• Bulletin of the Korean Chemical Society
• /
• 제32권2호
• /
• pp.625-629
• /
• 2011

A quantitative analysis of the decreasing rate of the monomer and increasing rate of the polymerization was made by monitoring radiation level increments using Raman spectroscopy within the therapeutic radiation range for a normoxic polymethacrylic acid gel dosimeter. The gel dosimeter was synthesized by stirring materials such as gelatin, distilled water, methacrylic acid, hydroquinone and tetrakis phosphonium chloride at $50^{\circ}C$, and the synthesized gel was contained in a 10- mm diameter and 32-mm high vial to conduct measurement. 24 hours after gel synthesis, it was irradiated from 0 Gy to 20 Gy by 2 Gy using a Co-60 radiotherapy unit. With use of the Cryo FE-SEM, structural changes in the 0 Gy and 10 Gy gel dosimeters were investigated. The Raman spectra were acquired using 532-nm laser as the excitation source. In accordance with fitting the changes in C-COOH stretching (801 $cm^{-1}$), C=C stretching (1639 $cm^{-1}$) and vinyl $CH_2$ stretching (3114 $cm^{-1}$) vibrational modes for monomer and $CH_2$ bending vibrational mode (1451 $cm^{-1}$) for polymer, sensitive parameter S for each mode was calculated. The values of S for monomer bands and polymer band were ranged in $6.0{\pm}2.6$ Gy and $7.2{\pm}2.3$ Gy, respectively, which shows a relatively good conformity of the decreasing rate of monomer and the increasing rate of polymerization within the range of error.

• 대한전자공학회논문지TC
• /
• 제49권1호
• /
• pp.85-91
• /
• 2012

본 논문은 Ka 대역 밀리미터파 탐색기용 주파수합성기 제작에 대한 논문이다. 높은 주파수 해상도와 빠른 천이 응답 시간을 위해 DDS(Direct Digital Synthesizer)를 이용한 디지털 합성방식으로 설계하였다. 하지만 DDS의 주파수합성 대역은 시스템 클럭의 1/2정도로 제한되기 때문에 주파수합성 범위가 저주파대역으로 제한되는 단점을 가지고 있다. 그래서 주파수 4체배기와 국부신호를 사용하여 Ka 대역으로 상향 변환하였다. 제안된 주파수합성기는 대역폭 500MHz, 주파수 스위칭 시간은 $0.7{\mu}s$이하, 불요파 특성 -52dBc이하, 위상잡음 특성은 오프셋 100kHz에서 -99dBc/Hz, 평탄도는 ${\pm}1dB$이하로 측정되었다.

• 대한한의학원전학회지
• /
• 제21권2호
• /
• pp.101-112
• /
• 2008

Generally, we regard the concept of Guchim(九鍼) in "Naegyeong(內經)" as the a generic term of acupuncture means of nine kinds of forms and usages. However, it also contains the meaning of methods and transcriptures of acupuncture. The diversity of Guchim reflects that it has a high level diagnosis and treatment based on overall analysis of symptoms and signs. And among the treatments, reinforcing and reducing methods are prominent. The treatments of reinforcing and reducing methods, usually use Hochim(毫鍼), the filiform needle. The focus of Guchim, in reinforcing and reducing of Gi(氣), is reinforcing and reducing by way of drainage of Gi. And it mainly deals with diseases of Gi. From the research of the philosophic background of the number Nine in Chinese philosophy, number nine symbolizes the posterior and space, as number one symbolizes apriority and time. In this circumstances, Guchim became the supreme method of acupuncture. The concept of Gwanchim(官鍼), standardized needle in "Naegyeong" also expresses the Guchim as theory and skill in standardized traditional medicine. The period of materialization of Guchim and Gwanchim lies in from the era of Jeonguk[戰國時代, the age of civil wars] to Han dyansty[漢代], when the "Naegyeong" made a synthesis of the medicine in those days, as the society unified politically and ideologically. In this process, Guchim was sublimated in method of acupuncture which contained absolute authority.

• Journal of Microbiology and Biotechnology
• /
• 제22권4호
• /
• pp.437-447
• /
• 2012

Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plant-growth-promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 ${\mu}M$ auxin per ${\mu}g$ of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.

• The Korean Journal of Physiology and Pharmacology
• /
• 제4권6호
• /
• pp.507-513
• /
• 2000

ErbB3/HER3 is a cell surface receptor which belongs to the ErbB/HER subfamily of receptor protein tyrosine kinases. When expressed in NIH/3T3 cells, ErbB3 can form heterodimeric coreceptor with endogenous ErbB2. Among known intracellular effectors of the ErbB2/ErbB3 are mitogen-activated protein kinase (MAPK) and phosphoinositide (PI) 3-kinase. In the present study, we studied relative contributions of above two distinct signaling pathways to the heregulin-induced mitogenic response via activated ErbB3. For this, clonal NIH-3T3 cell lines expressing wild-type ErbB3 and ErbB3 mutants were stimulated with $heregulin{\beta}_1$. While cyclin D1 level was markedly high and further increased by treatment of heregulin in cells expressing wild-type ErbB3, the elimination of either Shc binding or PI 3-kinase binding lowered both levels. This result was supported by the reduction of cyclin $D_1$ expression by preteatment with MAPK kinase inhibitor or PI 3-kinase inhibitor before stimulation with heregulin. In accordance with the cyclin $D_1$ expression, elimination of either Shc binding or PI 3-kinase binding reduced the heregulin-induced DNA synthesis and cell growth rate. Our results obtained by the comparison of wild-type and ErbB3 mutants indicate that the full induction of the cell cycle progression through $G_1/S$ phase by ErbB3 activation is dependent on both Shc/MAPK and PI 3-kinase signal transduction pathways.

• Natural Product Sciences
• /
• 제17권2호
• /
• pp.117-122
• /
• 2011

We investigated the effect of Orostachys japonicus extracts on serum lipids, leptin and insulin level in hyperlipidemic rats. Also, diacylglycerol acyltransferase (DGAT) activity and thiobarbituric acid reactive substance (TBARS) were assessed. Inhibitory effect of DGAT related to triglyceride synthesis emerged approximately 96% in EtOAc fraction and showed 90% and 67%, respectively, in CHCl3 and BuOH fractions. Furthermore, the EtOAc and BuOH fractions inhibited 81% and 77%, respectively, in glycerol-3-phosphate acyl transferase (GPAT). Hyperlipidemia and obesity marker, contents of leptin and insulin on serum of hyperlipidemic rats, decreased 50% and 25%, respectively, compared with control group in treated EtOAc fraction. The oxidative stress marker, a concentration of TBARS, showed decrease of approximately 30% in treated EtOAc fraction. Moreover, high density lipoprotein (HDL)-cholesterol contents on serum of rats fed a hyperlipidemic diet were increased 10% and low density lipoprotein (LDL)-cholesterol decreased 50% as well as triglyceride amount of feces multiplied approximately two times more than control group in treated EtOAc fraction. The data suggest that the fractions of O. japonicus may be a potent biomaterial for treatment of hyperlipidemia or obesity.

• 한국해양바이오학회지
• /
• 제1권4호
• /
• pp.275-281
• /
• 2006

3.4-dichloroaniline (DCA)를 함유한 최소배지에서의 집식배양과 배양 후 HPLC에 의한 잔류분석을 통해 3,4-DCA의 분해 능력이 우수한 균주 Arthrobacter sp. YM-14를 여천석유화학공단 인근의 갯벌에서 분리하였다. 분리균 YM-14는 1/10 LB 배지에 함유된 50 ppm의 3,4-DCA를 12 시간 만에 완전히 제거하였다. 이외에도 분리균 YM-14는 3-chloroaniline(CA), 2,5-DCA 및 3,5-DCA의 분해 활성을 나타내었으나 2-CA, 4-CA와 2,4-DCA에 대한 분해활성을 가지고 있지는 않았다. 또한, 분리균 YM-14에서 3,4-DCA의 유도에 의한 catechol 1,2-dioxygenase 활성의 증가가 관찰되었다. 이러한 결과는 catechol 1,2-dioxygenase이 3,4-DCA 분해에 관여하는 중요한 효소군중의 하나로 생각된다.

• 한국통신학회논문지
• /
• 제34권9B호
• /
• pp.939-946
• /
• 2009

본 논문에선 기계 기술 언어(machine descriptions language)인 LISA(Language for Instruction Set Architecture)를 통하여 시뮬레이션 모델로 설계한 새로운 네트워크 ASIP(Application Specific Instruction-set Processor)을 제안한다. 제안한 네트워크 ASIP은 라우터(router)에서 패킷 프로세싱을 담당하는 전용엔진을 목적으로 설계되었다. 이를 위해 MIPS(Microprocessor without Interlock Pipeline Stages) 아키텍처를 기반으로 한 일반적인 ASIP에 패킷을 빠른 속도로 처리하기 위해 필요한 새로운 명령어 셋을 추가하였다. 새로 추가된 명령어 셋은 "classification" 명령어 그룹과 "modification" 명령어 그룹으로 나눌 수 있으며, 각 그룹은 실행 단계(execution stage)에 위치한 각각의 기능 유닛(function unit)에 의해서 처리된다. 그리고 각각의 기능 유닛은 Verilog HDL을 통해 면적과 속도 측면에서 최적화하였으며, 이를 합성하여 면적과 동작 지연시간을 비교하였다. 또한 CKF(Compiler Known Function)을 이용하여 C 언어 레벨의 매크로 함수에 할당하였으며, 어플리케이션 프로그램에 대한 실행 싸이클을 비교 분석하여 성능 향상을 확인하였다.

• IMMUNE NETWORK
• /
• 제2권1호
• /
• pp.12-18
• /
• 2002

Interferon-${\gamma}$ (IFN-${\gamma}$) is well known as a potent inducer in monokine induced by IFN-${\gamma}$ (Mig) mRNA expression. Although lipopolysaccharide (LPS) alone is weakly effective on Mig mRNA expression. the stimulation of LPS and IFN-${\gamma}$ (LPS/IFN-${\gamma}$ simultaneously has been shown to synergize to produce a high level of Mig mRNA in mouse peritoneal macrophages. In this study, interleukin-10 (IL-10) was found to suppress the LPS/IFN-${\gamma}$-induced Mig mRNA expression in cell type- and mouse strain-specific fashion, but IFN-${\gamma}$ alone-induced Mig mRNA was unaffected by IL-10 under identical experimental conditions. The IL-10-mediated suppression of LPS/IFN-${\gamma}$-stimulated Mig mRNA expression was dependent on the concentration of IL-10, and was prevented when the agent was added 2 hours after LPS/IFN-${\gamma}$ treatment. The suppressive action of IL-10 was dependent on a protein synthesis. However, IL-10 did not reduce the stability of LPS/IFN-${\gamma}$-induced Mig mRNA. These data may have important implications for a previously unrecognized role for IL-10 as a regulator of synergistic effect of LPS on the IFN-${\gamma}$-induced expression of the Mig gene in macrophages.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 1996년도 제11차 KACG 학술발표회 Crystalline Particle Symposium (CPS)
• /
• pp.285-309
• /
• 1996

Non oxide ceramics such as nitrides of transition metals have shown significant potential for future economic impact, in diverse applications in ceramic, aerospace and electronic industries, as refractory products, abrasives and cutting tools, aircraft components, and semi-conductor substrates amid others. Combustion synthesis has become an attractive alternative to the conventional furnace technology to produce these materials cheaply, faster and at a higher level of purity. However he process os highly exothermic and manifests complex dynamics due to its strongly non-linear nature. In order to develop an understanding of this process and to study the effect of operational parameters on the final outcome, numerical modeling is necessary, which would generated essential knowledge to help scale-up the process. the model is based on a system of parabolic-hyperbolic partial differential equations representing the heat, mass and momentum conservation relations. The model also takes into account structural change due to sintering and volumetric expansion, and their effect on the transport properties of the system. The solutions of these equations exhibit steep moving spatial gradients in the form of reaction fronts, propagating in space with variable velocity, which gives rise to varying time scales. To cope with the possibility of extremely abrupt changes in the values of the solution over very short distances, adaptive mesh techniques can be applied to resolve the high activity regions by ordering grid points in appropriate places. To avoid a control volume formulation of the solution of partial differential equations, a simple orthogonal, adaptive-mesh technique is employed. This involves separate adaptation in the x and y directions. Through simple analysis and numerical examples, the adaptive mesh is shown to give significant increase in accuracy in the computations.