• 제목/요약/키워드: pH dependent

검색결과 1,769건 처리시간 0.036초

Comparison of Flocculation Characteristics of Humic Acid by Inorganic and Organic Coagulants: Effects of pH and Ionic Strength

  • Xu Mei-Lan;Lee Min-Gyu;Kam Sang-Kyu
    • 한국환경과학회지
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    • 제14권8호
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    • pp.723-737
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    • 2005
  • The effects of pH (5, 7 and 9) and ionic strength of different salts on the flocculation characteristics of humic acid by inorganic (alum, polyaluminum chloride (PAC) with degree of neutralization, r=(OH/Al) of 1.7) and organic (cationic polyelectrolyte) coagulants, have been examined using a simple continuous optical technique, coupled with measurements of zeta potential. The results are compared mainly by the mechanisms of its destabilization and subsequent removal. The destabilization and subsequent removal of humic acid by PAC and cationic polyelectrolyte occur by a simple charge neutralization, regardless of pH of the solution. However, the mechanism of those by alum is greatly dependent on pH and coagulant dosage, i.e., both mechanisms of charge neutralization at lower dosages and sweep flocculation at higher dosages at pH 5, by sweep flocculation mechanism at pH 7, and little flocculation because of electrostatic repulsion between negatively charged humic acid and aluminum species at pH 9. The ionic strength also affects those greatly, mainly based on the charge of salts, and so is more evident for the salts of highly charged cationic species, such as $CaCl_2$ and $MgCI_2.$ However, it is found that the salts have no effect on those at the optimum dosage for alum acting by the mechanism of sweep flocculation at pH 7, regardless of their charge.

Salvia miltiorrhiza Inhibits Tumor Cell Growth in Association with Rb Dephosphorylation through Up-regulation of p21 Via a p53-dependent Pathway

  • Chung, Jin;Chang, Jae-Eun;Son, Yong-Hae;Park, Hae-Ruyn;Lim, Suk Hwan;Oh, Yang-Hyo;Lee, Moo-Yeol;Park, Yeong-Min
    • IMMUNE NETWORK
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    • 제2권1호
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    • pp.19-24
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    • 2002
  • Background: Salvia miltiorrhiza (SM), a traditional oriental medicine, has been reported to have anti-tumor properties, but its exact mechanism remains to be elucidated. In this study, we investigated several of the molecular events that occur in human breast carcinoma MCF-7 cells and human pulmonary adenocarcinoma A549 cells. Methods: For this purpose, we evaluated the growth-inhibitory effect of SM in association with the expressions of p53, p21, cyclin D1, and pRb, which are known to be involved in cell cycle arrest. The extent of thymidine incorporation was also examined to assess G1/S phase cell cycle arrest in both cells by $^3H$-thymidine incorporation. Results: Our results show that SM inhibits the growth and the proliferation of MCF-7 and A549 cells. Furthermore, we also observed increased expression of p21 via a p53-dependent pathway in both cell lines after treating with SM. In addition, treatment with SM for 24 hours caused the suppression of hyperphosphorylated retinoblastoma protein (pRb) expression and the dephosphorylation of pRb. Conclusion: These findings suggest that the growth inhibitory and the anti-proliferation effects of SM on MCF-7 cells and A549 cells are mediated via the decreased expression and dephosphorylation of pRB by p21 up-regulation in a p53-dependent manner. To the best of our knowledge, this study is the first to report upon the molecular mechanisms involved in SM-induced tumor cell growth inhibition.

Effect of Epididymal Fluid on In Vitro Maturation and Subsequent Sperm Penetration in Porcine Follicular Oocytes

  • Kim, Byung-Ki
    • Reproductive and Developmental Biology
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    • 제33권3호
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    • pp.125-131
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    • 2009
  • The aim of this study is to investigate the effect of porcine epididymal fluid (pEF) on in vitro-maturation and subsequent fertilization of porcine follicular oocytes. Porcine cumulus-oocytes complexes retrieved from antral follicles were cultured in tissue culture medium (TCM)-l99 supplemented with pEF of different concentrations. At 48 h after culture, development of oocytes to germinal vesicle (GV) breakdown, metaphase I, anaphase-telophase I, and metaphase II were examined Significant (p<0.05) increase in the proportion of oocytes developed to MII stage was observed in oocytes cultured in pEF-containing TCM-l99 than in oocytes cultured in pEF-free TCM-199 (46.2% vs 16.7%), which was a dose-dependent manner. Subsequently, the proportion of monospermic fertilization were significantly (p<0.05) increased in oocytes cultured in the TCM supplemented with pEF than those cultured in pEF-free TCM-199 (51.0% vs 24.1%). In the second series of experiment, the percentage of MII oocytes was significantly (p<0.05) increased after exposure of oocytes to pEF during the first 22 h period of culture than after exposure of oocytes to pEF during the next 24 h of culture, while no significant difference in the percentage of monospermy was observed. The results of this study demonstrate that pEF contains at least enhancing component(s) for nuclear maturation.

Cadmium Inhibition of Renal Endosomal Acidification

  • Kim, Moo-Seong;Kim, Kyoung-Ryong;Ahn, Do-Whan;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.63-72
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    • 2000
  • Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

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편측성 폐질환 환자의 체위변경이 생리적 지표에 미치는 영향 (The Effect of Body Positioning on Physiologic Index in Patients with Unilateral Lung Disease)

  • 조지연;이향련
    • 성인간호학회지
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    • 제12권1호
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    • pp.122-133
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    • 2000
  • The purpose of this study was to identify the effect of body positioning on $PaO_2$, $SpO_2$, systolic blood pressure, diastolic blood pressure, pulse, and respiration(above all defined physiologic index), of patients with unilateral lung disease. The subjects for this study were eleven patients admitted to I.C.U. of K.H.M.C. with a diagnosis of unilateral lung disease confirmed by chest X-ray and the attending doctor, from January 30th. to April 20th. 1999. A quasi-experimental repeated-measures cross-over design was used to compare three body positions(semi-Fowler's, lateral decubitus with good lung dependent, and lateral decubitus with diseased lung dependent). Each subject spent 30 minutes in semi-Fowler's position and 2 hours in good lung dependent position and diseased lung dependent position. Starting in the semi-Fowler's position, then in the lateral position with the good lung dependent or the diseased lung dependent as assigned in random order. Thirty minutes after each positioning, arterial blood sample was analyzed. Measurements of all physiologic index were recorded at the specified intervals(0, 30, 60 90, and 120 minutes) in good lung dependent and diseased lung dependent position. Statistical comparison of $PaO_2$ value was done using the Wilcoxon Signed Rank Test, and Multivariate repeated-measures analysis of variance was performed to analyse the within-subject effect of two dependent position for 2 hours on the five dependent variables: (1) $PaO_2$ (2) $SpO_2$ (3) systolic blood pressure (4) diastolic blood pressure (5) pulse. The results obtained were as follows: 1. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the diseased lung dependent position(Z=-2.8451, p=.002). 2. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the semi-Fowler's position (Z=-2.6673, p=.003). 3. The difference between the $PaO_2$ value in the semi-Fowler's position and the $PaO_2$ value in the diseased lung dependent position was not significant(Z=-1.2448, p=.10). 4. There were no statistically significance in the trends of physiologic index in the good lung dependent position and the diseased lung dependent position. From the results, it may be concluded that the good lung dependent position is the most effective position for patients with unilateral lung disease that improve oxygenation. Identification of positioning over time may be need further studies.

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상황을 이용한 한의학적 보건기능 개선제에 의한 인체폐암세포의 증식억제에 관한 연구 (Down-regulation of COX-2 and hTERT Expression by Healthful Decoction Utilizing Phellinus Linteus in Human Lung Carcinoma Cells)

  • 박철;이용태;정영기;최병태;이상현;최영현
    • 동의생리병리학회지
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    • 제18권2호
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    • pp.500-506
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    • 2004
  • The objective of the present study was to investigate the effects of aqueous extract from the healthful decoction utilizing Phellinus linteus (HDPL) on the growth of human lung carcinoma A549 cells. HDPL treatment declined the cell viability of A549 cells in a concentration-dependent manner and the anti-proliferative effects by HDPL treatment were associated with morphological changes such as membrane shrinking and cell rounding up. HDPL treatment did not affect the distribution of the cell cycle. Western blot analysis and RT-PCT data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21WAF1/CIP1 in HDPL-treated A549 cells were remained unchanged. However, HDPL treatment inhibited the expression of cyclooxygenase-2 (COX-2) mRNA and protein in a concentration-dependent fashion. Additionally, the expression of human telomerase reverse transcriptase (hTERT), a main determinant of the telomerase enzymatic activity, was progressively down-regulated by HDPL treatment. Taken together, these findings suggest that HDPL-induced inhibition of human lung cancer cell proliferation is associated with the inhibition of several major growth regulatory gene products, such as COX-2 and hTERT, and HDPL may have therapeutic potential in human lung cancer.

천도복숭아 식초의 이화학적 특성과 항산화 및 알코올 대사 효소 활성 (Physiochemical Properties, and Antioxidative and Alcohol-metabolizing Enzyme Activities of Nectarine Vinegar)

  • 정경임;정한나;하나연;최영주
    • 생명과학회지
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    • 제28권10호
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    • pp.1193-1200
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    • 2018
  • 본 연구에서는 전통적인 방법으로 제조한 천도복숭아식초의 이화학적 특성과 항산화 작용, 아질산염 소거능 및 알코올 대사 효소 활성을 알아보았다. 천도복숭아식초의 pH는 3.70이였고, 당도는 $8.87^{\circ}Brix$였으며, 총산도는 6.29%로 나타났다. 천도복숭아식초의 유기산 분석 결과 acetic acid가 32.42 mg/ml로 가장 높았고, 그 다음으로 lactic acid, succinic acid, malic acid의 순으로 나타났다. 천도복숭아식초의 총 페놀함량은 $121.84{\mu}g\;TAE/100ml$로 나타났다. 천도복숭아식초의 DPPH radical 소거능은 농도 의존적으로 증가하였으며 40% 농도에서 84.47%의 소거능을 보였다. SOD 활성 또한 농도 의존적으로 증가하였으며 60% 농도에서 89.06%로 나타났다. 아질산염 소거능 분석에서는 천도복숭아식초 100% 농도, pH 1.2, 3.0, 6.0에서 각각 94.17, 76.91, 20.21%로 pH가 낮을수록 아질산염 소거능이 증가하는 것으로 나타났다. 천도복숭아 식초의 알코올 분해효과를 알아보기 위하여 ADH 활성 및 ALDH 활성을 분석한 결과, ADH 활성 및 ALDH 활성 모두 농도 의존적으로 증가하였으며, 60% 농도에서 각각 153.61%와 178.20%로 나타났다. 이상의 결과에서와 같이 전통적인 방법으로 제조한 천도복숭아식초는 기능성 건강음료로서의 가능성이 있음을 확인할 수 있었다.

막걸리 열수 추출물의 아질산염 소거능, 알코올 분해능 및 angiotensin converting enzyme 저해 효과 (Nitrite Scavenging and Alcohol Metabolizing Activities of Hot Water Extract from Makgeoly and Its Angiotensin Converting Enzyme Inhibitory Effect)

  • 조은경;김희연;변현지;김수원;최영주
    • 생명과학회지
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    • 제20권5호
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    • pp.768-774
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    • 2010
  • 전통발효주 막걸리의 기능성을 증명하기 위하여 S사막걸리로부터 구입한 막걸리 침전물의 여러 가지 생리활성에 대하여 조사하였다. 우선 막걸리 침전물 열수 추출물의 항산화 효과를 측정하기 위해 DPPH radical 소거능과 SOD 유사활성을 측정하였다. 그 결과 DPPH법을 통해 측정한 막걸리 침전물 열수 추출물의 radical 소거능은 10 mg/ml에서 48.0%으로 나타났으며, 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었다. 또한 SOD 유사활성은 10 mg/ml 농도에서 98.7%로 비교적 높은 SOD 유사활성을 보였다. 항고혈압 활성 측정 실험에서는 현재 시판되고 있는 항고혈압제인 captopril은 0.1 mg/ml에서 93.4%의 ACE 억제효과가 나타났고, 막걸리 침전물 열수 추출물 10 mg/ml에서는 74.0%의 높은 저해 활성을 나타내었다. 따라서, 막걸리 침전물 열수 추출물은 인체에 부작용이 적은 천연 항고혈압소재로서 이용가능성이 높은 것으로 사료된다. 아질산염 소거능 측정 실험에서는 positive control인 Vit. C1 mg/ml의 경우 pH 1.2와 3.0에서는 74~64%, pH 6.0에서는 45%의 소거능을 보인반면, 막걸리 침전물 열수 추출물의 경우 pH 1.2와 3.0에서는 51~42%, pH 6.0에서는 28%의 소거능을 나타내었다. 막걸리 침전물 열수 추출물의 숙취해소 효능은 ADH와 ALDH 활성증진에 막걸리 침전물 열수 추출물이 미치는 영향을 조사함으로써 증명하고자 하였다. 그 결과, 알콜과 acetaldehyde 분해능은 높게 나타났다. 이상의 결과들은 막걸리 침전물의 우수한 기능성으로서의 이용 가능성에 대한 기초자료로 그 가치가 기대된다.

인체폐암세포 NCI-H460 및 A549의 증식에 미치는 삼기보폐탕의 영향 비교 (Induction of Apoptosis by Samgibopae-tang in Human Non-small-cell Lung Cancer Cells)

  • 허만규;박철;최영현;감철우;박동일
    • 동의생리병리학회지
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    • 제21권4호
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    • pp.973-981
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    • 2007
  • In the present study, we investigated the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines. We found that exposure of A549 cells to SGBPT resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay, however SGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. SGBPT treatment did not induce the cell cycle arrest in both cell lines, however the frequency of sub-G1 population was concentration-dependently increased by SGBPT treatment in A549 cells. SGBPT treatment partially induced the expression of tumor suppressor p53 in A549 cells and the expression of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was markedly increased in both transcriptional and translational levels in A549 cells. The up-regulation of p21 by SGBPT occurred in a similar a concentration dependent manner to that observed with the inhibition of cell viability and induction of sub-G1 population of the cell cycle. However SGBPT treatment did not affect other growth regulation-related genes such as early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1), inducible nitric oxide synthease (iNOS), cyclooxygenases (COXs), telomere-regulatory factors in A549 as well as NCI-H460 cells. Taken together, these findings suggested that SGBPT-induced inhibition of human lung carcinoma A549 cell growth was aoosciated with the induction of p21 and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

우슬이 산화적 스트레스와 관련한 세포내 신호전달계에 미치는 영향 (Effect of Achyrantis Radixs on Rat Chondrocyte Oxidative Stress and Its Signal Transduction)

  • 김은정;정현우;김계엽
    • 동의생리병리학회지
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    • 제22권4호
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    • pp.841-848
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    • 2008
  • Archyranthes radix has had extensive therapeutic application, and there has been increasing interest in its biological effects. However, the biochemical effects of Archyranthes radix on chondrocyte oxidative stress have never been systematically investigated. Therefore, we investigated the effects of Acyranthes radix on role of MAPK signal transduction pathway on oxidative stress induced by hydrogen peroxide in rat articular chondrocytes. The statistically significant inhibitory action of Archyranthes radix on cell proliferation was observed at above $5{\mu}g/m{\ell}$. Next, we examined the time-dependent effect of $5{\mu}g/m{\ell}$ Archyranthes radix on cell proliferaion. Archyranthes radix significantly inhibited cell proliferation from 12 hr after treatment (P<0.05). $H_2O_2$, resulted in a time- and dose-dependent cell proliferation, which was largely attributed to oxidative damage. Acyranthes radix and $H_2O_2$ treatment caused marked sustained activation of phosphorylation of ERK1/2. Moreover, the synergistic phosphorylation of p44/42 MAPK by $H_2O_2$ and Archyranthes radix was selectively inhibited by PD 98059, a p44/42 MAPK inhibitor. In conclusion, these results are consistent with the hypothesis that under conditions of oxidative stress, the $H_2O_2$-induced inhibition of cell proliferation in the rat chondrocyte is mediated through a modulation of the Archyranthes radix signaling pathway, promoting further phosphorylation of p44/42 MAPK, indicating a potentially important role in cartilage repair and in the treatment of osteoarthritic cartilage.