• Title/Summary/Keyword: weak acid

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Continuous Separation of Lysozyme from Egg White by Ion Exchange Column Chromatography (이온교환 칼럼 크로마토그래피를 이용한 난백에서 Lysozyme의 연속추출)

  • Park, Seong-Joon;Kim, Hyeon-Seok;Kim, Hyean-Wee;Ahn, Tae-Hoe;Park, Ki-Moon;Choi, Chun-Un
    • Korean Journal of Food Science and Technology
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    • v.22 no.6
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    • pp.711-715
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    • 1990
  • Continuous column chromatographic separation of lysozyme from egg white was investigated. A weak acid type cation exchange resin, Duolite C-464, was used because of high lysozyme recovery and ease of column operation in this experiment. The resin was equilibrated at $pH\;7.9{\pm}0.1$ in Na+form. Continuous lysozyme separation was processed by repeating cycles(one cycle : resin equilibration, flow egg white, rinse, lysozyme elution) in automated preparative Liquid Chromatography(LC) system(column size ; i.d. 50 mm, resin bed volumn ; 1020 ml). At comparison of UV levels in rinse end point and elution end point of every cycle, the UV levels of rinse end point are maintained below 30% for 19 cycles and that of elution end point are also maintained below 30% for 17 cycles, stably, but was increased above 50% after 18 cycle. That indicated the eluting ability of lysozyme was reduced conspicuously after 18 cycle in continuous cycling process. The recovery of lysozyme was maintained above 90% from one to 17 cycle, but was decreased to 72% and 65% in 18 cycle and 19 cycle, respectively.

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The Effects of TWEAK, Fn14, and TGF-$\beta1$ on Degeneration of Human Intervertebral Disc

  • Huh, Hoon;Lee, Yong-Jik;Kim, Jung-Hee;Kong, Min-Ho;Song, Kwan-Young;Choi, Gun
    • Journal of Korean Neurosurgical Society
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    • v.47 no.1
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    • pp.30-35
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    • 2010
  • Objective: The purpose of this study is to explain the effect and reciprocal action among tumor necrosis factor (TNF) like weak inducer of apoptosis (TWEAK), fibroblast growth factor-inducible 14 (Fn14), and transforming growth factor-$\beta1$ (TGF-$\beta1$) on degeneration of human intervertebral disc (IVD). Methods: Human intervertebral disc tissues and cells were cultured with Dulbecco's Modified Eagle's Medium/Nutrient F-12 Ham (DMEM/F-12) media in $37^{\circ}C$, 5% $CO_2$ incubator. When IVD tissues were cultured with TWEAK, Fn14 that is an antagonistic receptor for TWEAK and TGF-$\beta1$, the level of sulfated glycosaminoglycan (sGAG) was estimated by dimethyl methyleneblue (DMMB) assay and sex determining region Y (SRY)-box 9 (Sox9) and versican messenger ribonucleic acid (mRNA) levels were estimated by reverse transcriptase polymerase chain reaction (RT-PCR). Results: When human IVD tissue was cultured for nine days, the sGAG content was elevated in proportion to culture duration. The sGAG was decreased significantly by TWEAK 100 ng/mL, however, Fn14 500 ng/mL did not change the sGAG production of IVD tissue. The Fn14 increased versican and Sox9 mRNA levels decreased with TWEAK in IVD tissue TGF-$\beta1$ 20 ng/mL elevated the sGAG concentration 40% more than control. The sGAG amount decreased with TWEAK was increased with Fn14 or TGF-$\beta1$ but the result was insignificant statistically. TGF-$\beta1$ increased the Sox9 mRNA expression to 180% compared to control group in IVD tissue. Sox9 and versican mRNA levels decreased by TWEAK were increased with TGF-$\beta1$ in primary cultured IVD cells, however, Fn14 did not show increasing effect on Sox9 and versican. Conclusion: This study suggests that TWEAK would act a role in intervertebral disc degeneration through decreasing sGAG and the mRNA level of versican and Sox9.

Flotation for Recycling of a Waste Water Filtered from Molybdenite Tailings (몰리브덴 선광광미 응집여과액 재활용을 위한 부유선별 특성)

  • Park, Chul-Hyun;Jeon, Ho-Seok;Han, Oh-Hyung;Kim, Byoung-Gon;Baek, Sang-Ho;Kim, Hak-Sun
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.3
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    • pp.235-242
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    • 2010
  • Froth flotation using the residual water in the end of flotation process has been performed through controlling of pH. IEP (isoelectric point) of molybdenite and quartz in distilled water was below pH 3 and pH 2.7, respectively and the stabilized range was pH 5~10. In case of a suspension in reusing water, zeta potential of molybdenite decreased to below -10 mV or less at over pH 4 due to residual flocculants. As result of pH control, flotation efficiency in the alkaline conditions was deteriorated by flocculation, resulting from expanded polymer chain, ion bridge of the divalent metal cations ($Ca^{2+}$), and hydrophobic interactions between the nonpolar site of polymer/the hydrophobic areas of the particle surfaces. However, the weak acid conditions (pH 5.5~6) improved the efficiency of flotation as hydrogen ions neutralize polymer chains and then weakened its function. In cleans after rougher flotation, the Mo grade of 52.7% and recovery of 90.1% could be successfully obtained under the conditions of 20 g/t kerosene, 50 g/t AF65, 300 g/t $Na_2SiO_3$, pH 5.5 and 2 cleaning times. Hence, we developed a technique which can continuously supply waste water filtered from tailings into the grinding-rougher-cleaning processes.

Morphological Characteristics and Germination Conditions of Seeds in Arabis pendula L. (늘어진장대(Arabis pendula L.) 종자의 형태적 특성 및 발아조건)

  • Shin, So Lim;Lim, Yun Kyung;Kwon, Hyuk Joon;Kim, Yu Ri;Kim, Soo-Young
    • Korean Journal of Plant Resources
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    • v.30 no.1
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    • pp.50-57
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    • 2017
  • This study aimed to investigate the morphological characteristics and optimal germination conditions in seeds of Arabis pendula L., a traditionally edible and medicinal plant. The external seed shape was circular-obovate with narrow wings and dark brown. The seed length and width were 1.25 mm and 1.47 mm, respectively. The seeds were exalbuminous and the embryo was a bent type. Seed germination was the highest (49.7%) at $20^{\circ}C$ under dark conditions among the various temperature and light conditions applied. However, under the dark condition, the seedling was weak, overgrown, and the cotyledons were small and folded. To improve the germination and growth of seedlings, the seeds were pre-treated with $GA_3$ solutions of varying concentrations (0, 200, 500, and 1,000 mg/L). The seed germination and seedling growth were effectively improved by $GA_3$ pre-treatment. The germination rate was the highest (97.3%), mean germination time was the shortest (8.1 days), and a vigorous growth of seedlings was observed upon pre-soaking the seeds in 500 mg/L $GA_3$ solution. In conclusion, the best method for germination was pre-soaking in 500 mg/L $GA_3$ ($4^{\circ}C$, dark, 24 h) and incubating the seeds at $20^{\circ}C$ for 15 days.

Recycling of Cutting Oil from Silicon Waste Sludge of Solar Wafer (태양광용 웨이퍼 실리콘 폐슬러지로부터 절삭유의 재생)

  • Um, Myeong-Heon;Lee, Jong-Jib;Ha, Beom Yong
    • Clean Technology
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    • v.22 no.4
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    • pp.274-280
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    • 2016
  • In this study, it was to develop a chemical method that can recycle the cutting oil which accounts for about 25% of the cost of the process among containing materials of silicon waste sludge generated in the process for producing a solar cell wafer. The 7 types of reagents have been used, including acetone, HCl, NaOH, KOH, $Na_2CO_3$, HF, $CH_2Cl_2$, etc. for this experiment. And It was carried out at a speed of 3000 rpm for 60 minutes centrifugation after performing a reaction with a waste sludge at various concentrations. As a result, the best reagents and conditions for separating the solid such as a silicon powder and a metal powder and liquid cutting oil were identified as 0.3 N NaOH. It is found to be pH 6.05 in a post-processing recycled cutting oil with 0.3 N NaOH after reaction of waste sludge and 0.1 N HCl which is effective to remove metal powder in order to adjust the pH to suit the properties of the weak acid is a commercially available cutting oil and it showed excellent turbidity than when applied to sludge with 0.3 N NaOH alone. The results of FT-IR analysis which can compare the properties of the commercially available cutting oil shows it has a possibility of recycling oil. The cutting oil recovery rate obtained through the experiment was found to be 86.9%.

Expression of Laminin in Rat Tracheal Mucosa after Exposure to Sulfur Dioxide Gas (Sulfur Dioxide 가스 흡입 후 흰쥐 기관 점막에서 Laminin의 발현에 대한 연구)

  • Lee, Hyung-Seok;Yu, Yean-Hee;Cho, Seok-Hyun;Kim, Kyung-Rae;Chung, Ho-Sam
    • Korean Journal of Bronchoesophagology
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    • v.6 no.1
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    • pp.29-37
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    • 2000
  • Background and Objectives : The concentration of sulfur dioxide($SO_2$) gas in the ambient air appears increasing in the industry and urban area day by day. It was known that $SO_2$ is noxious gas. $SO_2$ can be irritating to the eyes, nose, throat, upper respiratory tract and skin. It produces sulfurous acid on contact with water and is extremely irritating to the nasopharynx and respiratory tract. Laminin is a family of extracellular matrix glycoproteins localized in the basement membrane that separates epithelial cells from the underlying stroma. The biological activities of laminin are to promote cell migration, wound healing, growth and differentiation. Meterials and Methods : The histologic changes and the expression of laminin in tracheal mucosa sacrificed at every weeks (to 7 weeks) after continued $SO_2$ exposure of 250ppm for 30 minutes a day were studied in rats. Results : Pathologic tissue was formed at the tracheal mucosa and the underlying tissue by the infiltration of monocytes and epithelium was transformed to the single cell layered epithelium above 5 weeks after exposure. At the 6 weeks after exposure, epithelial cells were partially lost and epithelial cell layer was transformed to be leaf-shaped. Submucosal tissue was transformed to be lymphatic tissue. An intense positive staining for laminin was found in apical cytoplasm and lateral surface of the normal epithelial cells and basement membrane but at the 5 and 6 weeks after exposure, laminin activity was decreased to the moderate activity. At the 7 weeks after exposure, laminin activity was decreased to the weak activity. Conclusion : Our finding suggests that $SO_2$ makes histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin. Longer duration of the exposure of $SO_2$ makes more histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin.

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Inhibitory Effects of Gardenia jasminoides var. radicans Makino on HIV-1 Enzymes and Prediction of Inhibitory Factor by QSAR (꽃치자나무 추출물의 HIV-1 효소 억제 활성과 QSAR에 의한 활성인자 예측)

  • Yu, Young-Beob
    • Korean Journal of Plant Resources
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    • v.27 no.1
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    • pp.22-28
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    • 2014
  • In this study, we conducted the anti-HIV-1 enzymes assay in vitro and its active components were predicted by QSAR in silico for the elucidation of action mechanism on anti-HIV of natural resources. The extracts of Gardenia jasminoides var. radicans Makino were tested for their inhibitory effects on the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the enzyme inhibition assay, the methanol extracts of Gardenia jasminoides var. radicans Makino stem showed a strong activity of 32.5% on the enzyme activity to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease. Moreover the methanol extracts of stem exhibited alpha-glucosidase inhibitory activities of 26.1%. The methanol extracts ($100{\mu}g/ml$) of stem showed a weak activity of 13.4% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. However, all extracts of leaf and stem didn't exhibit the HIV-1-induced cytopathic effects with IC (inhibitory concentration) of $100{\mu}g/ml$ in HIV-1-infected human T-cell line. From these results, it is suggested that Gardenia jasminoides var. radicans Makino extracts may possibly be involved in the inhibition of reverse transcriptase, protease and alpha-glucosidase but can't vitally concerned with the viral replication in vitro.

Cloning of the Bombyx mori short neuropeptide F receptor (BsNPF-R) cDNA (누에 short neuropeptide F receptor (BsNPF-R)의 cDNA cloning)

  • Shin, Hyojung;Kwon, Kisang;Hong, Sun Mee;Kim, Hong Geun;Park, Kwan-Ho;Choi, Ji-Young;Kim, Seung-Whan;Yu, Kweon;Kwon, O-Yu
    • Journal of Life Science
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    • v.26 no.6
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    • pp.721-726
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    • 2016
  • It has already been reported that short neuropeptide F (sNPF) stimulates feeding behaviors in a wide variety of insect species. In the present study, we cloned cDNA, encoding a sNPF receptor homologue from a silkworm, Bombyx mori, named BsNPF-R. The amino acid sequence of BsNPF-R was compared with those of sNPF-R thus far reported, which is shared with humans (36%), mice (34%), zebrafish (35%), and fruit flies (51%), respectively. A BsNPF-R protein’s mass was theoretically estimated to be 42,731 Da and it is a putative plasma membrane-penetrating protein. The mRNA expression of BsNPF-R was tested; the results showed that a strong expression was detected at the midgut, post-silk gland, Malpighian, and testis; however, a weak expression was at the fat body, hemocyte, and ovary. In addition, the synthesized sNPF of a silkworm regulated the BsNPF-R mRNA expression through the cell-based functional analysis.

Germination Induction of Some Weed Seeds Stored Under the Dry and Low Temperature Condition (건조저온저장(乾燥低溫貯藏)한 몇가지 잡초종자(雜草種子)의 발아유기(發芽誘起))

  • Cho, K.Y.;Kim, J.S.;Kim, Y.S.
    • Korean Journal of Weed Science
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    • v.7 no.1
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    • pp.19-28
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    • 1987
  • These experiments were conducted to recognize the germination change in relation to storage period, using 25 kinds of field-collected weed seeds stored under the dry and low temperature ($4{\pm}1^{\circ}C$), and to establish a simple germination induction methods in some kinds of them. No or weak dormancy was observed in Lepidium virginicum, Rumex japonicus, Cirsium japonicum var. ussuriense, Aeschnomene indica and Ludwigia prostrate. The germination of Digltaria sanguinalis, Portulaca oleracea, Amaranthus spp., Echinochloa crux-galli, Polygonum persicaria, Cyperus iria, and Aeschynnmene indica was enhanced by $H_2SO_4$ treatment for 20, 2, 2, 50, 40, 3 or 5 minutes, respectively. Favorable germination in Polygonum persicaria and Echinochloa crus-galli was obtained by soaking in water for 25 days and 50 days, respectively. Moisture treatment for 21 days and 14 days caused the enhancement of germination in Cyperus difformis and Aneilema keisak, respectively. Combination of various treatments in Cyperus iria was most effective when the seeds treated with $H_2SO_4$ for 3 minutes incubated in alternating temp. after soaking in 0.2% $KNO_3$, but their effect on Digitaria sanguinnlis was little.

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EVALUATION OF SODIUM DICHLOROISOCYANURATE AS A ROOT CANAL IRRIGATION SOLUTION;Cl- CONCENTRATION, pH, CYTOTOXICITY AND ANTIMICROBIAL EFFECT IN VITRO (이염화이소시아뉼산나트륨 제재의 근관세척액 사용 가능성 평가;염소이온농도, 세포독성, 항균성 및 pH)

  • Lee, Woo-Cheol;Kang, Bong-Sun;Kim, Cheol-Ho;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.28 no.5
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    • pp.425-430
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    • 2003
  • The purpose of this study was to evaluate the clinical applications of the Sodium Dichloroisocyanurate effervescent tablet as a routine root canal irrigant by performing several in vitro tests such as $Cl^{-}$ content. cytotoxicity. antimicrobial effect as well as its pH level compared to the equivalent concentration of sodium hypochlorite solution. 1. Sodium Dichloroisocyanurate demonstrated lower level of $Cl^{-}$ concentration than each dilution of sodium hypochlorite solution. Both solution has increased level of $Cl^{-}$ as the concentration of each solution increased. There was no significant change of $Cl^{-}$ concentration in sodium hypochlorite as time goes by. However. $Cl^{-}$ concentration in Sodium Dichloroisocyanurate was increased. 2. The antimicrobial effects of both solutions were increased when their concentrations were increased. One day after dilution. antimicrobial effect of Sodium Dichloroisocyanurate was slightly higher than sodium hypochlorite. however. there was no difference in 1 week dilution solution. One month dilution solution of sodium hypochlorite still retain its activity. but antimicrobial effect of Sodium Dichloroisocyanurate was drastically decreased 1 month after dilution. 3. The cytotoxicity of Sodium Dichloroisocyanurate was rather higher than same concentration of sodium hypochlorite solution until 1 week after dilution. Then in 1 month. cytotoxicity of Sodium Dichloroisocyanurate was decreased than that of 1 week dilution solution. especially 4% Sodium Dichloroisocyanurate solution has almost no toxicity. However. 1% and 2% sodium hypochlorite solution has unchanged moderate degree of cytotoxicity after the dilution. Furthermore. 4% sodium hypochlorite solution showed high level of toxicity. 4. The pH level of Sodium Dichloroisocyanurate showed that the solution was weak acid (pH5). On the other hand. sodium hypochlorite was revealed as a strong alkaline solution (pH12). There was no change in pH following the dilution of each solution. As results. Sodium Dichloroisocyanurate solution fully satisfy the basic requirements as a root canal irrigation solution. However. we strongly recommend to use this solution clinically in low concentration and try to apply into the root canal within 1 week after dilution.