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In solids, chemical short-range order (CSRO) refers to the self-organization of atoms of certain species occupying specific crystal sites. CSRO is increasingly being envisaged as a lever to tailor the mechanical and functional properties of materials. Yet quantitative relationships between properties and the morphology, number density, and atomic configurations of CSRO domains remain elusive. Herein, it is showcased how machine learning-enhanced atom probe tomography (APT) can mine the near-atomically resolved APT data and jointly exploit the technique's high elemental sensitivity to provide a 3D quantitative analysis of CSRO in a CoCrNi medium-entropy alloy. Multiple CSRO configurations are revealed, with their formation supported by state-of-the-art Monte-Carlo simulations. Quantitative analysis of these CSROs allows establishing relationships between processing parameters and physical properties. The unambiguous characterization of CSRO will help refine strategies for designing advanced materials by manipulating atomic-scale architectures.
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To retrospectively analyze the clinical efficacy of an innovative mitral valvuloplasty strategy in the treatment of mitral regurgitation in children. From January 2018 to December 2022, 140 patients undergoing surgical treatment for mitral regurgitation in our hospital were enrolled. Ninety patients underwent three-step standardized pediatric mitral valvuloplasty (group A) and 50 patients underwent simple annuloplasty (group B). The incidence of primary and secondary study endpoint was compared between the two groups, and the independent risk factors for the primary study endpoint were determined. Our primary study endpoint was a composite endpoint of postoperative functional mitral failure, postoperative heart failure, transplantation, and/or mortality. Secondary end points were defined as perioperative complications. During the follow-up period, there was no all-cause death. Primary endpoint events occurred in 22 patients, including 12 patients in group A and 10 patients in group B. There was no significant difference in the incidence of primary and secondary endpoint events between the two groups. Multivariate Cox proportional hazards regression analysis showed that younger age and residual mitral regurgitation at discharge were independent risk factors for the primary endpoint events, while type of MV repair was not an independent risk factor. Subgroup analysis based on age showed that primary endpoint events occurred in 4 patients in group A and 7 patients in group B in patients < 1 year old. The incidence of primary endpoint events in group A was lower than that in group B (6.06% vs. 20.59%, P = 0.041). In patients ≥ 1 year old, the primary endpoint event occurred in 8 cases in group A and 3 cases in group B. There was no significant difference in the incidence of primary endpoint events between groups A and B (33.33% vs. 18.75%, P = 0.312). The degree of mitral regurgitation at discharge was significantly improved compared with that before operation in both groups (P < 0.001), and the degree of mitral regurgitation at the last follow-up was not significantly worse than that at discharge (P = 0.090). The mid-term results of mitral valvuloplasty for mitral regurgitation in children are encouraging. The perioperative recovery and postoperative outcomes of three-step standardized mitral valvuloplasty in children are not inferior to those of annuloplasty alone. Three-step standardized pediatric mitral valvuloplasty has better postoperative outcomes than simple mitral annuloplasty, especially for patients younger than 1 year old. Children with residual mitral regurgitation at discharge should be followed up regularly to be alert to the occurrence of poor prognosis.
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We conducted a retrospective review of patients who underwent valved homograft conduits (VHC) for right ventricular outflow tract (RVOT) reconstruction at our center. Long-term outcomes were analyzed, and risk factors affecting the long-term durability of VHC were explored. Kaplan-Meier survival curves were used to evaluate survival, freedom from VHC reintervention, and freedom from VHC dysfunction. Multivariate Cox proportional hazards regression model was used to analyze the risk factors for late VHC dysfunction. A total of 290 patients who underwent VHC for RVOT reconstruction in our center were enrolled. Seven patients occurred early death, all of which were in the non-Ross group. Two hundred and sixty-five patients were followed up for 85 (0.3-176.0) months. Six patients occurred late death, all in the non-Ross group. Six patients underwent VHC reintervention. During the follow-up period, 52 patients developed VHC dysfunction. Freedom from VHC dysfunction was higher in the Ross group than in the non-Ross group in the whole cohort. Multivariate Cox regression analysis showed that age < 6 years and non-Ross operation were independent risk factors for VHC dysfunction. Freedom from VHC dysfunction was higher in the Ross group than in the non-Ross group in patients younger than 6 years of age at surgery. However, there was no significant difference in freedom from VHC dysfunction between the two groups in patients older than 6 years. Long-term outcomes of VHC for RVOT reconstruction are satisfactory. Age < 6 years and non-Ross operation are independent risk factors for VHC dysfunction. The long-term survival rate and durability of VHC in Ross group were better than those in non-Ross group. The advantage of long-term durability of VHC in the Ross group was mainly reflected in patients aged < 6 years at operation.
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In recent years, with advancements in surgical techniques and the widespread utilization of extracorporeal cardiac assist devices such as extracorporeal membrane oxygenation (ECMO), the treatment outcomes for ALCAPA (Anomalous left coronary artery from the pulmonary artery) have demonstrated significant improvements. However, the surgical indications and methods of ALCAPA, especially the surgical methods of ALCAPA with intramural coronary artery, and whether to treat MR at the same time are still controversial. The long-term prognosis remain discouraging simultaneously, with significant variations in outcomes across different centers. The present review specifically addresses these aforementioned concerns. This article reviews the pathophysiology and classification, diagnosis, indications, surgical strategy and prognosis of ALCAPA. We believe that this review will provide some reference for future researchers and provide new ideas for reducing the adverse prognosis of children with congenital heart disease in future.
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Mercury (Hg), especially methylmercury (MeHg), is a pervasive contaminant that poses significant risks to birds occupying high trophic levels. However, we have little knowledge about the mercury exposure and its risks for birds in Poyang Lake basin, China. Therefore, during 2020-2021, we investigated MeHg concentrations in breast feathers of wintering migratory birds (n = 430 from 43 species belonging to 9 orders) in Poyang Lake Nanji Wetland and Jiangxi Nanfengmian National Nature Reserve, China. MeHg concentrations in breast feathers varied greatly by species, foraging guilds and taxonomic orders, among which the highest concentration was detected in great egret (8849 ± 5975 ng g-1 dw). Comparing with studies worldwide, high MeHg concentrations in feathers of Ardeidae from Pelecaniformes were found in this area. Moreover, herons migrating between northern and southern China had lower MeHg concentration than residents in southern China related to habitat Hg. Considering the applicability and sensitivity of the equations for the transformation of MeHg concentrations in feathers to blood-equivalent total Hg (THg) values, method CJ that the equation based on songbirds was used for the transformation of the songbirds and the equation based on seabirds for the others performed better than other three for risk assessment of bird Hg in this study. 23.1% of birds from Poyang Lake were at risk of Hg exposure based on the method CJ. Carnivorous birds from Pelecaniformes had the highest risk levels, with 37.2% categorized as no risk (≤200 ng g-1 ww), 48.9% as low risk (200-1000 ng g-1 ww), 11.1% as moderate risk (1000-3000 ng g-1 ww), 1.1% as high risk (3000-4000 ng g-1 ww), and 1.7% as severe risk (>4000 ng g-1 ww). These risks suggest long-term monitoring and further advanced studies about freshwater waterbirds Hg exposure is necessary.
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This study sought to find the risk factors of postoperative pulmonary venous obstruction (PVO), PVO-related reintervention, and postoperative mortality, determine the relationship between pulmonary venous confluence (PVC) morphology and the clinical outcomes, and provide the basis for the selection of the optimal surgical strategy for infracardiac total anomalous pulmonary venous connection (TAPVC). From December 2009 to December 2023, 101 patients with infracardiac TAPVC undergoing surgical repair in our institution were included [Conventional surgery (CS) group, n = 73; Sutureless technique (ST) group, n = 28]. The Kaplan-Meier curve was used to demonstrate the survival estimates. The Cox proportional hazard model was used to identify risk factors for primary endpoints. There were 8 in-hospital deaths and 4 late deaths. The survival rates at 1, 5, and 10 years were 88.8%, 87.6%, and 87.6%, respectively, in the whole cohort. Multivariable analysis showed that prolonged cardiopulmonary bypass (CBP) time was associated with overall mortality and Y-shaped PVC has a trend for a higher mortality rate. Postoperative PVO occurred in 27 patients. Freedom from postoperative PVO at 1, 5, and 10 years were 81.8%, 69.9%, and 69.9%, respectively. Y-shaped PVC and preoperative PVO were incremental risk factors for PVO, but ST repair was a protective factor. Sixteen patients underwent PVO-related reintervention. Y-shaped PVC was the only independent risk factors for PVO-related reintervention while ST repair was a protective factor. Sutureless technique can achieve satisfactory outcomes for infracardiac TAPVC repair. Compared with CS repair, ST repair is significantly associated with decreased postoperative PVO and PVO-related reintervention. Y-shaped PVC is associated with a higher risk of PVO, PVO-related reintervention, and mortality, respectively. Patients with preoperative PVO are more likely to develop postoperative PVO.
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The conventional surgery (CS) of supracardiac total anomalous pulmonary venous connection (TAPVC) is not always effective particularly in the setting of complex anatomy such as the mixed variety of TAPVC. This study aimed to analyze the outcomes of surgical treatment of supracardiac TAPVC and determine the optimal strategy. From December 2009 to December 2023, patients with supracardiac TAPVC undergoing surgical repair in our institution were included. The Kaplan-Meier curve was used to demonstrate the survival estimates. The Cox proportional hazard model was used to identify risk factors for death and postoperative pulmonary venous obstruction (PVO). One hundred and eighty-three patients with supracardiac TAPVC underwent surgical repair [CS group, n = 102; modified L-shaped incision technique (MLIT) group, n = 81]. There were 8 in-hospital deaths and 16 late deaths. The survival rates at 1, 5, and 10 years were 89.0%, 85.0%, and 85.0%, respectively in the whole cohort. Multivariable analysis showed that lower weight (P = 0.031), prolonged CBP time (P = 0.007), preoperative PVO (P = 0.020), and emergency surgery (P = 0.001) were incremental risk factors for death, but using the MLIT was a protective factor for death (p = 0.028). In the CS group, patients with emergency operation had worse survival than patients with elective surgery (P < 0.001). However, in the MLIT group, patients with emergency operation had comparable survival to patients with elective surgery (P = 0.332). Postoperative PVO occurred in 30 patients. Fourteen patients underwent PVO-related reintervention. In the whole cohort, freedom from postoperative PVO at 1, 5, and 10 years were 87.5%, 80.6%, and 80.6%, respectively. Patients who underwent MLIT repair had a lower incidence of postoperative PVO (P < 0.001), and PVO-related reintervention (P = 0.019). Neonates(P = 0.033), aortic cross-clamp time (P = 0.012), preoperative PVO (P = 0.002), and using the CS (P = 0.005) were associated with postoperative PVO. In terms of postoperative PVO, MLIT had a protective effect compared with CS. In the CS group, Infant and Children patients had better freedom from postoperative PVO than Neonate patients (P < 0.001). However, in the MLIT group, Neonate patients had comparable freedom from postoperative PVO to Infant and Children patients (P = 0.332). The MLIT can achieve satisfactory outcomes for supracardiac TAPVC repair. Compared with CS, the MLIT was significantly associated with decreased death, postoperative PVO, and PVO-related reintervention. It is especially significant in improving the survival rate of patients undergoing emergency surgery and reducing the incidence of postoperative PVO in neonatal patients.
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Various surgical techniques have been introduced to treat supravalvular aortic stenosis (SVAS). However, there is no consensus on the optimal approach. This study aimed to analyze the outcomes of surgical treatment of SVAS and determine the optimal strategy. The Kaplan-Meier curve was used to demonstrate the survival estimates. The Cox proportional hazard model was used to identify risk factors for residual aortic stenosis and residual stenosis-related reintervention. From December 2008 to December 2023, 98 patients with SVAS undergoing surgical repair in our institution were included [McGoon group, n = 62; Doty group, n = 36]. There were 2 in-hospital deaths and 1 late death. The survival rates at 1, 5, and 15 years were 98.0%, 96.7%, and 96.7%, respectively in the whole cohort. Residual aortic stenosis occurred in 18 patients. Multivariable analysis showed that preoperative gradient ≥ 90 mmHg (P = 0.002) and Williams syndrome (P = 0.002) were incremental risk factors for residual aortic stenosis, but surgical technique (P = 0.579) was not a risk factor for residual aortic stenosis. In the McGoon group, patients with diffuse type had worse freedom from residual aortic stenosis than patients with discrete type (P = 0.007). However, in the Doty group, patients with diffuse type had comparable freedom from residual aortic stenosis to patients with discrete type (P = 0.911). Residual stenosis-related reintervention occurred in 15 patients. Fifteen patients all underwent residual aortic stenosis-related reintervention. Of 15 patients, 6 patients also underwent residual pulmonary stenosis-related reintervention. On multivariate analysis, Williams syndrome (P < 0.001), preoperative sinotubular junction (STJ) z-score < - 3.5 (P = 0.051), and Doty repair (P = 0.033) were found to be independent risk factors associated with residual stenosis-related reintervention. In the whole cohort, freedom from residual stenosis-related reintervention at 1, 5, and 15 years were 97.8%, 89.3% and 76.1%, respectively. Surgical repair of SVAS can be safely achieved using different techniques, with similar long-term mortality. Compared with McGoon repair, Doty repair was significantly associated with decreased residual aortic stenosis rates in patients with diffuse-type SVAS. Patients with preoperative gradient ≥ 90 mmHg or Williams syndrome are more prone to residual aortic stenosis. Surgical technique was not associated with residual aortic stenosis rates. Williams syndrome, preoperative STJ z-score < - 3.5, and Doty repair are associated with higher residual stenosis-related reintervention rates.
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OBJECTIVES: The clinical data of patients with total anomalous pulmonary venous connection who underwent repair in our centre in the past 13 years were reviewed. In this study, we systemically reviewed our experience in the optimal surgical strategy for patients with total anomalous pulmonary venous connection, aiming to provide evidence for clinical decision-making. METHODS: From January 1, 2009, to December 31, 2021, 122 patients undergoing surgical treatment for total anomalous pulmonary venous connection in our hospital were enrolled. Among them, 18 patients with single ventricle repair were excluded from the study. Multivariate analysis was used to determine the risk factors for early and late death and the risk factors for pulmonary vein obstruction. RESULTS: There were 64 males and 40 females. The median age at surgery was 107 days (range, 25 days-788 days), the median weight at surgery was 4.8 kg (range, 3 kg-22 kg), and the median follow-up was 59 months (range, 0-150 months). Seven patients died early after surgery and six died late after discharge. Multivariable analysis indicated that prolonged cardiopulmonary bypass time was the only independent risk factor for early postoperative mortality. Multivariate analysis did not identify risk factors for late death. Emergency surgery, preoperative moderate and severe pulmonary hypertension, and prolonged cardiopulmonary bypass time were independent risk factors for postoperative pulmonary vein obstruction. CONCLUSION: Early and long-term late outcomes of repair in patients with total anomalous pulmonary venous connection have been encouraging. Postoperative pulmonary vein obstruction remains a major problem for specialists worldwide. Pulmonary vein obstruction should be considered in children with preoperative emergency surgery, moderate to severe pulmonary hypertension and prolonged cardiopulmonary bypass time, and regular follow-up is necessary.
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Precipitates are crucial for crafting mechanically strong metallic materials. In this work, we report the dislocation cutting of B2 (ordered body-centered cubic) nanoprecipitates, typically considered nonshearable intermetallics, in a lightweight compositionally complex steel during cryogenic tensile loading. Shearing is enabled by the high strength level for dislocation glide within the austenitic matrix, attributed to the substantial strengthening from subnanoscale local chemical ordering zones and the pronounced solid solution strengthening from the multiprincipal elements in the matrix. This mechanism not only harnesses the intense strengthening and strain hardening provided by otherwise impenetrable brittle nanoprecipitates but also introduces ductility through their sequential shearing with ongoing deformation. Our steel thus showcases ultrahigh cryogenic tensile strength up to 2 gigapascal at a remarkable tensile elongation of 34%. This study reveals a new strategy for designing high-performance structural materials.
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OBJECTIVES: The clinical data of patients with subaortic stenosis who underwent surgical treatment in our centre in the past 12 years were reviewed. The short-term and long-term clinical outcomes were analyzed, and the long-term outcomes of different surgical methods for subaortic stenosis were compared to determine the optimal surgical treatment strategy for subaortic stenosis. METHODS: From December 2010 to December 2022, 90 patients undergoing surgical treatment for subaortic stenosis in our hospital were enrolled. There were 55 males and 35 females with a median age of 72 (46,132) months and an average surgical weight of (21.35 ± 15.84) kg. According to the operation method, 90 patients were divided into group A (50 patients with simple subaortic membrane resection) and group B (40 patients with subaortic membrane and muscle resection or modified Konno procedure). RESULTS: There were three early deaths (3.33%). One late death occurred in group B. There was no significant difference in long-term survival rate between the two groups (p = 0.904). The preoperative left ventricular outflow tract pressure gradient in group B was (91.56 ± 36.98) mm Hg, which was higher than that in group A(51.13 ± 36.04)mm Hg(p < 0.001). There was no significant difference in immediate postoperative left ventricular outflow tract pressure gradient between group B [(5.44 ± 8.43) mm Hg] and group A [(7.82 ± 13.44) mm Hg] (p = 0.343). In the long-term follow-up, left ventricular outflow tract pressure gradient in group B was (5.86 ± 9.53) mm Hg, which was not statistically significant compared with group A (8.83 ± 14.52) mm Hg (p = 0.294). Eleven patients with moderate or greater aortic regurgitation (group A/group B: 3/8) underwent simultaneous aortic valvuloplasty. In group B, moderate or greater aortic regurgitation was significantly improved immediately after operation (p = 0.013) and was not significantly aggravated in long-term follow-up (p = 0.083), and there was no significant improvement in group A after operation and long-term follow-up. CONCLUSIONS: According to the different anatomical lesions of left ventricular outflow tract, the individualised surgical treatment strategy for patients with subaortic stenosis can achieve good long-term outcomes. The long-term survival rate and freedom from reoperation due to late left ventricular outflow tract obstruction after simple subaortic membrane resection and extended left ventricular outflow tract resection are comparable. For patients with moderate or greater aortic regurgitation before extended left ventricular outflow tract resection, simultaneous aortic valvuloplasty is beneficial to improve postoperative aortic valve function.
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OBJECTIVES: The aims of this study were to evaluate the 16-year experience with arterial switch operation at Beijing Children's Hospital and to determine early and late mortality and late morbidity, to explore risk factors for late complications and reintervention, and finally to evaluate whether the neoaortic sinotubular junction reconstruction technique reduces late complications of arterial switch operation. METHODS: The clinical data of 185 patients with transposition of the great arteries who underwent arterial switch operation in Beijing Children's Hospital from January 2006 to January 2022 and 30 patients who underwent modified arterial switch operation with neoaortic sinotubular junction reconstruction technique in Fuwai Hospital during the same period were retrospectively analysed. Propensity score matching was also used to match the neoaortic sinotubular junction reconstruction patients in Fuwai Hospital with 30 non-neoaortic sinotubular junction reconstruction patients in Beijing Children's Hospital. RESULTS: There were 13 early deaths (7.03%) and five late deaths (3.01%). Nineteen patients (11.45%) developed new aortic valve regurgitation and 28 patients (16.87%) developed aortic root dilation. Late right ventricular outflow tract obstruction occurred in 33 patients (19.88%). Late reintervention occurred in 18 cases (10.84%). Multivariate analysis showed that aorto-pulmonary diameter mismatch, previous pulmonary artery banding, and mild moderate or above new aortic valve regurgitation at discharge were independent risk factors for late new aortic valve regurgitation and aortic root dilation. Low surgical weight was an independent risk factor specific to new aortic valve regurgitation, and bicuspid native pulmonary valve was an independent risk factor specific to aortic root dilation. Older surgical age and aortic root dilation were independent risk factors for late right ventricular outflow tract obstruction. Older surgical age, operation before 2014, late right ventricular outflow tract obstruction, and late aortic root dilation were independent risk factors for late intervention. Propensity score matching showed that new aortic valve regurgitation and aortic root dilation were not followed up in the neoaortic sinotubular junction reconstruction group, while seven cases of aortic root dilation and five cases of new aortic valve regurgitation occurred in the non-neoaortic sinotubular junction reconstruction group, respectively, and the differences were statistically significant (P = 0.003; P = 0.015). CONCLUSIONS: The increased incidence of new aortic valve regurgitation, aortic root dilation, and right ventricular outflow tract obstruction as children age is a major concern outcome in the future and may mean more late reintervention. neoaortic sinotubular junction reconstruction technique may reduce the incidence of new aortic valve regurgitation and aortic root dilation, and improve the late prognosis of arterial switch operation. Careful follow-up of neo-aortic valve and root function is imperative, especially in patients with aorto-pulmonary diameter mismatch, previous pulmonary artery banding, mild new aortic valve regurgitation at discharge, low surgical weight, and bicuspid native pulmonary valve structures.
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Hypertrophic cardiomyopathy is the second most common cardiomyopathy affecting children and adolescents and is the main cause of sudden death of young athletes. The natural prognosis of children with severe hypertrophic obstructive cardiomyopathy is not optimistic, and it is not uncommon for children with hypertrophic obstructive cardiomyopathy who do not respond to medication. Surgical treatment is often the only solution. Conventional surgical methods in the past include classic or modified extended Morrow operation, classic or modified Konno operation, and Ross-Konno operation. In recent years, with the development of minimally invasive surgery, various minimally invasive surgical methods have emerged endlessly. Because the incision of minimally invasive cardiac surgery is significantly smaller than that of traditional surgery, it causes less trauma, recovers quickly after surgery, and has the advantage of no difference in surgical effect compared with traditional median sternotomy. Tally endoscopic transmitral myectomy, RTM, minimally right thoracotomy, and other surgical methods have achieved encouraging results in adults and some older children with hypertrophic obstructive cardiomyopathy. The appearance of transapical beating-heart septectomy has brought the treatment of hypertrophic obstructive cardiomyopathy from the era of cardiopulmonary bypass and cardiac arrest to a new era of minimally invasive beating-heart surgery. In the past, there were few articles about the treatment of children with hypertrophic obstructive cardiomyopathy. This article reviewed the new progress and prognosis of surgical treatment of children with hypertrophic obstructive cardiomyopathy at home and abroad.
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To investigate the influencing factors of postoperative creatine kinase-MB (CK-MB) elevation in children with congenital heart disease and its peak value in predicting early postoperative mortality. The clinical data of 521 children with congenital heart disease under the age of 14 who underwent elective surgery in Beijing Children's Hospital from December 2018 to December 2020 were retrospectively analyzed. Stepwise multiple linear regression was used to analyze independent risk factors for postoperative CK-MB elevation, receiver operating characteristic (ROC) curve was used to determine the predictive value of postoperative CK-MB peak, CK peak, and LDH peak on mortality, and linear correlation and regression analysis were used to analyze the interdependence among postoperative CK-MB peak, CK peak, and LDH peak, and multivariate Logistic regression was used to identify independent risk factors for early postoperative mortality. Preterm birth (P = 0.004), ventriculotomy (P = 0.009), the re-establish of bypass (P = 0.007), cardiopulmonary bypass time (P = 0.024), deep hypothermic circulatory arrest time (P = 0.000), assisted ventilation time (P = 0.049), CK peak (P = 0.000), and LDH peak (P = 0.000) were independently associated with increased postoperative CK-MB elevation. The ROC curve showed that CK-MB peak had the strongest predictive value for death (AUC = 0.924), followed by LDH peak (AUC = 0.864) and CK peak (AUC = 0.758). The cut-off value of the postoperative CK-MB peak was 144.5 IU/L, with a sensitivity of 87% and a specificity of 97%. CK-MB peak was moderately correlated with CK peak (Pearson Correlation coefficient r = 0.514, P = 0.000) and strongly correlated with LDH peak (Pearson Correlation coefficient r = 0.601, P = 0.000). Multivariate analysis showed that delayed chest closure (OR = 4.865, P = 0.004) and postoperative CK-MB peak (OR = 1.031, P = 0.000) were independent risk factors for postoperative mortality. The postoperative CK-MB peak has a certain predictive value for the early postoperative mortality of children with congenital heart disease. It is affected by many factors, and the risk of mortality is significantly increased in children with severely elevated postoperative CK-MB.
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Mercury (Hg), especially methylmercury (MeHg), which is highly neurotoxic, is a global pollutant that can affect human health because of its accumulation in aquatic products. Poyang Lake, an inland lake in China, has been significantly affected by human activity, yet there is limited understanding of local mercury contamination and potential exposure pathways to humans. In this study, we explored the risks of mercury exposure by sampling sediments, plants, and aquatic organisms in the lake and surrounding areas and analyzing total Hg (THg) and MeHg levels. Sediment sampling was conducted at the main lake, rivers, rice paddies, and fishponds. Two dominant species of plants and 15 species of aquatic organisms were sampled and analyzed. We assessed the characteristics of mercury in sediments using the geo-accumulation index (Igeo), mercury exposure using the biomagnification factor (BMF) and biota sediment accumulation factor (BSAF), and risks using thresholds for adverse effects. The highest THg concentrations (137.04 ± 44.3 ng g-1 dw) were detected in the main lake sediments, whereas the highest MeHg concentrations (0.47 ± 0.6 ng g-1 dw) were detected in fishpond sediments. Mercury accumulation in the main lake sediments could be assessed as contaminated (Igeo > 0: 81.6%). Yellow catfish had the highest mercury concentration (THg 770.69 ± 199.7 ng g-1 dw; MeHg 741.93 ± 168.8 ng g-1 dw). Piscivores were adversely affected by carnivorous fish (50.8%), but all fish concentrations did not exceed the food safety standards recommend by China and the WHO. The mercury exposure results revealed significant Hg biomagnification and enrichment (BMF >1: 94.55%; BSAFmax = 1218). Long-term monitoring of aquatic organisms is warranted.
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Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Humanos , Lagos , China , Bioacumulação , Monitoramento Ambiental , Sedimentos Geológicos , PeixesRESUMO
Chemical short-range order (CSRO) refers to atoms of specific elements self-organising within a disordered crystalline matrix to form particular atomic neighbourhoods. CSRO is typically characterized indirectly, using volume-averaged or through projection microscopy techniques that fail to capture the three-dimensional atomistic architectures. Here, we present a machine-learning enhanced approach to break the inherent resolution limits of atom probe tomography enabling three-dimensional imaging of multiple CSROs. We showcase our approach by addressing a long-standing question encountered in body-centred-cubic Fe-Al alloys that see anomalous property changes upon heat treatment. We use it to evidence non-statistical B2-CSRO instead of the generally-expected D03-CSRO. We introduce quantitative correlations among annealing temperature, CSRO, and nano-hardness and electrical resistivity. Our approach is further validated on modified D03-CSRO detected in Fe-Ga. The proposed strategy can be generally employed to investigate short/medium/long-range ordering phenomena in different materials and help design future high-performance materials.
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Forests are important sinks of atmospheric mercury. Quantifying mercury pools in forest ecosystem tissues are essential for understanding the global mercury cycle. To reveal the characteristics of Hg concentration and Hg pool distribution in natural forests at different ages, samples from the vegetation layer, organic horizons, coarse wood debris, and mineral soil layers were collected in young forest, middle forest, near-mature forest, and mature forest of Larix gmelinii forests at the Daxing'an Mountain. The results showed that there were differences in the absorption and accumulation of Hg by different tree species and tissues. In Larix gmelinii, the concentration of Hg followed the order of bark > branch > leaf > root > core, whereas in Betula platyphylla, the order was bark > leaf > branch > root > core. The mercury concentration in the organic horizons increased gradually with the decomposition process. There were no obvious regular patterns in the mercury concentrations of each tissue in different age groups Larix gmelinii forests. Furthermore, total biomass mercury pools (overstory, shrub layer, herb layer, moss layer, and coarse woody debris ï¼CWDï¼) in the young, middle, near-mature, and mature forests of Larix gmelinii forests at Daxing'an Mountain were estimated to be 99.0 µg m-2ï¼207 µg m-2ï¼207 µg m-2 and 194 µg m-2, respectively. On ecosystem scale, total mercury pools were 16.9 mg m-2 (young), 27.5 mg m-2 (middle), 17.0 mg m-2 (near-mature), and 11.8 mg m-2(mature). The mineral soil mercury pool accounts for 94.0%-98.1% of the total ecosystem mercury pool, and its mercury pool proportion gradually decreased with the increase in forest age. These obtained results are quite valuable for further assessing the role of forest ecosystems in the atmospheric mercury cycle and estimating potential mercury emissions from biomass burning during forest wildfires.
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Larix , Mercúrio , Ecossistema , Florestas , Árvores , Solo , Minerais , ChinaRESUMO
OBJECTIVE: To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish, and its underlying mechanisms. METHODS: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide (MTT) assays were performed to investigate the toxicity of ethyl lithospermate at different concentrations (12.5-100 µ mol/L) in RAW 264.7 cells. The cells were stimulated with LPS (100 ng/mL) for 12 h to establish an inflammation model in vitro, the production of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor α (TNF-α) were assessed by enzyme linked immunosorbent assay (ELISA). Western blot was used to ascertain the protein expressions of signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NF-κB) p65, phospho-STAT3 (p-STAT3, Tyr705), inhibitor of NF-κB (IκB) α, and phospho-I κB α (p-IκB α, Ser32), and confocal imaging was used to identify the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705). Additionally, the yolk sacs of zebrafish (3 days post fertilization) were injected with 2 nL LPS (0.5 mg/mL) to induce an inflammation model in vivo. Survival analysis, hematoxylin-eosin (HE) staining, observation of neutrophil migration, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to further study the anti-inflammatory effects of ethyl lithospermate and its probable mechanisms in vivo. RESULTS: The non-toxic concentrations of ethyl lithospermate have been found to range from 12.5 to 100 µ mol/L. Ethyl lithospermate inhibited the release of IL-6 and TNF-α(P<0.05 or P<0.01), decreased IκBα degradation and phosphorylation (P<0.05) as well as the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705) in LPS-induced RAW 264.7 cells (P<0.01). Ethyl lithospermate also decreased inflammatory cells infiltration and neutrophil migration while increasing the survival rate of LPS-stimulated zebrafish (P<0.05 or P<0.01). In addition, ethyl lithospermate also inhibited the mRNA expression levels of of IL-6, TNF-α, IκBα, STAT3, and NF-κB in LPS-stimulated zebrafish (P<0.01). CONCLUSION: Ethyl lithospermate exerts anti-Inflammatory effected by inhibiting the NF-κB and STAT3 signal pathways in RAW 264.7 macrophages and zebrafish.
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Lipopolissacarídeos , NF-kappa B , Animais , Camundongos , NF-kappa B/metabolismo , Células RAW 264.7 , Peixe-Zebra , Inibidor de NF-kappaB alfa/metabolismo , Interleucina-6/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Transcrição STAT3/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêuticoRESUMO
Mercury (Hg) emissions from open biomass burning represent one of the largest Hg inputs to the atmosphere, with considerable effects on the atmospheric Hg budget. However, there is currently large uncertainty in the inventory of Hg emissions from open biomass burning in China due to limitations on the coarse resolution of burned area products, rough biomass data, and the unavailability of suitable emission factors (EFs). In this study, we developed high tempo-spatial resolution (30 m) and long time-series (2000-2019) atmospheric Hg emission inventories from open biomass burning using the Global Annual Burned Area Map (GABAM) product, high-resolution biomass map, Landsat-based tree cover datasets as well as local EFs in China. The results showed that the average annual Hg emission from open biomass burning in China amounted to 172.6 kg during 2000-2019, with a range of 63-398.5 kg. The largest Hg emissions were found in cropland (72%), followed by forest (25.9%), and grassland (2.1%). On a regional level, Northeast China (NE) and Southwest China (SW) were the two main contributors, together accounting for more than 60% of total Hg emissions. The temporal distribution of Hg emissions showed that the peaks occurred in 2003 and 2014. This is a comprehensive estimation of Hg emissions from open biomass burning in China by integrating various high-resolution remotely sensed data and nationwide localized EFs, which has important implications for understanding the role of open biomass burning in China in regional and global atmospheric Hg budget.
Assuntos
Poluentes Atmosféricos , Mercúrio , Mercúrio/análise , Biomassa , Poluentes Atmosféricos/análise , Tecnologia de Sensoriamento Remoto , China , Monitoramento AmbientalRESUMO
PURPOSE: Bladder cancer (BCa) is one of the most common cancer types worldwide and is characterized by a high rate of recurrence. In previous studies, we and others have described the functional influence of plasminogen activator inhibitor-1 (PAI1) in bladder cancer development. While polymorphisms in PAI1 have been associated with increased risk and worsened prognosis in some cancers, the mutational status of PAI1 in human bladder tumors has not been well defined. METHODS: In this study, we evaluated the mutational status of PAI1 in a series of independent cohorts, comprised of a total of 660 subjects. RESULTS: Sequencing analyses identified two clinically relevant 3' untranslated region (UTR) single nucleotide polymorphisms (SNPs) in PAI1 (rs7242; rs1050813). Somatic SNP rs7242 was present in human BCa cohorts (overall incidence of 72%; 62% in Caucasians and 72% in Asians). In contrast, the overall incidence of germline SNP rs1050813 was 18% (39% in Caucasians and 6% in Asians). Furthermore, Caucasian patients with at least one of the described SNPs had worse recurrence-free survival and overall survival (p = 0.03 and p = 0.03, respectively). In vitro functional studies demonstrated that SNP rs7242 increased the anti-apoptotic effect of PAI1, and SNP rs1050813 was related to a loss of contact inhibition associated with cellular proliferation when compared to wild type. CONCLUSION: Further investigation of the prevalence and potential downstream influence of these SNPs in bladder cancer is warranted.