3,355 research outputs found
Colorimetric and fluorogenic anion sensors of 2 '-(p-nitrophenyl)-imidazol[4 ',5 '-f]-1, 10-phenanthroline[5,6-f] and its complex of Ru(bipy)(2)(2+)
2'-(p-nitrophenyl)-imidazol[4',5'-f]-1,10-phenanthroline[5,6-f] (1) and its [image omitted] complex (2) were synthesised and studied for the anion sensing by UV-vis, fluorescence and H-1 NMR titration experiments. Compounds 1 and 2 exhibited obviously different changes between reactions with AcO-, F-, H2PO4- and with other halogens, i.e. Cl-, Br-, I-, in any of the UV-vis, fluorescence and H-1 NMR titration spectra in DMSO experiments. With an 89nm red shift, 1 was convenient to be employed to detect anions with the naked eye. Complexed with the electron withdrawing metal ion, 2 had the stronger interaction with anions to be detected than 1 had
IFN-gamma is associated with risk of Schistosoma japonicum infection in China.
Before the start of the schistosomiasis transmission season, 129 villagers resident on a Schistosoma japonicum-endemic island in Poyang Lake, Jiangxi Province, 64 of whom were stool-positive for S. japonicum eggs by the Kato method and 65 negative, were treated with praziquantel. Forty-five days later the 93 subjects who presented for follow-up were all stool-negative. Blood samples were collected from all 93 individuals. S. japonicum soluble worm antigen (SWAP) and soluble egg antigen (SEA) stimulated IL-4, IL-5 and IFN-gamma production in whole-blood cultures were measured by ELISA. All the subjects were interviewed nine times during the subsequent transmission season to estimate the intensity of their contact with potentially infective snail habitats, and the subjects were all re-screened for S. japonicum by the Kato method at the end of the transmission season. Fourteen subjects were found to be infected at that time. There was some indication that the risk of infection might be associated with gender (with females being at higher risk) and with the intensity of water contact, and there was evidence that levels of SEA-induced IFN-gamma production were associated with reduced risk of infection
Facile Synthesis of High Quality Graphene Nanoribbons
Graphene nanoribbons have attracted attention for their novel electronic and
spin transport properties1-6, and because nanoribbons less than 10 nm wide have
a band gap that can be used to make field effect transistors. However,
producing nanoribbons of very high quality, or in high volumes, remains a
challenge. Here, we show that pristine few-layer nanoribbons can be produced by
unzipping mildly gas-phase oxidized multiwalled carbon nanotube using
mechanical sonication in an organic solvent. The nanoribbons exhibit very high
quality, with smooth edges (as seen by high-resolution transmission electron
microscopy), low ratios of disorder to graphitic Raman bands, and the highest
electrical conductance and mobility reported to date (up to 5e2/h and 1500
cm2/Vs for ribbons 10-20 nm in width). Further, at low temperature, the
nanoribbons exhibit phase coherent transport and Fabry-Perot interference,
suggesting minimal defects and edge roughness. The yield of nanoribbons was ~2%
of the starting raw nanotube soot material, which was significantly higher than
previous methods capable of producing high quality narrow nanoribbons1. The
relatively high yield synthesis of pristine graphene nanoribbons will make
these materials easily accessible for a wide range of fundamental and practical
applications.Comment: Nature Nanotechnology in pres
Natural products triptolide, celastrol, and withaferin A inhibit the chaperone activity of peroxiredoxin I
published_or_final_versio
Graphene nanoribbons with zigzag and armchair edges prepared by scanning tunneling microscope lithography on gold substrates
The properties of graphene nanoribbons are dependent on both the nanoribbon width and the crystallographic orientation of the edges. Scanning tunneling microscope lithography is a method which is able to create graphene nanoribbons with well defined edge orientation, having a width of a few nanometers. However, it has only been demonstrated on the top layer of graphite. In order to allow practical applications of this powerful lithography technique, it needs to be implemented on single layer graphene. We demonstrate the preparation of graphene nanoribbons with well defined crystallographic orientation on top of gold substrates. Our transfer and lithography approach brings one step closer the preparation of well defined graphene nanoribbons on arbitrary substrates for nanoelectronic applications
Niches and Interspecific Competitive Relationships of the Parasitoids, Microplitis prodeniae and Campoletis chlorldeae, of the Oriental Leafworm Moth, Spodoptera litura, in Tobacco
Both Microplitis prodeniae Rao and Chandry (Hymenoptera: Bracondidae) and Campoletis chlorideae Uchida (Hymenoptera: Ichnumonidae) are major parasitoids of Spodoptera litura (Fabricious) (Lepidoptera: Noctuidae) in tobacco, Nicotiana tabacum L. (Solanales: Solanaceae) at Nanxiong, Guangdong Province, South China. The niches and interspecific competition relationships of the two species were studied. The results show that the competition between the two species for spatial and food resources was very intense, and C. chlorideae was always dominant when the two species compete for spatial and food resources in different periods. Thus C. chlorideae may drive M. prodeniae away when they occupy the same spatial or food resource. The adaptability of C. chlorideae to the environment in the tobacco fields may be greater than that of M. prodeniae, so C. chlorideae can maintain a higher population compared to that of M. prodeniae
Atomic Force Microscopy of height fluctuations of fibroblast cells
We investigated the nanometer scale height fluctuations of 3T3 fibroblast
cells with the atomic force microscope (AFM) under physiological conditions.
Correlation between these fluctuations and lateral cellular motility can be
observed. Fluctuations measured on leading edges appear to be predominantly
related to actin polymerization-depolymerization processes. We found fast (5
Hz) pulsatory behavior with 1--2 nm amplitude on a cell with low motility
showing emphasized structure of stress fibres. Myosin driven contractions of
stress fibres are thought to induce this pulsation.Comment: 6 pages, 5 figures, 1 tabl
An intuitionistic fuzzy programming method for group decision making with interval-valued fuzzy preference relations
Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography
A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)
- …