Rhodium-embedded UV photodetectors based on localized surface plasmon resonance on AlN/GaN.

We report a remarkably enhanced responsivity of metal-semiconductor-metal photodetectors embedded with a large-scale periodicity and highly uniform rhodium nanoparticle array based on localized surface plasmon resonance. In this study, we used theoretical simulations of the absorption, scattering, and extinction behaviors, as well as the near electromagnetic field distributions to predict the plasmon resonance wavelength of quasi-triangular-shaped rhodium nanoparticles. More specifically, we successfully implemented a hexagonal close-packed structure with the individual quasi-triangular-shaped rhodium nanoparticle on the AlN/GaN structure by self-assembly nanosphere technology. The characterization results showed that the device embedded with rhodium nanoparticles had a reduced dark current of 7 × 10-14 A, and the maximum responsivity was shifted to a longer wavelength of approximately 310 nm compared to the device without rhodium nanoparticles. Moreover, at a wavelength of 324 nm, the enhancement ratio of the responsivity was as high as 56. Our study makes a significant contribution to the literature with a highly uniform, large-scale distributed rhodium nanoparticle array for enhancing the performance of AlGaN-based photodetectors in the UV region.

miR-150 is downregulated in osteosarcoma and suppresses cell proliferation, migration and invasion by targeting ROCK1.

[This retracts the article DOI: 10.3892/ol.2017.5709.].

High Efficiency Adsorption Removal of Arsenilic Acid and Arsenate(V) by Iron-Modified Corncob Biochar.

It is crucial that a highly effective adsorbent can be used to simultaneously remove the composite pollution including both inorganic and organic arsenic from wastewater. In this work, the iron modified corncob biochar (MCCB), prepared via the co-precipitation of ferric chloride hexahydrate (FeCl3⋅6H2O) with sodium hydroxide (NaOH) on corncob biochar, was studied for the high efficiency removal of arsenilic acid (ASA) and arsenate [As(V)] in wastewater. X-ray diffraction, scanning electron microscopy, and fourier transform infrared spectroscopy were carried out to characterize the MCCB. At pH of 4.0-5.0, initial concentration of 10 mg/L ASA and 1 mg/L As(V), adsorbent dose of 0.4 g/L, the maximum adsorption capacities of ASA and As(V) were 49.20 and 4.89 mg/g, respectively. The adsorption performance of MCCB for ASA and As(V) was fitted well to the pseudo-second-order kinetic model. Results from this study indicate the promise of MCCB as an efficient, low-cost and environmentally friendly adsorbent for composite arsenic pollution.

Mechanism of effect of endogenous/exogenous rice protein and its hydrolysates on rice starch digestibility.

The role of endogenous/exogenous rice protein and its hydrolysates in the enzymatic hydrolysis resistance of rice starch was investigated. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and Fourier transform infrared spectroscopy (FTIR) results showed that different types of rice endogenous proteins retarded the digestion of rice starch by the same way. Exogenous addition of protein hydrolysates was more effective than protein for impeding starch digestion. FTIR results indicated that rice protein hydrolysates were bound to starch granules through hydrogen bonds, and their interaction strengthened the ordered structure of the starch. Further, the intensity of the starch V- type peak was enhanced after the addition of protein hydrolysates, indicating that some peptides or free amino acids released by the protein formed complexes with the starch, thereby contributing to high slowly-digestible starch content. These findings provide a theoretical basis for the preparation of low glycemic index starch-based foods.

Green preparation and characterization of starch nanoparticles using a vacuum cold plasma process combined with ultrasonication treatment.

In this study, starch nanoparticles (SNPs) were fabricated via a facile and green method involving a vacuum low-temperature plasma process combined with rapid ultrasonication treatment using waxy corn starch (WCS) and potato starch (PS). Morphology, size, crystalline structure, thermal property, and stability analyses of the SNPs were systematically performed. The obtained SNPs exhibited good uniformity and almost perfect spherical and square shapes. The zeta potential and Fourier transform infrared spectroscopy results confirmed that the SNPs were covered with negative carboxyl groups (zeta potential ranging from -21.8 ±â€¯1.06 to -9.78 ±â€¯0.89 mV). The gelatinization enthalpy of SNPs from PS significantly decreased, changing from 16.63 ±â€¯0.91 to 9.81 ±â€¯0.19 J/g. However, the crystal patterns of SNPs from the WCS and PS after plasma and ultrasonic treatments did not change. The crystallinity of SNPs from PS decreased from 45.2% to 16.5%. This novel approach to preparing SNPs is low cost, simple and green. The developed SNPs could have great potential in the food, biomedical, and material industries.

Preparation of Bioactive Polysaccharide Nanoparticles with Enhanced Radical Scavenging Activity and Antimicrobial Activity.

Because of their biocompatibility and biodegradability in vivo, natural polysaccharides are effective nanocarriers for delivery of active ingredients or drugs. Moreover, bioactive polysaccharides, such as tea, Ganoderma lucidum, and Momordica charantia polysaccharides (TP, GLP, and MCP), have antibacterial, antioxidant, antitumor, and antiviral properties. In this study, tea, Ganoderma lucidum, and Momordica charantia polysaccharide nanoparticles (TP-NPs, GLP-NPs, and MCP-NPs) were prepared via the nanoprecipitation approach. When the ethanol to water ratio was 10:1, the diameter of the spherical polysaccharide nanoparticles was the smallest, and the mean particle size of the TP-NPs, GLP-NPs, and MCP-NPs was 99 ± 15, 95 ± 7, and 141 ± 9 nm, respectively. When exposed to heat, increased ionic strength and pH levels, the nanoparticles exhibited superior stability and higher activity than the corresponding polysaccharides. In physiological conditions (pH 7.4), the nanoparticles underwent different protein adsorption capacities in the following order: MCP-NPs> TP-NPs> GLP-NPs. Moreover, the 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, and superoxide anion radical scavenging rates of the nanoparticles were increased by 9-25% as compared to the corresponding polysaccharides. Compared to the bioactive polysaccharides, the nanoparticles enhanced antimicrobial efficacy markedly and exhibited long-acting antibacterial activity.

miR-150 is downregulated in osteosarcoma and suppresses cell proliferation, migration and invasion by targeting ROCK1.

Osteosarcoma (OS) is the most common form of bone malignancy in children and adolescents. A class of molecules known as microRNAs (miRNAs) have been routinely associated in the development and progression of OS. The present study was centered on the less well-known miRNA, miRNA (miR)-150, and its role in OS was investigated. The levels of miR-150 were examined in 40 tissue specimens from patients with OS and adjacent normal tissues using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. In addition the expression levels of miR-150 were examined in three OS cell lines and a normal osteoblast cell line. Cell proliferation, migration and invasion assays were performed to establish the correlation between miR-150 and metastasis. The potential targets of miR-150 were theoretically predicted and one high-scoring target, Rho-associated kinase 1 (ROCK1), was established to be a direct target using RT-qPCR and western blot analyses and Pearson's correlation analysis. The results indicated that miR-150 was downregulated in tissues from patients with OS and cell lines. Secondly, it was shown that the overexpression of miR-150 was inversely correlated with OS cell proliferation, migration and invasion. It was also shown that miR-150 negatively regulated the gene expression of ROCK1 in the OS cell lines. Finally, the interaction between miR-150 and ROCK1 was established and it was shown that miR-150 directly targeted ROCK1. In conclusion, miR-150 was found to be a tumor suppressor, and the suppression of miR-150 resulted in elevation in the levels of ROCK1. This interaction between miR-150 and ROCK1 may be key in the progression of OS. Furthermore, miR-150 or ROCK1 may be potential therapeutic targets for the treatment of OS.

Dependence of Raman Spectral Intensity on Crystal Size in Organic Nano Energetics.

Raman spectra for various nitramine energetic compounds were investigated as a function of crystal size at the nanoscale regime. In the case of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), there was a linear relationship between intensity of Raman spectra and crystal size. Notably, the Raman modes between 120 cm(-1) and 220 cm(-1) were especially affected, and at the smallest crystal size, were completely eliminated. The Raman spectral intensity of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), like that of CL-20's, depended linearly on crystal size. The Raman spectral intensity of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), however, was not observably changed by crystal size. A non-nitramine explosive compound, 2,4,6-triamino-1,3,5- trinitrobenzene (TATB), was also investigated. Its spectral intensity was also found to correlate linearly with crystal size, although substantially less so than that of HMX and CL-20. To explain the observed trends, it is hypothesized that disordered molecular arrangement, originating from the crystal surface, may be responsible. In particular, it appears that the thickness of the disordered surface layer is dependent on molecular characteristics, including size and conformational flexibility. Furthermore, as the mean crystal size decreases, the volume fraction of disordered molecules within a specimen increases, consequently, weakening the Raman intensity. These results could have practical benefit for allowing the facile monitoring of crystal size during manufacturing. Finally, these findings could lead to deep insights into the general structure of the surface of crystals.

Pyrolytic and kinetic characteristics of Platycodon grandiflorum peel and its cellulose extract.

The pyrolytic and kinetic characteristics of a biomass waste material, namely Platycodon grandiflorum A. DC (P. G.) peel and its cellulose extract were studied at heating rates of 10, 30 and 50 °C/min under a nitrogen flow atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by using the Popescu, FWO and KAS methods. The three stages appeared during pyrolysis include: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the P. G. peel and its cellulose extract were observed. Stage II of the P. G. peel and its cellulose extract could be described by the function Avrami-Erofeev [-ln(1-α)](3) and the function chemical reaction (1-α)(-0.5), respectively. The average activation energy of P. G. peel and its cellulose extract were 157 and 196 kJ/mol, respectively. Kinetic compensation effects of the pre-exponential factors and activation energy were also observed.

Soy-derived isoflavones inhibit HeLa cell growth by inducing apoptosis.

Isoflavones are among the major bioactive compounds found in a wide variety of plant-derived foods, especially in soybeans and soy-based foods. In this study, the effect of a soy-derived isoflavone mixture (designated as SI-I, containing 71% daidzein, 14.3% genistein and 14.7% glycitein) on HeLa cells and its mechanism were investigated. SI-I in concentration range 5-80 µg/ml significantly reduced the survival rate of HeLa cells by MTT assay, whereas showed no side effect on that of L929 cells. After HeLa cells were exposed to 10, 20 and 40 µg/ml SI-I for 4 days, typical apoptotic morphological changes, including nuclear fragmentation, cytoplasm shrinkage and decrease of cell volume, were observed by fluorescence microscope and CLSM, respectively. FCM analysis revealed that the percentages of early apoptotic cells with lost Δψm increased by 2.27, 2.74 and 4.05 folds respectively, compared with control. The results showed that SI-I inhibited HeLa cell growth through inducing apoptosis via the mitochondrial pathway and comparisons with reported data indicated that synergistic effect existed between the isoflavone species contained in SI-I. It is proposed that natural soy-derived isoflavones are potential candidates as chemotherapeutic agents against human cervical cancer.

RDX-based nanocomposite microparticles for significantly reduced shock sensitivity.

Cyclotrimethylenetrinitramine (RDX)-based nanocomposite microparticles were produced by a simple, yet novel spray drying method. The microparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and high performance liquid chromatography (HPLC), which shows that they consist of small RDX crystals (∼0.1-1 µm) uniformly and discretely dispersed in a binder. The microparticles were subsequently pressed to produce dense energetic materials which exhibited a markedly lower shock sensitivity. The low sensitivity was attributed to small crystal size as well as small void size (∼250 nm). The method developed in this work may be suitable for the preparation of a wide range of insensitive explosive compositions.