The cytotoxicity, mechanism of cell death, mitotic activity, and

The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis-block proliferation index, and superoxide dismutase-inhibitable reduction of ferricytochrome c, respectively. The genotoxicity was measured using PND-1186 concentration comet assay and cytokinesis-block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose- and time-dependent manner (p smaller than 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown

DNA damage in a dose-dependent manner (p smaller than 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose-dependent manner (p smaller than 0.05). Taken together, the data suggested that CHX-induced cytotoxicity and genotoxicity on macrophages may be via ROS generation. (c) 2012 Wiley Periodicals, Inc. Environ compound screening assay Toxicol 29: 452-458, 2014.”
“In this paper, I discuss the discovery of the DNA structure by Francis Crick and James Watson, which has provoked a large

historical literature but has yet not found entry into philosophical debates. I want to redress this imbalance. In contrast to the available historical literature, a strong emphasis will be placed upon analysing the roles played by theory, model, and evidence and the relationship between them. In particular, I am going to discuss not only Crick and Watson’s well-known model and Franklin’s x-ray diffraction pictures (the evidence) but also the less well known theory of helical diffraction, which was absolutely crucial to Crick and Watson’s discovery. The insights into this groundbreaking selleck chemicals llc historical episode will have consequences for the ‘new’ received view of scientific models and their function and relationship

to theory and world. The received view, dominated by works by Cartwright and Morgan and Morrison ([1999]), rather than trying to put forth a ‘theory of models’, is interested in questions to do with (i) the function of models in scientific practice and (ii) the construction of models. In regard to (i), the received view locates the model (as an idealized, simplified version of the real system under investigation) between theory and the world and sees the model as allowing the application of the former to the latter. As to (ii) Cartwright has argued for a phenomenologically driven view and Morgan and Morrison ([1999]) for the ‘autonomy’ of models in the construction process: models are determined neither by theory nor by the world. The present case study of the discovery of the DNA structure strongly challenges both (i) and (ii). In contrast to claim (i) of the received view, it was not Crick and Watson’s model but rather the helical diffraction theory which served a mediating purpose between the model and the x-ray diffraction pictures.

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