Using positional information to provide context for biological image analysis with MorphoGraphX 2.0.

Positional information is a central concept in developmental biology. In developing organs, positional information can be idealized as a local coordinate system that arises from morphogen gradients controlled by organizers at key locations. This offers a plausible mechanism for the integration of the molecular networks operating in individual cells into the spatially coordinated multicellular responses necessary for the organization of emergent forms. Understanding how positional cues guide morphogenesis requires the quantification of gene expression and growth dynamics in the context of their underlying coordinate systems. Here, we present recent advances in the MorphoGraphX software (Barbier de Reuille et al., 2015⁠) that implement a generalized framework to annotate developing organs with local coordinate systems. These coordinate systems introduce an organ-centric spatial context to microscopy data, allowing gene expression and growth to be quantified and compared in the context of the positional information thought to control them.

A 1-year comparative evaluation of clinical performance of nanohybrid composite with Activa™ bioactive composite in Class II carious lesion: A randomized control study.

AIM: The aim of this study was to compare and evaluate the clinical performance of nanohybrid composite with Activa™ bioactive composites in Class II carious lesion. METHODOLOGY: After ethical approval, patients were selected according to the inclusion-exclusion criteria with minimum of two carious lesions in a single patient. Lesions were randomly divided into two groups: Group A - nanohybrid composite and Group B - Activa™ bioactive composite. After administration of local anesthetic agent, Class II cavity preparation was done followed by rubber dam application. For deep lesion, pulp protection was done with light-cured calcium hydroxide. Then, the cavities were restored. Finishing and polishing were done. Evaluation of the restorations was done at 1 week, 6 months, and 1 year time interval by second-blinded examiner according to the modified USPHS criteria. The results of the study were tabulated, and statistical analysis was done. RESULTS: The results showed no statistically significant difference in the clinical performance of nanohybrid composite and Activa™ bioactive composites in Class II carious lesions at the end of 1 week, 6 months, and 1 year. CONCLUSION: It can be concluded that both materials showed equal and acceptable clinical performance at the end of 1 year. Both materials can be successfully be used to restore Class II carious lesions.

MorphoGraphX: A platform for quantifying morphogenesis in 4D.

Morphogenesis emerges from complex multiscale interactions between genetic and mechanical processes. To understand these processes, the evolution of cell shape, proliferation and gene expression must be quantified. This quantification is usually performed either in full 3D, which is computationally expensive and technically challenging, or on 2D planar projections, which introduces geometrical artifacts on highly curved organs. Here we present MorphoGraphX ( www.MorphoGraphX.org), a software that bridges this gap by working directly with curved surface images extracted from 3D data. In addition to traditional 3D image analysis, we have developed algorithms to operate on curved surfaces, such as cell segmentation, lineage tracking and fluorescence signal quantification. The software's modular design makes it easy to include existing libraries, or to implement new algorithms. Cell geometries extracted with MorphoGraphX can be exported and used as templates for simulation models, providing a powerful platform to investigate the interactions between shape, genes and growth.

Effects of rare earth ions (Tb, Ce, Eu, Dy) on the thermoluminescence characteristics of sol-gel derived and γ-irradiated SiO2 nanoparticles.

Highly pure SiO2 and SiO2 :RE nanoparticles were synthesized by the sol-gel method. The morphological, structural and optical properties of the nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results indicate that all the samples studied were free from impurities. SEM/TEM results indicate that the samples were well dispersed. Surface characterization of the nanocrystals by Fourier transform infrared spectroscopy has been carried out and the structure of surface-bound SiO2 based on spectral analysis is proposed. Thermoluminescence (TL) characteristics were investigated to study the influence of rare earth dopants (Tb, Ce, Eu, Dy) on SiO2 matrix subjected to 0.5 kG (1 h) γ-irradiation. Among these rare earth elements, Eu(3+) was found to be the most efficient dopant for SiO2 showing maximum thermoluminescence intensity. SiO2 :Eu0.5 seems to be a promising candidate for use as a TL dosimeter.