• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1278-1282
• /
• 2005

Air mattress is now used widely to prevent the pressure ulcer by reducing the localized pressure peaks. In this paper an air-cell mattress and its pressure control method based on an approximate anthropometric model are presented. The air-cell mattress has eighteen cylindrical air cells made of porous material allowing air leakage to contribute in reducing the development of pressure ulcer by lowering the pressure peak, temperature and humidity. To determine an optimal air-cell pressure appropriate for each user, we divide the parts of the body into four sections such as head, trunk, hip, and leg. Then, the pressure of each section is independently calculated from the weight of each part based on the individual body height and weight and the approximate anthropometric model. Air supply system for the air-cell mattress is implemented by using four electronic solenoid valves and an air compressor, and it is driven by a real-time micro-controller. The experimental results with seven subjects shows that the proposed air-cell mattress is effective for the prevention of the pressure ulcer.

• Journal of Communications and Networks
• /
• v.15 no.5
• /
• pp.469-475
• /
• 2013

In this paper, we propose an efficient interference management technique which controls the number of resource blocks (or subcarriers) shared with other cells based on statistical interference levels among cells. The proposed technique tries to maximize average throughput of a femto cell user under a constraint on non-real time control of a femto cell network while guaranteeing a target throughput value of a macro cell user. In our proposed scheme, femto cells opportunistically use resource blocks allocated to other cells if the required average user throughput is not attained with the primarily allocated resource blocks. The proposed method is similar to the underlay approach in cognitive radio systems, but resource block sharing among cells is statistically controlled. For the statistical control, a femto cell sever constructs a table storing average mutual interference among cells and periodically updates the table. This statistical approach fully satisfies the constraint of non-real time control for femto cell networks. Our simulation results show that the proposed scheme achieves higher average femto user throughput than conventional frequency reuse schemes for time varying number of users.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.6A
• /
• pp.371-378
• /
• 2003

In Code Division Multiple Access (CDMA) system, the cell capacity is defined as the number of available channels in a cell, which is limited by the interferences. When a new call is accepted at its home cell, this adds the interference to the home and its neighboring cells. This paper proposes a call admission control based on mobile transmission power prediction. The home cell has enough capacity to admit new call and if home cell would have admitted a new call, it calculates the mobile transmission power. Also, its neighboring cell can predict the amount of interference using the predicted mobile transmission power. Thus, the new mobile is accepted by its home cell if QoS(Quality Of Service) is guaranteed in its neighboring cells. The simulation result shows that the proposed scheme largely reduces the outage probability in the neighboring cells.

• The Journal of Pediatrics of Korean Medicine
• /
• v.22 no.1
• /
• pp.123-147
• /
• 2008

Objectives This study is to investigate how dose Ikhwang-San can be effective on SD rats which deteriorated immunity caused by methotrexate. Methods The test sample were dosed once a day for 14 days by gastric gavage at the beginning of dosage 1000, 500 and 250㎎/㎏/10㎖ from 2 days after last MTX-dosing, and the changes of the body and spleen weight, total number of blood leukocytes, total number of lymphocytes, the percentage of B-cell, T-cell, CD3+CD4+ T-cell, CD3+CD8+ T-cell and CD4+/CD8+ T-cell ratios in the blood and spleen were observed. Results The changes of the body and spleen weight, the total number of blood leukocytes, the total number of lymphocyte in the blood and spleen were significantly increased in IHS Extracts groups comparing with the control group. The percentage of B-cell, T-cell, CD3+CD4+ T-cell in the blood and spleen were significantly increase in IHS groups and comparing with the control group. The ratio of CD4+/CD8+ T-cell in blood and spleen was significantly increased in IHS Extracts groups comparing with the control group. Conclusions According to those results, Ikhwang-San has good immunostimulating effect on SD rats which had deteriorated immunity caused by methotrexate.

• KSBB Journal
• /
• v.31 no.1
• /
• pp.66-72
• /
• 2016

Chinese hamster ovary (CHO) cells have been widely used for production of various recombinant proteins such as cytokines and monoclonal antibodies. The cell aggregation and cell death in CHO cell culture directly affect cell viability, and productivity and quality of products. In this study, we investigated preventing effects of storage-protein 2 (SP2) derived from silkworm hemolymph on cell aggregation and cell death in CHO cell culture producing albuminerythropoietin (Alb-EPO). The viable cell density in the culture supplemented with 2 mg/mL SP2 was 1.71-fold higher than that in control culture. Increased titer of Alb-EPO was also found in the culture with SP2. Morphology of CHO cells in SP2 supplemented cultures did not differ from that of control. In addition, the cell aggregation rate of the SP2 cultures was reduced 20% compared to the control. Finally, we confirmed that the apoptosis was strongly suppressed by addition of SP2 in the cultures. These results clearly demonstrate that SP2 can be served as an effective supplement for enhancing titer of Alb-EPO via reducing cell aggregation and cell death.

• Molecules and Cells
• /
• v.37 no.7
• /
• pp.547-553
• /
• 2014

Glioblastoma multiforme (GBM) is one of the most common brain malignancies and has a very poor prognosis. Recent evidence suggests that the presence of cancer stem cells (CSC) in GBM and the rare CSC subpopulation that is resistant to chemotherapy may be responsible for the treatment failure and unfavorable prognosis of GBM. A garlic-derived compound, Z-ajoene, has shown a range of biological activities, including anti-proliferative effects on several cancers. Here, we demonstrated for the first time that Z-ajoene specifically inhibits the growth of the GBM CSC population. CSC sphere-forming inhibition was achieved at a concentration that did not exhibit a cytotoxic effect in regular cell culture conditions. The specificity of this inhibitory effect on the CSC population was confirmed by detecting CSC cell surface marker CD133 expression and biochemical marker ALDH activity. In addition, stem cell-related mRNA profiling and real-time PCR revealed the differential expression of CSC-specific genes, including Notch, Wnt, and Hedgehog, upon treatment with Z-ajoene. A proteomic approach, i.e., reverse-phase protein array (RPPA) and Western blot analysis, showed decreased SMAD4, p-AKT, 14.3.3 and FOXO3A expression. The protein interaction map (http://string-db.org/) of the identified molecules suggested that the AKT, ERK/p38 and $TGF{\beta}$ signaling pathways are key mediators of Z-ajoene's action, which affects the transcriptional network that includes FOXO3A. These biological and bioinformatic analyses collectively demonstrate that Z-ajoene is a potential candidate for the treatment of GBM by specifically targeting GBM CSCs. We also show how this systemic approach strengthens the identification of new therapeutic agents that target CSCs.

• Clinical and Experimental Reproductive Medicine
• /
• v.25 no.1
• /
• pp.77-86
• /
• 1998

The uptake of glucose for metabolism and growth is essential to most animal cells and is mediated by glucose-transporter (GLUT) proteins. The aim of this study was to determine which class of glucose transporter molecules was responsible for uptake of glucose in the mouse early embryo and at which stage the corresponding genes were expressed. In addition, co-culture system with vero cell was used to investigate the effect of the system on GLUT expression. Two-cell stage embryos were collected from the superovulated ICR female and divided into 3 groups. As a control, embryos were cultured in 0.4% BSA-T6 medium which includes glucose. For the experimental groups, embryos were cultured in either co-culture system with vero cells or glucose-free T6 medium supplemented with 0.4% BSA and pyruvate as an energy substrate. 2-cell to blastocyst stage embryos in those groups were respectively collected into microtubes (50 embryos/tube). Total RNA was extracted and RT-PCR was performed. The products were analysed after staining ethidium bromide by 2% agarose gel electrophoresis. Blastocysts were collected from each group at l20hr after hCG injection. They were fixed in 2.5% glutaraldehyde, stained with hoechst, and mounted for observation. In control, GLUT1 was expressed from 4-cell to blastocyst. GLUT2 and GLUT3 were expressed in morula and blastocyst. GLUT4 was expressed in all stages. When embryos were cultured in glucose-free medium, no significant difference was shown in the expression of GLUT1, 2 and 3, compared to control. However GLUT4 was not expressed until morular stage. When embryos were co-cultured with vero cell, there was no significant difference in the expression of GLUT1, 2, 3 and 4 compared to control. To determine cell growth of embryos, the average cell number of blastocyst was counted. The cell number of co-culture ($93.8{\pm}3.1$, n=35) is significantly higher than that of control and glucose-free group ($76.6{\pm}3.8$, n=35 and $68.2{\pm}4.3$, n=30). This study shows that the GLUT genes are expressed differently according to embryo stage. GLUTs were detectable throughout mouse preimplantation development in control and co-culture groups. However, GLUT4 was not detected from 2- to 8-cell stage but detected from morula stage in glucose-free medium, suggested that GLUT genes are expressed autocrinally in the embryo regardless of the presence of glucose as an energy substrate. In addition, co-culture system can increase the cell count of blastocyst but not improve the expression of GLUT. In conclusion, expression of GLUT is dependent on embryo stage in preimplantation embryo development.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.10
• /
• pp.1122-1126
• /
• 2009

The exogenously added cadaverine is effective in protecting Vibrio vulnificus from methyl viologen (MV)-induced superoxide stress at pH 8.5. Such a protective effect by cadaverine was not observed at pH 7.5. Consistently, the accumulated level of intracellular cadaverine at pH 8.5 is approximately four times as much as that of the control cell at pH 7.5. Cadaverine accumulation is not affected by MV. The protection of V. vulnificus by cadaverine from superoxide stress was abolished when cadB coding for the lysine-cadaverine antiporter was interrupted. However, the cadaverine-mediated protection was complemented with cadB DNA. Therefore, CadB of V. vulnificus not only acts as a lysine-cadaverine antiporter at acid pH to neutralize the external medium, but also mediates cadaverine uptake at alkaline pH to result in cell protection from superoxide stress.

• Applied Biological Chemistry
• /
• v.51 no.4
• /
• pp.294-298
• /
• 2008

Effects of endosulfan (EN), an insecticide, and bleomycin (BL), an antibiotic, on the body weight in the normal mice, and the in vivo cell growth, tumor weight, and hematological parameters of the Ehrlich ascites carcinoma (EAC) cell-bearing Swiss albino mice Mus musculus were evaluated. EN and BL were respectively administered orally and intraperitoneally to the experimental mice; the control group consisted of EAC cell-bearing untreated mice only. EN reduced the body weight in normal mice, whereas BL resulted in a steady body weight compared to the control. EN increased the EAC cell count significantly by reducing the growth of normal viable cells. In contrast, BL reduced the cell count by increasing the proportion of viable cells in the body. The tumor weights induced by EN were significantly higher than those of the EAC control and the BL-treated animals. In comparisons with the control and the BL mice, hematological parameters such as hemoglobin (%) and the number of RBC and lymphocytes were lowered, while counts of WBC, neutrophils, and monocytes were elevated after EN treatments. These results show that BL is capable of reducing the EN-induced neoplastic and haematological alterations in the mice under laboratory conditions.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.11 no.7
• /
• pp.591-597
• /
• 2001

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.