A new approach to understand the time-dependent temperature increasing process of gold-silica core-shell nanoparticles injected into chicken tissues under near-infrared laser irradiation is proposed. Gold nanoshells strongly absorb near-infrared radiations and efficiently transform absorbed energy into heat. Temperature rise given by experiments and numerical calculations based on bioheat transfer are in good agreement. Our work improves the analysis of a recent study [Richardson et al., Nano Lett. 2009, 9, 1139 by including effects of the medium perfusion on temperature increase. The theoretical analysis can also be used to estimate the distribution of nanoparticles in experimental samples and provide a relative accuracy prediction for the temperature profile of new systems. This

The larvicidal activity of essential oils (EOs) extracted from Cymbopogon citratus, Cymbopogon winterianus, Eucalyptus citriodora, and Eucalyptus camaldulensis aromatic plants grown in Vietnam was evaluated on Aedes aegypti larvae. The EOs were hydro-distilled in a Clevenger-type apparatus. The EOs were analyzed by gas chromatography-mass spectrometry (GC-MS). The mortality rates obtained from the bioassays were used to calculate the lethal concentrations (LC 50 ) of the EOs by the probit analysis method. These essential oils exhibited toxicity to the larvae of Aedes aegypti. Results were obtained for Cymbopogon citratus (LC 50 = 120.6 ppm), Cymbopogon winterianus (LC 50 = 38.8 ppm), Eucalyptus citriodora (LC 50 = 104.4 ppm), and Eucalyptus camaldulensis (LC 50 = 33.7 ppm). The essential oils of Eucalyptus camaldulensis and Cymbopogon winterianus were found to be the most efficient, and their respective values of LC 50 were 33.7 ppm, 38.8 ppm. In conclusion, this research adds to the growing body of literature on natural larvicides from essential oils against Aedes aegypti mosquitoes.

In this article, the influence of the medium refractive index on optical properties of gold nanorods (GNRs) and their surface enhanced Raman spectroscopy application were studied. In particular, GNRs have been applied in biomedical sensors to detect diseases by monitoring the changes in the environment. In this study, the changes in optical properties of GNRs were investigated according to the medium refractive index changes in the cationic surfactant cetyltrimethylammonium bromide (CTAB) during synthesis processes as well as GNR dispersion in different medium refractive indices. For instance, in the solutions with different concentrations of CTAB, GNRs were coated by biomolecules [such as PEG, bovine serum albumin (BSA), and glutathione (GSH)], which have different refractive indices. The fundamental reason for the change in optical properties of GNRs is also elucidated. GNRs have been used to enhance surface Raman scattering to detect indigo molecules. The results showed that due to the surface plasmon resonance effect, the GNRs could strongly enhance the scattering signal of indigo dyes, with the lowest detectable concentration of up to 10−8 M and with an enhancement coefficient of over 2000 times.

The research has established a method to directly extract and determine free quercetin (aglycone form) from Flos Sophorae Immaturus methanol extract by using a simple HPLC method. Conducting experiment with system HPLC Agilent 1260 Infinity, reverse column ZORBAX SB-C18 (temperature 25oC), flow rate 0.5 ml/min, average pressure 30 and 35 bar, and diode array detector (DAD), we found that these parameters is suitbale: λmax = 370 nm, injection volume is 20 µl, analysis time 16 minutes, mobile phase (% volume) consists of methanol (15%), acetonitril (20%) and solvent C (65%, contains 1% acetic acid, methanol, acetonitril and H2O, 40%, 15% and 45% respectively. After using a combination of irocratic elution and standard addition, retention time of free quercetin in Flos Sophorae Immaturus methanol extract has found to be 8.84 ± 0,05 (min). Relative standard deviation (RSD) of retetion time, peak area and peak height have been less than 1%, this results have indicated that the proposed method has fullfilled the validation parameters such as selectivity/specitifity, precision/repeatability. This study provided useful information for screening activity of quercetin by using different methods.

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