• Title/Summary/Keyword: Hot-Cold

Search Result 1,451, Processing Time 0.026 seconds

The effect of temperature changes on force level of superelastic nickel-titanium archwires (온도 변화가 교정용 니켈-티타늄 호선의 하중값에 미치는 영향)

  • Chun, Kyoung-Ae;Kim, Kwang-Won;Lim, Sung-Hoon
    • The korean journal of orthodontics
    • /
    • v.37 no.6
    • /
    • pp.432-439
    • /
    • 2007
  • The purpose of this study was to evaluate the influence of intraoral temperature changes on the orthodontic force level of a superelastic nickel-titanium alloy wire. Methods: Nickel-titanium archwires of $0.016"{\times}0.022"$ thickness were tested with a three point bending test setup, and temperature changes were applied. The force level changes according to temperature changes were measured at a 1.5 mm deflection during the loading phase and a 1.5 mm deflection during the unloading phase from a deflection to 3.1mm. Ten cycles of thermal cycling from baseline $(37^{\circ}C)$ to cold $(20^{\circ}C)$ or hot $(50^{\circ}C)$temperature were applied. Results: Alter thermal cycling, the force level during the loading phase decreased and the force level during the unloading phase increased even after the temperature was changed to the initial $37^{\circ}C$. Conclusions: The results suggest that the orthodontic force level can not return to the initial force level after temperature changes. When applying superelastic nickel-titanium archwires, we must consider that a lighter force than the loading force and a heavier force than the unloading force will be applied after intraoral temperature changes caused by eating and drinking.

Studies on Development of Functional Herbal Food Based on Yaksun - Focusing on the Relevant Chinese Literature - (약선(약선)을 이용한 건강 기능식 개발에 관한 연구 - 중국 문헌을 중심으로 -)

  • 박건태;김도완
    • Culinary science and hospitality research
    • /
    • v.9 no.4
    • /
    • pp.191-202
    • /
    • 2003
  • A growing interest in health has been leading to more interest in function of food rather than its taste and nutrition. Usually we think chemical-free or oriental food to be good for health. Yaksun is a food with herbal stuff, which reflects our desire for health and longevity and China's splendid food culture. It is based on the traditional medical thought of the Orient that both medicine and food have the same origin. Yaksun is a traditional functional or nourishing food with both nutritive and medicinal elements, which therefore provides such effects as epicurean pleasure, prevention of diseases and improvement of health. It is recorded that in China there was a dietitian in the royal court from the period of Seoju(B.C. 11∼7), who was responsible for supervising and controlling the health, nutrition and disease of an emperor. Therefore, herbal food has a very long history. Currently, there are many Yaksun stores in Japan and Taiwan as well as China, which are one of popular tourist destinations. Basically Yaksun follows the theory of the Oriental medicine. Yaksun is categorized into four(cold, cool, hot and warm) according to its temperature and into five basic tastes(bitter, sweet, pungent, salty and sour). Yaksun has the functions such as preventing diseases and aging improving internal organs, and healing diseases. In China many colleges of medicine have a department of Yaksun studies through which systematic researches have been being made since a long time ago. For Korea, the discipline of Yaksun studies is still at the beginning stage. To respond to a growing interest in health and prevent chronic adult diseases, it is required to develop a functional food by establishing a systematic theory of Yaksun and making more researches into it.

  • PDF

Development and performance evaluation of the porous tube dilutor for real-time measurements of fine particles from high humidity environments (고수분 환경에서 미세먼지 실시간 측정을 위한 다공 튜브형 희석장치의 개발 및 성능 평가)

  • Woo, Chang Gyu;Hong, Ki-Jung;Kim, Hak-Joon;Kim, Yong-Jin;Han, Bangwoo;An, Jeongeun;Kang, Su Ji;Chun, Sung-Nam
    • Particle and aerosol research
    • /
    • v.13 no.3
    • /
    • pp.105-110
    • /
    • 2017
  • Real-time measurements of fine particles from stack emission gases are necessary due to the needs of continuous environmental monitoring of PM10 and PM2.5. The porous tube dilutor using hot and cold dilutions was developed to measure fine particles without condensable particles from highly humid emission gases and compared to the commercialized ejector-type dilutor. Particle size distributions were measured at the emission gases from a diesel engine and a coal-fired boiler. The porous tube dilutor could successfully measure the accumulation mode particles including relatively large particles more than $3{\mu}m$ without nuclei particles, while the ejector dilutor detected some condensable particles and could not detect large particles. The porous tube dilutor could successfully remove the already condensed water droplet particles generated by a humidifier in a $30m^3$ chamber.

Effects of temperature on the growth and ingestion rates of the newly described mixotrophic dinoflagellate Yihiella yeosuensis and its two optimal prey species

  • Kang, Hee Chang;Jeong, Hae Jin;Lim, An Suk;Ok, Jin Hee;You, Ji Hyun;Park, Sang Ah;Lee, Sung Yeon;Eom, Se Hee
    • ALGAE
    • /
    • v.35 no.3
    • /
    • pp.263-275
    • /
    • 2020
  • Water temperature is known to affect the growth and feeding of marine dinoflagellates. Each dinoflagellate species grows well at a certain optimal temperature but dies at very cold and hot temperatures. Thus, changes in water temperatures driven by global warming and extremely high or low temperatures can affect the distribution of dinoflagellates. Yihiella yeosuensis is a mixotrophic dinoflagellate that can feed on only the cryptophyte Teleaulax amphioxeia and the chlorophyte Pyramimonas sp. Furthermore, it grows fast mixotrophically but rarely grows photosynthetically. We explored the direct and indirect effects of water temperature on the growth and ingestion rates of Y. yeosuensis feeding on T. amphioxeia and the growth rates of T. amphioxeia and Pyramimonas sp. under 7 different water temperatures (5-35℃). Both the autotrophic and mixotrophic growth rates of Y. yeosuensis on T. amphioxeia were significantly affected by temperature. Under the mixotrophic and autotrophic conditions, Y. yeosuensis survived at 10-25℃, but died at 5℃ and ≥30℃. The maximum mixotrophic growth rate of Y. yeosuensis on T. amphioxeia (1.16 d-1) was achieved at 25℃, whereas the maximum autotrophic growth rate (0.16 d-1) was achieved at 15℃. The maximum ingestion rate of Y. yeosuensis on T. amphioxeia (0.24 ng C predator-1 d-1) was achieved at 25℃. The cells of T. amphioxeia survived at 10-25℃, but died at 5 and ≥30℃. The cells of Pyramimonas sp. survived at 5-25℃, but died at 30℃. The maximum growth rate of T. amphioxeia (0.72 d-1) and Pyramimonas sp. (0.75 d-1) was achieved at 25℃. The abundance of Y. yeosuensis is expected to be high at 25℃, at which its two prey species have their highest growth rates, whereas Y. yeosuensis is expected to be rare or absent at 5℃ or ≥30℃ at which its two prey species do not survive or grow. Therefore, temperature can directly or indirectly affect the population dynamics and distribution of Y. yeosuensis.

A Study on the Preferences for Food Intake of Korean Industrial Workers (한국 근로자의 식품섭취 기호도에 관한 연구)

  • Kim, Chang-Sook;Ahn, Myung-Soo
    • Journal of the Korean Society of Food Culture
    • /
    • v.8 no.1
    • /
    • pp.1-9
    • /
    • 1993
  • This study was carried on the preferences for food intake pattern of Korean industrial workers. The survey was conducted from Feb 17, to March 31, 1992 by questionnaires which was composed of 21 items. The subjects of this study were composed of 426 clerical workers, and 439 physical workers. The results were obtained as follows. 1. In the educational background, clerical workers was almost of highschool or collage graduates, and physical workers was almost of highschool graduates. Marginal food cost of per person for lunch a day was from 500 Won to 1,000 Won. They replied that amount of staple food and side dishes were appropriate, and the type of preferable foods was Korean style cooked rice. Also it was known that physical workers thought their nutritive condition more badly than that of clerical workers. So the physical workers considered their health very much when they had meal. It was represented that unbalanced diet, without diet and drinking alcohol effected badly to food intake and taste of food was the most important point in food intake. 2. Preferences for staple foods; Cooked rice was preferred the most by the subjects. Cooked rice with redbean was preferred by clerical workers and cooked rice with soybean was preferred by physical workers and cooked rice with soybean was preferred by physical workers. Also clerical and physical workers liked Kalkooksoo (hot noodle), Nangmyun (cold noodle), bread, vegetable bread and disliked Sphagetti, Ramyun (Instant noodle) in same rate. In the next, cooked rice covered with raw fish pieces (Sushi) was preferred by clerical workers and Mandu-kook was preferred by physical workers. Also they disliked Curriedrice and Hashrice in same pattern. 3. Preference for side-dishes; The Acceptances for side-dishes were high soybean paste soup (clerical workers:43.7%, physical workers:34.4%), Kim chi stew, fried potatoes, crab steaming (37.8%, 36.9%), broiled fish (34.6%, 33.9%), fried green pepper, Ham, Chinese cabbage Kim chi, and pickled garlic by clerical and physical workers all together. But in clerical workers, Wooghugi beef-rib tang, Deodeok muchim, spinach namul, beef jangjeorim, fried shrimp were shown to have high preference in physical workers, beef-rib tang, wild onion and shepherd's purses muchim, soybean sprout, fish jeorim, fried sweet potatoes were high preference. 4. Preference of Snacks; The preferences for snacks were high in strawberry (clerical:36.3%, physical:34.3%), milk (49.9%, 44.4%), waxy rice Doek (30.7%, 30.2%), coffee (40.1%, 38.9%) by two groups in same order.

  • PDF

Comparative Analysis of the Bufonis Venenum by Using TLC, HPLC, and LC-MS for Different Extraction Methods

  • Lee, Hyo-Jae;Koung, Fan-Pei;Kwon, Ki-Rok;Kang, Dae-In;Cohen, Lorenzo;Yang, Pei-Ying;Yoo, Hwa-Seung
    • Journal of Pharmacopuncture
    • /
    • v.15 no.4
    • /
    • pp.52-65
    • /
    • 2012
  • Objectives: Toad venom, called Chan-Su, is a traditional Oriental medicine secreted from the auricular and the skin glands of the Bufo bufo gargarizanz Cantor or B. melanosticus Schneider and has been widely used in China, Korea and other parts of Asia for the treatment of pain, heart conditions, and cancer. We examined the concentrations of the main chemical constituents within a commercially available toad venom product and compared the levels for different extraction methods. Methods: Toad venom was extracted using either cold or hot water, ethanol (EtOH), methanol (MeOH), or ethyl acetate (EtOAc), was fractionated using precipitation or reflux, and was then analyzed using thin layer chromatography (TLC), high-performance liquid chromatography (HTLC), and liquid chroma-tography - mass spectrometry (LC-MS). Individual components were identified by comparisons of the retention times, the ultraviolet spectra, and mass spectras and differences in chemical constituents for different solvents and extraction methods are presented. Results: Components with authentic standards, including serotonin and bufodienolides (cinobufagen, bufalin, cinobufalin, and resibufogenin), were detected. The water extract of toad venom contained the greatest amount of serotonin ($75.7{\pm}0.1$ mg/g), but very small amounts of bufodienolides ($3.8{\pm}0.0$ mg/g). In contrast, the use of MeOH or EtOH extraction solutions resulted in 5-26 times higher concentrations of bufodienolides, with only trace amounts of serotonin. The relative and the absolute concentrations of the component also varied based on the extraction method; i.e., EtOH extracts yielded the greatest total amounts of bufodienolides, and EtOAc precipitation had the lowest amounts of bufodienolides. Conclusions: Toad venom consists of serotonin and several bufodienolides, and the choice of solvent to extract chemical the constituents is important as a way to enrich the purported active components for treating different conditions.

Micronucleus Test of DW-166HC, a Novel Radiopharmaceutic Anticancer Agent (신규 방사성 항암제 DW-166HC의 소핵시험)

  • Moon, Eun-Yi;Lee, Jin;Lee, Won-Yong;Choi, Chung-Ha;Lee, Dog-Keun;Ryu, Jei-Man;Chung, Yong-Ho;Yoon, Sung-June;ark, Kyung-Bae
    • Biomolecules & Therapeutics
    • /
    • v.5 no.3
    • /
    • pp.278-283
    • /
    • 1997
  • DW-166HC ($^{166}$ Holmium ($^{166}$ Ho)-Chitosan complex) is a new radiopharmaceutic anticancer agent with a broad anti-tumoriginec spectrum, especially against human fepatic cancer. DW-166HC was evaluated for the appearance of micronucleus in polychromatic erythrocytes (PCEs) of mouse bone marrow cells after subcutaneous and intravenous single administration. Bone marrow cells were prepared at 24 hr and 48 hr after DW-166HC-I ($^{165}$ Ho-Chitosan complex cold compound) administration and at 24 hr, 72 hr and 2 weeks after DW-166HC ($^{166}$ Ho-Chitosan complex : hot compound) administration. The results showed there was no statistically significant increase of the numbers of PCEs with micronucleus in all DW-166HC-I administered groups compared with a negative control group but there was statistically significant increase of the numbers of PCEs with micronucleus at 24 hr and 72 hr in all DW-166HC administered groups, which was recovered after 2 weeks from the drug administration. The results also showed the ratio of normochromatic erythrocytes (NCEs) to PCEs of all DW-166HC-I administered groups was not significantly different from that of a negative control group but there was significant difference this ratio at 24hr and 72 hr in all DW-166HC administered groups compared with that of negative group, which was also recovered after two weeks from the drug administration. These results suggested that DW-166HC-I may not cause any chromosomal damage but DW-166HC has in vivo mutagenic potential because of its radioactivity.

  • PDF

Current status and prospects of blueberry genomics research (블루베리 유전체 연구현황 및 전망)

  • Kim, Jin Gook;Yun, Hae Keun
    • Journal of Plant Biotechnology
    • /
    • v.42 no.4
    • /
    • pp.336-341
    • /
    • 2015
  • Blueberry (Vaccinium spp.) is a bush that grows well at special cultural environments such as acid soil, high organic matter content, and a good drainage and aeration compared to other general crops. Blueberries are well known to contain high amounts of anthocyanins and phenolic compounds, resulting in high antioxidant activity that provides health benefits, and expanding the cultivation areas and consumer's demand in the worldwide. However, the full genome of blueberry has not been announced until now. Furthermore, the genomic analysis and transcriptome approaches are not so popular compare to major crops such as orange, apple, and grape. The aim of the review about blueberry genomic research is to establish the platform for setting blueberry breeding target, increasing proficiency of blueberry research, and making the practical cultivation techniques in Korea. The main topics in the blueberry genomic research including transcriptome, genetic mapping, and various markers are related with cold hardiness, chilling requirement, hot tolerance, anthocyanin content, and flavonoid synthesis pathway on various tissues like flower bud, leaf bud, shoot, root, and berry fruit. The review of the current status of blueberry genomic research will provide basic information to the breeders and researchers and will contribute to development of blueberry industry with sustainable productions and increase of blueberry consumption as new profitable crops in Korea.

A Study of Oral Health Fact of High School Students in Certain District (일부지역 고등학생의 구강건강실태에 관한 조사연구)

  • Yoo, Jung-Sook;Park, Myung-Suk;Kim, Jung-Hee
    • The Journal of Korean Society for School & Community Health Education
    • /
    • v.8 no.2
    • /
    • pp.49-59
    • /
    • 2007
  • Objectives: This study was designed to understand the oral health fact of high school students, search for an education method and learning goal appropriate for the subjects, and utilize them as basic data to think of effective solutions for oral health care. Methods: The samples to achieve the purpose of this research are composed of 386 students in J industrial high school, OO city, Kyounggido, the number of male students 286, and female students 100. Data were statistically analyzed by frequency analysis, cross tabulation by using SPSS WIN Ver. 12.0. Results: First, The answers in terms of oral symptoms were in the order of 31.8% for gum hurt and bleeding, 31.4% for pain in teeth by drinking or eating hot and cold drinks or food, 27.1% for broken or cracked teeth, 25.7% for aching and throbbing teeth, 20.6% for unpleasant mouth smell, and 5.7% for pain of tongue and soft oral tissues. Second, In terms of behavior for oral health, 88.4% answered that they consume cariogenic snacks, while 29.2% of them, 2.5% of male and 6.3% of female enjoy consuming them but hardly brush their teeth after consumption. Third, In terms of timing for brushing teeth, the results show that 50.0% do so before breakfast, 47.9% after breakfast, 15.2% after lunch, 36.9% after dinner, 65.5% before going to sleep, and 3.5% after consuming snacks, whereas 64.2% answered that they are not aware of fluorine mouthwash. Fourth, In terms of oral health condition. proportion of children with one or more caries in permanent teeth was 71.0%, while 51.4% have $2{\sim}3$ cariogenic teeth, and 16.8% have more than 4 cariogenic teeth. Considering sex, female students have somewhat higher ratio showing 68.5% for male and 78.0% for female, but the ratio was 53.1% for male and 46.7% for female in case of $2{\sim}3$ cariogenic teeth, and 17.5% for male and 15.8% for female in case of more than 4 cariogenic teeth. 9.3% of students turned out to have decayed teeth. Fifth, In terms of oral hygiene condition, only 7.9% of them had excellent condition, and 38.4% need to improve. More specifically, 41.1% of male students and 30.6% of female students need to improve their oral hygiene condition. Conclusions: The study results suggest that School Dental health programs increase and need to be community-incorporated and comprehensive from elementary to high school.

  • PDF

Change of Inorganic Component, Reducing Sugar, Catalpol and Benzo[α]pyrene Contents of Rehmannia glutinosa Libosch. var. purpurea Makino by Drying Methods (지황의 건조 방법에 따른 무기성분, 환원당, Catalpol 및 Benzo[α]pyrene의 함량 변화)

  • Chang, Jun-Pok;Kil, Gi-Jung;Lee, Gun-Hee;Ji, Yoon-Sun;Kim, Bo-Ram;Kang, Ki-Hyun;Kim, Mee-Ree;Song, Mi-Ran;Park, Jong-Yoon;Doh, Eun-Soo
    • Korean Journal of Medicinal Crop Science
    • /
    • v.19 no.6
    • /
    • pp.501-507
    • /
    • 2011
  • This experiment was carried out in order to collect the basic data on the standardization of the manufacturing process of Rehmannia glutinosa Libosch. var. purpurea Makino drying. By the drying methods of R. glutinosa, the content of water, inorganic components, reducing sugar, catalpol and benzo[${\alpha}$]pyrene were investigated. The water content was 15.6~17.2% when R. glutinosa was dried by cold-warm air moisture absorption drying method (CAMAD) at $60^{\circ}C$ during 6 days. Among of the inorganic components of R. glutinosa the K content was the most followed by P, Na, Ca and Mg. The reducing sugar content of R. glutinosa by the hot air drying method (HAD) was much more than that by the CAMAD. The catalpol content of R. glutinosa was not different by the drying temperature when it was dried by the CAMAD. The catalpol content of the large size tuber (about 50.0 g/unit) showed a tendency to increase from $60^{\circ}C$ until $70^{\circ}C$ drying temperature, but that of the small size tuber(about 4.0 g/unit) was decreased as being a trend as the drying temperature high when R. glutinosa was dried by the HAD, But the catalpol content R. glutinosa had a tendency to drop significantly at drying temperature above $80^{\circ}C$. The benzo[${\alpha}$]pyrene content was little detected when R. glutinosa was dried by both the SLD and the CAMAD, and the sampling by the HAD indicated within the scope of 5 ${\mu}g/kg$ which was the scope to regulate by Korean food and drug administration. In conclusion, it seemed that an appropriate drying temperature of R. glutinosa by the CAMAD and the HAD was about $60^{\circ}C$ and about $70^{\circ}C$, respectively, when we consider the catalpol content and benzo[${\alpha}$]pyrene detection in the manufacturing process of drying R. glutinosa.