Tuning the plasmonic properties of silver nanopatterns fabricated by shadow nanosphere lithography

Regular silver (Ag) nanopatterns, from disconnected nanotriangles to well coupled triangular clusters of nanoparticles, were prepared by shadow nanosphere lithography at different incident angles θ from 0 degrees to 20 degrees with continuous azimuthal rotation. The resulting nanopatterns were consistent with predictions by numerical calculations and Monte Carlo simulations of adatoms with high diffusivity. The visible localized surface plasmon resonance of these nanopatterns was tuned by θ systematically due to the change in size, shape, and arrangement of Ag nanopatterns. These resonances were consistent with finite-difference time-domain simulations using realistic nanopatterns based upon scanning electron micrographs. Such a simple fabrication strategy can be used to optimize surface enhanced Raman scattering substrate fabrication, as well as other plasmonics based applications

Hydrogenation of Mg film and Mg nanoblade array on Ti coated Si substrates

The hydrogenation of Mg film and Mg nanoblade array fabricated on Ti coated Si substrates has been studied and compared. The nanoblades start to absorb hydrogen at a temperature between 250 and 300 degrees C, which is much lower than 350 degrees C for Mg film. However, the saturated total hydrogen uptake in nanoblades is less than half of that in the film, resulting from MgO formation by air exposure. The nanoblade morphology with large surface area and small hydrogen diffusion length, and the catalytic effect of Ti layer, are two main reasons for the nanoblade hydrogenation behavior

Tissue and ontogenic expression profiles of FATP1 and FATP4 genes in goose

Fatty acid transport proteins (FATPs) are a family of proteins involved in fatty acid uptake and activation. The tissues and ontogenic expression profiles of the critical genes participating in fatty acid metabolism have little been systematically investigated in goose. To gain insight into the gene-regulation processes in goose fatty   acid metabolism, we detected the expression profiles of FATP1 and FATP4 transcripts in goose tissues using  the quantitative real-time PCR method in two goose breeds: Zhejiang white goose and Landes goose. The   results show that FATP1 and FATP4 genes were ubiquitously expressed in all seven studied geese tissues. Both genes exhibited tissue-specific expression pattern in mRNA level with the highest expression level in leg   muscle and the lowest in abdominal fat. The liver and heart were also two important tissues for both of genes expression. The growth points at 35 and 56 days were important points for both of genes expression. In   addition, for the two breeds, both genes showed Zhejiang white goose had higher expression than Landes  goose. It can be speculated that the expression of FATP1 and FATP4 genes may have breed-specific. The   results could serve as a primary reference for the expression profile of goose fatty acid metabolism.Key words: Expression pattern, FATP1, FATP4, Landes goose, Zhejiang white goose

Antimicrobial activity of spherical silver nanoparticles prepared using a biocompatible macromolecular capping agent: evidence for induction of a greatly prolonged bacterial lag phase

<p>Abstract</p> <p>Background</p> <p>We have evaluated the antimicrobial properties of Ag-based nanoparticles (<it>Np</it>s) using two solid phase bioassays and found that 10-20 μL of 0.3-3 μM keratin-stabilized <it>Np</it>s (depending on the starting bacterial concentration = <it>C</it>_I) completely inhibited the growth of an equivalent volume of <it>ca</it>. 10³to 10⁴colony forming units per mL (CFU mL^-1) <it>Staphylococcus aureus</it>, <it>Salmonella </it>Typhimurium, or <it>Escherichia coli </it>O157:H7 on solid surfaces. Even after one week at 37°C on solid media, no growth was observed. At lower <it>Np </it>concentrations (= [<it>Np</it>]s), visible colonies were observed but they eventually ceased growing.</p> <p>Results</p> <p>To further study the physiology of this growth inhibition, we repeated these experiments in liquid phase by observing microbial growth via optical density at 590 nm (OD) at 37°C in the presence of a [<it>Np</it>] = 0 to 10^-6M. To extract various growth parameters we fit all OD[t] data to a common sigmoidal function which provides measures of the beginning and final OD values, a first-order rate constant (<it>k</it>), as well as the time to calculated 1/2-maximal OD (<it>t</it>_m) which is a function of <it>C</it>_I, <it>k</it>, as well as the microbiological lag time (<it>T</it>).</p> <p>Performing such experiments using a 96-well microtitre plate reader, we found that growth <it>always </it>occurred in solution but <it>t</it>_mvaried between 7 (controls; <it>C</it>_I= 8 × 10³CFU mL^-1) and > 20 hrs using either the citrate-([<it>Np</it>] ~ 3 × 10^-7M) or keratin-based ([<it>Np</it>] ~ 10^-6M) <it>Np</it>s and observed that {∂<it>t</it>_m/∂ [<it>Np</it>]}_citrate~ 5 × 10⁷and {∂<it>t</it>_m/∂ [<it>Np</it>]}_keratin~ 10⁷hr·L mol^-1. We also found that there was little effect of <it>Np</it>s on <it>S. aureus </it>growth rates which varied only between <it>k </it>= 1.0 and 1.2 hr^-1(1.1 ± 0.075 hr^-1). To test the idea that the <it>Np</it>s were changing the initial concentration (<it>C</it>_I) of bacteria (<it>i.e</it>., cell death), we performed probabilistic calculations assuming that the perturbations in <it>t</it>_mwere due to <it>C</it>_Ialone. We found that such large perturbations in <it>t</it>_mcould only come about at a <it>C</it>_Iwhere the probability of any growth at all was small. This result indicates that much of the <it>Np</it>-induced change in <it>t</it>_mwas due to a greatly increased <it>T </it>(<it>e.g</it>., from <it>ca</it>. 1 to 15-20 hrs). For the solid phase assays we hypothesize that the bacteria eventually became non-culturable since they were inhibited from undergoing further cell division (<it>T </it>> many days).</p> <p>Conclusion</p> <p>We propose that the difference between the solid and liquid system relates to the obvious difference in the exposure, or residence, time of the <it>Np</it>s with respect to the bacterial cell membrane inasmuch as when small, <it>Np</it>-inhibited colonies were selected and streaked on fresh (<it>i.e</it>., no <it>Np</it>s present) media, growth proceeded normally: <it>e.g</it>., a small, growth-inhibited colony resulted in a plateful of typical <it>S. aureus </it>colonies when streaked on fresh, solid media.</p

Discovery of Xestophanopsis gen. n. from China and taxonomic revision of two species misplaced in Ceroptres Hartig, 1840 (Hymenoptera, Cynipoidea: Cynipidae)

In the present paper, we describe Xestophanopsis Pujade-Villar &Wang gen. n. to the tribe Diastrophini based on Ceroptres distinctusWang, Liu & Chen, 2012 and transfer Ceroptres distinctusWang, Liu&Chen, 2012 to Periclistus Foerster, 1869 as Periclistus setosus (Wang, Liu & Chen, 2012) comb. n. In addition, we report the first record of Periclistus capillatus Kovalev, 1968 from China, along with the first report and description of themale. Finally, we provide a taxonomic key to all Eastern Palaearctic species of the genus Periclistus

Release of cholesterol-rich particles from the macrophage plasma membrane during movement of filopodia and lamellipodia.

Cultured mouse peritoneal macrophages release large numbers of ~30-nm cholesterol-rich particles. Here, we show that those particles represent fragments of the plasma membrane that are pulled away and left behind during the projection and retraction of filopodia and lamellipodia. Consistent with this finding, the particles are enriched in proteins found in focal adhesions, which attach macrophages to the substrate. The release of particles is abolished by blocking cell movement (either by depolymerizing actin with latrunculin A or by inhibiting myosin II with blebbistatin). Confocal microscopy and NanoSIMS imaging studies revealed that the plasma membrane-derived particles are enriched in 'accessible cholesterol' (a mobile pool of cholesterol detectable with the modified cytolysin ALO-D4) but not in sphingolipid-sequestered cholesterol [a pool detectable with ostreolysin A (OlyA)]. The discovery that macrophages release cholesterol-rich particles during cellular locomotion is likely relevant to cholesterol efflux and could contribute to extracellular cholesterol deposition in atherosclerotic plaques

Diverse responses of hydrodynamics, nutrients and algal biomass to water diversion in a eutrophic shallow lake

Water diversion has been increasingly applied to accelerate lake water exchange and alleviate urgent water crisis. However, effects of water diversion on water exchange and water quality for eutrophic lakes remain controversial. In this study, a three-dimensional hydrodynamic-water quality-sediment diagenesis model has been developed to assess effects of water diversion on hydrodynamics and water quality in eutrophic shallow Lake Wanghu. Results suggested that water diversion could dramatically promote water exchange and reduce residence time in most lake regions but its influence on water quality was diverse. A water transferring flow rate of 20–30 m3/s could reduce water age to 40–58 days during regular water diversion operation, whereas a high transferring flow rate of 100 m3/s was the best for emergency operation in late spring before the wet season. Moreover, nutrients and Chlorophyll-a exhibited notable spatial heterogeneity in improvement efficiency. Nutrients level in the donating system was a prerequisite to the relationship among water transport time scales, nutrients, and algal biomass in this eutrophic lake. During a clean water diversion, nutrients and algal biomass were positively associated with water age. However, when the donating system contained high level of nutrients, accumulated nutrients in the lake may still trigger algal bloom after a temporary relief due to flushing effect. Therefore, these water diversion strategies could be applied to guide a sustainable management of eutrophic Lake Wanghu in terms of transferring flow rate, wind fields, water quality in the donating system, transferring operation, and water diversion route.acceptedVersionPeer reviewe

Biomechanical analysis of the Maxillary Sinus Floor Membrane During internal Sinus Floor Elevation With Implants at Different angles of the Maxillary Sinus angles

OBJECTIVE: This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure. METHODS: 3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared. RESULTS: When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa. CONCLUSION: The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height