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Carbon paper is one of the most commonly used materials for the gas diffusion layer of proton exchange membrane fuel cell, and its performance is the premise to ensure the stable operation of the cell. In order to improve the structure and properties of carbon paper and make it better meet the performance requirements of fuel cell, this study was conducted to press different amounts of graphite plates in the carbonization process to control the applied pressure and analyze the microstructure evolution and mechanism of carbon paper under different pressure. In addition, the effects of applied pressure on the in-plane resistivity, pore size distribution, surface roughness and mechanical properties of carbon paper were also studied. The results show that applying pressure helps to restrain the cracking of resin carbon, reduce the generation of cracks and improve graphitization degree of carbon paper to a certain extent. Furthermore, with the increase of applied pressure, the surface roughness of carbon paper is reduced gradually, while the average and maximum apertures also decrease. When the applied pressure reaches 3600 Pa, compared with the samples without pressure, the in-plane resistivity of carbon paper decreases from 17.15 mΩ·cm to 12.79 mΩ·cm, the tensile strength and flexural strength are improved by 150% and 82.9% respectively.

Due to its large specific surface area, excellent penetration resistance and a large number of functional groups distributed on the surface, graphene oxide(GO) has become a research hotspot in the fields of anticorrosion, permeation separation and coating mechanical properties. The research progress of GO application on metal surface in recent years was reviewed. On the basis of domestic and foreign literature, the research progress of GO applied on metal surface for anticorrosion, permeation separation, mechanical properties of coating and other aspects was described, and the mechanism was summarized and analyzed. The anticorrosion mechanism is mainly the physical barrier effect of GO and its chemical inertness to the electroactive medium. The mechanism of osmotic separation is mainly the multi-layer pore structure and functional groups of GO. The main mechanism of mechanical properties of the coating is the good compatibility between GO and coating and the formation of chemical bond between surface functional groups and metal matrix. It was pointed out that there is still a lack of GO composite preparation technology that meets the requirements of environmental protection, low cost and large-scale industrialization, the technological parameters involved, the design of composite phase system and other aspects still need further study. It was also proposed to be applied to metal anticorrosion, oil-water separation and mechanical properties of coating, so as to solve the key problems such as corrosion resistance of metal surface, oil-water permeability and separation performance, bonding force between coating and metal substrate.

Abstract Toxoplasmosis is a zoonotic infection of humans and animals, caused by the opportunistic protozoan Toxoplasma gondii, a parasite belonging to the phylum Apicomplexa. Infection in pregnant women may lead to abortion, stillbirth or other serious consequences in newborns. Infection in immunocompromised patients can be fatal if not treated. On average, one third of people are chronically infected worldwide. Although very limited information from China has been published in the English journals, T. gondii infection is actually a significant human health problem in China. In the present article, we reviewed the clinical features, transmission, prevalence of T. gondii infection in humans in China, and summarized genetic characterizations of reported T. gondii isolates. Educating the public about the risks associated with unhealthy food and life style habits, tracking serological examinations to special populations, and measures to strengthen food and occupational safety are discussed.

Abstract Liver flukes belonging to the genus Fasciola are among the causes of foodborne diseases of parasitic etiology. These parasites cause significant public health problems and substantial economic losses to the livestock industry. Therefore, it is important to definitively characterize the Fasciola species. Current phenotypic techniques fail to reflect the full extent of the diversity of Fasciola spp. In this respect, the use of molecular techniques to identify and differentiate Fasciola spp. offer considerable advantages. The advent of a variety of molecular genetic techniques also provides a powerful method to elucidate many aspects of Fasciola biology, epidemiology, and genetics. However, the discriminatory power of these molecular methods varies, as does the speed and ease of performance and cost. There is a need for the development of new methods to identify the mechanisms underpinning the origin and maintenance of genetic variation within and among Fasciola populations. The increasing application of the current and new methods will yield a much improved understanding of Fasciola epidemiology and evolution as well as more effective means of parasite control. Herein, we provide an overview of the molecular techniques that are being used for the genetic characterization, detection and genotyping of Fasciola spp..

AbstractThis study aims to explore the mechanisms of the inhibitory effect of kaempferol on the invasion and metastasis of gastric cancer (GC) cells through network pharmacology prediction and experimental verification. It identifies core targets via PPI network analysis and finds that kaempferol binds to these targets well. In vitro experiments showed that kaempferol could inhibit the proliferation, colony formation, migration and invasion of GC cells. Western blotting indicated kaempferol may reduce AKT and GSK3β phosphorylation, leading to lower expression of invasion-related genes SRC, MMP9, CXCR4, KDR, and MMP2. Overall, kaempferol may prevent migration and invasion of GC cells via the AKT/GSK3β signaling pathway. [ABSTRACT FROM AUTHOR]

Accumulated evidence has shown that microRNAs (miRNAs) are closely related to the pathogenesis and progression of senile cataracts. Here we investigate the effect of miR-29a-3p in cataractogenesis and determined the potential molecular mechanism involved. In this study, we constructed a selenite cataract model in rats and obtained the miRNAs related to cataracts by whole transcriptome sequencing. To investigate the effect and mechanism of miR-29a-3p on cataracts, we performed several in vivo and in vitro experiments, including CCK8 assay, flow cytometry, luciferase reporter assay, Edu assay, and western blot analysis. Sequencing data showed downregulation of miR-29a-3p in rats with selenite cataracts. Down-regulation of miR-29a-3p could promote lens epithelial cells (SRA01/04) proliferation and inhibit cell apoptosis, and miR-29a-3p silence could inhibit the development of cataracts. Additionally, CAND1 was a direct target gene for miR-29a-3p. These data demonstrate that miR-29a-3p inhibits apoptosis of lens epithelial cells by regulating CAND1, which may be a potential target for senile cataracts. [ABSTRACT FROM AUTHOR]

Alkaloids and lignans in Zanthoxylum armatum display important biological activities, but the quanitification method of alkaloids has not been reported. In this study, an effective extraction method was developed through an orthogonal design, and ten compounds in roots, stems, branches and leaves of Zanthoxylum armatum were simultaneously quantified by ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS). The roots, stems, branches and leaves of Z. armatum were ultrasonically extracted with methanol (solvent-to-sample ratio 100 : 1, v/w) for 10 min. An UFLC-MS/MS method was developed with a gradient UFLC mobile phase and triple quadruple tandem mass spectrometry with electrospray ionization in the positive ion mode. The method was validated for linearity, precision, repeatability and accuracy. The limits of detection and quantification were within 0.01-7.5 and 0.04-30 ng/mL, respectively. The root samples collected from Tian'e County were abundant in N-methylanhydrotetrahydroberberrubine A, escholidine perchlorate and pinoresinol monomethyl ether, eudesminthe., Author(s): Yi-ran Wang [sup.1], Shi-ying Mai [sup.1], Yong-hui Li [sup.1], Hai-long Li [sup.1], Tao Guo [sup.3], An Jia [sup.2], Jun-qing Zhang [sup.1] [sup.2] Author Affiliations: (1) grid.443397.e, 0000 0004 0368 [...]