개구부 폭과 깊이 변화에 따른 철근콘크리트 깊은 보의 파괴모드 및 내력 평가에 관한 연구

양근혁,이영호,은희창,정헌수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

The purpose of this study is to investigate the failure mode and the shear strength of reinforced concrete deep beams with rectangular openings. Fourteen deep beams which shear span-to-depth ratio(a/h) is 0.5 were tested and an equation to predict the ultimate shear strength of deep beams with rectangular openings was established by the test results.

상계치 이론을 이용한 장방형 개구부를 갖는 철근콘크리트 깊은 보의 전단내력 평가

양근혁,이영호,은희창,정헌수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

The purpose of this study is to evaluate the failure plane and the shear capacity of reinforced concrete deep beams with rectangular openings using upper bound theorem. A numerical optimization procedure programmed to obtain the minimum value of the shear capacity by adjusting the position of the instantaneous center according to various potential failure planes. The predictions obtained from the proposed method are in good agreement with experimental results.

돼지 미성숙 난포란의 회수 및 체외수정에 관한 연구

박성원,김정혁,홍승표,이지삼,정장용,박희성 진주산업대학교 농업기술연구소 1999 農業技術硏究所報 Vol.12 No.-

본 연구는 돼지의 체외수정에 있어서 난포란의 회수방법과 체외수정란 및 체외발달율을 조사하여 체외수정의 기본 원리를 밝히고자 본 연구를 수행하였다. 도축장으로부터 채집한 난소의 난포에서 흡입법, 세절법 및 흡입후세절법 등으로 난포란을 채취하여 등급별로 분류하여 회수율을 조사하였으며, 채취한 난포란은 액상정액과 정소상체미부 정액을 사용하여 체외수정을 시킨후 TCM-199 와 NCSU-23 배양액으로 체외배양을 실시하였다. 본 연구에서 얻은 결과를 요약하면 다음과 같다. 회수방법당 각각 37개의 난소에서 회수한 난포란의 수는 흡입법이 1,365개, 세절법이 1,884개 및 흡입후 세절법이 3.830개로써 난소당 난포란의 수는 각각 36.9, 50.9 및 103.5개로써 회수방법간에 유의적(P<0.05)인 차이가 있었다. 액상정액과 정소상체미부 정액을 사용하였을 때 수정율은 각각 83.0 및 83.% 로써 정액간에 유의적(P<0.05) 인 차이는 없었다. 체외수정이 이루어진 난자들의 분할율도 액상정액(60.8%) 과 정소상체미부 정액(69.0%) 간에 유의적(P<0.05) 인 차이는 없었다. 2-4세포기로의 발달율은 24.6 및 28.4%로써 배양액간에 위의적(P<0.05)인 차이는 없었으며, 상실배로의 발달율도 TCM-199 와 NCSU-23 배양액이 각각 14.8 및 24.5% 로써 이들간에 유의적(P<0.05)인 차이는 없었다. To improve the efficiency of in vitro production of embryos with follicular oocytes in pig, the recovery rates, in vitro fertilization and development, and the time required for collectng and processing oocytes by aspiration with or without slicing were evaluated comparatively. The oocytes were collected by aspiration of follicles(2-6mm) with or without slicing ovaries after aspiration, and classified into grade I-IV oocytes by the morpholoy of cumulus cells attached and the homogeneity of cytoplasmic granules. The grade Ⅰ-Ⅱ oocytes were matured invitro for 46 hours in TCM-199 and NCSU-23 supplemented with 1㎍/㎖ FSH, 2IU/㎖ hCG, 1㎍/㎖ estradiol-17 at 39℃ under 5% CO_2 in air. They were fertilized in vitro by epididymis sperm and ejaculated sperm treated with hypotaurin for 24 hours. and then the zygotes were co-cultured in vitro with pFF(porcine follicular fluid) for 7-9 days. The results obtained were as follows: The number of ocytes recovered per ovary was averaged 30.7 by aspiration, 50.8 by slicing and 103.5 by aspiration post slicing. The number of grade Ⅰ oocytes recovered was total 0.2% by aspiration, 0.1% by slicing and 0.1% by aspiration post slicing. The oocytes recovered per ovary was significantly(P<0.05) higher as recovery methods. The cleavage rates of the embryos obtained from 83.0(ejaculate sperm) and 83.1(epididymis sperm) respectively(P<0.05). In vitro developmental rates(9.9 and 18.6%) of embryos cultured in TCM-199 and NCSU-23 up to morula stage were non significantly(P<0.05) different between the culture media.

뇌성마비아의 모발내 중금속 함량 분석

안경희,김희상,유창현,윤동환,홍장혁,유승돈,이준원 경희대학교 2001 慶熙醫學 Vol.17 No.1

한우 체외수정란의 동결보존 및 핵이식에 관한 연구 : Ⅱ. 체외수저란의 동결방법이 동결.융해후 생존율에 미치는 영향 Ⅱ. Effects of Survival Rates of Frozen-Thawed Embryo Frozen Methods

정장용,박희성,홍승표,김정혁,桑潤滋,離素娟 진주산업대학교 농업기술연구소 1999 農業技術硏究所報 Vol.12 No.-

본 연구는 수정란의 동결기법을 확립하고자 배반포기에 있는 한우 체외수정란을 이용하여 유리화 및 직접이식 동결방법으로 동결을 실시하여 동결·융해후 생존성, 동해방지제의 종류, 평형 및 할구의 손상여부 등에 대한 영향을 조사한 결과는 다음과 같다. 유리화 동결방법중 GESD-VS와 EFS 용액을 동해방지제로 사용하였을 때 동결·융해 수정란의 생존율은 각각 69.8 및 37.3%로써 이들간에 유의적(P<0.05)인 차이가 있었으며, 동결기를 이용한 직접이식 동결법은 생존율이 56.0%로써 유리화 동결방법과는 유의적(P<0.05)인 차이가 없었다. 동결·융해후 생존한 수정란의 발달율은 GESD-VS용액을 사용하였을때가 53.4%로써 EFS용액을 사용하였을때의 24.0%보다는 유의적(P<0.05)으로 높게 나타났다. 1 및 2단계 평형시 단계별 생존율은 각각 11.7 및 23%로써 이들간에 유의적(P<0.05)인 차이가 없었으며, 동결·융해 수정란의 발달율도 각각 10 및 16.8%로써 평형방법간에 유의적(P<0.05)인 차이가 없었다. 신선수정란, 유리화 동결수정란 및 동결비를 이용한 직접이식 동결법으로 동결하였을 때 동결·융해 수정란의 할구수는 각각 98.7±2.3개, 69.1±2.6 및 84.2±2.7개로써 동결방법들간에 유의적(P<0.05)으로 할구수의 차이가 많았다. This study was carried out to investigate the effect of cryoprotectants, equilibration step, number of blastomeres on survival and developmental rates of bovine in vitro fertilized blastocysts(Korean native cattle) frozen/thawed by vitrification and frozen for direct transfer(1.8M ethylene glycol). The bovine oocytes were collected from 2-5mm follicles, matured for 24hrs in 5% CO_2 incubator and then fertilized with cauda epididymis sperm. Blastocyst at day 7-9 ater IVF were frozen in vitrification and frozen for direct transfer(1.8M ethylene glycol). Survival and developmental rates of frozen-thawed IVF embryos were examined. The results were as follow ; The survival rate of IVF blastocyst after vitrification in GESD-VS, EFS and 1.8M ethylene glycol solution were 69.8, 37.3 and 56.0%, respectively(P<0.05). When equilibrated in 1 step(11.7%) was similar to the result from 2 step(23.0%), and no significantly(P<0.05) different between the equilibrated steps. The number of blastomere at blastomere at blastocyst of bovine embryos frozen/thawed in fresh, vitrification and freezing for direct transfer were 98.7±2.3, 69.1±2.6 and 84.2±2.7, respectively, and were significantly(P<0.05) different between the freezing methods.

Development of novel on-line capillary gas chromatography-based analysis method for volatile organic compounds produced by aerobic fermentation

Lee, Hyeok-Won,Park, Jung-Ho,Lee, Hee-Suk,Kim, Chun-Suk,Lee, Jin-Gyeom,Kim, Won-kyo,Ryu, Kyoung-Hwa,Ahn, Jung-Oh,Lee, Eun-Gyo,Kim, Seon-Won,Jeon, Jong-Min,Yang, Yung-Hun,Choi, Eui-Sung,Lee, Hong-Weon Society for Bioscience and Bioengineering, Japan 2019 Journal of bioscience and bioengineering Vol. No.

<P>Many volatile compounds, such as isoprene, a precursor used in the synthesis of natural rubber, have been produced through fermentation using genetically engineered microorganisms. Despite this biotechnological success, measuring the concentrations of volatile compounds during fermentation is difficult because of their high volatility. In current systems, off-line analytical methods usually lead to product loss, whereas on-line methods raise the production cost due to the requirement of complex devices. Here, we developed a novel on-line gas chromatography (GC)-based system for analyzing the concentration of isoprene with the aim to minimize the cost and requirement for devices as compared to current strategies. In this system, a programmable logic controller is used to combine conventional GC with a syringe pump module (SPM) directly connected to the exhaust pipe of the fermentor, and isoprene-containing samples are continuously pumped from the SPM into the GC using an air cylinder recycle stream. We showed that this novel system enables isoprene analysis during fermentation with convenient equipment and without the requirement of an expensive desorption tube. Furthermore, this system may be extended to the detection of other volatile organic compounds in fermentation or chemical processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This system analyzes the concentration of isoprene in aerobic fermentation. </LI> <LI> PLC is used to combine conventional GC with SPM directly connected to fermenter. </LI> <LI> Produced isoprene is continuously analyzed using the GC. </LI> <LI> This system may be extended to the detection of other volatile organic compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhancement of L-Threonine Production by Controlling Sequential Carbon-Nitrogen Ratios during Fermentation

( Hyeok-won Lee ),( Hee-suk Lee ),( Chun-suk Kim ),( Jin-gyeom Lee ),( Won-kyo Kim ),( Eun-gyo Lee ),( Hong-weon Lee ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.2

Controlling the residual glucose concentration is important for improving productivity in L-threonine fermentation. In this study, we developed a procedure to automatically control the feeding quantity of glucose solution as a function of ammonia-water consumption rate. The feeding ratio (R_C/N) of glucose and ammonia water was predetermined via a stoichiometric approach, on the basis of glucose-ammonia water consumption rates. In a 5-L fermenter, 102 g/l L-threonine was obtained using our glucose-ammonia water combined feeding strategy, which was then successfully applied in a 500-L fermenter (89 g/l). Therefore, we conclude that an automatic combination feeding strategy is suitable for improving L-threonine production.

Toll-Like Receptor 4-Linked Janus Kinase 2 Signaling Contributes to Internalization of <i>Brucella abortus</i> by Macrophages

Lee, Jin Ju,Kim, Dong Hyeok,Kim, Dae Geun,Lee, Hu Jang,Min, Wongi,Rhee, Man Hee,Cho, Jae Youl,Watarai, Masahisa,Kim, Suk American Society for Microbiology 2013 Infection and immunity Vol.81 No.7

<P><I>Brucella abortus</I> is an intracellular pathogen that uses a crafty strategy to invade and proliferate within host cells, but the distinct signaling pathways associated with phagocytic mechanisms of <I>B. abortus</I> remain unclear. The present study was performed to test the hypothesis that Toll-like receptor 4 (TLR4)-linked signaling interacting with Janus kinase 2 (JAK2) plays an essential role in <I>B. abortus</I> phagocytosis by macrophages. The effects of TLR4-JAK2 signaling on <I>B. abortus</I> phagocytosis in murine macrophage RAW 264.7 cells were observed through an infection assay and confocal microscopy. We determined that the uptake of <I>B. abortus</I> was negatively affected by the dysfunction of TLR4 and JAK2. F-actin polymerization detected by flow cytometry and F-actin assay was amplified for <I>B. abortus</I> entry, whereas that event was attenuated by the disruption of TLR4 and JAK2. Importantly, JAK2 phosphorylation and actin skeleton reorganization were suppressed immediately after <I>B. abortus</I> infection in bone marrow-derived macrophages (BMDMs) from TLR4<SUP>−/−</SUP> mice, showing the cooperation of JAK2 with TLR4. Furthermore, small GTPase Cdc42 participated in the intermediate pathway of TLR4-JAK2 signaling on <I>B. abortus</I> phagocytosis. Consequently, TLR4-associated JAK2 activation in the early cellular signaling events plays a pivotal role in <I>B. abortus</I>-induced phagocytic processes in macrophages, implying the pathogenic significance of JAK2-mediated entry. Here, we elucidate that this specific phagocytic mechanism of <I>B. abortus</I> might provide achievable strategies for inhibiting <I>B. abortus</I> invasion.</P>

Helicobacter pylori 감염의 박멸후 발생한 역류성 식도염

이준호,김학양,유재영,박충기,김종혁,이종민,김용범,서지영,김재삼,유희승 대한소화기내시경학회 1998 Clinical Endoscopy Vol.18 No.5

Helicobacter pylori infection causes chronic gastritis and its well documented con- sequences are peptic ulcer disease and gastric neoplasia. As duodenal ulcer is often associated with gastroesophageal reflux disease and antral gastritis is a frequent finding in patients with reflux disease, H. pylori infection may be a common cause of both conditions. Recent studies reveal that H. pylori has no role in the pathogenesis of reflux esophagitis. Furthermore, there are some arguments on whether H. pylori infection may have a protective role in reflux esophagitis. We have experienced two cases of reflux esophagitis after cure of H. pylori infection. H. pylori eradication therapy was performed in two patients who have gastric and/or duodenal ulcer with omeprazole and two anti-biotics (clarithromycin and amoxicillin). After cure of H. pylori infection, reflux esophagitis was demonstrated in these patients by endoscopy.

Tumor suppressor p53 plays a key role in induction of both tristetraprolin and <i>let-7</i> in human cancer cells

Lee, Ji Young,Kim, Hyo Jeong,Yoon, Nal Ae,Lee, Won Hyeok,Min, Young Joo,Ko, Byung Kyun,Lee, Byung Ju,Lee, Aran,Cha, Hee Jeong,Cho, Wha Ja,Park, Jeong Woo Oxford University Press 2013 Nucleic acids research Vol.41 No.11

<P>Tristetraprolin (TTP) and <I>let-7</I> microRNA exhibit suppressive effects on cell growth through down-regulation of oncogenes. Both TTP and <I>let-7</I> are often repressed in human cancers, thereby promoting oncogenesis by derepressing their target genes. However, the precise mechanism of this repression is unknown. We here demonstrate that p53 stimulated by the DNA-damaging agent doxorubicin (DOX) induced the expression of <I>TTP</I> in cancer cells. TTP in turn increased <I>let-7</I> levels through down-regulation of <I>Lin28a</I>. Correspondingly, cancer cells with mutations or inhibition of p53 failed to induce the expression of both <I>TTP</I> and <I>let-7</I> on treatment with DOX. Down-regulation of <I>TTP</I> by small interfering RNAs attenuated the inhibitory effect of DOX on <I>let-7</I> expression and cell growth. Therefore, TTP provides an important link between p53 activation induced by DNA damage and <I>let-7</I> biogenesis. These novel findings provide a mechanism for the widespread decrease in TTP and <I>let-7</I> and chemoresistance observed in human cancers.</P>