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BACKGROUND: Single-stage type I hybrid total aortic arch repair is a surgical treatment for extensive aortic arch disease, but the clinical outcomes were distinguishing. The purposes of this study were to share our experience and evaluate the perioperative safety and long-term durability. METHODS: Thirty-six patients who underwent single-stage type I hybrid total aortic arch repair in Fuwai Hospital between January 2010 and June 2020 were respectively reviewed. Early primary endpoint was defined as early composite adverse events, including mortality, multiple organ dysfunction syndrome (MODS), unplanned reoperation, stroke, paraplegia, acute renal failure (ARF) necessitating continuous renal replacement therapy (CRRT), respiratory failure and stents related complications. Long-term endpoints included late mortality, late aortic related reintervention and late adverse aortic events. When evaluating the early- and long-term outcomes, all patients were stratified into two subgroups by age (65 years). RESULTS: All patients acquired technical success. Early composite adverse events rate was 11.1% (4/36), in-hospital mortality was 8.3% (3/36). Average follow-up period was 48.0±35.3 months. Overall survival rate was 83.3% and 51.9% at 5 and 10 years respectively. Late aortic related reintervention occurred at one (3.0%, 1/33) patient and this patient died after reintervention. Overall freedom from adverse aortic events was 79.2% and 47.5% at 5 and 10 years respectively. Significant difference was not observed between the elderly and young subgroups, no matter in early- and long-term outcomes. CONCLUSIONS: Single-stage type I hybrid total aortic arch repair has achieved desirable outcomes in our center, which does not increase perioperative risk in the elderly patients, meanwhile, also acquire acceptable durability in the young patients. In conclusion, this surgery is a practical mini-invasive treatment for extensive aortic arch disease with strict and limited indications.

Objective Isolated true subclavian artery aneurysm (SAA) without aberrant subclavian artery or coarctation of descending aorta is a rare peripheral aneurysm. Herein, the experience of our medical center in the treatment of this disease is presented. Methods The Division operative log was queried to identify cases of SAA repair between January 2012 and September 2019 that were not associated with coarctation of the aorta or the presence of an aberrant subclavian artery. A total of 22 cases were identified. The characteristics, treatment and clinical outcomes of these cases were assessed. Results The mean age of patients was 53.5 ± 14.3 years and 14 patients were male (63.6%). Half of the cases were attributed to atherosclerotic degeneration. The clinical symptoms of aneurysms were varied, including asymptomatic, pulsatile mass of supraclavicular fossa, local pain, upper limb embolism, Horner's syndrome and hoarseness. Aneurysms were located on the right in 17 cases, on the left in 3 cases and on both sides in 2 cases. Fifteen (68%) patients underwent an intervention, of which 11 (50%) underwent an open surgical repair, and 4 (18%) underwent endovascular repair. The mean diameter of the aneurysms was 39.5 ± 20.7 mm in the open surgery group, and 24.0 ± 4.7 mm in the endovascular group. The follow-up duration ranged from 2 months to 12 years. One patient died of cardiogenic disease in the untreated group. Patients undergoing open operative repair had 100% patency of the reconstruction. In the endovascular group, one patient had stent occlusion 2 years after the operation. Conclusions The most common cause of isolated subclavian aneurysm without aberrant subclavian artery or coarctation of descending aorta is atherosclerosis. The clinical symptoms of aneurysms are varied, and the aneurysms tend to occur on the right side. Based on the anatomical conditions of SAAs, open surgery and endovascular repair can be used for treatment.

Studying the spatial pattern of population flows is important to gain insights into economic connections, city networks and traffic demand. The dearth of integrative data suggests that the spatial pattern of population migration has still received relatively scant research with modified algorithms despite its vital guidance in epidemic control. To address this gap, we employ unique social sensing data from the Tencent migration platform to investigate the spatial configuration of population migration in China. Based on the identified 2,555,596 aggregated origin-destination records in 2018, we map the spatial pattern of population flow with the algorithm of eigenvector centrality. The geovisualisation illustrates that population flows present an uneven spatial pattern with a clear east/west divide. The geovisualisation depicts that the cities with higher administrative levels show corresponding high centrality to a certain extent. The results also show that subnetworks of migration flow demonstrate that population flows are near movements.

OBJECTIVES The goal of this study was to compare the early-to-midterm outcomes of patients treated with the frozen elephant trunk procedure with aortic balloon occlusion (FET-ABO) versus hybrid repair for aortic arch diseases. METHODS Patients who underwent the FET-ABO (n = 134) and the hybrid procedure (n = 220) from 2017 to 2020 at our institution were analysed retrospectively. Early-to-midterm outcomes were compared using inverse probability weighting. Low-risk and high-risk subgroup analyses were performed according to the cut-off of the additive European System for Cardiac Operative Evaluation value of 6. RESULTS The present study demonstrated similar 30-day mortality (3.7% vs 8.6%; P = 0.118) and adverse events between the FET-ABO and the hybrid groups. Fewer intraoperative red blood cell transfusions (0.54 ± 1.45 vs 1.26 ± 2.47 U; P = 0.001), decreased total hospital costs (P CONCLUSIONS The FET-ABO technique could be better promoted in hospitals lacking experience and equipment and could be more viable and cost-effective for selected patients compared with the hybrid procedure.

In view of the problems of low accuracy, small rotational angle, and large impact caused by flexure joints during the deployment process, an integrated flexure revolute (FR) joint for folding mechanisms was designed. The design was based on the method of compliance and stiffness ellipsoids, using a compliant dyad building block as its flexible unit. Using the single-point synthesis method, the parameterized model of the flexible unit was established to achieve a reasonable allocation of flexibility in different directions. Based on the single-parameter error analysis, two error models were established to evaluate the designed flexure joint. The rotational stiffness, the translational stiffness, and the maximum rotational angle of the joints were analyzed by nonlinear finite element analyses. The rotational angle of one joint can reach 25.5° in one direction. The rotational angle of the series FR joint can achieve 50° in one direction. Experiments on single and series flexure joints were carried out to verify the correctness of the design and analysis of the flexure joint.

A symmetric, double-tripod multi-loop mechanism (DTMLM), for aerospace applications, is the subject of this paper. Its mobility and singularity are analyzed, while introducing a novel tool, the cell-division method for singularity analysis, applicable to multi-loop mechanisms. The key principle of this method lies in replacing the singularity analysis of the original multi-loop mechanism with: (1) that of an equivalent simpler parallel mechanism; (2) the constraint analysis between loops; and (3) the singularity analysis of simpler kinematic subchains. Then, the mechanism is transformed into a simpler, equivalent parallel mechanism with three identical kinematic subchains. Its mobility and singularity are analyzed based on screw algebra, which leads to a key conclusion about the geometric properties of this mechanism. Results show that: (a) the DTMLM has three degrees of freedom (dof), i.e., two rotational dof around two intersecting axes lying in the middle plane of the mechanism, and one translational dof along the normal to the said plane (2R1T); and (b) the singularities of the 3-RSR parallel mechanism are avoided in the DTMLM by means of prismatic joints, singularities in the DTMLM occurring on the boundary of its workspace. Thus, the DTMLM has a 2R1T mobility everywhere within its workspace. When a set of multi-loop mechanisms of this kind are stacked as modules to assemble a multi-stage manipulator for space applications, the modules can be designed so that, under paradigm operations, all individual loops operate within their workspace, safe from singularities.

A test platform for solar combined gas heating system was designed and established in Tianjin, control strategy for system operation was determined to meet domestic heating and hot water supply needs; basing on performance test, a series of evaluation indexes in energy saving, environmental protection and economic benefit for system operation were put forward; selecting 6 typical heating days in winter, the weight of each evaluation index in the series was analyzed by entropy weight method, it was found that, the index of renewable energy guarantee rate occupied the maximum weight, the indexes of static investment payback period and cost-benefit ratio occupied the minimum ones with the same weight ratio, finally a comprehensive evaluation method for system performance under different operating conditions was established. This study provided a comprehensive evaluation for system operation across meteorological states and operating conditions, so that making actual operation and testing data comparable and providing a reasonable evaluation scheme for the optimal configuration and operation of the system.

Background There are limited data regarding the clinical outcomes of reoperative aortic root or ascending aorta replacement after prior aortic valve replacement (AVR). We aimed to analyze outcomes of reoperative aortic root or ascending aorta replacement after prior AVR. Methods Eighty patients with prior AVR underwent reoperative aortic root or ascending aorta replacement in our hospital. The indications were root or ascending aortic aneurysm in 36 patients, root or ascending aortic dissection in 37, root false aneurysm in 2, prosthesis valve endocarditis (PVE) with root abscess in 2, Behcet's disease (BD) with root destruction in 3 patients. An elective surgery was performed in 63 patients and an emergent surgery in 17. The survival and freedom from aortic events during the follow-up were evaluated with the Kaplan-Meier survival curve and the log-rank test. Results The operative techniques included ascending aorta replacement in 14 patients, ascending aorta replacement with AVR in 3, prosthesis-sparing root replacement (PSRR) in 35, Bentall procedure in 24, and Cabrol procedure in 4 patients. Operative mortality was 1.3% (1/80). A composite of adverse events occurred in 5 patients, including 1 operative death, 2 stroke and 3 renal failure necessitating hemodialysis. The mean follow-up was 35.5±22.1 months. Five late deaths occurred. The Kaplan-Meier survival at 1 year, 3 years and 6 years were 97.5%, 91.1% and 84.1%, respectively. Aortic events developed in 3 patients. The freedom from aortic events at 1-year, 3-year, and 6-year were 100%, 96.3% and 88.9%, respectively. There were no differences in survival and freedom from aortic events between the elective group and the emergent group. Conclusions Reoperative aortic root or ascending aorta replacement after prior AVR could be performed to treat the root or ascending pathologies after AVR, with satisfactory early and midterm outcomes.

Space deployable mast, which is a supporting mechanism, especially for a space telescope, requires high repeatability. In this study, a deployed space tri-prism mast was taken as the research object, and the change of a tensional cable’s tension force was equivalent to an external load. Based on the accurate stiffness model of the mast, the repeatability of the tri-prism mast was calculated by using the Monte Carlo method. Then, the influences of the number of units, the change in the tension force, the thickness of the linkage, and the radius of the tensional cable on the repeatability of the tri-prism mast were studied. Moreover, the correctness of the analytical model was verified by the repeatability experiments. Results demonstrated that the proposed method could be used to analyze the repeatability of tri-prism mast. This study provided references and suggestions for the design of high-precision space deployable mast.

The development of space mission requires the lightweight, large deploying-to-folding ratios and high-precision deployable structures. The tape-spring hinge can achieve a deflection of 180 deg with...

Moderate hypothermic circulatory arrest (MHCA) with antegrade cerebral perfusion (ACP) is safe and efficient in total arch replacement (TAR) and frozen elephant trunk (FET) for acute type A aortic dissection (ATAAD). Complications related to hypothermia and ischemia are inevitable, however. The aortic balloon occlusion (ABO) technique is performed to elevate the lowest nasopharyngeal temperature to 28°C and shorten the circulatory arrest time. In this study, we aimed to evaluate the efficacy of this new technique.We reviewed the clinical data of patients with ATAAD who underwent TAR and FET, including 79 who underwent ABO and 109 who underwent MHCA/ACP.Circulatory arrest time was significantly lower in the ABO group compared with the MHCA/ACP group (mean, 4.8 ± 1.2 minutes vs 18.4 ± 3.1 minutes; P .001). The composite endpoint was comparable in the 2 groups (11.4% for ABO vs 13.8% for MHCA/ACP; P = .631). Fewer patients in the ABO group developed high-grade acute kidney injury (AKI) according to a modified RIFLE criterion (22.8% vs 36.7%; P = .041), and the rate of hepatic dysfunction was lower in the ABO group (11.4% vs 28.4%; P = .005). Multivariable logistic analysis showed that the ABO technique is protective against duration of ventilation24 hours (odds ratio [OR], 0.455; 95% confidence interval [CI], 0.234-0.887; P = .021), hepatic dysfunction (OR, 0.218; 95% CI, 0.084-0.561; P = .002), and grade II-III AKI (OR, 0.432; 95% CI, 0.204-0.915; P = .028).The ABO technique significantly shortens the circulatory arrest time in TAR and FET. Available clinical data suggest that it has a certain protective effect on the liver and kidney. Future large-sample studies are warranted to thoroughly evaluate this new technique.

In this study, a new type of cable-strut tensioned antenna mechanism is proposed and subjected to multi-objective optimization. First, a series of new cable-strut tension element configurations is proposed, and the optimal configurations are optimized on the basis of six topological characteristics of stable spatial cable-strut tensioned structures. Second, the mathematical surrogate models between configuration parameters, structural parameters, and fundamental frequencies of antenna mechanisms are established with the response surface method. Third, the optimization of the antenna mechanism synthesis is established, and the antenna configuration with optimal stiffness and mass synthesis is obtained with a genetic algorithm. Finally, the correctness and rationality of the proposed structural configuration is verified by developing a 2 m caliber prototype and conducting a dynamic characteristic test. The results should serve as a useful reference for the design of large caliber satellite antennas in aerospace engineering.

Cloud detection is one of the essential procedures in optical remote sensing image processing because clouds are widely distributed in remote sensing images and cause a lot of challenges, such as climate research and object detection. In this article, a lightweight deep-learning-based framework is proposed to detect cloud in remote sensing imagery. First, a multiple features fusion strategy is designed to extract learnable manual features and convolution features from visible and near-infrared bands. Then, a lightweight fully convolutional neural network (ClouDet) with a microarchitecture named dilated separable convolutional module is used to extract the multiscale contextual information and gradually recovers segmentation results with the same size as input image, which is more effective for large-scale cloud detection with larger receptive field, less parameters, and lower compute complexity. Third, context pooling is designed to amend the possible misjudgments. Visual and quantitative comparison experiments are conducted on several public cloud detection datasets, which indicates that our proposed method can accurately detect clouds under different conditions, which is more effective and accurate than the compared state-of-the-art methods.

OBJECTIVES Aortico-left ventricular tunnel (ALVT) is an extremely rare, abnormal paravalvular communication between the aorta and the left ventricle. Few studies have identified the characteristics and long-term prognosis associated with ALVT. METHODS The data of 31 patients with ALVT from July 2002 to December 2019 were reviewed. Echocardiography was performed in all patients during the follow-up period. RESULTS The median age of the patients was 11.5 years. Bicuspid aortic valve and dilatation of the ascending aorta were found in 13 patients, respectively. The aortic orifice in 20 patients showed a close relation to the right sinus and the right–left commissure. Of the 31 patients, 26 were operated on. Mechanical valve replacement was performed in 4 patients and aortic valve repair, in 6 patients. Ascending aortoplasty was performed in 5 patients and aortic replacement was done in 2 patients. One patient died of ventricular fibrillation before the operation. Follow-up of the remaining 30 patients ranged from 1 to 210 months (median 64 months). There were 4 deaths during the follow-up period: 1 had mechanical valve replacement and 3 did not undergo surgical repair. In the 26 patients without aortic valve replacement, 6 had severe regurgitation and 2 had moderate regurgitation. In the 28 patients without replacement of the ascending aorta, 11 had continued dilatation of the ascending aorta, including those who had aortoplasty. CONCLUSIONS The aortic orifice of ALVT showed an association with the right sinus and the right–left commissure. For patients who did not have surgery, the long-term survival rate remained terrible. Surgical closure should be done as soon as possible after ALVT is diagnosed. The main long-term complications after surgical repair included aortic regurgitation and ascending aortic dilatation.

OBJECTIVES Our goal was to investigate the surgical strategy for type Ia endoleak after thoracic endovascular aortic repair (TEVAR) by reporting our experiences. METHODS From November 2012 to September 2019, a total of 23 patients received surgical management for type Ia endoleak after TEVAR. RESULTS The operations included total arch replacement with the frozen elephant trunk technique in 15 patients, direct closure of the endoleak in 2 patients, hybrid aortic arch repair in 4 patients, arch debranching with TEVAR in 1 patient and left common carotid artery to left subclavian artery bypass with TEVAR in 1 patient. Among 21 patients with cardiopulmonary bypass (CPB), the mean CPB and aortic cross-clamp times were 146.7 ± 42.2 and 81.0 ± 43.3 min, respectively. The selective cerebral perfusion time was 18.8 ± 8.2 min in 17 patients with hypothermic circulatory arrest. The in-hospital mortality was 8.7% (2/23). Type Ia endoleak was sealed successfully after surgery in 95.5% (21/22) of patients. The follow-up data were available for all 21 survivors. The median follow-up period was 18 months (range 1–84 months). During the follow-up period, a total of 8 patients died or had aortic events, including 5 deaths and 6 aortic events. CONCLUSIONS Different surgical strategies could be selected to treat patients with type Ia endoleak after TEVAR, with acceptable early and late outcomes.

Background Data on the clinical features and surgical outcomes of type A intramural hematoma (IMH) in Chinese patients are very limited. We aimed to present the surgical experiences on type A IMH in our center, and report early and late outcomes. Methods From February 2012 to April 2018, 106 consecutive patients underwent open surgery for type A IMH at our hospital. We adopted emergent operation for patients with cardiac tamponade or other severe complications, and recommended initial medical treatment followed by elective surgery for stable patients. The composite endpoints included operative mortality, permanent nerve damage (stroke, paraplegia), and new-onset renal failure necessitating hemodialysis. Risk factors for operative mortality and the composite endpoints were identified using univariable and multivariable logistic regression model analysis. The survival and freedom from aortic events were analyzed using a Kaplan-Meier surviving curve and a log-rank test. Results Except 1 patient receiving emergent surgery (within 24 hours from onset) because of cardiac tamponade and cerebral malperfusion, all patients received initial medical treatment and delayed surgery. Two patient developed pericardial tamponade while waiting for surgery, and then received emergent surgery. Preoperative conversion to aortic dissection (AD) was noted in no patient. The operative techniques included ascending aorta replacement in 9 patients, hemiarch replacement in 18 patients, total arch replacement (TAR) with frozen elephant trunk (FET) in 45 patient and hybrid aortic arch repair in 34 patients. The mean cardiopulmonary bypass (CPB) time and cross-clamp time were 138.7±41.6 and 79.3±27.8 min, respectively. The operative mortality was 1.9% (2/106). And the composite endpoints occurred in 7 patients. Multivariable logistic regression analysis showed CPB time ≥200 min and chronic kidney disease were risk factors for the composite endpoints. The follow-up data were available in 97 survivors, with the mean follow-up time of 30.8±16.2 months. Three patients died and 5 patients developed aortic events during the follow-up. The overall survival at 1-, 3- and 5-year were 97.0%, 95.3%, and 79.4%, respectively. And freedom from aortic events at 1-, 3- and 5-year were 97.7%, 95.3% and 89.4%, respectively. Conclusions Our strategy had got low mortality and excellent mid-term survival in patients with type A IMH. Therefore, our strategy was suitable for the surgical repair of type A IMH in Chinese population.

In the DCF framework, a crucial component except DCF trackers is the adopted feature map, especially when we need the tracker to be applied in practical. The powerful feature map from CNN achieves an outstanding performance when compared to the handcrafted feature (HOG, Color-Name), however, it makes the tracker slower and could not meet the need in the real-time scene. In this paper, we visualize the respective feature maps, filter, and location score from CNN, HOG and ColorName, to make a comparison. We also dig into the detail of the target label, for balance the accuracy and robustness of the tracker. Experiments on OTB-2015 show the performance loss from handcrafted feature is acceptable for the real-time application.

Background Data on the association of breakfast habits and changes in cardiometabolic markers in children are limited. Methods In total, 6964 children aged 6–13 years from Beijing, Shanghai, Chongqing, Jinan, Harbin, and Guangzhou were included in the final analysis. Daily consumption, consumption of ≥3 food groups, and at-home consumption were defined as healthy breakfast habits. Blood pressure, % fat mass, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, glucose, and 50-m × 8 shuttle run were measured at baseline (May 2009) and follow-up (May 2010). Clustered cardiometabolic risk score (CCRS) was computed by summing Z scores of five components: % fat mass, systolic blood pressure, glucose, TC to HDL-C ratio, and triglyceride. Results Children who ate breakfast daily had a higher decrease in TC to HDL-C ratio and a higher increase in HDL-C compared with breakfast skippers (both P values

The study and prediction of soil liquefaction is an important and complex issue in geotechnical earthquake engineering. This paper attempts to compare the predictability of soil liquefaction potential between several machine learning classification models, which includes some tree-based classifiers, multilayer perceptron (MLP) neural networks, Support Vector Machine (SVM), some state-of-the-art ensemble methods, K nearest neighbors method, classical Naive Bayesian classifier and logistic regression. Three data sets covering shear-wave velocity measurements, cone penetration testing (CPT), and real historic earthquakes cases are employed to train and evaluate the machine learning classifiers. In order to make the best use of large varieties of statistical and machine learning classification algorithms, it is necessary to give a comparative evaluation of the model performance before model selection and offer advice on a unified stable model for all sorts of collected datasets. In the comparative study, data preprocessing is first performed to ensure the dataset into all machine models is of good quality. Then all three datasets with different input features are passed into the machine learning algorithms to obtain its confusion matrix and some evaluation indices. Reliable assessment of model performance is done through a repeated sub-sampling process. Experimental results are also supported by ROC curves. The results of this study indicated that although most machine learning methods are able to represent the complex relationship between seismic proper seismic properties of soils and corresponding liquefaction potential, ensemble learning has achieved more successful results in all three datasets test and can be a fairly promising approach on prediction of earthquake-induced soil liquefaction.

The development of phononic crystals, especially their interaction with topological insulators, allows exploration of the anomalous properties of acoustic/elastic waves for various applications. However, rapidly and inversely exploring the geometry of specific targets remains a major challenge. In this work, we show how machine learning can address this challenge by studying phononic crystal beams using two different inverse design schemes. We first develop the theory of phononic beams using the transfer matrix method. Then, we use the reinforcement learning algorithm to effectively and inversely design the structural parameters to maximize the bandgap width. Furthermore, we employ the tandem-architecture neural network to solve the training-difficulty problem caused by inconsistent data and complete the task of inverse structure design with the targeted topological properties. The two inverse-design schemes have different adaptabilities, and both are characterized by high efficiency and stability. This work provides deep insights into the combination of machine learning, topological property, and phononic crystals and offers a reliable platform for rapidly and inversely designing complex material and structure properties.

IntroductionSNW domain containing 1 (SNW1), as a splicing factor to regulate the activity of transcription factors, has been reported to be involved in multiple disease processes, including neuroblastoma. Whereas, the latent function and concrete mechanism of SNW1 in brain microvascular endothelial cells (BMECs) have not been clarified.Material and methodsBMECs were induced by oxidized low-density lipoprotein (ox-LDL), and high fat (HF)-fed rats were established. After SNW1 knockdown or NLR family pyrin domain containing 3 (NLRP3) overexpression, SNW1 and NLRP3 expressions were monitored via RT-qPCR, Western blot, or immunohistochemistry assays. Also, cell viability, apoptosis, and cholesterol efflux were determined via CCK-8, flow cytometry, and related kits; IL-18 and IL-3 levels were also certified by ELISA kits; and NLRP3 inflammasomes and cholesterol efflux-related proteins were identified by Western blot in vitro and in vivo.ResultsWe discovered that ox-LDL or HF-feeding significantly elevated SNW1 and NLRP3 expressions, and prominently induced BMECs injury in BMECs or rat brain tissues. Subsequently, our data confirmed that SNW1 knockdown markedly accelerated cholesterol efflux and viability, and prevented apoptosis and NLRP3 inflammasomes, which also could be reversed by NLRP3 overexpression in ox-LDL-induced BMECs. In addition, we showed that SNW1 knockdown could signally induce cholesterol efflux and repress NLRP3 inflammasome activation in HF-fed rats.ConclusionsWe demonstrated that SNW1 knockdown has a great protection effect on the dysfunction of BMECs by inhibiting NLRP3. So, SNW1 might be a therapeutic target for BMECs injury.

Background: This study was aimed to investigate the incidence, risk factors, and outcomes of patients with postoperative hepatic dysfunction (PHD) after frozen elephant trunk (FET) for type A aortic dissection (TAAD).Method: A retrospective study was performed with 492 patients who underwent FET for TAAD between 2015 and 2019. Independent risk factors for PHD were determined by multivariate mixed-effect logistic analysis with surgeon-specific factor as a random effect.Results: The incidence of PHD was 25.4% (n = 125) in our cohort. Patients with PHD presented higher early mortality (10.4 vs. 1.1%, p < 0.001), rates of acute kidney injury (42.4 vs. 12.8%, p < 0.001), and newly required dialysis (23.2 vs. 3.0%, p < 0.001) compared with those without PHD. Moreover, with the median follow-up period of 41.3 months, the survival curve was worse in patients with PHD compared with no PHD group (log-rank p < 0.001), whereas it was similar after excluding patients who died within 30 days (log-rank p = 0.761). Multivariable analyses suggested that PHD was predicted by preoperative aspartate transferase [odds ratio (OR), 1.057; 95% confidence intervals (CI), 1.036–1.079; p < 0.001], celiac trunk malperfusion (OR, 3.121; 95% CI, 1.008–9.662; p = 0.048), and cardiopulmonary bypass time (OR, 1.014; 95% CI, 1.005–1.023; p = 0.003). Retrograde perfusion (OR, 0.474; 95% CI, 0.268–0.837; p = 0.010) was associated with a reduced risk of PHD. Celiac trunk malperfusion was an independent predictor for PHD but not associated with early mortality and midterm survival.Conclusions: PHD was associated with increased early mortality and morbidity, but not with late death in midterm survival. PHD was predicted by preoperative aspartate transferase, celiac trunk malperfusion, and cardiopulmonary bypass (CPB) time, and retrograde perfusion was associated with a reduced risk of PHD.

Aiming at a series of characteristics of the membrane structure in the folded configuration during the deploying process, the initial defect of the membrane crease is introduced by proxy model, and to realize the study of the deploying process of the membrane. Based on the finite element method, the deploying process of the multi-element Miura membrane is simulated. And the stretch ratio, maximum mises stress, deployment rate, wrinkle deformation, etc. of membrane structure are discussed. The existence of creases can cause damage to the membrane surface, so the total length of the creases should be within an appropriate size range. By changing the number of elements and the longitudinal crease angle of the same size membrane respectively, the influence of the above two factors on the total crease length, storage volume and deploying process of the folded membrane is studied. The results show that when the longitudinal crease angle is 15°, the transverse and longitudinal displacements of the Miura folded membrane with different element numbers are not synchronized during the deploying process. By keeping the number of elements constant and increasing the angle of the longitudinal creases from 15° to 45°, the synchronization of the transverse and longitudinal displacements during the membrane deploying process is gradually enhanced. In addition, the experiment on the membrane deploying process verifies the reliability of the finite element simulation results.

Background Village clinic doctors (VCDs) are part of the health service force in rural China. VCDs’ job satisfaction (JS) is important to the stability of the three-tiered health service system. Since 2009, the Chinese government launched a new health care system reform (NHCSR) which affected VCDs significantly. This study aimed to analysing the effect of NHCSR on JS among VCDs. Methods All the data came from three surveys in Shandong Province conducted in 2012, 2015 and 2018. In 2012, an originally designed questionnaire was used to conduct a baseline survey of 405 VCDs from 27 townships in nine counties. In 2015 and 2018, 519 and 223 VCDs in the same counties were surveyed with the same questionnaire. Descriptive analysis and ANOVA were used to analyse the level and changes in VCDs’ JS. Results The mean scores of VCDs’ total JS were 2.664 ± 1.069, 3.121 ± 0.931 and 2.676 ± 1.044 in 2012, 2015 and 2018, respectively, with a significant difference (F = 28.732, P Conclusion The NHCSR had a partly negative impact on VCDs’ JS. Policy-makers should pay more attention to VCDs’ job reward and medical practice environment. With the implementation of new reform policies, VCDs’ JS should be the subject of more systematic and detailed research.

Background Platelet-rich plasma (PRP), processed from autologous peripheral blood, is used to treat androgenetic alopecia (AGA). Objective To determine the efficacy of PRP for hair growth promotion in AGA patients in a randomized, blinded, placebo-controlled, pilot clinical trial (NCT02074943). Methods The efficacy of an 8 week, five session, PRP treatment course was determined by measuring hair density and hair caliber changes in 10 AGA affected patients. For each PRP sample, the concentrations of selected growth factors were determined using a multiplex assay system. The clinical results were then correlated with the growth factor concentrations in PRP. Results At 16 weeks, 8 weeks after the last PRP injection, treated areas exhibited increased mean hair density (+12.76%) over baseline compared to placebo (+0.99%). Mean hair caliber decreased in both treated and placebo regions (-16.22% and -19.46%, respectively). Serial analysis of PRP significant variability in concentrations between patients. Overall, there was a positive correlation between GDNF concentration and hair density (P = .004). Trends, though not statistically significant, were also observed for FGF2 and VEGF. Limitations Small sample size and lack of comparative cohorts receiving protocol variations limit confidence in the study data. Conclusions This small pilot clinical trial suggests PRP treatment may be beneficial for AGA. However, the variable hair growth responses between patients indicate there is a significant opportunity to improve PRP therapy protocols for hair growth promotion. The variability in growth factor concentration in PRP suggests standardization of growth factors postprocessing might improve hair growth responses.

The hinge, a key component of deployable space mechanism, has a significant influence on the precision of the whole mechanism. Hysteresis is one of the uncontrollable factors affecting the precision of the hinge. However, much work so far has focused on the equivalent model of hysteresis, which is far from the actual situation. In this paper, the hysteresis model of the general rotary hinge was established via the finite element method (ABAQUS/Standard 6.14-4). The correctness of the model was verified by experiments, and the loss factor was defined to measure the size of hysteresis. The response surface method was then used to establish the response surface of the hysteresis loss factor of the general rotary hinge. Results show that the hinge was optimised. By comparing the response surfaces of the two types of hinges, the modified hinge can effectively reduce hysteresis loss factor. Importantly, the repeatability of the hinge can be effectively improved by reducing hysteresis loss factor through repeatability experiments. Using this method, the response surface of the hinge’s hysteresis loss factor can be established accurately, and the hysteresis loss factor can be reduced through optimal design to improve the precision of the hinge. This method can provide reference and guidance for the hinge design of the high-precision deployable mechanism.

A 3D spherical panoramic epipolar line based on essential matrix is proposed in this study to solve the search range to improve calculation efficiency and reliability of the matching. First, this method uses the essential matrix of computer vision principles to establish the epipolar geometry model of spherical panoramic image. Second, it derives the epipolar line mathematical equations and characteristics of spherical panoramas. Third, it calculates statistics on the distribution law of epipolar images. Experimental results show that the feasibility of the method proposed in this study. The proposed method effectively verified the trajectory of the spherical panoramic epipolar line, finished distribution of epipolar line sequence trajectory and decreased the search range of the corresponding points. The findings help lay a solid foundation for the matching and measurement of the panoramic measurement model and the generation of depth maps.

The efficient convolution operator (ECO) have manifested predominant results in visual object tracking. However, in the pursuit of performance improvement, the computational burden of the tracker becomes heavy, and the importance of different feature layers is not considered. In this paper, we propose a self-adaptive mechanism for regulating the training process in the first frame. To overcome the over-fitting in the tracking process, we adopt the fuzzy model update strategy. Moreover, we weight different feature maps to enhance the tracker performance. Comprehensive experiments have conducted on the OTB-2013 dataset. When adopting our ideas to adjust our tracker, the self-adaptive mechanism can avoid unnecessary training iterations, and the fuzzy update strategy reduces one fifth tracking computation compared to the ECO. Within reduced computation, the tracker based our idea incurs less than 1% loss in AUC (area-undercurve).

Purpose Total aortic arch replacement (TAR) with frozen elephant trunk (FET) is the standard operation for treating aortic dissection (AD) patients involving aortic arch with high operative risk due to long circulatory arrest (CA). We used aortic balloon occlusion technique that safely reduced the CA time to 5 min in average and investigated whether it can improve the clinical endpoints. Methods All patients diagnosed with AD and underwent TAR with FET operation (123 with aortic balloon occlusion and 221 with conventional method) in Fuwai Hospital during August 2017 and February 2019 was reviewed in this retrospective observational study. Results After propensity score matching, the 30-day mortality of aortic balloon occlusion group and conventional group was 4.88% and 11.38% (P = 0.062), respectively. In multivariate analysis, aortic balloon occlusion is one of the factors that reduced the risk for renal and hepatic injury, shortened postoperative conscious revival time, and reduced red blood cell (RBC) transfusion during operation. Conclusions The aortic balloon occlusion technique, as a perfusion strategy during operation, could alleviate postoperative complication. This method deserves further attention in future clinical practice for its value in treating patients with higher operative risks.

A C-cross section thin-walled composite deployable boom (C boom) can be flattened and coiled elastically. Furthermore, C boom can be deployed by releasing stored strain energy. Finite element (FE) models of C booms are constructed based on a nonlinear explicit dynamics analysis. The full simulation is divided into six consecutive steps: flattening, end-compacting, releasing, coiling, holding, and deploying around a hub. An optimal design method for the coiling and deploying of the C boom is presented based on the response surface method (RSM). Twenty-seven sample points are obtained by using a full-factorial design of experiment method. Surrogate models of the maximum moment and stress during the fully simulated process, including the mass of the C boom, are created by the RSM. The maximum moment and mass are set as objectives, and the maximum stress is set as a constraint to increase deploying statue stiffness and enhance use times. A multi-objective optimization design of the C boom is performed by sequential quadratic programming algorithm. Lastly, FE models for the optimal design are built to validate the accuracy of the optimization and the response surface results.

Hot electron transistors (HETs) containing two-dimensional (2D) materials promise great potential in high-frequency analog and digital applications. Here, we experimentally demonstrate all-2D van der Waals (vdW) HETs formed by graphene, hBN, and WSe2, in which the polarity of carriers could be tuned by changing bias conditions. We proposed a theoretical model to distinguish hot hole and hot electron components in the ambipolar vdW HET. Importantly, both hot hole and hot electron modes are achieved with pronounced saturation behavior as well as record-high collection efficiency approaching theoretical limits (99.9%) at room temperature. The vdW HETs show a maximum output current density of 400 A/cm2. The observed ambipolar hot carrier transport with high collection efficiency is promising for high-speed nanoelectronics and 2D hot electron spectroscopy.

Mangiferin is the major bioactive ingredient in the leaves of Mangifera indica L., Aqueous extract of such leaves have been traditionally used as an indigenous remedy for respiratory diseases including cough and asthma in Traditional Chinese Medicine. Mangiferin was shown to exert its anti-asthmatic effect by modulating Th1/Th2 cytokines imbalance via STAT6 signaling pathway. However, compelling evidence indicated that subtypes of T helpers and regulatory T cells other than Th1/Th2 were also involved in the pathogenesis of asthma. In current study, we investigated the effects of mangiferin on the differentiation and function of Th9, Th17 and Treg cells in a chicken egg ovalbumin (OVA)-induced asthmatic mouse model. Mangiferin significantly attenuated the symptoms of asthma attacks, reduced the total number of leukocytes, EOS and goblet cells infiltration in lung. Simultaneously, treatment with mangiferin remarkably decreased the proportion of Th9 and Th17 cells; reduced the levels of IL-9, IL-17A; inhibited the expression of PU.1 and RORγt in lung. However, the proportion of Treg cells, the expression of IL-10, TGF-β1 and Foxp3 were increased by mangiferin. Our data suggest that mangiferin exerted anti-asthmatic effect through decreasing Th9 and Th17 responses and increasing Treg response in OVA-induced asthmatic mouse model.

To ensure both cerebral and lower body perfusion during total arch replacement with frozen elephant trunk, aortic balloon occlusion technique has been applied in some cases at our institute. During the procedure, after stented elephant trunk is inserted into the true lumen of the descending aorta, an aortic balloon catheter is placed and inflated within the stented elephant trunk, occluding the orifice of descending aorta. Then, lower body perfusion is provided via femoral cannulae during distal aortic arch anastomosis. We describe the perfusion management strategy of the technique, elucidate intraoperative monitoring parameters, and clarify the feasibility of the method from the aspect of perfusion.

Capturing non-cooperative targets in space is a cutting-edge technology in the aerospace field. In this study, a novel n(3RRlS) metamorphic serial-parallel manipulator (MSPM) with multiple working conditions is proposed, which can serve as the fingers of a large-scale reconfigurable space multifingered hand (LSRSMFH). First, a limb combination coding method is proposed to describe the topological graph and determine the isomorphism of the n(3RRlS) MSPM. Subsequently, the topological graphs and the limb combination codes (LCCs) of the 1(3RRlS) MSPM, 2(3RRlS) MSPM and 3(3RRlS) MSPM are further analyzed, and the isomorphism of all the actuation distribution configurations (ADCs) and metamorphic configuration states (MCSs) is determined. Second, a two-actuator method is applied for the n(3RRlS) MSPM, and the workspaces of all MCSs of all ADCs of the 1(3RRlS) MSPM, 2(3RRlS) MSPM and 3(3RRlS) MSPM are analyzed using a transformation method. The results show that the n(3RRlS) MSPM can realize their respective functions of the LSRSMFH under three working conditions with the minimum number of actuators, which can reduce the number of actuators and the weight of the LSRSMFH and can gain benefits in multitask adaptability, simplified control, precision and rigidity improvement, energy saving and risk reduction.

Compared with non-overconstrained deployable units, overconstrained deployable units are widely used in space missions for their higher stiffness characteristics. Besides the performance of a three-step topological structural analysis and design of the rectangular pyramid deployable truss unit (PDTU), conducting a structural synthesis of an overconstrained deployable unit requires the determination of the relative position and direction of each kinematic axis. The structural synthesis of an overconstrained deployable unit is investigated based on screw theory and its topological structure. The possible overconstrained cases of the rectangular PDTUs are analyzed, and corresponding screw expressions are obtained. Thus, the rectangular PDTUs, which can be folded into a plane, are synthesized systemically, and a series of overconstrained rectangular PDTUs is obtained. Furthermore, the feasibility of the folded and deployed motions under one degree of freedom for those deployable units is verified in dynamical simulation by using ADAMS 2010. Keywords: Assembly SAR antenna, Common overconstraint, Deployable truss structure, Screw theory, Structural synthesis

Background: Patients with anaplastic lymphoma kinase (ALK) rearrangements are particularly prone to development of brain metastases (BMs). Newer anti-ALK treatments have demonstrated far greater intracranial efficacy. Here we performed a meta-analysis with the aim of assessing the efficacy of ALK inhibitors on BMs. Methods: A search of published trials was conducted in PubMed, The Cochrane Library, Web of Science, and Embase. Data were pooled using the number of events/number of evaluable patients (non-small cell lung cancer patients with BMs) according to fixed or random effect models. Intracranial efficacy was assessed through overall response rate (ORR), disease control rate (DCR), and median progression-free survival (PFS). Subgroup analyses for baseline BMs, previous treatment with ALK inhibitor, study type, and current ALK inhibitor were made. Results: Twenty studies accounting for 2,715 patients were included. The pooled iORR was 48% (95% CI: 32–63%) in fifteen single-arm studies. The overall DCR was 65% (95% CI: 60–69%) from three studies include available data. The iORR was 79% (95% CI: 64–91%), 45% (24–67%), 48% (34–63%), 18% (13–24%) in patients receiving alectinib, ceritinib, brigatinib, and crizotinib, respectively. Five randomized studies assessed the intracranial efficacy of anti-ALK agents versus chemotherapy, the pooled RR for iORR was 3.54 (95% CI: 2.38–5.26), and the pooled HR for iPFS was 0.52 (95% CI: 0.36–0.75; P=0.71) estimated in 2 studies. Conclusions: Despite the limitation from lack of published clinical data, our results showed that ALK inhibitors are effective at the brain site regardless of previous anti-ALK treatments, systemic therapy with ALK inhibitors should be considered as a preferred approach over for controlling BMs from ALK-positive NSCLC.

In phase-shifting fringe projection profilometry, the projector nonlinearity has been recognized as one of the main error-inducing factors, especially when only very few fringe patterns are available. For solving this issue, this paper presents a simple and effective method, that allows us to recognize and remove, directly from a calculated phase map, the nonlinearity-induced errors without calibrating the projector luminance or the phase errors in advance. In implementation, after filtering the phase map using a low-pass filter, we estimate the phase error coefficients by exploiting the dependence between the isolated artifacts and the smoothed phases under 3-sigma criterion. Furthermore, using the phase error function just estimated, the phase errors are corrected in a pointwise way through fixed-point iterations. Experimental results demonstrated that this method offers some advantages over others, such as being independent of a special nonlinearity model, being easy to implement and not requiring a prior calibration, protecting the edges and details of the measured shape from being blurred, and enabling dealing with time-variant projector nonlinearities.

Motion strategy analysis at the pre-bending stage is a fundamental component of underactuated finger grasp research. This study presents the pre-bending motion strategy and corresponding analysis of cable driving forces a 3-DOF underactuated finger comprising cable truss units. This robotic finger uses a tendon-pulley transmission and parallel four-linkage mechanism to realize the grasp capability. The structure and four motion strategies at the pre-bending stage are illustrated. The equivalent joint-driven and quasi-static motion models are established in the case where one or two cable driving forces drive the finger. In accordance with the virtual work principle, the tendon-pulley transmission is transformed into an equivalent joint-driven system. On the basis of the constraints of maximum motion space of the finger, the joint spring stiffness distributions are discussed and the finger quasi-static motion space is analyzed under the condition of single motor driving force. The unique coupled motion process and corresponding cable driving force of the finger driven by a single motor are assessed. Furthermore, three other typical quasi-static motion strategies and their corresponding cable driving forces are discussed. Valid simulation experiments are conducted to verify the accuracy of the quasi-static motion strategy. The analysis of this study can provide guidance and a theoretical reference for the design of cable-driven underactuated hands and control of the couple-driven underactuated mechanism.

Background: Total aortic arch replacement (TAR) with frozen elephant trunk (FET) surgery provides improved long-term results, but the surgery itself is associated with higher risks compared with isolated proximal reconstructions. We applied an aortic balloon occlusion (ABO) technique to reduce the circulatory arrest (CA) time and improve other clinical outcomes.Methods: All patients who underwent TAR with FET surgery (130 with ABO technique, 230 with the conventional approach) in Fuwai Hospital from August 2017 to February 2019 were reviewed in this retrospective observational cohort study. Intra- and early-postoperative results and clinical characteristics were analyzed.Results: After 1:1 propensity score matching (130 cases in each group), the 30-day mortality of the ABO group and the conventional group were 4.6% and 10.8% (p = 0.063), respectively. Although the reduction in complications was not statistically significant, the complication rate in the ABO group was relatively low, having fewer cases of postoperative renal (23.1 vs. 38.5%, p = 0.007) and hepatic (12.3 vs. 30.0%, p < 0.001) injury, lower postoperative wake-up time (15.2 ± 23.6 h vs. 20.1 ± 26.5 h, respectively, p < 0.001), reduced chest tube output (176.03 ± 143.73 ml vs. 213.29 ± 130.12 ml, respectively, p = 0.003), lower red blood cell transfusion volume (4.98 ± 6.53 u vs. 7.28 ± 10.41 u, respectively, p = 0.008), and no fatal events.Conclusions: The ABO technique is a simple method that can reduce the CA time and improve the recovery stage following TAR with FET surgery. The technique represents a practical strategy to treat patients with high operative risks due to its lower complication rate compared with the conventional approach.

Background: In 2009, the Chinese government launched a new health care system reform. One of the important aims of the reform was to improve the capacity of primary health institutions. Village clinic doctors are part of the health service force rooted in rural China and the basis of the three-tiered health service system. The job satisfaction of village clinic doctors has an important impact on the stability and sustainable development of the three-tiered health service system. This study aimed to analyse the changes in village clinic doctors' job satisfaction after the implementation of the new health care system reform.Methods:All the data came from three surveys of village clinic doctors in Shandong Province conducted in 2012, 2015 and 2018. In 2012, an originally designed questionnaire was used to conduct a baseline survey of 405 village clinic doctors from 27 townships in 9 counties (the response rate was 92.9%). In 2015 and 2018, 519 and 223 village clinic doctors in the same counties were surveyed with the same questionnaire (the response rates were 94.3% and 92.9%, respectively). Descriptive analysis, χ2 test and ANOVA were used to analyse the level of and changes in village clinic doctors' job satisfaction.Results: The mean scores of village clinic doctors' total job satisfaction were 2.664 ± 1.069, 3.121 ± 0.931 and 2.676 ± 1.044 in 2012, 2015 and 2018, respectively, with a significant difference (F = 28.732, P < 0.001). The mean scores of the medical practice environment and the job itself showed a continuous downward trend. The change trends of the mean scores for job reward, internal work environment and organizational management were consistent with the trend for total job satisfaction.Conclusion: After the implementation of the NHCSR, the job satisfaction of village clinic doctors showed a trend of first rising and then falling. To improve primary health care service capacity, the Chinese government has implemented a series of new reform policies. With their ongoing implementation, village clinic doctors' job satisfaction should be the subject of more systematic and detailed research.

Background: This study employed three surgical techniques: total arch replacement (TAR) with frozen elephant trunk (FET), aortic balloon occlusion technique (ABO) and hybrid aortic arch repair (HAR) on patients with type I aortic dissection in Fuwai Hospital, aiming to compare the early outcomes of these surgical armamentariums.Methods: From January 2016 to December 2018, an overall 633 patients (431 of TAR+FET, 122 of HAR, and 80 of ABO) with type I aortic dissection were included in the study. Thirty-day mortality, stroke, paraplegia, re-exploration for bleeding, and renal replacement therapy were compared using the matching weight method (MWM).Results: After MWM process, the baseline characteristics were comparable among three TAR groups. It showed that ABO group had the longest cardiopulmonary bypass (p < 0.001) and aortic cross-clamp time (p < 0.001), while the operation time was longest in the HAR group (p = 0.039). There was no significant difference in 30-day mortality among groups (p = 0.783). Furthermore, the incidence of stroke (p = 0.679), paraplegia (p = 0.104), re-exploration for bleeding (p = 0.313), and CRRT (p = 0.834) demonstrated no significant difference. Of note, no significant differences were found regarding these outcomes even before using MWM.Conclusions: Based on the early outcomes, the three TAR approaches were equally applicable to type I aortic dissection. We may choose the specific procedure relatively flexibly according to patient status and surgeon's expertise. Importantly, long-term investigations are warranted to determine whether above approaches remain to be of equivalent efficacy and safety.

The traditional water quality monitoring methods are time-consuming and laborious, which can only reflect the water quality status of single point scale, and have some problems such as irregular sampling time and limited sample size. Remote sensing technology provides a new idea for water quality monitoring, and the temporal resolution of MODIS is one day, which is suitable for long-term, continuous real-time large-scale monitoring of lakes. In this study, Lake Simcoe (located in Ontario, Canada) was selected as the research area. The long-term spatiotemporal changes of chlorophyll-a, transparency, total phosphorus and dissolved oxygen were analyzed by comparing the empirical method, multiple linear regression, random forest and neural network with MODIS data. Finally, the water quality condition of Lake Simcoe is evaluated. The results show that the overall retrieval results of two machine learning models are better than that of the empirical method. The optimal retrieval accuracy R² for four water quality parameters are 0.976, 0.988, 0.943, 0.995, and RMSE are 0.13μg/L, 0.3m, 0.002mg/L and 0.14mg/L, respectively. On the annual scale, the annual mean values of the four water quality parameters during the 10-year period from 2009 to 2018 were 1.37μg/L, 6.9m, 0.0112mg/L and 10.17mg/L, respectively. On the monthly scale, chlorophyll a, total phosphorus and dissolved oxygen first decreased and then increased at the time of year. The higher concentrations of chlorophyll a and total phosphorus in the south and east of Lake Simcoe are related to the input of nutrients from the surrounding residents and farmland.Key words: water quality monitoring; MODIS; empirical method; machine learning

To meet the requirement of large aperture development trend of space deployable antenna, a space deployable antenna with high folding ratio and light weight is researched. A folding rib deployable antenna mechanism configuration is proposed and the structure analysis of deployable antenna mechanism is carried out based on modular design idea. Based on the basic theory of robotics, the forward kinematics model of the mechanism is established, and the inverse kinematics analysis is carried out from two aspects: identification of deployment state and research on driving law. The mechanism principle, forward kinematics model and inverse kinematics analysis are verified by numerical simulation software. The numerical simulation results show that the folded rib deployable antenna mechanism can realize the movement change from fully stowed to fully deployed without singularity. The movement law of key points at the end of mechanism is closely related to the development law of each corner in mechanism. The configuration scheme of folding rib deployable antenna mechanism proposed in this paper is reasonable and feasible. The established forward/reverse kinematic model can provide reference and help for kinematic characteristics analysis of mechanism and driving law research of mechanism.

With the in-depth study of the construction of space bases, the demand for super-large deployable manned cabins in space is becoming increasingly urgent. In this study, a brand-new large space modular expandable cabin mechanism is proposed, and equivalent mechanical modeling research is conducted based on its modular characteristics. First, the overall configuration and the deployment driving scheme of the cabin section with the best comprehensive performance are optimized. In addition, a detailed structural design of the cabin section mechanism is carried out. Second, the mechanical equivalent continuous model of the cabin mechanism is established. The static and dynamic characteristics of the cabin mechanism are studied based on finite element simulation and equivalent model calculation, respectively. The correctness of the equivalent mechanical model established in this study is verified through comparative analysis. Finally, a scaled prototype is developed to verify the feasibility of the configuration and the new drive proposed in this study.

Background Aortic arch disease with Kommerell's diverticulum is an uncommon but troublesome condition, and there are a variety of therapeutic modalities for treating this. We retrospectively analyzed cases who underwent open surgery to summarize different situations and approaches. Methods From November 2015 to January 2019, nine patients underwent operation for the mentioned disorder. Four patients with aortic dissection received total arch replacement. Two patients suffering from type B aortic dissection (TBAD) have accepted graft replacement from ascending aorta (aAO) to descending aorta. Two patients with true aneurysm and congenital malformation underwent graft bypass from aAO to descending aorta. One patient had graft replacement of descending aorta. Results There were nine (eight males and one female) patients with median age of 45 (from 14 to 54) years. The 30-day mortality was 11.1% (1 patient) due to refractory respiratory failure caused by compression of bronchus. One patient had complication of peripheral neuropathy and recovered eventually. Eight patients were followed-up for a median period of 20 [9-46] months. All patients were alive and had no long-term complications except one patient who received re-intervention due to delayed dilation of downstream aorta. Conclusions Treatment for different arch lesions with Kommerell's diverticulum should follow corresponding indications. Open surgery is the preferred choice and detailed therapeutic strategy depends on the extension of aneurysm, classification and phase of dissection. Stenting might cause airway compression when right-sided arch and vascular ring exist.

This study aimed to compare clinical outcomes of patients treated by total arch replacement (TAR) with frozen elephant trunk (FET), aortic balloon occlusion (ABO) technique and hybrid arch repair (HAR). Between January 2017 and July 2019, 643 consecutive patients with aortic arch diseases were eligible for TAR, including 356 in conventional FET, 112 in ABO based on FET, and 175 in HAR. A retrospective cohort analysis of perioperative results was undertaken, performed with inverse probability weighting. The primary endpoint was composite endpoints included 30-day mortality, stroke, paraplegia, hemodialysis, reintubation, and intra-aortic balloon pump or extracorporeal membrane oxygenation support, and visceral dysfunction was secondary endpoint. Overall in-hospital mortality was 2.2% (FET = 2.5% vs ABO = 0 vs HAR = 2.9%, P= 0.210). Parallel early outcomes were demonstrated among three groups. ABO group was associated with significantly shorter circulatory arrest time (5, IQR 3-7 vs 16, IQR 14-18 minutes, P0.001), and a lower incidence of visceral dysfunction compared with FET group (25.1% vs 47.3%, P= 0.003). Patients receiving ABO suffered a significantly lower rate of prolonged ventilation (more than 72 hours; P= 0.014). Furthermore, a tendency toward decreasing composite endpoints was suggested in ABO (7.2%) compared with FET (15.5%, P= 0.061) and HAR (19.8%, P= 0.032). ABO technique obtains considerable early clinical outcomes for TAR compared with conventional FET and HAR, which could be a feasible and effective approach for patients with aortic arch diseases.

Background Acute type A aortic dissection with a dissection flap extending into the sinus segment often involves the commissures and the coronary ostia. In most cases, the intimal flap must be retained in order to restore aortic valve competence and reconstruct the coronary ostia. Residual dissection flap has the potential risks of proximal bleeding and adverse effects on long-term durability. We established a novel technique to reconstruct the aortic root using a pericardial autograft and significantly reduce remnant dissection tissues. Case presentation A 50-year-old female was admitted to our center with acute anterior chest pain and backache lasting about 10 h. Computed tomographic (CT) scans showed type A aortic dissection, with both coronary ostia being involved. Doppler echocardiography showed moderate aortic insufficiency. The dissection intimal flap was removed to the normal aorta wall near the annulus at the noncoronary sinus, leaving a 5 mm rim of intimal flap near the commissures and coronary ostia. Using a pericardial patch as a new aortic wall to reconstruct the root while preserving the aortic adventitia to fix and strengthen the new pericardial aortic wall. Ascending aorta and total arch replacement combined with frozen elephant trunk procedure was performed at the same time. The patient got an uneventful postoperative course. Conclusion Aortic root repair with a pericardial autograft is a safe and effective technique to treat acute type A dissection involving the sinus. Using this technique, residual dissection tissues could be significantly reduced, which subsequently decreases the risk of proximal bleeding and hence increases long-term durability.