http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
Kim, Heon Seok,Lee, Kyungjin,Bae, Sangsu,Park, Jeongbin,Lee, Chong-Kyo,Kim, Meehyein,Kim, Eunji,Kim, Minju,Kim, Seokjoong,Kim, Chonsaeng,Kim, Jin-Soo American Society for Biochemistry and Molecular Bi 2017 The Journal of biological chemistry Vol.292 No.25
<P>Several groups have used genome-wide libraries of lentiviruses encoding small guide RNAs (sgRNAs) for genetic screens. In most cases, sgRNA expression cassettes are integrated into cells by using lentiviruses, and target genes are statistically estimated by the readout of sgRNA sequences after targeted sequencing. We present a new virus-free method for human gene knockout screens using a genome-wide library of CRISPR/Cas9 sgRNAs based on plasmids and target gene identification via whole-genome sequencing (WGS) confirmation of authentic mutations rather than statistical estimation through targeted amplicon sequencing. We used 30,840 pairs of individually synthesized oligonucleotides to construct the genome-scale sgRNA library, collectively targeting 10,280 human genes (<I>i.e.</I> three sgRNAs per gene). These plasmid libraries were co-transfected with a Cas9-expression plasmid into human cells, which were then treated with cytotoxic drugs or viruses. Only cells lacking key factors essential for cytotoxic drug metabolism or viral infection were able to survive. Genomic DNA isolated from cells that survived these challenges was subjected to WGS to directly identify CRISPR/Cas9-mediated causal mutations essential for cell survival. With this approach, we were able to identify known and novel genes essential for viral infection in human cells. We propose that genome-wide sgRNA screens based on plasmids coupled with WGS are powerful tools for forward genetics studies and drug target discovery.</P>
Kim, Heon Seok,Lee, Kyungjin,Kim, Seong-Jun,Cho, Sungchan,Shin, Hye Jin,Kim, Chonsaeng,Kim, Jin-Soo Cold Spring Harbor Laboratory Press 2018 Genome research Vol.28 No.6
<P>Pooled CRISPR screens based on lentiviral systems have been widely applied to identify the effect of gene knockout on cellular phenotype. Although many screens were successful, they also have the limitation that genes conferring mild phenotypes or those essential for growth can be overlooked, as every genetic perturbation is incorporated in the same population. Arrayed screens, on the other hand, incorporate a single genetic perturbation in each well and could overcome these limitations. However, arrayed screens based on siRNA-mediated knockdown were recently criticized for low reproducibility caused by incomplete inhibition of gene expression. To overcome these limitations, we developed a novel arrayed CRISPR screen based on a plasmid library expressing a single guide RNA (sgRNA) and disrupted 1514 genes, encoding kinases, proteins related to endocytosis, and Golgi-localized proteins, individually using 4542 sgRNAs (three sgRNAs per gene). This screen revealed host factors required for infection by coxsackievirus B3 (CVB3) from Picornaviridae, which includes human pathogens causing diverse diseases. Many host factors that had been overlooked in a conventional pooled screen were identified for CVB3 infection, including entry-related factors, translational initiation factors, and several replication factors with different functions, demonstrating the advantage of the arrayed screen. This screen was quite reliable and reproducible, as most genes identified in the primary screen were confirmed in secondary screens. Moreover, ACBD3, whose phenotype was not affected by siRNA-mediated knockdown, was reliably identified. We propose that arrayed CRISPR screens based on sgRNA plasmid libraries are powerful tools for arrayed genetic screening and applicable to larger-scale screens.</P>
CSCL 에서 의사결정 유형과 협력적 정보처리지원 수준이 협력성과, 협력구성원 간의 사회적지지도 및 협력부하에 미치는 영향
김경진(Kyungjin Kim),김동식(Dongsik Kim),김경(Kyung Kim) 한양대학교 교육공학연구소 2014 학습과학연구 Vol.8 No.3
본 연구는 효과적인 협력성과를 위한 정보처리과정을 제안하고 특히 학습자의 의사결정 유형에 따른 최적의 정보처리 과정을 제공하고자 한다. 이 연구의 목적은 학습자의 의사결정 유형에 따른 협력적정보처리지원 수준의 효과를 검증하기 위한 것으로 협력성과, 협력구성원 간의 사회적지지도, 협력부하요인에 대한 차이검증을 실시하였다. 연구 대상은 대학생 111명(남 32명, 여 79명)이었으며, 세 종류의 협력적정보처리지원 수준을 동일 학습내용에 대하여 제시하였다. 사전검사에 의하여 의존적의사결정 집단과 합리적의사결정 집단으로 구분하였다. 연구에 투입된 협력성과, 협력구성원 간의 사회적지지도, 협력부하 요인의 세 종속변수에 대하여 협력적정보처리지원 수준과 의사결정유형에 의한 주효과는 유의미하지 않았다. 그러나 세 종속변수에서 학습자의 의사결정 유형과 협력적정보처리지원 수준에 의한 상호작용은 유의미했다. 이 결과는 학습자의 의사결정 유형에 의한 매개효과가 있음을 의미한다. 협력성과에서 병렬 및 직렬정보처리지원에서는 학습자의 의사결정유형에 따른 차이가 없었다. 그러나 혼합정보처리지원에서는 의사결정유형에 따른 사후검사 결과가 달라지는 것으로 나타났다. 협력부하요인 중 과제난이도 지각에서 유의미한 상호작용이 발견되었고, 분석결과 단순주효과에 따르면 직렬정보처리지원에 있던 의존적의사결정 집단의 과제난이도 지각이 현저히 낮게 나타났다. 또한 협력구성원 간의 사회적지지도에 대한 분석에서는 직렬정보처리지원의 합리적의사결정 수준인 학습자의 협력구성원 간의 사회적지지도가 가장 낮은 것으로 나타났다. 비록 협력구성원 간의 낮은 사회적지지도에 의해 협력성과가 영향을 받은 것은 아니라 할지라도 학습 효율성이 낮아질 가능성을 배제하기는 어렵다. 이러한 연구결과를 토대로 협력학습전략을 도출하기 위해서는 정보처리지원 수준이나 학습자 개인의 의사결정유형과 같은 보다 복잡한 구성요인을 고려해야 할 것이다. The purpose of this study was to identify the effects of decision-making and collaborative information processing on performance and collaborative task performance, social support among collaborators. College students(Male=32, Female=79) participated. Three different collaborative information processing were applied(mixing vs. serial vs. parallel) to two different levels(dependent group vs intuitive group) of participants depending on their pre-test result. The dependent variables were collaboration performance, social support among collaborators and collaboration load. The result revealed that there was a significant interaction effect on posttest score for collaboration performance. Students under collaborative information processing condition showed no difference between levels of decision-making. However, there was significant difference between levels of decision-making under collaborative information processing condition. Also simple-main effect analysis showed that participants of dependent group under parallel processing condition significantly perceived task difficulty among the other condition. For the social support among collaborators, interestingly, participant of dependent group with parallel condition showed significantly higher social support. This result indicated that there possibly detrimental effect of decision-making.
김경진(Kyungjin Kim),김병성(Byungsung Kim),원장원(Changwon Won),최현림(Hyunrim Choi),김선영(Sunyoung Kim),박우철(Woochul Park),권은중(Eunjoong Kwon) 대한스트레스학회 2017 스트레스硏究 Vol.25 No.2
청소년기의 심리적 발달에는 환경의 역할이 중요하게 여겨져 왔으며, 그 중 형제자매의 역할과 출생순서가 큰 영향을 미칠 것이라 생각되어 왔다. 본 연구는 10차(2014년) 청소년건강행태온라인조사 통계 자료를 이용하여 우리나라 청소년의 출생순서에 따른 신체활동, 스트레스 정도와의 연관성을 알아보는 것을 목적으로 수행되었다. 첫째군보다 둘째이하군에서 더 많은 신체활동을 하였으며 자신이 경제적으로 낮은 위치에 있고 학업 성적이 좋지 않았으며 음주경험과 흡연경험 또한 높았다. 그러나 다변량회귀분석 결과 둘째이하군에서 스트레스나 자살시도가 높지 않았다. 청소년시기에 가정과 학교에서 출생순서에 따라 스트레스 관리전략을 차별화한 중재연구가 필요할 것이다. Backgound: A number of studies have documented relationship between various individual outcomes and birth order. This study sought to investigate the relationship between adolescents health behavior, stress and birth order. Methods: The data used in this study were obtained middle and high school students who replied to the 10th Korea Youth Risk Behavior Web-based Survey (KYRBWS) administered in 2014. We investigated the associations between health behavior, stress and birth order using multivariable logistic regression analysis controlling with age, height, weight, father’s education, mother’s education, economic status, academic status, sleep duration, sitting time, self-perceived health status, self-perceived happiness, depression mood, suicide idea, suicide plan, suicide attempt, drinking experience, smoking experience. Results: The distribution of first-born was 45.5% and later-born was 54.5%. In multivariable logistic regression the later-born replied higher portion of vigorous physical activity 3 days per week and strength exercise 5 days per week. And later-born replied lower economic status, lower academic performance and higher prevalence of drinking experience, smoking experience. Later-born they had more stress than first-born, but after adjusted for variable factors in multivariable logistic regression, birth order had no relationship with stress significantly. Conclusions: This study offers data for the development of intervention programs to adolescent related to birth order, and further study is necessary in order to clarify adolescent’s relationship between birth order and stress and individual outcomes.
Moon, Younghye,Kim, Joo Yeon,Kim, Woon Ryoung,Kim, Hyun Jung,Jang, Min Jee,Nam, Yoonkey,Kim, Kyungjin,Kim, Hyun,Sun, Woong AlphaMed Press 2013 Stem cells Vol.31 No.8
<P>Throughout life, newly generated neuroblasts from the subventricular zone migrate toward the olfactory bulb through the rostral migratory stream. Upon brain injury, these migrating neuroblasts change their route and begin to migrate toward injured regions, which is one of the regenerative responses after brain damage. This injury-induced migration is triggered by stromal cell-derived factor 1 (SDF1) released from microglia near the damaged site; however, it is still unclear how these cells transduce SDF1 signals and change their direction. In this study, we found that SDF1 promotes the phosphorylation of ezrin-radixin-moesin (ERM) proteins, which are key molecules in organizing cell membrane and linking signals from the extracellular environment to the intracellular actin cytoskeleton. Blockade of ERM activation by overexpressing dominant-negative ERM (DN-ERM) efficiently perturbed the migration of neuroblasts. Considering that DN-ERM-expressing neuroblasts failed to maintain proper migratory cell morphology, it appears that ERM-dependent regulation of cell shape is required for the efficient migration of neuroblasts. These results suggest that ERM activation is an important step in the directional migration of neuroblasts in response to SDF1-CXCR4 signaling following brain injury.</P>