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BACKGROUND: Myocardial injury after non-cardiac surgery (MINS) is a common and insidious postoperative complication. This study aimed to evaluate the relationship between the triglyceride-glucose index (TyG) and MINS in advanced-age patients. METHODS: We performed a single-center retrospective study including patients ≥ 65 years of age who underwent non-cardiac surgery. The relationship between TyG and MINS was investigated using univariate and multivariate logistic regression analyses. Multivariate logistic regression analysis involved three models: Model I adjusted for preoperative factors, Model II adjusted for surgery-related factors, and Model III adjusted for both preoperative and surgery-related factors. Propensity score matching (PSM) was used to reduce the confounding effects of covariates. Subgroup analyses were then performed to evaluate the relationship between TyG and MINS in various subsamples. RESULTS: A total of 7789 patients were studied, among whom 481 (6.2%) developed MINS. A cut-off value of TyG of 8.57 was determined using a receiver operating characteristic (ROC) curve to be associated with the best predictive performance. Participants with TyG ≥ 8.57 were at a higher risk of developing MINS than those with TyG < 8.57 [n = 273 (7.6%) vs. n = 208 (4.9%), respectively; p < 0.001]. The univariate analysis showed that TyG ≥ 8.57 was significantly associated with MINS in elderly patients [odds ratio (OR): 1.58; 95% confidence interval (95%CI): 1.32-1.91; p < 0.001)]. In multivariate logistic regression, adjustments were made for risk factors including age, sex, body mass index (BMI), hypertension, coronary heart disease, and duration of surgery, etc. The adjusted ORs for TyG ≥ 8.57 were 1.46 (95%CI: 1.17-1.82), p = 0.001; 1.46 (95%CI: 1.19-1.77), p < 0.001; and 1.43 (95%CI: 1.13-1.81), p = 0.003, in the three multivariate models, respectively. The relationship remained after PSM (adjusted OR: 1.35, 95% CI: 1.03-1.78, p = 0.029). Furthermore, the relationship between TyG and MINS remained in a number of subgroups in the sensitivity analyses, but not in participants with peripheral vascular stenosis. CONCLUSIONS: A preoperative high TyG (≥ 8.57) is associated with a higher risk of MINS in advanced-age patients undergoing non-cardiac surgery.
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N2-hydraulic compound fracturing (NHCF) is an innovative technology aimed at addressing coalbed methane development challenges in low-permeability, low-pressure coal reservoirs in China. However, limited research has been focused on the evolution of damage zones, pore pressure fields, and fluid pressure characteristics in this context. In this paper, we establish a finite element seepage equation based on the volumetric opening model and construct a finite element model for horizontal well stage fracturing. We used the physical and mechanical parameters specific to coal reservoirs in the Xinjing coal mine. Subsequently, we conducted numerical simulations of N2 fracturing (NF), hydraulic fracturing (HF), and NHCF using ANSYS. The results indicate that the initiation-fracturing pressure of NHCF is lower than that of HF but higher than NF, but the steady-fracturing pressure is higher than HF and NF. Moreover, numerical simulation shows that under the same water injection volume, the total volumetric opening formed by NHCF is about 2 times that of HF, NF is the smallest, and the damage zone and pore pressure field caused by NHCF are the largest. Finally, when comparing the casing pressure curve of NHCF by field test with the fluid pressure curve of wellbore obtained from numerical simulation, we observe a strong correlation; the steady fracturing pressure of NF is about 13 MPa, which is basically consistent with the numerical simulation, and the steady- fracturing pressure of HF after NF is about 27 MPa, which is slightly lower than the 30 MPa in numerical simulation. This is because in the numerical simulation, the reservoir parameters after NF can be inherited to the subsequent HF, which cannot be done in the field test. This study presents a novel method for numerical fluid fracturing simulation, offering a fresh perspective on the subject.
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Several studies have revealed that results of the TNO stereo test may overestimate the stereoacuity value (the less the better) compared with other testing measurements. The manner in which vision is divided among two eyes of a person wearing anaglyph glasses may play an important role. This study aimed to examine the effect of anaglyph glasses on stereopsis measurements. A stereopsis measurement system using a phoropter and two Sony smartphones was established. Four types of test patterns, including the original TNO stereo test pictures, isoluminant red-green pictures, grayscale pictures, and black and white dots pictures, were designed. A total of 32 participants were recruited for this study. A significant difference was found among the four groups (Friedman test, chi-square = 50.985, P < 0.001). The Wilcoxon signed-rank test was used to detect differences between the groups. The stereoacuity of the original TNO group was significantly worse than those of the isoluminant, grayscale, and black-white groups. However, no significant difference was found between the isoluminant and grayscale groups. The correlation coefficient between the original TNO and isoluminant groups was 0.952 (Spearman's rho, P < 0.001; 95% confidence interval (CI), 0.901-0.988), while that between the original and grayscale groups was 0.771 (Spearman's rho, P < 0.001; 95% CI, 0.550-0.916). Anaglyph glasses played an important role in determining the stereoacuity values with the TNO stereo test, and the results were overestimated when compared with that of the other testing methods. The imbalance of chroma and luminance between the two eyes caused by the anaglyph glasses was indicated as one of the reasons for the overestimation of stereo thresholds.
