All Publications

  • Super-resolved 3-D imaging of live cells' organelles from bright-field photon transmission micrographs. Ultramicroscopy Rychtáriková, R., Náhlík, T., Shi, K., Malakhova, D., Machácek, P., Smaha, R., Urban, J., Štys, D. 2017; 179: 1-14


    Current biological and medical research is aimed at obtaining a detailed spatiotemporal map of a live cell's interior to describe and predict cell's physiological state. We present here an algorithm for complete 3-D modelling of cellular structures from a z-stack of images obtained using label-free wide-field bright-field light-transmitted microscopy. The method visualizes 3-D objects with a volume equivalent to the area of a camera pixel multiplied by the z-height. The computation is based on finding pixels of unchanged intensities between two consecutive images of an object spread function. These pixels represent strongly light-diffracting, light-absorbing, or light-emitting objects. To accomplish this, variables derived from Rényi entropy are used to suppress camera noise. Using this algorithm, the detection limit of objects is only limited by the technical specifications of the microscope setup-we achieve the detection of objects of the size of one camera pixel. This method allows us to obtain 3-D reconstructions of cells from bright-field microscopy images that are comparable in quality to those from electron microscopy images.

    View details for DOI 10.1016/j.ultramic.2017.03.018

    View details for PubMedID 28364682

  • Chemical Approaches to Addressing the Instability and Toxicity of Lead-Halide Perovskite Absorbers INORGANIC CHEMISTRY Slayney, A. H., Smaha, R. W., Smith, I. C., Jaffe, A., Umeyama, D., Karunadasa, H. I. 2017; 56 (1): 46-55


    The impressive rise in efficiencies of solar cells employing the three-dimensional (3D) lead-iodide perovskite absorbers APbI3 (A = monovalent cation) has generated intense excitement. Although these perovskites have remarkable properties as solar-cell absorbers, their potential commercialization now requires a greater focus on the materials' inherent shortcomings and environmental impact. This creates a challenge and an opportunity for synthetic chemists to address these issues through the design of new materials. Synthetic chemistry offers powerful tools for manipulating the magnificent flexibility of the perovskite lattice to expand the number of functional analogues to APbI3. To highlight improvements that should be targeted in new materials, here we discuss the intrinsic instability and toxicity of 3D lead-halide perovskites. We consider possible sources of these instabilities and propose methods to overcome them through synthetic design. We also discuss new materials developed for realizing the exceptional photophysical properties of lead-halide perovskites in more environmentally benign materials. In this Forum Article, we provide a brief overview of the field with a focus on our group's contributions to identifying and addressing problems inherent to 3D lead-halide perovskites.

    View details for DOI 10.1021/acs.inorgchem.6b01336

    View details for Web of Science ID 000391248900007

    View details for PubMedID 27494338

  • Tuning Sodium Ion Conductivity in the Layered Honeycomb Oxide Na3-xSn2-xSbx,NaO6 INORGANIC CHEMISTRY Smaha, R. W., Roudebush, J. H., Herb, J. T., Seibel, E. M., Krizan, J. W., Fox, G. M., Huang, Q., Arnold, C. B., Cava, R. J. 2015; 54 (16): 7985-7991
  • How Natural Are Artificial Languages? Language Production, Cognition, and the Lexicon Smaha, R., Fellbaum, C. Springer. 2015: 299–312
  • Multifractality in Imaging: Application of Information Entropy for Observation of Inner Dynamics Inside of an Unlabeled Living Cell in Bright-Field Microscopy ISCS 2014: Interdisciplinary Symposium on Complex Systems Rychtarikova, R., Nahlik, T., Smaha, R., Urban, J., Stys Jr, D., Cisar, P., Stys, D. Springer. 2015