Rate-dependent inhomogeneous-to-homogeneous transition of plastic flows during nanoindentation of bulk metallic glasses: Fact or artifact?

There has been considerable controversy over the "apparent" rate-dependent transition from inhomogeneous-to-homogeneous flow during nanoindentation of bulk metallic glasses (BMGs) at room temperature: whether it arises from the existence of homogeneous-flow regime in BMG deformation map or is an artifact due to the instrumental blurring at high rates. To provide a clue to address this dispute, the authors performed nanoindentation experiments on a Zr-based BMG with two geometrically self-similar indenters. The results are discussed in terms of the discrete plasticity ratio, which is a useful parameter in analyzing the contribution of inhomogeneous plasticity to the total plastic deformation.open232

Electro-Mechanical Safety Testing of Portable ECG Devices for Home Healthcare Usage

OBJECTIVES: This paper suggests the experimental guidelines to evaluate the electro-mechanical safety of belt type equipment. The electro-mechanical safety was determined by using the International Electrotechnical Commission guidelines, which are widely used as important factors for assessing the electro-mechanical safety of belt type equipment. However, the local guidelines on wearable healthcare sensors are currently not well-established. Therefore, safety guidelines suited for the actual circumstances in Korea are required, and this paper attempts to try a new experimental safety test procedure of the wearable healthcare sensor. METHODS: This belt type device measures the electrocardiogram (ECG) and heart rates by attaching to the chest. Examination lists were selected by analyzing the common standards ofelectro-mechanical safety (IEC 60601-1) and environment tests (IEC 60068-1, IEC 60068-2) of home-healthcare equipment. RESULTS: The essential electrical safety, which was required for the RS300G3 as a medical device, was evaluated, and most of the examination lists were selected by considering the circumstances of the users. The device passed all the selected examinable lists that are applicable to the Korean environment. CONCLUSIONS: This study has limitations to estimate and to conduct electro-mechanical safety experiments because our study focused on the belt type of heart-rates equipment. We are not taking into account the overall electro-mechanical home-healthcare measurements. According to industrial and technological development, there are infinite possibilities for the advancement of home-healthcare equipment, so more examination lists for safety are being added in addition to what we have doneope

Impact of successful restoration of sinus rhythm in patients with atrial fibrillation and acute heart failure: Results from the Korean Acute Heart Failure registry

Background: Restoring and maintaining sinus rhythm (SR) in patients with atrial fibrillation (AF) failed to show superior outcomes over rate control strategies in prior randomized trials. However, there is sparse data on their outcomes in patients with acute heart failure (AHF).Methods: From December 2010 to February 2014, 5,625 patients with AHF from 10 tertiary hospitals were enrolled in the Korean Acute Heart Failure registry, including 1,961 patients whose initial electrocardiogram showed AF. Clinical outcomes of patients who restored SR by pharmacological or electrical cardioversion (SR conversion group, n = 212) were compared to those of patients who showed a persistent AF rhythm (AF persistent group, n = 1,662).Results: All-cause mortality both in-hospital and during the follow-up (median 2.5 years) were significantly lower in the SR conversion group than in the AF persistent group after adjustment for risk factors (adjusted hazard ratio [HR]; 95% confidence interval [CI] = 0.26 [0.08–0.88], p = 0.031 and 0.59 [0.43–0.82], p = 0.002, for mortality in-hospital and during follow-up, respectively). After 1:3 propensity score matching (SR conversion group = 167, AF persistent group = 501), successful restoration of SR was associated with lower all-cause mortality (HR [95% CI] = 0.68 [0.49–0.93], p = 0.015), heart failure rehospitalization (HR [95% CI] = 0.66 [0.45–0.97], p = 0.032), and composite of death and heart failure rehospitalization (HR [95% CI] = 0.66 [0.51–0.86], p = 0.002).Conclusions: Patients with AHF and AF had significantly lower mortality in-hospital and during follow-up if rhythm treatment for AF was successful, underscoring the importance of restoring SR in patients with AHF

Characteristics, Outcomes and Predictors of Long-Term Mortality for Patients Hospitalized for Acute Heart Failure: A Report From the Korean Heart Failure Registry

BACKGROUND AND OBJECTIVES: Acute heart failure (AHF) is associated with a poor prognosis and it requires repeated hospitalizations. However, there are few studies on the characteristics, treatment and prognostic factors of AHF. The aims of this study were to describe the clinical characteristics, management and outcomes of the patients hospitalized for AHF in Korea. SUBJECTS AND METHODS: We analyzed the clinical data of 3,200 hospitalization episodes that were recorded between June 2004 and April 2009 from the Korean Heart Failure (KorHF) Registry database. The mean age was 67.6±14.3 years and 50% of the patients were female. RESULTS: Twenty-nine point six percent (29.6%) of the patients had a history of previous HF and 52.3% of the patients had ischemic heart disease. Left ventricular ejection fraction (LVEF) was reported for 89% of the patients. The mean LVEF was 38.5±15.7% and 26.1% of the patients had preserved systolic function (LVEF ≥50%), which was more prevalent in the females (34.0% vs. 18.4%, respectively, p<0.001). At discharge, 58.6% of the patients received beta-blockers (BB), 53.7% received either angiotensin converting enzyme-inhibitors or angiotensin receptor blockers (ACEi/ARB), and 58.4% received both BB and ACEi/ARB. The 1-, 2-, 3- and 4-year mortality rates were 15%, 21%, 26% and 30%, respectively. Multivariate analysis revealed that advanced age {hazard ratio: 1.023 (95% confidence interval: 1.004-1.042); p=0.020}, a previous history of heart failure {1.735 (1.150-2.618); p=0.009}, anemia {1.973 (1.271-3.063); p=0.002}, hyponatremia {1.861 (1.184-2.926); p=0.007}, a high level of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) {3.152 (1.450-6.849); p=0.004} and the use of BB at discharge {0.599 (0.360-0.997); p=0.490} were significantly associated with total death. CONCLUSION: We present here the characteristics and prognosis of an unselected population of AHF patients in Korea. The long-term mortality rate was comparable to that reported in other countries. The independent clinical risk factors included age, a previous history of heart failure, anemia, hyponatremia, a high NT-proBNP level and taking BB at discharge.ope

Optical Shaping of Plasma Cavity for Controlled Laser Wakefield Acceleration

Laser wakefield accelerators rely on relativistically moving micron-sized plasma cavities that provide extremely high electric field >100GV/m. Here, we demonstrate transverse shaping of the plasma cavity to produce controlled sub-GeV electron beams, adopting laser pulses with an axially rotatable ellipse-shaped focal spot. We showed the control capability on electron self-injection, charge, and transverse profile of the electron beam by rotating the focal spot. We observed that the effect of the elliptical focal spot was imprinted in the profiles of the electron beams and the electron energy increased, as compared to the case of a circular focal spot. We performed 3D particle-in-cell (PIC) simulations which reproduced the experimental results and revealed dynamics of a new asymmetric self-injection process. This simple scheme offers a novel control method on laser wakefield acceleration to produce tailored electron beams and x-rays for various applications.Comment: 5 pages, 5 figure

Role of age and sex in determining antibiotic resistance in febrile urinary tract infections

SummaryObjectivesTo identify the age- and sex-specific antimicrobial susceptibility patterns of Gram-negative bacteria (GNB) in outpatient febrile urinary tract infections (UTIs) in Korea.MethodsA total 2262 consecutive samples collected from patients aged 1–101 years with febrile UTIs, during the period January 2012 to December 2014, were analyzed in this multicentre, retrospective cohort study.ResultsThe sensitivities to cefotaxime and cefoxitin were over 85% for females but under 75% for males. Sex played an important role in the susceptibility of GNB to cefotaxime (p<0.001) and cefoxitin (p<0.001). The sensitivity to ciprofloxacin (age >20 years) was under 75% in both sexes, and was not influenced by sex (p=0.204). Age distributions of the incidences of resistance to cefotaxime, cefoxitin, and ciprofloxacin (age >20 years) were similar to the age distribution of the incidence of GNB, which indicates that the resistance patterns to these drugs were not affected by age (Kolmogorov–Smirnov test, female/male: p=0.927/p=0.509, p=0.193/p=0.911, and p=0.077/p=0.999, respectively).ConclusionsAge is not a considerable factor in determining the antibiotic resistance in febrile UTIs. Ciprofloxacin should be withheld from both sexes until culture results indicate its use. Second- or third-generation cephalosporins such as cefoxitin and cefotaxime can be used empirically only in females

Sasangin diagnosis questionnaire: test of reliability,”

ABSTRACT Background: The concept of Sasang Constitutional Medicine (SCM) has been in existence in Traditional Korean Medicine for more than 100 years. It is of great importance that the Sasang constitution type be determined accurately before any therapeutic treatment. Objectives: Reliability analyse were carried out to evaluate the Sasangin Diagnosis Questionnaire (SDQ). Design: The data were collected through multi-center research in collaboration with the Departments of SCM in the nine Korean Colleges of Oriental Medicine. The internal consistency test and the test-retest method were applied in the reliability analysis. Subjects: The test-retest data of 88 respondents were used to analyze the reliability. The internal consistency reliability analysis was carried out using the data collected from 423 respondents. Results: The test-retest reliability was examined using the Pearson&apos;s correlation coefficients, which ranged from 0.44 to 0.74. The chi-square test results showed that there were five independent items in the retest that demanded careful attention. The Cronbach&apos;s alpha coefficient showed that all items were acceptable. Conclusions: All the categories of SDQ can be accepted as being reliable scales

Electron energy increase in a laser wakefield accelerator using up-ramp plasma density profiles

The phase velocity of the wakefield of a laser wakefield accelerator can, theoretically, be manipulated by shaping the longitudinal plasma density profile, thus controlling the parameters of the generated electron beam. We present an experimental method where using a series of shaped longitudinal plasma density profiles we increased the mean electron peak energy more than 50%, from 175 +/- 1 MeV to 262 +/- 10 MeV and the maximum peak energy from 182 MeV to 363 MeV. The divergence follows closely the change of mean energy and decreases from 58.9 +/- 0.45 mrad to 12.6 +/- 1.2 mrad along the horizontal axis and from 35 +/- 0.3 mrad to 8.3 +/- 0.69 mrad along the vertical axis. Particle-in-cell simulations show that a ramp in a plasma density profile can affect the evolution of the wakefield, thus qualitatively confirming the experimental results. The presented method can increase the electron energy for a fixed laser power and at the same time offer an energy tunable source of electrons.© The Author(s) 201