• Title/Summary/Keyword: induced current

Search Result 2,693, Processing Time 0.038 seconds

A study on the effect of the pile tip deformations on the pile behaviour to shield TBM tunnelling (Shield TBM 터널시공으로 유발된 말뚝선단의 변형이 말뚝거동에 미치는 영향에 대한 연구)

  • Young-Jin Jeon;Byung-Soo Park;Young-Nam Choi;Cheol-Ju Lee
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.26 no.3
    • /
    • pp.169-189
    • /
    • 2024
  • In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of pre-existing single piles and pile groups to adjacent Shield TBM tunnelling by considering various reinforcement conditions. The numerical modelling has analysed the effect of the pile cutting, ground reinforcement and pile cap reinforcement. The analyses concentrate on the ground settlements, the pile head settlements, the axial pile forces and the shear stress transfer mechanism at the pile-soil interface. In all cases of the pile tips supported by weathered rock, the distributions of shear stresses presented a similar trend. Also, when the pile tips were cut, tensile forces or compressive forces were induced on the piles depending on the relative positions of the piles. Furthermore, when the pile tips are supported by weathered rock, approximately 70% of the load is supported by surface friction, and only the remaining 30% is supported by the pile tip. Furthermore the final settlement of the piles without reinforcement showed approximately 70% more settlement than the piles for which ground reinforcement is considered. It has been found that the ground settlements and the pile settlements are heavily affected by the pile cutting and reinforcement conditions. The behaviour of the single pile and group piles, depending on the pile cutting, conditions of ground and pile cap reinforcement, has been extensively examined and analysed by considering the key features in great details.

The Change in Refractive Powers of Soft Contact Lenses Caused by the Deposition of Tear Proteins (누액 단백질 침착에 의한 소프트콘택트렌즈의 굴절력 변화)

  • Choi, Jin-Yong;Park, Jae-Sung;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.16 no.4
    • /
    • pp.383-390
    • /
    • 2011
  • Purpose: The present study was conducted to investigate whether refractive powers of soft contact lenses were induced by the deposition of tear proteins when wearing soft contact lenses. Methods: The soft contact lenses (material: etafilcon A, hilafilcon A and comfilcon A) with refractive powers of -1.00 D, -3.00 D, -5.00 D and -7.00 D were incubated in artificial tear for 1 day, 3 days, 5 days, 7 days and 14 days, respectively. After incubation, their refractive powers were measured by wet cell method with an auto-lens meter and their protein deposited on the lenses was determined by the method of Lowry. Results: Among three types of soft contact lenses, the most protein deposition was detected in ionic etafilcon A lens material and significant change of its refractive power was manifested. In other words, refractive powers of etafilcon A lenses firstly decreased after 1 day incubation in artificial tear and then gradually increased with increasing incubation period again. The observed change in refractive powers of all diopters of etafilcon A material was beyond the scope of standard error and bigger in the lens with lower optical power. On the other hand, non-ionic hilafilcon A showed less protein deposition as much as about 20% in etafilacon A and statistically significant increase of refractive powers with increasing incubation period in artificial tear. The change in refractive power of hilafilcon A was also beyond the scope of the standard of error when incubating in artificial tear and greater in the lens with lower diopter. The least protein deposit was shown in silicone hydrogel lens material, comfilcon A as approximately 10% of it in etafilcon A, indicating less change in refractive power within the standard range of error. Conclusions: The large change of refractive powers that was beyond the scope of standard error by the deposition of tear proteins on soft contact lenses was differently detected depending on lens materials in the current study. Thus, the deposition of tear proteins induced by longer period of lens wearing may be one of the causes that induces blurred vision, suggesting that soft contact lens wearers with the amount of tear proteins may need to choose proper lens material.

Callus Induction and Differentiation from Rice (Oryza Sativa L.) Anthers (벼 약(葯)으로부터 callus 형성(形成)과 분화(分化)에 대(對)하여)

  • Kim, Dal Ung;Bae, Min Gyu
    • Current Research on Agriculture and Life Sciences
    • /
    • v.1
    • /
    • pp.1-9
    • /
    • 1983
  • This study was conducted to obtain basic information on the rice anther culture. Materials used were (Inabawase X YR 2404-14-2-1) $F_1$ hybrid. Callus growth rate on various media, induction frequency of callus in spikelet and panicle, and the effect of treatment on anther and callus were evaluated. The results obtained were summarized as follows ; The growth rate of callus on N-6, M-S, P.E.agar media was 19.8, 13.1, 4.1 times respectively after 30 days inoculated, and on liquid media was 3.8, 5.1, 1.4 times, respectively. Organ differentiation on N-6, M-S, P.E.agar media was 37.5%, 12.5%, 17.5% respectively. The difference of induction frequency of callus per panicle was 0.14%-6.25% and per spikelet was 0-19.05%. Almost callus was induced 30-35 days after inoculation. Organ differentiation of induced callus was decreased by culture. Callus cultured for 13 days after induction did not make shoot. Anthers cold shocked at $8^{\circ}C$ for 5 days obtained 3.32% efficiencys of callus induction per number of anthers plated, and compared with 2.41% of no treated anthers. But anther treated at $8^{\circ}C$ for 7 days decreased 2.24%. Callus induction periods were shortened by cold treatment for about 5 days. Callus cultured on medium containing 2 mg/l of 2, 4-D showed 5% on root formation but medium containing 5 mg/l of 2, 4-D showed 30% of root formation after transfered on the medium without 2, 4-D. Callus cold shocked at $15-18^{\circ}C$ revealed poor efficiency for root formation, but 5 days treatment was good for shoot formation.

  • PDF

Effects of Pomace of Schizandra chinensis, Schizandrin, and Gomisin A on LPS-induced Inflammatory Responses in RAW264.7 Cells (오미자 박, schizandrin 및 gomisin A에 의한 RAW264.7 세포주에서 lipopolysaccharide로 유도된 염증 반응의 억제)

  • Seo, Yu-Mi;Kim, Hyun-Ji;Lee, Eun-Joo;Chung, Chungwook;Sung, Hwa-Jung;Sohn, Ho-Yong;Park, Jong-Yi;Kim, Jong-Sik
    • Journal of Life Science
    • /
    • v.28 no.3
    • /
    • pp.339-344
    • /
    • 2018
  • Schizandra chinensis has been used as a traditional Chinese medicine and is known to have various bioactive components, including schizandrin and gomisin A. In the current study, we investigated the anti-inflammatory activities and their working mechanisms of ethanol extracts of pomace of Schizandra chinensis (PSC), schizandrin (SZ), and gomisin A (GA). First, we analyzed the effects of PSC on nitric oxide (NO) production and cell viabilities in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results indicated that PSC dramatically reduced NO production in LPS-activated RAW264.7 cells in a dose-dependent manner without affecting cell viabilities. PSC also decreased the expression of pro-inflammatory genes iNOS and COX-2, whereas the expression of TNF-${\alpha}$ was not affected by PSC. In addition, PSC inhibited phosphorylation of p38, ERK1/2, and JNK but did not change the expression of their total protein. The results indicate that PSC can regulate LPS-induced inflammatory responses by suppressing MAPK (mitogen-activated protein kinase) signaling. We also analyzed the effects of SZ and GA on NO production and cell viabilities in RAW264.7 cells. The results showed that SZ and GA also decreased NO production in a dose-dependent manner in LPS-activated RAW 264.7 cells without affecting cell viabilities. SZ reduced the expression of iNOS, whereas GA downregulated iNOS and COX-2. Overall, these findings clarify the molecular mechanisms of the anti-inflammatory effects mediated by PSC, SZ, and GA.

High frequency somatic embryogenesis through leaf explant-derived callus culture in Muscari armeniacum cv. 'Early Giant' (무스카리 'Early Giant' 잎 절편 유래 캘러스 배양을 통한 고빈도 체세포배 발생)

  • Lee, Hyang-Bun;Jeon, Su-Min;Chung, Mi-Young;Han, Jeung-Sul;Kim, Chang-Kil;Lim, Ki-Byung;Chung, Jae-Dong
    • Journal of Plant Biotechnology
    • /
    • v.39 no.1
    • /
    • pp.69-74
    • /
    • 2012
  • Using calli of $Muscari$ $armeniacum$ cv. 'Early Giant' that is monocotyledonous ornamental bulb crop with increasing demand in Korea, we carried out current studies to establish an in vitro multiple propagation protocol via somatic embryogenesis. We found that soft pale yellow green calli were induced from leaf explants cultured on all media containing 0.1~3.0 $mg{\cdot}L^{-1}$ auxins such as 1-naphthalene acetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). However, induced calli showed vigorous growth only when they further transferred on same media containing 2,4-D, 4-amino-3,5,6-tri-chloropicolinic acid (picloram), or 3,6-dichloro-o-anisic acid (dicamba). Although frequency of somatic embryo induction depended on callus source and PGR composition in somatic embryo induction media, somatic embryogenesis was initiated on surface of proliferated calli after transferring on media with no PGR or 0.01 $mg{\cdot}L^{-1}$ NAA co-supplemented with various cytokinins such as $N^6$-benzylaminopurine (BAP). Highest number of embryo at 9.3 per callus clump was obtained when calli which were grown under 0.1 $mg{\cdot}L^{-1}$ picloram supplementation were sub-cultured on medium with 0.01 $mg{\cdot}L^{-1}$ NAA and 0.5 $mg{\cdot}L^{-1}$ BAP. In addition, morphological characteristics of somatic embryo were categorized into following nine phases: globular, biased heart, biased torpedo, early cotyledonary, middle cotyledonary, late cotyledonary, early sprouting, middle sprouting, and late sprouting embryos.

Effects of Locus Coeruleus/Subcoeruleus Stimulation on the Tail Flick Reflex and Efflux of Noradrenaline into the Spinal Cord Superfusates (청반핵 자극으로 인한 노르아드레날린의 유리가 동통의 조절에 미치는 영향)

  • Park, Kyung-Pyo;Kim, Jong-Sung;Suh, Dae-Chul;Park, Hyoung-Sup
    • The Korean Journal of Pharmacology
    • /
    • v.30 no.1
    • /
    • pp.29-37
    • /
    • 1994
  • Inhibition of the nociceptive Tail Flick Reflex (TFR) was observed with electrical stimulation of the locus coeruleus/subcoeruleus (LC/SC) in the male Sprague - Dawley rats under light anesthesia, and the involved neurotransmitter (s) were characterized. Electrical stimulation of LC/SC induced the analgesia with the stimulation threshold (intensity of the current, given for 100 usec and in 100 Hz frequency, which caused the TF latency longer than 6.5 sec) around 55 uA. Intrathecal administrations of ${\alpha}_2$ antagonist, yohimbine (30 ug) or opioid antagonist, naloxone (20 ug) increased the stimulation threshold by 147% and 123% respectively (from 55 uA to 135 uA,9 and from 54 uA to 123 uA;P0.01, n=5, each). The basal TF latency without stimulation (3.1 sec) was reduced by the antagonists (to 2.5 sec by yohimbine, p<0.05, n=5; to 2.6 sec by naloxone, p<0.1, n=5), vehicle only did not show any effect. Noradrenaline(NA) in the spinal cord superfusates measured with HPLC was increased by the LC/SC stimulation, from 4.18 ng/ml before to 7.74 ng/ml after stimulation (P<0.05, n=10). The result suggest that analgesia induced by LC/SC stimulation is mediated, at least in part, by the noradrenergic system in which ${\alpha}_2$ receptor is involved, as well as the opioid system.

  • PDF

Effects of Prostaglandin $F_{2{\alpha}}$ on the Concentrations of Ovarian and Pituitary Hormones in Korean Native Goats (한국재래산양(韓國在來山羊)에 있어서 Prostaglandin $F_{2{\alpha}}$의 투여(投與)가 난소(卵巢) 및 뇌하수체(腦下垂體) Hormone의 함량(含量)에 미치는 영향(影響))

  • Kwon, Chun Su;Byun, Myung Dae;Jang, In Ho
    • Current Research on Agriculture and Life Sciences
    • /
    • v.6
    • /
    • pp.181-186
    • /
    • 1988
  • This experiment was conducted to examine the $PGF{2{\alpha}}$-induced changes in concentrations of ovarian and pituitary hormones of Korean native goats. Each goats received two injections of $PGF{2{\alpha}}$ (5mg each ; 3 hours apart) on day 10 of the estrous cycle. Jugular venous blood samples were collected at 0, 3, 6, 12, 24, 48 and 72 hours postinjection for quantification of LH, FSH, prolactin, progesterone and estradiol-$17{\beta}$. The results were summarized as follows ; The blood serum concentration of progesterone was decreased from pretreatment level of $4.15{\pm}1.8ng/ml$ to $2.52{\pm}1.2ng/ml$ (about 60%) within 3 hours and to $0.81{\pm}0.3ng/ml$ at 12 hours of the $PGF{2{\alpha}}$ injection. After 12 hours, the concentrations of progesterone were less than 1.02ng/ml by 72 hours postinjection. The concentrations of estradiol-$17{\beta}$ following treatment increased (p < 0.05) over the 72 hours. Initial concentration of LH was $3.0{\pm}0.3{\mu}IU/ml$. After treatment with $PGF{2{\alpha}}$, concentrations of LH increased within 12 hours but declined 12 and 72 hours from $4.1{\mu}IU/ml$ to $2.5{\mu}IU/ml$. Prior to administration of $PGF{2{\alpha}}$, mean concentration of FSH was $3.5{\pm}0.5{\mu}IU/ml$. Concentrations of FSH declined over time in goats treated with $PGF{2{\alpha}}$ on day 10 postestrus. The mean prolactin concentrations in the blood serum after $PGF{2{\alpha}}$ treatment were not significantly different from those of the pretreatment. It is concluded that the initial increase in LH is dependent on a decrease in serum progesterone and differences in patterns of secretion of gonadotropins might be caused by differences in progesterone or progesterone-estradiol ratio when luteal regression is induced on day 10 of the estrous cycle.

  • PDF

Screening and Physiological Characteristics of Mutants in Rhizobium japonicum (Rhizobium japonicum에 있어서 변이주(變異株)의 선발(選拔) 및 특성(特性))

  • Park, Chang Dong;Kang, Sang Jai;Park, Woo Churl
    • Current Research on Agriculture and Life Sciences
    • /
    • v.12
    • /
    • pp.57-68
    • /
    • 1994
  • This experiment was conducted to isolate the mutants from S118 and to investigate the physiological characteristics of R. japonicum mutants. The results obtained were as follows; Based on nodulation and acetylene reduction, nodulation of rhizobia was divided into 4 groups, i.e. slow-nodulation, earlier-nodulation, infrequent-nodulation and non-nodulation. At 5% significant level, the growth of inoculated plant with SM255 was bad, but that of HP277 was good. Root-hairs curling was induced by strains S118 and HP277 on soybean, but not by strain SM255. S118 and SM255 were found to be slow-gorwers and produced alkali, whereas strain HP277 was fast-grower and produced acid in YEM broth. In litmus milk reaction, all strains indicated alkaline reaction, and serume-zone was induced weakly by HP277. All of the strains tested in this experiment utilized sucrose. HP277 and LP268 utilized xylose, whereas S118 and SM255 did not. SM255 showed bad growth in nitrogen carriers however utilization of $Ca(NO_3)_2{\cdot}4H_2O$ by HP277 was possible at 25mM and 10mM level. To compare with S118, the protein band of SM255's cell protein electrophoresis was not developed at 0.62 Rm position.

  • PDF

Finding Influential Users in the SNS Using Interaction Concept : Focusing on the Blogosphere with Continuous Referencing Relationships (상호작용성에 의한 SNS 영향유저 선정에 관한 연구 : 연속적인 참조관계가 있는 블로고스피어를 중심으로)

  • Park, Hyunjung;Rho, Sangkyu
    • The Journal of Society for e-Business Studies
    • /
    • v.17 no.4
    • /
    • pp.69-93
    • /
    • 2012
  • Various influence-related relationships in Social Network Services (SNS) among users, posts, and user-and-post, can be expressed using links. The current research evaluates the influence of specific users or posts by analyzing the link structure of relevant social network graphs to identify influential users. We applied the concept of mutual interactions proposed for ranking semantic web resources, rather than the voting notion of Page Rank or HITS, to blogosphere, one of the early SNS. Through many experiments with network models, where the performance and validity of each alternative approach can be analyzed, we showed the applicability and strengths of our approach. The weight tuning processes for the links of these network models enabled us to control the experiment errors form the link weight differences and compare the implementation easiness of alternatives. An additional example of how to enter the content scores of commercial or spam posts into the graph-based method is suggested on a small network model as well. This research, as a starting point of the study on identifying influential users in SNS, is distinctive from the previous researches in the following points. First, various influence-related properties that are deemed important but are disregarded, such as scraping, commenting, subscribing to RSS feeds, and trusting friends, can be considered simultaneously. Second, the framework reflects the general phenomenon where objects interacting with more influential objects increase their influence. Third, regarding the extent to which a bloggers causes other bloggers to act after him or her as the most important factor of influence, we treated sequential referencing relationships with a viewpoint from that of PageRank or HITS (Hypertext Induced Topic Selection).

The Role of Heme Oxygenase-1 in Lung Cancer Cells (폐암세포주에서 Heme Oxygenase-1의 역할)

  • Jung, Jong-Hoon;Kim, Hak-Ryul;Kim, Eun-Jung;Hwang, Ki-Eun;Kim, So-Young;Park, Jung-Hyun;Kim, Hwi-Jung;Yang, Sei-Hoon;Jeong, Eun-Taek
    • Tuberculosis and Respiratory Diseases
    • /
    • v.60 no.3
    • /
    • pp.304-313
    • /
    • 2006
  • Background : Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the oxidative degradation of heme to form biliverdin, carbon monoxide (CO), and free iron. The current evidence has indicated a critical role of HO-1 in cytoprotection and also in other, more diverse biological functions. It is known that the high expression of HO-1 occurs in various tumors, and that HO-1 has an important role in rapid tumor growth because of its antioxidative and antiapoptotic effects. Therefore, the role of HO-1 was analyzed in human lung cancer cell lines, and especially in the A549 cell line. Material and Methods : Human lung cancer cell lines, i.e., A549, NCI-H23, NCI-H157 and NCI-H460, were used for this study. The expression of HO-1 in the untreated state was defined by Western blotting. ZnPP, which is the specific HO inhibitor we used, and the viability of cells were tested for by conducting MTT assaysy. The HO enzymatic activity, as determined via the bilirubin level, was also indirectly measured. Moreover, the generation of intracellular hydrogen peroxide (H2O2) was monitored fluorimetrically with using a scopoletin-horse radish peroxidase (HRP) assay and 2',7'-dichlorofluorescein diacetate (DCFH-DA). We have also transfected small HO-1 interfering RNA (siRNA) into A549 cells, and the apoptotic effects were evaluated by flow cytometric analysis and Western blotting. Results : The A549 cells had a greater expression of HO-1 than the other cell lines, whereas ZnPP significantly decreased the viability of the A549 cells more than the viability of the other lung cancer cells in a dose-dependant fashion. Consistent with the viability, the HO enzymatic activity also was decreased. Moreover, intracellular H2O2 generation via ZnPP was induced in a dose-dependent manner. Apoptotic events were, then induced in the HO-1 siRNA transfected A549 cells. Conclusion : HO-1 provides new important insights into the possible molecular mechanism of the antitumor therapy in lung cancer.