Far-field Super-resolution Imaging with Dual-Dye-Doped Nanoparticles

We propose to achieve super-resolution in far-field imaging by use of dual-dye-doped nanoparticles. The nanoparticles with a diameter of a few nanometers are co-doped with two types of dye molecules, namely, Cy3 and Cy5, at a controllable ratio. Due to the short distances between the dye molecules confined in the nanoparticles, Forster resonant energy transfer can occur between the Cy3 and Cy5 molecules with high efficiency. Therefore, the Cy5 molecules can quench the fluorescence emission from the Cy3 molecules in the outer region of focal spot of the excitation beam, thereby enhancing the resolution of imaging.Comment: 13 pages, 3 figure

Genome architecture changes and major gene variations of Andrias davidianus ranavirus (ADRV)

Ranaviruses are emerging pathogens that have led to global impact and public concern. As a rarely endangered species and the largest amphibian in the world, the Chinese giant salamander, Andrias davidianus, has recently undergone outbreaks of epidemic diseases with high mortality. In this study, we isolated and identified a novel ranavirus from the Chinese giant salamanders that exhibited systemic hemorrhage and swelling syndrome with high death rate in China during May 2011 to August 2012. The isolate, designated Andrias davidianus ranavirus (ADRV), not only could induce cytopathic effects in different fish cell lines and yield high viral titers, but also caused severely hemorrhagic lesions and resulted in 100% mortality in experimental infections of salamanders. The complete genome of ADRV was sequenced and compared with other sequenced amphibian ranaviruses. Gene content and phylogenetic analyses revealed that ADRV should belong to an amphibian subgroup in genus Ranavirus, and is more closely related to frog ranaviruses than to other salamander ranaviruses. Homologous gene comparisons show that ADRV contains 99%, 97%, 94%, 93% and 85% homologues in RGV, FV3, CMTV, TFV and ATV genomes respectively. In addition, several variable major genes, such as duplicate US22 family-like genes, viral eukaryotic translation initiation factor 2 alpha gene and novel 75L gene with both motifs of nuclear localization signal (NLS) and nuclear export signal (NES), were predicted to contribute to pathogen virulence and host susceptibility. These findings confirm the etiologic role of ADRV in epidemic diseases of Chinese giant salamanders, and broaden our understanding of evolutionary emergence of ranaviruses

Using Rare Earth Elements to Constrain Particulate Organic Carbon Flux in the East China Sea

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing model, and 30-80% using the REEs mixing model, respectively. These results suggest that REEs may be better proxies for sediment resuspension than OC in high turbidity marginal seas because REEs do not appear to undergo degradation during particle sinking as compared to organic carbon. Our results suggest that REEs can be used as tracers to provide quantitative estimates of POC fluxes in marginal sea

Knock-down of glutaminase 2 expression decreases glutathione, NADH, and sensitizes cervical cancer to ionizing radiation

AbstractPhosphate-activated mitochondrial glutaminase (GLS2) is suggested to be linked with elevated glutamine metabolism. It plays an important role in catalyzing the hydrolysis of glutamine to glutamate. The present study was to investigate the potent effect of GLS2 on radioresistance of cervical carcinoma. GLS2 was examined in 144 cases of human cervical cancer specimens (58 radioresistant specimens, 86 radiosensitive specimens) and 15 adjacent normal cervical specimens with immunohistochemistry. HeLa cells were treated with a cumulative dose of 50Gy X-rays, over 6months, yielding the resistant sub-line HeLaR. The expressions of GLS2 were measured by Western blot. Radioresistance was tested by colony survival assay. Apoptosis was determined by flow cytometry. The levels of glutathione (GSH), reactive oxygen species (ROS), NAD+/NADH ratio and NADP+/NADPH ratio were detected by quantization assay kit. Xenografts were used to confirm the effect of GLS2 on radioresistance in vivo. The expressions of GLS2 were significantly enhanced in tumor tissues of radioresistant patients compared with that in radiosensitive patients. In vitro, the radioresistant cell line HeLaR exhibited significantly increased GLS2 levels than its parental cell line HeLa. GLS2 silenced radioresistant cell HeLaR shows substantially enhanced radiosensitivity with lower colony survival and higher apoptosis in response to radiation. In vivo, xenografts with GLS2 silenced HeLaR were more sensitive to radiation. At the molecular level, knock-down of GLS2 increased the intracellular ROS levels of HeLaR exposed to irradiation by decreasing the productions of antioxidant GSH, NADH and NADPH. GLS2 may have an important role in radioresistance in cervical cancer patients

Comparative Studies between the Regional Economic Growth Levels Based on the Three-Stage Weight Dynamic Comprehensive Evaluation

Part 5: Modelling and SimulationInternational audienceThis paper proposes a dynamic comprehensive evaluation method based on three times weight. Firstly, this paper determines the index weight based on the twice stage difference driving features. Then it introduces the relative balance coefficient to calculate the comprehensive evaluation value. This method has the following characteristics: 1) The comprehensive evaluation result is totally based on the information provided by the evaluating indicator system, without the influence from subjective factors; 2) The results have direct comparability among different evaluation systems at each time; 3) Motivation or punishment are the characteristics of this method. This approach has been applied to an empirical study of the regional economic growth level during the years of 2001 and 2011. Finally this paper makes related suggestions to the economic development of eight domestic economic regions

Late Quaternary terrigenous sedimentation in the Western Arctic Ocean as exemplified by a sedimentary record from the Alpha Ridge

Terrigenous components in sediment core B84A from the Alpha Ridge, Western Arctic Ocean, have been investigated to reconstruct Mid to Late Quaternary variations in sedimentation, provenance, and related climate changes. The core stratigraphy, evaluated by a combination of variations in Mn content, color cycles, foraminiferal abundance, and lithological correlation, extends back to estimated Marine Isotope Stage 12. Twelve Ice Rafted Detritus (IRD, >250 ¹m) events were identified and interpreted to mostly occur during deglaciation. The Canadian Arctic, which was covered by ice sheets during glacial periods, is suggested to be the major source region. The IRD events likely indicate the collapses of ice sheets, possibly in response to abrupt climate changes. Grain size analysis of B84A indicates sedimentologically sensitive components in core B84A in the 4{9 ¹m and 19{53 ¹m silt subfractions, which are inferred to be mainly transported by currents and sea ice, respectively. Down core variability of these two fractions may indicate changes in ice drift and current strength. In accordance with previous studies in the central Arctic Ocean, the average sedimentation rate in core B84A is about 0.4 cm*ka(-1). Compared with the relatively high sedimentation rates on the margins, sedimentation in the central Arctic Ocean is limited by sea ice cover and the correspondingly low bioproductivity, as well as the long distance from source regions of terrigenous sediment

Discovery of Stable and Selective Antibody Mimetics from Combinatorial Libraries of Polyvalent, Loop-Functionalized Peptoid Nanosheets.

The ability of antibodies to bind a wide variety of analytes with high specificity and high affinity makes them ideal candidates for therapeutic and diagnostic applications. However, the poor stability and high production cost of antibodies have prompted exploration of a variety of synthetic materials capable of specific molecular recognition. Unfortunately, it remains a fundamental challenge to create a chemically diverse population of protein-like, folded synthetic nanostructures with defined molecular conformations in water. Here we report the synthesis and screening of combinatorial libraries of sequence-defined peptoid polymers engineered to fold into ordered, supramolecular nanosheets displaying a high spatial density of diverse, conformationally constrained peptoid loops on their surface. These polyvalent, loop-functionalized nanosheets were screened using a homogeneous Förster resonance energy transfer (FRET) assay for binding to a variety of protein targets. Peptoid sequences were identified that bound to the heptameric protein, anthrax protective antigen, with high avidity and selectivity. These nanosheets were shown to be resistant to proteolytic degradation, and the binding was shown to be dependent on the loop display density. This work demonstrates that key aspects of antibody structure and function-the creation of multivalent, combinatorial chemical diversity within a well-defined folded structure-can be realized with completely synthetic materials. This approach enables the rapid discovery of biomimetic affinity reagents that combine the durability of synthetic materials with the specificity of biomolecular materials

Regional Geological Survey of Hanggai, Xianxia and Chuancun, Zhejiang Province in China

This Open Access book introduces readers to the regional geology of Hanggai, Xianxia and Chuancun, the area between China's northern Zhejiang Province and southern Anhui Province and explores the strata, magmatic rocks and tectonic structures in 1:50,000 scale geological maps. Based on studies of multiple stratigraphic divisions, the standard stratigraphic section of the upper Ordovician Hirnantian in the lower Yangtze region is established, revealing for the first time numerous “Burgess Shale-type” sponge fossils in Hirnantian strata and identifying 10 grapholite fossil belts and various fossil categories, including chitin, trilobites, gastropods, brachiopods, and cephalopods. Moreover, the book identifies for the first time Late Ordovician volcanic events in northern Zhejiang province. The work represents a major contribution to research on Paleozoic strata in the Lower Yangtze region, and sheds new light on understanding the Hirnantian glacial event and biological extinction event in South China by providing a high-precision time scale. In addition, the book opens an important avenue for future research on sponge evolution after the Cambrian life explosion. As such, it offers a unique and valuable asset for researchers and graduate students alike

Changing sources and burial of organic carbon in the Chukchi Sea sediments with retreating sea ice over recent centuries

Decreasing sea ice extent in summer caused by climate change is affecting the carbon cycle of the Arctic Ocean. In this study, surface sediments across the western Arctic Ocean are investigated to characterize sources of sedimentary organic carbon (OC). Bulk organic parameters (total organic carbon, total nitrogen, &delta;13Corg and &delta;15N) combined with molecular organic biomarkers (e.g., sterols and highly branched isoprenoids (HBIs)) are applied to distinguish between sympagic, pelagic, and terrestrial OC. Furthermore, downcore profiles of these parameters were also generated from the Chukchi Sea R1 core (74&deg; N) to evaluate changes in the relative contribution of these three components of sedimentary OC over the last 200 years with decreasing sea ice. Our data evidence that from 1820s to 1930s, prevailing high and variable sea ice cover inhibited in situ primary production resulting in prominent land-derived material stored in sediments. From 1930s to 1980s, with the gradual decline of sea ice, primary production increased progressively. The ratio of sympagic and pelagic OC began to rise to account for a larger portion of sedimentary OC. Since 1980s, accelerated sea ice loss led to enhanced primary production, stabilizing over the last decades due to freshwater induced surface ocean stratification in summer.</p