110 results on '"Song Zuo"'
Search Results
2. Enhanced out-of-plane thermal conductivity of polyimide composite films by adding hollow cube-like boron nitride
- Author
-
Song Zuo, Maohua Li, Shaoxiong Xie, Jinpeng Luo, Lexiang Xu, Yan Shi, Ningxiang Lan, Lang Zhou, Jinhong Yu, Xiaomin Li, and Chuanqiang Yin
- Subjects
Process Chemistry and Technology ,Materials Chemistry ,Ceramics and Composites ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2023
3. Integrated exploration of experimentation and molecular simulation in ester-containing polyimide dielectrics
- Author
-
Jinpeng Luo, Hui Tong, Song Mo, Fei Zhou, Song Zuo, Chuanqiang Yin, Ju Xu, and Xiaomin Li
- Subjects
General Chemical Engineering ,General Chemistry - Abstract
An integrated exploration of experimentation and molecular simulation is conducted to achieve polyimide dielectrics with enhanced performance, as well as to analyze their dielectric mechanism in-depth.
- Published
- 2023
4. Dynamic Double Auctions: Toward First Best
- Author
-
Santiago R. Balseiro, Vahab Mirrokni, Renato Paes Leme, and Song Zuo
- Subjects
Management Science and Operations Research ,Computer Science Applications - Abstract
Efficient and Profit-Maximizing Dynamic Double Auctions for Two-Sided Markets Two-sided markets that enable sellers and buyers to trade have received considerable attention in the past decade. Prominent examples include online advertising, freelancing, and ride-hailing. In these markets, trade is coordinated by an intermediating platform that determines which parties should trade, collects payments from buyers, and transfers payments to sellers. How should trading mechanisms be designed when agents repeatedly trade over time? In the paper “Dynamic Double Auctions: Toward First Best,” Balseiro, Mirrokni, Paes Leme, and Zuo design dynamic double auctions that satisfy the following practical requirements: no positive transfers, that is, the platform never asks sellers to make payments nor are buyers ever paid; and periodic individual rationality, that is, agents should derive a nonnegative utility from every trade opportunity. This work provides mechanisms satisfying these requirements that, as the number of trading opportunities grows, are asymptotically efficient, budget balanced, and allow to extract the welfare generated by the market as profit.
- Published
- 2022
5. Lambl's excrescence and the safety of radiofrequency ablation for atrial fibrillation
- Author
-
Song Zuo, Xiaowen Bo, Liu He, Chao Jiang, Tianyi Dai, Jing Cui, Xu Li, Jiahui Wu, Xin Li, Songnan Li, Nian Liu, Chenxi Jiang, Rong Bai, Ribo Tang, Caihua Sang, Deyong Long, Xin Du, Jianzeng Dong, and Changsheng Ma
- Subjects
Male ,Treatment Outcome ,Aortic Valve ,Atrial Fibrillation ,Catheter Ablation ,Heart Valve Diseases ,Humans ,Female ,General Medicine ,Middle Aged ,Cardiology and Cardiovascular Medicine ,Echocardiography, Transesophageal ,Aged - Abstract
Lambl's excrescences (LEs) are excrescences with an extremely low incidence, mainly ultrasound diagnosed. Increasingly, LEs are detected by transesophageal echocardiography before catheter ablation, which raises safety concerns on whether LEs were associated with an embolism event during or after ablation, but clinical data are still lacking.We consecutively recruited 8081 patients with atrial fibrillation who underwent radiofrequency catheter ablation in Beijing Anzhen Hospital from Jan 1, 2017 to Dec 31, 2019. Total 21 patients (0.3%) were diagnosed as LEs with an average age of 70.8 ± 8.9 years, and 38.1% were male. Persistent atrial fibrillation (PeAF) and paroxysmal atrial fibrillation (PAF) accounted for 57.1% (12 cases) and 42.9% (nine cases), respectively. LEs were mostly frequently observed on the aortic valve (18 cases, 75%) and mitral valve (six cases, 25%). Precisely, the noncoronary cusp is ranked first in terms of the LEs presence (seven cases, 29.2%), followed by the right coronary cusp (six cases, 25.0%), the left coronary cusp (five cases, 20.8%), the anterior mitral valve (four cases, 16.7%), and the posterior mitral valve (two cases, 8.3%). During the ablation for LEs patients, the average procedure time was 96.0 ± 22.4 min; the average fluoroscopy time was 4.2 ± 0.8 min; the average total ablation time was 20.6 ± 5.6 min; and the mean hospital stay was 3.3 ± 0.6 days. No patients suffered from serious complications during the procedure. Furthermore, no cardiovascular event was observed during a follow-up of 19.1 ± 11.8 months.There was no clear association between LEs with intraoperative embolism events or cardiovascular events during the follow-up period.
- Published
- 2022
6. Epicardial Roof-Dependent Macro–Re-entrant Tachycardia After Ablation of Atrial Fibrillation
- Author
-
Yiwei Lai, Xueyuan Guo, Caihua Sang, Qi Guo, Mingyang Gao, Lihong Huang, Song Zuo, Xu Li, Chenxi Jiang, Songnan Li, Changyi Li, Nian Liu, Xiaoxia Liu, Xin Zhao, Wei Wang, Ribo Tang, Deyong Long, Xin Du, Jianzeng Dong, and Changsheng Ma
- Published
- 2023
7. Transseptal puncture in patients with septal occluder devices during catheter ablation of atrial fibrillation
- Author
-
Changsheng Ma, Yiwei Lai, Rong Bai, Chen-Xi Jiang, Xin Du, Jianzeng Dong, Song Zuo, Cai-Hua Sang, De-Yong Long, Ri-Bo Tang, Song-Nan Li, and Qi Guo
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,Septal Occluder Device ,business.industry ,medicine.medical_treatment ,Catheter ablation ,Atrial fibrillation ,Punctures ,medicine.disease ,Heart Septal Defects, Atrial ,Atrial septal defects ,Surgery ,Treatment Outcome ,Clinical Research ,Atrial Fibrillation ,Catheter Ablation ,medicine ,Balloon dilation ,Humans ,Fluoroscopy ,In patient ,Thrombus ,Cardiology and Cardiovascular Medicine ,business - Abstract
BACKGROUND: An atrial septal occluder (ASO) represents a major obstacle to the widespread adoption of atrial fibrillation (AF) catheter ablation in patients with prior atrial septal defect (ASD) closure. AIMS: The aim of this study was to describe the “sequential technique” of transseptal puncture (TSP) in AF patients with ASO. METHODS: Sixty-four drug-refractory AF patients with ASO who underwent catheter ablation in our centre from September 2007 to March 2020 were enrolled. RESULTS: Puncture through the native septum was achieved in 29 patients (Group A) and through the device in 35 patients (Group B). The mean diameter of the occluder was significantly larger in Group B than in Group A (31.6±4.6 mm vs 22.8±3.5 mm, p
- Published
- 2022
8. Autobidding Auctions in the Presence of User Costs
- Author
-
Yuan Deng, Jieming Mao, Vahab Mirrokni, Hanrui Zhang, and Song Zuo
- Subjects
FOS: Computer and information sciences ,Computer Science - Computer Science and Game Theory ,Computer Science and Game Theory (cs.GT) - Abstract
We study autobidding ad auctions with user costs, where each bidder is value-maximizing subject to a return-over-investment (ROI) constraint, and the seller aims to maximize the social welfare taking into consideration the user's cost of viewing an ad. We show that in the worst case, the approximation ratio of social welfare by running the vanilla VCG auctions with user costs could as bad as 0. To improve the performance of VCG, We propose a new variant of VCG based on properly chosen cost multipliers, and prove that there exist auction-dependent and bidder-dependent cost multipliers that guarantee approximation ratios of 1/2 and 1/4 respectively in terms of the social welfare.
- Published
- 2023
- Full Text
- View/download PDF
9. Optimal Mechanisms for a Value Maximizer: The Futility of Screening Targets
- Author
-
Santiago Balseiro, Yuan Deng, Jieming Mao, Vahab Mirrokni, and Song Zuo
- Subjects
History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2023
10. Catheter ablation for atrial fibrillation in patients with persistent left superior vena cava: Case series and systematic review
- Author
-
Mingyang, Gao, Yang, Bian, Lihong, Huang, Jingrui, Zhang, Changyi, Li, Nian, Liu, Xiaoxia, Liu, Song, Zuo, Xueyuan, Guo, Wei, Wang, Xin, Zhao, Deyong, Long, Caihua, Sang, Ribo, Tang, Songnan, Li, Jianzeng, Dong, and Changsheng, Ma
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
IntroductionPersistent left superior vena cava (PLSVC) is the most common form of thoracic venous abnormality. Catheter ablation (CA) for atrial fibrillation (AF) can be complicated by the existence of PLSVC, which could act as an important arrhythmogenic mechanism in AF.Methods and resultsWe reported a case series of patients with PLSVC who underwent CA for AF at our center between 2018 and 2021. A systematic search was also performed on PubMed, EMBASE, and Web of Science for research reporting CA for AF in patients with PLSVC. Sixteen patients with PLSVC were identified at our center. Ablation targeting PLSVC was performed in 5 patients in the index procedures and in four patients receiving redo procedures. One patient experienced acute procedure failure. After a median follow-up period of 15 months, only 6 (37.5%) patients remained free from AF/atrial tachycardia (AT) after a single procedure. In the systematic review, 11 studies with 167 patients were identified. Based on the included studies, the estimated prevalence of PLSVC in patients undergoing CA for AF was 0.7%. Ablation targeting PLSVC was performed in 121 (74.7%) patients. Major complications in patients with PLSVC receiving AF ablation procedure included four cases of cardiac tamponades (2%), three cases of cardiac effusion (1.5%), one case of ischemic stroke, and three cases of phrenic nerve injury (1.5%) (one left phrenic nerve and two right phrenic nerve). Pooled analysis revealed that after a median follow-up period of 15.6 months (IQR 12.0–74.0 months), the long-term AF/AT-free rate was 70.6% (95% CI 62.8–78.4%, I2 = 0.0%) (Central illustration). Different ablation strategies for PLSVC were summarized and discussed in the systematic review.ConclusionIn patients with PLSVC, recurrence of atrial arrhythmia after CA for AF is relatively common. Ablation aiming for PLSVC isolation is necessitated in most patients. The overall risk of procedural complications was within an acceptable range.
- Published
- 2022
11. Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?
- Author
-
Ming‐Yang Gao, Cai‐Hua Sang, Li‐Hong Huang, Yi‐Wei Lai, Qi Guo, Xiao‐Xia Liu, Song Zuo, Chang‐Yi Li, Wei Wang, Xue‐Yuan Guo, Xin Zhao, Song‐Nan Li, Chen‐Xi Jiang, Nian Liu, Ri‐Bo Tang, Xin Du, De‐Yong Long, Jian‐Zeng Dong, and Chang‐Sheng Ma
- Subjects
General Medicine ,Cardiology and Cardiovascular Medicine - Abstract
Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation.A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated.PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022).EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process.PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.
- Published
- 2022
12. Angular-Shaped Boron Nitride Nanosheets with a High Aspect Ratio to Improve the Out-of-Plane Thermal Conductivity of Polyimide Composite Films
- Author
-
Song Zuo, Yu Lan, Jinpeng Luo, Fei Zhou, Lexiang Xu, Shaoxiong Xie, Xiuqin Wei, Lang Zhou, Lei Ma, Xiaomin Li, and Chuanqiang Yin
- Subjects
General Chemical Engineering ,General Chemistry - Abstract
Polyimide/boron nitride nanosheet (PI/BNNS) composite films have potential applications in the field of electrical devices due to the superior thermal conductivity and outstanding insulating properties of the boron nitride nanosheet. In this study, the boron nitride nanosheet (BNNS-t) was prepared by the template method using sodium chloride as the template, and B
- Published
- 2022
13. Risk Factors for Left Ventricular Thrombus Formation in Patients with Dilated Cardiomyopathy
- Author
-
Hao-Sheng Wu, Jian-Zeng Dong, Xin Du, Rong Hu, Chang-Qi Jia, Xu Li, Jia-Hui Wu, Yan-Fei Ruan, Rong-Hui Yu, De-Yong Long, Man Ning, Cai-Hua Sang, Chen-Xi Jiang, Rong Bai, Song-Nan Wen, Nian Liu, Song-Nan Li, Wei Wang, Xue-Yuan Guo, Xin Zhao, Song Zuo, Yi-Kai Cui, Ri-Bo Tang, and Chang-Sheng Ma
- Subjects
Hematology ,Cardiology and Cardiovascular Medicine - Abstract
Background Left ventricular thrombus (LVT) is a common complication of dilated cardiomyopathy (DCM), causing morbidity and mortality. Methods This study retrospectively analyzed patients with DCM from January 2002 to August 2020 in Beijing Anzhen Hospital. Clinical characteristics were compared between the LVT group and the age and sex 1:4 matched with the LVT absent group. The receiver operator characteristic (ROC) curve was plotted to evaluate the diagnostic value of D-dimer predicting LVT occurrence in DCM. Results A total of 3,134 patients were screened, and LVT was detected in 72 (2.3%) patients on echocardiography. The patients with LVT had higher D-dimer, fibrinogen, and lower systolic blood pressure than those without LVT. The ejection fraction (EF) was lower and left ventricular end-systolic diameter was larger in the LVT group. Severe mitral regurgitation (MR) was more common in the LVT absent groups. The prevalence of atrial fibrillation was lower in the LVT group. The ROC curve analysis yielded an optimal cut-off value of 444 ng/mL DDU (D-dimer units) for D-dimer to predict the presence of LVT. Multivariable binary logistic regression analysis revealed that EF (OR = 0.90, 95% CI = 0.86–0.95), severe MR (OR = 0.19, 95% CI = 0.08–0.48), and D-dimer level (OR = 15.4, 95% CI = 7.58–31.4) were independently associated with LVT formation. Conclusion This study suggested that elevated D-dimer levels (>444 ng/mL DDU) and reduced EF were independently associated with increased risk of LVT formation. Severe MR could decrease the incidence of LVT.
- Published
- 2022
14. Fascicular ventricular tachycardia arising from the left side His and its adjacent region: a subset of upper septal idiopathic left ventricular tachycardia
- Author
-
Meng-Meng Li, Xue-Ying Wu, Chen-Xi Jiang, Man Ning, Cai-Hua Sang, Song-Nan Li, Xue-Yuan Guo, Wei Wang, Xin Zhao, Ri-Bo Tang, Song Zuo, Xiang-Yi Kong, Wen-Li Dai, Yang Yang, Xu Li, De-Yong Long, Jian-Zeng Dong, and Chang-Sheng Ma
- Subjects
Physiology (medical) ,Cardiology and Cardiovascular Medicine - Abstract
Aims Fascicular ventricle tachycardia (FVT) arising from the proximal aspect of left His-Purkinje system (HPS) has not been specially addressed. Current study was to investigate its clinical, electrocardiographic, and electrophysiological characteristics. Methods and results Eighteen patients who were identified as this rare FVT were consecutively enrolled, and their scalar electrocardiogram and electrophysiological data were collected and analysed. The ventricular tachycardia (VT) morphology was similar to sinus rhythm (SR) in eight patients, left bundle branch block type in one patient, right bundle branch block type in seven patients, and both narrow and wide QRS type in two patients. During VT, right-sided His potential preceded the QRS with His-ventricle (H-V) interval of 36.3 ± 12.4 ms, which was shorter than that during SR (−51.4 ± 8.6 ms) (P = 0.002). The earliest Purkinje potentials (PPs) were recorded within 7 ± 3 mm of left-side His and preceded the QRS by 49.1 ± 14.0 ms. Mapping along the left anterior fascicle and left posterior fascicle revealed an antegrade activation sequence in all with no P1 potentials recorded. In the two patients with two VT morphologies, the earliest PP was documented at the same site, and the activation sequence of HPS remained antegrade. Ablation at the earliest PP successfully eliminated the tachycardia, except one patient who developed complete atrial-ventricular block and two patients who abandoned ablations. After at least 12 months follow-up, 15 patients were free from any recurrences. Conclusions Fascicular ventricle tachycardia arising from the proximal aspect of left HPS was featured by recording slightly shorter H-V interval and absence of P1 potentials. Termination of VT requires ablation at the left-sided His or its adjacent region.
- Published
- 2022
15. Comparison of prognosis and outcomes of catheter ablation versus drug therapy in patients with atrial fibrillation and stable coronary artery disease: A prospective <scp>propensity‐score</scp> matched cohort study
- Author
-
Jian-Zeng Dong, Cai-Hua Sang, Changsheng Ma, Rong-Hui Yu, Liu He, Hao-Sheng Wu, Song Zuo, Wei Wang, Chen-Xi Jiang, Xuan Chen, Song-Nan Li, Yi-Kai Cui, Jia-Hui Wu, Rong Hu, Man Ning, Xu Li, De-Yong Long, Song-Nan Wen, Xin Zhao, Chang-qi Jia, Nian Liu, Xue-Yuan Guo, Rong Bai, Xin Du, Ri-Bo Tang, and Shu-Tao Huang
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Clinical Investigations ,Catheter ablation ,Subgroup analysis ,Coronary Artery Disease ,Cohort Studies ,Coronary artery disease ,Pharmacotherapy ,Recurrence ,Risk Factors ,Internal medicine ,Atrial Fibrillation ,catheter ablation ,medicine ,Clinical endpoint ,Humans ,Prospective Studies ,Risk factor ,business.industry ,Atrial fibrillation ,General Medicine ,Prognosis ,medicine.disease ,Treatment Outcome ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Scad ,Anti-Arrhythmia Agents - Abstract
Background Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. Hypothesis To investigate the prognosis of catheter ablation versus drug therapy in patients with AF and SCAD. Methods In total, 25 512 patients with AF in the Chinese AF Registry between 2011 and 2019 were screened for SCAD. 815 patients with AF and SCAD underwent catheter ablation therapy were matched with patients by drug therapy in a 1:1 ratio. Primary end point was composite of thromboembolism, coronary events, major bleeding, and all‐cause death. The secondary endpoints were each component of the primary endpoint and AF recurrence. Results Over a median follow‐up of 45 ± 23 months, the patients in the catheter ablation group had a higher AF recurrence‐free rate (53.50% vs. 18.41%, p
- Published
- 2021
16. Non-catalytic vapor synthesis of α-Si3N4 nanowhiskers via direct nitridation of silicon powders
- Author
-
Fei Zhou, Lang Zhou, Yu Lan, Yi Huang, Song Zuo, Chuanqiang Yin, Xiaomin Li, and Zongming Pan
- Subjects
010302 applied physics ,Materials science ,Silicon ,Process Chemistry and Technology ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Catalysis ,Crystal ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Non catalytic ,0210 nano-technology ,Layer (electronics) - Abstract
Single crystalline α-Si3N4 nanowhiskers were synthesized by direct nitridation of the NH3-pretreated silicon powders under N2/H2 atmosphere without adding any catalysts. The phase composition and microstructure of the as-obtained products were investigated. It is shown that the NH3 pretreatment has a great influence on the phase and microstructure of the products. With NH3 pretreatment, single crystalline α-Si3N4 nanowhiskers were obtained. Whereas, the dominant β-Si3N4 particles were formed without NH3 pretreatment. The isolated α-Si3N4 crystal nuclei and the relatively thick oxide layer were formed on the surface of the silicon particles after pretreating by NH3. The growth of the α-Si3N4 nanowhiskers is obeyed the vapor-solid (VS) mechanism.
- Published
- 2021
17. Revisiting the characteristics and ablation strategy of biatrial tachycardias: a case series and systematic review
- Author
-
Yiwei Lai, Qi Guo, Caihua Sang, Mingyang Gao, Lihong Huang, Song Zuo, Zhibing Lu, Chenxi Jiang, Songnan Li, Xueyuan Guo, Wei Wang, Nian Liu, Changyi Li, Xiaoxia Liu, Xin Zhao, Ribo Tang, Deyong Long, Xin Du, Jianzeng Dong, and Changsheng Ma
- Subjects
Physiology (medical) ,Cardiology and Cardiovascular Medicine - Abstract
Aims To describe the role of left atrial (LA) epicardial conduction and targets of ablation in biatrial tachycardias (BiATs). Methods and results Consecutive patients with BiAT diagnosed by high-density mapping and appropriate entrainment were enrolled. A systematic review of case reports or series was then performed. Biatrial tachycardia was identified in 20 patients aged 63.5 ± 11.1 years. Among them, eight had LA epicardial conduction, including four via the ligament of Marshall, two via myocardial fibres between the great cardiac vein (GCV) and LA, one via septopulmonary bundle, and one via myocardial fibres between the posterior wall and coronary sinus. Ablation was targeted at the anatomical isthmus in 14, including 5 undergoing vein of Marshall ethanol infusion and 2 undergoing ablation in the GCV. Another six underwent ablation at interatrial connections, including one with septopulmonary bundle at the fossa ovalis and five at the atrial insertions of Bachmann’s bundle. After a mean follow-up of 8.7 ± 3.8 months, five patients had recurrence of atrial fibrillation/flutter. Systematic review enrolled 87 patients in previous and the present reports, showing a higher risk of impairment in atrial physiology in those targeting interatrial connections (30.4 vs. 5.0%, P < 0.001) but no significant difference in short- and long-term effectiveness. Conclusion Left atrial epicardial conduction is common in BiATs and affects the ablation strategy. Atrial physiology is a major concern in selecting the target of intervention.
- Published
- 2022
18. The adjunctive effect for left pulmonary vein isolation of vein of Marshall ethanol infusion in persistent atrial fibrillation
- Author
-
Lihong Huang, Mingyang Gao, Yiwei Lai, Qi Guo, Songnan Li, Changyi Li, Nian Liu, Wei Wang, Xiaoxia Liu, Song Zuo, Xueyuan Guo, Xin Zhao, Chenxi Jiang, Caihua Sang, Ribo Tang, Deyong Long, Xin Du, Jianzeng Dong, and Chang-sheng Ma
- Subjects
Physiology (medical) ,Cardiology and Cardiovascular Medicine - Abstract
ObjectiveThis study sought to assess the effect of ethanol infusion into the vein of Marshall (EIVOM) on the acute success of left pulmonary vein (LPV) isolation in persistent atrial fibrillation (PeAF).Methods and resultsA total of 313 patients with drug-resistant PeAF were enrolled (135 in Group 1 and 178 in Group 2). In Group 1, EIVOM was firstly performed, followed by radiofrequency ablation (RFA) including bilateral pulmonary vein isolation (PVI) and linear ablation at roofline, cavotricuspid isthmus, and mitral isthmus (MI). In Group 2, PVI and linear ablations were completed with RFA. First-pass isolation of the LPV was achieved in 119 (88.1%) and 132 (74.2%) patients in Groups 1 and 2, respectively (P = 0.002). The rate of acute pulmonary vein reconnection (PVR) was significantly lower in Group 1 (9.6% vs. 22.5%, P = 0.003). About half of acute PVR occurred in the carina with or without EIVOM.ConclusionEIVOM is effective in achieving a higher first-pass isolation and a lower acute PVR of LPV in PeAF.
- Published
- 2022
19. Optimal Mechanisms for Value Maximizers with Budget Constraints via Target Clipping
- Author
-
Santiago Balseiro, Yuan Deng, Jieming Mao, Vahab Mirrokni, and Song Zuo
- Published
- 2022
20. Direct autotransfusion in the management of acute pericardial tamponade during catheter ablation for atrial fibrillation: An imperfect but practical method
- Author
-
Xin Zhao, Jian-feng Liu, Xin Su, De-yong Long, Cai-hua Sang, Ri-bo Tang, Rong-Hui Yu, Nian Liu, Chen-xi Jiang, Song-nan Li, Xue-yuan Guo, Wei Wang, Song Zuo, Jian-zeng Dong, and Chang-sheng Ma
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
BackgroundAcute pericardial tamponade (APT) is one of the most serious complications of catheter ablation for atrial fibrillation (AF-CA). Direct autotransfusion (DAT) is a method of reinjecting pericardial blood directly into patients through vein access without a cell-salvage system. Data regarding DAT for APT are rare and provide limited information. Our present study aims to further investigate the safety and feasibility of DAT in the management of APT during the AF-CA procedure.Methods and resultsWe retrospectively reviewed 73 cases of APT in the perioperative period of AF-CA from January 2014 to October 2021 at our institution, among whom 46 were treated with DAT. All included patients successfully received emergency pericardiocentesis through subxiphoid access guided by X-ray. Larger volumes of aspirated pericardial blood (658.4 ± 545.2 vs. 521.2 ± 464.9 ml), higher rates of bridging anticoagulation (67.4 vs. 37.0%), and surgical repair (6 vs. 0) were observed in patients with DAT than without. Moreover, patients with DAT were less likely to complete AF-CA procedures (32/46 vs. 25/27) and had a lower incidence of APT first presented in the ward (delayed presentation) (8/46 vs. 9/27). There was no difference in major adverse events (death/disseminated intravascular coagulation/multiple organ dysfunction syndrome and clinical thrombosis) (0/0/1/0 vs. 1/0/0/0), other potential DAT-related complications (fever/infection and deep venous thrombosis) (8/5/2 vs. 5/3/1), and length of hospital stay (11.4 ± 11.6 vs. 8.3 ± 4.7 d) between two groups.ConclusionDAT could be a feasible and safe method to deal with APT during AF-CA procedure.
- Published
- 2022
21. Thermomechanical coupling multi-objective topology optimization of anisotropic structures based on the element-free Galerkin method
- Author
-
Liu Tingxian, Jiangpeng Peng, Gong Shuguang, Shusen Wang, Qing-Song Zuo, and Zhang Jianping
- Subjects
Control and Optimization ,Element free galerkin ,Materials science ,Thermomechanical coupling ,Applied Mathematics ,Mathematical analysis ,Topology optimization ,Management Science and Operations Research ,Anisotropy ,Galerkin method ,Industrial and Manufacturing Engineering ,Physics::Geophysics ,Computer Science Applications - Abstract
The mathematical model of thermomechanical coupling multi-objective topology optimization for anisotropic structures was established using the element-free Galerkin (EFG) method, and the weighted f...
- Published
- 2021
22. GFANet: Gated Fusion Attention Network for skin lesion segmentation
- Author
-
Shihan Qiu, Chengfei Li, Yue Feng, Song Zuo, Huijie Liang, and Ao Xu
- Subjects
Health Informatics ,Computer Science Applications - Published
- 2023
23. Calibrated Click-Through Auctions
- Author
-
Dirk Bergemann, Paul Dütting, Renato Paes Leme, and Song Zuo
- Published
- 2022
24. Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease
- Author
-
Yi‐Kai Cui, Jian‐Zeng Dong, Xin Du, Rong Hu, Liu He, De‐Yong Long, Rong Bai, Rong‐Hui Yu, Cai‐Hua Sang, Chen‐Xi Jiang, Nian Liu, Song‐Nan Li, Wei Wang, Xue‐Yuan Guo, Xin Zhao, Song Zuo, Ri‐Bo Tang, and Chang‐Sheng Ma
- Subjects
Treatment Outcome ,Recurrence ,Thromboembolism ,Atrial Fibrillation ,Catheter Ablation ,Humans ,Female ,General Medicine ,Coronary Artery Disease ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,Cardiology and Cardiovascular Medicine - Abstract
Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD.In total, 12,104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death.Over a mean follow-up of 46.0 ± 18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0% vs. 41.9%, p = .03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9% vs. 31.2%;p = .04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], p = .03). The composite secondary endpoints were significantly higher in the SCAD group (12.70% vs. 8.54%, p = .02), mainly due to thromboembolism events (8.16% vs. 4.41%, p .01).SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD.
- Published
- 2022
25. Physical activity and atrial tachyarrhythmia recurrence in atrial fibrillation patients after catheter ablation
- Author
-
Xiaoyi Yang, Zhaoxu Jia, Yingchun Zhou, San-Shuai Chang, Changsheng Ma, Xue-Yuan Guo, Rong Bai, Song Zuo, Xin Du, Jingye Li, Shangxin Lu, Shijun Xia, Ri-Bo Tang, Jian-Zeng Dong, and Cai-Hua Sang
- Subjects
Male ,China ,medicine.medical_specialty ,Heart disease ,medicine.medical_treatment ,Population ,Catheter ablation ,030204 cardiovascular system & hematology ,Lower risk ,03 medical and health sciences ,0302 clinical medicine ,Recurrence ,Tachycardia ,Internal medicine ,Atrial Fibrillation ,medicine ,Humans ,030212 general & internal medicine ,education ,Exercise ,Aged ,education.field_of_study ,business.industry ,valvular heart disease ,Atrial fibrillation ,General Medicine ,Odds ratio ,Middle Aged ,medicine.disease ,Confidence interval ,Catheter Ablation ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background The association between physical activity (PA) and atrial tachyarrhythmia (AT) recurrence after ablation for atrial fibrillation (AF) remains unclear. Methods We consecutively enrolled 496 patients treated with AF ablation therapy in Beijing Anzhen Hospital. After excluding six patients with valvular heart disease, seven patients with congenital heart disease, 33 patients lost to follow-up, and 14 patients who did not provide PA level during follow-ups, 436 patients had their PA level assessed by the International Physical Activity Questionnaire-Short Form before ablation and each time of follow-up. The association between PA level (measured at the time closest to AT recurrence, or the end of 12-month follow-up if no AT recurrence), as well as active PA during follow-up, and postablation AT recurrence was tested by multivariate logistic regression. Results Of the enrolled patients, 134 (30.7%) patients experienced AT recurrence in the first 12 months postablation. Compared to patients with low PA, patients with moderate or high PA had a lower risk of AT recurrence (odds ratio [OR] = .44; 95% confidence interval [CI], .25-.80; P = .01 for patients with moderate PA; and OR = .43 [95% CI, .21-.85], P = .02 for patients with high PA). Compared to patients without active PA, patients with active PA had a lower risk of AT recurrence (OR = .44 [95% CI, .27-.70], P Conclusions Moderate and high PA are associated with a lower risk of AT recurrence after AF ablation. Active PA during follow-up is also associated with a significantly lower risk of AT recurrence in the postablation AF population.
- Published
- 2020
26. Effect of vacuum cooling on stability of macro‐porous sausage during refrigerated storage—Vacuum‐cooled sausage has a longer shelf life
- Author
-
Song Zuo, Yuchen Luan, Xiao-yan Song, Baolin Liu, and Guo Zhiyu
- Subjects
Air cooling ,sausage ,macro‐porous ,storage ,vacuum cooling ,Materials science ,Water activity ,0402 animal and dairy science ,Refrigeration ,lcsh:TX341-641 ,04 agricultural and veterinary sciences ,Shelf life ,040401 food science ,040201 dairy & animal science ,0404 agricultural biotechnology ,Lipid oxidation ,Vacuum cooling ,Food science ,Porosity ,lcsh:Nutrition. Foods and food supply ,Water content ,Original Research ,Food Science - Abstract
In this study, two types of cooling methods (vacuum cooling and air cooling) were used to cool cooked macro‐porous sausage. Alterations in the microbiological conditions, pH, instrumental color (L*, a*, and b*), total volatile nitrogenous bases (TVB‐N), lipid oxidation (TBARS), water activity (aW), moisture content, and texture indicators were evaluated to determine sausages' quality changes during storage under refrigeration for up to 10 days. In general, the shelf life of sausages chilled by vacuum cooling (8 days) was similar to that of sausages cooled by air cooling (9 days). For pH, no significant difference (p > .05) was obtained between two cooling methods. However, vacuum‐cooled sausages have lower L* value (p, Two types of cooling methods (vacuum cooling and air cooling) were used to cool cooked macro‐porous sausages, which will store almost 10 days at 4°C. Storage stability is primarily assessed by physical, chemical, and microbial parameters.
- Published
- 2020
27. Non‐Clairvoyant Dynamic Mechanism Design
- Author
-
Song Zuo, Renato Paes Leme, Pingzhong Tang, and Vahab Mirrokni
- Subjects
Bank account ,Economics and Econometrics ,Mathematical optimization ,Mechanism design ,Computer science ,0502 economics and business ,05 social sciences ,Revenue ,Revenue optimization ,050207 economics ,050205 econometrics ,Power (physics) - Abstract
We introduce a new family of dynamic mechanisms that restricts sellers from using future distributional knowledge. Since the allocation and pricing of each auction period do not depend on the type distributions of future periods, we call this family of dynamic mechanisms non‐clairvoyant.We develop a framework (bank account mechanisms) for characterizing, designing, and proving lower bounds for dynamic mechanisms (clairvoyant or non‐clairvoyant). We use the same methods to compare the revenue extraction power of clairvoyant and non‐clairvoyant dynamic mechanisms.
- Published
- 2020
28. Polymerization-induced self-assembly of side-chain liquid crystalline copolymers by dissipative particle dynamics simulation
- Author
-
Song Zuo, Weisheng Feng, Fan Liu, Xuepei Xu, Xinfeng Tao, Liquan Wang, Honglai Liu, and Shaoliang Lin
- Subjects
Polymers and Plastics ,Organic Chemistry ,Materials Chemistry - Published
- 2023
29. Non-Clairvoyant Dynamic Mechanism Design with Budget Constraints and Beyond
- Author
-
Yuan Deng, Song Zuo, and Vahab Mirrokni
- Subjects
Lossless compression ,Mechanism design ,Generality ,Mathematical optimization ,Computer science ,Revenue ,Rationality ,State (computer science) ,Mechanism (sociology) ,Budget constraint - Abstract
We provide a general design framework for dynamic mechanisms under complex environments, coined Lossless History Compression mechanisms. Lossless history compression mechanisms compress the history into a state carrying the least historical information without losing any generality in terms of either revenue or welfare. In particular, the characterization works for almost arbitrary constraints on the outcomes, and any objective function defined on the historical reports, allocations, and the cumulative payments. We then apply our framework to design a non-clairvoyant dynamic mechanism under budget and ex-post individual rationality constraints that is dynamic incentive-compatible and achieves non-trivial revenue performance, even without any knowledge about the future. In particular, our dynamic mechanism obtains a constant approximation to the optimal dynamic mechanism having access to all information in advance. To the best of our knowledge, this is the first dynamic mechanism that achieves a constant approximation and strictly respects dynamic incentive-compatibility and budget constraints without relying on any forecasts of the future.
- Published
- 2021
30. The Landscape of Auto-bidding Auctions: Value versus Utility Maximization
- Author
-
Song Zuo, Vahab Mirrokni, Santiago Balseiro, Jieming Mao, and Yuan Deng
- Subjects
TheoryofComputation_MISCELLANEOUS ,Microeconomics ,Mechanism design ,business.industry ,Value (economics) ,Revenue ,Common value auction ,Maximization ,Bidding ,business ,Constraint (mathematics) ,Online advertising ,Private information retrieval - Abstract
Internet advertisers are increasingly adopting automated bidders to buy advertising opportunities. Automated bidders simplify the procurement process by allowing advertisers to specify their goals and then bidding on their behalf in the auctions that are used to sell advertising slots. One popular goal adopted by advertisers is to maximize their clicks (or conversions) subject to a return on spend (RoS) constraint, which imposes that the ratio of total value to total spend is greater than a target ratio specified by the advertisers. The emergence of automated bidders brings into question whether the standard mechanisms used to sell ads are still effective in this new landscape. Thus motivated, in this paper, we study the problem of characterizing optimal mechanisms for selling an item to one of multiple agents with return on spend constraints when either the values or target ratios are private. We consider two objectives for the agents: value maximization, which is becoming the prevalent objective in advertising markets, and utility maximization, which is the de facto paradigm in economic theory. Our goal is to understand the impact of the agents' private information and their objectives on the seller's revenue, and determine whether the first-best revenue, which is the optimal revenue when all the private information is public, is achievable. We show that first-best revenue is achievable for value-maximizing buyers when either the target ratio or the values are private, but not when both are private. In the case of utility-maximizing buyers, first-best is never achievable and we characterize revenue-maximizing mechanisms.
- Published
- 2021
31. Effectiveness of ethanol infusion into the vein of Marshall combined with a fixed anatomical ablation strategy (the 'upgraded 2C3L' approach) for catheter ablation of persistent atrial fibrillation
- Author
-
Wei Wang, Xin Zhao, Song-Nan Li, Song Zuo, Cai-Hua Sang, Meng-Meng Li, Chang-Yi Li, Chao Jiang, Jian-Zeng Dong, Changsheng Ma, Xiangfei Liu, Yiwei Lai, De-Yong Long, Xin Du, Ri-Bo Tang, Xiao-Xia Liu, Nian Liu, Zhibing Lu, Weili Ge, Chen-Xi Jiang, Qi Guo, Xue-Yuan Guo, and Rong Bai
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Catheter ablation ,Cardioversion ,Pulmonary vein ,Recurrence ,Tachycardia ,Physiology (medical) ,Internal medicine ,Atrial Fibrillation ,medicine ,Humans ,Vein ,Atrial tachycardia ,Ethanol ,business.industry ,Atrial fibrillation ,Ablation ,medicine.disease ,Treatment Outcome ,medicine.anatomical_structure ,Pulmonary Veins ,Catheter Ablation ,Cardiology ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Left Pulmonary Vein - Abstract
INTRODUCTION Linear ablation in addition to pulmonary vein antrum isolation (PVAI) has failed to improve the success rate for persistent atrial fibrillation (PeAF), due to incomplete block of ablation lines, especially in the mitral isthmus (MI). METHODS AND RESULTS The study enrolled 191 patients (66 in group 1 and 125 in group 2). In group 1, ethanol infusion into the vein of Marshall was first performed, followed by radiofrequency (RF) applications targeting bilateral PVAI and bidirectional block in the roofline, cavotricuspid isthmus, and MI. In group 2, PVAI and the three linear ablations were completed using only RF energy. MI block was achieved in 63 (95.5%) and 101 (80.8%) patients in groups 1 and 2, respectively (p = .006). Patients in group 1 had shorter ablation time for left pulmonary vein antrum (8.15 vs. 12.59 min, p
- Published
- 2021
32. Ibrutinib promotes atrial fibrillation by inducing structural remodeling and calcium dysregulation in the atrium
- Author
-
Nian Liu, Qianqian Zhao, Shijun Xia, Changsheng Ma, Yanwei Xing, Xin Du, Linling Li, Le Jiang, Xin Zhao, Yanfei Ruan, Song Zuo, Xiao-Yan Wu, and Rong Bai
- Subjects
medicine.medical_specialty ,Antineoplastic Agents ,030204 cardiovascular system & hematology ,Afterdepolarization ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Piperidines ,Oral administration ,Physiology (medical) ,Ca2+/calmodulin-dependent protein kinase ,Internal medicine ,Atrial Fibrillation ,Agammaglobulinaemia Tyrosine Kinase ,medicine ,Animals ,Bruton's tyrosine kinase ,Myocytes, Cardiac ,Calcium Signaling ,Heart Atria ,030212 general & internal medicine ,Atrium (heart) ,biology ,business.industry ,Adenine ,Atrial fibrillation ,Atrial Remodeling ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,Disease Models, Animal ,Pyrimidines ,medicine.anatomical_structure ,chemistry ,Echocardiography ,Ibrutinib ,cardiovascular system ,biology.protein ,Cardiology ,Pyrazoles ,Calcium ,Myocardial fibrosis ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Ibrutinib is a novel antitumor drug that targets Bruton tyrosine kinase for treatment of chronic lymphocytic leukemia. Atrial fibrillation (AF) occurs in 5%–9% of patients during treatment, but the underlying mechanisms remain unclear. Objective The purpose of this study was to develop a mouse model of ibrutinib-induced AF and investigate its proarrhythmic mechanisms. Methods In C57BI/6 mice in the ibrutinib and control groups, ibrutinib (25 mg/kg/d) or vehicle (hydroxypropy1-β-cyclodextrin), respectively, was administered orally for 4 weeks. Transesophageal burst stimulation then was used to induced AF. To evaluate the underlying mechanism of AF, cardiac echocardiography was performed. Ca2+ handling and action potentials in atrial myocytes were evaluated. Results Compared with the control group, the ibrutinib group showed (1) a higher incidence and longer duration of AF with transesophageal burst stimulation; (2) increased left atrial mass, as indicated by echocardiography; (3) significant myocardial fibrosis in the left atrium on Masson trichrome staining; (4) Ca2+ handling disorders in atrial myocytes, such as reduced Ca2+ transient amplitude, enhanced spontaneous Ca2+ release, and reduced sarcoplasmic Ca2+ capacity; (5) enhanced delayed afterdepolarization in atrial myocytes; and (6) increased CaMKII expression and phosphorylation of RyR2-Ser2814 and PLN-Thr17. Conclusion The present study established a mouse model of AF by oral administration of ibrutinib for 4 weeks. The arrhythmogenic mechanisms underlying this model likely are associated with structural remodeling and Ca2+ handling disorders in the atrium.
- Published
- 2019
33. Learning Optimal Strategies to Commit To
- Author
-
Song Zuo, Weiran Shen, Binghui Peng, and Pingzhong Tang
- Subjects
Computer science ,media_common.quotation_subject ,Normal-form game ,Stochastic game ,02 engineering and technology ,General Medicine ,Commit ,010501 environmental sciences ,01 natural sciences ,0202 electrical engineering, electronic engineering, information engineering ,Stackelberg competition ,020201 artificial intelligence & image processing ,Function (engineering) ,Mathematical economics ,0105 earth and related environmental sciences ,media_common - Abstract
Over the past decades, various theories and algorithms have been developed under the framework of Stackelberg games and part of these innovations have been fielded under the scenarios of national security defenses and wildlife protections. However, one of the remaining difficulties in the literature is that most of theoretical works assume full information of the payoff matrices, while in applications, the leader often has no prior knowledge about the follower’s payoff matrix, but may gain information about the follower’s utility function through repeated interactions. In this paper, we study the problem of learning the optimal leader strategy in Stackelberg (security) games and develop novel algorithms as well as new hardness results.
- Published
- 2019
34. Linc00152 knockdown inactivates the Akt/mTOR and Notch1 pathways to exert its anti-hemangioma effect
- Author
-
Yuchun Ma, Changxian Dong, Li Xiao, Song Zuo, Tengfei Ren, Miaomiao Li, Bin Sun, Yubin Gong, and Yanlin Wang
- Subjects
Male ,0301 basic medicine ,030226 pharmacology & pharmacy ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,0302 clinical medicine ,Western blot ,Cell Line, Tumor ,medicine ,Humans ,Receptor, Notch1 ,General Pharmacology, Toxicology and Pharmaceutics ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Gene knockdown ,Oncogene ,medicine.diagnostic_test ,Chemistry ,Cell growth ,TOR Serine-Threonine Kinases ,Endothelial Cells ,Infant ,General Medicine ,In vitro ,Up-Regulation ,030104 developmental biology ,Apoptosis ,Child, Preschool ,Gene Knockdown Techniques ,Cancer research ,Female ,RNA, Long Noncoding ,Hemangioma ,Proto-Oncogene Proteins c-akt ,Signal Transduction - Abstract
Aims Infantile hemangioma (IH) is one of the most common benign vascular tumors occurred in infants. Linc00152 is a kind of long non-coding RNAs (lncRNAs) and acts as a tumor oncogene. Recent study reported that Linc00152 is highly expressed in clinical IH tissues. However, the exact biological roles have not yet been investigated. The aim of the present study was to investigate the oncogenic roles of Linc00152 in IH and the underlying mechanism in vitro. Main methods The expressions of Linc00152 in IH tissues and hemangioma-derived endothelial cells (HemECs) were determined using quantitative real time-PCR (qRT-PCR) analysis. The expressions of Akt/mTOR and Notch1 pathways related proteins were detected using western blot analysis. Cell proliferation was assessed by detecting Ki67 expression and CCK-8 assay. Cell apoptosis was evaluated by detecting apoptotic rate, caspase-3/7 activity, and Bcl-2 and Bax expression. Key findings The results demonstrated Linc00152 was up-regulated in clinical IH tissues and HemECs. Knockdown of Linc00152 in HemECs suppressed the activation of Akt/mTOR and Notch1 signaling pathways and caused reduction in cell proliferation and Ki67 expression in HemECs. Besides, Linc00152 knockdown resulted in a significant increase in apoptotic rate, caspase-3/7 activity, and Bax expression level, as well as a decrease in Bcl-2 expression level. However, the effects of Linc00152 knockdown on cell proliferation and apoptosis were mitigated by overexpression of Akt or Notch1. Significance Knockdown of Linc00152 suppressed HemECs proliferation and induced apoptosis via inhibiting Akt/mTOR and Notch1 signaling pathways.
- Published
- 2019
35. Thermo-mechanical coupling analysis of the orthotropic structures by using element-free Galerkin method
- Author
-
Shusen Wang, Zhang Jianping, Hu Huiyao, Gong Shuguang, and Qing-Song Zuo
- Subjects
Materials science ,Applied Mathematics ,Isotropy ,General Engineering ,02 engineering and technology ,Mechanics ,Physics::Classical Physics ,Orthotropic material ,Computer Science::Numerical Analysis ,01 natural sciences ,Finite element method ,Thermal expansion ,010101 applied mathematics ,Stress (mechanics) ,Computational Mathematics ,020303 mechanical engineering & transports ,Thermoelastic damping ,Thermal conductivity ,0203 mechanical engineering ,0101 mathematics ,Galerkin method ,Analysis - Abstract
The computational model of thermo-mechanical coupling analysis for orthotropic structures was established based on the element-free Galerkin (EFG) method. The computational method and programs was verified through engineering thermoelastic problems of complex orthotropic structures. The influence of off-angle and the orthotropic material factors including thermal conductivity orthotropic factor, thermal expansion orthotropic factor, Poisson's ratio factor on the thermal deformation and thermal stress was investigated, and the reasonable range of these parameters was provided. A group of these preferred parameters were used to finish the thermo-mechanical coupling analysis of the orthotropic structure by using the proposed model and the results show that the maximum value of thermal deformation and thermal stress for orthotropic structure is reduced by 11% and 24% compared with the isotropic structure, respectively. The EFG solutions show a higher calculation precision than the finite element method (FEM) solutions in practical orthotropic thermoelastic problems. The off-angle affects the magnitude and direction of total thermal deformation displacement and the magnitude of Mises stress, while orthotropic materials factors only affect the magnitude of total thermal deformation displacement and the Mises stress without affecting the direction. The reasonable off-angle and orthotropic material factors can effectively improve thermal deformation and thermal stress.
- Published
- 2019
36. Non-Excludable Dynamic Mechanism Design
- Author
-
Santiago R. Balseiro, Vahab Mirrokni, Renato Paes Leme, and Song Zuo
- Published
- 2021
37. Towards Efficient Auctions in an Auto-bidding World
- Author
-
Jieming Mao, Song Zuo, Vahab Mirrokni, and Yuan Deng
- Subjects
FOS: Computer and information sciences ,Mechanism design ,business.industry ,Computer science ,media_common.quotation_subject ,05 social sciences ,TheoryofComputation_GENERAL ,Bidding ,Online advertising ,Task (project management) ,Microeconomics ,Computer Science - Computer Science and Game Theory ,0502 economics and business ,Common value auction ,Revenue ,050207 economics ,business ,Welfare ,Budget constraint ,050205 econometrics ,media_common ,Computer Science and Game Theory (cs.GT) - Abstract
Auto-bidding has become one of the main options for bidding in online advertisements, in which advertisers only need to specify high-level objectives and leave the complex task of bidding to auto-bidders. In this paper, we propose a family of auctions with boosts to improve welfare in auto-bidding environments with both return on ad spend constraints and budget constraints. Our empirical results validate our theoretical findings and show that both the welfare and revenue can be improved by selecting the weight of the boosts properly.
- Published
- 2021
- Full Text
- View/download PDF
38. Design and testing of a parabolic cam-roller quasi-zero-stiffness vibration isolator
- Author
-
Song Zuo, Dayang Wang, Yongshan Zhang, and Quantian Luo
- Subjects
0905 Civil Engineering, 0910 Manufacturing Engineering, 0913 Mechanical Engineering ,Mechanics of Materials ,Mechanical Engineering ,Mechanical Engineering & Transports ,General Materials Science ,Condensed Matter Physics ,Civil and Structural Engineering - Abstract
Circular cam-roller (CCR) quasi-zero stiffness (QZS) vibration isolators have been extensively studied. As the CCR isolator can only achieve low stiffness in a very small range and cannot withstand excitation with large amplitude, study on other cam profiles has become interests. This paper investigates a parabolic cam-roller (PCR) QZS vibration isolator. Theoretical formulations of the PCR QZS isolator are derived in detail and the condition of PCR isolator outperforming CCR one is obtained. Design parameters are analyzed and then the optimal design is presented. A prototype of the PCR QZS vibration isolator is fabricated and tested; the corresponding CCR QZS and linear isolators are also experimentally evaluated. In comparison with CCR QZS isolators, the proposed PCR QZS isolators can withstand force and displacement excitations with larger amplitudes in the QZS region. The experimental results validate the present formulation and show that vibration isolation performance of the proposed PCR QZS isolator is much better than that of the CCR QZS isolator and that of the corresponding linear isolator. In comparison with the CCR QZS isolator, the present PCR QZS isolator can have lower stiffness in a wider region around the equilibrium position and lower transmissibility.
- Published
- 2022
39. Ethanol infusion into the vein of Marshall for recurrent perimitral atrial tachycardia after catheter ablation for persistent atrial fibrillation
- Author
-
Jia-Hui Wu, Xin Zhao, Changsheng Ma, Yiwei Lai, Chen-Xi Jiang, Man Ning, Jianzeng Dong, Rong Bai, Song-Nan Li, Cai-Hua Sang, Xin Du, Wei Wang, Ri-Bo Tang, Song-Nan Wen, Xue-Yuan Guo, Nian Liu, De-Yong Long, Meng-Meng Li, and Song Zuo
- Subjects
Tachycardia ,Epicardial Mapping ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Venography ,Catheter ablation ,030204 cardiovascular system & hematology ,Coronary Angiography ,03 medical and health sciences ,0302 clinical medicine ,Recurrence ,Internal medicine ,Atrial Fibrillation ,medicine ,Tachycardia, Supraventricular ,Humans ,030212 general & internal medicine ,Vein ,Infusions, Intravenous ,Atrial tachycardia ,Aged ,medicine.diagnostic_test ,Ethanol ,business.industry ,Atrial fibrillation ,General Medicine ,Middle Aged ,Ablation ,medicine.disease ,medicine.anatomical_structure ,Persistent atrial fibrillation ,Cardiology ,Catheter Ablation ,Female ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Catheter ablation of perimitral atrial tachycardia (PMAT) is challenging. Epicardial conduction of the Marshall bundle (MB) across the mitral isthmus (MI) remains an important cause of recurrent tachycardia. The role of ethanol infusion into the vein of Marshall (EI-VOM) for PMAT has not been fully elucidated. Methods The study enrolled 28 consecutive patients with recurrent PMAT after atrial fibrillation (AF) ablation. Conventional PMAT (group 1, n = 15) and MB-related PMAT (group 2, n = 13) were diagnosed by detailed activation mapping and entrainment mapping. VOM venography and EI-VOM were first performed, and additional ablation was performed if necessary. Results The VOM was accessible in 24 (85.7%) patients (12 [80%] in group 1 and 12 [92.3%] in group 2). Patients with MB-related PMAT were more responsive to EI-VOM (as shown by PMAT termination or tachycardia cycle length prolongation) (92.4% vs 53.3%, P = .038). In the 16 patients requiring additional ablation after EI-VOM, all residual MI conduction gaps were located on the annular side of the MI. At the end of the procedure, MI bidirectional block was achieved in 14 (93.3%) patients in group 1 and in 12 (92.3%) patients in group 2 (P = 1.000). After a mean follow-up of 7.5 ± 3.1 months, three (10.7%) patients had recurrent AT. Conclusions EI-VOM is feasible and effective in the treatment of PMAT after AF ablation, especially in patients with MB-related PMAT.
- Published
- 2020
40. Curative effect of surgical resection in the treatment of Kaposiform hemangioendothelioma
- Author
-
Song Zuo, Xiaonan Guo, Yanlin Wang, Qiang Lou, and Changxian Dong
- Published
- 2020
41. Cinobufacini Inhibits Colon Cancer Invasion and Metastasis via Suppressing Wnt/β-Catenin Signaling Pathway and EMT
- Author
-
Jie Wang, Yue Xia, Han Cai, Yong Zhang, Cao Chen, Likai Xing, Ke Xu, Qiaoli Liu, Qing-Song Zuo, Teng Chen, and Peihao Yin
- Subjects
Venenum bufonis ,Epithelial-Mesenchymal Transition ,Colorectal cancer ,Wnt β catenin signaling ,Mice, Nude ,Traditional Chinese medicine ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Humans ,Neoplasm Invasiveness ,Neoplasm Metastasis ,beta Catenin ,030304 developmental biology ,Cell Proliferation ,0303 health sciences ,business.industry ,General Medicine ,medicine.disease ,HCT116 Cells ,Wnt Proteins ,Complementary and alternative medicine ,Matrix Metalloproteinase 9 ,030220 oncology & carcinogenesis ,Colonic Neoplasms ,Cancer research ,Amphibian Venoms ,Matrix Metalloproteinase 2 ,business ,Function (biology) ,Phytotherapy ,Signal Transduction - Abstract
Cinobufacini is a well-known Chinese medicine extracted from Venenum Bufonis, also called Chan Su. It has been used clinically for various cancers, including colon cancer. However, the function of Cinobufacini on colon cancer invasion and metastasis, and its underlying molecular mechanism, is still not clear. In this study, we investigated the function and mechanism of Cinobufacini on colon cancer invasion and metastasis both in vitro and in vivo studies. Human colon cancer cells were cultured. CCK assay was used to detect the effect of Cinobufacini on colon cancer cells proliferation. The invasion and migration abilities were observed by transwell assays, and the expression of invasion and migration related genes MMP2, MMP9, and epithelial-to-mesenchymal transition (EMT) relate genes were observed by Western blot assays. An orthotopic xenograft model in nude mice was established using colon cancer HCT116 cells, and the function of Cinobufacini on colon cancer invasion and metastasis were observed in vivo. We found Cinobufacini significantly inhibited colon cancer cell proliferation in a dose/time-dependent manner; the invasion and migration abilities of colon cancer were decreased after treated with Cinobufacini. The metastasis and EMT related genes MMP9, MMP2, N-cadherin and Snail were obviously down-regulated, while the expression of E-cadherin was up-regulated after treatment with Cinobufacini. The Wnt/[Formula: see text]-catenin signaling pathway related genes were observed using WB,and results show that the expression of [Formula: see text]-catenin, wnt3a, c-myc, cyclin D1, and MMP7 were all down-regulated after being treated with cinobufacini, while the expression of APC was up-regulated. In vivo studies of the volume and weight of orthotopic xenograft tumors showed significantly shrinkage in the Cinobufacini group compared to the control group. The enterocoelia and liver metastasis tumors were significantly decreased, and the expression of MMP9, MMP2, and [Formula: see text]-catenin were also down-regulated, while E-cadherin was up-regulated in vivo after the treatment with Cinobufacini. Our data proves that Cinobufacini can inhibit colon cancer invasion and metastasis both in vitro and in vivo; the mechanism is related by suppressing the Wnt/[Formula: see text]-catenin signaling pathway and then inhibiting the EMT of CRC.
- Published
- 2020
42. A Data-Driven Metric of Incentive Compatibility
- Author
-
Sébastien Lahaie, Song Zuo, Vahab Mirrokni, and Yuan Deng
- Subjects
TheoryofComputation_MISCELLANEOUS ,Mathematical optimization ,Computer science ,business.industry ,Display advertising ,TheoryofComputation_GENERAL ,02 engineering and technology ,Data-driven ,Incentive compatibility ,020204 information systems ,Search advertising ,Metric (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,Common value auction ,020201 artificial intelligence & image processing ,business ,Valuation (finance) - Abstract
An incentive-compatible auction incentivizes buyers to truthfully reveal their private valuations. However, many ad auction mechanisms deployed in practice are not incentive-compatible, such as first-price auctions (for display advertising) and the generalized second-price auction (for search advertising). We introduce a new metric to quantify incentive compatibility in both static and dynamic environments. Our metric is data-driven and can be computed directly through black-box auction simulations without relying on reference mechanisms or complex optimizations. We provide interpretable characterizations of our metric and prove that it is monotone in auction parameters for several mechanisms used in practice, such as soft floors and dynamic reserve prices. We empirically evaluate our metric on ad auction data from a major ad exchange and a major search engine to demonstrate its broad applicability in practice.
- Published
- 2020
43. Effectiveness and safety of atrial fibrillation ablation in females
- Author
-
Changsheng Ma, Rong-Hui Yu, Jianzeng Dong, Shijun Xia, Xin Du, Laurent Macle, San-Shuai Chang, Jingye Li, Ri-Bo Tang, Shangxin Lu, Xue-Yuan Guo, Cai-Hua Sang, De-Yong Long, Nian Liu, Song Zuo, Rong Bai, Liu He, Chen-Xi Jiang, Song-Nan Li, and Chao Jiang
- Subjects
Male ,medicine.medical_specialty ,Multivariate analysis ,medicine.medical_treatment ,Catheter ablation ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Sex Factors ,Internal medicine ,Hyperlipidemia ,Atrial Fibrillation ,medicine ,Humans ,030212 general & internal medicine ,Prospective Studies ,Risk factor ,Cardiac Surgical Procedures ,Aged ,business.industry ,Incidence (epidemiology) ,Confounding ,Atrial fibrillation ,General Medicine ,Middle Aged ,Ablation ,medicine.disease ,Treatment Outcome ,Cardiology ,Catheter Ablation ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
BACKGROUND Existing data on the effectiveness and safety of atrial fibrillation (AF) ablation in females are limited to studies of small sample size, lacking longer term follow-up or adjustment for potential confounders. METHODS A total of 6421 patients (2072 females) undergoing a first AF ablation procedure after enrollment in the Chinese Atrial Fibrillation Registry (China-AF) study between August 2011 and December 2017 were analyzed. We evaluated the effectiveness (recurrence of documented [symptomatic or not] atrial tachyarrhythmia (AT)) and the safety (incidence of procedure-related complications) of AF ablation in female patients compared to male patients. Sensitivity analyses based on routine data were also utilized to avoid potential sex differences in reporting of AF symptoms. RESULTS Females were about 5 years older than males at the time of ablation (mean age 63.4 ± 9.5 vs 58.3 ± 10.8, P
- Published
- 2020
44. Pravastatin alleviates intracellular calcium dysregulation induced by Interleukin-6 via the mitochondrial ROS pathway in adult ventricular myocytes
- Author
-
Yanfei Ruan, Jianzeng Dong, Chao Jiang, Linling Li, Nian Liu, Le Jiang, Rong Bai, Xin Li, Song Zuo, Song-Nan Li, Xin Du, Song-Nan Wen, and Changsheng Ma
- Subjects
0301 basic medicine ,Mitochondrial ROS ,Male ,Cardiotonic Agents ,Heart Ventricles ,chemistry.chemical_element ,Inflammation ,Calcium ,Pharmacology ,Calcium in biology ,03 medical and health sciences ,Mice ,0302 clinical medicine ,medicine ,Animals ,Myocytes, Cardiac ,Calcium handling ,Acute inflammation ,Cells, Cultured ,Pravastatin ,Chemistry ,Interleukin-6 ,lcsh:RM1-950 ,Calcium sparks ,Mitochondria ,Mice, Inbred C57BL ,Cytosol ,Sarcoplasmic Reticulum ,lcsh:Therapeutics. Pharmacology ,030104 developmental biology ,Molecular Medicine ,medicine.symptom ,Calcium disorder ,Cardiomyopathies ,Reactive Oxygen Species ,030217 neurology & neurosurgery ,medicine.drug ,Signal Transduction - Abstract
Acute inflammation often contributes to the increased arrhythmogenesis in the cardiomyocytes. We investigated the protective effects of pravastatin on calcium disorders induced by acute administration of pro-inflammatory cytokines in isolated ventricular myocytes and its underlying mechanisms. Wild-type mice were intraperitoneally injected for five days with either pravastatin 20 mg/kg per day or an equal volume of normal saline. Cytosol Ca2+ handling was studied in freshly isolated ventricular myocytes after acute exposure of interleukin-6 (IL-6) (1 ng/ml) for 120 min by Ionoptix and confocal microscopy. Acute administration of clinically relevant concentrations of IL-6 disturbed calcium handling in ventricular myocytes, which presented as decreased amplitudes, prolonged decay times of Ca2+ transients, and reduced sarcoplasmic reticulum (SR) calcium stores. The frequency of spontaneous Ca2+ release, including calcium sparks and spontaneous calcium waves, was dramatically enhanced in the setting of IL-6. Notably, the pretreatment of pravastatin alleviated disturbed Ca2+ cycling, reduced spontaneous Ca2+ leakage induced by IL-6. Mitochondrial ROS pathway may constitute the underlying mechanism of the protective effects of pravastatin. Pravastatin protected the cardiomyocytes against calcium disorders induced by IL-6 via the mitochondrial ROS pathway, which suggests that pravastatin may represent a promising auxiliary therapeutic strategy for cardiac injury under acute inflammation.
- Published
- 2019
45. An improved method of immersion vacuum cooling for small cooked pork: Bubbling Vacuum Cooling
- Author
-
Xiao-yan Song, Song Zuo, Guo Zhiyu, and Baolin Liu
- Subjects
0404 agricultural biotechnology ,Materials science ,Water temperature ,Immersion (virtual reality) ,Vacuum cooling ,Improved method ,04 agricultural and veterinary sciences ,Texture (crystalline) ,Composite material ,040401 food science ,Industrial and Manufacturing Engineering ,Cooling time ,Food Science - Published
- 2018
46. Surgical treatment of kaposiform hemangioendothelioma in the pelvic cavity, bladder and ureter
- Author
-
Changxian Dong, Yanlin Wang, Song Zuo, and Li Xiao
- Subjects
Tufted angioma ,medicine.medical_specialty ,business.industry ,lcsh:RJ1-570 ,lcsh:Surgery ,lcsh:Pediatrics ,lcsh:RD1-811 ,Hypofibrinogenemia ,Pelvic cavity ,medicine.disease ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,Ureter ,medicine.anatomical_structure ,Vascular Tumors ,Kaposiform Hemangioendothelioma ,030225 pediatrics ,030220 oncology & carcinogenesis ,Consumptive Coagulopathy ,Pediatrics, Perinatology and Child Health ,medicine ,Surgical treatment ,business - Abstract
Kasabach-Merritt phenomenon (KMP) is a rare potentially life-threatening consumptive coagulopathy characterized by thrombocytopenia and hypofibrinogenemia occurring associated with the vascular tumors kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). KHE in the specific sites will also cause some non-hemorrhagic complications. We report a two-month old female infant with KHE in her pelvic cavity, bladder and ureter who responded well to surgical excision. Keywords: Kaposiform hemangioendothelioma, Kasabach-Merritt phenomenon, Pelviccavity, Bladder, Ureter, Surgical excision, Thrombocytopenia, Coagulopathy, Therapy
- Published
- 2018
47. B-AB21-04 EFFECTIVENESS OF ETHANOL INFUSION INTO THE VEIN OF MARSHALL COMBINED WITH A FIXED ANATOMICAL ABLATION STRATEGY (THE ‘UPGRADED 2C3L’ APPROACH) FOR CATHETER ABLATION OF PERSISTENT ATRIAL FIBRILLATION
- Author
-
Cai-Hua Sang, Changsheng Ma, Yiwei Lai, Jian-Zeng Dong, Guo Qi, and Song Zuo
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Catheter ablation ,Ablation ,medicine.anatomical_structure ,Physiology (medical) ,Internal medicine ,Persistent atrial fibrillation ,medicine ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Vein - Published
- 2021
48. Acute administration of tumour necrosis factor-α induces spontaneous calcium release via the reactive oxygen species pathway in atrial myocytes
- Author
-
Song-Nan Li, Jian-Zeng Dong, Song-Nan Wen, Changsheng Ma, Le Jiang, Yanfei Ruan, Rong Bai, Xin Li, Song Zuo, Xin Du, Linling Li, and Nian Liu
- Subjects
Male ,0301 basic medicine ,Mitochondrial ROS ,medicine.medical_specialty ,Time Factors ,Necrosis ,Action Potentials ,chemistry.chemical_element ,030204 cardiovascular system & hematology ,Calcium ,Pharmacology ,Ryanodine receptor 2 ,Mitochondria, Heart ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,Internal medicine ,Ca2+/calmodulin-dependent protein kinase ,Animals ,Medicine ,Myocytes, Cardiac ,Calcium Signaling ,Heart Atria ,Phosphorylation ,Heart metabolism ,Inflammation ,chemistry.chemical_classification ,Reactive oxygen species ,Tumor Necrosis Factor-alpha ,business.industry ,Arrhythmias, Cardiac ,Ryanodine Receptor Calcium Release Channel ,Mice, Inbred C57BL ,Oxidative Stress ,Sarcoplasmic Reticulum ,030104 developmental biology ,chemistry ,Cardiology ,Tumor necrosis factor alpha ,medicine.symptom ,Calcium-Calmodulin-Dependent Protein Kinase Type 2 ,Reactive Oxygen Species ,Cardiology and Cardiovascular Medicine ,business - Abstract
Aims The arrhythmogenic mechanisms of atrial fibrillation (AF) that are induced by acute inflammation, such as postoperative AF, are not well understood. We investigated the acute effects of tumour necrosis factor-α (TNF-α) that mimic acute inflammation on Ca2+ handling in isolated atrial myocytes and its underlying mechanisms. Methods and results Cytosol Ca2+ handling and mitochondrial reactive oxygen species (ROS) production were studied in freshly isolated atrial myocytes of wild-type mice that were exposed to TNF-α (0.05 ng/mL) for 2 h by Ionoptix and confocal microscopy. The acute effects of TNF-α on Ca2+ handling were decreased amplitudes and prolonged decay times of Ca2+ transients in isolated atrial myocytes. A significant reduction in the sarcoplasmic reticulum (SR) Ca2+ content was detected in TNF-α treated cells, which was associated with increased spontaneous Ca2+ release events. In particular, physiological concentrations of TNF-α dramatically promoted the frequency of spontaneous Ca2+ waves and Ca2+ sparks, while the spark mass presented with reduced amplitudes and prolonged durations. The underlying mechanisms of pro-arrhythmic effects of TNF-α were further investigated. Acute exposure to TNF-α rapidly promoted mitochondrial ROS production that was correlated with the acute effect of TNF-α on Ca2+ handling, and enhanced the oxidation of calcium/calmodulin-dependent protein kinase II (CaMKII) and the phosphorylation of RyR2. However, the performance of ROS inhibitor, DL-Dithiothreitol (DTT), reversed Ca2+ handling disorders induced by TNF-α. Conclusion Tumour necrosis factor-α rapidly increases spontaneous Ca2+ release and promotes atrial arrhythmogenesis via the ROS pathway, which suggests that antioxidant therapy is a promising strategy for acute inflammation related AF.
- Published
- 2017
49. Left-sided accessory pathways successfully ablated from the aortomitral continuity region: distinctive atrial activation patterns and anatomic concerns
- Author
-
Chen-Xi Jiang, Xin Du, Xiang-Yi Kong, Cai-Hua Sang, Song-Nan Li, Ri-Bo Tang, Wei Wang, Jianzeng Dong, Man Ning, De-Yong Long, Xue-Yuan Guo, Song Zuo, Changsheng Ma, Xu Li, Wen-Li Dai, Jia-Hui Wu, Xin Zhao, Meng-Meng Li, and Jingye Li
- Subjects
Tachycardia ,Adult ,Male ,medicine.medical_treatment ,Catheter ablation ,Accessory pathway ,Bundle of His ,QRS complex ,Electrocardiography ,Physiology (medical) ,medicine ,Humans ,Heart Atria ,Atrium (heart) ,Coronary sinus ,business.industry ,Middle Aged ,Ablation ,Accessory Atrioventricular Bundle ,medicine.anatomical_structure ,Catheter Ablation ,Female ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Nuclear medicine - Abstract
Aims Accessory pathways (APs) successfully ablated at the aortomitral continuity (AMC) were sporadically reported but relevant data are very limited. We aimed to describe the electrophysiological characteristics of AMC-AP and the related anatomy. Methods and results This study involved eight (male/female = 3/5, mean age 42.6 ± 10.5 years) patients with left-sided AP successfully ablated in the AMC region. The retrograde atrial activation sequence was analysed and compared via recordings at the His-bundle (HB), coronary sinus (CS), and roving catheter during tachycardia, and the peak of QRS from the same cardiac circle used as time reference. Of the eight patients, two received prior ablations. During tachycardia, the activation time at the proximal CS (CSp), lateral CS (CSl), and HB region averaged 120 ± 26 ms, 124 ± 29 ms, and 117 ± 21 ms following the reference, respectively (P = 0.86). The latest atrial activation was recorded in the posterior CS which averaged 135 ± 25 ms following the reference. Placing the ablation catheter to AMC via retrograde approach was attempted in all cases but stable positioning achieved in none. Via transseptal approach, the ablation catheter could be easily placed at the AMC and recorded the earliest retrograde atrial activations with 60 ± 27 ms earlier than the relatively ‘earliest’ CS/HB recordings, and ablation at this site successfully eliminated AP conduction. No patients had recovered AP conduction after at least 12-month follow-up. Conclusion AMC-AP is featured by recording comparable retrograde atrial activation times at CSp, CSl, and HB with the latest recordings at the posterior CS. Stable placement and successful ablation in the AMC via retrograde aortic approach was difficult but can be achieved via transseptal approach.
- Published
- 2019
50. Dispatching Through Pricing: Modeling Ride-Sharing and Designing Dynamic Prices
- Author
-
Weiran Shen, Song Zuo, Pingzhong Tang, and Mengjing Chen
- Subjects
Computer science - Abstract
Over the past few years, ride-sharing has emerged as an effective way to relieve traffic congestion. A key problem for the ride-sharing platforms is to come up with a revenue-optimal (or GMV-optimal) pricing scheme and a vehicle dispatching policy that incorporate geographic and temporal information. In this paper, we aim to tackle this problem via an economic approach. Modeled naively, the underlying optimization problem may be non-convex and thus hard to solve. To this end, we use a so-called ``ironing'' technique to convert the problem into an equivalent convex optimization one via a clean Markov decision process (MDP) formulation, where the states are the driver distributions and the decision variables are the prices for each pair of locations. Our main finding is an efficient algorithm that computes the exact revenue-optimal (or GMV-optimal) randomized pricing scheme, which naturally induces the accompany vehicle dispatching policy. We also conduct empirical evaluations of our solution through real data of a major ride-sharing platform and show its advantages over fixed pricing schemes as well as several prevalent surge-based pricing schemes.
- Published
- 2019
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.