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31.
Emanuele Ferrari Mireille Engelen Enrico Monzani Michela Sturini Stefania Girotto Luigi Bubacco Luigi Zecca Luigi Casella 《Journal of biological inorganic chemistry》2013,18(1):81-93
Elucidating the structure and biosynthesis of neuromelanin (NM) would be an important step towards understanding its putative role in the pathogenesis of Parkinson’s disease. A useful complement to studies aimed at unraveling the origin and properties of this essentially insoluble natural substance is the preparation of synthetic derivatives that resemble NM. With this aim in mind, water-soluble conjugates between dopamine-derived melanin and bovine serum albumin (BSA) were synthesized. Melanin–BSA adducts were prepared with both eumelanic oligomers obtained through the oxidative polymerization of dopamine and pheomelanic oligomers obtained under the same conditions from dopamine and cysteine. Iron ions were added during the synthesis to understand the interaction between the pigment and this metal ion, as the NM in neurons in several human brain regions contains significant amounts of iron. The structures of the conjugates were analyzed by 1H NMR spectroscopy and controlled proteolysis/MS experiments. The binding of iron(III) ions was evaluated by ICP analysis and EPR spectroscopy. The EPR signal from bound iron(III) indicated high-spin octahedral sites and, as also seen for NM, the signal is coupled to a signal from a radical associated with the melanic components of the conjugates. However, the intensity of the EPR signal from iron suggested a reduced fraction of the total iron, indicating that most of the iron is strongly coupled in clusters within the matrix. The amount of paramagnetic, mononuclear iron(III) was greater in the pheomelanin–BSA conjugates, suggesting that iron clustering is reduced in the sulfur-containing pigment. Thus, the melanin–BSA conjugates appear to be good models for the natural pigment. 相似文献
32.
Giulia Andrighetto Jordi Brandts Rosaria Conte Jordi Sabater-Mir Hector Solaz Daniel Villatoro 《PloS one》2013,8(6)
Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices. 相似文献
33.
Emanuele Lombardo Cristian Sabellico Jan Hájek Veronika Staňková Tomá? Filipsky Valentina Balducci Paolo De Vito Stefano Leone Eugenia I. Bavavea Ilaria Proietti Silvestri Giuliana Righi Paolo Luly Luciano Saso Paolo Bovicelli Jens Z. Pedersen Sandra Incerpi 《PloS one》2013,8(4)
Natural polyphenol compounds are often good antioxidants, but they also cause damage to cells through more or less specific interactions with proteins. To distinguish antioxidant activity from cytotoxic effects we have tested four structurally related hydroxyflavones (baicalein, mosloflavone, negletein, and 5,6-dihydroxyflavone) at very low and physiologically relevant levels, using two different cell lines, L-6 myoblasts and THP-1 monocytes. Measurements using intracellular fluorescent probes and electron paramagnetic resonance spectroscopy in combination with cytotoxicity assays showed strong antioxidant activities for baicalein and 5,6-dihydroxyflavone at picomolar concentrations, while 10 nM partially protected monocytes against the strong oxidative stress induced by 200 µM cumene hydroperoxide. Wide range dose-dependence curves were introduced to characterize and distinguish the mechanism and targets of different flavone antioxidants, and identify cytotoxic effects which only became detectable at micromolar concentrations. Analysis of these dose-dependence curves made it possible to exclude a protein-mediated antioxidant response, as well as a mechanism based on the simple stoichiometric scavenging of radicals. The results demonstrate that these flavones do not act on the same radicals as the flavonol quercetin. Considering the normal concentrations of all the endogenous antioxidants in cells, the addition of picomolar or nanomolar levels of these flavones should not be expected to produce any detectable increase in the total cellular antioxidant capacity. The significant intracellular antioxidant activity observed with 1 pM baicalein means that it must be scavenging radicals that for some reason are not eliminated by the endogenous antioxidants. The strong antioxidant effects found suggest these flavones, as well as quercetin and similar polyphenolic antioxidants, at physiologically relevant concentrations act as redox mediators to enable endogenous antioxidants to reach and scavenge different pools of otherwise inaccessible radicals. 相似文献
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35.
Vitantonio Di Bello Iacopo Fabiani Lorenzo Conte Valentina Barletta Maria Grazia Delle Donne Cucco Cuono Laura Anna Leo Frank Lloyd Dini Mario Marzilli Aldo Pinchera Ferruccio Santini 《Obesity (Silver Spring, Md.)》2013,21(5):881-892
Objective:
Obesity has reached global epidemic proportions and is associated with numerous comorbidities, including major cardiovascular (CV) diseases.Design and Methods:
It has many adverse effects on hemodynamics and CV structure and function: it increases total blood volume and cardiac output, and the cardiac workload is greater. Typically, obese patients have a higher cardiac output but a lower level of total peripheral resistance at any given level of arterial pressure. Most of the increase in cardiac output in obesity is caused by stroke volume, although heart rate typically mildly increases also due to enhanced sympathetic activation.Results:
Over the last few years, experimental investigations have unraveled some important pathogenetic mechanisms that may underlie a specific form of “obesity cardiomyopathy.” Bariatric surgery represents an effective alternative to treat obesity when nonsurgical weight loss programs (diet + behavior modifications + regular exercise) have failed. A great numbers of questions are still open in the global comprehension of the pathophysiological interactions between obesity and heart.Conclusion:
Conventional two‐dimensional Doppler echocardiography, integrated by relative new technological ultrasonic approaches, represents the reference technique to study and possibly clarify both the very complex hemodynamic changes induced by obesity and those relative to obesity treatment. 相似文献36.
Serena Candela Raffaele Dito Barbara Casolla Emanuele Silvestri Giuliano Sette Federico Filippi Maurizio Taurino Domitilla Brancadoro Francesco Orzi 《PloS one》2016,11(4)
BackgroundCEA is associated with peri-operative risk of brain ischemia, due both to emboli production caused by manipulation of the plaque and to potentially noxious reduction of cerebral blood flow by carotid clamping. Mild hypothermia (34–35°C) is probably the most effective approach to protect brain from ischemic insult. It is therefore a substantial hypothesis that hypothermia lowers the risk of ischemic brain damage potentially associated with CEA. Purpose of the study is to test whether systemic endovascular cooling to a target of 34.5–35°C, initiated before and maintained during CEA, is feasible and safe.MethodsThe study was carried out in 7 consecutive patients referred to the Vascular Surgery Unit and judged eligible for CEA. Cooling was initiated 60–90 min before CEA, by endovascular approach (Zoll system). The target temperature was maintained during CEA, followed by passive, controlled rewarming (0.4°C/h). The whole procedure was carried out under anesthesia.ResultsAll the patients enrolled had no adverse events. Two patients exhibited a transient bradycardia (heart rate 30 beats/min). There were no significant differences in the clinical status, laboratory and physiological data measured before and after CEA.ConclusionsSystemic cooling to 34.5–35.0°C, initiated before and maintained during carotid clamping, is feasible and safe.
Trial Registration
ClinicalTrials.gov NCT02629653相似文献37.
38.
Ecological genetics of Italian peach‐potato aphid (Myzus persicae) populations in relation to geography,dispersal and insecticide resistance as studied using microsatellite and resistance markers 下载免费PDF全文
Valentina Monti Hugh D. Loxdale Michele Cesari Milo Frattini Michela Panini Emanuele Mazzoni Gian Carlo Manicardi 《Agricultural and Forest Entomology》2016,18(4):376-389
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39.
40.
Tree growth,cambial phenology,and wood anatomy of limber pine at a Great Basin (USA) mountain observatory 总被引:1,自引:0,他引:1