• 대한화학회지
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• 제13권3호
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• pp.221-228
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• 1969

Nucleophile의 親核性 添加反應性을 정량적으로 연구하고자 전보에 이어 3,4-methylenedioxy-${\beta}$-nitrostyrene에 대한 n-amyl, n-hexyl, n-Octyl, n-decylamercaptanㅓ의 添加反應速度常數를 측정한 결과 n-amylmercaptide, n-hexylmercaptide, n-octylmercaptide, n-decylmercaptide ino에 대해 각각 2.82${\times}10^8$, 100${\times}10^8$, 2.23${\times}10^8$과 1.77${\times}10^8$ $M^{-2} .sec^{-1}$를 얻었고, n-amyl, n-hexyl, n-Octyl, n-decylmercaptan분자에 대해서는 각각 2.82${\times}10^{-2}$, 1.95${\times}10^{-2}$, 7.08${\times}10^{-2}$과 5.63${\times}10^{-2}$$M^{-1} . sec^{-1}$를 얻었으며, 염기성뿐만 아니라 산성용매 속에서도 그의 반응메카니즘을 잘 설명할 수 있는 반응속도 식도 구하였다.

• 공업화학
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• 제7권1호
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• pp.171-176
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• 1996

환경 친화성인 비이온 계면활성제 글루카마이드(N-알킬-N-아실 글루카민)는 크게 두 단계 반응으로 구분되는데, 첫 단계는 알킬 아민과 글루코스를 메탄올 용매하에 아민화 반응시킨 후, Ni 촉매하에 고압으로 환원시킨 결과 4종의 알킬 글루카민을 86~93%의 수율로 얻었다. 2단계 반응에서는 4종의 알킬 글루카민과 4종의 지방산 메틸 에스테르를 알칼리 촉매하에 메탄올을 환류시키면서 합성한 결과 16종중 12종의 글루카마이드는 84~95%수준의 높은 수율을 보였으나, 알킬기가 벤질일 경우에는 50~70%의 낮은 수율을 나타내었다. 알킬 글루카민 4종과 글루카마이드 16종에 대한 분자구조 확인은 IR, MS, NMR로 확인하였다.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.304-309
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• 2023

In the last decade, nuclear medicine appears to be a good choice of medicine. ⁵⁸Co, ⁹⁹Mo, ⁹⁹Tc, ⁹⁹Re, ¹³³Xe and ¹⁸⁶Re are very important radionuclides for nuclear medicine. In this study, the excitation functions of ⁵⁸Ni (n, p) ⁵⁸Co, ⁹⁹Tc (n, p) ⁹⁹Mo, ⁹⁹Ru (n, p) ⁹⁹Tc, ¹³¹Xe (n, p) ¹³¹I, ¹³³Cs (n, p) ¹³³Xe and ¹⁸⁶Os (n, p) ¹⁸⁶Re nuclear reactions were calculated at neutron energies between 1 and 20 MeV using TALYS 1.95 and EMPIRE 3.2 nuclear codes. Furthermore, the cross sections were calculated with the empirical formula derived in our past study at 14-15 MeV. The obtained results were compared with the measured values in EXFOR library, and with the evaluated data of (JENDL-4.0/HE, JEFF-3.3, TENDL-2019, ENDF/B-VIII.0, IRDFF-II, JENDL/ImPACT-18). The results are in good agreement with those of the evaluated data libraries and experimental results and indicates that these radioisotopes can be produced by smaller cyclotrons.

• 생명과학회지
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• 제9권3호
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• pp.289-292
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• 1999

1998년 부산지역에서 호흡기 환자의 인후 가검물로부터 분리된 influenza 바이러스 다음과 같은 양사을 볼 수 있었다. 1.분리된 바이러스는 influenza A/Sydney/05/97-like(H3N2)형과 influenza A/Beijing/262/95-like(H1N1)형으로 동정되었다.2.바이러스분리는 4월에서 9월까지를 제외한 모든 달에서 이루어 졌으며 특히 12월에는 집중적인 양상을 보였다.3.연령별로 본 바이러스의 분리는 1세에서 68세까지 전 연령층에서 나타났으며 10세 이하가 가장 높은 분리율을 나타내었다.4.바이러스 분리 비율은 남녀가 1:1.2의 비율로 나타났다.5.분리 바이러스는 MDCK 세포에서 세포병변이 관찰 되었다.6.influenza 바이러스를 Negative staining으로 염색하여 전자현미경으로 관찰한 결과 원형의 바이러스로 in-fluenza A/Sydney/05/97-like(H3N2)는 130 nm,influenza A/Beijing/262/95-like(H1N1) 형은 145nm의 크기로 나타났다.

• 한국가금학회지
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• 제17권3호
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• pp.167-177
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• 1990

제한급사가 산란능력에 미치는 영향을 조사하기 위하여 36주령 된 백색레그혼계통 산란계 3,087수가 수용된 계군으로부터 208수를 무작위로 추출하여 52수씩 4군으로 나누었다. 다음 1주간은 수당 100g의 사료를 급여하여 예비사육 한 뒤에 각각 수당 100, 95, 90 및 85g의 사료를 급여하여 3주간 실험 사육하여 산란능력을 113g을 급여한 원내의 계군의 성적과 비교하였다. 3주간의 열한급여 실험기간 중에 사료급여량이 감소함에 따라 일당증체중, 산란율, 난중 및 산란일양이 직선적으로 낮아졌다. 산란율 난중 및 산란일양은 일당 사료섭취량과 각각 y＝0.3753x＋38.75 (r＝0.503, n＝15), y＝48.2＋0.08868x(r＝0.835, n＝15) 및 y＝15.69＋0.2786x (r＝0.597, n＝15)로 표현되는 회귀식이 성립하였다. 한편 사료효율은 95g까지, 에너지 이용율도 95g까지 그리고 단백질이용율은 90g까지 사료제한도가 높을수록 높아졌다. 한편 사료섭취량의 제한이 난각두께에 미치는 영향이 관찰되지 않았으나, 사료급여량이 낮을수록 계란중 만백질함유비율이 높고 지질과 콜레스데롤 함량은 낮아지는 경향이 존재하였다. 따라서 본성적은 사료중여량을 16%(95 g)까지 제한할 수 있으며, 이때의 일당 체중감소량 3.5 g이 제한정도와 기간을 정하는 기준으로서 제시되었다. 한편 채란양계에서 113 g(100%)에서 95 g (84.1%)까지 사료급여량을 단계적으로 제한했을때, 사료가격이 당 200원이고 난가가 kg당 600원으로 하면 (난사가격 비＝3.0) 수당조수익(난가-사료가)은 사료 급여 량을 제한할수록 높았다.

• Korean Journal of Radiology
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• 제22권3호
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• 한국정밀공학회지
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• 제15권7호
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• pp.69-77
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• 1998

Development on the mechanical properties of steel sheet for the automobile body panel is very important in the BAF(Batch annealing furnace) annealing process. Because of the heat treatment method in the BAF, mechanical properties were decided on the heat treatment method of the coil. So, we tested on the development of mechanical properties according to heat treatment method at the annealing furnace using the In atmospheric gas($H_2$ : 75%, $N_2$ : 25%) and the HNx atmospheric gas($H_2$ : 5%, $N_2$ : 95%) We confirmed the following characteristics, mechanical properties were changed under the influence of the annealing cycle and the atmospheric gas. And, we have some result according to heat treatment method. Elongation of the mechanical properties in the HNx BAF is higher than the Ax BAF. But tensile strength and hardness is higher than the HNx BAF.

• Korean Journal of Radiology
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• 제24권2호
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• pp.133-144
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• 2023

Objective: Cyclin-dependent kinase inhibitor (CDKN)2A/B homozygous deletion is a key molecular marker of isocitrate dehydrogenase (IDH)-mutant astrocytomas in the 2021 World Health Organization. We aimed to investigate whether qualitative and quantitative MRI parameters can predict CDKN2A/B homozygous deletion status in IDH-mutant astrocytomas. Materials and Methods: Preoperative MRI data of 88 patients (mean age ± standard deviation, 42.0 ± 11.9 years; 40 females and 48 males) with IDH-mutant astrocytomas (76 without and 12 with CDKN2A/B homozygous deletion) from two institutions were included. A qualitative imaging assessment was performed. Mean apparent diffusion coefficient (ADC), 5th percentile of ADC, mean normalized cerebral blood volume (nCBV), and 95th percentile of nCBV were assessed via automatic tumor segmentation. Logistic regression was performed to determine the factors associated with CDKN2A/B homozygous deletion in all 88 patients and a subgroup of 47 patients with histological grades 3 and 4. The discrimination performance of the logistic regression models was evaluated using the area under the receiver operating characteristic curve (AUC). Results: In multivariable analysis of all patients, infiltrative pattern (odds ratio [OR] = 4.25, p = 0.034), maximal diameter (OR = 1.07, p = 0.013), and 95th percentile of nCBV (OR = 1.34, p = 0.049) were independent predictors of CDKN2A/B homozygous deletion. The AUC, accuracy, sensitivity, and specificity of the corresponding model were 0.83 (95% confidence interval [CI], 0.72-0.91), 90.4%, 83.3%, and 75.0%, respectively. On multivariable analysis of the subgroup with histological grades 3 and 4, infiltrative pattern (OR = 10.39, p = 0.012) and 95th percentile of nCBV (OR = 1.24, p = 0.047) were independent predictors of CDKN2A/B homozygous deletion, with an AUC accuracy, sensitivity, and specificity of the corresponding model of 0.76 (95% CI, 0.60-0.88), 87.8%, 80.0%, and 58.1%, respectively. Conclusion: The presence of an infiltrative pattern, larger maximal diameter, and higher 95th percentile of the nCBV may be useful MRI biomarkers for CDKN2A/B homozygous deletion in IDH-mutant astrocytomas.

• 한국자기학회지
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• 제10권1호
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• pp.16-21
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• 2000

Spin-Peierls(SP) 전이 현상을 나타내는 $Cu_{0.95}Ge_{0.95}Fe_{0.1}O_3$를 제조하여 자기적 특성과 결정학적 특성을 알기 위하여 x선 회절, 자기감수율과 Mossbauer 스펙트럼을 측정 분석하였다. 결정구조는 직방정계(orthorhombic)였고 격자 상수는 a = 4.795 $\AA$, b = 8.472 $\AA$, c = 2.932 $\AA$이며, SP 전이 온도($T_{sp}$)는 13 K임을 알아냈다. 상온에서 Mossbauer 스펙트럼은 $Fe^{3+}$ 이온에 의한 두 개의 Zeeman선과 한 개의 이중선이 중첩되어 나타났다. Ge 이온만을 Fe 이온으로 치환시켜 만든 시료의 Mossbauer스펙트럼은 Zeeman 선을 나타내고, Cu 이온만을 Fe 이온으로 치환시켜 만든 시료의 Mossbuer 스펙트럼은 이중선을 나타내는 것으로 보아 각각의 선이 Ge와 Cu 자리로 치환되어 들어간 Fe 이온에 의한 것으로 생각된다. 또한 $T_{sp}$ 이하에서 Mossbauer 변수들의 불연속을 이중체가 형성되면서 나타나는 이온들의 위치 이동에 관련시켜 해석하였다. 본 시료외 N el온도는 715 K이고, Debye온도는 팔면체 자리가 540 K, 사면체 자리가 380 K임을 알아냈다.

• 한국동물위생학회지
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• 제32권1호
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• pp.11-18
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• 2009

Porcine epidemic diarrhea virus (PEDV), an enveloped single stranded RNA virus in the family Coronaviridae, causes acute viral enteric disease in piglets. Recently outbreaks of porcine epidemic diarrhea (PED) have been rare in Europe but frequent in Asia. In Korea, the increase of PED prevalence is showing specially in postweaning pigs. The purpose of this study was to investigate nucleotide sequence of nucleocapsid protein gene of PEDV field isolates from postweaning pigs in Korea and get more information about the viruses. A total of 15 postweaing pigs clinically suspected of PEDV infection by severe watery diarrhea and dehydration were used in this study. Viral RNA was extracted from small intestines and stools of the pigs. The N gene was amplified by nested RT-PCR, purificated, sequenced, analyzed and then compared with published sequences of other PEDV strains. Three PEDVs were isolated from the suspected postweaning pigs. The N gene of three PEDV field isolates consisted of 483 nucleotides. These PEDV field isolates showed nucleotide sequence homology range from 99.6% to 95% with Chinese strains, from 99.8% to 95.2% with Korean strains, from 97.3% to 95.7% with Japanese strains and from 96.5% to 95.7% with Belgium and British strains. The encoded pritein shared range from 98.8% to 95.6% with Chinese strains, from 99.4% to 95% with Korean strains, from 97.5% to 96.3% with Japanese strains, from 95.6% to 95% with Belgium and British strains. By phylogenetic tree analysis based on nucleotide sequence, three PEDV field isolates were clustered into two groups which were Chinese isolate groups and other Korean isolate groups. These results indicated that some of PEDV field isolates prevailing in Korean postweaning pigs may be associated with those of Chinese strains and other Korean strains.