The testing and rapid detection of pathogenic organisms is a crucial protocol in the prevention and identification of crises related to health, safety and wellbeing. Pathogen detection has become one ...of the most challenging aspects in the food and water industries, because of the rapid spread of waterborne and foodborne diseases in the community and at significant costs. With the prospect of inevitable population growth, and an influx of tourism to certain water bodies testing will become a requirement to control and prevent possible outbreaks of potentially fatal illnesses. The legislation is already particularly rigorous in the food industry, where failure to detect pathogenic materials represents a catastrophic event, particularly for the elderly, very young or immune-compromised population types. In spite of the need and requirement for rapid analytical testing, conventional and standard bacterial detection assays may take up to seven days to yield a result. Given the advent of new technologies, biosensors, chemical knowledge and miniaturisation of instrumentation this timescale is not acceptable. This review presents an opportunity to fill a knowledge gap for an extremely important research area; discussing the main techniques, biology, chemistry, miniaturisation, sensing and the emerging state-of-the-art research and developments for detection of pathogens in food, water, blood and faecal samples.
Antibiotics are compounds that have a particular mode of action upon the microorganism they are targeting. However, discovering and developing new antibiotics is a challenging and timely process. ...Antibiotic development process can take up to 10-15 years and over $1billion to develop a single new therapeutic product. Rapid screening tools to understand the mode of action of the new antimicrobial agent are considered one of the main bottle necks in the antimicrobial agent development process. Classical approaches require multifarious microbiological methods and they do not capture important biochemical and organism therapeutic-interaction mechanisms. This work aims to provide a rapid antibiotic-antimicrobial biochemical diagnostic tool to reduce the timeframes of therapeutic development, while also generating new biochemical insight into an antimicrobial-therapeutic screening assay in a complex matrix. The work evaluates the effect of antimicrobial action through "traditional" microbiological analysis techniques with a high-throughput rapid analysis method using UV-VIS spectroscopy and chemometrics. Bacteriostatic activity from tetracycline and bactericidal activity from amoxicillin were evaluated on a system using non-resistant
O157:H7 by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and UV-VIS spectroscopy (high-throughput analysis). The data were analysed using principal component analysis (PCA) and support vector machine (SVM) classification. The rapid diagnostic technique could easily identify differences between bacteriostatic and bactericidal mechanisms and was considerably quicker than the "traditional" methods tested.
The increasing desire to control quality in foods in real-time (e.g. on-line, at line, market) demands the development of innovative and easy to use analytical systems e.g. a combination of sensors ...with multivariate data analysis (MVA). It has been long established that the ability to analyse complex chemical samples such as foods is now essential to achieve the consistent quality demanded by consumers, to ensure uniformity and consistency within a brand and even to avoid fraud, which can have direct implications when it comes to food integrity. It is well known that a broad range of factors (e.g. chemical, physical properties) contribute to the sensory characteristics of foods (e.g. smell, taste and colour) including the origin of raw materials and processing steps. In such complex matrices the use of sensor systems combined with MVA (chemometrics) is especially promising as tools for an encompassing analysis and understanding of these contributing factors.
This article reviews recent applications of near infrared sensors (conventional and functional spectroscopy) for the measurement, monitoring and prediction of aroma and taste in several food matrices.
•Sensory properties of foods are very important to determine food quality.•Rapid analytical methods based in spectroscopy are currently used by the food industry.•The measurement and prediction of sensory parameters using NIR is discussed.
The creation of new materials is one of the fundamental driving forces between research and industry and lays the foundation for new products to enhance health and well being for the future. ...Antibacterial materials are an active area of research but also an economic sector in full expansion that addresses many application domains. It is also a world priority in terms of reducing infection in humans for improved life and well being. Healthcare is one the largest and most rapidly expanding needs of modern society, and smart approaches and materials are required to extend the boundaries required to improve the field. In this paper, we systematically review a series of biomaterials and strategies that have emerged over the last decade. In particular, focus has been driven around the nanorealm. Some of the diverse arenas surrounding the nanodomain and applications include drug screening technologies, biocompatibility, emerging approaches and biomimetics. In a wider front, intelligent materials are where the next phases of research are driven, some of which are discussed herein.
The physicochemical properties of nanoparticles and biomaterials exert influences over their interactions with cells and consequently play an important role when introduced into any given system. ...Characterisation of these said materials is a detailed and, above all, a cross-disciplinary relationship of physical, chemical, mechanical, surface, in vitro and in vivo multi-integrated research topics. The biocompatibility of a functional structure with desired properties is affected by the biomaterials' structural characteristics and building block pathways. Moreover, the sensitivity, depth of field, resolution and dimension of a given material also make structural analysis of a nano-biomaterial particularly challenging to characterise. In this paper, we discuss the use of biomaterial characterisation techniques (fluorescent and optical) to characterise structural aspects of biomaterials, with the aim of improving both the understanding and relationship between a biomaterials' structure and its functionality.
A strontium-doped hardystonite (Sr-HT) bioceramic, in bulk form, demonstrates excellent bioactivity for bone regeneration with high fracture toughness and compressive strength. This work examines the ...antibacterial and mechanical properties of Sr-HT coatings on an alpha-beta titanium alloy with a high specific strength and excellent corrosion resistance (Ti-6Al-4V) produced by atmospheric plasma spray (APS) as the deposition coating technique. A hydroxyapatite (HAp) APS coating, a commercial bioceramic coating, is chosen as the control. The in-situ observation showed that Sr-HT powders experience temperatures during plasma processing that exceeded their melting point to form a coating well adhered to the substrate. It was demonstrated that the Sr-HT coating possessed superior antibacterial properties against Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Pseudomonas aeruginosa. In addition, the Sr-HT coating exhibits a uniform distribution of hardness and elastic moduli, higher nanohardness and elastic moduli compared to the equivalent properties of the HAp coating. Moreover, the Sr-HT coating outperforms the HAp coating regarding scratch and wear resistance. The bonding and shear strength of the Sr-HT coating are higher than the values required for orthopedic implant coatings. The Sr-HT coating also allows efficient zinc, silicon and strontium ions release when immersed in cell culture media. In summary, the antibacterial capabilities and the mechanical properties of the Sr-HT APS coating exceed those of the commercial HAp APS coating. Therefore, Sr-HT APS coatings are candidates for bioceramic coating applications in orthopedic implants.
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•Sr-HT coating produced with APS presented improvements in mechanical properties.•Sr-HT coating exhibited a higher and more homogeneous elastic modulus and hardness.•Sr-HT coating exhibited better local scratch and wear resistance compared to HAp.•Under static tensile and static shear tests, the Sr-HT outperformed HAp coatings.•Sr-HT coating show antibacterial properties against MRSA and P. aeruginosa strains.
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.
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/m
·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.
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.
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.
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•Polymer contamination has reached a breaking point.•Contamination has now been observed in the Earth's most remote oceans.•Macro and micro plastics have been discussed comprehensively.•Nanoplastics are an overlooked issue, this review focuses on nanoplastics.•Sources, breakdown, fates, uptake, and characterisation will be discussed.
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