47 research outputs found

    Control measures about vibration and noise of pipeline onboard marine vessels

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    The pipeline noise is an important part of the sources of vibration and noise for high performance marine vessels. It is vital to control the vibration and noise of the onboard pipeline to improve the acoustic stealth and life level in marine vessels. The vibration and noise caused by the onboard pipeline system was analyzed. Some methods and advices were put forwards to reduce the vibration and noise caused by the pipeline system, including the control of vibration, structural noise and fluid noise. In addition, a new concept “pressure-stabilized bladder” was created

    The serum matrix metalloproteinase-9 level is an independent predictor of recurrence after ablation of persistent atrial fibrillation

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    OBJECTIVES: This study investigated whether the serum matrix metalloproteinase-9 level is an independent predictor of recurrence after catheter ablation for persistent atrial fibrillation. METHODS: Fifty-eight consecutive patients with persistent atrial fibrillation were enrolled and underwent catheter ablation. The serum matrix metalloproteinase-9 level was detected before ablation and its relationship with recurrent arrhythmia was analyzed at the end of the follow-up. RESULTS: After a mean follow-up of 12.1±7.2 months, 21 (36.2%) patients had a recurrence of their arrhythmia after catheter ablation. At baseline, the matrix metalloproteinase-9 level was higher in the patients with recurrence than in the non-recurrent group (305.77±88.90 vs 234.41±93.36 ng/ml, respectively, p=0.006). A multivariate analysis showed that the matrix metalloproteinase-9 level was an independent predictor of arrhythmia recurrence, as was a history of atrial fibrillation and the diameter of the left atrium. CONCLUSION: The serum matrix metalloproteinase-9 level is an independent predictor of recurrent arrhythmia after catheter ablation in patients with persistent atrial fibrillation

    Bioinformatics-integrated screening of systemic sclerosis-specific expressed markers to identify therapeutic targets

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    BackgroundSystemic sclerosis (SSc) is a rare autoimmune disease characterized by extensive skin fibrosis. There are no effective treatments due to the severity, multiorgan presentation, and variable outcomes of the disease. Here, integrated bioinformatics was employed to discover tissue-specific expressed hub genes associated with SSc, determine potential competing endogenous RNAs (ceRNA) regulatory networks, and identify potential targeted drugs.MethodsIn this study, four datasets of SSc were acquired. To identify the genes specific to tissues or organs, the BioGPS web database was used. For differentially expressed genes (DEGs), functional and enrichment analyses were carried out, and hub genes were screened and shown in a network of protein-protein interactions (PPI). The potential lncRNA–miRNA–mRNA ceRNA network was constructed using the online databases. The specifically expressed hub genes and ceRNA network were validated in the SSc mouse and in normal mice. We also used the receiver operating characteristic (ROC) curve to determine the diagnostic values of effective biomarkers in SSc. Finally, the Drug-Gene Interaction Database (DGIdb) identified specific medicines linked to hub genes.ResultsThe pooled datasets identified a total of 254 DEGs. The tissue/organ-specifically expressed genes involved in this analysis are commonly found in the hematologic/immune system and bone/muscle tissue. The enrichment analysis of DEGs revealed the significant terms such as regulation of actin cytoskeleton, immune-related processes, the VEGF signaling pathway, and metabolism. Cytoscape identified six gene cluster modules and 23 hub genes. And 4 hub genes were identified, including Serpine1, CCL2, IL6, and ISG15. Consistently, the expression of Serpine1, CCL2, IL6, and ISG15 was significantly higher in the SSc mouse model than in normal mice. Eventually, we found that MALAT1-miR-206-CCL2, let-7a-5p-IL6, and miR-196a-5p-SERPINE1 may be promising RNA regulatory pathways in SSc. Besides, ten potential therapeutic drugs associated with the hub gene were identified.ConclusionsThis study revealed tissue-specific expressed genes, SERPINE1, CCL2, IL6, and ISG15, as effective biomarkers and provided new insight into the mechanisms of SSc. Potential RNA regulatory pathways, including MALAT1-miR-206-CCL2, let-7a-5p-IL6, and miR-196a-5p-SERPINE1, contribute to our knowledge of SSc. Furthermore, the analysis of drug-hub gene interactions predicted TIPLASININ, CARLUMAB and BINDARIT as candidate drugs for SSc

    Skills' sets and shared benefits: perceptions of resettled people from the Yangtze-Huai River Diversion Project in China

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    Development induced displacement and resettlement (DIDR) projects should share their benefits with those affected by them. This paper shows that in the case of the Yangtze-Huai River Diversion Project in China perceptions of compensation received differs amongst different groups of resettled people even if levels of compensation are similar. Based on a survey with displaced people, a fuzzy comprehensive evaluation concludes that those with generic skills’ sets are the most satisfied, mainly because they are able to find new work and re-establish livelihoods after resettlement more quickly. On the other hand, those with only agricultural skills find it difficult to re-establish their livelihood and are often dissatisfied. Finally, those who did not have any work before resettlement were found to be satisfied overall as their life quality is said to have improved. The skills of those affected are therefore a key explanatory factor for satisfaction with compensation following resettlement

    Effect of support on printed properties in fused deposition modelling processes

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    Additive manufacturing still suffers from redundant support material usage when printing parts with overhanging features. All the supports will be removed after fabrication, resulting in wasted materials. There are many works conducted for reducing support waste by improving support strategies. However, using different support strategies may lead to different printed qualities. In this paper, the effect of support strategy on printed qualities is investigated in fused deposition modelling processes. Three different support strategies are adopted for manufacturing the same 3D part. The finished surface roughness and flexural properties are compared for evaluating different support strategies, as well as the material waste and printing time. The results show that different support strategies may result in different printed surface roughness and flexural properties. To achieve the balance between support consumption and properties of printed parts, it becomes necessary to understand the effect of supports on printed qualities for choosing a best support strategy

    Evaluation of river connectivity using a composite index method and its impact on nutrients dynamics in large rivers

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    The connectivity of large rivers is impaired by human activities, which could cause severe consequences to hydrodynamics, water quality. To clarify the changes in hydrological connectivity of large rivers and their effects on nutrients, a composite index method of river connectivity in longitudinal, lateral and vertical dimensions was developed in this study. Taking the middle reaches of the Yangtze River as an example, the hydrological connectivity of typical hydrological years and periods in the region was analyzed, and the responses of critical nutrient indexes to varied river connectivity was assessed. The results showed that significant temporal and spatial variations in river connectivity were observed, with better river connectivity in the wet year than the dry year, and worse connectivity in headwaters, tributaries, or downstream of gates and dams than other river reaches. This was mainly due to the degree of river fragmentation (DOF) and the degree of regulation (DOR) with a relative importance of 81.28% and 56.07%, respectively, implying that gate and dam interception was the main cause of impaired river connectivity in the study area. Statistical methods indicated that the impaired connectivity in the middle reaches of the Yangtze River implied a stronger retention of nutrients by dams, and that retention effect was greater during the flood period than the non-flood period. The stronger negative correlation between connectivity and TP (correlation coefficient = −0.58) than TN (correlation coefficient = −0.46) during the flood period revealed that phosphorus was more influenced by river connectivity. The results of this study provide important information on water resources and water quality for the management of large rivers

    BP Neural Network Could Help Improve Pre-miRNA Identification in Various Species

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    MicroRNAs (miRNAs) are a set of short (21–24 nt) noncoding RNAs that play significant regulatory roles in cells. In the past few years, research on miRNA-related problems has become a hot field of bioinformatics because of miRNAs’ essential biological function. miRNA-related bioinformatics analysis is beneficial in several aspects, including the functions of miRNAs and other genes, the regulatory network between miRNAs and their target mRNAs, and even biological evolution. Distinguishing miRNA precursors from other hairpin-like sequences is important and is an essential procedure in detecting novel microRNAs. In this study, we employed backpropagation (BP) neural network together with 98-dimensional novel features for microRNA precursor identification. Results show that the precision and recall of our method are 95.53% and 96.67%, respectively. Results further demonstrate that the total prediction accuracy of our method is nearly 13.17% greater than the state-of-the-art microRNA precursor prediction software tools

    New approach to dilation of stenotic lesions through the accessory hepatic vein in Budd-Chiari syndrome

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    We investigated a new approach to dilation of stenotic lesions through the femoral vein-accessory hepatic vein-intrahepatic communicating branched vein-hepatic vein-inferior vena cava loop in two cases of Budd-Chiari syndrome. For some selected patients, this approach represents an additional method to increase technical success and to decrease complications

    Dietary Neutral Detergent Fiber Levels Impacting Dairy Cows’ Feeding Behavior, Rumen Fermentation, and Production Performance during the Period of Peak-Lactation

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    This study investigated the impact of dietary neutral detergent fiber (NDF) levels (25.49%, 28.65%, 31.66%, and 34.65%, respectively) on the feeding behavior, rumen fermentation, cellulolytic bacteria, and production performance of dairy cows during peak lactation. A feeding experiment was conducted using four fistulated Holstein dairy cows (600 ± 25 kg) with days in milk (50 ± 15 days), employing a 4 × 4 Latin square design to assign the cows to four groups. The results demonstrated that increasing NDF levels in the diet had the following effects: (1) A linear decrease in dry matter intake (DMI), NDF intake, and physically effective NDF8.0 (peNDF8.0) intake; a linear increase in the average time spent eating and ruminating, as well as the time spent eating and ruminating per kilogram of dry matter (DM); a quadratic response in the time spent ruminating per kilogram of NDF and peNDF8.0. (2) A linear increase in average pH value, acetate concentration, and the proportions of Fibrobacter succinogenes and Ruminococcus flavefaciens among total bacteria; a linear decrease in ammonia nitrogen (NH3-N) concentration, microbial crude protein (MCP), total volatile fatty acid (TVFA), propionate, butyrate, and lactate. (3) A linear decrease in milk yield, milk protein percentage, and nitrogen efficiency of dairy cows; a linear increase in milk fat percentage and milk urea nitrogen (MUN) concentration. Based on the combined results, it was found that diets with 25% and 34% NDF had detrimental effects on the feeding behavior, rumen fermentation, and production performance of dairy cows. However, the diet with 28% NDF showed superior outcomes in production performance compared to the one with 31% NDF. Therefore, it is strongly recommended to include a diet containing 28% NDF during the critical peak lactation period for dairy cows
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