Simple Defects Research Articles

Clinical Presentation and Therapy of Semilunar Valve and Aortic Arch Anomalies.

The following semilunar valve defects and aortic arch anomalies are called simple defects because there is a single problem that can be well described. Based on the degree of malformation and hemodynamic consequence, these simple lesions can however be life threatening immediately after birth. They all affect either the left or right outflow tract or the aortic arch.

High-Precision Corrosion Detection via SH1 Guided Wave Based on Full Waveform Inversion.

Corrosion detection for industrial settings is crucial for safe and efficient operations. Due to its high imaging resolution, the guided-wave full-waveform inversion tomography technique has significant potential for corrosion detection of plate metals. Limited by the long wavelengths of A0 and S0 mode waves, this method exhibits inadequate detection resolution for the earlier shallow and small corrosion defects. Based on the relatively short wavelength characteristics of the SH1 mode wave, we propose a high-precision corrosion detection method via SH1 guided wave using the full waveform inversion algorithms. By conducting finite element simulations of ultrasonic-guided waves on aluminum plates with varying corrosion defects, a comparison was made to assess the detection precision across A0, S0, and SH1 modes. The comparison results showed that, whether for regular or irregular defects, the SH1 mode wave always exhibited higher imaging accuracy than the A0 and S0 mode waves for shallow and small-sized defects. The corresponding experiments were conducted on an aluminum plate with simple or complex defects. The results of the experiments reconfirmed that the full waveform inversion method using SH1 guided wave can effectively reconstruct the shape and size of small and shallow corrosion defects within aluminum plates.

Hydrogen-Bonded Organic Framework Derived 2D N, O Co-Doped Carbon Nanobelt with Tunable Pseudocapacitive Contribution for Efficient Capacitive Deionization.

Defect engineering is recognized as an attractive method for modulating the electronic structure and physicochemical characteristics of carbon materials. Exploiting heteroatom-doped porous carbon with copious active sites has attracted great attention for capacitive deionization (CDI). However, traditional methods often rely on the utilization of additional heteroatom sources and strong corrosive activators, suffering from low doping efficiency, insufficient doping level, and potential biotoxicity. Herein, hydrogen-bonded organic frameworks (HOFs) are employed as precursors to synthesize N, O co-doped porous carbon via a simple and green reverse defect engineering strategy, achieving controllable heavy doping of heteroatoms. The N, O co-doping triggers significant pseudocapacitive contribution and the surface pore structure supports the formation of the electric double layer. Therefore, when HOF-derived N, O co-doped carbon is used as CDI electrodes, a superior salt adsorption capacity of 32.29±1.42mgg-1 and an outstanding maximum salt adsorption rate of 10.58±0.46mgg-1min-1 at 1.6V in 500mgL-1 NaCl solution are achieved, which are comparable to those of state-of-the-art carbonaceous electrodes. This work exemplifies the effectiveness of the reverse nitrogen-heavy doping strategy on improving the carbon structure, shedding light on the further development of rational designed electrode materials for CDI.

Thermal conductivity suppression in uranium-doped thorium dioxide due to phonon-spin interactions

In this work, impact of low level of uranium (U) atom substitution on thermal conductivity of thorium dioxide (ThO2) is investigated. ThO2 is an electronic insulator with a wide optical band-gap and no unpaired electrons whose thermal transport is governed by phonons. U-substitution introduces unpaired f-electrons resulting in paramagnetic behavior of UThO2 at room temperature, which significantly suppresses its thermal conductivity. A single crystal of UThO2 with graded composition of U is grown using a hydrothermal synthesis method, and thermal conductivity measurements are performed in regions with uniform composition of U at levels of 0%, 6%, 9% and 16%. Measured thermal conductivity profiles over 77–300 K temperature range are analyzed using an analytical expression for phonon-mediated thermal transport based on Klemens-Callaway model. Temperature dependent thermal conductivity is found to deviate significantly from the Rayleigh scattering trend expected for a simple substitutional point defect with a small perturbation to mass and interatomic forces. With the resonant scattering term, observed large suppression of thermal conductivity at low temperatures can be closely reproduced. Additionally, the extracted phonon-spin coupling constants imply a nonlinear relation of phonon-spin interaction intensity with respect to U doping percentage. Our study reveals how phonon-spin scattering contributed by unpaired f-electrons in U atoms influences thermal transport in the UThO2 system.

Research on ultrasonic defect imaging based on a neural network with Gaussian weight function fusion model

Ultrasonic testing is widely used in the industrial field because of its high sensitivity, safety and low-cost, which plays an increasingly important role in detecting defects on industrial. However, at present, defect detection only stays in scanning surface defects and classifying the internal defects of the specimen. The accuracy of quantitative imaging of the morphology of the internal defects of the specimen is still an issue to be improved. In this paper, the simple defects in several specimens are detected by ultrasound based on finite element simulation software and the accuracy of the signal can be verified by ultrasonic experiment. Then, the features can be extracted by signal processing method. The neural network imagines the inversion results with the Gaussian weight function fusion model. Finally, this paper uses the signals of simple shape defects as the training set to detect the shapes of complex defects and obtain the corresponding imaging results.

Atrial septal defect patients have an elevated risk for infective endocarditis

Abstract Background It has been unclear whether simple atrial septal defect (ASD) is an independent risk factor for infective endocarditis (IE). This study aimed to untangle the risk of endocarditis in a large nationwide cohort. Methods We acquired data from the Finnish hospital discharge register on all individuals with ASD diagnosis from 1969 to 2019. Patients with complex congenital cardiac abnormalities were ruled out. Five individualized controls from the general population were matched to the ASD patient's birth year, sex, and residence at the index date. All the patients with ICD-8, -9, or -10 diagnosis codes for IE were gathered from the hospital discharge registry. Results After exclusion, 8322 ASD patients and 39 237 individualized controls were enrolled in the study. Median follow-up was 21.6 years (IQR 11.8-36.9) from the first hospital contact. In total, 24 (16 male) cases of infective endocarditis among ASD patients and 10 (8 male) cases among controls were diagnosed during the follow-up. The incidence of endocarditis was 0.11 per 1000 person-years in the ASD patients and 0.011 per 1000 person-years in the controls. The adjusted risk ratio for endocarditis was 13.51 (95% CI: 6.20–29.46) in ASD patients compared to the control cohort. Patients with ASD and endocarditis had higher long-term mortality than individualized control patients (MRR 2.25, 95% CI: 1.23-4.11). Conclusions The incidence of endocarditis in atrial septal defect patients is higher than in the general population, and ASD seems to carry an increased risk of developing endocarditis.Cumulative incidence of endocarditisSurvival after endocarditis diagnosis

Minimally Invasive Surgery for Simple Congenital Heart Defects: Preserving Aesthetics without Jeopardizing Patient Safety.

Minimally invasive surgeries for pediatric patients have been proposed for decades, with different approaches in mind. Minimal right axillary thoracotomy (MRAT), proposed two decades ago, allows the preservation of patients' safety alongside faster aesthetic and functional recovery. The MRAT did not become widely adopted due to the prejudice that to follow a minimally invasive approach, safety and efficacy must be compromised. With this study, we aim to compare MRAT to the standard median sternotomy approach with a focus on safety and clinical outcomes. Between January 2017 and April 2021, 216 patients diagnosed with ASD, pAVSD, or PAPVD underwent surgical repair with different approaches in the same period. MRAT was used for 78 patients, and median sternotomy was used for 138 patients. In this last group, standard median sternotomy (SMS) was used for 116 patients, while a minimal skin incision (SMS mini) was used for 22 patients. There were no major complications overall nor in each specific approach. MRAT enabled the successful repair of simple heart defects, providing similar post-operative and cardiological recovery. MRAT does not compromise patients' safety and does not prolong the duration of surgery once the learning curve is overcome, which is generally after 15-20 consecutive operations.

A systematic tomography framework for thickness mapping of pipes using helical guided waves

Pipe wall loss caused by corrosion is of growing interest in the petrochemical industry. A systematic tomography framework using helical guided waves is developed in this paper to conduct a thickness mapping. In this work, the thickness under investigation is reconstructed using an objective function derived from the acoustic Helmholtz equation. The main approach consists of two parts. Firstly, the parametric dictionary is designed to separate the overlapped guided waves travelling in helical paths. After that, the scattering field can be extracted as the input of the distorted born iteration method. The imaging result is exemplified numerically and experimentally, with the strengths and drawbacks explained thoroughly. Remarkably, the thickness error of the simple defect is still within 0.5 mm when the input data is poor. A clear qualitative description of complex defects can be achieved through iterations even in the absence of an initial objective function. The framework established in this paper contributes a comprehensive imaging algorithm and the corresponding signal processing approach, all of which are conducive to providing some reference for engineering applications in nondestructive testing and structural health monitoring.

Study on burst pressure of subsea pipelines with asymmetrical corrosion defects

As an efficient and inexpensive tool, pipelines are widely used in the transportation of hydrogen, carbon dioxide, oil and gas. The subsea pipelines are inevitably corroded because of the transportation environment and medium. The scholars have studied burst pressure of pipelines with simple corrosion defects, However, there are many research gaps in the burst pressure analysis of pipelines with complex corrosion defects. In this paper, the burst pressure of subsea pipelines with asymmetrical corrosion defects is studied. Firstly, a model of pipelines with asymmetrical and external corrosion defects is established. Then, the finite element method is conducted to analyze the burst capability of subsea pipelines with asymmetrical corrosion defects. Next, a novel method of simplifying asymmetrical corrosion defects is proposed. In the end, a modified DNV equation is presented to predict the burst pressure of subsea pipelines with asymmetrical corrosion defects. This study can provide a novel idea for obtaining the burst pressure of subsea pipelines with complex corrosion defects.

Self- and proxy-reported impaired social interaction in young adults with simple congenital heart defects.

Simple Congenital Heart Defects such as septal defects constitute a large proportion of Congenital Heart Defects. New research has demonstrated more co-morbidities than previously thought. In particular, co-morbidities involving neurocognitive, psychiatric, and social difficulties have been described. Neurocognitive and psychiatric morbidities affect social interaction. Social interaction is important in everyday social life (education, work life, family life). In this study, we investigated social interaction through self- and proxy-answered Social Responsiveness Scale 2 (SRS-2) in young adults with simple Congenital Heart Defects and compared their social interaction profile to healthy matched controls. We included a total of 80 patients with either atrial or ventricular septal defect (age 26.6 years) and 38 heart-healthy, age, sex, and ISCED educational matched controls (age: 25.3 years). A close relative proxy from each participant took part in the study as well. All participants answered the Social Responsiveness Scale 2 (SRS-2) (n = 225). Our primary and secondary outcomes were the SRS-2 Total score and the SRS-2 sub-scores. In the Congenital Heart Defects group, 31.3% had a Total score above 60 compared to 7.9% in the control group (p = 0.005, RR = 3.96). The participants with a septal defect had a higher Total score (52.5 vs. 45.5, p = 0.004), a higher Social Cognition sub-score (55.0 vs. 47.0, p = 0.0004), and a higher Social Motivation sub-score (50.0 vs. 45.0, p = 0.003) than the heart-healthy participants. We found no difference between the two groups regarding the sub-scores of Social Awareness and Social Communication. A multiple linear regression model showed that the variable that explained most of the variation in Total Score was having a previously diagnosed psychiatric disorder. We found that young adults with atrial or ventricular septal defects have a fourfold increased risk of social interaction difficulties compared to heart-healthy peers. They have a social interaction profile, with difficulties in social cognition and social motivation, and preserved social awareness and social communication. Psychiatric morbidity explained most of the variation in social interaction problems. As social difficulties and psychiatric morbidities are intertwined, social interaction difficulties could be an indication of already underlying psychiatric morbidities or a risk factor for future psychiatric morbidity.

Profile of cardiac lesions among laboratory confirmed congenital rubella syndrome (CRS) infants: a nationwide sentinel surveillance, India, 2016-22.

The phenotypical profile of cardiovascular malformations in patients with congenital rubella syndrome (CRS) is varied. We aimed to describe the profile of cardiac defects among CRS patients detected in the sentinel CRS surveillance in India during 2016-22. Sentinel sites enrolled infants with suspected CRS based on presence of cardiac defects, hearing impairment, eye signs, or maternal history of febrile rash illness. Suspected CRS cases underwent detailed systemic examination, including echocardiography and serological investigation for rubella. Cardiac defects were categorized as 'Simple' or 'Complex' as per the National Heart, Lung, and Blood Institute classification. We compared the distribution of cardiac defects among laboratory confirmed CRS cases and seronegative discarded cases. Of the 4578 suspected CRS cases enrolled by 14 sites, 558 (12.2%) were laboratory confirmed. 419 (75.1%) laboratory confirmed cases had structural heart defects (simple defects: n=273, 65.2%, complex defects: n=144, 34.4%), with ventricular septal defect (42.7%), atrial septal defect (39.4%), patent ductus arteriosus (36.5%), and tetralogy of Fallot as the commonest defects (4.5%). Laboratory confirmed CRS cases had higher odds of left to right shunt lesions (OR=1.58, 95% CI: 1.15-2.17). This was mainly on account of a significant association of PDA with CRS (OR=1.77, 95% CI: 1.42-2.21). Mortality was higher among CRS patients with complex heart defects (HR=2.04, 95% CI: 1.26-3.30). Three-fourths of the laboratory confirmed CRS cases had structural heart defects. CRS patients with complex cardiac defects had higher mortality. Detecting CRS infection early and providing timely intervention for cardiovascular defects is critical for the management of CRS patients. Ministry of Health and Family Welfare, Govt of India, through Gavi, the Vaccine Alliance.

Effective and aesthetic results of horizontal right axillary minithoracotomy for congenital heart defects repair in children

Background: horizontal right axillary minithoracotomy is one of the treatment options for many simple congenital heart defects. This approach shows many aesthetic advantages besides effectiveness and safety. This study aims to: comment on the technical characteristics and early results of horizontal right axillary minithoracotomy in children at Hanoi Heart Hospital.
 Methods: a descriptive cross-sectional study. We retrospectively reviewed 156 patients who underwent horizontal right axillary minithoracotomy at Hanoi Heart Hospital from January 2022 to December 2022.
 Results: horizontal axillary approach could be applied even for children with low weight, average weight was 12.22 ± 8.67 kg, the lowest was 2.6 kg and the highest was 51.0 kg. A wide range of congenital heart defects were repaired, including ventricular septal defect closure (84 patients), secundum atrial septal defect closure (22 patients), ventricular septal defect with stenosis repair (31 patients), partial atrio-ventricular septal canal repair (6 patients), repair of atrial septal defect with partial abnormal return of the pulmonary veins (3 patients), repair of ventricular septal defect and atrial septal defect (4 patients), Cor triatriatum sinister repair (4 patients), mitral valve repair (1 patient), atrial septal defect and pulmonary valve stenosis repair (1 patient). Cannulation of the aorta and vena cavae was performed through the main incision, whose size ranged from 3.5 to 5.5cm. The average postoperative hospital stay was 7.34 ± 2.16 days, the rate of severe complications and hospital mortality were 0%.
 Conclusion: horizontal right axillary minithoracotomy was a good approach to correct many simple congenital heart defects in children. This technique is being applied at Hanoi Heart Hospital safely and provided outstanding advantages in terms of aesthetics.

Residual pulmonary hypertension after left to right shunt closure in common pediatric congenital heart diseases: rate and risk factors

Introduction: Left to right shunt in congenital heart disease is the common causes of pulmonary hypertension (PH) in children, and the pulmonary pressure sometime isn’t recovered to normal value after the shunts closed. Residual PH after correcting these shunts may cause deaths. The purpose of this study was to describe the rate of residual PH after surgical closure the left to right shunts in pediatric congenital heart disease and determine its risk factors.
 Patients and methods: A retrospective study was performed on the medical recorded documents of 59 children who were diagnosed pulmonary artery hypertension associated with common left to right shunt congenital heart diseases and performed shunt closure surgically at Cho Ray hospital between January 2020 and May 2022. Systolic pulmonary artery pressure (PAPs) was measured via tricuspid regurgitation jet on transthoracic echocardiography (mode: continuous wave doppler, plane: apical 4-chamber). PH was defined as PAPs ≥ 40mmHg. Postoperative PAPs was measured 1 day before discharge.
 Results: The median age and weight at surgery were 7 months (2 – 215) and 5.9 kg (3.6 – 35), 59.3% was female. Preoperatively, 66.1% were mild PH, 33.9% moderate. Postoperatively, 10 patients (17%) diagnosed residual PH and all was mild. Among 10 patients with residual PH: 7 were combined defects (5 VSD-PDA, 2 VSD-ASD), 3 simple defects (2 VSD, 1 ASD). Preoperative high pulmonary pressure was associated with residual PH (correlation coefficient 0.116, p = 0.001). Conclusions: The proportion of patients with postoperatiovely residual PH is significant and most of these cases are combined shunt. Preoperative high pulmonary pressure is related to residual PH.

Penile Length Assessment of Children Treated for Primary Buried Penis: Can Satisfying Penile Growth Always Be Achieved?

Primary buried (BP) penis is describes as a small penis caused by a penile ligaments anomaly; it is unclear if a primary BP could reach a normal length. We selected 49 patients treated at our institution between 2015 and 2020 in order to post-operatively evaluate the SPL after one year. SPL was evaluated according to the PH Tanner staging system for pre-pubertal patients according to age-normalized values. A micropenis was detected if the SPL was below 2.5 SD. A normal SPL was found in thirty-two patients, eighteen were in PH Stage 1, four were in PH Stage 2, six were in PH Stage 3, and four were in PH Stage 5. Seventeen patients showed a reduced SPL; in seven of these (four in PH Stage 4 and three in PH Stage 5), their SPL was <2.5 ST. The difference in micropenis prevalence between the pre-pubertal and post-pubertal patients was significant (p = 0.038). A primary BP grows normally during the pre-pubertal period, where patients frequently showed a normal SPL, but it seems to be unable to reach a normal length in the higher PH stages, where the SPL is used to detect a micropenis. We suggest that a primary BP should be considered not as a simple defect of the penile ligaments and surrounding tissues, but as an incomplete manifestation of a micropenis due to a growth slowdown of the organ in late puberty.

Effect of different defects on the polarization mechanism of (Nb,Ga) codoped TiO2 single crystals

Various defects have a profound impact on the dielectric properties and polarization mechanisms of (Nb,Ga) codoped TiO2 crystals. However, the research conducted in this area remains limited. To address this, we grew (Nb,Ga) codoped TiO2 crystals via the Verneuil method and investigated their dielectric properties under various atmospheric annealing conditions. Annealing in oxygen reduces the number of defects. In this case, the point defects associated with oxygen vacancies is unable to fully form the ideal complex defect clusters which can form effective pegging of free electrons. On the other hand, the defects are mainly in the form of simple defect clusters that causes hopping polarization. Annealing under mixed gas (Ar:H2 = 95%:5%) increases the number of defects and contains more free carriers, which migrate to the interface between the sample and the electrode, leading to interfacial polarization. Both hopping polarization and interfacial polarization are slow polarization, resulting in an increase in dielectric loss and a decrease in frequency stability. Annealing in air or nitrogen atmospheres forms ideal defect dipole clusters, where the electron-pinned defect dipoles (EPDD) are predominantly polarized, resulting in superior dielectric properties. It has been clarified that EPDD as the main polarization form can yield better dielectric properties. By focusing on single crystals as the research subject, we effectively eliminate the influence of grain boundaries, enabling a more accurate assessment of the effects of various crystal defects on dielectric properties. This study holds substantial implications for the advancement of TiO2-based dielectric materials, offering valuable insights into their performance optimization.

A novel defect reassembly strategy for NH2-MIL-125(Ti) to enhance the photocatalytic NO removal activity

Photocatalysis technology has been widely used to eliminate typical air pollutants, but its further application is limited by the finite visible light response and severe charge carrier recombination. In this study, through a simple defect reassembly strategy, the carboxyl group of highly photosensitive eosin Y is successfully coordinated with the exposed Ti clusters in the defective NH2-MIL-125(Ti) to improve photocatalytic activity. The results demonstrate that the NO removal rate of the optimal sample (named D-NM-125/EY) is about 62.05%, which is 1.62 times that of the original NH2-MIL-125(Ti). The UV–Vis, PL, and photochemical characterization analysis confirm that the incorporation of eosin Y significantly can enhance the visible light absorption capacity and promote the photogenerated carriers separation, which may be due to that eosin Y can more easily absorb and utilize visible light to produce more photogenerated electron-hole pairs. Combining ESR with in-situ DRIFTS analysis, the possible photocatalytic mechanism is revealed, in which the reactive oxygen species generated in the photocatalytic process are the key factors for the successful degradation of NO into less toxic substances. This study will provide a new strategy for modifying MOFs photocatalysts to solve typical air pollution problems.

Colorado Needle Assisted Cross-Leg Flap

Lower limb injuries are most commonly due to road traffic accidents which cause lower limb defects.The management of lower limb fractures is guided by the Gustilo-Anderson classification of injuries. Simple leg defects are covered by localflap and complex defects by free flap. Complex defects of the lower limbs which were unfit for free flap require management by conventional cross leg flap. Colorado needle allows meticulous dissection of flaps due to the sharp tip and increases the efficiency in raising the flaps.

Atrial septal defect patients have an elevated risk for infective endocarditis

Background. It has been unclear whether simple atrial septal defect (ASD) is an independent risk factor for infective endocarditis (IE). This study aimed to untangle the risk of endocarditis in a large nationwide cohort. Methods. We acquired data from the Finnish hospital discharge register on all individuals with ASD diagnosis from 1969 to 2019. Patients with complex congenital cardiac abnormalities were ruled out. Five individualized controls from the general population were matched to the ASD patient’s birth year, sex, and residence at the index date. All the patients with ICD-8, −9, or −10 diagnosis codes for IE were gathered from the hospital discharge registry. Results. Altogether, 8322 patients with ASD and 39,237 individualized controls were enrolled in the study. Median follow-up was 21.6 years (IQR 11.8–36.9) from the first hospital contact. In total, 24 (16 male) cases of infective endocarditis among ASD patients and 10 (8 male) cases among controls were diagnosed during the follow-up. The incidence of endocarditis was 0.11 per 1000 person-years in the patients with ASD and 0.011 per 1000 person-years in the controls. The adjusted risk ratio for endocarditis was 13.51 (95% CI: 6.20–29.46) in patients with ASD compared to the control cohort. Patients with ASD and endocarditis had higher long-term mortality than individualized control patients (MRR 2.25, 95% CI: 1.23–4.11). Conclusions. The incidence of IE in patients with ASD was higher than in the general population. Mortality associated with IE was higher in patients with ASD compared to controls.

Magnetic Charge Model for Leakage Signals from Surface Defects in Ferromagnetic Material.

A novel three-dimensional theoretical model of magnetic flux leakage (MFL) is proposed in this paper based on the magnetic dipole model. The magnetic dipole model assumes that a ferromagnetic specimen with defects is exposed to a uniform external magnetic field that causes a uniform magnetization around the defect surface. Under this assumption, the MFL can be regarded as arising from magnetic charges on the defect surface. Previous theoretical models were mostly used to analyze simple crack defects such as cylindrical and rectangular cracks. In this paper, we developed a magnetic dipole model for more complex defect shapes such as circular truncated holes, conical holes, elliptical holes, and double-curve-shaped crack holes to complement the existing defect shapes. Experimental results and comparisons with previous models demonstrate that the proposed model provides a better approximation of complex defect shapes.

Safety and effectivity of right vertical infra-axillary thoracotomy for repair of simple congenital cardiac defects

Safety and effectivity of right vertical infra-axillary thoracotomy for repair of simple congenital cardiac defects