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Remnant cholesterol (RC) promotes cardiovascular disease (CVD) in the general population, but its role among rheumatoid arthritis (RA) patients remains unknown. We aimed to investigate circulating RC levels associated with incident CVD among Chinese patients with RA. A total of 1018 RA patients free of baseline CVD were included and followed up in a prospective RA CVD cohort from 2001 to 2022. Fasting serum levels of triglycerides, total cholesterol (TC), low-density (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured, while RC and Non-HDL-C levels were calculated. The primary exposure was RC levels. A LASSO Cox model was used to select covariates. The Fine-Gray competing risk model was used to estimate hazard ratios (HRs). RA patients had a mean age of 53.9 years, and 802 (78.8%) were females. After a median follow-up of 5.54 years, 131 patients developed CVD with an incidence rate of 21.6 per 1000 person-years. Continuous and quartile-categorized RC levels were associated with incident CVD before and after multivariate adjustment and Bonferroni correction (all P < 0.001). There were no robust associations of other lipids with incident CVD. The fully adjusted HRs for RC were 2.30 (95% CI 1.58–3.35) per 1 mmol/L increase, and 2.40 (1.36–4.25) and 2.81 (1.60–4.94) for patients in the 3rd and 4th versus the 1st quartile, respectively. Circulating RC levels are positively associated with incident CVD among Chinese RA patients independent of known risk factors, implying its clinically preferable use for improving the stratification of CVD risk in RA patients. • Evidence before this study: It has been generally accepted that RA had higher risk of CVD than general population, and CVD risk assessment is recommended for all RA patients. • Several studies have shown associations between elevated RC levels and increased risk of CVD in various general populations. • Added value of the study: This study established a longitudinally positive association of fasting serum levels of RC with incident CVD in RA patients and RC reflected the incident CVD risk of RA patients free of pre-existing CVD at baseline more robustly than other lipid indicators. • Implication of all the available evidence: This study showed that fasting serum levels of RC could be potential applied for risk stratification in the RA patients to identify the residual risk of CVD not captured by established markers. [ABSTRACT FROM AUTHOR]

The blade tip with conical holes is proposed in the current paper to improve the film cooling performance on the turbine blade tip. The film cooling performance of the blade tip with cylindrical holes is studied as a reference case. The pressure sensitive paint technique is adapted to obtain the tip film cooling effectiveness in transonic flow. The numerical simulation is used to obtain the tip flow field and aerodynamic loss. The cascade exit Mach number and inlet Reynolds number are 1.05 and 370000, respectively. The experiment and calculation are carried out at two tip clearance gaps of 0.7% and 1.5% and four mass-flow-ratios. The results show that at low mass flow ratios, the film cooling effectiveness of the blade tip with conical holes is significantly higher than that of the blade tip with cylindrical holes at the tip mid-chord region. Increasing the tip clearance gap from 0.7% to 1.5% shows a negative effect on the film cooling performance of the blade tip with conical holes in the tip mid-chord region, particularly for the low mass flow ratio. The pitch-wise averaged aerodynamic loss coefficient of the blade tip with cylindrical holes is lower than that of the blade tip with conical holes near the shroud. [ABSTRACT FROM AUTHOR]

The blade tip with conical holes is proposed in the current paper to improve the film cooling performance on the turbine blade tip. The film cooling performance of the blade tip with cylindrical holes is studied as a reference case. The pressure sensitive paint technique is adapted to obtain the tip film cooling effectiveness in transonic flow. The numerical simulation is used to obtain the tip flow field and aerodynamic loss. The cascade exit Mach number and inlet Reynolds number are 1.05 and 370000, respectively. The experiment and calculation are carried out at two tip clearance gaps of 0.7% and 1.5% and four mass-flow-ratios. The results show that at low mass flow ratios, the film cooling effectiveness of the blade tip with conical holes is significantly higher than that of the blade tip with cylindrical holes at the tip mid-chord region. Increasing the tip clearance gap from 0.7% to 1.5% shows a negative effect on the film cooling performance of the blade tip with conical holes in the tip mid-chord region, particularly for the low mass flow ratio. The pitch-wise averaged aerodynamic loss coefficient of the blade tip with cylindrical holes is lower than that of the blade tip with conical holes near the shroud. [ABSTRACT FROM AUTHOR]