• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.55-68
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• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.3
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• pp.129-144
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• 2003

Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin biosynthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) or cAMP-elevating agents stimulate melanogenesis and enhance the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Rhizoma Bletillae on the basal melanogenic activities of B16／F10 mouse melanoma cells, and on the ${\alpha}$-MSH or forskolin-induced melanogenesis. Rhizoma Bletillae alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. Pretreatment of the cells with Rhizoma Bletillae also suppressed the increase of ${\alpha}$-MSH (100 nM) or forskolin (20 ${\mu}M$)-induced melanin content and tyrosinase activity. The decrease in the tyrosinase activity was paralled by a decrease in the abundance of tyrosinase protein and tyrosinase promoter activity. Pretreatment of the cells with Rhizoma Bletillae also inhibited the increase of forskolin(20${\mu}M$) induced the amount of tyrosinase protein and tyrosinase promoter activity. The results of DOPA staining revealed that pretreatment of the cells with Rhizoma Bletillae showed less intensity than B16 melanoma cells stimulated with ${\alpha}$-MSH or forskolin. These results suggest that Rhizoma Bletillae inhibits melanogenesis and abrogates ${\alpha}$-MSH and cAMP-induced melanogenesis in B16 melanoma cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.277.1-277.1
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• 2013

Molecular diagnostics consists of three processes, which are a sample pretreatment, a nucleic acid amplification, and an amplicon detection. Among three components, sample pretreatment is an important process in that it can increase the limit of detection by purifying nucleic acid in biological sample from contaminants that may interfere with the downstream genetic analysis such as nucleic acid amplification and detection. To achieve point-of-care virus detection system, the sample pretreatment process needs to be simple, rapid, and automatic. However, the commercial RNA extraction kits such as Rneasy (Qiagen) or MagnaPure (Roche) kit are highly labor-intensive and time-consuming due to numerous manual steps, and so it is not adequate for the on-site sample preparation. Herein, we have developed a rotary microfluidic system to extract and purify the RNA without necessity of external mechanical syringe pumps to allow flow control using microfluidic technology. We designed three reservoirs for sample, washing buffer, and elution buffer which were connected with different dimensional microfluidic channels. By controlling RPM, we could dispense a RNA sample solution, a washing buffer, and an elution buffer successively, so that the RNA was captured in the sol-gel solid phase, purified, and eluted in the downstream. Such a novel rotary sample preparation system eliminates some complicated hardwares and human intervention providing the opportunity to construct a fully integrated genetic analysis microsystem.

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.133-144
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• 2023

Densification is an effective method for improving the physical and mechanical properties of low-density wood. However, the set-recovery of dimensions was found to be the problem of densified wood due to low fixation during the densification process. Alkali pretreatment before densification is thought to be a modification process to improve the dimensional stability of densified wood. In this research, the wood samples used were boiled in a 1.25 N sodium hydroxide (NaOH) solution at different times, followed by densification for 5 h at 100℃. The alkali pretreatment for 1, 3, and 5 h of boiling increased the dimensional stability of densified woods and anti-swelling efficiency values were 8.52%, 63.24%, and 48.94%, respectively. The boiling of wood in NaOH solution decreased the holocellulose content, as well as lignin to a lesser degree, and a lower crystallinity index was observed. The lower hydroxyl groups and a higher proportion of lignin in treated samples seem to have contributed to the high dimensional stability detected.

• International Journal of Oral Biology
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• v.35 no.3
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• pp.129-135
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• 2010

Recent studies have implicated reactive oxygen species (ROS) as determinants of the pathological pain caused by the activation of peripheral neurons. It has not been elucidated, however, how ROS activate the primary sensory neurons in the pain pathway. In this study, calcium imaging was performed to investigate the effects of NaOCl, a ROS donor, on the intracellular calcium concentration ($[Ca^{2+}]i$) in acutely dissociated dorsal root ganglion (DRG) neurons. DRG was sequentially treated with 0.2 mg/ml of both protease and thermolysin, and single neurons were then obtained by mechanical dissociation. The administration of NaOCl then caused a reversible increase in the $[Ca^{2+}]i$, which was inhibited by pretreatment with phenyl-N-tertbuthylnitrone (PBN) and isoascorbate, both ROS scavengers. The NaOCl-induced $[Ca^{2+}]i$ increase was suppressed both in a calcium free solution and after depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. Additionally, this increase was predominantly blocked by pretreatment with the transient receptor potential (TRP) antagonists, ruthenium red ($50\;{\mu}M$) and capsazepine ($10\;{\mu}M$). Collectively, these results suggest that an increase in the intracellular calcium concentration is produced from both extracellular fluid and the intracellular calcium store, and that TRP might be involved in the sensation of pain induced by ROS.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.37-43
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• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1141-1149
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• 1998

Tencel fabrics were treated with NaOH, mechanically prefibrillated, and hydrolyzed by cellulase. Softner was applied to improve hand of the treated Tencel fabrics after prefibrillation and cellulase treatment. Kawabata's Evaluation System for Fabrics(KES-FB) was used to evaluate effects of NaOH pretreatment, prebifrillation, and cellulase and softner treatments on fabric hand of the treated fabrics. Primary hand values of women's medium thick fabrics such as KOSHI, NUMERI, FUKURAMI, and SOFUTOSA, and total hand values were evaluation parameters. As the treatments of prefibrillation, cellulase, and softner progressed, values in bending and shearing properties decreased and softness and elasticity were imparted to the treated fabrics. Specifically, compressional linearity, compressional energy, and thickness of the treated fabrics increased by prefibrillation, providing bulkiness to the treated fabrics. Values indicating surface properties increased owing to fibrils formed by prefibrillation treatment, but removal of fibrils by cellulase treatment enhanced smoothness. As the fabrics were exposed to various treatments such as NaOH pretreatments, prefibrillation, and cellulase and softner treatments, NUMERI, FUKURAMI, SOFUTOSA, and total hand values increased with the exception of KOSHI, Consequently, the treated fabrics became softer, smoother, and more elastic. Especially, the NaOH pretreatment provided superior SOFUTOSA to Tencel fabrics.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.563-571
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• 2006

Vapor grown carbon fiber (VGCF) nano-materials such as carbon nanotubes and carbon nanofibers were directly grown on the surface of the stainless steel mesh pre-treated by reduction. The reduction of the stainless steel mesh by hydrogen formed small catalytic particles and large particles with bi-modal distribution on the metal surface. When the VGCFs were synthesized on the reduced mesh, carbon nanotubes (CNTs) were dominantly grown from the small catalytic particles without supplying hydrogen gas. However, carbon nanofibers (CNFs) were dominantly grown from the large catalytic particles with hydrogen.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.52-58
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• 2013

The effets of the pretreatments of tropical kapok fibers were evaluated in this study in terms of water sorption capacity and oil sorption capacity. The alkali treatments with NaOH resulted in the reduction of lignin, oil and hemicellulose, which were detected with FT-IR spectrum. The reduction of the lyphophilic components such as fat on kapok fiber by the ozone treatments were also measured with FT-IR spectrum. The oil sorption capacity of kapok fiber was decreased by the alkali treatments and the ozone treatments, while the water sorption capacity was increased. The liquid sorption capacity were greatly affected by the mechanical cutting of kapok fiber which exposed the big lumen of kapok fiber. The hydrophilic property of kapok fiber could be controlled by the pretreatments, which would increase the applicability of kapok fiber for preparation of various functional paper products.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.107-112
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• 2005

Background: Nerve ligation injury may produce mechanical allodynia, but this can be reversed after an intrathecal administration of adenosine analogues. In many animal and human studies, ATP-sensitive potassium channel blockers have been known to reverse the antinociceptive effect of various drugs. This study was performed to evaluate the mechanical antiallodynic effects of spinal R-PIA (Adenosine A1 receptor agonist) and the reversal of these effects due to pretreatment with glibenclamide (ATP-sensitive potassium channel blocker). Thus, the relationship between the antiallodynic effects of R-PIA and ATP-sensitive potassium channel were investigated in a neuropathic model. Methods: Male Sprague Dawley rats were prepared by tightly ligating the left lumbar 5th and 6th spinal nerves and implantation of a chronic lumbar intrathecal catheter for drug administration. The mechanical allodynia was measured by applying von Frey filaments ipsilateral to the lesioned hind paw. And the thresholds for paw withdrawal assessed. In study 1, either R-PIA (0.5, 1 and $2{\mu}g$) or saline were administered intrathecally for the examination of the antiallodynic effect of R-PIA. In study 2, glibenclamide (2, 5, 10 and 20 nM) was administered intrathecally 5 min prior to an R-PIA injection for investigation of the reversal of the antiallodynic effects of R-PIA. Results: The antiallodynic effect of R-PIA was produced in a dose dependent manner. In study 1, the paw withdrawal threshold was significantly increased with $2{\mu}g$ R-PIA (P < 0.05). In study 2, the paw withdrawal threshold with $2{\mu}g$ R-PIA was significantly decreased almost dose dependently by intrathecal pretreatment of 5, 10 and 20 nM glibenclamide (P < 0.05). Conclusions: These results demonstrated that an intrathecal injection of ATP-sensitive potassium channel blockers prior to an intrathecal injection of adenosine A1 receptors agonist had an antagonistic effect on R-PIA induced antiallodynia. The results suggest that the mechanism of mechanical antiallodynia, as induced by an intrathecal injection of R-PIA, may involve the ATP-sensitive potassium channel at both the spinal and supraspinal level in a rat nerve ligation injury model.