• Korean Journal of Materials Research
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• v.10 no.3
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• pp.218-222
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• 2000

W-Ti film properties for X-ray absorber applications have been investigated with Ti composition have been investigated with Ti composition variation. W-Ti films were deposited by DC magnetron sputtering system. As the working pressure increases, film density decreases and film stress changes from compressive to tensile. The transition pressure (where the film stress in zero) and the stress gradient decrease by adding Ti into W-Ti(6.5 at.%) film shows the smallest stress gradient and transition pressure. It also shows high density ($17.7g/\textrm{cm}^3$) similar to that of pure-W ($17.8g/\textrm{cm}^3$) at the transition pressure. All the films show columnar structure, and its size decreases with increasing Ti composition. Surface roughness and thermal stability are improved by Ti-addition, resulting in a better property for X-ray absorber applications.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.3
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• pp.293-301
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• 2011

The ionospheric delay is the largest error source in GPS positioning after the SA effect has been turned off in May, 2000. In this study, we used 44 permanent GPS stations being operated by National Geographic Information Institute (NGII) to estimate Total Electron Content (TEC) based on pseudorange measurements phase-leveled by a linear combination with carrier phases. The Differential Code Bias (DCB) of GPS satellites and receivers was estimated and applied for an accurate estimation of the TEC. To validate our estimates of DCB, changes of TEC values after DCB application were investigated. As a result, the RMS error went down by about an order of magnitude; from 35~45 to 3~4 TECU. After the DCB correction, ionospheric TEC maps were produced at a spatial resolution of $1^{\circ}{\times}1^{\circ}$. To analyze the effect of the number of sites used for map generation on the accuracy of TEC values, we tried 10, 20, 30, and 44 stations and the RMS error was computed with the Global Ionosphere Map as the truth. While the RMS error was 5.3 TECU when 10 sites are used, the error reduced to 3.9 TECU for the case of 44 stations.

• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.313-318
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• 2003

Environmental stresses, such as heat shock, alcohol and physiological salt have been shown to induce a group of protein called heat shock protein (HSPs) in various tissues. In this investigation, we studied that arsenic stress would alter contraction of isolated rat aorta and expression of heat shock protein 70 and investigated the relation between expression of HSP 70 and vascular contractility of isolated rat aorta. Rat aorta strips, mounted in organ baths were exposed to 0, 0.5, 1,2 and 4 mM arsonic for 60 min. and 1,3 and 8 hours later tested for contractile response and expression of heat shock protein 70. Contractility of rat aorta were determined by isometric transducer connected to computerized physiograph and expression of HSP 70 was characterized by western blotting, respectively. Potassium chloride (55 mM) significantly augmented vascular contractility of yat aorta by 39％ compared with the control at 8 hours but not one or three hours after treatment of 4 mM arsenic. Arsonic stress (4 mM) also increased the expression of HSP 70 in rat aorta at 8 hours but one or three hours compared with the control and HSP expressed in vascular smooth muscle cells and some expressed in endothelium cells. These results suggest that arsenic stress not only did alter the magnitude of the contractile response to high potassium chloride but also increased the expression of HSP 70 in the rat aorta.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.507-515
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• 2015

This paper suggests 6 cases of TFA parameters algorithm(Mean, VA, RS, SKEW, UN, EN) to search for the detection of recognition rates regarding breast disease using CAD on ultrasound images. Of the patients who visited a university hospital in Busan city from August 2013 to January 2014, 90 cases of breast ultrasound images based on the findings in breast US and pathology were selected. $50{\times}50$ pixel size ROI was selected from the breast US images. After pre-processing histogram equalization of the acquired test images(negative, benign, malignancy), we calculated results of TFA algorithm using MATLAB. As a result, in the TFA parameters suggested, the disease recognition rates for negative and malignancy was as high as 100%, and negative and benign was approximately 83~96% for the Mean, SKEW, UN, and EN. Therefore, there is the possibility of auto diagnosis as a pre-processing step for a screening test on breast disease. A additional study of the suggested algorithm and the responsibility and reproducibility for various clinical cases will determine the practical CAD and it might be possible to apply this technique to range of ultrasound images.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.655-659
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• 2008

Intestinal pseudo-obstruction (IPO) is a rare and poorly understood manifestation of systemic lupus erythematosus (SLE), especially in children. The characteristic clinical feature of IPO is obstruction without an identifiable obstructive lesion. The authors a 13-year-old girl whose first symptom of SLE was IPO. The patient presented with a 3-day history of nausea, bilious vomiting, abdominal distention, and no bowel movement. Simple abdominal radiographs revealed mild dilatation with partial air-fluid levels in the small intestine. Abdominal CT and methylcellulose small bowel studies showed massive ascites, engorgement of the small mesenteric vessels, pleural effusion, and diffuse bowel wall thickening of the gastric antrum, duodenum. and jejunum. The delayed passage of contrast for 15 days after the methylcellulose small bowel studies was suggestive of decreased bowel motility. Laboratory findings were positive for ANA, anti-double-stranded DNA, anti-Smith and lymphopenia. After 10-day treatment with high-dose corticosteroids, the symptoms improved. IPO associated with SLE should be considered in the differential diagnosis for patients presenting with symptoms of intestinal obstruction. Early recognition of IPO in SLE and appropriate therapy are important for prevention of complications and unnecessary surgery. This case raises awareness among pediatricians that although rare, IPO can be the presenting symptom of SLE in children.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.373-380
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• 1996

Recently we reported that GS 386, 1-(4'-methoxybenzyl)-6,7-dimethoxy-3,4-dihydroisoquinoline, inhibited amplitude of the $Ca^{2+}$ current by reducing the probability of $Ca^{2+}$ channel opening without changing channel kinetics in isolated rabbit atrial myocyte. In the present study, further investigation of the mechanism of action of GS 386 was performed using isolated rat trachealis. GS 386 concentration-dependently relaxed rat trachealis contracted by carbachol $(0.3{\mu}M)$ and high $K^+$(65.4 mM) with $IC_{50}$ 5.24 and 5.67 ${\mu}M$, respectively. Verapamil inhibited more effectively the high $K^+-contracted$ tissues than those with carbachol in the rat trachealis muscle. In $Ca^{2+}-free$ media, $Ca^{2+}-induced$ contraction was inhibited by GS 386. Furthermore, high concentration of GS 386 $(100{\mu}M)$ but not verapamil, attenuated a phasic contraction induced not only by carbachol but also caffeine, indicating that GS386 can enter into the cytoplasm where it may exert secondary actions on internal sites of the muscle, such as sarcoplasmic reticulum. Moreover, GS 386 showed verapamil-resistant component of relaxation and increased cAMP levels in rat trachal smooth muscle. These results suggest that the mechanism of action of GS 386 attributes to not only $Ca^{2+}$ antagonistic action but also weak phosphodiesterase inhibitory action.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.381-388
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• 1996

The hemodynamic changes in septic patients produced by inhalational anesthetics are sufficient to threaten the anesthesiologists. The effect of hydroxocobalamin, a vitamin $B_{12a}$, on contractile responses to phenylephrine during administration of inhalational anesthetics were evaluated in aortic ring preparations obtained from LPS-treated rats. The sepsis was developed by intraperitoneal injection of LPS (1.5 mg/kg for l8h) and confirmed by iNOS expression using RT-PCR. Statistical significances (P<0.05) were analyzed by Student's t-test or paired t-test according to data characteristics. The blood pressure, but not heart rate, was decreased in LPS-treated rats as compared to control rats. The contractile response to phenylephrine were dose-dependently increased from the doses of $10^{-8}\;M$ to that of $10^{-5}$ and were attenuated in LPS-treated rings. Both halothane and enflurane, at the doses of 1 MAC, decreased the contractile responses to phenylephrine while isoflurane did not significantly affect the contractile responses. Hydroxocobalamin ($10^{-5}$ M) significantly potentiated the contractile responses in the LPS-treated aortic ring preparations during administration of each inhalational anesthetic or not. From these results, it is suggested that hydroxocobalamin may improve the hemodynamics of septic patients during inhalational anesthesia. Abbreviations: LPS, lipopolysaccharide; RT-PCR, reverse transcription-polymerase chain reaction; MAC, minimum alveolar concentration; iNOS, inducible nitric oxide synthase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.101-109
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• 1994

Pharmacological characterization of GS 283, a tetrahydroisoquinoline derivative has been elucidated using rat thoracic aorta, guinea pig tenea coli and rabbit mesentery artery in vitro. GS 283 showed calcium antagonistic action in vascular smooth muscle, since high $K^+-induced$ contraction was concentration dependently inhibited. GS 283 also inhibited the contraction induced by ${\alpha}_1$ receptor activation. Vasodilating action of GS 283 was not modified by the propranolol, indicating that GS 283 has no ${\beta}$ receptor stimulatory action. Simultaneous measurement of intracellular calcium change and muscle tension indicated that the inhibitory effect of GS 283 was accompanied by the increase in tissue fluorescence. This increment was not due to fura 2 fluorescence but to endogenous pyridine nucleotide, suggesting that GS 283 has an effect to inhibit mitochondrial function. GS 283 had an inhibitory action on cyclic AMP and GMP-dependent phosphodiesterases from rat brain with Ki values of 2.5 and 6.7 mM. From these findings we concluded that GS 283 has multiple action such as the inhibition of cyclic nucleotide-dependent phosphodiesterases, blocking of calcium channel as well as inhibition of mitochondrial function which are responsible for vasodilatation.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.159-172
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• 1996

대기오염물질이면서 동시에 생체내 화학반응의 산물이기도 한 nitric oxide(NO)는 그 생체내 분포가 광범위하고 생리적 역할이 다양하여, 최근의 생명과학 분야에서 가장 크게 주목받는 몇가지 연구대상 중 하나이다. 세포에서의 NO 산생은 nitric oxide synthase (NOS)에 의해 촉매되는데, 이들은 brain form (bNOS, neuronal; nNOS, NOS I), inducible form (iNOS), 및 endothelial form(eNOS)로 구분되는데, 이중 bNOS(nNOS)와 eNOS는 inducible form에 대비되는 constitutive form(cNOS)에 해당하므로 각각 ncNOS 와 ecNOS로도 불리운다. NOS는 아미노산인 L-arginine을 산소와 결합시켜 L-citrulline으로 변환시키면서 NO를 유리하고, 이 NO는 세포내의 guanylate cyclase를 활성화하여 cyclic GMP를 생산하거나, superoxide(O2-) 및 수소이온과 차례로 결합하여 반응성이 매우 높은 수산화기(-OH)를 발생시켜 세포독작용을 유발하기도 한다. 정상상태에서 뇌혈관내피세포의 ecNOS로 부터 유리된 NO는 혈관을 확장시켜 신경세포에 대한 산소공급을 원활히 유지해 주지만, 순환장애를 일으켰을 때는 뇌조직내의 iNOS로부터 대량의 NO가 유출되어 신경세포의 손상을 가져온다. 호흡기에서는 NO가 기도평활근을 이완시키고 폐혈류를 개선하므로, 미숙아나 성인의 호흡장애시에 소량의 NO를 흡입시키면 oxygenation을 호전시킬 수 있다. 그러나 대기오염이나 흡연 등으로 대량의 NO를 흡입할 경우 치명적인 폐부종이나 methemoglobin혈종을 일으킬 수 있다. 순환계에서는 cNOS가 혈관을 확장시켜 조직의 혈류를 유지하는데 일익을 담당한다. 세균내 독소(lipopolysaccharide; LPS)나 각종 명역조절물질들이 혈관내피세포와 혈관평활근세포로 부터 과다한 NO를 유리시키면 혈압이 급격히 떨어져 순환허탈상태에 빠지게 된다. 심장에서는 관상혈관 내피세포의 eNOS가 심근의 혈류를 유지해 주지만 허혈이나 세균내독소 또는 면역조절물질 등에 의하여 심근세포나 침윤된 대식세포의 iNOS로 부터 과량의 NO가 유리되면 심근세포의 손상이 초래된다. 신장에서는 내피세포의 cNOS에 의하여 사구체여과가 조절되고 있는데, 세균내독소나 면역 조절물질 등에 의하여 사구체관막세포(mesangial cell)등의 iNOS로 부터 과량의 NO가 유리되면 신조직과 사구체의 손상을 초래한다. 위와 같이 대부분의 장기에서 ecNOS는 조직의 혈류를 유지하는 역할을 하며, iNOS는 애초 세균 등 침입자에 대한 세포독작용이 그 존재 목적이라고 풀이할 수 있겠으나 일종의 부작용으로 자체조직의 손상을 초래하게 되는 것으로 본다. 따라서 NO와 관련된 각종 병변의 치료를 위해서는 NOS의 비선택성 억제제인 arginine 유도체 보다는 iNOS에 대한 선택적 억제제인 S-methylisothiourea(SMT), aminoethylisothiourea(AETU), aminoguanidine (AMG), agmatine, L-canavanine, transforming growth factor b1(TGF-b1) 등의 사용을 검토해 보는 것이 타당할 것으로 사료된다.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.303-310
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• 2013

Thyroid nodular disease is the most frequently appeared in thyroid disease. Thyroid ultrasonography offers location of nodules, size, the number, information of internal echo characteristic. Thus, it makes possible to sort high-risk nodule containing high possibility about thyroid cancer and to induct precisely when take a Fine Needle Biopsy Aspiration. On thyroid nodule, the case which is diagnosed as malignant is less than 5% but screening test is very important on ultrasound and also must be reduced unnecessary procedure. Therefore, in this study an approach for describing a region is to quantity its texture content. We applied TFA algorithm on case which has been pathologically diagnosed as papillary thyroid cancer. we obtained experiment image which set the ROI on ultrasound and cut the $50{\times}50$ pixel size, histogram equalization. Consequently, Disease recognition detection efficiency of GLavg, SKEW, UN, ENT parameter were high as 91~100%. It is suggestion about possibility on CAD which distinguishes thyroid nodule. In addition, it will be helpful to differential diagnosis of thyroid nodule. If the study on additional parameter algorithm is continuously progressed from now on, it is able to arrange practical base on CAD and it is possible to apply various disease in the thyroid US.