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Bifactor 다차원 문항반응이론을 적용한 단위검사 구성 검사점수의 신뢰도 추정 방법
김나나(Nana Kim):이규민(Guemin Lee):강상진(Sang-Jin Kang) 한국교육평가학회 2017 교육평가연구 Vol.30 No.1
이 연구에서는 bifactor 다차원 문항반응이론을 적용하여 단위검사 구성 검사점수의 신뢰도를 추정하였고, 이를 기존 연구에서 사용되어온 다른 신뢰도 추정 방법들과 비교하였다. 구체적으로 bifactor 모형, 일차원 이분문항반응이론 모형, 일차원 다분문항반응이론 모형을 적용하여 추정한 신뢰도를 비교하였으며, 단위검사 효과의 크기와 단위검사의 불균형 수준이 이러한 단위검사 구성 검사점수의 신뢰도 추정에 미치는 영향을 분석하였다. 연구 결과, bifactor 모형이 단위검사 구성 검사점수의 신뢰도를 가장 정확하게 추정하였고, 이분문항반응이론 모형과 다분문항반응이론 모형은 신뢰도를 각각 과대 추정하거나 과소 추정하였다. 하지만 다분문항반응이론 모형의 경우에는 신뢰도 과소 추정의 정도가 미미하여, 단위검사 구성 검사점수의 신뢰도를 추정하는 방법으로 사용할 수 있을 것으로 보인다. 또한 단위검사의 효과가 커질수록 이분문항반응이론 모형의 신뢰도 과대 추정 정도가 커지는 것으로 나타난 반면, 단위검사의 불균형 수준은 신뢰도 추정에 큰 영향을 미치지 않았다. This study aimed to investigate a bifactor MIRT approach to estimating the reliability of testlet-composed test scores. Using simulated data, the reliability estimates derived from a bifactor model were compared to those estimated via traditional IRT models: a two parameter logistic (2PL) model and a graded response model (GRM). Moreover, the effects of testlet effect size and the degree of imbalance in testlet lengths on estimating the reliability were examined. The bifactor model produced the most accurate reliability estimates of testlet-composed test scores while the 2PL model and GRM over- and under-estimated the reliability, respectively. The magnitudes of underestimation in the GRM, however, were very small; therefore, using the GRM also seemed to be quite appropriate when estimating the reliability of testlet-composed test scores. The errors of reliability estimates obtained from the 2PL model increased as the testlet effect grew larger. The degree of imbalance in testlet lengths also influenced the errors of reliability estimated from the 2PL model, but the effect was marginal
Practical Synthesis of 1,1-Difluoro- or 1-Fluoroalkenes from 2,2,2-Trifluoroacetophenone Derivatives
Minhyuk Kang,Sun-Ah Lee,Nana Kang,문봉진 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.8
Since the discovery of the fact that compounds bearing a vinylic fluoride moiety often exhibit remarkable biological activities such as enzyme inhibitors, many synthetic methods for fluorine-substituted vinylic compounds have been developed. The synthesis of selectively fluorinated building blocks, such as arylsubstituted fluoro-alkenes, also has become an area of interest in recent years. Herein we describe a novel and practical method for the synthesis of 1,1-difluoro- and 1-fluoroalkenes starting from easily accessible trifluoroacetophenone derivatives. Various 1,1-difluoro- and 1-fluoroalkenes were prepared by the reaction of the corresponding tosyl hydrazones that were derived from trifluoroacetophenone derivatives by treating with alkyl or aryllithium reagents via addition-elimination and single electron transfer (SET) mechanism.
Upper Extremity Deep Vein Thrombosis After Botulinum Toxin Injection: A Case Report
Lim Nana,Lee Geun Su,Won Ki Hong,Kang Jin Sun,Lee Sung Hoon,Kang Eun Young,Lee Hyun Kyung,Cho Youn Kyung 대한재활의학회 2021 Annals of Rehabilitation Medicine Vol.45 No.2
Botulinum toxin (BoNT) injection is widely used to improve spasticity. However, after the treatment, the patient may experience pain, inflammation, swelling and redness at the injection site. In this case, we addressed deep vein thrombosis (DVT) after BoNT treatment of the upper limb. A male aged 37 years had spasticity and dystonia in his left upper extremity. BoNT-A 100 U was injected into the left biceps brachii and an equal amount into the brachialis to relieve spasticity. After three days, he developed redness and painful swelling in the left upper arm and the next day, through the upper extremity computed tomography venography, DVT was identified in the left cephalic vein. The thrombus resolved after the anticoagulation therapy with rivaroxaban (Xarelto). We hypothesized the role of mainly three mechanisms in the development of DVT in this case: repetitive strenuous activity, relative stasis due to reduced muscle tone, and possible direct mechanical damage to the vessel wall.
MRPrimerV: a database of PCR primers for RNA virus detection
Kim, Hyerin,Kang, NaNa,An, KyuHyeon,Kim, Doyun,Koo, JaeHyung,Kim, Min-Soo Oxford University Press 2017 Nucleic acids research Vol.45 No.d1
<P>Many infectious diseases are caused by viral infections, and in particular by RNA viruses such as MERS, Ebola and Zika. To understand viral disease, detection and identification of these viruses are essential. Although PCR is widely used for rapid virus identification due to its low cost and high sensitivity and specificity, very few online database resources have compiled PCR primers for RNA viruses. To effectively detect viruses, the MRPrimerV database (http://MRPrimerV.com) contains 152 380 247 PCR primer pairs for detection of 1818 viruses, covering 7144 coding sequences (CDSs), representing 100% of the RNA viruses in the most up-to-date NCBI RefSeq database. Due to rigorous similarity testing against all human and viral sequences, every primer in MRPrimerV is highly target-specific. Because MRPrimerV ranks CDSs by the penalty scores of their best primer, users need only use the first primer pair for a single-phase PCR or the first two primer pairs for two-phase PCR. Moreover, MRPrimerV provides the list of genome neighbors that can be detected using each primer pair, covering 22 192 variants of 532 RefSeq RNA viruses. We believe that the public availability of MRPrimerV will facilitate viral metagenomics studies aimed at evaluating the variability of viruses, as well as other scientific tasks.</P>
Kim, Hyerin,Kang, NaNa,An, KyuHyeon,Koo, JaeHyung,Kim, Min-Soo Oxford University Press 2016 Nucleic acids research Vol.44 No.w1
<P>Design of high-quality primers for multiple target sequences is essential for qPCR experiments, but is challenging due to the need to consider both homology tests on off-target sequences and the same stringent filtering constraints on the primers. Existing web servers for primer design have major drawbacks, including requiring the use of BLAST-like tools for homology tests, lack of support for ranking of primers, TaqMan probes and simultaneous design of primers against multiple targets. Due to the large-scale computational overhead, the few web servers supporting homology tests use heuristic approaches or perform homology tests within a limited scope. Here, we describe the MRPrimerW, which performs complete homology testing, supports batch design of primers for multi-target qPCR experiments, supports design of TaqMan probes and ranks the resulting primers to return the top-1 best primers to the user. To ensure high accuracy, we adopted the core algorithm of a previously reported MapReduce-based method, MRPrimer, but completely redesigned it to allow users to receive query results quickly in a web interface, without requiring a MapReduce cluster or a long computation. MRPrimerW provides primer design services and a complete set of 341 963 135 <I>in silico</I> validated primers covering 99% of human and mouse genes. Free access: http://MRPrimerW.com.</P>
( Jaehyung Koo ),( Sen Wang ),( Nana Kang ),( Sun Jin Hur ),( Young Yil Bahk ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.7
Ras oncoproteins are small molecular weight GTPases known for their involvement in oncogenesis, which operate in a complex signaling network with multiple effectors. Approximately 25% of human tumors possess mutations in a member of this family. The Raf1/MEK/Erk1/2 pathway is one of the most intensively studied signaling mechanisms. Different levels of regulation account for the inactivation of MAP kinases by MAPK phosphatases in a cell type- and stimuli-dependent manner. In the present study, using three inducible Ras-expressing NIH/3T3 cell lines, we demonstrated that MKP3 upregulation requires the activation of the Erk1/2 pathway, which correlates with the shutdown of this pathway. We also demonstrated, by applying pharmacological inhibitors and effector mutants of Ras, that induction of MKP3 at the protein level is positively regulated by the oncogenic Ras/Raf/MEK/Erk1/2 signaling pathway. [BMB Reports 2016; 49(7): 370-375]