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This study discusses a smart radar antenna scanning mode that combines features of both the sector-scan mode used for conventional radar and the line-scan mode used for synthetic aperture radar (SAR) and achieves an application of the synthetic aperture technique in the conventional sector-scan (mechanically scanned) radar, and we refer to this mode as sector-scan synthetic aperture radar (SSAR). The mathematical model is presented based on the principle of SSAR, and a signal processing algorithm is proposed based on the idea of two-dimensional (2D) matched filtering. The influences of the line-scan range and speed on the SSAR system are analyzed, and the solution to the problem that the target velocity is very high is given. The performance of the proposed algorithm is evaluated through computer simulations. The simulation results indicate that the proposed signal processing algorithm of SSAR can gather the signal energy of targets, thereby improving the ability to detect dim targets. [ABSTRACT FROM AUTHOR]

Background: We retrospectively reviewed our experience of total arch replacement in patients undergoing repair of an ascending aortic dissection following previous cardiac surgery.Methods: Data were collected for patients with acute type A aortic dissection following previous cardiac surgery between January 2005 and December 2014. Clinical and prognostic features were retrospectively analyzed.Results: Twenty-eight eligible patients (nonelective: 10, elective: 18) were identified. There was a mean period of 44.5 months between the first operation and the subsequent surgery. The overall 30-day mortality rate was 21.4%; 30.0% for nonelective patients and 16.7% for elective patients. Postoperative morbidity rate was higher among nonelective patients versus elective group. During follow-up, two patients died: one from intracranial hemorrhage and the other from a noncardiac cause. One patient received endografting as a result of the true lumen being compressed by the false lumen following aortic repair.Conclusions: When hemodynamically stable, patients with acute ascending aortic dissection following previous cardiac surgery may have improved outcomes if the surgery can be performed on an elective basis. [ABSTRACT FROM AUTHOR]

Phlorotannins are phenolic compounds with diverse biological activities, yet their efficacy in aquatic animals currently remains unclear. This investigation scrutinized the influence of phlorotannins on the growth, immunity, antioxidant capacity, and intestinal microbiota in Litopenaeus vannamei , concurrently evaluating the potential adverse effects of phlorotannins on L. vannamei. A base diet without phlorotannins supplementation was used as a control, and 4 groups of diets with different concentrations (0, 0.5, 1.0, 2.0 g kg−1) of phlorotannins were formulated and fed to juvenile shrimp (0.25 ± 0.01 g) for 60 days followed by a 24-h challenge with Vibrio parahaemolyticus with triplicate in each group. Compared with the control, dietary 2.0 g kg−1 phlorotannins significantly improved the growth of the shrimp. The activities of enzymes related to cellular immunity, humoral immunity, and antioxidants, along with a notable upregulation in the expression of related genes, significantly increased. After V. parahaemolyticus challenge, the cumulative survival rates of the shrimp demonstrated a positive correlation with elevated concentrations of phlorotannins. In addition, the abundance of Bacteroidetes and functional genes associated with metabolism increased in phlorotannins supplementation groups. Phlorotannins did not elicit any detrimental effects on the biological macromolecules or histological integrity of the hepatopancreas or intestines. Simultaneously, it led to a significant reduction in malondialdehyde content. All results indicated that phlorotannins at concentrations of 2.0 g kg−1 can be used as safe feed additives to promote the growth, stimulate the immune response, improve the antioxidant capacity and intestinal health of L. vannamei , and an protect shrimp from damage caused by oxidative stress. • Phlorotannins improved the growth, immunity, and antioxidant capacity of L. vannamei. • Phlorotannins improved the intestinal barrier function through shaping the intestinal microbiota of L. vannamei. • Phlorotannins within the range of 2.0 g kg-1 did not cause metabolic or pathological damage to L. vannamei. • The optimal addition amount of phlorotannins is recommended to be 2.0 g kg−1. [ABSTRACT FROM AUTHOR]

Background: Sympathoexcitation contributes to myocardial remodeling in heart failure (HF). Increased circulating pro-inflammatory mediators directly act on the Subfornical organ (SFO), the cardiovascular autonomic center, to increase sympathetic outflow. Circulating mitochondria (C-Mito) are the novel discovered mediators for inter-organ communication. Cyclic GMP–AMP synthase (cGAS) is the pro-inflammatory sensor of damaged mitochondria. Objectives: This study aimed to assess the sympathoexcitation effect of C-Mito in HF mice via promoting endothelial cGAS-derived neuroinflammation in the SFO. Methods: C-Mito were isolated from HF mice established by isoprenaline (0.0125 mg/kg) infusion via osmotic mini-pumps for 2 weeks. Structural and functional analyses of C-Mito were conducted. Pre-stained C-Mito were intravenously injected every day for 2 weeks. Specific cGAS knockdown (cGAS KD) in the SFO endothelial cells (ECs) was achieved via the administration of AAV9-TIE-shRNA (cGAS) into the SFO. The activation of cGAS in the SFO ECs was assessed. The expression of the mitochondrial redox regulator Dihydroorotate dehydrogenase (DHODH) and its interaction with cGAS were also explored. Neuroinflammation and neuronal activation in the SFO were evaluated. Sympathetic activity, myocardial remodeling, and cardiac systolic dysfunction were measured. Results: C-Mito were successfully isolated, which showed typical structural characteristics of mitochondria with double-membrane and inner crista. Further analysis showed impaired respiratory complexes activities of C-Mito from HF mice (C-MitoHF) accompanied by oxidative damage. C-Mito entered ECs, instead of glial cells and neurons in the SFO of HF mice. C-MitoHF increased the level of ROS and cytosolic free double-strand DNA (dsDNA), and activated cGAS in cultured brain endothelial cells. Furthermore, C-MitoHF highly expressed DHODH, which interacted with cGAS to facilitate endothelial cGAS activation. C-MitoHF aggravated endothelial inflammation, microglial/astroglial activation, and neuronal sensitization in the SFO of HF mice, which could be ameliorated by cGAS KD in the ECs of the SFO. Further analysis showed C-MitoHF failed to exacerbate sympathoexcitation and myocardial sympathetic hyperinnervation in cGAS KD HF mice. C-MitoHF promoted myocardial fibrosis and hypertrophy, and cardiac systolic dysfunction in HF mice, which could be ameliorated by cGAS KD. Conclusion: Collectively, we demonstrated that damaged C-MitoHF highly expressed DHODH, which promoted endothelial cGAS activation in the SFO, hence aggravating the sympathoexcitation and myocardial injury in HF mice, suggesting that C-Mito might be the novel therapeutic target for sympathoexcitation in HF. Highlights: Circulating mitochondria from HF mice (C-MitoHF) were respiratory impaired and oxidatively damaged. C-MitoHF entered the endothelial cells of the SFO in HF mice, promoted ROS accumulation and cytosolic free dsDNA release, and further activated endothelial cGAS in the SFO. Dihydroorotate dehydrogenase (DHODH), a mitochondrial redox regulator, was highly expressed in C-MitoHF, which directly interacted with cGAS in the endothelial cells to promote cGAS activation. C-MitoHF-inducing endothelial cGAS activation in the SFO aggravated sympathoexcitation and myocardial remodeling in HF mice. [ABSTRACT FROM AUTHOR]

The adequate assessment of the spontaneous combustion and oxidation characteristics of coking coal can help to reduce its spontaneous combustion potential. In this study, the natural ignition period of the Hex coking coal seam at Ping Coal was calculated based on the programmed-temperature-rise test and the thermal property parameters measured during the spontaneous combustion of the coal. Typical gas concentrations were measured at different oxygen concentrations and coal particle sizes to investigate the changes in the oxygen, carbon–oxygen, and hydrocarbon gas concentrations during the low-temperature oxidation of the coking coal and to determine the indicator gases at different oxidation stages. The following results were obtained: The minimum critical oxygen concentration required for spontaneous ignition was 8%, and fire prevention measures should be implemented below 200 °C. When the temperature of the coal sample reaches 50–60 °C, the rates of CO and CO2 production increase, and when the temperature of the coal sample reaches 100–120 °C, the spontaneous combustion and oxidation of the coal generates alkane gas, in which the coal particle size has a negligible effect on the concentration of each generated gas. CO and C2H4 were selected as the indicator gases for different coking coal oxidation stages, and C2H6 and the C2H4/C2H6 ratio were used as secondary indicators to assist in the analysis. Utilizing the enhanced mathematical model for the shortest spontaneous combustion period of coal seams, in conjunction with a programmed-temperature test device, experimental calculations were conducted to determine the adiabatic spontaneous combustion period. The results indicate that the natural ignition period for the Hex coking coal seam at Ping Coal is approximately 60 days, representing a brief timeframe, and the coal seam is characterized by a high risk of spontaneous combustion. [ABSTRACT FROM AUTHOR]

Abstract: Traumatic aortic-left ventricle tunnel through interventricular septum was particularly a rare event that has never previously been described. A 58-year-old male, with a history of blunt thoracic trauma caused by falling from height, was admitted to our institute for effort dyspnea. Chest computed tomography scan showed subaortic interventricular septal lumen communicating with coronary sinus and left ventricular outflow tract (LVOT). Transthoracic echocardiography revealed a shuttle flow from coronary sinus to LVOT bypassing aortic annulus during diastole. Operation examination found partial aortic annulus avulsion outside right coronary cusp involving superior interventricular septum dissection forming a tunnel breakthrough into left ventricular outflow tract. Both aortic orifice and LVOT orifice of the tunnel were closed with running Prolene suture and right coronary cusp annulus was fastened to aortic root with intermittent mattress suture. The postoperative course was uneventful. Echocardiography confirmed complete closure of the tunnel with residual trivial to mild aortic regurgitation during 1-month follow-up. [Copyright &y& Elsevier]

Background: There are 30%–40% of patients with dilated cardiomyopathy (DCM) having genetic causes, among which Lamin A and C gene (LMNA) mutation is the second most frequent DCM-related mutation, and Lamin A/C may be involved in the pathogenesis of DCM through the regulation of gene transcription or the direct effect of cell structure. Methods: Echocardiography and electrocardiogram were used to diagnose DCM and arrhythmia in a DCM family. Then, linked mutations on LMNA were screened out by high-throughput sequencing and verified by Sanger sequencing in all research individuals. Meanwhile, Human Genome Variation Society (HGVS) and Integrative Genomics Viewer (IGV) were used to analyse the characteristics of the mutated Lamin A/C protein. Finally, mutated-type and wild-type LMNA plasmid was transfected into AC-16 cardiomyocytes with the form of a lentivirus vector, and its effect on nucleus and actin was studied by immunofluorescence detection. Results: In this study, we found a new frame-shifted mutation of LMNA (p.Ser414Alafs*66) linked with another point mutation from a DCM family by using High-throughput sequencing, and this deletion mutation led to a truncation of Lamin A/C. By analysing the clinical characteristics of this DCM family, we found that all DCM patients with arrhythmia were carriers of this co-segregation mutation. In the cytological experiment, we found that the mutated-type transfections showed weaker fluorescent intensities on both actin and cell nucleus. Conclusions: A co-segregation mutation of LMNA (Point mutation chr1 156107548 c.1712 G>A and truncated frame-shifted mutation chr1 156106086 c.1240delA) was found from a DCM family, and this type of mutation could participate in the pathogenesis of DCM by affecting the expression of actin. [ABSTRACT FROM AUTHOR]

Background. Pulmonary hypertension is a well-known risk factor for hemodynamic instability after heart transplantation. However, it remains unclear whether a mild elevation of pulmonary artery systolic pressure (PASP) is associated with higher risks of graft dysfunction and resultant extracorporeal membrane oxygenation (ECMO) support. Methods. From 2016 to 2021, 102 adult recipients undergoing orthotopic heart transplantation at our institution were investigated (mean age, 48.5 ± 13.2 years; 22.5% female). This study cohort was stratified into 3 groups based on the PASP measured by right heart catheterization before surgery: >50 mmHg, 35–50 mmHg, and <35 mmHg. The primary end point was ECMO support after procedure. Results. ECMO was implemented in 24 (23.5%) patients due to difficult weaning from cardiopulmonary bypass or cardiac low output in the intensive care unit, which was likely to be associated with higher mortality (P = 0.053). Age, gender, comorbidities, preoperative medications, and graft ischemia time were comparable across the 3 groups. The use of ECMO was significantly more common in patients with baseline PASP >50 mmHg (11/36, 30.6%) and 35–50 mmHg (12/38, 31.6%), while only 1 (3.6%) patient with baseline PASP <35 mmHg required ECMO support after transplant (P = 0.007). Multivariate logistic models demonstrated that PASP (odds ratio = 2.34; P = 0.028) and cardiopulmonary bypass time (odds ratio = 1.01; P < 0.001) were independent risk factors for postoperative ECMO. Conclusions. A mild elevation of pretransplant PASP (e.g., 35–50 mmHg) is related to low cardiac output and subsequent ECMO after heart transplantation, for which prompt administration of vasodilators before transplant may be protective. [ABSTRACT FROM AUTHOR]

Background : Acute rejection (AR) after organ transplantation results in transplant arteriosclerosis (TA). Endothelial progenitor cells (EPCs) are involved in tissue repair and blood vessel formation but are suspected to be a cause of TA. Methods : In this study, we introduced a syngeneic and allogeneic abdominal aortic transplant model with C57BL/6 and BALB/c mice. Syngeneic and allogeneic grafts were histopathologically analyzed after transplantation. Bone marrow-derived EPCs were injected into transplant model animals to observe their distribution and temporal concentration changes. Changes of vascular endothelial growth factor receptor 1 (VEGFR-1), phosphorylated VEGFR-1 (pVEGFR-1), VEGFR-2, pVEGFR-2, protein kinase B (Akt), pAkt, extracellular signal-regulated kinase 1 (Erk1), pErk1 levels in EPCs upon VEGF 165 and the VEGFR inhibitor Vandetanib exposure were analyzed in vitro with western blotting. Results : In the allogeneic transplant group, two weeks after transplantation, formations of new intima layers could be observed, and its proliferation gradually increased to four and six weeks post-transplantation ( p < 0.05), accompanied by significant arterial stenoses. Exogenous EPCs mainly localized to the damaged sites of the transplant arteries. In vivo , Vandetanib caused a significant dose dependent decrease of transplant hyperplasia ( p < 0.05) and inhibited VEGF related proliferation, migration and adhesion of EPCs. Conclusion : Vandetanib treatment can reduce arteriosclerosis induced by abdominal aorta transplantation by blocking VEGFRs in EPCs. [ABSTRACT FROM AUTHOR]

Objective: Modified Morrow procedure is the gold standard of surgical intervention for hypertrophic obstructive cardiomyopathy (HOCM). However, there are certain cases without complete relief of obstruction through trans‐aortic approach, we, therefore, described an unusual technique. We aimed to retrospectively analyze this series of patients to reveal its safety and efficiency. Methods: We retrospectively analyzed a total of 247 consecutive HOCM patients in our center from January 2016 to December 2019. Sixteen of them who underwent enlargement of left ventricular outflow tract (LVOT) using an autologous pericardial patch for anterior mitral valve leaflet and septal myectomy through trans‐mitral approach were recruited in this study. Baseline characteristics, perioperative data, and the outcomes were studied. Results: Of the 16 patients, there was no operative mortality. No permanent pacemaker implantation and ventricular septal defects formation were observed. The peak pressure gradient of LVOT decreased from 97.56 ± 23.81 mmHg to 7.56 ± 2.13 mmHg (p <.01) after operation and 10.19 ± 2.93 mmHg (p <.01) 3 months later. The average septal thickness decreased from 18.38 ± 3.56 mm to 10.00 ± 2.74 mm (p <.01). During a mean follow‐up of 34.25 ± 12.85 months (range, 15–57), no patient required cardiac reoperation. At the last follow up, the mean peak pressure gradient of LVOT was 10.12 ± 2.03 mmHg and no patient had more than moderate mitral regurgitation. Conclusion: Enlargement of LVOT using an autologous pericardial patch for anterior mitral valve leaflet and septal myectomy through trans‐mitral approach is feasible and reliable for the treatment of certain types of HOCM cases. [ABSTRACT FROM AUTHOR]

Background: Redo isolated tricuspid valve surgery is associated with a high morbidity and mortality, and its optimal timing remains controversial. Hence, here we reviewed the early and midterm results of simplified, minimally invasive, beating-heart technique for redo isolated tricuspid valve surgery in patients at high risk.Methods: A total of 32 consecutive patients underwent a redo isolated tricuspid valve surgery using minimally invasive, beating-heart technique through a right lateral thoracotomy in our center between June 2016 and April 2020. The mean age of patients was 57.4 ± 8.3 years, and 18 patients (56.3%) were women. The mean preoperative EuroSCORE was 7.8 ± 1.4 (range: 6-11). Follow-up was 87.1% complete, with a mean duration of 26.3 ± 12.3 months.Results: Both in-hospital and 30-day mortalities were 3.1%. Tricuspid valve replacement with bioprosthesis was performed in 30 patients (93.8%), and the remaining two patients (6.2%) underwent tricuspid repair (annuloplasty and leaflet reconstruction). The mean cardiopulmonary bypass time was 81.5 ± 29.0 min. The overall in-hospital duration and intensive care unit (ICU) times were 13.6 ± 7.6 days and 4.1 ± 2.8 days, respectively. Postoperative complications included prolonged ventilation in six patients (18.8%), acute kidney injury in three patients (9.4%), and neurologic event, wound infection, or permanent third-degree atrioventricular block, in one patient (3.1%) each. A total of 96.9% patients were discharged uneventfully. Four patients were lost to follow-up; there were no midterm deaths in patients who were followed up.Conclusions: Simplified, minimally invasive, beating-heart technique for redo tricuspid valve surgery is both feasible and safe, and the early and midterm results are excellent. [ABSTRACT FROM AUTHOR]

Background: This study aimed to analyze the mortality and morbidity of patients undergoing open aortic arch reconstruction for acute type A aortic dissection.Methods: Between September 2005 and January 2012, 267 consecutive patients underwent open aortic arch reconstruction for acute type A aortic dissection at our center. The mean age was 51.2 ± 10.0 years, and 200 patients were male. Sixty-three and 184 patients underwent hemiarch replacement and total arch replacement, respectively, whereas the remaining 20 patients underwent single- or triple-branched stent graft implantation. Long-term mortality was estimated by Kaplan-Meier method.Results: The in-hospital and operative mortality rates within 30 days were 11.2 % and 8.2 %, respectively. The cardiopulmonary bypass, myocardial ischemic, and antegrade cerebral perfusion times were 150.2 ± 43.3, 71.9 ± 33.2, and 33.6 ± 14.4 min, respectively. The overall in-hospital and intensive care unit durations and mean ventilation time were 23.9 ± 18.4 and 9.5 ± 12.7 days and 122.7 ± 183.4 h, respectively. We observed new postoperative permanent neurological dysfunction in 29 patients and temporary neurological dysfunction in 17 patients. The mean follow-up duration was 52.4 ± 27.9 months; 76.4 % of patients completed follow-up and 143 remained alive. Overall long-term survival was 82.2 % at 5 years.Conclusions: The open aortic arch reconstruction technique for acute type A dissection carries a relatively high in-hospital mortality risk, although the late results are encouraging. Patients with an advanced age or impaired renal function may opt for endovascular or modified single- or triple-branched stent graft implantation therapy. [ABSTRACT FROM AUTHOR]

Background: The primary experience of open triple-branched stent graft placement for acute aortic arch dissection was reported.Methods: Between January 2011 and October 2011, 13 well-selected patients (mea age, 46±8.2 years; approximate range, 30~58 years) with acute aortic arch dissection underwent open triple-branched stent graft placement for total arch reconstruction. The triple-branched stent graft was a branched 1-piece graft consisting of a self-expandable nitinol stent and polyester vascular graft fabric (Yuhengjia Sci Tech Corp Ltd, Beijing, China). During hypothermic circulatory arrest, through the transverse incision of the ascending aorta, the main graft of the triple-branched stent graft was inserted into the true lumen of the arch and proximal descending aorta, and then each sidearm graft was positioned one by one into the aortic branch. Once the main graft and sidearm grafts were properly positioned, the restraining strings were withdrawn and then the main graft and sidearm grafts were deployed. Enhanced electric beam computed tomography was performed in each patient before discharge to evaluate the postoperative time course of the residual false lumen.Results: Open triple-branched stent graft placement was technically successful in all patients. The mean cardiopulmonary bypass time, aortic cross-clamp time and arrest time were 138.40±47.75 min, 70.60±28.94 min and 28.60±12.48 min, respectively. All patients were discharged from hospital. Their computed tomographic scans postoperatively showed that all stent grafts were fully opened and not kinked, there was no blood flow surrounding the triple-branched stent graft.Conclusion: Open triple-branched stent graft placement is a new effective technique for total arch reconstruction in acute arch dissection. [ABSTRACT FROM AUTHOR]

Mitral Valve Aneurysm (MVA) is rarely reported and occurs most in association with infective endocarditis of the aortic valve. In our case, the 46-yr-old Chinese man was referred to our hospital with dyspnea and orthopnea. Transesophageal echocardiography during operation revealed a localized, thin-walled saccular structure in the anterior leaflet that bulged into the left atrium, and severe mitral and aortic regurgitation. Aortic valve was replaced with mechanical prostheses and mitral valve was repaired with autologous pericardium. Transesophageal echocardiography during operation and transthoracic echocardiography 3 months later showed mild regurgitation. [ABSTRACT FROM AUTHOR]

Background: Acute type A aortic dissection (TAAD) is a life-threatening vascular disease. Smooth muscle cells (SMCs) are the main composition of aortic media and dysfunction of SMCs may lead to acute TAAD. The aim of this work was to investigate whether the SMCs of acute TAAD could be isolated and cultured for further research.Methods: TAAD tissues were obtained from acute TAAD patients who underwent emergent surgical treatment. A simple and economical technique of collagenase digestion method was used to isolate and culture human SMCs. Confocal laser scanning microscopy was applied to identify SMC phenotypes. Purity of isolated and cultured SMCs was analyzed with flow cytometry and fluorescence microscopy respectively.Results: The purity of isolated SMCs was 78.2%, including α-smooth muscle cell actin positive 13.9%, calponin positive 35.0% and double positive 29.3%. For cultured SMCs, abundant expression of α-smooth muscle cell actin was observed universally under fluorescence microscope. Confocal laser scanning microscope testified that cultured cells were double positive of α-smooth muscle actin and calponin.Conclusions: This is the first report of successful culture of SMCs isolated from human acute TAAD tissues. Living human SMCs of acute TAAD provides us with a new method for studying formation of acute TAAD. [ABSTRACT FROM AUTHOR]

Background: This study aimed to retrospectively investigate our experience of surgical treatment for acute type A aortic dissection in patients older than 70 years.Methods: From September 2005 to January 2012, eleven patients who were older than 70 years underwent surgical treatment for type A aortic dissection at our center and were included in this study. Total arch replacement was performed in three patients, seven patients underwent subtotal arch replacement and one with single-branched stent graft implantation. One patient underwent a valve-sparing (David) procedure while another underwent a concomitant aortic valve replacement (Wheat procedure). One patient required coronary artery bypass grafting. All operations were performed under deep hypothermic circulatory arrest and selective antegrade cerebral perfusion.Results: There was one in-hospital death (9.1%) and no operative mortality within 30 days. Cardiopulmonary bypass time, myocardial ischemic time and antegrade cerebral perfusion time accounted for 151.4 ± 33.5 minutes, 68.5 ± 41.4 minutes and 30.3 ± 12.9 minutes, respectively. Overall in-hospital duration, intensive care unit (ICU) time and mean ventilation time were 40.9 ± 40.3 days, 16.5 ± 22.5 days and 90.5 ± 139.4 hours, respectively. New postoperative permanent neurological dysfunction and temporary neurological dysfunction were observed in one patient (9.1%) and in three patients (27.3%), respectively. Mean follow-up was 49.0 ± 19.9 months and nine patients are still alive, one patient died of cancer after 24 months postoperation.Conclusions: Surgical management for acute type A dissection in patients older than 70 years is a safe alternative with acceptable risk of death and the early and late results are satisfactory. [ABSTRACT FROM AUTHOR]