• Plant Biotechnology Reports
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• v.4 no.1
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• pp.37-48
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• 2010

[ ${\Delta}^1$ ]pyrroline-5-carboxylate synthetase (P5CS) is a proline biosynthetic pathway enzyme and is known for conferring enhanced salt and drought stress in transgenics carrying this gene in a variety of plant species; however, the wild-type P5CS is subjected to feedback control. Therefore, in the present study, we used a mutagenized version of this osmoregulatory gene-P5CSF129A, which is not subjected to feedback control, for producing transgenic indica rice plants of cultivar Karjat-3 via Agrobacterium tumefaciens. We have used two types of explants for this purpose, namely mature embryo-derived callus and shoot apices. Various parameters for transformation were optimized including antibiotic concentration for selection, duration of cocultivation, addition of phenolic compound, and bacterial culture density. The resultant primary transgenic plants showed more enhanced proline accumulation than their non-transformed counterparts. This proline level was particularly enhanced in the transgenic plants of next generation ($T_1$) under 150 mM NaCl stress. The higher proline level shown by transgenic plants was associated with better biomass production and growth performance under salt stress and lower extent of lipid peroxidation, indicating that overproduction of proline may have a role in counteracting the negative effect of salt stress and higher maintenance of cellular integrity and basic physiological processes under stress.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.189-202
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• 1985

Enhanced activity of renin-angiotensin-aldosterone system has been suggested as a cause of the high blood pressure in certain forms of experimental hypertension. In spontaneously hypertensive rats, however, increased activity of the system has not been found, and even suppressed renin angiotensin system has been reported in the spontaneously hypertensive rat. In the present experiments it was attempted to explore the possible alteration of the short loop negative feedback control in the hypertensive rat. Experiments have been done in the anesthetized spontaneously hypertensive rats(SHR) as well as in normotensive Wistar and Sprague Dawley rats as control. Responses of the plasma renin activity to the intravenous L-isoproterenol were dose dependent, in both SHR and normotensive control rats. Hypotensive responses to smaller do sea of L-isoproterenol were more accentuated in SHR than in the normotensive control rats. Angiotensin If given intravenously suppressed plasma renin activity in a dose dependent fashion in both groups. However, these suppressive responses were significantly attenuated in SHR as compared with the normotensive control rats. Treatment with angiotensin I-converting enzyme inhibitor did not correct the attenuated responses of the plasma renin activity to angiotensin II in SHR. Intravenous infusion of arginine vasopressin also produced a dose-dependent suppression of plasma renin activity in both groups. The responses to arginine vasopressin were also significantly attenuated to the normotensive control rats. In the sodium-depleted SHR, arginine vasopressin did not suppress plasma renin activity, whereas the suppressive responses to arginine vasopressin in the normotensive control rats were not different from the untreated control rats. These data suggest that there may be a derangement in the short loop negative feedback control of the renin-angiotensin system in spontaneously hypertensive rat.

• BMB Reports
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• v.50 no.5
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• pp.235-236
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• 2017

The circadian clock is an internal system that is synchronized by external stimuli, such as light and temperature, and influences various physiological and developmental processes in living organisms. In the model plant Arabidopsis, transcriptional, translational and post-translational processes are interlocked by feedback loops among morning- and evening-phased genes. In a post-translational loop, plant-specific single-gene encoded GIGANTEA (GI) stabilize the F-box protein ZEITLUPE (ZTL), driving the targeted-proteasomal degradation of TIMING OF CAB EXPRESSION 1 (TOC1) and PSEUDO-RESPONSE REGULATOR 5 (PRR5). Inherent to this, we demonstrate the novel biochemical function of GI as a chaperone and/or co-chaperone of Heat-Shock Protein 90 (HSP90). GI prevents ZTL degradation as a chaperone and facilitates ZTL maturation together with HSP90/HSP70, enhancing ZTL activity in vitro and in planta. GI is known to be involved in a wide range of physiology and development as well as abiotic stress responses in plants, but it could also interact with diverse client proteins to increase protein maturation. Our results provide evidence that GI helps proteostasis of ZTL by acting as a chaperone and a co-chaperone of HSP90 for proper functioning of the Arabidopsis circadian clock.

• Journal of the Ergonomics Society of Korea
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• v.16 no.1
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• pp.107-117
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• 1997

It is necessary to evaluate HMI inaspects of human factors in the design stage of MMIS(man machine interface system) and feedback the result of evaluation because operators performance is mainly influenced by the HMI. Therefore, the MMIS design should be reflected the operators psychological, behavioral and physiological characteristics in the interaction with human machine interface(HMI) in order to improve the safety and availability of the MMIS of a nuclear power plant(NPP) by reduction of human error. The development of human factors experimental evaluation techniques and integrated test facility(ITF) for the human factors evaluation become an important research field to resolve hi,am factors issues on the design of an advanced control room(ACR). We developed am ITF, which is aimed to experiment with the design of the ACR and the human machine interaction as it relates to the control of NPP. This paper presents the development of an ITF that consists of three rooms such as main test room(MTR), supporting test room(STR) and experiment control room(ECR). And, the ITF has a various facilities such as a human machine simulator(HMS), experimental measurement systems and data analysis and experiment evaluation supporting system(DAEXESS). The HMS consists of full-scope simulation model of Korean standard NPP and advanced HMI based on visual display nits (VDUS) such as touch color CRT, large scale display panel(LSDP), flat panel display unit and so on.

• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.59-64
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• 2013

Auxin is a key plant hormone which regulates overall plant growth development. A number of researches to investigate auxin signaling identified three major classes of early auxin response genes: AUX/IAA, GH3 and SMALL AUXIN UP RNA (SAUR). Among these genes, in planta functions of SAUR gene family are largely ambiguous, while both AUX/IAA and GH3 genes are analyzed to mediate negative feedback on auxin response. SAUR genes encode small plant-specific proteins. SAUR gene products are highly unstable and transiently expressed in the tissue- and developmental-specific manners in response to auxin and various environmental stimuli. In the decades, molecular and genetic approaches to elucidate in planta functions of SAURs have been hampered by several factors such as the unstable molecular features and functional redundancy among them. However, a series of recent studies focusing on several subgroups of SAUR gene family made significant progress in our understanding of its biochemical and physiological functions. These works suggest that many SAUR proteins mainly regulate auxin-related cell expansion and auxin transport. In this review, the recent progress in SAUR research and prospects for crop improvement through its genetic manipulation are discussed.

• Physical Therapy Rehabilitation Science
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• v.12 no.3
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• pp.251-258
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• 2023

Objective: The practice of breathing exercises involves altering the depth and frequency of respiration. Strengthening respiratory muscles plays a crucial role in maintaining overall health and well-being. The efficiency of the respiratory system affects not only physical activity but also various physiological processes including cardiovascular health, lung function, and cognitive abilities. The study evaluated the reliability of the developed device for inspiratory/expiratory training using pressure sensors and Bluetooth connectivity with a smartphone application. Design: Design & development research Methods: The research methodology involved connecting a custom-made respiratory sensor to an IMT-PEP BIC Breath device. Various pressure conditions were measured, and statistical analyses were performed to assess reliability and consistency. Results showed high Intraclass Coefficient Correlation (ICC) values for both inspiratory and expiratory pressures, indicating strong test-retest reliability. The device was designed for ease of use and wireless monitoring through a smartphone app. Results: This study conducted at expiratory pressure confirmed the proper operation of the IMT/PEP breathing trainer at the specified pressure setting in the product. The pressure sensor demonstrated high test-retest reliability with an ICC value of 0.999 for both expiratory and inspiratory pressure measurements. Conclusions: The developed respiratory training device measured and monitored inspiratory and expiratory pressures, demonstrating its reliability for respiratory training. The system could be utilized to record training frequency and intensity, providing potential benefits for patients requiring respiratory interventions. Further research is needed to assess the full potential of the device in diverse populations and applications.

• The korean journal of orthodontics
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• v.41 no.1
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• pp.6-15
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• 2011

Objective: The aim of this study was to evaluate the biomechanical aspects of peri-implant bone upon root contact of orthodontic microimplant. Methods: Axisymmetric finite element modeling scheme was used to analyze the compressive strength of the orthodontic microimplant (Absoanchor SH1312-7, Dentos Inc., Daegu, Korea) placed into inter-radicular bone covered by 1 mm thick cortical bone, with its apical tip contacting adjacent root surface. A stepwise analysis technique was adopted to simulate the response of peri-implant bone. Areas of the bone that were subject to higher stresses than the maximum compressive strength (in case of cancellous bone) or threshold stress of 54.8MPa, which was assumed to impair the physiological remodeling of cortical bone, were removed from the FE mesh in a stepwise manner. For comparison, a control model was analyzed which simulated normal orthodontic force of 5 N at the head of the microimplant. Results: Stresses in cancellous bone were high enough to cause mechanical failure across its entire thickness. Stresses in cortical bone were more likely to cause resorptive bone remodeling than mechanical failure. The overloaded zone, initially located at the lower part of cortical plate, proliferated upward in a positive feedback mode, unaffected by stress redistribution, until the whole thickness was engaged. Conclusions: Stresses induced around a microimplant by root contact may lead to a irreversible loss of microimplant stability.

• Development and Reproduction
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• v.5 no.2
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• pp.175-180
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• 2001

The ectopic expression of gonadotropin releasing hormone(GnRH and luteinizing hormone(LH) in several tissues is a quite intriguing phenomenon. Recently, the presence of GnRH and its receptor has been clearly demonstrated in rodents and human mammary gland. In this context, one can postulate that the presence of local circuit composed of GnRH and LH in the gland. The present study was undertaken to elucidate whether there is a correlation between the LH expression in rat mammary gland and physiological status during the process of mammary differentiation. LH contents in mammary gland from cycling to weaning rats were measured by radioimmunoassay(RIA). In cycling rats, changes of the LH level in both serum and mammary gland showed similar pattern as the highest level in proestrus and the lowest level in diestrus II stage. While the serum LH levels were fluctuated from pregnant through involution stage, a sharp decline of mammary LH contents was observed in the lactating rats. This decrement was recovered in involuting rats to the level of proestrus stage. Reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analyses demonstrated that the transcriptional activities of the mammary LH and GnRH were increased from diestrus I stage to estrus stage, and the increased levels were maintained in pregnant, lactation and involution stages. To test the hypothesis that the alteration in mammary LH expression might be steroid-dependant, ovariectomy(OVX) and steroid supplement model was employed. As expected, supplement of estradiol(E$_2$) after OVX remarkably decreased serum LH level compared to that in serum from vehicle-only treated rats. Likewise, administration of E$_2$ significantly reduced the mammary LH content. The present study demonstrated that (i) the LH expression in mammary gland could be altered by some physiological parameters such as estrous cycle, pregnancy, lactation and involution, and (ii) ovarian steroid especially estrogen seems to be one of major endocrine factors which are responsible for regulation of mammary LH expression.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.338-348
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• 2003

In the past decade, considerable progress has been made in developing the appropriate biotechnology for microalgal mass cultivation aimed at establishing a new agro-industry. This review points out the main biological constraints affecting algal biotechnology outdoors and the requirements for making this biotechnology economically viable. One of them is the availability of a wide variety of algal species and improved strains that favorably respond to varying environmental conditions existing outdoors. It is thus just a matter of time and effort before a new methodology like genetic engineering can and will be applied in this field as well. The study of stress physiology and adaptation of microalgae has also an important application in further development of the biotechnology for mass culturing of microalgae. In outdoor cultures, cells are exposed to severe changes in light and temperature much faster than the time scale re-quired for the cells to acclimate. A better understanding of those parameters and the ability to rapidly monitor those conditions will provide the growers with a better knowledge on how to optimize growth and productivity. Induction of accumulation of high value products is associated with stress conditions. Understanding the physiological response may help in providing a better production system for the desired product and, at a later stage, give an insight of the potential for genetic modification of desired strains. The potential use of microalgae as part of a biological system for bioremediation/detoxification and wastewater treatment is also associated with growing the cells under stress conditions. Important developments in monitoring and feedback control of the culture behavior through application of on-line chlorophyll fluorescence technique are in progress. Understanding the process associated with those unique environmental conditions may help in choosing the right culture conditions as well as selecting strains in order to improve the efficiency of the biological process.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.377-391
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• 1989

Recently it was suggested that the endogenous adenosine might be the mediator for the intercellular communication in the regulation of tubuloglomerular feedback control and renin release. Even though the previous data showed more important regulatory roles in the renal hemodynamics and renin release for the A1 adenosine receptor, it has not yet been settled down about the functional subclassification of renal adenosine receptors. The purpose of the present experiment was to clarify the importance of the renal adenosine receptors for the regulations of the hemodynamic, excretory and secretory functions. Experiments have been done in unanesthetized rabbits. Intrarenal arterial infusion of A1 adenosine antagonist, 8-phenyltheophylline, $3{\sim}30\;nmole/min$, increased urine flow, renal hemodynamics and urinary excretion of sodium. Intrarenal arterial infusion of Al antagonist, 1-3-diethyl-8-phenylxanthine (DPX), $10{\sim}100\;nmole/min$, increased renal hemodynamics and excretory functions. Non-specific adenosine antagonist, theophylline, $30{\sim}300\;nmole/min$, resulted in dose dependent increases in renal hemodynamics and excretory function. All of the three adenosine antagonists for the increases in renal hemodynamics, excretory and secretory functions was 8-phenyltheophylline > DPX > theophylline. These results suggest that the endogenous adenosine is important for the intrinsic regulatory roles for the renal functions through the adenosine receptors, and that the A1 adenosine receptor is more important than the A2 receptor in the regulation of renal hemodynamics, excretory and renin secretory functions.