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Due to the lack of an effective prophylactic intervention and diagnosis, human liver fluke Clonorchis sinensis continues to afflict a large human population, causing a chronic inflammatory bile duct disease. With an aim to identify target antigens for sensitive serodiagnosis, adenylate kinase 3 of C. sinensis (CsAK3) was successfully expressed in soluble form in Escherichia coli by fusion to an RNA-interacting domain derived from human Lys-tRNA synthetase and purified by Ni2+-affinity chromatography. Anti-CsAK3 serum was raised by immunization of mice, and Western blotting confirmed that CsAK3 was expressed in adult-stage C. sinensis. Histochemical analysis showed that CsAK3 was localized to the subtegumental tissue of C. sinensis and was excreted into the bile duct of the host. When tested against sera from various parasite-infected patients by enzyme-linked immunosorbent assay, the recombinant CsAK3 elicited a specific response to C. sinensis-infected sera. The results suggest that CsAK3, either alone or in combination with other antigens, could be used for improving the clinical diagnosis of clonorchiasis.
This study aimed to investigate the relationship between the unemployment experience and depressive symptoms among mid-aged (ages 45–59) and elderly (ages 60 or above) persons and to examine further the effects of unemployment insurance, industrial accident compensation insurance (IACI) and national pension on the stated relationship. Data were used from the Korean Longitudinal Study of Aging (KLoSA) between 2006 and 2012. A total of 1,536 individuals employed at the 2006 baseline were followed. The association between employment status change during 2006 to 2008, 2008 to 2010 or 2010 to 2012 and depressive symptoms in years 2008, 2010 or 2012 were analysed using a generalised estimating equation model. Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D 10) scale. The results showed that the ‘employed to unemployed’ group had statistically significant increases in depression scores in the mid-aged (β = 0.4884, p = 0.0038) and elderly (β = 0.8275, p ⩽ 0.0001) categories, compared to the ‘employed to employed’ group. Findings were maintained in groups without a social safety net. Contrastingly, the ‘employed to unemployed’ groups with unemployment insurance and IACI did not show statistically significant increases in depression scores. The ‘employed to unemployed’ category of individuals enrolled in the national pension system exhibited a lower increase of depression. Therefore, an enhanced focus on the mental health of unemployed individuals is required, in addition to the provision of a reliable social safety net.
The modified TiO2 nanoparticles were incorporated into the Bulk heterojunction system of P3HT:PCBM to improve the performance of P3HT:PCBM bulk heterojunction organic solar cells. The organically-modified TiO2 nanoparticle compounds were synthesized in aqueous media at room temperature. These TiO2 compounds in various solution concentrations were deposited on the top of the P3HT:PCBM active layer by spin coating. The performance of organic solar cells was carefully investigated in the respect of the scattering and the localized surface plasmon resonance (LSPR) that couple strongly to the incident light. In addition to the device, P3HT:PCBM solar cells with the use of the TiO2 nanoparticles, enhanced Fill Factor (FF) due mainly to improved shunt resistance (Rsh). The TiO2 plays a critical role in improving the interface between P3HT:PCBM active layer and Al electrode.
To compare the characteristics and risk factors for surgical site infections (SSIs) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a nationwide survey, using shared case detection and recording systems.
Retrospective cohort study.
Twenty-six hospitals participating in the Korean Nosocomial Infections Surveillance System (KONIS).
From 2006 to 2009, all patients undergoing THA and TKA in KONIS were enrolled.
SSI occurred in 161 (2.35%) of 6,848 cases (3,422 THAs and 3,426 TKAs). Pooled mean SSI rates were 1.69% and 2.82% for THA and TKA, respectively. Of the cases we examined, 42 (26%) were superficial-incisional SSIs and 119 (74%) were “severe” SSIs; of the latter, 24 (15%) were deep-incisional SSIs and 95 (59%) were organ/space SSIs. In multivariate analysis, a duration of preoperative hospital stay of greater than 3 days was a risk factor for total SSI after both THA and TKA. Diabetes mellitus, revision surgery, prolonged duration of surgery (above the 75th percentile), and the need for surgery due to trauma were independent risk factors for total and severe SSI after THA, while male sex and an operating room without artificial ventilation were independent risk factors for total and severe SSI after TKA. A large volume of surgeries (more than 10 procedures per month) protected against total and severe SSI, but only in patients who underwent TKA.
Risk factors for SSI after arthroplasty differ according to the site of the arthroplasty. Therefore, clinicians should take into account the site of arthroplasty in the analysis of SSI and the development of strategies for reducing SSI.
This study was conducted to verify the relationship between organizational cultural types, social capital and organizational effectiveness in South Korean dental clinics. The findings suggest that consensual culture is the best fit with social capital. Also, high level of organizational identification, trust and cohesiveness increases job satisfaction and lowers turnover intention. If applying the results practically, organizational identification, improvement of welfare system, stress control, and coaching program for personal development are the most optimal solution.
To evaluate the risk factors for surgical site infection (SSI) after gastric surgery in patients in Korea.
A nationwide prospective multicenter study.
Twenty university-affiliated hospitals in Korea.
The Korean Nosocomial Infections Surveillance System (KONIS), a Web-based system, was developed. Patients in 20 Korean hospitals from 2007 to 2009 were prospectively monitored for SSI for up to 30 days after gastric surgery. Demographic data, hospital characteristics, and potential perioperative risk factors were collected and analyzed, using multivariate logistic regression models.
Of the 4,238 case patients monitored, 64.9% (2,752) were male, and mean age (±SD) was 58.8 (±12.3) years. The SSI rates were 2.92, 6.45, and 10.87 per 100 operations for the National Nosocomial Infections Surveillance system risk index categories of 0, 1, and 2 or 3, respectively. The majority (69.4%) of the SSIs observed were organ or space SSIs. The most frequently isolated microorganisms were Staphylococcus aureus and Klebsiella pneumoniae. Male sex (odds ratio [OR], 1.67 [95% confidence interval (CI), 1.09–2.58]), increased operation time (1.20 [1.07–1.34] per 1-hour increase), reoperation (7.27 [3.68–14.38]), combined multiple procedures (1.79 [1.13–2.83]), prophylactic administration of the first antibiotic dose after skin incision (3.00 [1.09–8.23]), and prolonged duration (≥7 days) of surgical antibiotic prophylaxis (SAP; 2.70 [1.26–5.64]) were independently associated with increased risk of SSI.
Male sex, inappropriate SAP, and operation-related variables are independent risk factors for SSI after gastric surgery.
The effects of tannic acid (TA) supplementation (0·02 %, wt/wt) were compared with the effects of clofibrate (CF) supplementation (0·02 %, wt/wt) in apo E-deficient (apo E− / −) mice fed a AIN-76 semi-synthetic diet (normal diet) over 20 weeks. The mice were monitored for the modulation of hepatic mRNA expression and the activities of lipid-regulating enzymes. Both TA and CF supplementation lowered hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) activity and prevented atherosclerotic lesion formation in comparison with the control group. Hepatic carnitine palmitoyl transferase and β-oxidation activities were significantly higher in the TA and CF groups than in the control group. Both CF and TA supplementation resulted in significant decreases in hepatic HMGR mRNA levels in association with its enzyme activity. However, in contrast to CF supplementation, TA supplementation seemed to decrease the accumulation of hepatic lipids in the apo E− / − mice without increasing liver weight. These results suggest that the overall effect of TA is more desirable than CF for the alleviation of hepatic lipogenesis and atherogenesis in apo E− / − mice.
Pt/Sr0.85Bi2.4Ta2O9/TiO2/Si structures were prepared with variation of the Sr0.85Bi2.4Ta2O9 (SBT) film thickness for MFIS-FET applications. After depositing TiO2 film of 10 nm thickness by reactive sputtering on Si(100) substrate as a buffer layer, SBT thin film of 210-400 nm thickness was prepared onto it by metal organic decomposition process. Regardless of the SBT film thickness, the Pt/SBT/TiO2/Si structures exhibited clockwise directional hysteresis, indicating well-defined ferroelectric switching behavior of the SBT films. While the memory window of the Pt/SBT/TiO2/Si MFIS structures increased with increasing the SBT film thickness, the maximum capacitance of the Pt/SBT/TiO2/Si MFIS structures decreased with increasing the SBT film thickness. The Pt/SBT(400 nm)/TiO2(10 nm)/Si structure exhibited a memory window of 1.3 V at ±5 V.
YMnO3 thin films were sputtered on Si (100) substrates under different ambient conditions. After rapid thermal annealing process at 850 °C, the YMnO3 film deposited in Ar ambient had random orientations and the YMnO3 film deposited in Ar+O2 ambient was crystallized with distinct two layers, i.e., c-axis oriented layer in top region and random oriented layer in bottom region. Relations between the microstructure and the electrical properties of Pt/YMnO3/Si capacitor were investigated. Memory window and leakage current depended on the orientation of the YMnO3 thin films and the interfacial microstructure of the YMnO3/Si, respectively
The role of the size of amorphous silicon quantum dots in the Er luminescence at 1.54 μm was investigated. As the dot size was increased, the more Er ions were located near one dot due to its large surface area and more Er ions interacted with other ones. This Er-Er interaction caused a weak photoluminescence intensity despite the increase in the effective excitation cross section. The critical dot size, needed to take advantage of the positive effect on Er luminescence, is considered to be about 2.0 nm, below which a small dot is very effective in the efficient luminescence of Er.
Silicon nanocrystals were in situ grown in a silicon nitride film by plasma enhanced chemical vapor deposition. The size and structure of silicon nanocrystals were confirmed by high-resolution transmission electron microscopy. Depending on the size, the photoluminescence of silicon nanocrystals can be tuned from the near infrared (1.38 eV) to the ultraviolet (3.02 eV). The fitted photoluminescence peak energy as E(eV) = 1.16 + 11.8/d2 is an evidence for the quantum confinement effect in silicon nanocrystals. The results demonstrate that the band gap of silicon nanocrystals embedded in silicon nitride matrix was more effectively controlled for a wide range of luminescent wavelengths.
We report on microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements. The microstructures were examined using optical and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscope (EDS). Two types of alloys were prepared using vacuum arc melting; one is Fe-28Al based alloys (D03 structured) with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys (B2 structured) produced with same manner. For both types of alloys, equiaxed microstructures were observed by the addition of Mo, while dendritic structures were observed by the Zr addition. These microstructural features were more evinced with increasing the content of alloying elements. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys with or without Mo addition superior to Fe-28Al based alloys especially in the high temperature region.
System in package (SiP) is a superb candidate to enhance the area efficiency and performance of electronic packaging. Here, recent work on stacked chip type 3D SiP with vertically interconnected through hole vias are reported. The process includes; formation of 50um-diameter via holes, conformal deposition of SiO2 dielectric layer, deposition of Ta and Cu barrier layers, via filling by Cu electroplating, Cu/Sn bump formation for multi-chip stacking, and finally chip-to-PCB bonding using Sn-3.0Ag-0.5Cu solder and ENIG pad. A prototype 3D SiP stacked up to 10 layers was successfully fabricated.
A high frequency electrical model of the through hole via was proposed and the model parameters were extracted from measured S-parameters. The proposed model was verified by TDR/TDT (time domain reflectometry/time domain transmission) and eye-diagram measurement. Contact resistances of Cu via and bump joint were presented.
Effects of Pt and W2N/W bottom electrodes on dielectric properties of 1000 Å thick BaTiO3 thin film capacitors are studied. The tetragonality of BaTiO3 on W2N/W electrode is better than that of BaTiO3 on Pt electrode and leakage current of W2N/W/BaTiO3/Au capacitor is four orders of magnitude less than that of Pt/BaTiO3/Au capacitor. The excellent properties of W2N/W/BaTiO3/Au capacitor is ascribed to both of the tetragonal structure of WO3 formed at the interface of W/BaTiO3 and the diffusion barrier property of W2N preventing the interfacial reaction among bottom electrodes, BaTiO3, and Si.
Plasma enhanced chemical vapor deposited tungsten nitride (PECVD-W67N33) thin film has been proposed as a diffusion barrier. The resistivity and lattice constant of PECVD-W67N33 are 110-28 μΩ-cm and 4.134 Å, respectively and this film has compressive stress of 2.6 × 1010 dyne/cm2. Thermal stability of PECVD-W67N33 as a diffusion barrier reveals that the interdiffusions between Al or W and Si substrate can be prevented by N interstitial atoms in fcc-W2N grains and grain boundaries.
An amorphized tungsten nitride diffusion barrier is compared with that of polycrystalline tungsten nitride preventing the diffusion of copper into Si during post annealing processes at 600 – 800 °C for 30 min. Experimental evidence such as RBS, TEM, XRD measurements shows that the amorphized tungsten nitride layer perfectly blocks the expeditious diffusion of the Cu film due to the amorphous grain boundaries stuffed with N impurities.
We have fabricated metal/ferroelectric/insulator/semiconductor (MEFIS) capacitors of Pt/SrBi2Ta2O9(SBT)/CeO2/Si and Pt/SBT/Ce-Si-O/Si. The cerium silicate (Ce-Si-O) layer is formed by reaction between CeO2 thin film and SiO2/Si substrate at 1100 °C. The SBT film on the cerium silicate layer is smoother than the SBT/CeO2. The memory window of the SBT/Ce-Si-O increases to 1.4 V at a sweep voltage of ±5 V, whereas the memory window of the SBT/CeO2 is 0.8 V at the same sweep voltage.
The effect of the post plasma treatment on the dielectric properties and reliability of fluorine doped silicon oxide (SiOF) films was studied. Also, the thermal stability of a Cu/WN interconnect system with SiOF intermetal dielectrics was examined by RTA. The surface roughness of SiOF films increased with the increasing plasma treatment power due to ion bombardment effect during the plasma treatment. As the plasma treatment power increased, the dielectric constant increased from 3.16 to 3.43, while the change in the relative dielectric constant of the plasma treated films by the boiling treatment was decreased in magnitude. Furthermore, the chemical properties of the plasma treated SiOF films near the top layer tend to resemble those of thermal oxides by the plasma treatment of sufficient power because of the reduction in the Si-F bonding in the films. In the case of Cu/WN/SiOF/Si multilayer structure, surface oxidation and densification due to the plasma treatment seemed to play an important role in protecting the interdiffusion between SiOF and metal interconnects.
Perovskite-phase lead zirconate titanate (PZT) thin films were fabricated at 4751C by the electron cyclotron resonance (ECR) plasma enhanced DC magnetron multi-target reactive sputtering method on Pt/Ti/SiO2/Si and Pt/SiO2/Si substrates. Stoichiometric perovskite PZT films were readily obtained on Pt/Ti/SiO2/Si substrates because Ti atoms which were out-diffused to the Pt surface facilitated Pb incorporation by forming lead titanate at the early stage of deposition process. Activation of oxygen by ECR plasma facilitated the oxidation reaction and Pb incorporation into the film. Thus perovskite-phase PZT can be obtained on the Pt/SiO2/Si substrate.
Pt/SrBi2Ta2O9(SBT)/CeO2/Si (MFIS) structures were investigated for observing the change of electrical properties and morphology of interface of Pt/SBT after post-annealing of Pt top electrodes. The morphology of Pt/SBT interface became smooth and Bi oxide was formed at the bottom of Pt top electrode after post-annealing Pt top electrode. In order to describe the origin of these changes, Bi-oxide/Pt/SiO2/Si structure was investigated with annealing temperatures about the reaction between Bi oxide and Pt. We can describe that the smooth interface of Pt/SBT and the consumption of metallic Bi, which the reason why electrical properties were drastically improved, is induced by the melting of Pt-Bi alloys and formation of Bi-oxide after post-annealing Pt top electrode.