A novel method for fabricating conductive microfibers for microbial fuel cells

The increasing demand for energy resources has urged scientists to focus on improving the renewable energy sources. Microbial fuel cells (MFCs) have received an increasing attention. Both energy conversion mechanism and electrode type have attributed to affect the efficiency of the microbial fuel cells. Electrodes as one of the most important components of the microbial fuel cells have been widely investigated. While most of the electrode materials are carbon based, there is very little effort on introducing novel materials for this purpose. This paper intends to shed an insight on the effect of using a new cathode material on the performance of microbial fuel cells. We employ hydrodynamic forces to control both molecular organization and microstructure size and shape in order to create highly structured microfibers. A microfluidic sheath flow device is used for the fabrication processes. The core flow is acrylate solution and UV light cures the photoinitiator to start the polymerization process. The exiting stream goes inside a water bath, where the sheath flow dissolves in the DI water and the core flow forms the microfibers. Controlled self-assembly can be used to deposit a thin layer of functionalized metal nanoparticles on the polymeric structure made from microfibers to enhance their electric conductivity. A conductive and porous network formed by the microfibers can be used as an efficient cathode material in microbial fuel cells. Furthermore, using this fabrication technique we can make microfibers with different shapes and sizes

Outline of changes in cortisol and melatonin circadian rhythms in the security guards of Shiraz University of Medical Sciences

Background: According to the literature, a large number of people working in industries and service providing personnel, such as firefighters, physicians, and nurses are shift workers. The spread of shift working in industrial societies and the incidence of the problems resulting from shift working have caused the researchers to conduct studies on this issue. The present study also aimed to investigate melatonin and cortisol circadian rhythms in the security guards of Shiraz University of Medical Sciences, Shiraz, Iran. Methods: The present study was conducted on 20 security guards of Shiraz University of Medical Sciences. In order to collect the study data, blood samples were taken from the study subjects in different times of the day (1, 4, 7, 10, 13, 16, 19, and 22) and cortisol and melatonin levels were determined using the radioimmunoassay and enzyme immunoassay techniques, respectively. Results: The results showed that as the intensity of light increased at night, the plasma cortisol level increased, as well. Besides, no statistically significant difference was found between the plasma cortisol levels in natural light and 4500-lux light. On the other hand, a significant difference was observed between the plasma cortisol levels in natural light and 9000-lux light as well as 4500- and 9000-lux lights. The study findings also showed that as the intensity of light increased at night, the plasma melatonin level decreased. In addition, a statistically significant difference was found between the plasma melatonin levels in natural light and 4500-lux light. Nevertheless, no significant difference was observed between the plasma melatonin levels in the natural light and 9000-lux light as well as 4500- and 9000-lux lights. Conclusions: The present study aimed to investigate the subsequences of shift working in the security guards of Shiraz University of Medical Sciences and showed that occupational exposure to bright light could affect some biological markers, such as melatonin and cortisol secretion

Outline of changes in cortisol and melatonin circadian rhythms in the security guards of Shiraz University of Medical Sciences

Background: According to the literature, a large number of people working in industries and service providing personnel, such as firefighters, physicians, and nurses are shift workers. The spread of shift working in industrial societies and the incidence of the problems resulting from shift working have caused the researchers to conduct studies on this issue. The present study also aimed to investigate melatonin and cortisol circadian rhythms in the security guards of Shiraz University of Medical Sciences, Shiraz, Iran. Methods: The present study was conducted on 20 security guards of Shiraz University of Medical Sciences. In order to collect the study data, blood samples were taken from the study subjects in different times of the day (1, 4, 7, 10, 13, 16, 19, and 22) and cortisol and melatonin levels were determined using the radioimmunoassay and enzyme immunoassay techniques, respectively. Results: The results showed that as the intensity of light increased at night, the plasma cortisol level increased, as well. Besides, no statistically significant difference was found between the plasma cortisol levels in natural light and 4500-lux light. On the other hand, a significant difference was observed between the plasma cortisol levels in natural light and 9000-lux light as well as 4500- and 9000-lux lights. The study findings also showed that as the intensity of light increased at night, the plasma melatonin level decreased. In addition, a statistically significant difference was found between the plasma melatonin levels in natural light and 4500-lux light. Nevertheless, no significant difference was observed between the plasma melatonin levels in the natural light and 9000-lux light as well as 4500- and 9000-lux lights. Conclusions: The present study aimed to investigate the subsequences of shift working in the security guards of Shiraz University of Medical Sciences and showed that occupational exposure to bright light could affect some biological markers, such as melatonin and cortisol secretion

Assessment of Farnesyl Transferase Inhibitory Effect of Crocin in MCF-7 Cell Line

Introduction: Farnesyl transferase inhibitors (FTIs) are a new class of drugs which are under clinical trial examinations for cancer treatment. Saffron extracted components have been reported to be of pharmaceutical properties when are applied in vivo/ in vitro against variety of diseases including cancer. Crocin is one the main chemicals in saffron which is suggested to be of cytotoxic effects against cancer cell lines. However, the exact mechanism of function of crocin against cancer cell lines is still remained to be illustrated by more research. In the present study the effect of crocin in inhibition of lamin B farnesylation was examined. Methods and Results: Crocin was extracted from saffron and purified by column chromatography as described by bathaie et.al. MCF-7 was cultured on DMEM media containing 10% FBS. Using 96-well-plates, cells treated with an increasing concentration range of 10-5000 ug/ml of crocin. After 24h, MTT assay was carried out to determine the IC50. Cells were treated with crocin (IC50) for 24h to induce cell death, and expression of Lamin B, as well as pernylated/ unprenylated Lamin B was assessed by western blotting, using primary antibody against lamin B (Santacruz, USA) and secondary HRP-tagged anti-rabbit (Sigma, Germany). Our results indicated that 3500ug/ml of crocin induced cell death in half of cell population upon 24h. We also observed that treatment of MCF-7 cells with 3500ug/ml for 24h results in an obviously significant decrease in lamin B protein expression. Data from gel shift assay analysis also showed that crocin induces prenyl-transferase- inhibitory mechanism in cells which is seen as a two separated bands of lamin B (including prenylated and unprenylated forms) compared to single band pattern in control. Conclusions: In conclusion, our results proposed that crocin induces prenyl transferase inhibition in MCF-7 cell line of breast cancer and therefore, it could be suggested as a potent phyto-compound for research and developing FTIs

A literary analysis of post #MeToo anglophone children’s literature

The present research aims to explore #MeToo themes in Anglophone children's literature published in post-#MeToo era. The selected case studies, intended for children aged three to nine, include My Shadow Is Pink by Scott Stuart, Franny's Father Is a Feminist by Rhonda Leet, and What Are Little Girls Made of? by Jeanne Willis. Through a #MeToo lens and drawing on feminist theories of gender, these case studies were closely examined. The #MeToo themes emerged from this literary analysis include queer mirroring and gender performativity, gender norms related to household chores, emotions, and clothing; consent, (gendered) fear, and power relations. A literary analysis of the textual and visual elements of these case studies reveals that by attributing agency to children and empowering them to exercise choice and independence, they can develop political consciousness, assert their personhood, challenge and reshape societal scripts surrounding gender, and become the heroes of their own narratives. Far from seeing children as passive recipients of adult instructions, this project and the chosen case studies show that children can enact their own unique forms of personal and even political agency and consciousness. This research highlights the transformative potential of children's literature, both for children and adults, when viewed through a #MeToo lens

Development of Polymeric Porous Membrane for Mediator-Less Microbial Fuel Cells: An Electrochemical Study

In this work, gold nanoparticles (AuNPs) are embedded on the proton exchange membrane in a straightforward manner and are made highly stable. Nanoparticles provide high surface-to-volume ratio with excellent biocompatibility, using appropriate ligands, which allows for a biocompatible environment for bacterial functions. High conductivity, high surface area and catalytic properties of AuNPs make them excellent materials for MFCs. We employed layer-by-layer (LbL) self-assembly technique to prepare multilayered thin-films of polycation poly(allylamine hydrochloride) (PAH) and negatively functionalized AuNPs. The (PAH/AuNP) thin-films act as the catalyst layers and are to provide means for high porosity and high electrical conductive in the LbL thin-films when the polycation serve to assist LbL thin-film formation through ionic bonds. Scanning electron microscopy was used to investigate the morphology and nano/microstructure of the porous membrane catalyst. Samples consisting of different thickness thin-films were tested for their performance over five-day periods. Bioelectricity was generated using Shewanella oneidensis MR-1 cultivated on organic substrate with trypticase soy broth medium. Trypticase soy broth and ferricyanide were injected into the anode and cathode chambers as anolyte and catholyte respectively. Generated voltage and current were monitored and recorded using LabView though NI-DMM, over five-day periods

Sun protection factor, total phenol, flavonoid contents and antioxidant activity of medicinal plants from Iran

Purpose: To evaluate the correlation between sun protection factor (SPF) and the content of phenol and flavonoid and antioxidant activity. Methods: Different parts of 9 medicinal plants were extracted with methanol using three extraction methods (percolation, Soxhlet and ultrasonically assisted extraction) to obtain 42 crude extracts. Their phenol and flavonoid contents, and antioxidant activities were determined using Folin-Ciocalteu reagent, aluminum chloride method and DPPH radical-scavenging activity, respectively. The SPF values were determined and correlated with the phenol and flavonoid contents as well as antioxidant activities. Results: The phenol and flavonoid contents, and antioxidant activities ranged from 54.16-688.97mg GAE/g, 13.38-146.60 mg QE/g and 9.5-1472.4 µg/mL, respectively while the SPFs were between 0.067 and 0.841. The highest SPF was related to Cucumis melo L. ultrasonically assisted leaf extract (0.841) and Artemisia absinthium L., aerial parts extracted with percolation method (0.717). A significant correlation was found between SPF and phenolic (p= 0.003) and flavonoid contents (p= 0.023). Conclusion: This study showed a correlation between SPF and phenolic and flavonoid contents. Ultrasonically assisted extract of C. melo leaf has suitable SPF and can be used in sun screen formulations