61 research outputs found

    Effect of miller cycle and fuel injection strategy on performance of marine diesel engine

    Get PDF
    Computational fluid dynamics (CFD) is used to investigate the performance of a large two-stroke marine diesel engine. The simulated model is validated with experimental data. The in-cylinder pressure of the simulated model is in agreement with the experimental data. The errors of NOx and CO2 emissions are also within the accepted range. The effect of Miller cycle, injection sequence and pilot injection on combustion and emissions are investigated using this model. The results show that the in-cylinder pressure decreases with deeper Miller cycle level. However, NOx emissions are reduced only slightly to 8.95 g/kWh. This decrease in NOx emissions does not satisfy the requirements of Tier III. We also found that the injection interval angle between two injectors decreases the combustion pressure. However, the indicated specific fuel consumption is 7.3 g/kWh higher than the base value, when the injection interval angle is 8 °CA. Appropriate pilot injection strategy can decrease NOx emissions and indicated specific fuel consumption, such as P10I5. However, NOx emissions are not reduced sufficiently to meet the requirements of Tier III

    Effects of Different Exogenous Substances on the Protein Conformation and in Vitro Digestion Characteristics of Low-salt Tilapia Surimi

    Get PDF
    The effects of glutamine transaminase (TGase), hydroxypropyl distarch phosphate (HDP), gellan gum and their complex (THG) on the water distribution and protein conformation of low-salt tilapia surimi gel prepared with microwave and ultrasound were analyzed. In addition, the effects of different exogenous substances on the characteristics of low-salt tilapia fish cake were explored through in vitro digestion experiment. The results showed that compared with the control group, THG increased the bound water and immovable water of surimi to 98.71% and 14.75%, respectively, and significantly decreased the free water content (P<0.05). Moreover, THG promoted the transformation of α-helix to ÎČ-folding, ÎČ-turning and random curling structures. TGase and THG (0.4%) played important roles on gastric emptying rate, protein digestibility and protein hydrolysis degree of low-salt tilapia cake. THG significantly promoted protein decomposition into aggregates with smaller particle size (P<0.05). After the digestion of stomach and duodenum, color of the THG group products was more transparent and clear. And it could be observed by the laser confocal microscope that the red fluorescence highlights of the THG group were significantly reduced, indicating that proteins had been fully digested. Hence, compared with a single exogenous substance, THG not only promoted the binding of water molecules and proteins and induced the change of protein conformation, but also facilitated the exposure of hydrophobic protein groups and the interaction between proteins, and promoted the digestion and absorption of surimi products in the stomach and duodenum. This project provided a theoretical reference for the research on the gel properties of tilapia surimi and the development and application of tilapia fish cake

    HSPA12A Unstabilizes CD147 to Inhibit Lactate Export and Migration in Human Renal Cell Carcinoma

    Get PDF
    This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). See http://ivyspring.com/terms for full terms and conditions. Background: Metastasis accounts for 90% of cancer-associated mortality in patients with renal cell carcinoma (RCC). However, the clinical management of RCC metastasis is challenging. Lactate export is known to play an important role in cancer cell migration. This study investigated the role of heat shock protein A12A (HSPA12A) in RCC migration. Methods: HSPA12A expression was examined in 82 pairs of matched RCC tumors and corresponding normal kidney tissues from patients by immunoblotting and immunofluorescence analyses. The proliferation of RCC cells was analyzed using MTT and EdU incorporation assays. The migration of RCC cells was evaluated by wound healing and Transwell migration assays. Extracellular acidification was examined using Seahorse technology. Protein stability was determined following treatment with protein synthesis inhibitor cycloheximide and proteasome inhibitor MG132. Mass spectrometry, immunoprecipitation, and immunoblotting were employed to examine protein-protein interactions. Results: RCC tumors from patients showed downregulation of HSPA12A, which was associated with advanced tumor node metastasis stage. Intriguingly, overexpression of HSPA12A in RCC cells inhibited migration, whereas HSPA12A knockdown had the opposite effect. Lactate export, glycolysis rate, and CD147 protein abundance were also inhibited by HSPA12A overexpression but promoted by HSPA12A knockdown. An interaction of HSPA12A with HRD1 ubiquitin E3 ligase was detected in RCC cells. Further studies demonstrated that CD147 ubiquitination and proteasomal degradation were promoted by HSPA12A overexpression whereas inhibited by HSPA12A knockdown. Notably, the HSPA12A overexpression-induced inhibition of lactate export and migration were abolished by CD147 overexpression. Conclusion: Human RCC shows downregulation of HSPA12A. Overexpression of HSPA12A in RCC cells unstabilizes CD147 through increasing its ubiquitin-proteasome degradation, thereby inhibits lactate export and glycolysis, and ultimately suppresses RCC cell migration. Our results demonstrate that overexpression of HSPA12A might represent a viable strategy for managing RCC metastasis

    Hybridization modeling of oligonucleotide SNP arrays for accurate DNA copy number estimation

    Get PDF
    Affymetrix SNP arrays have been widely used for single-nucleotide polymorphism (SNP) genotype calling and DNA copy number variation inference. Although numerous methods have achieved high accuracy in these fields, most studies have paid little attention to the modeling of hybridization of probes to off-target allele sequences, which can affect the accuracy greatly. In this study, we address this issue and demonstrate that hybridization with mismatch nucleotides (HWMMN) occurs in all SNP probe-sets and has a critical effect on the estimation of allelic concentrations (ACs). We study sequence binding through binding free energy and then binding affinity, and develop a probe intensity composite representation (PICR) model. The PICR model allows the estimation of ACs at a given SNP through statistical regression. Furthermore, we demonstrate with cell-line data of known true copy numbers that the PICR model can achieve reasonable accuracy in copy number estimation at a single SNP locus, by using the ratio of the estimated AC of each sample to that of the reference sample, and can reveal subtle genotype structure of SNPs at abnormal loci. We also demonstrate with HapMap data that the PICR model yields accurate SNP genotype calls consistently across samples, laboratories and even across array platforms

    Nonstandard Errors

    Get PDF
    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Non-Standard Errors

    Get PDF
    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Development of a Three-Phase Sequential Turbocharging System with Two Unequal-Size Turbochargers

    Get PDF
    A three-phase sequential turbocharging system with two unequal-size turbochargers is developed to improve the fuel economy performance and reduce the smoke emission of the automotive diesel engine, and it has wider range of application than the current two-phase sequential turbocharging system. The steady matching method of the turbochargers and engine and the steady switching boundary are presented. The experimental results show that this system is effective to improve the engine performance especially at the low speed and high load. The maximum reductions of BSFC and smoke opacity are 7.1% and 70.9%. The optimized switching strategies of the valves are investigated, and the surge of the compressor in the switching process is avoided. The switching strategies in the accelerating process are optimized, and the acceleration time from 900 r/min and 2100 r/min at constant torque is reduced by approximately 20%

    Design and simulation of fault diagnosis based on NUIO/LMI for satellite attitude control systems

    No full text

    A Procedure for Estimating the Number of Clusters in Logistic Regression Clustering

    No full text
    Asymptotics, Logistic regression clustering, Model selection, Penalty,

    Trends of a decade in risk factors of patient delay among pulmonary tuberculosis patients during fast aging and urbanization - analysis of surveillance data from 2008 to 2017 in Wuhan, China

    No full text
    Abstract Background Tuberculosis (TB) is a leading infectious cause of morbidity and mortality worldwide. However, delay in health care seeking has remained unacceptably high. The aim of this study was to clarify the trend of patient delay and its associated risk factors during rapid aging and urbanization in Wuhan, China from 2008 to 2017. Methods A total of 63,720 TB patients registered at Wuhan TB Information Management System from January 2008 to December 2017 were included. Long patient delay (LPD) was defined as patient delay longer than 14 days. Independent associations of area and household identity with LPD, as well their interaction effect, were tested by logistic regression models. Results Among 63,720 pulmonary TB patients, 71.3% were males, the mean age was 45.5 ± 18.8 years. The median patient delay was 10 days (IQR, 3–28). A total of 26,360 (41.3%) patients delayed for more than 14 days. The proportion of LPD decreased from 44.8% in 2008 to 38.3% in 2017. Similar trends were observed in all the subgroups by gender, age and household, except for living area. The proportion of LPD decreased from 46.3 to 32.8% in patients living near downtown and increased from 43.2 to 45.2% in patients living far from downtown. Further interaction effect analysis showed that among patients living far from downtown, the risk of LPD for local patients increased with age, while decreased with age for migrant patients. Conclusion Although the overall LPD among pulmonary TB patients declined in the past decade, the extent of reduction varied in different subgroups. The elderly local and young migrant patients living far from downtown are the most vulnerable groups to LPD in Wuhan, China
    • 

    corecore