• 천문학회보
• /
• 제38권1호
• /
• pp.31.2-31.2
• /
• 2013

We use grid-based hydrodynamic simulations to study star formation in nuclear rings in barred galaxies. The gaseous medium is assumed to be infinitesimally thin, isothermal, and unmagnetized. To investigate various situations, we vary the total gas content in the bar regions and the bar growth time. We find that star formation rate (SFR) in a nuclear ring is determined by the mass inflow rate to the ring rather than the total gas mass in the ring. The SFR shows a strong primary burst and weak secondary bursts at early time, and declines to small values at late time. The primary burst is caused by the rapid gas infall to the ring due to the bar growth, with its duration and peak depending on the bar growth time. The secondary bursts result from re-infall of the ejected gas by star formation feedback of the primary burst. When the SFR is low, ages of young star clusters exhibit an azimuthal gradient along the ring since star formation takes place mostly near the contact points between the dust lanes and the nuclear ring. When the SFR is large, on the other hand, star formation is widely distributed throughout the whole length of the ring, with no apparent age gradient of star clusters. Regardless of SFR, star clusters have a positive radial age gradient, with younger clusters located closer to the ring, since the ring shrinks in size over time.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.700-710
• /
• 2008

A Bubble size distribution model has been developed for the numerical simulation of cryogenic high-speed cavitating flow of the turbo-pumps in the liquid fuel rocket engine. The new model is based on the previous one proposed by the authors, in which the bubble number density was solved as a function of bubble size at each grid point of the calculation domain by means of Eulerian framework with respect to the bubble size coordinate. In the previous model, the growth/decay of bubbles due to pressure difference between bubble and liquid was solved exactly based on Rayleigh-Plesset equation. However, the unsteady heat transfer between liquid and bubble, which controls the evaporation/condensation rate, was approximated by a theoretical solution of unsteady heat conduction under a constant temperature difference. In the present study, the unsteady temperature field in the liquid around a bubble is also solved exactly in order to establish an accurate and efficient numerical simulation code for cavitating flows. The growth/decay of a single bubble and growth of bubbles with nucleation were successfully simulated by the proposed model.

• 한국인터넷방송통신학회논문지
• /
• 제19권1호
• /
• pp.127-132
• /
• 2019

본 논문에서는 유비쿼터스 컴퓨팅에 의한 농수산물의 생장관리에 필요한 정보시스템을 설계하고 구축하였다. 그러기 위하여 여러 센서 시스템을 설치하고 IP Cam을 개발하여 모니터링을 구축하였다. 이러한 모니터링에 의한 농수산물의 생육조건을 직접 제어하고 관리하는 데이터베이스에 의해 IT 기술에 의한 환경관리시스템을 구축할 수 있었다. 이를 위하여 생육조건을 취합하고 실시간으로 데이터를 획득할 수 있는 여러 센서를 설치하였으며 IP Cam을 세부분으로 나누어 설계하고 제작하였으며 농수산용으로 적용함으로써 토양수분, 온도조절, 환경정보 등 각종정보를 모니터링하여 최적의 생육환경조건을 마련할 수 있었다.

• Journal of Plant Biotechnology
• /
• 제50권
• /
• pp.239-247
• /
• 2023

This study aimed to investigate the efficiency of arbuscular mycorrhizal fungi (AMF) in enhancing plant performance and bioactive compound concentrations in tomatoes (Lycopersicon esculentum Mill.). This factorial pot experiment included nine replications over 120 days of cultivation. Three AMF species (Rhizophagus prolifer, Claroideoglomus etunicatum, and Acaulospora mellea) were utilized as inoculum, while non-mycorrhizal controls with or without synthetic NPK fertilizer were compared. Interestingly, C. etunicatum KS-02 inoculations effectuated the best fruit growth and weight, which were statistically higher than those of the control without AMF. However, only fruit fresh weight was higher in plants inoculated with C. etunicatum KS-02 than those treated with the synthetic NPK fertilizer. In addition, C. etunicatum KS-02 inoculations induced a ≥ 11% increase in DDPH (1,1-diphenyl-2-picrylhydrazyl) activity, lycopene content, and carotenoid content compared to the control. This study is the first to report Claroideoglomus species' effectiveness in promoting growth, fruit yield, and bioactive compound production in L. esculentum Mill. These findings substantiate the significant potential of C. etunicatum KS-02 for tomato cultivation without the adverse effects of excessive synthetic fertilizer use.

• IMMUNE NETWORK
• /
• 제1권2호
• /
• pp.143-150
• /
• 2001

Background : Many investigators have found transforming growth factor-${\beta}1$ (TGF-${\beta}1$) to be elevated in tumors. Changes in responsiveness to TGF-${\beta}1$ have been linked to malignant transformation, tumor progression and tumor regression. Many malignant cell lines of epithelial or hematopoietic origin are refractory to the antiproliferative effects of TGF-${\beta}1$. However, a little is known about the association of TGF-${\beta}1$ with progression of malignant tumor. Methods : In this study, we measured the plasma level of TGF-${\beta}1$ in various cancer patients and evaluated the utility of plasma TGF-${\beta}1$ as a possible tumor marker. Plasma TGF-${\beta}1$ levels were measured using enzyme-linked immunosorbent assay in cancer patients and normal controls. Carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) as tumor marker were compared with TGF-${\beta}1$ in the aspects of sensitivity and specificity. Results : The mean of plasma TGF-${\beta}1$ levels was $1.219{\pm}0.834ng/ml$ in normal controls, $5.491{\pm}3.598ng/ml$ in breast cancer, $12.670{\pm}10.386ng/ml$ in lung cancer, $5.747{\pm}3.228ng/ml$ in hepatocellular carcinoma and $10.854{\pm}7.996ng/ml$ in cervical cancer. In comparison with CEA and AFP, TGF-${\beta}1$ is more sensitive. Conclusion : We conclude that the high levels of TGF-${\beta}1$ are common in the plasma of cancer patients. These results suggest that the plasma TGF-${\beta}1$ level can be a potent tumor marker in various cancer patients.

• 생물정신의학
• /
• 제12권2호
• /
• pp.143-150
• /
• 2005

목 적: 많은 연구에서 정신분열병에서 염증반응체계의 활성화와 사이토카인의 변화가 병태생리학적 및 원인적 역할을 하는 것으로 보고되어 왔으며, 여기에는 type 1 Thelper cell(Th1), type 2 T helper cell(Th2), type 3 T helper cell(Th3)의 조절 이상이 제시되고 있다. 본 연구에서는 정신분열병 환자에서 항정신병 약물 치료 전후로 Th1 사이토카인인 interleukin-12(IL-12), Th3 사이토카인인 transforming growth factor-${\beta}1$(TGF-${\beta}1$)의 혈장 농도를 측정하였다. 방 법: 23명의 정신분열병 환자군과 31명의 정상대조군에서 IL-12와 TGF-${\beta}1$ 농도를 측정하였고 정신분열병 환자군에서는 8주간 항정신병 약물로 치료 후 다시 IL-12와 TGF-${\beta}1$의 농도를 측정하였다. 또한 정신분열병 환자군에서 치료전과 8주간 치료 후, 2차례에 걸쳐 Brief psychiatric rating scale(BPRS)를 측정하였다. 결 과: 치료전 IL-12 농도와 TGF-${\beta}1$ 농도 모두 정상대조군보다 환자군에서 유의하게 높게 나타났다. 8주간의 치료 후 TGF-${\beta}1$ 농도는 유의하게 감소하여 정상대조군의 농도와 차이를 보이지 않게 된 반면, IL-12의 농도는 유의하지 않은 감소를 보였다. BPRS 점수의 변화 및 IL-12 및 TGF-${\beta}1$의 농도의 변화 사이에는 유의한 상관관계가 없었다. 결 론: 정신분열병의 병태생리학에 사이토카인의 이상이 관여할 수 있으며, TGF-${\beta}1$이 중요한 역할을 하는 것으로 생각된다.

• 한국식품영양과학회지
• /
• 제26권2호
• /
• pp.285-290
• /
• 1997

이상의 결과를 요약하연, 혈당값은 정상대조군 78{\pm}6.20mg/dl, 인슐린 비의존형 당뇨병 환자 $184{\pm}18.94mg/dl$로 인슐린 비의존형 당뇨병 환자의 혈당값이 유의적으로 높았다. IGF-I의 수준은 정상대조군 $9.32{\pm}1.48{\mu}g/ml$, 인슐린 비의존형 당뇨병 환자 $4.19{\pm}0.84{\mu}g/ml$로 인슐린 비의존형 당뇨병 환자의 IGF-I 수준이 유의적으로 낮았다. 인슐린 비의존형 당뇨병 환자의 혈청 중 IGFBP-1, -2는 증가한 반면, IGFBP-3, -4, -5는 감소하였다. IGFBP-3의 분해에 관여하는 효소는 PMSF, aprotinin, EDTA에 의해 저해되어 metal-dependent serine proteases임을 확인하였고, 효소의 크기가 대략 97,66kDa 이었으며 효소활성이 인슐린 비의존형 당뇨병 환자에게서 큼을 확인하였다.

• 한국수산과학회지
• /
• 제35권6호
• /
• pp.551-556
• /
• 2002

출산기에 임박한 조피볼락 암컷에 20mg/kg체중의 농도로 3,5, 3'-triiodo-L-thyronine $(T_{3}$)를 주사한 뒤, 출산 자어로의 호르몬 전이여부, 자어 성장과 활력을 조사하였다. 출산자어의 갑상선 호르몬을 분석한 결과,출산직후에 $T_{3}$구가 대조구 보다 높은 $T_{3}$농도를 나타냈으나, L-thyroxine $(T_{4}$)의 농도는 대조구와 유의차가 없었다. 그러나 실험기간 동안 어체내 모든 실험구의 감상선호르몬 농도는 $T_{3}$가 $T_{4}$에 비해 상대적으로 낮았고, 실험구별로는 $T_{3}$구가 대조구에 비해 높은 것을 알 수 있었다. 자어의 성장률은 대조구에 비하여 T,구에서 높았으며, 출산후 경과일수에 따라 직선적인 전장성장 경향을 나타냈다. 실험종료시 생존율은$ T_{3}$구의 자어가 대조구에 비해 높았으며, 유영활성에서도 $T_{3}$구의 자어가 대조구에 비해 유의하게 높았다. 출산직전 $T_{3}$ 모체주사는 외부영양원 섭취개시기의 자어성장 및 생리활성을 증진시키는 데 효과적인 것으로 나타났다. 이상의 연구결과로부터 출산전 모체주사를 통하여 외인성 $T_{3}$가 자어로 전이되며, 전이된 호르몬은 출산후의 자어의 초기 발달기 동안 생리적으로 긍정적인 작용을 할 것으로 추측된다.

• 대한본초학회지
• /
• 제20권4호
• /
• pp.27-31
• /
• 2005

Objectives : The anticancer response of three different types of water extracts of Zingiberaceae Curcuma longa L. tested for sarcoma 180. Only few studies carried out to investigate the effects of other contents of Curcuma longa L. in anticancer activities, therefore, in this study we have investigated the effects of other component then curcumin in Curcuma longa L. for anticancer a activities. Methods : Three different types of water extracts of Curcuma longa L. were prepared as follows. The sarcoma cells (S180) were maintained in Dulbecco's modified Eagle's medium (DMEM) and were seeded on 24-well cell culture cluster flat bottom with lid tissue culture treated non-pyrogenic polystyrene. The growth of sarcoma 180 was monitored for 1, 2 and 5 days. The sarcoma cells were pictured using inverted microscope and cell density was counted using hemocytometry. Results : After 5 days in the culture medium the results showed high growth of sarcoma 180 for control condition and the surface of CCP plates were fully covered with the cells. In case of medium in which the 10% of filtered water extract of Curcuma longa L. was added a very limited growth of sarcoma 180 was observed. The results were showed only small difference in cell density for two different concentrations of unfiltered water extracts of Curcuma longa L. whereasin case of filtered water extracts the control of sarcoma growth shows better result. Conclusion : The filtered water extracts showed the best result relatively to the unfiltered water extracts for two different concentrations. This indicates that the water extracts of Curcuma longa L. can have anticancer activities possibly without curcumin.

• Fisheries and Aquatic Sciences
• /
• 제18권4호
• /
• pp.379-385
• /
• 2015

We studied the effects of the proprietary prebiotic Immunogen$^{(R)}$ on the growth, hematology and gut microbiota of common carp fingerlings. A basal diet was formulated using common feed ingredients and supplemented with Immunogen$^{(R)}$ at concentrations of 0, 5, 10, 20 and $40g\;kg^{-1}$, each of which was tested experimentally on replicated groups of fish. The trials ran for 8 weeks. Common carp fingerlings with an initial weight of $4.82{\pm}0.05g$ were randomly distributed among the experimental tanks at a stocking density of 25 fish per tank. The experimental diets were provided thrice per day; on each occasion the fingerlings were given a weight of feed that amounted to 4% of fish biomass. At the end of the experimental period, we determined the growth performance, feed conversion ratio, hematological parameters, body composition and gut micro-flora parameters of the test fish. Inclusion of $5g\;kg^{-1}$Immunogen$^{(R)}$ in the diet significantly improved growth performance and feed utilization in comparison with controls. However, the whole-body composition of the fish was not significantly influenced by prebiotic inclusion. Inclusion of $5g\;kg^{-1}$ Immunogen$^{(R)}$ significantly increased the total bacterial and Lactobacillus counts in fish intestines, but these bacterial parameters were significantly negatively impacted by higher concentrations of the prebiotic. Red blood cells counts were increased by prebiotic dietary supplementation at concentrations of 5 and $10g\;kg^{-1}$ prebiotic. Glucose and cholesterol levels were elevated by administration of Immunogen$^{(R)}$. Thus, dietary supplementation with $5g\;kg^{-1}$ Immunogen$^{(R)}$ improved fingerling common carp growth performance and feed utilization, and beneficially influenced the gut microflora