80 research outputs found

    Correction to Lagrangian for Bouncing Cosmologies in f(Q)f(Q) Gravity

    Full text link
    Symmetric teleparallel gravity offers to reformulate the gravitational formalism without the presence of curvature and torsion with the help of non-metricity tensors. Interestingly, Symmetric teleparallel gravity can be formulated equivalently to teleparallel gravity or general relativity for an appropriate setup. In this study, our aim lies in exploring the bouncing cosmologies as an alternative to the initial singularity of the Universe in the background of modified symmetric teleparallel gravity. To explore this, we adopt the reconstruction technique to present the possible reconstructed Lagrangian for various cosmological bouncing solutions in a flat Friedmann-Lema\^itre-Robertson-Walker spacetime with a perfect fluid matter distribution. We study the reconstructed gravitational Lagrangians, which are capable of reproducing analytical solutions for \textit{symmetric bounce}, \textit{super-bounce}, \textit{oscillatory bounce}, \textit{matter bounce}, and \textit{exponential bouncing} model settings. Further, we examine the dark energy profiles of the models using reconstructed Lagrangians. In addition, we found that an additional term arises in each reconstructed Lagrangian compared to general relativity (GR). That extra term corrected the background GR to present bouncing cosmology in modified gravity. These newly motivated cosmological models may have an effect on gravitational phenomena at other cosmological scales.Comment: Comments are welcom

    Cytoskeletal control of B cell responses to antigens.

    Get PDF
    The actin cytoskeleton is essential for cell mechanics and has increasingly been implicated in the regulation of cell signalling. In B cells, the actin cytoskeleton is extensively coupled to B cell receptor (BCR) signalling pathways, and defects of the actin cytoskeleton can either promote or suppress B cell activation. Recent insights from studies using single-cell imaging and biophysical techniques suggest that actin orchestrates BCR signalling at the plasma membrane through effects on protein diffusion and that it regulates antigen discrimination through the biomechanics of immune synapses. These mechanical functions also have a role in the adaptation of B cell subsets to specialized tasks during antibody responses

    International Journal of Pharma and Bio Sciences RESEARCH ARTICLE MEDICINAL CHEMISTRY SYNTHESIS, CHARACTERIZATIONAND BIOLOGICAL STUDIES OF 2-[(2-

    No full text
    A new Schiff base derived from 2-amino, 4-methyl phenol with 5-nitro salicylaldehyde (AMPNSA) and their Ti(IV) and Zr(IV) metal complexes. The metal chelates were characterized on the basis of infrared spectra, elemental analysis, electronic spectral data, conductance and 1 H NMR spectral analysis. The complexes confirm to 1:1 stoichiometry and are electrolyte in nature. The coordination of the ligand to the metal ions is found to be through azomethine nitrogen, phenoxide oxygen and phenolic – OH of the Schiff base in the octahedral environment. The Schiff base and its metal complexes have been tested for their antimicrobial activity using disc diffusion methods and the results discussed. This article can be downloaded from www.ijpbs.ne

    Complexes of Bacterial Nicotinate Mononucleotide Adenylyltransferase with Inhibitors: Implication for Structure-Based Drug Design and Improvement

    No full text
    Bacterial nicotinate mononucleotide adenylyltransferase encoded by the essential gene nadD plays a central role in the synthesis of the redox cofactor NAD(+). The NadD enzyme is conserved in the majority of bacterial species and has been recognized as a novel target for developing new and potentially broad-spectrum antibacterial therapeutics. Here we report the crystal structures of Bacillus anthracis NadD in complex with three NadD inhibitors, including two analogues synthesized in the present study. These structures revealed a common binding site shared by different classes of NadD inhibitors and explored the chemical environment surrounding this site. The structural data obtained here also showed that the subtle changes in ligand structure can lead to significant changes in the binding mode, information that will be useful for future structure-based optimization and design of high affinity inhibitors
    • …
    corecore