• 제목/요약/키워드: Harvard University

검색결과 377건 처리시간 0.027초

당귀(當歸)와 황기(黃芪)의 배합 변화가 DPPH 자유기 소거에 미치는 영향 연구 (Compositions of Astragali Radix and Angelicae Radix by DPPH Radical Scavenging Activity)

  • 강순아;오명숙;김도림;강지웅;김원남;박은화;장문석;박성규
    • 대한본초학회지
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    • 제21권1호
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    • pp.17-24
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    • 2006
  • Objectives : This study was conducted to compare antioxidant activity of ratio-related Angelicae Radix and Astragali Radix compositions by DPPH radical scavenging activity. Methods : The species of Angelicae Radix was compared as Angelica gigas, A. sinensis and A. acutiloba. Then various compositions of Angelicae Radix with Astragali Radix were prepared with different ratio. Diphenyl-picryl-hydrazyl (DPPH) radical scavenging activity was measured after 10, 20 and 30 minutes. Each extracts were tested by 1, 5, 10, 50, 100, 500 and 1,000 ${\mu}g/ml$ concentrations. Results : The results showed that Angelica gigas, A. sinensis and A. acutiloba scavenged DPPH radical with 66.8, 61.7 and 56.7% in 1,000 ${\mu}g/ml$ concentration, respectively. According to this result, Angelicae Radix and Astragali Hadix compositions with 100:0, 10:1, 5:1, 3:1, 1:1, 1:3, 1:5, 1:10 and 0:100 ratio were scavenged DPPH radical with 56.3, 49.9, 61.2, 55.7, 54.7, 55.0, 52.8 ,md 50.2% in 1,000 ${\mu}g/ml$ concentration, respectively. The extract of Angelicae Radix and Astragali Radix compositions with 100:0, 10:1, 5:1, 3:1, 1:1, 1:3, 1:5, 1:10 and 0:100 ratio scavenged DPPH radical with the $IC_{50}$ being 85,21, 1016.26, 656.51, 785.67 and 956.74 ${\mu}g/ml$ respectively. Conclusion : In conclusion, the extract of Angelicae Radix and Astragali Radix compositions with 1:1 ratio showed dose-dependent DPPH radical scavenging activity.

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FREE-FLOATING PLANETS, THE EINSTEIN DESERT, AND 'OUMUAMUA

  • Gould, Andrew;Jung, Youn Kil;Hwang, Kyu-Ha;Dong, Subo;Albrow, Michael D.;Chung, Sun-Ju;Han, Cheongho;Ryu, Yoon-Hyun;Shin, In-Gu;Shvartzvald, Yossi;Yang, Hongjing;Yee, Jennifer C.;Zang, Weicheng;Cha, Sang-Mok;Kim, Dong-Jin;Kim, Seung-Lee;Lee, Chung-Uk;Lee, Dong-Joo;Lee, Yongseok;Park, Byeong-Gon;Pogge, Richard W.
    • 천문학회지
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    • 제55권5호
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    • pp.173-194
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    • 2022
  • We complete the survey for finite-source/point-lens (FSPL) giant-source events in 2016-2019 KMTNet microlensing data. The 30 FSPL events show a clear gap in Einstein radius, 9 𝜇as < 𝜃E < 26 𝜇as, which is consistent with the gap in Einstein timescales near tE ~ 0.5 days found by Mróz et al. (2017) in an independent sample of point-source/point-lens (PSPL) events. We demonstrate that the two surveys are consistent. We estimate that the 4 events below this gap are due to a power-law distribution of free-floating planet candidates (FFPs) dNFFP/d log M = (0.4 ± 0.2) (M/38 M)-p/star, with 0.9 ≲ p ≲ 1.2. There are substantially more FFPs than known bound planets, implying that the bound planet power-law index 𝛾 = 0.6 is likely shaped by the ejection process at least as much as by formation. The mass density per decade of FFPs in the Solar neighborhood is of the same order as that of 'Oumuamua-like objects. In particular, if we assume that 'Oumuamua is part of the same process that ejected the FFPs to very wide or unbound orbits, the power-law index is p = 0.89 ± 0.06. If the Solar System's endowment of Neptune-mass objects in Neptune-like orbits is typical, which is consistent with the results of Poleski et al. (2021), then these could account for a substantial fraction of the FFPs in the Neptune-mass range.

NK cell-activating receptor NKp46 does not participate in the development of obesity-induced inflammation and insulin resistance

  • Gracia Nathalie;Beatriz Dal Santo Francisco Bonamichi;Jieun Kim;Jiwon Jeong;Haneul Kang;Emirrio Reinaldie Hartland;Eveline Eveline;Jongsoon Lee
    • Molecules and Cells
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    • 제47권3호
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    • pp.100007.1-100007.11
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    • 2024
  • Recent evidence establishes a pivotal role for obesity-induced inflammation in precipitating insulin resistance and type-2 diabetes. Central to this process is the proinflammatory M1 adipose-tissue macrophages (ATMs) in epididymal white adipose tissue (eWAT). Notably, natural killer (NK) cells are a crucial regulator of ATMs since their cytokines induce ATM recruitment and M1 polarization. The importance of NK cells is shown by the strong increase in NK-cell numbers in eWAT, and by studies showing that removing and expanding NK cells respectively improve and worsen obesity-induced insulin resistance. It has been suggested that NK cells are activated by unknown ligands on obesity-stressed adipocytes that bind to NKp46 (encoded by Ncr1), which is an activating NK-cell receptor. This was supported by a study showing that NKp46-knockout mice have improved obesity-induced inflammation/insulin resistance. We therefore planned to use the NKp46-knockout mice to further elucidate the molecular mechanism by which NKp46 mediates eWAT NK-cell activation in obesity. We confirmed that obesity increased eWAT NKp46+ NK-cell numbers and NKp46 expression in wild-type mice and that NKp46-knockout ablated these responses. Unexpectedly, however, NKp46-knockout mice demonstrated insulin resistance similar to wild-type mice, as shown by fasting blood glucose/insulin levels and glucose/insulin tolerance tests. Obesityinduced increases in eWAT ATM numbers and proinflammatory gene expression were also similar. Thus, contrary to previously published results, NKp46 does not regulate obesity-induced insulin resistance. It is therefore unclear whether NKp46 participates in the development of obesity-induced inflammation and insulin resistance. This should be considered when elucidating the obesity-mediated molecular mechanisms that activate NK cells.

미세전류 적용이 편평족을 가진 사람들의 보행근육 피로도에 미치는 영향 (The Effect of Microcurrent Application on Muscle Fatigue of Pes Planus during Gait)

  • 이대환;손호희;박수진;김진상;김경
    • 대한물리치료과학회지
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    • 제18권2호
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    • pp.51-62
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of microcurrent on fatigue of muscles in people who were flat-footed during gait. Methods: 10 flat-footed university students volunteered to participate in this study. 10 flat-footed subjects were divided into 2 groups, one group was experimental group of 5subjects(This group put on microcurrent induction shoes but the subjects were not able to feel the current.) and the other group was the control group of 5subjects(This group put on the general shoes which were similar in shape but microcurrent was not induced.) to perform double blind test and random sampling. Their gait muscle fatigue of 6 regions (vastus medialis, gastrocnemius, tibialis anterior, biceps femoris, erector spinae, and rectus abdominis muscle.) was measured by EMG MP150, Delsys Inc Boston, USA during walking and then they carried out the Harvard step with a platform (It was a arbitrarily made wooden platform of 100cm long, 50cm wide, 60cm high. They carried out climbing it for one second and descending it for one second by using the Metronome program, total 5minutes) for 5minutes. Right after that, the subjects walked on a treadmill at a speed of 4km/h for 10minutes and then their gait muscle fatigue of 6regions was assessed while they were walking on the ground as equally as before exercise. Results: The experimental group has resulted in lower average differences in gait muscle fatigue before and after exercise than those of the control group average 12.24Hz(P=0.009) at vastus medialis, average 8.52Hz(P=0.016) at gastrocnemius, average 9.16Hz(P=0.009) at tibialis anterior, average 8.66Hz(P=0.047) at biceps femoris, average 7.53Hz(P=0.016) at erector spinae, and average 7.80Hz(P=0.047) at rectus abdominis. All of the assessments of muscles have shown significant difference statistically. Conclusions: This result has shown that the use of micro current could decrease gait muscle fatigue of flat-footed people. It is recommended to use a microcurrent to reduce their gait muscle fatigue.

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Contribution of a Low-Barrier Hydrogen Bond to Catalysis Is Not Significant in Ketosteroid Isomerase

  • Jang, Do Soo;Choi, Gildon;Cha, Hyung Jin;Shin, Sejeong;Hong, Bee Hak;Lee, Hyeong Ju;Lee, Hee Cheon;Choi, Kwan Yong
    • Molecules and Cells
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    • 제38권5호
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    • pp.409-415
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    • 2015
  • Low-barrier hydrogen bonds (LBHBs) have been proposed to have important influences on the enormous reaction rate increases achieved by many enzymes. ${\Delta}^5$-3-ketosteroi isomerase (KSI) catalyzes the allylic isomerization of ${\Delta}^5$-3-ketosteroid to its conjugated ${\Delta}^4$-isomers at a rate that approache the diffusion limit. Tyr14, a catalytic residue of KSI, has been hypothesized to form an LBHB with the oxyanion of a dienolate steroid intermediate generated during the catalysis. The unusual chemical shift of a proton at 16.8 ppm in the nuclear magnetic resonance spectrum has been attributed to an LBHB between Tyr14 $O{\eta}$ and C3-O of equilenin an intermediate analogue, in the active site of D38N KSI. This shift in the spectrum was not observed in Y30F/Y55F/D38N and Y30F/Y55F/Y115F/D38N mutant KSIs when each mutant was complexed with equilenin, suggesting that Tyr14 could not form LBHB with the intermediate analogue in these mutant KSIs. The crystal structure of Y30F/Y55F/Y115F/D38N-equilenin complex revealed that the distance between Tyr14 $O{\eta}$ and C3-O of the bound steroi was within a direct hydrogen bond. The conversion of LBHB to an ordinary hydrogen bond in the mutant KSI reduced the binding affinity for the steroid inhibitors by a factor of 8.1-11. In addition, the absence of LBHB reduced the catalytic activity by only a factor of 1.7-2. These results suggest that the amount of stabilization energy of the reaction intermediate provided by LBHB is small compared with that provided by an ordinary hydrogen bond in KSI.

한국과 미국 대학생의 간접음주피해 비교 (A Comparison of Alcohol Secondhand Effects among Korean and U.S. College Students)

  • Chun, Sung-Soo;Sohn, Ae-Ree;Reid, Easton A.;Inot, Rubelyn;Kim, Mi-Kyung;Percoheles, Grace;Lee, Sang-Sook;Wechsler, Henry
    • 보건교육건강증진학회지
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    • 제26권5호
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    • pp.115-127
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    • 2009
  • 목적: 이 연구는 한국과 미국대학생의 음주로 인한 간접피해수준을 상대적으로 비교하기 위해 설계되었다. 방법: 하버드대학교의 대학생음주연구(CAS)의 2001년도의 원자료 10,924명의 데이터와 한국대학생음주연구(KCAS)의 2003년도의 원자료 2,385명의 데이터를 하나의 파일에 함께 넣어서 분석하였다. 조사도구는 CAS의 대학생용 조사설문지를 사용하였으며, 한국의 주종과 량과 관련하여서는 표준잔과 량을 기준으로 적용하였다. 지난 한 달 동안의 음주하였다고 한 학생의 알코올관련문제 및 간접피해의 정도를 비교하였으며, 연령과 음주빈도 와 음주량 통제하여 로지스틱회귀분석의 결과로 제시하였다. 결과: 한국대학생들이 술 취한 동료를 돌봄, 성적인 폭행, 데이트 강간, 구토물들을 발견하는 것 등의 간접피해를 많이 받는 반면에 미국대학생들은 모욕을 당함, 심하게 다툼, 밀침을 당함, 학업에 방해를 받음, 폭행을 당함, 원치 않은 섹스를 함 등의 간접피해를 더 많이 겪고 있다. 결론: 미국대학생들은 상호관계에 의한 간접피해를 많이 느끼는데 비해서, 한국대학생들은 개인적이고 신체적인 간접피해를 더 많이 느끼고 있다.

토머스 제퍼슨의 버지니아대학교 식물원 구상 배경과 내용 (The Background and Content of Thomas Jefferson's Plan for a Botanical Garden for the University of Virginia)

  • 김정화
    • 한국조경학회지
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    • 제47권3호
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    • pp.49-59
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    • 2019
  • 본 연구는 토머스 제퍼슨의 버지니아대학교 식물원 구상의 배경과 내용을 고찰한다. 제퍼슨이 식물원 설립을 추진했던 시기가 유럽에서 식물원이 약용 식물원에서 진화한 때이자 미국에서 여러 식물원이 설립된 초창기라는 사실에 주목하여 동시대 식물원과 비교하여 버지니아대학교 식물원 구상의 특징을 짚어내고자 하였다. 이를 위해 19세기 전후 구미 주요 식물원의 역할과 공간 구조를 분석하여 경향을 파악하였다. 이와 함께 식물학과 식물원에 대한 제퍼슨의 관점과 식물원 구상안을 검토하며 버지니아대학교 식물원을 당대 사례와 비교 검토하였다. 연구 결과 그 배경은 18세기 후반 유럽에서 두드러지게 나타난 국가 경제를 견인하는 실용 과학으로서 식물 교육과 연구의 중요성에 대한 사회 인식, 그리고 식물학과 식물원에 대한 정보와 식물을 교환하는 네트워크에서 찾을 수 있다. 버지니아대학교 식물원 구상은 공공 식물원의 역할에 대한 식물학자 코레아의 의견이 바탕이 되어 제퍼슨에 의해 부지 조성과 개략적인 공간 구성, 식물 수급 방안을 포함한 실행 전략으로 발전되었다. 동시대 식물원 사이에서 버지니아대학교 식물원 구상이 지니는 특징은 다음과 같다. 첫째, 초본 이외에 교목 정원을 별도로 구성하고 의학이 아닌 식물학 연구와 교육을 강조했던 측면에서 18세기 후반 유럽 식물원의 약용 식물원에서 식물원으로의 진화와 같은 경향을 보인다. 둘째, 장식적 요소를 배제하고 온실 설치를 거부하며 지역 기후에 적합한 해외 실용 식물을 확산시키려 했다는 점에서 유럽과 미국의 많은 식물원과 다르다. 본 연구는 버지니아대학교 식물원 구상을 사례로 19세기 전후 식물원의 역사와 문화에 대한 이해의 폭을 넓히는데 기여한다는 점에서 의의를 지닌다.

Treatment of Human Thyroid Carcinoma Cells with the G47delta Oncolytic Herpes Simplex Virus

  • Wang, Jia-Ni;Xu, Li-Hua;Zeng, Wei-Gen;Hu, Pan;Rabkin, Samuel D.;Liu, Ren-Rin
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.1241-1245
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    • 2015
  • Background: Thyroid carcinoma is the most common malignancy of the endocrine organs. Although the majority of thyroid cancer patients experience positive outcomes, anaplastic thyroid carcinoma is considered one of the most aggressive malignancies. Current therapeutic regimens do not confer a significant survival benefit, and new therapies are urgently needed. Oncolytic herpes simplex virus (oHSV) may represent a promising therapy for cancer. In the present study, we investigated the therapeutic effects of a third-generation HSV vector, $G47{\Delta}$, on various human thyroid carcinoma cell lines in vitro. Two subcutaneous (s.c.) models of anaplastic thyroid carcinoma were also established to evaluate the in vivo anti-tumor efficacy of $G47{\Delta}$. Materials and Methods: The human thyroid carcinoma cell line ARO, FRO, WRO, and KAT-5, were infected with $G47{\Delta}$ at different multiplicities of infection (MOIs) in vitro. The survival rates of infected cells were calculated each day. Two s.c. tumor models were established using ARO and FRO cells in Balb/c nude mice, which were intratumorally (i.t.) treated with either $G47{\Delta}$ or mock. Tumor volumes and mouse survival times were documented. Results: $G47{\Delta}$ was highly cytotoxic to different types of thyroid carcinomas. For ARO, FRO, and KAT-5, greater than 30% and 80% of cells were killed at MOI=0.01 and MOI=0.1, respectively on day 5. WRO cells displayed modest sensitivity to $G47{\Delta}$, with only 21% and 38% of cells killed. In the s.c. tumor model, both of the anaplastic thyroid carcinoma cell lines (ARO and FRO) were highly sensitive to $G47{\Delta}$; $G47{\Delta}$ significantly inhibited tumor growth and prolonged the survival of mice bearing s.c. ARO and FRO tumors. Conclusions: The oHSV $G47{\Delta}$ can effectively kill different types of human thyroid carcinomas in vitro. $G47{\Delta}$ significantly inhibited growth of anaplastic thyroid carcinoma in vivo and prolonged animal survival. Therefore, $G47{\Delta}$ may hold great promise for thyroid cancer patients.

양성자 선량 분포 검증을 위한 즉발감마선 분포측정 장치 최적화 연구 (Study on Optimization of Detection System of Prompt Gamma Distribution for Proton Dose Verification)

  • 이한림;민철희;박종훈;김성훈;김찬형
    • 한국의학물리학회지:의학물리
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    • 제23권3호
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    • pp.162-168
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    • 2012
  • 양성자 치료에서 치료의 목표를 달성하고 환자의 안전을 제고하기 위해 인체 내 양성자 빔의 분포를 확인하는 것이 중요하다. 양성자 선량분포와 밀접한 관계가 있는 즉발감마선의 2차원 분포 측정을 위하여 본 연구팀에서는 다수의 CsI(Tl) 섬광체가 1차원 종형으로 배열된 검출기 배열과 집속장치 및 다채널 신호처리 장치로 이루어진 측정장치를 개발하고 있다. 이에 본 연구에서 몬테칼로 기반의 MCNPX 코드를 이용하여 최적화된 측정 장치를 설계하고자 하였다. 즉발감마선을 효과적으로 측정하기 위해 CsI(Tl) 섬광체의 크기를 $6{\times}6{\times}50mm^3$로 결정하였으며, 배경감마선의 영향을 최소화하고 빔의 진행방향에서 수직방향으로 발생하는 즉발감마선만 측정하기 위해 집속장치의 구멍 크기는 면적 $6{\times}6mm^2$, 길이 150 mm로 최적화되었다. 150 MeV 양성자 빔에 대한 성능 예측 전산모사연구를 수행한 결과, 본 연구에서 최적화된 측정 장치를 통해 즉발감마선 2차원 분포를 측정할 수 있었으며, 1 mm 오차범위에서 양성자 빔의 비정을 결정할 수 있었다. 이를 바탕으로 현재 다채널의 신호처리 장치를 개발하고 있으며 실제 양성자 빔을 이용한 즉발감마선 분포측정을 통해 측정 장치의 성능을 검증할 것이다.

THE PATIENTS' SATISFACTION FOLLOWING IMPLANT TREATMENT

  • Heo, Yoon-Young;Heo, Seong-Joo;Chang, Myung-Woo;Park, Ji-Man
    • 대한치과보철학회지
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    • 제46권6호
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    • pp.569-576
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    • 2008
  • STATEMENT OF PROBLEM: While patient-centered outcomes are usually not reported, these may represent major aspects of the implant success for the patient. Use of a well-designed patient survey form can be an invaluable asset to the implant practitioners. PURPOSE: The objective of this study was to investigate patient satisfaction after implant therapy by means of a questionnaire. MATERIAL AND METHODS: South Korean patients (n = 100), who visited the dental examination center of Soon Chun Hyang university hospital, were asked to fill out the satisfaction questionnaire regarding aspects of cost, comfort, esthetics, chewing, gingival health, food impaction, phonetic aspect, screw loosening, and general satisfaction. Responses to statements were given on the Likert response scale. Four experimental groups of patients were distinguished with various location ($A_1,\;A_2,\;A_3$), year ($B_1,\;B_2,\;B_3$), number of implant replacements ($C_1,\;C_2,\;C_3$), and treatment cost ($D_1,\;D_2,\;D_3$). The reliability of the response scales was measured by calculation of its internal consistency, expressed as Cronbach's ${\alpha}$. The scales were distinguished by means of factor analysis method. Possible differences in scale scores among the groups were assessed by One-way ANOVA (${\alpha}$= 0.05). RESULTS: Patients responded to most of the statements with high satisfaction. But the mean scale score of statement about cost was low. After the verification of internal consistency and factor analysis, five components, e.g. general satisfaction, comfort, chewing efficiency, esthetics, and phonetic aspect were grouped together. These components could be explained with common meaning and the first factor was named as 'general satisfaction'. Differences in patient satisfaction on the scale with esthetics were present between patients who have been wearing the implant prosthesis less than three years and those more than seven years ($B_1<B_3$). CONCLUSION: The patients were generally satisfied with the outcome of implant treatment. But the patients' major complaint was high cost and while the statistically significant difference was not shown, the satisfaction scale about food impaction and esthetics was low. So the continuing efforts to make improvements about these problems are needed for the implant practitioners.