Search

Excited-state electron and energy transfer from singlet excited rubrene (Ru) to benzoquinone (BQ) and tetra-(4-aminophenyl) porphyrin (TAPP) were investigated by steady-state absorption and emission, time-resolved transient absorption, and femtosecond (fs)–nanosecond (ns) fluorescence spectroscopy. The low reduction potential of BQ provides the high probability of electron transfer from the excited Ru to BQ. Steady-state and time-resolved results confirm such an excited electron transfer scenario. On the other hand, strong spectral overlap between the emission of Ru and absorption of TAPP suggests that energy transfer is a possible deactivation pathway of the Ru excited state. [ABSTRACT FROM AUTHOR]

Despite impressive power conversion efficiencies (PCEs) reported for lab-scale perovskite solar cells (PSCs), obtaining large-area devices with similar performance remains challenging. Fundamentally, this can largely be attributed to a polarity mismatch between the perovskite-precursor solution and the underlying hydrophobic contact materials, resulting in perovskite films of insufficient quality for scaled devices. Specifically, for p-i-n devices, the commonly used DMF/DMSO co-solvent has a significant polarity mismatch with its underlying hole-transporting layer, PTAA. Here, the role of MAPbI 3 •solvent adduct interaction with the PTAA surface towards the formation of micro- and nano-scale pinholes is elucidated in detail. Replacing DMSO with NMP in the co-solvent system changes the binding energy profoundly, enabling uniform and dense films over large areas. The PCE of DMF/NMP ink-based devices drops slightly with increasing active device area, from 21.5% (0.1 cm2) to 19.8% (6.8 cm2), in comparison with conventional DMF/DMSO ink. This work opens a pathway towards the scalability of solution-processed perovskite optoelectronic devices. Commercial photovoltaic technologies follow an empirical inverse scaling law, where the absolute power conversion efficiency (PCE) values drop by ~0.8% when the device area increases by an order of magnitude. Perovskite solar cells (PSCs) have yet to reach this mark; in current literature their PSCs exhibit a ~3.2% (n-i-p structure) and ~2.0% (p-i-n structure) drop in absolute PCE as the device area increases by an order of magnitude. In this work, we explore the underlying reasons for such scaling losses, especially for the p-i-n configuration, and have successfully reduced this scaling loss to ~0.9%. With a comprehensive understanding of the underlying mechanisms, high-quality PSCs with a PCE of 20.3% for 2 cm2 devices and 19.8% for 6.8 cm2 mini-modules were obtained. ga1 • The interaction between hydrophilic perovskite ink and hydrophobic PTAA surface is studied in detail. • Origins of micro and nano-scale pinholes in MAPbI 3 films over PTAA substrates and possibilities to avoid them are provided. • Reproducibility and scalability of perovskite mini-modules exhibiting 19.8% PCE for 6.8 cm2 is achieved. • Using fundamental insights, the scalability losses in PSCs fabricated on a hydrophobic surface are minimized. • Only ~0.9% loss in absolute PCE per order of magnitude change in the active area is achieved. [ABSTRACT FROM AUTHOR]

Herein, a green-solvent-processible and open-air-printable self-assembly strategy is demonstrated to close the lab-to-fab gap towards efficient, stable, cheap, eco-friendly, and scalable organic photovoltaic. [Display omitted] The ultimate goal of organic solar cells (OSCs) is to deliver cheap, stable, efficient, scalable, and eco-friendly solar-to-power products contributing to the global carbon neutral. However, simultaneously balancing these five critical factors of OSCs toward commercialization is extremely challenging. Herein, a green-solvent-processable and open-air-printable self-assembly strategy is demonstrated to synchronously simplify the device architecture, improve the power conversion efficiency (PCE) and enhance the shelf, thermal as well as light illumination stability of OSCs. The cathode interlayer (CIL)-free self-assembled OSCs exhibit the PCE of 15.5%, higher than that of traditional inverted OSCs of 13.0%, which is among the top values for both CIL-free self-assembled OSCs and open-air blade-coated bulk-heterojunction OSCs. The remarkable enhancements are mainly ascribed to the finely self-assembly, subtly controlled donor/acceptor aggregation rate, and delicately manipulated vertical morphology. Besides, this strategy enables 13.2% efficiency on device area of 0.98 cm2, implying its potential for scalability. These findings demonstrate that this strategy can close the lab-to-fab gap of OSCs toward commercialized cheap, stable, efficient, scalable, and eco-friendly OSCs. [ABSTRACT FROM AUTHOR]

Abstract: Oxidative stress may be regarded as an imbalance between free radical production and opposing antioxidant defenses. Free radical oxidative stress is implicated in rat cerebral ischemia and naturaceutical antioxidants are dietary supplements that have been reported to have neuroprotective activity. Many studies have reported dietary sesame oil (SO) as an effective antioxidant. In the present study the neuroprotective effect of dietary SO was evaluated against middle cerebral artery occlusion (MCAO)-induced cerebral ischemia injury in rats. Rats were fed on diet (20% SO) for 15 days. The middle cerebral artery of adult male Wistar rat was occluded for 2 h and reperfused for 22 h. The antioxidant properties of brain were measured as levels of reduced glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxide (GPx), glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD) and thiobarbituric acid reactive substance (TBARS). A decrease in the activity of all the enzymatic and non-enzymatic antioxidants was observed along with an increase in lipid peroxidation (LPO) in MCAO group. The neurobehavioral activity of rats was also observed by using videopath analyzer. Dietary SO improved the antioxidant status in MCAO+SO group when compared with MCAO group. The results of neurobehavioral activity also support our biochemical data. The results obtained suggest protective effect of SO against cerebral ischemia in rat brain through their antioxidant properties. [Copyright &y& Elsevier]

Bartonella bacilliformis a gram-negative facultative aerobe responsible for the Carrion's disease widely distributed in Ecuador, Peru, and Colombia with a high mortality rate when no specific treatment is received. B bacilliformis is transmitted by Sand fly (Lutzomyia verrucarum) to healthy individuals. Immunoinformatic and subtractive proteomics approaches were employed in this study to prioritize the best candidates for vaccine designing. These approaches resulted in five vaccine candidates, flagellar biosynthetic protein (Uniprot ID: A1UTU1), heme exporter protein C (UniProt ID: A1UU82), Cytochrome c-type biogenesis protein (Uniprot ID: A1URZ7), Hemin ABC transporter (Uniprot ID: A1US20) and Phosphatidate cytidylyltransferase (Uniprot ID: A1USE3). The mentioned proteins are antigenic and essential for pathogen survival. A range of immune-informatics tools was applied for the prediction of B and T cell epitopes for the vaccine candidate proteins. In-silico vaccine was constructed using carefully evaluated epitopes and consequently modeled for docking with human Toll-like receptor 4. TLR-4 agonist 50S ribosomal protein L7/L12 (UniproKB ID; P9WHE3) was linked to the vaccine as an adjuvant to boost immune response towards the vaccine. For stability evaluation of the vaccine-TLR-4 docked complex, MD simulations were performed. The final vaccine was back-translated and cloned in Eschericia coli to attain the maximal expression of the vaccine protein. The maximal expression was ensured, and the CAI score of 0.96 was reported. The current vaccine requires future experimental validation to confirm its effectiveness. The vaccine developed will be helpful to protect against B bacilliformis associated infections. • Bartonella bacilliformis a gram-negative, Peru, and Colombia with a high mortality rate. • Immunoinformatics and subtractive proteomics approaches were employed in this study to prioritize the best candidates for vaccine designing. • In-silico vaccine was constructed using carefully evaluated epitopes and consequently modeled for docking with human Toll-like receptor 4. • For stability evaluation of the vaccine-TLR-4 docked complex, MD simulations were performed. • The maximal expression was ensured, and the CAI score of 0.96 was reported. [ABSTRACT FROM AUTHOR]