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A Critical Comparison of the Advanced Extraction Techniques Applied to Obtain Health-Promoting Compounds from Seaweeds
Marine macroalgae are rich in bioactive compounds that can be applied in several fields, mainly food, cosmetics, and medicine. The health-promoting effects of bioactive compounds, such as polyphenols, polysaccharides, carotenoids, proteins, and fatty acids, have been increasingly explored, especially regarding their antioxidant activity and improvement in human health. To extract these valuable compounds, advanced technologies that include Supercritical-Fluid Extraction (SFE), Pressurised-Liquid Extraction (PLE), Ultrasound-Assisted Extraction (UAE), Microwave-Assisted Extraction (MAE), Enzyme-Assisted Extraction (EAE), Ultrasound-Microwave-Assisted Extraction (UMAE) and Liquefied Gas Extraction (LGE) have been assessed due to their notable advantages over the conventional methods (Solid–Liquid and Soxhlet extraction). These advanced techniques are considerably influenced by different extraction parameters such as temperature, pressure, type of solvent, extraction time, solvent:solid material ratio, power (MAE, UAE, and UMAE), enzymes used (EAE), and factors related to the macroalgae matrix itself. Optimizing these process parameters for each method is critical to obtain better efficiency results for the targeted bioactive compounds. Macroalgae are natural sources with undeniable beneficial effects on human health. In this context, optimising the extraction techniques discussed in this review should prioritise exploiting these valuable resources’ wide range of bioactive properties.
Journal Article
The smile stealers : the fine + foul art of dentistry
This achingly jawdropping book follows the evolution of dentistry throughout the world from the Bronze Age to the present day, presenting captivating and grim illustrations of the tools and techniques of dentistry through the ages. Organized chronologically, The Smile Stealers interleaves beautiful and gruesome technical illustrations and paintings from the Wellcome Collection's unique archive of material from Europe, America and the Far East with seven authoritative and eloquent themed articles from medical historian Richard Barnett. A comprehensive review of the development of the trade and discipline of dentistry, it covers topics as diverse as the very first dentures (produced by the Etruscans in the seventh century bce); the smile revolution in 18th-century portraiture; and the role of dentistry in forensic science - all in one beautifully illustrated volume. Extending the cult of the medically macabre begun by its predecessors The Sick Rose and Crucial Interventions, The Smile Stealers is guaranteed to appeal to lovers of the horrific and the beautiful alike as it probes the growth of dentistry - from pulling out bad teeth to reconstructing jaws, and from painful action to pain-free interventions and the pursuit of the perfect smile.
Book
Femtosecond laser-assisted versus phacoemulsification cataract surgery (FEMCAT): a multicentre participant-masked randomised superiority and cost-effectiveness trial
Cataract surgery is one of the most common operations in health care. Femtosecond laser-assisted cataract surgery (FLACS) enables more precise ocular incisions and lens fragmentation than does phacoemulsification cataract surgery (PCS). We hypothesised that FLACS might improve outcomes in cataract surgery compared with PCS despite having higher costs.
We did a participant-masked randomised superiority clinical trial comparing FLACS and PCS in two parallel groups (permuted block randomisation stratified on centres via a centralised web-based application, allocation ratio 1:1, block size of 2 or 4 for unilateral cases and 2 or 6 for bilateral cases). Five French University Hospitals enrolled consecutive patients aged 22 years or older who were eligible for unilateral or bilateral cataract surgery. Participants, outcome assessors, and technicians carrying out examinations were masked to the surgical treatment allocation until the last follow-up visit and a sham laser procedure was set up for participants randomly assigned to the PCS arm. The primary clinical endpoint was the success rate of surgery, defined as a composite of four outcomes at a 3-month postoperative visit: absence of severe perioperative complication, a best-corrected visual acuity (BCVA) of 0·0 LogMAR (logarithm of the minimum angle of resolution) or better, an absolute refractive error of 0·75 dioptres or less, and unchanged postoperative corneal astigmatism power (≤0·5 dioptres) and axis (≤20°). The primary economic endpoint was the incremental cost per additional patient who had treatment success at 3 months. Primary outcomes were assessed in all randomly assigned patients who met all eligibility criteria (missing data considered as failure). We used mixed logistic regression models or mixed linear regression models for statistical comparisons, adjusted on centres and whether cataract surgery was bilateral or unilateral. The study is registered with ClinicalTrials.gov, NCT01982006.
Of the 907 patients (1476 eyes) randomly assigned between Oct 9, 2013, and Oct 30, 2015, 870 (704 eyes in FLACS group and 685 eyes in the PCS group) were analysed. We identified no significant difference in the success rate of surgery between the FLACS and PCS groups (FLACS: 41·1% [289 eyes]; PCS: 43·6% [299 eyes]); adjusted odds ratio 0·85, 95% CI 0·64–1·12, p=0·250). The incremental cost-effectiveness ratio was €10 703 saved per additional patient who had treatment success with PCS compared with FLACS. We observed no severe adverse events during the femtosecond laser procedure, and most of the complications in the FLACS group related to the primary outcome measures occurred during the phacoemulsification phase or postoperatively.
Despite its advanced technology, femtosecond laser was not superior to phacoemulsification in cataract surgery and, with higher costs, did not provide an additional benefit over phacoemulsification for patients or health-care systems.
French Ministry of Social Affairs and Health.
Journal Article
From landfill gas to energy : technologies and challenges
\"A comprehensive description of technologies available for converting old landfills to energy producers, and capturing the green house gases emitting from them. Its key assets are the case studies of successful landfill gas (LFG) recovery for energy projects around the world, and that it highlights why this has not been done in many more landfills around the world. Technical, financial, and social challenges facing the conversion of landfills to energy producers will be detailed, and solutions offered to either remine the landfill for recovering useful land (as is planned in dense urban areas of India) or close them properly while recovering the methane for energy use. Intended as a guide with background information and instructive tools to educate, guide and establish a basis for decision-making, technical feasibility assessment, economic assessment, and market evaluation of all aspects necessary for developing successful LFG management projects. \"-- Provided by publisher.
Book
Keyword extraction: Issues and methods
Due to the considerable growth of the volume of text documents on the Internet and in digital libraries, manual analysis of these documents is no longer feasible. Having efficient approaches to keyword extraction in order to retrieve the ‘key’ elements of the studied documents is now a necessity. Keyword extraction has been an active research field for many years, covering various applications in Text Mining, Information Retrieval, and Natural Language Processing, and meeting different requirements. However, it is not a unified domain of research. In spite of the existence of many approaches in the field, there is no single approach that effectively extracts keywords from different data sources. This shows the importance of having a comprehensive review, which discusses the complexity of the task and categorizes the main approaches of the field based on the features and methods of extraction that they use. This paper presents a general introduction to the field of keyword/keyphrase extraction. Unlike the existing surveys, different aspects of the problem along with the main challenges in the field are discussed. This mainly includes the unclear definition of ‘keyness’, complexities of targeting proper features for capturing desired keyness properties and selecting efficient extraction methods, and also the evaluation issues. By classifying a broad range of state-of-the-art approaches and analysing the benefits and drawbacks of different features and methods, we provide a clearer picture of them. This review is intended to help readers find their way around all the works related to keyword extraction and guide them in choosing or designing a method that is appropriate for the application they are targeting.
Journal Article
Recent Advances in Recovery of Lycopene from Tomato Waste: A Potent Antioxidant with Endless Benefits
Growing attention to environmental protection leads food industries to adopt a model of “circular economy” applying safe and sustainable technologies to recover, recycle and valorize by-products. Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized.
Journal Article
A Town Called Asbestos : Environmental Contamination, Health, and Resilience in a Resource Community
\"For decades, manufacturers from around the world relied on asbestos from the town of Asbestos, Quebec, to produce fire-retardant products. Then, over time, people learned about the mineral's devastating effects on human health. Dependent on this deadly industry for their community's survival, the residents of Asbestos developed a unique, place-based understanding of their local environment; the risks they faced living next to the giant opencast mine; and their place within the global resource trade. This book unearths the local/global tensions that defined Asbestos's proud and painful history to reveal the challenges similar resource communities have faced--and continue to face today.\"--Page 4 of cover.
Book
Effect of Temperatures on Polyphenols during Extraction
Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compounds are of great interest, as they have shown high antioxidant power and are correlated to many health benefits. Hence, traditional methods of extraction such as solvent extraction, Soxhlet extraction and novel extraction technologies such as ultrasound-assisted extraction and subcritical water extraction (SWE) have been investigated for the extraction of polyphenols. Scope and Approach: Generally, for traditional extractions, the total phenolic content (TPC) is highest at an extraction temperature of 60–80 °C. For this reason, polyphenols are regularly regarded as heat-labile compounds. However, in many studies that investigated the optimal temperature for subcritical water extraction (SWE), temperatures as high as 100–200 °C have been reported. These SWE extractions showed extremely high yields and antioxidant capacities at these temperatures. This paper aimed to examine the relevant literature to identify and understand the mechanisms behind this discrepancy. Results: Thermal degradation is the most common explanation for the degradation of polyphenols. This may be the case for specific or sub-groups of phenolic acids. The different extraction temperatures may have also impacted the types of polyphenols extracted. At high extraction temperatures, the formation of new compounds known as Maillard reaction products may also influence the extracted polyphenols. The selection of source material for extraction, i.e., the plant matrix, and the effect of extraction conditions, i.e., oxidation and light exposure, are also discussed. The overestimation of total phenolic content by the Folin–Ciocâlteu assay is also discussed. There is also a lack of consensus in TPC’s correlation to antioxidant activity.
Journal Article