National University of Uzbekistan (NUUz) (Uzbek: Mirzo Ulugbek nomidagi O'zbekiston Milliy Universiteti, O'zMU) is a public university located in Tashkent, Uzbekistan. NUUz is the oldest and largest university in Uzbekistan.[citation needed]National University of Uzbekistan is named after Mirzo Ulugbek.[clarification needed] NUUz professors and teaching staff work with modern materials and science and have relationships with the world's distinguished scientific schools.
We study axial gravitational perturbations of the neutral regular black hole generated by a non-local, T-duality-inspired zero-point length and the associated gravitational self-energy. In this geometry, the usual point source is replaced by a regular core, and the zero-point length controls the departure from the Schwarzschild limit. We compute the fundamental quasinormal modes and several overtones with high-order WKB–Padé methods, and we check the dominant mode with a direct time-domain evolution. When the zero-point length is turned on, the real parts of the ADM-scaled frequencies increase for the gravitational modes with ℓ=2,3,4, so the ringdown oscillates faster than in the Schwarzschild limit. The damping rates change more mildly: they first grow slightly and then decrease near the largest deformation values considered here. This behavior is consistent with the effective potential, whose barrier becomes higher as the deformation parameter increases. We also compute the corresponding excitation factors and find that their magnitudes vary much less strongly than the quasinormal frequencies.
The persistent global burden of tuberculosis (TB) and the context-dependent efficacy of the Bacillus Calmette–Guérin (BCG) vaccine necessitate the development of innovative prophylactic strategies. mRNA vaccine platforms have emerged as a transformative toolkit, offering unprecedented versatility in antigen design and manufacturing scalability. This inclusive innovation review synthesizes the molecular engineering and immunological mechanisms of mRNA TB vaccines, evaluating their capacity to address the unique challenges posed by the intracellular lifestyle of Mycobacterium tuberculosis (Mtb). mRNA platforms realistically offer superior endogenous antigen production for CD8⁺ T-cell activation and the flexibility to encode multi-stage fusion antigens targeting both active and latent bacilli. However, significant constraints remain; mRNA technology alone cannot resolve the spatial sequestration of Mtb within necrotic granulomas or the "recruitment lag" of systemic immunity to the lung parenchyma. Achieving sterile protection requires a transition toward mucosal delivery systems capable of inducing lung TRM cells. Furthermore, translational success must be measured beyond classical interferon-gamma (IFN-γ) readouts, prioritizing correlates of protection that reflect site-specific immunity, safety in latently infected populations, and the deployment of thermostable formulations in endemic regions. By integrating mRNA constructs into heterologous prime-boost regimens and host-directed therapies, the field moves toward a precision vaccinology framework capable of curtailing the TB epidemic.
We investigate the physical properties of a Dunkl black hole surrounded by a cloud of strings, a novel solution arising from a gauge theory of gravity based on the de Sitter group SO(4,1). The spacetime is characterized by the Dunkl deformation parameter ζ , which modifies the Schwarzschild metric via Dunkl operators, and the string cloud parameter α , introducing a dark energy-like contribution. We analyze the dynamics of massive test particles in the equatorial plane, deriving the effective potential, specific angular momentum, specific energy, and innermost stable circular orbit (ISCO), which reveal deviations from the Schwarzschild case due to ζ and α . The thermodynamic properties, including the Hawking temperature, Bekenstein-Hawking entropy, heat capacity, enthalpy, pressure, internal energy, and Gibbs free energy, are examined, highlighting quantum-gravity corrections and cosmological effects. Using the Novikov-Thorne model, we study the radiative properties of a thin accretion disk, computing the electromagnetic flux, temperature profile, and differential luminosity. The Dunkl deformation enhances flux and temperature near the ISCO, suggesting darker disks, while the string cloud reduces these quantities, indicating dimmer disks with broader inner edges. These findings, evident in X-ray spectra of BH binaries, provide a framework for constraining ζ and α and offer insights into quantum gravity, noncommutative geometries, and cosmological influences in modified spacetimes.
Abstract We investigate the geodesic motion and accretion disc signatures of the Kazakov–Solodukhin (KS) quantum-corrected black hole. This regular solution incorporates leading-order quantum effects into the Schwarzschild geometry. For massive test particles, we compute the innermost stable circular orbit (ISCO) together with the corresponding energy and angular momentum. We also derive the fundamental frequencies of radial and vertical oscillations and apply them to standard models of quasi-periodic oscillations (QPOs). In addition, we examine thin accretion discs using the Novikov–Thorne framework, focusing on the flux, temperature distribution, and spectral luminosity. Compared with the Schwarzschild case, the KS spacetime shows apparent differences in ISCO location, oscillation frequencies, and disc emission profiles, all of which are governed by the deformation parameter. By comparing our models with current observational QPO data, we show that this spherically symmetric spacetime cannot fit the data better than the Schwarzschild metric. Additionally, although the KS quantum-corrected black hole predicts distinct spectral properties, we cannot resolve the degeneracy between the quantum correction parameter and other astrophysical parameters (such as mass accretion rate, inclination angle, and black hole spin).
Single crystals of the organic–inorganic hybrid bis((pyridin-1-ium-3-yl)methanaminium) hexachlorostannate(IV) dichloride, ([3-PyCH2NH3]2[SnCl6]Cl2), were grown and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes as a centrosymmetric structure comprising discrete octahedral [SnCl6]2– anions linked to protonated organic cations through charge-assisted N–H···Cl hydrogen bonds, forming a stable supramolecular framework. Bond valence sum calculations confirm the + 4 oxidation state of tin, supporting the structural model. Diffuse reflectance spectroscopy reveals a wide optical bandgap of 4.28 eV, indicating insulating behavior typical of chloride-based hybrids. Photoluminescence measurements show near-ultraviolet emission at room temperature, attributed to ligand-centered electronic transitions within the organic component. Third-order non-linear optical measurements demonstrate a measurable χ(3) value on the order of 10–11 esu, suggesting significant electronic polarization despite the centrosymmetric lattice. Dielectric analysis indicates strong frequency and temperature-dependent behavior, with higher dielectric constants at low frequencies due to interfacial and space-charge polarization, followed by stabilization at higher frequencies. AC conductivity studies suggest a transition from polarization-dominated transport to thermally activated hopping conduction. Hirshfeld surface analysis confirms that N–H···Cl hydrogen bonding dominates crystal packing. These results demonstrate the key role of hydrogen-bond-driven organization in determining the optical and dielectric properties of this hybrid material.
