9 research outputs found
A Spatiotemporal Pattern Analysis of High-Frequency Land-Use Changes in the Guangdong–Hong Kong–Macao Greater Bay Area, from 1990 to 2018
With continuous rises in GDP, land cover in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) has undergone a drastic change over the period 1990–2018. In this study, land use in the GBA was divided into six types: farmland, forestland, grassland, wetland, construction land, and unused land. We analyzed changes in spatiotemporal patterns according to region and type by using statistical analysis, spatial clustering, and hotspot analysis, focusing on the spatial characteristics of areas where land-use types changed with high frequency. The high-frequency land use in the GBA has strategic guidance for further urban planning and management. With discussions on urban planning, the natural environment, and social and economic development, we found the following: (1) Urban construction land in the GBA showed a unipolar growth mode, increasing from 5.63% to 14.34% from 1990 to 2018. Accordingly, the degree of urban concentration and contiguity rose continuously. (2) Hotspots with frequent land-use changes were concentrated mainly in areas with economic intensity. (3) Plots with high-frequency land-use changes (Flc > 2) were concentrated primarily in the waters and rivers of the GBA within 10 km of the administrative boundaries of prefecture-level cities. (4) Nearly 80% of the land has been or will be transformed into ecological land over the period 1990–2018. On the basis of these findings, we suggest further improving land-use efficiency, and ecological land damage and the over-occupation of sea space should be avoided while maintaining economic growth. Thus, linking increases and decreases in construction land is an excellent land-consolidation mechanism to transform inefficient urban land into ecological land
Unexpected C–C Bond Cleavage: A Route to 3,6-Diarylpyridazines and 6‑Arylpyridazin-3-ones from 1,3-Dicarbonyl Compounds and Methyl Ketones
An unexpected C–C bond cleavage has been revealed
in the
absence of metal. This observation has been exploited to develop an
efficient approach toward 3,6-diarylpyridazines and 6-arylpyridazin-3-ones
from simple and commercially available 1,3-dicarbonyl compounds and
methyl ketones
Unexpected C–C Bond Cleavage: A Route to 3,6-Diarylpyridazines and 6‑Arylpyridazin-3-ones from 1,3-Dicarbonyl Compounds and Methyl Ketones
An unexpected C–C bond cleavage has been revealed
in the
absence of metal. This observation has been exploited to develop an
efficient approach toward 3,6-diarylpyridazines and 6-arylpyridazin-3-ones
from simple and commercially available 1,3-dicarbonyl compounds and
methyl ketones
Unexpected C–C Bond Cleavage: A Route to 3,6-Diarylpyridazines and 6‑Arylpyridazin-3-ones from 1,3-Dicarbonyl Compounds and Methyl Ketones
An unexpected C–C bond cleavage has been revealed
in the
absence of metal. This observation has been exploited to develop an
efficient approach toward 3,6-diarylpyridazines and 6-arylpyridazin-3-ones
from simple and commercially available 1,3-dicarbonyl compounds and
methyl ketones
Association of Stroke Subtype With Hemorrhagic Transformation Mediated by Thrombectomy Pass: Data From the ANGEL-ACT Registry
Background: The role of stroke etiology subtype in patients with acute large vessel occlusion on the occurrence of hemorrhagic transformation (HT) after endovascular treatment is poorly studied, and which factors mediate their relationship remains largely unknown. We utilized nationwide registry data to explore the association of stroke subtype (cardioembolism versus large artery atherosclerosis) with HT and to identify the possible mediators.
Methods: A total of 1015 subjects were selected from the ANGEL-ACT registry (Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemic Stroke)—a prospective consecutive cohort of acute large vessel occlusion patients undergoing endovascular treatment at 111 hospitals in China between November 2017 and March 2019—and divided into large artery atherosclerosis (n=538) and cardioembolism (n=477) according to the Trial of ORG 10172 in Acute Stroke Treatment criteria. The types of HT included any intracerebral hemorrhage (ICH), parenchymal hematoma, and symptomatic ICH within 24 hours after endovascular treatment. The association between stroke subtype and HT was analyzed using a logistic regression model. Mediation analysis was done to assess how much of the effect of stroke subtype on HT was mediated through the identified mediators. Results: Stroke subtype (cardioembolism versus large artery atherosclerosis) was associated with increased risk of any ICH (29.8% versus 16.5%; odds ratio, 2.03 [95% CI, 1.22–3.36]), parenchymal hematoma (14.3% versus 5.4%; odds ratio, 2.90 [95% CI, 1.38–6.13]), and symptomatic ICH (9.9% versus 4.7%; odds ratio, 2.59 [95% CI, 1.09–6.16]) after adjustment for potential confounders. The more thrombectomy passes in cardioembolism patients had a significant mediation effect on the association of stroke subtype with increased risk of HT (any ICH, 15.9%; parenchymal hematoma, 13.4%; symptomatic ICH, 14.2%, respectively).
Conclusion: Stroke subtype is an independent risk factor for HT within 24 hours following endovascular treatment among acute large vessel occlusion patients. Mediation analyses propose that stroke subtype contributes to HT partly through thrombectomy pass, suggesting a possible pathomechanistic link
Combined Approach to Eptifibatide and Thrombectomy in Acute Ischemic Stroke Because of Large Vessel Occlusion: A Matched-Control Analysis
Background: In patients undergoing mechanical thrombectomy (MT), adjunctive antithrombotic might improve angiographic reperfusion, reduce the risk of distal emboli and reocclusion but possibly expose patients to a higher intracranial hemorrhage risk. This study evaluated the safety and efficacy of combined MT plus eptifibatide for acute ischemic stroke.
Methods: This was a propensity-matched analysis of data from 2 prospective trials in Chinese populations: the ANGEL-ACT trial (Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischemic Stroke) in 111 hospitals between November 2017 and March 2019, and the EPOCH trial (Eptifibatide in Endovascular Treatment of Acute Ischemic Stroke) in 15 hospitals between April 2019 and March 2020. The primary efficacy outcome was good outcome (modified Rankin Scale score 0–2) at 3 months. Secondary efficacy outcomes included the distribution of 3-month modified Rankin Scale scores and poor outcome (modified Rankin Scale score 5–6) and successful recanalization. The safety outcomes included any intracranial hemorrhage, symptomatic intracranial hemorrhage, and 3-month mortality. Mixed-effects logistic regression models were used to account for within-hospital clustering in adjusted analyses.
Results: Eighty-one combination arm EPOCH subjects were matched with 81 ANGEL-ACT noneptifibatide patients. Compared with the no eptifibatide group, the eptifibatide group had significantly higher rates of successful recanalization (91.3% versus 81.5%; P=0.043) and 3-month good outcomes (53.1% versus 33.3%; P=0.016). No significant difference was found in the remaining outcome measures between the 2 groups. All outcome measures of propensity score matching were consistent with mixed-effects logistic regression models in the total population.
Conclusion: This matched-control study demonstrated that MT combined with eptifibatide did not raise major safety concerns and showed a trend of better efficacy outcomes compared with MT alone. Overall, eptifibatide shows potential as a periprocedural adjunctive antithrombotic therapy when combined with MT. Further randomized controlled trials of MT plus eptifibatide should be prioritized.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03844594 (EPOCH), NCT03370939 (ANGEL-ACT)