Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of ‘Bonus’ tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in NO3-N, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato.

The impact of different mixing methods and sintering temperatures on the microstructure and piezoelectric properties of PZNN-PZT ceramics is investigated. To improve the sinterability and piezoelectric properties of these ceramics, the composition of 0.13Pb((Zn0.8Ni0.2)1/3Nb2/3)O3-0.87Pb(Zr0.5Ti0.5)O3 (PZNN-PZT) containing a Pb-based relaxor component is selected. Two methods are used to create the powder for the PZNN-PZT ceramics. The first involves blending all source powders at once, followed by calcination. The second involves the preferential creation of columbite as a precursor, by reacting NiO with Nb2O5 powder. Subsequently, PZNN-PZT powder can be prepared by mixing the columbite powder, PbO, and other components, followed by an additional calcination step. All the PZNNPZT powder samples in this study show a nearly-pure perovskite phase. High-density PZNN-PZT ceramics can be fabricated using powders prepared by a two-step calcination process, with the addition of 0.3 wt% MnO2 at even relatively low sintering temperatures from 800℃ to 1000℃. The grain size of the ceramics at sintering temperatures above 900℃ is increased to approximately 3 μm. The optimized PZNN-PZT piezoelectric ceramics show a piezoelectric constant (d33) of 360 pC/N, an electromechanical coupling factor (kp) of 0.61, and a quality factor (Qm) of 275.

수경재배 시스템에 있어서 배액의 재활용은 생산비 절감 및 환경오염 방지를 위하여 중요하다. 방울토마토를 반촉성 수경재배 하면서 생육 단계별 공급액, 배액 및 잎의 무기성분 분석을 통하여 순환식 수경재배 시스템 개발을 위한 기초자료를 확보하고자 본 연구를 수행하였다. 연구목적을 달성하기 위해 주기적으로 공급액, 배액 및 식물체 잎을 채취한 후 무기물 함량을 분석하였다. 생육 초기에는 배액의 EC가 공급액과 비슷한 약 2.0dS·m-1였지만, 생육 후기로 갈수록 높아져 9화방 착과기에는 4.5dS·m-1였다. 영양생장이 왕성한 생육 초기의 pH는 6.4~6.7 범위였으나 생식생장이 강해진 생육 후기에는 5.9~6.1로 낮아지는 경향이었다. 생육 초기에는 공 급액과 배액의 NO3-N, P, K, Ca 및 Mg 농도가 비슷하였지만 생육 후기로 갈수록 공급액보다 배액의 농도가 높아지는 경향이었다. 생육 초기에 잎의 T-N 함량이 높았지만 후기로 갈수록 낮아지는 경향이었다. K와 Ca 함량은 생육 초기에는 낮았으나 후기로 갈수록 높았으며, P와 Mg 함량은 생육초기부터 후기까지 유사한 수준으로 분석되었다. 이상의 결과는 토마토 수경재배를 배액재 활용에 있어 무기원소 농도 변화를 교정하기 위한 기초 자료로 활용될 수 있을 것이다.

In the expansion of odontogenic cyst, degradation of extracellular matrix and resorp디on of bone are accompa띠ed ， but its mechanism is under debate. The degrees of inflammation and fibrosis were graded in 39 cases of odontogenic cysts. Cytoplasrnic expressions in various cell types according to them were analyzed using immunohistochemis띠， for MMPs and πMPs. In epithelial cells, MMP-2 expression was increased with marked fibrosis(p=O.018) and in stromal cells, MMP-2,-9 and TIMP-2 expressions were slightly higher in cases with mild inflammation and marked fibrosis. Tendencies of positive correlation were found between MMP-2,-9 and TIMP-2 expressions in epithelial cells and between MMP-l and MMP-9 expressions in stromal cells. These results suggest that MMP-l ,-2 ,-9 and TIMP-2 expression might be related to the expansion of odontogenic cysts, and the expression rate of them was different according to cell types and the degree of inflammation and fibrosis.

MMPs are catalytic enzymes involved in the degradation of extracellular marix, and associated with invasive growth and metastasis of malignant tumors along with angiogenesis. This study was to evaluate the prognostic significance of VEGF expression and microvessel density(MVD) and the relationship between VEGF expression, MVD and MMPs expression in oral squamous cell carcinomas(OSCC). The materials were from 52 cases of OSCC during a period from 1991 to 2001. Clinicopathologic parameters such as clinical stage, recurrence, histologic grade and invasion pattern were evaluated. Immunohistochemical staining for MMP-2, MMP-9, VEGF and CD34 were performed and statistical analyses between clinicopathologic parameters and VEGF expression and MVD were done. MMP-2, MMP-9 and VEGF expressions were noted in 30(57.7%), 21(40.1%) and 38(73.1%) of 52 cases, respectively. MVD was measurable in 35 cases, and cases with increased MVD more than average were 16(45.7%) of 35 cases. There was no significant relationship between clinicopathologic parameters and VEGF expression or MVD in OSCC, which suggests that VEGF expression and MVD can not be regarded as reliable prognostic factors. Cases with less infiltrative growth pattern showed a tendency of increased MVD, which can explain the possibility that neovascularization might be an early event of tumor invasion. Lack of significant relationship between MMPs, VEGF expressions and MVD might be due to limited number of cases, and positive correlation between MMP-2 and VEGF expression suggests that both factors might be involved in the process of angiogenesis in OSCC.

The amount of genetic variability of a species is essential for its survival and adaptation in different environments, and studies of genetic diversity using molecular markers are necessary to understand the genetic structure of a population and to orientate effective strategies of germplasm conservation. The aim of current study was to determine the SSR markers that can be used rapidly and reliably to evaluated the pepper of Bulgaria landraces, and applied the markers to assement of introduce genetic diversity of the pepper germplasm. We used 22 polymorphic microsatellite markers to analysis of genetic diversity within 61 pepper collection of Bulgaria landraces germplasm, all SSR primers pairs produced 80 polymorphic and reproducible amplification fragments. An average value of polymorphic information contents (PIC) were 0.334 with a range of 0.061 to 0.63. The mean values of observed (HO) and expected heterozygosity (HE) were 0.383 and 0.154, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into three distinct groups, which was the landrace, moderate and wilde type, genetic distance (GD) value was 0.540. An average day of flowering time was 53 days with a range of 45 to 60 days. The everage od fruit length and width were 9.38cm with a range 2.1 to 23.6cm, and 3.51cm with a range 0.6 to 8.9cm, respectively. Molecular data were complemented with morphological measurements according to the descriptor list for the pepper collection of Bulgaria landraces germplasm.

2003년에 이상적으로 많이 발생하여 벼에 심각한 피해를 가져온 혹명나방의 재배방법별, 엽록소 함량별 피해실태를 조사하여 피해에 따른 수량반응, 미질변화 등을 구명하고자 조사한 결과는 다음과 같다. 1. 혹명나방의 피해가 심할수록 벼의 등숙비율, 천립중의 감소와 복백립 등 미숙립의 증가에 따른 완전미 비율이 감소되어 완전미 수량이 피해가 심한 곳에서 36% 감소되었다. 2. 혹명나방의 피해가 심할수록 쌀의 외관상 품위가 떨어질 뿐만 아니라 단백질함량이 높아져 식미치는 감소되어 미질이 급격히 저하되었다. 3. 질소질 비료의 시용량이 증가할수록 혹명나방에 의한 피해는 증가하였으며, 특히 주남벼의 경우 질소량이 증가할수록 피해가 급증하였다. 4. 질소 시비량이 추천 시비량인 11 kg/10a를 초과시 피해엽율이 60% 이상으로 급증하였고, 60% 이상 피해를 입은 엽의 비율도 25%이상으로 늘어나 수량 감수 요인으로 작용하였다.

A six-rowed naked barley cultivar, Donghanchal (Hordeum vulgare L.), with low-amylose, winter hardiness, viral disease resistance and good quality, was developed from the cross between the advanced line “Masangwamac/Kangbori*7” and Naehanssalbori in 1993.