Applicability of the generalized wind profile model over mountainous forests.

The analytical equation based on Monin-Obukhov (M-O) similarity theory (i.e., wind profile equation) has been adopted since 1970s for using in the prediction of wind vertical profile over flat terrains, which is mature and accurate. However, its applicability over complex terrains remains unknown. This applicability signifies the accuracy of the estimations of aerodynamic parameters for the boundary layer of non-flat terrain, such as zero-displacement height (d) and aerodynamic roughness length (z0), which will determine the accuracy of frequency correction and source area analysis in calculating carbon, water, and trace gas fluxes based on vorticity covariance method. Therefore, the validation of wind profile model in non-flat terrain is the first step to test whether the flux model needs improvement. We measured three-dimensional wind speed data by using the Ker Towers (three towers in a watershed) at Qingyuan Forest CERN in the Mountainous Region of east Liaoning Province, and compared them with data from Panjin Agricultural Station in the Liaohe Plain, to evaluate the applicability of a generalized wind profile model based on the Monin-Obukhov similarity theory on non-flat terrain. The results showed that the generalized wind profile model could not predict wind speeds accurately of three flux towers separately located in different sites, indicating that wind profile model was not suitable for predicting wind speeds in complex terrains. In the leaf-off and leaf-on periods, the coefficient of determination (R2) between observed and predicted wind speeds ranged from 0.12 to 0.30. Compared to measured values, the standard error of the predicted wind speeds was high up to 2 m·s-1. The predicted wind speeds were high as twice as field-measured wind speed, indicating substantial overestimation. Nevertheless, this model correctly predicted wind speeds in flat agricultural landscape in Panjin Agricultural Station. The R2 between observed wind speeds and predicted wind speed ranged from 0.90 to 0.93. The standard error between observed and predicted values was only 0.5 m·s-1. Results of the F-test showed that the root-mean-square error of the observed and predicted wind speeds in each secondary forest complex terrain was much greater than that in flat agricultural landscape. Terrain was the primary factor affecting the applicability of wind profile model, followed by seasonality (leaf or leafless canopy). The wind profile model was not applicable to the boundary-layer flows over forest canopies in complex terrains, because the d was underestimated or both the d and z0 were underestimated, resulting in inaccurate estimation of aerodynamic height.

SGLT2 inhibitors for the prevention of atrial fibrillation: a systemic review and meta-analysis.

AIMS: Sodium-glucose co-transporter-2 (SGLT2) inhibitors are reported to have cardiac benefits. The effects of SGLT2 inhibitors on the prevention of atrial fibrillation (AF) remain inconclusive. We aimed to investigate whether SGLT2 inhibitors can prevent AF occurrence in patients with cardiometabolic diseases. METHODS: We searched MEDLINE, EMBASE, and the Cochrane CENTRAL database up to July 1, 2023. Randomized, placebo-controlled trials of SGLT2 inhibitors in patients with diabetes, heart failure, chronic kidney diseases, or cardiometabolic risk factors were included. The primary outcome was AF occurrence. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated in the overall population and selected subgroups. RESULTS: Forty-six trials comprising 101 100 patients were included. Overall, no significant risk reduction of AF occurrence was observed with SGLT2 inhibitors, although there was a favorable trend (RR 0.90, 95% CI 0.80-1.01). In trials with follow-up durations of over one year, a similar result was achieved (RR 0.90, 95% CI 0.80-1.01). The results were consistent across different SGLT2 inhibitors, with RRs (95%CIs) of 0.82 (0.60-1.12) for canagliflozin, 0.87 (0.73-1.03) for dapagliflozin, 0.97 (0.78-1.22) for empagliflozin, 0.99 (0.66-1.50) for sotagliflozin, and 0.87 (0.58-1.29) for ertugliflozin. Analyses in different doses of SGLT2 inhibitors yielded similar results. The associations between SGLT2 inhibitors and AF occurrence were also absent in patients with diabetes, heart failure, and chronic kidney diseases. CONCLUSION: For patients with cardiometabolic diseases or risk factors, SGLT2 inhibitors did not decrease the risk of AF occurrence, regardless of follow-up duration, type or dose of the drug, or the patient population.

The effects of SGLT2 inhibitors on the prevention of atrial fibrillation (AF) remain inconclusive. For patients with cardiometabolic diseases or risk factors, SGLT2 inhibitors did not decrease the risk of AF occurrence, regardless of follow-up duration, type or dose of the drug, or the patient population. Further research is warranted to investigate the potential benefit of SGLT2 inhibitors in AF.

Angiographic assessment of vein of Marshall in atrial fibrillation: Implications for identification and cannulation.

Background: The vein of Marshall (VOM) ethanol infusion improves rhythm control in atrial fibrillation (AF). The identification and cannulation of the VOM can be technically challenging. This study aimed to assess the angiographic morphology of the VOM and investigate its value in the VOM ethanol infusion. Methods: Patients with AF (n = 162) scheduled for combined catheter ablation and VOM ethanol infusion were enrolled. The VOM morphologic features in the right anterior oblique (RAO), the left anterior oblique (LAO), and the LAO cranial views were analyzed. The impact of morphology on the identification and cannulation of the VOM was investigated. Results: The VOM was identified in 159 (98.1 %) and cannulated in 150 (92.6 %) patients. The VOM identification rate in the RAO and LAO/LAO cranial view was 97.3 % and 89.3 %, respectively. Of 134 patients with VOM identification in the LAO/LAO cranial view, 104 (77.6 %) had a VOM ostium clock location (VOMoClock) of ≤3 and 3-4 o'clock. The VOM cannulation success rate in the ≤3, 3-4, 4-5, and 5-6 o'clock groups was 100 %, 92.6 %, 88.5 %, and 77.8 %, respectively (p = 0.032). The median (interquartile range) cannulation time in the four groups was 10.5 (6.3), 12.0 (9.0), 13.0 (23.0), and 34.0 (30.0) minutes, respectively (p < 0.001). The diameter of the coronary sinus ostium in the RAO view and the VOMoClock were independent predictors for difficult cannulation. Conclusions: The VOM morphologic features in different angiographic views provide valuable information which could facilitate the identification and cannulation of the VOM.

Double-wire technique to facilitate vein of Marshall cannulation and ethanol infusion in atrial fibrillation: a case series.

BACKGROUND: The vein of Marshall (VOM) ethanol infusion is increasingly performed in combination with catheter ablation in atrial fibrillation (AF). The cannulation of the VOM can sometimes be challenging. This study aimed to evaluate the double-wire technique in cases of difficult cannulation of the VOM. CASE PRESENTATION: Patients with AF scheduled for combined catheter ablation and VOM ethanol infusion were consecutively enrolled. The procedure was performed via the femoral vein. If the regular cannulation technique with one angioplasty wire failed or took more than 20 min, the double-wire technique using a stabilizing wire and a cannulation wire was performed. The unique technique was used mainly in two scenarios, when the Eustachian ridge was too prominent as a barrier for catheter manipulation or when the VOM ostium was close to the coronary sinus ostium. Of 162 patients scheduled for VOM ethanol infusion, the double-wire technique was applied in 6 (3.7%) patients and led to a 100% successful cannulation rate of the VOM. Of the six patients, two had a prominent Eustachian ridge, and four had a VOM ostium close to the coronary sinus ostium. The mean cannulation time was 33.3 ± 7.3 min. The ethanol infusion was successfully performed in 5 patients. One patient had a collateral circulation in the distal VOM, and ethanol infusion was not performed. CONCLUSIONS: The double-wire technique can facilitate VOM cannulation and ethanol infusion in challenging cases. WORD COUNT: 231.

Occluding morphologically complicated left atrial appendage using the small-umbrella LAmbre device.

BACKGROUND: Percutaneous left atrial appendage (LAA) occlusion is effective for stroke prevention in patients with atrial fibrillation. LAA can have a complex anatomy, such as multiple lobes or a large orifice, which may render it unsuitable for occlusion using regular devices. We aimed to investigate the feasibility, safety, and short-term efficacy of the small-umbrella LAmbre device for morphologically complicated LAA. METHODS: We retrospectively enrolled 129 consecutive patients who underwent LAA occlusion using the LAmbre device; the small-umbrella LAmbre device was used in 30 of these patients. We analyzed patients' characteristics, procedural details, and outcomes. RESULTS: Twenty-two patients (73.3%) had multilobed (≥ 2) LAA. The umbrella of the occluder was anchored in the branch in 9 patients and in the common trunks of branches in 13 patients. The landing zone and orifice diameters were 19.0 ± 4.39 mm and 27.4 ± 3.95 mm, respectively. The sizes of the umbrella and occluder cover were 22.0 ± 3.42 mm and 34.3 ± 2.75 mm, respectively. At 3-month follow-up transesophageal echocardiography in 24 patients, no peri-device residual flow was reported. Device thrombosis was detected in one patient at 3 months and disappeared after 3 months of anticoagulation. Ischemic stroke occurred in one patient; no other adverse events were reported. CONCLUSIONS: Occlusion of morphologically complicated LAA using the small-umbrella LAmbre device was feasible, safe, and effective in patients with atrial fibrillation in this study. This occluder provides an alternative for patients who cannot be treated with regular-sized LAA occlusion devices.

Characteristics and Long-Term Ablation Outcomes of Supraventricular Arrhythmias in Hypertrophic Cardiomyopathy: A 10-Year, Single-Center Experience.

Background: A variety of supraventricular arrhythmias (SVAs) may occur in patients with hypertrophic cardiomyopathy (HCM). The characteristics and long-term ablation outcomes of different types of SVAs in HCM have not been comprehensively investigated. Methods: We retrospectively enrolled 101 consecutive patients with HCM who were referred to the electrophysiology and arrhythmia service from May 2010 to October 2020. The clinical features and ablation outcomes were analyzed. Results: Seventy-eight patients had SVAs, which comprised 50 (64.1%) cases of atrial fibrillation (AF), 16 (20.5%) of atrial flutter (AFL), 15 (19.2%) of atrioventricular reentrant tachycardia (AVRT), 11 (14.1%) of atrial arrhythmia (AT), and 3 (3.8%) of atrioventricular nodal reentrant tachycardia (AVNRT). Thirty-four patients underwent catheter ablation and were followed up for a median (interquartile range) of 58.5 (82.9) months. There was no recurrence in patients with non-AF SVAs. In patients with AF, the 1- and 7-year AF-free survival rates were 87.5 and 49.5%, respectively. A receiver operator characteristic analysis showed that a greater left ventricular end-diastolic dimension (LVEDD) was associated with a higher recurrence of AF, with an optimum cutoff value of 47 mm (c-statistic = 0.91, p = 0.011, sensitivity = 1.00, specificity = 0.82). In Kaplan-Meier analysis, patients with a LVEDD ≥ 47 mm had worse AF-free survival than those with a LVEDD <47 mm (log-rank p = 0.014). Conclusions: In this unique population of HCM, AF was the most common SVA, followed in order by AFL, AVRT, AT, and AVNRT. The long-term catheter ablation outcome for non-AF SVAs in HCM is satisfactory. A greater LVEDD predicts AF recurrence after catheter ablation in patients with HCM.

Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Patients With Pulmonary Hypertension: Feasibility and Long-Term Outcome.

BACKGROUND: Supraventricular tachycardia (SVT) occurs commonly and is strongly correlated with clinical deterioration in patients with pulmonary hypertension (PH). This study aimed to investigate the feasibility and long-term outcome of radiofrequency catheter ablation (RFCA) in PH patients with SVT. MATERIALS AND METHODS: Consecutive PH patients with SVT who were scheduled to undergo electrophysiological study and RFCA between September 2010 and July 2019 were included. The acute results and long-term success of RFCA were assessed after the procedure. RESULTS: In total, 71 PH patients with 76 episodes of SVT were analyzed. Cavotricuspid isthmus-dependent atrial flutter (n = 33, 43.5%) was the most common SVT type, followed by atrioventricular nodal reentrant tachycardia (n = 16, 21.1%). Of the 71 patients, 60 (84.5%) underwent successful electrophysiological study and were subsequently treated by RFCA. Among them, acute sinus rhythm was restored in 54 (90.0%) patients, and procedure-related complications were observed in 4 (6.7%) patients. Univariate logistic regression analysis showed that cavotricuspid isthmus-independent atrial flutter [odds ratio (OR) 25.00, 95% confidence interval (CI) 3.45-180.98, p = 0.001] and wider pulmonary artery diameter (OR 1.19, 95% CI 1.03-1.38; p = 0.016) were associated with RFCA failure. During a median follow-up of 36 (range, 3-108) months, 7 patients with atrial flutter experienced recurrence, yielding a 78.3% 3-year success rate for RFCA treatment. CONCLUSION: The findings suggest that RFCA of SVT in PH patients is feasible and has a good long-term success rate. Cavotricuspid isthmus-independent atrial flutter and a wider PAD could increase the risk for ablation failure.

Knockdown of long non-coding RNA TUG1 depresses apoptosis of hippocampal neurons in Alzheimer's disease by elevating microRNA-15a and repressing ROCK1 expression.

OBJECTIVE: Many studies have already suggested the role of long non-coding RNAs (lncRNAs) in Alzheimer's disease (AD), but the functions of lncRNA Taurine Upregulated Gene 1 (TUG1) in AD have been scarcely discussed. This study aims to verify how TUG1 affects hippocampal neurons in AD through modulation of microRNA-15a (miR-15a)/Rho-associated protein kinase 1 (ROCK1). METHOD: AD mice was modeled through injection of ß-amyloid 25-35 (Aß25-35) into the lateral ventricle. After modeling, the mice were injected with altered TUG1 and/or miR-15a agomir lentiviruses. The spatial learning ability and memory ability of mice were detected through Morris water maze test. Hippocampal neuronal apoptosis and oxidative stress indicators in AD mice were then detected. The hippocampal neuron AD model was induced by Aß25-35. Next, the neurons were, respectively, transfected with altered TUG1 vector and/or miR-15a mimics to determine the proliferation inhibition and apoptosis of hippocampal neurons. The interactions between TUG1 and miR-15a, and between miR-15a and ROCK1 were assessed using bioinformatic prediction, dual luciferase reporter gene assay and RNA-pull-down assay. RESULTS: In the animal models, Aß25-35-induced mice exhibited decreased spatial learning and memory ability, obvious pathological injury, promoted hippocampal neuronal apoptosis and decreased antioxidant ability. TUG1 silencing and miR-15a elevation improved spatial learning ability and memory ability, ameliorated pathological injury, depressed neuronal apoptosis, and strengthened antioxidant ability of hippocampal neurons in AD mice. In cellular models, Aß25-35-treated hippocampal neurons presented inhibited neuronal viability and promoted neuronal apoptosis. TUG1 silencing and miR-15a elevation increased viability and limited apoptosis of Aß25-35-treated hippocampal neurons. TUG1 specifically bound to miR-15a, and miR-15a targeted ROCK1. CONCLUSION: Collectively, this study reveals that TUG1 knockdown restricts apoptosis of hippocampal neurons in AD by elevating miR-15a and suppressing ROCK1 expression, and provides a new therapeutic target for AD treatment.

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The relationship between the structure and function of forest ecosystems is the main intere-sts in the research area of forest ecology and management. However, over complex terrains in particular, these studies had been challenged as uneasy tasks due to the limitations in the forest survey and measurement techniques and other supporting technologies. Chinese Academy of Sciences (CAS) funded "Multi-Tower LiDAR/ECFlux Platform for Monitoring the Structure and Function of Secondary Forest Ecosystems" (Multi-Tower Platform, MTP) as a field station network corner-stone research infrastructure project, which was completed by Qingyuan Forest CERN (Chinese Ecosystem Research Network). In a distinctively-bounded and monitored-outlet watershed, the MTP was integrated by light detection and ranging (LiDAR) scanners, eddy covariance (EC) flux instrument systems, whole- and sub-watershed hydrology station network, long-term forest plot arrays, and live data center. Using LiDAR scanning, the MTP can get cloud data for holographic information on canopy structure. The EC-flux instrument system and hydrology station network along with forest plot arrays could ensure the reliability of water and carbon observations over this complex terrain, which allows to verify the studies on flux measurement technologies and methods, as well as to understand the processes of ecohydrology and CO2 exchange between forest ecosystem and the atmosphere. Further, we can also assess the primary ecosystem services, including water conservation and carbon sequestration. All the data from "tower-station" were streamed through wireless network, which would facilitate data monitoring, management, and sharing. There are three tasks of MTP team: 1) defining innovative methods and descriptors to quantify three-dimensional forest structure; 2) developing theories and techniques to measure CO2/H2O fluxes and other trace gases over complex terrains; 3) understanding the relationship between structure and function of forest ecosystems, providing information and rationales for forest management practices to assure broad and sustainable benefits from forests.