• Animal Bioscience
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• 제35권12호
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• pp.1921-1928
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• 2022

Objective: This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. Methods: A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Results: Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. Conclusion: These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.

• Nutritional Sciences
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• 제8권1호
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• pp.10-15
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• 2005

An increase in serum cholesterol is directly associated with high incidences of cardiovascular diseases (CVD) and atherosclerosis. Serum lipid profiles are highly dependent on dietary fatty acids and age. The purpose of this study was to examine the age-related effects of polyunsaturated/saturated fatty acid ratios and antioxidant supplementation under the control of the dietary peroxidizability index (PI) value on serum lipid profiles in rats. While the PI level of dietary fatty acids was controlled at 81.22, the P/S ratios of fatty acids were 0.38 and 4.81 (LP and HP). The diets were supplemented with a vitamin E 1000 mg/kg diet and a selenium 2.5 mg/kg diet (LPS and HPS). Female Sprague-Dawley rats ages 3 weeks (young) and 16 weeks (adult) were fed four different experimental diets for 4 weeks. The serum triglyceride concentration of LPS was significantly higher in young rats than in adult rats. The total-cholesterol concentration of LP and HPS were higher in young rats than in adult rats. The high-density lipoprotein-cholesterol (HDL-C) concentration of LP, LPS and HP was higher in adult rats than in young rats. The low-density lipoprotein-cholesterol (LDL-C) concentration was higher in young rats than in adult rats. T-C/HDL-C and LDL-C/HDL-C ratios were much higher in young rats than in adult rats. In conclusion, P/S ratios and antioxidant supplementation did not affect T-C/HDL-C and LDL-C/HDL-C ratios as risk factors of CVD in adult rats when we controlled the PI value in the diet Probably, the invisible and confounding effects of dietary PI value implicate the beneficial roles of dietary P/S ratios and antioxidants in CVD. Accordingly, controlling the dietary PI value may be advantageous to lower the risk of CVD in adult rats.

• 대한수학회지
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• 제45권5호
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• pp.1379-1391
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• 2008

Let k be an imaginary quadratic field, ${\eta}$ the complex upper half plane, and let ${\tau}{\in}{\eta}{\cap}k,\;q=e^{{\pi}{i}{\tau}}$. For n, t ${\in}{\mathbb{Z}}^+$ with $1{\leq}t{\leq}n-1$, set n=${\delta}{\cdot}2^{\iota}$(${\delta}$=2, 3, 5, 7, 9, 13, 15) with ${\iota}{\geq}0$ integer. Then we show that $q{\frac}{n}{12}-{\frac}{t}{2}+{\frac}{t^2}{2n}{\prod}_{m=1}^{\infty}(1-q^{nm-t})(1-q^{{nm}-(n-t)})$ are algebraic numbers.

• 생명과학회지
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• 제26권8호
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• pp.875-880
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• 2016

진핵세포의 원형질막은 외부환경으로부터 세포를 격리하는 물리적인 장벽뿐만 아니라, 선택적 물질수송, 신호전달등 중요한 기능을 수행한다. 원형질막의 세포질쪽 지질층은 주로 Phosphatidylethanolamine (PE), Phosphatidylserine (PS), Phosphatidylinositides (PIs) 등의 인지질로 구성되어 있는데, 다양한 단백질들이 이들과 직접 결합하거나 이들의 성질을 이용해 원형질막으로 위치된다. 본 연구에서는 원형질막의 안쪽 지질층에 존재하는 특정 인지질과 결합하여, 원형질막에 위치되는 단백질을 과발현시켰을 때 나타나는 세포의 모양변화를 분석하였다. 이를 위해 PS와 PI등과의 선택적 결합으로 원형질막에 위치하는 단백질들과 소수성 또는 정전기적 상호작용으로 원형질막으로 위치되는 단백질들을 HEK293T세포에 과발현시켜 보았다. 그 결과, 대조군으로 사용한 EGFP 단백질과 PI4P에 선택적으로 결합하는 EGFP-P4M-SidM단백질의 발현은 세포의 모양변화를 유도하지 않았다. 반면, PI(4,5)P₂에 결합하는 EGFP-PLCδ1(PH), PI(3,4,5)P₃에 결합하는 EGFP-AKT1(PH), PI4P와 PI(4,5)P₂에 결합하는 OSH2(PH)x2-EGFP의 발현은 세포의 크기가 줄어드는 수축현상이 일어나면서, Lamilapodia나 Filopodia가 형성되는 것을 확인할 수 있었다. 반면에, PS결합을 통해 원형질막에 위치되는 Lact-C2-EGFP과 소수성결합에 의해 원형질막에 위치되는 ApPDE4 long-form인 L(N20)-EGFP이나, 정전기적인 결합을 통해 원형질막으로 위치되는 ApPDE4 short-form인 S(N-UCR1-2)-EGFP단백질의 경우는 세포의 크기가 줄어드는 수축현상은 일어나지만 Lamilapodia나 Filopodia와 같은 모양변화는 나타나지 않는 것을 확인할 수 있었다. 본 연구를 통해, 특정 인지질에 결합하여 원형질막에 위치되는 단백질들이 각각의 인지질 결합 특성에 따라 분류 가능한 세포의 모양변화가 일어남을 확인할 수 있었다.

• Parasites, Hosts and Diseases
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• 제49권2호
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• pp.115-123
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• 2011

Toxoplasma gondii Korean isolate (KI-1) tachyzoites were inoculated intraduodenally to BALB/c mice using a silicon tube, and the course of infection and immune responses of mice were studied. Whereas control mice, that were infected intraperitoneally, died within day 7 post-infection (PI), the intraduodenally infected mice survived until day 9 PI (infection with $1{\times}10^5$ tachyzoites) or day 11 PI (with $1{\times}10^6$ tachyzoites). Based on histopathologic (Giemsa stain) and PCR (B1 gene) studies, it was suggested that tachyzoites, after entering the small intestine, invaded into endothelial cells, divided there, and propagated to other organs. PCR appeared to be more sensitive than histopathology to detect infected organs and tissues. The organisms spread over multiple organs by day 6 PI. However, proliferative responses of splenocytes and mesenteric lymph node (MLN) cells in response to con A or Toxoplasma lysate antigen decreased significantly, suggesting immunosuppression. Splenic $CD4^+$ and $CD8^+$ T-Iymphocytes showed decreases in number until day 9 PI, whereas IFN-${\gamma}$ and IL-10 decreased slightly at day 6 PI and returned to normal levels by day 9 PI. No TNF-${\alpha}$ was detected throughout the experimental period. The results showed that intraduodenal infection with KI-1 tachyzoites was successful but did not elicit significant mucosal immunity in mice and allowed dissemination of T. gondii organisms to systemic organs. The immunosuppression of mice included reduced lymphoproliferative responses to splenocytes and MLN cells to mitogen and low production of cytokines, such as IFN-${\gamma}$, TNF-${\alpha}$, and IL-10, in response to T. gondii infection.

• 대한치과의사협회지
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• 제48권5호
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• pp.371-378
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• 2010

The objective of this study was to compare the effectiveness of essential oil mouthrinse and interdental brush for oral hygiene in orthodontic patient. 90 patients, with fixed orthodontic appliances, were divided into 3 groups(Group 1: patients who had only used toothbrush, group 2: toothbrush + essential oil mouthrinse, group 3: toothbrush + interdental brush). Then, plaque index(PI) and gingival index(GI) were evaluated at before(T0), 3 weeks after(Tl) and 6 weeks after(T2) the experiment. The present study revealed the following conclusions: (1) There was statistically significant decrease in PI and GI of groups 2 and 3 comparing to those of group 1 during 6 weeks.(p<0.05) (2) There was no significant difference in the level of decrease in PI and GI between group 2 and group 3.(p<0.05) The present study thus implied that use of mechanical or chemical aid such as interdental brush and mouth rinse in addition to toothbrushing may help maintaining oral hygiene in patients undergoing fixed orthodontic treatment for prolonged duration.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.633-636
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• 2008

A series novel films of polyimide (PI) and co-polyimide (Co-PI) containing fluorine with colorless, flexible properties was prepared by a two-step process from various commercial aromatic monomers such as 4,4'-(Hexafluoro iso propylidene) diphthalic anhydride (6FDA), 2,2'-Bis(Trifluoromethyl) benzidine (TFDB), 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (AH6FP) and Bis(4-(3-aminophenoxy)phenyl)sulfone (BAS). Furthermore, these obtained transparent and flexible Co-PI films exhibited excellent thermal stability with the decomposition temperature (at 5% weight loss) around of $500^{\circ}C$ and the glass transition temperature ($T_g$) in the range of $275-350^{\circ}C$.

• 수산해양기술연구
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• 제40권2호
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• pp.138-143
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• 2004

제주대학교 실습선 아라호에 정착된 능동형 횡동요 감쇠장치의 성능에 관해 연구하기 위하여 33$^{\circ}$00‘.44”N, 125$^{\circ}$59’.88 ”E 위치에서 선박을 정지한 후, 횡동요 감쇠장치를 정지 (Passive A.R.T), 작동 (Active A.R.T)을 했을 때 경사계에 의한 횡동요각 및 종동요각, 풍속계에 의한 풍속의 변화와 그리고 선박이 항해 중에 감쇠장치의 작동을 정지(Passive A.R.T), 작동(Active A.R.T) 했을 때 의 능동형 횡동요 감쇠장치의 성능을 분석한 결과에 대해 요약하면 다음과 같다. 1. 선박이 정지했을 때 횡동요 감쇠장치를 정지, 작동한 경우 횡동요각의 평균진폭 (Average Amplitude of Roll) 은 각각 8.30$^{\circ}$, 4.37$^{\circ}$, 횡동요각의 유의진폭(Significant Amplitude of Roll $_{{\pi}{1/3}}$)은 각각 10.10$^{\circ}$, 5.30$^{\circ}$으로 나타났다. 2. 선박이 항해 중 일 때에는 횡동요각의 평균진폭 (Average Amplitude of Roll)은 각각 5.01$^{\circ}$, 4.36$^{\circ}$, 횡동요각의 유의진폭 (Significant Amplitude of Roll$^{\circ}$) 은 각각 5.50$^{\circ}$, 5.10$^{\circ}$으로 각각 나타났다. 3. 횡동요 감쇠장치는 선박이 정치했을 때에는 47.5%, 선박이 운항 했을 때는 12.7% 정도의 감쇠 효율을 보여서 정지했을 때 그 효율이 높은 것으로 나타났다. 4. 횡동요 감쇠 장치는 종동요(Pitching)에 대해서는 거의 영향을 미치지 않았다.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.417-423
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• 2011

A series of new quinoxaline-based thiophene copolymers (PQx2T, PQx4T, and PQx6T) was synthesized via Yamamoto and Stille coupling reactions. The $M_ws$ of PQx2T, PQx4T, and PQx6T were found to be 20,000, 12,000, and 29,000, with polydispersity indices of 2.0, 1.2, and 1.1, respectively. The UV-visible absorption spectra of the polymers showed two distinct absorption peaks in the ranges 350 - 460 nm and 560 - 600 nm, which arose from the ${\pi}-{\pi}^*$ transition of oligothiophene units and intramolecular charge transfer (ICT) between a quinoxaline acceptor and thiophene donor. The HOMO levels of the polymer ranged from -5.37 to -5.17 eV and the LUMO levels ranged from -3.67 to -3.45 eV. The electrochemical bandgaps of PQx2T, PQx4T, and PQx6T were 1.70, 1.71, and 1.72 eV, respectively, thus yielding low bandgap behavior. PQx2T, PQx4T, and PQx6T had open circuit voltages of 0.58, 0.42, and 0.47 V, and short circuit current densities of 2.9, 5.29 and 9.05 mA/$cm^2$, respectively, when $PC_{71}BM$ was used as an acceptor. For the solar cells with PQx2T-PQx6T:$PC_{71}BM$ (1:3) blends, an increase in performance was observed in going from PQx2T to PQx6T. The power conversion efficiencies of PQx2T, PQx4T, and PQx6T devices were found to be 0.69%, 0.73%, and 1.80% under AM 1.5 G (100 mW/$cm^2$) illumination.

• 정보보호학회논문지
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• 제33권5호
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• pp.787-799
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• 2023

가정에서 IoT 장비가 많이 활용되면서, IoT 장비를 통합하여 사용자의 편의에 맞게 사용하는 IoT automation system을 향한 관심도 많아졌다. IoT automation system에서는 사전 정의된 자동화규칙에 따라 IoT 장비의 정보를 수집하고, IoT 장비가 작동한다. 하지만 공격자는 패킷을 지연시켜 실제 상태와 시스템에서 인식한 상태의 불일치가 되는 시간을 만든다. 이 시간 동안 시스템은 사전 정의한 자동화 규칙대로 동작하지 않는다. 제안된 지연공격 탐지방법이 일부 있지만, 트래픽량이나 배터리에 민감한 IoT system에 적용하기에 제한사항이 있다. 본 논문에서는 IoT 시스템에 적용할 수 있는 실용적인 패킷 지연 공격 탐지 방법을 제시한다. 제안 방법은 메시지를 전송할 때, 메세지의 전송을 알리는 패킷을 브로드캐스트로 발송함으로써 서버가 이벤트의 발생을 인지할 수 있도록 한다. 평가를 위하여 Raberry pi로 구현된 IoT system을 구성하고, 패킷 지연 공격에 대하여 평균2.2초이내로탐지할 수 있음을 보였다. 실험 결과 소모 전류 Overhead는 초당 평균 2.5 mA, 트래픽 Overhead는 15% 발생하였고, 기존 제안된 탐지방법보다 효율적으로 Delay attack을 탐지할 수 있음을 밝혔다.