Efficacy and safety of pulsed field ablation for accessory pathways: a pilot study.

AIMS: Radiofrequency ablation is used as a first-line therapy for accessory pathways (APs). However, data regarding the effects of pulsed field ablation (PFA) on APs are limited. We sought to evaluate the acute procedural and 6-month success and safety of PFA in a cohort of patients with APs. METHODS AND RESULTS: A focal contact force-sensing PFA catheter was used for patients with APs. Pulsed field ablation generator generated a bipolar and biphasic waveform (±1000 V) with a duration of 100 ms from the tip of the PFA catheter. A 100% acute procedural success was achieved in 10 conscious patients with APs (7 left anterolateral, 2 left inferolateral, and 1 right posteroseptal APs) including 6 (60%) patients after an initial application. The average total ablation time was 6.3 ± 4.9 s for 4.7 ± 1.8 ablation sites (ASs), including 3.1 ± 2.4 s at targets and 3.2 ± 2.9 s at 3.2 ± 2 bolus ASs. The mean skin-to-skin time was 59.3 ± 15.5 min, and PFA catheter dwell time was 29.4 ± 7.8 min. One patient encountered transient sinus arrest during PFA due to parasympathetic overexcitation. Sinus rhythm was restored in all patients without any significant adverse events during the short-term follow-up. CONCLUSION: Pulsed field ablation of APs was feasible, effective, and safe. Its efficiency was remarkable for its ultrarapid termination of AP conduction. Further studies are warranted to prove whether utilization of PFA with current parameters can extend to manifold AP ablation.

Impact of left atrial appendage orifice diameter on the safety and efficacy of left atrial appendage closure using the LAmbre device.

BACKGROUND: The diameter and shape of the left atrial appendage (LAA) orifices may influence occluder selection and the outcomes of left atrial appendage closure (LAAC) procedure. This study aimed to evaluate the impact of LAA orifice diameter on the safety and efficacy of LAAC using the LAmbre device. METHODS: A total of 133 patients with nonvalvular atrial fibrillation (AF) who underwent LAAC with the LAmbre device between June 2018 and June 2020 were included in this study. The patients were categorized into two groups based on the maximal diameter of the LAA orifice: the large LAA group (n = 45) with a maximal orifice diameter of ≥31 mm, and the normal LAA group (n = 88) with a maximal orifice diameter of <31 mm. The study assessed periprocedural characteristics and long-term clinical follow-up. RESULTS: Successful implantation of the LAmbre device was observed in all patients. The incidence of periprocedural peridevice leakage (PDL) was significantly higher in the large LAA group (P < 0.001), while the incidence of acute pericardial effusion (PE) during the procedure was comparable between the two groups (P = 1.000). After a mean follow-up period of 4.8 ± 1.7 years, three patients in the large LAA group developed delayed PE, while no patients in the normal LAA group did (P = 0.037). Additionally, a larger LAA maximal orifice diameter was associated with a higher prevalence of PDL (P = 0.001) and PE (including both acute and delayed PE) (P = 0.027). The optimal cutoff value of the LAA maximal orifice diameter for predicting PDL and PE after LAAC with the LAmbre device was determined to be 30 mm. CONCLUSION: The findings suggest that the LAmbre device is a safe and feasible option for occluding the LAA, regardless of its orifice diameter. However, it is important to note that a larger LAA orifice diameter may increase the risk of PDL and delayed PE.

Electrode Surface-Modified Strategy for Improving the Voltage of Aqueous Supercapacitors.

Endowing aqueous supercapacitors (SCs) with high voltage is of great practical significance, but it is restricted by the water decomposition reaction occurring in the electrodes. Here, a novel surface treatment strategy is proposed to inhibit the hydrogen evolution reaction/oxygen evolution reaction at the cathode and anode by forming a passivation layer at the whole electrode surface, which widens the electrochemical stability window of the electrode and working voltage of the aqueous SCs. In addition, the cathode overpotential is increased from -1.3 to -1.48 V, and the anode is expanded from 1.42 to 1.59 V. Importantly, the aqueous SCs can work stably at 3 V operating voltage, enabling the coulombic efficiency and capacitance retention of the optimized SCs is 97% and 96% after 5000 cycles, respectively. This strategy of surface modification provides effective guidance to achieve high-voltage aqueous energy storage devices.

Delayed pericardial effusion or tamponade following left atrial appendage closure: A single-center experience.

BACKGROUND: Pericardial effusion or pericardial tamponade (PE/PT) is a relatively common complication of left atrial appendage closure (LAAC). However, delayed PE/PT is rare with limited data. The aim of the study was to analyze the incidence and clinical consequences of delayed PE/PT following LAAC. METHODS: Patients with nonvalvular AF who were successfully implanted with LAAC devices from October 2014 to April 2021 were consecutively screened. Subjects experiencing delayed PE/PT after LAAC were included. All treatment sessions of the subjects were recorded in detail. After discharge, the patients were followed up for clinical outcomes. RESULTS: A total of 748 patients with successful LAAC [nitinol cage device (475 Watchman 2.5), nitinol plug device (131 ACP and 142 LAmbre)] were screened. Six patients experienced delayed PE/PT (1 Watchman, 2 ACP, 3 LAmbre). The incidence of delayed PE/PT was higher in patients with a nitinol plug device (1.8% vs. 0.2%, P = 0.027). Bloody PE only occurred in patients with a nitinol plug device (5/273, 1.8%). All the patients accepted pericardiocentesis and discontinuing antithrombotic medication, and none of the patients died or needed cardiac surgery. All patients were followed up for 810 (598, 1174) days after discharge. None of them developed constrictive pericarditis or thromboembolic or major bleeding events. CONCLUSION: Delayed PE/PT is rare but can occur, and the incidence of delayed bloody PE/PT for the nitinol plug device was higher than that for the nitinol cage device. The strategy of emergency pericardiocentesis combined with discontinuing antithrombotic medication may be effective for delayed bloody PE/PT.

Safety and efficacy of low-dose non-vitamin K antagonist oral anticoagulants versus warfarin after left atrial appendage closure with the Watchman device.

BACKGROUND/PURPOSE: Anticoagulant therapy is suggested within 45 days after Watchman device implantation for stroke prevention in patients with atrial fibrillation (AF). A previous study demonstrated that non-vitamin K antagonist oral anticoagulants (NOACs) were a feasible peri- and postprocedural alternative to warfarin. The present study aimed to compare the safety and efficacy of using different anticoagulants (low-dose NOACs vs. warfarin) within 45 days after Watchman device implantation in a Chinese population. METHODS: Patients with successful Watchman device implantation from October 2014 to June 2020 were included. All patients received anticoagulants within 45 days after the procedure, and those patients were divided into three groups according to the type of postprocedural anticoagulants. Transesophageal echocardiography follow-up was performed 45 days post procedure to assess residual flow and the occurrence of device-related thrombus (DRT). RESULTS: A total of 368 patients were enrolled in the study. The study population was divided into three groups: the warfarin group (n = 77), the dabigatran group (n = 165) and the rivaroxaban group (n = 126). Periprocedural major bleeding was higher in the warfarin group (2.6% vs. 0% vs. 0%, P = 0.043), while minor bleeding was comparable among the groups (3.9% vs. 1.2% vs. 0.8%, P = 0.230). No periprocedural transient ischemic attack/stroke occurred. At follow-up, the incidence of DRT was higher in the warfarin group than in the other groups (4.2% vs. 0.6% vs. 0.8%; P = 0.116), but the difference was not statistically significant. The rates of thromboembolic and bleeding events were similar in the three groups. CONCLUSION: The safety and efficacy of low-dose dabigatran and rivaroxaban were comparable to those of warfarin within 45 days after Watchman device implantation in a Chinese population.

Percutaneous Left Atrial Appendage Closure Confirmed by Intra-Procedural Transesophageal Echocardiography under Local Anesthesia: Safety and Clinical Efficacy.

BACKGROUND: Percutaneous left atrial appendage closure (LAAC) is usually performed under general anesthesia (GA) guided by transesophageal echocardiography (TEE), or under local anesthesia (LA) guided by intracardiac echocardiography (ICE). GA is known to carry some disadvantages. It is sometimes technically challenging to obtain adequate imaging of the left atrial appendage (LAA) with LAAC guided by ICE. This study aimed to assess the safety and clinical efficacy of LAAC guided by TEE under LA in patients with non-valvular atrial fibrillation (AF). METHODS: A total of 159 patients (70.5 ± 8.2 years; 66% male) with AF who had a high risk of stroke and bleeding or who had contraindications for oral anticoagulation underwent LAAC under LA. TEE or computed tomography (CT) follow-up was scheduled approximately 6 weeks after the procedure. Patients were followed to assess ischemic stroke and major bleeding events. RESULTS: The LAA was successfully occluded in 152 patients (95.6%). There were 2 (1.3%) periprocedural major adverse events. A total of 142 patients (93.4%) finished TEE or CT follow-up. Thrombus formation as seen on the device was documented in 2 patients. All of the LAAs were completely sealed with the absence of flow or with minimal flow. The median follow-up period was 522 days, resulting in a total of 216 patient-years. Ischemic stroke occurred in 4 patients. The annual ischemic stroke rate was 1.9/100 person-years. Major bleeding occurred in 2 patients. The annual major bleeding rate was 1.9/100 person-years. CONCLUSIONS: In this study, percutaneous LAAC using TEE under LA was safe and showed encouraging results for stroke prevention and major bleeding reduction.

Endo-epicardial ablation vs endocardial ablation for the management of ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy: A systematic review and meta-analysis.

BACKGROUND: The pathologic process of ARVC (arrhythmogenic right ventricular cardiomyopathy) typically originates in the epicardium or subepicardial layers with progression toward endocardium. However, in the most recent ARVC international task force consensus statement, epicardial ventricular tachycardia (VT) ablation is recommended as a Class I indication only in patients with at least one failed endocardial VT ablation attempt. OBJECTIVE: The aim of this meta-analysis is to assess the outcomes of ARVC patients undergoing combined endo-epicardial VT ablation, as compared to endocardial ablation alone. METHODS: A systematic review of PubMed, Embase, and Cochrane was performed for studies reporting clinical outcomes of endo-epicardial VT ablation vs endocardial-only VT ablation in patients with ARVC. Fixed-Effect model was used if I2 < 25 and the Random-Effects Model was used if I2 ≥ 25%. RESULTS: Nine studies consisting of 452 patients were included (mean age 42.3 ± 5.7 years; 70% male). After a mean follow-up of 48.1 ± 21.5 months, endo-epicardial ablation was associated with 42% relative risk reduction in VA recurrence as opposed to endocardial ablation alone (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.45-0.75; P < .0001). No significant differences were noted between endo-epicardial and endocardial VT ablation groups in terms of all-cause mortality (RR, 1.19; 95% CI, 0.03-47.08; P = .93) and acute procedural complications (RR, 5.39; 95% CI, 0.60-48.74; P = .13). CONCLUSIONS: Our findings suggest that in patients with ARVC, endo-epicardial VT ablation is associated with a significant reduction in VA recurrence as opposed to endocardial ablation alone, without a significant difference in all-cause mortality or acute procedural complications.

Left atrial appendage closure with zero fluoroscopic exposure via intracardiac echocardiographic guidance.

BACKGROUND/PURPOSE: Left atrial appendage closure (LAAC) is conventionally guided by fluoroscopy and transesophageal echocardiography. We introduce an LAAC technique without fluoroscopy exposure using intracardiac echocardiography (ICE) and electroanatomic mapping system (EAMS) under local anesthesia. METHODS: Seven non-valvular atrial fibrillation patients who underwent LAAC with the LAmbre devices under the ICE and EAMS guidance were compared to 7 patients following the conventional approach by propensity score matching. ICE probe was advanced into the left atrium (LA) to guide sizing and device implantation following the orthogonal tri-axial technique (Axis-X: from left pulmonary veins [PVs] to LAA; Axis-Y: from right PV ostium to LAA; Axis-Z: from lower LA to LAA). RESULTS: The mean diameters of ostia and landing zone were 21.4 ± 3.9 mm and 20.4 ± 4.2 mm, respectively. LAmbre devices with a mean umbrella diameter of 23.7 ± 4.2 mm and cover disc diameter of 29.4 ± 3.6 mm were successfully implanted and acute complete LAA sealing without peri-device leak (PDL) were achieved in all cases. Neither fluoroscopy exposure nor contrast consumption was recorded. No procedure related complications were documented. The mean procedural time and PDLs at follow-ups were comparable to those in the conventional group. No stroke or thromboembolic events were documented. CONCLUSION: The fluoroscopy exposure could be minimized, even to zero, in the ICEguided LAAC procedures feasibly and safely using LAmbre devices. The orthogonal triaxial technique is considered efficacious and safe for the procedures.

Combination of left atrial appendage closure and catheter ablation in a single procedure for patients with atrial fibrillation: Multicenter experience.

BACKGROUND/PURPOSE: Experience in procedures combining left atrial appendage (LAA) closure (LAAC) and catheter ablation (CA) was scarce in Chinese nonvalvular atrial fibrillation (AF) patients with high risks for stroke and bleeding. We aimed to investigate the efficacy and safety of the combination therapy with LAAC and AF CA in a single procedure based on the multicenter data and medium-term follow-up results. METHODS: A total of 122 AF patients with a mean CHA2DS2-VASc score of 4.3 ± 1.4 and HAS-BLED score of 3.3 ± 1.0 were enrolled. The Watchman (n = 83) devices were implanted either before or after AF ablations in the same procedure, while the Amplatzer Cardiac Plug (ACP, n = 39) devices were implanted immediately after CA. AF recurrence and transesophageal echocardiography results were evaluated. RESULTS: All devices were successfully implanted and acute complete LAA occlusions were achieved in 115 (94.3%) of patients. Neither acute nor chronic peri-device leaks greater than 5 mm were detected. Oral anticoagulation was held in all patients but two with asymptomatic device-related thrombi, which were resolved after prolonged anticoagulation. AF-free success rate without antiarrhythmic drugs was 76.2% after a mean follow-up of 11.5 ± 6.8 months. No serious complications were observed during the follow-up. CONCLUSION: The combination therapy with LAAC and AF ablation in a single procedure was efficacious and safe in the Chinese symptomatic AF population with high risk for stroke and bleeding.

Adsorption of Tea Polyphenols using Microporous Starch: A Study of Kinetics, Equilibrium and Thermodynamics.

Microporous starch (MPS) granules were formed by the partial hydrolysis of starch using α-amylase and glucoamylase. Due to its biodegradability and safety, MPS was employed to adsorb tea polyphenols (TPS) based on their microporous characteristics. The influences of solution pH, time, initial concentration and temperature on the adsorptive capacity were investigated. The adsorption kinetics data conformed to the pseudo second-order kinetics model, and the equilibrium adsorption data were well described by the Langmuir isotherm model. According to the fitting of the adsorption isotherm formula, the maximum adsorption capacity of TPS onto MPS at pH 6.7 and T = 293 K was approximately 63.1 mg/g. The thermodynamic parameters suggested that the adsorption of TPS onto MPS was spontaneous and exothermic. Fourier transform infrared (FT-IR) analysis and the thermodynamics data were consistent with a physical adsorption mechanism. In addition, MPS-loaded TPS had better stability during long-term storage at ambient temperature.

Association of Left Atrial Appendage Voltage with Ischemic Stroke in Patients with Atrial Fibrillation.

BACKGROUND: Low atrial voltage is associated with an increased risk of stroke. The relationship between left atrial appendage voltage (LAAV) and ischemic stroke remains unknown. Low LAAV may predict the prevalence of ischemic stroke in patients with atrial fibrillation (AF). METHODS: A total of 1108 patients with AF referred for catheter ablation were consecutively included from January 2015 to May 2018. The patients were divided into stroke and control groups based on previous ischemic stroke by neuroimaging criteria. LAAV was measured with a circular mapping catheter in sinus rhythm after ablation. Variables were compared, and logistic regression was performed to assess the relationship between LAAV and stroke. RESULTS: A total of 120 patients (10.8%) had a history of ischemic stroke. The patients in the stroke group were older and had higher percentages of hypertension, diabetes mellitus and coronary/vascular disease. The CHA2DS2-VASc score was higher and left atrial diameter was larger in the patients with stroke. More left atrial appendage thrombi and spontaneous echo contrast were detected in the stroke group. LAAV was significantly lower in the stroke group compared with the controls (5.3 ± 1.8 mV vs. 6.5 ± 1.8 mV; p < 0.001). Multivariate logistic regression revealed that a lower LAAV was associated with increased stroke prevalence [odds ratio = 0.75; 95% confidence interval (CI) 0.65-0.87; p < 0.001]. LAAV had a predictive value, with an area under the curve of 0.83 (95% CI 0.79-0.87; p < 0.001). With an optimal cut-off value of 5.2 mV for LAAV, the sensitivity and specificity were 75% and 74%, respectively. CONCLUSIONS: Lower LAAV in AF patients was associated with increased ischemic stroke prevalence. Whether LAAV is related to incident stroke requires further studies.

Optimal combination strategy of left atrial appendage closure plus catheter ablation in a single procedure in patients with nonvalvular atrial fibrillation.

BACKGROUND: The efficacy and safety of combining left atrial appendage closure (LAAC) plus atrial fibrillation (AF) catheter ablation (CA) in a single procedure has been established, but the optimal combination strategy has not been thoroughly elucidated to date. OBJECTIVE: We aimed to investigate the impact of different combination strategies on clinical outcomes. METHODS: Eighty-two consecutive patients with symptomatic AF (mean CHA2 DS2 -VASc score 4.4 ± 1.4, mean HAS-BLED score 3.5 ± 1.0) were enrolled. LAAC with the Watchman device was performed either before (occlusion-first group, N  =  52) or after (ablation-first group, N  =  30) CA. Procedural and clinical data were retrospectively analyzed to evaluate the advantages of each strategy. RESULTS: Complete device occlusions were achieved in 92.3% and 90.0% of patients, respectively (P  =  0.719). Neither acute nor chronic peridevice leak greater than 5 mm was detected. Oral anticoagulants were held in all patients, except two (one in each group) with asymptomatic device-related thrombi. AF-free success rates were comparable between groups with a mean follow-up of 11.2 ± 7.3 months (75.0% vs. 70.0%, log-rank P  =  0.311). The new peridevice leak rate was significantly lower in the occlusion-first group (7.7% vs. 26.7%, P  =  0.019). Multivariate logistic regression demonstrated that the combination strategy was independently associated with the new peridevice leak (P  =  0.025, OR 13.3). CONCLUSIONS: Both occlusion-first and ablation-first strategies were efficacious and safe as combined procedures in patients with nonvalvular AF; however, the occlusion-first strategy was associated with lower new peridevice leak rates at follow-up.

The effects of entanglement concentration on the hydrodynamic properties of cereal starches.

BACKGROUND: The hydrodynamic properties of four cereal starches in dilute and semi-dilute aqueous solutions were investigated using an Ubbelohde viscometer, a transmission electron microscope and steady shear rheological measurements. RESULTS: The results indicated that the starch solutions showed the nonlinear shape of the ηsp /c versus c curves in dilute solutions, followed by a linear increase to different extents thereafter. The intrinsic viscosity might be positively correlated with the entanglement concentration (ce ). Compared to normal maize and wheat starch solutions, ce influences more significantly the network formation of normal and waxy rice starch solutions. At concentrations ≤ ce , the gelatinized cereal starch solutions hardly exhibit shear thinning behavior, whereas shear thinning behavior developed at concentrations > ce , at which the solutions were pseudoplastic and thixotropic. CONCLUSION: The obtained information will be very useful, based on ce as a reference value, in regulating the starch concentration suitable for different industrial applications. © 2016 Society of Chemical Industry.

Morphology controllable nano-sheet polypyrrole-graphene composites for high-rate supercapacitor.

Polypyrrole is a promising candidate for supercapacitor electrode materials due to its high capacitance and low cost. However, the major bottlenecks restricting its application are its poor rate capability and cycling stability. Herein, we control the morphology of polypyrrole-graphene composites by adjusting the graphene content, causing the typical "cauliflower" morphology of polypyrrole to gradually turn into the homogeneous nano-sheet morphology of these composites. The composites consequently exhibit good thermal stability, high protonation level (37.4%), high electronic conductivity (625.3 S m(-1)), and fast relaxation time (0.22 s). These remarkable characteristics afford a high capacitance of 255.7 F g(-1) at 0.2 A g(-1), still retaining a capacitance of 199.6 F g(-1) at 25.6 A g(-1). In addition, high capacitance retention of up to 93% is observed after 1000 cycles testing at different current densities of 0.2, 1.6, 6.4, 12.8 and 25.6 A g(-1), indicating high stability. The composite's excellent electrochemical performance is mainly attributed to its nano-sheet structure and high electronic conductivity, providing unobstructed pathways for the fast diffusion and exchange of ions/electrons.

Effects of Exogenous Enzymatic Treatment During Processing on the Sensory Quality of Summer Tieguanyin Oolong Tea from the Chinese Anxi County.

In order to attenuate the bitter taste and improve the aroma of the summer tieguanyin oolong tea from the Chinese Anxi county, the effects of processing treatment with exogenous laccase and α-galactosidase on tea sensory quality and related compounds were investigated. The solutions of laccase and/or α-galactosidase were sprayed on the tea leaves before the first drying process. The sensory evaluation results showed that the sensory quality of the tea was significantly enhanced with the enzymatic treatment. The combined application of laccase at 8.25 and α-galactosidase at 22 U per kg of fresh tea shoots achieved the most satisfying sensory quality. Further analysis of flavour-related constituents was carried out by HPLC and GC-MS. The HPLC analysis showed that the contents of catechins and total polyphenols were reduced, compared to the untreated group, by 11.9 and 13.3% respectively, and the total soluble sugars and water extract content were increased by 19.4 and 6.6% respectively, after the treatment with both enzymes. The decrease of catechins and total polyphenols reduced the bitterness and astringency of the summer tea, while the increase of total soluble sugars and water extract content improved the sweetness and mellow taste. The aromatic compound data from GC-MS showed that the total essential oil content in these tea samples co-treated with laccase and α-galactosidase increased significantly, in which aldehydes, alcohols, esters and alkenes increased by 23.28, 37.05, 20.10 and 38.99%, respectively. Our data suggest that the exogenous enzymatic treatment can enhance the summer oolong tea quality, especially its taste and aroma.

Clinical outcomes of combined catheter ablation and left atrial appendage closure in elderly patients with nonvalvular atrial fibrillation.

BACKGROUND: Catheter ablation (CA) combined with left atrial appendage closure (LAAC) has emerged as a promising method to relieve symptoms while reducing the incidence of stroke in selected high-risk patients with atrial fibrillation (AF). HYPOTHESIS: We aimed to investigate the clinical outcomes of combined CA and LAAC in elderly patients. METHODS: A total of 316 patients with symptomatic drug-refractory AF who underwent combined CA and LAAC between January 2016 and December 2020 were retrospectively included. Baseline characteristics, periprocedural complications, and clinical events during follow-up were recorded and compared between patients aged ≥ 75 years (n = 66) and <75 years (n = 250). RESULTS: Pulmonary vein isolation and satisfactory LAAC were achieved in all patients. No patients experienced death or stroke/transient ischemic stroke periprocedurally. After a median follow-up of 12.2 (6.7-24.4) months and 11.9 (5.5-23.6) months, the rate of sinus rhythm maintenance was comparable between the two groups (≥75 years: 78.8% vs. <75 years: 80.8%; log-rank test, p = 0.674). The median follow-up periods for clinical outcomes were 27.9 (9.3-44.8) months and 25.2 (10.8-45.7) months, respectively. In patients aged ≥ 75 years, one suffered ischemic stroke, and one experienced major bleeding event. In patients aged < 75 years, four had ischemic stroke, and eight had major bleeding events. Two patients aged < 75 years died during follow-up, while none of the patients aged ≥ 75 years died. CONCLUSIONS: Combining CA and LAAC was feasible, safe and effective in elderly patients with AF.

The anti-digestibility mechanism of soy protein isolate hydrolysate on natural starches with different crystal types.

The effects of soy protein isolate hydrolysate (SPIH) on the physicochemical properties and digestive characteristics of three starch types (wheat, potato, and pea) were investigated. Fourier-transform infrared spectroscopy and molecular dynamics simulations showed that hydrogen bonds were the driving force of the interaction between SPIH and starch. Furthermore, the SPIH was predicted to preferentially bind to the terminal region of starch using molecular dynamics simulations. Compared to pure starch, adding 20 % SPIH to wheat starch, potato starch, and pea starch, the content of resistant starch increased by 39.71 %, 125.66 % and 37.83 %, respectively. Both the radial distribution function (RDF) and low field-nuclear magnetic resonance (LF-NMR) showed that SPIH reduced the flow of water molecules in starch, indicating that SPIH competed with starch for water molecules. Multiple characterization experiments and molecular dynamics simulations confirmed that the anti-digestibility mechanism of SPIH on natural starches with different crystal types could be attributed to the interaction between starch and SPIH, which decreased the catalytic efficiency of amylase. This study clarified the anti-digestibility mechanism of SPIH on natural starches, which provides new insights into the production of low-glycemic index foods for the diabetic population.

Left atrial appendage closure in patients with left atrial appendage thrombus guided by intracardiac echocardiography.

BACKGROUND: Data regarding left atrial appendage closure (LAAC) in patients with left atrial appendage (LAA) thrombus are limited. Recently published cases have mostly been guided by transesophageal echocardiography. Intracardiac echocardiography (ICE) is now widely used during LAAC procedures. OBJECTIVE: This is the first study to report the feasibility of LAAC in patients with LAA thrombus guided by ICE. METHODS: Patients with persistent LAA thrombus despite anticoagulation or contraindications to anticoagulation who underwent a modified ICE-guided LAAC procedure between June 2021 and April 2023 were included. Periprocedural events and clinical outcomes during follow-up were recorded. RESULTS: A total of 12 patients (mean age 65 ± 7 years; 92% male) were included: 10 with persistent LAA thrombus and 2 with contraindications to anticoagulation. Most of the thrombus was at the apex (n = 6), followed by the body (n = 3) and the ostium (n = 3). A LAmbre device was used and successfully implanted in all patients with the guidance of ICE. No thrombotic material was retrieved from patients with the protection of cerebral protection device (n = 11). No patient experienced severe periprocedural complications. All patients completed transesophageal echocardiography follow-up, and no device-related thrombus or peridevice leak > 3 mm was detected. None of the patients experienced stroke/transient ischemic attack, systemic embolism, or major bleeding events during a median follow-up of 147 days (interquartile range 80-306 days). CONCLUSION: LAAC using the LAmbre device guided by ICE may be feasible in patients with LAA thrombus when performed by experienced operators.

Investigation on chain segment motions of various starch molecules under different glycerol-water system.

The molecular motion of starch at different glycerol concentrations (0, 20, 50, and 80 %) was investigated using Electron Paramagnetic Resonance (EPR) spectroscopy. Fourier-transform infrared (FTIR) spectroscopy and 1H nuclear magnetic resonance (1H NMR) spectroscopy confirmed that hydroxyl groups at the C2 and C3 positions of glucose units in corn starch (CS), waxy corn starch (WCS), and high amylose corn starch (HCS) were labeled with 4-amino-TEMPO. The crystallinities of CS, WCS, and HCS after spin-labeling decreased from 30.68 % to 3.21 %, 39.36 % to 1.65 %, and 28.54 % to 8.08 %, respectively. The pseudoplastic fluid properties of the spin-labeled starch remained shear-thin at different glycerol concentrations. EPR revealed the fast- and slow-motion components of the spin-labeled starch molecules dispersed in water. At a glycerol concentration of 20 %, the slow-motion component disappeared, indicating a faster rotational motion of the starch chain segments. As the glycerol concentration increased to 50 and 80 %, the rotational motion slowed because of high viscosity. In particular, the mobility of the spin-labeled WCS chains increased owing to easier access of glycerol and water to the branched structure. This study directly observed the dynamics of the molecular behavior of starch in glycerol-water systems.

Starch nanoparticles with predictable size prepared by alternate treatments of ball milling and ultrasonication.

In this study, starch nanoparticles (SNPs) were prepared by alternate treatments of liquid nitrogen ball milling and ultrasonication. The impact, shear and friction forces produced by ball milling, and acoustic cavitation and shear effects generated by ultrasonication disrupted starch granules to prepare SNPs. The SNPs possessed narrow particle size distribution (46.91-210.52 nm) and low polydispersity index (0.28-0.45). Additionally, the SNPs exhibited the irregular fragments with good uniformity. The relative crystallinity decreased from 34.91 % (waxy corn starch, WCS) to 0-25.91 % (SNPs), and the absorbance ratios of R1047/1022 decreased from 0.81 (WCS) to 0.60-0.76 (SNPs). The SNPs had lower thermal stability than that of WCS, characterized by a decrease in Td (temperature at maximum weight loss) from 309.39 °C (WCS) to 300.39-305.75 °C (SNPs). Furthermore, the SNPs exhibited excellent swelling power (3.48-28.02 %) and solubility (0.34-0.97 g/g). Notably, oil absorption capacity of the SNPs (9.77-15.67 g/g) was rather greater than that of WCS (1.33 g/g). Furthermore, the SNPs possessed the lower storage modulus (G'), loss modulus (G″) and viscosity than that of WCS. The SNPs with predictable size and high dispersion capability prepared in this study lay a foundation for expanding the application of SNPs.