Phonon-Mediated Quasiparticle Lifetime Renormalizations in Few-Layer Hexagonal Boron Nitride.

Understanding the collective behavior of the quasiparticles in solid-state systems underpins the field of nonvolatile electronics, including the opportunity to control many-body effects for well-desired physical phenomena and their applications. Hexagonal boron nitride (hBN) is a wide-energy-bandgap semiconductor, showing immense potential as a platform for low-dimensional device heterostructures. It is an inert dielectric used for gated devices, having a negligible orbital hybridization when placed in contact with other systems. Despite its inertness, we discover a large electron mass enhancement in few-layer hBN affecting the lifetime of the π-band states. We show that the renormalization is phonon-mediated and consistent with both single- and multiple-phonon scattering events. Our findings thus unveil a so-far unknown many-body state in a wide-bandgap insulator, having important implications for devices using hBN as one of their building blocks.

Spatial Interactions in Hydrogenated Perovskite Nickelate Synaptic Networks.

A key aspect of how the brain learns and enables decision-making processes is through synaptic interactions. Electrical transmission and communication in a network of synapses are modulated by extracellular fields generated by ionic chemical gradients. Emulating such spatial interactions in synthetic networks can be of potential use for neuromorphic learning and the hardware implementation of artificial intelligence. Here, we demonstrate that in a network of hydrogen-doped perovskite nickelate devices, electric bias across a single junction can tune the coupling strength between the neighboring cells. Electrical transport measurements and spatially resolved diffraction and nanoprobe X-ray and scanning microwave impedance spectroscopic studies suggest that graded proton distribution in the inhomogeneous medium of hydrogen-doped nickelate film enables this behavior. We further demonstrate signal integration through the coupling of various junctions.

The effect of normobaric hypoxia on acute exercise-induced changes in blood sphingoid base-1-phosphates metabolism in cyclists.

Extracellular sphingosine-1-phosphate (S1P) emerged as an important regulator of muscle function. We previously found that plasma S1P concentration is elevated in response to acute exercise and training. Interestingly, hypoxia, which is commonly utilized in training programs, induces a similar effect. Therefore, the aim of the current study was to determine the effect of normobaric hypoxia on exercise-induced changes in blood sphingolipid metabolism. Fifteen male competitive cyclists performed a graded cycling exercise until exhaustion (GE) and a simulated 30 km individual time trial (TT) in either normoxic or hypoxic (FiO2 = 16.5%) conditions. Blood samples were taken before the exercise, following its cessation, and after 30 min of recovery. We found that TT increased dihydrosphingosine-1-phosphate (dhS1P) concentration in plasma (both HDL- and albumin-bound) and blood cells, as well as the rate of dhS1P release from erythrocytes, regardless of oxygen availability. Plasma concentration of S1P was, however, reduced during the recovery phase, and this trend was augmented by hypoxia. On the other hand, GE in normoxia induced a selective increase in HDL-bound S1P. This effect disappeared when the exercise was performed in hypoxia, and it was associated with reduced S1P level in platelets and erythrocytes. We conclude that submaximal exercise elevates total plasma dhS1P concentration via increased availability of dihydrosphingosine resulting in enhanced dhS1P synthesis and release by blood cells. Maximal exercise, on the other hand, induces a selective increase in HDL-bound S1P, which is a consequence of mechanisms not related to blood cells. We also conclude that hypoxia reduces post-exercise plasma S1P concentration.

Fast Surface Oxygen Release Kinetics Accelerate Nanoparticle Exsolution in Perovskite Oxides.

Exsolution is a recent advancement for fabricating oxide-supported metal nanoparticle catalysts via phase precipitation out of a host oxide. A fundamental understanding and control of the exsolution kinetics are needed to engineer exsolved nanoparticles to obtain higher catalytic activity toward clean energy and fuel conversion. Since oxygen release via oxygen vacancy formation in the host oxide is behind oxide reduction and metal exsolution, we hypothesize that the kinetics of metal exsolution should depend on the kinetics of oxygen release, in addition to the kinetics of metal cation diffusion. Here, we probe the surface exsolution kinetics both experimentally and theoretically using thin-film perovskite SrTi0.65Fe0.35O3 (STF) as a model system. We quantitatively demonstrated that in this system the surface oxygen release governs the metal nanoparticle exsolution kinetics. As a result, by increasing the oxygen release rate in STF, either by reducing the sample thickness or by increasing the surface reactivity, one can effectively accelerate the Fe0 exsolution kinetics. Fast oxygen release kinetics in STF not only shortened the prereduction time prior to the exsolution onset, but also increased the total quantity of exsolved Fe0 over time, which agrees well with the predictions from our analytical kinetic modeling. The consistency between the results obtained from in situ experiments and analytical modeling provides a predictive capability for tailoring exsolution, and highlights the importance of engineering host oxide surface oxygen release kinetics in designing exsolved nanocatalysts.

The fus test: a promising tool for evaluating fundamental motor skills in children and adolescents.

Fundamental motor skills (FMS) are essential for enjoyable, confident and skillful participation in physical activity across the lifespan. Due to the alarming low level of FMS proficiency in children and adolescents worldwide, the development of motor competency is an urgent issue for physical education. The promotion and implementation of a systematic process of teaching and learning FMS should be a physical education priority. Accordingly, effective assessment tools for evaluating FMS should be adopted or developed. Because FMS assessment for both children and adolescents need further effective solutions, the primary aim of this study was to develop the new age-related test of FMS (Fundamental Motor Skills in Sport test, in Polish: Test Fundamentalnych Umiejetnosci Ruchowych w Sporcie, FUS). The secondary aim of this study was to establish validity and inter-rater, intra-rater, test-retest reliabilities and internal consistency of the FUS test. The FUS test involves six sport skill-based tasks: hurdling, jumping rope, forward roll, ball bouncing, throwing and catching a ball, and kicking and stopping a ball. Two hundred sixty-four Polish students in grades 1-3 (7-9 yrs; n = 81), 4-6 (10-12 yrs; n = 89) and 7-8 (13-14 yrs; n = 94), including 139 girls and 125 boys completed the FUS test. The content validity index for all items was notably high. Both inter-rater and intra-rater reliability showed substantial to almost perfect agreement, with observed agreements for FUS skills between 78.5 and 93.1%. Ball bouncing had a moderate correlation with the forward roll and throwing and catching, while other correlations were low or insignificant. ICC values, ranging from 0.95 to 0.97, confirmed excellent test-retest reliability. The results of our study provide evidence that the FUS test is valid, reliable, and feasible to administer in school settings. Therefore, this tool test has the potential to support deliberate practice and improve motor competence by providing a standardized and structured approach to measuring FMS among school-aged children and adolescents.

Exsolution-Driven Surface Transformation in the Host Oxide.

Exsolution synthesizes self-assembled metal nanoparticle catalysts via phase precipitation. An overlooked aspect in this method thus far is how exsolution affects the host oxide surface chemistry and structure. Such information is critical as the oxide itself can also contribute to the overall catalytic activity. Combining X-ray and electron probes, we investigated the surface transformation of thin-film SrTi0.65Fe0.35O3 during Fe0 exsolution. We found that exsolution generates a highly Fe-deficient near-surface layer of about 2 nm thick. Moreover, the originally single-crystalline oxide near-surface region became partially polycrystalline after exsolution. Such drastic transformations at the surface of the oxide are important because the exsolution-induced nonstoichiometry and grain boundaries can alter the oxide ion transport and oxygen exchange kinetics and, hence, the catalytic activity toward water splitting or hydrogen oxidation reactions. These findings highlight the need to consider the exsolved oxide surface, in addition to the metal nanoparticles, in designing the exsolved nanocatalysts.

Temperature-independent thermal radiation.

Thermal emission is the process by which all objects at nonzero temperatures emit light and is well described by the Planck, Kirchhoff, and Stefan-Boltzmann laws. For most solids, the thermally emitted power increases monotonically with temperature in a one-to-one relationship that enables applications such as infrared imaging and noncontact thermometry. Here, we demonstrated ultrathin thermal emitters that violate this one-to-one relationship via the use of samarium nickel oxide (SmNiO3), a strongly correlated quantum material that undergoes a fully reversible, temperature-driven solid-state phase transition. The smooth and hysteresis-free nature of this unique insulator-to-metal phase transition enabled us to engineer the temperature dependence of emissivity to precisely cancel out the intrinsic blackbody profile described by the Stefan-Boltzmann law, for both heating and cooling. Our design results in temperature-independent thermally emitted power within the long-wave atmospheric transparency window (wavelengths of 8 to 14 µm), across a broad temperature range of ∼30 °C, centered around ∼120 °C. The ability to decouple temperature and thermal emission opens a gateway for controlling the visibility of objects to infrared cameras and, more broadly, opportunities for quantum materials in controlling heat transfer.

Sudden Collapse of Magnetic Order in Oxygen-Deficient Nickelate Films.

Antiferromagnetic order is a common and robust ground state in the parent (undoped) phase of several strongly correlated electron systems. The progressive weakening of antiferromagnetic correlations upon doping paves the way for a variety of emergent many-electron phenomena including unconventional superconductivity, colossal magnetoresistance, and collective charge-spin-orbital ordering. In this study, we explored the use of oxygen stoichiometry as an alternative pathway to modify the coupled magnetic and electronic ground state in the family of rare earth nickelates (RENiO_{3-x}). Using a combination of x-ray spectroscopy and resonant soft x-ray magnetic scattering, we find that, while oxygen vacancies rapidly alter the electronic configuration within the Ni and O orbital manifolds, antiferromagnetic order is remarkably robust to substantial levels of carrier doping, only to suddenly collapse beyond 0.21 e^{-}/Ni without an accompanying structural transition. Our work demonstrates that ordered magnetism in RENiO_{3-x} is mostly insensitive to carrier doping up to significant levels unseen in other transition-metal oxides. The sudden collapse of ordered magnetism upon oxygen removal may provide a new mechanism for solid-state magnetoionic switching and new applications in antiferromagnetic spintronics.

Quantum-Well Bound States in Graphene Heterostructure Interfaces.

We present experimental evidence of electronic and optical interlayer resonances in graphene van der Waals heterostructure interfaces. Using the spectroscopic mode of a low-energy electron microscope (LEEM), we characterized these interlayer resonant states up to 10 eV above the vacuum level. Compared with nontwisted, AB-stacked bilayer graphene (AB BLG), an ≈0.2 Å increase was found in the interlayer spacing of 30° twisted bilayer graphene (30°-tBLG). In addition, we used Raman spectroscopy to probe the inelastic light-matter interactions. A unique type of Fano resonance was found around the D and G modes of the graphene lattice vibrations. This anomalous, robust Fano resonance is a direct result of quantum confinement and the interplay between discrete phonon states and the excitonic continuum.

Fabrication of field-effect transistors with transfer-free nanostructured carbon as the semiconducting channel material.

Carbon nanostructures used as the active channel material in field effect transistors (FETs) are appealing in microelectronics for their improved performance, such as their high speed and low energy dissipation. However, these devices require the incorporation of nanostructure transfer steps in the fabrication process flow, which makes their application difficult in large scale integrated circuits. Here we present a novel method for the fabrication of FETs with nanostructured carbon in the channel with p-type semiconducting properties and intermediate drain-source current (IDS ) on/off ratio. The method is based on the use of Ni nanoparticles in the source-drain gap region as the seed material for the formation of carbon nanostructures in the FET channel. FETs without Ni nanoparticles in the channel showed no modulation of IDS as a function of gate voltage. The device fabrication process does not require any carbon nanostructure transfer steps since it directly forms carbon nanostructures electrically connected to the device's source and drain electrodes via electron-beam evaporation of carbon and conventional lithographic processes. Since all device fabrication steps are compatible with existing Si technology processes, they are capable of being further optimized following process development protocols practiced by the semiconductor industry.

The effect of unilateral training on contralateral limb power in young women and men.

The purpose of this study was to determine the effect of training of one side of the body on the muscle torques and power output on the trained and untrained side. Seventeen female and twenty-two male students were subject to a four-week knee joint power training regimen on a specially designed stand. The subjects were divided into two groups: a training group (female - N = 11 and male - N = 16) and a control group (female - N = 6 and male - N = 6). Effectiveness of power training on the stand described previously was estimated based on bilateral knee torque and power under static and isokinetic conditions. The experiment lasted for 39 days and was preceded by preliminary studies (pre-training). Control measurements in training groups were made after four weeks of training (post-training) and after the next two weeks (de-training). Power training caused an insignificant increase in force and power in both groups for the untrained leg and a significant increase in RMS EMG. Therefore, the study confirmed the hypothesis that resistance training performed in dynamic conditions can affect the contralateral limb and may also trigger delayed adaptations to training conditions during the detraining phase. Sex differences in adaptation to power training are not clear; however, the differences in gains in contralateral effects between men and women were not confirmed.

Long-term clinical outcomes from real-world experience of left atrial appendage exclusion with LARIAT device.

BACKGROUND: Left atrial appendage closure (LAAC) with LARIAT has emerged as one of the alternatives to oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF). Our aim was to study long-term outcomes in patients undergoing LARIAT procedure. METHODS: We analyzed patients screened for LARIAT device in four centers between December 2009 and June 2012. Out of these, patients who didn't undergo LAAC with the LARIAT device due to unfavorable LAA morphology and other preprocedural contraindications were included in control group. We analyzed thromboembolism, bleeding events, and mortality between LAA and control group. RESULTS: About 153 patients were screened. Out of these, 108 (70.6%) patients underwent LARIAT placement (LAA arm) and 45 (29.4%) excluded patients were included in control arm. There were no differences in CHADS2 and CHA2 DS2 -VASc score. Mean HAS-BLED score was significantly higher in the LARIAT group (3.5 ± 1.06 vs 3.09 ± 1.22, P = .04). Mean follow-up time (in years) was 6.56 ± 0.84 in LAA and 6.5 ± 1.26 in control arm. During follow-up period, the LARIAT group was associated with significantly less thromboembolic events (1.9% vs 24%, P < .001), bleeding events (9.2% vs 24.4%, P = .03), and mortality (5.6% vs 20%, P = .01) as compared with the control group. CONCLUSIONS: Long-term data from routine clinical practice from our study suggests that LAA exclusion with LARIAT device is an effective treatment in management of nonvalvular AF patients with high risk of stroke, bleeding, and mortality. Further randomized trials, such as aMAZE, will provide more insight in this expanding field.

Ten-year follow-up after combined coronary artery bypass grafting and transmyocardial laser revascularization in patients with disseminated coronary atherosclerosis.

Coronary artery disease involving heavily calcified lesions has been associated with worse short- and long-term outcomes including increased mortality. This paper aims to evaluate long-term survival benefit when CABG + transmyocardial laser revascularization (TMLR) are performed on the hearts of patients with disseminated coronary atherosclerosis (DCA). This novel retrospective study was conducted between 1997 and 2002 and followed 86 patients with ischemic heart disease and severe DCA who underwent TMLR using a Holmium:YAG laser and/or CABG. There were 46 patients who had CABG plus TMLR on at least one heart wall ("combined therapy group") and 40 patients who had CABG or TMLR separately on at least one heart wall ("single therapy group"). For the whole group, actuarial survival at 10 years was 78.3% in the combined group compared to 72.5% in the single therapy group (p = 0.535). Ten-year survival in the combined vs. single therapy group for the anterior heart walls was 100 vs. 72.2% (p = 0.027). For the lateral and posterior heart walls were 73.7 vs. 73.3% (p = 0.97) and 84.2 vs. 72% (p = 0.27), respectively. Kaplan-Meier survival analysis showed benefit only for the anterior heart wall (F Cox test, p = 0.103). Single therapy procedures on all heart walls (odds ratio 1.736, p = 0.264) or on the anterior heart wall only (odds ratio 3.286, p = 0.279) were found to be predictors of 10-year late mortality. Combined therapy (TMLR + CABG) provides benefit for perioperative mortality and long-term survival only when provided on the anterior heart wall. For patients with disseminated coronary atherosclerosis, cardiac mortality was found to be increased when followed up 6 years later, regardless of the therapy applied.

Response Time and Effectiveness in Elite Greco-Roman Wrestlers Under Simulated Fight Conditions.

Gierczuk, D, Bujak, Z, Cieslinski, I, Lyakh, V, and Sadowski, J. Response time and effectiveness in elite Greco-Roman wrestlers under simulated fight conditions. J Strength Cond Res 32(12): 3442-3449, 2018-The purpose of the study was to determine changes in response time and its correlations with tactical and technical actions performed by Greco-Roman wrestlers in a fight. Twenty wrestlers aged 19-25 (21.4 (Equation is included in full-text article.)1.8) years were divided into 2 groups, i.e., finalists of Polish Senior Championships (winners of 1st and 2nd places) and wrestlers who won 3rd-6th places in those competitions. The subjects from 1 group were individually paired with the wrestlers from the other group according to the same weight class. Response time before a fight and during the intervals between the 3 rounds was assessed. Batak Lite (test IV) was used in the study. The Polar M400 watch was used to register heart rate. Response time changed during a fight. The finalists showed significantly quicker reaction and performed a higher number of technical and tactical actions. The differences grew in the course of a fight, and the largest ones were observed during the third round. The strongest correlations were noted between response time and the number of technical and tactical actions performed during the third round (r = 0.77, p < 0.001). Response time is a significant determinant of wrestlers' results, which can be observed at submaximal intensity of the effort (176-195 b·min) during a fight.

Transapical Beating-Heart Mitral Valve Repair With an Expanded Polytetrafluoroethylene Cordal Implantation Device: Initial Clinical Experience.

BACKGROUND: Degenerative mitral valve (MV) disease is a common cause of severe mitral regurgitation (MR) and accounts for the majority of MV operations. Conventional MV surgery requires cardiopulmonary bypass, aortic cross-clamping, cardioplegia, and a thoracotomy or sternotomy and, therefore, is associated with significant disability, risks, and unpredictable rates of MV repair. Transesophageal echocardiography-guided beating-heart MV repair with expanded polytetrafluoroethylene cordal insertion has the potential to significantly reduce surgical morbidity. We report the first-in-human clinical experience with a novel preformed expanded polytetrafluoroethylene knot implantation device (Harpoon TSD-5) designed to treat degenerative MR. METHODS: Through a small left thoracotomy, the device was inserted into the heart and guided by transesophageal echocardiography to the ventricular surface of the prolapsed leaflet. Multiple expanded polytetrafluoroethylene cords were anchored in the leaflet and then adjusted to the correct length to restore MV leaflet coaptation and secured at the epicardium. RESULTS: Eleven patients with posterior leaflet prolapse and severe MR, with mean±SD age of 65±13 years and mean ejection fraction of 69±7%, were treated with 100% procedural success. Immediate postprocedural mean MR grade was trace. At 1 month, the mean MR grade was mild with significant decreases in end-diastolic volume (139 to 107 mL; P=0.03) and left atrial volume (118 to 85 mL; P=0.04). CONCLUSIONS: A novel device used for beating-heart image-guided MV repair demonstrates a significant reduction in MR with favorable left ventricular and left atrial reverse remodeling. This approach has the potential to decrease invasiveness and surgical morbidity. Further follow-up is necessary to assess long-term efficacy. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02432196.

Direct Measurement of the Tunable Electronic Structure of Bilayer MoS2 by Interlayer Twist.

Using angle-resolved photoemission on micrometer-scale sample areas, we directly measure the interlayer twist angle-dependent electronic band structure of bilayer molybdenum-disulfide (MoS2). Our measurements, performed on arbitrarily stacked bilayer MoS2 flakes prepared by chemical vapor deposition, provide direct evidence for a downshift of the quasiparticle energy of the valence band at the Brillouin zone center (Γ̅ point) with the interlayer twist angle, up to a maximum of 120 meV at a twist angle of ∼40°. Our direct measurements of the valence band structure enable the extraction of the hole effective mass as a function of the interlayer twist angle. While our results at Γ̅ agree with recently published photoluminescence data, our measurements of the quasiparticle spectrum over the full 2D Brillouin zone reveal a richer and more complicated change in the electronic structure than previously theoretically predicted. The electronic structure measurements reported here, including the evolution of the effective mass with twist-angle, provide new insight into the physics of twisted transition-metal dichalcogenide bilayers and serve as a guide for the practical design of MoS2 optoelectronic and spin-/valley-tronic devices.

Long-term follow-up after Holmium:YAG laser revascularization combined with autologous bone marrow derived stem cells implantation.

Background: Coronary artery disease is a major cause of death worldwide. Despite different standard revascularization options, significant number of patients remains not suitable for any treatment. The aim of the study was to evaluate long-term outcome of patients with diffuse coronary artery disease, treated with autologous stem cells injections combined with transmyocardial laser revascularization. Material and Methods: 9 patients underwent Holmium:YAG laser revascularization and autologous bone marrow derived stem cells implantation between 2007 and 2009 in the Department of Cardiovascular Surgery and Transplantology, John Paul II Hospital, Kraków and were subsequently followed up in 2015. Results: The mean follow-up period was 73 months. The mean CCS class significantly improved (1.4±0.5 vs 3.3±1.0; p<0.001) and cardiac related hospitalizations significantly decreased (1.1±0.8 vs 3.1±2.1; p<0.001). One death due to heart failure was observed. The mean LVEF increased from 38% to 42% (p>0.05). Conclusions: Clinical status improvement was observed with low mortality rate in the long-term follow-up. No new regional wall motion abnormalities were observed, and the increase of global ejection fraction was noted.

Assessment of quality of life in patients after surgical and transcatheter aortic valve replacement.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) and minimally invasive aortic valve replacement (mini-thoracotomy, mini-sternotomy, MIAVR) have become an appealing alternative to conventional surgical (SAVR) treatment of severe aortic stenosis (AS) in high-risk patients. BACKGROUND: Aim of the study was to evaluate the quality of life (QoL) in patients with AS and treated with transfemoral TAVI, SAVR, mini-thoracotomy and mini-sternotomy. METHODS: One hundred and seventy-three patients with symptomatic AS were enrolled in 2011-2013. TAVI group consisted of 39 patients (22.5%), mini-sternotomy was performed in 44 patients (25.5%), mini-thoracotomy in 50 (29%), and AVR in 40 patients (23%). QoL was assessed perioperatively, 12 and 24 months after aortic valve replacement (AVR) by Minnesota Living with Heart Failure Questionnaire (MLHFQ) and EQ-5D-3L. RESULTS: Median follow-up was 583.5 (IQR: 298-736) days. Improvement of health status after procedure in comparison with pre-operative period was significantly more often reported after TAVI in perioperative period (90.3%; P = 0.004) and 12 months after procedure (100%, P = 0.02). Global MLHFQ, physical and emotional dimension score at 30-day from AVR presented significant improvement after TAVI in comparison with surgical methods (respectively: 8.3(±8.6), P = 0.003; 4.1(±5.9), P = 0.01; 1.5(±2.6), P = 0.005). Total MLHFQ score was significantly lower (better outcome) in TAVI patients 1 year after procedure (4.8(±6.8), P = 0.004), no differences in somatic and emotional component were found. No differences were found in MLHFQ score 24 months after AVR. Data from EQ-D5-3L questionnaire demonstrated significant improvement of QoL at 30-day follow-up after TAVI in comparison with surgical methods (1.2(±1.7), P = 0.0008). CONCLUSIONS: TAVI improves QoL in perioperative and 12 months observation in comparison with mini-thoracotomy, mini-sternotomy and SAVR. Improvement in QoL was obtained in both generic and disease specific questionnaires. © 2016 Wiley Periodicals, Inc.

Fibrin structure in organized thrombotic material removed during pulmonary artery endarterectormy: the effect of vessel calibre.

Pulmonary endarterectomy (PEA) is a curative therapeutic approach in patients with chronic thromboembolic pulmonary hypertension (CTEPH). The location-dependent structural differences of thrombotic material found in pulmonary arteries in CTEPH are poorly investigated. We present the case of a 47-year-old woman with antiphospholipid syndrome, diabetes mellitus and abnormal fibrin phenotype, who underwent PEA for CTEPH. Intravascular material removed bilaterally during PEA (from lobar, segmental and sub-segmental arteries) has been studied using light and scanning electron microscopy (SEM). Light microscopy showed tighter fibrous network in the portions of intraluminal thrombotic material facing the vessel wall, which contained collagen and fibrin fibers, and abundant cells. Cells, evaluated by immunostaining, were present in the whole removed material. Tissue factor expression was also observed with the highest values in the portions of intravascular material facing the vessel wall. In the main pulmonary arteries, SEM images revealed thick fibers of fibrous proteins loosly meshed and few erythrocytes and platelets between them (both dysmorphic "wedged" and fresh cells were present). In the fibrotic layers, containing mainly collagen and fibrin, removed from the lobar/segmental pulmonary arteries we found a stepwise increase in fiber density with decreasing vessel calibre, followed by denser fibrous networks composed of thinner fibers. Elastic fibers in the lobar and segmental arteries were aligned along the blood flow vector. These findings demonstrate differences in the structure of endarterectomized PEA material dependent on the vessel calibre and might contribute to understanding of CTEPH pathophysiology.

Advanced Integrity Preservation Technology Reduces Bioprosthesis Calcification While Preserving Performance and Safety.

BACKGROUND AND AIM OF THE STUDY: Structural valve deterioration (SVD) is the leading failure mode of bioprosthetic heart valves. The Edwards Integrity-Preservation (EIP™) technology was developed to permanently block tissue calcium-binding sites and allow for non-aqueous valve storage. The study aim was to evaluate the efficacy of tissue anti-calcification, valve performance, durability, and safety. METHODS: Bovine pericardial tissue with EIP technology was compared to industry-standard Carpentier-Edwards ThermaFix® and Xenologix® treatments. Anti-calcification efficacy was evaluated in the rabbit model at 60 days, and tissue calcium contents were quantified using atomic absorption spectrophotometry. Valve performance was assessed using an in-vivo 20-week chronic ovine model, and in-vitro hydrodynamic testing (effective orifice area and regurgitation). Valve durability was evaluated by accelerated wear testing at 200 million cycles (equivalent to five years). Valve safety was characterized by biocompatibility testing as per ISO requirements. RESULTS: Calcification results showed that the control and EIP technology tissues had a mean Ca content of 104.95 ± 102.69 and 21.20 ± 38.46 µg/mg dry tissue, respectively; the median Ca contents were 81.15 and 0.43 µg/mg dry tissue, respectively (p < 0.0001). The overall valve performance in the sheep was comparable between control and test. In-vitro hydrodynamics and durability were similar between groups, across all sizes, and met ISO requirements. EIP technology was shown to be biocompatible for use as an implantable device. CONCLUSION: Preclinical in-vitro and in-vivo evaluations showed that EIP technology significantly reduced tissue calcification and preserved valve performance and safety compared to current standards of care. Future studies will determine whether these findings can be replicated in humans.