• Journal of Life Science
• /
• v.18 no.4
• /
• pp.522-529
• /
• 2008

High-temperature requirement A2(HtrA2) has been known as a human homologue of bacterial HtrA that has a molecular chaperone function. HtrA2 is mitochondrial serine protease that plays a significant role in regulating the apoptosis; however, the physiological function of HtrA2 still remains elusive. To establish experimental system for the investigation of new insights into the function of HtrA2 in mammalian cells, we first obtained $HtrA2^{+/+}$ and $HtrA2^{-/-}$ MEF cells lines and identified those cells based on the expression pattern and subcellular localization of HtrA2, using immunoblot and biochemical assays. Additionally, we observed that the morphological characteristics of $HtrA2^{-/-}$ MEF cells are different form those of $HtrA2^{+/+}$ MEF cells, showing a rounded shape instead of a typical fibroblast-like shape. Growth rate of $HtrA2^{-/-}$ MEF cells was also 1.4-fold higher than that of $HtrA2^{+/+}$ MEF cells at 36 hours. Furthermore, we verified both MEF cell lines induced caspsase-dependent cell death in response to apoptotic stimuli such as heat shock, staurosporine, and rotenone. The relationship between HtrA2 and heat shock-induced cell death is the first demonstration of the research field of HtrA2. Our study suggests that those MEF cell lines are suitable reagents to further investigate the molecular mechanism by which HtrA2 regulates the balance between cell death and survival.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.2
• /
• pp.62-67
• /
• 2011

Launching tube is a kind of case to protect the guided weapons from external environments and conducted as a guide when they are fired. The guided weapons have been firmly kept at the launching tube and transferred, and would be separated at the required time when they are fired To meet the aim, it has been used explosive bolts which are reliable and efficient mechanical fastening devices having the special feature of a built-in release. The disadvantage of explosive bolt lies in that it is based on the high explosive effect of a pyrotechnic charge. When the explosive bolt is ignited, there are some bad effects; a flame, fragments and pyro-shock. Because of these bad effects there are many restriction to use bolt as joining devices to precision guided weapons. To solve these problems, the aim of the present work is to invent the ball-type separation bolt which is a pyrotechnically releasable mechanical linking device for two mechanical elements that does not suffer from such drawbacks. A standard pressure cartridge can moreover be easily integrated inside the device according to the present work and this with no modification to its structure. The present work was represented quantitatively the margin of separation safety and analysed separation mechanism in ball type separating bolt to perform the dynamic separation test.

• Applied Biological Chemistry
• /
• v.38 no.3
• /
• pp.212-217
• /
• 1995

This study was aimed for determining the biochemical mechanism of cold tolerance in crops and for searching the biochemical genetic marker related with cold tolerance by the analysis of isozyme pattern. We investigated various biochemical changes induced by the long-term cold acclimation in cold sensitive rape (B. napus) and in cold tolerant 'Sandongchae'(B. campestris) seedlings. The cold shock after long-term cold acclimation to B. napus and B. campestris greatly increased the activities of peroxidase 157% and 50% in root fraction and, 201% and 205% in hypocotyl, respectively. Simultaneously, the activity of superoxide dismutase was largely increased in hypocotyl fraction, too. Protein contents of hypocotyl fractions in B. napus and B. campestris were also increased by 11.4% and 57.8%, respectively. The band of pl 6.4 among peroxidase isozymes newly biosynthesized during long-term cold acclimation was emerged in the hypocotyl fraction of cold tolerant B. campestris as well as in the root of both species. From above and previous results, we presented a model of interconversions of molecular oxygen species due to the cold injury and biochemically inferred the mechanism of cold tolerance in crops.

• The Journal of Asian Finance, Economics and Business
• /
• v.6 no.3
• /
• pp.103-113
• /
• 2019

The effectiveness of monetary policy critically depends upon how well the transmission mechanism functions, so that the desired impact on output and inflation is achieved. The purpose of this paper is to study the transmission mechanism of monetary policy by analyzing the impact on inflation and output during multiple indicator regime (1998-99 to 2014) in an emerging economy-India. The Inflation Targeting Regime is also briefly outlined alongwith the impact on output and inflation. Using quarterly data for the period 1997 to 2017, the paper uses weighted average call money market rate as a proxy for the policy rate and evaluates the strength of the interest rate channel. We use a conventional Structural vector auto regression (SVAR) methodology to evaluate the efficacy and show the impluse response functions. Our results find that changes in the policy rate impact output growth steeply with a lag of about two quarters and the impact on inflation is maximized after three quarters. The study concludes that the monetary policy in India has a significant impact on output and inflation in the short-to-medium-run. After the policy shock, the fall in the output growth rate is of greater magnitude than the fall in inflation.

• The Journal of Korean Physical Therapy
• /
• v.13 no.2
• /
• pp.477-482
• /
• 2001

Until now, it has not been well known for Far-infrared(FIR) how to affect to the human body. We introduced and presumed the mechanism of FIR based on molecular biology in this study, as below. The human body is composed of proteins which get easily changed by a thermal factor (about 42 $^{\circ}$C over). FIR with low temperature can deeply penetrate on the human body composed things without troublesome, since FIR has effectively operated on the human body at low temperature (35-40 $^{\circ}$C). When FIR penetrated on the human body, it would inhibit the abnormal genes and cells expression, and then information of DNA and RNA would be reexpressed for arranging DNA and RNA abnormal state. As FIR's receptors in the body, it colud be presumed that N-glycosyl linkage of purine and deoxyribose, RNA splicing process, and heat shock protein.

• Carbon letters
• /
• v.4 no.3
• /
• pp.133-139
• /
• 2003

Carbon/carbon composites are ideal candidates for a number of aerospace applications including structural materials for advanced vehicles, leading edges, structures of re-entry and hypersonic vehicles and propulsion systems. One serious defect for such application of the carbon/carbon composites is their poor oxidation resistance in high temperature oxidizing environments. SiC coating was employed to protect the composites from oxidation. It is mechanically and chemically stable under extreme thermal and oxidative environments, provides good adhesion to the substrate, and offers good thermal shock resistance. The SiC layer on the nozzle machined from the carbon/carbon composites was formed by pack-cementation method. Then, erosion characteristic of SiC coated carbon/carbon nozzle was examined by combustion test using a liquid rocket motor. The erosion rates were measured as function of combustion pressure, ratio of oxygen to fuel, combustion time, density of the composites and geometry of reinforced carbon fibre in the composites. The morphology change of the composites after combustion test was investigated using SEM and erosion mechanism also was discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.4
• /
• pp.16-21
• /
• 2011

This paper described an analysis of dynamic mechanism for the industrial two-step folding automatic door using commercial software packages. Two modeling types of operating on the guide rail, the sliding one and the rolling, were adopted to investigate effects of impact force when the door ascends the guide rail. The magnitude of impact force was found very peaklike large over an initial duration of the door's moving up. The amount of damping coefficient for alleviating this shock was controlled to such a moderate degree that the operating conditions can be obtained for the purpose of design. Moreover the behavior of both dynamic stress and deformation were observed for acquirement of structural reliabilities of the combined guide rail and rolling mechanism. This research will be a very useful tool in the near future for the dynamic analysis of the multi-step folding automatic door.

• BMB Reports
• /
• v.38 no.3
• /
• pp.266-274
• /
• 2005

High temperature requirement A (HtrA) and its homologues constitute the HtrA familiy proteins, a group of heat shock-induced serine proteases. Bacterial HtrA proteins perform crucial functions with regard to protein quality control in the periplasmic space, functioning as both molecular chaperones and proteases. In contrast to other bacterial quality control proteins, including ClpXP, ClpAP, and HslUV, HtrA proteins contain no regulatory components or ATP binding domains. Thus, they are commonly referred to as ATP-independent chaperone proteases. Whereas the function of ATP-dependent chaperone-proteases is regulated by ATP hydrolysis, HtrA exhibits a PDZ domain and a temperature-dependent switch mechanism, which effects the change in its function from molecular chaperone to protease. This mechanism is also related to substrate recognition and the fine control of its function. Structural and biochemical analyses of the three HtrA proteins, DegP, DegQ, and DegS, have provided us with clues as to the functional regulation of HtrA proteins, as well as their roles in protein quality control at atomic scales. The objective of this brief review is to discuss some of the recent studies which have been conducted regarding the structure and function of these HtrA proteins, and to compare their roles in the context of protein quality control.

• East Asian Economic Review
• /
• v.24 no.4
• /
• pp.313-336
• /
• 2020

In this paper, I review evidence on changing global specialization in labor-intensive exporting. Production of apparel, footwear, furniture, and related products are how many low-income countries first enter export manufacturing. Just as China's rise as a powerhouse in these goods supplanted a role previously occupied by the East Asian Tigers, the world may again be on the cusp of significant change in where labor-intensive goods are produced. China's prowess in these sectors peaked in the early 2010s; its share in their global exports, while still substantial, is now in decline. Mechanisms through which the global economy may adjust to China's graduation into more technologically sophisticated activities include expanded labor-intensive export production in other emerging economies and labor-saving technological change in products currently heavily reliant on less-educated labor. Available evidence suggests that the first mechanism is operating slowly and the second hardly at all. As a third mechanism, China may in part replace itself by moving labor-heavy factories out of densely populated and expensive coastal cities and into the country's interior. Such a transition, though still in its infancy, would mirror the decentralization of manufacturing production in the U.S. and Europe, which occurred after World War II.

• Current Optics and Photonics
• /
• v.7 no.6
• /
• pp.714-720
• /
• 2023

Laser cleaning has the advantages of environmental protection, precision, and high efficiency, and has good prospects for application in removing oxide films on the surface of aluminum alloy. This paper discusses the cleaning threshold and cleaning mechanism of aluminum alloy surface oxide film. A nanosecond pulsed laser was used to remove a 5-㎛-thick oxide film from the surface of 7A04 aluminum alloy, and the target surface temperature and cleaning depth were simulated. The effects of different laser energy densities on the surface morphology of the aluminum alloy were analyzed, and the plasma motion process was recorded using a high-speed camera. The temperature measurement results of the experiment are close to the simulation results. The results show that the laser cleaning of aluminum alloy oxide film is mainly based on the vaporization mechanism and the shock wave generated by the explosion.