Integration of Dynamic Growth Modeling and Hydrodynamics in an Internal-Loop Split Photobioreactor

In this study, new high-quality experimental data for culturing green microalgae Scenedesmus in tubular and cylindrical split airlift photobioreactors were obtained under different operating conditions. The obtained experimental data of culturing microalgae Scenedesmus in a tubular photobioreactor were used for determining the kinetic parameters of the photosynthetic reaction. On the other hand, the culturing of green microalgae in a split airlift photobioreactor was used to measure the microalgae cell trajectory using an advanced radioactive particle tracking (RPT) technique. The obtained results in terms of kinetic parameters of the photosynthetic reaction and microalgae cell trajectory were integrated for the first time to obtain the three-state dynamic growth model. This integration between dynamic growth and cell trajectories will provide a direct and comprehensive tool for photobioreactor analysis, which is essential for proper and efficient reactor design and scale-up for large-scale biomass production. © 2021 Society of Chemical Industry (SCI)

Self-reported post-vaccination side effects of each of the three rounds of COVID-19 vaccinations: the case in the Eastern Province, Saudi Arabia

Abstract The present study aimed to investigate the systemic short-term post-COVID-19 vaccine adverse events between three rounds of vaccination in Eastern Province, Saudi Arabia. Furthermore, to compare the incidence of these side effects between the three vaccine rounds. The present study was a prospective survey-based cross-sectional, conducted during the period of 1/4/2022 to 30/6/2022. The study has recruited all staff and students who have been vaccinated with all three doses of COVID-19 in Eastern Province, Saudi Arabia. The survey included three sections; The first section was participants' characteristics; The second section was a self-reported survey on 32 prespecified side effects; and the third section was data related to the type of COVID-19 vaccine. A total of 582 cases were analysed for the study. overall, most respondents were reporting no side effects across the three COVID-19 vaccine rounds. Meanwhile, eight side effect variables (fever, chills, fatigue, skipped meals, headache, nausea, sore throat and low mood) appear to be more manifested among the study sample to a small extent. However, these side effects are usually mild. When each side effect was further evaluated during the three rounds of protocol, sore throat had the highest median rating at the first round of vaccination. The result found that only the male gender was a significant negative predictor of the side effects after vaccine rounds. Our results indicated that the COVID-19 vaccine is well tolerated, and safe, most post-vaccination adverse effects in the three rounds are, generally mild in severity and rare with a lower frequency and number of reported side effects in males. Further studies are needed to understand the relationship between the possible health risk factors and COVID-19 side effects

Subacute toxicity of Chrozophora Tinctoria extract: biochemical and histopathological changes in rats

Abstract The increasing use of medicinal plants in traditional and modern therapies necessitates thorough toxicological evaluations to ensure their safety. Chrozophora genus includes 7-8 species that belong to the Euphorbiaceae family, distributed in Pakistan, India, West Africa, and the Mediterranean with four species found in the Kingdom of Saudi Arabia (KSA). This study evaluates the subacute toxicity of the ethyl acetate extract (EtOAcE) of Chrozophora tinctoria in male and female rats. Over 14 days, rats were daily administered the extract at doses of 50, 100, and 200 mg. Mortality was observed at a rate of one rat per group. Female rats showed a significant reduction in body weight, while organ weights remained unaffected. Kidney function tests revealed significant increases in bilirubin and creatinine levels in male rats at 200 mg, and uric acid levels in female rats at the same dosage. Liver enzyme analysis indicated significant elevations in ALP, ALT, and GGT levels in both sexes at various dosages. Glucose levels increased significantly in female rats at 200 mg/kg, with no significant changes in cortisol levels in either sex. Histopathological examinations demonstrated notable abnormalities in liver, kidney, spleen, and small intestine tissues. These data demonstrate the essentiality of careful evaluation and monitoring when considering C. tinctoria for medicinal use, highlighting the need for further studies on its long-term safety and therapeutic index

Phytic acid attenuates acetaminophen-induced hepatotoxicity via modulating iron-mediated oxidative stress and SIRT-1 expression in mice

Introduction: Administration of high doses of acetaminophen (APAP) results in liver injury. Oxidative stress and iron overload play roles in the pathogenesis of APAP-induced hepatotoxicity. The present study assessed the potential hepatoprotective effects of phytic acid (PA), a natural antioxidant and iron chelator, on APAP-induced hepatotoxicity and the possible underlying mechanism through its effects on CYP2E1 gene expression, iron homeostasis, oxidative stress, and SIRT-1 expression levels.Methods: Twenty-four adult male albino mice were used in this study. Mice were divided into four groups (six mice in each group): control, APAP-treated, PA-treated and APAP + PA-treated groups. Liver function tests, serum and liver tissue iron load were evaluated in all the study groups. Hepatic tissue homogenates were used to detect oxidative stress markers, including malondialdehyde (MDA) and reduced glutathione (GSH). Histological hepatic evaluation and immunohistochemistry of SIRT-1 were performed. Quantitative real-time PCR was used for the assessment of CYP2E1 and SIRT-1 gene expressions. APAP-induced biochemical and structural hepatic changes were reported.Results: PA administration showed beneficial effects on APAP-induced hepatotoxicity through improvements in liver functions, decreased CYP2E1 gene expression, decreased serum and liver iron load, decreased MDA, increased GSH, increased SIRT-1 expression level and improvement in hepatic architecture.Conclusion: Conclusively, PA can be considered a potential compound that can attenuate acetaminophen-induced hepatotoxicity through its role as an iron chelator and antioxidant, as well as the up-regulation of SIRT-1 and down-regulation of CYP2E1

Continuous-flow liquid-phase dehydrogenation of 1,4-cyclohexanedione in a structured multichannel reactor

A highly selective, scalable and continuous-flow process is developed for the liquid-phase dehydrogenation of 1,4-cyclohexanedione to hydroquinone in a millimetre-scale structured multichannel reactor. The square shaped channels (3 mm × 3 mm) were filled with 10 wt% Pd/C catalyst particles and utilized for the dehydrogenation reaction in single-pass and recycle modes. For the purpose to enhance process understanding and to maximize conversion and selectivity by process optimization, Design of Experiment (DoE) methodology was utilized by studying the effect of operating parameters on the catalytic performance in kinetic regime. The results demostrated the strong influence of temperature and liquid feed flow on the conversion and selectivity, with liquid feed and N₂ flows influencing pressure drop significantly. A multi-objective optimization methodology was used to identify the optimum process window with the aid of sweet spot plots, with design space plots developed to establish acceptable boundaries for process parameters. In single-pass mode, complete conversion per pass per channel was not achievable whereas conversion increased from 59.8% in one-channel to 78.3% for two-channel-in-series while maintaining selectivity (> 99%) with intermediate hydrogen removal. However, for without intermediate H₂ removal step, selectivity was declined from > 99% in one-channel to 82.3% at the outlet of second-channel. In recycle mode, dehydrogenation reaction was resulted in almost complete conversion (> 99%) with very high selectivity (> 99%) and yield (> 98%). This combination of mm-scale multichannel reactor and DoE methodology opens the way to developing highly selective and scalable dehydrogenation proocesses in the fine chemical and pharmaceutical industries

Multiobjective Optimization Ofautothermal Catalytic Membrane Reactor using Genetic Algorithm

Membrane reactors combined reaction with separation to increase the conversion. Dehydrogenation of ethyl benzene and hydrogenation of nitrobenzene was coupled in the catalytic shell and tubes membrane reactor, so the conversion and yield of the limited dehydrogenation reaction ethyl benzene can be significantly enhanced. the reactor system needs to be optimized to achieve the maximum benefit. the optimization problem of the present work was to maximize the conversion of the nitrobenzene and the yield of the styrene. Six decision (process) variables were studied which are; ethyl & nitro benzene flow rate, pressure and temperature on shell and tubes side .The flow rate of nitro benzene was the effective variable on the conversion of nitrobenzene while the flow rate of ethyl benzene was to be considered as the effective variable on the styrene yield. the mathematical correlations based optimization could be implemented to find the optimum parameters. Optimization technique was the powerful tool to generate several new designs and sets of operating conditions. This reduces the number of experimental runs and the consumed cost for the design and operation. the present optimization search introduced the following improvements to the reactor process:-Reduced the number of manipulated (decision) variables that effecting on the efficiency of the reactor to 6 instead of 12 which considered previously. These eliminate the complexity in the optimization problem and reduced the computing time.-Yield of styrene could be obtained within the range of (74 to100%) compared to the previous work which was within of (49 to 98%) for the same operating conditions. the success of the optimization search was due to:-Good formulation of the steady state objective functions since the objectives were correlated directly to the decision variables. the static formula was more accurate than the dynamic mode for the process of long cycle time of reaction.-For highly nonlinear membrane reactor, the stochastic optimization algorithm was better than the deterministic methods used by the previous work which were limited and inaccurate for nonlinear interacting process. in the present work, the Genetic algorithm was the best stochastic technique and global solution for nonlinear interacting membrane reactor process. the accuracy of Genetic algorithm can be increased by adaption the operators of the Genetic algorithm. Keywords: Chemical Reaction, Genetic Algorithm, Membrane Reactor, Optimization

The Relationship Between Vitamin D Serum Levels and Rheumatoid Arthritis Activity in a Sample of Syrian Patients- a cross-sectional observational study

Abstract Background. Rheumatoid Arthritis (RA) is a systemic auto immune disease that mainly affects joints. It might cause functional disability and increased morbidity and mortality.Vitamin D was reported to have an immunomodulation role in reducing the inflammation process in many auto immune diseases; RA is one of them.The aim was to determine the relationship between serum vitamin D levels and rheumatoid arthritis activity in a sample of Syrian patients.Methods This cross-sectional observational study was carried out in Al-Mouwasat and Al-Assad University Hospitals(Damascus University - Syria). RA patients were diagnosed according to the American College of Rheumatology (ACR) and the European League Against Rheumatism(EULAR)classification criteria for rheumatoid arthritis 2010 standards.Results Vitamin D was significantly higher in RA patients in remission (27.92 ± 13 ng/ml) than in patients with active RA (21.22 ± 13 ng/ml). There was an inverse relationship between serum vitamin D levels and RA activity.Conclusion Serum vitamin D levels were inversely correlated with RA activity in a sample of Syrian RA patients.</jats:p