"Sporotan" a new fluorescent stain for identifying cryptic spores of Rhodobacter johrii.

We propose a new fluorescent stain "sporotan" and staining protocol which aid in the identification of cryptic endospores which are otherwise mistaken as poly-ß-hydroxyalkanoate granules.

Zwitterionic small molecule based fluorophores for efficient and selective imaging of bacterial endospores.

In the emerging scenario of increasing antibiotic resistance and pathogen transmission channels, the grave danger posed by bacterial endospores in critical fields like food industry, health and medicine highlights the urgent need to develop efficient probes for their detection; their sturdy and impermeable multilayer coat makes desirable methods like fluorescence imaging extremely difficult. Selective imaging of the endospores in the presence of the bacteria is even more challenging. Furthermore, it is preferable to maintain the dormant state of endospores through the imaging process, if extended monitoring is required; many of the available techniques involve lethal germination or destruction of the endospores. We show that simple zwitterionic diaminodicyanoquinodimethane (DADQ) molecules with selected functionalities are efficient dyes for fluorescence imaging due to their dipolar structure that facilitates the penetration into the endospore system, and the enhanced fluorescence in their rigid/aggregated state. The facile structural tailorability allows DADQs with various appendage moieties to be synthesized; a derivative with ionic substituents (BT2), and another with optimally long alkyl chains and the resultant hydrophobic character (BHADQ) are shown to be excellent fluorescent probes for endospores. Nanomolar amounts of dyes provide effective staining; while BT2 stains bacteria and endospores, most significantly, BHADQ stains endospores selectively. To the best of our knowledge, this is the first example of selective fluorescence imaging of endospores in their dormant state. A range of spectroscopy, microscopy and calorimetry studies provide insight into the molecular level interactions that enable efficient staining and bright images. DADQ fluorophores are photostable and non-cytotoxic, hence useful in practical applications. The versatile structural tailorability of these dye molecules holds great promise for targeted imaging.

Efficient Bioimaging with Diaminodicyanoquinodimethanes: Selective Imaging of Epidermal and Stomatal Cells and Insight into the Molecular Level Interactions.

The enhanced fluorescence emission of diaminodicyanoquinodimethanes (DADQs) in rigid and aggregated states holds great promise for bioimaging applications. This is demonstrated through their efficient application in epidermal and stomatal imaging with selective staining of cell walls and nuclei. Major advantages include the small quantities (a few nmols) of the fluorophore required, choice of DADQs soluble in water and organic solvents, and quick staining of the specimen in buffer-free state and in buffer medium. The molecular level interactions that enable staining are unraveled through isothermal calorimetry, infra-red spectroscopy and microscopy with energy dispersive X-ray spectroscopy analysis. It is proposed that DADQs with ionic or H-bonding functionalities bind to the polygalacturonic acid moieties in the epidermal layer; the former can bind also to nucleic acid polyanions. Fluorescence experiments explain the emission enhancement that enables the efficient imaging. DADQs are easy to synthesize, non-cytotoxic, and thermally, chemically and photo-stable, requiring no special storage conditions; preliminary experiments point to their potential utility in imaging different classes of cells.

An enhanced bacterial foraging algorithm approach for optimal power flow problem including FACTS devices considering system loadability.

Obtaining optimal power flow solution is a strenuous task for any power system engineer. The inclusion of FACTS devices in the power system network adds to its complexity. The dual objective of OPF with fuel cost minimization along with FACTS device location for IEEE 30 bus is considered and solved using proposed Enhanced Bacterial Foraging algorithm (EBFA). The conventional Bacterial Foraging Algorithm (BFA) has the difficulty of optimal parameter selection. Hence, in this paper, BFA is enhanced by including Nelder-Mead (NM) algorithm for better performance. A MATLAB code for EBFA is developed and the problem of optimal power flow with inclusion of FACTS devices is solved. After several run with different initial values, it is found that the inclusion of FACTS devices such as SVC and TCSC in the network reduces the generation cost along with increased voltage stability limits. It is also observed that, the proposed algorithm requires lesser computational time compared to earlier proposed algorithms.