• Title/Summary/Keyword: cyclic response

Search Result 589, Processing Time 0.025 seconds

Self-Sensing and Interfacial Evaluation of Ni Nanowire/Polymer Composites Using Electro-Macromechanical Technique (전기적 미세역학적 시험법을 이용한 Ni nanowire강화 고분자 복합재료의 자체 감지능 및 계면 물성평가)

  • Kim, Sung-Ju;Yoon, Dong-Jin;Hansen George;DeVries K. Lawrence;Park, Joung-Man
    • Composites Research
    • /
    • v.19 no.5
    • /
    • pp.20-27
    • /
    • 2006
  • Self-sensing and interfacial evaluation of Ni nanowire/polymer composites were investigated using electro-macromechanical technique, which can be used fur a feasible sensing measurement on tensile and compressive loading/consequent unloading, temperature, and humidity. Mechanical properties of Ni nanowire with different aspect ratio and adding contents in either epoxy or silicone composites were measured indirectly using electro-pullout test under uniform and non-uniform cyclic loadings. Comparing apparent modulus with the conventional mechanical tensile modulus of Ni nanowire/epoxy composites, the trends were consistent with each other. Ni nanowire/epoxy composites showed the sensing response on humidity and temperature. Self-sensing on applied tensile and compressive loading/unloading was also responded for Ni nanowire/silicone composites via electrical contact resistivity showing the opposite trend between tension and compression. It can be due to the different electrically-interconnecting mechanisms of dispersed Ni nanowires embedded in silicone matrix.

Experimental and analytical study of squat walls with alternative detailing

  • Leonardo M. Massone;Cristhofer N. Letelier;Cristobal F. Soto;Felipe A. Yanez;Fabian R. Rojas
    • Computers and Concrete
    • /
    • v.33 no.5
    • /
    • pp.497-507
    • /
    • 2024
  • In squat reinforced concrete walls, the displacement capacity for lateral deformation is low and the ability to resist the axial load can quickly be lost, generating collapse. This work consists of testing two squat reinforced concrete walls. One of the specimens is built with conventional detailing of reinforced concrete walls, while the second specimen is built applying an alternative design, including stirrups along the diagonal of the wall to improve its ductility. This solution differs from the detailing of beams or coupling elements that suggest building elements equivalent to columns located diagonally in the element. The dimensions of both specimens correspond to a wall with a low aspect ratio (1:1), where the height and length of the specimen are 1.4 m, with a thickness of 120 mm. The alternative wall included stirrups placed diagonally covering approximately 25% of the diagonal strut of the wall with alternative detailing. The walls were tested under a constant axial load of 0.1f'cAg and a cyclic lateral displacement was applied in the upper part of the wall. The results indicate that the lateral strength is almost identical between both specimens. On the other hand, the lateral displacement capacity increased by 25% with the alternative detailing, but it was also able to maintain the 3 complete hysteretic cycles up to a drift of 2.5%, reaching longitudinal reinforcement fracture, while the base specimen only reached the first cycle of 2% with rapid degradation due to failure of the diagonal compression strut. The alternative design also allows 46% more energy dissipation than the conventional design. A model was used to capture the global response, correctly representing the observed behavior. A parametric study with the model, varying the reinforcement amount and aspect ratio, was performed, indicating that the effectiveness of the alternative detailing can double de drift capacity for the case with a low aspect ratio (1.1) and a large longitudinal steel amount (1% in the web, 5% in the boundary), which decreases with lower amounts of longitudinal reinforcement and with the increment of aspect ratio, indicating that the alternative detailing approach is reasonable for walls with an aspect ratio up to 2, especially if the amount of longitudinal reinforcement is high.

Expression and Localization of ATF4 Gene on Oxidative Stress in Preimplantation Mouse Embryo (생쥐 착상전 배아에서 산화적 스트레스에 의한 ATF4 유전자의 발현과 존재 부위)

  • Na, Won-Heum;Kang, Han-Seung;Eo, Jin-Won;Gye, Myung-Chan;Kim, Moon-Kyoo
    • Development and Reproduction
    • /
    • v.10 no.2
    • /
    • pp.105-113
    • /
    • 2006
  • Reactive oxygen species(ROS) generated in cellular metabolism have an effect on cell maturation and development. In human reproductive tract, oxidative injury by ROS may induce female infertility. Also, oxidative injury may be responsible for developmental retardation and arrest of mammalian preimplantation embryos. Activating transcription factor 4(ATF4) is a member of the cyclic-AMP response element-binding(CREB) familiy of basic region- leucine zipper(bZip). ATF4 is known to regulate stress response to protect cell from various stress factors and inducer of apoptisis. The purpose of this study was to investigate whether ATF4 is involved in the defensive mechanism in oxidative stress condition during the development of mouse preimplantation embryos. To verify the expression of ATF4 in oxidative stress condition, 2-cell stage embryos were cultured in HTF media containing 0.1mM, 0.5mM or 1mM hydrogen peroxide($H_2O_2$) for 1hr(2-cell), 8hr(4-cell), 17hr(8-cell), 24hr(morula), 48hr(early blastocyst) or 64hr(late blastocyst). The developmental rate decreased in the 0.1mM $H_2O_2$ treated group compared with control group. In embryos treated with 0.5mM and 1mM $H_2O_2$ showed 2-cell block. As a results of the semi-quantitative RT-PCR analysis of SOD1, ATF4 and Bax gene expression, SOD1, ATF4 and Bax genes were increased in 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. In 2-cell embryos, expression of SOD1, ATF4 and Bax genes were notably increased in 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. Immunofluorescence analysis showed that ATF4 protein was localized at the cytoplasm of preimplantation embryos. The increase in ATF4 immunoreactivety was observed in the 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. It suggests that oxidative stress by $H_2O_2$ induces expression of ATF4 and may be involved in protection mechanism in preimplantation embryos from oxidative injury.

  • PDF

Effects of Sinetrol-XPur on Leptin-Deficient Obese Mice and Activation of cAMP-Dependent UCP-2 (Leptin 유전자 결핍 동물모델을 이용한 시네트롤(Sinetrol-XPur)의 항비만 효과와 cAMP를 통한 UCP-2 활성화 기전 연구)

  • Yoo, Jae Myeong;Lee, Minhee;Kwon, Han Ol;Choi, Sei Gyu;Bae, Mun Hyoung;Kim, Ok-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.4
    • /
    • pp.484-491
    • /
    • 2016
  • The present study investigated the effect of Sinetrol-XPur (polyphenolic Citrus spp. and Paullinia cupana Kunth dry extract) and defined the action mode for cyclic adenosine monophosphate (cAMP)-dependent uncoupling protein (UCP)-2 activation. Leptin-deficient obese mice were treated with two different doses, 100 mg/kg body weight (BW) and 300 mg/kg BW of each AIN93G supplement, for 7 weeks. Treatment of obese mice with both low and high doses of Sinetrol-XPur significantly reduced body weight gain compared to control obese mice. White adipose tissue weight of mice was reduced by 30.96% in high dose-supplemented groups. Serum total cholesterol and triglyceride were reduced by a high dose of Sinetrol-XPur by 20.02% and 30.96%, respectively. Serum level of high density lipoprotein (HDL) was significantly increased by treatment with both doses, as the ratio of HDL to low density lipoprotein increased by 138.78% and 171.49%, respectively. Regarding expression of biochemical factors related to lipid metabolism, fatty acid synthase significantly decreased and UCP-2 increased upon treatment with a high dose of Sinetrol-XPur, but there was no significant difference in lipoprotein lipase and hormone-sensitive lipase. To define cellular mechanism, intracellular cAMP levels in 3T3-L1 adipocytes significantly increased in a dose-dependent manner over the range of $50{\sim}250{\mu}m/mL$. The phosphodiesterase (PDE) inhibitor 3-isobutyl-1-methylxanthine clearly blocked cAMP, suggesting that Sinetrol-XPur promotes lipolysis of adipocytes through inhibition of cAMP-dependent PDE, resulting in induction of cAMP response element binding protein and UCP-2. These results suggest that Sinetrol-XPur supplementation is a viable option for reducing body weight and fat by improving serum lipid profiles and genetic expression of lipid metabolic factors, especially activation of cAMP-dependent UCP-2.

Sensory Characteristics of Doenjang with Added Licorice Powder as Assessed by Response Surface Methodology (반응표면분석법을 이용한 감초분말 첨가 된장의 관능적 특성)

  • Kim, Mi-Lim;Park, Eun-Jung;Jeong, Ji-Suk
    • Korean journal of food and cookery science
    • /
    • v.26 no.1
    • /
    • pp.62-71
    • /
    • 2010
  • The followings describes the result of making doenjang with added licorice (Glycyrrhiza uralensis) powder. and investigating its sensory characteristics and physicochemical quality. General preference was high at 20% salinity and 2% licorice (LD204), and 16% salinity and 2% licorice (LD162). The moisture content was unchanged in the control group, while it was reduced in LD204 and LD162 in the first week of fermentation, but showed little change after then. pHs were all in the range 5.90~5.97 on day 0, but decreased from 5.90 to 5.72 in the control group in the fifth week. LD204 changed from 5.95 on day 0to 5.42 in the first week, and then it gradually increased again and became 5.93 in the fifth week, which was similar to that of day 0. LD162 was 5.97 on day 0 and showed cyclic slight increases and decreases in the first week. It increased to 6.32 in the fifth week, which was higher than that of day 0 that is, its pH was higher than that of LD204. The acidity showed a difference right after it was made. In the control group, lactic acid content gradually increased from 0.16% on day 0 to the highest, 0.59%, in the fourth week. It slightly decreased in the fifth week. LD204 slowly increased from 0.25% on day 0 to a maximum, 0.50%, in the fourth week. It also slightly decreased in the fifth week, quite similarly to that of the control group. LD162, gradually increased from 0.22% on day 0 to the highest, 0.49, in the third week, and decreased after the fourth week. Salinity was 29.5%, 22.0%, and 18% in each of the control group, LD204, and LD162 on day 0 but increased to 34.0%, 29.0%, and 26.0% in the fifth week. Soluble solid was $32^{\circ}Brix$, $28^{\circ}Brix$, and $26^{\circ}Brix$ in each of the control group, LD204, and LD162 on day 0, but slightly increased to $40^{\circ}Brix$, $32^{\circ}Brix$, and $30^{\circ}Brix$ on the fifth day. It is thought that because of the sweetness of licorice, the higher-salinity doenjang earned a higher sensory test score than that of traditional doenjang. If its salinity is lowered a little, it could be used as a sauce, even possibly having medical effects as well.

Effects of Aqua-Acupuncture of Carthami Flos(GV15) on the Changes of Cerebral Hemodynamics in Rats (아문(瘂門)(GV15)의 홍화약침(紅花藥針)이 백서(白鼠)의 뇌혈류역학(腦血流力學) 변동(變動)에 미치는 영향(影響))

  • Ahn, Young-sun;Wei, Tung-shuen;Cho, Myung-rae;Chae, Woo-seok;Yun, Yeo-choong
    • Journal of Acupuncture Research
    • /
    • v.19 no.5
    • /
    • pp.92-111
    • /
    • 2002
  • Objective : Carthami Flos has been used as a herb to promote blood circulation to remove blood stasis in oriental medicine for many centuries, and Amun(GV15) has been used as a meridian point to treat apoplexy etc. To investigate treatment of cerevral vascular disease(CVA) by promoting blood circulation and removing blood stasis(活血化瘀法), we observed the experimental effects and mechanism of auqa-acupunture of Carthami Flos(ACF) injected into GV15 on cerevral hemodynamics and cardiovascular system of rats. Method : Aqua-acupuncture of Carthami Flos(ACF) was injected into GV15, and then we investigated experimental effects and mechanism of ACF on the cerebral hemodynamics[regional cerebral blood flow(rCBF), pial arterial diameter(PAD), meal arterial blood pressure(MABP)] and cardiovascular system[cardiac muscle contractile force(CMF), heart rate(HR)I by pretreatment with methylene blue(MTB) and indomethacin(IDN). The changes in rCBF, MABP, CMF and HR were tested by Laser Doppler Flowmetry(LDF), and the changes in PAD was determinated by video microscopy methods and video analyzer. Results :The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACE induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion. The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACF induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion Conclusions : In conclusion, ACF causes a diverse response of rCBF, PAD an HR, and action of ACF is mediated by cyclic GMP. I suggested that ACF has an anti-ischemic effect through the improvement of crebral hemodynamics in a transient cerebral ischemia.

  • PDF

Treat-to-Target Strategy for Asian Patients with Early Rheumatoid Arthritis: Result of a Multicenter Trial in Korea

  • Song, Jason Jungsik;Song, Yeong Wook;Bae, Sang Cheol;Cha, Hoon-Suk;Choe, Jung-Yoon;Choi, Sung Jae;Kim, Hyun Ah;Kim, Jinseok;Kim, Sung-Soo;Lee, Choong-Ki;Lee, Jisoo;Lee, Sang-Heon;Lee, Shin-Seok;Lee, Soo-Kon;Lee, Sung Won;Park, Sung-Hwan;Park, Won;Shim, Seung Cheol;Suh, Chang-Hee;Yoo, Bin;Yoo, Dae-Hyun;Yoo, Wan-Hee
    • Journal of Korean Medical Science
    • /
    • v.33 no.52
    • /
    • pp.346.1-346.11
    • /
    • 2018
  • Background: To evaluate the therapeutic benefits of the treat-to-target (T2T) strategy for Asian patients with early rheumatoid arthritis (RA) in Korea. Methods: In a 1-year, multicenter, open-label strategy trial, 346 patients with early RA were recruited from 20 institutions across Korea and stratified into 2 groups, depending on whether they were recruited by rheumatologists who have adopted the T2T strategy (T2T group) or by rheumatologists who provided usual care (non-T2T group). Data regarding demographics, rheumatoid factor titer, anti-cyclic citrullinated peptide antibody titer, disease activity score of 28 joints (DAS28), and Korean Health Assessment Questionnaire (KHAQ) score were obtained at baseline and after 1 year of treatment. In the T2T group, the prescription for disease-modifying antirheumatic drugs was tailored to the predefined treatment target in each patient, namely remission (DAS28 < 2.6) or low disease activity (LDA) ($2.6{\leq}DAS28$ < 3.2). Results: Data were available for 163 T2T patients and 162 non-T2T patients. At the end of the study period, clinical outcomes were better in the T2T group than in the non-T2T group (LDA or remission, 59.5% vs. 35.8%; P < 0.001; remission, 43.6% vs. 19.8%; P < 0.001). Compared with non-T2T, T2T was also associated with higher rate of good European League Against Rheumatism response (63.0% vs. 39.8%; P < 0.001), improved KHAQ scores (-0.38 vs. -0.13; P = 0.008), and higher frequency of follow-up visits (5.0 vs. 2.0 visits/year; P < 0.001). Conclusion: In Asian patients with early RA, T2T improves disease activity and physical function. Setting a pre-defined treatment target in terms of DAS28 is recommended.

Cognitive Improvement Effects of Krill Oil in a Scopolamine-induced Mice Model (Scopolamine 유도 인지 저하 마우스 모델에서 크릴 오일의 인지 개선 효과)

  • Hye-Min Seol;Jeong-Ah Lee;Mi-Sun Hwang;Sang-Hoon Park;Hyeong-Soo Kim
    • Journal of Life Science
    • /
    • v.34 no.7
    • /
    • pp.509-519
    • /
    • 2024
  • A previous study showed that krill oil improved recognition and memory through anti-oxidative effects in an amyloid β model, but the authors noted that further investigations are necessary of alterations to neurotransmitters' states and of serum lipid profile improvements related to serum lipid peroxidation. Accordingly, in this study, ICR mice were pre-treated intraperitoneally with scopolamine prior to induced neurotransmission impairment, and the effects of krill oil provision on their capabilities of cognition were tested by performing a passive avoidance test (PAT), water maze test (WMT), and novel object recognition test. Then, parameters including the acetylcholine (ACh) concentration, acetylcholinesterase activity (AChE), lipid peroxidation, serum lipid levels, and nerve cell proliferation were investigated. The results showed that krill oil improved the mice's abilities in recognition and memory as the times taken to complete the PAT and WMT were reduced compared to the mice in a comparison scopolamine-treated group. Krill oil produced an increased concentration of Ach, and this was accompanied by a decrease in AChE. As shown in a scopolamine-treated SH-SY5Y cell line, krill oil reduced the activity of AChE. Moreover, the suppression of lipid peroxidation-reflected in the finding that malondialdehyde was decreased with krill oil provision-is speculated to affect the recorded serum triglyceride and cholesterol decreases and LDL cholesterol increase. The intake of krill oil was also found to produce an improvement in brain-derived neurotrophic factor expression by stimulating the activation of cyclic AMP response element binding protein in the brain tissue. Overall, the current results imply that the provision of krill oil raises the cognition and memory by elevating neurotransmitters and by improving the serum lipid profile and nerve cell proliferation, which occur as lipid peroxidation is suppressed in the brain tissue.

Stratigraphic response to tectonic evolution of sedimentary basins in the Yellow Sea and adjacent areas (황해 및 인접 지역 퇴적분지들의 구조적 진화에 따른 층서)

  • Ryo In Chang;Kim Boo Yang;Kwak won Jun;Kim Gi Hyoun;Park Se Jin
    • The Korean Journal of Petroleum Geology
    • /
    • v.8 no.1_2 s.9
    • /
    • pp.1-43
    • /
    • 2000
  • A comparison study for understanding a stratigraphic response to tectonic evolution of sedimentary basins in the Yellow Sea and adjacent areas was carried out by using an integrated stratigraphic technology. As an interim result, we propose a stratigraphic framework that allows temporal and spatial correlation of the sedimentary successions in the basins. This stratigraphic framework will use as a new stratigraphic paradigm for hydrocarbon exploration in the Yellow Sea and adjacent areas. Integrated stratigraphic analysis in conjunction with sequence-keyed biostratigraphy allows us to define nine stratigraphic units in the basins: Cambro-Ordovician, Carboniferous-Triassic, early to middle Jurassic, late Jurassic-early Cretaceous, late Cretaceous, Paleocene-Eocene, Oligocene, early Miocene, and middle Miocene-Pliocene. They are tectono-stratigraphic units that provide time-sliced information on basin-forming tectonics, sedimentation, and basin-modifying tectonics of sedimentary basins in the Yellow Sea and adjacent area. In the Paleozoic, the South Yellow Sea basin was initiated as a marginal sag basin in the northern margin of the South China Block. Siliciclastic and carbonate sediments were deposited in the basin, showing cyclic fashions due to relative sea-level fluctuations. During the Devonian, however, the basin was once uplifted and deformed due to the Caledonian Orogeny, which resulted in an unconformity between the Cambro-Ordovician and the Carboniferous-Triassic units. The second orogenic event, Indosinian Orogeny, occurred in the late Permian-late Triassic, when the North China block began to collide with the South China block. Collision of the North and South China blocks produced the Qinling-Dabie-Sulu-Imjin foldbelts and led to the uplift and deformation of the Paleozoic strata. Subsequent rapid subsidence of the foreland parallel to the foldbelts formed the Bohai and the West Korean Bay basins where infilled with the early to middle Jurassic molasse sediments. Also Piggyback basins locally developed along the thrust. The later intensive Yanshanian (first) Orogeny modified these foreland and Piggyback basins in the late Jurassic. The South Yellow Sea basin, however, was likely to be a continental interior sag basin during the early to middle Jurassic. The early to middle Jurassic unit in the South Yellow Sea basin is characterized by fluvial to lacustrine sandstone and shale with a thick basal quartz conglomerate that contains well-sorted and well-rounded gravels. Meanwhile, the Tan-Lu fault system underwent a sinistrai strike-slip wrench movement in the late Triassic and continued into the Jurassic and Cretaceous until the early Tertiary. In the late Jurassic, development of second- or third-order wrench faults along the Tan-Lu fault system probably initiated a series of small-scale strike-slip extensional basins. Continued sinistral movement of the Tan-Lu fault until the late Eocene caused a megashear in the South Yellow Sea basin, forming a large-scale pull-apart basin. However, the Bohai basin was uplifted and severely modified during this period. h pronounced Yanshanian Orogeny (second and third) was marked by the unconformity between the early Cretaceous and late Eocene in the Bohai basin. In the late Eocene, the Indian Plate began to collide with the Eurasian Plate, forming a megasuture zone. This orogenic event, namely the Himalayan Orogeny, was probably responsible for the change of motion of the Tan-Lu fault system from left-lateral to right-lateral. The right-lateral strike-slip movement of the Tan-Lu fault caused the tectonic inversion of the South Yellow Sea basin and the pull-apart opening of the Bohai basin. Thus, the Oligocene was the main period of sedimentation in the Bohai basin as well as severe tectonic modification of the South Yellow Sea basin. After the Oligocene, the Yellow Sea and Bohai basins have maintained thermal subsidence up to the present with short periods of marine transgressions extending into the land part of the present basins.

  • PDF