Crescent Shape Research Articles

Modulation of Orbital-Angular-Momentum Symmetry of Nondiffractive Acoustic Vortex Beams and Realization Using a Metasurface

Orbital angular momentum (OAM) carried by acoustic vortex attracts extensive research interests due to the possible application such as acoustic tweezer and communications. The OAM in the conventional symmetric acoustic vortex is generally determined by topological charge l. Here, we provide the beam symmetry as an alternative factor to manipulate the OAM beyond the topological charge. We propose a nondiffractive asymmetric acoustic vortex beam, which can be generated by an acoustic metasurface and modulate the OAM to arbitrary values. Rather than the radially symmetric distribution, the intensity of the asymmetric acoustic vortex is characterized with a crescent shape controlled by the asymmetry parameter $\ensuremath{\alpha}$. The ratio between axial OAM and sound energy on the transverse plane depends on the asymmetry parameter and thus is not quantized by the ratio of topological charge l to wave angular frequency $\ensuremath{\omega}$ as in conventional vortex beam. Moreover, we present the realization of the proposed vortex beam by designed metasurface, and reveal the nondiffractive nature of the asymmetric acoustic vortex beam. Our work expands the family of acoustic vortex and demonstrates an alternative route to control acoustic OAM.

Finite element modeling of proximal femur with quantifiable weight-bearing area in standing position

BackgroundThe positional distribution and size of the weight-bearing area of the femoral head in the standing position as well as the direct active surface of joint force can directly affect the result of finite element (FE) stress analysis. However, the division of this area was vague, imprecise, and un-individualized in most studies related to separate FE models of the femur. The purpose of this study was to quantify the positional distribution and size of the weight-bearing area of the femoral head in standing position by a set of simple methods, to realize individualized reconstruction of the proximal femur FE model.MethodsFive adult volunteers were recruited for an X-ray and CT examination in the same simulated bipedal standing position with a specialized patented device. We extracted these image data, calculated the 2D weight-bearing area on the X-ray image, reconstructed the 3D model of the proximal femur based on CT data, and registered them to realize the 2D weight-bearing area to 3D transformation as the quantified weight-bearing surface. One of the 3D models of the proximal femur was randomly selected for finite element analysis (FEA), and we defined three different loading surfaces and compared their FEA results.ResultsA total of 10 weight-bearing surfaces in 5 volunteers were constructed, and they were mainly distributed on the dome and anterolateral of the femoral head with a crescent shape, in the range of 1218.63–1,871.06 mm2. The results of FEA showed that stress magnitude and distribution in proximal femur FE models among three different loading conditions had significant differences, and the loading case with the quantized weight-bearing area was more in accordance with the physical phenomenon of the hip.ConclusionThis study confirmed an effective FE modeling method of the proximal femur, which can quantify the weight-bearing area to define a more reasonable load surface setting without increasing the actual modeling difficulty.

Dinamika podvodnogo vala peschanogo berega pod vozdeystviyem shtormovogo volneniya po dannym monitoringovykh nablyudeniy

Purpose. Morphodynamic system of the accumulative sandy coast can include one or more underwater bars. Position and shape of the underwater bar can reflect both seasonal changes of the coastal profile and its unidirectional movements landward and seaward. Determination of the character of the underwater bar movement under the influence of various wave conditions permits to reveal common factors of the coastal deposit multidirectional transport along the coast profile. Methods and Results . The results of field observations of morphodynamics of a section of the Baltic Spit sandy coast (600 m length) were analyzed. From May to November 2019, a series of measurements of the coastal zone relief were conducted. The obtained data were analyzed along with the wave regime parameters (reanalysis ERA5 data was used). The coastal profile of the area under study is complicated by the external underwater bar with its crest located at the depth 2.65 m, and by the internal one of a crescent shape. Conclusions . Analysis of displacement of the external underwater bar from May to November showed that this form was of a morphodynamics two-dimensional character, i.e. it possessed the same morphometric characteristics along the coast. It was revealed that the underwater bar crest was located at the depths close to those of wave breaking during the most recent relatively strong and sustainable storm. Based on this concept as well as on the available literature data on the relationship between a wave height and dynamics of an underwater bar crest, described is the landward displacement (recorded during the observation period) of the external underwater bar. Due to the field data, it was shown that the underwater bar morphodynamics was effected both by duration of individual waves and by difference between the wave parameters of a sequence of storm events.

Dynamics of Underwater Bar of Sandy Coast under the Influence of Wave Action According to the Monitoring Observations

Purpose. Morphodynamic system of the accumulative sandy coast can include one or more underwater bars. Position and shape of the underwater bar can reflect both seasonal changes of the coastal profile and its unidirectional movements landward and seaward. Determination of the character of the underwater bar movement under the influence of various wave conditions permits to reveal common factors of the coastal deposit multidirectional transport along the coast profile. Methods and Results. The results of field observations of morphodynamics of a section of the Baltic Spit sandy coast (600 m length) were analyzed. From May to November 2019, a series of measurements of the coastal zone relief were conducted. The obtained data were analyzed along with the wave regime parameters (reanalysis ERA5 data was used). The coastal profile of the area under study is complicated by the external underwater bar with its crest located at the depth 2.65 m, and by the internal one of a crescent shape. Conclusions. Analysis of displacement of the external underwater bar from May to November showed that this form was of a morphodynamics two-dimensional character, i.e. it possessed the same morphometric characteristics along the coast. It was revealed that the underwater bar crest was located at the depths close to those of wave breaking during the most recent relatively strong and sustainable storm. Based on this concept as well as on the available literature data on the relationship between a wave height and dynamics of an underwater bar crest, described is the landward displacement (recorded during the observation period) of the external underwater bar. Due to the field data, it was shown that the underwater bar morphodynamics was effected both by duration of individual waves and by difference between the wave parameters of a sequence of storm events.

Ancient Martian Aeolian Sand Dune Deposits Recorded in the Stratigraphy of Valles Marineris and Implications for Past Climates

AbstractAeolian sediment transport, deposition, and erosion have been ongoing throughout Mars's history. This record of widespread aeolian processes is preserved in landforms and geologic units that retain important clues about past environmental conditions including wind patterns. In this study we describe landforms within Melas Chasma, Valles Marineris, that occur in distinct groups with linear to crescentic shapes, arranged with a characteristic wavelength; some possess slope profiles analogous to modern sand dunes yet show evidence for lithification. Based on the features' dimensions, asymmetry, and spatial patterns relative to modern equivalents, we interpret these landforms to be two classes of aeolian bedforms: decameter‐scale megaripples and sand dunes. The presence of superposed erosional features and depositional units indicates that these landforms were cemented and likely ancient. Melas paleodunes are found atop Hesperian‐aged layered deposits, but we estimate them to be younger, likely lithified in the Amazonian period. Although a range of degradation was observed, some paleodunes are >10 m tall and maintain steep lee sides (>25°), an uncommon scenario for terrestrial examples as other geologic processes lead to dune obliteration. The preserved paleobedform geometries are largely consistent with those of modern aeolian indicators, suggesting no major shifts in wind regime or contributing boundary conditions. Finally, we propose that their appearance and context require sequential periods of dune migration, stabilization following catastrophic burial, cementation, differential erosion, exposure, and burial. The presence of wholly preserved duneforms appears to be more common on Mars compared to the Earth and may signal something important about Martian landscape evolution.

Wide-angle metamaterial absorber with highly insensitive absorption for TE and TM modes

Being incident and polarization angle insensitive are crucial characteristics of metamaterial perfect absorbers due to the variety of incident signals. In the case of incident angles insensitivity, facing transverse electric (TE) and transverse magnetic (TM) waves affect the absorption ratio significantly. In this scientific report, a crescent shape resonator has been introduced that provides over 99% absorption ratio for all polarization angles, as well as 70% and 93% efficiencies for different incident angles up to theta =80^{circ } for TE and TM polarized waves, respectively. Moreover, the insensitivity for TE and TM modes can be adjusted due to the semi-symmetric structure. By adjusting the structure parameters, the absorption ratio for TE and TM waves at theta =80^{circ } has been increased to 83% and 97%, respectively. This structure has been designed to operate at 5 GHz spectrum to absorb undesired signals generated due to the growing adoption of Wi-Fi networks. Finally, the proposed absorber has been fabricated in a 20 times 20 array structure on FR-4 substrate. Strong correlation between measurement and simulation results validates the design procedure.

Pods as sails but not as boats: dispersal ecology of a habitat-restricted desert milkvetch.

Adaptive seed dispersal mechanisms are fundamental to plant fitness, but dispersal advantage is scale-dependent. We tested the hypothesis that informed dispersal in response to an environmental cue enables dispersal by wind on a local scale for Astragalus holmgreniorum, a desert species restricted to swales and wash skirts with overland flow, but prevents longer-distance dispersal by water into unfavorable wash habitats. Pod biomechanics in A. holmgreniorum lead to major shape modifications with changes in moisture content. We performed laboratory experiments to examine the interaction of pod shape with wind and water, and conducted field experiments in A. holmgreniorum habitat evaluating the roles of wind, water, and seed predators on dispersal. Dry pods exhibit a flattened crescent shape with partial dehiscence that facilitated wind dispersal by ground tumbling and seed scattering in laboratory experiments. Rain simulation experiments showed that even small precipitation events returned wetted pods to their cylindrical shape and opened the dorsal suture, exposing the seeds. In the field experiments, dry pods were moved locally by wind, whereas rain caused pod opening and washing out of seeds in place. Seed predators had minimal effect on pod movement. Astragalus holmgreniorum exhibits pod structural remodeling in response to environmental change in a striking and novel demonstration of informed dispersal. Wind-driven movement of dry pods facilitates local seed dispersal, but rain causes pods to open and release seeds, ensuring that they are not transported out of suitable habitats and into active washes where they would be lost from the seed bank.

A minimal mechanosensing model predicts keratocyte evolution on flexible substrates.

A mathematical model is proposed for shape evolution and locomotion of fish epidermal keratocytes on elastic substrates. The model is based on mechanosensing concepts: cells apply contractile forces onto the elastic substrate, while cell shape evolution depends locally on the substrate stress generated by themselves or external mechanical stimuli acting on the substrate. We use the level set method to study the behaviour of the model numerically, and predict a number of distinct phenomena observed in experiments, such as (i) symmetry breaking from the stationary centrosymmetric to the well-known steadily propagating crescent shape, (ii) asymmetric bipedal oscillations and travelling waves in the lamellipodium leading edge, (iii) response to remote mechanical stress externally applied to the substrate (tensotaxis) and (iv) changing direction of motion towards an interface with a rigid substrate (durotaxis).

Demographic profile, clinical features, and outcome of peripapillary subretinal hemorrhage: an observational study

BackgroundTo evaluate the etiology, demographic profile, clinical features, and outcomes in patients with peripapillary subretinal hemorrhage (PSH).MethodsThirty-eight eyes of 37 consecutive patients with PSH were enrolled in this prospective observational study over 4 years; all were followed for 2 years. The main outcome measures were demographic profile, possible etiology, clinical features, outcome, and prognosis.ResultsSixty-eight percent (26/38) of eyes were in female patients; the mean patient age was 20 years. Only 1 patient (1/37) showed bilateral involvement. All patients experienced acute onset of PSH. All eyes were myopic and their best-corrected visual acuities ranged from 20/1000 to 20/12.5. The fundus features of affected eyes were classified into 3 groups: (1) PSH alone (4/38 eyes, 10.5%); (2) PSH with intrapapillary hemorrhage (17/38 eyes, 44.7%); (3) PSH with intrapapillary and vitreous hemorrhage (17/38 eyes, 44.7%). PSH occurred in nasal edges of optic discs with a crescent shape and dull-red color. All affected optic discs were small and crowded, exhibiting variable degrees of tilting. The cup of affected optic discs was narrower and deeper than that of normal control discs. Other ancillary tests provided no additional value. After a mean follow-up of 2.85 months, the hemorrhages resolved spontaneously without sequelae. Recurrence of disease was not observed in any patients.ConclusionsPSH is common in myopic eyes with tilted optic discs. We suspect that these hemorrhages occurred as a result of abrupt movement acting on a morphologically vulnerable optic disc.

Stereoselective gridization and polygridization with centrosymmetric molecular packing

The gridarenes, with well-defined edges and vertices, represent versatile nanoscale building blocks for the installation of frameworks and architectures but suffer from difficulty in stereoselective control during their synthesis. Here we report a diastereoselective gridization of superelectrophilic diazafluorene-containing substrates (AmBn) with crescent shapes into Drawing Hands grids (DHGs). The meso-selectivity reaches 75.6% diastereomeric excess (de) during the gridization of A1B1-type substrates and maintains ~80% de during the polygridization of A2B2-type monomers. Such stereocontrol originates from the centrosymmetric molecular packing of two charge-delocalized superelectrophiles with synergistically π–π stacking attractions and coulombic repulsions. As meso-stereoregular structures show 20∼30 nm in length, the rigid ring/chain-alternating polygrids have a Mark–Houwink exponent of 1.651 and a molecular weight (M) dependence of the hydrodynamic radius Rh ∼ M1.13. Via the simulation of chain collapse, meso-configured polygridarenes still adopt rod-like conformations that facilitate the high rigidity of organic nanopolymers, distinguished from toroid backbones of rac-type polygrids.

Micro pave setting for the triple moon goddess jewelry set designs

Generally, jewelry is made from gold and silver with the addition of the jewel itself. Frack & Co usually use a diamond with level F color and clarity of DVS (Very Slight Inclusions). Thus jewelry has purposes as beautify of its user, it has another purpose which is as the prestige of the lifestyle of the user. In this research analyzed trends, color, and price. Based on the market-targeted analysis, jewelry design is produced based on two classes of price, the middle-class user (approx. 15-45 million) and the high-class user (45-85 million). The Triple Moon Goddess jewelry set design is using white gold and rose gold 18K and diamond with 0.0010C-0.042C by using the technique of Micro Pave setting and round ash facets, so the diamond looks brighter and bigger. The concept design is based on 3 moon symbols with a crescent shape, full moon, and crescent moon sequence. It is referring to the symbol of life birth, maturity, and wisdom. The jewelry set consists of a woman ring, a bracelet, and a pair of earrings. The production process uses the wax tree and gold casting process.

Traction Forces Control Cell-Edge Dynamics and Mediate Distance Sensitivity during Cell Polarization.

Traction forces are generated by cellular actin-myosin system and transmitted to the environment through adhesions. They are believed to drive cell motion, shape changes, and extracellular matrix remodeling [1-3]. However, most of the traction force analysis has been performed on stationary cells, investigating forces at the level of individual focal adhesions or linking them to static cell parameters, such as area and edge curvature [4-10]. It is not well understood how traction forces are related to shape changes and motion, e.g., forces were reported to either increase or drop prior to cell retraction [11-15]. Here, we analyze the dynamics of traction forces during the protrusion-retraction cycle of polarizing fish epidermal keratocytes and find that forces fluctuate together with the cycle, increasing during protrusion and reaching maximum at the beginning of retraction. We relate force dynamics to the recently discovered phenomenological rule [16] that governs cell-edge behavior during keratocyte polarization: both traction forces and probability of switch from protrusion to retraction increase with the distance from the cell center. Diminishing forces with cell contractility inhibitor leads to decreased edge fluctuations and abnormal polarization, although externally applied force can induce protrusion-retraction switch. These results suggest that forces mediate distance sensitivity of the edge dynamics and organize cell-edge behavior, leading to spontaneous polarization. Actin flow rate did not exhibit the same distance dependence as traction stress, arguing against its role in organizing edge dynamics. Finally, using a simple model of actin-myosin network, we show that force-distance relationship might be an emergent feature of such networks.

Deep Learning Models for Classification of Red Blood Cells in Microscopy Images to Aid in Sickle Cell Anemia Diagnosis

Sickle cell anemia, which is also called sickle cell disease (SCD), is a hematological disorder that causes occlusion in blood vessels, leading to hurtful episodes and even death. The key function of red blood cells (erythrocytes) is to supply all the parts of the human body with oxygen. Red blood cells (RBCs) form a crescent or sickle shape when sickle cell anemia affects them. This abnormal shape makes it difficult for sickle cells to move through the bloodstream, hence decreasing the oxygen flow. The precise classification of RBCs is the first step toward accurate diagnosis, which aids in evaluating the danger level of sickle cell anemia. The manual classification methods of erythrocytes require immense time, and it is possible that errors may be made throughout the classification stage. Traditional computer-aided techniques, which have been employed for erythrocyte classification, are based on handcrafted features techniques, and their performance relies on the selected features. They also are very sensitive to different sizes, colors, and complex shapes. However, microscopy images of erythrocytes are very complex in shape with different sizes. To this end, this research proposes lightweight deep learning models that classify the erythrocytes into three classes: circular (normal), elongated (sickle cells), and other blood content. These models are different in the number of layers and learnable filters. The available datasets of red blood cells with sickle cell disease are very small for training deep learning models. Therefore, addressing the lack of training data is the main aim of this paper. To tackle this issue and optimize the performance, the transfer learning technique is utilized. Transfer learning does not significantly affect performance on medical image tasks when the source domain is completely different from the target domain. In some cases, it can degrade the performance. Hence, we have applied the same domain transfer learning, unlike other methods that used the ImageNet dataset for transfer learning. To minimize the overfitting effect, we have utilized several data augmentation techniques. Our model obtained state-of-the-art performance and outperformed the latest methods by achieving an accuracy of 99.54% with our model and 99.98% with our model plus a multiclass SVM classifier on the erythrocytesIDB dataset and 98.87% on the collected dataset.

Traditional and Novel Imaging of Right Ventricular Function in Patients with Heart Failure and Reduced Ejection Fraction.

This review attempts to summarize the role of standard and advanced echocardiographic techniques together with CMR in the evaluation of the RV in HF, providing an outlook on the recent evidence. In the last decade, there has been growing interest in the study of the RV, and it is now widely established that RV function is a strong predictor of mortality, in several cardiovascular diseases, in particular in the setting of heart failure (HF). The evaluation of RV function might be particularly challenging, which justifies the necessity of multi-modality imaging. The echocardiographic assessment remains the mainstay technique even though it might be complex, due to RV crescent shape and its position in the chest, requiring both qualitative and quantitative parameters. Cardiac magnetic resonance (CMR) represents a complementary exam which is particularly useful when precise structural and functional assessment are needed, considering the most recently developed sequences. Despite the technological improvement attested over the last years, there is still no universally accepted parameter that univocally defines RV function, hence the necessity to evaluate several parameters, combining different imaging techniques.

A preliminary study on morphology and genesis of giant and mega pockmarks near Andu Seamount, Nansha Region (South China Sea)

Pockmarks consists of depressions on the seafloor and are often considered to originate from fluid escape activities. In this study, we report 125 pockmarks near the Andu Seamount in the southern margin of the South China Sea (SCS) and preliminarily investigate their genesis based on multi-beam bathymetry and multichannel seismic reflection data. Most of them are giant and mega pockmarks and display circular, elliptical, elongated, crescent, comet and irregular shapes on a plan-view. The mapped pockmarks cover a total surface of 291.354 km2. Most of them occur in strings or clusters, while some are isolated. The filled volume of pockmark is calculated for the first time in this region, which may have significant implications for sedimentary process. Beneath most of the pockmarks, high-angle faults, high-amplitude reflections, filled-up structures and other fluid escape features are imaged on seismic sections. The structural settings, especially the fault systems, may control the genesis and development of pockmarks in this area. We also speculate that seabed gradients may contribute to generation of crescent pockmarks. According to seismic sections, sediment types and morphological analysis, we finally proposed that the genesis of these pockmarks may mainly be triggered by gas escape activities in the study area. This work may have important implications for the gas exploration in the Nansha Region, southern South China Sea.

Micromorphology, pharmacognosy, and bio-elemental analysis of an important medicinal herb: Verbascum thapsus L.

The present study was conducted on characterization of morpho-anatomical, phytochemical, and bio-elemental analysis of root, stem, and leaf of Verbascum thapsus. Morphologically Verbascum is a biennial plant that flowers for a month and a half in mid- to late summer. Various organoleptic features of root, leaf, and stem were recorded. Anatomically the T. S of the root, stem, and leaf showed a typical dicot histological differentiation. Leaf possessed anomocytic stomata, crescent shape vascular bundles, and covered with long and stellate type trichomes while, stem contained collateral type of vascular bundles and a well-developed pith to store phytochemicals responsible for various pharmacological activities. The powder drug study through scanning electron microscopy revealed the presence of various types of tissues. Branched, tree like and stellate trichomes in root and leaf help in absorption and reduce loss of water. These anatomical features are responsible for the survival of the plant as biennial. Four macro elements (Na, K, Ca, and Mg) and seven microelements (Cr, Cu, Fe, Mn, Ni, Zn, and Cd) and their concentrations in ppm were also studied using Atomic Absorption Spectroscopy. Phytochemical screening of methanolic extract showed existence of various secondary metabolites, while mucilage and anthraquinones was not detected. The present study helps to understand the taxonomic identification of the plant based on morpho-anatomical features and throws the attention of the researchers to carry out the work for developing its various formulations, which can ultimately be beneficial for the human beings as well as animals.

Design of Crescent Shaped 64-Elements Flexible Patch Antenna Array for the Application of Uterine Tumour Detection

In this paper, a crescent shape 64 (8 × 8) elements microstrip patch array, using rubber substrate is designed and simulated to function at 4 GHz for the application of uterine tumour detection. A comparison using various combinations of antenna array elements is also presented. The centre-to-centre patch element distance is kept 0.5λ (λ = guided wavelength) for the antenna array to control mutual coupling. Electromagnetic simulator Ansoft HFSS 13 is used for the simulation. Characteristic analysis e.g. return loss(RL), radiation pattern of patch antenna array have been investigated. This antenna is placed on human uterine phantom model and simulated to detect uterine tumour. 64-elements antenna array has been fabricated also. In this paper, RL of -26.8384 dB & antenna gain of 21.0271 have been achieved for the proposed array. Human uterine phantom model is designed and simulated by CST Studio Suite 2019.

Shape evolution of numerically obtained subaqueous barchan dunes.

In the realm of granular bedforms, barchan dunes are strong attractors that can be found in rivers, terrestrial deserts, and other planetary environments. These bedforms are characterized by a crescentic shape, which, although robust, presents different scales according to the environment they are in, their length scale varying from the decimeter under water to the kilometer on Mars. In addition to the scales of bedforms, the transport of grains presents significant differences according to the nature of the entraining fluid, so that the growth of barchans is still not fully understood. Given the smaller length and time scales of the aquatic case, subaqueous barchans are the ideal object to study the growth of barchan dunes. In the present paper, we reproduce numerically the experiments of Alvarez and Franklin [Phys. Rev. E 96, 062906 (2017)2470-004510.1103/PhysRevE.96.062906; Phys. Rev. Lett. 121, 164503 (2018)PRLTAO0031-900710.1103/PhysRevLett.121.164503] on the shape evolution of barchans from their initiation until they have reached a stable shape. We computed the bed evolution by using the computational fluid dynamics-discrete element method, where we coupled the discrete element method with large eddy simulation for the same initial and boundary conditions of experiments, performed in a closed-conduit channel where initially conical heaps evolved to single barchans under the action of a water flow in a turbulent regime. Our simulations captured well the evolution of the initial pile toward a barchan dune in both the bedform and grain scales, with the same characteristic time and lengths observed in experiments. In addition, we obtained the local granular flux and the resultant force acting on each grain, the latter not yet previously measured nor computed. This shows that the present method is appropriate for numerical computations of bedforms, opening new possibilities for accessing data that are not available from current experiments.

Experimental study on the stable morphology and self-attraction effect of subaqueous barchan dunes

The evolutionary process of isolated dunes under the action of a unidirectional steady water flow is recorded from a bottom-up visual angle by optical synchronization imaging measurements. The morphological characteristics of dunes formed from different initial sand pile configurations are analyzed by an image-processing method. Results show that the trend of reproducing the crescent shape of the dune is shown in all sand piles, which is independent of the initial configuration. The triangular initial sand pile is found to be the first to stabilize to a crescent shape, whereas the square initial sand pile takes the longest time to form a stable crescent shape. This finding is essentially due to the shape effect of the triangle, which effectively reduces the amount of transverse moving sand particles. Based on the aspect ratio of the barchan dune that is stable at approximately 1, we determine that the evolution time required for the final stability of barchan dunes reproduced from different initial sand piles is approximately 200 s within the restriction of the present closed-water-tunnel experimental condition. Moreover, a dimensionless comparison of the profile curves of barchan dunes’ stable morphologies reveals a “streamwise–spanwise” dimension of the dune, which essentially synthesizes characteristic information about windward face and two horns. This “streamwise–spanwise” dimension ultimately presents the self-attraction effect of the crescent shape.

P1760 Cardiac prognosis of patients with subaortic membrane according to their morphology

Abstract INTRODUCTION Subaortic membrane is an entity which evolves during adulthood and can associate cardiac complications. Different morphologies have been described, although it is unknown if their prognosis varies according to these patterns. The aim of this study was to evaluate the cardiac prognosis of patients with subaortic membrane according to their morphological characteristics in adulthood. METHODS Forty-five patients diagnosed with subaortic membrane by imaging techniques were consecutively included (March 1999-August 2018). Three morphologies were described: fibromuscular ridge (FR), crescent-shaped (CS) and filamentous-shaped (FS). Cardiac complications were defined as mortality due to heart failure and/or necessity of aortic valve surgery and/or membrane resection. RESULTS Twenty-six cases (58%) had FR, 16 (35%) had CS and 3 (7%) presented FS (7%) (Fig.1). No differences were found in basal clinical parameters between groups. FR type was associated with the presence of dynamic gradient in baseline study (27% vs 0%, p = 0.014), but there were no differences in left ventricular ejection fraction (68 ± 8% vs 64 ± 8%; p = 0.092), nor in maximum thickness of basal interventricular septum (12.1 ± 3.9mm vs 11.7 ± 4.1mm, p = 0.699), nor in the presence of moderate/severe aortic stenosis (15% vs 11%, p > 0.999) with the other morphologies. During follow-up (mean ± SD= 5.8 ± 4.4years) 15 (33%) patients presented cardiac complications (2 deaths due to heart failure and 12 valvular interventions and/or membrane resection). FR type patients presented a higher cardiac complication rate (50% vs 11%, p = 0.006) and greater necessity of open-heart surgery (46% vs 11%, p = 0.011) than the other groups during follow-up. CONCLUSIONS FR type is associated with a higher rate of cardiac complications during follow-up than other subaortic membrane morphologies. Dynamic gradient associated to this pattern could be the basis of a possible pathophysiological mechanism related to the worst prognosis of these patients. Figure 1. Different morphologies of subaortic membranes. (A) Fibromuscular ridge type; (B) Crescent-shaped type; (C) Filamentous-shaped type. aL: anterior leaflet of mitral valve ; Ao: aorta; LA: left atrium; LV: left ventricle; RV: right ventricle. Abstract P1760 Figure.