• The Korean Journal of Physiology and Pharmacology
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• v.27 no.6
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• pp.521-531
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• 2023

Transmembrane protein TMEM16A, which encodes calcium-activated chloride channel has been implicated in tumorigenesis. Overexpression of TMEM16A is associated with poor prognosis and low overall survival in multiple cancers including lung adenocarcinoma, making it a promising biomarker and therapeutic target. In this study, three structure-related sesquiterpene lactones (mecheliolide, costunolide and dehydrocostus lactone) were extracted from the traditional Chinese medicine Aucklandiae Radix and identified as novel TMEM16A inhibitors with comparable inhibitory effects. Their effects on the proliferation and migration of lung adenocarcinoma cells were examined. Whole-cell patch clamp experiments showed that these sesquiterpene lactones potently inhibited recombinant TMEM16A currents in a concentration-dependent manner. The half-maximal concentration (IC50) values for three tested sesquiterpene lactones were 29.9 ± 1.1 µM, 19.7 ± 0.4 µM, and 24.5 ± 2.1 µM, while the maximal effect (E_max) values were 100.0% ± 2.8%, 85.8% ± 0.9%, and 88.3% ± 4.6%, respectively. These sesquiterpene lactones also significantly inhibited the endogenous TMEM16A currents and proliferation, and migration of LA795 lung cancer cells. These results demonstrate that mecheliolide, costunolide and dehydrocostus lactone are novel TMEM16A inhibitors and potential candidates for lung adenocarcinoma therapy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.511-522
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• 1984

The Nagdong is one of the biggest rivers in Korea, which is very important water source not only for tap water of Pusan city but also for the industrial water. Therefore, authors tried to check the water quality year by year. In this experiment one hundred and twenty water samples collected from August 1983 to July 1984 were analyzed bacteriologically and physiologically. Fifteen sampling stations were established between near Samrangjin and estuary of the river. To evaluate the water quality, temperature, pH, chloride ion, salinity, chemical oxygen demand (COD), electrical conductivity, nutrients, total coliform, fecal coliform, fecal streptococcus, viable cell count and bacterial flora were observed. The variation of water temperature was ranged $-1.5{\sim}29.0^{\circ}C$ (Mean value $13.9{\sim}16.5^{\circ}C$), it in spring was higher as $10{\sim}15^{\circ}C$ about $10^{\circ}C$ than in winter and it in autumm was very stabilized as about $20^{\circ}C$ at each station. The pH variation of the samples was ranged $6.68{\sim}9.15$. The range of concentration of chloride ion and salinity varied $7.4{\sim}l,020.5$ mg/l and $1.05{\sim}33.0\%0$, respectively. Especially, salinity of the 3rd water war was the higher than others as $25.76{\sim}31.58\%0$. COD was ranged $1.45{\sim}14.94$ mg/l and the lower part of the Nagdong River was heavily contaminated by domesitc sewage and waste water from the adjacent factor area. The range of electrical conductivity was $1.360{\times}10^2{\sim}5.650{\times}10^4{\mu}{\mho}/cm$ and that was by far higher the estuary than the upper. Concentration of nutrients were $0.008{\sim}0.040$ mg/l (Mean value $0.019{\sim}0.068$ mg/l) for $NO_2-N,\;0.038{\sim}5.253$ mg/l ($0.351{\sim}2.347$ mg/l) for $NO_3-N,\;0.100{\sim}2.685$ mg/l($0.117{\sim}1.380$ mg/l) for $NH_4-N,\;0.003{\sim}0.084$ mg/l($0.014{\sim}0.065$ mg/l) for $PO_4-P$ and $0.154{\sim}6.123$ mg/l ($1.165{\sim}3.972$ mg/l) for $SiO_2-Si$, respectively. Usually nutrients contents of the water in the upper part(included station 1 to 5) were higher than those of the estuarine area. The bacterial density of the samples ranged 7.3 to 460,000/100 ml for total coliforms, 3.6 to 460,000/100 ml for fecal coliform, $0{\sim}46,000/100ml$ for fecal streptococcus and $<30{\sim}1.2{\times}10^5/ml$ for viable cell count. Composition of coliform was $28\%$ Escherichia coli group, $18\%$ Citrobacter freundii group, $31\%$ Enterobacter aerogenes group and $22\%$ others. Predominant species among the 659 strains isolated from the samples were Pseudomonas spp. ($42\%$), Flavobacterium spp. ($20\%$) and Moraxella spp. ($12\%$).

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.75-90
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• 2003

Ettringite and thaumasite were observed in some concrete. The morphology and occurrence of these minerals were closely examined by performing SEM/EDAX analyses. We also experimentally induced the concrete deterioration using $Na_2SO_4$ solution with application of various environmental conditions. The stability of these minerals and deterioration characteristics under applied experimental conditions were determined. Abundant ettringite formed by“through solution reaction”occurred in many open spaces, and some microscopic ettringite formed by "tophochemical replacement" of calcium aluminate also occurred in cement paste. Severe cracking of cement paste causing premature deterioration was often associated with ettringite location. Under specific condition, ettringite was transformed to thaumasite, tricthloroaluminate, or decomposed. Thaumasite occurred with association of ettrinsite in concrete containing carbonate aggregate being subject to dedolomitization or in some concrete being subject to carbonation. Thaumasite appears to be formed under the similar condition to the general ettringite forming condition, but it formed solid solution with ettringite by substituting pre-existing ettringite. Ettringite can also be transformed to trichloroaluminate in the presence of abundant chlorides, but trichloroaluminate changed back to ettringite in late sulfate attack. It is considered that the substitution reaction direction solely depend on the concentration of chloride and sulfate ion.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1003-1012
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• 2007

In this study, we analyzed the release differences for some critical pollution compounds according to the surrounding conditions in order to predict water quality due to the sedimental releases and the release characteristics at different sedimental locations in Lake Leewon, in Tae-An area. COD, nitrogens and phosphates were analyzed using the standard methods for water quality, based on high chloride ion concentration(greater than 2,000 ppm). For COD, the release rate increased in the anoxic basin but almost the same in the oxic basin. For $NH_3$-N, the release rate decreased in the oxic basin as you go A through C point meanwhile, for $NO_3$-N and T-N, the tendency was reversed because of nitrification of them. In the anoxic basin, the release rates of $NH_3$-N and $NO_3$-N went up with A through C path. However, the release rate of T-N was found to decrease. Also, for $PO_4$-P and T-P, the release rates in the oxic basin were lowest at B point mainly because the phosphates were at less released in the highly $O_2$ concentrated environment. In the anoxic reactor, $PO_4$-P was released similarly regardless of the sampling points. In summary, the release rates in the oxic reactor were greater than those in the anoxic reactor for COD and $NO_3$-N. For the other components, the anoxic basin generated the higher release rates.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.313-318
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• 2010

Deinococcus radiodurans RecA protein, when bound to DNA, exhibits a DNA-dependent ATPase. In the absence of DNA, the rate of RecA protein-promoted ATP hydrolysis drops 1,000-fold under the physiological concentrations of salt. This DNA-independent activity can be stimulated to levels approximating those observed with DNA by adding high concentrations (approximately 1.6 M) of a wide variety of salts. This effect was characterized by varying salt concentration and comparing the effects of different ion types. The higher concentrations of salt stimulated the ATP hydrolysis by RecA protein in the absence of DNA. At 1.6 M chloride, the observed stimulation showed the following cation trend $K^+{\geq}Na^+$ > $NH_4^+$ and the following anion sequence was observed: $glutamate^- \; > \; C1^- \;> \; acetate^-\; > \;PO_4^-$ at 1.6 M $K^+$. The catalytic properties of the salt-stimulated ATP hydrolysis reaction was optimal between pH 7.0 and 8.0, which was similar to the double stran nded DNA-dependent ATPase activities of Deinococcus radiodurans RecA protein. In the absence of DNA the active species for ATP hydrolysis by RecA protein was shown to be an aggregate of three RecA protein molecules.

• Journal of Conservation Science
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• v.29 no.4
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• pp.297-309
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• 2013

Iron objects become corroded at fast speed from the moment when they are excavated, so it is needed to control corrosion through processes of conservation treatment. However, re-corrosion mostly takes place in excavate iron objects, although they have already gone through the process of conservation treatment, and it is more difficult to carry out the second conservation treatment of re-corroded excavated iron objects than the first conservation treatment, and it requires a longer period of time to treat them as well. In this study, aims to discover factors of re-corrosion by scientifically analyzing corrosion products generated during the process of storage after the process of conservation treatment. The finished on conservation treatment of the iron artifacts, which were unearthed from three ancient site in Gyeongju by using the same conservation method between 2002 and 2009, re-corrosion condition observed on the packaging-iron artifacts. Focused on 9 target forged iron artifacts among them, this study analyzed the physical changes by mass measurement, naked-eye and microscopic observations and the chemical changes by SEM-EDS, XRD, IC and ICP analysis. The results show that the yellowish brown corrosion products formed on the facing surface of part dropped from the artifacts had different associated forms but acicular shape. In addition, the acicular shape became clearer as the color changed from red to yellowish brown. According to the process when the conservation treatment was completed, the mass of the artifacts increased in proportion to the corrosion products and the chloride ion ($Cl^-$) concentration had a tendency to increase relatively. ${\beta}$-FeOOH (akaganeite) was confirmed in the XRD analysis for the corrosion products of all the collected samples. As a result of ICP analysis, $Na^+$ and $Ca^{2+}$ components were confirmed.

• Resources Recycling
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• v.29 no.5
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• pp.55-63
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• 2020

In order to investigate the separation of Co(II) and Ni(II) by ionic liquids from weak hydrochloric acid solutions, extraction experiments were performed by changing the type and concentration of ionic liquids and the initial pH of the aqueous phase. Two kinds of ionic liquids based on Aliquat 336 were employed in this work; one was synthesized by reacting organophosphorus acids(D2EHPA, PC88A, Cyanex 272, Cyanex 301) with Aliquat 336 and the other was prepared by exchanging the chloride ion of Aliquat 336 with SCN^-. The three types of ionic liquids (ALi-D2, ALi-PC, and ALi-CY272) showed better extraction of Co(II) than Ni(II), and the equilibrium pH was higher than the initial pH. In the case of ALi-CY301, the selectivity of Co(II) and Ni(II) depended on the extraction conditions. In addition, the effect of the addition of TBP to the ionic liquid on the extraction of two metals was also investigated. Employment of ALi-SCN as an extractant resulted in selective extraction of Co(II) and complete separation of the two metal ions was possible.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.35-40
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• 2002

Purpose : To evaluate the NMR relaxation properties and imaging characteristics of tissue-specificity for a newly developed macromolecular MR agent. Materials and methods : Phthalocyanine (PC) was chelated with paramagnetic ion, Mn.2.01g (5.2 mmol) of Phthalocyanine was mixed with 0.37g (1.4 mmol) of Mn chloride at $310^{\circ}C$ for 36 hours and then purified by chromatography (CHC13/CH3OH 98/2 v/v, Rf, 0.76) to obtain 1.04g (46%) of MnPC (molecular weight= 2000d). The $T1}T2$ relaxivity of MnPC was measured in 1.5T(64 MHz) MR using 0.1 mM MnPC. The MR image characteristics of MnPC was evaluated using spin-echo (TR/TE=500/14 msec) and gradient-echo (FLASH) (TR/TE=80/4 msec, flip angle=60) techniques in 1.57 MR scanner. The images of rabbit liver were obtained every 10 minutes up to 4 hours. To study the effect of concentration on image, 20 mM, 50 mM, 100 mM of MnPC were tested. Results : The relaxivities of MnPC at 1.5T(64MHz) were Rl=7.28 $mM^{-1}S^{-1},{\;}R2=55.56mM^{-1}S^{-1}$. Compared to the values of Gd-DTPA (Rl[=4.8 $mM^{-1}S^{-1})$], R2[=5.2 $mM^{-1}S^{-1}])$]), both T1/T2 relaxivities of MnPC were higher than those of Gd-DTPA. For both of SE and FLASH techniques, the contrast enhancement reached maximum at 10 minutes after bolus injection and the enhancement continued for more than 2 hours. When compared with small molecular weight liver agents such as Gd-EOB-DTPA, Gd-BOPTA and MnDPDP, MnPC was characterized by more prolonged enhancement time. The time course of MR images also revealed biliary excretion of MnPC. Conclusion : We developed a new macromolecular MR agent, MnPC. The relaxivities of MnPC were higher than those of small molecular weight Gd-chelate. Hepatic uptake and biliary excretion of MnPC suggests that this agent is a new liver-specific MR agent.

• The Korean Journal of Nuclear Medicine
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• v.35 no.5
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• pp.334-341
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• 2001

Purpose: Ascorbic acid us known to act as an antioxidant. Therefore, it can be used in increasing the efficiency of radiochemical labeling of Technetium-99m setamibi by inhibition of oxidation of $Sn^{2+}$ at low concentration. We intended to estimate the efficiency of radiochemical labeling and the stability of the newly formed formulation when ascorbic acid was added to a commercial kit. Materials and Methods: Synthesis of sestamibi was performed according to Dong-A's patent procedure (No.10-2001-0012877). First, we undertook a study to evaluate the efficiency of radiochemical labeling of sestamibi containing ascorbic acid. The stability of the vials was assessed using either $7.5{\mu}g\;or\;75{\mu}g$ of ascorbic acid, added to commercial vials under the accelerated condition(Temp : $40^{\circ}C{\pm}2^{\circ}C$, Relative humidity : $75{\pm}5%$). Results: Sestamibi was synthesized in overall 35-40% yield over 5 steps from a commercially available methallyl chloride as a starling material. When ascorbic acid was added, the efficiency of radiochemical labeling was maintained compared to the vial with no ascorbic acid. The accelerated test showed that the addition of ascorbic acid inhibited the oxidation of $Sn^{2+}$ ion by antioxidation mechanism. Also, the efficiency of radiochemical labeling of this vial after 9 months was nearly the same as the starting point. Therefore, the storage period of the kit is likely to be extended. Taken together, it suggests that the addition of ascorbic acid as a stabilizer is desirable. Conclusion: To increase the stability of a sestamibi cold kit, it is desirable to add ascorbic acid as a stabilizer to the commercial formulation.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.398-403
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• 1978

Squid was dried on the fluidized-bed in the drying chamber filled with solid particles which were also fluidized with hot-air, and effects of the fluidized particles, the squid's height from the grid and the drying temperature on the drying rate and quality of the squid were observed The mechanism of moisture transfer during the falling rate period was also derived. 1. Sodium chloride was found to be the most suitable fluidized particles and at an air velocity of 3.8 m/sec, optimal fluidization state of this particle was obtained. 2. Uniform profiles of temperature were obtained at a point 4 cm above the grid and the location of squid on the fluidized-bed observed to be suitable when it was 4 cm above the grid. 3. At an air velocity of 3.8 m/sec and when the location height of the squid on the fluidized-bed was 4 cm, the optimal temperature for the drying time which is required to reduce the moisture from 80.8% to 18-22% was 8.5 hours. 4. Drying data followed the empirical equation of unsteady state diffusion $log\;(\frac{W-We}{Wc-We})=-m{\theta}$ in the region of the moisture contents measured and the drying constant (m) was calculated as $0.32hr^{-1}$. These results suggested that the migration of moisture during the falling rate period is due to a diffusion type mechanism. 5. The short constant rate period was observed in the early stage and thereafter, drying was controlled by the falling rate period, and the time ratio of the fluidized bed drying to the through circulation drying for reducing the squid's moisture contents to the same level at the same drying temperature was 1 : 1.4 6. Comparisons of fluidized-bed dried squid and sun dried squid in sale showed that there was no significant change in qualities such as external appearance and hydrogen ion concentration of dry product.