28 research outputs found

    Monitoring Level Fluctuations of the Lakes in the Yangtze River Basin from Radar Altimetry

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    Water level variations in four natural lakes, Poyang, Dongting, Tai, and Chao, within the Yangtze River basin are studied using ENVISAT GDRs. The GDRs were edited using simple editing criteria and appropriate geophysical corrections applied. Altimeter-derived lake level variation time series were then generated and analyzed. The results of this study, which is the first of its kind in using data from ENVISAT missions over the Yangtze River basin in China, reveal that the water level changes in these four lakes directly reflect the water level of the Yangtze River and contribute to the floods and their associated disasters that usually occur in the middle and lower reaches of the Yangtze River

    Regulatory and functional divergence among members of Ibβfruct2, a sweet potato vacuolar invertase gene controlling starch and glucose content

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    Sweet potato [Ipomoea batatas (L.) Lam.] is an important food and industrial crop. Its storage root is rich in starch, which is present in the form of granules and represents the principal storage carbohydrate in plants. Starch content is an important trait of sweet potato controlling the quality and yield of industrial products. Vacuolar invertase encoding gene Ibβfruct2 was supposed to be a key regulator of starch content in sweet potato, but its function and regulation were unclear. In this study, three Ibβfruct2 gene members were detected. Their promoters displayed differences in sequence, activity, and cis-regulatory elements and might interact with different transcription factors, indicating that the three Ibβfruct2 family members are governed by different regulatory mechanisms at the transcription level. Among them, we found that only Ibβfruct2-1 show a high expression level and promoter activity, and encodes a protein with invertase activity, and the conserved domains and three conserved motifs NDPNG, RDP, and WEC are critical to this activity. Only two and six amino acid residue variations were detected in sequences of proteins encoded by Ibβfruct2-2 and Ibβfruct2-3, respectively, compared with Ibβfruct2-1; although not within key motifs, these variations affected protein structure and affinities for the catalytic substrate, resulting in functional deficiency and low activity. Heterologous expression of Ibβfruct2-1 in Arabidopsis decreased starch content but increased glucose content in leaves, indicating Ibβfruct2-1 was a negative regulator of starch content. These findings represent an important advance in understanding the regulatory and functional divergence among duplicated genes in sweet potato, and provide critical information for functional studies and utilization of these genes in genetic improvement

    A Voltage Sag Severity Evaluation Method for the System Side Which Considers the Influence of the Voltage Tolerance Curve and Sag Type

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    Considering the influence of user equipment voltage tolerance characteristics and sag types on the evaluation results, this paper proposes a voltage sag severity evaluation method for the system side which considers the influence of the voltage tolerance curve and sag type. As such, a quantitative evaluation of the severity of voltage sag events can be achieved. Firstly, the user’s voltage tolerance curve is used to construct the comparison reference value of the energy index, in order to realize the rapid analysis of the severity of the sag event in the normal area and the abnormal area. Secondly, aiming at the problem of insufficient descriptions of the severity difference of sag events in uncertain areas, an improved energy index evaluation model combined with user tolerance characteristics is established through an interval division and interval weight calculation, so as to divide and evaluate the severity of sag events in uncertain areas. Considering the influence of the sag type on the voltage tolerance curve and user equipment, the energy index correction factor is then constructed, and the measurement function is used for an interval evaluation to obtain the ranking result of the voltage sag severity, which is more in line with the actual situation. Finally, the rationality and effectiveness of the proposed method are verified by analyzing 24 voltage sag events at a monitoring node

    Research advances on the influence of typical geochemical and hydrogeological characteristics on the natural attenuation of pollutants

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    As an effective risk prevention and control tool for contaminated sites, Monitoring Natural Attenuation (MNA) has been applied worldwide. The core of this technology is to determine the ability and efficiency of pollutant attenuation, which are influenced by the nature of the pollutants themselves, as well as the typical geochemical and hydrogeological conditions and other inherent characteristics of the site. It is of greater practical importance to clarify the influence of the inherent properties of the site on the natural attenuation of pollutants for the rational application of the technology. The authors address the influence of typical site geochemical characteristics and hydrogeological characteristics on the natural attenuation process of pollutants in groundwater and its mechanism. The typical geochemical characteristics, such as the organic matter and mineral composition of sediments, control the adsorption and complexation behavior of pollutants, and participate in the electron transfer process to influence the biodegradation and chemical transformation of pollutants. Hydrogeological characteristics influence the ability of natural attenuation through the differences in permeability, adsorption and desorption capacity caused by the lithologic characteristics of sediments. Groundwater flow rate controls the convection and dispersion of pollutants and affects the dissolution and release of pollutants from sediment to groundwater as well as the kinetic process of biodegradation. In general, due to the complexity of organic matter, mineral and microbial components and the heterogeneity of hydrogeological conditions, the study of the influence of site intrinsic properties on the natural attenuation of pollutants needs to be further strengthened. In particular, we need to identify the spatial and temporal dynamics of pollutant attenuation through long-term site monitoring, and deepen the understanding of the mechanisms underlying the interaction between typical site geochemistry, hydrogeological conditions and pollutants

    MCM-41-Accelerated PWA Catalysis of Friedel-Crafts Reaction of Indoles and Isatins

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    Ordered mesoporous siliceous material has been identified as one of the key elements of the catalysis concept. Here we report an efficient Friedel-Crafts reaction of indoles with isatins catalyzed by PWA/MCM-41, which got the di(indolyl)indolin-2-ones derivatives with high yield. Moreover, the catalysts were characterized by XRD and SEM/EDS, the EDS spectrum indicated that the catalyst used in this reaction also contains tungsten, and the proposed mechanism for the synthesis of 3,3-di(indolyl)indolin-2-ones was also discussed. Finally, the catalyst can be reused repeatedly for several times without obvious loss of activity

    Correlationship between Ki67, VEGF, and p53 and Hepatocellular Carcinoma Recurrence in Liver Transplant Patients

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    Background and Aims. Patients with hepatocellular carcinoma (HCC) who undergo orthotopic liver transplantation (OLT) are at risk for posttransplant tumor recurrence. The aim of this study was to evaluate the correlation between the expression of Ki67, VEGF, and p53 in HCC and clinicopathological characteristics of HCC patients, as well as their predictive value for HCC recurrence after OLT. Methods. 60 patients who underwent OLT and were found to have HCC in the liver explant. The expression of Ki67, VEGF, and p53 in HCC was detected by immunohistochemistry. Results. Ki67 was associated with the tumor number and the grade of differentiation at baseline. VEGF was associated with the diameter and number of tumors, tumor differentiation, and lymph node metastasis. p53 was associated with the tumor diameter and tumor encapsulation. The expression of Ki67, VEGF, and p53 in HCC was correlated with the tumor recurrence after OLT, respectively. Among them, VEGF was an independent predictor for tumor recurrence after OLT. Conclusion. Ki67, VEGF, and p53 are associated with the recurrence of HCC after OLT. VEGF independently predicts the recurrence of HCC

    Genome-Wide Identification of Flowering-Time Genes in <i>Brassica</i> Species and Reveals a Correlation between Selective Pressure and Expression Patterns of Vernalization-Pathway Genes in <i>Brassica napus</i>

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    Flowering time is a key agronomic trait, directly influencing crop yield and quality. Many flowering-time genes have been identified and characterized in the model plant Arabidopsis thaliana; however, these genes remain uncharacterized in many agronomically important Brassica crops. In this study, we identified 1064, 510, and 524 putative orthologs of A. thaliana flowering-time genes from Brassica napus, Brassica rapa, and Brassica oleracea, respectively, and found that genes involved in the aging and ambient temperature pathways were fewer than those in other flowering pathways. Flowering-time genes were distributed mostly on chromosome C03 in B. napus and B. oleracea, and on chromosome A09 in B. rapa. Calculation of non-synonymous (Ka)/synonymous substitution (Ks) ratios suggested that flowering-time genes in vernalization pathways experienced higher selection pressure than those in other pathways. Expression analysis showed that most vernalization-pathway genes were expressed in flowering organs. Approximately 40% of these genes were highly expressed in the anther, whereas flowering-time integrator genes were expressed in a highly organ-specific manner. Evolutionary selection pressures were negatively correlated with the breadth and expression levels of vernalization-pathway genes. These findings provide an integrated framework of flowering-time genes in these three Brassica crops and provide a foundation for deciphering the relationship between gene expression patterns and their evolutionary selection pressures in Brassica napus

    Genome-Wide Identification and Characterization of NODULE-INCEPTION-Like Protein (NLP) Family Genes in Brassica napus

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    NODULE-INCEPTION-like proteins (NLPs) are conserved, plant-specific transcription factors that play crucial roles in responses to nitrogen deficiency. However, the evolutionary relationships and characteristics of NLP family genes in Brassica napus are unclear. In this study, we identified 31 NLP genes in B. napus, including 16 genes located in the A subgenome and 15 in the C subgenome. Subcellular localization predictions indicated that most BnaNLP proteins are localized to the nucleus. Phylogenetic analysis suggested that the NLP gene family could be divided into three groups and that at least three ancient copies of NLP genes existed in the ancestor of both monocots and dicots prior to their divergence. The ancestor of group III NLP genes may have experienced duplication more than once in the Brassicaceae species. Three-dimensional structural analysis suggested that 14 amino acids in BnaNLP7-1 protein are involved in DNA binding, whereas no binding sites were identified in the two RWP-RK and PB1 domains conserved in BnaNLP proteins. Expression profile analysis indicated that BnaNLP genes are expressed in most organs but tend to be highly expressed in a single organ. For example, BnaNLP6 subfamily members are primarily expressed in roots, while the four BnaNLP7 subfamily members are highly expressed in leaves. BnaNLP genes also showed different expression patterns in response to nitrogen-deficient conditions. Under nitrogen deficiency, all members of the BnaNLP1/4/5/9 subfamilies were upregulated, all BnaNLP2/6 subfamily members were downregulated, and BnaNLP7/8 subfamily members showed various expression patterns in different organs. These results provide a comprehensive evolutionary history of NLP genes in B. napus, and insight into the biological functions of BnaNLP genes in response to nitrogen deficiency

    Protective Effect of Sika Deer (Cervus nippon) Velvet Antler Extract against Cisplatin-Induced Kidney and Liver Injury in a Prostate Cancer PC-3 Cell Xenograft Model

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    We previously discovered the antioxidant and antiprostate cancer effects of antler extract (AE), but whether it inhibits cisplatin- (Cis-) induced toxicity has not been investigated. In this study, the effect of AE on Cis-induced side effects in the kidney and liver using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide-based cytotoxicity and cell cycle assays in prostate cancer PC-3 cells in vitro is investigated. Furthermore, we used a xenograft mouse model of the same cells to examine the in vivo effects and mechanisms of action. Cis and Cis + AE treatment attenuated prostate cancer cell growth by inducing apoptosis in vitro. Cis + AE stimulated cleaved caspases 3, 7, and 9 and polyadenosine diphosphate ribose polymerase expression. Cis + AE treatment for 1 week significantly increased the superoxide dismutase and catalase antioxidant activity while thiobarbituric acid reactive substances decreased. The histopathological damage and tumor necrosis factor-α, interleukin- (IL-) 1β and IL-6, cyclooxygenase-2, and inducible nitric oxide synthase expression in the kidney and liver tissue decreased. Therefore, AE likely possesses antiprostate cancer activity and inhibits Cis toxicity

    Systematic Characterization of Brassica napus HIR Gene Family Reveals a Positive Role of BnHIR2.7 in Sclerotinia sclerotiorum Resistance

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    Hypersensitive-induced response protein (HIR) is a class of plant immune proteins that play pivotal roles in Sclerotinia sclerotiorum (Lib.) de Bary resistance. However, there has been no systematic investigation and identification of HIR genes in rapeseed (Brassica napus L.). Hence, we identified 50 BnHIR genes and classified them into four groups. Subcellular localization prediction suggested that HIR proteins are mainly localized in the mitochondria. Cis-acting elements involved in light and diverse abiotic stress were found in the promoter regions of BnHIR. The majority of BnHIR genes in Groups 1/3/4 were expressed in most examined tissues, especially in leaves and siliques pericarp, while the BnHIR genes in Group 2 were not or had low expression in all detected tissues. In the case of S. sclerotiorum inoculation, HIR genes in Groups 1/3/4 were strongly induced, especially homologous genes in Group 1, which exhibited different expression patterns. Moreover, overexpression of BnHIR2.7 in Arabidopsis thaliana illustrated its prominent resistance to S. sclerotiorum. Our study provides insight into the evolutionary relationships of the HIR family genes in B. napus and lays the foundation for their resistance to S. sclerotiorum in B. napus
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