Jean-Louis Luche and the Interpretation of Sonochemical Reaction Mechanisms.

Sonochemistry can be broadly defined as the science of chemical and physical transformations produced under the influence of sound. The use of sound energy is rather a young branch of chemistry and does not have the clear definitive rules of other, more established, divisions such as those in cycloaddition reactions or photochemistry. Nevertheless, there are a few guidelines which can help to predict what is going to happen when a reaction mixture is submitted to ultrasonic irradiation. Jean-Louis Luche, formulated some ideas of the mechanistic pathways involved in sonochemistry more than 30 years ago. He introduced the idea of "true" and "false" sonochemical reactions both of which are the result of acoustic cavitation. The difference was that the former involved a free radical component whereas only mechanical effects played a role the latter. The authors of this paper were scientific collaborators and friends of Jean-Louis Luche during those early years and had the chance to discuss and work with him on the mechanisms of sonochemistry. In this paper we will review the original rules (laws) as predicted by Jean-Louis Luche and how they have been further developed and extended in recent years.

Fatty Acid Ethyl Esters (FAEE): A New, Green and Renewable Solvent for the Extraction of Carotenoids from Tomato Waste Products.

Currently there is a drive towards the minimisation and reclamation of valuable materials from the waste products of the food and beverage industry. This can be achieved through the extraction of residual nutraceuticals from such materials. Tomato pomace contains carotenoids and other chemicals which can be extracted directly into edible oils to improve the health-giving properties of such oils. We report here a novel green solvent, fatty acid ethyl esters (FAEE), which is significantly more effective than sunflower oil and hexane for the extraction of lycopene and beta-carotene from tomato skin waste. FAEE are a non-toxic renewable resource that is environmentally friendly and to our knowledge has never been used as a vegetal extraction fluid. The efficiency of FAEE extraction was significantly improved relative to both sunflower oil and hexane under ultrasound-assisted extraction (UAE) conditions. In addition, FAEE have the additional and significant advantage that once enriched with the extracted nutraceuticals can be used directly as a food additive.

UK trainee-led paediatric governance collaboratives: improving the lives of both trainees and children.

Research is vital to paediatrics; however, many trainees feel there is a deficit in their opportunities, experience and exposure in this area. Three training regions in the UK, the West Midlands, Wales and Peninsula, have recently started region-wide, trainee-led research and governance collaboratives aimed at improving trainee access and education in research, undertaking good quality, multicentre audit, quality improvement and pilot projects in collaboration across the regions and implementing change. We report on the experiences, benefits and challenges of these trainee collaboratives (Paediatric Research Across the Midlands, Wales Research and Education Network and Peninsula Trainee Research Audit and Innovation Network) including a trainee survey looking at how these initiatives have improved skills in conducting multicentre prospective studies, team working skills, leadership, understanding of statistics and manuscripts and presentation skills. We also describe how collaboration with colleagues and participation in projects can benefit trainees in a wider sense of purpose and help to encourage morale, as well as what can be learnt as paediatric training moves forward.

Cytotoxicity Study of Textile Fabrics Impregnated With CuO Nanoparticles in Mammalian Cells.

Copper and copper compounds have multifunctional properties (antibacterial, antiviral, and antifungal) with promising applications. Copper in its nanoparticle (Cu NPs) forms has been widely used in various industrial and commercial applications. In the current research, the cytotoxic effects of textile fabrics impregnated with copper oxide nanoparticles (CuO NPs) were studied in mammalian cell lines. CuO NPs were impregnated onto textile substrates using 2 different techniques: the sonochemical generation and impregnation of NPs from metal complexes ( insitu) and a "throwing the stones" technology using commercially prepared CuO NPs. The cytotoxicity of these 2 textile fabric types was assayed on human dermal fibroblast (HDF) cells and human hepatocellular carcinoma cells (HepG2) and was evaluated by indirect contact using an MTT assay. The impregnated fabrics were not exposed to the cells, rather their leachates were used to test cytotoxicity. The fabrics were soaked into the growth media for up to 7 days, and the leachates from day 1 and day 7 were incubated with the cell lines for 24 hours prior to the testing. The discharge or leaching from antimicrobial nanomaterials into the surroundings and surface waters is posing a serious environmental threat, which needs to be addressed. Hence, with regard to product safety, it is a good approach to study the fabric leachates rather than the intact material. The results showed that CuO NPs are not toxic to HDF cells. However, cytotoxicity was seen in HepG2 cells with cell viability decreasing by 20% to 25% for all the fabrics after 24 hours.

Combined Effect of Ultrasound and Ozone on Bacteria in Water.

The aim of this study is to assess the synergetic effect of combined ultrasound and ozone treatment on the biological disinfection of water on a large-scale application using viable plate counts and flow cytometry. Escherichia coli B bacteria in saline suspension was treated using a commercially available combined ultrasound and ozone system (USO3 (Ultrasonic Systems Gmbh)) for 16 min. Two analytical methods were used to assess the results in terms of live and dead cells in the bulk liquid: standard viable plate counting recorded in terms of colony forming units per milliliter and flow cytometry. In the latter case 1 mL of bacterial suspension was stained simultaneously with the fluorescent stains SYTO9 and propidium iodide (PI). Transmission electron microscopy was used to generate images identifying the biological effects of different treatments using ultrasound and ozone on bacterial cell walls. Results demonstrated that treatment with ozone alone (1 mg/L) resulted in a significant reduction (93%) in the number of live cells after 16 min treatment whereas ultrasound alone showed only a small reduction (24%). However, a combination of ozone and ultrasound showed a synergistic effect and enhanced the inactivation to 99% after 4 min. A combined ultrasound and ozone treatment of bacterial suspensions using a commercial system affords a promising method for water disinfection that is better than treatment using either method alone. Standard viable plate count analysis is normally used to assess the effectiveness of disinfection treatments; however flow cytometry proved to be a more sensitive method to determine the actual effects in terms of not only live and dead cells but also damaged cells. This type of analysis (cell damage) is difficult if not impossible to achieve using traditional plate counting methodology.

A simple new approach for mapping an ultrasonic tank for sonochemistry.

The most used piece of equipment for sonochemistry is the ultrasonic cleaning bath. However, what is sometimes forgotten by scientists new to sonochemistry is the vital importance of the shape and positioning of any reaction vessel in the bath to obtain the most efficient and reproducible results. In experiments using an ultrasonic bath, a glass vessel (reactor) is inserted into the water contained in the bath. The water acts as the coupling medium for the transfer of acoustic energy from the transducer to the vessel (termed indirect sonication). The position of the reaction vessel above the base of the US bath can change the energy transmitted into it over a wide range of values (in our system between 100-500 J). We have carried out a study of the vertical distribution of the ultrasound field in a common type of ultrasound bath, comparing conventional sonochemistry dosimeters with a new and very simple approach using the Ultrasonic Capillary Effect (UCE) which can be performed in any laboratory. The technique involves the use of a capillary tube, to locate the vertical positions of acoustic pressure maxima above a single transducer on the base of the bath. The results are compared with those obtained using calorimetry, iodimetry, a cavitometer and the perforation of aluminium foil. The results show that the optimum position for the reaction vessel can be located very simply using UCE.

Overexpression of NDST1 Attenuates Fibrotic Response in Murine Adipose-Derived Stem Cells.

Adipose-derived stem cells (ADSCs) hold tremendous potential for treating diseases and repairing damaged tissues. Heparan sulfate (HS) plays various roles in cellular signaling mechanisms. The importance of HS in stem cell function has been reported and well documented. However, there has been little progress in using HS for therapeutic purposes. We focused on one of the sulfotransferases, NDST1, which influences overall HS chain extent and sulfation pattern, with the expectation to enhance stem cell function by increasing the N-sulfation level. We herein performed transfections of a green fluorescent protein-vector control and NDST1-vector into mouse ADSCs to evaluate stem cell functions. Overexpression of NDST1 suppressed the osteogenic differentiation of ADSCs. There was no pronounced effect observed on the stemness, inflammatory gene expression, nor any noticeable effect in adipogenic and chondrogenic differentiation. Under the tumor necrosis factor-alpha stimulation, NDST1 overexpression induced several chemokine productions that attract neutrophils and macrophages. Finally, we identified an antifibrotic response in ADSCs overexpressing NDST1. This study provides a foundation for the evaluation of HS-related effects in ADSCs undergoing ex vivo gene manipulation.

Frequency effects on the surface coverage of nitrophenyl films ultrasonically grafted onto indium tin oxide.

The covalent attachment of various organic molecules on conductive supports including indium tin oxide (ITO) using diazonium chemistry has been known for many years. A commonly used method to achieve this is the electrochemical reduction of diazonium compounds leading to radicals, followed by binding of the radicals to the support. In the present report, an alternative method using ultrasound at different frequencies (20, 582, 863, and 1142 kHz) to induce the surface grafting of nitrobenzene diazonium onto an ITO surface is described. It is shown that the grafting on ITO is more efficient in the lower ultrasonic frequency range that is ascribed to changes in the balance between the physical and chemical effects of cavitation with frequency. Both the physical and chemical effects of cavitation play important roles at all frequencies, but at high ultrasound frequencies, the physical effects are relatively small. At 20 kHz, the physical component, including mass transport, is larger than at higher frequencies, and mechanisms based on these observations have been proposed. Ultrasonic grafting has an advantage over electrografting in that it may provide more control over surface coverage, thus it is suggested that the ultrasonic method is used where the surface concentration of the organic layer must be controlled.

Ultrasound-enhanced mass transfer in Halal compared with non-Halal chicken.

BACKGROUND: Halal foods are often perceived as wholesome products that are specially selected and processed to achieve the highest standards of quality. In this study, dye penetration from an aqueous solution of methylene blue (1 mol L(-1)) was used as a model for the marination process of Halal and non-Halal chicken breast. RESULTS: The effect of dye penetration was evaluated by three techniques: (1) the mass of methylene blue solution in the samples was quantified by mass gain, (2) the amount of dye absorbed was determined by spectroscopy and (3) the penetration distance of dye inside the samples was measured. For non-Halal meat, ultrasound increased the amount of dye inside the samples by 6 and 13% after 15 and 30 min respectively. The effect on Halal meat was much more pronounced, with an increase in dye uptake of over 60% being observed for both time periods. CONCLUSION: Dye penetration is an indication of meat permeability and so can be used as an estimate of marinading of meat. Thus the use of high-power ultrasound has potential in poultry-processing methods, in particular that of Halal chicken marination.

Role of the prescriber in supporting patients to discontinue benzodiazepines: a qualitative study.

BACKGROUND: Given the prevalence of long-term benzodiazepine (BZD) prescribing, increased monitoring through the implementation of prescription monitoring programmes (PMPs) may be the necessary impetus to promote BZD deprescribing. Despite evidence promoting the importance of patient-centred care, GPs have not been sufficiently supported to implement these principles through current deprescribing practice. AIM: To investigate patients' perception of their prescriber's influence on ceasing BZD use, including their willingness to take their advice, and to understand how a patient's stage of change influences the barriers and facilitators they perceive to discontinuing BZDs. DESIGN AND SETTING: An online survey and qualitative interviews with 22 long-term users of BZD (≥6 months), aged 18-69 years, recruited from the general population in Victoria, Australia. METHOD: Two groups of users of BZD participated, one in the process of reducing their BZD and one not reducing, and were categorised according to their stage of change. Data underwent thematic analysis to identify barriers and facilitators to reducing BZDs both at the patient level and the prescriber level. RESULTS: BZD patients' perceptions of the prescriber influence were characterised by prescribing behaviours, treatment approach, and attitude. Barriers and facilitators to reducing their BZD were mapped against their stage of change. Irrespective of their stage of change, participants reported they would be willing to try reducing their BZD if they trusted their prescriber. CONCLUSION: This study illustrates that, with a few key strategies at each step of the deprescribing conversation, GPs are well positioned to tackle the issue of long-term BZD use in a manner that is patient centred.

A new reactor for process intensification involving the simultaneous application of adjustable ultrasound and microwave radiation.

Ultrasound (US) and Microwaves (MW) are effective methods for processes intensification. Their combined use in the same reactor can lead to remarkable results. Recently there has been a resurgence of interest in this field for new synthetic applications using reactors based upon existing technologies. We describe here a new type of apparatus in which the thermal energy is continuously removed from the system making possible the use of high power and adjustable ultrasonic and microwave densities throughout the process. The installation consists of a glass reactor located in a monomode applicator which is immersed at the same time in an ultrasonic device which can be operated at different frequencies and powers. A liquid, transparent to microwaves, was used to couple ultrasonic energy to the reactor and to remove the heat generated. Comsol software was used to get information about the distribution of ultrasonic and microwave energy between the reactor liquid and the coupling fluid. The performance was assessed using the conversion of p-nitrophenol into 4-nitrocatechol as a chemical dosimeter and a transesterification.

Effect of ultrasonic frequency and power on algae suspensions.

Cyanobacteria are photosynthetic bacteria with some characteristics of algae. Some cyanobacteria produce toxins that have been shown to be hazardous to both animals and humans. Previous research has demonstrated power ultrasound can provide a suitable method to control algae blooms although the optimum ultrasonic parameter settings have not been determined to ensure an effective and energy efficient treatment. In this work the effect of ultrasound on suspensions of Microcystis aeruginosa has been investigated at the following frequencies 20, 40, 580, 864 and 1146 kHz. Results showed that the reduction in algal numbers is dependent on both frequency and intensity. In order to quantify the effect we have defined the efficiency of the ultrasonic control of algae at a specific frequency as: (% inactivation of the algae) / (ultrasonic intensity applied). When this is applied to the results at different frequencies the order of efficiency for algae reduction is 20 < 1146 < 864 < 580 kHz. This suggests that ultrasound can offer a suitable method for algae inactivation or control but the sonication conditions must be taken into account.

30 Years of sonochemistry links with China.

Most scientists consider that sonochemistry became recognised as a discrete subject in the 1980's - some 40 years ago which coincidentally is when my own interests in the subject began. This review briefly outlines how I first became involved in sonochemistry and then in its development. However its main theme is the way in which my links with China through sonochemistry have developed from their beginnings in 1990. This was the subject of my presentation at AOSS4 and involves a range of topics which started with the extraction of natural products and surface treatment but later expanded to include therapeutic ultrasound and environmental protection.

Targeted De Novo Centromere Formation in Drosophila Reveals Plasticity and Maintenance Potential of CENP-A Chromatin.

Centromeres are essential for accurate chromosome segregation and are marked by centromere protein A (CENP-A) nucleosomes. Mis-targeted CENP-A chromatin has been shown to seed centromeres at non-centromeric DNA. However, the requirements for such de novo centromere formation and transmission in vivo remain unknown. Here, we employ Drosophila melanogaster and the LacI/lacO system to investigate the ability of targeted de novo centromeres to assemble and be inherited through development. De novo centromeres form efficiently at six distinct genomic locations, which include actively transcribed chromatin and heterochromatin, and cause widespread chromosomal instability. During tethering, de novo centromeres sometimes prevail, causing the loss of the endogenous centromere via DNA breaks and HP1-dependent epigenetic inactivation. Transient induction of de novo centromeres and chromosome healing in early embryogenesis show that, once established, these centromeres can be maintained through development. Our results underpin the ability of CENP-A chromatin to establish and sustain mitotic centromere function in Drosophila.

Ultrasound assisted preparation of calcium alginate beads to improve absorption of Pb+2 from water.

Calcium alginate (CaAlg) beads were prepared using ultrasound for use in the removal of lead from natural and wastewaters by ion exchange. Ultrasound was applied in a batch mode with an ultrasonic bath or in a flow mode using an ultrasonic clamp-on device. For comparison purposes the synthesis was performed in batch mode in the absence of the ultrasound. The beads prepared using ultrasound showed a greater ion exchange capability which could be ascribed to a larger specific surface area as a result of surface roughening induced by cavitation. Scanning Electron Microscopy (SEM) images revealed that the roughening was in the form of corrugation for the product with the best ion exchange capability obtained in the flow process where preformed CaAlg droplets were subjected to ultrasound during the setting process. These beads performed 11% better for lead removal than those synthesized in the absence of ultrasound.

Ultrasonic stimulation of the brain to enhance the release of dopamine - A potential novel treatment for Parkinson's disease.

Parkinson's disease (PD) is characterized by the decrease of dopamine (DA) production and release in the substantia nigra and striatum regions of the brain. Transcranial ultrasound has been exploited recently for neuromodulation of the brain in a number of fields. We have stimulated DA release in PC12 cells using low-intensity continuous ultrasound (0.1 W/cm2 - 0.3 W/cm2, 1 MHz), 12 h after exposure at 0.2 W/cm2, 40 s, the amount of DA content eventually increased 78.5% (p = 0.004). After 10-day ultrasonic treatment (0.3 W/cm2, 5 min/d), the DA content in the striatum of PD mice model restored to 81.07% of the control (vs 43.42% in the untreated PD mice model). In addition to this the locomotion activity was restored to the normal level after treatment. We suggest that the low intensity ultrasound-induced DA release can be attributed to a combination of neuron regeneration and improved membrane permeability produced by the mechanical force of ultrasound. Our study indicates that the application of transcranial ultrasound applied below FDA limits, could provide a candidate for relatively safe and noninvasive PD therapy through an amplification of DA levels and the stimulation of dopaminergic neuron regeneration without contrast agents.

Ultrasound-mediated DNA transfer for bacteria.

In environmental microbiology, the most commonly used methods of bacterial DNA transfer are conjugation and electroporation. However, conjugation requires physical contact and cell-pilus-cell interactions; electroporation requires low-ionic strength medium and high voltage. These limitations have hampered broad applications of bacterial DNA delivery. We have employed a standard low frequency 40 kHz ultrasound bath to successfully transfer plasmid pBBR1MCS2 into Pseudomonas putida UWC1, Escherichia coli DH5alpha and Pseudomonas fluorescens SBW25 with high efficiency. Under optimal conditions: ultrasound exposure time of 10 s, 50 mM CaCl(2), temperature of 22 degrees C, plasmid concentration of 0.8 ng/microl, P. putida UWC1 cell concentration of 2.5 x 10(9) CFU (colony forming unit)/ml and reaction volume of 500 microl, the efficiency of ultrasound DNA delivery (UDD) was 9.8 +/- 2.3 x 10(-6) transformants per cell, which was nine times more efficient than conjugation, and even four times greater than electroporation. We have also transferred pBBR1MCS2 into E. coli DH5alpha and P. fluorescens SBW25 with efficiencies of 1.16 +/- 0.13 x 10(-6) and 4.33 +/- 0.78 x 10(-6) transformants per cell, respectively. Low frequency UDD can be readily scaled up, allowing for the application of UDD not only in laboratory conditions but also on an industrial scale.

Sonoelectrochemical synthesis of nanoparticles.

This article reviews the nanomaterials that have been prepared to date by pulsed sonoelectrochemistry. The majority of nanomaterials produced by this method are pure metals such as silver, palladium, platinum, zinc, nickel and gold, but more recently the syntheses have been extended to include the preparation of nanosized metallic alloys and metal oxide semiconductors. A major advantage of this methodology is that the shape andsize of the nanoparticles can be adjusted by varying the operating parameters which include ultrasonic power, current density, deposition potential and the ultrasonic vs electrochemical pulse times. Together with these, it is also possible to adjust the pH, temperature and composition of the electrolyte in the sonoelectrochemistry cell.

Can sonochemistry take place in the absence of cavitation? - A complementary view of how ultrasound can interact with materials.

A hypothesis is advanced for a mechanism by which ultrasound could help to activate chemical reactions, even in the absence of cavitation. It is suggested that the compression phase of an acoustic wave could produce transient solid-like structures within the solution. These structures would result in an "ordering effect" of the molecules in which electrical charges could develop. Such electrical charges could facilitate electron movement from one molecule to another triggering therefore chemical reactions. Such reactions could occur even in the absence of cavitation especially if the solvent or reagents employed show piezoelectric/electrostriction properties. Similar transient ordering effects could be induced by the shockwave accompanying bubble collapse and these would help to explain some of the anomalous effects observed in sonochemistry under cavitation.

The Effect of Focused Ultrasound on Magnetic Polyelectrolyte Capsules Loaded with Dye When Suspended in Tissue-Mimicking Gel.

BACKGROUND: Capsules containing a dye were prepared by the LbL method with iron oxide nanoparticles (50 nm) in different layers of the shell. METHOD: The capsules were dispersed in a gel and subjected to focused ultrasonic irradiation at three different powers and exposure times. RESULT: It was found that the inclusion of iron oxide magnetic nanoparticles in any of the polyelectrolyte shells (4, 6, 8 and 10) strengthened the capsules with respect to capsules without nanoparticles. Incorporation of nanoparticles in shell 8 provided the most resistance to fragmentation under focused ultrasonic irradiation. The relative degree of capsule stability is dependent on both the power of the ultrasound and the exposure time. CONCLUSION: The presence of iron oxide nanoparticles not only conferred more resistance to fragmentation but also provided a route to protein labelled dye release through sonoporation that was not present for capsules without nanoparticles.