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Aim: Atrial fibrillation (AF) is a progressive disease from paroxysmal to persistent, and persistent AF (PerAF) had worse prognosis. AF has potential link with inflammation, but it is not clear whether PerAF or paroxysmal AF (ParAF) is more closely related to inflammation. On the basis of inhibiting myocardial physiological uptake, 18 F-fluorodeoxyglucosepositron emission tomography/computed tomography ( 18 F-FDG PET/CT) is an established imaging modality to detect cardiac inflammation. We aimed to decipher the association between AF and atrial inflammatory activity by 18 F-FDG PET/CT., Methods: Thirty-five PerAF patients were compared to age and sex matched ParAF group with baseline 18 F-FDG PET/CT scans prior to radiofrequency catheter ablation (RFCA) in the prospective case-control study. High-fat and low-carbohydrate diet and prolonged fast (HFLC+Fast) was applied to all AF patients before PET/CT. Then 22 AF patients with positive right atrial (RA) wall FDG uptake (HFLC+Fast) were randomly selected and underwent HFLC+Fast+heparin the next day. The CHA2DS2-VASc score was calculated to evaluate the risk of stroke. Clinical data, ECG, echocardiography, and atrial 18 F-FDG uptake were compared., Results: PerAF patients had significantly higher probability of RA wall positive FDG uptake and higher SUVmax than ParAF group [91.4% VS. 28.6%, P < 0.001; SUVmax: 4.10(3.20-4.90) VS. 2.60(2.40-3.10), P < 0.001]. Multivariate logistic regression analyses demonstrated that RA wall SUV max was the independent influencing factor of PerAF (OR = 1.80, 95%CI 1.02-3.18, P = 0.04). In 22 AF patients with RA wall positive FDG uptake (HFLC+Fast), the "HFLC+Fast+Heparin" method did not significantly change RA wall FDG uptake evaluated by either quantitative analysis or visual analysis. High CHA2DS2-VASc score group had higher RA wall 18 F-FDG uptake [3.35 (2.70, 4.50) vs, 2.8 (2.4, 3.1) P = 0.01]., Conclusions: RA wall FDG positive uptake was present mainly in PerAF. A higher RA wall 18 F-FDG uptake was an independent influencing factor of PerAF. RA wall FDG uptake based on 18 F-FDG PET/CT may indicate pathological inflammation., Trial Registration: http://www.chictr.org.cn , ChiCTR2000038288., (© 2023. The Author(s).)

Objective: To explore the association between inflammation activity of left atrial epicardial adipose tissue (LA-EAT) measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) and atrial fibrillation (AF). Methods: A total of 78 patients with AF, who underwent 18 F-FDG PET/CT in the Nuclear Medicine Department of the Third Affiliated Hospital of Soochow University due to abnormally elevated levels of tumor indicators or malignant tumors from March 2018 to December 2019, were enrolled in this retrospective study. According to the examination date of PET/CT and basic characteristics of AF patients (gender, age), a 1∶1 propensity score matching was used to enroll a non-AF control group (78 patients). The maximum standard uptake value of left atrial epicardial tissue (LA-EAT FDG SUV max ) and total EAT volume (V-EAT) were measured by 18 F-FDG PET/CT. Left ventricular ejection fraction (LVEF) and left atrial diameter (LAD) were obtained by echocardiography. Blood lipids and biomarkers of inflammation were measured. The differences of clinical data and EAT-related indicators were compared between the AF group and control group. Logistic multivariate regression analysis was used to determine the related factors of AF. Then the receiver operating characteristic (ROC) curve was used to determine the cutoff value of LA-EAT FDG SUV max on the diagnosis of AF. Univariate and multivariate logistic regression analysis were used to analyze the relationship between the increase of LA-EAT FDG SUV max and AF. Results: The age was (66.9±10.2) years and there were 55 males (70.5%) in the AF group. The age was (66.9±8.0) years, and there were 52 males (66.7%) in the control group (both P >0.05). The LAD ((44.2±5.8) mm vs. (35.4±4.4) mm), V-EAT ((122.1±42.0) cm 3 vs. (91.6±34.5) cm 3 ), and LA-EAT FDG SUV max ((1.6±0.3) vs. (1.4±0.2)) values were significantly higher, while LVEF ((60.1±4.7)% vs. (63.9±2.9)%) was lower in the AF group than in the control group ( P all<0.001). Multivariate logistic regression analysis showed that LAD ( OR =1.340, 95% CI 1.195-1.502), V-EAT ( OR =1.016, 95% CI 1.001-1.031), and LA-EAT FDG SUV max ( OR =1.375, 95% CI 1.095-1.723) were positively correlated with AF, LVEF ( OR =0.781, 95% CI 0.659-0.926) was negatively correlated with AF( P all<0.05). The area under the ROC curve of LA-EAT FDG SUV max for diagnosis of AF was 0.680 (95% CI 0.597-0.764, P <0.001), and the best cut-off value was 1.415 with a sensitivity of 65.4% and specificity of 61.5%. After adjusting for high-density lipoprotein cholesterol, LVEF, LAD and V-EAT, LA-EAT FDG SUV max ≥1.415 was independently associated with AF ( OR =2.982, 95% CI 1.122-7.926, P =0.010). Conclusions: The inflammatory activity of LA-EAT measured by 18 F-FDG PET/CT is an independent risk factor of AF, and the increased inflammatory activity of LA-EAT is positively correlated with AF.

A method to measure the superficial velocity of the water phase in gas-water flow using an electromagnetic flowmeter (EMF) and rotating electric field conductance sensors (REFCSs) is introduced in this paper. An electromagnetic flowmeter instrument factor model is built and the correlation between electromagnetic flowmeter output and gas holdup in different flow patterns are explored through vertical upward gas-water flow dynamic experiments in a pipe with an inner diameter (ID) of 20 mm. Water superficial velocity is predicted based on pattern identification among bubble, churn, and slug flows. The experimental results show that water superficial velocity can be predicted fairly accurately for bubble, churn, and slug flows with a water cut higher than 60% (absolute average percentage deviation and absolute average deviation are 4.1057% and 0.0281 m/s, respectively). The output of the electromagnetic flowmeter is unstable and invalid in slug flows with a water cut below 60% due to the non-conducting gas slug is almost filling the pipe. Therefore, the electromagnetic flowmeter is not preferred to be used in such conditions., Competing Interests: The authors declare no conflict of interest.

High water cut and low velocity vertical upward oil-water two-phase flow is a typical complex system with the features of multiscale, unstable and non-homogenous. We first measure local flow information by using distributed conductance sensor and then develop a multivariate multiscale complex network (MMCN) to reveal the dispersed oil-in-water local flow behavior. Specifically, we infer complex networks at different scales from multi-channel measurements for three typical vertical oil-in-water flow patterns. Then we characterize the generated multiscale complex networks in terms of network clustering measure. The results suggest that the clustering coefficient entropy from the MMCN not only allows indicating the oil-in-water flow pattern transition but also enables to probe the dynamical flow behavior governing the transitions of vertical oil-water two-phase flow.

In the title compound, [Co(C(6)H(6)N(4))(2)(H(2)O)(2)](C(16)H(8)O(8)), the Co(II) cation and the organic anion occupy different crystallographic inversion centres and, as a consequence, the asymmetric unit comprises two half-mol-ecules. The benzene groups are coplanar. The four coordinating N atoms of the two bidentate biimidazole ligands define the equatorial plane of a slightly distorted octa-hedral CoO(2)N(4) geometry, and the water O atoms lie in the axial coordination sites. Translational (a,) and inversion-related symmetry operations link the Co complex mol-ecules and the negatively charged carboxyl-ate anions via inter-molecular N-H⋯O and O-H⋯O hydrogen bonds into sheets parallel to (01). The coordinated water mol-ecules connect the sheets through O-H⋯O hydrogen bonds, forming a three-dimensional framework. In addition, two intra-molecular O-H⋯O hydrogen bonds are observed between the carboxyl and carboxyl-ate groups.