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Fortunato, Franco, Thilo Hackert, Markus W. Büchler e Guido Kroemer. "Retrospective electron microscopy: Preservation of fine structure by freezing and aldehyde fixation". Molecular & Cellular Oncology 3, n.º 6 (27 de outubro de 2016): e1251382. http://dx.doi.org/10.1080/23723556.2016.1251382.
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Rostaing, Philippe, Robby M. Weimer, Erik M. Jorgensen, Antoine Triller e Jean-Louis Bessereau. "Preservation of Immunoreactivity and Fine Structure of AdultC. elegansTissues Using High-pressure Freezing". Journal of Histochemistry & Cytochemistry 52, n.º 1 (janeiro de 2004): 1–12. http://dx.doi.org/10.1177/002215540405200101.
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Cox, Donald P. "A New Universal Acrylic Embedding Resin for Both Light and Electron Microcopy". Microscopy Today 2, n.º 4 (julho de 1994): 21–22. http://dx.doi.org/10.1017/s1551929500065585.
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Successful immunolabeling in electron microscopy of animal and plant tissues requires a combination of excellent antigen preservation while maintaining the original structure of the tissue. One important element is tissue embedding which accomplishes two goals for the immunohistochemist, the preservation of tissue specimen structure and maintenance of biological antigenicity. Tissue embedding in plastic resins is a common method in which several important elements must be considered.1.Fine tissue structure must not be damaged by the polymerization.2.The plastic must be stable to the electron beam.3.Light scattering properties of the plastic should be minimal.4.The plastic should cut easily.5.The plastic must be of sufficiently low viscosity to infiltrate the tissue.
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Rogers, Greg S., e John Frett. "682 PB 198 NICOTIANA FIXATION FOR IMMUNO-LOCALIZATION OF IPTASE". HortScience 29, n.º 5 (maio de 1994): 530e—530. http://dx.doi.org/10.21273/hortsci.29.5.530e.
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A problem in immunocytochemistry is obtaining acceptable fixation of tissue while retaining antigenicity. Two concentrations (1% and 2.5%) of glutaraldehyde, with and without secondary fixation in 1% Osmium Tetroxide (OsO4) and varying fixation times were used. Fixation in 1% glutanddehyde for 3 h was adequate to preserve the tissue. Some loss of fine structure was visible under an electron microscope. A solution of 2.5% glutaraldehyde was more effective in preserving fine structure. At 2 h fixation the tissue was well preserved and only slight loss of tine detail was observed. A longer fixation results in better ultrastructural preservation, but can cause loss of antigenicity. OsO4 fixes lipids and acts as an electron dense stain. OsO4 has a negative effect on antigenicity. The use of OsO4 had little effect upon the preservation of ultrastructural detail and-did not improve staining; therefore, it was omitted in later fixations. Based on this experimental evidence, initial localization experiments will utilize tissue fixed in 1% glutaraldehyde for 3 h.
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Fischer, T., C. Schmid, M. Kompis, G. Mantokoudis, M. Caversaccio e W. Wimmer. "Effects of temporal fine structure preservation on spatial hearing in bilateral cochlear implant users". Journal of the Acoustical Society of America 150, n.º 2 (agosto de 2021): 673–86. http://dx.doi.org/10.1121/10.0005732.
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Tolstoy, A. "FINE-GRAINED HIGH-STRENGTH CONCRETE". Construction Materials and Products 3, n.º 1 (8 de julho de 2020): 39–43. http://dx.doi.org/10.34031/2618-7183-2020-3-1-39-43.
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the article discusses the possibilities of improving the strength characteristics of fine-grained concrete. Modification of compositions and production technology of fine-grained high-strength concrete is possible with the use of natural and man-made raw materials of various chemical and mineral composition. It is shown that it is possible to increase the economic feasibility of high-strength fine-grained concretes with the preservation of performance characteristics due to the use of man-made raw materials and production waste. The issues of controlling the processes of structure formation and identifying a potentially stable state of hardening compositions are considered, possibly on the basis of modification and design methods for the composition of construction objects with improved properties.
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Mastronarde, David, James Kremer, Eileen O’Toole, Mary Morphew, Mark Ladinsky e Richard McIntosh. "Resources for the Study of Cellular Structure by High Voltage Electron Tomography, Serial Thin Sectioning, Specific Labeling, and Image Analysis". Microscopy and Microanalysis 3, S2 (agosto de 1997): 273–74. http://dx.doi.org/10.1017/s1431927600008254.
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We are working to improve methods for the study of cellular fine structure. Our approach is to advance each of the key steps in the preparation of specimens for EM: high quality fixation that will preserve both structure and antigenicity; methods for specific labeling; efficient acquisition of 3-D electron microscopic data; and software for 3-D reconstruction and display.Our work on high quality structure preservation has focused on methods for fast freezing and freeze substitution. Both plunge freezing of specimens grown on coated gold grids and high pressure freezing of either cultured cells or tissue specimens have yielded well preserved material. These samples are suitable for freeze substitution fixation with either anhydrous aldehydes in acetone at -90°C, for the preservation of antigens, or aldehydes, tannic acid, OsO4, and uranyl acetate for optimal preservation the structure.We have used a JEOL JEM-1,000 high voltage microscope to image sections about 250nm thick, employing a goniometer stage to perform dual axis tomography for 3-D reconstruction with approximately isotropic resolution at ∼7nm.
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Yamaguchi, M., Y. Namiki, H. Okada, K. Uematsu, A. Tame, T. Maruyama e Y. Kozuka. "Improved preservation of fine structure of deep-sea microorganisms by freeze-substitution after glutaraldehyde fixation". Journal of Electron Microscopy 60, n.º 4 (13 de maio de 2011): 283–87. http://dx.doi.org/10.1093/jmicro/dfr032.
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Pancaningtyas, Sulistyani. "The evaluation of java fine flavor cocoa propagation through somatic embryogenesis technique for germplasm preservation". E3S Web of Conferences 306 (2021): 01056. http://dx.doi.org/10.1051/e3sconf/202130601056.
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Somatic embryogenesis is one of the newest technology that applied for the mass production of cocoa. This research aims to evaluate the regeneration rate of somatic embryos through somatic embryogenesis propagation techniques on java fine flavor cocoa. Cultivars in this study are ICCRI 01, ICCRI 02, DR 1, DR 2, DRC 16, DR 38, PNT 16, and PNT 30. Observations include parameters to determine the percentage of primary callus and embryogenic callus formation and the number of somatic embryos produced. Based on data, the ability of callus to produce primary embryos is highly dependent on plant cultivars and explant sources. Five cultivars showed a higher regeneration rate using explants from the petal part, while the rest showed a higher regeneration rate using explants from the staminode section. Embryogenic callus from each cacao cultivar has the same basic structure: a nodular friable structure consisting of many embryonic cells. Some fine flavor cacao cultivars that were able to produce callus and primary somatic embryos could not produce secondary somatic embryos and plantlets. However, two cultivars, which had low potential in producing primary embryos, had the high ability to produce secondary somatic embryos and develop into plantlets.
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Wu, Xi, Mingyuan Xie, Wei Wu e Jiliu Zhou. "Nonlocal Mean Image Denoising Using Anisotropic Structure Tensor". Advances in Optical Technologies 2013 (12 de fevereiro de 2013): 1–6. http://dx.doi.org/10.1155/2013/794728.
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We present a novel nonlocal mean (NLM) algorithm using an anisotropic structure tensor to achieve higher accuracy of imaging denoising and better preservation of fine image details. Instead of using the intensity to identify the pixel, the proposed algorithm uses the structure tensor to characterize the boundary information around the pixel more comprehensively. Meanwhile, similarity of the structure tensor is computed in a Riemannian space for more rigorous comparison, and the similarity weight of the pixel (or patch) is determined by the intensity and structure tensor simultaneously. The proposed algorithm is compared with the original NLM algorithm and a modified NLM algorithm that is based on the principle component analysis. Quantitative and qualitative comparisons of the three NLM algorithms are presented as well.
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Uderbayeva, Assemgul, Ayaulym Rakhmatulina e Gulzira Nurakhmetova. "Selection of Rational Deformation Pressing Modes in a Special Device". Solid State Phenomena 316 (abril de 2021): 319–23. http://dx.doi.org/10.4028/www.scientific.net/ssp.316.319.
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Various types of deformed semi-finished products are prepared from aluminum alloys, such as plates, sheets, tapes, foil, panels, profiles, pipes, rods, forged pieces, wires. These semi-finished products are obtained by processing ingots of continuous casting by pressure - rolling, rolling-off, pressing, forging, stamping or drawing. Pressed semi-finished products are made of aluminum alloys in the majority of cases. The work examines the study of the evolution of the half-finished products microstructure at different stages of their manufacturing in several passes and shows the possibility of obtaining strips of fine-grained structure using pressing in a special device. Also, the research established that, in the material of half-finished product from the AD31 aluminum alloy the smooth fine-grained structure is formed with grains of 6 - 17 μm, which leads to an increase in the strength properties of the alloy and to a preservation of good plasticity.
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McDonald, Kent L. "Combining Cryo and Conventional Specimen Preparation Methods to Improve the Preservation of Cell Ultrastructure". Microscopy and Microanalysis 6, S2 (agosto de 2000): 308–9. http://dx.doi.org/10.1017/s1431927600034036.
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Poor specimen preparation techniques affect all subsequent EM imaging operations, whether simple descriptions or sophisticated computer reconstruction and analysis. Therefore, EM researchers continue to put effort into developing methods that will preserve the fine structure of the cell as close to the native state as possible. Much attention has been paid to the primary or initial fixation because this is probably the singlemost important step in EM processing. Evidence from a variety of sources. shows that cryofixation is more likely to give good preservation than conventional chemical fixation for most cell types. Among the choices for cryofixation, high pressure freezing is probably the best for most samples, even those that are small enough to be frozen by other means.Dehydration is another key point in processing where high resolution structure can be lost or distorted, though it has received relatively little attention compared to primary fixation.
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Vil'k, M. F., O. S. Sachkova, L. A. Levanchuk e E. O. Latynin. "Peculiarities in assessing occupational health risks for workers who are in contact with aerosols containing fine-dispersed dust particles". Health Risk Analysis, n.º 4 (dezembro de 2020): 106–12. http://dx.doi.org/10.21668/health.risk/2020.4.12.eng.
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In Russia there is a system for standardizing and control over aerosols with predominantly fibrogenic effects and dust particles with different structure. But at the same time there are no hygienic standards for fine-dispersed dust contents in working area air and it makes hygienic assessment of working conditions more complicated and impedes use of risk assessment methodology. Our research goal was to substantiate a concentration of aerosols containing fine-dispersed dust particles (РМ10 и РМ2.5) in working are air that were harmless for workers’ health. It was done via applying a procedure for determining dust burden and using it when calculating health risks for workers. We assessed dust content in working area air with focus on fine-dispersed dust particles РМ10 и РМ2.5 with a dust measuring device «OMPN-10.0». Chemical structure of dust particles was determined with atomic absorption procedure. Results were estimated according to HS 2.2.5.3532-18. Dust burden was calculated according to State standard GOST R 54578-2011. We established dependence between duration of working experience under exposure to fine-dispersed dust that was harmless for health and a value of excess in dust contents over the suggested concentration and work shift duration. To assess health risk for workers caused by exposure to fine-dispersed dust particles taking their chemical structure into account, we determined reference concentrations for working area air; 0.1 mg/m3 for РМ10, and 0.055 mg/m3 for РМ2.5. Use of calculated concentrations allowed suggesting models for calculating harmless duration of working experience under exposure to dusts in concentrations higher than recommended ones. The results enable substantiating organizational activities aimed at workers’ health preservation.
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Vil'k, M. F., O. S. Sachkova, L. A. Levanchuk e E. O. Latynin. "Peculiarities in assessing occupational health risks for workers who are in contact with aerosols containing fine-dispersed dust particles". Health Risk Analysis, n.º 4 (dezembro de 2020): 106–12. http://dx.doi.org/10.21668/health.risk/2020.4.12.
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In Russia there is a system for standardizing and control over aerosols with predominantly fibrogenic effects and dust particles with different structure. But at the same time there are no hygienic standards for fine-dispersed dust contents in working area air and it makes hygienic assessment of working conditions more complicated and impedes use of risk assessment methodology. Our research goal was to substantiate a concentration of aerosols containing fine-dispersed dust particles (РМ10 и РМ2.5) in working are air that were harmless for workers’ health. It was done via applying a procedure for determining dust burden and using it when calculating health risks for workers. We assessed dust content in working area air with focus on fine-dispersed dust particles РМ10 и РМ2.5 with a dust measuring device «OMPN-10.0». Chemical structure of dust particles was determined with atomic absorption procedure. Results were estimated according to HS 2.2.5.3532-18. Dust burden was calculated according to State standard GOST R 54578-2011. We established dependence between duration of working experience under exposure to fine-dispersed dust that was harmless for health and a value of excess in dust contents over the suggested concentration and work shift duration. To assess health risk for workers caused by exposure to fine-dispersed dust particles taking their chemical structure into account, we determined reference concentrations for working area air; 0.1 mg/m3 for РМ10, and 0.055 mg/m3 for РМ2.5. Use of calculated concentrations allowed suggesting models for calculating harmless duration of working experience under exposure to dusts in concentrations higher than recommended ones. The results enable substantiating organizational activities aimed at workers’ health preservation.
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Vil'k, M. F., O. S. Sachkova, L. A. Levanchuk e E. O. Latynin. "Peculiarities in assessing occupational health risks for workers who are in contact with aerosols containing fine-dispersed dust particles". Health Risk Analysis, n.º 4 (dezembro de 2020): 106–12. http://dx.doi.org/10.21668/health.risk/2020.4.12.eng.
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In Russia there is a system for standardizing and control over aerosols with predominantly fibrogenic effects and dust particles with different structure. But at the same time there are no hygienic standards for fine-dispersed dust contents in working area air and it makes hygienic assessment of working conditions more complicated and impedes use of risk assessment methodology. Our research goal was to substantiate a concentration of aerosols containing fine-dispersed dust particles (РМ10 и РМ2.5) in working are air that were harmless for workers’ health. It was done via applying a procedure for determining dust burden and using it when calculating health risks for workers. We assessed dust content in working area air with focus on fine-dispersed dust particles РМ10 и РМ2.5 with a dust measuring device «OMPN-10.0». Chemical structure of dust particles was determined with atomic absorption procedure. Results were estimated according to HS 2.2.5.3532-18. Dust burden was calculated according to State standard GOST R 54578-2011. We established dependence between duration of working experience under exposure to fine-dispersed dust that was harmless for health and a value of excess in dust contents over the suggested concentration and work shift duration. To assess health risk for workers caused by exposure to fine-dispersed dust particles taking their chemical structure into account, we determined reference concentrations for working area air; 0.1 mg/m3 for РМ10, and 0.055 mg/m3 for РМ2.5. Use of calculated concentrations allowed suggesting models for calculating harmless duration of working experience under exposure to dusts in concentrations higher than recommended ones. The results enable substantiating organizational activities aimed at workers’ health preservation.
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Tomiyasu, K., F. Nasu, H. Igarashi e K. Inomata. "Stereoscopic observation of enzyme distribution in lowicryl K4M-embedded specimens by conventional electron microscopy." Journal of Histochemistry & Cytochemistry 38, n.º 4 (abril de 1990): 595–99. http://dx.doi.org/10.1177/38.4.2156924.
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The present investigation was undertaken to explore the value of the Lowicryl K4M embedding technique for enzyme histochemical examination of semi-thin sections. The low-temperature embedding procedure with Lowicryl K4M was found to provide favorable conditions for preservation of enzyme activity in tissue samples. We tested the histological effects of various fixatives; the best results were obtained using 4% paraformaldehyde when testing for AcPase, AlPase, TPPase, and Mg-ATPase in the dorsal root ganglion. The three-dimensional cellular fine structure could be clearly seen in stereo pair pictures under stereoscopy.
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Grant, Kenneth, e W. Gray Jerome. "Laser Capture Microdissection as an Aid to Ultrastructural Analysis". Microscopy and Microanalysis 8, n.º 3 (junho de 2002): 170–75. http://dx.doi.org/10.1017/s143192760202010x.
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Laser capture microdissection uses a microscope to identify specific cells for microdissection and then a laser-sensitive plastic to capture and remove the cells from their substrate. This efficient capture method was originally developed to capture cells for genetic analysis. However, it has also been used to capture cells for proteonomic analysis. In this article, we extend the uses of laser-capture microdissection by reporting a method for preparing captured cells for ultrastructural analysis by transmission electron microscopy. Cells prepared by our methodology show good fine structure preservation and are easily sectioned by standard ultramicrotomy.
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Kim, Hee-Eun, Seong-Hyeon Kang, Kyuseok Kim e Youngjin Lee. "Total Variation-Based Noise Reduction Image Processing Algorithm for Confocal Laser Scanning Microscopy Applied to Activity Assessment of Early Carious Lesions". Applied Sciences 10, n.º 12 (13 de junho de 2020): 4090. http://dx.doi.org/10.3390/app10124090.
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The confocal laser scanning microscopy (CLSM) system has been widely used to analyze early carious lesions with fluorescent ligands in dental imaging. This system can be used to examine the physiological condition of cellular colonization in the tooth structure. However, the undesirable noise in CLSM images hinders accurate activity assessment of early carious lesions. To address this limitation, a total variation (TV)-based noise reduction algorithm with good edge preservation was developed, and its applicability to medical tooth specimen images obtained with CLSM was verified. To evaluate the imaging performance, the proposed algorithm was compared with conventional filtering methods in terms of the normalized noise power spectrum, contrast-to-noise ratio, and coefficient of variation. The results indicate that the proposed algorithm achieved better noise performance and fine-detail preservation, in comparison with the conventional methods.
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Fehrenbach, H., D. Riemann, T. Wahlers, S. W. Hirt, A. Haverich e J. Richter. "Scanning and Transmission Electron Microscopy of Human Donor Lungs: Fine Structure of the Pulmonary Parenchyma following Preservation and Ischemia". Cells Tissues Organs 151, n.º 4 (1994): 220–31. http://dx.doi.org/10.1159/000147667.
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Minda, J. M., I. Lubensky e G. G. Pietra. "The Use of Noncryoprotected Frozen Tissue in Diagnostic Electron Microscopic Pathology". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 3 (12 de agosto de 1990): 230–31. http://dx.doi.org/10.1017/s0424820100158698.
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Aldehyde fixatives are the reagents of choice to preserve human tissues for diagnostic electron microscopic examination. Since the need for ultrastructural studies is often unanticipated at the time of frozen sections, tissues are not routinely fixed in aldehydes. Alternatively, even if properly fixed, the sample may not contain representative lesions. This may require retrieval of tissue for electron microscopy from paraffin-embedded blocks or slides in which preservation of fine structure is markedly inadequate.The present study was undertaken to evaluate the use of noncryoprotected frozen tissue for diagnostic electron microscopic evaluation. The tissues samples from the following lesions were available for study: bronchial carcinoid, duodenal somatostatinoma, granular cell tumor of breast, interstitial myocarditis (from an autopsy). The effect of the rapidity of freezing on ultrastructural preservation was studied in a normal rat liver. Each case had its own control in companion samples that had been routinely fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M sodium cacodylate, pH = 7.4, (Karnovsky’s fixative).
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Wu, Long, Yi Long Zhao, Rong Fa Chen, Hua Yang, Qing Qing Li, Zhi Long Li e Hua Feng Lu. "Effect of Foaming Temperature and Holding Time on Foam Glass". Advanced Materials Research 712-715 (junho de 2013): 897–900. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.897.
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In the paper, the effects of the foaming temperature and holding time on the quality of the foam glass were investigated by means of the different foaming technology. The results indicated that lots of the defects, such as the non-uniform size of the bubbles, big hole and the pit at the bottom, were caused by the high foaming temperature. The fine pore structure was formed by the low temperature. The molding and properties of the foaming glass was affected by the length of the heat preservation time. The rate of acceptability and the mechanical property of the foam glass can be effectively improved by the optimized foaming technology.
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Marchello, G., R. Giovanelli, E. Fontana, F. Cannella e A. Traviglia. "CULTURAL HERITAGE DIGITAL PRESERVATION THROUGH AI-DRIVEN ROBOTICS". International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-M-2-2023 (24 de junho de 2023): 995–1000. http://dx.doi.org/10.5194/isprs-archives-xlviii-m-2-2023-995-2023.
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Abstract. This paper introduces a novel methodology developed for creating 3D models of archaeological artifacts that reduces the time and effort required by operators. The approach uses a simple vision system mounted on a robotic arm that follows a predetermined path around the object to be reconstructed. The robotic system captures different viewing angles of the object and assigns 3D coordinates corresponding to the robot's pose, allowing it to adjust the trajectory to accommodate objects of various shapes and sizes. The angular displacement between consecutive acquisitions can also be fine-tuned based on the desired final resolution. This flexible approach is suitable for different object sizes, textures, and levels of detail, making it ideal for both large volumes with low detail and small volumes with high detail. The recorded images and assigned coordinates are fed into a constrained implementation of the structure-from-motion (SfM) algorithm, which uses the scale-invariant features transform (SIFT) method to detect key points in each image. By utilising a priori knowledge of the coordinates and SIFT algorithm, low processing time can be ensured while maintaining high accuracy in the final reconstruction.The use of a robotic system to acquire images at a pre-defined pace ensures high repeatability and consistency across different 3D reconstructions, eliminating operator errors in the workflow. This approach not only allows for comparisons between similar objects but also provides the ability to track structural changes of the same object over time.Overall, the proposed methodology provides a significant improvement over current photogrammetry techniques by reducing the time and effort required to create 3D models while maintaining a high level of accuracy and repeatability.
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Quiñones-Pérez, C. Z., S. L. Simental-Rodríguez, C. Sáenz-Romero, J. P. Jaramillo-Correa e C. Wehenkel. "Spatial genetic structure in the very rare and species-rich Picea chihuahuana tree community (Mexico)". Silvae Genetica 63, n.º 1-6 (1 de dezembro de 2014): 149–58. http://dx.doi.org/10.1515/sg-2014-0020.
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Abstract In natural plant populations, the spatial genetic structure (SGS) is occasionally associated with evolutionary and ecological features such as the mating system, individual fitness, inbreeding depression and natural selection of the species of interest. The very rare Mexican P. chihuahuana tree community covers an area no more than 300 ha and has been the subject of several studies concerning its ecology and population genetics. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. However, analysis of the fine-scale SGS in this special forest tree community has not yet been conducted, which might help enrich the above mentioned conservation programs. In this study, we examined the SGS of this community, mostly formed by P. chihuahuana Martínez, Pinus strobiformis Ehrenberg ex Schlechtendah, Pseudotsuga menziesii (Mirb.) Franco, and Populus tremuloides Michx, in 14 localities at both the fine and large scales, with the aim of obtaining a better understanding of evolutionary processes. We observed a non-significant autocorrelation in fine-scale SGS, suggesting that the genetic variants of all four tree species are randomly distributed in space within each sampled plot of 50 x 50 m. At the larger scale, the autocorrelation was highly significant for P. chihuahuana and P. menziesii, probably as a result of insufficient gene flow due to the extreme population isolation and small sizes. For these two species our results provided strong support for the theory of isolation by distance.
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Tomašových, Adam, e Susan M. Kidwell. "Preservation of spatial and environmental gradients by death assemblages". Paleobiology 35, n.º 1 (2009): 119–45. http://dx.doi.org/10.1666/07081.1.
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Although only a few studies have explicitly evaluated live-dead agreement of species and community responses to environmental and spatial gradients, paleoecological analyses implicitly assume that death assemblages capture these gradients accurately. We use nine data sets from modern, relatively undisturbed coastal study areas to evaluate how the response of living molluscan assemblages to environmental gradients (water depth and seafloor type; “environmental component” of a gradient) and geographic separation (“spatial component”) is captured by their death assemblages. We find that:1. Living assemblages vary in composition either in response to environmental gradients alone (consistent with a species-sorting model) or in response to a combination of environmental and spatial gradients (mass-effect model). None of the living assemblages support the neutral model (or the patch-dynamic model), in which variation in species abundance is related to the spatial configuration of stations alone. These findings also support assumptions that mollusk species consistently differ in responses to environmental gradients, and suggest that in the absence of postmortem bias, environmental gradients might be accurately captured by variation in species composition among death assemblages. Death assemblages do in fact respond uniquely to environmental gradients, and show a stronger response when abundances are square-root transformed to downplay the impact of numerically abundant species and increase the effect of rare species.2. Species' niche positions (position of maximum abundance) along bathymetric and sedimentary gradients in death assemblages show significantly positive rank correlations to species positions in living assemblages in seven of nine data sets (both square-root-transformed and presence-absence data).3. The proportion of compositional variation explained by environmental gradients in death assemblages is similar to that of counterpart living assemblages. Death assemblages thus show the same ability to capture environmental gradients as do living assemblages. In some instances compositional dissimilarities in death assemblages show higher rank correlation with spatial distances than with environmental gradients, but spatial structure in community composition is mainly driven by spatially structured environmental gradients.4. Death assemblages correctly identify the dominance of niche metacommunity models in mollusk communities, as revealed by counterpart living assemblages. This analysis of the environmental resolution of death assemblages thus supports fine-scale niche and paleoenvironmental analyses using molluscan fossil records. In spite of taphonomic processes and time-averaging effects that modify community composition, death assemblages largely capture the response of living communities to environmental gradients, partly because of redundancy in community structure that is inherently associated with multispecies assemblages. The molluscan data sets show some degree of redundancy as evidenced by the presence of at least two mutually exclusive subsets of species that replicate the community structure, and simple simulations show that between-sample relationships can be preserved and remain significant even when a large proportion of species is randomly removed from data sets.
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Devyatkina, T. I., R. V. Taranets, V. V. Rogozhin e V. V. Isaev. "The influence of the structure of azo compounds on the deposition process and the quality of copper coatings on Anodized aluminum alloys". Perspektivnye Materialy 3 (2023): 64–74. http://dx.doi.org/10.30791/1028-978x-2023-3-64-74.
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A comparative analysis of the influence of the structure of azo compounds (on the example of methyl red (MKR) and nitroso-p-salt (NRS)) was carried out during copper plating of anodized aluminum alloys, on the microstructure, micro-roughness and quality of deposited copper coatings. It is shown that the choice of azo dye significantly depends on the charge of the surface of the oxide film in the solutions used. It is shown that the dyes used should have at least two functional groups in their composition, one of which should ensure the formation of complexes with copper ions, and the other – their adhesion to the surface of the oxide film due to the forces of electrostatic interaction. The adsorption of azo compounds changes the structure of the double electric layer at the film – electrolyte interface, which affects the speed of the copper plating process. At the same time, the mobility of the formed complexes in the adsorption layer increases, which leads to a better opening of the film surface. The studied indicators (dyes) positively affected the structure of the copper coating (eliminated defects and made it fine-crystalline), and also significantly smoothed the surface of the copper coating. The advantage of using the NRS over the MKR was revealed, which allowed not only to obtain a high-quality coating, but also to significantly intensify the copper plating process. A new composition of copper sulfuric acid electrolyte for coating anodized aluminum alloys at elevated cathode current densities with preservation of fine-crystalline structure and smoothed surface is proposed.
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Catbas, F. Necati, Jacob Anthony Cano, Furkan Luleci, Lori C. Walters e Robert Michlowitz. "On the Generation of Digital Data and Models from Point Clouds: Application to a Pedestrian Bridge Structure". Infrastructures 9, n.º 1 (25 de dezembro de 2023): 6. http://dx.doi.org/10.3390/infrastructures9010006.
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This study investigates the capture of digital data and the development of models for structures with incomplete documentation and plans. LiDAR technology is utilized to obtain the point clouds of a pedestrian bridge structure. Two different point clouds with varying densities, (i) fine (11 collection locations) and (ii) coarse (4 collection locations), collected via terrestrial LiDAR, are analyzed to generate geometry and structural sections. This geometry is compared to the structural plans, which are then converted into numerical models (finite element—FE model) based on the point cloud data. Point cloud-based FE models (based on fine and coarse data) are compared with the structural plan-based FE model. It is observed that the static and dynamic responses are comparable within an acceptable range of a maximum difference of 5.5% for static deformation and an 8.23% frequency difference, with an average difference of less than 5%. Additionally, the dynamic properties of the fine and coarse point cloud FE models are compared with the operational modal analysis data obtained from the bridge. The fine and course point-cloud-based FE models, without model calibration, achieve an average accuracy of 8.76% and 9.94% for natural frequencies and a 0.89 modal assurance criterion value. The research found that the digital data generation yields promising results in this case for a bridge if documentation or plans are unavailable. With recent technologies and approaches such as digital twins, the connection between physical and virtual entities needs to be established by fusing digital models, sensorial information, and other data forms for better infrastructure management. Models such as those investigated and discussed in this paper can assist engineers with structural preservation in conjunction with monitoring data and utilization for digital twins.
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Petrenko, Iaroslav, Adam P. Summers, Paul Simon, Sonia Żółtowska-Aksamitowska, Mykhailo Motylenko, Christian Schimpf, David Rafaja et al. "Extreme biomimetics: Preservation of molecular detail in centimeter-scale samples of biological meshes laid down by sponges". Science Advances 5, n.º 10 (outubro de 2019): eaax2805. http://dx.doi.org/10.1126/sciadv.aax2805.
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Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale samples. The fine-scale structure of this collagenous resource is stable at temperatures of up to 1200°C and can produce up to 4 × 10–cm–large 3D microfibrous and nanoporous turbostratic graphite. Our findings highlight the fact that this turbostratic graphite is exceptional at preserving the nanostructural features typical for triple-helix collagen. The resulting carbon sponge resembles the shape and unique microarchitecture of the original spongin scaffold. Copper electroplating of the obtained composite leads to a hybrid material with excellent catalytic performance with respect to the reduction of p-nitrophenol in both freshwater and marine environments.
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Jeung, Do-Gak, Tae-Hyun Kim e Jae-Min Oh. "Homogeneous Incorporation of Gallium into Layered Double Hydroxide Lattice for Potential Radiodiagnostics: Proof-of-Concept". Nanomaterials 11, n.º 1 (26 de dezembro de 2020): 44. http://dx.doi.org/10.3390/nano11010044.
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Trivalent gallium ion was successfully incorporated into chemically well-defined MgAl-layered double hydroxide (LDH) frameworks through postsynthetic hydrothermal treatment. Quantitative analysis with inductively coupled plasma-mass spectroscopy exhibited that Ga3+ was first incorporated into LDH through partial dissolution-precipitation at the edge of LDH particle and homogeneously distributed throughout the particle by substitution of Ga3+ for Al3+ in LDH frame works. The powder X-ray diffraction patterns showed that the Ga3+ incorporation did not affect the crystal structure without evolution of unexpected impurities. The morphology and surface property of LDH evaluated by scanning electron microscopy and light scattering showed the preservation of physicochemical properties throughout 24 h of hydrothermal reaction. The distribution of incorporated Ga3+ was visualized with energy dispersive spectroscopy-assisted transmission electron microscopy, suggesting the homogeneous location of Ga3+ in an LDH particle. The X-ray absorption near-edge structure and extended X-ray absorption fine structure suggested that the Ga moiety was immobilized in LDH from 0.5 h and readily crystallized upon reaction time.
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Grewal, J. S., V. C. Kapoor e J. Kochar. "Electron Microscopic study of dipteran Halteres by using preserved specimens". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 3 (12 de agosto de 1990): 758–59. http://dx.doi.org/10.1017/s0424820100161357.
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Halteres, highly specialized metathoracic wings are the balancing organs in Diptera. This is probably an adaptation for aerial swarming. Our understanding regarding the detailed structure of this organ is very little. An effort has been made to study the ultrastructure of halteres and the functional aspects of various parts have been discussed.Flies are relaxed in relaxing medium (Watkins and Doncaster Hawkhurst, England) or by keeping overnight in 50% ethanol. Halteres alongwith a little of thorax lateral wall are peeled off with the help of fine and sharp scalpel. These are boiled in distilled water for about 20 minutes to get rid off all the distortion of structure due to preservation. A fungal growth observed on the material is cleared off by putting a drop or two of phenol in boiling water. Material is then subjected to sonication in distilled water to remove any foreign particle adhering to halteres. Then the material is dehydrated by passing through ethanol series.
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Kareva, N. T. "Influence of technological heating used in the manufacture of parts on the initial structure of 10G2FBYu steel after controlled rolling". Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 79, n.º 5 (26 de junho de 2023): 381. http://dx.doi.org/10.32339/0135-5910-2023-5-381-390.
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Modern pipe steels for the main pipelines belong are of the high-strength class of X70 and higher. The steels must simultaneously still have sufficient viscosity at low operating temperatures, hardenability and good weldability. This set of properties is achieved by combining the optimal material composition and the method of manufacturing a sheet billet using controlled rolling. Subsequent operations for the manufacture of pipes, connecting parts of oil and gas pipelines (welding, heat treatment, etc.), accompanied by inevitable high-temperature heating, can significantly affect the initial structure of the sheet and the level of its properties. In this case, the possible growth of austenite and ferrite grains, as well as the loss of hot work hardening, should negative effect the mechanical properties of pipe steel. However, taking into account the peculiarities of the chemical composition and structure of sheet pipe steels subjected to controlled rolling, containing hardly soluble fine particles of carbides and carbonitrides based on vanadium, niobium, titanium, which inhibit recrystallization, one can expect the preservation of a fine-grained structure and a part of hot work hardening with a rational scheme for manufacturing parts. The article presents data on the study of the structure and hardness of low-carbon low-alloy steel 10G2FBYu of strength class K60 after repeated normalization from temperatures of 850, 880, 910 and 940°C. Structural studies performed using metallographic and electron microscopes Carl Zeiss Axio Observer and JEOL JSM-7001F showed that after additional heating at the indicated temperatures, the grain sizes increase, but not significantly. The hardness of steel is reduced by 20% or less, depending on the normalization mode
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Hassan, Raaid N. "A comparison between PCA and some enhancement filters for denoising astronomical images". Iraqi Journal of Physics (IJP) 11, n.º 22 (20 de fevereiro de 2019): 82–92. http://dx.doi.org/10.30723/ijp.v11i22.356.
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This paper includes a comparison between denoising techniques by using statistical approach, principal component analysis with local pixel grouping (PCA-LPG), this procedure is iterated second time to further improve the denoising performance, and other enhancement filters were used. Like adaptive Wiener low pass-filter to a grayscale image that has been degraded by constant power additive noise, based on statistics estimated from a local neighborhood of each pixel. Performs Median filter of the input noisy image, each output pixel contains the Median value in the M-by-N neighborhood around the corresponding pixel in the input image, Gaussian low pass-filter and Order-statistic filter also be used.
Experimental results shows LPG-PCA method gives better performance, especially in image fine structure preservation, compared with other general denoising algorithms.
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Hagino, Masahiro, Takashi Inoue, A. G. Olabi, Wataru Aoki e Fumiaki Matsumoto. "New Machine Tool on Collecting Cutting Chips of CFRP for Working Environment Improvement". Advanced Materials Research 816-817 (setembro de 2013): 211–15. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.211.
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In machining to CFRP material has many important problems, about necessary of high-precision machining, improvement of tool life and dispose of cutting chips etc. Especially in case of twist drill almost cant collect under 0.5 μm cutting chip, the fine-cutting chips diffuse into the sliding table and spindle head with the machine. Moreover, the fine-cutting chip is mixed and diffuse into the atmosphere. The possibility to remarkable decline of working efficiency so the dust-collection provision technology is wished. It is important also from the viewpoint of keep safety of a worker and work environment preservation because the CFRP utilizes in market for industrial structure materials, is increasing. As one method of solving this problem which aspirates and ejects cutting chip from a penetration hole through outside in the central part of the drill shank the new tool and cyclone type dust-collection system were developed. These technologies were used for perforate of CFRP material, and investigated about the cutting characteristic of the hollow type drill, and the effect of work environment improvement to dust-collection performance of cutting chips. As the result, our development machine tool and cutting tool can collect approximate 99.5% cutting chip.
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Yuan, Yuan, Yue Tang, Lihua Tong, Daiyong Cao, Yingchun Wei e Caiqin Bi. "Porosity Characteristics of Coal Seams and the Control Mechanisms of Coal Petrology in the Xishanyao Formation in the Western Part of the Southern Junggar Basin". Minerals 14, n.º 6 (24 de maio de 2024): 543. http://dx.doi.org/10.3390/min14060543.
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The porosity characteristics of coal seams serve as a pivotal factor in assessing the development potential of coalbed methane (CBM) resources, significantly influencing the adsorption and permeability capabilities of coal reservoirs, as well as the accumulation, entrapment, and preservation of CBM. In this study, we focused on the coal seams of the Xishanyao Formation in the western part of the southern Junggar Basin (NW China). By leveraging the complementarity of nuclear magnetic resonance (NMR), low-temperature liquid nitrogen experiments, and high-pressure mercury intrusion porosimetry (MIP) in spatial exploration range and precision, we conducted a comprehensive analysis to achieve a fine description of porosity characteristics. Furthermore, we explored the coal petrology factors controlling the pore characteristics of the Xishanyao Formation, aiming to provide geological evidence for the selection of favorable areas and the development potential evaluation of CBM in the study area. The results indicate the following: (1) The total pore volume of the coal samples is 6.318 × 10−3 cm3/g on average, and the micropore volume accounts for a relatively high proportion (averaging 44.17%), followed by the fine pores (averaging 39.41%). The average porosity is approximately 3.87%, indicating good gas storage and connectivity of the coal seams, albeit with some heterogeneity. The coal reservoir is dominated by micropores and fine pores with diameters less than 100 nm, and the pore structure is characterized by low pore volume and high pore area. (2) The pore structure is influenced by both the coalification degree and the coal maceral. Within the range of low coalification, porosity increases with the increase in coalification degree. Building upon this, an increase in the vitrinite content promotes the development of micropores and fine pores, while an increase in the inertinite content promotes the development of meso–macropores. The clay mineral content exhibits a negative correlation with the adsorption pore volume ratio and a positive correlation with the seepage pore volume ratio.
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Dong, En Tao, Wei Yu, Qing Wu Cai, Jia Xin Shi, Zhen Ning e Ze Yu Zhang. "Effects of Hot-Rolled Process and Heat Treatment on Microstructure and Mechanical Properties of Ti-6Al-4V ELI Alloy". Materials Science Forum 944 (janeiro de 2019): 73–78. http://dx.doi.org/10.4028/www.scientific.net/msf.944.73.
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The properties of titanium alloys significantly depend on the microstructure, which are correspond to the deformation conditions. However, because of its low thermal conductivity, sensitive to deformation temperature, narrow stable regions for hot working and structural heterogeneity, it does not achieve cosmically industrial production and application. In this paper, the effects of hot rolling deformation in single-phase (β) region, cross-phase region and heat treatment on the microstructure and mechanical properties of Ti-6Al-4V ELI alloy were systematically investigated. The relationship between microstructure and properties of alloy was also analyzed in order to a theoretical basis for the development of the rolling technology for the manufacture. The results indicated that hot rolling deformation in different region had significant effects on microstructure heterogeneity (the size and colony of α phase, lamellar microstructure of β transformed). It has been shown that fine and coarse lamellar α structure within grains and visible grain boundary α were characterized after the deformation above the β transformation temperature, which made high impact toughness. But in order to ensure in single phase region, the heat preservation method after passes of rolling may cause β grain coarsening (widmanstatten structure), leading to mechanical properties worsen. The fine crisscross substructures of α phase was obtained after deformation in cross-phase region, improving good mechanical properties. After solution treatment followed aging, the uniform type of microstructure was reached, which mainly displayed the change of contents and sizes of lamellar α phase.
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Berladir, K., T. Hovorun, M. Bondarenko e S. Vorobiov. "Application of Reinforcing Thermocycling Treatment for Materials of Stamps Hot Deformation". Journal of Engineering Sciences 6, n.º 2 (2019): c6—c10. http://dx.doi.org/10.21272/jes.2019.6(2).c2.
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The paper is devoted to the search for technological methods of increasing the resistance of the stamp tool for hot deformation. New non-standard combinations of cyclization schemes and parameters of thermocycling processing within the regime were developed. This is allowed the creation of managed structural states in the metal due to the grinding of grain, the creation of high density of defects, and the acceleration of diffusion processes to effectively manage the structure, increase the mechanical, operational properties and prevent the destruction of the working surfaces of the tool. New modes of thermocycling treatment, which have a positive effect on the mechanical characteristics of HNM5 steel, have been developed and tested. The conducted heat treatment in experimental modes, consisting of thermocycling treatment as a preliminary, quenching and tempering as the final, allows obtaining a more homogeneous structure with the preservation of fine grain and a given hardness. The grain size of the steel HNM5 structure after the use of thermocycling treatment decreases from 5–6 to 7–8 points, and after the final heat treatment – to 9–10 points. Keywords: stamp of hot deformation, thermocycling treatment, strength, relative narrowing, thermal resistance.
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Mattiello, Sara, Alessandro Guzzini, Alessandra Del Giudice, Carlo Santulli, Marco Antonini, Giulio Lupidi e Roberto Gunnella. "Physico-Chemical Characterization of Keratin from Wool and Chicken Feathers Extracted Using Refined Chemical Methods". Polymers 15, n.º 1 (30 de dezembro de 2022): 181. http://dx.doi.org/10.3390/polym15010181.
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In this work, the characteristic structure of keratin extracted from two different kinds of industrial waste, namely sheep wool and chicken feathers, using the sulfitolysis method to allow film deposition, has been investigated. The structural and microscopic properties have been studied by means of scanning electron microscopy (SEM), Raman spectroscopy, atomic force microscopy (AFM), and infrared (IR) spectroscopy. Following this, small-angle X-ray scattering (SAXS) analysis for intermediate filaments has been performed. The results indicate that the assembly character of the fiber can be obtained by using the most suitable extraction method, to respond to hydration, thermal, and redox agents. The amorphous part of the fiber and medium range structure is variously affected by the competition between polar bonds (reversible hydrogen bonds) and disulfide bonds (DB), the covalent irreversible ones, and has been investigated by using fine structural methods such as Raman and SAXS, which have depicted in detail the intermediate filaments of keratin from the two different animal origins. The preservation of the secondary structure of the protein obtained does offer a potential for further application of the waste-obtained keratin in polymer films and, possibly, biocomposites.
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Pan, Zhiqiang, Yingchun Kuang, Jianmei Lan e Lizhuo Zhang. "High-Precision Image Editing via Dual Attention Control in Diffusion Models Without Fine-Tuning". Applied Sciences 15, n.º 3 (22 de janeiro de 2025): 1079. https://doi.org/10.3390/app15031079.
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Existing diffusion models outperform generative models like Generative Adversarial Networks in image synthesis and editing. However, they struggle with high-precision image editing while preserving image details and the accuracy of editing instructions. To address these challenges, we propose a dual attention control method to achieve high-precision image editing. Our approach includes two key attention control modules: (1) cross-attention control module, which combines the cross-attention maps of the original and edited images through weighted parameters, ensures that the synthesized edited image retains the structure of the input image. (2) Self-attention control module, which varies based on the editing task, applied at “coarse” and “fine” layers, since the coarse layers help maintain input image details and the fine layers are better suited for style transformations. Experimental evaluations have demonstrated that our approach achieves excellent results in detail preservation, content consistency, visual realism, and semantic understanding, making it especially suitable for tasks requiring high-precision editing. Specifically, compared to the editing outcomes under no control conditions, the introduction of dual visual attention control has led to an increase of 6.19% in CLIP scores, a reduction of 29.3% in LPIPS, and a decrease of 24.7% in FID. These significant improvements not only validate the effectiveness of the dual attention control but also attest to the method’s substantial flexibility and adaptability across different scenarios. Notably, our approach is a zero-shot solution, requiring no user optimization or fine-tuning, facilitating real-world applications.
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Wielstra, Ben, e Jan W. Arntzen. "Extensive cytonuclear discordance in a crested newt from the Balkan Peninsula glacial refugium". Biological Journal of the Linnean Society 130, n.º 3 (28 de maio de 2020): 578–85. http://dx.doi.org/10.1093/biolinnean/blaa062.
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Abstract Integration of multilocus data and species distribution modelling into phylogeography allows mitochondrial DNA (mtDNA)-based scenarios to be fine-tuned. We address the question of whether extensive mtDNA substructuring in the crested newt Triturus macedonicus from the Balkan Peninsula is matched in the nuclear genome. We determine the intraspecific population structure based on 52 nuclear DNA markers and project a species distribution model on climate layers for the Last Glacial Maximum. We show that T. macedonicus accumulated nuclear DNA population structure in an area predicted to have been climatically stable during the Pleistocene, with four nuclear DNA groups in the western part of the species range. The distribution of these nuclear DNA groups shows little agreement with that of mtDNA structuring, which shows three highly distinct species-specific clades and a fourth one introgressed from another crested newt species. This cytonuclear discordance conveys that historical biogeographical scenarios based on mtDNA exclusively should be interpreted with caution. Our findings further highlight the important role the Balkan Peninsula has played in the evolution and preservation of European biodiversity.
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Hong, SeungHoo, Juhun Lee e Simon S. Woo. "All but One: Surgical Concept Erasing with Model Preservation in Text-to-Image Diffusion Models". Proceedings of the AAAI Conference on Artificial Intelligence 38, n.º 19 (24 de março de 2024): 21143–51. http://dx.doi.org/10.1609/aaai.v38i19.30107.
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Text-to-Image models such as Stable Diffusion have shown impressive image generation synthesis, thanks to the utilization of large-scale datasets. However, these datasets may contain sexually explicit, copyrighted, or undesirable content, which allows the model to directly generate them. Given that retraining these large models on individual concept deletion requests is infeasible, fine-tuning algorithms have been developed to tackle concept erasing in diffusion models. While these algorithms yield good concept erasure, they all present one of the following issues: 1) the corrupted feature space yields synthesis of disintegrated objects, 2) the initially synthesized content undergoes a divergence in both spatial structure and semantics in the generated images, and 3) sub-optimal training updates heighten the model's susceptibility to utility harm. These issues severely degrade the original utility of generative models. In this work, we present a new approach that solves all of these challenges. We take inspiration from the concept of classifier guidance and propose a surgical update on the classifier guidance term while constraining the drift of the unconditional score term. Furthermore, our algorithm empowers the user to select an alternative to the erasing concept, allowing for more controllability. Our experimental results show that our algorithm not only erases the target concept effectively but also preserves the model’s generation capability.
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Chashechkin, Yu D. "Evolution of the fine structure of the pattern of the distribution of a substance of the free-fall droplet in mixing liquids". Известия Российской академии наук. Физика атмосферы и океана 55, n.º 3 (20 de junho de 2019): 67–77. http://dx.doi.org/10.31857/s0002-351555367-77.
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The evolution of the pattern of the substance of a drop of ink falling freely into quiet water in the mode of formation of a cumulative back jet stream was traced by high-speed video recording. In the phase of primary contact and coalescence, the pigment of the drops merging with the targeted fluid is distributed in the form of fine fibers (ligaments), which form a regular striped pattern on the surface of the growing crown, and a net pattern consisting of three-, four- and pentagonal cells at the bottom of the cavity. The fibrous distributions of the substance droplets was saved at all subsequent stages of the evolution of the flow until the formation of a cascade of vortices, after which the picture is blurred by the processes of molecular diffusion in a practically quiescent liquid. The formation of a discrete (fibrous) pattern of the distribution of the substance of a drop is associated with the compactness of the region of release of the available potential surface energy during the confluence of liquids, which initiates a fast movement of a thin layer. Subsequent preservation of fibers ensures the slowness of molecular diffusion processes.
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Yahiaoui, B., M. Loyens, A. Taibi, R. Schöneck, J. F. Dubremetz e M. A. Ouaissi. "Characterization of a Leishmania antigen associated with cytoplasmic vesicles resembling endosomal-like structure". Parasitology 107, n.º 5 (dezembro de 1993): 497–507. http://dx.doi.org/10.1017/s0031182000068074.
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SUMMARYIn the present study we have used antibodies to Leishmania major promastigote antigens which were eluted from a glutathione-agarose column (LmGbp) and could identify several parasite components among different Leishmania species by using immunoprecipitation and Western blot techniques. The results also showed that some of LmGbp are present among the molecules released into the culture medium. Moreover, immunofluorescence assays clearly demonstrated that LmGbp are expressed by intracellular amastigotes. The electron micrographs of thawed cryosections of L. major-infected cells revealed that the antigens were associated with the membrane of the phagocytic vacuole. Moreover, the Western blot technique allowed us to identify, using other Leishmania species extracts and anti-LmGbp antibodies, a major polypeptide of an apparent molecular mass of 66 kDa. Immunofluorescence studies suggested that the 66 kDa polypeptide is associated with intracytoplasmic vesicles. Cryosections of Leishmania promastigotes improved the fine structure preservation of the organelles and enabled a number of features to be seen, particularly the structures considered as vesicles, which appeared as a complex tubulo-vesicular structure resembling mammalian cell endosomes and Leishmania organelles previously named ‘megasomes’. Further studies using antibodies against the native 66 kDa protein will be needed to investigate the localization of the protein at the ultrastructural level and to follow its intracellular vesicular traffic.
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Bölke, Torsten, Lisa Krapf, Regina Orzekowsky-Schroeder, Tobias Vossmeyer, Jelena Dimitrijevic, Horst Weller, Anna Schüth, Antje Klinger, Gereon Hüttmann e Andreas Gebert. "Data-adaptive image-denoising for detecting and quantifying nanoparticle entry in mucosal tissues through intravital 2-photon microscopy". Beilstein Journal of Nanotechnology 5 (6 de novembro de 2014): 2016–25. http://dx.doi.org/10.3762/bjnano.5.210.
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Intravital 2-photon microscopy of mucosal membranes across which nanoparticles enter the organism typically generates noisy images. Because the noise results from the random statistics of only very few photons detected per pixel, it cannot be avoided by technical means. Fluorescent nanoparticles contained in the tissue may be represented by a few bright pixels which closely resemble the noise structure. We here present a data-adaptive method for digital denoising of datasets obtained by 2-photon microscopy. The algorithm exploits both local and non-local redundancy of the underlying ground-truth signal to reduce noise. Our approach automatically adapts the strength of noise suppression in a data-adaptive way by using a Bayesian network. The results show that the specific adaption to both signal and noise characteristics improves the preservation of fine structures such as nanoparticles while less artefacts were produced as compared to reference algorithms. Our method is applicable to other imaging modalities as well, provided the specific noise characteristics are known and taken into account.
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ILIEȘ, DORINA CAMELIA, LILIANA INDRIE, TUDOR CACIORA, GRIGORE VASILE HERMAN, ANCA HUNIADI, MIRCEA SANDOR, ADINA ALBU et al. "Heritage textiles – an integrated approach for assessment and future conservation". Industria Textila 73, n.º 02 (30 de abril de 2022): 159–64. http://dx.doi.org/10.35530/it.073.02.202040.
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The digital revolution has been present in our lives more and more since the beginning of the third millennium and until now, has affected the way in which cultural heritage is valued, preserved and passed on. In this context, the present study aims to use digital technologies (digital radiography and Reflectance Transformation Imaging) to contribute to assessing the conservation status of a heritage textile fabric; a traditional women’s shirt about 100 years old from Bihor County (ie). The investigations concerned both the fine details that are not visible to the naked eye, regarding the internal structure of the material and external (damaged areas, embroidery with traditional motifs, etc.). The results obtained show high suitability of the methods used for the analysis performed on historical textiles, having major importance in identifying the visual representation of the weave, the fibres and the surface of the fabric, the deterioration and also the current state of preservation and contributing to the identification of optimal restoration-conservation solutions.
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Sänger, Niklas, e Sebastian Abeck. "User Authorization in Microservice-Based Applications". Software 2, n.º 3 (19 de setembro de 2023): 400–426. http://dx.doi.org/10.3390/software2030019.
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Microservices have emerged as a prevalent architectural style in modern software development, replacing traditional monolithic architectures. The decomposition of business functionality into distributed microservices offers numerous benefits, but introduces increased complexity to the overall application. Consequently, the complexity of authorization in microservice-based applications necessitates a comprehensive approach that integrates authorization as an inherent component from the beginning. This paper presents a systematic approach for achieving fine-grained user authorization using Attribute-Based Access Control (ABAC). The proposed approach emphasizes structure preservation, facilitating traceability throughout the various phases of application development. As a result, authorization artifacts can be traced seamlessly from the initial analysis phase to the subsequent implementation phase. One significant contribution is the development of a language to formulate natural language authorization requirements and policies. These natural language authorization policies can subsequently be implemented using the policy language Rego. By leveraging the analysis of software artifacts, the proposed approach enables the creation of comprehensive and tailored authorization policies.
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Menezes, José C. J. M. D. S., e Vinícius R. Campos. "Bench to Any Side—The Pharmacology and Applications of Natural and Synthetic Alkylated Hydroxy Cinnamates and Cinnamides". Compounds 4, n.º 4 (4 de dezembro de 2024): 729–76. https://doi.org/10.3390/compounds4040044.
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Natural alkylated hydroxy cinnamates (AHCs) isolated from medicinal plants and the thereby designed and synthesized cinnamides are derivatives of hydroxy cinnamic acids such as p-coumaric, sinapic, ferulic, and caffeic acids, which are naturally derived from human dietary sources. The pharmacological properties displayed by AHCs based on their inherent structure range include antioxidant, antimicrobial, antiplasmodial, anti-tyrosinase, Alzheimer’s and Parkinson’s disease therapy, anticancer therapy, metabolic disease therapy, and biopesticides, which have not been reviewed together. Based on their inherent antioxidant, antimicrobial, and UV absorption and their structure–activity relationships, these cinnamyl esters and amides can be used for food preservation in emulsions and oils, as sun-protective components of skin care formulations, and in many other multifunctional applications. In conclusion, the fine-tuning of the structural features such as the type of hydroxy cinnamic acid used, the length of alkyl chains for variable lipophilicity, conversion from cinnamic to propanoic for antioxidants, the increase in methoxy or the change to amino groups to increase the molar absorption coefficient and loss of absorption values, the substitution by halides or amino groups for potent biopesticides, and conversion from esters to amide bonds leads to different AHCs for biomedical, cosmetic, and agriculture applications as an emerging field of investigation that can overall provide natural, safe, biodegradable, and sustainable molecules.
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Lee, Donggyu, Donghyun Kim e Chaedong Kang. "Effects of Nanostructure Additives on Supercooling and Freezing of Distilled Water". International Journal of Air-Conditioning and Refrigeration 28, n.º 04 (21 de outubro de 2020): 2050029. http://dx.doi.org/10.1142/s2010132520500297.
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The phenomenon of supercooling, which prevents freezing of water below the freezing point, is an obstacle to the production of inexpensive ice. In the case of ice heat storage systems using bio-preservation, low-temperature refrigeration of food and ice capsules in the HVAC industry, the supercooled water in capsules that indirectly come into contact with the outside is one of the problems that must be solved to maintain energy costs and the quality of food or organs. To improve this, experimental evaluation of additives that serve as crude nuclear agents is needed. However, research on this area needs to be supported because the types of additives are limited and their physical properties are unstable. In this paper, the effect of distilled water containing an additive of average diameter nanometer size on solution (frozen) supercooled below the freezing point was investigated. The supercooling time and supercooling level of each specimen were analyzed after addition of kaolin, strontium hydroxide, oxidizing mineral and nano-sized single-wall carbon nanotubes (SWCNT) as mineral fine particles in the distilled water. As a result, it has been confirmed that kaolin and SWCNT can be used as nuclear materials to release supercooling of water. In addition, when kaolin, a mineral fine particle, is used as a nuclear material, its size affects the performance of nuclearization. This confirmed the impact of nuclear material particle size and structure on overcooled emissions.
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Ajayakumar, Jayakrishnan, Andrew Curtis e Jacqueline Curtis. "The utility of Zip4 codes in spatial epidemiological analysis". PLOS ONE 18, n.º 5 (31 de maio de 2023): e0285552. http://dx.doi.org/10.1371/journal.pone.0285552.
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There are many public health situations within the United States that require fine geographical scale data to effectively inform response and intervention strategies. However, a condition for accessing and analyzing such data, especially when multiple institutions are involved, is being able to preserve a degree of spatial privacy and confidentiality. Hospitals and state health departments, who are generally the custodians of these fine-scale health data, are sometimes understandably hesitant to collaborate with each other due to these concerns. This paper looks at the utility and pitfalls of using Zip4 codes, a data layer often included as it is believed to be “safe”, as a source for sharing fine-scale spatial health data that enables privacy preservation while maintaining a suitable precision for spatial analysis. While the Zip4 is widely supplied, researchers seldom utilize it. Nor is its spatial characteristics known by data guardians. To address this gap, we use the context of a near-real time spatial response to an emerging health threat to show how the Zip4 aggregation preserves an underlying spatial structure making it potentially suitable dataset for analysis. Our results suggest that based on the density of urbanization, Zip4 centroids are within 150 meters of the real location almost 99% of the time. Spatial analysis experiments performed on these Zip4 data suggest a far more insightful geographic output than if using more commonly used aggregation units such as street lines and census block groups. However, this improvement in analytical output comes at a spatial privy cost as Zip4 centroids have a higher potential of compromising spatial anonymity with 73% of addresses having a spatial k anonymity value less than 5 when compared to other aggregations. We conclude that while offers an exciting opportunity to share data between organizations, researchers and analysts need to be made aware of the potential for serious confidentiality violations.
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Ben Chobba, Marwa, Maduka L. Weththimuni, Mouna Messaoud, Jamel Bouaziz, Rached Salhi, Filomena De Leo, Clara Urzì e Maurizio Licchelli. "Silver-Doped TiO2-PDMS Nanocomposite as a Possible Coating for the Preservation of Serena Stone: Searching for Optimal Application Conditions". Heritage 5, n.º 4 (11 de novembro de 2022): 3411–26. http://dx.doi.org/10.3390/heritage5040175.
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The main objective of this research is to determine the optimal application conditions of a newly synthesized multifunctional coating containing Ag-doped TiO2 nanoparticles when used as a possible protective agent for sandstone. Firstly, Ag-TiO2 nanoparticles with anatase structure, spherical shape and controllable sizes were prepared using the sol–gel method and characterized. The biocidal activity of Ag-doped TiO2 NPs was studied by comparing its performance to pure TiO2 NPs against two representative Gram-positive and Gram-negative bacterial strains, under both visible irradiation and in the dark; then, the antimicrobial efficiency of two different concentrations of Ag-TiO2 nanoparticles (0.1–1 mol%) was evaluated against two phototrophic strains commonly isolated from deteriorated surfaces. Results showed that the photoactivation and photokilling activity of TiO2 were highly improved by doping with Ag. Next, prepared nanopowders were dispersed in a binder with different powder/PDMS ratios: (0.1, 0.2, 0.5 and 1% w/v TiO2) and then applied in different amounts (2, 3 and 6 g/m2) on Serena stone specimens. Results revealed that the application of 2 g/m2 nanocomposite at powder/binder ratios equal to 1% w/v TiO2 provided a fine hydrophobic character for the stone material with acceptable chromatic variations.
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Mustoe, George E., e Elizabeth T. Smith. "Timing of Opalization at Lightning Ridge, Australia: New Evidence from Opalized Fossils". Minerals 13, n.º 12 (23 de novembro de 2023): 1471. http://dx.doi.org/10.3390/min13121471.
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Microscopic analysis of fossils from the Lightning Ridge district of northwestern New South Wales, Australia, shows that opal has been typically deposited in variable cavities left by the degradation of the original organic material. Fine-grained, clay-rich sediments have preserved the external morphology, and opalization has produced detailed casts with different modes of preservation of internal details. Plant remains include cones, cone scales, fruiting bodies, and seeds, but the most common specimens are twigs, stems, and wood fragments. These specimens commonly contain angular inclusions that represent small tissue fragments produced by the degradation of the original wood. Inclusions commonly have a “hollow box” structure where the organic material has decomposed after the initial opal filling of the mold. These spaces commonly contain traces of the cellular architecture, in the form of wood fiber textures imprinted on the cavity wall, degraded cellular material, and silicified tracheids. Opal casts of mollusk shells and crustacean bioliths preserve the shape but no calcium carbonate residue. Likewise, opal casts of vertebrate remains (bones, teeth, osteoderms) lack preservation of the original bioapatite. These compositions are evidence that burial in fine clays and silts, isolated from the effects of water and oxygen, caused protracted delays between the timing of burial, decomposition, and the development of vacuities in the claystones that became sites for opal precipitation. The length of time required for the dissolution of cellulosic/ligninitic plant remains, calcium carbonate items, and calcium phosphates in bones and teeth cannot be quantified, but evidence from opal-bearing formations worldwide reveals that these processes can be very slow. The timing of opalization can be inferred from previous studies that concluded that Cenozoic tectonism produced faults and fissures that allowed horizontal and lateral movement of silica-bearing groundwater. Comparisons of Australian opal-AG with opal from international localities suggest that opalization was a Neogene phenomenon. The transformation of Opal-AG → Opal-CT is well-documented for the diagenesis of siliceous biogenic sediments and siliceous sinter from geothermal areas. Likewise, precious and common opal from the late Miocene Virgin Valley Formation in northern Nevada, USA, shows the rapidity of the Opal-AG → Opal-CT transformation. Taken together, we consider this evidence to indicate a Neogene age for Lightning Ridge opalization and by inference for the opalization of the extensive opal deposits of the Great Artesian Basin in Australia. New paleontology discoveries include a surprising level of cellular detail in plant fossils, the preservation of individual tracheids as opal casts, evidence of opalized plant pith or vascular tissue (non-gymnosperm), and the first report of Early Cretaceous coprolites from New South Wales, Australia.
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Yang, Guangcan, Jiayang Li, Yunhua He, Ke Xiao, Yang Xin, Hongliang Zhu e Chen Li. "A Security-Enhanced Query Result Verification Scheme for Outsourced Data in Location-Based Services". Applied Sciences 12, n.º 16 (13 de agosto de 2022): 8126. http://dx.doi.org/10.3390/app12168126.
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Location-based services (LBSs) facilitate people’s lives; location-based service providers (LBSPs) usually outsource services to third parties to provide better services. However, the third party is a dishonest entity that might return incorrect or incomplete query results under the consideration of saving storage space and computation resources. In this paper, we propose a security-enhanced query result verification scheme (SEQRVS) for the outsourced data in a LBS. Specifically, while retaining fine-grained query result verification, we improve the construction process of verification objects to enhance the security of the outsourced data. To prevent the third party from deducing the knowledge of the outsourced data stored in itself (statistically), our scheme designs a novel storage structure to enhance the ability of privacy preservation for the outsourced data. Furthermore, based on the secure keyword search and query result verification mode proposed in our scheme, the user cannot only verify the correctness and completeness of the query result but also achieve consistency verification by the blockchain. Finally, the security analysis and extensive simulation results show the security and practicality of the proposed scheme.