Inflationary f(R) cosmologies

This paper discusses a simple procedure to reconstruct f (R)-gravity models from exact cosmological solutions of the Einstein field equations with a noninteracting classical scalar field-and-radiation background. From the kind of inflationary scenario we want, we show how the potential functions can be obtained. We then show how an f (R) gravitational Lagrangian density that mimics the same cosmological expansion as the scalar field-driven inflation of General Relativity can be reconstructed. As a demonstration, we calculate the slow-roll parameters (the spectral index n s and the tensor-to-scalar ratio r) and compare them to the Planck data.Comment: 13 pages, 10 figure

Cosmic hierarchy in f(R)f(R) gravity

In this contribution, we investigate hierarchical nature of large-scale structure clustering through the oscillatory nature of the solutions of the Schr\"{o}dinger-like Friedmann equation in a modified gravitational background described by the $f(R)$ gravity theory. We find the cosmological solutions to the Schr\"{o}dinger equation for different ranges of $n$ of the $R^{n}$ toy model for both radiation and matter-dominated epochs of the expansion history for open, flat, and closed spacetimes. Our results show that, for certain choices of the model parameters and initial conditions, the formation and distribution of cosmic structures might indeed be hierarchical, leading to a natural explanation for the breakdown of the cosmological principle on small scales.Comment: 15 pages and 20 figure

Light and electron microscopic study on the effect of antischizophrenic drugs on the structure of seminiferous tubules of adult male albino rats

Introduction. Sexual dysfunction and infertility are symptoms which have been rarely studied in patients treated with antischizophrenic drugs, aripiprazole and olanzapine, for long period. This work aimed to investigate the effects of aripiprazole and olanzapine on the structure of seminiferous tubules of rats at both light microscopic and ultrastructural levels. Material and methods. Sixty adult male rats were divided into 3 groups (n = 20): control group (Group I) and two experimental ones (II and III). Rats in Group II received 2 mg/kg/day aripiprazole while rats in Group III received 0.5 mg/kg/day olanzapine for 14 weeks. Thereafter, testis were removed and processed for both light and electron microscopic study. Qualitative morphological analyses and histomorphometric measurements of seminiferous tubules were performed. Results. Rats in Group II showed reduction of testicular weight, seminiferous tubules’ diameter, epithelial height, spermatogenic count, spermatogenic index and spermatogenic score whereas Sertoli cells count was increased. Olanzapine-treated rats also showed epithelial desquamation, separation and apoptotic changes of germ cells. Sertoli cells showed vacuolization, dilatation of smooth endoplasmic reticulum and accumulation of lipid droplets. Abnormality in the shape and structure of late spermatids and presence of giant cells were also demonstrated. Aripiprazole induced less adverse histological changes in rat testis than olanzapine. Conclusions. Olanzapine followed by aripiprazole had adverse histological effects on the structure of the semi­niferous tubules, which may affect spermatogenesis

Isotherms, Kinetics and Thermodynamic Mechanism of Methylene Blue Dye Adsorption on Synthesized Activated Carbon

The treatment of methylene blue (MB) dye wastewater through the adsorption process has been a subject of extensive research. However, a comprehensive understanding of the thermodynamic aspects of dye solution adsorption is lacking. Previous studies have primarily focused on enhancing the adsorption capacity of methylene blue dye. This study aimed to develop an environmentally friendly and cost-effective method for treating methylene blue dye wastewater and to gain insights into the thermodynamics and kinetics of the adsorption process for optimization. An adsorbent with selective methylene blue dye adsorption capabilities was synthesized using rice straw as the precursor. Experimental studies were conducted to investigate the adsorption isotherms and models under various process conditions, aiming to bridge gaps in previous research and enhance the understanding of adsorption mechanisms. Several adsorption isotherm models, including Langmuir, Temkin, Freundlich, and Langmuir-Freundlich, were applied to theoretically describe the adsorption mechanism. Equilibrium thermodynamic results demonstrated that the calculated equilibrium adsorption capacity (qe) aligned well with the experimentally obtained data. These findings of the study provide valuable insights into the thermodynamics and kinetics of methylene blue dye adsorption, with potential applications beyond this specific dye type. The utilization of rice straw as an adsorbent material presents a novel and cost-effective approach for MB dye removal from wastewater

Effects of implantation of bone marrow cells on cytokine levels in the ischemic heart tissue. An experimental study

<p>Abstract</p> <p>Background</p> <p>In order to achieve a safe and persistent angiogenic effect, we investigated the potential of bone marrow cells implantation to enhance angiogenesis of ischemic hearts in a rat model, and also we have investigated growth factors accompanying and intermediating the angiogenesis, and the changes occurring in the levels of cytokines and their relations with angiogenesis.</p> <p>Methods</p> <p>30 adult male Wistar albino rats from the same colony were used. After anterior myocardial infarction induced by occlusion of the left anterior descending artery, they were divided into two groups (Group I and Group II). 2 × 10⁷bone marrow cells suspended in 0.1 ml phosphate-buffered saline solution and 0.1 ml phosphate-buffered saline solution were injected at six points in the infarcted area in Group I and Group II respectively. Changes in the vascular density and, vascular endothelial growth factor, vascular cell adhesion molecule and cytokine levels in the infarcted myocardium after bone marrow cells implantation were examined.</p> <p>Results</p> <p>The implantation assay showed that bone marrow cells induced angiogenesis. Light microscopic analysis of the vascular density in the ischemic area showed that, angiogenesis had been induced to higher in Group I than Group II. Levels of vascular endothelial growth factor, vascular cell adhesion molecule and the inflammatory cytokines such as interleukin-1 and tumor necrosis factor-α in Group I were significantly elevated compared with those in Group II.</p> <p>Conclusion</p> <p>Bone marrow cells implantation induced angiogenesis in a rat ischemic heart model as a result of increase of the levels of vascular endothelial growth factor, vascular cell adhesion molecule, interleukin-1, and tumor necrosis factor-α.</p

The Epidemiology and Outcome of Biliary Atresia: Saudi Arabian National Study (2000–2018)

BackgroundThe epidemiology and outcomes of biliary atresia (BA) have been well-documented in national cohorts from two main ethnicities, namely, the Asian Orientals and Caucasians, with incidence ranging from 1 in 5,000 to 1 in 9,000 live births in East Asia and 1 in 15,000 to 19,000 live births in Europe and North America.ObjectiveWe report the first nationwide BA study outside North America, Europe, and East Asia to describe the epidemiology and outcomes of BA in Saudi Arabia.MethodsA national database of BA cases diagnosed between 2000 and 2018 was analyzed. We assessed clearance of jaundice (bilirubin &lt;20 μmol/L) in all cases that underwent Kasai portoenterostomy (KPE). We then estimated survival using the Kaplan–Meier method with endpoints of liver transplantation (LT), death, or survival with native liver (SNL).ResultsBA was diagnosed in 204 infants (106 females; 10% pre-term). The incidence of BA was 1 in 44,365, or 2.254 in 100,000 live births (range, 0.5–4 in 100,000). Polysplenia was diagnosed in 22 cases (11%). The median age at referral was 65 days. A total of 146 children (71.5%) underwent KPE at a median age of 70 days. Clearance of jaundice was achieved in 66 of the 146 (45%) infants. The 10-year SNL after KPE was 25.5%, and the overall 10-year estimated survival was 72.5%. The Kaplan–Meier survival curves for patients undergoing KPE at the age of &lt;60, 61–90, and &gt;90 days showed a SNL rate at 51.6, 33, and 12.5%, respectively, at 5 years (P &lt; 0.001). The 2-, 5-, and 10-year post-LT survival rates were 92.5, 90.6, and 90%, respectively. Undergoing an initial KPE did not impact negatively on the overall LT survival rate when compared to BA cases that underwent primary LT (P = 0.88).ConclusionThe incidence rate of BA in Saudi Arabia is lower than the incidence reported elsewhere. Late referral of BA cases remains a problem in Saudi Arabia; as a result, the SNL rate was lower than reported by other national registries. Hence, national policies devoted to timely referral and earlier age at KPE are needed