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Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices requires integration of ferroelectric and semiconductor materials. The emergence of hafnium oxide (HfO 2 )–based ferroelectrics that are compatible with atomic-layer deposition has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO 2 are still mysterious. We demonstrate that local helium (He) implantation can activate ferroelectricity in these materials. The possible competing mechanisms, including He ion–induced molar volume changes, vacancy redistribution, vacancy generation, and activation of vacancy mobility, are analyzed. These findings both reveal the origins of ferroelectricity in this system and open pathways for nanoengineered binary ferroelectrics.

Background: Retrograde aortic root dissection toward the coronary ostium is uncommon, and acute myocardial ischemia is a potentially fatal condition in this situation. Repairing dissected coronary arteries to prevent myocardial malperfusion is difficult and we introduce our technique with case presentation. Case presentation: A 52-year-old male patient was admitted for acute type A aortic dissection. Circumferential detachment of the right coronary artery (RCA) ostium was detected intraoperatively. The proximal RCA was dissected, the intimal RCA was circumferentially detached with inner intussusception, and only adventitia was partially connected to the aortic root. Instead of performing coronary artery bypass grafting surgery to the RCA, direct RCA implantation to the ascending graft was performed after repairing the dissected lumen of the proximal RCA. Cardiopulmonary bypass weaning was smooth, and no complications related to the RCA were observed. Conclusion: Repairing dissected coronary artery at retrograde aortic root dissection is feasible option.

Background The diagnosis of dental implants and the periapical tissues using periapical radiographs is crucial. Recently, artificial intelligence has shown a rapid advancement in the field of radiographic imaging. Purpose This study attempted to detect dental implants and peri-implant tissues by using a deep learning method known as object detection on the implant image of periapical radiographs. Methods After implant treatment, the periapical images were collected and data were processed by labeling the dental implant and peri-implant tissue together in the images. Next, 300 images of the periapical radiographs were split into 80:20 ratio (i.e. 80% of the data were used for training the model while 20% were used for testing the model). These were evaluated using an object detection model known as Faster R-CNN, which simultaneously performs classification and localization. This model was evaluated on the classification performance using metrics, including precision, recall, and F1 score. Additionally, in order to assess the localization performance, an evaluation through intersection over union (IoU) was utilized, and, Average Precision (AP) was used to assess both the classification and localization performance. Results Considering the classification performance, precision = 0.977, recall = 0.992, and F1 score = 0.984 were derived. The indicator of localization was derived as mean IoU = 0.907. On the other hand, considering the indicators of both classification and localization performance, AP showed an object detection level of AP@0.5 = 0.996 and AP@0.75 = 0.967. Conclusion Thus, the implementation of Faster R-CNN model for object detection on 300 periapical radiographic images including dental implants, resulted in high-quality object detection for dental implants and peri-implant tissues.

Metal nanoparticles (MeNPs) have been used in various industrial applications, owing to their unique physical and chemical properties different from the bulk counterparts. However, the natural oxidation of MeNPs is an imminent hindrance to their widespread applications despite much research efforts to prevent it. Here, a rational approach for non-oxidized bare MeNPs in air, which requires no additional surface passivation treatment is reported. The direct synthetic route uses the [Gd

Background Total anomalous pulmonary venous return (TAPVR) is rare congenital heart disease. Most TAPVRs require surgical corrections in the neonatal period and survival to adulthood without surgical correction is extremely rare. Most untreated patients with large atrial septal defects and no pulmonary venous obstruction have pulmonary vascular damage from pulmonary over circulation. Case presentation 44-year-old TAPVR patient admitted to our medical center. A snowman-shaped heart, including cardiomegaly and an increase in pulmonary blood flow, was seen in the chest X-ray. A large-sized (around 3 cm) atrial septal defect with dilated right atrium, right ventricle, and pulmonary artery was detected on echocardiography. Heart computed tomography was performed for further evaluation, and supra-cardiac type TAPVR without any obstructive lesion was identified. Conclusions TAPVR in an adult patient is extremely rare, and this patient was treated successfully with surgical correction and is doing well. A sinus rhythm and mild mitral valve regurgitation have remained during 2.5 years of outpatient follow-up.

Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices requires integration of ferroelectric and semiconductor materials. The emergence of hafnium oxide (HfO

Two advanced, automated crystal orientation mapping techniques suited for nanocrystalline materials—precession electron diffraction (PED) in transmission electron microscopy (TEM) and on-axis transmission Kikuchi diffraction (TKD) in scanning electron microscopy (SEM)—are evaluated by comparing the orientation maps obtained from the identical location on a 30 nm-thick nanocrystalline tungsten (W) thin film. A side-by-side comparison of the orientation maps directly showed that the large-scale orientation features are almost identical. However, there are differences in the fine details, which arise from the fundamentally different nature of the spot pattern and Kikuchi line pattern in terms of the excitation volume and the angular resolution. While TEM-PED is more reliable to characterize grains oriented along low-index zone axes, the high angular resolution of SEM-TKD allows the detection of small misorientation between grains and thus yields better quantification and statistical analysis of grain orientation. Given that both TEM-PED and SEM-TKD orientation mapping techniques are complementary tools for nanocrystalline materials, one can be favorably selected depending on the requirements of the analysis, as they have competitive performance in terms of angular resolution and texture quantification.

Background: Atrial septal defect (ASD) is the most common congenital heart disease. However, the details of cardiac chamber remodeling after surgery are not well known, although this is an important issue that should be analyzed to understand long-term outcomes. Methods: Between November 2017 and January 2019, cardiac magnetic resonance imaging was performed preoperatively, at a 1-month postoperative follow-up, and at a 1-year postoperative follow-up. Cardiac chamber volume, valve regurgitation volume, and ejection fraction were measured as functions of time. Results: Thirteen patients (10 men and 3 women) were included. The median age at surgery was 51.4 years. The preoperative median ratio of flow in the pulmonary and systemic circulation was 2.3. The preoperative mean right ventricular (RV) end-diastolic volume index (EDVi) and RV end-systolic volume index (ESVi) had significantly decreased at the 1-month postoperative follow-up (p

Engineering active sites of metal nanoparticle-based heterogeneous catalysts is one of the most prerequisite approaches for the efficient production of chemicals, but the limited active sites and undesired oxidation on the metal nanoparticles still remain as key challenges. Here, it is reported that the negatively charged surface of copper nanoparticles on the 2D [Ca

Copper (Cu) nanoparticles (NPs) have received extensive interest owing to their advantageous properties compared with their bulk counterparts. Although the natural oxidation of Cu NPs can be alleviated by passivating the surfaces with additional moieties, obtaining non-oxidized bare Cu NPs in air remains challenging. Here we report that bare Cu NPs with surface excess electrons retain their non-oxidized state over several months in ambient air. Cu NPs grown on an electride support with excellent electron transfer ability are encapsulated by the surface-accumulated excess electrons, exhibiting an ultralow work function of ~3.2 eV. Atomic-scale structural and chemical analyses confirm the absence of Cu oxide moiety at the outermost surface of air-exposed bare Cu NPs. Theoretical energetics clarify that the surface-accumulated excess electrons suppress the oxygen adsorption and consequently prohibit the infiltration of oxygen into the Cu lattice, provoking the endothermic reaction for oxidation process. Our results will further stimulate the practical use of metal NPs in versatile applications.

INTRODUCTION Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) catheter ablation. However, a PVI alone has been considered insufficient for persistent AF. This study aimed to evaluate the efficacy of persistent AF ablation targeting complex fractionated atrial electrogram (CFAE) areas within low voltage zones identified by high-resolution mapping in addition to the PVI. METHODS We randomized 50 patients (mean age 58.4 ± 9.5 years old, 86.0% males) with persistent AF to a PVI + CFAE group and PVI only group in a 1:1 ratio. CFAE and voltage mapping was performed simultaneously using a Pentaray Catheter with the CARTO3 CONFIDENSE module (Biosense Webster, CA, USA). The PVI + CFAE group, in addition to the PVI, underwent ablation targeting low voltage areas (

It is known that only in-plane piezoelectricity exists in pristine two dimensional (2D) transition metal dichalcogenides (TMDs). In this study, we demonstrate the creation of strong out-of-plane piezoelectricity in semiconducting 2H-MoTe2 flakes by an artificial atomic-scale symmetry breaking. The atomic-scale symmetry breaking associated with flexoelectricity was realized through Te vacancy formation by a simple thermal annealing of the 2D TMDs. The strong out-of-plane piezoelectricity was experimentally measured and confirmed by theoretical calculations. This strategy of atomic-scale symmetry modulation for out-of-plane piezoelectricity can be easily applied to a broader class of 2D TMD materials that have not been used for applications with out-of-plane piezoelectricity. Accordingly, it can stimulate the expansion of practical energy device applications with 2D TMD materials.

The increasing interest in portable and consumable electronics demands efficient and low-cost energy storage devices with excellent energy storing capacity. From this point, a high mass loading of the active electrode material on three-dimensional current collectors is favorable for obtaining a higher energy storing capacity for the corresponding device. The present study demonstrates an ideal example of high-performance aqueous asymmetric supercapacitors (SCs) using α-MnO2 nanowires as the positive electrode and h-WO3 nanorods as the negative electrode, respectively. Initially, one-dimensional (1D) nanostructures composed of α-MnO2 and h-WO3 are prepared on carbon cloth by a conventional hydrothermal method. The prepared α-MnO2 and h-WO3 with a high mass loading of 4.9 mg/cm2 and 5.8 mg/cm2, respectively, show excellent electrochemical features in aqueous Na2SO4 electrolyte in the positive and negative potential regions. A high-performance asymmetric SC is developed with uniquely engineered electrodes, which exhibits the excellent electrochemical performance in an extended potential window of 1.4 V and with excellent cycling stability of ∼135% after 7500 cycles with a volumetric capacitance of 350 mF/cm3 and energy density of 0.095 mWh/cm3. This authentic scheme may offer new opportunities for developing asymmetric arrangements for energy storage devices in various portable electronic systems with a high mass loading.

BACKGROUND: An enlarged left atrium (LA) is a well-known risk factor for ablation failure of atrial fibrillation (AF). We analyzed the result of concomitant AF ablation in patients with a giant LA and evaluated the effect of LA volume reduction. METHODS: Between 2000 and 2011, 116 patients with a giant LA (antero-posterior dimension ≥70 mm) who underwent surgical AF ablation during MV surgery were retrospectively reviewed. Among these, 28 patients received aggressive LA volume reduction procedure (reduction group) while the other 88 patients received the surgery without LA volume reduction (non-reduction group). Mean follow-up duration was 6.8±3.0 years. RESULTS: Aortic clamping and cardio-pulmonary bypass times were significantly longer in reduction group than non-reduction group (P0.99) and major complication rates. Rates of freedom from AF at 1, 3 and 5 years were 84.2%, 74.3% and 54.5%, respectively in reduction group and 49.0%, 33.2% and 28.4%, respectively in non-reduction group (P=0.013). Multivariable analysis revealed severe pulmonary hypertension as an independent risk factor for AF recurrence (HR, 15.9; 95% CI, 1.69–149.54, P=0.015) while LA volume reduction (HR, 0.50; 95% CI, 0.28–0.89, P=0.018) and the use of cryoablation instead of radiofrequency (HR, 0.11; 95% CI, 0.01–0.95, P=0.045) were found to be protective against AF recurrence. CONCLUSIONS: Aggressive LA volume reduction was found to improve rhythm outcomes in patients with a giant LA undergoing surgical AF ablation.

Plasma-enhanced atomic layer deposition (PEALD) is well-known for fabricating conformal and uniform films with a well-controlled thickness at the atomic level over any type of supporting substrate. We prepared nickel oxide (NiO) thin films via PEALD using bis(ethylcyclopentadienyl)-nickel (Ni(EtCp)2) and O2 plasma. To optimize the PEALD process, the effects of parameters such as the precursor pulsing time, purging time, O2 plasma exposure time, and power were examined. The optimal PEALD process has a wide deposition-temperature range of 100–325 °C and a growth rate of 0.037±0.002 nm per cycle. The NiO films deposited on a silicon substrate with a high aspect ratio exhibited excellent conformality and high linearity with respect to the number of PEALD cycles, without nucleation delay.

Recently, smart farm technology is in the spotlight as the solution of existing agricultural problems as spreading ICT convergence technology. For assisting expert farmers or guiding non-farmers, there is a need for a predicting method of growing and benefiting of crops as well as cultivating them through the cultivating method on AI/Big data approach. To do this, we absolutely need to collect a large amount of the right data to predict the growth of good or bad crops, and then consider how to gather the collected learning data. Therefore, we propose a data collection method based on metamodeling of Model Driven Architecture, which transforms heterogeneous data into a uniform learning data with model transformation rule. With this approach, we apply for easily customizing any prediction, and expect for even non-farmers to use any smart farm cultivation.

The anomalous connection of umbilical vessels to the heart is rare and has not yet been reported in the international scientific literature. Herein, we report the case of a newborn who was diagnosed with an anomalous connection of the umbilical vessels to the left ventricle. These anomalous vessels were functionally open for 2 weeks, and cellulitis was present in the area of the blood vessels connected to the skin. We performed division of these abnormal vessels and removal of the skin lesion.

Highlights • 19 patients (24%) were treated with ECMO among 80 mechanical ventilation-supported patients. • Weaning and mortality rate of ECMO was 42% (8/19) and 58% (10/19), respectively. • Despite the known low case-fatality rate of COVID-19, mortality rate of ECMO-treated patients was substantial., Background The COVID-19 pandemic has caused an epidemic of critical patients, some of whom have been treated with extracorporeal membrane oxygenation (ECMO). This purpose of study is to describe the clinical course of COVID-19 patients treated with ECMO. Methods A multicentered study of critical patients with COVID-19 treated at six hospitals in Daegu was conducted between January and April 2020. Results Among the 80 patients receiving mechanical ventilation support, 19 (24%) were treated with ECMO included (median age 63.0 years). Eight of the 19 patients (42%) were weaned off ECMO (9.8 days, IQR 7.0-13.7). Among them, four patients were also weaned off mechanical ventilation (33.4 days, IQR 29.3 - 35.7), three were still receiving mechanical ventilation (50.9 days), and one expired after ECMO weaning. According to the univariate analysis, the factor that was associated with successful ECMO weaning was vitamin B12 treatment (p = 0.028). Conclusions During the COVID-19 epidemic, ECMO weaning and mortality rates were 42% and 58%, respectively.

Recently, a photovoltaic energy integrated monitoring system may happen a serious problem with a little error. After constructing the complete solar power monitoring system, this is, a kind of safety-critical system, it should consider how to completely validate it based on requirements of this system. For even code based test coverage in safety critical area, it must achieve 100% of Path and MC/DC coverage on dynamic analysis. To do this, we suggest to automatic test generation on Model Driven Approach to ensure 100% functional requirement coverage using minimal test cases. More important idea is to generate an image (of test case) with an image (of sequence diagram) based on automatic multimedia image translation processing, but not use an algorithmic method in the old fashion. Our approach is focusing on validating the dynamic behaviors of the safety system, which generate test cases based on sequence diagram, that is, use case scenario to design the dynamic behaviors of the solar power monitoring system. As a result, it can validate the safety critical system with minimal test cases.

Ion-exchange chromatography can be used to effectively replace the lithium ion of LiMo3Se3 with a proton. The enlargement of the Stern layer distance caused by this ion exchange improves the dispersibility of (Mo3Se3−)∞ chains and also prevents the re-bundling and aggregation of nanowires in aqueous solutions, even at high concentrations (1 mg mL−1).

The synthesis and nanoscale dispersion of a new one-dimensional (1D) material, V2Se9, in which chain-shaped molecular units with strong covalent bonds are assembled in a crystal structure via weak van der Waals attraction between chains, were successfully carried out. V2Se9 is synthesized by solid-state reaction and additional heat treatment. The synthesized V2Se9 has excellent thermal stability up to 400 °C and has been experimentally confirmed to be dispersed up to ∼20 nm or less through a specific solvent dispersion. The covalently bonded V2Se9 chain, when isolated from its bulk material, is expected to exhibit unique quantum physical properties owing to the confinement of electrons in the 1D chain structure and the absence of inter-chain interactions, as demonstrated in the case of graphene and other 2D materials. Therefore, the novel 1D material of V2Se9, as an extension of the current 2D material, is expected to create a new class of materials that will be of significant interest to the materials science and nanotechnology communities for new device applications.

In requirement engineering, an important issue is how to transform and tailor the informal system requirements of users or customers into more structured specification documents, which are then used by the software developers. In addition, it is both challenging and necessary to redefine and analyze, from ill-defined or unknown requirements, specifications correctly and automatically generate test cases with them. There are few kinds of research in Korea for automatically reducing requirement complexity and developing test cases of the Korean language-based requirement specifications. Why do we need requirement simplification? Requirement complexity causes analyzers less readability and low understandability. To do this, we propose the automatic cause-effect generation via a requirement simplification mechanism of informal requirement specifications with the Korean language, which works the following procedures: (1) the automatic simplification of informal requirement sentences, (2) the generation of Condition/Conjunction/Clause Tree (C3Tree) Model, (3) and the Cause-effect generation.

Ion-exchange chromatography can be used to effectively replace the lithium ion of LiMo3Se3 with a proton. The enlargement of the Stern layer distance caused by this ion exchange improves the dispersibility of (Mo3Se3-)∞ chains and also prevents the re-bundling and aggregation of nanowires in aqueous solutions, even at high concentrations (1 mg mL-1).

Two-dimensional transition-metal dichalcogenides (TMDs) have a strain-sensitive nature and can only exhibit in-plane piezoelectricity, owing to their in-plane inversion symmetry breaking, which limits their practical applications for vertical stimulations. In this study, we demonstrated the capability of focused ion beams to create out-of-plane piezoelectricity on multi-layered MoTe2. We utilized a focused helium ion beam to selectively pattern the out-of-plane piezoelectricity via defect engineering in a layered MoTe2 flake. The generated out-of-plane piezoelectricity in the desired area was quantitatively examined using atomic force microscopy, and ion beam irradiation-induced defect formation that gave rise to inversion symmetry breaking was confirmed. These results indicated that the out-of-plane piezoelectricity can be selectively patterned through a focused helium ion beam, and it is expected that this approach can also be applied to other classes of TMDs and can expand the application fields of TMD-based devices.

Williams syndrome (WS) is a developmental disorder characterized by vascular abnormalities such as thickening of the vascular media layer in medium- and large-sized arteries. Supravalvular aortic stenosis (SVAS) and peripheral pulmonary artery stenosis (PPAS) are common vascular abnormalities in WS. The natural course of SVAS and PPAS is variable, and the timing of surgery or intervention is determined according to the progression of vascular stenosis. In our patient, SVAS and PPAS showed rapid concurrent progression within two weeks after birth. We report the early manifestation of SVAS and PPAS in the neonatal period and describe the surgical treatment for stenosis relief.

The optimum solvent for Nb2Se9 dispersion, which is a new type of one dimensional (1D) material, is investigated. Among several solvents (16 solvents in total), strong dispersion was observed in benzyl alcohol, isopropyl alcohol, isobutyl alcohol, and diacetone alcohol, which have medium dielectric constants in the range of 10 to 30 and surface tension in the range of 25 to 35 mJ m−2. 1D Nb2Se9 chains, whose size is less than 10 nm, are well dispersed and it is possible to disperse mono-chains of 1 nm or less in a specific dispersion region. The 1D unit chain with dangling bond free surface and high volume to area ratio is expected to be used in applications that utilize the surface of the material. Such dispersion is an important first step towards various potential applications and is an indispensable scientific goal for the practical applications of Nb2Se9.

Rare-earth nickelates have received great attention owing to the extreme sensitivity of their metal-insulator transition (MIT) and particularly the local defect state under external perturbation. Accordingly, it is critical to effectively control their local defect state to tailor the MIT. However, although macroscopic MIT behavior has been extensively studied, the relationship between the local defect state related to polar discontinuity and MIT has been rarely investigated. Herein, we demonstrate the presence of intrinsic conductive nanochannels due to the Ni deficiency induced by the polar discontinuity and the flexoelectric healing of such nanochannels in NdNiO3 thin films using atomic force microscopy (AFM). The results indicate that the intrinsic conductive nanochannels are likely related to the Ni vacancy. Intriguingly, these conductive nanochannels are effectively removed by the application of mechanical force with the AFM tip, i.e., flexoelectric healing. Our findings suggest that mechanical stimuli can be one of the effective ways for modulating the intrinsic defect state and the corresponding properties at the nanoscale.

The synthesis and nanoscale dispersion of a new one-dimensional (1D) material, V

The optimal surgical repair technique for coarctation associated with aortic arch hypoplasia (CoA-AAH) in neonates and infants is controversial. This study evaluates our current strategy using extended end-to-side anastomosis under selective cerebral and myocardial perfusion in treating this group of patients. Through a retrospective review, we analyzed the outcome of 87 infants who underwent surgical repair of CoA-AAH from January 2004 to December 2015. Patients with functional single ventricle were excluded. There were no early mortalities, and 4 patients (4.6%) experienced early complications. Eighty-five patients (97.7%) were followed up during a mean duration of 6.1 ± 3.53 years. There were 2 late mortalities (2.3%) and 3 reintervention (3.5%) of the aortic arch. Ten-year overall survival and freedom from reintervention for the entire cohort was 97.7% and 96.3%, respectively. At last follow-up, 4 patients (4.5%) showed a peak velocity greater than 2.5 m/s across the repair site. Seven patients (8.2%) were hypertensive. Our strategy with extended end-to-side anastomosis under selective cerebral and myocardial perfusion is safe and effective for repairing CoA-AAH in neonates and infants. Concomitant repair of associated cardiac anomalies can be done without added risk. Mid-term results are excellent with low rates of mortality, reintervention, and late hypertension.

The half-turned truncal switch (HTTS) operation has been reported as an alternative to the Rastelli or réparation à l’étage ventriculaire procedures. HTTS prevents left ventricular outflow tract (LVOT) obstruction in patients with complete transposition of the great arteries (TGA) with a ventricular septal defect (VSD) and pulmonary stenosis (PS), or in those with a Taussig-Bing anomaly with PS. The advantages of the HTTS procedure are avoidance of late LVOT or right ventricular outflow tract (RVOT) obstruction, and of overstretching of the pulmonary artery. We report the case of a patient who underwent HTTS for TGA with VSD and PS, in whom there was no LVOT obstruction and only mild aortic regurgitation and mild RVOT obstruction, including observations at 12-year follow-up. Our experience with long-term follow-up of HTTS supports a solution for late complications after the Rastelli procedure.

Recently, in the photovoltaic energy integrated monitoring software system, it has more complex, and accordingly may be possible to occur more errors. In this industrial services, a small error can lead to a huge accident to make the power failures. To completely build this system, it should verify whether it is or not stability of software through measuring the full coverage with generating test cases in detail level based on a message sequence model. In this paper, we apply to verify a system stability of this monitoring system with our previous research such as the automatic test case generation based on UML 2.4.1 message-sequence diagram via cause-effect diagram. With this, we extract automatically test cases on coverage.

For safe software development on the solar integrated monitoring system, it is very important how to identify safe behaviors of the system behaviors. Therefore, it needs to test the system behaviors after the software development. To solve this problem, the existing studies have proposed the use case based test coverage analysis at all software development stages [1]. With this method, we identify the test cases based on priority of the system behaviors. In this paper, we proposes automatic test case extraction method based on state diagram among the use case-based test coverage extraction methods. That is, we can use state diagram for a system behaviors with which generates test cases to validate the system. We show an applicative case on the system behaviors of a solar integrated system with this approach.