Combining Chemometrics and Sensors: Toward New Applications in Monitoring and Environmental Analysis.

For many years, an extensive array of chemometric methods have provided a platform upon which a quantitative description of environmental conditions can be obtained. Applying chemometric methods to environmental data allows us to identify and describe the interrelations between certain environmental drivers. They also provide an insight into the interrelationships between these drivers and afford us a greater understanding of the potential impact that these drivers can place upon the environment. However, an effective marriage of these two systems has not been performed. Therefore, it is the aim of this review to highlight the advantages of using chemometrics and sensors to identify hidden trends in environmental parameters, which allow the state of the environment to be effectively monitored. Despite the combination of chemometrics and sensors, to capture new developments and applications in the field of environmental sciences, these methods have not been extensively used. Importantly, although different parameters and monitoring procedures are required for different environments (e.g., air, water, soil), they are not distinct, separate entities. Contemporary developments in the use of chemometrics afford us the ability to predict changes in different aspects of the environment using instrumental methods. This review also provides an insight into the prevailing trends and the future of environmental sensing, highlighting that chemometrics can be used to enhance our ability to monitor the environment. This enhanced ability to monitor environmental conditions and to predict trends would be beneficial to government and research agencies in their ability to develop environmental policies and analysis procedures.

The Multiomics Analyses of Fecal Matrix and Its Significance to Coeliac Disease Gut Profiling.

Gastrointestinal (GIT) diseases have risen globally in recent years, and early detection of the host's gut microbiota, typically through fecal material, has become a crucial component for rapid diagnosis of such diseases. Human fecal material is a complex substance composed of undigested macromolecules and particles, and the processing of such matter is a challenge due to the unstable nature of its products and the complexity of the matrix. The identification of these products can be used as an indication for present and future diseases; however, many researchers focus on one variable or marker looking for specific biomarkers of disease. Therefore, the combination of genomics, transcriptomics, proteomics and metabonomics can give a detailed and complete insight into the gut environment. The proper sample collection, sample preparation and accurate analytical methods play a crucial role in generating precise microbial data and hypotheses in gut microbiome research, as well as multivariate data analysis in determining the gut microbiome functionality in regard to diseases. This review summarizes fecal sample protocols involved in profiling coeliac disease.

Analysis of Pathogenic Bacterial and Yeast Biofilms Using the Combination of Synchrotron ATR-FTIR Microspectroscopy and Chemometric Approaches.

Biofilms are assemblages of microbial cells, extracellular polymeric substances (EPS), and other components extracted from the environment in which they develop. Within biofilms, the spatial distribution of these components can vary. Here we present a fundamental characterization study to show differences between biofilms formed by Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative Pseudomonas aeruginosa, and the yeast-type Candida albicans using synchrotron macro attenuated total reflectance-Fourier transform infrared (ATR-FTIR) microspectroscopy. We were able to characterise the pathogenic biofilms' heterogeneous distribution, which is challenging to do using traditional techniques. Multivariate analyses revealed that the polysaccharides area (1200-950 cm-1) accounted for the most significant variance between biofilm samples, and other spectral regions corresponding to amides, lipids, and polysaccharides all contributed to sample variation. In general, this study will advance our understanding of microbial biofilms and serve as a model for future research on how to use synchrotron source ATR-FTIR microspectroscopy to analyse their variations and spatial arrangements.

Selenium nanoparticles in poultry feed modify gut microbiota and increase abundance of Faecalibacterium prausnitzii.

The poultry industry aims to improve productivity while maintaining the health and welfare of flocks. Pathogen control has been achieved through biosecurity, vaccinations and the use of antibiotics. However, the emergence of antibiotic resistance, in animal and human pathogens, has prompted researchers and chicken growers alike to seek alternative approaches. The use of new and emerging approaches to combat pathogen activity including nanotechnology, in particular, silver nanoparticles (NPs), has been found to not only eradicate pathogenic bacteria but also include issues of toxicity and bioaccumulation effects. Other novel metal nanoparticles could provide this pathogen reducing property with a more tailored and biocompatible nanomaterial for the model used, something our study represents. This study investigated the benefits of nanomaterial delivery mechanisms coupled with important health constituents using selenium as a biocompatible metal to minimise toxicity properties. Selenium NPs were compared to two common forms of bulk selenium macronutrients already used in the poultry industry. An intermediate concentration of selenium nanoparticles (0.9 mg/kg) demonstrated the best performance, improving the gut health by increasing the abundance of beneficial bacteria, such as Lactobacillus and Faecalibacterium, and short-chain fatty acids (SCFAs), in particular butyric acid. SCFAs are metabolites produced by the intestinal tract and are used as an energy source for colonic cells and other important bodily functions. Selenium nanoparticles had no significant effect on live weight gain or abundance of potentially pathogenic bacteria.

Poly(butylene adipate-co-terephthalate)/Polylactic Acid/Tetrapod-Zinc Oxide Whisker Composite Films with Antibacterial Properties.

Biodegradable composite films comprising of poly(butylene adipate-co-terephthalate) (PBAT), polylactic acid (PLA), and tetrapod-zinc oxide (T-ZnO) whisker were prepared by a melt-extrusion and blow molding process. The effect of the incorporation of the T-ZnO whisker (1 to 7 wt.%) in the PBAT/PLA blend film was studied systematically. The composite films with an optimal T-ZnO whisker concentration of 3 wt.% exhibited the highest mechanical (tensile strength ~32 MPa), rheological (complex viscosity~1200 Pa.s at 1 rad/s angular frequency), and gas barrier (oxygen permeability~20 cc/m2·day) properties, whereas the composite films with 7 wt.% T-ZnO whiskers exhibited the highest antibacterial properties. The developed composite films can find potential application as antibacterial food packaging materials.

Antifouling and Antimicrobial Study of Nanostructured Mixed-Matrix Membranes for Arsenic Filtration.

Membrane fouling is a major drawback in the membrane filtration industry for water treatment. Mixed-matrix membranes (MMMs) are well known for their enhanced antifouling and antibacterial properties, which could offer potential benefits for membrane filtration processes in the water treatment field. In this work, three electrospun nanofibrous MMMs (P, CP, and MCP, which were, respectively, the pristine polysulfone membrane and mixed-matrix membranes (MMMs) consisting of GO-ZnO and GO-ZnO-iron oxides) were studied for antifouling and antibacterial properties with respect to the arsenic nanofiltration process. The effects of these composites on the antifouling behaviour of the membranes were studied by characterising the bovine serum albumin (BSA) protein adsorption on the membranes and subsequent analysis using microscopic (morphology via scanning electron microscopy) and Brunauer-Emmett-Teller (BET) analyses. The antibacterial properties of these membranes were also studied against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The composite nanoparticle-incorporated membranes showed improved antifouling properties in comparison with the pristine polysulfone (PSF) membrane. The excellent antimicrobial properties of these membranes make them appropriate candidates to contribute to or overcome biofouling issues in water or wastewater treatment applications.

Application of Fluconazole-Loaded pH-Sensitive Lipid Nanoparticles for Enhanced Antifungal Therapy.

Cryptococcus neoformans is a yeast-like fungus that can cause the life-threatening disease cryptococcal meningitis. Numerous reports have shown increased resistance of this fungus against antifungal treatments, such as fluconazole (Fluc), contributing to an 80% global mortality rate. This work presents a novel approach to improve the delivery of the antifungal agent Fluc and increase the drug's targetability and availability at the infection site. Exploiting the acidic environment surrounding a C. neoformans infected site, we have developed pH-sensitive lipid nanoparticles (LNP) encapsulating Fluc to inhibit the growth of resistant C. neoformans. The LNP-Fluc delivery system consists of a neutral lipid monoolein (MO) and a novel synthetic ionizable lipid 2-morpholinoethyl oleate (O2ME). At neutral pH, because of the presence of O2ME, the nanoparticles are neutral and exhibit a liquid crystalline hexagonal nanostructure (hexosomes). At an acidic pH, they are positively charged with a cubic nanostructure (cubosomes), which facilitates the interaction with the negatively charged fungal cell wall. This interaction results in the MIC50 and MIC90 values of the LNP-Fluc being significantly lower than that of the free-Fluc control. Confocal laser scanning microscopy and scanning electron microscopy further support the MIC values, showing fungal cells exposed to LNP-Fluc at acidic pH were heavily distorted, demonstrating efflux of cytoplasmic molecules. In contrast, fungal cells exposed to Fluc alone showed cell walls mostly intact. This current study represents a significant advancement in delivering targeted antifungal therapy to combat fungal antimicrobial resistance.

Antibacterial Longevity of a Novel Gallium Liquid Metal/Hydroxyapatite Composite Coating Fabricated by Plasma Spray.

Hydroxyapatite (HAp)-coated metallic implants are known for their excellent bioactivity and osteoconductivity. However, infections associated with the microstructure of the HAp coatings may lead to implant failures as well as increased morbidity and mortality. This work addresses the concerns about infections by developing novel composite coatings of HAp and gallium liquid metal (GaLM) using atmospheric plasma spray (APS) as the coating technique. Five weight percent Ga was mixed into a commercially supplied HAp powder using an orbital shaker; then, the HAp-Ga particle feedstock was coated onto Ti6Al4V substrates using the APS technique. The X-ray diffraction results indicated that Ga did not form any Ga-related phases in either the HAp-Ga powder or the respective coating. The GaLM filled the pores of the HAp coating presented both on the top surface and within the coating, especially at voids and cracks, to prevent failures of the coating at these locations. The wettability of the surface was changed from hydrophobic for the HAp coating to hydrophilic for the HAp-Ga composite coating. Finally, the HAp-Ga coating presented excellent antibacterial efficacies against both initial attachments and established biofilms generated from methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa after 18 h and 7 days of incubation in comparison to the control HAp coating. This study shows that GaLM improves the antibacterial properties of HAp-based coatings without sacrificing the beneficial properties of conventional HAp coatings. Thus, the HAp-Ga APS coating is a viable candidate for antibacterial coatings.

The use of derivatives and chemometrics to interrogate the UV-Visible spectra of gin samples to monitor changes related to storage.

Extensive research has been carried out to study and characterise different properties of alcoholic beverages using spectroscopy methods. Although UV-VIS spectroscopy is being used for the routine analysis of several beverages and foods, it has not been extensively used as a high throughput method. The objective of this study was to evaluate the application of derivatives to interrogate the UV-VIS spectra of gin samples to monitor changes related with storage conditions. Samples were analysed using an UV-VIS (200-800 nm) spectrophotometer with 1 cm path length. The raw spectra, second, third and fourth derivatives were used to analyse and interpret the UV-VIS spectra related to storage conditions. The results of this study indicated that the use of derivatives (third and fourth) as pre-process method to the UV-VIS spectra of gin samples allowed for a better identification of wavelengths as well as interpretation of the spectra associated with the different storage conditions.

Nanoparticles of selenium as high bioavailable and non-toxic supplement alternatives for broiler chickens.

Selenium is commonly used in the poultry industry as an additive in broiler feed to improve immunity and overall health. The selenium comes in different forms, inorganic and organic selenium, as sodium selenite and selenomethionine, respectively. This study proposes the use of nanoparticles of selenium (nanoSe) for improved delivery and absorption of the trace element while causing no toxicity. Previous studies have shown the success in utilizing nanoSe in broiler feed, with increased absorption and diffusion of material into organs and tissues, and increased antioxidant capacity. However, the mechanism of nanoSe conversion remains unknown, and the gut microbiota is believed to play a significant role in the process. The use of inorganic selenium in poultry feed demonstrated a lower bioavailability in breast (P ≤ 0.01) and duodenum tissue (P ≤ 0.05), and increased accumulation in organs involved in detoxification processes as compared to organic selenium and selenium nanoparticle supplementation. Histopathological analysis showed that nanoSe did not cause any damaging effects to the tissues analysed, revealing intact epithelial cells in the digestive system and neuronal bodies in brain tissue. The results indicate that nanoparticles of selenium operate a similar way to organic selenium and could potentially be used in poultry feed as a trace element additive.

Nano-plastics and their analytical characterisation and fate in the marine environment: From source to sea.

Polymer contamination is a major pollutant in all waterways and a significant concern of the 21st Century, gaining extensive research, media, and public attention. The polymer pollution problem is so vast; plastics are now observed in some of the Earth's most remote regions such as the Mariana trench. These polymers enter the waterways, migrate, breakdown; albeit slowly, and then interact with the environment and the surrounding biodiversity. It is these biodiversity and ecosystem interactions that are causing the most nervousness, where health researchers have demonstrated that plastics have entered the human food chain, also showing that plastics are damaging organisms, animals, and plants. Many researchers have focused on reviewing the macro and micro-forms of these polymer contaminants, demonstrating a lack of scientific data and also a lack of investigation regarding nano-sized polymers. It is these nano-polymers that have the greatest potential to cause the most harm to our oceans, waterways, and wildlife. This review has been especially ruthless in discussing nano-sized polymers, their ability to interact with organisms, and the potential for these nano-polymers to cause environmental damage in the marine environment. This review details the breakdown of macro-, micro-, and nano-polymer contamination, examining the sources, the interactions, and the fates of all of these polymer sizes in the environment. The main focus of this review is to perform a comprehensive examination of the literature of the interaction of nanoplastics with organisms, soils, and waters; followed by the discussion of toxicological issues. A significant focus of the review is also on current analytical characterisation techniques for nanoplastics, which will enable researchers to develop protocols for nanopolymer analysis and enhance understanding of nanoplastics in the marine environment.

In vitro growth of gut microbiota with selenium nanoparticles.

The application of nanoparticles rose steeply in the last decade, where they have become a common ingredient used in processed human food, improving food properties such as shelf life and appearance. Nanoparticles have also attracted considerable interest to the livestock industry, due to their efficacy in intestinal pathogen control, with the regulatory and consumer driven push for the removal of antibiotic growth promoters. The influence of selenium (Se) nanoparticles was investigated on a diverse and mature broiler caecal microbiota using in vitro culturing and 16S rRNA gene sequencing methods for microbiota characterisation. Caecal microbiota was collected from 4 traditionally grown heritage roosters and grown for 48 h, in the presence and absence of Se nanoparticles, with 2 technical replicates each. The effect of rooster as a biological variable strongly overpowered the effects of nano-Se in the media, resulting in moderate effects on the structure and diversity of the caecal microbial community. However the nanoparticles showed a significant reduction (P < 0.05) in the abundance of an emerging poultry pathogen, Enterococcus cecorum identical operational taxonomic units (OTU), which could be of notable interest in poultry production for targeted E. cecorum control without significant disturbance to the total microbial community.

Oregano powder reduces Streptococcus and increases SCFA concentration in a mixed bacterial culture assay.

Food borne illnesses have a world-wide economic impact and industries are continuously developing technologies to reduce the spread of disease caused by microorganisms. Antimicrobial growth promoters (AGPs) have been used to decrease microbiological infections in animals and their potential transfer to humans. In recent years there has been a global trend to remove AGPs from animal feed in an attempt to reduce the spread of antimicrobial resistant genes into the human population. Phytobiotics, such as oregano powder, are one of the potential replacements for AGPs due to their well-established antimicrobial components. 16S rRNA gene amplicons were used to determine the effect of oregano powder (1% w/v) on the microbiota of mixed bacterial cell cultures, which were obtained from the ceca of traditionally grown meat chickens (broilers). Oregano powder had a mild effect on the microbial cell cultures increasing Enterococcus faecium, rearranging ratios of members in the genus Lactobacillus and significantly reducing the genus Streptococcus (p = 1.6e-3). Beneficial short chain fatty acids (SCFA), acetic and butyric acid, were also significantly increased in oregano powder supplemented cultures. These results suggest that oregano powder at a concentration of 1% (w/v) may have beneficial influences on mixed microbial communities and SCFA production.

From Academia to Reality Check: A Theoretical Framework on the Use of Chemometric in Food Sciences.

There is no doubt that the current knowledge in chemistry, biochemistry, biology, and mathematics have led to advances in our understanding about food and food systems. However, the so-called reductionist approach has dominated food research, hindering new developments and innovation in the field. In the last three decades, food science has moved into the digital and technological era, inducing several challenges resulting from the use of modern instrumental techniques, computing and algorithms incorporated to the exploration, mining, and description of data derived from this complexity. In this environment, food scientists need to be mindful of the issues (advantages and disadvantages) involved in the routine applications of chemometrics. The objective of this opinion paper is to give an overview of the key issues associated with the implementation of chemometrics in food research and development. Please note that specifics about the different methodologies and techniques are beyond the scope of this review.

Antibacterial Properties of Graphene Oxide-Copper Oxide Nanoparticle Nanocomposites.

The resistance of pathogenic bacteria toward traditional biocidal treatment methods is a growing concern in various settings, including that of water treatment and in the medical industry. As such, advanced antibacterial technologies are needed to prevent infections, against which current antibiotics are failing. This study introduces copper oxide nanoparticles (CuONPs) doped in graphene oxide (GO) as a potential pathogenic bacterial treatment. The aim of the study was to evaluate the antibacterial properties of the GO-CuONP hybridized material against pathogenic Escherichia coli ATCC 8739 (E. coli) and Salmonella typhimurium ATCC 14028 (S. typhimurium). GO was synthesized using a modified Hummer's method and doped with 40% w/w CuONPs using a series of thermal chemical reactions. The resulting hybrids were then characterized using scanning electron microscopic (SEM) and spectroscopic studies. These studies revealed that the hybrid material was considerably altered by the inclusion of CuONPs. The live and dead bacteria attached to the GO-CuONP material were detected using confocal laser scanning microscopy (CLSM). The antibacterial activity assay of the GO-CuONP material was conducted using a standard plate count method. Importantly, the GO-CuONP nanocomposite was determined to be an effective antibacterial nanomaterial, significantly inhibiting the growth of both E. coli and S. typhimurium bacteria compared to that observed on the pristine GO material. This study suggests that GO-CuONP composites are a promising high-efficacy antibacterial nanomaterial.

Ultrastructure of the gastro intestinal tract of healthy Japanese quail (Coturnix japonica) using light and scanning electron microscopy.

The Japanese quail (Coturnix japonica) are popular both as an alternative protein source and as a model of choice for scientific research in several disciplines. There is limited published information on the histological features of the intestinal tract of Japanese quail. The only comprehensive reference is a book published in 1969. This study aims to fill that niche by providing a reference of general histological features of the Japanese quail, covering all the main sections of the intestinal tract. Both light and scanning electron microscope (SEM) images are presented. Results showed that the Japanese quail intestinal tract is very similar to that of the chicken with the exception of the luminal koilin membrane of the gizzard. Scanning electron microscopic photomicrographs show that in the Japanese quail koilin vertical rods are tightly packed together in a uniform manner making a carpet-like appearance. This differs in chicken where the conformations of vertical rods are arranged in clusters.

Biomimetics for early stage biofouling prevention: templates from insect cuticles.

A biomimetic antifouling material study was carried out utilising superhydrophobic cicada and dragonfly wings replicated with a polymer (epoxy resin). They were tested in a marine biofouling study for up to 1 week in addition to biofouling assays of protein, carbohydrate and DNA absorption. The materials were compared against a commercial antifouling paint and a polymeric smooth surface constituting a control sample. The replicated surfaces demonstrated superior antifouling properties in comparison to the control and similar efficiency in DNA (10% reduction), protein and carbohydrate adsorption (15%) to the commercial anti-fouling paint. As the fabricated surfaces have roughness at the nanometre scale it is probable that the low adsorption properties, at least in the early stages, may be related to air trapped at the surface. Interestingly the most disordered replicated surface (dragonfly wing replicate) demonstrated the lowest values of absorption.