RESUMEN
A proposed nanosensor based on hybrid nanoshells consisting of a core of metal nanoparticles and a coating of molecules is simulated by plasmon-exciton coupling in semi classical approach. We study the interaction of electromagnetic radiation with multilevel atoms in a way that takes into account both the spatial and the temporal dependence of the local fields. Our approach has a wide range of applications, from the description of pulse propagation in two-level media to the elaborate simulation of optoelectronic devices, including sensors. We have numerically solved the corresponding system of coupled Maxwell-Liouville equations using finite difference time domain (FDTD) method for different geometries. Plasmon-exciton hybrid nanoshells with different geometries are designed and simulated, which shows more sensitive to environment refractive index (RI) than nanosensor based on localized surface plasmon. The effects of nanoshell geometries, sizes, and quantum emitter parameters on the sensitivity of nanosensors to changes in the RI of the environment were investigated. It was found that the cone-like nanoshell with a silver core and quantum emitter shell had the highest sensitivity. The tapered shape of the cone like nanoshell leads to a higher density of plasmonic excitations at the tapered end of the nanoshell. Under specific conditions, two sharp, deep LSPR peaks were evident in the scattering data. These distinguishing features are valuable as signatures in nanosensors requiring fast, noninvasive response.
Asunto(s)
Nanopartículas del Metal , Nanocáscaras , Resonancia por Plasmón de Superficie/métodos , Oro , Simulación por ComputadorRESUMEN
This study investigated the in vitro anthelmintic activity of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles (NPs) against Marshallagia marshalli. The in vitro study was based on an egg hatch assay, adult and larvae motility inhibition assays, DNA damage, intensity protein profile along with several oxidative/nitrosative stress biomarkers including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), protein carbonylation (PCO), malondialdehyde (MDA), total antioxidant status (TAS) and nitric oxide (NO) content. Different concentrations of CuO-NPs and ZnO-NPs (1, 4, 8, 12 and 16 ppm) were used to assess anthelmintic effects on three stages of M. marshalli life cycle - that is, eggs, larvae and adult parasites for 24 h. The results indicated that CuO-NPs and ZnO-NPs played a significant role as anthelminthics, and the effect was dependent on time and concentration. The concentrations of 12 and 16 ppm of CuO-NPs and 16 ppm of ZnO-NPs resulted in the induction of oxidative/nitrosative stress (decreased SOD, GSH-Px and CAT, and increased MDA, PCO and NO), increased DNA damage, inhibition of adult and larval motility, egg hatch and low intensity of protein bands following sodium dodecyl sulphate-polyacrylamide gel electrophoresis, compared to control. It was concluded that CuO-NPs and ZnO-NPs could be utilized as novel and potential agents for the control and treatment of M. marshalli infection, and they have the pharmacological potential to be studied in vivo for further utilization in treating parasitic infections.
Asunto(s)
Nanopartículas , Nematodos , Óxido de Zinc , Animales , Biomarcadores , Cobre/toxicidad , Daño del ADN , Estrés Nitrosativo , Estrés Oxidativo , Óxido de Zinc/farmacologíaRESUMEN
OBJECTIVE: Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with potentially fatal systemic effects on man. We aimed to determine the presence of CCHF virus among collected ticks from domestic livestock from October 2012 to September 2013. METHODS: A total of 1245 hard and soft ticks were collected from naturally infested ruminants in Marvdasht County, Fars Province, south of Iran. Nine tick species and one unidentified species in four disparate genera were detected. A total of 200 ticks were randomly selected and analysed by reverse transcription-polymerase chain reaction (RT-PCR) for the presence of CCHF virus genome. RESULTS: The viral genome was detected in 4.5% (9 samples) of the studied tick population. The infected ticks belonged to the species of Hyalomma marginatum' Hyalomma anatolicum and Rhipicephalus sanguineus. The viruses detected in these three tick species were clustered in the same lineage as Matin and SR3 strains in Pakistan and some other Iranian strains. These results indicate that the ticks were wildly infected with a genetically closely related CCHF virus in the region. CONCLUSION: Regular controls and monitoring of livestock to reduce the dispersion of ticks and providing information to those involved in high-risk occupations are urgently required.