2,896 research outputs found

    Effects of Dried Blood Spot Storage on Lipidomic Analysis

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    During the lipidomic analysis of red blood cell membranes, the distribution and percentage ratios of the fatty acids are measured. Since fatty acids are the key constituents of cell membranes, by evaluating their quantities it possible to understand the general health of the cells and to obtain health indicators of the whole organism. However, because the analysis is precise, it is necessary to ensure that the blood does not undergo significant variations between the point of collection and analysis. The composition of the blood may vary dramatically weeks after collection, hence, here an attempt is made to stabilize these complex matrixes using antioxidants deposited on the paper cards on which the blood itself is deposited

    Scavenging Effect of Various Extracts of the Gymnema sylvestre R. Br. and Antioxidant Activity of the Isolated Triterpenes

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    Gymnema sylvestre has been used in Asian traditional medicine for its anti-microbial, antihypercholesterolemic, hepatoprotective and sweet suppressing properties and activities. G. sylvestre has also been used extensively in chewing gum, as a health food for preventing obesity and diabetes, and as a tea. This study has evaluated the total phenolic content and antioxidant activity of the aqueous and organic G. sylvestre extracts and their sub-fractions for the initial characterization of the biological properties of the isolated compounds. An in vivo cell model was used to calculate the concentration inhibiting cell growth by 50% and the ability to exert antioxidant activity. All compounds inhibit cell growth in a dose-dependent manner, with an IC50 value ranging between 29 and 1462 μM. The effects on intracellular ROS levels are extremely variable, but it is of interest that some of the compounds appear to display an antioxidant effect

    Herbicidal potential of phenolic and cyanogenic glycoside compounds isolated from Mediterranean plants

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    This study was conducted to test five phenolic and cyanogenic glycoside compounds for growth regulating activity on the germination and seedling growth of Portulaca oleracea L., Amaranthus retroflexus L., and Lactuca sativa L. at different concentrations. Overall, the tested compounds revealed growth-regulating activity in species-specific and concentration dependent manner. The most powerful effects were much pronounced on seedling growth rather than on germination. In fact, the compounds 1 (amygdalin) and 2 (salicylic acid) were the most phytotoxic on root growth of  P. oleracea, and they caused, respectively, an inhibition of 55% and 85% at 10-6 M and 10-4 M. On the other hand, the lettuce seedling growth was more sensitive than weeds growth to the compounds 4 (3,4,5-trihydroxybenzoic acid) and 5 (7-hydroxycoumarin), which exhibited a moderate inhibition at the highest concentration. This selectivity and specificity of these active allelopathic compounds could be very useful for the development of new application of natural substances to control the aggressive weeds. Thus, our findings suggest that the integration of these compounds may maintain irrigation system and reduce the massive use of agrochemicals in agro-ecosystems

    A literature review of hypertensive retinopathy: systemic correlations and new technologies

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    OBJECTIVE: Hypertensive retinopathy (HR) is the most common ocular manifestation of systemic arterial hypertension. This paper aims to summarize the current knowledge of HR, reviewing its classical features, such as epidemiology, pathophysiology, clinical manifestations, classifications, management and the most significant systemic correlations. We also provide an update on the latest advances in new technologies focusing on novel instrumental classifications. MATERIALS AND METHODS: A literature search was performed to identify articles regarding HR listed in Embase, PubMed, Medline (Ovid) and Scopus database up to 1 December 2021. The reference lists of the analyzed articles were also considered a source of literature information. The following keywords were used in various combinations: hypertensive retinopathy, hypertension and eye, hypertensive retinopathy and systemic correlations, optical coherence tomography (OCT) and hypertensive retinopathy, optical coherence tomography angiography (OCTA) and hypertensive retinopathy, adaptive optics (AO) and hypertensive retinopathy. The authors analyzed all English articles found using the aforementioned Keywords. All the publications were thoroughly reviewed to create a detailed overview of this issue. RESULTS: HR signs have a significative association with cardiovascular, cerebrovascular and other systemic diseases. Patients with arteriosclerotic changes and, at the same time, severe HR, are at increased risk for coronary disease, peripheral vascular disease, stroke and dementia. HR is even now diagnosed and classified by its clinical appearance on a fundoscopic exam that is limited by interobserver variability. New technologies, like OCT, OCTA, AO and artificial intelligence may be used to develop a new instrumental classification that could become an objective and quantitative method for the evaluation of this disease. They could be useful to evaluate the subclinical retinal microvascular changes due to hypertension that may reflect the involvement of other vital organs. CONCLUSIONS: The eye is the only organ in the human body where changes in the blood vessels due to systemic hypertension can be studied in vivo. All doctors should be familiar with this disease because it has been largely demonstrated that signs of HR are correlated to patient’s health and mortality. Researchers should develop a new common, standardized, and objective method to assess hypertensive retinal changes; new technologies may have a significant role in this field. This review takes most of the literature published so far, including the OCTA studies in order to stimulate new points of reference to standardize parameters and new diagnostic markers of this disease

    The Lithium test for multiple populations in Globular Clusters: Lithium in NGC 2808

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    In the globular cluster NGC2808, a quasi-standard initial lithium abundance is derived for a red giant belonging to the `extreme' population, characterized by a large helium overabundance, and by abundances of proton capture elements typical of nuclear processing in gas at very high temperatures, where the initial lithium has been fully destroyed. The observations of lithium in such extreme cluster stars are important to test different models for the formation of multiple populations in old Globular Clusters. In the asymptotic giant branch (AGB) scenario, fresh lithium is synthetized during the initial phases of hot bottom burning which, afterwards, synthetize the other p-capture elements. We model the abundance of lithium in the ejecta of superAGB models, finding values consistent or larger than observed in the `extreme' giant; these same models describe correctly the magnesium depletion and silicon enrichment of the extreme population of NGC 2808, so the overall agreement provides further support to the AGB scenario. In the models involving massive or supermassive stars, the Lithium observed requires a mixture of the lithium-free ejecta of the polluting population with more than 40% of standard-lithium pristine gas. The extended chemical anomalies of NGC 2808 stars are then to be all explained within at most 60% of the possible dilution range, the initial helium mass fraction in the ejecta should be Y >= 0.5, to account for the Ye 0.38-0.40 of the extreme population, and further observations of p-process elements are needed to check the model.Comment: accepted for publication in The Astrophysical Journal Letter

    Montagne, comunità e lavoro tra 14. e 18. secolo

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    Il tema del volume è la definizione del rapporto tra comunità e lavoro in ambito alpino e prealpino. L’ambiente delle Alpi, infatti, ha determinato forme specifiche di organizzazione del lavoro e della proprietà, per esempio enfatizzando il ruolo della gestione collettiva dei beni fondiari, ma, al tempo stesso, l’organizzazione del lavoro ha modificato e connotato diversamente la vita delle comunità montane rispetto a quella delle comunità di pianura. Le aree alpine fornivano opportunità non sempre presenti altrove: attività di sfruttamento dei boschi e delle acque, di guida e di someggiatura legate ai passi e ai transiti di viaggiatori, erano solo alcuni degli ambiti di lavoro possibili in queste zone. I testi che il lettore troverà nel volume sono stati organizzati in cinque sezioni: la prima dedicata alle necessità collettive e alle risorse locali, la seconda all’organizzazione del lavoro, la terza agli scambi e al commercio, la quarta alle infrastrutture e, infine, in funzione comparativa e di confronto, una quinta sezione rivolta ad “altre montagne”

    Silymarin from Silybum marianum by Naviglio’s extractor: a new and very efficient approach

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    The aim of this work is to compare new and traditional extraction methods to obtain silymarin from Silybum marianum, a biennial herbaceous plant of the Asteraceae family, present throughout the Mediterranean basin and used to treat several diseases. Silymarin primarily contains flavonolignans and flavonoids and is used in some pharmaceutical preparations to improve of liver function and as a protective against some hepatotoxins. In six extracts obtained by new and traditional extraction methods, the total contents of silymarin and its main flavonolignans, total phenols and condensed tannins were evaluated in addition to their respective antioxidant capacities. By the Naviglio extractor, that is a rapid solid-liquid dynamic extraction method, it is possible to obtain a fraction quantitatively more abundant than other methods, and with a lower content of tannins and phenolic compounds but with a higher content of flavonolignans, rare and expensive, and therefore easier to separate and purify

    MWCNT/rGO/natural rubber latex dispersions for innovative, piezo‐resistive and cement‐based composite sensors

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    The present study is focused on the development and characterization of innovative cementitious-based composite sensors. In particular, multifunctional cement mortars with enhanced piezoresistive properties are realized by exploiting the concept of confinement of Multiwall Carbon Nanotubes (MWCNTs) and reduced Graphene Oxide (rGO) in a three-dimensional percolated network through the use of a natural-rubber latex aqueous dispersion. The manufactured cement-based composites were characterized by means of Inelastic Neutron Scattering to assess the hydration reactions and the interactions between natural rubber and the hydrated-cement phases and by Scanning Electron Microscopy and X-Ray diffraction to evaluate the morphological and mineralogical structure, respectively. Piezo-resistive properties to assess electro-mechanical behavior in strain condition are also measured. The results show that the presence of natural rubber latex allows to obtain a three-dimensional rGO/MWCNTs segregate structure which catalyzes the formation of hydrated phases of the cement and increases the piezo-resistive sensitivity of mortar composites, representing a reliable approach in developing innovative mortar-based piezoresistive strain sensors

    CAP2 dimerization regulates cofilin in synaptic plasticity and Alzheimer's disease

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    Abstract Regulation of actin cytoskeleton dynamics in dendritic spines is crucial for learning and memory formation. Hence, defects in the actin cytoskeleton pathways are a biological trait of several brain diseases, including Alzheimer's Disease. Here, we describe a novel synaptic mechanism governed by the cyclase-associated protein 2 (CAP2), which is required for structural plasticity phenomena and completely disrupted in Alzheimer's Disease. We report that the formation of CAP2 dimers through its Cys32 is important for CAP2 binding to cofilin and for actin turnover. The Cys32-dependent CAP2 homodimerization and association to cofilin are triggered by long-term potentiation and are required for long-term potentiation-induced cofilin translocation into spines, spine remodelling and the potentiation of synaptic transmission. This mechanism is specifically affected in the hippocampus, but not in the superior frontal gyrus, of both Alzheimer's Disease patients and APP/PS1 mice, where CAP2 is down-regulated and CAP2 dimer synaptic levels are reduced. Notably, CAP2 levels in the cerebrospinal fluid are significantly increased in Alzheimer's Disease patients but not in subjects affected by frontotemporal dementia. In Alzheimer's Disease hippocampi, cofilin association to CAP2 dimer/monomer is altered and cofilin is aberrantly localized in spines. Taken together, these results provide novel insights into structural plasticity mechanisms that are defective in Alzheimer's Disease
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