기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.

Frankliniella intonsa (Trybom) (Thysanoptera: Thripididae) is an important pest of field and greenhouse crops such as pepper and strawberry. Chemical attractants are commonly used for monitoring thrips, but few are available for F. intonsa. Thus, we evaluated three attractants of Frankliniella occidentalis known from literatures for their attraction of F. intonsa in Y-tube olfactometer. Fed unmated adult females of F. intonsa showed higher initial response to (S)-(−)-verbenone than other attractants, i.e. aggregation pheromone of F. occidentalis and methyl isonicotinate. Unfed mated adult females of F. intonsa showed similar initial response. These results suggest that (S)-(−)-verbenone also can be used for monitoring and further in behavioral control tactics of F. intonsa.

Negative effects of insecticides on non-target organism can be reduced by using selective and less toxic insecticides. We assessed the effect of subsequent application of flonicamid and Beauveria bassiana GHA on pests and natural enemies in soybean fields by recording their density in 6-8 d interval. Flonicamid controlled Aphis glycines Matsumura in 6 day after spray (DAS). Nymphs of Riptortus pedestris (F.) were also reduced by 46 and 48% in 12 and 19 DAS, respectively. Application of B. bassiana reduced R. pedestris nymph 50% in 16 DAS whereas adult R. pedestris, Medythia nigrobilineata Motschulsky and A. glycines were not significantly reduced in treated fields. Ladybird beetles, syrphid flies, hymenopteran wasps, and parasitism rate of R. pedestris eggs were not different between the treatment and control. These results suggest that flonicamid and B. bassiana showed less negative effect on the natural enemies and effective against aphids and nymphs stage of R. pedestris.

A powder injection molding process is developed and optimized for piezoelectric PAN-PZT ceramics. Torque rheometer experiments are conducted to determine the optimal solids loading, and the rheological property of the feedstock is evaluated using a capillary rheometer. Appropriate debinding conditions are chosen using a thermal gravity analyzer, and the debound specimens are sintered using sintering conditions determined in a preliminary investigation. Piezoelectric performance measures, including the piezoelectric charge constant and dielectric constant, are measured to verify the developed process. The average values of the measured piezoelectric charge constant and dielectric constant are 455 pC/N and 1904, respectively. Powder injection molded piezoelectric ceramics produced by the optimized process show adequate piezoelectric performance compared to press-sintered piezoelectric ceramics.

The purpose of this study was to comparatively analyze the active stability of shoulder joints according to the frequency of overhead motions, such as serving and spiking, engaged in by female professional volleyball athletes who play different positions, and to provide the results as the basic data for developing exercise programs to prevent shoulder joint injuries. The subjects of this study were 50 Korean female professional volleyball players and positions were as follows: left and right attackers, centers, setters, and liberos. The external rotation and internal rotation muscle strength and muscle strength ratios of the dominant and non-dominant arms of all subjects were measured using Biodex. The results of this study are as follows: Frist, no significant differences were found in the internal and external rotation muscle strength of the dominant and non-dominant arms between positions. Second, for the shoulder joint muscle strength ratio of the dominant arm, by position, the setter showed significantly greater stability compared to the other positions. Third, for the shoulder joint muscle strength ratio of the non-dominant arm, by position, no significant difference in stability between positions was found. Fourth, it was found that the dominant arm had significantly greater instability of the shoulder joint than the non-dominant arm for attackers and centers, but no significant difference was found for setters and liberos. This study comparatively analyzed the muscle strength ratios of the external/internal rotations and dominant/non-dominant arms, which can determine the stability of the shoulder joints between female professional volleyball playing positions that engage in jumps and spikes using only the dominant hand and positions that do not.

This study was conducted to develop economic injury level (EIL) and economic threshold (ET) of onion thrips, Thrips tabaci on welsh onion (Allium fistulosum L. var). The changes of welsh onion biomass and T. tabacci density were investigated after introductions of T. tabacci at different densities and days: By the results of the experiment in the early welsh onion cultivation periods (30d after transplanting), the biomass of welsh onion significantly decreased with increasing the initial inoculated density of T. tabacci. The relationship between cumulative insect days (CID) and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL and ET of T. tabacci on welsh onion were estimated at 24 and 20 CID per plant, respectively. By the results of the experiment in the late cultivation periods of welsh onion (about 120d after transplanting), the welsh onion biomass was also significantly different inoculation thrips densities to welsh onion. The EIL and ET were calculated as 35 and 28 thrips per welsh onion plant. Until a more elaborate EIL-model is developed, the present result may be useful for T. tabacci management during the cultivations of welsh onion.

This study was conducted to evaluate the effects of temperature and nematicides on endospore attachment characteristics of 2 Korean isolates of nematodeparasitic bacteria, Pasteuria penetrans. P. penetrans CJ-1 and 98-35 isolates and 3 species of root-knot nematodes in U. of Florida were used ; Meloidogyne incognita (MI), M. arenaria (MA), and M. javanica (MJ). Three nematicide levels of 2, 4, and 6 ppm were compared by treating Vydate and Nemacur in the endospore containing soils. The endospores were attached to the root-knot nematode juveniles by centrifugal method. Reproduction of the isolates was checked by observing root-knot nematode females harvested from inoculated tomato roots. 1. Among the two Korean isolates, 98-35 showed attachments to MI, MA, and MJ juveniles, but it could not reproduce in any species. CJ-1 reproduced on all the 3 tested root-knot nematode species. 2. Endospores pretreated in -14°C showed higher attachment rate than those pretreated in 4, 24, and 40℃. 3. Nemacur treatments significantly suppressed the attachment of the endospores to the juveniles, while Vydate treatment effects were negligible.

A storage mite (cheese mite), Tyrophagus putrescentiae, is known as the pest in storing grains and common health pest species in the dust around home. The mite directly affect our well-being as parasites, vectors of disease, and producers of allergens. But recently we found damages in horticultural crops especially in greenhouses. It is very difficult to diagnose the damage by the mite because of the tiny size of the mite. And the symptom is not clear at the beginning stage. In this study, observations were done on the mite and the crop damage symptoms in several horticultural crops under dissecting microscope and scanning electron microscope (SEM). The mite body size was 0.3~0.5㎜ and they had long hairs all around their body when observed under SEM. The characteristic damage symptoms in some horticultural crops are as follows. In phalaenopsis, the flower buds became yellow and the lower side of the leaves had white spots. The surface of young cucumber fruits became shiny and soft at the early damage stage. In the crops, the damaged surfaces became corky as the plants grew up. In peach tree, whole the trees lost vigor and flower drops were observed when the mite density was very high in greenhouse cultivation.

자외선은 피부 광노화의 주요 요인이며, 효과적인 자외선 차단제가 피부의 건강과 아름다움을 위해 필요하다. 본 연구는 세포 실험을 통하여 자외선에 의해 유도된 세포 사멸, 산화적 스트레스, matrix metalloproteinase 1 발현에 미치는 죽여추출물의 영향을 알아보고자 수행하였다. HaCaT 인간 각질세포를 여러 농도의 죽여추출물 유무 조건에서 자외선을 조사하고 세포의 생존율과 생화학적 과정들의 변화를 분석하였다. 죽여추출물은 자외선을 조사한 세포의 생존율을 증진시켰고, procaspase 3가 활성화 형태로 절단되고, Bax/Bcl-2 비율이 증가하는 세포 자살 과정을 완화시켰다. 죽여추출물은 자외선에 노출된 세포에서 활성산소의 발생과 지질 과산화도 감소시켰다. 또한 죽여추출물은 자외선에 의해 자극된 matrix metalloproteinase 1의 발현과 c-Jun N-terminal kinase의 인산화를 억제하였다. 본 연구는 죽여추출물이 자외선에 의한 세포 사멸, 산화적 스트레스, 그리고 matrix metalloproteinase 1 발현을 억제함을 보여 주었으며, 이 추출물이 피부 광노화의 일부 현상을 억제하는 화장품 원료로 유용함을 시사하였다.

Ganui-Dae, built in the reign of King Sejong, Joseon Dynasty, is a comprehensive observatory. It has various instruments for observation and time signal such as Ganui, Gyupyo(Gnomon), water-hammering type Honui and Honsang, and so on. Studying on Ganui-Dae has been focused on its location, history, criterion, etc, so far. However, studying on its external form and construction method has been conducted insufficiently. This study suggests the model for restoration of Ganui-Dae. The model is based on the analysis about external form of Ganui-Dae in various antique maps, and its construction method in those days.

Human embryonic stem cells (hESCs) are promising cell source because of their unique self-renewal and pluripotency. Although hESC-derived cardiac cells are currently generated worldwide, cryopreservation of these cells is still limited due to low rate of post-thaw survival. Cryopreservation of hESC-derived cardiac cells is critical in that their long-term storage can accelerate their use in regenerative medicine. However, to date, there are few reports on efficient cryopreservation and post-thaw survival of hESC-derived cardiac cells. In this study, we evaluated the effects of ginsenoside, which is known to improve survival of rat embryonic cardiomyocytes against myocardial ischemia injury in diabetic rats (Wu et al., 2011), on the survival of hESC-derived cardiac cells after thawing. We induced differentiation into cardiac cells using our previously reported method (Kim et al., 2011). Differentiated, pre-beating stage cardiac cells were cryopreserved using either mass cryopreservation or vitrification. To evaluate the effects of ginsenoside (Re, Rb), we compared three sets: pre- and post-thaw treatment, pre- or post-thaw treatment only. The survival of post-thaw cardiac cells were evaluated using Trypan-blue and Annexin V staining. In addition, the three groups were treated with ROCK inhibitor Y-27632, and compared with non-treatment groups. The effect of ginsenoside was significant in post-thaw treatment group, i.e, thawed cells expressed cardiac specific genes and showed specific functionality such as spontaneous beating. Taken together, we demonstrated favorable effects of ginsenoside on the survival of hESC-derived cardiac cells after cryopreservation and thawing. These results suggest a possible application of well-known cardioprotectant ginsenoside in cell-based tissue engineering using hESC-derived cardiac cells.