A Method for Estimating Time-Dependent Corrosion Depth of Carbon and Weathering Steel Using an Atmospheric Corrosion Monitor Sensor.

In this study, a time-dependent corrosion depth estimation method using atmospheric corrosion monitor (ACM) sensor data to evaluate time-dependent corrosion behaviors is proposed. For the time-dependent corrosion depth estimation of uncoated carbon steel and weathering steel, acceleration corrosion tests were conducted in salt-spray corrosion environments and evaluated with a corrosion damage estimation method using ACM sensing data and corrosion loss data of the tested steel specimens. To estimate the time-dependent corrosion depth using corrosion current by an ACM sensor, the relationship between the mean corrosion depth calculated from the weight loss method and the corrosion current was evaluated. The mean corrosion depth was estimated by calculating the corrosion current and evaluating the relationship between the mean corrosion depth and corrosion current during the expected period. From the test and estimation results, the corrosion current demonstrated a good linear correlation with the mean corrosion depth of carbon steel and weathering. The calculated mean corrosion depth is nearly the same as that of the tested specimen, which can be well used to estimate corrosion rate for the uncoated carbon steel and weathering steel.

Seroprevalences of Specific IgG Antibodies to Measles, Mumps, and Rubella in Korean Infants.

In this study, the seroprevalences of measles, mumps, and rubella antibodies in infants were determined to assess the immunization strategy and control measures for these infectious diseases. Serum samples from infants < 1 year of age and their mothers were collected to measure the concentrations of specific IgG antibodies to measles, mumps, and rubella by enzyme-linked immunosorbent assay. For selected infant serum samples, measles-specific neutralizing antibody levels were determined by using the plaque reduction neutralization test. The sera from 295 of infants and 80 of their mothers were analyzed. No infants had past measles, mumps, or rubella infections. Almost all infants < 2 months of age were positive for measles and rubella IgG antibodies. However, seroprevalence of measles and rubella antibodies decreased with age, and measles IgG and rubella IgG were barely detectable after 4 months of age. The seroprevalence of mumps antibodies was lower than that of measles and rubella antibodies in infants ≤ 4 months old, and mumps IgG was barely detectable after 2 months of age. The seropositivity of measles-specific neutralizing antibody was 63.6% in infants aged 2 months and undetectable in infants ≥ 6 months old. Because the seropositivity rates of measles, mumps, and rubella antibodies were low after the first few months of age in Korean infants, active immunization with vaccines is strongly recommended for infants aged 6-11 months when measles is epidemic. Timely administration of the first dose of measles-mumps-rubella vaccine at 12 months of age should be encouraged in non-epidemic situations.

Reappraisal of the Immunogenicity and Safety of Three Hepatitis A Vaccines in Adolescents.

Although the overall incidence of hepatitis A in Korea has been decreasing, adolescents remain highly vulnerable to its outbreaks. This study was conducted to compare the immunogenicity and safety of three hepatitis A vaccines in Korean adolescents. Healthy anti-hepatitis A virus seronegative subjects aged 13 to 19 yr were randomized in three equal groups to receive two doses of Avaxim™, Epaxal®, or Havrix®, 6 to 12 months apart. Seroconversion rates one month after the first dose were 98%, 95%, and 93% for Avaxim™, Epaxal®, and Havrix®, respectively. Seroconversion rates reached 100% for all vaccine groups one month after the second dose. Anti-HAV geometric mean concentrations (GMCs) were 7,207.7 mIU/mL (95% CI, 6023.1-8684.7), 1,750.5 mIU/mL (95% CI, 1362.9-2248.3), and 1,953.5 mIU/mL (95% CI, 1459.4-2614.7) after two doses of Avaxim™, Epaxal®, and Havrix® respectively. Avaxim™ was significantly more immunogenic than Epaxal® and Havrix®, whereas there were no significant differences in antibody responses between Epaxal® and Havrix®. Local and systemic solicited adverse events (AEs) were mostly of mild-to-moderate intensity and resolved within 5 days. No serious AEs were reported. In conclusion, all three vaccines are highly immunogenic and well-tolerated in Korean adolescents. (Clinical Trial Registry NCT00483470).

Evaluation of Chemical Interactions between Small Molecules in the Gas Phase Using Chemical Force Microscopy.

Chemical force microscopy analyzes the interactions between various chemical/biochemical moieties in situ. In this work we examined force-distance curves and lateral force to measure the interaction between modified AFM tips and differently functionalized molecular monolayers. Especially for the measurements in gas phase, we investigated the effect of humidity on the analysis of force-distance curves and the images in lateral force mode. Flat chemical patterns composed of different functional groups were made through micro-contact printing and lateral force mode provided more resolved analysis of the chemical patterns. From the images of 1-octadecanethiol/11-mercapto-1-undecanoic acid patterns, the amine group functionalized tip brought out higher contrast of the patterns than an intact silicon nitride tip owing to the additional chemical interaction between carboxyl and amine groups. For more complex chemical interactions, relative chemical affinities toward specific peptides were assessed on the pattern of 1-octadecanethiol/phenyl-terminated alkanethiol. The lateral image of chemical force microscopy reflected specific preference of a peptide to phenyl group as well as the hydrophobic interaction.

Synthesis and in vitro screening of phenylbipyridinylpyrazole derivatives as potential antiproliferative agents.

A series of phenylbipyridinylpyrazoles was synthesized through the reaction of 2-(4-(2-chloropyridin-4-yl)-3-(3-methoxy-5-methylphenyl)-1H-pyrazol-1-yl)acetonitrile (4) with different 6-substituted pyridine-3-ylboronic acids. The final compounds 5a-j were screened at 10 µM against over 60 tumor cell lines at the U.S. National Cancer Institute (NCI). In light of the NCI results, compounds 5c and 5h showed a broad spectrum of activity against NCI cell lines with mean growth of 53% and 58%, respectively. Compound 5e behaved differently as it showed high degree of selectivity and potency by inhibiting 96% of growth of leukemia SR cell line at 10 µM. Standard COMPARE analyses were performed at the GI50 level and the results exhibit high correlation in the form of pairwise correlation coefficient (PCC) of more than 0.6 between three of the current compounds and three standard known anticancer agents. Compound 5e demonstrated high correlation levels with merbarone (NSC S336628) with a PCC value of 0.631. Compound 5h showed a considerably high PCC value of 0.626 with dichloroallyl lawsone, while compound 5i, showed PCC values of 0.601 and 0.604 with both dichloroallyl lawsone and N,N-dibenzyldaunomycin (NSC S268242), respectively. These three standard agents have anticancer activity via two major mechanism of actions, inhibition of topoisomerase II and inhibition of biosynthesis of pyrimidine nucleotides, therefore, compounds 5a-j are promising therapeutic agents for targeting different human malignancies. Prediction of drug-likeness and toxicity of these newly synthesized derivatives were also considered.

Plasma modification of poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole) low bandgap polymer and its application in solar cells.

For the first time, we here propose a green methodology to modify a low bandgap polymer for highly efficient solar cells using atmospheric pressure plasma jet or soft plasma operating on different feeding gases (air, Ar and N2). The physical properties of the modified polymer were investigated using conductivity measurements, UV-visible spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammograms, atomic force microscopy, cathodoluminescence and confocal Raman spectroscopy. Further, we examined the variation of the work function of the polymer before and after plasma treatment using a γ-focused ion beam. Additionally, photovoltaic cells based on the plasma-modified polymer having ITO/PEDOT:PSS/PHVTT (with or without plasma modification):PC71BM/LiF/Al configuration were fabricated and then characterized. We found that the power conversion efficiency (PCE) of the plasma-modified polymer increased dramatically as compared to the control polymer (without plasma treatment). PCE of the control polymer was found to be 4.11%, while after air, Ar and N2 gas plasma treatment the polymer showed PCEs of 4.85%, 4.87% and 5.14% respectively. Thus, plasma treatment not only alters the surface properties, but also modifies the bulk properties (changes in HOMO and LUMO bandgap level). Hence, this work provides new dimensions to explore more about plasma and polymer chemistry.

Solar-Powered AEM Electrolyzer via PGM-Free (Oxy)hydroxide Anode with Solar to Hydrogen Conversion Efficiency of 12.44.

Water electrolyzers powered by renewable energy are emerging as clean and sustainable technology for producing hydrogen without carbon emissions. Specifically, anion exchange membrane (AEM) electrolyzers utilizing non-platinum group metal (non-PGM) catalysts have garnered attention as a cost-effective method for hydrogen production, especially when integrated with solar cells. Nonetheless, the progress of such integrated systems is hindered by inadequate water electrolysis efficiency, primarily caused by poor oxygen evolution reaction (OER) electrodes. To address this issue, a NiFeCo─OOH has developed as an OER electrocatalyst and successfully demonstrated its efficacy in an AEM electrolyzer, which is powered by renewable electricity and integrated with a silicon solar cell.

Euscaphic acid isolated from roots of Rosa rugosa inhibits LPS-induced inflammatory responses via TLR4-mediated NF-κB inactivation in RAW 264.7 macrophages.

As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we have evaluated the anti-inflammatory effects of euscaphic acid (19α-hydroxyursane-type triterpenoids, EA) isolated from roots of Rosa rugosa and its underlying molecular mechanisms in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. EA concentration-dependently reduced the production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) induced by LPS in RAW 264.7 macgophages. Consistent with these data, expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and iNOS, COX-2, TNF-α, and IL-1ß mRNA were inhibited by EA in a concentration-dependent manner. In addition, EA attenuated LPS-induced DNA binding and transcriptional activity of nuclear factor-kappa B (NF-κB), which was accompanied by a parallel reduction of degradation and phosphorylation of inhibitory kappa Bα (IκBα) and consequently by decreased nuclear translocation of p65 subunit of NF-κB. Pretreatment with EA significantly inhibited the LPS-induced phosphorylation of IκB kinase ß (IKKß), p38, and JNK, whereas the phosphorylation of ERK1/2 was unaffected. Furthermore, EA interfered with the LPS-induced clustering of TNF receptor-associated factor 6 (TRAF6) with interleukin receptor associated kinase 1 (IRAK1) and transforming growth factor-ß-activated kinase 1 (TAK1). Taken together, these results suggest that EA inhibits LPS-induced inflammatory responses by interference with the clustering of TRAF6 with IRAK1 and TAK1, resulting in blocking the activation of IKK and MAPKs signal transduction to downregulate NF-κB activations.

Synthesis and anticancer activity of di(3-thienyl)methanol and di(3-thienyl)methane.

Di(3-thienyl)methanol (2) and di(3-thienyl)methane (3) have been synthesized and screened against the T98G (brain cancer) cell line. Treatment induced cell death (MTT and macro-colony assay), growth inhibition, cytogenetic damage (micronuclei formation), were studied as cellular response parameters. Treatment with the compounds enhanced growth inhibition and cell death in a concentration dependent manner in both T98G and HEK (normal) cell lines. At higher concentrations (>20 µg/mL) the cytotoxic effects of the compounds were highly significant. The effect on clonogenic capacity and micronuclei formation observed after treatment of cells. Amongst the compounds, compound 2 exhibited potent activity against T98G brain cancer cells. Despite potent in vitro activity, both compounds exhibited less cytotoxicity against normal human HEK cells at all effective concentrations.

Neuromodulators control the polarity of spike-timing-dependent synaptic plasticity.

Near coincidental pre- and postsynaptic action potentials induce associative long-term potentiation (LTP) or long-term depression (LTD), depending on the order of their timing. Here, we show that in visual cortex the rules of this spike-timing-dependent plasticity are not rigid, but shaped by neuromodulator receptors coupled to adenylyl cyclase (AC) and phospholipase C (PLC) signaling cascades. Activation of the AC and PLC cascades results in phosphorylation of postsynaptic glutamate receptors at sites that serve as specific "tags" for LTP and LTD. As a consequence, the outcome (i.e., whether LTP or LTD) of a given pattern of pre- and postsynaptic firing depends not only on the order of the timing, but also on the relative activation of neuromodulator receptors coupled to AC and PLC. These findings indicate that cholinergic and adrenergic neuromodulation associated with the behavioral state of the animal can control the gating and the polarity of cortical plasticity.

Characteristics of wasteform composing of phosphate and silicate to immobilize radioactive waste salts.

In the radioactive waste management, metal chloride wastes from a pyrochemical process is one of problematic wastes not directly applicable to a conventional solidification process. Different from a use of minerals or a specific phosphate glass for immobilizing radioactive waste salts, our research group applied an inorganic composite, SAP (SiO(2)-Al(2)O(3)-P(2)O(5)), to stabilize them by dechlorination. From this method, a unique wasteform composing of phosphate and silicate could be fabricated. This study described the characteristic of the wasteform on the morphology, chemical durability, and some physical properties. The wasteform has a unique "domain-matrix" structure which would be attributed to the incompatibility between silicate and phosphate glass. At higher amounts of chemical binder, "P-rich phase encapsulated by Si-rich phase" was a dominant morphology, but it was changed to be Si-rich phase encapsulated by P-rich phase at a lower amount of binder. The domain and subdomain size in the wasteform was about 0.5-2 µm and hundreds of nm, respectively. The chemical durability of wasteform was confirmed by various leaching test methods (PCT-A, ISO dynamic leaching test, and MCC-1). From the leaching tests, it was found that the P-rich phase had ten times lower leach-resistance than the Si-rich phase. The leach rates of Cs and Sr in the wasteform were about 10(-3)g/m(2)· day, and the leached fractions of them were about 0.04% and 0.06% at 357 days, respectively. Using this method, we could stabilize and solidify the waste salt to form a monolithic wasteform with good leach-resistance. Also, the decrease of waste volume by the dechlorination approach would be beneficial in the final disposal cost, compared with the present immobilization methods for waste salt.

Effect of the nanosized TiO2 particles in Pd/C catalysts as cathode materials in direct methanol fuel cells.

Pd-TiO2/C catalysts were prepared by impregnating titanium dioxide (TiO2) on carbon-supported Pd (Pd/C) for use as the catalyst for the oxygen reduction reaction (ORR) in direct methanol fuel cells (DMFCs). Transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were carried to confirm the distribution, morphology and structure of Pd and TiO2 on the carbon support. In fuel cell test, we confirmed that the addition of TiO2 nanoparticles make the improved catalytic activity of oxygen reduction. The electrochemical characterization of the Pd-TiO2/C catalyst for the ORR was carried out by cyclic voltammetry (CV) in the voltage window of 0.04 V to 1.2 V with scan rate of 25 mV/s. With the increase in the crystallite size of TiO2, the peak potential for OH(ads) desorption on the surface of Pd particle shifted to higher potential. This implies that TiO2 might affect the adsorption and desorption of oxygen molecules on Pd catalyst. The performance of Pd-TiO2/C as a cathode material was found to be similar to or better performance than that of Pt/C.

High-sensitivity C-reactive protein can predict major adverse cardiovascular events in Korean patients with type 2 diabetes.

Inflammation is thought to play a role in the pathogenesis of major adverse cardiovascular events (MACE). It has been suggested that the measurement of markers of inflammation may aid in predicting the risk of such events. Here, the relationship between high-sensitivity C-reactive protein (hs-CRP) levels and MACE in Korean patients with type 2 diabetes is assessed. A retrospective cohort study was conducted as a follow-up among 1,558 patients with type 2 diabetes and without cardiovascular diseases over a mean period of 55.5 months. A Cox proportional-hazards model was used to determine whether increased hs-CRP levels are useful as a predictor for future MACE. The hazard ratio of MACE was 1.77 (95% CI; 1.16-2.71) in subjects who had the highest hs-CRP levels (> 0.21 mg/dL) compared to subjects who had the lowest hs-CRP levels (< 0.08 mg/dL), after adjusting for age, regular physical activity, current smoking, and duration of diabetes. The present results indicate that high hs-CRP levels can act as a predictor for the MACE occurrence in Korean patients with type 2 diabetes.

Performance of PtPd electrocatalysts in direct methanol fuel cell.

PtPd nanoparticles on carbon black were prepared to investigate the role of Pd in the anode and cathode of a direct methanol fuel cell (DMFC). The PtPd catalysts in the anode showed a significantly lower performance than the PtRu catalyst. However, the cell performances of these catalysts in the cathode were comparable to that of the Pt catalyst. From cyclic voltammetry, it was observed that the Pd with the Pt catalyst lowered the peak potential and increased the coulombic charge for oxide reduction on the surface of the catalyst. Also, the Pd catalyst without Pt showed relatively high activity for oxygen reduction reaction.

Residual Compressive Strength of Short Tubular Steel Columns with Artificially Fabricated Local Corrosion Damage.

Corrosion is considered as one of the main factors in the structural performance deterioration of steel members. In this study, experimental and numerical methods were used to assess the reduction in compressive strength of short tubular steel columns with artificially fabricated local corrosion damage. The corrosion damage was varied with different depths, heights, circumferences, and locations along the column. A parametric numerical study was performed to establish a correlation between the residual compressive strength and the severity of corrosion damage. The results showed that as the corrosion depth, height and circumference increased, the compressive strength decreased linearly. As for the corrosion height, the residual compressive strength became constant after decreasing linearly when the corrosion height was greater than the half-wavelength of buckling of the short columns. An equation is presented to evaluate the residual compressive strength of short columns with local corrosion wherein the volume of the corrosion damage was used as a reduction factor in calculating the compressive strength. The percentage error using the presented equation was found to be within 11.4%.

Circularly polarized unidirectional lasing from a cholesteric liquid crystal layer on a 1-D photonic crystal substrate.

We present the results of a study of highly circularly polarized unidirectional lasing emission from an organic lasing device that consisted of a dye-doped cholesteric liquid crystal (CLC) layer on a 1-dimensional (1-D) photonic crystal (PC) reflecting mirror substrate. Unidirectional lasing was demonstrated successfully for this device structure at the wavelength of the high-energy band edge of the CLC layer. It was also shown that circularly polarized lasing emission was produced from the lasing device at a low lasing threshold of 2.5 mJ/pulse. The handedness of lasing light corresponds to the handedness of the used CLC layer with a high ratio of intensity between right- and left-handed circularly polarized lasing light over of up to 3.7. These results show that the CLC / 1-D PC device enables unidirectional lasing with highly circularly polarized laser emission..

Evaluation of Subconjunctival Remnant Particles after High-frequency Radio-wave Electrosurgery for Conjunctivochalasis.

PURPOSE: To investigate the clinical manifestations and properties of remnant particles in the subconjunctival space after high-frequency radio-wave electrosurgery for conjunctivochalasis. METHODS: We performed a retrospective, observational case series with in vitro experimental imaging in nine eyes from eight patients who presented with small dark-gray lesions during follow-up after high-frequency radio-wave electrosurgery for conjunctivochalasis. General examination including slit-lamp examination and visual acuity testing was performed preoperatively and postoperatively. During follow-up, we evaluated remnant particles and any other complications including granuloma or conjunctival injection with slit-lamp photography and anterior optical coherence tomography. Coagulation tips were investigated with scanning electron microscope and energy dispersive X-ray spectroscopy to analyze the insulating electrode and assess changes to tips after repeated use. RESULTS: None of the patients included in this study experienced any change in visual acuity or major complications postoperatively. Small dark-gray lesions (0.3 to 0.5 mm in size) were observed in the inferior bulbar sub-conjunctival space in the location where high-frequency radio-wave electrosurgery had been performed. Cirrus high-definition optical coherence tomography images revealed focal hyper-reflection with a posterior shadow, suggesting foreign particles. Scanning electron microscopy and energy dispersive X-ray spectroscopy imaging analysis revealed peaks of carbon and fluorine complexes, consistent with the polytetrafluoroethylene coating on the electrode. CONCLUSIONS: There were no instances of inflammatory reaction, particle migration, or major complications due to particles. Physicians should be aware of the possibility of remnant polytetrafluoroethylene particles in subconjunctival tissue when using insulated coagulation tips subjected to repeat sterilization.

Associations Among Pregnancy, Parturition, and Open-angle Glaucoma: Korea National Health and Nutrition Examination Survey 2010 to 2011.

PURPOSE: The purpose of this study was to investigate the association between factors associated with parturition and open-angle glaucoma (OAG) in Korean females. METHODS: A population-based, cross-sectional survey was performed from the Korean National Health and Nutrition Examination Survey from 2010 to 2011 and enrolled postmenopausal female participants (n=1798). We obtained information on demographics, comorbidities, and health-related behaviors and performed comprehensive ophthalmic examinations. Multivariate regression analysis was used to assess the correlation between pregnancy and delivery and the prevalence of OAG in all enrolled subjects. RESULTS: The prevalence of OAG among study participants was 6.42%. There was a significant difference in the number of deliveries and age at first delivery between the OAG group and the nonglaucoma group. In multiple linear regression models adjusted for age, hypertension, and intraocular pressure only pregnancy 1 was associated with higher risk of OAG compared with pregnancy 2 (P=0.023). Subjects who had 3 or 4 deliveries were at higher risk of OAG compared with subjects with 2 deliveries (P=0.027). An age at first delivery of 16 to 20 years or 21 to 23 years was associated with increased OAG risk compared with the reference group (P<0.05). CONCLUSIONS: A history of three or more deliveries and an age at first delivery younger than 23 years were associated with increased risk of OAG. These results suggest that changes or events during the period from pregnancy to delivery affect the development of glaucoma.

Synthesis and characterization of Pt-Pd catalysts for methanol oxidation and oxygen reduction.

Pt-Pd nanoparticles supported on carbon black were prepared and characterized as electrocatalysts for methanol oxidation and oxygen reduction in an acidic solution. The Pt and Pd nanoparticles were impregnated spontaneously on the carbon black through a simple reducing process. X-ray diffraction, transmission electron microscopy, and electrochemical measurement were carried out to characterize the crystal structure, particle size, and catalytic activities of the Pt-Pd catalysts. The results showed that the Pt-Pd catalysts had higher catalytic activities for methanol oxidation reaction than pure Pt catalysts. The catalytic activity of the Pt-Pd catalysts for oxygen reduction reactions in the presence of methanol was higher than that of pure Pt and Pd. These results indicate that the Pt-Pd catalysts are suitable as electrocatalysts of both the anode and the cathode in direct methanol fuel cells.

Vacuum distillation of a mixture of LiCl-KCl eutectic salts and RE oxidative precipitates and a dechlorination and oxidation of RE oxychlorides.

In this study, a vacuum distillation of a mixture of LiCl-KCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiCl-KCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710-759.5Torr of a reduced pressure at a fixed heating rate of 4 degrees C/min and the LiCl-KCl eutectic salt was completely separated from the mixture. The required time for the salt distillation and the starting temperature for the salt vaporization were lowered with a reduction in the pressure. Dechlorination and oxidation of the rare-earth oxychlorides was completed at a temperature below 1300 degrees C and this was dependent on the partial pressure of O2. The rare-earth oxychlorides (NdOCl/PrOCl) were transformed to oxides (Nd2O3/PrO2) during the dechlorination and oxidation process. These results will be utilized to design a concept for a process for recycling the waste salt from an electrorefining process.