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Corona textures, characterized by specific mineral assemblages as layers between existing phases, are frequently observed in high-grade metamorphic rocks. The mechanisms of corona formation have been extensively investigated, however direct dating of corona phases has rarely to be attempted. In order to decipher the timing and duration of corona formation and its implications for metamorphic processes, an integrated garnet Lu–Hf and Sm–Nd and zircon U–Pb petrochronological study was conducted on a corona-bearing granulite from the Miyun region in the North China Craton. The Miyun region, located at the joint area of the Archean Eastern Block and the Paleoproterozoic Trans-North China Orogen, offers a distinctive opportunity to study polymetamorphic processes within the North China Craton. The sample shows a corona texture, primarily composed of garnet, minor clinopyroxene and quartz, that formed at the boundary between plagioclase and orthopyroxene. Pseudosection modelling for the effective bulk composition of reactive domains and conventional thermobarometric calculations indicate that the anhydrous corona assemblage (comprising clinopyroxene, garnet and quartz) formed at ~ 0.9 GPa and ~ 740 ℃. The subsequent hydrous retrogression took place at ~ 0.5 GPa and ~ 670 ℃ and led to the growth of amphibole and biotite. A Lu–Hf garnet date of 1864 ± 3 Ma is significantly younger than the U–Pb date of ca. 2454 Ma for metamorphic zircons in the sample, consistent with the disequilibrium partitioning of rare earth elements between the two phases. The well-preserved Lu zoning in garnet supports the interpretation that the Lu–Hf date represents the age of garnet growth and approximates the timing of formation of the anhydrous corona assemblage. Thus, the U–Pb age reflects a distinct Archean metamorphic event that has been widely documented in high-grade rocks across the Eastern Block of the North China Craton. The garnet Sm–Nd date of 1817 ± 6 Ma is indistinguishable from an amphibole-biotite Lu–Hf date of 1819 ± 16 Ma and ~ 47 Myr younger than the corresponding garnet Lu–Hf date. The younger Sm–Nd age represents the timing of cooling and post-dates retrogression. The Paleoproterozoic and Archean ages in the Miyun granulite align with the major tectonic events in the Trans-North China Orogen and the Eastern Block, respectively. This consistency suggests that the Miyun region likely experienced concurrent metamorphic events in both the Trans-North China Orogen and the Eastern Block. This texture-based Lu–Hf and Sm–Nd dating approach has wide applicability for rocks with explicit textures, facilitating precise extraction of temporal intervals in the metamorphic process. [ABSTRACT FROM AUTHOR]

The purpose of this study is to assess the relative clinical efficacy of treating malignant hilar biliary obstruction (MHBO) via percutaneous unilateral or bilateral metal stenting. Relevant articles up to December 2019 were identified within the Web of science, Pubmed, Embase, and Cochrane Library databases. Stent dysfunction served as the primary endpoint, while we assessed technical success, clinical success, early and late complication incidence, and overall survival as secondary outcomes. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous variables. Hazard ratio (HR) with 95% CI were determined for overall survival. This meta-analysis included seven studies. Six studies were non-randomized controlled trials (RCTs) and one study was a RCT. A total of 888 MHBO patients underwent either percutaneous unilateral (n = 376) or bilateral (n = 512) metal stenting in these seven studies. We detected no significant differences in stent dysfunction rates (OR 0.97; 95% CI 0.67, 1.41, P = 0.89), technical success rates (OR 1.10; 95% CI 0.53, 2.29, P = 0.81), clinical success rates (OR 0.72; 95% CI 0.43, 1.22, P = 0.22), early complication rates (OR 0.82; 95% CI 0.34, 1.98, P = 0.66), late complication rates (OR 0.87; 95% CI 0.29, 2.63, P = 0.81), or overall survival (HR: 0.99; 95% CI 0.83, 1.17, P = 0.88) between unilateral and bilateral groups. Funnel plots demonstrated no obvious publication bias of these primary and secondary endpoints. From a clinical perspective, percutaneous unilateral and bilateral metal stenting are similarly effective for treatment of patients with MHBO. [ABSTRACT FROM AUTHOR]

Multiple output LED drivers are necessary to achieve better performance and higher reliability in street lighting, tunnel lighting and LCD background lighting applications. Based on LCL-T constant-current characteristics, a modular multiple output LED driver is proposed in this paper. The LCL-T rectifiers are connected to the same voltage bus and work like current sources. However, since there are much higher voltage harmonics in the AC square bus voltage, it is very important to quantitatively analyze how these harmonics influence the precision of the output currents. In addition, all of the switches can achieve Zero Voltage Switching (ZVS) by proper design of the LCL-T network. Finally, a 200-W prototype with five channels is established with an efficiency of 92.25%. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical outcomes between unilateral and bilateral metal stenting for patients with malignant hilar biliary obstruction (MHO). Methods: This is a single-center, open-label, prospective, randomized study. Between January 2016 and March 2018, patients with MHO who were treated by percutaneous unilateral or bilateral metal stenting were enrolled. The primary endpoint was stent dysfunction. The secondary endpoints included technical success, clinical success, adverse events, and death. The protocol is registered at ClinicalTrials.gov (identifier: NCT02649712). Results: A total of 72 patients were randomly grouped for the unilateral (n = 36) or bilateral (n = 36) stenting. The bilateral stenting was performed through the side-by-side technique. While technically, the rates of success of unilateral and bilateral stenting were 83.3% (30/36) in both the cases (P = 1.000), the clinical rates of success in unilateral and bilateral stenting were 90.0% (27/30) and 96.7% (29/30), respectively (P = 0.605). Based on the per-protocol analysis, stent dysfunction was found in 5 and 3 patients in unilateral and bilateral groups, respectively (16.7% vs. 10.0%, P = 0.704). No predictor was observed to influence stent dysfunction. The median cumulative survival in the unilateral group was 122 days and in the bilateral group was 125 days (P = 0.844). We also observed higher levels of post-operative total bilirubin and pre-operative alanine aminotransferase, and the absence of post-operative anticancer treatment as predictors of worse survival. Conclusion: When compared, the bilateral and unilateral stentings provide a similar clinical effectiveness in patients with MHO. [ABSTRACT FROM AUTHOR]