20 research outputs found

    Effects of different stocking densities on the CO2 fluxes at water-air interface and the respiration metabolism in sea cucumber Apostichopus japonicus (Selenka)

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    Recently, abundant research has been devoted to investigating the variations of CO2 concentration in the atmosphere. However, the information of CO2 fluxes at the water-air interface remains limited, especially those from the respiratory metabolism of aquatic organisms. In the present study, a comprehensive analysis was carried out to evaluate the effects of different stocking densities of sea cucumber (Apostichopus japonicus) on the CO2 fluxes at water-air interface, and to explore the relationships between CO2 fluxes and respiratory metabolism. A total of 60 sea cucumbers were randomly classified into 4 groups with different stocking densities, including 2, 5 and 8 ind./tank (namely D2, D5 and D8 groups). After 34-day feeding trial, individuals in D5 had superior growth performance rather than D2 and D8. The analysis of modified floating static chambers clearly showed that the mean CO2 flux at the water-air interface in D5 was significantly higher than D2 and D8. Meanwhile, energy budget analysis revealed that D5 had higher carbon and nitrogen utilization, excretion energy and metabolizable energy, suggesting relatively active respiration metabolism in moderate stocking density. The activities of pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase (OGDH) in respiratory tree and body wall tissues provided additional evidence for the higher respiration metabolism rate of individuals at D5, which may be responsible for the higher CO2 fluxes at the water-air interface. Transcriptome analysis was performed to uncover the molecular mechanism of respiratory metabolism affected by different stocking densities. The differentially expressed genes in respiration trees and body walls were significantly enriched in peroxisome, fatty acid degradation, and oxidative phosphorylation pathways. It may explain the differences of respiration metabolism rates at different stocking densities. The present study preliminarily revealed the CO2 fluxes variation at the water-air interface from aquatic invertebrates, and provided the scientific basis for the efficient and low-carbon agricultural technologies of sea cucumber

    Nuclear Magnetic Resonance Evaluation Study for Effect of Foam flooding in Heterogeneous Cores

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    Foam flooding demonstrated the ability to solve the viscous fingering problem of gas flooding and increase the sweep efficiency in enhancing oil recovery. It is commonly used in development of heterogeneous reservoirs. While the characteristics of fluid migration in pores and between layers were still unclear. In this paper, Dynamic change of oil and water with different foam quality was tested during foam flooding by NMR method. Oil displacement effect of water flooding and foam flooding was compared. The results showed the foam quality affected the foam stability and profile control effect. Compared with water flooding, the foam could increase the recovery rate of the low-permeability layer, and the foam system with high stability had a high sweep efficiency and a high oil displacement efficiency in the heterogeneous cores

    Interference of Urban Morphological Parameters in the Spatiotemporal Distribution of PM<sub>10</sub> and NO<sub>2</sub>, Taking Dalian as an Example

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    Recently, air quality has become a hot topic due to its profound impact on the quality of the human living environment. This paper selects the tourist city of Dalian as the research object. The concentration and spatial distribution of PM10 and NO2 in the main urban area were analyzed during the peak tourist seasons in summer and winter. Simulations were used to explore the spatial and temporal variation patterns of PM10 and NO2, combining building and road density at different scales to reveal the coupling relationship between individual pollutant components and urban parameters. The results show that the PM10 concentration is high in the center and NO2 is concentrated in the northern district of Dalian City. In an area with a radius of 100 m, the dilution ratio of building density and road density to the concentration of the PM10 pollutants is at least 43%. Still, the concentration of NO2 is only coupled with road density. This study reveals the spatial and temporal variation patterns of PM10 and NO2 in Dalian, and finds the coupling relationship between the two pollutants and building density and road density. This study provides a reference for preventing and controlling air pollution in urban planning

    Nuclear magnetic resonance experiments on foam flooding and evaluation of foam dynamic stability

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    A visualization experimental method of foam flooding was developed by combining nuclear magnetic resonance (NMR) and traditional core flooding method. On this basis, a new method to evaluate the dynamic stability of foam in the core during displacement process was established. Using this method, the displacement characteristics and dynamic stability of foam of S-2 (the main component is sodium lauryl sulfate) and S-NP-2 (the main components are sodium lauryl sulfate and silica nanoparticles) in two different displacement modes, i.e. direct foam flooding and foam flooding after water flooding, were studied. The results show that the NMR images and the T2 (transverse relaxation time) spectrum reflected the displacement characteristics. The flooding efficiency of S-2 and S-NP-2 after water flooding was increased by 18.05% and 25.68% and reached 63.72% and 67.50% respectively at last, higher than direct foam flooding. The same foam system had better stability in foam flooding after water flooding than in direct foam flooding, and foam S-NP-2 is more stable than foam S-2 under the same displacement mode. Key words: foam flooding, flooding experiment, flooding efficiency, nuclear magnetic resonance (NMR), foam stability, evaluation metho

    Colletotrichum higginsianum as a Model for Understanding Host–Pathogen Interactions: A Review

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    Colletotrichum higginsianum is a hemibiotrophic ascomycetous fungus that causes economically important anthracnose diseases on numerous monocot and dicot crops worldwide. As a model pathosystem, the Colletotrichum&ndash;Arabidopsis interaction has the significant advantage that both organisms can be manipulated genetically. The goal of this review is to provide an overview of the system and to point out recent significant studies that update our understanding of the pathogenesis of C. higginsianum and resistance mechanisms of Arabidopsis against this hemibiotrophic fungus. The genome sequence of C. higginsianum has provided insights into how genome structure and pathogen genetic variability has been shaped by transposable elements, and allows systematic approaches to longstanding areas of investigation, including infection structure differentiation and fungal&ndash;plant interactions. The Arabidopsis-Colletotrichum pathosystem provides an integrated system, with extensive information on the host plant and availability of genomes for both partners, to illustrate many of the important concepts governing fungal&ndash;plant interactions, and to serve as an excellent starting point for broad perspectives into issues in plant pathology

    Genome-Wide Analysis of Alternative Splicing (AS) Mechanism Provides Insights into Salinity Adaptation in the Livers of Three Euryhaline Teleosts, including <i>Scophthalmus maximus</i>, <i>Cynoglossus semilaevis</i> and <i>Oncorhynchus mykiss</i>

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    Salinity is an important environmental factor that directly affects the survival of aquatic organisms, including fish. However, the underlying molecular mechanism of salinity adaptation at post-transcriptional regulation levels is still poorly understood in fish. In the present study, 18 RNA-Seq datasets were utilized to investigate the potential roles of alternative splicing (AS) in response to different salinity environments in the livers of three euryhaline teleosts, including turbot (Scophthalmus maximus), tongue sole (Cynoglossus semilaevis) and steelhead trout (Oncorhynchus mykiss). A total of 10,826, 10,741 and 10,112 AS events were identified in the livers of the three species. The characteristics of these AS events were systematically investigated. Furthermore, a total of 940, 590 and 553 differentially alternative splicing (DAS) events were determined and characterized in the livers of turbot, tongue sole and steelhead trout, respectively, between low- and high-salinity environments. Functional enrichment analysis indicated that these DAS genes in the livers of three species were commonly enriched in some GO terms and KEGG pathways associated with RNA processing. The most common DAS genes work as RNA-binding proteins and play crucial roles in the regulation of RNA splicing. The study provides new insights into uncovering the molecular mechanisms of salinity adaptation in teleosts

    Case-Control Study and Meta-Analysis Show a Weak Association between ANTXR2 Polymorphisms and Ankylosing Spondylitis in Chinese Han

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    Previous studies have demonstrated associations of ANTXR2 gene polymorphisms with ankylosing spondylitis (AS). These associations differ depending on the ethnic populations and AS subgroups studied. Purposes of the current study were to evaluate the associations of 4 single nucleotide polymorphisms (SNPs) of the ANTXR2 gene with susceptibility to AS alone or AS in combination with acute anterior uveitis (AAU) in Chinese Han. Therefore, a case-control association study was performed in 880 AS+AAU-, 860 AS+AAU+, and 1700 healthy controls. Genotyping was performed using the iPLEXGold genotyping assay. Our results showed a weak association of rs6534639 AA genotype with AS+AAU+ patients (p=0.042), which was lost after correction for multiple comparisons. No other association was found between SNPs of ANTXR2 and susceptibility of AS+AAU- or AS+AAU+. A meta-analysis was performed to evaluate the associations of polymorphisms in the ANTXR2 gene with AS. Results showed a weak association of rs4389526 with AS susceptibility in all studies but failed to show an association of rs6534639 with AS in Chinese Han. Taken together, this study shows no association between ANTXR2 polymorphisms and AS susceptibility in a Chinese Han population, but meta-analysis showed that rs4389526 in the ANTXR2 gene was weakly associated with AS susceptibility in both Caucasian and Chinese Han patients

    Risk Assessment of Anopheles philippinensis and Anopheles nivipes (Diptera: Culicidae) Invading China under Climate Change

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    Background: Anopheles philippinensis and Anopheles nivipes are morphologically similar and are considered to be effective vectors of malaria transmission in northeastern India. Environmental factors such as temperature and rainfall have a significant impact on the temporal and spatial distribution of disease vectors driven by future climate change. Methods: In this study, we used the maximum entropy model to predict the potential global distribution of the two mosquito species in the near future and the trend of future distribution in China. Based on the contribution rate of environmental factors, we analyzed the main environmental factors affecting the distribution of the two mosquito species. We also constructed a disease vector risk assessment index system to calculate the comprehensive risk value of the invasive species. Results: Precipitation has a significant effect on the distribution of potentially suitable areas for Anopheles philippinensis and Anopheles nivipes. The two mosquito species may spread in the suitable areas of China in the future. The results of the risk assessment index system showed that the two mosquito species belong to the moderate invasion risk level for China. Conclusions: China should improve the mosquito vector monitoring system, formulate scientific prevention and control strategies and strictly prevent foreign imports

    Role of quality control circle in sustained improvement of hand hygiene compliance: an observational study in a stomatology hospital in Shandong, China

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    Abstract Background Hand hygiene is an important element of the WHO multimodal strategy for healthcare-associated infection control, whereas compliance of hand hygiene among healthcare workers (HCWs) remains a challenge to sustain. In order to increase the hand hygiene compliance of HCWs, a quality control circle (QCC) program was carried out in our hospital, and the plan-do-check-act (PDCA) method was applied for 12 months. Findings Hand hygiene compliance rates improved over time, with significant improvement between preintervention (60.1%) and postintervention (97.2%) periods (P < 0.001). Nurses (88.3%) exhibited higher compliance than dentists (87.3%), and female (88.4%) HCWs were more likely to perform hand hygiene than males (85.6%), both P < 0.001. Overall hand hygiene compliance and observance of the five indications exhibited significant linear increases over time (P < 0.005). Conclusion This study highlights the success of a multifaceted intervention, conducted by QCC program and PDCA method, which led to a significant improvement of hand hygiene compliance. Though training is the most basic intervention element, surveillance, evaluation and feedback should be explored as additional interventions to ensure that hand hygiene compliance is achieved and sustained at high levels

    Mitochondrial prohibitin complex regulates fungal virulence via ATG24-assisted mitophagy

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    Prohibitins recruit ChATG24 into the mitochondria to modulate mitophagy, thereby affecting the virulence of Colletotrichum higginsianum
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