• Title/Summary/Keyword: Central mechanism

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Primary Role of Posterior Hypothalamic Cholinergic Receptors in Central Regulation of Blood Pressure and Heart Rate in Rats (중추에서 혈압과 심박수 조절에 관여하는 후시상하부 콜린성 수용체의 일차적인 역할)

  • Kim, Seong-Yun;Sung, Ki-Wug;Koh, Hyun-Chul;Lee, Sang-Bok
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.6
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    • pp.639-645
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    • 1997
  • The purpose of the present study is to determine the role of muscarinic cholinergic receptors of posterior hypothalamus in the central blood pressure regulation when respiration is controlled. In anesthetized and artificially ventilated rats, vasodepressor response was evoked by injection of L-glutamate(10 nmol) neuroexcitatory amino acid into the posterior hypothalamic area. The injection of $carbachol(0.5{\sim}8\;nmol)$ into the same area induced dose-dependent vasodepressor and bradycardic responses. Pretreatment with atropine(4 nmol) completely blocked the vasodepressor response to carbachol(2 nmol). In contrast, in spontaneously breathing rats, the injection of carbachol(8 nmol) into the posterior hypothalamic area induced the vasopressor and tachycardic responses. These results suggest that the muscarinic cholinergic receptors in the posterior hypothalamic area primarily play an inhibitory role in the central regulation of blood pressure and heart rate.

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Cold Ethanol Fractionation and Heat Inactivation of Hepatitis A Virus During Manufacture of Albumin from Human Plasma

  • Kim, In-Seop;Park, Yong-Woon;Lee, Sung-Rae;Sung, Hark-Mo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.1
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    • pp.65-68
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    • 2004
  • The purpose of the present study was to examine the efficacy and mechanism of fraction IV cold ethanol fractionation and pasteurization (60$^{\circ}C$ heat treatment for 10 h), involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and the amount of virus in each fraction then quantified using a 50% tissue culture infectious dose (TCID$\_$50/). HAV was effectively partitioned from albumin during the fraction IV cold ethanol fractionation with a log reduction factor of 3.43. Pasteurization was also found to be a robust and effective step in inactivating HAV, where the titers were reduced from an initial titer of 7.60 log TCID$\_$50/ to undetectable levels within 5 h of treatment. The log reduction factor achieved during pasteurization was $\geq$4.76. Therefore, the current results indicate that the production process for albumin has sufficient HAV reducing capacity to achieve a high margin of virus safety.

Assembly Mechanism of [$Fe_2S_2$] Cluster in Ferredoxin from Acidithiobacillus ferrooxidans

  • Chen, Qian;Mo, Hongyu;Tang, Lin;Du, Juan;Qin, Fang;Zeng, Jia
    • Journal of Microbiology and Biotechnology
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    • v.21 no.2
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    • pp.124-128
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    • 2011
  • Ferredoxin is a typical iron-sulfur protein that is ubiquitous in biological redox systems. This study investigates the in vitro assembly of a [$Fe_2S_2$] cluster in the ferredoxin from Acidithiobacillus ferrooxidans in the presence of three scaffold proteins: IscA, IscS, and IscU. The spectra and MALDI-TOF MS results for the reconstituted ferredoxin confirm that the iron-sulfur cluster was correctly assembled in the protein. The inactivation of cysteine desulfurase by L-allylglycine completely blocked any [$Fe_2S_2$] cluster assembly in the ferredoxin in E. coli, confirming that cysteine desulfurase is an essential component for iron-sulfur cluster assembly. The present results also provide strong evidence that [$Fe_2S_2$] cluster assembly in ferredoxin follows the AUS pathway.

Stability charts and reinforcement with piles in 3D nonhomogeneous and anisotropic soil slope

  • Xu, Jingshu;Li, Yongxin;Yang, Xiaoli
    • Geomechanics and Engineering
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    • v.14 no.1
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    • pp.71-81
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    • 2018
  • Soils are mostly nonhomogeneous and anisotropic in nature. In this study, nonhomogeneity and anisotropy of soil are taken into consideration by assuming that the cohesion increases with depth linearly and also varies with respect to direction at a particular point. A three-dimensional rotational failure mechanism is adopted, and then a three-dimensional stability analysis of slope is carried out with the failure surface in the shape of a curvilinear cone in virtue of the limit analysis method. A quasistatic approach is used to develop stability charts in nonhomogeneous and anisotropic soils. One can easily read the safety factors from the charts without the need for iterative procedures for safety factors calculation. The charts are of practical importance to prevent a plane failure in excavation slope whether it is physically constrained or not. Then the most suitable location of piles within the reinforced slope in nonhomogeneous and anisotropic soils is explored, as well as the interactions of nonhomogeneous and anisotropic coefficients on pile reinforcement effects. The results indicate that piles are more effective when they are located between the middle and the crest of the slope, and the nonhomogeneous coefficient as well as the anisotropic coefficient will not only influence the most suitable location for piles but also affect the calculated safety factor of existing reinforced slope. In addition, the two coefficients will interact with each other on the effect on slope reinforcement.

Development of a Novel, Anti-idiotypic Monoclonal Anti-prolactin Antibody That Mimics the Physiological Functions of Prolactin

  • Wang, Meng;Zhang, Dian-Cai;Wang, Shen-Tian;Li, Ming-Long
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.4
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    • pp.571-579
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    • 2016
  • In this work, we prepared a panel of monoclonal anti-idiotypic antibodies to ovine prolactin (oPRL) by the hybridoma technique. Among these antibodies, one anti-idotypic antibody (designated B7) was chosen for further characterization by a series of experiments. We first demonstrated that B7 behaved as a typical $Ab2{\beta}$ based on a series of enzyme-linked immunosorbent assays. Subsequently, the results of a competitive receptor-binding assay confirmed that B7 could specifically bind to the prolactin receptor (PRLR) expressed on target cells. Finally, we examined its biological activities in CHO-PRLR and Nb2 cells and observed that B7 could activate Janus kinase 2-signal transducer and activator of transcription signalling in CHO-PRLR and Nb2 cells and induce BaF3 proliferation. The present study suggests that i) B7 can serve as a PRLR agonist or PRL mimic and has potential applications in regulating mammary gland development, milk production and maintenance of lactation in domestic animals and ii) B7 may be a biological reagent that can be used to explore the mechanism of PRLR-mediated intracellular signalling.

Adverse Drug Reaction of Chinese Herbal Injection: Focusing on the Anaphylaxis Reaction (중약주사제의 약물유해반응: 아나필락시스 반응을 중심으로)

  • Jeung, Chang-woon;Jeon, Sun-woo;Jo, Hee-Geun
    • Journal of Korean Medicine Rehabilitation
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    • v.30 no.4
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    • pp.133-142
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    • 2020
  • Objectives Studies on Chinese herbal injections are increasing. But, its safety are still not well reported. We have reviewed the literature related to the safety of Chinese herbal injection, especially those related to anaphylaxis. Methods The PubMed database was used to select the literatures related to anaphylaxis in China and to study the quality control and safety of Chinese herbal injection. Results Chinese herbal injection is a major traditional medical treatment in China, but it is the cause of adverse drug reactions including anaphylaxis. In order to solve this problem, various proposals have been made to identify the pharmacological and chemical causes of major side effects and to use them safely clinically. In addition, various researches have been conducted from preclinical to postmarketing surveillance to secure the safety of Chinese herbal injection. Based on this, it was found that various efforts are needed to secure the safety of bee sting needles. Conclusion In order to secure the safety of chinese herbal injections, it is necessary to identify the main mechanism of action and the pharmacological components contributing to it, and to develop a standardized formulation based on this. In addition, institutional pharmacovigilance is required.

De-soda Process Using Silica for Fabrication of Low Soda Alumina Powder

  • Park, Sang-Chun;Kim, Dae-Woong;Heo, In-Woong;Lee, Sang-Jin
    • Journal of the Korean Ceramic Society
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    • v.52 no.3
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    • pp.192-196
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    • 2015
  • Low soda alumina powder was fabricated using silica (${\alpha}$-quartz) as an agent for removing soda components in the alumina. Quartz powder 2 mm in size was added to aluminum hydroxide obtained through the Bayer process, and then the mixture was heated at various temperatures. Finally, the heat-treated powders were sieved for classification. In this study, the effects of the quartz amount and heating temperature on the mechanism of removing soda were examined. A minimum soda content of 0.005 wt% was observed at the conditions of 15 wt% quartz (based on $Al(OH)_3$ amount) heat-treated at $1600^{\circ}C$ for 8 h. The soda components, such as $Na_2O$, NaOH, and $Na_2CO_3$, in alumina were ionized and activated at high temperature, and this facilitated the reaction with quartz silica and alumina producing nepheline. The advantages of using quartz include low iron content and low cost in comparison with the conventional de-soda process using chamotte, another silicate mineral.

A Review on the Effects of Earthborne Vibrations and the Mitigation Measures

  • Nam, Boo Hyun;Kim, Jinyoung;An, Jinwoo;Kim, Bumjoo
    • International Journal of Railway
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    • v.6 no.3
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    • pp.95-106
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    • 2013
  • Earthborne vibrations are induced by construction operation such as pile driving, roadbed compaction, and blasting and also by transit activities such as truck and trains. The earthborne vibration creates the stress waves traveling outward from the source and can structurally damage nearby buildings and structures in the forms of direct damage to structure and damage due to dynamic settlement. The wave propagation characteristics depends on impact or vibration energy, distance from the source, and soil characteristics. The aim of this paper is to provide a comprehensive review on the mechanistic of earthborne vibration and the current practice of vibration control and mitigation measures. The paper describes the state of knowledge in the areas of: (1) mechanics of earthborne vibration, (2) damage mechanism by earthborne vibration, (3) calculation, prediction of ground vibration, (4) the criteria of vibration limits, (5) vibration mitigation measures and their performance, and (6) the current practice of vibration control and mitigation measures.

Safety Analysis of APR+ PAFS for CDF Evaluation (노심손상빈도 평가를 위한 APR+ PAFS의 안전 해석)

  • Kang, Sang Hee;Moon, Ho Rim;Park, Young Seop
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.123-128
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    • 2013
  • The Advanced Power Reactor Plus(APR+), which is a GEN III+ reactor based on the APR1400, is being developed in Korea. In order to enhance the safety of the APR+, a passive auxiliary feedwater system(PAFS) has been adopted in the APR+. The PAFS replaces the conventional active auxiliary feedwater system(AFWS) by introducing a natural driving force mechanism while maintaining the system function of cooling the primary side and removing the decay heat. As the PAFS completely replaces the conventional AFWS, it is required to verify the cooling capacity of PAFS for the core damage frequency(CDF) evaluation. For this reason, this paper discusses the cooling performance of the PAFS during transient accidents. The test case and scenarios were picked from the result of the sensitivity analysis in APR+ Probabilistic Safety Assessment(PSA). The analysis was performed by the best estimate thermal-hydraulic code, RELAP5/.MOD3.3. This study shows that the plant maintains the stable state without the core damages under the given test scenarios. The results of PSA considering this analysis' results shows that the CDF values are decreased. The analysis results can be used for more realistic and accurate performance of a PSA.

Inheritance of Resistance to Nuclear Polyhedrosis Virus in Silkworm, Bombyx mori

  • Sen, Ratna;Ashwath, S.K.;Datta, R.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.3 no.2
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    • pp.187-190
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    • 2001
  • Inheritance pattern of resistance to Bombyx mori nuclear polyhedrosis virus (BmNPV) was studied in an Indian silkworm stock TX by single back-cross test method. The resistant parent [TX], susceptible parent [HM], their Fl, F2, and Fl progeny back-crossed to TX [BC(R)] and HM [BC(S)] were inoculated per os with a fixed concentration of BmNPV($0.5{\times}10^{th} PIB/ml$) on the first day of second stadium. The cumulative mortality was recorded until day $10^{\times}$ post-inoculation. The results show that the resistance to BmNPV in TX fellow mono Mendelian inheritance pattern. The resistance dominated over the susceptibility at Fl. At F2, the resistant and susceptible offspring segregated in 3:1 ratio whereas at BC(S), the resistant and susceptible offspring segregated in 1:1 ratio. The response of BC(R) was more or less like the resistant parent TX which confirms the involvement of a major dominant gene conferring resistance to BmNPV in TX. The possible mechanism of inheritance of resistance in TX is discussed.

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