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• Proposed A new fluid technology for EOR in heterogeneous reservoirs. • The fluid can actively plug high-permeability areas to divert flooding agents. • The surfactant and polymer components in the fluid can enhance overall EOR effects. • The fluid system contains no solid phase, which minimizes formation damage. Conventional water flooding and polymer flooding are common approaches to improve oil recovery. However, flooding agents injected into heterogeneous reservoirs preferentially enter the seepage channels in high-permeability zones. As a result, it is difficult to displace the hydrocarbons in low-permeability areas. Therefore, using the agents with selective plugging capability to block the high-permeability channels and promote the subsequent displacement in the low-permeability area has become a potentially preferable solution for enhanced oil recovery (EOR) in heterogeneous reservoirs. In this study, the techniques and mechanisms of the novel fuzzy-ball fluid for enhancing oil recovery in heterogeneous reservoirs are discussed. Laboratory tests were conducted using 45 mm × 45 mm × 300 mm artificial cores with permeability ranging from 200 to 1200 mD to simulate the formation channels. Two cores with different permeabilities were connected in parallel to simulate the heterogeneous formations. The oil displacement performance of fuzzy-ball fluid was compared with that of polymer and surfactant fluids. Flooding the cores with fuzzy-ball fluid could significantly increase the oil recovery rate of the low-permeability cores. Field tests were conducted in two polymer injection wells located in a heterogeneous conglomerate reservoir in Karamay Oilfield, China. After fuzzy-ball fluid flooding, the average daily liquid production rate decreased, the average daily oil production rate increased and the overall water content decreased. There was a significant improvement in oil displacement effect in low-permeability areas. [ABSTRACT FROM AUTHOR]

Background: Circumferential pulmonary vein isolation (CPVI) often cause unavoidable vagal reflexes during procedure due to the coincidental modification of ganglionated plexus which are located on pulmonary vein (PV) antrum. The right anterior ganglionated plexi (RAGP) which located at superoanterior area of right superior PV antrum is an essential station to regulate the cardiac autonomic nerve activities and is easily coincidentally ablated during CPVI. The aim of this study is to assess the effect of RAGP ablation on vagal response (VR) during CPVI.Methods: A total of 80 patients with paroxysmal atrial fibrillation who underwent the first time CPVI were prospectively enrolled and randomly assigned to 2 groups: group A (n=40), CPVI started with right PVs at RAGP site; group B (n=40): CPVI started with left PVs first, and the last ablation site is RAGP. Electrophysiological parameters include basal cycle length, A-H interval, H-V interval, sinus node recovery time, and atrioventricular node Wenckebach point were recorded before and after CPVI procedure.Results: During CPVI, the positive VR were only observed on 1 patient in group A and 25 patients in group B (P<0.001). A total of 21 patients with positive VR in group B needed for temporary ventricular pacing during procedure, while the only patient with positive VR in group A did not need for temporary ventricular pacing (P<0.001). Compared with baseline, basal cycle length, sinus node recovery time, and atrioventricular node Wenckebach point were decreased significantly after CPVI procedure in both groups (all P<0.05) and without differences between 2 groups.Conclusions: Circumferential PV isolation initiated from RAGP could effectively inhibit VR occurrence and significantly increase heart rate during procedure. [ABSTRACT FROM AUTHOR]

Introduction: Sepsis-associated acute kidney injury (SA-AKI) is strongly associated with poor prognosis. We aimed to build a machine learning (ML)-based clinical model to predict 1-year mortality in patients with SA-AKI. Methods: Six ML algorithms were included to perform model fitting. Feature selection was based on the feature importance evaluated by the SHapley Additive exPlanations (SHAP) values. Area under the receiver operating characteristic curve (AUROC) was used to evaluate the discriminatory ability of the prediction model. Calibration curve and Brier score were employed to assess the calibrated ability. Our ML-based prediction models were validated both internally and externally. Results: A total of 12,750 patients with SA-AKI and 55 features were included to build the prediction models. We identified the top 10 predictors including age, ICU stay and GCS score based on the feature importance. Among the six ML algorithms, the CatBoost showed the best prediction performance with an AUROC of 0.813 and Brier score of 0.119. In the external validation set, the predictive value remained favorable (AUROC = 0.784). Conclusion: In this study, we developed and validated a ML-based prediction model based on 10 commonly used clinical features which could accurately and early identify the individuals at high-risk of long-term mortality in patients with SA-AKI. [ABSTRACT FROM AUTHOR]

Protein glutaminase (PG; EC 3.5.1.44) is a novel deamidase that helps to improve functional properties of food proteins. Currently, the highest activated PG enzyme activity was 26 U/mg when recombinantly expressed via the twin-arginine translocation (Tat) pathway in Corynebacterium glutamicum. In this study, superfolder green fluorescent protein (sfGFP) was used to replace traditional signal peptides to facilitate efficient heterologous expression and secretion of Propeptide-Protein glutaminase (PP) in Bacillus subtilis. The fusion protein, sfGFP-PP, was secreted from 12 h of fermentation and reached its highest extracellular expression at 28 h, with a secretion efficiency of about 93 %. Moreover, when fusing sfGFP with PP at the N-terminus, it significantly enhances PG expression up to 26 U/mL by approximately 2.2-fold compared to conventional signal-peptides- guided PP with 11.9 U/mL. Finally, the PG enzyme activity increased from 26 U/mL to 36.9 U/mL after promoter and RBS optimization. This strategy not only provides a new approach to increase PG production as well as extracellular secretion but also offers sfGFP as an effective N-terminal tag for increased secreted production of difficult-to-express proteins. [ABSTRACT FROM AUTHOR]

The self-healing cement used in oil wells aims to provide long-term interlayer isolation by enabling the cement system to repair itself. This paper compared the absorption properties of 2-acrylamido-2-methyl propanesulfonic acid (AMPS)-based superabsorbent polymer (SAP) and acrylic acid (AA)-based SAP in water and cement slurry filtrate. The effect of cement slurry filtrate on the water absorption properties of the two SAPs was evaluated. The results showed that the calcium ions in the cement slurry would crosslink with the carboxyl groups in the AA-SAP, increasing the crosslink density and greatly reducing its absorption rate in water. Compared to AA-SAP, AMPS-SAP is more suitable for oil well cement slurries. AMPS-SAP can help reduce the fluid loss of cement slurry. The addition of 0.4% AMPS-SAP in cement slurry results in a 64 mL decrease in fluid loss. The properties (rheological properties, thickening time, and compressive strength) of cement slurry meet the requirements for well cementing construction. [ABSTRACT FROM AUTHOR]

Long-term zonal isolation is crucial for the development of fossil hydrogen energy, while efficient filter cake removal is the basis for successful zonal isolation. However, enhanced filter cake removal usually relies on adding chemicals into preflush fluid, which are potential pollutants to the environment. In this study, engineering parameter optimization is used to realize enhanced filter cake removal. Firstly, filter cake removal was identified as multiple-phase fluid flow, and a new three-fluid numerical model was established accordingly. The effects of five engineering parameters on the removal efficiency were simulated and the results showed that borehole enlargement and casing eccentricity reduced removal efficiency. The critical borehole deviation angle and casing rotation speed for optimal removal efficiency were 45° and 40 rpm, respectively, while the removal efficiency monotonously increased with flushing velocity. After all engineering parameters were optimized, the maximum removal efficiency was as high as 89.34%, which was comparable to that achieved by using potentially polluting chemicals. The borehole enlargement rate was identified as the most sensitive parameter, followed by casing eccentricity, flushing velocity, borehole deviation angle, and casing rotation speed subsequently. Two empirical models to predict removal efficiency were developed for convenient field application. Briefly, the complex removal behaviors of the filter cake are better understood for reducing the risks of failed zonal isolation and avoiding chemical overuse, which potentially contributes to the cleaner and more environment-friendly production of fossil hydrogen energy. [Display omitted] • Filter cake removal in the annulus is considered as a fluid flow problem. • Empirical models are to predict removal efficiency for practice. • Borehole enlargement rate is the most sensitive engineering parameter. • After engineering parameter optimization, removal efficiency can reach 89.34%. • Removing filter cake by engineering parameter optimization is an eco-friendly way. [ABSTRACT FROM AUTHOR]

Purpose: Increased vagal activity plays a prominent role in vasovagal syncope (VVS). The aim of this study was to characterize vagal function in VVS by evaluating the heart rate (HR) deceleration capacity (DC) and the HR deceleration runs (DRs) in patients with VVS between attacks. Methods: A total of 188 consecutive VVS patients were enrolled in the study, of whom 129 had positive head-up tilt test (HUTT); 132 healthy participants were enrolled as controls. DC, DRs (DR2, i.e., episodes of 2 consecutive beat-to-beat HR decelerations), and the sum of DR8-10 (very long DR [VLDR]) were calculated using 24-h electrograms. Clinical characteristics, DC, and DRs were compared among syncope groups and controls. Results: Patients with VVS had higher DC (10.63 ± 2.1 vs. 6.58 ± 1.7 ms; P < 0.001) and lower minimum HR and DR6-10 than controls. No significant differences in DC or DR6-10 were found between the patients with positive and those with negative HUTT results. In multivariate logistic regression analysis, minimum HR ≥ 40 bpm (odds ratio [OR] 0.408, 95% confidence interval [CI] 0.167–0.989; P = 0.048), daytime DC ≥ 7.37 ms (OR 3.040, 95% CI 1.220–7.576; P = 0.013), and VLDR ≥ 0.046% (OR 0.306, 95% CI 0.138–0.679; P = 0.004) were demonstrated to be risk factors significantly associated with VVS. Conclusion: Compared to healthy controls, patients with VVS demonstrated distinct HR deceleration profiles between attacks, including overall higher DC and lower DR6-10. [ABSTRACT FROM AUTHOR]

Background. Limited randomized controlled studies showed that thoracoscopic surgical left atrial ablation was not superior to catheter ablation (CA) in patients with persistent atrial fibrillation (PerAF). Right atrium might play an important role in triggering and maintaining atrial fibrillation (AF) in patients with PerAF. This study aimed to compare the efficacy of thoracoscopic surgical biatrial ablation versus CA in patients with PerAF. Methods. Patients with PerAF underwent thoracoscopic surgical biatrial ablation or CA were included in this study. Propensity score matching (1 : 2) was applied to select patients in CA group and surgical ablation (SA) group. The primary endpoint was to compare the probability of freedom from atrial tachyarrhythmias between SA and CA. Atrial tachyarrhythmia recurrence was defined as any atrial tachyarrhythmias longer than 30 s documented by 24-hour Holter monitoring after the 3-month blanking period. Results. After propensity score matching, 51 patients in surgical biatrial ablation group and 102 patients in CA group were enrolled (mean left atrial diameter: 45.8 mm). The probability of freedom from atrial tachyarrhythmias on antiarrhythmia drugs was 62.7%, 60.6%, and 60.6% in SA group and 42.0%, 39.6%, and 36.7% in CA group at 12, 24, and 36 months, respectively (p = 0.011), and off antiarrhythmia drugs were 56.9%, 52.5%, and 52.5% in SA group and 36.0%, 31.4%, and 27.5% in CA group at 12, 24, and 36 months, respectively (p = 0.007). After adjustment of age, sex, left atrial diameter, and AF duration history, multivariable Cox regression analysis suggested that SA procedure was an independent factor to reduce the risk of atrial tachyarrhythmia recurrence (HR: 0.589, 95% CI 0.370–0.937, p = 0.025). Conclusion. Compared with CA, thoracoscopic surgical biatrial ablation might achieve superior effectiveness for patients with PerAF. [ABSTRACT FROM AUTHOR]

The carbonate reservoir in the northern Yishan slope of the Ordos Basin presents significant challenges to gas field exploration and development. With its low pressure, limited porosity, low permeability, and abundance of micro-fractures, the reservoir is resistant to acid dissolution. Once solid particles block these fractures during drilling and completion, serious reservoir damage ensues. To address these obstacles, we engineered an acid-soluble, solid-free drilling fluid system in the lab. This involved incorporating sodium carboxymethyl cellulose, heat-resistant starch, fungicides, and lubricants. Contrasted with the commonly used potassium ammonium based drilling fluid system, our innovative solution showed notable improvements. Specifically, the density decreased by 0.04 to 0.06 g/cm3, and the solid content decreased by 4.0% to 6.50%, while the acid-soluble rate surged from 8.50% to 95.45%. In addition, the reservoir permeability recovery value saw an increase from 51.50% to 95.88%. In practical field application, we employed this novel drilling fluid system in ten horizontal wells. Following acid fracturing and reconstruction, these wells registered a 75.94% increase in gas production compared to nearby wells. Our findings demonstrate that the proposed system effectively mitigates the incursion of solid-phase particles into the reservoir while enhancing acidification during acid fracturing. This results in the swift removal of plugging, restoration of formation permeability, and improved well production. Our research thus introduces a drilling and completion fluid system of high efficiency with superior reservoir protection performance, potentially offering substantial benefits to the development of carbonate rock salt gas reservoirs. [ABSTRACT FROM AUTHOR]

The detection of underwater targets through hyperspectral imagery is a relatively novel topic as the assumption of target background independence is no longer valid, making it difficult to directly detect underwater targets using land target information. Meanwhile, deep-learning-based methods have faced challenges regarding the availability of training datasets, especially in underwater conditions. To solve these problems, a transfer-based framework is proposed in this paper, which exploits synthetic data to train deep-learning models and transfers them to real-world applications. However, the transfer becomes challenging due to the imparity in the distribution between real and synthetic data. To address this dilemma, the proposed framework, named the transfer-based underwater target detection framework (TUTDF), first divides the domains using the depth information, then trains models for different domains and develops an adaptive module to determine which model to use. Meanwhile, a spatial–spectral process is applied prior to detection, which is devoted to eliminating the adverse influence of background noise. Since there is no publicly available hyperspectral underwater target dataset, most of the existing methods only run on simulated data; therefore, we conducted expensive experiments to obtain datasets with accurate depths and use them for validation. Extensive experiments verify the effectiveness and efficiency of TUTDF in comparison with traditional methods. [ABSTRACT FROM AUTHOR]

Bottom hole flowing pressure (BHFP) is the key factor to determine a reasonable working system and achieve long-term stable production of coalbed methane (CBM) wells. However, there is no special BHFP model for double-layer combined production (DLCP). Generally, the constant mass model (CMM) for single-layer production is applied to treat the double reservoirs as a whole, ignoring the changes of fluid mass in each section and the acceleration pressure drop in the reservoir section. The calculation results have great errors, and the BHFP of the lower reservoir is used to adjust the production system of the two reservoirs, which does not meet the requirements of the upper reservoir. In this paper, the expression of acceleration pressure drop assumed to be zero in CMM is decomposed and derived, the relationship between acceleration pressure drop and unit length radial flow is established, and then the pressure drop formula of reservoir section with radial inflow is obtained. The reservoir is divided into several sublayers, and the pressure drop equation for each sublayer is established. According to the water flow and gas flow in the reservoir and nonreservoir sections, the corresponding velocity equations of water phase and gas phase are derived. The above equations are combined to establish the variable mass model (VMM) for DLCP with three stages. The field data are substituted into the VMM and the CMM, and the accuracy of the new model is verified. The results show that in the stages of double-layer water production and double-layer gas production, the errors of the two models are less than 5%, while in the stage of gas-water coproduction, the error of the VMM is 2.75%-6.58%, and the error of the CMM is 7.15%-15.18%. The VMM is more accurate. In addition, in the stages of water production and gas-water coproduction during DLCP, the BHFP of the two reservoirs differs greatly, with a maximum difference of 49.1%. Therefore, the two reservoirs need to adjust the production rule according to their respective BHFP. To sum up, the VMM can accurately give the BHFP of each reservoir, which is more realistic. It also solves the problem that one BHFP cannot accurately adjust the production rule of the two reservoirs, so as to provide technical support for the formulation of optimal production rule and the realization of high production. [ABSTRACT FROM AUTHOR]

Oil well cement microcracks cause formation fluid channeling, compromising oil and gas extraction safety. Superabsorbent polymer (SAP) can absorb water and swell to prevent fluid channeling. In this study, an alkali-resistant and pH-sensitive SAP was prepared based on the properties of oil well cement slurry. The preparation of the SAP was optimized, including monomer ratio, cross-linking agent dosage, and monomer concentration. The pH sensitivity and alkali resistance of the SAP were evaluated. The results revealed that the SAP exhibited good pH sensitivity, with the absorption rate in water being 2.18 times that of cement slurry filtrate (CSF) at 95 °C. Furthermore, the FTIR spectrum showed that the SAP had a stable molecular structure. The secondary absorption rate in water of the SAP after soaking in CSF was not different from the original absorption rate. Styrene–butadiene latex (SBL) can be used to adjust the SAP's absorption rate. The SAP's absorption rate had a good exponential functional relationship with SBL dosage. The SBL dosage can be determined by the functional relationships to prepare a SAP with the required properties. [ABSTRACT FROM AUTHOR]

Workover of natural gas wells in deep carbonate gas reservoirs (DCRs) is facing multiple challenges such as fluid leakage, high temperature, and hydrogen sulfide (H2S) gas kick. Hence, well‐killing fluids with satisfactory plugging ability, high‐temperature tolerance, and anti‐H2S ability are necessary. In this study, we developed a multifunctional anti‐hydrogen sulfide fuzzy‐ball kill fluid (AFKF) for preventing sour gas kicks in DCRs. The performance of the AFKF was optimized and analyzed via experiments and verified through a case study application. The results showed that the fuzzy‐ball structures in the AFKFs demonstrated good stability under extreme H2S aging. The rate of change of certain critical rheological parameters such as apparent viscosity, dynamic plastic ratio, and density of AFKFs before and after hot rolling were no more than 5%. After plugging the fractures with the AFKFs at temperatures between 110°C and 150°C, the inlet driving pressure of the fractures increased from 20.73°C to 21.07 MPa, and no fluid loss was observed at the core outlet after a secondary displacement of formation water. The permeability recovery rate was greater than 90%. Application of AFKF in well DW‐2 showed that the shut‐in pressure rose to 24.6 MPa with no trace of H2S gas at the wellhead after 4 days. The investigation of the H2S mitigation mechanisms revealed that the plugging of the seepage channels by AFKFs forms interconnected bonds that improve the mechanical properties of the reservoir. Additionally, AFKFs absorb H2S gases by protonation and dissociation reactions which convert the hazardous gas into an aqueous solution of sulfide ions (S2−). The proposed AFKF has proven to be effective means of mitigating H2S in DCRs, and minimize the negative impacts of environmental polution, health risks, and equipment corrosion. [ABSTRACT FROM AUTHOR]

The oxidation reaction between charge and water for photocatalyst has restricted overall water splitting efficiency. Herein, the non-noble-metal Ni 3 C acting as an electron sink were selectively deposited onto Mn 2 O 3 on faceted BiVO 4 via electrostatic self-assembly, synergistically creating faceted heterostructure with dual internal electric field (IEF) for photocatalytic water oxidation. Resultantly, a remarkable visible light-driven photocatalytic O 2 evolution rate was observed to be 2736.5 μmol g−1 h−1 with an apparent quantum yield of 5.57 % at 400 nm. The significantly improved activity mainly stemmed from the giant dual IEF, dramatically accelerating exciton separation and prolonging the lifetime of charge carriers. Moreover, the photocatalysts without activity attenuation were considerably stable and reused with recyclability utilizing the magnetic nature in practical application. By combining with the self-induced IEF by exposed {001} facet of BiVO 4 for improving photocatalytic activity, this work could throw light on the design of faceted heterostructure in solar energy conversion application. [Display omitted] • The recyclable Ni 3 C/Mn 2 O 3 /faceted BiVO 4 heterostructure is fabricated via electrostatic self-assembly. • Dual internal electric field with facet regulation is beneficial for the carrier transfer and separation. • The Ni 3 C/Mn 2 O 3 /faceted BiVO 4 shows an impressive photocatalytic O 2 evolution rate of 2736.5 μmol g−1 h−1. • The experimental perspective combined with the micro level clarify improved photocatalytic mechanism. [ABSTRACT FROM AUTHOR]

• Permeability measurement is for evaluating CBM formation damage by working fluids. • Statistical screening algorithm is developed for screening. • Cuttings pulse decay method is optimal. • Constant flowrate method is also acceptable. • The suitability relies on CBM characteristics and measurement principles. The existing laboratory methods have limitations that make it very difficult to select the most suitable method for obtaining precise permeability measurements for evaluating reservoir formation damage. To date, there has been no research critically addressing this issue. In this study, the permeabilities of core or cuttings samples taken from No.15 Reservoir in the Qinshui Basin before and after damage caused by drilling and fracturing fluids were randomly measured using six general laboratory methods. Their average permeability values, as well as the extent of absolute and relative formation damage, were calculated and analyzed using a simple ranking method, statistical screening algorithm, and theoretical method. The results show that, first, there is a regular distribution of absolute reservoir damage measured by the laboratory methods; and second, the application priority of permeability measurement methods for formation damage evaluation in coal bed methane reservoirs is as follows: cuttings pulse decay method > constant flow rate method > nuclear magnetic resonance method > plunger pulse decay method = pressure oscillation method = constant pressure method. The cuttings pulse decay method is therefore recommended for measuring core matrix damage, while the constant flow rate method is suggested for measuring overall damage to core samples. [ABSTRACT FROM AUTHOR]

Refracturing is one of the most effective techniques to enhance the production of tight sandstone gas (TSG) well. Many TSG gas wells are facing the problem of water invasion after refracturing, the formation water may gradually occupy the gas-producing channels, preventing high gas productivity. In this paper, we newly developed a fuzzy-ball temporary plugging fluid (FTPF) with diverting fractures and water cutting after refracturing in one operation. The temporary plugging and water breakthrough control capabilities of the FTPF system were evaluated through the true triaxial large-scale core diversion fracturing experiment and matrix core and artificial fracture waterproof experiments. Meanwhile, the permeability damage evaluation experiments were performed to analyze the reservoir recovery ability. Results showed that the pressure-bearing capacity could reach up to 62.6 MPa, the rock fracture pressure was increased by 5–10 MPa compared with the initial hydraulic fracturing and an apparent fracture network structure was formed after refracturing. The breakthrough pressure gradients of simulated formation water were 2–10 times higher than that of nitrogen after the cores (including matrix and cores with 4 mm fractures) were plugged with FTPF, indicating its good water cutting ability. Before and after gel breaking, the permeability recovery value of the matrix core and the artificial fracture core was about 85–98%. The on-site application of FTPF to the refracturing of two TSG wells in the Sulige Gas Field in Northwest of China displayed that the average gas production has been enhanced by 64.8%. It is proposed that fuzzy balls can easily enter and gather at the tip of the initial fractures and form a stable pressure-bearing structure due to its viscoelastic properties and deformability. In addition, the hydrophilic fuzzy-ball core agents can adsorb on the rock's surface and form a polymer membrane, increasing the resistance of water flow. [Display omitted] • Temporary plugging with diverting fractures and water control after refracturing were performed in one operation. • The plugging and pressure-bearing capacity of fuzzy-ball fluid were evaluated. • The breakthrough pressure gradients of water and gas to the plugging structures were compared. • The tight sandstone gas well production has been enhanced compared with the adjacent wells. • The mechanism of enhancing natural gas production via fuzzy-ball fluid has been discussed. [ABSTRACT FROM AUTHOR]

Tight gas reservoirs are characterized by multiple thin and vertically distributed development layers with similar or different lithology and varying geological conditions. To increase the production per well and reduce development costs, field experts have widely adopted the commingled production of tight gas in multi-layer reservoirs. However, differences in reservoir properties and pressure might lead to interlayer interference which could influence the overall wellhead output. In this study, we propose a mathematical model for predicting the overall wellhead output of single and multi-layer tight gas reservoirs after interlayer interference. A reservoir(a) and process factor(b) were deduced to quantitatively analyze the difference in interlayer interference. The range and accuracy of the model were analyzed through a goodness-of-fit test. The results showed that the interlayer interference in multi-layer commingled production systems with three or more layers was decreasing, and the interlayer interference in multi-layer commingled production systems with three or more layers was not significantly affected by the increment of layers, the accuracy of the model was greater than 80% and closer to the lower limit of the process and reservoir factors. The model will provide a quantitative method for predicting interlayer interference in multi-layer commingled production, a reliable basis for understanding the mechanism of interlayer interference, and a theoretical framework for evaluating the feasibility of commingled production in multi-layer tight gas reservoirs. • A quantitative model for predicting the overall wellhead output of single- and multilayer gas reservoirs was proposed. • The interlayer interference of commingled productions were systematically studied by experiments and theories. • The interlayer interference of multi-layer commingled production systems with three or more layers is decreasing. • It provides a reliable basis for understanding the mechanism of interlayer interference, and the accuracy is greater than 80%. [ABSTRACT FROM AUTHOR]

Conventional industry standards (CIS) or methods that rely on the permeability indicator are incapable of directly and precisely evaluating the working fluid damage in multi-layer reservoirs as a whole via Darcy equation and fail to represent the characteristics of gas flow through the reservoir under an in-situ stress state. In this study, we proposed a flow rate method that was based on theoretical derivation and test parameter optimization to overcome these deficiencies. The rationality of the proposed method was verified through comparative experiments and field case analyses. Results showed that the instantaneous flow rate index was almost equivalent to permeability in characterizing the degree of working fluid damage. Comparing the classification of damage degree with the skin factor, the CIS method was only with a conformity of 25%, while the instantaneous flow rate method was as high as 90%. Although the practicality of the cumulative flow rate index has not been proven, it could be used to comprehensively measure the production loss over a specified period. In conclusion, the proposed flow rate method can effectively reflect the actual reservoir properties and accurately evaluate the overall damage of commingled production reservoirs, then providing better guidance for future development plans. [Display omitted] • Flow rate is feasible for evaluating reservoir damage during commingled production. • Flow rate is a preferred parameter over permeability for multi-layer overall damage. • Optimized test parameters present stress characteristics of different reservoirs. • Flow rate method conforms with skin factor method from well test. [ABSTRACT FROM AUTHOR]

Background: Nonrheumatic valvular heart disease (NRVD) is increasingly becoming a significant public health concern, particularly among older people. In the context of population aging, a detailed report on the epidemiological trends of NRVD is crucial for policymakers to effectively allocate health care resources. This study aimed to explore these trends using data from the GBD (Global Burden of Disease) 2019 study., Methods and Results: We assessed the changing trends of the incidence, mortality, and disability-adjusted life years rates for NRVD by calculating the estimated annual percentage change for each. Additionally, we examined the impact of a region's level of social development on NRVD epidemiological trends and identified key risk factors contributing to NRVD-related deaths. Between 1990 and 2019, the global incidence of NRVD showed a gradual increase, with an estimated annual percentage change of 0.39 (95% CI, 0.30-0.48). The data revealed that women and older people are more likely to develop NRVD. High-sociodemographic index countries exhibited higher age-standardized incidence and mortality rates compared with low- and middle-sociodemographic index countries. The most significant risk factor for NRVD-related mortality was identified as high systolic blood pressure., Conclusions: Over the past 3 decades, the burden of NRVD has intensified, indicating a need for more health care resources to address this issue, which is closely associated with an aging population. Currently, high-sociodemographic index countries report the highest incidences and deaths due to NRVD. However, low- and middle-sociodemographic index countries should also implement measures to manage the rapidly increasing burden of NRVD.

Background: Ventricular arrhythmias commonly originate from the ventricular outflow tract (VOT). It remains unexplored whether pulsed-field ablation (PFA) can create durable lesions safely at the VOT., Objective: This study aimed at evaluating the feasibility and safety of a novel PFA catheter to deliver focal ablation to the VOT, especially pulmonary and aortic sinus cusps (PSCs and ASCs)., Methods: Twelve swine were divided into three groups: 24-hour, 2-week, and 4-week post-ablation. PFA was delivered to pre-defined sites of PSCs and ASCs with a focal point catheter, positioned via mapping system, fluoroscopy, and intracardiac echocardiography (ICE). Electrophysiologic assessment, coronary angiography, transesophageal echocardiogram (TEE), gross and histologic examination were performed to evaluate the impact of PFA delivery on cardiac structure and function., Results: All subjects survived, and no adverse events were observed. There was a significant decrease in voltage amplitude and increase in pacing thresholds at PSCs and ASCs. There were no significant differences in A-H or H-V intervals between pre- and post-ablation (A-H, P = .70; H-V, P = .90). After PFA delivery to ASCs, coronary arteries were fully perfused in each heart, without ST-segment elevation observed. No severe valvular dysfunction was observed based on ICE and TEE. Gross and histologic examination confirmed the creation of well-demarcated lesions at the targeted sites without damage to adjacent structures., Conclusion: PFA delivered via the focal point catheter could create durable lesions at PSCs and ASCs without damage to coronary arteries, atrioventricular block, or valvular dysfunction, indicative of the feasibility and safety of this novel PFA catheter at the VOT., (Copyright © 2024. Published by Elsevier Inc.)

Background: The implantable cardioverter-defibrillator (ICD) prevents sudden cardiac death in patients with ischemic cardiomyopathy (ICM). Catheter ablation has been shown to effectively reduce ventricular tachycardia (VT) recurrence, yet its efficacy in patients without an ICD implantation remains uncertain., Objective: We aimed to investigate the outcomes of ablation for VT in patients with ICM without a backup ICD., Methods: Patients with ICM who received ablation for VT without an ICD implantation were included in this study. Ablation was guided by either activation mapping or substrate mapping. Endocardial ablation was the primary strategy; epicardial access was considered when endocardial ablation failed. The primary end point was VT recurrence during follow-up; secondary end points included cardiovascular rehospitalization, all-cause mortality, and a composite of these events., Results: A total of 114 patients were included, with the mean age of 58.2 ± 11.1 years, 102 of whom (89.5%) were male. Twelve patients (10.5%) underwent endo-epicardial ablation, whereas the rest received endocardial ablation. With a median follow-up of 53.8 months (24.8-84.2 months), VT recurred in 45 patients (39.5%), and 6 patients (5.3%) died, including 2 sudden cardiac deaths. The recurrence rate of VT was significantly lower in patients undergoing endo-epicardial ablation than in those with endocardial ablation only (8.3% vs 43.1%; log-rank P = .032). After multivariate adjustment, epicardial ablation remained associated with a reduced risk of VT recurrence (hazard ratio, 0.14; 95% confidential interval, 0.02-0.98; P = .048)., Conclusion: Patients with ICM undergoing VT ablation without a backup ICD experienced a notably low rate of arrhythmic death. Most recurrences proved nonlethal., Competing Interests: Disclosures The authors declare no conflicts of interest., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Left ventricular hypertrabeculation (LVHT) is a heterogeneous entity with life-threatening complications and variable prognosis. However, there are limited prediction models available to identify individuals at high risk of adverse outcomes, and the current risk score in LVHT is comparatively complex for clinical practice. This study aimed to develop and validate a simplified risk score to predict major adverse cardiovascular events (MACE) in LVHT., Methods: This multicenter longitudinal cohort study consecutively enrolled morphologically diagnosed LVHT patients between January 2009 and December 2020 at Fuwai Hospital (derivation cohort, n = 300; internal validation cohort, n = 129), and between January 2014 and December 2022 at two national-level medical centers (external validation cohort, n = 95). The derivation/internal validation cohorts and the external validation cohort were followed annually until December 2022 and December 2023, respectively. MACE was defined as a composite of all-cause mortality, heart transplantation/left ventricular assist device implantation, cardiac resynchronization therapy, malignant ventricular arrhythmia, and thromboembolism. A simplified risk score, the ABLE-SCORE, was developed based on independent risk factors in the multivariable Cox regression predictive model for MACE, and underwent both internal and external validations to confirm its discrimination, calibration, and clinical applicability., Results: A total of 524 LVHT patients (43.5 ± 16.6 years, 65.8% male) were included in the study. The ABLE-SCORE was established using four easily accessible clinical variables: age at diagnosis, N-terminal pro-brain natriuretic peptide levels, left atrium enlargement, and left ventricular ejection fraction ≤ 40% measured by echocardiography. The risk score showed excellent performance in discrimination, with Harrell's C-index of 0.821 [95% confidence interval (CI), 0.772-0.869], 0.786 (95%CI, 0.703-0.869), and 0.750 (95%CI, 0.644-0.856) in the derivation, internal validation, and external validation cohort, respectively. Calibration plots of the three datasets suggested accurate agreement between the predicted and observed 5-year risk of MACE in LVHT. According to decision curve analysis, the ABLE-SCORE displayed greater net benefits than the existing risk score for LVHT, indicating its strength in clinical applicability., Conclusions: A simplified and efficient risk score for MACE was developed and validated using a large LVHT cohort, making it a reliable and convenient tool for the risk stratification and clinical management of patients with LVHT., (© 2024. The Author(s).)

Objective: There is no consensus on the optimal ablation strategy for nonparoxysmal atrial fibrillation (NPAF) with enlarged left atrium. We aimed to explore whether hybrid ablation (HA) of combined thoracoscopic surgical ablation with catheter ablation (CA) was superior to CA alone in these patients., Methods: Patients with NPAF and left atrial diameter (LAD) ≥45 mm who underwent hybrid biatrial ablation or CA procedure from June 2014 to July 2021 were included in this study. Propensity score matching was applied to select patients in each group. The primary endpoint was freedom from atrial tachyarrhythmias after procedures., Results: After propensity score matching, 52 patients with enlarged left atrium (median LAD = 51 mm) were enrolled in each group. The median follow-up was 36 months. The probability of freedom from atrial tachyarrhythmias at 12, 24, and 36 months on antiarrhythmic drugs (AADs) was 70.1%, 65.4%, and 62.6% in the HA group and 34.3%, 29.4%, and 22.0% in the CA group, respectively ( P < 0.001); off AADs was 57.1%, 52.7%, and 50.0% in the HA group and 25.0%, 16.2%, and 11.5% in the CA group ( P < 0.001); on AADs after redo CA was 76.2%, 73.7%, and 73.7% in the HA group and 43.6%, 43.6%, and 38.2% in the CA group, respectively ( P < 0.001); off AADs after redo CA was 62.5%, 60.1%, and 60.1% in the HA group and 30.4%, 25.1%, and 20.9% in the CA group, respectively ( P < 0.001)., Conclusions: For patients with NPAF and enlarged left atrium, hybrid biatrial ablation was superior to CA in sinus rhythm maintenance even if redo CA was performed., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Aims: Advanced atrial fibrillation (AF) is currently a dilemma for electrophysiologists when choosing a minimally invasive treatment strategy. Previous studies have demonstrated the outcome of either catheter ablation or thoracoscopic surgical ablation (SA) is unsatisfactory in these patients. Whether hybrid ablation (HA) could improve outcomes in these patients is unknown. The purpose of this study was to evaluate the clinical efficacy of HA for the treatment of advanced AF., Methods and Results: A randomized controlled trial was designed to enrol patients with persistent AF (PerAF) and enlarged left atrium or long-standing persistent AF (LSPAF) who were randomized to HA or thoracoscopic SA at a 1:1 ratio. The primary endpoint was freedom from any recurrence of AF off antiarrhythmic drugs (AADs) 12 months after operation. The primary endpoint was monitored by 7-day electrocardiogram monitoring devices. One hundred patients were enrolled. The mean age was 58.5 ± 7.6 years, and the mean left atrial diameter (LAD) was 50.1 ± 6.1 mm. At 12 months, freedom from AF off AADs was recorded in 71.4% (35/49) of patients in HA group and 45.8% (22/48) in SA group [odds ratio 2.955, 95% confidence interval (1.275-6.848), P = 0.014]. HA significantly reduced patients' AF burden (30.2% in SA group and 14.8% in HA group, P = 0.048) and the LAD (mean differences: -5.53 ± 4.97 mm in HA group and -3.27 ± 5.20 mm in SA group, P = 0.037) at 12 months after operation., Conclusion: In patients with PerAF and enlarged left atrium or LSPAF, HA achieved better freedom from AF after 1 year of follow-up compared with thoracoscopic SA., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

The Balanophorae are not only traditional Chinese herbal medicines but also functional foods with diverse sources. This study aimed to distinguish pharmacognostic characteristics and secondary metabolites among different species of Balanophorae. Eight species of Balanophorae herbs were harvested, including 21 batches with 209 samples. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to analyze secondary metabolites of Balanophorae from 21 sources. Targeted metabolomic analysis was performed to compare differences among the groups. Rhopalocnemis phalloide and B. indica can be identified by their pharmacognostic characteristics. Then, 41 secondary metabolites were identified or characterized in the mixed extracts of the 209 samples, mainly phenolic acids, flavonoids, and their derivatives. The distribution of these secondary metabolites revealed apparent differences among different species. In addition, targeted metabolomic analysis suggested that the secondary metabolite profiles of seven species of Balanophorae showed noticeable differences, and differences were also observed among different growing regions. Finally, five important metabolic markers were screened to successfully distinguish B. laxiflora, B. harlandii, and B. polyandra, including three phenolic acids and two flavonoids. This is the first study to systematically compare both the morphology and secondary metabolites among different sources of Balanophorae, which could provide effective information for identifying diverse species., (© 2024. The Author(s).)

In the rapidly evolving landscape of Internet of Things (IoT), Zigbee networks have emerged as a critical component for enabling wireless communication in a variety of applications. Despite their widespread adoption, Zigbee networks face significant security challenges, particularly in key management and network resilience against cyber attacks like distributed denial of service (DDoS). Traditional key rotation strategies often fall short in dynamically adapting to the ever-changing network conditions, leading to vulnerabilities in network security and efficiency. To address these challenges, this paper proposes a novel approach by implementing a reinforcement learning (RL) model for adaptive key rotation in Zigbee networks. We developed and tested this model against traditional periodic, anomaly detection-based, heuristic-based, and static key rotation methods in a simulated Zigbee network environment. Our comprehensive evaluation over a 30-day period focused on key performance metrics such as network efficiency, response to DDoS attacks, network resilience under various simulated attacks, latency, and packet loss in fluctuating traffic conditions. The results indicate that the RL model significantly outperforms traditional methods, demonstrating improved network efficiency, higher intrusion detection rates, faster response times, and superior resource management. The study underscores the potential of using artificial intelligence (AI)-driven, adaptive strategies for enhancing network security in IoT environments, paving the way for more robust and intelligent Zigbee network security solutions., (© 2024. The Author(s).)

Introduction: Cather ablation (CA) is a well-recognized treatment alternative for atrial fibrillation (AF) patients despite more than 20% ablation-treated patients suffering from AF recurrence. The underlying mechanism of AF recurrence postablation is probably associated with high cardiac parasympathetic activity, which can be assessed with deceleration capacity (DC) of heart rate. Given that the relationship between DC and AF recurrence is still controversial, this systematic review and meta-analysis was performed to investigate the characteristics of DC in patients with and without AF recurrence, evaluating the prognostic value of DC in AF patients after CA., Methods: A literature search was systematically performed in the Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases until October 01, 2023. The observational studies reporting either the pre- and postablation DC in both recurrence and non-recurrence groups or the ratios based on DC for predicting AF recurrence were mainly included. Weighted mean differences (WMD) or odds ratios (OR) based on DC would be calculated with a random-effect model, if heterogeneity estimated with the I 2 index and Q statistic was significant (I 2  > 50% or p < .05); otherwise, a fixed-effect model would be utilized., Results: A total of eight observational studies involving 914 AF patients treated with radiofrequency or cryoballoon ablation were included in this study. Ablation-treated patients with AF recurrence had the higher DC postablation in relation to those without recurrence (WMD, 1.00; 95% confidence interval [CI], 0.33-1.67; p < .01), which was present up to 3 months of follow-up (WMD, 1.54; 95% CI, 1.11-1.96; p < .01), whereas there was no statistical significance in DC before ablation between recurrence and non-recurrence groups (WMD, 0.34; 95% CI, -0.12 to 0.79; p = .15). The high DC postablation was a risk factor for AF recurrence in ablation-treated patients (OR, 2.17; 95% CI, 1.44-3.25; p < .01)., Conclusion: The high DC postablation was associated with the risk of AF recurrence, suggesting that DC may act as a prognostic indicator in AF patients treated with CA., (© 2024 Wiley Periodicals LLC.)

Protein glutaminase (PG), originating from Chryseobacterium proteolyticum, can catalyze the deamidation of glutamine residues in plant proteins into glutamic acid, thus enhancing its functional properties. However, the low yield of PG limits its industrial production. In this study, the yield of PG in C. proteolyticum TM1040 increased by 121 %, up to 7.30 U/mL in a 15 L fermenter after medium optimization. Subsequently, purified PG was obtained by cation exchange chromatography (CEX) coupled with hydrophobic interaction chromatography (HIC). The degree of deamidation (DD) of wheat gluten after purified PG deamidation was 87.11 %, which is superior to chemical deamidation in safety and DD. The emulsifying and foaming properties of deamidated wheat gluten were 2.67 and 18.86 times higher, and the water- and oil-holding properties were 4.23 and 18.77 times higher, respectively. The deamidated wheat gluten with enhanced functional properties was used to improve the flavor and texture in baking cakes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Aims: Catheter ablation of ventricular tachycardia (VT) improves VT-free survival in 'classic' arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to investigate electrophysiological features and ablation outcomes in patients with ARVC and biventricular (BiV) involvement., Methods and Results: We assembled a retrospective cohort of definite ARVC cases with sustained VTs. Patients were divided into the BiV (BiV involvement) group and the right ventricular (RV) (isolated RV involvement) group based on the left ventricular systolic function detected by cardiac magnetic resonance. All patients underwent electrophysiological mapping and VT ablation. Acute complete success was non-inducibility of any sustained VT, and the primary endpoint was VT recurrence. Ninety-eight patients (36 ± 14 years; 87% male) were enrolled, including 50 in the BiV group and 48 in the RV group. Biventricular involvement was associated with faster clinical VTs, a higher VT inducibility, and more extensive arrhythmogenic substrates (all P < 0.05). Left-sided VTs were observed in 20% of the BiV group cases and correlated with significantly reduced left ventricular systolic function. Catheter ablation achieved similar acute efficacy between these two groups, whereas the presence of left-sided VTs increased acute ablation failure (40 vs. 5%, P = 0.012). Over 51 ± 34 months [median, 48 (22-83) months] of follow-up, cumulative VT-free survival was 52% in the BiV group and 58% in the RV group (P = 0.353). A multivariate analysis showed that younger age, lower RV ejection fraction (RVEF), and non-acute complete ablation success were associated with VT recurrence in the BiV group., Conclusion: Biventricular involvement implied a worse arrhythmic phenotype and increased the risk of left-sided VTs, while catheter ablation maintained its efficacy for VT control in this population. Younger age, lower RVEF, and non-acute complete success predicted VT recurrence after ablation., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: The stress hyperglycemia ratio (SHR) has been demonstrated as an independent risk factor for acute kidney injury (AKI) in certain populations. However, this relationship in patients with congestive heart failure (CHF) remains unclear. Our study sought to elucidate the relationship between SHR and AKI in patients with CHF., Methods: A total of 8268 patients with CHF were included in this study. We categorized SHR into distinct groups and evaluated its association with mortality through logistic or Cox regression analyses. Additionally, we applied the restricted cubic spline (RCS) analysis to explore the relationship between SHR as a continuous variable and the occurrence of AKI. The primary outcome of interest in this investigation was the incidence of AKI during hospitalization., Results: Within this patient cohort, a total of 5,221 (63.1%) patients experienced AKI during their hospital stay. Upon adjusting for potential confounding variables, we identified a U-shaped correlation between SHR and the occurrence of AKI, with an inflection point at 0.98. When the SHR exceeded 0.98, for each standard deviation (SD) increase, the risk of AKI was augmented by 1.32-fold (odds ratio [OR]: 1.32, 95% CI: 1.22 to 1.46). Conversely, when SHR was below 0.98, each SD decrease was associated with a pronounced increase in the risk of AKI., Conclusion: Our study reveals a U-shaped relationship between SHR and AKI in patients with CHF. Notably, we identified an inflection point at an SHR value of 0.98, signifying a critical threshold for evaluating AKI in this population., (© 2024. The Author(s).)

Background: Stress hyperglycemia has been associated with poor prognosis in patients admitted to the cardiac intensive care unit (ICU). Recently, the stress hyperglycemia ratio (SHR) has been proposed to reflect true acute hyperglycemic. This study aimed to investigate the relationship between SHR and prognosis of patients in the cardiac ICU., Methods: A retrospective analysis was conducted on a cohort of 5,564 patients admitted to the cardiac ICU. The participants were divided into seven groups based on their SHR levels. SHR was calculated as admission blood glucose/[(28.7 × HbA1c %) - 46.7]. The primary outcomes of this study were 28-day all-cause mortality., Results: During the follow-up period, 349 (6.3%) patients succumbed within 28 days. A U-shaped correlation between SHR and mortality persisted, even after adjusting for other confounding variables, with a discernible inflection point at 0.95. When SHR surpassed 0.95, each standard deviation (SD) increase corresponded to a 1.41-fold elevation in the risk of mortality (odds ratio [OR]: 1.41, 95% CI: 1.25 to 1.59). In contrast, when SHR fell below 0.95, each SD increment correlated with a significantly reduced risk of mortality (OR: 0.56, 95% CI: 0.34 to 0.91)., Conclusion: There was a U-shaped association between SHR and short -term mortality in patients in the cardiac ICU. The inflection point of SHR for poor prognosis was identified at an SHR value of 0.95., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Research Trust of DiabetesIndia (DiabetesIndia) and National Diabetes Obesity and Cholesterol Foundation (N-DOC). Published by Elsevier Ltd. All rights reserved.)

Background: Autoimmune myocarditis, with increasing incidence and limited therapeutic strategies, is in urgent need to explore its underlying mechanisms and effective drugs. Pyroptosis is a programmed cell death that may contribute to the pathogenesis of myocarditis. Nonetheless, no direct evidence validated the role of pyroptosis in autoimmune myocarditis. Lupeol (Lup), a pentacyclic triterpene, possesses various biological activities such as antidiabetic properties. However, the effects of Lup on autoimmune myocarditis and pyroptosis remain unelucidated., Purpose: This study aimed to reveal the role of pyroptosis in autoimmune myocarditis and explore the protective effects of Lup, and its engaged mechanisms., Methods: The experimental autoimmune myocarditis (EAM) mouse model was established by immunization with a fragment of cardiac myosin in Balb/c mice. Lup and MCC950 were administered after EAM induction. The protective effects were assessed by inflammation score, cardiac injury, chronic fibrosis, and cardiac function. Mechanistically, the effects of Lup on the M1 polarization and pyroptosis of macrophages were evaluated. Transcriptome sequencing and molecular docking were subsequently employed, and the underlying mechanisms of Lup were further explored in vitro with small interfering RNA and adenovirus., Results: Administration of Lup and MCC950 alleviated EAM progression. Western blotting and immunofluorescence staining identified macrophages as the primary cells undergoing pyroptosis. Lup inhibited the expression of pyroptosis-associated proteins in macrophages during EAM in a dose-dependent manner. Furthermore, Lup suppressed pyroptosis in both bone marrow-derived macrophages (BMDMs) and THP-1-derived macrophages in vitro. In addition, Lup inhibited the M1 polarization of macrophages both in vivo and in vitro. Mechanistically, the protective effects of Lup were demonstrated via the suppression of the nuclear factor-κΒ (NF-κB) signaling pathway. Transcriptome sequencing and molecular docking revealed the potential involvement of peroxisome proliferator-associated receptor α (PPARα). Subsequently, we demonstrated that Lup activated PPARα to reduce the expression level of LACC1, thereby inhibiting the NF-κB pathway and pyroptosis., Conclusion: Our findings indicated the crucial role of macrophage pyroptosis in the pathogenesis of EAM. Lup ameliorated EAM by inhibiting the M1 polarization and pyroptosis of macrophages through the PPARα/LACC1/NF-κB signaling pathway. Thus, our results provided a novel therapeutic target and agent for myocarditis., Competing Interests: Declaration of Competing Interest All authors declared that no relevant conflicts of interest exist in this study., (Copyright © 2023 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Aims: The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation., Methods and Results: A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012)., Conclusion: Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Catheter ablation of premature ventricular contractions (PVCs) that trigger polymorphic ventricular tachycardia (PVT) or ventricular fibrillation has been reported as a novel therapy to reduce the syncope events in patients with catecholaminergic PVT, whereas the long-term ablation outcome and its value in improving exercise-induced ventricular arrhythmias remain unclear., Methods and Results: Fourteen consecutive selected patients with catecholaminergic PVT (mean±SD age, 16±6 years; 43% male patients) treated with maximum β-blockers with no possibility of adding flecainide were prospectively enrolled for catheter ablation. The primary end point was syncope recurrence, and the secondary end point was the reduction of the ventricular arrhythmia score during exercise testing. Twenty-six PVT/ventricular fibrillation-triggering PVCs were identified for ablation. The trigger beats arose from the left ventricle in 50% of the cases and from both ventricles in 36% of the cases. Purkinje potentials were observed at 27% of the targets. After a mean follow-up of 49 months after ablation, 8 (57%) patients were free from syncope recurrence. Ablation of trigger beat significantly reduced the syncope frequency (mean±SD, 4.3±1.6 to 0.5±0.8 events per year; P <0.001) and improved the ventricular arrhythmia scores at the 3-month (5 [range, 3-6] to 1.5 [range, 0-5]; P =0.002) and 12-month (5 [range, 3-6] to 2 [range, 0-5]; P =0.014) follow-ups. The induction of nontriggering PVCs postablation was closely associated with syncope recurrence (hazard ratio, 6.8 [95% CI, 1.3-35.5]; P =0.026)., Conclusions: Catheter ablation of PVT/ventricular fibrillation-triggering PVCs in patients with catecholaminergic PVT who cannot receive flecainide treatment seems to be a safe and feasible adjunctive treatment that may reduce the syncope burden and improve exercise-related ventricular arrhythmias. Induction of nontriggering PVCs after ablation is associated with a higher risk of syncope recurrence.

Sinus node dysfunction is a multifaceted disorder with variable manifestations, the prevalence of which increases with age. In a specific group of patients, excessive vagal activity may be the sole cause for this condition. These patients are characterized as having recurrent daytime symptoms attributed to bradyarrhythmia, no evidence of organic sinus node lesions, cardiac vagal overactivation, and are non-elderly. For sinus node dysfunction patients, a permanent pacemaker implantation appears to be the ultimate solution, although it is not an etiological treatment. Cardioneuroablation is a promising emerging therapy that can fundamentally eliminate symptoms in a highly selective sub-set of sinus node dysfunction patients by cardiac vagal nerve denervation. Denervation with ablation for vagal-induced sinus node dysfunction can effectively improve sinus bradycardia and reduce syncope. To date, guidelines for selection of suitable candidates for cardioneuroablation remain lacking. The primary objective of this study was to distinguish the nature of abnormal sinus node function and to find methods for quantifying vagal tone. Clear selection criteria could help physicians in identification of patients with autonomic imbalance, thereby maximizing patient benefits and the success rate of cardioneuroablations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Cai, Zheng and Yao.)

The COVID-19 pandemic has severely impacted healthcare systems worldwide. This study investigated cardiologists’ opinions on how the COVID-19 pandemic impacted clinical practice patterns in atrial fibrillation (AF). A multicenter clinician survey, including demographic and clinical questions, was administered to 300 cardiologists from 22 provinces in China, in April 2022. The survey solicited information about their treatment recommendations for AF and their perceptions of how the COVID-19 pandemic has impacted their clinical practice patterns for AF. The survey was completed by 213 cardiologists (71.0%) and included employees in tertiary hospitals (82.6%) and specialists with over 10 years of clinical cardiology practice (53.5%). Most respondents stated that there were reductions in the number of inpatients and outpatients with AF in their hospital during the pandemic. A majority of participants stated that the pandemic had impacted the treatment strategies for all types of AF, although to different extents. Compared with that during the assumed non-pandemic period in the hypothetical clinical questions, the selection of invasive interventional therapies (catheter ablation, percutaneous left atrial appendage occlusion) was significantly decreased (all p < 0.05) during the pandemic. There was no significant difference in the selection of non-invasive therapeutic strategies (the management of cardiovascular risk factors and concomitant diseases, pharmacotherapy for stroke prevention, heart rate control, and rhythm control) between the pandemic and non-pandemic periods (all p > 0.05). The COVID-19 pandemic has had a profound impact on the clinical practice patterns of AF. The selection of catheter ablation and percutaneous left atrial appendage occlusion was significantly reduced, whereas pharmacotherapy was often stated as the preferred option by participating cardiologists., Competing Interests: The authors declare no conflicts of interest.

Background: The coronavirus disease 2019 (COVID-19) pandemic has severely affected healthcare systems around the world. This study aimed to investigate the perceptions of cardiologists regarding how the COVID-19 pandemic has affected the clinical practice patterns for acute coronary syndrome (ACS)., Methods: A multicenter clinician survey was sent to 300 cardiologists working in 22 provinces in China. The survey collected demographic information and inquired about their perceptions of how the COVID-19 pandemic has affected ACS clinical practice patterns., Results: The survey was completed by 211 (70.3%) cardiologists, 82.5% of whom were employed in tertiary hospitals, and 52.1% reported more than 10 years of clinical cardiology practice. Most respondents observed a reduction in ACS inpatients and outpatients in their hospitals during the pandemic. Only 29.9% of the respondents had access to a dedicated catheter room for the treatment of COVID-19-positive ACS patients. Most respondents stated that the COVID-19 pandemic had varying degrees of effect on the treatment of acute ST-segment elevation myocardial infarction (STEMI), acute non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina. Compared with the assumed non-pandemic period, in the designed clinical questions, the selection of coronary interventional therapy for STEMI, NSTEMI, and unstable angina during the COVID-19 pandemic was significantly decreased (all p < 0.05), and the selection of pharmacotherapy was increased (all p < 0.05). The selection of fibrinolytic therapy for STEMI during the pandemic was higher than in the assumed non-pandemic period ( p < 0.05)., Conclusions: The COVID-19 pandemic has profoundly affected ACS clinical practice patterns. The use of invasive therapies significantly decreased during the pandemic period, whereas pharmacotherapy was more often prescribed by the cardiologists., Competing Interests: The author declares no conflict of interest., (Copyright: © 2022 The Author(s). Published by IMR Press.)

This review has summarized the methods currently available for cardiac sympathetic assessment in clinical or under research, with emphasis on the principles behind these methodologies. Heart rate variability (HRV) and other methods based on heart rate pattern analysis can reflect the dominance of sympathetic nerve to sinoatrial node function and indirectly show the average activity level of cardiac sympathetic nerve in a period of time. Sympathetic neurotransmitters play a key role of signal transduction after sympathetic nerve discharges. Plasma or local sympathetic neurotransmitter detection can mediately display sympathetic nerve activity. Given cardiac sympathetic nerve innervation, i.e., the distribution of stellate ganglion and its nerve fibers, stellate ganglion activity can be recorded either directly or subcutaneously, or through the surface of the skin using a neurophysiological approach. Stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (SCNA), and skin sympathetic nerve activity (SKNA) can reflect immediate stellate ganglion discharge activity, i.e., cardiac sympathetic nerve activity. These cardiac sympathetic activity assessment methods are all based on the anatomy and physiology of the heart, especially the sympathetic innervation and the sympathetic regulation of the heart. Technological advances, discipline overlapping, and more understanding of the sympathetic innervation and sympathetic regulation of the heart will promote the development of cardiac sympathetic activity assessment methods., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Li and Zheng.)

Background: Cardioneuroablation is an emerging therapy for refractory vasovagal syncope (VVS), but the standard enrollment criterion is undetermined. Mainstream studies empirically enroll patients with cardioinhibitory and mixed types of VVS on the basis of the head-up tilt (HUT). However, a variety of studies have shown that the results of HUT exhibit unpleasant reproducibility., Objective: We aimed to investigate the prognostic value of baseline deceleration capacity in patients with refractory VVS after cardioneuroablation., Methods: This study enrolled 123 patients (mean age 42.2±17.7 years; 54 males [43.9%]) with the diagnosis of VVS, of whom 16 patients had a negative result of HUT (13.0%), 8 (6.5%) had vasodepressive VVS, 32 (26.0%) cardioinhibitory VVS, and 67 (54.5%) mixed VVS. All patients underwent cardioneuroablation that was performed in the left atrium., Results: After a mean follow-up of 4.0±1.1 years, 33 patients experienced syncope/presyncope events (26.8%). Patients with recurrent syncope/presyncope have a lower baseline deceleration capacity level than do those without (8.9±3.2 ms vs 11.3±3.7 ms; P < .001). Each 1-ms increase in deceleration capacity had a 34% (95% confidence interval [CI] 12%-50%) reduced risk of syncope/presyncope recurrence after cardioneuroablation. Nighttime deceleration capacity had the highest discrimination value (area under the curve 0.757; 95% confidence interval 0.657-0.858). At a high-risk threshold of 51% (nighttime deceleration capacity at a cutoff of 9.9 ms), the nighttime deceleration capacity enrollment strategy additionally benefited 18 per 100 patients after cardioneuroablation without syncope/presyncope recurrence as compared with the HUT strategy in decision curve analyses., Conclusion: Baseline nighttime deceleration capacity ≥ 10 ms may act as an indication for cardioneuroablation in patients with refractory VVS., (Copyright © 2022. Published by Elsevier Inc.)

Even after a long time of polymer flooding, over half of the crude oil is still trapped in the reservoir due to the poor plugging capacity. It has been demonstrated that fuzzy-ball fluid can be utilized as an effective plugging fluid. The idea of further increasing oil recovery by fuzzy-ball fluid following polymer flooding drew us to investigate it due to its high performance and effect. In this paper, seepage behavior experiments and parallel core displacement experiments were carried out to evaluate the plugging ability and oil displacement effect of fuzzy-ball fluid. Also, the microscopic blocking mechanism of fuzzy-ball fluid was observed. The results showed that fuzzy-ball fluid has a good plugging capability thanks to the pressure consumption and accumulation plugging mechanisms. The resistance coefficient and residual resistance coefficient of fuzzy-ball fluid are also substantially greater than those of the polymer, at 76.25-239.96 and 13.95-49.91, respectively. Due to its outstanding plugging capability, fuzzy-ball fluid can achieve complete fluid diversion, with the flow fraction of the high-permeability core reduced to nearly 0% and that of the low-permeability core increased to nearly 100%. As a result, low-permeability core oil recovery and total oil recovery both can be enhanced by 46.12-49.24 and 22.81-24.40%, respectively. A field test of fuzzy-ball fluid flooding was carried out in wells TX 1 and TX 2 which have been flooding with polymers. After the fuzzy-ball fluid was introduced, total daily oil production increased by 64.15%. Fuzzy-ball fluid can significantly boost oil recovery after polymer flooding, according to laboratory and field trials, providing a technical solution for heterogeneous sandstone reservoirs to further enhance oil recovery., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Background: The efficacy of catheter-based or thoracoscopic ablation for treating long-standing persistent atrial fibrillation (AF) with a dilated atrium remains suboptimal. This study aimed to assess the feasibility and initial results of simultaneous hybrid ablation with a new biatrial lesion set in these patients., Methods: Twenty-seven consecutive patients with long-standing persistent AF and dilated atrium underwent simultaneous hybrid ablation with a new biatrial lesion set consistent with the principle of the Cox maze procedure at our institution. Patients were followed up at 3, 6, and 12 months after the procedure and annually thereafter., Results: After thoracoscopic epicardial ablation, endocardial mapping confirmed complete bilateral pulmonary vein isolation in 25 patients (96.2%). All patients were followed for a mean of 18.7 ± 8.9 months. Freedom from atrial tachyarrhythmia at 1 year after the single hybrid procedure was 64% with antiarrhythmic drugs and 60% without antiarrhythmic drugs. Freedom from atrial tachyarrhythmia at latest follow-up after the hybrid procedure and redo catheter ablation was 77.8% with antiarrhythmic drugs and 74.1% without antiarrhythmic drugs. In patients with sinus rhythm restoration, mean left atrial diameter decreased from 54.4 ± 4.3 mm to 45.2 ± 4.1 mm ( P  < .001), and mean right atrial diameter decreased from 59.4 ± 3.9 mm to 54.9 ± 4.4 mm ( P  < .001). Postoperative pleural effusion was observed in 3 patients (11.1%), and no adverse events occurred during follow-up., Conclusions: In patients with long-standing persistent AF and a dilated atrium, simultaneous hybrid ablation with the new biatrial lesion set, in combination with touch-up catheter ablation when necessary, can achieve promising results. More studies are needed to confirm these findings., (© 2020 The Authors.)

Aims: The study aims to describe the long-term outcome of radiofrequency catheter ablation for ventricular tachycardia (VT) in a large cohort arrhythmogenic right ventricular cardiomyopathy (ARVC) patients., Methods and Results: Radiofrequency catheter ablation was performed in 284 ARVC patients due to VT between July 2000 and January 2019. An endocardial approach was used initially, with epicardial ablation procedures reserved for those patients who failed an endocardial ablation. Activation, entrainment, pace and substrate mapping strategies were used with regional ablation applied. A total of 393 ablation procedures were performed including endocardial approach only (n = 377) and endo and epicardial combined (n = 16). Right ventricular basal free wall was accounted as the primary substrate of VT in 258 (65.6%) patients. There were 81 patients underwent redo ablation procedure (second time = 81; ≥3 times = 28). New targets were observed in 68.8% of redo procedures. There were 171 VT recurrences and 19 deaths occurred during the follow-up. Ventricular tachycardia-free survival rate of the first, second, and last ablation procedure was 56.7%, 73.2%, and 78.1%, respectively. Multivariate analysis showed ≥3 induced VTs in the procedure was correlated with rehospitalized VT recurrence [hazard ratio (HR) 1.467, 95% confidence interval (CI) 1.052-2.046; P = 0.024]. For all-cause mortality, rehospitalized VT and ≥3 induced VTs were the independent risk factors (HR 2.954, 95% CI 1.8068.038; P = 0.034; HR 3.189, 95% CI 1.073-9.482; P = 0.037)., Conclusion: Endocardial ablation is effective to ARVC VT though it may require repeated procedures. Induced multiple VTs was correlated with worse outcomes., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Less is known about pregnancy in women with arrhythmogenic right ventricular cardiomyopathy (ARVC). From April 1995 to May 2018, 157 women with ARVC were retrospectively enrolled. Data on pregnancy and cardiac outcomes were analyzed. There were 224 pregnancies in 120 patients including 30 (13.4%) spontaneous and 2 (0.9%) medical abortions, 12 cardiac adverse events were recorded including new onset frequent premature ventricular contractions (PVC) in 3 (2.5%) patients, previous PVC numbers increased more than 100% in 5 (4.2%), syncope in 2 (1.7%), sustained ventricular tachycardia and heart failure required hospitalization each in one patient (0.8%). Women with cardiac events showed lower left ventricular ejection fraction (LVEF) (50.3 ± 2.7 vs 60.0 ± 7.3; p = 0.004). No significant change in cardiac structure and function was found at 1 year follow-up postpartum. At a median follow-up of 8 (1 to 32) years, 36 (22.9%) women died. Earlier symptom onset age (hazard ratio 1.046; 95% confidence interval 1.017 to 1.075; p = 0.002) and decreased LVEF (hazard ratio 1.127; 95% confidence interval 1.001 to 1.154; p = 0.041) increased the risk of all-cause mortality, pregnancy had no negative influence on survival. In all the 192 offsprings (mean age 26.3 ± 13.5 years), 2 died of sudden death, no definite ARVC was found. Pregnancy seemed to be acceptable in ARVC, decreased LVEF increased the risk of pregnancy and was associated with poorer long-term survival., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Catheter ablation of ganglionated plexus (GP) as cardioneuroablation in the left atrium (LA) has been used to treat vasovagal syncope (VVS)., Objective: The purpose of this study was to assess the effects of ablation of GPs on heart rate and to observe the acute, short-term, and long-term effects after cardioneuroablation., Methods: A total of 115 consecutive patients with VVS who underwent cardioneuroablation were enrolled. GPs of the LA were identified by high-frequency stimulation and/or anatomic landmarks being targeted by radiofrequency catheter ablation., Results: During ablation of right anterior ganglionated plexus (RAGP), heart rate increased from 61.3 ± 12.2 bpm to 82.4 ± 14.7 bpm (P <.001), whereas during ablation of other GPs only vagal responses were observed. During follow-up of 21.4 ± 13.1 months (median 18 months), 106 participants (92.2%) had no recurrence of syncope or presyncope. Holter data showed that minimal heart rate significantly increased at all follow-up time points (all P<.05), and mean heart rate remained higher than baseline 12 months after ablation (P = .001)., Conclusion: Cardioneuroablation via GP ablation in the LA effectively inhibited the recurrence of VVS. Ablation of RAGP could increase heart rate immediately and for the long term. This unique phenomenon may provide a new potential approach for treatment of neural reflex syncope or bradyarrhythmias., (Copyright © 2019. Published by Elsevier Inc.)

Less is known about bradyarrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC). This cross-sectional study aimed to assess the prevalence and clinical significance of bradyarrhythmias in ARVC. From May 1995 to December 2017, bradyarrhythmias including sick sinus syndrome, atrioventricular block, and intraventricular conductional block (ICB) were investigated in 522 ARVC patients. A total of 169 patients (32.4%) presented with bradyarrhythmias including sick sinus syndrome in18 (3.5%), atrioventricular block in 56 (10.7%), and ICB in 118 patients (22.6%). Multivariate analysis showed right atrial dilation increased the risk of bradyarrhythmias (odds ratio [OR] 1.641, 95% confidence interval [CI] 1.081 to 2.492, p= 0.020). Bradyarrhythmias were not associated with death and heart transplantation. In patients with bradyarrhythmias, female gender, left atrial diameter >40 mm, and New York Heart Association Ⅲ/Ⅳ increased the risk of death and heart transplantation (hazards ratio [HR] = 2.790, 95% CI 1.220 to 6.377, p = 0.015; HR = 4.913, 95% CI 2.058 to 11.730, p <0.001; HR = 3.223, 95% CI 1.246 to 8.340, p = 0.016). Among the 23 patients who underwent device implantation, left atrial diameter >40mm was associated with death and heart transplantation (HR = 9.523, 95% CI 1.587 to 57.126, p = 0.014). In conclusion, bradyarrhythmias were commonly seen in ARVC, and ICB was the most common type. Female, left atrial diameter >40 mm, and NYHA class were associated with death and heart transplantation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Left atrial appendage (LAA) morphology is considered to be associated with ischemic stroke, non-Chicken Wing LAA morphology increases the risk of thromboembolic events. However, existing classification of LAA morphology remains not well quantifiable and therefore may leave room for substantial subjective interpretation. This study aimed to assess interobserver and intraobserver agreements in LAA morphology and its real value in stroke prediction. A total of 2,264 atrial fibrillation patients who underwent computed tomography to explore the LAA anatomy were enrolled. All computed tomography images were given to 3 reviewers to judge the LAA morphology independently. A consensus between all 3 reviewers was only reached in 655 cases (28.9%). In which, 86 patients had previous stroke. Poor intraobserver consistency was observed between 2 times of reading in all the 3 reviewers (Kappa = 0.368, p = 0.014; Kappa = 0.350, p = 0.014; Kappa = 0.333, p = 0.015). Multivariate analysis showed that persistent atrial fibrillation (odds ratio [OR] 1.679; 95% confidence interval [CI] 1.031 to 2.736; p = 0.037), female gender (OR 1.761; 95% CI 1.037 to 2.994; p = 0.036) and age (OR 1.029; 95% CI 1.004 to 1.056; p = 0.025) were associated with previous stroke. LAA morphology was not associated with previous stroke and non-Chicken Wing LAA morphology did not increase the risk of stroke (OR 1.392; 95% CI 0.847 to 2.288; p = 0.192). In conclusion, high interobserver and intraobserver variabilities suggested that existing classification of LAA morphology was unreliable, the interpretation of the relation between LAA morphology and stroke needs caution., (Copyright © 2019. Published by Elsevier Inc.)

Cardiac resynchronization therapy (CRT) is an effective treatment for selected patients with systolic heart failure. Unlike conventional biventricular pacing (BIP), the left ventricular multipoint pacing (MPP) can increase the number of left ventricular pacing sites via a quadripolar lead positioned in the coronary sinus. This synthetic study was conducted to integratively and quantitatively evaluate the clinical outcome of MPP in comparison with BIP. We systematically searched the databases of EMBASE, Ovid medline, and Cochrane Library through May 2018 for studies comparing the clinical outcome of MPP with BIP in the patients who accepted CRT. Hospitalization for reason of heart failure, left ventricular eject fraction (LVEF), CRT response, all-cause morbidity, and cardiovascular death rate was collected for meta-analysis. A total of 11 studies with 29,606 participants were included in this meta-analysis. Compared with BIP group, MPP decreased heart failure hospitalization (OR, 0.41; 95% CI, 0.33 to 0.50; P < 0.00001), improved LVEF (mean difference, 4.97; 95% CI, 3.11 to 6.83; P < 0.00001), increased CRT response (OR, 3.64; 95% CI, 1.68 to 7.87; P = 0.001), and decreased all-cause morbidity (OR, 0.41; 95% CI, 0.26-0.66; P = 0.0002) and cardiovascular death rate (OR, 0.21; 95% CI, 0.11-0.40; P < 0.00001). The published literature demonstrates that MPP was more effective than BIP in the heart failure patients who accepted cardiac resynchronization therapy.

Less is known about atrial remodeling and atrial tachyarrhythmias (ATa) in arrhythmogenic right ventricular cardiomyopathy (ARVC); this cross-sectional study aimed to determine the prevalence, characterization, and predictors of atrial remodeling and ATa in a large series of patients with ARVC. From February 2004 to September 2014, 294 consecutive patients who met the task force criteria for ARVC were enrolled. The prevalence, characterization, and predictors of atrial dilation and ATa were investigated. Right atrium (RA) dilation was identified in 160 patients (54.4%) and left atrium dilation in 66 patients (22.4%). Both RA and left atrium dilation were found in 44 patients (15.0%). Twenty-five patients (8.5%) had atrial fibrillation (AF), whereas 19 patients (6.5%) had atrial flutter (AFL). Of which, 7 patients (2.4%) had both AF and AFL. Multivariate analysis showed that AFL (odds ratio [OR] 10.309; 95% confidence interval [CI] 2.770 to 38.462; p <0.001), hypertension (OR 9.174; 95% CI 2.364 to 35.714; p = 0.001), and RA dilation (OR 6.993; 95% CI 1.623 to 30.303; p = 0.009) were associated with increased risk for AF. AF (OR 10.526; 95% CI 2.786 to 40.000; p = 0.001) increased the risk of AFL. In conclusion, atrial remodeling and ATa were common in patients with ARVC., (Copyright © 2016 Elsevier Inc. All rights reserved.)

A simple, rapid, sensitive and specific method using capillary electrophoresis (CE) coupled with electrostacking and amperometric detection (AD) has been developed for the simultaneous separation and determination of clenbuterol (CLB), terbutaline (TER), salbutamol (SAL) and formoterol (FMT). In this paper, the CE separation and AD conditions were investigated in detail. The optimum conditions were: pH 8.6 Na(2)B(4)O(7)-H(3)BO(3) buffer solution (20.0 mmol/L), 9 kV for the separation voltage, and 1000 mV (versus Ag/AgCl) for the detection potential. When the sample which was dissolved in 70% ACN-water mixture solution was injected 60 s by 15 kV electrokinetic injection, the best stacking effects was obtained. Under the optimum conditions, the enhancement factors of these beta(2)-agonists had been greatly improved more than 5500-fold compared with the conventional electrokinetic injection. And then an excellent linear response was obtained with LODs (S/N = 3) of 0.098, 0.024, 0.063 and 0.920 pmol/L for CLB, TER, SAL and FMT in urine, respectively. The precision was determined in both intra-day (n = 5) and inter-day (n = 15) assays, and the RSDs were not more than 2.1 and 3.4% for migration time and peak current, respectively. The proposed method has been applied to analyze human urine samples successfully.