684 research outputs found
Characterization of γ-H2AX foci formation under alpha particle and X-ray exposures for dose estimation
No full text© 2022, The Author(s).DNA double-strand break (DSB) induction is one of the phenotypes of cellular damage from radiation exposure and is commonly quantified by γ-H2AX assay with the number of excess fluorescent foci per cell as the main component. However, the number of foci alone may not fully characterize the state of DNA damage following exposures to different radiation qualities. This study investigated the feasibility of utilizing the focus size distribution and dephosphorylation rate of γ-H2AX to identify the type of causative radiation and dose. Human lung epithelial cells and mouse vascular endothelial cells were used to observe the expression changes of γ-H2AX foci due to alpha particle and X-ray exposures. Results showed that the average number of excess foci per cell linearly increased with the dose. The focus size distribution showed a consistent pattern depending on the causative radiation type. Three criteria for the identification of causative radiation type were derived from experimental focus size distributions and were validated in blind testing with correct identification of 27 out of 32 samples. The dose could be estimated based on the proportionality constant specific to the identified radiation type with a difference of less than 15% from the actual value. The different dephosphorylation rates of γ-H2AX produced from alpha particle and X-ray exposures were effectively utilized to determine the individual dose contributions of alpha particles and X-rays under mixed beam exposure. Individual doses were estimated to have differences of less than ~ 12% from actual values.Y
Electrodeposition of pure Sn electrodes with various structures and their electrochemical performances for Na-ion batteries
No full textMarket Power and the Downsizing of Democracy. Globalization, Communication and Economic Elites in South Korea
No full textMedia and communications engage in social power relations. This thesis aims to investigate the “power value” of media and communications, focusing on the private communication practices of economic elites. The main argument is that, in the age of hyperglobalization, elite private communication plays no less important a part than mass forms of communication in shaping and maintaining economic elite power that operates in a far from transparent and accountable manner. This detachment of media and communications from the public is a symptom of the shrinking of democracy, which sanctions the massive transfer of resources to the organized interests.
For the purpose of empirical study, his thesis investigates the sites or networks of the national and transnational market forces within the historical context of the neo-liberalization of the Korean economy and society since the 1990s. The research shows, via in-depth interviews and qualitative case studies, how increasingly broader areas of the economy are becoming discursively de-politicized and how the closed communicative processes of economic elites are replacing democratic structures. Think-tanks, epistemic communities and policy networks, with their practices of private communication, lobbying and “brain sharing”, often make policy decisions that have a significant impact on the masses. The discrete culture and exclusive elite communication networks which are prevalent in the global-national investment web of intermediaries allow the growth of “invisible power”, which almost completely blocks the vigilance of the public. In the financial market, the cohesive culture, combined with the reflexive and intensive communication environment, generates a system of preferences and evaluations as well as one-sided expectations that have a tremendous impact on corporate management and the whole of society.
The study suggests that we should attend to the growing tendency of the mediation of power that is taking place with minimum reference to the public. This research contributes to the understanding of the “power value” of media and communications by providing an alternative or complementary explanation
Perceived barriers to psychiatric help-seeking in South Korea by age groups: text mining analyses of social media big data
Get PDFBackground The psychiatric treatment gap is substantial in Korea, implying barriers in seeking help. Objectives This study aims to explore barriers of seeing psychiatrists, expressed on the internet by age groups. Methods A corpus of data was garnered extensively from internet communities, blogs and social network services from 1 January 2016 to 31 July 2019. Among the texts collected, texts containing words linked to psychiatry were selected. Then the corpus was dismantled into words by using natural language processing. Words linked to barriers to seeking help were identified and classified. Then the words from web communities that we were able to identify the age groups were additionally organized by age groups. Results 97,730,360 articles were identified and 6,097,369 were included in the analysis. Words implying the barriers were selected and classified into four groups of structural discrimination, public prejudice, low accessibility, and adverse drug effects. Structural discrimination was the greatest barrier occupying 34%, followed by public prejudice (27.8%), adverse drug effects (18.6%), and cost/low accessibility (16.1%). In the analysis by age groups, structural discrimination caused teenagers (51%), job seekers (64%) and mothers with children (43%) the most concern. In contrast, the public prejudice (49%) was the greatest barriers in the senior group. Conclusions Although structural discrimination may most contribute to barriers to visiting psychiatrists in Korea, variation by generations may exist. Along with the general attempt to tackle the discrimination, customized approach might be needed.N
Improved Dust Forecast by Assimilating MODIS IR-Based Nighttime AOT in the ADAM2 Model
No full textA data assimilation (DA) system employing day- and nighttime aerosol optical thickness (AOT) was developed for the Asian Dust Aerosol Model 2 (ADAM2), using the optimal interpolation (OI) method. The DA system assimilated nighttime AOT for dust retrieved from MODIS infrared (IR) measurements with an artificial neural network (ANN) approach. An Asian dust case that occurred during 14-18 March 2009 was simulated using ADAM2. To examine the impact of the inclusion of nighttime AOT on forecasts of the data assimilation system, experiments were performed with different assimilation cycles (i.e., DA1: 24-hour cycle with daytime MODIS AOT only, DA2: 12-hour cycle with additional nighttime AOT). A control simulation was also performed without data assimilation (CTL). Forecasts were assessed using MODIS-derived AOT distributions as well as ground-based skyradiometer, PM10, and lidar observations. The model-estimated vertical distribution of the dust extinction coefficient was also compared with lidar measurements. Both experiments (DA1, DA2) were found to have improved forecasting, but DA2 outperformed DA1. Results suggest that the ANN-based nighttime AOT contributes more positively to the forecasting through better temporal coverage for data assimilation.OAIID:RECH_ACHV_DSTSH_NO:T201725518RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A002329CITE_RATE:1.069DEPT_NM:지구환경과학부EMAIL:[email protected]_YN:YY
Stimulation of melanogenesis by scoparone in B16 melanoma cells
No full textAim: The effect of coumarin derivatives on melanogenesis was investigated in B16 murine melanoma cells. Methods: Melanin content and tyrosinase activity were analyzed spectrophotometrically. The expression of tyrosinase, tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2) were measured either by reverse transcription-polymerase chain reaction (RT-PCR) or Western blot. Results: Among the coumarin derivatives studied, scoparone (6,7-dimethoxycoumarin) was the most potent; the 6- or 7-methoxy group was found to be essential for the stimulation of melanogenesis. The melanin content was greatly increased by scoparone in a dose-dependent manner; there was no cytotoxicity at the effective concentrations. Scoparone increased enzyme activity as well as protein and mRNA expression of tyrosinase. In addition, mRNA of TRP-1 and TRP-2 were also increased after treatment with scoparone. H-89, an inhibitor of protein kinase A (PKA), completely inhibited the scoparone-induced increase of melanogenesis and the tyrosinase protein. Conclusion: These results suggest that scoparone-induced stimulation of melanogenesis is likely to occur at the transcriptional level of melanogenesis-related enzymes through PKA signaling.
Publisher Correction: Fusion guide RNAs for orthogonal gene manipulation with Cas9 and Cpf1
No full textThe originally published version of this Article contained an error in the spelling of the author Da-eun Kim, which was incorrectly given as Da-Eun Kim. Furthermore, in Figure 1a, the Cas9 protein was positioned incorrectly during typesetting. These errors have now been corrected in both the PDF and HTML versions of the Article.</jats:p
Interpretation and processing of overt pronouns in Korean, English and L2-acquisition
Get PDFThis dissertation investigates pronoun interpretation and processing of two languages (Korean and English), as well as in the second language (L2) acquisition of English by Korean speakers, with a focus on possible first language (L1) transfer. Using offline tasks and eye-tracking measures, the dissertation seeks answers to three primary research questions (RQs): 1) How are overt pronouns in Korean interpreted? 2) How are overt pronouns in Korean processed? 3) How do the properties of overt pronouns in Korean affect Korean-speaking English-learners’ interpretation and processing of English pronouns?
Experiment 1 examined RQ 1 by testing the interpretation of Korean sentences including the overt 3rd person pronoun kunye ‘she/her’ in Korean, using two offline tasks. The focus was on whether the bound variable readings as well as the coreferential readings are available with kunye by testing different antecedent types – referential antecedents (names) and quantificational antecedents (every NP) – and whether and how kunye can take a clause-mate antecedent violating Principle B (Pr B) of Binding Theory (Chomsky, 1981). The results showed that Korean native speakers allowed kunye construed as the referential antecedent regardless of whether the antecedent was in the same local domain with the pronoun or not. However, Korean native speakers showed asymmetrical judgments with kunye construed as the quantificational antecedent: they rejected kunye when it took the local quantificational antecedent while they allowed it when it took the long-distance (LD) quantificational antecedent. These results suggest two things. One is that both bound variable and coreferential readings are available with kunye and the bound variable reading of kunye is constrained by Pr B. The other is that the instances of Pr B violation can also be found robustly due to the availability of coreferential readings and the suspension of the rule specifying the context where the coreferential readings can surface over the bound variable readings (Rule I, proposed in Grodzinsky & Reinhart, 1993).
RQ 2 was addressed in Experiments 3 and 4 by examining whether and how Pr B is applied during the processing of the overt 3rd person pronoun in Korean, using eye-movement monitoring techniques while reading. More specifically, we tested if Korean speakers consider only the antecedents that are compatible with Pr B (i.e., LD antecedents) or they consider all the potential antecedents including the ones that are incompatible with Pr B (i.e., local antecedents) during the antecedent search process, by manipulating gender congruence between the pronoun and either of the two potential antecedents. We also tested if their processing pattern differs depending on the antecedent types (referential vs. quantificational). The results revealed the delayed gender incongruence effects with both antecedents, which indicates that both LD and local antecedents were activated during later stages of pronoun processing in Korean. The results also showed that there was no difference between the two antecedent types, which is unexpected. No ready explanation is present for why both antecedents are considered during parsing even with the bound variable reading of the overt pronoun (i.e., the pronoun with the quantificational antecedent), and hence future research should be conducted to follow up on this.
Experiments 2, 5 and 6 addressed RQ 3 by testing how Korean-speaking learners of English interpret and process English pronouns and by comparing their performance with English native speakers’ performance and with their own performance in corresponding Korean tasks from Experiments 1, 3 and 4. In Experiment 2, the native speakers exhibited categorical judgments with pronouns as locally bound antecedents vs. LD bound antecedents, regardless of whether they were referential or quantificational, which suggests that their interpretation of the pronouns obeyed Pr B. However, the L2 learners’ responses were not consistent with Pr B: they overaccepted the English pronoun with the local referential antecedent, as they did with kunye in Experiment 1. Based on this similarity, it was suggested that their primary use of the coreferential reading in Korean may be at work and hence affect their interpretation of English pronouns. Experiment 5 also provided suggestive evidence that the pronoun processing pattern in Korean may influence their pronoun processing pattern in English when the antecedent was the referential NP. It was based on the similarity of L2 learners’ processing patterns in English as well in Korean such that the L2 learners activated both LD and local antecedents in the antecedent retrieval process. Their pattern was different from that of English native speakers who established the dependency between the pronoun and the LD antecedents immediately after encountering the pronoun and considered the local antecedents too at later stages of parsing. Interestingly, in Experiment 6, no such parallelism of L2 learners’ processing patterns in English and in Korean was found when the antecedents were quantificational. Instead, their processing pattern was parallel to that of English native speakers, who applied Pr B early in their processing and considered only the LD antecedents subsequently. The lack of suggestive evidence for the L1-transfer effect with the quantificational antecedents may be attributed to the different role of Pr B with referential vs. quantificational antecedents or the unresolved puzzle regarding the processing of Korean overt pronouns with quantificational antecedents.
Taken together, these results indicate that coreferential reading of the overt pronoun in Korean is readily available due to the suspension of Rule I and it influences not only how the Korean overt pronoun is processed real-time but also how Korean-speaking learners of English interpret and process English pronouns. Implications are discussed in relation to the role of the L1 in L2 acquisition/processing, as well as the status of the overt 3rd person pronoun in Korean and the general sentence processing model available to a head-final language.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-12-01The student, Eun Hee Kim, accepted the attached license on 2019-06-25 at 08:22.The student, Eun Hee Kim, submitted this Dissertation for approval on 2019-06-25 at 08:34.This Dissertation was approved for publication on 2019-06-26 at 11:59.DSpace SAF Submission Ingestion Package generated from Vireo submission #14077 on 2020-02-28 at 17:34:52Made available in DSpace on 2020-03-02T22:28:38Z (GMT). No. of bitstreams: 7
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The Clinical and Thyroid Function Studies on Lymphocytic Thyroiditis with Spontaneously Resolving Hyperthyroidism : with Reference in Comparison to Subacute Thyroiditis
No full text의학과/석사[영문]
[한글]
자연관해성 갑상선 기능항진증을 동반한 임파구성 갑상선염(lymphocytic thyroiditis w
ith spontaneously resolving hyperthyroidism: LT-SRH) 은 임상 경과가 갑상선 동통과
발열이 없는 것 외에는 자연관해성 갑상선 기능항진증을 동반한 아급성 갑상선염 (subacu
te thyroiditis with spontaneously resolving hyperthyroidism: SAT-SRH)과 흡사하여 아
급성 갑상선염 (subacute thyroiditis: SAT)의 비정형적 형태로 보고되어 왔으나, 현재
자가면역성 갑상선염의 일종으로 밝혀지고 있다(Dorfman등, 1977: Nikolai등, 1980: Niko
lai등, 1981).
저자는 1979년 7월부터 1983년 6월까지 갑상선 종대 혹은 갑상선 기능항진증의 증세를
주소로 연세대학교 의과대학 부속 세브란스병원 내과에 내원하여 갑상선 방사성 옥소 섭
취율(RAIU)의 저하를 보인 35예중 LT-SRH 환자군 24예와 일관성 갑상선 기능항진증이 동
반된 8예를 포함한 SAT 환자군 11예로 나누어 임상적 고찰 및 갑상선기능에 관한 연구를
시행하여 다음과 같은 결과를 얻었다.
1. 연령별 발생빈도는 SAT 환자군에서는 30대 및 40대에 8예(73%)로 많았으나 LT-SRH
환자군에서는 20대에 15예(62.5%)로 많았는데 이중 12예에서 분만후 발생을 관찰하였다.
성비는 SAT 환자군에서는 1예의 남자환자를 제외하고 모두 여자였으며 LT-SRH 환자는 전
예가 여자였다.
2. 최근 분만한 환자는 SAT 환자군중에는 1예도 없었으나 LT-SRH 환자군에서는 14예(58
.3%)가 분만후 발병하였으며 85.6%의 환자가 분만후 1 내지 4개월내에 발병과 함께 내원
하는 것을 관찰하였다.
3. 내원당시 주소는 SAT 환자군에서는 발열(100%), 동통성 갑상선비대 (63.6%), 전경부
동통(27.3%)의 순으로 많았고, LT-SRH 환자군에서는 무통성 갑상선 종대(83.3%), 심계항
진(20.8%), 두통(8.4%)의 순으로 많았다.
4. 말초혈액 총 백혈구수는 양 질환 모두 의의있는 증가가 없었으나 적혈구 침강속도는
SAT-SRH 환자군에서 39±4mm/h, LT-SRH 환자군에서 18±3mm/h로 전자에서 20이상으로 증
가되어 있는 것을 관찰하였다.
5. 초진시의 혈청 갑상선 호르몬치는 SAT-SRH 및 LT-SRH 환자군에서 증가되어 있었으며
, LT-SRH 환자군의 혈청 T3 치가 SAT-SRH 환자군에 비해 의의있게 높았다(P<0.05). T3/T4
(ng/㎍)율은 양 질환 모두 20미만치를 보였다.
6. 갑상선 자가항체는 SAT 환자군에서는 1예만이 저항체가(1:10**2)에서 항 - microsom
e 항체 양성을 보였으나 LT-SRH 환자군에서는 17예(70.8%)에서 항 - microsome 항체 양성
을 보였으며 이중 9예(37.5%)가 항 - thyroglobulin 항체에도 양성반응을 보였다.
7. LT-SRH 환자 4예에서 세침 흡인천자 세포검사상 다수의 임파구를 관찰하였다.
8. LT-SRH 환자군에서 갑상선기능을 반복 검사하여 8내지 12개월내에 혈청 갑상선 호르
몬치가 정상으로 떨어지는 것을 관찰하였으며 2내지 4개월후 관찰한 11예중 6예에서 갑상
선 기능저하 소견을 보였다.
LT-SRH와 SAT는 임상소견, 최근 분만여부 및 갑상선 자가항체의 양성반응등으로 쉽게
감별할 수 있으며, LT-SRH는 갑상선 자가항체의 양성반응과 갑상선 세포검사상 임파구 침
윤소견등으로 일종의 자가면역성 갑상선염으로 간주할 수 있을 것으로 생각된다.
The Clinical and Thyroid Function Studies on Lymphocytic Thyroiditis with
Spontaneously Resolving Hyperthyroidism: with Reference in Comparison to Subacute
Thyroiditis
Eun Hee Koh
Department of Medical Science The Graduate School Yonsei University
(Directed by Prof. Kap Bum Huh)
Lymphocytic thyroiditis with spontaneously resolving hyperthyroidism(LT-SRH) may
be defined as transient hyperthyroidism with low radioactive iodine uptake(RAIU)
and painless goiter.
The clinical course of LT-SRH is similar to subacute thyroiditis with
spontaneously resolving hyperthyroidism(SAT-SRH) except painless thyroid and
absence of fever. It had been reported as atypical from of subacute
thyroiditis(SAT), but it is known as autoimmune thyroiditis on the basis of
positive anti-thyroid antibody and diffuse lymphocytic infiltration of thyroid
gland at present time.
The author observed clinical manifestations and thyroid functions from 35
patients with chief complaints of thyroid enlargement with or without pain or
symptoms of hyperthyroidism with decreased RAIU.
The following results were obtained.
1. Twenty four patients(68.6%) were LT-SRH and Ⅱ1 patients(31.4%) were SAT.
Eight of Ⅱ patients had transient hyperthyroidism.
2. The peak age incidence was 4th and 5th decades(73%) in SAT, 3rd decade(62.5%)
in LT-SRH. Except one in SAT, all of patients were females.
3. LT-SRH developed after delivery in 14 patients(58.3%) of 24 patients.
4. The chief complaints of patients on the first visit were painless goiter,
palpitation and headache in LT-SRH, and fever, painful thyroid enlargement,
anterior neck pain in SAT in order of frequency.
5. Although peripheral leukocytes counts showed no significant difference between
two diseases, ESR was significantly increased in SAT.
6. Although serum T3 values was significantly higher in LT-SRH than SAT-SRH, the
results of serum T4, FT4, TSH and thyroid RAIU tests showed no significant
differences between two diseases on first visit. Mean T3/T4(ng/㎍) ratios were
below 20 in both diseases.
7. Although only one patients(12.5%) in SAT had positive antimicrosomal antibody
in low titer, 70.8% of LT-SRH patients had positive anti-microsomal antibody in
relatively high titers.
8. Numerous lymphocytes were observed on thyroid aspiration cytology smear by
fine needle aspiration in 4 patients with LT-SRH.
9. The thyroid functions of LT-SRH patients returned to normal within 8 to 12
months after the first visit.
From the above results, it is considered that LT-SRH might be an autoimmune
thyroiditis with spontaneously resolving hyperthyroidism which showed high
prevalence after delivery.
The clinical features, ESR, anti-thyroid antibody test and thyroid aspiration
cytology would help to differentiate LT-SRH from SAT and RAIU determination is very
important in differential diagnosis from Graves' disease.restrictio
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