18 research outputs found

    Development of Food-Luring Baited Traps for Solenopsis invicta (Hymenoptera: Formicidae) Monitoring in the Field in Southern China

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    Solenopsis invicta Buren (Hymenoptera: Formicidae), a red imported fire ant that originated from South America, is a worldwide invasive pest. This study investigated the efficacy of the newly designed baited trap to detect red imported fire ants, Solenopsis invicta Buren, under field conditions in China. Among the five food lures tested for red imported fire ants, the ants preferred ham sausage and fish powder, followed by mixed powder (50% fish powder + 50% black soldier fly powder) and black soldier fly powder. These lures were compared to sugar water (control) to determine their efficacy in trapping red imported fire ants. Field data revealed that the ham sausage powder trap was more efficient than the fish powder trap based on its ability to trap more red imported fire ants under field conditions and ease of use. Thus, it was concluded that the baited traps are efficient for longterm red imported fire ants monitoring

    A machinable carbon aerogel composite with a low thermal conductivity and enhanced mechanical properties

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    Carbon aerogels are prepared via the sol–gel polymerisation of resorcinol with formaldehyde, followed by supercritical drying and carbonisation. The fabricated carbon aerogels have low densities in the range 0.028–0.196 g cm−3, ultra-low thermal conductivities in the range 0.0259–0.0707 W (m K)−1 and high specific surface areas (>520 m2 g−1). The carbon aerogel composites are reinforced with short carbon fibres by adding the carbon fibres to the resorcinol–formaldehyde solution to reduce their brittle nature and improve their machinability. The compressive strength of the composites containing 2 wt-% carbon fibres is 1.75 MPa, which is 56% higher than that of pure carbon aerogel. Both fracture toughness and compressive strength of these composites are improved. These composites also have good machinability, with the ability to maintain their shape after being machined with traditional steel tools. Furthermore, the composites with nanoporous structure exhibit ultra-low thermal conductivity up to 1400°C. © 2018, © 2018 Institute of Materials, Minerals and Mining. Published by Taylor & Francis on behalf of the Institute

    Effects of moderate static magnetic fields on the lipogenesis and lipolysis in different genders of Caenorhabditis elegans

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    With the rapid development of magnetic technology, the biological effects of moderate static magnetic fields (SMFs) have attracted increasing research interest due to their potential medical diagnosis and treatment application. The present study explored the effects of moderate SMFs on the lipid metabolism of Caenorhabditis elegans (C. elegans) in different genders including male, female, and hermaphrodite. We found that the fat content was significantly decreased by moderate SMFs in wild-type N2 worms, which was associated with their development stages. The diameters of lipid droplets in N2 worms, him-5 worms, and fog-2 worms were greatly decreased by 19.23%, 15.38%, and 23.07% at young adult stage under 0.5 T SMF, respectively. The mRNA levels of lipolysis related genes atgl-1 and nhr-76 were significantly up-regulated by SMF exposure, while the mRNA levels of the lipogenesis related genes fat-6, fat-7, and sbp-1 were down-regulated by SMF, whereas the concentration of β-oxidase was increased. There was a slight effect of SMF on the mRNA levels of β-oxidation related genes. Moreover, the insulin and serotonin pathway were regulated by SMF, instead of the TOR pathway. In wild-type worms, we found that their lifespan was prolonged by exposure to 0.5 T SMF. Our data suggested that moderate SMFs could significantly modify the lipogenesis and lipolysis process in C. elegans in a gender and development stage-dependent manner, which could provide a novel insight into understanding the function of moderate SMFs in living organisms

    Non-Fourier thermal shock fracture of solids with shallow semi-elliptical surface crack

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    In this study, a thick plate with a shallow semi-elliptical surface crack subjected to a transient thermal load was investigated based on the non-Fourier heat conduction law. Using a Laplace transform and its numerical inversion transform methods, the non-Fourier temperature fields and associated thermal stress formulas in the solid uncracking were obtained. Then, using the weight function and analogy methods, the thermal stress intensity factor formula at the crack tip was determined. The effects of the thermal shock time, crack depth, and crack shape on the thermal stress intensity factor and the crack growth behavior were explored numerically by comparing the Fourier model with a non-Fourier model. The results demonstrate that the non-Fourier model is much safer for studying the thermal shock cracking and crack growth behavior of solids under high-temperature applications

    H19 Promoter DNA Methylation is Lower Among Early Abortion Patients Undergoing IVF Embryo Transfer

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    Background: H19 is the first long noncoding RNA (lncRNA) found to be associated with gene imprinting. It is highly expressed in the embryonic stage and may have important regulatory effects on human embryonicdevelopment. We investigated the differences between the levels of H19 promoter DNA methylation in the chorionic villi of patients who experienced spontaneous abortion (SA) following in vitro fertilization embryo transfer (IVF-ET) and those of patients with a normal early pregnancy (NEP). We also analyzed the associated DNA methyltransferase (DNMT) activity.Methods: Chorionic villus tissue from patients with SA and NEP were collected. The DNA methylation levels of two CpG islands in the promoter region of the H19 gene in the two groups were detected by bisulfite sequencing, and the mRNA expression of DNMTs was analyzed by real-time polymerase chain reaction.Results: The sample size of each group was 32, and there were no significant differences in baseline data, including age, parity, and body mass index, between the two groups. Among the 7 CpG islands measured, the methylation rates of 3 CpG islands (CpG 1, 6, and 7) were significantly lower in the SA group than in the NEPgroup (P < 0.01). The methylation levels of the other 4 CpG islands were not significantly different between the two groups. There were no differences in the expression of DNMT1 between the two groups (P > 0.05), but DNMT3a and DNMT3b RNA levels were significantly lower in SA group than in the NEP group (P < 0.01).Conclusions: The lower H19 promoter DNA methylation levels found in the chorionic villi of patients with SA patients following IVF-ET may be explained by decreased expression of DNMT3a and DNMT3b

    Investigation of High-Temperature Normal Infrared Spectral Emissivity of ZrO2 Thermal Barrier Coating Artefacts by the Modified Integrated Blackbody Method

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    Zirconium oxide (ZrO2) is widely used as the thermal barrier coating in turbines and engines. Accurate emissivity measurement of ZrO2 coating at high temperatures, especially above 1000 °C, plays a vital role in thermal modelling and radiation thermometry. However, it is an extremely challenging enterprise, and very few high temperature emissivity results with rigorously estimated uncertainties have been published to date. The key issue for accurately measuring the high temperature emissivity is maintaining a hot surface without reflection from the hot environment, and avoiding passive or active oxidation of material, which will modify the emissivity. In this paper, a novel modified integrated blackbody method is reported to measure the high temperature normal spectral emissivity of ZrO2 coating in the temperature range 1000 °C to 1200 °C and spectral range 8 μm to 14 μm. The results and the associated uncertainty of the measurement were estimated and a relative standard uncertainty better than 7% (k = 2) is achieved
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