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Fenofibrate nano-suspension formulation using hot melt emulsion followed by precipitation
No full textFenofibrate is a pharmaceutical drug of the fibrate class, which is used to lower abnormal lipid levels in the blood. However, fenofibrate suffers from poor bioavailability due to its hydrophobic nature and negligible water solubility. The generation of nanosuspension with increased surface area is one of the mechanisms to minimize this challenge. In this work, fenofibrate nanosuspension was formulated to improve the solubility of the drug. A method of hot melt emulsification followed by precipitating the hot melt into a cold aqueous medium was employed to generate the nanosuspension. Ultrasound energy and stabilizers such as Hydroxymethyl cellulose (HPMC), Polyvinyl Pyrrolidone (PVP), and Bovine Serum Albumin (BSA), along with surfactants including Tween 80 (T80) and Sodium Lauryl Sulphate (SLS), were used to control particle growth and improve the stability of the resulting suspension. Sunflower oil was used as a co-additive agent. The effects of surfactants, ultrasound energy and sonication time, drug to surfactant ratio, and sunflower oil on particle size and suspension stability were investigated. The use of ultrasound sonication during both the hot-melt formation step and the precipitation step produced smaller particle sizes. A ground mixture of fenofibrate with BSA and SLS, in the presence of 3 mL sunflower oil, produced a nanosuspension with particle sizes below 100 nm, exhibiting a relatively lower particle growth rate and improved stability. Using a lower molecular weight BSA surfactant and incorporating sunflower oil produced substantial improvement in the particle size reduction and enhancement of the suspension's stability
TOI-6038 A b: A Dense Sub-Saturn in the Transition Regime between the Neptunian Ridge and Savanna
No full textWe present the discovery and characterization of a sub-Saturn exoplanet, TOI-6038 A b, using the PARAS-2 spectrograph. The planet orbits a bright (mV = 9.9), metal-rich late F-type star, TOI-6038 A, with Teff = 6110 ± 100 K, log g = 4.11 8 − 0.025 + 0.015 , and [ Fe/H ] = 0.12 4 − 0.077 + 0.079 dex. The system also contains a wide-orbit binary companion, TOI-6038 B, an early K-type star at a projected separation of ≈3217 au. We combined radial velocity data from PARAS-2 with photometric data from the Transiting Exoplanet Survey Satellite for joint modeling. TOI-6038 A b has a mass of 78 . 5 − 9.9 + 9.5 M ⊕ and a radius of 6.4 1 − 0.16 + 0.20 R ⊕ , orbiting in a circular orbit with a period of 5.826731 1 − 0.0000068 + 0.0000074 days. Internal structure modeling suggests that ≈74% of the planet's mass is composed of dense materials, such as rock and iron, forming a core, while the remaining mass consists of a low-density H/He envelope. TOI-6038 A b lies at the transition regime between the recently identified Neptunian ridge and savanna. Having a density of ρ P = 1.6 2 − 0.24 + 0.23 g cm − 3 , TOI-6038 A b is compatible with the population of dense ridge planets (ρP ≃ 1.5-2.0 g cm−3), which have been proposed to have reached their close-in locations through high-eccentricity tidal migration (HEM). First-order estimates suggest that the secular perturbations induced by TOI-6038 B may be insufficient to drive the HEM of TOI-6038 A b. Therefore, it is not clear whether HEM driven by a still undetected companion or early disk-driven migration brought TOI-6038 A b to its present-day close-in orbit. Interestingly, its bright host star makes TOI-6038 A b a prime target for atmospheric escape and orbital architecture observations, which will help us to better understand its overall evolution
Integrated approach for efficient adaptive underdetermined DOA estimation: coarray LMS with covariance matrix error removal
No full textUnderdetermined direction of arrival (U-DOA) estimation relies on the higher degrees of freedom provided by the difference coarray of a non-uniform linear array. The coarray domain signal is obtained by vectorizing the array covariance matrix, which is estimated using array signals from multiple snapshots. However, in low snapshot scenarios, errors arise in the covariance matrix due to non-zero off-diagonal elements in the signal and noise covariance matrices, degrading UDOA estimation performance. This work proposes an integrated approach combining a novel covariance matrix error removal technique with the adaptive Coarray LMS and subspace-based Coarray MUSIC U-DOA estimation methods. Our method uses a matrix decomposition based approach to estimate a sparse, full-rank covariance matrix while removing low-rank residual errors caused by low snapshots. Unlike conventional methods, we treat the sparse matrix as the desired covariance matrix, addressing low-snapshot underdetermined scenarios. Additionally, we introduce a novel computationally efficient gridless approach to obtain the DOA spectrum by analyzing weights in the Fourier domain. Simulations validate the improved U-DOA estimation performance of the proposed method in low snapshot scenarios
Investigation of Resistive Switching in Au/MoS₂/Au Using Reactive Molecular Dynamics and ab-initio Quantum Transport Calculations
No full textIn this work, we investigate the underlying physical mechanism for electric-field induced resistive switching in Au/MoS2/Au based memristive devices by combining reactive Molecular Dynamics (MD) and ab-initio quantum transport calculations. Using MD with Au/Mo/S ReaxFF potential, we observe the formation of realistic conductive filament consisting of gold atoms through monolayer MoS2 layer when sufficient electric field is applied. We furthermore instigate the rupture of the gold atom filament when a sufficiently large electric field is applied in the opposite direction. To calculate the conductance of the obtained structures and identify the High Resistance (HR) and Low Resistance (LR) states, we employ the ab-initio electron transport calculations by importing the atomic structures from MD calculations. For single-defect MoS2 memristors, the obtained LRS, HRS current densities are in order of 107 A/cm2 which agrees reasonably well with the reported experiments
Sign regularity preserving linear operators
No full textA matrix (Formula presented.) is strictly sign regular (or sign regular) if for each (Formula presented.), all (nonzero) (Formula presented.) minors of (Formula presented.) have the same sign. This class of matrices contains the totally positive matrices, and was first studied by Schoenberg in 1930 to characterize variation diminution, a fundamental property in total positivity theory. In this article, we classify all surjective linear mappings (Formula presented.) that preserve: (i) sign regularity and (ii) sign regularity with a given sign pattern, as well as (iii) strict versions of these
Investigating non-local contributions in Bs→ϕℓ¯ℓ including higher-twist effects
No full textWe analyze the impact of higher-twist three-particle Bs-meson light-cone distribution amplitudes (LCDAs) on the non-local form factors for the Bs→ϕℓ¯ℓ transition focusing on the 'charm-loop' contribution within the light-cone sum rule (LCSR) framework. To analytically continue these charm-loop contributions into the kinematically allowed region of the decay, we employ a hadronic dispersion relation that incorporates intermediate resonant states such as the ϕ, J/Ψ and ψ(2S) mesons. Here, the LCSR predictions serve as inputs, supplemented by experimental data from two-body decays Bs→ϕ + resonance states. Our results indicate that the inclusion of twist-5 and twist-6 LCDAs enhances the non-local form factors−by approximately an order of magnitude−compared to previous estimates, due to partial disruption of cancellation among different twist contributions. This leads to a dilepton invariant mass-squared (q2−)dependent correction to the Wilson coefficient C9, which is higher than, but still consistent with the Standard Model prediction within uncertainties. Additionally, we update the local form factors to include contributions from higher-twist three-particle Bs−meson LCDAs. The phenomenological implications, particularly for the differential branching fraction and angular observables, are also discussed
Constraining the 3HDM parameter space using active learning
No full textOne of the standard ways to study scenarios beyond the Standard Model involves extending the Higgs sector. This work examines the three Higgs doublet model (3HDM) in a type-Z or democratic setup, where each Higgs doublet couples exclusively to a specific type of fermion. The particle spectrum of the 3HDM includes four charged Higgs bosons, two -odd scalars, and three -even scalars. This work investigates the allowed mass and coupling parameter space in the type-Z 3HDM after imposing all theoretical and experimental constraints. We extract the allowed parameter space under three distinct alignment-limit conditions or mass hierarchies leveraging machine learning techniques. Specifically, we analyze scenarios where the 125 GeV Higgs is the lightest, an intermediary, or the heaviest -even Higgs boson. Our findings indicate that while a single lighter -even Higgs boson below 125 GeV still remains a possibility, the presence of two lighter Higgses is ruled out
