Highly Sensitive and Selectively Deposited Gold Nanoparticles on the Reduced Graphene Oxide for the SERS Application

School of Molecular Sciences(Chemistry)Surface enhanced Raman scattering (SERS) is the enhancement of the Raman signal by several orders of magnitude via the electromagnetic enhancement or the chemical enhancement of metal nanostructures. In addition, graphene also has a Raman enhancement by its novel property that is referred to graphene enhanced Raman scattering (GERS). In this, we combined electromagnetic enhancement of the gold nanoparticles which has a selectivity onto the sp2 carbon surface and the GERS effect of patterned reduced graphene oxide (prGO) for the highly sensitive and stable SERS platform. Our SERS substrate can be applied to the diagnostic SERS device and also enables the selective and dense attachment of metal nanoparticles on the graphene surface.ope

??-Fe2O3 on patterned fluorine doped tin oxide for efficient photoelectrochemical water splitting

Patterned FTO was fabricated via a facile method as an efficient current collector in a photoelectrochemical water splitting system. The photocurrent density of ??-Fe2O3 on patterned FTO exhibited a 1.7 times increase relative to ??-Fe2O3 on FTO due to the light scattering and rapid transfer of excited electrons. ??? The Royal Society of Chemistry 2015close1

Dendrimer-Capped Gold Nanoparticles for Highly Reliable and Robust Surface Enhanced Raman Scattering

Dendrimer-stabilized gold nanoparticles (Au-Den) were prepared by a facile solution based method for a highly reliable and robust surface enhanced Raman scattering (SERS) substrate. Au-Den was selectively attached on the surface of reduced graphene oxide (rGO) by noncovalent interactions between the Au capping dendrimer and the graphene surface. Au-Den/rGO exhibits the outstandingly stable and highly magnified Raman signal with an enhancement factor (EF) of 3.9 X 10(7) that enables detection of R6G dyes with concentration as low as 10 nM, retaining 95% of the Raman signal intensity after 1 year. The remarkable stability and enhancement originated not only from a simple combination of the electromagnetic and chemical mechanism of SERS but also from intensified packing density of stable Au Den on the graphene substrate due to the firm binding between the dendrimer capped metal nanoparticles and the graphene substrate. This method is not limited to the gold nanoparticles and G4 dendrimer used herein, but also can be applied to other dendrimers and metal nanoparticles, which makes the material platform suggested here superior to other SERS substrates.clos

10-DEBC Hydrochloride as a Promising New Agent against Infection of <i>Mycobacterium abscessus</i>

Mycobacterium abscessus (M. abscessus) causes chronic pulmonary infections. Its resistance to current antimicrobial drugs makes it the most difficult non-tuberculous mycobacteria (NTM) to treat with a treatment success rate of 45.6%. Therefore, there is a need for new therapeutic agents against M. abscessus. We identified 10-DEBC hydrochloride (10-DEBC), a selective AKT inhibitor that exhibits inhibitory activity against M. abscessus. To evaluate the potential of 10-DEBC as a treatment for lung disease caused by M. abscessus, we measured its effectiveness in vitro. We established the intracellular activity of 10-DEBC against M. abscessus in human macrophages and human embryonic cell-derived macrophages (iMACs). 10-DEBC significantly inhibited the growth of wild-type M. abscessus and clinical isolates and clarithromycin (CLR)-resistant M. abscessus strains. 10-DEBC’s drug efficacy did not have cytotoxicity in the infected macrophages. In addition, 10-DEBC operates under anaerobic conditions without replication as well as in the presence of biofilms. The alternative caseum binding assay is a unique tool for evaluating drug efficacy against slow and nonreplicating bacilli in their native caseum media. In the surrogate caseum, the mean undiluted fraction unbound (fu) for 10-DEBC is 5.696. The results of an in vitro study on the activity of M. abscessus suggest that 10-DEBC is a potential new drug for treating M. abscessus infections

Evaluation of fouling in nanofiltration for desalination using a resistance-in-series model and optical coherence tomography

Resistance-in-series models have been applied to investigate fouling behavior. However, it is difficult to model the influence of morphology on fouling behavior because resistance is indirectly calculated from the water flux and transmembrane pressure. In this study, optical coherence tomography (OCT) was applied to evaluate the resistance of the fouling layer based on fouling morphology. Sodium alginate, humic add, and bovine serum albumin (BSA) with high salts concentrations (conductivity: 23 mS/cm) were used as model foulants. At the same total fouling resistance, BSA showed the highest cake layer thickness (BSA (114.5 mu m) &gt; humic add (53.5 mu m) &gt; sodium alginate (20.0 mu m)). However, a different order was found for the cake layer resistance (BSA &gt; sodium alginate &gt; humic add). This indicates that fouling thickness is not correlated with cake layer resistance. According to the Carman-Kozeny equation, fouling layer porosity decreased in the following order: humic add (0.30) &gt; BSA (0.21) &gt; sodium alginate (0.20). In addition, we provided a specific value that was calculated using the ratio between the fouling thickness and cake layer resistance. The results show that alginic acid induced a stronger cake layer resistance, despite its thin fouling layer, whereas BSA showed a relatively low potential for inducing cake layer resistance. The results obtained in this study could be used for estimating and predicting fouling behavior. (C) 2018 Elsevier B.V. All rights reserve

Plasma-free atomic layer deposition of Ru thin films using H-2 molecules as a nonoxidizing reactant

The ruthenium (Ru) thin films were grown by atomic layer deposition (ALD) using a sequential supply of dicarbonyl-bis(5-methyl-2,4-hexanediketonato) Ru(II) (C16H22O6Ru) and H-2 as a reactant at a substrate temperature of 250 degrees C. Deposition was possible using H-2 molecules without a plasma by increasing the chamber pressure to above 10 Torr. Specifically, high-quality Ru films with a low resistivity of similar to 40 mu Omega cm and few amount of oxygen (similar to 1.2 at. %) were obtained under a chamber pressure of 300 Torr though the oxygen was contained in the precursor. Under the optimized conditions, self-limited film growth with regard to the precursor and reactant pulsing times was confirmed under elevated chamber pressures. The ALD-Ru process proposed in this study showed one of the highest growth rates of 0.12 nm/cycle on a thermally grown SiO2 substrate, as well as a very low number of incubation cycles (approximately 12 cycles). Cross-sectional view transmission electron microscopy showed that no interfacial oxide had formed during the deposition of the ALD-Ru films on a W surface using H-2 molecules, whereas similar to 7 nm thick interfacial oxide was formed when O-2 molecules were used as a reactant. The step coverage of the ALD-Ru film onto very small-sized trenches (aspect ratio: similar to 4.5 and the top opening size of 25 nm) and holes (aspect ratio: similar to 40 and top opening size of 40 nm) was excellent (similar to 100%). (C) 2016 American Vacuum Society

Evaluating the effects of organic matter bioavailability on nanofiltration membrane using real-time monitoring

We studied the influence of bioavailability of organic matter on membrane fouling layer development by comparing the filtration performance of two feed waters (wetland water and graywater). Dissolved organic carbon (DOC) concentration, size exclusion chromatography (SEC), and fluorescence excitation-emission matrix (FEEM) were used to characterize the bioavailability of organic matter in these water samples during the nanofiltration process. The wetland sample contained a high proportion of humic acid-and fulvic acid-like matter with low bioavailability, whereas the graywater sample comprised substantial amounts of aromatic proteins and microbial byproduct-like matter with high bioavailability. In addition, the molecular size distribution revealed that the wetland sample contained a large portion of recalcitrant organic matter, whereas the graywater sample contained easily bioavailable organic matter. After the filtration experiment, the DOC of the wetland sample decreased to 4.8 mgC/L, whereas the graywater sample resulted in a lower DOC concentration of 3.4 mgC/L. Optical coherence tomography (OCT) illustrated real-time variations in the fouling layer morphology, providing both 2D and 3D images. In addition, confocal laser scanning microscopy (CLSM) quantified the bacterial volume in the fouling layer. The wetland sample yielded a bacterial volume of 11.8 mu m(3)/mu m(2) from a total fouling volume of 103 mu m(3)/mu m(2), whereas the graywater sample yielded a bacterial volume of 53.2 mu m(3)/mu m(2) from a total fouling layer volume of 134 mu m(3)/mu m(2). Fitting of the two-phase Monod model to the fouling layer growth on the membrane resulted in lower-yield coefficients (i.e., the volumes produced per unit amount of substrate, Yxs) of 7.46 and 27.95 mu m(3)/mu m(2) in wetland water and higher-yield coefficients of 13.17 and 47.53 mu m(3)/mu m(2) in the graywater at first and second phase, respectively. This study addresses the quantitative evaluation of the organic matter bioavailability in terms of membrane fouling using OCT images and a two-phase Monod model

Wound healing induced by new synthetic peptide, A7-1, in C57BL/6 mouse model

Abstract The effects of the novel synthetic peptide, A7-1, on wound healing and skin grafts were evaluated in a C57BL/6 mouse model. Two 15-mm wide circular skin excisions were made on the backs of mice and to each excision, 100 µM A7-1 or normal saline was applied daily. The treatments were applied and sutured for skin graft analysis. Digital photos were acquired on days 4, 7, 11, and 14 and fluorescein angiography was conducted. Wound sizes were verified using stereoscopic microscopy. Histological analysis was performed via hematoxylin and eosin staining and Masson’s trichrome staining. Western blotting was performed using vascular endothelial growth factor. Using a stereoscopic microscope, significantly faster wound healing (17.3%) and skin graft healing (16.5%) were observed in the A7-1 treatment group in comparison to that of the control. The angiogenesis was significantly faster in fluorescein angiography examination in wound healing (11%) and skin grafts (15%). However, the average completion of epithelization (overall time for wound healing), did not show any significant differences. In comparison to the control, the new protein, A7-1, led to significantly faster wound healing in the initial angiogenesis

Atomic Layer Deposition of Ru Thin Films Using a New Beta-Diketonate Ru Precursor and NH3 Plasma as a Reactant

Ruthenium (Ru) thin films were grown on thermally-grown SiO2 substrates by plasma enhanced atomic layer deposition (PEALD) using a sequential supply of a new betadiketonate Ru metal-organic precursor, dicarbonyl-bis(5-methyl-2,4-hexanediketonato) Ru(II) (C16H22O6Ru) with a high vapor pressure and NH3 plasma as a reactant at the substrate temperature ranging from 175 and 310 degrees C. A self-limited film growth was confirmed at the deposition temperature of 225 degrees C and the growth rate was 0.063 nm/cycle on the SiO2 substrate with very short number of incubation cycles (approximately 10 cycles). The resistivity of PEALD-Ru films was dependent on the microstructural features characterized by grain size and crystallinity, which could be controlled by varying the deposition temperature. Ru film with the resistivity of similar to 20 mu Omega-cm and high density of 11.5 g/cm(3) was obtained at the deposition temperature as low as 225 degrees C. It formed polycrystalline structure with hexagonal-close-packed phase that was confirmed by X-ray diffractometry and transmission electronic microscopy analysis. Step coverage of PEALD-Ru film deposited with the optimum condition was good (similar to 75%) at the very small-sized trench (aspect ratio: similar to 4.5 and the top opening size of 25 nm)