• Title/Summary/Keyword: Ion Channel

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Arsenic removal from artificial arsenic water using CaAl-monosulfate and CaAl-ettringite (CaAl-monosulfate와 CaAl-ettringite를 이용한 인공비소폐수의 비소 제거 연구)

  • Shim, Jae-Ho;Kim, Ki-Baek;Choi, Won-Ho;Park, Joo-Yang
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.1
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    • pp.141-148
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    • 2012
  • The objective of this study is to remove arsenate from artificially contaminated wastewater using CaAl-ettringite and CaAl-monosulfate which were synthesized in laboratory. The study was carried on the basis of solidification/stabilization of waste using cement. Monosulfate and ettringite are constituents of cement paste. The CaAl-ettringite has a chemical formula of $Ca_6Al_2O_6(SO_4)_3{\cdot}32H_2O$ and has a needle like morphology. Whereas CaAl-monosulfate $Ca_4Al_2O_6(SO_4){\cdot}12H_2O$ has layered double hydroxide structure (LDH) in which the mainlayer consists of Ca and Al and S as interlayer. Ettringite and monosulfate were synthesized by reaction of tricalcium aluminate and gypsum and hydrating this mixture at elevated temperature. The synthesized mineral were characterized by PXRD and FESEM to ensure purity. It was found that concentrations of As(V) in contaminated water were reduced from initial concentration of 1.335 mmol/L to 0.054 mmol/L and 0.300 mmol/L by CaAl-monosulfate and CaAl-ettringite respectively. The post experimental results of PXRD and FESEM analysis indicate that arsenate removal was by ion exchange.

Inhibition of Transient Receptor Potential Melastain 7 Enhances Apoptosis Induced by TRAIL in PC-3 cells

  • Lin, Chang-Ming;Ma, Ji-Min;Zhang, Li;Hao, Zong-Yao;Zhou, Jun;Zhou, Zhen-Yu;Shi, Hao-Qiang;Zhang, Yi-Fei;Shao, En-Ming;Liang, Chao-Zhao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4469-4475
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    • 2015
  • Transient receptor potential melastain 7 (TRPM7) is a bifunctional protein with dual structure of both ion channel and protein kinase, participating in a wide variety of diseases including cancer. Recent researches have reported the mechanism of TRPM7 in human cancers. However, the correlation between TRPM7 and prostate cancer (PCa) has not been well studied. The objective of this study was to investigate the potential the role of TRPM7 in the apoptosis of PC-3 cells, which is the key cell of advanced metastatic PCa. In this study, we demonstrated the influence and potential function of TRPM7 on the PC-3 cells apoptosis induced by TNF-related apoptosis inducing-ligand (TRAIL). The study also found a novel up-regulated expression of TRPM7 in PC-3 cells after treating with TRAIL. Suppression of TRPM7 by TRPM7 non-specific inhibitors ($Gd^{3+}$ or 2-aminoethoxy diphenylborate (2-APB) ) not only markedly eliminated TRPM7 expression level, but also increased the apoptosis of TRAIL-treated PC-3 cells, which may be regulated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway accompany with up-regulated expression of cleaved Caspase-3, (TRAIL-receptor 1, death receptors 4) DR4, and (TRAIL-receptor 2, death receptors 5) DR5. Taken together, our findings strongly suggested that TRPM7 was involved in the apoptosis of PC-3 cells induced by TRAIL, indicating that TRPM7 may be applied as a therapeutic target for PCa.

In vitro Effect of High Osmolality on Plasma Membrane Activities in the Spermatozoa (In Vitro 고삼투압이 정자 원형질막의 Protein Tyrosine Phosphorylation에 미치는 영향)

  • 오영근;장재호;최인호;정노팔;신형철;곽병주
    • Biomedical Science Letters
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    • v.6 no.4
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    • pp.237-244
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    • 2000
  • It has been reported that plasma membrane activity of the spermatozoa may be susceptible to be influenced by extracellular osmolality and such membranous changes involve infracellular molecular changes, special regard to the structure of membranous lipids, and the accompanying ion-channel of which are closely related with their fluidity of $Ca^{2+}$ and HCO$^{-}_{3}$. It is of common recognition that a certain kind of sterol acceptor player an important to induce lipid fluctuation of the sperm plasma membrane which have been influenced by BSA administration and came in effect to outflow of cholesterol from the spermatozoa and resulted in changes of ionic fluidity to facilitate adenylyl cyclase, and to induce protein tyrosine phosphorylation by increase of cAMP and activation of PKA. Thus it seems likely that an augmentation of the acrosomal reaction is closely related with protein tyrosine phosphorylation. The following experimental results were obtained in the present study; Under the high osmolality conditions, the spermatozoa motility declined significantly and the structural change of the plasma membrane diminished to confirm that the response degrees to the osmolality depended upon the water transfer volume through the plasma membrane and the changes of cellular volume. Those experimental results suggest that a physiological parameter such as low temperature condition played an important role for presentation of spermatozoa and that inducement of spermatozoa activation for reinforcement of protein tyrosine phosphorylation. On the other hand, it seemed likely that the BSA administration as one of sterol accepters might represent a key role also under the high osmolality condition and their result also suggests that osmolality change, special regard to high osmolality condition may play an important role also in the processes of signal transmission.

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가스장 이온원 시스템에서 마이크로 채널 플레이트의 잡음 제거 방법

  • Han, Cheol-Su;Park, In-Yong;Jo, Bok-Rae;Park, Chang-Jun;An, Sang-Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.422.2-422.2
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    • 2014
  • 가스장 이온원(GFIS: Gas Field Ionization Source)은 전자현미경보다 분해능이 향상된 이온현미경의 광원으로 사용하기 위하여 연구되고 있고, 큰 각전류 밀도, 작은 크기의 가상 이온원 그리고 좁은 에너지 퍼짐을 특징으로 한다. 여러 가지 장점을 가지고 있는 GFIS을 개발하기 위해서는 GFIS에서 발생된 이온빔의 형상을 관찰 것이 매우 중요하며, 이러한 관찰을 위한 시스템에는 주로 마이크로 채널 플레이트 (MCP: Micro Channel Plate)가 사용된다. MCP는 채널내부에 입사한 입자의 에너지에 의해서 생성된 이차전자를 수 천 배에서 수 백 만 배 이상 증폭시켜 형광판에 조사하고 발광시키는 방법으로 작은 신호를 영상으로 관찰 할 수 있도록 한다. MCP의 큰 증폭비는 작은 크기의 신호를 큰 신호로 증폭하여 관찰하는데 용이하여, GFIS 방법으로 생성된 이온빔(이온빔 전류 값은 pA 수준)을 관찰하기에 적합하다. 그러나 MCP를 이용하여도 증폭된 이온빔의 세기가 매우 작기때문에 생성된 이온빔 형상을 정확하게 관찰하기 위해서는 MCP의 형광판을 촬영하는 카메라 노출시간을 길게하여 데이터 수집 시간을 늘려야 하는 문제가 있다. 본 발표에서는 이온빔 형상 관찰에 소요되는 시간을 단축하기 위하여 MCP의 잡음이 GFIS의 이온빔 이미지 관찰에 미치는 영향을 분석하고 이를 제거 방법을 소개한다. 본 연구에서는 GFIS 방출 이온빔의 이미지에 포함된 MCP 잡음 특성을 장(전계)이온현미경 (Field Ion Microscope)실험을 통하여 분석하였고, 디지털 이미지 처리 방법을 이용하여 방출 이온빔 이미지에서 MCP 잡음을 제거하여 방출 이온빔 이미지만 추출할 수 있었다. 본 연구에서 제안한 방법을 GFIS 방출 이온빔 관찰시스템에 적용함으로써 기존 방법에 비해 노출시간을 단축하여 방출 이온빔을 관찰 할 수 있었으며, 노이즈 제거 효과로 향상된 이온빔 형상을 얻을 수 있었다. 본 연구결과의 관찰시간 단축과 향상된 이온빔 형상 획득은 이온현미경 개발에 필수적인 단원자 이온빔을 보다 효율적으로 개발할 수 있으며 디지털 이미지 처리로 GFIS 이온빔 생성을 자동화하는데 응용할 수 있다. 더불어 기존방법에 비해 이미지 획득을 위한 MCP의 노출시간을 단축할 수 있으므로 실험장비 수명 단축 방지 및 관리에 큰 장점이 있다.

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Increased Sensitivity of Carbon Nanotube Sensors by Forming Rigid CNT/metal Electrode

  • Park, Dae-Hyeon;Jeon, Dong-Ryeol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.348-348
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    • 2011
  • Carbon nanotube (CNT) field effect transistors and sensors use CNT as a current channel, of which the resistance varies with the gate voltage or upon molecule adsorption. Since the performance of CNT devices depends very much on the CNT/metal contact resistance, the CNT/electrode contact must be stable and the contact resistance must be small. Depending on the geometry of CNT/electrode contact, it can be categorized into the end-contact, embedded-contact (top-contact), and side-contact (bottom-contact). Because of difficulties in the sample preparation, the end-contact CNT device is seldom practiced. The embedded-contact in which CNT is embedded inside the electrode is desirable due to its rigidness and the low contact resistance. Fabrication of this structure is complicated, however, because each CNT has to be located under a high-resolution microscope and then the electrode is patterned by electron beam lithography. The side-contact is done by depositing CNT electrophoretically or by precipitating on the patterned electrode. Although this contact is fragile and the contact resistance is relatively high, the side-contact by far has been widely practiced because of its simple fabrication process. Here we introduce a simple method to embed CNT inside the electrode while taking advantage of the bottom-contact process. The idea is to utilize a eutectic material as an electrode, which melts at low temperature so that CNT is not damaged while annealing to melt the electrode to embed CNT. The lowering of CNT/Au contact resistance upon annealing at mild temperature has been reported, but the electrode in these studies did not melt and CNT laid on the surface of electrode even after annealing. In our experiment, we used a eutectic Au/Al film that melts at 250$^{\circ}C$. After depositing CNT on the electrode made of an Au/Al thin film, we annealed the sample at 250$^{\circ}C$ in air to induce eutectic melting. As a result, Au-Al alloy grains formed, under which the CNT was embedded to produce a rigid and low resistance contact. The embedded CNT contact was as strong as to tolerate the ultrasonic agitation for 90 s and the current-voltage measurement indicated that the contact resistance was lowered by a factor of 4. By performing standard fabrication process on this CNT-deposited substrate to add another pair of electrodes bridged by CNT in perpendicular direction, we could fabricate a CNT cross junction. Finally, we could conclude that the eutectic alloy electrode is valid for CNT sensors by examine the detection of Au ion which is spontaneously reduced to CNT surface. The device sustatined strong washing process and maintained its detection ability.

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Differential Effect of Bovine Serum Albumin on Ginsenoside Metabolite-Induced Inhibition of ${\alpha}3{\beta}4$ Nicotinic Acetylcholine Receptor Expressed in Xenopus Oocytes

  • Lee, Jun-Ho;Jeong, Sang-Min;Lee, Byung-Hwan;Kim, Dong-Hyun;Kim, Jong-Hoon;Kim, Jai-Il;Lee, Sang-Mok;Nah, Seung-Yeol
    • Archives of Pharmacal Research
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    • v.26 no.10
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    • pp.868-873
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    • 2003
  • Ginsenosides, major active ingredients of Panax ginseng, that exhibit various pharmacological and physiological actions are transformed into compound K (CK) or M4 by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. Recent reports shows that ginsenosides might playa role as pro-drugs for these metabolites. In present study, we investigated the effect of bovine serum albumin (BSA), which is one of major binding proteins on various neurotransmitters, hormones, and other pharmacological agents, on ginsenoside $Rg_{2-}$, CK-, or M4-induced regulation of $\alpha3\beta4$ nicotinic acetylcholine (ACh) receptor channel activity expressed in Xenopus oocytes. In the absence of BSA, treatment of ACh elicited inward peak current ($I_{Ach}$) in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor. Co-treatment of ginsenoside $Rg_2$, CK, or M4 with ACh inhibited IAch in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. In the presence of 1% BSA, treatment of ACh still elicited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and co-treatment of ginsenoside $Rg_2$ or M4 but not CK with ACh inhibited $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor with reversible and dose-dependent manner. These results show that BSA interferes the action of CK rather than M4 on the inhibitory effect of $I_{Ach}$ in oocytes expressing $\alpha3\beta4$ nicotinic ACh receptor and further suggest that BSA exhibits a differential interaction on ginsenoside metabolites.

Effects of Fluoxetine on ATP-induced Calcium Signaling in PC12 Cells

  • Lee, Yeo-Min;Kim, Hee-Jung;Hong, Sun-Hwa;Kim, Myung-Jun;Min, Do-Sik;Rhie, Duck-Joo;Kim, Myung-Suk;Jo, Yang-Hyeok;Hahn, Sang-June;Yoon, Shin-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.1
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    • pp.57-63
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    • 2004
  • Fluoxetine, a widely used anti-depressant compound, has several additional effects, including blockade of voltage-gated ion channels. We examined whether fluoxetine affects ATP-induced calcium signaling in PC12 cells by using fura-2-based digital calcium imaging and assay for $[^3H]-inositol$ phosphates (IPs). Treatment with ATP $(100\;{\mu}M)$ for 2 min induced $[Ca^{2+}]_i$ increases. The ATP-induced $[Ca^{2+}]_i$ increases were significantly decreased by removal of extracellular $Ca^{2+}$ and treatment with the inhibitor of endoplasmic reticulum $Ca^{2+}$ ATPase thapsigargin $(1\;{\mu}M)$. Treatment with fluoxetine for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase concentration-dependently. Treatment with fluoxetine $(30\;{\mu}M)$ for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase following removal of extracellular $Ca^{2+}$ and depletion of intracellular $Ca^{2+}$ stores. While treatment with the L-type $Ca^{2+}$ channel antagonist nimodipine for 10 min inhibited the ATP-induced $[Ca^{2+}]_i$ increases significantly, treatment with fluoxetine alone blocked the ATP-induced responses. Treatment with fluoxetine also inhibited the 50 mM $K^+-induced$ $[Ca^{2+}]_i$ increases completely. However, treatment with fluoxetine did not inhibit the ATP-induced $[^3H]-IPs$ formation. Collectively, we conclude that fluoxetine inhibits ATP-indueed $[Ca^{2+}]_i$ increases in PC12 cells by inhibiting both an influx of extracellular $Ca^{2+}$ and a release of $Ca^{2+}$ from intracellular stores without affecting IPs formation.

Isolation of Protoplasts from Tomato Root by Two-step Osmotic Treatment (토마토 뿌리조직으로부터 두 단계 삼투압 처리에 의한 원형질체의 분리)

  • Shin, Dae-Seop;Han, Min-Woo;Kim, Young-Kee
    • Applied Biological Chemistry
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    • v.47 no.2
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    • pp.192-196
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    • 2004
  • In order to measure cellular physiological activity including ion channel activity, protoplasts were isolated from the root tissue of tomato plant. The general methods recommended were not efficient enough to make protoplasts from the root tissue. Among various conditions tested, we found that a two-step treatment of osmosis is very efficient for the isolation of protoplasts. In this procedure, root tissues were preincubated in a solution containing 300 mM sorbitol for 30 min. Then, they moved to the reaction solution containing 700 mM sorbitol as well as cell wall-digesting enzymes. The formation of protoplast was greatly increased by this method. In order to find the optimal condition of the two-step method, various conditions of pH, osmotic pressure, incubation time, and the concentrations of cell wall-digesting enzymes were tested. The yield of protoplast isolation was maximal at pH 5.0 after 2 hr incubation. Mixed enzymes of 3% cellulase, 1 % macerozyme, and 0.1 % pectolyase showed maximal protoplast isolation. The physiological activity of isolated protoplast evaluated by measuring the cellular ATPase activity was as high as that measured from the preparation of root tissue. The protoplasts isolated by this method were remained healthy up to 4 hrs which is enough time to measure the cellular physiological activity. These results show that the two-step treatment of osmotic pressure was successful to obtain high yield of healthy protoplast from tomato root tissue.

Glucocorticoid Regulation of Gene Expression in Hippocampal CA3 and Dentate Gyrus (글루코코티코이드 호르몬에 의한 뇌해마의 CA와 Dentate Gyrus 부분의 유전자 발현 변화)

  • Kim, Dong-Sub;Ahn, Soon-Cheol;Kim, Young-Jin;Park, Byoung-Keun;Ahn, Yong-Tae;Kim, Ji-Youn;Kyoji, Morita;Her, Song
    • Journal of Life Science
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    • v.17 no.3 s.83
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    • pp.305-311
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    • 2007
  • Glucocorticoids (GCs) alter metabolism, synaptogenesis, apoptosis, neurogenesis, and dendritic morphology in the hippocampus. To better understand how glucocorticoids regulate these aspects of hippocampal biology, we studied gene expression patterns in the CA3 (Hippocampal pyramidal cell field CA3) and dentate gyrus (DG). Litter-matched Lewis inbred rats treated for 20 days with either 9.5 mg per day sustained-release corticosterone or placebo pellets were compared with high-density oligonucleotide microarray analysis (Rat Neurobiology U34 Arrays, Affymetrix). In placebo-treated rats, 32 genes were expressed at greater levels in CA3 than DG, whereas 3 genes were expressed at great levels in DC than CA3. Regional differences were also apparent in corticosterone-induced changes in the hippocampal transcriptome. Six genes in CA3 and 41 genes in DC were differentially regulated by corticosterone. As per the glucocorticoid effects on gene transcription in the brain, forty three of these genes were upregulated, and 4 genes were downregulated. Genes differentially expressed in hippocampus included those for 13 neurotransmitter proteins, 5 ion channel related proteins, 4 transcription factors, 3 neurotrophic factors, 1 cytokine, 1 apoptosis related protein, and 5 genes involved in synaptogenesis. Interestingly, GCs can have suppressive effects on brain BDNF mRNA transcription, one of the neurotrophic factors. These results indicate the diversity of targets affected by chronic exposure to corticosterone and highlight important regional differences in hippocampal neurobiology.

Panax ginseng (Korea Red Ginseng) repairs diabetic sensorineural damage through promotion of the nerve growth factor pathway in diabetic zebrafish

  • Nam, Youn Hee;Moon, Hyo Won;Lee, Yeong Ro;Kim, Eun Young;Rodriguez, Isabel;Jeong, Seo Yule;Castaneda, Rodrigo;Park, Ji-Ho;Choung, Se-Young;Hong, Bin Na;Kang, Tong Ho
    • Journal of Ginseng Research
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    • v.43 no.2
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    • pp.272-281
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    • 2019
  • Background: Diabetic sensorineural damage is a complication of the sensory neural system, resulting from long-term hyperglycemia. Red ginseng (RG) has shown efficacy for treatment of various diseases, including diabetes mellitus; however, there is little research about its benefit for treating sensorineural damage. Therefore, we aim to evaluate RG efficacy in alloxan-induced diabetic neuromast (AIDN) zebrafish. Methods: In this study, we developed and validated an AIDN zebrafish model. To assess RG effectiveness, we observed morphological changes in live neuromast zebrafish. Also, zebrafish has been observed to have an ultrastructure of hair-cell cilia under scanning electron microscopy. Thus, we recorded these physiological traits to assess hair cell function. Finally, we confirmed that RG promoted neuromast recovery via nerve growth factor signaling pathway markers. Results: First, we established an AIDN zebrafish model. Using this model, we showed via live neuromast imaging that RG fostered recovery of sensorineural damage. Damaged hair cell cilia were recovered in AIDN zebrafish. Furthermore, RG rescued damaged hair cell function through cell membrane ion balance. Conclusion: Our data suggest that RG potentially facilitates recovery in AIDN zebrafish, and its mechanism seems to be promotion of the nerve growth factor pathway through increased expression of topomyosin receptor kinase A, transient receptor potential channel vanilloid subfamily type 1, and mitogen-activated protein kinase phosphorylation.