Analysis of Problems in Cut Slope Survey and Design Based on Case Studies

In construction of roads or large residential complexes, the formation of large scale cut slopes is inevitable due to the large proportion of mountains in Korea. The problems involving the slope stability has emerged as a major concern. Inaccurate subsurface exploration can result in slope failure during or after the construction, thereby increasing the construction cost and delaying the construction duration. This study reviews problems involving the cut slope survey methods, design criteria, and examining the collapse mechanisms through various case studies. This study suggests the optimum survey methods and design criteria based on the possible failure mechanisms

Microspinning: Local Surface Mixing via Rotation of Magnetic Microparticles for Efficient Small-Volume Bioassays

The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy

A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γ levels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific

Background 18F-FDG uptake in positron emission mammography (PEM): Correlation with mammographic density and background parenchymal enhancement in breast MRI

AbstractWe aimed to determine whether background 18F-FDG uptake in positron emission mammography (PEM) was related to mammographic density or background parenchymal enhancement in breast MRI.MethodsWe studied a total of 52 patients (mean age, 50.9 years, 26 premenopausal, 26 postmenopausal) with newly diagnosed breast cancer who underwent 18F-FDG PEM (positron emission mammography), conventional mammography and breast MRI. The background mean 18F-FDG uptake value on PEM was obtained by drawing a user-defined region of interest (ROI) in a normal area of the contralateral breast. We reviewed the mammography retrospectively for overall breast density of contralateral breast according to the four-point scale (grade 1–4) of the Breast Imaging Reporting and Data System (BI-RADS) classification. The background parenchymal enhancement of breast MRI was classified as minimal, mild, moderate, or marked. All imaging findings were interpreted by two readers in consensus without knowledge of image findings of other modalities.ResultsMultiple linear regression analysis revealed a significant correlation between background 18F-FDG uptake on PEM and mammographic density after adjustment for age and menopausal status (P<0.01), but not between background 18F-FDG uptake on PEM and background parenchymal enhancement on MRI.ConclusionBackground 18F-FDG uptake on PEM significantly increases as mammographic density increases. Background parenchymal enhancement in breast MRI was not an independent predictor of the background 18F-FDG uptake on PEM unlike mammographic density

Silver Direct Electrodeposition on Ru Thin Films

Electrodeposition of Ag was performed on Ru thin films following electrochemical reduction of native Ru oxide. Oxide reduction in a tetramethylammonium hydroxide solution was critical for the formation of continuous Ag film, and a large overpotential was important for high-density nucleation. From a kinetics viewpoint, the thermal stability of the Ag film was improved by the application of a more negative potential, which suggested that better nucleation density at the initial stage of growth induced better substrate adhesion. Suppression of growth by addition of an organic additive generated a larger and more uniformly distributed initial population of Ag particles, and as a result a smooth film was obtained.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage (RCECS), the Institute of Chemical Processing (ICP) in Seoul National University, and Dongbu HiTek

Two-step filling in Cu electroless deposition using a concentration-dependent effect of 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid

This paper describes electroless Cu filling of trenches with different widths ranging from 130 to 300 nm, using a concentrationdependent effect of 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid DPS . With a fixed DPS concentration, it is shown that these trenches with different dimensions cannot be superfilled simultaneously. This is presumably caused by different surface concentrations of the adsorbed additive, which depends on the feature size and surface area. A two-step filling method is employed to superfill those trenches, which is also effective in control of the deposited Cu amounts to obtain uniform growth front regardless of the trench dimensions.This work was supported by a Korea Research Foundation grant funded by the Korean Government MOEHRD grant no. KRF- 2006-352-D00052 . The authors are grateful for the support of the Research Center for Energy Conversion and Storage RCECS , Dongbu HiTek Company, Ltd., and the Institute of Chemical Processes ICP

Spin Fluctuation and Persistent Current in a Mesoscopic Ring Coupled to a Quantum Dot

We investigate the persistent current influenced by the spin fluctuations in a mesoscopic ring weakly coupled to a quantum dot. It is shown that the Kondo effect gives rise to some unusual features of the persistent current in the limit where the charge transfer between two subsystems is suppressed. Various aspects of the crossover from a delocalized to a localized dot limit are discussed in relation with the effect of the coherent response of the Kondo cloud to the Aharonov-Bohm flux.Comment: 4 pages, 2 figure

Association of smoking cessation after atrial fibrillation diagnosis on the risk of cardiovascular disease: a cohort study of South Korean men

While smoking elevates the risk for cardiovascular disease (CVD) among atrial fibrillation (AF) patients, whether smoking cessation after AF diagnosis actually leads to reduced CVD risk is unclear. We aimed to determine the association of smoking cessation after AF diagnosis with subsequent CVD Risk among South Korean men. This retrospective cohort study included 2372 newly diagnosed AF male patients during 2003–2012 from the Korean National Health Insurance Service database. Self-reported smoking status within 2 years before and after diagnosis date were determined, after which the participants were divided into continual smokers, quitters (smokers who quit after AF diagnosis), sustained-ex smokers (those who quit prior to AF diagnosis), and never smokers. Participants were followed up from 2 years after AF diagnosis until 31 December 2015 for CVD. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence interval (CIs) for CVD according to the change in smoking habits before and after AF diagnosis. The mean (standard deviation, minimum-maximum) age of the study subjects was 62.5 (8.6, 41–89) years. Among AF patients, quitters had 35% reduced risk (aHR 0.65, 95% CI 0.44–0.97) and never smokers had 32% reduced risk (aHR 0.68, 95% CI 0.52–0.90) for CVD compared to continual smokers (p for trend 0.020). Similarly, compared to continual smokers, quitters had 41% risk-reduction (aHR 0.59, 95% CI 0.35–0.99) and never smokers 34% risk-reduction (aHR 0.66, 95% CI 0.46–0.93) for total stroke (p for trend 0.047). Quitters had 50% reduction (aHR 0.50, 95% CI 0.27–0.94), sustained ex-smokers had 36% reduction (aHR 0.64, 95% CI 0.42–0.99), and never smokers had 39% reduction (aHR 0.61, 95% CI 0.41–0.91) in ischemic stroke risk (p for trend 0.047). The risk-reducing effect of quitting on CVD risk tended to be preserved regardless of aspirin or warfarin use. Smoking cessation after AF diagnosis was associated with reduced CVD, total stroke, and ischemic stroke risk

Radiologic Findings of Renal Hemangioma: Report of Three Cases

Renal hemangioma is an uncommon benign tumor which usually causes painless or painful gross hematuria. Its preoperative diagnosis is extremely difficult or even impossible

A Survey of Diabetic Educators and Patients for the Revision of Korean Food Exchange Lists

BackgroundFood exchange lists are one of the main methods of nutritional education. However, Korean food exchange lists have not been revised since 1994. Therefore, we surveyed the opinions of diabetes educators and patients with diabetes regarding the need for revision of the current food exchange lists.MethodsFor two weeks beginning on 10 March 2008, a 12-item questionnaire regarding the opinion and need for revision of the current food exchange lists was e-mailed to diabetes educators nationwide. Another 15-question survey was administered to patients with diabetes in 13 hospitals located in the Seoul and Gyeonggi regions of Korea.ResultsWe obtained survey responses from 101 diabetes educators and 209 patients; 65 (64.3%) of the educators answered that the current food exchange lists should be revised. The items that needed revision were the glycemic index, addition of new foods and reaffirmation of exchange standard amounts. The patients demanded specific education about choosing appropriate foods, a balanced meal plan, proper snacks, and dining intake.ConclusionOur survey results demonstrate the need to revise the Korean food exchange lists. This process should focus on glycemic index, the addition of new foods and reconfirmation of one exchange reference unit