Explore the vast range of titles available.

The Central Depression of the Junggar Basin relies heavily on Permian lacustrine mudstone for deep-seated hydrocarbon sealing. This research investigated how the fluorescence parameters of caprock samples responded to the leakage of palaeo-oil zones based on measurements from SEM, Rock-Eval, and X-ray diffraction analysis. First, two sets of control experiments were conducted to establish the proper grain-size range of 100–140 mesh for testing caprock samples in the research area using quantitative fluorescence technology. Subsequently, based on the examination of the rock pyrolysis parameters and the fluorescence parameters against TOC values, the conjecture was formed that the quantitative fluorescence technology test results were mostly unaffected by the primary hydrocarbons. Lastly, four fluorescence parameters were used to assess seal integrity: quantitative grain fluorescence intensity of the extract (QGF E intensity, the meaning of QGF is the same in this study), QGF spectral peaks (QGF λmax), the ratio of QGF intensity to fluorescence intensity at 300 nm on the QGF spectrum (QGF index), and total scanning fluorescence spectral ratio R1 (TSF R1). The Permian caprock can effectively seal hydrocarbons as evidenced by the decrease of QGF E intensity and QGF index values with depth. When hydraulic fracturing causes caprock failure, it can lead to complete leakage of hydrocarbons from the palaeo-oil zones. As the depth becomes shallower, the QGF E intensity value increases, the QGF index value decreases. Due to the differences in the migration pathways of hydrocarbons in the caprock, those leaked from the Permian palaeo-oil zone into the well PD1 caprock are mainly condensate and light–normal crude oil, while the hydrocarbons from the Carboniferous palaeo-oil zone into the well MS1 caprock consist predominantly of light–normal crude oil and medium–heavy crude oil.

Background Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. General anesthesia (GA) resolves the problem of pain intolerability and provides regular respiratory mode which might improve the catheter maneuverability of AF ablation. This study aims to compare the procedural performance of PVI under GA versus conscious sedation (CS) from multiple perspectives. Methods A total of 36 consecutive patients undergoing first AF ablation under GA were enrolled in GA group. Another 109 patients receiving AF ablation under CS in the same period were selected as the control group. After propensity score matching, 29 matched pairs with similar baseline characteristics were available for further analysis. The AIFV (using AI to analyze the raw data from CARTO3 system) system was used to evaluate six procedural parameters in each PVI procedure. Results Compared with CS, PVI under GA had a significantly shorter total PVI time (51.4 min vs. 67.8 min; p = .003) and higher radiofrequency ratio (62.6% vs. 55.8%; p = .032). The number of gaps (1.0 vs. 3.0; p < .001) and the rate of break point were significantly lower in the GA group. GA was also associated with a higher effective ablation‐index ratio (87.5% vs. 74.1%; p < .001) and effective force‐over‐time ratio (85.3% vs. 69.2%; p = .001). After a medium follow‐up time of 24 months, 12/29 (41.4%) patients in the CS group and 6/29 (20.7%) patients in the GA group suffered from AF recurrence (p = .156). Conclusions GA improves the lesion quality and procedural efficiency of PVI from multiple perspectives evaluated by the AIFV system. A high‐quality pulmonary vein isolation is the foundation for improving the single‐procedure success rate of AF ablation. AIFV is a novel system designed to describe the overall quality for the two pulmonary vein circles. General anesthesia can safely improve the PVI lesion quality and procedural efficiency from multiple perspectives evaluated by AIFV system.

This study investigates the genetic types and accumulation characteristics of natural gas from the Permian Jiamuhe Formation in the Zhongguai Uplift, Junggar Basin, through an integrated geochemical analysis of 23 natural gas samples. The analytical techniques included chemical composition analysis, stable carbon (δ 13 C) and hydrogen (δ 2 H) isotope analysis of individual alkanes (C 1 –C 4 ), and position-specific carbon isotope analysis of propane. The results indicate that the natural gases are predominantly dry gas, with an average dryness coefficient (C 1 /(C 1 –C 5 )) of 0.97 and methane content ranging from 75.23% to 95.98%. The stable carbon isotopic compositions generally show an increasing trend from methane to propane, although many samples exhibit partial C 2 –C 3 isotopic rollover, reflecting complex isotopic behavior typical of thermogenic gases. Critically, the ethane carbon isotopic values (δ 13 C 2 : − 27.5‰ to − 24.6‰) are predominantly heavier than − 28‰, suggesting a coal-derived origin. Plotting on a Bernard diagram confirms their classification within the thermogenic gas field. The position-specific isotope data of propane reveals a consistent isotopic difference between the methylene and methyl carbon, indicating formation primarily via the n-propyl pathway during kerogen cracking, with no clear isotopic evidence for significant alteration. The study concludes that the natural gas in the Zhongguai Uplift is mainly coal-derived thermogenic gas generated from Type III kerogen, with its accumulation controlled by the interplay of hydrocarbon kitchens, fault-fracture migration pathways, and favorable reservoir conditions in the Jiamuhe Formation.

Nowcasting is a critical technology for disaster prevention and mitigation, and the accuracy of radar echo extrapolation directly impacts forecasting performance. In most deep learning-based models, accurately predicting heavy precipitation remains a challenging task. Focusing on the region of China, this study proposes an improved model based on residual and attention mechanisms—RA-UNet—for precipitation nowcasting with a lead time of 3 h. The model introduces the residual neural network (ResNet) and the convolutional block attention module (CBAM) to integrate multi-scale features into the U-Net encoder–decoder architecture, enhancing its ability to capture the spatiotemporal evolution of precipitation systems. Meanwhile, depthwise separable convolutions are employed to replace conventional convolutions, significantly improving computational efficiency while preserving model performance. To evaluate the model’s performance, experiments were conducted using 6 min resolution radar echo data from China in 2024, with comparisons made against the optical flow (OF) method and the U-Net model. The experimental results show that RA-UNet demonstrates significant advantages in 3 h forecasting: its mean absolute error (MAE) is reduced by approximately 7%, the false alarm rate (FAR) decreases by about 20%, and it outperforms the comparison models in metrics such as the critical success index (CSI) and structural similarity index (SSIM). Notably, RA-UNet effectively mitigates intensity degradation in long-term forecasts, successfully predicting the trend of >40 dBZ strong echo cores in two typical cases and significantly improving the premature dissipation problem of precipitation fields. This study provides a new approach to refined forecasting of complex precipitation systems, and future work will combine multi-source data fusion with physical constraint mechanisms to further enhance precipitation event prediction capabilities.

BackgroundThe role of catheter ablation as an adjunct and alternative to ICD implantation is not known in patients at risk for recurrent ventricular tachycardia (VT) and sudden cardiac death (SCD) across Asia. Patients with nonischemic etiologies of cardiomyopathy, which are highly prevalent in Asia, have not been previously enrolled in randomized trials of VT ablation.ObjectiveTo evaluate whether preemptive catheter ablation in patients with monomorphic VT and an indication for ICD implantation results in improved clinical outcomes compared to ICD implantation with standard medical therapy alone. To examine the natural history of ablation outcomes in the absence of background ICD therapy in patients that refuse randomization.MethodsThe PAUSE-SCD study (NCT02848781) is a prospective, multi-center, randomized controlled trial enrolling patients with structural heart disease (EF < 50%) with an indication for ICD implantation. Patients are randomized in a 1:1 fashion to two treatment arms: ICD with ablation and ICD with standard medical therapy alone. A prospective registry cohort was designed to follow the outcomes of patients who refuse ICD and randomization but elect to receive catheter ablation as primary therapy. The primary endpoint is defined as a composite of recurrent VT, cardiovascular rehospitalization, and death. Pre-specified secondary endpoints include each of the individual components of the primary endpoint in addition to comparison between randomized and registry patients.ConclusionThe PAUSE-SCD study is a prospective, multi-center, randomized, and controlled trial examining the impact of preemptive catheter ablation on cardiovascular outcomes in patients with an indication for ICD at risk for recurrent VT and SCD. It represents the first multi-center VT ablation study in Asia, with a design intended to provide insights into the role of both ICD and ablation therapy in a predominantly nonischemic population.

Microwave surface emissivity is complex and variable, leading to increased difficulty in accurately retrieving atmospheric parameters and assimilating satellite microwave observations over land. The Community Radiative Transfer Model (CRTM) land emissivity model is a useful tool for providing microwave emissivity over complex surfaces. By combining the model with ground measurements from a mobile multi-surface observing system at the Xianghe site, China, the performance of the land emissivity model is evaluated over grass and sand surfaces. The simulated and measured emissivity agrees at both polarizations over the grassland surface but a more significant difference is observed at the horizontal polarization over the sand surface. To solve this problem, the Q/H module for soil reflectance roughness correction in the CRTM emissivity model was replaced with the Qp module for the sand surface. This results in a significant improvement in the horizontal polarization simulation, with the corresponding mean bias error (MBE) reducing from 0.08 in the Q/H module to less than 0.03. The adjustment demonstrates that the Qp module more effectively corrects the roughness effect on horizontally polarized emissivity for bare soil surfaces. For grassland, the CRTM emissivity model with the Q/H module demonstrates accurate simulations, showing its suitability for vegetated land surfaces.

Introduction Prolonged sinus pause (PSP) after atrial fibrillation (AF) termination shortly after catheter ablation seems to be a reversible phenomenon without further need for pacemaker implantation (PMI). However, no mature management strategy has been established. Methods In this prospective observational study, we included consecutive patients who developed PSP ≥ 3 s upon AF termination during hospitalization following AF ablation at our center between October 2020 and October 2022. Regular follow‐up was conducted. Results Twelve patients (mean age 66.3 ± 8.5 years; 7 females) were included. PSP ≥ 3 s upon AF termination initiated at a median of 2.0 days (IQR: 1.3–3.8) post‐ablation and resolved by 5.0 days (IQR: 3.5–7.5). Three patients received temporary PMI, all of which were removed before discharge without further pacing. One patient underwent permanent PMI during hospitalization due to Adams‐Stokes syndrome. After discharge, one patient received permanent pacing for symptomatic sinus arrest at 3 months, and another underwent atrioventricular node ablation followed by permanent pacing due to recurrent arrhythmia. The remaining patients had no related symptoms or need for pacing during follow‐up. Conclusion PSP ≥ 3 s upon AF termination shortly after catheter ablation appears to be reversible. A watch‐and‐wait strategy was practical. Management may involve discontinuation of antiarrhythmic drugs or temporary pacing support. A small proportion of patients may ultimately require permanent PMI. Twelve of the 1330 patients who underwent AF catheter ablation showed PSP ≥ 3 s after AF termination post ablation. The temporal characteristics of PSP were described. Nine of the 12 patients had no need for permanent pacing. We concluded that a ‘watch‐and‐wait’ strategy could be adopted in these patients.

Background To assess the clinical outcomes after endovascular thrombectomy (EVT) in elderly large vessel occlusion (LVO)-related acute ischemic stroke (AIS) patients with atrial fibrillation (AF). Methods Between January 2019 and December 2020, consecutive AF patients who received EVT due to anterior-circulation stroke were enrolled. The primary outcome was modified Rankin scale (mRS) score at 90 days. Secondary outcomes included all-cause mortality, the recanalization status after EVT (assessed using modified thrombolysis in cerebral infarction scale, mTICI) and any intracranial hemorrhage (ICH). A multivariate logistic regression model was performed to identify predictors of the functional outcome. Results A total of 148 eligible patients were finally enrolled. Among them, 42 were ≥ 80 years old. Compared to their younger counterparts, patients aged ≥80 years had lower likelihood of good functional outcome (mRS score 0–2) at 90 days (26.2% vs. 48.1%, P  = 0.015), less satisfied recanalization (mTICI, 2b-3) (78.6% vs. 94.3%, P  = 0.004) and higher all-cause mortality rate (35.7% vs. 14.2%, P  = 0.003). A multivariable logistic regression analysis showed that age ≥ 80 years at baseline were the significant predictors for a poor functional outcome (OR: 3.72, 95% CI: 1.17–11.89, p  = 0.027). Intravenous thrombolysis (IVT) prior to EVT and longer time intervals from onset of symptoms to EVT tended to be associated with poor functional outcome in patients ≥80 years old. Conclusions Age ≥ 80 years was a significant predictor of unfavorable outcomes after EVT for AIS patients with AF. An increased risk of adverse events must be balanced against the benefit from EVT in elderly patients with AF.

The Backward Limb Spectrometer (BLS) onboard the Tiangong-2 (TG-2) space laboratory, the first spaceborne limb sounding instrument of China, was successfully launched on 15 September 2016, and its measurements of scattered photons of sunlight along the limb line-of-sight (LOS) in the 290–1000 nm range could be used to derive the vertical distribution of stratospheric ozone with high vertical resolution. Ozone profiles with a vertical resolution of one km in 10–40 km and 30–50 km were retrieved by the triplet and pair methods, respectively, and the ozone profiles retrieved by the BLS were compared with the ozone sounding data over four sounding stations. Meanwhile, the Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) version 2.5 (v2.5) stratospheric ozone profile product was also introduced for comparison. The retrieval results showed a good agreement with the ozone profiles of ozone sounding and the OMPS/LP v2.5 product, and the differences were basically within 25% above 20 km, while relatively larger differences occasionally occurred below 20 km. The case studies over four sites worldwide demonstrate that the BLS is capable of measuring stratospheric ozone profiles with high vertical resolution.