• Title/Summary/Keyword: Pretreatment effect

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Effect of PCC Pretreatment with Pulp Powder on the Paper Properties (목재펄프 분말을 이용한 PCC 전처리가 종이 성질에 미치는 영향)

  • Kwak, Gun Ho;Cho, Byoung-Uk;Lee, Yong-Kyu;Won, Jong Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.1
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    • pp.39-45
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    • 2014
  • Various approaches have been tried to reduce the emission of carbon dioxide in paper industry. One of important approaches is to use PCC manufactured from emission gas as a filler. However, it was recognized that PCC is inferior to other fillers in the paper strength properties of view. Therefore, pretreatment of PCC with pulp powder was tried to mitigate the strength reduction of paper. Pretreatment of PCC with pulp powder improved the bulk(7.4~12.9%) and air permeability(24.8~42.98%), but there is no significant change in opacity. Tensile index, burst index and stiffness were decreased by the use of pretreated PCC with pulp powder. Anionic and cationic PAM were used as a additive for PCC pretreatment in order to improve strength properties. There was no significant change in bulk in all kinds of PAM used in this study. Most strength properties were improved by the pretreatment of PCC with the anionic and cationic PAM and pulp powder, although the opacity and stiffness were more or less decreased.

Pretreatment with Lycopene Attenuates Oxidative Stress-Induced Apoptosis in Human Mesenchymal Stem Cells

  • Kim, Ji Yong;Lee, Jai-Sung;Han, Yong-Seok;Lee, Jun Hee;Bae, Inhyu;Yoon, Yeo Min;Kwon, Sang Mo;Lee, Sang Hun
    • Biomolecules & Therapeutics
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    • v.23 no.6
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    • pp.517-524
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    • 2015
  • Human mesenchymal stem cells (MSCs) have been used in cell-based therapy to promote revascularization after peripheral or myocardial ischemia. High levels of reactive oxygen species (ROS) are involved in the senescence and apoptosis of MSCs, causing defective neovascularization. Here, we examined the effect of the natural antioxidant lycopene on oxidative stress-induced apoptosis in MSCs. Although $H_2O_2$ ($200{\mu}M$) increased intracellular ROS levels in human MSCs, lycopene ($10{\mu}M$) pretreatment suppressed $H_2O_2$-induced ROS generation and increased survival. $H_2O_2$-induced ROS increased the levels of phosphorylated p38 mitogen activated protein kinase (MAPK), Jun-N-terminal kinase (JNK), ataxia telangiectasia mutated (ATM), and p53, which were inhibited by lycopene pretreatment. Furthermore, lycopene pretreatment decreased the expression of cleaved poly (ADP ribose) polymerase-1 (PARP-1) and caspase-3 and increased the expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax), which were induced by $H_2O_2$ treatment. Moreover, lycopene significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the PI3K-Akt pathway. Our findings show that lycopene pretreatment prevents ischemic injury by suppressing apoptosis-associated signal pathway and enhancing anti-oxidant protein, suggesting that lycopene could be developed as a beneficial broad-spectrum agent for the successful MSC transplantation in ischemic diseases.

Effects of Surfactants on Pectinase Treatment of Cotton/Chitosan Blends (면/키토산 혼방섬유의 펙티나제 처리시 계면활성제의 영향)

  • Song, Yu-Sun;Kim, Hye-Rim;Song, Wha-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.12
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    • pp.1965-1970
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    • 2009
  • This study examined the effect of surfactant pretreatment on the pectinase-treated cotton/chitosan blends by weight loss and properties such as water absorbency, dyeability, tensile strength, pilling property, and surface morphology. The weight loss of cotton/chitosan blends was 1.5% by the surfactant pretreatment/pectinase treatment. The water absorbency and dyeability of samples showed a significant improvement by the surfactant pretreatment/pectinase treatment. The tensile strength and pilling property of treated fabrics showed no change. The water absorbency and dyeability of pectinase treated samples improved with the pretreatment of the surfactant without damaging the fibers.

Glucose recovery from different corn stover fractions using dilute acid and alkaline pretreatment techniques

  • Aboagye, D.;Banadda, N.;Kambugu, R.;Seay, J.;Kiggundu, N.;Zziwa, A.;Kabenge, I.
    • Journal of Ecology and Environment
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    • v.41 no.7
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    • pp.191-201
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    • 2017
  • Background: Limited availability of corn stover due to the competing uses (organic manure, animal feed, bio-materials, and bioenergy) presents a major concern for its future in the bio-economy. Furthermore, biomass research has exhibited different results due to the differences in the supply of enzymes and dissimilar analytical methods. The effect of the two leading pretreatment techniques (dilute acid and alkaline) on glucose yield from three corn stover fractions (cob, stalk, and leaf) sourced from a single harvest in Uganda were studied at temperatures 100, 120, 140, and $160^{\circ}C$ over reaction times of 5, 10, 30, and 60 min. Results: From this study, the highest glucose concentrations obtained from the dilute acid (DA) pretreated cobs, stalks, and leaves were 18.4 g/L (66.8% glucose yield), 16.2 g/L (64.1% glucose yield), and 11.0 g/L (49.5% glucose yield), respectively. The optimal pretreatment settings needed to obtain these yields from the DA pretreated samples were at a temperature of $160^{\circ}C$ over an incubation time of 30 min. The highest glucose concentrations obtained from the alkaline (AL) pretreated cobs, stalks, and leaves were 24.7 g/L (81.73% glucose yield), 21.3 g/L (81.23% glucose yield), and 15.0 g/L (51.92% glucose yield), respectively. To be able to achieve these yields, the optimal pretreatment settings for the cobs and stalks were $140^{\circ}C$ and for a retention time of 30 min, while the leaves require optimal conditions of $140^{\circ}C$ and for a retention time of 60 min. Conclusions: The study recommends that the leaves could be left on the field during harvesting since the recovery of glucose from the pretreated cobs and stalks is higher.

Formalin Pretreatment Attenuates Tail-Flick Inhibition Induced by ${\beta}$-Endorphin Administered Intracerebroventricularly or Intrathecally in Mice

  • Han Ki-Jung;Choi Seong-Soo;Shim Eon-Jeong;Seo Young-Jun;Kwon Min-Soo;Lee Jin-Young;Lee Han-Kyu;Suh Hong-Won
    • Archives of Pharmacal Research
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    • v.28 no.2
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    • pp.227-231
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    • 2005
  • We examined the effect of the subcutaneous (s.c.) pretreatment of formalin into both hind paws of mice on the antinociception induced by the intracerebroventricularly (i.c.v.) or intrathecally (i.t.) administration of ${\beta}$-endorphin using the tail-flick test. Pretreatment with formalin ($5\%$) for 5 h had no affect on the i.c.v. administered ${\beta}$-endorphin-induced tail-flick response. However, pretreatment with formalin for 40 h attenuated the tail-flick inhibition induced by i.c.v. administered ${\beta}$-endorphin. This antinociceptive tolerance to i.c.v. ${\beta}$-endorphin continued up to 1 week, but to a lesser extent. Pretreatment with formalin for 5 and 40 h significantly reduced the i.t. ${\beta}$-endorphin-induced inhibition of the tail-flick response, which continued up to 1 week. The s.c. formalin treatment increased the hypothalamic pro-opiomelanocortin (POMC) mRNA level at 2 h, but this returned to the basal level after 40 h. Our results suggest that the increase in the POMC mRNA level in the hypothalamus appears to be involved in the supraspinal or spinal ${\beta}$-endorphin-induced antinociceptive tolerance in formalin-induced inflammatory pain.

Effect of Antibiotics upon the Antibacterial Activity of Platelet Microbicidal Protein against Streptococcus rattus BHT

  • Kim, Jae-Wook;Choe, Son-Jin;Lee, Si-Young
    • International Journal of Oral Biology
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    • v.34 no.1
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    • pp.43-48
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    • 2009
  • Thrombin-induced platelet microbicidal protein (tPMP) is a small cationic peptide that exerts potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus and Streptococcus rattus BHT. Earlier evidence has suggested that tPMP targets and disrupts the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacteria or whether subsequent, presumably intracellular, events are also involved in this process. In this study, we investigated the microbicidal activity of rabbit tPMP toward S. rattus BHT cells in the presence or absence of a pretreatment with antibiotics that differ in their mechanisms of action. The streptocidal effects of tPMP on control cells (no antibiotic pretreatment) were rapid and concentration-dependent. Pretreatment of S. rattus BHT cells with either penicillin or amoxicillin (inhibitors of bacterial cell wall synthesis) significantly enhanced the anti-S. rattus BHT effects of tPMP compared with the effects against the respective control cells over most tPMP concentration ranges tested. On the other hand, pretreatment of S. rattus BHT cells with tetracycline or doxycycline (30S ribosomal subunit inhibitors) significantly decreased the streptocidal effects of tPMP over a wide peptide concentration range. Furthermore, pretreatment with rifampin (an inhibitor of DNA-dependent RNA polymerase) essentially blocked the killing of S. rattus BHT by tPMP at most concentrations compared with the respective control cells. These results suggest that tPMP exerts anti-S. rattus BHT activity through mechanisms involving both the cell membrane and intracellular targets.