• 한국임상수의학회지
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• 제30권3호
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• pp.178-185
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• 2013

본 연구는 젖소에서 산유량이 분만 후 건강과 번식 능력에 미치는 영향에 대하여 조사하였다. 젖소 목장 6개소의 총 1,060두로부터 산유 성적, 신체충실지수(BCS), 분만 후 질병 및 번식 능력에 대한 자료를 수집하였으며, 모든 자료는 305일 산유량에 기준으로 대조군(< 10,000 kg, n = 445)과 고산유량군(${\geq}$ 10,000 kg, n = 615)으로 구분하였다. 유지방, 유단백 및 BCS는 분만 후 5개월 동안 대조군에 비해 고산유량군에서 낮았다(p < 0.01). 자궁내막염 발생은 대조군(35.1%)에 비해 고산유량군(29.6%)에서 낮은 경향이 있었으나(p = 0.06), 난소낭종의 발생은 대조군(15.3%)에 비해 고산유량군(28.6%)에서 증가되었다(p < 0.0001). 번식 호르몬 처리를 받은 소의 비율은 대조군(56.6%)에 비해 고산유량군(62.4%)이 높은 경향을 보였으나(p = 0.06), 첫 수정 수태율은 대조군(35.2%)에 비해 고산유량군(30.2%)에서 낮은 경향을 나타내었다(odds ratio = 0.78, p = 0.07). 분만 후 210일까지 임신율은 대조군에 비해 고산유량군에서 낮았으며(hazard ratio = 0.84, p = 0.04), 이것이 분만 후 평균 임신 간격의 연장(20일)을 초래하였다. 결론적으로, 젖소에서 고산유량은 유지방, 유단백질 및 BCS의 저하, 난소낭종의 발생 증가 및 번식 호르몬의 사용 증가로 번식 능력의 감소를 초래하였다.

• Toxicological Research
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• 제24권1호
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• pp.29-36
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• 2008

The present study investigated the anti-proliferative and chemosensitizing effects of Crinum asiaticum var. japonicum against multi-drug resistant (MDR) cancer cells. The 80% methanol extract, chloroform ($CHCl_3$) fraction and butanol (BuOH) fraction of C. asiaticum inhibited the growth of mitoxantrone (MX) resistant HL-60 (HL-60/MX2) cells. When HL-60/MX2 cells were treated with the $CHCl_3$ and BuOH fractions, DNA ladder and sub-G1 hypodiploid cells were observed. Furthermore, the fractions reduced BcI-2 mRNA levels, whereas Bax mRNA levels were increased. These results suggest that the inhibitory effect of C. asiaticum on the growth of the HL-60/MX2 cells might arise from the induction of apoptosis. Treatment of HL-60/MX2 cells with the fractions markedly decreased the mRNA levels of the multi-drug resistance protein-1 and breast cancer resistance protein. The $CHCl_3$ fraction and hexane fraction increased MX accumulation in HL-60/MX2 cells. These results imply that the $CHCl_3$ fraction of C. asiaticum plays a pivotal role as a chemosensitizer. We suggest that components of C. asiaticum might have a therapeutic potential for the treatment of MDR leukemia.

• 한국육종학회지
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• 제40권4호
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• pp.443-446
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• 2008

'강백'은 국립식량과학원 벼맥류부에서 2006년도에 육성한 벼흰잎마름병 $K_{3a}$에 저항성인 국내 최초 품종으로 주요특성과 수량성을 요약하면 다음과 같다. 1. '강백'의 평균 출수기는 8월 11일로 '남평벼'보다 4일 빠른 중생종이다. 2. 주당수수, 수당립수, 등숙비율 및 정현비율은 '남평벼'와 비슷하며 현미천립중은 다소 가벼운 중립종이다. 3. 심복백은 거의 없고 '남평벼' 수준으로 맑고 투명하며 도정율, 아밀로스 및 단백질함량은 '남평벼'와 비슷하며 밥맛은 떨어지는 편이다. 4. 도열병은 중도저항성을 보였으며 흰잎마름병 $K_1{\sim}K_3$ 및 새로운 변이균 $K_{3a}$에 저항성인 국내 최초 자포니카 품종이나 줄무늬잎마름병, 오갈병 및 검은줄오갈병에는 약하고, 충에 대한 저항성은 없다. 5. '강백'의 쌀수량은 보통기 표준재배에서 5.28MT/ha으로 '남평벼'보다 7% 낮은 수량을 보였고 이모작재배에서 4.01 MT/ha, 만식재배에서는 4.34MT/ha의 수량을 보였다.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1311-1315
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• 2006

Aminocyclitol antibiotic validamycin A, a prime control agent for sheath blight disease of rice plants, is biosynthesized by Streptomyces hygroscopicus var. limoneus. Within the validamycin biosynthetic gene cluster, vldBC forms an operon of vldABC with vidA, the gene encoding 2-epi-5-epi-valiolone synthase. Biochemical studies, employing the recombinant proteins from Escherichia coli, established VldB and VldC as D-glucose $\alpha$-1-phosphate uridylyltransferase and glucokinase, respectively. This finding substantiates that the validamycin biosynthetic gene cluster harbors genes encoding the enzymes for UDP-glucose formation from glucose. Therefore, we propose that validamycin biosynthesis employs its own catalysts to generate UDP-glucose, but not depending on the primary metabolism.

• 식물조직배양학회지
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• 제27권6호
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• pp.475-478
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• 2000

상추에 particle bombardment를 이용한 배추 Glutathione Reductase (GR)유전자의 형질전환효율 향상 및 형질전환체의 유전분석에 관한 실험을 수행하여 얻은 결과를 요약하면 다음과 같다. Particle bombardment 이용시 사출 전 4시간, 사출 후 16시간 동안 삼투조절제인 0.6M serbitolfmannitol 을 처리하여 형질전환시킨 상추 자엽조직에서 GUS 반응 spot이 가장 많았다. 0.3, 0.6, 1.5 kbp로 나타나는 3가지 종류의 primer를 사용하여 PCR한 결과 각각의 primer에 homology를 타나내는 band를 확인하여 355 promoter와 BcGRl유전자가 삽입이 된 것을 확인하였다. 형질전환된 상추의 자식 종자를 채종하여 kanamycin 200mg/L이 첨가된 MS배지에 파종하여 형질전환시키지 않은 상추의 자식 종자와 비교해 본 결과, 형질전환된 상추의 종자에서 발아된 유묘의 약 70%정도가 kanamycin에 대해 내성을 나타내었다.

• 대한치과기공학회지
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• 제45권4호
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• pp.87-94
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• 2023

Purpose: This study aimed to observed changes in the shape of dental barrels based on application time. Machinability measures the angle of alloy specimens. Polishing performance measures the surface roughness of alloy specimens. Methods: The dental barrel polishing equipment used in this study was a Snow Barrel (DK Mungyo). Three types of cobalt-chromium alloys for partial dentures were used as specimens (BC CAST R [BP]; Bukwang, Vera PDI [VP]; Aalbadent, and GM 800+ [GP]; Dentaurum). Specimens were prepared in the form of plates (10 mmx10 mmx2 mm). Dental barrel polishing was performed at 450 rpm for 60 minutes with intervals of 5 minutes. The processing angle was measured using a microscope (SZ61; Olympus). Results: For the angle measurement, the VPC specimen was measured at 78.64°, 36.00° for the VP60 specimen, 79.57° for the BP control (BPC) specimen, 28.07° for the BP60 specimen, 75.01° for the GPC specimen, and 39.92° for the GP60 specimen. For the surface roughness measurements, the average surface roughness of the VPC and VP15 specimens were 1.09 ㎛ and 0.26 ㎛, respectively. The average surface roughness of the BPC and BP20 specimens were 1.77 ㎛ and 0.29 ㎛, respectively. The average surface roughness of the GPC and GP15 specimens were 1.08 ㎛ and 0.27 ㎛. Conclusion: The results were excellent after about 20 minutes of dental barrel polishing conditions presented in this study.

• 대한전자공학회논문지SD
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• 제47권7호
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• pp.61-69
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• 2010

본 논문에서는 기존 폴딩 구조의 A/D 변환기(ADC)가 지닌 경계조건 비대칭 오차를 극복하기 위해 홀수개의 폴딩 블록을 사용한 1.2V 8b 800MSPS CMOS ADC를 제안한다. 제안하는 ADC는 저 전력소모를 위해 폴딩 구조에 저항열 인터폴레이션 기법을 적용하고, 높은 folding rate(FR=9)를 극복하기 위해 cascaded 폴딩 구조를 채택하였다. 특히 폴딩 ADC의 주된 문제인 아날로그 신호의 선형성 왜곡과 offset 오차 감소를 위해 홀수개의 폴딩 블록을 사용하는 신호처리 기법을 제안하였다. 또한 스위치를 사용한 ROM 구조의 인코더를 채택하여 $2^n$ 주기를 가지지 않는 디지털 코드를 일반적인 바이너리 코드로 출력하였다. 제안하는 ADC는 $0.13{\mu}m$ 1P6M CMOS 공정을 사용하여 설계되었으며, 유효면적은 870um$\times$980um이다. 입력주파수 10MHz, 800MHz의 변환속도에서 150mW의 낮은 전력소모 특성을 보이며 SNDR은 44.84dB (ENOB 7.15bit), SFDR은 52.17dB의 측정결과를 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권2호
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• pp.89-95
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• 2003

In this paper, we have designed and fabricated high conversion gain Q-band active sub-harmonic mixers for a receiver of millimeter wave wireless communication systems. The fabricated active sub-harmonic mixer uses 2nd harmonic signals of a low local oscillator (LO) frequency. The fabricated mixer was successfully integrated by using $0.1{\;}\mu\textrm{m}$GaAs pseudomorphic high electron mobility transistors (PHEMTs) and coplanar waveguide (CPW) structures. From the measurement, it shows that maximum conversion gain of 4.8 dB has obtained at a RF frequency of 40 GHz for 10 dBm LO power of 17.5 GHz. Conversion gain from the fabricated sub-harmonic mixer is one of the best reported thus far. And a phase noise of the 2nd harmonic was obtained -90.23 dBc/Hz at 100 kHz offset. The active sub-harmonic mixer also ensure a high degree of isolations, which are -35.8 dB from LO-to-IF and -40.5 dB from LO-to-RF, respectively, at a LO frequency of 17.5 GHz.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.492-500
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• 2019

Equal channel angular pressing(ECAP) is a severe plastic deformation technique capable of introducing large shear strain in bulk metal materials. However, if an ECAPed material has an inhomogeneous microstructure and anisotropic mechanical properties, this material is difficult to apply as structural components subjected to multi-axial stress during use. In this study, extruded oxygen-free copper(OFC) rods with a large diameter of 42 mm are extruded through ECAP by route Bc up to 12 passes. The variations in the microstructure, hardness, tensile properties, and microstructural and mechanical homogeneity of the ECAPed samples are systematically analyzed. High-strength OFC rods with a homogeneous and equiaxed-ultrafine grain structure are obtained by the repeated application of ECAP up to 8 and 12 passes. ECAPed samples with 4 and 8 passes exhibit much smaller differences in terms of the average grain sizes on the cross-sectional area and the tensile strengths along the axial and circumferential directions, as compared to the samples with 1 and 2 passes. Therefore, it is considered that the OFC materials, which are fabricated via the ECAP process with pass numbers of a multiple of 4, are suitable to be applied as high-strength structural parts used under multi-axial stress conditions.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.63-63
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• 2020

Rice stripe virus (RSV) disease is one of the major constraints in rice production, transmitted by the small brown planthopper (SBPH; Laodelphax striatellus). Upon RSV infection, plants develop typical symptoms, which include chlorosis and weakness of newly emerged leaves, white and yellow spots, stripe on leaves, and necrotic and wilting leaves, resulting in plant growth inhibition, oxidative damage that may culminate in programmed cell death (PCD) and plant death in severe epidemics. Although RSV-resistant quantitative trait loci (QTLs), Stv-a, Stv-b, and Stv-bi, were mapped using various resistant varieties, one RSV-resistant gene, OsSOT1, has been identified so far. In this study, we used the rice cultivar Zenith, known to carry Stv-b, to investigate novel RSV-genes through fine mapping. Therefore, we crossed Zenith (Donor parent, RSV resistant) with Ilpum (Recurrent parent, RSV susceptible) to fine-map using a BC₂F₂ population of 2100 plants. Chromosome segment introgression lines that were heterozygous at a different region were selected, two types of heterozygous lines showed an heterozygous genotype between Sid2 and Sid75 to Indel9 and RM6680. Interestingly, we identified qSTV11^Z region harboring Stv-b, covering about 171-kb region between the InDel markers Sid75 and Indel8. The localization of qSTV11^Z provides useful information that could be used for marker-assisted selection and determination of genetic resources in rice breeding.