Ultra-compact VCSEL scanner for high power solid-state beam steering.

We demonstrate the lateral monolithic integration of a tunable first-order surface-grating loaded vertical-cavity surface-emitting laser (VCSEL) and slow-light waveguide with fan-beam steering and amplifier function. Shallow Bragg-grating formed on the surface of a VCSEL section enables the selection of a single slow-light mode, which can be coupled into the integrated long waveguide and amplified through pumping the amplifier above threshold. We obtained over 3W amplified slow-light power with single-mode operation and over 4W amplified quasi-single-mode power under pulsed current injection. To the best of our knowledge, this is the highest output power for single-mode VCSELs. Solid-state beam steering of the device is also demonstrated with 9° fan-beam steering range and 200 resolution points.

Evaluation of left ventricular systolic function in patients with systemic lupus erythematosus using ultrasonic layer-specific strain technology and its association with cardiovascular events: a long-term follow-up study.

BACKGROUND: Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease with potential cardiovascular involvement. Layer-specific strain (LSS) analysis is a new method that allows early detection of subtle left ventricular (LV) systolic dysfunction. The aim of this study was to evaluate LV systolic function in patients with SLE using conventional echocardiographic measurements and longitudinal strain (LS) and circumferential strain (CS) by LSS. Furthermore, the association between echocardiographic parameters and the occurrence of cardiovascular events was assessed. METHODS: A total of 162 patients with SLE (the SLE group) who underwent a dedicated multidisciplinary assessment, including echocardiography, were analyzed at the time of their first visits. The control group consisted of 68 age- and sex-matched healthy subjects. LS and CS on endocardial, mid-myocardial, and epicardial layers at 17 cardiac segments were measured. Transmural strain gradient was calculated as the differences in systolic strain between the endocardial and epicardial layers. RESULTS: Compared with control subjects, patients with SLE had significantly lower LV ejection fraction, LS, and CS values in all layers (P < 0.05); LV LS and CS gradient were all lower than control subjects (P < 0.05). During a median follow-up period of 83 months (interquartile range: 64-95 months), 59 patients (36.4%) developed cardiovascular events. Using multivariate Cox regression analysis, we found that LV endocardial LS (hazard ratio, 1.014; 95% CI, 1.002-1.035; P = 0.025) and CS (hazard ratio, 1.051; 95% CI, 1.027-1.077; P < 0.001) demonstrated independent associations with cardiovascular events; whereas LV ejection fraction was not significantly associated with cardiovascular events. The Kaplan-Meier survival curves showed that patients with SLE with lower LV endocardial LS and CS (based on the cutoff values of -21.5% and -29.0%, respectively) experienced higher cumulative rates of cardiovascular events compared with those with higher LV endocardial LS and CS. CONCLUSIONS: In patients with SLE, LV systolic function measured by LV endocardial LS and CS were significantly lower than that of the control group and were associated with cardiovascular events, potentially representing a new technology to improve risk stratification in these patients.

Assessment of right ventricular structure and systolic function in amateur marathon runners using three-dimensional speckle tracking echocardiography.

Prolonged high-intensity endurance exercise has been reported to have adverse effects on the heart, which are further correlated with exercise dose. However, its effect on the right ventricle (RV) of amateur runners is unknown. This study aimed was to evaluate the early right ventricular structure and systolic function of amateur marathon runners by three-dimensional speckle tracking echocardiography (3D-STE), and to further analyze the correlation between relevant parameters and the amount of training. A total of 30 amateur marathon runners (marathon group) and 27 healthy volunteers (control group) were enrolled. Conventional echocardiography combined with 3D-STE was performed in all subjects, and the marathon group was screened by echocardiography a week before a marathon (V1), within 1 h post-marathon (V2), and 4 days post-marathon (V3). RV global longitudinal strain (GLS) and RV end-diastolic volume (EDV) increased significantly in the marathon group compared to the control group (P < 0.05). RV GLS was significantly decreased in the marathon group within 1 h post-marathon (V1: - 26.2 ± 2.5% vs V2: - 23.0 ± 1.6% vs V3: - 25.6 ± 2.6%, P < 0.001). However, there was no significant difference in RV ejection fraction (RVEF) (P > 0.05). The results of the correlation analysis showed that RV EDV and RV end-systolic volume (ESV) were positively correlated with the average training volume (P < 0.001). Multivariate linear regression analysis showed that average training volume was an independent predictor of RV EDV in amateur marathoners (ß = 0.642, P < 0.001). The systolic function of the RV was enhanced in amateur marathon runners in the early stage, manifested by an increase in RV EDV. After a long period of high-intensity endurance exercise, RV systolic function will temporarily be reduced. 3D-STE can identify this subclinical change with high sensitivity and provide valuable information to assess the structure and function of RV in amateur marathon runners.