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Existing obesity- and lipid-related indices are inconsistent with metabolic syndrome (MetS) in chronic kidney disease (CKD) patients. We compared seven indicators, including waist circumference (WC), body mass index (BMI), visceral fat area (VFA), subcutaneous fat area (SFA), visceral adiposity index (VAI), Chinese VAI and lipid accumulation product (LAP), to evaluate their ability to predict MetS in CKD patients with and without Type 2 diabetes mellitus (T2DM) under various criteria. Multivariate logistic regression analysis was used to investigate the independent associations between the indices and metabolic syndrome among 547 non-dialysis CKD patients, aged ≥18 years. The predictive power of these indices was assessed using receiver operating characteristic (ROC) curve analysis. After adjusting for potential confounders, the correlation between VAI and MetS was strongest based on the optimal cut-off value of 1.51 (sensitivity 86.84%, specificity 91.18%) and 2.35 (sensitivity 83.54%, specificity 86.08%), with OR values of 40.585 (8.683–189.695) and 5.076 (1.247–20.657) for males and females with CKD and T2DM. In CKD patients without T2DM, based on the optimal cut-off values of 1.806 (sensitivity 98.11%, specificity 72.73%) and 3.11 (sensitivity 84.62%, specificity 83.82%), the OR values were 7.514 (3.757–15.027) and 3.008 (1.789–5.056) for males and females, respectively. The area under ROC curve (AUC) and Youden index of VAI were the highest among the seven indexes, indicating its superiority in predicting MetS in both male and female CKD patients, especially those with T2DM.

Objective. It is not clear which Traditional Chinese Medicine- (TCM-) related elements affect primary IgA nephropathy (IgAN) progression. Here, we explored the risk factors, based on TCM syndrome elements, related to the prognosis of primary IgAN patients. Methods. We analyzed patients with newly diagnosed, biopsy-proven IgAN at a single institution from December 2013 to September 2021. Basic clinical and pathological characteristics were assessed at the time of renal biopsy. The study endpoint was end-stage renal disease (ESRD: eGFR 30% from baseline. Kaplan‒Meier survival analysis was used to explore the role of TCM syndrome elements in IgAN progression. Multivariate Cox regression analysis with adjustment for traditional risk factors was performed to explore TCM syndrome elements that may influence patient prognosis. The factors correlated with TCM syndrome elements in IgAN patients were further evaluated by logistic regression analysis. Results. During a median follow-up of 22.0 months, 53 (12.5%) of the 423 included IgAN patients reached the study endpoint. The main IgAN disease location elements were the kidney, liver, and spleen. The main IgAN disease nature elements were Yin-deficiency and Qi-deficiency, dampness, Yang-deficiency, phlegm, and Blood-deficiency. Kaplan‒Meier analysis identified three disease locations (liver, spleen, and kidney) and four disease natures (Qi-deficiency, Yang-deficiency, phlegm, and dampness) as elements associated with poor renal survival in IgAN patients. In multivariate Cox regression analysis, baseline Yang-deficiency was an independent risk predictor of poor prognosis in primary IgAN patients (hazard ratio 2.338; 95% confidence interval [CI]: 1.208–4.525; P = 0.012 ) after adjustment for traditional risk factors. Furthermore, logistic regression analysis identified being female (odds ratio [OR] 2.518; 95% CI: 1.538–4.122; P < 0.001 ), older age (OR 1.043; 95% CI: 1.022–1.065; P < 0.001 ), low hemoglobin levels (OR 0.984; 95% CI: 0.971–0.996; P = 0.013 ), and cellular/fibrocellular crescents (OR 1.706; 95% CI: 1.068–2.728; P = 0.026 ) as factors affecting Yang-deficiency in IgAN patients. Conclusions. Yang-deficiency independently predicts the risk of poor prognosis in primary IgAN patients. Being female, older age, low hemoglobin levels, and cellular/fibrocellular crescents were independently associated with Yang-deficiency in IgAN patients.

Reynolds-averaged Navier–Stokes and hybrid large-eddy/Reynolds-averaged Navier–Stokes simulations of turbulent flow past an Aerospatiale A-Airfoil near stall at Rec=2.1×106, M=0.15, α=13.3 and a NA...

Numerical simulations by finite volume method were performed to investigate the freezing process and growing up of ice ball by embedding a cryo-probe either into a glass tank full of water or biological tissues with and without a tumor. For water tank cases, numerical results of ice-ball size and the temperature history of the ice ball during the freezing process are in good agreement with the experimental measurements as long as the convective heat coefficient is reasonably chosen. In biological tissue cases, numerical simulations performed based on various vascular models indicate the effects of the existence of large blood vessels are not negligible.

This paper briefly reviews recent and current National Institute of Standards and Technology (NIST) research aimed at improving standard provisions and advancing structural design practice for wind loads. The research covers: (i) New wind speed maps for the conterminous United States; (ii) Risk-consistent estimation of wind load factors for use with the wind tunnel procedure; (iii) Modern peaks-over-threshold approaches to estimation of peak wind effects; (iv) User-friendly procedures for the database-assisted design of rigid and flexible structures; (v) Novel approaches to codification of pressures on cladding and components; (vi) Modern modeling of synoptic storm planetary boundary layers and its implications for super-tall building design; (vii) Computational Wind Engineering (CWE); (viii) Tornado climatology and development of tornado-resistant design methodologies; (ix) Joint climatology of wind speeds, storm surge and waves heights, and estimates of their combined effects on structures.

In this work, the effect of experimental parameters on the error levels associated with simultaneous measurement of displacement and temperature using Molecular Tagging Velocimetry/Thermometry (MTV/T) was quantified via simulated images. Images were simulated using Gaussian profile laser lines. Noise was added to the images using a uniform random distribution and a Gaussian random distribution to simulate electronic noise and shot noise, respectively. The results showed that the error levels in the displacement and temperature measurements were inversely related for most experimental parameters including the laser line thickness, fluid temperature and image delay times. It is concluded that the dynamic range of the technique depends on the flow speeds and temperatures and must be determined for each experiment individually. Error levels, for 95% confidence, were found to be better than 0.3°C for temperature and 0.2 pixels for displacement for typical real-world experimental parameters.

The hybrid Large-Eddy/Reynolds-Averaged Navier-Stokes (LES/RANS) and RANS simulations are used to investigate the properties of subsonic flow over NACA 0012 airfoils undergoing static and dynamic stall conditions (M=0.1, α=16.7°, Rec=1.0×10 6 ). In the simulations of NACA 0012 airfoil at static stall case, Menter’s SST model predicts an attached flow at the leading edge, whereas the Gieseking’s LES/RANS model on a coarser mesh predicts a massively separated flow characterized by the stabilization of a detached leading edge vortex near the trailing edge. The predictions by Gieseking’s model on a coarse mesh agree closely with PIV measurements of mean velocity, the Reynolds axial stress and the Reynolds normal stress, but over-predict the magnitude of the Reynolds shear stress. However, Gieseking’s model on a fine mesh predicts a more attached flow because the under-resolved LES on the fine mesh (but not fine enough as required in a wall-resolved LES) fails to reproduce the cascade process at the smaller scale and results in an overlyenergetic boundary layer near leading edge which resists and delays the separation. In 3D simulations of dynamic stall case where the NACA 0012 airfoil is dynamically pitching about its quarter-chord at a reduced frequency, kr=0.1, Gieseking’s model on a coarse mesh in spanwise direction correctly predicts response of the massive separation at static stall angle of 16.7° during downstroke pitching, but it also predicts some leading edge separation which is not present in the experiment during upstroke pitching. Mesh refinement in the spanwise direction helps reducing the level of leading edge separation during upstroke pitching, but results in an under-separated flow solution for downstroke response, which is consistent with what happens in the static stall case and the reason is also similar. By introducing a grid correction function in the definition of outer layer turbulence length scale, Salazar’s fix takes grid resolution into consideration while determining the RANS to LES transition. The inclusion of Salazar’s fix to Gieseking’s model delays the leading edge separation during upstroke pitching, but it also introduces a too-attached flow for downstroke response.

This work presents results from Reynolds-averaged Navier-Stokes and hybrid Largeeddy/Reynolds-averaged Navier-Stokes (LES/RANS) simulations of two flow cases: a turbulent flow past an Aerospatiale A-Airfoil near stall at a chord Reynolds number, ( , , ), and a flow past NACA 0012 airfoil under static and dynamic stall conditions ( , , ). In the flow past the A-Airfoil, the suction side boundary layer is complex: it includes a laminar separation bubble by an adverse pressure gradient, a turbulent reattachment and a turbulent separation near trailing edge. Comparisons with surface skin-friction coefficient and pressure coefficient distribution are generally in good agreement with experimental measurements. Comparisons with experimental velocity profile data and Reynolds-stress data are also generally favorable. Leading-edge laminar separation and turbulent reattachment is predicted when the Menter-Langtry correlation-based transition model is used in combination with either RANS or LES/RANS strategies, but the level of trailing-edge separated is under-predicted, relative to experimental data and to results obtained without the transition model. In the flow past NACA 0012 airfoil case, the airfoil was dynamically pitched about its quarter-chord at a reduced frequency, . Computational results from RANS simulations show that the flow remains attached in the leading edge region above the static stall angle during upstroke, whereas it remains separated below the static stall angle during downstroke. These results match the experimental measurement well. For static stall case of flow past NACA 0012 airfoil, results from the LES/RANS simulation are in much better agreement with the experimental data compared with those from RANS simulations. The RANS models predict flow attachment at the leading edge, whereas the LES/RANS model predicts leading edge flow separation, with the leading-edge vortex stabilized upstream of the trailing edge.

Leading edge vortex (LEV) formation, which is initiated by separation at the leading edge, depends on airfoil shape, Reynolds number, rate of translation/rotation, amplitude of motion and the pitch axis location. The Leading Edge Suction Parameter (LESP) derived from inviscid theory, serves to predict the onset LEV formation for any unsteady motion using a critical value that depends on the airfoil shape and Reynolds number of operation. In this paper, the critical LESP value is determined for different airfoils over a range of Reynolds numbers. The SD7003 airfoil was used as a baseline and modified airfoils were derived by altering the leading edge radius, keeping maximum thickness unchanged. Increasing the leading edge radius resulted in higher critical LESP values, demonstrating that separation is delayed for flow over a more rounded leading edge since it can support more suction. The effect of Reynolds number was more complicated, with the critical LESP decreasing from Re = 5,000 to Re = 100,000, and increasing after. Hence conditions which promote and suppress leading edge vortex formation were identified, and the critical LESP values were made available over a broad range of parameters, which can be used for low-order prediction and modeling of complicated, vortex-dominated flows.