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Deep Reinforcement Learning for Active Flow Control around a Circular Cylinder Using...
Mohamed Elhawary

Mohamed Elhawary

December 28, 2020
Deep reinforcement learning (DRL) algorithms are rapidly making inroads into fluid mechanics, following the remarkable achievements of these techniques in a wide range of science and engineering applications. In this paper, a deep reinforcement learning (DRL) agent has been employed to train an artificial neural network (ANN) using computational fluid dynamics (CFD) data to perform active flow control (AFC) around a 2-D circular cylinder. Flow control strategies are investigated at a diameter-based Reynolds number Re_D = 100 using advantage actor-critic (A2C) algorithm by means of two symmetric plasma actuators located on the surface of the cylinder near the separation point. The DRL agent interacts with the computational fluid dynamics (CFD) environment through manipulating the non-dimensional burst frequency (f+) of the two plasma actuators, and the time-averaged surface pressure is used as a feedback observation to the deep neural networks (DNNs). The results show that a regular actuation using a constant non-dimensional burst frequency gives a maximum drag reduction of 21.8 %, while the DRL agent is able to learn a control strategy that achieves a drag reduction of 22.6%. By analyzing the flow-field, it is shown that the drag reduction is accompanied with a strong flow reattachment and a significant reduction in the mean velocity magnitude and velocity fluctuations at the wake region. These outcomes prove the great capabilities of the deep reinforcement learning (DRL) paradigm in performing active flow control (AFC), and pave the way toward developing robust flow control strategies for real-life applications.
Combination chemotherapy consisting of irinotecan, etoposide, and carboplatin (IREC)...
Masayuki Imaya
Hideki Muramatsu

Masayuki Imaya

and 14 more

December 28, 2020
Background: Patients with relapsed or refractory neuroblastoma have a poor prognosis; there are limited effective and safe rescue chemotherapies for these patients. Development of new chemotherapy regimens for these patients is a key imperative. Procedure: We retrospectively analyzed patients with refractory or relapsed neuroblastoma who received irinotecan, etoposide, and carboplatin (IREC) as a second-line treatment for neuroblastoma. We evaluated the therapeutic response, toxicity, and survival outcomes. We also assessed the impact of UGT1A1 gene polymorphisms, which are involved in irinotecan metabolism, on the outcomes and toxicity. Results: A total of 131 cycles of IREC were administered to 43 patients with a median of two cycles per patient (range, 1–10). All patients were classified as high-risk (International Neuroblastoma Risk Group). Seven patients had relapsed before IREC. One patient (2%) showed partial response and 37 patients (86%) developed stable disease (disease control rate: 88%). Grade IV neutropenia was observed in 127 cycles (97%), while ≥ grade III gastrointestinal toxicity was observed in 3 cycles (2%). There was no IREC-related mortality. The one-year overall survival and progression-free survival rates were 65% and 52%, respectively. Patients with UGT1A1 polymorphisms showed a higher frequency of grade IV neutropenia; however, there was no increase in treatment-related mortality or nonhematological toxicity in these patients. Patients with UGT1A1 gene polymorphisms showed better one-year survival rate than the wild type (80% vs. 44%, p = 0.012). Conclusions: This study suggests that IREC is well-tolerated by patients with UGT1A1 polymorphisms and is a promising second-line chemotherapy for refractory/relapsed neuroblastoma.
Development and internal validation of a model predicting severe maternal morbidity u...
Natalie Dayan
Gabriel Shapirio

Natalie Dayan

and 8 more

December 27, 2020
Objective: To improve the prediction of maternal end-organ injury or death using routinely-collected variables from the pre-pregnancy and the early pregnancy period. Design: Population-based cohort study using linked administrative health data. Setting: Ontario, Canada, April 1, 2006 to March 31, 2014. Sample: Women aged 18-60 years with a livebirth or stillbirth, of which one birth was randomly selected per woman. Methods and main outcome measures: We constructed a CPM for the primary composite outcome of any maternal end-organ injury or death, arising between 20 weeks’ gestation and 42 days after the birth hospital discharge date. Our CPM included variables collected from 12 months before estimated conception until 19 weeks’ gestation. We developed a separate CPM for parous women to allow for the inclusion of factors from previous pregnancy(ies). Results: Of 634,290 women, 1969 experienced the primary composite outcome (3.1 per 1000). Predictive factors in the main CPM included maternal world region of origin, chronic medical conditions, parity, and obstetrical/perinatal issues – with moderate model discrimination (C-statistic 0.68, 95% CI 0.66-0.69). Among 333,435 parous women, the C-statistic was 0.71 (0.69-0.73) in the model using variables from the current (index) pregnancy as well as pre-pregnancy predictors and variables from any previous pregnancy. Conclusions: A combination of factors ascertained early in pregnancy through a basic medical history help to identify women at risk for severe morbidity, who may benefit from targeted preventive and surveillance strategies including appropriate specialty-based antenatal care pathways. Further refinement of this model would enable clinical use.
Safety and Efficacy of Cryoballoon versus Radiofrequency Ablation for Atrial Fibrilla...
Tauseef Akhtar
Usama Daimee

Tauseef Akhtar

and 8 more

December 27, 2020
Introduction: There are limited data describing the experience of index radiofrequency (RF) vs. cryoballoon (CB) ablation for atrial fibrillation (AF) among elderly patients in the United States. Methods: We conducted a retrospective analysis of patients > 75 years of age undergoing index AF ablation between January 2010 and March 2019 at our center. Major complications and efficacy, defined as freedom from any atrial tachyarrhythmia (ATA) lasting ≥30 seconds after one year of follow-up, were assessed in patients with index RF vs. CB ablation. Predictors of ATA recurrence at 1 year follow-up were also evaluated. Results: In our cohort of 194 patients, the mean age was 78 ± 3.1 years, 58.2% were men, and 39.4% had persistent AF. The mean left atrial (LA) diameter was 4.5 ± 0.7, while the mean CHA2DS2-VASc score was 3.5 ± 1.2. The majority (n=149, 76.8%) underwent RF ablation. The incidence of complications was similar in the two sub-groups (RF: 1.3% vs. CB: 2.2%, p=0.67). No significant difference in success rate at 1-year follow-up was found between patients receiving RF vs. CB ablation (59.7% vs. 66.7%, p=0.68). In a multivariable model adjusting for the relevant covariates only LA size [HR=1.64, CI: 1.15-2.34, p<0.01] was independently associated with ATA recurrence at 1year follow-up. Conclusion: In our cohort of elderly patients undergoing index CA for AF, RF ablation was the predominant modality with similar safety and efficacy relative to CB ablation. LA size was a significant predictor of ATA recurrence at 1year independent of index ablation modality.
Measurement of Patient Confidence in Self-Management of Atrial Fibrillation: Initial...
Connor Tripp
Anil Gehi

Connor Tripp

and 4 more

December 27, 2020
Abstract Background: The patient experience of atrial fibrillation (AF) involves several daily self-care behaviors and ongoing confidence to manage their condition. Currently, no standardized self-report measure of AF patient confidence exists. The purpose of this study is to establish the reliability and validity of a newly developed confidence in AF management measure. Methods: This study provides preliminary analysis of the Confidence in Atrial FibriLlation Management (CALM) scale, which was rationally developed to measure patient confidence related to self-management of AF. The scale was provided to a sample of AF patients N=120, (59% male) electronically through a patient education platform. Principle components analysis (PCA) and Cronbach’s alpha were employed to provide preliminary assessment of the validity and reliability of the measure. Results: PCA identified a four-factor solution. Internal consistency of the CALM was considered excellent with Cronbach’s α = .910. Additional PCA confirmed the value of a single factor solution to produce a total confidence score for improved utility and ease of clinical interpretation. Conclusions: Initial assessment of a novel scale measuring patient confidence in managing AF provided promising reliability and validity. Patient confidence in self-management of AF may prove useful as a key marker and endpoint of the patient experience beyond QOL.
Suspension Laryngoscopy Experiences in a Tertiary Airway Service: a Prospective Study...
Elizabeth Maughan
Anthony Rotman

Elizabeth Maughan

and 7 more

December 27, 2020
Abstract Objectives: In most cases, suspension laryngoscopy (SL) is efficient, bloodless and with minimal post-procedure discomfort. We aimed to identify predictive patient factors for acceptable surgical views at SL as well as quantify our tertiary airway unit’s complication rates. Design: Prospective cohort study of 150 consecutive microlaryngoscopy procedures involving SL over an 8-month period between November 2019 and July 2020. Patients were assessed pre-operatively for pre-existing oral, temporomandibular, dental, pharyngeal or laryngeal pathology, interincisor distance and qualitative gross limitations to neck extension and forward head posture. Intraoperatively, the laryngoscopic view was graded by anesthetic and surgical teams, and complications were recorded on patient interview in recovery. Setting: Tertiary adult airway service for predominantly benign pathology. Results: Adequate surgical views were obtained in 149/150 procedures. BMI and limitations to chin and neck movement had mild positive correlations with more difficult views in their own rights, but did not correlate with a statistically significant increase in complications. There was a negative correlation between age and interincisor gap (p=0.014), and wider mouth opening correlated with a lower incidence of sore throat (p=0.023). Macroglossia showed a statistically significant positive correlation with tongue symptoms (p=1.611x10-8). Conclusion: In the context of an experienced airway unit with a high caseload of predominantly benign pathology, SL is very effective and safe with low associated morbidity and no mortality. Patient-reported neck and chin movement were found to correlate well with the surgical view obtained. The most common complication of SL is temporary sore throat and there remain recognized risks of temporary tongue and dental symptoms.
Totally Endoscopic Septal Myectomy in a Patient with Aortic Prothesis and Complicated...
Huimin Cui
Lin Zhang

Huimin Cui

and 3 more

December 27, 2020
Abstract The Morrow procedure which uses a median sternotomy with the left ventricle and septum accessed by the aortic valve through a vertical aortotomy is the current standard procedure for left ventricular outflow tract obstruction in hypertrophic cardiomyopathy. However, this approach may be limited in patients who have previously undergone aortic valve replacement. Here, we present a patient who complicated with lymphoma underwent endoscopic septal myectomy to preserve the previously implanted aortic prosthesis. Keywords: Endoscopic surgery, hypertrophic cardiomyopathy, septal myectomy.
Evaluation of dyspnea severity and sleep quality in patients with novel coronavirus
SERAP Güngör
Betul Tosun

SERAP Güngör

and 3 more

December 27, 2020
Aim: Dyspnea, a common symptom of novel coronavirus, can negatively affect sleep quality. The aim of this study was to evaluate the relationship between dyspnea severity and sleep quality in patients with COVID-19. Study Design: A cross-sectional design was used. Methods: Using the researcher’s mobile phone, data were collected via an online questionnaire from patients (n=100) who agreed to participate in the study. The data-collection form comprised three parts: a patient descriptive information form, the Dyspnea–12 Questionnaire, and the Richards–Campbell Sleep Questionnaire. Results: The mean age of patients was 46.39±12.61 years and 66.0% were male. Patients who were treated in the intensive care unit, had bachelor’s degree or more and patients with comorbid diseases had low mean scores from the RCSQ and high mean scores from the Dyspnea–12 Questionnaire (p<0.001, p<0.001; p=0.047, p<0.001;p<0.001, p<0.00,1,respectively).Patients who not receiving oxygen therapy had higher RCSQ mean scores and lower Dyspnea–12 Questionnaire scores (p<0.001, p<0.001; p<0.001, p<0.001, respectively). There was a strong negative relationship between the total scores obtained from the Richards–Campbell Sleep Questionnaire and the Dyspnea–12 Questionnaire(r= -701, p<.001). Conclusions: Sleep quality is affected by dyspnea severity in patients with COVID-19. Sleep quality and dyspnea severity are also influenced by quite different factors, and these should be addressed and eliminated by nurses as part of a holistic approach. The results of this study will help nurses, especially those providing treatment and care for patients with COVID-19, to identify the factors affecting dyspnea and sleep quality and to plan, implement, and evaluate nursing interventions that will reduce their workload.
Modeling the Influence of the Composition of Refractory Elements on the Heat Resistan...
Dmitry TARASOV
Oleg Milder

Dmitry TARASOV

and 2 more

December 27, 2020
Nickel alloys are widely used in the production of gas turbine parts. The alloys show resistance to mechanical and chemical degradation under severe long-term stress and high temperatures. One of the major mechanical properties of the alloys is the high-temperature rupture strength, which is measured after a specimen is heated to a certain temperature and held for a certain time considering deformation. Determining the influence of certain elements on the properties of an alloy is a complex scientific and engineering problem that affects the time and cost of developing new materials. Simulation is a great chance to cut costs. In this paper, we predict a high-temperature strength based on the composition of refractory elements in alloys using a deep learning artificial neural network. We build the model based on prior knowledge of the composition of the alloys, information on the role of alloying elements, type of crystallization, test temperature and time, and the tensile strength. Successful simulation results show the applicability of this method in practice.
Oral paclitaxel with encequidar compared to intravenous paclitaxel in patients with a...
Christopher Jackson
Tak Hung

Christopher Jackson

and 17 more

January 04, 2021
Background and purpose: Paclitaxel is a widely used anti-neoplastic agent but has low oral bioavailability due to gut extrusion by P-glycoprotein (P-gp). Oral paclitaxel could be more convenient, less resource intensive, and more tolerable than intravenous administration. Encequidar (HM30181A) is a novel, minimally absorbed gut specific P-gp inhibitor. We tested whether administration of oral paclitaxel with encequidar (oPac+E) achieved comparable AUC to intravenous paclitaxel (IVP) 80mg/m2. Experimental approach: We conducted a multi-centre randomised crossover study with two treatment periods. Patients (pts) with advanced cancer received either oral paclitaxel 615mg/m2 divided over three days and encequidar 15mg orally one-hour prior, followed by IVP 80mg/m2, or the reverse sequence. PK blood samples were taken up to day 9 for oPac+E and day 5 for IVP. Key Results: 42 pts were enrolled; 35 completed both treatment periods. AUC0-∞was 5033.5 +/- 1401.1 ng.h/mL for oPac+E and 5595.9 +/- 1264.1 ng.h/mL with IVP. The geometric mean ratio (GMR) for AUC was 89.5% (90% CI 83.9-95.5). Mean absolute bioavailability of oPac+E was 12%. PK parameters did not change meaningfully after 4 weeks administration of oPac+E in an extension study. G3 treatment emergent adverse events occurred in 7 (18%) pts with oPac+E and 2 (5%) with IVP. 75% of pts preferred oPac+E over IVP. Conclusion and Implications: GMR for AUC was within the predefined acceptable range of 80%-125% for demonstrating equivalence. oPac+E is tolerable and there is no evidence of P-gp induction with repeat administration. With further study, oPac+E is a candidate to replace IVP.
Effect of Endoscopic Versus Open Saphenous Vein Harvesting Technique on Leg Wound Com...
Yasser Mubarak

Yasser Mubarak

December 27, 2020
Background: EVH has become prevalent in recent years due to its reduced morbidity and increased patient satisfaction. We designed and carried out a prospective study of patients undergoing CABG to compare outcomes of open versus endoscopic harvesting technique for great saphenous vein. Two groups of patients who underwent elective Coronary artery bypass grafting at our hospitals between January 2018 and October 2020 were included. Endoscopic vein harvesting group (50 patients) was performed endoscopic technique compared with Open Vein Harvesting group (50 patients) was performed open surgical incision for harvesting. Both groups were demographically similar and received identical management. Leg wound was evaluated at discharge, 2 weeks, and 4 weeks for evidence of complications. Early outcomes were compared included, infection, gaped wound and re-suture, pain, satisfied cosmetically and mobilization. Results: Endoscopic vein harvesting group had increased harvest time and decreased incision closure time when compared with Open Vein Harvesting. The average hospitalization time was 6.5 ± 2.2 days for Endoscopic vein harvesting group and 9.2 ± 2.9 days for Open Vein Harvesting group. In Endoscopic vein harvesting group, no significant hematomas were observed. In Open Vein Harvesting group, hematomas were detected in 2 patients and were surgically evacuated. In Endoscopic vein harvesting group, edema occurred less frequently. Infection of the incision location did not occur in Endoscopic vein harvesting group. Leg wound complications were significantly reduced in Endoscopic vein harvesting group in comparison with Open Vein Harvesting group. Conclusions: Endoscopic vein harvesting decreases leg wound complications and increases patient’s satisfaction cosmetically.
RR interval variability in the evaluation of ventricular tachycardia and effects of i...
Keita Tsukahara
Yasushi Oginosawa

Keita Tsukahara

and 22 more

December 27, 2020
Introduction: An implantable cardioverter defibrillator (ICD) is the most reliable therapeutic device for preventing sudden cardiac death in patients with sustained ventricular tachycardia (VT). Regarding the effectiveness of the ICD, targeted VT is defined based on the tachyarrhythmia cycle length. However, variation of the RR interval variability of VTs does occur. A few studies reported on VT characteristics and effects of ICD therapy according to RR interval variability. This study aimed to identify the clinical characteristics of VTs and effects of ICD therapy according to RR interval variability. Methods: We analyzed 821 VT episodes in 69 of 185 patients treated with ICDs or cardiac resynchronization therapy defibrillators. VTs were classified as regular or irregular based on RR interval variability. We evaluated successful termination using anti-tachycardia pacing (ATP)/shock therapy, spontaneous termination, and acceleration between regular and irregular VTs. Reproducibility of the RR interval variability in one VT episode and within an individual with recurrent VT episodes was evaluated. Results: Regular VT was significantly more successfully terminated than irregular VT by ATP therapy. There was no significant difference in shock therapy or VT acceleration, irrespective of the variability of the VT cycle length. Spontaneous termination of VT occurred significantly more often in irregular than in regular VT. Reproducibility of RR interval variability in an episode and individual was 89% and 73%, respectively. Conclusion: ATP therapy showed greater effectiveness for regular than for irregular VT. Spontaneous termination was more common in irregular than in regular VT. RR interval variability of VTs is reproducible.
Magnetoconvection in a Bidispersive Porous Media
GUNDLAPALLY SHIVA REDDY
Ragoju Ravi

GUNDLAPALLY SHIVA REDDY

and 1 more

December 27, 2020
Thermal instability of magnetoconvection in a horizontal bidispersive porous layer, uniformly heated from below, is analyzed. To study the linear stability theory, we perturbed the basic state with small-amplitude disturbances. Then, the governing dimensionless equations are solved using the normal modes. By employing the one-term Galerkin weighted residuals method, the critical values of Rayleigh numbers for the onset of stationary and oscillatory instability, have been determined. The effect of Chandrasekhar number on the system was analyzed.
Electrical Conductivity Inversion Method of Saline Soil based on Sentinel-2 MSI data
Yishan Sun
Xiaojie Li

Yishan Sun

and 4 more

December 27, 2020
Electrical conductivity (EC) is not only an important index to evaluate the degree of soil salinization, but also an essential basis for judging whether saline soil can be improved and assess the effect of improvement efforts. Satellite remote sensing provides much information for large scale EC inversion of saline soil, which enables the possibility for evaluating the degree and distribution of soil salinization. Taking the salinized region of western Jilin Province as the study area, 328 salinized soil samples were collected, and the EC was measured in June 2019. The construction of the optimal spectral parameters was based on the correlation between the conductivity and the spectral reflectivity of Sentinel-2 MSI data; after satisfying the normal distribution for the Box-Cox transformation of EC, the inversion model of EC was established by using linear regression model, support vector machine (SVM), regression tree (RT), Gaussian process regression (GPR), and ensemble tree (ET). The verification results of the model on the validation set showed that the performance of GPR was optimal (R2 = 0.66, RMSE = 0.48 mS/cm, MAE=0.52 mS/cm), which increased R2 by 29.04% compared with the traditional linear regression model. Finally, according to the GPR model, the EC results of pixel-level resolution (10 m × 10 m) of saline soil in western Jilin Province were inversed, which provided a scientific basis for the study of the distribution characteristics and improvement scheme of saline soil.
A GEO-SPATIAL APPROACH TO ASSESS TREE OUTSIDE FORESTS (TOF) IN HARYANA STATE, INDIA
K.E. Kumar
Ritesh Kumar

K.E. Kumar

and 16 more

December 27, 2020
Mapping and monitoring the Trees outside Forests (ToF) is gaining significance in the scientific community as they provide critical ecosystem services such as protecting soil and water resources, wildlife habitat, energy efficiency etc. Also, quantifying ToF can provide useful information on emissions estimation in the Agriculture, Forests, and Other Land Use (AFOLU) category of the Intergovernmental Panel for Climate Change (IPCC). Despite the importance of quantifying ToF, very few studies have attempted to quantify them in India’s natural resource inventory programs. In this study, we focus on Haryana state, India, to map ToF using very high-resolution (VHR) Indian Remote Sensing (IRS) satellite data. Haryana’s landscape is highly interspersed with croplands and ToF, thus providing a challenging environment to test VHR satellite data’s ability to quantify the diversified landscape structure. We specifically used Cartosat-1 panchromatic (2.5m) and Multispectral LISS IV (5.8m) datasets to quantify the vegetation and build a much-needed database on ToF. We used a novel classification scheme based on the geometry, i.e., point, polygon, or polygon formations, to quantify ToF at 1:10,000 scale. Our results suggest ToF with the point, area, and linear block formations of about 2,774,531, 20.51, and 128.83 sq. km, respectively, accounting for ~3.38% of the total study area . Our study highlights the usefulness of VHR satellite data and fused imagery to quantify ToF in highly diverse landscapes, with the case study in Haryana State, India. The results will help address vital ecosystem services from ToF, including greenhouse gas emissions quantification from the AFOLU category.
Effects of planting Melia azedarach L. on soil properties and microbial community in...
Na  Li
Tianyun  Shao

Na Li

and 8 more

December 27, 2020
Saline-alkali soils are widely distributed in China, affecting plant growth and sustainable development of ecosystems. This study characterized the effects of planting Melia azedarach L. on chemical properties and microbial communities in saline-alkali soils [bare (CK), bulk (BS) and rhizosphere soil (RS)]. Compared with the bare soil, planting Melia azedarach L. lowered salt content and concentrations of extractable Na, K, Ca, Mg and Cl-, but significantly increased organic matter, total nitrogen, total phosphorus, available phosphorus, soil urease activity and alkaline phosphatase activity in the rhizosphere soil. High-throughput sequencing results indicated that bacterial richness and diversity decreased in the order RS>BS>CK. The richness of fungi was ranked RS>CK>BS, and their diversity decreased in the order CK>RS>BS. The three dominant bacterial phyla were Proteobacteria, Actinobacteria and Bacteroidetes, and the three dominant fungal phyla were Ascomycota, Basidiomycota and Glomeromycota. Redundancy analysis indicated that total phosphorus concentration and alkaline phosphatase activity significantly influenced bacterial diversity, whereas soil Ca and Mg concentrations were closely related to the fungal community diversity. In conclusion, planting Melia azedarach L. improved soil properties, increased the diversity and richness of soil microbial communities, and thus ameliorated the saline-alkali soil.
Artificial neural networks for solving elliptic differential equations with boundary...
Dongfang Yuan
Wenhui Liu

Dongfang Yuan

and 5 more

December 26, 2020
In this paper, we consider the artificial neural networks for solving the differential equation with boundary layer, in which the gradient of the solution changes sharply near the boundary layer. The solution of the boundary layer problems poses a huge challenge to both traditional numerical methods and artificial neural network methods. By theoretical analyzing the changing rate of the weights of first hidden layer near the boundary layer, a mapping strategy is added in traditional neural network to improve the convergence of the loss function. Numerical examples are carried out for the 1D and 2D convection-diffusion equation with boundary layer. The results demonstrate that the modified neural networks significantly improve the ability in approximating the solutions with sharp gradient.
Negative initial bone marrow aspirate does not rule out acute lymphoblastic leukemia
Monica Davini
Kevin Shiah

Monica Davini

and 2 more

December 26, 2020
Patients with precursor-B-cell acute lymphoblastic leukemia (B-ALL) may initially present with a prodrome, cytopenia(s) with abnormal bone marrow cellularity, but without clonal abnormalities. Prior cases of “indolent ALL” report infections preceding B-ALL diagnosis. Here we describe our institutional experience, eight patients over a 15-year period with a prodrome (2% of B-ALL diagnoses) prior to definitive diagnosis. Patients ranged from 3-15 years of age (median 5 years), requiring a median 3.5 months from presentation to diagnosis, with a median 3 bone marrow aspirates (BMA) to reach definitive diagnosis. Practitioners must be aware that initial negative BMA does not rule out B-ALL.
Fate of mild-to-moderate bicuspid aortic valve disease untreated during ascending aor...
Alessandro Verzini
Marta Bargagna

Alessandro Verzini

and 10 more

December 26, 2020
Background: Bicuspid aortic valve (BAV) is the most common congenital heart defect and it is responsible for an increased risk of developing aortic valve and ascending aorta complications. In case of mild to moderate BAV disease in patients undergoing supracoronary ascending aorta replacement, it is unclear whether a concomitant aortic valve replacement should be performed. Methods: From June 2002 to January 2020, 75 patients with mild-to-moderate BAV regurgitation (± mild-to-moderate stenosis) who underwent isolated supracoronary ascending aorta replacement were retrospectively analyze. Clinical and echocardiographic follow-up was 100% complete (mean: 7.4±3.9 years, max 16.4). Kaplan Meier estimates were employed to analyze long-term survival. Cumulative incidence function for time to re-operation, recurrence of aortic regurgitation (AR)≥3+ and aortic stenosis (AS) greater than moderate, with death as competing risk, were computed. Results: There was no hospital mortality and no cardiac death occurred. Overall survival at 12 years was 97.4±2.5%, 95% CI [83.16-99.63]. At follow-up there were no cases of aortic root surgery whereas 3 patients underwent AV replacement. At 12 years the CIF of reoperation was 2.6±2.5%, 95% CI [0.20-11.53]. At follow up, AR 3+/4+ was present in 1 pt and AS greater than moderate in 3. At 12 years the CIF of AR>2+/4+ was 5.1±4.98% and of AS>moderate 6.9±3.8%. Conclusions: In our study mild to moderate regurgitation of a BAV did not significantly worse at least up to 10 years after isolated supracoronary ascending aorta replacement.
Spontaneous mechanical aortic valve leaflet dislocation during implantation
Emmanouel Papadakis
Thomas Martens

Emmanouel Papadakis

and 2 more

December 26, 2020
Acute or delayed mechanical valve fracture with possible migration is a rare problem seen after valve replacement. We report a patient where mechanical aortic valve leaflet detachment was encountered during implantation. The missing leaflet was retrieved in the left atrium at the level of the right lower pulmonary vein. This has not yet been described, and prompt recognition and intervention is warranted.
Effect of Cardiac Rehabilitation on Atrial Conductions Following Isolated Coronary Ar...
Anil Sahin
Omer Tasbulak

Anil Sahin

and 7 more

December 26, 2020
Background: Cardiac rehabilitation (CR) is associated with improved clinical outcomes in a broad spectrum of cardiac disease. The beneficial effect of CR has been proven in patients with ischemic heart diseases. Post-operative atrial fibrillation (AF) and atrial arrhythmias are common complications following coronary artery bypass grafting (CABG) surgery. The aim of this study was to evaluate the effect of CR on atrial conductions in patients who underwent isolated CABG surgery. Methods: After the exclusion criterion was applied 545 patients were included in the study, retrospectively. One group (Rehab +) included patients who participated in CR program and the other group (Rehab -) included patients who did not want to or could not be participated in CR program after isolated CABG surgery. ECG parameters of Pmax, Pmin and P wave dispersion (PWD) of both groups were compared. Results: All parameters including heart rate, PR interval, Pmax, Pmin and PWD were significantly changed in rehab (+) group after CABG surgery. There was significant change in rehab (+) group when compared to rehab (-) group in terms of parameters of Pmax (P<0.001), Pmin (P<0.001), P wave dispersion (P<0.001). Conclusion: Our findings referred that CR program significantly improved parameters of atrial conduction including Pmax, Pmin and PWD following isolated CABG surgery. Thereby improvement in atrial conduction by CR program following CABG surgery could reduce atrial arrhythmias.
Can gravel augmentation restore thermal functions in gravel-bed rivers? A need to ass...
Baptiste Marteau
Kristell Michel

Baptiste Marteau

and 2 more

December 26, 2020
Gravel augmentation has become common practice to mitigate the effects of decline in upstream sediment supply in gravel-bed rivers. The success of such rehabilitation schemes relies partly on the monitoring strategy and efforts. When long-term monitoring is lacking, some aspects of rehabilitation initiatives suffer more than others, such as insights into functions and functionalities of the river system. Despite temperature being a fundamental parameter determining the general health of river ecosystems, a limited number of studies have tested whether gravel-augmentation can aid restoring thermal functions. With the help of airborne thermal infrared (TIR) imagery, this paper explores the potential positive feedbacks through the monitoring of gravel augmentation actions, of different magnitude, taken on 3 rivers of the Rhône basin in France. A specific trajectory-based Before-After-Control-Impact (BACI) framework using simple indicators, combined with a TIR-based Control-Impact strategy, was designed to assess the success of thermal function restorations based on dynamic fuzzy references. Results indicate that restoring forms is not sufficient to restore thermal functions. The control-impact strategy shows limitations in the sense that two neighbouring reaches can display similar planform characteristics but different thermal functions; what is observed in a control reach should not necessarily be expected following rehabilitation. When assessing thermal processes, a before-after strategy is needed to either serve as a target or help define an adequate target in accordance with changes in the catchment and channel adjustments and responsiveness. We therefore recommend a trajectory-based BACI assessment to identify current biogeophysical conditions within which rehabilitation can be assessed. From a technical perspective, airborne TIR proved to be useful to rapidly map surface temperature over dozens of kilometres at high resolution, and can be advocated as a powerful tool to monitor and diagnose thermal functions of gravel-bed rivers. With an increasing number of rehabilitation schemes, and increasing pressure of global changes on rivers, we suggest that monitoring of water temperature, even with simple but well-designed sampling strategies, becomes a routine part of river rehabilitation projects.
Iterative approximations of common fixed points with simulation results in Banach spa...
Ashis Bera
Ankush  Chanda

Ashis Bera

and 2 more

December 26, 2020
In this article, we propose the Abbas-Nazir three step iteration scheme and employ the algorithm to study the common fixed points of a pair of generalized $\alpha$-Reich-Suzuki non-expansive mappings defined on a Banach space. Moreover, we explore a few weak and strong convergence results concerning such mappings. Our findings are aptly validated by non-trivial and constructive numerical examples and finally, we compare our results with that of the other noteworthy iterative schemes utilizing MATLAB $2017$a software. However, we perceive that for a different set of parameters and initial points, the newly proposed iterative scheme converges faster than the other well-known algorithms. To be specific, we give an analytic proof of the claim that the novel iteration scheme is also faster than that of Liu et al.
The Stabilization Of The Problem Of Transmission Of The Wave Equation with dynamical...
Zhiling Guo
Shugen Chai

Zhiling Guo

and 1 more

December 26, 2020
In this paper, we address exponential stablization of transmission problem of the wave equation with dynamical boundary conditions. Using the classical energy method and multiplier technique, we prove that the energy of system exponentially decays.
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