Physicochemical Characterization and Dissolution Properties of Meloxicam-Gelucire 50/13 Binary Systems

A solid dispersion of Meloxicam (MX), a poorly soluble, non steroidal anti-inflammatory drug, and Gelucire 50/13 was prepared by spray drying. Spherical microparticles were yielded with smooth surfaces as observed by scanning electron microscopy. According to differential scanning calorimetry and powder X-ray diffractometry analysis, MX was transformed from the crystalline state to the amorphous state as confirmed by the disappearance of its melting peak and the crystalline peaks. The dissolution tests at pH 7.4 revealed that the dissolution rate of encapsulated MX was 2.5-fold higher than that of the corresponding physical mixture and fourfold higher than the drug alone, respectively. The microparticles prepared at a ratio of 1:4 (drug/Gelucire) exhibited a 4-fold higher anti-inflammatory activity on the paw edema of rats in comparison to the drug alone. All in all, this work reveals that spray drying is a suitable technique for preparation of solid dispersions with improved biopharmaceutical and pharmacological characteristics of MX

Serum Malondialdehyde Levels as a Biomarker of Cellular Injury In Human Fascioliasis

AbstractMacrophages, neutrophils and other phagocytic cells are key components of the antiparasitic, antimicrobial and tumoricidal immune responses. These cells are capable of generating large amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS have a possible role in the pathogenesis of parasitic disease. Lipid peroxidation is a well-established mechanism of cellular injury and is used as an indicator of oxidative stress in cells and tissues. To examine oxidant status and lipid peroxidation in fascioliasis patients, the malondialdehyde (MDA) (an end-product of lipid peroxidation) has been studied. Serum MDA level was measured in 34 patients infected with Fasciola gigantica and their age and gender were matched to 36 healthy controls. The difference between MDA levels of patients infected with Fasciola gigantica and the control group was statistically significant both in females (P<0.05) and males (P<0.05) with no correlation between age and MDA levels both in females and males of patient and control group. The high infection/control ratio of MDA concentration and the significant correlation strongly indicate the occurrence of oxidative stress and lipid peroxidation as a mechanism of tissue damage in cases of F. gigantica infection

Constraints on the cosmological coupling of black holes from Gaia

Recent work has suggested that black holes (BHs) could be cosmologically coupled to the accelerated expansion of the universe, potentially becoming a candidate for dark energy. This would imply BH mass growth following the cosmological expansion, with the masses of individual BHs growing as $M_{\rm BH}\propto (1+z)^3$. In this letter, we discuss the binary systems Gaia BH1 and Gaia BH2, which contain $\sim 9\,M_{\odot}$ BHs orbited by $\sim 1\,M_{\odot}$ stars in widely-separated orbits. The ages of both systems can be constrained by the properties of the luminous stars. If BH masses are indeed growing as $(1+z)^3$, the masses of both BHs at formation would have been significantly smaller than today. We find a 77% probability that the mass of the BH in Gaia BH2 would have been below $2.2M_\odot$ at formation. This is below the classical Tolman-Oppenheimer-Volkov limit, though it is not yet clear if BHs subject to cosmological coupling should obey this limit. For Gaia BH1, the same probability is 70%. This analysis is consistent with results from two BHs in the globular cluster NGC3201, but unlike the NGC3201 BHs, the Gaia BHs have well-constrained inclinations and thus firm upper mass limits. The discovery of more BHs in binary systems with Gaia astrometry in the coming years will allow us to test the cosmological coupling hypothesis decisively.Comment: submitted 8th March 2023; accepted 2nd May 2023; 4 pages, 3 figure

Semiclassical Hartree-Fock theory of a rotating Bose-Einstein condensation

In this paper, we investigate the thermodynamic behavior of a rotating Bose-Einstein condensation with non-zero interatomic interactions theoretically. The analysis relies on a semiclassical Hartree-Fock approximation where an integral is performed over the phase space and function of the grand canonical ensemble is derived. Subsequently, we use this result to derive several thermodynamic quantities including the condensate fraction, critical temperature, entropy and heat capacity. Thereby, we investigate the effect of the rotation rate and interactions parameter on the thermodynamic behavior. The role of finite size is discussed. Our approach can be extended to consider the rotating condensate in optical potential

Imprints of white dwarf recoil in the separation distribution of Gaia wide binaries

We construct from Gaia DR2 an extensive and very pure ($\lesssim 0.2\%$ contamination) catalog of wide binaries containing main-sequence (MS) and white dwarf (WD) components within 200 pc of the Sun. The public catalog contains, after removal of clusters and resolved higher-order multiples, $>$50,000 MS/MS, $>$3,000 WD/MS, and nearly 400 WD/WD binaries with projected separations of $50 \lesssim s/{\rm AU} < 50,000$. Accounting for incompleteness and selection effects, we model the separation distribution of each class of binaries as a broken power-law, revealing marked differences between the three populations. The separation distribution of MS/MS systems is nearly consistent with a single power-law of slope $-1.6$ over at least $500 < s/{\rm AU} < 50,000$, with marginal steepening at $s > 10,000$ AU. In contrast, the separation distributions of WD/MS and WD/WD binaries show distinct breaks at $\sim$ 3,000 AU and $\sim$1,500 AU, respectively: they are flatter than the MS/MS distribution at small separations and steeper at large separations. Using binary population synthesis models, we show that these breaks are unlikely to be caused by external factors but can be explained if the WDs incur a kick of $\sim$ 0.75 km s$^{-1}$ during their formation, presumably due to asymmetric mass loss. The data rule out typical kick velocities above 2km s$^{-1}$. Our results imply that most wide binaries with separations exceeding a few thousand AU become unbound during post-MS evolution.Comment: Accepted to MNRAS. 15 pages, 11 figures, plus appendices. Catalog available at https://sites.google.com/site/dr2binaries200pc/dat