• Title/Summary/Keyword: Induction Motor

Search Result 2,727, Processing Time 0.034 seconds

Human Embryonic Stem Cells Co-Transfected with Tyrosine Hydroxylase and GTP Cyclohydrolase I Relieve Symptomatic Motor Behavior in a Rat Model of Parkinson′s Disease

  • Kil, Kwang-Soo;Lee, Chang-Hyun;Shin, Hyun-Ah;Cho, Hwang-Yoon;Yoon, Ji-Yeon;Lee, Gun-Soup;Lee, Young-Jae;Kim, Eun-Young;Park, Se-Pill
    • Proceedings of the Korean Society of Developmental Biology Conference
    • /
    • 2003.10a
    • /
    • pp.101-101
    • /
    • 2003
  • Main strategy for a treatment of Parkinson's disease (PD), due to a progressive degeneration of dopaminergic neurons, is a pharmaceutical supplement of dopamine derivatives or ceil replacement therapy. Both of these protocols have pros and cons; former exhibiting a dramatic relief but causing a severe side effects on long-term prescription and latter also having a proven effectiveness but having availability and ethical problems Embryonic stem (ES) cells have several characteristics suitable for this purpose. To investigate a possibility of using ES cells as a carrier of therapeutic gene(s), human ES (hES, MB03) cells were transfected with cDNAs coding for tyrosine hydroxylase (TH) in pcDNA3.1 (+) and the transfectants were selected using neomycin (250 $\mu /ml$). Expression of TH being confirmed, two of the positive clone (MBTH2 & 8) were second transfected with GTP cyclohydrolase 1 (GTPCH 1) in pcDNA3.1 (+)-hyg followed by selection with hygromycin-B (150 $\mu /ml$) and RT-PCR confirmation. By immune-cytochemistry, these genetically modified but undifferentiated dual drug-resistant cells were found to express few of the neuronal markers, such as NF200, $\beta$-tubulin, and MAP2 as well as astroglial marker GFAP. This results suggest that over-production of BH4 by ectopically expressed GTPCH I may be involved in the induction of those markers. Transplantation of the cells into striatum of 6-OHDA- denervated PD animal model relieved symptomatic rotational behaviors of the animals. Immunohistochemical analyses showed the presence of human cells within the striatum of the recipients. These results suggest a possibility of using hES cells as a carrier of therapeutic gene(s).

  • PDF

Secondary Science Teachers' Perception about and Actual Use of Visual Representations in the Teaching of Electromagnetism (중등 전자기 수업에서 사용하는 시각적 표상에 대한 교사 인식 및 활용 실태)

  • Yoon, Hye-Gyoung;Jo, Kwanghee;Jho, Hunkoog
    • Journal of The Korean Association For Science Education
    • /
    • v.37 no.2
    • /
    • pp.253-262
    • /
    • 2017
  • This study aims at investigating the perceptions of science teachers about the role of visual representations in the teaching of electromagnetism, and finding out how science teachers use visual representations in their teaching of electromagnetism and the difficulties they experience in dealing with those representations. A total of 121 science teachers responded to the online survey. The results showed that most of the teachers agreed to the significance of using visual representations in the classroom but regarded their role as means of simply delivering science knowledge rather than constructing or generating knowledge. For the three visual representations widely used in teaching of electromagnetism in secondary schools (electrostatic induction on electroscope, magnetic field around current carrying wire, structure and principle of electric motor), the teachers preferred teacher-centered use of visual representations rather than student-centered and teacher's construction of representations were the most frequent among four types of use; interpretation, construction, application, and evaluation. The difficulties of teaching with these three visual representations were categorized into several factors; teachers, students, the characteristics of the representations, and lack of resources and classroom environment. Teachers' limited perceptions about the role of visual representations were associated with the ways of using visual representations in their teaching. Implications for the effective use of visual representations for science learning and teaching were discussed.

Histopathologic Features and CD5+ B-lymphocyte Expression in the Experimental Allergic Neuritis (실험적 자가면역성 말초신경염에서의 조직병리적 병변 및 CD5+ B-림프구의 발현)

  • Cho, Joong-Yang;Choi, Won-Jun;Kim, Sung-Hun;Sung, Jung-Joon;Kim, Ho-Jin;Park, Kyung-Seok;Choi, Ki-Young;Kim, Hyun-Jung;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
    • /
    • v.1 no.2
    • /
    • pp.91-98
    • /
    • 1999
  • Background : The pathogenesis of acute inflammatory demyelinating polyradiculoneuropathy (AIDP), Guillain Barre syndrome (GBS) is not clear, but it has been known that the immune mechanisms play an important role. Authors performed this study to establish an animal model of experimental allergic neuritis (EAN) by immunizing the myelin components of peripheral nerves and to understand the electrophysiological and histopathological features as well as the ${CD_5}^+$ B-lymphocyte changes in peripheral bloods in the EAN models. Methods : Lewis rats weighing 150-200 gm were injected subcutaneously in soles two times with total myelin, P0, P1, or P2 proteins purified from the bovine cauda eguina. The EAN induction was assessed by evaluating clinical manifestations. The electrophysiological and histopathological features were studied as routine methods. The ${CD_5}^+$ Blymphocytes were double stained using monoclonal FITC conjugated anti-rat CD45RA and R-PE conjugated anti-rat ${CD_5}^+$ antibodies and calculated using a fluorescence activated cell sorter (FACS). Results : The EAN animal models were established. In two out of five, in one out of two, in none out of three, and in none out of one Lewis rats injected with purified total myelin, P0, P1, P2 proteins respectively, They showed slow spontaneous motor activity and weak resistance against pulling back by tails. The typical electrophysiological and histologic findings in total protein and P0 induced EAN animal models were the decreased conduction velocity, the decreased compound muscle action potential (CMAP) amplitude and the dispersion phenomenon. The perivascular infiltrates of lymphocytes with focal demyelinating process were found in light microscopy. The ${CD_5}^+$ B-lymphocyte expression in three EANs were 2.38%, 3.50% 2.50%, which were not significantly increased, compared with those in normal controls. Conclusion : The EAN animal models were successfully established by injecting the total myelin and P0 myelin and they showed electrophysiological and histological features typical of demyelinating process. However they did not show an increased expression of ${CD_5}^+$ B-lymphocyte in peripheral bloods which could be indirect evidence of humoral autoimmunity.

  • PDF

Experimental Study on the Natural Convective Heat Transfer Characteristics of Ferrofluid for Concentric Annuli under Rotating Magnetic Field (회전수 및 자기장강도 변화에 따른 이중원관내 자성유체의 자연대류 열전달 특성에 관한 실험적 연구)

  • Kim, Hyung-Jin;Seo, Jae-Hyeong;Kim, Dae-Wan;Lee, Moo-Yeon;Seo, Lee-Soo
    • Journal of the Korean Magnetics Society
    • /
    • v.23 no.2
    • /
    • pp.77-81
    • /
    • 2013
  • The objective of this study is experimentally to investigate natural convective heat transfer characteristics of the ferrofluid for a concentric annuli under rotating magnetic field with variations of the revolution and the magnetic field strength. The rotating magnetic field was provided by induction motor with 6 poles and 3 phases and the revolution and the magnetic field strength were controlled by an inverter driver and a voltage meter, respectively. Temperatures of the inner pipe and the outer pipe in the tested concentric annuli were maintained at $30^{\circ}C$ and $25^{\circ}C$, respectively, during the test and the direction of the rotating magnetic field was a counterclockwise. As a result, the natural convective heat transfer characteristics of the ferrofluid for a concentric annuli were increased with the rise of the revolution and magnetic field strength due to the increased heat dissipation between hot side and cold side of the concentric annuli.

Acute postoperative myelopathy caused by spontaneous developed cervical disc herniation: Case report & literature review (수술후 자연발생 경추간판탈출에 의한 척수병증: 증례보고 및 문헌고찰)

  • Lee, Jeong-Woo;Lee, Keun Hyeong;Lee, Ju-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.10
    • /
    • pp.303-308
    • /
    • 2019
  • Non-traumatic acute myelopathy caused by cervical disc herniation is rare. To date, no case has been reported to be caused by extrusion cervical disc herniation, unrelated to patient posture during surgery. Here, we report the case of a 65-year-old male patient with cervical myelopathy who underwent subsequent arthroscopic rotator cuff surgery under general anesthesia; non-cervical spine surgery. Ed. Notes: I am unable to understand the insertion of the highlighted phrase. Please delete if not required, or revise the sentence appropriately. Patient showed acute postoperative tetraplegia in spite of optimal anesthetic management. He showed no limitation of neck movement at pre-operative airway evaluation, and had no history of trauma to the cervical spine. During surgery, there had been no overextension or twisting of the neck, including at the time of anesthetic induction by tracheal intubation. However, cervical disc herniation causing spinal canal cord compression was detected in the postoperative magnetic resonance imaging, which probably resulted in tetraplegia of the patient. Motor and sensory functions were recovered after 21 days of conservative treatment, including steroid pulse intravenous therapy without any surgical intervention. In this report, the disease is described after reviewing other reported cases; furthermore, we also discuss the pathophysiology of the disease. Based on our report, we propose that under general anesthesia, clinicians should pay attention to the possibility of pre-existing cervical disease, even in non-cervical spine surgeries of geriatric patients.

A Novel Pyrazolo[3,4-d]pyrimidine Induces Heme Oxygenase-1 and Exerts Anti-Inflammatory and Neuroprotective Effects

  • Lee, Ji Ae;Kwon, Young-Won;Kim, Hye Ri;Shin, Nari;Son, Hyo Jin;Cheong, Chan Seong;Kim, Dong Jin;Hwang, Onyou
    • Molecules and Cells
    • /
    • v.45 no.3
    • /
    • pp.134-147
    • /
    • 2022
  • The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinetreated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress-and inflammation-related neurodegenerative disorders such as Parkinson's disease.

The Trend Analysis of Propulsion System for Railway Vehicle Using Patent Analysis (특허분석을 통한 철도차량용 추진제어장치 기술 분석)

  • Han, Young-Jae;Lee, Su-Gil;Park, Chan-Kyoung;Kim, Young-Guk;Bae, Chang-Han
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.5
    • /
    • pp.131-138
    • /
    • 2018
  • In this study, we investigated the trend of technological development in major countries related to the propulsion equipment of railway vehicles. The propulsion system is the main equipment of electric vehicles. A lot of time and investment are required in order to ensure the development of technology. Therefore, developed countries have maximized their effort to develop technologies with safety, reliability, and convenience of maintenance. They have also done their utmost to prevent technology transfer to other countries after the development of new technologies. For example, Toshiba of Japan developed a new 3,300V/1,500 A class IGBT power device, but was reluctant to export it to foreign countries in order to protect this technology. In this study, we analyzed the patents applied for related to propulsion control systems and presented the direction of development during the technical development of these systems. The patent analysis of the core technologies was conducted using the Thomson Innovation DB. We examined the number of patents applied for by country, year and major applicant. As a result of the analysis, it was found that the proportion of patent applications per country was in the order of China, 48%, Europe 16.6%, and the United States 14.9%. The patent situation of the top 10 principal applicants revealed that (the top three were?) ABB 14%, GE 13%, and CRRC 12%. At the same time, we also conducted a qualitative analysis of the level of technical development by evaluating such factors as the influence index, quotation, market securing power and citation. Based on the result of the patent analysis, we presented the direction of technical development of the propulsion control equipment of railway vehicles. Based on the analysis results, it was found that domestic applicants considerably reduced their efforts to protect their patents from foreign companies. Nowadays, most of the electric motors used in Korea are induction motors. In advanced countries, permanent magnet electric motors are employed in new railway lines. Therefore, intensive investment is needed in new developments.