• Title/Summary/Keyword: Adhesion control

Search Result 656, Processing Time 0.03 seconds

Optimum Synthesis Conditions of Coating Slurry for Metallic Structured De-NOx Catalyst by Coating Process on Ship Exhaust Gas (선박 배연탈질용 금속 구조체 기반 촉매 제조를 위한 코팅슬러리 최적화)

  • Jeong, Haeyoung;Kim, Taeyong;Im, Eunmi;Lim, Dong-Ha
    • Clean Technology
    • /
    • v.24 no.2
    • /
    • pp.127-134
    • /
    • 2018
  • To reduce the environmental pollution by $NO_x$ from ship engine, International maritime organization (IMO) announced Tier III regulation, which is the emmision regulation of ship's exhaust gas in Emission control area (ECA). Selective catalytic reduction (SCR) process is the most commercial $De-NO_x$ system in order to meet the requirement of Tier III regulation. In generally, commercial ceramic honeycomb SCR catalyst has been installed in SCR reactor inside marine vessel engine. However, the ceramic honeycomb SCR catalyst has some serious issues such as low strength and easy destroution at high velocity of exhaust gas from the marine engine. For these reasons, we design to metallic structured catalyst in order to compensate the defects of the ceramic honeycomb catalyst for applying marine SCR system. Especially, metallic structured catalyst has many advantages such as robustness, compactness, lightness, and high thermal conductivity etc. In this study, in order to support catalyst on metal substrate, coating slurry is prepared by changing binder. we successfully fabricate the metallic structured catalyst with strong adhesion by coating, drying, and calcination process. And we carry out the SCR performance and durability such as sonication and dropping test for the prepared samples. The MFC01 shows above 95% of $NO_x$ conversion and much more robust and more stable compared to the commercial honeycomb catalyst. Based on the evaluation of characterization and performance test, we confirm that the proposed metallic structured catalyst in this study has high efficient and durability. Therefore, we suggest that the metallic structured catalyst may be a good alternative as a new type of SCR catalyst for marine SCR system.

A Comparison of Minilaparotomy and Laparoscopic Sterilization (Minilaparotomy 불임술(不妊術)과 복강경불임술(腹腔鏡不妊術)에 관(關)한 비교연구(比較硏究))

  • Bai, Byoung-Choo
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.4 no.1
    • /
    • pp.17-25
    • /
    • 1977
  • Anderson(1937), Power and Barnes(1941) reported a study concerning a method of tubal sterilization in association with peritoneoscopy or laparoscopy in which they cauterized the tubes. There appears to have been a hiatus of interest in sterilization (cold or hot) associated with laparoscopy until reintroduction by Palmer(1963), Frangenheim(1964) and Steptoe(1967). On the other hand, for interval female sterilization, however, minilaparotomy is relatively new. By Saunder and Munsick(1972), John Lyle(1974), Frank Stubb(1974), Vitoon(1973) and B.C. Bai(1975), their own technique for interval female sterilization requires 2.0 to 2.5cm, incision at the margin of the mons pubis. In Korea, female sterilization by means of minilaparotomy firstly reported by B.C. Bai using Bai's uterine elevator, of his own device, early in 1975. Recently inteval female sterilization by laparoscopy and minilaparotomy are widely accepted throughout the world especially in Asian countries. Minilaparotomy is carried out from 1974, laparoscopic sterilization from 1976, and in this study each of 250 cases of those were analysed and discussed for the comparison at Seoul Red Cross Hospital. (1) In the age distribution, numerous clients were in their age of $31{\sim}35$ in laparoscopy as well as minilaparotomy. Average 33.7 years in L and 33.2 years in M. (M=minilaparotomy, L=laparoscopic sterilization) (2) As regarding living children, women having 3 children represented the greatest number, 113 cases out of 250 in M group and 102 cases out of 250 in L group. Average No. of child are 2.9 in Land 3.1 in M. (3) Concidering the operation day in the menstrml cycle, the greatest number of cases, those who underwent tubal sterilization during the days of $26{\sim}$, next during the $6{\sim}10$ days of the cycle in both group. (4) Concidering the operation time, 188 cases by laparoscopy were performed in $6{\sim}10$ minutes, 33 cases within 5 minutes and 24 cases in $11{\sim}15$ minutes. Maximum 50 minutes, minimum 4 minutes and average 8.3 minutes. The majority of cases (154 cases) by minilaparotomy required $6{\sim}10$ minutes and 67 cases $11{\sim}15$ minutes, 6 cases within 5 minutes. Maximum 30 minutes, minimum 4 minutes and average 10.4, minutes. In both groups, most of the reasons for the extra length were surgical difficulties such as thick abdominal wall, pelvic adhesion, less cooperation of patients in early period of this study. (5) Hospital stay after operation in L group required $3{\sim}4$ hours in 125 cases, $2{\sim}3$ hours in 41 cases, $4{\sim}5$ hours in 32 cases out of 250. Maximum 8 hours, minimum 1 hour and average 3.8 hours. In M group hospital stay required $6{\sim}7$ hours in 100 cases, over 7 hours in 85 cases, $5{\sim}6$ hours in 46 cases and so on. Maximum 14 hours, minimum 2 hours and average 6.5 hours. (6) The time between operation and gas passing in the majority cases of both groups, were $12{\sim}36$ hours. A veragetime 20.3 hours in L and 27.2 in M. (7) Laparoscopic sterilization coincident with induced abortion were carried out in 27 cases, laparoscopy with minilaparotomy to control for mesosalpingeal hemorrhage in 1 case. Minilaparotomy coincident with induced abortion were performed in 65 cases, D and C whit polypectomy, menstrual regulatian, and remaval of IUD in 1 case respectively. (8) In L group, 1 case of mesosalpingeal hemorrhage, 1 case of abdominal wall infection were complicated during operation. In M group, 1 case of uterine perfaration, 1 case of abdominal wall infection, 1 case of hemorrhage from omentum and 1 case of bloody vaginal discharge were complicated. No intensive medical treatment was required for those minor complications in both groups. (9) No failure has been recognized and these two sterilization techniques might be the simple, safe and the most effective method for permanent contraception at present time. There is no significant clinical defference between L and M group in this study.

  • PDF

The Ability of Anti-tumor Necrosis Factor Alpha(TNF-${\alpha}$) Antibodies Produced in Sheep Colostrums

  • Yun, Sung-Seob
    • 한국유가공학회:학술대회논문집
    • /
    • 2007.09a
    • /
    • pp.49-58
    • /
    • 2007
  • Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

  • PDF

The micro-tensile bond strength of two-step self-etch adhesive to ground enamel with and without prior acid-etching (산부식 전처리에 따른 2단계 자가부식 접착제의 연마 법랑질에 대한 미세인장결합강도)

  • Kim, You-Lee;Kim, Jee-Hwan;Shim, June-Sung;Kim, Kwang-Mahn;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.46 no.2
    • /
    • pp.148-156
    • /
    • 2008
  • Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.

Activation of NF-${\kappa}B$ in Lung Cancer Cell Lines in Basal and TNF-${\alpha}$ Stimulated States (폐암 세포에서 기저 상태와 TNF-${\alpha}$ 자극 시 NF-${\kappa}B$의 활성화)

  • HwangBo, Bin;Lee, Seung-Hee;Lee, Choon-Taek;Yoo, Chul-Gyu;Han, Sung-Koo;Shim, Young-Soo;Kim, Young-Whan
    • Tuberculosis and Respiratory Diseases
    • /
    • v.52 no.5
    • /
    • pp.485-496
    • /
    • 2002
  • Background : The NF-${\kappa}B$ transcription factors control various biological processes including the immune response, acute phase reaction and cell cycle regulation. NF-${\kappa}B$ complexes are retained in the cytoplasm in the basal state and various stimuli cause a translocation of the NF-${\kappa}B$ complexes into the nucleus where they bind to the ${\kappa}B$ elements and regulate the transcription of the target genes. Recent reports also suggest that NF-${\kappa}B$ proteins are involved in oncogenesis, tumor growth and metastasis. High expression of NF-${\kappa}B$ expression was reported in many cancer cell lines and tissues. The constitutive activation of NF-${\kappa}B$ was also reported in several cancer cell lines supporting its role in cancer development and survival. The anti-apoptotic action of NF-${\kappa}B$ is important for cancer survival. NF-${\kappa}B$ also controls the expression of several proteins that are important for cellular adhesion (ICAM-1, VCAM-1) suggesting a role in cancer metastasis. In lung cancer, high expression levels of the NF-${\kappa}B$ subunit p50 and c-Rel were reported. In fact, high expression does not mean a high activity, and the activation pattern of NF-${\kappa}B$ in lung cancer has not been reported. Materials and Methods : In this study, the NF-${\kappa}B$ nuclear binding activity in the basal and TNF-${\alpha}$ stimulated states were exmined in various lung cancer cell lines and compared with the normal bronchial epithelial cell line. Twelve lung cancer cell lines including the non-small cell and small cell lung cancer cell lines (A549, NCI-H358, NCI-H441, NCI-H552, NCI-H2009, NCI-H460, NCI-H1229, NCI-H1703, NCI-H157, NCI-H187, NCI-H417, NCI-H526) and BEAS-2B bronchial epithelial cell line were used. To evaluate the NF-${\kappa}B$ expression and DNA binding activity, western blot analysis and an electrophoretic mobility shift assay with the nuclear protein extracts. Results : The basal expressions of the p65 and p50 subunits were observed in the BEAS-2B cell line and all lung cancer cell lines except for NCI-H358 and NCI-H460. The expression levels of p65 and p50 were increased 30 minutes after stimulation with TNF-${\alpha}$ in BEAS-2B and in 10 lung cancer cell lines. In the NCI-H358 and NCI-H460 cell lines, p65 expression was not observed in the basal and stimulated states and the two p50 related protein levels were higher after stimulation with TNF-${\alpha}$ These new proteins were smaller than p50 and are thought to be variants of p50. In the basal state, NF-${\kappa}B$ was nearly activated in the BEAS-2B and all lung cancer cell lines. The DNA binding activity of the NF-${\kappa}B$ complexes was markedly higher after stimulation with TNF-${\alpha}$ In the BEAS-2B and all lung cancer cell line except for NCI-H358 and NCI-H460, the activated NF-${\kappa}B$ complex was a p65/p50 heterodimer. In the NCI-H358 and NCI-H460 lung cancer cell lines, the NF-${\kappa}B$ complex was variant of a p50/p50 homodimer. Conclusion : The NF-${\kappa}B$ activation pattern in the lung cancer cell lines and the normal bronchial epithelial cell lines was similar except for the activation of a variant of the p50/p50 homodimer in some lung cancer cell linse.

The Effect of Nitric Oxide Donor or Nitric Oxide Synthase Inhibitor on Oxidant Injury to Cultured Rat Lung Microvascular Endothelial Cells (산화질소 공여물과 산화질소 합성효소 길항제가 백서 폐미세혈관 내피세포 산화제 손상에 미치는 영향)

  • Chang, Joon;Michael, John R.;Kim, Se-Kyu;Kim, Sung-Kyu;Lee, Won-Young;Kang, Kyung-Ho;Yoo, Se-Hwa;Chae, Yang-Seok
    • Tuberculosis and Respiratory Diseases
    • /
    • v.45 no.6
    • /
    • pp.1265-1276
    • /
    • 1998
  • Background : Nitric oxide(NO) is an endogenously produced free radical that plays an important role in regulating vascular tone, inhibition of platelet aggregation and white blood cell adhesion to endothelial cells, and host defense against infection. The highly reactive nature of NO with oxygen radicals suggests that it may either promote or reduce oxidant-induced cell injury in several biological pathways. Oxidant injury and interactions between pulmonary vascular endothelium and leukocytes are important in the pathogenesis of acute lung injury, including acute respiratory distress syndrome(ARDS). In ARDS, therapeutic administration of NO is a clinical condition providing exogenous NO in oxidant-induced endothelial injury. The role of exogenous NO from NO donor or the suppression of endogenous NO production was evaluated in oxidant-induced endothelial injury. Method : The oxidant injury in cultured rat lung microvascular endothelial cells(RLMVC) was induced by hydrogen peroxide generated from glucose oxidase(GO). Cell injury was evaluated by $^{51}$chromium($^{51}Cr$) release technique. NO donor, such as S-nitroso-N-acetylpenicillamine(SNAP) or sodium nitroprusside(SNP), was added to the endothelial cells as a source of exogenous NO. Endogenous production of NO was suppressed with N-monomethyl-L-arginine(L-NMMA) which is an NO synthase inhibitor. L-NMMA was also used in increased endogenous NO production induced by combined stimulation with interferon-$\gamma$(INF-$\gamma$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and lipopolysaccharide(LPS). NO generation from NO donor or from the endothelial cells was evaluated by measuring nitrite concentration. Result : $^{51}Cr$ release was $8.7{\pm}0.5%$ in GO 5 mU/ml, $14.4{\pm}2.9%$ in GO 10 mU/ml, $32.3{\pm}2.9%$ in GO 15 mU/ml, $55.5{\pm}0.3%$ in GO 20 mU/ml and $67.8{\pm}0.9%$ in GO 30 mU/ml ; it was significantly increased in GO 15 mU/ml or higher concentrations when compared with $9.6{\pm}0.7%$ in control(p < 0.05; n=6). L-NMMA(0.5 mM) did not affect the $^{51}Cr$ release by GO. Nitrite concentration was increased to $3.9{\pm}0.3\;{\mu}M$ in culture media of RLMVC treated with INF-$\gamma$ (500 U/ml), TNF-$\alpha$(150 U/ml) and LPS($1\;{\mu}g/ml$) for 24 hours ; it was significantly suppressed by the addition of L-NMMA. The presence of L-NMMA did not affect $^{51}Cr$ release induced by GO in RLMVC pretreated with INF-$\gamma$, TNF-$\alpha$ and LPS. The increase of $^{51}Cr$ release with GO(20 mU/ml) was prevented completely by adding 100 ${\mu}M$ SNAP. But the add of SNP, potassium ferrocyanate or potassium ferricyanate did not protect the oxidant injury. Nitrite accumulation was $23{\pm}1.0\;{\mu}M$ from 100 ${\mu}M$ SNAP at 4 hours in phenol red free Hanks' balanced salt solution. But nitrite was not detectable from SNP upto 1 mM The presence of SNAP did not affect the time dependent generation of hydrogen peroxide by GO in phenol red free Hanks' balanced salt solution. Conclusion : Hydrogen peroxide generated by GO causes oxidant injury in RLMVC. Exogenous NO from NO donor prevents oxidant injury, and the protective effect may be related to the ability to release NO. These results suggest that the exogenous NO may be protective on oxidant injury to the endothelium.

  • PDF