Biogenic Synthesis and Cytotoxic Effects of Silver Nanoparticles Mediated by White Rot Fungi

Silver nanoparticles (AgNPs) were successfully synthesized using silver nitrate via the biological route using the culture filtrate of Ganoderma enigmaticum as well as Trametes ljubarskyi white rot fungi materials at room temperature. The proposed synthetic technique was applied for the first time for AgNPs preparation via the biological route through a low-cost pathway, which considered as an adequate direction of preparation compared to the commercial methods. This study reports the in vitro cytotoxic effect of biologically synthesized AgNPs in disposing of the human lung cancer cell line (A549) and human breast cancer cell (MCF-7) by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. In addition, the viability of the tested cell lines was tested after treatment for 24 h in the presence of the prepared nanoparticles. The obtained results indicated the reduced viability of cancer cell lines with improving concentrations of AgNPs (40-120 mug/mL) at 24 h. Furthermore, at 120 mug/mL concentration, the fungal nanoparticles showed substantial cytotoxic effects toward the treated cells. Consequently, the results designated that the biologically synthesized silver nanoparticles have effective behavior for treating A549 and MCF-7 cancer cells from the laboratory experiment approach; however, additional studies are required to validate these results in vivo models as anticancer agents depending on their cytotoxic activit

高性能ぺロブスカイト太陽電池に向けたナノ構造の最適化 [全文の要約]

Perovskite solar cells (PSCs) based on organometal halide light-absorbing materials have attracted enormous research interest for solar cell applications due to their many intriguing optical and electronic features, such as large absorption coefficient, large chargecarrier mobility, long carrier-recombination lifetime and unique defect physics. Since the first report on a solid-state PSC with a (power conversion efficiency) PCE of 9.7% in 2012, and a PCE of 22.1% was certified in 2016. To improve the net PCE value more, it is important to elucidate the essential factors influencing on the PCE. This thesis focused on several element technologies to enhance PCE and the external quantum efficiency (EQE) from the viewpoints of 1) the light-harvesting, and 2) the hole extraction material. These studies were performed in order to give a better understanding and insight into the nanoarchitectures optimization for high-performance PSCs. Although a lot of studies have been done related to PSCs, the EQE values are almost saturated especially in the longer wavelengths. Therefore, it is necessary to find a new way to improve the EQE at longer wavelengths for PSCs. Plasmonics is a highly promising due to its light-harvesting property. In this section, inverted planar PSCs with a p-i-n device configuration of indium-doped tin oxide (ITO)/NiO/CH3NH3PbI3/[6,6]-phenyl-C61-butanoic acid methyl ester (PCBM)/Ag with and without gold nanoislands (Au NIs) were prepared. The results demonstrated that the Au NIs increased the PCE to 5.1%, almost twice that of the samples without Au NIs. This result is due to the excitation of surface plasmons. Furthermore, we observed an enhancement of EQE at wavelengths shorter than the plasmon resonance. It is speculated that the plasmoelectric potential effect may contribute to the enhancement of EQE at the off-resonance region. A hole-extracting layer (HEL) is a key material which affects device performances of PSCs. CoOx is a promising HEL for inverted planar PSCs with a p-i-n device configuration of ITO/CoOx/CH3NH3PbI3/PCBM/Ag. The devices fabricated according to a simple solution procedure showed the best photovoltaic PCE 14.5%, which is significantly superior to those fabricated with traditional HEL such as PEDOT:PSS (12.2%), NiOx (10.2%) and CuOx (9.4%), under the same experimental conditions. Photoluminescence (PL) spectra and the corresponding PL lifetime of perovskite deposited on varied HEL films were measured to obtain the hole-extracting characteristics, for which the hole-extracting times consistent with the trend of their PCE. The reproducibility and endurance of those devices were examined to show the outstanding long-term stability of the devices made of metal oxide HEL, for which the CoOx device still had PCE ~12% for over 1000 h.この博士論文全文の閲覧方法については、以下のサイトをご参照ください。https://www.lib.hokudai.ac.jp/dissertations/copy-guides

Synthesis and Characterization of a New ZIF-67@MgAl2O4 Nanocomposite and Its Adsorption Behaviour

Fabricating suitable adsorbents with low-cost and high efficiency extraction for measurement of very small amounts of agricultural pesticides in food and water is playing a vital key role in personal and environmental health. Here, a new composite of zeolitic imidazolate framework-67@magnesium aluminate spinel (ZIF-67@MgAl2O4) has been fabricated by a simple method at room temperature with different weight ratios. Several techniques such as FE-SEM, BET, XRD, and TGA have been used to confirm the structural characterization of the obtained materials. The obtained ZIF-67@MgAl2O4 was utilized as an adsorbent in the solid phase microextraction technique to extract and preconcentrate the herbicide molinate (as an analyte) in aqueous solution. Corona discharge ionization-ion mobility spectrometry (CD-IMS) was applied for quantification of the analyte molecules. Extraction temperature, extraction time, stirring rate, and sample pH as the main parameters that affected the extraction proficiency were chosen and considered. Under optimal conditions, the linear dynamic range (LDR) of the various concentrations of the molinate and correlation coefficient were 10.0-100.0 mu g L-1 and 0.9961, respectively. The limit of quantification (LOQ) and method detection limit (MDL) were 10.0 mu g L-1 and 3.0 mu g L-1, respectively. The relative standard deviation (RSD) of the ZIF-67@MgAl2O4 for extracting the molinate molecules (molinate concentration; 50 mu g L-1) was calculated to be 4% and the enrichment factor (EF) was similar to 5.The authors of the article are delighted to manifest their gratitude Isfahan University of Technology for nancial support. Furthermore, AES is grateful for the National Research grants from MINECO, Spain, “Juan de la Cierva” [FJCI-2018-037717

Acceleration of Ammonium Phosphate Hydrolysis Using TiO2 Microspheres as a Catalyst for Hydrogen Production

Titania microspheres are considered an adequate material with low cost and easily attainable pathways, and can be utilized in photocatalytic H-2 production to solve the energy crisis. Spherical porous titanium dioxide materials, with nanostructure composition, were chemically synthesized from titanate nanotubes via a simple hydrothermal technique, then added as a catalyst to accelerate the route of ammonium phosphate hydrolysis for hydrogen production. The mechanism of sphere formation from titanate nanotubes is elucidated in detail through the current study. The prepared materials were applied as a photocatalyst to facilitate the separation and transfer of photoinduced electrons, while preventing the recombination of electron-hole pairs. Experimental results show that the obtained microspheres possess significantly enhanced photocatalytic hydrogen (H-2) production performance. The amount of photocatalytic hydrogen product using the microspheres is found to be similar to 2.5 fold greater than that of titanate nanotubes. Analytical techniques such as field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), simulated visible solar light and X-ray diffraction (XRD) were used for the evaluation and characterization of the developed products, as well as the elucidation of the route of hydrolysis in the hydrogen production process.Beni-Suef University through PSAS is appreciated by the authors for their efforts to follow up this study. Furthermore, AES is thankful for the National Research grants from MINECO "Juan de la Cierva" [FJCI-2018-037717

Investigation of the Biological Activity, Mechanical Properties and Wound Healing Application of a Novel Scaffold Based on Lignin–Agarose Hydrogel and Silk Fibroin Embedded Zinc Chromite Nanoparticles

Given the important aspects of wound healing approaches, in this work, an innovative biocompatible nanobiocomposite scaffold was designed and prepared based on cross-linked lignin-agarose hydrogel, extracted silk fibroin solution, and zinc chromite (ZnCr2O4) nanoparticles. Considering the cell viability technique, red blood cell hemolysis in addition to anti-biofilm assays, it was determined that after three days, the toxicity of the cross-linked lignin-agarose/SF/ZnCr2O4 nanobiocomposite was less than 13%. Moreover, the small hemolytic effect (1.67%) and high level of prevention in forming a P. aeruginosa biofilm with low OD value (0.18) showed signs of considerable hemocompatibility and antibacterial activity. Besides, according to an in vivo assay study, the wounds of mice treated with the cross-linked lignin-agarose/SF/ZnCr2O4 nanobiocomposite scaffold were almost completely healed in five days. Aside from these biological tests, the structural features were evaluated by FT-IR, EDX, FE-SEM, and TG analyses, as well as swelling ratio, rheological, and compressive mechanical study tests. Additionally, it was concluded that adding silk fibroin and ZnCr2O4 nanoparticles could enhance the mechanical tensile properties of cAll authors gratefully acknowledge the partial support from the Research Council of the Iran University of Science and Technology. Furthermore, A. E. S. is grateful for the National Research grants from MINECO, Spain, "Juan de la Cierva" [FJCI2018-037717]. Also, we thank the Ethics Research Committee and Biotechnology Research Center from Semnan University of Medical Science