Covering: up to 2015
Over the last decade, the number of studies reporting the use of electrospray ionization mass spectrometry (ESI-MS) in combination with collision cells (or other activation ...methods) to promote fragmentation of synthetic and natural products for structural elucidation purposes has considerably increased. However, the lack of a systematic compilation of the gas-phase fragmentation reactions subjected to ESI-MS/MS conditions still represents a challenge and has led to many misunderstood results in the literature. This review article exploits the most common fragmentation reactions for ions generated by ESI in positive and negative modes using collision cells in an effort to stimulate the use of this technique by non-specialists, undergraduate students and researchers in related areas.
This review article explores the most common fragmentation reactions for ions generated by ESI in positive and negative modes.
L’article tente d’appliquer la notion de transfert culturel à deux études de cas en lien avec la région du Minho (Portugal), celui du retable de la chapelle des reliques de l’ancienne église ...bénédictine de Rio de Janeiro et celui du retable principal de l’église bénédictine d’Olinda. La critique n’a que ponctuellement associé ces retables respectivement à André Soares (1720-1769) et au frère José Vilaça (1731-1809), les deux noms les plus connus de l’art minhote, et hésite sur leurs répercussions brésiliennes. Mais le commanditaire du premier de ces retables en avait déjà financé un autre pour la chapelle privée qu’il possédait dans le Minho, et le second appartient au réseau bénédictin, au sein duquel le moine artiste a pu développer son art. Il s’agit donc de comprendre, à la lumière de ces exemples, à la fois en quoi la méthode des transferts culturels est applicable et ce qu’elle peut apporter à la lecture de ces œuvres, tout en interrogeant sa dépendance par rapport à des méthodes plus traditionnelles de l’histoire de l’art.
Fucoxanthin is a pigment present in diverse marine organisms such as micro and macro-algae. The most relevant source of fucoxanthin has been described to be the group of the brown macroalgae, also ...known as Phaeophyceae. The presence of the fucoxanthin, a xanthophyll, found as an accessory pigment in the chloroplasts of the brown algae is responsible for providing them their characteristic color. The market size of this carotenoid, expected to reach US$ 120 million by 2022, reflects its industrial importance, especially remarkable as a food or cosmetic ingredient.
Therefore, it is critical to recognize the main sources of fucoxanthin as well as the most efficient extraction and purification methods that allow obtaining the best production ratio for such a valuable molecule. Throughout this review very different preventive properties of the fucoxanthin have been included, such as antioxidant, anticancer, antiangiogenic, anti-inflammatory, cytoprotective, antiobesity, neuroprotective and its skin protective effects. The stability, bioavailability and toxicity of the fucoxanthin have also been reviewed through diverse biological, in vitro and in vivo assays.
Thus, the main aim of this work is to provide a wide and global vision of the fucoxanthin in terms of productive species, efficient recovery techniques and multiple industrial applications.
The main sources of fucoxanthin are brown algae (Phaeophytes) and some microalgae. Several techniques have been employed to extract this compound, such as maceration extraction (ME), enzyme assisted extraction (EAE), microwave assisted extraction (MAE), pressurized liquid extraction (PLE) or supercritical fluid extraction (SFE). Following the extraction, the identification step has been carried out using different chromatographic and spectroscopic techniques. Fucoxanthin has gained attention in the last decades, due to the wide variety of attributed beneficial activities, such as antioxidant, anti-inflammatory, anticancer or neuroprotective effects. These bioactivities are interesting for its diverse applications in the industry, including the development of innovative pharmaceutical, cosmetic and food products. Display omitted
•Review of fucoxanthin main matrixes and bioactive properties.•Approximation to fucoxanthin extraction and quantification methods.•Review of fucoxanthin stability, bioavailability and toxicity in diverse biological assays.•Content of fucoxanthin in micro and macroalgae (notably in chloroplasts of brown algae).•Fucoxanthin industrial importance (US$ 120 million by 2022) as ingredient (food or cosmetic).
Introduction
Antipsychotics are frequently used for managing psychiatric and behavioral symptoms of dementia. However, it’s an off-label resource which remains controversial due to significant safety ...concerns in the elderly population, namely increasing cardiovascular adverse effects.
Objectives
To access antipsychotic safety and potential risks when used in dementia.
Methods
A non-systematic review was carefully conducted on PubMed using the following keywords: “dementia”, “antipsychotics” and “safety.” We selected clinical trials, meta-analysis, randomized controlled trials published in the last 10 years.
Results
A total of 43 articles was obtained, of which 22 were excluded because they didn’t meet our inclusion criteria. Regarding atypical antipsychotics, one study found an incidence of severe events in 23,7% of patients and a OR=2.5 for cerebrovascular side effects. Quetiapine was suspended midway given it had a higher incidence of adverse effects compared to others. There weren’t any significant statistic differences concerning serious events between classes of antipsychotics(p<0,01). No study was found comparing typical and atypical antipsychotics safety in dementia.
Conclusions
Overall, we can conclude that antipsychotics pose a risk of serious adverse effects when used in elderly patients, namely cerebrovascular events. Among atypical antipsychotics, quetiapine, used frequently for controlling neuropsychiatric symptoms in these patients appears a higher risk for severe adverse events compared with other drugs. Their use should be restricted after there aren’t any other options available. New protocols could be developed to control these symptoms, for example, environmental measures before resorting to antipsychotics.
Mitochondria are controlled by the coordination of two genomes: the mitochondrial and the nuclear DNA. As such, variations in nuclear gene expression as a consequence of mutations and epigenetic ...modifications can affect mitochondrial functionality. Conversely, the opposite could also be true. However, the relationship between mitochondrial dysfunction and epigenetics, such as nuclear DNA methylation, remains largely unexplored. Mitochondria function as central metabolic hubs controlling some of the main substrates involved in nuclear DNA methylation, via the one carbon metabolism, the tricarboxylic acid cycle and the methionine pathway. Here, we review key findings and highlight new areas of focus, with the ultimate goal of getting one step closer to understanding the genomic effects of mitochondrial dysfunction on nuclear epigenetic landscapes.
•Algae constitute a source of phenolic compounds, which show bioactive properties.•Extraction process is critical for phenolic compounds’ conservation and stability.•Phenolics show bioactivities such ...as antioxidant, antitumoral or antimicrobial.•Phenolics from algae can be applied as natural ingredients in different industries.•Further research about structure–activity relationships is required.
Given the growing tendency of consumers to choose products with natural ingredients, food industries have directed scientific research in this direction. In this regard, algae are an attractive option for the research, since they can synthesize a group of secondary metabolites, called phenolic compounds, associated with really promising properties and bioactivities. The objective of this work was to classify the major phenolic compounds, compare the effectiveness of the different extractive techniques used for their extraction, from traditional systems (like heat assisted extraction) to the most advance ones (such as ultrasound, microwave or supercritical fluid extraction); the available methods for identification and quantification; the stability of the enriched extract in phenolic compounds and the main bioactivities described for these secondary metabolites, to offer an overview of the situation to consider if it is possible and/or convenient an orientation of phenolic compounds from algae towards an industrial application.
An important feature of fertilization is the asymmetric inheritance of centrioles. In most species it is the sperm that contributes the initial centriole, which builds the first centrosome that is ...essential for early development. However, given that centrioles are thought to be exceptionally stable structures, the mechanism behind centriole disappearance in the female germ line remains elusive and paradoxical. We elucidated a program for centriole maintenance in fruit flies, led by Polo kinase and the pericentriolar matrix (PCM): The PCM is down-regulated in the female germ line during oogenesis, which results in centriole loss. Perturbing this program prevents centriole loss, leading to abnormal meiotic and mitotic divisions, and thus to female sterility. This mechanism challenges the view that centrioles are intrinsically stable structures and reveals general functions for Polo kinase and the PCM in centriole maintenance. We propose that regulation of this maintenance program is essential for successful sexual reproduction and defines centriole life span in different tissues in homeostasis and disease, thereby shaping the cytoskeleton.
ABSTRACT
We present the identification and photometric analysis of 30 new low mass ratio (LMR) totally eclipsing contact binaries found in Catalina Sky Survey data. The LMR candidates are identified ...using Fourier coefficients and visual inspection. We perform a detailed scan in the parameter plane of mass ratio (q) versus inclination (i) using phoebe
-0.31 scripter to derive the best (q, i) pair for the initial models. The relative physical parameters are determined from the final model of each system. A Monte Carlo approach was adopted to derive the parameter errors. The resulting parameters confirm the identification. The approximate absolute physical parameters of the systems are estimated based on the light-curve solutions and Gaia Early Data Release 3 distances. 12 out of 30 new systems have fill-out factors $f\gt 50{{\ \rm per\ cent}}$ and q ≤ 0.25 (deep contact LMR systems), and eight of them, to within errors, are extreme LMR deep systems with q ≤ 0.1. We discuss the evolutionary status of the 30 LMR systems in comparison with the most updated catalogue of LMR systems from the literature. The scenario of the LMR systems as pre-merger candidates forming fast rotating stars is investigated for all systems, new and old, based both on Hut’s stability criteria and critical instability mass ratio (qinst) relation. CSS$\_$J075848.2+125656, with q/qinst = 1.23 ± 0.23, and CSS$\_$J093010.1−021624, with q/qinst = 1.25 ± 0.23, can be considered as merger candidates.
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