Different approaches to Imaging Mass Cytometry data analysis

Imaging Mass Cytometry (IMC) is a novel, high multiplexing imaging platform capable of simultaneously detecting and visualizing up to 40 different protein targets. It is a strong asset available for in-depth study of histology and pathophysiology of the tissues. Bearing in mind the robustness of this technique and the high spatial context of the data it gives, it is especially valuable in studying the biology of cancer and tumor microenvironment. IMC-derived data are not classical micrographic images, and due to the characteristics of the data obtained using IMC, the image analysis approach, in this case, can diverge to a certain degree from the classical image analysis pipelines. As the number of publications based on the IMC is on the rise, this trend is also followed by an increase in the number of available methodologies designated solely to IMC-derived data analysis. This review has for an aim to give a systematic synopsis of all the available classical image analysis tools and pipelines useful to be employed for IMC data analysis and give an overview of tools intentionally developed solely for this purpose, easing the choice to researchers of selecting the most suitable methodologies for a specific type of analysis desired.publishedVersio

High concentration of hematite nanoparticles in a silica matrix: Structural and magnetic properties

The alpha-Fe(2)O(3)/SiO(2) nanocomposite containing 45 wt% of hematite was prepared by the sol-gel method followed by heating in air at 200 degrees C. The so-obtained composite of iron(III) nanoparticles dissolved in glassy silica matrix was investigated by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID) magnetometry. XRPD confirms the formation of a single-phase hematite sample, whereas TEM reveals spherical particles in a silica matrix with an average diameter of 10 nm. DC magnetization shows bifurcation of the zero-field-cooled (ZFC) and field-cooled (FC) branches up to the room temperature with a blocking temperature TB 65 K. Isothermal M( H) dependence displays significant hysteretic behaviour below TB, whereas the room temperature data were successfully fitted to a weighted Langevin function. The average particle size obtained from this fit is in agreement with the TEM findings. The small shift of the TB value with the magnetic field strength, narrowing of the hysteresis loop at low applied field, and the frequency dependence of the AC susceptibility data point to the presence of inter-particle interactions. The analysis of the results suggests that the system consists of single-domain nanoparticles with intermediate strength interactions. (c) 2008 Elsevier B.V. All rights reserved

Anomalous behaviour of the magnetic hysteresis loop in the alpha-Fe2O3/SiO2 nanocomposite

The alpha-Fe2O3/SiO2 nanocomposite containing 45 wt.% of hematite was prepared by the sol-gel method and characterized by using X-ray diffractometer (XRD), transmission electron microscopy (TEM) and. superconducting quantum interference device (SQUID) magnetometer. TEM microscopy showed spherical particles with average size about 10 nm, whereas XRD diffraction confirmed the formation of the hematite phase. The magnetic measurements showed anomalous behavior of the hysteresis loops including decrease of high field isothermal magnetization and overlap of initial, remagnetization and magnetization curves. This anomalous behavior represents a novel effect for alpha-Fe2O3/SiO2 nanocomposites. We conjecture that a field-induced antiferromagnetic coupling between nanoparticles may produce this effect. (C) 2009 Elsevier B.V. All rights reserved

Removal of copper from aqueous solutions by low cost adsorbent-Kolubara lignite

Serbian lignite from Kolubara deposit was used as a low cost adsorbent for removal of copper ions (Cu2+) from aqueous solutions. Lignite was subjected to the elementary and technical analysis as well as BET and FTIR analysis due to complete characterization. Basic comparison between lignite and activated carbon was also done. As a method, batch adsorption procedure was applied. Adsorption efficiency was studied as a function of the initial metal concentration, pH of the solution, contact time, and amount of the adsorbent. Optimum removal of copper ions was achieved at pH values of 5.0. About 90% of copper cations were removed in 5 min of contact time from the solution with the lowest copper concentration (50 mg Cu2+/l) regardless adsorbent amount, while the same effect of adsorption was achieved in 60 min in case of solutions with higher concentrations of copper. It was concluded that the effect of adsorbent amount on adsorption kinetics is evident but not crucial. It was proved that the experimental results of copper adsorption fit well to a Langmuirian type isotherm which was used to describe monitored adsorption phenomena. The calculated adsorption capacities of lignite for copper adsorption decrease with increasing adsorbent amount. The study proved that tested lignite is very efficient adsorbent material, especially in case of low copper concentration in aqueous solution where the usual methods are either economically unrewarding or technically complicated. This behavior can be explained by FTIR spectrum despite a small specific surface area of lignite. Namely, many bands (peaks) are attributed to the functional groups that they are involved in chemisorption and ionic exchange, basic mechanisms of copper adsorption. (C) 2011 Elsevier B.V. All rights reserved

Surfactant modification and adsorption properties of clinoptilolite for the removal of pertechnetate from aqueous solutions

Natural clinoptilolite modified with a cationic surfactant stearyldimethylbenzylammonium chloride (SDBAC) was used as an adsorbent for the removal of pertechnetate from aqueous solutions. Adsorption studies were performed in a batch system. The effects of various experimental parameters (amount of surfactant loading, contact time, solution pH, competing anions) on the removal efficiency of TcO4 (-) were investigated. SDBAC-clinoptilolite with organo-bilayer was successfully used to remove TcO4 (-) from aqueous solutions in the pH range of 5.0-8.0. ReO4 (-) as an analogue of TcO4 (-) was used to model the isotherms. Adsorption capacity of the SDBAC-clinoptilolite and the mechanism of ReO4 (-) (TcO4 (-)) sorption were also determined

Removal of Heavy Metals from Aqueous Solution Using Natural and Fe(Iii) Oxyhydroxide Clinoptilolite

The increasing levels of industrial wastewater released to the environment present a serious threat to human health, living resources, and ecological systems. Fe-modified zeolites were developed and tested for removal of Cu2+ and Zn2+ from contaminated water. The surfaces of the naturally occurring zeolite, clinoptilolite, were modified with Fe(III) oxyhydroxides using three different methods, denoted I, II, and III (FeCli(1), FeCli(2), and FeNaCli(1), respectively). The oxyhydroxides were prepared in Method I using 0.1 M FeCl3 center dot 6H(2)O in an acetate buffer (pH = 3.6); in Method II, using 10% FeCl3 center dot 6H(2)O solution in 0.1 M KOH (pH = 10); and Method III was the same as Method I except the clinoptilolite was pretreated with NaCl. Newly synthesized materials from these three methods were then tested for their ability to enhance the sorption capacity for Cu and Zn compared to the natural sample (Cli). Powder X-ray diffraction measurements and the chemical composition of these modified samples confirmed that clinoptilolite maintained its structure while amorphous Fe3+ species were synthesized. The specific surface area (BET method) of both the natural and modified clinoptilolite increased by 2 and 7.5 times for Methods I and II, respectively. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed that CaO was formed during Method I (FeCli(1)). Throughout the adsorption process, the hydrolysis of CaO and the release of OH- caused the precipitation of Cu and Zn hydroxide, which made the determination of the sorption capacity of FeCli(1) impossible. This phenomenon was avoided in Method III (FeNaCli(1)) because of the absence of exchangeable Ca2+. The adsorption experiments with Method II resulted in double-enchanced adsoprtion capacity. Laboratory batch experiments revealed that the sorption capacities increased in the following order: Cli LT FeCli(2) LT FeNaCli(1), for Cu: 0.121 mmol/g LT 0.251 mmol/g LT 0.403 mmol/g and for Zn: 0.128 mmol/g LT 0.234 mmol/g LT 0.381 mmol/g