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71.
An efficient scavenger for radiolytically generated hydroxyl (OH) radicals, p-nitrosodimethylaniline, was used to try to substantiate the presence of this oxygen radical species in several biochemical systems. Most of these systems which were investigated had previously been assumed to generate OH radicals, e.g. the autoxidation of 6-hydroxydopamine, the hydroxylating system NADH/phenazine methosulfate, and the oxidation of xanthine or acetaldehyde by xanthine oxidase. We did not observe inhibition of the bleaching of p-nitrosodimethylaniline in oxygenated solutions by other scavengers of OH radicals nor, in the case of xanthine/xanthine oxidase, by catalase and superoxide dismutase. We therefore conclude that, under biochemical conditions as opposed to radiolysis or photolysis, no freely diffusable OH radicals are formed. Rather, a strongly oxidizing OH-analogous complex is considered to represent the p-nitrosodimethylaniline-detectable species formed under these conditions.  相似文献   
72.
Superoxide anions do not react with hydroperoxides.   总被引:1,自引:0,他引:1  
W Bors  C Michel  M Saran 《FEBS letters》1979,107(2):403-406
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In the areas studied, an unusual structure and dynamic behavior was exhibited by the plankton ecosystems, due for the most part to industrial and natural effluents from the Rhǒne and Durance. The ecosystem was kept at a low state of maturity, which is characterized by frequent periods of intense multiplication by small species with high metabolic rates, such as the diatom, Skeletonema costatum, and the dinoflagellates, Exuviaella and Prorocentrum. Brackish water seems congenial to that type of proliferation. The turnover rate of these populations decreases as they become older and cell size increases. A lack of competition by species of the same genus is a characteristic of the photo-autotrophic organisms in these environments. Secondary production follows the same cycle as the primary production by the dinoflagellate population. Zooplankton species of the genus Acartia have periods of intensive development in these areas.  相似文献   
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Research needs a balance of risk‐taking in “breakthrough projects” and gradual progress. For building a sustainable knowledge base, it is indispensable to provide support for both. Subject Categories: Careers, Economics, Law & Politics, Science Policy & Publishing

Science is about venturing into the unknown to find unexpected insights and establish new knowledge. Increasingly, academic institutions and funding agencies such as the European Research Council (ERC) explicitly encourage and support scientists to foster risky and hopefully ground‐breaking research. Such incentives are important and have been greatly appreciated by the scientific community. However, the success of the ERC has had its downsides, as other actors in the funding ecosystem have adopted the ERC’s focus on “breakthrough science” and respective notions of scientific excellence. We argue that these tendencies are concerning since disruptive breakthrough innovation is not the only form of innovation in research. While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science. This is problematic since, paradoxically, breakthrough potential in science builds on gradual innovation. If the value of gradual innovation is not better recognized, the potential for breakthrough innovation may well be stifled.
While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science.
Concerns that the hypercompetitive dynamics of the current scientific system may impede rather than spur innovative research have been voiced for many years (Alberts et al, 2014). As performance indicators continue to play a central role for promotions and grants, researchers are under pressure to publish extensively, quickly, and preferably in high‐ranking journals (Burrows, 2012). These dynamics increase the risk of mental health issues among scientists (Jaremka et al, 2020), dis‐incentivise relevant and important work (Benedictus et al, 2016), decrease the quality of scientific papers (Sarewitz, 2016) and induce conservative and short‐term thinking rather than risk‐taking and original thinking required for scientific innovation (Alberts et al, 2014; Fochler et al, 2016). Against this background, strong incentives for fostering innovative and daring research are indispensable.  相似文献   
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Epicardial fat is a relatively neglected component of the heart and could be an important risk factor of cardiac disease. The objective of our study was to assess the relationship between epicardial adipose tissue (EAT) extent, fat distribution, and coronaropathy in a group of adult victims of accidental or suspicious sudden death. In 56 cadavers, we performed 34 measurements of EAT from five computerized photographs of the heart (anterior and posterior faces, and three ventricle transversal slices) and analyzed their relationship with anthropometric markers of adiposity (BMI, waist and leg circumference, thickness of abdominal and thigh subcutaneous adipose tissue (SAT)), with the presence and staging of coronary artery disease (CAD), and with markers of myocardial hypertrophy. Simple linear regressions showed that EAT measurements are highly intercorrelated (r from 0.4 to 0.6, P < 0.001), and correlate with age, waist circumference, and heart weight, and to a lesser extent, with BMI, abdominal SAT thickness, and leg SAT thickness. Multiple regression showed that age, waist circumference, and heart weight significantly and independently correlate with EAT (P < 0.0001). No other anthropometric measurement was found independently correlated with EAT. The EAT/myocardium ratios correlated positively with age and waist circumference. Anterior and posterior areas of EAT were found significantly increased in patients with CAD and correlated positively with CAD staging (P = 0.0034, r = 0.38). Anterior EAT surface was found positively associated with CAD (P = 0.01), independently of age and other adiposity measurements. Prospective studies are needed to assess the risk of occurrence/progression of CAD that relate to EAT excess.  相似文献   
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Honey bees play a critical role in the maintenance of plant biodiversity and sustainability of food webs. In the past few decades, bees have been subjected to biotic and abiotic threats causing various colony disorders. Therefore, monitoring solutions to help beekeepers to improve bee health are necessary. Matrix‐assisted laser desorption ionization–mass spectrometry (MALDI–MS) profiling has emerged within this decade as a powerful tool to identify in routine micro‐organisms and is currently used in real‐time clinical diagnosis. MALDI BeeTyping is developed to monitor significant hemolymph molecular changes in honey bees upon infection with a series of entomopathogenic Gram‐positive and ‐negative bacteria. A Serratia marcescens strain isolated from one naturally infected honey bee collected from the field is also considered. A series of hemolymph molecular mass fingerprints is individually recorded and to the authors' knowledge, the first computational model harboring a predictive score of 97.92% and made of nine molecular signatures that discriminate and classify the honey bees’ systemic response to the bacteria is built. Hence, the model is challenged by classifying a training set of hemolymphs and an overall recognition of 91.93% is obtained. Through this work, a novel, time and cost saving high‐throughput strategy that addresses honey bee health on an individual scale is introduced.  相似文献   
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