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Based on the organic geochemical data and the molecular and stable carbon isotopic compositions of natural gas of the Lower Permian Fengcheng Formation in the western Central Depression of Junggar Basin, combined with sedimentary environment analysis and hydrocarbon-generating simulation, the gas-generating potential of the Fengcheng source rock is evaluated, the distribution of large-scale effective source kitchen is described, the genetic types of natural gas are clarified, and four types of favorable exploration targets are selected. The results show that: (1) The Fengcheng Formation is a set of oil-prone source rocks, and the retained liquid hydrocarbon is conducive to late cracking into gas, with characteristics of high gas-generating potential and late accumulation; (2) The maximum thickness of Fengcheng source rock reaches 900 m. The source rock has entered the main gas-generating stage in Penyijingxi and Shawan sags, and the area with gas-generating intensity greater than 20×108 m3/km2 is approximately 6 500 km2. (3) Around the western Central Depression, highly mature oil-type gas with light carbon isotope composition was identified to be derived from the Fengcheng source rocks mainly, while the rest was coal-derived gas from the Carboniferous source rock; (4) Four types of favorable exploration targets with exploration potential were developed in the western Central Depression which are structural traps neighboring to the source, stratigraphic traps neighboring to the source, shale-gas type within the source, and structural traps within the source. Great attention should be paid to these targets.

The Junggar Basin is known for its high potential of petroleum resources, showcasing significant oil and gas discoveries across various layers. However, the potential of utilizing the thick mudstone of the Upper Triassic as a viable source rock in the basin remains uncertain. Therefore, an urgent need exists to assess the Upper Triassic source rock across the basin and predict the distribution of effective source rocks. This evaluation is crucial for informing future exploration strategies in this layer. To shed light on the spatiotemporal distribution characteristics and hydrocarbon generation potential of the Upper Triassic source rocks in the Junggar Basin, as well as to determine the hydrocarbon generation intensity within the effective hydrocarbon kitchen's distribution range, a comprehensive evaluation was conducted. This evaluation involved assessing organic matter abundance, type, and maturity of the Upper Triassic source rock across the basin using various geochemical parameters derived from data collection, profile measurement, drill cuttings observation and sampling, and organic geochemistry testing. Key parameters were then selected, and a multi-level fuzzy mathematical evaluation method was employed to map out the development range of the effective hydrocarbon kitchen. The findings indicate that the Upper Triassic source rock exhibits a broad distribution range spanning the entire basin, with considerable thickness (reaching up to 350 m) and significant burial depth in the central region (up to 11 000 m). The total organic carbon (TOC) content of source rocks varies from 0.75% to 8.30%, with an average value of 1.74%. Additionally, the average values of S1+S2 and chloroform asphalt "A" are 2.78 mg/g and 0.354%, respectively. The predominant organic matter types in the area are type Ⅲ and type Ⅱ2, indicating a dominance of terrestrial higher plant inputs. The favorable kerogen types are primarily located from the western sag to the Fukang Sag. The thermal evolution of the organic matter ranges from low-maturity to mature stages, with some areas reaching high to over-maturity levels. As per the evaluation criteria for hydrocarbon generation potential of coal-bearing mudstone in China, the Upper Triassic mudstone generally represents poor to medium-quality source rocks with significant hydrocarbon generation potential, particularly for gas. The key hydrocarbon source kitchens are situated from the western part of the Fukang Sag to the eastern part of the Shawan Sag in the central depression, and in the Huomatu Anticline of the southern margin thrust belt. Within these areas, the Ro value of the source rock exceeds 1.3%, with oil and gas generation intensities reaching 50×104 t/km2 and 3×108 m3/km2, respectively.

Abstract 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

Background This study aimed to investigate the predictive value of parameters of every precordial lead and their combinations in differentiating between idiopathic ventricular arrhythmias (IVAs) from the right ventricular outflow tract and aortic sinus of Valsalva (ASV). Methods and Results Between March 1, 2018, and December 1, 2021, consecutive patients receiving successful ablation of right ventricular outflow tract or ASV IVAs were enrolled. The amplitude and duration of the R wave and S wave were measured in every precordial lead during IVAs. These parameters were either summed, subtracted, multiplied, or divided to create different indexes. The index with the highest area under the curve to predict ASV IVAs was developed, compared with established indexes, and validated in an independent prospective multicenter cohort. A total of 150 patients (60 men; mean age, 45.3±16.4 years) were included in the derivation cohort. The RV1+RV3 index (summed R‐wave amplitude in leads V1 and V3) had the highest area under the curve (0.942) among the established indexes. An RV1+RV3 index >1.3 mV could predict ASV IVAs with a sensitivity of 95% and a specificity of 83%. Its predictive performance was maintained in the validation cohort (N=109). In patients with V3 R/S transition, an RV1+RV3 index >1.3 mV could predict ASV IVAs, with an area under the curve of 0.892, 93% sensitivity, and 75% specificity. Conclusions The RV1+RV3 index is a simple and novel criterion that accurately differentiates between right ventricular outflow tract and ASV IVAs. Its performance outperformed established indexes, making it a valuable tool in clinical practice.

The discovery of Carboniferous hydrocarbon source rocks in the Mahu-Shawan Sag has implied considerable exploration potential in the Carboniferous strata in the western Junggar Basin. However, controversy has long surrounded when and how the Junggar Ocean was eventually closed, leading to a poor understanding of the Carboniferous basin evolution and the continental growth of the Central Asian Orogenic Belt. We performed stratigraphic and geochronologic studies to establish the chronostratigraphic framework of the western Junggar Basin to better understand its tectonic-sedimentary evolution during the Carboniferous-Early Permian. Three tectonostratigraphic units in the southern West Junggar region have been identified as Early Carboniferous shallow-deep marine sequences, Late Carboniferous coast-shallow marine sequences, and Early Permian continental sequences. The Carboniferous strata are similar to forearc and backarc-rift sequences in the Western Fault Belt and the Mahu-Shawan Sag, respectively. The Lower Permian strata in the southern West Junggar region are all continental sequences. Seismic profiles indicate extensional settings in the early stage of Late Carboniferous and Early Permian but a compressional setting at the end of Late Carboniferous. Geochemical data have suggested a Carboniferous continental arc setting and an Early Permian within-plate extensional setting. Meanwhile, calc-alkaline arc magma migrated from the Zhongguai High to the Western Fault Belt at the end of the Late Carboniferous. Collectively, the tectonic-sedimentary evolution in the Carboniferous-Early Permian of the southern West Junggar region can be divided into three stages: 1) Early Carboniferous subduction, 2) Late Carboniferous slab roll-back, and 3) Early Permian intra-continental evolution stage. This model constrains the closure of the Junggar Ocean at the Late Carboniferous.

The Carboniferous volcanic reservoirs in the Shixi area of the Junggar Basin are complex and diverse. Identifying the characteristics and main factors controlling high-quality volcanic reservoirs is the key to increasing oil and gas reserves and production in this area. Through core observations, thin section identification, physical property and pore structure analyses, combined with production data, the main controlling factors and development modes of high-quality reservoirs were analysed. The results show that the Carboniferous strata in the Shixi area mainly contain andesite and dacite of overflow facies, followed by volcanic breccia and tuff of explosive facies. Volcanic reservoirs in the study area are high-porosity–low-permeability and medium-porosity–low-permeability reservoirs. Volcanic breccia of explosive facies has the best physical properties, showing the characteristics of high porosity and medium permeability. The reservoir space is mainly composed of gas cavities, corrosion pores and fractures, among which the corrosion pores are the most important reservoir spaces of the Carboniferous volcanic rocks. Lithology and lithofacies, weathering and corrosion, and fractures are the main factors controlling the development of high-quality volcanic reservoirs. Volcanic rocks that had experienced weathering and denudation for a long time developed a large number of secondary corrosion pores due to the corrosion of soluble minerals or volcanic ash. Fractures further improved the physical properties, causing volcanic rocks to eventually develop into weathering crust reservoirs. The physical properties of the volcanic rocks far away from the weathering crust were improved through primary gas cavities and structural fractures, and these volcanic rocks eventually developed into the inner reservoir.

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.

To assess the prevalence and management of atrial thrombus in patients with nonvalvular atrial fibrillation (NVAF) and identify the risk factors of the nonresolution of atrial thrombus. This single-center retrospective observational study consecutively enrolled patients with NVAF and atrial thrombus detected using transesophageal echocardiography (TEE) or cardiac computed tomography angiography (CTA) from January 2012 to December 2020. Patients with prior left atrial appendage (LAA) intervention were excluded. The primary endpoint was the presence of atrial thrombus, while the secondary endpoint was the complete resolution of atrial thrombus. The prevalence of atrial thrombus in patients with NVAF was 1.4%. Ninety patients with atrial thrombus (mean age 62.8 ± 11.9 years and 61.1% men) were finally analyzed. Atrial thrombus was in the LAA in 82 (91.1%) patients. During follow up, 60% of the patients showed complete resolution of atrial thrombus. Congestive heart failure (odds ratio [OR]: 8.94; 95% confidence interval [CI]: 1.67-47.80) and a history of ischemic stroke (OR: 8.28; 95% CI: 1.48-46.42) were independently associated with the risk of the nonresolution of atrial thrombus. The presence of atrial thrombus in patients with NVAF who received anticoagulation therapy is non-negligible. Even in anticoagulated patients, TEE or cardiac CTA might still be needed. Congestive heart failure and a history of ischemic stroke are risk factors of the nonresolution of atrial thrombus.

Abstract 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.

BackgroundPulmonary vein isolation (PVI) is the standard ablation strategy for treating atrial fibrillation (AF). However, the optimal strategy of a repeat procedure for PVI non-responders remains unclear.ObjectiveThis study aims to investigate the incidence of PVI non-responders in patients undergoing a repeat procedure, as well as the predictors for the recurrence of repeat ablation.MethodsA total of 276 consecutive patients who underwent repeat ablation from August 2016 to July 2019 in two centers were screened. A total of 64 (22%) patients with durable PVI were enrolled. Techniques such as low voltage zone modification, linear ablation, non-PV trigger ablation, and empirical superior vena cava (SVC) isolation were conducted.ResultsAfter the 20.0 ± 9.9 month follow-up, 42 (65.6%) patients were free from atrial arrhythmias. A significant difference was reported between the recurrent and non-recurrent groups in non-paroxysmal AF (50 vs. 23.8%, p = 0.038), diabetes mellitus (27.3 vs. 4.8%, p = 0.02), and empirical superior vena cava (SVC) isolation (28.6 vs. 60.5%, p = 0.019). Multivariate regression analysis demonstrated that empirical SVC isolation was an independent predictor of freedom from recurrence (95% CI: 1.64–32.8, p = 0.009). Kaplan-Meier curve demonstrates significant difference in recurrence between empirical and non-empirical SVC isolation groups (HR: 0.338; 95% CI: 0.131–0.873; p = 0.025).ConclusionAbout 22% of patients in repeat procedures were PVI non-responders. Non-paroxysmal AF and diabetes mellitus were associated with recurrence post-re-ablation. Empirical SVC isolation could potentially improve the outcome of repeat procedures in PVI non-responders.

Abstract Background Accelerated idioventricular rhythm (AIVR) is often transient, considered benign and requires no treatment. This observational study aims to investigate the clinical manifestations, treatment, and prognosis of frequent AIVR. Methods Twenty-seven patients (20 male; mean age 32.2 ± 17.0 years) diagnosed with frequent AIVR were enrolled in our study. Inclusion criteria were as follows: (1) at least three recordings of AIVR on 24-h Holter monitoring with an interval of over one month between each recording; and (2) resting ectopic ventricular rate between 50 to 110 bpm on ECG. Electrophysiological study (EPS) and catheter ablation were performed in patients with distinct indications. Results All 27 patients experienced palpitation or chest discomfort, and two had syncope or presyncope on exertion. Impaired left ventricular ejection fraction (LVEF) was identified in 5 patients, and LVEF was negatively correlated with AIVR burden (P

BackgroundThere is a paucity of data about VAs clustered at the vicinity of the basal septum of the ventricle. We aimed to report and characterize the clinical and electrophysiological features of basal septum VAs and explore the systematic ablation approach.MethodsA consecutive series of 51 patients who had their VAs successfully ablated at the basal septum of the ventricle was enrolled in this study. The basal septum was defined as the area 2 cm away from the septal annulus, the upper boundary was the site of the left or right His-Purkinje system, and the lower boundary was the borderline that separated away from the septum. RFCA was performed based on detailed activation mapping or pace mapping. Patients who underwent VA ablation from other areas of the tricuspid annulus (TA) and mitral annulus (MA) during the same period were enrolled as the control group.ResultsThe patients with basal septum VAs were significantly older (p < 0.01) and had more comorbidities (hypertension and coronary artery disease) (p < 0.01). Meanwhile, the precordial R wave transition was significantly different in right side, left side and intramural foci group (p < 0.001). Acute procedural success was achieved in 44 patients (86.3%) in the study group and in 63 patients (95.5%) in the control group. After a median of 12 (6–36) months of follow-up, compared with VA recurrence in the control group (2 cases), 11 patients with basal septum VAs had recurrences (p = 0.002), while a delayed cure was observed in 3 in intramural foci group.ConclusionBased on the unique anatomical and electrophysiological characteristics, a systematic approach for VAs originating from the basal septal area is warranted. Moreover, the follow-up data seemed to show a relative high recurrence rate for basal septal VAs during a period of time.

To investigate the mechanisms of deep oil–gas accumulation in superimposed basins in western China, and identify deep oil–gas reserves in the Junggar Basin, this study examined Carboniferous reservoirs in the Central Depression of the basin. We determined the hydrocarbon physical properties and geochemical characteristics, and controlling factors on hydrocarbon accumulation in the deep part of the Central Depression. We present a geological model of oil–gas accumulation based on analog modeling of reservoir formation. The deep hydrocarbons in the study area are mainly light–medium oil and wet natural gas, which were mainly derived from Permian and Carboniferous source rocks. The hydrocarbon source rocks and their thermal evolution led to hydrocarbon accumulation in the study area. Adjacent source–reservoir rocks on both sides of faults were key to vertical hydrocarbon migration and multi-stage charging. Suitable reservoir–cap rock assemblages were also important for reservoir preservation. The hydrocarbon accumulation model involves a source–reservoir link along faults, late charging, and paleo-uplifts. The reservoir types include those linked to source rocks by large-scale faults and those in paleo-uplifts surrounded by oil-generating depressions, which both have good exploration prospects. This accumulation model may be applicable to deep parts of other superimposed basins.

The characteristics and genesis of the calcite veins in Carboniferous basalt in the east slope of Mahu Sag, Junggar Basin are investigated based on observation of cores and thin sections; analyses of X-ray fluorescence, in situ major, trace and rare earth elements (REE), carbon, oxygen and strontium isotopes, fluid inclusions, as well as basin modeling. There are three periods of calcite fillings. The Period I calcite is characterized by low Mn content, flat REE pattern, strong negative cerium (Ce) anomaly, weak to moderate negative Eu anomaly, and light carbon isotopic composition, indicating the formation of the calcite was affected by meteoric water. The Period II calcite shows higher Mn and light REE contents, weak positive Ce anomaly and slight positive europium (Eu) anomaly, and a little heavier carbon isotopic composition and slightly lower strontium isotope ratio than the Period I calcite, suggesting that deep diagenetic fluids affected the formation of the Period II calcite to some extent. The Period III calcite is rich in iron and manganese and has REE pattern similar to that of the Period II calcite, but the cerium and europium enomalies vary significantly. The Period I and II calcites were formed in shallow diagenetic environment at approximately 250–260 Ma, corresponding to Late Hercynian orogeny at Late Permian. The Period III calcite was probably formed in the Indo-China movement during Late Triassic. It is believed that the precipitation of calcite in basalt fractures near unconformity was related to leaching and dissolution of carbonates in the overlying Lower Permian Fengcheng Formation by meteoric water, which destructed the Carboniferous weathering crust reservoirs in early stage. Relatively high quality reservoirs could be developed in positions with weak filling and strong late dissolution, such as structural high parts with Fengcheng Formation missing, distant strata from Fengcheng Formation vertically, buried hills inside lake basin, etc.

PRKAG2 cardiomyopathy is a rare progressive disease characterized by increased ventricular wall thickness and preexcitation. Dysfunction of the protein 5′-AMP-activated protein kinase (AMPK) plays a decisive role in the progression of ventricular lesions. Although patients with the PRKAG2-R302Q mutation have a high incidence of atrial fibrillation (AF), the molecular mechanism contributing to the disease remains unclear. We carried out whole-genome sequencing with linkage analysis in three affected members of a family. Atrial samples were obtained from the proband via surgical intervention. Control atrium biopsies were obtained from patients with persistent AF. Pathological changes were analyzed using the hematoxylin and eosin (H&E), Masson, and periodic acid–Schiff (PAS) staining. The AMPK signaling pathway was investigated by western blot. A murine atrial cardiomyocyte cell line (HL-1) and human induced pluripotent stem derived atrial cardiomyocytes (hiPSC-ACMs) were transfected with an adenovirus carrying the same mutation. We used enzyme linked immunosorbent assay (ELISA) to determine the AMPK activity in HL-1 cells and hiPSC-ACMs overexpressing PRKAG2-R302Q. Pathological results showed a large quantity of glycogen accumulation and vacuolization in cardiomyocytes from the proband atrial tissue. Western blot analysis revealed that the AMPK activity was significantly downregulated compared with that of the controls. Furthermore, remarkable glycogen deposition and impairment of AMPK activity were reproduced in HL-1 cells overexpressing PRKAG2-R302Q. Taken together, PRKAG2-R302Q mutation directly impair atrial cardiomyocytes. PRKAG2-R302Q mutation lead to glycogen deposition and promote the growth of atrial lesions by disrupting the AMPK pathway.

BackgroundLeft anterior fascicle (LAF) premature ventricular contractions (PVC) are rarely reported. We described the electrocardiographic and electrophysiological characteristics of PVCs originating from LAF and evaluated the results of catheter ablation.MethodsThe baseline AH and HV intervals were recorded during normal sinus rhythm (NSR), and the HV interval of LAF-PVC was measured during the procedure. During the index procedure, the conduction interval from the earliest Purkinje potential (PP) site to the His was labeled as time A, the conduction interval from the earliest site to the onset of the QRS as time B, then the HV interval during NSR (HVNSR) is A + B, and the HV interval during PVC (HVPVC) is B-A; a predicted PP time was calculated using HVNSR and HVPVC. The calculated formula is as follows: Predicted target PP = (HVNSR + HVPVC)/2. During the repeat procedure, the mapping strategy only focuses on the earliest retrograde PP due to the injury or block of LAF sustained at the index procedure.ResultsNotably, 24 patients with LAF-PVC were included. The ECG characteristics of PVC exhibited right bundle branch block (RBBB) morphology with right-axis deviation (RAD) in 18 patients and only RAD in 6 patients. The QRS durations of NSR and PVC were 78.8 ± 7.9 and 106.8 ± 12.3 ms, respectively. There was no significant difference between the predicted and mapped PP site (31.5 ± 8.1 vs. 30.6 ± 7.8 ms; P = 0.17). There was a significant difference between the mean axis deviation before and after ablation (46.3 ± 25.4° vs. 18.3 ± 44.1°; P = 0.001); however, only 10 patients had a complete LAF block. Eight patients had a recurrence, the QRS morphology of LAF-PVC became narrower (95.9 ± 17.2 vs. 105.3 ± 16.9 ms, P = 0.003), and 4 patients’s PVC QRS morphology was similar to NSR. During the repeat procedure, the earliest retrograde PP interval was longer than the index procedure in four patients (12.0 ± 1.9 vs. 37.8 ± 1.1 ms; P < 0.001).ConclusionThe target PP site for ablation of the LAF region can be calculated using the HV interval during NSR and PVC at the index procedure. The mapping strategy at repeat procedures focused on the earliest retrograde PP interval.

Background: New-onset atrial fibrillation (AF) after ablation of typical atrial flutter (AFL) is not rare. This study aimed to investigate the predictive value of electrocardiographic parameters on new-onset AF post-typical AFL ablation.Methods: A total of 158 consecutive patients (79.1% males, mean age 57.8 ± 14.3 years) with typical AFL were enrolled between January 2012 and August 2017 in this single-center study. Patients with a history of AF before ablation were excluded. ECGs during sinus rhythm (SR) and AFL were collected. The duration of the negative component of flutter wave in lead II (DFNII), proportion of the DFNII of the total circle length of AFL (DFNII%), amplitude of the negative component of flutter wave in lead II (AFNII), duration (DPNV1), and amplitude (APNV1) of negative component of the P wave in lead V1, and P wave duration in lead II (DPII) during sinus rhythm were measured.Results: During a median follow-up of 26.9 ± 11.8 months, 22 cases (13.9%) developed new-onset AF. DFNII was significantly longer in patients with new-onset AF compared to patients without AF (114.7 ± 29.6 ms vs. 82.7 ± 12.8 ms, p < 0.0001). AFNII was significantly lower (0.118 ± 0.034 mV vs. 0.168 ± 0.051 mV, p < 0.0001), DPII (144.21 ± 23.77 ms vs. 111.46 ± 14.19 ms, p < 0.0001), and DPNV1 was significantly longer (81.07 ± 16.87 ms vs. 59.86 ± 14.42 ms, p < 0.0001) in patients with new-onset AF. In the multivariate analysis, DFNII [odds ratio (OR), 1.428; 95% CI, 1.039–1.962; p = 0.028] and DPII (OR, 1.429; 95% CI, 1.046–1.953; p = 0.025) were found to be independently associated with new-onset AF after typical AFL ablation.Conclusion: Parameters representing left atrial activation time under both the SR and AFL were independently associated with new-onset AF post-typical AFL ablation and may be useful in risk prediction, which needs to be confirmed by further prospective studies.

Land surface temperature (LST) is an important parameter in determining surface energy balance and a fundamental variable detected by the advanced geostationary radiation imager (AGRI), the main payload of FY-4A. FY-4A is the first of a new generation of Chinese geostationary satellites, and the detection product of the satellite has not been extensively validated. Therefore, it is important to conduct a comprehensive assessment of this product. In this study, the performance of the FY-4A LST product in the Hunan Province was authenticity tested with in situ measurements, triple collocation analyzed with reanalysis products, and impact analyzed with environmental factors. The results confirm that FY-4A captures LST well (R = 0.893, Rho = 0.915), but there is a general underestimation (Bias = −0.6295 °C) and relatively high random error (RMSE = 8.588 °C, ubRMSE = 5.842 °C). In terms of accuracy, FY-4A LST is more accurate for central-eastern, northern, and south-central Hunan Province and less accurate for western and southern mountainous areas and Dongting Lake. FY-4A LST is not as accurate as Himawari-8 LST; its accuracy also varies seasonally and between day and night. The accuracy of FY-4A LST decreases as elevation, in situ measured LST, surface heterogeneity, topographic relief, slope, or NDVI increase and as soil moisture decreases. FY-4A LST is also more accurate when the land cover is cultivated land or artificial surfaces or when the landform is a platform for other land covers and landforms. The conclusions drawn from the comprehensive analysis of the large quantity of data are generalizable and provide a quantitative baseline for assessing the detection capability of the FY-4A satellite, a reference for determining improvement in the retrieval algorithm, and a foundation for the development and application of future domestic satellite products.

The Junggar Basin, where twenty-seven oil fields and five gas fields have been discovered, is a typical “oil basin” with proven ratio of natural gas of 5.3%. The amount of natural gas from Permian source rocks has been found in the western margin of the basin, but no large-scale natural gas reservoir has been discovered. The key to natural gas exploration is whether Permian oil-prone source rocks have large gas generation potential. Based on the comprehensive analysis of geochemical features and hydrocarbon generation simulation experiments, it is proved that the gas generation intensity could meet the standard of medium to large gas-fields (20 × 108 m3/km2) at a depth of more than 6500 m. In the Penyijing and Shawan Sags, the burial depth of the Fengcheng Formation source rocks is between 8500 m and 10,000 m, respectively. It could be concluded that the Permian source rocks in the Penyijingxi and Shawan Sags have relative higher gas generation potential. In addition to high natural gas generation potential, two sets of effective reservoirs (wreathing volcanic rocks and secondary dissolution of sandy conglomerates) and thick caprocks with overpressure are developed in the most areas of Junggar Basin. Recently, natural gas reservoirs have been discovered and industrial natural gas had been obtained around the Penyijingxi Sag, Shawan Sags, and the Southern margin of the Junggar Basin. Our research results and natural gas exploration practice show that the Junggar Basin have relatively large natural gas exploration potential.

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.

Peripheral blood mononuclear cells (PBMCs) were harvested and reprogramed to induced pluripotent stem cells (iPSCs) from a 46-year-old male patient with familial dilated cardiomyopathy and atrial fibrillation via a non-integrating system. A missense mutation in the LMNA gene (c.1003C > T) was identified by whole-exome sequencing and verified by Sanger sequencing. The pluripotency, differentiation potential, and karyotype of this cell line were also tested. This model is helpful to study the phenotype, mechanism, and therapy for laminopathy.

Element exchange and enrichment during fluid-rock interactions are common, providing potentially novel proxies to trace hydrocarbon migration in addition to the traditional organic geochemistry tracers. However, the processes, mechanisms, and geological and geochemical fingerprints of these interactions are complex, hampering the applications of hydrocarbon migration tracers. To investigate such interactions, we conducted a petrological, mineralogical, and in situ and bulk geochemical study of authigenic quartz and whole-rock samples from the Mahu Sag, northwestern Junggar Basin, northwest China. We found that dissolution, clay and chlorite formation, and overgrowth occurred on quartz grains in hydrocarbon fluid migration pathways, suggestive of strong fluid-rock interactions. In situ quantitative elemental analysis of quartz grains revealed elemental enrichment (e.g., Mn, Fe, Al, Sr, and W) in quartz overgrowth rims compared with their cores, indicating that migration of hydrocarbon-bearing fluids in reservoirs may promote elemental exchange between fluids and minerals. Whole-rock geochemical analysis showed that decreasing contents of some elements may reflect the direction of hydrocarbon-bearing fluid migration and can be monitored with three geochemical proxies, which are the MnO contents and MnO/Zr and Y/Ho ratios. Our data provide new constraints on fluid-rock interactions in petroleum reservoirs and have implications for using inorganic geochemical methods to trace hydrocarbon migration.

Six machine-learning approaches, including multivariate linear regression (MLR), gradient boosting decision tree, k-nearest neighbors, random forest, extreme gradient boosting (XGB), and deep neural network (DNN), were compared for near-surface air-temperature (Tair) estimation from the new generation of Chinese geostationary meteorological satellite Fengyun-4A (FY-4A) observations. The brightness temperatures in split-window channels from the Advanced Geostationary Radiation Imager (AGRI) of FY-4A and numerical weather prediction data from the global forecast system were used as the predictor variables for Tair estimation. The performance of each model and the temporal and spatial distribution of the estimated Tair errors were analyzed. The results showed that the XGB model had better overall performance, with R2 of 0.902, bias of −0.087°C, and root-mean-square error of 1.946°C. The spatial variation characteristics of the Tair error of the XGB method were less obvious than those of the other methods. The XGB model can provide more stable and high-precision Tair for a large-scale Tair estimation over China and can serve as a reference for Tair estimation based on machine-learning models.

The spatial and temporal distribution characteristics of high clouds over the Tibetan Plateau (TP) were studied using the Atmospheric Infrared Sounder (AIRS) and the GCM-Oriented CALIPSO Cloud Product (CALIPSO-GOCCP) monthly mean cloud products from 2007 to 2017. The high clouds over the TP are dominated by cirrus and show seasonal variation characteristics. There were two distinct areas with the high occurrence of cirrus clouds in the area (0°–60°N, 75°–103°E). One was located in the regions from the equator to 25°N, and the other was within the latitude belt from 30° to 40°N. From January to May, cirrus clouds mainly occurred in the central and northern parts of the TP (30° to 40°N), and the cirrus cloud fraction increased from January and reached its maximum (∼0.51) in April. From June to August, cirrus clouds mainly occurred in the southern part of the TP during summer. The cirrus clouds over the southern TP were relatively high (located in 10–17 km) and manifested northward and southward movements. The ice clouds in the southern TP are associated with plateau deep convection activities and abundant vapor transmitted by the Asian monsoon. Cirrus clouds over the northern and central TP may be relevant to the atmospheric lift by an approaching cold front and topographic lifting. Moreover, the high clouds below 11 km are dominated by opaque clouds, while the nonopaque (or thin) and opaque (or thick) clouds above 11 km are comparable.

This study proposed an instantaneous summer air temperature (Tair) estimation model using the Himawari-8 Advanced Himawari Imager (AHI) brightness temperatures (BTs) in split-window channels and other auxiliary data. Correlation analysis and stepwise linear regression were used to select the predictors for Tair estimation. Nine predictors such as AHI BTs in channels 14 and 15, elevation, precipitable water vapor (PWV), and relative humidity (RH) were finally selected. Stepwise linear regression and neural network (NN) methods were applied to construct summer Tair estimation models over China, respectively. The estimated Tair by linear and NN models was evaluated using the observed Tair from 272 meteorological stations over China. The results showed that AHI BTs in channels 14 and 15, elevation, PWV, and RH were more important for Tair estimation than other predictors. The accuracy of the NN models was better than the linear models. The correlation coefficient (R), root mean square error (RMSE), and bias were 0.97, 1.72°C, and 0.04°C, respectively, for the NN model and were 0.89, 3.28°C, and 0.07°C, respectively, for the linear model. About 75.6% of the Tair differences by the NN model were within 2.0°C, and even 45.8% were within 1.0°C. The performance of the Tair estimation model for each site was also investigated, and the accuracy of Tair estimation in southeast China is better than northwest China.

The superior vena cava (SVC) is the main component of non-pulmonary vein (PV) ectopy in patients with atrial fibrillation (AF). Researchers have found that epicardial adipose tissue (EAT) volume is related to the AF substrate, which can be defined by the low voltage area (LVA). This study aimed to investigate the relationship between SVC-EAT and SVC-AF. Twenty-six patients with SVC-AF triggers were identified as the SVC-AF group. Other three groups were defined and included as the LVA-AF group (LVA>5%), non-LVA-AF group (LVA<5%), and physical examination (PE) group. EAT around left atrium (LA-EAT) and SVC-EAT volumes were obtained using a cardiac risk assessment module. According to the SVC/LA-EAT ratio, there are significant differences between the SVC-AF group and the three control groups (the SVC-AF group 0.092±0.041 vs. the LVA-AF group 0.054±0.026, the non-LVA-AF group 0.052±0.022, and the PE group 0.052±0.019, all P<0.001). Receiver operating characteristic curve analysis suggests the optimal cut-off point of SVC/LA-EAT ratio is 6.8% for detecting SVC-AF patients, with 81.1% sensitivity, 73.1% specificity, and an area under the curve of 0.83 (95% confidence interval, 0.75-0.91). Those with SVC-AF have a higher SVC/LA-EAT ratio and empirical SVC isolation could be considered if the SVC/LA-EAT ratio was over 6.8%. [ABSTRACT FROM AUTHOR]

Several satellites have been launched to monitor the increasing concentrations of greenhouse gases, especially CO2 and CH4 in the atmosphere, through back-scattered hyperspectral radiance in the shortwave infrared (SWIR) band. The vertical profiles of greenhouse gases and aerosol could strongly affect the results from these instruments. To investigate the effects of the vertical distribution of CO2 on uncertainty in SWIR satellite retrieval results, we conducted observations of the vertical profiles of CO2, CH4, and aerosol particles at 0.6–7 km above sea level using a Beechcraft King Air 350ER in Jiansanjiang (46.77° N, 131.99° E), Heilongjiang province, Northeast China, on August 7–12, 2018. The profiles from this aircraft captured a decrease in CO2 from 2 km to the minimum altitude due to uptake from vegetation at the surface in summer. CH4 measurements showed an average 0.5 ppm increase from 2.0 to 0.6 km, which may result from emissions from the large area of paddy fields below, and a constant mole fraction between 1.951 and 1.976 ppm was recorded at 2 km and above. Comparison of CO2 profiles from a new version of the carbon cycle data assimilation system Tan-Tracker (v1), retrievals from OCO-2 and aircraft measurements was conducted. The results from OCO-2 and the assimilation model system Tan-Tracker captured the vertical structure of CO2 above 3 km, whereas below 3 km, the values from OCO-2 and Tan-Tracker model were lower than those from in situ measurements. Column-averaged CO2 volume mixing ratios calculated from in situ measurements showed biases of −2.39 ± 2.02 ppm and −0.61 ± 0.49 % compared to OCO-2 retrievals. [ABSTRACT FROM AUTHOR]

In this paper, we choose SCITRAN 3.2 model simulates Limb radiance. Study on SCIATRAN3.2 model structure and the atmospheric radiation theory, choose clouds as the object of the study. From the geometry of spaceborne Limb scattering observation technique we set radiance simulation environment. On this basis, select the range of the values and develop simulation programs, radiance simulation and make sure the results are correct. According to the simulation results, we analyze the sensitivity of Limb radiance. Results show that tangent height is Limb radiance sensitive factor. Radiance with band and tangent point height varies. The results show that cloud is Limb radiance sensitive factor. Water clouds and ice clouds effect differently, vary with the bands and the tangent point height. [ABSTRACT FROM AUTHOR]

Recent studies have shown that premature ventricular contractions (PVCs) could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular (LV) function in patients with PVCs by 7-day Holter electrocardiography (ECG). From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors' affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal probrain natriuretic peptide (NT-proBNP) levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction (EF) level and a lower LV end-systolic dimension (ESD) than other PVC foci (P<0.05). The high burden group had a higher LV end-diastolic dimension (EDD) and LVESD but lower LVEF than the other two groups (P<0.05). Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction. [ABSTRACT FROM AUTHOR]