60 research outputs found

    Research on the dynamic characteristics of mast mechanism of rotary drilling rig

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    AbstractIn order to express the inherent complex dynamic characteristics of mast mechanism of rotary drilling rig synthetically and improve the smooth-going property of key parts and related hydraulic system in the lifting process. firstly, a dynamic model of mast mechanism based on Newton-Euler method is established, then a hydraulic system model of mast mechanism based on power bond graph is built up, a set of optimal installation position parameters are got for designers to refer by analyzing and comparing the impact of the dynamic characteristics in lifting process by changing the installation position of mast mechanism. The integrated modeling method is expected to be a theoretical basis for designing the mast system of rotary drilling rig

    Effect of cucurbitacin on malignant biological behavior of breast cancer cells, and its possible underlying mechanism

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    Purpose: To study the influence of cucurbitacin on malignant biological behavior of mammary carcinoma cells, and the likely mechanism involved.Methods: Human mammary carcinoma cell line MDA-MB-436 was selected for cell culture and treated with different concentrations of cucurbitacin. The effect of cucurbitacin on cell activity, cell colonyformation capacity, cell invasion, migration potential, matrix metalloproteinase-9 (MMP-9) activity, and levels of vascular endothelial growth factor A (VEGFA), epithelial calcium adhesion (E-cadherin), and neurogenic calcium adhesion (N-cadherin) were measured. Moreover, levels of wave protein (vimentin), phosphorylated epidermal growth factor receptor (p-EGFR), phosphorylated signaling transduction, and transcription activation factor 3 (p-STAT3) and phosphorylated protein kinase B (p-Akt) were determined.Results: With increase in cucurbitacin dose, there was significant decrease in cell viability, cell colony ratio, cell invasion and migration capacity, and expression levels of MMP-9, VEGFA, e-cadherin, ncadherin, vimentin, P-EGFR, P-STAT3 and p-Akt (p < 0.05).Conclusion: Cucurbitacin inhibits the proliferation, invasion, and migration of breast cancer cells by down-regulating the expressions of EGFR/STAT3/Akt signaling-related proteins, and inhibiting epithelial-mesenchymal transition transformation

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Strategic project selection based on evidential reasoning approach for high-end equipment manufacturing industry

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    With the rapid development of science and technology, emerging information technologies have significantly changed the daily life of people. In such context, strategic project selection for high-end equipment manufacturing industries faces more and more complexities and uncertainties with the consideration of several complex criteria. For example, a group of experts rather than a single expert should be invited to select strategic project for high-end equipment manufacturing industries and the experts may feel difficulty to express their preferences towards different strategic projects due to their limited cognitive capabilities. In order to handle these complexities and uncertainties, the criteria framework of strategic project selection is firstly constructed based on the characteristics of high-end equipment manufacturing industries and then evidential reasoning (ER) approach is introduced in this paper to help experts express their uncertain preferences and aggregate these preferences to generate an appropriate strategic project. A real case of strategic project selection in a high-speed train manufacturing enterprise is investigated to demonstrate the validity of the ER approach in solving strategic project selection problem

    Strategic project selection based on evidential reasoning approach for high-end equipment manufacturing industry

    No full text
    With the rapid development of science and technology, emerging information technologies have significantly changed the daily life of people. In such context, strategic project selection for high-end equipment manufacturing industries faces more and more complexities and uncertainties with the consideration of several complex criteria. For example, a group of experts rather than a single expert should be invited to select strategic project for high-end equipment manufacturing industries and the experts may feel difficulty to express their preferences towards different strategic projects due to their limited cognitive capabilities. In order to handle these complexities and uncertainties, the criteria framework of strategic project selection is firstly constructed based on the characteristics of high-end equipment manufacturing industries and then evidential reasoning (ER) approach is introduced in this paper to help experts express their uncertain preferences and aggregate these preferences to generate an appropriate strategic project. A real case of strategic project selection in a high-speed train manufacturing enterprise is investigated to demonstrate the validity of the ER approach in solving strategic project selection problem

    hsa_circ_0081143 promotes cisplatin resistance in gastric cancer by targeting miR-646/CDK6 pathway

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    Abstract Background Increasing studies indicated that circRNAs play critical roles in tumor progression. However, the roles and underlying mechanisms of circRNAs in gastric cancer (GC) remain largely unclear. Methods Microarray assay was used to screen the abnormally expressed circRNAs in GC. Cell viability assay, transwell assay and in vivo assay were performed to assess the effects of hsa_circ_0081143 on GC cells. Next, interaction between hsa_circ_0081143 and miR-646 was detected by luciferase reporter assay and RNA pull-down assay. Results High throughput microarray assay showed that hsa_circ_0081143 was upregulated in GC tissues, which was further confirmed by qRT-PCR. Correlation analysis showed that high hsa_circ_0081143 expression was associated with the advanced TNM stage, lymphnode metastases, and poor overall survival of GC patients. Hsa_circ_0081143 inhibition decreased GC cells viability, invasion ability and induced the sensitivity of GC cells to cisplatin (DDP) in vitro. Mechanistically, we showed that hsa_circ_0081143 could act as an endogenous sponge by directly binding to miR-646 and downregulation of miR-646 efficiently reversed the inhibition of CDK6 induced by hsa_circ_008114 knockdown. Additionally, hsa_circ_0081143 silencing suppressed the tumorigenesis and remarkably enhance DDP inhibitory effects of GC cells in vivo. Conclusions Our study indicated a novel regulatory loop that hsa_circ_0081143/miR-646/CDK6 axis in GC progression. These data suggested that hsa_circ_0081143 might act as a potential novel therapeutic strategy for GC treatment

    Ginsenoside Rb1 Improves Cognitive Impairment Induced by Insulin Resistance through Cdk5/p35-NMDAR-IDE Pathway

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    The relationship between diabetes mellitus (DM) and Alzheimer’s disease (AD) has attracted wide attention. Studies have reported that ginsenoside Rb1 can improve human cognitive ability and glucose tolerance during the development of diabetes. The mechanism behind the improvement in cognitive ability and glucose tolerance still remains unclear. In this study, streptozotocin- (STZ-) injected mice were used as models to explore the mechanisms behind the cognitive improvement of ginsenoside Rb1. According to the results of behavioral tests, ginsenoside Rb1 improved memory and cognitive ability of STZ-lesioned mice. In addition to that, ginsenoside Rb1 also relieved glucose intolerance induced by STZ injection by enhancing insulin sensitivity. These beneficial effects of ginsenoside Rb1 is most likely mediated by upregulating the expression of NMDAR1 and IDE in the hippocampus through inhibiting the activity of Cdk5/p35. This work will be of great importance in illustrating the mechanisms of ginsenoside Rb1 for improving cognitive ability, as well as revealing the relationship between diabetes and AD
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