50 research outputs found

    “Positive” Results Increase Down the Hierarchy of the Sciences

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    The hypothesis of a Hierarchy of the Sciences with physical sciences at the top, social sciences at the bottom, and biological sciences in-between is nearly 200 years old. This order is intuitive and reflected in many features of academic life, but whether it reflects the “hardness” of scientific research—i.e., the extent to which research questions and results are determined by data and theories as opposed to non-cognitive factors—is controversial. This study analysed 2434 papers published in all disciplines and that declared to have tested a hypothesis. It was determined how many papers reported a “positive” (full or partial) or “negative” support for the tested hypothesis. If the hierarchy hypothesis is correct, then researchers in “softer” sciences should have fewer constraints to their conscious and unconscious biases, and therefore report more positive outcomes. Results confirmed the predictions at all levels considered: discipline, domain and methodology broadly defined. Controlling for observed differences between pure and applied disciplines, and between papers testing one or several hypotheses, the odds of reporting a positive result were around 5 times higher among papers in the disciplines of Psychology and Psychiatry and Economics and Business compared to Space Science, 2.3 times higher in the domain of social sciences compared to the physical sciences, and 3.4 times higher in studies applying behavioural and social methodologies on people compared to physical and chemical studies on non-biological material. In all comparisons, biological studies had intermediate values. These results suggest that the nature of hypotheses tested and the logical and methodological rigour employed to test them vary systematically across disciplines and fields, depending on the complexity of the subject matter and possibly other factors (e.g., a field's level of historical and/or intellectual development). On the other hand, these results support the scientific status of the social sciences against claims that they are completely subjective, by showing that, when they adopt a scientific approach to discovery, they differ from the natural sciences only by a matter of degree

    Recent advances in the colorimetric detection of cyanide

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    This short-review discusses the recent developments in the colorimetric detection of cyanide with different types of receptors. Significant progress in terms of selectivity, sensitivity and straightforwardness has been observed for either organic-, main group- or transition metal-based sensors. Our group has developed a simple and highly specific system for the optical sensing of cyanide based on the conformational switch of commercially available vitamin B12

    Specific colorimetric detection of cyanide triggered by a conformational switch in vitamin B12

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    "Base on"/"base off" coordination of the intramolecular bound benzimidazole nucleobase of vitamin B 12 allows the specific colorimetric detection of millimolar concentrations of cyanide in water. In various competition experiments, it was demonstrated that up to 12 different anions as well as a 1000-fold excess of Cl (-) over CN (-) do no interfere with the sensor. An 8-fold increased sensitivity in the "naked eye" detection of CN (-) was observed when water was replaced by MeOH/H 2O (5%) as a solvent

    Coordination chemistry and biological activity of 5â€Č-OH modified quinoline–B12 derivatives

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    The consequences of structural modifications at the 5Âą-OH ribofuranotide moiety of quinoline modified B12 derivatives are discussed in regard of the coordination chemistry, the electrochemical properties and the biological behaviour of the compound

    Controlling binding dynamics of corrin-based chemosensors for cyanide

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    This paper describes a strategy to control the binding dynamics between cyanide and aquacyanocorrinoids on the molecular level. Aquacyanocorrinoids represent an important class of chemosensors and convert upon cyanide coordination to the corresponding dicyano derivatives. Structure–reactivity relationships were investigated for the first time by synthesizing and studying three diastereomerically pure aquacyanocorrinoids differing either in the configuration of the axially bound ligands or in the nature of remote side chains located at the periphery of the corrin macrocycle. Substitution of cobalt-coordinated water with cyanide was investigated using stopped-flow measurements between 5 and 30 °C, and second order rate constants and activation parameters were determined. In particular, it is demonstrated that the binding kinetics depend not only on (i) the configuration at the central metal center but also on (ii) the remote structural modifications of the macrocycle
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