• Title/Summary/Keyword: Flow Resistance

Search Result 1,800, Processing Time 0.028 seconds

Silencing of Suppressor of Cytokine Signaling-3 due to Methylation Results in Phosphorylation of STAT3 in Imatinib Resistant BCR-ABL Positive Chronic Myeloid Leukemia Cells

  • Al-Jamal, Hamid AN;Jusoh, Siti Asmaa Mat;Yong, Ang Cheng;Asan, Jamaruddin Mat;Hassan, Rosline;Johan, Muhammad Farid
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.11
    • /
    • pp.4555-4561
    • /
    • 2014
  • Background: Silencing due to methylation of suppressor of cytokine signaling-3 (SOCS-3), a negative regulator gene for the JAK/STAT signaling pathway has been reported to play important roles in leukemogenesis. Imatinib mesylate is a tyrosine kinase inhibitor that specifically targets the BCR-ABL protein and induces hematological remission in patients with chronic myeloid leukemia (CML). Unfortunately, the majority of CML patients treated with imatinib develop resistance under prolonged therapy. We here investigated the methylation profile of SOCS-3 gene and its downstream effects in a BCR-ABL positive CML cells resistant to imatinib. Materials and Methods: BCR-ABL positive CML cells resistant to imatinib (K562-R) were developed by overexposure of K562 cell lines to the drug. Cytotoxicity was determined by MTS assays and $IC_{50}$ values calculated. Apoptosis assays were performed using annexin V-FITC binding assays and analyzed by flow cytometry. Methylation profiles were investigated using methylation specific PCR and sequencing analysis of SOCS-1 and SOCS-3 genes. Gene expression was assessed by quantitative real-time PCR, and protein expression and phosphorylation of STAT1, 2 and 3 were examined by Western blotting. Results: The $IC_{50}$ for imatinib on K562 was 362nM compared to 3,952nM for K562-R (p=0.001). Percentage of apoptotic cells in K562 increased upto 50% by increasing the concentration of imatinib, in contrast to only 20% in K562-R (p<0.001). A change from non-methylation of the SOCS-3 gene in K562 to complete methylation in K562-R was observed. Gene expression revealed down-regulation of both SOCS-1 and SOCS-3 genes in resistant cells. STAT3 was phosphorylated in K562-R but not K562. Conclusions: Development of cells resistant to imatinib is feasible by overexposure of the drug to the cells. Activation of STAT3 protein leads to uncontrolled cell proliferation in imatinib resistant BCR-ABL due to DNA methylation of the SOCS-3 gene. Thus SOCS-3 provides a suitable candidate for mechanisms underlying the development of imatinib resistant in CML patients.

Removal of Phenanthrene by Electrokinetic-Fenton Process in a 2-dimensional Soil System (동전기-펜턴 공정을 이용한 2차원 토양 정화장치에서의 phenanthrene 제거)

  • Park Ji-Yeon;Kim Sang-Joon;Lee You-Jin;Yang Ji-Won
    • Journal of Soil and Groundwater Environment
    • /
    • v.10 no.5
    • /
    • pp.11-17
    • /
    • 2005
  • Characteristics of phenanthrene removal in the Electrokinetic (EK)-Fenton process were investigated in a 2-dimensional test cell in a viewpoint of the effect of gravity and electrosmotic flow (EOF). When the constant voltage of 100 V was applied to this system, the current decreased from 1,000 to 290 mA after 28 days, because soil resistance increased due to the exhaustion of ions in soil by electroosmosis and electromigration. Accumulated EOF in two cathode reservoirs was 10.3 L and the EOF rate was kept constant for 28 days. At the end of operation, the concentration of phenanthrene was observed to be very low near the anode and increased in the cathode region because hydrogen peroxide was supplied from anode to cathode region following the direction of EOP. Additionally, the concentration of phenanthrene decreased at the bottom of the test cell because the electrolyte solution containing hydrogen peroxide was largely transported toward the bottom due to a low capillary action in the soil with high porosity. Average removal efficiency of phenanthrene by EK-Fenton process was 81.4% for 28 days. In-situ EK-Fenton process would overcome the limitations of conventional remediation technologies and effectively remediate the contaminated sites.

Investigation of Pyroprocessing Concept and Its Applicability as an Alternative Technology for Conventional Fuel Cycle (고온전해분리 기술의 개요 및 기존 핵연료주기 대체 기술로서의 적합성 검토)

  • Yoo, Jae-Hyung;Lee, Byung-Jik;Lee, Han-Soo;Kim, Eung-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.5 no.4
    • /
    • pp.283-295
    • /
    • 2007
  • The technical feasibility of a pyroprocessing of PWR spent fuels to recover nuclear fuel materials, uranium and transuranic elements group(TRU), was examined in this study. Also its applicability as a new fuel cycle technology in terms of non-proliferation was investigated. First, various unit processes were combined to a pyroprocess. Then the flow aspects of such materials of issue as uranium, transuraniums, rare earth, noble metals and heat generating elements were examined on the flowsheet, which was obtained by the assumptions on the basis of various experimental results in this work or separation data collected from literatures. Consequently, the calculated results of the material balance for the whole process showed that uranium and TRU could be recovered as products by 98.0 % and 97.0 %, respectively, from a PWR spent fuel while removing the other elemental groups into radioactive wastes. On the one hand, the TRU product was found to emit a considerable amount of ${\gamma}$-ray as well as neutrons favorably contributing to the strategy of proliferation resistance.

  • PDF

Compressive Strength and Chloride Permeability of High Strength Concrete according to the Variety of Mineral Admixtures (광물질혼화재 종류별 고강도콘크리트의 압축강도 및 촉진 염소이온침투 특성)

  • Moon Han-Young;Kim Byoung-Kwon
    • Journal of the Korea Concrete Institute
    • /
    • v.16 no.3 s.81
    • /
    • pp.407-414
    • /
    • 2004
  • The purpose of this study is to evaluate the ability to resist chloride ions penetration of the concrete structure under marine environment in south-east asia especially. In this study, high strength concrete(HSC) with various combination of ordinary portland cement(OPC), blast-furnace slag(SG) and silica fume(SF) are cured 23 and $35^{\circ}C$ considering the site weather, and are cured in water for 3, 7 or 56 days respectively. And to investigate the fundamental properties and the resistance of chloride penetration of various HSC, setting time, slump flow, compressive strength, void and ASTM C 1202 test were conducted. Test results show that the compressive strength of HSC is similar regardless of SG replacement ratio and total charge passed of chloride is the smallest at 40% replacement of SG. The compressive strength of G4FS HSC is, besides, outstandingly high at early age compare with other HSC, but the compressive strength of G4F HSC, which is vary according to curing temperature and condition, most high at the age after 7 days. Total passed charge of HSC get larger in the order G4FS

Autogenous Shrinkage Mock-up Test of High Performance Concrete by Emulsified Refined Cooking Oil (유화처리 정제식용유를 사용한 고성능 콘크리트의 자기수축 Mock-up 실험)

  • Jo, Man-Ki;Han, Cheon-Goo
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.4 no.3
    • /
    • pp.307-315
    • /
    • 2016
  • The aim of this research is analyzing the fundamental properties and autogenous shrinkage reducing performance of 70 and 100MPa grade high performance concrete including emusified refined cooking oil(ERCO) under the mock-up conditions. As a results of experiment, the mixture contained 0.5% of ERCO showed slightly decreased slump flow while the slump was increased and segregation resistance performance was improved as 2.5 of EIS. For air content, all mixtures satisfied target air content with increased unit weight and delayed setting time with ERCO addition. In the case of compressive strength, when ERCO was added 0.5%, the result of approximately 5 to 10% of increased compressive strength was observed. For the autogenous shrinkage, ERCO contributed on 20-30% of shrinkage reducing performance comparing to Plain mixture without ERCO. It is considered that capillary pore filling action of soap particles occurred by the reaction of ERCO in cement paste between fatty aicd and calcium hydroxide contributed the shrinkage reducing performance. Based on these mock-up test results, application of the high performance concrete mixture with ERCO on CFT actual structure was decided.

Sevoflurane Insufflation Sedation for the Dental Treatment of a Patient with Pulmonary Arterial Hypertension : A Case Report (폐동맥 고혈압 환자의 치과치료에서 세보플루란 흡입 진정의 사용 : 증례보고)

  • Chi, Seongin;Kim, Seungoh
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.42 no.1
    • /
    • pp.75-79
    • /
    • 2015
  • Pulmonary arterial hypertension (PAH) is a common complication of Congenital heart defects (CHD) with left-to-right shunts, and PAH with increased pulmonary vascular resistance (PVR) is associated with considerable morbidity and mortality. General anesthesia (GA) can be life-threatening in patients with PAH, because the positive pressure ventilation during GA increases pulmonary arterial pressure and decreases pulmonary blood flow. This may also lead to hypoxia. Therefore, spontaneous ventilation may be safer than positive pressure ventilation in patients with PAH. A five-year-old male child, weighing 11 kg, with medical history showing a total correction of Tetralogy of Fallot (TOF) in 2009 and ongoing treatment with hypertension (HTN) medicine since 2007, visited the Dankook University Dental Hospital. He had multiple dental caries, and the treatment was completed under sevoflurane insufflation sedation via nasal cannula. The patient remained sedated throughout the operation while maintaining normal vital signs and spontaneous respiration. In conclusion, sevoflurane insufflation sedation may be a safer alternative to GA for the dental treatment of patients with PAH.

Improvement of Solar Cell Efficiency according to AC Voltage Variation of Electron Relay Enhancer in High Efficient Solar Cell System using Electron Relay Enhancer (전자전달증대기를 이용한 고효율 태양전지 시스템에서 전자전달증대기 입력 교류 전압 변화에 따른 태양전지 효율 향상에 대한 연구)

  • Kim, Hak Soo;Ryu, Young Kee;Lee, Hyuk;Yun, So Young
    • Journal of the Korean Vacuum Society
    • /
    • v.22 no.3
    • /
    • pp.168-173
    • /
    • 2013
  • In this paper, we would like to introduce Electron Relay Enhancer (ERE), a supplementary device, which improves commercial solar cell efficiency minimizing electron-hole recombination of solar cell. The ERE in this study is mainly composed of two capacitors which are connected to AC power source and bridge diode system which controls electron flow direction. Two capacitors repeat collecting electrons from solar cell and pumping the collected electrons to load resistance or inverter through the bridge diode system. While one positively charged capacitor collect electrons, the other negatively charged one pumps electrons. A positively charged capacitor pulls the more exited electrons from the solar cell, before the exited electrons recombine the holes in solar cell. That is why the ERE system enhances solar cell efficiency. As a result, the measured power increase of the solar cell with the ERE is varied from 5.9 W to 25.6 W in each experimental condition. Maximal increase rate of the solar cell power with ERE is 30.8% of solar cell power without ERE.

Effect of $N_2$-back-flushing Time and TMP in Lake Water Treatment Using Multichannel Ceramic Microfiltration Membranes (다채널 세라믹 정밀여과막으로 호소수 처리시 질소 역세척 시간 및 막간 압력차의 영향)

  • Park, Jin-Yong;Park, Bo-Reum
    • Membrane Journal
    • /
    • v.17 no.2
    • /
    • pp.124-133
    • /
    • 2007
  • In this study, we treated lake water by 2 kinds of multichannel ceramic micro filtration membranes. We could investigate effects of $N_2-back-flushing$ time (BT) and transmembrane pressure (TMP), and find optimal operating conditions. The BT were changed in $10{\sim}60$ sec, TMP in $0.6{\sim}2.0$ bar at fixed filtration time (FT) 8 min, flow rate 2.0 L/min and back-flushing pressure 2.0 bar. Also, the optimal conditions were discussed in the viewpoints of resistance of membrane fouling $(R_f)$, dimensionless permeate flux $(J/J_o)$, permeate flux (J) and total permeate volume $(V_T)$. As result, optimal back-flushing conditions for HC04 ($0.4{\mu}m$ pore size) and HC10 membrane $(1.0{\mu}m)$ were BT=10 sec and BT=20 sec, respectively. Then, higher TMP should increase the driving force, and could produce more VT. Average rejection rates of pollutants were higher than 95.4% for turbidity, $12.7{\sim}20.1%\;for\;COD_{Mn},\;0.0{\sim}6.4%\;for\;NH_3-N,\;1.9{\sim}4.6%$ for T-N and $34.9{\sim}88.4%$ for T-P.

Dual Coating Improves the Survival of Probiotic Bifidobacterium Strains during Exposure to Simulated Gastro-Intestinal Conditions (위장관내 조건에서 이중코팅 처리 된 프로바이오틱 비피도박테리움의 생존력 향상)

  • Kang, Joo Yeon;Lee, Do Kyung;Park, Jae Eun;Kim, Min Ji;Lee, Joong-Su;Seo, Jae-Gu;Chung, Myung Jun;Shin, Hea Soon;Ha, Nam Joo
    • Korean Journal of Microbiology
    • /
    • v.49 no.3
    • /
    • pp.275-281
    • /
    • 2013
  • Probiotics have been reported to benefit human health by modulating immunity, lowering cholesterol, improving lactose tolerance, and preventing some cancer. Once ingested, probiotic microorganisms have to survive harsh conditions such as low pH, protease-rich condition, and bile salts during their passage through the gastro-intestinal (GI) tract colonize and proliferate to exert their probiotic effects. The dual coating technology, by which the bacteria are doubly coated with peptides and polysaccharides in consecutive order, was developed to protect the ingested bacteria from the harsh conditions. The aim of the study was to evaluate the viable stability of a doubly coated blend of four species of Bifidobacterium by comparing its bile/acid resistance and heat viability in vitro with that of the non-coated blend. After challenges with acid, bile salts, heat, and viable cell counts (VVCs) of the dual coated and non-coated blend were determined by cultivation on agar plates or flow cytometric measurement after being stain with the BacLigtht kit$^{TM}$. The results showed that the dual coated blend was much higher resistant to the acidic or bile salt condition than the non-coated blend and heat viability was also higher, indicating that the dual coating can improve the survival of probiotic bacteria during their transit through the GI tract after consumption.

Heat Exchanging Performance as Affected by Arrangement of Heat Exchanging Pipe (열회수장치의 열교환 파이프배치 형식별 열교환 성능)

  • 윤용철;강종국;서원명
    • Journal of Bio-Environment Control
    • /
    • v.11 no.3
    • /
    • pp.101-107
    • /
    • 2002
  • This study was carried out to improve the performance of heat recovery device attached to exhaust gas flue connected to combustion chamber of greenhouse heating system. Three different units were prepared far the comparison of heat recovery performance; A-type is exactly the same with the typical one fabricated for previous study of analyzing heat recovery performance in greenhouse heating system, other two types (B-type and C-type) modified from the control unit are different in the aspects of airflow direction (U-turn airflow) and pipe arrangement. The results are summarized as follows ; 1. In the case of Type-A, when considering the initial cost and current electricity fee required for system operation, it was expected that one or two years at most would be enough to return the whole cost invested. 2. Type-B and Type-C, basically different with Type-A in the aspect of airflow pattern, are not sensitive to the change of blower capacity with higher than 25m$^3$.min$^{-1}$ . Therefore, heat recovery performance was not improved so significantly with the increment of blower capacity. This was assumed to be that air flow resistance in high air capacity reduced the heat exchange rate as well. Never the less, compared with control unit, resultant heat recovery rate of Type-B and Type-C was improved by about 5% and 13%, respectively 3. Desirable blower capacity of these heat recovery units experimented were expected to be about 25m$^3$.min$^{-1}$ , and at the proper blower capacity, U-turn airflow units showed better heat recovery performance than control unit. But, without regard to the type of heat recovery unit, it was recommended that comprehensive consideration of system's physical factors such as pipe arrangement density, unit pipe length and pipe thickness, etc., was required for the optimization of heat recovery system in the aspects of not only energy conservation but economic system design.