53 research outputs found

    Mesoporous Highā€Surfaceā€Area Copperā€“Tin Mixedā€Oxide Nanorods: Remarkable for Carbon Monoxide Oxidation

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    Mesoporous, highā€surfaceā€area Cuā€“Sn mixedā€oxide nanorods were fabricated for the first time by nanocasting with the use of mesoporous KITā€6 silica as the hard template. The Cuā€“Sn nanorods are significantly more active than 1ā€‰% Pd/SnO2 for the oxidation of CO and possesses longā€term durability and potent water resistance; they thus have the potential to replace noble metal catalysts for emissionā€control processes.In rod we trust: Mesoporous, highā€surfaceā€area Cuā€“Sn nanorods are successfully fabricated for the first time by nanocasting with the use of KITā€6 silica as the hard template; these nanomaterials are significantly more active than 1ā€‰% Pd/SnO2 for the oxidation of CO, and furthermore, they have the potential to replace noble metal catalysts for emission control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/1/cctc201600221.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/2/cctc201600221-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/3/cctc201600221_am.pd

    The Progress of CDAS

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    The Chinese Data Acquisition System (CDAS) based on FPGA techniques has been developed in China for the purpose of replacing the traditional analog baseband converter. CDAS is a high speed data acquisition and processing system with 1024 Msps sample rate for 512M bandwidth input and up to 16 channels (both USB and LSB) output with VSI interface compatible. The instrument is a flexible environment which can be updated easily. In this paper, the construction, the performance, the experiment results, and the future plans of CDAS will be reported

    Circulating Fibroblast Growth Factor 21 Levels Are Closely Associated with Hepatic Fat Content: A Cross-Sectional Study

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    BACKGROUND AND AIMS: Fibroblasts growth factor 21 (FGF21), a liver-secreted endocrine factor involved in regulating glucose and lipid metabolism, has been shown to be elevated in patients with non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the quantitative correlation between serum FGF21 level and hepatic fat content. METHODS: A total of 138 subjects (72 male and 66 female) aged from 18 to 65 years with abnormal glucose metabolism and B-ultrasonography diagnosed fatty liver were enrolled in the study. Serum FGF21 levels were determined by an in-house chemiluminescence immunoassay and hepatic fat contents were measured by proton magnetic resonance spectroscopy. RESULTS: Serum FGF21 increased progressively with the increase of hepatic fat content, but when hepatic fat content increased to the fourth quartile, FGF21 tended to decline. Serum FGF21 concentrations were positively correlated with hepatic fat content especially in subjects with mild/moderate hepatic steatosis (rā€Š=ā€Š0.276, pā€Š=ā€Š0.009). Within the range of hepatic steatosis from the first to third quartile, FGF21 was superior to any other traditional clinical markers including ALT to reflect hepatic fat content. When the patients with severe hepatic steatosis (the fourth quartile) were included, the quantitative correlation between FGF21 and hepatic fat content was weakened. CONCLUSIONS: Serum FGF21 was a potential biomarker to reflect the hepatic fat content in patients with mild or moderate NAFLD. In severe NAFLD patients, FGF21 concentration might decrease due to liver inflammation or injury

    Analyses of the yeast Rad51 recombinase A265V mutant reveal different in vivo roles of Swi2-like factors

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    The Saccharomyces cerevisiae Swi2-like factors Rad54 and Rdh54 play multifaceted roles in homologous recombination via their DNA translocase activity. Aside from promoting Rad51-mediated DNA strand invasion of a partner chromatid, Rad54 and Rdh54 can remove Rad51 from duplex DNA for intracellular recycling. Although the in vitro properties of the two proteins are similar, differences between the phenotypes of the null allele mutants suggest that they play different roles in vivo. Through the isolation of a novel RAD51 allele encoding a protein with reduced affinity for DNA, we provide evidence that Rad54 and Rdh54 have different in vivo interactions with Rad51. The mutant Rad51 forms a complex on duplex DNA that is more susceptible to dissociation by Rdh54. This Rad51 variant distinguishes the in vivo functions of Rad54 and Rdh54, leading to the conclusion that two translocases remove Rad51 from different substrates in vivo. Additionally, we show that a third Swi2-like factor, Uls1, contributes toward Rad51 clearance from chromatin in the absence of Rad54 and Rdh54, and define a hierarchy of action of the Swi2-like translocases for chromosome damage repair

    Screening of Bioactive Ingredients in Ligusticum Chuanxiong Hort for Protection against Myocardial Ischemia

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    Background/Aims: To study the spectrum-effect relationship and effective components of Ligusticum Chuanxiong Hort. (LCH) on the protection of canine myocardial ischemia. Methods: Fingerprint spectrum of LCH extracts was developed using high performance liquid chromatography (HPLC), and a canine model of acute myocardial ischemia was established by ligating the coronary artery. Bivariate correlation analysis and multivariate regression analysis were used to correlate the pharmacodynamics of LCH extract and its common peaks in HPLC. Results: The bioactive components of LCH were ligustrazine, ferulic acid, cnidilide and ligustilide. Ligustrazine and ferulic acid could significantly reduce serum lactic acid in canine model of acute myocardial ischemia, while ligustilide could significantly reduce the elevation of serum free fatty acid. Conclusions: The spectrum-effect relationship study shows that the effective components of LCH are ligustrazine, ferulic acid, cnidilide and ligustilide, which have protective effect on myocardial ischemia

    Effects of Meteorological Factors on Waterbird Functional Diversity and Community Composition in Liaohe Estuary, China

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    Functional trait diversity represents ecological differences among species, and the structure of waterbird communities is an important aspect of biodiversity. To understand the effect of meteorological changes on the waterbird functional diversity and provide suggestions for management and conservation, we selected a study area (726 km2) in Liaohe Estuary, located in northeast China. We explored the trends of the waterbird functional diversity changes in response to meteorological factors using fourth corner analysis. Our study demonstrated that temperature was a key factor that impacted waterbird functional diversity in spring, while precipitation had a greater impact in autumn. The population size of goose and duck was positively associated with temperature and negatively with precipitation, while that of the waders (Charadriiformes) showed opposite association trends. Herbivores and species nesting on the bare ground exhibited responses to meteorological factors similar to those of geese and ducks, while benthivores and waterbirds nesting under grass/shrubs exhibited trends similar to those of waterbirds. Waterbirds with smaller bodies, shorter feathers, and lower reproductive rates preferred higher temperatures and less precipitation than other waterbirds. In addition, we observed seasonal variations in waterbird functional diversity. In spring, we should pay attention to waders, herbivores, and waterbirds nesting on the bare ground when the temperature is low. In autumn, waders, benthivores, and omnivores need more attention under extreme precipitation. As the global climate warms in this study area, waterbird functional diversity is expected to decline, and community composition would become simpler, with overlapping niches. Biodiversity management should involve protecting intertidal habitats, supporting benthic macrofaunal communities, preparing bare breeding fields for waterbirds favoring high temperatures to meet their requirements for population increase, and preventing the population decline of geese and ducks, herbivores, and species nesting under grass/shrubs. The findings of our study can aid in developing accurate guidelines for waterbird biodiversity management and conservation

    Ku-Band Sea Surface Radar Backscatter at Low Incidence Angles under Extreme Wind Conditions

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    This paper reports Ku-band normalized radar cross section (NRCS) at low incidence angles ranging from 0Ā° to 18Ā° and in the wind speed range from 6 to 70 m/s. The precipitation radar onboard the tropical rainfall measuring mission and Jason-1 and 2 have provided 152 hurricanes observations between 2008 and 2013 that were collocated with stepped-frequency microwave radiometer measurements. It is found that the NRCS decreases with increasing incidence angle. The decrease is more dramatic in the 40ā€“70 m/s range of wind speeds than in the 6ā€“20 m/s range, indicating that the NRCS is very sensitive to low incidence angles under extreme wind conditions and insensitive to the extreme wind speed. Consequently, the sea surface appears relatively ā€œsmoothā€ to Ku-band electromagnetic microwaves. This phenomenon validates the observed drag coefficient reduction under extreme wind conditions, from a remote sensing viewpoint. Using the NRCS dependence on incidence angle under extreme wind conditions, we also present an empirical linear relationship between NRCS and incidence angles, which may assist future-satellites missions operating at small incidence angles to measure sea surface wind and wave field

    Synthesis and Comparative Study of Polyether-<i>b</i>-polybutadiene-<i>b</i>-polyether Triblock Copolymers for Use as Polyurethanes

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    In this paper, the effects of HTPBs with different main-chain microstructures on their triblock copolymers and polyurethane properties were investigated. Three polyether-modified HTPB triblock copolymers were successfully synthesized via a cationic ring-opening copolymerization reaction using three HTPBs with different microstructures prepared via three different polymerization methods as the macromolecular chain transfer agents and tetrahydrofuran (THF) and propylene oxide (PO) as the copolymerization monomers. Finally, the corresponding polyurethane elastomers were prepared using the three triblock copolymers as soft segments and toluene diisocyanate (TDI) as hard segments. The results of an analysis of the triblock copolymers showed that the triblock copolymers had lower viscosity and glass transition temperature (Tg) values as the HTPB 1,2 structure content decreased, although the effect on the thermal decomposition temperature was not significant. An analysis of the polyurethane elastomers revealed that as the content of the 1,2 structure in HTPB increased, its corresponding polyurethane elastomers showed a gradual increase in breaking strength and a gradual decrease in elongation at break. In addition, PU-1 had stronger crystallization properties compared to PU-2 and PU-3. However, the differences in the microstructures of the HTPBs did not seem to have much effect on the surface properties of the polyurethane elastomers

    A non-uniform quadtree map building method including dead-end semantics extraction

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    To reduce the complexity of large-scene high-resolution maps while using the dead-end information distributed in the unmanned vehicle driving environment, we propose a novel non-uniform quadtree map-building method including dead-end semantic information extraction. By utilizing quadtree data structures, submaps and a positive-order tree depth organization approach, our proposed map can adapt to the large-scale high-resolution requirement and expand more easily to larger environments. To verify the practicality of our proposed map, we have successfully implemented map matching and path planning in real environments. Additionally, we effectively extract the dead-end semantic information that widely distributes in the environment, which can help unmanned vehicles avoid collisions and improve the search efficiency of the planning procedure. We evaluate our method with KITTI datasets, CARLA Simulator, and our self-collected real-world datasets. The experimental results show that our proposed method significantly reduces the complexity of large-scale high-resolution maps, effectively extracts dead-end semantic information, and has good practicality in real environments. The implementation of our method is released here: https://github.com/biter0088/Non-uniform-quadtree-map
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