• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 하계종합학술대회논문집
• /
• pp.74-77
• /
• 1998

We consider connection-oriented wireless cellular networks. These networks employ dedicated radio channels for the transmission of signaling information. A forward signaling channel is a common signaling channel assigned to carry the multiplexed stream of paging and channel allocation(virtual circuit allocation) packets from a base station to mobile stations. The delay levels experienced by paging and channel allocation packets have serious effect on the utilization level of the limited radio channel capacity. While a slotted mode operation is used to reduce the power consumption level at mobile stations, it may induce an increase in packet delay levels. In this paper, we thus consider a multiplexing scheme for paging and channel allocation packets under which slots are dynamically allocated for the paging packet transmission. For this dynamic scheme, we develop an analytical method for deriving the delay characteristics exhibited by paging and channel allocation packets, and investigate the effect of network parameters on the delay level by using this method.

• 한국동물위생학회지
• /
• 제20권1호
• /
• pp.37-45
• /
• 1997

The result of API staph-ident system was compared with cellular fatty acid composition for the identification of Staphylococcus species isolated from cattle. Isolated strains from cattle were correctly identified to S aureus, S intermedius, S hyicus, S simulans, S saprophyticus, S epidemis, S sciuri and S xylosus by API staph-ident system. The correlation between bacterial cellular fatty acid profile and Staphylococcus species isolated to API STAPH-IDENT system were. In conclusion, the result presented indicate that Staphylococci can be indentified to the species level by the cellular fatty acid profiles. Moreover, computerized fatty acid profile correlative anaylsis can be applied for determining identify of Staphylococcus species.

• 산업공학
• /
• 제16권spc호
• /
• pp.87-92
• /
• 2003

Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size.

• Mass Spectrometry Letters
• /
• 제14권4호
• /
• pp.121-140
• /
• 2023

It is becoming more and more clear that each cell, even those of the same type, has a unique identity. This sophistication and the diversity of cell types in tissue are what are pushing the necessity for spatially distributed omics at the single-cell (SC) level. Single-cell chemical assessment, which also provides considerable insight into biological, clinical, pharmacodynamic, pathological, and toxicity studies, is crucial to the investigation of cellular omics (genomics, metabolomics, etc.). Mass spectrometry (MS) as a tool to image and profile single cells and subcellular organelles facilitates novel technical expertise for biochemical and biomedical research, such as assessing the intracellular distribution of drugs and the biochemical diversity of cellular populations. It has been illustrated that ambient mass spectrometry (AMS) is a valuable tool for the rapid, straightforward, and simple analysis of cellular and sub-cellular constituents and metabolites in their native state. This short review examines the advances in ambient mass spectrometry (AMS) and ambient mass spectrometry imaging (AMSI) on single-cell analysis that have been authored in recent years. The discussion also touches on typical single-cell AMS assessments and implementations.

• Molecules and Cells
• /
• 제28권5호
• /
• pp.489-494
• /
• 2009

We have previously shown that the down-regulation of protein kinase CKII activity is tightly associated with cellular senescence of human fibroblast IMR-90 cells. Here, we examined the roles of p53 and $p21^{Cip1/WAF1}$ in senescence development induced by CKII inhibition using wild-type, isogenic p53-/- and isogenic p21-/- HCT116 human colon cancer cell lines. A senescent marker appeared after staining for senescence-associated ${\beta}$-galactosidase activity in wild-type HCT116 cells treated with CKII inhibitor or $CKII{\alpha}$ siRNA, but this response was almost abolished in p53- or $p21^{Cip1/WAF1}$-null cells. Increased cellular levels of p53 and $p21^{Cip1/WAF1}$ protein occurred with the inhibition of CKII. CKII inhibition upregulated p53 and $p21^{Cip1/WAF1}$ expression at post-transcriptional level and transcription level, respectively. RB phosphorylation significantly decreased in cells treated with CKII inhibitor. Taken together, this study shows that the activation of the $p53-p21^{Cip1/WAF1}$ pathway acts as a major mediator of cellular senescence induced by CKII inhibition.

• 한국식품과학회지
• /
• 제32권6호
• /
• pp.1389-1395
• /
• 2000

자궁 경부암은 매년 약 50만명 정도씩 사망하는 여성의 치명적인 사망원인의 하나이다. 인두유종 바이러스(HPV) 16형 및 18형과 자궁 경부암과의 긴밀한 관련성은 잘 알려져 있다. 옻 추출물 Rhus가 HPV 16형의 E6, E7 발암 유전자를 억제하는지 여부를 측정하였다. 이 Rhus는 자궁 경부암 세포주(C-33A, SiHa, Caski)와 HaCaT keratinocytes의 분열은 농도 의존적으로 억제하였다. In vitro binding assay와 효소면역측정법에 의하면 Rhus가 암 억제인자인 p53과 결합하여 분해 시키는데 필수적인 E6와 E6AP와의 결합을 억제할 뿐더러 암 억제인자 Rb와 E7과의 결합을 억제하였다. RT-PCR에 의하면 Rhus에 의해 E6 mRNA의 level이 감소하였으나 E7 mRNA는 변하지 않았음을 보여주었다. 이들 결과에 의하면 Rhus가 HPV 16형의 E6와 E7의 발암성을 억제함을 보여 주므로 HPV에 의해 유도된 자궁 경부암의 치료에 유효할 것으로 사료되어 좀 더 자세한 in vitro실험 등이 요구된다.

• Journal of Veterinary Science
• /
• 제23권2호
• /
• pp.40.1-40.13
• /
• 2022

Background: Somatic cell nuclear transfer (SCNT) is used widely in cloning, stem cell research, and regenerative medicine. The type of donor cells is a key factor affecting the SCNT efficiency. Objectives: This study examined whether urine-derived somatic cells could be used as donors for SCNT in pigs. Methods: The viability of cells isolated from urine was assessed using trypan blue and propidium iodide staining. The H3K9me3/H3K27me3 level of the cells was analyzed by immunofluorescence. The in vitro developmental ability of SCNT embryos was evaluated by the blastocyst rate and the expression levels of the core pluripotency factor. Blastocyst cell apoptosis was examined using a terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. The in vivo developmental ability of SCNT embryos was evaluated after embryo transfer. Results: Most sow urine-derived cells were viable and could be cultured and propagated easily. On the other hand, most of the somatic cells isolated from the boar urine exhibited poor cellular activity. The in vitro development efficiency between the embryos produced by SCNT using porcine embryonic fibroblasts (PEFs) and urine-derived cells were similar. Moreover, The H3K9me3 in SCNT embryos produced from sow urine-derived cells and PEFs at the four-cell stage showed similar intensity. The levels of Oct4, Nanog, and Sox2 expression in blastocysts were similar in the two groups. Furthermore, there is a similar apoptotic level of cloned embryos produced by the two types of cells. Finally, the full-term development ability of the cloned embryos was evaluated, and the cloned fetuses from the urine-derived cells showed absorption. Conclusions: Sow urine-derived cells could be used to produce SCNT embryos.

• Journal of Microbiology and Biotechnology
• /
• 제15권5호
• /
• pp.1130-1134
• /
• 2005

To monitor the possibility of horizontal gene transfer between transgenic potato and bacteria in the environment, the gene flow from glufosinate-tolerant potato to bacteria in soils was investigated. The soil samples treated with the leaf tissue of either glufosinate-tolerant or glufosinate-sensitive potato were subjected to PCR and Southern hybridization to determine possible occurrence of glufosinate-resistant soil bacteria and to detect the bar (phosphinothricin acetyltransferase) gene, conferring tolerance to glufosinate. The bar gene was not detected from genomic DNAs extracted at different time intervals from the soil samples, which had been treated with the leaf tissue of either transgenic or non-transgenic potato for 2 to 8 weeks. In addition, the level of glufosinate-resistant bacteria isolated from the soil samples treated with the leaf tissue of transgenic potato was similar to that of the samples treated with non-transgenic potato after 4 months of incubation at $25^{\circ}C$. The bar gene was not detected in the genomic DNAs extracted from colonies growing on the plate containing glufosinate, indicating that the bacteria could acquire the resistant phenotype to glufosinate by another mechanism without the uptake of the bar gene from glufosinate-tolerant potato.

• Journal of Microbiology and Biotechnology
• /
• 제19권9호
• /
• pp.904-910
• /
• 2009

The development of effective cellular imaging requires a specific labeling method for targeting, tracking, and monitoring cellular/molecular events in the living organism. For this purpose, we studied the cellular uptake of isocyanide-functionalized silver and gold nanoparticles by surface-enhanced Raman scattering (SERS). Inside a single mammalian cell, we could monitor the intracellular behavior of such nanoparticles by measuring the SERS spectra. The NC stretching band appeared clearly at ${\sim}2,100cm^{-1}$ in the well-isolated spectral region from many organic constituents between 300 and 1,700 or 2,800 and $3,600cm^{-1}$. The SERS marker band at ${\sim}2,100cm^{-1}$ could be used to judge the location of the isocyanide-functionalized nanoparticles inside the cell without much spectral interference from other cellular constituents. Our results demonstrate that isocyanide-modified silver or gold nanoparticle-based SERS may have high potential for monitoring and imaging the biological processes at the single cell level.

• 지역사회간호학회지
• /
• 제17권4호
• /
• pp.552-562
• /
• 2006

Purpose: This study was conducted to describe the state of middle school students' addicted use of a cellular phone and their psychosocial characteristics and to examine differences in psychosocial factors as impulsivity, stress, anxiety and classroom attitudes according to the level of addiction. Method: As the subjects of this study, 747 middle school students who use a cellular phone in B Metropolitan City were selected through stratified random sampling, and they were asked to answer a self-administered study questionnaire. Data were analyzed using frequency, descriptive statistics, $x^2-test$, t-test, and one-way ANOVA. Results Among the respondents, 15.7% fell into the addicted user group while 56.0% fell into the dependent user group and 28.3% turned out to be non-addicted users. The levels of impulsivity, stress and anxiety were higher in the addicted user group than in the dependent user group and the non-addicted user group. The addicted user group also showed a very bad learning attitude. Conclusion: Addiction to the use of a cellular phone, which may have negative influences on the users' psychosocial characteristics, needs to be detected earlier, and preventive education should be offered in order to prevent such addiction.