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The reuse of scientific knowledge obtained from one investigation in another investigation is basic to the advance of science. Scientific investigations should therefore be recorded in ways that promote the reuse of the knowledge they generate. The use of logical formalisms to describe scientific knowledge has potential advantages in facilitating such reuse. Here, we propose a formal framework for using logical formalisms to promote reuse. We demonstrate the utility of this framework by using it in a worked example from biology: demonstrating cycles of investigation formalization [F] and reuse [R] to generate new knowledge. We first used logic to formally describe a Robot scientist investigation into yeast (Saccharomyces cerevisiae) functional genomics [f1]. With Robot scientists, unlike human scientists, the production of comprehensive metadata about their investigations is a natural by-product of the way they work. We then demonstrated how this formalism enabled the reuse of the research in investigating yeast phenotypes [r1 = R(f1)]. This investigation found that the removal of non-essential enzymes generally resulted in enhanced growth. The phenotype investigation was then formally described using the same logical formalism as the functional genomics investigation [f2 = F(r1)]. We then demonstrated how this formalism enabled the reuse of the phenotype investigation to investigate yeast systems-biology modelling [r2 = R(f2)]. This investigation found that yeast flux-balance analysis models fail to predict the observed changes in growth. Finally, the systems biology investigation was formalized for reuse in future investigations [f3 = F(r2)]. These cycles of reuse are a model for the general reuse of scientific knowledge.  相似文献   
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Lactic acid bacteria‐induced fermentation of fish was tested with the purpose of developing a novel fish food product with desired meat properties. Three selected lactic acid bacteria strains, isolated from lightly preserved fish products, were inoculated into minced frozen fillet of yellowfin tuna, and changes in fish properties were observed during 52 days of storage at 8 °C. Organoleptic, bacteriological and biochemical studies (pH, histamine, TVB‐N, malonaldehyde) and shelf‐life measurements suggest that Leuconostoc mesenteroides could be considered as a possible starter culture for fish fermentation, but additional experiments should be performed. © 2000 Society of Chemical Industry  相似文献   
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Problem solving courseware modules have been developed for students of mechanics of materials. The modules offer students: a better grasp of fundamental principles, an intuitive sense of the meaning of key quantities, and fluency in using relations to solve problems. Students use modules independently and submit electronic log files to instructors who can monitor their progress. Field‐testing of the modules was conducted over a two‐year period at three distinct educational institutions, with 318 students. Courseware users scored as well as or outperformed their non‐using peers on nearly all objective measures of learning, with differences being statistically significant in some cases. Eighty‐eight percent of users found the courseware helpful for learning. After completing one required module, 48 percent of students continued using the courseware, voluntarily, as a reference guide to theory, as a coach for mastering and reviewing basic skills, and as a self‐diagnostic tool, to help with regular homework assignments.  相似文献   
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Larisa Belyanskaya 《Carbon》2007,45(13):2643-2648
The unique physical and chemical properties of carbon nanotubes (CNTs) suggest enormous potential for many areas of research and application. The urgent need for toxicological studies on CNTs has arisen from the steadily increasing production volume. 2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide (MTT) assay is among the most versatile and popular assays used for in vitro toxicology. For particulate samples like CNTs the applicability and limits of various tests including the MTT assay have to be defined. Two MTT assays were applied to study the effect of single-walled CNTs (SWCNTs) on A549 cells. Both assays revealed significant and comparable loss of cell functionality that was confirmed by DNA assay. However, using a cell-free system, we have found that polyoxyethylene sorbitan monooleate-suspended SWCNTs interfere less with MTT assay than sodium dodecyl sulfate-suspended SWCNTs. Moreover, depending on the purification procedure of SWCNTs, they were able to convert MTT into its MTT-formazan insoluble form in the absence of any living system. In summary, a careful validation of MTT assay procedures is therefore suggested in experiments where CNTs are one of the constituents, to avoid a potential bias in concluding results of cytotoxicity studies.  相似文献   
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The Si(001) surface deoxidized by short annealing at T ~ 925°C in the ultrahigh vacuum molecuar beam epitaxy chamber has been in situ investigated using high-resolution scanning tunneling microscopy (STM)and redegreesected high-energy electron diffraction (RHEED. RHEED patterns corresponding to (2 × 1) and (4 × 4) structures were observed during sample treatment. The (4 × 4) reconstruction arose at T ≲ 600°C after annealing. The reconstruction was observed to be reversible: the (4 × 4) structure turned into the (2 × 1) one at T ≳ 600°C, the (4 × 4) structure appeared again at recurring cooling. The c (8 × 8) reconstruction was revealed by STM at room temperature on the same samples. A fraction of the surface area covered by the c (8 × 8) structure decreased, as the sample cooling rate was reduced. The (2 × 1) structure was observed on the surface free of the c (8 × 8) one. The c (8 × 8) structure has been evidenced to manifest itself as the (4 × 4) one in the RHEED patterns. A model of the c (8 × 8) structure formation has been built on the basis of the STM data. Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.  相似文献   
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Topics in Catalysis - Formic acid and methanol are considered as liquid organic hydrogen carriers and could be produced sustainably from biomass or by CO2 hydrogenation using catalysts. The choice...  相似文献   
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The ability of human pluripotent stem cells for unlimited proliferation and self-renewal promotes their application in the fields of regenerative medicine. The morphological assessment of growing colonies and cells, as a non-invasive method, allows the best clones for further clinical applications to be safely selected. For this purpose, we analyzed seven morphological parameters of both colonies and cells extracted from the phase-contrast images of human embryonic stem cell line H9, control human induced pluripotent stem cell (hiPSC) line AD3, and hiPSC line HPCASRi002-A (CaSR) in various passages during their growth for 120 h. The morphological phenotype of each colony was classified using a visual analysis and associated with its potential for pluripotency and clonality maintenance, thus defining the colony phenotype as the control parameter. Using the analysis of variance for the morphological parameters of each line, we showed that selected parameters carried information about different cell lines and different phenotypes within each line. We demonstrated that a model of classification of colonies and cells by phenotype, built on the selected parameters as predictors, recognized the phenotype with an accuracy of 70–75%. In addition, we performed a qRT-PCR analysis of eleven pluripotency markers genes. By analyzing the variance of their expression in samples from different lines and with different phenotypes, we identified group-specific sets of genes that could be used as the most informative ones for the separation of the best clones. Our results indicated the fundamental possibility of constructing a morphological portrait of a colony informative for the automatic identification of the phenotype and for linking this portrait to the expression of pluripotency markers.  相似文献   
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Previously, we showed that a nitric oxide synthase (NOS) inhibitor, compound T1023, induces transient hypoxia and prevents acute radiation syndrome (ARS) in mice. Significant efficacy (according to various tests, dose modifying factor (DMF)—1.6–1.9 against H-ARS/G-ARS) and safety in radioprotective doses (1/5–1/4 LD10) became the reason for testing its ability to prevent complications of tumor radiation therapy (RT). Research methods included studying T1023 effects on skin acute radiation reactions (RSR) in rats and mice without tumors and in tumor-bearing animals. The effects were evaluated using clinical, morphological and histological techniques as well as RTOG classification. T1023 administration prior to irradiation significantly limited the severity of acute RSR. This was due to a decrease in radiation alteration of the skin and underlying tissues, and the preservation of the functional activity of cell populations that are critical in the pathogenesis of radiation burn. The DMF values for T1023 for skin protection were 1.4–1.7. Moreover, its radioprotective effect was fully selective to normal tissues in RT models of solid tumors—T1023 reduced the severity of acute RSR and did not modify the antitumor effects of γ-radiation. The results indicate that T1023 can selectively protect the non-malignant tissues against γ-radiation due to hypoxic mechanism of action and potentiate opportunities of NOS inhibitors in RT complications prevention.  相似文献   
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