1,564 research outputs found

    unfixed and fixed human chromosomes show different staining patterns after restriction endonuclease digestion

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    Restriction endonucleases (REs) have been widely used to produce banding patterns on chromosomes, but it remains uncertain to what extent the patterns are due to the sequence specificity of the enzymes, and to what extent chromatin structure influences the pattern of digestion. To throw light on this question, we have digested with restriction endonucleases unfixed chromosomes prepared in two different ways (isolated, and whole metaphase cells spread with a cytocentrifuge) and compared the results with those obtained on conventionally fixed chromosomes. Unfixed isolated chromosomes are easily destroyed by REs; after fixation with cold methanol, which produced minimal alteration to the chromatin structure, the chromosomes are resistant to the action of REs, and conventional methanol-acetic acid fixation is required to permit the induction of banding patterns by REs. Unfixed cytocentrifuge preparations, in which the chromosomes are still surrounded by cytoplasm, are much more resistant to the action of REs, and again banding patterns were only induced after methanol-acetic acid fixation. We conclude that the action of restriction endonucleases on chromosomes is strongly influenced by chromatin organisation, and that methanol-acetic acid fixation is required to permit the induction of conventional banding patterns on chromosomes

    Characterization methodology for re-using marble slurry in industrial applications

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    Nowadays calcium carbonate has a great importance in different industrial fields and currently there is the opportunity of appreciate the potential value of marble waste and convert it into marketable products. Marble slurry samples, collected from different dimension stone treatment plants in Orosei marble district (Sardinia - Italy), were chemically, physically, mineralogically, and morphologically analyzed and the obtained data were evaluated for compatibility with the marketable micronized CaCO3 specifications required by some industrial sectors, estimating the prospects of recovered CaCO3 utilization. Besides the economic benefits, transforming a waste into an important economic resource involves environmental advantages, due to reduced marble waste landfills, and sustainability promotion

    Modeling electrodialysis and a photochemical process for their integration in saline wastewater treatment.

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    Oxidation processes can be used to treat industrial wastewater containing non-biodegradable organic compounds. However, the presence of dissolved salts may inhibit or retard the treatment process. In this study, wastewater desalination by electrodialysis (ED) associated with an advanced oxidation process (photo-Fenton) was applied to an aqueous NaCl solution containing phenol. The influence of process variables on the demineralization factor was investigated for ED in pilot scale and a correlation was obtained between the phenol, salt and water fluxes with the driving force. The oxidation process was investigated in a laboratory batch reactor and a model based on artificial neural networks was developed by fitting the experimental data describing the reaction rate as a function of the input variables. With the experimental parameters of both processes, a dynamic model was developed for ED and a continuous model, using a plug flow reactor approach, for the oxidation process. Finally, the hybrid model simulation could validate different scenarios of the integrated system and can be used for process optimization

    Interactions of lipid monolayers with the natural biopolymer hyaluronic acid

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    AbstractThe interaction of the natural mucopolysaccharide hyaluronic acid with different lipids, present in the natural membranes, was studied at the lipid/water interface using thermodynamic methods and X-ray diffraction. The results show that this biopolymer modifies the properties and the structure of the lipid monolayer. The two-dimensional crystalline lattice and domain structure of the charged octadecylamine monolayer are strongly disturbed by the hyaluronic acid, the monolayer compressibility increases and the monolayer collapse pressure drops down. In addition, the presence of charged lipid interfaces influences the structural organisation of the hyaluronic acid at the membrane/water interfaces. The impacts of these results on the structural organisation at the membrane interface are discussed

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    Genetics in orthopaedic practice

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    DNA holds genetic information in the nucleus of eukaryotic cells; and has three different functions: replication, storage of hereditary information, and regulation of cell division. Most studies described the association of single nucleotide polymorphism (SNP) to common orthopaedics diseases and the susceptibility to develop musculoskeletal injuries. Several mutations are associated with osteoporosis, musculoskeletal ailments and other musculoskeletal deformity and conditions. Several strategies, including gene therapy and tissue engineering with mesenchymal stem cells (MSC), have been proposed to enhance healing of musculoskeletal tissues. Furthermore, a recent technique has revolutionized gene editing: clustered regulatory interspaced short palindromic repeat (CRISPR) technology is characterized by simplicity in target design, affordability, versatility, and high efficiency, but needs more studies to become the preferred platform for genome editing. Predictive genomics DNA profiling allows to understand which genetic advantage, if any, may be exploited, and why a given rehabilitation protocol can be more effective in some individual than others. In conclusion, a better understanding of the genetic influence on the function of the musculoskeletal system and healing of its ailments is needed to plan and develop patient specific management strategies

    3‐D GPR Imaging of Complex Fluvial Stratigraphy at the Boise Hydrogeophysical Research Site

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    A series of three-dimensional (3-D) ground-penetrating radar (GPR) data sets were acquired over the central wellfield area at the Boise Hydrogeophysical Research Site (BHRS). The survey region is 30 m x 18 m and encompasses 13 wells. The goal of the surveys is to image the complex fluvial (cobble-and-sand) stratigraphy around the wellfield. These images will be used to construct 3-D models of the sedimentary architecture and to help constrain fine-scale models of hydrologic and geophysical parameters at the site. The data sets were acquired using 25 MHz, 50 MHz, 100 MHz and 200 MHz antennas. Depth of penetration ranges from -9.6 m for the 200 MHz data to -22 m for the 25 MHz data. Processing significantly improves the reliability and interpretability of the images. The images suggest that the deposit can be subdivided laterally and vertically into several distinct units or radar architectural elements; these elements are typically separated by erosional bounding surfaces. Horizontal bedding, cross-bedding and channel structures are clearly evident in the 100 MHz and 200 MHz data, and a clay layer that underlies the cobble-and-sand aquifer at -20 m depth is successfully imaged in the 25 MHz and 50 MHz data. The water table, at a depth of l-2 m, is imaged in the 100 MHz and 200 MHz data. Time slices and vertical cuts through the data volumes are used to identify the shape and orientation of the different architectural elements, and to accurately locate important hydrostratigraphic boundaries. These data are being used to construct a 3-D model of the hydrogeologic zonation of the aquifer. Hydrologic and geophysical parameter values associated with each zone will be determined from additional field measurements (e.g., hydraulic tests in wells, crosshole radar and seismic tomography, transient electromagnetics, and well logs). The 3-D GPR surveys provide valuable information about the location, scale and geometry of different stratigraphic units at the BHRS
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