A Study on the Interfacial Reactions between Gallium and Cu/Ni/Au(Pd) Multilayer Metallization.

This research introduces low-temperature soldering of Ga with practical metallization structures, namely, Cu/Ni/Pd and Cu/Ni/Au, applied to contemporary microelectronic packages. Through these multilayer configurations, the study investigates the stability of the Ni diffusion barrier by examining changes in the interfacial microstructure as Ni is consumed. The interfacial reactions are conducted across a temperature spectrum of 160, 200, 240, and 280 °C, with reaction durations ranging from 30 to 270 min. Valuable insights for low-temperature soldering with Ga are extracted from the data. At lower reaction temperatures, the presence of Ga-rich intermetallic compounds (IMCs), specifically GaxNi (x = 89 to 95 at%), on the Ga7Ni3 layer is notably confirmed. As the reaction temperature and duration increase, the gradual consumption of the Ni layer occurs. This gives rise to the formation of Ga-Cu IMCs, specifically CuGa2 and γ3-Cu9Ga4, beneath the Ga-Ni IMC layer. Concurrently, the gap between the Ga-Ni and Ga-Cu IMC layers widens, allowing molten Ga to infiltrate. The rate of Ga7Ni3 growth follows a time exponent ranging approximately from 1.1 to 1.7. This highlights the significant influence of interface reaction-controlled kinetics on Ga7Ni3 IMC growth. The activation energy for Ga7Ni3 growth is determined to be 61.5 kJ/mol. The growth of Ga7Ni3 is believed to be primarily driven by the diffusion of Ga atoms along grain boundaries, with the porous microstructure inherent in the Ga7Ni3 layer providing additional diffusion pathways.

Increasing trends in mortality and costs of infectious diseases in Korea: trends in mortality and costs of infectious diseases.

OBJECTIVES: In an era when the average life expectancy and overall mortality rate have improved, Korea remains at risk for infectious disease outbreaks that place substantial burdens on the healthcare system. This study investigated trends in mortality and the economic burden of infectious diseases. METHODS: Healthcare data from the Health Insurance Review and Assessment Service (2009-2019) and the Korean Statistics Information Service (1997-2019) were used. We selected 10 infectious disease groups (intestinal infections, tuberculosis, vaccine- preventable diseases, sepsis, viral hepatitis, HIV-related diseases, central nervous system infections, rheumatic heart diseases, respiratory tract infections, and arthropod-borne viral diseases). RESULTS: The age-standardized mortality rate for infectious diseases increased from 27.2 per 100,000 population in 1997 to 37.1 per 100,000 population in 2019 and has had an upward trend since 2004. During this same period, significant increases were seen in respiratory tract infections and among elderly persons, especially those aged ≥85 years. The costs for infectious diseases increased from 4.126 billion US dollar (USD) in 2009 to 6.612 billion USD in 2019, with respiratory tract infections accounting for 3.699 billion USD (69%). The annual cost per patient for visits for medical care due to infectious diseases increased from 131 USD in 2009 to 204 USD in 2019. CONCLUSIONS: Mortality among elderly persons and those with respiratory tract infections increased during the study period. The economic burden of infectious diseases has consistently increased, especially for respiratory tract infections. It is therefore essential to establish effective management policies that considers specific infectious diseases and patient groups.

Precautionary Behavior Practices and Psychological Characteristics of COVID-19 Patients and Quarantined Persons.

BACKGROUND: since the coronavirus disease (COVID-19) was first reported in 2019, South Korea has enforced isolation of patients with confirmed cases of COVID-19, as well as quarantine for close contacts of individuals diagnosed with COVID-19 and persons traveling from abroad, in order to contain its spread. Precautionary behavior practices and psychological characteristics of confirmed and quarantined persons were investigated for planning pandemic recovery and preparedness. METHODS: this study was conducted with 1716 confirmed patients and quarantined persons in Daegu and Busan, regions where a high number of cases were confirmed during the early stage of the COVID-19 outbreak in South Korea. We collected online survey data from 23 April to 20 May 2020, in Daegu, and 28 April to 27 May 2020, in Busan, in cooperation with Daegu and Busan Infectious Disease Control Centers and public health centers in the regions. COVID-19 symptoms, pre-cautionary behavior practices, psychological states, and the need for improvement in isolation/quarantine environments were examined using an online survey. RESULTS: compared to patients infected with coronavirus, quarantined persons engaged in more hygiene-related behaviors (e.g., hand washing, cough etiquette, and proper mask-wearing) and social distancing. COVID-19 patients had a strong fear of stigma, while quarantined persons had a strong fear of contracting COVID-19. Study participants responded that it was necessary to provide financial support and adequate information during isolation/quarantine. CONCLUSIONS: the study highlights the importance of precautionary behavior to prevent COVID-19 infection and the need to provide support (both psychological and financial) to patients and quarantined persons, to reinforce effective communication, social solidarity, and public health emergency preparedness (PHEP) in a pandemic situation.

Achieving over 15% Efficiency in Solution-Processed Cu(In,Ga)(S,Se)2 Thin-Film Solar Cells via a Heterogeneous-Formation-Induced Benign p-n Junction Interface.

Cu(In,Ga)(S,Se)2 (CIGS) thin-film solar cells have attracted considerable interest in the field of photovoltaic devices due to their high efficiency and great potential for diverse applications. While CdS has been the most favorable n-type semiconductor because of its excellent lattice-match and electronic band alignment with p-type CIGS, its narrow optical band gap (∼2.4 eV) has limited light absorption in underlying CIGS absorber films. Reducing the thickness of CdS films to increase the short-circuit current-density has been less effective due to the following decrease in the open-circuit voltage. To overcome this trade-off between the main parameters, we controlled the formation mechanism of CdS films in chemical bath deposition and established its direct correlation with the properties of p-n junctions. Interestingly, a heterogeneous CdS film formation was found to have a synergetic effect with its ammonia bath solution, effectively reducing charge carrier loss from the shunt paths and interface recombination of CIGS/CdS junctions. With these electrical benefits, the trade-off was successfully alleviated and our best device achieved a power conversion efficiency of 15.6%, which is one of the state-of-the-art CIGS thin-film solar cells prepared using solution-processing techniques.

Incidence and mortality of cervical cancer in Vietnam and Korea (1999-2017).

OBJECTIVES: Cervical cancer is a major disease burden in Vietnam. This study aimed to estimate the incidence and mortality rates of cervical cancer in Vietnam (1999-2017) in comparison to those in Korea, where a population-based cancer registry and national cervical cancer screening program have been implemented. METHODS: The estimated incidence and mortality of cervical cancer in Vietnam and Korea (1999-2017) were collected from Global Burden of Disease 2017 study. Estimated age-standardized rates (ASRs) in both countries were calculated utilizing the 1999-2017 population of each country and the World Health Organization standard population. The reported ASRs in Korea were also computed using data on incidence and mortality (1999-2017) and the Korean population from the Korea Statistical Information Service. RESULTS: In Vietnam, the estimated incidence and mortality of cervical cancer decreased annually by 0.84% and 1.01%. In Korea, the trend of reported incidence showed a dramatic drop (1999-2007 annual percent change [APC], -4.53%) before stably declining (2007-2017 APC, -2.71%). Reported mortality also significantly decreased (2003-2008 APC, -6.63%), and then maintained a stable decline (2008-2017 APC, -3.78%). The incidence and mortality rates were higher in Vietnam than in Korea. The declining trend of incidence and mortality in Vietnam was slower than the corresponding trends in Korea. CONCLUSIONS: A national screening program should be implemented for Vietnamese women aged over 30 to maintain, or even hasten, the decline in cervical cancer incidence and mortality. A population-based cancer registry may help monitor the effectiveness of a cervical cancer screening program.

Boosting Solar Cell Performance via Centrally Localized Ag in Solution-Processed Cu(In,Ga)(S,Se)2 Thin Film Solar Cells.

Fabrication of Cu(In,Ga)(S,Se)2 (CIGSSe) absorber films from environmentally friendly solutions under ambient air conditions for use in solar cells has shown promise for the low-cost mass production of CIGSSe solar cells. However, the limited power conversion efficiency (PCE) of these solar cells compared with their vacuum-processed counterparts has been a critical setback to their practical applications. This study aims to fabricate solution-processed CIGSSe solar cells with high PCEs by incorporation of Ag into the precursor layer of the CIGSSe absorber films. The results showed that Ag doping promoted grain growth by accelerating Se uptake, irrespective of the location within the CIGSSe film. Nevertheless, uniform Ag doping formed crevices that lowered the PCE of the cells, while centrally localizing the doped Ag prevented the formation of crevices, resulting in high PCEs up to 15.3%. Our results demonstrate that carefully doping Ag into a selected area of the precursor layer of the CIGSSe films can realize solution-processed chalcopyrite solar cells with high PCE.

Long-term Oncologic Outcome and Its Relevant Factors in Anal Cancer in Korea: A Nationwide Data Analysis.

PURPOSE: Anal cancer is a rare disease in Korea, and thus survival analyses are limited by small sample sizes. This study used the Korea Central Cancer Registry (KCCR) for a survival analysis and for assessing characteristics of anal cancer in a large sample of Koreans. METHODS: From the KCCR, data on 3,615 patients who were diagnosed and treated for anal cancer from 1993 to 2015 were retrieved. Clinicopathologic variables including age, sex, histological type, and Surveillance Epidemiology and End Results (SEER) stage were reviewed, and a survival analysis was performed according to these variables. RESULTS: The 5-year relative survival rate improved from 39.7% in 1993-1995 to 66.5% in 2011-2015. Squamous cell carcinoma was the most common and showed the highest survival rate. Males and older patients (≥40 years and ≥70 years) showed poor prognoses. CONCLUSION: The survival rate for anal cancer in Korea has improved steadily over time. The characteristics related to survival were the histological type, sex, and age. These statistics will be fundamental for future Korean anal cancer research.

Costs of viral hepatitis B in the Republic of Korea, 2002-2015.

The Republic of Korea has a high prevalence of hepatitis B virus (HBV) infection, and the policies concerning costly antiviral medication have been revised recently. However, in the past 10 years, no related research on costs has been conducted. The objective of this study was to estimate the economic burden of viral hepatitis B and determine the trend of changes in its costs between 2002 and 2015. Claims data from the National Health Insurance Service were used. To identify viral hepatitis B cases, the ICD-10th code B16, B17.0, B18.0 and B18.1 were used based on a primary diagnosis. This study was conducted from a societal perspective regarding both direct and indirect costs. Annual costs were adjusted for inflation by calculations based on the 2015 costs. The number of patients with viral hepatitis B increased from 213 758 in 2002 to 342 672 in 2015. The total socio-economic costs increased from 127.1 million USD in 2002 to 459.1 million USD in 2015, mainly due to the increase in pharmaceutical costs, which accounted for the largest proportion of total costs since 2009-220.5 million USD in 2015, which was ~15 times higher than that in 2002. The healthcare costs for viral hepatitis B accounted for 0.13% of the national health expenditure in 2002, increasing to 0.31% in 2015. The economic burden of viral hepatitis B has increased in the Republic of Korea. It is therefore essential to reduce the healthcare costs of HBV infection by establishing an effective management policy.

RGB-Colored Cu(In,Ga)(S,Se)2 Thin-Film Solar Cells with Minimal Efficiency Loss Using Narrow-Bandwidth Stopband Nano-Multilayered Filters.

Colorful Cu(In,Ga)(S,Se)2 (CIGSSe) thin-film solar cells were achieved by integrating a narrow-bandwidth stopband filter (NBSF) on a CIGSSe cell. The full range of visible color of NBSF could be realized by depositing one-dimensional nano-multilayers of alternating high-index (Al2O3) and low-index (SiO2) films while controlling the thickness of each layer and the number of stacked layers. Particularly, high-purity red, green, and blue (RGB) colors were generated on black CIGSSe cells with minimal harvest efficiency drop, showing power conversion efficiency (PCE) losses for the red and green CIGSSe cells of 4.2 and 1.2%, respectively, with no reduction in the PCE of the blue CIGSSe cell. The minimal drop in the harvest efficiency was attributed to the antireflection effect of the NBSF and the low overlap between the reflectance spectrum of NBSFs with a narrow stopband and the absorption spectrum of CIGSSe. The esthetic value could be further enhanced through the color variation of the RGB NBSF with viewing angle, so-called pearl-like colors. The synergetic effect of minimal efficiency loss, full color realization, and the pearl-like color change of the newly developed NBSFs can make CIGSSe cells applicable to building-integrated photovoltaics.

Incidence and Overall Survival of Biliary Tract Cancers in South Korea from 2006 to 2015: Using the National Health Information Database.

Background/Aims: There have been no nationwide studies to investigate the trends in incidence and 5-year survival rates of intra- and extrahepatic bile duct cancers and gallbladder cancer. Therefore, our study aimed to describe the incidence and 5-year survival rates of biliary tract cancers by subsites in South Korea. Methods: A total of 86,134 patients with biliary tract cancers were selected from the National Health Information Database. Age-standardized incidence rates and annual percentage changes were calculated. Lifetable methods and log-rank tests were used to determine the differences in survival rates. Cox-proportional hazard models were used to estimate the hazard ratio of the patients with biliary tract cancers. Results: The incidence rate of intrahepatic bile duct cancer decreased by 1.3% annually from 8.8 per 100,000 in 2006 to 7.8 per 100,000 in 2015. Extrahepatic bile duct cancer also showed a decreasing trend by 2.2% per year from 8.7 per 100,000 in 2006 to 6.7 per 100,000 in 2015. Gallbladder cancer showed the greatest decline, with an annual percentage change of 2.8% from 6.3 per 100,000 to 5.2 per 100,000 during the same period. The 5-year survival rates were 30.0% in gallbladder cancer, 27.8% in extrahepatic bile duct cancer, and 15.9% in intrahepatic bile duct cancer. Conclusions: The overall incidence rates of intrahepatic and extrahepatic bile duct cancer and gallbladder cancer decreased from 2006 to 2015. Among biliary tract cancers, intrahepatic bile duct cancers exhibited the highest incidence rate and the worst survival rate.

A highly efficient Cu(In,Ga)(S,Se)2 photocathode without a hetero-materials overlayer for solar-hydrogen production.

Surface modification of a Cu(In,Ga)(S,Se)2 (CIGSSe) absorber layer is commonly required to obtain high performance CIGSSe photocathodes. However, surface modifications can cause disadvantages such as optical loss, low stability, the use of toxic substances and an increase in complexity. In this work, we demonstrate that a double-graded bandgap structure (top-high, middle-low and bottom-high bandgaps) can achieve high performance in bare CIGSSe photocathodes without any surface modifications via a hetero-materials overlayer that have been fabricated in a cost-effective solution process. We used two kinds of CIGSSe film produced by different precursor solutions consisting of different solvents and binder materials, and both revealed a double-graded bandgap structure composed of an S-rich top layer, Ga- and S-poor middle layer and S- and Ga-rich bottom layer. The bare CIGSSe photocathode without surface modification exhibited a high photoelectrochemical activity of ~6 mA·cm-2 at 0 V vs. RHE and ~22 mA·cm-2 at -0.27 V vs. RHE, depending on the solution properties used in the CIGSSe film preparation. The incorporation of a Pt catalyst was found to further increase their PEC activity to ~26 mA·cm-2 at -0.16 V vs. RHE.

Cationic Surfactant-Induced Formation of Uniform Gold Nanoparticle Clusters with High Efficiency of Photothermal Conversion under Near-Infrared Irradiation.

A novel and simple method for the fabrication of gold nanoparticle (AuNP) clusters was introduced for use as an efficient near-infrared (NIR) photothermal agent. Cationic surfactants were employed to assemble AuNPs into clusters, during which polyvinylpyrrolidone (PVP) was used to stabilize the AuNP clusters. Through this manner, AuNP clusters with a uniform shape and a narrow size distribution (55.4 ± 5.0 nm by electron microscope) were successfully obtained. A mechanism for the formation of AuNP clusters was studied and proposed. Electrostatic interactions between AuNPs and cationic surfactants, hydrophobic interactions between hydrocarbon chains of cationic surfactants, and repulsive steric interactions of PVP were found to play an important role with regard to the formation mechanism. Photothermal effect in the NIR range of the AuNP clusters was demonstrated; results presented a highly efficient photothermal conversion (with a maximum η of 65%) of the AuNP clusters. The clusters could be easily coated by a silica layer, enabling their biocompatibility and colloidal stability in physiological fluids. The easy-to-fabricate AuNP clusters showed high potential of use as an NIR photothermal agent for cancer therapy.

Investigation of Surface Sulfurization in CuIn1-x Gax S2-y Sey Thin Films by Using Kelvin Probe Force Microscopy.

CuIn1-x Gax S2-y Sey (CIGSSe) thin films have attracted a great deal of attention as promising absorbing materials for solar cell applications, owing to their favorable optical properties (e.g. a direct band gap and high absorption coefficients) and stable structure. Many studies have sought to improve the efficiency of solar cells using these films, and it has been found that surface modification through post-heat treatment can lead to surface passivation of surface defects and a subsequent increase in efficiency. The surface properties of solution-processed CIGSSe films are considered to be particularly important in this respect, owing to the fact that they are more prone to defects. In this work, CIGSSe thin films with differing S/Se ratios at their surface were synthesized by using a precursor solution and post-sulfurization heat treatment. These CIGSSe thin films were investigated with current-voltage and Kelvin probe force microscope (KPFM) analyses. Surface photovoltage (SPV), which is the difference in the work function in the dark and under illumination, was measured by using KPFM, which can examine the screening and the modification of surface charge through carrier trapping. As the concentration of S increases on the CIGSSe film surface, higher work functions and more positive SPV values were observed. Based on these measurements, we inferred the band-bending behavior of CIGSSe absorber films and proposed reasons for the improvement in solar cell performance.

Protective effects of Fructus sophorae extract on collagen-induced arthritis in BALB/c mice.

Styphnolobium japonicum (L.) is utilized in Korean medicine for the treatment of various inflammatory diseases. The aim of the present study was to explore the effects of Fructus sophorae extract (FSE) isolated from the dried ripe fruit of S. japonicum (L.) on the development of type II collagen-induced arthritis (CIA) in BALB/c mice. The CIA mice were orally administered FSE or saline daily for 2 weeks. The incidence and severity of disease and the inflammatory response in the serum and the joint tissues were assessed. Macroscopic and histological investigation indicated that FSE protected against CIA development. FSE was associated with a significant reduction in the levels of total immunoglobulin G2a and proinflammatory cytokines and mediators in the serum. In addition, FSE suppressed the gene expression levels of proinflammatory cytokines and mediators, the mediator of osteoclastic bone remodeling, the receptor activator of nuclear factor κ-B ligand and matrix metalloproteinases in the joint tissues. The present results suggest that FSE may protect against inflammation and bone damage, and would be a valuable candidate for further investigation as a novel anti-arthritic agent.

Lung Cancer Epidemiology in Korea.

PURPOSE: The current study was undertaken to examine the trends in the lung cancer incidence, mortality, and survival after a diagnosis in Korea. MATERIALS AND METHODS: Lung cancer incidence data according to the histologic type and mortality data were obtained from the Korea Central Cancer Registry and the Statistics Korea, respectively. The age-standardized incidence and mortality rates were calculated, and the Joinpoint model and age-period-cohort analyses were used to describe the trends in the rates. The 5-year relative survival rates of lung cancer were also calculated. RESULTS: Although the number of new lung cancer cases increased between 1999 and 2012, the age-standardized incidence rate decreased by 0.9% per year in men, whereas the incidence in women increased by 1.7% per year over the same time. Until 2010, the most common histologic type in men was squamous cell carcinoma, then adenocarcinoma prevailed thereafter. Since 1999, the most frequent histological type in women was adenocarcinoma. The lung cancer mortality started to decrease in 2002, with a more apparent decline for the younger age groups in both men and women. Overall, the 5-year relative survival rates have improved significantly from 11.2% for men and 14.7% for women among patients diagnosed between 1993 and 1997 to 19.3% for men and 28.2% for women among patients diagnosed between 2008 and 2012, respectively. An improvement in survival rate was observed for all major histology groups. CONCLUSION: The epidemiology of lung cancer in Korea has changed over a short time span, with decreasing mortality and improving survival rates. Further study is warranted to determine the cause of these changes.

Anti-inflammatory potential of saponins derived from cultured wild ginseng roots in lipopolysaccharide-stimulated RAW 264.7 macrophages.

Ginseng, namely the root of Panax ginseng Meyer, is a well-known traditional medicine that has been used in Asian countries for thousands of years. Ginseng saponins have been shown to exert a variety of prominent pharmacological effects in a number of diseases. The aim of the present study was to identify the anti-inflammatory effects of total saponins extracted from cultured wild ginseng roots (TSWG) on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. An elevated production of nitric oxide (NO) was detected in the RAW 264.7 cells in response to stimulation with LPS, as shown by NO detection assay using Griess reagent. However, pre-treatment with TSWG inhibited the production of NO through the suppression of inducible NO synthase gene expression. Furthermore, the LPS-induced gene expression and production of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were significantly reduced by treatment with TSWG, as shown by ELISA, and western blot analysis and RT-PCR, respectively. In the LPS-stimulated RAW 264.7 cells, nuclear factor-κB (NF-κB) was translocated from the cytosol to the nucleus, while pre-treatment with TSWG induced the sequestration of NF-κB in the cytosol through the inhibition of the inhibitor of κB degradation, as shown by immunofluorescence staining. TSWG also contributed to the downregulation of mitogen-activated protein kinases and Akt in the LPS-stimulated RAW 264.7 cells. Additionally, in the TSWG-treated RAW 264.7 cells, we observed the activation of nuclear factor (erythroid-derived 2)-like 2 and an increase in heme oxygenase-1 expression; these effects were associated with the inhibition of the generation of reactive oxygen species. The results from the present study indicate that TSWG exerts anti-inflammatory and antioxidant effects, suggesting that TSWG may be an effective therapeutic agent for inflammatory diseases and prevent cellular damage induced by oxidative stress.

Energy-density enhancement of carbon-nanotube-based supercapacitors with redox couple in organic electrolyte.

We demonstrate for the first time that the incorporation of a redox-active molecule in an organic electrolyte can increase the cell voltage of a supercapacitor. The redox molecule also contributes to increasing the cell capacitance by a faradaic redox reaction, and therefore the energy density of the supercapacitor can be significantly increased. More specifically, the addition of redox-active decamethylferrocene in an organic electrolyte results in an approximately 27-fold increase in the energy density of carbon-nanotube-based supercapacitors. The resulting high energy density (36.8 Wh/kg) stems from the increased cell voltage (1.1 V→2.1 V) and cell capacitance (8.3 F/g→61.3 F/g) resulting from decamethylferrocene addition. We found that the voltage increase is associated with the potential of the redox species relative to the electrochemical stability window of the supporting electrolyte. These results will be useful in identifying new electrolytes for high-energy-density supercapacitors.

Atomic layer deposition of ruthenium on plasma-treated vertically aligned carbon nanotubes for high-performance ultracapacitors.

It is challenging to realize a conformal metal coating by atomic layer deposition (ALD) because of the high surface energy of metals. In this study, ALD of ruthenium (Ru) on vertically aligned carbon nanotubes (CNTs) was carried out. To activate the surface of CNTs that lack surface functional groups essential for ALD, oxygen plasma was applied ex situ before ALD. X-ray photoelectron spectroscopy and Raman spectroscopy confirmed surface activation of CNTs by the plasma pretreatment. Transmission electron microscopy analysis with energy-dispersive x-ray spectroscopy composition mapping showed that ALD Ru grew conformally along CNTs walls. ALD Ru/CNTs were electrochemically oxidized to ruthenium oxide (RuOx) that can be a potentially useful candidate for use in the electrodes of ultracapacitors. Electrode performance of RuOx/CNTs was evaluated using cyclic voltammetry and galvanostatic charge-discharge measurements.

Anti-inflammatory potential of peat moss extracts in lipopolysaccharide-stimulated RAW 264.7 macrophages.

The aim of the present study was to identify the anti-inflammatory and anti-oxidative effects of peat moss aqueous extract (PME) on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. To demonstrate the anti-inflammatory and antioxidant effects of PME, the levels of nitric oxide (NO) and cytokines were measured using Griess reagent and cytokine ELISA kits, respectively. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analysis were conducted to evaluate the expression of genes and proteins. Immunofluorescence was used to measure the expression and translocation of transcription factors. Pre-treatment with PME inhibited the production of prostaglandin E(2) and NO by suppressing the gene expression of cyclooxygenase-2 and inducible NO synthase, respectively. The LPS-stimulated gene expression and the production of tumor necrosis factor-α and interleukin-1ß were significantly reduced by PME. In the LPS-stimulated RAW 264.7 cells, nuclear factor­κB (NF-κB) translocated from the cytosol to the nucleus, while pre-treatment with PME induced the sequestration of NF-κB in the cytosol through the inhibition of IκBα degradation. In the same manner, PME contributed to the inhibition of the activation of mitogen-activated protein kinases. In addition, the PME-treated RAW 264.7 cells facilitated the activation of nuclear factor-like 2 (Nrf2) , and in turn, enhanced heme oxygenase-1 (HO-1) expression. These results indicate that PME exerts anti-inflammatory and antioxidant effects, and suggest that PME may neutralize inflammation and prevent cellular damage by oxidative stress.

Effect of filter designs on hydraulic properties and well efficiency.

To analyze the effect of filter pack arrangement on the hydraulic properties and the well efficiency of a well design, a step drawdown was conducted in a sand-filled tank model. Prior to the test, a single filter pack (SFP), granule only, and two dual filter packs (DFPs), type A (granule-pebble) and type B (pebble-granule), were designed to surround the well screen. The hydraulic properties and well efficiencies related to the filter packs were evaluated using the Hazen's, Eden-Hazel's, Jacob's, and Labadie-Helweg's methods. The results showed that the hydraulic properties and well efficiency of the DFPs were higher than those of a SFP, and the clogging effect and wellhead loss related to the aquifer material were the lowest owing to the grain size and the arrangement of the filter pack. The hydraulic conductivity of the DFPs types A and B was about 1.41 and 6.43 times that of a SFP, respectively. In addition, the well efficiency of the DFPs types A and B was about 1.38 and 1.60 times that of the SFP, respectively. In this study, hydraulic property and well efficiency changes were observed according to the variety of the filter pack used. The results differed from the predictions of previous studies on the grain-size ratio. Proper pack-aquifer ratios and filter pack arrangements are primary factors in the construction of efficient water wells, as is the grain ratio, intrinsic permeability (k), and hydraulic conductivity (K) between the grains of the filter packs and the grains of the aquifer.