Hemorrhagic Transformation of Ischemic Stroke: Severe Complications of Prosthetic Valve Endocarditis

Ischemic stroke is a common complication of infective endocarditis (IE), occurring in 20-40% of left side IE cases. In these subsets, anticoagulation therapy may provoke hemorrhagic transformation (HT) of ischemic stroke, and complications of this magnitude deteriorate the clinical course for IE patients. However, in cases of IE complicated with a mechanical prosthetic valve, the physician can be concerned over the maintenance of anticoagulation due to the risk of thrombotic complication. According to our retrospective review, HT of ischemic stroke in prosthetic valve endocarditis occurred 13.8% (4/29) of the time in a variety of situations. Some of these even arose in patients with a subtherapeutic range of prothrombin time

Validation of Submaximal Step Tests and the 6-Min Walk Test for Predicting Maximal Oxygen Consumption in Young and Healthy Participants.

Background: This study aimed to test the validity of three different submaximal tests (i.e., 3-min step test with 20.3-cm step box height (3MST20), 3-min step test with 30-cm step box height (3MST30), and 6-min walk test (6MWT)) in estimating maximal oxygen consumption (VO2max) in young and healthy individuals. Methods: The 3MST20, 3MST30, 6MWT, as well as the cardiopulmonary exercise test (CPET) were performed in 73 participants (37 men and 36 women; mean age: 30.8 ± 9.3 years). All participants visited the clinic three times in a random order for anthropometric measurements, three submaximal tests, and the VO2max test. Multiple linear regression analyses were conducted to construct the VO2max prediction equations for each submaximal test. Results: The prediction equations developed based on multiple regression analyses for each submaximal tests were as follows: 3MST20: VO2max = 86.0 - 10.9 × sex (male = 1, female = 2) - 0.4 × age - 0.1 × weight - 0.1 × heart rate recovery at 30 s (HRR30s); 3MST30: VO2max = 84.5 - 10.2 × sex (male = 1, female = 2) - 0.4 × age - 0.1 × weight - 0.1 × HRR30s; and 6MWT: VO2max = 61.1 - 11.1 × sex (male = 1, female = 2) - 0.4 × age - 0.2 × weight - 0.2 × (distance walked·10-1). The estimated VO2max values based on formulated equations were 37.0 ± 7.9, 37.3 ± 7.6, and 36.9 ± 7.9 mL∙kg-1∙min-1 derived from the 3MST20, 3MST30, and 6MWT, respectively. These estimated VO2max values were not significantly different from the measured VO2max value, 37.3 mL∙kg-1∙min-1. The estimated VO2max based on the 3MST20, 3MST30, and 6MWT results explained 73.4%, 72.2%, and 74.4% of the variances in the measured VO2max (p < 0.001), respectively. Conclusions: The 3MST20, 3MST30, and 6MWT were valid in estimating VO2max in relatively young and healthy Asian individuals

Imaging Findings of Castleman's Disease Localized in the Axilla: A Case Report

Castleman's disease is a rare benign lymphoproliferative disorder of uncertain origin which most commonly involves the mediastinum but rarely affects the axilla. We report a case of localized Castleman's disease involving the axillary lymph node. Mammography revealed a well-defined, homogeneously dense ovoid mass, 3 cm in size, in the left axilla, while gray-scale ultrasonography (US) demonstrated a well-defined, uniformly hypoechoic ovoid mass with good through transmission. Peripheral hypervascularity was observed at power Dopper US, and early rapid homogeneous enhancement at contrast-enhanced dynamic CT

Role of oxygen vacancies in ferroelectric or resistive switching hafnium oxide

HfO2 shows promise for emerging ferroelectric and resistive switching (RS) memory devices owing to its excellent electrical properties and compatibility with complementary metal oxide semiconductor technology based on mature fabrication processes such as atomic layer deposition. Oxygen vacancy (Vo), which is the most frequently observed intrinsic defect in HfO2-based films, determines the physical/electrical properties and device performance. Vo influences the polymorphism and the resulting ferroelectric properties of HfO2. Moreover, the switching speed and endurance of ferroelectric memories are strongly correlated to the Vo concentration and redistribution. They also strongly influence the device-to-device and cycle-to-cycle variability of integrated circuits based on ferroelectric memories. The concentration, migration, and agglomeration of Vo form the main mechanism behind the RS behavior observed in HfO2, suggesting that the device performance and reliability in terms of the operating voltage, switching speed, on/off ratio, analog conductance modulation, endurance, and retention are sensitive to Vo. Therefore, the mechanism of Vo formation and its effects on the chemical, physical, and electrical properties in ferroelectric and RS HfO2 should be understood. This study comprehensively reviews the literature on Vo in HfO2 from the formation and influencing mechanism to material properties and device performance. This review contributes to the synergetic advances of current knowledge and technology in emerging HfO2-based semiconductor devices.This work was supported by the National Research Foundation (NRF), funded by the Korean Ministry of Science and ICT (MSICT) (Grant Nos. 2020R1C1C1008193, 2022M3F3A2A01073562, 2021M3F3A2A02037889, 2021M3F3A2A01037738 and 2022R1C1C1004176), and the Korea Institute of Science and Technology (2E32491 and 2V09802)

Direct Synthesis of Molybdenum Phosphide Nanorods on Silicon Using Graphene at the Heterointerface for Efficient Photoelectrochemical Water Reduction

MoP nanorod-array catalysts were directly synthesized on graphene passivated silicon photocathodes without secondary phase. Mo-O-C covalent bondings and energy band bending at heterointerfaces facilitate the electron transfer to the reaction sites. Numerous catalytic sites and drastically enhanced anti-reflectance of MoP nanorods contribute to the high solar energy conversion efficiency. Abstract Transition metal phosphides (TMPs) and transition metal dichalcogenides (TMDs) have been widely investigated as photoelectrochemical (PEC) catalysts for hydrogen evolution reaction (HER). Using high-temperature processes to get crystallized compounds with large-area uniformity, it is still challenging to directly synthesize these catalysts on silicon photocathodes due to chemical incompatibility at the heterointerface. Here, a graphene interlayer is applied between p-Si and MoP nanorods to enable fully engineered interfaces without forming a metallic secondary compound that absorbs a parasitic light and provides an inefficient electron path for hydrogen evolution. Furthermore, the graphene facilitates the photogenerated electrons to rapidly transfer by creating Mo-O-C covalent bondings and energetically favorable band bending. With a bridging role of graphene, numerous active sites and anti-reflectance of MoP nanorods lead to significantly improved PEC-HER performance with a high photocurrent density of 21.8 mA cm−2 at 0 V versus RHE and high stability. Besides, low dependence on pH and temperature is observed with MoP nanorods incorporated photocathodes, which is desirable for practical use as a part of PEC cells. These results indicate that the direct synthesis of TMPs and TMDs enabled by graphene interlayer is a new promising way to fabricate Si-based photocathodes with high-quality interfaces and superior HER performance. Graphic Abstrac

Clinical Outcomes and Adverse Events of Gastric Endoscopic Submucosal Dissection of the Mid to Upper Stomach under General Anesthesia and Monitored Anesthetic Care

Background/Aims Endoscopic submucosal dissection (ESD) of gastric tumors in the mid-to-upper stomach is a technically challenging procedure. This study compared the therapeutic outcomes and adverse events of ESD of tumors in the mid-to-upper stomach performed under general anesthesia (GA) or monitored anesthesia care (MAC). Methods Between 2012 and 2018, 674 patients underwent ESD for gastric tumors in the midbody, high body, fundus, or cardia (100 patients received GA; 574 received MAC). The outcomes of the propensity score (PS)-matched (1:1) patients receiving either GA or MAC were analyzed. Results The PS matching identified 94 patients who received GA and 94 patients who received MAC. Both groups showed high rates ofen bloc resection (GA, 95.7%; MAC, 97.9%; p=0.68) and complete resection (GA, 81.9%; MAC, 84.0%; p=0.14). There were no significant differences between the rates of adverse events (GA, 16.0%; MAC, 8.5%; p=0.18) in the anesthetic groups. Logistic regression analysis indicated that the method of anesthesia did not affect the rates of complete resection or adverse events. Conclusions ESD of tumors in the mid-to-upper stomach at our high-volume center had good outcomes, regardless of the method of anesthesia. Our results demonstrate no differences between the efficacies and safety of ESD performed under MAC and GA

Prevalence and risk factors of the metabolic syndrome in young adults with childhood-onset hypopituitary growth hormone deficiency

PurposeThis study evaluated the prevalence of the metabolic syndrome (MetS) and risk factors for metabolic derangement in young adults with childhood-onset hypopituitary growth hormone deficiency (ACOHGHD).MethodsThirty patients with ACOHGHD who were treated with hormone-replacement therapy, aged 18 to 29 years, who visited the Seoul National University Children's Hospital between September 2009 and February 2010 were enrolled. Height, weight, waist circumference, hip circumference, and blood pressure were measured, and the clinical and hormonal features were reviewed retrospectively. We evaluated measures of metabolic derangement in the enrolled patients and in the data of healthy adults aged 20 to 29 years taken from the 2005 Korean National Health and Nutrition Examination Survey (KNHANES) as part of the National Cholesterol Education Program-the Adult Treatment Panel III.ResultsCompared with the KNHANES participants, patients with ACOHGHD had significantly large waist circumference (men and women), high systolic blood pressure (BP) (women) and diastolic BP (men), and high serum triglyceride levels (women). The duration of illness correlated significantly with central obesity (r2=0.546, P=0.003). The prevalence of MetS was 10% in patients with ACOHGHD and 2.3% in KNHANES participants. The prevalence of central obesity and MetS was higher in patients with ACOHGHD than in KNHANES participants (P<0.001 and P=0.042, respectively).ConclusionAbdominal obesity correlated with the duration of illness in patients with ACOHGHD. Waist circumference should be measured in the clinic to prevent MetS, particularly in patients with a long history of ACOHGHD, regardless of age or sex

2009 H1N1 influenza virus infection and necrotizing pneumonia treated with extracorporeal membrane oxygenation

A 3-year-old girl with acute respiratory distress syndrome due to a H1N1 2009 influenza virus infection was complicated by necrotizing pneumonia was successfully treated with extracorporeal membrane oxygenation (ECMO). This is the first reported case in which a pediatric patient was rescued with ECMO during the H1N1 influenza epidemic in Korea in 2009

Sirolimus- Versus Paclitaxel-Eluting Stents for the Treatment of Coronary Bifurcations Results From the COBIS (Coronary Bifurcation Stenting) Registry

ObjectivesWe aimed to compare the long-term clinical outcomes of patients treated with sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES) for coronary bifurcation lesions.BackgroundThere are limited data regarding comparisons of SES and PES for the treatment of bifurcation lesions.MethodsPatients who received percutaneous coronary intervention for non-left main bifurcation lesions were enrolled from 16 centers in Korea between January 2004 and June 2006. We compared major adverse cardiac events (MACE [cardiac death, myocardial infarction, or target lesion revascularization]) between the SES and PES groups in patients overall and in 407 patient pairs generated by propensity-score matching.ResultsWe evaluated 1,033 patients with bifurcation lesions treated with SES and 562 patients treated with PES. The median follow-up duration was 22 months. Treatment with SES was associated with a lower incidence of MACE (hazard ratio [HR]: 0.53, 95% confidence interval [CI]: 0.32 to 0.89, p < 0.01) and target lesion revascularization (HR: 0.55, 95% CI: 0.31 to 0.97, p = 0.02), but not of cardiac death (HR: 2.77, 95% CI: 0.40 to 18.99, p = 0.62) and cardiac death or myocardial infarction (HR: 0.97, 95% CI: 0.38 to 2.49, p = 0.94). After propensity-score matching, patients with SES still had fewer MACE and target lesion revascularization incidences than did patients with PES (HR: 0.52, 95% CI: 0.30 to 0.91, p = 0.02, and HR: 0.48, 95% CI: 0.25 to 0.91, p = 0.02, respectively). There was no significant difference in the occurrences of stent thrombosis between the groups (0.7% vs. 0.7%, p = 0.94).ConclusionsIn patients with bifurcation lesions, the use of SES resulted in better long-term outcomes than did the use of PES, primarily by decreasing the rate of repeat revascularization. (Coronary Bifurcation Stenting Registry in South Korea [COBIS]; NCT00851526