An experimental study on monitoring of marine sediment transport by using a 3D sediment trap

The observation and analysis of sediment transport in oceans is an important means for the protection of the marine environment, resource development, construction engineering, and element cycling. However, traditional methods of observing sediment transport are either limited by the range of the instruments used or their own observational attributes, such that they cannot be used to accurately detect and analyze the process of transport of marine sediment. A 3D sediment trap has been proposed to compensate for the shortcomings of the various monitoring tools in our team, but no mature method for the analytical inversion of the data obtained from this device has been developed to date. In this paper, we developed analytical methods to invert sediment transport processes using corrected capture efficiency, sample inversion, and transport flux analysis. Through an annular flume test, we measured the turbidity, pressure, and particle size of the water stream and substituted them into the proposed analytical equations, thus verifying the applicability of the analytical methods. We used the slice experiment of the time series of the sediment samples, to determine the validity of the sample inversion, and establish the relationship between the particle size and concentration of the captured samples. We performed restoration tests on the process of sediment transport to establish a set of methods of flux analysis based on the velocity and turbidity of flow. And finally corrected for capture efficiency by particle size. The combination of analytical methods and 3D sediment trap could provide technological support for investigating the evolution of the sea, ecological cycle, and marine engineering

Development and application of a 6000-meter double decelerating lander

The deep-sea lander is an important equipment for in-situ detection and monitoring. It is of great significance to understand the benthic boundary layer’s physical, chemical, and ecological environment. A 6000-meter double decelerating lander was created to meet the deployment requirements of underwater detection and monitoring, allowing for long-term in-situ monitoring of several benthic boundary layer components. Protection of the installed ocean bottom seismometer (OBS) is required due to the lander’s and OBS’s different impact resistances. The double decelerating unit enables the OBS to avoid colliding with the seabed when the lander lands and then collides with the seabed at a slow speed rather than the speed at which the lander falls, which is intended to safeguard OBS from damage. To ensure a safe deployment, the lander’s static analysis and simulation were performed using ANSYS, and the motion characteristics of the application process were derived. Numerous data have been obtained after the lander’s successful application in the South China Sea. The lander provides an investigation approach for marine science and geochemistry, complementing a technical approach to marine environmental investigations

Fusarium pseudograminearum biomass and toxin accumulation in wheat tissues with and without Fusarium crown rot symptoms

Fusarium crown rot (FCR) is an important and devastating disease of wheat (Triticum aestivum) caused by the fungus Fusarium pseudograminearum and related pathogens. Using two distinct susceptible cultivars, we investigated the isolation frequencies of F. pseudograminearum and quantified its biomass accumulation and the levels of the associated toxins deoxynivalenol (DON) and DON-3-glucoside (D3G) in inoculated field-grown wheat plants. We detected F. pseudograminearum in stem, peduncle, rachis, and husk tissues, but not in grains, whereas DON and D3G accumulated in stem, rachis, husk, and grain tissues. Disease severity was positively correlated with the frequency of pathogen isolation, F. pseudograminearum biomass, and mycotoxin levels. The amount of F. pseudograminearum biomass and mycotoxin contents in asymptomatic tissue of diseased plants were associated with the distance of the tissue from the diseased internode and the disease severity of the plant. Thus, apparently healthy tissue may harbor F. pseudograminearum and contain associated mycotoxins. This research helps clarify the relationship between F. pseudograminearum occurrence, F. pseudograminearum biomass, and mycotoxin accumulation in tissues of susceptible wheat cultivars with or without disease symptoms, providing information that can lead to more effective control measures

Biological control of Fusarium crown rot of wheat with Chaetomium globosum 12XP1-2-3 and its effects on rhizosphere microorganisms

Chaetomium globosum is a common plant endophytic fungi that exhibits great biocontrol potential in plant disease. Fusarium crown rot (FCR) is an important disease in wheat that seriously threatens wheat production worldwide. The control effect of C. globosum against wheat FCR remains unclear. In this study, we introduced an identified C. globosum 12XP1-2-3 and tested its biological control potential against wheat FCR. The hypha and fermentation broth exhibited an antagonistic effect against Fusarium pseudograminearum. Results from indoor experiments showed that C. globosum 12XP1-2-3 might delay the onset of symptoms of brown stem base and significantly reduced the disease index (37.3%). Field trials showed that wheat seeds coated with a spore suspension of 12XP1-2-3 grew better than the control seeds, had control effects of 25.9–73.1% on FCR disease, and increased wheat yield by 3.2–11.9%. Analysis of rhizosphere microorganisms revealed that seeds coated with C. globosum (‘Cg’ treatment) had a greater effect on fungal rather than on bacterial alpha diversity and may improve the health state of rhizosphere microorganisms, as reflected by the significantly increased fungal Shannon index at Feekes 11 and the increased complexity of the bacterial co-occurrence network but decreased complexity of the fungal network. Moreover, the accumulation of beneficial bacteria such as Bacillus and Rhizobium at Feekes 3, and Sphingomonas at Feekes 7 in the ‘Cg’ treatment may be the important contributions to healthier wheat growth state, significantly reduced relative abundance of Fusarium at Feekes 11, and reduced occurrence of FCR disease. These results provide a basis for further research on the mechanism of action of C. globosum and its application in the biological control of FCR in the field

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Synthesis of vanadium phosphorus oxide catalysts promoted by iron-based ionic liquids and their catalytic performance in selective oxidation of n-butane

A series of vanadium phosphorus oxide (VPO) catalysts have been firstly synthesized using iron-based ionic liquids (ILs) as additives for selective oxidation of n-butane to maleic anhydride (MA) in this work. Meanwhile, VPO catalysts doped with inorganic iron salts were also prepared for comparison. The catalytic evaluation presented that iron-based IL modification remarkably enhanced the n-butane conversion and MA yield. A combination of techniques including XRD, Raman, TG, BET, SEM, TEM, XPS and H-2-TPR was employed to investigate the intrinsic distinction among these catalysts. The results demonstrated that iron-based ILs notably change the morphology of the VPO catalyst from a plate-like structure into chrysanthemum-shape clusters, leading to a significant increase in the surface area of the catalyst, and largely promote the formation of (VO)(2)P2O7. All of these were closely associated with the synergistic effect existing between the structure-oriented cations and metal anions in ILs during the preparation of the VPO catalyst. In addition, the differences in the structure and redox properties of the catalysts studied were also discussed and compared with those doped with conventional inorganic salt additives.</p

Effect of Particle Sizes of Nickel Powder on Thermal Conductivity of Epoxy Resin-Based Composites under Magnetic Alignment

Magnetically oriented three-phase composite systems of epoxy resin, aluminum nitride, and nickel have been prepared, the thermal conductivity of composites filled with nickel powder with different particle sizes and content under different applied magnetic fields was studied. The vibrating scanning magnetometer (VSM) and scanning electron microscopy (SEM) were applied to investigate the dispersion of nickel powder in the composites. The results showed that the anisotropic thermal conductivity of the composites treated by applied magnetic field forming chain structure is obtained. The epoxy resin-based composites filled with 30 vol% aluminum nitride with particle size of 1 &mu;m and 2 vol% nickel powder with particle size of 1 &mu;m and aligned with vertical magnetic field have the highest thermal conductivity (1.474 W/mk), which increases the thermal conductivity of the composites by 737% and 58% compared to the pure epoxy resin (0.2 W/mk) and the composites filled with 30 vol% aluminum nitride (0.933 W/mk). In addition, we simulated the influence of nickel powder particles with different particle sizes and arrangements on the thermal conductivity of the composite material in COMSOL Multiphysics software, and the results were consistent with the experimental results

Newly Designed and Experimental Test of the Sediment Trap for Horizontal Transport Flux

The transport processes of marine suspended sediments are important to the material cycle and the shaping of seafloor topography. Existing sediment monitoring methods are limited in their use under high concentration conditions, and are not effective in monitoring and capturing sediment in 3D directions, and there is an inability to accurately explain sediment transport processes. To infer the transport process of suspended sediments, this study proposed a time-series vector in situ observation device. An accompanying time-series analytic method was developed for sediment transport fluxes. The correlation between the internal and external flow velocities of the capture tube was established through indoor tests, and then the applicability of the device was verified by the correlation between the theoretical capture quality and the actual capture quality, and the analytic formula of the flux was refined. The proposed observation technique can be used for in situ long-term observation and sampling of marine suspended sediments under conventional and even extreme sea conditions, achieving accurate time-series suspended sediment capture and high-resolution transport flux analysis. The technique thus provides a more effective means for scientific research into the dynamics of seafloor sedimentation, the mechanisms of ocean carbon sinks, and the processes of the carbon cycle

Synthesis of Vanadium Phosphorus Oxide Catalysts Assisted by Deep-Eutectic Solvents for n-Butane Selective Oxidation

The effects of choline chloride/oxalic acid deep eutectic solvents (ChCl/OA DES) as a green and effective promoter assisting the synthesis of vanadium phosphorus oxide (VPO) catalysts for the selective oxidation of n-butane to maleic anhydride were investigated in detail. A combination of characterizations with the performance was considered to understand the essential effects of DES. DES play the role of a crystal induced agent and structural modifier, facilitating the formation of a single-crystal structure on the surface of precursor; correspondingly, topological transformation to the single-crystal active phase under the activation conditions accompany the decomposition of DES. It is suggested that ChCl/OA DES can interact with V2O5 and form a new vanadium complex, which affects the reaction between V2O5 and H3PO4. Meanwhile, the ChCl/OA DES could regulate the surface chemical state and redox characteristic, resulting in the enhancement on the catalytic performance of VPO

Sophoridine induces apoptosis and S phase arrest via ROS-dependent JNK and ERK activation in human pancreatic cancer cells

Abstract Background Pancreatic cancer is generally acknowledged as the most common primary malignant tumor, and it is known to be resistant to conventional chemotherapy. Novel, selective antitumor agents are pressingly needed. Methods CCK-8 and colony formation assay were used to investigate the cell growth. Flow cytometry analysis was used to evaluate the cell cycle and cell apoptosis. The peroxide-sensitive fluorescent probe DCFH-DA was used to measure the intracellular ROS levels. Western blot assay was used to detect the levels of cell cycle and apoptosis related proteins. Xenografts in nude mice were used to evaluate the effect of Sophoridine on pancreatic cancer cell in vivo. Results Sophoridine killed cancer cells but had low cytotoxicity to normal cells. Pancreatic cancer cells were particularly sensitive. Sophoridine inhibited the proliferation of pancreatic cancer cells and induced cell cycle arrest at S phase and mitochondrial-related apoptosis. Moreover, Sophoridine induced a sustained activation of the phosphorylation of ERK and JNK. In addition, Sophoridine provoked the generation of reactive oxygen species (ROS) in pancreatic cancer cells. Finally, in vivo, Sophoridine suppressed tumor growth in mouse xenograft models. Conclusion These findings suggest Sophoridine is promising to be a novel, potent and selective antitumor drug candidate for pancreatic cancer