• 제목/요약/키워드: Accumulation, Resistance

검색결과 304건 처리시간 0.028초

전기화학 임피던스 분석을 통한 자동차용 코일스프링 강의 부식 평가 (Study on Corrosion of Automotive Coil Spring Steel by Electrochemical Impedance Spectroscopy)

  • 이규혁;박중현;안승호;서지원;장희진
    • Corrosion Science and Technology
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    • 제16권6호
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    • pp.298-304
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    • 2017
  • Coil spring steels from the automobile suspension part after field exposure for 10 years and those after anti-corrosion validation test in proving ground of 5,000 ~ 10,000 km were examined for corrosion damages. Partial loss of paint, accumulation of corrosion product, and cracking of paint and superficial material were observed. The surface and subsurface region of spring steels had compressive residual stress and high hardness by shot peening. The surface hardness values of the specimens were 620 ~ 670 Hv. They were 60 ~ 80 Hv higher than those of the samples taken from the middle part of the spring. The maximum compressive stress was -916 ~ -1208 MPa measured at depth of about $100{\mu}m$. Electrochemical impedance spectroscopy showed that the resistances of charge transfer and the paint layer of the spring steels ranged from several tens to millions ${\Omega}{\cdot}cm^2$. The resistance of the field samples was much higher than that of the proving ground samples used in this study, implying that the proving ground test condition would be more corrosive than the field environment.

The Regulatory Effects of Trans-chalcone on Adipogenesis

  • Han, Younho
    • International Journal of Oral Biology
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    • 제43권1호
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    • pp.29-35
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    • 2018
  • It is noted that chalcone derivatives have characteristic diverse pharmacological properties, and that precise evidence has been growing that they could regulate a tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) induced insulin resistance. The purpose of the present investigation is to elucidate the effects of the identified chalcone derivatives on adipogenesis, and to find the underlying mechanism of action in that case. Consequently, we first investigated whether the chalcone derivatives could affect the identified $PPAR{\gamma}$-induced transcriptional activity on the proliferator-activated receptor response elements (PPRE) at target promoters, and find that trans-chalcone most significantly increased the $PPAR{\gamma}$-induced transcriptional activity. Additionally, we confirmed that there were up-regulatory effects of trans-chalcone during the adipogenesis and lipid accumulation, and on the mRNA of adipogenic factors in 3T3-L1 cells. Next, we examined the effect of trans-chalcone on the inhibition induced by $TNF-{\alpha}$ on adipogenesis. To that end, we noted that the treatment with trans-chalcone attenuated the effect of $TNF-{\alpha}$ mediated secretion of various adipokines that are involved in insulin sensitivity. For this reason, we noted that this study clearly demonstrates that trans-chalcone enhanced adipogenesis, in part, by its potent effect on $PPAR{\gamma}$ activation and by its reverse effect on $TNF-{\alpha}$.

건강 추출물의 뇌세포 보호 작용 (Neuroprotective Effects of the Extract of Zingiberis Rhizoma)

  • 정길생;리빈;이동성;최현규;김윤철
    • 생약학회지
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    • 제41권3호
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    • pp.190-195
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    • 2010
  • Glutamate-induced oxidative injury contributes to neuronal degeneration in many central nervous system (CNS) diseases, such as Parkinson's disease, Alzheimer's disease, epilepsy and ischemia. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a role in the pathogenesis of these diseases. NNMBS098, a composition comprising the water insoluble of the 70% EtOH extract of Zingiberis Rhizoma, showed the potent neuroprotective effects on glutamateinduced neurotoxicity by induced the expression of heme oxygenase (HO)-1 and increased HO activity in the mouse hippocampal HT22 cells. Furthermore, NNMBS098 caused the nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2) in mouse hippocampal HT22 cells. In addition, we found that treatment with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) reduced NNMBS098-induced HO-1 expression and NNMBS098 also increased JNK phosphorylation. Therefore, these results suggest that NNMBS098 increases cellular resistance to glutamate-induced oxidative injury in mouse hippocampal HT22 cells, presumably through JNK pathway-Nrf2-dependent HO-1 expression.

종양(腫瘍)의 전이(轉移) 및 재발(再發) 억제(抑制)에 관(關)한 고찰(考察) (A Study on the inhibition of metastasis and recurrence of neoplasm)

  • 김종대;조종관
    • 대한한방내과학회지
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    • 제18권2호
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    • pp.53-64
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    • 1997
  • Many types of cancer, current therapy other than surgery and/or radiotherapy was of only limited efficacy. At the basic chinese traditional medicine(TCM) there was increased understanding of the additional basic and clinical neoplasm treatment research. The metastasis and recurrence of neoplasm was the basis of yudu(餘毒) on remained neoplasm cell and stagnation of blood, thermotoxo, phlegm, asthenia of healthy enerngy, stagnation of vital energy. The principles therapy of neoplasm on metastasis and recurrence was based on knowledge of the method of support the healthy energy and strengthen the body resistance, promote blood circulation to remove blood stasis, clear away heat and toxic materials, dissipate phlegm and disperse the accumulation of evils, regulate vital energy and disperse the depressed vital energy. But the major clinical features of neoplasm was to be considered in developing a treatment plan include (1) distinguish between clinical and pathologic staging - acute and chronic, (2) classification of pathologic pattern, and (3) distinction of body situation : for examples asthenia - sthenia etc. It was most important to distinguish between supporting the healthy and eliminating the evil factors and to treat differently at the root and the branch cause of a neoplasm. This paper's results indicate that identification and effective use of TCM medicines inhibited netastasis and decreased recurrence and then we were able to expect increasing survival rate.

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The Effect of Ginseng on Heart Contraction and Sarcoplasmic Reticulum Function(II) The Effect of Ginseng on $^{45}Ca^{2+}$ Uptake by Sarcoplasmic Reticulum Fragments of Rat Heart

  • Sung, Baek-Yeon;Kim, Nak-Doo
    • Archives of Pharmacal Research
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    • 제6권1호
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    • pp.69-73
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    • 1983
  • It was reported from our laboratory that the rate of deterioration of the force of contraction was slower in heart from Panax ginseng extract treated rats. Present investigation was designed to elucidate the mechanism of the slow deterioration of contractility of ginseng treated hearts. Therefore, $^{45}Ca^{2+}$ Uptake by sarcoplasmic reticulum (SR) isolated from ginseng treated rate and control rats was studied. Rate weighing 150-250g were administered orally with ginseng ethanol extract (100mg/kg) for 10 days. Cardiac SR was isolated by differential centrifugation and $^{45}Ca^{2+}$ uptake was assessed by the Millipore method. Freshly isolated SR from treated as well as control animals did not show any differences, but after incubation for 30 and 60 min at 37.deg.C, $^{45}Ca^{2+}$ uptake of control animal SR was found to be greatly depressed. The SR of treated animal possessed a greater degree of resistance to incubation. Thus it can be concluded that ginseng may have an ability to sustain the normal function of the heart by sustaining Ca accumulation by SR involved with the excitationcontraction coupling processes.

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1-Benzyl indazole derivative-based 18F-labeled PET radiotracer: Radiosynthesis and cell uptake study in cancer cells

  • More, Kunal N.;Lee, Jun Young;Park, Jeong-Hoon;Chang, Dong-Jo
    • 대한방사성의약품학회지
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    • 제5권1호
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    • pp.36-47
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    • 2019
  • Hypoxia-inducible factor-1 ($HIF-1{\alpha}$) is a transcription factor activated in response to low oxygen level, and is highly expressed in many solid tumors. Moreover, $HIF-1{\alpha}$ is a representative biomarker of hypoxia and also helps to maintain cell homeostasis under hypoxic condition. Most solid tumors show hypoxia, which induces poor prognosis and resistance to conventional cancer therapies. Thus, early diagnosis of hypoxia with positron emission tomography (PET) radiotracer would be highly beneficial for management of malignant solid tumors with effective cancer therapy. YC-1 is a most promising candidate among several $HIF-1{\alpha}$ inhibitors. As an effort to develop a hypoxia imaging tool as a PET radiotracer, we designed and synthesized [$^{18}F$]DFYC based on potent derivative of YC-1 and performed preliminary in vitro cell uptake study. [$^{18}F$]DFYC showed a significant accumulation in SKBR-3 cells among other cancer cells, proving as a good lead to develop a hypoxic solid tumor such as breast cancer.

Numerical analysis of offshore monopile during repetitive lateral loading

  • Chong, Song-Hun;Shin, Ho-Sung;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • 제19권1호
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    • pp.79-91
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    • 2019
  • Renewed interest in the long-term pile foundations has been driven by the increase in offshore wind turbine installation to generate renewable energy. A monopile subjected to repetitive loads experiences an evolution of displacements, pile rotation, and stress redistribution along the embedded portion of the pile. However, it is not fully understood how the embedded pile interacts with the surrounding soil elements based on different pile geometries. This study investigates the long-term soil response around offshore monopiles using finite element method. The semi-empirical numerical approach is adopted to account for the fundamental features of volumetric strain (terminal void ratio) and shear strain (shakedown and ratcheting), the strain accumulation rate, and stress obliquity. The model is tested with different strain boundary conditions and stress obliquity by relaxing four model parameters. The parametric study includes pile diameter, embedded length, and moment arm distance from the surface. Numerical results indicate that different pile geometries produce a distinct evolution of lateral displacement and stress. In particular, the repetitive lateral load increases the global lateral load resistance. Further analysis provides insight into the propagation of the shear localization from the pile tip to the ground surface.

The effect of thalidomide on visceral fat pad mass and triglyceride concentration of the skeletal muscles in rats

  • Kim, Ki-Hoon;Choi, Chang-Bon;Kim, Jong-Yeon
    • Journal of Yeungnam Medical Science
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    • 제35권2호
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    • pp.213-218
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    • 2018
  • Background: Body fats, especially both of abdominal fat pad mass and skeletal muscle fat content, are inversely related to insulin action. Therefore, methods for decreasing visceral fat mass and muscle triglyceride content may be helpful for the prevention of insulin resistance. Methods: Thalidomide, used for its anti-angiogenic and anti-inflammatory properties, was administered to rats for 4 weeks. A 10% solution of thalidomide in dimethyl sulfoxide was injected daily into the peritoneal cavity as much as 100 mg/kg of body weight. Results: The total visceral fat pad mass in the thalidomide-treated group was 11% lower than in the control group. The size of adipocytes of the epididymal fat pad mass in the thalidomide-treated group was smaller than in the control group. The intraperitoneal thalidomide treatment increased triglyceride concentrations by 16% in the red muscle, but not in the white muscle. Conclusion: The results suggested that intraperitoneal thalidomide treatment inhibited abdominal fat accumulation, and that the free fatty acids in the blood were preferentially accumulated in the red muscle rather than in the white muscle.

The Role of Leptin in the Association between Obesity and Psoriasis

  • Hwang, Jaehyeon;Yoo, Ju Ah;Yoon, Hyungkee;Han, Taekyung;Yoon, Jongchan;An, Seoljun;Cho, Jae Youl;Lee, Jongsung
    • Biomolecules & Therapeutics
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    • 제29권1호
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    • pp.11-21
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    • 2021
  • Adipose tissue secretes many adipokines which contribute to various metabolic processes, such as blood pressure, glucose homeostasis, inflammation and angiogenesis. The biology of adipose tissue in an obese individual is abnormally altered in a manner that increases the body's vulnerability to immune diseases, such as psoriasis. Psoriasis is considered a chronic inflammatory skin disease which is closely associated with being overweight and obese. Additionally, secretion of leptin, a type of adipokine, increases dependently on adipose cell size and adipose accumulation. Likewise, high leptin levels also aggravate obesity via development of leptin resistance, suggesting that leptin and obesity are closely related. Leptin induction in psoriatic patients is mainly driven by the interleukin (IL)-23/helper T (Th) 17 axis pathway. Furthermore, leptin can have an effect on various types of immune cells such as T cells and dendritic cells. Here, we discuss the relationship between obesity and leptin expression as well as the linkage between effect of leptin on immune cells and psoriasis progression.

Distribution of Antibiotic-Resistant Bacteria in the Livestock Farm Environments

  • Kim, Youngji;Seo, Kun-Ho;Kim, Binn;Chon, Jung-Whan;Bae, Dongryeoul;Yim, Jin-Hyeok;Kim, Tae-Jin;Jeong, Dongkwan;Song, Kwang-Young
    • Journal of Dairy Science and Biotechnology
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    • 제39권1호
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    • pp.1-8
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    • 2021
  • The surroundings of livestock farms, including dairy farms, are known to be a major source of development and transmission of antibiotic-resistant bacteria. To control antibioticresistant bacteria in the livestock breeding environment, farms have installed livestock wastewater treatment facilities to treat wastewater before discharging the final effluent in nearby rivers or streams. These facilities have been known to serve as hotspots for inter-bacterial antibiotic-resistance gene transfer and extensively antibiotic-resistant bacteria, owing to the accumulation of various antibiotic-resistant bacteria from the livestock breeding environment. This review discusses antibiotic usage in livestock farming, including dairy farms, livestock wastewater treatment plants as hotspots for antibiotic resistant bacteria, and nonenteric gram-negative bacteria from wastewater treatment plants, and previous findings in literature.