Residual Jet Research Articles

A RARE COMPLICATION OF MITRAL TEER PROCEDURE: CLIP LATE DETACHMENT AND EMBOLIZATION

Abstract Intraprocedural and late complications of MitraClip implantation have already been described. This report highlights the importance of conventional surgical options in the event of percutaneous treatment failure. An 85–year–old woman with a history of chronic anemia, and thalassemia Minor was referred to our clinic for severe mitral regurgitation (MR) due to a P2 flail with significant calcification of the posterior mitral annulus. During the Heart Team discussion, age and comorbidities led to consider the patient eligible for TEER with the MitraClip system (EuroSCORE II 9,34%; STS score 7,47%). TEER procedure was uneventful: one XTW was deployed at the level of the flail (A2–P2), a second XTW was then placed more lateral to treat a separate residual jet, and one NTW was finally placed between them. MR reduction was considered acceptable (moderate MR, mean grad 6 mmHg). After two months, symptoms worsened, and TTE showed severe MR (no device detachment) with increased sPAP and associated moderate TR. A couple of weeks later, the patient was hospitalized. Chest X–ray revealed clip embolization confirmed by coronary angiography that showed an XTW Clip embolized to the Right coronary sinus with partial occlusion of the ostium. Percutaneous clip retrieval is described in the literature, but the embolized device position and the presence of recurrent severe MR led us to prefer an urgent surgical intervention. Under CPB, the embolized XTW was easily retrieved through a small aortotomy; the intervention was completed by mitral valve replacement and tricuspid valve repair. The postoperative course was uneventful. Predischarge TTE showed normal mitral bioprosthesis function, mild AR, mild TR, and preserved LV function. DISCUSSION Clip embolization is a rare but potentially critical complication of TEER and can happen periprocedurally or on early follow–up. Single leaflet detachment is more common, but complete detachment and embolization can occur. Therapeutic options are represented by surgical or transcatheter approaches according to embolization sites and patient comorbidities. In our case, the risk of potential coronary obstruction or thrombosis and the concomitant need for MR treatment have led us to consider surgery as the first option. CONCLUSION TEER can be graved by acute or late complications. The best approach has to be tailored to each patient, and surgery can be an effective and safe option even for initially discarded high–risk patients.

Gender Specified In-Hospital Outcome after Left Atrial Appendage Closure with a Dual Occlusive Mechanism Device

Background: Recent studies have suggested an increased rate of adverse events in women following left atrial appendage occlusion (LAAO), particularly with dual occlusive mechanism devices. Objectives: This study aimed to investigate gender disparities in in-hospital adverse events and short-term device-related outcomes in an experienced center using dual occlusive mechanism devices exclusively. Methods: In a single-center retrospective study, patients who received dual occlusive mechanism devices (Amplatzer cardiac plug and Amulet) were analyzed. We assessed gender differences in patient characteristics, LAAO indications, procedural data, in-hospital complications, and short-term device-related outcomes in the form of one-month follow-up transesophageal echocardiography. Results: Among 474 patients, 211 (45%) were women. At device implantation, women were significantly older (77.45±6.98 years vs. 75.89±7.26; p = 0.01), with higher CHA2DS2Vasc scores (5.03±1.46 vs. 4.28±1.51; p < 0.01) and lower HASBLED scores (3.78±1.06 vs. 4.03±1.12; p = 0.01) compared to men. Men had a higher prevalence of coronary artery disease (52% vs. 32%; p < 0.01). LAAO indications did not significantly differ. Device success was 99% in men and 98% in women (p = 0.75). In-hospital complications, including deaths, major bleedings, and pericardial effusion, did not significantly vary by gender. Rates of device-related thrombus and device closure with a residual jet ≤ 5 mm were similar. Conclusions: In a large cohort of consecutive LAAO patients at an experienced center, gender was not linked to higher in-hospital complications.

Outcomes of the roll-in cohort of the Amulet IDE trial of left atrial appendage occlusion.

Left atrial appendage (LAA) occlusion is an alternative therapy to oral anticoagulants to reduce stroke risk in patients with nonvalvular atrial fibrillation (NVAF). The Amulet IDE trial compared the Amplatzer™ Amulet™ occluder (Abbott) with the Watchman™ 2.5 device (Boston Scientific) for LAA occlusion in patients with NVAF. The purpose of this study was to describe outcomes of the Amulet IDE trial roll-in cohort. At US sites up to 3 patients per implanter could be implanted with the Amulet occluder in the roll-in phase. The primary Endpoints in the Amulet IDE trial included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months), effectiveness (composite of ischemic stroke or systemic embolism at 18 months), and rate of LAA occlusion at 45 days. A total of 201 roll-in patients were enrolled. Device success occurred in 99% of patients, and device closure (residual jet ≤5 mm) was observed in 98.9% of patients at 45 days. The safety endpoint rate was numerically higher (worse) in the roll-in cohort compared to the randomized Amulet occluder cohort (18.4% vs 14.5%). Six patients (3.1%) experienced an ischemic stroke and 0 patients with a systemic embolism within 18 months, which was similar to the primary effectiveness endpoint rate in the randomized Amulet occluder cohort (2.8%). Despite lack of experience of the operators with the Amulet occluder in the roll-in phase, device implant success was high, a high rate of device closure was achieved, and low stroke rates were observed in patients with NVAF.

Transcatheter Mitral Valve Repair Technique in Specific Severe Mitral Regurgitation: Tips, Tricks, and Outcomes

BackgroundIn specific patients with severe mitral regurgitation (MR), mitral valve (MV) pathology is unique and requires creative transcatheter repair techniques. This study aimed to evaluate the feasibility and safety of a new transcatheter MV repair technique, using occluder devices in symptomatic high-surgical-risk patients with severe MR, either due to MV leaflet (MVL) perforations or due to post-clips residual MR, and to report on their 6-month outcomes. MethodsThe study enrolled all high-risk patients with severe MR due to MVL perforations and post-clips residual MR who underwent transcatheter MV repair using occluder devices, from November 2016 to August 2019. ResultsThe study enrolled 16 patients; 9 (56.25%) with MVL perforations and 7 (43.75%) with post-MitraClip (Abbott Laboratories, Abbott Park, Illinois) residual MR, with a mean age of 55.75 ± 16.69 years. Mean perforation/jet diameters were 5.75 ± 1.67 and 6.5 ± 1.93 mm, and the mean 3D-vena contracta area was 0.54 ± 0.14 cm2. Perforations were crossed retrograde (transaortic in 7 [43.75%] patients and transapical in 2 [12.5%] patients), and post-MitraClip devices residual jets were crossed antegrade (transvenous/transseptal). Six (37.5%) patients required arteriovenous loop formation for device deployment, that was antegrade transvenous/transseptal in 13 (81.25%) patients and retrograde transapical in 3 (18.75%) patients. Devices used were Amplatzer-ASO in 10 (62.5%) patients and Amplatzer-VP-II in 6 (37.5%) patients. Mean procedural and fluoroscopy times were 55.13 ± 16.24 and 16.25 ± 4.03 ​minutes, respectively. Patients passed successfully, without MV gradient change or device-related complications. ConclusionsTranscatheter MV repair of MVL perforations/post-clips residual MR is a new, feasible, and safe technique for high-surgical-risk patients.

Experimental and Numerical Study on the Penetration Performance of a Shaped Charge.

In guided ammunition, because a shaped energy jet warhead is located behind the control cabin (including the guidance cabin, the steering gear cabin, and the flight control cabin), the penetration order of a shaped energy jet is the control cabin and the target plate. In order to obtain maximum penetration depth by a shaped energy jet into a Q235 steel plate, the penetration performance of shaped energy jets was studied by numerical simulation and experimental verification. Firstly, the penetration performance of a warhead under different conditions at a certain explosion height is studied, which is the penetration performance of a Q235 steel plate with and without the control cabin. Secondly, the numerical simulation results are verified by experimental method. The numerical simulation and experimental results showed that, after penetration of the shaped energy jet warhead into the control cabin, it continued to penetrate the 20 mm-thick Q235 steel plate. At a certain explosion height, the maximum penetration depth of the shaped energy jet warhead into the Q235 steel plate was about 80 mm. Alongside the numerical simulation and experiment, the armor-breaking process of the shaped charge jet was analyzed theoretically. The results show that when the shaped energy jet warhead is located behind the control cabin, although the control cabin will have a certain impact on the penetration ability of shaped energy jet, the penetration performance of the residual jet still has the ability to penetrate light armor.

Deformation Behavior and Microstructure Evolution of CoCrNi Medium-Entropy Alloy Shaped Charge Liners

To investigate the microstructure evolution and dynamic deformation behavior of a CoCrNi medium entropy alloy under an ultrahigh explosive loading rate, CoCrNi-shaped charged liners were fabricated and fired into steel targets. Targets with residual jet fragments were recovered for detailed microstructural analysis using scanning electrical microscopy, X-ray diffraction, electron backscattered diffraction, and transmission electron microscopy. The results indicate that the grain size was reduced by more than 3 times and grains were found to be equiaxed in the residual jet, which indicates that dynamic recrystallization (DRX) occurred during this extremely high strain rate and large plastic deformation. Furthermore, the content of Cr element in CoCrNi at the grain boundaries increased significantly after detonation deformation. The reduced grain sizes are believed to reduce the bulk diffusion path of Cr from grain interior into grain boundaries with the support of sufficient energy provided by the ultrahigh temperature. The enrichment of Cr at grain boundaries promotes the formation of nanosized Cr-rich precipitates with body-centered cubic (BCC) structures, which were found to be widely distributed along grain boundaries in the residual jet. These precipitates were considered obstacles for grain boundary movement and promotion of crack initiation along the grain boundaries, which might cause ductility loss of the CoCrNi-shaped charge jet and loss of penetration capability.

369 Mono-orifice mitral valve after transcatehter repair with mitraclip system

Abstract A 70 years old male with non-ischaemic dilated cardiomyopathy (left ventricular end-diastolic volume, LVEDV, 200 mL), reduced left ventricular ejection fraction (LVEF, 30%) and worsening dyspnoea was screened for transcatheter repair of severe mitral regurgitation (MR). Baseline echocardiogram showed marked symmetrical bi-leaflet tethering with a symmetrical central jet. Etiology was predominantly functional with organic features including partial flail scallop (A1) and a ruptured second order chorda (Figure 1A). Pre-operative strategy was to deploy a single MitraClip NT in the central position. After correct deployment of the first clip, we observed a remarkable reduction of regurgitant jets in the lateral position accompanied by a complete holosystolic lack of leaflet coaptation in the medial orifice which caused significant residual regurgitation. (Figure 1B) MitraClip deployment in the commissural position is associated with technical challenges, including limited maneuvering, risk of chordae rupture and inability to retrieve the device if entangled. (1) Therefore, after careful crossing of the medial neo-orifice and rapid positioning a second MitraClip NT was implanted medial to the first device in the commissural position (Figure 2). As a result, the medial orifice was obliterated resulting in an atypical mono-orifice morphology which resembles a commissural edge-to-edge plasty. Anterograde flow was normal (G med 2.5 mmHg) and the trivial residual jet of MR was lateral to the two clips implanted. At 1-year follow-up the patient was asymptomatic (NYHA functional class I) with a stable mild MR and no change in anterograde gradients; positive remodelling of the left ventricle (LVEDP: −48 ml) and increased LVEF (+8%) were observed. 369 Figure 1.

Orthogonal Analysis of Linear Shaped Charges Jet Penetrating Layered Targets

This paper reports on the linear shaped charges (LSCs) jet penetrates into double layer spaced targets. The distance between the LSCs and the first layer target is 0.2 times width of the LSCs, the distance between the LSCs and the second layer target is 25 times width of the LSCs. The mechanism of LSCs penetrate into the double layer spaced targets causing less collateral damage in terms of jet residues has been studied by experiment and numerical simulation. After the LSCs has been crashed by detonation wave, a linear metal jet formed and penetrates into the first layer plate, then the jet is separated into jet tip and slug. The jet tip penetrates into the second layer plate and consumed, then a strip pit formed on the surface of the back plate. The slug penetrates into the second layer plate subsequently and consumed. Due to the stress concentration and tensile fracture, the second layer target is broken and less residue of jet pass it. Experiments were made and the results indicated that the numerical simulation results agreed fully with the physical principle. A verification plate was used in the experiment to test the collateral damage of residual jets. When the space between verification plate and back plate of the layered target is 500mm, both of the experimental results and simulation results show that there is no obvious damage to people. The relationship between the performance of jet and the parameters of LSCs has been analyzed by an orthogonal method (significance test and interaction effect analysis). A good teamwork should be done for all the key parameters of LSCs which can break the spaced targets with less collateral damage.

Abstract 17230: Transcatheter Leak Occlusion With Endovascular Coils Following Left Atrial Appendage Closure

Introduction: The Transcatheter Leak Closure With Detachable Coils Following Incomplete Left Atrial Appendage Closure Procedures (TREASURE) is a prospective, nonrandomized, single-center study. This study was undertaken to investigate the efficacy of transcatheter leak closure with endovascular coils in patient with incomplete percutaneous/epicardial left atrial appendage (LAA) closure procedures and high thromboembolic (TE)- and bleeding-risk. Hypothesis: We report the efficacy of transcatheter leak closure with endovascular coils in patients with incomplete LAA closure. Methods: Sixty-five consecutive patients with a clinically relevant residual leak (mean age: 72±8 years; 73.8% males; CHA 2 DS 2 -VASc: 4.7±1.1; HAS-BLED: 3.7±0.7) underwent percutaneous closure of the LAA patency via embolization coils. Trans-esophageal echocardiography (TEE) was performed at 60±15 days post-procedure. Results: LAA closure had been previously attempted with a Watchman device in 62 patients, and a LARIAT in 3. Baseline TEE documented a moderate or severe leak in 14 (21.5%) and 51 (78.5%) patients, respectively. Procedure and fluoroscopy times were 69±37min and 22±15min, respectively; the mean volume of iodinated contrast medium used was 82±43mL. Coil deployment was successful in all cases [median n. of coils attempted: 3 (IQR:2-5); median n. of coils deployed: 3 (IQR: 2-4)]. The overall complication rate was 3.1% (1 pericardial tamponade, 1 pericardial effusion). Peri-procedural angiographic and TEE outcomes demonstrated complete obliteration or a negligible residual opacification with a trivial residual jet in 62 cases (95.4%), and a partial occlusion with moderate residual jet in 3 (6.4%). Follow-up TEE after 67±12 days revealed complete LAA sealing or a negligible residual leak in 63 cases (96.9%). Coil deployment led to an average reduction of 90.1% in leak size (p<0.001). After an overall follow-up of 17±4 months, no TE events were documented; 3 patients died from non-cardiovascular and one from cardiovascular causes (heart failure). Conclusions: Transcatheter LAA leak occlusion via endovascular coils appears to be a safe, effective, and promising approach in high TE-risk patients with incomplete LAA closure.

Breaking of Internal Kelvin Waves Shoaling on a Slope

AbstractIn stratified flow, breaking of internal waves over slopes induces resuspension of bottom sediments and transport of mass. When internal waves shoal and break, flow dynamics and mass transport differ significantly according to whether the Coriolis force is included or neglected. Despite its importance, the currents generated by breaking internal Kelvin waves remain uninvestigated. Therefore, this study considers breaking of internal waves over a uniform slope under Coriolis with equivalent upper‐ and lower‐layer depths. Laboratory experiments, using a 6.0‐m rotating tank, were undertaken to visualize currents using particle image velocimetry. Experimental data validated a three‐dimensional fluid dynamics model, in which a phase‐averaged velocity (residual jet) was simulated to occur at the lateral wall (to the right) of the progressive internal Kelvin waves in the breaking zone, with the generation of an oblique downslope return flow (downdraft) under Coriolis. The geostrophic balance drove the residual jet, and the equation for estimating the residual current, due to the jet, was formulated and was discussed by referring a coastal jet in Lake Erie. The results provide insight on mass transport in lakeshore and coastal zones.

Influence of a liquid-filled compartment structure on the incoming shaped charge jet stability

Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts. The liquid-filled compartment structure can resist the shaped charge warhead effectively. This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles. On the basis of shock wave propagation theory, the influence of the liquid-filled compartment structure on jet stability is analysed. The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined. In addition, the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the residual jet are obtained. A theoretical model is validated against the experimental penetration depths.

Discussion

Discussion

P4366Application of 3D-dual volume layout imaging for rapid intraprocedural guidance in Mitraclip procedure

Abstract Introduction Intraprocedural guidance and monitoring with transesophageal echocardiography (TEE) and invasive hemodynamic assessment are currently the best available options for evaluating procedural success of percutaneous mitral valve (MV) repair with Mitraclip System (Abbott Vascular, Santa Clara, CA, USA). However, despite its crucial importance, echocardiography has some limitations in immediate evaluation of residual jets after clip implantation, so that, in absence of validated method for double orifice effective regurgitant orifice (ERO) assessment, the most reliable parameter that is currently used is the mean trans-valvular gradient. Purpose This prospective study aimed to assess the role of a new echocardiographic parameter obtained from 3D-Color-Full volume imaging of MR for evaluation of outcomes of mitraclip procedures, comparing it with invasive LAP measurements. Material and methods We prospectively performed the computation of a new parameter in patients with symptomatic moderate-severe to severe primary or secondary mitral regurgitation (MR) underwent MitraClip procedure. This parameter is easy and fast to be obtained out of 3D dataset and represents the 2D area of the proximal isovelocity surface zone visualized from the ventricular view, without any imaging processing (“3D dual volume PISA area”) (figure). It was obtained as following: i) acquisition of 3D-zoomed-color image of MR jet with adequate frame rates; ii)displaying of the volume sampling in “dual volume layout” so one can see the “ventricular aspect” of the jet area corresponding to proximal isovelocity surface “zone”; iii) awareness of correct alignment to the direction of the flow in proximal zone; iiii) freezing and direct measurement of this area (summarize if more than 1 orifice) (1 attached). We compared the variation of this parameter from the beginning to end of procedure with the variation of LAP measurements, that is currently the most important parameter for assessing outcome of procedures. Results The study includes dataset of 11 patients. The baseline value of 3D dual volume PISA area was 1,191±0,40 cm2 and the mean change we obtained was 0,65±0,30 cm2 (mean of 77% of reduction until the end of procedure). Mean values of LAP were slightly decreased in all cases: basal m-LAP was 12±3,3 mmHg and decreased by 15%. Despite the small number of patients, we observed a significant correlation between the changes of LAP and the change of 3D dual volume PISA area (R: 0.6, p: 0,048). Conclusions This is the first demonstration of the usefulness of echocardiographic parameter obtained by 3Ddual volume layout imaging for rapid intraprocedural guidance in Mitraclip procedure. This parameter is related to hemodynamic variations that it currently considerable surrogate of outcomes. These data need to be confirmed by a larger study.

Rationale and design for AMPLATZER Amulet Left Atrial Appendage Occluder IDE randomized controlled trial (Amulet IDE Trial)

The Amulet IDE Trial is an ongoing, prospective, randomized, multi-national trial, designed to evaluate the safety and effectiveness of the AMPLATZER Amulet Left Atrial Appendage Occluder for stroke prevention in comparison to the WATCHMAN Left Atrial Appendage Closure Device in patients with non-valvular atrial fibrillation. METHODS: Non-valvular atrial fibrillation patients at high risk of stroke (CHADS2 score ≥2 or a CHA2DS2-VASc score of ≥3) who are suitable candidates for left atrial appendage occlusion (LAAO) will be fully informed and requested to participate in the trial. A total of 1878 patients at up to 150 sites worldwide will be randomized in a 1:1 ratio between the AMPLATZER Amulet device (investigational) and the Boston Scientific WATCHMAN device (control). Each patient will be followed for 5 years, with follow-up assessments at discharge, 45 days, 3, 6, 9, 12, 18, and 24 months and then annually. The trial has three primary endpoints: A composite of procedure-related complications, or all-cause death, or major bleeding through 12 months (safety); a composite of ischemic stroke or systemic embolism through 18 months (effectiveness); and effective device LAAO, defined as residual jet around the device ≤5 mm at the 45-day visit (mechanism of action). SUMMARY: The Amulet IDE Trial is the first randomized head-to-head LAAO device trial and will provide data for the AMPLATZER Amulet occluder in a population with a high risk of stroke and bleeding.

Left atrial appendage occlusion with lambre in atrial fibrillation: Initial European experience

BackgroundWe here report the first European experience with the novel LAmbre left atrial appendage (LAA) occluder, a self-expanding device consisting of an umbrella and a cover connected by a central waist. Methods and resultsA total of 60 patients (74.4 ± 8.3 years; 66.7% men; CHA2DS2-VASc: 4.0 ± 1.6, HAS-BLED score: 3.2 ± 1.3) with atrial fibrillation and contraindications to oral anticoagulation underwent left atrial appendage occlusion (LAAO) with the LAmbre device at two German centers between November 2013 and September 2015.Device success defined as correct placement of the device was achieved in all patients (100%). Resizing of the device was necessary in 3 (5%) patients. Device-related complications included 2 (3.3%) pericardial effusions on day 8 and 33 after the index procedure requiring pericardiocentesis. Transesophageal echocardiography at 6 months showed complete sealing of the LAA (residual jet flow of <5 mm) in 51/54 (94.4%) patients. No device-related thrombus was documented. At 12 months transient ischemic attack was observed in 1 patient (1.6%) and minor bleeding in 3 patients (5%). ConclusionsAlthough minimizing procedure-related complications remains challenging, LAAO with the LAmbre showed high device success and good mid-term performance regarding prevention of stroke and bleeding.

Material combination to mitigation of behind armour debris after shaped charge jet attack

When a shaped charge jet perforates the steel armour plate, the residual jet is accompanied by a much wider cloud of behind armour debris (BAD) generated by stress wave interactions. BAD plays an important role in the evaluation of survivability of vehicle crew and components in a vehicle. The Behind Armor Debris (BAD) cloud caused by shaped charge jet impact was investigated. In order to simulate different configuration of material to mitigation of debris cloud the thickness of ceramics target tiles, glass and aramid laminate liners in contact with the armour plates was varied.

ATLAS jet and missing-ET reconstruction, calibration, and performance

The ATLAS experiment has achieved a very high precision on jet and missing transverse energy performance by the use of advanced calorimeter-based topological clustering and local cluster calibration, event-by-event pile-up subtraction methods, and in situ techniques to correct for the residual jet energy response difference between data and simulation. Tracking information is being combined with calorimeter to further improve the jet and missing transverse energy performance. ATLAS has also commissioned several new powerful tools for the analysis and interpretation of hadronic final states at the LHC such as jet substructure, jet mass, quark-gluon discrimination, and jet tagging tools for the identification of boosted heavy particles. An overview of the reconstruction, calibration, and performance of jets, missing transverse energy, jet substructure, and jet tagging at ATLAS is presented.

Three-dimensional Echocardiography Is Not Essential for Intraoperative Assessment of Mitral Regurgitation

The problem is not what you see on intraoperative echocardiography; it is what you do not see. Intraoperative transesophageal echocardiography and 3-dimensional (3D) echocardiography provide useful information for the surgeon performing mitral valve surgery, but they are not indispensable. We should consider the outstanding results of the pioneer of mitral valve repair, Professor Alain Carpentier. A report of very late results (>20 years) of the earliest series (1970–1984) of mitral valve repair is informative.1 Even without the availability of intraoperative transesophageal echocardiography, the late results were outstanding. At 20 years, freedom from reoperation was 96.9% for patients with posterior leaflet prolapse and 86.2% for patients with anterior prolapse. At the last follow-up (median, 17 years) 15% had moderate or worse mitral regurgitation. An experienced mitral valve surgeon can achieve durable high-quality results without any echocardiography, so 3D echocardiography is not essential. Response by Tsang and Lang on p 658 What is essential for mitral valve surgery? The fundamental elements from the surgical standpoint are the same whether the procedure is performed through a sternotomy or a minimally invasive incision or is robotically assisted. Achieving good surgical exposure is paramount.2 Numerous surgical techniques, including the type and location of venous cannulation, the atrial incision, retraction of the atrial wall, sutures to help rotate the valve and improve visualization, and occasionally the use of an instrument pushing from outside the heart to facilitate exposure of commissures or the anterior leaflet, are routine practice to optimally visualize the valve. Unless the surgeon is expert in the first step of the procedure, results will be compromised. A perfect 3D echocardiography image of the valve will not compensate for poor exposure. Although real-time 3D color echocardiography is useful, there is nothing more realistic than real-time 3D color visualization through 2.5-power loupes by the …

Detection of X-rays from the jet-driving symbiotic star Hen 3-1341

Hen 3-1341 is a symbiotic binary system consisting of a white dwarf and a red giant star that is one of about ten symbiotics that show hints of jets. The bipolar jets have been detected through displaced components of emission lines during its outburst from 1998 to 2004. These components disappeared when Hen 3-1341 reached quiescence. On February 23, 2012, Hen 3-1341 started a new outburst with the emergence of new bipolar jets on March 3, 2012. We observed Hen 3-1341 during quiescence with XMM-Newton in March 2010 with an effective exposure time of 46.8 ks and with Swift on March 8-11, 2012 as ToO observations with an effective exposure time of 10 ks in order to probe the interaction of the jet with the ambient medium and also the accretion onto the white dwarf. We fitted the XMM-Newton X-ray spectra with XSPEC and examined the X-ray and UV light curves. We report the detection of X-ray emission during quiescence from Hen 3-1341 with XMM-Newton. The spectrum can be fitted with an absorbed one-temperature plasma or an absorbed blackbody. We did not detect Hen 3-1341 during our short Swift exposure. Neither periodic or aperiodic X-ray nor UV variability were found. Our XMM-Newton data suggest that interaction of the residual jet with the interstellar medium might survive for a long time after outbursts and might be responsible for the observed X-ray emission during quiescence. Additional data are strongly needed to confirm these suggestions.

Head-on collision of two solitary waves and residual falling jet formation

Abstract. The head-on collision of two equal and two unequal steep solitary waves is investigated numerically. The former case is equivalent to the reflection of one solitary wave by a vertical wall when viscosity is neglected. We have performed a series of numerical simulations based on a Boundary Integral Equation Method (BIEM) on finite depth to investigate during the collision the maximum runup, phase shift, wall residence time and acceleration field for arbitrary values of the non-linearity parameter a/h, where a is the amplitude of initial solitary waves and h the constant water depth. The initial solitary waves are calculated numerically from the fully nonlinear equations. The present work extends previous results on the runup and wall residence time calculation to the collision of very steep counter propagating solitary waves. Furthermore, a new phenomenon corresponding to the occurrence of a residual jet is found for wave amplitudes larger than a threshold value.