DISCOVERY OF A FAINT QUASAR AT <i>z</i> ∼ 6 AND IMPLICATIONS FOR COSMIC REIONIZATION

Kim, Yongjung,Im, Myungshin,Jeon, Yiseul,Kim, Minjin,Choi, Changsu,Hong, Jueun,Hyun, Minhee,Jun, Hyunsung David,Karouzos, Marios,Kim, Dohyeong,Kim, Duho,Kim, Jae-Woo,Kim, Ji Hoon,Lee, Seong-Kook,Pak, IOP Publishing 2015 ASTROPHYSICAL JOURNAL LETTERS - Vol.813 No.2

<P>Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars (M-1450 > -24 mag) at z greater than or similar to 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z similar to 6 in a 12.5 deg(2) region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at similar to 8443 angstrom, with emission lines redshifted to z = 5.944 +/- 0.002 and rest-frame ultraviolet continuum magnitude M-1450 = -23.59 +/- 0.10 AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z similar to 6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars. This suggests that the number of M-1450 similar to 23 mag quasars at z similar to 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.</P>

석면관련 폐질환의 진단에 있어서 흉부고해상도전산화단층촬영검사(HRCT)의 유용성

이현재,손지언,,홍영습,,이영일,예병진,유창훈,정갑열,김상훈,임형준,장은철,김정만,김준연 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 석면에 노출된 근로자에서 석면관련 폐질환의 양상을 분석하고 진단에 있어 HRCT의 유용성을 연구하여 석면에 대한 의학적 감시프로그램의 개발에 기여하고자 하였다. 방법: 석면에 직접 노출되는 작업자 68명과 간접 노출되는 작업자 94명 등 총 162명에 대해 OSHA 석면 표준, 의학적 감시 프로그램에 따라 단순 흉부방사선검사, 폐활량검사 및 우리나라 실정에 맞게 일부 수정한 의학적 설문지를 통해 면접조사의 방식으로 환자에 관한 정보를 수집하였으며, 자료의 신뢰성을 확보하기 위하여 면접조사는 1달 이상의 기간을 두고 2차례에 걸쳐 실시된 후 확인, 수정하였다. 또한, 석면관련 폐질환을 확진하기 위하여 HRCT를 추가적으로 실시하였다. 결과: HRCT결과 석면관련 폐질환의 유병율은 162명의 근로자중 17명으로 10.5%였는데, 직접 노출군에서 10명 (14.7%), 간접 노출군에서 7명 (7.4%)이었다. HRCT와 비교할 때 단순 흉부방사선검사의 민감도와 특이도는 각각 70.6%와 98.6%이었고, 양성 예측도와 음성 예측도는 각각 85.7%와 96.6%으로, HRCT는 단순흉부방사선검사에 비해 민감도가 높아 초기 석면관련 폐질환을 진단하는데 효과적이었다. 석면관련 폐질환의 진단에 있어 HRCT와 폐활량검사 사이에 유의한 관련성이 관찰되었다. HRCT 결과 석면관련 폐질환의 유무와 의학적 설문조사 결과의 빈도분석을 실시한 결과, 유의한 변수는 작업기간, 흡연량, 호흡기질환의 과거력, 기침, 호흡곤란이었다. 결론: HRCT는 석면관련 폐질환의 진단에 있어 단순 흉부방사선검사와 비교하여 민감도가 높아 초기 진단에 유용하므로 단순 흉부방사선선검사 결과 석면관련 폐질환소견을 보일 때뿐만 아니라, 정상소견을 보이더라도 폐활량 검사결과와 근무력, 흡연력, 호흡기질환의 과거력, 기침, 호흡곤란 등의 호흡기 증상을 참고하여 HRCT검사를 고려해야 한다. 또한, 본 연구에서 관련성이 없었던 요인들에 대해서도 향후 연관성을 규명하는 광범위한 전향적 연구가 필요하다. Objectives: This study was carried out to improve the medical surveillance program of workers exposed to asbestos by examining the usefulness of High Resolution Computed Tomography (HRCT) in the diagnosis of asbestos-related lung disease. Methods: The study subjects comprised 162 workers in a ship-repairing yard, 68 of whom had been directly exposed to asbestos and 94 indirectly exposed. The 'Occupational Safety & Health Administration (OSHA) asbestos standard, medical surveilance program' and HRCT were conducted to analyze the aspects of the asbestos-related lung disease. The OSHA asbestos standard, medical surveilance program consists of simple chest x-ray, spirometry and medical questionnarie. Results: Seventeen (10.5%) of the 162 subjects, 10 (14.7%) directly exposed and 7 (7.4%) indirectly exposed, revealed asbestos-related lung disease on HRCT. The sensitivity and specificity of simple chest x-ray for asbestos-related lung disease were 70.6% and 98.6%, and the positive and negative predictive values were 85.7% and 96.6% respectively, as compared with HRCT, HRCT was an effective diagnostic tool especially to detect early asbestos-related lung disease. The study results indicated a relative significant association between the results of spirometry and HRCT. The variables significantly associated with asbestos-related lung disease on HRCT were work duration, smoking history (pack-years), past history of respiratory disease, cough and dyspnea. Conclusions: In the diagnosis of asbestos-related lung disease, HRCT should be considered not only for workers with positive findings on simple chest x-ray, but also workers with specific findings on spirometry, occupational history, smoking history, and past history of respiratory disease, or with respiratory symptoms such as cough and dyspnea.

경증 천식 환아에서 비염의 동반이 하기도 호산구 염증에 미치는 영향

한지은,이미현,송도영,강임주 대한 소아알레르기 및 호흡기학회 2004 소아알레르기 및 호흡기학회지 Vol.14 No.2

호장근 추출물의 Helicobacter pylori에 대한 생육억제 및 인간 위암세포주에 대한 유전적 손상 유도

박정현,김현정,이지원,임효권,이인선 대한암예방학회 2003 Journal of cancer prevention Vol.8 No.2

Usefulness of the Cytomegalovirus Antigenemia Assay in Patients With Ulcerative Colitis

( Jaeyoung Chun ),( Changhyun Lee ),( Ji Eun Kwon ),( Sung Wook Hwang ),( Sang Gyun Kim ),( Joo Sung Kim ),( Hyun Chae Jung ),( Jong Pil Im ) 대한장연구학회 2015 Intestinal Research Vol.13 No.1

Background/Aims: Patients with ulcerative colitis (UC) are at high risk for cytomegalovirus (CMV) reactivation. The useful-ness of the CMV antigenemia assay in active UC patients has rarely been studied. We assessed whether the assay detects CMV colitis and predicts clinical outcomes in patients with UC. Methods: We retrospectively reviewed the medical records of pa-tients hospitalized for moderate-to-severe UC from 2003 to 2012. Positive CMV antigenemia was defined as ≥1 pp65-positive cell per 2×105 polymorphonuclear neutrophils. CMV colitis was defined as the presence of inclusion bodies and/or positive im-munohistochemistry in the colonic mucosa. The primary outcome was steroid refractoriness, defined as the absence of clinical improvement after intravenous high-dose steroid administration. Results: A total of 43 patients were enrolled. CMV antigen-emia was detected in 12 (27.9%) patients. Positive CMV antigenemia was significantly associated with CMV colitis (P=0.001). The sensitivity and specificity of positive CMV antigenemia for diagnosing CMV colitis were 66.7% and 87.1%, respectively. Steroid refractoriness was found in 11 of 12 (91.7%) and 12 of 31 (38.7%) patients with positive and negative CMV antigenemia, respectively (P=0.002). The independent predictors for steroid refractoriness were positive CMV antigenemia (adjusted odds ratio [OR], 7.73; 95% confidence interval [CI], 1.22-49.19; P=0.030) and a shorter duration from the diagnosis of UC (adjusted OR, 0.99; 95% CI, 0.98-0.99; P=0.025). Conclusions: The CMV antigenemia assay shows low sensitivity but high specificity for detecting CMV colitis and may predict steroid-refractory UC. Early rescue therapy might be considered in UC patients positive for CMV antigenemia. (Intest Res 2015;13:50-59)

Risk factors for recurrence of node-negative breast cancer with less than 1cm (초)

( Ji Hyun Kwon ),( Yu Jung Kim ),( Do Youn Oh ),( So Yeon Park ),( Jee Hyun Kim ),( Eui Kyu Chie ),( Sung Won Kim ),( Won Shik Han ),( Seock Ah Im ),( In Ah Kim ),( Tae You Kim ),( In Ae Park ),( Dong 대한내과학회 2008 대한내과학회지 Vol.75 No.1S

Needs and gaps of faculty development for medical schools

Ji Hyun Im,Wha Sun Kang,Seung Hee Lee,Dae Chul Jeong,Dae Hyun Kim,Man-Sup Lim,Miran Kim,Ji-Hyun Seo,Dong Hyeon Lee 한국의학교육학회 2024 Korean journal of medical education Vol.36 No.2

Purpose: Current faculty development (FD) programs are mostly limited to medical education and often lack a comprehensive and systematic structure. Therefore, the present study aimed to explore the current status and needs of FD programs in medical schools to provide a basis for establishing FD strategies. Methods: We conducted an online survey of medical school FD staff and professors regarding FD. Frequency, regression, and qualitative content analyses were conducted. FD programs were categorized into the classification frameworks. Results: A total of 17 FD staff and 256 professors at 37 medical schools participated. There are gaps between the internal and external FD programs offered by medical schools and their needs, and there are gaps between the programs the professors participated in and their needs. Recent internal and external FD programs in medical schools have focused on educational methods, student assessment, and education in general. Medical schools have a high need for leadership and self-development, and student assessment. Furthermore, professors have a high need for leadership and self-development, and research. The number of participants, topics, and needs of FD programs varied depending on the characteristics of individual professors. Conclusion: Medical schools should expand their FD programs to meet the needs of individuals and the changing demands of modern medical education. The focus should be on comprehensive and responsive programs that cover various topics, levels, and methods. Tailored programs that consider professors’ professional roles, career stages, and personal interests are essential for effective FD.

Effect of Various Pretreatment and Thawing Methods on Quality Characteristic of Frozen Carrot and Potato

Ji-Hyun Im,A-Ra Ko,Hee-Jung Jin,Duri Kim,Jung-Hyun Nam,Ji-Yeon Chun 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

This study investigated the effect of various blanching and thawing methods on frozen carrots and potatoes by individual quick freezing (-35°C). Carrots and potatoes were cut into 1×1×1 cm cubes and then blanched by using steam blanching (SB) and hot water blanching (HB). Frozen samples were thawed by room temperature thawing (RT), running water thawing (WT), and microwave thawing (MT). Sample qualities such as drip loss, pH, color, vitamin C, hardness, DPPH radical scavenging activity, and total polyphenol content were evaluated. Freezing and thawing time had no difference according to blanching method. In the freezing process, carrots and potatoes took 37 min and 40 min to reach -35°C, respectively. In the thawing process, MT was the most rapid thawing time, and RT took more than twice as long as WT. Overall, SB and HB had lower drip loss and higher moisture content than control (nontreatment). It was proved that the samples quality were maintained by blanching and when carrots or potatoes were thawed by RT or WT method, respectively, they showed the optimal quality in drip loss, moisture content, DPPH radical scavenging activity, and vitamin C.

Is it feasible and effective to provide faculty development programs online for clinical teachers?

Ji Hyun Im,Ju Whi Kim,Wan Beom Park,Ilkyu Han,Seung Hee Lee,Jwa Seop Shin,Hyun Bae Yoon 한국의학교육학회 2021 Korean journal of medical education Vol.33 No.2

Purpose: Seoul National University College of Medicine operates a faculty development program for clinical teachers at multiple affiliated teaching hospitals. In 2020, the program was moved online due to coronavirus disease 2019. The purpose of this study was to determine whether it is feasible and effective to provide faculty development programs online in terms of clinical teachers’ participation and satisfaction in comparison with offline programs. Methods: Clinical teachers participated in the clinical teaching methods programs offline in 2019 and online in 2020. We analyzed participation rate and satisfaction level. All surveys items were rated on a 5-point Likert scale. We also interviewed instructors about the advantages and drawbacks of the online program. Results: The participation rate of the online program (89.5%) was significantly higher than that of the offline program (67.8%). The overall satisfaction level for the online program (4.37) was similar to that for the offline program (4.50). Conclusion: Faculty development programs online are feasible and effective in medical education. We need to design training content that fits online programs, consider various online training methods to reinforce the strengths of online programs, and support participants to make good use of these programs.

Antiplatelet and Antithrombotic Activities of Korean Red Ginseng

Ji Yeon Yu,Yong-Ri Jin,이정진,정진호,Ji-Yoon Noh,Soon-Hyang You,김기남,Ji-Hyun Im,Ju-Hyun Lee,Ji-Min Seo,Hyeong-Jun Han,임용,Eun-Seok Park,김택중,신경섭,Jae-Joon Wee,Jong-Dae Park,윤여표 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.10

The antiplatelet and antithrombotic activities of Korean Red Ginseng (KRG) were examined on rat carotid artery thrombosis in vivo, and platelet aggregation in vitro and ex vivo. Administration of KRG to rats not only prevented carotid artery thrombosis in vivo in a dose-dependent manner, but also significantly inhibited ADP- and collagen-induced platelet aggregation ex vivo, while failed to prolong coagulation times such as activated partial thromboplastin time (APTT) and prothrombin time (PT), indicating the antithrombotic effect of KRG might be due to its antiplatelet aggregation rather than anticoagulation effect. In line with the above observations, KRG inhibited U46619-, arachidonic acid-, collagen- and thrombin-induced rabbit platelet aggregation in vitro in a concentration-dependent manner, with IC50 values of 620 ± 12, 823 ± 22, 722 ± 21 and 650 ± 14 μg/mL, respectively. Accordingly, KRG also inhibited various agonists- induced platelet serotonin secretions as it suppressed platelet aggregation. These results suggest that KRG has a potent antithrombotic effect in vivo, which may be due to antiplatelet rather than anticoagulation activity, and KRG intake may be beneficial to the individuals with high risks of thrombotic and cardiovascular diseases.