• 대한기계학회논문집
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• 제19권3호
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• pp.846-857
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• 1995

An experimental study is made of turbulent shear flows in a nearly two-dimensional 90.deg. curved duct by using the hot-wire anemometer. The Reynolds normal and shear stresses, triple velocity products, integral length scales, Taylor micro length scales and dissipation length scales are measured and analyzed. For a positive shear at the inlet, the afore-mentioned turbulence quantities are all suppressed. However, when the inlet shear flow is negative, they are augmented, i.e., the convex curvature suppresses the turbulence whereas the concave curvature augments it. It is found that the curvature effects are rather sensitive to the triple velocity products than the Reynolds stresses. The evolution of turbulence under the curvature with the different shear conditions is well described by the modified curvature parameter S' and the non-dimensional development time ${\tau}$.'

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1583-1591
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• 2020

CRISPR/Cpf1 has emerged as a new CRISPR-based genome editing tool because, in comparison with CRIPSR/Cas9, it has a different T-rich PAM sequence to expand the target DNA sequence. Single-base editing in the microbial genome can be facilitated by oligonucleotide-directed mutagenesis (ODM) followed by negative selection with the CRISPR/Cpf1 system. However, single point mutations aided by Cpf1 negative selection have been rarely reported in Corynebacterium glutamicum. This study aimed to introduce an amber stop codon in crtEb encoding lycopene hydratase, through ODM and Cpf1-mediated negative selection; deficiency of this enzyme causes pink coloration due to lycopene accumulation in C. glutamicum. Consequently, on using double-, triple-, and quadruple-base-mutagenic oligonucleotides, 91.5-95.3% pink cells were obtained among the total live C. glutamicum cells. However, among the negatively selected live cells, 0.6% pink cells were obtained using single-base-mutagenic oligonucleotides, indicating that very few single-base mutations were introduced, possibly owing to mismatch tolerance. This led to the consideration of various target-mismatched crRNAs to prevent the death of single-base-edited cells. Consequently, we obtained 99.7% pink colonies after CRISPR/Cpf1-mediated negative selection using an appropriate single-mismatched crRNA. Furthermore, Sanger sequencing revealed that single-base mutations were successfully edited in the 99.7% of pink cells, while only two of nine among 0.6% of pink cells were correctly edited. The results indicate that the target-mismatched Cpf1 negative selection can assist in efficient and accurate single-base genome editing methods in C. glutamicum.

• 대한임상검사과학회지
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• 제53권1호
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• pp.41-48
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• 2021

Essential thrombocythemia (ET) is a clonal bone marrow stem cell disorder, primarily involving the megakaryocytic lineage. The WHO 2016 guidelines include the molecular detection of JAK2, MPL, and CALR mutations as a major diagnostic criterion for ET. This study aimed to determine the frequency of JAK2 V617F, MPL W515L, and CALR mutations in Iraqi Kurdish patients afflicted with ET, and to analyze their clinical and hematological features. A total of 73 Iraqi Kurdish patients with ET were enrolled as subjects, and analysis was achieved utilizing real-time PCR. The frequency of JAK2 V617F, CALR, and MPL W515L mutations was determined to be 50.7%, 22%, and 16.4%, respectively. No statistically significant difference was obtained when considering the age and gender among different genotypes. The JAK2 V617F mutated patients had significantly higher white blood cell counts and hemoglobin levels than the CALR-positive patients (P-value=0.000, 0.007, respectively), MPL W515L-positive patients (P-value=0.000, 0.000, respectively), and triple negative patients (P-value=0.000, 0.000, respectively). Also, the JAK2 V617F mutated patients showed higher platelet count as compared to the MPL W515L-positive patients (P-value=0.02) and triple negative patients (P-value=0.04). Furthermore, significantly lower white blood cell count and hemoglobin levels were associated with CALR positivity (P-value=0.000, 0.01, respectively), MPL W515L-positivity (P-value=0.001, 0.000, respectively), and triple negativity (P-value=0.000, 0.000, respectively), as compared to patients with combined mutations. In conclusion, apart from a relatively high frequency of MPL W515L mutation, our data is comparable to earlier reports, and highlights the importance of genotyping the JAK2 V617F, MPL W515L, and CALR mutations for accurate diagnosis of patients with ET.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6443-6447
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• 2014

Background: To determine the predictive value of the baseline stimulated thyroglobulin (STg) level for ablation outcome in patients undergoing adjuvant remnant radioiodine ablation (RRA) for differentiated thyroid carcinoma (DTC). Materials and Methods: This retrospective study accrued 64 patients (23 male and 41 female; mean age of $40{\pm}14$ years) who had total thyroidectomy followed by RRA for DTC from January 2012 till April 2014. Patients with positive anti-Tg antibodies and distant metastasis on post-ablative whole body iodine scans (TWBIS) were excluded. Baseline STg was used to predict successful ablation (follow-up STg <2 ng/ml, negative diagnostic WBIS and negative ultrasound neck) at 7-12 months follow-up. Results: Overall, successful ablation was noted in 37 (58%) patients while ablation failed in 27 (42%). Using the ROC curve, a cut-off level of baseline STg level of ${\leq}14.5ng/ml$ was found to be most sensitive and specific for predicting successful ablation. Successful ablation was thus noted in 25/28 (89%) of patients with baseline STg ${\leq}14.5ng/ml$ and 12/36 (33%) patients with baseline STg >14.5 ng/ml ((p value <0.05). Age >40 years, female gender, PTS >2 cm, papillary histopathology, positive cervical nodes and positive TWBIS were significant predictors of ablation failure. Conclusions: We conclude that in patients with total thyroidectomy followed by I-131 ablation for DTC, the baseline STg level is a good predictor of successful ablation based on a stringent triple negative criteria (i.e. follow-up STg < 2 ng/ml, a negative DWBIS and a negative US neck).

• 미생물학회지
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• 제44권4호
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• pp.339-345
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• 2008

국내 대학병원에서 분리되어 imipenem 에 대한 최소억제농도가 $8{\mu}g/ml$ 이상인 51개의 포도당비발효 그람음성 간균들 중 metallo-${\beta}$-lactamase (MBL)을 생성하는 균주들을 분리하고, 그들 중에서 내성이 강한 Pseudomonas aeruginosa에 대한 항균제 병합요법의 효과를 알아보기 위하여 상승효과를 보이는 항균제 조합을 찾아보았다. 9개의 균주(Pseudomonas aeruginosa 2주 및 Achromobacter xylosoxidans subsp. xylosoxidans 7주)가 MBL 양성을 나타냈으며, PCR 결과 9주 모두에서 $bla_{VIM-2}$ 유전자가 관찰되었다. 이들 중에서 P. aeruginosa DK569는 aztreonam (MIC; $8{\mu}g/ml$)을 제외하고 실험한 모든 ${\beta}$-lactam 항균제, aminoglycoside, ciprofloxacin에 내성을 보여 aztreonam 함유 배지를 이용하여 상승효과률 보이는 항균제를 찾고자 하였다. One disk synergy test 에서 선별된 항균제 조합을 이용하여 생존률 검사 실험을 한 결과, aztreonam (AZT)와 piperacillin-tazobactam (TZP)의 병합은 항균제 노출 6시간 후에 AZT 또는 TZP의 단독 항균제 노출시 보다 균수가 1/18.7로 감소하였다. 그리고 AZT와 amikacin (AN)의 병합에서도 항균제 노출 6 시간 후에 AZT 또는 AN의 단독항균제의 투여보다 균수가 1/17.1 로 감소하였다. 결국 위 두 조합은 의미있는 상승효과를 보이지 못하여 위 세 항균제를 조합하여 실험하였다. 위의 세 항균제를 병합하였을 때 항균제 노출 8시간 후에 AZT, TZP 및 AN의 단독 투여에 비하여 병합요법에 의해 균수가 1/183.3 로 감소하여 의미있는 상승효과를 보였다. 이 결과는 치료가 쉽지 앓은 MBL 생성균에 의한 감염에 대한 치료에 AZT, TZP 및 AN의 세 가지 항균제 병합요법이 유용할 것이라는 것을 의미한다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4445-4452
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• 2012

Background: Prognosis of breast cancer depends on classic pathological factors and also tumor angiogenesis. This study aimed to evaluate the clinicopathological factors of breast cancer in a tertiary centre with a focus on the relationship between tumor angiogenesis and clinicopathological factors. Methods: Clinicopathological data were retrieved from the archived formal pathology reports for surgical specimens diagnosed as invasive ductal carcinoma, NOS. Microvessels were immunohistochemically stained with anti-CD34 antibody and quantified as microvessel density. Results: At least 50% of 94 cases of invasive breast ductal carcinoma in the study were advanced stage. The majority had poor prognosis factors such as tumor size larger than 50mm (48.9%), positive lymph node metastasis (60.6%), and tumor grade III (52.1%). Higher percentages of estrogen and progesterone receptor negative cases were recorded (46.8% and 46.8% respectively). Her-2 overexpression cases and triple negative breast cancers constituted 24.5% and 22.3% respectively. Significantly higher microvessel density was observed in the younger patient age group (p=0.012). There were no significant associations between microvessel density and other clinicopathological factors (p>0.05). Conclusions: Majority of the breast cancer patients of this institution had advanced stage disease with poorer prognostic factors as compared to other local and western studies. Breast cancer in younger patients might be more proangiogenic.

• Communications for Statistical Applications and Methods
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• 제5권2호
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• pp.539-557
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• 1998

This article is concerned with the problem of estimating the mean of a one-parameter exponential family through sequential sampling in three stages under quadratic error loss. This more general framework differs from those considered by Hall (1981) and others. The differences are : (i) the estimator and the final stage sample size are dependent; and (ii) second order approximation of a continuously differentiable function of the final stage sample size permits evaluation of the asymptotic regret through higher order moments. In particular, the asymptotic regret can be expressed as a function of both the skewness $\rho$ and the kurtosis $\beta$ of the underlying distribution. The conditions on $\rho$ and $\beta$ for which negative regret is expected are discussed. Further results concerning the stopping variable N are also presented. We also supplement our theoretical findings wish simulation results to provide a feel for the triple sampling procedure presented in this study.

• 한국동물위생학회지
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• 제21권2호
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• pp.107-115
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• 1998

In order to establish a rapid, sensitive and specific diagnostic method for detection of antibody to Brucella abortus, a enzyme-linked immunosorbent assay(ELISA) was adapted. The diagnostic efficacy of the established ELISA was compared with that of the standard tube agglutination test for B abortus. 1. It was found that the optimal concentration of antigen for this ELISA was 5$\mu\textrm{g}$/ml, the optimal dilution of conjugate was 1 : 2000, and the optimal dilution of serum was 1 : 200, respectively. 2. Cut off value in this ELISA was 1,102 that was determined by mean absorbance(at 492nm) of tube agglutination test negative serum added with the triple value of the standared devation. 3. The relationship between the tube agglutination test and ELISA was showen high corresponding rate with sensitivity(96.3%) and specificity(98.1%). 4. The efficacy of the ELISA for detection of B abortus antibody was compared with tube agglutination test In brucellosis outbreak farm. The sensivity of ELSIA was higher than tube agglutination test.

• Journal of Contemporary Eastern Asia
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• 제12권1호
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• pp.81-93
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• 2013

Over the past several decades, educational systems in many parts of the world have undergone manifold changes that have significantly affected the work environment of educators. Among other negative impacts of the globalized reforms in higher education has been the increasing prevalence of workplace bullying. The purpose of this research note is to serve different purposes: (1) examine the causes behind the changing landscape of higher education; (2) discuss previous and current research on workplace bullying; (3) introduce the methodology of the Taiwan Higher Education Faculty Survey (THEFS); (4) outline its anticipated outcome.

• 한국동물위생학회지
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• 제23권3호
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• pp.289-299
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• 2000

The study was performed to investigate the distributions of swine pleuropneumonia in Kyongbuk western area by the enzyme-linked immunosorbent assay (ELISA). Sera collected from 400 slaughtered pigs in 3 slaughter houses during the period from May 1999 to october 1999 were tested to detect antibodies against A pleuropneumonie serotype 2 and 5. The optimal dilution of CBE antigen, conjugate and serum for this ELISA were determined 1 : 400, 1 : 20,000, 1 100, respectively. The optimal dilution of OW antigen, conjugate and serum for this ELISA were determined 1 : In, 1 : 20,000, 1 : 200, respectively. Cut-off value in this ELISA was determined by mean absorbance (at 492 nm) of negative control sera added with the triple value of the standard deviation. Cut-off value in ELISA by CBE and OMP antigen were 1.134 and 1.217, respectively. By the ELISA, positive reaction rates to A pleuropneumoniae serotype 2 and 5 for CBE antigen were 38.8% and 18.8%, and for OMP antigen were 42.8% and 23.5% of the 400 samples, respectively.