• Journal of Information Processing Systems
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• 제16권2호
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• pp.435-446
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• 2020

With the ability to learn rules from training data, the machine learning model can classify unknown objects. At the same time, the dimension of hyperspectral data is usually large, which may cause an over-fitting problem. In this research, an identification methodology of tea diseases was proposed based on spectral reflectance and machine learning, including the feature selector based on the decision tree and the tea disease recognizer based on random forest. The proposed identification methodology was evaluated through experiments. The experimental results showed that the recall rate and the F1 score were significantly improved by the proposed methodology in the identification accuracy of tea disease, with average values of 15%, 7%, and 11%, respectively. Therefore, the proposed identification methodology could make relatively better feature selection and learn from high dimensional data so as to achieve the non-destructive and efficient identification of different tea diseases. This research provides a new idea for the feature selection of high dimensional data and the non-destructive identification of crop diseases.

• Integrative Medicine Research
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• 제3권1호
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• pp.4-10
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• 2014

Green tea and coffee consumption have been widely popular worldwide. These beverages contain caffeine to activate the central nervous system by adenosine receptor blockade, and due to the caffeine, addiction or tolerance may occur. In addition to this caffeine effect, green tea and coffee consumption have always been at the center of discussions about human health, disease, and longevity. In particular, green tea catechins are involved in many biological activities such as antioxidation and modulation of various cellular lipid and proteins. Thus, they are beneficial against degenerative diseases, including obesity, cancer, cardiovascular diseases, and various inflammatory diseases. Some reports also suggest that daily consumption of tea catechins may help in controlling type 2 diabetes. However, other studies have reported that chronic consumption of green tea may result in hepatic failure, neuronal damage, and exacerbation of diabetes, suggesting that interindividual variations in the green tea effect are large. This review will focus on the effect of green tea catechins extracted from the Camellia sinensis plant on type 2 diabetes and obesity, and the possible mechanistic explanation for the experimental results mainly from our laboratory. It is hoped that green tea can be consumed in a suitable manner as a supplement to prevent the development of type 2 diabetes and obesity.

• 한국식물병리학회지
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• 제11권4호
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• pp.383-385
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• 1995

Occurrence of white scab of tea (CAmellia sinensis) showing numerous, small, circular, reddish or yellowish brown spots on young tea leaves was observed at a tea plantation of Boseung, Chonnam, from May to June in 1992-1994. At the late growth stages, the center of the spot became light gray. The causal fungus of the white scab was identified as Sphaceloma theae Kurosawa. Symptoms were produced 5∼6 days after inoculation by the artificial inoculation of s. theae conidia, which was similar to those on naturally infected leaves.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.327-331
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• 2002

Tea is a pleasant, popular and safe beverage in the world. During the past decade, epidemiological studies have shown that tea catechins intake is associated with lower risk of cardiovascular disease. Tea provides a dietary source of health-promoting components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of tea-derived catchins has been extensively studied. The antioxidant effect is a synergistic action between catechins e.g. EGCG, EGC, ECG, EC, pheophytins a and b, and other components in tea leaves, which aye more bioavailable for human body. Green tea has a Higher content of catechins than other kinds of tea. Green tea extract with hot water has high potential and more efficiency to reduce cancer risk than any other tea products or pure EGCG. Protein, iyon, and other food components may interfere with the bioavailability of ten catechins. Interaction of catechins with drug affects the cancer-preventive activity of some cancer-fighting medication. Further studies are required to determine the bioavailability of tea catechins and cancer-preventive functionality.

• 한국식품과학회지
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• 제30권2호
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• pp.468-471
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• 1998

밤나무 잎을 이용하여 차(茶)로 제조한 다음, 제조된 차에서 항알레르기 효과를 실험하였다. 밤나무 잎 차는 대표적인 차의 형태인 불발효차와 반발효차의 제조공정을 이용하여 증제차와 유념차로 제조하였으며, 항알레르기 효과는 제조된 증제차와 유념차의 각각의 물추출물을 RBL-2H3 세포로부터 hexosaminidase의 방출 억제 정도를 측정하는 enzyme assay를 이용하여 실시한 결과, 물추출물의 $300\;{\mu}/mL$의 수준에서 증제차는 50.4%의 저해효과를 나타냈으며, 유념차는 35.4%의 저해효과를 나타내어 항알레르기 효과가 있음을 확인하였다.

• 셀메드
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• 제2권1호
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• pp.2.1-2.11
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• 2012

Tea polyphenols especially catechins have long been studied for their antioxidant and radical scavenging properties. Scientists throughout the world have investigated the usefulness of the regular green tea consumption in several disease conditions. In-vitro and in-vivo experiments on catechins especially epigallocatechingallate have revealed a significant role in many ways. Reactive oxygen species have been increasingly implicated in the pathogenesis of many diseases and important biological processes. Toxic effects of these oxidants, commonly referred to as oxidative stress, can cause cellular damage by oxidizing nucleic acids, proteins, and membrane lipids. Oxidative stress has been related to aging and age related disorders. It is found that in a wide variety of pathological processes, including cancer, atherosclerosis, neurological degeneration, Alzheimer's disease, ageing and autoimmune disorders, oxidative stress has its implications. Catechins have been reported to be useful in combating aging and age related disorders like cancer, cardiovascular disorders and neurodegenerative diseases. In this mini review we will discuss such studies done across the globe.

• 대한간호
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• 제6권4호통권30호
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• pp.31-35
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• 1967

• 디지털융복합연구
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• 제18권12호
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• pp.585-594
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• 2020

현재 노화와 관련된 퇴행성 근육 질환은 심각한 문제로 간주되고 있으나 근육 감소증의 치료 및 예방에 대한 약물 효과는 충분히 연구되지 않다. 이에 중국 전통차인 보이차의 추출물을 근육 감소증의 증상을 완화하기 위한 치료제로서 가치를 평가하고자 하였다. 본 실험에서는 이를 평가하기 위하여 ABTS 분석, MTS 분석, 면역 블롯 분석, 면역 형광 현미경법을 수행하였다. 보이차 추출물은 우수한 라디칼 소거 능을 나타냈으며, 또한 근관을 형성하는 Myh3의 발현이 촉진시켰고, 근관 형성을 증진시켰다. 따라서 보이차는 근육생성을 촉진하는 천연 물질이며 근감소증을 포함한 다양한 근육 질환의 예방 및 치료에 대한 제약 연구의 재료로 가치가 있음을 시사하며, 보이차의 구체적인 지표물질을 확인하고 이에 대한 추가연구가 필요할 것으로 보인다.

• 한국식물병리학회지
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• 제12권4호
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• pp.463-465
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• 1996

1992∼1994년 전남 보성지방 다원에서 2번차 수확 및 전지후의 차나무에 겹둥근무늬병의 발생이 관찰되었다. 잎에는 다갈색의 원형 내지 부정형의 병반 위에 겹둥근무늬가 형성되었고, 후기에는 병반 위에 겹둥근무늬의 소혹점(분생자층)이 다수 형성되었다. 이 병원균은 Pestalotiopsis longiseta (Spegazzini) Dai et Kobayashi로 분리, 동정되었고, 균 접종 11일 후에 병징이 관찰되기 시작하였다.