A computationalimage analysing algorithm was developed for the separation and quantitative characterisation of different Mg17Al12 phases in the long term annealed (LTA), high pressure die cast (hpdc) AZ91 magnesium a...
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A computationalimage analysing algorithm was developed for the separation and quantitative characterisation of different Mg17Al12 phases in the long term annealed (LTA), high pressure die cast (hpdc) AZ91 magnesium alloy such as beta(m) (massive) and beta(c+d) (continuous + discontinuous). The size distribution, nearest neighbour distance (NND) distribution, number density, average size, average NND and area fraction of beta(m) and beta(c+d) phases with respect to different annealing temperatures were obtained by means of novel imageprocessing techniques and compared with the as-cast (AC) material. The different trends associated with the changes of these quantities and morphologies, nucleation and agglomeration of the phases with respect to the annealing temperature is explained. These micro quantities are also correlated with the tensile properties of different annealed castings. (C) 2008 Elsevier B.V. All rights reserved.
Fluorescence in situ hybridization (FISH) is based on the use of fluorescent staining dyes, however, the signal intensity of the images obtained by microscopy is seldom quantified with accuracy by the researcher. The ...
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Fluorescence in situ hybridization (FISH) is based on the use of fluorescent staining dyes, however, the signal intensity of the images obtained by microscopy is seldom quantified with accuracy by the researcher. The development of innovative digital imageprocessing programs and tools has been trying to overcome this problem, however, the determination of fluorescent intensity in microscopy images still has issues due to the lack of precision in the results and the complexity of existing software. This work presents FISHji, a set of new imageJ methods for automated quantification of fluorescence in images obtained by epifluorescence microscopy. To validate the methods, results obtained by FISHji were compared with results obtained by flow cytometry. The mean correlation between FISHji and flow cytometry was high and significant, showing that the imaging methods are able to accurately assess the signal intensity of fluorescence images. FISHji are available for non-commercial use at http://***/similar to nazevedo/. (c) 2016 Elsevier B.V. All rights reserved.
Interfacial pH changes and bubble dynamics play pivotal roles in water electrolysis, significantly impacting cell overvoltage and energy consumption. The quantification of these changes has proven challenging, given t...
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Interfacial pH changes and bubble dynamics play pivotal roles in water electrolysis, significantly impacting cell overvoltage and energy consumption. The quantification of these changes has proven challenging, given the traditional focus on bulk solution pH fluctuations. In contrast to previous studies on individual bubble growth, this research adopts a distinctive approach, analyzing over than 8,000 bubbles in each experiment through advanced imageprocessingcomputational procedures for edge detection. This methodology provides extensive data for comprehensive statistical analysis. Furthermore, the study delves into the generation of H2 2 and O2 2 bubbles during water electrolysis in both acidic and alkaline media, employing a platinum strip electrode. Crucial experimental variables, such as electrolyte pH, gas type, and current density, are systematically explored for their influence on bubble size and distribution using a 23 3 factorial design. In addition to this work, finite element simulations were conducted to model interfacial pH under the same experimental conditions. These simulations substantiate our experimental findings, confirming the occurrence of interfacial pH transitions in some instances. This transition, in turn, influences the bubble size distribution and consequently impacts cell voltage. These experimental and simulated datasets and potential curves allow for comparing interfacial pH changes with bubble size and the cell voltage relationship. With broad implications for various applications, such as energy production and material development, where interfacial pH changes and bubble formation are essential, this novel approach allows the optimization of boundary conditions for more effective electrochemical processes.
Objective: Changes in microvascular perfusion have been reported in many diseases, yet the functional significance of altered perfusion is often difficult to determine. This is partly because commonly used techniques ...
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Objective: Changes in microvascular perfusion have been reported in many diseases, yet the functional significance of altered perfusion is often difficult to determine. This is partly because commonly used techniques for perfusion measurement often rely on either indirect or by-hand approaches. Methods: We developed and validated a fully automated software technique to measure microvascular perfusion in videos acquired by fluorescence microscopy in the mouse gastrocnemius. Acute perfusion responses were recorded following intravenous injections with phenylephrine, SNP, or saline. Results: Software-measured capillary flow velocity closely correlated with by-hand measured flow velocity (R-2 = 0.91, P < 0.0001). Software estimates of capillary hematocrit also generally agreed with by-hand measurements (R-2 = 0.64, P < 0.0001). Detection limits range from 0 to 2000 mu m/s, as compared to an average flow velocity of 326 +/- 102 mu m/s (mean +/- SD) at rest. SNP injection transiently increased capillary flow velocity and hematocrit and made capillary perfusion more steady and homogenous. Phenylephrine injection had the opposite effect in all metrics. Saline injection transiently decreased capillary flow velocity and hematocrit without influencing flow distribution or stability. All perfusion metrics were temporally stable without intervention. Conclusions: These results demonstrate a novel and sensitive technique for reproducible, user-independent quantification of microvascular perfusion.
Using a computer‐controlled fluorescence microscope system, spatial arrangement of homologous chromosomes was analyzed in fixed and living embryos of Drosophila melanogaster at the syncytial blastoderm stage. In fixe...
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Using a computer‐controlled fluorescence microscope system, spatial arrangement of homologous chromosomes was analyzed in fixed and living embryos of Drosophila melanogaster at the syncytial blastoderm stage. In fixed embryos, chromosomes were stained with a DNA‐specific fluorescent dye, 4′,6‐diamidino‐2‐phenylindole; the arrangement of anaphase chromosomes was determined with their identification by high‐resolution analysis. In living embryos, the behavior of chromosomes during anaphase was examined by the use of a strain carrying a long translocated chromosome as a cytological marker to identify the chromosome while the chromosomes were stained by microinjection of rhodamine‐conjugated histones into the embryos. Chromosome arrangement was also examined in nuclei that had swollen artificially under anoxic conditions for better spatial separation of individual chromosomes in such nuclei. All these experiments consistently showed that homologous chromosomes were not associated with each other in syncytial blastoderm embryos of Drosophila melanogaster. Our studies also demonstrated that cytological tools greatly facilitate the dissection of nuclear structures when used in combination with imaging technology.
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