• International Journal of Highway Engineering
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• v.16 no.2
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• pp.19-24
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• 2014

PURPOSES : The study objective was to evaluate rheology and physical properties of SBS-modified warm-mix asphalt (WMA) binders in comparison with hot-mix asphalt (HMA) binders. METHODS : Four different SBS polymers were used to prepare polymer-modified asphalt (PMA) binders, and three different warm-mix additives (WAD) were used to prepare a total of 12 WMA PMA binders. The kinematic viscosity was measured at 115, $135^{\circ}C$. The PG was determined using DSR and BBR. The pass/fail (P/F) temperatures for high and low PG grading were evaluated for HMA PMA and WMA PMA binders. RESULTS : PG 76-22 binders could be prepared by modifying the base binder (PG 64-22) using 4.5 wt% of SBS. The kinematic viscosity (KV) of SBS PMA was increased by 3 times higher than that of base asphalt. The SBS PMA with WAD showed 10% lower KV than that of the normal SBS PMA at $115^{\circ}C$ The high P/F temperatures showed almost no difference between HMA PMA and WMA PMA binders. The high P/F temperature showed very high correlations with KV ($R^2$ > 0.97). The result of SBS modification caused increase of low P/F temperature by $2.7^{\circ}C$ on average. CONCLUSIONS : Since the PMA with WAD showed 10% lower KV than normal (HMA) PMA at $115^{\circ}C$, reducing PMA mixture temperature down to a WMA level was possible in this study. The higher KV binders showed the higher P/F temperature. There was almost no change in high P/F temperature due to the use of WAD. The SBS PMA, showing an increased low P/F temperature, might show somewhat poorer performance at low-temperature, even though the lower PG grade was staying at the same level, i.e., $-22^{\circ}C$.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.349-359
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• 1997

Background : The signal pathways and their precise roles for acute respiratory distress syndrome caused by endotoxin (ETX) has not been established. Since there has been several in vitro experiments suggesting that activation of protein kinase C (PKC) pathway may be responsible for endotoxin-induced inflammatory reaction, we performed in vivo experiments in the rats with the hypothesis that PKC-inhibition can effectively prevent endotoxin-induced acute lung injury. Methods : We studied the role of PKC in ETX-induced ALI using PKC inhibitor (staurosporine, STP) in the rat Specific pathogen free male Sprague-Dawley weighted from 165 to 270g were used for the study. Animals were divided into the normal control (NC)-, vehicle control (VC)-, ETX-, PMA (phorbolmyristateacetate)-, STP+PMA-, and STP+ETX-group. PMA (50mg/kg) or ETX (7mg/kg) was instilled through polyethylen catheter after aseptic tracheostomy with and without STP (0.2mg/kg)-pretreatment STP was injected via tail vein 30min before intratracheal injection (IT) of PMA or ETX. Bronchoalveolar lavage (BAL) was done 3-or 6-hrs after IT of PMA or ETX respectively, to measure protein concentration, total and differential cell counts. Results : The results were as follows. The protein concentrations in BALF in the PMA- and ETX-group were very higher than that of VC-group (p<0.001). When animals were pretreated with STP, the %reduction of the protein concentration in BALF was $64.8{\pm}8.5$ and $30.4{\pm}2.5%$ in the STP+PMA- and STP+ETX-group, respectively (p = 0.028). There was no difference in the total cell counts between the PMA-and VC-group (p = 0.26). However the ETX-group showed markedly increased total cell counts as compared to the VC- (p = 0.003) and PMA-group (p = 0.0027), respectively. The total cell counts in BALF were not changed after pretreatment with STP compared to the PMA- (p = 0.22) and ETX-group (p = 0.46). The percentage of PMN, but not alveolar macrophage, was significantly elevated in the PMA-, and ETX-group. Especially in the ETX-group, the percentage of PMN was 17 times higher than that of PMA (p < 0.001). The differential cell counts was not different between the PMA and STP+PMA On the contrary the STP+ETX-group showed decreased percentage of PMN (p = 0.016). There was no significant relationship between the protein concentration and the total or differential cell counts in each group. Conclusion : Pretreatment with PKC-inhibitor (staurosporine) partially but significantly inhibited ETX-induced ALI.

• Bulletin of the Korean Chemical Society
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• v.7 no.2
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• pp.137-142
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• 1986

The luminescence spectra of $Ru(bpy)_3^{2+}$ in poly(methacrylic acid) (PMA) solutions varied sensitively with pH. At pH < 5.5, the emission intensity increased with pH up to 4 times, while it decreased with pH beyond the pH. The enhanced emission intensity was accompanied by blue-shift of the emission maxima as much as 15 nm. The enhancement of emission intensity was attributed to the restricted rotational mobility of ligand of the cation bound to densely coiled PMA molecules at pH < 5.5. The sharp decrease in emission intensity with increasing pH near pH 5.6 was accounted for conformational transition of the polymer to more extended structure, which was also revealed in viscosity measurement. The enhancement of emission intensity became higher as NaCl concentration of the solution increased. The binding constant of $Ru(bpy)_3^{2+}$ with two carboxylate groups of PMA was calculated as $2{\times}10^5\;M^{-1}$ in 0.1 M NaCl at pH 5.2. The pH dependence of luminescence quenching rate of $Ru(bpy)_3^{2+}$ by $Cu^{++}$ also showed maximum near pH 5, and the rate was more than $10^3$ times higher than that in water, whereas the maximum enhancement of quenching rate (about 20 times) in poly(acrylic acid) (PAA) solution occurred at pH 4.5. On the other hand, the pH dependence for neutral water soluble nitrobenzene (NB) exhibited opposite trend to that of $Cu^{++}$. The quenching constant vs pH curve for $MV^{++}$ was composite of those for $Cu^{++}$ and NB. The anomalous high quenching rate for $Cu^{++}$ in PMA solution at pH < 5.5 was attributed to the binding of $Ru(bpy)_3^{2+}$ and $Cu^{++}$ to the same region of PMA, when it conforms densely coiled structure in the pH range. The observation of mininium quenching rate for NB near pH 5.5 indicated that the $Ru(bpy)_3^{2+}$ bound to the densely coiled PMA is not accessible by NB, which is in bulk water phase. The composite nature of the pH dependence of quenching rate for $MV^{++}$ in PMA solution was attributed to the smaller binding affinity of the cation to PMA, compared to that of $Cu^{++}$. The sharp, cooperative conformational transition with pH observed in PMA was not revealed in PAA. But, the pH dependence of quenching rates in this polymer reflected increased charge density and, thus, binding of cations to the polymer, and expansion of the polymer chain with pH.

• Journal of Life Science
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• v.26 no.2
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• pp.174-180
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• 2016

Dicumarol is a coumarin derivative isolated from sweet clover (Melilotus alba), and has anti-coagulant activity with the inhibitory activity of NAD(P)H quinone oxidoreductase1 (NQO1). NQO1 catalyzes the two-electron reduction of quinones to hydroquinones. Dicumarol competes with NAD(P)H for binding to NQO1, resulting in the inhibition of NQO1 enzymatic activity. The expression of matrix metalloproteinases (MMPs) has been implicated in the invasion and metastasis of cancer cells. The expression of MMPs is regulated by cytokines and signal transduction pathways, including those activated by phorbol myristate acetate (PMA). However, the effects of dicumarol on metalloproteinase (MMP)-9 expression and activity are not investigated here. This study investigated whether dicumarol inhibits MMP-9 expression and activity in PMA-treated human renal carcinoma Caki cells. Dicumarol markedly inhibited the PMA-induced MMP-9 mRNA expression and MMP-9 activity. NF-κB and AP1 promoter activity, which is important in MMP-9 expression, also decreased in dicumarol-treated cells. Furthermore, dicumarol markedly suppressed the ability of PMA-mediated migration in Caki cells. When the relevance of NQO1 in the dicumarol-mediated inhibitory effect on PMA-induced MMP9 activity was elucidated, knock-down of NQO1 with siRNA was found to have no effect on PMA-induced MMP9 activity, suggesting that the stimulating effect of dicumarol on PMA-induced MMP9 activity is independent of NQO1 activity. Taken together, the present studies suggested that dicumarol may inhibit PMA-induced migration via down-regulation of MMP-9 expression and activity.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.403-409
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• 2010

Saccharomyces cerevisiae Hsp30 is a plasma membrane heat shock protein that is induced by various environmental stress conditions. However, the functional role of Hsp30 during diverse environmental stressors is not presently known. To gain insight into its function during thermal stress, we have constructed and characterized a ${\Delta}hsp30$ strain during heat stress. $BY4741{\Delta}hsp30$ cells were found to be more sensitive compared with BY4741 cells, when exposed to a lethal heat stress at $50^{\circ}C$. When budding yeast is exposed to either heat shock or weak organic acid, it inhibits Pma1p activity. In this study, we measured the levels of Pma1p in mutant and Wt cells both during optimal temperature and heat shock temperature. We observed that $BY4741{\Delta}hsp30$ cells showed constitutive reduction of Pma1p. To gain further insights into the role of Hsp30 during heat stress, we compared the total protein profile by 2D gel electrophoresis followed by identification of differentially expressed spots by LC-MS. We observed that contrary to that expected from thermal-stress-induced changes in gene expression, the ${\Delta}hsp30$ mutant maintained elevated levels of Pdc1p, Trx1p, and Nbp35p and reduced levels of Atp2p and Sod1p during heat shock. In conclusion, Hsp30 is necessary during lethal heat stress, for the maintenance of Pma1p and a set of thermal stress response functions.

• Textile Coloration and Finishing
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• v.17 no.3 s.82
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• pp.16-25
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• 2005

In this research, we investigated hydrolysis of the ester crosslinking on cotton fabric treated with polymer of maleic acid(PMA), citric acid(CA) and combination of polymer of maleic acid and citric acid using Fourier transform infrared spectroscophy. The rate of hydrolysis of the ester crosslinkage increased with pH regardless of the type of polycarboxylic acid used and even after hydrolysis for 256 hour in pH 13_4 solution, the treated fabric retained $10-20\%$ ester crosslinkage. The durability to alkaline hydrolysis of the ester crosslinkage formed by CA was lower than that of by PMA and combination of poly(maleic acid) and citric acid indicating that the ester formed by CA on the cotton fabric is more susceptible to hydrolysis than that formed by PMA and combination of PMA and CA. The total amount of ester and polycarboxylic acid molecules removed from fabric increased with increasing hydrolysis time but the rate of hydrolysis of ester linkage were higher than that of removal of polycarboxylic acid molecule from the fabric. The characteristic of hydrolysis of fabric treated with combination of PMA and CA was related with the mixing ratio of PMA and CA in treating fabric.

• Biomedical Science Letters
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• v.2 no.2
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• pp.175-185
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• 1996

The mitogen-activated protein(MAP) kinase signal transduction pathway represents an important mechanism by which mitogen, such as serum and PMA, regulate cell proliferation and differentiation. Target substrates of the MAP kinase are located within several compartments containing plasma membranes and nucleus. We now report that serum addition induces proliferation of the P388 murine leukemia cell, but PMA does not, while both serum and PMA treatment cause translocation of the MAP kinase, mainly p42$^{mapk}$ isoform, from cytosol into the nucleus, which was monitored by immunoblot analysis using polyclonal anti-ERK1 antibodies. We investigated whether the MAP kinase was capable of phosphorylating c-Jun protein and GST-fusion proteins, the P562$^{kk}$N-terminal peptides (1-77 or 1-123 domain) of the T cell tyrosine kinase, using the partially purified MAP kinase by SP-sephadex C-50, phenyl superose and Mono Q column chromatography. We found that the partially purified MAP kinase was able to phosphorylate c-Jun protein and the GST-fusion protein expressed using E.coli DH5$\alpha$ which is transformed with pGEX-3Xb plasmid vector carrying of p562$^{kk}$N-terminal peptide-encoding DNA. These results imply that tyrosine kinase receptor/Ras/Raf/MAP kinase pathway is a major mechanism for mitogen-induced cell proliferation in P388 murine leukemia cell and that the various MAP kinase isoforms may have their own target substrates located in distinct subcellular compartments.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.249-255
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• 2007

While respiratory burst enhances neutrophil glucose utilization, many neutrophil functions are critically influenced by extracellular matrix interaction and phosphoinositide-3-OH kinase (PI3K) signaling. We thus evaluated the role of RGD integrin occupancy and PI3K inhibition on respiratory burst and [18F]FDG uptake of stimulated neutrophils. Human neutrophils were stimulated by 100 ng/mL phorbol-myristate-acetate (PMA), and respiratory burst was measured by cumulative luminescence with lucigenin. [18F]FDG uptake and total hexokinase activity was measured 20 min after PMA stimulation in the presence or absence of soluble RGD peptides (200 g/mL) and/or the PI3K inhibitor wortmannin (200 nM). PMA induced a 71.70.9 fold increase in neutrophil oxygen intermediate generation. [18F]FDG uptake was increased to $194.6{\pm} 3.7%$ and hexokinase activity to $145.0{\pm}2.0%$ of basal levels (both p<0.0005). RGD peptides attenuated respiratory burst activation to $35.6{\pm}0.2%$ (p<0.005), but did not inhibit stimulated [18F]FDG uptake or hexokinase activity. In contrast, without affecting respiratory burst activation, wortmannin inhibited PMA stimulated [18F]FDG uptake to $66.9{\pm}1.6%$ and hexokinase activity to $81.0{\pm}4.2%$ (both P<0.0005), demonstrating its dependence on PI3K activity. Neither RGD nor wortmannin reversed the other's inhibitory effect on stimulated [18F]FDG uptake and hexokinase activity or respiratory burst, which suggests the involvement of distinct signaling pathways. Neutrophil [18F]FDG uptake is enhanced by PMA through a mechanism that requires PI3K activity but is independent of integrin receptor occupancy or respiratory burst activation.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3570-3576
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• 2013

Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and $N_2$ adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

• Molecules and Cells
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• v.23 no.1
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• pp.94-99
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• 2007

Suppressors of cytokine signaling (SOCS) family members are negative feedback regulators of the Jak/Stat pathway, which is an essential inflammatory signaling pathway. We investigated expression of eight members of the SOCS family in rat astrocytes, using two inflammatory stimulants, PMA and IFN-${\gamma}$. Only a few SOCS genes were induced by both stimulants, and we detected an increase in SOCS5 protein with PMA. PMA activated the Jnk, Erk, p38, and Jak/Stat signal pathways. In addition, it increased the level of activated-Stat3 resulting from tyrosine phosphorylation. A gel-shift assay showed that a protein in nuclear extracts from PMA-treated cells was able to bind to Stat binding elements. These results suggest that activated Stat3 binds to SOCS promoters and leads to their transcriptional induction.