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Hydrogen has received a lot of attention and is regarded as the most promising energy source of the twenty-first century because of its high energy density and eco-friendliness. However, there are increasing concerns about its safe use, storage, and transportation. The present research study scrutinizes the chemi-resistive behavior of pure and Cu-doped TiO2 thin films that may be applied to the creation of hydrogen sensing devices. The spray technique was used to synthesize the samples with different levels of Cu content (0, 0.2 and 0.4 wt %) on thermally oxidized Si substrates. The samples were characterized by grazing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) analysis. The hydrogen chemi-resistive behavior of the samples was assessed and the sensing mechanism of the pure and doped samples was analyzed. The results showed that Cu-doping significantly affected the hydrogen sensing performance of the TiO2 thin films due to the increase of oxygen adsorption sites. The sample of 0.4 wt % Cu-doped TiO2 (the most sensitive sample) showed a response value of 2600% with a reaction time of 55 s to 1000 ppm of hydrogen at the operating temperature of 200 °C. It was also selective to H2 compared to CO2, NO2, NH3, and LPG. The evaluation of the reliability of the mentioned sample revealed that it can be considered as a potential for hydrogen sensing devices. [ABSTRACT FROM AUTHOR]

Maryam Dibaei,1 Mohammad-Reza Rouini,1 Behjat Sheikholeslami,1 Mahdi Gholami,2,3 Rassoul Dinarvand4,51Biopharmaceutics and Pharmacokinetic Division, Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 2Experimental Medicine Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 3Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 4Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 5Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranBackground: Curcumin, a bioactive component with multiple characteristics, has been shown to have many therapeutic effects. However, there are several limitations regarding the use of curcumin such as instability, low solubility, poor bioavailability, and rapid elimination. Different approaches have been used to solve these problems.Materials and methods: In this study, surface-modified nanosuspension (NS) is investigated as a novel brain delivery system. Two different methods were used for the preparation of nanosuspensions with two different stabilizers. The surface of the nanosuspensions was coated with D-α-tocopheryl polyethylene glycol 1,000 succinate (TPGS) and Tween 80 using physical adsorption. Curcumin NSs were prepared using two different top-down techniques by high-pressure homogenizer and probe sonicator. A validated sensitive and selective high-performance liquid chromatography method using fluorescence detection was used for the determination and quantification of curcumin. Pharmacokinetics and biodistribution of curcumin NSs and solutions after intravenous administration in rats were studied.Results: Higher levels of curcumin in the brain were detected when Tween 80-coated NS was used compared with the curcumin solution and TPGS coated NS (TPGS-NS) (P-value

There is a growing concern in countries around the world, including Iran, about the effects of extreme climate change, diversification, and events on food production, food security, and livelihoods. The link between climate change and food security in the Iranian food system is the subject of this article. This review, based on the available literature, used the food system approach to achieve a broader view on issues related to food security in Iran. To this end, this study investigated climatic challenges facing food security in Iran with a focus on two essential products in Iranians' food basket, namely, wheat and rice: Decreased agricultural productivity, food losses along production and distribution chains, postharvest loss, low resilience of poor people in rural areas, and the prevalence of malnutrition among children. The results showed that in addition to measures, such as making food production systems resistant to climate change and the necessary changes in existing food systems to adapt to the consequences of climate change, achieving food security requires a long-term vision to transform the Iranian food system. Accordingly, it is necessary to develop a climate-smart agriculture system that encompasses all aspects of food system security. Except for investigating the productivity of some essential components of this food basket, the results showed that there are scant studies on the effects of climate change on the food system of Iran. [ABSTRACT FROM AUTHOR]