Improving optical coherence of light-emitting diodes by surface plasmons via shallow-etched conic pit array.

We propose the coupling of multiple quantum wells and surface plasmons can improve coherence of light emitted from LED wafers, as evidenced herein by a shallow-etched conic pit array with evaporated Ag (V-Ag) on a GaN-based LED wafer. The improvement in spatial coherence is critically verified by angle-resolved spectra. The temporal coherence length of the V-Ag wafer is 1.4 times larger than that of the plain wafer. The coherence-enhanced wafer achieves anisotropic and deflective emission in micro area and at far field by diffraction. This research provides a novel perspective on research of plasmonic LEDs and a new straightforward architecture to acquire partially coherent light from LEDs.

Enhanced coupling efficiency and electrical property in surface plasmon-enhanced light-emitting diodes with the tapered Ag structure.

We design, fabricate and analyze plasmon-enhanced LEDs with the tapered Ag structure that significantly increases plasmonic coupling efficiency at a coupling distance far beyond the penetration depth. The electroluminescence intensity showed a 16-fold increase compared with planar LEDs with a coupling distance of 100 nm. The enhanced coupling efficiency with large distance is originated from the accumulated SP energy at the metal conical tip and the missing momentum provided by the corrugated surface. Therefore, the SP-enhanced LED with tapered Ag structure can maintain a high luminous efficiency and a stable working state even with thick p-GaN layer, which also guarantees a high electrical performance. Our study paves the way for a practical implementation of SP-enhanced LEDs with excellent optical and electrical properties.

Serum VEGF: Diagnostic Value of Acute Coronary Syndrome from Stable Angina Pectoris and Prognostic Value of Coronary Artery Disease.

BACKGROUND: Although the level of serum vascular endothelial growth factor (VEGF) is elevated in coronary artery disease (CAD) patients, its potential role in acute coronary syndrome (ACS) or stable angina pectoris (SAP) patients remains unclear. OBJECTIVES: To evaluate diagnostic accuracy of serum VEGF in determining ACS patients from SAP and analyze the association of serum VEGF with coronary artery lesions in SAP or the GRACE score in ACS, which is involved in the poor prognosis of low serum VEGF. METHODS: 248 CAD patients and 48 healthy subjects were enrolled in this study. Serum VEGF levels were detected by using ELISA. The Gensini score or GRACE score was calculated among SAP or ACS patients. All the patients were followed up for a period of 12 months (mean: 10.77 months). RESULTS: VEGF serum concentrations were higher in the ACS subgroup than in the SAP subgroup (P < 0.001) with diagnostic accuracy of ACS from SAP (AUC: 0.667, sensitivity: 68.5%, specificity: 60.1%, P < 0.001). Patients with high risk of Gensini score showed reduced VEGF levels (P < 0.001) accompanied by a negative correlation (r = -0.396, P < 0.001). Patients with a higher GRACE score indicated lower VEGF levels (P < 0.001). Low serum VEGF was one of the potential risk factors with adjusted HR of 0.531 (P=0.048). CONCLUSION: Serum VEGF exhibits efficient diagnostic value for detection of ACS from SAP with a cutoff value of 648.75 pg/mL. Low serum VEGF indicates severe coronary artery lesions and a higher GRACE score, which suggests poor clinical outcomes.

Non-HDL-c/TC: A Novel Lipid-Related Marker in the Assessment of Severity of Coronary Artery Lesions and Cardiovascular Outcomes.

BACKGROUND: Non-high-density lipoprotein cholesterol (non-HDL-c) predicts the severity of coronary artery lesions in patients not treated with statin. The association between non-HDL-c and severity of coronary artery lesions in patients treated with lipid-lowering therapy has been unknown. HYPOTHESIS: We hypothesize a novel marker of non-HDL-c/TC predicts the severity of coronary artery lesions and clinical outcomes in 12 months in the patients treated with statin. METHOD: 473 subjects who met inclusion criteria were eligible for inclusion. Coronary artery angiography (CAG) was performed, and the Gensini score (GS) was calculated in all the subjects divided into three subgroups of low risk, medium risk, and high risk by the tertiles of GS. The non-HDL-c value was calculated as TC minus HDL-c, while non-HDL-c/TC was the ratio of non-HDL-c and TC. RESULTS: The concentration of non-LDL-c differed between non-obstructive-CAD group and obstructive-CAD group (P < 0.05), and non-HDL-c/TC was elevated in the obstructive-CAD group (P < 0.05). Increased GS was associated with increasing non-HDL-c/TC (P < 0.05). Non-HDL-c/TC (OR: 108.50, 95% CI: 1.57-7520.28; P=0.030) remained as an independent predicting factor of high risk under GS stratification. In unadjusted Cox model, high non-HDL-c/TC (RR: 1.976, 95% CI: 1.155-3.382; P=0.013) predicted the occurrence of adverse events. After multivariate adjustment, high non-HDL-c/TC (RR: 1.921, 95% CI: 1.105-3.339; P=0.021) was an independent predictor of poor outcomes. CONCLUSION: High level of non-HDL-c/TC presented an excellent prognostic value compared with other lipid-related markers in CAD patients treated with statin.