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81.
Despite repeated suggestions that antioxidant activity of conjugated linoleic acid (CLA), a collective of conjugated dienoic
isomers of linoleic acid, underlies its reported anticarcinogenic and antiatherosclerotic effects, the antioxidant properties
of CLA remain ill-defined. Therefore, this study was undertaken to gain more insight into the mechanism of potential CLA antioxidant
activity. It was tested whether CLA could protect membranes composed of 1-palmitoyl-2-linoleoyl phosphatidylcholine (PLPC)
from oxidative modification under conditions of metal ion-dependent or-independent oxidative stress. Progress of oxidation
was determined by direct spectrophotometric measurement of conjugated diene formation and by gas chromatographic/mass spectrometric
analysis of fatty acids. The oxidative susceptibility of CLA was higher than that of linoleic acid, and comparable to arachidonic
acid. When oxidation of PLPC (1.0 mM) was initiated using the lipid-soluble 2,2′-azobis(2,4-dimethylvaleronitrile) or the water-soluble 2,2′-azobis(2-amidinopropane) hydrochloride, the radical scavengers vitamin E and butylated hydroxytoluene (BHT) at 0.75 μM efficiently
inhibited PLPC oxidation, as evident from a clear lagphase. In contrast, 0.75 μM CLA did not have any significant effect on PLPC oxidation. Inhibition of PLPC oxidation by higher concentrations
of CLA appeared due to competition, not to an antioxidant effect. When oxidation of PLPC was initiated by hydrogen peroxide/Fe2+ (500 μM/0.05–20 μM), both vitamin E (1 μM) and ethylene glycol-bis(aminoethyl ether) tetraacetic acid (50 μM) efficiently inhibited PLPC oxidation. However, CLA (1–50 μM) did not show a clear
protective effect under any of the conditions tested. We conclude that CLA, under these test conditions, does not act as an
efficient radical scavenger in any way comparable to vitamin E or BHT. CLA also does not appear to be converted into a metal
chelator under metal-ion dependent oxidative stress, as had previously been suggested. On the basis of our observations, a
role for CLA as an antioxidant does not seem plausible. 相似文献
82.
Abstract The objective of this work will be to look at basic micro-level simulations of liquid state and movement. Defining liquid movement at fiber-coating boundaries is essential when modeling surface wetting of paper fibers. Drying studies have shown that chemical additives in base paper or coating color may reduce or increase quality, productivity, and energy efficiency considerably. The latest question is, Which are the factors that are significantly influencing liquid movement at fiber-coating boundaries? A phenomenon of less liquid drainage at lower paper moisture content is studied in this work together with the fiber hornification process. Fiber hornification is a complex change in the physicochemical properties of the fiber surface and the state of boundary molecules. Another important objective is to show how hornification may be accounted for in basic calculations. This while, printing properties of paper (mottling, etc.), may then be connected to the formation of the base paper and its drying history, explaining in more detail the importance of microlevel physicochemical property changes at fiber surfaces. 相似文献
83.
Stefano Panebianco Klara Berg Jean-Christophe David Mohamed Eid Uwe Filges Friedrich Gröschel Arnaud Guertin Alexander Yu Konobeyev Christian Latgé Sébastien Lemaire Sylvie Leray Alain Letourneau Markus Lüthy Franco Michel-Sendis Selene Scazzi Gediminas Stankunas Nicolas Thiollière Leonhard Tobler Luca Zanini 《Annals of Nuclear Energy》2009
The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment. 相似文献
84.
Simonetta Pazzaglia Barbara Tanno Ilaria De Stefano Paola Giardullo Simona Leonardi Caterina Merla Gabriele Babini Seda Tuncay Cagatay Ammar Mayah Munira Kadhim Fiona M. Lyng Christine von Toerne Zohaib N. Khan Prabal Subedi Soile Tapio Anna Saran Mariateresa Mancuso 《International journal of molecular sciences》2022,23(4)
Cell communication via exosomes is capable of influencing cell fate in stress situations such as exposure to ionizing radiation. In vitro and in vivo studies have shown that exosomes might play a role in out-of-target radiation effects by carrying molecular signaling mediators of radiation damage, as well as opposite protective functions resulting in resistance to radiotherapy. However, a global understanding of exosomes and their radiation-induced regulation, especially within the context of an intact mammalian organism, has been lacking. In this in vivo study, we demonstrate that, compared to sham-irradiated (SI) mice, a distinct pattern of proteins and miRNAs is found packaged into circulating plasma exosomes after whole-body and partial-body irradiation (WBI and PBI) with 2 Gy X-rays. A high number of deregulated proteins (59% of WBI and 67% of PBI) was found in the exosomes of irradiated mice. In total, 57 and 13 miRNAs were deregulated in WBI and PBI groups, respectively, suggesting that the miRNA cargo is influenced by the tissue volume exposed to radiation. In addition, five miRNAs (miR-99b-3p, miR-200a-3p, miR-200a, miR-182-5p, miR-182) were commonly overexpressed in the exosomes from the WBI and PBI groups. In this study, particular emphasis was also given to the determination of the in vivo effect of exosome transfer by intracranial injection in the highly radiosensitive neonatal cerebellum at postnatal day 3. In accordance with a major overall anti-apoptotic function of the commonly deregulated miRNAs, here, we report that exosomes from the plasma of irradiated mice, especially in the case of WBI, prevent radiation-induced apoptosis, thus holding promise for exosome-based future therapeutic applications against radiation injury. 相似文献
85.
Daniele Penchini Giovanni Cinti Gabriele Discepoli Umberto Desideri 《International Journal of Hydrogen Energy》2014
High temperature steam electrolyzers, taking advantage of high temperature heat, can produce more hydrogen by using less electrical energy than low temperature electrolyzers. This paper presents an experimental study on hydrogen production by using a 200 W solid oxide stack working in reverse mode. A thermodynamic study of the process was performed by measuring the heat and mass balance of stack at different operating conditions. Different definitions of efficiency were used to highlight the limit and potential of the process. The I–V curve, the flow rate measurements and the GC analysis on outlet flows were used to calculate the hydrogen and oxygen productions. In addition, the influence of steam dilution, water utilization and operating temperature on conversion efficiency and stack's thermal balance was evaluated. With this aim, the tests were performed at three operating temperature (700 °C, 750 °C and 800 °C) over a range of steam inlet concentration from 50% to 90% and water utilization up to 70%. The hydrogen and oxygen flows produced by electrolysis, at different loads, were directly measured after water condensation: net flows up to 2.4 ml/(min cm2) of hydrogen and 1.2 ml/(min cm2) of oxygen were measured and compared to the theoretical ones, showing a good agreement. 相似文献
86.
Roberto Chiabrando Enrico Fabrizio Gabriele Garnero 《Renewable & Sustainable Energy Reviews》2009,13(9):2441-2451
The installation and operation of systems that exploit solar energy through photovoltaic conversion, recently promoted in some European countries by new sell-back tariffs, is a relevant transformation of the territory for various reasons (land use, elimination of the existing vegetation, visual impact on the components of the landscape, microclimate change, glare from the reflection of the direct sunlight). The weak energy intensity of the solar source coupled with the low conversion efficiency of the photovoltaic cells, make the physical dimensions of such systems relevant and, with them, also the environmental, territorial and landscape impacts that basically depend on the physical extent of the system. If it is well known that an incentive to the exploitation of renewable sources is one of the features of the policy of land conservation, including the one of the protected areas, at the same time the concerns of local communities and governments about the environmental, territorial and landscape impacts of this technology are increasing rapidly.Given this picture, this work is intended to clarify the territorial impacts of the ground mounted photovoltaic systems. Later, the paper concentrates on a specific impact, which is the assessment of the risk of glare by reflection of direct sunlight from the surfaces of photovoltaic modules. The methodologies that can be used to assess this impact and the outcomes of an evaluation carried out for a 5000 m2 PV system currently designed on a hilly territory in Italy are presented. 相似文献
87.
The aim of this study was to explore the long-term effects of affect-focused body psychotherapy (ABP) for patients with generalized anxiety disorder (GAD). A group of 61 consecutive patients, 21–55 years old, were randomized to ABP and psychiatric treatment as usual (TAU). The patients were assessed before treatment and followed up 1 and 2 years after inclusion. The ABP patients received one session of treatment per week during 1 year. Three self-report questionnaires were administered; Symptom Checklist—90, Beck Anxiety Inventory, and the WHO (Ten) Well-Being Index. In both groups, there was a significant improvement. On termination, the ABP group had improved significantly more on the SCL-90 Global Symptom Index than the TAU group, whereas the differences were short of significance on the other two scales. The integration of bodily techniques with a focus on affects in a psychodynamically informed treatment seems to be a viable treatment alternative for patients with GAD. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
88.
Fire-fighters, paramedics, and emergency medical technicians routinely confront potentially traumatic events in the course of their jobs. The mediation role of coping strategies and collective efficacy in the relationship between stress appraisal and quality of life was examined (compassion satisfaction, compassion fatigue, and burnout) in a correlational study. Participants were 463 Italian rescue workers (fire fighters and different categories of emergency health care professionals). Participants filled out measures of stress appraisal, collective efficacy, coping strategies, and quality of life. The results showed that emotion and support coping, self-blame coping, and self-distraction mediated the relationship between stress appraisal and compassion fatigue. Moreover, collective efficacy, self-blame coping, and religious coping mediated the relationship between stress appraisal and burnout. Finally, collective efficacy, self-blame coping, and problem-focused coping mediated the relationship between stress appraisal and compassion satisfaction. Cognitive restructuring and denial did not mediate the relation between stress appraisal and any of the quality of life dimensions. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
89.
Gabriele Boscaino Bernardo Celauro Clara Celauro Antonio Amadore 《Construction and Building Materials》2009,23(2):943-952
An experimental and analytical investigation was carried out both in laboratory and in situ on wearing courses. The approach presented in this paper aims to predict the in situ density and surface properties of bituminous layers, during the phase of mix design in laboratory. Therefore, the main attempt of this study is to identify, amongst the commonly available laboratory equipments, the most adequate for producing specimens that, used for carrying out simple and reliable laboratory test, allow the prediction of the surface characteristics of the mixture as laid on site.This is done by comparing the data collected from an experimental site with those calculated from laboratory specimens compacted with the superpave gyratory compactor (SGC).Typical laboratory tests (such as the sand patch method and the skid test) as well as the surface data obtained with a laser profilometer have been considered for characterizing the properties of a standard Italian wearing course, laid in two different final thicknesses and produced with the most common raw materials, according to the currently used techniques for mixtures production and laying process for maintenance work. An evaluation of the SGC ability to represent the density and surface properties of the mixture once on site is then discussed. 相似文献
90.
The assessment of the damage probability of storage tanks in domino events triggered by fire 总被引:1,自引:0,他引:1
Gabriele Landucci Gianfilippo Gubinelli Giacomo Antonioni Valerio Cozzani 《Accident; analysis and prevention》2009,41(6):1206-1215
An approach aimed to the quantitative assessment of the risk caused by escalation scenarios triggered by fire was developed. Simplified models for the estimation of the vessel time to failure (ttf) with respect to the radiation intensity on the vessel shell were obtained using a multi-level approach to the analysis of vessel wall failure under different fire conditions. Each vessel “time to failure” calculated by this approach for the specific fire scenario of concern was compared to a reference time required for effective mitigation actions and related to the escalation probability. The failure probability of each vessel was correlated to the probability of scenarios involving multiple vessel failure as a consequence of the primary fire, thus allowing a comprehensive assessment of domino scenarios triggered by fire. The application of the methodology to the analysis of several case-studies allowed the estimation of the quantitative contribution of escalation events triggered by fire to the overall individual and societal risk indexes. 相似文献