Project description:Active matter demonstrates complex spatiotemporal self-organization not accessible at equilibrium and the emergence of collective behavior. Fluids comprised of microscopic Quincke rollers represent a popular realization of synthetic active matter. Temporal activity modulations, realized by modulated external electric fields, represent an effective tool to expand the variety of accessible dynamic states in active ensembles. Here, we report on the emergence of shockwave patterns composed of coherently moving particles energized by a pulsed electric field. The shockwaves emerge spontaneously and move faster than the average particle speed. Combining experiments, theory, and simulations, we demonstrate that the shockwaves originate from intermittent spontaneous vortex cores due to a vortex meandering instability. They occur when the rollers' translational and rotational decoherence times, regulated by the electric pulse durations, become comparable. The phenomenon does not rely on the presence of confinement, and multiple shock waves continuously arise and vanish in the system.
Project description:ObjectiveAortic Dissection (AD) is one of the most fatal acute diseases in cardiovascular diseases, with rapid onset and progression and a high fatality rate. This study aims to investigate the clinical values of non-enhancement peripheral pulse-gating rapid magnetic resonance imaging in deterministic diagnosis of AD.MethodsAorta magnetic resonance imaging was performed in 21 healthy volunteers at a 1.5t MR scanner sequences including cardiac-gated and peripheral pulse-gated True-FISP and HASTE were carried out separately. Acquisition Time (TA), Signal to Noise Ratio (SNR), Contrast Noise Ratio (CNR), and entirety of vessel wall blood flow artifacts were measured and compared. A total of 56 AD cases were displayed by non-enhancement peripheral pulse-gating fast MR imaging, and the results were compared with pathological findings or CTA of the aorta. The dissection rupture, tear film, true and false lumen, thrombosis, hydropericardium, and the main branches of AD were evaluated respectively.ResultsThere were no significant differences in SNR, CNR, entirety of the vessel wall, and blood flow artifact between cardiac-gated and peripheral pulse-gated fast MR imaging. Non-enhancement pulse-gated fast scanning takes less TA time. By the pulse-gated non-enhancement fast MR imaging, the dissection rupture, tear film, true and false cavity, thrombosis, hydropericardium, and the main branches of aortic dissection were shown clearly. Multi-planar and multi-angle scans helped to show the extent of entrapment rupture, whereas partial complex tears or bi-directional tears were slightly less well visualized.ConclusionNon-enhancement peripheral pulse-gated rapid magnetic resonance imaging can be used for deterministic diagnosis of AD.
Project description:Spontaneous renal artery dissection (SRAD) is a rare entity causing muscle spasm due to acute low back pain, back pain, or flank pain symptoms or misleading clinical diagnosis such as renal colic. A 25-year-old Syrian male refugee presented to the emergency department with sudden onset of left-sided flank pain in the evening. Physical examination results were normal except left-sided costovertebral angle sensitivity. Abdominal, pelvic and thoracic contrast computed tomography angiography (CTA) was performed to evaluate aortic dissection, which was our urgent preliminary diagnosis. Left renal artery dissection was detected in CTA. The patient was treated with medical conservative treatment and spontaneous recovery was observed during the follow-up period. Early detection of SRAD in the emergency department can be difficult due to the fact that the clinical presentation is misleading.
Project description:Spontaneous aortic dissection in pregnancy is rare and life-threatening for both the mother and the fetus. It is commonly associated with connective tissue disorders or aortic valvular abnormalities. We describe a case of a hypertensive pregnant woman in whom a dilated ascending aorta was identified in a routine transthoracic echocardiogram. Careful interrogation of the ascending aorta, with the use of intravenous contrast, revealed the presence of a type A aortic dissection flap. The particulars of the case are presented and the literature regarding acute aortic dissection in pregnancy is reviewed. <Learning objective: Challenges in diagnosis of aortic dissection in pregnancy.>.
Project description:Aortic dissection (AD), a dangerous disease threatening to human beings, has a hidden onset and rapid progression and has few effective methods in its early diagnosis. At present, although CT angiography acts as the gold standard on AD diagnosis, it is so expensive and time-consuming that it can hardly offer practical help to patients. Meanwhile, the artificial intelligence technology may provide a cheap but effective approach to building an auxiliary diagnosis model for improving the early AD diagnosis rate by taking advantage of the data of the general conditions of AD patients, such as the data about the basic inspection information. Therefore, this study proposes to hybrid five types of machine learning operators into an integrated diagnosis model, as an auxiliary diagnostic approach, to cooperate with the AD-clinical analysis. To improve the diagnose accuracy, the participating rate of each operator in the proposed model may adjust adaptively according to the result of the data learning. After a set of experimental evaluations, the proposed model, acting as the preliminary AD-discriminant, has reached an accuracy of over 80%, which provides a promising instance for medical colleagues.
Project description:A patient presented with an intraluminal fibrous cord in the distal segment of ascending aorta. On axial images, the fibrous cord had the appearance of an aortic dissection flap. Observation of continuous images and multiplanar reconstruction were critical for differential diagnosis. Volume render images showed both ends of the fibrous cord had tentiform attachments to the aorta inner wall, which indicating a congenital aorta anomaly. One possible hypothesis for the congenital variation might be the fifth primitive aortic arches remnant.
Project description:We report a case of a type A aortic dissection with extension into the main pulmonary artery through a sinus of Valsalva fistula. Echocardiography and computed tomographic angiography of the chest were performed and bicuspid aortic valve, hemopericardium, and dilatation of the aortic root were found. A Stanford type A dissection was seen, extending to the distal transverse thoracic aorta, and there was a communication between the dissection at the left sinus of Valsalva and the main pulmonary artery, where a dissection flap was detected at computed tomographic angiography. This case report reviews the rare diagnosis of pulmonary artery dissection, multimodality imaging findings, and a brief review of etiology and management.
Project description:The purpose of the present study was to establish the accuracy of transthoracic echocardiography (TTE) in diagnosis of acute type A aortic dissection in comparison to computed tomography (CT), with reference to the intraoperative image.The retrospective analysis included 178 patients referred to the cardiac surgery unit in our center due to acute type A dissection between 01-01-2008 and 31-12-2013, who underwent both TTE and CT. Intraoperative image was considered as a reference.Statistical analysis did not show any significant differences between computed tomography and echocardiography in the detection of the proximal aortic dissection. In patients with aortic valve abnormalities, procedure of choice was replacement by a composite graft (77,59%), whereas patients with a normal image of aortic valve were more likely to have the valve sparing procedure (50,88%). The R-Spearman statistics shows a strong positive correlation between maximum diameter of ascending aorta measured by TTE and CT (cc 0.869) and TTE and intraoperative measurement (cc 0.844).Our data confirm that transthoracic echocardiography is a reliable method for diagnosis of proximal aortic dissection. TTE provides a reliable value of maximum diameter of the ascending aorta in comparison to both CT and direct intraoperative measurement. Moreover, transthoracic echocardiography gives the additional information that influences the operative technique of choice and identifies the high-risk patients (cardiac tamponade, severe aortic dilatation, severe aortic regurgitation). Our retrospective analysis confirms the pivotal role of TTE in the evaluation of the patients with suspected proximal aortic dissection in emergency room setting.
Project description:With the acceleration of population aging, the detection rate of aortic dissection has increased. The incidence rate of aortic dissection has increased year by year and has become a serious threat to human health. However, the current clinical treatment of aortic dissection is mainly limited to surgery (including intracavity), but the complexity of the disease and the high risk of surgery seriously affect the overall treatment effect of the disease. Therefore, an in-depth study of the pathogenesis of aortic dissection and the development of early diagnosis methods is not only expected to control the development of aortic dissection but also to improve the existing clinical treatment effect. Based on the bioinformatics analysis of the related mRNA sequence data of aortic dissection in GEO database, the gene expression regulatory network of aortic dissection was constructed. Through the screening of key node genes, the key factors (molecular markers) that may affect the occurrence of aortic dissection were obtained, and their functions were tested in human aortic smooth muscle cells (HAoSMC). Finally, it was concluded that SERPINE1 gene is a reliable molecular marker for the early diagnosis of aortic dissection.
Project description:BackgroundWorse outcomes have been reported for women with type A acute aortic dissection (TAAD). We sought to determine sex-specific operative approaches and outcomes for TAAD in the current era.MethodsThe Interventional Cohort (IVC) of the International Registry of Acute Aortic Dissection (IRAD) database was queried to explore sex differences in presentation, operative approach, and outcomes. Multivariable logistic regression was performed to identify adjusted outcomes in relation to sex.ResultsWomen constituted approximately one-third (34.3%) of the 2823 patients and were significantly older than men (65.4 vs 58.6 years, P < .001). Women were more likely to present with intramural hematoma, periaortic hematoma, or complete or partial false lumen thrombosis (all P < .05) and more commonly had hypotension or coma (P = .001). Men underwent a greater proportion of Bentall, complete arch, and elephant trunk procedures (all P < .01). In-hospital mortality during the study period was higher in women (16.7% vs 13.8%, P = .039). After adjustment, female sex trended towards higher in-hospital mortality overall (odds ratio, 1.40; P = .053) but not in the last decade of enrollment (odds ratio, 0.93; P = .807). Five-year mortality and reintervention rates were not significantly different between the sexes.ConclusionsIn-hospital mortality remains higher among women with TAAD but demonstrates improvement in the last decade. Significant differences in presentation were noted in women, including older age, distinct imaging findings, and greater evidence of malperfusion. Although no distinctions in 5-year mortality or reintervention were observed, a tailored surgical approach should be considered to reduce sex disparities in early mortality rates for TAAD.