• Title/Summary/Keyword: 1L-5

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Toxicity Evaluation of Perfluorinated Compounds Using Daphnia magna (Daphnia magna를 이용한 과불화화합물의 독성평가)

  • Kim, Kyung-Tae;Cho, Jae-Gu;Yoon, Jun-Heon;Lee, Chul-Woo;Choi, Kyung-Hee;Kim, Hyun-Mi;Ryu, Ji-Sung
    • Environmental Analysis Health and Toxicology
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    • v.25 no.2
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    • pp.153-159
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    • 2010
  • Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the principal chemicals known as perfluoroalkyl acids (PFAs). Despite the widespread use of these compounds, relatively little is known about their fate and effects. The purpose of this study was to determine the toxic effects of PFOS and PFOA on Daphnia magna. In the acute toxicity test, D. magna were exposed for 48 hours at concentrations of 0, 30, 45, 67.5, 101.25 and 151.88 mg/L PFOS, and 0, 100, 160, 225, 337.5 and 506.25 mg/L PFOA, respectively. In the case of chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 0.375, 0.75, 1.5, 3 and 6 mg/L PFOS, and 0, 1.25, 2.5, 5, 10 and 20 mg/L PFOA, respectively. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on PFOS and PFOA showed that the values of $EC_{50}$ were 50.90 mg/L and 253.47 mg/L, respectively. In the chronic test, fecundity was reduced significantly at 1.5 mg/L of PFOS and 10 mg/L of PFOA, respectively. These results indicated that PFOS is more toxic to zooplankton than PFOA, and both chemicals have some hazard demonstrates risk for acute or chronic toxicity to freshwater organism.

Synthesis and Characterization of Various Di-N-Functionalized Tetraaza Macrocyclic Copper(II) Complexes

  • Kang, Shin-Geol;Kim, Na-Hee;Lee, Rae-Eun;Jeong, Jong-Hwa
    • Bulletin of the Korean Chemical Society
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    • v.28 no.10
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    • pp.1781-1786
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    • 2007
  • Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

Does the Access Angle Change the Risk of Approach-Related Complications in Minimally Invasive Lateral Lumbar Interbody Fusion? An MRI Study

  • Huang, Chunneng;Xu, Zhengkuan;Li, Fangcai;Chen, Qixin
    • Journal of Korean Neurosurgical Society
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    • v.61 no.6
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    • pp.707-715
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    • 2018
  • Objective : To investigate the potential risk of approach-related complications at different access angles in minimally invasive lateral lumbar interbody fusion. Methods : Eighty-six axial magnetic resonance images were obtained to analyze the risk of approach-related complications. The access corridor were simulated at different access angles and the potential risk of neurovascular structure injury was evaluated when the access corridor touching or overlapping the corresponding structures at each angle. Furthermore, the safe corridor length was measured when the corridor width was 18 and 22 mm. Results : When access angle was $0^{\circ}$, the potential risk of ipsilateral nerve roots injury was 54.7% at L4-L5. When access angle was $45^{\circ}$, the potential risk of abdominal aorta, contralateral nerve roots or central canal injury at L4-L5 was 79.1%, 74.4%, and 30.2%, respectively. The length of the 18 mm-wide access corridor was largest at $0^{\circ}$ and it could reach 44.5 mm at L3-L4 and 46.4 mm at L4-L5. While the length of the 22 mm-wide access corridor was 42.3 mm at L3-L4 and 44.1 mm at L4-L5 at $0^{\circ}$. Conclusion : Changes in the access angle would not only affect the ipsilateral neurovascular structures, but also might adversely influence the contralateral neural elements. It should be also noted to surgeons that alteration of the access angle changed the corridor length.

Synthesis and Dissociation Constants of Cationic Rhodium (I)-Triphenylarsine Complexes of Unsaturated Nitriles and Aldehyde

  • Chin, Chong-Shik;Park, Jeong-Han;Shin, Sang-Young;Kim, Choong-Il
    • Bulletin of the Korean Chemical Society
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    • v.8 no.3
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    • pp.179-183
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    • 1987
  • Reactions of $Rh(ClO_4)(CO)(AsPh_3)_2$ with unsaturated nitriles and aldehyde, L, produce a series of new cationic rhodium (I) complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ (L = $CH_2$ = CHCN, $CH_2$ = C($CH_3$)CN, trans-$CH_3CH$ = CHCN, $CH_2$ = CH$CH_2$CN, trans-$C_6H_5CH$ = CHCN, and trans-$C_6H_5CH$ = CHCHD) where L are coordinated through the nitrogen and oxygen, respectively but not through the ${\pi}$-system of the olefinic group. Dissociation constants for the reaction, $[RhL(CO)(AsPh_3)_2]ClO_4$ $\rightleftharpoons$ $Rh(ClO_4)(CO)(AsPh_3)_2$ + L, have been measured to be $1.20{\times}10^{-4}$ M (L = $CH_2$ = CHCN), $1.05{\times}10^{-4}$ M (L = $CH_2$ = C($CH_3$)CN, $3.26{\times}10^{-5}$ M (L = trans-$CH_3$CH = CHCN) and $6.45{\times}10^{-5}$ M (L = $CH_2$ = CH$CH_2$CN) in chlorobenzene at $25^{\circ}C, and higher than those of triphenylphosphine complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ where L are the corresponding nitriles that are coordinated through the nitrogen atom. The differences in dissociation constants seem to be predominantly due to the differences in ${\Delta}H$ (not due to the differences in ${\Delta}S$). The weaker Rh-N (unsaturated nitriles) bonding in $AsPh_3$ complexes than in $PPh_3$ complexes (based on ${\Delta}H$ values) suggests that the unsaturated nitriles in 2∼5 are good ${\sigma}$-donor and poor ${\pi}$-acceptor.

Optimization of Indole-3-acetic Acid (IAA) Production by Bacillus megaterium BM5

  • Lee, Jae-Chan;Whang, Kyung-Sook
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.461-468
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    • 2016
  • One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.

Evaluation of Dietary Supplementation with Hydrolyzed Blood Meal for Olive Flounder Paralichthys olivaceus, in Low Water Temperature Conditions (저수온기 넙치(Paralichthys olivaceus) 사료 내 가수분해 혈분(Hydrolyzed Blood Meal)의 이용성 평가)

  • Jongho Lim;Daehyun Ko;Whajung Cho;Kyeong-Jun Lee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.56 no.4
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    • pp.532-540
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    • 2023
  • This study aimed to evaluate the effects of dietary supplementation with two different types of hydrolyzed blood meal (HBM) on the growth performance, feed utilization, digestibility and innate immunity of olive flounder Paralichthys olivaceus. A control diet (Con) consisting of 60% fish meal was formulated and four diets containing two different types of HBM at varying concentrations were prepared 2.5 and 5.0% liquid HBM (L2.5 and L5.0) and 0.5 and 1.0% powdered HBM (P0.5 and P1.0). A total of 450 olive flounder (average body weight: 50±0.07 g) were distributed in 15 tanks (240 L), with three replicate groups per diet. The fish were fed the diets to apparent satiation for 9 weeks and subsequently exposed to Edwardsiella tarda. The results showed that fish fed L2.5, L5.0 and P0.5 diets exhibited significantly higher lysozyme activity compared to those fed the Con and P1.0 diets. During the challenge test against E. tarda, the L5.0 and P0.5 fish groups exhibited higher disease resistance than that of the Con group. These findings indicate that dietary supplementation with HBM could positively effect the innate immunity and disease resistance of olive flounder.

Effective Micropropagation of Pulsatilla cernua var. koreana through Apical Meristem Culture (할미꽃 정단 분열조직 배양을 통한 효율적 미세번식)

  • Ko, Jeong-Ae;Kim, Hyun-Soon
    • Korean Journal of Plant Resources
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    • v.21 no.5
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    • pp.362-367
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    • 2008
  • In order to investigate the effect of plant growth regulators on effective in vitro micropropagation, apical meristems of Pulsatilla cernua var. koreana were cultured on Murashige and Skoog's (MS) medium with 2,4-D, NAA, TDZ and BA. Media containing 2,4-D and kinetin, 2,4-D and TDZ, NAA and TDZ were not effective on callus induction. However, embryogenic or organogenic callus was obtained on media containing NAA and BA. Especially, on MS medium with 0.5mg/L NAA and 1.0mg/L BA was optimal for a high frequency (62%) of shoot or shoot bud obtained from callus. Callus proliferation, shoot multiplication and elongation were significantly increased by adding 10% coconut water on MS media with 0.5mg/L NAA and 1.0mg/L BA. Repeated subculturing of in vitro grown shoots resulted in propagation rate of 12.9 shoots per explant every 30 days. Root formation from the adventitious shoots was not easily achieved. However, roots were only produced through callus on MS medium with 2.0mg/L NAA alone or 0.5mg/L NAA and 1.0mg/L BA. These roots were used materials for callus and shoot production repetitively.

Layer-specific cholinergic modulation of synaptic transmission in layer 2/3 pyramidal neurons of rat visual cortex

  • Cho, Kwang-Hyun;Lee, Seul-Yi;Joo, Kayoung;Rhie, Duck-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.5
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    • pp.317-328
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    • 2019
  • It is known that top-down associative inputs terminate on distal apical dendrites in layer 1 while bottom-up sensory inputs terminate on perisomatic dendrites of layer 2/3 pyramidal neurons (L2/3 PyNs) in primary sensory cortex. Since studies on synaptic transmission in layer 1 are sparse, we investigated the basic properties and cholinergic modulation of synaptic transmission in layer 1 and compared them to those in perisomatic dendrites of L2/3 PyNs of rat primary visual cortex. Using extracellular stimulations of layer 1 and layer 4, we evoked excitatory postsynaptic current/potential in synapses in distal apical dendrites (L1-EPSC/L1-EPSP) and those in perisomatic dendrites (L4-EPSC/L4-EPSP), respectively. Kinetics of L1-EPSC was slower than that of L4-EPSC. L1-EPSC showed presynaptic depression while L4-EPSC was facilitating. In contrast, inhibitory postsynaptic currents showed similar paired-pulse ratio between layer 1 and layer 4 stimulations with depression only at 100 Hz. Cholinergic stimulation induced presynaptic depression by activating muscarinic receptors in excitatory and inhibitory synapses to similar extents in both inputs. However, nicotinic stimulation enhanced excitatory synaptic transmission by ~20% in L4-EPSC. Rectification index of AMPA receptors and AMPA/NMDA ratio were similar between synapses in distal apical and perisomatic dendrites. These results provide basic properties and cholinergic modulation of synaptic transmission between distal apical and perisomatic dendrites in L2/3 PyNs of the visual cortex, which might be important for controlling information processing balance depending on attentional state.

Antioxidative Activities of Extracts from Dried Citrus sunki and C. unshiu Peels (진귤 및 온주밀감 진피의 항산화 활성)

  • Hyon, Jae-Seok;Kang, Sung-Myung;Senevirathne, Mahinda;Koh, Won-Joon;Yang, Tai-Suk;Oh, Myung-Cheol;Oh, Chang-Kyung;Jeon, You-Jin;Kim, Soo-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.1
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    • pp.1-7
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    • 2010
  • This study was carried out to investigate total polyphenol contents, total flavonoid contents and antioxidative activities of the methanol extracts from dried Citrus sunki and C. unshiu peels. The dried C. sunki peels displayed higher total polyphenol and flavonoid contents for older dried peels. In contrast, the dried C. unshiu peels displayed higher total polyphenol contents for more recently dried and displayed high total flavonoid contents by order of 2007, 2008 and 2006. DPPH radical scavenging activities of dried C. sunki peels were high by order of 2007 (0.25 mg/mL exception), 2006 and 2008, but C. unshiu peels could not confirm clear regularity. In particular, the dried C. sunki (2008, exception) and C. unshiu peels displayed very high activities of more than 86% in 1.0 mg/mL. Alkyl radical scavenging activities of dried C. sunki peels were higher for older dried peels (2007, 1.0 mg/mL exception), and that of dried C. unshiu peels were higher for more recently dried in below 0.5 mg/mL but were higher for older peels in 1.0 mg/mL. Hydrogen peroxide scavenging activities of dried C. sunki peels were higher for older peels (2007, 2.5 mg/mL exception), on the other hand, dried C. unshiu were higher for more recently dried. In particular, dried C. unshiu peels displayed high activities of more than 85% in 2.5 mg/mL. Hydroxyl radical scavenging activities of dried C. sunki and C. unshiu peels displayed low activities compared to other reactive oxygen species as the range of $49.9\pm2.2\sim63.5\pm0.9$% in 1.0 mg/mL.

Physiological Activities of Fermented Gastrodia elata Blume Extracts (발효 천마 추출물의 생리 활성)

  • Park, An Na;Ku, Tae Kyu;Kim, Kyung Sun;Lee, Dong Won;Kim, Sang Jin
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.702-711
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    • 2015
  • This study was conducted to determine the feasibility of using Gastrodia elata Blume as a cosmetic raw material by investigating the physiological activities of its extracts, varying the concentration, solvent, and fermentation method (non-fermentation and fermentation using lactic acid bacteria and effective microorganisms). Of the extracts in three different solvents-water, EtOH, and 70% EtOH-at four different concentrations (0.725, 1.25, 2.5, and 5 mg/mL), the EtOH extracts demonstrated the highest contents of antioxidants (flavonoids, polyphenols, and DPPH free radical scavengers). The DPPH free radical scavenging activity in the EtOH extracts of EM-fermented Gastrodia elata Blume increased from $27.08{\pm}0.5%$ at 1.25 mg/mL to $35.89{\pm}0.8%$ at 2.5 mg/mL. The tyrosinase inhibitory activity test was performed to measure skin-whitening capacity and revealed the LB-fermented EtOH extracts to be the most efficacious ($39.1{\pm}0.4%$ at 0.725 mg/mL, $62.8{\pm}1.5%$ at 2.5 mg/mL). Viability was found to exceed 85% in RAW 264.7 cells treated with all extracts (water, EtOH, 70% EtOH at 10, 25, $50{\mu}L$, fermented and non-fermented), thus proving that Gastrodia elata Blume extracts do not cause inflammation. When RAW 264.7 cells were stimulated with lipopolysaccharide as positive controls under the same conditions to determine the antioxidant activity in the presence of reactive oxygen species (ROS), EM-fermentation was found to impart excellent antioxidant capacity. This study verified the physiological activities of fermented Gastrodia elata Blume extracts that are best suited for cosmetic ingredients, such as antioxidants, tyrosinase inhibitors and anti-inflammatory agents.