SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Zhang Zixuan) "

Sökning: WFRF:(Zhang Zixuan)

  • Resultat 1-21 av 21
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Beal, Jacob, et al. (författare)
  • Robust estimation of bacterial cell count from optical density
  • 2020
  • Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
  •  
2.
  • Bikdeli, Behnood, et al. (författare)
  • Individual Patient Data Pooled Analysis of Randomized Trials of Bivalirudin versus Heparin in Acute Myocardial Infarction : Rationale and Methodology
  • 2020
  • Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 120:2, s. 348-361
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Individual randomized controlled trials (RCTs) of periprocedural anticoagulation with bivalirudin versus heparin during percutaneous coronary intervention (PCI) have reported conflicting results. Study-level meta-analyses lack granularity to adjust for confounders, explore heterogeneity, or identify subgroups that may particularly benefit or be harmed.Objective To overcome these limitations, we sought to develop an individual patient-data pooled database of RCTs comparing bivalirudin versus heparin.Methods We conducted a systematic review to identify RCTs in which ≥1,000 patients with acute myocardial infarction (AMI) undergoing PCI were randomized to bivalirudin versus heparin.Results From 738 identified studies, 8 RCTs met the prespecified criteria. The principal investigators of each study agreed to provide patient-level data. The data were pooled and checked for accuracy against trial publications, with discrepancies addressed by consulting with the trialists. Consensus-based definitions were created to resolve differing antithrombotic, procedural, and outcome definitions. The project required 3.5 years to complete, and the final database includes 27,409 patients (13,346 randomized to bivalirudin and 14,063 randomized to heparin).Conclusion We have created a large individual patient database of bivalirudin versus heparin RCTs in patients with AMI undergoing PCI. This endeavor may help identify the optimal periprocedural anticoagulation regimen for patient groups with different relative risks of adverse ischemic versus bleeding events, including those with ST-segment and non-ST-segment elevation MI, radial versus femoral access, use of a prolonged bivalirudin infusion or glycoprotein inhibitors, and others. Adherence to standardized techniques and rigorous validation processes should increase confidence in the accuracy and robustness of the results..
  •  
3.
  • Feng, Ran, et al. (författare)
  • Past terrestrial hydroclimate sensitivity controlled by Earth system feedbacks
  • 2022
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Despite tectonic conditions and atmospheric CO2 levels (pCO2) similar to those of present-day, geological reconstructions from the mid-Pliocene (3.3-3.0 Ma) document high lake levels in the Sahel and mesic conditions in subtropical Eurasia, suggesting drastic reorganizations of subtropical terrestrial hydroclimate during this interval. Here, using a compilation of proxy data and multi-model paleoclimate simulations, we show that the mid-Pliocene hydroclimate state is not driven by direct CO2 radiative forcing but by a loss of northern high-latitude ice sheets and continental greening. These ice sheet and vegetation changes are long-term Earth system feedbacks to elevated pCO2. Further, the moist conditions in the Sahel and subtropical Eurasia during the mid-Pliocene are a product of enhanced tropospheric humidity and a stationary wave response to the surface warming pattern, which varies strongly with land cover changes. These findings highlight the potential for amplified terrestrial hydroclimate responses over long timescales to a sustained CO2 forcing.
  •  
4.
  • Han, Zixuan, et al. (författare)
  • Evaluating the large-scale hydrological cycle response within the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) ensemble
  • 2021
  • Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 17:6, s. 2537-2558
  • Tidskriftsartikel (refereegranskat)abstract
    • The mid-Pliocene (∼3 Ma) is one of the most recent warm periods with high CO2 concentrations in the atmosphere and resulting high temperatures, and it is often cited as an analog for near-term future climate change. Here, we apply a moisture budget analysis to investigate the response of the large-scale hydrological cycle at low latitudes within a 13-model ensemble from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2). The results show that increased atmospheric moisture content within the mid-Pliocene ensemble (due to the thermodynamic effect) results in wetter conditions over the deep tropics, i.e., the Pacific intertropical convergence zone (ITCZ) and the Maritime Continent, and drier conditions over the subtropics. Note that the dynamic effect plays a more important role than the thermodynamic effect in regional precipitation minus evaporation (PmE) changes (i.e., northward ITCZ shift and wetter northern Indian Ocean). The thermodynamic effect is offset to some extent by a dynamic effect involving a northward shift of the Hadley circulation that dries the deep tropics and moistens the subtropics in the Northern Hemisphere (i.e., the subtropical Pacific). From the perspective of Earth's energy budget, the enhanced southward cross-equatorial atmospheric transport (0.22 PW), induced by the hemispheric asymmetries of the atmospheric energy, favors an approximately 1∘ northward shift of the ITCZ. The shift of the ITCZ reorganizes atmospheric circulation, favoring a northward shift of the Hadley circulation. In addition, the Walker circulation consistently shifts westward within PlioMIP2 models, leading to wetter conditions over the northern Indian Ocean. The PlioMIP2 ensemble highlights that an imbalance of interhemispheric atmospheric energy during the mid-Pliocene could have led to changes in the dynamic effect, offsetting the thermodynamic effect and, hence, altering mid-Pliocene hydroclimate.
  •  
5.
  • Han, Zixuan, et al. (författare)
  • The changes in ENSO-induced tropical Pacific precipitation variability in the past warm and cold climates from the EC-Earth simulations
  • 2020
  • Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 55, s. 503-519
  • Tidskriftsartikel (refereegranskat)abstract
    • The El Nino-Southern Oscillation (ENSO) is one of the most significant climate variability signals. Studying the changes in ENSO-induced precipitation variability (ENSO precipitation) in the past climate offers a possibility to a better understanding of how they may change under future climate conditions. This study uses simulations performed with the European community Earth-System Model (EC-Earth) to investigate the relative contributions of dynamic effect (the circulation anomalies together with the climatological specific humidity) and thermodynamic effect (the specific humidity anomalies together with the climatological circulation) on the changes in ENSO precipitation in the past warm and cold climates, represented by the Pliocene and the Last Glacial Maximum (LGM), respectively. The results show that the changes in ENSO precipitation are intensified (weakened) over the tropical western Pacific but weakened (intensified) over the tropical central Pacific in Pliocene (LGM) compared with the pre-industrial (PI) simulation. Based on the decomposed moisture budget equation, these changes in ENSO precipitation patterns are highly related to the dynamic effect. The mechanism can be understood as follows: the zonal gradient of the mean sea surface temperature (SST) over the tropical Indo-Pacific is increased (reduced) during the Pliocene (LGM), leading to the strengthening (weakening) of Pacific Walker Circulation as well as a westward (eastward) shift. In the Pliocene, the westward shift of Walker Circulation results in an increased (decreased) ENSO-induced low-level vertical velocity variability in the tropical western Pacific (central Pacific), and, in turn, favoring convergent (divergent) moisture transport through a dynamic process, and then causing intensified (weakened) ENSO precipitation there. The opposite mechanism exists in LGM. These results suggest that changes in the zonal SST gradient over tropical Indo-Pacific under different climate conditions determine the changes in ENSO precipitation through a dynamic process.
  •  
6.
  • Liu, Shaohui, et al. (författare)
  • Data-Driven Controlled Synthesis of Oriented Quasi-Spherical CsPbBr3 Perovskite Materials
  • 2024
  • Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 63:14
  • Tidskriftsartikel (refereegranskat)abstract
    • Controlled synthesis of lead-halide perovskite crystals is challenging yet attractive because of the pivotal role played by the crystal structure and growth conditions in regulating their properties. This study introduces data-driven strategies for the controlled synthesis of oriented quasi-spherical CsPbBr3, alongside an investigation into the synthesis mechanism. High-throughput rapid characterization of absorption spectra and color under ultraviolet illumination was conducted using 23 possible ligands for the synthesis of CsPbBr3 crystals. The links between the absorption spectra slope (difference in the absorbance at 400 nm and 450 nm divided by a wavelength interval of 50 nm) and crystal size were determined through statistical analysis of more than 100 related publications. Big data analysis and machine learning were employed to investigate a total of 688 absorption spectra and 652 color values, revealing correlations between synthesis parameters and properties. Ex situ characterization confirmed successful synthesis of oriented quasi-spherical CsPbBr3 perovskites using polyvinylpyrrolidone and Acacia. Density functional theory calculations highlighted strong adsorption of Acacia on the (110) facet of CsPbBr3. Optical properties of the oriented quasi-spherical perovskites prepared with these data-driven strategies were significantly improved. This study demonstrates that data-driven controlled synthesis facilitates morphology-controlled perovskites with excellent optical properties.
  •  
7.
  • Weiffenbach, Julia E., et al. (författare)
  • Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2
  • 2023
  • Ingår i: Climate of the Past. - : COPERNICUS GESELLSCHAFT MBH. - 1814-9324 .- 1814-9332. ; 19:1, s. 61-85
  • Tidskriftsartikel (refereegranskat)abstract
    • The mid-Pliocene warm period (3.264-3.025 Ma) is the most recent geological period in which the atmospheric CO2 concentration was approximately equal to the concentration we measure today (ca. 400 ppm). Sea surface temperature (SST) proxies indicate above-average warming over the North Atlantic in the mid-Pliocene with respect to the pre-industrial period, which may be linked to an intensified Atlantic Meridional Overturning Circulation (AMOC). Earlier results from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) show that the ensemble simulates a stronger AMOC in the mid-Pliocene than in the pre-industrial. However, no consistent relationship between the stronger mid-Pliocene AMOC and either the Atlantic northward ocean heat transport (OHT) or average North Atlantic SSTs has been found. In this study, we look further into the drivers and consequences of a stronger AMOC in mid-Pliocene compared to pre-industrial simulations in PlioMIP2. We find that all model simulations with a closed Bering Strait and Canadian Archipelago show reduced freshwater transport from the Arctic Ocean into the North Atlantic. This contributes to an increase in salinity in the subpolar North Atlantic and Labrador Sea that can be linked to the stronger AMOC in the mid-Pliocene. To investigate the dynamics behind the ensembles variable response of the total Atlantic OHT to the stronger AMOC, we separate the Atlantic OHT into two components associated with either the overturning circulation or the wind-driven gyre circulation. While the ensemble mean of the overturning component is increased significantly in magnitude in the mid-Pliocene, it is partly compensated by a reduction in the gyre component in the northern subtropical gyre region. This indicates that the lack of relationship between the total OHT and AMOC is due to changes in OHT by the subtropical gyre. The overturning and gyre components should therefore be considered separately to gain a more complete understanding of the OHT response to a stronger mid-Pliocene AMOC. In addition, we show that the AMOC exerts a stronger influence on North Atlantic SSTs in the mid-Pliocene than in the pre-industrial, providing a possible explanation for the improved agreement of the PlioMIP2 ensemble mean SSTs with reconstructions in the North Atlantic.
  •  
8.
  • Xu, Xiaoxiang, et al. (författare)
  • Zeolitic imidazolate framework-90 loaded with methylprednisolone sodium succinate effectively reduces hypertrophic scar in vivo
  • 2024
  • Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 16:13, s. 6708-6719
  • Tidskriftsartikel (refereegranskat)abstract
    • Hypertrophic scar (HS) is characterized by an abnormal fibroblast-myofibroblast transformation; non-apoptosis of fibroblasts; and redundant expression of TGF-beta 1, VEGF, alpha-SMA, and collagen I/III. An HS affects patients' physical and psychological quality of life, leading to joint dysfunction and skin cancer. However, there is currently no satisfactory drug to treat this disorder. In this study, we constructed methylprednisolone sodium succinate (MPSS) encapsulated ZIF-90 (MPSS@ZIF-90) for the effective treatment of an HS. The encapsulation of MPSS in ZIF-90 can achieve the controllable drug release of MPSS and prolong its effective treatment time. MPSS@ZIF-90 enhanced the apoptosis of human hypertrophic scar fibroblasts and downregulated the overexpression of TGF-beta 1, VEGF, alpha-SMA, and collagen I/III both in vitro and in vivo. The instant injection of MPSS@ZIF-90 effectively intervened with the formation of the HS after 28 days. On the contrary, MPSS@ZIF-90 greatly reduced the HS with two injections and 14 days of treatment after the HS was formed. This work provides evidence of effective intervention in the formation of an HS and the therapeutic effectiveness of MPSS@ZIF-90 with short treatment periods in vivo. It suggests that MPSS@ZIF-90 can be used as a biomedical option in the treatment of skin wounds and may reveal the potential molecular basis for promising future antifibrotic agents against scarring.
  •  
9.
  • Zhang, Qiong, et al. (författare)
  • Simulating the mid-Holocene, last interglacial and mid-Pliocene climate with EC-Earth3-LR
  • 2021
  • Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 14:2, s. 1147-1169
  • Tidskriftsartikel (refereegranskat)abstract
    • As global warming is proceeding due to rising greenhouse gas concentrations, the Earth system moves towards climate states that challenge adaptation. Past Earth system states are offering possible modelling systems for the global warming of the coming decades. These include the climate of the mid-Pliocene (similar to 3 Ma), the last interglacial (similar to 129-116 ka) and the mid-Holocene (similar to 6 ka). The simulations for these past warm periods are the key experiments in the Paleoclimate Model Intercomparison Project (PMIP) phase 4, contributing to phase 6 of the Coupled Model Intercomparison Project (CMIP6). Paleoclimate modelling has long been regarded as a robust out-of-sample test bed of the climate models used to project future climate changes. Here, we document the model setup for PMIP4 experiments with EC-Earth3-LR and present the large-scale features from the simulations for the mid-Holocene, the last interglacial and the mid-Pliocene. Using the pre-industrial climate as a reference state, we show global temperature changes, large-scale Hadley circulation and Walker circulation, polar warming, global monsoons and the climate variability modes - El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). EC-Earth3-LR simulates reasonable climate responses during past warm periods, as shown in the other PMIP4-CMIP6 model ensemble. The systematic comparison of these climate changes in past three warm periods in an individual model demonstrates the model's ability to capture the climate response under different climate forcings, providing potential implications for confidence in future projections with the EC-Earth model.
  •  
10.
  • Zhong, Teng, et al. (författare)
  • A city-scale estimation of rooftop solar photovoltaic potential based on deep learning
  • 2021
  • Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 298
  • Tidskriftsartikel (refereegranskat)abstract
    • The estimation of rooftop solar photovoltaic (PV) potential is crucial for policymaking around sustainable energy plans. But it is difficult to accurately estimate the availability of rooftop area for solar radiation on a city-scale. In this study, a generic framework for estimating the rooftop solar PV potential on a city-scale using publicly available high-resolution satellite images is proposed. A deep learning-based method is developed to extract the rooftop area with image semantic segmentation automatically. A spatial optimization sampling strategy is developed to solve the labor-intensive problem when training the rooftop extraction model based on prior knowledge of urban and rural spatial layout and land use. In the case study of Nanjing, China, the labor cost on preparing the dataset for training the rooftop extraction model has been reduced by about 80% with the proposed spatial optimization sampling strategy. Meanwhile, the robustness of the rooftop extraction model in districts with different architectural styles and land use has been improved. The total rooftop area extracted was 330.36 km(2), and the overall accuracy reached 0.92. The estimation results show that Nanjing has significant potential for rooftop-mounted PV installations, and the potential installed capacity reached 66 GW. The annual rooftop solar PV potential was approximately 311,853 GWh, with a corresponding estimated power generation of 49,897 GWh in 2019.
  •  
11.
  • Gao, Shigen, et al. (författare)
  • Fuzzy adaptive automatic train operation control with protection constraints : A residual nonlinearity approximation-based approach
  • 2020
  • Ingår i: Engineering applications of artificial intelligence. - : Elsevier BV. - 0952-1976 .- 1873-6769. ; 96
  • Tidskriftsartikel (refereegranskat)abstract
    • In this study, we present fuzzy adaptive control based on residual nonlinearity approximation in the presence of protection constraints for the target trajectory tracking problem observed in automatic train operation. Herein, protection constraints refer to a condition wherein the speed and position of a controlled train are not allowed to surpass the boundaries imposed by automatic train protection and moving authority. By defining proper coordinate transformation, the protection constraints are converted to an error-prescribed performance control problem that facilitates operational efficiency by reducing the margin with respect to target trajectories. Based on the prescribed performance control methodology, we present an improved scheme using fuzzy residual nonlinearity approximation and establish the uniformly ultimately boundedness (UUB) property. A novel feature therein is that the ultimate boundary of the proposed scheme is simultaneously characterized by the prescribed performance functions and control parameters, with rigorous and analytically mathematical expressions; while pioneering the prescribed performance control methodology, the ultimate boundary is characterized solely by the prescribed performance functions. To verify the effectiveness and advantages of the proposed scheme, the controllers are applied to the automatic train operation on the Beijing Yizhuang line, which contains 13 operational intervals. Finally, comparative and simulation results are presented to validate the proposed method.
  •  
12.
  • Han, Zixuan, et al. (författare)
  • Changes in Sahel summer rainfall in a global warming climate : contrasting the mid-Pliocene and future regional hydrological cycles
  • 2023
  • Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 61:3-4, s. 1353-1370
  • Tidskriftsartikel (refereegranskat)abstract
    • The evolution of Sahel summer rainfall in the context of global warming is a severe socio-economic concern because of its widespread influences on local agriculture, water resource management, food security, infrastructure planning, and ecosystems. Based on the mid-Pliocene simulations from the Pliocene Model Intercomparison Project Phase 2 and the historical simulations and shared socio-economic pathway 5–8.5 experiments from the Coupled Model Intercomparison Project phase 6, the present study contrasts the Sahel summer rainfall changes between the past mid-Pliocene and near future global warming climates. The results show that the Western African summer monsoon (WASM) circulation, closely linked with the Sahel summer rainfall change, tends to strengthen in both the past and future global warming climates, but the monsoonal circulation strengthening is much more intense in the past warm period than in the projected warm future. This causes that the multi-model ensemble (MME) mean increase ratio of Sahel summer rainfall in the past warming climate is about twice to three times larger than that in the future warming climate for the same increase of global mean surface temperature (the regional rainfall increase ratio in the MME mean: about 19.6% per one degree Celsius of global warming in the mid-Pliocene simulations versus about 7.7% per one degree Celsius of global warming in the SSP5-8.5 future projections). Such a striking discrepancy in the regional circulation and hydrological cycle changes is mainly attributed to a dramatically stronger warming over the Canadian Archipelago and Greenland during the mid-Pliocene warm period relative to the projected near future. The more significant northern high-latitude warming during the mid-Pliocene enhances the meridional temperature gradient between the extratropical and tropical regions, which could induce an excessive northward shift of the Intertropical Convergence Zone and a stronger WASM, and thus result in a more intense hydrological cycle around the Sahel region. Our results highlight that besides the global mean temperature increase, meridional warming patterns are also essential for the changes of WASM and regional hydrological cycle in a warmer world. Implications for projecting the regional monsoon and hydrological cycle changes at longer time scales than in the near future are discussed. 
  •  
13.
  • Han, Zixuan, et al. (författare)
  • Impacts of Mid-Pliocene Ice Sheets and Vegetation on Afro-Asian Summer Monsoon Rainfall Revealed by EC-Earth Simulations
  • 2024
  • Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 51:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The impact of mid-Pliocene boundary conditions on Afro-Asian summer monsoon (AfroASM) rainfall is examined using the fully coupled Earth System Model EC-Earth3-LR. Our focus lies on the effects of varying CO2 concentration, diminished ice sheets and vegetation dynamics. We find that the enhanced AfroASM rainfall is predominantly caused by the “warmer-gets-wetter” mechanism due to elevated CO2 levels. Additionally, the ice sheet, similar in size to that of the mid-Pliocene era, creates several indirect effects. These include sea ice-albedo feedback and inter-hemispheric atmosphere energy transport. Such influences result in the southward shift of Hadley circulation and formation of Pacific-Japan pattern, leading to reduced rainfall in North African and South Asian monsoon regions but increased rainfall in East Asian monsoon region. Interestingly, while dynamic vegetation feedback has a minimal direct effect on AfroASM rainfall, it significantly influences rainfall in the mid-high latitudes of the North Hemisphere by enhancing water vapor feedback.
  •  
14.
  • Han, Zixuan, et al. (författare)
  • Thermodynamic and dynamic effects of increased moisture sources over the Tropical Indian Ocean in recent decades
  • 2019
  • Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 53:11, s. 7081-7096
  • Tidskriftsartikel (refereegranskat)abstract
    • In the present work, the mechanisms for the changes in moisture sources (evaporation minus precipitation; EmP) during boreal summer (May-September) are explored over the tropical Indian Ocean during 1979-2016. We apply a moisture budget analysis to quantify the thermodynamic and dynamic effects. Our results show that the EmP in the tropical central-eastern and southwestern Indian Oceans experienced significant increasing trends during boreal summer. The increased EmP in the tropical central-eastern Indian Ocean is due to the enhanced dynamic divergence (account for approximately 51%), while a stronger dynamic advection contributes more moisture supply to the southwestern Indian Ocean (account for approximately 34%). We find that during recent decades, the enhanced east-west thermal gradient in the Pacific strengthens the Walker Circulation, which leads to a westward shift in convection over the Indian Ocean warm pool, resulting in weakened convection and ascent over the tropical central-eastern Indian Ocean. The weakened convection leads to an anomalous low-level atmospheric divergent circulation, which intensifies the dynamic divergence contributing to the enhanced EmP over the tropical central-eastern Indian Ocean. Additionally, the warming climate during recent decades also increases the land-sea thermal contrast in the vicinity of the Indian Ocean, which enhances the southeastern wind in the low-level troposphere and leads to an enhanced EmP over the southwestern Indian Ocean.
  •  
15.
  • Konigstein, Maayan, et al. (författare)
  • Utility of the ACC/AHA Lesion Classification to Predict Outcomes After Contemporary DES Treatment: Individual Patient Data Pooled Analysis From 7 Randomized Trials.
  • 2022
  • Ingår i: Journal of the American Heart Association. - 2047-9980.
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Use of the modified American College of Cardiology (ACC)/American Heart Association (AHA) lesion classification as a prognostic tool to predict short- and long-term clinical outcomes after percutaneous coronary intervention in the modern drug-eluting stent era is uncertain. Methods and Results Patient-level data from 7 prospective, randomized trials were pooled. Clinical outcomes of patients undergoing single lesion percutaneous coronary intervention with second-generation drug-eluting stent were analyzed according to modified ACC/AHA lesion class. The primary end point was target lesion failure (TLF: composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization). Clinical outcomes to 5 years were compared between patients treated for noncomplex (class A/B1) versus complex (class B2/C) lesions. Eight thousand five hundred sixteen patients (age 63.1±10.8 years, 70.5% male) were analyzed. Lesions were classified as A, B1, B2, and C in 7.9%, 28.5%, 33.7%, and 30.0% of cases, respectively. Target lesion failure was higher in patients undergoing percutaneous coronary intervention of complex versus noncomplex lesions at 30 days (2.0% versus 1.1%, P=0.004), at 1 year (4.6% versus 3.0%, P=0.0005), and at 5 years (12.4% versus 9.2%, P=0.0001). By multivariable analysis, treatment of ACC/AHA class B2/C lesions was significantly associated with higher rate of 5-year target lesion failure (adjusted hazard ratio, 1.39 [95% CI, 1.17-1.64], P=0.0001) driven by significantly higher rates of target vessel myocardial infarction and ischemia-driven target lesion revascularization. Conclusions In this pooled large-scale analysis, treating complex compared with noncomplex lesions according to the modified ACC/AHA classification with second-generation drug-eluting stent was associated with worse 5-year clinical outcomes. This historical classification system may be useful in the contemporary era for predicting early and late outcomes following percutaneous coronary intervention.
  •  
16.
  • Kosmidou, Ioanna, et al. (författare)
  • Sex-Specific Outcomes of Transcatheter Mitral-Valve Repair and Medical Therapy for Mitral Regurgitation in Heart Failure.
  • 2021
  • Ingår i: JACC. Heart failure. - 2213-1787.
  • Tidskriftsartikel (refereegranskat)abstract
    • This study sought to assess the sex-specific outcomes in patients with heart failure (HF) with 3+ and 4+ secondary mitral regurgitation (SMR) treated with transcatheter mitral valve repair (TMVr) plus guideline-directed medical therapy (GDMT) versus GDMT alone in the COAPT trial.The impact of sex in patients with HF and severe SMR treated with TMVr with the MitraClip compared with GDMT alone is unknown.Patients were randomized 1:1 to TMVr versus GDMT alone. Two-year outcomes were examined according to sex.Among 614 patients, 221 (36.0%) were women. Women were younger than men and had fewer comorbidities, but reduced quality of life and functional capacity at baseline. In a joint frailty model accounting for the competing risk of death, the 2-year cumulative incidence of the primary endpoint of all HF hospitalizations (HFH) was higher in men compared with women treated with GDMT alone. However, the relative reduction in HFHs with TMVr was greater in men (HR: 0.43; 95% CI: 0.34-0.54) than women (HR: 0.78; 95% CI: 0.57-1.05) (Pinteraction = 0.002). A significant interaction between TMVr versus GDMT alone treatment and time was present for all HFHs in women (HR: 0.57; 95% CI: 0.39-0.84, and HR: 1.39; 95% CI: 0.83-2.33 between 0-1 year and 1-2 years after randomization, respectively, Pinteraction = 0.007) but not in men (HR: 0.48; 95% CI: 0.36-0.64, and HR: 0.33; 95% CI: 0.21-0.51; Pinteraction = 0.16). Female sex was independently associated with a lower adjusted risk of death at 2 years (HR: 0.64; 95% CI: 0.46-0.90; P = 0.011). TMVr consistently reduced 2-year mortality compared with GDMT alone, irrespective of sex (Pinteraction = 0.99).In the COAPT trial, TMVr with the MitraClip resulted in improved clinical outcomes compared with GDMT alone, irrespective of sex. However, the impact of TMVr in reducing HFH was less pronounced in women compared with men beyond the first year after treatment. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Tria] [COAPT]) NCT01626079.
  •  
17.
  • Mehdipoor, Ghazaleh, et al. (författare)
  • Hypertension, Microvascular Obstruction and Infarct Size in Patients with STEMI Undergoing PCI: Pooled Analysis from 7 Cardiac Magnetic Resonance Imaging Studies.
  • 2024
  • Ingår i: American heart journal. - 1097-6744.
  • Tidskriftsartikel (refereegranskat)abstract
    • Mortality after ST-segment elevation myocardial infarction (STEMI) is increased in patients with hypertension. The mechanisms underlying this association are uncertain. We sought to investigate whether patients with STEMI and prior hypertension have greater microvascular obstruction (MVO) and infarct size (IS) compared with those without hypertension.We pooled individual patient data from 7 randomized trials of patients with STEMI undergoing primary percutaneous coronary intervention (PCI) in whom cardiac magnetic resonance imaging was performed within 1 month after reperfusion. The associations between hypertension and MVO, IS, and mortality were assessed in multivariable adjusted models.Among 2174 patients (61.3±12.6 years, 76% male), 1196 (55.0%) had hypertension. Patients with hypertension were older, more frequently diabetic and had more extensive coronary artery disease than those without hypertension. MVO and IS measured as percent LV mass were not significantly different in patients with and without hypertension (adjusted differences 0.1, 95% CI -0.3 to 0.6, p=0.61 and -0.2, 95% CI -1.5 to 1.2, p=0.80, respectively). Hypertension was associated with a higher unadjusted risk of 1-year death (hazard ratio [HR] 2.28, 95% CI 1.44-3.60, p<0.001), but was not independently associated with higher mortality after multivariable adjustment (adjusted HR 1.04, 95% CI 0.60-1.79, p=0.90).In this large-scale individual patient data pooled analysis, hypertension was not associated with larger IS or MVO after primary PCI for STEMI.
  •  
18.
  • Redfors, Björn, et al. (författare)
  • Ambient temperature and infarct size, microvascular obstruction, left ventricular function and clinical outcomes after ST-segment elevation myocardial infarction.
  • 2022
  • Ingår i: Coronary artery disease. - 1473-5830. ; 33:2, s. 81-90
  • Tidskriftsartikel (refereegranskat)abstract
    • Incidence and prognosis of ST-segment elevation myocardial infarction (STEMI) vary according to ambient temperature and season. We sought to assess whether season and temperature on the day of STEMI are associated with infarct size, microvascular obstruction (MVO), left ventricular ejection fraction (LVEF) and clinical outcomes after primary percutaneous coronary intervention (PCI).Individual patient data from 1598 patients undergoing primary PCI in six randomized clinical trials were pooled. Infarct size was evaluated by cardiac magnetic resonance within 30days in all trials. Patients were categorized either by whether they presented on a day of temperature extremes (minimum temperature <0 °C or maximum temperature >25 °C) or according to season.A total of 558/1598 (34.9%) patients presented with STEMI on a day of temperature extremes, and 395 (24.7%), 374 (23.4%), 481 (30.1%) and 348 (21.8%) presented in the spring, summer, fall and winter. After multivariable adjustment, temperature extremes were independently associated with larger infarct size (adjusted difference 2.8%; 95% CI, 1.3-4.3; P<0.001) and smaller LVEF (adjusted difference -2.3%; 95% CI, -3.5 to -1.1; P=0.0002) but not with MVO (adjusted P=0.12). In contrast, infarct size, MVO and LVEF were unrelated to season (adjusted P=0.67; P=0.36 and P=0.95, respectively). Neither temperature extremes nor season were independently associated with 1-year risk of death or heart failure hospitalization (adjusted P=0.79 and P=0.90, respectively).STEMI presentation during temperature extremes was independently associated with larger infarct size and lower LVEF but not with MVO after primary PCI, whereas season was unrelated to infarct severity.
  •  
19.
  • Shah, Neeraj, et al. (författare)
  • Prediction of Death or HF Hospitalization in Patients With Severe FMR: The COAPT Risk Score.
  • 2022
  • Ingår i: JACC. Cardiovascular interventions. - 1876-7605. ; 15:19, s. 1893-1905
  • Tidskriftsartikel (refereegranskat)abstract
    • There are limited data on the predictors of death or heart failure hospitalization (HFH) in patients with heart failure (HF) with functional mitral regurgitation (FMR).The aim of this study was to develop a predictive risk score using the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial database.In COAPT, 614 symptomatic patients with HF and moderate to severe or severe FMR were randomized to MitraClip implantation plus guideline-directed medical therapy (GDMT) or GDMT alone. A risk score for the 2-year rate of death or HFH was generated from Cox proportional hazards models. The predictive value of the model was assessed using the area under the curve of receiver-operating characteristic plots. Kaplan-Meier curves were generated to estimate the proportion of patients experiencing death or HFH across quartiles of risk.During 2-year follow-up, 201 patients (64.4%) in the GDMT-alone group and 133 patients (44.0%) in the MitraClip group experienced death or HFH (P < 0.001). A risk score containing 4 clinical variables (New York Heart Association functional class, chronic obstructive pulmonary disease, atrial fibrillation or flutter, and chronic kidney disease) and 4 echocardiographic variables (left ventricular ejection fraction, left ventricular end-systolic dimension, right ventricular systolic pressure, and tricuspid regurgitation) in addition to MitraClip treatment was generated. The area under the curve of the risk score model was 0.74, and excellent calibration was present. The relative benefit of MitraClip therapy in reducing the 2-year hazard of death or HFH was consistent across the range of baseline risk.A simple risk score of clinical, echocardiographic, and treatment variables may provide useful prognostication in patients with HF and severe FMR.
  •  
20.
  • Simonato, Matheus, et al. (författare)
  • Consequences of Inaccurate Assumptions in Coronary Stent Noninferiority Trials: A Systematic Review and Meta-analysis.
  • 2022
  • Ingår i: JAMA cardiology. - 2380-6591. ; 7:3, s. 320-327
  • Tidskriftsartikel (refereegranskat)abstract
    • The outcome and interpretation of noninferiority trials depend on the magnitude of the noninferiority margin and whether a relative or absolute noninferiority margin is used and may be affected by imprecision in event rate estimation.To assess the consequence of imprecise event rate estimations on interpretation of peer-reviewed randomized clinical trials.PubMed/MEDLINE was searched for articles published between January 1, 2015, and April 30, 2021.Noninferiority randomized clinical trials of coronary stents published in selected journals with clinical events as the primary end point.Two reviewers (M.S. and F.V.) independently extracted data on trial characteristics, noninferiority assumptions, primary end point clinical outcomes, and study conclusions. Overestimation or underestimation of the control event rate was evaluated by dividing the assumed control event rate by the observed control event rate. For noninferiority end points with absolute margins, the assumed corresponding relative margin was defined as the ratio of the absolute margin and the assumed event rate, and the observed corresponding relative margin as the ratio between the absolute margin and the observed event rate in the control arm. Noninferiority comparisons with absolute margins were reanalyzed using the assumed corresponding relative margin and the Farrington-Manning score test for relative risk.Overestimation or underestimation, assumed and observed corresponding relative margins, and relative reanalysis of the primary end points of trials with absolute margins.A total of 106 989 patients from 58 trials were included. The event rate in the control arms was overestimated by a median (IQR) of 28% (2%-74%). Most noninferiority trials used absolute rather than relative margins (55 of 58 trials [94.8%]). Owing to overestimation, absolute noninferiority margins became more permissive than originally assumed (median [IQR] of observed relative noninferiority margin, 1.62 [1.50-1.80] vs assumed relative noninferiority margin, 1.47 [1.39-1.55]; P < .001). Among trial comparisons that met noninferiority with an absolute noninferiority margin, 17 of 50 trials (34.0%) would not have met noninferiority with a corresponding assumed relative noninferiority margin.In this systematic review and meta-analysis, assumed event rates were often overestimated in noninferiority coronary stent trials. Because most of these trials use absolute margins to define noninferiority, such overestimation results in excessively permissive relative noninferiority margins.
  •  
21.
  • Yang, Junhuai, et al. (författare)
  • Holocene forcing of aeolian dust activity over the Tibetan Plateau and its surroundings
  • 2024
  • Ingår i: Global and Planetary Change. - 0921-8181 .- 1872-6364. ; 235
  • Tidskriftsartikel (refereegranskat)abstract
    • Aeolian deposits on the Tibetan Plateau (TP) and its surroundings provide crucial source materials for the Asian dust cycle, which significantly affects Asian and global ecosystems and climate. However, it is unclear how the dust dynamics of the TP and its surroundings are linked to Earth's climate system. To address this issue, we examined the grain size and accumulation rate of six Holocene aeolian sections on the southern TP (a new, well-dated high-resolution section, two relatively low-resolution sections, and three published sections) and combined them with equivalent aeolian sedimentary records from eastern arid central Asia. The results suggest that dust activity in both regions decreased during the early to middle Holocene and then increased in the late Holocene. We hypothesize that the primary drivers of Holocene dust activity in both regions are similar. Cold-season insolation, as the primary driving factor, combined with ice volume and atmospheric CO2 concentration, collectively controlled the regional temperature, which determined the near-surface wind intensity via its influence on the TP High and Siberian High, respectively, thus ultimately controlling the regional dust activity. In this context, we project that dust activity on the TP and its neighboring areas will decrease under warm scenarios in the 21st century. Overall, our findings provide an extensive overview of the past, present, and future scenarios of Asian dust activity, especially of the TP dust.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-21 av 21
Typ av publikation
tidskriftsartikel (21)
Typ av innehåll
refereegranskat (21)
Författare/redaktör
Zhang, Zixuan (9)
Han, Zixuan (8)
Zhang, Qiong (7)
Redfors, Björn (6)
Stone, Gregg W. (6)
Ben-Yehuda, Ori (4)
visa fler...
Li, Qiang (4)
Li, Xiangyu (3)
Haywood, Alan M. (3)
Tindall, Julia C. (3)
Zhang, Zhongshi (3)
Guo, Chuncheng (3)
Stepanek, Christian (3)
Lohmann, Gerrit (3)
Tan, Ning (3)
Chandan, Deepak (3)
Williams, Charles J. ... (3)
Lunt, Daniel J. (3)
Feng, Ran (3)
Otto-Bliesner, Bette ... (3)
Brady, Esther C. (3)
Chen, Shmuel (3)
Peltier, W. Richard (3)
Maehara, Akiko (2)
Ohman, E. Magnus (2)
Mack, Michael J. (2)
Mehran, Roxana (2)
Patel, Manesh R. (2)
Zhang, Xinyu (2)
Yang, Shuting (2)
Hunter, Stephen J. (2)
Nisancioglu, Kerim H ... (2)
Sohl, Linda E. (2)
Chandler, Mark A. (2)
Contoux, Camille (2)
Ramstein, Gilles (2)
Baatsen, Michiel L. ... (2)
von der Heydt, Anna ... (2)
Abe-Ouchi, Ayako (2)
Chan, Wing-Le (2)
Mehdipoor, Ghazaleh (2)
Thiele, Holger (2)
Zhang, Qiang (2)
Lu, Zhengyao (2)
Li, Gen (2)
Lindenfeld, JoAnn (2)
Simonato, Matheus (2)
Abraham, William T (2)
Madhavan, Mahesh V. (2)
Eitel, Ingo (2)
visa färre...
Lärosäte
Stockholms universitet (9)
Göteborgs universitet (6)
Kungliga Tekniska Högskolan (3)
Lunds universitet (3)
Linköpings universitet (2)
Uppsala universitet (1)
visa fler...
Mälardalens universitet (1)
Chalmers tekniska högskola (1)
visa färre...
Språk
Engelska (21)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (11)
Medicin och hälsovetenskap (8)
Teknik (2)
Lantbruksvetenskap (1)
Samhällsvetenskap (1)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy