• Development and Reproduction
• /
• v.21 no.4
• /
• pp.379-389
• /
• 2017

Connexin (Cx) involves in the regulation of various physiological functions of tissue by forming a channel, a gap junction which allows direct cell-cell communication, between adjacent cells. The effect of a single subcutaneous treatment of estradiol benzoate (EB) or flutamide (Flu) at the weaning age on the expression of Cx isoforms in the adult caput epididymis was evaluated in this research. Using quantitative real-time PCR analysis, a low-dose of EB [$0.015{\mu}g/kg$ body weight (BW)] caused significant decreases of Cx30.3, Cx32, Cx40, Cx43, and Cx45 mRNA levels and no change of Cx26, Cx31, Cx31.1, Cx37 transcript levels. The treatment of a high-dose EB ($1.5{\mu}g/kg\;BW$) resulted in reduced expression of Cx30.3, Cx31, Cx43, and Cx45 but increased expression of Cx37 and Cx40. Expression of all Cx isoforms examined, except Cx31, was significantly increased by the treatment of a low-dose Flu ($500{\mu}g/kg\;BW$). However, the treatment of a high-dose Flu (5 mg/kg BW) led significant expressional suppression of Cx30.3, Cx31, Cx31.1, Cx32, Cx40, Cx43, and Cx45 but an increase of Cx37 transcript level. With the comparison of previous findings, the expression of Cx isoforms in the adult epididymis after the exposure to EB or Flu is likely differentially regulated in regional-specific and/or exposed postnatal age-specific manner.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.1
• /
• pp.17-24
• /
• 2004

As the environmental pollution becomes serious global problem, the regulation of emission exhausted from automobiles is strengthened. Therefore, it is very important to know how to reduce the NOx and PM simultaneously in diesel engines, which has lot of merits such as high thermal efficiency, low fuel consumption and durability. By this reason, the new concept called as Homogeneous Charge Compression Ignition(HCCI) engines are spotlighted because this concept reduced NOx and P.M. simultaneously. However, it is well known that HCCI engines increased HC and CO. Thus, the investigation of combustion characteristics which consists cool and hot flames for HCCI engines were needed to obtain the optimal combustion condition. In this study, combustion characteristics for direct injection type HCCI engine such as quantity of cool flame and hot flame, ignition timing and ignition delay were investigated to clarify the effects of these parameters on performance. The results revealed that diesel combustion showed the two-stage ignition of cool flame and hot flame, the rate of cool flame increase and hot flame decrease with increasing intake air temperature. On the other hand, the gasoline combustion is the single-stage ignition and ignition timing is near the TDC. In addition mixed fuel combustion showed different phenomenon, which depends on the ratio of gasoline component. Ignition timing of mixed fuel is retarded near the TDC and the ignition delay is increased according to ratio of gasoline.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.32-38
• /
• 2006

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogenous charge compression ignition(HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. In addition, this study confirmed the possibility of securing optimum fuel economy emission reduction in the IMEP 8bar range(which could not be achieved with existing partially premixed combustion) through forced charging, exhaust gas recirculation(EGR), compression ratio change and application of DOC catalyst.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.1
• /
• pp.162-170
• /
• 2007

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. Anew concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogeneous charge compression ignition (HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. And it is investigated that the effects of the engine rpm and load(or A/F) to emission characteristics.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.31 no.3
• /
• pp.1-16
• /
• 2003

The ultimate goal of this research is to establish the movement rights of people with physical disabilities. To achieve this goal, the authors have investigated the regulation and restrictions of physical facilities to guarantee the movement rights and investigated how well these facilities were constructed. The authors then have analyzed and compared the results. The purposes of this research are as follows. First, the authors investigated and analyzed the present conditions of selected public facilities to propose improvement measures for the disabled, pregnant and seniors so that they could actively participate in cultural activities as normal people do. Second, the designs resulting from this research are provided so as to be helpful to disabled people in everyday life, which is different from previously conducted research. Third, the authors have selected facilities with outdoor areas to differentiate the results from those reported recently through research conducted on indoor buildings. The final step of this research is to provide basic design data on outdoor areas to establish true movement rights for the disabled. According to these research findings, the shortest moving distance cannot be guaranteed only by establishing facilities that follow the Article 3 law about guarantee of convenience improvement for the disabled. If the movement path is not regulated, the facility standards may not exist in one part and the part itself may become obscured and the distance could become longer than necessary. Accordingly, for real movement rights the movement path should be guaranteed not to be violated by other obstacles. The results of this study offer convenience when moving within the outdoor space of cultural facilities by providing direct information for the disabled. The value of this study is that it is the first study on movement rights and movement paths for people with physical disabilities.

• Korean Journal of Pharmacognosy
• /
• v.45 no.3
• /
• pp.262-267
• /
• 2014

Royal jelly composes of many components, especially protein. Protein is a major factor which cause allergy. We focused on water soluble royal jelly (WSRJ) that was removed allergy - inducing protein. 10-hyroxy-2-decenoic acid content of WSRJ is 2.42 g/100 g, which is double compared to that of lypophilized RJ. To further access WSRJ as a cosmetic ingredient and potential external treatment for topical use, we investigated its ability to inhibit tyrosinase activity and melanin biosynthesis on melanogenesis in B16F1 melanoma cells. We found that WSRJ increased the cell viability in B16F1 melanoma cell and WSRJ (1~10 mg/ml) inhibited melanin synthesis in with 10 nM ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) for 48 h. WSRJ inhibited direct tyrosinase activity, which decreased melanin synthesis in ${\alpha}$-MSH stimulated B16F1 melanoma cells. Thease findings suggest that WSRJ induces the down regulation of melanogenesis by inhibiting tyrosinase activation.

• Journal of Microbiology
• /
• v.43 no.4
• /
• pp.375-380
• /
• 2005

Autonomous ultradian metabolic oscillation (T$\simeq$50 min) was detected in an aerobic chemostat culture of Saccharomyces cerevisiae. A pulse injection of GSH (a reduced form of glutathione) into the culture induced a perturbation in metabolic oscillation, with respiratory inhibition caused by $H_2S$ burst pro-duction. As the production of $H_2S$ in the culture was controlled by different amino acids, we attempted to characterize the effects of GSH on amino acid metabolism, particularly with regard to branched chain and sulfur-containing amino acids. During stable metabolic oscillation, concentrations of intra-cellular glutamate, aspartate, threonine, valine, leucine, isoleucine, and cysteine were observed to oscil-late with the same periods of dissolved $O_2$ oscillation, although the oscillation amplitudes and maximal phases were shown to differ. The methionine concentration was stably maintained at 0.05 mM. When GSH (100 $\mu$M) was injected into the culture, cellular levels of branched chain amino acids increased dramatically with continuous $H_2S$production, whereas the cysteine and methionine concentrations were noticeably reduced. These results indicate that GSH-dependent perturbation occurs as the result of the promotion of branched chain amino acid synthesis and an attenuation of cysteine and methionine synthesis, both of which activate the generation of $H_2S$. In a low sulfate medium containing 2.5 mM sulfate, the GSH injections did not result in perturbations of dissolved $O_2$ NAD(P)H redox oscillations without burst $H_2S$ production. This suggests that GSH-dependent perturbation is intimately linked with the metabolism of branched-chain amino acids and $H_2S$ generation, rather than with direct GSH-GSSG redox control.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.4
• /
• pp.559-569
• /
• 2021

As one of the major types of lung cancer, non-small cell lung cancer (NSCLC) accounts for the majority of cancer-related deaths worldwide. Treatments for NSCLC includes surgery, chemotherapy, and targeted therapy. Among the targeted therapies, resistance to inhibitors of the epidermal growth factor receptor (EGFR) is common and remains a problem to be solved. MET (hepatocyte growth factor receptor) amplification is one of the major causes of EGFR-tyrosine kinase inhibitor (TKI) resistance. Therefore, there exists a need to find new and more efficacious therapies. Deoxypodophyllotoxin (DPT) extracted from Anthriscus sylvestris roots exhibits various pharmacological activities including anti-inflammation and anti-cancer effects. In this study we sought to determine the anti-cancer effects of DPT on HCC827GR cells, which are resistant to gefitinib (EGFR-TKI) due to regulation of EGFR and MET and their related signaling pathways. To identify the direct binding of DPT to EGFR and MET, we performed pull-down, ATP-binding, and kinase assays. DPT exhibited competitive binding with ATP against the network kinases EGFR and MET and reduced their activities. Also, DPT suppressed the expression of p-EGFR and p-MET as well as their downstreat proteins p-ErbB3, p-AKT, and p-ERK. The treatment of HCC827GR cells with DPT induced high ROS generation that led to endoplasmic-reticulum stress. Accordingly, loss of mitochondrial membrane potential and apoptosis by multi-caspase activation were observed. In conclusion, these results demonstrate the apoptotic effects of DPT on HCC827GR cells and signify the potential of DPT to serve as an adjuvant anti-cancer drug by simultaneously inhibiting EGFR and MET.

• Nutrition Research and Practice
• /
• v.13 no.5
• /
• pp.415-424
• /
• 2019

BACKGROUND/OBJECTIVES: Existing evidence on lifestyle modification programs for weight loss is limited by the high attrition rate of such programs. Identifying predictors of adherence to a lifestyle modification program could result in program improvement. However, little is known about behavior-specific adherence and its psychological predictors. This study aimed to examine the psychological predictors of adherence after one-month participation in a community-based lifestyle modification program among Chinese overweight and obese adults in Hong Kong. SUBJECTS/METHODS: A total of 205 Chinese overweight and obese adults aged $38.9{\pm}10.5years$ completed the study. Data were collected at baseline and after one month using self-reported questionnaires, which assessed knowledge (self-developed scale), motivation (Treatment Self-Regulation Questionnaire), stage of change (Stage of Exercise Scale) and self-efficacy (Self-Rated Abilities for Health Practices Scale). At one month, a 4-day dietary recall and the International Physical Activity Questionnaire-Short Form were used to assess dietary and physical activity (PA) adherence. Food and PA diaries were examined to indicate self-monitoring. Program attendance was tracked between baseline and one-month follow-up. RESULTS: After one month, participants reported high dietary adherence, attendance, and adherence to self-monitoring but low PA adherence. Multiple regression analyses suggested that diet self-efficacy (baseline) and nutrition knowledge (one-month change) were independent predictors of dietary adherence score at one month, whereas autonomous PA motivation (baseline) and PA self-efficacy (both baseline and one-month change) were independent predictors of PA adherence score at one month. No significant psychological predictor was identified for attendance or self-monitoring. CONCLUSIONS: The results suggest that the effect of psychological factors on adherence differs between diet and PA adherence outcomes. To promote adherence, practitioners should assess self-efficacy, knowledge, and motivation at the beginning of a weight-loss program and explore behavior-specific strategies to improve knowledge and self-efficacy. The results of this study have direct implications for program improvements.

• Environmental and Resource Economics Review
• /
• v.27 no.4
• /
• pp.725-743
• /
• 2018

Industrial groups (representing the polluters) and environmental non-governmental organizations (representing the victims) respond differently to various environmental policy instruments. As the affected group's power is large either politically or economically, it is unlikely that a single instrument will be actually selected despite being effective or efficient because of the high political costs associated with it. In this paper, we focus on the political role that energy subsidies play in creating a compromise between energy consuming polluters and victims of pollution. The use of a Dolbear (1967)'s triangle Edgeworth box model makes it possible to examine how policy selection affects the income distribution and welfare levels of two groups. The effects of a single policy instrument of either direct regulation or tax are compared with those of a policy mix that includes energy subsidies. We found that the addition of energy subsidies would increase the chance of compromise between polluters and victims.