198 research outputs found

    Effect of air core on the shape and discharge of the outflow through a bottom outlet

    Get PDF
    AbstractExperiments were conducted to study the generation of air core and its effect on the outflow shape and discharge in a cylindrical water tank with a bottom well-designed outlet. Depending on the stages of the air core in the tank, the outflow shape can vary from a smooth water jet to a smooth spindle shape with air-core, and to water sprays. The diameter of the nozzle size also has influence on the outflow pattern. The existence of the penetrated air core can dramatically reduce the outflow discharge, with the discharge coefficient decreasing with the nozzle diameter

    Interactive Blood-Coil Simulation in Real-time during Aneurysm Embolization

    Get PDF
    International audienceOver the last decade, remarkable progress has been made in the field of endovascular treatment of aneurysms. Technological advances continue to make it possible for a growing number of patients with cerebral aneurysms to be treated with a variety of endovascular strategies, essentially using detachable platinum coils. Yet, coil embolization remains a very complex medical procedure for which careful planning must be combined with advanced technical skills in order to be successful. In this paper, we describe a complete process for patient-specific simulations of coil embolization, from mesh generation with medical datasets to computation of coil-flow bilateral influence. We propose a new method for simulating the complex blood flow patterns that take place within the aneurysm, and for simulating the interaction of coils with this flow. This interaction is twofold, first involving the impact of the flow on the coil during the initial stages of its deployment, and second concerning the decrease of blood velocity within the aneurysm, as a consequence of coil packing. We also propose an approach to achieve real-time computation of coil-flow bilateral influence, necessary for interactive simulation. This in turns allows to dynamically plan coil embolization for two key steps of the procedure: choice and placement of the first coils, and assessment of the number of coils necessary to reduce aneurysmal blood velocity and wall pressure. Finally, we provide the blood flow simulation results on several aneurysms with interesting clinical characteristics both in 2D and 3D, as well as comparisons with a commercial package for validation. The coil embolization procesure is simulated within an aneurysm, and pre- and post-operative status is reported

    Regional correction calibration for OCF precipitation in flood season in Zhejiang Province based on cluster analysis

    Get PDF
    The forecast of rainstorm in flood season has always been the key and difficult point in the meteorological forecasting operation. First, we used the daily precipitation data from 2 227 meteorological stations in Zhejiang Province from 2016 to 2021 during the flood season (April to October), and divided the precipitation region by applying the K-means clustering algorithm, which employed the Euclidean distance as the similarity measure. Then, the regional correction method is formed by combing the spatial-temporally improved bias correction method and divided regions. Finally, we applied this method to perform the regional correction and validation on the Zhejiang Multi-Model Objective Consensus Forecast (OCF), compared with the overall correction not combined with divided regions.The results are as follows. (1) The K-means clustering algorithm can divide Zhejiang Province into 7 precipitation-similar regions, which show distinct regional characteristics closely related to the topographic features of Zhejiang Province. (2) According to validation during the 2021 flood season, the regional correction performed better than the overall correction in the OCF forecasts.Its main advantages lie in effectively reducing the false alarm of precipitation in the clear-rain forecast and substantially increasing the hit rate (POD) for the heavy rain and above, especially for the rainstorm and above from 0.25 to 0.41. (3) The typical validation show that, for both systematic and convective precipitation, the regional correction can significantly improve the intensity and falling area of precipitation for the rainstorm and above. Especially for the systematic precipitation, the regional correction demonstrated more remarkable effects, which can predict heavy rainstorms

    Biogenic Synthesis of Novel Functionalized Selenium Nanoparticles by Lactobacillus casei ATCC 393 and Its Protective Effects on Intestinal Barrier Dysfunction Caused by Enterotoxigenic Escherichia coli K88

    Get PDF
    Selenium (Se) is an essential element for human and animal health. Biogenic selenium nanoparticles (SeNPs) by microorganism possess unique physical and chemical properties and biological activities compared with inorganic Se and organic Se. The study was conducted to investigate the mainly biological activities of SeNPs by Lactobacillus casei ATCC 393 (L. casei 393). The results showed that L. casei 393 transformed sodium selenite to red SeNPs with the size of 50–80 nm, and accumulated them intracellularly. L. casei 393-SeNPs promoted the growth and proliferation of porcine intestinal epithelial cells (IPEC-J2), human colonic epithelial cells (NCM460), and human acute monocytic leukemia cell (THP-1)-derived macrophagocyte. L. casei 393-SeNPs significantly inhibited the growth of human liver tumor cell line-HepG2, and alleviated diquat-induced IPEC-J2 oxidative damage. Moreover, in vivo and in vitro experimental results showed that administration with L. casei 393-SeNPs protected against Enterotoxigenic Escherichia coli K88 (ETEC K88)-caused intestinal barrier dysfunction. ETEC K88 infection-associated oxidative stress (glutathione peroxidase activity, total superoxide dismutase activity, total antioxidant capacity, and malondialdehyde) was ameliorated in L. casei 393-SeNPs-treated mice. These findings suggest that L. casei 393-SeNPs with no cytotoxicity play a key role in maintaining intestinal epithelial integrity and intestinal microflora balance in response to oxidative stress and infection

    Polyunsaturated fatty acids modulate the association between PIK3CA-KCNMB3 genetic variants and insulin resistance

    Get PDF
    BACKGROUND:Neighboring genes PIK3CA and KCNMB3 are both important for insulin signaling and β-cell function, but their associations with glucose-related traits are unclear. OBJECTIVE:The objective was to examine associations of PIK3CA-KCNMB3 variants with glucose-related traits and potential interaction with dietary fat. DESIGN:We first investigated genetic associations and their modulation by dietary fat in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study (n = 820). Nine single-nucleotide polymorphisms (SNPs) were selected for analysis, covering more than 80% of the SNPs in the region. We then sought to replicate the findings in the Boston Puerto Rican Health Study (BPRHS) (n = 844). RESULTS:For KCNMB3 missense mutation rs7645550, meta-analysis indicated that homeostasis model assessment of insulin resistance (HOMA-IR) was significantly lower in minor allele T homozygotes compared with major allele C carriers (pooled P-value = 0.004); for another SNP rs1183319, which is in moderate LD with rs7645550, minor allele G carriers had higher HOMA-IR compared with non-carriers in both populations (pooled P-value = 0.028). In GOLDN, rs7645550 T allele homozygotes had lower HOMA-IR only when dietary n-3: n-6 PUFA ratio was low (≤0.11, P = 0.001), but not when it was high (>0.11, P-interaction = 0.033). Similar interaction was observed between rs1183319 and n-3: n-6 PUFA ratio on HOMA-IR (P-interaction = 0.001) in GOLDN. Variance contribution analyses in GOLDN confirmed the genetic association and gene-diet interaction. In BPRHS, dietary n-3: n-6 PUFA ratio significantly modulated the association between rs1183319 and HbA1c (P-interaction = 0.034). CONCLUSION:PIK3CA-KCNMB3 variants are associated with insulin resistance in populations of different ancestries, and are modified by dietary PUFA

    The COP9 signalosome complex regulates fungal development and virulence in the wheat scab fungus Fusarium graminearum

    Get PDF
    The COP9 signalosome (Csn) complex is an evolutionarily conserved complex that regulates various important cellular processes. However, the function of the Csn complex in pathogenic fungi remains elusive. Here, the distribution of Csn subunits in the fungal kingdom was surveyed, and their biological functions were systematically characterized in the fungal pathogen Fusarium graminearum, which is among the top 10 plant fungal pathogens. The results obtained from bioinformatic analyses suggested that the F. graminearum Csn complex consisted of seven subunits (Csn1–Csn7) and that Csn5 was the most conserved subunit across the fungi kingdom. Yeast two-hybrid assays demonstrated that the seven Csn subunits formed a complex in F. graminearum. The Csn complex was localized to both the nucleus and cytoplasm and necessary for hyphal growth, asexual and sexual development and stress response. Transcriptome profiling revealed that the Csn complex regulated the transcription abundance of TRI genes necessary for mycotoxin deoxynivalenol (DON) biosynthesis, subsequently regulating DON production to control fungal virulence. Collectively, the roles of the Csn complex in F. graminearum were comprehensively analyzed, providing new insights into the functions of the Csn complex in fungal virulence and suggesting that the complex may be a potential target for combating fungal diseases
    • …
    corecore