Modeling Thermochemical Solar‐to‐Fuel Conversion: CALPHAD for Thermodynamic Assessment Studies of Perovskites,Exemplified for (La,Sr)MnO3

Two‐step solar thermochemical fuel production has the potential to reduce global greenhouse gas emissions and replace fossil fuels. The success of the technology relies on the development of materials with high thermochemical efficiency. Perovskites with the general structure ABO₃ have received much attention recently due to impressive fuel productivity and their amenability of substituting and doping both A‐ and B‐site. Despite the potential of perovskites for solar‐to‐fuel conversion, literature on their solar thermochemical efficiency is scarce and finding the best chemical composition and optimum operation conditions is unknown. For this purpose, this study suggests to use Computer Coupling of Phase Diagrams and Thermochemistry (CALPHAD) data libraries to access the relevant thermodynamic properties of perovskites. This work demonstrates the usefulness of employing CALPHAD data by a full thermodynamic study of the model case compositions of La_1–xSr_xMnO_3–δ. This study uses data on oxygen‐nonstoichiometry and heat capacity in the temperature range of 1073–1873 K relevant for solar‐to‐fuel. Unlike earlier thermodynamic assessments of perovskites that rely on a single literature source and a limited temperature range, the CALPHAD approach takes all available data in literature into consideration. Thermochemical equilibrium models of fuel yields are accompanied by validations toward experimental results in literature, and this study highlights the effects of strontium doping level on the efficiency.     

Auxin, Gibberellin, Cytokinin and Abscisic Acid Production in Some Bacteria

Summary In this study, auxin (indole-3-acetic acid), gibberellin, cytokinin (zeatin) and abscisic acid production were investigated in the culture medium of the bacteria Proteus mirabilis, P. vulgaris, Klebsiella pneumoniae, Bacillus megaterium, B. cereus, Escherichia coli. To determine the levels of these plant growth regulators, high performance liquid chromatography (HPLC) technique was used. Our findings show that the bacteria used in this study synthesized the plant growth regulators, auxin, gibberellin, cytokinin and abscisic acid.     

Investigation of Heavy Metal Level and Mineral Nutrient Status in Widely Used Medicinal Plants’ Leaves in Turkey: Insights into Health Implications

The use of plants in treatments has been as old as humanity and it has preserved its popularity for centuries til now because of their availability, affordability and safeness. However, despite their widespread use, safety and quality issues have been major concerns in the world due to industrial- and anthropogenic-based heavy metal contamination risks. Thus, this study was attempted to analyze the heavy metal levels and mineral nutrient status of widely used medicinal plants in Turkey to have insights about their health implications on humans. The plant concentrations of B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn were analyzed by ICP-OES in the leaves of 44 medical plants purchased from herbal markets of three different districts of Istanbul/Turkey. The measured lowest to highest concentrations were 0.065–79.749 mg kg⁻¹ B, 921.802–12,854.410 mg kg⁻¹ Ca, 0.020–0.558 mg kg⁻¹ Cd, 0.015–4.978 mg kg⁻¹ Cr, 0.042–8.489 mg kg⁻¹ Cu, 34.356–858.446 mg kg⁻¹ Fe, 791.323–15,569.349 mg kg⁻¹ K, 102.236–2837.836 mg kg⁻¹ Mg, 4.915–91.519 mg kg⁻¹ Mn, 10.224–3213.703 mg kg⁻¹ Na, 0.001–5.589 mg kg⁻¹ Ni, 0.003–3.636 mg kg⁻¹ Pb and 2.601–36.102 mg kg⁻¹ Zn. Those levels in plants were in acceptable limits though some elements in some plants have high limits which were not harmful. Variations (above acceptable limits) in element concentrations also indicated that these plants could be contaminated with other metals and that genetic variations may influence accumulation of these elements at different contents. Overall, analyzed medicinal plants are expected not to pose any serious threat to human health.

     

Fatal disseminated cytomegalovirus infection in an infant with Cushing's syndrome caused by topical steroid

Corticosteroids, even in topical application, may cause immunosuppression and Cushing's syndrome. A case of disseminated fatal cytomegalovirus infection is reported in a 3-month-old girl with Cushing's syndrome caused by exogenous topical clobetasol propionate application, which might have caused immunosuppression due to prolonged use.     

Prevalence of sleep disorders in the Turkish adult population epidemiology of sleep study

Sleep and Biological Rhythms - Sleep disorders constitute an important public health problem. Prevalence of sleep disorders in Turkish adult population was investigated in a nationwide...     

Anticarcinogenic effects of halofuginone on lung‐derived cancer cells

Malignant mesothelioma is a rare but aggressive form of malignancy, which is difficult to diagnose and is resistant to current chemotherapeutic treatment options. Molecular techniques have been used to investigate the mechanisms of action and the beneficial therapeutic effects of halofuginone (HF) in several cancers but not malignant mesotheliomas. In this study, the antiproliferative and apoptotic effects of HF were investigated through its ability to deregulate EGFR downstream signalling cascade proteins in the pathologically aggressive malignant mesothelioma and non‐small‐cell lung cancer cells. We showed that administration of HF at nanomolar concentrations induced a dose‐dependent reduction in the viability of cancer cells, made cell cycle arrest, inhibited proliferation of cancer cells via STAT3 and ERK1/2 pathways and triggered the apoptotic cascade via p38MAPK. We demonstrated that the apoptotic cell death mechanism was mediated by enhanced activation of caspase‐3 and concomitant PARP cleavage, downregulation of Bcl‐2 and upregulation of Bax in both malignant mesothelioma and lung cancer cells. In particular, we demonstrated that cancer cells were more sensitive to HF treatment than normal mesothelial cells. Taken together, this study suggests that HF exerts its anticancer effects in lung‐derived cancers by targeting signal transduction pathways mainly through deregulation of ERK1/2, STAT3 and p38MAPK to reduce cancer cell viability, induce cell cycle arrest and apoptotic cell death. Thus, HF might be considered as a potential agent against malignant mesothelioma and/or lung cancer cells.