• Title/Summary/Keyword: blocking reagent

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The Development of UV Blocking Type Pressure-Sensitive Adhesive Sheet for Window (자외선이 차단되는 창문용 점착시트 개발에 관한 연구)

  • Kim, Sung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.559-564
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    • 2011
  • The UV blocking type pressure-sensitive adhesive sheet was developed by mixing UV blocking reagent with adhesive material, instead of conventional method in which the reagent was mixed with PVC substrate. The blocking performance of the sheet was evaluated by measuring the absorbance in 280-400 nm region. Both organic and inorganic type blocking reagents were examined. The blocking ability of the former is better than that of the later. Only 1% addition of blocking reagents is effective to block UV light without affecting to visibility and tackiness of adhesive tapes.

Chemical Modification of the Human Ether-a-go-go-related gene (HERG) $K^+$ Current by the Amino-Group Reagent Trinitrobenzene Sulfonic Acid

  • Jo Su-Hyun;Choi Se-Young;Yun Ji-Hyun;Koh Young-Sang;Ho Won-Kyung;Lee Chin-O.
    • Archives of Pharmacal Research
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    • v.29 no.4
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    • pp.310-317
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    • 2006
  • We investigated the effects of trinitrobenzene sulfonic acid (TNBS), an amino-group reagent, on the human ether-a-go-go-related gene (HERG) $K^+$ channels expressed in Xenopus oocytes. TNBS neutralizes the positively charged amino-groups of peptide N-terminal and lysine residues. External application of TNBS at 10 mM for 5 min irreversibly shifted the curves for currents at the end of the pulse and tail currents of HERG to a more negative potential and decreased the maximal amplitude of the $I_{tail}$ curve $(I_{tail,max})$. TNBS had little effect on either the activated current-voltage relationship or the reversal potential of HERG current, indicating that TNBS did not change ion selectivity properties. TNBS shifted the time constant curves of both activation and deactivation of the HERG current to a more hyperpolarized potential; TNBS's effect was greater on channel opening than channel closing. External $H^+$ is known to inhibit HERG current by shifting $V_{1/2}$ to the right and decreasing $I_{tail,max}$. TNBS enhanced the blockade of external $H^+$ by exaggerating the effect of $H^+$ on $I_{tail,max}$, not on $V_{1/2}$. Our data provide evidence for the presence of essential amino-groups that are associated with the normal functioning of the HERG channel and evidence that these groups modify the blocking effect of external $H^+$ on the current.

Novel Approach of a Phage-Based Magnetoelastic Biosensor for the Detection of Salmonella enterica serovar Typhimurium in Soil

  • Park, Mi-Kyung;Chin, Bryan A.
    • Journal of Microbiology and Biotechnology
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    • v.26 no.12
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    • pp.2051-2059
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    • 2016
  • To date, there has been no employment of a magnetoelastic (ME) biosensor method to detect Salmonella enterica serovar Typhimurium in soil. The ME biosensor method needs to be investigated and modified for its successful performance. The filtration method, cation-exchange resin method, and combinations of both methods were employed for the extraction of S. Typhimurium from soil. The number of S. Typhimurium and the resonant frequency shift of the ME sensor were then compared using a brilliant green sulfa agar plate and an HP 8751A network analyzer. A blocking study was performed using bovine serum albumin (BSA), polyethylene glycol (PEG), and casein powder suspension. Finally, the modified ME biosensor method was performed to detect S. Typhimurium in soil. The number of S. Typhimurium was significantly decreased from 7.10 log CFU/soil to 4.45-4.72 log CFU/soil after introduction of the cation-exchange resin method. The greatest resonant frequency shift of the measurement sensor was found when employing centrifugation and filtration procedures. The resonant frequency shift of the PEG-blocked measurement sensor was $3,219{\pm}755Hz$, which was significantly greater than those of the BSA- and casein-blocked ME sensor. The optimum concentration of PEG was determined to be 1.0 mg/ml after considering the resonant shift and economic issue. Finally, the modified ME biosensor method was able to detect S. Typhimurium in soil in a dose-response manner. Although these modifications of the ME biosensor method sacrificed some advantages, such as cost, time effectiveness, and operator friendliness, this study demonstrated a novel approach of the ME biosensor method to detect S. Typhimurium in soil.

The Effect of Indole Acetic and Abscisic Acid on Ribonucleic Acid and Ribonuclease (Indole acetic acid 와 Abscisic acid 가 핵산(核酸)과 RNase 에 미치는 영향에 관(關)하여)

  • Jo, D.H.;Lee, C.Y.
    • Applied Biological Chemistry
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    • v.15 no.3
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    • pp.181-186
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    • 1972
  • Wheat coleoptile sections were treated with either $1.5{\times}10^{-5}M$ ABA or $5×10^{-5}M$ IAA in vitro, the results may be summarized as follows, 1. The treatmert of IAA decreased the level of high molecular weight RNA F2 and F3 but that with ABA increased the F4 level. 2. IAA caused an increased activity of G2 isozyme, while ABA suppressed the activity of G3 isozyme. 3. The results may suggest that there may exist common effects of IAA and ABA on RNA and RNase. 4. The latent RNase activity caused by SH blocking reagent (p-hydroxymercury benzoate, Pb et al) was not observed.

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Relaxation Effects of Eucomiae Cortex in Isolated Rabbit Corpus Cavernosum Smooth Muscle (杜冲의 토끼 음경해면체 평활근 이완효과)

  • Park, Sun Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.29 no.6
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    • pp.485-491
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    • 2015
  • This study was aimed to investigate the relaxation effects of Eucomiae Cortex (EC) extract in isolated rabbit corpus cavernosum smooth muscle and its mechanism. To evaluate the relaxation of EC extract in rabbit corpus cavernosum, EC extract was treated in corporal strips which were precontracted with phenylephrine(PE). To study its mechanism, Nω-nitro-L-arginine (L-NNA) was pretreated after infuse of EC extract and compared with non-treated. In calcium chloride (Ca2+) -free krebs solution, EC extract and Ca2+ 1 mM were infused by turns after Ca2+ 1 mM was treated into corporal strips contracted by PE. Cell ability, nitric oxide (NO) and epithelial nitric oxide synthase (eNOS) on human umbilical vein endothelial cell (HUVEC) were measured by MTT assay, Griess reagent system and histochemical, immunohistochemical methods. EC extract showed a significant relaxation effects on the corporal strips, this effects were inhibited by pretreatment of L-NNA. EC extract inhibited the increase of contraction by Ca2+ influx in Ca2+-free krebs solution, and eNOS positive reaction in corpus cavernosum, NO production in HUVEC increased by treatment of EC extract. These result suggest that the relaxation effects of EC extract in isolated corpus cavernosum smooth muscle are involved in increase of eNOS and NO production, blocking of extracellular Ca2+ influx.

Formation and Structure of Self-Assembled Monolayers of Octylthioacetates on Au(111) in Catalytic Tetrabutylammonium Cyanide Solution

  • Park, Tae-Sung;Kang, Hun-Gu;Choi, In-Chang;Chung, Hoe-Il;Ito, Eisuke;Hara, Masahiko;Noh, Jae-Geun
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.441-444
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    • 2009
  • The formation and structure of self-assembled monolayers (SAMs) by the adsorption of acetyl-protected octylthioacetate (OTA) on Au(111) in a catalytic tetrabutylammonium cyanide (TBACN) solution were examined by means of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). Molecular-scale STM imaging revealed that OTA molecules on Au(111) in a pure solvent form disordered SAMs, whereas they form well-ordered SAMs showing a c(4 × 2) structure in a catalytic TBACN solution. XPS and CV measurements also revealed that OTA SAMs on Au(111) formed in a TBACN solution have a stronger chemisorbed peak in the S 2p region at 162 eV and a higher blocking effect compared to OTA SAMs formed in a pure solvent. In this study, we clearly demonstrate that TBACN can be used as an effective deprotecting reagent for obtaining well-ordered SAMs of thioacetyl-protected molecules on gold.

Inactivation of Brain GABA transaminase by p$^1$, p$^2$-Bis(5′-pyridoxal) diphosphate

  • Jang, S.H.;Lee, B.R.;J.W. Hong;Park, K.W.;Yoo, B.K.;Cho, S.W.;Park, S.Y.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.74-74
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    • 1995
  • GABA transaminase is inactivated by preincubation with p$^1$, p$^2$-bis(5'-pyridoxal) diphosphate at pH 7.0. The inactivation under pseudo-first order conditions proceeds at a slow rate (K$\_$obs/=0.035 min$\^$-1/). The degree of labeling of the enzyme by p$^1$, p$^2$-bis(5'-pyridoxal) diphosphate was determined by absorption spectroscopy, The blocking of 2 lysyl residues/dimer is needed for inactivation of the transaminase. The time course of the reaction is significantly affected by the substrate ${\alpha}$-ketoglutarate, which afforded complete protection against the loss of the catalytic activity. Whereas cofator pyridoxal phosphate failed to prevent the inactivation of the enzyme. Therefore, it is postulated that binding of ${\alpha}$-ketoglutarate tn lysyl residues is the major factor contributing to stabilization of the catalytic site and bifuctional reagent p$^1$, p$^2$bis(5'-pyridoxal) diphosphate blocks lysyl residues other than those involved in the binding of the cofactor.

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The Endothelium-Dependent Vasorelaxation Effect of Cynomorii Herba (쇄양(鎖陽)의 내피세포 의존성 혈관이완효과)

  • Park, Sun-Young
    • The Korea Journal of Herbology
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    • v.30 no.6
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    • pp.25-32
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    • 2015
  • Objectives : The purpose of this study was to investigate the endothelium-dependent vasorelaxation effect of Cynomorii Herba(CH) extract on contracted rabbit carotid artery.Methods : To clarify the vasorelaxation effect of CH extract, arterial strips with intact was used, to endothelium -dependent vasorelaxation effect of CH extract, arterial strips damaged endothelium was used for experiment using organ bath. Arterial strips was contracted with phenylephrine(PE) before treated with CH extract(0.01, 0.03 and 0.1 ㎎/㎖). To study mechanisms of CH-induced vasorelaxation effect, CH extract infused into arterial rings after treatment by indomethacin(IM), tetraethylammonium chloride(TEA), Nω-nitro-L-arginine (L-NNA), methylene blue(MB) for comparing with non-treated. And calcium chloride(Ca2+) 1 mM was treated into precontracted arterial ring induced by PE after treatment of CH extract in Ca2+-free krebs solution. Cytotoxic activity of CH extract on human umbilical vein endothelial cell(HUVEC) was measured by MTT assay, and nitric oxide(NO) concentration was measured by Griess reagent.Results : PE-induced arterial strips was significantly relaxed, but the damaged endothelium arterial ring wasn't relaxed by CH extract. Pretreatment of IM, TEA didn't inhibit the vasorelaxation of CH extract, but pretreatment of L-NNA, MB inhibited the vasorelaxation of CH extract. Pretreatment of CH extract reduced the increase of contraction by influx of extracellular Ca2+ in contracted arterial ring induced by PE, CH extract increased nitric oxide concentration on HUVEC significantly.Conclusions : This study shows that CH extract have the vasorelaxation effect by blocking the influx of extracellular Ca2+ through the activating NO-cGMP system.

Inhibition of LPS-induced Inflammatory Biomarkers by Fraction of Citrus hassaku pericarp through Suppression of NF-${\kappa}B$ Activation in RAW264.7 Cells (재래감귤 팔삭의 과피 추출물이 LPS로 활성화 된 RAW264.7 대식세포에서 염증매개물질 억제에 미치는 효과)

  • Kim, Chul-Won;Kim, Sung-Moo;Jeong, Seung-Weon;K., So-Mi Cho;Ahn, Kwang-Seok
    • Journal of Korean Traditional Oncology
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    • v.16 no.2
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    • pp.25-34
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    • 2011
  • Objectives : Citrus is the fruit that is readily available around us. Therefore, we investigated the anti-inflammatory effects of fraction isolated from the Citrus hassaku pericarp in RAW264.7 macrophage cells. Methods : The effects of fraction from Citrus hassaku pericarp on cell viability on RAW264.7 cells were measured by the MTT assay. The mRNA levels of iNOS and COX-2, its protein level by fraction of Citrus hassaku pericarp treatment in RAW264.7 macrophage cells were investigated by RT-PCR and immunoblots. Nitrite accumulation in the culture was measured colorimetrically by the Griess reaction using a Griess reagent. The amount of IL-6 and TNF-${\alpha}$ production was determined using an enzyme-linked immunosorbent assay (ELISA) kit. Results : The results indicated that the fraction of Citrus hassaku pericarp concentration highly suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) and IL-6 productions without a cytotoxic effect on RAW264.7 cells. fraction of Citrus hassaku pericarp inhibited the expressions of LPS-induced iNOS and COX-2 protein and their mRNA in a dose-dependent manner. Particularly, fraction of Citrus hassaku pericarp suppressed the level of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity, which was linked with the suppression of LPS-induced phosphorylation of p65 at serine 276 and p65 translocation into nuclei, but not MAPK signaling. In addition, treatment with fraction of Citrus hassaku pericarp inhibited the production of IL-6 and TNF-${\alpha}$ in LPS-stimulated RAW264.7 cells. Conclusion : Our results indicate that fraction of Citrus hassaku pericarp potentially inhibits the biomarkers related to inflammation through the blocking of NF-${\kappa}B$ p65 activation, and it may be a potential therapeutic candidate for the treatment of inflammatory diseases.

The Antioxidant Activities and Hair-growth Promotion Effects of Tenebrio molitor Larvae Extracts (TMEs) (갈색거저리 유충 추출물의 항산화 활성 및 모발 성장 촉진 효과)

  • Baek, Minhee;Seo, Minchul;Kim, Mi-Ae;Yun, Eun-Young;Hwang, Jae-Sam
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1269-1275
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    • 2017
  • Tenebrio molitor samples were investigated as novel biomaterials and sources of food in several recent studies. However, the insects' effects on hair growth were not sufficiently researched. To develop novel and natural materials for preventing alopecia and promoting hair growth, this study investigated the antioxidant activities and hair-growth promotion effects of TMEs. To determine the antioxidant activities, the TMEs' DPPH radical- and nitrite-scavenging activities were examined. To determine hair-growth promotion effects, proliferations of human dermal papilla cells (DPCs) and the murine fibroblast cell line NIH3T3 were evaluated by using an MTS assay. In addition, estimations were made for cell viabilities against cell death induced by dihydrotesterone (DHT) in DPCs and inhibitory effects against potassium channel blocking induced by tolbutamide (TBM) in NIH3T3 cells. The DPPH radical scavenging activity was 81.17%, and the nitrite scavenging activity was 43.69%; the activities were similar to the activities of blueberry extracts. Moreover, the TMEs promoted the proliferation of human DPCs and NIH3T3 cells, which were concentrated dependently. The TMEs prevented not only DHT-induced DPC cytotoxicity but also TBM's action as a potassium channel blocker in NIH3T3 cells. The results suggested that TME could be used as a functional therapeutic alopecia reagent, to prevent hair loss and to promote hair growth.