• 한국초등과학교육학회지:초등과학교육
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• 제24권2호
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• pp.130-137
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• 2005

Elementary preservice teachers' understanding about the insect molt and metamorphosis was examined. Data were collected through the paper-pencil test of 448 junior students at a National University of Education. The instrument used was developed by Son(2003) and modified for the test. The results are as follows: First, Only 3.1$\%$ of students had a scientific concept on the molt periods in the insect life cycle. Students had an alternative conception that molt occurs either only in the larval period (29.9$\%$) or only in the period from pupa to adult (22.3$\%$). The percentage of the students thinking that molt occurs in the period from larva to pupa was low. Second, 98$\%$ of students stated that molt has to do with the larval growth, but 39.1$\%$ of students had an alternative conception that molt occurs after the larval growth at each instar. 25.1$\%$ had a conception that molt is related with the larval growth, but did not show any further understanding. Third, most students understood the correct meaning of metamorphosis. 34..2$\%$ of students had an alternative conception that metamorphosis occurs only in the period changing from pupa to adult, and only a few thought that it occurs in the period from larva to pupa. 24.8$\%$ of students had a scientific concept on the periods in which metamorphosis occurs. Fourth, some students understood the hatching process as molt in the sense that the egg shell is taken off (21.0$\%$), and as metamorphosis in terms of the appearance change from egg to larva (25.0$\%$). Fifth, 35.5$\%$ of students selected bees as an insect of incomplete metamorphosis, and 35.3$\%$ responded 'I have no idea', showing that they had poor understanding about the insect life cycle.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1977-1981
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• 2012

Houttuynia cordata Thunb (HCT) is a native herb found in Southeast Asia which features various pharmacological activities against allergy, inflammation, viral and bacterial infection, and cancer. The aims of this study were to determine the cytotoxic effect of 6 fractions obtained from silica gel column chromatography of alcoholic HCT extract on human leukemic Molt-4 cells and demonstrate mechanisms of cell death. Six HCT fractions were cytotoxic to human lymphoblastic leukemic Molt-4 cells in a dose-dependent manner by MTT assay, fraction 4 exerting the greatest effects. Treatment with $IC_{50}$ of HCT fraction 4 significantly induced Molt-4 apoptosis detected by annexinV-FITC/propidium iodide for externalization of phosphatidylserine to the outer layer of cell membrane. The mitochondrial transmembrane potential was reduced in HCT fraction 4-treated Molt-4 cells. Moreover, decreased expression of Bcl-xl and increased levels of Smac/Diablo, Bax and GRP78 proteins were noted on immunoblotting. In conclusion, HCT fraction 4 induces Molt-4 apoptosis cell through an endoplasmic reticulum stress pathway.

• Journal of Animal Science and Technology
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• 제64권4호
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• pp.717-726
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• 2022

The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400 60-week-old Lohmann Brown layers were randomly divided into five groups (eight replicates of 10 birds for each group). Laying hens in the fasting control group received no diet from day 1 to day 10. The second group received a molt-inducing diet recommended by the breeding company. The third group received a wheat bran-based diet. The fourth group received a commercial layer diet with 8,000 ppm zinc (as zinc oxide, ZnO). The fifth group received an induced molting diet given to the second group with 8,000 ppm zinc, respectively. Egg production in the fasting control group and groups fed a diet with ZnO were significantly lower (p < 0.001) than those in groups fed the molt-inducing and wheat bran-based diets without ZnO during molting. Egg laying in the fasting control group was rapidly reduced and stopped on the 5.9th day of molting. In both groups having molt treatment with ZnO, egg production was similarly reduced and ceased on the 6.9th day and 7.0th day of molting, respectively, none of them differed significantly from the control. Layers fed molt-inducing diet or wheat bran-based diet did not reach the cessation of laying even on the 28th d of molting period. Relative weights of the ovary and growing oocytes of layers subjected to fasting or fed diets with ZnO were significantly lower than those of other groups. During the first two weeks of post molting, layers fed molt-inducing diet with ZnO showed higher egg production than the other two groups (p < 0.01). The eggshell strength in the group fed the commercial diet with ZnO was significantly higher than those fed the molt-inducing diet or wheat bran-based diets at 6 weeks of post molting (p < 0.05). These results suggest that the non-feed withdrawal molting using ZnO is more effective in inducing molting and increasing post-molt egg production and egg quality than other methods using a molt-inducing diet alone or wheat bran-based diet without ZnO.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3073-3076
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• 2012

Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.317-318
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• 2001

In crustacea the molting cycle is the most important physiological process affecting growth, behaviour, reproduction and population dynamics through their life span. Particularly molt cycle is closely related to reproductive cycle, and it is important to determine the successive stages of molt cycle to understand reproductive phenomena including ovarian cycle and the development of the embryos in the marsupium. (omitted)

• Fisheries and Aquatic Sciences
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• 제5권4호
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• pp.271-280
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• 2002

Ovarian cycle, marsupial development and molt cycle of Archaeomysis kokuboi were studied to understand these processes as a whole event. Based on morphological characters the marsupial development is divided into 3 stages, Embryonic stage (duration time of 4 days), Nauplioid stage (5 days) and Postnauplioid stage (4 days). Morphological description was ma de for the 3 stages, and each stage was examined in relation to the corresponding stages of ovarian cycle and molt cycle.

• 한국수산과학회지
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• 제34권1호
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• pp.38-42
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• 2001

Metapenaeopsis dalei의 탈피과정 및 기작을 구명하기 위하여 1999년 3월부터 5월 사이에 통영 용초도 주변 해역에서 채집된 자 각장 $13{\pm}2mm$의 개체를 사용하였다. 강모의 발달과 탈피단계는 미지 부분을 절개, 현미경으로 관찰하여 그 미세구조를 바탕으로 판정하였다. M. dalei의 주 탈피단계는 5개 (Stage A, B, C, D와E)로 나눌 수 있었다. Stage B에서는 setal cone의 생성을 확인할 수 있었으며, Stage $D_1'$에서는 setal shafts을 관찰할 수 있었다. 탈피단계 (Stage E)는 매우 빠르게 진행되어, 1분을 초과하지 않았다.

• 대한한의학회지
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• 제22권1호
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• pp.53-62
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• 2001

Objective : The aim of this study was to evaluate the efficacy of Injinchunggan-tang on Hepatitis C virus infection, and to clarify the mechanism of treatment by indentifying the effect of Injinchunggan-tang on cytokine secretion. Methods : In vitro model of HCV infection in MOLT 4 cell was used. The effect of Injinchunggan-tang on the attachment of HCV on MOLT 4 cell was studied by PCR method. The change of cytokine secretion according to Injinchunggan-tang treatment was investigated by ELISA. Results : Injinchunggan-tang inhibited the attachment of HCV on MOLT 4 in the concentration of $10-2{\mu\textrm{g}}/\mu\textrm{\ell}$ and $10-1{\mu\textrm{g}}/\mu\textrm{\ell}$. In cytokine assay, Injinchunggan-tang increased the secretion of IL-4 of mouse splenocytes and PBMC in 48 hour culture as well as the secretion of IL-12 of mouse splenocytes and PBMC in 48 hour culture, whereas it decreased the secretion of $IFN-{\gamma}$ of mouse splenocytes in 24 and 48 hour culture. Conclusion : The results of this study show that Injinchunggan-tang has an inhibitory effect on the attachment on HCV on Mo1t4 Cell, and that it increases the secretion of IL-4 and IL-12 of mouse splenocyte and PBMC.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1196-1200
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• 2008

An experiment was conducted to evaluate the physiological changes of laying hens subjected to feed removal during induced molting while received probiotics in the drinking water. Post-molt performance and egg quality criteria were also studied. Ninety 78-week-old Hy-line W36 laying hens were divided into two treatment groups according to equal body weight and subjected to induced molting by continuous feed removal until around 30% BW reduction. The experiment lasted 12 wks consisting of 4-wk molting and 8-wk post-molt periods. Treatment 1 received no probiotics and was considered as the control. Treatment 2 was similar to the control except that hens received probiotics in the drinking water at 400 mg/L during feed deprivation. The results indicated that hens in both groups went out of production by Day 5. However, hens received probiotics reached 5 and 50% egg production sooner than the control (30 and 52 days vs. 31 and 54 days). Starvation during molting increased heterophil to lymphocyte (H/L) ratio, hematocrit and plasma T4 and $Na^+$ levels while plasma T3 and Cl- levels were decreased. Probiotics had no significant impact on BW reduction during molt. Post-molt egg production and egg mass were higher in hens which previously received probiotics, but these responses were not significant. However, feed conversion ratio was significantly better in hens which received probiotics. Hematocrit, plasma thyroid hormone concentrations (T3 and T4) and plasma $Na^+$, $K^+$ and Cl- levels during molting were not significantly influenced by supplementation of probiotics. However, H/L ratio showed a significant (p<0.05) reduction in birds which received probiotics suggesting beneficial effects of this product for feed-deprived laying hens. No significant difference was observed in post-molt egg quality criteria.

• Applied Microscopy
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• 제38권2호
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• pp.97-105
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• 2008

탈피에 따른 거미 과립혈구의 미세구조 변화를 고배율의 투과 전자현미경으로 관찰하였다. 산왕거미(Araneus ventricosus)의 과립혈구는 산호성 과립혈구(EGs)와 염기호성 과립혈구(BGs), 그리고 혈색소혈구 (cyanocytes) 등 세 종류가 구분되었다. EGs와 BGs는 공통적으로 전자밀도가 높은 구형 과립을 함유하고 있었지만, 과립의 크기와 미세구조의 차이에 따라 두 종류가 확연히 구분되었다. 과립의 크기가 작은 EGs는 탈피기간중 세포소기관의 다양한 형태적 변화가 나타나며, 왕성한 식작용을 통해 많은 식포를 형성하는 것으로 관찰되었다. 반면, 과립의 크기가 큰 BGs의 세포질에서는 식포가 관찰되지 않았으나, 탈피시기 동안 과립의 전자밀도가 낮아지는 특성이 관찰되었다. 가장 대형의 과립혈구인 혈색소세포의 세포질에는 많은 헤모시아닌 결정체가 동심원상으로 배열되어 있었으며, 탈피기간중 혈구의 일부는 불규칙한 구조로 변형되었다. 고배율의 투과전자현미경으로 헤모시아닌 결정체의 격자구조를 관찰한 결과, 미세소관(microtubule)과 매우 유사한 구조를 가지고 있었으며, 각각의 미세한 관상 구조는 다시 약 20여 가닥의 극히 미세한 필라멘트로 이루어져 있음이 확인되었다.