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In order to understand the physiological mechanism of drought stress affecting premature leaf senescence of the pod subtending leaf during flowering and pod period, a pot experiment was conducted in Hefei, Anhui Province from 2021 to 2022. The effects of drought stress on the endogenous protective enzyme system and ascorbate glutathione cycle were studied based on the antioxidant metabolism system at soil water content (SWC) (75 ± 5)%, (60 ± 5)% and (45 ± 5)% on two soybean varieties (Wandou 37, drought weak sensitive variety; Wandou 38, drought sensitive variety). The results revealed that drought accelerated the senescence of pod subtending leaf, with SPAD decreasing by 8.0%-24.2% for Wandou 37 and by 12.4%-32.9% for Wandou 38. The activities of superoxide dismutase (SOD) and peroxidase (POD) and the content of ascorbic acid (ASA) were significantly increased in the pod subtending leaf, however the activities of ascorbate oxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were inhibited by drought stress. A large amount of H2O2 and O2- could not be completely removed, resulting in the increase of H2O2 and MDA content, and the increase of O2- production rate, which resulted in acceleration of leaf senescence. SWC (45 ± 5)% treatment was significantly higher than SWC (60 ± 5)% treatment, and the results were consistent between the two varieties. Compared with Wandou 38, Wandou 37 had higher GR and PAX activities under drought stress, increased ASA content, reduced H2O2 and O2- accumulation, and reduced the degree of membrane lipid peroxidation. Therefore it improved the resistance to drought adversity. [ABSTRACT FROM AUTHOR]

Background: The impact of left ventricular mechanical dyssynchrony (LVMD) on the long‐term prognosis of ST‐segment elevation myocardial infarction (STEMI) is unclear. Hypothesis: MR uniformity ratio estimates (URE) can detect LVMD and assess STEMI prognosis. Study Type: Retrospective analysis of a prospective multicenter registry (EARLY‐MYO trial, NCT 03768453). Population: Overall, 450 patients (50 females) with first‐time STEMI were analyzed, as well as 40 participants without cardiovascular disease as controls. Field Strength/Sequence: 3.0‐T, balanced steady‐state free precession cine and late gadolinium enhancement imaging. Assessment: MRI data were acquired within 1 week of symptom onset. Major adverse cardiovascular events (MACEs), including cardiovascular death, nonfatal re‐infarction, hospitalization for heart failure, and stroke, were the primary clinical outcomes. LVMD was represented by circumferential URE (CURE) and radial URE (RURE) calculated using strain measurements. The patients were grouped according to clinical outcomes or URE values. Patients' clinical characteristics and MR indicators were compared. Statistical Tests: The Student's t‐test, Mann–Whitney U test, chi‐square test, Fisher's exact test, receiver operating characteristic curve analysis with area under the curve, Kaplan–Meier analysis, Cox regression, logistic regression, intraclass correlation coefficient, c‐index, and integrated discrimination improvement were used. P < 0.05 was considered statistically significant. Results: CURE and RURE were significantly lower in patients with STEMI than in controls. The median follow‐up was 60.5 months. Patients with both lower CURE and RURE values experienced a significantly higher incidence of MACEs by 3.525‐fold. Both CURE and RURE were independent risk factors for MACEs. The addition of UREs improved diagnostic efficacy and risk stratification based on infarct size and left ventricular ejection fraction (LVEF). The indicators associated with LVMD included male sex, serum biomarkers (peak creatine phosphokinase and cardiac troponin I), infarct size, and LVEF. Data Conclusion: CURE and RURE may be useful to evaluate long‐term prognosis after STEMI. Evidence Level: 4 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Background: The impact of concomitant impairments of left and right ventricular (LV and RV) strain on the long-term prognosis of acute ST-elevation myocardial infarction (STEMI) is not clear.Methods: We analyzed CMR images and followed up 420 first STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453). These patients received timely primary percutaneous coronary intervention (PCI) within 12 h and CMR examination within 1 week (median, 5 days; range, 2–7 days) after infarction. Global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) of both ventricles were measured based on CMR cine images. Conventional CMR indexes were also assessed. Primary clinical outcome was composite major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, re-hospitalization for heart failure and stroke. In addition, CMR data from 40 people without apparent heart disease were used as control group.Results: Compared to controls, both LV and RV strains were remarkably reduced in STEMI patients. During follow-up (median: 52 months, interquartile range: 29–68 months), 80 patients experienced major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, heart failure, and stroke. LV-GCS > −11.20% was an independent predictor of MACCEs (P < 0.001). RV-GRS was the only RV strain index that could effectively predict the risk of MACCEs (AUC = 0.604, 95% CI [0.533, 0.674], P = 0.004). Patient with RV-GRS ≤ 38.79% experienced more MACCEs than those with preserved RV-GRS (log rank P < 0.001). Moreover, patients with the concomitant decrease of LV-GCS and RV-GRS were more likely to experience MACCEs than patients with decreased LV-GCS alone (log rank P = 0.010). RV-GRS was incremental to LV-GCS for the predictive power of MACCEs (continuous NRI: 0.327; 95% CI: 0.095–0.558; P = 0.006). Finally, tobacco use (P = 0.003), right coronary artery involvement (P = 0.002), and LV-GCS > −11.20% (P = 0.012) was correlated with lower RV-GRS.Conclusions: The concomitant decrease of LV and RV strain is associated with a worse long-term prognosis than impaired LV strain alone. Combination assessment of both LV and RV strain indexes could improve risk stratification of patients with STEMI.Trial Registration:ClinicalTrials.gov, NCT03768453. Registered 7 December 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03768453.