• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.409-416
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• 2017

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of $6.92{\pm}0.09$. It has spreadability value of $15.04{\pm}0.98g{\cdot}cm/sec$ and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control $Kwell^{(R)}$, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.123-133
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• 2007

The presence of antibiotics in the wastewater from livestock farm due to its over-application should be concerned because they could change microbial ecology, increase the proliferation of antibiotic resistant pathogens, provoke toxic effect on aquatic species. In addition, these antibiotics can cause negative effect on the performance of biological wastewater treatment due to its antibacterial properties. In this study, our aim is to evaluate the effect of some common used antibiotic in Korea piggery farm such as oxytetracycline (OTC) to nitrification efficiency as well as organic compounds removal rate in biological system for treating piggery wastwater. The experiment was conducted in aeration batch reactor and lab-scale $A_2/O$(Anoxic-Anoxic-Oxic) system. From this study, it would be suggested that the piggery wastewater characterization should be examined in order to assess the fraction of common used antibiotics. The alternative treatment processes for piggery wastewater having high-strength antibiotics might be suggested in the future work.

• Mycobiology
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• v.45 no.1
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• pp.44-47
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• 2017

Ginseng damping-off, caused by the fungal pathogens Rhizoctonia solani and Pythium sp., is a critical disease in ginseng seedling. In a continuing effort to find microorganisms with the potential of acting as a biocontrol agent against Rhizoctonia damping-off, we found that a Streptomyces sp. A501 showed significant antifungal activity against Rhizoctonia solani. In field experiment to test the efficacy of Streptomyces sp. A501 in controlling ginseng damping-off, the incidence of damping-off disease was meaningfully reduced when ginseng seeds were soaked in the culture broth of Streptomyces sp. A501 before sowing. To perform characterization of the antifungal compound, we isolated it from the culture broth of strain A501 through Diaion HP-20 and silica gel column chromatographies and preparative high-performance liquid chromatography. The structure of the antifungal compound was assigned as fungichromin by spectroscopic methods, mainly nuclear magnetic resonance and electrospray ionization-mass analysis.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.573-577
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• 2014

The existing metal getters are invariably covered with thin oxide layers in air and the native oxide layer must be dissolved into the getter materials for activation. However, high temperature is needed for the activation, which leads to unavoidable deleterious effects on the devices. Therefore, to improve the device efficiency and gas-adsorption properties of the device, it is essential to synthesize the getter with a method that does not require a thermal activation temperature. In this study, getter material was synthesized using palladium oxide (PdOx) which can adsorb $H_2$ gas. To enhance the efficiency of the hydrogen and moisture absorption, a porous layer with a large specific area was fabricated by an etching process and used as supporting substrates. It was confirmed that the moisture-absorption performance of the $SiO_2/Si$ was characterized by water vapor volume with relative humidity. The gas-adsorption properties occurred in the absence of the activation process.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.36.2-36.2
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• 2009

Low dielectric materials have been great attention in the semiconductor industry to develop high performance interlayer dielectrics with low k for Cu interconnect technology. In our study, the dielectric properties of SiOC /SiO2 thin film derived from polyphenylcarbosilane were investigated as a potential interlayer dielectrics for Cu interconnect technology. Polyphenylcarbosilane was synthesized from thermal rearrangement of polymethylphenylsilane around $350^{\circ}C{\sim}430^{\circ}C$. Characterization of synthesized polyphenylcarbosilane was performed with 29Si, 13C, 1H NMR, FT-IR, TG, XRD, GPC and GC analysis. From FT-IR data, the band at 1035 cm-1 is very strong and assigned to CH2 bending vibration in Si-CH2-Si group, indicating the formation of the polyphenylcarbosilane. Number average of molecular weight (Mn) of the polyphenylcarbosilane synthesized at $400^{\circ}C$ for 6hwas 2, 500 and is easily soluble in organic solvent. SiOC/SiO2 thin film was fabricated on ton-type silicon wafer by spin coating using 30wt % polyphenylcarbosilane incyclohexane. Curing of the film was performed in the air up to $400^{\circ}C$ for 2h. The thickness of the film is ranged from $1{\mu}m$ to $1.7{\mu}m$. The dielectric constant was determined from the capacitance data obtained from metal/polyphenylcarbosilane/conductive Si MIM capacitors and show a dielectric constant as low as 2.5 without added porosity. The SiOC /SiO2 thin film derived from polyphenylcarbosilane shows promising application as an interlayer dielectrics for Cu interconnect technology.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.9-14
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• 2002

In the present study, we used the microdialysis technique combined with high performance liquid chromatography (HPLC) and electrochemical detection to measure the extracellular levels of norepinephrine (NE) in the posterior hypothalamus in vivo, and to examine the effects of various drugs, affecting central noradrenergic transmission, on the extracellular concentration of NE in the posterior hypothalamus. Microdialysis probes were implanted stereotaxically into the posterior hypothalamus (coordinates: posterior 4.3 mm, lateral 0.5 mm, ventral 8 mm, relative to bregma and the brain surface, respectively) of rats, and dialysate collection began 2 hr after the implantation. The baseline level of monoamines in the dialysates were determined to be: NE $0.17{\pm}0.01,$ 3,4-dihydroxyphenylacetic acid (DOPAC) $0.94{\pm}0.07,$ homovanillic acid (HVA) $0.57{\pm}0.05$ pmol/sample (n=8). When the posterior hypothalamus was perfused with 90 mM potassium, maximum 555% increase of NE output was observed. Concomitantly, this treatment significantly decreased the output of DOPAC and HVA by 35% and 28%, respectively. Local application of imipramine $(50\;{\mu}M)$ enhanced the level of NE in the posterior hypothalamus (maximum 200%) compared to preperfusion control values. But, DOPAC and HVA outputs remained unchanged. Pargyline, an irreversible monoamine oxidase inhibitor, i.p. administered at a dose of 75 mg/kg, increased NE output (maximum 165%), while decreased DOPAC and HVA outputs (maximum 13 and 12%, respectively). These results indicate that NE in dialysate from the rat posterior hypothalamus were neuronal origin, and that manipulations which profoundly affected the levels of extracellular neurotransmitter had also effects on metabolite levels.

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.75-80
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• 2015

Multi-block sulfonated poly(arylene ether sulfone) (SPAES) copolymer was synthesized via nucleophilic aromatic substitution reaction for proton exchange membrane fuel cell application. After synthesizing the hydrophilic and hydrophobic precursor oligomers having different end-groups (F-terminated or OH-terminated), the effect of end group on the molecular weight was investigated. Hydrophilic oligomers with hydroquinone showed better performance as fuel cell membranes. SPAES membranes showed comparable proton conductivity to that of Nafion at $80^{\circ}C$ and above 70% RH. In particular, SPAES 9 with hydroquinone showed higher proton conductivity than SPAES 10 in the whole RH range studied. Increased local concentration of sulfonic acids within hydrophilic block might develop the hydrophilic-hydrophobic phase separation in the block copolymers.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.10
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• pp.1049-1054
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• 2012

Continued advancements in organic materials have led to the development of organic devices that are thin, flexible, and lightweight and that can potentially be used as low-cost energy-conversion devices. While these devices have many advantages, the environmentally induced degradation of the active materials and the low-work-function electrodes remain a valid concern. Hence, many vacuum deposition processes have been applied to develop low-permeation barrier coatings. In this work, we present the results pertaining to the developed thin-film encapsulation. Multilayer encapsulation involves the use of $SiO_x$ or $SiN_x$ with parylene. The effective water vapor transmission rates were investigated using a Ca-corrosion test. The integration of the developed barrier layers was demonstrated by encapsulating pentacene/$C_{60}$ solar cells, and the results are presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.73-76
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• 2010

The issue of inspection and characterization of microstructures has emerged as a major consideration in design, fabrication, and detection of MEMS devices. However, the conventional measurement techniques, including scanning electron microscopy (SEM) imaging, atomic force microscopy (AFM) scanning, and mechanical surface profiler, require often destructive process or may be difficult to measure with a wafer scale. In this paper, we characterize the surface profiles of microstructures using an optical scanner based on a DVD pick-up module. Scanning images of the microstructures are successfully generated using the intensity of reflected light from different depths of the surface profiles, based on the focus error signal (FES) from photodiodes. It is shown that the proposed optical scanner can be used as an alternative measurement system with high performance and low cost, compared to conventional measurement techniques.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.575-580
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• 2015

Pd/C catalysts were prepared by various preparation methods such as ion exchange, impregnation and polyol method and also characterized by nitrogen adsorption-desorption isothermal, XRD, FE-TEM and CO-chemisorption. The activities of these catalysts were tested in the hydrogenation of cyclohexene to cyclohexane. Catalytic activities of Pd/C catalysts were found to be effected by the chosen preparation methods. Pd dispersions of each Pd/C catalysts prepared by ion exchange, impregnation and polyol method were 17.55, 13.82% and 1.35%, respectively, confirmed by CO-chemisorption analysis. These were also in good agreement with the FE-TEM results. The Pd/C catalyst prepared by ion exchange method exhibits good performance with the cyclohexene conversion rate of 71% for 15 min. These results indicate that Pd/C catalyst having higher dispersion and lower particle size is in favor of hydrogenation cyclohexene and also Pd dispersion increases with the increment of catalytic activity.