• 제목/요약/키워드: BOO

검색결과 3,901건 처리시간 0.037초

Digital Breast Tomosynthesis versus MRI as an Adjunct to Full-Field Digital Mammography for Preoperative Evaluation of Breast Cancer according to Mammographic Density

  • Haejung Kim;So Yeon Yang;Joong Hyun Ahn;Eun Young Ko;Eun Sook Ko;Boo-Kyung Han;Ji Soo Choi
    • Korean Journal of Radiology
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    • 제23권11호
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    • pp.1031-1043
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    • 2022
  • Objective: To compare digital breast tomosynthesis (DBT) and MRI as an adjunct to full-field digital mammography (FFDM) for the preoperative evaluation of women with breast cancer based on mammographic density. Materials and Methods: This retrospective study enrolled 280 patients with breast cancer who had undergone FFDM, DBT, and MRI for preoperative local tumor staging. Three radiologists independently sought the index cancer and additional ipsilateral and contralateral breast cancers using either FFDM alone, DBT plus FFDM, or MRI plus FFDM. Diagnostic performances across the three radiologists were compared among the reading modes in all patients and subgroups with dense (n = 186) and non-dense breasts (n = 94) according to mammographic density. Results: Of 280 patients, 46 (16.4%) had 48 additional (39 ipsilateral and nine contralateral) cancers in addition to the index cancer. For index cancers, both DBT plus FFDM and MRI plus FFDM showed sensitivities of 100% in the non-dense group. In the dense group, DBT plus FFDM showed lower sensitivity than that of MRI plus FFDM (94.6% vs. 99.6%, p < 0.001). For additional ipsilateral cancers, DBT plus FFDM showed specificity and positive predictive value (PPV) of 100% in the non-dense group, but sensitivity and negative predictive value (NPV) were not statistically different from those of MRI plus FFDM (p > 0.05). In the dense group, DBT plus FFDM showed higher specificity (98.2% vs. 94.1%, p = 0.005) and PPV (83.1% vs. 65.4%; p = 0.036) than those of MRI plus FFDM, but lower sensitivity (59.9% vs. 75.3%; p = 0.049). For contralateral cancers, DBT plus FFDM showed higher specificity than that of MRI plus FFDM (99.0% vs. 96.7%, p = 0.014), however, the other values did not differ (all p > 0.05) in the dense group. Conclusion: DBT plus FFDM showed an overall higher specificity than that of MRI plus FFDM regardless of breast density, perhaps without substantial loss in sensitivity and NPV in the diagnosis of additional cancers. Thus, DBT may have the potential to be used as a preoperative breast cancer staging tool.

모바일 간편결제 서비스 이용 시 생체인증 사용의도에 관한 연구: 경험자와 비경험자 비교를 중심으로 (A Study on the Intention to Use Biometric Authentication When Using Mobile Easy Payment Service: Focusing on the Comparison of Experienced and Non-Experienced Persons)

  • 주재승;이원부
    • 경영정보학연구
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    • 제23권4호
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    • pp.1-22
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    • 2021
  • 코로나19로 인한 언택트 환경 속에서 모바일 간편결제가 확산하고 있다. 모바일 결제 시 본인 인증을 위해 다양한 수단이 사용되고 있으며, 최근 생체정보의 활용이 증대되고 있다. 본 연구에서는 생체정보 사용에 영향을 주는 여러 가지 요인과 사용의도에 대한 상관 분석을 하였다. 요인별 변수를 성과기대, 노력기대, 사회적 영향 및 보안성으로 구분하고, 사용의도와의 연관성 파악을 위해 통합기술수용이론을 기반으로 실증분석을 하였다. 이를 위해 변수들을 단계적으로 투입하는 단계적 회귀분석을 총 4회 실시하였다. 분석결과, 통합기술수용이론에서 제시된 성과기대, 노력기대, 사회적 영향, 보안성 등이 모두 사용의도에 긍정적인 영향을 미치고 있으며, 또한 노력기대와 보안성은 생체인증 경험여부에 따라 사용의도에 조절효과가 있는 것으로 제시되었다. 이 연구를 통해 생체정보의 효과적 활용과 기술 발전에 도움이 되기를 기대한다.

선불 전자지급 수단의 온라인 충전 이용의도에 관한 연구: 교통카드사용자, 조절효과를 중심으로 (A Study on the Use Intention of Online Charging Service for Prepaid Electronic Payment: Focused on the Moderating Effects and Transportation Card Users)

  • 이선구;이원부
    • 경영정보학연구
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    • 제23권3호
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    • pp.177-200
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    • 2021
  • 최근 전자지갑, 디지털화폐, 선불포인트, 선불카드 같은 선불전자지급수단의 사용이 점차 증가하고 있다. 선불지급수단은 선 충전, 후 사용이라는 특성이 있다. 본 연구는 선불 충전이 필요한 서비스의 개선에 도움을 주고자, 선불전자지급수단의 온라인 충전 이용의도에 영향을 미치는 요인들에 대하여 기술수용모델을 변형하여 실증적으로 연구하였다. 선불전자지급수단의 온라인 충전 이용의도에 관련된 선행연구가 많지 않아 기존 간편결제와 전자화폐에 대한 연구들을 통해 요인 변수를 도출하였다. 선불 교통카드 사용자를 대상으로 조절효과를 중심으로 온라인 충전의 이용의도를 분석하였다. 연구 결과 독립변수 중에서 '편리성', '보편성', '자기효능감'은 매개변수인 '지각된 유용성'에 정(+)의 영향을 미치는 것으로 나타났다. '지각된 유용성'은 종속변수인 '이용의도'에 유의한 영향을 미치는 것으로 분석되었다. 사용자들의 성별, 인터넷 사용시간, 인터넷 쇼핑 구매빈도, 모바일충전 이용빈도, 교통카드 이용형태 등에 따라서 '지각된 유용성'과 '이용의도'에 조절효과가 유의미하게 나타났다. 시사점으로 선불 서비스의 유용성을 높이는 방향으로 서비스에 대한 개선과 차별화된 마케팅의 필요성을 제안하였다. 다른 요인변수와 조절변수를 추가하여 전자지갑, 간편결제포인트, 디지털화폐 등의 서비스를 대상으로 향후 연구 방향을 제시하였다.

구창의 문헌연구 (A literal study on the Gu-Chang)

  • 정한솔;박종훈;육상원;이광규
    • 동의생리병리학회지
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    • 제16권1호
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    • pp.32-44
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    • 2002
  • Gu-Chang is a disorder characterized by recurring ulcers confined to the oral mucosa. Despite much clinical and research attention, the causes remain poorly understood. In this paper, we will compare Gu-Chang with Recurrent Aphthous Stomatitis(RAS) in order to know what is the similiarity between Gu-Chang and RAS. So we will arrange various oriental and western medical literatures which are important. As a result of arrangement of the causes, symptoms and therapys of Gu-Chang, we can conclude through the studies as follows. 1. The etiologies of Gu-chang are following. In the Sthenia syndrome, there are evil heat of external factor, heat of heart and spleen, insomnia, heat of upper warmer, stress and diet, heat of lung and heart, excessive heat of upper warmer, inappropriate food intake, heat conveyance of organ, heat of stomach merdian, moistured heat of spleen and stomach and stasis of liver energy. In the Asthenia syndrome, there are deficiency of stomach energy, deficiency of upper warmer leading to heat, deficiency of middle warmer leading to cold, deficiency of lower warmer leading to heat, deficiency of middle energy, deficiency of blood, decreased fire and deficiency of soil, yin fire of lower warmer, deficiency of heart yin, deficiency of spleen yin and deficiency of qi and blood. 2. In western medicine the causes of RAS is presumed as local, microbial, systemic, nutritional, genetic, immunologic factors. 3. Once Gu-chang is compared with RAS, in the deficiency of yin leading to hyperactivity of fire, deficiency of yin leading to floating of fire and stasis of liver energy, recurring of Gu-chang is similar to RAS. Although recurring of Gu-chang due to tripple warmer of excessive fire has no recurrance, since there are the degree of Pain, site of lesion, dysphagia etc, it is similar to major RAS. It is may be believed that Sthenia Gu-chang is similar to major RAS, shape of recurring, site of lesion, degrree of Pain and white color of Asthenia Gu-chang are similar to minor RAS, but there is no similarity concerning herpes RAS in the literatures that describe the symptoms. 4. Generally, the treatment of Gu-chang is divided into Asthenia and Sthenia Syndrome. The method of cure to Sthenia syndrome is heat cleaning and purge fire, Asthenia syndrome is nourish yin to lower and adverse rising energy and strength the middle warmer and benefit vital energy. 5. Following is the medication for Sthenia syndrome. Heat of heart and spleen is Do Jok San, Yang Gyek San, Juk Yup Suk Go Tang, evil heat of external factor is Yang Gyek San Ga Gam, Stasis of liver energy is Chong Wi Fae Dok Yum, moistured heat of spleen and stomach is Chong Gi Sam Syep Tang. The medication for Asthenia Syndrome is following. Deficiency of upper warmer leading to heat is Bo Jung Ik Gi Tang, deficiency of middle warmer leading to cold is Bu Ja Lee Jung Tang, deficiency of lower warmer leading to heat is Yuk Mi Ji Hwang Tang, deficiency of yin leading to hyperactivity of fire is Ji Baek Ji Hwang Hwan, deficiency of yin leading to floating of fire is Lee Jung Tang Ga Bu Ja Medicine for external use were Yang Suk San, Boo Wyen San, Rok Po San, Yoo Hwa San ate. 6. In western medicine, there is no specific treatment for RAS, and management strategies depend on dinical presentation and symptoms and includes antibiotics, oral rinses, glucocorticoids, immunomodulatory drugs, vitamines, analgesics, laser and antiviral agents.

동의보감(東醫寶鑑)을 통한 허준의 의학사상에 관한 고찰 (A study on Huh-Joon's medical thoughts in Dong-Eui-Bo-Kham)

  • 권학철;박찬국
    • 대한한의학원전학회지
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    • 제6권
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    • pp.89-130
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    • 1993
  • Huh-joon's medical thoughts shown on his medical book of the Doog-Eui-Bo-Kham can be summerized as follows. 1. The general trend of medical science in Koryo dynasty is that much more interests were concentrated upon the books about curative means rather than upon the books about theoretical knowledge of medical science. With the development of Hyang Yak(鄕樂) (the term referring either various kinds of domestic medical stuffs such as herbs or the curative methods using those stuffs) and the writing of books on Hyang Yak, independent medical science of the nation's own was established in late Koryo dynasty. And the national medical science was continuously further developed until early Choson dynasty. Briskly-expanded mutual exchanges with China in early Choson dynasty provided Choson opportunities to import Chinese medical science and to examine it. Under this circumstances, he wrote the Dong-Eui-Bo-Kham. 2. As we look over the preface and Chip-Rae-Muo(集例文), we can find the characterstic of Doog-Eui-Bo-Kham is that the philosophical theory of Taoism was quoted in explaining the principles of his medical science and that the main idea of Naekyuog is the basis in explaining the way of curing diseases. 3. 83 kinds of medical books were quoted in the Doog-Eui-Bo-Kham. Besides, as many as 200 kinds of books including Tao-tzu's teaching books(道書), history books(史書), almanac(曆書), and Confucius' teaching books(儒家書籍) were quoted in total. Naekyuog and Eue-Hak-Ip-Mun, Dan-Kye-Sim-Bup were the most frequently quoted books among them. 4. Huh-Joon's medical thoughts about health care were like these. 1) The reason why Huh-Joon regarded the idea of health care as of great importance was that he laid much more emphasises on the preventive medicines rather than on the remedial medicines. The direct reason was that he was greatly influenced by profound knowledge of Taoist's study of discipline and who participated in the editing the books from the beginning. 2) Huh-Joon's outlook on human body started from the theory of "Unity of Heaven and Man"(天人合一論), which implied man was a kind of miniature universe. In addition to that, he largely theory of essence(精), vital force(氣), and spirit(神) which were regarded very important as the three most valuable properties in Taoism. However, he took his medical ground on practical and pragmatic idea that he did not discuss fundamental essence(元精), fundamental vital force(元氣), and fundamental spirit(元神) which were given by Heaven from the received only the theory of essence, vital force, and spirit which were acquired after birth and worked mainly on realistic activity of life. 3) Huh-loon accepted Do-In-Bup(導引法) sharply as a method to prevent and cure diseases. 5. Huh-loon's medical thoughts on remedial aspects are as 1) Naekyung was considered so important in Dong-Eui-Bo-Kham that not only each paragraph was begun with the Quotations from Nackyung but also the edited order of the content of the book the same with that of Naekyung. And differently from the former korean medical books he accepted at large and recorded the theories of the four noted physicians of the Geum-Won era(金元四大家) by Dong-Eui-Bo-Kham. 2) For the first time, Huh-Joon introduced the theory of Un-Ki (運氣論) in the Dong-Eui-Bo-Kahm. However, he accepted it as a pathological function of human body but he did not apply physical constitution, physiological function, pathological function, and remedial methods. 3) Huh-loon liked to use Hyang Yak that he recorded korean name of Hyang Yak(鄕名), places of the production(産地), the time of collecting(採取時月), and the way of drying herbs(陰陽乾正法) in the remedial method of a single medicine prescription for diseases at the end of each paragraph. By doing so, he developed, arranged, and revived Hyang Yak. 4) He believed that since the natural features of China were different from those of Korea the reasons of being attacked with its remedial methods couldn't be the same with different from Chinese medical books which primarily focused on paralysis and the injury of the cold has his own structure in his book that he founded independent science of this nation. He consulted enormous documents He discovered and wrote the theory and therefore concrete methods for diseases so that the book hadthe principles of outbreak of diseases(理), methods of cure(法), prescription(方), and a single medicine prescription(藥) and set system of medical science in a good order. By doing so, he and pragmatic development of medical science.

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${\ll}$방약합편(方藥合編)${\gg}$에 대한 연구 (A Study on Bang-Yak-Hap-Py$\breve{u}$n)

  • 김형태;윤창열
    • 대한한의학원전학회지
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    • 제5권
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    • pp.151-199
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    • 1992
  • A study on Bang-Yak-Hap-Py$\breve{u}$n, one of the most widely-known Korean medicine books, has been conducted and the findings are as follows:the political and social background at the end of Yi-dynasty amidst the inflow of western civilization and the aggression of foreign forces can be seen as a historical period of trial, when civilization and independence had to be preserved at the same time, during the period, the social trend was to pursue a rapid practical solution rather than a profound theory. Responding to this trend, simple and easy medical science became to prevailand the representative medicine book of this kind was Bang-Yak-Hap-Py$\breve{u}$n. 1. Bang-Yak-Hap-Py$\breve{u}$n was written comprising the characteristics of simple and easy medical science with a view to popularizing-collection of logics, easy readability, medical science in time, etc. 2. Bang Yak-Hap-Py$\breve{u}$n, rich and grand in content, came out of Dong-$\breve{U}$i-Bo-Gam at the right moment as a pragmatic guide book of Korea medical practice symbolizing Korean spirit. 3. Do-yun Whang whose pen name was Hye-Am was born in Changwon, Kyungnam-do as the 18th descendant of Changwon Whang family. He engaged in medical practice in Seoul and wrote and edited Boo-Bang-Py$\breve{u}$n-Ram. $\breve{U}$i-Jong-Son-Ik, $\breve{U}$i-J$\breve{u}$ng-Son-Ik-Bu-Yeo, $\breve{U}$i-Bang-Whan-Tu, ect. and made his son, Pil-Su follow him and let him edit Bang-Yak-Hap-Py$\breve{u}$n, which put $\breve{U}$i-Bang-Whal-Tu and Son-Ik-Bon-Cho together. 4. The construct of Bang-Yak-Hap-Py$\breve{u}$n can be subdivied into three parts: herbs of 34 classes and 514 kinds were arranged on the upper part and $\breve{U}$i-Bang-Whal-Tu was arranged on the middle end lower part. Such arrangement can be very effective in clinics. 5. Bang-Yak-Hap-Py$\breve{u}$n as a curative book of Korean medical science has been a necessary another ego for many Korean medical practioners. It also played a great role of enhancing Korean oriental medical science to be widely used by Koreans. On the other hand, it produced a side effect of emergence of employed medical practioner who lacked in scholastic aptitude. 6. Tens or newly edited Bang-Yak-Hap-Py$\breve{u}$n have been issued. Among them, Jung-Jeong, Bang-Yak-Hap-py$\breve{u}$n, J$\breve{u}$ng-Mak-Bang-Yak-Hap-Py$\breve{u}$n. By$\breve{u}$n-J$\breve{u}$ng-Bang-Yak-Hap-Py$\breve{u}$n, and By$\breve{u}$n-J$\breve{u}$ng-Bang-Yak-Jung-Jeon have been widely known. Lately, Bang-Yak-Hap-Py$\breve{u}$n which includes more symptoms and remedies or is translated into Korean came out in several kinds. 7. The number of korea classical medicinal books quoted in Bang-Yak-Hap-Py$\breve{u}$n is 68, among which Dong-$\breve{U}$i-Bo-Gam Occupies the top in the list enlisting 69 medicinal treatment. This Shows that Dong-$\breve{U}$i-Bo-Gam gave birth to Bang-Yak-Hap-Py$\breve{u}$n.

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Effects of Endocrine Disruptors (NP, DBP and BPA) on Sperm Characteristics and Development of IVF Embryos in Pig

  • Yuh, In Suh;Cheong, Hee Tae;Kim, Jong Taek;Park, In Chul;Park, Choon Keun;Yang, Boo Keun
    • Journal of Animal Science and Technology
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    • 제55권4호
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    • pp.237-247
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    • 2013
  • This study was to examine single or combined in vitro effects of environmental endocrine disruptors on boar sperm characteristics, oxidative stress damage in sperm and development of porcine IVF embryos. Addition of various concentration of NP (10, 20, $30{\mu}M$), DBP (10, 50, $100{\mu}M$) and BPA (1, 5 or $10{\mu}g/ml$) on boar sperm characteristics such as percentages of sperm motility, viability, membrane integrity and mitochondrial activity were dose-dependently decreased within 3, 6 or 9 hr incubation period (p<0.05). The overall detrimental effects increased with incubation time increasement. NP, DBP and BPA showed the detrimental effects on sperm membrane and mitochondria of energy production organelles affecting cell viability with the dependancy of dose and incubation time. In combination effects, NP ($10{\mu}M$) + DBP ($10{\mu}M$) significantly decreased boar general sperm characteristics for 3 or 6 hr incubation period compared with control (p<0.05). When both of NP and DBP concentrations (NP; $30{\mu}M$, DBP; $100{\mu}M$) increase, the detrimental effects on sperm characteristics were larger than those of low concentration combination (p<0.05). The inhibitory effects of NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$) on sperm characteristics were larger than those of NP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) (p<0.05). DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) decreased sperm characteristics compared with the low concentration combination (DBP $10{\mu}M$ + BPA $1{\mu}g/ml$, p<0.05). This result indicates the detrimental effects of both chemicals on sperm characteristics were dose dependent. Addition of NP ($30{\mu}M$) + DBP ($100{\mu}M$), NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$), DBP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) or DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) significantly increased lipid peroxidation for 3 or 6 hr incubation period (p<0.05) compared with no addition control. NP (${\geq}20{\mu}M$) decreased the percentages of IVF embryo development from morulae and blastocyst stages (p<0.05) and its detrimental effects were dose-dependant. BPA 0, 1, 5 or $10{\mu}g/ml$ decreased significantly and dose-dependently the percentage of morulae plus and blastocysts (p<0.05). Combinations of DBP ($100{\mu}M$) plus NP ($30{\mu}M$) and DBP ($100{\mu}M$) plus BPA ($10{\mu}g/ml$) did not affect on morulae and blastocyst development, but NP ($30{\mu}M$) plus BPA ($10{\mu}g/ml$) has significant detrimental effect on embryo development at these stages (p<0.05). These overall results indicate that the partial detrimental effects on boar sperm characteristics and embryo development by NP, DBP, BPA or the combination of these chemicals might be due to the increasement of lipid peroxidation and free radical formation in the cell and there were no specific interaction effects on boar sperm and embryo degeneration among the combined treatments.

시설재배 아스파라거스 중 살충제 acetamiprid의 잔류특성 (Residual Characteristics of Insecticide Acetamiprid in Asparagus under Greenhouse Condition)

  • 김지원;이정민;이도승;강승태;김대운;이동선;류기중;부경환
    • 농약과학회지
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    • 제19권3호
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    • pp.204-209
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    • 2015
  • 본 연구는 시설재배 아스파라거스를 대상으로 acetamiprid 입상수화제의 잔류특성을 규명하고 그에 따른 안전사용기준 설정의 기초자료를 확보하고자 수행하였다. Acetamiprid의 잔류량은 7-8월 시설재배지의 아스파라거스를 입경 전과 후 상태가 되도록 제작하고 수확 7일전 1회 살포하여 1-2일 간격으로 5회에 거쳐 어린 줄기를 수확한 후 분석하였다. 그 결과, 입경 전과 후 아스파라거스 모두에서 살포당일 acetamiprid의 잔류량은 0.27 mg/kg과 0.14 mg/kg으로 적용되는 최저 잔류허용기준인 0.1 mg/kg 보다 높은 것으로 확인되었으나, 3일이 경과하였을 때는 잔류허용기준 보다 낮은 0.08 mg/kg과 0.03 mg/kg 수준임을 확인할 수 있었다. 그리고 살포 후 5일이 경과하였을 때는 입경 전과 후 아스파라거스 모두에서 본 연구의 acetamiprid 정량한계인 0.02 mg/kg 보다 낮아져 검출이 되지 않았다. 이러한 결과로 미루어볼 때 7-8월 시설재배지의 아스파라거스에서 acetamiprid 반감기는 입경과 무관하게 1-3일 정도로 짧음을 알 수 있었다. 따라서 acetamiprid 입상수화제를 7-8월 시설재배지의 아스파라거스에 수확 7일전에 1회 살포하는 것은 아스파라거스의 농약잔류 안전성에 문제가 되지 않을 것으로 판단하였으며, 본 연구결과는 아스파라거스에 대한 acetamiprid의 안전사용기준을 설정하는데 중요한 기초자료가 될 것으로 사료된다.

Comparison of Nitrogen Metabolism in Yak (Bos grunniens) and Indigenous Cattle (Bos taurus) on the Qinghai-Tibetan Plateau

  • Wang, Hucheng;Long, Ruijun;Liang, Juan Boo;Guo, Xusheng;Ding, Luming;Shang, Zhanhuan
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권6호
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    • pp.766-773
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    • 2011
  • The objective of the present study was to examine whether yaks possess any adaptive mechanisms of nitrogen (N) metabolism to survive in the harsh foraging environment of the Qinghai-Tibetan Plateau. A grazing experiment on native alpine meadows was conducted to determine availability of herbage biomass and body weight (BW) change of yaks over the year, followed by two indoor feeding trials to investigate adaptation mechanisms of N metabolism in yaks fed at similar intake level to grazing conditions. Three castrated males of each of three genotypes; yak (Bos grunniens), indigenous cattle (Bos taurus) and their crossbred - cattleyak (Bos taurus male${\times}$Bos grunniens female), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.

농어(Lateolabrax japonicus)의 초기 생활사 (Early Life History of the Sea Bass, Lateolabrax japonicus(Cuvier))

  • 한경호;이원교;양석우;오성현;신상수
    • 한국어류학회지
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    • 제11권1호
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    • pp.94-101
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    • 1999
  • 1998년(年) 11월(月)부터 1999년(年) 1월(月)까지 전라남도 여수시 돌산읍 소재의 종묘배양장에서 사육중이던 농어에 황체 자극호르몬-방출호르몬 유사체를 투여하여 인위적으로 채란(採卵)한 난(卵)의 형태와 인공수정(人工受精)한 후 난발생과정(卵發生過程) 및 자치어(仔稚魚)의 성장에 따른 형태변화를 관찰하였다. 농어의 수정란(受精卵) 및 미수정란(米受精卵)은 구형(球形)으로 무색투명하였으며, 수정란(受精卵)의 난경(卵徑) 1.33~1.46 mm (평균 1.38 mm, n=10) 이었고, 유구(油球)는 1~5개를 가지고 있었다. 부화(孵化)에 소요된 시간은 수온 $20.0^{\circ}C$에서 50시간 45분, $18.0^{\circ}C$ 에서 54시간 55분, $16.0^{\circ}C$에서 74시간 15분이 소요되었다. 부화(孵化) 직후(直後)의 자어(仔魚)는 전장(全長)이 3.54~3.69 mm로 입은 열리지 않았으나 항문이 열려있었고, 눈에는 색소포(色素脯)가 연하게 착색(著色)되어 있었다. 부화(孵化) 후(後) 5일(日)째의 자어(仔魚)는 전장(全長)이 4.78~5.24 mm로 난황(卵黃)이 완전히 흡수되어 후기자어기로 이행하였고, 머리 부분이 현격하게 발달하면서 입이 완전하게 열려있으며, 흑색소포(黑色素胞)가 몸의 등쪽과 배쪽에서 증가하였다. 부화(孵化) 후(後) 25일(日)째 자어(仔魚)는 전장(全長)이 7.95~8.32 mm로 꼬리지느러미에 9~12개의 줄기가 출현하였으며, 두경부(頭項部)와 후경부(後頭部)에서 꼬리부분까지 나무가지 모양의 흑색소포(黑色素胞)가 증가하여 나타났다. 부화(孵化) 후(後) 31일(日)째 자어(仔魚)는 전장(全長)이 8.46~9.18 mm로 배색말단(背索末端)이 $45^{\circ}$로 굽어져 있으며, 막상(膜狀)의 지느러미가 분화하여 등지느러미에 8~9개, 뒷지느러미에 7~8개의 줄기가 출현하였고, 꼬리지느러미 줄기는 16~18개로 증가하여 나타났다. 부화(孵化) 후(後) 61일(日)째 개체의 전장(全長)은 16.28~17.31 mm로 모든 지느러미 줄기가 정수 (D. XII, 14; A. II, 10; P. 18; V. 10; C. 20~21)에 달하여 유어기(維魚期)로 이행하였다.

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