treatment of cancer and infectious diseases. Cellular immunotherapies are at the forefront of innovative medical care, including adoptive T cell therapies, cancer vaccines, NK cell therapies, and immune checkpoint inhibitors. The focus of this review is on cellular immunotherapies and their application in the lung, as respiratory diseases remain one of the main causes of death worldwide. The ongoing global pandemic has shed a new light on respiratory viruses, with a key area of concern being how to combat and control their infections. The focus of cellular immunotherapies has largely been on treating cancer and has had major successes in the past few years. However, recent preclinical and clinical studies using these immunotherapies for respiratory viral infections demonstrate promising potential. Therefore, in this review we explore the use of multiple cellular immunotherapies in treating viral respiratory infections, along with investigating several routes of administration with an emphasis on inhaled immunotherapies.