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41.
Buunk Bram P.; Collins Rebecca L.; Taylor Shelley E.; VanYperen Nico W.; Dakof Gayle A. 《Canadian Metallurgical Quarterly》1990,59(6):1238
Research on social comparison processes has assumed that a comparison in a given direction (upward or downward) will lead to a particular affective reaction. In contrast, the present 2 studies proposed and found that a comparison can produce either positive or negative feelings about oneself, independent of its direction. Several factors moderated the tendency to derive positive or negative affect from upward and downward comparisons. In Study 1, cancer patients low in self-esteem and with low perceived control over their symptoms and illness were more likely to see downward comparisons as having negative implications for themselves. Those low in self-esteem were also more likely to perceive upward comparisons as negative. In Study 2, individuals with high marital dissatisfaction and those who felt uncertain about their marital relationship were more likely to experience negative affect from upward and downward comparisons. The implications of these findings for social comparison theory and for the coping and adaptation literature are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
Smoldering combustion in a packed bed of carbonaceous material is a very complex process, where numerous physical and chemical parameters are involved. This study was conducted to examine the impact of several physical parameters on the behavior of natural downward smoldering. For that purpose, a one-dimensional homogeneous model has been developed. Due to the fact that drying, pyrolysis or oxidative degradation occurs significantly faster than carbon oxidation, only the latter phenomenon was taken into account. The model was evaluated by comparison of numerical simulation results with experimental observations. Sensitivity analysis calculations of different physical properties of the bed material with respect to smoldering time, smoldering front velocity and front temperature suggest that in future experiments special attention should be devoted to accurate determination of bed shrinkage, bulk carbon density, mean void size, oxygen diffusivity in fuel bed. 相似文献
43.
44.
Synthesis of 2‐[18F]Fluoro‐2‐deoxyisosorbide 5‐mononitrate and Assessment of Its in vivo Biodistribution as Determined by Dynamic Positron Emission Tomography (PET)
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Dr. Nico Santschi Dr. Stefan Wagner Dr. Constantin Daniliuc Dr. Sven Hermann Prof. Dr. Michael Schäfers Prof. Dr. Ryan Gilmour 《ChemMedChem》2015,10(10):1724-1732
Herein we disclose the synthesis of 2‐fluoro‐2‐deoxyisosorbide 5‐mononitrate (2F‐IS‐5MN), a fluorinated analogue of the commonly prescribed vasodilator isosorbide 5‐mononitrate (IS‐5MN). X‐ray structural data for IS‐5MN and its C2‐epimeric congener IM‐5MN are presented together with structural data for 2F‐IS‐5MN. Radioisotope labeling of 2F‐IS‐5MN has, for the first time, allowed observation of the in vivo biodistribution of this organic nitrate by means of dynamic positron emission tomography (PET) in wild‐type mice. 相似文献
45.
Nanomaterials for environmental studies: Classification, reference material issues, and strategies for physico-chemical characterisation 总被引:1,自引:0,他引:1
Vicki Stone Bernd Nowack Nico van den Brink Maria Dusinska Steven Hankin Erik Joner 《The Science of the total environment》2010,408(7):1745-1754
NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions:
- 1.
- What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies?
- 2.
- What reference materials should be developed for use in environmental and ecotoxicological studies?
- 3.
- Is it possible to group different nanomaterials into categories for consideration in environmental studies?
46.
Lei Zhang Dr. Marina Toplak Raspudin Saleem-Batcha Lars Höing Dr. Roman Jakob Dr. Nico Jehmlich Prof. Dr. Martin von Bergen Prof. Timm Maier Prof. Robin Teufel 《Chembiochem : a European journal of chemical biology》2023,24(2):e202200632
Antimicrobial resistance represents a major threat to human health and knowledge of the underlying mechanisms is therefore vital. Here, we report the discovery and characterization of oxidoreductases that inactivate the broad-spectrum antibiotic chloramphenicol via dual oxidation of the C3-hydroxyl group. Accordingly, chloramphenicol oxidation either depends on standalone glucose-methanol-choline (GMC)-type flavoenzymes, or on additional aldehyde dehydrogenases that boost overall turnover. These enzymes also enable the inactivation of the chloramphenicol analogues thiamphenicol and azidamfenicol, but not of the C3-fluorinated florfenicol. Notably, distinct isofunctional enzymes can be found in Gram-positive (e. g., Streptomyces sp.) and Gram-negative (e. g., Sphingobium sp.) bacteria, which presumably evolved their selectivity for chloramphenicol independently based on phylogenetic analyses. Mechanistic and structural studies provide further insights into the catalytic mechanisms of these biotechnologically interesting enzymes, which, in sum, are both a curse and a blessing by contributing to the spread of antibiotic resistance as well as to the bioremediation of chloramphenicol. 相似文献
47.
Matthias Delafontaine Anthony G. Cohn Nico Van de Weghe 《Expert systems with applications》2011,38(5):5187-5196
Due to recent technological advances in position-aware devices, data about moving objects is becoming ubiquitous. Yet, it is a major challenge for spatial information systems to offer tools for the analysis of motion data, thereby evolving from static to dynamic frameworks. This paper aims to contribute to this area by introducing an implementation prototype for an information system based on the Qualitative Trajectory Calculus, a spatiotemporal calculus to represent and reason about moving point objects. 相似文献
48.
Introducing functional classification theory to land use planning by means of decision tables 总被引:1,自引:0,他引:1
Frank Marc Antrop Peter Bogaert Philippe De Maeyer Ben Derudder Tijs Neutens Veronique Van Acker Nico Van de Weghe 《Decision Support Systems》2009,46(4):875
This paper contributes to the conceptualisation and analysis of double-sided matching problems, taking the land use planning problem as an example. It does so by introducing functional classification theory at the knowledge level, the symbol level and the system level of a DSS. This theory explicitly expresses the methodological viewpoint of relational realism. At the knowledge level this implies defining knowledge on the basis of matching the intension and extension of concepts. At the symbol level it deals with knowledge representation and here decision tables are advanced and formally introduced. At the system level the formalism used at the symbol level is implemented to develop a relational matching DSS. 相似文献
49.
Anna-Maria Spehar-Deleze Johanna Suomi Nico de Rooij Sakari Kulmala 《Electrochimica acta》2006,51(25):5438-5444
This paper describes a heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence (HECL) of a rhodamine label. Thin oxide-film coated aluminum and silicon electrodes were modified with an aminosilane layer and derivatized with short, 15-mer oligonucleotides via diisothiocyanate coupling. Target oligonucleotides were conjugated with tetramethylrhodamine (TAMRA) dye at their amino modified 5′ end and hybridization was detected using HECL of TAMRA. Preliminary results indicate sensitivity down to picomolar level and low nonspecific adsorption. The sensitivity was better on oxide-coated silicon compared to oxide-coated aluminum electrodes and two-base pair mismatched hybrids were successfully discriminated. The experimental results presented here might be useful for the design of disposable electrochemiluminescent DNA biosensors. 相似文献
50.
Nico H L Kuijpers Rikkert H Keldermann Huub M M ten Eikelder Theo Arts Peter A J Hilbers 《IEEE transactions on bio-medical engineering》2006,53(8):1499-1511
Atrial fibrillation is the most common cardiac arrhythmia. Structural cardiac defects such as fibrosis and gap junction remodeling lead to a reduced cellular electrical coupling and are known to promote atrial fibrillation. It has been observed that the expression of the hyperpolarization-activated current If is increased under pathological conditions. Recent experimental data indicate a possible contribution of If to arrhythmogenesis. In this paper, the role of If in action potential propagation in normal and in pathological tissue is investigated by means of computer simulations. The effect of diffuse fibrosis and gap junction remodeling is simulated by reducing cellular coupling nonuniformly. As expected, the conduction velocity decreases when cellular coupling is reduced. In the presence of If the conduction velocity increases both in normal and in pathological tissue. In our simulations, ectopic activity is present in regions with high expression of If and is facilitated by cellular uncoupling. We conclude that an increased If may facilitate propagation of the action potential. Hence, If may prevent conduction slowing and block. Overexpression of If may lead to ectopic activity, especially when cellular coupling is reduced under pathological conditions. 相似文献