Magnetite/CdTe magnetic-fluorescent composite nanosystem for magnetic separation and bio-imaging

A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.     

Recent Developments in β-Cell Differentiation of Pluripotent Stem Cells Induced by Small and Large Molecules

Human pluripotent stem cells, including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), hold promise as novel therapeutic tools for diabetes treatment because of their self-renewal capacity and ability to differentiate into beta (β)-cells. Small and large molecules play important roles in each stage of β-cell differentiation from both hESCs and hiPSCs. The small and large molecules that are described in this review have significantly advanced efforts to cure diabetic disease. Lately, effective protocols have been implemented to induce hESCs and human mesenchymal stem cells (hMSCs) to differentiate into functional β-cells. Several small molecules, proteins, and growth factors promote pancreatic differentiation from hESCs and hMSCs. These small molecules (e.g., cyclopamine, wortmannin, retinoic acid, and sodium butyrate) and large molecules (e.g. activin A, betacellulin, bone morphogentic protein (BMP4), epidermal growth factor (EGF), fibroblast growth factor (FGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), noggin, transforming growth factor (TGF-α), and WNT3A) are thought to contribute from the initial stages of definitive endoderm formation to the final stages of maturation of functional endocrine cells. We discuss the importance of such small and large molecules in uniquely optimized protocols of β-cell differentiation from stem cells. A global understanding of various small and large molecules and their functions will help to establish an efficient protocol for β-cell differentiation.     

Fractionation of stable isotope-labeled organic pollutants as a potential tracer of atmospheric transport processes

To test the potential for using stable isotope fractionation to examine the atmospheric transport of semivolatile organic compounds (SOCs), we conducted simplified distillation experiments in the laboratory and a tracer-release experiment using mixtures of stable isotope-labeled (D and 13C) and unlabeled SOCs. Perdeuterated phenanthrene and alpha-hexachlorocyclohexane were transported more slowly via air-water gas exchange in our laboratory experiments, resulting in significant isotope fractionation of perdeuterated/unlabeled compound mixtures. In contrast, isotope fractionation of 13C6-labeled SOCs was much lower. A field tracer-release study was then conducted by spiking a seawater retention pond with a mixture of D10-labeled, 13C2-labeled, and unlabeled phenanthrene and examining isotope fractionation of the mixture after air-water gas exchange. No preferential fractionation of D10-vs 13C2-labeled phenanthrene was observed in the pond water; however, greater fractionation of D10-vs 13C2-labeled phenanthrene was observed in air samples collected within a 1-100 m radius of the pond. Thus, stable isotope tracers may provide a means of examining the atmospheric transport and air-earth exchange rates of POPs in an environmental realistic setting.     

Agricultural leaf blight disease segmentation using indices based histogram intensity segmentation approach

Multimedia Tools and Applications - Grouping of pixels based on certain kind of similarity or discontinuity among the pixel called Segmentation. Segmentation of ROI from the given input image...