Automatic image registration (AIR) is still a present challenge for the remote sensing community. Although a wide variety of AIR methods have been proposed in the last few years, there are several drawbacks which avoid their common use in practice. The recently proposed scale invariant feature transform (SIFT) approach has already revealed to be a powerful tool for the obtention of tie points in general image processing tasks, but it has a limited performance when directly applied to remote sensing images. In this paper, a new AIR method is proposed, based on the combination of image segmentation and SIFT, complemented by a robust procedure of outlier removal. This combination allows for an accurate obtention of tie points for a pair of remote sensing images, being a powerful scheme for AIR. Both synthetic and real data have been considered in this work for the evaluation of the proposed methodology, comprising medium and high spatial resolution images, and single-band, multispectral, and hyperspectral images. A set of measures which allow for an objective evaluation of the geometric correction process quality has been used. The proposed methodology allows for a fully automatic registration of pairs of remote sensing images, leading to a subpixel accuracy for the whole considered data set. Furthermore, it is able to account for differences in spectral content, rotation, scale, translation, different viewpoint, and change in illumination. Index Terms-Automatic image registration (AIR), image segmentation, optical images, scale invariant feature transform (SIFT).
Experimental studies have provided convincing evidence that food bioactive compounds (FBCs) have a positive biological impact on human health, exerting protective effects against non-communicable diseases (NCD) including cancer and cardiovascular (CVDs), metabolic, and neurodegenerative disorders (NDDs). These benefits have been associated with the presence of secondary metabolites, namely polyphenols, glucosinolates, carotenoids, terpenoids, alkaloids, saponins, vitamins, and fibres, among others, derived from their antioxidant, antiatherogenic, anti-inflammatory, antimicrobial, antithrombotic, cardioprotective, and vasodilator properties. Polyphenols as one of the most abundant classes of bioactive compounds present in plant-based foods emerge as a promising approach for the development of efficacious preventive agents against NCDs with reduced side effects. The aim of this review is to present comprehensive and deep insights into the potential of polyphenols, from their chemical structure classification and biosynthesis to preventive effects on NCDs, namely cancer, CVDs, and NDDS. The challenge of polyphenols bioavailability and bioaccessibility will be explored in addition to useful industrial and environmental applications. Advanced and emerging extraction techniques will be highlighted and the high-resolution analytical techniques used for FBCs characterization, identification, and quantification will be considered.
In the last decade, several developments, particularly in the liquid chromatography and hyphenated techniques fields, have allowed researchers to reach analytical limits that are becoming very close to the single molecule level. Sample preparation, however, despite being a key step in the analytical methodology, did not track these developments and very few approaches able to cope with these stringent analytical requirements were developed. One such approach is microextraction by packed sorbent (MEPS), a sophisticated and miniaturized form of solid phase extraction that has reduced to the microliter scale every step of the sample extraction methodology including sample volume and solvent usage. Simultaneously, the amount of extraction phase used was also reduced and, more importantly, the sorbent is reusable dozens of times which significantly lowers the cost of analysis versus other solid-phase extraction approaches. In this review, we will update the state-of-the-art of the MEPS technique, focusing on the trends and applications reported since 2010 and future perspectives and developments that in our view will further improve the high-throughput potential and applications of this sample preparation methodology. KeywordsMicroextraction by packed sorbent (MEPS) • eVol • Sample preparation • Solid phase extraction (SPE) © 2013 J. Pereira et al., licensee Versita Sp. z o. o. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs license, which means that the text may be used for non-commercial purposes, provided credit is given to the author Unauthenticated Download Date | 12/26/14 1:57 PM Microextraction using packed sorbent as an effective and high-throughput sample extraction technique: Recent applications and future trends. Unauthenticated Download Date | 12/26/14 1:57 PM J. Pereira et al. 40 Unauthenticated Download Date | 12/26/14 1:57 PM Microextraction using packed sorbent as an effective and high-throughput sample extraction technique: Recent applications and future trends. Unauthenticated Download Date | 12/26/14 1:57 PM Microextraction using packed sorbent as an effective and high-throughput sample extraction technique: Recent applications and future trends.
The word "cannabinoid" refers to every chemical substance, regardless of structure or origin, that joins the cannabinoid receptors of the body and brain and that have similar effects to those produced by the Cannabis plant and based on their source of production, cannabinoids can be classified into endocannabinoids, phytocannabinoids and synthetic cannabinoids. Synthetic cannabinoids represent the largest class of drugs detected through the EU Early Warning System with a total of 190 substances notified from 2008 to 2018 and about 280 have been reported worldwide to the United Nations Office on Drugs and Crime. Sprayed on natural herb mixtures with the aim to mimic the euphoria effect of cannabis and sold as "herbal smoking blends" or "herbal incense" under brand names like "Spice" or "K2", synthetic cannabinoids are available from websites for the combination with herbal materials or more recently, for the use in e-cigarettes. Currently labeled as "not for human consumption" to circumvent legislation, their legal status varies by country with many government institutions currently pushing for their control. However, due to the emergence of new substances, it requires a constant update of the list of controlled drugs. Little is known about how these substances work and their toxic effects in humans and the same product could vary not only in the amount and in the type of substance added. In the last years, synthetic cannabinoids have been associated with deaths and acute intoxications in Europe and, despite a range of new measures introduced in this area, continue to represent a challenge to current drug policy models. These synthetic substances are much more potent than natural cannabis, as well as displayed greater efficacy, acting as full agonists at the cannabinoid receptors. It is possible that, along with being highly potent, some may also have long half-lives, potentially leading to a prolonged psychoactive effect. The present work provides a review on existing literature about the development of synthetic cannabinoids as substances of abuse, current patterns of abuse and their legal status, chemical classification, and some pharmacological and toxicological properties.
Headspace solid-phase microextraction combined with mass spectrometry as a powerful analytical tool for profiling the terpenoid metabolomic pattern of hop-essential oil derived from Saaz variety Hop (Humulus lupulus L., Cannabaceae family) is prized for its essential oil contents, used in beer production and, more recently, in biological and pharmacological applications. In this work, a method involving headspace solid-phase microextraction and gas chromatographymass spectrometry was developed and optimized to establish the terpenoid (monoterpenes and sesquiterpenes) metabolomic pattern of hop-essential oil derived from Saaz variety as a mean to explore this matrix as a powerful biological source for newer, more selective, biodegradable and naturally produced antimicrobial and antioxidant compounds. Different parameters affecting terpenoid metabolites extraction by headspace solid-phase microextraction were considered and optimized: type of fiber coatings, extraction temperature, extraction time, ionic strength, and sample agitation. In the optimized method, analytes were extracted for 30 min at 40ЊC in the sample headspace with a 50/30 m divinylbenzene/carboxen/polydimethylsiloxane coating fiber. The methodology allowed the identification of a total of 27 terpenoid metabolites, representing 92.5% of the total Saaz hop-essential oil volatile terpenoid composition. The headspace composition was dominated by monoterpenes (56.1%, 13 compounds), sesquiterpenes (34.9%, 10), oxygenated monoterpenes (1.41%, 3), and hemiterpenes (0.04%, 1) some of which can probably contribute to the hop of Saaz variety aroma. Mass spectrometry analysis revealed that the main metabolites are the monoterpene -myrcene (53.0 ± 1.1% of the total volatile fraction), and the cyclic sesquiterpenes, ␣-humulene (16.6 ± 0.8%), and -caryophyllene (14.7 ± 0.4%), which together represent about 80% of the total volatile fraction from the hop-essential oil. These findings suggest that this matrix can be explored as a powerful biosource of terpenoid metabolites. Keywords: Essential oil / GC-qMS / HopSaaz variety / HS-SPME / Terpenoid metabolites DOI 10.1002/jssc.201200244 IntroductionIt is well known that plant-derived natural products are extensively used as biologically active compounds. From these, the essential oils, which represent a small fraction of a plant's composition, and some of their constituents are used not only in pharmaceutical products for their therapeutic activities but also in agriculture, as food preservers and additives for human or animal use, in cosmetics and perfumes, and other industrial fields [1,2]. Particular emphasis has been Correspondence: Professor José S. Câmara, Centro de Ciências Exactas e da Engenharia, Universidade da Madeira, Campus Universitário da Penteada, 9000-390 Funchal, Portugal E-mail: jsc@uma.pt Fax: +351-291705149Abbreviations: HS-SPME, headspace solid phase microextraction; RI, retention index placed on their antibacterial, antifungal, and insecticidal activities [3]. In many cases, they serve as (i)...
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